Endoscope

Abstract

To provide an endoscope that can be made smaller in diameter. [Solution] An endoscope comprising: an insertion portion inserted into a subject; an optical system including a first lens positioned on the tip side of the insertion portion; a sensor for capturing an optical image of a subject formed by the optical system; a first holding portion for holding the first lens; an axial member fixed to the first holding portion and extending toward the base end of the first holding portion; an actuator for moving the axial member in the optical axis direction along the optical axis of the optical system; and a first restricting portion for restricting the position of the axial member in a direction perpendicular to the optical axis, wherein the direction perpendicular to the optical axis is a first direction and a second direction perpendicular to the first direction, the length of the axial member in the first direction and the second direction is shorter than the diameter of the first lens, and the length between the tip of the first restricting portion and the base end of the first restricting portion in the optical axis direction is longer than the length of the first lens in the optical axis direction.

Description

Technical Field

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[0001] The technology of the present disclosure relates to an endoscope.

Background Art

[0002] In Patent Document 1, there is described an endoscope imaging device including an optical lens and an electrostatic actuator that moves the optical lens in the optical axis direction. The electrostatic actuator includes a moving body connected to the optical lens via a connecting rod, and an electrostatic vibration substrate interposed between the optical lens and the moving body and capable of moving the moving body in the optical axis direction by vibration.

[0003] In Patent Document 2, there is described an endoscope imaging lens unit including a photographing lens having a movable lens movable in the optical axis direction, a lens moving frame that holds the movable lens and moves it in the optical axis direction, and a cam shaft provided parallel to the optical axis of the photographing lens and engaged with the lens moving frame.

Prior Art Documents

Patent Documents

[0004] <00000@19>

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The technology of the present disclosure provides an endoscope that can be miniaturized.

Means for Solving the Problems

[0007] The technology disclosed herein makes it possible to reduce the diameter. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing an endoscope 1, which is one embodiment of the technology of this disclosure. [Figure 2] Figure 2 is an enlarged perspective view of the area near the tip 7 of endoscope 1. [Figure 3] Figure 3 is an exploded perspective view of the tip section 7 shown in Figure 2. [Figure 4] Figure 4 is an enlarged perspective view of a portion of the tip 7, seen from a different direction than in Figure 2. [Figure 5] Figure 5 is a view of Figure 4 from above (U). [Figure 6] Figure 6 shows the tip portion 7 as viewed from the tip direction Fr. [Figure 7] Figure 7 is a schematic cross-sectional view taken along the line AA in Figure 6. [Figure 8] Figure 8 is a schematic cross-sectional view taken along the BB arrow shown in Figure 7. [Figure 9] Figure 9 is a schematic diagram showing a modified arrangement of the shaft member 33. [Figure 10] FIG. 10 is a schematic diagram showing a modified example of the arrangement of the sensor 37. [Figure 11] FIG. 11 is a schematic diagram showing a modified example of the substrate 38. [Figure 12] FIG. 12 is a schematic diagram showing a modified example of the arrangement of the prism 36, the sensor 37, and the substrate 38. [Figure 13] FIG. 13 is a schematic diagram showing a first modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 14] FIG. 14 is a schematic diagram showing a second modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 15] FIG. 15 is a schematic diagram showing a third modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 16] FIG. 16 is a schematic diagram showing a fourth modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 17] FIG. 17 is a schematic diagram showing a fifth modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 18] FIG. 18 is a schematic diagram showing a sixth modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 19] FIG. 19 is a schematic diagram showing a seventh modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 20] FIG. 20 is a schematic diagram showing an eighth modified example of the imaging unit 300 and the housing member 71, and is a view showing the A-A cross-sectional view of FIG. 6. [Figure 21] FIG. 21 is a schematic diagram showing a first modified example of the second restricting portion 322, and is a view showing the B-B cross-sectional view of FIG. 7. [Figure 22] FIG. 22 is a schematic diagram showing a second modified example of the second restricting portion 322, and is a view showing the B-B cross-sectional view of FIG. 7. [Figure 23] FIG. 23 is a schematic diagram showing a third modified example of the second restricting portion 322, and is a view showing the B-B cross-sectional view of FIG. 7. [Figure 24] FIG. 24 is a schematic diagram showing a fourth modification of the second regulation unit 322, and is a view showing a B-B arrow view of FIG. 7. [Figure 25] FIG. 25 is a perspective view showing an external configuration of a housing member 71A that houses the imaging unit 300 of the modification. [Figure 26] FIG. 26 is a schematic cross-sectional view taken along the C-C arrow of FIG. 25. [Figure 27] FIG. 27 is a schematic cross-sectional view taken along the D-D arrow of FIG. 26. [Figure 28] FIG. 28 is a schematic diagram showing a ninth modification of the imaging unit 300 and the housing member 71, and is a view showing an A-A arrow view of FIG. 6.

Embodiments for Carrying Out the Invention

[0009] FIG. 1 is a schematic diagram showing an endoscope 1 which is an embodiment of the technology of the present disclosure. The endoscope 1 in the figure includes a long insertion portion 2 inserted into a subject, an operation portion 3 connected to the proximal end of the insertion portion 2 and used for gripping and operating the endoscope 1, and a universal cord 4 for connecting the endoscope 1 to system component devices such as a light source device and a processor device not shown. The technology of the present embodiment is not particularly limited, but can be preferably applied to a nasal endoscope having a diameter of 6 mm or less at the distal end 7 of the insertion portion 2. Further, it can be preferably applied to an endoscope in which the difference between the diameter of the distal end 7 and the diameter of the forceps port 26 provided at the distal end 7 is less than 6 mm.

[0010] The insertion portion 2 is composed of a flexible portion 5, a bending portion 6, and a distal end portion 7 that are connected in order from the proximal end to the distal end. The flexible portion 5 has flexibility and bends in an arbitrary direction along the insertion path of the insertion portion 2. The operation portion 3 is provided with angle knobs 8, 9, a treatment tool inlet 12, an air / water supply button 10, a suction button 11, and the like.

[0011] The curved section 6 can bend in the up / down and left / right directions by operating the angle knobs 8 and 9, respectively. Treatment instruments such as forceps are inserted through the treatment instrument introduction port 12 and led out through the forceps port 26 (see Figure 2) provided on the tip section 7. The tip section 7 is also provided with an observation window 30 (see Figure 2) for photographing the area to be observed inside the body, and a first illumination window 24 and a second illumination window 22 (see Figure 2) for illuminating the area to be observed.

[0012] The insertion section 2 moves along its axial direction and is inserted into the subject, and by rotating the angle knobs 8 and 9 of the operating section 3, the curved section 6 of the insertion section 2 bends in the up, down, left, and right directions. This allows the tip 7 of the insertion section 2 to be directed in a desired direction inside the body, and observation images can be acquired through the observation window 30 provided in the tip 7.

[0013] In the following, the direction from the base end to the tip of the insertion section 2 will be referred to as the tip direction Fr, and the direction opposite to the tip direction Fr will be referred to as the base direction Rr. The tip direction Fr and the base direction Rr will be collectively referred to as the longitudinal axis direction of the insertion section 2, or the optical axis direction in which the optical axis AX of the optical system OP described later extends. Two directions perpendicular to the longitudinal axis direction of the insertion section 2 and perpendicular to each other will be referred to as the up-down direction and the left-right direction. One of the up-down directions will be referred to as the up direction U, and the direction opposite to the up direction U will be referred to as the down direction D. One of the left-right directions will be referred to as the right direction R, and the direction opposite to the right direction R will be referred to as the left direction L.

[0014] Figure 2 is an enlarged perspective view of the area around the tip 7 of the endoscope 1. Figure 3 is an exploded perspective view of the tip 7 shown in Figure 2. Figure 4 is an enlarged perspective view of a part of the tip 7 from a different direction than in Figure 2. Figure 5 is a view of Figure 4 from above (U). Figure 6 is a view of the tip 7 from the tip direction (Fr). Figure 7 is a schematic cross-sectional view taken along the arrow AA in Figure 6.

