JP2012034205A - Manufacturing method and manufacturing apparatus of camera module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing apparatus of a camera module, capable of reducing the number of adjustments by mitigating the influence of an axial shift in a positional adjustment of an imaging surface with respect to an approximate image surface.SOLUTION: A camera module 10 has a structure where a lens unit 1 having a photographic lens 1a is integrated with an imaging unit 2 having a image pickup device 2a. A direct acting actuator 9 includes three pieces of movable parts 9a, each of which is independently movable in a direction of an optical axis AX of the photographic lens 1a. The imaging unit 2, in which an imaging surface 2s of the image pickup device 2a is disposed in vertical to the optical axis AX, is moved in parallel to the direction of the optical axis AX using the three pieces of movable parts 9a of the direct acting actuator 9, thereby, an appropriate plane of an image surface formed with the photographic lens 1a is measured as an appropriate surface. The imaging unit 2 is moved by the three pieces of movable parts 9a of the direct actuator 9, so that arbitrary three points on an imaging plane, which includes the imaging surface 2s, is positioned on the approximate image surface by independently moving in the direction of the optical axis AX.

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a camera module, and more particularly to a manufacturing method and a manufacturing apparatus for a camera module that adjust the position of an imaging surface with respect to an approximate image plane in assembling the camera module.

  A camera module mounted on a mobile phone or the like has a structure in which a lens unit having a photographing lens and an imaging unit having an imaging element are integrated. In assembling the camera module, the optical performance of the camera module is ensured by three-dimensionally adjusting the image pickup surface of the image pickup element with respect to the image plane formed by the photographing lens.

  For example, in the method for manufacturing a camera module proposed in Patent Document 1, the approximate image plane of the photographing lens is calculated and the imaging unit is fixed by measuring the focus positions at the four on-axis and off-axis corners. By moving the stage, the position of the imaging surface relative to the approximate image surface is adjusted. The positional deviation of the imaging surface with respect to the focus position on the axis is adjusted by moving the uniaxial linear movement stage to change the distance between the imaging lens and the imaging element (lens back adjustment), and imaging with respect to the inclination of the approximate image plane The deviation of the tilt of the surface is adjusted by decomposing the measured image plane information into XY biaxial components and individually moving the biaxial rotary stage (gonio stage) (tilt adjustment).

JP 2010-21985

  In general multi-axis position adjustment, when one axis is adjusted, the measurement value of another axis often shifts. The cause is an error in the axis of the adjustment actuator in the camera module manufacturing apparatus, or an error in the axis between the product to be adjusted and the manufacturing apparatus. When such a shift occurs, the number of adjustments increases, and the machine time (adjustment time) of the manufacturing apparatus may increase. Since the camera module itself is as small as 10 mm square or less and the required adjustment accuracy is high, it is difficult to suppress such errors.

  In the case of the manufacturing method proposed in Patent Document 1, an approximate plane of the image plane is calculated from focus position data measured at a total of five locations on the center (on the axis) on the imaging surface and four corners off the axis. . The difference between the imaging plane (the plane including the imaging plane) with respect to the approximate plane (approximate image plane) is decomposed into components of the tilt X direction, the tilt Y direction, and the Z direction, and the X direction tilt stage Adjustment is performed by moving the Y-direction tilt stage and the Z-direction linear movement stage. For this reason, if the calculation axis when the measurement result is decomposed into each component does not coincide with the actual movement axis of the actuator, a deviation that affects the other axes occurs in each axis. In the Z direction, since the image plane is measured by the Z direction linear motion stage, the error in the Z direction itself may be canceled out, but the error in the rotating stage in the XY direction is not canceled out. The occurrence cannot be suppressed. In other words, if there is a deviation between the measurement axis and the adjustment axis, or if there is a deviation between the adjustment axes, a phenomenon may occur in which adjusting one axis will cause the other axis to be displaced, resulting in a large number of adjustments. is there.

  The present invention has been made in view of such a situation, and an object thereof is to reduce the number of adjustments by reducing the influence of axial misalignment in the position adjustment of the imaging surface with respect to the approximate image surface. It is an object to provide a manufacturing method and a manufacturing apparatus for a camera module.

  In order to achieve the above object, a manufacturing method of a camera module according to a first aspect of the present invention is a manufacturing method of a camera module having a structure in which a lens unit having a photographing lens and an imaging unit having an imaging element are integrated. In addition, the lens unit and the imaging unit are arranged so that the imaging surface of the imaging element is positioned perpendicular to the optical axis of the imaging lens, and the imaging unit is translated in the optical axis direction. Thus, a measurement process for measuring an approximate plane of an image plane formed by the photographing lens as an approximate image plane, and a plane including the imaging plane as an imaging plane, any three points on the imaging plane are independent from each other. An adjustment step of moving the imaging unit so as to be positioned on the approximate image plane by movement in the optical axis direction.

  The manufacturing method of the camera module of the second invention is characterized in that, in the first invention, the action point when the imaging unit moves in the adjustment step coincides with any three points on the imaging plane. To do.

