JP2008112017A - Drive device of lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent mutual biting of gears and damage of teeth or the like in a lens barrel drive device equipped with a gear train. <P>SOLUTION: The lens barrel drive device is equipped with: a base 10; a rotating member 30 rotating so as to drive a lens frame holding a lens in an optical axis direction; a DC motor 101 fixed on the base 10; the gear trains 102 to 111 transmitting the rotational driving force of the DC motor to the rotating member 30; and a plurality of spindles 112 to 116 supporting the gears included in the gear trains 102 to 111 so as to freely turn respectively. The plurality of spindles 112 to 116 include movable spindles 113 and 114 held on the base so as to be biased according to force exerted on the gear. Thus, when a movable member such as the rotating member moves excessively to exceed an allowable moving range and overload is applied to the gears of the gear train, the movable spindles 113 and 114 are biased to release the overload. Thus, the mutual biting of the gears and the damage of the teeth or the like are prevented. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a driving device for a lens barrel mounted on a digital camera, a silver salt film camera, or the like, and more particularly to a gear train for transmitting a rotational driving force of a driving source to the lens barrel. The present invention relates to a driving device for a lens barrel including the above.

  The lens barrel driving device includes a DC motor as a driving source, a worm gear directly connected to the rotating shaft of the DC motor, a worm wheel meshing with the worm gear, a second worm gear formed integrally with the worm wheel, A second worm wheel meshing with the second worm gear, a spur gear integrally formed coaxially with the second worm wheel, a cylindrical second spur gear meshing with the spur gear, and a second spur gear A cylindrical cam having an arcuate tooth row that meshes with the outer peripheral surface is provided, and the driving force of the DC motor is transmitted to the cylindrical cam through the gear train described above. A lens barrel (lens) that is relatively extended in the optical axis direction is known (for example, see Patent Document 1).

  In this drive device, in order to control the amount of extension of the lens (lens cylinder), a position detection sensor for detecting the initial position and a rotation sensor such as an encoder for detecting the amount of extension are provided and output by these sensors. Based on the signal, the energization to the DC motor is controlled, and the lens is extended to a desired position for positioning.

However, in this drive device, when checking the operation after assembling the device in an assembly line or the like, if the DC motor is energized with insufficient sensor connection, a movable member such as a cylindrical cam or a lens tube However, there is a case where it moves beyond the allowable operating range and collides with surrounding members.
Due to such a collision, the combined torque of the inertia torque generated by the rotation of the rotating shaft of the DC motor and the gear train and the starting torque of the DC motor acts as a shearing force on the teeth of the gear train, and damage of the teeth, There is a risk of causing (gear) biting (locking) between the gears.

  In order to cope with this problem, measures such as changing the DC motor to a low speed type, increasing the strength of the gear train teeth, providing a slip mechanism in the gear train, or setting a large advance angle of the worm gear are taken. , The feeding speed becomes slow (the time required for feeding becomes long), the device becomes large, the deceleration efficiency decreases with the review of the advance angle of the worm gear, or the number of parts increases (cost increases), etc. This will incur the disadvantages.

JP 2004-354874 A

  The present invention has been made in view of the above problems of the prior art, and its object is to simplify the structure, reduce the number of parts, ease of manufacturing, downsizing, cost reduction, etc. A lens mirror that can prevent biting (locking) of gears (gears), damage to teeth, etc., and reliably guarantee the expected function even when the movable member moves excessively beyond the allowable range. The object is to provide a driving device for the trunk.

