JPH05100286A - Program shutter for variable focus lens - Google Patents

Abstract

PURPOSE:To control exposure with high accuracy both in an ordinary photographing mode and an aperture-priority photograping mode and to automatically control the setting of an F value in the aperture-priority photographing mode by one electromagnetic driving device. CONSTITUTION:In the ordinary photographing mode, the F value of a shutter blade is controlled by a projecting part 15 for controlling an F value in an ordinary mode which is formed in a driving ring member 13 for driving the opening/closing of a shutter blade 2 also used as an aperture. Meanwhile, in the aperture-priority photographing mode, the driving ring member 13 is rotated in reciprocating direction by a stepping motor 18 previous to photographing actions, when a sequence arithmetic means 57 discriminates that a zoom lens is in a wide state and an EV value discrimination means 60 discriminates that an EV value is equal to or above a specified level(EV 12). Then, the motion restricting arm part 31b of the F value setting lever 31 of an aperture-priority F value setting means 30 faces a position where it is engaged with the restricting step part 7c of an aperture opening/closing lever 7, so that the F value is regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable focus lens program shutter provided with a variable focus lens and capable of selectively executing shooting in a normal shooting mode and shooting in an aperture priority shooting mode. is there.

[0002]

2. Description of the Related Art For example, by using a stepping motor, an electromagnetic solenoid or the like to electromagnetically drive a shutter blade that also serves as a diaphragm, an F that matches the subject brightness at that time can be obtained.
A technique for incorporating a shutter configured to obtain a combination of a value and a shutter speed value into a camera equipped with a variable focus lens is disclosed in, for example, Japanese Patent Laid-Open No. 2-242240 and Japanese Patent Laid-Open No. 2-254428. Has already become known.

That is, in Japanese Patent Laid-Open No. 2-242240, a first electromagnetic drive for swinging a movable member 30B (reference numeral in the publication, hereinafter the same) for opening and closing a shutter blade that also serves as a diaphragm in a reciprocating direction. The device (monostable high-speed control solenoid) 30 and the movable member 30 projecting within the swing locus range of the movable member 30B by the first electromagnetic drive device 30.
A second electromagnetic drive device (plunger solenoid) 50 that drives the regulating member 40 that blocks the swinging of B in the forward and backward directions during the movement is provided, and these two electromagnetic drive devices 30 and 50 are controlled. Therefore, the movable member 30B
There is disclosed a technique of realizing three kinds of F-numbers (aperture values) by composing so that it can be forcibly stopped at three positions.

Further, instead of the second electromagnetic drive device 50, by providing a regulating member drive means having three types of stop positions, three or more types of F in combination with the stop position by the first electromagnetic drive device 30 are provided. A technique of realizing a value is disclosed.

On the other hand, Japanese Unexamined Patent Publication No. 2-254428 discloses an actuator 1 for opening and closing the shutter blades 14 and 15 that also serve as apertures via an operating lever 3 (reference numerals in the publication, the same applies hereinafter), and the actuator 1. A regulation cam 18 for forcibly limiting the amount of rotation of the drive pin 2 that is rotated by the control cam 22 and an adjustment cam 22 that can adjust the amount of protrusion of the regulation cam 18 within the range of the rotation trajectory of the drive pin 2 are provided. When the focal length values of the varifocal lenses 26 to 28 are changed by zooming, the engagement position of the regulation cam 18 is changed according to the change of the focal length value, so that the varifocal lens 2
A technique is disclosed in which the F value (aperture value) of 6 to 28 is always set appropriately.

[0006]

However, in the former technique disclosed in Japanese Patent Laid-Open No. 2-242240, it is an essential condition to provide two electromagnetic driving devices 30 and 50 to perform three types of F value control. Therefore, not only the configuration becomes complicated, but also a faster control means (for example, CPU) for driving the two electromagnetic drive devices at different timings.
The need arises to use.

Along with this, it is necessary to secure a space for installing two electromagnetic driving devices in a camera or a lens barrel which is originally narrow, and at the same time, the two electromagnetic driving devices are simultaneously installed. When it is operated, there arises a problem that it requires twice as much electric power as compared with the case of using one electromagnetic drive device.

Further, from the viewpoint of manufacturing, there is a problem that the cost is increased as compared with the case where one electromagnetic drive device is used.

Further, when three or more types of F-number control are performed, it is necessary to provide a regulating member driving means having a more complicated structure instead of one electromagnetic driving device 50. Get serious.

On the other hand, in the latter technique disclosed in Japanese Patent Laid-Open No. 2-254428, the regulating cam 18 (including the adjusting cam 22) which projects the amount of rotation of the rotating drive pin 2 so as to be displaceable within the range of the rotational locus. The cam surface of FIG. 4) limits the movement of the drive pin 2 when the amount of rotation of the drive pin 2 becomes large.
Since it is necessary to secure the momentum of the above, the cam curvature of the regulation cam 18 is inevitably increased, which is apt to occur.

However, if the curvature of the cam surface is set strongly,
If the engagement position between the drive pin 2 and the cam surface is “shifted” even a little, the momentum of the drive pin 2 changes significantly. Therefore, when such a momentum limiting mechanism is used for a shutter that also serves as an aperture. Need to consider this point.

That is, if a large number of F values are continuously set between the maximum F value and the minimum F value in the shutter that also serves as the diaphragm, the amount of rotation of the drive pin 2 naturally increases, so that the restricting cam 18 is provided. The cam curvature of the drive pin 2 becomes strong, and accordingly, at the position where each F value is realized, a change phenomenon of the momentum of the drive pin 2 occurs due to the above-mentioned “shift” of the engagement position between the drive pin 2 and the cam surface. The possibility arises.

In this case, in the shutter that also serves as the diaphragm, even if the amount of change in the momentum of the drive pin 2 that is generated is constant, the degree of influence is significantly different between the small F value region and the large F value region. ..

That is, a small F value (large aperture opening)
Since the aperture opening area at each F value is large in absolute value in the region of, even if the same amount of motion error occurs in the momentum limiting mechanism, the ratio of the area change based on the motion error relative to each aperture opening area is relative. The effect on the photometric accuracy is not so large.

However, in a region of a large F value (small aperture opening), the aperture opening area at each F value is small in absolute quantity, and therefore the ratio of the area change due to the motion error relative to each aperture opening area is relatively large. The larger the effect, the greater the influence on the photometric accuracy.

This poses a serious problem in relation to the photometric accuracy in the aperture priority mode which requires a large F value in order to take a picture using a deep depth of focus.

Therefore, the use of the momentum limiting mechanism as disclosed in Japanese Unexamined Patent Publication No. 2-254428 for a shutter that also serves as a diaphragm adopting the diaphragm priority mode causes a problem in photometric accuracy, which is unsatisfactory. Considered appropriate.

In addition, according to the technique disclosed in Japanese Patent Laid-Open No. 2-254428, it is difficult to perform the above-mentioned F-number control only in the wide-side focal length region and at a specific subject brightness. There is also.

In addition, in a general camera having a shutter in the aperture priority mode, high-speed shutter-speed photographing is performed so as to be able to photograph an object moving at high speed (referred to as "normal photographing mode" in this specification). Since the proposition that it must be made possible also exists separately regardless of the above-mentioned two prior arts, the emergence of a new diaphragm / shutter (program shutter) capable of solving all of these problems. Was wanted.

The present invention has been made in view of the above circumstances. A first object of the present invention is to shoot a subject moving at high speed and to shoot in a telephoto state in which a camera shake phenomenon is likely to occur. It is possible to shoot using the normal shooting mode that can use high-speed shutter speed, and when shooting outdoor group souvenir photos or photos with depth, use the aperture priority shooting mode that provides a deep depth of field. It is possible to shoot with both of the shooting modes with high photometric accuracy, and the F-number setting control in each shooting mode can be controlled by one electromagnetic drive device. It is to provide a new variable focus lens program shutter that can be performed.

A second object of the present invention is to provide a new program shutter for varifocal lens which does not require the camera operator to set the aperture priority photographing mode each time when taking a group memorial photograph or a photograph with depth. To provide.

[0022]

In order to achieve the first object, the invention described in claim 1 is at least a variable focus lens and a focal length for changing the focal length of the variable focus lens. The changing means, the photometric means for measuring the subject brightness, the proper exposure computing means for computing the proper EV value based on the subject luminance information from the photometric means, and the proper EV value computed by the proper exposure computing means. Program of the normal photographing mode for selecting a combination of a plurality of types of F values including the maximum F value and the minimum F value and the shutter speed value, and the F value and the shutter speed value with priority given to the predetermined F value. A program shutter for a variable focus lens, which is provided with a program for the aperture priority shooting mode for selecting the combination of the above, is set so that it can reciprocate between the fully closed position and the fully open position of the aperture. A diaphragm-shutter blade that is,
In order to reciprocally drive the diaphragm / shutter blade between the fully closed position of the diaphragm and the fully opened position of the diaphragm, an initial position and a maximum operating position of the diaphragm are reciprocally rotatable in a blade opening direction and a blade closing direction. And the blade opening / closing member that is always urged in the blade opening direction by the urging force of the diaphragm urging member, the locking position for locking the blade opening / closing member at its initial position, and the locking for the blade opening / closing member. A locking claw member provided so as to be able to reciprocate between a locking release position for releasing and a locking light configured to set the locking position as a permanent position, and the photographic light of the variable focus lens. It is provided rotatably in the forward and reverse directions about an axis, and when itself is in the vicinity of the starting position, redundantly locks the blade opening / closing member together with the locking claw member at its initial position, Forward direction from the starting position To release the locking with respect to the vane opening and closing member when rotated by required controlled variable, when its is rotated in the reverse direction from the position rotated by the required controlled variable,
A drive ring member having a control cam portion having a shape capable of forcibly preventing the rotation operation of the blade opening / closing member at a position capable of realizing a plurality of continuous F values required for the normal shooting mode, and the diaphragm. Prior to the opening / closing operation of the dual-purpose shutter blade, a mode selection unit for selecting one of the normal shooting mode and the aperture priority shooting mode; and, when the aperture priority shooting mode is selected by the mode selection unit, Aperture-priority F for limiting the momentum of the blade opening / closing member in the blade opening direction and setting at least one F value
A value setting means, a forward / reverse rotation type motor that drives the drive ring member to rotate in the forward / reverse direction by a controlled amount, and in any of the shooting modes, the forward / reverse rotation type motor is rotated in the forward direction. And a drive control unit for controlling to rotate in the reverse rotation direction and determining a stop timing and a reverse rotation timing of the forward / reverse rotation type motor based on the appropriate EV value information from the appropriate exposure calculation means. It is characterized by being configured as follows.

