JPH09258296A - Focal plane shutter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a focal plane shutter capable of detecting the abnormal operation of a front sector group and a rear sector group by one photoelectric detecting means. SOLUTION: When the attracting force of an electromagnet for the front sector is not adequate, the front sector follows up the return operation to the initial position of a set member, the front sector group immediately operates, and an arm 6 or the front sector 10 makes a photoreflector 4 output an L signal, and when the attracting force of the electromagnet for the second blade is not adequate, a rear sector driving member immediately operates, and the rear sector 11 makes the photoreflector 4 output the L signal. When a time for outputting the L signal is earlier than a reference elapsed time after releasing, a control circuit generates an abnormal signal.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a front blade group and a rear blade group, which are formed by supporting a plurality of blades by a plurality of arms, sequentially running in the same direction, and a film is formed by a slit formed by both blade groups. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focal-plane shutter for a camera that is exposed to light, and more particularly to a focal-plane shutter that can detect abnormal operation of each blade group.

[0002]

2. Description of the Related Art This type of focal plane shutter is
Each blade group is actuated by each driving member, and the control of the actuation start timing of each driving member is performed via the electromagnet prepared for each. There are roughly two methods of using this electromagnet, and generally one is called a locking type and the other is called a direct type.

Of these, the locking type is one in which the driving member is locked by a locking lever at the set position. Therefore, the set member can reliably hold the drive member in the set position until the exposure operation even if the drive member is returned to the initial position immediately after the drive member is set in the set position. , A so-called iron piece lever that is released from the electromagnet during exposure and releases the lock of the locking lever, or the iron piece lever is returned to the attractable position by the electromagnet in conjunction with the setting operation of the setting member, and the iron piece lever is moved before the exposure operation. A so-called hold lever or the like is required to retreat from the operating range of the iron piece lever after being attracted by the electromagnet, which has a complicated structure and is extremely disadvantageous in terms of cost.

On the other hand, in the direct type, an iron piece member provided on the driving member is attracted by an electromagnet. Therefore, the setting member cannot return to the initial position immediately after the driving member is set to the setting position, but returns to the initial position after the driving member is attracted to the electromagnet prior to the exposure operation. . Therefore, the above-mentioned various levers are unnecessary, which is extremely advantageous in terms of space and cost, and recent focal plane shutters of this type are increasing.

By the way, in these focal plane shutters, foreign matter adheres to the attracting surface of the electromagnet,
If the electromagnet circuit is broken or the power supply voltage drops,
The attraction of the electromagnet may not work properly.
The same thing occurs when the set stroke of each drive member by the set member is insufficient. In such a case, in the locking type, when the hold lever retracts from the operating range of the iron piece lever, the iron piece lever operates together, the locking lever is released and the drive member is controlled. It will operate immediately and cause the blade group to travel faster than the operating time controlled by the circuit. Further, in the direct type, the drive member having the iron piece member operates following the return operation of the set member, and the blade group is caused to travel immediately.

Therefore, it is necessary not only in the manufacturing process but also to detect such an abnormal operation even after the completion of the camera. Conventionally, the blade group traveling start time is In order to detect whether it is proper or not, separate detection means are provided on the leading blade side and the trailing blade side.

[0007]

However, disposing such detecting means separately in a narrow space in the shutter is a great limitation for disposing and assembling other components, which is extremely disadvantageous. is there. for that reason,
It is known that the detecting means on the leading blade side is also used as the switch for the X-contact of the flash, but in that case, there is still the problem of what to do with the detecting means on the trailing blade side. Depending on the shutter, there may be a shutter in which the detecting means on the rear blade side can be shared by another member, but there is a shutter which cannot be used. Further, as the conventional detection means, since the metal contact piece members are used, there is a problem that adjustment is necessary due to individual difference in shape of the contact piece or chattering cannot be eliminated.

