JP2012027063A - Manufacturing method of camera module, and lens unit of camera module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a camera module in which an alignment mark can be accurately discriminated even without providing a special component, and the optical axis of an imaging lens and the center of an imaging device can be surely aligned.SOLUTION: The manufacturing method of a camera module for jointing a lens unit having an imaging lens to an imaging device unit having an imaging device includes: a step of holding, with a holding member movable to a desired position, a part of the lens unit positioned on the opposite side of the imaging device unit; a step of picking up an discrimination member exposed to the side of the imaging device unit with an imaging apparatus and, based on the image of the picked up discrimination member, and detecting the shift amount of the optical axis of the imaging lens from the central axis of the holding member on the basis of the picked-up image of the discrimination member; a step of moving, by the travel amount corrected on the basis of the shift amount, the lens unit above the imaging device unit disposed at a prescribed position; and a step of moving the lens unit toward the imaging device unit to joint the lens unit to the imaging device unit.

Description

  The present invention relates to a camera module manufacturing method for manufacturing a camera module by aligning the optical axis of an imaging lens with the center of an image sensor, and a lens unit of a camera module capable of such manufacturing.

  Conventionally, a small and thin camera module is mounted on a portable terminal, which is a small and thin electronic device such as a mobile phone or a PDA (Personal Digital Assistant), thereby enabling not only audio information but also image transmission to a remote place. Information can also be transmitted to each other.

  The camera module includes a lens unit having an image pickup lens and an image pickup element unit having an image pickup element, and is formed by joining the two. The lens unit is provided with an actuator or the like for driving the imaging lens during focusing. On the other hand, a CCD image sensor (Charge Coupled Device), a CMOS image sensor (Complementary Metal-Oxide Semiconductor), or the like is used as the imaging device, and is mounted on a printed wiring board provided in the imaging device unit.

  Since the camera module is very small, the lens unit and the image sensor unit are joined using a transfer robot during manufacture. At this time, if the optical axis of the imaging lens and the center of the imaging device do not match, the optical performance, for example, the resolution and the brightness of the peripheral portion of the captured image will not be uniform, and the image quality will deteriorate. Therefore, it is necessary to operate the transport robot so that the optical axis of the imaging lens and the center of the imaging element coincide.

  For this purpose, Japanese Patent Application Laid-Open No. 2003-260260 discloses an imaging apparatus that provides an alignment mark on a light-transmitting substrate and aligns the optical axis of the imaging lens with the center of the imaging element using the alignment mark as an aiming mark. reference).

JP 2001-203913 A

  Although the shape of the alignment mark is not described in detail in Patent Document 1, it is usually formed in a convex shape or a concave shape by a mold or the like. Then, when the camera module is assembled, the alignment mark is imaged, the amount of deviation of the imaged alignment mark with respect to the reference position of the image is detected, and the amount of deviation is corrected to match the optical axis of the imaging lens with the center of the image sensor. ing.

  The member for forming the alignment mark is not limited to the translucent substrate as in Patent Document 1, and may be a lens frame, for example. However, if the alignment mark is formed integrally with a predetermined member, the alignment mark is a peripheral portion. And gloss and color are the same and difficult to identify. In addition, it is possible to embed different members with different glossiness and color as alignment marks so that they can be easily identified, but this is not a good idea because the cost is increased due to parts costs and assembly costs. Further, when the alignment mark is imaged in the manufacturing process, the alignment mark is illuminated to ensure sufficient illuminance. At this time, if the alignment mark is formed in a convex shape or a concave shape, a shadow due to illumination occurs, and accurate identification is difficult.

  The present invention has been made in view of such a problem, and can accurately identify an alignment mark without providing a special member, and can reliably match the optical axis of the imaging lens with the center of the imaging element. It is an object of the invention to propose a module manufacturing method and a camera module lens unit capable of such manufacturing.

  The above object is achieved by the invention described below.

