JP4668167B2 - Lens drive device - Google Patents

Description

  The present invention relates to a lens driving device for driving a lens mounted on a digital camera, a silver salt film camera, and the like, and in particular, includes a driving motor, a lead screw, a gear train, and a nut, and the rotational driving force of the motor is applied to the lens frame. The present invention relates to a lens driving device for transmission.

  As a conventional lens driving device, there are a base, a fixed cylinder fixed to the base, a lens frame supported inside the fixed cylinder so as to be reciprocable in the optical axis direction, a driving motor fixed to the base, and a rotation shaft of the driving motor. A lead screw formed by extending in the optical axis direction and a nut fixed to a part of the lens frame so as not to rotate and screwed into the lead screw. When the drive motor rotates, the lead screw It is known that the nut is moved in the optical axis direction while rotating and the lens frame is moved in the optical axis direction together with the movement of the nut (for example, see Patent Document 1).

  However, in this lens driving device, since the lead screw is directly connected to the rotation shaft of the driving motor, the lead screw and the driving motor are included especially when driving a lens optical system in which the lens movement amount is relatively large. The overall length of the drive mechanism in the optical axis direction is long, and it is difficult to reduce the size and thickness of the device.

  Other lens driving devices include a base, two guide shafts that are fixed to the base and extend in the optical axis direction, are supported so as to be movable in the optical axis direction with respect to the two guide shafts, and are internally threaded (nuts). ), A drive motor fixed to the base, a lead screw that is rotatably supported by the base and extends in the optical axis direction, and is screwed into a female screw portion of the lens frame, and a lead screw fixed to the base A drive motor having a parallel rotation shaft, a drive gear directly connected to the rotation shaft of the drive motor, a driven gear formed integrally with the lead screw, and a gear including a plurality of intermediate gears interposed between the drive gear and the driven gear When the drive motor rotates, the lead screw rotates through the gear train while moving the female screw portion in the optical axis direction, and the lens is moved together with the movement of the female screw portion. Those to move the frame in the optical axis direction is known (e.g., see Patent Document 2).

  However, in this lens driving device, since the lead screw is rotatably supported by the base, it is necessary to form a support portion with respect to the base, which leads to an increase in the size of the base and hence a reduction in the size of the device. Since the drive motor and the lead screw are both provided in the base, the above configuration is applied on the assumption that the drive motor and the lead screw are moved in the optical axis direction with respect to the base. It is difficult.

JP 2003-131111 A JP 2002-006197 A

  The present invention has been made in view of the above-described problems of the prior art. The object of the present invention is to simplify the structure in a configuration including a drive motor, a lead screw, and a nut (or a female screw). An object of the present invention is to provide a lens driving device capable of driving a lens frame in the optical axis direction while reducing the number of parts, reducing the size, and reducing the thickness.

The lens driving device of the present invention is held by a lens frame that holds a lens and is movably supported in the optical axis direction, a drive motor that exerts a driving force, a lead screw that extends in the optical axis direction, and a lens frame. A lens driving device comprising: a nut screwed to a lead screw; a driving gear directly connected to the driving motor; and a gear train including a driven gear directly connected to a region near one end of the lead screw, the driving motor It is seen including a support member that is integrally formed to support the lead screw rotatably, the support member, the other end or near region thereof extending therefrom and lead screw from one end surface of the housing of the drive motor Receiving a first support piece that rotatably supports the end face of the driven gear that extends from the other end face of the housing of the drive motor and is directly connected to the lead screw. Comprising a second support piece for supporting the line direction, it is characterized in that.
According to this configuration, when the drive motor rotates, the lead screw rotates through the gear train including the drive gear and the driven gear, and the lens frame moves in the optical axis direction together with the nut.
Here, since the lead screw is rotatably supported by a support member formed integrally with the drive motor, a portion for supporting the lead screw with respect to another component (a conventional base or the like) is formed. Compared with the case, the degree of freedom of arrangement of the drive motor and the lead screw is increased, and the structure can be simplified, and the apparatus can be made smaller or thinner.
In particular, the first support piece extending from one end surface of the drive motor rotatably supports the other end portion of the lead screw or the vicinity thereof, and the second support piece extending from the other end surface of the drive motor, For receiving the end face of the driven gear and supporting it in the axial direction (supporting in the thrust direction), at the time of assembly, for example, one end of the lead screw is brought into contact with another member (component) and supported rotatably. At the same time as the assembly of the drive motor, the lead screw can be assembled with the first support piece and the second support piece so as to be freely rotatable while restricting the movement in the axial direction. Can be achieved.

