JP2021021801A - Aperture device - Google Patents

Abstract

To provide a lens device capable of performing both elliptical and circular apertures with a single lens.SOLUTION: An aperture device includes: a plurality of aperture blades to which a drive pin is fixed; a bearing member supporting a rotation center member of the aperture blades; and a cam member having a cam groove that is engaged with the drive pin of the aperture blades. The shape of an opening formed by the plurality of aperture blades is formed in a first shape by one locus of a cam groove end surface, and a second shape by the other locus of the cam groove end surface.SELECTED DRAWING: Figure 2

Description

The present invention relates to a diaphragm device used in a lens device for photography, and more particularly to a diaphragm device in which the aperture shape of the diaphragm device is switched, a lens device having the same, and an imaging device.

Conventionally, a plurality of diaphragm blades equipped with a rotation axis are arranged at equal angles on the same circumference, and the diaphragm opening formed by overlapping the inner edges of the diaphragm blades is changed by the rotation of the diaphragm blades around the rotation axis. There is a known squeezing device.

The aperture aperture shape affects the goodness of the bokeh around the main subject in the captured image, and generally a beautiful blurred image can be obtained. Therefore, a diaphragm aperture shape close to a circle is required. On the other hand, there are also photographers who want a unique elliptical bokeh image of an anamorphic lens.

Here, 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 as shown in Patent Document 1. Has been proposed.

Japanese Unexamined Patent Publication No. 04-269727

However, according to the above-mentioned Patent Document 1, the structure for switching the aperture shape constitutes a diaphragm opening having a plurality of aperture shapes as dedicated shapes, which 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 a diaphragm device capable of switching the aperture shape between a circular shape and an elliptical shape with one diaphragm device, and a lens device and a photographing device having the same diaphragm device.

In order to achieve the above object, the lens device according to the present invention is
A diaphragm including a plurality of diaphragm blades to which drive pins are fixed, a support member for supporting a rotation center member of the diaphragm blades, and a cam member having a cam groove engaged with the drive pins of the diaphragm blades. The apparatus is characterized in that the opening shape formed by the plurality of diaphragm blades is formed into a first shape by one locus of the cam groove end face and a second shape by the other locus of the cam groove end face.

According to the lens device 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. Further, since the diaphragm blades can be urged to the end face of the cam groove, it is possible to suppress the change in the amount of light due to the play of the cam groove and the drive pin.

It is an overall view of the photographing apparatus in Example 1 of this invention. It is sectional drawing of FIG. 1 in Example 1 of this invention. It is an exploded perspective view inside the diaphragm mechanism in Example 1 of this invention. It is a view from the drive pin side of the diaphragm blade in Example 1 of this invention. It is a front view of the inside of the diaphragm mechanism in Example 1 of this invention. It is a back view of FIG. 6 in Example 1 of this invention. It is the schematic in the case of having a substantially circular opening shape in Example 1 of the present invention. It is the schematic in the case of having a substantially elliptical opening shape in Example 1 of the present invention. It is a figure which shows the change of the opening shape of the substantially circular shape in Example 1 of this invention. It is a figure which shows the change of the opening shape of the substantially elliptical shape in Example 1 of this invention. It is an overall view of the photographing apparatus in Example 2 of this invention. It is sectional drawing of FIG. 11 in Example 2 of this invention.

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

Hereinafter, the diaphragm device according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 10.

FIG. 1 shows an overall view of the photographing apparatus in this embodiment.

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

The diaphragm device 1 is configured with a diaphragm operation ring 5 that can be manually operated and has a gear having an outer diameter connected to a motor or a rotation operation member.

The aperture mode operation ring 3 slides and rotates on the outer diameter of a fixed cylinder 2 that is connected to a lens group (not shown) in the front-rear direction, and is connected to the fixed cylinder 2 by a fixing screw 100. Directional movement is restricted. The aperture operation ring 5 slides and rotates on the outer diameter of the fixed cylinder 2, and is moved in the rotation axis direction by the aperture operation ring retainer 6 connected to the fixed cylinder 2 by the fixing screw 110 and the aperture mode operation ring retainer 4. It is regulated. An operation ring display unit 5a indicating brightness is displayed on the aperture operation ring 5. An operation mode display unit 3a indicating the aperture opening shape is displayed on the aperture mode operation ring 3.

The photographer may rotate the aperture operation ring 5 and align the numerical value of the aperture operation ring display unit 5a with the index line 4a engraved on the aperture mode operation ring retainer 4 by printing or engraving so as to obtain the desired brightness. .. In order to change the aperture shape, the aperture mode operation ring 3 may be rotated and the display position of the aperture mode operation ring display unit 3a may be aligned with the index line 4a so as to obtain a desired aperture shape.

