JP2022162684A - Diaphragm device and endoscope - Google Patents

Abstract

To provide a diaphragm device which is of a simple structure, and the diameter of which can be reduced.SOLUTION: A diaphragm device 1 comprises: a frame 10 that includes an inner tube part 11 extending along the axial direction; a stretchable diaphragm member 20 in which an opening 22 is formed at the center; a first drive member 30 and a second drive member 40 formed from shape memory alloy that stretches upon heating; and a current supply unit 50 constituted so as to supply a current to the drive members 30, 40. An outer circumferential edge 24 of the diaphragm member 20 is attached to the inner tube 11 of the frame 10. The opening 22 of the first drive member 30 can be expanded by stretching the diaphragm member 20. The opening 22 of the second drive member 40 can be narrowed by stretching the diaphragm member 20.SELECTED DRAWING: Figure 1

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aperture device and an endoscope, and more particularly to an aperture device capable of adjusting the amount of light and fluid passing through.

A diaphragm has been used to adjust the amount of light and fluid in various fields. In general, a diaphragm adjusts the amount of light or fluid passing through an opening by varying the area of the opening. For example, in the case of a diaphragm that adjusts the amount of light, it is common to adjust the amount of light by moving a light blocking member so as to block the opening from the outside of the opening (see, for example, Patent Document 1). . However, such a conventional diaphragm requires a space outside the aperture for retracting members such as a light shielding member. For example, in applications requiring a small diameter such as an endoscope, further reduction in the diameter of such a stop is required.

JP 2018-200417 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide an aperture device and an endoscope that have a simple structure and can be made small in diameter.

According to one aspect of the present invention, there is provided an expansion device that has a simple structure and can be made small in diameter. This throttle device includes a frame including a cylindrical portion extending along the axial direction, an expandable throttle member having an opening formed in the center, at least one driving member made of a shape memory alloy that expands and contracts by heating, a current supply configured to supply current to the drive member. An outer peripheral edge of the diaphragm member is attached to the cylindrical portion of the frame. The at least one driving member can expand and contract the diaphragm member by expansion and contraction to change the size of the opening.

FIG. 1 is a cross-sectional view schematically showing a diaphragm device according to one embodiment of the present invention. FIG. 2 is a diagram schematically showing a cross section taken along the line AA of FIG. 1. As shown in FIG. 3 is a diagram schematically showing an electric circuit including a drive member of the diaphragm device shown in FIG. 1. FIG. 4A is a cross-sectional view schematically showing a state in which a current is supplied to the first driving member of the diaphragm device shown in FIG. 1. FIG. 4B is a cross-sectional view schematically showing a state in which a current is supplied to the second driving member of the diaphragm device shown in FIG. 1. FIG. FIG. 5 is a diagram schematically showing the overall configuration of an endoscope including the diaphragm device shown in FIG. 1. FIG. 6 is a schematic cross-sectional view showing an enlarged distal end portion of the guide tube of the endoscope shown in FIG. 5. FIG.

1 to 6, an embodiment of a diaphragm device according to the present invention will be described in detail below. In FIGS. 1 to 6, the same or corresponding constituent elements are given the same reference numerals, and overlapping explanations are omitted. In addition, in FIGS. 1 to 6, the scale and dimensions of each component may be exaggerated, and some components may be omitted. In the following description, unless otherwise specified, terms such as "first" and "second" are used only to distinguish components from each other and indicate a particular rank or order. not a thing

FIG. 1 is a cross-sectional view schematically showing a diaphragm device 1 according to one embodiment of the present invention, and FIG. 2 is a diagram schematically showing a cross-section taken along the line AA of FIG. The diaphragm device 1 in this embodiment adjusts the amount of light that passes through the lens 2 and propagates along the axial direction (+Z direction) and propagates to the lens 3 on the downstream side. In this embodiment, the diaphragm device 1 is arranged between the lens 2 and the lens 3. However, the diaphragm device 1 can be arranged anywhere in the optical system. can be done.

