JP3459691B2 - Shutter 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 shutter device having a mechanism for regulating the aperture diameter of a diaphragm.

[0002]

2. Description of the Related Art It is a well-known fact that the diaphragm of a conventional camera is formed by a diaphragm device composed of a plurality of diaphragm blades or a shutter blade that also serves as a diaphragm. However, with the recent trend toward miniaturization of cameras, most of the lens shutter cameras adopt a shutter system that also serves as an aperture.

However, in a camera having a lens system having a large zoom ratio, the lens system is not complicated and expensive. Therefore, a diaphragm aperture diameter variable mechanism as described below is used to adjust the lens system according to the focal length. The present applicant has proposed that the aperture diameter can always be set appropriately. In other words, in the conventional aperture / shutter device, the aperture opening of a substantially perfect circle smaller than the aperture opening diameter determined by the shutter base plate or the like is formed by the two aperture diameter determining blades. Explaining with reference to FIGS. 6 to 8, a shutter base plate 101 having a diaphragm aperture diameter D is provided with diaphragm-specific blades 102 and 103 having axes 101a and 101b provided on the shutter base plate 101 as rotation centers. . A diaphragm lever 104 that drives the diaphragm-specific blades 102 and 103
Fits on a shaft 101c provided on the shutter base plate 101 and has the shaft 101c as the center of rotation. Aperture lever 10
4, the blade drive pin 104a is integrally formed,
Cam holes 102a and 1 of diaphragm-specific blades 102 and 103
It is fitted to 03a. This allows the aperture lever 104
Is rotated about the axis 101c, the blade 1
Nos. 02 and 103 start to open from the minimum aperture size in the direction of the arrow in FIG. 6 and are driven to form an arbitrary aperture size up to the maximum aperture size. The rectilinear guide 105 is a member that forms a lens barrel of a camera (not shown), and a plurality of lens groups L (not shown) in the rectilinear guide 105 are associated with zooming.
Is moved in the optical axis direction without rotating. Therefore, the lens group L (not shown) including the shutter base plate 101 also moves in the optical axis direction by the straight guide 105 during zooming.

Further, the straight guide 105 has a diaphragm lever 1
04 is provided with a cam portion 105a which is integrally fitted with a cam pin 104b, so that the aperture lever 104 is moved along the cam portion 105a by the movement of the shutter base plate 101 in the optical axis direction by zooming. 10
By rotating around 1c, the blade drive pin 1
By 04a, the blades 102 and 103 dedicated to the diaphragm perform opening and closing movements.

Reference numerals 106 and 107 denote conventional shutter blades that also function as diaphragms, which are fitted to shafts 101d and 101e provided on the shutter base plate 101, respectively, and serve as rotation centers. Also, the shutter blades 106 and 107
Slotted holes 106a and 107a are provided in each of which the drive pin 108 is fitted. When the drive pin 108 is driven in the direction of the arrow in FIG. 8 by a known mechanism (not shown), the shutter blades 106 and 107 move the shaft 101d,
Since it rotates around 101e, the opening and closing movement of the shutter is performed.

As described above, it is possible to obtain an appropriate aperture opening diameter according to zooming through the linear guide and the aperture lever.

[0007]

However, in the above-mentioned conventional example, since the minimum diaphragm opening and the maximum diaphragm opening formed by the blades 102 and 103 for diaphragms are determined by the cam 105a provided in the rectilinear guide 105, the rectilinear guide and The blade for exclusive use of the diaphragm does not form the maximum diaphragm opening due to the completion of parts such as the diaphragm lever, the amount of backlash between the cam part and the cam pin, and the tilting of the diaphragm lever in the optical axis direction. However, there are drawbacks that the optical performance may be adversely affected by the possibility that it may remain unremoved or may not be closed to the minimum aperture opening.

