JP5328233B2 - Barrier device, lens barrel, camera - Google Patents

Description

  The present invention relates to a camera barrier device disposed in front of a photographic lens, a lens barrel including the same, and a camera.

In recent years, cameras have become more convenient and highly functional due to advances in automation and compactness. One of such devices is a barrier device arranged in front of the taking lens, and a system that automatically closes the barrier in the retracted state in conjunction with a zoom mechanism or a retracting mechanism has become mainstream.
In addition, as the size of the camera is further reduced, the lens barrel that holds the photographing lens is becoming smaller in diameter, and it is impossible to cover with the two blade members, and a configuration using four blade members has been developed (for example, Patent Document 1).

  Such a conventional barrier device has two pairs of large and small blade members attached to the front surface of the photographing lens so as to be openable and closable, and barrier driving means for opening and closing the blade members. The blade member is composed of a main blade member and a sub blade member configured to open and close on the same plane substantially orthogonal to the optical axis of the photographing lens, and the sub blade member opens and closes following the movement of the main blade member. It is configured as follows. One spring member that urges each blade member in the closing direction or the opening direction is hung between the main blade member and the sub blade member, and the spring member forms part of the barrier driving means.

The barrier device disclosed in Patent Document 2 includes a spring member that pivotally supports two barrier blades with one shaft and applies a biasing force in the closing direction to each of the two barrier blades. Furthermore, the barrier device of Patent Document 2 includes a ring-shaped barrier driving member provided with cams that open the two barrier blades and the other two barrier blades against the spring force of the spring member. I have.
JP 2001-083575 A JP 2002-148682 A

Incidentally, the barrier device disclosed in Patent Document 1 has two main blade members and two sub blade members, and has a total of four blade members. In such a barrier device, since four blade members and a mechanism for driving them are arranged in a limited space, the degree of freedom in design is small, and there are many cases where it becomes an obstacle to miniaturization.
Moreover, although the engaging part which hangs | hangs a spring in the limited space is provided, if priority is given to size reduction, it will be difficult to devote sufficient space to an engaging part. When the engagement portion is made small, there is a possibility that the engagement portion is deformed or broken due to the biasing force of the spring, and the reliability may be lowered.
Further, in the conventional barrier device, it is necessary to assemble a large number of small parts while applying springs, and the assembling work may be difficult depending on the arrangement of the parts.

An object of the present invention is to provide a small barrier device, a lens barrel, and a camera that have a high degree of design freedom.
The second object of the present invention is to provide a highly reliable barrier device, lens barrel, and camera.
A third object of the present invention is to provide a barrier device, a lens barrel, and a camera that can be easily assembled.

The barrier device according to the first aspect of the present invention includes a first blade member that can be opened and closed to cover the surface of the lens, a second blade member that moves together with the first blade member, and the first blade member. A common engagement portion provided on a member different from the blade member and the second blade member, one end engaged with the common engagement portion, and the other end a first engagement portion of the first blade member A first urging member that applies an urging force to the first blade member by engaging with the first urging member, one end engaged with the common engagement portion with which the first urging member engages, and the other end Has a second biasing member that applies a biasing force to the second blade member by engaging with the second engagement portion of the second blade member . The first urging member and the second urging member include a direction of a urging force received by the common engagement portion by the first urging member and the common engagement by the second urging member. The direction of the urging force received by the part is arranged so as to cancel each other, and the common engagement part, when viewed from the optical axis direction of the lens, is the first engagement part and the second engagement. The common engagement portion is disposed between the first engagement portion and the second engagement member when the first blade member and the second blade member are opened and closed. When the positional relationship with the portion changes and the common engagement portion and the first engagement portion are separated, the common engagement portion and the second engagement portion approach each other, and the common engagement portion and the When the first engagement portion approaches, the common engagement portion and the second engagement portion are separated.

  A lens barrel according to a second aspect of the present invention includes a photographing optical system and a barrier device according to the first aspect of the present invention that is disposed closer to the subject side than the lens of the photographing optical system.

  A camera according to a third aspect of the present invention includes a lens barrel as the second aspect of the present invention and an imaging unit that captures an image obtained by the lens barrel.

