JP3391912B2 - Shutter device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutter device such as a camera.

[0002]

2. Description of the Related Art A high driving speed of shutter blades has various advantages.

For example, in a shutter blade that also serves as an aperture, the shutter aperture can be wide open even when the field is high in brightness. Therefore, in daytime sync photography, the strobe interlocking distance should be extended close to that of normal strobe photography. You can

Further, in the focal plane type shutter, the sync time in flash photography can be shortened.

As a means for driving the shutter blade, an electromagnetic driving means such as a motor or moving coil is known.

[0006]

However, in order to drive the shutter blades at high speed by the electromagnetic driving means such as a motor, a high output is required, and the voltage and current of the battery as the power source and the electromagnetic driving means are required. Due to restrictions such as size, there is a limit to the high speed drive of the shutter blades. An object of the invention according to the present application is to enable high-speed driving of shutter blades under the above restrictions.

[0007]

In order to achieve the above-mentioned object, the first invention according to the present application provides a third position between the third position for prohibiting the exposure and the second position for permitting the exposure. A displaceable shutter member, a driving means that enables the shutter member to be reciprocally driven between a third position and a second position, and a shutter member that is positioned between the third position and the second position. a first position prohibiting <br/> exposure, between the third position
And biasing means acting on said shutter member over only, to bias the shutter member to the second position direction,
When the shutter member is driven from the first position to the third position, the driving unit drives the shutter member from the third position to the second position without stopping at the first position. Characterize.

According to the above construction, the driving force is a resultant force as a cooperative action of the urging means and the driving means to some extent during the opening operation of the shutter member. The opening speed of the shutter member can be increased without increasing the drive power. Also,
Since the urging means acts on the shutter member only in the closed position of the shutter member, the returning operation of the shutter member, that is, the urging force of the urging means does not affect the closing operation of the shutter member that also serves as the diaphragm. There is no adverse effect on the closing characteristics of the shutter member.

A second aspect of the present invention is directed to a first sector device having a first shutter member that moves from a position where exposure is prohibited to a position where exposure is permitted, and an exposure from a position where exposure is permitted. In a shutter device including a second sector device having a second shutter member that moves toward a position that prohibits exposure, at least the second sector device prohibits exposure and a third position that allows exposure. The second shutter member is displaceable between the second shutter member and the third position.
Position between the positions of the drive means for the reciprocatingly driven between said second position, the front Symbol third position and the second position
Urging the the first position for allowing the exposure that location, acts on the second shutter member over between said third position, biases the second shutter member to the second position direction a means, a, when the drive means drives the second shutter member from the first position to the third position, toward the second position from the third position, the first It is characterized by being driven without stopping at the position.

According to the above construction, when the shutter member of the second sector device is being closed, the driving force is a resultant force as a cooperative action of the urging means and the driving means to some extent, for example, a motor or the like. Even if the driving device such as a small motor is used, the opening speed of the shutter member can be increased without increasing the size of the driving means or the driving power. Further, since the urging means acts on the shutter member only in the open position of the shutter member, the returning operation of the shutter member of the second sector device, that is, the urging force by the urging means causes the opening of the shutter member that also serves as the aperture. There is no influence on the operation and no adverse influence on the opening characteristic of the shutter member.

According to a third aspect of the present invention, the urging means has a structure in which the urging means is formed of an elastic member.

According to the above structure, the structure for urging only between the first position and the third position is simple and inexpensive.

A specific construction of the urging means for achieving the object of the present invention is, as described in claim 4, in claim 3, the elastic member is formed by a torsion spring.

According to the above construction, the biasing force of the torsion spring is added to the driving force of the driving means with a certain characteristic over a certain stroke between the first position and the third position of the shutter member. Therefore, a high driving speed can be reached even in a small driving area.

As a concrete constitution of the biasing means for realizing the object of the present invention, as described in claim 5, in claim 1 or 2, the biasing means is a magnetic biasing means. Characterize.

According to the above construction, since there is no mechanical contact load on the biasing means, only a constant force is exerted by the action of only the magnetic force over the constant stroke between the first position and the third position. With the above characteristic, it is added to the driving force of the driving means, and the high driving speed can be reliably reached even in a small driving region.

[0017]

【Example】

(First Embodiment) FIGS. 1 to 19 show a first embodiment of the present invention, and FIG. 1 is a perspective view showing the relationship of components.
FIG. 2 is a sectional view.

Reference numeral 1 is a top base plate, 2 is a first drive ring, and an inner diameter portion 2a is rotatably fitted to a cylindrical portion 1a of the top base plate 1. Drive pins 3 and 4 are fixed to the first drive ring. Reference numeral 5 denotes a first stepping motor as a driving means for reciprocatingly driving first and second shutter blades, which will be described later, and rotates at a predetermined rotation angle as in a known stepping motor. 6 is the first pinion,
It is fixed to the output shaft of the first stepping motor 5, meshes with the gear portion 2b of the first drive ring 2, and transmits the rotational driving force of the first stepping motor 5 to the first drive ring 2.

