JP2008076813A - Lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a lens barrel configured to move a lens group in an optical axis direction by engaging the lens group with a female screw member moved by a lead screw, that is a compact and inexpensive lens barrel which does not require a sensor to set an initial position for performing the position control of the lens group in the lens barrel. <P>SOLUTION: The lens barrel has: a motor unit having a single motor for moving two lens groups in the optical axis direction and a lead screw; and the female screw member screwed with the lead screw, and constituted so that a lens frame is engaged with the female screw member, so as to move the lens group in the optical axis direction. The female screw member has constitution capable of shifting the screwing with the lead screw. After the female screw member or the lens frame is forcibly locked, the lead screw is rotated further so as to set the initial position of the moving lens group by tooth skipping in the screwing of the female screw member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens barrel having a lens driving device configured to move two lens groups with a single driving source, and an imaging apparatus including the lens barrel.

  2. Description of the Related Art Conventionally, cameras equipped with a variable focal length photographing lens (hereinafter also referred to as a zoom lens) are commercially available. The zoom lens is configured to change the focal length (zooming) by moving a plurality of lens groups constituting the optical system to a desired position along the optical axis and changing the interval therebetween.

  There are roughly two types of methods for moving a plurality of lens groups along the optical axis. The lens frame is engaged with the linear guide, and the lens frame is moved linearly by rotating the cam barrel, and the optical axis is used. A shaft is arranged almost in parallel, and this shaft is used as a guide shaft for rectilinear guide. A sleeve through which the guide shaft passes is formed in the lens frame, and the lens frame is slid directly along the guide shaft using a motor and a lead screw. There is something that lets you move straight ahead.

  The latter, which uses the lead screw to move the lens frame directly along the guide shaft, has a simple structure, so it is often used for lens barrels that do not require a retracting mechanism. There are a lead screw for moving one lens group and a lead screw for moving the other lens group as a driving device that moves the lens frame directly using, from one lead screw to the other lead screw. A lens driving device that transmits power using gears and a belt and moves two lens groups with one motor is known (for example, see Patent Document 1).

In addition, the two shafts with cam grooves are arranged in series with play in the rotational direction, and the lens group that engages the cam grooves of each shaft is driven to perform zooming and focusing with a single motor There is known a lens barrel that performs the above (see, for example, Patent Document 2).
JP 2001-124974 A JP-A-4-317015

  However, when zooming and focusing are performed using a single motor, it is necessary to move the two lens groups while maintaining a predetermined relative positional relationship. It is necessary to have a positional relationship that satisfies a predetermined condition with respect to the lead screw in advance.

  Furthermore, in order to control the position of the lens group, a shielding part is formed on the lens frame, and the initial position of the lens frame is confirmed by passing the shielding part through a photo sensor such as a photo interrupter. A system used for controlling the lens group position is generally used.

  In such a system, it is necessary to mount a photosensor such as a photo interrupter, which becomes an obstacle when the lens barrel is further reduced in size or cost.

  In view of the above problems, the present invention is an initial stage for controlling the position of a lens group of a lens barrel configured to engage a female screw member that is moved by a lead screw and move in the optical axis direction. An object of the present invention is to obtain a small and low-cost lens barrel without requiring a sensor for position setting.

  The above object is achieved by the invention described below.

  1. A motor unit having a plurality of lens groups, a single motor for moving two of the plurality of lens groups in the optical axis direction, and a lead screw that is rotated in conjunction with the rotation of the motor. And a lens barrel configured to be movable in the optical axis direction by engaging a lens frame holding the moving lens group with the female screw member. The female screw member is configured to be able to skip the screwing with the lead screw, and after forcibly locking the female screw member or the lens frame holding the moving lens group, A lens barrel characterized in that the lead lens is further rotated and the threaded engagement of the female screw member is skipped to set the initial position of the moving lens group.

  2. 2. The lens barrel according to 1, wherein a locking portion for forcibly locking the female screw member or a lens frame holding the moving lens group is formed at a wide-angle end position or a telephoto end position.