In order to solve the above-mentioned drawbacks, a mechanism for urging the cam portion of the straight-ahead guide and the cam pin of the diaphragm lever in the mutually engaging direction is disclosed, for example, in Japanese Utility Model Laid-Open No. 5-61736. A mechanism is conceivable in which the two members are engaged with each other via a flexible joint portion and the elasticity of the joint portion is used. Since a flexible coupling member must be arranged in the above, the space occupied by the shutter device is increased by that much, especially by the thickness in the optical axis direction, which hinders downsizing of the camera.

Therefore, an object of the present invention is to provide a shutter device having a diaphragm aperture regulating mechanism capable of obtaining a stable minimum diaphragm aperture or maximum diaphragm aperture without adding a new member.

[0010]

According to a first aspect of the present invention, a plurality of diaphragm members provided on a diaphragm base plate for setting different apertures with respect to the aperture open diameter, and a plurality of diaphragm members for opening and closing the diaphragm members. A diaphragm lever rotatably provided on the diaphragm base plate and a cam portion with which the diaphragm lever engages are formed along the optical axis direction, and the movement of the diaphragm lever in the optical axis direction during zooming causes the cam portion to move the diaphragm lever. A shutter device having a straight guide for controlling rotation, and driving the aperture lever by a cam by linearly moving the straight guide to control opening and closing of the plurality of aperture members. A first abutting portion is formed on any one of the two, and a second abutting portion with which the first abutting portion abuts is formed at the position where the plurality of diaphragm members form a minimum diaphragm opening. The first contact portion and the second contact portion are provided on the main plate, and In contact with that state, over tea
The locus of the cam portion to the first contact
Design cam when the contact portion and the second contact portion contact each other
A locus that is shifted a predetermined distance in the closing direction from the locus of the part
Characterized by a.

In this structure, since the driving force for further driving the diaphragm member in the closing direction at the minimum diaphragm opening position acts on the diaphragm lever , the minimum diaphragm opening can be surely performed without being influenced by manufacturing errors such as component manufacturing errors. You can get
It is possible to provide a shutter device satisfying optical performance without requiring a new biasing member.

The second invention is, as described in claim 2,
The second contact portion provided on the diaphragm base plate according to claim 1, wherein the second contact portion is a correction target portion of the minimum diaphragm opening.
By adjusting the abutting portion of, the change in the aperture shape due to the manufacturing error of the diaphragm member can be absorbed, and the minimum diaphragm shape as designed can be obtained.

According to a third aspect of the present invention, a plurality of diaphragm members provided on a diaphragm base plate for setting different apertures with respect to the aperture open diameter and a rotatable base plate for opening and closing the plurality of diaphragm members. And a cam portion with which the aperture lever engages are formed along the optical axis direction, and a linear guide that controls the rotation of the aperture lever by the cam portion due to movement in the optical axis direction during zooming. A shutter device for driving the aperture lever by a cam by linearly moving the linear guide to control opening and closing of the plurality of aperture members,
A first contact portion is formed on any one of the plurality of diaphragm members, and a second contact portion with which the first contact portion abuts is formed at a position where the plurality of diaphragm members form a maximum diaphragm opening. A contact portion is provided on the diaphragm base plate, and in order to make an overcharge state in a state where the first contact portion and the second contact portion are in contact with each other,
The locus of the cam portion is defined by the first contact portion and the second contact portion.
In the opening direction rather than the designed cam locus at the time of contact
It is characterized in that the locus is shifted by a predetermined distance .

In this configuration, contrary to the above-described first configuration, the driving force for further driving the diaphragm member in the opening direction at the maximum diaphragm opening position acts on the diaphragm lever, so that a manufacturing error or the like of component parts is completed. It is possible to provide the shutter device which can surely obtain the maximum aperture without being influenced by the above, and which does not require a new biasing member and which satisfies the optical performance.