The first drive ring 2, the drive pins 3 and 4,
Together with the first stepping motor 5, it can also be regarded as a driving means for reciprocally driving a shutter blade described later. Reference numeral 7 denotes a first pressing plate, and the first drive ring 2 is fitted to the cylindrical portion 1a of the upper base plate 1 as shown in FIG.
This is to prevent the first drive ring 2 from being detached by being fixed to i. Reference numeral 8 denotes a first shutter blade, and the drive pin 3 of the first drive ring 2 described above is rotatably fitted into the hole 8a through an elongated hole 1g formed on the outer circumference of the cylindrical portion 1a of the upper base plate 1. . A pin 8b is fixed to the first shutter blade 8, and the pin 8b is slidably fitted in the cam groove 1b of the upper base plate 1. Reference numeral 9 is a second shutter blade, and the drive pin 4 of the first drive ring 2 is rotatably fitted into the hole 9a through the elongated hole 1h formed on the outer periphery of the cylindrical portion 1a of the upper base plate 1. . A pin 9b is fixed to the second shutter blade 9, and the pin 9b is slidably fitted in the cam groove 1c of the upper base plate 1.

The reference numeral 10 has an opening 10a at the center thereof, and is attached to the lower portion of the upper base plate 1 with a gap between the upper base plate 1 and the first shutter blade 8 and the second shutter blade 9 held in the plane direction. It is a blade presser plate.

The dowels 1f, 1d, 1e of the upper base plate 1
Is a projecting portion for providing the gap between the upper base plate 1 and the blade pressing plate 10.

11 is a base plate, 12 is a second drive ring,
An inner diameter portion 12a is rotatably fitted to a cylindrical portion 11a that projects downward from the center of the base plate 11.

Drive pins 13 and 14 are fixed to the second drive ring 12.

A second stepping motor 15 is a known stepping motor as a driving means for reciprocally driving third and fourth shutter blades, which will be described later, and is a known stepping motor which can be rotated at a predetermined rotation angle. It is a thing.

Reference numeral 16 is a second pinion, which is fixed to the output shaft of the second stepping motor 15 and meshes with the gear portion 12b formed on the outer extending part of the second drive ring 12.
The rotational driving force of the second stepping motor 15 is transmitted to the second driving ring 12.

The second drive ring 12 and the drive pin 1
It can also be regarded as a driving means for reciprocatingly driving the third and fourth shutter blades described later in combination with the third and fourth stepping motors 15 and 15.

Reference numeral 17 denotes a second pressing plate, which is fixed to the lower surface 11i after the second drive ring 12 is fitted into the cylindrical portion 11a as shown in FIG. 2 to prevent the second drive ring 12 from falling off. belongs to.

Reference numeral 18 denotes a third shutter blade, and the drive pin 13 of the second drive ring 12 passes through an elongated hole 11g formed on the outer periphery of the cylindrical portion 11a of the base plate 11 and a hole 18a of the third shutter blade 18. It is rotatably fitted in.
The pin 18b is fixed to the third shutter blade,
The pin 18b is slidably fitted in the cam groove 11b of the base plate 11. Reference numeral 19 denotes a fourth shutter blade, and the drive pin 14 passes through the elongated hole 11h formed on the outer periphery of the cylindrical portion 11a of the base plate 11 and the hole 1 of the fourth shutter blade 19 is formed.
9a is rotatably fitted. 4th shutter blade 1
A pin 19b is fixed to 9 and the pin 19b is slidably fitted in the cam groove 11c of the base plate 11.

The base plate 11 is attached to the lower part of the blade pressing plate 10 so as to maintain a gap between the blade pressing plate 10 and the third shutter blade 18 and the fourth shutter blade 19 in the plane direction. There is. Dowel 1 of base plate 11
Reference numerals 1f, 11d, and 11e are protrusions for providing the above-mentioned space between the blade pressing plate 10.

Reference numeral 20 is a torsion spring as a biasing means for biasing the first drive ring 2 in the direction from the closed state to the open state for the first shutter blade 8 and the second shutter blade 9 only in the stroke described later. Torsion spring 20
Has an inner diameter portion 20a fitted to the dowel 1j of the upper base plate 1, one arm 20c is engaged with the dowel 1l of the upper base plate 1, and the other arm 20c.
b is engageable with the dowel 1k of the upper base plate 1 and the dowel 2c provided on the first drive ring 2.

When the first drive ring 2 is between the position shown in FIG. 3 (initial position described later) and the position rotated right from that position, the arm 20b of the torsion spring 20 is aligned with the dowel 1k of the upper base plate 1. When the first drive ring 2 is engaged and reaches the position where the first drive ring 2 is rotated leftward from the state shown in FIG. 3, the arm 20b of the torsion spring 20 is engaged with the dowel 2c of the first drive ring 2 and the first drive ring 2 is engaged. 2 is given a clockwise (clockwise) bias. Although the right rotation direction of the first drive ring 2 will be described later, the shutter mechanism including the first shutter blade 8 and the second shutter blade 9 is used to expose the film surface from the first position to prohibit the exposure of the film surface. Is a direction of displacing to a second position that allows the.

As means for urging the first drive ring 2 in the above-mentioned direction in the above-mentioned stroke, it is possible to use elastic members such as rubber, tension springs, compression springs, and permanent magnets. Further, the subject to be biased by the biasing means is not limited to the first drive ring 2, but the shutter blades 8 and 9 may be directly biased, or the first pinion 6 may be biased.
May be urged, as long as the shutter blades 8 and 9 are urged in a direction in which the shutter blades 8 and 9 are opened only in a certain stroke in the closed state.

