Manufacturing method of imaging module

A manufacturing method of an imaging module and an imaging module manufacturing apparatus capable of performing positioning of an imaging element unit and a lens unit with high accuracy are provided. A manufacturing apparatus 200 holds a lens unit 10 and an imaging element unit 20 on a Z axis, and images a measurement chart by an imaging element 27 in a state where a probe 113a comes into contact with each of terminals 14A to 14F electrically connected to an x-direction VCM 16A, a y-direction VCM 16C, and a z-direction VCM 16E of the lens unit 10 and electricity flows to a lens drive unit 16 inside the lens unit 10. A contactor of the probe 113a is configured of a non-magnetic material.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a manufacturing method of an imaging module and an imaging module manufacturing apparatus.

2. Description of the Related Art

A small and thin imaging module is mounted on a portable electronic device such as a portable phone having an imaging function. The imaging module has a structure in which a lens unit, into which an imaging lens is incorporated, and an imaging element unit into which an imaging element such as a CCD image sensor or a CMOS image sensor is incorporated are integrated with each other.

As the imaging module, there is an imaging module which has an auto focus (AF) mechanism which moves a lens in the lens unit for performing focus adjustment, and an imaging module which has an optical type image blur correction mechanism which relatively moves the lens unit and the imaging element unit in a direction orthogonal to an optical axis for optically correcting blur of a captured image.

For example, JP2010-21985A discloses the imaging module having the AF mechanism. In addition, JP2012-256017 discloses the imaging module having the AF mechanism and the optical type image blur correction mechanism.

In recent years, in an imaging element which is used in an imaging module, not only imaging elements having a low pixel number such as approximately one million pixels to two million pixels but also imaging elements having a high pixel number such as three million pixels to ten million pixels or more are widely used.

In a case where the imaging element of a low pixel number is used, particularly, high accuracy is not required for positioning of the lens unit and the imaging element unit. However, in a case where the imaging element having a high pixel number is used, high accuracy is required for the positioning.

JP2010-21985A discloses a technology in which the lens unit and the imaging element unit are fixed to each other after the positioning of the lens unit and the imaging element unit is performed.

In JP2010-21985A, after the lens unit and the imaging element unit are set to an initial position, in a state where a probe comes into contact with the lens unit and electricity flows to the lens unit, a chart is imaged by the imaging element while the imaging element unit moves in a direction of an optical axis, and the positions of the lens unit and the imaging element unit are adjusted from the obtained captured image. After the adjustment, the lens unit and the imaging element unit are bonded and fixed to each other.

JP2012-256017A discloses that a pseudo sensor cover formed of a non-magnetic body is used so as to position a lens barrel in a lens unit when the lens unit is manufactured before the lens unit and an imaging element unit are fixed to each other.

JP2009-210443A and JP2012-122905A disclose that a contact probe formed of a non-magnetic material such as beryllium copper is used as an inspection contact probe used for conduction testing of an electronic component.

SUMMARY OF THE INVENTION

As in JP2012-256017A, in an imaging module having an optical type image blur correction mechanism, a lens barrel included in a lens unit is configured so as to be movable in a direction perpendicular to an optical axis. In addition, in a case where a voice coil motor (VCM) is used as an actuator, a permanent magnet is included in the optical type image blur correction mechanism. Accordingly, when the lens unit and the imaging element unit are positioned, since an attractive force is generated between the permanent magnet included in the lens unit and a magnetic body of a device side, it is necessary to prevent deviation of a lens optical axis inside the lens unit.

JP2012-256017A discloses that a tool used for manufacturing the lens unit is formed of a non-magnetic body such that an attractive force is not generated between the permanent included in the lens unit and the tool when the lens unit is manufactured. However, in JP2012-256017A, occurrence of the deviation in the lens optical axis in a process, in which the lens unit and the imaging element unit are positioned after the lens unit is manufactured, is not considered.

The present invention is made in consideration of the above-described circumstances, and an object thereof is to provide a manufacturing method of an imaging module and an imaging module manufacturing apparatus capable of accurately determining a position of an imaging element when the imaging element unit and a lens unit are positioned so as to improve imaging quality.

According to an aspect of the present invention, there is provided a manufacturing method of an imaging module having a lens unit which has a lens group, and an imaging element unit which is fixed to the lens unit and has an imaging element which images a subject through the lens group, in which the lens unit has a lens drive unit which includes two lens driving units which respectively move at least a portion of lenses of the lens group in two directions orthogonal to an optical axis of the lens group, a housing which accommodates the lens group and the lens drive unit, and an electric connection portion which is exposed from the housing and is electrically connected to the lens drive unit, the two lens driving units have voice coils and magnets facing the voice coils, and the manufacturing method comprises: a first process of, on an axis orthogonal to a measurement chart, changing relative positions of at least one or more of the imaging element unit, the lens unit, and the measurement chart in the direction of the axis, and driving the imaging element and imaging the measurement chart through the lens group by the imaging element at each relative position; and a second process of adjusting at least an inclination of the imaging element unit with respect to the lens unit based on imaging signals obtained by imaging the measurement chart by the imaging element, and fixing the imaging element unit to the lens unit, and in the first process, the lens unit is held on the axis, and the measurement chart is imaged by the imaging element in a state where a contactor of a first probe having the contactor including a main body formed of a non-magnetic material is pressed to the electric connection portion of the lens unit and electricity flows to the lens drive unit.

According to another aspect of the present invention, there is provided an imaging module manufacturing apparatus, comprising: a measurement chart installation portion for installing a measurement chart; an imaging element unit holding portion for holding an imaging element unit having an imaging element which images a subject through a lens unit having a lens group, on an axis orthogonal to the measurement chart installed on the measurement chart installation portion; a lens unit holding portion for holding the lens unit on the axis between the measurement chart installation portion and the imaging element unit holding portion; a first probe pressing portion which presses a contactor of a first probe having the contactor including a main body formed of a non-magnetic material to the lens unit held by the lens unit holding portion; a control unit which changes relative positions of at least one or more of the measurement chart installation portion, the lens unit holding portion, and the imaging element unit holding portion in the direction of the axis, and drives the imaging element of the imaging element unit and images the measurement chart through the lens unit by the imaging element at each relative position; an adjustment portion which adjusts at least an inclination of the imaging element unit with respect to the lens unit based on imaging signals obtained by imaging the measurement chart by the imaging element; and a unit fixing portion which fixes the imaging element unit adjusted by the adjustment portion to the lens unit.

According to the present invention, it is possible to provide a manufacturing method of an imaging module and an imaging module manufacturing apparatus capable of accurately determining a position of an imaging element when the imaging element unit and a lens unit are positioned so as to improve imaging quality.

EXPLANATION OF REFERENCES

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1is an external perspective view of an imaging module100.

The imaging module100comprises a lens unit10which has a lens group12, and an imaging element unit20which is fixed to the lens unit10and has an imaging element (not shown inFIG. 1) which images a subject through the lens group12.

InFIG. 1, a direction along an optical axis Ax of the lens group12is defined as a z direction, and two directions which are orthogonal to the z direction and are orthogonal to each other are defined as an x direction and a y direction, respectively.

The lens unit10comprises a housing11in which components described below are accommodated.

An opening11bwhich has the optical axis Ax of the lens group12as the center is formed on a top surface11aof the housing11. The imaging module100receives light of a subject through the lens group12from the opening11b, and performs imaging.