[0015] As shown in Figure 3, the insertion section 2 contains a group of internal components OB, which includes multiple elongated internal components from the base to the tip. The group of internal components OB includes an imaging unit 300, a left light guide 220 and a right light guide 240, each composed of bundles of multiple optical fibers, a treatment instrument conduit 260 through which treatment instruments such as forceps or puncture needles are inserted, and a fluid conduit 270 for the flow of liquid or gas.

[0016] As shown in Figures 2 and 3, the tip section 7 includes a housing member 71 that houses and holds the imaging unit 300, the left light guide 220, the right light guide 240, the treatment instrument conduit 260, and the fluid conduit 270, and a tip cap 72 fixed to the tip side of the housing member 71.

[0017] The curved section 6 has a curved saddle section formed by connecting a plurality of annular members so that they can rotate relative to each other. As shown in Figure 2, the curved saddle section is provided with a connecting member 62 at its foremost end for connecting the housing member 71 of the tip section 7 with the curved section 6. The tip section 7 and the curved section 6 are connected by fixing the connecting member 62 to the housing member 71 with screws or the like.

[0018] As shown in Figure 3, the housing member 71 comprises a cylindrical main body portion 710, an extended portion 711 extending from the left end and base end of the main body portion 710 in the direction Rr toward the base end, and an extended portion 712 extending from the right end and base end of the main body portion 710 in the direction Rr toward the base end.

[0019] The main body 710 is provided with a plurality of holes that penetrate in the direction of the optical axis. The plurality of holes include an insertion hole 24B through which the right light guide 240 is inserted and fixed, an insertion hole 30B through which the imaging unit 300 is inserted and fixed, an insertion hole 22B through which the left light guide 220 is inserted and fixed, an insertion hole 26B through which the treatment instrument conduit 260 is inserted and fixed, and an insertion hole 27A through which the fluid conduit 270 is inserted and fixed.

[0020] The tip cap 72 is provided with an insertion hole 30A facing the insertion hole 30B, an insertion hole 22A facing the insertion hole 22B, an insertion hole 24A facing the insertion hole 24B, an insertion hole 26A facing the insertion hole 26B, and an insertion hole facing the insertion hole 27A. The air supply and water supply nozzle 27 is inserted from the tip side through the insertion hole facing the insertion hole 27A.

[0021] In its assembled state, as shown in Figure 2, the observation window 30 is formed by the tip (objective lens 31A) of the imaging unit 300 inserted through the insertion hole 30A. The second illumination window 22 is formed by the tip of the left light guide 220 inserted through the insertion hole 22A. The first illumination window 24 is formed by the tip of the right light guide 240 inserted through the insertion hole 24A. The forceps port 26 is formed by the tip of the treatment instrument conduit 260 inserted through the insertion hole 26A. The observation window 30, the first illumination window 24, the second illumination window 22, the forceps port 26, and the air / water supply nozzle 27 each constitute a functional element.

[0022] The imaging unit 300 has an optical system OP that includes a fixed lens holder 31 that holds a fixed lens group including an objective lens 31A, a movable lens holder 32 that holds a movable lens group including at least one movable lens 32A such as a focus lens or zoom lens, and a prism 36 (see Figure 4) positioned closer to the base end than the fixed lens group and the movable lens group. Figure 3 shows the optical axis AX of the optical system OP.

[0023] As shown in Figure 7, the fixed lens holder 31 is fixed to the insertion hole 30B of the housing member 71. The movable lens holder 32 is provided within the insertion hole 30B so as to be movable in the optical axis direction.

[0024] As shown in Figure 4, the imaging unit 300 includes a sensor 37, such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, which captures an optical image of a subject formed by the optical system OP; a substrate 38 on which the sensor 37 is mounted; and a cable 39 connected to the substrate 38.

[0025] As shown in Figure 5, the optical system OP has its optical axis AX aligned with the longitudinal axis of the insertion section 2. Light that passes through the fixed lens group and the movable lens group and enters the prism 36 is reflected by the light-reflecting surface of the prism 36 and travels downward D, and is emitted from the light-emitting slope. The light-receiving surface of the sensor 37 is positioned opposite this light-emitting slope and is aligned with the optical axis AX.

[0026] As shown in Figure 4, the substrate 38 includes a first substrate portion 381 on which the sensor 37 is provided, and a second substrate portion 382 located at the base end of the first substrate portion 381. The substrate 38 is formed by folding a long, flexible substrate twice. The substrate 38 is folded back in the direction of the tip Fr at the base end of the first substrate portion 381, and then folded back again in the direction of the base end Rr, forming a roughly Z shape. The sensor 37 and the cable 39 are electrically connected by wiring provided on the substrate 38.

[0027] As shown in Figure 3, the imaging unit 300 includes an axial member 33 fixed to the movable lens holder 32 and extending toward the base end of the movable lens holder 32, and an actuator 34 that moves the axial member 33 in the optical axis direction along the optical axis AX.

[0028] In the example shown in Figure 6, the shaft member 33 is positioned to the left of the fixed lens group and the movable lens group, and the shaft member 33 and the fixed lens group and the movable lens group are arranged side by side in the left-right direction. The maximum vertical length 33La of the shaft member 33 is shorter than the diameter φ of the movable lens 32A (or the largest diameter of the lenses if the movable lens group includes multiple lenses). Also, the maximum horizontal length 33Lb of the shaft member 33 is shorter than the diameter φ of the movable lens 32A. This configuration makes it possible to reduce the diameter of the insertion portion 2.

[0029] Furthermore, the maximum length 33La of the shaft member 33 is smaller than the maximum vertical length of the observation window 30, the first illumination window 24, the second illumination window 22, the forceps port 26, and the air / water supply nozzle 27. The maximum length 33Lb of the shaft member 33 is smaller than the maximum horizontal length of the observation window 30, the first illumination window 24, the second illumination window 22, the forceps port 26, and the air / water supply nozzle 27. This thin shaft member 33 makes it possible to reduce the diameter of the tip portion 7.

[0030] As shown in Figure 7, the shaft member 33 is inserted through a through hole 32B that penetrates the movable lens holder 32 from the base end to the tip end. The shaft member 33 is fixed to the movable lens holder 32 in this through hole 32B by press-fitting, welding, or adhesive. The tip end of the shaft member 33 protrudes beyond the through hole 32B and extends beyond the tip end of the movable lens holder 32.

[0031] The extension portion 711 of the housing member 71 is provided with a through-hole 711A through which the shaft member 33 is inserted so as to be movable in the optical axis direction. The gap between the inner surface of the through-hole 711A and the shaft member 33 is such that the shaft member 33 can move in the optical axis direction, but cannot move in the vertical and horizontal directions. With this gap set, the position of the shaft member 33 in the direction perpendicular to the optical axis AX (vertical and horizontal directions) is restricted by the inner surface of the through-hole 711A. The inner surface of the through-hole 711A constitutes a first region 331 of the first restricting portion that restricts the position of the shaft member 33 in the direction perpendicular to the optical axis AX. The maximum lengths 33La and 33Lb shown in Figure 6 are the lengths (maximum widths in the horizontal and vertical directions) of the portion of the shaft member 33 that is inserted into the through-hole 711A.

[0032] By restricting the left-right position of the shaft member 33, the left-right position of the movable lens holder 32, which is fixed to the shaft member 33, can be maintained in a desired state, preventing the movable lens group from tilting in the direction of the optical axis. The first region 331 can be said to restrict the position of the movable lens holder 32 in the left-right direction and the relative angle between the optical axis AX and the movable lens holder 32 (corresponding to the angle between the optical axis of the movable lens 32A and the optical axis AX, which is the tilt angle of the movable lens group) in a side view when viewed in the vertical direction, and to be in contact with the shaft member 33.

[0033] By increasing the length LA in the optical axis direction of the first region 331 (synonymous with the length between the tip and base of the first restricting portion), the tilt prevention effect of the movable lens group can be enhanced. For example, by making the length LA longer than the length LB in the optical axis direction of the movable lens 32A (the minimum length if the movable lens group includes multiple lenses), the tilt prevention effect can be enhanced. Furthermore, by making the length LA longer than the diameter φ of the movable lens 32A (the minimum diameter if the movable lens group includes multiple lenses), the tilt prevention effect can be enhanced.