The said structure WHEREIN: The structure which is supporting the lead screw so that it may become parallel to the rotating shaft of a drive motor can be employ | adopted for the 1st support piece.
According to this configuration, since the lead screw is supported so as to be parallel to the rotation axis of the drive motor, compared to the case where the rotation axis of the drive motor and the lead screw are arranged orthogonally while using a worm gear or the like, It is possible to achieve downsizing and simplification of the gear train, downsizing of the apparatus by integrating parts, and the like.

In the above configuration, the second support piece may adopt a configuration in which the lead screw is rotatably supported in the vicinity of the driven gear.
According to this configuration, the first support piece extending from the one end surface of the drive motor rotatably supports the other end portion of the lead screw or the vicinity thereof, and extends from the other end surface of the drive motor. The two support pieces receive the end face of the driven gear and support it in the axial direction (support in the thrust direction) and support it rotatably, so that the lead screw is supported by the first support piece and the second support piece during assembly. By assembling the drive motor in a state where it is pivotably supported, the lead screw can be pivotally assembled while restricting movement in the axial direction, and the assembly work can be facilitated. it can.

The above configuration further includes a base and a rectilinear cylinder supported movably in the optical axis direction in front of the base. The rectilinear cylinder fixes the drive motor and supports the lens frame movably in the optical axis direction. The configuration can be adopted.
According to this configuration, when the drive motor and the lead screw move in the optical axis direction together with the straight cylinder that moves in the optical axis direction with respect to the base, and when the drive motor rotates, the gear train, the lead screw, and the nut are moved. Accordingly, the lens frame moves in the optical axis direction relative to the rectilinear cylinder.
In this way, in the configuration in which the drive motor, the lead screw, and the gear train move in the optical axis direction together with the rectilinear cylinder, the lead screw is rotatably supported by a support member formed integrally with the drive motor. Therefore, the drive motor and the lead screw can be arranged independently of the base, and the simplification of the structure, the miniaturization or thinning of the apparatus, and the like can be achieved.

In the above configuration, a straight advance cylinder cooperates with a second support piece supports one end of the lead screw rotatably while restricting movement in the axial direction of the lead screw, adopting the structure Can do.
According to this configuration, the lead screw can be rotatably supported (supported in the radial direction) by the first support piece and the rectilinear cylinder, and the lead screw is supported in the axial direction by the second support piece and the rectilinear cylinder. (Support in the thrust direction).

The said structure WHEREIN: The other end part of a lead screw can employ | adopt the structure currently formed so that it may enter in a base in the retracted state of a rectilinear advance cylinder.
According to this configuration, the apparatus can be made thinner by overlapping the lead screw and the base in the optical axis direction in the retracted state.

In the above-described configuration, the second lens frame that holds the lens and is supported so as to be movable in the optical axis direction is provided between the base and the rectilinear cylinder, and the other end of the lead screw is connected to the rectilinear cylinder and the second lens frame. In the retracted state, it is possible to adopt a configuration that is formed so as to extend backward through a part of the second lens frame.
According to this configuration, in the retracted state, the lead screw, the second lens frame, and the base are overlapped in the optical axis direction, so that the apparatus can be used despite including a plurality of lens frames arranged in the optical axis direction. It can be made thinner.

The said structure WHEREIN: The structure currently formed so that the 2nd support piece may serve also as the fixed piece which fixes a drive motor with respect to a rectilinear cylinder can be employ | adopted.
According to this configuration, since the second support piece also serves as a fixed piece of the drive motor, a dedicated fixed piece is not required, and the structure can be simplified, the apparatus can be reduced in size, and the thickness can be reduced.

  According to the lens driving device of the present invention having the above-described configuration, in a configuration including a drive motor, a lead screw, and a nut (or a female screw portion), the structure is simplified, the number of parts is reduced, the size is reduced, the thickness is reduced, and the like. In addition, a lens driving device suitable for being mounted on a thin digital camera, a thin silver salt film camera, or the like can be obtained.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 11 show an embodiment of a lens driving device according to the present invention. FIG. 1 is a front view of the device, FIG. 2 is a sectional view showing a driving mechanism of the device, and FIGS. FIG. 6 is a perspective view of the straight cylinder and the lens frame and the drive mechanism that form a part of the apparatus as seen from the rear, and FIG. 7 is a partial cross-sectional view in which a part of the drive mechanism is enlarged. 8 and 9 are a side view, a rear view, and a front view showing a drive motor forming a part of the apparatus, and FIGS. 10 and 11 are cross-sectional views of the apparatus showing a state where the lens is at the wide-angle end and the telephoto end.

