JP6050095B2 - Lens barrier mechanism of lens barrel - Google Patents

Description

  The present invention relates to a lens barrier mechanism of a lens barrel.

The retractable lens barrel is generally rotatable around the optical axis and has a cam ring having a cam groove on the peripheral surface, and a front end having a cam projection that supports the front end lens (first group lens) and engages with the cam groove. A lens support frame; a rotation driving unit that rotationally drives the cam ring; and a lens barrier mechanism that is supported by the front end portion of the front end lens support frame and is positioned immediately before the front end lens.
The lens barrier mechanism is relatively rotated between a barrier support member supported by the front end portion of the front lens support frame and having a barrier opening, and a closed position for closing the barrier opening and an open position for opening the barrier opening with respect to the barrier support member. Possible barrier blades, a barrier biasing spring that urges the barrier blades toward the closed position, an allowable rotation position that allows the barrier blades to rotate to the closed position, and an urging force of the barrier blades. A barrier drive member that can be rotated to an open position against an open position, and a drive member biasing spring that urges the barrier drive member to rotate toward the forced open position and has a larger biasing force than the barrier biasing spring And. Further, the barrier urging spring is generally constituted by a torsion coil spring, and one end thereof is locked to the barrier support member and the other end is locked to the barrier blade. On the other hand, the drive member urging spring is constituted by a tension spring made of a coil spring, and one end is locked to the barrier support member in a state facing the outer peripheral side portion (located on the outer peripheral side from the barrier opening) of the barrier support member. In general, the other end is locked to the barrier driving member.

When the lens barrel is in the retracted position, a part of the cam ring engages with the barrier driving member, so that the barrier driving member is held at the rotation allowable position, so that the barrier blade is biased by the barrier biasing spring. Is in the closed position.
If the cam ring is rotated in one direction by the driving force of the rotation driving means when the lens barrel is in the retracted position, the lens barrel moves to the shooting position (extended state), and the cam groove of the cam ring and the cam projection The front lens support frame moves forward according to the engagement relationship. Furthermore, since the part of the cam ring disengages from the barrier drive member, the barrier drive member is rotated to the forced open position by the biasing force of the drive member biasing spring, and the barrier is rotated to the open position to open the barrier opening. Is released.
On the other hand, when the cam ring is reversed in the opposite direction to the one direction by the driving force of the rotation driving means when the lens barrel is at the photographing position, the lens barrel returns to the retracted position. Then, according to the engagement relationship between the cam groove and the cam protrusion, the front end lens support frame moves rearward (initial position), and the part of the cam ring engages with the barrier drive member again to bring the barrier drive member into the rotation allowable position. Thus, the barrier blades are returned to the closed position by the biasing force of the barrier biasing spring.

JP 2001-215559 A JP 2001-290065 A JP 2004-184585 A

The barrier urging spring of the conventional lens barrier mechanism has the smallest spring charge amount (charge angle) when the barrier blade is located at the closed position, and the spring charge amount (charge angle) as the barrier blade moves toward the open position. Increase gradually. Therefore, the urging force generated by the barrier urging spring is minimized when the barrier blade is located at the closed position, and is maximized when the barrier blade is located at the open position.
However, in the lens barrier mechanism in which the biasing force of the barrier biasing spring is maximized when the barrier blade is in the open position, the barrier blade is rotated to the open position when the lens barrel is moved to the photographing position (expanded state). For this purpose, the biasing force of the driving member biasing spring must be increased, and the driving member biasing spring must be enlarged.
However, recent lens barrels tend to reduce the diameter of the entire lens barrel while increasing the size of the barrier aperture, so that the outer peripheral portion of the barrier aperture of the barrier support member is reduced in area (narrower). Therefore, if a large drive member biasing spring is applied to this type of lens barrel, a part of the drive member biasing spring will protrude to the barrier opening side. It is difficult to use a large drive member biasing spring.
On the other hand, if the urging force of the barrier urging spring is reduced in order to use a small-sized (small urging force) driving member urging spring, the barrier opening is closed by the barrier blade located at the closed position. May become unstable.

  The present invention increases the biasing force of the driving member biasing spring that biases the barrier driving member, while the barrier blade can be biased with a strong force toward the closed position by the barrier biasing spring composed of a torsion coil spring. It is an object to provide a lens barrier mechanism of a lens barrel that is not necessary.

The lens barrier mechanism of the lens barrel of the present invention includes a barrier support member that is positioned in front of the front end lens of the lens barrel and is fixed, and a barrier opening of the barrier support member that is supported by the barrier support member. A barrier urging formed of a torsion coil spring that generates a closing direction urging force for rotating the barrier blade toward the closed position and a barrier blade that can rotate between a closed closed position and an open position that opens the barrier opening A spring, a rotation allowable position that is rotatably supported by the barrier support member, and allows the barrier blade to rotate to the closed position; and the barrier biasing spring resists the closing direction biasing force. A barrier drive member that is movable to a forced open position that rotates the blades to the open position and has a spring engaging portion, and the barrier drive provided between the barrier support member and the barrier drive member. A driving member biasing spring having a biasing force larger than the closing direction biasing force, which biases the member toward the forced opening position, and the barrier biasing spring is provided on the barrier support member. A coil portion rotatably supported on a shaft, a first locking portion extending from one end portion of the coil portion and engaging with the barrier blade, and extending from the other end portion of the coil portion and engaging with the spring A direction to reduce the closing direction biasing force in the same direction by the barrier biasing spring as compared with a case where the second locking portion is fixed to the barrier support member. In addition, the spring engaging portion rotates the second locking portion relative to the spring support shaft together with the coil portion.

The charge amount from the free state of the coil portion when positioned at the forced release position may be equal to or less than the charge amount when positioned at the rotation allowable position.
In this case, when the barrier driving member rotates from the rotation permission position to the forcible release position, the spring engagement portion rotates the second locking portion relative to the spring support shaft. The charge amount of the coil portion may be gradually reduced.

  When the barrier drive member is rotatable to an overcharge position that exceeds the forced release position on the side opposite to the rotation allowable position, and the barrier drive member rotates from the rotation allowable position to the overcharge position, The spring engaging portion may gradually increase the charge amount of the coil portion.

According to the lens barrier mechanism of the present invention, when the barrier driving member rotates from the rotation permission position side to the forced release position side, the barrier biasing spring is closed as compared with the case where the second locking portion of the barrier biasing spring is fixed. The spring engaging portion rotates the second locking portion together with the coil portion in a direction to reduce the direction biasing force. Therefore, the biasing force of the barrier biasing spring is increased when the barrier blade is in the closed position, and the biasing force of the barrier biasing spring is decreased (not increased) when the barrier blade is in the open position. Is possible.
Therefore, by reducing the size of the driving member biasing spring, it is possible to reduce the biasing force of the driving member biasing spring (in order to reduce the diameter of the lens barrel while increasing the size of the barrier opening). Even when the outer peripheral portion is reduced in area (narrower), the drive member biasing spring can be provided facing the outer peripheral portion of the barrier support member without protruding to the barrier opening side.
Furthermore, since the biasing force of the barrier biasing spring can be increased when the barrier blade is located at the closed position, the barrier opening can be reliably closed by the barrier blade moved to the closed position.