[0015]

Embodiments (First Embodiment) FIG. 1 is a plan view of a shutter device according to a first embodiment of the present invention. In FIG. 1, the shutter base plate 1 is provided with diaphragm-dedicated blades 2 and 3 rotatably supported by shafts 1 a and 1 b provided on the shutter base plate 1, respectively. The opening and closing movements of the diaphragm blades 2 and 3 are performed by the diaphragm lever 4 which is rotatably supported by 1c, which is the same as the conventional one, and the details thereof will be omitted.

An R-shaped abutting portion 2c is provided at the tip portion 2b of the diaphragm-specific blade 2, and the shutter base plate 1 is provided with
The abutment portion 2 when the blade 2 dedicated to the diaphragm forms the minimum diaphragm opening
A convex portion 1d is provided at a position facing c, and the contact portion 2c abuts here.

In the above structure, the diaphragm-specific blades 2 and 3
Is gradually closed from the formation of the maximum aperture opening to the minimum aperture opening. Eventually, when the blades 2 and 3 dedicated to the diaphragm form the minimum aperture opening, the contact portion 2c of the blade 2 dedicated to the diaphragm is projected onto the convex portion 1d of the shutter base plate 1. bump into. Therefore, the diaphragm lever 4
It does not rotate further in the closing direction.

Separately from this, when a part of the development view of the straight guide 5 on the inner diameter side is shown in FIG. 2, the locus of the cam portion 6 provided on the straight guide 5 is designed such that the contact portion 2c is the convex portion 1d. In the closing direction from the locus 6a of the cam pin 4b when it hits
The locus 6b is shifted by L ₁ .

That is, the abutting portion 2 of the diaphragm-specific blade 2 is designed.
Even if c hits the convex portion 1d of the shutter base plate 1 and the aperture lever 4 is prevented from rotating in the closing direction, since the cam is provided in the direction to further close the aperture lever 4, the aperture lever 4 and the straight advance Even if the contact point between the cam pin 4b and the cam portion 6 is deviated due to the finished condition of the individual parts such as the guide 5 or the looseness of the engagement between the cam pin 4b and the cam portion 6, this so-called overcharge ensures that the minimum aperture is reached. The diaphragm lever 4 can be rotated to the opening. Further, even when the cam portion 6 tries to rotate in the closing direction when the aperture lever 4 cannot actually rotate in the closing direction,
Since the portion from the shaft 1c of the diaphragm lever 4 to the cam pin 4b can be elastically deformed and absorbed, there is no functional effect.

Further, if the convex portion 1d of the shutter base plate 1 is the surface to be corrected, the convex portion 1d can be corrected to
Since the change in the aperture shape due to the completion of the diaphragm-specific blades 2 and 3 can be absorbed to form the minimum diaphragm shape as designed, the optical performance can be compensated.

Therefore, the minimum diaphragm aperture can be accurately obtained without using a component for urging the diaphragm blades in the closing direction, so that not only the number of components is reduced, but also the shutter device needs to be enlarged accordingly. Therefore, it is possible to obtain the effect that it does not hinder the miniaturization of the entire camera.

(Second Embodiment) FIG. 3 shows a plan view of a shutter device according to a second embodiment of the present invention.

The same reference numerals are given to those having the same functions as those of the first embodiment.

FIG. 3 shows a state in which the diaphragm-specific blades 2 and 3 form the maximum diaphragm aperture. The diaphragm blade 2 is provided with a contact portion 2d, and the shutter base plate 1 is provided with a stopper portion 1e at a position facing the contact portion 2d when the diaphragm blade 2 forms the maximum diaphragm aperture. The contact portion 2d abuts here.

In the above structure, the diaphragm-specific blades 2 and 3
However, when the minimum diaphragm aperture is gradually opened to the maximum diaphragm aperture, and when the diaphragm diaphragm blades 2 and 3 form the maximum diaphragm aperture, the contact portion 2d of the diaphragm blade 2 is the stopper portion of the shutter base plate 1. Hit 1e. Therefore, the diaphragm lever 4 does not rotate further in the opening direction.