[0034] The anti-tipping effect can be further enhanced by increasing the length of the portion of the shaft member 33 that is inserted into the through hole 711A. For example, the anti-tipping effect can be enhanced by positioning the base end of the shaft member 33 on the base end side of the light incident surface 36A of the prism 36. Furthermore, the anti-tipping effect can be further enhanced by positioning the base end of the shaft member 33 on the base end side of the light receiving surface of the sensor 37.

[0035] Furthermore, in the insertion hole 711A, a separate member may be provided between it and the shaft member 33 to fill these gaps, thereby restricting the left-right position of the shaft member 33.

[0036] In the endoscope 1, the fixed lens holder 31, left light guide 220, right light guide 240, treatment instrument conduit 260, and fluid conduit 270 are fixed to the housing member 71. By using a part of the housing member 71, which has the function of housing the internal components OB, to form the first region 331, it becomes possible to reduce the diameter of the tip 7.

[0037] The actuator 34 is provided on the base end side of the shaft member 33, and its tip end face 340Fr (see Figure 7) is in contact with the base end face 33Rr (see Figure 7) of the shaft member 33. The actuator 34 includes a motor and a movable part that can move in the optical axis direction by the rotation of the motor, and the movement of this movable part moves the shaft member 33. As the shaft member 33 moves, the movable lens 32A held in the movable lens holder 32 moves in the movement region R1 shown in Figure 7. The first region 331 of the shaft member 33 is located on the base side of the base end of the movement region R1.

[0038] Figure 7 shows the actuator 34, which consists of a sliding screw 340 as a movable part and a flexible shaft 341 connected to the sliding screw 340. The sliding screw 340 is inserted through a through hole provided in the extended part 711. The flexible shaft 341 is connected to a motor provided in the operating part 3. When this motor rotates, the flexible shaft 341 and the sliding screw 340 connected to it rotate, causing the sliding screw 340 to move in the direction of the optical axis.

[0039] As illustrated in Figure 7, it is preferable that the length LAa of the portion of the shaft member 33 closer to the base end than the movable lens holder 32 is longer than the length LA of the first region 331. This allows the actuator 34 to press the shaft member 33 outside the insertion hole 711A. This relaxes the restrictions on the lateral position of the actuator 34. For example, as shown in Figure 7, the distance L6 between the center of gravity 34C of the actuator 34 and the optical axis AX can be made shorter than the distance L7 between the center of gravity 33C of the shaft member 33 and the optical axis AX. In other words, the actuator 34 can be positioned closer to the optical axis AX than the shaft member 33, making it possible to reduce the diameter of the tip portion 7.

[0040] Furthermore, as shown in Figure 7, it is also possible to configure the shaft member 33 so that one end E1 on the optical system OP side of the end face 33Rr of the shaft member 33 is located on the opposite side of the optical system OP from the end face E2 on the optical system OP side of the end face 340Fr of the actuator 34, and the other end E3 on the opposite side of the optical system OP from the end face 33Rr of the shaft member 33 is located on the opposite side of the optical system OP from the other end E4 on the opposite side of the end face 340Fr of the actuator 34. This configuration makes it possible to reduce the diameter of the tip portion 7.

[0041] As shown in Figures 6 and 7, the fixed lens holder 31 is provided with a projection 310 that protrudes to the left L from the area housing the fixed lens group. The projection 310 overlaps with the tip of the shaft member 33 when viewed in the direction of the optical axis. A compression spring 35, acting as a biasing member, is provided around the tip of the shaft member 33 with initial tension applied. The compression spring 35 biases the movable lens holder 32 toward the base end. By biasing the movable lens holder 32 toward the base end in this way, the contact between the shaft member 33 and the actuator 34 can be improved, thereby improving the accuracy of movement of the shaft member 33 by the actuator 34.

[0042] In the example shown in Figure 7, the movable lens 32A is positioned at the base end of the moving region R1, and the end face 33Rr of the shaft member 33 and the end face 340Fr of the actuator 34 are in contact. However, in this state, the end face 33Rr and the end face 340Fr do not necessarily have to be in contact.

[0043] For example, in Figure 7, the sliding screw 340 may be in a state where it has moved slightly backward. In this way, even if the end face 33Rr and the end face 340Fr do not come into contact in the state shown in Figure 7, the position of the movable lens holder 32 can be maintained with high precision by the biasing force of the compression spring 35 pressing the movable lens holder 32 against the extended portion 711.

[0044] With this configuration, in the state shown in Figure 7, there is no need to move the sliding screw 340 to a position where it contacts the shaft member 33, thus simplifying the control of the actuator 34. In addition, the contact between the movable lens holder 32 and the extended portion 711 allows the movable lens 32A to be positioned with high precision at the base end of the movement region R1. On the other hand, when moving the movable lens 32A to a position other than the base end of the movement region R1, the contact between the shaft member 33 and the sliding screw 340 allows the position of the movable lens 32A to be determined with high precision.

[0045] Figure 8 is a schematic cross-sectional view taken along the BB arrow shown in Figure 7. As shown in Figure 8, the shaft member 33 has a circular cross-section. The movable lens holder 32 comprises an annular region 320 that accommodates the movable lens 32A, and a linear region 321 that extends to the left in direction L from region 320, with the shaft member 33 inserted and fixed through region 321.

[0046] The movable lens holder 32 further includes a second restricting portion 322 that restricts the rotation of the shaft member 33 of the movable lens holder 32 around its axis, in other words, the vertical rotation of the movable lens holder 32.

[0047] The second restricting portion 322 is provided around the region 320 and consists of a projection 322A projecting upward U from the upper end of the region 320 and a projection 322A projecting downward D from the lower end of the region 320. The gap between the second restricting portion 322 and the inner circumferential surface 710S of the main body portion 710 is set to a size that allows the movable lens holder 32 to move in the optical axis direction, but prevents the movable lens holder 32 from rotating. By providing the second restricting portion 322, vertical movement of the movable lens group can be prevented.

[0048] The length of the second regulating section 322 in the optical axis direction is shorter than the length of the first region 331 in the optical axis direction. In other words, the length of the first region 331 in the optical axis direction is longer than the length of the second regulating section 322 in the optical axis direction.

[0049] In the endoscope 1, the first region 331 of the first restricting section prevents the movable lens group from tilting in the optical axis direction, and the second restricting section 322 prevents the movable lens group from rotating in the vertical direction, thus simplifying the structure of each restricting section. Furthermore, by providing two separate restricting sections, the length of the second restricting section 322 in the optical axis direction can be made shorter than that of the first region 331. This allows for efficient use of space within the tip section 7, enabling a smaller diameter.

[0050] Furthermore, the first region 331 and the second restricting portion 322 are located at different positions in the left-right direction. This allows for efficient use of space within the tip portion 7, enabling a reduction in diameter. Also, in the left-right direction, the first region 331 is located in a different region from the movable lens group, while the second restricting portion 322 is located closer to the movable lens group than the first region 331 (preferably in a region overlapping with the movable lens group). By preventing the vertical rotation of the movable lens group at a position close to the lenses, the structure of the second restricting portion 322 can be simplified.

[0051] As shown in Figure 6, it is preferable that the shaft member 33 is located closer to the observation window 30 than to the first illumination window 24. In other words, it is preferable that the distance between the centers of the shaft member 33 and the observation window 30 is smaller than the distance between the centers of the first illumination window 24 and the observation window 30.

[0052] Furthermore, it is preferable that the shaft member 33 is located on the outer edge side of the tip surface 14, rather than on the first illumination window 24 and the observation window 30. In other words, it is preferable that the distance L5 between the center CP of the tip surface 14 and the center of the shaft member 33 is greater than the distance L1 between the center CP of the tip surface 14 and the center of the first illumination window 24, and greater than the distance L4 between the center CP of the tip surface 14 and the center of the observation window 30.

[0053] Furthermore, it is preferable that the shaft member 33 is located on the opposite side of the air / water supply nozzle 27 with respect to the line DL connecting the centers of the observation window 30 and the forceps opening 26.