It is a vertical side view when located in the retracted position of the lens barrel of the first embodiment to which the present invention is applied. It is a vertical side view of the lens barrel when positioned at the wide end position (shooting position). It is a vertical side view of the lens barrel when located at the tele end position (shooting position). It is a disassembled perspective view of a lens barrel. It is the perspective view seen from the front of a barrier drive member. It is a rear view of the lens barrier mechanism before the barrier biasing spring and the driving member biasing spring are locked to the barrier driving member. FIG. 7 is a rear view similar to FIG. 6 when the barrier driving member is rotated from the state of FIG. 6 to bring the spring engaging portion closer to the locking protrusion of the barrier urging spring. It is a rear view similar to FIG. 6 when the latching protrusion of the barrier urging spring is locked to the spring engaging portion. FIG. 9 is a rear view similar to FIG. 6 when the barrier driving member is rotated from the state of FIG. 8 to the forced opening position. The rear view similar to FIG. 6 when the 2nd latching | locking part of a drive member urging | biasing spring is latched by the barrier drive member. It is the perspective view seen from the back of the lens barrier mechanism when a barrier blade | wing is located in a closed position. It is a perspective view similar to FIG. 11 which removes and shows a barrier drive member (and pressed projection). It is the perspective view seen from the back of a lens barrier mechanism when a barrier blade | wing is located in an open position. FIG. 14 is a perspective view similar to FIG. 13 with the barrier drive member removed. It is a rear view of the lens barrier mechanism when the barrier driving member is assembled to the barrier supporting member (the barrier urging spring and the driving member urging spring are not yet locked to the barrier driving member), and FIG. The figure including a member is a figure which abbreviate | omitted the barrier drive member. It is an enlarged view of the part shown by XVI of FIG.15 (b). FIG. 16 is a view similar to FIG. 15 when the lens barrel is located at the retracted position. FIG. 18 is an enlarged view similar to FIG. 16 when in the same state as FIG. 17. FIG. 18 is a view similar to FIG. 15 when the barrier driving member is slightly rotated from the state of FIG. 17 and is positioned at the rotation allowable position. FIG. 20 is an enlarged view similar to FIG. 16 when in the same state as FIG. 19. FIG. 16 is a view similar to FIG. 15 when the lens barrel is positioned at the wide end position (tele end position). FIG. 22 is an enlarged view similar to FIG. 16 when in the same state as FIG. 21. It is a graph which shows the relationship between the rotation angle of a barrier drive member, and the charge angle of a barrier urging | biasing spring. It is a vertical side view when located in the retracted position of the lens barrel of one embodiment to which the present invention is applied. It is a vertical side view of the lens barrel when positioned at the wide end position (shooting position). It is a vertical side view of the lens barrel when located at the tele end position (shooting position). It is a disassembled perspective view of a lens barrel. It is the perspective view seen from the front of a barrier drive member. It is a rear view of a lens barrier mechanism when the barrier urging spring is not locked to the barrier blade and the driving member urging spring is not locked to the barrier driving member. FIG. 30 is a rear view similar to FIG. 29 when the first locking portion of the barrier urging spring is locked to the barrier blade. FIG. 30 is a rear view similar to FIG. 29 when the barrier driving member is rotated from the state of FIG. 30 to the forcible opening position. The rear view similar to FIG. 29 when the 2nd latching | locking part of a drive member urging | biasing spring is latched by the barrier drive member. It is the perspective view seen from the back of the lens barrier mechanism when a barrier blade | wing is located in a closed position. It is the same perspective view as FIG. 33 which removes and shows a barrier drive member. It is the perspective view seen from the back of a lens barrier mechanism when a barrier blade | wing is located in an open position. FIG. 36 is a perspective view similar to FIG. 35 with the barrier drive member removed. Rear surface of the lens barrier mechanism when the barrier driving member is assembled to the barrier supporting member (the barrier biasing spring is not locked to the barrier blade and the driving member biasing spring is not locked to the barrier driving member) FIG. 5A is a diagram including a barrier driving member, and FIG. 5B is a diagram omitting the barrier driving member. It is an enlarged view of the part shown by XXXVIII of FIG.37 (b). It is an enlarged view similar to FIG. 38 when the 2nd latching | locking part of a barrier urging | biasing spring is latched by the barrier blade | wing. FIG. 38 is a view similar to FIG. 37 when the lens barrel is located at the retracted position. It is an enlarged view similar to FIG. 38 when it is in the same state as FIG. FIG. 38 is a view similar to FIG. 37 when the barrier drive member rotates slightly from the state of FIG. 40 and is positioned at the rotation allowable position. It is an enlarged view similar to FIG. 38 when it is in the same state as FIG. It is a figure similar to FIG. 37 when a lens-barrel is located in a wide end position (tele end position). It is an enlarged view similar to FIG. 38 when it is in the same state as FIG. It is a graph which shows the relationship between the rotation angle of a barrier drive member, and the charge angle of a barrier urging | biasing spring.

Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, “front” and “rear” are defined as “front” on the subject side and “rear” on the image plane side (image sensor 12 side), as indicated by the arrows in FIGS. Yes.
The lens barrel 10 of the present embodiment is attached to a camera body CB (see phantom lines in FIGS. 1 to 3). The lens barrel 10 extends forward from a retracted position (position in FIG. 1) accommodated in the camera body CB, so that the lens barrel 10 protrudes forward from the camera body CB through an opening formed in the front surface of the camera body CB. It can be extended to the tele end position (position in FIG. 3) through the end position (position in FIG. 2).

Next, the structure of the lens barrel 10 will be described.
As shown in FIGS. 1 to 4, the lens barrel 10 has a structure including a large number of constituent members. However, in the following description, the lens barrier mechanism 25 and other main members (lens barrier mechanism) which are the main parts of the present invention. Only members related to the operation of 25) will be described, and descriptions of other members will be omitted.
The lens barrel 10 is a lens barrel including a first lens group L1, a second lens group L2, a third lens group L3, and a fourth lens group L4. The lens barrel 10 includes a fixed ring 11 made of two members and fixed to the camera body CB. An imaging element 12 and a motor 14 (see FIG. 4) are fixed to the fixed ring 11. A cam ring 15 that is linked to the motor 14 (indirectly via other members) is provided in front of the fixed ring 11, and a drive member control protrusion 15 a protrudes forward at the front end of the cam ring 15. It is.
The first group frame 20 that supports the first lens group L1 (front end lens) in a fixed state is linked with cam grooves formed on the outer peripheral surface of the cam ring 15 by cam projections fixed to the inner peripheral surface thereof. Further, a cylindrical cover ring 22 is mounted on the outer peripheral surface of the first group frame 20 in a state in which relative rotation is restricted, and a rectilinear guide ring 21 guides the cover ring 22 rectilinearly. Therefore, when the cam ring 15 is rotated while being moved forward by the driving force of the motor 14, the cover ring 22 and the first group frame 20 are moved forward and backward with respect to the fixed ring 11 in conjunction with the rotation operation of the cam ring 15.

A lens barrier mechanism 25 is supported at the front end of the cover ring 22. The lens barrier mechanism 25 includes a barrier support member 26, a first barrier blade 33, a second barrier blade 34, a third barrier blade 35, a barrier driving member 38, a barrier biasing spring 45, a driving member biasing spring 55, and a decorative member. 61 is provided as a component.
The lens barrier mechanism 25 has a barrier support member 26 that fixes its peripheral edge to the front end of the cover ring 22. A substantially rectangular barrier opening 27 is formed as a through hole at the center of the barrier support member 26 made of resin ( which can be made of metal) (the first lens unit L1 shown in FIGS. 1 to 3). The optical axes of the second lens unit L2, the third lens unit L3, and the fourth lens unit L4 pass through the center of the barrier opening 27). On the rear surface of the barrier support member 26, two columnar barrier support shafts 28 project rearwardly in a state of being separated by 180 ° in the circumferential direction. Further, on the rear surface of the barrier support member 26, two barrier biasing spring support shafts 29 and two driving member biasing spring locking projections 30 located in the vicinity of each barrier support shaft 28 are respectively 180 ° in the circumferential direction. It protrudes backward in a separated state.

