JP5558181B2 - Camera module and electronic device including the same - Google Patents

Description

  The present invention relates to a camera module mounted on an electronic device such as a mobile phone and an electronic device including the camera module. More specifically, the present invention relates to a camera module that can prevent foreign objects from entering the optical path and reduce imaging defects, and an electronic device including the camera module.

  In recent years, camera modules that exhibit an autofocus function using a lens driving device are being installed in many electronic devices such as mobile phones. There are various types of lens driving devices such as a type using a stepping motor, a type using a piezoelectric element, and a VCM (Voice Coil Motor) type, which are already on the market.

  For example, Patent Document 1 discloses a camera module equipped with a lens driving device. FIG. 6 is a cross-sectional view of the camera module 200 of Patent Document 1.

  The camera module 200 includes a lens unit 201a and an imaging unit 202. The lens unit 201a is a lens driving device for exhibiting an autofocus function. In the camera module 200, openings (a light incident side opening 219a and a light emitting side opening 211a) are formed at both ends in the optical axis direction. For this reason, foreign matter may enter the lens unit 201a from the outside through the opening 219a on the light incident side. Further, foreign matter may be generated from within the lens unit 201a. Furthermore, there is a possibility that such a foreign substance goes out from the opening 211a on the light emission side. If such a foreign substance enters the optical path, it may cause an imaging failure (image failure) such as a stain failure. Blemish defect is a phenomenon in which foreign matter appears as a black shadow in an image.

  Therefore, in the camera module 200, a protrusion 214a is formed on the lens holder 214 as a countermeasure against such foreign matter. Specifically, a protrusion 214 a is formed on the bottom of the lens holder 214, and this protrusion 214 a surrounds the entire periphery of the opening 211 a formed on the base 211. Thereby, the protrusion 214a blocks foreign matter from entering the optical path from the opening 211a. Therefore, it is possible to reduce imaging defects.

  As described above, the camera module 200 reduces the intrusion of the foreign matter by blocking the foreign matter intrusion path by the protrusion 214a provided on the lens unit 201a.

JP 2009-251517 A (released on October 29, 2009)

  However, in the configuration of Patent Document 1, imaging countermeasures still occur because measures for preventing foreign substances from entering the optical path are insufficient.

  Specifically, FIG. 7 is a cross-sectional view showing a foreign substance intrusion path in the camera module 200 of Patent Document 1, wherein (a) shows a lens unit 201a at a stationary position in the camera module 200, and (b) is a camera. It is a figure which shows the lens unit 201a of the highest position in the module 200. FIG.

  When the camera module 200 is manufactured or used, foreign matter that may enter the optical path includes foreign matter entering from the opening 219a formed in the cover 219, foreign matter existing in the lens unit 201a, and the lens unit 201a. Foreign matter generated by peeling off. As shown by the arrows in FIG. 7A, such foreign matters are a gap in the pattern of the leaf spring 215a, a gap between the lens holder 214 and the yoke 217, and a gap between the coil 216 and the yoke 217 or the permanent magnet 218. Etc. and reach the base 211.

  As shown in FIG. 7A, when the lens unit 201 a is in the steady position, the protrusion 214 a formed on the bottom of the lens holder 214 is in contact with the base 211. For this reason, entry of foreign matter into the optical path from the opening 211a is blocked. Accordingly, the foreign matter that has reached the base 211 does not enter the optical path.

  However, as shown in FIG. 7B, when the lens unit 201a is driven, the lens holder 214 is raised, so that a gap is formed between the base 211 and the protrusion 214a. This gap becomes maximum when the lens unit 201a is at the highest position, for example, when the macro mode is executed. As a result, as shown by the arrow in FIG. 7B, the foreign matter that has reached the base 211 passes through the gap in the pattern of the leaf spring 215b and the gap between the base 211 and the protrusion 214a, and the optical path. Invades inside.

  The lens unit 201a has a complicated structure in which the lens holder 214, the coil 216, and the yoke 217 are complicated. For this reason, it is difficult to remove in advance foreign substances present in the lens unit 201a. Further, a dust trap agent 220 is applied as an adhesive material in the groove 211b formed on the surface of the base 211. As a result, a part of the foreign matter that has moved onto the base 211 is captured by the dust trapping agent 220, but not all of the foreign matter can be captured.

  Thus, in the lens unit 201a, there is a path through which foreign matter enters the optical path, and the possibility that foreign matter is present is extremely high. Therefore, the camera module 200 still has imaging defects.

  Therefore, the present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a camera module that can prevent foreign matter from entering the optical path and reduce imaging defects, and the camera module. To provide electronic equipment.

In order to solve the above problems, the camera module of the present invention includes an optical unit having an imaging lens and a lens holding unit that holds the imaging lens, a lens driving unit that drives the optical unit in the optical axis direction, and A camera module including an image pickup unit having an image pickup element that converts light incident through the image pickup lens into an electric signal and a substrate on which the image pickup element is mounted, wherein a recess is formed on the substrate. At least a part of the lens driving unit is provided in the recess, and the lens driving unit includes a coil and a magnet that drive the optical unit in the optical axis direction by electromagnetic force, and the coil A coil holder for holding and a motor holder for holding the magnet so as to face the coil, and the coil holder and the motor holder are provided independently of each other. At least a portion of the coil and magnet, is characterized in that provided in the recess of the substrate.

