JP2556334Y2 - Optical equipment blade opening and closing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a barrier for a lens barrel used in a lens barrel of a camera, and a blade opening / closing device such as a shutter.

[0002]

2. Description of the Related Art Conventionally, in a video camera, a still camera, or the like, a lens cap is attached to a lens barrel to protect a front lens of the lens barrel. However, this must be removed at the time of shooting. It was very inconvenient and sometimes lost. In order to eliminate such inconvenience, for example, in a still camera, a barrier for a lens barrel having two blades has already been used. However, a two-piece blade has a disadvantage that it goes against the demand for a more compact camera because the barrier becomes large, and the two-piece blade has a cantilever structure, so that it is easily bent and tilts during operation. On the other hand, there is a drawback that the durability is poor.

On the other hand, a barrier for a lens barrel in which a pair of blades composed of a plurality of substantially crescent-shaped blades is provided and opened and closed by folding and expanding the blades is disclosed by the present applicant. I Rutokunegaitaira 3-90
592 (Japanese Unexamined Patent Publication No. 5-61104) . In such a barrier for a lens barrel, each blade group is composed of three blades, and the front and rear frames are sandwiched between a front frame or a rear frame and a drive ring, thereby suppressing the tilt of the blade. It has become. And this
The configuration of the barrier has an advantage that it can be made smaller than the above-described two-layer configuration .

[0004] However, in such a structure, in a state where the blades are overlapped around the inside of the barrier with a large overlap ,
There are few blade areas that do not overlap each other,
No need to worry about the product moving or bending in the optical axis direction
However, with the lens expanded and protected from this state
Is large in the area of each blade that does not overlap
Between that part and the surface of the member
In, because she can between relatively large empty <br/> of one or two sheets in the thickness of the blade, is manufactured of a plate material blades have thin
That it even, there is a problem that interfere with the operation of the vane occurs tilt at the time of vane actuation.

Such a problem occurs not only in a barrier for a lens barrel but also in, for example, a shutter blade of a camera shutter device and a blade of a diaphragm device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to provide a blade opening / closing apparatus for an optical apparatus which can prevent the blade from tilting at the time of opening / closing operation of the blade. It is.

[0007]

According to the present invention, there is provided a blade opening / closing device for an optical apparatus , wherein a space is provided between respective flat portions.
And centered on the optical axis by both
Two members forming a circular opening, and in the space
With one end pivotally attached to one of the two members
The position where the overlap is increased and the position where the overlap is reduced
Opening and closing the opening by reciprocating between
And a plurality of blades, wherein at least
By providing a plurality of steps on one side,
A plurality of different planes are formed in each of the plurality of blades.
Are actuated substantially along each of said planes,
The stepped portion has a shape corresponding to the operating direction of at least one of the blades.
It is characterized by being formed corresponding to the shape .

[0008]

When each of the blades is opened or closed to reach the open position or the closed position, each blade comes into contact with a step portion to restrict the rotation, and the back surface or surface of the blade is a flat surface following the step. Is located, there is no space for the thickness of the other blades at that position, and tilting can be prevented and the operation becomes smooth.

[0009]

1 to 4, a first embodiment of the present invention applied to a barrier for a lens barrel will be described in detail. In FIG. 1, 1 is a lens barrel, 2 is a lens barrel 1
3 is a barrier for a lens barrel according to the present embodiment, which is mounted at the tip of the lens barrel. In the lens barrel barrier 2 shown in FIG.
Reference numeral 3 denotes a ring-shaped front frame, 4 denotes a ring-shaped rear frame, 5 denotes a drive ring disposed between the frames 3 and 4 and is rotatable around the optical axis, and 6 denotes a drive ring. This is a pair of operation knobs fixed at 180 ° symmetrical positions on the outer peripheral portion.

