JPH0446263Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a blade support structure for a focal plane shutter for a camera.

[Prior art and its problems]

A conventional example of a blade support structure for a focal plane shutter for a camera, as shown in FIGS. 4 and 5, includes a substrate 1 and at least a first blade for forming a slit for opening and closing an aperture 1a. 2a and second blades 2b, 2c, 2 for covering
a first arm pivotally attached to the substrate 1, the first blade 2a, and the second blades 2b, 2c, 2d, and 2e at different locations, respectively; 3, the substrate 1, the first blade 2a, and the second blade 2b, 2.
c, 2d, and 2e at different locations, and a second arm 4 forming a parallel link with the first arm 3; It has a drive arm 5 that is concentric with the pivot point 3a of the first arm 3 and rotates the first arm 3 by a predetermined amount, and is concentric with the pivot point 3a of the first arm 3 and the substrate 1. and a drive arm 5 for rotating the first arm 3 by a predetermined amount, and the first blade and the second blade are arranged in order from the one farthest from the pivot point of each arm to the substrate. It is pivoted. Then, two sets of the above configuration are placed upside down and facing each other with an intermediate plate in between.
They constitute an open blade group and a closed blade group, respectively.

In this conventional example, since one pivot portion 3c of the second blade 2b is on the first arm 3, the connecting portion of the first arm 3 to the drive arm 5 (the pin 5a of the drive arm 5 is fitted) The matching hole 3h) had to be set far from the center of the aperture 1a in the vertical direction so as not to interfere with the pivot portion 3c.

Therefore, the distance between the operating area ends of the drive arms 5, 9 between the open blade group and the closed blade group is as wide as _L1 , and the drive block including the drive arms 5, 9 stacked on the substrate 1 on the opposite side of the blade group. (The thickness of the drive block is about 15 mm, which is thicker than the blade group block of about 1.7 mm.) The dimensions of the aperture increase in the vertical direction, which limits the ability to incorporate the shutter unit into the camera.

To solve this problem, the length of the arm can be made longer and the connection part can be set closer to the pivot point with the board than the pivot part of the blade closest to the board. Although it is possible to reduce the vertical dimension of the shutter unit, on the other hand, the horizontal dimension of the shutter unit becomes larger by the length of the arm, making the entire shutter unit larger.

[Purpose of invention]

The present invention enables the connecting portion between the drive arm and the arm supporting the blade to be located on the side closer to the center of the aperture in the vertical direction.
without increasing the size of the shutter unit.
An object of the present invention is to provide a blade support structure for a focal plane shutter for a camera, which can shorten the vertical dimension of a drive block.

[Summary of the idea]

The object of the present invention is to provide a substrate, a first blade for forming a slit for opening and closing the aperture,
a second blade group for covering, and a light-shielding blade group having one end pivotally mounted on the substrate, and facing the pivot point with the substrate at different points from the tip of the other end, a first arm to which a first blade and at least one blade closer to the other end of the second blade group are pivotally connected in order; a second arm that is pivotally connected to the first blade and the second blade group at different locations in order from the base plate toward the pivot joint with the substrate, and forms a parallel link with the first arm; and at least one or more second blades, one end of which is pivotally mounted on the substrate, and at least one second blade of the second blade group excluding the arm that is pivotally coupled to the first arm, in order from the side closest to the substrate. a third arm that is pivoted at different locations to form a parallel link with the second arm; a rotation center thereof is concentric with a pivot point between the first arm and the substrate;
a drive arm that rotates the first arm by a predetermined amount, and the drive arm is arranged between the pivot joint of the first arm with the substrate and the pivot joint of the second blade. Since they are connected on the first arm, the blades of the second group of blades other than the blades pivoted on the first arm are pivoted on the third arm, and their pivot points are connected to the first arm. Since the connection part with the drive arm can be placed in the part where the pivot point on the first arm would have been in the case of two conventional parallel links, as a result, this connection This is achieved by a support structure for a focal plane shutter for a camera that allows the camera focal plane shutter to be disposed close to the center of the aperture in the vertical direction.

[Example of idea]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2 of the drawings. Note that the same reference numerals are given to members that perform the same functions as in the conventional example.

That is, the present invention differs from the conventional example in that the third arm 10 is pivotally attached to the substrate 1 and the second blade 2b at different locations, and forms a parallel link with the second arm 4. provided, a second blade 2b
The pivot point is removed from the first arm 3.

As a result, the degree of freedom in setting the shape of the second blade 2b is increased, and the connecting portion (hole) 3h of the first arm 3 with the drive lever 5 can be positioned closer to the vertical center of the aperture 1a. I can do it.

Therefore, as shown in FIG. 2, the distance between the operating area ends of the drive arms 5 and 9 between the open blade group and the closed blade group is
_L2 is narrower, allowing the length of the drive block in the vertical direction to be shortened.

Note that the other covering blade 2c is pivoted in the same manner as the second blade 2b, and the blades 2d,
2e is pivotally mounted in the same way as the first blade 2a.

That is, in the above description, the group of light shielding blades is composed of two blades, a blade for forming a slit and a blade for covering, but as shown in the figure,
When the number of cover blades increases to four, a plurality of blades located on the side closer to the pivot point with the substrate 1 of the first arm 3 are attached to the second arm 4.
It is desirable that the third arm 10 and the third arm 10 be pivotally connected.

Next, FIG. 3 shows another embodiment of the present invention, in which the third arm 10 is relocated above the first arm 3 in the drawing.

[Effect of idea]

As described above, according to the blade support structure of the focal plane shutter for cameras of the present invention, the connecting portion between the drive arm and the arm that supports the blade can be located close to the vertical center of the aperture. The distance between the operating area ends of the drive arms 5 and 9 between the open blade group and the closed blade group is narrowed to _L2 , which allows the vertical dimension of the drive block to be shortened, reducing restrictions when incorporating it into a camera as a shutter unit. , which is practically effective.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a blade group block showing an embodiment of the present invention, and Fig. 2 shows a left and right view of the blade group block and drive block (drive arm) of the present invention, which are stacked with a substrate in between in the direction perpendicular to the plane of the paper. FIG. 3 is a plan view of another embodiment of the present invention, FIG. 4 is a plan view of a conventional blade block, and FIG. FIG. 7 is a plan view showing a conventional blade group block and a drive block (drive arm) which are sandwiched and stacked on top of each other, expanded from side to side. 2a...First blade, 2b...Second blade, 3...First arm, 3h...Connection part, 4
...Second arm, 5...Drive arm, 10...
third arm.

Claims (1)

[Claims for Utility Model Registration] A substrate, a group of light-shielding blades consisting of a first blade for forming a slit for opening and closing the aperture, and a second group of blades for covering, one end of which is attached to the substrate. At least one blade of the first blade and the second blade group on the side closer to the other end is pivoted on the top, and from the tip of the other end toward the pivot joint with the substrate. a first arm which is pivotally connected at different points in order, and a first blade whose one end is pivotally connected to the substrate, and the first blade is connected at different points in order from the tip of the other end toward the pivot point with the substrate. , a second arm that is pivotally connected as a second group of blades and forms a parallel link with the first arm; At least one or more blades other than the blade pivotally attached to one arm are pivoted at different locations in order from the side closest to the substrate,
a third arm forming a parallel link with the second arm; the center of rotation is concentric with the pivot point between the first arm and the substrate; the first arm is rotated by a predetermined amount; a drive arm, the drive arm being connected to the first arm between a pivot joint of the first arm with the substrate and a pivot joint of the second blade. A blade support structure for a focal plane shutter for a camera, which is characterized by: