JP2011002581A - Diaphragm driving mechanism and endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope device capable of achieving miniaturization of a diaphragm driving mechanism, and a smaller diameter of an insertion part.SOLUTION: The diaphragm driving mechanism includes: a telescoping actuator 62; a driving member 61 connected to the actuator 62; a driven member 63 frictionally engaged with the driving member 61; an optical diaphragm part 70 acting along a plane perpendicular to a center axial line O2 of the driving member 61, so as to change a diameter of a light passing port through which light going along a predetermined optical axis O1 can pass; and a motive power converting mechanism 66 converting a reciprocating action of the driven member 63 going along the driving member 61 into an action of the optical diaphragm part 70 in a plane perpendicular to the center axial line O1.

Description

  The present invention relates to a diaphragm drive mechanism and an endoscope apparatus.

  2. Description of the Related Art Conventionally, when inspecting the inside of a machine or the like, a method of inspecting endoscopically by inserting an endoscope apparatus into the inside of a machine or the like is known. For example, an endoscope apparatus is provided with a long insertion portion having a distal end and a proximal end, and an optical means for imaging an object at the distal end of the insertion portion. It has been.

  Here, Patent Document 1 describes an endoscope apparatus in which a plurality of optical members each including a lens and an aperture stop are provided as optical means on a fan-shaped base. In the endoscope apparatus described in Patent Document 1, the optical member selected by rotating the base can be arranged on the optical path. According to this endoscope apparatus, the focus and brightness can be switched according to the distance between the object and the object to be observed.

JP-A-4-208915

  However, in the endoscope apparatus described in Patent Document 1, since a plurality of sets of lenses and brightness diaphragms are provided on a fan-shaped base, a space in which the base is swung is required. For this reason, it was difficult to reduce the diameter of the insertion portion.

Accordingly, the present invention has been made in view of the above-described circumstances, and an object thereof is to reduce the size of the aperture driving mechanism.
Another object of the present invention is to provide an endoscope apparatus capable of reducing the diameter of the insertion portion.

  The diaphragm drive mechanism according to this embodiment includes an actuator capable of extending and contracting, a drive member connected to the actuator, a driven member frictionally engaged with the drive member, and a central axis of the drive member An optical diaphragm portion that operates along a surface, and a power conversion mechanism that converts an advance / retreat operation of the driven member along the drive member into an operation of the optical diaphragm portion in the plane orthogonal to the central axis. It is to be prepared.

  According to this embodiment, the drive member vibrates as the actuator is expanded and contracted. When the driving member vibrates, the driven member slides on the driving member due to the movement of the driving member in the direction of the central axis. The sliding movement of the driven member is converted into the operation of the optical diaphragm by the power conversion mechanism, and the diameter of the light passage opening changes in the optical diaphragm. As described above, since the diameter of the light passage opening can be changed by the expansion and contraction operation of the actuator, the element for driving the optical aperture section can be reduced in size.

In addition, the optical diaphragm section includes a support body arranged along the surface, and a light shielding member that changes the size of the light passage opening by a relative rotation operation around the optical axis with the support body. The power conversion mechanism preferably includes a cam portion that converts the forward / backward movement of the driven member into a rotational motion along the surface and transmits the rotational motion to the optical aperture portion.
In this case, since the advance / retreat operation of the driven member is converted into the rotation operation of the optical diaphragm unit in the cam unit, the optical diaphragm unit can be rotated.

Further, the optical aperture section has a light blocking member that changes the size of the light passage opening by a facing operation in a straight line direction orthogonal to the optical axis in the plane, and the power conversion mechanism You may have the cam part which converts the said advance / retreat movement into the said opposition operation | movement, and transmits to the said optical aperture part.
In this case, since the advancing / retracting operation of the driven member is converted into the facing operation of the optical diaphragm portion in the cam portion, the optical diaphragm portion can be opposed to the linear movement direction different from the advancing / retreating direction of the driven member.