[0054] Furthermore, it is preferable that the distance L5 from the center CP to the center of the shaft member 33 is greater than the distances (distances L1, L2, L3, and L4) from the center CP to each functional element. In other words, the center of the shaft member 33 may be located on the outer edge side of the tip surface 14, rather than the center of the observation window 30 and the centers of the other functional elements.

[0055] These configurations make it possible to reduce the diameter of the tip portion 7.

[0056] Furthermore, as shown in Figure 6, the center of the shaft member 33 may be located in the region between a line extending from the center CP of the tip surface 14 and passing through the center of the observation window 30, and a line extending from the center CP of the tip surface 14 and passing through the centers of each functional element other than the observation window 30. In the example in Figure 6, the center of the shaft member 33 is located in the region between a line extending from the center CP of the tip surface 14 and passing through the center of the observation window 30, and a line extending from the center CP of the tip surface 14 and passing through the center of the second illumination window 22. This example is not limited to this one; for example, the center of the shaft member 33 may be located in the region between a line extending from the center CP of the tip surface 14 and passing through the center of the observation window 30, and a line extending from the center CP of the tip surface 14 and passing through the center of the first illumination window 24.

[0057] Figure 9 is a schematic diagram showing a modified arrangement of the shaft member 33. As shown in Figure 9, the center of the shaft member 33 may be located closer to the center CP of the tip surface 14 than the center of the observation window 30 and the centers of other functional elements. In other words, the distance L5 may be smaller than the distance L1-L4.

[0058] The sensor 37 is configured such that its light-receiving surface is aligned with the optical axis AX, but this configuration is not limited to this. For example, as shown in Figure 10, the prism 36 can be removed, and a sensor 37 with a light-receiving surface 37A positioned perpendicular to the optical axis AX can be installed in the position of the prism 36. In this configuration, it is preferable that the sensor 37 and the actuator 34 overlap when viewed from the tip side. This makes it possible to reduce the diameter of the tip portion 7.

[0059] Figure 11 is a schematic diagram showing a modified example of the substrate 38. In the configuration shown in Figure 11, the center 382A of the second substrate portion 382 in the direction along the short side of the sensor 37 (left-right direction) is shifted away from the shaft member 33 and actuator 34 compared to the center 381A of the first substrate portion 381 in the left-right direction. With this configuration, the space between the second substrate portion 382 and the extended portion 711 can be effectively utilized, enabling a reduction in diameter. In addition, the prism 36 and actuator 34 can be arranged to overlap when viewed in the axial direction, enabling a reduction in the diameter of the tip portion 7.

[0060] Figure 12 is a schematic diagram showing a modified arrangement of the prism 36, sensor 37, and substrate 38. In the configuration shown in Figure 12, the prism 36, sensor 37, and substrate 38 are rotated 90 degrees towards the front of the paper around the optical axis AX compared to the configuration in Figure 5. In the configuration shown in Figure 12, the axial member 33 is provided on the opposite side of the sensor 37, with a plane passing through the optical axis AX and parallel to the light-receiving surface 37A of the sensor 37. Even with such a configuration, the diameter can be reduced using the technology of this disclosure.

[0061] Figure 13 is a schematic diagram showing a first modified example of the imaging unit 300 and the housing member 71, and is a view taken along arrow AA in Figure 6. The configuration shown in Figure 13 differs from the configuration in Figure 7 in that the tip region of the shaft member 33, which extends further toward the tip than the shaft member 33, is inserted into the through hole 710A formed in the main body 710.

[0062] The gap between the inner surface of the insertion hole 710A and the tip region of the shaft member 33 is such that the shaft member 33 can move in the optical axis direction, but cannot move in the vertical and horizontal directions. With this gap set, the position of the shaft member 33 in the vertical and horizontal directions is also restricted by the inner surface of the insertion hole 710A. The inner surface of the insertion hole 710A forms a second region 332 of the first restricting section that restricts the position of the shaft member 33 in the direction perpendicular to the optical axis AX. The second region 332 of the shaft member 33 is located closer to the tip than the tip of the movement region R1.

[0063] In this way, by providing a second region 332 in addition to the first region 331, the anti-tilting effect of the movable lens group can be enhanced. In the optical axis direction, the anti-tilting effect can be enhanced by making the length L10 between the base end of the first restricting part (the base end of the first region 331) and the tip of the first restricting part (the tip of the second region 332) longer than the optical axis direction length LB of the movable lens 32A. Furthermore, the anti-tilting effect can be enhanced by making the length L10 longer than the diameter φ of the movable lens 32A. By providing the second region 332 on the tip side of the movable lens holder 32, the length of the first region 331 can be shortened, making it possible to save space in the optical axis direction.

[0064] Furthermore, in the insertion hole 710A, a separate member may be provided between it and the shaft member 33 to fill these gaps, thereby restricting the position of the shaft member 33.

[0065] Figure 14 is a schematic diagram showing a second modified example of the imaging unit 300 and housing member 71, and is a view taken along arrow AA in Figure 6. In the example shown in Figure 14, the protrusion 310 on the fixed lens holder 31 is removed, a wall is formed by a part of the main body 710 at a position opposite the tip of the shaft member 33, and a compression spring 35 is provided between this wall and the shaft member 33, which differs from the configuration in Figure 7. According to the configuration shown in Figure 14, the assembly accuracy of the tip portion 7 can be improved.

[0066] Figure 15 is a schematic diagram showing a third modified example of the imaging unit 300 and housing member 71, and is a view taken along arrow AA in Figure 6. The example shown in Figure 15 differs from the configuration in Figure 6 in that two magnets MG are provided instead of the compression spring 35.

[0067] One of the two magnets MG is provided on the projection 310, and the other of the two magnets MG is provided at the tip of the shaft member 33. The polarity of the two magnets MG is determined so that they repel each other. As a result, the shaft member 33 is biased toward the actuator 34. With the configuration shown in Figure 15, durability can be increased compared to when a spring is used as the biasing means.

[0068] Figure 16 is a schematic diagram showing a fourth modified example of the imaging unit 300 and housing member 71, and is a view taken along arrow AA in Figure 6. In the example shown in Figure 16, the position of the compression spring 35 has been changed to be between the fixed lens holder 31 and the movable lens holder 32, which differs from the configuration in Figure 7.

[0069] The compression spring 35 biases the movable lens holder 32 toward the base end. According to the configuration in Figure 16, the compression spring 35 is placed in the space that should be provided between the fixed lens holder 31 and the movable lens holder 32, which makes it possible to miniaturize the tip portion 7.

[0070] Figure 17 is a schematic diagram showing a fifth modified example of the imaging unit 300 and the housing member 71, and is a view taken along arrow AA in Figure 6. In the example shown in Figure 17, the shaft member 33 does not have a region that extends beyond the tip of the movable lens holder 32, which is different from the configuration in Figure 7. Even with the configuration shown in Figure 17, the provision of the first region 331 provides an effect to prevent the movable lens group from tipping over. Furthermore, the configuration shown in Figure 17 allows for a simpler structure than the configuration shown in Figure 7, enabling reduced manufacturing costs and miniaturization.

[0071] Figure 18 is a schematic diagram showing a sixth modified example of the imaging unit 300 and the housing member 71, and is a view taken along arrow AA in Figure 6. In the example shown in Figure 18, the shaft member 33 does not have a region that extends beyond the tip of the movable lens holder 32, the compression spring 35 is removed and replaced with a magnet MG at the base end of the shaft member 33, and a Hall element HA is added as a magnetic detection element, which differs from the configuration in Figure 7.

[0072] The Hall element HA is provided in the extension portion 711 near the magnet MG. The sliding screw 340 is made of a magnetic material. Therefore, the magnet MG is attracted to the sliding screw 340. As a result, the movable lens holder 32 and the shaft member 33 are biased toward the actuator 34. The magnet MG and the Hall element HA constitute a position detection unit that detects the position of the shaft member 33 in the optical axis direction. In this way, by using the magnet MG as a biasing means as a position detection unit, the number of parts can be reduced. In addition, miniaturization is possible because the compression spring 35 on the tip side is eliminated.

