JP4919517B2 - Lens barrel and imaging device - Google Patents

Description

  The present invention relates to a lens barrel that retracts a lens group in one form, and extends and uses the lens group to a predetermined position in another form. In particular, the focal length is obtained by relatively moving a plurality of lens groups. The present invention relates to a lens barrel and an imaging apparatus suitable for a zoom lens that changes the lens.

2. Description of the Related Art Conventionally, in an imaging apparatus such as a digital camera, the movable lens barrel is retracted inside the camera body except during shooting, as the performance of an imaging lens such as a zoom lens increases and the size is reduced according to user requirements. What has a type of imaging lens is required. Furthermore, due to the demand for thin camera body (imaging device main body), it is important to minimize the dimension of the movable lens barrel in the retracted storage state in the direction of the photographic optical axis.
In response to such a request for reducing the thickness of the camera body, conventionally, as shown in, for example, Japanese Patent Application Laid-Open No. 2006-330657, at least a part of a plurality of lens groups is retracted to make the lens group a body. A plurality of lens holding frames for holding the plurality of lens groups for each lens group in order to obtain a photographing state by moving at least a part of the lens group from the retracted state housed therein to the objective side; The lens holding frame includes: a movable lens barrel that holds the lens holding frame therein; and a lens holding frame driving unit that drives the lens holding frame via the movable lens barrel. All lens groups are positioned on the photographic optical axis, and in the retracted state, at least one lens group is at a position different from the photographic optical axis and larger than the maximum outer diameter of the movable lens barrel of the other lens group. A lens barrel including a retractable lens holding frame that holds and moves the lens group in order to retract the lens group in a direction in which the retractable lens holding frame is inserted on the optical axis of the other lens group. There has been proposed a lens barrel including a common and single compression torsion spring that is always urged and always urged in the retracted direction along the optical axis direction.

  In the above-described configuration, when the movable lens barrel is stored, a part of the lens group is retracted to the outside of the maximum outer diameter of the movable lens barrel, and the retraction guiding functional component can be urged in two directions. By using a common compression torsion spring, it is possible to reduce the dimension of the movable lens barrel in the photographic optical axis direction while minimizing the parts space and the number of parts, and the camera body (the main part of the photographic device) can be made thinner. Can be planned.

JP 2006-330657 A

However, in the shape of the compression torsion spring disclosed in Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-330657) and the like, there is only one position restricting portion on the fixed side, so that the installation position can be stabilized during assembly. It is difficult and the assembly work cannot be performed stably. For this reason, the compression torsion spring is buckled during the operation of the retractable lens holding frame due to extra work time and difficulty in completely regulating the position. There is a possibility that the position of the neighborhood changes and a problem of causing a drive operation failure may occur.
The present invention has been made in view of the circumstances described above, and a lens that can improve assembly stability and drive operation stability without increasing the size of the lens barrel or changing the configuration. An object of the present invention is to provide a lens barrel and an imaging device.
The object of the first aspect of the present invention is to make it easy to manufacture an elastic member that urges as required particularly in relation to driving of the retractable lens holding frame, and to improve assembly stability and drive operation stability more easily. It is an object of the present invention to provide a lens barrel that makes it possible.
The object of claim 2 of the present invention is to appropriately restrict the movable position of the elastic member, effectively preventing the elastic member from interfering with the retractable lens holding frame, and improving the driving stability of the elastic member. It is an object of the present invention to provide a lens barrel that can be used.

The object of claim 3 of the present invention is that the positional relationship between the fixing member and the second fixing portion fixed to the fixing member is clear and accurate, positioning can be performed easily and more stably, and assembly stability can be achieved. It is an object of the present invention to provide a lens barrel that can improve the above.
The object of claim 4 of the present invention is in particular that the elastic member can be fixed at a plurality of positions of equal angles, the position of the elastic member during operation can be stabilized, and driving stability can be improved. It is to provide a lens barrel.
The purpose of claim 5 of the present invention, in particular, with a simple configuration, is to provide an imaging device capable of stable operation.

In order to achieve the above-described object, a lens barrel according to the present invention described in claim 1 is provided.
A plurality of lenses; a plurality of lens holding frames that hold the lenses; and a lens drive frame that holds and drives the lens holding frames, and at least one of the plurality of lenses is light of the lenses. As the retractable lens that retracts away from the axis, the retractable lens holding frame, which is a lens holding frame that holds the retractable lens, is urged in one of the directions in and out of the optical axis of the lens and simultaneously with the optical axis. In a lens barrel comprising: a substantially cylindrical elastic member that biases in a parallel direction; and a fixing member that fixes the elastic member.
The elastic member is
As a torsion spring that generates a torsion force by further winding the other end in the winding direction of the compression coil spring with one end of the both ends of the compression coil spring having a substantially cylindrical shape fixed. A compression torsion spring to act,
A first fixing portion for fixing the one end portion of the compression torsion spring to the fixing member formed to extend outward in the substantially cylindrical shape;
A second fixing portion for fixing to the fixing member formed in the same winding as the one end portion of the compression torsion spring and protruding substantially in a U shape in the radial direction. Yes.

A lens barrel according to a second aspect of the present invention is the lens barrel according to the first aspect,
At least the end winding on the one end side of the compression torsion spring is removed on the opposite side to the resultant vector direction of the torsion force at the second fixing portion and the torsion force at the other end of the compression torsion spring. The compression torsion spring has a guide portion that is implanted in the fixing member so as to be locked in parallel with the substantially cylindrical central axis of the compression torsion spring so as to lock one or more outer shapes .

A lens barrel according to a third aspect of the present invention is the lens barrel according to the first or second aspect ,
The fixing member is provided with at least one protrusion that engages with the second fixing portion to determine the position of the elastic member.
A lens barrel according to a fourth aspect of the present invention is the lens barrel according to any one of the first to third aspects,
A plurality of the second fixing portions are provided, and the first fixing portions and the plurality of second fixing portions are arranged at equal angles to each other.
An imaging apparatus according to the present invention described in claim 5 is:
As an imaging lens, the lens barrel according to any one of claims 1 to 4 is provided.