  According to the present invention, the degree of design freedom is high, and a small barrier device, a lens barrel, and a camera can be obtained. In addition, the reliability is increased and it can be easily assembled.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of a camera including a lens barrel having a barrier device according to the present invention.
In the following description, a specific shape, configuration, and the like are shown and described, but these can be changed as appropriate.
Also, in each figure, in order to clarify the correspondence of each figure and make it easy to understand, the origin is not specified in particular. As a coordinate system for simply indicating the direction, the upper position when the camera is in the normal position XYZ orthogonal coordinates are provided with Y plus direction. Here, the normal position indicates the posture of the camera in which the optical axis (hereinafter simply referred to as the optical axis) of the photographing optical system of the lens barrel 10 is horizontal and the longitudinal direction of the photographing screen is the horizontal direction. Shall. In the following, the Y plus direction is up, and the Z plus direction (that is, the optical axis subject direction) is the front.
The camera 1 of the present embodiment includes an imaging unit (not shown) inside, and a digital camera in which a lens barrel 10 having a photographing optical system that forms a subject image on the imaging unit is disposed at a substantially center thereof. It is.
The lens barrel 10 is a so-called collapsible lens barrel. When the camera 1 is turned off, the lens barrel 10 is in a retracted state housed in the camera 1 as shown in FIG. In this retracted state, the barrier main blade 22 and the barrier sub blade 23 are in a closed position that covers the first group lens 25 (see FIG. 3), and protects the front surface of the first group lens 25.

FIG. 2 is an exploded perspective view showing an outline of the configuration of the lens barrel 10.
The lens barrel 10 includes a first group cylinder 11, a second group lens holder 12, a cam cylinder 13, a rectilinear guide cylinder 14, a drive cylinder 15, and a fixed cylinder 16.
The first group cylinder 11 holds the first group lens 25 and is disposed on the front end portion of the lens barrel 10 and on the inner peripheral side of the cam cylinder 13 and the rectilinear guide cylinder 14. Further, the first group cylinder 11 has a barrier mechanism including a barrier main blade 22 and a barrier sub blade 23 at its front end. The barrier mechanism of the first group cylinder 11 will be described later.
The second group lens holder 12 holds the second group lens 12 a and is disposed on the Z minus side of the first group cylinder 11 and on the inner peripheral side of the cam cylinder 13 and the rectilinear guide cylinder 14.
The cam cylinder 13 has a plurality of cam grooves and is disposed on the inner peripheral side of the drive cylinder 15 and the fixed cylinder 16.
The rectilinear guide cylinder 14 is disposed on the inner peripheral side of the cam cylinder 13 and restricts the rotation of the first group cylinder 11 and the second group lens holder 12 and guides the moving direction thereof in the direction along the optical axis.
The drive cylinder 15 rotates by obtaining a drive force from a drive source (not shown) and transmits the rotation drive force to the cam cylinder 13.
The fixed cylinder 16 is fixed to the camera 1 and holds the above-described members. The fixed cylinder 16 has a cam groove.

In the operation between the retracted state and the use state and the zoom operation, as described above, the drive cylinder 15 rotates and the rotational driving force is transmitted to the cam cylinder 13. The cam cylinder 13 moves along the optical axis direction while rotating due to the relationship with the cam groove provided in the fixed cylinder 16. The rectilinear guide tube 14 follows the cam tube 13 without rotating and moves along the optical axis direction. The first group cylinder 11 and the second group lens holder 12 move along the optical axis direction without rotating due to the relationship between the cam cylinder 13 and the rectilinear guide cylinder 14.
In addition to the above-described configuration, the lens barrel 10 includes an AF lens group, other drive mechanisms, and the like.

Next, the barrier device provided on the front surface of the first group cylinder 11 will be described.
FIG. 3 is a diagram showing the configuration of the first group cylinder 11 and the barrier device provided therein.
The barrier device includes a barrier driving ring 21, a barrier main blade 22, a barrier sub blade 23, a barrier cover 24, a first lens group 25, an opening spring 26, a main blade closing spring 27, and a sub blade closing spring 28.

  The barrier drive ring 21 rotates in conjunction with the retracting operation and the extending operation of the lens barrel 10. The barrier drive ring 21 is disposed at the front end of the first group cylinder 11 and rotates in conjunction with the rotation of the cam cylinder 13. Further, the barrier drive ring 21 is urged by an opening spring 26 so as to rotate in a direction in which the barrier blades in the figure open (counterclockwise (hereinafter referred to as CCW) in the figure).