Each of the barrier support shafts 28 of the barrier support member 26 includes a pair of a first barrier blade 33, a second barrier blade 34, and a third barrier blade 35 made of metal (which may be made of resin). The rotation center hole formed in the end is fitted so as to be rotatable in the order of the third barrier blade 35, the second barrier blade 34, and the first barrier blade 33 (rotation center hole) from the front to the rear. . As shown in the drawing, a link recess 34 a is formed in the outer peripheral surface of the tip of the second barrier blade 34. In addition, a linking projection 34b projects rearward in the vicinity of the rotation center hole of the second barrier blade 34, and a linking projection 35a projects rearward from the tip of the third barrier blade 35. A pressing projection 34c and a pressing projection 35b project rearwardly on the outer peripheral edge near the center of the blade 34 and the third barrier blade 35. Furthermore, a spring hooking recess 33 b is formed at the base end portion of the first barrier blade 33, and a pressed projection 33 c protrudes backward in the vicinity of the base end of the rear surface of the first barrier blade 33.
The first barrier blade 33, the second barrier blade 34, and the third barrier blade 35 located on the upper side are linked to each other, and the first barrier blade 33, the second barrier blade 34, and the third barrier blade 35 located on the lower side. Are linked to each other. Specifically, when the upper and lower first barrier blades 33 are positioned at the closed positions shown in FIGS. 11 and 12, etc., the vicinity of the rotation center hole of the outer peripheral surface of the first barrier blade 33 engages with the linkage protrusion 34b. The second barrier blade 34 is positioned at the closed position (the position shown in FIGS. 11 and 12, etc.), and the third barrier blade 35 is closed while the linkage recess 34a of the second barrier blade 34 is engaged with the linkage projection 35a. (Positions in FIGS. 11 and 12, etc.) On the other hand, when the upper and lower first barrier blades 33 are moved to the open positions shown in FIGS. 13 and 14, the second barrier blades 34 are opened while the outer peripheral surfaces of the first barrier blades 33 are engaged with the pressing protrusions 34c. The third barrier blade 35 is moved to the open position (the position shown in FIGS. 13, 14 and the like) while the outer peripheral surface of the second barrier blade 34 is engaged with the pressing protrusion 35b. Position. When the upper and lower first barrier blades 33, the second barrier blade 34, and the third barrier blade 35 are positioned at the closed position, the barrier openings 27 of the barrier support member 26 are formed on the upper and lower first barrier blades 33, When the second barrier blade 34 and the third barrier blade 35 are completely closed, and the upper and lower first barrier blades 33, the second barrier blade 34, and the third barrier blade 35 are located in the open position, the barrier The barrier opening 27 of the support member 26 is opened.

A photographing light transmitting hole 39 is formed in the central portion of the barrier driving member 38 made of a resin plate (can be made of metal) (the first lens unit L1, shown in FIGS. 1 to 3). The optical axes of the second lens group L2, the third lens group L3, and the fourth lens group L4 pass through the center of the photographing light transmission hole 39). A pair of spring locking projections 40 that are 180 ° apart from each other in the circumferential direction project forward from the front surface of the barrier drive member 38, and one cam ring linking projection 41 faces rearward from the rear surface of the barrier drive member 38. Projected. Further, a pair of barrier link recesses 42 spaced apart by 180 ° in the circumferential direction are provided in front of the barrier drive member 38. Furthermore, spring engagement portions 43 having a triangular front view that are spaced apart from each other by 180 ° in the circumferential direction protrude from two locations on the outer peripheral surface of the barrier drive member 38. Each spring engaging portion 43 includes a locking surface 44 formed of a plane orthogonal to the circumferential direction of the barrier driving member 38.
The barrier drive member 38 is supported so as to be rotatable relative to the rear surface of the barrier support member 26 around the optical axis. A space for positioning the first barrier blade 33, the second barrier blade 34, and the third barrier blade 35 is formed between the barrier support member 26 and the barrier drive member 38. On the other hand, the corresponding pressed protrusions 33c of the first barrier blade 33 are loosely fitted. The barrier drive member 38 can rotate relative to the barrier support member 26 between an overcharge position shown in FIG. 17A and a forced release position shown in FIGS. 13 and 21A. Further, when the barrier driving member 38 rotates from the overcharge position shown in FIG. 17A to the forced release position shown in FIGS. 13 and 21A, the barrier drive member 38 is a position slightly rotated from the overcharge position. It passes the permissible rotation position shown in. When the barrier driving member 38 is located at the overcharge position, the inner surface of the barrier linking recess 42 is separated from the pressed protrusion 33c (see FIGS. 17 and 18), so that force is applied from the barrier driving member 38 to the first barrier blade 33. However, when the barrier driving member 38 moves to the rotation allowable position, the pressed protrusion 33c contacts the inner surface of the barrier link recess 42 (see FIGS. 19 and 20). On the other hand, when the barrier drive member 38 is located at the forced release position, the inner surface of the barrier link recess 42 engages the pressed protrusion 33c (because a rotational force is transmitted from the barrier link recess 42 to the pressed protrusion 33c). The 1st barrier blade | wing 33, the 2nd barrier blade | wing 34, and the 3rd barrier blade | wing 35 are located in an open position.

The pair of barrier biasing springs 45 are metal torsion coil springs (torsion springs), a cylindrical coil portion 46, and a first locking portion 47 and a second locking portion 48 that respectively protrude from both ends of the coil portion 46. And. The distal end portion of the second locking portion 48 is bent, and this bent portion constitutes a locking projection piece 48a extending rearward.
The pair of barrier urging springs 45 attach the coil portion 46 to the barrier urging spring support shaft 29 so as to be rotatable relative to the barrier urging spring support shaft 29, and further attach the first locking portion 47 to the spring engaging recess 33 b of the first barrier blade 33 The coil portion 46 is temporarily fixed to the barrier support member 26 with the coil portion 46 in a free state.
The pair of drive member urging springs 55 are metallic tension springs, and include a cylindrical coil portion 56, and a first locking portion 57 and a second locking portion 58 that protrude from both ends of the coil portion 56, respectively. It has.
The pair of drive member urging springs 55 are disposed in a state of facing the outer peripheral side portion (located on the outer peripheral side of the barrier opening 27) of the barrier support member 26 in the front-rear direction, and the first locking portion 57 is The barrier support member 26 is temporarily fixed to the barrier support member 26 in a state where the coil portion 56 is in a free state by being locked to the corresponding driving member biasing spring locking projection 30 of the barrier support member 26.

The barrier urging spring 45 and the driving member urging spring 55 temporarily fixed to the barrier driving member 38 in this way are completely attached to the lens barrier mechanism 25 by the following procedure.
6, 15, and 16 show the above temporarily fixed state, and the angle formed by the first locking portion 47 and the second locking portion 48 at this time is 49 ° (the charge of the barrier urging spring 45). The angle is 0 ° (see FIG. 16).
First, as shown in FIG. 7, by slightly rotating the barrier driving member 38 in the clockwise direction of FIGS. 6 and 7 from the state of FIG. 6, the spring engagement with the second locking portion 48 of the barrier biasing spring 45 is achieved. The joint part 43 is made to approach.
Next, as shown in FIG. 8, the coil portion 46 is elastically deformed from the free state by rotating the second locking portion 48 in a direction away from the first locking portion 47, and the locking protrusion 48a is spring-loaded. The engagement portion 43 is slidably engaged with the engagement surface 44.
Further, the barrier drive member 38 is rotated in the clockwise direction of FIGS. 8 and 9 from the state of FIG. 8 to move the barrier drive member 38 to the forcibly opened position as shown in FIG. The spring locking projection 40 is brought close to the locking portion 58.
Finally, as shown in FIG. 10, the coil portion 56 is extended from the free state, and the second locking portion 58 is locked to the spring locking protrusion 40.
When the barrier biasing spring 45 and the drive member biasing spring 55 are completely attached to the lens barrier mechanism 25 in this way, the first barrier blade 33, the second barrier blade 34, and the third barrier blade 35 are paired. The urging force of the barrier urging spring 45 tries to move to the closed position. Therefore, when the barrier driving member 38 is located at the overcharge position or the rotation allowable position, the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are closed by the biasing force of the barrier biasing spring 45. It is located in the closed position by the direction biasing force. On the other hand, since the coil portions 56 of the pair of drive member biasing springs 55 are extended from the free state, each drive member biasing spring 55 generates a biasing force in a direction that rotates the barrier driving member 38 in one direction. . The urging force generated by each driving member urging spring 55 is a direction in which the barrier driving member 38 is rotated to the forced opening position, and the urging force is always larger than the closing direction urging force generated by each barrier urging spring 45. . Therefore, when an external force other than the driving member biasing spring 55 is not applied to the barrier driving member 38 (and other than the barrier biasing spring 45 with respect to the first barrier blade 33, the second barrier blade 34, and the third barrier blade 35). When the urging force is not exerted), the barrier driving member 38 is located at the forcibly opened position, and the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are located at the open position.

  An annular decorative member 61 is attached to the front surface of the barrier support member 26.