In addition, positioning concave sections95A,95B, and95C for holding the lens unit10to a manufacturing apparatus when the imaging module100is manufactured are formed on the top surface11aof the housing11. Concave sections95A1and95C1which are smaller than the concave sections95A and95C are formed on bottom surfaces of the concave sections95A and95C positioned on a diagonal line on the top surface11a.

A portion of a flexible substrate13accommodated in the housing11is exposed outside the housing11. A lens unit terminal portion14including terminals14A to14F is connected to the distal end of the exposed portion of the flexible substrate13. The lens unit terminal portion14is exposed from a surface except for the top surface11awhich is the surface orthogonal to the z direction, among surfaces configuring the housing11.

In addition, as described below, the lens unit terminal portion14includes other terminals in addition to the terminals14A to14F. However, inFIG. 1, for simplification, only the terminals14A to14F are shown, and other terminals are not shown.

FIG. 2is an external perspective view showing a state where the lens unit10is omitted in the imaging module100shown inFIG. 1.

As shown inFIG. 2, the imaging element unit20comprises a substrate21on which an imaging element27such as a CCD image sensor or a CMOS image sensor is formed, and a flexible substrate22which is electrically connected to the substrate21.

A pixel pitch of the imaging element27is not particularly limited. However, an imaging element having a pixel pitch of 1.0 μm or less is used as the imaging element27. Here, the pixel pitch means the minimum distance among distances between centers of photo-electrically converted regions included in pixels provided in the imaging element27.

In recent years, the pixel pitch of the imaging element has decreased according to an increase of a pixel number. However, if the pixel pitch decreases, an area per one pixel decreases. Accordingly, a radius of an allowable circle of confusion decreases, and a focal depth decreases. In addition, since it is necessary to increase a condensed light amount per one pixel, an F-number of the lens is likely to be decreased.

Accordingly, in recent years, since the focal depth of the imaging module is very small, it is necessary to perform positioning of the lens unit and the imaging element unit with high accuracy. Particularly, if the pixel pitch is 1 μm or less, high positioning accuracy is required.

A tubular cover holder25is formed on the substrate21, and the imaging element27is disposed inside the cover holder25. A cover glass (not shown) is fitted to the upper portion of the imaging element27in a hollow portion of the cover holder25.

An imaging element unit terminal portion including terminals24A to24F for electrically connecting to the lens unit10is provided on the surface of the substrate21on the outside of the cover holder25. Similarly to the lens unit terminal portion14, in the imaging element unit terminal portion, only some terminals are shown.

An imaging element wire, which is connected to a data output terminal, a drive terminal, or the like of the imaging element27, is provided on the substrate21. The imaging element wire is connected to an external connection terminal portion23, which is provided on the end portion of the flexible substrate22, via a wire provided on the flexible substrate22. The external connection terminal portion23functions as an electric connection portion which is electrically connected to the imaging element27.

In addition, a lens unit wire, which is connected to each terminal included in the imaging element unit terminal portion, is provided on the substrate21. The lens unit wire is connected to the external connection terminal portion23, which is provided on the end portion of the flexible substrate22, via the wire provided on the flexible substrate22.

In a state where the lens unit10and the imaging element unit20are fixed, each terminal of the lens unit terminal portion and each terminal of the imaging element unit terminal portion corresponding to each terminal of the lens unit terminal portion are electrically connected to each other.

InFIG. 1, the terminal14A and the terminal24A are electrically connected to each other, the terminal14B and the terminal24B are electrically connected to each other, the terminal14C and the terminal24C are electrically connected to each other, the terminal14D and the terminal24D are electrically connected to each other, the terminal14E and the terminal24E are electrically connected to each other, and the terminal14F and the terminal24F are electrically connected to each other.

FIG. 3is a sectional view taken along line A-A of the imaging module100shown inFIG. 1.

As shown inFIG. 3, the imaging element27is disposed in a concave section provided on the substrate21, and is sealed by the cover holder25provided on the substrate21and a cover glass26fitted to the cover holder25.

In addition, the lens unit10comprises the lens group12which includes a plurality of lenses (four lenses12A to12D in the example ofFIG. 3) disposed above the cover glass26, a tubular lens barrel15which supports the lens group12, a bottom block19which is placed on the upper surface of the cover holder25of the imaging element unit20, the flexible substrate13which is fixed to the bottom block19, the lens unit terminal portions (only the terminal14C is shown sinceFIG. 3is a sectional view) which are connected to the flexible substrate13, and a lens drive unit16which is formed on the flexible substrate13.

The lens group12, the lens barrel15, the bottom block19, the flexible substrate13, and the lens drive unit16are accommodated in the housing11.

The lens drive unit16comprises a first lens driving unit, a second lens driving unit, a third lens driving unit, and a hall element which is a position detection element for detecting the position of the lens.

The first lens driving unit is a driving unit which moves at least a portion (all lenses of the lens group12in the example ofFIG. 3) of the lenses of the lens group12in a first direction (z direction inFIG. 1) along the optical axis Ax of the lens group12so as to perform focus adjustment.

The second lens driving unit is a driving unit which moves at least a portion (all lenses of the lens group12in the example ofFIG. 3) of the lenses of the lens group12in a second direction (x direction inFIG. 1) orthogonal to the optical axis Ax of the lens group12so as to correct blur of an image captured by the imaging element27.

The third lens driving unit is a driving unit which moves at least a portion (all lenses of the lens group12in the example ofFIG. 3) of the lenses of the lens group12in a third direction (y direction inFIG. 1) orthogonal to the optical axis Ax of the lens group12so as to correct blur of an image captured by the imaging element27.

Each of the first lens driving unit, the second lens driving unit, and the third lens driving unit is an actuator for moving the lens, and in the present embodiment, is configured of a voice coil motor (VCM).

As shown inFIG. 3, the first lens driving unit comprises a voice coil161which is fixed to the lens barrel15, a magnet162which is provided at a position facing the voice coil161, and a spring163which is fixed to each of the voice coil161and the magnet162.

In addition, each of the second lens driving unit and the third lens driving unit comprises a base160which is fixed to the flexible substrate13, a voice coil164which is fixed to the base160, a magnet165which is provided at a position facing the voice coil164and is fixed to the magnet162, and a spring166which is fixed to each of the voice coil164and the magnet165. In addition, the base160is used both in the second lens driving unit and the third lens driving unit.

A distance between the magnet165and the voice coil164in the direction of the optical axis Ax is fixed to a constant value by the spring166. Accordingly, if a drive current flows to the voice coil161configuring the first lens driving unit, in a state where the position of the magnet162in the direction of the optical axis Ax is fixed, the voice coil161and the lens barrel15fixed to the voice coil161move in the direction of the optical axis Ax.

If a drive current flows to the voice coil164configuring the second lens driving unit, the magnet165configuring the second lens driving unit and the magnet162fixed to the magnet165move in the x direction. A distance between the magnet162and the voice coil161in the direction orthogonal to the optical axis Ax is fixed to a constant value by the spring163. Accordingly, the magnet162moves in the x direction, and the lens group12moves in the x direction.

If a drive current flows to the voice coil164configuring the third lens driving unit, the magnet165configuring the third lens driving unit and the magnet162fixed to the magnet165move in the y direction. A distance between the magnet162and the voice coil161in the direction orthogonal to the optical axis Ax is fixed to a constant value by the spring163. Accordingly, the magnet162moves in the y direction, and the lens group12moves in the y direction.

