JP2015075656A - Lens barrel and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collapsible lens barrel capable of securing adjustment accuracy in at least one of decentering and inclination without increasing the drive load of a holding member of an optical element and provide an imaging apparatus.SOLUTION: A lens barrel has: a lens frame 4 for holding a lens 5; a first main bar 6b and a second main bar 6a for guiding the lens frame 4; a leaf spring 23 moving in association with the movement of the second main bar 6a; and a wedge member 36 for urging the second main bar 6a with force Fa larger than force Fi urged by the leaf spring 23 to fix a relative position of the second main bar 6a in an optical direction with respect to the first main bar 6b.

Description

  The present invention relates to a lens barrel and an imaging apparatus.

  A retractable lens barrel needs to prevent tilting and misalignment of the lens barrel in order to ensure optical performance during photographing. In Patent Document 1, a holding member that holds an optical element is pressed against a guide shaft in one direction by an urging means, so that both the eccentricity in a plane perpendicular to the optical axis and the inclination with respect to the optical axis are detected. A positioning device that ensures accuracy is proposed.

JP 2010-266582 A

  However, in Patent Document 1, when an external force greater than the spring force is applied to the lens barrel to be held, there is a risk that the lens barrel cannot be held and tilt or misalignment may occur. Further, if the spring force is increased in order to improve the resistance to external force, the driving load for moving the lens becomes high.

  The present invention illustratively provides a retractable lens barrel and an imaging apparatus capable of ensuring at least one adjustment accuracy of eccentricity and inclination without increasing the driving load of the holding member of the optical element. Objective.

  The lens barrel of the present invention is a retractable lens barrel, is configured to be movable in the optical axis direction of the optical element, and holds the optical element. A first guiding portion for guiding, a second guiding portion configured to be movable in the optical axis direction of the optical element with respect to the first guiding portion, and an urging member that moves along with the movement of the second guiding portion; And a wedge member that urges the second guide part with a force larger than the urging force urged by the urging member to fix the relative position of the second guide part with respect to the first guide part. It is characterized by having.

  According to the present invention, it is possible to provide a retractable lens barrel and an imaging apparatus capable of ensuring at least one adjustment accuracy of eccentricity and inclination without increasing the driving load of the holding member of the optical element. .

It is a fragmentary sectional view of the lens barrel of this embodiment in the extended state. FIG. 2 is a partially transparent front view of the lens barrel shown in FIG. 1. It is a fragmentary sectional view of the lens barrel shown in FIG. FIG. 2 is a development view of a fixed cylinder and a cam cylinder shown in FIG. 1. It is a schematic sectional drawing which shows the rectilinear key of the rectilinear cylinder shown in FIG. It is a figure which shows the structure of the wedge member shown in FIG. It is a schematic sectional drawing explaining the retracting operation | movement of the lens-barrel shown in FIG. FIG. 2 is a development view of a fixed barrel and a cam barrel when the lens barrel shown in FIG. 1 is retracted and extended. It is a flowchart which shows the retracting operation | movement of the lens-barrel shown in FIG. It is a flowchart which shows extending operation | movement of the lens-barrel shown in FIG. It is a schematic sectional drawing for demonstrating the effect of FIG.10 (b). It is a graph which shows the example of the amplification factor of the force by a wedge.

  Hereinafter, the lens barrel of this embodiment will be described. The lens barrel houses a photographing optical system that forms an optical image of a subject, and is fixed to an imaging device such as a digital video camera. The imaging apparatus includes an imaging element that photoelectrically converts an optical image formed by the imaging optical system.

  The lens barrel includes a fixed barrel 1, a cam ring 2, a rectilinear barrel 3, a lens frame 4, a lens 5, a first main bar 6b, a second main bar 6a, a sub bar 6c, a feed screw 7, a motor 8, and other members. Have. OA indicated by the alternate long and short dash line is the optical axis of the lens 5.

  FIG. 1 is a schematic cross-sectional view including the optical axis of the photographing optical system of the lens frame 4 of the lens barrel, and shows a state in which the rectilinear cylinder 3 is extended (projected) from the cam ring 2. When the rectilinear cylinder 3 is extended, it is possible to shoot with a high holding accuracy of the lens 5, and this state may be referred to as a “shooting state” hereinafter. On the other hand, the state in which the rectilinear cylinder 3 is retracted (retracted) is a retracted state, which is a non-photographing state or a state where photographing that does not require the holding accuracy of the lens 5 is possible. The left side of FIG. 1 is the subject side, and the right side is the image plane side. This is the same in other sectional views unless otherwise specified. FIG. 1A is a diagram illustrating a state in which the lens frame 4 is extended (a state in which the lens frame 4 is moved), and FIG. 1B is a state in which the lens frame 4 is retracted (a state in which the lens frame 4 is moved to the image side). FIG. Thus, the lens barrel of the present embodiment can be retracted, and the portability is improved by downsizing.

