JPS6218525A - Focal plane shutter - Google Patents

Abstract

PURPOSE:To form a simply constructed focal plane shutter by retreating a following sector at a position where an aperture is opened at the early stage in the return stroke of a charge member caused by a shutter release. CONSTITUTION:When a release operation is executed, initially the stopper means of the charge member 18 is released and begins to rotate in the right direction by a spring 19. In the initial stroke of the right rotation and return of the charge member 18, the locking part 18c of the charge member 18 unlocks from a part to be locked 8b of the 1st following sector driver lever 8. Therefore the 1st following sector drive lever 8 immediately rotates in the right direction by a spring 12, and a drive pin 8a reaches a position where it abuts on the other end part of an arc-like groove 1d. As a result, the following sector interlocking with the drive pin 8a through a known operational lever is brought into a position where the aperture 1a is closed from a position where it is opened. Almost at the same time, the charge member 18 returns to the state where a boss 18d abuts on the other end part of an arc-like groove 1c.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a focal plane shutter for a camera, and in particular, for example, a motor is built into the camera, and a (shutter) charge member is charged by the motor immediately after photographing is completed. The present invention relates to a focal plane shutter suitable for use in such a configuration.

[Background of the invention]

In recent years, the number of cameras with built-in motors has increased in order to automate camera winding, and in SLR cameras with built-in motors that use focal plane shutters,
In addition to winding the film and charging the shutter, the motor also charges the mirror mechanism, etc. Therefore, in this type of camera with a built-in motor,
In order to charge each of the above-mentioned mechanisms with a small battery-driven motor, it is necessary to reduce the weight of each mechanism and the amount of charge of each mechanism.

For this reason, in focal plane shutters, the moment of inertia of the drive section is reduced in an attempt to reduce the weight of the blades, thereby reducing the amount of force without reducing the curtain speed (blade operating speed). However, when trying to reduce the weight of the blade,
It is unavoidable to reduce the area of each blade, and the amount of overlap between the blades decreases, causing a problem of light leakage.

[Prior art and its problems]

In order to deal with the above-mentioned problems caused by light leakage, a focal plane shutter was proposed in Japanese Patent Publication No. 59-21536, in which the aperture (photographing opening) is closed by both the leading blade and the rear blade except when photographing. There is. However, in the configuration shown in this prior application, the leading blade moves from the open position to the closed position at the end of the shutter operation in conjunction with a series of shutter operations from the shirt release to the end of photography. Therefore, the message is complicated. In addition, in cameras with a built-in motor, the motor operates immediately after shooting ends to charge the shutter, advance the film, etc., so the charging operation of the (shutter) charging member can block the leading blade. It is sufficient to adopt a reasonable operation mode to bring the shutter to the position, and there is no need to move the leading blade to the closed position at the end of the shutter operation, independently of the charging member, as in the previous application.

[Purpose of the invention]

Therefore, it is an object of the present invention to solve the above-mentioned conventional drawbacks and to be suitable for use in a camera in which shutter charging, etc. is performed by a motor drive, so that the leading blade and the trailing blade are To provide a focal plane shutter with a simple configuration that closes an aperture.

[Summary of the invention]

The above object of the present invention is to provide a focal plane shutter in which a leading blade retracts to a position where an aperture is opened and a photographing operation ends with a trailing blade closing the aperture.
Due to the charging operation of the charging member, the leading blade moves to the closing position and closes the aperture together with the trailing blade, and is maintained in this state.
-9 This is generally achieved by arranging the rear blade to retreat to a position where the aperture is opened at the beginning of the return stroke of the charge member.

