Patent Publication Number: US-2019175001-A1

Title: Endoscope

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of PCT/JP2017/031178 filed on Aug. 30, 2017 and claims benefit of Japanese Application No. 2016-207819 filed in Japan on Oct. 24, 2016, the entire contents of which are incorporated herein by this reference. 
    
    
     BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates to a variable direction-of-view endoscope, and in particular to an endoscope in which a direction of view is changed by moving an optical device provided on a distal end portion of an insertion portion. 
     2. Description of the Related Art 
     In order to observe a position where observation is difficult, such as an inside of a living body or an inside of a structure, endoscopes for picking up an optical image, which can be introduced into the inside of the living body or the structure from outside, are used, for example, in a medical field or an industrial field. 
     Among the endoscopes, there are endoscopes having a flexible insertion portion, which are used for examination and treatment of digestive tracts, and endoscopes having a rigid insertion portion, which are used for surgical operations. 
     Especially, the endoscopes having a rigid insertion portion is referred to as a rigid endoscope, a laparoscope, a pyeloscope and the like, and, for example, as disclosed in Japanese Patent Application Laid-Open Publication No. 07-327916, a variable direction-of-view endoscope is known in which a field of view (an oblique angle) can be freely changed by turning a prism of an optical device on a distal end to cause the prism to tilt. 
     SUMMARY OF THE INVENTION 
     An endoscope of one aspect of the present invention is provided with: a first frame body turnably provided around a shaft body, the first frame body holding an optical device; a second frame body turnably holding the first frame body; a recessedly formed groove portion, the groove portion being in contact with an outer circumferential face of the shaft body; and an elastic member configured to give a tensile load in a direction in which the shaft body and the groove portion are in contact. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an overall configuration of an endoscope of one aspect; 
         FIG. 2  is an exploded perspective view showing a configuration of a direction-of-view changing mechanism of the one aspect; 
         FIG. 3  is a perspective view showing the configuration of the direction-of-view changing mechanism of the one aspect; 
         FIG. 4  is a cross-sectional view showing a distal end portion of an insertion portion of the one aspect in which the direction-of-view changing mechanism is arranged; 
         FIG. 5  is a left side view showing the configuration of the direction-of-view changing mechanism of the one aspect; 
         FIG. 6  is an enlarged view showing a configuration of a turning shaft and an abutting portion of the one aspect; 
         FIG. 7  is a left side view showing a configuration of a direction-of-view changing mechanism of a first modification of the one aspect; 
         FIG. 8  is a left side view showing a configuration of a direction-of-view changing mechanism of a second modification of the one aspect; 
         FIG. 9  is a left side view showing a configuration of a direction-of-view changing mechanism of a third modification of the one aspect; 
         FIG. 10  is a left side view showing a configuration of a direction-of-view changing mechanism of a fourth modification of the one aspect; 
         FIG. 11  is a left side view showing a configuration of a direction-of-view changing mechanism of a fifth modification of the one aspect; and 
         FIG. 12  is a right side view showing a configuration of a direction-of-view changing mechanism according to a sixth modification of the one aspect. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
     A preferable embodiment of the present invention will be described below with reference to drawings. Note that, in each of drawings used in description below, a reduced scale is made different for each component so that the component is in a size recognizable on the drawing, and the present invention is not limited only to the number of components, shapes of the components, a size ratio among the components, and a relative positional relationship among the respective components illustrated on the drawings. Further, in the description below, there may be a case where description is made on an assumption that upward and downward directions relative to a figure correspond to upper and lower parts of a component, respectively. 
     First, an endoscope of one aspect of the present invention will be described below. 
       FIG. 1  is a perspective view showing an overall configuration of the endoscope;  FIG. 2  is an exploded perspective view showing a configuration of a direction-of-view changing mechanism;  FIG. 3  is a perspective view showing the configuration of the direction-of-view changing mechanism;  FIG. 4  is a cross-sectional view showing a distal end portion of an insertion portion in which the direction-of-view changing mechanism is arranged;  FIG. 5  is a left side view showing the configuration of the direction-of-view changing mechanism; and  FIG. 6  is an enlarged view showing a configuration of a turning shaft and an abutting portion. 