Next, the operation of the lens barrel 10 will be described.
When the lens barrel 10 is located at the retracted position (the position shown in FIG. 1), the drive member control protrusion 15a of the cam ring 15 located inside the camera body CB engages with the cam ring linkage protrusion 41 of the barrier drive member 38. Thus, the barrier driving member 38 is held at the overcharge position against the biasing force of the driving member biasing spring 55. Therefore, the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are positioned at the closed position by the closing direction biasing force of the barrier biasing spring 45. The barrier opening 27 of the barrier support member 26 is closed by the third barrier blade 35. The angle formed by the first locking portion 47 and the second locking portion 48 at this time is 120 °, and the charge angle of the coil portion 46 is 71 ° (see FIG. 18). That is, since the coil portion 46 is largely elastically deformed when the barrier urging spring 45 is in a free state (when the angle formed between the first locking portion 47 and the second locking portion 48 is 49 °), at this time The biasing spring 45 (coil portion 46) generates a strong closing direction biasing force. Therefore, each first barrier blade 33, second barrier blade 34, and third barrier blade 35 are held in the closed position with a strong force.
When the main switch (not shown) provided on the camera body CB is turned ON to rotate the motor 14 forward, the lens barrel 10 extends forward from the retracted position, and the lens barrel 10 extends forward to a predetermined position. Occasionally, the barrier drive member 38 that receives a rotational force from the drive member control protrusion 15a starts to rotate in the clockwise direction of FIGS. 15, 17, 19, and 21. When the barrier drive member 38 is rotated by 6.5 ° (see FIG. 18) (clockwise in FIG. 19), the barrier drive member 38 reaches the rotation allowable position shown in FIG. Also at this time, the drive member control protrusion 15a of the cam ring 15 is engaged with the cam ring link protrusion 41 of the barrier drive member 38, and each first barrier blade 33, second barrier blade 34, and third barrier blade 35 are engaged. Is kept in the closed position by the biasing force of the barrier biasing spring 45 in the closing direction. Further, as the barrier driving member 38 rotates, the relative position of the spring engaging portion 43 (locking surface 44) with respect to the barrier biasing spring support shaft 29 (coil portion 46) changes. The angle formed by the first locking portion 47 and the second locking portion 48 is decreased while rotating 46 relative to the barrier biasing spring support shaft 29 (clockwise in FIG. 20). That is, as shown in FIG. 20, the angle formed between the first locking portion 47 and the second locking portion 48 of the barrier biasing spring 45 at this time is 98 °, and the charge angle of the coil portion 46 is 49 °. (See FIG. 20). Although the charge angle of the barrier biasing spring 45 is smaller than when the barrier driving member 38 is located at the overcharge position (the amount of elastic deformation of the coil portion 46 is small), the coil portion 46 is also in this state. Generates (somewhat) strong closing force. Therefore, even in this state, the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are held in the closed position with a strong force. Further, as the barrier driving member 38 rotates from the overcharge position to the rotation allowable position, the spring locking projection 40 approaches the driving member biasing spring locking projection 30, so that the driving member biasing spring 55 (the coil portion 56). ) Is slightly reduced.

When the motor 14 continues to rotate in the forward rotation direction, the lens barrel 10 extends forward to the wide end position shown in FIG. Then, the barrier drive member 38 receiving the rotational force from the drive member control projection 15a of the cam ring 15 rotates to the forcible release position (clockwise in FIG. 21), and each of the first barrier blades 33, the second barrier blades 34, The third barrier blade 35 moves to the open position against the biasing force of the barrier biasing spring 45 in the closing direction. When the barrier driving member 38 is rotated to the forcible opening position, the cam ring linking projection 41 is disengaged from the driving member control projection 15a. The relative position of the spring engaging portion 43 (locking surface 44) with respect to the barrier urging spring support shaft 29 (coil portion 46) further changes with the rotation of the barrier driving member 38 at this time. 45 greatly reduces the charge angle while rotating the coil portion 46 relatively relative to the barrier biasing spring support shaft 29 (clockwise in FIG. 22). That is, the angle formed by the first locking portion 47 and the second locking portion 48 is 82.5 °, and the charge angle of the coil portion 46 is 33.5 ° (see FIG. 22). The amount of elastic deformation of the (coil portion 46) is greatly reduced as compared to when the barrier driving member 38 is located at the rotation allowable position. On the other hand, as the barrier drive member 38 rotates from the rotation allowable position to the forced release position, the spring locking projection 40 comes closer to the driving member biasing spring locking projection 30, so that the driving member biasing spring 55 ( The amount of elastic deformation of the coil portion 56) is also greatly reduced. However, since the biasing force in the closing direction of the barrier biasing spring 45 is small at this time, the biasing force generated by the drive member biasing spring 55 is small (not large. However, the biasing force in the closing direction of the barrier biasing spring 45 is not large. However, the drive member biasing spring 55 (barrier drive member 38) can hold the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 in the open position.
After the lens barrel 10 is moved to the wide end position, when the motor 14 is rotated in the forward rotation direction by operating a zoom switch (not shown) provided in the camera body CB, the lens barrel 10 is shown in FIG. Extends to the tele end position. While the lens barrel 10 moves between the wide end position and the tele end position (whether it expands or shortens), the cam ring linking protrusion 41 and the driving member control protrusion 15a of the barrier driving member 38 remain in a separated state. Thus, the barrier drive member 38 continues to be positioned at the forcibly released position by the biasing force of the drive member biasing spring 55 (the angle formed by the first locking portion 47 and the second locking portion 48 remains 82.5 °). The charge angle of the coil portion 46 remains 33.5 °), and the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 continue to be in the open position.

On the other hand, if the main switch is turned OFF when the lens barrel 10 is located at the photographing position (any position between the tele end position and the wide end position), the motor 14 is reversed. Then, the entire lens barrel 10 is moved toward the retracted position by the rotational driving force of the motor 14, and when the lens barrel 10 is moved past the wide end position, the drive member control protrusion 15a of the cam ring 15 is moved. It re-engages with the cam ring linking projection 41 of the barrier drive member 38. As a result, the rotation of the cam ring 15 causes the barrier drive member 38 to rotate to the rotation allowable position shown in FIG. 19 (counterclockwise in FIG. 19), so that the first barrier blades 33, the second barrier blades 34, and the first The three barrier blades 35 are rotated to the closed position by the biasing force of the barrier biasing spring 45 in the closing direction. Since the relative position of the spring engaging portion 43 (locking surface 44) with respect to the barrier biasing spring support shaft 29 (coil portion 46) changes with the rotation of the barrier driving member 38 at this time, the barrier biasing spring 45 is While the coil portion 46 is rotated relative to the barrier biasing spring support shaft 29 (counterclockwise in FIG. 20), the angle formed by the first locking portion 47 and the second locking portion 48 is expanded to 98 °. The charge angle of the part 46 is increased to 49 °. Further, as the barrier driving member 38 rotates, the spring locking projection 40 is separated from the driving member biasing spring locking projection 30, so that the amount of elastic deformation of the driving member biasing spring 55 (coil portion 56) increases.
When the motor 14 continues to rotate in the reverse direction, the lens barrel 10 moves to the retracted position, and the barrier driving member 38 rotates to the overcharge position shown in FIG. 17 (counterclockwise in FIG. 17). Since the drive member control projection 15a of the cam ring 15 and the cam ring linkage projection 41 of the barrier drive member 38 continue to maintain the engaged state, the first barrier blade 33, the second barrier blade 34, and the third barrier blade 35 are The barrier urging spring 45 is kept in the closed position by the urging force in the closing direction. Since the relative position of the spring engaging portion 43 (locking surface 44) with respect to the barrier biasing spring support shaft 29 (coil portion 46) changes with the rotation of the barrier driving member 38 at this time, the barrier biasing spring 45 is While the coil portion 46 is rotated relative to the barrier biasing spring support shaft 29 (counterclockwise in FIG. 17), the angle formed by the first locking portion 47 and the second locking portion 48 is 120 ° in the initial state. The charge angle is returned to the initial state of 71 °. Further, as the barrier driving member 38 rotates, the spring locking projection 40 is further separated from the driving member biasing spring locking projection 30, so that the amount of elastic deformation of the driving member biasing spring 55 (coil portion 56) further increases. Yes (returns to the initial state).