FIG. 2 shows a cross-sectional view of the photographing apparatus in this embodiment, FIG. 3 shows an exploded perspective view of the inside of the diaphragm device in this embodiment, and FIG. 4 shows a view from the drive pin side of the diaphragm blade 8.

The diaphragm device 1 has a diaphragm blade support cylinder (blade support member) 7, a plurality of diaphragm blades 8, a cam plate 9, a holding metal fitting 10, a diaphragm mode switching ring 11, and a plurality of springs 12 fixed to the diaphragm 2. Have inside.

The cam plate 9 slides and rotates on the inner diameter of the diaphragm blade support cylinder 7 about the central axis o, and the movement in the central axis o direction is regulated by the presser foot fitting 10, and the pin 140 fixed to the diaphragm operation ring 5 is used. connect. The presser foot fitting 10 has a C-ring shape, and is inserted into the inner diameter of the diaphragm blade support cylinder 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 support cylinder 7.

The plurality of diaphragm blades 8 housed in the diaphragm blade support cylinder 7 are inserted into the drive pin 8c that engages with the cam groove 9a of the cam plate 9 and the pin hole 7a formed in the diaphragm blade support cylinder 7. The rotation center pin 8b is integrally formed. The inner diameter of the diaphragm blade 8 is formed to be larger than the maximum opening diameter of a substantially circular shape (shape imitating a circle; first shape), and the opening shape is formed to be a substantially elliptical shape (shape imitating an ellipse; second shape). In this case, the arcs of the inner diameters of the plurality of diaphragm blades 8 can be smoothly connected.

The spring 12 is connected so as to pull the urging pin 8a projecting on the diaphragm blade 8 toward the pin 11a projecting on the diaphragm mode switching ring 11.

The diaphragm mode switching ring 11 slides and rotates on the inner diameter of the fixed cylinder 2, and the movement in the rotation axis direction is restricted by the diaphragm blade support cylinder 7 connected to the fixed cylinder 2 by the fixing pin 120. The aperture mode switching ring 11 is connected to the aperture mode operation ring 3 by a pin 130, and the aperture mode switching ring 11 can be rotated by rotating the aperture mode operation ring 3. The pin holes 7a of the diaphragm blade support cylinder 7 are provided on the same circumference, and the phase spacing of the holes is evenly divided. Further, on the surface of the diaphragm blade support cylinder 7, a through hole 7b as a niger of the urging pin 8a of the diaphragm blade 8 is provided on the same circumference.

FIG. 5 shows a front view of the diaphragm mechanism, and FIG. 6 shows a rear view of the diaphragm mechanism.

The cam plate 9 has a plurality of cam grooves 9a, and is formed by overlapping the inner edges of the diaphragm blades by sliding the drive pins 8c of the diaphragm blades 2 along the inner end surface or the outer end face of the cam grooves. The size of the aperture opening to be made is changed. In this embodiment, a cam locus is shown in which a substantially circular opening shape can be formed by the outer end surface of the cam groove and a substantially elliptical opening shape can be formed by the inner end surface. However, the cam locus is not limited to this, and various opening shapes can be created by making one end surface of the cam groove a cam locus capable of forming a desired opening shape. Further, in this embodiment, the opening shape is formed by using 12 diaphragm blades 9, but the present invention is not limited to this, and the number of blades can be changed as appropriate.

Next, a mechanism for switching the aperture opening shape will be described.

FIG. 7 shows a schematic view of the drawing mechanism when the opening shape is substantially circular, and FIG. 8 shows a schematic view when the opening shape is substantially elliptical. In addition, in FIG. 7 and FIG. 8, only one diaphragm blade 8 is described for the purpose of explaining the opening shape.

When the opening shape is substantially circular, the spring 12 pulls the urging pin 8a of the diaphragm blade 8 in the direction of the arrow 50 as shown in FIG. The diaphragm blade 8 rotates about the rotation center pin 8b and the drive pin 8c is urged toward the outer end surface of the cam lift 9a by the acting force in the direction of the arrow 51, which is a component force in the direction of the arrow 50. On the other hand, when the opening shape is substantially elliptical, the spring 12 pulls the urging pin 8a of the diaphragm blade 8 in the direction of the arrow 60 as shown in FIG. The diaphragm blade 8 rotates about the rotation center pin 8b by the acting force in the arrow 61 direction, which is a component force in the arrow 60 direction, and the drive pin 8c is urged toward the inner end surface of the cam lift 9a.

By rotating the aperture mode operation ring 3, the aperture mode switching ring 11 connected by the pin 130 is rotated, and the force direction of the spring 12 elastically connecting the pin 11a and the urging pin 8a of the aperture blade 8. To change. As a result, since the aperture shape can be changed, it is possible to switch between the circular and elliptical aperture shapes according to the effect of the bokeh that the photographer wants to obtain at the time of shooting. Further, since the diaphragm blade 8 is urged to the end surface of the cam groove 9a, it is possible to suppress a change in the amount of light due to play between the cam groove 9a and the drive pin 8c.