According to the present invention, it is possible to provide a lens barrel and an imaging apparatus capable of improving assembly stability and driving operation stability without increasing the size of the lens barrel or changing the configuration. Can do.
That is, according to the lens barrel of claim 1 of the present invention,
A plurality of lenses; a plurality of lens holding frames that hold the lenses; and a lens drive frame that holds and drives the lens holding frames, and at least one of the plurality of lenses is light of the lenses. As the retractable lens that retracts away from the axis, the retractable lens holding frame, which is a lens holding frame that holds the retractable lens, is urged in one of the directions in and out of the optical axis of the lens and simultaneously with the optical axis. In a lens barrel comprising: a substantially cylindrical elastic member that biases in a parallel direction; and a fixing member that fixes the elastic member.
The elastic member is
As a torsion spring that generates a torsion force by further winding the other end in the winding direction of the compression coil spring with one end of the both ends of the compression coil spring having a substantially cylindrical shape fixed. A compression torsion spring to act,
A first fixing portion for fixing the one end portion of the compression torsion spring to the fixing member formed to extend outward in the substantially cylindrical shape;
By having a second fixing portion for fixing to the fixing member formed in the same winding as the one end portion of the compression torsion spring and projecting in a substantially U shape in the radial direction,
An elastic member that biases as required in relation to driving of the retractable lens holding frame can be manufactured easily and inexpensively, and assembly stability and driving operation stability can be improved more easily.

According to the lens barrel of claim 2 of the present invention, in the lens barrel of claim 1,
At least the end winding on the one end side of the compression torsion spring is removed on the opposite side to the resultant vector direction of the torsion force at the second fixing portion and the torsion force at the other end of the compression torsion spring. By having a guide part implanted in the fixing member so as to protrude parallel to the substantially cylindrical central axis of the compression torsion spring so as to lock the outer shape of one or more turns,
In particular, the movable position of the elastic member is appropriately regulated to effectively prevent the elastic member from interfering with the retractable lens holding frame, and the driving stability of the elastic member can be improved .

According to the lens barrel of claim 3 of the present invention, in the lens barrel of claim 1 or claim 2 ,
By providing the fixing member with at least one protrusion that engages with the second fixing portion and determines the position of the elastic member,
In particular, the positional relationship between the fixing member and the second fixing portion fixed thereto is clear and accurate, positioning can be performed easily and more stably, and assembly stability can be improved.
According to the lens barrel of claim 4 of the present invention, in the lens barrel of any one of claims 1 to 3 ,
By providing a plurality of the second fixing parts and arranging the first fixing parts and the plurality of second fixing parts at equal angles,
In particular, the elastic member can be fixed at a plurality of positions at equal angles, the position of the elastic member during operation can be stabilized, and driving stability can be improved.

According to the imaging device of claim 5 of the present invention,
An imaging apparatus according to the present invention described in claim 5 is:
By providing the lens barrel of at least any one of claims 1 to 4 as an imaging lens,
In particular, stable operation is possible with a simple configuration.

  Hereinafter, based on an embodiment of the present invention, a lens barrel and an imaging device of the present invention will be described in detail with reference to the drawings. It should be noted that the matters related to the embodiments of the present invention described in the present specification and the drawings are merely examples, and do not limit the technical scope of the present invention.

FIGS. 1 to 15 show the configuration and various operating states of a lens barrel mechanism that is a main part of a camera as an imaging device configured using a lens barrel according to an embodiment of the present invention. . In order to clarify the problem caused by the conventional configuration and the configuration of the present invention to deal with it, FIGS. 4 to 6 show the conventional configuration of the part related to the features of the present invention, and FIGS. The structure which concerns on embodiment of this invention is shown.
FIG. 1 is a perspective view of a configuration of a part related to a lens barrel mechanism including a lens barrel in a retracted storage state in which a lens group is retracted and stored from the object side (subject side). FIG. 2 is a longitudinal cross-sectional view showing the main parts of each lens group, a lens holding frame, and various lens barrels in a retracted lens barrel in which the lens group is projected and retracted, and FIG. FIG. 3 is a longitudinal sectional view showing main parts of each lens group, a lens holding frame, and various lens barrels in a lens barrel in a wide-angle position state in which the lens group protrudes. FIG. 4 is a side view showing the configuration of a third lens holding frame for holding a third lens group as a retracting lens group and its driving operation system, and FIG. 5 shows a compression torsion spring as an elastic member of a conventional fixed structure. FIG. 6 is a perspective view of the configuration of the third lens holding frame and its driving operation system when used, viewed from the image plane side, and FIG. 6 uses a compression torsion spring as an elastic member of a conventional fixed structure as in FIG. FIG. 7 is a perspective view of the third lens holding frame and the drive system thereof when viewed from the object side on the substantially rear side of FIG. 5, and FIG. 7 is a third lens for explaining the operation of the third lens holding frame. It is the front view which looked at the holding frame part from the object side.

FIG. 8 is a developed view schematically showing the shape of the cam groove formed in the second rotating cylinder, and FIG. 9 is a developed view schematically showing the shape of the cam groove formed in the cam cylinder. Development,
FIG. 10 is a developed view schematically showing the shape of the cam groove and key groove formed in the fixed lens barrel and omitting the helicoid, and FIG. 11 is a cam groove formed in the fixed lens barrel of FIG. FIG. 12 is a perspective view of the first rotating lens barrel that fits into the helicoid of the fixed lens barrel, in which the shape of the keyway is developed and the helicoid is shown in detail.
FIG. 13 substantially corresponds to FIG. 5, and is a perspective view showing the configuration of the third lens holding frame and its driving operation system when a compression torsion spring is used as an elastic member having a fixed structure according to the present invention. FIG. 13 shows the configuration of the third lens holding frame in FIG. 13 and its driving operation system when the third lens holding frame is extended to the telephoto position (the state where the compression torsion spring is most compressed), and is viewed from substantially the back side of FIG. FIG. 15 is a front view seen from the object side showing the positional relationship between the direction of each force generated from the compression torsion spring and the guide shaft.