The present invention has been made in order to solve such a problem, and an object thereof is to provide an abnormal operation of a leading blade group and a trailing blade group by providing only one photoelectric detecting means. SUMMARY OF THE INVENTION It is an object of the present invention to provide a focal plane shutter capable of detecting both abnormal operation of the.

[0009]

To achieve the above object, a focal plane shutter according to the present invention comprises a front blade group in which a plurality of blades are supported by a plurality of arms, and a front blade using a front blade electromagnet. For the trailing blade by means of the electromagnet for the trailing blade; The trailing blade drive member that is actuable by releasing the iron piece member and causes the trailing blade group to travel for exposure by the operation, and the optical path is not blocked by the leading blade group and the trailing blade group in the shutter set state, and the leading blade group and the trailing blade group during exposure traveling. And a photoelectric detection means arranged at a position where the optical path is blocked by any of the blade groups, and at the time of shutter release, the electromagnet for the leading blade and / or Optical path of the photoelectric detection means before transmitting the exposure running start signal to the second blade electromagnet is to detect the abnormal operation of the first blade groups and / or the rear blade group by being cut off. A focal-plane shutter featuring.

Further, in the focal plane shutter according to the present invention, preferably, the detecting means is arranged at a position near one side of the exposure opening to which each of the arms is attached, and the front blade group and the rear blade are arranged. The optical path is blocked by the arm or vane of the group. Further, in the focal plane shutter according to the present invention, preferably, the detecting means is arranged at a lateral vicinity position on a side opposite to one lateral position of the exposure opening to which each arm is attached, The optical path is blocked by the blades of the blade group and the rear blade group. Further, in the focal plane shutter according to the present invention, preferably, the detecting means is
It should also be used as a means for outputting the flash tuning signal.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to a first embodiment shown in FIGS. 1 to 5 and a second embodiment shown in FIGS. FIG. 1 is a plan view of the first embodiment showing a set state of the shutter, and FIG. 2 is a sectional view of the main part thereof. 3 and 4 are plan views of the first embodiment,
FIG. 3 shows the leading blade group in the middle of traveling, and FIG. 4 shows a state where the trailing blade group has malfunctioned. FIG. 5 is a time chart showing the operation of the first embodiment. 6 to 8 are plan views of the second embodiment. FIG. 6 shows the shutter set state, FIG. 7 shows the leading blade group in the middle of traveling, and FIG. 8 shows the trailing blade group in an abnormal operation state. Shows. Since the configurations of the first and second embodiments are almost the same, the same parts and the same parts are designated by the same reference numerals.

First, the configuration of the first embodiment is shown in FIGS.
This will be described with reference to FIG. Although this embodiment is a direct type focal plane shutter, it is well known that the drawing is complicated and that it is well known. Therefore, each driving member for the leading blade and the trailing blade, and each iron piece member provided in each driving member are provided. The electromagnets for adsorbing the front blade and the rear blade, and the set members for setting the front blade drive member and the rear blade drive member to the set position are not shown. In FIG. 1, the shutter base plate 1 has an exposure opening 1a and two arc-shaped holes 1a.
b and 1c are formed. Shafts 1d and 1e are provided upright on the front surface side of the shutter base plate 1. The shaft 1d is provided with a leading blade driving member, the shaft 1e is provided with a trailing blade driving member, and a rightward turning property is given by a driving spring. The shutter base plate 1 by inserting the respective drive pins through the holes 1b and 1c.
On the back surface of the blade is fitted into a hole formed in the arm of each blade group described later.

Each of the driving members is also provided with an iron piece member (not shown). In the set state of FIG. 1, each iron piece member is an iron core member and a trailing blade of the electromagnet for the leading blade. It is in contact with the iron core member of the electromagnet, and is in a state capable of attracting. Further, as shown in FIG. 2, an intermediate plate 2 and a cover plate 3 are sequentially attached to the back surface of the shutter base plate 1 with a predetermined gap therebetween, and the shutter base plate 1 and the intermediate plate 2 have a front end. A blade group and a rear blade group are arranged between the intermediate plate 2 and the cover plate 3. Since the overall shapes of the intermediate plate 2 and the cover plate 3 are well known, description thereof will be omitted.

