JP3129536B2 - Camera shutter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shutter, and more particularly to a shutter used for a camera having a large aperture.

[0002]

2. Description of the Related Art Conventionally, in general small cameras and the like,
2. Description of the Related Art There is known a shutter in which a single pulse motor is used as a power source, and the motor is reciprocally driven to open and close a shutter blade. On the other hand, a so-called large-format camera corresponds to the screen size, so that the lens has a large diameter and the aperture diameter serving as an optical path also becomes large. Such a shutter of a camera having a large optical path diameter requires a high traveling speed of the blade because the traveling distance of the shutter blade is long, and a strong spring is provided as a driving force source thereof . That
Therefore, conventionally, had to be charged manually shutter motor, manual charge as its is, since is performed against the strong spring, the charge operation becomes heavy
That was not desirable . But that's it
However, this kind of shutter has a small camera as described above.
Use a small motor that can be mounted on the camera shutter
However, the spring elasticity is stronger than the motor 's driving force .
Therefore, the predetermined charge cannot be performed . for that reason,
To the charge of shutter data to obtain automatically line by the motor
The order, it decided to require the motor of the large amount of force
Ri was achieved, resulting in inconvenience that the outer shape of the motor will be greater Tsu Na.

[0003]

The operation of a shutter having a large aperture for exposing a camera, such as a shutter of a large format camera, is required to be simplified, and a chargeless type shutter device is desired. It became so. In such a case, like a large camera or the small camera described above ,
With a single motor as a driving power source, when you try <br/> the chargeless shutter so as to open and close reciprocating of the shutter blade, it is possible to increase the motor serving as a driving force source, as described above from difficulty Ikoto eventually not be obtained driving force of the predetermined motor, the running speed of the shutter blade becomes slow, fast shutter speed can not be obtained. In particular, near the fully opened position of the shutter blade, it is necessary to cause the motor and the shutter blade to perform the reciprocating switching operation.
However , when the motor and shutter blades are reversed due to inertia, etc.
It will be the speed of the drops significantly faster in this respect
Shutter speed cannot be obtained .
Therefore, it has been difficult to configure the shutter to be a chargeless type with a large format camera or the like.

[0004] The present invention is, in view of such a problem, even in the shutter aperture is great exposure opening, and aims to provide a charge-less type of camera shutter so fast shutter speed can be obtained I do.

[0005]

SUMMARY OF THE INVENTION A camera shutter according to the present invention comprises a pair of blades which are simultaneously rotated in opposite directions to close an exposure opening during an exposure operation.
The shutter blade for closing is simultaneously rotated in the opposite direction to open the opening for exposure during the exposure operation.
The area of each blade is made up of a pair of blades.
Closing the opening for exposure that is larger than each of the blades
The overlapping width in the operating direction in the state
Opening shutter blade that is larger than that of the shutter blade, a first motor that reciprocates the opening shutter blade, and the first motor that opens and closes the exposure opening. And a second motor disposed at a sandwiching position and reciprocating the closing shutter blade. Further, in the camera shutter according to the present invention, the opening shutter blade and the closing shutter blade each have an edge portion which regulates an opening area at the time of an exposure operation, and is formed in a straight line. In the camera shutter according to the present invention, the thickness of the closing shutter blade is different from the thickness of the opening shutter blade.

[0006]