The lens barrel driving apparatus according to the present invention includes a base, a rotating member that rotates to drive a lens frame that holds the lens in the optical axis direction, a driving source fixed to the base, and a rotational driving force of the driving source. And a plurality of support shafts rotatably supporting the gears included in the gear train, wherein the plurality of support shafts includes: It includes a movable support shaft that is held on the base so as to be capable of being biased according to the force received by the gear.
According to this configuration, the driving force is transmitted from the driving source to the rotating member via the gear train, and the lens frame (lens) is moved in the optical axis direction as the rotating member rotates. In this driving operation, when a movable member such as a rotating member or a lens frame interlocking with the rotating member is excessively moved to a position beyond an allowable moving range, the gears of the gear train are overloaded along with the excessive movement ( When an unreasonable force, for example, a meshing force exceeding a predetermined level, is received, the movable support shaft is biased according to the force, and the overload is released.
Thereby, it is possible to prevent biting between gears, breakage of teeth, and the like, and it is possible to easily return to a normal state by starting the drive source.
In addition, since only a part of the plurality of support shafts is a movable support shaft, it is possible to achieve simplification of the structure, ease of manufacture, size reduction, cost reduction, and the like.

In the above configuration, the plurality of support shafts include four or more support shafts, and the four or more support shafts support two gears that mesh with each other and are held so as to be capable of being biased according to the force received by the gears. A configuration including a movable support shaft can be employed.
According to this configuration, since the two adjacent support shafts that support the gears meshing with each other are formed as movable support shafts that can be biased, the overload (reasonable) that the gear receives while suppressing the amount of each bias. Power) can be released (released) efficiently. Thereby, smooth operation | movement can be ensured, maintaining the preferable meshing state of gears.

In the above configuration, the gear supported by the movable support shaft may be a spur gear.
According to this configuration, since the gear is a spur gear, the movable support shaft is surely biased while preventing the gear from moving in the axial direction, and overload (unreasonable force) applied between the gears can be easily performed. And it can be released (released) reliably.

In the above configuration, the movable support shaft is held in a cantilever shape so that one end is fixed to the base and the other end forms a free end that can be biased in a direction substantially perpendicular to the axis. A configuration can be employed.
According to this configuration, the movable support shaft can release an overload (unreasonable force) because its free end (other end) bends in a direction substantially perpendicular to the axis, and the number of parts can be reduced. A structure that can be biased can be easily formed without causing an increase.

In the above configuration, the movable support shaft adopts a configuration in which one end is fixed to the base and the other end is held on the base via an elastic member so as to be able to be deflected in a direction substantially perpendicular to the axis. be able to.
According to this configuration, the movable support shaft is held in a doubly supported manner, one end portion is firmly fixed (rigid), and the other end portion is held so as to be able to be biased via an elastic member (for example, a rubber member). Therefore, while suppressing unnecessary vibration and the like on the other end side, when a force exceeding a predetermined level is applied, the other end portion bends in a direction substantially perpendicular to the axis while elastically deforming the elastic member. Thus, overload (unreasonable force) can be released.

In the above configuration, the movable support shaft may have a configuration in which one end portion and the other end portion are held on the base via an elastic member so as to be deflectable in a direction substantially perpendicular to the axis.
According to this configuration, the movable support shaft is held in a cantilevered manner, and both end portions (one end portion and the other end portion) thereof are held so as to be able to be biased via the elastic member (for example, a rubber member). Therefore, while suppressing unnecessary vibrations and the like of the movable support shaft, when a force exceeding a predetermined level is applied, the movable support shaft moves in a direction substantially perpendicular to the axis while elastically deforming the elastic members on both sides. Therefore, the overload (unreasonable force) can be released, and the movable support shaft is deflected without bending, so that the gear can be translated without tilting and the optimum meshing angle can be maintained. .

In the above-described configuration, the movable support shaft may be configured to be fitted in the through hole of the gear so as to rotatably support the gear.
According to this configuration, after the movable support shaft and the gear are formed as separate members, the movable support shaft is inserted into the through hole to support the gear rotatably. Assembling can be easily performed when holding through the elastic member, and when both ends of the movable support shaft are held through the elastic member as described above (the movable support shaft is not bent). In order to move in parallel, the movable support shaft can support the gear so that it can rotate more smoothly without sticking in the through hole.

