JP3392211B2 - Camera shutter device and one-way rotation locking mechanism with cam action - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter device for a camera using a shutter blade that also serves as a diaphragm blade, and a one-way rotation locking mechanism with a cam action which can be suitably used for this shutter device.

[0002]

2. Description of the Related Art In a camera shutter device used for a conventional automatic exposure control means using a shutter blade that also serves as an aperture blade, a set of shutter blade opening / closing means is installed on the optical axis of a photographing, and before exposure. The shutter blade is positioned at the closed position to keep the photographing light in a blocked state, and at the time of exposure, the shutter blade is opened toward the position of the proper diaphragm aperture that can realize the proper EV value at each time. In general, the shutter blades are closed toward the closing position at a predetermined timing determined by the shutter speed value at that time.

In such a camera shutter device, the time required for a series of reciprocal movements of one set of shutter blades comes to its own limit, so that it is impossible to obtain a high-speed shutter time value above a certain speed. There were problems or drawbacks.

Therefore, as a method for solving such problems or drawbacks, a technique has already been provided for obtaining a high-speed shutter time value by using two sets of shutter blade means.

This technique is essentially such that two sets of shutter blade means that can be opened and closed independently are installed in advance in the front-rear direction on the photographing optical axis, and one shutter blade means opens the triangular aperture. In the waveform formation or in the trapezoidal opening waveform, at least the shutter opening operation at the shutter time forming is performed, and the closing operation of the other shutter blade is responsible for at least the shutter closing operation at the shutter time forming, As one example thereof, a technique of "camera shutter device" disclosed in Japanese Patent Laid-Open No. 3-89331 is known.

The shutter device of this camera has a first sector and a second sector that can be opened and closed independently, the first sector shares the shutter opening operation, and the second sector has a large opening size. The setting and the shutter closing operation are shared. Therefore, at the time of release, the second sector is opened so as to obtain a desired exposure while the first sector is closed and shields light. Then, in synchronization with the release operation, the first sector is opened, the second sector is exposed through the opening, and the second sector is closed at a predetermined timing to end the exposure, which is the shutter speed. This realizes a high shutter speed.

By the way, in order to embody such a technology as an actual camera shutter device, various technical and manufacturing problems must be overcome. Is a big problem.

For example, in the case of providing two sets of shutter blade means that can be opened and closed independently of each other, first, the mechanism or structure of each shutter blade means tends to be complicated in nature. One of the big problems is how to solve the problem.

Furthermore, a method of correlating the relationship between the opening / closing operation of the shutter blade in one shutter blade means and the opening / closing operation of the shutter blade in the other shutter blade means by a mechanical or mechanical means (mechanical interlocking method) ), The interlocking mechanism for that purpose is naturally required, and the structure of this interlocking mechanism tends to be complicated, but it is difficult to decide how to solve these matters. Is a big problem.

Further, in a camera that is extremely highly demanded to be compact, there is a problem in installation space as to how to incorporate these mechanisms in an originally narrow space.

On the other hand, the relationship between the opening and closing operations of the shutter blades in the two sets of shutter blade means is described in, for example, Japanese Patent Laid-Open No. 3-89331
In the case of adopting the method of relating by electric control means as in the disclosed technique of Japanese Patent Publication, an electric control circuit therefor and an electric quantity-mechanical quantity conversion means such as a plurality of electromagnetic magnets (electromagnetic solenoids) are used. Of course, the necessity is a big problem.

Moreover, the method of relating the opening / closing operations of the shutter blades of the two sets of shutter blade means by the electric control means causes a serious problem in terms of performance or exposure accuracy. This will be described below by taking the technique disclosed in JP-A-3-89331 as an example.

The technique disclosed in Japanese Patent Laid-Open No. 3-89331 is
Although it is provided in a state in which it is applied to an automatic focusing camera, a portion related to the automatic exposure control means will be described.

In the camera shutter device according to the disclosed technique, when the photometry / distance measurement switch is pressed halfway, the arithmetic circuit calculates automatic distance measurement data and photometry data at that time,
Further, the electromagnet control circuit is configured to control the first sector electromagnet and the second sector electromagnet based on the photometric data at this time.

Then, by controlling the electromagnets for the first and second sectors, first, the first sector (corresponding to the second group shutter blade of the present invention) is held in the closed position and the second sector is operated. A sector (corresponding to the first group shutter blade of the present invention) is adjusted from its closed position to the aperture opening position (setting F in FIGS. 10 and 11) adapted to the photometric data at that time.
Value).

According to the technique disclosed in Japanese Patent Laid-Open No. 3-89331, the photographing optical system is displaced to a target position suitable for the automatic distance measurement data in this state, but until the displacement operation of the photographing optical system at this time is completed. , Ratchet locking mechanism is used to lock the second sector in its aperture position.

When the displacement operation of the photographing optical system is completed, the electromagnet control circuit controls the first sector electromagnet,
The first sector is opened from the closed position to the fully open position to start exposure.

Now, when the first sector is opened in a predetermined manner, the electromagnet control circuit controls the electromagnet for the second sector to control the second sector after a lapse of a predetermined time to satisfy the proper exposure that matches the photometric data at that time. Is closed from the aperture opening position at that time, and at this time, the exposure started from the opening operation of the first sector is ended. After that, the camera shutter device is returned to the initial state at a predetermined timing.

[0019]

However, like the technique disclosed in Japanese Patent Laid-Open No. 3-89331, the opening start time of the first sector in charge of the shutter opening operation at the time of exposure and the shutter closing at the time of exposure. When the closing operation start time of the second sector in charge of the operation is controlled by electromagnet control by the electromagnet control circuit, the first sector in charge of the shutter opening operation is also in charge of the shutter close operation. There is also a big problem that the second sector side has a cause that significantly deteriorates the exposure accuracy.

That is, on the side of the first sector, if there is a change in the opening timing or the opening speed (rising) of the first sector, for example, between manufactured cameras, the change in FIG.
As shown in 0, it causes a performance defect that immediately appears as an exposure accuracy error.

On the other hand, on the side of the second sector, when the second sector performs the closing operation, the closing operation is started from the aperture opening position suitable for the photometric data at that time.
Due to the reason of the opening / closing mechanism, the closing operation speed of the second sector in the area where the closing operation is started is inevitably slow.
As shown in FIG. 1, this causes a flat portion in the so-called closing motion curve, which causes a performance defect that the exposure accuracy and the shutter speed are deteriorated.

Moreover, in the technique disclosed in the above-mentioned Japanese Patent Laid-Open No. 3-89331, since the first sector and the second sector are separately controlled to operate, at least two electric quantities- There is also a disadvantage in terms of manufacturing cost and installation space that a mechanical quantity conversion means (specifically, an electromagnet means) is required.

Therefore, at present, there is a strong demand for the emergence of an improved product capable of advantageously solving these various problems.

The present invention has been made in view of the above circumstances, and a first object thereof is (i) an opening / closing operation of a shutter blade that also serves as a diaphragm blade and a shutter closing operation which is in charge of a shutter opening operation at the time of exposure. By mechanically (mechanically) correlating the opening / closing operation of the shutter blade that also functions as the diaphragm blade with the opening / closing operation, it is possible to stabilize the exposure area regardless of whether the waveform is a triangular opening waveform or a trapezoidal opening waveform. It is possible to maintain good accuracy, and (ii) speed up the closing operation speed in the region where the shutter blade that also functions as the shutter closing operation starts closing, regardless of whether it has a triangular opening waveform or a trapezoidal opening waveform. By doing so, it is possible to prevent a flat portion from being generated in the closing motion curve, and (iii) structural, installation space,
It is an object of the present invention to provide a camera shutter device capable of improving various problems in terms of manufacturing cost in an advantageous manner as compared with the conventional camera shutter device of this type.

A second purpose thereof is, for example, a diaphragm / shutter that responds to the opening operation of one of the shutter blades that also serves as the diaphragm blade when mechanically relating to forming a proper shutter time in forming a triangular aperture waveform. One-way rotation locking mechanism such as ratchet pawl locking means used when setting the closing start timing of the blades to a predetermined timing, that is, a member rotated in the forward and reverse directions about a predetermined rotation axis. For example, the reverse rotation start timing when rotating in the reverse direction from the position after the normal rotation is changed by a mechanical cam action. To provide a mechanism.

[0026]

In order to achieve the first object, the invention according to claim 1 comprises a photometric means for photometrically measuring the subject brightness at each moment and outputting photometric data, and an opening / closing operation. A first group shutter blade which can also be used as an aperture blade,
The first group of shutter blades provided as a separate shutter blade, and a second group shutter blade diaphragm blades combined capable of performing opening and closing operations, provided as a member that can move in forward and reverse directions, the first from the initial position An opening operation of the first group shutter blade is performed by an operation in one direction, an opening operation of the second group shutter blade is performed by an operation in the other direction, and at least a closing operation of the first group shutter blade is started,
Further, the closing operation of the second group shutter blade is started again by the operation in the same direction as the first one direction, and the initial position is set.
A drive member you return to location, the time of shooting, the to perform the opening operation until the first group blade open position either from its closed state position to the first group shutter blade, the opening operation of the first group of shutter blades After the start of the, the second group shutter blade is caused to perform an opening operation from the closed state position to any one of the second group blade open positions, and the second group shutter blade is moved from the closed state position to the above-described one. The first group shutter blade at the time point during the process of performing the opening operation toward the second group blade opening position or after the end of the opening operation toward the second group blade opening position. To the second group shutter blade at a time point after the first group blade opening is started to be closed and the first group shutter blade is substantially returned to the closed position. Second group blade As it can carry out the closing operation from the can position the one direction the driving member from the initial position
From the one direction to the other direction, and the other direction
Drive again in the one direction to return to the initial position.
Comprising a shutter blade opening and closing control means for controlling driving of the so that, by closing operation of the operation as the first group of shutter blades open in the second group shutter blade, or at triangular openings corrugating
It is characterized in that configured so as to form a time at least from time to time of the proper shutter speed adapted to the photometric data by the moment of the photometric means during the trapezoidal opening corrugation.

Further, in order to achieve the above first object better, the invention according to claim 2 is characterized in that the opening is performed at any one of the first group blade opening positions of the first group shutter blades. A plurality of preset first group blade over-opening positions are set beyond respective proper aperture opening positions suitable for subject brightness at each time including a position capable of realizing the aperture opening, and the second group shutter is also provided. In any one of the second group blade opening positions of the blades, a plurality of preset positions exceeding respective proper diaphragm opening positions suitable for subject brightness at each time including a position capable of realizing the open diaphragm opening The second group blade excessive open position is set, and the opening operation is performed from the closed state position toward the second group blade excessive open position related to the second group blade open position at each time. First The group shutter blade and the first group shutter blade in the middle of performing the closing operation from the first group blade over-open position to the closed state position related to the first group blade opening position at each time, the mutual operation The position of the movement crossing point that intersects in the process of performing the above-mentioned operation is set to the opening operation start time when the second group shutter blade opens from the closed state position, and the first group blade excess of the first group shutter blade at that time. It is configured to be set as a position that depends on the time series interval between the opening position and the closing operation start time when closing,
Further, by setting a time-series interval between these two operation start points as a plurality of interval values adapted to the photometric data at each time, the movement of the second group shutter blade and the first group shutter blade The position of the crossing point is configured so as to substantially coincide with the position of the aperture level at which the respective proper aperture apertures adapted to the photometric data at each time are obtained. The present invention is characterized in that it is configured so as to be able to form a proper aperture opening at that time including the open aperture opening and a proper shutter time at that time, which are suitable for the photometric data at any time.

In order to achieve the above first object,
According to a third aspect of the present invention, the first group blade opening position of the first group shutter blade is set in advance as a position that can realize the open aperture opening, or a position of an opening level exceeding this position. And the second group blade opening position of the second group shutter blades,
A front stage open position set at a position of an opening level substantially the same as the first group blade open position of the first group shutter blades;
When the second group shutter blade is opened to the front stage open position, the second group shutter blade is configured so that it can be set as a two stage open position including a preset rear stage open position at a position of an opening level exceeding the front stage open position. In addition, the first group shutter blades already opened to the first group blade opening position are provided with the respective delay times set in advance so as to realize a trapezoidal aperture waveform suitable for the photometric data at each time. When the first group shutter blade is opened to the first group blade opening position and the second group shutter blade is opened to the front stage opening position,
When the respective delay times substantially elapse, the second group shutter blades are opened from the front stage opening position to the rear stage opening position, and the opening operation at this time starts the closing operation of the first group shutter blades. The second group shutter blade has an opening operation when opening from the closed state position to the front stage opening position,
The shutter opening operation is performed at the time of forming a trapezoidal aperture waveform suitable for the photometric data at each time, and the first group shutter blade is open at the first group blade opening position or the aperture opening provided in the camera. In addition, a proper aperture opening is formed at the time of forming a trapezoidal aperture waveform that is suitable for the photometric data at each time, and the first group shutter blade is set to the first aperture after substantially elapse of each delay time.
The shutter closing operation at the time of forming the trapezoidal opening waveform is configured to have a closing operation at the time of closing from the group blade opening position to the closed state position, whereby the photometry at each time at the time of forming the trapezoidal opening waveform is performed. The present invention is characterized in that the open diaphragm aperture and the appropriate shutter speed at that time can be formed in conformity with the data.

In order to achieve the above first object,
According to a fourth aspect of the present invention, one electric motor capable of rotating in the forward and reverse directions is provided, and the driving member can be driven by utilizing the rotational driving force of the electric motor. It is a thing.

In order to achieve the above first object,
The invention described in claim 5 is characterized in that the driving member is constituted by a single member.

In order to achieve the above first object,
According to a sixth aspect of the present invention, the drive member is configured as a rotary drive member that rotates in the forward and reverse directions, and is integrated by the rotary drive member only when the rotary drive member rotates in the forward direction. When the rotary drive member is forcibly rotated in the same direction and the rotary drive member is rotated in the opposite direction, the interlocking with the rotary drive member is released, and the forced rotation causes the first
A driven side rotating member that can open the group shutter blade from the closed position to any one of the first group blade opening positions is provided, and the rotation drive member is integrated with the driven side rotating member, When the first group shutter blade is rotated in the positive direction by each rotation amount corresponding to each rotation amount that can be opened from the closed state position to each first group blade opening position related to the photometric data at each time, the driven side rotation is performed. A one-way rotation locking mechanism is provided so that the moving member can be engaged and disengaged in stages at respective positions after the normal rotation at this time. A locked structure that can be locked in a stepwise manner by a stop mechanism is provided on the driven-side rotation member side, and the driven-side rotation member according to one locking step by the one-way rotation locking mechanism Unit rotation angle,
The stepwise unit rotation angle of the rotation drive member in the positive direction is set to the same angle or an integer multiple thereof, and by setting in this way, an appropriate aperture opening at each time is formed. At this time, it is configured so as to prevent occurrence of a half-tooth shift phenomenon between the one-way rotation locking mechanism and the locked structure of the driven-side rotation member. Is.

