JP2012152434A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope that is capable of changing the viewing field direction during imaging in a wider range without causing an increase in apparatus size, and facilitates assembly of a drive mechanism for advancing and retracting for the turning movement of an imaging unit.SOLUTION: The endoscope includes: a plurality of recesses formed on surfaces of an imaging holder and a relaying holder; and a plurality of U-shapes formed at a pair of driving rods. The U-shapes are fitted and mounted to the recesses on the imaging holder and the relaying holder, and the imaging unit can turn around two different axes by drive of the advancement and retraction of one of the driving rods.

Description

  The present invention relates to an endoscope that images an inside of a subject that cannot be directly observed from the outside, and more particularly, to an endoscope that can change a visual field direction during imaging.

  Conventionally, in a rigid endoscope having a highly rigid insertion portion, when changing the visual field direction during imaging (observation), the entire insertion portion is displaced inside the subject, or a plurality of insertion portions having different visual field directions are previously provided. It is necessary to prepare, replace as appropriate, and use.

  On the other hand, a technique is known that makes it easy to change the visual field direction at the time of imaging by providing a freely operable curved portion at the distal end region of the insertion portion to which the solid-state imaging device is attached (see Patent Document 1). ).

  In addition, the solid-state imaging device housed at the distal end of the insertion portion is held so as to be rotatable around a predetermined axis, and the solid-state imaging device is inserted via a wire or a rod inserted from the driving device (operation portion) into the insertion portion. A technique is known that allows the viewing direction to be changed during imaging without turning the insertion portion (that is, without requiring a surrounding space) by rotating (see Patent Documents 2 and 3). ).

JP 2005-342010 A JP-A-7-327916 JP 2006-95137 A

  However, in the conventional techniques described in Patent Documents 2 and 3, when the solid-state imaging device is to be rotated around two axes in order to change the visual field direction during imaging in a wider range, the large size of the device is required. In addition to the increase in the diameter (that is, the diameter of the insertion portion), the device configuration around the solid-state imaging device becomes extremely complicated. In addition, since the insertion part for inserting the endoscope into the subject must be downsized, its complicated mechanism must be configured in a narrow space inside the endoscope, making assembly very complicated and difficult. There was a problem of becoming.

  The present invention has been devised in view of such problems of the prior art, and it is possible to change the viewing direction at the time of imaging without increasing the size of the apparatus (that is, increasing the diameter of the insertion portion). An object of the present invention is to provide an endoscope that can be implemented in a range and that facilitates assembling of a mechanism that is driven forward and backward for a rotation operation of an imaging unit.

  An endoscope according to the present invention includes an imaging unit that captures a subject image, an imaging holder that holds the imaging unit, and a pair of drive rods whose distal ends are connected to each other at diagonal positions with respect to the imaging holder. Two drive force transmission mechanisms each including a drive device, a drive device disposed at a base end portion of the drive rod, and driving at least one drive rod in each drive force transmission mechanism forward and backward, and a base of the drive device A support shaft extending from the member side toward the imaging unit, a relay holder attached to the support shaft and supporting an intermediate portion of the driving rod, the imaging unit, the imaging holder, and the drive And a cover member that covers at least a part of the force transmission mechanism, the support shaft, and the relay holder, and the surfaces of the imaging holder and the relay holder A plurality of recessed portions formed and a plurality of U-shaped portions formed on the driving rod are fitted, and the imaging unit rotates around two different axes by the forward and backward driving of the driving rod. Features.

  As described above, according to the present invention, the image pickup unit is rotated about two axes without requiring a large space, thereby increasing the size of the apparatus (that is, increasing the diameter of the cover portion forming the insertion portion). It is possible to change the viewing direction during imaging in a wider range without inviting, and by using an elastic member, it is possible to reduce the number of drive rods that are driven forward and backward for the rotation operation of the imaging unit. Excellent effect. In addition, it is possible to easily assemble with a simple configuration that matches the concave portion of each holder and the U-shaped portion of the rod, and it is possible to reliably perform drive transmission.

Side view of endoscope 1 according to an embodiment The exploded perspective view of the outer shell of insertion part 3 concerning an embodiment Sectional drawing of endoscope 1 concerning an embodiment The principal part perspective view inside the insertion part 3 which concerns on embodiment Exploded perspective view around the imaging unit 12 according to the embodiment Exploded perspective view of driving force transmission mechanism 21 according to the embodiment Exploded perspective view and assembled perspective view of first and second drive rods 22 and 23 and imaging holder 11 and relay holder 42 according to the embodiment. Assembly perspective view showing assembly order of first and second drive rods 22, 23, imaging holder 11, relay holder 42 according to the embodiment Enlarged perspective view and cross-sectional view of an anti-rotation portion according to an embodiment The perspective view of the drive device 51 built in the main-body part 2 which concerns on embodiment The principal part side view which shows operation | movement of the driving force transmission mechanism 21 which concerns on embodiment. The schematic diagram which shows the operation | movement method of the driving force transmission mechanism 21 which concerns on embodiment Explanatory drawing which shows the folding method of the flexible cable 16 which connects the solid-state image sensor 14 and its drive board 17 which concern on embodiment. The schematic diagram which shows the positional relationship of the drive board | substrate 17 of the solid-state image sensor 14 which concerns on embodiment, and the 1st and 2nd rods 22 and 23 for a drive. The block diagram which shows the structure of the control system of the drive device 51 which concerns on embodiment. Timing chart showing an example of the operation of the driving device 51 according to the embodiment

