JP3500273B2 - Camera shutter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is generally called a lens shutter in which two shutter blades relatively reciprocate to open and close a circular exposure opening during photographing. The present invention relates to a shutter for a camera.

[0002]

2. Description of the Related Art Generally, in this type of shutter, 2
The shutter blades are pivotally attached to the shutter base plate,
It is adapted to reciprocate in conjunction with the reciprocating operation of the opening / closing member. As the drive source of the opening / closing member, there are one that performs both reciprocating operations by spring force, one that performs one operation by a motor and the other operation by a spring, and one that performs both reciprocating operation by a motor. Also, among those in which at least one of the opening / closing members is driven by a motor, there is known one in which the opening / closing member is integrally formed with the rotor of the motor. Further, the connection between the two shutter blades and the opening / closing member is such that elongated holes are formed in each of the shutter blades and the operating pins of the opening / closing member are fitted into them, but in this case, one operating pin is used. There are two types in which the blades are fitted in both of the long holes, and two actuating pins are provided and are fitted in the long holes of different blades.

By the way, in this way, the shutter blade is
Although it is operated by the opening / closing member, there is a tolerance in the fitting between the operating pin and the long hole, so normally, during opening operation of the shutter, opening operation of the opening / closing member and opening operation of the shutter blades are always performed at a predetermined timing. There is a situation in which the shutter blades are not started and the opening operation of the two shutter blades is not started at a predetermined timing. Moreover, the tolerance differs for each manufactured shutter, and the relative positional relationship between the operating pin and the slot changes depending on how the camera is held, so even when shooting a field under the same conditions, An exposure result (unevenness) which is different for each shooting is obtained. Therefore, conventionally, two stop means are provided on the shutter base plate, and when the shutter pin is closed, the operating pin presses the two shutter blades against the stop means, so that the relative positions of the three parties are I was always able to maintain a certain relationship.

In addition, among the shutters in which the opening / closing member is reciprocally operated by a motor, recently, due to cost advantages,
Motors called moving magnet type motors are often used. This motor has an advantage that it is relatively small and consumes less power, but the stop position of the permanent magnet rotor, that is, the stop position of the operating pin becomes unstable when the coil is not energized. There is a problem. Therefore, in this type of shutter, a magnetic member is arranged in a part of the stator, and the rotor is biased in the closing direction by the magnetic attraction force that acts between the rotor and the rotor. The relative position of each of them kept a constant relationship.

[0005]

However, as described above, in order to ensure that the two shutter blades are simultaneously in contact with the respective stop means in the closed state, the positional accuracy of the two stop means is to be improved. However, if the shutter base plate is made of synthetic resin, the mold becomes expensive, and in any case, the cost becomes high. Further, in the case where the moving magnet type motor is used to perform the opening / closing operation, it is necessary to attach a smaller magnetic member to a small stator at an effective position, which is a troublesome work and causes a cost increase. Was there.

Further, although it is an invention different from the gist of the present invention, the relative positional relationship between the opening / closing member and the two shutter blades in the closed position is eventually obtained in a constant manner. The configuration is disclosed in Japanese Patent Laid-Open No. 8-6107. In the case of this structure, the two shutter blades are respectively provided with different springs, but as can be judged from the embodiments of the present invention described later, the shutter blades are mutually separated in a small and narrow space. so as not to affect the operation, it is impossible to make separately apply a spring, dare size of shape of the shutter blade when you try to enable it, thus inviting an increase in size of the outer shape of the shutter There is a problem that it ends up. In addition, coil springs generally have many variations in quality, but the use of two coil springs increases the variation in biasing force, which makes the adjustment of the operating characteristics of the shutter blades troublesome. There is.

The present invention has been made in order to solve such problems, and its purpose is to
Even if there is any fitting tolerance between the elongated hole of the shutter blade that relatively opens and closes the sheet and the operating pin of the opening and closing member, the relative operation between the operating pin and the two shutter blades at the exposure operation start position. It is possible to maintain a constant positional relationship at all times, and when shooting under the same field conditions,
The configuration is so simple that you can always get the same exposure result.
A small and low-cost camera shutter is provided.