In order to achieve the above second object,
According to a seventh aspect of the present invention, there is provided a rotating member having a ratchet tooth row in the outer peripheral region, and a ratchet pawl member that engages with the ratchet tooth row of the rotating member so that the ratchet tooth row can be detachably engaged. In the one-way rotation locking mechanism having, the outer peripheral region of the rotating member is provided, for example, from the rotating shaft of the rotating member according to the rotation angle of the rotating member from a preset reference position. In order to change the distance from a small distance to a large distance, or from a large distance to a small distance, sequentially move away from a reference arc surface that has been virtually set in advance according to a predetermined rate of change. A virtual cam surface having a different shape is set, the ratchet tooth row is formed along the virtual cam surface, and the ratchet pawl is formed according to the rotation angle of the rotation member from the reference position. Movement position of the member The rotation member is configured to be changed, and the rotation member is changed by the amount of change in the movement position or movement posture of the ratchet pawl member based on the cam action of the virtual cam surface according to the rotation angle of the rotation member. For example, the reverse rotation start timing when rotating in the reverse direction from the position after the normal rotation is changed can be changed.

[0033]

In the camera shutter device configured as described above, when the exposure operation (exposure operation with the triangular aperture waveform) is performed using the aperture opening smaller than the open aperture opening, first, the shutter is closed during exposure. The first group shutter blade, which is in charge of the operation, is moved in the forward and reverse directions by the forward and reverse rotation drive force of the electric motor, and the forward movement of the drive member causes the brightness of the subject to change from the closed position to the subject brightness in advance. It is opened to the first group blade opening position (first group blade excessive opening position) set at a position beyond the appropriate aperture opening corresponding to the photometric data, and that position is obtained by using mechanical (mechanical) means. Hold on.

When the opening of the shutter blades of the first lens group is completed to the desired position, the second blade in charge of the shutter opening operation at the time of exposure is performed.
By moving the group shutter blades in the opposite direction of the drive member,
The shutter is opened from the closed state position to the preset second group blade opening position, and exposure is started with the photographing light that has passed through the already opened first group shutter blades.

Then, at a time point after the opening operation of the second group shutter blade is started, the first group shutter blade is closed from the first group blade opening position by the subsequent movement of the driving member in the opposite direction. Control is performed so that the first group shutter blade that has started the closing operation and the second group shutter blade that is in the process of opening cross each other during each operation.

At this time, the aperture level position at the intersection of the first group shutter blade and the second group shutter blade can be made to coincide with the position of the proper aperture opening corresponding to the photometric data relating to the subject brightness at that time. The opening start timing of the second group shutter blades and the closing start timing of the first group shutter blades are set using a mechanical time difference setting means.

Then, at a time point after the first group shutter blade returns to the substantially closed position and the predetermined exposure is completed, the second group shutter blade is closed from the second group blade open position to the closed state position. Then, the state of the camera shutter device is returned to the initial state.

On the other hand, when the exposure operation is performed using the open aperture opening (exposure operation with the trapezoidal aperture waveform), the first group shutter blade is set to the preset aperture opening position from the closed position. The blade is opened to the first group blade opening position and held at that position.

When the first group shutter blade has finished opening to the desired position, the second group shutter blade is opened from its closed position to the second group blade over-opening position related to the preset aperture stop opening. In this case, the second group shutter blade is controlled so as to be held at that position for a delay time required to obtain a proper shutter time in combination with the open diaphragm aperture.

When the required delay time elapses, the second group shutter blade is opened from the second group blade excessive opening position to a preset opening position, and the second group shutter blade is opened at this time. Using the operation, the first group shutter blade is closed from the first group blade opening position related to the open aperture opening to the closed state position, and the predetermined exposure is finished.

In the exposure operation with this trapezoidal aperture waveform, the first
The exposure is performed without crossing the group shutter blade and the second group shutter blade during each operation.

Further, in the one-way rotation locking mechanism with the cam action configured as described above, the ratchet tooth row provided in the outer peripheral region of the rotation member is provided to the rotation member from the preset reference position. According to the turning angle, for example, a reference set in advance is set so that the distance from the turning shaft of the turning member changes from a small distance to a large distance or from a large distance to a small distance. The ratchet tooth row of the rotating member is formed on the virtual cam surface having a shape that gradually moves away from the arc surface in accordance with a predetermined change rate, according to the rotating angle of the rotating member from the reference position. It is possible to change the movement position or movement posture of the ratchet pawl member that locks.

Then, depending on the amount of change in the movement position or movement posture of the ratchet pawl member based on the cam action of the virtual cam surface according to the rotation angle of the rotation member, the rotation member is moved from the position after the forward rotation, for example. The reverse rotation start timing when rotating in the reverse direction can be changed.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure and operation of an example of a camera shutter device of the present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is an exploded perspective view showing the structure of an embodiment of a camera shutter device according to the present invention, and FIG.
It is a rear view which shows the back surface structure when the exploded perspective view of FIG. 1 is seen from the right side. In the following description, the term "field side (or front side)" means the left direction in FIGS. 1 and 2, and the term "film side (or back side)" refers to FIG. It means the right direction in FIG.

In FIGS. 1 and 2, reference numeral 1 denotes a camera shutter device (hereinafter, simply referred to as “shutter device”) disposed on a photographing optical axis (hereinafter, simply referred to as “optical axis”) O of a camera (not shown). ), And is fixed to the fixing portion of the holding barrel of the photographing optical system (not shown) by an appropriate method.

Further, in the central area of the substrate 1, as shown in FIGS.
An aperture 1a for determining the opening of the photographic optical system shown in FIG. 1 (hereinafter referred to as "aperture aperture Sa") is provided, and an aperture ring 30 described later is rotatably held around the aperture 1a. Large diameter cylindrical part 1b
And a small-diameter cylindrical portion 1c capable of rotatably holding a drive ring 40 described later.

Reference numeral 10 designates a second group shutter blade 2 which will be described later at the time of photographing so that the function of forming an appropriate aperture opening at the time of photographing and the closing operation of the shutter function can be taken charge of.
First group shutter blade means (hereinafter, referred to as “first group blade means”) that performs the opening operation before the first and second shutter blades 22 and performs the closing operation before the closing operation of the second group shutter blades 21 and 22.
That is).

In the illustrated embodiment, the first group blade means 10 is a pair of diaphragm blades which can be opened and closed in opposite directions and also serve as a pair of first group shutter blades (hereinafter abbreviated as first group blades) 1.
1 and 12, and a first group blade drive lever 15 for simultaneously opening and closing the first group blades 11 and 12 are configured as blade means.

In this case, the first group blades 11 and 12 are, as shown in FIGS. 6 and 8, in the field side region of the space portion sandwiched between the substrate 1 and the later-described blade group restraining plate 4. From the respective closed positions, through the first group pinhole position and the aperture opening Sa, to the first group blade maximum over-open position S1 '(see FIG. 8) so that it can be opened and closed, for example, on the side surface of the field of the substrate 1. It is configured so as to be rotatably supported by each of the implanted pivots 13 and 14, respectively.

Further, each pivot 1 of the first group blades 11 and 12
A pair of first group blade cam grooves 11a, which are fitted simultaneously with the first group blade driving pins 17, at positions near 3 and 14, respectively.
12a is also formed, but regarding the cam shape of the first group blade cam grooves 11a, 12a,
It will be explained again in the section of the diaphragm setting cam groove 31 of the diaphragm ring 30.

In the illustrated embodiment, the first group blade means 1
0 is configured to use two blade members,
It is also possible to configure as a means that uses one blade member or three or more blade members. Regarding the maximum excessive opening position S1 'of the first group blade described above, the exposure calculation circuit 6 described later is used.
It will be explained again in the section 5 for explaining the configuration.

By the way, the first group blade drive lever 15 is
It is pivotally supported by a pivot 16 planted on the film side surface of the substrate 1 so as to be swingable (rotatable). The first group blade drive pin 17 is provided, and the intermediate side transmission pin 18 that can be precisely fitted into the aperture setting cam groove 31 of the aperture ring 30 described later is further provided on the side surface of the film at the tip end portion. .

The initial position of the first group blade drive lever 15 is set at the position when the first group blade drive pin 17 comes into contact with one inner end surface 2a of the first limiting arc groove 2 described later. Further, the maximum swing position is configured to be set, for example, at a position when the first group blade drive pin 17 contacts the other inner end surface 2b of the first restricted arc groove 2.

In the illustrated embodiment, the first group blade drive pin 17 and the intermediate transmission pin 18 are formed as an integrated pin member, but both are formed as separate pin members implanted at different positions. It is also possible to configure, and the initial position and the maximum swing position of the first group blade drive lever 15 are set on the inner end surfaces of both the first restricted circular arc groove 2 and the first corresponding circular arc groove 5. Alternatively, the inner end surface of the first corresponding circular arc groove 5 may be set.

As a result, in the first group blade means 10,
When the group blade driving lever 15 rotates counterclockwise around the pivot 16 from its initial position, the first group blade driving pin 17 is almost fitted in the first group blade cam grooves 11a and 12a at the same time. The first group blades 11, 12 are displaced in the radial direction, and at the maximum, the first group blades 11, 12 are moved from their respective closed positions through the cam action of the respective first group blade cam grooves 11a, 12a. When the first group blade drive lever 15 is rotated clockwise from the maximum swing position, the first group blades 11, 12 are opened to the maximum excessive opening position S1 '.
At the maximum, the first group blade maximum excess opening position S1 '
Will act to close from the to the closed position.

The opening / closing operation of the first group blades 11 and 12 will be described again in the section of the structure of the exposure calculation circuit 65 described later.

On the other hand, reference numeral 20 denotes the opening operation after the first group blades 11 and 12 are opened so that the opening operation of the shutter function and the function of forming a proper aperture opening at the time of photographing can be taken charge of. It is a second group shutter blade means (hereinafter, referred to as "second group blade means") that starts and closes after the first group blades 11 and 12 are substantially closed.

As in the case of the first group blade means 10, the second group blade means 20 has a pair of diaphragm blades which can be opened and closed in opposite directions in the illustrated embodiment (hereinafter, referred to as a second group shutter blade). "Abbreviated as" second group blade ") 21 and 22,
The second group blades 21 and 22 are configured as blade means including a second group blade drive lever 25 for simultaneously opening and closing.

In this case, the second group blades 21 and 22 are closed in their respective closed positions as shown in FIGS. 6 and 8 in the film side region of the space portion sandwiched between the substrate 1 and the blade group restraining plate 4. To the second group pinhole position and aperture opening Sa
So that it can be opened and closed to the second group blade maximum over-opening position S2 '(see FIG. 8) via, for example, each pivot shaft 23, 24 planted on the side of the field of the substrate 1 respectively. It is configured to be pivotally supported.

Further, each pivot 2 of the second group blades 21, 22
A pair of second group blade cam grooves 21a, which are fitted simultaneously with the second group blade driving pins 28, at positions near 3 and 24, respectively.
22a is also formed, but regarding the cam shape of the second group blade cam grooves 21a, 22a,
The second group blade drive lever 25 will be described again.

As will be described later, the second group blades 21, 22 are closed until the first group blades 11, 12 open from the closed position to the maximum first group blade maximum excessive opening position S1 '. It is configured to remain held in position.

In the illustrated embodiment, the first group blade means 1
Similar to the case of 0, the second group blade means 20 is configured to use two blade members, but it may be configured to use one blade member or three or more blade members. . Further, the maximum excessive opening position S2 of the second group blade described above
′ 'Will be explained again later in the section for explaining the configuration of the exposure calculation circuit 65.

By the way, the second group blade drive lever 25 is
For example, it is swingably (rotatably) pivotally supported by a pivot 26 that is planted on the film side surface of the substrate 1, and is always clockwise (blade closing direction) by the urging force of an appropriate urging spring 27.
It is configured to be rotated to.

Further, a first timing cam surface 25a capable of contacting a first timing pin 42 described later is provided at the tip of one arm of the second group blade driving lever 25,
In addition, a pair of second group blades 2 is attached to the tip of the other arm.
It is configured to have a second group blade drive pin 28 that is precisely fitted into the first and second second group blade cam grooves 21a and 22a.

The initial position of the second group blade drive lever 25 is set at the position when the second group blade drive pin 28 comes into contact with one inner end surface 3a of the second restricted arc groove 3 described later. Also, the maximum swing position of each of the first and second group blade drive pins 28 and the second group blade blade cam grooves 21a and 22a when the apparatus is rotated counterclockwise from the initial position is determined by each of the first and second swing positions. The second group blades 21 and 22 are configured so as to be opened from their respective closed positions to the maximum second maximum opening position S2 'of the second group blade. Therefore, the second group blade cam grooves 21a, 22a
Will be formed in a cam shape that can serve such purpose.

The initial position and the maximum swing position of the second group blade drive lever 25 are set on the inner end surfaces of both the second restricted circular arc groove 3 and the second corresponding circular arc groove 6. Alternatively, it may be configured to be set on the inner end surface of the second corresponding circular arc groove 6.

As a result, in the second group blade means 20, as in the case of the first group blade drive lever 15 described above, the second group blade drive lever 25 moves counterclockwise from its initial position around the pivot 26. The second group blade drive pin 28
Of the second group blade cam grooves 21a and 22a are simultaneously fitted in the second group blade cam grooves 21a and 22a, and are displaced substantially in the radial direction.
The second group blades 21 and 22 are opened from their respective closed positions to the second group blade maximum over-opening position S2 'at the maximum.
On the contrary, when the second group blade drive lever 25 rotates clockwise from the position after rotation (the maximum swing position), the second group blades 21 and 22 are moved to the second group blade maximum over-open position S2 '. Will act to close from the to the closed position.

The opening / closing operation of the second group blades 21 and 22 will be described again in the section of the structure of the exposure calculation circuit 65 described later.

Now, in the peripheral area of the substrate 1 described above, the first limiting arc groove 2 for penetrating the first group blade driving pin 17 of the first group blade driving lever 15 and the second group blade driving lever 2 are formed.
The second limiting arcuate groove 3 that penetrates the second group blade drive pin 28 of No. 5 is formed.

The shape of the first restricted circular arc groove 2 is formed so that the inner end surface 2a on one side can define the initial position of the drive pin 17, and the inner end surface 2b on the other side drives the first group blade. It is formed so that the position of the maximum amount of rotation of the pin 17 can be defined.

In this case, in the illustrated embodiment, the drive pin 17
Is set as the closing position of the first group of blades 11, 12, and the position of the maximum rotation amount is set as the first group of blades 11, 12.
Is set as the maximum excessive opening position S1 'of the first group blade.