[0073] Figure 19 is a schematic diagram showing a seventh modified example of the imaging unit 300 and the housing member 71, and is a view taken along arrow AA in Figure 6. In the example shown in Figure 19, the configuration of the actuator 34 differs from that in Figure 7.

[0074] In the example shown in Figure 19, the actuator 34 includes a piezoelectric element 343 and a rod 342 that is movable in the optical axis direction by the operation of the piezoelectric element 343, and the movement of the rod 342 moves the shaft member 33. The piezoelectric element 343 is composed of multiple elements stacked together, for example, and is extendable and retractable in the optical axis direction. The rod 342 is fixed to the piezoelectric element 343 and extends beyond the piezoelectric element 343 towards the tip. The tip end face 342Fr of the rod 342 is in contact with the end face 33Rr of the shaft member 33. The rod 342 is held against the extended portion 711 with appropriate friction. For example, the rod 342 is held against the extended portion 711 by a leaf spring or the like. A magnet MG is provided on the base end side of the piezoelectric element 343, and a Hall element HA is provided near the magnet MG.

[0075] The relationship between the distance L6 between the center of gravity 34C of the actuator 34 and the optical axis AX, and the distance L7 between the center of gravity 33C of the shaft member 33 and the optical axis AX, is the same as in Figure 7. Also, the configuration in which the right end of the end face 33Rr of the shaft member 33 is located to the left of the right end of the end face 342Fr of the actuator 34, and the left end of the end face 33Rr of the shaft member 33 is located to the left of the left end of the end face 342Fr of the actuator 34, is the same as in Figure 7.

[0076] The piezoelectric element 343 repeatedly extends at a low speed and retracts at a high speed, or vice versa, causing the rod 342 and the extended portion 711 to repeatedly slip and stop. This causes the piezoelectric element 343 and the rod 342 to move in the optical axis direction, and the shaft member 33 and the movable lens holder 32 to move in the optical axis direction. The magnet MG and the Hall element HA constitute a position detection unit that detects the position of the shaft member 33 in the optical axis direction. Compared to the configuration shown in Figure 7, the configuration shown in Figure 19 eliminates the need to extend the flexible shaft throughout the entire insertion portion 2, thus simplifying the structure of the insertion portion 2.

[0077] Figure 20 is a schematic diagram showing an eighth modified example of the imaging unit 300 and housing member 71, and is a view taken along arrow AA in Figure 6. The configuration shown in Figure 20 is the same as the configuration shown in Figure 19, but with the addition of one set of movable lens 32A, movable lens holder 32, shaft member 33, compression spring 35, and actuator 34. As shown in Figure 20, the technology of this disclosure can also be applied when it is desired to move multiple movable lenses 32A individually.

[0078] Figure 21 is a schematic diagram showing a first modified example of the second restricting section 322, and is a view taken along the arrow BB in Figure 7. In the example shown in Figure 21, one of the two protrusions 322A shown in Figure 8 is removed, and instead, a member 322B is added to the outer circumferential surface of the movable lens holder 32 to fill the gap between this outer circumferential surface and the main body 710. The gap between the member 322B and the protrusion 322A and the main body 710 is set to such an extent that the movable lens holder 32 can move in the optical axis direction, but the movable lens holder 32 cannot rotate around the axis of the axial member 33. Note that in Figure 21, the protrusion 322A may be replaced with member 322B.

[0079] Figure 22 is a schematic diagram showing a second modified example of the second restricting portion 322, and is a view taken along the arrow BB in Figure 7. In the example shown in Figure 22, a magnet MG is provided on the inner circumference of the main body portion 710 at a position opposite to the projection 322A, and the projection 322A is made of at least a magnetic material, which is different from Figure 8.

[0080] In the example shown in Figure 22, the gap between the projection 322A and the main body 710 may be wide enough to allow the movable lens holder 32 to rotate vertically. In the example in Figure 22, the vertical rotation of the movable lens holder 32 is restricted by the repulsive force between the magnet MG and the projection 322A. Thus, the projection 322A and the magnet MG can also constitute the second restricting portion 322.

[0081] Figure 23 is a schematic diagram showing a third modified example of the second restricting section 322, and is a view taken along the arrow BB in Figure 7. In the example shown in Figure 23, one of the two protrusions 322A shown in Figure 8 is removed, and instead, a leaf spring 322C is added to the outer circumferential surface of the movable lens holder 32 to fill the gap between this outer circumferential surface and the main body 710. The leaf spring 322C extends to the right from the same position as the protrusion 322A in the left-right direction, along the outer circumferential surface of the region 320, with its right end fixed to the inner circumferential surface 710S, and its left end contacting the region 320 near the opposite position of the protrusion 322A, biasing it in the direction of the protrusion 322A.

[0082] The configuration shown in Figure 23 enhances the effect of preventing rotation of the movable lens group in the vertical direction.

[0083] Figure 24 is a schematic diagram showing a fourth modified example of the second restricting section 322, and is a view taken along the arrow BB in Figure 7. In the example shown in Figure 24, the two protrusions 322A are removed from the configuration shown in Figure 8, and a protrusion 322D is provided at the right end of the region 320, projecting to the right in direction R. The main body 710 is provided with a recess 322E that receives the protrusion 322D so as to be movable in the optical axis direction. The insertion of the protrusion 322D into the recess 322E restricts the vertical rotation of the movable lens holder 32. The protrusion 322D and the recess 322E constitute the second restricting section 322.

[0084] In the example shown in Figure 24, the second restricting section 322 is located on the opposite side of the optical axis AX from the first restricting section (first region 331) in the left-right direction. This configuration enhances the effect of preventing the movable lens group from rotating in the vertical direction.

[0085] In the description so far, the housing member 71 has been assumed to house the imaging unit 300 and the left light guide 220, the right light guide 240, the treatment instrument conduit 260, and the fluid conduit 270, but it is not limited to this. The housing member for housing the imaging unit 300 and the housing member for housing the left light guide 220, the right light guide 240, the treatment instrument conduit 260, and the fluid conduit 270 may be provided independently.

[0086] Figure 25 is a perspective view showing the external configuration of a housing member 71A that houses a modified imaging unit 300. The housing member 71A comprises a first housing area 91 for housing the lenses of the optical system OP, and a second housing area 92 for housing a mechanism for moving the movable lenses included in the optical system OP.

[0087] Figure 26 is a schematic cross-sectional view taken along the CC arrow in Figure 25. The optical system OP is provided with two movable lenses 32A. The fixed lens group housed in the first housing area 91 is not shown.

[0088] Inside the housing member 71A, two movable lens holders 32 for holding the movable lens 32A are provided, aligned in the direction of the optical axis. Each movable lens holder 32 comprises a region 32R for housing the movable lens 32A and a region 32L to the left of region 32R. Region 32L is longer in the direction of the optical axis than region 32R.

[0089] Inside the second housing area 92, a camshaft CS is provided, extending in the direction of the optical axis, and rotates due to the rotation of a flexible shaft 341 connected to a motor. A through-hole 32B is provided in the area 32L of the movable lens holder 32, through which the camshaft CS passes. An engaging projection 32X is provided in the area 32L of the movable lens holder 32, which engages with a cam groove provided in the camshaft CS. When the flexible shaft 341 rotates due to the operation of the motor, the camshaft CS rotates around a rotation axis that extends in the direction of the optical axis. As a result, the engaging projection 32X moves along the cam groove, and the movable lens holder 32 moves in the direction of the optical axis. The gap between the inner circumferential surface of the through-hole 32B and the camshaft CS is set to be small enough that the movable lens holder 32 can move in the direction of the optical axis, but cannot move in the vertical or horizontal directions.

[0090] In the configuration shown in Figure 26, the camshaft CS extends beyond the base end of the movable lens holder 32 and connects to the movable lens holder 32 and the actuator (flexible shaft 341), forming an axial member that moves the movable lens holder 32 in the optical axis direction. Furthermore, the inner circumferential surface of the through hole 32B restricts the left-right position of the movable lens holder 32 and the relative angle between the optical axis AX and the movable lens holder 32, forming a first restricting portion that contacts the axial member. Alternatively, a member can be provided in the gap between the through hole 32B and the camshaft CS to fill this gap, allowing the camshaft CS to rotate but preventing it from moving in the vertical and left-right directions, and this member can also be considered the first restricting portion.

