JPH058590Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a control system that stabilizes the operation of a focal plane shutter for a camera over a wide range and simplifies the setting mechanism. Regarding equipment.

[Prior art and its problems]

In a focal plane shutter, when the blade driving member is driven by an applied driving force, the initial speed is slow and the final speed is fast due to the action of inertia. Therefore, in the exposure time where the exposure time is controlled by slits between the leading blade and the trailing blade, the slit width is narrow in the exposure region where the aperture begins to open, and this has the drawback that exposure unevenness is likely to occur, especially when controlling the time at high speed. be. Furthermore, since the final speed is fast, it is necessary to apply braking in the final region of operation, making the structure complicated.

On the other hand, in the case of an electric shutter, the member that releases the locking member that locks the blade drive member in the tensioned position is provided opposite to the electromagnet, and is given a tendency to separate from the electromagnet. It is an iron piece member.
When setting the shutter, the iron piece member is subjected to a set operation in which it is brought from a position away from the electromagnet to a position to be attracted, at the same time as the blade driving member is brought to the tension position. It's getting old. Therefore, needless to say, the shutter setting mechanism requires a portion that acts on the iron piece member, making the structure complicated.

[Purpose of invention]

The purpose of this invention is to skillfully latch (engage) the other end of a spring whose one end is latched (engaged) to the iron piece member and which originally gives the iron piece member a tendency to separate from the electromagnet to the vane drive member. This helps the initial speed of the blade drive member's operation, reduces the final speed, eliminates the need to set the iron piece member, stabilizes the shutter operation over a wide range, and improves exposure accuracy. At the same time, the braking action can be reduced.
Another object of the present invention is to provide a focal plane shutter control device that can simplify the shutter setting mechanism.

[Summary of the idea]

The object of the present invention is to provide a blade driving member that is arranged to be movable between a first position and a second position, and is provided with a driving force from the first position to the second position;
a locking member that is given an operating habit so as to lock the blade drive member at the first position; an electromagnet for shutter release control; and a position between an attracted position and a separated position with respect to the electromagnet. an iron piece member that is movably disposed and is pushed by operation from the attracted position to the separated position to displace the locking member in a direction to release the lock from the blade driving member against its operating habit; and a spring whose one end is latched (engaged) to the iron piece member to give the iron piece member an operating habit from the adsorbed position to the separated position. The blade driving member is driven when the other end is latched (engaged) to the blade driving member and the blade driving member is moving from the first position to the second position by releasing the locking. a first time period acting as an assisting force against the force, and pulling the iron piece member from the separated position to the attracted position while releasing the pushing force against the locking member by the driving force of the blade driving member. It has a second time period in which it acts as an intermediary member, and a third time period in which it acts as a reducing force with respect to the driving force of the blade driving member after the iron piece member reaches the adsorbed position. This is roughly achieved by certain things.

[Example of idea]

Hereinafter, embodiments of the present invention will be described based on the drawings.

Figures 1 to 4 show operating changes of the control system on the leading blade side of a focal plane shutter, for example, with Figure 1 in the set state and Figures 2 and 3 in the middle of operation. FIG. 4 is an explanatory diagram showing the stationary state.

In the drawings, reference numeral 1 designates a leading blade drive lever which is pivotally mounted on a shaft 2 and given left-handed rotation by a spring 3, and forms a locked arm portion 1a.
Pins 1b and 1c are implanted therein, and they are arranged so as to be movable between the first position shown in FIG. 1 and the second position shown in FIG. 4. The pin 1b passes through the shutter base plate (not shown) (the drive lever 1
The operating range of the shutter is limited, for example, by both end faces of a long groove formed in the shutter base plate for this penetration. ) and protrudes to the back side of the page, and is connected to the operating arm of the leading blade (not shown).

Reference numeral 4 denotes a locking lever which is pivotally connected to a shaft 5 and is given a right-handed rotation by a spring 6 until it is restricted to a stopper 7. It forms a stop arm part 4a and a pushed arm part 4b which is pushed by an iron piece lever which will be described later.

Reference numeral 8 denotes a fixed electromagnet, which is composed of a magnetic pole 8a, a permanent magnet 8b, and a coil 8c.

Reference numeral 9 denotes an iron piece lever pivotally attached to the shaft 2, which includes an iron piece 9a facing the magnetic pole 8a of the electromagnet 8, and a pin 9b for pushing the pushed arm portion 4b of the locking lever 4. and another pin 9c are implanted, and are arranged so as to be movable between the attracted position shown in FIG. 1 and the separated position shown in FIG. 2 with respect to the electromagnet 8.

Reference numeral 10 denotes a spring, the middle part of which is wound around the large diameter part 2a of the shaft 2, and the one end 10a of which is wound around the iron piece lever 9.
The other end 10b is latched (engaged) to the pin 1c of the leading blade drive lever 1. The spring 10, in the state shown in FIG. It gives left rotation habit in the same direction.