  As shown in FIGS. 1 to 5, this apparatus is formed so as to demarcate a part of the base 10 as a base to which an imaging element PE such as a filter plate FP or CCD is attached, and is fixed to the base 10. The fixed cylinder 20, the rotating cylinder 30 supported so as to be able to rotate and advance straight in the optical axis direction L inside the fixed cylinder 20, and cannot rotate inside the rotating cylinder 30 and together with the rotating cylinder 30 in the optical axis direction L The first key cylinder 40 fitted so as to be linearly movable, the connecting cylinder 50 fitted so as to be non-rotatable inside the first key cylinder 40 and linearly movable in the optical axis direction L, and rotated inside the coupling cylinder 50 A first rectilinear cylinder 60 that is fitted in such a manner that it is impossible to travel straight in the optical axis direction L, a lens frame 70 that is supported so as to be movable relative to the first rectilinear cylinder 60 in the optical axis direction L, and a first rectilinear advance. Inside the cylinder 60, it can rotate freely and continuously. The cam cylinder 80 fitted so as to be linearly movable in the optical axis direction L together with the cylinder 50, and fitted inside the cam cylinder 80 so as not to be rotatable and linearly movable in the optical axis direction L together with the cam cylinder 80. Inside of the second key cylinder 90, the second rectilinear cylinder 100 and the first rectilinear cylinder 60 as the second lens frame that are fitted inside the second key cylinder 90 so as not to rotate and to be able to move straight in the optical axis direction L. A driving mechanism 110 that drives the lens frame 70 in the optical axis direction L, a driving mechanism 120 that is provided on the base (substrate 10) to rotationally drive the rotating cylinder 30, and the like.

  The substrate 10 is molded using a resin material, and as shown in FIGS. 1 to 5, an opening 11 through which light passes, and a recess formed behind the opening 11 to which the filter plate FP and the image sensor PE are attached. 12, a holding portion 13 for holding the drive mechanism 120, a through hole 14 for allowing a rear end portion 115c of a lead screw 115 to be described later to enter without contact, and a rear end portion of a guide shaft 117a to be described later to be inserted without contact. It is formed so as to be provided with a through hole 15 or the like. As shown in FIGS. 1 to 5, the holding portion 13 is formed so as to delimit a space for accommodating the gear train of the drive mechanism 120 in cooperation with a holding portion 21 of the fixed cylinder 20 described later.

The fixed cylinder 20 is molded using a resin material, and as shown in FIGS. 1 to 5, a holding part 21 that is joined to the holding part 13 of the base 10 and an axis parallel to the optical axis direction L. It is formed so as to include a cylindrical portion 22 or the like formed in a cylindrical shape having a heart.
As shown in FIGS. 2 and 3, the cylindrical portion 22 includes a cutout portion 22a cut out so as to allow a part of a gear 128, which will be described later, to enter the inside without contact, and a rotary cylinder 30 (follower pin, which will be described later). 31) Three cam grooves 22b formed on the inner peripheral surface to exert a cam action, a guide groove 22c for guiding the first key cylinder 40 (projection 41 described later) only in the optical axis direction L, and the like. Is formed.

  The rotating cylinder 30 is molded into a cylindrical shape having an axis parallel to the optical axis direction L using a resin material, and is inserted into the cam groove 22b of the fixed cylinder 20 as shown in FIGS. Three follower pins 31 arranged at equal intervals on the outer peripheral surface, and a tooth row (arc-shaped rack portion) 32 formed on the rear end side of the outer peripheral surface to mesh with a gear 128 described later are formed. . Then, the rotary cylinder 30 is rotated by a rotational driving force transmitted by the gear 128 and moves in the optical axis direction L while rotating.

The first key cylinder 40 is molded into a cylindrical shape having an axis parallel to the optical axis direction L using a resin material, and as shown in FIG. 3, a protrusion 41 inserted into the guide groove 22c of the fixed cylinder 20, Three guide grooves for receiving three follower pins 81 of a cam cylinder 80 (to be described later) and exerting a cam action in the optical axis direction L, and three guide grooves for receiving projections 52 of a connecting cylinder 50 (to be described later) and guiding them in the optical axis direction L 43 etc. are formed.
The first key cylinder 40 is nestably fitted inside the rotary cylinder 30 and is held by the fixed cylinder 20 so as not to rotate, and moves in the optical axis direction L together with the rotary cylinder 30. It has become.

