JP2006017821A - Lens drive mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the dimensions and the assembly steps of a camera lens drive mechanism while realizing an automatic variable magnification function and an automatic focusing function. <P>SOLUTION: A configuration is adopted to form a projecting wall 82 facing the cylindrical cover 80 surrounding the cams 20, 30 and the lens frames 40 and 50, and to fix the motor 90 and the speed reducer 100 of the drive mechanism to the surfaces 82a and 82b of the wall to turn the cams 20, 30. Thus, the space of the drive mechanism can be minimized since it is completely attached directly inside the cover 80, resulting in making it easy to built in portable information terminals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lens driving device including a driving source that automatically moves a lens in an optical axis direction, and in particular, a lens applied to a camera mounted on a portable information terminal such as a mobile phone or a portable personal computer. The present invention relates to a driving device.

  A camera mounted on a portable information terminal such as a mobile phone or a portable personal computer needs to be as small as possible because the mounting space for the portable information terminal is small. For this reason, the camera mounted on the portable information terminal is based on a manual operation even if it has a scaling function and a focal length adjustment function (see, for example, Patent Documents 1 and 2).

JP 2003-060764 A JP 2003-005017 A

By the way, when a camera that performs zooming by manual operation is mounted on a portable information terminal, the operability is poor because it is necessary to take an image while operating an operation unit provided in a small camera.
On the other hand, in order to provide an automatic magnification function to a camera mounted on a portable information terminal, it is necessary to relatively move a plurality of lens groups in the optical axis direction, and a motor or a speed reducer is used as a drive mechanism. Necessary. In particular, in order to automatically perform the focusing operation (focusing) at each magnification position in addition to the automatic magnification operation, it is necessary to move a plurality of lens groups independently in the optical axis direction. Multiple motors and speed reducers are required.
Therefore, if the space occupied by the motor and the speed reducer is large, it becomes difficult to incorporate them in the narrow mounting space of the portable information terminal. In addition, the number of assembling steps for assembling the motor and the speed reducer to the portable information terminal increases.

  The present invention has been made in view of the above-described prior art, and the object of the present invention is to be mounted in a small space such as a portable information terminal while realizing an automatic zooming function and an automatic focusing function. An object of the present invention is to provide a lens driving device for a camera.

The lens driving device of the present invention includes a plurality of lens frames that hold a lens and are arranged in the optical axis direction, and a plurality of cam frames that are rotatably supported and that move the plurality of lens frames in the optical axis direction. A cam body, a plurality of lens frames and a cover member formed in a cylindrical shape surrounding the plurality of cam bodies, a motor, and a gear train that decelerates the rotation of the motor and outputs it to a gear portion formed on the cam body. And a plurality of drive mechanisms that respectively drive the plurality of cam bodies, and the cover member has an attachment portion that directly attaches the plurality of drive mechanisms.
According to this configuration, the plurality of cam frames can be independently rotated in the direction of the optical axis by independently rotating the plurality of cam bodies by the driving mechanisms corresponding thereto, and automatic zooming operation and automatic focusing can be performed. Both operations can be realized.
Further, it is possible to reduce the size by attaching all of the plurality of driving mechanisms to the plurality of attachment portions formed on the cover member, and for example, the lens driving device can be easily incorporated into a portable information terminal or the like.
Furthermore, the rotation of the motor can be decelerated by a reduction gear and given to the cam body, and the rotational position of the cam body can be finely adjusted without precisely controlling the rotational position of the motor. By forming the gear portion, the device can be easily assembled.

In the above-described configuration, the motor may be configured such that each rotation axis is disposed along the optical axis direction and at least partially opposed in the circumferential direction.
According to this configuration, according to this configuration, since the plurality of motors are at least partially opposed in the circumferential direction, the driving mechanism can be integrated in the optical axis direction.