On the other hand, the shape of the second limiting arc groove 3 is formed so that at least one inner end surface 3a thereof can define the initial position of the drive pin 28, and the other inner end surface has the second group blade. 21 and 22 are set as positions which allow the maximum open position S2 'to be opened. In this case, in the illustrated embodiment, the initial position of the drive pin 28 is set as the closed position of the second group blades 21, 22.

Reference numeral 4 designates the first group blades 11 and 12 and the second group blade 2
The first group of blades 11 and 12 and the second group of blades 2 are blade group suppressing plates for suppressing the lift of the first and second groups 22 and 22 in the optical axis O direction.
The field of the substrate 1 is appropriately fixed so as to face the substrate 1 with an optical axis (hereinafter, referred to as “on-axis”) distance between them so that they can smoothly open and close. It is arranged on the side.

A photographing light passage hole 4a having a diameter slightly larger than the diameter of the aperture 1a on the substrate 1 side is formed in the central area of the blade group restraining plate 4, and a plurality of necessary peripheral areas are provided. An escape hole 4 with a specified diameter
b is formed.

Further, a first corresponding circular arc groove 5 is provided at a portion of the peripheral region facing the first restricted circular arc groove 2 of the substrate 1,
In addition, the second corresponding circular arc groove 6 is also provided at a position facing the second restricted circular arc groove 3.

In this case, the respective shapes of the first corresponding circular arc groove 5 and the second corresponding circular arc groove 6 are substantially the same as the first limiting circular arc groove 2 and the second limiting circular arc groove 3, respectively. Alternatively, it may be formed in a shape larger than the first restricted circular arc groove 2 and the second restricted circular arc groove 3.

Reference numeral 30 denotes an aperture ring rotatably fitted in the large-diameter cylindrical portion 1b of the base plate 1, and the aperture setting cam groove 31, the one-way interlocking portion 32, and the cam type ratchet tooth row 33 (described later) in the peripheral region thereof. And is configured to be always rotated counterclockwise by an appropriate biasing force of the biasing spring 34.

In this case, in the illustrated embodiment, the diaphragm ring 3
The initial position of 0 is set as the position where the one-way interlocking portion 32 of the aperture ring 30 contacts the one-way interlocking pin 41 on the drive ring 40, but a stopper member (not shown) for setting the initial position is provided in advance. Alternatively, the stop ring 30 may be configured to set the initial position of the diaphragm ring 30.

Further, the aperture setting cam groove 31 holds the first group blades 11 and 12 in the respective closed positions when the aperture ring 30 is in the initial position, and the aperture ring 30 rotates clockwise from the initial position. When the intermediate transmission pin 18 →
First group blade driving lever 15 → Through the first group blade driving pin 17, the first group blades 11 and 12 can be opened from the respective closed positions to the first group blade maximum over-opening position S1 ′ at maximum. The cam shape is set.

In this case, in the illustrated embodiment, the first group blade 1
While the one-way interlocking portion 32 of the aperture ring 30 abuts the one-way interlocking pin 41 on the drive ring 40 in a region beyond the closing side of the cam region that opens and closes the first and the second apertures 12 in a predetermined manner, It is configured to provide a margin area having a shape capable of holding the first group blades 11 and 12 in the closed state even when the first group blades 11 and 12 are rotated counterclockwise from the initial position.

The operation of the aperture setting cam groove 31 including the margin area will be described again in the section "Operation or Operation".

The one-way interlocking portion 32 is provided with the drive ring 4 when the drive ring 40, which will be described later, is rotated clockwise.
0 is pressed by the one-way interlocking pin 41, and by this pressing action, the aperture ring 30 is rotated integrally with the drive ring 40 in the clockwise direction, and conversely, the drive ring 40 is rotated in the counterclockwise direction. At times, it is configured to have a shape or structure capable of breaking the interlocking relationship with the drive ring 40.

That is, when the drive ring 40 rotates counterclockwise, only the drive ring 40 can independently rotate counterclockwise.

The cam-type ratchet tooth row 33 has a function to prevent the diaphragm ring 30 from rotating in the counterclockwise direction by the cooperation of a ratchet claw portion 35a of a locking lever 35 described later. It is formed as a row, for example as a tooth row with a number N of teeth.

In this case, the cam type ratchet tooth row 33 is
When the rotation angle amount of the diaphragm ring 30 is small, the effect of the cam amount is small, and when the rotation angle amount of the diaphragm ring 30 is large, the effect of the cam amount is large as the rotation angle amount is large. Is configured to be formed.

Furthermore, in the illustrated embodiment, the pitch angle per tooth of the ratchet tooth row 33 (inter-tooth pitch angle) is a stepwise unit rotation angle (hereinafter, referred to as "the pitch angle between teeth" which constitutes the rotation amount of the drive ring 40 described later). (Also referred to as "unit step angle") or an integer multiple of the unit step angle.

The relative positional relationship between the number of teeth of the cam type ratchet tooth row 33 and the ratchet pawl portion 35a of the locking lever 35 will be described later in the description of the exposure calculation circuit 65.
Further, the details of the operation or operation of the basic cam surface and the cam type ratchet tooth row 33 will be respectively described later in the section "Operation or Operation".

In the illustrated embodiment, a combination mechanism of the ratchet tooth row and the ratchet pawl is adopted as the means for preventing the counterclockwise rotation of the diaphragm ring 30, but this mechanism is used in the forward and reverse directions. Allows a rotatable member to rotate in one direction but locks (blocks) rotation in the other direction.
This is a specific example of the one-way rotation (rotation) locking mechanism. Therefore, it should be noted that other types of mechanisms or means capable of achieving essentially the same purpose can be substituted.

Reference numeral 35 is a locking lever provided in correspondence with the cam-type ratchet tooth row 33 of the aperture ring 30, which is rotatably supported by a pivot 36 planted on the film side surface of the substrate 1 and The urging force of an appropriate urging spring 37 is configured to always rotate in the clockwise direction.

This locking lever 35 has a cam type ratchet tooth row 3 of the diaphragm ring 30 at the tip of one arm thereof.
A ratchet claw portion 35a that can be engaged with the second timing cam surface 3 that can abut the second timing pin 43 of the drive ring 40 at the tip of the other arm.
It is also configured to have 5b.

In this case, the ratchet pawl portion 35a is constructed so as to be constantly pressed against the cam type ratchet tooth row 33 by the urging force of the urging spring 37 for urging the locking lever 35, and the diaphragm ring 30 is clockwise. When turning, the push-up action of each tooth of the cam type ratchet tooth row 33 escapes outward against the urging force of the urging spring 37, and when the diaphragm ring 30 rotates counterclockwise, The urging force of the urging spring 37 cuts into between the teeth of the cam-type ratchet tooth row 33 to act to prevent (lock) the turning operation of the throttle ring 30 at that time.

Reference numeral 40 denotes a drive ring rotatably fitted to the small diameter cylindrical portion 1c of the substrate 1 so as to face the aperture ring 30 at a predetermined distance on the optical axis O, and an intermediate portion which will be described later in the peripheral region thereof. The gear 52 includes a gear portion 40a that meshes with the small-diameter gear 52b of the gear 52, and further projects in the radial direction.
It is configured to have a first corner portion 40b and a second corner portion 40c at a portion.

Reference numeral 41 is a one-way interlocking portion 32 of the aperture ring 30.
Is a one-way interlocking pin that can be brought into contact with the one-way interlocking pin 41, which is planted on the side surface of the driving ring 40 in the field of view, and the planting position is the one-way interlocking pin 41 when the drive ring 40 is in the initial position. Is set at a position where it comes into contact with the one-way interlocking portion 32.

Reference numeral 42 denotes a first timing pin which is planted on the side surface of the first corner portion 40b of the drive ring 40 on the side of the object field, and drives the second group blade when the drive ring 40 rotates counterclockwise. The second group blade drive lever 25 is configured to come into contact with the first timing cam surface 25a of the lever 25 and forcibly rotate counterclockwise against the urging force of the urging spring 27. .

Reference numeral 43 is a second timing pin which is planted on the side surface of the second corner portion 40c of the drive ring 40 on the side of the object field. When the drive ring 40 is rotated in the counterclockwise direction, the locking lever 35 is locked. It is configured to come into contact with the second timing cam surface 35b and to forcibly rotate the locking lever 35 counterclockwise against the biasing force of the biasing spring 37.

Regarding the relative positional relationship between the first timing pin 42 and the first timing cam surface 25a, and the relative positional relationship between the second timing pin 43 and the second timing cam surface 35b, "operation or action" is described. Section will be explained again.

Further, the diaphragm ring 30 and the drive ring 4
0 is configured to fit into the large-diameter cylindrical portion 1b and the small-diameter cylindrical portion 1c of the substrate 1 with a structure in which substantial movement in the axial direction is prevented by appropriate means.

Reference numeral 50 denotes an electric motor which is rotationally driven in forward and reverse directions based on a command from a motor drive control circuit 67 of an electric control means 60 which will be described later, and is rotationally driven by a pulse signal such as a stepping motor. It is configured as an appropriate electric motor having a structure known per se.

In this case, in the illustrated embodiment, the electric motor 5
The stepwise unit rotation angle of 0 in the forward and reverse directions is the drive ring 40.
The unit step angle (which is also the aperture ring 30) is set to be the same angle or an integral multiple thereof.

Reference numeral 51 denotes an appropriate output gear attached to the output shaft (not shown) of the electric motor 50. The output drive gear 51 outputs the rotational driving force of the electric motor 50 in the forward and reverse directions.
Large diameter gear 5 of the intermediate gear 52 formed as a two-stage gear
2a → small diameter gear 52b of intermediate gear 52 → drive ring 40
The gears 40a are transmitted in this order, and the drive ring 40 can be rotationally driven from its initial position in the clockwise direction and the counterclockwise direction, respectively.

FIG. 3 is a block diagram relating to the electric control means 60 for controlling the camera shutter device of the illustrated embodiment.

In FIG. 3, reference numeral 61 denotes a photometric circuit which constitutes the electric control means 60 and has an appropriate structure known per se. The photometric data at that time is measured and the photometric data is described later. It is configured to be output to the exposure calculation circuit 65 via the sequence control circuit 63.

Reference numeral 62 denotes a CPU which constitutes the electric control means 60 and which has an appropriate structure known per se, and has therein a circuit program necessary for controlling the camera and the camera shutter device of the illustrated embodiment. It is configured to have software means such as at least a sequence control circuit 63, an opening area determination circuit 64, an exposure calculation circuit 65, and an output confirmation means 66.

The sequence control circuit 63 uses the camera normally (including photometry operation and automatic distance measurement operation).
And a shutter operation sequence for controlling the camera shutter device of the illustrated embodiment so as to be suitable for its purpose (hereinafter, both are collectively referred to as "imaging sequence"). It is configured as a sequence control circuit capable of controlling

The aperture area determination circuit 64 is the exposure calculation circuit 6
Based on the output from 5, the exposure condition at that time is an exposure condition (luminance) at which the exposure operation or the photographing operation should be performed with the aperture opening (triangular opening waveform) smaller than the aperture opening Sa.
Or the exposure condition for performing the exposure operation with the aperture opening Sa (trapezoidal opening waveform).

The relationship between the execution of the determination calculation in the aperture area determination circuit 64 and the execution of the proper aperture value and the proper shutter time value in the exposure calculation circuit 65 may be performed first. Therefore, the order of execution can be arbitrarily set at the designing stage, and the determination calculation by the opening region determination circuit 64 can be performed as follows.
It should be noted that the exposure calculation circuit 65 may be configured to be executed together with the calculation of the proper aperture value and the proper shutter time value.

The exposure calculation circuit 65 is configured to execute various calculations for controlling the camera shutter device. Hereinafter, regarding the calculation in the exposure calculation circuit 65,
A description will be given in connection with the opening and closing operations of the first group blades 11 and 12 and the second group blades 21 and 22, respectively, and also with reference to FIGS. 6 and 8.

[Opening / closing operation of the first group blades 11, 12 and the second group blades 21, 22 under the condition that the exposure operation should be performed with the aperture opening smaller than the aperture opening Sa] (A) With the aperture opening smaller than the aperture opening Sa Under the condition that the exposure operation should be performed (referred to as “the condition when the exposure operation is performed at the small aperture”), the electric motor 50
When the drive ring 40 and the diaphragm ring 30 are integrated by the rotational driving force in the positive direction of the first group blade, the first group blades are rotated clockwise from their initial positions by a small diaphragm rotation amount to be described later. 11 and 12 from the closed position to the first group pinhole position and the aperture opening position S (hereinafter, referred to as “appropriate aperture opening position”) S that can realize the appropriate aperture value at each time, and then the first at each time described later. Excessive open position of group blade S1
Configured to open up.

In this case, the first group blade excessive opening position S1 at each time is preconfigured so as to be set to an opening level position which exceeds the opening level of the appropriate aperture opening position S at each time by an appropriate amount. Further, the rotation amount of the drive ring 40 at each small aperture time is set as a rotation amount capable of opening the first group blades 11 and 12 from the closed position to the first group blade excessive opening position S1 at each time. become.

As a result, the open / close range of the first group blades 11 and 12 under the condition that the exposure operation should be performed at the small aperture is, for example, the aperture value of the camera is F2.5, and the aperture value is one step higher than the aperture value. Assuming that the previously set front aperture value is F2.8, for example, the range is from the closed position to the excessive open position corresponding to the front aperture value F2.8.

The first group blades 11 and 12 opened to the first group blade excessive opening position S1 at that time are applied to the diaphragm ring 30 at the preset closing start time R at the time of the small aperture. The closing operation is started toward the closing position by the urging force of the urging spring 34.

In this case, the closing operation start time point R at the time of the small aperture described above is set to the time point after the second group blades 21 and 22 are opened from the closed position to at least the position exceeding the second group pinhole position. It is configured to be. In addition,
Relationship between the proper aperture opening position S and the first group blade over-opening position S1 and the closing operation start time point R at the time of the small aperture described above
This will be explained again later in the section of "motion or action".

(B) In the illustrated embodiment, the drive ring 40
The following three relations are set with respect to the rotation amount of each of the small apertures, the cam type ratchet tooth row 33 of the aperture ring 30, and the ratchet pawl portion 35a of the locking lever 35.

That is, the drive ring 40 (diaphragm ring 3
(Also 0) is rotated by the small throttle rotation amount at each time, the ratchet claw portion 35a of the locking lever 35 causes the cam type ratchet tooth row corresponding to the first group blade over-open position S1 at that time. It is set so that 33 specific teeth can be locked.