Reference numeral 21 designates a third shutter blade 18 and a fourth shutter blade 19 only in a stroke of the second drive ring 12 which will be described later.
Is a torsion spring as an urging means for urging the valve from the closed state to the open state. The torsion spring 21 has an inner diameter portion 21a fitted to the dowel 11j of the base plate 11, one arm 21c engages with the dowel 11l of the base plate 11, and the other arm 21b has a dowel 11k of the base plate 11 and the second arm 21b.
It is engageable with a dowel 12c provided on the drive ring 12.

When the second drive ring 12 is located between the position shown in FIG. 12 (the initial position described later) and the position rotated right from that position, the arm 21 of the torsion spring 21.
b is engaged with the dowel 11k of the base plate 11, and when the second drive ring 12 reaches the position where the second drive ring 12 is rotated counterclockwise from the state shown in FIG. 12, the arm 21b of the torsion spring 21 is moved to the dowel 12c of the second drive ring 12. Engages with the second drive ring 1
2 is given a clockwise (clockwise) bias. Although the right rotation direction of the second drive ring 12 will be described later, the shutter mechanism including the third shutter blade 18 and the fourth shutter blade 19 exposes the film surface from the first position that allows the exposure of the film surface. Is a direction of displacing to a second position that prohibits.

As means for urging the second drive ring 12 in the above-mentioned direction in the above-mentioned stroke, it is possible to use elastic members such as rubber, tension springs, compression springs, and permanent magnets. Further, the target to be biased by the biasing means is not limited to the second drive ring 12, but may be directly biased to the shutter blades 18 and 19.
The pinion 16 may be biased, as long as the shutter blade is biased in a direction in which it is closed only during a certain stroke in the open state.

FIG. 3 is a top plan view of FIG. 1 seen from above, and FIG. 4 is a sectional view taken along line AA in FIG. In the state shown in FIGS. 3 and 4, the opening 10a of the blade pressing plate 10 through which the optical axis passes is closed by the first shutter blade 8 and the second shutter blade 9, and the exposure to the film surface is prohibited.
And the first drive ring 2 is 3γ (degrees) from the position shown in FIG.
There is a margin to rotate left (right in FIG. 4) only. Hereinafter, this state is referred to as the first state.

From this state, the first stepping motor 5 is driven to drive the first drive ring 2 through the first pinion 6 as shown in FIG.
Drive in the left rotation direction (right rotation direction in FIG. 4). At that time, the arm 20b of the torsion spring 20 engages with the dowel 2c of the first drive ring 2 and the dowel 1 of the upper base plate 1 is engaged.
The engagement with k is removed. And torsion spring 2
0 Figure 3 the first drive ring 2 relative to the first drive ring 2
Is urged in the right rotation direction.

When the rotation angle of the first drive ring 2 for each step drive of the first stepping motor 5 is γ,
The stepping motor 5 drives the first drive ring 2 against the urging force of the torsion spring 20 by three steps, that is, by an angle of 3γ in the leftward rotation direction in FIG. 3. This state is shown in FIGS. It is FIG. 5 that the first drive ring 2 is rotated counterclockwise from FIG.
As seen from A, FIG. 6 shows the first drive ring 2 rotated by 3γ from FIG. 4.

5 and 6, the opening 10a of the blade pressing plate 10 through which the optical axis passes is closed by the first shutter blade 8 and the second shutter blade 9 as in the first state, and the exposure of the film is prohibited. Is ready to go. The position of the first drive ring 2 shown in FIGS. 5 and 6 is formed in a direction opposite to the direction in which the opening described later is formed by the first shutter blade 8 and the second shutter blade 9 and the state in which the exposure to the film is permitted is made. It is in a position driven from the state of 1. The state shown in FIGS. 5 and 6 is called the third state.

From the third state shown in FIGS. 5 and 6, the first stepping motor 5 is driven to rotate the first drive ring 2 through the first pinion 6 clockwise in FIG. 5 and counterclockwise in FIG. To go. At that time, when the first stepping motor 5 is rotated by 3 steps, that is, when the first drive ring 2 is rotated by 3γ degrees, the first drive ring 2, the first shutter blades 8, the second shutter blades 9, the first pinion 6, etc. Since the biasing force of the torsion spring 20 is added to the driving force of the first stepping motor 5 as the driving force for the load, the first driving ring 2, the first shutter blade 8, and the second
The load on the shutter blades 9, the first pinion 6, etc. is sufficiently accelerated during that time, and can reach a much higher speed than in the case where the load is accelerated only by the driving force of the stepping motor 5.

When the first drive ring 2 is rotated clockwise (clockwise rotation) in FIG. 5 and counterclockwise (counterclockwise rotation) in FIG. 6, the first shutter blade 8 and the second shutter blade 9 are pinned. 8b and pin 9b are cam grooves 1c and 1b
It rotates around the optical axis while sliding inside. Then, with the movement of the first drive ring 2 according to the shapes of the cam grooves 1b and 1c, the first shutter blade 8 and the second shutter blade 9 rotate around the holes 8a and 9a, respectively, to form an opening. However, the film surface is displaced so that the film surface can be exposed. FIG. 7 shows a state in which the first stepping motor has four steps, that is, the first drive ring 2 rotates by 4γ degrees, and a pinhole is formed by the first shutter blade 8 and the second shutter blade 9. Then, at the 10th step of the first stepping motor, the opening composed of the first shutter blade 8 and the second shutter blade 9 is in a fully opened state, and this state is shown in FIG.
Shown in.

