JP2516275Y2 - Aperture device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a diaphragm device, more specifically, a diaphragm device including a thin diaphragm plate used in an electronic still camera, a normal camera using a silver salt film, or the like. It is a thing.

[Prior Art] As is well known in the art, diaphragm devices used in cameras and the like include a so-called iris diaphragm type in which a plurality of diaphragm blades are rotated by an arrow wheel to form a diaphragm opening, and a single diaphragm diaphragm. Select multiple diaphragm apertures with different aperture diameters at equal intervals in a circular plate or a single strip of thin plate and move them in the turret type or slide type on the exposure optical path to select the aperture. There is a diaphragm plate moving type.

The above-mentioned iris diaphragm type has a complicated structure, has a large number of parts, and has a poor aperture diameter forming accuracy.
The above-mentioned diaphragm plate 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 preliminarily formed in one thin plate. It is preferred and used for cameras with small screen size such as electronic still cameras. For example, JP-A-63
In the -125921 publication, a plurality of diaphragm apertures having different aperture diameters are formed at equal angular positions on one sector disk, and are driven by a turret type. The iris device of the above-mentioned type is applied to an electronic still camera, and in Japanese Patent Laid-Open No. 63-218929, the iris apertures in the above-mentioned diaphragm plate moving type iris device are arranged in parallel with each other. There is disclosed a technical means for preventing the occurrence of ghost, flare, etc. on the photographing screen.

The applicant of the present invention has also previously used, as a diaphragm device of this type, a diaphragm plate provided with apertures having different diaphragm aperture diameters on both sides of the diaphragm aperture located on the photographing optical path. We have proposed a diaphragm device which can be rotated clockwise or counterclockwise to set a desired diaphragm aperture at the shortest distance {Japanese Patent Laid-Open No. 63330671 (JP-A-2-173730).
[Problems to be Solved by the Invention] However, in the turret type diaphragm device in which a plurality of diaphragm apertures having different aperture diameters are provided in the conventional single diaphragm plate,
When the diaphragm plate is rotationally displaced to arrange the desired diaphragm aperture on the optical axis, the diaphragm plates having other diaphragm apertures are also displaced by the same amount as the diaphragm aperture is displaced to the operating position on the optical axis. Therefore, there is a drawback in that a space for allowing this displacement must be additionally provided at the diaphragm arrangement position, which causes a problem that the camera becomes large.

Therefore, it is conceivable to use a plurality of thin diaphragm plates and selectively displace the diaphragm plates so that the diaphragm device can be positioned at an effective operating position. However, since the diaphragm plate is a thin plate, it may be deformed in the optical axis direction due to "orientation", causing interference during driving, flare occurrence, or defective light amount distribution on the image forming surface due to diaphragm performance.

The object of the present invention is to eliminate the above-mentioned conventional drawbacks.
Using a plurality of thin plate-shaped diaphragm plate, among the diaphragm apertures formed in the diaphragm plate, those not used at that time are prevented from being displaced due to the rotational displacement of the diaphragm aperture used,
An object of the present invention is to provide a diaphragm device capable of preventing deformation of the diaphragm plate without providing a dedicated member.

[Means and Actions for Solving the Problems] In the diaphragm device according to the present invention, a plurality of thin diaphragm plates having diaphragm apertures are provided so as to have a superposed arrangement in the optical axis direction of the optical system. A plate is a diaphragm device which is selectively rotatably displaced so that its diaphragm aperture can be positioned at an effective operating position concentric with the optical axis of the optical system. A diaphragm having a pivotally mounted boss member that is integral with the diaphragm plate or is a separate rigid body from the center of motion or in the vicinity thereof, and this boss member is pivotally mounted by another adjacent boss member. It is characterized in that a deformation preventing portion for preventing deformation of the plate is formed.

[Embodiment] Hereinafter, the present invention will be described with reference to an illustrated embodiment.