[Embodiments of the invention]

The details of the present invention will be explained below with reference to an embodiment of the present invention shown in FIGS. 1 to 7. Each figure is a plan view of the main part showing the same part. Figure 1 shows the state immediately after shooting (exposure), Figure 2 shows the state in the middle of charging, and Figure 3 shows the state just before charging is completed.
Figure 4 shows the state at the time of shooting when the charging member □ reaches the overcharge position and is maintained at this position, Figure 5 shows the initial return process of the charging member when the shirt is released, and Figure 6 shows the start of photography (exposure). FIG. 7 shows the immediately previous state, and FIG. 7 shows the state during exposure. In addition, in FIGS. 2 to 7, the aperture and each spring shown in FIG. 1 are omitted from illustration.

In the figure, 1 is the main plate of the shutter, and the aperture la1
Also, arcuate grooves 1b and 1d are bored. 2
is a forward drive lever which is rotatably held on a shaft 3 and given a left-handed rotation behavior (counterclockwise rotation bias behavior) by a spring 4, and which connects the drive pin 2a, the set roller 2b, and the engaged roller 2b. It is provided with a stop part 2C. In the state shown in the first diagram, the forward drive lever 2 has its drive pin 2a in the arcuate groove 1.
The drive pin 2a abuts against the end of the drive pin 2a and prevents further left rotation.
The leading blade (not shown) is driven through the
At this time, it is in the open position, retracted from the aperture 1a.

Reference numeral 5 denotes a first locking lever that is rotatably held on a shaft 6 and given a clockwise rotational behavior (clockwise rotational biasing behavior) by a spring 7, and is a locked portion 2C of the first drive lever 2. It is provided with a locking part 5a for locking and a boss 5b.

The rotation range of the first locking lever 5 is restricted by a stopper (not shown), and can only rotate between the position shown in the first drawing and the position shown in the second drawing. (In addition, in the state shown in FIG. 1, the first locking lever 5 should be understood to be in a transitional state in which it has rotated to the left against the spring 7.) 8 is a first lever rotatably held on a shaft 9. The rear drive lever includes a drive pier 8a, a locked portion 8b, and an engaged portion 8C. Reference numeral 10 denotes a second rear drive lever which is rotatably held on the same shaft 9 as the first rear drive lever 8 and is rotatable separately from the first rear drive lever 8, and is given left-handed rotation by a spring 11. An engaging portion 10a and a locked portion 10b are provided. Reference numeral 12 denotes a spring whose one end is moored to the first rear drive lever 8 and the second rear drive lever 10, respectively, so that the engaging portion 10a of the second rear drive lever 10 is connected to the first rear drive lever 8 and the second rear drive lever 10. A tensile force is applied between both members 8 and 10 in the direction of abutting the engaged portion 8C of the drive lever. In the state shown in the first figure, the second rear drive lever 10 with its engaging portion 10a in contact with the engaged portion 8C is rotated to the left by the force of the spring 11 together with the first rear drive lever 8. The drive pin 8a of the first rear drive lever 8 is aligned with the arcuate groove 1.
By abutting the end of d, both levers 8.10 are prevented from further turning to the left. In addition, the drive bin 8a
The rear blade (not shown) is driven in a known manner through an operating lever (not shown), and in the state shown in FIG. 1, the rear blade is in a closed position covering the aperture.

Reference numeral 13 denotes a rear locking lever that is rotatably held on a shaft 14 and given right-turning behavior by a spring 15, and is a locking lever for locking the locked portion 10b of the second rear drive lever 10. It includes a portion 13a and a boss 13b. Similarly to the first locking lever 5, the rotation range of the rear locking lever 13 is restricted by a stopper (not shown), and the rear locking lever 13 can rotate only between the first illustrated position and the second illustrated position. It is possible. (In the state shown in FIG. 1, the rear locking lever 13 should be understood to be in a transitional state in which it is rotated to the left against the spring 15.) 16 is rotatably held by the shaft 14 and rotated to the left by the spring 17. A cam portion 16a that can engage with the drive pin 2a of the optically driven lever 2, which is a rear drive holding lever that has been given a habit.
and a locking portion 16b that can engage with the locked portion 8b of the first rear drive lever 8. After this, drive maintenance 1, I
In the state shown in the first figure, the J lever 16 is in contact with the stopper bin 1e installed on the base plate l and is prevented from turning any further to the left, and the locked part 8b is in contact with the locking part 16b of the J lever 16. are in contact with each other.