As can be seen from FIG. 2, a photo-reflector 4 as a photoelectric detecting means is attached to the shutter base plate 1 by press fitting. As well known, the photo reflector 4 has a light emitting portion 4a and a light receiving portion 4b. Light emitted from the light emitting portion 4a passes through a hole 2a formed in the intermediate plate 2 and is attached to the cover plate 3. The light is reflected by the reflection sheet 5 and is incident on the light receiving portion 4b. In the case of the present embodiment, the photo reflector 4 is
As will be understood from the following description, in addition to being used as the above-mentioned abnormal operation detecting means, it also serves as a flash tuning signal output means.

On the back side of the shutter base plate 1, the shaft 1 is provided.
f, 1g, 1h, 1i are erected, and shafts 1f, 1g
Arms 6 and 7 for the front blade group are rotatably attached to the shafts, and arms 8 and 9 for the rear blade are rotatably attached to the shafts 1h and 1i. As is well known, four leading blades 10 are attached to the arms 6 and 7 to form a leading blade group. The leading blade driving member (not shown) is provided in the hole 6a formed in the arm 6. The drive pin of is engaged. Further, four trailing blades 11 are attached to the arms 8 and 9 to form a trailing blade group. However, since the mounting method is opposite to that of the leading blade group, the arms 8 and 9 are attached to the trailing blades. 11 on the back side, and only a part of the root is shown in the drawing. The drive pin of the rear blade drive member (not shown) is fitted in the hole 8a formed in the arm 8.

Next, the operation of this embodiment having such a configuration will be described with reference to the time chart of FIG. FIG.
Shows the set state of this embodiment, but when the exposure traveling is completed, the arms 6 and 6 are driven by the respective driving members.
7, 8 and 9 are in a state of being rotated clockwise by a predetermined angle from the state shown in FIG. 1, the leading blade 10 is folded and stored under the exposure opening 1a, while the trailing blade 11 is unfolded. The exposure opening 1a is covered. In this state, the photo reflector 4 is not energized. So, first,
The setting operation from such an exposure completed state will be described, but the setting operation is performed in conjunction with the film winding by a setting member (not shown). The setting member is not shown because it is well known, but the exposure opening 1a
It is rotatably attached to the shutter base plate 1 at a lateral position on the left side of.

Therefore, when the set member is rotated clockwise from the initial position, the set member rotates each of the above-mentioned drive members counterclockwise against their drive springs. When the slit forming blade 10a of the leading blade 10 overlaps with the slit forming blade 11a of the trailing blade 11 by a predetermined amount, the trailing blade driving member is also rotated counterclockwise. Therefore, the leading blade 10 and the trailing blade 11
When the film moves upward, there is no possibility that light is leaked from between the front blade 10 and the rear blade 11 to expose the film. In FIG. 5, the operation of the leading blade 10 is shown by a solid line, and the operation of the trailing blade 11 is shown by a broken line. After that, the set member stops each drive member in the overset state and then stops in a slightly left-handed state to complete the set operation. The state of the front blade group and the rear blade group at that time is shown in FIG. 1. In this state, the front blade 10 is expanded and the exposure opening 1a is opened.
The rear blade 11 is folded and stored above the exposure opening 1a. The iron piece member provided on each drive member is in contact with each electromagnet.

When the release button of the camera is pressed in the set state of FIG. 1, the leading blade electromagnet and the trailing blade electromagnet are energized as shown by the solid line in FIG. The members are attracted and each driving member is magnetically held. On the other hand, the photo reflector 4 is also energized,
At this time, the light emitted from the light emitting unit 4a is not blocked by the front blade 10, and thus enters the light receiving unit 14b and outputs the H signal. After such a state is obtained, the aforementioned set member is turned counterclockwise to return to the initial position. However, since each driving member is magnetically held by each electromagnet, the leading blade 10 and the trailing blade 11 do not immediately start exposure travel.

