JP3448343B2 - Focal plane shutter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a focal plane shutter for a camera.

[0002]

2. Description of the Related Art In a focal plane shutter in which a front blade group and a rear blade group are sequentially driven by respective driving members during an exposure operation, a light shielding blade group is provided separately from the blade groups. Actual public Sho 61-11703
It is known from Japanese Utility Model Publication No. 4-53623.
Then, these light-shielding blade groups are moved to the aperture closed position in conjunction with the charging operation of the front and rear blade groups, and are moved to the aperture open position before the front blade group performs the exposure operation. It is done like this. This shading blade group is provided to prevent light from leaking from the aperture to the film surface when at least one of the leading blade group and the trailing blade group covers the aperture, and is usually provided in the camera. It is arranged between the front and rear blade groups and the film surface.

On the other hand, in recent years, in addition to standard-size image frames, many cameras have become popular which are capable of taking images with panoramic sizes having different aspect ratios and image frames of other sizes. At the present stage, all such cameras change the aspect ratio by shortening the vertical dimension of the standard size image frame. Therefore, when shooting with a panorama size image frame in a camera equipped with a focal plane shutter, if the panorama size is selected by the image frame switching device provided in the camera, the two images arranged between the shutter and the film are selected. The plate for determining the image frame intrudes into the aperture from above and below and covers a part of the front surface of the film. Such incorporating two plates of the the unit of the focal-plane shutter is considered since, JP by the applicant 6-30857
Many proposals have been made such as the inventions described in JP-A-6-308573 .

[0004]

SUMMARY OF THE INVENTION According to the present invention, as described above, both the light shielding blade group and the two image frame determining plates are arranged between the front and rear blade groups and the film surface. Focusing on the fact that it is something, the purpose is to
The third blade group is arranged at a position closer to the film surface than the front and rear blade groups, and the third blade group prevents light leakage from the aperture and determines the image frame such as a panorama size at the time of shooting. A focal plane shutter is provided.

[0005]

In order to achieve the above object, the focal plane shutter of the present invention comprises:
A first blade group to travel to where the <br/> folding open aperture position from the deployed position that closes the aperture at the time of exposure operation, a first driving means for actuating the first blades, said during the exposure operation second traveling from the collapsed position is open the aperture to the deployed position of closing the aperture
A blade group, a second drive means for operating the second blade group, a reciprocating operation setting means for moving the first and second drive means to a charging position by forward movement thereof, and the first and the second drive means. It is placed closer to the film than the two blades
Each consists of one or more blades and sandwiches the aperture
It is composed of two groups that are relatively operated in the above-mentioned manner, and is operated in the direction to close the aperture in association with the forward movement of the setting means, and the first blade group performs the exposure operation. third operating direction of opening the aperture prior
Before moving toward the blade group and opening the aperture
Serial third suppresses blade set the third blades are provided with a picture frame regulating means capable of regulating a position facing to said aperture.

[0006] In that case, each group is
Are connected to each other so as to operate relative to each other.
The image frame regulation means is associated with one of the groups.
Together, the opening operation of the aperture by both groups is suppressed.
It is preferably configured to stop. Furthermore, each group
Each of the loop vanes is pivotally attached to multiple working arms.
The image frame regulating means engages with the operating arm,
Set the above-mentioned set so as to suppress the opening operation of the aperture.
Means engages the actuating arm to close the aperture
It is preferably configured to operate.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. 1 is a front view showing a state before shutter charging, FIG. 2 is a rear view of FIG. 1, FIG. 3 is an explanatory view showing a central longitudinal section of FIG. 1, and FIG. 4 is shown in FIG. It is a principal part explanatory drawing of an auxiliary ground plane. 5 is a front view showing a completed state of shutter charging, and FIG. 6 is a rear view of FIG. Figure 7
8 and 9 are rear views showing a state immediately before the start of the exposure operation, FIG. 7 shows a case where a standard size image frame is selected, and FIG. 8 shows a case where a panoramic size is selected.