As described above, the state in which the exposure of the film surface is allowed by the first shutter blade 8 and the second shutter blade 9 is included, that is, the positions of the first shutter blade 8 and the second shutter blade 9 shown in FIG. 7 are included. Open side (Figure 8 side)
The position moved to is called the second position.

In the steps after the state shown in FIG. 8, the first shutter blade 8 and the second shutter blade 9 do not rotate about the holes 8a and 9a while keeping the fully opened state, and the first shutter blade 8 and the second shutter blade 9 are placed at the center of the optical axis. The cam grooves 1b and 1c are configured so that they only rotate together with the drive ring 2. FIG. 9 shows the state of the 12th step, which is the final rotation position of the first drive ring.

FIG. 10 is a graph showing the relationship between the rotation angle θ about the holes 8a, 9a of the first shutter blade 8 and the second shutter blade 9 and the number of steps of the first stepping motor. When θ becomes θ ₁ , the shutter blades 8 and 9 form a pinhole, and when θ becomes θ ₂ , the shutter blades 8 and 9 are fully opened.

The number of steps on the horizontal axis is the third step shown in FIGS.
Is set to 0, and the step of driving from the first position (initial state) to the third position direction is omitted.

In FIG. 10, as described above, the acceleration is accelerated by the driving force of the first stepping motor 5 and the biasing force of the torsion spring 20 during steps 0 to 3, and the subsequent steps are accelerated in subsequent steps.
Is accelerated and decelerated by the driving force of.

FIG. 11 is a graph showing the characteristics of the stepping motors 5 and 15. When a drive electric signal is input so that the rotation speed of the stepping motors 5 and 15 becomes, for example, a, the stepping motors do not respond instantaneously but actually the stepping motors. 5 and 15 show that a certain number of steps is required until the speed a is reached.

In this embodiment, since the shutter is opened in the steps after the third step of the first stepping motor 5, the error of the opening speed of the shutter with respect to the set speed by the drive electric signal is very small. Further, as described above, in the present embodiment, the torsion spring 20 is used during steps 0 to 3.
Since the urging force is added to the driving force of the first stepping motor 5, it is possible to reach a high driving speed even in a small acceleration region, that is, in a small number of steps.

After step 10, even if the first drive ring 2 rotates, the first shutter blade 8 and the second shutter blade 9
Rotates only around the optical axis while keeping the openings by the cam grooves 1b and 1c, and finally stops by rotating further 2 steps, that is, 12γ (angle of 12 steps) from the third position. From the 10th step to the 12th step, the first stepping motor decelerates and stops at the position where the state shown in FIG. 9 is reached. Note that the specific number of steps does not limit the present invention.

Further, as shown in FIG. 8, the shutter blades 8,
After the shutter blades 9 and 9 are fully opened, the shutter blades 8 and 9 are configured so that the amount M of escape from the position of the opening 10a that determines the full opening is small, but the actual final stroke is as shown in FIG.
As shown in FIG. 5, since there are up to the 12th step, there is an advantage that the shutter blades 8 and 9 can be prevented from entering the opening 10a again. The sector device including the first shutter blade 8, the second shutter blade 9, the first drive ring 2, and the first stepping motor 5 described above is referred to as a first sector device.

In the first sector device, the first drive ring 2 is not driven.
When it is located at the initial position which is the moving state, the first position shown in FIG.
In this state, the exposure in which the opening is closed is prohibited .

12 and 14 are bottom plan views of FIG. 1 seen from below, and FIG. 13 is a sectional view taken along line BB in FIG. In the state of FIGS. 12 and 13, the blade pressing plate 1 including the third shutter blade 18 and the fourth shutter blade 19 including the optical axis is provided.
The opening 10a of 0 is formed so that the exposure to the film surface is allowed, and the second drive ring 12 is formed as shown in FIG.
Rotate left by 3γ from the position shown in 2 (right in Fig. 13)
I can afford it. Hereinafter, this state is referred to as the first state.

From this state, the second stepping motor 15
To drive the second drive ring 12 through the second pinion 16
Is the left rotation direction in FIG. 12 (right rotation direction in FIG. 13)
Drive to. At that time, the arm 21b of the torsion spring 21 engages with the dowel 12c of the second drive ring 12, and the engagement with the dowel 11k of the base plate 11 is removed. Then, the torsion spring 21 biases the second drive ring 12 in the clockwise direction in FIG. 12 with respect to the second drive ring 12.

Assuming that the rotation angle of the second drive ring 12 for each step drive of the second stepping motor 15 is γ degrees, the second stepping motor 15 resists the biasing force of the torsion spring 21 and the second drive ring 12 does. Is driven in the left rotation direction in FIG. 12 by 3 steps, that is, by an angle of 3γ degrees. This state is shown in FIGS. From FIG. 12, the second drive ring 12 is rotated counterclockwise as shown in FIG.
Similarly, FIG. 15 shows that the second drive ring 12 is rotated by an angle of 3γ degrees from FIG. 13 as viewed from the section B-B.

FIG. 14 and FIG. 15 show the third state as in the first state.
An opening is formed by the shutter blade 18 and the fourth shutter blade 19, and exposure of the film is allowed. The position of the second drive ring 12 shown in FIGS. 14 and 15 is, however, the second drive ring 12 is closed by the third shutter blade 18 and the fourth shutter blade 19, which will be described later.
It is in a position driven from the first state in the direction opposite to the direction in which the exposure of the film is prohibited. 14 and 15
The state shown in is referred to as a third state.

