JP4875420B2 - Endoscopic imaging device - Google Patents

Description

  The present invention relates to an endoscope imaging apparatus that applies an electrostatic actuator as a drive source of an optical lens.

  An imaging apparatus using an electrostatic actuator as a driving source of an optical lens in a conventional endoscope imaging apparatus, which is driven forward and backward by a piezoelectric element, an electrostatic vibration substrate, and a moving body, and is connected to the optical lens. There is an imaging unit having a moving lens frame.

Hereinafter, for example, it is driven back and forth by a piezoelectric element, an electrostatic vibration substrate, and a moving body represented by an imaging unit described in Japanese Patent Application Laid-Open No. 2004-304942 (Patent Document 1), and connected to the optical lens. An example of a conventional imaging unit having a moving lens frame will be described.
FIG. 14 is a sectional view taken along the optical axis of the lens in the example of the conventional imaging unit as described above , and FIG. 15 is a sectional view taken along the line DD in FIG.

  As shown in FIG. 14, the conventional imaging unit 101 is held by a fixed lens frame 112 and can be moved back and forth along the optical axis O (lens optical axis) direction with the first group lens 114 to which the diaphragm 115 is attached. Second lens group 117 held by moving lens frame 116, electrostatic actuator 110, CCD unit 130, fixed lens frame 112, moving lens frame 116, cylindrical body 111 supporting CCD unit 130, and electrostatic actuator 110 includes a storage frame 126 that stores 110, and a heat shrinkable tube 129 that covers the entire imaging unit 101.

  The CCD unit 130 is a unit arranged behind the second group lens 117, and is connected to the CCD mask 109, the cover glass 103, the CCD 102 as the image pickup device, and the CCD 102, and the IC image pickup circuit 104 and the capacitor 105 are mounted thereon. Mounting board 106 and a cable 108 connected to mounting board 106.

  The electrostatic actuator 110 includes a vibrator 125 made of a piezoelectric element, an electrostatic vibration substrate 119 coupled to the vibrator 125 and having an electrode surface, and an electrode surface in contact with the electrode surface of the electrostatic vibration substrate 119. Movable movable body 120, vibrator 125, electrostatic vibration substrate 119, cables 127, 128a, 128b connected to movable body 120, and electrostatic vibration substrate 119 are always energized in the direction of optical axis O. A biasing spring 124 and a pressing spring 121 that biases the moving body 120 toward the electrostatic vibration substrate 119 via the bearing ball 122 are provided.

  The electrostatic vibration substrate 119 is coated with an insulating coating except for the cable connection portion to prevent an electrical short circuit. Further, since the moving body 120 is pressed against the electrostatic vibration substrate 119 by the urging force of the pressing spring 121, the moving body 120 is held stationary except during forward / backward driving.

  In the imaging unit 101 having the above-described configuration, when a voltage is applied to the electrostatic vibration substrate 119 and the moving body 120 in synchronization with the vibration of the electrostatic vibration substrate 119 by the vibrator 125, the moving body 120 has the optical axis O. Move forward or backward in direction. Since the connecting rod 118 of the moving lens frame 116 is fitted on the upper surface side of the moving body 120, the moving lens frame 116 moves forward and backward in the optical axis O direction together with the moving body 120.

As shown in FIG. 15, the size of the outer shape of the cross section orthogonal to the optical axis O of the imaging unit 101 is determined by the outer shape of the cylindrical body 111 holding the moving lens frame 116, and the lower portion is the electrostatic vibration substrate 119. And the width of the storage frame 126 that stores the vibrator 125.
JP 2004-304942 A

  According to the above-described conventional imaging unit 101, the electrostatic vibration substrate 119 and the vibrator 125 having a large occupied area are arranged at a position away from the optical lens, and the portion has a shape having the edge portions C11 and C12 on a business trip. (FIG. 15). The edge portions C11 and C12 cannot be cut into a chamfered side because the electrostatic vibration substrate 119 is a thin plate member, and cutting the vibrator 125 also reduces the piezoelectric performance. It is not preferable. Therefore, when the imaging unit 101 having the edge portions C11 and C12 described above is housed in the distal end of the insertion portion of the endoscope, the distal end portion may become large.

  Further, in the electrostatic actuator unit 110, since the connecting portions of the cables 127, 128a, and 128b are arranged on the cylindrical body 111 side of each component member, the space for connection is increased, and the electrostatic actuator unit 110 is compact. It was hindered.

  The present invention has been made in order to solve the above-described problems, and is capable of reducing the size of the endoscope, further reducing the required space for connecting the drive cable, and reducing the size of the endoscope. An object is to provide an apparatus.

The first endoscope imaging apparatus of the present invention is an endoscope imaging apparatus including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction. A movable body that is coupled to a coupling rod extending from a lens frame that holds the lens, and that moves the optical lens in the optical axis direction by moving in the direction of its own optical axis ; and a peripheral surface of the optical lens and the movable body In the meantime , the movable body is arranged so as to be able to come into contact with the moving body by electrostatic adsorption at a predetermined timing, and is brought into contact with a vibrator constituted by a piezoelectric element. An electrostatic vibration substrate that can be moved in the axial direction, wherein the electrostatic vibration substrate is formed with an insertion portion through which the connecting rod is movably inserted in the optical axis direction, and extends backward from the movable body. However, under Having an extending portion for forming a space for wire cable, the movable body, characterized in that it has a biasing means for biasing the moving body with respect to the electrostatic vibration substrate.