  A total of two barrier main blades 22 are arranged one by one at positions where the same shape is point-symmetric about the optical axis. The barrier main blade 22 functions as a first blade member that covers approximately half of the first group lens 25 when closed. The barrier main blade 22 is fitted with a rotation shaft 11a having a fitting hole 22f provided in the first group cylinder 11, and is rotatable about the rotation shaft 11a. Further, the barrier main blade 22 is given a biasing force by the main blade closing spring 27 so as to rotate in the closing direction.

A total of two barrier sub blades 23 are arranged one by one at positions where the same shape is point-symmetric about the optical axis. The barrier sub blade 23 functions as a second blade member that covers a portion of the first lens group 25 that cannot be covered only by the barrier main blade 22 when closed. The barrier sub blade 23 has a fitting hole 23f fitted to the rotating shaft 11b provided in the first group cylinder 11, and is rotatable about the rotating shaft 11b. Further, the barrier sub blade 23 is given a biasing force by the sub blade closing spring 28 so as to rotate in the closing direction.
In this embodiment, two pairs of the barrier main blade 22 and the barrier sub blade 23 that opens and closes following the barrier main blade 22 are provided to cover the entire surface of the first group lens 25.

  The barrier cover 24 is provided at the forefront of the barrier device, restricts the movement of the barrier main blade 22 and the barrier sub blade 23 in the optical axis direction, and forms the external part of the lens barrel 10.

  The first group lens 25 is a lens that forms a photographing optical system together with other lens groups of the lens barrel 10, and is a lens group that is disposed closest to the subject in the photographing optical system.

  The opening spring 26 is a tension coil spring spanned between the first group cylinder 11 and the barrier driving ring 21 and biases the barrier driving ring 21 in the CCW direction (opening direction) in FIG.

  The main blade closing spring 27 is a tension coil spring spanned between the barrier drive ring 21 and the barrier main blade 22 and functions as a first biasing member that biases the barrier main blade 22 in the closing direction. . Two main blade closing springs 27 are provided corresponding to each of the two barrier main blades 22 provided.

  The sub blade closing spring 28 is a tension coil spring that is stretched between the barrier drive ring 21 and the barrier sub blade 23 and functions as a second urging member that urges the barrier sub blade 23 in the closing direction. . Two sub blade closing springs 28 are provided corresponding to each of the two barrier sub blades 23 provided.

FIG. 4 is a view showing the shape of the barrier drive ring 21 in detail.
FIG. 5 is a cross-sectional view showing in detail the shape of the spring hook 21c of the barrier drive ring 21. FIG. FIG. 5 is a cross-sectional view taken along the line BB indicated by an arrow in FIG.
FIG. 6 is a detailed view of the vicinity of the barrier blade rotation axis.
The barrier drive ring 21 is provided with a protrusion 21a, spring hooks 21b and 21c, a contact surface 21d, and rails 21e and 21f.
The protruding portion 21 a protrudes toward the Z minus side so as to abut on the barrier driving portion 13 a of the cam cylinder 13 in order to operate in conjunction with the rotation of the cam cylinder 13. When the barrier drive ring 21 is retracted, the protrusion 21a abuts on the barrier drive portion 13a provided in front of the cam cylinder 13 to obtain a rotational force. The barrier drive ring 21 is rotated in the barrier closing direction (CW direction in FIG. 4) while resisting the opening direction biasing force of the opening spring 26.

One end of the opening spring 26 is engaged with the spring hooking portion 21 b and receives an urging force in the CCW direction from the opening spring 26.
One end of the main blade closing spring 27 is engaged with the spring hooking portion 21 c and receives a biasing force in the CCW direction from the main blade closing spring 27. The spring hooking portion 21 c is engaged with one end of the sub blade closing spring 28 and receives a biasing force in the CW direction from the sub blade closing spring 28. Thus, the spring hooking portion 21c functions as a common engaging portion that engages the two main blade closing springs 27 and the sub blade closing spring 28.

  The spring hook portion 21c has a protrusion 21p and a step 21q for position restriction to the front (Z plus side). Thereby, the main blade closing spring 27 is restricted from moving forward. The sub blade closing spring 28 is restricted from moving forward by the main blade closing spring 27 engaged in front (Z plus side) of the same spring hook 21c.