  3. A lens frame having a lens group, a motor unit having a motor and a lead screw that is rotated in conjunction with rotation of the motor, and a female screw member that is screwed into the lead screw, and holding the lens group In the lens barrel configured to engage the female screw member and move in the optical axis direction, the female screw member is configured to be capable of skipping engagement with the lead screw. After forcibly locking the screw member or the lens frame holding the lens group, the lead screw is further rotated, and the threaded engagement of the female screw member is skipped to set the initial position of the moving lens group. A lens barrel characterized by that.

  4.1. An imaging apparatus comprising the lens barrel according to any one of 1 to 3.

  According to the present invention, a sensor for detecting the initial position for controlling the position of the lens group is not required, and a small and low-cost lens barrel can be obtained.

  Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

  FIG. 1 is a diagram illustrating an example of an internal arrangement of main constituent units of a camera 100 that is an example of an imaging apparatus including a lens barrel according to the present embodiment. FIG. 3 is a perspective view of the camera 100 as viewed from the subject side.

  As shown in the figure, in the camera 100, a lens barrel 50 according to the present invention that includes a foldable imaging optical system capable of zooming is arranged vertically on the right side as shown in the figure, and an opening 51 takes in a subject light flux. Has been placed. The opening 51 is provided with a lens barrier (not shown) that is in an open state that exposes the opening 51 and a closed state that covers the opening 51.

  Reference numeral 52 denotes a flash light emission window. Reference numeral 53 denotes a flash unit including a reflector, a xenon tube, other main capacitors, a circuit board, and the like disposed behind the flash light emission window. Reference numeral 54 denotes a card-type image recording memory. A battery 55 supplies power to each part of the camera. The image recording memory 54 and the battery 55 can be inserted and removed from a lid (not shown).

  A release button 56 is disposed on the upper surface of the camera. When the first button is pushed, a shooting preparation operation of the camera, that is, a focusing operation and a photometric operation are performed, and a shooting exposure operation is performed by pushing the second button. A main switch 57 is a switch for switching the camera between an operating state and a non-operating state. When switched to the operating state by the main switch 57, the lens barrier (not shown) is opened and the operation of each part is started. When the main switch 57 is switched to the non-operating state, the lens barrier (not shown) is closed and ends the operation of each unit.

  On the back side of the camera, an image display unit 58 configured by an LCD, an organic EL, or the like and displaying an image and other character information is disposed. Although not shown, a zoom button for zooming up and down, a playback button for playing back a captured image, a menu button for displaying various menus on the image display unit 58, and a desired function are selected from the display. An operation member such as a selection button is arranged.

  Although not shown, each part is connected between these main constituent units and a circuit board on which various electronic components are mounted is arranged to drive and control each main constituent unit. Yes. Similarly, although not shown, an external input / output terminal, a strap attaching portion, a tripod seat, and the like are provided.

  FIG. 2 is a cross-sectional view showing an example of a foldable imaging optical system capable of zooming, which is included in the lens barrel 50 according to the present embodiment. This figure is a cross-sectional view taken along a plane including two optical axes before and after bending.

  As shown in the figure, OA is the optical axis before bending, and OB is the optical axis after bending. Reference numeral 1 denotes a first lens group. The first lens group 1 includes a lens 11 that is disposed toward a subject with an optical axis OA, a prism 12 that is a reflecting member that bends the optical axis OA in a substantially right angle direction, and a prism 12. The lens 13 is disposed with the optical axis OB bent by the optical axis as the optical axis. The first lens group 1 is a lens group fixed to the main body 9.

  Reference numeral 2 denotes a second lens group, which is incorporated in the second lens group frame 2k. The second lens group is a lens group that moves together with the second lens group frame 2k during zooming (hereinafter also referred to as zooming).

  Reference numeral 3 denotes a third lens group, which is fixed to the main body 9. The third lens group 3 is a lens group that does not move.

  Reference numeral 4 denotes a fourth lens group, which is incorporated in the fourth lens group frame 4k. The fourth lens group is a lens group that moves integrally with the fourth lens group lens frame 4k at the time of zooming, and also moves alone to perform focus adjustment (hereinafter also referred to as focusing).