The second endoscope imaging apparatus of the present invention is an endoscope imaging apparatus including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction. Two movable bodies that are connected to a connecting rod extending from a lens frame that holds the lens, and that move in the optical axis direction by moving in the optical axis direction of the lens, and are sandwiched between the two movable bodies, The movable body is arranged so as to be able to come into contact with the moving body by electrostatic adsorption at a predetermined timing, and is brought into contact with a vibrator constituted by a piezoelectric element, and the moving body is moved in the optical axis direction by vibration of the vibrator An electrostatic vibration substrate that can be inserted into the electrostatic vibration substrate so as to be movable in the direction of the optical axis. Pair with electro-vibration board It characterized in that it has a biasing means for biasing Te.

The third endoscope imaging apparatus of the present invention is an endoscope imaging apparatus including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction. The electrostatic actuator includes the optical actuator. Two moving bodies connected to a connecting rod extending from a lens frame that holds the lens and moving the optical lens in the optical axis direction by moving in the direction of the optical axis, and a position covering the two moving bodies The movable body is arranged so as to be able to come into contact with the moving body by electrostatic adsorption at a predetermined timing, and is brought into contact with a vibrator constituted by a piezoelectric element. An electrostatic vibration substrate that can be moved to the electrostatic vibration substrate, wherein the electrostatic vibration substrate is formed with an insertion portion through which the connection rod is movably inserted in the optical axis direction. Electrostatic vibration It characterized in that it has a biasing means for biasing the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device for endoscopes which can suppress the external shape small, and also can reduce the space required for the connection of the drive cable can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view taken along the lens optical axis of an imaging unit that is an endoscope imaging apparatus according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a cross-sectional view of the distal end of the endoscope insertion portion in which the imaging unit is incorporated. FIG. 4 is a perspective view of an assembled state of the electrostatic actuator applied to the imaging unit.

  In the following description, the optical axis direction along the optical axis O of the optical lens of the imaging unit is H0, the subject side in the H0 direction is the front, and the imaging element side is the rear. The side on which the electrostatic actuator is arranged with respect to the optical axis O side of the imaging unit is defined as the lower side.

  The imaging unit 1 of the present embodiment is an optical lens that is held by a fixed lens frame 12 as shown in FIG. 1 and to which a diaphragm 15 is attached, and includes a first group lens 14 disposed on an optical axis O, A movable lens frame 16 capable of moving back and forth along the optical axis O direction, a second group lens 17 as an optical lens held by the moving lens frame 16, an electrostatic actuator 10 for driving the moving lens frame 16 forward and backward, A CCD unit 8 serving as an image sensor disposed behind the second group lens 17, a fixed lens frame 12, a moving lens frame 16, a cylinder 11 that houses the CCD unit 8, and a heat shrinkable tube 29 that covers the entire image pickup unit 1. It consists of.

  The moving lens frame 16 is provided with a connecting rod 16 a that protrudes downward, and the distal end of the connecting rod 16 a is fitted into the fitting hole 20 a of the moving body 20. Therefore, when the moving body 20 moves back and forth in the optical axis O direction, the moving lens frame 16 moves together. The cylindrical body 11 is provided with an opening 11a through which the connecting rod 16a is inserted.

  The CCD unit 8 is a unit arranged behind the second group lens 17 and includes a CCD mask 7, a cover glass 3, and a CCD 2 that is an image pickup device, and is further connected to the CCD 2 for IC imaging. The circuit 4 includes a mounting board 6 on which a capacitor 5 is mounted, and a cable 9 having lead wires 9 a connected to the mounting board 6 and lead wires 27, 28 a, 28 b connected to the electrostatic actuator 10.

  The electrostatic actuator 10 is disposed on the lower surface side of the electrostatic vibration substrate 19 and the vibrator 25 made of a laminated piezoelectric element, the electrostatic vibration substrate 19 coupled to the front surface side of the vibrator 25 and having an electrode surface. A movable body 20 that is in contact with the electro-vibration substrate 19 through the electrode surface and is movable, lead wires 27, 28a, and 28b, and an urging spring 24 that constantly urges the electrostatic vibration substrate 19 toward the vibrator side. And a ball biasing spring 21 that is a biasing member that biases the moving body 20 toward the electrostatic vibration substrate 19 via the bearing ball 22, and a storage frame 26 that houses the electrostatic actuator 10.

  The storage frame 26 has a box shape made of a conductive material, and is fitted and attached to the bottom surface of the cylindrical body 11 in a state where the vibrator 25, the electrostatic vibration substrate 19, and the moving body 20 are stored. A lead wire 28b is electrically connected to the rear upper surface of the storage frame 26.

  The electrostatic vibration substrate 19 is made of a member in which a conductive film is formed on an insulating material. The lower surface portion of the electrostatic vibration substrate 19 becomes an electrode portion 19 f (FIG. 4) in contact with the moving body 20, and has a shape that extends rearward longer than the moving body 20. The lower surface portion of the extending portion 19b becomes a wiring cable space portion, and the lead wire 28a is electrically connected. The portions other than the connecting portion of the lead wires are insulated with a silicon oxide film to prevent an electrical short circuit with other members.

  As shown in FIG. 4, the electrostatic vibration substrate 19 is provided with a notch 19 a along the optical axis O direction through which the connecting rod 16 a of the moving lens frame 16 is inserted. Accordingly, the moving body 20 and the connecting rod 16a are not prevented from moving back and forth in the direction of the optical axis O by the electrostatic vibration substrate 19.

  Further, the electrostatic vibration substrate 19 receives a biasing force directed rearward by the biasing spring 24 at the front end surface portion and is in contact with the vibrator 25.

  In the vibrator 25, lead wires 27 are electrically connected to both side surfaces of the rear end portion, and the front end surface is in contact with the electrostatic vibration substrate 19.