  According to a third aspect of the present invention, there is provided a method of manufacturing a camera module according to the first aspect, wherein an action point when the imaging unit moves in the adjustment step is a position where the arbitrary three points are translated in the optical axis direction. It is characterized by doing.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a camera module according to the second or third aspect, wherein the imaging surface is located within a triangle having the three arbitrary points as vertices.

  According to a fifth aspect of the present invention, there is provided a camera module manufacturing method according to the first aspect, wherein any three of the imaging planes in the orthogonal coordinate system (X, Y, Z) in which the optical axis of the photographing lens is the Z axis. When the points are A (X1, Y1, 0), B (X2, Y2, 0), and C (X3, Y3, 0), three points corresponding to the points A, B, and C in the approximate image plane: A Z coordinates of '(X1, Y1, Z1), B' (X2, Y2, Z2), C '(X3, Y3, Z3): points A, B, C are The imaging unit is moved in the adjustment step so as to be positioned on the approximate image plane by independent movement in the Z direction.

  According to a sixth aspect of the present invention, in the fifth aspect of the invention, the point of action when the imaging unit moves in the adjustment step matches any three points A, B, and C on the imaging plane. It is characterized by doing.

  According to a seventh aspect of the present invention, there is provided a camera module manufacturing method according to the sixth aspect, wherein the imaging surface is located within a triangle having the three points A, B, and C as vertices.

  A camera module manufacturing apparatus according to an eighth aspect of the present invention is a camera module manufacturing apparatus having a structure in which a lens unit having a photographic lens and an imaging unit having an imaging element are integrated, and the light of the photographic lens. A linear motion actuator having three movable parts that are movable independently of each other in the axial direction, the imaging unit arranged so that an imaging surface of the imaging device is positioned perpendicular to the optical axis, By measuring the approximate plane of the image plane formed by the photographing lens as an approximate image plane by translating in the optical axis direction with the three movable parts of the actuator, the plane including the imaging plane is used as the imaging plane. The three units of the linear motion actuator move the imaging unit so that any three points on the imaging plane are positioned on the approximate image plane by movement in the optical axis direction independent of each other. And wherein the moving the door.

  The camera module manufacturing apparatus according to a ninth aspect of the present invention is the camera module manufacturing apparatus according to the eighth aspect, wherein action points when the imaging unit is moved by the three movable parts coincide with any three points on the imaging plane. It is characterized by.

  The camera module manufacturing apparatus according to a tenth aspect of the present invention is the camera module manufacturing apparatus according to the eighth aspect, wherein the three moving parts move the imaging unit to a position where the arbitrary three points are translated in the optical axis direction. A point is located.

  An apparatus for manufacturing a camera module according to an eleventh aspect is characterized in that, in the ninth or tenth aspect, the imaging surface is located in a triangle having the three arbitrary points as vertices.

  A camera module manufacturing apparatus according to a twelfth aspect of the present invention is the apparatus for manufacturing a camera module according to the eighth aspect of the present invention, in the rectangular coordinate system (X, Y, Z) in which the optical axis of the photographing lens is the Z axis. When the points are A (X1, Y1, 0), B (X2, Y2, 0), and C (X3, Y3, 0), three points corresponding to the points A, B, and C in the approximate image plane: A Z coordinates of '(X1, Y1, Z1), B' (X2, Y2, Z2), C '(X3, Y3, Z3): points A, B, C are The imaging unit is moved by the three movable parts so as to be positioned on the approximate image plane by independent movement in the Z direction.

  The camera module manufacturing apparatus according to a thirteenth aspect of the present invention is the camera module manufacturing apparatus according to the twelfth aspect of the present invention, wherein the action points when the imaging unit moves by the three movable parts are arbitrary three points A, B, It is coincident with C.

  According to a fourteenth aspect of the present invention, there is provided the camera module manufacturing apparatus according to the thirteenth aspect, wherein the imaging surface is located within a triangle having the three points A, B, and C as vertices.

  A camera module manufacturing apparatus according to a fifteenth aspect of the present invention is the camera module manufacturing apparatus according to any one of the eighth to fourteenth aspects, further comprising an adjustment table to which the imaging unit is fixed, the adjustment table including three linear motion actuators. The imaging unit is moved by moving the imaging unit in contact with the movable unit, and the contact point between the adjustment table and the three movable units is an action when the imaging unit moves with the three movable units. It is a point.

  According to a sixteenth aspect of the present invention, there is provided the camera module manufacturing apparatus according to the fifteenth aspect, wherein the contact between the adjustment table and the three movable parts is a point contact or a circular line contact.

  The camera module manufacturing apparatus according to a seventeenth aspect of the present invention is the camera module manufacturing apparatus according to the fifteenth or sixteenth aspect of the present invention, wherein the three movable portions have spherical tip surfaces and are in contact with the tip surfaces. The adjustment table has a receiving part, the first receiving part has a circular hole, the second receiving part has a flat surface, and the third receiving part has a long hole. .