As described above, in the present embodiment, when the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 move from the closed position to the open position (the barrier driving member 38 is on the rotation allowable position side). The coil portion 46 is rotated around the barrier urging spring support shaft 29. More specifically, the second locking portion 48 is moved to the coil portion in a direction that reduces the closing-direction biasing force as compared with the case where the second locking portion 48 of the barrier biasing spring 45 is fixed to the barrier support member 26. 46 is rotated relative to the barrier urging spring support shaft 29 together with the second locking blade 47 in the same direction as the rotation of the first locking portion 47 accompanying the movement of the first barrier blade 33 toward the open position. Part 48 is rotated). Then, by rotating the second locking portion 48 (coil portion 46) in this way, the charge angle (barrier biasing spring 45) of the coil portion 46 when the barrier driving member 38 rotates from the rotation allowable position to the forced release position. (The amount of charge from the free state of the coil portion 46) is significantly reduced compared to a lens barrier mechanism having a structure in which the second locking portion of the barrier urging spring is fixed to the barrier support member. (See FIG. 23. As shown in FIG. 23, in this embodiment, the charge angle of the coil portion 46 gradually decreases when the barrier drive member 38 rotates from the rotation allowable position to the forced release position). That is, when each of the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are in the closed position (when the barrier driving member 38 is in the overcharge position and the rotation allowable position), While increasing the charge angle (charge amount), each first barrier blade 33, second barrier blade 34, and third barrier blade 35 are located in the open position (the barrier driving member 38 is located in the forced open position). The charge angle (charge amount) of the coil portion 46 is reduced. As a result, when the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are located at the closed positions, the biasing force in the closing direction of the barrier biasing spring 45 is increased. When the second barrier blade 34 and the third barrier blade 35 are located at the open position, the biasing force in the closing direction of the barrier biasing spring 45 is reduced.
Therefore, the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 are driven as compared with the lens barrier mechanism in which the biasing force in the closing direction of the barrier biasing spring 45 is maximized when the first barrier blades 34 and the third barrier blades 35 are located at the open position. Since the member biasing spring 55 having a small biasing force can be used, the drive member biasing spring 55 can be reduced in size. Accordingly, in order to reduce the diameter of the lens barrel 10 while increasing the size of the barrier opening 27, the outer peripheral side portion of the barrier support member 26 (the portion located on the outer peripheral side of the barrier opening 27) is reduced in area (narrowed). In this case, the drive member biasing spring 55 can be disposed in a state of facing the outer peripheral side portion of the barrier support member 26 without protruding to the barrier opening 27 side.
Further, the urging force in the closing direction of the barrier urging spring 45 (charge angle of the coil portion 46) when the barrier driving member 38 is located at the overcharge position is applied to the barrier urging force when the barrier driving member 38 is located at the rotation allowable position. The biasing force in the closing direction of the spring 45 (the charging angle of the coil portion 46) is further increased. Therefore, when the barrier driving member 38 is located at the overcharge position (that is, when the lens barrel 10 is located at the retracted position), each of the first barrier blades 33, the second barrier blades 34, moved to the closed position, And the barrier opening 27 can be reliably closed by the third barrier blade 35.

  Subsequently, a second embodiment of the present invention will be described. Note that the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

The structure of the lens barrel 10 of this embodiment will be described.
As shown in FIGS. 24 to 27, the lens barrel 10 has a structure including a large number of constituent members. In the following description, the lens barrier mechanism 65 and other main members (lens barrier mechanism) that are essential parts of the present invention will be described. Only members related to the operation of 65) will be described, and description of other members will be omitted.

A lens barrier mechanism 65 is supported at the front end of the cover ring 22. The lens barrier mechanism 65 includes a barrier support member 66, a first barrier blade 73, a second barrier blade 74, a third barrier blade 75, a barrier driving member 78, a barrier biasing spring 85, a driving member biasing spring 95, and a decorative member. 101 is provided as a component.
The lens barrier mechanism 65 has a barrier support member 66 that fixes its peripheral edge to the front end of the cover ring 22. A substantially rectangular barrier opening 67 is formed as a through hole in the central portion of the barrier support member 66 made of resin (can be made of metal) (the first lens shown in FIGS. 24 to 26). The optical axes of the group L1, the second lens group L2, the third lens group L3, and the fourth lens group L4 pass through the center of the barrier opening 67). On the rear surface of the barrier support member 66, two columnar barrier support shafts 68 project rearwardly in a state of being separated by 180 ° in the circumferential direction. Further, on the rear surface of the barrier support member 66, two barrier support shafts 69 and two drive member urging spring locking projections 70 located in the vicinity of each barrier support shaft 68 are separated from each other by 180 ° in the circumferential direction. It protrudes backward.

Each of the barrier support shafts 68 of the barrier support member 66 has a pair of a first barrier blade 73, a second barrier blade 74, and a third barrier blade 75 that are made of metal (can be made of resin). The rotation center hole formed in the end is fitted so as to be rotatable in the order of the third barrier blade 75, the second barrier blade 74, and the first barrier blade 73 (rotation center hole) from the front to the rear. . As shown in the drawing, a link recess 74 a is formed in the outer peripheral surface of the tip of the second barrier blade 74. In addition, a linking projection 74 b projects backward in the vicinity of the rotation center hole of the second barrier blade 74 and the third barrier blade 75, and a linking projection 75 a projects rearward from the tip of the third barrier blade 75. A pressing protrusion 74c and a pressing protrusion 75b project rearwardly at the outer peripheral edge near the center of the second barrier blade 74 and the third barrier blade 75. Further, a spring-hanging recess 73 b is formed at the base end portion of the first barrier blade 73, and a pressed projection 73 c projects backward in the vicinity of the base end of the rear surface of the first barrier blade 73.
The first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 located on the upper side are linked to each other, and the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 located on the lower side. Are linked to each other. Specifically, when the upper and lower first barrier blades 73 are positioned at the closed positions shown in FIGS. 34, 35, etc., the vicinity of the rotation center hole of the outer peripheral surface of the first barrier blade 73 engages with the linkage protrusion 74b. The second barrier blade 74 is positioned at the closed position (the position shown in FIGS. 34, 35, etc.), and the third barrier blade 75 is closed while the link recess 74a of the second barrier blade 74 is engaged with the link protrusion 75a. (Positions in FIGS. 34, 35, etc.). On the other hand, when the upper and lower first barrier blades 73 are moved to the open positions shown in FIGS. 36, 37, etc., the second barrier blades 74 are opened while the outer peripheral surfaces of the first barrier blades 73 engage with the pressing protrusions 74c. The third barrier blade 75 is moved to the open position (the position shown in FIGS. 36, 37, etc.) while the outer peripheral surface of the second barrier blade 74 is engaged with the pressing protrusion 75b. Position. When the upper and lower first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 are located at the closed positions, the barrier openings 67 of the barrier support member 66 are formed on the upper and lower first barrier blades 73, When the second barrier blade 74 and the third barrier blade 75 are completely closed, and the upper and lower first barrier blades 73, the second barrier blade 74, and the third barrier blade 75 are in the open position, the barrier The barrier opening 67 of the support member 66 is opened.