From the third state shown in FIGS. 14 and 15 to the second state
The stepping motor 15 is driven to drive the second pinion 16
The second drive ring 12 through the
In FIG. 15, it is rotated counterclockwise. At that time, three steps of the second stepping motor 15, that is, 3γ rotation of the second drive ring 12, the second drive ring 12 and the third drive ring 12 rotate.
The driving force for the load of the shutter blade 18, the fourth shutter blade 19, the second pinion 16 and the like includes the driving force of the second stepping motor 15 and the torsion spring 2.
The second drive ring 12, the third shutter blade 18, the fourth shutter blade 19, and the second
The load of the pinion 16 or the like is sufficiently accelerated in the meantime, and can reach a much higher speed than in the case of being accelerated only by the driving force of the second stepping motor 15.

When the second drive ring 12 is rotated clockwise (clockwise rotation) in FIG. 14 and counterclockwise (counterclockwise rotation) in FIG. 15, the third shutter blade 18 and the fourth shutter blade
The shutter blade 19 rotates about the optical axis while the pins 18b and 19b slide in the cam grooves 11c and 11b. Then, depending on the shape of the cam grooves 11b and 11c, the second
With the movement of the drive ring 12, the third shutter blade 18,
The fourth shutter blade 19 rotates about the holes 18a and 19a as well, closes the opening, and is displaced to a state in which exposure on the film surface is prohibited.

Including the state in which the exposure of the film surface is prohibited by the third shutter blade 18 and the fourth shutter blade 19, the closing side (step side after 9 steps)
The position moved to is called the second position. In the subsequent steps, the third shutter blade 18 and the fourth shutter blade 1
The cam grooves 11b and 11c are configured so that 9 does not rotate around the holes 8a and 9a while maintaining the closed state, but only rotates together with the second drive ring 12 around the optical axis.

FIG. 16 shows a third shutter blade 18 and a fourth shutter blade.
6 is a graph showing the relationship between the rotation angle α of the shutter blades 19 around the holes 18a and 19a and the number of steps of the second stepping motor 15. When the rotation angle α is α ₁ , the shutter blades 18 and 19 are Blade presser plate 10
When it enters into the opening 10a and becomes α ₂ , it is in a fully closed state. The number of steps on the horizontal axis is the third step shown in FIGS.
Is set to 0, and the step of driving from the first position (initial state) to the third position direction is omitted.

In FIG. 16, as described above, the acceleration is accelerated by the driving force of the second stepping motor 15 and the biasing force of the torsion spring 21 between the 0th step and the 3rd step, and the subsequent steps are performed by the second stepping motor 15. It is accelerated and decelerated by the driving force.

In this embodiment, the second stepping motor 15
Since the closing of the shutter is started in the steps after the third step, the error that the closing speed of the shutter is very small with respect to the speed set by the drive electric signal is Is the same as. Further, as described above, in this embodiment, the biasing force of the torsion spring 21 is added to the driving force of the second stepping motor 15 from 0 step to 3 steps, so that the high rotation speed is reached even in a small acceleration region, that is, in a small number of steps. be able to.

After 10 steps, even if the second drive ring 12 rotates, the third shutter blade 18 and the fourth shutter blade 19 only rotate around the optical axis while being kept closed by the cam grooves 11b and 11c. Finally, further two steps, that is, 12γ degrees (angle of 12 steps) is rotated from the third position, and then stopped. The second stepping motor 15 decelerates and stops during the 10th to 12th steps. Since the cam grooves 11b and 11c hold the closed state from the 9th step to the 12th step, even if the bouncing occurs at the 12th step which is the final step, the cam grooves 11b and 11c do not reopen.

A sector device including the third shutter blade 18, the fourth shutter blade 19, the second drive ring 12, the second stepping motor 15 and the like is called a second sector device.

The specific number of steps does not limit the present invention. Also, the second sector device is
2 The drive ring 12 is in the initial position which is the non-drive state
If it is the case, the first state shown in FIG. 12 is set, so that the open exposure is permitted . FIG. 17 is a block diagram of an electric circuit used in the present embodiment, 101 is a control circuit which controls the entire sequence including a microcomputer and also includes a memory circuit, and 102 is a first drive circuit for driving the first stepping motor 5. 1 stepping motor drive circuit, 10
Reference numeral 3 is a second stepping motor drive circuit for driving the second stepping motor 15, and reference numeral 104 is a known photometry circuit for photometry of the field brightness. Reference numeral 105 denotes a release switch. When the switch is turned on, the camera is released. Reference numeral 106 is a film feeding motor that drives a known film feeding gear train, 107 is a driver circuit of a film feeding motor that drives the film feeding motor 106, and 108 is a known clock circuit.

The operation of the control circuit 101 will be described below with reference to the flowchart of FIG.

[Step 1] It is determined whether or not a release button (not shown) is pressed to turn on the release switch 105. If it is determined that the release switch 105 is turned on, the process proceeds to step 2. [Step 2] The photometric circuit 104 is operated to measure the brightness of the subject, and step 14 described later is performed according to the measured value.
The timer count-up time T is determined.

