JP3129768B2 - Barrier for lens barrel - 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 barrel barrier used in place of a lens cap of a camera lens barrel.

[0002]

2. Description of the Related Art An example of this type of barrier for a lens barrel is proposed by the present applicant in Japanese Patent Application No. 3-90592. FIGS. 5 and 6 show this lens barrel barrier.
This will be described with reference to FIG. In FIG. 5, a lens barrel barrier 2 is mounted on the tip of a lens barrel 1. In the exploded perspective view of the lens barrel barrier 2 shown in FIG. 6, a drive ring 5 rotatable around an optical axis is disposed between a ring-shaped front frame 3 and a rear frame 4. A pair of operation knobs 6 are fixed at 180 ° symmetrical positions outside the ring 5.

A first blade group 7 composed of three blades 7a, 7b, 7c has a base portion of each blade coaxially pivotally connected to the front frame 3 by a pivot pin 8, and each of the blades has a base. At the tip end, a pair of pins arranged opposite to the front and back surfaces of the middle blade 7b are slidably fitted to the slots of the upper and lower blades 7a and 7c, and are pin-slot-connected. And each blade 7a,
7b and 7c are arranged substantially in a row in a folded open state, and in a spread closed state, the respective blades are shifted from each other to cover more than half of the opening. 6, an operating pin 7a 'is fitted in the uppermost blade 7a so as to slide into the elongated hole 5a of the drive ring 5.
The blade 7a is operated in conjunction with the rotation of the blade, and the blade 7b and the blade 7c, which are connected to the pin-slot, are sequentially linked.

A second blade group 9 is coaxially pivotally connected to the rear frame 4 by a pivot pin 10 similarly to the first blade group 7, and the tip of each blade is connected to a pin / slot. And is configured similarly to the first blade group 7.

[0005]

However, in the above-described structure, two pins and slots are required to connect the blade groups to each other, and the driving mechanism for the blade groups is also different. Since a pin and a slot are required for each blade group, the configuration is relatively complicated, the assembling work is complicated, and the manufacturing cost is increased.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a barrier for a lens barrel, which can simplify the structure and reduce the manufacturing cost.

[0007]

A barrier for a lens barrel according to the present invention comprises a plurality of blades of a first blade group and a second blade.
The blades of the group are connected to the drive holes of all the blades.
By the drive pin of the fitted drive member, it turns in the opposite direction.
Rotated to open and close, and multiple for each blade group
The number of blades
Both are different and the amount of overlap is less when closed
Lens barrel cover designed to be large when fully open
At the rear, a plurality of blades for each blade group
And each of said drive holes is pivotally mounted on
The drive pin is only used during the operating time of the blade, and when the blade is fully opened and closed.
And at least one other blade is activated
When it is
It is characterized by being formed .

[0008]

When the drive pins are operated at the time of opening / closing operation, each blade is pushed by the drive pin according to the shape of each drive hole, and the blade having a large operation stroke is interlocked over the entire operation range of the drive pin. Blades with a small working stroke will be opened or closed by interlocking in a partial area of the working range.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The same parts as those in the above-described prior art are denoted by the same reference numerals, and description thereof will be omitted. FIG. 1 shows a closed state of the lens barrel barrier 2 and FIG. 2 shows an opened state thereof, and the front frame 3 and the rear frame 4 are not shown. In the figure, reference numeral 12 denotes an intermediate ring which is fixedly disposed between the front frame 3 and the rear frame 4 instead of the driving ring 5 and has a peripheral wall 12a having a T-shaped cross section on the outer peripheral surface, and 13 denotes an intermediate ring 12 and a rear frame. 4
A first blade group consisting of two blades, which is pivotally attached to a pivot pin 14 fixed to the intermediate ring 12 or the rear frame 4 between them, 15 of which are located near the pivot pin 14. A substantially crescent-shaped first blade 16 having a substantially trapezoidal first hole 15a formed therein and a stopper pin 15b abutting on the peripheral wall 12a of the intermediate ring 12 when the blade is closed, is also a substantially oval-shaped second hole 16a. This is a substantially crescent-shaped second blade having the following.

