JP2597002Y2 - Blade structure of 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 barrier for a lens barrel used for protecting a lens surface of a lens barrel of a camera.

[0002]

2. Description of the Related Art As an example of this type of barrier for a lens barrel, the applicant of the present invention has disclosed Japanese Patent Application No. Hei.
No. 1104) . This lens barrel barrier will be described with reference to FIGS. FIG. 5 shows a lens barrel barrier 1 mounted at the tip of the lens barrel.
FIG. 2 is an exploded perspective view of the first embodiment. A drive ring 4 rotatable around an optical axis is disposed between a ring-shaped front frame 2 and a rear frame 3. A pair of operation knobs 5 are fixed at symmetrical positions.

In a first blade group 7 composed of three blades 7a, 7b, 7c, each base portion of each blade is coaxially pivotally connected to the front frame 2 by a pivot pin 8, and each blade is connected to the other frame. The tips are pin and slot connected to each other. In FIG. 5, the uppermost blade 7a is connected to the drive ring 4 by a pin and a slot.
a is operated, and the blade 7b and the blade 7c, which are connected to the pin and the slot, are sequentially linked.

The second blade group 9 is coaxially pivotally connected to the rear frame 3 by a pivot pin 10 like 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] The first and second blade groups 7, 9 are
In the unfolded closed state, the blades are offset from each other and cover more than half of the openings, respectively, to close the opening, and in the folded open state, the blades are each substantially in line. FIG. 6 is a sectional view showing a portion where both blade groups overlap each other. Here, the front frame 2, the rear frame 3, and each blade are each formed in a rectangular cross section, and the angle of incidence of the incident light beam when opened is limited by the inner diameter of the front frame 2. The inner diameter surface, that is, the inner end surface of the rear frame 3 is moved from the blade 7c on the front frame 2
It is formed in a substantially stepped shape over.

[0006]

However, even with such a configuration, in the lens barrel barrier, one blade is required because of the space required for storing the blades when the blades are opened and the need to reduce the size of the apparatus. Since the width of the inner and outer diameters, that is, the area, must be reduced, the number of blades increases, resulting in a complicated configuration and an increase in the number of parts, which raises a problem that the manufacturing cost increases.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention makes it possible to increase the size of a blade without expanding the blade storage space when the blade is opened, to reduce the number of blades, and to reduce the manufacturing cost. It is an object of the present invention to provide a blade structure of a barrier for use.

[0008]

According to the present invention, a blade structure of a barrier for a lens barrel comprises two frames between a first frame and a second frame .
Blades are arranged facing each other and they are operated in opposite directions
To open and close the opening, and in the state where the opening is opened
Is a barrier for the lens barrel in which each blade is superimposed on each blade group.
At least one blade is in the state where the opening is opened.
The end face on the opening side that matches the shape of the opening
It is formed in a pa shape, and in the state where the opening is opened
Indicates that the extension of these tapered surfaces is
Is formed so as to cross the optical axis .

[0009]

In the open state of the blade, the opening-side end face of the tapered blade stops at a position along the incident light beam, and the width of the blade can be increased in the optical axis direction only by this tapered portion. The blade storage space does not change.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 3. FIG. 1 shows a closed state of the lens barrel barrier 2, and FIG. 2 shows an opened state thereof, and the front frame 2 and the rear frame 3 are not shown. In the drawing, reference numeral 12 denotes an intermediate ring which is fixedly disposed between the front frame 2 and the rear frame 3 instead of the drive ring 4 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 front frame. 2
And a first blade group consisting of two blades, which is pivotally connected to a pivot pin 14 fixed to the intermediate ring 12 or the front frame 2 between the first ring 15 and the first blade group 15. A substantially crescent-shaped first blade having a hole 15a and a stopper pin 15b abutting on the peripheral wall 12a of the intermediate ring 12 when the blade is closed;
Reference numeral 16 denotes a substantially crescent-shaped second blade having a substantially oval-shaped second hole 16a.

