JP2007155801A - Camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera module that eliminates the need for a shaft, excels in impact resistance, and avoids an increase in manufacturing cost. <P>SOLUTION: The camera module includes: a lens unit 6; a holder 8 accommodating the lens unit 6 and movable along the optical axis of the camera module 1; a coil 7 disposed in the holder 8; a yoke 92 and a magnet 93 that generate a magnetic field in the coil 7; a plate spring 5 supporting the holder 8; and a base 9 supporting the yoke 92, magnet 93, and plate spring 5. The holder 8 has projections 82 formed integrally with the holder 8. The base 9 has recesses 94 formed integrally with the base 9, and supporting the projections 82 so that the projections may be slidable in the direction of the optical axis of the lens unit 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera module, and more particularly to a camera module that can be used for a relatively small digital camera or a camera-equipped small electronic device such as a camera-equipped mobile phone.

  In a relatively small digital camera or the like, there is a camera module that can move a lens in the optical axis direction by the interaction between a magnetic field generated by a current flowing in a coil and a magnetic field generated by a magnet for the purpose of autofocus and zoom. in use. In recent years, a small camera mounted on a mobile phone is also required to have an autofocus function as the number of pixels of an image sensor becomes 1 million pixels or more. The external dimensions of the camera module mounted on such a cellular phone have, for example, a size of about 10 mm in length, about 10 mm in width, and about 5 mm in thickness.

  FIG. 6 shows a lens driving unit for autofocus of a conventional camera module. The lens driving unit 100 includes a lens unit 101, a lens holder 102 that accommodates the lens unit 101, two sliding support portions 103 that protrude from both sides of the lens holder 102, and each sliding support portion 103. And two shafts 104 slidably engaged. Each shaft 104 is fixed to a camera module main body (not shown) (not shown).

  In the lens driving unit 100, by supplying a current to a coil (not shown) provided in the lens holder 102, the lens holder 102 moves in the vertical direction in FIG. 6 and autofocus is executed. At this time, the slide holder 103 slides while being supported by the shaft 104, so that the lens holder 102 moves along the optical axis direction of the lens unit 101.

  There is a camera module as disclosed in Patent Document 1 as a camera module including the lens driving unit as described above.

Japanese Patent Laid-Open No. 6-102447

  The lens driving unit 100 of the camera module has a problem that the two shafts 104 need to be erected vertically from the camera module body. This is because the optical axis of the lens unit 101 is tilted by the movement of the lens holder 102 during autofocusing unless the shaft 104 is erected so as to be accurately vertical.

  Furthermore, there is a problem that the two shafts 104 must be given sufficient strength. This is because, when an impact is applied to the camera module, the shaft 104 may drop from the camera module body or the shaft 104 itself may be inclined.

  Moreover, since the mounting process of the shaft 104 is required, there is a problem that the manufacturing cost of the camera module increases.

  In view of the above problems, an object of the present invention is to provide a camera module that does not use a shaft, has excellent impact resistance, and can avoid an increase in manufacturing cost.

  A camera module according to a first aspect of the present invention is provided with a lens unit that constitutes an optical system of the camera module, a holder that accommodates the lens unit and is movable along the optical axis direction of the camera module, and the holder. A coil, a yoke and a magnet for providing a magnetic field to the coil, a leaf spring for supporting the holder, and a base for supporting the yoke, the magnet and the leaf spring. A first sliding means formed integrally with the holder, wherein the base is formed integrally with the base, and the first sliding means is slidable in the optical axis direction of the lens unit; It has the 2nd sliding means currently supported in this, It is characterized by the above-mentioned.

  In the camera module according to a second aspect of the present invention, the first sliding means is a plurality of protruding pieces formed on a side portion of the holder, and the second sliding means corresponds to the protruding pieces. It is preferable that the recess is formed in the base.

  According to a third aspect of the present invention, in the camera module, the first sliding means is a plurality of protrusions formed on a bottom portion of the holder, and the second sliding means corresponds to the protrusion. A sliding hole formed in the base is preferable.