In the above configuration, the gear train can adopt a configuration including a worm gear and a worm wheel.
According to this configuration, in the gear train that can only transmit the driving force from the worm gear to the worm wheel, if the gear on the downstream side of the gear train receives an overload (unreasonable meshing force), the bite is bitten. Although there is a risk of locking, the provision of the movable support shaft as described above makes it possible to achieve the desired function without causing biting (locking) or breakage even in the gear train including the worm gear and the worm wheel. Can be secured, and the rotational force can be transmitted smoothly.

  According to the present invention having the above-described configuration, when the movable member is excessively moved beyond the allowable range while achieving the simplification of the structure, the reduction of the number of parts, the ease of manufacturing, the miniaturization, the cost reduction, and the like. However, it is possible to obtain a lens barrel drive device that can prevent biting (locking) of gears (gears), damage to teeth, and the like, and reliably guarantee the expected function.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
1 to 5 show an embodiment of a lens barrel driving apparatus according to the present invention. FIG. 1 is a front view of the apparatus, and FIG. 2 is a cross-sectional view of the apparatus including an optical axis. 3 to 5 are partial sectional views of the apparatus.

  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 as a rotating member 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 light together with the rotating cylinder 30. A first key cylinder 40 fitted so as to be linearly movable in the axial direction L; a connecting cylinder 50 which is non-rotatable inside the first key cylinder 40 and is fitted so as to be linearly movable in the optical axis direction L; The first rectilinear cylinder 60 as a lens frame fitted so as to be unrotatable on the inside and linearly movable in the optical axis direction L. The optical axis is rotatable inside the first rectilinear cylinder 60 and together with the connecting cylinder 50. Mated so that it can go straight in direction L The cam cylinder 70, the second key cylinder 80 fitted in such a manner that the cam cylinder 70 cannot rotate inside the cam cylinder 70 and can move straight in the optical axis direction L together with the cam cylinder 70, and rotates inside the second key cylinder 80. The second rectilinear cylinder 90 as a lens frame fitted in such a manner as to be impossible to move straight in the optical axis direction L, and the first drive mechanism 100 and the first rectilinear cylinder 60 provided on the base for rotationally driving the rotary cylinder 30. A second drive mechanism 120 provided inside is provided.

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 and a holding portion 13 for holding the first drive mechanism 100 and the like.
As shown in FIGS. 3 to 5, the holding portion 13 is formed so as to delimit a space for accommodating a gear train of the first drive mechanism 100 described later in cooperation with a holding portion 21 of the fixed cylinder 20 described later. Has been.

  As shown in FIGS. 3 to 5, the holding portion 13 includes a mounting portion 13 a of a DC motor 101 described later, a bearing hole 13 b that rotatably supports shafts 103 a and 117 a described later, a fixed shaft 112 described later, Fitting holes 13c, 13d, and 13e for fitting and firmly fixing one end portions 112a, 115a, and 116a of 115 and 116, and one end portions 113a and 114a of movable support shafts 113 and 114 to be described later, respectively. It is formed so as to have fitting holes 13f, 13g and the like that are firmly fixed.

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. 3 to 5, the holding portion 21 has fitting holes 21c and 21d for fitting and firmly fixing the other end portions 112b, 115b, and 116b of fixed support shafts 112, 115, and 116, which will be described later. , 21e, recesses 21f and 21g for receiving the other end portions 113b and 114b of the movable support shafts 113 and 114, which will be described later, as free ends (without contact with the outer peripheral surface), and mounting recesses for mounting the sensor 118 to be described later 21h etc. are formed.
That is, the holding portion 21 of the fixed cylinder 20 forms a base for fixing or holding the first drive mechanism 100 in cooperation with the holding portion 13 of the substrate 10.

  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 111, 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.