     As shown in  FIG. 1 , an endoscope  1  of the present embodiment is a medical apparatus that can be introduced into a subject such as a human body and that is, for example, for surgery or for examining urinary organs. The endoscope  1  has a configuration for optically picking up an image of a predetermined observation region in the subject. 
     Note that the subject into which the endoscope  1  is introduced is not limited to a human body but may be a different living body or may be an artifact such as a machine or a structure. 
     The endoscope  1  is mainly configured with a rigid insertion portion  2  to be introduced into an inside of a subject/object, an operation portion  3  located at a proximal end of the insertion portion  2  and a universal cord  4  extending from a proximal end portion of the operation portion  3 . 
     Note that the endoscope  1  here is an endoscope in a form referred to as a so-called rigid endoscope, a laparoscope, a pyeloscope or the like in which the insertion portion  2  is not provided with a part having flexibility. Of course, the configuration of the present embodiment is a technique applicable to a flexible endoscope such as an endoscope for upper endoscopy to be introduced from an oral cavity or an endoscope for lower endoscopy to be inserted from an anus. 
     The universal cord  4  is provided with an endoscope connector  4   a  to be connected to an external apparatus  5  such as a video processor, on a proximal end portion. 
     The external apparatus  5  is provided with an image processing portion. The image processing portion generates a video signal based on an image pickup device output signal outputted from an image pickup device not shown and outputs the video signal to an image displaying portion  6  which is a monitor. That is, in the present embodiment, an optical image (an endoscopic image) picked up by the image pickup device is displayed on the image displaying portion  6  as video. 
     Note that the image pickup device is a very small-sized electronic part, and a plurality of devices configured to output an electrical signal according to incident light at a predetermined timing are arrayed on a planar light receiving portion. For example, a form generally referred to as a CCD (charge-coupled device) sensor or a CMOS (complementary metal-oxide semiconductor) sensor, or other various forms are applied. The image pickup device is connected to a circuit board and the like not shown. 
     The insertion portion  2  of the endoscope  1  is provided with a dome-shaped cover glass  7  as an observation window on a lower part side of a distal end. On an upper part of a center of the operation portion  3  of the endoscope  1 , an operation lever  8 , which is an operation member of a so-called joystick type, is arranged, and a rubber boot  9 , which is a cover body covering a projecting root part of the operation lever  8 , is provided. 
     Next, a direction-of-view changing mechanism provided in the insertion portion  2  of the endoscope  1  will be described in detail below. 
     As shown in  FIGS. 2 and 3 , a direction-of-view changing mechanism  10  is configured mainly including a substantially cylindrical holding portion  11  as a second frame body, an optical device holding frame  12  as a first frame body, the optical device holding frame  12  being a recess-shaped rotating portion having an angularly U-shaped cross section, a prism  13  as an optical device held by the optical device holding frame  12 , two operation wires  16  and  17  which are pulling members inserted through tube bodies  14  and  15  such as coil tubes, respectively, and a tension spring  18  as an elastic member, which is a biasing member. 
     The holding portion  11  is formed with metal such as stainless steel or rigid resin and has a hole portion  21  along a longitudinal axis direction. On both side parts of the holding portion  11 , two arm portions  22  and  23  are provided extending toward a distal end side in a forward direction. 
     Moreover, on one side portion of the holding portion  11 , here, on a right side portion when the holding portion  11  is seen from the distal end side, a notch portion  24  along a side face of the arm portion  23  is formed. On the two arm portions  22  and  23 , abutting portions  25  and  26 , which are recessedly formed V-shaped grooves, from which corner portions on an upper part side here on the distal end side are cut, are formed. The two abutting portions  25  and  26  have two planar portions  25   a  and  25   b  and two planar portions  26   a  and  26   b,  respectively, the two planar portions forming a predetermined angle. 