  The fixed cylinder 1 is a fixed member, and a cam ring 2 is provided on the fixed cylinder 1 so as to be rotatable around the optical axis. FIG. 3A is a partial cross-sectional view including the optical axis of the lens barrel in the photographing state. The fixed cylinder 1 has a first main bar (first guide portion, first guide shaft) 6b and a rectilinear groove 11 extending in the optical axis direction.

  The first main bar 6 b has a cylindrical shape made of stainless steel or the like, extends in the optical axis direction, and both ends thereof are held by the fixed cylinder 1. In this embodiment, the guide shaft is used as the guide portion, but a key structure (key and key groove) may be used instead of the shaft.

  As will be described later, in this embodiment, three rectilinear grooves 11 are provided, and a rectilinear key (straight section) 32 is fitted in each, and each rectilinear key 32 moves along the corresponding rectilinear groove 11. One rectilinear key 32 functions as an eccentricity adjusting means, and may be distinguished from the other two rectilinear keys (second rectilinear portion) 32b, 32c as a rectilinear key (first rectilinear portion) 32a, as will be described later. is there. The rectilinear groove 11 into which the rectilinear key 32a is fitted may be distinguished as the first groove and the rectilinear groove 11 into which the rectilinear keys 32b and 32c are fitted as a second groove.

  The cam ring 2 has a substantially cylindrical shape, is provided with a cam groove 21, and rotates by receiving a driving force from a motor (not shown) or the like.

  The rectilinear cylinder 3 has a substantially cylindrical shape and is disposed inside the cam ring 2. The rectilinear cylinder 3 is a rectilinear member, and includes a second main bar 6a as a second guide portion (second guide shaft), a sub bar 6c, and a cam follower 31 that moves along the cam groove of the cam ring 2. When the cam ring 2 rotates with respect to the fixed cylinder 1, the cam follower 31 moves along the cam groove 21, and the rectilinear cylinder 3 moves with respect to the fixed cylinder 1 in the optical axis direction of the lens 5.

  The lens frame 4 is a holding member that holds the lens 5 that is a part of the photographing optical system, and can move in the optical axis direction to change the imaging state of the light beam. The lens 5 is an example of an optical element, but the optical element is not limited to a lens.

  The lens frame 4 has fitting portions 9a and 9b each having a substantially cylindrical hole shape, and is fitted to the second main bar 6a and the first main bar 6b, respectively. The second main bar 6 a and the first main bar 6 b constitute a guide unit that guides the lens frame 4. The fitting portions 9a and 9b have a backlash necessary for sliding with respect to the second main bar 6a and the first main bar 6b and are fitted. For this reason, the lens frame 4 may be tilted relative to the optical axis.

  The fitting portions 9a and 9b are separated by a distance L, and the fitting portion 9a that is the first guided portion is disposed closer to the subject than the fitting portion 9b that is the second guided portion. As the distance L of the lens frame 4 increases, the inclination relative to the optical axis tends to decrease.

  FIG. 2 is a partially transparent front view of the lens barrel as seen from the subject side. As shown in FIG. 2, the fitting portion 9c has a U-shape when viewed from the front, and is engaged with the sub bar 6c. The fitting portion 9c suppresses inclination due to rotation around the axis connecting the lens frame 4 to the fitting portions 9a and 9b. The lens frame 4 also tilts when the relative position between the second main bar 6a and the first main bar 6b changes. That is, in order to reduce the inclination of the lens frame 4, it is important to hold the second main bar 6a and the first main bar 6b so that the relative position between them does not change.

  Each of the second main bar 6a and the sub bar 6c has a cylindrical shape made of stainless steel or the like, extends in a direction parallel to the optical axis, and both ends thereof are held by the rectilinear cylinder 3. The fitting portion 9b as the first guided portion and the fitting portions 9a and 9c as the second guided portion are respectively along the optical axis by the first main bar 6b, the second main bar 6a, and the sub bar 6c. Guided. In FIG. 2, the second main bar 6a is disposed at a position shifted from the radial direction connecting the optical axis and the center of the first main bar 6b, thereby preventing an increase in the radial direction.

  Conventionally, a lens barrel having a single main shaft (main bar) and a sub shaft (sub bar) as a guide shaft for guiding the movement of the holding member of the optical element has not been retracted. In the present embodiment, the main shaft is divided into two parts, a first main bar 6a and a second main bar 6b, so that the main shaft can be retracted and the entire length is shortened in the optical axis direction of the photographing optical system at the time of non-photographing, thereby improving portability. It is increasing.