In this way, in the lens unit10on which the lens drive unit16including the second lens driving unit and the third lens driving unit is mounted, the magnets162and165and the lens barrel15integrally move in the x direction or the y direction. Accordingly, the lens unit10has a structure in which the lens barrel15easily moves in the x direction and the y direction by an attractive force applied between the magnets162and165and a magnetic body if the magnetic body approaches the magnets162and165from the outside of the lens unit10.

FIG. 4is a block diagram showing an electric connection configuration of the lens unit10shown inFIG. 1.

As shown inFIG. 4, the lens drive unit16comprises an x-direction VCM16A (the second lens driving unit) for moving the lens group12in the x direction, an x-direction hall element16B for detecting a position of the lens group12in the x direction, a y-direction VCM16C (the third lens driving unit) for moving the lens group12in the y direction, a y-direction hall element16D for detecting a position of the lens group12in the y direction, a z-direction VCM16E (the first lens driving unit) for moving the lens group12in the z direction, and a z-direction hall element16F for detecting a position of the lens group12in the z direction.

Two terminals are formed on the x-direction VCM16A, and the two terminals are electrically connected to the terminal14A and the terminal14B via wires formed on the flexible substrate13, respectively.

Four terminals are formed on the x-direction hall element16B, and the four terminals are electrically connected to a terminal14a, a terminal14b, a terminal14c, and a terminal14dvia wires formed on the flexible substrate13, respectively.

Two terminals are formed on the y-direction VCM16C, and the two terminals are electrically connected to the terminal14C and the terminal14D via wires formed on the flexible substrate13, respectively.

Four terminals are formed on the y-direction hall element16D, and the four terminals are electrically connected to a terminal14e, a terminal14f, a terminal14g, and a terminal14hvia wires formed on the flexible substrate13, respectively.

Two terminals are formed on the z-direction VCM16E, and the two terminals are electrically connected to the terminal14E and the terminal14F via wires formed on the flexible substrate13, respectively.

Four terminals are formed on the z-direction hall element16F, and the four terminals are electrically connected to a terminal14i, a terminal14j, a terminal14k, and a terminal14lvia wires formed on the flexible substrate13, respectively.

In this way, each terminal of the lens unit terminal portion14functions as an electric connection portion which is electrically connected to the lens drive unit16of the lens unit10.

In addition, the number of required terminals with respect to each lens driving unit and each hall element is an example, and is not limited to the above-described number.

In the imaging module100configured as described above, first, the lens unit10and the imaging element unit20are separately manufactured. In addition, an adjustment process for positioning the lens unit10and the imaging element unit20is performed so that an image forming surface of the subject formed by the lens group12and an imaging surface of the imaging element27are coincident with each other, and thereafter, the lens unit10and the imaging element unit20are bonded and fixed to each other.

The adjustment process is performed by moving the imaging element unit20in a state where a predetermined state of the lens unit10is held by a manufacturing apparatus.

FIG. 5is a side view showing a schematic configuration of the manufacturing apparatus200of the imaging module100.

The imaging module manufacturing apparatus200adjusts the position and the inclination of the imaging element unit20with respect to the lens unit10, and the imaging module100is completed by fixing the imaging element unit20to the lens unit10after the adjustment.

The imaging module manufacturing apparatus200comprises a chart unit71, a collimator unit73, a lens positioning plate75, a lens holding mechanism77, an imaging element unit holding portion79, an adhesive supply portion81, an ultraviolet lamp83which is a light source, and a control unit85which controls the above-described components. The chart unit71, the collimator unit73, the lens positioning plate75, the lens holding mechanism77, and the imaging element unit holding portion79are disposed so as to be arranged in one direction on the surface87perpendicular to the gravity direction.

The chart unit71is configured of a box-shaped housing71a, a measurement chart89which is fitted into the housing71a, and a light source91which is incorporated into the housing71aand illuminates the measurement chart89from the rear surface of the measurement chart89with parallel light. For example, the measurement chart89is formed of a plastic plate having light diffusibility. The chart surface of the measurement chart89is parallel to the gravity direction. The chart unit71functions as a measurement chart installation portion for installing the measurement chart. The measurement chart89can be removed so as to be replaced with another measurement chart.

FIG. 6is a view showing the chart surface of the measurement chart89. The measurement chart89is formed in a rectangular shape, and each of a plurality of chart images CH1, CH2, CH3, CH4, and CH5is printed on the chart surface on which chart patterns are provided.

The plurality of chart images are the same as one another, and are so-called ladder-shaped chart patterns in which black lines are disposed with predetermined intervals therebetween. Each chart image is configured of horizontal chart images Px arranged in a horizontal direction of the image, and vertical chart images Py arranged in a vertical direction of the image.

The collimator unit73is disposed to face the chart unit71on a Z axis which is a perpendicular line with respect to the chart surface of the measurement chart89and is a line passing through a chart surface center89a.

The collimator unit73is configured of a bracket73awhich is fixed to a workbench87and a collimator lens73b.

The collimator lens73bcondenses the light radiated from the chart unit71, and causes the condensed light to enter the lens positioning plate75through an opening73cformed on the bracket73a. By adjusting a gap between the chart unit71and the collimator unit73, it is possible to dispose a virtual image position of the measurement chart89imaged by the lens unit10at an arbitrary distance (for example, an infinity position or a standard subject distance suitable for assumed imaging of the lens unit10).

The lens positioning plate75and the lens holding mechanism77configure a lens unit holding portion for holding the lens unit10on the Z axis between the chart unit71and the imaging element unit holding portion79.

The lens positioning plate75is formed so as to have stiffness, and includes an opening75cthrough which light condensed by the collimator unit73passes. The lens positioning plate75is disposed so as to face the collimator unit73on the Z axis.

FIG. 7is an explanatory view showing a state where the lens unit10and the imaging element unit20are held by the imaging module manufacturing apparatus200.

As shown inFIG. 7, three abutment pins93A,93B, and93C are provided around an opening75aon the surface of the lens holding mechanism77side of the lens positioning plate75.

Insertion pins93A1and93C1having smaller diameters than those of the abutment pins are provided on distal ends of two abutment pins93A and93C which are disposed on a diagonal line among the three abutment pins93A,93B, and93C.

The abutment pins93A,93B, and93C receive the concave sections95A,95B, and95C of the lens unit10shown inFIG. 1, and the insertion pins93A1and93C1are inserted into the concave sections95A1and95C1to position the lens unit10.

In this way, in a state where the lens unit10is positioned, the Z axis coincides with the optical axis Ax of the lens unit10.

Returning toFIG. 5, the lens holding mechanism77comprises a first slide stage99which is movable in the Z axis direction, and a holding plate114and a probe unit113which are provided on a stage portion99aof the first slide stage99.

The first slide stage99is an electric precision stage. In the first slide stage, a ball screw is rotated by rotation of a motor (not shown), and the stage portion99awhich engages with the ball screw moves in the Z axis direction. The first slide stage99is controlled by the control unit85.

The holding plate114holds the lens unit10such that the top surface of the housing11faces the chart unit71on the Z axis, and holds the lens unit10to the manufacturing apparatus200by moving the stage portion99ain the Z axis direction and pressing the holding plate114to the bottom block19of the lens unit10which is positioned by the lens positioning plate75.

The probe unit113has six probes113a(only one is shown inFIG. 5).

The first slide stage99moves in the Z axis direction, and the contactor of the probe113acomes into contact with each of the terminals14A to14F of the lens unit10in a state where the holding plate114is pressed to the bottom block19of the lens unit10. The probe unit113functions as a first probe pressing portion.