Moreover, it is preferable that the said actuator expands-contracts in the center axis direction of the said drive member.
In this case, since the expansion / contraction operation is limited to one direction, it is possible to provide a more compact aperture driving mechanism. In this case, a plurality of lenses are arranged in the vicinity of the actuator and are elongated in the optical axis direction. If the drive member and the actuator are arranged so as to be adjacent to each other, a unified shape is obtained, which is effective for miniaturization.

The actuator preferably includes a piezoelectric element having a longitudinal direction and a short direction as viewed from the side, and uses the longitudinal direction of the piezoelectric element.
In this case, compared with an actuator using a shape memory alloy, a servo motor, or a hydraulic cylinder, voltage control is easier, so a highly accurate drive mechanism can be provided. In this case, as the piezoelectric element is reduced in size, the driving force becomes insufficient. In this case, if the number of stacked layers is increased in the above arrangement, expansion / contraction displacement can be obtained. In order to reduce the size of an endoscope as well, the radial direction can be kept small, which is effective.

In addition, it is preferable that the diaphragm drive mechanism of the present invention further includes a drive unit that causes the actuator to extend and contract, and the drive unit gradually changes the extension and contraction operation speed of the actuator.
In this case, the driven member frictionally engaged moves in a predetermined direction due to the difference in speed between expansion and contraction. When continuously operated, the driven member can be continuously moved even with a minute displacement of the piezoelectric element. If the opposite speed difference is given by expansion and contraction, the direction can be reversed.

  An endoscope apparatus according to this embodiment includes a sheath having a distal end and a proximal end and extending in an axial direction, an imaging mechanism that is disposed at the distal end of the sheath and captures an image of an object, and the sheath And an operation unit for operating the imaging device, wherein the imaging mechanism includes a diaphragm driving mechanism according to the present invention, and a solid-state imaging device arranged coaxially with the optical axis. A second drive member disposed parallel to the axis of the drive member, a second actuator capable of extending and contracting, and a friction engagement between the second drive member and the diaphragm drive mechanism and the solid-state image sensor. And a moving optical system that is arranged coaxially with the optical axis and changes the focal point of light traveling from the light passage port to the solid-state imaging device.

  According to the endoscope apparatus of the present embodiment, since the diaphragm drive mechanism can be configured in a small size, the imaging mechanism disposed at the distal end of the sheath can be downsized.

According to the diaphragm drive mechanism of this embodiment, the diameter of the light passage opening can be changed by vibrating the drive member by the actuator that expands and contracts, so that the diaphragm drive mechanism can be reduced in size.
According to the endoscope apparatus of the present embodiment, since the imaging mechanism can be miniaturized by providing a miniaturized aperture driving mechanism, the diameter of the insertion portion inserted into the object can be reduced.

It is a perspective view showing an endoscope apparatus of one embodiment of the present invention. It is a perspective view which decomposes | disassembles and shows a part of structure of the endoscope apparatus. FIG. 2A is a front view showing a partial configuration of the endoscope apparatus. FIG. 2B is an enlarged perspective view showing a part of the configuration of the endoscope apparatus. It is a perspective view which expands and shows a part of structure of the endoscope apparatus. (A) is a perspective view showing an enlarged configuration of a part of the endoscope apparatus, (B) is a perspective view showing a comparative example for explaining the configuration of the endoscope apparatus. (A) is sectional drawing which shows the operation | movement at the time of use of the same endoscope apparatus, (B) is a rear view which shows the operation at the time of use of the same endoscope apparatus. (A) And (B) is a rear view which shows operation | movement at the time of use of the same endoscope apparatus. It is a perspective view which decomposes | disassembles and shows the structure of a part of endoscope apparatus of 2nd Embodiment of this invention. It is a perspective view which decomposes | disassembles and shows a part of structure of the endoscope apparatus. (A) And (B) is a side view which shows the effect | action of the same endoscope apparatus. (A) And (B) is a front view which shows the operation | movement at the time of use of the same endoscope apparatus.