  As shown in FIGS. 2 to 5, the first drive mechanism 100 is directly connected to the DC motor 101 as a drive source fixed to the attachment portion 13 a of the base 10 (the holding portion 13) and the rotary shaft 101 a of the DC motor 101. Drive gear 102, a gear 103 meshing with the drive gear 102, a worm gear 104 integrally formed on the same axis (support shaft 13a) as the gear 103, a worm wheel 105 meshing with the worm gear 104, and coaxial with the worm wheel 105 A gear 106 integrally formed with the gear 106, a gear 108 meshed with the gear 107, a gear 109 integrally formed coaxially with the gear 108, a gear 110 meshed with the gear 109, and a gear A gear 111 and a gear 103 which mesh with a tooth row (arc-shaped rack portion) 32 of the rotating cylinder 30 which will be described later simultaneously with the gear 110 The integrally formed support shaft 103a, the fixed support shaft 112 that rotatably supports the worm wheel 105, and the gear 106, the movable support shaft 113 that rotatably supports the gear 107, and the gears 108 and 109 are rotatable. A movable support shaft 114 that supports the gear 110, a fixed support shaft 115 that rotatably supports the gear 110, a fixed support shaft 116 that rotatably supports the gear 111, and a blade that is directly connected to the end of the worm gear 104 and rotates together. It is formed by a sensor 118 or the like that detects the rotation of the wheel 117 and the impeller 117.

  Here, the rotary cylinder 30 while reducing the rotational driving force of the DC motor 101 by the driving gear 102, the gear 103 and the worm gear 104, the worm wheel 105 and the gear 106, the gear 107, the gear 108 and the gear 109, the gear 110 and the gear 111. Is formed.

  As shown in FIGS. 3 and 4, the gear 103 and the worm gear 104 are rotatably supported with respect to the bearing hole 13 b of the holding portion 13 by a support shaft 103 a and a support shaft 117 a. The gear 103 is formed as a spur gear.

  As shown in FIG. 5, the worm wheel 105 and the gear 106 are formed so as to have a through hole 105 a and are rotatably supported by a fixed support shaft 112. Here, the fixed support shaft 112 has one end 112 a firmly fitted in the fitting hole 13 c of the holding portion 13 and the other end 112 b is firmly fitted in the fitting hole 21 c of the holding portion 21 to be held. It is firmly fixed to the parts 13 and 21 so as not to move in either direction. The gear 106 is formed as a spur gear.

As shown in FIG. 5, the gear 107 is formed to have a through hole 107 a and is rotatably supported by a movable support shaft 113. Here, the movable support shaft 113 has one end portion 113a firmly fitted in the fitting hole 13f of the holding portion 13 and the other end portion 113b in the concave portion 21f of the holding portion 21 (the outer peripheral surface of the other end portion 113b is non-exposed). Contained in contact). The gear 107 is formed as a spur gear.
That is, the movable support shaft 113 is held in a cantilever shape so that the other end 113b becomes a free end. Therefore, when the gear 107 receives an overload (unreasonable force), the movable support shaft 113 can be deflected by bending the other end 113b in a direction substantially perpendicular to the axis. Thereby, the overload received by the gear 107 can be easily released (released).

As shown in FIG. 5, the gears 108 and 109 are formed so as to have a through hole 108 a and are rotatably supported by a movable support shaft 114. Here, the movable support shaft 114 has one end 114 a firmly fitted in the fitting hole 13 g of the holding portion 13, and the other end 114 b is in the concave portion 21 g of the holding portion 21 (the outer peripheral surface of the other end 114 b is not Contained in contact). The gears 108 and 109 are formed as spur gears.
That is, the movable support shaft 114 is held in a cantilever shape so that the other end 114b becomes a free end. Therefore, when the gear 108 or the gear 109 receives an overload (unreasonable force), the movable support shaft 114 can be deflected by bending the other end portion 114b in a direction substantially perpendicular to the axis. Yes. Thereby, the overload received by the gear 108 or the gear 109 can be easily released (released).