Electricity flows to each of the terminals14A to14F via the probe113a, and the probe unit113drives a first lens driving unit (z-direction VCM16E), a second lens driving unit (x-direction VCM16A), and a third lens driving unit (y-direction VCM16C).

Each probe113aincluded in the probe unit113is a spring type probe, and is configured so as to comprise a contactor for coming into contact with a portion to be contacted, a connector which is electrically connected to a circuit substrate inside the probe unit113, and an elastic body such as a spring which is provided between the contactor and the connector and biases the contactor. The contactor of the probe113ais formed of a non-magnetic material. The circuit substrate inside the probe unit113is electrically connected to a lens driving driver145described below.

The non-magnetic material may include beryllium copper, phosphor bronze, copper-silver alloy, tungsten, or the like. Since non-magnetic metal represented by the beryllium copper has high strength (hardness, toughness), it is possible to thin the contactor. Accordingly, preferably, the non-magnetic metal such as the beryllium copper may be used in a lens unit having a smaller terminal area.

Moreover, the contactor may be configured of a main body which is formed of a non-magnetic material, and a film which is coated on the surface of the main body and is formed of a material different from that of the main body.

For example, after a main body of a contactor is formed of beryllium copper, nickel plating is performed on the surface of the main body, and thereafter, gold plating is performed on the nickel-plated surface, and the contactor is used. Alternatively, after a main body of a contactor is formed of beryllium copper, nickel plating is performed on the surface of the main body, and thereafter, copper plating is performed on the nickel-plated surface, gold plating is performed on the copper-plated surface, and the contactor is used. Alternatively, after a main body of a contactor is formed of beryllium copper, hard gold plating is performed on the surface of the main body, and the contactor is used.

Due to the gold plating, conductivity and wear resistance of the contactor may be improved. In addition, due to the nickel plating, corrosion resistance, conductivity, solder property of the contactor may be improved. Moreover, due to the copper plating, corrosion resistance and conductivity of the contactor may be improved.

FIG. 8is a view showing a configuration example of the contactor of the probe113a.

A contactor800shown inFIG. 8includes a main body801which is formed of a non-magnetic material such as beryllium copper, a nickel-plated film802which is coated on the surface of the main body801, and a gold-plated film803which is coated on the surface of the nickel-plated film802.

Preferably, a thickness of the nickel-plated film802is 1 μm to 3 μm, and a thickness of the gold-plated film803is 0.01 μm to 0.1 μm. Due to the thicknesses, even in a case where the contactor800comes into contact with each terminal of the lens unit terminal portion14, an attractive force which is generated between the magnet inside the lens unit10and a magnetic material included in the contactor800can be almost eliminated.

The imaging element unit holding portion79holds the imaging element unit20on the Z axis. In addition, the imaging element unit holding portion79can change the position and the inclination of the imaging element unit20in the Z axis direction by the control of the control unit85.

Here, the inclination of the imaging element unit20means the inclination of the imaging surface27aof the imaging element27with respect to a plane orthogonal to the Z axis.

The imaging element unit holding portion79is configured of a chuck hand115which holds the imaging element unit20so that the imaging surface27afaces the chart unit71on the Z axis, a biaxial rotation stage119which holds an approximately crank-shaped bracket117to which the chuck hand115is attached, and adjusts the inclination of the imaging element unit20around two axes (horizontal X axis and vertical Y axis) orthogonal to the Z axis, and a second slide stage123which holds a bracket121to which the biaxial rotation stage119is attached, and moves the bracket121in the Z axis direction.

As shown inFIG. 7, the chuck hand115is configured of a pair of holding members115awhich is bent in an approximately crank shape, and an actuator115b(refer toFIG. 5) which moves the holding members115ain the X axis direction orthogonal to the Z axis. An outer frame of the imaging element unit20in inserted into the portion between the holding members115ato hold the imaging element unit20.

In addition, the chuck hand115positions the imaging element unit20which is held between the holding members115aso that the optical axis Ax of the lens unit10held by the lens unit holding portion including the lens positioning plate75and the lens holding mechanism77, and the center position of the imaging surface27aare coincident with each other.

In addition, when viewed from the Z axis direction, the chuck hand115positions the imaging element unit20which is held between the holding members115aso that each terminal of the imaging element unit terminal portion24of the imaging element unit20overlaps each terminal of the lens unit terminal portion14of the held lens unit10.

The biaxial rotation stage119is an electric twin-axis goino stage, and inclines the imaging element unit20in a θx direction around the X axis and a θy direction around the Y axis orthogonal to the Z axis and the X axis by the rotations of two motors (not shown) with the center position of the imaging surface27aas the rotation center. Accordingly, when the imaging element unit20is inclined in each direction, a positional relationship between the center position of the imaging surface27aand the Z axis is not misaligned.

The second slide stage123is an electric precision stage. In the second slide stage, a ball screw is rotated by rotation of a motor (not shown), and a stage portion123awhich engages with the ball screw moves in the Z axis direction. The bracket121is fixed to the stage portion123a.

A connector cable127, which is connected to the external connection terminal portion23provided on the distal end of the flexible substrate22of the imaging element unit20, is attached to the biaxial rotation stage119. Drive signals are input to the imaging element27through the connection cable127, or captured image signals output from the imaging element27are output through the connection cable127.

The adhesive supply portion81, and the ultraviolet lamp83which is light sources configure a unit fixing portion which fixes the lens unit10and the imaging element unit20.

After the adjustment with respect to the position and the inclination of the imaging element unit20with respect to the lens unit10ends, the adhesive supply portion81supplies an adhesive cured by light (here, as an example, ultraviolet curing type adhesive) to a gap between the lens unit10and the imaging element unit20.

The ultraviolet lamp83irradiates the ultraviolet curing type adhesive supplied to the gap with ultraviolet rays, and the adhesive is cured. Moreover, as the adhesive, in addition to the ultraviolet curing type adhesive, an instantaneous adhesive, a thermosetting adhesive, a natural curing adhesive, or the like may be used.

FIG. 9is a block diagram showing an internal configuration of the imaging module manufacturing apparatus200.

For example, the control unit85is a microcomputer which comprises a CPU, a ROM, a RAM, or the like, and controls each portion based on a control program stored in the ROM. In addition, an input unit131such as a keyboard or a mouse for performing various setting or a display unit133on which a setting content, an operation content, operation results, or the like are displayed is connected to the control unit85.

The lens driving driver145is a drive circuit for driving the lens drive unit16including the first lens driving unit, the second lens driving unit, and the third lens driving unit, and supplies a driving current to each of the first lens driving unit, the second lens driving unit, and the third lens driving unit via the probe unit113.

An imaging element driver147is a drive circuit for the imaging element27, and inputs driving signals to the imaging element27via the connector cable127.

A focusing coordinate value acquisition circuit149acquires focusing coordinate values at a high focusing degree in the Z axis direction with respect to a plurality of imaging positions (positions corresponding to chart images CH1, CH2, CH3, CH4, and CH5of the measurement chart89) which are set on the imaging surface27aof the imaging element27.

When the focusing coordinate values at the plurality of imaging positions are acquired, the control unit85controls the second slide stage123and sequentially moves the imaging element unit20to a plurality of measurement positions (Z0, Z1, Z2, . . . ) which are discretely set on the Z axis in advance.

In addition, the control unit85controls the imaging element driver147, and images each chart image of the plurality of chart images CH1, CH2, CH3, CH4, and CH5of the measurement chart89, which are formed by the lens group12at the measurement positions, on the imaging element27.

