JP5773670B2 - Barrier device and lens barrel - Google Patents

Description

  The present invention relates to a photographing lens barrier device provided to protect a photographing lens.

  For example, Patent Document 1 discloses a lens barrel having an openable / closable barrier device provided in front of the lens.

JP 2008-033152 A

  However, in order to rotationally drive the barrier blade, the line connecting the rotating shaft of the barrier blade and the hook portion that hooks the barrier drive spring needs to be directed in the radial direction, so that the radial direction of the lens barrel increases. .

In order to achieve the above object, a barrier device according to the present invention relates to a barrier driving member that rotates around an optical axis as the lens barrel shifts from a photographing state to a standby state, and one end of the barrier device is engaged with the barrier driving member. A barrier device having a combined elastic member and a barrier blade that engages with the other end of the elastic member and opens and closes by the biasing force of the elastic member by rotation of the barrier driving member ;
When viewed from the optical axis direction, with the rotation of the barrier driving member, the protrusion provided on the barrier driving member causes the lens barrel to move in an outer diameter direction different from the biasing direction of the elastic member itself. The elastic member is bent .

  ADVANTAGE OF THE INVENTION According to this invention, the barrier apparatus which enabled it to perform the stable barrier opening / closing operation | movement, without enlarging radial direction can be provided.

It is a disassembled perspective view of a barrier mechanism. It is a front view which shows a barrier fully closed state. It is a front view which shows the state of the barrier opening start. It is a front view which shows a barrier full open state. It is a figure which shows the charge amount change of a barrier drive spring. It is a figure which shows a prior art example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Disassembled perspective view of lens barrel>
FIG. 1 is an exploded perspective view of the lens barrel 20.
The lens barrel 20 has a shooting state and a standby state, and the first lens unit 3 also shifts between the shooting state and the standby state as the lens barrel shifts between the shooting state and the standby state. The first lens unit 3 holds the photographing lens 4 and moves along the optical axis direction 1. Inside the first lens unit 3, a rectilinear cylinder 2 that restricts the rotation of the lens barrel 3 is disposed. The first lens unit 3 moves in the optical axis direction by the restriction of rotation by the straight cylinder 2 and a cam groove provided in a cam cylinder (not shown) outside the first lens unit 3.

  The first lens unit 3 and the rectilinear tube 2 are relatively separated in the optical axis direction (the overlapping amount in the optical axis direction is reduced) as the lens barrel shifts from the standby state to the photographing state. On the other hand, with the transition of the lens barrel from the photographing state to the standby state, the first lens unit 3 and the straight traveling tube 2 relatively approach the optical axis direction (the overlapping amount in the optical axis direction increases).

  At the front end of the first lens unit 3 on the subject side, there are barrier blades 7 and 8 that are pivotally supported so as to be able to shift between an open state and a closed state. Further, there is a barrier driving member 5 that drives the barrier blades 7 and 8. In addition, a barrier cover 10 having a photographing opening 10a is provided, and when the lens barrel 3 is in a standby state, the barrier blades 7 and 8 are closed so that the photographing lens 4 is located with respect to the photographing opening 10a. Is covered. The barrier cover 10 is fixed to the first lens unit 3 by a barrier cover fixing member 9.

  The barrier drive member 5 is supported so as to be rotatable relative to the first lens unit 3 around the optical axis. A barrier drive spring 6 as an elastic member is engaged with each of the barrier blades 7 and 8 and the barrier drive member 5. The barrier drive spring 6 is a tension coil spring, but the elastic member may be a rubber instead of a coil spring.

  The barrier drive spring 6 is urged in the direction in which the barrier blades 7 and 8 abut against the barrier drive member 5, and the rotation of the barrier drive member 5 and the opening and closing of the barrier blades 7 and 8 are interlocked by this urging force.

  Here, when the first lens unit 3 shifts from the standby state to the photographing state, the phase of rotation of the barrier driving member 5 in which the barrier blades 7 and 8 are opened is referred to as “barrier opening phase”. The phase of the barrier driving member 5 when the barrier blades 7 and 8 are in the closed state when the first lens unit 3 shifts from the photographing state to the standby state is referred to as a “barrier closed phase”.

  The barrier drive member 5 is provided with a protrusion 5a protruding toward the image pickup side, and a cam surface 2a is formed on the rectilinear cylinder 2 so as to correspond to the protrusion 5a. When the first lens unit 3 shifts from the shooting state to the standby state, the first lens unit 3 moves to the imaging side, so that the protrusion 5a and the cam surface 2a come into contact with each other. After this contact, the protrusion 5a and the cam surface 2a are engaged by the inclination of the cam surface 2a, so that the driving force in the optical axis direction becomes the driving force in the rotation direction around the optical axis of the barrier driving member 5. Converted. As a result, the barrier drive member 5 rotates around the optical axis, so that the barrier drive member 5 rotates in the direction of arrow A while charging the barrier drive spring 6. The barrier driving member 5 is rotated to the “barrier closing phase” to close the barrier blades 7 and 8.