1. A camera module manufacturing method for manufacturing a camera module by bonding a lens unit having an imaging lens and an identification member exposed on the imaging element unit side to an imaging element unit having an imaging element,
Holding a portion of the lens unit located on the opposite side of the imaging element unit with a holding member movable to a desired position;
Imaging the identification member with an imaging device, and detecting a shift amount in which the optical axis of the imaging lens is deviated from the central axis of the holding member based on the captured image of the identification member;
Moving the lens unit above an image sensor unit arranged at a predetermined position with a movement amount corrected based on the shift amount;
Moving the lens unit toward the image sensor unit, and joining the lens unit to the image sensor unit;
A method for manufacturing a camera module, comprising:

  2. The identification member is exposed from a hole provided in a frame member that covers at least a portion on the image sensor side, and the identification member and the frame member are different in at least one of gloss and color. A manufacturing method of the camera module according to 1.

  3. 3. The camera module according to 2, wherein an end surface of the identification member on the image sensor unit side is disposed so as to be substantially flush with a surface of the frame member on the image sensor unit side. Production method.

  4). 4. The method of manufacturing a camera module according to any one of 1 to 3, wherein the shape of the exposed end face of the identification member is a quadrangle.

  5. 5. The camera module manufacturing method according to any one of 1 to 4, wherein the identification member is an actuator that drives the imaging lens.

6). A lens unit of a camera module having an imaging lens and joined to an imaging element unit having an imaging element,
A lens unit of a camera module, comprising an identification member exposed on the image sensor unit side.

  7). The identification member is exposed through a hole provided in a frame member that covers at least a portion on the image sensor unit side, and the identification member and the frame member are different in at least one of gloss and color. 7. The lens unit of the camera module as described in 6 above.

  8). 8. The camera module according to claim 7, wherein an end surface of the identification member on the imaging element unit side is disposed so as to be substantially flush with a surface of the frame member on the imaging element unit side. Lens unit.

  9. The lens unit of the camera module according to any one of 6 to 8, wherein the shape of the exposed end face of the identification member is a quadrangle.

  10. The lens unit of the camera module according to any one of 6 to 9, wherein the identification member is an actuator that drives the imaging lens.

  According to the camera module manufacturing method of the present invention and the lens unit of the camera module, the alignment mark can be accurately identified without providing any special member, and the optical axis of the imaging lens and the center of the imaging element are reliably matched. Can be made.

It is sectional drawing of a camera module. It is the perspective view which looked at the lens unit from the image sensor unit side. It is a figure which moves a lens unit with a conveyance robot. It is the schematic of the system which moves a lens unit with a conveyance robot. It is a figure which joins a lens unit to an image sensor unit with a conveyance robot. It is sectional drawing of the camera module of a different form.

  First, an example of a camera module according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the camera module, and FIG. 2 is a perspective view of the lens unit as viewed from the image sensor unit side.

  As shown in FIG. 1, the camera module includes a lens unit 1 and an image sensor unit 2.

  In the lens unit 1, the imaging lens L is held by the lens barrel 11, and the actuator 12 (identification member) is held by the lens frame 13 (frame member). The actuator 12 drives the lens barrel 11 in the direction of the optical axis O together with the imaging lens L during focusing. For example, a coil is incorporated and covered with a metal cover such as aluminum. The lens frame 13 is made of a black resin.

  In the image pickup device unit 2, an image pickup device 21 including a CCD image sensor or a CMOS image sensor is mounted on a printed wiring board 22, and the printed wiring board 22 is joined to an end portion of a sensor cover 23. A filter F is disposed between the imaging lens L and the imaging element 21 and is fixed to the sensor cover 23.

  One end of the actuator 12 is inserted into a hole 13b formed in the back surface 13a of the lens frame 13 on the image sensor unit 2 side, and the end surface 12a is exposed to the image sensor unit 2 side. The end surface 12a of the actuator 12 is disposed so as to be substantially flush with the back surface 13a of the lens frame 13.

  As will be described later, since the position of the optical axis O of the imaging lens L is detected by imaging the actuator 12 as an alignment mark, the position of the end surface 12a of the actuator 12 is arranged with high accuracy so as not to vary. .

  As shown in FIG. 2, the exposed end surface 12 a of the actuator 12 has a quadrangular shape, and four, for example, are arranged at an equal distance from the optical axis O of the imaging lens L.

  As shown in the enlarged view, in actual manufacture, a fine gap is formed between the actuator 12 and the hole 13b. By filling this gap with a transparent adhesive, dust enters the image sensor unit 2. It is possible to prevent image defects from occurring. Note that, by using a transparent adhesive, even when the adhesive is raised, a shadow due to the adhesive is less likely to occur when the actuator 12 is illuminated.