  The abutting surface 21 d is provided on a groove-like concave side wall portion provided on the front side of the barrier drive ring 21. The contact surface 21d contacts the drive pin 22c of the barrier main blade 21 during the barrier opening operation, whereby the rotational drive of the barrier drive ring 21 is transmitted to the barrier main blade 22 and the barrier is opened.

  The rail portions 21e and 21f regulate the positions of the barrier main blades 22 and the barrier sub blades 23 in the optical axis direction, and guide these operations smoothly.

FIG. 7 is a diagram illustrating a state in which the barrier device is closed. In FIG. 7, the barrier cover 24 is omitted.
FIG. 8 is an enlarged perspective view of the barrier main blade 22 and the barrier sub blade 23 with the barrier device closed.
As shown in FIGS. 6 to 8, the barrier main blade 22 has a spring hooking portion 22e as a first engaging portion with which the main blade closing spring 27 is engaged.
The barrier sub blade 23 has a spring hooking portion 23e as a second engaging portion with which the sub blade closing spring 28 is engaged.
These spring hook portions 22e and 23e are arranged so as to sandwich the spring hook portion 21c provided on the barrier drive ring 21 as a substantial center.
The main blade closing spring 27 has one end engaged with a spring hooking portion 22e serving as a first engaging portion and the other end engaged with a spring hooking portion 21c serving as a common engaging portion. Energized in the closing direction. Similarly, the sub blade closing spring 28 has one end engaged with a spring hook portion 23e serving as a second engagement portion, and the other end engaged with a spring hook portion 21c serving as a common engagement portion. Is energized in the closing direction.

In the present embodiment, the main blade closing spring 27 and the sub blade closing spring 28 are engaged with a spring hooking portion 21c provided integrally on the barrier drive ring 21, so that two spring hooks are provided separately. Space can be used more efficiently.
Further, the spring hooking portions 22e and 23e with which the main blade closing spring 27 and the sub blade closing spring 28 are engaged are arranged so as to sandwich the spring hooking portion 21c provided in the barrier drive ring 21 as a substantially center. With respect to 21c, urging forces act in directions almost opposite to each other. That is, the urging force by the main blade closing spring 27 and the urging force by the sub blade closing spring 28 acting on the spring hooking portion 21c are acting in a direction to cancel each other. Therefore, the resultant force of these urging forces acting on the spring hook 21c does not become a strong force in one direction. Therefore, even if the spring hook portion 21c has a relatively thin shape for miniaturization, the spring hook portion 21c does not fall or bend to one side.

  The spring hook portion 21c moves in a direction approaching the spring hook portion 22e during the process of opening the barrier. On the other hand, during the process of closing the barrier, the spring hook 21c moves in a direction approaching the spring hook 23e. Therefore, in the process of opening and closing the barrier, when one of the two main blade closing springs 27 and the sub blade closing spring 28 expands, the other contracts. When one side shrinks, the other stretches. As a result, the biasing force of the opening spring 26 can be reduced. This will be described later.

Further, as shown in FIG. 8, the barrier main blade 22 and the barrier sub blade 23 have lens shielding portions 22 d and 23 d formed as flat portions covering the surface of the first group lens 25, respectively.
The lens shielding part 22d and the lens shielding part 23d are both arranged on the same plane perpendicular to the optical axis.
FIG. 9 is a cross-sectional view taken along line B-B indicated by an arrow in FIG.
The barrier main blade 22 and the main blade closing spring 27 are arranged such that the positions in the direction along the optical axis overlap. Although not shown, similarly to this, the barrier sub blade 23 and the sub blade closing spring 28 are arranged so that the positions in the direction along the optical axis overlap. Accordingly, the barrier main blade 22 and the main blade closing spring 27, and the barrier sub blade 23 and the sub blade closing spring 28 are overlapped in the direction along the optical axis, and are substantially the same as the optical axis. They are arranged on the same vertical plane. Thereby, the thickness in the optical axis direction can be reduced.