Reference numeral 18 denotes a charging member rotatably held on the shaft 14 and given right-handed rotation by a spring 19, and a cam portion 18 that can engage with the set roller 2b of the optically driven lever 2.
a, a set roller 18b that can engage with the second rear drive lever 10, a locking part 18C that can come into contact with the locked part 8b of the first rear drive lever 8, and a boss 18d. A protrusion 18e is provided. In the state shown in the first drawing, the charging member 18 is in a state where its boss 18d abuts against the end of the arcuate groove IC and is prevented from turning any further to the right.

The operation of the above-described configuration will be explained below. As mentioned above, Figure 1 shows the state immediately after shooting (exposure) is completed.
The control circuit system inside the camera recognizes the end of this exposure and immediately gives a drive command to the motor inside the camera to start winding the film and charging the mirror mechanism system, and at the same time sends a drive command to the motor inside the camera through an appropriate transmission means (not shown). The rotation of the motor is transmitted to the charging member 18, and the charging member 18 begins to rotate to the left.

As the charging member 18 rotates to the left, the cam portion 18a of the charging member 18 contacts the sowing roller 2b of the light drive lever 2d, and its set roller 18b contacts the second rear drive lever 10, respectively. As shown in FIG. 2, first, the drive lever 2 and the second rear drive lever 10 begin to be rotated to the right. At this time, the first rear drive lever 8, which is connected to the second rear drive lever 10 by the spring 12, has its locked portion 8b in contact with the locking portion 16b of the rear drive holding lever 16. state, so the second
The rear drive lever 10 is prevented from turning to the right following the rear drive lever 10.

When the charging member 18 further rotates to the left from the state shown in FIG.
As a result, the light drive lever 2 and the second rear drive lever lO, which are respectively rotated to the right, reach the position shown in the third figure, and the locked portion 2C of the light drive lever 2 engages with the locking portion 5a of the first locking lever 5. At the same time, the locked portion 10b of the second rear drive lever 10 engages with the locking portion 13a of the rear locking lever 13.
, both 2 and ]0 are moored with their own springs 4 and 11 charged. Then, by turning the optically driven lever 2 to the right, the leading blade interlocked therewith is brought to the closed position covering the aperture 1a by θ,000.

Further, as the light drive lever 2 is rotated to the right, the drive pin 2a of the first drive lever 2 comes into contact with the cam portion 16a of the rear drive holding lever 16, as shown in FIG. Although the holding lever 16 is rotated slightly to the right to disengage the locking portion 16b of the rear drive holding lever 16 from the locked portion 8b of the first rear drive lever 8, at this point the charging member 18 is Since the locking portion 18C is rotated counterclockwise to a position facing the locking portion 8b, the first rear drive lever 8 is rotated clockwise by the locking portion 8b coming into contact with the locking portion 18C. is being prevented.

From this state, the charging member 18 is further rotated slightly to the left and reaches the position shown in FIG. 4. At this point, the control circuit system inside the camera stops driving the charging member 18 by the motor, and the charging member 18 is This position is held by stopper means. That is, the charging member 18
is held at the so-called overcharge position against the spring 19 which acts to rotate it to the right. At this point, as shown in the figure, the locking portion 18C of the charging member 18 is in contact with the locked portion 8b of the first rear drive lever 8, so the first rear drive The lever 8 is prevented from rotating to the right, and as described above, the rear blade that is interlocked with the first rear drive lever 8 is in a state where the aperture 1a is closed.