  1 to 7, the lens barrel mechanism, which is the main part of the camera including the lens barrel, includes a first lens group 11, a second lens group 12, a third lens group 13, a fourth lens group 14, a shutter / Aperture unit 15, solid-state imaging device 16, first lens holding frame 17, cover glass 18, low-pass filter 19, fixed frame 21, first rotating cylinder 22, first liner 23, second rotating cylinder 24, second Liner 25, cam cylinder 26, rectilinear cylinder 27, third lens holding frame 31, third group main guide shaft 32, third group sub guide shaft 33, third group lead screw 34, third group female screw member 35, compression Torsion spring 36 (this compression torsion spring 36 uses the conventional fixing structure shown in FIGS. 4 to 6), third group photo interrupter 37 (see FIGS. 5 and 7), 4 lens protection Holding frame 41 (see FIGS. 2 and 3), zoom motor 51 (see FIG. 1), third group motor 52 (see FIGS. 1 and 4), fourth group motor 53 (see FIG. 1), gears 71 and 72 73, 74, a pressing plate 81, and a lens barrel base 82.

First, the shooting state will be described with reference to FIGS. 2 and 3. The first lens group 11, the second lens group 12, the third lens group 13, and the fourth lens group 14 are sequentially arranged from the object side. In addition, a shutter / aperture unit 15 is inserted and disposed between the second lens group 12 and the third lens group 13, and on the image plane side of the fourth lens group 14, a CMOS (complementary metal oxide semiconductor) or A solid-state imaging device 16 configured using a CCD (charge coupled device) or the like is disposed. The first lens group 11 to the fourth lens group 14 constitute a zoom lens having a variable focal length.
The first lens group 11 is composed of one or more lenses, and is fixedly held on the rectilinear cylinder 27 via a first lens holding frame 17 that integrally holds the first lens group 11.
The second lens group 12 is composed of one or more lenses, and a cam follower formed on a second lens holding frame (not clearly shown) that integrally holds the second lens group 12 is shown in FIG. The cam cylinder 26 shown in FIG. 2 is inserted into a slit-like cam groove for the second lens group and engages with the rectilinear groove 25a of the second liner 25, and is supported by the cam cylinder 26 and the second liner 25. Has been. The shutter / aperture unit 15 includes a shutter and an aperture stop, and a cam follower integrally formed with the shutter / aperture unit 15 develops a slit-like cam groove for the shutter / aperture of the cam cylinder 26 shown in FIG. And is engaged with the rectilinear groove 25a of the second liner 25, and is supported by the cam cylinder 26 and the second liner 25.

  As shown in FIGS. 10 and 11, a straight advance groove and a helicoid cam groove along the axial direction are formed on the inner surface of the fixed cylinder of the fixed frame 21, and the helicoid cam groove is shown in FIG. 12. As shown, a helicoid cam follower formed on the outer peripheral surface of the base end portion of the first rotating cylinder 22 is engaged. A key portion that protrudes from the outer periphery of the base end portion of the first liner 23 is engaged with the rectilinear groove of the fixed cylinder of the fixed frame 21. A guide groove is formed along the surface perpendicular to the optical axis on the inner surface of the first rotating cylinder 22, and a follower that is a linear guide member protruding from the outer peripheral surface in the vicinity of the base end portion of the first liner 23. (Or key) is engaged. A linear groove and a helicoid are formed along the optical axis direction on the inner surface of the first liner 23, and the first liner 23 is projected on the outer peripheral surface in the vicinity of the base end portion of the second rotating cylinder 24. An escape groove for inserting the cam follower is formed.

A helicoid is formed on the outer peripheral surface of the base end portion of the second rotating cylinder 24, and is screwed into the helicoid provided on the inner periphery of the first liner 23, and the base end portion of the second rotating cylinder 24 A cam follower projecting on the outer peripheral surface in the vicinity is engaged with a linear groove provided on the inner periphery of the first rotating cylinder 22 through the liner (linear groove) of the first liner 23. A key portion protruding from the outer periphery of the base end portion of the second liner 25 is engaged with the linear groove provided on the inner periphery of the first liner 23. A guide groove is formed along the surface perpendicular to the optical axis on the inner surface of the second rotating cylinder 24, and a follower (or key) that is a linear guide member protruding from the outer peripheral surface of the second liner 25. Is engaged. With such a configuration, the second liner 25 moves integrally with the second rotating cylinder 24 with respect to the movement in the optical axis direction, but the second rotating cylinder relatively moves with respect to the second liner 25. Reference numeral 24 denotes a rotational movement.
The cam cylinder 26 fitted to the inner periphery of the second liner 25 has a locking projection projected on the outer periphery of the base end part fitted and locked to the base end part of the second rotary cylinder 24, so that the second It is designed to rotate integrally with the rotary cylinder 24. A guide groove is formed on the inner surface of the second liner 25 along a surface perpendicular to the optical axis, and a follower (or key) that is a linear guide member protruding from the outer peripheral surface (front side) of the cam cylinder 26 is provided. Is engaged. With such a configuration, the cam cylinder 26 moves integrally with the second liner 25 with respect to the movement in the optical axis direction, but the cam cylinder 26 can relatively rotate with respect to the second liner 25. It is like that.