1 and 2 show a diaphragm 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 an essential part. In this embodiment, a galvanometer that operates according to the photometric value is used as the diaphragm driving source, and the necessary diaphragm aperture is selectively driven by this, but this diaphragm driving source may be a motor or the like.

The galvanometer 1 is fixed by a mounting screw to a portion near the one side edge of the rear surface of the mounting substrate 2 having a relatively thick thickness, and the rotation output shaft 1a thereof penetrates the notch 2c of the substrate 2 and is mounted on the substrate 2. The front surface of 2 is protruding to the alligator. 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 board 2 has an exposure opening 2a formed of a circular opening at the center of the other side edge, and the exposure optical opening 2a is formed in the opening 2a. System front lens group L
(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 and 8a of diaphragm plate fixing members 7 and 8, which will be described later, are projected into the position restriction slots 2e and 2f, respectively.

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

The diaphragm plate fixing member 8 penetrates the disk having a semicircular portion formed on the outer periphery thereof, the diaphragm plate mounting boss integrally formed on the front surface thereof, and the semicircular portion in the optical axis direction. Is formed to have the restriction pin 8a integrally fixed to the semicircular portion, and the central opening 8b is tightly fitted to the medium diameter shaft portion of the boss shaft 2d so as to be freely rotatable. It is arranged. 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 which will be described later are elongated rectangular shapes and rounded at both ends. It is very thin, for example, it is formed of a polyester sheet of about 0.1 mm, and the mounting holes 5b and 6b are formed at the base end,
Aperture openings 5a and 6a are provided at the center near the tip end, respectively. In this embodiment, the above-mentioned one stop aperture 5a is
The aperture diameter is "F5.6" and the other aperture opening 6a is "F1".
It is formed with an aperture diameter of 1 ".

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 restriction pin 7a, respectively, and 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.

Further, as shown in FIGS. 2 and 4, the fixing members 7 and 8 have their respective axial end surfaces close to their outer circumferences so as to come into contact with the diaphragm plates 5 or 6 which are opposed to each other in the assembled state. Protrusions 7d and 8d that are deformation preventing portions are provided.

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 of which is further counterclockwise from the natural state position 9Ab. It is rotated in the direction (in FIG. 6) and hung on the restriction pin 7a. Therefore, the spring 9 applies an urging force that rotates one regulating pin 8a in the counterclockwise direction and the other regulating pin 7a in the clockwise direction by the spring 9, but the regulating pins 7a and 8a are rotated by this urging force. As shown in FIG. 3, the movement is blocked by one of the inner ends of the position regulating long holes 2e, 2f. At this regulating position, both diaphragm plates 5 and 6 are normally used for exposure as shown in FIG. The diaphragm openings 5a and 6a are made to stand still at positions deviated from the center of the aperture 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 lid plate 10 is a thin plate whose front shape is substantially the same as the front shape of the mounting substrate 2, and the open diaphragm opening 10a is formed at a position corresponding to the optical axis O of the photographing lens, and the boss is formed. A through hole 10b into which a small-diameter shaft portion at the tip of the boss shaft 2d is fitted is formed at a position facing the shaft 2d, and a clearance hole 10c for the drive pin 4d is formed around the through hole 10b. Mounting portions 11a formed at three positions on the outer peripheral edge of the front surface of the mounting substrate 2,
It is adapted to be fixed to 11b and 11c with screws or the like (not shown).

In the diaphragm device of the present embodiment having such a configuration, one diaphragm plate 5 which is rotated clockwise by the meter 1 which is an actuator is usually a counterclockwise clock as shown in FIG. When the regulating pin 8a is urged in the direction to abut against one inner end of the position regulating elongated hole 2f
The other diaphragm plate 6 which is in a retracted position off the exposure optical axis of 2a and which is rotated counterclockwise during driving is also urged clockwise in the normal direction so that the restriction pin 7a moves to the position restriction slot 2e. It is in a retracted position off the exposure optical axis O by coming into contact with the inner end. Therefore, in this normal state, the diaphragm aperture 10a having the diaphragm aperture diameter provided in the cover plate 10 is arranged on the exposure optical axis O as an open diaphragm.

