JP2536845Y2 - Aperture drive - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a diaphragm drive device, more specifically, a diaphragm drive comprising a thin diaphragm plate used in an electronic still camera or a normal camera using a silver halide film. It concerns the device.

2. Description of the Related Art Conventionally known diaphragm devices include a so-called iris diaphragm type in which a plurality of diaphragm blades are rotated with a wheel to form a diaphragm opening, as is well known in the art. A plurality of aperture openings having different aperture diameters are sequentially drilled at equal intervals on a single disk or a single strip-shaped thin plate, and the apertures are moved on the exposure optical path in a turret type or a slide type to form an aperture. And a diaphragm plate moving type.

The iris diaphragm type has a complicated structure, a large number of parts, and a poor precision in forming an aperture diameter.
The above-mentioned diaphragm moving type has a merit that the aperture diameter accuracy is good and the structure is simple because a plurality of diaphragm apertures having different aperture diameters are previously formed in one thin plate. It is used favorably for cameras having a small screen size such as electronic still cameras. For example,
Japanese Patent Publication No.-125921 discloses a diaphragm plate moving type in which a plurality of diaphragm apertures having different aperture diameters are drilled at equal angular positions on one sector-shaped disc and driven in a turret type. The above-mentioned diaphragm device is applied to an electronic still camera. Japanese Patent Laid-Open Publication No. Sho 63-218929 discloses that the diaphragm aperture of the diaphragm plate moving type diaphragm device is arranged in large, small and large sizes. Technical means for preventing the occurrence of ghosts, flares, and the like on the photographing screen due to this are disclosed.

The applicant has also previously used this type of aperture device, as a type of aperture device, using a diaphragm plate provided with apertures having different aperture diameters on both sides of an aperture located on the imaging optical path, and using the same aperture plate. Japanese Patent Application No. 63-330671 (JP-A-2-173730) has proposed a diaphragm device which can be rotated clockwise or counterclockwise so that a desired diaphragm aperture can be set at the shortest distance.
No.).

[Problems to be Solved by the Invention] However, in the conventional turret type diaphragm device provided with a plurality of diaphragm openings having different aperture diameters in a single diaphragm plate,
When displacing the diaphragm plate to dispose the desired diaphragm opening on the optical axis, as the diaphragm opening is displaced to the operating position on the optical axis, the other diaphragm openings and the perforated plate portions are also the same amount. Because of the displacement, there is a drawback that an extra space for allowing the displacement must be taken at the position where the aperture is provided, which has a disadvantage that the camera becomes large.

The purpose of the present invention is to eliminate the above-mentioned conventional disadvantages.
An object of the present invention is to provide a diaphragm driving device in which, among the diaphragm openings formed in the diaphragm plate, those not used at that time are not displaced due to the rotational displacement of the used diaphragm opening.

[Means and Actions for Solving the Problems] An aperture driving device according to the present invention is provided with a first aperture plate that is rotatably displaceable and has a predetermined first aperture opening. A second diaphragm plate having a common rotation center with the plate and being provided so as to be rotationally displaceable independently of the first diaphragm plate, and having a predetermined second diaphragm opening; A first driving force transmitting mechanism for transmitting a driving force in the first rotational displacement direction so as to displace the diaphragm plate in the first rotational direction and stop at the operating position; and the second diaphragm A second driving force for transmitting a driving force in the second rotational displacement direction so as to displace the plate in a second rotational direction opposite to the first rotational direction and to stop the plate at the operation position. A transmission mechanism, provided in common with the first and second driving force transmission mechanisms, The power transmission mechanism,
A third driving force transmitting mechanism for transmitting the rotational driving force of the driving source; and a third driving force transmitting mechanism connected to the third driving force transmitting mechanism, the third driving force transmitting mechanism being operated by a current corresponding to the photometric exposure value, and
A single driving source that generates a rotational driving force in the direction of rotation of the drive source, and an elastic member that stores a rebound elastic force by the rotational driving force of the driving source. The first diaphragm plate or the second diaphragm plate is moved back to the initial position by the opening elasticity of the rebound elasticity stored in the elastic member.

Hereinafter, the present invention will be described with reference to the illustrated embodiments.

1 and 2 show an aperture driving device according to an embodiment of the present invention. FIG. 1 is an exploded perspective view thereof, and FIG. 2 is a longitudinal sectional view of a main part. In this embodiment, a current corresponding to the measured exposure value is applied to an aperture driving source, and a galvanometer that operates and generates a rotational driving force in one direction or the other direction is used, thereby selectively driving a required aperture. But
The aperture drive source may be a motor or the like.