     The optical device holding frame  12  fixes and holds the prism  13  by adhesion or the like. The optical device holding frame  12  is provided with turning shafts  31 , which are shaft bodies, substantially at centers of both side faces, respectively. The two turning shafts  31  are arranged on the abutting portions  25  and  26  formed on the two arm portions  22  and  23  of the holding portion  11 . 
     Consequently, the optical device holding frame  12  is installed in a manner of freely turning around the turning shafts  31  in a state of being sandwiched between the two arm portions  22  and  23 . 
     Note that the two turning shafts  31  may be inserted and fixed in hole portions formed on the side faces of the optical device holding frame  12  by crimping or the like or may be integrally cut and formed on the side faces of the optical device holding frame  12 . 
     Distal ends of the two operation wires  16  and  17  extended from the tube bodies  14  and  15 , respectively, are connected and fixed to upper and lower parts on a proximal end side of one side face of the optical device holding frame  12 , here on the left side face by solder, caulking or the like, inserted into the hole portion  21  of the holding portion and extended from the proximal end side. 
     Then, the two operation wires  16  and  17  are inserted into the insertion portion  2  of the endoscope  1  in a state of being covered with the tube bodies  14  and  15  and connected to the operation lever  8  provided on the operation portion  3 . Consequently, the two operation wires  16  and  17  are pulled or loosened by a forward or backward tilting operation of the operation lever  8  and move forward or backward. 
     The tension spring  18  is arranged on the notch portion  24  of the holding portion  11 , and a proximal end of a wire  32  is connected to a hook on one end on the distal end side. A hook on the other end on a proximal end side of the tension spring  18  is hooked on a projecting portion not shown, which is provided on the notch portion  24  of the holding portion  11 . 
     A distal end of the wire  32  is provided with a ring  33 . The ring  33  is fitted onto the turning shaft  31  extending from the side face of the arm portion  23  on a right side when seen from the distal end side. Note that, instead of providing the ring  33  on the distal end of the wire  32 , the distal end of the wire  32  may be formed in a ring shape to be hooked on the turning shaft  31 . 
     Thus, tension (a tensile load) F (see  FIG. 4 ) by a biasing force of the tension spring  18  is given to the turning shaft  31 , and the turning shaft  31  on the right side when seen from the distal end side is abutted by the abutting portion  26 . Furthermore, the turning shaft  31  on the left side when seen from the distal end side is abutted by the abutting portion  26  by tension which is tension (a tensile load) on the rear (proximal end) side by the two operation wires  16  and  17 . 
     That is, the two turning shafts  31  of the optical device holding frame  12  are in a state of being pulled to a proximal-end lower side here so as to come into contact with the two planar portions  25   a  and  25   b  and the two planar portions  26   a  and  26   b  formed on the abutting portions  25  and  26  of the two arm portions  22  and  23 , respectively. Consequently, the optical device holding frame  12  is turnably arranged between the two arm portions  22  and  23  in a stable state. 
     As shown in  FIG. 4 , the direction-of-view changing mechanism  10  configured as described above is arranged in a distal end portion of the insertion portion  2  of the endoscope  1 . Note that the insertion portion  2  of the endoscope  1  has an exterior tube  19  which is an insertion pipe with a distal end lower part side sealed with the cover glass  7 . 
     In the direction-of-view changing mechanism  10 , when the upper operation wire  16  is pulled, and the lower operation wire  17  is loosened by an operation of the operation lever  8 , the optical device holding frame  12  turns clockwise (a direction of an arrow U) around the turning shafts  31  relative to  FIG. 4 . Consequently, a light refraction direction of the prism  13  held by the optical device holding frame  12  changes, and the direction of view of the endoscope  1  is changed to an upper side. 