In order to achieve the second object, the invention according to claim 2 is a focal length detecting means for detecting whether the varifocal lens is in a short focal length state or a long focal length state. And E for determining whether the proper EV value calculated by the proper exposure calculation means exceeds a predetermined threshold value.
From the V value discriminating means, the detection information from the focal length detecting means that the variable focus lens is in the short focal length state, and the EV value discriminating means that the proper EV value exceeds a predetermined threshold value. The aperture priority mode automatic selecting means for automatically setting the shooting mode to the aperture priority shooting mode based on the discrimination information of 1.

According to a third aspect of the invention, in order to achieve the second object, at least one end of the aperture priority F-number setting means is a fixed end and the other end is a swing end. Further, a switching spring provided so that the swinging end can swing in the reciprocating direction beyond the dead point line, and the dead point by the biasing force of the switching spring that holds the other end of the switching spring. The blade opening / closing member is operated by the operation of the intermediate displacing member provided so as to reciprocate between the two switching positions across the line in a switchback operation and the intermediate displacing member displacing between the two switching positions. Is provided so as to be reciprocally moved between a limit position where the momentum of the blade in the blade opening direction can be limited and a limit release position where the limit is released, and In the mode, the aperture priority F-number setting lever is placed at the restriction release position, and the aperture priority mode automatic selection unit is provided with the aperture-priority F number setting cam portion formed on the drive ring member. The drive ring prior to the rotation of the drive ring member in the normal and reverse directions when the opening / closing operation of the aperture / shutter blade is performed when the aperture priority photographing mode is selected by the mode selection means. By rotating the member in the reverse direction to bring the aperture priority F value setting cam portion into contact with the intermediate displacement member from one direction, the intermediate displacement member is switchbackly displaced in one direction, The aperture priority F value setting lever at the limit release position is moved to the limit position to set the F value in the aperture priority shooting mode. Is obtained is characterized in that the sea urchin configuration.

According to a fourth aspect of the present invention, in order to achieve the second object, when the aperture priority F value setting lever moved to the limit position is used to open / close the aperture / shutter blade. By rotating the drive ring member in the reverse direction prior to rotating the drive ring member in the reverse direction, the aperture priority F value setting cam portion is brought into contact with the intermediate displacement member from one direction, and the engagement operation is performed. By rotating the drive ring member in the forward direction to bring the aperture priority F value setting cam portion into contact with the intermediate displacement member from the other direction, the intermediate displacement member is switched back in the other direction. It is characterized in that it can be returned to the restriction release position by displacing to.

[0026]

The program shutter for a variable focus lens according to the present invention operates as follows.

First, three types of program diagrams are prepared in advance for the variable focus lens program shutter.

The first program diagram is such that, when the varifocal lens is in the wide state, it can be adapted to a subject moving at high speed, and the minimum F value of the varifocal lens at that time (for example, F3. 7) and the maximum F value (for example, F1
3) The program diagram for the normal photographing mode that can realize continuous F-numbers (for example, A ₁ → A ₂ → A in FIG. 11)
₃ ) Set as.

The second program diagram is a predetermined aperture-priority F-number that provides a deep depth of field so that a deep depth of field can be used for shooting when the varifocal lens is in a wide state. (For example, F8) program diagram for aperture priority shooting mode (for example, B → A _{3 in} FIG. 11)
Set as.

In this case, a predetermined aperture priority F is obtained until a shutter speed (for example, 1/60 seconds) is obtained in which the occurrence of the camera shake phenomenon does not have to be considered within the proper EV value range.
Make sure to set the program diagram so that the values can be maintained.

The third program diagram shows that, when the varifocal lens is in the tele state, the minimum F value (for example, F5.6) and the maximum F value (for example, F1) of the varifocal lens at that time are set.
5) is set as a program diagram (for example, FIG. 12) for the normal shooting mode at the time of telephoto that can realize continuous F values.

Furthermore, the operation mode of the shutter mechanism is
Normally (when the camera is started), an operation mode in which exposure control can be performed according to the program diagram for the normal shooting mode and the program diagram for the normal shooting mode at the time of telephoto, and the variable focus lens is in a wide state and the EV is appropriate. When the value is equal to or higher than a predetermined level (for example, EV12), it is divided into an operation mode capable of performing exposure control according to the program diagram for the aperture priority photographing mode.

In the normal shooting mode operation mode and the telephoto normal shooting mode, the normal mode F-number control projection formed on the drive ring member for opening and closing the shutter blades for the diaphragm also serves as the diaphragm shutter. F-number control of the blades is performed. On the other hand, in the operation mode in the aperture-priority shooting mode, the aperture-priority F-number setting means provided in the peripheral portion of the drive ring member controls the F-number of the aperture / shutter blade 2. To configure.

Then, the focal length detecting means detects that the varifocal lens is in the wide state (wide side),
Further, when the EV value determining means determines that the proper EV value at that time is equal to or higher than the predetermined level, the drive ring member is rotated in the reciprocating direction prior to the opening / closing operation of the diaphragm / shutter blade, and the rotation in the reciprocating direction is performed. The operation state (posture) of the aperture priority F-number setting means is switched by operation, and the operation mode of the shutter mechanism section is automatically changed from the operation mode in the normal shooting mode to the operation mode in the aperture priority shooting mode. Yes.

When the variable focus lens is in the tele state, the operation mode of the shutter mechanism section is automatically changed to the operation mode in the telephoto normal photographing mode based on the focal length value information from the focal length detection means. It is designed to switch to.

[0036]

Embodiments will be described in detail below based on embodiments in which the present invention is applied to a program shutter for a zoom lens.

FIG. 1 is a system configuration diagram showing the entire system of one embodiment of a program shutter for a zoom lens of the present invention.

In FIG. 1, the zoom lens camera equipped with the program shutter of the present invention has, for example, a minimum F value of F3.7 in a short focal length state and a minimum F value of F5.6 in a long focal length state. Is designed as a camera having a zoom lens and a zooming means capable of moving the zoom lens from the wide area to the tele area (neither of which is shown).

Reference numeral 1 denotes a shutter mechanism portion which is a main portion of the program shutter of the present invention, and is configured as a so-called built-in shutter which is installed in an intermediate portion in a zoom lens barrel (not shown).

As will be described later, the shutter mechanism section 1 is programmed in a normal photographing mode (for example, A ₁ → A ₂ →
A ₃ ) and an operation mode capable of performing exposure control according to a program diagram for the normal shooting mode at the time of telephoto (for example, FIG. 12), and a zoom lens in a wide state (within a wide range side) and appropriate. The EV value is at a predetermined level (for example,
In the case of EV12) or above, it is configured to have an operation mode capable of performing exposure control according to the program diagram for the aperture priority photographing mode (for example, B → A _{3 in} FIG. 11).

In the operation mode of the normal photographing mode, the F value control during the exposure control is performed by the normal mode F value control projection 15 formed on the drive ring member 13, which will be described later, of the shutter blade 2 that also serves as the diaphragm. When the F value control is performed and the operation mode is the aperture priority shooting mode, the drive ring member 13
The F-value control of the aperture / shutter blade 2 is performed by the aperture-priority F-number setting means 30 provided in the peripheral portion of the above-described structure, and two types of motion limiting means having different systems are used.

Reference numeral 2 denotes a shutter blade that also serves as a diaphragm and reciprocates between the fully closed position and the fully open position of the diaphragm to form a plurality of types of diaphragm apertures (F values). The shutter blade is provided at a fixed portion of the shutter mechanism section 1. It is rotatably supported by the appropriate support shaft 3.

Although only one diaphragm / shutter blade 2 is shown in FIG. 1, a plurality of diaphragm / shutter blades 2 (three in this example) are used similarly to a known shutter of this type. It is configured to partially overlap to form a desired aperture opening.

In the program shutter of the illustrated embodiment, the position shown in FIG. 1 is the full-closed position (also the normal position) of the shutter blade 2 that also serves as the aperture, and from this position in the clockwise direction with the support shaft 3 as the center. The maximum rotated position is the fully open position of the diaphragm / shutter blade 2.

Reference numeral 4 denotes an aperture opening / closing ring which is provided so as to be rotatable in the forward and reverse directions around a photographing optical axis (not shown), and the rear side of the aperture is engaged with the cam groove 2a of the shutter blade 2 that also serves as the aperture. Three aperture pins 5 for pushing and turning the dual-purpose shutter blade 2 are planted, and an aperture opening / closing lever 7 described later is provided on the front side.
And a connecting pin 6 that engages with the fork-shaped groove 7b of the.