At the time of exposure control, the first motor is driven to open the opening shutter blade which is in a closed state with respect to the exposure opening, and exposure is started. The exposure is completed by driving the motor of (1) and (2) to close the closing shutter blade. Although the closing shutter blade has a relatively small shape and the amount of overlap between the blades in the closed state is not large, there is no risk of light leakage when both the opening and closing shutter blades are in the closed state. In addition, since the opening shutter blades have a large overlapping amount between the blades, a sufficient travel distance for approaching from the start position to the pinhole position at the start of the opening operation until the exposure is started is provided. Since the running speed of the blade can be accelerated and the running speed of the shutter blade after the start of exposure can be increased , a high shutter speed can be obtained.
You . Further, both of the shutter blades for and for closing opening opening
By forming the edge for regulating the area respectively linearly, upon actuation of the closing direction, the principle of scissors, each vane are superimposed with cross without colliding, is closed at a high speed. Further , it is also possible to reduce the weight of the blade by reducing the plate thickness of the blade member, and to increase the opening / closing operation speed of the shutter blade.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS. 1 is a plan view of the shutter before the start of the exposure, FIG. 2 is a plan view of the shutter after the end of the exposure, FIG. 3 is a timing chart of the shutter operation, and FIG. 4 is a diagram showing the relationship between the opening and closing operation of the shutter blades and the approach distance. FIG. 5 is a flowchart showing a general sequence for the shutter operation. In FIGS. 1 and 2, an opening 2 for exposure is formed in the center of the shutter base plate 1. On one side the rear surface of the opening 2 (the plane of the back surface side), an iris motor (moving-magnet motor) or first motor 3 is fixed, the drive pin 3a provided as an output shaft, the rotation range through the long hole 1a bored in the shutter base plate 1 along and protrude to the surface side of the shutter base plate 1. Shout
A pair of opening shutter blades 4 and 5 are provided on the surface of the base plate 1.
Are rotatably supported around the support shafts 6 and 7, respectively.
The drive pin 3a is connected to the pin-slot to form the opening 2
Is opened and closed. The first motor 3 for driving the opening shutter blades 4, 5 is fixed to the permanent magnet rotor when the opening shutter blades 4, 5 are in the closed position.
Due to the attractive force acting between the auxiliary pole provided on the
This state is maintained . The opening shutter blades 4 and 5 have inner edges 4a and 5a that regulate the opening area at the time of exposure, respectively, and are formed linearly (see FIGS. 1 and 2). Therefore, at the time of the closing operation, the edges 4a and 5a cross each other without colliding with each other by the principle of scissors, and are superposed at a high speed. The blades 4 and 5 are in the closed position shown in FIG. 1 so that the overlapping amount (L) in the operating direction of the overlapped area is larger than the overlapping amount (l) of the closing shutter blade described later. The shape and area are formed. Therefore, hereafter, two shutter blades
, The overlap dimension in the working direction passing through the center of the opening 2,
For convenience, the description will be made with the overlap widths L and l.

[0008] Also, on the rear surface of the shutter base plate 1, the first mode
Another iris motor (moving magnet type motor), that is, a second motor 9 is fixed at a position facing the motor 3 with the opening 2 interposed therebetween, and is provided as an output shaft thereof.
The driven pin 9a is a slot 1b of the shutter base plate 1.
And protrudes toward the front surface side of the shutter base plate 1. Shi
On the surface side of the Yatta base plate 1, a pair of closed shutter blades 10, 11 have been pivotally supported around the respective support shaft 12, the driving pin 9a and pin - opening by being slot connected 2 is opened and closed. The second motor 9 for driving the closing shutter blades 10, 11
Is between the permanent magnet rotor and the auxiliary pole provided on the stator side when the closing shutter blades 10 and 11 are in the fully open position.
This state is maintained by the suction force acting on the . The closing shutter blades 10 and 11 are, like the opening shutter blades 4 and 5, the inner edge portions 1 that regulate the opening area.
0a and 11a are formed linearly (see FIG. 1).
The area of the closing shutter blades 10 and 11 is smaller than the area of the opening shutter blades 4 and 5. So
To, overlapping width l at the closing of the closing shutter blades 10 and 11 are formed smaller than the overlapping width L of the opening shutter blade 4,5, thinner than the shutter blades 4,5-opening even thickness formed Have been. This is because the present embodiment is a so-called chargeless type , so that the opening shutter is used before the exposure starts.
This is because the blades 4, 5 always close the opening 2. Of course, a similar overlap width L ≒ l may be used as long as light can be sufficiently shielded or a non-chargeless type. In the exposure control of the shutter, the opening shutter blades 4, 5 are opened from the state shown in FIG. 1 in which the opening shutter blades 4, 5 are in the closed position and the closing shutter blades 10, 11 are in the fully open position. It is started by being done. In addition, the shutter blades 4, 5 and 10, 11 for opening and closing are closed (see FIG. 2) by the closing operation of the shutter blades 10, 11 from the opened position.

