JP4614195B2 - Camera lens barrier device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens barrier device for protecting a photographic lens in preparation for a camera such as a photographic camera using a film, an electronic still camera, a digital camera, or a video camera.
[0002]
[Prior art]
In order to protect the photographic lens, many cameras are equipped with a lens barrier device that opens the front side of the photographic lens when photographing and closes the front side of the photographic lens when photographing is stopped.
[0003]
This type of lens barrier device has a barrier configuration including a single barrier blade or a plurality of barrier blades.
Further, there are a camera body having a barrier blade directly on the camera body, or a lens barrier device having a barrier blade on the front side of the lens barrel.
[0004]
6 and 7 show a conventional example of a lens barrier device having four barrier blades.
The lens barrier device includes upper barrier blades 11a and 11b that are opened upward and lower barrier blades 12a and 12b that are opened downward.
[0005]
Then, the upper barrier blade 11a is driven by an interlocking lever 14 that turns right in conjunction with the pushing operation of the operation portion 13, and as shown in FIG. Move to.
[0006]
The barrier blade 11b is rotatably attached to the tip end portion of the barrier blade 11a by a support shaft 16, and moves upward as shown in FIG. Since the sliding pin 17 of the barrier blade 11 b advances through the guide hole 18, the moving posture is determined by the support shaft 16 and the sliding pin 17.
[0007]
The same applies to the lower barrier blades 12a and 12b. When the operation unit 13 is pushed, the barrier blade 12a driven by the interlocking lever 19 pivots about the support shaft 20 and moves to the open position. The barrier blade 12b connected to the tip end portion of the barrier blade 12a by the support shaft 21 moves to the open position in a moving posture determined by the slide pin 23 and the support shaft 21 that advance through the guide hole 22.
[0008]
The operation unit 13 is position-regulated at the pushing position where the barrier blade is opened by the click mechanism, and maintains the opened state of the barrier blade.
[0009]
Further, when the operating portion 13 is pulled and retracted, the upper barrier blades 11a and 11b and the lower barrier blades 12a and 12b move back by the spring force of the spring 24 suspended from the support shafts 16 and 21. Then, it moves to the closed position as shown in FIG.
[0010]
[Problems to be solved by the invention]
Since the barrier blades require a blade area that covers the entire front side of the photographic lens, the blade area of the barrier blades must be increased as the number of barrier blades is reduced.
[0011]
For example, a barrier blade having a large blade area is required when configured with one barrier blade, and a barrier blade with a small blade area can be used when configured with four barrier blades.
[0012]
On the other hand, a barrier blade with a large blade area needs to be moved and displaced greatly in order to open the front surface of the photographic lens, and the retraction movement distance of the opening operation (the distance from the position where the front surface of the photographic lens is fully closed to the position where it is fully opened) is Although it becomes longer, a barrier blade having a narrow blade area can shorten the retreat movement distance.
[0013]
As a result, the lens barrier device having one or two barrier blades having a large blade area is advantageous in that the structure is simple, but the retracting movement distance of the barrier blade is long, so that a large built-in space is provided. Is required.
For example, if a lens barrier device is provided on the front surface of the lens barrel, the lens barrel diameter must be increased.
[0014]
Further, a lens barrier device having a plurality of barrier blades having a small blade area, for example, the lens barrier device of FIGS. 6 and 7 shown as a conventional example, has a short retraction movement distance of the barrier blades 11a, 11b, 12a, and 12b. However, there is a problem that the configuration becomes complicated, although it is advantageous in terms of embedded space.
[0015]
In particular, in the case of the lens barrier device shown in FIGS. 6 and 7, the barrier blade 11b is connected to the tip of the barrier blade 11a, and the barrier blade 12b is connected to the tip of the barrier blade 12a. Since the springs 24 are suspended from the support shafts 16 and 21, the load applied to open the barrier blades becomes large, and a lens barrier device that operates lightly cannot be expected.