[0091] Figure 27 is a schematic cross-sectional view taken along the arrow DD in Figure 26. As shown in Figure 27, the housing member 71A comprises a first portion P1 that accommodates the through hole 32B constituting the first restricting portion, a second portion P2 that is narrower in the vertical direction than the first portion P1, and a third portion P3 that is wider in the vertical direction than the second portion P2. Note that in Figure 8, the configuration of the housing member 71A shown in Figure 27 may also be adopted.

[0092] As shown in Figure 27, the camshaft CS has a circular cross-section. The movable lens holder 32 comprises an annular region 320 that accommodates the movable lens 32A, an annular region 323 through which the camshaft CS is inserted, and a linear region 321 connecting region 320 and region 323. The movable lens holder 32 further includes a second restricting portion 322 that restricts the rotation of the movable lens holder 32 around the axis of the camshaft CS, in other words, the vertical rotation of the movable lens holder 32.

[0093] The second restricting portion 322 is provided around the region 320 and consists of a projection 322A projecting upward U from the upper end of the region 320 and a projection 322A projecting downward D from the lower end of the region 320. The gap between the second restricting portion 322 and the inner circumferential surface 710S of the main body portion 710 is set to be such that the movable lens holder 32 can move in the optical axis direction, but the movable lens holder 32 cannot rotate relative to the movable lens holder 32. By providing the second restricting portion 322, vertical movement of the movable lens group can be prevented.

[0094] The length of the second restricting portion 322 in the optical axis direction is shorter than the length of the inner circumferential surface of the through hole 32B in the optical axis direction.

[0095] In the configuration shown in Figures 25 to 27, the first restricting section (the inner surface of the through-hole 32B) prevents the movable lens group from tilting in the optical axis direction, and the second restricting section 322 prevents the movable lens group from rotating in the vertical direction. This simplifies the structure of each restricting section. Furthermore, by dividing the restricting section into two, the length of the second restricting section 322 in the optical axis direction can be made shorter than that of the first restricting section. This allows for efficient use of space within the tip section 7, enabling miniaturization.

[0096] Furthermore, the first restricting portion and the second restricting portion 322 are located at different positions in the left-right direction. This allows for efficient use of the space within the tip portion 7, enabling a reduction in diameter. Also, in the left-right direction, the first restricting portion is located in a different region from the movable lens group, while the second restricting portion 322 is located closer to the movable lens group than the first region 331 (preferably in a region overlapping with the movable lens group). By preventing the vertical rotation of the movable lens group at a position close to the lenses, the structure of the second restricting portion 322 can be simplified.

[0097] Furthermore, the second regulating section 322 shown in Figure 27 can be replaced with the configuration shown in Figures 21 to 24.

[0098] Figure 28 is a schematic diagram showing the eighth modified form of the imaging unit 300 and housing member 71, and is a view taken along arrow AA in Figure 6. The example shown in Figure 28 differs from the example shown in Figure 14 in that the fixed lens holder 31 is provided with an insertion hole 311 through which the tip end of the shaft member 33 is inserted, and the inner circumferential surface of this insertion hole 311 constitutes the second region 332 (first restricting portion), a compression spring 35 is provided between the movable lens holder 32 and the fixed lens group, the base end of the shaft member 33 beyond the movable lens holder 32 is not restricted in the vertical and horizontal directions by the extension portion 711, and the prism 36 is removed, and the light-receiving surface 37A of the sensor 37 is positioned perpendicular to the optical axis AX. Note that the actuator 34 shown in Figure 28 can be changed to a sliding screw 340, a flexible shaft 341, and a motor. In the configuration shown in Figure 28, a prism 36 may be added so that the light-receiving surface 37A of the sensor 37 is parallel to the optical axis AX. According to the configuration shown in Figure 28, the length of the imaging unit 300 and the housing member 71 in the optical axis direction can be reduced.

[0099] In all the configurations described so far, the relative positions of the sensor 37 and prism 36 (or sensor 37 only if the prism 36 is not required) and the housing member 71 are preferably determined as follows.

[0100] The sensor 37 (and prism 36) is finely adjusted perpendicular to the optical axis AX so that the optical axis AX is at the center of the effective pixel area of ​​the sensor 37, and the sensor 37 (and prism 36) is finely adjusted in the direction of the optical axis so that the best focus position is at the target position, thereby determining the relative position of the housing member 71 and the sensor 37 (and prism 36), and at that position the sensor 37 (and prism 36) is fixed to the housing member 71 with adhesive.

[0101] In this specification, "center" means the actual center, and anything near the center is interpreted as the "center."

[0102] As described above, this specification includes at least the following. The following parentheses describe, but are not limited to, components, etc., corresponding to the embodiments described above.

[0103] (1) An insertion part (insertion part 2) that is inserted into the subject, An optical system (optical system OP) including a first lens (movable lens 32A) is positioned at the tip of the insertion part described above, A sensor (sensor 37) that captures the optical image of the subject formed by the optical system described above, The first holding part (movable lens holder 32) that holds the first lens, A shaft member (shaft member 33) is fixed to the first holding portion and extends toward the base end side of the first holding portion, An actuator (actuator 34) moves the shaft member along the optical axis in the optical direction, The device comprises a first restricting section (first region 331, second region 332) that restricts the position of the axial member in a direction perpendicular to the optical axis, The above directions perpendicular to the optical axis are the first direction (left-right direction) and the second direction (up-down direction) perpendicular to the first direction. The shaft member described above has a length (maximum length 33La, 33Lb) in the first and second directions that is shorter than the diameter (diameter φ) of the first lens. An endoscope (endoscope 1) in which the length (length LA, length L10) between the tip and base of the first restricting portion in the optical axis direction is longer than the length (length LB) of the first lens in the optical axis direction.

[0104] (2) (1) The endoscope described above, An endoscope comprising a housing member (housing member 71) having a first hole (through hole 30B) through which the optical system is inserted, and a second hole (through hole 711A) through which the shaft member is inserted.

[0105] (3) (2) The endoscope described above, The first regulating portion described above is an endoscope provided on the inner circumference of the second hole described above.

[0106] (4) (2) or (3) an endoscope, The optical system described above includes a second lens (fixed lens group) and a second holding part (fixed lens holder 31) that holds the second lens. The second holding part described above is an endoscope fixed to the housing member described above.

[0107] (5) (1) The endoscope described above, The optical system described above includes a second lens (fixed lens group) and a second holding part (fixed lens holder 31) that holds the second lens. The above-mentioned second holding portion is an endoscope having a hole (insertion hole 311) that constitutes the first regulating portion through which the above-mentioned shaft member is inserted.

[0108] (6) (5) The endoscope described above, An endoscope comprising a housing member (housing member 71) having a hole (insertion hole 30B) through which the above-mentioned second holding portion is inserted.

[0109] (7) An endoscope described in any one of (2) to (6), The above-mentioned housing member is an endoscope having a third hole (insertion hole 22B, insertion hole 24B) through which a light guide is inserted.

[0110] (8) An endoscope described in any one of (1) to (7), The base end of the above-mentioned shaft member is located on the base end side of the light-receiving surface of the above-mentioned sensor, in the endoscope.

[0111] (9) An endoscope described in any one of (1) to (8), An endoscope in which the actuator and the sensor overlap when the insertion portion is viewed from the tip side.

[0112] (10) An endoscope described in any one of (1) to (9), The above optical system includes a prism (prism 36), The base end of the above-mentioned axial member is located on the base end side of the light incident surface (light incident surface 36A) of the above-mentioned prism, in the endoscope.

[0113] (11) (10) The endoscope described above, The above sensor is an endoscope in which the light-receiving surface is aligned with the optical axis and the light-receiving surface is positioned opposite the light-emitting surface of the prism.

[0114] (12) An endoscope described in any one of (1) to (11), The first direction mentioned above is the direction in which the first lens and the axial member are aligned. In the first direction described above, the axial member is provided on the opposite side of the optical axis from the sensor, in the endoscope.