The galvanometer 1 is fixed to a portion near one side edge of the back surface of the relatively thick mounting substrate 2 with mounting screws, and its rotary output shaft 1a passes through the notch 2c of the substrate 2 and The front face of 2 protrudes crocodile. An output gear 3 composed of a sector gear is fixed to the output shaft 1a.

As shown in FIGS. 1 and 3, the mounting substrate 2 has an exposure opening 2a formed of a circular opening in the center of the other side edge, and a photographic optical hole is formed in the opening 2a. Front lens unit L of the system
(See FIG. 2).
Adjacent to the opening 2a, there is provided a circular concave portion 2b provided at the rear half of the driving member 4 of the aperture driving mechanism.
At the center of the bottom wall surface of 2b, a boss shaft 2d is planted so as to protrude along the optical axis direction. Further, in the bottom wall surface of the concave portion 2b, position arc-shaped holes 2e and 2f having a partial arc shape are formed at symmetrical positions around the boss axis 2d. Restriction pins 7a, 8a of aperture plate fixing members 7, 8, which will be described later, protrude into the position restriction slots 2e, 2f, respectively.

As shown in FIGS. 1 and 2, the aperture driving mechanism includes a cylindrical portion 4a that is tightly and rotatably fitted to the large-diameter shaft portion of the boss shaft 2d,
A semi-cylindrical portion 4b integrally provided around the cylindrical portion 4a, a driving gear 4c formed at the front of the outer peripheral surface of the semi-cylindrical portion 4b and meshing with the output gear 3, the semi-cylindrical portion 4b, A driving member 4 having a driving pin 4d provided integrally with the cylindrical portion 4a and protruding in the optical axis direction, and the cylindrical portion 4a.
, And a return spring 9 wound around the diaphragm, and the diaphragm plate fixing members 7 and 8.

The diaphragm plate fixing member 8 includes a disk having a semicircular portion formed on the outer periphery thereof, a diaphragm plate mounting boss integrally formed on the front surface of the disk, and the semicircular portion in the optical axis direction. Is formed having the above-mentioned regulating pin 8a integrally fixed to the same semicircular portion, and the center opening 8b is tightly fitted to the medium-diameter shaft portion of the boss shaft 2d. It is arranged rotatably. Then, one of the plurality of aperture plates is attached to and fixed to the aperture plate fixing member 8.

The diaphragm plate 5 and the other diaphragm plate 6 to be described later are formed of a very thin and thick polyester sheet, for example, about 0.1 mm, which is formed in an elongated rectangular shape and rounded at both ends. Mounting holes 5b, 6b are drilled,
Aperture openings 5a and 6a are provided at the center near the tip end, respectively. In the present embodiment, the one stop aperture 5a is set to “F
An aperture diameter of 5.6 "is formed, and the other aperture 6a is formed of an aperture diameter of" F11 ".

The one aperture plate 5 has its mounting aperture 5b on the aperture plate mounting boss of the aperture plate fixing member 8 and the positioning hole near the mounting aperture 5b on the front side of the regulating pin 8a. The protruding pins are respectively fitted, and are fixed to the front surface of the diaphragm plate fixing member 8 with an adhesive or the like. Therefore, the diaphragm plate 5 is integrated with the diaphragm plate fixing member 8 and rotates together. Also,
The other diaphragm plate 6 is fixed to the rear surface of the other diaphragm plate fixing member 7 disposed in front of the one diaphragm plate fixing member 8.

The other diaphragm plate fixing member 7 is also formed in substantially the same shape as the one diaphragm plate fixing member 8. That is, a disk having a semicircular portion formed on its outer periphery, a diaphragm plate mounting boss formed integrally with the rear surface of the disk, and an optical axis direction fixedly planted on the semicircular portion. The restriction pin 7a protruding rearward
The center through hole 7b is tightly fitted to the middle diameter shaft portion of the boss shaft 2d and is rotatably disposed (see FIG. 2).

The other aperture plate 6 is attached to the other aperture plate fixing member 7 formed in this way, and its mounting opening 6b is inserted into the aperture plate fixing member 7.
The rear surface of the diaphragm plate mounting boss portion and the positioning hole near the mounting opening 6b are fitted to the regulating pin 7a, respectively, and are fixed to the rear surface of the diaphragm plate fixing member 7 with an adhesive or the like.
Therefore, the diaphragm plate 6 is integrated with the diaphragm plate fixing member 7 and rotates together.