First, the structure of this embodiment will be described. Ground plate 1
The opening 1a is provided in the. As shown in FIG. 3, an auxiliary base plate 2, a light-shielding blade intermediate plate 3, and a cover plate 4 are sequentially stacked on the back of the base plate 1 and integrally attached by an appropriate method. The three plates 2, 3 and 4 are provided with openings 2a, 3a and 4a, each of which has a substantially rectangular shape, and together with the opening 1a, an exposure opening (hereinafter referred to as an aperture) is formed. A front blade group 5 and a rear blade group 6 each having four pieces are arranged between the main plate 1 and the auxiliary main plate 2. As a well-known shutter structure, another plate generally called an intermediate plate is provided between the front blade group 5 and the rear blade group 6, but it is omitted in the drawings in this embodiment.

The front blade group 5 includes the shafts 1b, 1c, 1 of the main plate 1.
It is attached to three arms 7, 8 and 9 which are pivotally attached to d. The slit forming vanes are pivotally attached to the arms 7 and 8, and the other vanes are attached to the arms 8 and 9, respectively. Rear blade group 6
Is attached to three arms 10, 11 and 12 pivotally attached to the shafts 1e, 1f and 1g of the main plate 1, the slit forming blades to the arms 10 and 11, and the other blades to the arm 1.
They are pivoted to 1 and 12, respectively. The front drive lever 13 is pivotally attached to the shaft 1c, and is provided with a right turning property by a drive spring (not shown). The drive pin 13a that is planted on the front drive lever 13 penetrates the arc-shaped slot 1h provided in the main plate 1 and is not clearly shown, but the arm 8
It is rotatably fitted in a hole provided in the. The rear drive lever 14 is pivotally attached to the shaft 1f, and is provided with a right turning property by a drive spring (not shown). The drive pin 14a that is planted on the rear drive lever 14 penetrates through the arc-shaped slot 1i provided in the main plate 1 and is rotatably fitted into a hole provided in the arm 11 though not shown. There is.
In addition, the drive levers 13 and 14 are respectively provided with the roller 1
3b and 14b are provided.

The set lever 15 is pivotally attached to the shaft 1j of the main plate 1 and is provided with a left turning property by a spring (not shown). The set lever 15 is provided with an operating portion 15a, and shafts 15b and 15c are planted. The set link 16 is pivotally attached to the shaft 15b, and in FIG. 1, the tip portion 16a contacts the large diameter portion 1f 'of the shaft 1f to prevent the set lever 15 from rotating counterclockwise. The set cam 17 is pivotally attached to the shaft 1k of the main plate 1, and the shaft 16b of the set link 16 is rotatably fitted in a hole (not shown). or,
The set cam 17 includes arm portions 17 each having a cam surface.
a, 17b are provided, and the arm portion 17a can be brought into contact with the roller 13b of the front driving lever 13, and the arm portion 1a
The roller 7b can contact the roller 14b of the rear drive lever 14.

The light-shielding link lever 18 is provided with a shaft 18a which is erected and is pivotally attached to the shaft 1m of the main plate 1. The light shielding link 19 is rotatably attached to the shaft 15c of the set lever 15 and the shaft 18a, has a bent portion 19a, and stands up the shaft 19b. The light-shielding set lever 20 is the arm 2
0a, 20b and is pivotally attached to the shaft 19b. The light-shielding set lever 20 is provided with a left-handed habit by a spring (not shown), but the arm portion 20b has a bent portion 19a.
The left turn is blocked by abutting against. The holes 1n, 1p, 1q formed in the base plate 1 are for attaching to the camera body, respectively.