     On the other hand, when the lower operation wire  17  is pulled, and the upper operation wire  16  is loosened by an operation of the operation lever  8 , the optical device holding frame  12  of the direction-of-view changing mechanism  10  turns counterclockwise (a direction of an arrow D) around the turning shafts  31  relative to  FIG. 4 . Consequently, the light refraction direction of the prism  13  held by the optical device holding frame  12  changes, and the direction of view of the endoscope 
     As described above, in the endoscope  1  of the present embodiment, a state in which outer circumferential faces of the turning shafts  31  of the optical device holding frame  12  holding the prism  13  which is an optical device are in contact with two positions on the two planar portions  25   a  and  25   b  and two positions on the two planar portions  26   a  and  26   b  of the abutting portions  25  and  26  formed as V-shaped grooves, which are formed on the arm portions  22  and  23  of the holding portion  11 , respectively, is continuously maintained by the tension (the tensile load) F on the proximal-end lower side by the biasing force of the tension spring  18  and the tension on the rear (proximal end) side by the two operation wires  16  and  17 . 
     Consequently, the endoscope  1  is configured such that backlash of the optical device holding frame  12  that turns, holding the prism  13  which is an optical device does not occur, and highly accurate positioning of the prism  13  is easily performed. 
     Moreover, at the time of assembling the direction-of-view changing mechanism  10 , the optical device holding frame  12  is easily positioned at a predetermined position only by adding a biasing force by the tension spring  18  and tension of the two operation wires  16  and  17  so that the outer circumferential faces of the turning shafts  31  are abutted by the two planar portions  25   a  and  25   b  and the two planar portions  26   a  and  26   b  of the abutting portions  25  and  26 , respectively, after installing the turning shafts  31  of the optical device holding frame  12  on the abutting portions  25  and  26  formed as V-shaped grooves. Therefore, assembly workability is improved. 
     Note that, as shown in  FIG. 5 , an angle θ formed by the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) of the abutting portion  26  ( 25 ) is only required to be 180° or smaller, and the angle is shown as substantially 90° here (in  FIG. 5 , the two planar portions  26   a  and  26   b  of the abutting portion  26  of the right side face are shown). 
     As shown in  FIG. 6 , a direction of the tension (the tensile load) F by the tension spring  18  is only required to be included in an area a between imaginary lines X and Y that pass points of contact A and B at which the left (right) turning shaft  31  is in contact with the two planar portions  25   a  and  25   b  ( 26   a  and  26   b ) of the abutting portion  25  ( 26 ) from a center O of the turning shaft  31 , and such a direction that the area a is equally divided into two is desirable. 
     MODIFICATIONS 
     Note that configurations of other aspects having operation and effects similar to the operation and effects of the endoscope  1  of the embodiment described above will be illustrated in various modifications below. In the configuration of the above embodiment and the configurations of the various modifications below, main portions of the embodiment and the modifications can be combined. 
     First Modification 
       FIG. 7  is a right side view showing a configuration of a direction-of-view changing mechanism according to a first modification. 
     As shown in  FIG. 7 , a configuration is also possible in which the abutting portion  26  ( 25 ) configured with the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) are formed as a V-shaped groove recessedly formed on the distal end face of the arm portion  22  ( 23 ), and the tension spring  18  is arranged so that a biasing force is given toward the proximal end side in a backward direction, and the tension (the tensile load) F is applied to the turning shaft  31  on the right toward the proximal end side (in  FIG. 7 , the two planar portions  26   a  and  26   b  of the abutting portion  26  on the right side face are shown). 
     Second Modification 
       FIG. 8  is a right side view showing a configuration of a direction-of-view changing mechanism according to a second modification. 
     As shown in  FIG. 8 , a configuration is also possible in which the abutting portion  26  ( 25 ) is formed as a curved face  26   c  ( 25   c ) on the distal end face of the arm portion  22  ( 23 ) to be in an arc groove shape recessedly formed in an R shape substantially same as the outer circumferential faces of the turning shafts  31 , and the tension spring  18  is arranged so that a biasing force is given to the proximal end side in the backward direction, and the tension (the tensile load) F is applied to the turning shaft  31  on the right toward the proximal end side (in  FIG. 8 , only the curved face  26   c  of the abutting portion  26  on the right side face is shown). 