Next, the operation of this embodiment will be described with reference to the timing chart shown in FIG. First, in a previous shooting end state, the shutter blades 4,5 and closes the shutter blades 10 and 11 for opens is in both the closed position relative to the opening 2. Then, the main switch is turned on in preparation for the next shooting
Then, the second motor 9 operates and the drive pin 9a turns left . Therefore, in conjunction with the Re its pair of closed shutter blades 10 and 11 are allowed to opening operation, Figure 1 in the fully open state
The state shown in is shown. Then the first motor 3 for exposure
Is activated, the drive pin 3a turns left, and the opening shutter blades 4, 5 start the opening operation. Here, the opening shutter blades 4 and 5 are closed and both the blades 4 and 5 are closed.
5 has a large overlap width L, so that the approach distance a from the closed state to the pinhole (at the start of exposure) a
(See FIG. 4) is relatively long, so that the two blades 4, 5 reach the pinhole in a sufficiently accelerated state, and then start the opening operation toward full opening . In this way, opening shutter blades 4 and 5 by opening operation, the exposure is started.

When a desired exposure time obtained by photometry of a photometry circuit (not shown) elapses, the drive pin 9a of the second motor 9 is turned clockwise from the open position, and accordingly, the closing pin is closed. The shutter blades 10, 11 are started to close. Thereby, the closing shutter blade 1
0 , 11 are edges 10a, 11a crossing near the support shaft
Are for, is engaged that such ku ne heavy collision on the principle of scissors
At high speed to the closed position shown in FIG. Thus, the exposure is completed. Also, the closing shutter blades 10, 1
1, when the closing operation from the fully open position, since even at the maximum opening angle is not sufficiently take the space to begin to shield the opening 2, can not be taken little approach distance b for the acceleration (Fig. 4 ). On the other hand, in the present embodiment, each of the blades 10 and 11 is formed to be lightweight by making the outer shape small and reducing the thickness of the blades .
Even if the approaching distance is short , acceleration can be suitably performed (see FIG. 4). In this manner , the closing shutter blades 10, 11
When the closing operation of the opening 2 is completed, the first motor 3 is operated after a predetermined time has elapsed , the drive pin 3a is turned clockwise, and the opened opening shutter blades 4, 5 are closed. Therefore, in the initial state at the time of the next photographing, the opening shutter blades 4 and 5 and the closing shutter blades 10 and 11 are both in the closed state, so that the closing shutter blades 10 and 11 have small blade shapes and overlap width. Even if the number is small, the problem of the leakage light does not occur. FIG. 5 is a flowchart showing the order of driving the first and second motors 3 and 9 during the above-described shutter operation.

As described above, in this embodiment, the opening operation for exposure control is performed by the first motor 3 and the opening shutter blades 4 and 5, and the closing operation is performed by the second motor 9 and the closing shutter blade 10. , 11, it is possible to suppress a reduction in speed caused by the influence of inertia and the like during the reversal operation of the motor and the shutter blades, to operate the blades at high speed, and to improve the shutter speed. Therefore, the present invention can be sufficiently applied to a shutter of a large-format camera having a large aperture diameter and a large shutter blade, and can be applied to a so-called compact camera. Further, since the first and second motors 3 and 9 are provided at positions opposing each other with the opening 2 interposed therebetween, the first and second motors 3 and 9 may obstruct the arrangement of other shutter components and the like on the arrangement space for the shutter. Less is. Therefore, a plurality of motors 3, 9 and shutter blades 4, 5, 1
Despite the provision of 0 and 11, the enlargement of the mechanism can be suppressed. Also, since the width of the overlapping area of the opening shutter blades 4 and 5 in the closed position is large, the opening shutter blades 4 and 5
, Upon opening operation is accelerated to ten minutes before reaching the pinhole, the shutter speed can be made faster.
Opening and closing shutter blades 4, 5, 10, 11
Are edges 4a, 5a, 10a, 11 that regulate the opening area.
Since “a” is formed in a straight line, no cracking occurs between the pair of shutter blades, and a stable closing operation can be performed. In this regard, in the conventional shutter blades, in order to prevent collision due to crazing , the opening regulating edges are formed in a substantially 「shape so that the tips overlap each other even in the fully opened state. By configuring as in the present embodiment,
This is advantageous in that the shutter blades can be downsized and the moment of inertia can be reduced. Further, when the closing shutter blades 10 and 11 are closed at the end of exposure, each blade 1
Each of the shutter blades 0 and 11 is small, thin, and lightweight, so that the closing operation can be performed quickly even if the approach distance of the blades is not sufficient at the start of the closing operation.
It is possible to increase the speed of the operations of 0 and 11.