  The camera module manufacturing apparatus according to an eighteenth aspect of the present invention is the camera module manufacturing apparatus according to any one of the fifteenth to seventeenth aspects, further comprising a spring that biases the adjustment table toward the contact point of the movable portion. To do.

  According to a nineteenth aspect of the present invention, there is provided the camera module manufacturing apparatus according to the eighteenth aspect, wherein the spring is a tension spring.

  A camera module manufacturing apparatus according to a twentieth aspect of the present invention is the camera module manufacturing apparatus according to the eighteenth aspect, wherein the spring is a leaf spring.

  According to the method for manufacturing a camera module of the present invention, by measuring the approximate plane of the image plane formed by the photographing lens as the approximate image plane by moving the imaging unit in the optical axis direction, the plane including the imaging plane is measured. As the imaging plane, the imaging unit is moved so that any three points on the imaging plane are positioned on the approximate image plane by movement in the optical axis direction independent of each other. Because it is only linear motion, it is difficult for adjustment deviation of each axis to occur, and since both the measurement axis and adjustment axis are parallel to the optical axis, there is a possibility that even if there is an error in the optical axis direction, it can be canceled out. high. Therefore, in the position adjustment of the imaging surface with respect to the approximate image surface, it is possible to reduce the number of adjustments by reducing the influence of axial misalignment.

  According to the camera module manufacturing apparatus of the present invention, the approximate plane of the image plane formed by the photographing lens is approximated by approximating the image plane formed by the taking lens by translating the imaging unit in the optical axis direction by the three movable parts of the linear motion actuator. The three planes of the linear motion actuator are positioned so that any three points on the imaging plane are positioned on the approximate image plane by movement in the optical axis direction independent from each other. Since the imaging unit is moved by the movable part, the position adjustment of the three axes is performed only by the linear actuator. Therefore, adjustment of each axis is unlikely to occur, and both measurement and adjustment can be performed only by the linear actuator. Since it is performed, even if there is an error in the optical axis direction, there is a high possibility that it will be canceled. Therefore, in the position adjustment of the imaging surface with respect to the approximate image surface, it is possible to reduce the number of adjustments by reducing the influence of axial misalignment.

The block diagram which shows typically one Embodiment of the manufacturing apparatus of a camera module. The flowchart which shows the manufacturing method of the camera module using the manufacturing apparatus of FIG. The conceptual diagram which shows typically the position adjustment of the imaging surface with respect to an approximate image surface. The top view which shows typically the arrangement | positioning of the action point of the movable part of a linear motion actuator, and the imaging surface of an imaging unit. The front view which shows the specific example of the contact structure of the type with which the movable part of a linear motion actuator and the receiving part of an adjustment table make point contact. Sectional drawing which shows the specific example of the contact structure of the type which the movable part of a linear motion actuator and the receiving part of an adjustment table line-contact circularly. The figure which shows the specific example of the contact structure of a type which three movable parts contact in the state which mutually differs with respect to the receiving part of an adjustment table. Sectional drawing which shows the specific example of the contact structure of the type which urges | biases an adjustment table toward the contact point of the movable part of a linear motion actuator. The front view which shows the other specific example of the contact structure of the type which urges | biases an adjustment table toward the contact point of the movable part of a linear motion actuator.

  Hereinafter, a camera module manufacturing method, a manufacturing apparatus, and the like embodying the present invention will be described with reference to the drawings. In addition, the same code | symbol is mutually attached | subjected to the mutually same part of each specific example etc., and duplication description is abbreviate | omitted suitably.

  FIG. 1 shows a schematic configuration of a manufacturing apparatus 20 for the camera module 10. The camera module 10 has a structure in which the lens unit 1 and the imaging unit 2 are integrated. The lens unit 1 includes a photographic lens 1a, a focus actuator (not shown), and the like. The imaging unit 2 includes an imaging device (for example, a solid-state imaging device such as a charge coupled device (CCD) image sensor, a complementary metal-oxide semiconductor (CMOS) image sensor) 2a, a substrate (not shown), and a frame for holding them. It consists of parts (not shown).

  The manufacturing apparatus 20 includes a light source 3, a chart 4, a lens unit holding unit 5, an imaging unit holding unit 6, a probe unit 7, an adjustment table (tilt table) 8, a three-axis linear motion actuator 9, a personal computer (PC) 11, and the like. It has. The chart 4 is a subject for adjustment of the camera module 10, and when illuminated with light from the light source 3, an optical image of the illuminated chart 4 is formed by the photographing lens 1a. The lens unit 1 on which the photographing lens 1 a is mounted is held by the lens unit holding unit 5 at a fixed position in the manufacturing apparatus 20. The imaging unit holding unit 6 is fixed to the adjustment table 8, and the imaging unit 2 equipped with the imaging element 2 a is fixedly held by the imaging unit holding unit 6. A contact probe 7a of the probe unit 7 is in contact with the land surface of the substrate attached to the image sensor 2a during adjustment, and an image signal from the image sensor 2a is taken into the personal computer 11 via the probe unit 7. The personal computer 11 controls the entire manufacturing apparatus 20 such as image plane measurement and calculation of the amount of movement given to the linear motion actuator 9.