  As shown in FIG. 5, the gear 110 is formed to have a through hole 110 a and is rotatably supported by a fixed support shaft 115. Here, one end 115a of the fixed support shaft 115 is firmly fitted into the fitting hole 13d of the holding portion 13, and the other end 115b is firmly fitted into the fitting hole 21d of the holding portion 21 to be held. It is firmly fixed to the parts 13 and 21 so as not to move in either direction. The gear 110 is formed as a spur gear.

  As shown in FIG. 5, the gear 111 is formed so as to have a through hole 111 a and is rotatably supported by a fixed support shaft 116. Here, the fixed support shaft 116 has one end 116 a firmly fitted into the fitting hole 13 e of the holding portion 13, and the other end 116 b firmly fitted into the fitting hole 21 e of the holding portion 21. It is firmly fixed to the parts 13 and 21 so as not to move in either direction. The gear 111 is formed as a spur gear that has a long cylindrical shape in the axial direction.

According to the gear train having the above-described configuration, a movable member (a member that rotates or linearly moves) such as the rotating cylinder 30, the first rectilinear cylinder 60, and the second rectilinear cylinder 90, which will be described later, is located beyond a permissible moving range. When the gears of the gear train are overloaded (unreasonable force, for example, a meshing force exceeding a predetermined level), the movable support shafts 113 and 114 are displaced according to the force. And act to release the overload.
Thereby, it is possible to prevent biting between gears, breakage of teeth, and the like, and it is possible to easily return to a normal state by starting the DC motor 101.

Here, among the five support shafts 112, 113, 114, 115, and 116, two adjacent support shafts 113 and 114 that support gears 107 and 108 that mesh with each other are formed as movable support shafts that can be deflected. Therefore, the overload (unreasonable force) received by the gear 107 or the gear 108 can be efficiently released (released) while suppressing the amount of deviation. Thereby, smooth operation | movement can be ensured, maintaining the preferable meshing state of gears.
Further, here, a part of the plurality of support shafts are made movable support shafts 113 and 114, and the movable support shafts 113 and 114 are held in a cantilevered manner, so that they can be biased without increasing the number of parts. Therefore, it is possible to easily form a simple structure, and to achieve simplification of the structure, ease of manufacturing, miniaturization, cost reduction, and the like.
Further, since the gears 107 and 108 supported by the movable support shafts 113 and 114 are spur gears, the movable support shafts 113 and 114 are surely biased and applied between the gears while preventing the gears from moving in the axial direction. Overload (unreasonable force) can be easily and reliably released (released).

  In addition, since the gear train includes the worm gear 104 and the worm wheel 105, only the driving force can be transmitted from the worm gear 104 to the worm wheel 105, and the gear on the downstream side of the gear train is overloaded (unreasonably meshed). Force), it may bite and lock, but by providing the movable support shafts 113 and 114 as described above, even a gear train including the worm gear 104 and the worm wheel 105 can be used. The desired function can be ensured and the rotational force can be transmitted smoothly without causing biting (locking) or breakage.

As shown in FIGS. 3 and 4, the impeller 117 is directly connected to the worm gear 104 at one end and is rotatably supported by a support shaft 117 a at the other end, and is detected by a sensor 118. A plurality of blades 117b are integrally provided.
The sensor 118 is a transmissive optical sensor including a light projecting element that emits detection light and a light receiving element that receives light, and is attached to an attachment recess 21 h of the holding part 21 as shown in FIG. 4. The sensor 118 detects information about rotation by detecting the blade 117b of the impeller 117.

