JP3532996B2 - Lens barrier mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens barrier mechanism for protecting a lens of a camera or the like.

[0002]

2. Description of the Related Art Recently, in compact cameras and the like, a lens barrier mechanism, which is attached to the front end of a photographing lens barrel and opens and closes a photographing opening, is used instead of the lens cover of the camera. In general, a lens barrier mechanism has a plurality of barrier blades, and usually one pair of barrier blades is driven by a motor, and another pair of driven barrier blades is driven by this to form two pairs of barrier blades. It is configured to open and close. The conventional lens barrier mechanism has a barrier drive ring rotatable inside the lens barrel, and when the barrier blade is opened, a protrusion provided on the barrier drive ring biases a boss formed on the barrier blade. , Move the barrier blade to the open position, and when closing, release the bias of the barrier drive ring to the boss and move it to the closed position by the bias of the spring arranged to bias the barrier blade in the closing direction. It was a moving structure. In addition to this, a lens barrier mechanism using a spring has been proposed instead of the protrusion of the barrier drive ring.

[0003]

However, in the method of opening and closing the barrier blades by the protrusions of the barrier drive ring, the barrier blades are closed when the barrier blades are closed due to the dimensional variations of the protrusions and bosses of the barrier drive ring. There is a drawback that a so-called open / close residue easily occurs with a gap between them. Also, in the method of using a spring instead of the protrusion,
Since both the spring for urging the barrier blade in the opening direction and the spring for urging the barrier blade in the closing direction must be mounted, the assembly work becomes complicated and the spring may be deformed during assembly.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens barrier mechanism which prevents the opening and closing of barrier blades and which is easy to assemble.

[0005]

In order to achieve the above object, the present invention provides a support shaft for rotatably holding a drive blade,
A boss formed at an end of the drive blade, and a first elastic member for urging the boss in a direction in which the drive blade rotates in the first direction,
The second elastic member includes a second elastic member that biases the boss in a direction in which the drive blade rotates in the second direction, and a separating unit that separates the first elastic member from the boss. The second elastic member is the first elastic member. Weaker than the above, the first elastic member and the second elastic member both urge the bosses to rotate the drive blades in the first direction, and the separating means separates the first elastic members from the bosses. The drive blade is rotated in the second direction by urging the boss only by the elastic member. Note that the first direction is the direction in which the drive blades are opened and the second direction is the direction in which the drive blades are closed, or the first direction is the direction in which the drive blades are closed and the second direction is the direction. A configuration in which the drive blades are opened is possible. Further, it is also possible that the first elastic member and the second elastic member are shaped portions formed on a mounting plate to which the drive blade is attached. Further, the plurality of blades includes at least one drive blade and at least one driven blade, and the driven blade may be configured to move between the open position and the closed position by engaging the drive blade. Is. Alternatively, the separating means may be a cam-shaped portion formed on a drive ring that slides in the camera barrel. Further, the support shaft may be a shaft portion formed on the decorative plate.

[0006]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is an exploded perspective view showing a main part of a barrier mechanism according to the present invention. At the top of the shooting lens, there is a decorative plate 10.
Is provided. The decorative plate 10 is a lens barrel 10.
It is fixed at 0 and has a photographing opening 11. The first barrier blades 40, 50 and the second barrier blades 62, 64 are provided on the camera body side of the decorative plate 10, and the barrier mounting plate 20 is provided on the camera body side. The barrier mounting plate 20 is fixed to the decorative plate 10.

Of the first barrier blades 40, 50 and the second barrier blades 62, 64, the first barrier blade 40 and the second barrier blade 62 are rotatably supported by the support shaft 12 provided on the decorative plate 10. , The first blade 50 and the second barrier blade 64
Is provided on the decorative plate 10 and is rotatably supported by a support shaft 14. The tips of the support shafts 12 and 14 are fitted into the barrier mounting plate 20, so that the first barrier blades 40 and 50 and the second barrier blades 62 and 64 are located between the decorative plate 10 and the barrier mounting plate 20. Is rotatably supported by.