  The moving body 20 is made of a conductive material, and has an electrode portion 20f (FIG. 4) that comes into contact with the electrode portion 19f on the lower surface of the electrostatic vibration substrate 19 on the upper surface portion. A joint hole 20a is provided. A recess 20b into which the ball urging spring 21 and the bearing ball 22 are inserted is provided on the lower surface portion. The recess 20b is arranged at the center bottom avoiding chamfered portions 20d and 20e described later.

  The bearing ball 22 is made of a conductive member, and similarly abuts against the storage frame 26 of the conductive member by the biasing force of the ball biasing spring 21 of the conductive member. Therefore, the voltage applied to the storage frame 26 is transmitted to the electrode portion 19 f of the moving body 20 via the ball biasing spring 21 and the bearing ball 22. Further, the electrode portion 20f of the moving body 20 is pressed against the electrode portion 19f of the electrostatic vibration substrate 19 by an appropriate urging force of the ball urging spring 21, and the moving body 20 is held in a stationary state except during forward / backward driving. The

  Chamfered portions 20d and 20e are formed on both sides of the lower surface portion of the moving body 20 (FIG. 2). In order to maintain the electrostatic attraction force with the electrostatic vibration substrate 19, the area of the electrode portion 20f of the moving body 20 cannot be reduced. However, by providing the chamfered portions 20d and 20e as described above, the outer shape of the heat-shrinkable tube 29 including the storage frame 26 at the distal end of the endoscope insertion portion is reduced without reducing the width of the electrode portion 20f of the moving body 20. Chamfered corners C1 and C2 can be formed on both sides (FIG. 2). Therefore, it becomes easy to arrange the imaging unit 1 at the distal end of the small-diameter endoscope insertion portion as will be described later.

  As shown in the cross-sectional view of FIG. 3, two light guides 32 a and 32 b, an air / water supply tube 33, a forceps channel 34, and the imaging unit 1 are arranged at the endoscope insertion portion distal end 30. It is attached to the endoscope insertion portion with four fixing screws 31a to 31d.

  As described above, since the imaging unit 1 has the chamfered corner portions C1 and C2 formed on its outer shape, the imaging unit 1 is extremely close to the fixing screw 31a and the forceps channel 34 in the distal end 30 of the compact endoscope insertion portion. Can be stored. Therefore, it is possible to reduce the diameter and the size of the endoscope insertion portion in which the imaging unit 1 is incorporated.

  The advance / retreat operation of the electrostatic actuator 10 in the imaging unit 1 having the above-described configuration will be described using the advance / retreat operation state diagram of FIG.

  In the electrostatic actuator 10, an electrostatic force is generated by applying a voltage to the electrostatic vibration substrate 19 and the moving body 20, the timing at which the electrostatic vibration substrate 19 and the moving body 20 are attracted, and a driving voltage is applied to the vibrator 25. The moving lens frame 16 can be moved back and forth in the H0 direction in combination with the timing of moving the electrostatic vibration substrate 19. Hereinafter, an example of the driving method will be described with reference to FIG.

  First, when moving the moving lens frame 16 forward in the H0 direction, when a high positive voltage and a negative voltage are respectively applied to the lead wires 28a and 28b in the A1 state which is the initial state of FIG. Then, the electrode portion 19f of the electrostatic vibration substrate 19 is charged to a positive potential. On the other hand, the negative voltage charges the electrode portion 20 f of the moving body 20 to a negative potential from the storage frame 26 via the bearing ball 22 and the ball biasing spring 21. The electrostatic vibration substrate 19 and the moving body 20 are attracted by static electricity.

  Therefore, when a driving voltage is applied to the vibrator 25 by the lead wire 27, the vibrator 25 expands as shown in the A2 state, and the tip position P25A of the vibrator 25 moves to P25B. Therefore, the electrostatic vibration substrate 19 also moves from the tip position P19A to P19B. At this time, since the electrostatic vibration substrate 19 and the moving body 20 are attracted to each other, the moving body 20 moves forward together with the electrostatic vibration substrate 19, and the moving lens frame 16 moves from the tip positions P16A to P16B via the connecting rod 16a. Move to.

  Subsequently, when the voltage applied to the lead wires 28a and 28b is cut, the electrostatic vibration substrate 19 and the moving body 20 are switched to a free state. When the drive voltage of the lead wire 27 is turned off, as shown in the A3 state, the vibrator 25 contracts, so that the movable body 20 and the moving lens frame 16 remain at the position of the A3 state. In response to the urging force of the urging spring 24, it returns to its tip position P19A.

  By the operation in the A3 state from the A1 state to the A2 state, the moving lens frame 16 has advanced by one step to the tip position P16B. By repeating such an operation, for example, as shown in the A4 state, the moving lens frame 16 can be moved to an arbitrary tip position P16C.

  On the other hand, when the moving lens frame 16 is moved rearward in the H0 direction, first, the voltage applied to the lead wires 28a and 28b is turned off with the A3 state in FIG. Put it in a state. When a drive voltage is applied to the lead wire 27, the vibrator 25 expands and the electrostatic vibration substrate 19 moves to the tip position P19B shown in the A2 state. However, since the space between the electrostatic vibration substrate 19 and the moving body 20 is in a free state, the moving lens frame 16 stops at the tip position P16B.

  Subsequently, when a high voltage is applied to the lead wires 28a and 28b, the electrode portions of the electrostatic vibration substrate 19 and the moving body 20 are in a suction state, and when a drive voltage is further applied to the lead wire 27, the vibrator 25 is As shown in the A1 state, the electrostatic vibration substrate 19 is retracted to its tip position P19A by the biasing force of the biasing spring 24. At this time, since the electrode portions of the electrostatic vibration substrate 19 and the moving body 20 are in the suction state, the moving lens frame 16 moves backward by one step from the tip position P16B to the tip position P16A. By repeating such an operation, the movable lens frame 16 can be retracted to an arbitrary position.