Then, the rotation amount corresponding to the largest excessive opening position of the drive ring 40 under the condition that the exposure operation at the time of the small aperture should be performed (for example, the rotation amount corresponding to the excessive opening position corresponding to the preceding aperture value F2.8). ), The ratchet pawl portion 35a of the locking lever 35 is set so as to be able to lock the N-1th specific tooth of the cam type ratchet tooth row 33.

As a result, the rotation range of the aperture ring 30 under the condition that the exposure operation at the time of the small aperture is to be performed is maximum, from the initial position to N−1 of the cam type ratchet tooth row 33.
It is limited to the range up to the position (hereinafter referred to as N-1 tooth position) where the specific tooth of the tooth can be locked by the ratchet claw portion 35a.

(C) On the other hand, the second group blades 21, 22 are
A predetermined time point (hereinafter referred to as "opening operation start time point P of the second group blades 21, 22 P") set after the first group blades 11, 12 have been opened to the first group blade over-opening position S1. )) By the rotational driving force of the electric motor 50 in the reverse direction, from the closed position to the second group pinhole position, and then at the time of small aperture second group blade excessive open position S2.
Configured to open up.

In this case, the position of the opening operation start time point P of the second group blades 21 and 22 is the same as the closing position of the second group blades 21 and 22, or the position closer to the closing position than the second group pinhole position. It is set to another position on the side close to, but this can be arbitrarily determined at the design stage. Note that a specific method of setting the opening operation start time point P will be described in detail in the section "Operation or Action" described later.

On the other hand, the occasional small aperture second group blade excessive opening position S2 is set to an appropriate opening level position which exceeds the occasional first group blade excessive opening position S1 of the first group blades 11 and 12. It shall be configured in advance so as to be performed.

Then, the second group blades 21, 22 opened to the second group blade excessive opening position S2 at the time of small aperture at each time are the points after the electric motor 50 is reversed at the reverse → forward / reverse timing at the time of small aperture. In the above, the closing operation is started toward the closing position by the urging force of the urging spring 27 applied to the second group blade drive lever 25. The reverse → normal inversion timing at the time of the small aperture is set at an appropriate point in the design stage.

As a result, the largest opening / closing range of the second group blades 21, 22 under the condition that the exposure operation should be performed at the small aperture is, for example, the open aperture value of the camera is F2.5, and the preceding aperture value is Is assumed to be F2.8, for example, the range is from the closed position to the small aperture second group blade excessive open position S2 corresponding to the first group blade excessive open position S1 related to the front aperture value F2.8. In the illustrated embodiment, the second group pinhole position is set as the timing reference position when the proper exposure amount is formed.

[Calculation by the exposure calculation circuit 65 under the condition that an exposure operation should be performed with an aperture opening smaller than the aperture opening Sa] (D) From the aperture area determination circuit 64, the aperture opening Sa
When the result of determination that the exposure operation is performed with a smaller aperture opening is output, the exposure calculation circuit 65 adapts to the subject brightness at each time based on the photometric data output from the photometric circuit 61. The appropriate aperture value related to the appropriate EV value is calculated.

At the time of a small aperture in the clockwise direction of the drive ring 40 (aperture ring 30) necessary for opening the first group blades 11 and 12 from the closed position to the first group blade over-opening position S1 at that time. The rotation amount in the positive direction from the initial phase of the electric motor 50 necessary for calculating the rotation amount and further obtaining the rotation amount of the drive ring 40 at the time of small aperture (hereinafter, referred to as “opening rotation number at the time of small aperture”) and , And the number of forward drive pulses that can realize this rotation speed.

At the same time, for example, at the same time, the reverse rotation speed of the electric motor 50 required to rotate the drive ring 40 counterclockwise from the position after the rotation amount of the small aperture to the initial position (hereinafter, "Returning rotational speed at the time of small aperture") and the number of reverse driving pulses that can realize this rotational speed are calculated.

As a matter of course, the return rotation speed at the small aperture becomes the same rotation speed as the opening rotation speed at the small aperture even though the rotation directions are different, and the maximum opening rotation speed at the small aperture and the return rotation at the small aperture are set. The maximum number is, for example, the maximum aperture value of the camera is F2.5 and the previous aperture value is F2.8, for example.
In each case, the drive ring 40 is closed and the largest over-open position (for example, the front aperture value F
It is the number of rotations when reciprocating between the position corresponding to the excessive open position in 2.8).

(E) The normal-to-reverse reversal timing at the small aperture is set so that the rotation direction of the electric motor 50 is reversed from the forward direction to the reverse direction at the time when the rotation of the aperture speed at the small aperture at each time is completed. Calculate to set.

(F) The amount of rotation of the drive ring 40 in the counterclockwise direction required to open the second group blades 21 and 22 from the closed position to the second group blade over-open position S2 at the time of small aperture ( Hereinafter referred to as "second group blade excessive opening rotation amount")
Is calculated, and further, when the drive ring 40 has a small aperture, the second
Electric motor 50 necessary to obtain the amount of excessive rotation of the group blade
Reverse rotation speed from the initial phase of
"Group blade excess opening rotation speed") and the number of reverse drive pulses that realize this rotation speed are calculated.

Further, for example, at the same time, the electric motor 50 necessary for returning the drive ring 40 clockwise from the position after rotating the drive ring 40 counterclockwise by the excessive opening rotation amount of the second group blades to the initial position. The rotation speed in the positive direction (hereinafter, referred to as the "return speed of the second group blade at the time of small aperture") and the number of forward driving pulses that realizes this rotation speed are calculated.

Naturally, the returning speed of the second group blades at the small aperture is the same as the excessive opening speed of the second group blades at the small aperture even though the rotating directions are different.

(G) The reverse → forward reversal timing at the time of a small aperture when reversing the phase of the electric motor 50 after the reverse rotation at this time to the normal rotation is, for example, the electric motor 50.
Is calculated from the initial phase to a point when the rotation of the second group blade excessive opening rotation speed at the time of small aperture has ended.

As will be described later, the reverse → forward reversal timing at the time of the small aperture is set such that the first group blades 11 and 12 substantially move from the first group blade excessive opening position S1 to the first group pinhole. It may be set after the point of closing to the position.

[Opening / closing operation of the first group blades 11 and 12 and the second group blades 21 and 22 under the condition that the exposure operation should be performed with the aperture opening Sa] (a) The drive ring 40 and the diaphragm ring 30 are electric motors. When the rotational driving force of 50 in the positive direction causes the first group blades 11 and 12 to rotate clockwise from their respective initial positions by the aperture opening realizing rotation amount (described later),
It is configured to open from the closed position through the first group pinhole position and the aperture opening Sa to a preset first group blade maximum excessive opening position S1 '.

In this case, the maximum excessive opening position S of the first group blade
1'is an aperture level position that exceeds the position of the aperture opening Sa by an appropriate amount, for example, the open aperture value of the camera is F2.
Assuming that it was 5, it was set as an excessive open position corresponding to this open aperture value F2.5, and the drive ring 4
The aperture opening realizing rotation amount of 0 is the first group blades 11, 1
2 from the closed position to the maximum excessive opening position S1 of the first group blade
It is set as the amount of clockwise rotation that can be opened up to ′.

(B) Drive ring 40 (diaphragm ring 30)
However, after rotating by the aperture opening realizing rotation amount, only the drive ring 40 drives the electric motor 50 to rotate in the opposite direction, as in the case where the exposure operation at the time of the small aperture is to be performed. Due to the force, the maximum excessive opening position S of the first group blade
It rotates counterclockwise from the position corresponding to 1'and returns to the initial position.

At this time, the aperture ring 30 is locked by the ratchet claw portion 35a of the locking lever 35 at the position when it is rotated by the aperture opening realizing rotation amount, and the first group blades 11 and 12 are moved to the first group blades 11 and 12. The group blade is configured to be held in the open state at the maximum excessive opening position S1 '.

In this case, in the illustrated embodiment, the drive ring 4
The following three relations are set with respect to the aperture opening realizing rotation amount of 0, the cam type ratchet tooth row 33 of the aperture ring 30, and the ratchet pawl portion 35a of the locking lever 35.

When the drive ring 40 is rotated by the rotation amount for realizing the aperture opening, the N-th specific tooth of the cam-type ratchet tooth row 33 of the aperture ring 30 is locked by the ratchet pawl portion 35 a of the locking lever 35. Possible positions (below,
It is set in advance so that it is located at the “N tooth position”. That is, the rotation range of the aperture ring 30 under the condition that the exposure operation should be performed with the aperture opening Sa,
Set it so that it is in the range from the initial position to the N tooth position.

(C) Drive ring 4 returned to the initial position
Zero is further rotated counterclockwise from the initial position after returning in two steps by the rotation driving force of the electric motor 50 in the opposite direction.

Then, by the counterclockwise rotation of the first stage of the drive ring 40, the second group blades 21 and 22 are moved,
From the closed position, through the second group pinhole position and the aperture opening Sa, the second group blade aperture opening realization position (use the same symbol as the first group blade maximum excessive opening position S1 ')
To open up.

In this case, in the illustrated embodiment, the second group blade 2
The closed positions of 1 and 22 are not the positions of the opening operation start time point P of the second group blades 21 and 22, and the second group blade aperture opening realization position S1 'is, for example, the above-described first group blades 11 and 12. First group blade maximum excess opening position S1
It is preconfigured to be set at the same opening level position as that of '.

(D) When the second group blades 21 and 22 are opened to the second group blade aperture opening realization position S1 ', after the elapse of a preset predetermined time, the counterclockwise direction of the second stage of the drive ring 40 The rotation of the lock lever 35 releases the locking action of the ratchet pawl portion 35a of the locking lever 35 to the aperture ring 30.

Then, at the preset closing operation start time point R'at the time of the open aperture, the first group blades 11 and 12 which have been opened to the maximum excessive opening position S1 'of the first group blade are given to the aperture ring 30. The urging force of the urging spring 34 returns the first group blade maximum overopen position S1 'to the closed position.

As a result, the second group blades 21, 22 under the condition that the exposure operation should be performed with the aperture opening Sa.
The maximum open / close range is between the closed position and the second group blade maximum excess open position S2 '(see FIG. 8).

[Calculation by the exposure calculation circuit 65 under the exposure condition that the exposure operation should be performed with the aperture opening Sa] (e) From the aperture area determination circuit 64 to the aperture opening Sa
When the result of determination that the exposure condition is to be performed is output, the exposure calculation circuit 65, based on the photometric data output from the photometric circuit 61, determines an appropriate EV value that matches the subject brightness at that time. The combination of the appropriate aperture value and the appropriate shutter time value that can realize the above is calculated, and further, the first group blades 11 and 12 are closed to realize the appropriate shutter time value that matches the appropriate EV value at that time. A delay time for determining the operation start time point R'is calculated.

In this case, in the illustrated embodiment, this delay time is calculated as a delay time calculated from the time point when the second group blades 21, 22 start the opening operation from the closed position (that is, the opening operation start time point P). is doing.

However, the calculated delay time is just a delay time for sequence control, and in terms of exposure conditions,
It is additionally noted that the delay time is calculated from the time when the second group blades 21 and 22 reach the second group pinhole position.

(F) The aperture opening realizing rotation amount of the drive ring 40 required to open the first group blades 11 and 12 from the closed position to the first group blade maximum excessive opening position S1 'is calculated, and further, this is calculated. The positive rotation speed from the initial phase of the electric motor 50 (hereinafter, referred to as “aperture opening realization rotation speed”) necessary to obtain the clockwise rotation amount of the drive ring 40 at this time and this rotation speed are realized. The number of positive drive pulses to be obtained is calculated.

At the same time, for example, the reverse rotation speed of the electric motor 50 required to return the drive ring 40 to the initial position from the position after the rotation amount for realizing the aperture opening (hereinafter, "reverse reverse initial position return rotation speed"). ") And the number of reverse driving pulses that can realize this rotation speed. As a matter of course, the reverse initial position return rotation speed is
Even if the rotation direction is different, the rotation speed is the same as the aperture opening realization rotation speed.

(G) In order to reverse the rotation direction of the electric motor 50 from the forward direction to the reverse direction at the time when the rotation of the aperture opening realization rotation speed is completed, the forward → reverse inversion timing at the opening of the aperture is set. Calculate to.

(H) The amount of rotation of the drive ring 40 in the counterclockwise direction required to open the second group blades 21, 22 from the closed position to the second group blade aperture opening realization position S1 '(hereinafter referred to as "the first group"). The second-group blade aperture opening realization rotation amount ") is calculated, and the reverse rotation speed from the initial phase of the electric motor 50 necessary for obtaining the rotation amount of the drive ring 40 in the clockwise direction at this time (hereinafter referred to as" reverse rotation speed "). , "Second group blade aperture opening realization rotational speed") and the number of backward drive pulses that can realize this rotational speed.

In this case, the second group blade aperture opening realizing rotation amount of the drive ring 40 is driven when the driving ring 40 rotates counterclockwise by the second group blade aperture opening realizing rotation amount from the initial position. The second timing pin 43 on the ring 40 is set to such a rotation amount that it does not come into contact with the second timing cam surface 35b of the locking lever 35 that locks the N-th specific tooth.

(I) The rotation amount of the drive ring 40 required to open the second group blades 21 and 22 from the second group blade aperture opening realizing position S1 'to the second group blade maximum over-opening position S2' ( Hereinafter, "the second group blade maximum excess opening rotation amount") is calculated, and the reverse rotation speed of the electric motor 50 necessary to obtain the rotation amount of the drive ring 40 in the counterclockwise direction at this time ( Hereinafter, "the second group blade maximum excess opening rotation speed") and the number of reverse drive pulses that can realize this rotation speed are calculated.

In this case, the maximum excessive opening rotation amount of the second group blade of the drive ring 40 is determined by the aperture ring 30 in the illustrated embodiment.
Is set as a rotation amount for rotating from the specific tooth of the Nth tooth by an angle corresponding to one tooth of the cam type ratchet tooth row 33, and the second group blade maximum excessive opening rotation of the electric motor 50 is set. The number is set as the number of rotations that can realize the maximum excessive opening rotation amount of the second group blade of the drive ring 40 at this time.

(J) The timing for opening the second group blades 21, 22 from the second group blade aperture opening realizing position S1 'to the second group blade maximum excessive opening position S2' is as described above when the aperture is opened. The calculation is performed so as to set the closing operation start time R'of. In the following description, the timing at this time will be referred to as the first group closing timing when the aperture is opened.

(K) The drive ring 40 rotated by the total amount of the second group blade aperture opening realizing rotation amount and the second group blade maximum excessive opening rotation amount is moved to the second group blades 21 and 22.
A clockwise rotation amount (hereinafter referred to as "drive ring reset rotation amount") for returning from the rotation position corresponding to the group blade maximum excessive opening position S2 'to the initial position is calculated,
Further, the forward rotation speed of the electric motor 50 (hereinafter referred to as “drive ring reset rotation speed”) necessary to obtain the clockwise rotation amount of the drive ring 40 at this time, and this rotation speed can be realized. The number of reverse driving pulses is calculated.