Reference numeral 7 denotes an aperture opening / closing lever which is rotatably supported in a reciprocating direction by a support shaft 8 in a fixed portion of the shutter mechanism unit 1. It has a habit of always rotating clockwise by an urging force of an appropriate urging spring 9. Has been granted.

A bending portion 7a as an operating portion is provided at one end of the arm portion of the aperture opening / closing lever 7, and a connecting pin 6 of the aperture opening / closing ring 4 is sandwiched at the other end portion of the arm portion. A fork-shaped groove 7b that engages in a formula, and a limit step at the other arm intermediate portion that engages with a motion limiting arm portion 31b of an aperture priority F value setting lever 31 of an aperture priority F value setting means 30 described later. Each part 7c is formed.

Therefore, the aperture opening / closing lever 7 and the aperture opening / closing ring 4 are connected to each other by the connecting pin 6 and the fork-shaped groove 7.
The blade opening / closing member described in the claims is constructed by interlocking via b.

In the program shutter of the illustrated embodiment, the position shown in FIG. 1 is the initial position of the aperture opening / closing lever 7 (which is also the permanent position), and the support shaft 8 is rotated clockwise from this position to the maximum. The closed position becomes the maximum operating position of the diaphragm.

Reference numeral 10 is a locking claw member which is supported by a support shaft 11 on the fixed portion of the shutter mechanism 1 so as to be capable of reciprocating rotation, and is biased by an appropriate biasing spring 12 so as to always rotate clockwise. ..

The locking claw member 10 has a first locking surface 10 for locking the bent portion 7a of the aperture opening / closing lever 7.
a and a flank face 10 formed so as not to come into contact with the bent portion 7a when the aperture opening / closing lever 7 is rotated clockwise.
b and an arm portion 10c that engages with a lock release pin 17 described later.
And are formed.

In this locking claw member 10, the position shown in FIG. 1 is the locking position, which is the permanent position, and the position rotated from this position about the support shaft 11 in the counterclockwise direction by a predetermined amount or more. Is the unlocked position.

A drive ring member 13 is provided, for example, in an outer region of the aperture opening / closing ring 4 so as to be rotatable in the forward and reverse directions around the photographing optical axis. A normal mode F value control for engaging a gear portion 14 meshing with a small-diameter gear and an aperture opening / closing lever 7 to realize a plurality of continuous F values (for example, F3.7 to F13) required for the normal shooting mode. A protrusion 15 and an aperture priority F value setting cam portion 16 that engages with a bell crank member 36 on the aperture priority F value setting lever 31 described later are provided.

In the program shutter of the illustrated embodiment, the position shown in FIG. 1 is the starting position (which is also the permanent position) of the drive ring member 13, and the counterclockwise direction is the normal rotation direction of the drive ring member 13. ..

Now, the above-mentioned normal mode F value control projection 1
5 is provided with the functional portions described in (a) and (b) below. That is,

(A) When the drive ring member 13 is at its starting position, the bent portion 7a of the aperture opening / closing lever 7 is locked so as to overlap the first locking surface 10a of the locking claw member 10. The fold portion 7a of the iris opening / closing lever 7 is held when the iris opening / closing lever 7 is held at its initial position and the drive ring member 13 is rotated from its starting position in the normal rotation direction (counterclockwise direction) by a required control amount. The second locking surface 15a having a structure capable of releasing the locking with respect to is formed. Also,

(B) Reverse direction (clockwise) from the position where the drive ring member 13 rotates in the forward direction by the required control amount.
When the camera is rotated to the normal position, the bent portion 7a of the aperture opening / closing lever 7 is locked at a position where a plurality of continuous F-numbers (F3.7 to F13 described above) necessary for the normal shooting mode can be realized, and the aperture opening / closing lever is locked. A normal mode F value cam portion 15b having a shape capable of forcibly preventing the clockwise rotation operation of 7 at this F value realization position is formed.

On the other hand, the aperture priority F value setting cam section 16 has
A traveling direction acting surface 16a that cams when the drive ring member 13 rotates in the reverse direction (clockwise direction), and a cam when the drive ring member 13 rotates in the normal direction from the position where the drive ring member 13 has rotated in the reverse direction. Return direction acting surface 16 which acts
b are formed.

Reference numeral 17 denotes an unlocking pin for rotating the locking claw member 10 counterclockwise against the urging force of the urging spring 12, and the drive ring 13 is rotated counterclockwise by a predetermined amount from its starting position. When rotating to, the arm portion 10 of the locking claw member 10
It is planted at a position on the drive ring 13 that can engage with c.

Reference numeral 18 is a forward / reverse rotation type motor, for example, a stepping motor, which drives the drive ring member 13 to rotate in the forward and reverse directions by a controlled amount, and its output shaft has a drive gear 18a.
Is attached.

Reference numeral 19 is a reduction gear means interposed between the drive gear 18a and the gear portion 14 of the drive ring member 13, and is composed of, for example, a two-stage gear having a small reduction ratio, which is composed of a large diameter gear and a small diameter gear. Has been done.

Reference numeral 30 denotes at least one F value (for example, F8) necessary for the aperture priority shooting mode in the normal shooting mode.
Aperture priority F value setting means for realizing
It is composed of main members such as a value setting lever 31, a bell crank member 36, a switching spring 38, and a midpoint spring 40.

Exposure control is performed according to the program diagram for the normal photographing mode (for example, A ₁ → A ₂ → A _{3 in} FIG. 11) and the program diagram for the normal photographing mode during telephoto (for example, FIG. 12). To obtain an operation mode and the zoom lens is in a wide state and the proper EV value is a predetermined level (for example,
In the case of EV12) or higher, there is an operation mode capable of performing exposure control according to the program diagram for the aperture priority shooting mode (for example, B → A _{3 in} FIG. 11). Reference numeral 31 denotes an aperture priority F-number setting lever rotatably supported by a common support shaft 32 in a fixed portion of the shutter mechanism unit 1. Left and right portions are formed as a switching arm portion 31a and a movement limiting arm portion 31b, and an intermediate portion is formed. It is configured to have the first spring pin 33. The diameter of the first spring pin 33 is set to be substantially the same as the diameter of the second spring pin 37 described later.

Reference numerals 34 and 35 denote first and second fixing pins for limiting the rotation range of the aperture priority F value setting lever 31, which are provided at the fixed portion of the shutter mechanism section 1.

In this case, the first fixed pin 34 is used for the aperture priority F when the aperture opening / closing lever 7 realizes a plurality of continuous F values (F3.7 to F13) required for the normal photographing mode.
It is provided at a position where the position of the value setting lever 31 can be set,
The second fixing pin 35 is provided at a position where the position of the aperture priority F value setting lever 31 when the aperture opening / closing lever 7 realizes at least one F value (F8) necessary for the aperture priority shooting mode can be set. I shall.

A bell crank member 36 is rotatably supported on the aperture priority F-number setting lever 31 by a common support shaft 32. One arm portion is formed as an engaging arm portion 36a, and the other arm portion has a first arm portion 36a. It is configured to have two spring pins 37.

In this case, at least the engagement arm portion 36a is
The aperture priority F value setting cam portion 1 of the drive ring member 13 described above.
Within the rotation plane of 6
It shall be provided so that it can be removed.

Reference numeral 38 is a switching spring composed of an appropriate coil spring, one end of which is hooked on a support pin 39 provided on a fixed portion of the shutter mechanism 1, and the other end of which is hooked on the above-mentioned first spring pin 33. Has been.

In this case, the position of the support pin 39 is set such that the line connecting the support pin 39 and the above-mentioned common support shaft 32 becomes the dead point line of the switching spring 38.

Reference numeral 40 is a midpoint spring for setting the position of the bell crank member 36 in the permanent relation with respect to the aperture priority F value setting lever 31, and its head 40a is, as shown in FIG.
The two leg portions 40b and 40c are formed in a ring shape so that the two leg portions 40b and 40c cross each other at an intermediate portion and then have a width substantially equal to the diameters of the first spring pin 33 and the second spring pin 37 and are parallel to each other. It is configured.

In the midpoint spring 40, the head 40a is wound around the common support shaft 32, and the two legs 40b and 40c are sandwiched between the outer peripheral surfaces of the first spring pin 33 and the second spring pin 37, respectively. Common support shaft 3 so that they contact each other
2. It is combined with the first spring pin 33 and the second spring pin 37.

Now, the aperture priority F having such a structure
The value setting means 30 performs the following switchback operation to obtain F3.7 which is a continuous F value in the normal shooting mode.
To a state in which F13 can be realized (state in FIG. 3) and a state in which F8 which is the F value in the aperture priority photographing mode can be realized (FIG. 1)
(Or the state of FIG. 5), and when the camera is started, the F
It is configured in advance so as to be set in a state where 3.7 to F13 can be realized (state in FIG. 3).

[State in Normal Photographing Mode] When the aperture priority F-number setting means 30 is in a state (state of FIG. 3) capable of realizing continuous F-numbers F3.7 to F13 in the normal photographing mode. , The switching arm portion 31a of the aperture priority F value setting lever 31 is in contact with the first fixing pin 34, and the movement limiting arm portion 31b of the aperture priority F value setting lever 31 is the rotation locus of the limiting step portion 7c of the aperture opening / closing lever 7. It is located outside the range.