  However, if one main shaft is divided into two and configured to be relatively movable, a slight gap (backlash) is formed between the two, and if the lens frame 4 moves as it is, eccentricity or tilting will occur. Occurs, and the optical performance of the lens 5 cannot be ensured. Therefore, there is provided locking means for fixing (locking) and releasing (unlocking) the second main bar 6a with respect to the first main bar 6a, and the lens frame 4 is manipulated after being locked by the locking means. The performance is secured.

  The lock means has an eccentricity adjustment means and an inclination adjustment means. The eccentricity adjusting means adjusts the eccentricity of the second main bar 6a with respect to the first main bar 6b in a plane orthogonal to the optical axis of the lens 5. The tilt adjusting means presses the straight cylinder 3 to the fixed cylinder 1 at a plurality of locations (at least two locations, not necessarily in the same plane) in a plane orthogonal to the optical axis. 2 The inclination of the main bar 6a in the optical axis direction is adjusted.

  In Patent Document 1, the eccentricity and the inclination are adjusted by pressing the lens frame on the guide bar at one position, and the lens frame is locked on the guide bar after moving on the guide bar. And since the guide bar is fixed, it cannot retract.

  On the other hand, the inclination adjusting means of this embodiment adjusts the inclination by pressing the rectilinear cylinder 3 against the fixed cylinder 1 in the plane orthogonal to the optical axis, and a component that is long in the optical axis direction is unnecessary. Can be retracted. Here, the rectilinear cylinder 3 is brought into surface contact with the fixed cylinder 1, but the present embodiment is intended to include spherical pressing (point contact) and the like.

  In the present embodiment, when the eccentricity adjusting means acts, a part of the inclination adjusting means acts simultaneously. Further, the power point position of the tilt adjusting means that acts first is closer to the power point position of the eccentricity adjusting means than the power point position of the tilt adjusting means that acts later. For example, the distance between the position of the component force block 37 where the leaf spring 23a applies the force Fc and the position of the linear key 32b where the force Fc acts is the position of the first contact surface 35 where the leaf spring 23b applies the force Fa and the force Fa. Is longer than the distance of the position of the straight key 32b on which is applied. In view of this, the inclination adjustment by the inclination adjustment means is completed after the eccentricity adjustment by the eccentricity adjustment means. Thus, the lens frame 4 is moved in a state where the eccentricity adjustment accuracy and the inclination adjustment accuracy are ensured, and an optical image is formed by the lens 5 to prevent image shake. Further, by using the guide shaft, it is possible to achieve quieter noise than a mechanism that moves the lens only by the cam.

  Next, a moving unit that moves the lens frame 4 back and forth will be described. The motor 8 is fixed to the fixed cylinder 1 and the feed screw 7 is fixed to the output shaft of the motor 8. The rack 41 is attached to the lens frame 4, is rotatable about an axis parallel to the optical axis, and is held so as not to move relative to the lens frame 4 in the optical axis direction. The rack 41 engages with the feed screw 7 and converts the rotation of the feed screw 7 into advance and retreat in the optical axis direction. As a result, the lens frame 4 can be moved back and forth in the optical axis direction by the rotation of the motor 8.

  In FIG. 1A, the lens frame 4 is located closer to the subject. For example, when the lens 5 is a zoom optical element, it can be set to the wide angle side. With the rotation of the motor 8, as shown in FIG. 1 (b), it can move to the far side from the subject and enter the telephoto state. For example, when a stepping motor is used as the motor 8, the number of pulses can be counted, and thus the movement amount of the lens frame 4 can be accurately grasped. It is also possible to calibrate the absolute position of the lens frame 4 with respect to the fixed cylinder 1 by installing a photo interrupter 15 as position detecting means in the fixed cylinder 1 and installing a light shielding wall 45 for position detection in the lens frame 4. It is.

  As shown in FIG. 3A, the fixed cylinder 1 has a bayonet portion 16 for preventing the cam ring 2 from coming off in the optical axis direction. The cam ring 2 is installed so as to be rotatable within a predetermined angle range with respect to the fixed cylinder 1 using a stopper (not shown) or the like.

  A cam groove 21 is disposed on the inner periphery of the cam ring 2, and the cam groove 21 is engaged with a cam follower 31. The cam follower 31 has a convex shape on the outer periphery of the rectilinear cylinder 3. The rectilinear cylinder 3 has a rectilinear key 32 and is engaged with the rectilinear groove 11 of the fixed cylinder 1 to be restricted from rotating around the optical axis. As a result, when the cam ring 2 rotates, the rectilinear cylinder 3 moves forward and backward in the optical axis direction according to the locus of the cam groove 21.