  According to the imaging unit 1 of the present embodiment described above, the storage frame 26 that stores the electrostatic actuator 10 is attached to the bottom surface of the cylinder 11 that stores the optical lens and the CCD unit 8. Assembling work becomes easier.

  Further, the electrostatic vibration substrate 19 and the vibrator 25 having a large outer shape are disposed in the vicinity of the optical lens side, the electrode portion 20f of the moving body 20 is disposed on the lower side, and the thick central portion of the moving body 20 is disposed. An urging mechanism including a ball urging spring 21 for urging the moving body 20 and a bearing ball 22 is provided to reduce the overall size including the electrostatic actuator 10.

  The lower side surfaces of the movable body 20 that are not involved in the width of the electrode surface 20f with respect to the electrostatic vibration substrate 19 are chamfered portions 20d and 20e, so that a chamfered corner is formed at the lower portion of the outer shape of the storage frame 26 and the heat shrinkable tube 29. Portions C1 and C2 can be formed. The imaging unit 1 having the chamfered corner portions C1 and C2 can be stored in the endoscope insertion portion distal end 30 having a small diameter without generating a useless space.

  Further, in order to improve the wiring space efficiency, the lead wire 28a is electrically connected to the lower surface portion of the extending portion 19b behind the electrostatic vibration substrate 19 caused by the difference in length from the moving body 20. Therefore, the occupied space for wiring is reduced, and the imaging unit 1 can be further downsized.

Next, an electrostatic actuator applied to an imaging unit which is an endoscope imaging apparatus according to the second embodiment of the present invention will be described with reference to FIGS.
FIG. 6 is a cross-sectional view along the lens optical axis around the electrostatic actuator of the imaging unit of the present embodiment. FIG. 7 is a perspective view of the assembled state of the electrostatic actuator.

  The electrostatic actuator 10A of the imaging unit of the present embodiment is provided with a through hole in the electrostatic vibration substrate with respect to the electrostatic actuator 10 in the first embodiment, and a convex portion (projection) of the moving body is provided in the through hole. The structure is different in that it is inserted and a fitting hole and a spring urging mechanism are arranged on the convex portion. Other configurations are the same as those of the electrostatic actuator 10. Hereinafter, the same constituent members are denoted by the same reference numerals, and different portions will be described.

  As shown in FIGS. 6 and 7, the electrostatic actuator 10A of the present embodiment houses the electrostatic vibration substrate 39, the vibrator 25, the moving body 38 that drives the moving lens frame 37 forward and backward, and the electrostatic actuator 10A. And a storage frame 26.

  The electrostatic vibration substrate 39 is made of an insulating material in the same manner as the electrostatic vibration substrate 19, has a conductor film formed on the surface, and is coated with an insulating coating with a silicon oxide film except for the connection portion of the lead wire. .

  The electrostatic vibration substrate 39 has a through hole 39a that forms an insertion groove and an extending portion 39b that extends rearward from the moving body 38. In the electrostatic vibration substrate 39, an electrode surface 39f is formed on the lower surface portion excluding the through hole 39a and the lead wire connecting portion on the lower surface of the extending portion 39b.

  Similar to the moving body 20, the moving body 38 is made of a conductive material, and is provided with a projection (projection) 38c that fits into the through hole 39a and is relatively movable in the H0 direction. The convex portion 38c is provided with a fitting hole 38a into which the connecting rod 37a of the moving lens frame 37 is fitted, and a concave portion 38b opened on the lower surface side. An electrode surface 38f is formed on the upper surface portion other than the convex portion 38c. Chamfered portions 38 d and 38 e are provided on both side surfaces of the lower surface portion of the moving body 38.

  A ball biasing spring 21 and a bearing ball 22 that are biasing members made of a conductive member are inserted into the recess 38b. The bearing ball 22 abuts on the storage frame 26 by the urging force of the ball urging spring 21, the moving body 38 is urged upward, and the electrode surface 38 f abuts on the electrode surface 39 f of the electrostatic vibration substrate 39.

  Also in the electrostatic actuator 10A of the imaging unit of the present embodiment having the above-described configuration, when the moving lens frame 37 is driven forward and backward, by applying a voltage to the electrostatic vibration substrate 39 and the moving body 38 as in the electrostatic actuator 10. The moving lens frame 37 has a combination of a timing of generating an electrostatic force to attract the electrostatic vibration substrate 39 and the moving body 38 and a timing of applying a driving voltage to the vibrator 25 and moving the electrostatic vibration substrate. Moves forward and backward in the direction of H0.

  The image pickup unit of the present embodiment also has the same effect as the image pickup unit 1, but in particular, since the convex portion 38 c of the moving body 38 is inserted into the through hole 39 a of the electrostatic vibration substrate 39, it moves by its insertion dimension. The thickness of the body 38 can be reduced. Therefore, the entire imaging unit including the electrostatic actuator 10A can be thinned, and the diameter of the distal end of the endoscope insertion portion in which the imaging unit is incorporated can be further reduced.

Next, an electrostatic actuator applied to an imaging unit which is an endoscope imaging apparatus according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 8 is a cross-sectional view along the lens optical axis around the electrostatic actuator in the imaging unit of the present embodiment.

  The electrostatic actuator 10B in the imaging unit of the present embodiment is different from the electrostatic actuator 10 of the first embodiment in that two moving bodies that sandwich the electrostatic vibration substrate are arranged. Other configurations are the same as those of the electrostatic actuator 10. Hereinafter, the same reference numerals are given to the same components, and different parts will be described.