As shown in FIGS. 1 and 2, the expansion device 1 includes an inner cylindrical portion 11 (cylindrical portion) extending along the axial direction and an outer cylindrical portion 12 extending along the axial direction outside the inner cylindrical portion 11 in the radial direction. and an annular aperture member 20 . The aperture member 20 is made of a light-shielding and stretchable material such as fiber, rubber, or carbon fiber. An opening 22 is formed in the center of the diaphragm member 20 . The outer peripheral edge 24 of the diaphragm member 20 is attached to the inner peripheral surface 11A of the inner cylindrical portion 11, and the inner peripheral edge 26 is located on the -Z direction side of the outer peripheral edge 24. As shown in FIG. Therefore, the throttle member 20 in this embodiment has a truncated cone shape.

The diaphragm device 1 also includes a plurality of driving members 30 (driving members) radially extending from the vicinity of the aperture 22 of the diaphragm member 20, and a plurality of drive members 30 (driving members) attached to the vicinity of the aperture 22 of the diaphragm member 20 so as to extend along the circumferential direction. and a drive member 40 (second drive member). As these driving members 30 and 40, for example, thin wires made of a shape memory alloy made of an alloy of nickel and titanium can be used. This shape memory alloy has the property of shrinking when heated, and when these drive members 30 and 40 are energized, the drive members 30 and 40 are heated and contracted. In addition, in FIG. 2, the second driving member 40 is indicated by a dotted line for easy understanding.

Each first drive member 30 has an end portion 31 attached near the opening 22 of the diaphragm member 20 and an end portion 32 attached to the inner peripheral surface 12A of the outer cylinder portion 12, The vicinity of the opening 22 of the diaphragm member 20 and the outer cylindrical portion 12 are connected.

The second drive member 40 has ends 41 and 42 with a gap between the ends 41 and 42 . In this manner, the second drive member 40 partially surrounds the perimeter of the opening 22 .

FIG. 3 is a diagram schematically showing an electric circuit including these drive members 30 and 40. As shown in FIG. As shown in FIG. 3, the diaphragm device 1 includes a current supply 50 configured to supply current to the drive members 30,40. Each end 31 of the first drive member 30 is connected to each other by a wire 35 which is connected by a wire 36 to a current supply 50 . The respective ends 32 of the first drive members 30 are also connected to each other by wires 37 which are connected by wires 38 to the current supply 50 . As a result, the plurality of first drive members 30 are connected in parallel to the current supply section 50, and the current supply section 50 can simultaneously supply current to the plurality of first drive members 30. ing.

An end 41 of the second drive member 40 is connected to a current supply 50 by a wire 45 and an end 42 of the second drive member 40 is connected to the current supply 50 by a wire 46 . As a result, the current supply unit 50 can supply current to the second driving member 40 .

In the diaphragm device 1 having such a configuration, when a current is supplied from the current supply unit 50 to the first driving member 30, the first driving member 30 is heated and contracts. Since the first driving members 30 are radially arranged around the opening 22 of the diaphragm member 20, the contraction of the first driving members 30 causes the first driving members 30 to move as shown in FIG. 4A. The vicinity of the opening 22 of the diaphragm member 20 to which the end portion 31 of the diaphragm 30 is connected is pulled radially outward, and the diaphragm member 20 is deformed. As a result, the aperture 22 of the diaphragm member 20 is widened, so that the amount of light passing through the aperture 22 of the diaphragm member 20 can be increased.

On the other hand, when current is supplied to the second drive member 40 by the current supply unit 50, the second drive member 40 is heated and contracts. Since the second driving member 40 is arranged along the circumferential direction around the opening 22 of the diaphragm member 20, the contraction of the second driving member 40 causes the diaphragm member 20 to move downward as shown in FIG. 4B. The aperture member 20 is also deformed by shrinking in the circumferential direction in the vicinity of the opening 22 . As a result, the aperture 22 of the aperture member 20 is narrowed, so that the amount of light passing through the aperture 22 of the aperture member 20 can be reduced.

In this manner, by supplying current to the drive members 30 and 40 from the current supply unit 50, the drive members 30 and 40 are heated and contracted to change the size of the opening 22 of the diaphragm member 20. FIG. Therefore, the amount of light passing through the aperture 22 of the diaphragm member 20 can be adjusted by supplying current to the drive members 30 and 40 from the current supply section 50 . In this case, since the size of the opening 22 of the diaphragm member 20 can be changed by expanding or contracting the diaphragm member 20, there is no need for a light shielding member for changing the size of the opening 22 of the diaphragm member 20. It is no longer necessary to secure a space outside the opening 22 for retracting the light shielding member. Therefore, the diameter of the entire diaphragm device 1 can be reduced.