The focusing coordinate value acquisition circuit149extracts signals of the pixels corresponding to the plurality of imaging positions from imaging signals input via the connector cable127, and calculates an individual focusing evaluation value with respect to the plurality of imaging positions from the pixel signals. In addition, the measurement position when a predetermined focusing evaluation value is obtained with respect to each imaging position is set to the focusing coordinate value on the Z axis.

For example, as the focusing evaluation value, a Contrast Transfer Function (hereinafter, referred to as a CTF value) may be used. The CTF value is a value which indicates contrast of an image with respect to spatial frequency, and it is regarded that the focusing degree increases as the CTF value increases.

The focusing coordinate value acquisition circuit149calculates the CTF value in each of the plurality of directions set on an XY coordinate plane for each of the plurality of measurement positions (Z0, Z1, Z2, . . . ) set on the Z axis with respect to each of the plurality of imaging positions.

For example, as the direction in which the CTF value is calculated, a lateral direction of the imaging surface27ais set to the horizontal direction (X axis direction), a direction orthogonal to the horizontal direction is set to a vertical direction (Y axis direction), and an X-CTF value and a Y-CTF value which are the CTF values in the directions are calculated.

As a horizontal focusing coordinate value, the focusing coordinate value acquisition circuit149acquires coordinates (Zp1, Zp2, Zp3, Zp4, and Zp5) on the Z axis of the measurement position, at which the X-CTF value is the maximum, with respect to the plurality of imaging positions corresponding to the chart images CH1, CH2, CH3, CH4, and CH5. In addition, similarly, as a vertical focusing coordinate value, the focusing coordinate value acquisition circuit149acquires the coordinates on the Z axis at the measurement position at which the Y-CTF value is the maximum.

The horizontal focusing coordinate value and the vertical focusing coordinate value of each imaging position acquired from the focusing coordinate value acquisition circuit149are input to an imaging forming surface calculation circuit151.

The image forming surface calculation circuit151deploys a plurality of evaluation points, which are expressed by combining an XY coordinate value of each imaging position when the imaging surface27acorresponds to an XY coordinate plane and the horizontal focusing coordinate value and the vertical focusing coordinate value on the Z axis obtained for each imaging position, on a three-dimensional coordinate system in which the XY coordinate plane and the Z axis are combined. In addition, the image forming surface calculation circuit151calculates an approximate image forming surface, in which the three-dimensional coordinate system is expressed by one plane, based on relative positions of the evaluation points.

Information of the approximate image forming surface obtained from the image forming surface calculation circuit151is input to an adjustment value calculation circuit153.

The adjustment value calculation circuit153calculates an image forming surface coordinate value F1on the Z axis which is an intersection point between the approximate image forming surface and the Z axis, and XY direction rotation angles which are inclinations of the approximate image forming surface with respect to the XY coordinate plane around the X axis and the Y axis, and inputs the calculated values to the control unit85.

The control unit85drives the biaxial rotation stage119and the second slide stage123of the imaging element unit holding portion79based on the image forming surface coordinate value and the XY direction rotation angles input from the adjustment value calculation circuit153, adjusts the Z axis direction position and the inclination of the imaging element unit20, and causes the imaging surface27ato coincide with the approximate image forming surface. The control unit85functions as an adjustment portion which adjusts the Z axis direction position and the inclination of the imaging element unit20with respect to the lens unit10.

The above-described imaging module manufacturing apparatus200schematically performs the following processes.

(1) A process of holding the lens unit10and the imaging element unit20on the Z axis orthogonal to the chart surface of the measurement chart89.

(2) A process of changing the Z axis direction position of the imaging element unit20held on the Z axis, driving the imaging element27via the electric connection portion in a state where electricity flows to each of the first to third lens driving units of the lens unit10held on the Z axis at each position, and imaging the measurement chart89by the imaging element27.

(3) A process of adjusting the position and the inclination of the imaging element unit20with respect to the lens unit10based on the imaging signals obtained by imaging the measurement chart89by the imaging element27, and fixing the imaging element unit20to the lens unit10.

Hereinafter, details of the manufacturing process of the imaging module100performed by the imaging module manufacturing apparatus200will be described with reference to a flowchart ofFIG. 10.

First, holding (S1) of the lens unit10performed by the lens holding mechanism77will be described.

The control unit85controls the first slide stage99so as to move the holding plate114along the Z axis direction, and forms a space, in which the lens unit10can be inserted, into a portion between the lens positioning plate75and the holding plate114. The lens unit10is held by a robot (not shown) and is transferred to the portion between the lens positioning plate75and the holding plate114.

The control unit85detects the movement of the lens unit10using an optical sensor or the like, and moves the stage portion99aof the first slide stage99in the direction approaching the lens positioning plate75. In addition, the concave sections95A,95B, and95C of the lens unit10come into contact with the abutment pins93A,93B, and93C, and the insertion pins93A1and93C1are inserted into the concave sections95C1and95A1.

Accordingly, the lens unit10is positioned in the Z axis direction, the X axis direction, and the Y axis direction. In addition, if the stage portion99amoves in the direction approaching the lens positioning plate75, the lens unit10is interposed between the holding plate114and the lens positioning plate75such that the lens unit10is held.

In the state where the lens unit10is held, the contactor of the probe113aof the probe unit113comes into contact with the terminals14A to14F of the lens unit10, and the first to third lens driving units and the lens driving driver145are electrically connected to each other (S2).

Next, holding (S3) of the imaging element unit20performed by the imaging element unit holding portion79will be described.

The control unit85controls the second slide stage123so as to move the biaxial rotation stage119along the Z axis direction, and forms a space, in which the imaging element unit20can be inserted, into a portion between the lens holding mechanism77and the biaxial rotation stage119. The imaging element unit20is held by a robot (not shown) and is transferred to the portion between the lens holding mechanism77and the biaxial rotation stage119.

The control unit85detects the movement of the imaging element unit20using an optical sensor or the like, and moves the stage portion123aof the second slide stage123in the direction approaching the holding plate114. In addition, a worker holds the imaging element unit20using the holding member115aof the chuck hand115. In addition, the connector cable127is connected to the external connection terminal portion23of the imaging element unit20. Accordingly, the imaging element27and the control unit85are electrically connected to each other. Thereafter, the holding of the imaging element unit20is released by a robot (not shown).

In this way, after the lens unit10and the imaging element unit20are held on the Z axis, the horizontal focusing coordinate value and the vertical focusing coordinate value of each imaging position of the imaging surface27aare acquired by the focusing coordinate value acquisition circuit149(S4).

Specifically, the control unit85controls the second slide stage123so as to move the biaxial rotation stage119in the direction approaching the holding plate114, and moves the imaging element unit20to an initial measurement position at which the imaging element27is closest to the lens unit10.

The control unit85causes the light source91of the chart unit71to emit light. In addition, the control unit85inputs the driving signals from the lens driving driver145to the terminals14A to14F so as to drive the first to third lens driving units, and holds the x direction position, the y direction position, and the z direction position of the optical axis Ax of the lens group12to a reference position (for example, initial position when actually used).

Next, the control unit85controls the imaging element driver147so as to image the chart images CH1, CH2, CH3, CH4, and CH5formed by the lens unit10on the imaging element27. The imaging element27inputs the captured imaging signals to the focusing coordinate value acquisition circuit149via the connector cable127.

The focusing coordinate value acquisition circuit149extracts the signals of the pixel at the imaging position corresponding to each of the chart images CH1, CH2, CH3, CH4, and CH5from the input imaging signals, and calculates the X-CTF value and the Y-CTF value with respect to each imaging position from the pixel signals. For example, the control unit85stores the information of the X-CTF value and the Y-CTF value in the RAM in the control unit85.