  As shown in FIG. 8, the electrostatic actuator 10 </ b> B of the imaging unit of the present embodiment includes two moving bodies 41 and 42 that drive the moving lens frame 16 </ b> B made of an electrostatic vibration substrate 45, a vibrator 25, and a conductive member. And a storage frame 26.

  The electrostatic vibration substrate 45 is made of a silicon material on which a conductor film is formed, and further, the surface other than the electrode surface described later is insulatively coated with a silicon oxide film as an insulating material. The electrostatic vibration substrate 45 is provided with a through hole 45 a serving as an insertion groove, and has an extending portion 45 b extending rearward from the moving body 41. The lower surface portion of the extending portion 45b serves as a lead wire connecting portion to which the lead wire 28a is electrically connected. A lower electrode surface 45f is formed on the lower surface excluding the through hole 45a and the lead wire connecting portion, and an upper electrode surface 45g is formed on the upper surface excluding the through hole 45a.

  The two moving bodies 41 and 42 are both made of a conductive material. Among them, one moving body 41 is provided with a convex portion (projecting portion) 41c inserted into the through hole 45a and a relief concave portion 41d for a convex portion 42b (described later). The protrusion 41c is provided with a fitting recess 41a on the upper surface side and a recess 41b opening on the lower surface side. An electrode surface 41f is formed on the upper surface portion other than the convex portion 41c and the concave portion 41d. Further, chamfered portions (not shown) are provided on both side surfaces of the lower surface portion of the moving body 41 as in the moving body 20, and further, a cut for electrically connecting the lead wire 28b to the lower surface of the rear end portion. A planar connection portion 41e is provided.

  A ball urging spring 43a and a bearing ball 44a, which are urging members, are inserted into the recess 41b. The bearing ball 44a abuts on the storage frame 26 by the urging force of the ball urging spring 43a, the moving body 41 is urged upward, and the electrode surface 41f abuts on the lower electrode surface 45f of the electrostatic vibration substrate 45.

  A conductive elastic member 46a having a concave portion is fitted into the fitting concave portion 41a. The tip of the connecting rod 16Ba of the moving lens frame 16B is fitted into the concave portion of the conductive elastic member 46a. As the conductive elastic member 46a, for example, a member obtained by plating the surface of an elastic member such as a rubber member is applied.

  The other moving body 42 is provided with a through hole 42a and a lower convex portion (projecting portion) 42b, and the convex portion 42b is provided with a concave portion 42c that opens to the upper surface side. An electrode surface 42g is formed on the lower surface portion other than the convex portion 42b.

  A conductive elastic member 46b having a fitting hole is fitted into the through hole 42a. The connecting rod 16Ba of the moving lens frame 16B made of a conductive member is inserted into the fitting hole of the conductive elastic member 46b. After the insertion, the connecting rod 16Ba is inserted into the concave portion of the conductive elastic member 46a of the moving body 41 as described above. The conductive elastic member 46b may be a member obtained by plating the surface of an elastic member such as a rubber member in the same manner as the conductive elastic member 46a.

  A ball urging spring 43b and a bearing ball 44b, which are urging members, are inserted into the recess 42c. The bearing ball 44b abuts on the bottom surface of the cylindrical body 11 by the urging force of the ball urging spring 43b, the moving body 42 is urged downward, and the electrode surface 42g abuts on the upper electrode surface 45g of the electrostatic vibration substrate 45. . Therefore, the electrostatic vibration substrate 45 is supported in a state where the upper and lower electrode surfaces 45g and 45f are sandwiched between the electrode surfaces 42g and 41f of the moving bodies 42 and 41.

  When a voltage is applied to the moving body 41 via the lead wire 28b, the applied voltage is applied from the moving body 41 via the conductive elastic member 46a to the conductive elastic member 46b on the moving body 42 side via the connecting rod 16Ba. It is transmitted and applied to the moving body 42.

  In this embodiment, the movable lens frame 16B is formed of a conductive member. However, the storage frame 26, the ball urging springs 43a and 43b, and the bearing balls 44a and 44b are not necessarily formed of a conductive member. Absent.

  When the movable lens frame 16B is driven forward / backward by the electrostatic actuator 10B of the imaging unit of the present embodiment having the above-described configuration, the electrostatic vibration substrate 45 and two movements sandwiching the substrate via the lead wires 28a and 28b. A voltage is applied to the bodies 41 and 42 at a certain timing to generate an electrostatic force, and the electrostatic vibration substrate 45 is adsorbed while being sandwiched between the moving bodies 41 and 42. The moving lens frame 16B can be moved back and forth in the H0 direction by a combination of the suction timing and the moving timing of the electrostatic vibration substrate 45 by applying a driving voltage to the vibrator 25 via the lead wire 27.

  According to the electrostatic actuator 10B of the imaging unit of the present embodiment, the electrostatic vibration substrate 45 is sandwiched between the upper and lower moving bodies 41 and 42 as described above to generate an electrostatic force. The electrostatic force per unit area is increased, and the length and / or width of the electrostatic vibration substrate 45 and the moving bodies 41 and 42 can be reduced. Therefore, the outer shape of the electrostatic actuator 10B can be compactly integrated, and the diameter of the distal end of the endoscope insertion portion that houses the electrostatic actuator 10B can be further reduced.

  Further, in the electrostatic actuator 10B, the cut-surface-shaped lead wire connecting portion 41e is arranged on the lower rear surface of the moving body 41. Therefore, in addition to the connecting portion of the lead wire 28a, the connecting portion of the lead wire 28b is also efficient in a small space. Can be arranged. In addition, the same effects as the electrostatic actuator 10 can be obtained.