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 the gear 111 are formed.
The rotating cylinder 30 is rotated by the gear 111 and is rotated 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. 2, a protrusion 41 inserted into the guide groove 22c of the fixed cylinder 20, Three guide grooves for receiving three follower pins 71 of a cam cylinder 70 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 an axis parallel to the optical axis direction L by using a resin material, and a follower pin 71 of a cam cylinder 70 described later is placed on the optical axis L as shown in FIGS. 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 using a resin material, and as shown in FIG. 1 and FIG. The inner cylindrical portion 62 and the like are supported so as to be relatively movable in the optical axis direction L and hold the lens G1.
The outer cylindrical portion 61 is formed so as to protrude radially outward so as to be inserted into a notch portion 61a through which a follower pin 71 of a cam cylinder 70, which will be described later, passes in a radially outward direction without contact, and a guide groove 53 of the connecting cylinder 50. The three protrusions 61b, three follower pins 61c that protrude radially inward and are equally spaced in the circumferential direction so as to be inserted into an outer cam groove 72 of the cam cylinder 70, which will be described later, are formed. ing. Further, the outer cylindrical portion 61 holds a second drive mechanism 120 described later so as to move integrally in the optical axis direction L.
As shown in FIG. 2, the inner cylindrical portion 62 holds the lens G <b> 1 and is supported so as to be movable in the optical axis direction L with respect to the outer cylindrical portion 61. The inner cylindrical portion 62 is moved relative to the outer cylindrical portion 61 in the optical axis direction L by the driving force of the second drive mechanism 120.

  As shown in FIG. 2, the second drive mechanism 120 includes a nut 121 fixed to a part of the inner cylindrical portion 62, a lead screw 122 screwed into the nut 121, a gear 123 that rotates integrally with the lead screw 122, A drive gear 124 that meshes with the gear 123 via an intermediate gear (not shown), a stepping motor 125 that rotates the drive gear 124, and the like are formed.

The cam cylinder 70 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. 2, the notched portion 61a of the first rectilinear cylinder 60 (outer cylindrical portion 61). The three follower pins 71 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 72 and three inner cam grooves 73 that receive a follower pin 93 of a second rectilinear cylinder 90 to be described later and exert a cam action in the optical axis direction L are formed.
The cam cylinder 70 is nested in 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 61 c of the first rectilinear cylinder 60 and the follower pin 93 of the second rectilinear cylinder 90.

The second key cylinder 80 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. 81, three guide slits 82 for guiding the follower pin 93 of the second rectilinear cylinder 90 only in the optical axis direction L, and the like.
The second key cylinder 80 is fitted inside the cam cylinder 70 in a nested manner, is held unrotatable, moves in the optical axis direction L together with the connecting cylinder 50, and rotates the second rectilinear cylinder 90. Is allowed to move in the optical axis direction L.

The second rectilinear cylinder 90 is molded into a cylindrical shape having a central axis parallel to the optical axis direction L using a resin material. As shown in FIG. Three follower pins 93 projecting radially outward from the extending portion 92 to be inserted into the inner cam groove 73 of the cam cylinder 70 and formed at equal intervals in the circumferential direction. Etc. are formed.
The second rectilinear cylinder 90 is moved in the optical axis direction L by receiving a cam action by the cam cylinder 70 while being restricted by the second key cylinder 80.

Referring to FIG. 2, when the DC motor 101 rotates from the retracted position as shown in FIG. 2, the rotary cylinder 30 rotates through the gear train and is fed forward in the optical axis direction L as shown in FIG. .
Then, due to the action of the first key cylinder 40 and the connecting cylinder 50, the cam cylinder 70 moves and rotates in the optical axis direction L, exerts a cam action on the first rectilinear cylinder 60 and the second rectilinear cylinder 90, and the first The rectilinear cylinder 60 and the second rectilinear cylinder 90 move relatively in the optical axis direction L, and perform a zooming operation from the wide-angle end to the telephoto end.
On the other hand, when the DC motor 101 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 90 are also retracted and returned to the original retracted position.

In such a driving operation, if any one of the movable members such as the rotary cylinder 30, the first rectilinear cylinder 60, the second rectilinear cylinder 90, etc. moves excessively to a position beyond the allowable movement range, Thus, the gears in the gear train receive an overload (unreasonable force, for example, a meshing force exceeding a predetermined level), but the movable support shafts 113 and 114 are biased in accordance with the force to release the overload. To do.
Thereby, it is possible to prevent biting between gears, breakage of teeth, and the like, and it is possible to easily return to a normal state by starting the DC motor 101.