(First embodiment)
FIG. 1 is a perspective view showing an endoscope apparatus equipped with the drive mechanism of the present embodiment. As shown in FIG. 1, an endoscope apparatus 1 includes a sheath 2 that extends from a proximal end toward a distal end, an imaging mechanism 3 that is disposed at the distal end of the sheath 2 and photographs an object, and a sheath 2. A bending drive unit 3a that is disposed on the proximal end side of the imaging mechanism 3 to bend the sheath 2, and an operation unit 4 that is disposed on the proximal end of the sheath 2 to bend the bending drive unit 3a. And a main body 5 extending from the operation section 4 to the proximal end side and connected thereto.

  Although not shown in detail, the sheath 2 is formed in a flexible cylindrical shape, and a wiring path extending from the operation unit 4 and the main body 5 to the imaging mechanism 3 and the bending drive unit 3a is inserted therein.

  The operation unit 4 is provided with a joystick 4a for a user to input a bending direction in order to bend the bending driving unit 3a. In the endoscope apparatus 1 of the present embodiment, the direction in which the joystick 4a is tilted with respect to a predetermined neutral position is input to the main body 5 as the direction in which the bending drive unit 3a is bent. In the main body 5, the bending drive unit 3a is bent based on the input from the joystick 4a.

  The main body 5 includes a display 5a for displaying an image acquired by the imaging mechanism 3, and a control unit 50 for controlling the imaging mechanism 3 and the bending driving unit 3a.

  FIG. 2 is a perspective view showing a part of the configuration of the endoscope apparatus 1, and shows the configuration of the imaging mechanism 3 in an exploded manner. FIG. 3A is an enlarged front view showing a part of the configuration of the endoscope apparatus 1. FIG. 3B is an enlarged perspective view showing a part of the configuration of the endoscope apparatus 1. As shown in FIGS. 2 to 3B, the imaging mechanism 3 includes a case 31 fixed to the distal end of the sheath 2 shown in FIG. And a fixed cap 32.

  The imaging mechanism 3 is set with a predetermined optical axis O1. Along with the optical axis O1, a cover glass 32a provided on the cap 32, a diaphragm driving mechanism 60 that drives to change the diameter of a light passage port through which light along the optical axis O1 can pass, and a diaphragm driving mechanism 60, a moving optical system 80 that can be moved back and forth along the optical axis O1, and an imaging optical unit 90 that is arranged with a positional relationship fixed with respect to the cover glass 32a are arranged in this order. In the present embodiment, the cover glass 32a is a glass plate formed in a disk shape.

  The moving optical system 80 is for adjusting the focal length when the light incident from the cover glass 32a is guided to the imaging optical unit 90 and focusing on the object to be imaged. In the present embodiment, a convex lens is disposed in the moving optical system 80.

  The imaging optical unit 90 includes an imaging lens group 91 (not shown in detail) and a solid-state imaging element 92 that receives light emitted through the imaging lens group 91. An optical image incident from the cover glass 32 a via the moving optical system 80 is formed at a predetermined image formation position in the solid-state image sensor 92. Further, the imaging optical unit 90 is disposed with a positional relationship fixed with respect to the case 31.

  Although not shown in detail, a well-known CCD or CMOS area image sensor can be appropriately employed as the solid-state imaging device 92. Moreover, the solid-state image sensor 92 is electrically connected to the main body 5 shown in FIG. 1, and an image captured by the solid-state image sensor 92 is displayed on the display 5a.

  The aperture drive mechanism 60 is capable of passing light along the optical axis O1, an actuator 62 that can be expanded and contracted, a drive member 61 that is connected to the actuator 62, a driven member 63 that is frictionally engaged with the drive member 61, and the optical axis O1. A power conversion mechanism 66 that converts the advance / retreat operation of the optical diaphragm 70 that changes the diameter of the light passage opening and the driven member 63 along the drive member 61 into the operation of the optical diaphragm 70 in a plane orthogonal to the central axis O2. And.

  The drive member 61 is formed in a cylindrical shape having a generatrix along the central axis O2. The central axis O2 and the optical axis O1 are parallel. The drive member 61 is inserted through a hole 311 formed in the case 31, and is supported with the distal end 61a of the drive member 61 directed toward the distal end and the proximal end 61b of the drive member 61 directed toward the proximal end. Yes. A driven member 63 is frictionally engaged with the outer peripheral surface of the driving member 61.