The control unit85sequentially moves the imaging element unit20to the plurality of measurement positions (Z0, Z1, Z2, . . . ) set along the Z axis direction, and images the chart image of the measure chart89on the imaging element27at each measurement position in the state where the x direction position, the y direction position, and the z direction position of the optical axis Ax of the lens group12are held to the reference positions. The focusing coordinate value acquisition circuit149calculates the X-CTF value and the Y-CTF value at the imaging position of each measurement position.

The focusing coordinate value acquisition circuit149selects the maximum value among the plurality of calculated X-CTF values and Y-CTF values with respect to each imaging position, and acquires the Z axis coordinate of the measurement position, at which the maximum value is obtained, as the horizontal focusing coordinate value and the vertical focusing coordinate value at the imaging position.

The horizontal focusing coordinate value and the vertical focusing coordinate value acquired by the focusing coordinate value acquisition circuit149are input to the imaging forming surface calculation circuit151. For example, the image forming surface calculation circuit151calculates an approximately planarized approximate image forming surface F using a least square method (S6).

The information of the approximate image forming surface F calculated by the imaging forming surface calculation circuit151is input to the adjustment value calculation circuit153. The adjustment value calculation circuit153calculates the image forming surface coordinate value F1which is the intersection point between the approximate image forming surface F and the Z axis, and the XY direction rotation angles which are the inclinations of the approximate image forming surface with respect to the XY coordinate plane around the X axis and the Y axis, and inputs the calculated value and angles to the control unit85(S7).

The control unit85controls the biaxial rotation stage119and the second slide stage123based on the image forming surface coordinate value F1and the XY direction rotation angles, and moves the imaging element unit20in the Z axis direction such that the center position of the imaging surface27aof the imaging element27is coincident with the image forming surface coordinate value F1. In addition, the control unit85adjusts angles of the imaging element unit20in the θx direction and the θy direction such that the inclination of the imaging surface27ais coincident with the approximate image forming surface F (S8).

The control unit85performs a confirmation process which confirms the focusing position of each imaging position after the position and the inclination of the imaging element unit20are adjusted (S9).

In this confirmation process, each process of the above-described S4is performed again. After the position and the inclination of the imaging element unit20are adjusted, variation of evaluation values corresponding to the horizontal direction and the vertical direction with respect to each of the imaging positions decreases.

After the confirmation process (S9) ends (S5: YES), the control unit85moves the imaging element unit20in the Z axis direction such that the center position of the imaging surface27ais coincident with the image forming surface coordinate value F1(S10).

In addition, the control unit85supplies the ultraviolet curing adhesive from the adhesive supply portion81to the gap between the lens unit10and the imaging element unit20(S11), and cures the ultraviolet curing type adhesive by lighting the ultraviolet lamp83(S12).

After the adhesive is cured and the lens unit10and the imaging element unit20are fixed to each other, the control unit85moves the stage portion99ato the imaging element unit holding portion79side, and contact between the contactor of the probe113aand each of the terminals14A to14F of the lens unit10is released (S13). Thereafter, the completed imaging module100is discharged from the imaging module manufacturing apparatus200by a robot (not shown) (S14).

In addition, the lens unit10and the imaging element unit20are fixed by the ultraviolet curing type adhesive. However, the curing of the ultraviolet curing type adhesive may be used for temporary fixation between the lens unit10and the imaging element unit20.

For example, in a state where the lens unit10and the imaging element unit20are temporarily fixed to each other, the imaging module100is discharged from the imaging module manufacturing apparatus200, a desired process such as cleaning processing is performed, and thereafter, the lens unit10and the imaging element unit20may be completely fixed to each other by a thermosetting type adhesive or the like.

In general, the contactor of the probe for allowing electricity to flow to an electronic circuit or the like is configured of a magnetic material. However, if the contactor of the probe113ais configured of a magnetic material, an attractive force is generated between the magnets162and165inside the lens unit10and the contactor of the probe113a, and the lens barrel15may be held by the manufacturing apparatus200in a state where the optical axis Ax of the lens barrel15is deviated from desired positions in the x direction and the y direction.

In the above-described manufacturing apparatus200, the positioning of the lens unit10and the imaging element unit20is performed in a state where the contactor of the probe113aconfigured of a non-magnetic material comes into contact with the terminals14A to14F of the lens unit10, and electricity flows to the lens drive unit16of the lens unit10.

Accordingly, when the contactor of the probe113acomes into contact with the terminals14A to14F of the lens unit10, an attractive force is not applied to the portion between the contactor of the probe113aand the magnets162and165, and it is possible to prevent the magnets162and165from moving in the x direction and the y direction. Therefore, the optical axis Ax and the Z axis can coincide with each other when the lens unit10is held, and it is possible to perform positioning of the lens unit10and the imaging element unit20with high accuracy.

In a case where magnetic forces of the magnets162and165used in the lens unit10or weight of the lens barrel15used in the lens unit10, volume ratios of all probes113acoming into contact with the lens unit10with respect to the magnets162and165having volumes matching with the probes, a modulus of elasticity of the spring163used in the lens drive unit16, or the like is designed within a range which is generally considered, with respect to the lens unit10in which the minimum distance among distances of straight lines which connect the centers of the terminals14A to14F exposed from the housing11of the lens unit10and the magnets162and165is 1.5 mm or less, deviation of the optical axis Ax of the lens group12increases to an extent in which the deviation is not allowable if the contactor of the probe113ais formed of a magnetic material.

In recent years, since a decrease in size of the lens unit10is required, it is difficult to set the minimum distance to a distance which is larger than 1.5 mm. Accordingly, even when the probe113ais a small, the magnets162and165are attracted by the probe113a, and optical axis Ax may move. Therefore, the contactor of the probe, which is configured of a general magnetic material, is required to be formed of a non-magnetic material, and the configuration of the probe113adescribed in the present embodiment is effective.

In JP2009-210443A, a technology premised on a spring type probe is not described, but a technology premised on a probe using a metal spring wire is described, and a non-magnetic material such as beryllium copper is used as the material of the metal spring wire. In the probe disclosed in JP2009-210443A, the probe is pressed to an electrode, which is an object to be energized, using an elastic force generated by bending the probe having spring properties.

In the manufacturing apparatus200of the present embodiment, if a method of pressing the probe to the terminals14A to14F of the lens unit10using an elastic force generated by bending the probe having spring properties is adopted, the lens unit10may move due to the pressing force of the probe. In order to prevent the lens unit10from moving due to the pressing force of the probe, it is necessary to increase a holding force of the lens unit10, and a cost of the manufacturing apparatus200increases.

In the manufacturing apparatus200, since a spring type probe113ais used, it is possible to decrease a force applied to the lens unit10during probing. Accordingly, it is not necessary to increase the holding force of the lens unit10, and it is possible to prevent the cost of the manufacturing apparatus200from increasing.

Moreover, in a case where the contactor of the probe113ais configured of the main body which is formed of a non-magnetic material and the film which is coated on the surface of the main body and is formed of a material different from that of the main body, even when the material of the coated film includes a magnetic material, a ratio of the volume of the coated film with respect to the volume of the main body is sufficiently small. Accordingly, it is possible to prevent occurrence of the attractive force between the probe113aand the magnet.