In the above configuration, the attachment portion is formed to protrude from the outer wall of the cover member corresponding to the plurality of protruding wall portions that protrude from the outer wall of the cover member and face each other in the optical axis direction. It is possible to adopt a configuration in which a plurality of holding portions are provided, one end portion of the motor is fixed to the protruding wall portion, and the other end portion of the motor is held in the holding portion.
According to this configuration, a plurality of motors can be arranged together between the opposing protruding wall portions, so that the drive mechanism can be integrated and both end portions of the motor can be held, so that the motor can be prevented from dropping due to impact or the like. It can be surely prevented.

The said structure WHEREIN: The structure which is provided in the wall surface on the opposite side to the wall surface of the protrusion wall part to which the motor was fixed is employable.
According to this configuration, the speed reducer and the motor can be separated via the protruding wall portion, so that assembly is facilitated, and spaces near both wall surfaces of the protruding wall portion can be effectively utilized.

The said structure WHEREIN: The some gearwheel which forms a gear train can employ | adopt the structure supported rotatably by the some support shaft fixed to the protrusion wall part in the shape of a cantilever.
According to this structure, the assembly | attachment operation | work to the cover member of a gearwheel becomes easy.

In the above-described configuration, the cover member has one end portion of a plurality of compression springs that urge each of the cover members in the direction of separating the lens frames in the optical axis direction so as to maintain engagement with the plurality of cam bodies. It is possible to adopt a configuration having a spring receiving portion for commonly receiving the.
According to this configuration, a compression spring can be provided in each of the plurality of lens frames, and the engagement with the corresponding cam body can be reliably maintained. In addition, by forming the spring receiving portion on the cover member, the number of parts and the number of assembly steps can be reduced, and the apparatus can be downsized.

In the above-described configuration, the rotational position detector that detects the rotational position of at least one of the plurality of cam bodies is fixed to the cover member, and the cam body is formed to protrude radially outward adjacent to the gear portion. A configuration having a detected portion detected by a detector can be employed.
According to this configuration, the position of the lens (lens frame) in the optical axis direction can be detected from the rotational position of the cam body, the detected portion is formed on the cam body, and the rotational position detector is provided on the cover member. The size of the apparatus can be reduced.

  According to the lens driving device of the present invention, the space occupied by the drive mechanism can be minimized while realizing the automatic zooming function and the automatic focusing function, and can be easily incorporated into a narrow mounting space such as a portable information terminal. It becomes.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 9 show an embodiment of a lens driving device according to the present invention. FIG. 1 is a schematic perspective view of the device, FIG. 2 is a cross-sectional view showing the internal structure of the device, and FIG. 4 is an exploded perspective view of the lens barrel portion, FIG. 4 is a plan view of the apparatus viewed from above, FIGS. 5 to 7 are cross-sectional views showing the internal structure of the apparatus, and FIG. 8 is a cross-sectional view showing the relationship of the gears constituting the speed reducer 9 and 9 are cross-sectional views showing the internal structure of the apparatus.

As shown in FIGS. 1 to 9, the lens driving device includes a fixed cylinder 10 that holds a lens G <b> 3, and first and second lenses that are rotatably supported around the optical axis direction L outside the fixed cylinder 10. The cam bodies 20 and 30, the first lens frame 40 holding the lens G1, the second lens frame 50 holding the lens G2, and the first lens frame 40 and the second lens frame 50 are disposed. Compression springs 60 and 61, a holding frame 70 that holds a CCD (charge coupled device) 150, a cover member 80, a motor 90 that constitutes a driving mechanism, and a reduction gear 100 that includes gears 100 a to 100 g, an auxiliary cover member 110, a second A rotational position detector 120 for detecting the rotational position of the cam body 30 is provided.
In addition, a camera unit is formed by holding the CCD 150 as an imaging element in the holding frame 70.