Next, an electrostatic actuator applied to an imaging unit that is an endoscope imaging apparatus according to a fourth embodiment of the present invention will be described with reference to FIGS.
FIG. 9 is a cross-sectional view along the lens optical axis around the electrostatic actuator of the imaging unit of the present embodiment. FIG. 10 is a cross-sectional view taken along the line BB in FIG. 9, and the CC cross section in the drawing corresponds to the cross section in FIG.

  The electrostatic actuator 10C in the imaging unit of this embodiment is different from the electrostatic actuator 10 of the first embodiment in that two U-shaped moving bodies are arranged inside the through hole of the electrostatic vibration substrate. ing. Other configurations are the same as those of the electrostatic actuator 10. Hereinafter, the same reference numerals are given to the same components, and different parts will be described.

  As shown in FIGS. 9 and 10, the electrostatic actuator 10C of the imaging unit of the present embodiment is insulated from the two movable bodies 51 and 52 that drive the forward and backward movement of the electrostatic vibration substrate 55, the vibrator 25, and the movable lens frame 16C. A storage frame 26 made of a body is provided.

  The electrostatic vibration substrate 55 is made of a silicon material on which a conductor film is formed. Further, the surface other than the electrode surface described later is insulatively coated with a silicon oxide film as an insulating material. The electrostatic vibration substrate 55 has through holes 55a penetrating vertically. Electrode surfaces 55f and 55g are formed on both inner surfaces of the through hole 55a, and lead wires are connected to the inclined cut surface of the rear side surface portion. A portion 55c is provided, and further, a lead wire insertion hole 55b that penetrates obliquely from the rear toward the through hole 55a is provided. The lead wire 28a is electrically connected to the lead wire connecting portion 55c. The lead wire 28b is inserted into the lead wire insertion hole 55b.

  The electrostatic vibration substrate 55 is biased toward the vibrator 25 by the biasing spring 24. Lead wires 27 a and 27 b are electrically connected to both side surfaces of the vibrator 25.

  The two moving bodies 51 and 52 are both made of a conductive material having a U-shape, and one of the moving bodies 51 is a fitting recess into which the connecting rod 16Ca of the moving lens frame 16C is fitted inside the U-shape. 51a. The U-shaped side surface portion forms the electrode surface 51f. In addition, the moving body 51 is provided with two concave portions 51b and 51c that open at the end face of the U-shaped portion. The concave portions 51b and 51c are respectively provided with bearing balls 53a and 53b made of a conductive material, and an urging force. Ball urging springs 54a and 54b made of a conductive material are inserted.

  The other moving body 52 has a fitting recess 52a into which the moving body 51 is fitted, and the U-shaped side surface portion forms an electrode surface 52g. The moving body 52 is provided with two recesses 52b and 52c that open to the end face of the U-shaped portion. The recesses 52b and 52c are bearing balls 53c and 53d and an urging member, respectively. Ball urging springs 54c and 54d are inserted.

  Note that a notch-shaped lead wire connecting portion 52 e is provided on the bottom surface of the rear end portion of the moving body 52. The lead wire 28b is electrically connected to the lead wire connecting portion 52e.

  In the through hole 55a of the electrostatic vibration substrate 55, the moving body 52 in a state where the moving body 51 is inserted into the recess 52a is inserted. The movable body 52 receives the biasing force of the ball biasing springs 54 c and 54 d and is supported in a state where the electrode surface 52 g is in contact with the electrode surface 55 g of the electrostatic vibration substrate 55. The moving body 51 receives the biasing force of the ball biasing springs 54 a and 54 b, and the electrode surface 51 f is the electrode surface of the electrostatic vibration substrate 55 in a state where the bearing balls 53 a and 53 b are in contact with the bottom surface of the recess 52 a of the moving body 52. It is supported in a state in contact with 55f.

  When a voltage is applied to the moving body 52 via the lead wire 28b, the applied voltage is also applied to the moving body 51 side from the moving body 52 via the bearing balls 53a and 53b and the ball urging springs 54a and 54b. The The storage frame 26 need not be a conductive member.

  When the movable lens frame 16C is driven forward / backward by the electrostatic actuator 10C in the imaging unit of the present embodiment having the above-described configuration, the electrostatic vibration substrate 55 and the substrate of the substrate are moved at a certain timing via the lead wires 28a and 28b. A voltage is applied to the two moving bodies 51 and 52 that are in contact with the through hole 55a to generate an electrostatic force between the electrode surfaces 51f and 55f and between the electrode surfaces 52g and 55g, The moving bodies 51 and 52 are adsorbed. The movable lens frame 16C can be moved back and forth in the H0 direction by a combination of the suction timing and the movement timing of the electrostatic vibration substrate 55 by applying a driving voltage to the vibrator 25 via the lead wires 27a and 27b. .

  According to the electrostatic actuator 10C of the imaging unit of the present embodiment, the moving bodies 51 and 52 are housed in the through hole 55a of the electrostatic vibration substrate 55 as described above, and electrostatic force is generated on both surfaces inside the through hole 55a. As a result, the arrangement space of the movable bodies 51 and 52 in the vertical direction is reduced and the electrode surfaces are two in the width direction, so that the contact surface is increased, and the electrostatic actuator 10C can be further downsized. In addition, since the lead wire connecting portion is also arranged on the inclined cut surface of the side surface of the electrostatic vibration substrate 55 and the bottom notch shape portion of the moving body 52, the occupied space for connecting the lead wire is reduced, and the compactness is easy. become. In addition, the same effects as the electrostatic actuator 10 can be obtained.

Next, an imaging unit that is an endoscope imaging apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS.
FIG. 11 is a cross-sectional view taken along the lens optical axis of the imaging unit of the present embodiment. FIG. 12 is a perspective view of an electrostatic actuator incorporated in the imaging unit. FIG. 13 is a state diagram of the advance / retreat operation of the electrostatic actuator.