[Step 3] The first stepping motor drive circuit 102 is driven to rotate the first stepping motor 5 in the reverse direction, that is, from the position in the first state shown in FIG. 3 to the position in the third state shown in FIG. Start driving in the direction you are heading.

[Step 4] When the position of the first stepping motor 5 is driven by the amount corresponding to the position of the third state shown in FIG. 5 from the position of the first state shown in FIG. Go to 5.

[Step 5] The first stepping motor 5 is stopped via the first stepping motor drive circuit 102. In this case, even if the energization is cut off, the cogging force of the first stepping motor 5 may hold it at that position against the biasing force of the torsion spring 20. The stepping motor 5 is kept energized so as to hold its position.

[Step 6] The second stepping motor drive circuit 103 is driven to drive the second stepping motor 15
Is started in the reverse direction, that is, in the direction from the position of the first state shown in FIG. 12 to the position of the third state shown in FIG.

[Step 7] From the position of the first state shown in FIG. 12 to the position of the third state shown in FIG. 14,
That is, in this embodiment, after driving the second stepping motor 15 for only three steps, the process proceeds to step 8.

[Step 8] The second stepping motor 15 is stopped via the second stepping motor drive circuit 103. In this case, even if the energization is cut off, it may be held against the biasing force of the torsion spring 21 at that position by the cogging force of the stepping motor. However, in order to increase the certainty, the first stepping motor 15 Is left energized to hold its position.

[Step 9] The clock circuit 108 is reset.

[Step 10] Forward rotation of the first stepping motor 5 through the first stepping motor drive circuit 102, that is, a direction from the third state shown in FIG. 5 to the position of the second state shown in FIG. The driving is started at the driving frequency determined in advance.

[Step 11] The clock circuit 108 is started, and the elapsed time from the start of driving the first stepping motor 5 is counted.

[Step 12] The first stepping motor 5 is driven through the first stepping motor driving circuit 102 at a predetermined driving frequency for a predetermined number of steps, that is, 12 steps in this embodiment as shown in FIG. If it is determined that the driving of the predetermined step is completed, the process proceeds to step 13. If it is not completed, the first stepping motor 5 is driven in the predetermined step and step 14 is performed.
Go to.

[Step 13] The first stepping motor 5 is stopped via the first stepping motor drive circuit 102.

[Step 14] It is determined whether or not the count of the clock circuit 108 started in step 11 has reached the time determined in step 2, and if not, the process returns to step 12 to reach it. If yes, step 1
Go to 5.

[Step 15] The second stepping motor 15 is driven through the second stepping motor drive circuit 103.
14 in the normal direction, that is, the second drive ring 12 is rotated clockwise from the third state shown in FIG. 14 to start driving at a predetermined drive frequency in the direction to reach the position of the second state.

[Step 16] The second stepping motor 15 is driven through the second stepping motor drive circuit 103.
Is driven at a predetermined driving frequency for a predetermined number of steps, that is, in the present embodiment, it is determined whether or not the second sector device is fully closed by driving 12 steps, and if the driving of the predetermined step is completed, go to step 17. If not completed, return to step 12.

[Step 17] The second stepping motor 15 is driven through the second stepping motor drive circuit 103.
To stop.

[Step 18] The film feeding motor 106 is driven through the film feeding motor driver 107 to wind the next frame of film.

[Step 19] The driving of the first stepping motor 5 is started at a predetermined driving frequency via the first stepping motor driving circuit 102 so that the first sector device becomes the first state shown in FIG. To do.

[Step 20] When the first stepping motor 5 is driven by a predetermined step through the first stepping motor drive circuit 102, it is confirmed that the first sector device is in the position of the first state shown in FIG. If it is determined that the position is reached, the process proceeds to step 21.

[Step 21] The first stepping motor 5 is stopped via the first stepping motor drive circuit 102.

[Step 22] The second sector device is set to FIG.
The driving of the second stepping motor 15 is started at a predetermined driving frequency via the second stepping motor driving circuit 103 so that the first state shown in FIG.

[Step 23] The second stepping motor 15 is driven through the second stepping motor drive circuit 103.
Is driven for a predetermined number of steps to determine that the second sector device has reached the position of the first state shown in FIG. 12, and if it has reached that position, the routine proceeds to step 24.

[Step 24] The second stepping motor 15 is driven through the second stepping motor drive circuit 103.
To stop.

FIG. 19 is a graph showing the exposure amount exposed to the film surface by the first sector device and the second sector device, and the time determined in step 2 in the above-mentioned flowchart is indicated by T.

The area opened by the first sector device is indicated by a, and the area opened by the second sector device is indicated by b.

The horizontal axis represents the time from the start of driving the first sector device, the number of steps of the first stepping motor and the second stepping motor. In the entire shutter device, the hatched portion is the area where the opening is provided. The exposure amount can be changed by changing the delay time T to change the opening area.

(Second Embodiment) FIG. 20 is a plan view showing a second embodiment and shows a first state similar to that of the first embodiment of the first sector device.

A permanent magnet 22 is an arm 2 of the first drive ring 2.
It is fixed to d. Reference numeral 23 is a permanent magnet fixed to the upper base plate 1, and when the first drive ring 2 is in the third state, the permanent magnet 22 and the permanent magnet 23 face each other at a close distance and face the facing surface 22a. The polarities of 23a are the same and are repulsed by magnetic force. Since this repulsive force is approximately inversely proportional to the square of the mutual distance, the repulsive force is very small at the position shown in FIG. 20, that is, in the second state, and even if a shock is applied to this device, the first drive ring 2 is The clockwise rotation does not depend on the cogging force of the first stepping motor 5.