The rectilinear cylinder 27 is inserted between the second rotary cylinder 24 and the second liner 25 on the base end side, and a cam follower is provided on the outer peripheral surface near the base end of the rectilinear cylinder 27. The cam follower engages with a cam groove formed on the inner peripheral surface of the second rotating cylinder 24, and a rectilinear groove is formed on the inner peripheral surface of the rectilinear cylinder 27 along the axial direction. The key part of the outer peripheral surface of the liner 25 is engaged. A gear portion is formed on the outer periphery of the base end portion of the first rotating cylinder 22, and the driving force of the zoom motor 51 is appropriately transmitted through the gear and rotated, whereby the first lens group 11, The two lens group 12 and the shutter / aperture unit 15 perform a zooming operation in a predetermined manner.
The cam groove of the second rotating cylinder 24 that engages with the cam follower of the rectilinear cylinder 27 is shown expanded in FIG. The cam groove of the cam barrel 26 that engages with the cam follower of the lens holding frame of the second lens group 12 and the cam groove of the cam barrel 26 that engages with the cam follower of the shutter / aperture unit 15 are shown in FIG. . Here, the cam groove of the first liner 23 engaged with the cam follower of the second rotating cylinder 24 and the linear groove of the first liner 23 engaged with the key portion of the second liner 25 are described in detail. Is not shown. 10 and 11 show the rectilinear groove of the fixed frame 21 that engages with the key portion of the first liner 23 of the fixed cylinder portion and the cam groove of the fixed frame 21 that engages with the cam follower of the first rotating cylinder 22. Has been.

That is, generally, the rotating cylinder closest to the outermost fixed cylinder is screwed into the fixed cylinder by the helicoid, and the helicoid moves at a constant speed from the shape. For this reason, in the wide-angle position during which it is gradually driven from the retracted retracted state to the telephoto position via the wide-angle position, it is common that the rotary cylinder is drawn out about halfway. On the other hand, in the above-described configuration, the first rotating cylinder 22 is engaged with the fixed cylinder portion of the fixed frame 21 by a helicoid cam groove instead of simply being screwed into the helicoid, so that the first rotating cylinder 22 can be By driving to the wide angle position, the first rotary cylinder 22 is fully extended to the maximum extension position, and thereafter, the object side end of the cam groove is parallel to the end face of the fixed cylinder as shown in FIGS. In the driving from the wide-angle position to the telephoto position, the first rotating cylinder 22 rotates at a fixed position without moving the rotating cylinder in the optical axis direction.
When the first rotating cylinder 22 moves from the retracted state to the wide-angle position, the first rotating cylinder 22 is first rotated to the object side while rotating, and when reaching the maximum extending position, for example, a photo reflector, photo interrupter or A zoom position reference signal is generated by a zoom position detector including a leaf switch and the like. When this zoom position reference signal is generated, it can be considered that the first rotating cylinder 22 has reached the maximum extended position, so that the retractable lens holding frame, that is, the third lens holding frame 31 in this example, is in the optical axis direction. The approaching operation is started.

Accordingly, the first rotating cylinder 22 and the first liner 23, which are the lens barrels close to the fixed cylinder portion at an early stage of the extending operation, are fully extended, so that the third lens holding frame 31 (to be described later) A space for insertion on the shaft is secured in advance.
As will be described later, the zoom position reference signal is generated as soon as the first rotating cylinder 22 reaches the maximum extension position, and the third lens holding frame 31 is inserted immediately after a space for insertion is secured. Thus, it is possible to minimize the time required for shifting from the retracted state to the wide-angle state when the power is turned on.
The third lens group 13 is held by the third lens holding frame 31. The third lens holding frame 31 holds the third lens group 13 at one end, and the other end can be rotated by a third group main guide shaft 32 substantially parallel to the optical axis of the third lens group 13. The third group main guide shaft 32 is supported so as to be slidable. The third lens holding frame 31 has a position on the optical axis where the third lens group 13 is inserted on the optical axis in the photographing state as shown by a solid line in FIG. 7, and a third position in the retracted state as shown by a broken line in FIG. The third lens group 13 is rotated about the third group main guide shaft 32 between the storage position where the third lens group 13 is retracted from the fixed cylinder portion of the fixed frame 21 to the outside. In this case, in the vicinity of the third lens group 13 on the rotation end side of the third lens holding frame 31, the rotation axis side and the support portion side of the third lens group 13 are parallel to the third group main guide shaft 32. A crank-like bent portion that changes the position in a certain direction is formed, and a stopper 31a and a light shielding piece 31b project from the bent portion substantially in the direction of the rotation end.

  In view of optical performance, in order to increase the focal length on the telephoto side, it is necessary to set the position of the third lens group 13 at the telephoto position to the position closer to the subject side than at the wide angle. However, the movable amount of the third lens holding frame 31 is determined by the restriction of the length in the optical axis direction of the lens barrel in the retracted state. The telephoto side focal length can be made as large as possible by setting the lens holding position of the third lens holding frame 31 closest to the subject. However, the position of the stopper 31a in contact with the third group sub-guide shaft 33 to define the position of the third lens group 13 on the optical axis is set at substantially the same position as the third lens group 13. If this happens, the third group sub-guide shaft 33 becomes longer, and the retracted lens barrel becomes larger. Accordingly, the stopper 31a needs to be installed on the in-focus position side as much as possible. Therefore, the third lens holding frame 31 is formed in a shape having a crank-shaped bent portion. The third lens holding frame 31 may be composed of two parts. In this case, one is a member provided with the crank-shaped bent portion, and the other holds the third lens group 13. It is a member for doing. These two parts are fixed to each other and operate as if they were integrated.