An imaging light transmitting hole 79 is formed in the central portion of the barrier driving member 78 made of a resin plate (can be made of metal) (the first lens unit L1, shown in FIGS. 24 to 26). The optical axes of the second lens group L2, the third lens group L3, and the fourth lens group L4 pass through the center of the photographing light transmission hole 79). A pair of spring locking projections 80 that are 180 ° apart from each other in the circumferential direction project forward from the front surface of the barrier drive member 78, and one cam ring linking projection 81 faces rearward from the rear surface of the barrier drive member 78. Projected. Further, a pair of barrier link recesses 82 spaced apart by 180 ° in the circumferential direction are provided in front of the barrier driving member 78. Furthermore, spring control cam grooves 83 having a substantially V shape in front view and spaced apart from each other by 180 ° in the circumferential direction are formed as through grooves at two locations on the barrier drive member 78, respectively. As shown in the drawing, each spring control cam groove 83 includes an assembly region 83a, a storage engagement region 83b (opening / closing region) continuous with one end of the assembly region 83a, and one end (assembly region 83a) of the storage engagement region 83b. And an imaging engagement region 83c (opening / closing region) that is continuous with the end portion on the opposite side. One side surface (side surface far from the optical axis) of the pair of side surfaces extending in the longitudinal direction of each spring control cam groove 83 is slidably engaged with a locking protrusion 88a of a barrier urging spring 85 described later. The spring control cam surface 84 is configured.
The barrier drive member 78 is supported so as to be rotatable relative to the rear surface of the barrier support member 66 around the optical axis. A space for positioning the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 is formed between the barrier support member 66 and the barrier drive member 78. On the other hand, the corresponding pressed protrusions 73c of the first barrier blade 73 are loosely fitted. The barrier drive member 78 can rotate relative to the barrier support member 66 between an assembly position shown in FIG. 37A and a forced release position shown in FIGS. 35 and 44A. When the barrier drive member 78 rotates from the assembly position shown in FIG. 37 (a) to the forced release position shown in FIGS. 35 and 44 (a), the barrier drive member 78 is a position slightly rotated from the assembly position. ) And the rotation allowable position shown in FIG. 42A, which is a position slightly rotated from the storage completion position shown in FIG. 40A. When the barrier drive member 78 is located at the storage completion position, the inner surface of the barrier link recess 82 is separated from the pressed protrusion 73c (see FIG. 41), so that no force is applied from the barrier drive member 78 to the first barrier blade 73. When the barrier driving member 78 moves to the rotation allowable position, the pressed protrusion 73c contacts the inner surface of the barrier link recess 82 (see FIG. 43). On the other hand, as shown in FIG. 45, when the barrier driving member 78 is positioned at the forced release position, the inner surface of the barrier link recess 82 is engaged with the pressed protrusion 73c (from the barrier link recess 82 to the pressed protrusion 73c. Since the rotational force is transmitted), the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 are in the open position.

The pair of barrier urging springs 85 are metal torsion coil springs (torsion springs), a cylindrical coil portion 86, and a first locking portion 87 and a second locking portion 88 that protrude from both ends of the coil portion 86, respectively. And. The distal end portion of the second locking portion 88 is bent, and the bent portion constitutes a locking protrusion 88a extending rearward.
The pair of barrier urging springs 85 are attached to the coil portion 86 so as to be relatively rotatable with respect to the barrier support shaft 69, and the locking protrusion 88 a of the second locking portion 88 is assembled to the assembly region 83 a ( The spring control cam surface 84) is temporarily locked with respect to the barrier drive member 78 in a state where the coil portion 86 is in a free state by being engaged with the end portion (the end portion on the side opposite to the storing engagement region 83b). Stop.
The pair of drive member biasing springs 95 are metal tension springs, and include a cylindrical coil portion 96, and a first locking portion 97 and a second locking portion 98 that protrude from both ends of the coil portion 96, respectively. It has.
The pair of drive member urging springs 95 is disposed in a state of facing the outer peripheral side portion (located on the outer peripheral side of the barrier opening 67) of the barrier support member 66 in the front-rear direction, and the first locking portion 97 is provided. By engaging with the corresponding driving member biasing spring locking projection 70 of the barrier support member 66, the coil portion 96 is temporarily fixed to the barrier support member 66 in a free state.

The barrier biasing spring 85 and the driving member biasing spring 95 temporarily fixed to the barrier support member 66 and the barrier driving member 78 in this way are completely attached to the lens barrier mechanism 65 by the following procedure.
29, 37, and 38 show the above-described temporarily fixed state. At this time, the barrier driving member 78 is located at the assembly position shown in FIG. The angle formed by the two locking portions 88 is 142 ° (the charge angle of the coil portion 86 is 0 °) (see FIGS. 38 and 46).
First, as shown in FIG. 30, the coil portion 86 is freely moved by rotating the first locking portion 87 in the direction away from the second locking portion 88 (the clockwise direction in FIGS. 29 and 30) from the state of FIG. The first locking portion 87 is locked to the spring hooking recess 73b of the first barrier blade 73 by being elastically deformed from the state (see FIG. 39). At this time, the angle formed by the first locking portion 87 and the second locking portion 88 is 183 °, and the charge angle of the coil portion 86 is 41.0 °.
Further, as shown in FIG. 31, when the barrier drive member 78 is rotated clockwise from FIGS. 30 and 31 from the state of FIG. 30 and moved to the forcible release position after passing through the storage completion position and the rotation allowable position, After the projecting piece 88a slides through the assembly area 83a (the spring control cam surface 84) and the engaging engagement area 83b (the spring control cam face 84), the photographing engagement area 83c (the spring control cam face 84) is moved. ) And the spring locking projection 80 approaches the second locking portion 98 of the drive member biasing spring 95 (see FIGS. 32, 44, and 45).
Finally, as shown in FIG. 32, the coil portion 96 is extended from the free state, and the second locking portion 98 is locked to the spring locking protrusion 80.
After the barrier urging spring 85 and the drive member urging spring 95 are completely attached to the lens barrier mechanism 65 in this way, the barrier drive member 78 is moved to any position between the storage completion position and the forced release position. When positioned, the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 try to move to the closed position by the biasing force of the pair of barrier biasing springs 85. Therefore, when the barrier driving member 78 is located at the storage completion position or the rotation allowable position, each of the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 is closed as a biasing force of the barrier biasing spring 85. It is located in the closed position by the direction biasing force. On the other hand, since the coil portions 96 of the pair of driving member biasing springs 95 are extended from the free state, each driving member biasing spring 95 generates a biasing force in a direction that rotates the barrier driving member 78 in one direction. . The urging force generated by each driving member urging spring 95 is a direction in which the barrier driving member 78 is rotated to the forcibly opened position, and (the barrier urging spring 85 and the driving member urging spring 95 are applied to the lens barrier mechanism 65). The urging force of each driving member urging spring 95 (after completely mounting) is always larger than the closing direction urging force generated by each barrier urging spring 85. Therefore, when an external force other than the driving member biasing spring 95 is not exerted on the barrier driving member 78 (and other than the barrier biasing spring 85 with respect to the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75). When the urging force is not exerted, the barrier driving member 78 is located at the forcibly opened position, and the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 are located at the open position.

  Four locations on the rear surface of the decorative member 101 having an annular shape are attached to the front surface of the barrier support member 66.

Next, the operation of the lens barrel 10 will be described.
When the lens barrel 10 is located at the retracted position (position shown in FIG. 24), the drive member control protrusion 15a of the cam ring 15 located inside the camera body CB engages with the cam ring linkage protrusion 81 of the barrier drive member 78. Thus, the barrier driving member 78 is held at the storage completion position against the biasing force of the driving member biasing spring 95. Therefore, the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 are positioned in the closed position by the closing direction biasing force of the barrier biasing spring 85, and the first barrier blades 73, the second barrier blades 74 are , And the third barrier blade 75 closes the barrier opening 67 of the barrier support member 66. At this time, the locking protrusion 88a of the second locking portion 88 is engaged with the central portion of the storage engagement region 83b (the spring control cam surface 84), and the first locking portion 87 and the second locking portion The angle formed by the portion 88 is 214.5 ° (see FIGS. 41 and 46), and the charge angle of the coil portion 86 is 72.5 ° (see FIG. 41). That is, since the coil portion 86 is largely elastically deformed when the barrier urging spring 85 is in a free state (when the angle formed between the first locking portion 87 and the second locking portion 88 is 142 °), at this time The biasing spring 85 (coil portion 86) generates a strong closing direction biasing force. Therefore, each first barrier blade 73, second barrier blade 74, and third barrier blade 75 are held in the closed position with a strong force.
When the main switch (not shown) provided on the camera body CB is turned ON to rotate the motor 14 forward, the lens barrel 10 extends forward from the retracted position, and the lens barrel 10 extends forward to a predetermined position. Occasionally, the barrier drive member 78 receiving the rotational force from the drive member control projection 15a starts to rotate in the clockwise direction of FIGS. 37, 40, 42, and 44. Then, the barrier driving member 78 rotates to the rotation allowable position shown in FIG. 42 (clockwise in FIG. 42). Also at this time, the drive member control protrusion 15a of the cam ring 15 is engaged with the cam ring linkage protrusion 81 of the barrier drive member 78, and the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75. Is kept in the closed position by the biasing force of the barrier biasing spring 85 in the closing direction. Further, since the relative position of the spring control cam groove 83 with respect to the barrier support shaft 69 (coil portion 86) changes with the rotation of the barrier drive member 78, the central portion of the storage engagement region 83b (the spring control cam surface 84 thereof). The engagement protrusion 88a engaged with the engagement portion 83b (the spring control cam surface 84 thereof) is engaged with the end portion on the shooting engagement region 83c side, and the barrier biasing spring 85 is a coil. Although the portion 86 is rotated relative to the barrier support shaft 69 (clockwise in FIG. 43), the angle formed by the first locking portion 87 and the second locking portion 88 (charge angle of the coil portion 86) is as shown in FIG. It becomes the same size as the time (see FIGS. 43 and 46). Further, as the barrier driving member 78 rotates from the storage completion position to the rotation allowable position, the spring locking projection 80 approaches the driving member biasing spring locking projection 70, so that the driving member biasing spring 95 (coil portion 96). ) Is slightly reduced.