[0115] (13) An endoscope described in any one of (1) to (12), The above sensor is provided on the substrate (substrate 38), The above-mentioned substrate includes a first substrate portion (first substrate portion 381) on which the above-mentioned sensor is provided, and a second substrate portion (second substrate portion 382) located on the proximal end side of the first substrate portion. An endoscope in which, when viewed from a direction perpendicular to the light-receiving surface of the sensor, the center of the second substrate portion in the direction along the short side of the sensor (center 382A) is shifted in a direction away from the shaft member and the actuator compared to the center of the first substrate portion in the direction along the short side of the sensor (center 381A).

[0116] (14) An endoscope described in any one of (1) to (13), The tip surface (tip surface 14) of the insertion section is provided with one of the following functional elements: an observation window (observation window 30), a first illumination window (first illumination window 24), a second illumination window (second illumination window 22), a forceps channel (forceps channel 26), or an air / water supply nozzle (air / water supply nozzle 27). When the tip surface is viewed in the direction of the optical axis, the center of the axial member of the endoscope is located in the region between a line that originates from the center of the tip surface and passes through the center of the observation window, and a line that originates from the center of the tip surface and passes through the center of the functional element.

[0117] (15) (14) The endoscope described above, In an endoscope where the tip surface is viewed in the direction of the optical axis, the center of the axial member is located on the outer edge side of the tip surface, relative to the center of the observation window and the center of the functional element.

[0118] (16) (14) The endoscope described above, In an endoscope, when the tip surface is viewed in the direction of the optical axis, the center of the axial member is located closer to the center of the tip surface than the center of the observation window and the center of the functional element.

[0119] (17) An endoscope according to any one of (1) to (13), wherein the tip surface (tip surface 14) of the insertion portion is provided with an observation window (observation window 30) and a plurality of functional elements, When the tip surface is viewed in the direction of the optical axis, the center of the axis member is located on the outer edge side or the center side of the tip surface, relative to the center of the observation window and the centers of the multiple functional elements. The above-mentioned functional elements are one of the following: an illumination window, an observation window, a forceps channel, and an air / water supply nozzle.

[0120] (18) (17) The endoscope described above, An endoscope in which the maximum lengths (maximum lengths 33La, 33Lb) of the axial member in the first and second directions are smaller than the maximum lengths of the multiple functional elements in the first and second directions.

[0121] (19) An endoscope described in any one of (1) to (18), The above-mentioned first lens is an endoscope, including a focus lens or a zoom lens.

[0122] (20) An endoscope as described in any one of (1) to (19), The above actuator includes a piezoelectric element (piezoelectric element 343) and a movable part (rod 342) that can move in the optical axis direction by the operation of the piezoelectric element, and moves the axial member by the movement of the movable part, in an endoscope.

[0123] (twenty one) (20) The endoscope described above, An endoscope comprising a position detection unit (magnet MG and Hall element HA) provided on the base end side of the piezoelectric element.

[0124] (twenty two) An endoscope as described in any one of (1) to (19), The actuator includes a motor and a movable part (sliding screw 340) that can move in the optical axis direction by the rotation of the motor, and moves the axial member by the movement of the movable part, in an endoscope.

[0125] (twenty three) (22) The endoscope described above, An endoscope comprising a position detection unit (magnet MG and Hall element HA) provided on the base end side of the shaft member.

[0126] (twenty four) An endoscope described in any one of (1) to (23), An endoscope in which the diameter of the tip of the insertion part is 6 mm or less.

[0127] (twenty five) An endoscope described in any one of (1) to (24), An endoscope in which the difference between the diameter of the tip of the insertion section and the diameter of the forceps channel is less than 6 mm.

[0128] (26) An endoscope described in any one of (1) to (25), In the optical axis direction described above, the proximal end of the first regulating portion is located proximal to the proximal end of the region (movement region R1) in which the first lens can move, in this endoscope.

[0129] (27) An endoscope described in any one of (1) to (26), In the optical axis direction described above, the tip of the first restricting portion is located closer to the tip than the tip of the region (movement region R1) in which the first lens can move, in this endoscope.

[0130] (28) An endoscope described in any one of (1) to (27), The first restricting portion has a first region (first region 331) located on the proximal side of the proximal end of the region (movable region R1) in which the first lens can move in the optical axis direction, and a second region (second region 332) located on the proximal side of the proximal end of the region (movable region R1) in which the first lens can move in the optical axis direction. An endoscope in which the length from the base end of the first region to the tip end of the second region (length L10) is longer than the length of the first lens in the optical axis direction (length LB).

[0131] (29) An endoscope described in any one of (1) to (28), The cross-section of the above shaft member is circular. An endoscope further comprising a second restricting part (second restricting part 322) that restricts the rotation of the shaft member of the first holding part around its axis.

[0132] (30) (29) The endoscope described above, The above-mentioned second regulating portion is provided around the region (region 320) in the first holding portion that houses the first lens, and is an endoscope.

[0133] (31) An endoscope described in any one of (1) to (30), An endoscope in which the base end face (end face 33Rr) of the shaft member and the tip end face (end face 340Fr) of the actuator are in contact.

[0134] (32) An endoscope described in any one of (1) to (31), The first direction mentioned above is the direction in which the first lens and the axial member are aligned. In the first direction described above, the distance (distance L6) between the center of gravity of the actuator (center of gravity 34C) and the optical axis is shorter than the distance (distance L7) between the center of gravity of the axial member (center of gravity 33C) and the optical axis, in this endoscope.

[0135] (33) An endoscope described in any one of (1) to (32), The first direction mentioned above is the direction in which the first lens and the axial member are aligned. In the first direction described above, one end (end E1) of the base end face (end face 33Rr) of the shaft member on the optical system side is located on the opposite side from the optical system side than one end (end E2) of the tip end face (end face 340Fr) of the actuator on the optical system side. An endoscope in which the other end (other end E3) of the base end face of the shaft member, opposite to the optical system side, is located on the opposite side from the optical system side than the other end (other end E4) of the tip end face of the actuator, opposite to the optical system side.

[0136] (34) An endoscope described in any one of (1) to (33), The first holding portion is equipped with a biasing member (spring 35, magnet MG) that biases it in the direction of the optical axis, When the position of the first lens in the optical axis direction is the first position (a position other than the base end of the movement region R1 in the front-rear direction), the base end face of the axial member and the tip end face of the actuator come into contact. An endoscope in which, when the position of the first lens in the optical axis direction is a second position different from the first position (the position of the base end of the movement region R1 in the front-rear direction), the base end face of the axial member and the tip end face of the actuator do not come into contact.

[0137] (35) (34) The endoscope described above, The actuator described above is provided on the base end side of the first holding portion, The biasing member is provided on the tip side of the first holding portion and biases the first holding portion toward the base end, in the endoscope. [Explanation of symbols]

[0138] 1 Endoscope 2 Insertion part 3 Control section 4 Universal Code 5 Soft part 6. Curved section 7 Tip 8,9 Angle knob 10 Air / Water Supply Button 12. Instrument entry port 14 Tip surface 22 Second lighting window 22A, 22B, 24A, 24B, 26A, 26B, 27A Through hole 30A, 30B, 710A, 711A Through hole 24 First lighting window 26 Forceps channel 27 Air and water supply nozzles 30 Observation window 31 Fixed lens holder 31A Objective Lens 32 Movable lens holder 32A Movable Lens 32B through hole 32L,32R,320,321,323 area 32X Engagement protrusion 33 Shaft member 33C,34C Center of gravity 33L Length 33Rr,340Fr,342Fr end face 34 Actuators 35 Compression spring 36 Prisms 36A Light entrance surface 37 Sensor 37A Photosensitive surface 38 circuit boards 39 Cables 62 Connecting member 71,71A Housing member 72 Tip cap 91 First Containment Area 92 Second Containment Area 220 Left Light Guide 240 Right Light Guide 260 Treatment tools and piping 270 Fluid line 300 imaging units 310,322A,322D protrusion 311 Through hole 322 Second Regulatory Section 322B component 322C Leaf spring 322E recess 331 First area 332 Second area 340 screws 341 Flexible shaft 342 Rods 343 Piezoelectric element 381 First substrate section 381A,382A,CP center 382 Second substrate section 710 Main Unit 710S inner surface 711,712 Extension E1,E2 One end E3, E4 other end L1,L4,L5,L6,L7 distance P1 Part 1 P2 2nd part P3 3rd part

Claims

1. The insertion part is inserted into the subject, An optical system including a first lens is positioned at the tip of the insertion portion, A sensor that captures an optical image of a subject formed by the optical system, A first holding part that holds the first lens, A shaft member fixed to the first holding portion and extending toward the base end from the first holding portion, An actuator that moves the shaft member in the optical axis direction along the optical axis of the optical system, It comprises a first restricting portion that restricts the position of the shaft member in a direction perpendicular to the optical axis, The direction perpendicular to the optical axis is a first direction and a second direction perpendicular to the first direction. The shaft member has a length in the first direction and the second direction that is shorter than the diameter of the first lens. An endoscope in which the length between the tip and base of the first restricting portion in the optical axis direction is longer than the length of the first lens in the optical axis direction.