In this apparatus, the lens G3 forms a first lens group, the lens G1 forms a second lens group, and the lens G2 forms a third lens group. Subject light enters the lens G3 from the optical axis direction L, and the lenses G1 and G2 After that, the CCD 150 is reached.
Then, the second lens group (lens G1) and the third lens group (lens G2) are moved relative to each other in the optical axis direction L, so that the zooming operation and focusing of the subject with respect to the imaging surface of the CCD 150 are performed. A focusing operation is performed.

  As shown in FIGS. 1 to 6, the fixed cylinder 10 is formed in a cylindrical shape from a resin material. The fixed cylinder 10 includes a lens holding portion 10a, a step portion 10d, an inner peripheral surface 10f, three guide holes 10g, outer peripheral surfaces 10h and 10h ', and the like.

The lens holding portion 10a is formed in a cylindrical shape at the tip end in the optical axis direction L, and holds the lens G3 on the inner periphery.
The outer peripheral surface 10h is formed in a cylindrical shape behind the lens holding portion 10a and has an outer diameter smaller than the outer diameter of the lens holding portion 10a. The outer peripheral surface 10h supports the first cam body 20 so as to be rotatable around the optical axis.
The outer peripheral surface 10h ′ is formed so as to have an outer diameter smaller than that of the outer peripheral surface 10h behind the outer peripheral surface 10h. The outer peripheral surface 10h ′ supports the second cam body 30 so as to be rotatable around the optical axis.
The step portion 10d is formed between the outer peripheral surface 10h and the outer peripheral surface 10h ′, and comes into contact with an annular projecting portion 81d, which will be described later, of the cover member 80, so that the cover member 80 and the fixed cylinder 10 are relatively in the optical axis direction L. Define the location.

The inner peripheral surface 10f supports the first and second lens frames 40 and 50 so as to be movable in the optical axis direction L.
Three guide holes 10g extend in the optical axis direction L behind the lens holding portion 10a and are formed at equal intervals around the optical axis. The guide hole 10g receives three projecting pieces 41 and 51 (described later) of the first and second lens holding frames 40 and 50, and rotates the first and second lens holding frames 40 and 50 around the optical axis. And is guided in the optical axis direction L.

The first cam body 20 moves the first lens frame 40 in the optical axis direction L by a cam action. The first cam body 20 is formed in a cylindrical shape from a resin material, and as shown in FIGS. 2 and 3, an inner peripheral surface 20f that is rotatably supported by the outer peripheral surface 10h of the fixed cylinder 10, and the optical axis direction The cam surface 21 exerts a cam action on the first lens frame 40 formed on the rear end surface of L, the gear portion 25 formed in an arc shape on the outer periphery of the front end portion in the optical axis direction L, and the like.
The cam surface 21 is formed corresponding to each of three protruding pieces 41 of the first lens frame 40 described later.
The gear unit 25 meshes with the output gear 100 g of the reduction gear 100. Thereby, the rotational force of the motor 90 is transmitted to the first cam body 20 via the speed reducer 100.

The second cam body 30 moves the second lens frame 50 in the optical axis direction L by a cam action. The second cam body 30 is formed of a resin material in a cylindrical shape, and as shown in FIGS. 2, 3, and 5, an inner peripheral surface 30 f that is rotatably supported by the outer peripheral surface 10 h ′ of the fixed cylinder 10. A cam surface 31 that exerts a cam action on the second lens frame 50 formed on the front end surface in the optical axis direction L; a gear portion 35 formed in an arc shape on the outer periphery of the rear end portion in the optical axis direction L; 35 to be detected is formed adjacent to 35.
The cam surface 31 is formed corresponding to each of three protruding pieces 51 of a second lens frame 50 described later.
The gear portion 35 meshes with the output gear 100 g of the speed reducer 100. Thereby, the rotational force is transmitted to the second cam body 30 through the speed reducer 100.
The detected portion 36 is detected by the rotational position detector 120 and is formed integrally with the second cam body 30 so as to protrude radially outward adjacent to one end portion of the gear portion 35. Yes.