  On the other hand, when the first lens unit 3 shifts from the standby state to the photographing state, the first lens unit moves in the optical axis direction toward the subject. Accordingly, the first lens unit and the barrier driving member 5 that is rotatably fixed to the first lens unit are separated from the rectilinear cylinder 11. Due to the separation between the barrier driving member 5 and the rectilinear cylinder 11, the contact between the projecting portion 5a and the cam surface 2a which have been engaged so far is released. Then, the barrier driving member 5 rotates in the direction of the arrow B while releasing the charge of the barrier driving spring 6 and rotates to the “barrier opening phase” to open the barrier blades 7 and 8.

<Charge of barrier drive spring>
Next, the operation of the barrier blade 7 and the charge amount of the barrier drive spring will be described with reference to FIGS. 1 and 2 to 5. The barrier blade 8 is linked to the operation of the barrier blade 7, and therefore the description thereof is omitted for simplicity.

  FIG. 2 is a front view showing the closed state of the barrier blade 7 in the standby state of the lens barrel 20. In FIG. 2, the barrier blade 7 is urged in the direction of arrow C shown in FIG. 2 or the like by a tension that is an urging force of the barrier drive spring 6 as an elastic member. With this urging force, the barrier blades 7 are kept closed in the standby state of the lens barrel 20. Further, the barrier driving member 5 is biased in the rotation direction of the arrow B shown in FIG. 1 by a tension which is a biasing force of the barrier driving spring 6 as an elastic member. In the standby state of the lens barrel 20, the rotation in the arrow B direction is restricted by the action obtained by the protrusion 5a coming into contact with the cam surface 2a formed on the rectilinear barrel 2. At this time, the charge amount of the barrier drive spring 6 is in the fully closed state shown in FIG.

  FIG. 3 is a front view showing a state in which the lens barrel 20 starts to shift from the standby state to the photographing state and the barrier blade 7 starts to open. In this state, as compared with the standby state of the lens barrel 20, the barrier driving member 5 and the rectilinear barrel 2 are moved in a direction away from each other. Therefore, the barrier drive member 5 is slightly rotated in the direction of arrow B in FIG. 1 by the engagement between the cam surface 2a of the straight cylinder 2 and the protrusion 5a. On the other hand, since the contact portion 5 b of the barrier drive member 5 is in contact with the barrier blade 7, the charge amount of the barrier drive spring 6 decreases as the rotation angle of the barrier drive member 5 increases. This is because the cam surface 2a is inclined with respect to the optical axis direction.

  At this time, the charge amount of the barrier drive spring 6 is smaller than that in the fully closed state shown in FIG. Accordingly, when the barrier driving member 5 rotates around the optical axis as the lens barrel 20 shifts from the standby state to the photographing state, the charge amount of the elastic member 6 decreases as the rotation angle increases.

On the other hand, when the barrier driving member 5 rotates around the optical axis in the opposite direction as the lens barrel 20 shifts from the photographing state to the standby state, the amount of charge of the elastic member 6 increases as the rotation angle increases. Increase .

  FIG. 4 is a view when the lens barrel 20 further shifts from the standby state to the photographing state, and is a front view showing a state where the barrier blades 7 are fully opened. In this state, the protrusion 5a of the barrier drive member 5 and the cam surface 2a of the rectilinear cylinder 2 are disengaged, and the protrusion 5a and the cam surface 2a are separated. Therefore, the barrier driving member 5 further rotates in the direction of arrow B to enter the “barrier opening phase”, and the charge amount of the barrier driving spring 6 is in the fully opened state shown in FIG.

  The barrier blade 7 is pushed in the opening direction at the contact portion 5 a with the barrier driving member 5. However, when the tip of the barrier blade comes into contact with the stopper 3b provided in the first lens unit 3, the rotation in the opening direction is restricted.

  Here, in the conventional example shown in FIG. 6, the rotating shaft 14c of the barrier blade 14 and the hook portion 14b of the barrier driving spring provided on the barrier blade 14 are provided with a distance L4 in the radial direction. Therefore, a rotational force acts on the barrier blade 14 around the rotation shaft 14c. However, as the distance L4 is provided in the radial direction, the diameter of the lens barrel increases. On the other hand, if the distance L4 is shortened in order to reduce the diameter of the lens barrel, the barrier blade 14 cannot be given a rotational force efficiently.