  The linear actuator 9 is provided with three axes, each of which includes a movable portion 9a, a fixed portion 9b, and the like (partially omitted in FIG. 1). The movable portions 9a of the three-axis linear actuator 9 are arranged in parallel to each other and are movable in the direction of the optical axis AX of the photographing lens 1a. Since each linear actuator 9 can adjust the movement of the movable portion 9a, the three movable portions 9a are movable independently of each other in the optical axis AX direction. The adjustment table 8 is provided with a receiving portion 8a, and the adjustment table 8 is placed on the tips of the three movable portions 9a by the receiving portion 8a. The tip of the movable portion 9a is an action point 9p and is in contact with the receiving surface 8s of the receiving portion 8a. Since one plane is determined by the three action points 9p, when the three movable parts 9a are moved up and down (in the optical axis AX direction), the position and inclination of the adjustment table 8 in the optical axis AX direction change. Since the image pickup unit holding unit 6 is fixed to the adjustment table 8, when the adjustment table 8 is moved by the linear actuator 9, the position and inclination of the image pickup unit 2 in the optical axis AX direction change.

  Next, a manufacturing method of the camera module 10 using the manufacturing apparatus 20 of FIG. 1 will be described. FIG. 2 shows a flowchart of the manufacturing method of the camera module 10, and FIG. 3 schematically shows the position adjustment of the imaging surface 2 s with respect to the approximate image surface L. First, the lens unit 1 and the imaging unit 2 are attached to the manufacturing apparatus 20 in the setting step (# 10). At this time, the lens unit 1 and the imaging unit 2 are arranged so that the imaging surface 2s of the imaging element 2a is positioned perpendicular to the optical axis AX of the imaging lens 1a.

  In the next measurement step (# 20), the image plane IM (FIG. 3) is measured. Here, the approximate plane of the image plane IM formed by the photographing lens 1a is measured as the approximate image plane L by translating the imaging unit 2 in the optical axis AX direction by the three movable portions 9a of the linear actuator 9. To do. That is, the same moving amount is given to the three movable portions 9a of the linear actuator 9 to move, and the image pickup unit 2 is moved together with the adjustment table 8, and the image of the chart 4 is taken from the image pickup device 2a to perform defocus measurement. Do.

  Calculate the MTF (Modulation Transfer Function) or CTF (Contrast Transfer Function) from the captured image (chart image) while performing the defocus operation, and focus position at the center (on the axis) and at the four corners (off-axis). Is obtained (FIG. 3). From the center and the four corner positions (X, Y) and their focus positions (Z), an approximate plane when these five points are expanded into spatial coordinates is obtained as an approximate image plane L. In general, since the plane in space is determined by one of the three points, the values of the five points are not all on one plane (that is, the focus positions at the four corners on the axis and off the axis are field curvature, etc.) It is not on one plane due to the influence of the aberration. Therefore, the approximate image plane L is obtained using a least square method or the like.

  In the next adjustment step, the personal computer 11 calculates the amount of movement of the linear actuator 9 (that is, the amount of movement of each of the three movable parts 9a) (# 30), and the movement of the linear actuator 9 (that is, 3). The movable part 9a of the book is moved) (# 40). At this time, assuming that the plane including the imaging plane 2s is the imaging plane M, any three points A, B, and C on the imaging plane M are positioned on the approximate image plane L by movement in the optical axis AX direction independent of each other. Then, the imaging unit 2 is moved by the three movable parts 9a of the linear actuator 9 (# 40). The movement amount calculation (# 30) is performed as follows.

  As shown in FIG. 3, the approximate image plane L obtained from the focal positions of the lens unit 1 on the axis and at the four off-axis corners is expressed by an expression of the plane L: aX + bY + cZ + d = 0. A plane including the imaging surface 2s of the imaging element 2a is expressed as an imaging plane M by an expression: Z = 0. That is, since the measurement (# 20) of the image plane IM is performed by moving the imaging unit 2 in the optical axis AX direction (Z direction) by the three movable portions 9a of the linear motion actuator 9, the image plane IM is measured. The formula is Z = 0.

  In the adjustment step (# 40), in the orthogonal coordinate system (X, Y, Z) having the optical axis AX of the photographing lens 1a as the Z axis, arbitrary three points on the imaging plane M are represented by A (X1, Y1, 0). , B (X2, Y2, 0), C (X3, Y3, 0), three points corresponding to the points A, B, C in the approximate image plane L: A ′ (X1, Y1, Z1), B Z coordinates of '(X2, Y2, Z2), C' (X3, Y3, Z3): Approximate image planes by moving the points A, B, and C in the Z direction independent of each other, with Z1, Z2, and Z3 as movement amounts The imaging unit 2 is moved by the three movable parts 9a so as to be positioned on L. In FIG. 3, the action points when the imaging unit 2 moves by the three movable parts 9 a of the linear actuator 9 are set to coincide with arbitrary three points A, B, and C on the imaging plane M. Therefore, the action point when the imaging unit 2 moves is located on the same plane as the imaging surface 2s of the imaging element 2a.