  The actuator 62 has a first end 62a and a second end 62b, and is fixed to the drive member 61 at the first end 62a. The actuator 62 uses a piezoelectric element such as a piezoelectric element, and is a piezoelectric actuator that expands and contracts in the thickness direction when a voltage is applied by a lead wire (not shown). Further, the above-described piezoelectric element has a longitudinal direction and a lateral direction when viewed from the side, and operates using the longitudinal direction of the piezoelectric element. Since the actuator 62 is easier to control the voltage than an actuator using a shape memory alloy, a servo motor, or a hydraulic cylinder, a highly accurate drive mechanism can be provided.

  Although not shown in detail, a weight is fixed to the second end 62b of the actuator 62, and the weight is bonded and fixed to the case 31 via a metal member (not shown). In addition, it is preferable that the adhesion between the weight and the case 31 is configured to be bonded with flexibility such that, for example, a rubber-like adhesive is used. Since the weight and the case 31 are fixed using a flexible adhesive, vibration transmitted from the outside to the actuator 62 can be buffered. The actuator can generate a motion by obtaining an inertial force by a weight.

  In the actuator 62, the tip of the weight is a fixed end, and the positional relationship between the second end 62b and the case 31 is fixed. Therefore, when the actuator 62 expands and contracts, the first end 62a of the actuator 62 vibrates in the direction of the central axis O2 with the second end 62b as a fixed end. Although not shown in detail, the actuator 62 is electrically connected to the main body 5 through the inside of the sheath 2 shown in FIG.

  As shown in FIG. 3A, the driven member 63 includes a friction engagement portion 64 that frictionally engages with the driving member 61, one end fixed to the driven member 63, and the other end the outer periphery of the driving member 61. It has the elastic member 67 extended toward a surface. The other end of the elastic member 67 is provided with an attachment 67a that is frictionally engaged with the drive member 61 and fitted into the friction engagement portion 64. The driven member 63 and the driving member 61 are relatively movable along the central axis O2.

  In order to move the driven member 63 to the base end 61 b side of the driving member 61, a first driving pulse for vibrating the actuator 62 is applied in the control unit 50 shown in FIG. 1.

  The waveform of the first drive pulse is set so that the speed of extending the actuator 62 is relatively high and the speed of contracting the actuator 62 is relatively slow. For this reason, when the actuator 62 is extended, the driving member 61 and the driven member 63 against the frictional force generated between the frictional engagement portion 64 and the attachment 67 d of the driven member 63 and the driving member 61. Is slid and moved. At this time, the driving member 61 is linearly moved to the distal end side along the central axis O2, but the position of the driven member 63 is positioned substantially the same as the position before the driving member 61 is linearly moved. Yes.

Subsequently, the actuator 62 is contracted. At this time, since the contraction speed of the actuator 62 is relatively slow, the driving member 61 and the driven member 63 are integrated with each other by the frictional force generated between the frictional engagement portion 64, the attachment 67 d and the driving member 61. Moved.
Therefore, when the first drive pulse described above is applied to the actuator 62, the driven member 63 moves toward the base end 61b side by a certain width along the central axis O2 with the expansion and contraction of the actuator 62 as one unit. Is done.
Thus, the driven member 63 can be moved to the base end 61 b side of the driving member 61 by continuously applying the first driving pulse to the actuator 62.

  On the contrary, in order to move the driven member 63 to the tip 61 a side of the driving member 61, the control unit 50 applies a second driving pulse having a waveform different from that of the first driving pulse to the actuator 62.

The waveform of the second drive pulse is set so that the speed of extending the actuator 62 is relatively slow and the speed of contracting the actuator 62 is relatively fast. For this reason, contrary to the driving by the first driving pulse described above, when the actuator 62 is extended, the driving member 61 and the driven member 63 are linearly moved integrally. Further, when the actuator 62 is contracted, the driven member 63 is located at substantially the same place as before the actuator 62 contracts.
Moving the driven member 63 to the base end 61a side of the driving member 61 can be achieved by continuously applying the second driving pulse.