Apart from this, FIG. 4 shows a part of the development of the rectilinear guide 5 on the inner diameter side. As for the locus of the cam portion 6 provided on the rectilinear guide 5, the abutment portion 2d is designed to be the stopper portion 1 by design.
The locus 6d is shifted by ΔL _{2 in the} opening direction from the locus 6c of the cam pin 4b when it hits e.

That is, the abutting portion 2 of the diaphragm-specific blade 2 is designed.
Even if d hits the stopper portion 1e of the shutter base plate 1 and the aperture lever 4 is prevented from rotating in the opening direction, since the cam is provided in the direction to further open the aperture lever 4, the aperture lever 4 and the straight advance Even if the contact point between the cam pin 4b and the cam portion 6 is deviated due to the completion of the individual parts such as the guide 5 or the looseness of the engagement between the cam pin 4b and the cam portion 6, the so-called overcharge amount ensures the maximum throttle. The diaphragm lever 4 can be rotated to the opening. Further, even when the cam portion 6 tries to rotate in the opening direction when the diaphragm lever 4 cannot actually rotate in the closing direction, it can be absorbed by elastically deforming the portion from the shaft 1c of the diaphragm lever 4 to the cam pin 4b. , There is no functional impact.

In the first embodiment described above, it has been described that the minimum diaphragm shape can be accurately obtained by correction if the convex portion 1d of the shutter base plate 1 is used as the correction target surface. Although the maximum aperture shape can be accurately obtained, in general, if the maximum aperture shape is completely retracted from the aperture opening diameter D of the shutter base plate 1, the maximum aperture shape will hardly have an adverse effect on the optical performance.

Therefore, in the case of this embodiment, it is not necessary to mold the stopper portion 1e with high precision.

Therefore, the maximum diaphragm aperture can be reliably obtained without using a component for urging the diaphragm-dedicated blade in the opening direction. Therefore, not only the number of components is reduced, but also the shutter device needs to be enlarged accordingly. Since it is eliminated, there is an effect that it does not hinder the miniaturization of the entire camera.

Reference Example FIG. 5 shows a reference example of the present invention. Although the drawing shows a part of the cross section in the optical axis direction, the diaphragm lever 14 (having the same function as that of the first and second embodiments) arranged on the shutter base plate 1 is a shutter. When arranged on the base plate 1 (shown by a broken line in FIG. 5), the distance between the optical axis L and the tip of the cam pin 14b of the diaphragm lever 14 is configured to be h1.

In this state, the shutter base plate 1 is incorporated in the straight guide 5. However, if the distance between the bottom surface 6e of the cam portion 6 provided on the straight-moving guide 5 and the optical axis L is h2, then h1 ≧ h2 is satisfied, so the diaphragm lever 14 bends in the optical axis direction. The state shown by the solid line in FIG. 5 (so-called overcharge) is achieved.

According to the above construction, the diaphragm lever 14 bent in the optical axis direction always tries to press the cam pin 14b against the cam portion 6 by its elastic force.
Even if 4 falls in the optical axis direction at the time of molding, it can be used as a component except for those having an overcharge of 0 or less, so that the yield is improved and the cost is reduced. Further, since the cam pin 14b and the cam portion 6 are surely brought into contact with each other due to the amount of overcharge, a desired diaphragm opening can be obtained. Furthermore, it is needless to say that the reliability of obtaining the minimum or maximum aperture opening is further improved if the method is performed simultaneously with the first or second embodiment.

That is, by using the diaphragm lever bent in the optical axis direction, not only the desired diaphragm aperture can be surely obtained, but also the yield of the diaphragm lever can be improved, so that the cost can be reduced. The effect of being connected can be obtained.