  As shown in FIGS. 4 and 5, in the state where the third lens holding frame 31 is in the retracted position, the female screw member 35 screwed into the third group lead screw 34 is located closest to the image plane side. Further, in this state, with the compression torsion spring 36 being most charged, a moment in the clockwise direction (direction of entering the optical axis) as viewed from the front of the lens barrel is always applied to the third lens holding frame. On the cylindrical outer peripheral surface of the third lens holding frame 31 supported by the main guide shaft 32, a cam portion 31e having a predetermined cam slope on the proximal inner surface of the step portion 31c as shown in FIG. Is formed. When the third group motor 52 is rotated in the clockwise direction in FIG. 6 from this state, the lead screw 34 is rotated in the clockwise direction via the gear mechanism including the gears 71 to 74, and the female screw member 35 is moved along the optical axis direction. Move to the subject side. At this time, due to the moment force from the compression torsion spring 36, the cam portion 31 e is in contact with and engaged with the contact portion 35 a of the female screw member 35, and the third lens holding frame 31 rotates clockwise according to the cam slope. To do. When the female screw member 35 further moves to the subject side, the third lens holding frame 31 further rotates until the light shielding piece 31b moves away from the photo interrupter 37 as the third group position detecting device. From, for example, a reference signal that changes from L (low level) to H (high level) is generated. The position of the third lens group 13 is controlled by the pulse count with reference to the reference signal from the photo interrupter 37.

  When the female screw member 35 further moves to the position B in FIG. 4 from this state, the third lens holding frame 31 further rotates in the clockwise direction, and the stopper 31a, as shown in FIG. The position on the optical axis of the third lens holding frame 31 is defined. This completes the approaching operation in the optical axis direction. The light shielding piece 31b can be detected and confirmed to be in the storage position by shielding the photo interrupter 37 shown in FIG. When the female screw member 35 moves to the position B in FIG. 4, the contact portion 35 a of the female screw member 35 contacts and engages with the front engagement portion 31 d of the step portion 31 c of the third lens holding frame 31. That is, the step portion 31c of the third lens holding frame 31 has a cam portion 31e having a cam slope shape on the base end side, and forms a plane that intersects the third group main guide shaft 32 substantially perpendicularly on the front end side. The front engaging portion 31d has a concave shape with respect to the cylindrical peripheral surface. The third lens holding frame 31 is constantly urged in the rotational direction from the storage position toward the position on the optical axis by a compression torsion spring 36 disposed around the third group main guide shaft 32 and the On the third group main guide shaft 32, it is always urged in the direction from the object side toward the holding plate 81 on the image plane side.

Next, when the female screw member 35 moves from the B position in FIG. 4 to the wide-angle position (W position in FIG. 4), the contact portion 35 a of the female screw member 35 moves to the step portion 31 c of the third lens holding frame 31. Since the front side engaging portion 31d is pressed, the third lens holding frame 31 moves to the subject side along the optical axis direction to the wide angle position.
Further, while the female screw member 35 is located between the position B in FIG. 4 and the telephoto position (position T in FIG. 4), the compression torsion spring 36 moves toward the image plane along the optical axis direction. Since all the gaps generated by the play between the third group lead screw 34, the female screw member 35, and the holding plate 81 and the like are all moved toward the image plane side because they are always pressed, the third group lens The holding frame 31 is designed to ensure positional accuracy in the optical axis direction.
The female screw member 35 is screwed into the third group lead screw 34 disposed substantially in parallel with the optical axis, and the front engaging portion 31d in the step portion 31c of the third lens holding frame 31 described above. Alternatively, in addition to the contact portion 35a that contacts the cam portion 31e, as a rotation stopper for preventing the female screw member 35 from rotating with the rotation of the third group lead screw 34, the fixed cylinder portion of the fixed frame 21 An anti-rotation protrusion 35b that fits and slides in a guide groove that is parallel to the optical axis direction is formed (see FIG. 6).

That is, the female screw member 35 moves forward and backward along the optical axis by the rotation of the third group lead screw 34 because the rotation stop projection 35b is fitted in the guide groove of the fixed frame 21 and is prevented from rotating. It is.
On the other hand, as shown in FIG. 4, while the female screw member 35 moves from the telephoto position T to the retraction start position B through the wide angle position W due to the reverse rotation (counterclockwise rotation) of the third group lead screw 34. Since the contact portion 35a of the female screw member 35 is in contact with and engaged with the front engagement portion 31d of the step portion 31c of the third lens holding frame 31 at the engagement contact surface, the optical axis of the compression torsion spring 36 The third lens holding frame 31 maintains the position on the optical axis restricted by the third group sub-guide shaft 33 from the object side to the image plane side by the upward biasing force and the biasing force toward the image plane side. Move gradually. When the female screw member 35 reaches the retraction start position B, the base end surface 31f of the third lens holding frame 31 comes into contact with the pressing plate 81, the female screw member 35 is separated from the front engaging portion 31d, and the step portion 31c It contacts the cam portion 31e.

As shown in detail in FIG. 4, while the female screw member 35 moves from the retraction start position B to the storage position S on the image plane side (the left side in the drawing), the third lens holding frame 31 is attached to the compression torsion spring 36. Since it is already in contact with the holding plate 81 by the urging in the optical axis direction, the contact portion 35a of the female screw member 35 comes into contact with and engages with the cam portion 31e of the step portion 31c of the third lens holding frame 31, and the cam The third lens holding frame 31 is retracted from the position on the optical axis in the counterclockwise direction against the rotational biasing force of the third lens holding frame 31 in the clockwise direction by the compression torsion spring 36. Rotate to evacuate. The storage position S of the third lens holding frame 31 is a position moved to the image plane side by a predetermined pulse count from the generation position of the storage reference signal by the photo interrupter 37 that changes from H to L. After the third lens holding frame 31 has moved to the storage position S, the first lens group 11, the second lens group 12, and the shutter / aperture unit 15 are allowed to move to the retracted storage position.
In this case, in the storing operation, the fourth lens holding frame 41 first moves to the storing position before the third lens holding frame 31 moves to the storing position. The first storage position of the fourth lens holding frame 41 is a predetermined pulse from the generation of the storage reference signal of the fourth lens holding frame 41 that changes from H to L generated by a fourth group reference detector (not shown). This is the position moved to the image plane side by the count number. After the storage operation of the fourth group lens holding frame 41 is completed, the storage operation of the third lens holding frame 31 is permitted.