  As shown in FIGS. 2 and 5, the rotational position detector 120 is fixed to the outer periphery of the cover member 80, and the light irradiated from the gap 121, the light emitting element 122, and the light emitting element 122 through which the detected part 36 can pass. Light receiving element 123 and the like. The rotational position detector 120 detects the rotational position of the test detection unit 36 when the detection unit 36 blocks light traveling from the light emitting element 122 to the light receiving element 123. By detecting the rotational position of the detected portion 36, the rotational position of the second cam body 30 can be detected.

The first lens frame 40 is made of a resin material and holds the lens G1 as shown in FIGS. The first lens frame 40 is formed so as to be movable in the optical axis direction L and to be supported by the inner peripheral surface 10f of the fixed cylinder 10 and to protrude from the outer peripheral surface 40h. Three projecting pieces 41 are provided.
The three protruding pieces 41 are respectively inserted into the guide holes 10 g of the fixed cylinder 10 and are in contact with the cam surface 21 of the first cam body 20. As a result, the first lens frame 40 is moved only in the optical axis direction L following the profile of the cam surface 21 while its rotation is restricted by the guide hole 10g.

The second lens frame 50 is formed of a resin material, holds the lens G2, and is supported on the inner peripheral surface 10f of the fixed barrel 10 so as to be movable in the optical axis direction L, as shown in FIGS. It has a cylindrical outer peripheral surface 50h and three protruding pieces 51 formed so as to protrude from the outer peripheral surface 50h.
The three protruding pieces 51 are respectively inserted into the guide holes 10 g of the fixed cylinder 10 and are in contact with the cam surface 31 of the second cam body 30. As a result, the second lens frame 50 moves only in the optical axis direction L following the profile of the cam surface 31 while being restricted in rotation by the guide hole 10g.

  As shown in FIGS. 2, 3, and 7, the compression spring 60 is formed of a coiled spring, and is sandwiched between a first lens frame 40 and a spring receiving portion 85 (to be described later) of the cover member 80. A biasing force is applied to press the protruding pieces 41 of the first lens frame 40 against the cam surface 21. The compression spring 60 is for constantly engaging the projecting piece 41 and the cam surface 21 to obtain a stable cam action.

  As shown in FIGS. 2, 3 and 6, the compression spring 61 is formed of a coiled spring, and is sandwiched between a second lens frame 50 and a spring receiving portion 85 (to be described later) of the cover member 80. A biasing force is applied to press the protruding pieces 51 of the second lens frame 50 against the cam surface 31. That is, the compression spring 61 urges the second lens frame 50 in a direction opposite to the compression spring 60 in the optical axis direction L. The compression spring 61 is for constantly engaging the protruding piece 51 and the cam surface 31 to obtain a stable cam action.

The holding frame 70 is formed in a substantially disk shape by a resin material, and as shown in FIGS. 2 and 3, an opening 71 through which subject light is formed at the center and a CCD 150 formed at the center are mounted. CCD mounting portion 72.
The holding frame 70 is joined to the annular rear end surface 10e of the fixed cylinder 10 and the rear end portion of the cover member 80 with an adhesive or the like. As shown in FIG. 2, the holding frame 70 is moved in the optical axis direction L of the second cam body 30 so as to face the annular end surface 30 e of the second cam body 30 in a state where it is joined to the fixed cylinder 10. And the second cam body 30 is prevented from falling off the fixed cylinder 10.

  The cover member 80 is formed of a resin material as shown in FIGS. 1, 2, and 4 to 7, and the first and second cam bodies 20 and 30, and the first and second lens frames 40 and 50 are formed. Of the cylindrical portion 81, the two protruding wall portions 82 as mounting portions formed to protrude outside the cylindrical portion 81, the holding portion 83 formed between the protruding wall portions 82, and the cylindrical portion 81. It has a spring receiving portion 85 and the like formed inside.