  According to a first aspect of the present invention, there is provided an image pickup unit for picking up a subject image, an image pickup holder for holding the image pickup unit, and a pair of driving devices whose front ends are connected to diagonal positions relative to the image pickup holder. Two drive force transmission mechanisms each including a rod; a drive device disposed at a base end portion of the drive rod for driving forward and backward of at least one drive rod in each of the drive force transmission mechanisms; and A support shaft extending from the base member side toward the imaging unit, a relay holder attached to the support shaft and supporting an intermediate portion of the driving rod, the imaging unit, the imaging holder, A driving force transmission mechanism, a cover member that covers at least a part of the support shaft and the relay holder, and the imaging holder and the relay ho A plurality of concave portions formed on the surface of the slider and a plurality of U-shaped portions formed on the driving rod are fitted, and the imaging unit rotates around two different axes by the forward and backward driving of the driving rod. It is characterized by moving.

  According to the first aspect of the present invention, by changing the imaging unit around the two axes without requiring a large space, the viewing direction can be changed more widely during imaging without increasing the size of the apparatus. In addition to being able to be implemented in a range, by using an elastic member, it is possible to reduce the number of drive rods that are driven forward and backward for the rotational movement of the imaging unit. Moreover, since the structure of the apparatus is simplified by using a U-shaped portion for the drive rod, assembly is facilitated.

  According to a second aspect of the present invention, the driving rod is provided with a midway portion having a non-linear portion, and provided with a detent member that sandwiches the midway portion and restricts the rotation of the drive rod. Features.

  According to the second aspect of the present invention, the drive rod does not rotate freely with a non-rotating mechanism so that the U-shaped portion of the drive rod is not easily detached from the recesses of the imaging holder and the relay holder. be able to.

  According to a third aspect of the present invention, the detent rotates about the support shaft.

  According to the third aspect of the present invention, since the rotation stopper can freely rotate around the support shaft, it can be easily positioned when the drive rod is attached to the rotation stopper, and the drive rod can be easily attached.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view of an endoscope 1 according to the embodiment, and FIG. 2 is an exploded perspective view of an outer shell of the insertion portion 3 according to the embodiment.

  The endoscope 1 is a rigid endoscope used for medical use and industrial use, and mainly includes a main body portion 2 and an insertion portion 3 extending forward from the main body portion 2. The insertion portion 3 has a small diameter (for example, an outer diameter of 8 mm) and high rigidity that does not easily bend, and is inserted into a subject (for example, a patient's body) (not shown).

  The outer shell (cover member) of the insertion portion 3 defines a sealed internal space, and the metal protective tube 4 whose rear end (base end) side is fixed to the main body 2 and the front end of the protective tube 4 A cylindrical resin-made or glass-made intermediate cover 5 connected to the (tip) and a glass-made tip cover 6 connected to the front end of the intermediate cover 5 are configured. The front end cover 6 functions as an imaging window that transmits light. As shown in FIG. 2, the front end cover 6 is connected to the front end portion of the intermediate cover 5 and the front end side of the cylindrical portion 6a. It has a hemispherical tip convex portion 6b.

  FIG. 3 is a cross-sectional view of the endoscope 1 according to the embodiment, FIG. 4 is a perspective view of an essential part inside the insertion portion 3 according to the embodiment, and FIG. 5 is an imaging unit 12 according to the embodiment. FIG. 6 is an exploded perspective view of the periphery, and FIG. 6 is an exploded perspective view of the driving force transmission mechanism 21 according to the embodiment.

  As shown in FIGS. 3 and 4, the front end of the internal space of the insertion portion 3 is held by the imaging holder 11 so as to be rotatable about two axes (X axis and Y axis shown in FIG. 4). Thus, the imaging unit 12 that captures the subject image while changing the viewing direction is installed. The imaging unit 12 includes an objective lens system 13 composed of one or a plurality of optical lenses, and a solid-state imaging device 14 that is disposed at the rear part of the objective lens system 13 and forms an image of light from the lens on a light receiving surface. Here, it has a viewing angle of about 170 °. Note that, in the following, for the components related to the rotational movement around the two axes (X axis and Y axis) of the imaging unit 12, a suffix (X or Y) is added to the name or symbol of the component when distinguishing from each other. Shall be described. Here, in the solid-state imaging device 14, the main scanning direction and the sub scanning direction correspond to the X axis and the Y axis, respectively.

