JPH0579969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electromagnetic drive shutter that uses an electromagnetic drive device to drive an open blade group and a closed blade group.

[Conventional technology]

In recent years, cameras have become increasingly electronic, and functions such as exposure control, charging of the film winding mechanism, and operation of the mirror mechanism have come to be handled electrically. However, since conventional shutters use springs as the drive source for the shutter blades, shutter charging requires a mechanical linkage mechanism and a large amount of electrical energy, which is difficult for electrically controlled cameras. It was a big disadvantage. Therefore, an electromagnetic drive shutter which eliminates the mechanical connection mechanism with the camera body and is controlled only by electrical signals and saves power has been proposed and is now well known.

[Problem that the invention seeks to solve]

However, the conventional electromagnetic drive shutter mentioned above,
Since the shutter blade is not temporarily held on the start side, the start position of the shutter blade during exposure operation, which is an important element in controlling the exposure time, is not stable, which can cause irregular adjustment of the exposure time. There was a problem with getting older.

Therefore, a configuration in which the shutter blades are temporarily held at the starting position using an electromagnet or a combination type magnet has been considered, but in this case, the structure is complicated and expensive considering the number and type of components, and it is difficult to save energy. This is not necessarily a preferable configuration from this point of view.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an electromagnetic drive shutter with a simple and power-saving structure and stable exposure time.

[Means and actions for solving problems]

The electromagnetic drive focal plane shutter according to the present invention has a pair of electromagnetic drive devices that respectively drive an open blade group and a closed blade group. A driving force is applied to bring the blade drive members of the open blade group and the closed blade group into contact with the position regulating member, and a driving force in the exposure operation direction is applied to the electromagnetic drive device in the second stage of release. At the same time, the contact position of the position regulating member with respect to the blade driving member of each of the open blade group and the closed blade group is adjustable in at least one of the open blade group and the closed blade group, and an electromagnet or the like is provided. The starting position of the shutter blade during exposure operation can be stabilized without using the shutter blade.

〔Example〕

Hereinafter, the present invention will be explained in detail based on an illustrated embodiment.

FIG. 1 shows the configuration of the main parts of the shutter of the present invention, in which 1 is a shutter plate having an aperture 1a, 2 is an open blade drive source such as a motor fixed to the shutter plate 1, and 3 is an open base. An open pin 3a fixed to the drive shaft of the blade drive source 2 and connected to one of the support arms 5, 5 of the open blade group 4 at its tip end, and an engagement pin 3b capable of engaging with a position regulating member to be described later. Fixed open vane drive member. Reference numeral 6 designates an open blade position regulating member mounted on the shutter plate 1 so that its position can be adjusted by a shaft 7 and a first adjustment eccentric shaft 8.

Reference numeral 9 denotes a closing blade drive source such as a motor fixed to the shutter plate 1, and 10 has a base fixed to the drive shaft of the closing blade drive source 9, and a distal end attached to one of the support arms of the closing blade group (not shown). This is a closing blade drive member to which a connected closing pin 10a and an engaging pin 10b that can engage with a position regulating member described later are fixed. A closing blade position regulating member 11 is mounted on the shutter plate 1 so that its position can be adjusted by a shaft 12 and a post-adjustment eccentric shaft 13.

In addition, both of the above-mentioned position regulating members may be of a fixed type, or only one of them may be of an adjustable type. Further, the blade driving source may be a direct type or a linear motor type that does not require a driving member.

FIG. 2 shows the control circuit of the above embodiment,
SW is a release switch, FF is a flip-flop, OSM ₁ , OSM ₂ , OSM ₃ are one shot multi, ORG ₁ , ORG ₂ are OR gates, NORG is a NOR gate, 14 is an exposure time control circuit, 15 is a shutter set circuit, T ₁ to T ₁₁ is a transistor, and E is a power supply.

Since the electromagnetic drive shutter according to the present invention is constructed as described above, the operating principle will be explained with reference to FIG. 3 showing changes in the operating state of each member and FIG. 4 showing the operating sequence. When the contact of the release switch SW is switched from the reset terminal R of the flip-flop FF to the set terminal S, the output Q of the flip-flop FF becomes "H" and the transistor _T1 becomes conductive. At the same time, one-shot multi OSM ₁ outputs an output, and the rise of the output signal triggers an OR gate.
The output of ORG ₁ becomes "H", transistors T ₂ and T ₃ become conductive via the inverter, and a driving force in the setting direction is applied to the open blade drive source 2, and the open blade drive member is activated as shown in FIG. 3 is the engaging pin 3
b is rotated to the right until it comes into contact with the opening blade position regulating member 6 and reaches the regulated position, that is, the start position.
On the other hand, at the same time as above, the output Q of the flip-flop FF becomes "L", and since the output of the exposure time control circuit 14 is "L" in the initial state, the NOR gate
The output of NORG becomes “H” and the OR gate ORG ₂
The output becomes "H", transistors T ₈ and T ₉ become conductive via the inverter, a driving force in the setting direction is applied to the closing blade drive source 9, and the closing blade driving member 10 closes its engagement pin 10b. It is rotated to the right until it comes into contact with the blade position regulating member 11 and reaches the regulated position, that is, the start position.