According to said structure, at least one part of the lens drive part is provided in the recessed part formed in the board | substrate with which the image pick-up element was mounted. As a result, the foreign matter moved along the lens driving unit reaches the recess. That is, foreign matter accumulates below the image sensor. For this reason, in order for the foreign matter accumulated in the concave portion to enter the optical path, the foreign matter must move from a position lower than the image sensor to a position higher than the image sensor. In other words, the movement path of the foreign matter is remarkably longer than that of the camera module 200 of Patent Document 1, so that it is very difficult for the foreign matter to enter the optical path. As a result, it is possible to reliably prevent foreign matter from entering the optical path. Accordingly, it is possible to reduce imaging defects due to foreign matters. Therefore, a highly reliable camera module can be realized.
Moreover, according to said structure, the coil holder holding a coil and the motor holder holding a magnet are provided mutually independently. Thereby, even if the foreign substance exists in the lens driving unit, the foreign substance can be easily removed in advance when the camera module is manufactured. For this reason, it is possible to reduce foreign substances present in the lens driving unit. Therefore, imaging defects can be reduced more reliably.
Further, according to the above configuration, at least a part of the coil and at least a part of the magnet are both provided in the recess of the substrate. Thereby, a lens drive part can be formed on an image pick-up part only by inserting a coil held at a coil holder and a magnet held at a motor holder into a recess. Therefore, the camera module can be easily manufactured.

  In the camera module of the present invention, it is preferable that a translucent member disposed to face the imaging element is provided between the imaging lens and the imaging element.

  According to said structure, the translucent member is arrange | positioned facing the image pick-up element on the optical path. For this reason, even if the foreign substance in a recessed part moves, the movement of the foreign substance to an image pick-up element is interrupted | blocked by a translucent member. Accordingly, it is possible to reliably prevent foreign matter from adhering to the light receiving portion of the image sensor.

  In the camera module of the present invention, it is preferable that the coil holder further holds the optical unit inside.

  According to said structure, the coil and the optical part are hold | maintained at the same member (coil holder). Accordingly, since the structure of the camera module (particularly the structure of the coil holder) is simplified, the camera module can be downsized in the lateral direction (width direction).

  In the camera module of the present invention, the camera module includes a sensor cover that holds the light-transmissive member and accommodates the imaging element therein, and at least a part of the outer surface of the sensor cover is more than the inner surface of the recess It is preferable to be disposed near the image sensor.

  According to said structure, the outer surface of a sensor cover has the part arrange | positioned at the image pick-up element side rather than the inner surface of a recessed part. For this reason, even if the foreign matter staying in the recess moves along the inner surface of the recess as the lens driving unit is driven, the foreign matter is arranged closer to the image sensor than the inner surface of the recess. It stays in the part. That is, a foreign object can be captured at that portion. As a result, it is possible to more reliably prevent foreign matter from entering the optical path. Therefore, imaging defects can be further reduced.

  In the camera module of the present invention, it is preferable that an adhesive material is applied in the concave portion of the substrate.

  According to said structure, since the adhesive material is apply | coated in the recessed part of a board | substrate, the foreign material which moved in the recessed part is capture | acquired by the adhesive material. For this reason, the foreign material that has moved into the recess is reliably retained in the recess. As a result, it is possible to more reliably prevent foreign matter from entering the optical path. Therefore, imaging defects can be further reduced.

  In the camera module of the present invention, it is preferable that an adhesive material is applied to the outer surface of the sensor cover.

  According to said structure, since the adhesive material is apply | coated to the outer surface of a sensor cover, the foreign material which moved to the outer surface of a sensor cover is capture | acquired by the adhesive material. For this reason, the foreign material that has moved to the outer surface of the sensor cover stays reliably on the outer surface. As a result, it is possible to more reliably prevent foreign matter from entering the optical path. Therefore, imaging defects can be further reduced.

  In the camera module of the present invention, the substrate may be a ceramic substrate.

  According to the above configuration, since the substrate is made of a ceramic substrate, dust is not easily generated even when the recess and the lens driving unit provided in the recess are rubbed when the optical unit is driven. Therefore, foreign matter generated when the camera module is used can be reduced. Furthermore, since the ceramic substrate can be easily processed, the concave portions can be formed on the substrate with high accuracy. Therefore, the lens driving unit can be mounted in the recess with high accuracy.

  In order to solve the above-described problem, an electronic apparatus according to the present invention includes any one of the camera modules. Therefore, it is possible to provide an electronic device that can prevent foreign matter from entering the optical path and reduce imaging defects.