  When the third lens holding frame 31 moves to the storage position, a storage reference signal that changes from H to L is generated by the photo interrupter 37 (see FIG. 5), and then the image is moved to the image plane side by a predetermined pulse count. The storage operation of the third lens holding frame 31 is completed by moving. After the storage operation of the third lens holding frame 31 is completed, the first rotary cylinder 22 is retracted, or inward from the first rotary cylinder 22 and the first liner 23, that is, from the base end surfaces thereof. The component located in the front is retracted closer to the image plane than the tip position of the third lens holding frame 31 before being stored, so that it is safe without interference with the third lens holding frame 31. It becomes possible to retract the first rotating cylinder 22 and the like. In the zoom motor 51 configured using a general DC (direct current) motor, the positions of the first rotary cylinder 22 and the like are close to the pinion gear having an encoder shape directly fixed to the output shaft of the zoom motor 51. For example, a count of drive pulses generated by a zoom count detector comprising a photo interrupter 51a can be set. Here, the drive source for moving the first rotary cylinder 22 is a DC motor, and detection of the drive position is achieved by a detector using an encoder and a photo interrupter. It is clear that a similar function can be achieved even if it is replaced with.

  Next, the fourth lens group 14 will be briefly described. The fourth lens group 14 is composed of, for example, a single lens, and functions as a focus lens that performs a focusing operation by moving along the optical axis direction. For the holding drive of the fourth lens group 14, for example, a configuration similar to the configuration related to the straight movement along the optical axis direction in the holding drive configuration related to the third lens group 13 can be used. That is, the third lens holding frame 31, the third group main guide shaft 32, the third group sub guide shaft 33, the third group lead screw 34, the third group female screw member 35, the compression torsion spring 36, and the third group motor 52 Almost correspondingly, a fourth lens holding frame 41, a fourth group main guide shaft, a fourth group sub guide shaft, a fourth group lead screw, a fourth group female screw member, a compression spring and a fourth group motor 53 are provided. In this case, since the pivoting operation is unnecessary, the fourth lens holding frame 41 having no crank-shaped bent portion is arranged in the optical axis direction by the fourth group main guide shaft and the fourth group sub guide shaft arranged in parallel to the optical axis. The fourth lens holding frame 41 is urged by a compression spring in one direction parallel to the optical axis, and the fourth group lead screw is rotationally driven by the fourth group motor 53. Accordingly, the fourth group female screw member screwed into the fourth group lead screw is driven to move the fourth lens holding frame 41 engaged with the fourth group female screw member against the compression spring. . In this case, in order to drive the fourth lens holding frame 41 in the direction opposite to the driving direction by the fourth group female screw member, it is not particularly necessary to urge the fourth lens holding frame 41 in the rotating direction. A compression torsion spring may be used to remove the looseness.

Conventionally, as shown in FIGS. 4 and 5, the compression torsion spring 36 of the third lens group 13 has a first adhesive portion 36a formed by extending one end on the side of the fixed frame 21 substantially outward in the radial direction. Only one point is fixed to the fixed frame 21 with an adhesive or the like. In this state, the compression torsion spring 36 is buckled when the third lens holding frame 31 is extended from the wide-angle position W in the telephoto position T due to eccentricity during assembly or due to eccentricity caused by the torsional force of the compression torsion spring 36. As a result of the friction between the compression torsion spring 36 and the inner diameter portion 31h by interfering with the inner diameter portion 31h of the third lens holding frame 31, the operation of the third lens holding frame 31 is hindered, resulting in an operation failure. There was a possibility.
Therefore, in the present invention, the structure for fixing the compression torsion spring of the third lens group 13 to the fixed frame 21 is improved, and interference between the compression torsion spring 36 and the inner diameter portion (31h) of the third lens holding frame 31 is prevented. I tried to do it.

Next, referring to FIGS. 13, 14, and 15 for the fixing structure of the third lens group 13 to the fixing frame 21 of the third lens group 13 which is a characteristic part of the lens barrel according to one embodiment of the present invention. To explain.
13 to 15, the third lens group 13, the third lens holding frame 31, the third group main guide shaft 32, the third group lead screw 34, the third group female screw member 35, and the third group, which are the same as conventional ones. In addition to the motor 52, the gears 71, 72, 73, 74 and the press plate 81, a compression torsion spring 91 according to the present invention is provided in place of the conventional compression torsion spring 36, and the fixed frame side press plate 92, the regulation guide shaft. 93 and a positioning shaft 94 are provided.
FIG. 13 is a perspective view of the configuration of the third lens holding frame 31 and its driving operation system as seen from the image plane side. FIG. 14 is a perspective view seen from the object side showing the configuration of the drive operation system in a state where the third lens holding frame 31 is extended to the telephoto position T (a state where the compression torsion spring 91 is most compressed). FIG. 15 is a front view showing the positional relationship between the direction of each force generated from the compression torsion spring 91 and the restriction guide shaft 93 as seen from the image plane side.

In this embodiment, the first fixing portion 91a and the central axis of the compression torsion spring 91 are sandwiched between the end winding portion on one end of the compression torsion spring 91 on the object side (the side fixed to the fixed frame 21), and substantially opposite to each other. A U-shaped bent portion 91b as a second fixing portion is provided on the side, and a third fixing portion is provided at the other end of the compression torsion spring 91, that is, the end winding portion on the image plane side (pressing plate 81 side). is doing. As shown in FIGS. 13 to 15, the compression torsion spring 91 forms the first fixed portion 91 a by extending the end of the end winding portion at one end on the object side outward in the radial direction of the substantially cylindrical coil portion. The U-shaped bent portion 91b is protruded radially outward of the substantially cylindrical coil portion on the opposite side (a direction forming an angle of about 180 degrees) across the central axis of the substantially cylindrical coil portion. Forming. Further, the compression torsion spring 91 forms a third fixing portion 91c by extending the end of the end winding portion at one end on the image plane side outward in the radial direction of the substantially cylindrical coil portion.
The first fixing portion 91a is fixed to the fixed frame side pressing plate 92 that is integrally fixed to the fixed frame 21, for example, by bonding with an adhesive. The U-shaped bent portion 91b is fitted to a positioning shaft 94 projecting from the fixed frame side pressing plate 92 at a position where the U-shaped bent portion 91b does not interfere with the third lens holding frame 31, thereby positioning the U-shaped bent portion 91b. Is regulated and fixed with an adhesive or the like. The third fixing portion 91c is locked and fixed to the third lens holding frame 31 (FIG. 15).