Here, a method for assembling the barrier device of this embodiment will be described.
First, the first group lens 25 is joined to the first group cylinder 11, and the barrier drive ring 21 and the two opening springs 26 are assembled.
Next, the fitting hole 22f of the barrier main blade 22 and the fitting hole 23f of the barrier sub blade 23 are fitted to the rotary shafts 11a and 11b, respectively. Then, the two main blade closing springs 27 and the sub blade closing springs 28 are hooked on the barrier main blade 22 and the barrier sub blade 23, and one end of these springs is hooked on the spring hooking portion 21 b of the barrier driving ring 21.
Finally, the barrier device unit is completed by incorporating the barrier cover 24.
Thus, in this embodiment, since the main blade closing spring 27 and the sub blade closing spring 28 are provided closer to the subject side than the barrier main blade 22 and the barrier sub blade 23, the operation of applying a difficult spring as an assembling operation is performed. Easy to do. Further, all the barrier devices can be assembled in order from the subject side, and the assembling work is easy.

FIG. 10 is a diagram illustrating a state in which the barrier device is open . In FIG. 10, the barrier cover 24 is omitted as in FIG.
Hereinafter, the operation of the barrier device of the present embodiment will be described with reference to FIGS. 7 and 10.
When the lens barrel 10 is in the retracted state, the barrier driving portion 13a of the cam barrel 13 contacts the protrusion 21a of the barrier driving ring 21, and the barrier driving ring 21 is moved in the CW direction against the biasing force of the opening spring 26. The rotated state is maintained. In the state where the barrier drive ring 21 is rotated in the CW direction, the contact surface 21d is in a position where it does not contact the drive pin 22c of the barrier main blade 21 as shown in FIG. Therefore, the barrier main blade 22 does not receive the force in the opening direction from the barrier drive ring 21 and is in the closed state by the biasing force in the closing direction by the main blade closing spring 27. When the barrier device is closed, the mating surfaces 22a of the two barrier main blades 22 are in contact with each other as shown in FIG. Further, the mating surface 22 b of the barrier main blade 22 is in contact with the mating surface 23 b of the barrier sub blade 23. Also in these cases, the four barrier blades are brought into contact with each other by the urging force in the barrier closing direction by the two main blade closing springs 27 and the sub blade closing spring 28, and the closed state is maintained. Also, in this barrier closed state, in order to prevent dust from entering easily and causing inconvenience in the opening and closing operation, even if the barrier device is in the fully closed state, the blades that come into contact with each other are moderately moved in the closing direction. A powerful force is given.

In the process in which the barrier device transitions from the closed state to the open state, the cam barrel 13 holding the closed state rotates in conjunction with the lens barrel feeding operation. As a result, the barrier drive portion 13a of the cam cylinder 13 that is in contact with the protrusion 21a of the barrier drive ring 21 is separated in the direction (CCW) opposite to the direction of contact with the protrusion 21a. At the same time, the barrier drive ring 21 is rotated in the barrier opening direction (CCW) by the biasing force of the opening spring 26. At this time, the concave contact surface 21d of the barrier drive ring 21 contacts the drive pin 22c of the barrier main blade 22. When the contact surface 21d contacts the drive pin 22c, the barrier main blade 22 rotates in the opening direction around the rotation shaft 11a against the biasing force of the main blade closing spring 27 by the biasing force of the opening spring 26. In addition, the barrier sub blade 23 moves so that the abutment surface 23b slides on the abutment surface 22b of the barrier main blade 22 in conjunction with the opening operation of the barrier main vane 22, and is centered on the rotation shaft 11b. Rotate in the opening direction.
At this time, in order to surely switch each barrier blade from the closed state to the open state, the rotational torque in the barrier opening direction by the opening spring 26 is the barrier closing due to the resultant force of the two main blade closing springs 27 and the sub blade closing spring 28. It is essential that it is larger than the rotational torque in the direction.

  On the other hand, the operation from the barrier closed state to the barrier open state is the reverse of the operation from the closed state to the open state. That is, the barrier drive part 13a of the cam cylinder 13 contacts the protrusion 21a of the barrier drive ring 21 and rotates the barrier drive ring 21 in the CW direction against the biasing force of the opening spring 26. When the barrier drive ring 21 rotates in the CW direction, the contact surface 21d moves away from the drive pin 22c of the barrier main blade 21. The barrier main blade 21 is closed by the biasing force of the main blade closing spring 27, and the barrier sub blade 23 is also closed following the main blade closing spring 27 by the biasing force of the sub blade closing spring 28.