As described above, the camera module and the electronic device of the present invention have the recess formed on the substrate, and at least a part of the lens driving unit is provided in the recess, and the lens driving unit A coil holder for driving the optical unit in the optical axis direction by force and a magnet; a coil holder for holding the coil; and a motor holder for holding the magnet so as to face the coil. The holder and the motor holder are provided independently of each other, and at least a part of the coil and the magnet are provided in the recess of the substrate . Therefore, it is possible to reduce imaging defects due to foreign matter, and to achieve a highly reliable camera module.

It is a perspective view of the camera module of the present invention. It is AA arrow sectional drawing of the camera module of FIG. It is sectional drawing which shows the penetration | invasion path | route of the foreign material in the camera module of FIG. (A)-(e) is sectional drawing which shows the manufacturing process of the camera module of FIG. It is sectional drawing which shows another camera module of this invention. It is sectional drawing of the camera module of patent document 1. FIG. It is sectional drawing which shows the penetration | invasion path | route of the foreign material in the camera module of patent document 1, (a) shows the lens unit of the steady position in a camera module, (b) is a figure which shows the lens unit of the highest position in a camera module. .

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a camera module 10 according to an embodiment of the present invention. The camera module 10 includes an optical unit 1, a lens driving unit 2, and an imaging unit 3. The optical unit 1 is held inside the lens driving unit 2. The lens driving unit 2 is provided on the imaging unit 3. Hereinafter, the configuration of each part of the camera module 10 will be described in detail with reference to FIG. 2 is a cross-sectional view taken along the line AA of the camera module 10 of FIG. In the following description, for the sake of convenience, the optical unit 1 side is defined as the upper side, and the imaging unit 3 side is defined as the lower side.

(Optical part 1)
The optical unit 1 is an imaging optical system that forms a subject image in the camera module 10. The optical unit 1 includes a plurality (three in FIG. 2) of imaging lenses 11 and a lens barrel (lens holding unit) 12 that holds the imaging lens 11 inside. The lens barrel 12 is held by the lens driving unit 2. The optical axis of the imaging lens 11 coincides with the axis of the lens barrel 12. The optical unit 1 guides external light to the imaging unit 3 by the imaging lens 11.

(Lens drive unit 2)
The lens driving unit 2 drives the optical unit 1 in the optical axis direction. Specifically, in the camera module 10, the lens driving unit 2 moves the imaging lens 11 up and down in the optical axis direction by electromagnetic force. That is, the camera module 10 exhibits an autofocus function by the VCM type lens driving unit 2.

  Specifically, the lens driving unit 2 includes a lens holder (coil holder) 21, a coil 22, a permanent magnet (magnet) 23, a motor holder 24, an upper leaf spring 25a, and a lower leaf spring 25b.

  The lens holder 21 holds the optical unit 1 inside. That is, the lens holder 21 holds the lens barrel 12 holding the imaging lens 11 inside. The lens barrel 12 and the lens holder 21 are both hollow (cylindrical) members. In the camera module 10, the outer surface of the lens barrel 12 and the inner surface of the lens holder 21 are not threaded and are flat. However, as long as the optical unit 1 is slidable in the optical axis direction, it is not limited to being flat, and a screw thread may be formed.

  The inner diameter of the lens holder 21 is slightly larger than the outer diameter of the lens barrel 12, and the lens barrel 12 is attached to the center of the lens holder 21. The axis of the lens holder 21 coincides with the optical axis of the imaging lens 11 and the axis of the lens barrel.

  The coil 22 is fixed to the outer periphery of the lower end (bottom) of the lens holder 21. That is, in this embodiment, the lens holder 21 plays not only a normal role for holding the optical unit 1 but also a role as a coil holder for holding the coil 22.

  The permanent magnet 23 is disposed so as to face the coil 22 and constitutes a magnetic circuit. The permanent magnet 23 is fixed to the bottom of the motor holder 24 independent of the lens holder 21 that holds the coil 22.

  The motor holder 24 accommodates the optical unit 1 and the lens holder 21 inside. An opening 24 a is formed on the upper surface of the motor holder 24 in order to ensure an optical path to the imaging lens 11 (optical unit 1). A permanent magnet 23 is fixed to the bottom of the motor holder 24. In the present embodiment, the permanent magnet 23 is provided on the motor holder 24, but may be provided on the substrate 32 side.

  As described above, the lens driving unit 2 includes the coil 22 and the permanent magnet 23 in order to drive the optical unit 1 (the imaging lens 11) in the optical axis direction by electromagnetic force. Thereby, an electromagnetic force is generated by passing a current from a power source (not shown) through the coil 22 in the magnetic field formed by the permanent magnet 23. As a result, the lens holder 21 moves up and down in the optical axis direction by the generated electromagnetic force. For this reason, it is possible to indirectly move the lens barrel 12 fixed to the lens holder 21 and simultaneously drive the imaging lens 11 in the optical axis direction.

  In the camera module 10, an upper leaf spring 25 a and a lower leaf spring 25 b are provided on the upper and lower surfaces (top surface and bottom surface) of the lens holder 21. The upper leaf spring 25a and the lower leaf spring 25b press the lens holder 21 in the optical axis direction. That is, the upper leaf spring 25a and the lower leaf spring 25b support the lens holder 21 movably in the optical axis direction by an elastic force. The upper leaf spring 25a and the lower leaf spring 25b have a spiral pattern.