The drive ring reset rotation speed is different from the rotation direction, but the same rotation speed as the total rotation speed of the second group blade aperture opening realization rotation speed and the second group blade maximum excess opening rotation speed described above. Become.

(L) The drive ring 40 rotated by the total amount of the second group blade aperture opening realizing rotation amount and the second group blade maximum excessive opening rotation amount is moved to the second group blades 21 and 22 by the second ring.
Timing for returning from the rotational position corresponding to the group blade maximum excessive opening position S2 'to the initial position, that is, reversal timing for reversing the rotation direction of the electric motor 50 from the reverse direction to the forward direction (hereinafter, referred to as "aperture"). "Reverse at the time of opening → forward reverse timing"), the first group blade 11,
It is calculated so as to be set at an appropriate time after 12 reaches at least substantially the first group pinhole position.

At an appropriate time after the first group blades 11 and 12 reach the first group pinhole position, it is necessary to confirm the end of exposure by the closing operation of the first group blades 11 and 12. Although it can be set at any time,
The time shall be set as early as possible in consideration of shortening the shooting sequence.

Further, as a concrete setting method thereof, for example, the delay time for determining the closing operation start time point R'at the time of the above-mentioned opening is used as a reference, and the first group blade 1
The closing operation times of 1 and 12 are set in consideration.

(M) From the phase when the electric motor 50 is rotated by the total number of rotations of the second group blade aperture opening realization number of rotations and the second group blade maximum excess opening number of rotations, only the drive ring reset rotation number is positive. When it finishes rotating in the direction,
The calculation is performed so as to stop the rotation drive of the electric motor 50.

The output confirming means 66 is means for electrically or photoelectrically confirming whether or not the drive pulses in the forward and reverse directions from the exposure calculation circuit 65 are actually output. It is configured as a means using a known appropriate structure or method.

In this case, the output confirmation means 66 is provided, for example, with the first group blade and / or the second group blades (11, 12), (2
1, 22) each having an appropriate structure known per se at the initial position and the required open position, for example, a photoelectric position detecting means is installed, and the output from the photoelectric position detecting means is sequence-controlled. As input to the circuit 63, the first group blade and / or the second group blade (11,
12) and (21, 22) can also be configured as a means capable of monitoring the opening / closing operation.

Reference numeral 67 is a motor drive control circuit having an appropriate structure known per se which constitutes the electric control means 60, and an exposure calculation circuit 65 is provided via the sequence control circuit 63.
The electric motor 50 can be rotationally driven based on the number of forward drive pulses or the number of reverse drive pulses instructed from

Next, the operation or action of the camera shutter device of the illustrated embodiment will be described with reference to the flowchart of FIG.

While setting the camera to the operating state, for example, a shutter release operating member (not shown) configured in a two-step stroke type is operated only for the first step stroke,
The photometric operation is started [step 1].

When operated in this manner, the photometric circuit 61
First, since the photometric data relating to the subject at that time is output to the aperture area determination circuit 64 and the exposure calculation circuit 65, the exposure calculation circuit 65, based on the photometry data, selects the appropriate aperture value and the appropriate aperture value for the field at that time. The shutter speed value is calculated [step 2].

At this time, at substantially the same time, the aperture area judgment circuit 64 judges the exposure operation condition at that time based on this photometric data, and the judgment result is the sequence control circuit 6
3 is output [Step 3].

[Exposure operation with an aperture smaller than the aperture opening Sa] If the result of the determination from the aperture area determination circuit 64 is that the exposure operation should be performed with an aperture opening smaller than the aperture opening Sa, then the user In this state, the second shutter release operation member
The stepped stroke is operated to start the camera shutter device.

When the camera shutter device is started, the sequence control circuit 63 first commands the exposure calculation circuit 65 to execute the calculations of the above-mentioned (D) to (G) terms, At the same time, the motor drive control circuit 67 is instructed to rotationally drive the electric motor 50 based on the calculation output from the exposure calculation circuit 65.

In this case, assuming that the proper aperture value for the object field at that time is, for example, F5.6, the motor drive control circuit 67 first outputs the aperture value at the time of the small aperture value output from the exposure calculation circuit 65. The electric motor 50 is rotationally driven in the positive direction from the initial phase at the rotation speed (F5.6 corresponding opening rotation speed) [step 4].

Therefore, the electric motor 50 is rotated by the aperture speed at the time of the small aperture at this time, and the rotational force in the positive direction is changed to the output gear 51 → the large diameter gear 52a of the intermediate gear 52 → the small diameter of the intermediate gear 52. It is transmitted to the drive ring 40 via the gear 52b → the gear portion 40a of the drive ring 40 (hereinafter, referred to as the “output gear 51 → the gear portion 40a”).

When the drive ring 40 is rotated clockwise from the initial position by the small aperture rotation amount at that time, the one-way interlocking pin 41 on the drive ring 40 pushes the one-way interlocking portion 32 of the aperture ring 30. By moving, the diaphragm ring 30 is forcibly rotated in the clockwise direction integrally with the drive ring 40 against the urging force of the urging spring 34.

At this time, each tooth of the cam type ratchet tooth row 33 of the drive ring 40 resists the biasing force of the biasing spring 37 against the ratchet pawl portion 35a of the locking lever 35 in the course of the rotation of the aperture ring 30. It pushes up one after another and is displaced. Therefore, the clockwise rotating operation of the diaphragm ring 30 is performed as planned without being obstructed by the ratchet pawl portion 35a.

When the diaphragm ring 30 and the drive ring 40 are integrally rotated in this manner, the diaphragm setting cam groove 31 on the diaphragm ring 30 has a cam action during the rotation process of the intermediate transmission pin 18. Is displaced in the direction away from the optical axis O, and the first group blade drive lever 15 is swung counterclockwise.

Therefore, the first group blade drive lever 15 is
By the swinging operation at this time, the first group blade drive pin 17 is displaced in a substantially radial direction from the optical axis O, and the first group blade drive pin 17 and the first group blade cam grooves 11a and 12a are mutually displaced. The cam action causes the first group blades 11, 12 to perform a predetermined opening operation.

As a result, each first group blade 11, 12
Perform an opening operation from the respective closed positions (initial positions) in directions opposite to each other, pass through the first group pinhole position and the proper aperture opening position S, and then reach the appropriate aperture value F5.6 at that time.
To the first group blade excessive opening position S1 (for example, the position of the opening level shown by the alternate long and short dash line in FIG. 6).

However, in the process of the opening operation of the first group blades 11 and 12, the second group blades 21 and 22 are configured to be held in the closed position, and therefore the film is still not formed at this point. The surface will not be exposed.

Then, during the course of such a process, the output monitoring means 66 confirms whether or not the forward drive pulse for realizing the aperture speed at the time of the small aperture is output from the exposure operation circuit 65 according to the operation value. Then, the confirmation result is output to the sequence control circuit 63 [step 5].

When the diaphragm ring 30 is rotated by the small diaphragm rotation amount at that time, the sequence control circuit 63
A reverse drive that causes the motor drive control circuit 67 to immediately reverse the rotation direction of the electric motor 50 from the forward direction to the reverse direction at the forward-reverse timing when the small aperture is applied, and to realize the return rotational speed at the small aperture. The electric motor 50 is commanded to rotate with the number of pulses.

Therefore, the motor drive control circuit 67, at the time when the rotation of the aperture speed at the time of the small aperture is finished,
Immediately reverse the rotation direction of the electric motor 50,
The electric motor 50 is controlled so as to rotate in the reverse direction by the return rotation speed at the time of the small aperture.

Therefore, the electric motor 50 reverses at the forward-reverse reverse timing at the time of the small aperture, and the rotational force in the reverse direction is
The output gear 51 is transmitted to the drive ring 40 via the gear portion 40a, and the drive ring 40 is moved to the proper aperture value F5.6.
The group blade is rotated counterclockwise from the excessively opened position S1.

At this time, since the one-way interlocking pin 41 on the drive ring 40 is displaced in the direction away from the one-way interlocking portion 32 of the aperture ring 30, the drive ring 40 is hitherto driven by the biasing force of the biasing spring 34. The diaphragm ring 30, which is engaged so as to rotate integrally with, also tries to rotate counterclockwise at the same time, following the rotation of the drive ring 40 counterclockwise.

However, at this time, the ratchet pawl portion 35a of the locking lever 35 is moved by the urging force of the urging spring 37 to the first group blade over-open position related to the proper aperture value F5.6 of the cam type ratchet tooth row 33. Since it will bite into the specific tooth corresponding to S1, the counterclockwise rotation operation of the aperture ring 30 is performed by the ratchet pawl portion 35a at the first group blade over-opening position S1 related to the appropriate aperture value F5.6. It will be forcibly blocked.

In this case, the position of the specific tooth under the condition that the exposure operation at the time of the small aperture is to be performed is determined by the cam type ratchet tooth row 33.
It is located between the first tooth and the (N-1) th tooth.

In the illustrated embodiment, the unit step angle that constitutes the amount of rotation of the diaphragm ring 30 and the pitch angle per tooth of the cam type ratchet tooth row 33 are set to the same angle. The 30 is accurately locked at a predetermined position by the ratchet pawl portion 35a without causing a so-called "half tooth shift phenomenon".

FIG. 5 shows the state at this time. That is, the locking lever 35 has already resisted the biasing force of the biasing spring 37 by the cam action of the basic cam surface of the cam type ratchet tooth row 33, and has already reached its initial position (the position shown by the dashed line in the figure).
From the locking position shown by the solid line to the end of the counterclockwise rotation around the pivot 36, the diaphragm ring 30 is moved to the proper diaphragm value F5.6.
The first group blades 11 and 12 are held at the rotation position corresponding to the excessive opening position S1 of the first group blades, and the first group blades 11 and 12 have the proper aperture value F5.6.
To the first group blade excessive opening position S1 related to
Only the drive ring 40 is shown to be about to start rotating counterclockwise towards its initial position.

In this way, when the drive ring 40 returns to the initial position from the position corresponding to the first group blade excessive opening position S1 related to the proper aperture value F5.6, the sequence control circuit 63 causes the motor drive control circuit 67 to operate. Against this,
The electric motor 50 is commanded to rotate further with the number of reverse drive pulses that realizes the excessive opening speed of the second group blades at the time of small aperture related to the proper aperture value F5.6.

Therefore, the electric motor 50 has an appropriate aperture value F.
At the small aperture according to 5.6, the second group blade rotates at the excessive opening rotational speed, and the reverse rotational force thereof is transmitted to the drive ring 40 via the transmission path of the output gear 51 → the gear portion 40a to initialize the drive ring 40. From the position, the second group blade is rotated counterclockwise by the rotation amount of the second group blade when the aperture is small.

At this time, the first timing pin 42 on the drive ring 40 contacts the first timing cam surface 25a of the second group blade drive lever 25, and the second group blade drive lever 2
5 from the initial position to the position corresponding to the small-throttle second group blade opening end position related to the proper aperture value F5.6 counterclockwise around the pivot shaft 26 against the biasing force of the biasing spring 27. Rock to.

In this way, the second group blade drive lever 25
Is swung counterclockwise, the second group blade drive lever 25
The upper second group blade drive pin 28 causes the second group blades 21, 22 to move.
Of the second group blade cam grooves 21a, 22a of
The group blades 21 and 22 are opened to the target open position via the second group pinhole position.

Then, when the second group blades 21, 22 reach the second group pinhole position, the photographing light is already opened and the formation openings of the first group blades 11, 12 and the second group blade 21,
The light enters the film surface through the pinholes 22 and starts a predetermined exposure.

By the way, in the process in which only the drive ring 40 rotates counterclockwise from the position after the normal rotation to the initial position, the second timing pin 43 on the drive ring 40 moves to the position shown in FIG. After contacting the second timing cam surface 35b of the locking lever 35, the locking lever 35
Against the urging force of the urging spring 37, it is pushed counterclockwise around the pivot 36.

Therefore, the ratchet pawl portion 35a of the locking lever 35, which has hitherto locked the diaphragm ring 30 at the pivotal position corresponding to the first group blade over-opening position S1 related to the proper diaphragm value F5.6, is changed. , The cam type ratchet tooth row 3 by the pushing operation of the second timing pin 43 to the locking lever 35.
3, the lock action for the specific tooth corresponding to the first group blade excessive opening position S1 related to the proper aperture value F5.6 is released.

Therefore, the aperture ring 30 also has the first group blade excessive open position S1 related to the proper aperture value F5.6 due to the biasing force of the biasing spring 34 at this time point (closing time point R when the small aperture is started). Starts rotating counterclockwise from a position corresponding to, passes through the initial position of the aperture ring 30.
The one-way interlocking portion 32 continues to rotate toward the position where it contacts the one-way interlocking pin 41 on the drive ring 40.

At the same time, the aperture setting cam groove 31 on the aperture ring 30 is also displaced counterclockwise, and the first group blade drive lever 15, the first group blade drive pin 17, the intermediate transmission pin 1
The first group blades 11 and 12 through the appropriate aperture value F5.6.
The first group blade excessive opening position S1 of the first group blade starts closing toward the closing position.

By the way, during the time period in which the first group blades 11 and 12 perform the closing operation, the second group blades 21 and 22 simultaneously open from the closing position (the position at the opening operation start time point P) as described above. As shown in FIG. 6, the first group blades 11 and 12 that perform the closing operation and the second group blades 21 and 22 that perform the opening operation should cross each other during their respective movements. become.

In this case, the positions of the intersections of the movements of the first group blades 11, 12 and the second group blades 21, 22 are such that the closing operation start time R at the time of the small aperture and the second group blades 21, 22 described above. Since it is determined by the time series interval (time difference) from the opening operation start time point P, if the time difference between these two operation start time points R and P is properly selected (controlled),
It is possible to set the intersection of the movements of the first group blades 11 and 12 and the second group blades 21 and 22 to the position of the aperture level that can realize the triangular aperture waveform of the proper aperture value F5.6.

Moreover, when the positions of the movement intersections of the first group of blades 11, 12 and the second group of blades 21, 22 are set in this way, the closing operation of the first group of blades 11, 12 causes the proper aperture value F5. Since it is started from the first group blade excessive opening position S1 according to .6, the first group blade 1 at the movement intersection point
The closing operation speeds of 1 and 12 are faster than the closing operation speed in the case of the conventional shutter device using two sets of shutter blades, and the conventional flat area can be removed.

Therefore, in the illustrated embodiment, the first group blade 1
The movement crossing points of the first and second blades 21 and 22 and the second group of blades 21 and 22 may be matched with the positions of the respective aperture levels capable of realizing the triangular aperture waveform corresponding to the appropriate aperture value at that time in advance. The time difference between the closing operation start time point R of the first group blades 11 and 12 when the aperture is small and the opening operation start point P of the second group blades 21 and 22 is set by a mechanical means.