  In this way, the driven member 63 is moved back and forth along the central axis O2 of the driving member 61 by the diaphragm driving mechanism 60.

  As shown in FIG. 3B, the driven member 63 is formed with a substantially cylindrical main body 65 having both ends opened in the direction of the optical axis O1. The main body 65 has a long hole 65c formed through the wall 65b. The long hole 65c is formed with an angle with respect to the optical axis O1.

  In the present embodiment, a driving mechanism similar to the diaphragm driving mechanism 60 is provided for the moving optical system 80. As shown in FIGS. 2 and 3, the moving optical system 80 includes a second actuator 82 that expands and contracts in the direction of the central axis O <b> 3, and a second drive member 81 connected to the second actuator 82. The moving optical system 80 is driven back and forth by the expansion and contraction operation of the second actuator 82 based on the drive signal from the unit 50.

  As shown in FIG. 4, the optical aperture section 70 includes a support body 71 disposed along a plane orthogonal to the optical axis O1, a rotation section 72 that can be relatively rotated around the support body 71 and the optical axis O1, Light shielding members 73a to 73h that are connected to the support 71 and the rotating portion 72 and change the size of the light passage opening are included.

The support 71 is fixed to the cap 32 (see FIG. 2), and protrusions 71a to 71h extending toward the proximal end in the direction of the optical axis O1 are formed at equal intervals around the optical axis O1.
The rotating portion 72 is a ring-shaped member configured to be slidably fitted around the optical axis O1 with respect to the support 71. Furthermore, the rotation part 72 is formed with protrusions 72a to 72h extending in the optical axis O1 direction toward the proximal end side at equal intervals around the optical axis O1. Further, the protrusions 72a to 72h are disposed outside the protrusions 71a to 71h.
The light shielding members 73a to 73h are configured as a set of four, and the light shielding members 73a, 73c, 73e, and 73g and the light shielding members 73b, 73d, 73f, and 73h are engaged with the support member 71 to be shielded from the light shielding member 73a. A partition member 74 that supports ˜73h is interposed. Further, an annular cover 77 that functions as a retaining member for the light shielding members 73a to 73h is provided on the protrusions 71a to 71h.

The rotating portion 72 includes a connecting portion 75 that protrudes so as to engage with the main body 65 of the driven member 63, and a long hole that is provided in the connecting portion 75 and formed in the main body 65 of the driven member 63 described above. A protrusion 76 that fits into 65c is formed. The protrusion 76 and the long hole 65c are configured to be slidable.
The protrusion 76 and the above-described long hole 65 c constitute a cam portion (power conversion mechanism 66) that converts the advance / retreat operation of the driven member 63 into the rotation operation of the rotation portion 72.

  FIG. 5A is an enlarged perspective view showing a part of the configuration of the endoscope apparatus 1, and is a perspective view specifically showing the main body portion 65 of the driven member 63. FIG. 5B is a perspective view showing a comparative example of the configuration shown in FIG.

  As shown in FIG. 5A, in the present embodiment, the long hole 65c is formed to extend in a linear direction inclined with respect to the optical axis O1. For example, as shown in FIG. 5A, the axes L1 and L2 in the penetration direction of the wall portion 65b by the long holes 65c at both ends of the long hole 65c are parallel to each other.

  If the long hole 65c is configured in this way, the outer surface of the long hole 65c portion does not have a twisted shape, so that it becomes easy to manufacture a punching die when the driven member 63 is produced.

  The shape of the long hole 65c is such that it can be easily formed by approximating the shape of the long hole 65x formed in a spiral shape with the optical axis O1 as the center as shown in FIG. 5B. In the present embodiment, no problem occurs in the operation of the endoscope apparatus 1 even if the shape is along a spiral such as the long hole 65x.