  The cylindrical portion 81 has a cylindrical inner peripheral surface 81f and a cylindrical inner peripheral surface 81f ′ having an inner diameter smaller than that of the inner peripheral surface 81f. The first and second inner peripheral surfaces 81f and 81f ′ have first and second inner surfaces. The cam bodies 20 and 30 are respectively fitted. An annular projecting portion 81d is formed between the inner peripheral surface 81f and the inner peripheral surface 81f 'so as to be in contact with the stepped portion 10d of the fixed cylinder 10. When the protruding portion 81d and the stepped portion 10d come into contact with each other, the movement of the fixed tube 10 in the optical axis direction L with respect to the cover member 80 is restricted. The cylindrical portion 81 is formed to have a rectangular outer contour at the rear end portion.

As shown in FIGS. 2, 6, and 7, the spring receiving portion 85 is formed in an annular shape, and is connected to the inner peripheral surface (annular protruding portion 81 d) of the tubular portion 81 and three connecting portions. 86 are connected. The connecting portions 86 are inserted through the guide holes 10g of the fixed cylinder 10 respectively. As shown in FIGS. 6 and 7, the spring receiving portion 85 has annular receiving surfaces 85 a and 85 b formed by steps at outer peripheral edge portions on both side surfaces in the optical axis direction. The receiving surface 85 a receives one end of the compression spring 60, and the receiving surface 85 b receives one end of the compression spring 61.
Thus, by forming the spring receiving portion 85 integrally on the cover member 80 and receiving the compression springs 60, 61 in common, the first and second lens frames 40, which move independently and have different amounts of movement. 50 can be energized with an appropriate force, and the number of parts, the number of assembly steps can be reduced, and the apparatus can be downsized.

The two protruding wall portions 82 are opposed to each other in the optical axis direction L and are substantially perpendicular to the optical axis direction L. A stepping motor 90 is fixed to the mutually facing wall surfaces 82a of the protruding wall portion 82, and A speed reducer 100 comprising a plurality of gears 100a to 100g as a gear train is fixed to the opposite wall surface 82b.
An auxiliary cover member 110 can be attached to the protruding wall portion 82 from the wall surface 82 b side so as to cover the reduction gear 100.
The auxiliary cover member 110 is fixed to the protruding wall portion 82 by a screw member 115, and a plurality of support pillars 111 to 113 are formed to protrude toward the protruding wall portion 82 as shown in FIG. The support pillars 111 to 113 have support holes 111a to 113a formed at the tip portions, respectively. The support holes 111a to 113a support the support shafts 101 to 103 by inserting the free ends of the support shafts 101 to 103 of gears 100b to 100g described later.

  Two holding portions 83 project from the flat surface 87 between the opposing projecting wall portions 82. The holding portion 83 has a fitting recess 83 a into which a fitting projection described later of the stepping motor 90 is fitted. It can hold | maintain reliably by fitting a fitting convex part in this fitting recessed part 83a by snap-fit coupling | bonding.

The stepping motor 90 includes a rotating shaft 91, a case 92 that rotatably supports the rotating shaft 91 and accommodates a coil and a permanent magnet, a flange portion 93 formed at one end portion of the case 92, and formed at the other end of the case 92. And a plurality of power supply terminals 95 projecting from the outer wall of the case 92.
The stepping motor 90 has a flange portion 93 as one end portion fixed to the wall surface 82 a of the projecting wall portion 82 with a bolt 96 and a fitting convex portion 94 as the other end portion to the fitting concave portion 83 a of the holding portion 83. It is fitted and held.

As shown in FIGS. 2 to 4, 6, and 7, the stepping motor 90 has bolts 96 on the wall surface 82 a of the protruding wall portion 82 so that the rotation shaft 91 is disposed in the optical axis direction L. It is fixed with. Further, the stepping motor 90 is fixed to the wall surface 82a in parallel so that a part thereof faces in the circumferential direction. Further, the stepping motor 90 is arranged so that the power supply terminal 95 is along the circumferential direction and in opposite directions (outward).
In this way, by disposing the stepping motor 90 between the opposing wall surfaces 82a and disposing at least a part thereof in the circumferential direction, the plurality of stepping motors 90 can be integrated in one place, and the drive mechanism can be reduced in size. Can be realized. Further, by arranging the power supply terminals 95 outwardly, the power supply terminals 95 do not protrude outward in the radial direction of the cover member 80, and an increase in the outer diameter of the apparatus can be prevented.

