JPH043532B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a focal plane shutter time adjustment mechanism, and more particularly, to a mechanism for directly restraining a drive lever member having a driving force source for driving a group of shutter blades to an electromagnetic device. This invention relates to a time adjustment mechanism for focal plane shutters.

For example, in a focal plane shutter of the type in which the opening/closing timing of the shutter blade is electromagnetically controlled by an electromagnetic device,
There is a slight delay (commonly referred to as a "mechanical delay") between when the open or close signal is input to the electromagnetic device and when the shutter blades actually start moving, so it is important to check the exact shutter speed. Various adjustments have been made to achieve this.

The main adjustment is to configure the circuit so that the signal input to the electromagnet device is earlier to account for the mechanical delay, but it is not possible to obtain accurate shutter time by adjusting the circuit configuration alone. That was difficult.

Therefore, when the engagement amount of the locking lever member that inhibits engagement of the drive lever member with the drive lever member is changed, and the locking lever member disengages the drive lever member under control of the electromagnetic device, the amount of engagement with the drive lever member is changed. The start timing of the shutter blade can be adjusted by changing the timing of disengaging, or by adjusting the force of the spring acting on the locking lever member. It is being done.

However, adjusting the start timing as described above does not work in a type where the drive lever member is indirectly inhibited, that is, in a type where the drive lever member is inhibited from being engaged by a locking lever member controlled by an electromagnetic device. Although this is possible, it has not been possible with a type in which the drive lever member is directly restrained by the electromagnetic device.

For this reason, in focal plane shutters in which the drive lever member is directly restrained by an electromagnetic device, the mechanical delay has traditionally been adjusted using a circuit configuration, but this has resulted in a complicated configuration. It had the disadvantage of being

In addition, although the method of adjusting by mechanical means is simple in principle, the actual adjustment work may be affected by mechanical shocks due to variations in the engagement accuracy of parts and mechanical errors due to the dimensional accuracy of individual parts. It also had the disadvantage of becoming more difficult.

The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and provides a focal plane shirt that can be easily and accurately adjusted and fixed in the adjusted state by a simple means that does not require a complicated circuit configuration. The purpose of this invention is to provide a mechanism for adjusting the time of the computer.

An object of the present invention is to provide a focal plane shutter in which a drive lever member having a driving force source for running a group of shutter blades is directly restrained to an electromagnet device, by rotating a coil bobbin of the electromagnet device by rotating an eccentric shaft. causing elastic displacement, transmitting this elastic displacement to the iron core, and changing the start position of the operation of the drive lever member by the follow-up displacement of the iron core,
This is achieved by using a configuration in which the starting position of the shutter blade relative to the aperture is changed through slight displacement of the drive lever member.

The present invention will be described below based on the embodiments shown in FIGS. 1 and 2.

In addition, Fig. 1 is a plan view showing the shutter in the set state (more precisely, the state immediately after the shutter button is pressed), and Fig. 2 is a cross section of the main part of Fig. 1 in the direction of arrow A-A. However, in order to simplify the drawing, some members (mounting plates 8, 1 of the electromagnet device 2) are shown in FIG.
0) is omitted.

In the figure, 1 is a substrate on which an aperture 1a is formed.

Reference numeral 2 denotes an opening electromagnetic device, which includes a coil bobbin 3 made of an elastic material such as plastic, an iron core 4 that can slide into the hollow part of the coil bobbin 3, a spring 5 that presses the iron core 4 against the coil bobbin 3, and a spring 5 that presses the iron core 4 against the coil bobbin 3. It consists of a coil 6 wound around 3. The spring 5 absorbs the overrun of the drive lever 13, which will be described later, during setting. The detailed structure of the coil bobbin 3 is as shown in FIG. 2, and includes foot portions 3a, 3b, 3c, and a collar portion 3d.
3f is fitted into the hole of the mounting plate 8 to be assembled to the mounting plate 8. Further, a slot 3g is formed in the foot portion 3c, and this slot 3g
A pin portion 9a of the eccentric shaft 9 is fitted into the pin portion 9a. The eccentric shaft 9 is rotatably supported by a mounting plate 10. Further, although the tip of the flange portion 3d is in contact with the mounting plate 10, it is processed so that the contact area is reduced. Further, one end of the spring 5 is connected to a pin 11.
It is supported by the leg portion 3c via.

Then, by fixing the mounting plate 8 to the substrate 1, the electromagnet device 2 is attached to the substrate 1.