At this time, the aperture priority F value setting lever 3
The first spring pin 33 on 1 is located at a position outside the dead point line of the switching spring 38 (position in the direction away from the photographing optical axis), and the switching spring 3
The aperture priority F value setting lever 31 is pressed against the first fixing pin 34 by the urging force of the bell crank member 36.
The engagement arm portion 36a of the
The value setting cam portion 16 is set to project into the range of the rotation locus.

In this state, the aperture priority F value setting lever 3
Since the motion limiting arm portion 31b of No. 1 does not contact the limiting step portion 7c of the aperture opening / closing lever 7, the aperture priority F value setting lever 31
Is F, which is the minimum F value in the normal shooting mode in the clockwise direction.
It becomes possible to rotate to a position where 3.7 can be realized.

That is, the aperture priority F-number setting means 30
F3.7 to F1 which are continuous F values in the normal shooting mode
3 will be set in a state (posture) that can be realized.

[Transition from State in Normal Shooting Mode to State in Aperture Priority Shooting Mode] Aperture priority F value setting means 30
However, in the state of FIG. 3, the drive ring member 13 is rotated in the reverse direction (clockwise direction) by an amount necessary for setting the aperture priority shooting mode, and the aperture priority F value setting cam portion 16 is moved to the bell crank member 36. And the bell crank member 36 is rotated counterclockwise by the advancing direction acting surface 16a of the aperture priority F value setting cam portion 16.

At this time, as the bell crank member 36 rotates counterclockwise, the second spring pin 37 on the bell crank member 36 pushes and rotates one leg portion 40b of the midpoint spring 40 in the opening direction. , The other leg 40c that is engaged with the first spring pin 33 moves in the closing direction by the urging force of the midpoint spring 40, and the pressing force rotates the aperture priority F-number setting lever 31 counterclockwise.

However, the other leg portion 40c of the midpoint spring 40
The rotation of the aperture priority F value setting lever 31 due to is up to the position where the first spring pin 33 crosses the dead point line of the switching spring 38, and the first spring pin 33 crosses the dead point line and is located inside thereof. After moving to the position (position near the photographing optical axis), the aperture priority F value setting lever 31 is rotated by the urging force of the switching spring 38 and contacts the second fixing pin 35 as shown in FIG. The second contact pin 35 is kept in contact with the second fixing pin 35 by the urging force of the switching spring 38.

That is, the aperture priority F-number setting means 30
The movement restriction arm portion 31b of the aperture priority F value setting lever 31
Keeps projecting within the range of the rotation locus of the limiting step portion 7c of the aperture opening / closing lever 7.

After that, the drive ring member 13 rotates in the forward direction (counterclockwise direction) and returns to its starting position, and the entire aperture priority F value setting means 30 is in the state shown in FIG. 5 (also in FIG. 1). Will be moved to.

That is, the aperture priority F-number setting means 30
The motion limiting arm portion 31b of the aperture priority F-number setting lever 31 projects into the rotation locus range of the limiting step portion 7c of the aperture opening / closing lever 7, and the continuous F value in the normal shooting mode is F3.7. ~ State in which F13 can be realized (state in Fig. 3)
To a state in which the aperture priority F value F8 can be realized (FIG. 1
The state will shift to the state shown in FIG.

[Returning from Aperture Priority Shooting Mode State to Normal Shooting Mode State] Aperture Priority F Value Setting Means 30
1 is in the state of FIG. 1, the drive ring member 13 is rotated in the reverse direction by an amount necessary for setting the normal shooting mode,
As shown in FIG. 6, the advancing direction acting surface 16 a of the aperture priority F value setting cam portion 16 is connected to the engaging arm portion 3 of the bell crank member 36.
Contact 6a.

Then, by further continuing the rotation, the advancing direction acting surface 16a pushes the engaging arm portion 36a of the bell crank member 36 counterclockwise while the aperture priority F
The value setting cam portion 16 is connected to the engaging arm portion 3 of the bell crank member 36.
6a is moved to the back side, and the rotation of the drive ring member 13 is stopped at the position where the rotation amount necessary for setting the normal photographing mode is obtained.

That is, the aperture priority F value setting means 30
When the drive ring member 13 rotates in the reverse rotation direction in the state of FIG. 1, first, the advancing direction acting surface 16a of the aperture priority F value setting cam portion 16 moves the bell crank member 36 through the engaging arm portion 36a. It is rotated counterclockwise and, as shown in FIG. 7, one leg 40b of the midpoint spring 40 is pushed and rotated in the opening direction via the second spring pin 37.

Then, one leg portion 40b of the midpoint spring 40
However, when it is pushed around in the opening direction, the other leg portion 40c of the midpoint spring 40 causes the aperture priority F through the first spring pin 38.
Attempts to rotate the value setting lever 31 counterclockwise.

However, the aperture priority F-number setting means 30
In the state of FIG. 1 (FIG. 5), the aperture priority F value setting lever 31 is prevented from rotating in the counterclockwise direction by the second fixing pin 35, so that the other leg portion 4 of the midpoint spring 40 is prevented.
The bell crank member 36, which is pressed to 0c, is in a state in which only itself rotates largely in the counterclockwise direction, so that the aperture priority F value setting cam portion 16 is moved to the back side of itself as shown in FIG. Become.

Therefore, the drive ring member 13 can be rotated to a position where the rotation amount required for setting the normal photographing mode can be obtained.

On the other hand, the bell crank member 36 is provided with a switching spring 38 after passing through the aperture priority F value setting cam portion 16.
With the urging force of, the state shown in FIG. 1 (FIG. 5) is restored.

This completes the first half stage of the switching operation from the state in the aperture priority photographing mode to the state in the normal photographing mode, but after this, the latter half stage operation is subsequently performed.

Now, in the latter half of the operation, the aperture priority F value setting cam portion 16 of the drive ring member 13 that has moved to the back side of the bell crank member 36 is moved to the position after completion of the rotation in the reverse direction (for example, FIG. 8). Position) to rotate in the forward direction (counterclockwise direction) in reverse, and the aperture priority F value setting cam unit 1
6 by the return direction acting surface 16b of the bell crank member 36
Is pushed around from the back side of the engaging arm portion 36a, and as shown in FIG. 9, the other leg portion 40c of the midpoint spring 40 is pushed in the opening direction by the second spring pin 37.

When the other leg 40c is pressed in the opening direction in this manner, one leg 40b of the midpoint spring 40 is pressed.
However, the first spring pin 33 is pushed and rotated, and the aperture priority F value setting lever 31 is rotated clockwise against the urging force of the switching spring 38.

At this time, if the first spring pin 33 crosses the dead point line of the switching spring 38 while the aperture priority F-number setting lever 31 is rotating clockwise, the biasing force of the switching spring 38 will be aperture priority. The F-number setting lever 31 works clockwise to bring the aperture-priority F-number setting lever 31 into contact with the first fixing pin 34, and the urging force of the switching spring 38 causes the aperture-priority F-number setting lever 31 to move. Is kept pressed against the first fixing pin 34.

That is, the aperture priority F value setting means 30
The movement restriction arm portion 31b of the aperture priority F value setting lever 31
Is out of the rotation locus range of the limiting step portion 7c of the aperture opening / closing lever 7, and the aperture priority F value of F8 can be realized (from the state of FIGS. 1 and 5) to the continuation of the normal shooting mode. It returns to the state (state of FIG. 3) that can realize F3.7 to F13 which are the F values.

In the illustrated embodiment, the relation between the aperture opening / closing lever 7 and the aperture priority F value setting means 30 is set so as to satisfy such a condition.

As shown in the exploded assembly view of FIG. 10, the constituent members of the shutter mechanism section 1 thus constructed are arranged between the fixed plate 20, the rear plate 21, and the front plate 22 arranged in parallel with each other. Although they are attached and assembled by using screws or the like, the assembling work itself is not directly related to the present invention, and therefore its description is omitted for the sake of simplicity.

By the way, the means for electrically controlling the shutter mechanism 1 including the aperture priority F value setting means 30 is constructed as follows.

Reference numeral 51 is a motor driving means for driving the stepping motor (forward / reverse rotation type motor) 18 in the forward and reverse directions, which is connected to a power feeding circuit 53 including an appropriate DC power source 52 and a general control unit CPU which will be described later. ..

Reference numeral 54 is a photometric means for measuring the subject brightness.
The subject brightness information value can be output to the overall control unit CPU.

Reference numeral 55 denotes a focal length detecting means for detecting whether the zoom lens is in the wide state or the tele state.
The detection information is output to the integrated control unit CPU.

Reference numeral 56 is a normal photographing mode dedicated setting means for always operating the program shutter in the normal photographing mode regardless of the brightness of the subject. When the dedicated setting means 56 is set, the program shutter is set. , A ₁ → A ₂ → A ₃ in FIG. 11 and the program diagram in FIG. 12 are used for exposure.

The general control unit CPU controls the entire program shutter and is configured as a control unit having various function realizing means described below.

Reference numeral 57 is a sequence calculation means for executing the exposure sequence of this program shutter, and when the camera is started (in a steady state) and the normal photographing mode dedicated setting means 56 is operated, the program shutter is operated in the normal photographing mode. And the proper EV value at that time when the zoom lens is in the wide state and a predetermined threshold value (for example, E
In the case of V12) or above, the program shutter can be operated in the aperture priority photographing mode.