[0016]
Further, in this lens barrier device, the barrier blades 11a and 11b are overlapped by the opening operation, the barrier blades 12a and 12b are overlapped, the interlocking lever 14 is the barrier blade 11a, and the interlocking lever 19 is the barrier blade. Since the configuration overlaps each of 12a, there is a disadvantage that the device width in the optical axis direction increases.
[0017]
Further, when the barrier blades are closed, a step is generated between the barrier blades 11a and 12a and the barrier blades 11b and 12b, so that there is a problem that dust or the like adheres to the step portions, and also in terms of appearance. It is not preferable.
[0018]
In view of the above circumstances, the present invention is provided with four barrier blades, and these barrier blades are opened and closed on one side, and each barrier blade is independently driven by a cam of a barrier driving member to operate lightly and reliably. An object of the present invention is to provide a lens barrier device that can be used.
[0019]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, as a first invention, in a lens barrier device of a camera having a barrier blade that is opened by a shooting preparation operation of the camera and closed by a shooting stop operation, the lens barrier device is formed in a ring shape. One of the two barrier blades is pivotally supported at one of the symmetrical positions of the barrier base, the other two barrier blades are pivotally supported at the other position, and one of the two barrier blades is supported in the relative direction. The barrier blade mechanism configured to open and close the two barrier blades in a relative direction to open and close each of the four barrier blades on one surface, and the two barrier blades and the other two barrier blades are closed. a spring member providing a force, to communicate motion to the imaging preparation operation, to drive open in the relative direction of the cam and the other of the two barrier blades to open driving one of the two barrier blades above relative direction And a cam, four barrier blades described above proposes a lens barrier device for a camera, characterized by being configured more ring-shaped barrier driving member for opening against the spring force of the spring member.
[0020]
In the lens barrier device configured as described above, each barrier blade pivots on one surface to open and close, and each of the four barrier blades is independently driven by the cam of the barrier drive member to open, and the spring member Therefore, each of the barrier blades can be opened and closed with a uniform driving force, and the barrier blade can be operated lightly and reliably.
[0021]
As a second invention, in the lens barrier device according to the first invention described above, the bayonet claw formed around the ring-shaped barrier driving member can be rotated to the front of the camera body or the lens barrel. In addition, a camera lens barrier device is proposed in which a barrier base is used as a barrier cover, and its peripheral portion is attached to the front of the camera body or lens barrel by bayonet means.
[0022]
The lens barrier device configured as described above does not need to be provided with a mounting portion on the surfaces of the barrier driving member and the barrier base, and the entire surface can be used as a moving region of the barrier blades.
As a result, the movement region of the barrier blade is widened, which is particularly advantageous as a barrier blade mechanism that opens and closes on one side.
[0023]
A third invention proposes a lens barrier device for a camera according to the first or second invention, wherein each barrier blade is formed of a thin metal plate.
[0024]
Since this lens barrier device has a configuration in which four barrier blades made of a thin metal plate open and close on one surface, the device width in the optical axis direction is shortened, which is extremely advantageous for incorporation.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view showing a lens barrier device, in which 31 is a frame plate fixed to the camera body, 32 is a lens barrel, 33 is a decorative ring, 34 is a barrier drive ring that provides torque by a coil spring 35, and 36 is The blade presser plates 37 and 38 are one of the first and second barrier blades, 39 and 40 are the other first and second barrier blades, 41 and 42 are springs for applying a closing force to the barrier blades, and 43 is a barrier base. Barrier cover 44, 44 is a rotation stop of barrier cover 43, 45 is a decorative nameplate.
[0026]
The inclined cam 31b formed on the cam plate 31a of the frame plate 31 is in contact with the interlock cam 34a of the barrier drive ring 34, and the interlock cam 34a slides on the inclined cam 31b to rotate the barrier drive ring 34. .