FIG. 6 shows another embodiment of the driving apparatus according to the present invention. The same components as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.
That is, in this apparatus, as shown in FIG. 6, the two movable support shafts 113 and 114 have one end portions 113a and 114a firmly fitted in the fitting holes 13f and 13g of the holding portion 13, and others. The end portions 113b and 114b are fitted into elastic members 119 and 119 fitted in the concave portions 21f ′ and 21g ′ of the holding portion 21, and are held so as to be able to be deflected in a direction substantially perpendicular to the axis. Here, a rubber member, a spring member, or the like can be used as the elastic member 119.

  According to this, the movable support shafts 113 and 114 are both supported, and the one end portions 113a and 114a are firmly fixed (rigid), and the other end portions 113b and 114b can be biased via the elastic member 119. Therefore, while suppressing unnecessary vibrations on the other end portions 113b and 114b, the other end portions 113b and 114b elastically deform the elastic member 119 when a force exceeding a predetermined level is applied. The overload (unreasonable force) can be released by bending in a direction substantially perpendicular to the axis.

FIG. 7 shows still another embodiment of the driving apparatus according to the present invention. The same components as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted.
That is, in this apparatus, as shown in FIG. 7, the two movable support shafts 113 and 114 are fitted into an elastic member 119 having one end portions 113a and 114a fitted in the recess portions 13f ′ and 13g ′ of the holding portion 13. Further, the other end portions 113b and 114b are fitted into the elastic members 119 and 119 fitted in the concave portions 21f ′ and 21g ′ of the holding portion 21, so that the movable support shafts 113 and 114 are substantially perpendicular to the axis. It is held so that it can be translated in any direction (can be biased).

  According to this, the movable support shafts 113 and 114 are held in a cantilevered manner, and both end portions (one end portions 113a and 114a and the other end portions 113b and 114b) are held so as to be capable of being biased via the elastic member 119. Therefore, while suppressing unnecessary vibration and the like of the movable support shafts 113 and 114, when a force exceeding a predetermined level is applied, the movable support shafts 113 and 114 are elastically deforming the elastic members 119 on both sides to the axis line. It is possible to release an overload (unreasonable force) by translating in a substantially vertical direction, and because the movable support shafts 113 and 114 are deflected without being bent, the gears 107, 108, and 109 are also inclined. It is possible to maintain the optimum meshing angle by translating without any interference.

In the above-described embodiment, the case where three of the five support shafts are fixed support shafts 112, 115, and 116 and two adjacent support shafts are movable support shafts 113 and 114 is shown. However, the present invention is not limited to this, and one support shaft may be used as a movable support shaft, and two support shafts at separate positions may be used as movable support shafts.
In the above-described embodiment, the case where the support shafts 113 and 114 are used as the support shafts supporting the gear 107 and the gears 108 and 109 that form the spur gear is not limited to this. A support shaft that supports a gear having a shape may be a movable support shaft.

  As described above, the lens barrel driving device according to the present invention achieves the simplification of the structure, the reduction of the number of parts, the ease of manufacturing, the miniaturization, the cost reduction, and the like, while the movable member is allowed. Even when overtraveling beyond the range, the gears (gears) can be prevented from biting (locking), tooth breakage, etc., and the expected function can be reliably guaranteed, so it can be used as a driving device for lens barrels, etc. Needless to say, the present invention is not limited to the lens barrel, and any drive device including a gear train is useful for drive devices in other fields.