  X coordinates: X1, X2, X3; Y coordinates: Y1, Y2, Y3 are determined by the arrangement of the three movable parts 9a, and are constants specific to the manufacturing apparatus 20. From this, the values of Z1 to Z3 can be obtained by using the expression of approximate image plane L obtained from the image plane IM obtained by defocus measurement (# 20): aX + bY + cZ + d = 0. Therefore, as described above, the Z coordinates: Z1, Z2, and Z3 of the three points: A ′, B ′, and C ′ are the movement amounts of the linear actuator 9 (the movement amounts of the three movable portions 9a).

  When the adjustment step (# 40) is completed, the same image plane measurement as the image plane measurement (# 20) is performed again for confirmation (# 50). It is determined whether it is within the adjustment target, and the control (# 30 to # 60) is repeated until the imaging surface 2s is positioned on the approximate image surface L within the target range. When the position adjustment of the imaging surface 2s with respect to the approximate image plane L is completed, an adhesive is applied between the lens unit 1 and the imaging unit 2 (# 70), and the adhesive is cured (# 80). For example, an ultraviolet curable adhesive is applied (# 70), and the adhesive is cured by irradiating the adhesive with ultraviolet rays (# 80). When the adhesive is cured, the camera module 10 in a state in which the lens unit 1 and the imaging unit 2 are coupled is taken out from the manufacturing apparatus 20, and the manufacturing of the camera module 10 is completed.

  In the manufacturing method of this embodiment (FIG. 2, etc.), the approximate plane of the image plane IM formed by the photographing lens 1a is measured as the approximate image plane L by translating the imaging unit 2 in the direction of the optical axis AX. The imaging unit 2 is moved so that the plane including the imaging plane 2s is the imaging plane M, and any three points on the imaging plane M are positioned on the approximate image plane L by movement in the optical axis AX direction independent of each other. It is configured. As described above, since the position adjustment of the three axes is only the linear movement, the adjustment deviation of the individual axes hardly occurs, and since the measurement axis and the adjustment axis are both parallel to the optical axis AX, the optical axis AX direction Even if there is an error, there is a high possibility that it will be offset. Therefore, in the position adjustment of the imaging surface 2s with respect to the approximate image plane L, it is possible to reduce the number of adjustments by reducing the influence of the axis deviation.

  Further, in the manufacturing apparatus 20 (FIG. 1 and the like) according to this embodiment, the imaging unit 2 is formed by the photographing lens 1a by moving the imaging unit 2 in the direction of the optical axis AX by the three movable portions 9a of the linear motion actuator 9. The approximate plane of the image plane IM is measured as the approximate image plane L, and the plane including the imaging plane 2s is defined as the imaging plane M, and any three points on the imaging plane M are approximated by movement in the optical axis AX direction independent of each other. The imaging unit 2 is moved by the three movable portions 9a of the linear motion actuator 9 so as to be positioned on the image plane L. As described above, since the position adjustment of the three axes is performed only by the linear actuator 9, the adjustment deviation of each axis is not easily generated, and since both measurement and adjustment are performed only by the linear actuator 9, the optical axis AX direction Even if there is an error, there is a high possibility that it will be offset. Therefore, in the position adjustment of the imaging surface 2s with respect to the approximate image plane L, it is possible to reduce the number of adjustments by reducing the influence of the axis deviation.

  In this embodiment, the positional deviation between the image plane IM and the imaging plane 2s is a deviation between two planes, that is, the plane including the approximate plane L of the image plane IM and the imaging plane 2s. The focus is on the positional deviation between a certain imaging plane M. Since the three-dimensional deviation of the approximate image plane L with respect to the imaging plane M is expressed by the formula of the plane L: aX + bY + cZ + d = 0, the value of Z of the approximate image plane L obtained therefrom is used as the movement amount of the linear actuator. Thus, the imaging plane M can be directly aligned with the approximate image plane L. At this time, since the three-dimensional position of the imaging surface 2s can be adjusted by the amount of movement of the three-axis linear actuator 9 only in the Z direction (for example, there is no rotation by the two-axis rotary stage), the individual axes can be adjusted. Adjustment deviation is unlikely to occur. In addition, since the image plane measurement is also performed by the three-axis linear motion actuator 9, there is a high possibility that any error will be canceled out. Since the measurement actuator and the adjustment actuator are the same for all three axes, and there is no deviation between the measurement axis and the adjustment axis, the imaging surface can be tilted according to the measurement result. In the prior art, only a linear actuator is used for measurement, and a linear actuator and a rotary actuator are used for adjustment. Therefore, the influence of axial deviation is inevitable.