  In the photographing state, the leaf spring 23 that rotates and moves around the optical axis in conjunction with the cam ring 2 bends, and the wedge member 36 as a pressing means is lighted on the plane perpendicular to the optical axis from the vicinity of the inner peripheral surface of the cam ring 2. It is urged by the input urging force Fi toward the axis center. The movement of the leaf spring 23 is not limited to rotation. The wedge member 36 constitutes an eccentricity adjusting means and an inclination adjusting means, and fixes the relative position in the optical axis direction of the second main bar 6a with respect to the first main bar 6b.

The input urging force Fi urges the rectilinear cylinder 3 and the fixed cylinder 1 through the third abutting surface 35 provided on the rectilinear cylinder 3 and the fourth abutting surface 17 provided on the fixed cylinder 1, respectively. The third contact surface 35 receives the lens barrel urging force Fa as a plane substantially orthogonal to the optical axis. The fourth abutting surface 17 is set so that the surface interval becomes narrower toward the third abutting surface 35 in the direction in which the wedge member 36 is urged by the leaf spring 23, and receives Fb. Therefore, the wedge member 36 biased by the leaf spring 23 has the effect of increasing the wedge. That is, the force that biases the third contact surface 35 and the fourth contact surface 17 can be amplified from the input biasing force Fi by the leaf spring 23. For example, when the wedge angle is θw, the lens barrel biasing force Fa of the third contact surface 35 is
Fa = Fi / tan (θw)
It is expressed by the relationship. If θw <45 °, the relationship Fa> Fi is established and the force is amplified. FIG. 12 is a graph showing an example of the force amplification factor due to the wedge.

  The horizontal axis of FIG. 12A represents the wedge angle θw (°), and the vertical axis represents the amplification factor of the lens barrel biasing force Fa with respect to the input biasing force Fi. If this value is 1 or more, it means that the force is amplified. For example, when the angle θw is set to 10 °, the urging force Fa can be increased to 5 or more with respect to the urging force Fi. In this embodiment, the wedge angle θw = 30 °, and the urging force Fa is amplified about 1.7 times.

FIG. 12B shows the relationship of the force depending on the presence / absence of a wedge, and compares the case without a wedge with the case with a wedge. The horizontal axis represents the input biasing force Fi (gf), and the vertical axis represents the lens barrel biasing force Fa (gf). The input biasing force Fi when there is no wedge corresponds to a driving force by a motor or the like, and the lens barrel biasing force Fa corresponds to a force pressing the lens barrel. Since the lens barrel urging force Fa is a force that urges the first contact surface 35, the force that holds the rectilinear barrel 3 increases as the lens barrel urging force Fa increases. Here, if the force necessary to hold the lens barrel is Fa0, the necessary biasing force is Fi1 in the conventional technique, whereas the force necessary when θw = 30 ° of the wedge is Fi2. , Θw = 20 °, the force required is Fi3. Each relationship is
Fi1>Fi3> Fi2
It can be seen that the use of a wedge requires less force than the prior art. Details of the wedge member 36 will be described later.

  In FIG. 3, the rectilinear cylinder 3 urged by the third abutment surface 35 has the rectilinear key 32 abutted against the second abutment surface 12. The second contact surface 12 is a surface that is connected to the rectilinear groove 11 and is orthogonal to the optical axis. Of the second abutment surfaces 12, the second abutment surface 12 that contacts the rectilinear key 32a is distinguished as the first surface, and the second abutment surface 12 that contacts the rectilinear keys 32b and c is distinguished as the second surface. In the present embodiment, the second contact surface 12 is an end surface on the subject side, but may be a surface of a block fixed to the rectilinear groove 11.

  That is, the second abutment surface 12 is compared with FIG. 1 and FIG. 3, near the image plane side end of the second main bar 6 a and the subject side end of the first main bar 6 b when viewed on the optical axis. It is arranged near the part. When the rectilinear key 32 is abutted against the second contact surface 12, the inclination of the rectilinear cylinder 3 with respect to the fixed cylinder 1 can be adjusted. Since the fixed cylinder 1 has the first main bar 6b and the rectilinear cylinder 3 has the second main bar 6a, the relative inclination of the second main bar 6a and the first main bar 6b is also adjusted and kept parallel. Can do. As a result, the holding accuracy of the lens frame 4 in the photographing state can be improved.

  FIG. 4 is a developed view of the circumferential direction of the fixed cylinder 1 and the cam ring 2.

  The fixed cylinder 1 has three rectilinear grooves 11 and is arranged at approximately 120 ° equally. Similarly, three rectilinear keys 32 (in order to distinguish these, 32a to 32c are inserted) in each rectilinear groove 11. As a result, the rectilinear cylinder 3 advances and retreats with respect to the fixed cylinder 1 while keeping the eccentricity with respect to the optical axis within the range of play. Further, the straight key 32 is brought into contact with the second contact surface 12 by the action of the leaf spring 23 (in FIG. 4, shown as 23a to 23c in order to distinguish them) as the inclination adjusting means, thereby adjusting the inclination. ing.

