JP2021021800A - Diaphragm device and lens device having the same - Google Patents

Abstract

To provide a diaphragm device that can switch an opening shape between a circle and an ellipse with one diaphragm device, and a lens device having the same.SOLUTION: A diaphragm device 1 comprises: a plurality of diaphragm blades 10 in which rotation center pins 102, 202, 302 are fixed; a support member 7 that supports the rotation center pins 102, 202, 302; and a drive ring member 20 that is fitted to the support member 7 and is rotatable on the optical axis center with a fitting part as the axis of rotation. The plurality of diaphragm blades 10 are formed of first blade groups 100, 200 having a first curvature R1 at an inner edge part, and a second blade group 300 having a second curvature R2 at an inner edge part, and can be switched between a first shape in which an opening shape is formed only by the first blade groups 100, 200 and a second shape in which the opening shape is formed by the first blade groups 100, 200 and the second blade group 300.SELECTED DRAWING: Figure 5(a)

Description

The present invention relates to an aperture device used in a lens device for photographing, and particularly to a mechanism for switching an aperture aperture shape by a rotation operation.

Conventionally, a plurality of diaphragm blades equipped with a rotating shaft are arranged at equal angles on the same circumference, and the diaphragm opening shape is formed by overlapping the inner edges of the diaphragm blades by swinging around the rotating shaft of the diaphragm blades. A diaphragm device that changes the speed is known.

In such a diaphragm device, the diaphragm blades are provided with a rotation center pin and a drive pin, and the position of the drive pin with respect to the rotation center pin supported at a fixed position is guided by a cam groove formed in a circular drive ring. The structure to be used is common.

The aperture aperture shape affects the good bokeh around the main subject in the captured image, and the closer the aperture aperture shape is to a circle, the more beautiful the blurred image can be obtained. On the other hand, there are also photographers who want the unique oval-shaped bokeh that is taken when using an anamorphic lens.

When the photographer uses one imaging device to switch between a circular aperture shape and an elliptical aperture shape according to a blurred image desired at the time of photographing, a structure for selecting a plurality of aperture aperture shapes is disclosed as shown in Patent Document 1. Has been done.

Japanese Unexamined Patent Publication No. 4-269727

In the conventional technique disclosed in Patent Document 1 described above, since the diaphragm openings having a plurality of opening shapes as dedicated shapes are formed, it hinders the miniaturization of the photographing apparatus. Further, during shooting of a moving image, if the opening shape is switched, light is not transmitted once at the switching portion, so that there is a problem that continuous switching cannot be performed.

Therefore, an object of the present invention is to provide an aperture device capable of switching the aperture aperture shape between a circular shape and an elliptical shape with a single lens, and a lens device having the same.

In order to achieve the above object, the diaphragm device according to the present invention is
A plurality of throttle blades to which the rotation center pin is fixed, a support member that supports the rotation center pin, and a drive ring member that is fitted to the support member and can rotate around the optical axis with the fitting portion as the rotation axis. In the drawing device provided with, the plurality of drawing blades are composed of a first blade group having a first curvature at an inner edge portion and a second blade group having a second curvature, and have an opening shape. It is characterized by switching between a first shape formed by only one blade group and a second shape formed by a first blade group and a second blade group.

According to the present invention, it is possible to provide an aperture device capable of switching between a circular and an elliptical aperture shape according to the effect of bokeh that the photographer wants to obtain at the time of shooting.

Overall view of the diaphragm device in this embodiment Partial sectional view of the drawing device in this embodiment Partial fraction decomposition perspective view of the diaphragm device in this embodiment Front view of the first diaphragm blade as seen from the subject side Front view of the second diaphragm blade and the third diaphragm blade as viewed from the subject side Front view of the diaphragm device when the diaphragm opening diameter is elliptical Perspective view of the main part of the diaphragm device when the diaphragm opening diameter is elliptical Overall view of the diaphragm device at the time of open circular diaphragm in this embodiment Front view of the aperture device when the aperture opening diameter is open circular aperture Perspective view of the main part of the aperture device when the aperture opening diameter is open circular aperture Overall view of the diaphragm device at the time of small diaphragm in this embodiment Front view of the aperture device when the aperture opening diameter is small Perspective view of the main part of the aperture device when the aperture opening diameter is small

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 shows an overall view of the diaphragm device in this embodiment.

The diaphragm device 1 is a diaphragm drive unit in which an aperture of a lens group such as a focus, a zoom, and a relay unit (not shown) is determined, and the aperture opening shape continuously changes.