  The electrostatic actuator 10D in the imaging unit 1D of the present embodiment does not provide a dedicated moving body for the electrostatic actuator 10 in the first embodiment, and the moving lens frame is formed of a conductive member. It has a function and is configured to abut against the electrostatic vibration substrate by the urging force of the cable pipe that guides the moving lens frame. The configuration of the other imaging unit 1D is the same as that of the imaging unit 1. Hereinafter, the same reference numerals are given to the same components, and different parts will be described.

  The imaging unit 1D of the present embodiment has the same configuration as the imaging unit 1 except for an electrostatic actuator 10D including a moving lens frame 16D as shown in FIG.

  As shown in FIG. 12, the electrostatic actuator 10 </ b> D includes a moving lens frame 16 </ b> D, an electrostatic vibration substrate 61, a vibrator 25 made of a laminated piezoelectric element, and a storage frame 26.

  The moving lens frame 16D is formed of a conductive member and holds the second group lens 17, but has protrusions 16Da and 16Db protruding on both sides at the lower part (FIG. 12). The lower surfaces of the protrusions 16Da and 16Db form an electrode surface 16Df.

  The movable lens frame 16D is supported by the two cable pipes 63 and 64 that are in contact with the upper surfaces of the protrusions 16Da and 16Db so as to be able to advance and retreat. The cable pipes 63 and 64 have lead wires 28a and 28b and lead wires 27a and 27b inserted through the pipe portions, respectively. The cable pipe 63 is provided with a lead wire outlet hole 63a on the side of the pipe portion, and the cable pipe 64 has a leading end opening portion as a lead wire outlet portion. The cable pipe 63 is held in a state where it is urged downward by an urging member (not shown), and the lower electrode surface 16Df of the moving lens frame 16D contacts an electrode surface 61f of the electrostatic vibration substrate 61 described later. Touching.

  The electrostatic vibration substrate 61 is formed of a silicon material covered with a conductive film, and the surface other than the electrode surface described later is further insulation-coated with a silicon oxide film as an insulating material. An electrode surface 61f that contacts the electrode surface 16Df of the moving lens frame 16D is formed on the upper surface of the electrostatic vibration substrate 61 and supported by the biasing spring 24 in a state of being biased to the front vibrator 25 side. ing. The lead wire 28 b led out from the lead wire lead-out hole 63 a of the cable pipe 63 is electrically connected to the electrostatic vibration substrate 61. The lead wire 28a led out from the lead wire lead-out hole 63a is electrically connected to the protrusion 16Da of the moving lens frame 16D.

  The vibrator 62 is arranged behind the electrostatic vibration substrate 61 in contact with the urging force of the urging spring 24. Lead wires 27 a and 27 b led out from the lead wire lead-out holes of the cable pipe 64 are electrically connected to the vibrator 62. The storage frame 26 need not be a conductive member.

  An example of the advance / retreat operation of the moving lens frame 16D by the electrostatic actuator 10D of the imaging unit 1D having the above-described configuration will be described with reference to the advance / retreat operation state diagram of FIG.

  First, when moving the moving lens frame 16D forward in the H0 direction, in the B1 state, which is the initial state of FIG. 13, the applied voltage of the lead wires 28a and 28b is turned off, and the electrostatic vibration substrate 61 and the moving lens frame 16D are turned off. The protrusions 16Da and 16Db are in a free state.

  Subsequently, a drive voltage is applied to the vibrator 62 by the lead wires 27a and 27b, the vibrator 62 is expanded as shown in the B2 state, and the electrostatic vibration substrate 61 is moved from the tip position P61A to P61B. At this time, since the space between the electrostatic vibration substrate 61 and the moving lens frame 16D is in a free state, the moving lens frame 16D remains at the tip position P16DA.

  Then, an applied voltage is applied to the lead wires 28a and 28b, and the electrostatic vibration substrate 61 and the projections 16Da and 16Db of the moving lens frame 16D are brought into an attracting state. Therefore, when the drive voltage of the lead wires 27a and 27b is cut, the vibrator 62 contracts and the electrostatic vibration substrate 61 returns to the tip position P61A as shown in the B3 state. Since the moving lens frame 16D is attracted to the electrostatic vibration substrate 61, it moves together with the electrostatic vibration substrate 61 from the tip position P16DA to P16DB.

  The moving lens frame 16D is advanced by one step from the tip position P16DA to P16DB by the operation in the B3 state from the B1 state to the B2 state. By repeating such an operation, for example, the movable lens frame 16D shown in the B4 state can be moved forward to an arbitrary tip position P16DC.

  On the other hand, when the moving lens frame 16 is moved rearward in the H0 direction, first, a voltage is applied to the lead wires 28a and 28b with the B3 state in FIG. 5 as an initial state, and a high voltage is applied to the electrostatic vibration substrate 61 and the moving lens frame 16D. A voltage is applied to bring both into an adsorption state. When a drive voltage is applied to the lead wires 27a and 27b, the vibrator 62 expands as shown in the B2 state, so that the electrostatic vibration substrate 61 moves from the tip position P61A to P61B. Since the moving lens frame 16D is in the suction state with the electrostatic vibration substrate 61, it moves backward from the tip position P16DB to P16DA.