  The connecting cylinder 50 is molded into a cylindrical shape having a center parallel to the optical axis direction L using a resin material. As shown in FIGS. 1 and 3, a follower pin 81 of a cam cylinder 80 described later is set to the optical axis L. Inserted into the guide groove 43 of the three arc-shaped long holes 51 formed so as to penetrate a predetermined length in the circumferential direction so as to freely receive a predetermined angular range in a vertical plane. Three guide grooves formed on the inner peripheral surface to receive three guides 52 formed so as to protrude outward in the radial direction as much as possible, and a projection 61b of the first rectilinear cylinder 60 described later to guide in the optical axis direction L. 53 etc. are formed. The connecting cylinder 50 is inserted in the first key cylinder 40 in a nested manner, and is held in a non-rotatable manner so as to move relative to the first key cylinder 40 in the optical axis direction L. It has become.

  The first rectilinear cylinder 60 is molded into a cylindrical shape having an axis parallel to the optical axis direction L by using a resin material, and as shown in FIGS. 1 and 3 to 6, an outer cylindrical portion 61, a lens described later. The cylindrical portion 71 of the frame 70 is formed to include an inner cylindrical portion 62 for reciprocally inserting the cylindrical portion 71 in the optical axis direction L, an outer cylindrical portion 61, a front end wall portion 63 that connects the inner cylindrical portion 62, and the like.

As shown in FIG. 3, the outer cylindrical portion 61 has a notch 61 a through which a follower pin 81 of a cam cylinder 80 to be described later passes radially outward without contact and a radial direction to be inserted into the guide groove 53 of the connecting cylinder 50. Three protrusions 61b formed to project outward, and three follower pins 61c that project inward in the radial direction so as to be inserted into an outer cam groove 82 of a cam cylinder 80, which will be described later, and are formed at equal intervals in the circumferential direction. Etc. are formed.
As shown in FIGS. 3 to 5, the inner cylindrical portion 62 is formed so that a cylindrical portion 71 of a lens frame 70 to be described later can be inserted movably in the optical axis direction L.

  As shown in FIGS. 3 to 7, the front end wall portion 63 has a boss portion 63a for fixing a drive motor 111 described later, a bearing hole 63b for rotatably supporting one end portion 115b of a lead screw 115 described later, A thrust receiving portion 63c formed on the end surface of the bearing hole 63b, a support shaft 63d that rotatably supports an intermediate gear 113 described later, fitting holes 63e and 63f for fitting guide shafts 117a and 117b described later, and a later-described A seat surface portion 63g for receiving one end of the coil spring 118, a fixing portion 63h for fixing a sensor 119 described later, and the like are formed.

The lens frame 70 is molded using a resin material, and is inserted into the inner cylindrical part 62 of the first rectilinear cylinder 60 and holds the lens G1, as shown in FIGS. Are connected to guide shafts 117a and 117b, which will be described later, and slidably connected to each other, a seat surface portion 74 formed on the connecting portion 72 and receiving the other end of a coil spring 118 described later, and a connecting portion 72. And a nut holding portion 76 that extends from the cylindrical portion 71 and holds a nut 116 that will be described later in a non-rotatable manner.
The lens frame 70 moves relative to the first rectilinear cylinder 60 in the optical axis direction L by a driving force of a driving mechanism 110 described later.

The drive mechanism 110 extends in the optical axis direction L so as to rotate integrally with the drive motor 111, the drive gear 112, the intermediate gear 113, the driven gear 114, and the driven gear 114, as shown in FIGS. The lead screw 115 formed in this manner, the nut 116 held by the nut holding portion 76 of the lens frame 70 in a state of being screwed to the lead screw 115, and the connecting portions 72 and 72 of the lens frame 70 are slidably fitted. Guide shafts 117a and 117b for guiding in the optical axis direction L, a coil spring 118 for urging the lens frame 70 rearward in the optical axis direction L, a sensor 119 for detecting the detected piece 75 of the lens frame 70, and the like. Yes.
The drive gear 112, the intermediate gear 113, and the driven gear 114 form a gear train that decelerates and transmits the drive force of the drive motor 111 to the lead screw 115.