Reference numeral 17 denotes the rear frame 4 (or the intermediate ring 12).
And a drive pin 19 provided at its free end with a drive pin 19 which slides into the first and second holes 15a, 16a. The drive lever 17 has a slot 17a formed therein. And is urged in the closing direction of the blade by a spring S having a closing behavior. The drive pin 19 is provided on the intermediate ring 1 formed on the intermediate ring 12.
2, and protrudes toward the front frame 3 (back side of the drawing) through the elongated hole 12b in the width direction of the second frame. For example, an eccentric shaft 20 of an electric motor (not shown) provided on the camera body side is slidably fitted in the slot 17a, and by driving this motor at a predetermined angle, the driving pin 19 is substantially in the elongated hole 12b of the intermediate ring 12. The drive lever 17 is moved back and forth within the range.
Are linked.

The interlocking relationship between the drive pin 19 and the first blade group 13 will be described.
Since 5a is trapezoidal, it is pushed at the final stage of the rotation stroke of the drive pin 19, and its operation stroke, that is, the rotation angle is relatively small. Further, the second blade 16 is provided with the second hole 16.
Since a is substantially oval, the drive pin 19 is pushed over the entire rotation stroke, and its operation stroke, that is, the rotation angle is large.

Next, reference numeral 22 denotes a pivot pin 2 fixed between the intermediate ring 12 and the front frame 3 between the intermediate ring 12 and the front frame 3.
A second blade group pivotally attached to 3 and comprising two blades is arranged symmetrically with the first blade group 12. Among them, 24 is a substantially crescent-shaped third blade having a substantially trapezoidal third hole 24a and a stopper pin 24b which comes into contact with the peripheral wall 12a of the intermediate ring 12 when the blade is closed, and 25 is also a substantially oval-shaped fourth hole. The third blade 24 is a substantially crescent-shaped second blade having a first blade 15 and a fourth blade 2.
5 has the same shape as the second blade 26 including the respective holes and is symmetrically arranged. The third hole 24a and the fourth hole 2
The drive pin 19 also slides on 5a.

Since the present embodiment is constructed as described above, a switch (not shown) is turned ON to release the barrier from the closed state of the lens barrel barrier shown in FIG.
When the motor is driven by a predetermined angle, the drive lever 17 is turned counterclockwise via the eccentric shaft 20 against the biasing force of the spring S. Then, the second hole 16a and the fourth hole 25a
The second and fourth blades 16, 2 pushed by the drive pin 19 at
5, the first blade 15 and the third blade 24 do not operate in the initial stage because the drive pin 19 moves in the trapezoidal first and third holes. And the drive pin 19
The first and third blades 1 pushed by the drive pin 19 through the first hole 15a and the third hole 24a in the final region of the rotation stroke of
5 and 24 are opened, and the first blade group 13 and the second blade group 22 reach the open state shown in FIG.

When the motor is turned off to close the lens barrel barrier after the photographing is completed, the drive lever 17 is turned clockwise by the biasing force of the spring S. Then, similarly to the above-mentioned case, first, the second and fourth blades 16 and 25 are interlocked and closed, and then the first and third blades 15 and 24 are pushed by the drive pin 19 and the first and third blades 15 and 24 are pushed. The blade group 13 and the second blade group 22 reach the closed position shown in FIG. At this time, the stopper pins 15b and 24b of the first blade 15 and the third blade 24
In order to abut against the second peripheral wall 12a, each blade is stopped at that position. This prevents excessive rotation of each blade.

In the last region of the left-handed rotation of the drive lever 17,
An open / close recognition switch 27 including a pair of contacts 27a and 27b as shown in FIG. 6 may be provided. In this case, when the blade groups 13 and 22 are opened, one contact 27a is pushed by the drive lever 17 and comes into contact with the other contact 27b, so that the switch becomes ON and the barrier open state can be displayed.