When opening the opening 11, the first barrier blade 40, the second barrier blade 62, and the first barrier blade 5
0 and the second barrier blade 64 are set to overlap each other in the optical axis direction. Further, when closing the opening 11, the first barrier blades 40 and 50 close the central portion of the opening 11, and the second barrier blades 62 and 64 cause the first barrier blade 4 to move.
It is set to close the peripheral part of the part where 0 and 50 are closed.

The second barrier blade 62 is provided with an engaging portion 65 and a protruding portion 66. When the first barrier blade 40 rotates in the closing direction, the contact portion 45 provided at the tip of the first barrier blade 40 contacts the protruding portion 66 of the second barrier blade 62 to close the second barrier blade 62 in the closing direction. Turn to. When the first barrier blade 40 rotates in the opening direction, the contact side 46 of the first barrier blade 40 contacts the engaging portion 65 of the second barrier blade 62, and the second barrier blade 62 rotates in the opening direction. . In this way, the second barrier blade 62 is made into the first barrier blade 4
Follow 0. Similarly, the second barrier blade 64 follows the first barrier blade 50.

Since the second barrier blades 62, 64 are driven by the first barrier blades 40, 50, the opening / closing operation of the first barrier blades 40, 50 will be described below.
For simplicity, the first barrier blades 40 and 50 are simply the barrier blades 40 and 50.

First, the barrier mounting plate 20 will be described. The barrier mounting plate 20 is made of an elastic body, and as shown in FIG. 1, first elastic members 210 and 220 are integrally formed on the surface of the barrier mounting plate 20 on the side of the barrier drive ring 30. One end of each of the first elastic members 210 and 220 is connected to the vicinity of the outer periphery of the barrier mounting plate 20, and the other end is formed so as to project further inward than the inner periphery of the barrier mounting plate 20. Bent portions 212 and 222 are formed in substantially central portions of the first elastic members 210 and 220. Further, the barrier mounting plate 20 includes second elastic members 230, 2
40 is integrally formed. This second elastic member 23
One end of each of 0 and 240 is connected to the vicinity of the outer periphery of the barrier mounting plate 20, and the other end is formed to be located near the outer periphery of the barrier mounting plate 20.

Bosses 41 and 51 are projected from the tips of the barrier blades 40 and 50, respectively. This boss 41, 51
Penetrates through the holes 22 and 24 formed in the barrier mounting plate 20 and projects toward the barrier drive ring 30 side of the barrier mounting plate 20. 2 and 3 are front views seen from the position A in FIG. 1, and FIG. 2 is a view when the barrier blades 40 and 50 are open,
FIG. 3 shows the state when the barrier blades 40, 50 are closed. Here, as shown in FIG. 2, the first elastic member 210 is located on the outer peripheral side and the second elastic member 230 is located on the inner peripheral side with the boss 41 interposed therebetween. Similarly, the first elastic member 220 is located on the outer peripheral side and the second elastic member 240 is located on the inner peripheral side with the boss 51 interposed therebetween. Here, since the first elastic members 210 and 220 are deformed toward the outer circumference of the barrier drive ring 30, the elastic force toward the inner circumference of the barrier drive ring 30 is charged. Similarly, the second elastic members 230 and 240 are deformed toward the inner circumference of the barrier drive ring 30, so that the elastic force toward the outer circumference of the barrier drive ring 30 is charged. Therefore, the boss 41 has the first elastic member 210 and the second elastic member 23.
0 is urged from both sides, and the boss 51 moves the first elastic member 220.
And the second elastic member 240 is urged from both sides. Here, since the deformation amount of the second elastic members 230, 240 is smaller than the deformation amount of the first elastic members 210, 220, the elastic force charged in the second elastic members 230, 240 is the first elastic member 210, Less than 220. Therefore boss 4
Nos. 1 and 51 are located on the inner peripheral side of the barrier mounting plate 20 because the biasing force from the outer peripheral side toward the inner peripheral side is greater.