[0027]
The lens barrel 32 is housed in the camera body by the photographing stop operation, and is extended from the stowed position by the photographing preparation operation to advance to the photographing possible position.
[0028]
The lens barrel 32 includes a photographic lens 32a, a bayonet locking portion 32b for locking the bayonet claw 34b of the barrier drive ring 34, and a bayonet for locking the bayonet claw 43a of the barrier cover 43. And a locking portion 32c.
[0029]
That is, the barrier drive ring 34 is rotatably attached to the lens barrel 32 by the bayonet means, and the barrier cover 43 is fixedly attached to the lens barrel 32 by the bayonet means.
[0030]
In addition, a hole formed in the optical axis direction is provided in the periphery of the lens barrel 32, and the cam plate 31a of the frame plate 31 is projected through the hole into a notch formed in the periphery on the front side of the lens barrel 32. It is like that.
[0031]
The barrier drive ring 34 receives a right turning force by a coil spring 35 suspended between the ring 34 and the lens barrel 32.
That is, when the lens barrel 32 is retracted to the storage position, the barrier drive ring 34 also moves backward, and the interlocking cam 34a slides left from the inclined cam 31b. Spring force is stored.
[0032]
When the lens barrel 32 is extended from the storage position, the barrier drive ring 34 also moves forward, and the interlocking cam 34a rises while sliding on the inclined cam 31b, so that the barrier drive ring 34 is a spring of the coil spring 35. Turns right under force.
[0033]
Further, the barrier driving ring 34 drives four barrier blades, and cams 46 and 47 for driving the barrier are provided at symmetrical positions.
[0034]
One of the first barrier blade 37 and the second barrier blade 38 is pivotally supported at one end thereof on the barrier cover 43 by the same support shaft 48, and is also provided by a single spring 41 provided on the support shaft 48. The first and second barrier blades 37 and 38 are configured to give a closing force. (See Figure 2)
[0035]
Similarly, the other first barrier blade 39 and the second barrier blade 40 are pivotally supported on the barrier cover 43 by the same support shaft 49 and are closed by one spring 42 provided on the support shaft 49. It has come to give power. (See Figure 2)
[0036]
Further, the drive pins 50 and 51 (see FIG. 2) provided on one of the first and second barrier blades 37 and 38 are brought into contact with the cam 46 of the barrier drive ring 34 through the notch 36a of the blade pressing plate 36. The drive pins 52 and 53 (see FIG. 2) provided on the other first and second barrier blades 39 and 40 pass through the notches 36b of the blade pressing plate 36 and are connected to the cam 47 of the barrier drive ring 34. It comes to meet.
[0037]
The blade pressing plate 36 is provided between the barrier drive ring 34 and the barrier blade, and smoothes the operation of the barrier blade by a linear ridge portion 36 c formed on the pressing plate 36.
[0038]
In the lens barrier device having the above configuration, the barrier drive ring 34 is assembled to the lens barrel 32 by the bayonet means, and the barrier cover 43 to which the barrier blade and the blade presser 36 are attached is assembled to the lens barrel 32 by the bayonet means.
At this time, the decorative ring 33 is fitted to the outside of the lens barrel 32.
After the rotation stopper 44 of the barrier cover 43 is assembled, the decorative name plate 45 is attached to the front surface of the barrier cover 43.
[0039]
Next, the operation of the lens barrier device described above will be described with reference to FIGS.
FIG. 2 is a configuration diagram of the main part showing the closed state of the barrier blades. In this figure, the barrier driving ring 34, the barrier blades 37 to 40, and the barrier blade driving unit are shown, and the lens barrel 32, the blade pressing plate 36, the barrier cover. -43 etc. are omitted.
The two-dot chain line 43b shown in the figure indicates a light passage hole provided in the barrier cover 43.