In this embodiment, as shown in FIGS. 4A and 4B, the driving members 30 and 40 extend and contract the diaphragm member 20 so that the diaphragm member 20 is tilted in the axial direction (Z direction). That is, the diaphragm member 20 expands and contracts so that the inner peripheral edge 26 of the diaphragm member 20 moves in the axial direction with respect to the outer peripheral edge 24 . When the diaphragm member 20 is expanded and contracted so that the diaphragm member 20 is tilted in the axial direction (Z direction), the size of the opening 22 of the diaphragm member 20 can be easily changed.

Further, in the illustrated embodiment, the diaphragm device 1 has been described as an optical diaphragm device that adjusts the amount of light passing through the aperture 22 of the diaphragm member 20. It can also be used as a fluid restriction device for adjusting the amount of fluid passing through. When the throttle device 1 is used as a fluid throttle device, the inner peripheral edge 26 of the throttle member 20 is located downstream of the outer peripheral edge 24 in order to prevent the throttle member 20 from acting as resistance to the fluid flow. preferably. That is, it is preferable that the fluid flows in the -X direction in FIG. Further, when the expansion device 1 is used as a fluid expansion device, it is preferable to arrange a sealing member around the outer circumference of the inner tubular portion 11 in order to prevent the fluid from leaking out from the inner tubular portion 11 .

The diaphragm device 1 in the above-described embodiment includes both the first drive member 30 that widens the aperture 22 of the diaphragm member 20 and the second drive member 40 that narrows the aperture 22 of the diaphragm member 20. Only one of the drive member 30 and the second drive member 40 may be included. In the illustrated embodiment, the plurality of first driving members 30 are arranged radially, but the arrangement of the first driving members 30 is not limited to this. Furthermore, the above-described embodiments are described on the premise that the shape memory alloys forming the first driving member 30 and the second driving member 40 have the property of contracting when energized. is present, the first drive member 30 is used to narrow the opening 22 of the diaphragm member 20 and the second drive member 40 is used to widen the opening 22 of the diaphragm member 20 By doing so, the same effect as described above can be obtained.

Further, in the above-described embodiment, the diaphragm member 20 has a truncated cone shape, but the diaphragm member 20 may have an annular plate shape.

Next, an example of an endoscope including the diaphragm device 1 described above will be described. FIG. 5 is a diagram schematically showing the overall configuration of the endoscope 100 including the diaphragm device 1. As shown in FIG. This endoscope 100 includes a bendable guide tube 110 that can be inserted near an observation target, a laser light source 120 that outputs laser light for illuminating the observation target, and a laser light output from the laser light source 120 that guides the light. An illumination optical fiber 130 that propagates to the tip 112 of the tube 110, an image fiber 140 that transmits the light reflected by the observation target from the laser light from the illumination optical fiber 130, and a CCD that captures the image light transmitted by the image fiber 140. It includes a camera 150 , an imaging lens 160 that directs image light from the image fiber 140 to the CCD camera 150 , and a video monitor 170 that outputs the image sent from the CCD camera 150 via signal line 152 .

Illumination optical fiber 130 is an optical fiber including a single core and a clad covering this core, and is connected to laser light source 120 via connector 132 . Also, the image fiber 140 is an optical fiber including multiple cores and clads covering these cores, and is connected to the imaging lens 160 via a connector 142 .

FIG. 6 is a schematic cross-sectional view showing an enlarged distal end portion of the guide tube 110 shown in FIG. As shown in FIG. 6, the illumination optical fiber 130 and the image fiber 140 described above are inserted through the guide tube 110 . Illumination optical fiber 130 extends to distal end 112 of guide tube 110 . An objective lens 146 is attached to the distal end 112 of the image fiber 140 via a sleeve 144. This objective lens 146 includes the diaphragm device 1 and lenses 2 and 3 described above. The objective lens 146 is fixed to the end of the guide tube 110 together with the illumination optical fiber 130 by resin (not shown).

According to such an endoscope 100, the diameter of the diaphragm device 1 in the objective lens 146 can be reduced, so the diameter of the guide tube 110 can be reduced as compared with conventional endoscopes.