2. The endoscope according to claim 1, An endoscope comprising a housing member having a first hole through which the optical system is inserted and a second hole through which the shaft member is inserted.

3. The endoscope according to claim 2, The first regulating portion is an endoscope provided on the inner circumference of the second hole.

4. The endoscope according to claim 2, The optical system comprises a second lens and a second holding part that holds the second lens. The second holding part is an endoscope fixed to the housing member.

5. The endoscope according to claim 1, The optical system comprises a second lens and a second holding part that holds the second lens. The endoscope has a second holding portion which is a hole that constitutes the first regulating portion through which the shaft member is inserted.

6. The endoscope according to claim 5, An endoscope comprising a housing member having a hole through which the second retaining portion is inserted.

7. The endoscope according to claim 2, The aforementioned housing member is an endoscope having a third hole through which a light guide is inserted.

8. The endoscope according to claim 1, The base end of the axial member is located on the base end side of the light-receiving surface of the sensor, in the endoscope.

9. The endoscope according to claim 8, An endoscope in which the actuator and the sensor overlap when the insertion portion is viewed from the tip side.

10. The endoscope according to claim 1, The optical system includes a prism, The base end of the aforementioned axial member is located on the base end side of the light incident surface of the prism, in the endoscope.

11. The endoscope according to claim 10, The sensor is an endoscope in which the light-receiving surface is aligned with the optical axis and the light-receiving surface is positioned opposite the light-emitting surface of the prism.

12. The endoscope according to claim 11, The first direction is the direction in which the first lens and the axial member are aligned. In the first direction, the axial member is provided on the opposite side of the optical axis from the sensor, in the endoscope.

13. The endoscope according to claim 11, The aforementioned sensor is provided on the substrate, The substrate includes a first substrate portion on which the sensor is provided, and a second substrate portion located on the proximal end side of the first substrate portion. An endoscope in which, when viewed from a direction perpendicular to the light-receiving surface of the sensor, the center of the second substrate portion in the direction along the short side of the sensor is shifted in a direction away from the shaft member and the actuator compared to the center of the first substrate portion in the direction along the short side of the sensor.

14. The endoscope according to claim 1, The tip surface of the insertion section is provided with one of the following functional elements: an observation window, a first illumination window, a second illumination window, a forceps port, or an air / water supply nozzle. When the tip surface is viewed in the direction of the optical axis, the center of the axial member is located in the region between a line that originates from the center of the tip surface and passes through the center of the observation window, and a line that originates from the center of the tip surface and passes through the center of the functional element.

15. The endoscope according to claim 14, In an endoscope, when the tip surface is viewed in the direction of the optical axis, the center of the axial member is located on the outer edge side of the tip surface, relative to the center of the observation window and the center of the functional element.

16. The endoscope according to claim 14, An endoscope in which, when the tip surface is viewed in the direction of the optical axis, the center of the axial member is located closer to the center of the tip surface than the center of the observation window and the center of the functional element.

17. An endoscope according to claim 1, wherein the tip surface of the insertion portion is provided with an observation window and a plurality of functional elements, When the tip surface is viewed in the direction of the optical axis, the center of the axis member is located on the outer edge side or the center side of the tip surface, relative to the center of the observation window and the centers of the plurality of functional elements. The aforementioned multiple functional elements are an illumination window, an observation window, a forceps channel, and an air / water supply nozzle in the endoscope.

18. The endoscope according to claim 17, An endoscope in which the maximum lengths of the axial member in the first and second directions are smaller than the maximum lengths of the plurality of functional elements in the first and second directions.

19. An endoscope according to any one of claims 1 to 18, The first lens is an endoscope, including a focus lens or a zoom lens.

20. An endoscope according to any one of claims 1 to 18, The actuator includes a piezoelectric element and a movable part that can move in the optical axis direction by the operation of the piezoelectric element, and the movement of the movable part moves the axis member, the endoscope.

21. The endoscope according to claim 20, An endoscope comprising a position detection unit provided on the base end side of the piezoelectric element.

22. An endoscope according to any one of claims 1 to 18, The actuator includes a motor and a movable part that can move in the optical axis direction by the rotation of the motor, and the movement of the movable part moves the axial member, in an endoscope.

23. The endoscope according to claim 22, An endoscope comprising a position detection unit provided on the base end side of the aforementioned shaft member.

24. An endoscope according to any one of claims 1 to 18, An endoscope in which the diameter of the tip of the insertion part is 6 mm or less.

25. An endoscope according to any one of claims 1 to 18, An endoscope in which the difference between the diameter of the tip of the insertion section and the diameter of the forceps channel is less than 6 mm.

26. An endoscope according to any one of claims 1 to 18, In the optical axis direction, the base end of the first regulating portion is located more towards the base end than the base end of the region in which the first lens can move, in an endoscope.

27. An endoscope according to any one of claims 1 to 18, In the optical axis direction, the tip of the first restricting portion is located closer to the tip than the tip of the region in which the first lens can move, in an endoscope.

28. An endoscope according to any one of claims 1 to 18, The first regulating portion has a first region located on the base side of the base end of the region in which the first lens can move in the optical axis direction, and a second region located on the tip side of the tip of the region in which the first lens can move in the optical axis direction, An endoscope in which the length from the base end of the first region to the tip of the second region is longer than the length of the first lens in the optical axis direction.

29. An endoscope according to any one of claims 1 to 18, The cross-section of the shaft member is circular. An endoscope further comprising a second restricting portion for restricting the rotation of the shaft member of the first holding portion around its axis.

30. The endoscope according to claim 29, The second regulating portion is provided around the area in the first holding portion that houses the first lens, in the endoscope.

31. An endoscope according to any one of claims 1 to 18, An endoscope in which the base end face of the shaft member and the tip end face of the actuator are in contact.

32. An endoscope according to any one of claims 1 to 18, The first direction is the direction in which the first lens and the axial member are aligned. In the first direction, the distance between the center of gravity of the actuator and the optical axis is shorter than the distance between the center of gravity of the axial member and the optical axis, in an endoscope.

33. An endoscope according to any one of claims 1 to 18, The first direction is the direction in which the first lens and the axial member are aligned. In the first direction, one end of the base end face of the shaft member on the optical system side is located on the opposite side from the optical system side to one end of the tip end face of the actuator on the optical system side. An endoscope in which the other end of the base end face of the shaft member, opposite to the optical system side, is located on the opposite side of the optical system side than the other end of the tip end face of the actuator, which is also opposite to the optical system side.

34. An endoscope according to any one of claims 1 to 18, The first holding portion is provided with a biasing member that biases it in the direction of the optical axis, When the position of the first lens in the optical axis direction is the first position, the end face on the base end of the axis member and the end face on the tip end of the actuator come into contact. An endoscope in which, when the position of the first lens in the optical axis direction is a second position different from the first position, the end face on the base end of the axial member and the end face on the tip end of the actuator do not come into contact.

35. The endoscope according to claim 34, The actuator is provided on the base end side of the first holding portion, The biasing member is provided on the tip side of the first holding portion and biases the first holding portion toward the base end, in the endoscope.

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