The driving lever 17 is replaced with the spring S.
A spring having an opening behavior may be attached to the blade, and the blade may be operated in the closing direction by driving a motor.
Alternatively, the opening and closing operation of the blade may be controlled only by the motor without attaching a spring.

As described above, according to the present embodiment, the first blade group 13 and the second blade group 22 can be opened and closed by one drive pin 19, and there is no need to connect the blades. Therefore, the number of parts can be reduced, the configuration can be simplified, and the manufacturing cost can be reduced.

[0018]

FIGS. 3 and 4 show a modification of the above-described embodiment, in which a drive lever 1 is used instead of an electric motor.
7 is operated manually to open and close the blades. In this case, an operation portion 29 is connected to the drive lever 17 on the side opposite to the drive pin 19 with respect to the base shaft 18, and the operation portion 29 has a free end projecting outward from the outer periphery of the lens barrel barrier 2. Is formed. Further, a click groove 17c is provided in the drive lever 17, and a click spring 31 having projections 31a and 31b formed at both ends is attached to the rear frame 4 (or the intermediate ring 12) by a fixing pin 30 (see FIG. 4). When the blade is closed by the operation of the drive lever 17, the click groove 17 of the drive lever 17 is closed.
The interval and position of the projections 31a and 31b are set such that one projection 31a fits into the c and the other projection 31b fits in the blade open position.

Therefore, when the photographer operates the operating section 29 to open and close the blade, the drive lever 17 is semi-fixed by the click spring 31 at the closed position and the open position of the blade. For this reason, there is an advantage that an electric mechanism such as an electric motor becomes unnecessary and the structure can be simplified, and the tactile sensation at the closed position and the open position at the time of operation can be improved by the click mechanism.

The drive lever 17 and the click mechanism need not necessarily be disposed between the rear frame 4 and the intermediate ring 12, but may be provided between the front frame 3 and the intermediate ring 12 or outside the lens barrel barrier 2. It may be arranged. Also, the first hole 15a, the second hole 16a, the third hole 24a, and the fourth hole 25
“a” constitutes each drive hole, and the shape of each hole can be appropriately set according to the operation stroke of each blade.

[0022]

As described above, the barrier for the lens barrel according to the present invention has a single hole in each of the driving holes of the first and second blade groups formed in a shape corresponding to the opening / closing operation stroke. Since the drive pins are made to slide, the number of parts is reduced, the configuration can be simplified, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a barrier for a lens barrel according to an embodiment of the present invention, showing a blade closed state.

FIG. 2 is a plan view of a main part in a blade open state.

FIG. 3 is a main part plan view showing a modification of the first embodiment.

FIG. 4 is a sectional view of a main part showing a click mechanism of the barrier for the lens barrel in FIG. 3;

FIG. 5 is a perspective view of a lens barrel on which a barrier for the lens barrel is mounted.

FIG. 6 is an exploded perspective view of a prior art barrier for a lens barrel.

[Explanation of symbols]

 3 Front Frame 4 Rear Frame 13 First Blade Group 15 First Blade 15a First Hole 16 Second Blade 16a Second Hole 17 Drive Lever 19 Drive Pin 22 Second Blade Group 24 Third Blade 24a Third Hole 25th Four blades 25a Fourth hole

Claims (1)

(57) [Claims] 1. A plurality of blades of a first blade group and a second blade.
The plurality of blades of the root group are the driving holes of all the blades.
In the opposite direction by the drive pin of the drive member fitted to
It is rotated to open and close, and multiple
Opening / closing operation stroke and opening / closing operation time for several blades
Are different, and the amount of overlap is smaller when closed.
For lens barrels configured to be large when fully open
A plurality of blades for each blade group
Pivotally mounted on a shaft and each of said drive holes is
Drive only during the operating time of each blade, and when fully open and closed
Contacts the pin and only at least one other blade is activated
Shape that can be separated from the drive pin when
Burr for a lens barrel characterized by being formed in
Ya.