  When the imaging lens 11 is driven, the lens holder 21 and the coil 22 fixed to the lens holder 21 move in the optical axis direction, whereas the permanent magnet 23 and the motor holder 24 that holds the permanent magnet 23 do not move. That is, the lens holder 21 and the coil 22 are movable parts, and the permanent magnet 23 and the motor holder 24 are fixed parts. In the lens driving unit 2, the movable part is provided in the fixed part.

(Imaging unit 3)
The imaging unit 3 converts the subject image formed by the optical unit 1 into an electrical signal. That is, the imaging unit 3 is a sensor device that photoelectrically converts light that has passed through the optical unit 1. The imaging unit 3 includes an imaging element 31, a substrate 32, a sensor cover 33, and a translucent member 34. The image sensor 31 and the sensor cover 33 are mounted on the substrate 32, and the image sensor 31 is accommodated inside the sensor cover 33. The translucent member 34 is held by the sensor cover 33 so as to face the imaging element 31.

  More specifically, the image sensor 31 converts the subject image formed by the optical unit 1 into an electrical signal. That is, the image sensor 31 is a sensor chip that converts an optical signal received through the imaging lens 11 of the optical unit 1 into an electrical signal. The image sensor 31 is, for example, a CCD or a CMOS sensor IC. On the surface (upper surface) of the image sensor 31, a light receiving portion (not shown) in which a plurality of pixels are arranged in a matrix is formed. This light receiving portion is a region that forms an image of light incident from the optical portion 1, and is also referred to as a pixel area.

  The image sensor 31 converts the subject image formed on the light receiving unit (pixel area) into an electric signal and outputs the signal as an analog image signal. That is, photoelectric conversion is performed in this light receiving unit. The operation of the image sensor 31 is controlled by a DSP (not shown), and the image signal generated by the image sensor 31 is processed by the DSP.

  The substrate 32 is a wiring substrate having a patterned wiring (not shown). By this wiring, the substrate 32 and the image sensor 31 are electrically connected to each other. The substrate 32 can be composed of, for example, a printed substrate or a ceramic substrate, but is preferably a ceramic substrate.

  The substrate 32 has a recess 32 a formed on the mounting surface of the image sensor 31. The recess 32 a is a groove formed in the entire periphery of the image sensor 31. For this reason, the bottom of the recess 32 a is arranged at a position lower than the image sensor 31. At least a part of the lens driving unit 2 is provided in the recess 32a. The shape (depth, width, size) of the recess 32a may be set arbitrarily and is not particularly limited. In the camera module 10, the bottom of the lens holder 21, the coil 22, the permanent magnet 23, and the lower leaf spring 25b are provided in the recess 32a. And these are the shapes which fit in the recessed part 32a.

  The sensor cover 33 is disposed between the image sensor 31 and the recess 32a formed in the substrate 32, and accommodates the image sensor 31 therein. Since the sensor cover 33 has a hollow shape, an optical path is secured.

  The translucent member 34 is held inside the sensor cover 33 so as to be disposed between the imaging lens 11 and the imaging element 31. The translucent member 34 is disposed to face the image sensor 31 and covers the light receiving portion of the image sensor 31. The translucent member 34 may be made of any material as long as it has a property of transmitting light to be received by the image sensor 31. For example, the translucent member 34 can be composed of glass (glass substrate) or the like. In the present embodiment, an infrared blocking film (IR cut film) is formed on the surface of the translucent member 34 in order to block infrared rays that are not necessary for imaging. For this reason, the translucent member 34 also has a function of blocking infrared rays.

  The translucent member 34 may be attached to the sensor cover 33 or may be fixed on the image sensor 31 via an adhesive. In the camera module 10, the translucent member 34 is attached to the sensor cover 33 so as to be separated from the image sensor 31. As described above, it is preferable that the translucent member 34 be separated from the image sensor 31 because the influence degree of the foreign matter adhering to the translucent member 34 (reflection on the image sensor) is reduced.

  Thus, in the imaging unit 3, the optical signal incident on the imaging element 31 is photoelectrically converted. Then, the converted electrical signal passes through the substrate 32 and is input to a control circuit or the like of the camera module 10 (not shown) and is taken out as an image signal.

(Features and effects of camera module 10)
Next, feature points of the camera module 10 will be described in comparison with the camera module 200 of Patent Document 1. FIG. 3 is a cross-sectional view showing a foreign substance intrusion path in the camera module 10 of FIG. On the other hand, FIG. 7 is a cross-sectional view showing a foreign substance intrusion path in the camera module 200 of Patent Document 1, wherein (a) shows a lens unit 201a at a steady position in the camera module 200, and (b) in the camera module 200. It is a figure which shows the lens unit 201a of the highest position.

  When the camera module 200 is manufactured or used, foreign matter that may enter the optical path includes foreign matter entering from the opening 219a formed in the cover 219, foreign matter existing in the lens unit 201a, and the lens unit 201a. Foreign matter generated by peeling off. As shown by the arrows in FIG. 7A, such foreign matters are a gap in the pattern of the leaf spring 215a, a gap between the lens holder 214 and the yoke 217, and a gap between the coil 216 and the yoke 217 or the permanent magnet 218. Etc. and reach the base 211.