  Therefore, in the present invention, the inflection portion 6 a is provided in the barrier drive spring 6. A moment can be generated by providing the inflection portion 6 in a direction different from the urging direction of the barrier drive spring 6 itself as an elastic member. Even if the rotating shaft 3a and the hook portion 7a with which the barrier drive spring 6 engages are short, the inflection portion 6a can increase the circumferential moment of the rotation when rotating around the rotating shaft 3a. . This is because by providing the inflection portion 6a, the barrier drive spring 6 can be tilted so as to approach the circumferential direction. Thereby, even if the diameter of the lens barrel is small, opening and closing of the barrier blade 7 can be achieved by applying a moment in the direction of arrow C in FIGS. I am doing so.

  Here, the closer the position of the protrusion 5c provided on the barrier driving member 5 is to the hook 7a, the easier it is to obtain torque for driving the barrier blades 7. This is because a moment in the circumferential direction of the rotating shaft 3a is likely to be generated. However, since the barrier driving member 5 is also rotating, it is necessary to prevent the positional relationship between the rotating shaft 3a and the hook portion 7a from being obstructed. That is, the position of the protrusion 5c provided on the barrier driving member 5 is determined by the balance between the two.

  Here, in the above description, in order to make the barrier drive spring 6 have the transformation portion 6a, the barrier drive member 5 is provided with the protrusion 5c, and the barrier drive spring 6 is brought into contact with the protrusion 5c. Yes. In this respect, the barrier drive spring 6 may have the transmutation portion 6a. For example, the barrier cover fixing member 9 may have a protrusion. However, when the barrier cover fixing member 9 is provided with a protrusion, unlike the case where the above-described protrusion 5c is provided, the barrier drive member 5 does not rotate around the optical axis. Must have a special shape.

  In the above description, the barrier drive member 5 is provided with the semicircular protrusion 5c as a method for providing the barrier drive spring 6 with the transmutation portion 6a. In this regard, if the barrier driving spring 6 is provided with the inflection point 6a, the barrier driving spring 6 may have a rectangular shape instead of a semicircular shape, and its method and shape are not limited. However, if the rectangular portion is provided, there is a high possibility that the coil spring as an elastic member will be caught or that rubber will be damaged when rubber is used as the elastic member.

  The barrier drive spring 6 is always in contact with the protrusion 5 c provided on the barrier drive member 5 when the barrier blade 7 is opened and closed. Therefore, the force of the barrier drive spring 6 can be efficiently directed in the direction of arrow C regardless of whether the barrier blade 7 is opened or closed. Therefore, the opening / closing operation of the barrier blade 7 can be stabilized. However, if it is allowed to reduce the efficiency, it is not always necessary to contact the protrusion 5c provided on the barrier driving member 5 when the barrier blade 7 is opened and closed.

  Further, even if the distance between the rotary shaft 3a and the hook portion 7a is not in the radial direction, the force can be efficiently applied in the direction of the arrow C, so that the lens barrel diameter can be shortened and the lens barrel can be downsized. It becomes.

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

DESCRIPTION OF SYMBOLS 1 Optical axis 2 Straight advance cylinder 2a Cam surface 3 Lens barrel 3a Rotating shaft 3b Stopper 4 Lens 5 Barrier drive member 5a Cam surface 5b Contact part 5c Projection part 6 Barrier drive spring 6a Inflection point 7 Barrier blade 7a Hook part 8 Barrier Blade 9 Barrier cover fixing member 10 Barrier cover 10a Shooting opening

Claims (4)

As the lens barrel shifts from the photographing state to the standby state, a barrier driving member that rotates around the optical axis , an elastic member having one end engaged with the barrier driving member, and the other end of the elastic member are engaged. Together
And, a barrier device and a barrier blades to open and close by the biasing force of the elastic member by the rotation of the barrier driving member,
When viewed from the optical axis direction, with the rotation of the barrier driving member, the protrusion provided on the barrier driving member causes the lens barrel to move in an outer diameter direction different from the biasing direction of the elastic member itself. A barrier device in which an elastic member is bent . When the barrier driving member rotates around the optical axis as the lens barrel shifts from the standby state to the photographing state, the charge amount of the elastic member decreases as the rotation angle increases, and the lens mirror with the shooting state of the cylinder to the transition to the standby state, the barrier device according to claim 1, characterized in that the charge amount of the elastic member is increased according to the increase of the rotation angle. 3. The barrier device according to claim 1 , wherein contact between the protrusion and the elastic member is maintained during a transition period between the open state and the closed state of the barrier blade . A lens barrel having the barrier device according to any one of claims 1 to 3.

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