When the motor 14 continues to rotate in the forward direction, the lens barrel 10 extends forward to the wide end position shown in FIG. Then, the barrier drive member 78 receiving the rotational force from the drive member control projection 15a of the cam ring 15 rotates to the forcible release position (clockwise in FIG. 44), and each first barrier blade 73, second barrier blade 74, The third barrier blade 75 moves to the open position against the biasing force of the barrier biasing spring 85 in the closing direction. When the barrier driving member 78 is rotated to the forcible opening position, the cam ring linking projection 81 is released from the driving member control projection 15a. The relative position of the spring control cam groove 83 with respect to the barrier support shaft 69 (coil portion 86) further changes with the rotation of the barrier drive member 78 at this time, so that the barrier biasing spring 85 causes the coil portion 86 to move over the barrier support shaft. The angle between the first locking part 87 and the second locking part 88 (charge angle of the coil part 86) is the same as that in FIG. (See FIG. 45). On the other hand, as the barrier driving member 78 is rotated from the rotation allowable position to the forcible opening position, the spring locking projection 80 further approaches the driving member biasing spring locking projection 70, so that the driving member biasing spring 95 ( The amount of elastic deformation of the coil part 96) is greatly reduced. However, since the urging force of the barrier urging spring 85 is not increased at this time, the urging force generated by the drive member urging spring 95 is small (not large) (however, the barrier urging spring 85 is closed). The driving member biasing spring 95 (barrier driving member 78) can hold the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 in the open position.
After the lens barrel 10 has moved to the wide end position, when the motor 14 is rotated in the forward rotation direction by operating a zoom switch (not shown) provided on the camera body CB, the lens barrel 10 is shown in FIG. Extends to the tele end position. While the lens barrel 10 moves between the wide end position and the tele end position (either when the lens barrel 10 is extended or shortened), the cam ring linking projection 81 of the barrier driving member 78 and the driving member control projection 15a remain separated. Therefore, the barrier drive member 78 continues to be positioned at the forced release position by the biasing force of the drive member biasing spring 95 (the angle formed by the first locking portion 87 and the second locking portion 88 remains 214.5 °). The charge angle of the coil portion 86 remains 72.5 °), and the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 continue to be positioned at the open position.

On the other hand, if the main switch is turned OFF when the lens barrel 10 is located at the photographing position (any position between the tele end position and the wide end position), the motor 14 is reversed. Then, the entire lens barrel 10 is moved toward the retracted position by the rotational driving force of the motor 14, and when the lens barrel 10 is moved past the wide end position, the drive member control protrusion 15a of the cam ring 15 is moved. It re-engages with the cam ring linking projection 81 of the barrier drive member 78. As a result, the barrier driving member 78 rotates to the rotation allowable position shown in FIG. 42 (counterclockwise in FIG. 42), so that each first barrier blade 73, second barrier blade 74, and third barrier blade 75 are barriers. The biasing spring 85 rotates to the closed position by the biasing force in the closing direction. Since the relative position of the spring control cam groove 83 with respect to the barrier support shaft 69 (coil portion 86) changes with the rotation of the barrier drive member 78 at this time, the barrier biasing spring 85 causes the coil portion 86 to move to the barrier support shaft 69. In contrast, the angle formed by the first locking portion 87 and the second locking portion 88 remains 214.5 ° relative to (counterclockwise in FIG. 43), and the charge angle of the coil portion 86 is 72.degree. 5 °). Further, as the barrier driving member 78 rotates, the spring locking projection 80 is separated from the driving member biasing spring locking projection 70, so that the amount of elastic deformation of the driving member biasing spring 95 (coil portion 96) increases.
When the motor 14 continues to rotate in the reverse direction, the lens barrel 10 moves to the retracted position, and the barrier driving member 78 rotates to the storage completion position shown in FIG. 40 (counterclockwise in FIG. 40). Since the drive member control projection 15a of the cam ring 15 and the cam ring linkage projection 81 of the barrier drive member 78 continue to maintain the engaged state, the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 The barrier urging spring 85 is kept in the closed position by the urging force in the closing direction. Since the relative position of the spring control cam groove 83 with respect to the barrier support shaft 69 (coil portion 86) changes with the rotation of the barrier drive member 78 at this time, the barrier biasing spring 85 causes the coil portion 86 to move to the barrier support shaft 69. Although the relative rotation (counterclockwise in FIG. 40) is relatively performed, the angle formed by the first locking portion 87 and the second locking portion 88 remains 214.5 °, and the charge angle of the coil portion 86 is 72. It remains at 5 °. Further, as the barrier driving member 78 rotates, the spring locking projection 80 further moves away from the driving member biasing spring locking projection 70, so that the amount of elastic deformation of the driving member biasing spring 95 (coil portion 96) further increases. Yes (returns to the initial state).

As described above, in this embodiment, the barrier urging spring 85 made of a torsion coil spring is rotatably supported on the spring support shaft 69 provided on the barrier support member 66 with its own coil portion 86, and further the barrier drive member 78. , The locking protrusion 88a of the second locking portion 88 is engaged with the assembly region 83a of 83 (spring control cam surface 84) of the barrier driving member 78, and the first locking is performed. The portion 87 can be attached to the barrier support member 66 and the barrier drive member 78 by engaging the first barrier blade 73 (spring hanging recess 73b).
The closing biasing force of the barrier biasing spring 85 when the latching protrusion 88a of the second latching portion 88 engages with the assembly region 83a is such that the second latching portion 88 is engaged with the engaging region 83b. The shape of the spring control cam surface 84 is set so as to be smaller than the biasing force in the closing direction when engaging with the imaging engagement region 83c. Therefore, when the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 can be biased with a strong force toward the closed position by the barrier biasing spring 85 (the barrier driving member 78 is in the rotation allowable position). The barrier urging spring 85 can be easily attached to the first barrier blade 73 and the barrier driving member 78 even when the urging force of the barrier urging spring 85 is increased between the first barrier blade 73 and the barrier driving member 78. .