  As shown in FIG. 5, the imaging holder 11 has a cylindrical main body into which the rear portion of the objective lens system 13 is inserted, and a solid-state imaging device 14 is attached to the rear side of the main body. As the solid-state imaging device 14, a well-known image sensor composed of a CMOS (Complementary Metal Oxide Semiconductor) or the like can be used.

  The rear surface side of the solid-state imaging device 14 is joined and directly supported by the joint 15 of the flexible cable 16 by BGA (Ball Grid Array) connection. This joint 15 is used for transmitting and receiving various signals and supplying power. It is connected to a drive substrate 17 (see FIG. 3) via a flat flexible cable 16. The drive board 17 is provided with a voltage conversion circuit for a power source for driving the solid-state imaging device 14, a clock generation circuit, and the like. If the solid-state imaging device 14 is of a type that does not include an AD converter, the AD converter may be mounted on the drive substrate 17. The drive board 17 is positioned between the imaging unit 12 in the front-rear direction and a relay holder 42 described later, and is fixed to the inner peripheral surface of the intermediate cover 5. A cable (not shown) for transmitting and receiving captured image data and the like is disposed between the drive substrate 17 and the image processing apparatus (not shown) on the main body 2 side.

  Further, in the internal space of the insertion portion 3, two systems of driving force transmission mechanisms 21X and 21Y (see FIG. 4) respectively provided for the biaxial rotation operation of the imaging unit 12 are installed. These two systems of driving force transmission mechanisms 21X and 21Y have the same configuration, and each includes a pair of first extending in the front-rear direction with the front ends connected to the imaging holder 11 at diagonal positions. A first driving rod 22 and a second driving rod 23 are provided.

  The first and second drive rods 22 and 23 are made of a rod-shaped member made of so-called spring steel that can be bent, and as shown in FIG. 6, a front end portion 22a formed by bending a wire rod into a U-shape. , 23a. As shown in FIG. 4, a ring member 26 made of spring steel is attached to the outer periphery of the main body of the imaging holder 11 so as to press the U-shaped portions of the front end portions 22a and 23a. The U-shaped portions formed on the first and second drive rods 22 and 23 are not limited to the U-shape, and may be V-shaped.

  Here, as shown in FIG. 5, four ribs 31 and 32 are formed on the outer periphery of the main body of the imaging holder 11 so as to be approximately evenly arranged in the circumferential direction, and between the ribs 31 and 32. Four recesses 33 that define the positions of the front end portions 22a and 23a of the first and second drive rods 22 and 23 are formed. A groove 31a extending in the circumferential direction is formed in an intermediate portion of each rib 31 in the front-rear direction, and the ring member 26 is fitted in the groove. As shown in FIG. 5, the ring member 26 is formed of a circular metal ring having one cut portion 26a, and is attached to the groove 31a of each rib 31 by being temporarily deformed. The rib 32 does not have a groove extending in the circumferential direction, and the end of the ring member 26 abuts against the wall of the rib 32 so that the ring member 26 does not move freely in the circumferential direction.

  Then, the U-shaped portions of the front end portions 22a and 23a (two each as shown in FIG. 6) are positioned with an appropriate jig, fitted into the concave portion 33 of the imaging holder 11, and previously the ring member 26. The both ends of the cutting portion 26a are separated from each other, and the U-shaped portions of the front end portions 22a and 23a are engaged. Accordingly, when the first and second drive rods 22 and 23 are moved forward and backward, the imaging holder 11 is engaged so as to be displaceable accordingly.

  Further, in each driving force transmission mechanism 21, a hook end of the first driving rod 22 is connected to a metal motor connecting rod 24 extending in the front-rear direction shown in FIG. ing. The motor connecting rod 24 is movably inserted into a guide hole of a cylindrical guide member 35 fixedly supported by a support shaft 41 described later, and the rear end 24b reaches the main body 2 as shown in FIG. ing.

  Further, a front end portion 25a of a tension spring (elastic member) 25 extending in the front-rear direction is connected to a rear end portion 23b forming a hook shape of the second drive rod 23. The rear end portion 25 b of the tension spring 25 is fixed to the front surface of the guide member 35. The second drive rod 23 is held by a rotation stopper 49 that is freely attached to a support shaft 41 (described later) (details will be described later).

  Furthermore, as shown in FIG. 3, each driving force transmission mechanism 21 has a proximal end fixed to the main body 2 and extends in the front-rear direction along the central axis of the insertion portion 3 from the main body 2 side. A support shaft 41 is provided. A hemispherical relay holder 42 that supports the first and second drive rods 22 and 23 is attached to the tip of the support shaft 41. A guide member 35 is fixed to an intermediate portion of the support shaft 41.

  More specifically, as shown in FIG. 6, a spherical ball member 43 is attached to the distal end portion 41 a of the support shaft 41, and the ball member 43 has a spherical shape provided in the rear portion or inside of the relay holder 42. A ball joint is configured by being slidably received in a receiving portion (not shown) having a sliding surface. Via this ball joint, the relay holder 42 is tiltably held at the tip of the support shaft 41. The maximum outer diameter of the relay holder 42 is set to be smaller than the inner diameter of the outer shell of the insertion portion 3 (here, the intermediate cover 5 shown in FIG. 2), and the relay holder 42 is inserted when tilted. The structure is such that it does not contact the outer shell of the part 3.