In the above-described embodiment, the thickness of the closing shutter blades 10 and 11 is made thinner than that of the opening shutter blades 4 and 5.
May be made thinner. In this embodiment, the iris motor is used as the driving force source. However, another type of motor may be used and drive control may be performed so that the blades are opened and closed, respectively.

[0013]

As described above, in the camera shutter according to the present invention, the opening shutter blade and the closing shutter blade are respectively operated by two motors, so that a large-format camera having a large-diameter exposure opening is provided. However, the shutter can be opened and closed at a high speed, and the shutter speed can be increased.
Further, in the camera shutter according to the present invention, since the two motors are arranged to face each other across the opening, each member can be housed in a relatively small space, and the enlargement of the shutter can be suppressed. In the camera shutter according to the present invention, since the width of the overlapping area of the opening shutter blade in the closed position is relatively large, the blade can be sufficiently accelerated before the opening starts, and the shutter speed is also increased from this point. it can.
Further, in the camera shutter according to the present invention, since the inner edge of each shutter blade is formed in a straight line, each blade does not bite during the closing operation, and the blade shape is different from that of the conventional shutter blade. In comparison, the size can be reduced, the inertia during operation can be reduced, and the shutter speed can be increased. Further, the camera shutter according to the present invention has a thinner closing shutter blade or opening shutter blade, which also contributes to an increase in shutter speed.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the present invention, showing a state before the start of exposure.

FIG. 2 is a plan view of the embodiment, showing a state after exposure is completed .
Have been .

FIG. 3 is a timing chart for explaining the operation of the embodiment .

FIG. 4 is a diagram for explaining a relationship between an opening / closing operation of a shutter blade and a running distance in the embodiment.

FIG. 5 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

2 ... Opening, 3 ... First motor, 4,5 ... Opening shutter blade, 9 ... Second motor, 10, 11 ... Closed shutter blade.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yoshiyuki Ozeki In Copal Co., Ltd., 16-20, Shimura 2 in Itabashi-ku, Tokyo (72) Inventor Koichi Kobayashi Co., Ltd. 16-20 in Shimura 2 in Itabashi-ku, Tokyo ( 72) Inventor Junichi Matsumoto Tokyo Co., Ltd. (72) 16-20, Shimura 2 in Shimura, Itabashi-ku, Tokyo (72) Inventor Tomio Kurosu 16-20 in Copal, Co., Ltd. (72) Toyotoku Sasaki, Tokyo 16-20 Shimura 2 Itabashi-ku Copal Co., Ltd. (56) References JP-A-2-109028 (JP, A) JP-A-61-88756 (JP, A) JP-A-62-156635 (JP, A) Japanese Utility Model Showa 57-199319 (JP, U) Japanese Utility Model Showa 54-42545 (JP, U) Japanese Utility Model Showa 56-137129 (JP, U) Japanese Utility Model Showa 49-17643 (JP, Y1) (58) (Int.Cl. ⁷ , DB name) G03B 9/08-9/5 Four

Claims (3)

(57) [Claims] 1. A pair of blades which are simultaneously rotated in opposite directions and close an exposure opening during an exposure operation.
A shutter blade closing becomes, to open the exposure opening at the time of simultaneous exposure operation is pivoted in the opposite direction
And the area of each of the blades is
Shutter blade is larger than each of the shutter blades and
In the closed state, the overlapping width in the operating direction is
Opening that is larger than the shutter blades for
A first motor for reciprocating the opening shutter blade, a first motor for reciprocating the opening shutter blade, and a second motor for reciprocating the closing shutter blade disposed at a position sandwiching the exposure opening by the first motor. And a motor shutter. 2. The opening shutter blade and the closing shutter blade.
The shutter blade has an edge that regulates the opening area during the exposure operation.
Are formed linearly, respectively.
Item 2. A camera shutter according to Item 1. 3. The thickness of the closing shutter blade and the opening of the closing shutter blade.
Is formed so that the thickness of the shutter blade is different
The camera chassis according to claim 1 or 2, wherein
Tta.