The operation of changing the opening shape by the user with the above configuration will be described.

FIG. 9 shows the change in the opening when the substantially circular opening shape is formed, and FIG. 10 shows the change in the opening when the substantially elliptical opening shape is used.

Here, when the aperture mode operation ring 3 is located at the position shown in FIG. 1, the aperture shape of the aperture is the opening shape shown in FIG. At this time, the aperture operation ring display unit 3a has the character "DC" coincided with the index line 4a, indicating that a general circular blurred image can be obtained. From this state, by rotating the aperture mode operation ring 3, the aperture mode switching ring 11 connected by the pin 130 is rotated, and the spring that elastically connects the pin 11a and the urging pin 8a of the aperture blade 8. Twelve force directions are changed. As a result, the opening shape shown in FIG. 10 is obtained. At this time, the aperture operation ring display unit 3a has the character "AN" coincided with the index line 4a, indicating that an elliptical blurred image as if taken with an anamorphic lens can be obtained.

Next, the operation of changing the aperture aperture diameter by the user will be described.

The aperture operation ring 5 is operated, and the cam plate 9 connected to the aperture operation ring 5 by the pin 140 is rotated around the central axis o. The diaphragm blade 8 rotates around the rotation center pin 8b so that the drive pin 8c follows the trajectory of the cam groove 9a, and the opening shape formed by the inner diameters of the plurality of diaphragm blades 8 changes.

Next, the user rotates the aperture mode operation ring 3 and the aperture operation ring 5 to the positions shown in FIG. 1, for example. At this time, as shown in FIG. 9A, the aperture opening shape is a substantially circular shape composed of the inner diameters of the plurality of aperture blades 8 and is in an open state, and the aperture operation ring display unit 5a has an aperture of "4". Indicates a value. When further rotated in the "22" direction from this position, the diaphragm blade 8 moves toward the smaller diameter side along the locus of the outer end surface of the cam groove 9a as shown in FIGS. 9 (b) to 9 (d). The shape of the opening formed in 8 changes.

The diaphragm device of this embodiment will be described with reference to FIGS. 11 and 12.

FIG. 11 shows an overall view of the diaphragm device in this embodiment, and FIG. 12 shows a cross-sectional view of FIG. 11.

The aperture mode operation ring 21 slides and rotates on the outer diameter of a fixed cylinder 20 that is connected to a lens group (not shown) in the front-rear direction, and movement in the rotation axis direction is restricted by the aperture mode operation ring 5. The aperture operation ring 5 slides and rotates on the outer diameter of the fixed cylinder 20, and is restricted from moving in the rotation axis direction by the aperture operation ring retainer 6 connected to the fixed cylinder 20 by a fixing screw 110 and the aperture mode operation ring 21. Has been done. A sliding washer 22 is provided between the aperture mode operation ring 21 and the aperture operation ring 5 to prevent rotation. An operation mode display unit 20a indicating an aperture opening shape is displayed on the aperture mode operation ring 20.

The photographer may rotate the aperture mode operation ring 21 and align the display position of the aperture mode operation ring display unit 21a with the index line 20a engraved on the fixed cylinder 20 by printing or engraving so as to obtain a desired aperture shape. .. Further, the photographer can rotate the aperture operation ring 5 and adjust the numerical value of the aperture operation ring display unit 5a to the “DC” or “AN” position of the aperture mode operation ring display unit 21a so as to obtain the desired brightness. good. The other reference numerals and configurations are the same as those in the first embodiment, and the description thereof will be omitted.

According to the configuration of this embodiment, the diaphragm device can be downsized while having the function of changing the opening shape as compared with the first embodiment.

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

1 Aperture device, 2 Fixed cylinder, 3 Aperture mode operation ring,
4 Aperture mode operation ring presser, 5 Aperture operation ring,
6 Aperture operation ring retainer, 7 Aperture blade support cylinder,
8 Aperture blades, 9 Cam plate, 10 Presser fittings,
11 Aperture mode switching ring, 12 spring

Claims (4)

A diaphragm including a plurality of diaphragm blades to which drive pins are fixed, a support member for supporting a rotation center member of the diaphragm blades, and a cam member having a cam groove engaged with the drive pin of the diaphragm blades. The lens device is characterized in that the opening shape formed by the plurality of diaphragm blades is formed into the first shape by one locus of the cam groove end face and the second shape by the other locus of the cam groove end face. The lens device according to claim 1, further comprising an urging means for urging the diaphragm blades in a rotation direction around a rotation center member of the diaphragm blades. The lens device according to claim 2, wherein the urging direction of the diaphragm blades by the urging member is changed by operating a switching means for switching the aperture shape. The lens device according to any one of claims 1 to 3, wherein the innermost diameter of the diaphragm blade is larger than the radius of the aperture shape of the first shape.