  The first and second drive rods 22 and 23 have intermediate portions 22c and 23c formed in a U shape like the front end portions 22a and 23a described above, and the U shapes of these intermediate portions 22c and 23c. The portion is fixed to the relay holder 42 so as to be pressed by a ring member 45 attached to the outer periphery of the main body of the relay holder 42. The ring member 45 is formed of a circular spring steel ring having one cut portion 45a in the same manner as the ring member 26 described above, and is attached to a groove 47a of each rib 47 described later by being temporarily deformed.

  Here, on the outer periphery of the main body of the relay holder 42, similarly to the above-described imaging holder 11, four ribs 47 and 48 that are equally arranged in the circumferential direction are formed, and between the ribs 47 and 48. The four concave portions 46 that define the positions of the intermediate portions 22c and 23c of the first and second drive rods 22 and 23 are formed. A groove 47a extending in the circumferential direction is formed in an intermediate portion in the front-rear direction of each rib 47, and a ring member 45 is fitted in the groove. As shown in FIG. 6, the ring member 45 is formed of a circular metal ring having one cut portion 45 a and is attached to the groove 47 a of each rib 47 by being temporarily deformed. The rib 48 has no groove extending in the circumferential direction, and the end of the ring member 45 abuts against the wall of the rib 48 so that the ring member 45 does not move freely in the circumferential direction.

  Then, the U-shaped portions of the intermediate portions 22c and 23c (two each as shown in FIG. 6) are positioned with an appropriate jig, fitted into the concave portion 46 of the relay holder 42, and the ring member 45 in advance. The both ends of the cutting part 45a are separated from each other, and the U-shaped parts of the intermediate parts 22c and 23c are engaged. Thus, when the first and second drive rods 22 and 23 are moved forward and backward, the relay holder 42 is engaged so as to be tiltable accordingly. That is, a driving force for tilting the imaging holder 11 and the relay holder 42 can be reliably transmitted from the driving device 51 described later via the first and second driving rods 22 and 23.

  As described above, the intermediate portions 22c and 23c of the first and second drive rods 22 and 23 are connected to the relay holder 42, so that the relay mechanism 42 and the imaging holder 11 are linked as a first link mechanism. In addition, the second drive rods 22 and 23 can be made to function, and the imaging unit 12 can be stably rotated around two axes (X and Y axes shown in FIG. 4) in a small space.

  When the imaging unit 12 is rotated by the driving force transmission mechanism 21X, the rotation axis (X axis shown in FIG. 4) is a first and second pair that forms a pair in the driving force transmission mechanism 21Y (other system). It substantially coincides with an axis passing through the front end portions 22a, 23a of the drive rods 22, 23. Similarly, in the rotation of the imaging unit 12 by the driving force transmission mechanism 21Y, the rotation axis (Y axis shown in FIG. 4) is a pair of the first and second driving rods 22 in the driving force transmission mechanism 21X. 23 substantially coincides with an axis passing through the front end portions 22a and 23a. Therefore, the X axis and the Y axis are not fixed to the positional relationship shown in FIG. 4, and the displacement of the first and second driving rods 22, 23, etc. is performed in the rotation operation of the imaging unit 12. (With or deformation). In addition, by making the X axis and the Y axis orthogonal to each other, it is possible to easily realize the pan / tilt function at the time of imaging. However, these two axes do not necessarily need to be orthogonal, and simply intersect without being orthogonal. In some cases, they may be arranged at twisted positions.

  The fitting of the first and second drive rods 22 and 23 with the imaging holder 11 and the relay holder 42 will be described in more detail with reference to FIGS. 7 and 8. FIG. 7 is an exploded perspective view and an assembled perspective view of the first and second drive rods 22 and 23, the imaging holder 11, and the relay holder 42 according to the embodiment. FIG. 8 is an assembly perspective view showing the assembly order of the first and second drive rods 22 and 23, the imaging holder 11, and the relay holder 42 according to the embodiment.

  As shown in FIG. 7, the U-shaped portions 22a, 22c, 23a, and 23c of the first and second drive rods 22 and 23 are matched with the recesses 33 and 46 formed in the imaging holder 11 and the relay holder 42. Match. Since only the concave portion and the U-shaped portion are aligned, it can be smoothly and easily matched. Then, the cut portions of the ring members 26 and 45 are expanded, and the ring members 26 and 45 are moved in the direction of the central axis so as to be pushed over the first and second drive rods 22 and 23.

  Moreover, the assembly order mentioned above is demonstrated using FIG. First, using a jig (not shown), the U-shaped portions of the first and second drive rods 22 and 23 are aligned with the recesses of the relay holder 42 to collect four rods (1). Next, the ring member 45 is attached to the U-shaped portion of the rod matched with the relay holder 42 (2). Next, the integrated assembly of the imaging holder 11 and the drive board 17 assembled in advance is attached to the assembly completed in (2) (3). Finally, the ring member 26 is attached to the U-shaped portion of the rod matched with the imaging holder 11 (4).