Here, in order to compare with the rotational torque of the opening spring and the closing spring of the barrier device of this embodiment, a comparative example will be described first. The comparative example described here is a barrier device having a form close to that of the present embodiment, and the closing spring is continuously charged as the barrier device shifts from the closed state to the open state.
FIG. 11 is a diagram illustrating an example of changes in the rotational torque of the opening spring and the closing spring accompanying the rotation of the barrier drive ring of the comparative example.
As shown in FIG. 11, in the comparative example, during the opening operation, the springs in the closing direction hung on the barrier main blade and the barrier sub blade are both charged, and the load increases. In the barrier open state, the torque in the closing direction by the closing spring is maximized.
On the other hand, as the opening spring for performing the barrier opening operation, a spring that generates a torque that overcomes the torque in the closing direction must be set, and a spring that generates a relatively large force is required. In the example shown in FIG. 11, an opening spring that overcomes the rotational torque of the closing spring is set in all sections of the opening / closing operation. The torque in the opening direction of the opening spring is maximum when the barrier is closed and is minimum when the barrier is open. Therefore, the initial torque T0 by the opening spring in the barrier closed state must be set sufficiently large.

FIG. 12 is a diagram illustrating changes in the rotational torque of the opening spring and the closing spring accompanying the rotation of the barrier drive ring of the present embodiment.
In contrast to the comparative example, in this embodiment, in the process of shifting to the barrier open state, the spring hooking portion 21c at one end of the main blade closing spring 27 rotates and moves together with the barrier opening operation. Therefore, the spring force of the main blade closing spring 27 does not increase in the barrier open state. Further, although the sub blade closing spring 28 is pulled and the spring force increases, the relationship between the rotation center point of the barrier sub blade 23 and the contact point with the barrier main blade 22 and the angle at which the sub blade closing spring 28 is pulled with respect thereto. The amount of increase in rotational torque applied to the sub blade 23 is small. Therefore, as shown in FIG. 12, the resultant torque of the rotation torque by the plurality of main blade closing springs 27 and sub blade closing springs 28 does not become extremely large particularly in the barrier open state, and the resultant torque during the opening / closing operation is a comparative example. Compared and averaged. Therefore, the biasing force of the opening spring 26 that counters this can be set relatively small.

According to this embodiment, since the main blade closing spring 27 and the sub blade closing spring 28 are engaged with the common spring hooking portion 21c, the space can be used more efficiently than when two spring hooks are provided separately. .
Further, the spring hooking portions 22e and 23e with which the main blade closing spring 27 and the sub blade closing spring 28 are engaged are arranged so as to sandwich the spring hooking portion 21c provided in the barrier drive ring 21 as a substantially center. The urging forces act on the 21c in substantially opposite directions, and the spring hooking portion 21c can be made relatively thin.
Further, the barrier main blade 22 and the main blade closing spring 27, and the barrier sub blade 23 and the sub blade closing spring 28 are overlapped in the direction along the optical axis, and are substantially perpendicular to the optical axis. Since it is arranged on the surface, the thickness in the optical axis direction can be reduced.
Furthermore, since the main blade closing spring 27 and the sub blade closing spring 28 are provided closer to the subject than the barrier main blade 22 and the barrier sub blade 23, the assembling work can be easily performed.
In addition, since one of the main blade closing spring 27 and the sub blade closing spring 28 contracts when the other extends, the biasing force of the opening spring 26 can be set relatively small.
Therefore, in this embodiment, it is possible to provide a barrier device that is small in size, high in reliability, and easy to assemble, and a lens barrel and a camera including this barrier device can obtain the same effect.

(Deformation)
The present invention is not limited to the embodiment described above, and various modifications and changes are possible, and these are also within the scope of the present invention.
(1) In this embodiment, the example which provided the spring hook part 21c in the barrier drive ring 21 was shown. However, even if a spring hooking portion for engaging a plurality of closing springs in common is provided in other parts such as a first group cylinder, for example, the space can be used effectively as in the above embodiment.

(2) In the present embodiment, the digital camera has been described as an example. However, the present invention is not limited to this. It may be a kind of imaging device.