  The cam grooves 21 are arranged at approximately 120 ° equally. In the present embodiment, the cam follower 31 is provided at the same angular position as the rectilinear key 32, but may be provided at a different angular position. In order to avoid interference between the cam groove 21 and the cam follower 31 in the vicinity of the position where the linear key 32 contacts the second contact surface 12, the cam groove 21 has an escape portion 21e. In the locus of the cam groove 21, the position accuracy is improved by setting the backlash of the cam groove 21 and the cam follower 31 to be small while the straight cylinder 3 is being fed. On the other hand, in the shooting state, the relative positional accuracy between the straight cylinder 3 and the fixed cylinder 1 is important, and it is necessary to avoid the interference between the cam groove 21 and the cam follower 31. However, if the cam groove 21 and the cam follower 31 have a large backlash, the escape portion 21e may not be installed.

  Three leaf springs 23 that rotate in conjunction with the cam ring 2 are also provided at substantially the same angular position as the rectilinear key 32. In the present embodiment, the leaf spring 23a and the leaf springs 23b and 23c have different widths in the circumferential direction of the cam ring 2, and the circumferential width d1 of the leaf spring 23a is equal to the width d2 of the leaf springs 23b and 23c, It is wider than d3 (d1> d2≈d3). On the other hand, the three wedge members 36 have the same shape. The leaf spring 23a is an eccentricity adjusting means and is also a part of the inclination adjusting means. The leaf spring 23a serves as both the eccentricity adjusting means and the inclination adjusting means, but the inclination adjustment is completed when the adjustment by the leaf springs 23b and c is completed. Thereby, when shifting from the non-photographing state to the photographing state, the leaf spring 23a starts to bias the wedge member 36 before the leaf springs 23b and 23c. The order of energization will be described later.

  FIG. 3A corresponds to a cross section at the position of the leaf spring 23b or 23c. FIG. 3B shows the cross section at the position of the leaf spring 23a. In FIG. 3B, the third contact surface 35 is provided on a component block 37 having a right triangle shape. The component force block 37 is in contact with the rectilinear cylinder 3 at the fifth contact surface 38 on the inclined surface. The component force block 37 is disposed in the rectilinear groove 11 and has a third contact surface 35, and divides the force received by the third contact surface into a force perpendicular to the optical axis and a force in the optical axis direction. FIG. 3 shows a first position where the wedge member 36 is urged by the leaf spring 23 and contacts the fixed cylinder 1.

  For this reason, the urging force Fi by the leaf spring 23a has components of a force Fa parallel to the optical axis and a force Fc perpendicular to the optical axis and away from the optical axis. Note that a force that balances the force Fc is exerted vertically downward of the component force block 37, but is omitted in FIG. The force Fc acts to decenter the rectilinear cylinder 3 in the direction perpendicular to the optical axis with respect to the fixed cylinder 1.

  FIG. 5 is a view of a plane perpendicular to the optical axis, taken from the subject side, from which the relevant portion of the rectilinear groove 11 and the rectilinear key 32 is extracted from the fixed cylinder 1 and the rectilinear cylinder 3. As shown in FIG. 5, when the force Fc is applied at the position of the rectilinear key 32a, the rectilinear key 32b and the rectilinear key 32c are pressed against the walls (side walls) 11b and 11c, which are the first contact surfaces, respectively ( I'm going to lie down. The eccentricity adjustment is performed by moving one member, but may be performed by moving a plurality of members.

  In this state, if the walls 11b and 11c are processed so that the rectilinear cylinder 3 comes to the center without being eccentric with respect to the fixed cylinder 1, the fixed cylinder 1 and the rectilinear cylinder 3 are affected by the force Fc. It is possible to improve the positional accuracy by adjusting the relative eccentricity. As a result, it leads to improving the space | interval precision of the 1st main bar 6b and the 2nd main bar 6a. That is, by the action of the leaf spring (first urging member) 23a that is the eccentricity adjusting means, the linearly moving keys 32b and 32c are pressed and brought into contact with the walls 11b and 11c that are the first contact surfaces, so that the eccentric position is reached. Is adjusted.

  As described above, the first main bar 6b and the second main bar 6a improve the positional accuracy of both the eccentric direction accuracy orthogonal to the optical axis and the relative parallel accuracy, and high optical accuracy even when the lens frame 4 moves. Can be realized.

  Next, details of the wedge member 36 will be described with reference to FIG.