When a predetermined time has elapsed from the release and the reference time has been reached, the power supply to the leading blade electromagnet is cut off. Therefore, the leading blade driving member is rotated clockwise by the driving spring, and the arm 6 is rotated clockwise by the driving pin, so that the leading blade 10 is folded under the exposure opening 1a. Then, when the position of FIG. 3 is reached, the arm 6 and the blade 10 (either one of them may be blocked) cut off the optical path of the photoreflector 4 and output the L signal. Therefore, in the flash mode, a predetermined delay time elapses after the L signal is output, that is, the front blade 10 is completely exposed to the exposure opening 1a.
After it is folded down from, the flash is fired.
On the other hand, when the power supply to the electromagnet for the trailing blade is cut off in response to the signal from the photometric circuit, the trailing blade driving member is rotated right by the drive spring, and the trailing blade 11 is unfolded to cover the exposure opening 1a and travel for exposure. To finish.

In the above-described operation process after lasing, if an accident such as disconnection occurs in the control circuit of each electromagnet or foreign matter adheres to the attraction surface of the iron piece member, the attraction force of each electromagnet is increased. Is not obtained properly, it is indicated by a dashed line in FIG. First, when only the attraction force by the electromagnet for the leading blade is not properly obtained, the leading blade driving member immediately turns right following the return operation of the setting member to the initial position. The leading blade driving member causes the leading blade 10 to travel due to this right-handed rotation. Therefore, when the state shown in FIG. 3 is reached, the photoreflector 4 is moved.
The optical path of is blocked and the L signal is output. However, since this L signal is output much earlier than the reference time, the comparison circuit recognizes that the leading blade group has abnormally operated, and causes the control circuit to generate an abnormal signal. Even in the flash mode, the flash is not emitted by the output of the L signal.

If the attraction force of the leading blade electromagnet is properly obtained, but the attraction force of the trailing blade electromagnet is incorrect, following the return operation of the setting member to the initial position, Only the trailing blade drive member will immediately turn right. Then, as shown in FIG. 4, when the slit forming blade 11a of the rear blade 11 (three blades other than the slit forming blade 11a are omitted in FIG. 4) interrupts the optical path of the photo reflector 4, The L signal is output. Since this output timing is much earlier than the reference time, the comparison circuit recognizes that the leading blade group has abnormally operated and causes the control circuit to generate an abnormal signal. If the attraction force of both the electromagnet for the leading blade and the electromagnet for the trailing blade is improper, the leading blade group is detected first and an abnormal signal is generated.

Next, the second embodiment of the present invention shown in FIGS.
An embodiment will be described. In the configuration of the second embodiment, the photoelectric detecting means is the photo interrupter 12, and the photo interrupter 12 is located at a position different from the position of the photo reflector 4 in the first embodiment. The shutter base plate 1 is disposed between the shutter base plate 1 and the shutter base plate 1.
It is attached with a screw. Further, at this arrangement position, in order to enable both the leading blade 10 and the trailing blade 11 to block the optical path between the light emitting portion and the light receiving portion of the photo interrupter 12, the slit forming blade 11a of the trailing blade 11 is formed.
Has a shape extending downward. The rest of the configuration is exactly the same as in the case of the first embodiment, so description will be omitted.

As is well known, since the electromagnets described above are arranged laterally on the left side of the exposure opening 1a, the printed wiring board is also usually arranged in the vicinity thereof. Therefore, it is preferable that the photoelectric detecting means is also arranged in the vicinity thereof as in the first embodiment. However, the photo reflector can be arranged at this position, but the photo interrupter cannot be arranged. This is because at least the front blade group interferes in order to detect the operation of the front blade group and the rear blade group by one detecting means. Therefore, when using the photo interrupter,
It is preferable to dispose it at a position where it does not interfere with both the leading blade 10 and the trailing blade 11, that is, the position shown in each drawing of the second embodiment. Needless to say, a photo reflector can be arranged at this position.