Reference numeral 17 denotes a drive lever which is located on the rear frame 3 side of the intermediate ring 12 and is pivotally mounted on a base shaft 18 fixed to the rear frame 3 (or the intermediate ring 12). The slot 17a is bored and urged in the closing direction of the blade by a spring S having a closing behavior. Reference numeral 19 denotes a drive pin provided at the free end of the drive lever 17, which penetrates through the elongated hole 12b in the width direction of the intermediate ring 12 and forms the first and second holes 15a, 16a. While sliding, it also protrudes to the rear frame 3 side (back side of the paper). 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. Drive lever 1 so as to reciprocate within the range.
7 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 rear frame 3 between the intermediate ring 12 and the rear frame 3.
A second blade group pivotally attached to 3 and comprising two blades is arranged symmetrically with the first blade group 12. The blade group 22 includes a third blade 24 having a substantially trapezoidal third hole 24a and a stopper pin 24b, and a fourth blade 25 having a substantially oval fourth hole 25a.
The first blade 15 and the fourth blade 25 have the same shape as the second blade 26 including the holes, and are arranged symmetrically. The driving pin 19 is also provided in the third hole 24a and the fourth hole 25a.
Is to slip.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, which is a portion where the first blade group 13 and the second blade group 22 are overlapped, and the front frame 2 and the rear frame 3 are also shown. It is drawn. In the figure,
Inner end surfaces 2p and 3p of the front frame 2 and the rear frame 3 are formed in a tapered shape along the incident light beam 1 incident on the lens barrel. Each of the first blade group 13 and the second blade group 22 is manufactured by molding synthetic resin, and the first blade 15, the second blade 16, the third blade 24, the fourth blade Each inner end face 15p, 16p, 24p, 25p of the blade 25
Are also formed in a tapered shape substantially along the incident light beam l.

Therefore, in FIG. 4, when the blade 15 according to the present embodiment is compared with, for example, the blade 7a according to the prior art, the difference in the inner and outer diameters of the blade 15 is larger in the blade 15 by the length m of the tapered portion 15p. In addition, since this portion is a useless space in the barrier for the lens barrel according to the prior art structure, it is not necessary to expand the blade storage space when the blade is opened due to the blade width of the tapered portion 15p. This is the same for the other blades.

Since this embodiment is constructed as described above, a switch (not shown) is turned ON to open 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.

At this time, the first blade group 13 and the second blade group 22 are respectively superposed in a line, and the inner end face 15 of each blade is arranged.
p, 16p, 24p, 25p are aligned at positions along the incident ray l, as shown in FIG. Therefore, the incident light beam necessary for photographing is transmitted to the inner end surfaces 2 of the front frame 2 and the rear frame 3.
p, 3p and the inner end faces 15p, 16p, 24 of each blade
The light enters the lens barrel along p and 25p.

When the barrier for the lens barrel is closed after photographing, the motor is turned off and 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, each blade has a light shielding area larger than that of the prior art blade by the width m of the tapered portion.

As described above, according to this embodiment, the width of each blade, that is, the difference between the inner and outer diameters can be increased without increasing the blade storage space when the blades are opened, so that the number of blades can be reduced. As a result, the number of parts can be reduced and the configuration can be simplified, and the manufacturing cost can be reduced.

If the blade width is not changed, the outer diameter can be reduced by the width m, and the lens barrel barrier 2 can be reduced in size.

In the above-described embodiment, all the blades are molded to form an inner end surface in a tapered shape. However, only some of the blades having substantially large effects are appropriately selected. Such a configuration may be adopted.

[0022]

[0023]

As described above, the blade structure of the barrier for the lens barrel according to the present invention has two blade groups.
At least one blade for each blade group of people, the opening side end surface of that is being formed in a tapered shape, like an open the opening
In this case, the extension of the tapered surface is
It is formed so as to intersect the optical axis on the part side
Since the sea urchin, it is possible to increase the width of the blade without increasing the storage space of the blade, thereby can become able to simplify the barrier structure to reduce the number of blades, the manufacturing cost inexpensively Has the practical advantage of being able to Also, taper as above
By forming the Jo surface, on the opposite, since it is possible to reduce the outer diameter of the blade, it is also possible to ing to miniaturize the lens barrel for barrier.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a barrier for a lens barrel according to the present invention, and is a plan view of a main part of a blade closed state viewed from a front frame direction.

FIG. 2 is a plan view of an essential part in a blade open state similar to FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

4 shows a cross-section of the inner and outer diameters of the blade according to FIG. 3 and the blade according to the prior art.

FIG. 5 is an exploded perspective view of a barrier for a lens barrel according to the prior art.

6 is a partial cross-sectional view of the barrier for the lens barrel in FIG. 5 in a blade open state.

[Explanation of symbols]

 2 Front frame 3 Rear frame 13 First blade group 15 First blade 15p Inner end surface 16 Second blade 16p Inner end surface 17 Drive lever 19 Drive pin 22 Second blade group 24 Third blade 24p Inner end surface 25 Fourth blade 25p Inside edge

Claims (1)

(57) [Scope of request for utility model registration] An opening is opened and closed by operating two blade groups facing each other between a first frame and a second frame and operating them in opposite directions to open and close the opening. In the state, each feather
In a lens barrel barrier in which each blade is overlapped for each root group , at least one sheet is provided for each blade group.
The blade has the shape of the opening when the opening is opened.
The opening-side end face that has been fitted has a tapered shape.
And when the opening is open,
The extension of the tapered surface crosses the optical axis inside the lens barrel.
A blade structure characterized by being formed as described above .