  As shown in FIG. 7A, when the lens unit 201 a is in the steady position, the protrusion 214 a formed on the bottom of the lens holder 214 is in contact with the base 211. For this reason, entry of foreign matter into the optical path from the opening 211a is blocked. Accordingly, the foreign matter that has reached the base 211 does not enter the optical path.

  However, as shown in FIG. 7B, when the lens unit 201a is driven, the lens holder 214 is raised, so that a gap is formed between the base 211 and the protrusion 214a. This gap becomes maximum when the lens unit 201a is at the highest position, for example, when the macro mode is executed. As a result, as shown by the arrow in FIG. 7B, the foreign matter that has reached the base 211 passes through the gap in the pattern of the leaf spring 215b and the gap between the base 211 and the protrusion 214a, and the optical path. Invades inside.

  As described above, in the camera module 200 of Patent Document 1, there is a path through which the foreign matter enters the optical path in the lens unit 201a. Therefore, the camera module 200 still has imaging defects.

  Therefore, the greatest feature of the present invention is that a countermeasure against foreign matter intrusion is provided below the image sensor. That is, in the camera module 10, at least a part of the lens driving unit 2 is provided in the recess 32 a formed in the substrate 32 as a countermeasure against such foreign matter intrusion. Specifically, in the camera module 10, the coil 22 and the bottom of the lens holder 21 that holds the coil 22, the permanent magnet 23, and the lower leaf spring 25 b are provided in the recess 32 a.

  In such a camera module 10, as shown by an arrow in FIG. 3, foreign matter enters the lens driving unit 2 from the opening 24 a of the motor holder 24 through the pattern gap of the upper leaf spring 25 a. Furthermore, the foreign matter that has entered moves along the outer surface of the lens holder 21 and reaches the recess 32a. That is, the foreign matter reaches below the image sensor 31. For this reason, in order for the foreign matter accumulated in the recess 32a to enter the optical path, the foreign matter must move from a position lower than the image sensor 31 to a position higher than the image sensor 31 and the translucent member 34. I must. In other words, the movement path of the foreign matter is remarkably longer than that of the camera module 200 of Patent Document 1, so that it is very difficult for the foreign matter to enter the optical path. As a result, it is possible to reliably prevent foreign matter from entering the optical path. Accordingly, it is possible to reduce imaging defects due to foreign matters. Therefore, a highly reliable camera module 10 can be realized.

  Even if foreign matter is present in the lens driving unit 2 of the camera module 10, the foreign matter moves along the same movement path. Accordingly, it is possible to reduce imaging defects due to foreign matters.

  Further, the camera module 10 drives the optical unit 1 in the optical axis direction by electromagnetic force. Therefore, in the camera module 10 including the VCM type lens driving unit 2, it is possible to reduce imaging defects.

  On the other hand, the camera module 200 of Patent Document 1 is intended to prevent movement of foreign matter on the base 211 by complicating the shape inside the lens unit 201a. That is, the countermeasure against foreign matter intrusion is applied to the lens unit 201 a disposed at a position higher than the light-transmitting member 223 than the image sensor 222. For this reason, when a foreign substance enters the optical path from the opening 211a, it easily adheres to the translucent member 223. As a result, the attached foreign matter is reflected as a black shadow in the image, and a stain defect occurs.

  On the other hand, the camera module 10 of the present embodiment is intended to prevent foreign matter from entering the optical path by retaining the foreign matter in the recess 32 a formed in the substrate 32. In other words, the foreign matter intrusion countermeasure is applied to the substrate 32 disposed at a position lower than the light-transmitting member 34 than the image sensor 31. For this reason, if the foreign matter staying in the recess 32 a does not move to the upper part of the sensor cover 33, the foreign matter does not adhere to the translucent member 34. That is, the foreign matter does not easily adhere to the translucent member 34. Therefore, it is possible to reduce the occurrence of spot defects, particularly among imaging defects.

  In addition, in the camera module 10, the inner surface of the recess 32 a (the inner wall surface on the image sensor 31 side) and the outer surface of the sensor cover 33 are flush with each other. Thereby, even if the foreign matter staying in the concave portion 32a moves with the movement of the lens holder 21 (drive of the optical unit 1), the outer surface of the sensor cover 33 becomes a wall. For this reason, it is difficult for foreign matter to enter the optical path, and it is particularly difficult for foreign matter to adhere to the translucent member 34. Accordingly, it is possible to more reliably reduce the occurrence of spot defects.

  On the other hand, in the camera module 200 of Patent Document 1, the lens unit 201a has a configuration in which the respective members are integrated. Moreover, the internal structure of the lens unit 201a has a complicated shape in which the lens holder 214, the coil 216, and the yoke 217 are complicated. For this reason, it is difficult to remove in advance foreign substances present in the lens unit 201a. That is why the dust trap agent 220 is applied as an adhesive in the groove 211 formed on the surface of the base 211. As a result, a part of the foreign matter that has moved onto the base 211 is captured by the dust trapping agent 220, but not all of the foreign matter can be captured. Therefore, there is a high possibility that the lens unit 201a contains foreign matter. Therefore, imaging defects are likely to occur.