  Reference numeral 5 denotes a fifth lens group, which is fixed to the main body 9. The fifth lens group 5 is a lens group that does not move.

  Reference numeral 7 denotes an optical filter in which an infrared light cut filter and an optical low-pass filter are stacked, and is assembled to the main cylinder 9. Reference numeral 8 denotes an image sensor, and a CCD (Charge Coupled Device) type image sensor, a CMOS (Complementary Metal-Oxide Semiconductor) type image sensor, or the like is used. The image sensor 8 is assembled to the main body 9. The FPC is a flexible printed circuit board that is connected to the image sensor 8 and connected to other circuits in the camera. S is an aperture shutter unit, which is fixed to the main cylinder 9. Reference numeral 10 denotes a lid member assembled to the main body 9.

  FIG. 3 is a plan view showing a schematic structure inside the main barrel 9 of the lens barrel 50 according to the present embodiment. The figure schematically shows the lid 10 removed from the lens barrel 50 shown in FIG. 2 and a motor or the like arranged outside the lens barrel for the sake of simplicity.

  As shown in the figure, the lens barrel 50 has a sleeve 2s formed integrally with the second lens group frame 2k and a sleeve 4s formed integrally with the fourth lens group frame 4k. A guide shaft 15 is provided. Further, the guide shaft 16 penetrates the rotation locking portion 2m formed integrally with the second lens group lens frame 2k and the rotation locking portion 4m formed integrally with the fourth lens group lens frame 4k. Is provided. Accordingly, the second lens group lens frame 2k and the fourth lens group lens frame 4k are slidable along the guide shafts 15 and 16 in the direction of the optical axis OB. The sleeve 2s and the sleeve 4s are respectively fitted with guide shafts, and the guide shafts 15 and 16 are disposed substantially parallel to the optical axis OB, and are fixed to the main body 9 at both ends by, for example, adhesion.

In the stepping motor 20 (hereinafter also referred to as “motor”), a lead screw 20 r that is a male screw member is disposed on an extended line of a rotating shaft and supported by a support member 25. In the lead screw 20r, a first screw groove 20r ₁ and a second screw groove 20r ₂ having different pitches and screw advance directions are formed on one shaft. The lead screw 20r having the first and second screw grooves 20r ₁ and 20r ₂ may be individually manufactured and joined to be integrated, or may be processed from an integrated shaft.

A U-shaped engaging portion 2t is formed on the sleeve 2s formed on the second lens group frame 2k, and a shaft 26 is assembled to the engaging portion 2t, and slides in the axial direction with respect to the shaft 26. A female screw member 23 that can be rotated around an axis is assembled. The female screw member 23 has a partial female screw portion, and this female screw portion is pressed and urged by an urging member (not shown) so as to be screwed into the _first screw groove 20r ₁ . The female screw member 23 has a predetermined play amount (corresponding to the figure (t ₂ -t ₁ )) and is engaged with the engaging portion 2t.

When the lead screw 20r is rotated, that is, the first screw groove 20r _{1 is} rotated from the state shown in the figure, and the female screw portion 23 is moved along the optical axis OB in the direction of the image sensor 8, first, the play amount (t ₂ -t ₁ ) After moving in, contact with the engaging portion 2t. Thereafter, the second lens group frame 2k, that is, the second lens group 2 is moved by further moving.

The sleeve 4s is integrally formed with a U-shaped engaging portion 4t. A shaft 27 is assembled to the engaging portion 4t, and a female screw member 24 that is axially fitted to the shaft 27 and is rotatable about the shaft is assembled. The female screw member 24 has a partial female screw portion, and this female screw portion is pressed and urged by an urging member (not shown) so as to be screwed into the _second screw groove 20r2.

  As a result, the second lens group 2 and the fourth lens group 4 approach the third lens group 3 from both sides with different movement amounts due to the rotation of the first motor 20 in a predetermined direction, and the reverse direction of the first motor 20. , Both of them move away from the third lens group 3 with different movement amounts.