The speed reducer 100 is provided on each of the wall surfaces 82b of the projecting wall portion 82, and is configured by a plurality of gears 100a to 100g as a gear train formed of a resin material, as shown in FIGS. The rotation of the stepping motor 90 is decelerated and transmitted to the first and second cam bodies 20 and 30.
The gear 100a is fixed to the rotating shaft 91 of the stepping motor 90 that protrudes toward the wall surface 82b through a through hole 82c formed in the protruding wall portion 82.
The gear 100b and the gear 100c, the gear 100d and the gear 100e, and the gear 100f and the gear 100g are integrally formed, and these are rotatably supported by the three support shafts 101, 102, and 103, respectively.
The support shafts 101, 102, and 103 are press-fitted into a through hole 82 d formed in the protruding wall portion 82 and fixed in a cantilever shape, and the output gear 100 g is engaged with the gear portion 35 of the second cam body 30. It is arranged at a position where it can be matched. The gears 100 b to 100 g can be easily assembled to the cover member 80 by press-fitting the three support shafts 101, 102, and 103 into the protruding wall portion 82 and fixing them in a cantilever shape.
The three support shafts 101, 102, 103 are supported by inserting their free ends 101a, 101b, 101c into the support holes 111a, 112a, 113a of the auxiliary cover member 110, respectively. Thereby, it is possible to prevent the support shafts 101, 102, 103 from falling off the protruding wall portion 82.
The gear 100a and gear 100b, the gear 100c and gear 100d, the gear 100e and gear 100f mesh with each other, and the output gear 100g meshes with the gear portions 25 and 35 of the first and second cam bodies 20 and 30, respectively. Accordingly, the rotation of the stepping motor 90 is transmitted to the first and second cam bodies 20 and 30 through the plurality of gears 100a to 100g.

Next, the operation of the lens driving device will be described with reference to FIGS.
The first and second lens frames 40 and 50 of the lens driving device shown in FIG. 2 are in the wide-angle shooting position, and the first and second lens frames 40 and 50 are moved from this position to the telephoto end shooting position. A pulsed drive current is supplied to the power supply terminals 95 of the two stepping motors 90 and rotated in a predetermined direction. The rotation of the stepping motor 90 is decelerated by the speed reducer 100, and the rotation is transmitted from the output gear 100g to the gears 25 and 35 of the first and second cam bodies 20 and 30, and the first and second cam bodies. 20 and 30 rotate around the optical axis.

At this time, the first and second lens frames 40 and 50 move in the optical axis direction L while changing their relative distances by the cam action of the cam surfaces 21 and 31, and telephoto shooting as shown in FIG. To the position.
In order to move the first and second lens frames 40 and 50 to desired imaging positions, it is necessary to move the first and second lens frames 40 and 50 from the current positions to the desired imaging positions. The rotation amount of the stepping motor 90 may be calculated, and a command for the number of pulses corresponding to the rotation amount may be given to the stepping motor 90.

  In focusing at each photographing position, the second cam body 30 is rotated to adjust the position of the second lens frame 50 in the optical axis direction L. At this time, the rotation position of the detected portion 36 of the second cam body 30 is detected by the rotation detector 120 and focused. As a result, the second cam body 30 necessary for focusing can be accurately positioned.

  According to the present embodiment, the stepping motor 90 and the speed reducer 100 as a driving mechanism for rotating the first and second cam bodies 20 and 30 are fixed to the cover member 80 by forming the plurality of protruding wall portions 82. By doing so, all of the plurality of drive mechanisms can be fixed to the cover member 80, and thus the lens drive device can be miniaturized. In addition, when the lens driving device is incorporated into a portable information terminal or the like, a plurality of driving mechanisms can be incorporated in a state of being engaged with the first and second cam bodies 20 and 30, respectively. A lens driving device can be easily incorporated.