  FIG. 6A is a perspective view of the wedge member 36. Reference numeral 36 a denotes a protrusion that is urged by the leaf spring 23. Reference numeral 36 b denotes a curved surface (first curved surface) that comes into contact with the rectilinear cylinder 3 at the third contact surface 35. 36 c is a curved surface (second curved surface) that contacts the fixed cylinder 1 at the fourth contact surface 17. Reference numeral 36d denotes a rotation shaft, and the wedge member 36 can rotate around the rectilinear cylinder 3 via the rotation shaft 36d. Instead of providing the rotating shaft 36d in the wedge member 36, a shaft may be provided in the linear cylinder 3 and a through hole through which the shaft passes may be provided in the wedge member 36. A torsion spring 37 is attached to the rotation shaft 36d. The torsion spring 37 functions as a return means for applying a force for returning from the first position shown in FIG. 3 to the second position shown in FIG. 7, but the return means is not limited to the torsion spring 37.

  FIG. 6B is a plan view of the rectilinear cylinder 3 and the wedge member 36. The rotary shaft 36d is loosely constrained so that it cannot move greatly in the optical axis direction with a backlash provided by the rough guide 39 provided in the rectilinear cylinder 3. Thereby, the wedge member 36 can advance and retreat in the optical axis direction together with the rectilinear cylinder 3.

  FIG. 6C is a side view of the rectilinear cylinder 3 and the wedge member 36. The wedge member 36 is acted on by a torsion spring 37 to rotate around the rotation shaft 36d in the direction of the arrow. This rotating force is set to be sufficiently smaller than the urging force Fi by the leaf spring 23. In the photographing state, the wedge member 36 biased by the leaf spring 23 is pressed against the inner peripheral side of the lens barrel. On the contrary, when the urging by the leaf spring 23 is released, the wedge member 36 is rotated to the outer peripheral side by the rotational force of the torsion spring 37.

  The relationship between the 4th contact surface 17 and the 2nd contact surface 12 is demonstrated. In the photographing state, the fourth contact surface 17 is in contact with the wedge member 36. As shown in FIG. 3, the fourth contact surface 17 has a shape in which the rectilinear groove 11 is partially cut away. As shown in FIG. 6B, the region sandwiched between the walls of the rectilinear groove 11 is defined as A. The fourth contact surface 17 is arranged outside the area A in a divided state. Thereby, when the rectilinear cylinder 3 moves forward and backward, the rectilinear key 32 within the range of the area A can pass without interference. On the other hand, as shown in FIG. 6B, the second abutting surface 12 is a surface where the rectilinear key 32 abuts on the fixed cylinder 1, and is therefore disposed in a region sandwiched between the walls of the rectilinear groove 11. Yes. Accordingly, the fourth contact surface 17 and the second contact surface 12 are displaced in the optical axis direction.

  Next, a retracting operation when shifting from the shooting state to the non-shooting state will be described. FIG. 9A is a flowchart when shifting from the shooting state to the non-shooting state, and “S” represents a step. Each step can be embodied as a program for causing a control means (not shown) configured by a microcomputer or the like to realize the function of each step. This is also true for other flowcharts.

  First, in S101, the lens frame 4 is retracted. When the rectilinear cylinder 3 moves to realize the collapse, the rectilinear cylinder 3 moves as shown in FIG. 1B because the movement of the rectilinear cylinder 3 is obstructed if the lens frame 4 is close to the subject. The lens frame 4 is moved to the image plane side before. When the lens frame 4 moves, since the two main bars are locked by the locking means, the lens frame 4 can move smoothly.

  Next, in S102, the rotation of the cam ring 2 is started, and in S103, the urging of the wedge member 36 is released in conjunction with the rotation of the cam ring 2. The details of releasing the bias to the wedge member 36 will be described later.

  FIG. 8 is a development view of the cam ring 2. FIG. 8A shows the photographing state, and the retracting operation sequentially changes from the state shown in FIGS. 8A to 8D. When the urging of the wedge member 36 is released in S103, the state shown in FIG. The cam follower 31 does not move in the optical axis direction. The wedge member 36 is rotated by the torsion spring 37 around the rotation shaft 36d to the outer peripheral side of the lens barrel as indicated by an arrow in FIG. As a result, the state shown in FIG. The protrusion 36 a of the wedge member 36 is inserted into the space of the relief groove 22 of the cam ring 2. As a result, the cam ring 2 and the wedge member 36 overlap when viewed from the optical axis direction. FIG. 7 shows a second position in which the wedge member 36 is not biased by the leaf spring 23 and is separated from the fixed cylinder 1. The wedge member 36 is configured to be rotatable between a first position shown in FIG. 3 and a second position shown in FIG. The movement is not limited to rotation.

  In S104, the cam ring 2 further rotates, the cam follower 31 moves along the cam groove 21, and the rectilinear cylinder 3 moves toward the image plane side.