As described above, according to the first aspect of the present invention, there is provided a diaphragm device that has a simple structure and can be made small in diameter. This throttle device includes a frame including a cylindrical portion extending along the axial direction, an expandable throttle member having an opening formed in the center, at least one driving member made of a shape memory alloy that expands and contracts by heating, a current supply configured to supply current to the drive member. An outer peripheral edge of the diaphragm member is attached to the cylindrical portion of the frame. The at least one driving member can expand and contract the diaphragm member by expansion and contraction to change the size of the opening.

According to such a configuration, by supplying a current to the drive member from the current supply section, the drive member can be heated and expanded and contracted to change the size of the opening of the diaphragm member. Therefore, by supplying current to the drive member from the current supply unit, the amount of light or fluid passing through the opening of the diaphragm member can be adjusted. In this case, since the size of the aperture of the aperture member can be changed by expanding or contracting the aperture member, a space for retracting a member (for example, a light shielding member) for changing the size of the aperture of the aperture member is provided in the aperture. No need to secure it outside. Therefore, the diameter of the entire diaphragm device can be reduced.

It is preferable that the at least one drive member expands and contracts the diaphragm member so that the diaphragm member is tilted in the axial direction. By expanding and contracting the diaphragm member so that the diaphragm member is tilted in the axial direction, the size of the opening of the diaphragm member can be easily changed.

The at least one drive member may include a plurality of first drive members each connecting a vicinity of the opening of the aperture member and the frame. When an electric current is supplied to these first drive members by the current supply section, the expansion and contraction of the first drive members exerts a radial force on the vicinity of the opening of the diaphragm member to which the first drive members are connected. The diaphragm member is deformed. This changes the size of the aperture of the diaphragm member (eg, widens the aperture), so that the amount of light or fluid passing through the aperture of the diaphragm member can be adjusted (eg, increased).

The at least one drive member may include a second drive member extending circumferentially adjacent the opening of the aperture member. When a current is supplied to the second drive member from the current supply unit, the expansion and contraction of the second drive member expands and contracts the vicinity of the opening of the diaphragm member in the circumferential direction, thereby deforming the diaphragm member. As a result, the size of the aperture of the diaphragm member changes (eg, the aperture narrows), so that the amount of light or fluid passing through the aperture of the diaphragm member can be adjusted (eg, decreased).

The aperture member may be configured to adjust the amount of light incident along the axial direction, or may be configured to adjust the amount of fluid flowing along the axial direction. .

According to a second aspect of the present invention, there is provided an endoscope that has a simple structure and can be made small in diameter. This endoscope includes an optical fiber, an optical system for coupling light from a subject to the optical fiber, and the diaphragm device described above. The diaphragm device is arranged on an optical path from the subject to the optical fiber.

Although the preferred embodiments of the present invention have been described so far, it goes without saying that the present invention is not limited to the above-described embodiments and may be embodied in various forms within the scope of its technical concept.

1 diaphragm device 2, 3 lens 10 frame 11 inner cylinder 12 outer cylinder 20 diaphragm member 22 opening 24 outer peripheral edge 26 inner peripheral edge 30 first drive member 35 to 38 electric wire 40 second drive member 45, 46 electric wire 50 electric current Supply unit 100 Endoscope

Claims (7)

a frame including a tubular portion extending along the axial direction;
an expandable aperture member having an opening formed in the center, the aperture member having an outer peripheral edge attached to the cylindrical portion of the frame;
at least one drive member formed of a shape memory alloy that expands and contracts upon heating, the drive member being capable of expanding and contracting the restrictor member to change the size of the opening;
a current supply configured to supply current to the drive member. 2. The diaphragm device according to claim 1, wherein said at least one drive member expands and contracts said diaphragm member so that said diaphragm member is inclined in said axial direction. 3. A diaphragm apparatus according to claim 1, wherein said at least one driving member includes a plurality of first driving members each connecting the vicinity of said opening of said diaphragm member and said frame. 4. A diaphragm apparatus according to any one of claims 1 to 3, wherein said at least one drive member includes a second drive member extending circumferentially in the vicinity of said opening of said diaphragm member. The diaphragm device according to any one of claims 1 to 4, wherein the diaphragm member is configured to adjust the amount of light incident along the axial direction. The expansion device according to any one of claims 1 to 5, wherein the expansion member is configured to adjust the amount of fluid flowing along the axial direction. an optical fiber;
an optical system that couples light from a subject to the optical fiber;
An endoscope comprising the diaphragm device according to any one of claims 1 to 5, which is arranged on an optical path from the subject to the optical fiber.

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