Next, the barrier drive ring 30 will be described. As shown in FIG. 1, the barrier drive ring 30 is slidably supported between the barrier mounting plate 20 and the lens barrel 100. As shown in FIG. 2, on the barrier drive ring 30,
Along the inner circumference of the barrier drive ring 30, the cam portions 310, 32
0 is formed. As shown in FIG. 2, the cam portion 31
0 and 320 are slopes 312 and 322, respectively, and the upper surface 31.
4, 324. A gear portion 34 is formed on a part of the cam portion 320, and the gear portion 34 meshes with the pinion 102 provided on the lens barrel 100. The pinion 102 is driven by a motor (not shown), and the rotation of the pinion 102 rotates the barrier drive ring 30.

When the barrier drive ring 30 rotates counterclockwise in the drawing, the slopes 312 and 322 of the cam members 310 and 320 are rotated.
Is the bent portions 212, 222 of the first elastic members 210, 220.
Abut. Accordingly, the first elastic members 210, 22
Since the biasing force by which 0 biases the bosses 41, 51 is limited, the bosses 41, 51 move toward the outside of the barrier mounting plate 20 by the biasing of the second elastic members 230, 240. When the barrier drive ring 30 further rotates and the upper surfaces 314 and 324 of the cam members 310 and 320 contact the bent portions 212 and 222, as shown in FIG.
Since 0 and 220 go out of the range of movement of the bosses 41 and 51, the bosses 41 and 51 are attached to the second elastic members 230 and 240.
It is urged by only and moves to the outside of the barrier mounting plate 20.

Next, the operation of the barrier blades 40 and 50 will be described. 4 is shown in FIG. 2 and FIG. 5 is shown in FIG.
The positions 0 and 50 are added. As shown in FIG. 4, the cam members 310 and 320 are elastic members 210 and 220.
Since the bosses 41 and 51 are located on the inner peripheral side of the barrier mounting plate 20 when not in contact with the barrier blades 40 and 50,
Is completely open. Even if the barrier blades 40, 50 are completely opened, the first elastic members 210, 22
0 urges the bosses 41 and 51 in a direction to further open the barrier blades 40 and 50. Next, the cam drive ring 30 rotates and the cam members 310 and 320 move the first elastic member 21.
When contacting 0, 220, the first elastic members 210, 220
Moves to the outer periphery of the barrier drive ring 30, and the second elastic member 23
The bosses 41 and 51 can be attached to the barrier mounting plate 2 depending on 0 and 240.
Move toward the outer circumference of 0. With the movement of the bosses 41 and 51, the barrier blades 40 and 50 rotate clockwise about the rotation shafts 42 and 52. Then, as shown in FIG. 5, the barrier blades 40 and 50 stop at the position where they abut each other.
Even if the barrier blades 40 and 50 are completely closed, the second
The elastic members 230 and 240 further urge the bosses 41 and 51 in the direction of closing the barrier blades 40 and 50.

As described above, when the barrier blades 40 and 50 are completely opened, the bosses 41 and 51 are in the first position.
The elastic blades 210 and 220 allow the barrier blade 4
The barrier blades 40, 40 are urged in the opening direction.
When 50 is completely closed, bosses 41, 51
Are further urged by the second elastic members 230 and 240 in the direction in which the barrier blades 40 and 50 are closed. Therefore,
Even if there are variations in the dimensions of the bosses of the barrier blades, it is possible to prevent a so-called unopened portion, which is a gap between the barrier blades when the barrier blades are closed.