[0008]

In order to achieve the above object, a camera shutter of the present invention comprises two main plates having an exposure opening and forming a blade chamber therebetween. , A length that is pivotally attached to either of the two main plates in the blade chamber so that they intersect each other when closed.
It has two shutter blades having a hole and one operating pin fitted in both of the long holes, and the two shutter blades are opposed to each other when reciprocally operated by a driving source during exposure. Opening / closing member that reciprocally operates to open and close the opening, stop means that is provided on one of the base plates and prevents the operation of one shutter blade in the closing direction when the opening is closed, and the other And a spring for biasing the shutter blade to rotate in the closing direction and for bringing the one shutter blade into contact with the stopping means via the operating pin.
Further, in the camera shutter of the present invention, preferably, among the reciprocating operations of the opening / closing member, a drive source for opening operation is a motor and a drive source for closing operation is a spring. Alternatively, the drive source for the reciprocating operation of the opening / closing member is a motor. In that case, preferably, the motor is a moving magnet type motor, and the opening / closing member is
The moving magnet type motor is integrally formed with the rotor.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to the examples shown in FIGS. 1 is a plan view showing a closed state of the shutter blades, and FIG. 2 is a central cross sectional view of FIG. 3 is a plan view of the interior of the blade chamber when the shutter blades are closed, and FIG. 4 is an enlarged view of the main parts of FIG. FIG. 5 is a plan view of the inside of the blade chamber when the shutter blades are fully open.

First, the structure of the embodiment will be described. The shutter base plate 1 and the auxiliary base plate 2 are both made of synthetic resin, and have a circular opening 1 for exposure that allows the field light to pass through at the center.
a and 2a are formed. Both are attached from the side of the auxiliary base plate 2 by two screws 3 and 3 and form a blade chamber therebetween. Two shutter blades 4 and 5 are arranged in the blade chamber, and are pivotally attached to shaft portions 1b and 1c provided on the shutter base plate 1, respectively. However, as is well known, the auxiliary base plate 2 may be pivotally attached. Further, the shaft portion may be provided on the blade side and the hole may be formed on the base plate side. Although not shown, the base plates 1 and 2 are provided with a mounting portion to the camera body,
The shutter base plate 1 is attached to the camera so that the shutter base plate 1 is on the lens side and the auxiliary base plate 2 is on the film side.

A motor M called a moving magnet type motor is attached to the front surface side of the shutter base plate 1. This moving magnet type motor M is
A motor used as a drive source for shutter blades is well known, and a rotor 8 of a permanent magnet is axially supported by an upper frame 6 and a lower frame 7 made of synthetic resin. , 9 are attached to the shutter base plate 1.
As can be seen from FIG. 2, the coil 10 is wound so as to cover the two rotatably supporting portions of the rotor 8, and the coil 10 is wound on the outer side thereof.
A cylindrical yoke 11 is mounted concentrically with the rotor 8. In the motor M, the rotor 8 rotates in the forward direction or the reverse direction according to the direction of the current supplied to the coil 10, and in the normal case, the rotation is performed in the range of 30 to 40 °. Has become.

In this embodiment, the rotary shaft 8a of the rotor 8 is made of synthetic resin, and the opening / closing member 12 is integrally formed with the rotary shaft 8a by molding. And the opening / closing member 12
Although not explicitly shown, there is a portion that projects radially from the rotary shaft 8a, and an operating pin 12a is formed by further extending in a substantially perpendicular direction from the portion. This operating pin 12a
Is inserted into the blade chamber through the arc-shaped hole 1d formed in the shutter base plate 1, and as is apparent from FIGS. 3 to 5, the long holes 4a and 5 formed in the shutter blades 4 and 5.
It is fitted to a. Therefore, in FIG. 1, when the rotor 8 rotates counterclockwise, the operation pins 12a cause the shutter blades 4 and 5 to open the openings 1a and 2a, and thereafter,
When the rotor 8 rotates clockwise, the shutter blades 4, 5
Closes the openings 1a and 2a.

The shutter base plate 1 is provided with a stop means 1e in the blade chamber. The stopping means may be provided on the auxiliary base plate 2. The tip of the shutter blade 4 can come into contact with the stopping means 1e. On the other hand, a spring 13 is hooked on the shutter blade 5. This spring 13 is a coil spring as is apparent from FIG. 2, and is wound around the shaft portion 2b of the auxiliary base plate 2, one end of which is hooked on the pillar 2c and the other end of which is attached to the shutter blade 5. Three holes 5 arranged in an arc shape
It is hung on the hole 5b in the middle of b, 5b, 5b. The spring 13 biases the shutter blade 5 in the closing operation direction, and the biasing force is adjusted by selecting the position to which the other end is applied from the three holes 5b, 5b, 5b.