  According to a fourth aspect of the present invention, there is provided the camera module according to the fourth aspect, wherein the camera module is further fixed to the base and a cover provided to cover the holder and a stopper member provided below the cover. Preferably, a gap is formed between the bottom surface of the cover and the top surface of the holder by the stopper member.

  In the camera module according to the fifth aspect of the present invention, it is preferable that ringing prevention means is provided at a sliding portion between the holder and the base.

  In the camera module according to the sixth aspect of the present invention, it is preferable that the ringing prevention means is a gel-like resin.

  The camera module according to the first aspect of the present invention is such that the first sliding means formed integrally with the holder is slidable in the optical axis direction of the lens unit by the second sliding means formed on the base. It is supported. For this reason, the holder can move only along the optical axis direction, and movement in directions other than the optical axis direction is restricted. Since the first sliding means is formed integrally with the holder, and the second sliding means is formed integrally with the base, a member such as a shaft for slidably supporting the holder is provided. do not need. Accordingly, a process for mounting a member such as a shaft is not required, and the manufacturing cost of the camera module can be reduced.

  In the camera module according to the second aspect of the present invention, since the protruding piece is formed on the side portion of the holder, the overall height of the camera module can be reduced. Therefore, the camera module can be reduced in size.

  In the camera module according to the third aspect of the present invention, the first sliding means is a plurality of protrusions formed on the bottom of the holder, and the second sliding means is a sliding hole formed on the base. By configuring the first sliding means and the second sliding means in this way, the size of the camera module in the width direction can be reduced, and downsizing of the camera module can be achieved.

  According to a fourth aspect of the present invention, the camera module includes a stopper member that is fixed to the base and provided below a cover that is provided so as to cover the holder. By this stopper member, a gap is formed between the bottom surface of the cover and the top surface of the holder, and when an impact is applied to the camera module, it is possible to prevent the top surface of the holder from moving and colliding with the bottom surface of the cover. .

  According to a fifth aspect of the present invention, the camera module according to the present invention is provided with a ringing prevention means at a sliding portion between the holder and the base. By this ringing prevention means, it is possible to effectively reduce the ringing of the holder during execution of autofocusing or the like.

  The camera module according to the present invention described in claim 6 uses a gel-like resin as ringing prevention means. Therefore, there is an advantage that the optimum viscosity adjustment as a ringing prevention means can be easily performed and the manufacturing cost is extremely low.

  Hereinafter, a camera module 1 according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional explanatory view of the camera module 1 of the present embodiment, and FIG. 2 is an exploded perspective view thereof. Note that the terms “upper” and “lower” used in the present specification refer to the direction in which the cover 2 of the camera module is disposed as the top and the direction in which the base 9 is disposed as the bottom.

  The camera module 1 is provided in the lens unit 6 constituting the optical system of the camera module 1, a holder 8 that houses the lens unit 6 and is movable along the optical axis direction of the camera module 1, and the holder 8. A coil 92, a yoke 92 and a magnet 93 that provide a magnetic field to the coil 7, a leaf spring 5 that supports the holder 8, and a base 9 that supports the yoke 92, the magnet 93, and the leaf spring 5. The holder 8 has a projecting piece 82 which is a first sliding means formed integrally with the holder 8, and the base 9 is formed integrally with the base 9, It has a concave portion 94 as a second sliding means for supporting the protruding piece 82 as the first sliding means so as to be slidable in the optical axis direction of the lens unit 6. .

  Further, the camera module 1 is fixed to the base 9 and also has a cover 2 provided so as to cover the holder 8, a stopper member 3 provided below the cover 2, and the stopper member 3. And a flexible printed circuit board 4 provided below the circuit board. The camera module 1 also includes a lower base 10 provided below the base 9, a substrate 11 provided below the lower base 10, and an image sensor 12 disposed at the center of the surface of the substrate 11. have.

  The cover 2 is provided so as to cover the holder 8 and is integrally formed by processing a stainless steel metal plate, and a central hole 21 is formed in the central portion. Further, the cover 2 has side plates 22 having engagement holes 23 for engaging with engagement protrusions 98 of the base 9 described later at the four corners thereof.