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. Further, as the diaphragm plate 5 is actuated, the return spring 9 stores its return elasticity. 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 counterclockwise, so that the diaphragm plate 6 counterclockwise until the regulating pin 7a abuts the other inner end of the position regulating elongated hole 2e. Is rotated and displaced 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.

The open diaphragm and diaphragm "F5.6" shown in Figs.
In addition, in each state of the diaphragm “F11” and its transition state, the projections 7d and 8d of the fixing members 7 and 8 always act to prevent the deformation of the diaphragm plates 5 and 6 due to “orientation”. The operation failure due to the deformation of 6 and the occurrence of the above-described optical aperture failure state are prevented in advance.

In the above embodiment, three diaphragm apertures are selected by two diaphragm plates. However, if a plurality of diaphragm plates are arranged in parallel and the drive system is switched appropriately, a large number of diaphragm apertures can be selected. Can be set. Further, in the above embodiment, the diaphragm plates 5 and 6 are rotatably displaced in mutually different directions, but this is also constructed so that two sheets are stacked and rotatably displaced in the same direction respectively, and either one is selected. As a matter of course, it may be arranged on the exposure optical axis.

Further, in this embodiment, the diaphragm plates 5 and 6 are fixed members thereof.
Although it is assumed that the diaphragm plate 5 or 6 is fixed to the members 8 and 7 by adhesion, it is also possible to manufacture the diaphragm plate 5 or 6 together with the fixing member 8 or 7 as an integrally molded product. Further, the above-mentioned projections 8d and 7d and the regulation pins 8a and 7a can be integrally formed at the same time, and the number of parts can be reduced.

[Advantages of the Invention] As described above, the diaphragm device of the present invention uses a plurality of thin diaphragm plates. According to the present invention, the necessary diaphragm aperture is required as in the conventional turret diaphragm device. When obtaining the above, the disadvantage that the unnecessary aperture opening is rotated to occupy the wasted space is solved, and further, it is not necessary to separately provide a tilt-deformation preventing member for the thin diaphragm plate. Therefore,
It is possible to provide a low-cost diaphragm device suitable for downsizing a camera that does not require an extra space.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a diaphragm device showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of an essential part of the diaphragm device of FIG. 1, and FIG. 3 is a diaphragm of FIG. FIG. 4 is an enlarged front view of a mounting substrate in the apparatus, and FIGS. 4 and 5 are enlarged cross-sectional views of main parts showing the arrangement states of the drive pin, the protrusion, and the regulation pin in the diaphragm device of FIG. 1, respectively. FIG. 7 is an enlarged front view of the return spring, FIG. 7 is an enlarged front view showing the normal arrangement state of the diaphragm plate, and FIGS. 8 and 9 are enlarged front views showing the operating state of the diaphragm aperture. is there. 5 ... 1st diaphragm plate (thin diaphragm plate) 6 ... 2nd diaphragm plate (thin diaphragm plate) 7 ... diaphragm plate fixing member (boss member) 8 ... diaphragm plate fixing member (boss) Member) 7d …… Protrusion (deformation prevention part) 8d …… Protrusion (deformation prevention part)

Claims (1)

(57) [Scope of utility model registration request] 1. A plurality of thin diaphragm plates having diaphragm apertures are provided so as to have a superposed arrangement in the optical axis direction of the optical system, and these diaphragm plates are selectively rotatably displaced to form the diaphragm. A diaphragm device in which an aperture can be positioned at an effective operating position concentric with the optical axis of the optical system, wherein each diaphragm plate is provided with the same diaphragm plate over its rotation center or its vicinity. It has a pivotally mounted boss member which is an integral or separate rigid body, and this boss member is formed with a deformation prevention portion for preventing deformation of the diaphragm plate pivotally attached by another adjacent boss member. A diaphragm device which is characterized by being formed.