     Third Modification 
       FIG. 9  is a right side view showing a configuration of a direction-of-view changing mechanism according to a third modification. 
     As shown in  FIG. 9 , a configuration is also possible in which, instead of providing the turning shafts  31 , a proximal end of the optical device holding frame  12  is formed as an arc-shaped curved face  34 , and the curved face  34  is abutted by the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) of the abutting portion  26  ( 25 ) that is recessedly formed as a V-shape groove on the distal end face of the arm portion  22  ( 23 ) (in  FIG. 9 , the two planar portions  26   a  and  26   b  of the abutting portion  26  on the right side face are shown). 
     Note that, here, a projecting portion  35  configured for the ring  33  to be hooked is provided on a proximal end part of the optical device holding frame  12 , and the tension spring  18  is arranged so that a biasing force is given to the proximal end side in the backward direction, and the tension (the tensile load) F is applied to the optical device holding frame  12  toward the proximal end side. 
     Fourth Modification 
       FIG. 10  is a right side view showing a configuration of a direction-of-view changing mechanism according to a fourth modification. 
     As shown in  FIG. 10 , a torsion spring  41 , which is a biasing member configured to bias the turning shafts  31  counterclockwise here and generate rotation torque T to bias the optical device holding frame  12  counterclockwise around the turning shafts  31  here to change the direction of view downward, may be provided, and only the operation wire  16  to perform a pulling operation of the optical device holding frame  12  clockwise around the turning shafts  31  here to change the direction of view upward may be provided (in  FIG. 10 , the two planar portions  26   a  and  26   b  of the abutting portion  26  on the right side face are shown). 
     Note that the torsion spring  41  is fitted to a spring support shaft  42  provided on the arm portion  23 , and both ends are in contact with projecting portions  43  and  44  provided on the holding portion  11  and the optical device holding frame  12 . 
     That is, here, by the operation wire  16  being pulled, tension N of the operation wire  16  exceeds the rotational torque T of the torsion spring  41 , and the optical device holding frame  12  turns clockwise around the turning shafts  31 . Then, by the operation wire  16  being loosened, the rotational torque T of the torsion spring  41  exceeds the tension N of the operation wire  16 , and the optical device holding frame  12  turns counterclockwise around the turning shafts  31 . 
     According to such a configuration, it is possible to turn the optical device holding frame  12  only by a pulling/loosening operation of the one operation wire  16  and change the direction of view of the endoscope  1  upward or downward. 
     Note that even though a direction of resultant force of the tension N of the operation wire  16  applied to the turning shaft  31  on the left and the rotational torque T of the torsion spring  41  is away from (floats from) the abutting portion  26  ( 25 ), the turning shaft  31  on the right (left) can be stably abutted by the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) of the abutting portion  26  ( 25 ) by the tension (the tensile load) F by the tension spring  18 . 
     Fifth Modification 
       FIG. 11  is a right side view showing a configuration of a direction-of-view changing mechanism according to a fifth modification. 
     As shown in  FIG. 11 , here, a projecting portion  45  configured so that the ring  33  is hooked is provided on a distal end lower part of the optical device holding frame  12 , and the tension spring  18  is arranged so that a biasing force is given to the proximal end lower side, and the tension (the tensile load) F is applied to the optical device holding frame  12  toward the proximal end lower side. 
     Moreover, here, the tension N by the operation wire  16  is also set to be applied to the optical device holding frame  12  toward the proximal end lower side. 
     That is, here, by the operation wire  16  being pulled, the tension N of the operation wire  16  exceeds the tension (the tensile load) F of the tension spring  18 , and the optical device holding frame  12  turns clockwise around the turning shafts  31 . Then, by the operation wire  16  being loosened, the tension (the tensile load) F of the tension spring  18  exceeds the tension N of the operation wire  16 , and the optical device holding frame  12  turns counterclockwise around the turning shafts  31 . 
     Even if such a configuration is adopted, it is also possible to turn the optical device holding frame  12  only by a pulling/loosening operation of the one operation wire  16  and change the direction of view of the endoscope  1  upward or downward. 