Next, due to the fall of the output signal of the one-shot multi OSM ₁ , the output of the OR gate ORG ₁ becomes "L", and this time it is passed through the inverter to the transistor.
T ₄ and T ₅ are electrically connected, a driving force in the exposure operation direction is applied to the closing blade drive source 2, the opening blade driving member 3 is rotated to the left, the opening blade group 4 is retracted from the photographing optical path, and exposure is started. . At the same time, the exposure time control circuit 14 starts measuring time, and after a predetermined time has elapsed, its output becomes "H". Then, the transistors T ₁₀ and T ₁₁ become conductive via the inverter, and a driving force in the exposure operation direction is applied to the closing blade drive source 9, and the closing blade driving member 10 rotates to the left to move the closing blade group onto the photographing optical path. is covered and the exposure is completed.

Further, when the output of the exposure time control circuit 14 becomes "H" and becomes "L" via the inverter, the output of the one shot multi OSM ₂ becomes "H" after a predetermined delay time in the shutter set circuit 15, One shot multi with a certain time difference
The output of OSM ₃ becomes "H". When the output of one-shot multi OSM ₂ becomes “H”, it is an OR gate.
Since the output of ORG ₁ becomes "H", transistors T ₂ and T ₃ become conductive via the inverter, and the opening blade drive source 2 operates in the setting direction, so that the opening blade group 4 covers the photographing optical path. return. After that, when the output of one-shot multi OSM ₃ becomes "H", the output of OR gate ORG ₂ becomes "H", so transistors T ₈ and T ₉ become conductive via the inverter, and the closed blade group is retracted from the photographing optical path. do. The setting is thus completed.

The operating principle of the electromagnetic drive shutter of the present invention has been explained above.The electromagnetic drive shutter of the present invention applies a driving force in the setting direction to the electromagnetic drive device in the first stage of release, so that the blade drive member hits the position regulating member. Since they are in contact with each other, the starting position of the shutter blade during exposure operation is stabilized, and as a result, the exposure time is stabilized. Moreover, since there is no need to use an electromagnet or the like, the structure is simple and power-saving. Further, since the start position can be adjusted by adjusting the position of the position regulating member, a more accurate exposure time can be obtained.

〔Effect of the invention〕

As described above, the electromagnetically driven shutter according to the present invention has the important practical advantages of a simple and power-saving structure and stable exposure time.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of essential parts of an embodiment of an electromagnetic drive shutter according to the present invention, Fig. 2 is a diagram showing a control circuit of the above embodiment, and Fig. 3 is a diagram showing the operating state of each member of the above embodiment. FIG. 4 is a diagram showing the operation sequence of the above embodiment. DESCRIPTION OF SYMBOLS 1... Shutter plate, 2... Open blade drive source, 3... Open blade drive member, 4... Open blade group, 5... Support arm, 6... Open blade position regulating member, 7... Shaft, 8... Pre-adjustment eccentric shaft, 9... Closing blade drive source, 10... Closing blade driving member, 11
...Closing blade position regulating member, 12...Shaft, 13...
...Post-adjustment eccentric axis, 14...Exposure time control circuit, 1
5...Shutter set circuit, SW...Release switch, FF...Flip-flop, OSM ₁ ,
OSM ₂ , OSM ₃ ……One shot multi, ORG ₁ ,
ORG ₂ ...Or Gate, NORG...Noah Gate,
_T1 to _T11 ...transistor, E...power supply.

Claims (1)

[Claims] 1. In an electromagnetically driven focal plane shutter having a pair of electromagnetic drive devices that respectively drive an open blade group and a closed blade group, a driving force in the set direction is applied to the electromagnetic drive device in the first stage of release, and the drive force is applied in the set direction to the release blade group. bringing the blade driving members of each of the blade group and the closing blade group into contact with a position regulating member;
Applying a driving force in the exposure operation direction to the electromagnetic drive device at the second stage of release, and
The electromagnetic device is characterized in that the contact position of the position regulating member with respect to the blade driving member of each of the open blade group and the closed blade group is configured to be adjustable in at least one of the open blade group and the closed blade group. Drive focal plane shutter.