Hereinbefore, the manufacturing apparatus for manufacturing the lens unit10having the first to third lens driving units is described. However, even when only the second lens driving unit and the third lens driving unit are mounted on the lens unit10, it is possible to perform positioning with high accuracy by allowing electricity to flow to the lens unit10using the above-described method.

Like the imaging module100, in the case where the first to third lens driving units are mounted on the lens unit10, the number of the terminals used for allowing electricity to flow to the lens drive unit16may be larger than the number of the terminals of the lens unit on which only the second lens driving unit and the third lens driving unit are mounted. That is, since the volume ratio of the probes with respect to the magnets inside the lens unit10increases, adopting the probe113aincluding the contactor formed of a non-magnetic material is particularly effective.

Moreover, hereinbefore, it is possible to perform the positioning with high accuracy by driving the first to third lens driving units included in the lens unit10. However, in order to further increase accuracy, the measurement chart89may be imaged by the imaging element27at each measurement position in a state where electricity also flows to the hall element included in the lens drive unit16.

In the case where electricity also flows to the hall element included in the lens drive unit16, at most 18 probes are necessary. Accordingly, in a case where the probe113ais configured of a magnetic material, the attractive force applied to the portion between the magnet inside the lens unit10and the probe increases. Therefore, adopting the probe113aincluding the contactor formed of a non-magnetic material is particularly effective.

In addition, in the process of S4inFIG. 10, in a state where the lens unit holding portion including the lens positioning plate75and the lens holding mechanism77is movable in the Z axis direction, the measurement positions are changed by moving the lens unit holding portion in the Z axis direction in a state where the position of the imaging element unit holding portion79in the Z axis direction is fixed, or by moving each of the lens unit holding portion and the imaging element unit holding portion79in the Z axis direction, and the focusing coordinate value may be acquired at each measurement position.

Moreover, in a state where the positions of the lens unit holding portion and the imaging element unit holding portion79in the Z axis direction are fixed, the measurement positions are changed by moving the chart unit71in the Z axis direction, and the focusing coordinate value may be acquired. In addition, the measurement positions are changed by changing the positions of the lens unit holding portion, the imaging element unit holding portion79, and the chart unit71in the Z axis direction, and the focusing coordinate value may be acquired.

That is, the measurement positions are changed by changing relative positions of the lens unit10, the imaging element unit20, and the measurement chart89in the Z axis direction, the measurement chart89is imaged by the imaging element27at each relative position, and the focusing coordinate value may be acquired.

Moreover, in the descriptions ofFIG. 10, the plurality of measurement positions are realized by changing the relative positions, and the measurement chart is imaged when the relative position reaches each measurement position. However, the imaging of the measurement chart is continuously performed (that is, motion picture imaging is performed), and the relative position may be changed such that the relative position reaches each measurement position during imaging.

Moreover, in the process of S8inFIG. 10, the position of the imaging element unit20in the Z axis direction with respect to the lens unit10is adjusted by moving the imaging element unit20in a state where the position of the lens unit10in the Z axis direction is fixed. As a modification example with respect to this, in a state where the lens unit holding portion is movable in the Z axis direction, the positional adjustment may be performed by moving the lens unit holding portion in a state where the position of the imaging element unit holding portion79is fixed or by moving each of the lens unit holding portion and the imaging element unit holding portion79.

Moreover, in the process of S8inFIG. 10, the position and the inclination in the Z axis direction of the imaging element unit20with respect to the lens unit10are adjusted. However, the adjustment of the position in the Z axis direction may be omitted. For example, if the lens barrel15in the lens unit10has a screw structure so as to be slidable in the optical axis Ax direction, the adjustment of the position of the manufacturing apparatus200in the Z axis direction may be not performed.

In this way, in the manufacturing apparatus in which the process of adjusting at least the inclination of the imaging element unit20with respect to the lens unit10is performed, it is possible to perform positioning with high accuracy by using the probe113awhich is formed of a non-magnetic material as described above.

Moreover, in the process of S8inFIG. 10, if the position and the inclination in the Z axis direction of the imaging element unit20with respect to the lens unit10are adjusted, at least three chart images may be provided on the chart surface of the measurement chart89.

As described above, in the case where four or more chart images are used, it is possible to perform the inclination adjustment of the imaging element unit20with respect to the lens unit10with higher accuracy.

In a case where electricity flows to the lens unit10, the lens driving units which are objects to be energized need not be all of the first to third lens driving units, and electricity may flow to only the necessary lens driving unit according to the positioning accuracy.

FIG. 11is a view showing a modification example of the manufacturing apparatus200shown inFIG. 5.

A manufacturing apparatus200A shown inFIG. 11is the same as the manufacturing apparatus200shown inFIG. 5except that the electric connection between the imaging element27of the imaging element unit20and the imaging element drive147is performed not using the external connection terminal portion23of the imaging element unit20but using the probe27b.

In the imaging element unit20which is held to the imaging element unit holding portion79by the manufacturing apparatus200A, the plurality of electric connection portions such as the data output terminal and the drive terminal of the imaging element27which are electrically connected to the imaging element27are exposed from the rear surface of the substrate21.

The plurality of probes27bare provided in the biaxial rotation stage119, and each of the plurality of probes27bis electrically connected to the imaging element driver147.

In a state where a worker holds the imaging element unit20to the apparatus using the holding members115aof the chuck hand115, any one of the plurality of probes27bis pressed to each terminal exposed from the rear surface of the substrate21of the imaging element27, and the imaging element27and the imaging element driver147are electrically connected to each other. In the manufacturing apparatus200A ofFIG. 11, the probe unit113functions as the first probe pressing portion, and the biaxial rotation stage119functions as the second probe pressing portion.

In the manufacturing apparatus200A, each of the plurality of probes27bhas the same configuration as that of the probe113a. Accordingly, even in a state where the imaging element unit20held by the imaging element unit holding portion79approaches the position closest to the lens unit10, the magnet inside the lens unit10is not attracted to the plurality of probes27b. Accordingly, it is possible to maintain the position of the lens group12of the lens unit10in a desired state, and it is possible to perform the positioning of the lens unit10and the imaging element unit20with high accuracy.

In the manufacturing apparatuses shown inFIGS. 5 and 11, the lens unit10is held on the Z axis by allowing the concave sections95A,95B, and95C of the lens unit10to come into contact with the abutment pins93A,93B, and93C of the lens positioning plate75and pressing the lens unit10to the lens positioning plate75side by the holding plate114.

As a modification example with respect to this, using an external setup tool shown inFIG. 12, the lens unit10may be held on the Z axis by attaching the external setup tool to a plate disposed on the Z axis.

FIG. 12is an external perspective view of the external setup tool.

A tool750(first tool) shown inFIG. 12comprises a substrate75A, and a convex section75B which is formed on a substrate75A.

An opening75C is provided on the substrate75A. Eight protrusions75D are formed around the opening75C of the substrate75A. The eight protrusions75D position the top surface11aof the housing11of the lens unit10.

A partial concave section is formed on the convex section75B, and a rotatable pedestal75F is formed on the concave section.

A lens unit pressing portion75E for pressing the lens unit10disposed within a range defined by eight protrusions75D of the substrate75A is formed on the pedestal75F.

If a worker rotates the pedestal75F to the left and the lens unit pressing portion75E is rotated left at 90° from the state ofFIG. 12, a space is generated on the upper portion of the range defined by the eight protrusions75D of the substrate75A. In this state, the worker disposes the top surface11aof the housing11of the lens unit10in the range defined by the eight protrusions75D. In addition, if the worker rotates the pedestal75F to the right and the lens unit pressing portion75E is brought into the state ofFIG. 12, the lens unit pressing portion75E presses the lens unit10to the substrate75A side, and the lens unit10is held by the tool750.