Next, the operation of this embodiment will be described. Before that, the closed state of the shutter shown in FIGS. 1, 3, and 4, in other words, the state where the shutter blades are at the operation start position will be described. Keep it. In this state, the coil 10 is not energized. Therefore, the rotor 8 is unstable in the rotation direction. Therefore, in order to stabilize the position of the rotor 8, a magnetic member is arranged on a part of the stator of the motor M, and the closed state is maintained by the magnetic force acting between the magnetic member and the rotor 8. There are known ways to do so. However, in this embodiment, such a magnetic body is not arranged.

In this embodiment, since the spring 13 biases the shutter blade 5 in the closing direction, the operating pin 12a is formed.
The rotation of the rotor 8 in the counterclockwise direction is suppressed via the. Further, at that time, the shutter blades 4 move the operation pin 12
It is indirectly urged in the closing direction via a, and its front end is brought into contact with the stopping means 1e to prevent the clockwise rotation. Further, in order to effectively obtain such a state, in the stationary state in which the openings 1a and 2a are closed, the operating pin 12a has the hole 1d.
It does not come into contact with the end face of the and is slightly spaced.

In this embodiment, as described above, the shutter blade 4
To the shutter blade 5 and the spring 13 to the shutter blade 5.
In the closed state, the action of FIG.
, The left side surface of the long hole 4a and the long hole 5 are always connected.
The side surface on the right side of "a" is in contact with the operating pin 12a. Therefore, no matter what the fitting tolerance between the actuating pin 12a and the long holes 4a, 5a is, the relative positional relationship among the three members is maintained constant, and vibration is applied or the camera is held differently. This relationship has not changed.

In this structure, even if the above-mentioned magnetic member is provided and the rotor 8 is biased in the clockwise direction, a spring is applied to the opening / closing member 12 to rotate it. Even if the child 8 is configured to be urged in the clockwise direction, it is possible to maintain the relative positional relationship among the three in a similar manner. Further, in this state, it is preferable that the actuating pin 12a is not in contact with the end surface of the hole 1d as in the present embodiment.
Even if the contact is made and the stop position of the operating pin 12a is restricted thereby, the shutter blade 5
It is possible to keep the relative positional relationship of the three members constant in the same manner by ensuring that the tips of the two contact the stop means 1e.

When the release button of the camera is pressed in such a closed state, that is, in the state of the exposure operation starting position, first, the distance measuring device and the photometric circuit are activated in the initial stage. Then, when a forward current is supplied to the coil 10, the rotor 8 is rotated counterclockwise, and the shutter blades 4 and 5 are opened by the operation pin 12a. At this time, as can be seen from FIG.
First, a presses the right side surface of the elongated hole 5a against the urging force of the spring 13 to operate the shutter blade 5, and then contacts the right side surface of the elongated hole 4a to operate the shutter blade 4 as well. It will be. In this embodiment, because of the configuration, the relative positional relationship between the operating pin 12a and the shutter blades 4 and 5 at the time of closing is always maintained in the same state. The operation timing is always constant, and does not change from one shooting to another due to posture differences or the like.

In this way, the shutter blades 4 and 5 are
The shafts 1b and 1c rotate relative to each other, and the openings 1a and 1c
Open 2a. Then, the opening operation is stopped by the operation pin 12a coming into contact with the end surface of the hole 1d formed in the shutter base plate 1, resulting in a fully opened state as shown in FIG. Immediately or after a predetermined time has passed from this state, this time, the coil 10 is energized in the opposite direction. As a result, the rotor 8 rotates in the clockwise direction, so that the shutter blades 4 and 5 perform an operation opposite to the above-described opening operation by the operation pin 12a, and the openings 1a and 2a.
Close up.

After closing the openings 1a and 2a, first, the tip of the shutter blade 4 comes into contact with the stopping means 1e, but after that, the operating pin 12a slightly bends the shutter blade 4 to form the hole 1d. Contact the end face. After that, the shutter blade 4 returns to its original shape by the elasticity due to the bending, and all the members come to the state of FIG. 1 and stop. This state is the closed state after the end of shooting and the initial state of the next shooting. As described above, this state does not change regardless of what kind of vibration is applied or how the camera is held in the next shooting.