(3) In this embodiment, the example which used the tension coil spring for the opening spring and each closing spring was shown. However, the present invention is not limited thereto, and for example, a compression coil spring may be used, or a biasing member of another form such as a torsion coil spring may be used.

  Note that the embodiment and the modified embodiment can be used in appropriate combination, but detailed description thereof is omitted. Further, the present invention is not limited by the embodiments described above.

It is a figure which shows embodiment of the camera containing the lens-barrel with the barrier apparatus by this invention. 2 is an exploded perspective view showing an outline of a configuration of a lens barrel 10. FIG. It is a figure which shows the structure of the 1st group cylinder 11 and the barrier apparatus with which it was equipped. FIG. 3 is a diagram showing the shape of the barrier drive ring 21 in detail. 3 is a cross-sectional view showing in detail the shape of a spring hook portion 21c of the barrier drive ring 21. FIG. It is detail drawing of a barrier blade rotating shaft vicinity. It is a figure which shows the state in which the barrier apparatus is closed. It is the perspective view which expanded and showed the barrier main blade | wing 22 and the barrier sub blade | wing 23 in the state with the barrier apparatus closed. It is BB sectional drawing shown by the arrow in FIG. It is a figure which shows the state which the barrier apparatus is open . It is a figure which shows an example of the rotational torque of an opening spring and a closing spring accompanying rotation of the barrier drive ring of a comparative example. It is a figure which shows the change of the rotational torque of an opening spring and a closing spring accompanying rotation of the barrier drive ring of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera body 10 Lens barrel 11 1st group cylinder 12 2nd group lens holder 13 Cam cylinder 14 Straight advance guide cylinder 15 Drive cylinder 16 Fixed cylinder 21 Barrier drive ring 22 Barrier main blade 23 Barrier sub blade 24 Barrier cover 25 First group lens 26 Opening Spring 27 Main blade closing spring 28 Sub blade closing spring

Claims (8)

A first blade member that can be opened and closed to cover the surface of the lens;
A second blade member that moves with the first blade member;
A common engagement portion provided on a member different from the first blade member and the second blade member;
A first biasing member that applies a biasing force to the first blade member by engaging one end with the common engagement portion and the other end with the first engagement portion of the first blade member. When,
One end is engaged with the common engaging portion with which the first urging member is engaged, and the other end is engaged with the second engaging portion of the second blade member , thereby the second blade member. a barrier device comprising a second biasing member, the providing a biasing force to,
The first urging member and the second urging member include a direction of a urging force received by the common engagement portion by the first urging member and the common engagement by the second urging member. The direction of the urging force received by the part is arranged so as to cancel each other, and the common engagement part, when viewed from the optical axis direction of the lens, is the first engagement part and the second engagement. It is arranged at a position sandwiched between
The common engagement portion changes the positional relationship between the first engagement portion and the second engagement portion when the first blade member and the second blade member are opened and closed. When the engaging portion and the first engaging portion are separated from each other, the common engaging portion and the second engaging portion are close to each other. When the common engaging portion and the first engaging portion are close to each other, the common engaging portion is close to the common engaging portion. A barrier device , wherein an engagement portion and the second engagement portion are separated from each other. The barrier device according to claim 1 ,
At least a part of the portion of the first blade member and the second blade member that covers the surface of the lens and the first biasing member and the second biasing member are optical axes of the lens. The barrier device is arranged so that positions in a direction along the line overlap. The barrier device according to claim 1 or 2 ,
The barrier device according to claim 1, wherein the first urging member and the second urging member are disposed closer to the subject side than the first blade member and the second blade member. In the barrier device according to any one of claims 1 to 3 ,
The barrier device according to claim 1, wherein the second urging member performs an opening / closing operation following the first urging member. In the barrier device according to any one of claims 1 to 4 ,
Two pairs of the first blade member and the second blade member are provided. In the barrier device according to any one of claims 1 to 5 ,
The barrier device according to claim 1, wherein the first urging member and the second urging member are formed of a coil spring. A lens barrel comprising: an imaging optical system; and the barrier device according to any one of claims 1 to 6 disposed on a subject side of a lens of the imaging optical system. An imaging apparatus comprising: the lens barrel according to claim 7; and an imaging unit that captures an image obtained by the lens barrel.

Images