  In this embodiment, for example, in the adjustment process, the action point when the imaging unit 2 moves with the three movable parts 9a coincides with arbitrary three points A, B, and C on the imaging plane M. However, an action point when the imaging unit 2 moves by the three movable portions 9a may be located at a position where any three points A, B, and C are translated in the optical axis AX direction (for example, , When the thickness of the receiving portion 8a in FIG. 1 is changed). However, as shown in FIG. 1, if the action point 9p of the movable portion 9a of the linear actuator 9 is arranged on the same plane as the imaging plane 2s (that is, on the imaging plane M), the center of the imaging plane 2s is adjusted during tilt adjustment. And the center position of the optical axis AX of the taking lens 1a are less likely to occur.

  FIG. 4 schematically shows the arrangement of the action point 9 p of the movable portion 9 a of the linear actuator 9 and the imaging surface 2 s of the imaging unit 2. In this embodiment, as shown in FIG. 4, the imaging surface 2s is positioned within a triangle having arbitrary three points A, B, and C as vertices. Arranging the imaging element 2a so that the imaging surface 2s is located within a triangle having the three points A, B, and C as vertices is advantageous in terms of stability of adjustment accuracy. If the image pickup device 2a is arranged so that the image pickup surface 2s is located outside the triangle, the rigidity of the manufacturing apparatus 20 is deteriorated and easily affected by an error, so that the adjustment accuracy may be lowered.

  In this embodiment, as shown in FIG. 1, the imaging unit 2 is moved by moving the adjustment table 8 to which the imaging unit 2 is fixed while the linear motion actuator 9 is in contact with the three movable parts 9a. The contact point between the receiving portion 8a of the adjustment table 8 and the three movable portions 9a is an action point 9p when the imaging unit 2 moves by the three movable portions 9a. For this reason, the stability of the adjustment accuracy depends on the contact structure between the receiving portion 8a and the movable portion 9a. Examples of the contact structure that can provide stable adjustment accuracy include various types as described below.

  FIG. 5 shows a specific example of a contact structure in which the movable portion 9a of the linear actuator 9 and the receiving portion 8a of the adjustment table 8 are in point contact. FIG. 5A shows a contact structure between the conical tip surface 9s of the movable portion 9a and the planar receiving surface 8s of the receiving portion 8a. The contact structure shown in FIGS. 1 and 4 is of this type. Since the action point 9p consists of the apex of a cone, the contact point is one point. FIG. 5B shows a contact structure between the spherical tip surface 9s of the movable portion 9a and the planar receiving surface 8s of the receiving portion 8a. Since the action point 9p is composed of a spherical vertex, the contact point is one point.

  5 (C) and 5 (D), conversely to FIGS. 5 (A) and 5 (B), the receiving portion 8a has a conical shape and a spherical shape. That is, FIG. 5C shows a contact structure between the planar tip surface 9s of the movable portion 9a and the conical receiving surface 8s of the receiving portion 8a, and FIG. A contact structure between a planar tip surface 9s of the movable portion 9a and a spherical receiving surface 8s of the receiving portion 8a is shown. Since the action point 8p is formed of a vertex of a cone or a spherical surface, the contact point is one point.

  FIG. 6 shows a specific example of a contact structure in which the movable portion 9a of the linear actuator 9 and the receiving portion 8a of the adjustment table 8 are in line contact with each other in a circular shape. The contact structure shown in FIGS. 6 (A) to 6 (D) is the contact structure shown in FIG. 5 (B) described above, in order to prevent lateral displacement of the adjustment table 8 (deviation substantially perpendicular to the optical axis AX). The spherical end surface 9s is configured to be provided in the receiving portion 8a in a hole 8h that makes a line contact in a circular shape. For example, in FIG. 6A, a cylindrical hole 8h is provided in the receiving portion 8a, and the spherical tip surface 9s is in line contact with the circular shape at the edge of the hole 8h of the receiving surface 8s. In FIG. 6B, a conical hole (sink hole) 8h is provided in the receiving portion 8a, and the spherical tip surface 9s is in line contact with the circular shape at the edge of the hole 8h of the receiving surface 8s. In FIG. 6C, a tapered hole 8h is provided in the receiving portion 8a, and the spherical tip surface 9s is in line contact with the circular shape at the receiving surface 8s which is the inner peripheral surface of the hole 8h. In FIG. 6D, a conical hole (sink hole) 8h is provided in the receiving portion 8a, and the spherical tip surface 9s is in line contact with the circular shape at the receiving surface 8s which is the inner peripheral surface of the hole 8h. To do. In contrast to the contact structure shown in FIG. 6, a spherical convex portion may be provided on the receiving portion 8a, and a hole may be provided on the distal end surface 9s of the movable portion 9a.