Next, the assembling work of the barrier mechanism according to the present invention will be described. Holes 42, 5 in barrier blades 40, 50
2 and the holes 61 and 63 of the barrier blades 62 and 64 in the decorative plate 10
By being inserted into the support shafts 12 and 14 and attached with the barrier mounting plate 20, the barrier blade is held between the decorative board 10 and the barrier mounting plate 20 to form an integral barrier block. At this time, the bosses 41 and 51 of the barrier blades 40 and 50 are projected from the openings 22 and 24 of the barrier mounting plate 20, and
Elastic members 210, 220, second elastic members 230, 240
Has not yet been transformed. Then, the opening 22
The first elastic member 210 and the second elastic member 230 are deformed and hung from the outside and the inside, respectively, on the boss 41 protruding from the first elastic member 220 and the second elastic member 240 on the boss 51 protruding from the opening 24. Deform and hang it from the outside and inside. First elastic members 210, 220
Since the second elastic members 230 and 240 are respectively connected to the barrier mounting plate 20 at one end, this work can be easily performed, and there is no fear of deformation during the work.
After that, the barrier block is fixed to the lens barrel 100 with the barrier drive ring 30 interposed therebetween, whereby the assembly of the lens barrier mechanism is completed.

[0020]

As described above, according to the present invention, the first elastic member and the second elastic member formed on the barrier mounting plate both urge the bosses of the barrier blades to open the barrier blades, and the barrier driving plate is opened. Since the formed cam member separates the first elastic member from the boss of the barrier blade to close the barrier blade, the opening / closing residue of the barrier blade is prevented and the assembling work is facilitated.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a barrier mechanism according to an embodiment of the present invention.

FIG. 2 is a front view showing the barrier mechanism of the embodiment of the present invention.

FIG. 3 is a front view showing the barrier mechanism of the embodiment of the present invention.

FIG. 4 is a front view showing the barrier mechanism of the embodiment of the present invention.

FIG. 5 is a front view showing the barrier mechanism of the embodiment of the present invention.

[Explanation of symbols]

10 Veneer 20 Barrier mounting plate 30 barrier drive ring 40, 50 First barrier blade 41, 51 boss 62, 64 second barrier blade 100 lens barrel 210, 220 first elastic member 220, 240 Second elastic member 310, 320 cam member

Claims (7)

(57) [Claims] 1. A lens barrier mechanism of a camera having a plurality of blades for opening and closing a photographing opening of a photographing lens, the plurality of blades including at least one driving blade, wherein the driving blade is rotatably held. A support shaft, a boss formed at an end of the drive blade, a first elastic member that biases the boss in a direction in which the drive blade rotates in a first direction, the boss, A second elastic member that urges the drive blade in a direction to rotate in a second direction opposite to the first direction; and a separating unit that separates the first elastic member from the boss. The second elastic member is weaker than the first elastic member, and when the first elastic member and the second elastic member both urge the boss, the drive blade rotates in the first direction, and Separating means separates the first elastic member from the boss, By only two elastic members for urging the boss, a lens barrier mechanism, characterized by rotating the drive blade in a second direction. 2. The camera according to claim 1, wherein the first direction is a direction in which the drive blade is opened and the second direction is a direction in which the drive blade is closed. Lens barrier mechanism. 3. The camera according to claim 1, wherein the first direction is a direction that closes the drive blade, and the second direction is a direction that opens the drive blade. Lens barrier mechanism. 4. The lens barrier mechanism for a camera according to claim 1, wherein the first elastic member and the second elastic member are shaped portions formed on a mounting plate for mounting drive blades. 5. The plurality of blades comprises at least one drive blade and at least one driven blade, and the driven blade is engaged with the drive blade to provide a position between an open position and a closed position. The lens lens barrier mechanism of the camera according to claim 1, wherein the lens lens barrier mechanism moves. 6. The lens barrier mechanism for a camera according to claim 1, wherein the separating means is a cam-shaped portion formed on a drive ring that slides in the camera barrel. 7. The lens barrier mechanism for a camera according to claim 1, wherein the support shaft is a shaft portion formed on a decorative plate.