[0040]
As already described, when the lens barrel 32 is housed in the camera body, the interlock cam 34a of the barrier drive ring 34 slides down the inclined cam 31b of the cam plate 31a, so that the barrier drive ring 34 is a spring of the coil spring 35. Turn left to store power.
[0041]
When the barrier drive ring 34 rotates to the left and the cams 46 and 47 rotate, the drive pins 50 and 51 of the first and second barrier blades 37 and 38 and the first and second barrier blades 39 of the other side. , 40 are allowed to pivot with respect to the drive pins 52, 53, and the first and second barrier blades 37, 38 rotate by receiving the spring force of the spring 41, and the other first, second 2 The barrier blades 39 and 40 are swung by receiving the spring force of the spring 42, and the barrier is closed as shown in FIG.
[0042]
FIG. 3 is a partially enlarged view of FIG. 2 showing a driving portion of one of the first and second barrier blades 37 and 38.
As shown in the figure, the cam 46 provided on the barrier drive ring 34 has a straight cam portion 46a and a curved cam portion 46b. The straight cam portion 46a drives the drive pin 50, and the curved cam portion 46b drives the drive pin 51. It is configured to drive.
[0043]
As for the cam 46, a stepped wall of the concave surface portion and the ring surface formed on the barrier drive ring 34 is formed as a straight cam portion 46a and a curved cam portion 46b, and the drive pins 50 and 51 are inserted into the concave surface portion. I'm allowed.
[0044]
Accordingly, when the barrier drive ring 34 rotates to the left, the straight cam portion 46a moves away from the drive pin 50, and the drive pin 51 slides down the curved cam portion 46b. The blades 37 and 38 are rotated by the spring force of the spring 41, and as shown in FIG. 2, a barrier closing operation is performed.
[0045]
The other cam 47 has the same configuration as the cam 46 described above, and the drive pin 52 is driven by the straight cam portion 47a and the drive pin 53 is driven by the curved cam portion 47b.
Accordingly, when the barrier drive ring 34 rotates to the left, the straight cam portion 47a moves away from the drive pin 52, and the drive pin 53 slides down the curved cam portion 47b, so that the other first and second barriers are moved. The blades 39 and 40 are swung by the spring force of the spring 42, and are closed as shown in FIG.
[0046]
On the other hand, when the lens barrel 32 is extended from the storage position, the interlock cam 34a of the barrier drive ring 34 rises while sliding on the inclined cam 31b of the cam plate 31a as described above, and the spring force of the coil spring 35 is increased. Upon receipt, turn right.
[0047]
As a result, the cams 46 and 47 of the barrier drive ring 34 drive the drive pins 50, 51 and 52 and 53 to open the barrier blades as shown in FIG.
Specifically, when the barrier drive ring 34 rotates to the right, the straight cam portion 46a of the cam 46 pushes around the drive pin 50 and the drive pin 51 moves to the curved cam portion as shown in an enlarged view in FIG. Turn while climbing 46b.
[0048]
Accordingly, one of the first and second barrier blades 37 and 38 turns against the spring force of the spring 41 and moves to the barrier opening position.
FIG. 5 is a partially enlarged view of FIG.
The cam 47 on the other side operates in the same manner, and the drive pin 52 is pushed around by the straight cam portion 47a, and the drive pin 53 turns so as to rise up the curved cam portion 47b. , 40 turns and moves to the barrier opening position.
[0049]
Thus, by extending the lens barrel 32, the barrier drive ring 34 rotates to the right, so that the first and second barrier blades 37 and 38 on one side and the first and second barrier blades 39 and 40 on the other side. The light passage hole 43b is opened as a whole, and photography is possible.
[0050]
When the lens barrel 32 is housed in the camera body with the barrier blades opened in this manner, the barrier drive ring 34 rotates to the left in FIG. 4, and as described above, the straight cam portions 46a, 47a of the cams 46, 47. Moves away from the drive pins 50 and 51, and the curved cam portions 46 b and 47 b move so as to slide down the drive pins 52 and 53, so that one of the first and second barrier blades 37 and 38 of the spring 41 2 is closed by the spring force, and the other first and second barrier blades 39, 40 are closed by the spring force of the spring 42 to be in the barrier closed state shown in FIG.