Further, the shutter speed is formed based on the proper EV value information from the proper exposure calculation means 59, which will be described later, and the mode selection information from the aperture priority mode automatic selection means 61 or the normal photographing mode dedicated setting means 56. The stepping motor 18 is configured to be able to determine the stop timing and the reverse rotation timing.

Further, when the zoom lens is in the telescopic state, the operation mode of the shutter mechanism section 1 is automatically operated in the telephoto normal photographing mode based on the focal length detection information from the focal length detection means 55. It is configured so that the mode can be switched.

Reference numeral 58 is a storage means for storing the program of the program shutter used in this camera, and stores the following three types of program diagrams.

(1) When the zoom lens is in a wide state, the minimum F value of the zoom lens at that time (for example, F
3.7) and the maximum F value (for example, F13), the program diagram for the normal photographing mode (for example, A ₁ → A ₂ → A _{3 in} FIG. 11) that can realize continuous F values, for example, EV
It operates over a range of 5 to EV17.

(2) When the zoom lens is in a wide state, a predetermined aperture-priority F value (for example, a large aperture depth) that provides a deep depth of field so that a deep depth of field can be used for shooting.
F8) is a program diagram for the aperture priority shooting mode (for example, B → A _{3 in} FIG. 11), and when the proper EV value is equal to or larger than a predetermined threshold value (for example, EV12), for example, the range of EV12 to EV17. Works over.

In this program diagram, a predetermined aperture priority F value is maintained until a shutter speed (for example, 1/60 seconds) is obtained in which it is not necessary to consider the occurrence of a camera shake phenomenon within the range of an appropriate EV value. Is set to be possible.

(3) When the zoom lens is in the tele state, the minimum F value of the zoom lens at that time (for example, F
5.6) and a maximum F value (for example, F15), a program diagram (for example, FIG. 12) for a normal telephoto mode capable of realizing continuous F values, for example, EV6 to EV17.
Operates over a range of.

In the present invention, the wide state refers to a focal length region in which the camera shake phenomenon is unlikely to occur, and conversely, the tele state refers to a focal length region in which the camera shake phenomenon easily occurs.

Reference numeral 59 is a proper exposure calculation means for calculating a proper EV value based on the subject brightness information from the photometry means 54.

Reference numeral 60 is an EV value discriminating means for discriminating whether or not the proper EV value calculated by the proper exposure calculating means 59 exceeds a predetermined threshold value (for example, EV12).

Reference numeral 61 is an aperture priority mode automatic selecting means for automatically setting the exposure mode of the program shutter to the aperture priority shooting mode when the proper EV value exceeds this threshold value. It is configured so that it can be set based on the detection information from the focal length detection means 55 that there is and the discrimination information from the EV value discrimination means 60 that the proper EV value exceeds the threshold value.

Reference numeral 62 denotes drive control means for controlling the drive of the stepping motor 18, whichever exposure mode is used.
First, in order to set the state of the aperture priority F-number setting means 30, the drive ring member 13 is rotated in the reverse rotation direction, and subsequently the motor drive means 51 is controlled so as to be rotated in the forward rotation direction, and then the shutter blades that also serve as the diaphragm. In order to open and close 2, the drive ring member 13 is controlled to rotate in the forward rotation direction and subsequently to rotate in the reverse rotation direction.

Next, the operation or action of the program shutter thus configured will be described with reference to the flow charts shown in FIGS. 13 and 14. [I] First, when the zoom lens is wide,
Moreover, the appropriate EV value at that time is a predetermined threshold value (for example, E
The operation or action in the case of V12) or above will be described.

When the power of the camera is turned on and the exposure sequence is started by pressing the shutter release member halfway, for example, the photometric means 54 first detects the subject brightness and comprehensively controls the subject brightness information at that time. Since it is output to the central processing unit CPU, the proper exposure calculation means 5 in the general control unit CPU
At 9, the appropriate EV value at that time is calculated based on the subject brightness information [step: S1].

Following this photometric operation, the focal length detecting means 5
5 operates to output the focal length information to the overall control unit CPU. The overall control unit CPU determines whether the zoom lens is in the wide state or the tele state based on the focal length information [step: S2].

In this case, if the zoom lens is in the wide state, step S2 is branched to YES, and subsequently,
The EV value determination means 60 determines whether or not the proper EV value calculated by the proper exposure calculation means 59 exceeds a predetermined threshold value (for example, EV12) [step: S3].

At this time, if the proper EV value calculated by the proper exposure calculation means 59 is EV14, the sequence calculation means 57 causes the aperture priority mode automatic selection means 61.
Is set to the operating state, and the program shutter is shifted from the normal photographing mode to the aperture priority photographing mode.

That is, according to the program diagram indicated by B → A ₃ in FIG. 11 and according to the processing steps of the flow chart shown in FIG. 14, the state is changed to the exposure execution [step: S4].

Now, in step S11 of the flow chart of FIG. 14, when the sequence calculation means 57 determines that the aperture priority mode automatic selection means 61 should be set in the operating state, the sequence calculation means 57 causes the drive control means 62 to operate. Is instructed to control the rotation of the drive ring member 13 according to the aperture priority photographing mode.

Therefore, the drive control means 62, via the motor drive means 51, first reverses the stepping motor (STM) 18 by an amount enough to obtain the attitude of the aperture priority F value setting means 30 in the aperture priority shooting mode. It is controlled so as to rotate to [step: S12].

Therefore, the stepping motor 18 causes the drive ring member 13 to rotate in the reverse direction in the operation sequence described in detail in the section [Transition from the state in the normal photographing mode to the state in the aperture priority photographing mode]. (Clockwise)
For example, the drive ring member 13 is rotated by, for example, 6 pulses, and then similarly rotated by 6 pulses in the forward direction to rotate the drive ring member 13 in the forward direction (counterclockwise direction) toward its starting position [Step: S13-S19].

As a result, the aperture priority F-number setting means 30
The state in the normal shooting mode (state in FIG. 3) shifts to the state in the aperture priority shooting mode (states in FIGS. 1 and 5).

More specifically, the above-described operation will be described in more detail. The movement limiting arm portion 31b of the aperture priority F-number setting lever 31 projects into the rotation locus range of the limiting step portion 7c of the aperture opening / closing lever 7, and the shutter that also serves as an aperture. The opening movement amount of the blade 2 is shifted to a state in which the opening movement amount is limited by the opening movement amount required to obtain the aperture corresponding to the aperture priority F value (F8) [step: S12].

At this time, the sequence calculating means 57 monitors whether or not the operation for 6 pulses is accurately performed during the shifting operation of the aperture priority F value setting means 30 [step: S13].

Then, when it is confirmed that the drive ring member 13 is rotated accurately, the sequence calculation means 57
Is the stepping motor 18 with respect to the drive control means 62.
Command to stop. That is, at this point,
The aperture-priority F-number setting means 30 shifts to the state in the aperture-priority shooting mode [step: S14].

After that, the sequence calculation means 57 commands the drive control means 62 to reversely rotate the stepping motor 18 in the forward rotation direction (counterclockwise direction), and finally drives the drive ring member 13. Control to rotate in the forward direction toward the starting position [Step: S
17].

Further, the sequence calculating means 57 monitors whether or not the rotating operation of the drive ring member 13 is accurately performed, and after confirming that the drive ring member 13 has returned to the starting position,
The drive control means 62 is instructed to stop the stepping motor 18 [steps: S18 and S1.
9].

When the drive ring member 13 returns to the starting position in this way, the sequence calculation means 57 continues to realize the program diagram B → A ₃ shown in FIG. 11 for the drive control means 62. A command is issued to rotate the stepping motor 18 in the forward direction by the required rotation amount [step: S20].

Therefore, the drive control means 62 rotates the drive ring member 13 in the forward rotation direction from the position shown in FIG. 1 via the motor drive means 51.

At this time, the normal mode F value control projection 15 on the drive ring member 13 moves relative to the bent portion 7a of the aperture opening / closing lever 7 as the drive ring member 13 rotates, and as shown in FIG. As shown, aperture opening / closing lever 7
The bent portion 7a is removed from the second locking surface 15a of the normal mode F value control protrusion 15 and is brought into contact with the first locking surface 10a of the locking claw member 10.

In this case, the bent portion 7a is in the normal mode F.
From the second locking surface 15a of the value control projection 15 to the locking claw member 1
The aperture opening / closing lever 7 rotates clockwise in accordance with the movement to the first locking surface 10a of 0. However, since the rotation amount at this time is extremely small, the aperture / shutter blade 2 is fully closed. The state will be retained as it is.

The bent portion 7a of the aperture opening / closing lever 7
Is engaged with the first locking surface 10 a of the locking claw member 10, the locking release pin 17 on the drive ring member 13 is locked by the locking claw member 1.
Move to the position where it engages with the 0 arm part 10c
0c is rotated counterclockwise against the urging force of the urging spring 12, and as the drive ring member 13 rotates in the forward direction thereafter, the locking claw member 10 is moved relative to the bent portion 7a of the aperture opening / closing lever 7. It will rotate counterclockwise from the locked position to the unlocked position.

Therefore, the double stoppers of the second engaging surface 15a and the first engaging surface 10a with respect to the bent portion 7a of the aperture opening / closing lever 7 are disengaged, and the bent portion 7a of the aperture opening / closing lever 7 is changed to the dotted line and the solid line in FIG. As shown by, the state is such that the first locking surface 10a of the locking claw member 10 is disengaged from one end and begins to fall into the clearance surface 10b of the locking claw member 10.