The set operation of this embodiment is exactly the same as that of the first embodiment. Also, the operation stroke at the time of release is basically the same as that of the first embodiment. FIGS. 6, 7, and 8 of this embodiment are shown in FIGS.
5 shows the same state as that of FIG. 4. for that reason,
Also in this embodiment, the time chart of FIG. 5 can be applied as it is, and therefore detailed description of the operation is omitted. The feature of the present embodiment is that the photo interrupter can be used as described above when the photoelectric detection means is arranged at the position shown in the figure, and in addition to the arrangement position of the first embodiment, another shutter configuration is used. There is no restriction on the placement of parts.

Although each of the above-described embodiments has been described as a direct type focal plane shutter, the present invention can be similarly applied to a locking type focal plane shutter, and similar effects can be obtained. .

[0026]

As described above, according to the present invention, it is possible to detect both the abnormal operation of the leading blade group and the abnormal operation of the trailing blade group by providing only one photoelectric detecting means, and moreover, chattering. It is extremely effective without the possibility of causing
Further, the detecting means can also be used as the detecting means for flash light emission.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment of the present invention, showing a set state of shutters.

FIG. 2 is a sectional view of a main part of the first embodiment.

FIG. 3 is a plan view of the first embodiment, showing the middle of traveling of the front blade group.

FIG. 4 is a plan view of the first embodiment, showing a state where the rear blade group has abnormally operated.

FIG. 5 is a time chart showing the operation of the first embodiment.

FIG. 6 is a plan view of a second embodiment of the present invention, showing a set state of shutters.

FIG. 7 is a plan view of the second embodiment, showing the middle of traveling of the front blade group.

FIG. 8 is a plan view of the second embodiment, showing a state in which the rear blade group has abnormally operated.

[Explanation of symbols]

 Reference Signs List 1 shutter base plate 1a exposure opening 1b, 1c, 2a, 6a, 8a holes 1d, 1e, 1f, 1g, 1h, 1i axis 2 intermediate plate 3 cover plate 4 photoreflector 4a light emitting part 4b light receiving part 5 reflection sheet 6,7, 8, 9 Arm 10 Front blade 10a, 11a Slit forming blade 11 Rear blade 12 Photo interrupter

Claims (4)

[Claims] 1. A front blade group formed by supporting a plurality of blades by a plurality of arms, and a front blade that is operable by releasing a front blade iron piece member by a front blade electromagnet, and the operation causes the front blade group to travel for exposure. Rear blade drive for driving the driving member, the rear blade group in which a plurality of blades are supported by a plurality of arms, and the rear blade iron magnet member released by the rear blade electromagnet to enable operation of the rear blade group for exposure travel. The member and the photoelectric detection means arranged in a position where the optical path is not blocked by the front blade group and the rear blade group in the shutter set state, and the optical path is blocked by both the front blade group and the rear blade group during exposure traveling. In the shutter release, the optical path of the photoelectric detecting means is blocked before the exposure traveling start signal is transmitted to the electromagnet for the leading blade and / or the electromagnet for the trailing blade. Therefore, the focal plane shutter is characterized in that the abnormal operation of the front blade group and / or the rear blade group is detected. 2. The detection means is arranged at a position near one side of an exposure opening to which each of the arms is attached, and the optical path is blocked by the arms or blades of the leading blade group and the trailing blade group. The focal plane shutter according to claim 1, wherein the focal plane shutter is configured as described above. 3. The blade of the leading blade group and the trailing blade group is arranged at a position in the vicinity of a side opposite to one side position of the exposure opening to which each of the arms is attached, and the detection unit. The focal plane shutter according to claim 1, wherein the optical path is blocked by the optical path. 4. The focal plane shutter according to claim 1, wherein the detecting unit also serves as a unit for outputting a flash tuning signal.