  When the lens unit 1 and the image sensor unit 2 configured as described above are manufactured and bonded together with the adhesive G, the camera module is completed.

  This joining is automatically performed by the operation of the transport robot. At this time, it is necessary to match the optical axis O of the imaging lens L with the center of the imaging element 21.

  Hereinafter, a manufacturing method for joining the lens unit 1 to the image sensor unit 2 by operating the transport robot so that the optical axis of the image pickup lens L coincides with the center of the image sensor 21 will be described with reference to FIGS. . FIG. 3 is a diagram for moving the lens unit by the transport robot, FIG. 4 is a schematic diagram of a system for moving the lens unit by the transport robot, and FIG. 5 is a diagram for joining the lens unit to the image sensor unit by the transport robot.

  In FIG. 3, reference numeral 51 denotes a holding member connected to the robot arm 641 of the transfer robot 64, and the lens unit 1 is sucked and held through a plurality of suction holes 51a for sucking air and moved.

  First, the holding member 51 holds the lens unit 1 disposed at a predetermined position by adsorbing a portion of the lens unit 1 located on the opposite side of the imaging element unit 2. In general, when the holding member 51 holds the lens unit 1, the central axis C1 of the holding member 51 and the optical axis O of the imaging lens L do not coincide with each other. Suppose that

  The holding member 51 that has attracted the lens unit 1 is moved above the imaging device 61 by the transport robot 64. At this position, the imaging device 61 images the image sensor unit 2 side of the lens unit 1. The end surface 12a of the actuator 12 exposed at this time is also imaged. The end face 12a of the actuator 12 is a part of a metal cover made of aluminum or the like and has a glossy metallic color, and the surrounding lens frame 13 is made of a black and low gloss resin. Therefore, since the actuator 12 is different in color and gloss from its periphery, the end face 12a of the actuator 12 can be clearly identified from the captured image. In addition, four actuators 12 are arranged equidistantly from the optical axis O of the imaging lens L and are quadrangular. Therefore, the center position of the actuator 12, that is, the optical axis O of the imaging lens L is determined from the images of these actuators 12. The position can be recognized accurately. On the other hand, the position at which the holding member 51 moves above the imaging device 61 is always constant, and the central axis C1 of the holding member 51 matches the lens optical axis of the imaging device 61.

  Although it is desirable to increase the illuminance by performing predetermined illumination at the time of imaging, the rear surface 13a of the lens frame 13 and the end surface 12a of the actuator 12 are arranged so as to be substantially flush with each other. Shadows do not occur and the image is not adversely affected.

  Thus, in order to detect the position of the optical axis O of the imaging lens L of the lens unit 1, the actuator 12 that is different in color and gloss with respect to the periphery is imaged as an alignment mark. It is possible to detect the position with higher accuracy compared with the case where the alignment mark is formed integrally.

  Therefore, the alignment recognition device 62 connected to the imaging device 61 as shown in FIG. 4 detects the shift amount d between the central axis of the holding member 51 and the optical axis O of the imaging lens L based on the image captured by the imaging device 61. can do.

  The detected deviation amount d data is sent to the robot controller 63, which controls the transfer robot 64, which allows the holding member 51 to move to an arbitrary three-dimensional position.

  Therefore, the transport robot 64 moves the lens unit 1 by the holding member 51 and moves it above the position where the image sensor unit 2 is disposed. At this time, since the movement is performed in consideration of the shift amount d, the optical axis O of the imaging lens L coincides with the center C2 of the imaging element 21.

  In FIG. 3, in the state of the left figure, the optical axis O of the imaging lens L is displaced from the central axis C1 of the holding member 51 by a deviation amount d in a direction far from the right figure. If the movement amount of the holding member 51 moving from the left figure to the right figure when there is no deviation is D, if the holding member 51 is moved by D + d, the optical axis O and the center C2 coincide.

  The image sensor unit 2 is arranged on the pedestal 71 by the device in the previous process so that the center C2 of the image sensor 21 is always at a fixed position.

  Further, an adhesive G is dropped on the end of the image sensor unit 2 on the lens unit 1 side of the sensor cover 23.