As a result, the aperture opening / closing lever 7 has its limit step portion 7c set to the aperture priority F by the urging force of the urging spring 9.
The aperture priority F value setting lever 31 of the value setting means 30 is rotated clockwise until it comes into contact with the movement restricting arm portion 31b.

At this time, since the rotational force of the aperture opening / closing lever 7 is transmitted to the aperture opening / closing ring 4 via the fork-shaped groove 7b of the aperture opening / closing lever 7 and the connecting pin 6, the aperture opening / closing ring 4 moves in the opening direction (counterclockwise). It will rotate clockwise).

When the aperture opening / closing ring 4 rotates in the counterclockwise direction in this manner, the aperture pin 5 is accordingly moved by the cam groove 2
By moving in a predetermined direction in a, the shutter blade 2 also used as the diaphragm is opened around the support shaft 3 to the angle set by the cam action of the cam groove 2a. The opening amount (opening angle) is the aperture opening / closing lever 7 until the limiting step portion 7c of the aperture priority F value setting means 30 comes into contact with the movement limiting arm portion 31b of the aperture priority F value setting lever 31.
Is determined by the rotation amount (the rotation amount that realizes F8) [step: S21].

At this time, the bent portion 7a of the aperture opening / closing lever 7 is held at the spatial position as shown by the solid line in FIG.

In this way, the shutter blade 2 that also serves as the diaphragm
However, when it is opened to a position where F8 is realized, the sequence calculation means 57 holds the aperture / shutter blade 2 at that position for a predetermined time, and then, via the motor drive means 51, starts the drive ring member 13 in the reverse rotation starting position. Control to rotate up to [Step: S22 and S23].

Therefore, the drive ring member 13 rotates in the reverse direction, but during the rotation, the diaphragm in which the normal mode F value cam portion 15b of the normal mode F value control projection 15 is held in the spatial position. Bending part 7 of the open / close lever 7
In contact with a, the diaphragm opening / closing lever 7 is pushed counterclockwise by the curved surface action (cam action) of the cam portion, and finally the urging force of the urging spring 9 is resisted as shown in FIG. Then, the bent portion 7a is pushed up onto the second locking surface 15a of the normal mode F value control protrusion portion 15.

At this time, the drive ring member 13
The locking claw member 10 rotates clockwise by the urging force of the urging spring 12 so as to follow the rotation in the reverse rotation direction of, and the first locking surface 10a is located below the bent portion 7a of the aperture opening / closing lever 7. Move to the position and move the aperture opening / closing lever 7 to the control projection 1.
5 returns to the position (position shown in FIG. 1) in which the second locking surface 15a cooperates with the second locking surface 15a for overlapping locking.

When the aperture opening / closing lever 7 rotates counterclockwise in this manner, the aperture opening / closing ring 4, the aperture pin 5, and the cam groove 2a move in the closing direction to close the aperture / shutter blade 2. First, the bent portion 7a of the aperture opening / closing lever 7 is moved to the first locking surface 10 of the locking claw member 10 by the second locking surface 15a of the normal mode F value control protrusion 15.
It stops at the position (aperture fully closed position) pushed up to a, and the aperture / shutter blade 2 is returned to the fully closed state [step: S24].

Therefore, when the aperture priority photographing mode is set, as shown in the timing chart of FIG. 18, the bent portion 7a of the aperture opening / closing lever 7 has the first locking surface 10a of the locking claw member 10. Of the aperture opening 10b from the one end of the aperture opening 10b to the flank 10b, and the limiting step portion 7c of the aperture opening / closing lever 7 causes the aperture priority F value setting means 30 to set the aperture priority F value. After abutting against the movement restricting arm portion 31b of the value setting lever 31, when the drive ring member 13 is rotated in the reverse direction and pushed up onto the second locking surface 15a of the normal mode F value control projection portion 15, the closing ends. It is time.

Therefore, in the illustrated embodiment, the rotation speed of the stepping motor 18, the rotation completion position of the forward rotation, the timing at which the rotation is started in the reverse direction from this rotation completion position, and the aperture opening / closing lever 7 are provided. In consideration of the urging force of the urging spring 9 and the like, it is configured to control the opening start time and the closing end time of the aperture / shutter blade 2 in the aperture priority shooting mode, and the aperture priority is thereby set. The shutter speed in the photographing mode is set.

In this case, in the explanation in the item [I], the proper E
Since the V value is EV14, the shutter speed at this time is 1 / according to the program diagram of B → A ₃ in FIG.
It will be set to 250 seconds.

On the other hand, the drive ring member 13 continues to rotate toward the starting position even after the opening / closing operation of the aperture / shutter blade 2 is completed. At this time, the sequence calculation means 57 is used.
(Or, an appropriate monitoring means) monitors the rotational movement of the drive ring member 13, confirms that the drive ring member 13 has returned to the starting position, and stops the stepping motor 18. [Steps: S25 and S26].

This completes a series of program shutter operations related to the aperture priority photographing mode when the proper EV value is EV14.

That is, up to about EV15, exposure control is performed according to the diagram of A ₃ in FIG. 11, which is the same diagram as the program diagram in the normal photographing mode, and the limit of the camera shake phenomenon. Possible shutter speeds (eg 1
The program shutter operation of performing the exposure control according to the diagram of B of FIG. 11 narrowed to the aperture priority F value is completed up to about EV12 (/ 60 seconds). [II] Next, the operation or action when the zoom lens is in the wide state and the appropriate EV value at that time is equal to or less than the predetermined threshold will be described.

For example, the appropriate EV value at that time is EV10.
If so, the exposure sequence at that time proceeds as follows.

First, "Step: From S1 to S3"
The process proceeds in the same manner as in the case of EV14 described above.

However, the proper EV value at this time is EV10.
Therefore, the sequence calculation means 57 keeps the program shutter in the normal photographing mode, and A ₁ →
The exposure is controlled so as to follow the program diagram indicated by A ₂ → A ₃ [step: S5].

That is, the sequence calculation means 57 instructs the drive control means 62 regardless of whether the orientation of the aperture priority F-number setting means 30 is the orientation in the normal photography mode or the orientation in the aperture priority photography mode. Then, the drive ring member 13 is instructed to rotate in the reverse direction to a position where the posture in the normal photographing mode is obtained (10 pulses in this example) [step: S15].

For this reason, the drive control means 62 rotationally drives the stepping motor 18 in the reverse direction via the motor drive means 51 to return from the state in the [aperture priority photographing mode] to the state in the normal photographing mode described above. ] The drive ring member 13 is controlled so as to rotate in the reverse rotation direction (clockwise direction) according to the operation sequence described in detail in the above section.

Therefore, the drive ring member 13 rotates in the reverse direction, and first, the movement direction acting surface 16a of the aperture priority F value setting cam portion 16 causes the aperture priority F value setting means 30 to move to the second fixing pin 35. To rotate to the posture (the state shown in FIGS. 1 and 5) in the aperture priority shooting mode until it comes into contact with.
Keeps rotating in the reverse direction until the movement limit arm portion 31b of the aperture priority F value setting lever 31 is pushed up and reaches a predetermined position on the back side thereof.

At this time, the sequence calculation means 57 monitors whether or not the rotation of the drive ring member 13 is accurately performed in a predetermined manner, as in the case of the EV 14 described above [step: S16].

When it is confirmed that the drive ring member 13 is rotated accurately, the sequence calculation means 57
Is similar to the case of the EV 14 described above, the drive control means 62.
To the stepping motor 18 [step: S14].

When it is confirmed that the aperture priority F value setting cam portion 16 of the drive ring member 13 has stopped at a predetermined position on the back side of the movement restricting arm portion 31b of the aperture priority F value setting lever 31, the sequence calculation means 57. Subsequently instructs the drive control means 62 to rotate the drive ring member 13 in the normal direction [step: S17].

Therefore, the drive ring member 13 rotates toward its starting position, but the return direction acting surface 16 of the aperture priority F value setting cam portion 16 is in the middle of the rotation.
b is the motion limiting arm portion 31b of the aperture priority F value setting lever 31
The aperture priority F value setting means 30 is pushed clockwise until it comes into contact with the first fixing pin 34, and the aperture priority F value setting means 30 is again in the posture in the normal photographing mode (FIG. 3).
State).

That is, the movement limiting arm portion 31b of the aperture priority F value setting lever 31 is limited to the limiting step portion 7c of the aperture opening / closing lever 7.
The state becomes out of the range of the rotation locus of No. 2, and the aperture priority F-number setting means 30 shifts to a posture in which the aperture / shutter blade 2 can be opened to its maximum opening (F3.7).

At this time, the sequence calculating means 57 monitors whether or not the rotating operation of the drive ring member 13 toward the starting position is accurately performed, as in the case of the EV 14 described above, and further, the drive ring member. After confirming that 13 has returned to the starting position, the drive control means 62 is instructed to stop the stepping motor 18 [steps: S18 and S19].

When the drive ring member 13 returns to the starting position in this way, the sequence calculation means 57 continues to realize the program diagram A ₁ → A ₂ → A ₃ shown in FIG. 11 for the drive control means 62. To do so, a command is issued to rotate the stepping motor 18 in the forward direction [step: S20].

Therefore, the drive control means 62 causes the drive ring member 13 to rotate in the forward rotation direction from the starting position via the motor drive means 51, and the locking claw member 10 moves the diaphragm opening / closing lever 7 as in the case of the EV 14. It is rotated counterclockwise from the locking position to the locking releasing position with respect to the bent portion 7a.