  In S105, the rectilinear cylinder 3 moves to a predetermined position and the collapsing is completed, and the state shown in FIG. In order to determine that the rectilinear cylinder 3 has moved to a predetermined position, for example, it is possible to count the number of rotations of a motor that uses the cam ring 2 as a rotation drive source. FIG. 7B shows this collapsed state.

  In S106, the rotation of the cam ring 2 is stopped, and the retracting operation is completed.

  The operation of releasing the bias to the wedge member 36 in S103 will be described in detail with reference to FIG.

  In S111, the urging of two of the three wedge members 36 is released. In S111, the state shown in FIG. 8B is reached, and the leaf springs (second urging members) 23b and 23c are changed to a state in which the wedge member 36 is not urged. However, the leaf spring 23a still biases the wedge member 36. As described above, the inclination of the rectilinear cylinder 3 with respect to the fixed cylinder 1 is adjusted by urging the wedge member 36 at three locations in the optical axis direction. That is, the adjustment of the inclination is released by releasing the biasing of the wedge member 36 at two locations.

  In S112, the state shown in FIG. The leaf spring 23a urges the wedge member 36 as described above to adjust the eccentricity of the fixed cylinder 1 and the rectilinear cylinder 3. That is, in the state of FIG. 8C in which the bias of the leaf spring 23a is released, the eccentricity adjustment is released. Thus, the bias of the wedge member 36 is released.

  As described above, the transition from the extended state to the retracted state is completed, and the total length of the lens barrel in the optical axis direction is shortened.

  Conversely, the flow of transition from the retracted state to the extended state will be described. FIG. 10A is a flowchart of the operation from the retracted state to the extended state.

  In S201, the rotation of the cam ring 2 is started. At this stage, the cam groove 21 and the cam follower 31 are in the relationship shown in FIG. In S202, in response to the rotation of the cam ring 2, the rectilinear cylinder 3 starts to be extended. In S203, the cam groove 21 and the cam follower 31 are in the relationship shown in FIG. 8C, and the straight cylinder 3 is extended to the most object side. In S <b> 204, the urging force of the wedge member 36 acts as will be described later, whereby the eccentricity and inclination of the rectilinear cylinder 3 are adjusted with respect to the fixed cylinder 1. In S205, the extended state shown in FIG. 8A is entered, and the rotation of the cam ring 2 is stopped.

  Hereinafter, the urging to the wedge member 36 will be described with reference to FIG.

  In S211, only the leaf spring 23a that adjusts the relative position in the plane orthogonal to the optical axis of the second main bar 6a and the sub bar 6c with respect to the first main bar 6b is attached to the first main bar 6b. It is fast. In this state, the wedge member 36 is urged, and the urging forces Fa and Fc are generated as shown in FIG. In FIG. 5, only the rectilinear key 32 a portion of the rectilinear cylinder 3 is pressed against the second abutting surface 12 with respect to the fixed cylinder 1. The second abutting surface 12 is not pressed against the linearly-moving keys 32b and 32c without generating an urging force. For this reason, the inclination of the rectilinear cylinder 3 with respect to the fixed cylinder 1 is not adjusted, and the rectilinear keys 32b and 32c are not in close contact with the second contact surface 12 and may be slightly separated from each other. On the other hand, the eccentricity is adjusted by pressing the rectilinear keys 32b and 32c against the walls 11b and 11c by Fc.

  In S212, as shown in FIG. 8A, all of the leaf springs 23a, 23b, and 23c, which are inclination adjusting means for adjusting the inclination of the second main bar 6a and the sub bar 6c with respect to the first main bar 6b with respect to the optical axis direction. Is in an energized state. That is, the rectilinear keys 32 a, 32 b, and 32 c are pressed against the second abutting surface 12 at three locations, and the inclination of the rectilinear cylinder 3 is adjusted with respect to the fixed cylinder 1. Thus, after the second main bar 6a and the sub bar 6c, which are the second guide portions, are extended to the subject side, the leaf spring 23a serving as the eccentricity adjusting means and the inclination adjusting means acts, and thereafter the leaf springs 23b and 23c. Completes the tilt adjustment.

  FIG. 11A is a schematic cross-sectional view including the optical axis showing the relationship between the rectilinear key 32 and the second contact surface 12. In S211, as shown by the solid line in FIG. 11A, the forces Fa and Fc act only on the straight key 32a, and in S212, the force Fa also acts on the straight keys 32b and 32c, and the paper moves clockwise. Then, the rectilinear keys 32 b and 32 c are pressed against the second contact surface 12. At this time, since the rectilinear keys 32b and 32c are pressed against the walls 11b and 11c, a frictional force is generated and the pressing against the second contact surface 12 is obstructed.

  However, since the clockwise rotation moves in a direction away from the walls 11b and 11c, the third contact surface 12 can be pressed relatively smoothly. Although FIG. 11 (a) depicts a large amount of movement for the sake of explanation, the actual behavior is that the force Fa acts on the straight key 32a, so that the straight keys 32b and 32c in the operation stage of S211 are operated. The amount of float is very small.