The restricting pins 7a, 8a extending rearward from the diaphragm plate fixing members 7, 8 to which the diaphragm plates 5, 6 are respectively fixed are wound around the ends of the return spring 9 respectively. As shown in FIG. 5, the leading end of the tip protrudes into the position regulating slots 2e and 2f. The return spring 9 is
As shown in FIGS. 1 and 6, it is a coil spring wound around the cylindrical portion 4a, one end 9a of which is wound around the regulating pin 8a, and the other end 9b is further counterclockwise from the natural state position 9Ab. It is turned in the direction (in FIG. 6) and wound around the regulating pin 7a. Accordingly, the spring 9 applies an urging force to rotate one of the restriction pins 8a in a counterclockwise direction and the other restriction pin 7a to rotate in a clockwise direction. However, the rotation of the restriction pins 7a and 8a by the urging force is applied. Movement is prevented by one of the inner ends of the position regulating slots 2e, 2f as shown in FIG. 3, and in this regulated position, the aperture plates 5, 6 are normally exposed as shown in FIG. The aperture openings 5a and 6a are stopped at positions off the center of the opening 2a.

In the state where neither of the diaphragm plates 5, 6 is operated, the drive pin 4d is connected to one of the notched ends of the semicircular portions of the diaphragm plate fixing members 7, 8 as shown in FIGS. 7c and 8c are maintained in a position sandwiched in a neutral position. In this position, as shown in FIG. 1, an open aperture opening 10a formed in the cover plate 10, for example, an aperture of "F2.8" Aperture aperture 10a with aperture diameter
Is on the optical axis O in front of the lens group L of the photographing optical system.

The cover plate 10 is a thin plate having a front shape substantially the same as the front shape of the mounting substrate 2. The open stop opening 10 a is formed at a position corresponding to the photographing lens optical axis O. At a position facing the shaft 2d, a through-hole 10b is formed in which the small-diameter shaft portion at the tip of the boss shaft 2d is fitted. Attachment portions 11a formed at three places on the outer peripheral edge of the front surface of the attachment substrate 2,
It is configured to be fixed to 11b, 11c with screws or the like (not shown).

In the aperture driving device of the present embodiment thus configured, one of the aperture plates 5, which is rotated clockwise when driven by the meter 1 as an actuator, normally has a counterclockwise rotation as shown in FIG. The regulating pin 8a is urged clockwise to a retracted position off the exposure optical axis of the exposure opening 2a by the contact of the regulating pin 8a with the inner end of the position regulating slot 2f, and also in the counterclockwise direction during driving. The other diaphragm plate 6 to be rotated is also urged in the clockwise direction, and is at the retracted position deviated from the exposure optical axis O when the regulating pin 7a comes into contact with one inner end of the position regulating elongated hole 2e. Therefore, in this normal state, the cover plate 10
A stop aperture 10a having a diameter of the stop aperture is formed on the exposure optical axis O as an open stop.

In this state, the measured exposure value is now "F5.6"
Is selected, the current corresponding to the value flows through the meter 1, the drive gear 4c is rotated via the output gear 3, and the drive pin 4d is rotated clockwise around the boss shaft 2d (eighth).
(See the figure). Then, the pin 4d pushes the notch end 8c of the aperture plate fixing member 8 clockwise, so that the aperture plate 5
Also, as shown in FIG. 8, the regulating pin 8a is pivotally displaced clockwise until the regulating pin 8a abuts on the other inner end of the position regulating slot 2f.
The aperture 5a arranges “F5.6” on the photographing optical axis O.
In a state where the aperture 5a is arranged on the optical axis, the other aperture plate 6 is not displaced in a flat state. Therefore,
No working space is required. In addition, the return spring 9 accumulates its return elasticity with the operation of the aperture plate 5. That is, the rotation of the diaphragm plate fixing member 8 in the clockwise direction causes the restriction pin 8a to rotate.
Both of them rotate until they come into contact with the other inner end of the position regulating slot 2f, so that one end of the return spring 9 also rotates with this.
The spring 9 accumulates rebound elasticity.