The operation of the endoscope apparatus of the present embodiment having the above-described configuration will be described with reference to FIGS. 6 (A) to 7 (B).
FIG. 6A is a diagram for explaining the operation of the power conversion mechanism 66 (the driven member 63 and the rotating unit 72) in the endoscope apparatus 1. FIG. FIG. 6B is a diagram illustrating the operation of the rotating unit 72.

  As described above, the driven member 63 is moved back and forth along the outer peripheral surface of the driving member 61. For example, when the driven member 63 is moved back and forth so that the main body 65 of the driven member 63 moves from the surface Q to the surface R shown in FIG. 6A, the protrusion 76 engaged with the long hole 65c becomes the long hole 65c. It is pressed and moved along the wall surface.

  As shown in FIG. 6B, the direction in which the protrusion 76 is pressed moves the outer peripheral portion in the rotating portion 72 in the circumferential direction. Since the rotating part 72 is fitted to the support 71 so as to be slidable around the optical axis O1, and the support 71 is fixed to the cap 32 (see FIG. 2), the rotating part 72 and the support 71 And relative rotation about the optical axis O1.

Projection 76 receives a force indicated by _{F 1} in FIG. 6 (A) while sliding from the inner surface of the long hole 65c in the optical axis O1 direction. The force F ₁ is a force that acts to push the rotating portion 72 obliquely from the position of the protrusion 76 toward the support 71. The rotating part 72 is fitted into the support 71 in a cylindrical shape, and turns without floating from the support 71 by reducing the frictional resistance of the contact surface between the support 71 and the rotating part 72.
Thus, the advance / retreat operation of the driven member 63 is converted into the rotation operation of the rotation unit 72 relative to the support 71.

  FIGS. 7A and 7B are rear views showing an operation when the endoscope apparatus 1 is used. As shown in FIG. 7A, in a state where the optical diaphragm unit 70 is assembled, the protrusions 71a to 71h formed on the support 71 are inserted into the holes 731a to 731h formed on the light shielding members 73a to 73h, respectively. Has been. Each of the holes 731a to 731h is the center of turning when the light shielding members 73a to 73h are turned. Further, the protrusions 72a to 72h formed on the rotating portion 72 are inserted into the long holes 731b to 731b formed in the light shielding members 73a to 73h, respectively.

A light passage opening along the optical axis O1 is generated by the light shielding members 73a to 73h. When the rotating portion 72 is relatively rotated around the optical axis O1 with respect to the support 71, each of the light shielding members 73a to 73h rotates so as to approach or separate from the optical axis O1. Then, the diameter of the light passage opening changes between the maximum opening diameter d1 and the minimum opening diameter d2 of the light passage opening. In other words, the rotating unit 72 and the light shielding members 73a to 73h that operate in the optical diaphragm unit 70 all operate along a plane orthogonal to the optical axis O1, that is, a plane orthogonal to the central axis O2 of the drive member 61 to transmit light. The diameter of the mouth is changed.
In this embodiment, the diameter of the light passage opening is the minimum opening diameter d2 when the protrusion 72b is in contact with the point P1 shown in FIG. 6A, and the protrusion is at the point P2 shown in FIG. The maximum opening diameter d1 is reached when 72b is in contact.

  As described above, according to the endoscope apparatus 1 of the present embodiment, the advance / retreat operation of the driven member 63 due to the expansion / contraction operation of the actuator 62 is converted into the rotation operation around the optical axis O1 by the power conversion mechanism 66. . The light shielding members 73a to 73h are operated by the rotation operation around the optical axis O1 by the power conversion mechanism 66, and the diameter of the light passage opening can be changed. For this reason, the element which drives the optical aperture unit 70 can be reduced in size, and the aperture drive mechanism 60 can be reduced in size.

  In addition, an iris diaphragm in which the size of the light passage opening continuously changes in the range from the maximum opening diameter d1 to the minimum opening diameter d2 by the rotation operation is adopted for the optical diaphragm section 70. For this reason, it is possible to reduce the space occupied by the optical diaphragm portion as compared with the conventional case where a plurality of optical diaphragms are separately provided.