The light-shielding blade group in this embodiment is divided into two groups as shown in FIG. 3, and the first light-shielding blade group 21 is provided on the back side of the light-shielding blade intermediate plate 3 and the second light-shielding blade group 2 is provided.
2 is arranged on the front side. The blade groups 21 and 22 are connected to each other as will be described later, and are arranged so as to operate symmetrically in the vertical direction with the opening 3a interposed therebetween. The first light blocking blade group 21 includes two blades 21a and 21a.
The blade 21a is pivotally attached to the tips of the arms 23 and 24, and the blade 21b is pivotally attached to the substantially central portion of the arms 23 and 24. These arms 23 and 24 are shown in FIG.
In the holes 2b and 2c of the auxiliary base plate 2 shown in FIG. 2, shafts 2d and 2e that are planted by caulking are pivotally attached. The tip of the shaft 2d also serves to support the cover plate 4. Further, the shaft 2e penetrates a hole provided in the light-shielding blade intermediate plate 3 and projects toward the back side. Therefore, the arms 23 and 24 are arranged between the light shielding blade intermediate plate 3 and the cover plate 4. A pin 23a is erected on the arm 23 toward the side of the auxiliary base plate 2 and an engaging portion 23b is formed on the arm 23. The spring (not shown) imparts a right turning characteristic in FIG.

The second light-shielding blade group 22 is also composed of two blades 22a and 23b.
The blade 22b is pivotally attached to the tip of the arm 26,
It is pivotally attached to approximately the central portion of 6. These arms 25,
Reference numeral 26 is pivotally attached to the shafts 2f and 2g which are planted on the auxiliary ground plate 2, and a spring (not shown) is stretched around the arm 26 to impart a right turning property in FIG. An inverted L-shaped light-shielding arm link 27 in FIG. 2 is arranged between the auxiliary base plate 2 and the light-shielding blade intermediate plate 3, and one end of the light-shielding arm link 27 is rotatably fitted to the pin 23a. The other end is similarly fitted to the pin 25a of the arm 25. In the auxiliary base plate 2, a shaft 2i is erected by caulking in a hole 2h shown in FIG. 4, and an image frame switching lever 28 is pivotally attached. The image frame switching lever 28 has a bent portion 28.
a is formed, the pin 28b is planted, and the spring (not shown) provides the right-handed habit in FIG. The tip of the shaft 2i serves to support the cover plate 4. Further, as shown in FIG. 4, an engaging portion 2j is formed on the auxiliary base plate 2 and engages with a pin 23a of the arm 23 so as to block the operation of the arm 23 as described later. .

Next, the operation will be described. 1 to 3 each show a state in which photographing has been completed. From this state, the shutter is charged in association with the film winding. First, the operating portion 15a is pushed by a mechanism (not shown), so that the set lever 15 turns right in FIG. 1 against its own habit of operation. Therefore, set link 1
6 moves upwards. At this time, the set cam 17 connected to the shaft 16b turns right, the arm 17a pushes the roller 13b to turn the front drive lever 13 left, and the arm 17b pushes the roller 14b to move the rear drive lever 14. Turn left. The front drive lever 13 and the rear drive lever 14 continue to rotate counterclockwise while tensioning drive springs (not shown) respectively, and the arms 7, 8, 9 and the arms 10, 11, 12 are rotated.
The respective blade groups are moved upward by the so as to be in the charged state as shown in FIG. At this time, the leading blade group 5 is in the expanded state and the aperture is closed, and the trailing blade group 6 is in the folded state and the aperture is open.