In the set state shown in FIG. 1, the iron piece lever 9 is attracted and held by the magnetic pole 8a through the iron piece 9a by the attractive force of the permanent magnet 8b of the electromagnet 8.

From the set state shown in FIG. 1, when the coil 8c is energized to release the leading blade and a magnetic force is generated in a direction that cancels the magnetic force of the permanent magnet 8a, the iron piece lever 9 releases its adsorption/holding. He was
It rotates to the right due to the tension of the spring 10. During this clockwise rotation process, the pin 9b pushes the pushed arm portion 4b and rotates the locking lever 4 to the left against the tension of the spring 6, thereby moving the locking arm portion 4a away from the locked arm portion 1a. Let it come off.

As a result, the leading blade drive arm 1 rotates to the left with the original driving force of the spring 3 assisted by the tension of the spring 10 and increases its initial speed, opening the leading blade (not shown) to the aperture. go.

In the process of left rotation of the leading blade drive arm 1, the pin 1c of the arm 1 also comes into contact with the one end 10a of the spring 10, and the spring 10 goes through a dead state (Fig. 2), and immediately after that, , iron piece lever 9
is pulled to the left by the left-turning action of the leading blade drive lever 1 using the spring 10 (the other end 10b pushes the pin 9c) as an intermediary member, and turns to the left, as shown in FIG.
The iron piece 9a is brought to a position where it is attracted by the magnetic pole 8a of the electromagnet 8.

Further, since the locking lever 4 is released from being pushed by turning the iron piece lever 9 to the left, the leading blade drive lever 4
It returns to the same state as in Fig. 1, where it can be locked.

Furthermore, the subsequent left rotation of the leading blade drive arm 1 is as follows:
In the process of reaching the final operating (resting state) position shown in FIG.
As a result, the driving force of the drive arm 1 is reduced, the final speed of the arm 1 is slowed, and the bouncing phenomenon at the final operating position is also reduced. , the braking mechanism at that location is unnecessary or can be achieved with a minor one.

In addition, in the above-mentioned setting of the shutter mechanism, in the stationary state shown in FIG. 4, the iron piece lever 9 is attracted and held by the electromagnet 8 through the iron piece 9a by the magnetic force of the permanent magnet 8a, so that only the leading blade drive lever 1 is turned on. Any mechanism that brings the state to the state shown in Figure 1 may be used.

In the drawings, only the leading blade drive system of the focal plane shutter is shown, but the trailing blade drive system is also constituted by a similar mechanism, and the trailing blades also have similar running characteristics.

Further, the spring 10 may be a toggle type spring whose both ends are supported at the positions of the pin 1c and the pin 9c, in addition to the spring 10 of the embodiment.

Furthermore, the electromagnet may be of a type that does not include a permanent magnet. In that case, in the set state, a holding member for the iron lever (a member that keeps the iron lever in pressure contact with the electromagnet; for example, in the case of a single-lens reflex camera, the mirror is held in the down state Upon release operation, the electromagnet is first energized to attract and hold the iron lever, then the holding member is retracted from the iron lever, and after a predetermined period of time, the electromagnet is turned on. The timing at which power is cut off is the original shutter release timing.

[Effect of idea]

This invention makes the running characteristics of the focal plane shutter uniform over a wide range, making the initial speed faster and the final speed slower, which stabilizes exposure accuracy and reduces braking action. Furthermore, since the shutter setting mechanism can be simplified, this is extremely effective in practice.

[Brief explanation of drawings]

Figures 1 to 4 show operating changes of the control system on the leading blade side of a focal plane shutter, for example, with Figure 1 in the set state and Figures 2 and 3 in the middle of operation. FIG. 4 is an explanatory diagram showing the stationary state. 1... Lead blade drive lever, 3... Spring, 4...
Locking lever, 8...electromagnet, 9...iron lever,
10...Spring.

Claims (1)

[Claims for Utility Model Registration] A vane driving member disposed so as to be movable between a first position and a second position, and to which a driving force is applied from the first position to the second position; and the vane. a locking member that is given an operating habit so as to lock the drive member in the first position; an electromagnet for shutter release control; and a locking member that is movable between an attracted position and a separation position with respect to the electromagnet. an iron piece member that is disposed in the adsorbed position and is pushed by operation from the adsorbed position to the detached position to displace the locking member in a direction to release the lock from the blade driving member against its operating habit; A focal plane shutter comprising: a spring that is latched (engaged) at one end to the iron piece member and gives the iron piece member an operating habit from the adsorbed position to the detached position, the spring having the other end; is latched (engaged) to the blade driving member, and during operation of the blade driving member moving from the first position to the second position by releasing the locking, with respect to the driving force of the blade driving member. a first time period acting as an assisting force; and acting as an intermediary member that pulls the iron piece member from the separation position to the adsorbed position while releasing the pushing force against the locking member by the driving force of the blade drive member. and a third time period in which, after the iron piece member reaches the adsorbed position, the iron piece member acts as a reducing force with respect to the driving force of the blade driving member. Calplane shutter control device.