Further, in the second state in which the distance between the permanent magnets 22 and 23 is increased, the repulsive force is further weakened and the rotational movement of the first drive ring 2 is hardly affected. However, the permanent magnets 22 and 23 have a third
Since the distance between the permanent magnets is short from the position in the state 1 to the position in the first state, the repulsive force is strong, and the same function as that of the torsion spring 20 in the first embodiment is applied to the first drive ring 2. As a biasing means, the biasing means biases only between the first position and the third position.

(Third Embodiment) FIGS. 21 to 24 show a third embodiment.
The example of is shown.

Numerals 401 and 402 are shutter blades that also serve as diaphragms, 403 is a blade pressing plate having an opening 403a having the maximum diaphragm diameter, 404 is a shutter base plate, and 405 is a shaft 4.
Is a drive lever rotatable about 05a as a rotation center,
A drive pin 405b is fixed to one arm, and a dowel capable of engaging with an arm of a torsion spring 407 described later is formed on the other arm. Reference numeral 406 is a known drive device that drives the drive lever 405 to rotate both clockwise and counterclockwise around the shaft 405a as a rotation center, and may be a DC motor, a moving coil, a moving magnet, a stepping motor, or the like.

The shutter blades 401 and 402 have holes 401.
a and 402a are rotatably fitted to fulcrum pins 404a and 404b of the shutter base plate 404, respectively. The drive pin 405 is the long hole 40 of the shutter blades 401 and 402.
1b and 402b are slidably fitted. In the blade pressing plate 403, the shutter blades 401 and 402 are fulcrum pins 4
The shutter base plate 404 is attached to the shutter base plate 404 by a screw (not shown) or adhesive so as to be rotatable about 04a and 404b. The movement of the drive pin 405b in the direction of the arrow E due to the rotation of the drive lever 405 causes the shutter blades 401 and 402 to rotate to form and close the openings.

Reference numeral 407 denotes a torsion spring which fits into a dowel 409c provided on a base plate whose inner diameter portion is not shown. Is configured to urge in the right rotation direction, and the dowel 405c of the drive lever 405, the arm 407a, and the arm 407b can be engaged with each other.

However, in the state shown in FIG. 22, the arm 407a of the torsion spring 407 is the dowel 409a of the main plate (not shown) and the arm 407b is the dowel 409 of the main plate (not shown).
The biasing force of the torsion spring 407 does not directly act on the dowel 405c of the drive lever 405 because they are engaged with the respective b's. This state is the same as the first state of the first sector device in the first embodiment, and the shutter blades 401 and 402 are in a state of prohibiting exposure on the film surface.

By the way, in response to the release of the camera,
The control circuit (not shown) drives the drive device 406 from the state of FIG. 22 to rotate the drive lever 405 counterclockwise. At that time, the dowel 405c of the drive lever 405 is connected to the torsion spring 40.
7 is engaged with one of the arms 407b and receives a force in a direction to rotate the drive lever 405 to the right.
5 rotates the drive lever 405 counterclockwise against the force, and FIG.
Set to the position shown in 3. This state is still a state in which the shutter blades 401 and 402 prohibit the exposure of the film, and is the third state in the first sector apparatus of the first embodiment.

Next, from this state, the drive device 406 rotates the drive lever 405 clockwise. At that time, shutter blade 4
As the force for driving 01, 402, in addition to the driving force of the driving device 406, the arm 407b of the torsion spring 407 is used.
The force acting on the dowel 405c of the drive lever 405 is also added. This arm 407b of the torsion spring 407
23 is added from the state shown in FIG. 23 until the arm 407b of the torsion spring reaches the position where it engages with the dowel 409b as shown in FIG. 22 is accelerated to a much higher speed than that which is accelerated only by the driving force of the driving device 406, and FIG.
24, and is driven toward a second state similar to that in the first sector apparatus of the first embodiment that permits exposure of the film by the shutter blades 401 and 402 shown in FIG. Go. The shutter blades 401 and 402 form a pinhole opening, permitting exposure to the film, and the dowel 405c of the drive lever 405 moves the torsion spring 40 until the fully open position shown in FIG.
7 is engaged with the arm 407a of the torsion spring 40.
7, the drive lever 405 receives an urging force in the left rotation direction, but the drive device 406 rotates the drive lever 405 rightward against the force.

When the time corresponding to the brightness of the field has passed, the rotation of the driving device 406 is reversed, and the driving lever 405 is returned to the state shown in FIG. 22 together with the biasing force of the arm 407a of the torsion spring 407 to complete the exposure operation. .

The third embodiment described above is applied to a shutter device of the type in which one set of shutter blade devices is opened and closed to perform an exposure operation without impairing the spirit of the present invention.

[0104]

According to the first aspect of the invention, since the urging means urges only the closing range of the shutter member in the opening direction, the shutter member is driven to a certain extent during the opening operation. The force is a resultant force as a cooperative action of the urging means and the drive means, and the opening speed of the shutter member can be increased without increasing the size and drive power of the drive means such as a motor. Further, since the urging means acts on the shutter member only in the closed position of the shutter member, the returning operation of the shutter member, that is, the urging force of the urging means has no influence on the closing operation of the shutter member which also serves as the diaphragm. Therefore, there is no adverse effect on the closing characteristic of the shutter member.