  As shown in FIGS. 5 and 6 described above, the contact between the adjustment table 8 and the three movable parts 9a is preferably a point contact or a circular line contact. When such a contact structure is employed, the movement of the adjustment table 8 can follow the movement of the movable portion 9a of the linear actuator 9 with high accuracy, so that the adjustment accuracy can be stabilized. If the contact between the adjustment table 8 and the three movable parts 9a is a surface contact, the contact position may change due to the inclination of the receiving surface, which may cause backlash.

  FIG. 7 shows a specific example of a contact structure in which three movable parts 9A, 9B, 9C are in contact with the first to third receiving parts 8A, 8B, 8C in different states. FIG. 7A is a plan view showing the adjustment table 8, and FIG. 7B shows the contact structure between the movable portions 9A, 9B, 9C and the receiving portions 8A, 8B, 8C, P in FIG. It is sectional drawing shown by a -P 'line cross section. The three movable portions 9A, 9B, and 9C have a spherical tip surface 9s, and the adjustment table 8 has first to third receiving portions 8A, 8B, and 8C that are in contact with the tip surfaces 9s. . The first receiving portion 8A has a circular hole hA, the second receiving portion 8B has a flat surface, and the third receiving portion 8C has a long hole hC.

  For example, when the contact structure shown in FIG. 6A is used at three locations, high-precision position adjustment is necessary so that the spherical tip surface 9s fits in the three locations with respect to the hole 8h. become. Further, if the contact state is not appropriate, there is a risk of looseness during adjustment. As described above, a hole hA, a flat surface (receiving surface 8s), and a long hole hC are provided in the first to third receiving portions 8A, 8B, and 8C, respectively, to form a contact structure with the movable portions 9A, 9B, and 9C. Then, since the positions of the movable portions 9A, 9B, 9C and the first to third receiving portions 8A, 8B, 8C are determined to be one, high-precision position adjustment is unnecessary, and the linear actuator 9 Since the movement of the adjustment table 8 can follow the movement of the movable portion 9a with high accuracy, stabilization of the adjustment accuracy can be achieved. It is preferable to form the long hole hC so as to be long in the direction in which the hole hA is provided in order to effectively suppress the occurrence of looseness during adjustment.

  FIG. 8 shows a specific example of a contact structure of a type in which the adjustment table 8 is urged toward the contact point of the movable portion 9 a of the linear actuator 9. The contact structure shown in FIG. 8 is the same as the contact structure shown in FIGS. 5 to 7 described above, in order to prevent the adjustment table 8 from being laterally displaced (a displacement in a direction substantially perpendicular to the optical axis AX). It is the structure which provided the tension | pulling spring 12 urged | biased toward this contact point. Due to the urging force of the tension spring 12, the receiving portion 8a and the movable portion 9a are held in a more stable close contact state, so that the lateral displacement of the adjustment table 8 can be effectively prevented.

  FIG. 9 shows another specific example of the contact structure in which the adjustment table 8 is urged toward the contact point of the movable portion 9 a of the linear actuator 9. The contact structure shown in FIG. 9 is the same as the contact structure shown in FIGS. 5 to 7 described above, and the adjustment table 8 is moved to the movable portion 9a in order to prevent lateral displacement of the adjustment table 8 (deviation substantially perpendicular to the optical axis AX). It is the structure which provided the leaf | plate spring 13 urged | biased toward this contact point. Since the receiving portion 8a and the movable portion 9a are held in a more stable close contact state by the urging force of the leaf spring 13, the lateral displacement of the adjustment table 8 can be effectively prevented. Further, the leaf spring 13 is fixed to the receiving portion 8a and the fixing portion 9b with screws 14, and the height of the rotation fulcrum at the time of tilt adjustment is adjusted by matching the height of the fixing portion of the leaf spring 13 with the imaging surface 2s. Therefore, there is obtained an effect that a deviation between the center of the imaging surface 2s and the center position of the optical axis AX of the lens unit 1 does not occur during tilt adjustment.

DESCRIPTION OF SYMBOLS 1 Lens unit 1a Shooting lens 2 Imaging unit 2a Imaging element 2s Imaging surface 3 Light source 4 Chart 5 Lens unit holding part 6 Imaging unit holding part 7 Probe unit 7a Contact probe 8 Adjustment table 8a Receiving part 8s Receiving surface 8p Action point 8h Hole 9 Linear actuator 9a Movable part 9b Fixed part 9s Tip surface 9p Action point 8A, 8B, 8C Receiving part 9A, 9B, 9C Movable part hA, hC Hole 10 Camera module 11 Personal computer (PC)
12 tension spring 13 leaf spring 20 manufacturing apparatus IM image plane L approximate plane of image plane (approximate image plane)
M Imaging plane AX Optical axis

Claims (20)

