JP3196128B2 - 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 provided with a camera screen switching mechanism for a camera shutter.

[0002]

2. Description of the Related Art As is well known, a focal plane shutter of a camera includes a pair of open blades and a closed blade. The open blade opens a shutter opening in response to a shutter release signal, and exposure is started by the open edge. On the other hand, the closing blade operates after the opening operation of the opening blade, and the exposure of the shutter opening is terminated by the closing edge thereof.

Further, there is known a screen size switching mechanism for shielding both ends of two opposing sides of a screen in order to change an exposure range of a photographic screen (Japanese Patent Laid-Open No. Hei 3-16353).
No. 9).

[0004]

However, in such a conventional focal plane shutter, after the closing blade fully closes the shutter opening with the end of exposure, the closing blade bounces to re-expose the shutter opening. In order to prevent the shutter from closing, a closing-side bounce prevention mechanism is required, and recently a particularly compact shutter is required. Therefore, the overlap distance between the shutter opening allowing the closing blade to bounce when the shutter is closed and the stop position of the closing blade. And a complicated bounce prevention mechanism is required. Also, if the blades are made compact to reduce the operating energy due to the demand for a high speed at the shutter time, the overlap between the blades is reduced, light leakage occurs, and a problem that a high-sensitivity film cannot be used occurs. . On the other hand, the screen size switching mechanism is used only for changing the exposure range of the photographing screen. In the present invention, it is an object of the present invention to provide a focal plane shutter in which a screen size switching mechanism is used also as a closing-side bounce prevention mechanism, and the blades are compact and advantageous in light leakage.

[0005]

According to the present invention, there is provided a photographing screen, an opening drive member for operating a group of open blades for opening the photographing screen, and a shutter for closing the photographing screen. A closing drive member that operates a group of closing blades, and a screen size switching mechanism that shields a part of the screen to change an exposure range of the shooting screen, wherein the closing drive member is in an operation end area of the closing drive member. A focal plane shutter is configured to switch the screen size switching mechanism to a side on which the photographing screen is shielded from light. Further, the screen size switching mechanism is a focal plane shutter that shields the entire area of the shooting screen from light.

[0006]

According to the present invention, the screen size switching mechanism switches the photographing screen to the light-shielding side in conjunction with the closing drive member in the operation end area of the closing drive member, so that the shutter opening is re-exposed even when the closing blade bounces. Never do. Further, the screen size switching mechanism shields the entire photographing screen from light, which is advantageous for light leakage.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the preferred embodiments shown in the accompanying drawings. FIG. 1 is a side view showing an embodiment of the shutter according to the present invention. In FIG. 1, a shutter opening 1a is formed in a substrate 1 disposed in front of a film 60 loaded in a camera and on the photographic lens side. On the film surface side of the substrate 1, a closing blade unit 3 for closing the shutter opening 1a is mounted, and on the film surface side of the closing blade unit 3, a partition plate 4 having a shutter opening 4a is mounted. The open blade unit 2 is placed on the film surface side of the partition plate 4. On the film surface side of the open blade unit 2, a receiving plate 5 having a shutter opening 5a is placed. The receiving plate 5 is provided with a shielding plate 10 for switching a photographing screen size and an operation lever 11 for operating the shielding plate 10.

FIG. 2 shows a rear view of the shutter with the receiving plate 5 removed in the set state. FIG. 3 is a rear view of the shutter at the time of photographing the standard screen size after the shutter release, and FIG. 4 is a rear view of the shutter after the shutter release at the time of photographing the special screen size. And
FIG. 5 shows a rear view of the shutter after the exposure operation is completed.
FIG. 6 shows a rear view of the shutter with the receiving plate 5 removed after the exposure operation is completed.

Open blade unit 2, Closed blade unit 3
Constitutes a parallel link mechanism including two arms in a known manner, and is rotatably supported by a shaft provided on the substrate 1 on the side of the shutter opening 1a so as to be freely rotatable. And the exposure operation is performed. Shielding plate 1 guided by guide pins 12 implanted in receiving plate 5
0 is actuated by an operation lever 11 pivotally supported by the receiving plate 5 to constitute a screen size switching mechanism.

The operation lever 11 is urged by a spring 11b so as to be a standard screen, and the screen switching lever 20 changes the position of a connecting pin 11a provided on the operation lever 11,
The screen size can be changed. Further, the operation lever 11 can be turned clockwise to a position where the shutter opening is completely closed by the shielding plate 10. The locking lever 30 is provided with rightward rotation by a spring 30a, and locks the connection pin 11a of the operation lever 11 of the screen size switching mechanism at the fully closed position of the shutter opening as shown in FIG.