In the manufacturing apparatuses200and200A, a plate (second tool) capable of attaching and detaching the tool750is disposed at a position at which the lens positioning plate75is to be disposed on the Z axis. In addition, the lens unit10is held on the Z axis by attaching the tool750to the plate using a robot. In this state, by moving the stage portion99aand allowing the probe113ato come into contact with each terminal of the lens unit10, electricity can flow to the lens drive unit16of the lens unit10.

In the tool750, by forming all materials (a material of the substrate75A, a material of the convex section75B, a material of the protrusion75D, a material of the pedestal75F, and a material of the lens unit pressing portion75E) configuring the tool750in non-magnetic materials, it is possible to prevent deviation in the position of the optical axis Ax due to using of the tool750. As the non-magnetic materials used in the tool750, austenitic stainless steel, aluminum, copper, copper alloy, brass, or the like may be used.

Moreover, in the tool750, a surface treatment such as plating may be performed on all components configuring the tool750. That is, the tool750may be configured of a main body formed of a non-magnetic material, and a film which is coated on the surface of the main body and is formed of a material different from that of the main body.

In a case where a stainless steel base material is used as the non-magnetic material, a Raydent treatment or a Raydent H treatment may be performed. In a case where an aluminum base material is used as the non-magnetic material, a black alumite treatment or a hard black alumite treatment may be performed.

By performing the surface treatment on the tool750, it is possible to improve durability of the tool. In addition, it is possible to prevent reflection of light on the surface of the tool750, occurrence of ghost, flare, or the like on a captured image is prevented, and it is possible to improve the positioning accuracy of the lens unit10and the imaging element unit20.

In this way, according to the configuration of the apparatus in which the lens unit10is held on the Z axis using the tool750, when a different imaging module is manufactured by the manufacturing apparatus, the lens unit10of the next product can be prepared. Accordingly, it is possible to increase the manufacturing efficiency of the imaging module.

As described above, the present specification describes the following matters.

In a disclosed manufacturing method of an imaging module having a lens unit which has a lens group, and an imaging element unit which is fixed to the lens unit and has an imaging element which images a subject through the lens group, in which the lens unit has a lens drive unit which includes two lens driving units which respectively move at least a portion of lenses of the lens group in two directions orthogonal to an optical axis of the lens group, a housing which accommodates the lens group and the lens drive unit, and an electric connection portion which is exposed from the housing and is electrically connected to the lens drive unit, the two lens driving units have voice coils and magnets facing the voice coils, and the manufacturing method comprises: a first process of, on an axis orthogonal to a measurement chart, changing relative positions of at least one or more of the imaging element unit, the lens unit, and the measurement chart in the direction of the axis, and driving the imaging element and imaging the measurement chart through the lens group by the imaging element at each relative position; and a second process of adjusting at least an inclination of the imaging element unit with respect to the lens unit based on imaging signals obtained by imaging the measurement chart by the imaging element, and fixing the imaging element unit to the lens unit, and in the first process, the lens unit is held on the axis, and the measurement chart is imaged by the imaging element in a state where a contactor of a first probe having the contactor including a main body formed of a non-magnetic material is pressed to the electric connection portion of the lens unit and electricity flows to the lens drive unit.

In the disclosed manufacturing method of an imaging module, the first probe comprises the contactor, and an elastic body which biases the contactor.

In the disclosed manufacturing method of an imaging module, the non-magnetic material is a non-magnetic metal.

In the disclosed manufacturing method of an imaging module, the contactor is configured of the main body, and a film which is coated on a surface of the main body and is formed of a material different from a material of the main body.

In the disclosed manufacturing method of an imaging module, the shortest distance among distances between the electric connection portion and the magnets in the lens unit is 1.5 mm or less.

In the disclosed manufacturing method of an imaging module, in the first process, the imaging element unit is held on the axis, and the measurement chart is imaged by the imaging element in a state where a contactor of a second probe having the contactor including a main body formed of a non-magnetic material is pressed to an electric connection portion which is provided in the imaging element unit and is electrically connected to the imaging element, and electricity flows to the imaging element.

In the disclosed manufacturing method of an imaging module, in the first process, the lens unit is held on the axis by disposing a tool formed of a non-magnetic material, to which the lens unit is attached, on the axis.

In the disclosed manufacturing method of an imaging module, the tool is configured of a main body formed of a non-magnetic material, and a film which is coated on a surface of the main body and is formed of a material different from that of the main body.

A disclosed imaging module manufacturing apparatus, comprises: a measurement chart installation portion for installing a measurement chart; an imaging element unit holding portion for holding an imaging element unit having an imaging element which images a subject through a lens unit having a lens group, on an axis orthogonal to the measurement chart installed on the measurement chart installation portion; a lens unit holding portion for holding the lens unit on the axis between the measurement chart installation portion and the imaging element unit holding portion; a first probe pressing portion which presses a contactor of a first probe having the contactor including a main body formed of a non-magnetic material to the lens unit held by the lens unit holding portion; a control unit which changes relative positions of at least one or more of the measurement chart installation portion, the lens unit holding portion, and the imaging element unit holding portion in the direction of the axis, and drives the imaging element of the imaging element unit and images the measurement chart through the lens unit by the imaging element at each relative position; an adjustment portion which adjusts at least an inclination of the imaging element unit with respect to the lens unit based on imaging signals obtained by imaging the measurement chart by the imaging element; and a unit fixing portion which fixes the imaging element unit adjusted by the adjustment portion to the lens unit.

In the disclosed imaging module manufacturing apparatus, the first probe comprises the contactor, and an elastic body which biases the contactor.

In the disclosed imaging module manufacturing apparatus, the non-magnetic material is a non-magnetic metal.

In the disclosed imaging module manufacturing apparatus, the contactor is configured of the main body, and a film which is coated on a surface of the main body and is formed of a material different from a material of the main body.

In the disclosed imaging module manufacturing apparatus, the first probe pressing portion presses the contactor of the first probe to an electric connection portion which is included in the lens unit held by the lens unit holding portion, is electrically connected to a lens drive unit including a voice coil and a magnet which configure two lens driving units respectively moving at least a portion of lenses of the lens group in two directions orthogonal to an optical axis of the lens group, and is exposed from a housing which accommodates the lens group and the lens drive unit, and the imaging module manufacturing apparatus further comprises a second probe pressing portion which presses a contactor of a second probe having the contactor including a main body formed of a non-magnetic material to an electric connection portion which is provided in the imaging element unit held by the imaging element unit holding portion and is electrically connected to the imaging element.

In the disclosed imaging module manufacturing apparatus, the lens unit holding portion comprises a second tool which is configured to attach and detach a first tool formed of a non-magnetic material for attaching the lens unit, and is disposed on the axis.

In the disclosed imaging module manufacturing apparatus, the first tool is configured of a main body formed of a non-magnetic material, and a film which is coated on a surface of the main body and is formed of a material different from a material of the main body.

INDUSTRIAL APPLICABILITY

A manufacturing method of an imaging module and an imaging module manufacturing apparatus of the present invention are particularly effectively applied to manufacturing of an imaging module which is mounted on an electric device such as a portable phone, a spectacle type electronic device, or a wrist watch type electronic device.

Hereinbefore, the present invention is described according to specific embodiments. However, the present invention is not limited to the embodiments, and various modifications may be applied within a scope which does not depart from a technical idea of the disclosed invention.