  As shown in FIG. 2, the stopper member 3 is a rectangular frame made of synthetic resin. The stopper member 3 is fixed to the upper surface of the base 9 and is provided below the cover 2. A gap is formed between the bottom surface of the cover 2 and the top surface of the holder 8, and when an impact is applied to the camera module 1, the top surface of the holder 8 moves to the bottom surface of the cover 2 and collides with it. It is preventing.

  The flexible printed circuit board 4 is a flexible thin plate-shaped printed circuit board for supplying a current to the coil 7 described later from the outside.

  The leaf spring 5 is a beryllium copper leaf spring, and supports the holder 8 in the center hole 51 so as to be swingable.

  The lens unit 6 is a synthetic resin-made cylindrical member that houses a plurality of lenses therein, and a thread 61 is formed on the outer peripheral surface thereof. The thread 61 is screwed to a thread 80a (see FIG. 3) inside the center hole 80 of the holder 8 described later.

  The coil 7 is a drive coil for the holder 8 that is turned in a rectangular shape, and is attached to the outer periphery of the holder 8 to be described later.

  The holder 8 has a holder body 81 that is a rectangular synthetic resin member, and a central hole 80 is formed at the center of the holder body 81 in order to accommodate the lens unit 6. Further, four projecting pieces 82 as first sliding members are integrally formed on the four corner sides of the holder body 81. The protruding piece 82 protrudes toward the side and the lower side of the holder main body 81 and is slidably inserted into a concave portion 94 which is a second sliding means formed on the base 9 described later. The coil 7 is supported on the sides of the four projecting pieces 82.

  A slide groove 83 is formed inside the holder body 81 (see FIG. 1), and a slide wall 96 of the base 9 described later is slidably inserted into the slide groove 83.

  The base 9 has a base body 91 which is a rectangular synthetic resin member, and yokes 92 which are iron plates formed in a U-shaped cross section are respectively incorporated on four side surfaces thereof. A magnet 93 is adhered to the inside of the yoke 92 with an adhesive, and the magnet 93 constitutes a magnetic circuit together with the yoke 92. As shown in FIG. 1, this magnetic circuit provides a magnetic field for driving the coil 7.

  At the four corners of the base 9, four concave portions 94 as second sliding means are formed. Each recess 94 has a shape corresponding to the shape of each protruding piece 82 of the holder 8.

  A central hole 90 is formed at the center of the base body 91, and a sliding wall 96 is formed around the central hole 90. The sliding wall 96 is slidably inserted into the sliding groove 83 of the holder body 81. Further, in the gap between the sliding wall 96 and the sliding groove 83, as shown in FIG. 4, a gel-like resin 96a which is a ringing prevention means is provided.

  Hereinafter, functions and effects of the camera module of the present embodiment will be described.

  In this camera module 1, when a current is supplied to the coil 7 through the flexible printed circuit board 4, the holder 8 that holds the coil 7 by the action of the magnetic field formed by the yoke 92 and the magnet 93 of the base 9. Moves along the optical axis direction of the lens unit 6, and autofocus is executed.

  The movement of the holder 8 is such that the protruding piece 82 which is the first sliding means formed on the holder 8 is moved in the optical axis direction of the lens unit 6 by the concave portion 94 which is the second sliding means formed on the base 9. It is regulated by being slid while being guided by. For this reason, the holder 8 can move only along the optical axis direction, and movement in directions other than the optical axis direction is restricted.

  The projecting piece 82 as the first sliding means is formed integrally with the holder 8, and the concave portion 94 as the second sliding means is formed integrally with the base 9, so that the holder can slide. There is no need for a member such as a shaft for support. Accordingly, a process for mounting a member such as a shaft is not required, and the manufacturing cost of the camera module can be reduced.

  Moreover, since the protrusion piece 82 is formed in the side part of the holder 8, the whole height of the camera module 1 can be comprised low. Therefore, the camera module 1 can be reduced in size.