The operation of the above configuration will now be described. First, the operation at the time of shooting a standard screen size will be described. With the film winding operation, the focal plane shutter is set to a set state by a known shutter charging mechanism. At this time, as shown in FIG. 2, the open blade unit 2 is unfolded and covers the shutter opening 1a.
The closing blade unit 3 is folded below the shutter opening 1a. The screen size switching mechanism fully closes the shutter opening 5a as shown in FIG. When the shutter release operation is performed in this state, the locking lever 30 is rotated leftward by a known method to release the locking of the connecting pin 11a, and the connecting pin 11a is restricted by the position of the screen switching lever 20 corresponding to the standard screen. Figure 3 shows the screen size switching mechanism.
The standard screen is configured as shown in. Thereafter, when the release lever 40 locked by the known locking mechanism is released, the release lever 40 is turned clockwise by the known drive spring, the opening blade unit 2 is folded, and the shutter opening is opened. Start releasing 1a. Then, after a lapse of a predetermined time, the closing lever 50 is released from the known locking mechanism similarly to the opening lever 40 and turns clockwise, whereby the closing blade unit 3 is deployed and starts closing the shutter opening 1a.

[0012] Then, as shown in FIG.
Closes the shutter opening 1a completely.
Collides with the operation lever 11, and the operation lever 11 is pushed and moved. As a result, the shielding plate 10 operates to start covering the shutter opening 5a. The closing lever 50 is decelerated by the collision with the operating lever 11, and the closing blade unit 3 completely closes the shutter opening 5a and stops. At this time, the connecting pin 11a
5 moves over the locking lever 30 near the fully closed position, is locked by the locking lever 30 as shown in FIG. 5, and the shutter opening 5a is fully closed until the next shutter operation.

Next, the operation at the time of shooting a special screen size will be described. When the shutter release operation is performed in a state where the screen switching lever 20 moves to the left and waits, the locking lever 30 releases the locking of the connecting pin 11a, but the connecting pin 11a corresponds to a special screen size. The screen size switching mechanism regulated by the position of the screen switching lever 20 configures a special screen size as shown in FIG. Others are the same as those at the time of shooting the standard screen size. At the end of the operation, the screen is fully closed as shown in FIG.

In the present embodiment, the fully closed state is set after the exposure operation is completed. However, the fully closed state is not necessarily required, and the screen size switching mechanism may simply be operated to the closed side.
In addition, the screen size switching shielding plate moves up and down the screen, but may move left and right.

[0015]

According to the present invention, since the screen size switching mechanism switches to the side where the photographing screen is shielded in conjunction with the closing lever in the operation end area of the closing lever, the photographing screen is re-exposed even if the closing blade bounces. Never do. The collision energy of the closing lever with respect to the operation lever differs between the standard screen and the special screen, resulting in a difference in the effect of preventing bouncing. However, there is no problem because the effect of the bounce of the closing blade unit is not on the photographing screen. In addition, when the operation is completed, the screen size switching mechanism is moved to the closing side, and the energy at the time of stopping the closing lever and the closing blade unit can be transferred to the movement of the screen size switching mechanism, so that the durability of the closing lever and the closing blade unit is improved. Also, after the shutter exposure operation is completed, a part or the whole of the photographing screen is double-shielded by the screen size switching mechanism and the open blade unit or the closed blade unit, which is advantageous for a high-sensitivity film. In addition, even if the overlapping amount of the blade group is reduced when the shooting screen is closed, the light shielding property is good, so that the number of blades or the size of the blade can be reduced, and the operating energy for operating the blade group can be reduced. This can reduce noise and shock, and contribute to downsizing of the shutter and the camera. Further, since the photographing screen is double-covered by the blade unit and the screen size switching mechanism, there is an effect that the photographing screen becomes strong against an external force pressing the photographing screen portion with a finger at the time of film exchange.

[Brief description of the drawings]

FIG. 1 is a side view of a shutter according to an embodiment of the present invention.

FIG. 2 is a rear view of a shutter with a receiving plate removed according to the embodiment of the present invention.

FIG. 3 is a rear view of the shutter after shutter release during standard screen shooting according to the embodiment of the present invention.

FIG. 4 is a rear view of the shutter after shutter release during special screen imaging according to the embodiment of the present invention.

FIG. 5 is a rear view of the shutter after the exposure operation according to the embodiment of the present invention is completed.

FIG. 6 is a rear view of the shutter with the receiving plate removed after the exposure operation according to the embodiment of the present invention is completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 1a Shutter opening 2 Opening blade unit 3 Closing blade unit 5 Receiving plate 12 Guide pin 10 Shielding plate 11 Operating lever 11a Connecting pin 20 Screen switching lever 30 Locking lever 40 Opening lever 50 Closing lever

Claims (2)

(57) [Claims] 1. A photographing screen, an opening drive member for operating an opening blade group for opening the photographing screen, and a closing drive member for operating a closing blade group for closing the photographing screen.
A screen size switching mechanism that shields a part of the screen to change the exposure range of the shooting screen, wherein the closing drive member shields the shooting screen from the screen size switching mechanism in an operation end area of the closing drive member. A focal plane shutter characterized by switching to the side. 2. The focal plane shutter according to claim 1, wherein the screen size switching mechanism shields the entire area of the photographing screen from light.