[0035]

According to the first aspect of the present invention, the driving force for further driving the diaphragm member in the closing direction at the minimum diaphragm opening position acts on the diaphragm lever. It is possible to obtain the minimum aperture without fail and to satisfy the optical performance without requiring a new biasing member, and to contribute to downsizing of the entire camera without increasing the size of the shutter device. it can.

According to the second aspect of the invention, it is possible to absorb the change in the aperture shape due to the manufacturing error of the aperture member and obtain the minimum aperture shape as designed.

According to the third aspect of the invention, the driving force for further driving the diaphragm member in the opening direction at the maximum diaphragm aperture position is provided.
Since it acts on the diaphragm lever , the maximum diaphragm opening can be reliably obtained without being influenced by production errors such as component manufacturing errors, and a shutter device while satisfying optical performance without requiring a new biasing member. It is possible to contribute to the miniaturization of the entire camera without increasing the size of the camera.

[Brief description of drawings]

FIG. 1 is a front view of a shutter device showing a first embodiment of the present invention.

FIG. 2 is a partial development view of an inner diameter of a straight guide of the shutter device of FIG.

FIG. 3 is a front view of a shutter device showing a second embodiment of the present invention.

FIG. 4 is a partial development view of an inner diameter of a rectilinear guide of the shutter device of FIG.

FIG. 5 is a vertical sectional view of a shutter device showing a reference example of the present invention .

FIG. 6 is a front view of a conventional shutter device.

7 is a vertical cross-sectional view of the shutter device of FIG.

8 is a rear view of the shutter device of FIG.

[Explanation of symbols]

1 ... Shutter base plate 1d ... Convex part 1e ... Stopper part 2, 3 ... Blade for exclusive use of diaphragm 1, 14 ... Aperture lever 4b, 14b ... Cam pin 1 ... Straight guide 6 ... Cam section

Claims (3)

(57) [Claims] 1. A plurality of diaphragm members provided on a diaphragm base plate for setting different apertures with respect to an aperture opening diameter, and a diaphragm lever rotatably provided on the diaphragm base plate for opening and closing the plurality of diaphragm members. A cam portion with which the aperture lever engages is formed along the optical axis direction, and a linear guide that controls the rotation of the aperture lever by the cam portion due to movement in the optical axis direction during zooming, A shutter device for cam-driving the aperture lever by moving the linear guide linearly to control opening and closing of the plurality of aperture members, wherein a first contact portion is provided on any one of the plurality of aperture members. And a second contact portion with which the first contact portion abuts is provided on the diaphragm base plate at a position where the plurality of diaphragm members form a minimum diaphragm opening. in a state where the contact portion of the second is in contact with, overcharge shape It said in order to
The locus of the cam portion is defined by the first contact portion and the second contact portion.
In the closing direction rather than the designed cam locus at the time of contact
A shutter device having a trajectory shifted by a predetermined distance . 2. The shutter device according to claim 1, wherein the second contact portion provided on the diaphragm base plate is a correction target portion of the minimum diaphragm aperture. 3. A plurality of diaphragm members provided on a diaphragm base plate for setting different apertures with respect to the aperture opening diameter, and a diaphragm lever rotatably provided on the diaphragm base plate for opening and closing the plurality of diaphragm members. A cam portion with which the aperture lever engages is formed along the optical axis direction, and a linear guide that controls the rotation of the aperture lever by the cam portion due to movement in the optical axis direction during zooming, A shutter device for cam-driving the aperture lever by moving the linear guide linearly to control opening and closing of the plurality of aperture members, wherein a first contact portion is provided on any one of the plurality of aperture members. And a second contact portion with which the first contact portion abuts is provided on the diaphragm base plate at a position where the plurality of diaphragm members form a maximum diaphragm opening. in a state where the contact portion of the second is in contact with, overcharge shape It said in order to
The locus of the cam portion is defined by the first contact portion and the second contact portion.
In the opening direction rather than the designed cam locus at the time of contact
A shutter device having a trajectory shifted by a predetermined distance .