As a result, the double stoppers of the second locking surface 15a and the first locking surface 10a with respect to the bent portion 7a of the aperture opening / closing lever 7 are released, and the bent portion 7a of the aperture opening / closing lever 7 is locked by the locking claw member 10. A state in which it can fall from one end of the first locking surface 10a toward the flank surface 10b (FIG. 16).
To the state indicated by the dotted line and the solid line.

At this time, since the aperture priority F value setting means 30 is held in the posture in the normal photographing mode, the aperture opening / closing lever 7 is moved from the initial position to the aperture maximum operating position by the urging force of the urging spring 9. A state in which it can be rotated to (a position that achieves F3.7), that is, the aperture opening / closing lever 7
Fork-shaped groove 7b, connecting pin 6, diaphragm opening / closing ring 4
The shutter blade 2 that also serves as the diaphragm can be opened to the maximum opening via the diaphragm pin 5 and the cam groove 2a.

By the way, when the program shutter is set to the normal photographing mode, the drive ring member continues after the sequence calculating means 57 rotates the locking claw member 10 from the locking position to the locking release position. 13 is rotated in the forward rotation direction, and further, the drive ring member 13 is rapidly stopped at a predetermined position (time point), and is controlled so as to be immediately rotated in the reverse rotation direction in reverse.

Therefore, the drive ring member 13 is rotated in the reverse direction from the predetermined stop position. During the rotation, as shown in FIG. 19, the normal mode F value control projection 15 has the normal mode F value. The value cam portion 15b moves into the rotation locus range of the bending portion 7a of the aperture opening / closing lever 7, engages with the bending portion 7a, and locks the aperture opening / closing lever 7 at this position.

In this case, in the illustrated embodiment, the engagement positions of both of them at this time are preconfigured so as to realize the program diagram of A ₁ → A ₂ → A ₃ shown in FIG. Therefore, when the proper EV value is EV10, the minimum F value (F3.7) on the normal mode F value cam portion 15b is obtained.
Therefore, the portion corresponding to F is engaged with the bent portion 7a of the aperture opening / closing lever 7, and therefore the aperture / shutter blade 2 is once moved to F3.7 by the rotation operation of the aperture opening / closing lever 7.
After being opened to the position of the opening corresponding to, the opening is held at F3.7 at the engagement position on the normal mode F value cam portion 15b [step: S21].

Then, the drive ring member 1 is kept in this state.
After stopping 3 for a predetermined time, the sequence calculation means 57
Issues a command to the drive control means 62 to rotate the drive ring member 13 in the reverse direction again.

Therefore, the drive ring member 13 rotates from the position where the bent portion 7a of the aperture opening / closing lever 7 is locked toward the starting position. During the rotation, the normal mode F value control protrusion The normal mode F-number cam portion 15b of the portion 15 uses its curved surface action to push the aperture opening / closing lever 7 held at the engagement position of F3.7 in the counterclockwise direction, which is different from the case of the EV14 described above. Similarly, the bending portion 7a is moved to the normal mode F against the urging force of the urging spring 9.
The value control protrusion 15 is pushed up onto the second locking surface 15a (see FIG. 17).

At this time, as in the case of the EV 14 described above, the locking claw member 10 is rotated clockwise by the urging force of the urging spring 12 to return to the position shown in FIG. The blade 2 is returned to the fully closed position by this series of operations [steps: S22 to S24].
Equivalent to].

Therefore, when the program shutter is set in the normal photographing mode, as shown in the timing chart of FIG. 20, the bent portion 7a of the aperture opening / closing lever 7 is provided with the flank 10b of the locking claw member 10. The time point when it starts to fall into the portion is the time point when the aperture / shutter blade 2 starts to open, and the bent portion 7a of the aperture opening / closing lever 7 has the normal mode F value cam portion 15 of the normal mode F value control projection portion 15.
After being locked at b, the second locking surface 1 of the normal mode F value control protrusion 15 is generated by the reverse rotation of the drive ring member 13.
The time point when it is pushed up to 5a is the time point when the closing is completed.

Therefore, in the illustrated embodiment, the rotation speed of the stepping motor 18, the rotation completion position of the forward rotation,
Timing of starting rotation in the reverse direction from the rotation completion position. The time when the diaphragm opening / closing lever 7 is locked by the normal mode F value cam portion 15b of the normal mode F value control protrusion 15 and the diaphragm opening / closing lever. In consideration of the urging force of the urging spring 9 applied to the shutter 7, the opening and closing times of the aperture / shutter blade 2 in the normal photographing mode are controlled, and by this, The shutter speed in the normal shooting mode is set.

In this case, in the description in the section [II], the proper E
Since the V value is EV10, the shutter speed at this time is set to 1/60 seconds according to the program diagram of A ₁ → A ₂ → A ₃ in FIG.

The sequence calculation means 57 (or
Appropriate monitoring means), as in the case of the EV14 described above,
The rotation operation of the drive ring member 13 is monitored toward the starting position, and it is confirmed that the drive ring member 13 has returned to the starting position and the stepping motor 18 is stopped [Step:
S25 and S26].

This completes a series of shutter operations in the normal photographing mode when the proper EV value is EV10. [III] The operation or action when the zoom lens is in the telephoto state will be described.

When the zoom lens is in the tele state,
Since the camera shake phenomenon is likely to occur, it is desirable to set the normal shooting mode in which the high speed shutter speed can be used.

Therefore, in the illustrated embodiment, when the zoom lens is in the telephoto state, the zoom lens is operated according to the normal photographing mode, that is, according to the program diagram shown in FIG. 12, regardless of the proper EV value. is there.

Therefore, when the zoom lens is in the tele state, the general control section CPU automatically sets the operation mode of the shutter mechanism section 1 to the tele mode based on the focal length detection information from the focal length detecting means 55. The operation mode is switched to the normal photographing mode, and subsequently, the shutter mechanism section 1 is controlled and operated in the same operation order as the operation order of the above-mentioned item [II].

For example, the appropriate EV value at that time is EV14.
In this case, the normal mode F value cam portion 15b of the normal mode F value control protrusion 15 causes the aperture opening / closing lever 7 to move to F8 and F5.
The bent portion 7a is locked at an intermediate position with respect to 6, and the sequence calculation means 57 causes 1/250 second and 1
The drive ring member 13 is rotationally driven and controlled so that a shutter time of / 500 seconds can be obtained.

If the proper EV value at that time is EV10, the normal mode F value control protrusion 15 has the normal mode F value.
The value cam portion 15b locks the folding opening / closing lever 7 at the position of F5.6, and the sequence calculation means 57 rotationally drives the drive ring member 13 so that a shutter time of 1/30 second is obtained. Control.

Since the above description overlaps with the description of the section [II], the detailed description is omitted for the purpose of avoiding complexity.

If it is desired to always shoot in the normal shooting mode, the normal shooting mode dedicated setting means 56 is operated to set the program shutter in a state in which it operates according to the program diagram in the normal shooting mode. And

Although one embodiment has been described above, the present invention is not limited to this, and various modifications can be made without departing from the scope of the invention.

For example, in the illustrated embodiment, the zoom lens is described as an example, but the present invention, for example, changes the focal length by providing an additional lens for switching the focal length so that it can be inserted into and removed from the photographing optical path. The present invention can be applied to all variable focus lenses including a taking lens configured to do so.

Further, for example, in the illustrated embodiment, the aperture priority F value setting means 30 is operated and controlled by using the aperture priority F value setting cam portion 16 of the drive ring member 13, so that the continuous F in the normal photographing mode is used. The state of the aperture priority shooting mode that realizes the aperture priority F value of F8 from the state where the values of F3.7 to F13 can be achieved (the state of FIG. 3) (FIGS. 1 and 5)
The state is changed from the state in the aperture priority shooting mode to the state in the normal shooting mode. However, by manually controlling the aperture priority F value setting lever 31, the normal shooting is performed. It is also possible to switch between the mode and the aperture priority shooting mode.

In this case, it is necessary to switch between these two states in conjunction with the shooting mode selection operation (switching operation), or to install a dedicated manual operation member at an appropriate location on the camera surface.

Further, in the illustrated embodiment, the range of the aperture priority photographing mode is up to the proper EV value (EV12) which is F8 and at which the shutter speed (for example, 1/60 seconds) at which the camera shake phenomenon is not considered to occur is obtained. However, if circumstances permit, the program shutter can be configured to operate in the aperture priority shooting mode even when the appropriate EV value is less than EV12.

[0190]

As described above, according to the present invention, a high-speed shutter speed can be usually used in the case of photographing a subject moving at high speed and in the telephoto state in which camera shake is likely to occur. In addition to being able to shoot using the shooting mode, you can also use the aperture priority shooting mode that provides a deep depth of field for outdoor group commemorative photos and deep photos. For a new variable focus lens that can selectively execute both shooting modes with high photometric accuracy and that can control F value setting in each shooting mode with a single electromagnetic drive device. A program shutter can be provided.

In this case, compared with the conventional program shutter, the opening / closing operation of the diaphragm / shutter blade can be speeded up, and the driving is performed in the diaphragm priority photographing mode in which the accuracy of the diaphragm opening is required. Since the opening operation of the diaphragm / shutter blade is stopped while the entire system is moving in the opening direction, there is an effect that the bound when the diaphragm / shutter blade is stopped can be reduced.

Further, since the entire drive system can be arranged in the peripheral area of the photographing optical path, there is also an advantage that the installation space of the shutter mechanism section can be reduced.