By adopting such a configuration, the U-shaped bent portion 91b that is the second fixed portion can more reliably position the compression torsion spring 91, and the position reference of the compression torsion spring 91 can be clarified. it can. Therefore, assembly work can be performed easily and stably. Further, with such a configuration, it is possible to easily fix the adhesive at a position where the third lens holding frame 31 does not interfere with the inner diameter portion of the third lens holding frame 31 when extended. The guide shaft 32 can be smoothly moved to the forefront, and the assembly stability can be improved without increasing the thickness dimension of the lens barrel.
Further, the fixed frame side holding plate 92 has two or more turns of the compression torsion spring 91 (that is, at least excluding the end winding) in the direction opposite to the resultant force of the torsional force generated by the U-shaped bent portion 91b and the third fixed portion 91c. A regulating guide shaft 93 is disposed so as to protrude in a direction parallel to the central axis of the substantially cylindrical coil portion of the compression torsion spring 91 (that is, parallel to the optical axis) so as to abut and lock the outer shape of the first winding). ing.

By adopting such a configuration, two or more turns that are not bonded and fixed in the opposite direction to the resultant force of the torsional force generated in the U-shaped bent portion 91b and the third fixing portion 91c generated by the torsional force of the compression torsion spring 91. It is possible to suppress the buckling force generated at the site from almost the most efficient front. Therefore, when the third lens holding frame 31 is driven from the wide-angle position W to the telephoto position T, the compression torsion spring 91 effectively prevents the eccentricity or deviation in the direction in which the compression torsion spring 91 interferes with the inner diameter portion 31h of the third lens holding frame 31. The driving stability of the third lens holding frame 31 can be improved.
In the lens barrel described above, the case where the third lens group 13 is a retractable lens retracted from the optical axis has been described, but the fourth lens group 14 may be further retracted from the optical axis. Alternatively, only the fourth lens group may be used as the retracting lens instead of the third lens group. In such a case, the fourth lens group may be held and driven using a configuration substantially similar to the holding and driving configuration for the third lens group described above.

  In the configuration described above, the lens includes a plurality of lenses, a plurality of lens holding frames that hold the lenses, and a lens drive frame that holds and drives the lens holding frames. As at least one of the retracting lenses retracting away from the optical axis of the lens, the retracting lens holding frame that is a lens holding frame for holding the retracting lens is moved to one of the directions in and out of the optical axis of the lens. In the lens barrel comprising: a substantially cylindrical elastic member that urges simultaneously in a direction parallel to the optical axis; and a fixing member that fixes the elastic member, the elastic member has a substantially cylindrical shape. A torsional force is generated by further winding the other end in the winding direction of the compression coil spring while fixing one end of both ends of the compression coil spring. A compression torsion spring that acts as a torsion spring to be driven, wherein the one end of the compression torsion spring is fixed to the fixing member formed to extend outward in the substantially cylindrical shape. And a second fixing portion for fixing the fixing member to the fixing member formed so as to protrude substantially in a U shape in the radial direction in the same winding as the one end portion of the compression torsion spring. With such a configuration, it is easy to manufacture an elastic member that urges as required in relation to driving of the retractable lens holding frame, and it is possible to improve assembly stability and driving operation stability more easily.

Further, in such a lens barrel, the one of the compression torsion springs on the opposite side to the resultant vector direction of the torsional force at the second fixed portion and the torsional force at the other end of the compression torsion spring. For example, a regulation guide which is implanted in the fixing member so as to protrude in parallel with the substantially cylindrical central axis of the compression torsion spring so as to lock at least one outer shape excluding the end winding on the end side. By providing a guide portion such as the shaft 93, the movable position of the elastic member is appropriately restricted to prevent buckling, and the elastic member can be effectively prevented from interfering with the retractable lens holding frame. It is possible to improve the driving stability.
Further, the present invention is not limited to the above-described configuration, and includes a plurality of lenses, a plurality of lens holding frames that hold the lenses, and a lens driving frame that holds and drives the lens holding frames, One of the directions in which a retractable lens holding frame, which is a lens holding frame for holding the retractable lens, is withdrawn / retracted with respect to the optical axis of the lens. And a fixing member for fixing the elastic member, wherein the elastic member has one end thereof. A first fixing portion that protrudes radially outward to be fixed to the fixing member, and protrudes radially outward at a different angular position from the first fixing portion in the substantially cylindrical shape. It may be configured to include a second fixing portion for fixing the member.
If it does in this way, an elastic member can be fixed outside an operation range, and the composition for fixation can be arranged without interfering with an elastic member, and it becomes possible to improve operational stability of an elastic member.

Further, in the lens barrel configured as described above, the fixing member has at least one protrusion, such as a positioning shaft 94, which engages with the second fixing portion and determines the position of the elastic member. You may make it provide. By comprising in this way, the positional relationship of a fixing member and the 2nd fixing part fixed to it becomes clear and accurate, positioning can be performed easily and more stably, and assembly stability is improved. Is possible.
Furthermore, in the lens barrel described above, a plurality of the second fixing portions may be provided, and the first fixing portions and the plurality of second fixing portions may be arranged at equal angles. With such a configuration, it is possible to fix the elastic member at a plurality of positions with equal angles, stabilize the position of the elastic member during operation, and improve driving stability.
The imaging lens may be an imaging device such as a camera provided with the lens barrel configured as described above. Such an imaging apparatus can operate stably with a simple configuration.