  In this way, since the concave portion of the holder and the U-shaped portion of the rod are aligned and the ring member is attached, it can be assembled smoothly and easily. That is, it is possible to easily assemble with a simple configuration that matches the concave portion of each holder and the U-shaped portion of the rod, and it is possible to reliably perform drive transmission.

  Next, the above-described detent 49 will be described with reference to FIG. FIG. 9 is an enlarged perspective view and a cross-sectional view of the rotation stopper according to the embodiment.

  As shown in FIG. 9, the rotation stopper 49 is held by the support shaft 41 and is configured to rotate in the circumferential direction around the axis of the support shaft 41. Further, the rotation stopper 49 is formed with a groove 49a that sandwiches the second drive rod 23. The middle portion 23d (see FIG. 6) of the second drive rod 23 is sandwiched in the groove 49a, and the rear end portion 23b (see FIG. 6) of the second drive rod 23 is connected to the tension spring 25. The second drive rod 23 is provided with a non-linear portion, that is, a midway portion 23d having a stepped shape by bending or the like, and this is sandwiched by the inner wall surface of the rotation stopper 49 in the groove 49a, so that the second drive rod 23 The rotation due to the twist of the rod 23 or the like is restricted.

  As a result, the second drive rod 23 can be easily hung on the tension spring 25, and the second drive rod 23 itself can be prevented from rotating due to its end being connected to the tension spring 25. The U-shaped portion of the second drive rod 23 can be prevented from being detached from the recesses of the imaging holder 11 and the relay holder 42. In addition, although the step shape is given as an example of the shape of the middle part 23d of the second drive rod 23, the present invention is not limited to this, and the middle part is not limited thereto, as long as it is sandwiched facing the inner wall surface of the rotation stopper 49 The deformation of 23d is possible.

  FIG. 10 is a perspective view of the drive device 51 built in the main body 2 according to the embodiment. As also shown in FIG. 3, the main body 2 of the endoscope 1 includes a driving device 51 for driving the first and second driving rods 22 and 23 in the driving force transmission mechanism 21 to advance and retreat. Has been. In the drive device 51, a flange 54 a of a fixing member 54 to which the rear end of the insertion portion 3 (protective tube 4) is connected is attached to a base member 53 that forms the front side of the housing 52. In addition, in the housing 52, two electric motors 55X and 55Y that respectively generate driving forces applied to the driving force transmission mechanisms 21X and 21Y are provided.

  The electric motors 55X and 55Y are composed of a direct-acting stepping motor having a motor shaft (screw shaft) (not shown) that converts rotational motion into linear motion. This stepping motor is driven by so-called microstep driving. The rear end portion 24b of the motor connecting rod 24 in each driving force transmission mechanism 21 is disposed adjacent to the motor shafts of the electric motors 55X and 55Y extending in the front-rear direction, and is connected to the motor shaft via a connecting member 56. Has been. With such a configuration, the first and second drive rods 22 and 23 in each drive force transmission mechanism 21 are inserted in accordance with the amount of rotation of the electric motors 55X and 55Y (that is, the amount of movement of the motor shaft). 3 can move forward and backward substantially linearly in the axial direction (front-rear direction).

  Further, the drive device 51 is provided with two origin sensors 61X and 61Y for detecting the origin position of the motor shafts of the electric motors 55X and 55Y (that is, the motor connecting rod 24). Each of the origin sensors 61X and 61Y is composed of a PI (Photo interrupter) sensor having a light emitting unit 61a and a light receiving unit 61b arranged to face each other. In addition, each connecting member 56 is provided with a protruding projecting piece 56a that blocks light from the light emitting portion 61a. With such a configuration, when the motor shaft to which the connecting member 56 is attached moves, the shutter piece 56a is inserted between the light emitting part 61a and the light receiving part 61b, and the light from the light emitting part 61a is completely blocked. This position can be recognized as the origin position of the motor shaft.

  In addition, an illumination device 71 for imaging is built in the main body 2 shown in FIG. The lighting device 71 includes a plurality of LEDs (Light Emitting Diodes) 72 and a transparent resin light guide 74 that is disposed in front of the LEDs 72 and guides the light output from the LEDs 72 to the four optical fiber cables 73. Have. The LED 72 can selectively output one of white light, ultraviolet light, and infrared light according to the purpose of imaging, or can simultaneously output them. As shown in FIG. 6, the optical fiber cable 73 is extended to the vicinity of the imaging unit 12 (see FIG. 3) through the inside of the insertion portion 3. is there.

  FIG. 11 is a main part side view showing the operation of the driving force transmission mechanism 21 according to the embodiment, and FIG. 12 is a schematic diagram showing the operation method of the driving force transmission mechanism 21 according to the embodiment.