When photographing is performed in this state and the current to the meter 1 is cut off, the diaphragm plate 5 and the diaphragm plate fixing member 8 rotate counterclockwise due to the release elasticity of the stored elasticity of the spring 9 and rotate to the initial position. Return to

When the aperture is reduced to "F11", the driving pin 4d is rotated counterclockwise (see FIG. 9) around the boss shaft 2d by the meter 1 via the output gear 3 and the driving gear 4c. You. Then, the pin 4d pushes the notch end 7c of the diaphragm plate fixing member 7 in the counterclockwise direction, so that the diaphragm plate 6 rotates counterclockwise until the regulating pin 7a abuts on the other inner end of the position regulating slot 2e. Rotationally displaces in the direction. Then, as shown in FIG. 9, "F11" of the aperture 6a is arranged on the photographing optical path. Again,
The other diaphragm plate 5 is not displaced at all in a flat state. In addition, the rotation of the aperture plate fixing member 7 causes the restriction pin 7a to rotate together with the other inner end of the long hole 2e for position restriction, so that the other end of the return spring 9 also rotates with this. Thus, the spring 9 stores the rebound elastic force.

Then, when the photographing is completed and the current to the meter 1 is cut off, the diaphragm plate 6 and the diaphragm plate fixing member 7 rotate clockwise due to the opening elasticity of the spring 9 and return to the initial position.

In the above-described embodiment, three aperture stops are selected by two aperture plates. However, a large number of aperture openings can be obtained by arranging a plurality of sets of aperture plates in parallel and switching the drive system appropriately. Can be set. Further, in the above embodiment, the diaphragm plates 5 and 6 are rotated and displaced in different directions from each other. However, the two plates are stacked so as to be rotationally displaced in the same direction, and either one is selected. Of course, it may be arranged on the exposure optical axis.

[Effects of the Invention] According to the present invention configured as described above, since a plurality of diaphragm plates are driven by a single driving source, cost reduction and miniaturization are possible, and a conventional turret-type diaphragm device is provided. As described above, when obtaining a required aperture, the disadvantage that an unnecessary aperture also rotates and occupies a useless space can be solved brilliantly. Therefore, it is possible to provide an aperture driving device suitable for downsizing of a camera which does not require extra space at low cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an aperture driving device showing one embodiment of the present invention, FIG. 2 is an enlarged sectional view of a main part of the aperture driving device of FIG. 1, and FIG. FIGS. 4 and 5 are enlarged cross-sectional views of main parts showing the arrangement of drive pins and restriction pins in the aperture drive device of FIG. 1, respectively. FIG. 7 is an enlarged front view of the return spring, FIG. 7 is an enlarged front view showing a state in which the diaphragm plate is arranged in a flat state, and FIGS. 8 and 9 are enlarged front views each showing an operating state of the diaphragm opening. It is. 1 Driving source (galvanometer) 4 3rd driving force transmission mechanism (driving member) 5a 1st diaphragm opening 5 1st diaphragm plate 6a 2nd diaphragm opening 6 ... second 2 diaphragm plate 7 ... second driving force transmission mechanism (aperture plate fixing member) 8 ... first driving force transmission mechanism (aperture plate fixing member) 9 ... elastic member (return spring)

Claims (1)

(57) [Scope of request for utility model registration] A first diaphragm plate provided so as to be rotatable and displaceable and having a predetermined first diaphragm opening; a first diaphragm plate having a common rotation center with the first diaphragm plate; A second diaphragm plate which is provided so as to be capable of rotating and rotating independently of the diaphragm plate, and has a predetermined second diaphragm opening; and displacing the first diaphragm plate in a first rotational direction, A first driving force transmitting mechanism for transmitting a driving force in the first rotational displacement direction so as to stop at the operating position; and a second driving plate for moving the second diaphragm plate in a second direction opposite to the first rotating direction. Displaced in the direction of rotation of the
A second driving force transmitting mechanism for transmitting the driving force in the second rotational displacement direction; and a first or second driving force transmitting mechanism commonly provided for the first and second driving force transmitting mechanisms. A third driving force transmitting mechanism for transmitting the rotational driving force of the driving source to the driving force transmitting mechanism; and a third driving force transmitting mechanism coupled to the third driving force transmitting mechanism, the third driving force transmitting mechanism being operated by a current corresponding to the photometric exposure value, and Or a single driving source for generating a rotational driving force in the second rotation direction, and an elastic member for accumulating a rebound elasticity by the rotational driving force of the driving source. A diaphragm driving device, wherein the first diaphragm plate or the second diaphragm plate stopped at the second position is returned to an initial position by the opening elasticity of the resilience for reversal stored in the elastic member.