  On the other hand, in the camera module 10 of the present embodiment, the lens holder 21 that holds the coil 22 and the motor holder 24 that holds the permanent magnet 23 are provided independently of each other. That is, in the lens driving unit 2, the lens holder 21 and the motor holder 24 are not integrated. The lens driving unit 2 has a simple structure in which a lens holder 21 and a motor holder 24 are doubled. Thereby, even if a foreign substance is present in the lens driving unit 2, the existing foreign substance can be easily removed in advance. For this reason, the foreign material inherent in the lens drive part 2 can be reduced. Therefore, imaging defects can be reduced more reliably.

  In the camera module 10, even if the lens holder 21 and the motor holder 24 are integrated, foreign matter stays in the recess 32 a, so that imaging defects are reduced. For this reason, it is not limited to the structure which provides the lens holder 21 and the motor holder 24 which were mutually independent.

  In the camera module 10, the coil 22 is held at the lower end of the lens holder 21, and the optical unit 1 is held inside the lens holder 21. That is, the coil 22 and the optical unit 1 are held by the same member. Therefore, since the configuration is simplified, the camera module 10 can be downsized in the lateral direction (width direction). Of course, the coil 22 and the optical unit 1 may be held by separate holders.

  In addition, the camera module 10 includes a translucent member 34 between the imaging lens 11 and the imaging element 31. That is, the translucent member 34 disposed so as to face the imaging element 31 is provided on the optical path. Thereby, even if the foreign matter in the recess 32 a moves along the outer surface of the sensor cover 33, the movement of the foreign matter to the image sensor 31 is blocked by the translucent member 34. Therefore, it is possible to reliably prevent foreign matter from adhering to the light receiving portion of the image sensor 31.

  In the camera module 10, an adhesive (not shown) may be applied to the inside of the recess 32 a or the outer surface of the sensor cover 33. Thereby, the foreign material which moved into the recessed part 32a or the foreign material which moved to the outer surface of the sensor cover 33 is captured by the adhesive material. For this reason, the foreign material which moved in the recessed part 32a stays reliably in the recessed part 32a. Similarly, the foreign matter that has moved to the outer surface of the sensor cover 33 reliably stays on the outer surface. As a result, it is possible to more reliably prevent foreign matter from entering the optical path. Therefore, imaging defects can be further reduced.

  Thus, the adhesive material functions as a dust trap agent. The adhesive material is not particularly limited as long as it has adhesiveness. For example, semi-solid (or a state close to solid) oil or resin can be applied. For example, grease is suitable. Grease is a kind of fats and oils that are semi-solid or nearly liquid, and can be composed of, for example, a semi-solid (or a state close to a solid) or a paste-like lubricant. As the grease, for example, a molybdenum disulfide lubricant, a white lubricant, a silicone lubricant, a perfluoropolyether lubricant, or the like can be used. The greases are mineral oil-based greases mainly composed of mineral oil, poly-α-olefin-based greases composed mainly of poly-α-olefin oil, silicone-based greases composed mainly of silicone oil, fluorosilicone-based greases, perfluoro A perfluoropolyether-based grease containing a polyether as a main component can be used. These greases can be used alone or in admixture of two or more. Further, the grease may include an additive for grease such as lithium soap, calcium soap, polytetrafluoroethylene (PTFE), and the like.

  The application area of the adhesive material is not particularly limited. However, if the application area is wide, the effect of capturing foreign matter can be enhanced. On the other hand, if the application area is narrow, the amount of the adhesive material used can be reduced.

  In the camera module 10, the substrate 32 is preferably a ceramic substrate. If the substrate 32 is made of a ceramic substrate, dust is not easily generated even when the concave portion 32a and the lens driving portion 2 (lens holder 21) provided in the concave portion 32a are rubbed when the optical portion 1 is driven. Therefore, foreign matter generated when the camera module 10 is used can be reduced. Furthermore, since the ceramic substrate can be easily processed, the concave portion 32a can be formed on the substrate 32 with high accuracy. Therefore, the lens driving unit 2 can be mounted in the recess 32a with high accuracy. In the present embodiment, the permanent magnet 23 is provided in the motor holder 24 of the lens driving unit 2, but the permanent magnet 23 may be provided in the recess 32 a of the substrate 32. Also in this case, the substrate 32 is preferably a ceramic substrate.

(Camera module manufacturing method)
Next, an example of a method for manufacturing the camera module 10 will be described. 4A to 4E are cross-sectional views illustrating the manufacturing process of the camera module 10 of FIG.

  First, as shown in FIG. 4A, the image sensor 31 and necessary components such as a capacitor are mounted on the substrate 32 on which the recess 32a is formed. Further, the substrate 32 and the components mounted on the substrate 32 are electrically connected by wire bonding or the like.