On the other hand, the light-blocking link 19 is moved leftward in FIG. 1 by turning the set lever 15 clockwise.
Therefore, the arm portion 20a of the light-shielding set lever 20 has the pin 2
Abut on 3a and push. As described above, the arm 23 and the arm 26 are respectively provided with the right-handed turning force, but since the spring force given to the light-shielding set lever 20 is stronger, the arm 23 is left-handed in FIG. To be done.
Since the movement of the pin 23a is transmitted to the arm 25 via the light shielding arm link 27, the arm 25 is also rotated counterclockwise in FIG. Therefore, the first light-shielding blade group 21 and the second light-shielding blade group 22 move relative to each other in the vertical direction to be in the expanded state and close the apertures, and the state shown in FIG. 6 is obtained.
In this state, the pin 23a is engaged with the engaging portion 2j of the auxiliary base plate 2.
(See FIG. 4) and its movement is stopped, but the set lever 15 further rotates while tensioning the spring stretched around the light-shielding set lever 20 (so-called overcharge), and as described above. Rotate the drive lever 13 and the rear drive lever 14 to the end and set them to the positions shown in FIG.
Held in that position.

The photographer selects either standard size or panoramic size prior to shooting. The position of the image frame switching lever 28 in FIG. 6 shows the case where a standard size image frame is selected. When the camera is released in this state, the front drive lever 13 and the rear drive lever 14 are first held at their positions by respective electromagnets (not shown). Next, the holding force of the set lever 15 is released, and the set lever 15 turns counterclockwise due to its own habit. By this left-handed rotation, the set cam 17 is turned leftward on the one hand, and the light-shielding link 19 is moved rightward on the other hand, and the pressing force on the pin 23a by the light-shielding set lever 20 is released. Therefore, the arms 23 and 25 are interlocked via the light-shielding arm link 27, and are rotated rightward in FIG. 6 by the spring force urging the arms 23 and 26. When the set lever 15 returns to the original position (the position shown in FIG. 1), the first light-shielding blade group 21 and the second light-shielding blade group 22 are in the state shown in FIG. 7 so that the aperture can be a standard size image frame. Open to. After that, the holding force of the electromagnet is released by the control signal from the exposure control circuit, and the front drive lever 13 and the rear drive lever 14 sequentially rotate rightward to bring the front blade group 5 into the folded state and the rear blade group 6 To the unfolded state to return to the position of FIG.

When the photographer selects a panorama size image frame prior to photographing, pin 2 of the image frame switching lever 28 is selected.
The pressing force on 8b is released, and the image frame switching lever 28 rotates clockwise in FIG. When the camera is released in this state, the set lever 15 rotates counterclockwise in FIG. 5 and the light-shielding set lever 20 moves to the right as described above. Therefore, the pin 23a of the arm 23 follows it, and the arm 23 rotates about the axis 2d. But,
Before the arm 23 reaches the standard size position described above, that is, the state shown in FIG.
8 is engaged with the bent portion 28a and its rotation is blocked. After that, the state where the set lever 15 returns to the original position is shown in FIG.
Is shown in. In this state, the blades 21a, 2
The long side of the image frame is restricted by 2a, and a panoramic size image frame that is horizontally longer than the standard size is formed. Subsequent operations are the same as the operations in the case of the standard size described above, and a description thereof will be omitted. As can be seen from the above description, it is possible to select a size other than the panorama size by appropriately changing the position where the arm 23 is restrained by the image frame switching lever 28, and the engaging portion 23 can be selected.
By forming b in multiple stages, it is possible to select a plurality of sizes other than the standard size.

In the above embodiment, the set lever 15 is held at that position until the camera is released after the front drive lever 13 and the rear drive lever 14 are set. In the well-known focal plane shutter, these drive levers 13, 1
In many cases, 4 is locked by separate members at the set position, that is, the charging position. Therefore, when applied to such a type of shutter, the set lever 15 is immediately returned to the original position after the setting operation. You may allow it. However, in that case, either the light-shielding link 19 or the light-shielding set lever 20 which constitutes the setting means of the light-shielding blade groups 21 and 22 together with the set lever 15 may be stopped at the positions shown in FIGS. It is necessary to separately provide a locking member that can be used and release the locking of this locking member when the camera is released. In that case, the set lever 15 and the light-shielding link 19 are also connected to each other by, for example, pin-slot connection and a spring is stretched between them, so that the light-shielding link 19 is integral with the set operation of the set lever 15. It is necessary to make it possible to perform the return operation by the spring force. Further, in the above-described embodiment, the light shielding blade group is divided into the first light shielding blade group 21 and the second light shielding blade group 22, but the first light shielding blade group 21 unless the image frame is changed at the optical axis center. You can use it alone. Further, the first light-shielding blade group 21 and the second light-shielding blade group 22 are not connected by the light-shielding arm link 27, and the setting of both blade groups individually by the setting means is not hindered.