In the above embodiment, the operation pin 1
Although the opening / closing member 12 having 2a is integrally formed with the rotor 8, the present invention separates the opening / closing member 12 from the rotor 8 and rotatably attaches it to the shutter base plate 1 so that the rotor 8 can be rotated. It may be configured to reciprocate by reciprocating rotation of. Alternatively, a spring may be applied to the opening / closing member 12, the driving force for the opening operation may be obtained from the motor, and the driving for the closing operation may be performed only by the spring. Further, the present invention can be applied to a shutter base plate 1 which is rotatably attached to the shutter base plate 1 so that both the opening operation and the closing operation are driven by springs.

Further, in the embodiment, the spring 13 biases the shutter blade 5 in the closing direction. However, when the spring force is used as a driving source for the closing operation as described above, or the magnetic member is used. When urging in the closing direction using
Even if the spring force applied to the shutter blades 5 is weak and the shutter blades 5 are biased in the opening direction, the same effect can be obtained. Furthermore, for the shutter that relatively opens and closes the two shutter blades, as in the present embodiment, in addition to the type in which one operating pin is fitted in the long holes of both blades, it operates on the opening and closing member. There is known a type in which two pins are provided and they are respectively fitted into the long holes of different blades. The present invention can also be applied to such a type of shutter.

[0023]

As described above, according to the present invention, in a camera shutter in which two shutter blades are relatively opened and closed, one of the blades is brought into contact with the stop means in the closed state and the other blade is contacted. By adopting an extremely simple structure, which applies a spring that biases in the rotation direction,
Even if there is any fitting tolerance between the operating pin of the opening / closing member and the long hole of the shutter blade, the relative positional relationship between the operating pin and the two shutter blades in the closed state can always be kept constant. Therefore, it is possible to eliminate the occurrence of so-called nonuniformity such as different exposures for each shooting in the shooting with the same field brightness.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment showing a closed state of shutter blades.

FIG. 2 is a central cross-sectional view of FIG.

FIG. 3 is a plan view of the inside of the blade chamber according to the embodiment,
The closed state of a shutter blade is shown.

FIG. 4 is an enlarged explanatory view of a main part of FIG.

FIG. 5 is a plan view of the inside of the blade chamber according to the embodiment,
The fully opened state of the shutter blades is shown.

[Explanation of reference numerals] 1 shutter base plates 1a, 2a openings 1b, 1c, 2b shaft parts 1d, 5b holes 1e locking means 2 auxiliary base plates 2c pillars 3, 9 screws 4, 5 shutter blades 4a, 5a long holes M moving magnets Mold motor 6 Upper frame 7 Lower frame 8 Rotor 8a Rotating shaft 10 Coil 11 Yoke 12 Opening / closing member 12a Operating pin 13 Spring

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-160491 (JP, A) JP-A-8-6107 (JP, A) JP-A-7-49514 (JP, A) JP-A-5- 313226 (JP, A) JP-A-5-127220 (JP, A) Actual flat 4-20025 (JP, U) Actual flat 5-84943 (JP, U) Actual flat 5-59435 (JP, U) 59-41337 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03B 9/00-9/70

Claims (4)

(57) [Claims] 1. Two base plates having an opening for exposure and forming a vane chamber between the two, and one of the two base plates pivotally mounted in the vane chamber when each is closed.
When two shutter blades having long holes that intersect with each other and one operation pin fitted in both of the long holes are reciprocated by a driving source during exposure. An opening / closing member that relatively reciprocates the two shutter blades to open and close the opening, and an opening / closing member that is provided on one of the base plates and prevents the operation of one shutter blade in the closing direction when the opening is closed. Stopping means and a spring which is hung on the other shutter blade to urge the shutter blade to rotate in the closing direction and which brings the one shutter blade into contact with the stopping means via the operation pin. A camera shutter characterized by being provided. 2. Opening operation of reciprocating operation of the opening / closing member
The drive source of the is a motor, the drive source of the closing operation is a spring
Camera shutter according to claim 1, characterized in that. 3. A drive source for reciprocating the opening / closing member is a motor.
The shutter for a camera according to claim 1, wherein the shutter is a camera. 4. The motor is a moving magnet type.
A motor, wherein the opening / closing member is the moving magnet.
That it is integrated with the rotor of the
The camera shutter according to claim 3 , wherein the shutter is for a camera.