13 is a driving lever for the leading blade, and a member 13a is connected to a lever (not shown) for the leading blade group 19, which will be described later, through a slot (not shown) formed in the base plate 1, roller 13b, member 1
3c, an iron piece 15 is pivotally attached to the member 13c via a dowel 14, is pivotally supported on the substrate 1 via a shaft 16, and is provided with a levorotatory driving force by a spring 17. However, the iron piece 15 is held by suction to the iron core 4, thereby being restrained.

19 is a group of leading blades, including slit forming blades 19a;
It is composed of cover blades 19b and 19c,
It covers the aperture 1a.

The state shown in FIG. 1 is the state immediately after the shutter button is pressed, and the set lever retracts at the same time as the mirror flips up, releasing the pressure on the set roller 13b.

The above is an explanation of the configuration for the leading blade, but the configuration for the trailing blade is also exactly the same, so the configuration for the trailing blade is the configuration code for the leading blade plus 20.
A description thereof will be omitted.

Next, the operation of the above configuration will be explained.

First, when the current to the coil 6 wound around the coil bobbin 3 is cut off, the magnetic force of the iron core 4 disappears, and the drive lever 13 rotates to the left along with the iron piece 15 due to the force of the spring 17. Then, by turning the drive lever 13 to the left, the leading blade group 19 travels from the deployed state covering the aperture 1a, and is folded to the position where the aperture 1a is opened.

Thereafter, when a predetermined exposure time has elapsed, the current to the coil 26 wound around the coil bobbin 23 is cut off, the magnetic force of the iron core 24 disappears, and the drive lever 33 is moved with the iron piece 35 by the force of the spring 37. Turn left. Then, by turning the drive lever 33 to the left, the rear blade group 39 travels from the folded state and unfolds to cover the aperture 1a.

Next, a case will be described in which the starting positions of the leading blade group 19 and the trailing blade group 39 are adjusted. Incidentally, such adjustment is mainly performed when assembling and adjusting the shutter.

When the eccentric shaft 9 is rotated in the state shown in FIG. 2 in order to adjust the starting position of the leading blade group 19, the coil bobbin 3 moves up and down (in FIG. 2) via the pin 9a. Note that this vertical movement is performed by elastically distorting the coil bobbin 3. Therefore, the iron core 4 follows due to the action of the spring 5, and the drive lever 13 is slightly rotated to the left or to the right via the iron piece 15. As a result, the leading blade group 19 also moves slightly via the member 13a, and the lower edge 19a' of the slit forming blade 19a and the aperture 1a
The distance l of the lower edge 1a' of changes. Therefore, the time from when the drive lever 13 starts turning to the left until the leading blade group 19 actually starts opening the aperture 1a changes.

The same applies to the rear blade group 39, and by rotating the eccentric shaft 29, the distance L between the upper edge 39a' of the slit-forming blade 39a and the lower edge 1a' of the aperture 1a changes.

FIG. 3 is a sectional view showing another embodiment of the iron core constituting the electromagnet device 2. FIG. In this embodiment, an arcuate protrusion 104a is formed on the iron core 104, and the coil bobbin 3 comes into contact with the protrusion 104a. Note that the protrusion 104a is formed so that an imaginary line passing through the apex of the protrusion 104a and the center point of the cross section of the spring 5 is parallel to the mounting plate 8.

Therefore, even if the coil bobbin 3 is displaced in the direction of the arrow B, the coil bobbin 3 always remains at the apex of the projection 104a.
Since the iron core 104 comes into contact with the iron core 104, the left and right balance of the iron core 104 can be maintained. This means that coil bobbin 3
The same effect can be obtained by forming a protrusion on the side.

On the other hand, in the structure shown in FIG. 2, when the coil bobbin 3 is displaced in the direction of the arrow B, the contact point a between the coil bobbin 3 and the iron core 4 moves, which is not very preferable. In other words, when the contact point is at position a, when the iron piece 15 moves in the direction of arrow C (when the magnetic force of the iron core 4 demagnetizes and separates), the iron core 4 slightly moves due to the influence of residual magnetism. It gets pulled and turns to the right. Therefore, the timing at which the iron piece 15 is completely separated from the iron core 4 varies slightly depending on the amount of displacement of the coil bobbin 3.

The above is a description of the embodiments of the present invention, but it goes without saying that the present invention is not limited to these embodiments.

For example, instead of the above-mentioned type, the electromagnetic device may be of a type in which the iron cores 4, 24 are made of permanent magnets, and the iron pieces 15, 35 are released from adsorption by energizing the coils and causing reverse excitation.

