US3741091A

US3741091A - Single blade electric shutter

Info

Publication number: US3741091A
Application number: US00209045A
Authority: US
Inventors: H Ohmura
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1970-12-17
Filing date: 1971-12-17
Publication date: 1973-06-26
Anticipated expiration: 1990-06-26
Also published as: DE2161036A1

Abstract

A single blade electric shutter for opening and closing a camera aperture, comprising a first movable release lever, a second movable release lever in parallel relation to the first lever, and springs for urging the release levers in a first direction. A shutter blade is pivotally connected to the first and second levers and is movable to an open position when the first lever is moved in the first direction relative to the second lever. A locking member is mounted on a movable release rod and is adapted to engage the first lever to maintain it in a first position against the urging force of the spring. When the release rod is moved in a predetermined direction, the locking member is released from the first lever. A locking assembly is adapted to engage and disengage the second lever to control the shutter speed, and a time constant electric circuit is connected to the locking assembly to control its actuation.

Description

Ohmura [5 1 SINGLE BLADE ELECTRIC SHUTTER [75] Inventor: lliroshi Ohmura, Minato-ku, Tokyo,

Japan 73 Assignee: Fuji Photo Film Co., 1.16.,

Kanagawa, Japan [22] Filed: Dec. 17, 1971 [21] Appl. No.: 209,045

[30] Foreign Application Priority Data Dec. 17, 1970 Japan 45/126324 [52] US. Cl. 95/59 [51] Int. Cl. G03b 9/10 [58] Field of Search. 95/53 E, 55, 59

[56] References Cited I UNITED STATES PATENTS 2,978,970 4/1961 Fahlenberg 95/63 X 3,241,471 3/1966 Burgarella, 95/55 FOREIGN PATENTSOR APPLICATIONS 78,318

11/1894 Germany 95/59 Primary Examiner-John M. Horan Attorney-Richard C, Sughrue, Donald E. Zinn et al.

57 ABSTRACT A single blade electric shutter for opening and closing a camera aperture, comprising a first movable release lever, a second movable release lever in parallel relation to the first lever, and springs for urging the release levers in a first direction. A shutter blade is pivotally connected to the first and second levers and is movable to an open position when the first lever is moved in the first direction relative to the second lever. A locking member is mounted on a movable release rod and is adapted to engage the first lever to maintain it in a first position against the urging force of the spring. When the release rod is moved in a predetermined direction, the locking member is released from the first lever. A locking assembly is adapted to engage and disengage the second lever to control the shutter speed, and a time constant electric circuit is connected to the locking assembly to control its actuation.

6 Claims, 3 Drawing Figures SINGLE BLADE ELECTRIC SHUTTER BACKGROUND OF THE INVENTION The present invention relates to a single blade type electric shutter for cameras.

A single blade type shutter has been known in the art to make the construction of the photographic camera simple. Most of the single blade type photographic shutters have been of the mechanical type. Since the single blade type shutters are to be used in a simple 'camera in most cases, the construction thereof is preferred to be as simple as possible.

SUMMARY OF THE INVENTION The primary object of the present invention is to pro vide a single blade type shutter which is of extremely simple construction.

Another object of the present invention is to provide a single blade type shutter utilizing an electromagnet to further simplify the construction thereof.

A further object of the present invention is to provide a single blade electric shutter which can be manufactured at very low cost.

In order to accomplish the above objects of the invention, two release levers are provided in parallel with each other to which a single shutter blade is pivotally mounted. One of the levers is released by pressing a release rod down, and the other of the levers is released by energizing an electromagnet which is connected in a time constant circuit acting in response to exposure value.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 is a view similar to FIGS. 1 and 2, showing the state in which the shutterblade is closed.

DESCRIPTION OF THE PREFERRED EMBODIMENT Now referring to the drawing, the reference numeral 1 indicates a shutter blade which is mounted to a first release lever 2 and a second release lever 3 at

pivots

4 and 5, respectively.

The levers 2, 3 are each provided with a hook 6, 7

and connected with a tension spring 8, 9, respectively, so as to be urged to the left as seen in the drawings. The reference numeral 10 indicates a bent portion provided at the left end of the lever 2 which'serves to align both of the levers 2, 3.

a shutter release rod 12 is provided with a hook lever 11 which is pivotally mounted thereto and engaged with the hook 6. The hook lever 11 is biased in the clockwise direction by a spring 11a. The reference numeral 12 indicates a tension spring urging the shutter release rod 12 upwardly. A hook lever or latching means 13 is pivotally disposed in a position to be engaged with the hook 7 of the second lever 3. The hook lever 13 is urged in the counterclockwise direction by a tension spring 16 and is adapted to be rotated in a clockwise directionby an electromagnet 14. When the hook lever 13 is in its extreme right position, it is in engagement with the hook 7 of the second lever 3.