As a result, in the illustrated embodiment, the aperture opening corresponding to the appropriate aperture value (F5.6 in the case of the present description) that can realize the appropriate exposure amount of the triangular aperture waveform relating to the appropriate EV value at each time. Are formed by the closing operation of the first group blades 11 and 12 and the opening operation of the second group blades 21 and 22.

In the following description, the movement intersection point set in this way will be referred to as an appropriate aperture value intersection point. However, the closing operation at the time of a small aperture for realizing the appropriate aperture value intersection point. A specific method of setting the start time point R and the opening operation start time point P will be described later.

In this way, the first group blades 11 and 12 and the second group blade 2 which intersect with each other at the proper aperture value intersection point.
In the case of the first group blades 11 and 12, 1 and 22 are returned to the closed position through the first group pinhole position by the urging force of the urging spring 34 applied to the aperture ring 30, and the second group. In the case of the blades 21 and 22, the blades are opened to the small aperture stop second group blade opening end position related to the proper aperture value F5.6.

In this case, at the position of the appropriate aperture value crossing point, an appropriate aperture opening for realizing the appropriate aperture value F5.6 related to the appropriate EV value at that time is formed, and the first group blade 1
At the time of returning to the pinhole position of the first lens group 1 and 12, an appropriate shutter speed value combined with the appropriate aperture value F5.6 at that time is formed, and here, the appropriate EV value at that time is formed. Therefore, an appropriate exposure amount (exposure area of EV shown in FIG. 6) having a triangular aperture waveform that realizes

When the triangular aperture waveform in this case is compared with the triangular aperture waveform of the conventional shutter device using one set of shutter blades, the result as shown in FIG. 9 is obtained. this is,
It is eloquent that the shutter time t2 in the camera shutter device of the illustrated embodiment is much faster than the shutter time t1 in the conventional shutter device.

During the course of this process, the output monitoring means 66 drives the forward drive pulse that realizes the return rotational speed at the small aperture and the positive drive pulse that realizes the excessive opening rotational speed of the second group blade at the small aperture. It is confirmed whether or not the direction driving pulse is output from the exposure calculation circuit 65 according to the calculated value, and the confirmation result is output to the sequence control circuit 63 [step 6].

When the second group blades 21, 22 are opened to the small aperture second group blade opening end position related to the proper aperture value F5.6, the sequence control circuit 63 causes the first group blades 11, 12 to be opened.
At the point after the point substantially reaches the first group pinhole position,
With respect to the motor drive control circuit 67, the rotation direction of the electric motor 50 is reversed from the reverse direction to the forward direction at the reverse → normal reverse timing at the time of the small aperture, and the electric motor 50 is rotated at the second group blade return rotation at the time of the small aperture. It is instructed to drive the rotation with the number of forward drive pulses that realizes the number.

Therefore, the electric motor 50 reverses at this reverse → normal reverse timing, and the positive direction rotational force at that time is
The output ring 51 is transmitted to the drive ring 40 via the gear portion 40a, and the drive ring 40 is rotated clockwise from the position corresponding to the small aperture stop second group blade opening end position related to the proper aperture value F5.6. To return to the initial position.

As a result, the second group blade drive lever 25 also
The urging force of the urging spring 27 follows the clockwise rotation of the drive ring 40 to return it to its initial position, and in the process of this return operation, the second group blade drive pin 28 and the second group blade cam. The second group blades 21 and 22 are returned to the closed position from the opening end position of the second group blades at the time of small aperture through the cam action with the grooves 21a and 22a.

In the illustrated embodiment, in the clockwise rotation process of the drive ring 40 at this time, the one-way interlocking pin 41 on the drive ring 40 moves the one-way interlocking portion 32 of the aperture ring 30 in the clockwise direction. It is pushed to return the aperture ring 30 to its initial position at the same time.

Incidentally, the reverse → normal reversal timing when the electric motor 50 is at a small aperture is set at a time point after the first group blades 11 and 12 substantially reach the first group pinhole position. Once, the cam type ratchet tooth row 33 of the drive ring 40
It is possible to prevent an accident in which the locking lever 35, which has been unlocked with respect to, again locks the cam type ratchet tooth row 33 with the ratchet claw portion 35a.

In this case, the reverse → forward / reverse timing control for the electric motor 50 at the time of a small aperture is performed by the first group blades 11, 1
It is also possible to set it at a time after the 2 has returned to the closed position.

Then, during the course of such a process, the output monitoring means 66 causes the exposure calculation circuit 65 to output the forward drive pulse for realizing the second group blade return rotation speed at the time of the small aperture as the calculated value.
It is confirmed whether or not it is output from the sequence control circuit 63, and the confirmation result is output to the sequence control circuit 63 [step 7].

As a result, the drive ring 40 and the diaphragm ring 30 both return to their initial positions, and the first group blades 11 and 12 and the second group blades 21 and 22 also return to their respective closed positions. The state of the camera shutter device returns to the initial state.

Therefore, after this, if the film winding device (not shown) is operated at a timing known per se,
The state of the camera also returns to the initial state and returns to the state in which the next shooting operation is possible.

Even in the case of the exposure operation with the triangular aperture waveform, the exposure operation with the open aperture aperture can be performed at the design stage. In this case, the first group blade 1
Nos. 1 and 12 start the closing operation without delay time as in the case of the trapezoidal aperture waveform described later.

By the way, the basic idea of the present invention is that the first group blade 11, under the exposure condition that the exposure operation or the photographing operation with the aperture opening smaller than the aperture opening Sa should be performed.
12, the closing operation start time point R at the time of a small aperture and the second group blade 2
By appropriately controlling the time difference between the opening operation start time P of the first and second blades 22 and 22, the movement intersection point between the second group blades 21 and 22 during the opening operation and the first group blades 11 and 12 during the closing operation is described above. Based on the idea of setting the appropriate aperture value intersection point, the appropriate aperture value of the triangular aperture waveform adapted to the appropriate EV value at each time and the appropriate shutter time value to be combined therewith are formed. There is something I did.

Therefore, in the illustrated embodiment, a concrete method for realizing such a concept, in other words, a concrete method for obtaining the above-mentioned appropriate aperture value intersection point, is set by the following mechanical time difference setting. It is configured to be achieved by means (method).

A method of setting the appropriate aperture value intersection point in the illustrated embodiment will be described below assuming a camera having an open aperture value of F2.5.

(A) In the case of the exposure operation with a small aperture opening (for example, F11), the position of the second timing pin 43 at the time when the second group blades 21, 22 are positioned at the opening operation start point P. The angular interval between the locking lever 35 and the position of the second timing cam surface 35b (ie, the first timing cam surface 35b).
And the angular interval between the second timing pins 42 and 43) is set small.

That is, the position of the first timing pin 42 when the second group blades 21 and 22 are located at the opening operation start time point P, and the second timing pin 43 contacts the second timing cam surface 35b, Ratchet claw portion 35a for the cam type ratchet tooth row 33 of the aperture ring 30
In anticipation (sandwiching) of the position where the locking of the drive ring is released, an angular interval (hereinafter,
“Unlocking angular interval”) is set to an angular interval corresponding to a small aperture opening.

When the lock release angular interval is set in this way, the drive ring 40 is set to the first group blades 11 and 12 at that time.
In the process of returning from the position corresponding to the first group blade excessive opening position S1 in the counterclockwise direction toward the second group blade opening end position at the time of the small aperture through the initial position, the second timing pin 43 can be brought into contact with the second timing cam surface 35b earlier, and as a result, the ratchet pawl portion 35a of the aperture ring 30 with respect to the cam type ratchet tooth row 33 is formed.
It is possible to early execute the lock release operation.

Therefore, with this configuration, in FIG. 6, the time difference between the opening operation start time point P of the second group blades 21 and 22 and the closing operation start time point R of the first group blades 11 and 12 at the time of the small aperture stop. Is shortened, and the second group blade 21 is being opened,
22 and the first group blades 11 and 12 in the closing operation can be crossed at an appropriate aperture value crossing point corresponding to a small aperture opening, and a target aperture opening suitable for, for example, F11 can be realized. Because you can.

(B) In the case of an exposure operation with a diaphragm aperture of an intermediate size (for example, F5.6), the second group blades 21, 2
The lock release angular interval when 2 is located at the opening operation start time point P is set to be larger than the lock release angular interval in the case of the exposure operation with the small aperture opening described above.

When the lock release angular interval is set in this way, the drive ring 40 is set to the first group blades 11 and 12 at that time.
The cam-type ratchet in the process of returning from the position corresponding to the excessive opening position S1 of the first group blade toward the initial position and then the counterclockwise direction toward the ending position of the second group blade opening at the time of small aperture. It is possible to set the unlocking time of the ratchet pawl portion 35a with respect to the tooth row 33 later than the unlocking time with respect to the case of the small aperture opening described above.

Therefore, with this configuration, the time difference between the opening operation start time point P of the second group blades 21 and 22 and the closing operation start time point R of the first group blades 11 and 12 at the time of the small aperture at this time is calculated as follows. It is possible to make it longer than the time difference in the case of an exposure operation with a small aperture opening, and at this time, the appropriate aperture value intersection point between the second group blades 21 and 22 and the first group blades 11 and 12 is set to a small aperture opening. It is possible to set the aperture level closer to the aperture opening Sa than the proper aperture value intersection point at.

Therefore, at this time, the opening operation start point P
If the time difference between the closing operation start time R at the time of the small aperture and the closing operation start time R is properly set with the reference position of the basic cam surface of the cam type ratchet tooth row 33 as a reference, it corresponds to the aperture opening of an intermediate size. It becomes possible to intersect at the appropriate aperture value intersection point, and it is possible to realize a target aperture aperture that conforms to, for example, F5.6. The setting of the reference position of the basic cam surface will be described later.

(C) Large aperture opening (eg F2.8)
In the case of the exposure operation in the case of the exposure operation in the case of the exposure operation with the intermediate aperture described above, the lock release angular interval when the second group blades 21 and 22 are positioned at the opening operation start time point P is set. Set larger than the angle interval.

When the unlocking angular interval is set in this way, the drive ring 40 passes from the position corresponding to the first group blade over-opening position S1 of the first group blades 11 and 12 through the initial position to the small aperture at that time. When the stop opening of the ratchet pawl portion 35a with respect to the cam type ratchet tooth row 33 in the process of rotating counterclockwise toward the second group blade opening end position and returning, It is possible to set the time even later than when the lock is released.

Therefore, with this structure, the opening operation start point P of the second group blades 21, 22 and the first group blade 11,
The time difference from the closing operation start time point R at the time of the small aperture of 12 can be made longer than the time difference in the case of the exposure operation at the aperture opening of the intermediate size, and at this time, the second group blades 21, 22. The appropriate aperture value intersection point between the first and second group blades 11 and 12 can be set to an aperture level closer to the aperture opening Sa than the appropriate aperture value intersection point in the case of an intermediate aperture size.

Therefore, at this time, the opening operation start point P
If the time difference between the closing operation start time R at the time of the small aperture and the closing operation start time R is set appropriately with reference to the reference position of the basic cam surface of the cam type ratchet tooth row 33, it is possible to correspond to the aperture opening at the large aperture opening. It becomes possible to intersect at the appropriate aperture value intersection point, and it becomes possible to realize a target aperture aperture that conforms to, for example, F2.8.

The reference position of the basic cam surface of the cam type ratchet tooth row 33 in the above (b) and (c) terms is, for example, the position of the first tooth of the cam type ratchet tooth row 33 or, for example, small. It is preferable to set the position or the like determined in comparison with the appropriate aperture value intersection point in the case of the exposure operation in the aperture opening.

Then, based on such a concept, if the lock release angular intervals for other intermediate aperture values (F4 and F8) are set, the exposure operation should be performed with the aperture opening smaller than the aperture opening Sa. All appropriate aperture values (for example, F2.8 to F11) under the conditions can be set by the crossing action of the first group blades 11 and 12 during the closing operation and the second group blades 21 and 22 during the opening operation. It will be possible.

In this case, the accuracy of the proper exposure amount is greatly influenced by the lock release angular interval and the shape of the basic cam surface of the cam type ratchet tooth row 33. Therefore, in the illustrated embodiment, the first timing is used. Pin 42 and second timing pin 43
Are fixedly planted on the drive ring 40, respectively, and further, a cam type ratchet is provided so as to obtain an unlocking angular interval which can be adapted to all appropriate aperture values (for example, F2.8 to F11). The configuration of the basic cam surface of the tooth row 33 is configured to be set precisely.

That is, to explain the basic cam surface of the cam type ratchet tooth row 33, as shown in FIG. 2 as a representative, the shape of the basic cam surface of the cam type ratchet tooth row 33 is
When the amount of rotation of the aperture ring 30 is small, the action of the cam amount is small (meaning that the amount of separation from the reference arc surface is small), and the aperture ring 3
When the turning angle amount of 0 becomes large, the action of the cam amount becomes large as the turning angle amount becomes large (meaning that the amount of separation from the reference circular arc surface becomes large).

Further, the urging force of the urging spring 27 for urging the second group of blades 21, 22 also has a great influence on the accuracy and durability of the proper exposure amount, so the urging force and the structure are designed. First and second timing pin 4
Angle spacing between 2 and 43 and cam type ratchet tooth row 33
It should be properly set in accordance with the shape of the basic cam surface of.

In the illustrated embodiment, the unlocking angular interval is set by the angular interval between the first and second timing pins 42 and 43 and the shape of the basic cam surface of the cam type ratchet tooth row 33. However, it is also possible to configure as follows.

That is, first, the cam type ratchet tooth row 3
3 is formed in an arc surface like a normal ratchet tooth row, and the second timing cam surface 35 of the locking lever 35 is formed.
b is configured as an engagement pin.

Then, instead of the second timing pin 43 , abutment on the second corner portion 40c of the drive ring 40 in a shape similar to the basic cam surface of the cam type ratchet tooth row 33 described above. It is also possible to form a cam surface and use the contact distance between the contact cam surface and the engaging pin of the lock lever 35 to create the lock release angular interval.

[Exposure Operation with Aperture Aperture Sa] In the above-mentioned [Step 3], the determination result from the aperture area determination circuit 64 indicates that the exposure operation under the aperture opening Sa is under the exposure condition. If
In this state, the user operates the second stage stroke of the shutter release operating member.

When operated in this manner, first, the sequence control circuit 63 commands the exposure calculation circuit 65 to execute the calculation of the above-mentioned items (e) to (m) [step 10]. May be performed in step 2].

At the same time, the motor drive control circuit 67 is instructed to rotate the electric motor 50 based on the calculation output from the exposure calculation circuit 65.