  As shown in FIG. 11A, in the endoscope 1 in the initial state, the visual field direction of the imaging unit 12 is directed forward along the central axis C1 of the insertion portion. At this time, as shown in FIG. 12A, a backward force (spring urging force) by the tension spring 25 acts on the rear end portion 23b of the second drive rod 23, and the relay holder 42 A predetermined tension is generated between the intermediate portion 23 c and the rear end portion 23 b of the second drive rod 23 supported by the ring member 45. On the other hand, the tension applied by the tension spring 25 is transmitted to the intermediate portion 22 c via the relay holder 42, whereby the intermediate portion 22 c of the first drive rod 22 supported by the ring member 45 of the relay holder 42. Tension is also generated between (see FIG. 6) and the rear end portion 22b (see FIG. 6).

  Next, when changing the visual field direction of the endoscope 1, for example, the electric motor 55 </ b> X illustrated in FIG. 3 is operated to retract the motor connecting rod 24. Thus, as shown in FIG. 11B, the imaging unit 12 rotates around the X axis, and the viewing direction is changed. Here, as shown in FIG. 4, the outer peripheral surface of the rib 31 of the imaging holder 11 has the same curvature as the inner peripheral surface of the tip convex portion 6 b (see FIG. 2) of the tip cover 6. When the imaging unit 12 is rotated, the outer peripheral surface of the rib 31 is slidably contacted with the inner peripheral surface of the tip convex portion 6b to guide the rotational operation. Here, an example in which the inclination angle θ of the central axis C2 of the imaging unit 12 with respect to the central axis C1 of the insertion unit is 30 ° is shown, but this inclination angle θ is within a predetermined range (for example, 0 ° ≦ θ ≦ 35 °) can be arbitrarily set.

  At this time, as shown in FIG. 12 (B), the rear end portion 22b of the first drive rod 22 receives a backward force via the motor connecting rod 24 (the driving force of the electric motor 55X shown in FIG. 3). ) Acts. As a result, the relay holder 42 tilts and the front end portion 22a of the first drive rod 22 moves backward, and the front end portion 23a of the second drive rod 23 moves forward. As a result, a driving force acts on the ring member 26 of the imaging holder 11 and the imaging unit 12 rotates around the X axis against the urging force of the tension spring 25. Also in such an operation of changing the viewing direction, as in FIG. 11A, the intermediate portion 23c and the rear end portion 23b of the second drive rod 23 and the intermediate portion of the first drive rod 22 are provided. A predetermined tension is generated between 22c and the rear end 22b.

  With such a configuration, it is possible to always apply tension to the first and second drive rods 22 and 23, thereby preventing a force in the buckling direction from acting on them, and the drive force transmission mechanism 21. Increased reliability. In addition, the tilting operation of the relay holder 42 can be performed smoothly.

  Here, an example of operation in which the motor connecting rod 24 is moved backward has been shown, but the motor connecting rod 24 can also be moved forward. Even in this case, the tension similar to that described above acts on the first and second drive rods 22 and 23 by the tension spring 25. Although only the movement around the X axis is shown here, the movement around the Y axis is also possible. Furthermore, by simultaneously or sequentially operating the electric motors 55X and 55Y, it can be rotated around two axes. For example, the drive speed of each electric motor 55X and 55Y is changed to a sine wave and the phase of both is controlled. Thus, it is possible to move the center of the imaging range on an arc or draw a so-called Lissajous figure.

  FIG. 13 is an explanatory view showing a folding method of the flexible cable 16 for connecting the solid-state image sensor 14 and its drive board 17 according to the embodiment. FIG. 13 (A) shows the connection between the solid-state image sensor 14 and its drive board 17. It is explanatory drawing which shows the folding method of the flexible cable 16 to do. FIG. 13B is an explanatory view showing a state where the flexible cable 16 is folded.

  As described above, while the imaging unit 12 is rotatable, the drive substrate 17 is fixed in the intermediate cover 5 of the insertion portion 3, so that the flexible cable 16 that connects them rotates the imaging unit 12. In this case, it is desirable to easily deform in any direction without causing local concentration of stress. On the other hand, it is desirable to keep the length as short as possible from the viewpoint of attenuation and noise resistance of the clock signal output from the driving substrate 17 to the solid-state imaging device 14.

  Therefore, as shown in FIG. 13A, the flexible cable 16 folds the portions (indicated by the alternate long and short dash lines in FIG. 10A) arranged at predetermined intervals in the longitudinal direction, while adjacent folds. Bending a portion (shown by a broken line in FIG. 13A) arranged to connect one end and the other end of the portion into a valley fold, and processing into the shape shown in FIG. 13B Thus, in addition to the direction perpendicular to the drive substrate 17, the bending in the parallel direction can be easily performed. As a result, the flexible cable 16 that can be bent in an arbitrary direction can be formed as short as possible.

  In addition, if the flexible cable 16 is bent in the range of one cycle shown in FIG. 13A, it is possible to cope with the deformation in the biaxial direction at a minimum. Since the distance change (initial position error) between the imaging unit 12) and the fixed portion (drive substrate 17) can be expanded and contracted, the number of cycles is preferably 2 or more from the viewpoint of improving reliability.