  Subsequently, when the voltage is cut to the lead wires 28a and 28b, the electrostatic vibration substrate 61 and the moving lens frame 16D are brought into a free state, and the drive voltage is cut to the lead wires 27a and 27b, the vibrator 62 is brought into the B1 state. As shown, it contracts and advances to the rear end position P62A, and the electrostatic vibration substrate 61 also moves forward to its front end position P61A by the biasing force of the biasing spring 24. At this time, since the electrode portions of the electrostatic vibration substrate 61 and the moving lens frame 16D are in a free state, the moving lens frame 16D stops at the tip position P16DA and moves backward by one step. By repeating such an operation, the movable lens frame 16D can be retracted to an arbitrary position.

  According to the imaging unit 1D of the present embodiment, the lead wires are inserted into the cable pipes 63 and 64, and led to the electrical connection portion of the electrostatic vibration substrate 61, the vibrator 62, and the protrusion 16Da of the moving lens frame 16D. Since the structure is adopted, the wiring of the lead wire is easy and the wiring space is also reduced.

  Further, the moving lens frame 16D does not need to be provided with a connecting collar portion, and also serves as a moving body, so that there are few components and a necessary arrangement space is reduced. Further, the bearing ball and the ball biasing spring for bringing the moving lens frame 16D into contact with the electrostatic vibration substrate 61 are not necessary, and an effect that the structure is simplified and the compactness can be realized is obtained. .

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  The endoscope image pickup apparatus according to the present invention can be used as an endoscope image pickup apparatus that can keep the outer shape small, further requires less space for connecting a drive cable, and can be made compact. Is possible.

FIG. 1 is a cross-sectional view taken along the lens optical axis of an imaging unit that is an endoscope imaging apparatus according to a first embodiment of the present invention. It is AA sectional drawing of FIG. It is sectional drawing of the endoscope insertion part front-end | tip in which the imaging unit of FIG. 1 is integrated. It is a perspective view of the assembly state of the electrostatic actuator applied to the imaging unit of FIG. FIG. 2 is a state diagram of an advance / retreat operation of the imaging unit of FIG. 1. It is sectional drawing along the lens optical axis around the electrostatic actuator applied to the imaging unit of 2nd embodiment of this invention. It is a perspective view of the assembly state of the electrostatic actuator of FIG. It is sectional drawing along the lens optical axis around the electrostatic actuator applied to the imaging unit of 3rd embodiment of this invention. It is sectional drawing along the lens optical axis around the electrostatic actuator applied to the imaging unit of 4th embodiment of this invention. It is BB sectional drawing of FIG. It is sectional drawing along the lens optical axis of the imaging unit of 5th embodiment of this invention. It is a perspective view of the electrostatic actuator integrated in the imaging unit of FIG. FIG. 13 is a state diagram of an advance / retreat operation of the electrostatic actuator of FIG. 12. It is sectional drawing along the lens optical axis of the conventional imaging unit. It is DD sectional drawing of FIG.

Explanation of symbols

1,1D
... Imaging unit (imaging device for endoscope)
10, 10A, 10B, 10C, 10D
... Electrostatic actuator 17 ... Second lens group (optical lens)
16a, 16Ba, 16Ca, 37a
... Connecting rod 16D ... Moving lens frame (member also serving as a moving body)
19, 39, 45, 55, 61
... Electrostatic vibration substrate 19b, 39b, 45b
... Extension part 20,38,41,42,51,52
... Moving bodies 21, 43a, 43b, 54a, 54b, 54c, 54d
... Ball biasing spring (biasing member)
38c ... Projection (projection)
39a ... Through hole (insertion groove)

Claims (3)

In an endoscope imaging apparatus including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction.
The electrostatic actuator is coupled to the connecting rod to extend from the lens frame for holding the optical lens, a movable body for moving the optical lens in the optical axis direction by moving to their optical axis direction, of the optical lens Between the peripheral surface and the moving body, the movable body is disposed so as to be able to contact with the moving body by electrostatic adsorption at a predetermined timing, and is also in contact with a vibrator constituted by a piezoelectric element. An electrostatic vibration substrate capable of moving the moving body in the optical axis direction by the vibration of
The electrostatic vibration substrate is formed with an insertion portion through which the connection rod is movably inserted in the optical axis direction, and has an extension portion extending rearward from the movable body and forming a wiring cable space below. Have
The endoscope imaging apparatus , wherein the moving body includes a biasing unit that biases the moving body against the electrostatic vibration substrate . In an endoscope imaging apparatus including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction.
The electrostatic actuator is connected to a connecting rod extending from a lens frame that holds the optical lens, and two moving bodies that move the optical lens in the optical axis direction by moving in the optical axis direction of the electrostatic actuator; The movable body is sandwiched between two movable bodies and arranged so as to be able to come into contact with the movable body by electrostatic adsorption at a predetermined timing, and is brought into contact with a vibrator constituted by a piezoelectric element. An electrostatic vibration substrate capable of moving the moving body in the optical axis direction,
The electrostatic vibration substrate is formed with an insertion portion through which the connecting rod is movably inserted in the optical axis direction.
The two moving bodies have urging means for urging the moving body against the electrostatic vibration substrate.
An endoscope imaging apparatus characterized by the above . In an endoscope imaging apparatus including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction.
The electrostatic actuator is connected to a connecting rod extending from a lens frame that holds the optical lens, and two moving bodies that move the optical lens in the optical axis direction by moving in the optical axis direction of the electrostatic actuator; At a position covering one moving body, the movable body is arranged so as to be able to contact with the moving body by electrostatic adsorption at a predetermined timing, and is also in contact with a vibrator constituted by a piezoelectric element. An electrostatic vibration substrate capable of moving the movable body in the optical axis direction by
The electrostatic vibration substrate is formed with an insertion portion through which the connecting rod is movably inserted in the optical axis direction.
The two moving bodies have urging means for urging the moving body against the electrostatic vibration substrate.
An endoscope imaging apparatus characterized by the above .

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