  Further, when the female screw member 23 moves to a predetermined position, the main barrel 9 comes into contact with the locking portion 28 and the female screw member 24, which are forcibly disabled to move, when the female screw member 24 moves to a predetermined position. A locking portion 29 that is in contact with and forcibly disabled is formed. That is, the female screw members 23 and 24 can move only within a region sandwiched between the locking portions.

  The position of the locking portion 28 is, for example, in a state where the female screw member 23 is in contact with the first lens group side of the engaging portion 2t, and the second lens group 2, that is, the second lens group lens frame 2k is at the wide angle end. It is formed at a position where the female screw member 23 is locked at a position closer to the first lens group 1 than the position or the position at the wide-angle end.

  The position of the locking portion 29 is, for example, the state where the fourth lens group 4, that is, the fourth lens group frame 4 k is at an infinite position in the focusing region at the wide-angle end in a state where the female screw member 24 is engaged with the engaging portion 4 t It is formed at a position where the female screw member 24 is locked at a position closer to the fifth lens group 5 than the infinity position.

  Hereinafter, the structure around the female screw member 23 and the female screw member 24 according to the present embodiment will be described in detail.

  FIG. 4 is a view showing the structure around the female screw member 23 and the sleeve 2s. 4A is a view of the periphery of the female screw member 23 and the sleeve 2s in the axial direction of the guide shaft 15, and FIG. 4B is a direction in which the periphery of the female screw member 23 and the sleeve 2s is orthogonal to the guide shaft 15. It is the figure seen from.

As shown in the figure, the friction member 21 urged by the compression coil spring 22 is pressed against the guide shaft 15 at the penetrating portion of the guide shaft 15 penetrating the sleeve 2s. Thereby, even if the engaging part 2t formed in the sleeve 2s and the female screw member 23 have a play amount, and the engaging part 2t and the female screw member 23 are separated from each other, the second lens group frame 2k is The stopped state can be maintained by this frictional force. The female screw member 23 moves along the shaft 26 by the rotation of the _first screw groove 20r1 to be screwed, abuts against the engaging portion 2t, and gives the engaging portion 2t a force to overcome this frictional force. Thus, the second lens group frame 2k is moved in the direction of the optical axis OB.

Moreover, as engagement portion 23r of the female screw member 23 is biased in the direction of the arrow shown in the diagram (a) by a spring 31, is engaged with a part of a cylindrical first screw groove 20r ₁ It has become. Thus, the female screw member 23 can be moved by the rotation of the first screw groove 20r ₁ . On the other hand, when the female screw member 23 or the sleeve 2s is in contact with the locking portion 28, the female screw member 23 resists the biasing force of the spring 31 even if the first screw groove 20r ₁ rotates. The screwing portion 23r is spun off by rotating clockwise around No. 26, and the stopped state is maintained by shifting the screwing.

  FIG. 5 is a view showing a structure around the female screw member 24 and the sleeve 4s. 4A is a view of the periphery of the female screw member 24 and the sleeve 4s as viewed in the axial direction of the guide shaft 15. FIG. 5B is a direction in which the periphery of the female screw member 24 and the sleeve 4s is orthogonal to the guide shaft 15. It is the figure seen from.

  As shown in the figure, the female screw member 24 is rotatably supported by the shaft 27 and is fitted to the engaging portion 4t.

Moreover, as engagement portion 24r of the female screw member 24 is biased in the direction of the arrow shown in the diagram (a) by a spring 32, is engaged with a portion of the cylindrical second screw groove 20r ₂ It has become. Thus the female screw member 24 i.e. the fourth lens group holding frame is adapted to be moved by the rotation of the second screw groove 20r _2. On the other hand, when the female screw member 24 or sleeve 4s is in contact with the locking portion 29, even when the second screw groove 20r ₂ is rotated, the female screw member 24 against the biasing force of the spring 32 axis The screwing portion 24r is rotated clockwise around the rotation 27, and the stopped state is maintained by shifting the screwing.

  The initialization operation of the lens barrel having the above configuration will be described.