  In the present embodiment, the first sliding means is configured as a protruding piece, and the second sliding means is configured as a recess, but the first sliding means is a plurality of protrusions formed on the bottom of the holder 8, The second sliding means may be a sliding hole formed in the base 9. By configuring the first sliding means and the second sliding means in this manner, the size of the camera module in the width direction can be reduced, and the camera module 1 can be reduced in size.

  The camera module 1 has a stopper member 3 that is fixed to the base 9 and provided below the cover 2 that is provided so as to cover the holder 8. The stopper member 3 forms a gap between the bottom surface of the cover 2 and the top surface of the holder 8. When an impact is applied to the camera module 1, the top surface of the holder 8 moves and collides with the bottom surface of the cover 2. Can be prevented.

  Further, a gel-like resin 96a as an anti-ringing means is provided in a gap between the sliding groove 83 and the sliding wall 96, which are sliding portions between the holder 8 and the base 9. This ringing prevention means can effectively reduce ringing during execution of autofocus. As shown in FIG. 5, this ringing means that when the holder 8 is subjected to a predetermined displacement, an undesirable vibration is generated due to the repulsion of the leaf spring 5 after the holder 8 is displaced beyond the predetermined displacement. And by using this gel-like resin 96a, the gel-like resin 96a converts the undesirable vibration of the holder 8 into thermal energy. By using the gel resin 96a, there is an advantage that the optimum viscosity adjustment as a ringing prevention means can be easily performed and the manufacturing cost is extremely low.

  In the above embodiment, the first sliding member and the second sliding member in autofocus have been described. However, in addition to the autofocus mechanism, a similar configuration can be used for the zoom mechanism.

It is a section explanatory view of camera module 1 of an embodiment concerning the present invention. It is a disassembled perspective view of the camera module 1 shown in FIG. It is an expansion perspective view of the holder 8 and the base 9 of the camera module 1 shown in FIG. It is a cross-sectional enlarged view which shows the periphery of the sliding wall 96, the sliding groove | channel 83, and the gel-like resin 96a of the camera module 1 shown in FIG. In the camera module 1 shown in FIG. 1, it is a graph which shows the ringing state of the holder 8 when not providing the gel-like resin 96a. It is a perspective view which shows the lens drive part 100 of a well-known camera module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera module 10 Lower base 11 Board | substrate 12 Image pick-up element 2 Cover 21 Center hole 22 Side plate 23 Engagement hole 3 Stopper member 4 Flexible printed circuit board 5 Plate spring 51 Center hole 6 Lens unit 61 Screw thread 7 Coil 7
8 Holder 80 Central hole 80a Thread 81 Holder body 82 Projection piece 83 Sliding groove 9 Base 90 Central hole 91 Base body 92 Yoke 93 Magnet 94 Recess 96 Sliding wall 96a Gel resin 96 Sliding wall 98 Engaging protrusion 100 Lens Drive unit 101 Lens unit 102 Lens holder 103 Sliding support unit 104 Shaft

Claims (6)

A lens unit constituting the optical system of the camera module;
A holder that accommodates the lens unit and is movable along the optical axis direction of the camera module;
A coil provided in the holder;
A yoke and a magnet for providing a magnetic field to the coil;
A leaf spring supporting the holder;
A base that supports the yoke and the magnet and the leaf spring;
The holder has first sliding means formed integrally with the holder,
The base has a second sliding means that is formed integrally with the base and supports the first sliding means so as to be slidable in the optical axis direction of the lens unit. A featured camera module.   The first sliding means is a plurality of protruding pieces formed on a side portion of the holder, and the second sliding means is a recess formed in the base so as to correspond to the protruding pieces. The camera module according to claim 1.   The first sliding means is a plurality of protrusions formed on the bottom of the holder, and the second sliding means is a sliding hole formed in the base so as to correspond to the protrusions. The camera module according to claim 1. The camera module further includes a cover fixed to the base and provided to cover the holder and a stopper member provided below the cover,
The camera module according to claim 1, wherein a gap is formed between the bottom surface of the cover and the top surface of the holder by the stopper member.   The camera module according to claim 1, wherein a ringing preventing means is provided at a sliding portion between the holder and the base. The camera module according to claim 5, wherein the ringing prevention means is a gel resin.

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