In FIG. 1, the shutter blade 1 closes the aperture 15 with the first and second levers 2 and 3 located in the right extremity engaged'with'the hook levers l1 and 13 at the hooks 6 and 7, respectively. When the shutter rod 12 is pressed downwardly from the state of FIG. 1, the hook 11 is also moved downwardly and released from the hook 6 of the first lever 2. Accordingly, the first lever 2 is moved leftward by the tension of the spring 8 to move the pivot 4 leftward. Thus, the shutter blade 1 isopened as shown in FIG. 2. The direction of movement of the lever 2 and the blade 1 is indicated by arrows.

At the time when the shutter release rod 12 is pressed downwardly, the magnet 14 is madeconductive and attracts the hook lever 13 to keep the hook lever 13 in its engaging position as shown in FIG. 2. When the first lever 2 is moved to its right extremity, the time constant circuit (not shown) is closed. The time constant circuit is well known in the photography field in which the exposure is made automatically in response to the illumination condition and other factors to determine the exposure value. Such time constant circuits are disclosed in United States Pat. Nos. 3,326,103 and 3,205,795. I

When the time constant circuit is closed, charging of a capacitor in the circuit is started. The period for which the capacitor is charged is determined by the sensitivity of the film and brightness of illumination and other factors affecting the right shutter speed. When the charging of the capacitor is finished, the magnet 14 is deenergized and the hook lever 13 is rotated counterclockwise by the force of the spring 16. Thus, the hook lever 13 is disengaged from the second lever 3. Then, the second lever 3 is moved leftward by the tension of the spring 9. Accordingly, the shutter blade 1 is rotated clockwise to close the aperture 15 as shown in FIG. 3. Since the shutter blade 1 is displaced from the initial position as shown in FIG. 1 when it is in its final position as shown in FIG. 3, the shape of the shutter blade I is required to have a laterally extending large portion la to close the aperture 15. i

In order to charge the shutter mechanis mafter it is released, a shutter charging lever 17 is moved rightward to move the. first shutter release lever 2 rightward. An erected edge portion 2a of the first release lever 2 is pushed by the shutter charging lever 17.

What is claimed is:

1. A single blade electric shutter comprising a first release lever, a second release lever slidably supported in parallel relation with said first release lever, mechanical biasing means for solely urging said release levers in a first direction, a shutter blade pivotally connected gaging and disengaging said second release lever for determining the shutter speed, and an electric time constant circuit controlling the period for actuating said engaging and disengaging means, whereby said shutter blade is mechanically movedsolely by said mechanical bearing means to open and close the aperture of the 3 wherein said second release lever has a hook portion for engagement with said hook lever.

5. A single blade electric shutter as defined in claim 1 wherein means is provided to align said first and second release levers when said shutter blade is in a shutsaid second lever for controlling the time period said shutter blade is in the open position, and electric time constant circuit means for controlling the actuation of said engaging and disengaging means.

Claims

1. A single blade electric shutter comprising a first release lever, a second release lever slidably supported in parallel relation with said first release lever, mechanical biasing means for solely urging said release levers in a first direction, a shutter blade pivotally connected to said release levers, means for maintaining said first release lever in a first position against the force of said urging means, a shutter release rod for releasing said first release lever from said maintaining means when said rod is moved in a predetermined direction, electromagnetic controlled mechanical latching means for engaging and disengaging said second release lever for determining the shutter speed, and an electric time constant circuit controlling the period for actuating said engaging and disengaging means, whereby said shutter blade is mechanically moved solely by said mechanical bearing means to open and close the aperture of the camera in respoNse to the actuating of said shutter release rod and the time constant.

2. A single blade electric shutter as defined in claim 1 wherein said first release lever is provided with a hook portion, and said maintaining means comprises a hook lever mounted on said shutter release rod for engagement with said hook portion of said first release lever.

3. A single blade electric shutter as defined in claim 1 wherein said electromagnetic controlled mechanical latching means for engaging and disengaging said second release lever comprises a hook lever urged in the releasing direction, and an electromagnet for effecting engagement of said hook lever with said second lever.

4. A single blade electric shutter as defined in claim 3 wherein said second release lever has a hook portion for engagement with said hook lever.

6. A single blade electric shutter comprising a first movable release lever, a second movable release lever disposed in parallel relation to said first lever, mechanical biasing means for solely urging said release levers in a first direction, a shutter blade pivotally connected to both said first and second levers and movable to an open position when said first lever is moved in the first direction relative to said second lever, a movable shutter release rod, means for engaging said first lever to maintain it in a first position against the force of said urging means, said engaging means being released from said first lever when said release rod is moved in a predetermined direction, electromagnetic controlled mechanical latching means for engaging and disengaging said second lever for controlling the time period said shutter blade is in the open position, and electric time constant circuit means for controlling the actuation of said engaging and disengaging means.

6. A single blade electric shutter as defined in claim 1 wherein means is provided to align said first and second release levers when said shutter blade is in a shutter-closed position.