  FIG. 6 is an example of a flowchart showing the initialization operation of the lens barrel according to the present embodiment. In this flow, the locking portion 28 is formed so that the female screw member 23 is locked at a position where the second lens group frame 2k is at the wide-angle end or at a position closer to the first lens group 1 than the position at which the second lens-group frame 2k is the wide-angle end. A locking portion 29 is formed so that the fourth lens group lens frame 4k locks the female screw member 24 at a position on the fifth lens group 5 side from the infinity position or the infinity position of the focusing area at the wide-angle end. If it is.

  First, it waits for a camera equipped with a lens barrel to be powered on (step S11). When the power is turned on (step S11; Yes), the rotation of the motor is started so that the second and fourth lens group lens frames, that is, the female screw members 23 and 24, move in the wide end direction (step S12). Further, the motor is rotated by a predetermined number of steps (step S13), and the process ends.

  The predetermined number of steps is, for example, the number of steps that is the number of rotations obtained by adding at least one rotation to the number of motor rotations in the range in which the female screw members 23 and 24 are movable. By setting the number of steps in this manner, even if the second lens group frame 2k or the female screw member 23 is moved due to an impact or the like until the camera is powered on, the female screw member 23 is always generated. In addition, the second lens group frame 2k can be forcibly brought into contact with the engaging portion 28, and the initial positions of the female screw member 23 and the second lens group frame 2k can be set.

  Further, the female screw member 23 and the second lens group frame 2k come into contact with the locking portion 28 in the middle of the rotation of the above number of steps, and the screwing portion 23r skips in the subsequent over-rotation state. The contact state is maintained by shifting the screw engagement.

  The same applies to the female screw member 24, the fourth lens group lens frame, and the locking portion 29. That is, even if the fourth lens group lens frame 4k or the female screw member 24 is moved due to an impact or the like until the camera is powered on, the female screw member 24 and the fourth lens group lens frame 4k must be moved. The locking portion 29 can be forcibly brought into contact, and the initial positions of the female screw member 24 and the fourth lens group lens frame 4k are set.

  Further, the female screw member 24 and the fourth lens group lens frame 4k come into contact with the engaging portion 29 in the middle of the rotation of the number of steps described above, and in the subsequent over-rotation state, the screwing portion 24r skips teeth. The contact state is maintained by shifting the screw engagement.

  In other words, the lens barrel of the present embodiment is configured so that the female screw member can be skipped, and the initial position of the lens frame is set by forcibly abutting the lens frame or the female screw member on the locking portion. It is what I did. As a result, a sensor for setting the initial position for controlling the position of the lens group can be eliminated, and a small and low-cost lens barrel can be obtained.

  In addition, even when the relative positional relationship of the lens frame holding the lens group is shifted due to an impact or the like, it is possible to reset the predetermined initial conditions. Furthermore, in the over-rotation region after abutment, it is possible to prevent an excessive mechanical load from being applied by shifting the screwing of the female screw member with respect to the rotation of the lead screw.

  When the lens barrel of the present embodiment is used in a camera, it is preferable to set the initial position at power-on. However, for example, when used in a mobile phone, the lens barrel is set to the camera mode. It is preferable to set the initial position as described above.

  Further, although the description has been given with the locking position set at the wide-angle end, it may be set at the telephoto end or the locking position may be set outside the imaging area.

  Hereinafter, zooming and focusing operations of the lens barrel according to the present embodiment will be described.

  FIG. 7 is a diagram showing a lens group position control method when the second lens group and the fourth lens group of the lens barrel 50 according to the present embodiment are moved from the initial position setting at the wide-angle end to the telephoto side. is there. 4A is a movement diagram of the second lens group and the fourth lens group, and FIGS. 4B to 4E are engaging portions 2t of the sleeve 2s and the female screw member 23, and the sleeve 4s and the female lens. It is a figure which shows the position of the screw member. The figure shows a case where a locking portion 28 is formed so as to lock the female screw member 23 at a position where the second lens group lens frame 2k is at the wide-angle end.

  As shown in FIG. 5A, the second lens group 2 and the fourth lens group 4 are moved so as to approach the third lens group 3 so that the magnification is changed from wide angle (W) to telephoto (T). To do.