Further, when each of the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 moves from the closed position to the open position (the barrier driving member 78 rotates from the rotation allowable position side to the forced open position side). Sometimes, the coil portion 86 is rotated around the barrier support shaft 69. More specifically, the second locking portion 88 is coiled in a direction that reduces the closing direction biasing force as compared with the case where the second locking portion 88 of the barrier biasing spring 85 is fixed to the barrier support member 66. 86 together with the barrier urging spring support shaft 69 (two locking portions in the same direction as the rotation of the first locking portion 87 accompanying the movement of the first barrier blade 73 toward the open position). 88). Then, by rotating the second locking portion 88 (coil portion 86) in this way, the charge angle (barrier biasing spring 85) of the coil portion 86 when the barrier drive member 78 rotates from the rotation allowable position to the forced release position. Energizing force in the closing direction of the coil portion 86. The amount of charge of the coil portion 86 from the free state is greatly reduced compared to a lens barrier mechanism having a structure in which the second locking portion of the barrier urging spring is fixed to the barrier support member. (Refer to FIG. 46. As shown in FIG. 46, in this embodiment, the charge angle of the coil portion 86 hardly increases when the barrier drive member 78 rotates from the rotation allowable position to the forced release position, and is substantially constant.) As a result, when the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 are located at the closed positions, the biasing force in the closing direction of the barrier biasing spring 85 is increased, Vane 73, it is possible so as not to unnecessarily large closing direction biasing force of the barrier biasing spring 85 when the second barrier blade 74 and the third barrier blade 75, is located at the open position.
Therefore, the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75 are driven as compared with the lens barrier mechanism in which the biasing force in the closing direction of the barrier biasing spring 85 is maximized when the first barrier blade 73 and the third barrier blade 75 are in the open position. Since the member biasing spring 95 having a small biasing force can be used, the drive member biasing spring 95 can be reduced in size. Accordingly, in order to reduce the diameter of the lens barrel 10 while increasing the size of the barrier opening 67, the outer peripheral portion of the barrier support member 66 (the portion located on the outer peripheral side of the barrier opening 67) is reduced in area (narrowed). In this case, the driving member biasing spring 95 can be disposed in a state of facing the outer peripheral side portion of the barrier support member 66 without protruding to the barrier opening 67 side.
Furthermore, since the urging force of the barrier urging spring 85 can be increased when each of the first barrier blades 73, the second barrier blades 74, and the third barrier blades 75 are positioned at the closed position, The barrier opening 67 can be reliably closed by the first barrier blade 73, the second barrier blade 74, and the third barrier blade 75.

As mentioned above, although this invention was demonstrated using the said embodiment, this invention is not limited to the said embodiment.
For example, in the first embodiment, the center is the center of the barrier support member 26 (the optical axes of the first lens unit L1, the second lens unit L2, the third lens unit L3, and the fourth lens unit L4) and the barrier biasing is performed. The second locking portion 48 is positioned on the outer peripheral side with respect to the circumference passing through the spring support shaft 29, but the barrier biasing spring is positioned so that the second locking portion 48 is positioned on the inner peripheral side of the circumference. 45 may be attached to the barrier support member 26 and the barrier drive member 38. Also in this case, when the first barrier blades 33, the second barrier blades 34, and the third barrier blades 35 move from the closed position to the open position (the barrier driving member 38 moves from the rotation allowable position side to the forced open position side). (When rotating), the second locking portion 48 is moved to the coil portion in a direction that reduces the closing-direction biasing force as compared with the case where the second locking portion 48 of the barrier biasing spring 45 is fixed to the barrier support member 26. 46 together with the barrier biasing spring support shaft 29 (the second locking portion 48 in the same direction as the rotation of the first locking portion 47 accompanying the movement of the first barrier blade 33 toward the open position). ).

Further, although the spring control surface 84 is formed in a part of the spring control cam groove 83 provided in the barrier drive member 78, the spring control surface 84 is formed in a part different from the groove provided in the barrier drive member 78. Alternatively, a part of the groove formed in the barrier driving member 78 does not need to be the spring control surface 84.
Further, when the barrier driving member 78 rotates part or all of the region between the rotation allowable position and the forced release position toward the forced release position, the charge angle (charge amount) of the coil portion 86 is decreased. Thus, the charge angle (charge amount) when the barrier drive member 78 is positioned at the forcible release position may be smaller than the charge angle (charge amount) when the barrier drive member 78 is positioned at the rotation allowable position.

Furthermore, through-holes (linked to the pressed protrusions 33c and 73c) may be formed in the barrier driving members 38 and 78 in place of the barrier linking recesses 42 and 82.
Further, the barrier blades that open and close the barrier opening 27 may be constituted by one or a plurality of barrier blades other than six.
Furthermore, the present invention may be applied to a lens barrel that does not expand and contract in the optical axis direction.

DESCRIPTION OF SYMBOLS 10 Lens barrel 11 Fixed ring 12 Image pick-up element 14 Motor 15 Cam ring 15a Drive member control protrusion 20 1 group frame (lens support frame)
21 Linear guide ring 22 Cover ring 25 Lens barrier mechanism 26 Barrier support member 27 Barrier opening 28 Barrier support shaft 29 Barrier biasing spring support shaft 30 Driving member biasing spring locking projection 33 First barrier blade 33b Spring hooking recess 33c Covered Pressing projection 34 Second barrier blade 34a Linking recess 34b Linking projection 34c Pressing projection 35 Third barrier blade 35a Linking projection 35b Pressing projection 38 Barrier driving member 39 Shooting light transmitting hole 40 Spring locking projection 41 Cam ring connecting projection 42 Barrier coupling recess 43 Spring engaging portion 44 Locking surface 45 Barrier biasing spring 46 Coil portion 47 First locking portion 48 Second locking portion 48a Locking protrusion 55 Drive member biasing spring 56 Coil portion 57 First locking portion 58 Second locking portion 61 Decorative member 65 Lens barrier mechanism 66 Barrier support member 67 Barrier opening 68 Barrier support shaft 69 Barrier support Holding shaft 70 Driving member biasing spring locking projection 73 First barrier blade 73b Spring hooking recess 73c Pressed projection 74 Second barrier blade 74a Linking recess 74b Linking projection 74c Pressing projection 75 Third barrier blade 75a Linking projection 75b Pressing projection 78 Barrier driving member 79 Shooting light transmitting hole 80 Spring locking projection 81 Cam ring linking projection 82 Barrier linking recess 83 Spring control cam groove 83a Assembly area 83b Engagement area (opening / closing area)
83c Shooting engagement area (open / close area)
84 Spring control surface (spring engaging part)
85 Barrier biasing spring 86 Coil portion 87 First locking portion 88 Second locking portion 88a Locking protrusion 95 Drive member biasing spring 96 Coil portion 97 First locking portion 98 Second locking portion 101 Cosmetic member CB Camera body L1 First lens group (front end lens)
L2 Second lens group L3 Third lens group L4 Fourth lens group

Claims (4)

A barrier support member positioned in front of the front end lens of the lens barrel and provided in a fixed state;
A barrier blade supported by the barrier support member and rotatable between a closed position for closing the barrier opening of the barrier support member and an open position for opening the barrier opening;
A barrier biasing spring composed of a torsion coil spring that generates a closing direction biasing force that rotates the barrier blade toward the closed position;
A rotation permission position that is rotatably supported by the barrier support member and allows the barrier blade to rotate to the closed position, and the barrier blade against the biasing force in the closing direction of the barrier biasing spring. A barrier drive member that is movable to a forced open position that rotates to an open position and has a spring engaging portion;
A driving member biasing spring provided between the barrier support member and the barrier driving member, which rotates and biases the barrier driving member toward the forcible opening position, and has a biasing force larger than the closing direction biasing force;
With
A coil portion rotatably supported by a spring support shaft provided on the barrier support member; a first locking portion extending from one end of the coil portion and engaging with the barrier blade; And a second locking portion that extends from the other end of the coil portion and engages with the spring engaging portion,
Compared with the case where the second locking portion is fixed to the barrier support member when the barrier drive member rotates from the rotation permission position side to the forcible release position side, the barrier biasing spring moves in the same direction. The lens of the lens barrel, wherein the spring engaging portion rotates the second locking portion relative to the spring support shaft together with the coil portion in a direction to reduce the closing direction biasing force. Barrier mechanism. In the lens barrier mechanism of the lens barrel according to claim 1,
A lens barrier mechanism of a lens barrel in which a charge amount from a free state of the coil portion when positioned at the forced release position is equal to or less than the charge amount when positioned at the rotation allowable position. In the lens barrier mechanism of the lens barrel according to claim 2,
When the barrier driving member rotates from the rotation permission position to the forcible release position, the spring engagement portion rotates the second locking portion relative to the spring support shaft to thereby rotate the coil portion. Lens barrier mechanism for lens barrel that gradually reduces the amount of charge. In the lens barrier mechanism of the lens barrel according to any one of claims 1 to 3,
The barrier driving member is rotatable to an overcharge position that exceeds the forcible release position on the side opposite to the rotation allowable position;
A lens barrier mechanism for a lens barrel in which the spring engagement portion gradually increases the charge amount of the coil portion when the barrier driving member rotates from the rotation allowable position to the overcharge position.

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