In this case, the calculation output from the exposure calculation circuit 65 is the open aperture value (for example, F2.5) and the proper shutter time value combined therewith, so the motor drive control circuit 67 first determines the open aperture value. Exposure calculation circuit 6 to realize the value
The electric motor 50 is driven to rotate in the positive direction from the initial phase with the aperture opening rotation speed output from the motor 5.

Therefore, the electric motor 50 rotates by the aperture opening rotation number from the initial phase, and its positive direction rotational force is output by the output gear 51 as in the case where the exposure operation at the time of the small aperture is to be performed. Drive ring 4 via gear 40a
0, the drive ring 40 is rotated clockwise from the initial position by the aperture opening rotation amount, and at the same time, the diaphragm ring 30 is resisted against the urging force of the urging spring 34.
Rotate clockwise with 0.

At this time, the aperture setting cam groove 31 on the aperture ring 30 has the intermediate transmission pin 18, the first group blade drive lever 15, the first group blade drive pin 17, and the first group blade cam groove 11
the first group blades 11 and 12 from the closed position to the first group pinhole position and the aperture opening Sa.
Through the first group blade maximum excess opening position S1 '(the position of the opening level shown by the one-dot chain line in FIG. 8).

During the opening operation of the first group of blades 11 and 12, it is small to keep the second group of blades 21 and 22 in the closed position to prevent the exposure of the film surface. This is similar to the case under the condition that the exposure operation at the time of diaphragming should be performed.

Then, while following such a course, the output monitoring means 66 confirms whether or not the number of forward drive pulses for realizing the aperture opening rotation number is outputted from the exposure calculation circuit 65 as the calculated value. , And outputs the confirmation result to the sequence control circuit 63 [step 11].

In this way, when the drive ring 40 (which is also the diaphragm ring 30) is rotated to the position corresponding to the first group blade maximum excessive opening position S1 'of the first group blades 11 and 12, the sequence control circuit 63 is formed. However, the motor drive control circuit 6
7, the electric motor 50 has a reverse drive pulse number that reverses the rotation direction of the electric motor 50 from the normal direction to the reverse direction at the forward-reverse reversal timing when the aperture is opened, and has a reverse drive pulse number that realizes the aperture opening return rotation speed. Command to rotate.

Therefore, the electric motor 50 reverses at the commanded forward → reverse reverse timing when the aperture is opened, and transmits the rotational force in the reverse direction to the drive ring 40 via the output gear 51 → the gear portion 40a. , Drive ring 40, first
The initial position is returned from the rotation position corresponding to the group blade maximum excessive opening position S1 '.

At this time, the aperture ring 30 and the drive ring 4 are also
Although it tries to rotate counterclockwise at the same time following the rotation of 0 in the counterclockwise direction, at this time, as in the case where the exposure operation at the time of the small aperture is to be performed, the aperture ring 30
Is rotated to the N tooth position, the ratchet pawl portion 35a of the locking lever 35 is brought into contact with the specific tooth of the Nth tooth of the cam type ratchet tooth row 33 of the aperture ring 30 by the urging force of the urging spring 37. It bites in and forcibly blocks the counterclockwise rotation of the aperture ring 30.

FIG. 7 shows the state at this time. That is, the locking lever 35 is located at the solid line position to lock the aperture ring 30 at the rotation position (N tooth position) corresponding to the first group blade maximum over-opening position S1 ', and the first group blade 11, 1
2 has opened to the first group blade maximum over-open position S1 ', and only the drive ring 40 is about to start rotating counterclockwise toward its initial position.

While the first group blades 11 and 12 are open from the closed position to the first group blade maximum over-open position S1 ',
Blocking the exposure of the film surface by keeping the group blades 21 and 22 in the closed position is the same as in the case where the exposure operation at the time of the small aperture is to be performed.

Now, the drive ring 40 is the first group blade 1
When the rotational position corresponding to the first group blade maximum excessive opening position S1 'of Nos. 1 and 12 is returned to the initial position, the sequence control circuit 63 instructs the motor drive control circuit 67 to continue to the second group blade. The electric motor 50 is instructed to rotate further with the number of reverse driving pulses that realizes the rotation speed that realizes the aperture opening.

Therefore, the electric motor 50 rotates as instructed and applies the rotational force in the opposite direction to the output gear 51.
→ Transmitted to the drive ring 40 via the gear portion 40a, the drive ring 40 is further rotated counterclockwise from the initial position to the rotation position corresponding to the second group blade aperture opening realizing position S1 '.

Therefore, the drive ring 40 simultaneously rotates the first timing pin 42 in the counterclockwise direction in the course of its rotation, so that the first timing pin 42 and the second group blade drive lever 2 are rotated.
5, the second group blade drive lever 25 is rotated counterclockwise around the pivot 26 against the urging force of the urging spring 27 of the second group blade drive lever 25 ( The second group blades 21 and 22 from the closed position to the second position.
Second through the group pinhole position and aperture opening Sa
The group blade aperture opening is opened to the position S1 '.

On the other hand, in the turning process of the drive ring 40 at this time, the second timing pin 43 on the drive ring 40 is also turned counterclockwise at the same time, but the turning amount of the drive ring 40 at this time is as follows. Since the second timing pin 43 is preset so as not to contact the second timing cam surface 35b of the locking lever 35, the engagement of the locking lever 35 with respect to a specific tooth of the Nth tooth of the cam-type ratchet tooth row 33. The stopped state will still be maintained.

As a result, the first group blade maximum excess opening position S
The first group blades 11 and 12 that are open to 1'will continue to be held in the open position even after the drive ring 40 returns to the initial position.

At this time, when the second group blades 21 and 22 are opened to the second group pinhole position, the opening areas (of the first group blades 11 and 12 already opened to the first group blade maximum excessive opening position S1 ') ( Depending on the exposure conditions, the photographing light begins to enter the film surface through the aperture opening Sa), and the aperture opening Sa
When the exposure is performed, the exposure operation is started.

Then, during the course of such a process, the output monitoring means 66 outputs the reverse driving pulse number for realizing the second group blade aperture opening realizing rotational speed from the exposure calculating circuit 65 according to the calculated value. Whether or not it is confirmed is output, and the confirmation result is output to the sequence control circuit 63 [step 12].

When the second group blades 21 and 22 start the opening operation from the closed position, the sequence control circuit 63 further instructs the motor drive control circuit 67 to have the first group closing timing when the aperture is opened. A command is issued to drive the electric motor 50 to rotate in the opposite direction.

Therefore, the electric motor 50 is further rotated in the opposite direction by the second group blade maximum opening rotation number from the phase in which the second group blade aperture opening realization rotation number is rotated, and the reverse direction rotational force is applied to the output gear 51. → Transmitted to the drive ring 40 via the gear portion 40a, and the ring 40 is further rotated counterclockwise. The amount of rotation of the drive ring 40 at this time is, as described above, sufficient to rotate the aperture ring 30 by an angle corresponding to one tooth of the cam-type ratchet tooth row 33.

When the drive ring 40 is rotated counterclockwise from the position where the second group blade aperture opening is realized, the second timing pin 43 comes into contact with the second timing cam surface 35b of the locking lever 35 to lock it. The lever 35 is pushed counterclockwise around the pivot 36 to release the locking action of the ratchet pawl portion 35a with respect to the specific tooth of the Nth tooth of the cam type ratchet tooth row 33.

Therefore, the aperture ring 3 which is unlocked
0 is the first group blade 11, due to the urging force of the urging spring 34,
From the position corresponding to the first excessive maximum opening position S1 'of the first group blade 12 of the first group blade, the aperture ring 30 is passed past its initial position.
The one-way interlocking part 32 is rotated counterclockwise to a position where the one-way interlocking part 32 comes into contact with the one-way interlocking pin 41 on the drive ring 40.

At this time, the aperture setting cam groove 31 on the aperture ring 30 is also displaced counterclockwise together with the aperture ring 30,
The first group blade driving lever 15, the first group blade driving pin 17,
The movement is performed by the first group blade 1 through the intermediate transmission pin 18.
As shown in FIG. 8, the first group blades 11 and 12 start the closing operation at the closing operation start time point R'at the time of the open aperture, and the first group blade maximum excessive opening position S1 'as shown in FIG. To the closed position via the first group pinhole position.

In this case, when the first group blades 11 and 12 are closed to the first group pinhole position, the photographing light directed to the film surface is blocked by the first group blades 11 and 12. Even when the second group blades 21 and 22 are open to the second group blade maximum excessive opening position S2 ', the second group blade 2
The exposure operation with the open aperture value starting from the second-group pinhole positions of 1 and 22 substantially ends at this point.

That is, the proper EV at this point in time
The proper shutter time value of the trapezoidal aperture waveform related to the value is realized,
A proper exposure amount (area of EV 'shown in FIG. 8) based on the maximum aperture value (aperture aperture Sa) and this proper shutter time value
Will be obtained.

In the process of rotating the drive ring 40 in the counterclockwise direction, the second group blades 21, 22 are moved from the second group blade aperture opening realizing position S1 'to the second group blade maximum excessive opening position S2'. However, since this region is outside the aperture opening Sa, it does not affect the exposure conditions.

Then, while following such a progress, the output monitoring means 66 confirms whether or not the number of forward drive pulses for realizing the drive ring reset rotation speed is output from the exposure operation circuit 65 as the calculated value. Then, the confirmation result is output to the sequence control circuit 63 [step 15].

When the first group blades 11 and 12 are closed to at least the first group pinhole position, the sequence control circuit 63 causes the motor drive control circuit 67 to operate at the reverse → forward / reverse timing when the aperture is opened. The rotation direction of the motor 50 is reversed, and the electric motor 50 is instructed to be rotationally driven with the number of forward drive pulses that realizes the drive ring reset rotation speed.

Therefore, the electric motor 50 is reversed at this reverse → normal reverse timing, and the positive direction rotational force at that time is
The output gear 51 is transmitted to the drive ring 40 through the gear portion 40a, and the drive ring 40 is rotated clockwise from the position corresponding to the second group blade maximum excessive opening position S2 'by the reset rotation amount to the initial position. Return to.

As a result, the second group blade drive lever 25 also
Similar to the case under the condition that the exposure operation at the time of the small aperture is to be performed, the biasing force of the biasing spring 27 returns to its initial position, and in the process of this restoration operation, the second group blade drive pin 28 and the second group blade drive pin 28 The second group blades 21, 22 are returned from the maximum excessive opening position S2 'of the second group blades to the closed position through the cam action with the group blade cam grooves 21a, 22a.

In the illustrated embodiment, the drive ring 40
In the counterclockwise rotation process, the one-way interlocking pin 41 on the drive ring 40 pushes the one-way interlocking portion 32 of the aperture ring 30 in the counterclockwise direction to bring the aperture ring 30 to its initial position at the same time. Will be restored.

As a result, the electric motor 50 returns to the initial phase, the drive ring 40 and the diaphragm ring 30 also return to their initial positions, and the first group blades 11 and 12 and the second group blades 21 and 22 respectively. It will return to the closed position.

When the electric motor 50 returns to the initial phase in this way, the sequence control circuit 63 gives a command to the motor drive control circuit 67 to stop the electric motor 50 at that time. The state of the shutter device for use returns to the initial state.

Therefore, as in the case where the exposure operation at the time of the small aperture is to be performed, if the film winding device is subsequently operated at a timing known per se, the state of the camera also returns to the initial state. It will return to a state where the next shooting operation is possible.

Although the illustrated 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 first embodiment, the electric motor is constructed as a stepping motor, but any other type of electric motor may be used as long as the electric motor can obtain the amount of rotation per unit angle by the number of rotations per unit. It is also possible. It is also possible to use, for example, an electric motor that is additionally provided with a speed control means, and as a result, the amount of rotation per unit angle is obtained by the number of rotations per unit.

[0278]

As described above, according to the first aspect of the present invention, the first group which also serves as the photometric means for photometrically measuring the subject brightness and outputting the photometric data, and the first group which also serves as the aperture blades can be opened and closed. a shutter blade, provided as a separate shutter blade and the first group of shutter blades, and a second group shutter blade diaphragm blades combined capable of performing opening and closing operations, provided as a member that can move in forward and reverse directions, the initial position from performs its first one-way operation by the opening of the first group of shutter blades operation, the operation in the other direction, the closing operation the second group shutter blade opening performs an operation and at least the first group of shutter blades Start and then again the first one direction
A driving member that starts the closing operation of the second group shutter blade by the operation in the same direction and returns to the initial position, and the first group blade from the closed position of the first group shutter blade at the time of photographing. The opening operation to the opening position is performed, and at the time point after the opening operation of the first group shutter blade is started, the second group shutter blade opens from its closed state position to any one of the second group blade opening positions. Let the action
When the second group shutter blade is performing an opening operation from its closed position toward any one of the second group blade opening positions, or an opening operation toward the second group blade opening position. After the end of the above, the first group shutter blade is caused to start the closing operation from any one of the first group blade opening positions, and the first group shutter blade is substantially returned to its closed state position. At a later time, the second
As the can to perform the closing operation from either the second group blade open position to the group shutter blade, the said drive member
From the initial position to the one direction, from the one direction to the other direction
And then drive from the other direction to the one direction again
The shutter blade opening / closing control means for driving and controlling so as to return to the initial position, by the opening operation of the second group shutter blade and the closing operation of the first group shutter blade ,
Since also during triangle opening corrugation configured so as to form a time at least from time to time of the proper shutter speed adapted to the photometric data by the moment of the photometric means during the trapezoidal opening corrugating excellent as follows Produce the effect. (I) The opening / closing operation of the second group shutter blade that also serves as the diaphragm blade that handles the shutter opening operation during exposure and the opening and closing operation of the first group shutter blade that also serves as the diaphragm blade that handles the shutter closing operation Since it is configured to be related by using the mechanical interlocking means of (1), it is possible to stabilize the exposure area formed by the cooperative action of the two sets of shutter blades in the case of the triangular aperture waveform as well as in the case of the trapezoidal aperture waveform. It has an excellent effect that is possible.

As a result, when the invention described in claim 1 is used, it is possible to maintain good exposure accuracy, and to realize a camera shutter device that can greatly improve the performance as a shutter device. We were able to.

(II) In addition, a method of cooperative operation of two sets of shutter blades when performing an exposure operation using an aperture opening smaller than the open aperture opening, and a method of performing an exposure operation using the open aperture opening Since the method of performing the cooperative operation of the two sets of shutter blades is configured by a different method, there is an effect that the cooperative operation of the two sets of shutter blades can be realized over the entire range of subject brightness.