The width between the broken line A and the second solid line indicating the position of the second lens group 2 shown in FIG. 6A corresponds to the play amount (t ₂ -t ₁ ), and the female screw member is the play amount. When 23 moves, the female screw member 24 and the fourth lens group 4 move from the broken line C to the position of the broken line B. The solid line 4∞ indicates the position of the fourth lens group 4 that focuses on infinity at each focal length position. Hereinafter, a description will be given with reference to FIGS.

  In the initial position setting state described above, the wide-angle (W) state shown in FIG. 5B is obtained, and the female screw member 23 is in contact with the engaging portion 2t on the first lens group 1 side (position Aw). The female screw member 24 and the fourth lens group 4 are at the position Cw.

First, the motor is driven so that the female screw member 23 is moved from the Aw position to the 2w position. As a result, the female screw member 23 moves by an amount corresponding to the play amount (t ₂ −t ₁ ) and comes into contact with the other end of the engaging portion 2t. The second lens group frame 2k remains stopped. At this time, the female screw member 24 and the fourth lens group lens frame 4k move from the Cw position to the Bw position. The state at this position is shown in FIG.

  When photographing at the wide angle (W) position, the movement within this region, that is, the female screw member 24 and the fourth lens group frame 4k are moved from Cw to 4w, and then the subject is moved between 4w and Bw. Focusing is performed.

  For example, in zooming from the wide angle (W) position to the telephoto focal length MA, the motor is further driven in the same direction, and the female screw member 23 is moved to a position of 2 ma and stopped. As a result, the second lens group frame 2k approaches the third lens group 3 and is in a position necessary for the focal length MA. At this time, the female screw member 24 and the fourth lens group frame 4k move from the position Bw to the position Bma. The state at this position is shown in FIG.

  Next, the motor is driven in reverse to move the female screw member 24 and the fourth lens group frame 4k from the Bma position to the 4ma position. At this time, the female screw member 23 moves from the position of 2ma in the direction of Ama. However, as shown in FIG. 4D, the female screw member 23 and the engaging portion 2t are moved within the play amount, so that they are separated from each other. Thus, the second lens group frame 2k remains stopped. This state is a state in which the second lens group 2 and the fourth lens group 4 have a focal length MA and the focus is adjusted with respect to a subject at infinity.

  Thereafter, the motor is driven so as to move the female screw member 24 between 4ma and Bma, so that the fourth lens group lens frame 4k is stopped while the second lens group lens frame 2k is stopped. Focusing can be performed by moving in the state as shown in FIG. That is, the hatching area between the solid line and the broken line B of the fourth lens group 4 in FIG. 4A is the focusing area of the fourth lens group.

  As described above, zooming from the wide-angle side to the telephoto side can be performed by the movement of FIGS. 7B to 7D, and focusing can be performed by the movement of FIGS.

  FIG. 8 is a diagram showing drive control when the second lens group and the fourth lens group of the lens barrel 50 according to the present embodiment are moved from the telephoto side to the wide angle side. 4A is a movement diagram of the second lens group and the fourth lens group, and FIGS. 4B to 4E are engaging portions 2t of the sleeve 2s and the female screw member 23, and the sleeve 4s and the female lens. It is a figure which shows the position of the screw member.

  The state will be described from the state in which the female screw member 23 is at the position 2ma and the state in which the female screw member 24 is at the position Bma (the state shown in FIG. 5B).

  First, the motor is driven so that the female screw member 23 is moved from the 2ma position to the Ama position and the female screw member 24 is moved from the Bma position to the Cma position. The state at this position is shown in FIG.

  Further, the motor is driven in the same direction, and the female screw member 23 is moved to the Amb position and stopped. As a result, the second lens group frame 2k moves in a direction away from the third lens group 3, and becomes a position necessary to obtain the focal length MB. At this time, the female screw member 24 and the fourth lens group frame 4k move from the position of Cma to the position of Cmb. The state at this position is shown in FIG.