[0051]
In the state of FIG. 2 in which the barrier blades are closed, one first barrier blade 37 and one side edge of the other first barrier blade 39 are in contact with each other, and one second barrier blade 38 is in contact with the other first barrier blade. The other side edge of the blade 39 is in contact with the other side edge, and the other second barrier blade 40 is in contact with the other side edge of the first barrier blade 37.
As a result, a lens barrier device in which one first and second barrier blades 37 and 38 and the other first and second barrier blades 39 and 40 are closed on one surface is obtained.
[0052]
In the above, an example implemented for a camera in which the lens barrel 32 is extended has been described. However, for a camera in which the lens barrel is not extended, the barrier drive ring 34 is rotated in conjunction with the shooting preparation operation and the shooting stop operation. It can implement similarly to the above by setting it as a structure.
[0053]
【The invention's effect】
As described above, according to the present invention, the four barrier blades are provided to shorten the retracting distance of the barrier blades, and each barrier blade is driven independently by the cam of the barrier drive ring. The area of the barrier blade can be reduced by shortening the retraction movement distance of the barrier blade, and the lens barrier device can be opened and closed easily and reliably.
[0054]
In addition, since this lens barrier device opens and closes on one surface, the step of the barrier blade does not occur in the closed state, so that dust or the like does not adhere to the step portion of the barrier blade, In addition, the lens barrier device has a good appearance.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a lens barrier device shown as an embodiment of the present invention.
FIG. 2 is a main part configuration diagram showing a barrier closed state of the lens barrier device.
3 is an enlarged partial view of a part of FIG.
FIG. 4 is a main part configuration diagram similar to FIG. 2 showing a barrier open state;
FIG. 5 is an enlarged partial view of a part of FIG. 3;
FIG. 6 is a simplified diagram showing a barrier closed state of a lens barrier device shown as a conventional example.
7 is a simplified diagram similar to FIG. 6 showing a barrier open state.
[Explanation of symbols]
31 Frame plate 31a Cam plate 32 Lens barrel 34 Barrier drive ring 34a Interlocking cam 35 Coil springs 37 and 38 One first and second barrier blades 39 and 40 The other first and second barrier blades 41 and 42 Spring 43 Barrier cover −
46, 47 Cam 46a, 47a Linear cam part 46b, 47b Curved cam part 50, 51, 52, 53 Drive pin

Claims (3)

In a camera lens barrier device having a barrier blade that is opened by a shooting preparation operation of the camera and closed by a shooting stop operation,
The two barrier blades are pivotally supported at one of the symmetrical positions of the ring-shaped barrier base, the other two barrier blades are pivotally supported at the other position, and the two barrier blades are relative to each other. A barrier blade mechanism configured to open and close the other two barrier blades in a relative direction to open and close each of the four barrier blades on one surface ,
A spring member for applying a closing force to each of the one two barrier blades and the other two barrier blades;
And communicating motion to shooting operation, and a cam for opening driving cam and the other of the two barrier blades to open driving one of the two barrier blades above relative direction relative direction, four barrier blades described above A lens barrier device for a camera, comprising: a ring-shaped barrier driving member that opens against a spring force of the spring member. 2. A lens barrier device for a camera according to claim 1, wherein a bayonet claw formed around the barrier drive member formed in a ring shape is rotatably connected to the front of the camera body or the lens barrel, and further a barrier base. A lens barrier device for a camera, characterized in that a peripheral cover is attached to the front of the camera body or lens barrel by bayonet means. The camera lens barrier device according to claim 1 or 2,
A camera lens barrier device, wherein each barrier blade is formed of a thin metal plate.

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