  Moreover, since the aperture drive mechanism 60 can be reduced in size, the imaging mechanism 3 can be reduced in size, and the insertion portion inserted into the object in the endoscope apparatus 1 can be reduced in diameter.

  Further, the actuator 62 is expanded and contracted to move the driven member 63 on the driving member 61, and the driven member 63 is stopped at an arbitrary position on the driving member 61, thereby opening the light passage opening in the optical aperture section 70. The aperture can be set to a desired size between the maximum aperture diameter d1 and the minimum aperture diameter d2.

  Further, in order to move the moving optical system 80 forward and backward, a drive mechanism similar to the diaphragm drive mechanism 60 described above is employed. For this reason, the imaging mechanism 3 can be further reduced in size.

(Second Embodiment)
Next, an endoscope apparatus according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is an exploded perspective view showing a part of the configuration of the endoscope apparatus of the present embodiment. FIG. 9 is an exploded perspective view showing a part of the configuration of the endoscope apparatus according to the present embodiment.
As shown in FIGS. 8 and 9, the endoscope apparatus 300 includes an aperture driving mechanism 260 instead of the aperture driving mechanism 60. The diaphragm drive mechanism 260 includes an actuator 62 and a drive member 61 similar to those of the endoscope apparatus 1 of the first embodiment.

A driven member 263 is frictionally engaged with the outer peripheral surface of the driving member 61 instead of the driven member 63. The driven member 263 includes a friction engagement portion 64, an elastic member 67, and an attachment 67a, similarly to the driven member 63 of the first embodiment. Further, the driven member 263 has a main body portion 265 instead of the main body portion 65.
The main body 265 is configured in a substantially cylindrical shape having both ends opened in the direction of the optical axis O1 in the same manner as the main body 65 of the first embodiment. Further, the main body 265 is formed with long holes 265a and 265b formed to face in the radial direction and long holes 265c and 265d formed to face in the radial direction.

As shown in FIG. 9, the endoscope apparatus 300 includes a driven member 263 instead of the driven member 63, and the driven member 263 has a main body portion 265 instead of the main body portion 65.
The diaphragm drive mechanism 260 includes an optical diaphragm unit 270 instead of the optical diaphragm unit 70 of the first embodiment. The optical diaphragm 270 is provided with a support 171 instead of the support 71. The support 171 is formed in a substantially disk shape that can be fixed to the cap 32 shown in FIG. 8, and a through hole 171a through which the optical axis O1 passes is formed.

  The support body 171 is provided with a pair of light shielding members 273a and 273b that can be opposed to each other in a straight line direction across the optical axis O1 within a plane orthogonal to the optical axis O1. Further, the support 171 is formed with a recess having a predetermined depth w1, and the light shielding members 273a and 273b are fitted into the recess 171d formed with the recess.

  The light shielding member 273a has connecting portions 270a that are inserted into the long holes 171b and 171c of the support body 171, and each of the connecting portions 270a is formed in the main body portion 265 of the driven member 263 by the protrusion 2701a. 265c and 265d are engaged.

Further, the light shielding member 273b has connecting portions 270b inserted into the long holes 171b and 171c of the support body 171, and each of the connecting portions 270a is formed on the main body portion 265 of the driven member 263 by the protrusion 2701b. The long holes 265a and 265b are engaged.
The long holes 265a, 265b, 265c, 265d and the projections 2701a, 2701b constitute a cam portion (power conversion mechanism 266).

  Further, the light shielding members 273a and 273b are formed with protrusions 274a to 277a and 274b to 277b that slide with respect to the support 171, respectively. The light shielding members 273a and 273b slide on the support 171 by the protrusions 274a to 277a and 274b to 277b.

  FIGS. 10A to 11B are side views for explaining the operation of the endoscope apparatus 300. Also in this embodiment, similarly to the endoscope apparatus 1 of the first embodiment, the driven member 263 moves forward and backward along the outer surface of the driving member 61 by the expansion / contraction operation of the actuator 62. Then, the light shielding members 273a and 273b are opposed to each other by the long holes 265a, 265b, 265, and 265d formed in the main body 265 of the driven member 263.