Next, the motor is driven in the reverse direction to move the female screw member 24 and the fourth lens group frame 4k from the Cmb position to the 4mb position. At this time, the female screw member 23 moves in the direction of 2 mb from the position of Amb. However, as shown in FIG. 5E, the female screw member 23 and the engaging portion 2t are within the play amount (t ₂ -t ₁ ). The second lens group lens frame 2k remains stopped because of the movement. This state is a state in which the second lens group 2 and the fourth lens group 4 have a focal length MA and the focus is adjusted with respect to a subject at infinity.

  Thereafter, by driving the motor so as to move the female screw member 24 between 4 mb and Bmb, focusing is performed by moving only the fourth lens group frame 4k while stopping the second lens group frame 2k. It can be carried out.

  As described above, zooming from the wide-angle side to the telephoto side is performed by the movement of FIGS. 7B to 7D, and the focus adjustment to the infinite object is performed by the movement of FIGS. From FIG. 5E, focusing can be performed by moving only the fourth lens group 4k.

  In the above embodiment, the zoom lens is used to move the two lens groups. However, the present invention is not limited to this, and only one lens group is moved. Three or more lens groups are moved. It is also applicable to those to be made.

  In addition, although a camera has been described as an example of the imaging apparatus, the present invention can also be applied to a camera module built in a portable terminal such as a PDA or a mobile phone. Further, although the bending optical system has been described, the present invention can also be applied to a lens barrel that includes an optical system having no reflecting surface.

It is a figure which shows an example of the internal arrangement | positioning of the main structural unit of the camera which is an example of the imaging device provided with the lens barrel which concerns on this Embodiment. It is sectional drawing which shows an example of the bending imaging optical system which can be changed in magnification included in the lens barrel which concerns on this Embodiment. It is a top view which shows schematic structure inside the main cylinder of the lens barrel which concerns on this Embodiment. It is a figure which shows the structure around the internal thread member 23 and the sleeve 2s. It is a figure which shows the structure around the internal thread member 24 and the sleeve 4s. It is an example of the flowchart which shows the initialization operation | movement of the lens barrel which concerns on this Embodiment. It is a figure which shows the lens group position control method at the time of moving the 2nd lens group and 4th lens group of the lens barrel which concerns on this Embodiment from the initial position setting in a wide angle end to a telephoto side. It is a figure which shows drive control at the time of moving the 2nd lens group and 4th lens group of the lens barrel which concerns on this Embodiment from the telephoto side to the wide angle side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens group 2 2nd lens group 2k 2nd lens group frame 3 3rd lens group 4 4th lens group 4k 4th lens group frame 5 5th lens group 7 Optical filter 8 Image sensor 9 Main trunk 10 Lid Member 15, 16 Guide shaft 20 Stepping motor 20r Lead screw 23, 24 Female thread member OA, OB Optical axis 50 Lens barrel 100 Camera

Claims (4)

A motor unit having a plurality of lens groups, a single motor for moving two of the plurality of lens groups in the optical axis direction, and a lead screw that is rotated in conjunction with the rotation of the motor. And a lens barrel configured to be movable in the optical axis direction by engaging a lens frame holding the moving lens group with the female screw member. In
The female screw member is configured to be able to skip the screwing with the lead screw,
After forcibly locking the female screw member or the lens frame holding the moving lens group, the lead screw is further rotated, and the threaded engagement of the female screw member is skipped to move the initial position of the moving lens group. A lens barrel characterized by setting. 2. The lens barrel according to claim 1, wherein a locking portion for forcibly locking the female screw member or a lens frame holding the moving lens group is formed at a wide-angle end position or a telephoto end position. . A lens frame having a lens group, a motor unit having a motor and a lead screw that is rotated in conjunction with rotation of the motor, and a female screw member that is screwed into the lead screw, and holding the lens group In a lens barrel configured to engage the female screw member and move in the optical axis direction,
The female screw member is configured to be able to skip the screwing with the lead screw,
After forcibly locking the female screw member or the lens frame holding the lens group, the lead screw is further rotated, and the threaded engagement of the female screw member is skipped to set the initial position of the moving lens group A lens barrel characterized by An imaging apparatus comprising the lens barrel according to claim 1.

Images