     Note that it is necessary that the resultant force of the tension N of the operation wire  16  applied to the turning shaft  31  on the left and the tension (the tensile load) F of the tension spring  18  continuously works in the direction of causing the turning shaft  31  on the right (left) to abut against the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) of the abutting portion  26  ( 25 ). Therefore, a configuration is illustrated here in which the tension N of the operation wire  16  and the tension (the tensile load) F of the tension spring  18  work in a direction of pulling the optical device holding frame  12  toward the proximal end lower side. 
     That is, since it is only required that the resultant force of the tension N of the operation wire  16  and the tension (the tensile load) F of the tension spring  18  works in the direction of causing the turning shaft  31  on the right (left) to abut against the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) of the abutting portion  26  ( 25 ), a configuration is also possible in which the tension N of the operation wire  16  or the tension (the tensile load) F of the tension spring  18  works in the upper side in a proximal end direction if the above condition is satisfied. 
     Sixth Modification 
       FIG. 12  is a right side view showing a configuration of a direction-of-view changing mechanism according to a sixth modification. 
     In the embodiment and each modification described above, a configuration has been illustrated in which the turning shafts  31  are provided on the optical device holding frame  12 , and the abutting portion  26  ( 25 ) configured with the two planar portions  26   a,    26   b  ( 25   a,    25   b ) are formed on the arm portion  23  ( 22 ). However, for example, as shown in  FIG. 12 , a configuration is also possible in which the abutting portion  26  ( 25 ) configured with the two planar portions  26   a,    26   b  ( 25   a,    25   b ) is formed on the proximal end side of the optical device holding frame  12 , and the turning shaft  31  on the right (left) is provided on the aim portion  23  ( 22 ) (in  FIG. 12 , the two planar portions  26   a  and  26   b  of the abutting portion  26  on the right side face are shown). 
     Note that, here, a configuration is adopted in which the abutting portion  26  ( 25 ) configured with the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ) is a recessedly formed V-shaped groove similar to the V-shaped groove of the first modification, and the tension spring  18  is arranged so that a biasing force is given to the proximal end side in the backward direction, and the tension (the tensile load) F is applied to the proximal end lower side of the optical device holding frame  12  toward the proximal end side. 
     Similarly to the fifth modification, the operation wire  16  is connected to the proximal end upper side of the optical device holding frame  12  here, and a state is shown in which the tension N by the operation wire  16  and the tension (the tensile load) F by the tension spring  18  are balanced. 
     Note that, instead of the abutting portion  26  ( 25 ) as a V-shaped groove configured with the two planar portions  26   a  and  26   b  ( 25   a  and  25   b ), the optical device holding frame  12  may be formed as a curved face which is in an arc groove shape recessedly formed in an R shape almost similar to the outer circumferential faces of the turning shafts  31 , similar to the second modification. 
     Note that though the tension spring  18  is used to cause the tension (the tensile load) F to be generated, in the embodiment and modifications described above, means for generating pulling force by another elastic member made of rubber or the like may be used instead. 
     Moreover, though an electronic endoscope provided with an image pickup device has been illustrated as the endoscope  1 , the endoscope  1  is not limited to an electronic endoscope. Each of the embodiment and modifications described above can be applied to a configuration in which a relay lens is provided to transfer a subject/object image. 
     The invention described in each of the embodiment and modifications described above is not limited to the embodiment and the modifications, but, additionally, various alterations can be performed at a stage of practicing the invention, within a range not departing from the spirit of the invention. Moreover, each of the embodiment and modifications described above includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent features. 
     For example, even if some constituent features are deleted from all constituent features shown in each of the embodiment and modifications, a configuration obtained after deleting the constituent features can be extracted as an invention if the stated problem can be solved, and the stated effects can be obtained. 
     According to the present invention, it is possible to provide an endoscope in which highly accurate positioning of an optical device to change a direction of view can be performed without backlash, and for which assembly workability is improved.