Reference numeral 7 denotes a first blade having three blades 7a, 7b, 7c, each base portion being pivotally coaxially mounted on the front frame 3, and having a tip and a slot between adjacent blades. And 8 are pivot pins for coaxially connecting the bases of the three blades 7a, 7b, 7c to each other.
The b and 7c are arranged substantially in a line in a folded state, and when spread, the respective blades are shifted from each other so as to cover more than half of the opening. An operating pin 7a 'sliding on the elongated hole 5a of the drive ring 5 is provided on the uppermost blade 7a in FIG.
The blade 7a is operated in conjunction with the rotation of the drive ring 5, and the blade 7b and the blade 7c, which are connected to the pin-slot, are sequentially linked.

Next, similarly to the first blade group 7, the base 9 is coaxially pivotally connected to the rear frame 4 by a pivot pin 10, and the leading end between adjacent blades is connected by a pin / slot. This is a second blade group, and the specific structure is the same as that of the first blade group 7, and therefore detailed description thereof is omitted. Also, the second
Are arranged at positions symmetrical with respect to the optical axis with respect to the first blade group 7 and shifted in the optical axis direction with the drive ring 5 interposed therebetween.

The above structure is disclosed in Japanese Patent Application No. Hei.
90592(JP-A-5-61104).
ThingIs the same as Next, FIG. 3 is a plan view of the front frame 3,
FIG. 4 is a cross-sectional view taken along line AA of FIG.
Ring shape of front frame 3Actuation of the first blade group 7 on the flat part
Three planes 3a, 3a having different heights in the optical axis direction.
3a 'and 3a "are formed.12 is the first feather
The uppermost blade 7a of the root group 7 abuts at the closed position and is closed.
The first stage 13 whose movement is regulated, 13 is the middle stage of the first blade group 7
Of the blade 7b abuts in the closed position, 14 is the first step.
The blade 7c located at the bottom of the blade group 7
The third step that touches, each step12, 13, 14 are each
It is formed in the shape of a slope, and those steps are almost
a, 7b, 7c.
The same applies to the rear frame 4.And thenOf the second wing group 9
In the closed position, each blade 9a, 9b, 9c abutsThree
It is assumed that each step is formed.

Since the present embodiment is configured as described above, the knob 6 is rotated from the open state in which the first blade group 7 and the second blade group 9 are folded, or not shown. By the urging force of the spring, both blade groups 7, 9
When the blades are closed, the blades 7a, 7b, 7c and 9
a, 9b and 9c are respectively operated to close in conjunction with each other. At this time, the tip of the blade 7a is in the area of the plane 3a ″.
Through the area of the plane 3a ', but the steps 14 and 13
Does not touch, even if it touches, it is guided by the slope and proceeds
I do. The tip of the blade 7b also advances to the area of the plane 3a ".
However, it does not come into contact with the step 14, and even if it does,
Proceed under the guidance of. Then, in the closed position, the blades 7a, 7b, 7c of the first blade group 7 abut on the slopes of the steps 12 , 13 , 14 at predetermined positions and stop as if climbing up.

In this state, the blade 7a comes into contact with the step 12
Therefore, it cannot move downward in FIG. And
Even if the blades 7b or flat
Deformation can be suppressed by the surface 3a '. On the other hand,
The upward movement is suppressed by the drive ring 5.
From this, other feathers need not be explained again.
Similarly, the positions of the roots 7b and 7c are regulated in the optical axis direction.
It is. This is the same for the second blade group.

As described above, in the barrier 2 for a lens barrel according to the present embodiment, the steps 12, 13, and
14 is formed , of course, at the open position of the blade .
That each blade, both in the middle and in the closed position,
Is restricted in the direction of the optical axis , and it is possible to prevent the occurrence of tilt during the operation of the blade.