The perspective view which looked at the structure relevant to the lens barrel mechanism containing the lens barrel in the retracted storage state which concerns on the lens barrel which concerns on one embodiment of this invention and retracted and accommodated the lens group from the object side. It is. In the lens barrel shown in FIG. 1, the upper half and the lower half of each lens group, the lens holding frame, and various lens barrels in the telephoto lens barrel in the telephoto position state in which the lens group protrudes and in the retracted state are retracted. It is a longitudinal cross-sectional view shown divided into parts. FIG. 1 is a longitudinal cross-sectional view illustrating main portions of a lens group, a lens holding frame, and various lens barrels in a lens barrel in a wide-angle position state in which the lens group in the lens barrel of FIG. FIG. It is a side view which shows the structure of the 3rd lens holding frame and its drive operation system in the lens barrel of FIG. FIG. 6 is a perspective view of the configuration of a third lens holding frame and its driving operation system when using a compression torsion spring as an elastic member having a conventional fixed structure in the lens barrel of FIG. In the lens barrel of FIG. 1, the configuration of the third lens holding frame and its drive system when using a compression torsion spring as an elastic member having a conventional fixed structure in the same manner as in FIG. It is the perspective view seen from a certain object side. FIG. 6 is a front view of a third lens holding frame portion viewed from the object side in order to explain the operation of the third lens holding frame in the lens barrel of FIG. 1. FIG. 4 is a development view schematically showing the shape of a cam groove formed in a second rotating cylinder in the lens barrel of FIG. 1. FIG. 2 is a developed view schematically showing the shape of a cam groove formed in a cam cylinder in the lens barrel of FIG. 1. FIG. 2 is a development view schematically showing cam grooves and key grooves formed in a fixed lens barrel in the lens barrel of FIG. 1 and omitting a helicoid. FIG. 11 is a detailed development view showing a cam groove and a key groove formed in the fixed barrel of FIG. 10 in detail and including a helicoid. FIG. 2 is a perspective view of a first rotating lens barrel that fits into a helicoid of a fixed lens barrel in the lens barrel of FIG. 1. In the lens barrel of FIG. 1, an image plane corresponding to FIG. 5 and showing the configuration of the third lens holding frame and its driving operation system when a compression torsion spring as an elastic member having a fixed structure according to the present invention is used. It is the perspective view seen from the side. In the lens barrel of FIG. 1, when the compression torsion spring is used as the elastic member having the fixed structure according to the present invention, the third lens holding frame is extended to the telephoto position (the compression torsion spring is most compressed). FIG. 14 is a perspective view illustrating a configuration of a third lens holding frame and a driving operation system thereof, as viewed from the object side that is substantially the back side of FIG. 13. It is the front view seen from the object side which shows the positional relationship of the direction of each force which generate | occur | produces from the compression torsion spring at the time of using the compression torsion spring as an elastic member of the fixed structure which concerns on this invention, and a guide shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 1st lens group 12 2nd lens group 13 3rd lens group 14 4th lens group 15 Shutter / aperture unit 16 Solid-state image sensor 17 1st lens holding frame 18 Cover glass 19 Low pass filter 21 Fixed frame 22 1st rotation cylinder 23 1st liner 24 2nd rotary cylinder 25 2nd liner 26 cam cylinder 27 rectilinear cylinder 31 3rd lens holding frame 32 3rd group main guide shaft 33 3rd group sub guide shaft 34 3rd group lead screw 35 1st Group 3 female screw member 37 Group 3 photo interrupter (position detecting device)
41 Fourth lens holding frame 51 Zoom motor 52 Third group motor 53 Fourth group motor 71, 72, 73, 74 Gear 81 Holding plate 82 Lens barrel base 91 Compression torsion spring 92 Fixed frame side holding plate 93 Restriction guide shaft 94 Positioning axis

Claims (5)

A plurality of lenses; a plurality of lens holding frames that hold the lenses; and a lens drive frame that holds and drives the lens holding frames, and at least one of the plurality of lenses is light of the lenses. As the retractable lens that retracts away from the axis, the retractable lens holding frame, which is a lens holding frame that holds the retractable lens, is urged in one of the directions in and out of the optical axis of the lens and simultaneously with the optical axis. In a lens barrel comprising: a substantially cylindrical elastic member that biases in a parallel direction; and a fixing member that fixes the elastic member.
The elastic member is
As a torsion spring that generates a torsion force by further winding the other end in the winding direction of the compression coil spring with one end of the both ends of the compression coil spring having a substantially cylindrical shape fixed. A compression torsion spring to act,
A first fixing portion for fixing the one end portion of the compression torsion spring to the fixing member formed to extend outward in the substantially cylindrical shape;
A second fixing portion for fixing to the fixing member formed in the same winding as the one end portion of the compression torsion spring and projecting in a substantially U shape in the radial direction; Lens barrel to be used.   At least the end winding on the one end side of the compression torsion spring is removed on the opposite side to the resultant vector direction of the torsion force at the second fixing portion and the torsion force at the other end of the compression torsion spring. 2. The guide member according to claim 1, further comprising: a guide portion that protrudes in parallel with the substantially cylindrical central axis of the compression torsion spring so as to lock an outer shape of one or more turns and is implanted in the fixing member. Lens barrel. Wherein the fixing member, a lens barrel according to claim 1 or claim 2, characterized in providing at least one protrusion to determine the position of the elastic member engaged with the second fixing portion. The second provided a plurality of fixing portions, and any one of claims 1 to 3, characterized by comprising arranging the first fixing portion and the plurality of second fixing portions into equal angles 1 The lens barrel according to the item. An imaging apparatus comprising the lens barrel according to any one of claims 1 to 4 as an imaging lens.

Images