  The drive motor 111 is, for example, a stepping motor. As shown in FIGS. 6 to 9, the drive motor 111 is a rotary shaft 111a having an axis S extending parallel to the optical axis direction L, a housing 111b defining an outer contour, and one of the housings 111b. A first support piece 111c as a support member coupled to the end surface, a second support piece 111d as a support member coupled to the other end surface of the housing 111b, and the like are provided.

The first support piece 111c is formed by bending a thin metal plate or the like, and as shown in FIGS. 6 to 9, the rear end portion (the other end portion) 115c of the lead screw 115 described later can be rotated. It is formed so as to have a bearing hole 111c ′ to be supported.
The second support piece 111d is formed of a thin metal plate, and as shown in FIGS. 6 to 9, defines a through hole into which a lead screw 115 described later is loosely inserted and receives the end face of the driven gear 114 to receive light. A receiving portion 111d ′ that is supported from the rear in the axial direction L and a fixing portion 111d ″ that defines a screw hole through which a screw fastened to the boss portion 63a of the first rectilinear cylinder 60 is passed.
As described above, the second support piece 111d is formed so as to also serve as a fixed piece (fixed portion 111d ″) for fixing the drive motor 111 to the first rectilinear cylinder 60, and thus a dedicated fixed piece is not required. Thus, simplification of the structure, miniaturization, thinning, etc. of the device can be achieved.

As shown in FIG. 7, the drive gear 112 is a spur gear and is directly connected to the rotation shaft 111 a of the drive motor 111.
As shown in FIG. 7, the intermediate gear 113 is a spur gear, and is rotatably supported by the support shaft 63 d of the first rectilinear cylinder 60 while being engaged with the drive gear 112.
As shown in FIG. 7, the driven gear 114 is a spur gear, is formed so as to rotate integrally with a region near the front end portion 115 a (one end portion) of the lead screw 115, and meshed with the intermediate gear 113. It is supported so that it can rotate freely.

  As shown in FIG. 7, the lead screw 115 is arranged to extend in the optical axis direction L, that is, to be parallel to the axial direction S of the rotation shaft 111 a of the drive motor 111, and is a male that meshes with the nut 116. A screw 115a, a front end 115b as one end rotatably fitted in the bearing hole 63b of the first rectilinear cylinder 60, a rear end 115c as the other end positioned rearward in the optical axis direction L, a first It is formed so as to include an annular end surface portion 115d that contacts the thrust receiving portion 63c of the rectilinear cylinder 60.

The lead screw 115 is passed from the front in the optical axis direction L through the through hole formed in the receiving portion 111d ′ of the second support piece 111d and through the bearing hole 111c ′ of the first support piece 111c. A region near the rear end portion 115c (the other end portion) is rotatably supported by the bearing hole 111c ′, and a front end portion 115b (one end portion) is rotatably inserted into the bearing hole 63b of the first rectilinear cylinder 60, The annular end surface portion 115d is brought into contact with the thrust receiving portion 63c, and the rear end surface of the driven gear 114 is brought into contact with the receiving portion 111d 'of the second support piece 111d, so that the rotation in the axial direction is restricted. It is designed to be freely supported.
Further, in the retracted state, the lead screw 115 passes through a through hole 102a formed in an extension portion 102 of the second rectilinear cylinder 100 described later, as shown in FIG. The through hole 14 is inserted.

  As described above, since the lead screw 115 is rotatably supported by the first support piece 111c formed integrally with the drive motor 111, the lead screw 115 can be compared with another component (a conventional base or the like). Compared with the case where a portion for supporting 115 is formed, the degree of freedom of arrangement of the drive motor 111 and the lead screw 115 is increased, and the structure can be simplified, and the apparatus can be made smaller or thinner.

  The lead screw 115 is rotatably supported in the vicinity of the other end 115 c by a first support piece 111 c extending from one end surface of the drive motor 111, and extends from the other end surface of the drive motor 111. Since the rear end surface of the driven gear 114 is supported by the support piece 111d so that the rearward movement in the axial direction is restricted (supported in the thrust direction), the front end portion of the lead screw 115 is assembled during assembly. (One end portion) 115b is abutted against the thrust receiving portion 63c of the first rectilinear cylinder 60 so as to be rotatably fitted in the bearing hole 63b. Simultaneously with the assembly of the drive motor 111, the first support piece 111c And the second support piece 111d allows the lead screw 115 to be pivotably assembled while restricting movement in the axial direction, thereby facilitating the assembling work. Can.