  FIG. 11B illustrates a demerit when the eccentricity adjustment is performed after the inclination adjustment. In this case, as shown by the solid line in FIG. Although the pressing to the second contact surface 12 has been completed, the walls 11b and 11c are not pressed. When the eccentricity adjustment is performed from this state, since the frictional force generated by the pressing on the second contact surface 12 that has already been pressed is generated, the pressing on the walls 11b and 11c is hindered by the force Fc. Requires a force Fc greater than Fa. If the force Fc is insufficient, the accuracy of eccentricity adjustment is insufficient. For this reason, this embodiment is preferable.

  This problem is caused by reducing the frictional force between the second contact surface 12 and the straight key 32 or by making the elastic force of the leaf spring 23a more than twice the elastic force of the leaf springs 23b and c. Can also be solved. However, in this case, it is necessary to create a surface treatment for reducing the frictional force between the second contact surface 12 and the straight key 32 and the leaf spring 23a separately from the leaf springs 23b and c, which makes the manufacturing complicated. It becomes cost rise. For this reason, the structure of this embodiment is preferable.

  As described above, by amplifying the force by the wedge member 36, even if the photographer unintentionally touches the straight cylinder 3 without increasing the driving load of the holding member of the optical element, at least one adjustment accuracy of eccentricity and inclination is adjusted. And the optical performance of the optical element can be maintained.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, A various deformation | transformation and change are possible within the range of the summary.

  The lens barrel of the present invention can be applied to a lens-integrated camera (digital video camera).

4 ... lens frame (holding member), 5 ... lens (optical element), 6b ... first main bar (first guide part), 6a ... second main bar (second guide part), 23 ... leaf spring (biasing) Member), 36 ... wedge member, OA ... optical axis

Claims (11)

A retractable lens barrel,
An optical element;
A holding member configured to be movable in the optical axis direction of the optical element, and holding the optical element;
A first guide for guiding the holding member; a second guide configured to be movable in the optical axis direction of the optical element with respect to the first guide;
An urging member that moves together with the movement of the second guide portion;
A wedge member that urges the second guide portion with a force larger than the urging force urged by the urging member to fix the relative position of the second guide portion with respect to the first guide portion;
A lens barrel comprising: A fixing member provided with the first guide part;
A linear member that includes the second guide part and is movable;
Further comprising
2. The surface on which the wedge member biases the second guide portion and the surface formed on the fixed member and biased by the wedge member are shifted in the optical axis direction. The lens barrel described in 1.   The wedge member is movable between a first position where the wedge member is urged by the urging member to contact the fixing member and a second position which is not urged by the urging member and is away from the fixing member. The lens barrel according to claim 2, wherein the lens barrel is configured as follows. The fixing member further includes a groove extending in the optical axis direction of the lens,
4. The lens barrel according to claim 2, wherein a surface of the wedge member that biases the second guide portion is an end surface of the groove. 5. The fixing member further includes a groove extending in the optical axis direction of the lens,
The lens barrel further includes a component block in which the surface of the wedge member biasing the second guide portion is disposed in the groove,
The component force block fixes the relative position by urging the second guide part with the force in a direction perpendicular to the optical axis and the force received by the surface of the wedge member that urges the second guide part. Divided into forces in the optical axis direction,
The force in a direction perpendicular to the optical axis adjusts the eccentricity of the second guide portion with respect to the first guide portion in a plane orthogonal to the optical axis of the optical element. The lens barrel described in 1. The wedge member is rotatably provided on the rectilinear member,
The lens barrel is
The lens barrel according to claim 3, further comprising return means for applying a force for returning the wedge member from the first position to the second position. A cam ring provided on the fixed member around the optical axis of the optical element, the cam ring being rotatably provided;
The lens barrel according to claim 2, wherein the rectilinear member further includes a cam follower that moves along the cam. A cam ring provided on the fixed member around the optical axis of the optical element, the cam ring being rotatably provided;
The rectilinear member further includes a cam follower that moves along the cam;
The wedge member further includes a protrusion to which the biasing force by the biasing member is applied,
The lens barrel according to claim 3, wherein the cam ring has a groove into which the protrusion is inserted when the wedge member is in the second position.   The said wedge member is further equipped with the 1st curved surface which urges | biases the said 2nd guide part, and the 2nd curved surface which urges | biases the said fixing member, Any one of Claim 2 thru | or 8 characterized by the above-mentioned. The lens barrel described.   10. The holding member further includes a first guided portion guided by the first guiding portion and a second guided portion guided by the second guiding portion. The lens barrel according to any one of the above.   An imaging apparatus comprising the lens barrel according to claim 1.