The diaphragm device 1 is configured with a diaphragm operation ring 3 which can be manually operated and has a gear connected to a motor and a rotation operation member as an outer shape.

The aperture operation ring 3 slides and rotates the outer shape of the fixed cylinder 2 connected to the lens group (not shown) in the front-rear direction, and moves in the optical axis direction by the aperture operation ring retainer 5 connected to the fixed cylinder 2 by the fixing screw 31. Is regulated.

The aperture operation ring display unit 4 indicating the brightness is displayed on the aperture operation ring 3. The photographer may rotate the aperture operation ring 3 and align the numerical value of the aperture operation ring display unit 4 with the index line 6 engraved on the aperture operation ring retainer 5 by printing or engraving so as to obtain a desired brightness.

FIG. 2 shows a cross-sectional view of FIG.

A connecting shaft 32 is fixed to the throttle operation ring 3, and the tip of the connecting shaft 32 fits into a connecting hole 24 integrally provided in the drive ring 20.

The drive ring 20 holds the inner edge of the diaphragm blade accommodating portion 7 in a slidable state, and when the diaphragm operation ring 3 is rotated, a rotational force is transmitted to the drive ring 20 by the connecting shaft 32 to rotate.

The diaphragm blade accommodating portion 7 is fixed to the fixed cylinder 2 by the diaphragm unit fixing portion 31 in a state where rotation around the central axis 50 is restricted by a rotation stop pin (not shown) or the like. The outer shape of the diaphragm unit fixing portion 31 and the inner edge of the fixing cylinder 2 are fixed by screw connection.

FIG. 3 is an exploded perspective view showing the diaphragm blade accommodating portion 7 shown in FIG. 2 and its internal structure.

The drive ring 20 slides and rotates on the inner edge of the diaphragm blade accommodating portion 7, and the movement in the central axis 50 direction is regulated by the cam holding member 30.

The cam holding member 30 has a C-ring shape, and is inserted into the inner edge of the diaphragm blade accommodating portion 7 by deforming it so as to narrow the opening of the C-ring portion, and by releasing the deformation and returning to the original shape. , Fixed to the diaphragm blade storage unit 7.

The plurality of diaphragm blades 10 housed in the diaphragm blade storage portion 7 are composed of three types of diaphragm blades 100, 200, and 300.

FIG. 4A shows the first diaphragm blade 100, and FIG. 4B shows the second diaphragm blade 200 and the third diaphragm blade 300.

The first diaphragm blade 100 is inserted into a first drive pin 101 that engages with a first cam groove 20a formed in the drive ring 20 and a first pin hole 7a formed in the diaphragm blade accommodating portion 7. The first rotation center pin 102 is integrally formed.

The shape of the inner edge of the diaphragm of the first diaphragm blade 100 is the first curvature R1.

The second diaphragm blade 200 has a second drive pin 201 that engages with a second cam groove 20b opened in the drive ring 20 and a third cam groove 301 opened in the third diaphragm blade 300. A third drive pin 203 to engage is provided.

Further, in the second diaphragm blade 200, in addition to the drive pin, a second rotation center pin 202 inserted into the second pin hole 7b formed in the diaphragm blade accommodating portion 7 is integrally formed.

The inner edge shape of the second diaphragm blade 200 has the same first curvature R1 as the first diaphragm blade 100.

The third diaphragm blade 300 includes a third cam groove 301 and a third rotation center pin 302 inserted into the third pin hole 7c formed in the diaphragm blade accommodating portion 7.

The inner edge shape of the third diaphragm blade 300 has a second curvature R2.

When the aperture operation ring 3 is operated and the drive ring 20 is rotated, the plurality of aperture blades 10 are centered on the rotation center pins 102, 202, 302, and the drive pins 101, 201, 203 are along the cam grooves 20a, 20b, 301. The opening shape formed by the inner edges of the plurality of diaphragm blades 10 changes.

FIG. 5A is a front view of FIG.

When the diaphragm operation ring 3 is located at the position shown in FIG. 1, the aperture shape of the diaphragm is a substantially elliptical shape (elliptical shape) determined by the inner edge curvature R1 of the first diaphragm blade 100 and the inner edge curvature R2 of the third diaphragm blade 300. The imitated shape; the second shape).

At this time, the aperture operation ring display unit 4 has the character "AN" coincided with the index line 6, indicating that an elliptical blurred image as if taken with an anamorphic lens can be obtained. ..

5 (b) is a partial perspective view showing the drive ring 20, the first diaphragm blade 100, the second diaphragm blade 200, and the third diaphragm blade 300 one by one in FIG. 5 (a).