  At this time, each of the light shielding members 273a and 273b is pressed and moved at two positions separated by the respective long holes 265c and 265d formed in the main body 265 of the driven member 263. Due to the opposing operation of the light shielding members 273a and 273b, the opening diameter of the light passage opening along the optical axis O1 is the maximum opening diameter d5 (see FIG. 10A) and the minimum opening diameter d6 (see FIG. 10B). Change continuously between.

  Furthermore, in the present embodiment, the light shielding members 273a and 273b are slid and moved while the protrusions 274a to 277a and 274b to 277b are in contact with the support 171. Projections 274a to 277a and 274b to 277b are arranged at the four corners of the light shielding members 273a and 273b, respectively. For this reason, the twist of the light shielding members 273a and 273b due to the sliding resistance between the protrusions 274a to 277a, 274b to 277b and the support 171 is suppressed. As a result, the light shielding members 273a and 273b can smoothly slide on the support 171.

  Further, in the present embodiment, the size of the light passage opening can be changed by the opposing operation of the light shielding member 273a and the light shielding member 273b, so the number of components for changing the diameter of the light passage opening is small. For this reason, the aperture driving mechanism 260 can be reduced in size.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1,300 Endoscope apparatus 3 Imaging mechanism 4 Operation part 60, 260 Aperture drive mechanism 61 Drive member 62 Actuator 63, 263 Driven member 66, 266 Power conversion mechanism (cam part)
70, 270 Optical diaphragm 71, 171 Support 73a, 73b, 73c, 73d, 73e, 73f, 73g, 73h, 273a, 273b Light-shielding member 80 Moving optical system 81 Second drive member 82 Second actuator 92 Solid-state image sensor

Claims (7)

An actuator that can be extended and contracted;
A drive member connected to the actuator;
A driven member frictionally engaged with the driving member;
An optical diaphragm that operates along a plane perpendicular to the central axis of the drive member;
A power conversion mechanism that converts an advance / retreat operation of the driven member along the drive member into an operation of the optical aperture section in the plane orthogonal to the central axis;
A diaphragm drive mechanism comprising: The optical aperture section is
A support disposed along the surface;
A light shielding member that changes the size of the light passage port by a relative rotation operation around the optical axis with the support;
Have
The power conversion mechanism includes a cam portion that converts the forward / backward movement of the driven member into a rotational motion along the surface and transmits the rotational motion to the optical aperture portion.
The aperture driving mechanism according to claim 1. The optical aperture section has a light shielding member that changes the size of the light passage opening by the opposing operation in a straight line direction orthogonal to the optical axis in the plane,
The power conversion mechanism includes a cam portion that converts the forward / backward movement of the driven member into the facing operation and transmits the converted movement to the optical aperture portion.
The aperture driving mechanism according to claim 1.   The diaphragm drive mechanism according to claim 1, wherein the actuator expands and contracts in a central axis direction of the drive member.   The diaphragm drive mechanism according to claim 1, wherein the actuator includes a piezoelectric element having a longitudinal direction and a lateral direction when viewed from the side, and uses the longitudinal direction of the piezoelectric element. A drive unit for extending and retracting the actuator;
The aperture drive mechanism according to claim 1, wherein the drive unit gradually changes an expansion / contraction operation speed of the actuator. A sheath having a distal end and a proximal end and extending axially;
An imaging mechanism arranged at the distal end of the sheath to capture an image of an object;
An operation unit disposed at a proximal end of the sheath for operating the imaging device;
With
The imaging mechanism is
The diaphragm drive mechanism according to any one of claims 1 to 6,
A solid-state imaging device disposed coaxially with the optical axis;
A second drive member disposed parallel to the axis of the drive member;
A second actuator capable of expanding and contracting;
Frictionally engaged with the second drive member and disposed coaxially with the optical axis between the diaphragm drive mechanism and the solid-state image sensor, and focuses the light traveling from the light passage port to the solid-state image sensor. A moving optical system to change,
Having
Endoscopic device.

Images