Next, a second embodiment in which the present invention is applied to a shutter will be described with reference to FIGS. FIG. 5 is a plan view showing the closed state of the shutter, and FIG. 6 is a plan view showing the opened state of the shutter. In the figure, reference numeral 16 denotes an exposure opening formed in the shutter base plate P, reference numerals 17 and 18 denote a pair of shutter blades which open and close the exposure opening 16 around support shafts 19 and 20, respectively, and reference numeral 21 denotes two shutter blades 17. , 18 is a motor having an eccentric drive pin 21a pin-slot-coupled to each of the slots 17a, 18a. When the motor 21 is turned clockwise, the shutter blades 17, 18 are opened, and when the motor 21 is turned counterclockwise, the motor 21 is opened. It is designed to operate closed.

Reference numeral 23 denotes a fully opened position of the shutter blade 17 located on the upper side, and a first step portion formed on the shutter base plate for restricting the opening operation of the blade 17; 24, a closing of the shutter blade 18 located on the lower side. This is a second step formed on the shutter base plate to restrict the closing operation of the blade 18 at the position, and the steps of these steps 23 and 24 have heights corresponding to the plate thicknesses of the shutter blades 17 and 18 respectively. As shown in the cross-sectional view of FIG. 7, the shutter base plate P is formed in a step-like manner through the planes Pa ′ and Pa of the shutter base plate P. Moreover, each of the steps 23 and 24 has a shape partially corresponding to the contour of each of the shutter blades 17 and 18 at the contact position. A plane (not shown) is also arranged above the upper shutter blade 17, and the two shutter blades 17,
18 is sandwiched together with the shutter base plate P.

Since the present embodiment has the above-described configuration, the shutter blades 17, 1 from the closed state shown in FIG.
When the shutter 8 is opened, the blade 17 slides along the plane Pa 'and the blade 18 slides along the plane Pa, and the upper shutter blade 17 is moved to the first step portion 23 in the open position shown in FIG.
Stop in contact with. When the closing operation is performed from the open state, the blades 17 and 18 also slide along the planes Pa ′ and Pa, and the lower blade 18 contacts the second step portion 24 in the closed position shown in FIG. And stop. Therefore, also in the case of the present embodiment, the movement of the shutter blade in the optical axis direction in the blade operation process from the open position to the closed position can be substantially eliminated, and the occurrence of tilt can be prevented, and the operation of the blade can be further improved. It can be smooth.

In the second embodiment described above, of the two planes sandwiching the blade, only the stepped portion 23,
Although the step 24 is formed, a step may be formed on each of both planes. In this case, the operation and stop positions of the blades are regulated from the vertical direction, so that it is more effective to prevent tilt. is there.

It is needless to say that the number and shape of the steps are not limited to those in the embodiment, but may be appropriately selected depending on the number of blades and the surrounding structure.

[0021]

As described above, the blade opening / closing device of the optical device according to the present invention is provided with the step for regulating the operation of the blade at the open or closed position of the blade, so that the tilt of each blade can be prevented. Thus, the operation can be further smoothed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lens barrel including a lens barrel barrier according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the barrier for the lens barrel shown in FIG.

FIG. 3 is a plan view of a front frame of the barrier for the lens barrel according to the first embodiment.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a plan view showing a closed state of a shutter according to a second embodiment of the present invention.

FIG. 6 is a plan view showing an open state of a shutter.

FIG. 7 is a sectional view taken along the line BB of FIG. 6;

[Explanation of symbols]

 2 Barrier for lens barrel 3 Front frame 4 Rear frame 5 Drive ring 7 First blade group 9 Second blade group 12, 23 First step 13, 24 Second step 14 Third step 17, 18 Shutter Blade P Shutter base plate

Claims (1)

(57) [Scope of request for utility model registration] (1) A space is provided between respective flat portions.
Around the optical axis by both
Two members forming an opening of
With one end pivotally attached to one of the two members.
Between the position where the overlap is increased and the position where the overlap is decreased
Open and close the opening by reciprocating
And at least one of the flat portions
By providing a plurality of steps on one side, it is different in the optical axis direction.
Are formed, and each of the plurality of blades is
Actuated substantially along each of said planes,
The part has a shape in the operating direction of at least one of the blades.
A blade opening / closing device for an optical device, which is formed correspondingly .