  FIG. 14 is a schematic diagram showing a positional relationship between the driving substrate 17 and the first and second driving rods 22 and 23 of the solid-state imaging device 14 according to the embodiment. When the imaging unit 12 is rotated as shown in FIGS. 11 and 12, when viewed from the axial direction of the insertion portion 3, as the rotation angle increases, a two-dot chain line in FIG. As shown, the positions of the first and second drive rods 22 and 23 surrounding the drive substrate 17 can be displaced inward.

  Accordingly, as shown in FIG. 14, the drive board 17 is disposed in such a direction that the plate surface 17a does not intersect the axial direction of the insertion portion 3 (the direction perpendicular to the paper surface of FIG. 14), and the insertion portion is extended. The axis C3 in the longitudinal direction of the drive substrate 17 viewed from the direction may be arranged so as not to overlap the positions of the first and second drive rods 22 and 23. In FIG. 14, the drive substrate 17 is disposed so that the angle formed by the axis C <b> 3 and the X axis or the Y axis is 45 °. Thereby, it is possible to prevent interference with the installation space of the drive board 17 even when the interval between the first and second drive rods 22 and 23 is reduced during the rotation of the imaging unit 12.

  FIG. 15 is a block diagram illustrating a configuration of a control system of the driving device 51 according to the embodiment. An operation interface 81 provided in the drive device 51 includes a position input device 82 that is used for an operator to adjust the visual field direction, LED on / off, and the type of light to be emitted (white light, ultraviolet light). LED switch 83 for selecting light and infrared light. The position input device 82 can be composed of a joystick, a trackball, or the like.

  The drive control unit 84 includes motor controllers 85X and 85Y that control the electric motors 55X and 55Y (see FIG. 10), respectively. The motor controllers 85X and 85Y provide drive control signals for controlling the rotation direction and the rotation amount of the electric motors 55X and 55Y based on the position control signal including the position information input from the position input device 82, as motor drivers 86X and 86Y. Output for. The motor drivers 86X and 86Y drive the electric motors 55X and 55Y, respectively, based on the input drive control signal.

  The drive control unit 84 can recognize that the electric motors 55X and 55Y are at the origin position based on the origin position signals input from the origin sensors 61X and 61Y. The clock input from the pulse generator 87 is supplied to a CPU (Central Processing Unit) (not shown) in the drive control unit 84, and the timing of overall control is achieved, and as a reference clock for drive pulses of the electric motors 55X and 55Y, or It is used to set the timing of the analog output sample hold and flip-flop of the origin sensors 61X and 61Y. The electric power supplied from the constant current source 91 to the drive control unit 84 is input to the LED board 92 and used for lighting the LED 72. Further, a control voltage is input from the constant voltage source 93 to the drive control unit 84 and the motor drivers 86X and 86Y.

  FIG. 16 is a timing chart showing an example of the operation of the driving device 51 according to the embodiment. The control of each timing in FIG. 16 is executed by a CPU (not shown).

  First, when the power supply of the endoscope is turned on at time t1, the X origin sensor 61X is monitored by the CPU, and then the initialization operation of the motor X (electric motor 55X) is started at time t2. In this initialization operation, first, home detection is performed by moving the motor shaft in a predetermined direction (here, forward) until the X origin sensor 61X detects the origin position (time t3). Subsequently, after the motor shaft of the motor X is moved in the reverse direction, the initialization operation is completed by returning the motor shaft to the origin position again (time t4). Thereafter, as with the motor X, an initialization operation is performed for the motor Y (electric motor 55Y) at times t5 to t7.

  When the initialization operation of the motors X and Y is completed, imaging (acquisition of captured image data) by the imaging unit 12 is started, and the operator can operate the viewing direction of the endoscope using the operation interface. When an operation signal corresponding to the visual field direction change command from the operator is input at time t8 to t9, the motors X and Y execute a predetermined operation based on the operation signal. Captured image data (video signal output from the solid-state image sensor 14) obtained by imaging is sent to a signal processing device (not shown) connected to the main body, and subjected to predetermined image processing such as color correction and γ correction. After that, the captured image is displayed by being sent to a monitor or the like.

  As described above, the endoscope 1 includes the two systems of the driving force transmission mechanisms 21X and 21Y including the pair of first and second driving rods 22 and 23, respectively, so that an image can be taken without requiring a large space. The unit 12 can be rotated around two axes, and the viewing direction can be changed in a wider range without causing an increase in the size of the apparatus (that is, an increase in the diameter of the outer shell of the insertion portion 3). It is possible.

  In the endoscope 1, the intermediate portions 22 c and 23 c of the first and second drive rods 22 and 23 are supported by the relay holder 42 that is tiltably attached to the support shaft 41. In addition, the imaging unit 12 can be stably rotated around the two axes in a small space regardless of the lengths of the second drive rods 22 and 23.