A method of manufacturing a camera module having a structure in which a lens unit having a photographing lens and an imaging unit having an imaging element are integrated,
A set step of arranging the lens unit and the imaging unit so that the imaging surface of the imaging element is positioned perpendicular to the optical axis of the imaging lens;
A measurement step of measuring an approximate plane of an image plane formed by the photographing lens as an approximate image plane by translating the imaging unit in the optical axis direction;
An adjustment step of moving the imaging unit such that a plane including the imaging plane is an imaging plane and any three points on the imaging plane are positioned on the approximate image plane by movement in the optical axis direction independent of each other;
A method for manufacturing a camera module.   The method of manufacturing a camera module according to claim 1, wherein action points when the imaging unit moves in the adjustment step coincide with arbitrary three points on the imaging plane.   2. The method of manufacturing a camera module according to claim 1, wherein an action point when the imaging unit moves in the adjustment step is located at a position where the arbitrary three points are translated in the optical axis direction.   The method of manufacturing a camera module according to claim 2, wherein the imaging surface is located within a triangle having the three arbitrary points as vertices.   In an orthogonal coordinate system (X, Y, Z) in which the optical axis of the photographing lens is the Z axis, arbitrary three points on the imaging plane are represented by A (X1, Y1,0), B (X2, Y2, 0). , C (X3, Y3, 0), three points corresponding to the points A, B, C in the approximate image plane: A ′ (X1, Y1, Z1), B ′ (X2, Y2, Z2), Z ′ of C ′ (X3, Y3, Z3): Z1, Z2, and Z3 are used as movement amounts so that the points A, B, and C are positioned on the approximate image plane by movement in the Z direction independent of each other. The method of manufacturing a camera module according to claim 1, wherein the imaging unit is moved in the adjustment step.   6. The method of manufacturing a camera module according to claim 5, wherein action points when the imaging unit moves in the adjustment step coincide with arbitrary three points A, B, and C on the imaging plane.   The method of manufacturing a camera module according to claim 6, wherein the imaging surface is located in a triangle having the three points A, B, and C as vertices. A camera module manufacturing apparatus having a structure in which a lens unit having a photographing lens and an imaging unit having an imaging element are integrated,
A linear actuator having three movable parts movable independently of each other in the optical axis direction of the photographing lens;
By moving the image pickup unit arranged so that the image pickup surface of the image pickup device is perpendicular to the optical axis in the optical axis direction by the three movable parts of the linear motion actuator, Measure the approximate plane of the formed image plane as an approximate image plane,
The plane including the imaging plane is defined as an imaging plane, and the three movable actuators are moved so that any three points on the imaging plane are positioned on the approximate image plane by movement in the optical axis direction independent of each other. An apparatus for manufacturing a camera module, wherein the imaging unit is moved by a unit.   9. The apparatus for manufacturing a camera module according to claim 8, wherein an action point when the imaging unit is moved by the three movable parts coincides with any three points on the imaging plane.   9. The apparatus for manufacturing a camera module according to claim 8, wherein an action point when the imaging unit is moved by the three movable parts is located at a position where the arbitrary three points are translated in the optical axis direction. .   11. The apparatus for manufacturing a camera module according to claim 9, wherein the imaging surface is located within a triangle having the arbitrary three points as apexes.   In an orthogonal coordinate system (X, Y, Z) in which the optical axis of the photographing lens is the Z axis, arbitrary three points on the imaging plane are represented by A (X1, Y1,0), B (X2, Y2, 0). , C (X3, Y3, 0), three points corresponding to the points A, B, C in the approximate image plane: A ′ (X1, Y1, Z1), B ′ (X2, Y2, Z2), Z ′ of C ′ (X3, Y3, Z3): Z1, Z2, and Z3 are used as movement amounts so that the points A, B, and C are positioned on the approximate image plane by movement in the Z direction independent of each other. 9. The camera module manufacturing apparatus according to claim 8, wherein the imaging unit is moved by three movable parts.   13. The apparatus for manufacturing a camera module according to claim 12, wherein action points when the imaging unit moves by the three movable parts coincide with arbitrary three points A, B, and C on the imaging plane. .   14. The camera module manufacturing apparatus according to claim 13, wherein the imaging surface is located within a triangle having the three points A, B, and C as vertices.   The image pickup unit further includes an adjustment table to which the image pickup unit is fixed. The image pickup unit is moved by moving the adjustment table while the linear motion actuator is in contact with the three movable parts. 15. The camera module manufacturing apparatus according to claim 8, wherein the contact point with the movable part is an action point when the imaging unit moves with the three movable parts. .   16. The camera module manufacturing apparatus according to claim 15, wherein the contact between the adjustment table and the three movable parts is a point contact or a circular line contact.   The three movable parts have spherical tip surfaces, the adjustment table has first to third receiving parts that come into contact with the tip surfaces, and the first receiving part has a circular hole. The apparatus for manufacturing a camera module according to claim 15, wherein the second receiving part is formed of a flat surface, and the third receiving part has an elongated hole.   The camera module manufacturing apparatus according to any one of claims 15 to 17, further comprising a spring that urges the adjustment table toward a contact point of the movable portion.   19. The camera module manufacturing apparatus according to claim 18, wherein the spring is a tension spring.   19. The camera module manufacturing apparatus according to claim 18, wherein the spring is a leaf spring.

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