In conjunction with the counterclockwise (ccw) rotation of the drive ring 20, the second diaphragm blade 200 is driven in the direction of arrow A along the second cam groove 20b engaged with the second drive pin 201.

In conjunction with the drive of the second diaphragm blade 200, the third diaphragm blade 300 is driven in the direction of arrow B along the third cam groove 301 engaged with the third drive pin 203.

At this time, since the first diaphragm blade 100 is located in the margin portion of the first cam groove 20a engaged with the first drive pin 101, the blades are not driven.

Next, the photographer rotates the aperture operation ring 3 to the position shown in FIG. 6, for example. At this time, as shown in FIG. 7A showing the front view of FIG. 6, the aperture opening shape is a substantially circular shape (circular shape) determined only by the inner edge curvature R1 of the first diaphragm blade 100 and the second diaphragm blade 200. The imitated shape; the first shape).

7 (b) is a partial perspective view showing the drive ring 20, the first diaphragm blade 100, the second diaphragm blade 200, and the third diaphragm blade 300 one by one in FIG. 7 (a).

In conjunction with the clockwise (cw) rotation of the drive ring 20, the second diaphragm blade 200 is driven in the arrow C direction along the second cam groove 20b engaged with the second drive pin 201.

In conjunction with the drive of the second diaphragm blade 200, the third diaphragm blade 300 is driven in the arrow D direction along the third cam groove 301 engaged with the third drive pin 203.

At this time, since the first diaphragm blade 100 is located in the margin portion of the first cam groove 20a engaged with the first drive pin 101, the blades are not driven.

Next, the photographer rotates the aperture operation ring 3 to the position shown in FIG. 8, for example. At this time, as shown in FIG. 9A showing the front view of FIG. 8, the aperture opening shape changes to the smaller diameter side and is determined only by the inner edge curvature R1 of the first diaphragm blade 100 and the second diaphragm blade 200. It has a substantially circular shape.

9 (b) is a partial perspective view showing the drive ring 20, the first diaphragm blade 100, the second diaphragm blade 200, and the third diaphragm blade 300 one by one in FIG. 9 (a).

In conjunction with the clockwise (cw) rotation of the drive ring 20, the first diaphragm blade 100 is driven in the arrow E direction along the first cam groove 20a engaged with the first drive pin 101.

The second diaphragm blade 200 is driven in the direction of arrow F along the second cam groove 20b engaged with the second drive pin 201.

At this time, since the third diaphragm blade 300 is located in the margin portion of the third cam groove 301 engaged with the third drive pin 203, the blades are not driven. Therefore, since the third diaphragm blade is driven and does not open in the radial direction, the diaphragm blade accommodating portion 7 can be miniaturized.

With the above configuration, in the present invention, the aperture opening shape can be selected from an elliptical shape and a circular shape simply by operating the diaphragm operation ring 3, and the diaphragm device can be miniaturized.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and modifications can be made within the scope of the gist thereof.

1 Aperture device, 2 Fixed cylinder, 3 Aperture operation ring, 7 Aperture blade storage,
7a 1st pin hole, 7b 2nd pin hole, 7c 3rd pin hole,
20 drive ring, 20a first cam groove, 20b second cam groove,
100 1st diaphragm blade, 101 1st drive pin,
102 1st rotation center pin, 200 2nd drive pin,
201 2nd drive pin, 202 2nd rotation center pin,
203 3rd drive pin, 300 3rd diaphragm blade,
301 3rd cam groove, 302 3rd rotation center pin

Claims (2)

Multiple diaphragm blades with fixed rotation center pins and
A support member that supports the rotation center pin and
A drive ring member that fits into the support member and can rotate around the optical axis with the fitting portion as the rotation axis.
In the aperture device equipped with
The plurality of diaphragm blades are composed of a first blade group having a first curvature at the inner edge portion and a second blade group having a second curvature at the inner edge portion, and have an opening shape of the first blade group. A drawing device characterized in that it can be switched between a first shape formed only by a single blade, a first blade group, and a second shape formed by a second blade group. The first blade group includes a first diaphragm blade having a first drive pin that engages with a first cam groove included in the drive ring member, and a second drive that engages with a second cam groove included in the drive ring member. It is composed of a second diaphragm blade having a pin, and the second diaphragm blade group is composed of a third diaphragm blade having a third cam groove that engages with a third drive pin included in the second diaphragm blade. The diaphragm device according to claim 1, wherein the diaphragm device is characterized.