  Next, as shown in FIG. 4B, the sensor cover 33 holding the translucent member 34 in advance is mounted on the substrate 32. As a result, the image sensor 31 is covered with the sensor cover 33 and accommodated inside the sensor cover 33. Further, the translucent member 34 can prevent foreign matter from adhering to the image sensor 31 during the manufacturing process.

  Next, as shown in FIG. 4C, the lower leaf spring 25 b is fitted into the recess 32 a of the substrate 32. Next, as shown in FIG. 4D, the lens holder 21 holding the imaging lens 11 and the lens barrel 12 is fitted into the recess 32 a of the substrate 32.

  Finally, as shown in FIG. 4E, the upper leaf spring 25a is placed on the upper surface of the lens holder 21. Then, the motor holder 24 holding the permanent magnet 23 is fitted into the recess 32a so that the permanent magnet 23 is disposed in the recess 32a. Thereby, manufacture of the camera module 10 is completed.

  Thus, in the camera module 10, the bottom part of the lens holder 21, the coil 22, the permanent magnet 23, and the lower leaf spring 25b are fitted into the recess 32a. Further, both the coil 22 and the permanent magnet 23 are provided in the recess 32 a of the substrate 32. Thereby, the lens drive part 2 can be formed on the imaging part 3 only by fitting the coil 22 held by the lens holder 21 and the permanent magnet 23 held by the motor holder 24 in the recess 32a. Accordingly, the camera module 10 can be easily manufactured.

  In particular, when the substrate 32 is a ceramic substrate, it can be easily processed. Therefore, the lens holder 21 and the motor holder 24 can be mounted on the substrate 32 with high precision simply by fitting into the recess 32a. Therefore, the camera module 10 can be easily assembled. In FIG. 4, the coil 22 and the permanent magnet 23 are all provided in the recess 32a. However, the present invention is not limited to this, and at least a part of the coil 22 and the permanent magnet 23 is provided in the recess 32a. It only has to be done.

  In addition, before the lens holder 21 or the motor holder 24 is fitted into the recess 32a, foreign matter previously attached to the lens driving unit 2 may be removed by blowing air or the like. Thereby, the foreign material which exists in the camera module 10 (lens drive part 2) can be reduced.

(Another camera module 20)
The camera module 10 described above can be configured as follows. FIG. 5 is a cross-sectional view showing another camera module 20 of the present invention. The camera module 20 is different from the above-described camera module 10 in the shape of the sensor cover 33. Hereinafter, the camera module 20 will be described focusing on differences from the camera module 10.

  In the camera module 10 of FIG. 1, the outer surface of the sensor cover 33 is flush with the inner surface of the recess 32a (the inner wall surface on the image sensor 31 side). For this reason, when the lens drive unit 2 is driven, the foreign matter staying in the recess 32 a may move along the outer surface of the lens holder 21 as the lens holder 21 moves up and down. As a result, when the lens holder 21 is repeatedly raised and lowered, foreign matter may enter the optical path.

  Therefore, in the camera module 20 of FIG. 5, a part of the outer surface of the sensor cover 33 is closer to the image sensor 31 than the inner surface of the recess 32a. Specifically, a notch 33 a is formed on the outer periphery of the bottom (lower end) of the sensor cover 33. Thereby, the outer surface of the bottom part of the sensor cover 33 is arrange | positioned inside the board | substrate 32 rather than the inner surface of the recessed part 32a in the location in which the notch 33a was formed. That is, a part of the outer surface of the sensor cover 33 is disposed closer to the image sensor 31 than the inner surface of the recess 32a. For this reason, even if the foreign matter staying in the recess 32a is moved along the inner surface of the recess 32a as the lens driving unit 2 is driven, the foreign matter stays in the notch 33a. That is, the notch 33a functions as a capturing part (trap part) that captures foreign matter. As a result, it is possible to more reliably prevent foreign matter from entering the optical path. Therefore, imaging defects can be further reduced.

  In the camera module 20, a notch 33 a is formed at the bottom of the sensor cover 33. However, the formation part of the notch 33a is not particularly limited as long as it is the outer surface of the lens holder 21. Further, the entire outer surface of the sensor cover 33 may be arranged closer to the image sensor 31 than the inner surface of the recess 32a. Even with such a sensor cover 33, the same effect can be obtained.

  Further, the above-described adhesive material may be applied to the notch 33 a of the sensor cover 33. Thereby, the foreign material moved into the notch 33a is captured by the adhesive material. For this reason, the foreign material that has moved into the notch 33a is reliably retained in the notch 33a. As a result, it is possible to more reliably prevent foreign matter from entering the optical path. Therefore, imaging defects can be further reduced.

  Note that an adhesive material may be applied to a region other than the notch 33 a of the sensor cover 33. For example, if an adhesive material is applied near the upper portion of the sensor cover 33, the foreign matter can be captured immediately before the foreign matter enters the optical path from the opening on the upper portion of the sensor cover 33 (on the imaging lens 11 side). On the other hand, if an adhesive is applied to the outer surface near the bottom of the sensor cover 33, the foreign matter in the recess 32a is captured immediately after moving to the bottom of the sensor cover 33 along the inner surface of the recess 32a. can do.