  Further, according to the present embodiment, the drive mechanism is configured by the stepping motor 90 and the speed reducer 100, so that the rotation of the stepping motor 90 is decelerated by the speed reducer 100 and the first and second cam bodies 20, 30. Therefore, the rotational positions of the first and second cam bodies 20 and 30 can be finely adjusted without precisely controlling the rotational position of the stepping motor 90.

In addition, according to the present embodiment, the first and second lens frames 40 and 50 are urged by using the separate compression springs 60 and 61, respectively, so that the first and second lens frames 40 that move independently are used. , 50 can be given appropriate force.
In addition, according to the present embodiment, the rotational position detector 120 is installed in the vicinity of the installation area of the speed reducer 100 of the cover member 80, and the rotational position detector 120 is also covered by the auxiliary cover member 110. Reliability can be increased.

Next, an example in which the camera unit 200 including the lens driving device is applied to a portable information terminal will be described with reference to FIG.
FIG. 10 shows a mobile phone of a type that can change the posture of the lid 220 on which the display device is mounted with respect to the main body 210.
The lens barrel portion of the camera unit 200 is fixed in connecting portions 212 and 222 that connect the lid portion 220 and the main body 210.

In the camera unit 200, since the drive mechanism including the stepping motor 90 and the speed reducer 100 is fixed to the cover member 80 together, the stepping step is performed while the lens barrel is incorporated in a narrow space such as the connecting portions 212 and 222. The motor 90, the speed reducer 100, etc. can be built in the main body 210 side.
In this mobile phone, the camera unit 200 performs a scaling operation while operating the operation button 215 of the main body 210. Focusing is automatically performed at each zoom position.

  In the embodiment described above, the case where the drive mechanism is configured by the stepping motor and the speed reducer has been described. However, the present invention is not limited to this, and for example, other motors such as a DC motor can be used. It is also possible to configure the drive mechanism with only a motor without using a reduction gear.

Further, in the above-described embodiment, the case where the lens frames 40 and 50 are provided has been described. However, the present invention is not limited to this, and the present invention is configured in a configuration including one lens frame or three or more lens frames. It is also possible to apply.
In the above-described embodiment, the case where the stepping motor 90 is arranged in parallel to the cover member 80 so as to partially face in the circumferential direction has been described. However, when the total length of the stepping motor 90 is short, the stepping motor 90 is It can also be arranged in series in the optical axis direction L.

In the above-described embodiment, the case where the rotational position detector 120 is provided for the second cam body 30 used for focusing has been described. However, the present invention is not limited to this, and the first embodiment is performed as necessary. The rotational position detector 120 can also be installed for one cam body 20.
In the above-described embodiment, the case where the plurality of gears 100b to 100g are supported by the support shafts 101 to 103 fixed in a cantilever shape has been described. However, the structure in which both ends of the support shafts 101 to 103 are supported and fixed. Or the structure which supports both ends rotatably can be employ | adopted.
In the above-described embodiment, the case where the protruding wall portion 82 is formed on the cover member 80 as an attachment portion to which the drive mechanism is attached has been described. However, the present invention is not limited to this and has a shape other than the protruding wall portion 82. It is also possible.

  In the above-described embodiment, the case where the CCD is used as the image pickup element of the camera unit has been described. However, the present invention is not limited to this, and other image pickup elements such as CMOS (complementary MOS) can be used. is there.

  As described above, the lens driving device of the present invention is applied as a lens driving device for a digital camera unit mounted on a portable information terminal that is required to be reduced in size and weight, such as a cellular phone and a portable personal computer. Of course, it is also useful in other lens optical systems as long as it requires driving of the lens.