On the other hand, according to the present invention, it is possible to provide a variable focus lens program shutter which does not require the camera operator to reset the aperture priority photographing mode each time when a group commemorative photograph or a photograph with depth is photographed. Can be done.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an entire system according to an embodiment in which the present invention is applied to a program shutter for a zoom lens, in which a drive ring member is located at its starting position, and an aperture priority F value setting means is an aperture. The case where the priority F value F8 can be realized is shown.

FIG. 2 is an enlarged plan view showing a configuration of a midpoint spring used in the program shutter of FIG.

FIG. 3 is a partial state diagram showing a state in which the aperture priority F-number setting means used in the present invention is in a state capable of realizing F13 which is the minimum F-number in the normal shooting mode.

FIG. 4 is a partial state diagram showing a stage in the middle of transition of the aperture-priority F-number setting means from the state in the normal shooting mode to the state in the aperture-priority shooting mode.

FIG. 5 is a partial state diagram showing a state in which the aperture-priority F-number setting means is in a state capable of realizing F8 which is the F-number in the aperture-priority shooting mode.

FIG. 6 is a partial state diagram showing a state where the aperture-priority F-number setting means is in the process of returning from the state in the aperture-priority shooting mode to the state in the normal shooting mode.

FIG. 7 is a partial state diagram showing a state in which the aperture priority F-number setting means is returning from the state in the aperture priority shooting mode to the state in the normal shooting mode.

FIG. 8 is a partial state diagram showing a state further advanced from the state shown in FIG.

9 is a partial state diagram showing a state further advanced from the state shown in FIG.

10 is an exploded view of the shutter mechanism section of the program shutter shown in FIG.

FIG. 11 is a program diagram of the program shutter when the zoom lens is in a wide state, showing A ₁ → A ₂ → A ₃
The diagram indicated by indicates the diagram when the program shutter is set to the normal photographing mode, and the diagram indicated by B → A ₃ indicates the diagram when the program shutter is set to the aperture priority photographing mode. Show.

FIG. 12 is a program diagram of the program shutter when the zoom lens is in the tele state.

FIG. 13 is a flowchart for automatically setting a shooting mode in the program shutter of FIG.

FIG. 14 is a flowchart showing the operation of the program shutter of FIG. 1 more specifically.

FIG. 15 is an operation explanatory diagram for explaining a situation in which the shutter mechanism unit is locked at the initial position when the program shutter of FIG. 1 is set to the aperture priority shooting mode.

FIG. 16 is an operation explanatory view for explaining an operation state at a stage when the shutter mechanism section is unlocked and the photographing operation is started.

FIG. 17 is an operation explanatory view showing a closing operation state of the shutter mechanism section.

FIG. 18 is a timing chart when the program shutter of FIG. 1 is set to the aperture priority shooting mode.

FIG. 19 is an operation explanatory diagram for explaining a partial operation state of the shutter mechanism section when the program shutter in FIG. 1 is set to a normal shooting mode.

20 is a timing chart when the program shutter of FIG. 1 is set to a normal shooting mode.

[Explanation of symbols]

 1 Shutter mechanism 2 Shutter blades that also serve as apertures 2a Cam groove 3 Support shaft 4 Aperture opening / closing ring 5 Aperture pin 6 Connecting pin 7 Aperture opening / closing lever 7a Bending part (action part) 7b Fork-shaped groove 7c Limiting step 8 Support shaft 9 Energizing Spring 10 Locking claw member 10a First locking surface 10b Relief surface 10c Arm part 11 Support shaft 12 Energizing spring 13 Drive ring member 14 Gear part 15 Normal mode F value control protrusion 15a Second locking surface 15b Normal mode F Value cam part 16 Aperture priority F value setting cam part 17 Lock release pin 18 Stepping motor 18a Driving gear 19 Reduction gear means 20 Fixed plate 21 Rear plate 22 Front plate 30 Aperture priority F value setting means 31 Aperture priority F value setting lever 31a Switching arm portion 31b Motion limiting arm portion 32 Common support shaft 33 First spring pin 34/35 First and second fixation 36 Bell crank member 36a Engagement arm 37 Second spring pin 38 Switching spring 39 Support pin 40 Midpoint spring 40a Head 40b / 40c Leg 51 Motor drive means 52 DC power supply 53 Power supply circuit 54 Photometric means 55 Focal distance detection Means 56 Dedicated setting means for normal shooting mode CPU General control unit 57 Sequence calculation means 58 Storage means 59 Proper exposure calculation means 60 EV value determination means 61 Aperture priority mode automatic selection means 62 Drive control means

Claims (4)

[Claims] 1. At least a varifocal lens, a focal length changing means for changing the focal length of the varifocal lens, a photometric means for measuring the subject brightness, and a subject brightness information from the photometric means. A combination of appropriate exposure calculation means for calculating an appropriate EV value, and a plurality of types of F values including a maximum F value and a minimum F value and a shutter speed value based on the appropriate EV value calculated by the appropriate exposure calculation means. In a program shutter for a variable focus lens, the program shutter for a variable focus lens is provided with a program for a normal shooting mode for selecting A shutter blade that also serves as a diaphragm is provided so as to be capable of reciprocating between a fully closed position and a fully opened position of the diaphragm, and the shutter blade that also serves as the diaphragm is fully closed. In order to reciprocate between the shutter and the fully open position of the diaphragm, the diaphragm is provided so as to be reciprocally rotatable between the initial position and the maximum operating position of the diaphragm in the blade opening direction and the blade closing direction, and the diaphragm biasing member is attached. Between the blade opening / closing member that is constantly urged in the blade opening direction by the force, and between the locking position that locks the blade opening / closing member at its initial position and the locking release position that unlocks the blade opening / closing member. A locking claw member which is provided so as to be capable of reciprocating movement and which is configured so that the locking position is a permanent position, and is rotatable in forward and reverse directions about the photographing optical axis of the variable focus lens. Is provided at the start position, and redundantly locks the blade opening / closing member in its initial position together with the locking claw member when it is near the starting position, and controls itself from the starting position in the forward rotation direction. When the blade rotates by the amount The blade is opened and closed at a position where a plurality of continuous F-numbers required for the normal shooting mode can be realized when the member is unlocked and the device rotates in the reverse direction from the position rotated by the required control amount. A drive ring member including a control cam portion having a shape capable of forcibly preventing the rotation operation of the member, and one of the normal shooting mode and the aperture priority shooting mode prior to the opening / closing operation of the aperture / shutter blade. And a mode selection means for selecting whether or not the aperture priority photographing mode is selected by the mode selection means, and the momentum in the blade opening direction of the blade opening / closing member is limited to set the at least one type of F value. Aperture priority F value setting means, a forward / reverse rotation type motor that drives the drive ring member to rotate in a forward or reverse direction by a controlled amount, and in any of the shooting modes, The forward / reverse rotation motor is controlled to rotate in the forward rotation direction and then to rotate in the reverse rotation direction, and based on the proper EV value information from the proper exposure calculation means, the stop timing of the forward / reverse rotation motor and A program shutter for a variable focus lens, comprising: a drive control unit that determines a reverse rotation timing. 2. A focal length detecting means for detecting whether the variable focus lens is in a short focal length state or a long focal length state, and a proper E calculated by the proper exposure calculating means.
The EV value discriminating means for discriminating whether or not the V value exceeds a predetermined threshold, the detection information from the focal length detecting means that the variable focus lens is in the short focal length state, and the proper EV value are Aperture priority mode automatic selection means for automatically setting the shooting mode to the aperture priority shooting mode based on the discrimination information from the EV value discrimination means that the predetermined threshold value is exceeded. The program shutter for a variable focus lens according to claim 1, which is configured. 3. The aperture priority F-number setting means includes at least one end that is a fixed end and the other end that is a swing end, and the swing end is swung in a reciprocating direction beyond a dead point line. And a switching spring that is provided so that the other end of the switching spring is held, and the two switching positions that sandwich the dead point line by the biasing force of the switching spring are reciprocally displaced in a switchback operation. And a limit position where the momentum of the blade opening / closing member in the blade opening direction can be limited by the operation of the intermediate displacement member provided so as to move between the two switching positions, and the limitation is released. Aperture-priority F value which is provided so as to be reciprocally moved to and from the limit release position, and which is placed in the limit release position in the normal shooting mode. And a setting lever, and the aperture priority mode automatic selection means is configured as a means having an aperture priority F value setting cam portion formed on the drive ring member. When the mode is selected, the aperture-priority F value is obtained by the rotation operation of the drive ring member in the reverse direction prior to the rotation of the drive ring member in the forward / reverse direction when the opening / closing operation of the aperture / shutter blade is performed. By engaging the setting cam portion with the intermediate displacing member from one direction, the intermediate displacing member is displaced in one direction in a switchback operation, and the aperture priority F-number setting lever in the restriction release position is moved to the above-mentioned position. The variable focus lens according to claim 2, wherein the variable focus lens is configured to be moved to a limit position to set the F number in the aperture priority shooting mode. Program shutter's. 4. The aperture priority F moved to the limit position
When the value setting lever is rotated in the reverse direction of the drive ring member prior to the rotation of the drive ring member in the forward / reverse direction when the opening / closing operation of the aperture / shutter blade is performed, the aperture priority F value setting cam portion is moved to the one position. From one direction to the intermediate displacement member, and the rotation operation of the drive ring member in the forward rotation direction following this engagement operation causes the aperture priority F value setting cam portion to engage with the intermediate displacement member from another direction. The program shutter according to claim 3, wherein the intermediate displacement member is configured to be displaced in the other direction in a switchback operation to be returned to the restriction release position by being brought into contact with each other. ..