  Thereafter, the holding member 51 moves the lens unit 1 toward the image sensor unit 2 by the transport robot 64 and joins the lens unit 1 to the image sensor unit 2 with an adhesive G as shown in FIG.

  In the embodiment described above, the number of the holding members 51 is not necessarily four, and the position can be detected by one or two, and conversely, the number may be five or more. Considering productivity, 3-4 pieces are desirable.

  In addition, it is preferable to form the holding member 51 in a quadrangle because it is possible to reduce an error in the rotation direction. However, the holding member 51 is not necessarily limited to a quadrangle. .

  In addition, the identification member that captures an image as an alignment mark for detecting the position of the optical axis O is not necessarily limited to the actuator 12, and any member that is exposed on the imaging element 21 side so as to be identifiable may be used. A leaf spring or the like that biases the lens frame 13 in one direction may be used. In short, it is sufficient that the identification member is different from the surrounding members to such an extent that at least one of gloss and color can be recognized.

  In addition, the above-described holding member 51 sucks and holds the lens unit 1, but may hold it in any way, for example, a robot hand may be used.

  Next, a camera module having a different form from the above is shown in the sectional view of FIG.

  In this figure, the end face 32a of the actuator 32 protrudes from the back surface 13a of the lens frame 13 to the image pickup device unit 2 side. The end surface 32 a of the actuator 32 is in contact with the surface 23 a of the sensor cover 23 on the lens unit 1 side. Thereby, the lens unit 1 and the image sensor unit 2 are accurately positioned in the direction of the optical axis O, and thus the lens unit 1 and the image sensor unit 2 can be prevented from being inclined with respect to each other.

  Note that the end surface 32a is preferably formed by chamfering the end portion of the actuator 32, thereby preventing a shadow from being generated during illumination.

DESCRIPTION OF SYMBOLS 1 Lens unit 12, 32 Actuator 12a, 32a End surface 13 Lens frame 2 Imaging device unit 21 Imaging device 23 Sensor cover 51 Holding member 61 Imaging device 62 Alignment recognition device 63 Robot controller 64 Transport robot 641 Robot arm 71 Base L Imaging lens O Light Axis C1 Center axis C2 Center d Deviation G Adhesive

Claims (10)

A camera module manufacturing method for manufacturing a camera module by bonding a lens unit having an imaging lens and an identification member exposed on the imaging element unit side to an imaging element unit having an imaging element,
Holding a portion of the lens unit located on the opposite side of the imaging element unit with a holding member movable to a desired position;
Imaging the identification member with an imaging device, and detecting a shift amount in which the optical axis of the imaging lens is deviated from the central axis of the holding member based on the captured image of the identification member;
Moving the lens unit above an image sensor unit arranged at a predetermined position with a movement amount corrected based on the shift amount;
Moving the lens unit toward the image sensor unit, and joining the lens unit to the image sensor unit;
A method for manufacturing a camera module, comprising:   The identification member is exposed through a hole provided in a frame member that covers at least a portion on the imaging element side, and the identification member and the frame member are different in at least one of gloss and color. Item 2. A method for manufacturing a camera module according to Item 1.   3. The camera module according to claim 2, wherein an end surface of the identification member on the image sensor unit side is disposed so as to be substantially flush with a surface of the frame member on the image sensor unit side. Manufacturing method.   The method of manufacturing a camera module according to claim 1, wherein the shape of the exposed end face of the identification member is a quadrangle.   The method of manufacturing a camera module according to claim 1, wherein the identification member is an actuator that drives the imaging lens. A lens unit of a camera module having an imaging lens and joined to an imaging element unit having an imaging element,
A lens unit of a camera module, comprising an identification member exposed on the image sensor unit side.   The identification member is exposed through a hole provided in a frame member that covers at least a portion on the image sensor unit side, and the identification member and the frame member are different in at least one of gloss and color. The lens unit of the camera module according to claim 6.   8. The camera module according to claim 7, wherein an end surface of the identification member on the image sensor unit side is disposed so as to be substantially flush with a surface of the frame member on the image sensor unit side. Lens unit.   The lens unit of the camera module according to any one of claims 6 to 8, wherein the shape of the exposed end face of the identification member is a quadrangle.   The lens unit of the camera module according to claim 6, wherein the identification member is an actuator that drives the imaging lens.

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