It is a general-view perspective view which shows one Embodiment of the lens drive device which concerns on this invention. It is sectional drawing which shows the internal structure of the lens drive device in a wide angle imaging position. It is a disassembled perspective view of the lens-barrel part of a lens drive device. It is the side view which looked at the lens drive device from the upper part. It is sectional drawing of the AA line direction of FIG. It is sectional drawing of the BB line direction of FIG. It is sectional drawing of the CC line direction of FIG. It is sectional drawing which shows the structure of a reduction gear. It is sectional drawing which shows the internal structure of the lens drive device in a telephoto end imaging position. It is a general-view perspective view of the mobile telephone carrying the lens drive device based on this invention.

Explanation of symbols

L ... Optical axis direction G1-G3 ... Lens 10 ... Fixed cylinder 10g ... Guide hole 20 ... First cam body 21 ... Cam surface (cam)
25 ... Gear unit 30 ... Second cam body 31 ... Cam surface (cam)
35 ... gear portion 36 ... detected portion 40 ... first lens frame 41 ... protruding piece 50 ... second lens frame 51 ... protruding piece 60, 61 ... compression spring 70 ... holding frame 71 ... opening 72 ... CCD mounting portion 80 ... cover member 81 ... cylindrical part 82 ... projecting wall parts 82a and 82b ... wall surface 83 ... holding part 83a ... fitting recess 85 ... spring receiving part 85a and 85b ... receiving surface 86 ... connecting part 90 ... stepping motor (motor, drive) mechanism)
91 ... Rotating shaft 92 ... Case 93 ... Flange portion 94 ... Fitting projection 95 ... Power supply terminal 96 ... Bolt 100 ... Speed reducer (drive mechanism)
100a to 100g ... gears (gear train, reducer)
101, 102, 103 ... support shaft 110 ... auxiliary cover members 111, 112, 113 ... support column 115 ... screw member 120 ... rotational position detector 150 ... CCD
200 ... Camera unit

Claims (7)

A plurality of lens frames which hold the lens and are arranged in the optical axis direction; a plurality of cam bodies which are supported rotatably and have a cam action for moving the lens frames in the optical axis direction; and A reduction gear including a cover member formed in a cylindrical shape surrounding the lens frame and the plurality of cam bodies, a motor, and a gear train that decelerates the rotation of the motor and outputs it to a gear portion formed in the cam body; Each having a plurality of drive mechanisms for driving the plurality of cam bodies,
The cover member has an attachment portion for directly attaching the plurality of drive mechanisms.
A lens driving device. The motor is disposed such that each rotation axis is along the optical axis direction and at least a part thereof is opposed in the circumferential direction.
The lens driving device according to claim 1. The attachment portion protrudes from the outer wall of the cover member corresponding to the protruding wall portion and a plurality of protruding wall portions that protrude from the outer wall of the cover member and face each other in the optical axis direction. A plurality of holding portions,
One end of the motor is fixed to the protruding wall,
The holding portion holds the other end of the motor.
The lens driving device according to claim 1 or 2, wherein The speed reducer is provided on a wall surface opposite to the wall surface of the protruding wall portion to which the motor is fixed.
The lens driving device according to claim 3. The plurality of gears forming the gear train are rotatably supported by a plurality of support shafts fixed in a cantilever shape to the protruding wall portion.
The lens driving device according to claim 3 or 4, wherein The cover member has a common end portion of a plurality of compression springs that urge each of the plurality of lens frames in a direction to separate them in the optical axis direction so as to maintain engagement with the plurality of cam bodies. Having a spring receiving part
The lens driving device according to claim 1, wherein the lens driving device is a lens driving device. A rotational position detector for detecting a rotational position of at least one of the plurality of cam bodies is fixed to the cover member;
The cam body includes a detected portion that is formed to protrude radially outward adjacent to the gear portion and is detected by the rotational position detector.
The lens driving device according to claim 1, wherein the lens driving device is a lens driving device.

Images