  Further, the rear end portion (the other end portion) 115c of the lead screw 115 is a part of the second rectilinear barrel 100 (the through hole 102a of the extension portion 102) in the retracted state of the first rectilinear barrel 60 and the second rectilinear barrel 100. ) And extend rearward so as to enter the through hole 14 of the substrate 10, that is, in the retracted state, the lead screw 115, the second rectilinear cylinder 100 and the substrate 10 are moved in the optical axis direction L. Therefore, the apparatus can be made thinner even though it includes two rectilinear cylinders 60 and 100 arranged in the optical axis direction L.

The cam cylinder 80 is molded into a cylindrical shape having a shaft center parallel to the optical axis direction L using a resin material, and as shown in FIG. 3, the notched portion 61a of the first rectilinear cylinder 60 (outer cylindrical portion 61). The three follower pins 81 inserted into the penetrating cam 42 of the first key cylinder 40 and the follower pin 61c of the first rectilinear cylinder 60 are received through the arc-shaped elongated hole 51 of the connecting cylinder 50 and have a cam action 3 in the optical axis direction L. Two outer cam grooves 82 and three inner cam grooves 83 that receive a follower pin 103 of a second rectilinear cylinder 100 to be described later and exert a cam action in the optical axis direction L are formed.
The cam cylinder 80 is inserted in the inner cylindrical shape of the outer cylindrical portion 61 and moves in the optical axis direction L together with the connecting cylinder 50 and is rotated by receiving a cam action by the first key cylinder 40. The cam action is exerted in the optical axis direction L on the follower pin 61c of the first rectilinear cylinder 60 and the follower pin 103 of the second rectilinear cylinder 100.

The second key cylinder 90 is formed of a resin material into a cylindrical shape having an axis parallel to the optical axis direction L, and is connected to the connection cylinder 50 in a non-rotatable manner as shown in FIG. 91, three guide slits 92 for guiding the follower pin 103 of the second rectilinear cylinder 100 only in the optical axis direction L, and the like.
The second key cylinder 90 is fitted inside the cam cylinder 80 in a nested manner, is held non-rotatable, moves in the optical axis direction L together with the connecting cylinder 50, and rotates the second rectilinear cylinder 100. Is allowed to move in the optical axis direction L.

The second rectilinear cylinder 100 is molded into a cylindrical shape having an axis parallel to the optical axis direction L using a resin material, and as shown in FIGS. 3 to 5, a cylindrical portion 101 that holds a lens G2, and a cylindrical portion An extension portion 102 extending in the radial direction from 101, 3 protruding outward in the radial direction from the extension portion 102 so as to be inserted into the inner cam groove 83 of the cam cylinder 80, and formed at equal intervals in the circumferential direction 3 It is formed so as to include two follower pins 103 and the like.
The second rectilinear cylinder 100 is moved in the optical axis direction L by receiving a cam action by the cam cylinder 80 while being restricted from being rotated by the second key cylinder 90.

  As shown in FIG. 2, the drive mechanism 120 includes a DC motor 121 fixed to the base 10, a drive gear 122 directly connected to the DC motor 121, a gear 123 a meshing with the drive gear 122, and a coaxial with the gear 123 a. The worm gear 123b formed on the worm wheel 123a, the worm wheel 124a meshing with the worm gear 123b, the gear 124b integrally formed coaxially with the worm wheel 124a, the gear 125 meshing with the gear 124b, the gear 126a meshing with the gear 125, and the gear 126a. And a gear 127 that meshes with the gear 126b, and a gear 128 that meshes with the tooth row (arc-shaped rack portion) 32 of the rotating cylinder 30 at the same time. .

The driving operation of the above apparatus will be described. As shown in FIG. 3, when the DC motor 121 rotates from the retracted position, the rotating cylinder 30 rotates through the gear train and is fed forward in the optical axis direction L. .
Then, due to the action of the first key cylinder 40 and the connecting cylinder 50, the cam cylinder 80 moves and rotates in the optical axis direction L, exerts a cam action on the first rectilinear cylinder 60 and the second rectilinear cylinder 100, and the first The rectilinear cylinder 60 and the second rectilinear cylinder 100 move relative to the optical axis direction L, move from the wide-angle end position shown in FIG. 11 to the telephoto end position shown in FIG. 12, and perform a zooming operation.