1 is a front view showing an embodiment of a lens barrel driving apparatus according to the present invention. It is sectional drawing in the surface containing the optical axis which shows one Embodiment of the drive device of the lens barrel which concerns on this invention. FIG. 3 is a partial cross-sectional view taken along a plane perpendicular to the optical axis of the drive device shown in FIGS. 1 and 2. It is a fragmentary sectional view which shows a part of drive device shown in FIG.1 and FIG.2. FIG. 3 is a partial cross-sectional view of a gear train portion of the drive device shown in FIGS. 1 and 2. It is a fragmentary sectional view in the part of the gear train which shows other embodiment of the drive device of the lens barrel concerning the present invention. It is a fragmentary sectional view in the part of the gear train which shows further another embodiment of the drive device of the lens barrel concerning the present invention.

Explanation of symbols

L Optical axis direction G1, G2 Lens 10 Substrate (base)
11 Opening portion 12 Recessed portion 13 Holding portion 13a Mounting portion 13b Bearing holes 13c, 13d, 13e, 13f, 13g Fitting hole 20 Fixed cylinder 21 Holding portion (base)
21c, 21d, 21e Fitting holes 21f, 21g Recess 22 Cylindrical portion 22a Notch portion 22b Cam groove 22c Guide groove 30 Rotating cylinder (rotating member)
31 follower pin 32 tooth row 40 first key cylinder 41 protrusion 42 penetrating cam 43 guide groove 50 connecting cylinder 51 arc-shaped long hole 52 protrusion 53 guide groove 60 first rectilinear cylinder (lens frame)
61 Outer cylindrical part 61a Notch 61b Protrusion 61c Follower pin 62 Inner cylindrical part 70 Cam cylinder 71 Follower pin 72 Outer cam groove 73 Inner cam groove 80 Second key cylinder 81 Connection piece 82 Guide slit 90 Second rectilinear cylinder (lens frame)
91 cylindrical portion 92 extending portion 93 follower pin 100 first drive mechanism 101 DC motor (drive source)
102 Drive gear 103 Gear 104 Worm gear 105 Worm wheel 106, 107, 108, 109, 110, 111 Gear 112, 115, 116 Fixed support shaft 112a, 115a, 116a One end 112b, 115b, 116b The other end 113, 114 Movable support Shafts 113a, 114a One end 113b, 114b The other end 117 Impeller 118 Sensor 119 Elastic member 120 Second drive mechanism

Claims (8)

A base, a rotating member that rotates to drive the lens frame that holds the lens in the optical axis direction, a driving source that is fixed to the base, and a gear train that transmits the rotational driving force of the driving source to the rotating member; A driving device for the lens barrel, comprising a plurality of support shafts that rotatably support the gears included in the gear train,
The plurality of support shafts include a movable support shaft that is held on the base so as to be capable of being biased according to a force received by the gear.
A lens barrel drive device. The plurality of spindles includes four or more spindles;
The four or more support shafts include two movable support shafts that support gears meshing with each other and are held so as to be deflectable in accordance with a force received by the gears.
The lens barrel driving device according to claim 1. The gear supported by the movable support shaft is a spur gear.
The lens barrel driving device according to claim 1 or 2, The movable support shaft is held in a cantilever shape so that one end is fixed to the base and the other end forms a free end that can be biased in a direction substantially perpendicular to the axis.
4. The lens barrel driving device according to claim 1, wherein the lens barrel driving device is a lens barrel driving device. One end of the movable support shaft is fixed to the base, and the other end is held on the base via an elastic member so that it can be deflected in a direction substantially perpendicular to the axis.
4. The lens barrel driving device according to claim 1, wherein the lens barrel driving device is a lens barrel driving device. The movable support shaft is held by the base via an elastic member so that one end and the other end can be biased in a direction substantially perpendicular to the axis.
4. The lens barrel driving device according to claim 1, wherein the lens barrel driving device is a lens barrel driving device. The movable support shaft is formed to be fitted in a through hole of the gear and rotatably support the gear.
The lens barrel driving device according to claim 1, wherein the lens barrel driving device is a lens barrel driving device. The gear train includes a worm gear and a worm wheel.
8. The lens barrel driving device according to claim 1, wherein the lens barrel driving device is a lens barrel driving device.

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