Further, the present invention can also be implemented in a device in which either the leading blade group or the trailing blade group is a mechanical release.

As mentioned above, in order to slightly move the iron core in the thrust direction, the rotational displacement of the eccentric shaft is converted into the elastic displacement of the coil bobbin, and this elastic displacement is applied to the contact between the iron core and the coil bobbin, which is made of an elastic body. is transmitted to the iron core to cause a slight displacement of the iron core in the thrust direction.

Therefore, the mechanical shock is absorbed by the effect of the elastic properties of the coil bobbin, so the displacement is transferred very smoothly and continuously without any mechanical shock. The core can be moved slightly.

Furthermore, the adjustment work can be done easily and reliably by only having to do the adjustment work once, in which the eccentric shaft is gradually rotated and the rotation work is stopped when the desired position is reached.

[Brief explanation of drawings]

FIG. 1 is a plan view of an embodiment according to the present invention, FIG. 2 is a sectional view taken along the line A--A in FIG. 1, and FIG. 3 is a plan view of another embodiment according to the present invention. 2... Electromagnetic device for the leading blade, 3... Coil bobbin, 4,104... Iron core, 5... Spring, 9...
Eccentric shaft, 13... Drive lever, 15... Iron piece, 1
9... Lead blade group, 19a... Slit forming blade,
22... Electromagnet device for rear blade, 23... Coil bobbin, 24... Iron core, 25... Spring, 33...
Drive lever, 35...iron piece, 39...rear blade group,
39a... Slit forming blades, l, L... Distance to the start position.

Claims (1)

[Scope of Claims] 1. A drive lever member having a driving force source for driving a shutter blade group and connected to the shutter blade group, and an iron piece member pivotally connected to the drive lever member being held by suction. an electromagnetic device for directly inhibiting the operation of the drive lever member, and releasing the inhibition of the drive lever member by eliminating the attractive force of the electromagnet device, In a focal plane shutter in which the shutter blade group moves to open or cover an aperture in conjunction with the movement of a member, the electromagnetic device is configured to move against a substrate supporting the drive lever member. a coil bobbin made of an elastic body and assembled so as to be displaceable; an iron core displaceable in the thrust direction with respect to the coil bobbin; an elastic member that presses the iron core in the thrust direction with respect to the coil bobbin; and an eccentric shaft that elastically displaces the coil bobbin, and by rotating the eccentric shaft, the coil bobbin is elastically displaced, and the coil bobbin is attracted to the iron core and the iron core by the elastic displacement. A focal plane characterized in that the starting position of the shutter blade group with respect to the aperture is changed by causing the iron piece member to follow the displacement and slightly moving the drive lever member through the follow-up displacement. Shutter time adjustment mechanism. 2. A drive lever member having a driving force source for driving the shutter blade group and connected to the shutter blade group, and an iron piece member pivotally attached to the drive lever member are held by suction to thereby drive the shutter blade group. an electromagnetic device that suppresses the movement of the lever member, and releases the suppression of the drive lever member by eliminating the attractive force of the electromagnetic device, and is linked to the movement of the drive lever member. In a focal plane shutter in which the shutter blade group moves so as to open or cover an aperture, the electromagnet device is displaceably assembled with respect to a substrate supporting the drive lever member. a coil bobbin made of an elastic body and made of an elastic body, and an iron core that is displaceable in a thrust direction with respect to the coil bobbin and has an arc-shaped protrusion that contacts the coil bobbin on a surface perpendicular to the thrust direction of the coil bobbin. , an elastic member that presses the iron core in the thrust direction against the coil bobbin, and an eccentric shaft that elastically displaces the coil bobbin, and by rotating the eccentric shaft, the coil bobbin is elastically displaced. and transmitting the elastic displacement through contact with the arcuate protrusion to cause the iron core and the iron piece member adsorbed to the iron core to follow the displacement;
A second time adjustment mechanism for a focal plane shutter, characterized in that the starting position of the shutter blade group relative to the aperture is changed by slightly moving the drive lever member through the follow-up displacement. 3. By integrally forming an arc-shaped protrusion on a surface perpendicular to the thrust direction of the coil bobbin and bringing the arc-shaped protrusion into contact with the iron core, elastic displacement of the coil bobbin due to rotation of the eccentric shaft can be suppressed. 3. A focal plane shutter time adjustment mechanism according to claim 2, wherein the time is converted and transmitted to the iron core.