  Further, a concave portion is formed in the imaging holder 11 and the relay holder 42, and U-shaped portions are formed in the first and second driving rods 22, 23, and the concave portions of the respective holders and the U-shaped portions of the rods are combined, By attaching the ring members 26 and 45, it is possible to assemble smoothly and easily and to perform drive transmission reliably.

  Further, since the endoscope 1 has a configuration in which the drive substrate 17 is disposed in the space between the imaging unit 12 and the relay holder, the drive substrate 17 can be disposed in the vicinity of the solid-state image sensor 14, It is possible to drive the imaging element 14 stably and improve the reliability of the imaging process.

  In the endoscope 1, the second driving rod 23 is not driven by the electric motors 55 </ b> X and 55 </ b> Y, and the rear end portion 23 b is on the base member 53 side (guide member 35) via the tension spring 25. Since they are connected, the number of driving rods (corresponding to the first driving rods 22) that are driven forward and backward for the rotation operation of the imaging unit 12 can be reduced. Further, the tension spring 25 can prevent rattling in the rotation operation of the imaging unit 12. Furthermore, there is an advantage that the influence of the urging force of the tension spring 25 on the imaging unit 12 can be eliminated by interposing the relay holder 42.

  Although the present invention has been described based on specific embodiments, these embodiments are merely examples, and the present invention is not limited to these embodiments. For example, in an endoscope used in an environment where it is not necessary to consider intrusion of liquid or the like into the insertion portion, the outer shell of the insertion portion does not necessarily define a sealed internal space. Or a structure that covers at least a part of the driving force transmission mechanism or the like.

  Further, the first driving rod and the motor connecting rod in the driving force transmission mechanism are integrally formed (for example, the motor connecting rod is omitted by extending the base end side of the first driving rod in the embodiment). )Is possible.

  In addition, when the endoscope is used for medical purposes, when the sterilization process or the like of the insertion portion is necessary, at least the insertion portion can be separated using a known adapter.

  Further, the driving force for rotating the imaging unit is not necessarily generated by the electric motor, and a known configuration in which the operator manually generates the driving force can be used.

  Moreover, the elastic member used for the driving force transmission mechanism is not limited to the tension spring, and other known members can be used. In some cases, a compression spring or the like that generates a force in the direction opposite to that of the tension spring may be used.

  Further, it is not always necessary to use an elastic member (tensile spring) for the driving force transmission mechanism, and a configuration in which all the driving rods are driven by an electric motor or the like is also possible. In this case, the paired drive rods may be driven in opposite directions and with the same displacement amount.

  Note that all the constituent elements of the endoscope according to the present invention shown in the above-described embodiment are not necessarily essential, and can be appropriately selected as long as they do not depart from the scope of the present invention.

  The endoscope according to the present invention can rotate the imaging unit around two axes without requiring a large space, and can change the visual field direction during imaging without increasing the size of the apparatus. In addition, the endoscope is useful as an endoscope that facilitates assembling of a mechanism that is advanced and retracted to rotate the imaging unit.

DESCRIPTION OF SYMBOLS 1 Endoscope 2 Main-body part 3 Insertion part 4 Protective tube 5 Intermediate cover 6 Tip cover 6b Tip convex part 11 Imaging holder 12 Imaging unit 13 Objective lens system 14 Solid-state image sensor 16 Flexible cable 17 Driving board 17a Plate surface 21 Driving force Transmission mechanism 22 First drive rod 22a Front end (U-shaped part)
22b Rear end (U-shaped part)
22c Middle part (U-shaped part)
23 Second drive rod 23a Front end (U-shaped part)
23b Rear end (U-shaped part)
23c Middle part (U-shaped part)
23d Midway part 25 Tension spring (elastic member)
31 Ribs 33, 46 Concave portion 41 Support shaft 42 Relay holder 49 Non-rotating 51 Drive device 53 Base member

Claims (3)

An imaging unit for capturing a subject image;
An imaging holder for holding the imaging unit;
Two systems of driving force transmission mechanisms each including a pair of driving rods whose distal ends are coupled to each other at diagonal positions with respect to the imaging holder;
A driving device that is disposed at a base end portion of the driving rod and that drives at least one driving rod in each of the driving force transmission mechanisms to advance and retreat;
A support shaft extending from the base member side of the driving device toward the imaging unit;
A relay holder attached to the support shaft and supporting an intermediate portion of the drive rod;
A cover member that covers at least a part of the imaging unit, the imaging holder, the driving force transmission mechanism, the support shaft, and the relay holder;
A plurality of concave portions formed on the surfaces of the imaging holder and the relay holder and a plurality of U-shaped portions formed on the driving rod are fitted,
The endoscope is characterized in that the imaging unit is rotated around two different axes by advancing and retracting driving rods.   2. The drive rod according to claim 1, further comprising an anti-rotation member that includes a midway portion having a non-linear portion in the drive rod and restricts the rotation of the drive rod by sandwiching the midway portion. Endoscope.   The endoscope according to claim 2, wherein the rotation preventing member rotates about the support shaft.

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