Since the transition to the state shown in the fourth diagram occurs immediately after the end of the photographing, the aperture 1a immediately shifts to a state in which it is doubly blocked by the leading blade and the trailing blade, leading to the next photographing. Until then, the light shielding measures for the aperture 1a are nearly perfect. .

When a release operation is performed from the state shown in the fourth figure, the stopper means of the charging member 18 (not shown) described above is released, and the charging member 18 begins to rotate clockwise by the spring 19 as shown in the fifth figure. This charge member 1
In the initial stroke of clockwise rotation and return in step 8, the charging member 18
The locking portion 18C is the locked portion 8b of the first rear drive lever 8.
The first rear drive lever 8 is immediately turned to the right by the spring 12 described above, and reaches a position where its drive pin 8a is in contact with the other end of the arcuate groove 1d, as shown in the figure. As a result, the rear blade, which is interlocked with the driving pier Ba via a known operating lever, is brought from the position where the aperture 1a is closed to the position where it is opened. At the beginning of the clockwise rotation/return stroke, the charging member 18 whose rear blades have been retracted to the open position as described above also moves at the same time, as shown in FIG. It returns to the state shown in FIG. 1 described above in which it is in contact with the end.

Subsequently, in response to a release signal based on the release operation, the first locking lever 5 is activated by appropriate electromagnetic means as is known in the art.
When the optically driven lever 2 is rotated to the left and the mooring of the optically driven lever 2 is released, the optically driven lever 2 is quickly rotated to the left by the aforementioned spring 4 as shown in FIG. from the closed position to the open position.

Also, the appropriateness (desired) of this optically driven lever 2 after unmooring.
At the same time, the rear locking lever 13 is rotated to the left by an appropriate electromagnetic means or the like, and the second rear drive lever 1 is rotated to the left.
0 is released, the second rear drive lever 10 rapidly rotates to the left together with the first rear drive lever 8 by the spring 11 described above, and the second rear drive lever 10 rapidly rotates to the left through the first rear drive lever 8 and the operating lever. When the interlocking rear blades are brought from the open position to the closed position, exposure (photography) is completed, and all members are returned to the state shown in FIG. 1 described above.

〔Effect of the invention〕

As described in detail above, the present invention is suitable for use in a camera in which shutter charging and the like are performed by a motor; It is possible to provide a focal plane shutter with a simple configuration and a high light-shielding effect in which both the leading blade and the trailing blade close the aperture except during shooting and shutter charging operations, and its value is high.

[Brief explanation of drawings]

The drawings are all plan views of essential parts of a focal plane shutter according to an embodiment of the present invention, with Fig. 1 showing the state immediately after photographing (exposure) is completed, Fig. 2 showing the state in the middle of charging, and Fig. 3 showing the state immediately before the completion of charging. , Figure 4 shows the state at the time of photography when the charging member reached the overcharge position and was maintained at this position.
FIG. 5 shows the initial return process of the charging member accompanying the shirt release, FIG. 6 shows the state immediately before the start of photographing (exposure), and FIG. 7 shows the state during exposure. 1... Base plate 1a... Aperture 2... Light drive lever 4... Spring 5... Tip locking lever 7... ...Spring 8...First rear drive lever 10...Second rear drive lever 11...Spring 12...Spring 13... ... Rear locking lever 15 ... Spring 16 ... Rear drive holding lever 17 ... Spring 18 ... Charging member 19 ... Spring patent application People Co/Sil Co., Ltd. Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (2)

[Claims] (1) In a configuration where the leading blade retracts to the position where the aperture is opened and the photographing ends with the trailing blade closing the aperture, the charging operation of the charging member moves the leading blade to the closing position and the rear blade closes the aperture. A focal plane shutter characterized in that the aperture is maintained in a closed state together with the blade, and the rear blade is retracted to a position where the aperture is opened at the beginning of a return stroke of the charging member accompanying shutter release. (2) The focal plane shutter according to claim 1, wherein the charging member is charged by the driving force of a motor that is activated immediately after photographing is completed.