Further, when the drive motor 111 rotates together with this zooming operation, the lead screw 115 rotates via the gear train (the drive gear 112, the intermediate gear 113, the driven gear 114), and the lens frame 70 is moved together with the nut 116. The zoom lens is moved to a desired position in the optical axis direction L, and a zooming operation and a focusing operation are performed.
That is, the drive mechanism 110 including the drive motor 111, the lead screw 115, and the gear train (the drive gear 112, the intermediate gear 113, and the driven gear 114) together with the first rectilinear cylinder 60 that moves in the optical axis direction L with respect to the substrate 10. Is moved in the optical axis direction L, the movement of the lead screw 115 in the axial direction is restricted by the support members (first support piece 111c, second support piece 111d) formed integrally with the drive motor 111. However, since the drive motor 111 and the lead screw 115 can be arranged without being constrained by the substrate 10, the structure can be simplified, and the apparatus can be made smaller or thinner. can do.

On the other hand, when the DC motor 121 rotates in the reverse direction, the rotating cylinder 30 is retracted toward the rear in the optical axis direction L while rotating in the reverse direction via the gear train, and in conjunction with this, the first rectilinear cylinder 60 and the first The two straight cylinders 100 are also retracted and returned to the original retracted position.
In this retracted state, the rear end portion 115c of the lead screw 115 passes through a part of the second rectilinear cylinder 100 (the through hole 102a of the extending portion 102) and enters the through hole 14 of the substrate 10, that is, In the optical axis direction L, the second straight cylinder 100 and the base 10 are overlapped. Thereby, the apparatus can be thinned in the retracted state.

FIG. 12 shows another embodiment of the lens driving device according to the present invention. The same reference numerals are given to the same components as those of the above-described embodiment, and the description thereof is omitted.
In this device, as shown in FIG. 12, the second support piece 111 d supports the lead screw 115 so as to be rotatable in the vicinity of the driven gear 114.
That is, as shown in FIG. 12, the second support piece 111d is in contact with the rear end surface of the driven gear 114 and rotatably supports the lead screw 115 'in the region near the driven gear 114. ′ Is defined. Further, the lead screw 115 ′ is formed such that a front end portion 115 b ′ thereof is in contact with a thrust receiving portion 63 c ′ formed on the front wall portion 63 of the first rectilinear cylinder 60.

  According to this, the first support piece 111c extending from one end surface of the drive motor 111 rotatably supports the vicinity of the rear end portion (the other end portion) 115c of the lead screw 115 ′ and is driven. The second support piece 111d extending from the other end surface of the motor 111 receives the rear end surface of the driven gear 114, supports it in the axial direction (supports in the thrust direction), and supports it rotatably. The lead screw 115 ′ is rotatably supported by the first support piece 111c and the second support piece 111d, and the lead motor 115 is fixed to the first rectilinear cylinder 60 (front wall portion 63), thereby the lead. The screw 115 ′ can be rotatably assembled while restricting movement in the axial direction. Thereby, simplification of an assembling work can be achieved.

In the above-described embodiment, the case where the configuration of the present invention is applied to the drive mechanism 110 that moves together with the first rectilinear cylinder 60 that moves in the optical axis direction L is shown, but the present invention is not limited to this. The configuration of the present invention may be employed to drive the lens frame in the optical axis direction with respect to the base (substrate 10).
In the above embodiment, the case where the present invention is adopted in the configuration including the two rectilinear cylinders 60 and 70 is shown, but the present invention is not limited to this, and the configuration including three or more rectilinear cylinders is not limited to this. The invention may be applied.

  As described above, the lens driving device of the present invention achieves simplification of the structure, reduction in the number of parts, reduction in size, reduction in thickness, and the like in a configuration including a drive motor, a lead screw, and a nut (or a female screw). Therefore, it can be applied as a lens driving device such as a thin digital camera and a thin silver salt film camera, and is not limited to a camera, but can also be used as a lens driving device for other lens optical systems that are desired to be thin. Useful.

It is a front view which shows one Embodiment of the lens drive device which concerns on this invention. It is sectional drawing in a surface perpendicular | vertical to the optical axis which shows one Embodiment of the lens drive device based on this invention. It is sectional drawing in the surface containing the optical axis which shows one Embodiment of the lens drive device which concerns on this invention. It is an expanded sectional view in the field containing the optical axis which shows one embodiment of the lens drive concerning the present invention. It is an expanded sectional view in the field containing the optical axis which shows one embodiment of the lens drive concerning the present invention. It is the perspective view which looked at the inner side of the 1st rectilinear advance cylinder which makes a part of lens drive device from back. FIG. 7 is a partial cross-sectional view of the lens driving device shown in FIGS. 1 to 6. It is a side view of the drive motor which makes a part of lens drive device shown in Drawing 1 thru / or Drawing 6. FIG. 7 shows a drive motor that forms part of the lens driving device shown in FIGS. 1 to 6, wherein (a) is a rear view seen from the rear in the optical axis direction, and (b) is seen from the front in the optical axis direction. It is a front view. FIG. 7 is a cross-sectional view showing a state where the lens is at a wide angle end in the lens driving device shown in FIGS. 1 to 6. FIG. 7 is a cross-sectional view showing a state where the lens is at the telephoto end in the lens driving device shown in FIGS. 1 to 6. It is a fragmentary sectional view which shows other embodiment of the lens drive device based on this invention.