(III) In the illustrated embodiment, in the case of the triangular aperture waveform, the operation start timing of the opening operation of the second group blade responsible for the shutter opening operation and the closing of the first group blade responsible for the shutter closing operation. Since the operation start timing is configured to be set to a desired timing by using the mechanical time difference setting means, for example, as in the technique disclosed in Japanese Patent Laid-Open No. 3-89331, operationally unstable electrical control As compared with the case where the closing operation start timing is set by using other means, the timing setting accuracy can be set with high accuracy.

Also in the case of the trapezoidal opening waveform, the start timing of the closing operation of the first group blade is set mechanically by utilizing the excessive opening operation of the latter stage of the second group blade which is configured in two stages. With this configuration, similarly to the case of the triangular aperture waveform, there is an effect that the timing setting accuracy can be set with high accuracy, as compared with the case where the closing operation start timing is set by using an electrically controlling means.

(IV) Further, in the illustrated embodiment, the mechanical time difference setting means is provided with the drive ring when the first timing pin on the drive ring contacts the first timing cam surface of the second group blade drive lever. The time-series interval (time difference) between the contact point of the second timing pin and the second timing cam surface of the locking lever is set by using a mechanical or mechanical method. When the two timing pins are set by using a fixed angular interval on a single member (drive ring), there is no "positional shift" or "timing shift" between the two timing pins. Therefore, there is an effect that more accurate timing control becomes possible.

(V) Regardless of whether the triangular aperture waveform or the trapezoidal aperture waveform is used, a desired aperture opening (aperture with an exposure condition of aperture) is set at the position after the start of the closing operation of the first group blade in charge of the shutter closing operation. Since the opening is formed, it is possible to increase the closing operation speed in the closing start region of the first group blade to make the closing start curve steep.

As a result, there is no flat portion in the closing operation curve of the first group blade, and there is an effect that it is possible to further increase the shutter speed.

(VI) Further, when it is carried out in the manner as shown in the illustrated embodiment, all the operations of the camera shutter device can be performed by using one electric motor.
For example, another amount of electricity represented by an electromagnetic magnet
For example, it is not necessary to use the mechanical quantity conversion means as an auxiliary, and compared with the conventional shutter device of this type, in terms of circuit configuration
It is possible to obtain an effect of being significantly advantageous in terms of installation space and manufacturing cost.

(VII) Further, as in the illustrated embodiment,
When the shutter device for a camera is configured to perform all operations using one electric motor, the stepwise unit rotational speed of the electric motor is set to the driven-side rotating member (in the illustrated example, the drive ring and / or (Or equivalent to a diaphragm ring) is advantageous when set to the same angle as the stepwise unit rotation angle (or an integer multiple thereof), and when set in this way, the rotation and driven of the electric motor It is possible to obtain an effect that the rotation of the side rotation member can be easily synchronized.

On the other hand, in the invention described in claim 7, for example, a rotating member which rotates in forward and reverse directions (a diaphragm ring in the illustrated example).
, Using the ratchet claw portion (in the illustrated example) of the locking lever, for example, when locking the ratchet tooth row on the locked side in advance in the position after the forward rotation, According to the turning angle of the turning member from the reference position, it is formed on a virtual cam surface of a shape that gradually goes away from a virtual arc surface set in advance as a reference surface in accordance with a predetermined rate of change. Thus, the moving position or the moving posture of the locking lever is changed according to the turning angle of the turning member from the reference position. One direction with a cam action in which the reverse direction rotation start timing when rotating in the reverse direction from the position after movement can be changed by a mechanical cam action according to the rotation angle of the rotating member. A rotation locking mechanism can be realized.

When such a one-way rotation locking mechanism is applied to the diaphragm member (diaphragm ring in the illustrated example) of the camera shutter device, the one-way rotation locking mechanism creates a reverse rotation. By the start timing and the angular spacing between the two timing pins described above, at least
It is possible to set the start timing of the closing operation of the first group blade that realizes the appropriate EV value at each time.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the configuration of an embodiment of a camera shutter device according to the present invention.

FIG. 2 is a rear view showing the rear configuration of the exploded perspective configuration diagram of FIG. 1 when viewed from the right side thereof.

FIG. 3 is a block diagram for explaining a configuration of an electrical control unit that controls the camera shutter device of FIG.

4 is a flowchart for explaining the operation or action of the camera shutter device of FIG.
It is a flow chart when the pitch angle per tooth is set to the same angle as the unit step angle that constitutes the amount of rotation of the drive ring.

FIG. 5 is a plane movement showing a state in which the aperture ring and the pair of first group blades are each held in the excessively open position F ′, and only the drive ring is about to start rotating counterclockwise toward its initial position. It is a figure.

FIG. 6 is an exposure operation diagram showing a triangular aperture waveform when performing an exposure operation with an aperture aperture smaller than the aperture aperture aperture determined by the aperture.

FIG. 7 is a plane motion diagram showing a state in which a pair of second group blades opens from the initial position toward the position of the maximum opening.

FIG. 8 is an exposure operation diagram showing a trapezoidal aperture waveform when performing an exposure operation with an open diaphragm aperture determined by an aperture.

9 is an aperture waveform comparison diagram showing a performance comparison between a triangular aperture waveform in the camera shutter device of the present invention shown in FIG. 1 and a triangular aperture waveform in a conventional shutter device using a pair of aperture blades / shutter blades. is there.

FIG. 10 is a diaphragm-shutter opening waveform diagram for explaining problems caused by changes in the opening timing and opening speed of the shutter blades that occur in the conventional camera shutter device.

FIG. 11 is a diaphragm-shutter opening waveform chart for explaining a flat portion of the diaphragm-shutter opening waveform generated at the start of the closing operation of the shutter blades in the conventional camera shutter device.

[Explanation of symbols]

1 substrate 1a aperture 2 First restricted circular groove 3 2nd limited circular arc groove 4 blade group restraint plate 4a Shooting light passage hole 5 First corresponding circular groove 6 Second compatible circular groove 10 First-group shutter blade means (first-group blade means) 11, 12 First group blade 11a, 12a 1st group blade cam groove 15 First group blade drive lever 17 First group blade drive pin 18 Intermediate transmission pin 20 Second-group shutter blade means (second-group blade means) 21, 22 Second group blade 21a, 22a 2nd group blade cam groove 25 Second group blade drive lever 25a First timing cam surface 27 biasing spring 28 Second group blade drive pin 30 aperture ring 31 Aperture setting cam groove 32 One-way interlocking part 33 Cam type ratchet teeth 34 Biasing spring 35 Locking lever 35a ratchet claw 35b Second timing cam surface 37 Biasing spring 40 drive ring 40a gear part 40b first corner 40c Second corner 41 One-way interlocking pin 42 First Timing Pin 43 Second Timing Pin 50 Electric motor (stepping motor) 51 output gear 52 Intermediate gear 52a large diameter gear 52b small diameter gear 60 electrical control means 61 Photometric circuit 62 CPU 63 Sequence control circuit 64 Opening area judgment circuit 65 Exposure calculation circuit 66 Output monitoring means 67 Motor drive control circuit

Claims (7)

(57) [Claims] 1. A photometric means for photometrically measuring the subject brightness at each moment and outputting photometric data, a first group shutter blade that also serves as an aperture blade, and a shutter separate from the first group shutter blade. The second group shutter blade is provided as a blade and can also be used for opening and closing operations, and the second group shutter blade is provided as a member that can move in forward and reverse directions .
Al performed their first one-way operation by the opening of the first group of shutter blades operation, the operation in the other direction, performs the opening operation of the second group shutter blade and at least the first
To start the closing operation of the group shutter blade, further, again before
Both serial and the first one-way driving member you return to the initial position to start the closing operation of the second group of shutter blades by the same direction of the operation, at the time of shooting, from its closed state position to the first group of shutter blades The opening operation to the first group blade opening position is performed, and at the time point after the start of the opening operation of the first group shutter blade,
The second group shutter blade is caused to perform an opening operation from the closed state position to any one of the second group blade opening positions, and the second group shutter blade is opened from the closed state position to any one of the second group blades. At the time of the process of performing the opening operation toward the position or after the end of the opening operation toward the second group blade opening position, the first group shutter blade is provided with one of the first group shutter blades. At the time point after the closing operation from the group blade opening position is started and the first group shutter blade is substantially returned to the closed position, the second group shutter blade is opened to the second group blade opening. The driving member is moved from the initial position to the closing position so that the closing operation can be performed from the position.
In one direction, from the one direction to the other direction, and the other
Drive again in one direction to return to the initial position
Comprising a shutter blade opening and closing control means for driving and controlling so as to, by the closing operation of the operation as the first group of shutter blades open in the second group shutter blade, or at triangular openings waveform formation base <br/> A shutter device for a camera, which is configured so as to be able to form at least a proper shutter time that is suitable for photometric data by the photometric device at each time when a shaped aperture waveform is formed. 2. A proper aperture opening adapted to the subject brightness at any time, including a position capable of realizing the open aperture opening, in any one of the first group blade opening positions of the first group shutter blades. A plurality of preset first group blade over-opening positions are set beyond the position, and the open stop aperture is realized in any one of the second group blade opening positions of the second group shutter blades. It is configured to set a plurality of second group blade over-opening positions set in advance beyond the respective proper aperture opening positions suitable for the subject brightness at each time including a possible position, and from the closed state position, The second group shutter blade in the middle of performing the opening operation toward the second group blade excessive opening position related to the second group blade opening position from time to time, and the first group related to the first group blade opening position from time to time. Feather Wherein the middle performs an operation to close toward its closed state position from the over - open position first
The position of the movement intersection point where the group shutter blades intersect with each other in the process of performing the mutual operation, the opening operation start time when the second group shutter blade opens from the closed state position, and the first group shutter blade It is configured such that it is set as a position depending on a time series interval between the first group blade excessive opening position and the closing operation start time point when closing, and the time series between these two operation start time points. By setting the interval as a plurality of interval values suitable for the photometric data at each time, the position of the crossing point of the movement of the second group shutter blade and the first group shutter blade is determined by the photometric data at each time. Is configured so as to substantially coincide with the position of the aperture level at which each of the appropriate aperture apertures that conforms to the above is obtained, and this enables the photometry at each time when the triangular aperture waveform is formed. 2. The camera shutter according to claim 1, wherein the shutter aperture for a camera including the open aperture opening and the appropriate shutter time at that time, which are adapted to the camera, can be formed. apparatus. 3. A first group blade opening position of the first group shutter blade is set as a position at which the open diaphragm aperture can be realized.
Alternatively, it is configured such that it can be set as a preset opening position at a position of an opening level exceeding this position, and the second group blade opening position of the second group shutter blade is set to the first group shutter blade first position. As a two-stage open position, a front-stage open position set at a position of an opening level substantially the same as the first-group blade open position and a rear-stage open position preset at a position of an opening level exceeding the front-stage open position. The second group shutter blade is configured to be set, and when the second group shutter blade is opened to the front stage open position, the first group shutter blade already opened to the first group blade open position The first group shutter blade is configured to be held at the first group blade opening position for a predetermined delay time so as to realize a trapezoidal aperture waveform suitable for data, and the first group shutter blade is configured to hold the first group blade blade. When the second group shutter blades are opened to the open position and the second group shutter blades are opened to the front stage open position, the second group shutter blades are moved from the front stage open position to the rear stage open position at the time when the respective delay times substantially elapse. The first group shutter blade is configured to start the closing operation by the opening operation at this time, and the opening operation of the second group shutter blade when the second group shutter blade is opened from the closed state position to the pre-stage opening position is performed. The shutter opening operation is performed when the trapezoidal aperture waveform is formed in conformity with the photometric data at each time, and the first group shutter blade is opened in the first group blade opening position or provided in the camera. With an aperture opening, it is also an appropriate stop opening when forming a trapezoidal opening waveform that is suitable for the photometric data at each time. The shutter closing operation at the time of forming the trapezoidal opening waveform is performed by the closing operation when the first group shutter blade is closed from the first group blade open position to the closed state position after the delay time substantially elapses. Accordingly, it is configured such that the open diaphragm aperture and the proper shutter time at that time can be formed in conformity with the photometric data at each time when the trapezoidal aperture waveform is formed. A shutter device for a camera according to item 1 or 2. 4. An electric motor capable of rotating in the forward and reverse directions is provided, and the driving member can be driven by utilizing the rotational driving force of the electric motor. The shutter device for a camera described in any one of 3 above. 5. The shutter device for a camera according to claim 1, wherein the driving member is composed of a single member. 6. The drive member is configured as a rotary drive member that rotates in forward and reverse directions, and the rotary drive member integrally rotates in the same direction only when the rotary drive member rotates in the forward direction. When the rotation driving member is rotated in the opposite direction, the interlocking with the rotation driving member is released, and the forced rotation causes the first group shutter blade to move. A driven side rotating member that can be opened from a closed state position to any one of the first group blade opening positions is provided, and the rotation driving member is integrated with the driven side rotating member, and the first group shutter blade is At this time, when the driven-side rotation member is rotated in the positive direction by each rotation amount corresponding to each rotation amount that can be opened from the closed state position to each first group blade opening position related to the photometric data at each time, Each position after positive rotation of Is provided with a one-way rotation locking mechanism configured to be capable of being engaged and disengaged in a stepwise manner. Furthermore, a locked structure that can be locked stepwise by this one-way rotation locking mechanism is provided. A stepwise unit turning angle of the driven-side turning member, which is provided on the driven-side turning member side and per one locking step by the one-way turning locking mechanism, and a forward direction of the turning drive member. And the stepwise unit rotation angle are set to the same angle or an integer multiple thereof, and by setting in this way, the one-way rotation at the time when an appropriate diaphragm aperture is formed at each time. 6. The camera according to claim 5, wherein a half-tooth shift phenomenon is prevented from occurring between the locking mechanism and the locked structure of the driven-side rotating member. Shutter device. 7. One direction having a rotating member having a ratchet tooth row in an outer peripheral region, and a ratchet pawl member engaging with the ratchet tooth row of the rotating member so as to be releasably engageable with the ratchet tooth row. In the rotation locking mechanism, for example, a distance from the rotation axis of the rotation member is small in the outer peripheral region of the rotation member according to a rotation angle of the rotation member from a preset reference position. A virtual shape of a shape that gradually goes away from a reference arc surface that is virtually set in advance according to a predetermined rate of change, such that the distance changes from a large distance to a large distance or from a large distance to a small distance. A cam surface is set and the ratchet tooth row is formed along this virtual cam surface, and the movement position of the ratchet pawl member is determined according to the rotation angle of the rotation member from the reference position. No exercise The rotation member can be changed, for example, by a change amount of the movement position or movement posture of the ratchet pawl member based on the cam action of the virtual cam surface according to the rotation angle of the rotation member. A one-way rotation locking mechanism with a cam action, characterized in that a reverse rotation start timing when rotating in a reverse direction from a position after direction rotation is configured.