According to the second aspect of the present invention, when the shutter member of the second sector device is being closed, the driving force is, to some extent, a resultant force as a cooperative action of the urging means and the driving means. Therefore, the closing speed of the shutter member can be increased even with a small drive device such as a motor without increasing the size of the drive means such as a motor or the drive power. Further, since the urging means acts on the shutter member only in the open position of the shutter member, the returning operation of the shutter member of the second sector device, that is, the urging force by the urging means causes the opening of the shutter member that also serves as the aperture. There is no influence on the operation and no adverse influence on the opening characteristic of the shutter member.

According to the third aspect of the invention, the structure for urging only between the first position and the third position can be obtained simply and at low cost.

According to the fourth aspect of the present invention, the biasing force of the torsion spring has a certain characteristic over the constant stroke between the first position and the third position of the shutter member, and has a certain characteristic. Since it is added to the driving force, it is possible to reliably reach a high rotation speed even with a small number of driving steps.

According to the invention described in claim 5, since there is no mechanical contact load with respect to the urging means, the constant stroke between the first position and the third position is exerted only by the action of the magnetic force. Therefore, only a certain magnetic characteristic is added to the driving force of the driving means, and a high rotation speed can be reliably reached even with a small number of driving steps.

[Brief description of drawings]

FIG. 1 is a perspective view of main components of the first embodiment.

FIG. 2 is a sectional view of FIG.

3 is a top plan view of the first sector device of FIG. 1, showing a first state. FIG.

FIG. 4 is a cross-sectional view taken along the line AA of the first sector device in FIG. 2, showing a first state.

FIG. 5 is a top plan view of the first sector device of the first embodiment,
The 3rd state is shown.

6 is a cross-sectional view taken along the line AA in FIG. 2, showing a third state.

7 is a cross-sectional view taken along the line AA in FIG. 2 and shows a pinhole formed.

8 is a cross-sectional view taken along the line AA in FIG. 2 and shows a fully opened state.

9 is a cross-sectional view taken along the line AA in FIG. 2, showing the final end when fully opened.

FIG. 10 is a graph showing the relationship between the blade rotation angle and the number of steps of the stepping motor in the first sector device of the first embodiment.

FIG. 11 is a characteristic diagram of the stepping motor of the first embodiment.

FIG. 12 is a bottom plan view of the second sector device, showing the first state.

FIG. 13 is a sectional view taken along line BB in FIG. 2 of the second sector device, showing the first state.

FIG. 14 is a bottom plan view of the second sector device of the first embodiment, showing the third state.

15 is a cross-sectional view of the second sector device taken along the line BB in FIG. 2, showing a third state.

FIG. 16 is a graph showing the relationship between the shutter blade rotation angle and the step number of the stepping motor in the first embodiment.

FIG. 17 is a block diagram of an electric circuit of the first embodiment.

FIG. 18 is a flowchart showing the operation of the control circuit of the first embodiment.

FIG. 19 is a graph showing aperture characteristics of the first example.

FIG. 20 is a top plan view of the first sector device of the second embodiment,
The 1st state is shown.

FIG. 21 shows a perspective view of a third embodiment.

FIG. 22 is a plan view of the main part of the third embodiment, showing the first state.

FIG. 23 is a plan view of the main part of the third embodiment, showing a third state.

FIG. 24 is a plan view of a main part of the third embodiment, showing an open state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Top plate 2 ... 1st drive ring 5 ... 1st stepping motor 8 ... 1st shutter blade 9 ... 2nd shutter blade 11 ... Base plate 12 ... 2nd drive ring 15 ... 2nd stepping motor 18 ... 3rd shutter blade 19 ... Fourth shutter blade 20 ... Torsion spring 21 ... Torsion spring

Claims (5)

(57) [Claims] 1. A shutter member displaceable between a third position for prohibiting exposure and a second position for permitting exposure, and the shutter member is disposed between the third position and the second position. a drive means for reciprocally driving a first position to prohibit the exposure located between said third position and said second position, only between the third position <br/> An urging means that acts on the shutter member over time and urges the shutter member in the second position direction, and the drive means moves the shutter member from the first position to the third position. When driven, the shutter device is driven from the third position to the second position without stopping at the first position. 2. A first sector device having a first shutter member that moves from a position where exposure is prohibited to a position where exposure is allowed, and a first sector device that moves from a position where exposure is allowed to a position where exposure is prohibited. A shutter device having a second sector device having a second shutter member for controlling at least the second sector device between a third position for allowing exposure and a second position for prohibiting exposure. in conjunction with the displaceable second shutter member, driving means for the second shutter member to be reciprocally driven between the second position and the third position, before Symbol third a first position for allowing the exposure located between the position and the second position, act on the second shutter member over <br/> only between the third position, the Second
The biasing means for the shutter member to bias the second position direction, have, when the drive means drives the second shutter member from the first position to the third position, the A shutter device that is driven from a third position to the second position without stopping at the first position. 3. The shutter device according to claim 1, wherein the urging means is formed of an elastic member. 4. The shutter device according to claim 3, wherein the elastic member is formed of a torsion spring. 5. The shutter device according to claim 1, wherein the urging means is a magnetic urging means.