Explanation of symbols

L Optical axis direction G1, G2 Lens 10 Substrate (base)
DESCRIPTION OF SYMBOLS 11 Opening part 12 Concave part 13 Holding | maintenance part 14,15 Through-hole 20 Fixed cylinder 22 Cylindrical part 22a Notch part 22b Cam groove 22c Guide groove 30 Rotating cylinder 31 Follower pin 32 Teeth row 40 1st key cylinder 41 Protrusion 42 Through cam 43 Guide groove 50 connecting cylinder 51 arc-shaped long hole 52 protrusion 53 guide groove 60 first straight cylinder 61 outer cylindrical part 61a notch 61b follower 61c follower pin 62 inner cylindrical part 70 lens frame 71 cylindrical part 72, 73 connecting part 74 seat surface part 75 to be detected Piece 76 Nut holding portion 80 Cam cylinder 81 Follower pin 82 Outer cam groove 83 Inner cam groove 90 Second key cylinder 91 Connection piece 92 Guide slit 100 Second rectilinear cylinder (second lens frame)
101 cylindrical portion 102 extending portion 102a through hole 103 follower pin 110 drive mechanism 111 drive motor 111a rotating shaft 111b housing 111c first support piece (support member)
111c ′ bearing hole 111d second support piece (support member)
111d ′ receiving portion 111d ″ fixing portion (fixing piece)
111 d ″ ″ Bearing hole 112 Drive gear 113 Intermediate gear 114 Driven gear 115, 115 ′ Lead screw 115 a Male thread portion 115 b, 115 b ′ Front end portion (one end portion)
115c Rear end (other end)
116 Nuts 117a, 117b Guide shaft 118 Coil spring 119 Sensor 120 Drive mechanism

Claims (8)

A lens frame that holds the lens and is supported so as to be movable in the optical axis direction, a drive motor that exerts a driving force, a lead screw that extends in the optical axis direction, and a screw that is held by the lens frame and screwed into the lead screw A lens driving device including a gear train including a nut, a drive gear directly connected to the drive motor, and a driven gear directly connected to a region close to one end of the lead screw;
The drive motor, saw including a support member that is integrally formed so as to support the lead screw rotatably,
The support member extends from one end surface of the housing of the drive motor and rotatably supports the other end portion of the lead screw or the vicinity thereof, and the other end surface of the drive motor housing. A second support piece that extends and receives the end face of the driven gear directly connected to the lead screw and supports it in the axial direction;
A lens driving device. The first support piece supports the lead screw so as to be parallel to the rotation axis of the drive motor.
The lens driving device according to claim 1 . The second support piece rotatably supports the lead screw in a region near the driven gear;
The lens driving device according to claim 1 or 2, wherein And further includes a base and a straight cylinder supported so as to be movable in the optical axis direction in front of the base,
The rectilinear cylinder fixes the drive motor and supports the lens frame movably in the optical axis direction.
Claims 1, wherein the lens driving apparatus according to 3 any one. Before SL rectilinear tube serves to restrict the movement of and the cooperation with the second support piece to the axial direction of the lead screw, and supports one end of the lead screw rotatably,
The lens driving device according to claim 4 . The other end of the lead screw is formed so as to enter the base in the retracted state of the rectilinear cylinder.
The lens driving device according to claim 4 or 5 , wherein A second lens frame that holds the lens and is supported so as to be movable in the direction of the optical axis between the base and the rectilinear cylinder;
The other end of the lead screw is formed so as to extend rearward through a part of the second lens frame in the retracted state of the rectilinear cylinder and the second lens frame.
The lens driving device according to claim 4 , wherein the lens driving device is a lens driving device. The second support piece is formed so as to serve as a fixed piece for fixing the drive motor to the rectilinear cylinder.
The lens driving device according to claim 1 , wherein the lens driving device is a lens driving device.

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