[0019]

As described above, when the light-shielding blade group is conventionally installed in addition to the front blade group and the rear blade group, it is difficult to install the image frame switching mechanism, and it is assumed that the image frame switching mechanism can be installed. However, there is a problem in that the shutter size in the optical axis direction of the camera is increased and the cost is increased.
Since the two blade groups are also used, the above problems are solved and the effect is extremely large.

[Brief description of drawings]

FIG. 1 is a front view showing a state before shutter charging according to an embodiment of the present invention.

FIG. 2 is a rear view of FIG.

FIG. 3 is an explanatory view showing a central longitudinal section of FIG.

FIG. 4 is an explanatory view of a main part of an auxiliary base plate 2 in the embodiment.

FIG. 5 is a front view showing a completed state of shutter charging in the embodiment.

FIG. 6 is a rear view of FIG.

FIG. 7 is a rear view showing a state immediately before the start of an exposure operation when a standard size image frame is selected.

FIG. 8 is a rear view showing a state immediately before the start of an exposure operation when a panoramic size image frame is selected.

[Explanation of symbols]

1 Base plate 2 Auxiliary base plate 3 Light-shielding blade intermediate plate 4 Cover plate 5 Front blade group 6 Rear blade group 7, 8, 9, 10, 11, 12, 23, 24, 25, 2
6 arm 13 front drive lever 14 rear drive lever 15 set lever 16 set link 17 set cams 17a, 17b, 20a, 20b arm 18 light blocking link lever 19 light blocking links 19a, 28a bent portion 20 light blocking set lever 21 first light blocking blade Group 22 Second light-shielding blade group 23a Pin 23b Engaging portion 27 Light-shielding arm link 28 Image frame switching lever

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-142621 (JP, A) JP-A-5-142622 (JP, A) JP-A-5-313227 (JP, A) Actual development Sho-56- 55819 (JP, U) Actual development Sho 62-151526 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03B 9/08-9/54

Claims (3)

(57) [Claims] 1. A first actuating the deployed position that closes the aperture at the time of exposure operation and the first blade group to travel to the collapsed position which opens the aperture, the first blade set
A drive means, a second blade group to travel from the collapsed position is open the aperture during exposure operation to the deployed position closing said aperture, and a second driving means for actuating the second blades, can reciprocate And the setting means for moving the first and second drive means to the charging position by the forward movement, and the film surface side from the first and second blade groups.
The above-mentioned apertures are arranged and each comprises one or more blades.
Consists of two groups that operate relative to each other
Is the UPPER <br/> is actuated in the direction of closing the tea the first blades in conjunction which the forward movement of the set means is actuated in the direction of opening the aperture prior to performing the exposure operation Third blade group and direction to open the aperture
Operated to the third suppresses blade set said third blade unit is pre
An image frame restricting means capable of restricting the position facing the aperture,
A focal-plane shutter comprising: 2. Each of the groups sandwiches the aperture.
Are connected to each other so as to operate relatively,
The image frame restricting means is engaged with one of the groups to engage both groups.
To prevent the opening of the aperture by the loop
The focal pre according to claim 1, characterized in that
Shutter. 3. The blades of each group have a plurality of operations, respectively.
It is pivotally attached to the arm, and the image frame restricting means operates as described above.
Engage with an arm to prevent opening of the aperture
And the setting means engages with the actuating arm.
The fact that the closing operation of the aperture is performed
The focal plenity according to claim 1 or 2,
Chatta.