  As described above, in the camera modules 10 and 20 according to the present embodiment, the bottom portion (the coil 22 and the permanent magnet 23) of the lens driving unit 2 is provided in the recess 32 a formed in the substrate 32. As a result, the foreign matter that has moved along the outer edge of the lens holder 21 accumulates in the recess 32 a that is below the translucent member 34 rather than the imaging element 31. For this reason, it is very difficult for foreign matter to enter the optical path. As a result, entry of foreign matter into the optical path can be reliably prevented. Accordingly, it is possible to reduce imaging defects due to foreign matters.

  In the present embodiment, the camera module 10 that drives the optical unit 1 in the optical axis direction by the electromagnetic force generated by the coil 22 and the permanent magnet 23 has been described. That is, in the present embodiment, the camera module 10 including the VCM type lens driving unit 2 has been described. However, the lens driving unit applied to the camera module of the present invention is not limited to the VCM type. For example, other types of lens driving units such as a type using a stepping motor and a type using a piezoelectric element can be applied.

  The camera module of the present embodiment can be suitably used for electronic devices such as mobile phones and digital still cameras. Since the camera module of this embodiment has a simple structure, it is easy to assemble. Moreover, since entry of foreign matter can be reduced, a highly reliable camera module and electronic device can be provided.

In addition, this invention can also be expressed as follows.
[1] An optical unit having an imaging lens and a lens holding member (lens barrel) that holds the imaging lens, a lens driving unit that moves the imaging lens in the optical axis direction, and light incident through the imaging lens A camera module including an imaging unit having an imaging element that converts an electrical signal and a substrate unit on which the imaging element is mounted, wherein at least a part of the lens driving unit is provided on the substrate unit A camera module, wherein the camera module is inserted into a recess.
[2] The lens drive unit includes a holder unit, a coil fixed to an outer peripheral end of the holder unit, and a magnet fixed to face the coil. The camera module as described in.
[3] The holder unit includes a first holder unit that holds the optical unit therein, and a second holder unit that includes a coil of the lens driving unit at an outer peripheral end. [2] The camera module according to [2].
[4] The camera module according to [2] or [3], wherein the coil and the magnet are in a recess provided in the substrate.
[5] The above-mentioned [1], wherein a translucent member is provided between the imaging lens and the imaging element, and a part or all of the lens driving unit is located below the translucent member. ] To [4] The camera module according to any one of [4].
[6] The camera module according to any one of [1] to [5], wherein the substrate portion is a ceramic substrate.
[7] The camera module according to any one of [1] to [6], wherein the sensor cover that supports the translucent member includes a trap unit (capturing unit) that captures foreign matter.
[8] The camera module according to any one of [1] to [7], wherein a resin intended to trap foreign matter is applied to the trap portion or the concave portion of the substrate.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible in the range shown to the claim. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The camera module of the present invention has a simple structure and can prevent intrusion of foreign matter, and thus has high reliability and is easy to assemble. Therefore, it can be suitably used as a camera module for various electronic devices such as mobile phones and digital still cameras.

DESCRIPTION OF SYMBOLS 1 Optical part 2 Lens drive part 3 Imaging part 10 Camera module 11 Imaging lens 12 Lens barrel (lens holding | maintenance part)
20 Camera module 21 Lens holder (coil holder)
22 Coil 23 Permanent magnet (magnet)
24 motor holder 31 image sensor 32 substrate 32a recess 33 sensor cover 34 translucent member

Claims (8)

An optical unit having an imaging lens and a lens holding unit for holding the imaging lens;
A lens driving unit that drives the optical unit in the optical axis direction; and
A camera module including an imaging unit having an imaging element that converts light incident through the imaging lens into an electrical signal, and a substrate on which the imaging element is mounted,
A recess is formed on the substrate,
At least a part of the lens driving unit is provided in the recess ,
The lens driving unit has a coil and a magnet for driving the optical unit in the optical axis direction by electromagnetic force,
A coil holder for holding the coil;
A motor holder for holding the magnet so as to face the coil;
The coil holder and the motor holder are provided independently of each other,
A camera module , wherein at least a part of the coil and the magnet are provided in a recess of the substrate . The camera module according to claim 1 , further comprising a translucent member disposed opposite to the imaging element between the imaging lens and the imaging element. The coil holder is further camera module according to claim 1 or 2, characterized in that for holding the optical unit therein. A sensor cover that holds the translucent member and accommodates the imaging element therein,
The camera module according to claim 2 , wherein at least a part of the outer surface of the sensor cover is disposed closer to the imaging device than the inner surface of the recess. In the recess of the substrate, a camera module according to any one of claims 1 to 4, the adhesive material is characterized in that it is coated. The camera module according to claim 4 , wherein an adhesive material is applied to an outer surface of the sensor cover. The substrate, a camera module according to any one of claims 1 to 6, characterized in that a ceramic substrate. An electronic apparatus comprising: a camera module according to any one of claims 1-7.

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