Endoscope and endoscope system

Abstract

An endoscope (2) in which an objective optical unit (46) having a voice coil motor (60) that moves a moving lens frame (58) in a direction of an optical axis (O) using a plurality of magnets (69f, 69r) arranged around the moving lens frame (58) and a plurality of built-in portions arranged around the objective optical unit (46) and composed of a magnetic substance are held by a distal end frame (30) constituting a distal end portion (10), at least one of the plurality of built-in portions is arranged at a position intersecting at least one of straight lines connecting a pole of a valley of a specific magnetic line of force (80) of a magnetic field formed by the plurality of magnets (69f, 69r) and two inflection points sandwiching the valley, respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to an endoscope and an endoscope system that change the optical characteristics of an objective optical system by moving a movable frame using an electromagnetic actuator. BACKGROUND

[0002] In the past, in endoscopes, an endoscope has been proposed that is capable of changing the optical characteristics of an objective optical unit provided at a distal end portion by moving a movable lens frame in and out in the optical axis direction, and has been put into practical use.

[0003] As the objective optical unit of such an endoscope, for example, an optical unit is disclosed in Japanese Patent Application Publication No. 2015-114651 that has a cylindrical fixed portion (fixed frame), a cylindrical movable frame (movable portion) disposed inside the fixed frame, and a voice coil motor that is capable of relatively moving the movable frame with respect to the fixed frame in the optical axis direction using a coil disposed in the fixed frame and a magnet disposed in the movable frame.

[0004] Here, the voice coil motor generally adjusts the disposition of each magnet and the magnetic field, etc. in the objective optical unit unit so as to be capable of causing the movable frame to properly act.

[0005] However, the distal end portion of the endoscope is required to be slim. Therefore, the magnet used by the voice coil motor is preferably a small magnet, and the magnetic force generated thereby becomes weak. Furthermore, in order to slim the distal end portion, it is necessary to dispose other built-in objects in the vicinity of the objective optical unit. Among such built-in objects, there are built-in objects composed of a magnetic substance (metal).

[0006] Furthermore, when a large number of built-in objects composed of a magnetic substance are disposed in the vicinity of the objective optical system unit, the magnetic field of the voice coil motor becomes disturbed. Such disturbance of the magnetic field of the voice coil motor can cause the movable frame to be biased in an undesirable direction, etc. and degrade the actuation performance of the movable frame. In addition, the disturbance of the magnetic field of the voice coil motor sometimes degrades the position detection accuracy of the movable frame. In such a case, it can become difficult to control the movable frame to the proper position, etc. and result in degradation of the actuation performance of the movable frame.

[0007] On the other hand, if various built-in objects composed of a magnetic substance are disposed at a position that is separated from the objective optical system unit by a distance or more, it can result in thickening of the distal end portion.

[0008] In addition, it is also considered to adjust the disposition of the magnet, the magnetic field, etc. of the voice coil motor in accordance with the layout of various built-in objects disposed in the distal end portion, but in such a case, it is necessary to make design changes to the objective optical unit depending on the type of endoscope, and the versatility of the objective optical unit is degraded, which can result in an increase in manufacturing cost.

[0009] The present application has been achieved in view of the above-described circumstances, and has an object to provide an endoscope and an endoscope system capable of securing the action performance of a movable frame by a low-cost structure without making the front end portion thick in diameter. SUMMARY

[0010] Means for solving the problem

[0011] An endoscope of one embodiment of the present application includes an objective optical unit having an actuator that moves a movable frame in the optical axis direction using a plurality of magnets, and a plurality of built-in objects disposed around the objective optical unit, which are made of a magnetic substance. At least one of the plurality of built-in objects is disposed at a position where at least a portion thereof intersects one of straight lines that connect poles of a valley of a specific equi-magnetic line of a magnetic field formed by the plurality of magnets and two inflection points sandwiching the valley.

[0012] An endoscope of another embodiment of the present application includes an objective optical unit having an actuator that moves a movable frame in the optical axis direction using a plurality of magnets, and a plurality of built-in objects disposed around the objective optical unit, which are made of a magnetic substance. At least one of the plurality of built-in objects is disposed at a position where at least a portion thereof intersects one of lines that connect valleys of equi-magnetic lines of a magnetic field formed by the plurality of magnets, in which the magnetic flux density is different.

[0013] In addition, an endoscope system of one embodiment of the present application includes the endoscope and an image processing device that converts an imaging signal obtained by imaging with the endoscope into an image signal. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 FIG. 1 is a schematic configuration diagram of an endoscope system.

[0015] Figure 2 FIG. 2 is an end surface view of a front end portion.

[0016] Figure 3 FIG. 3 is a cross-sectional view along the line III-III in FIG. 2. Figure 2

[0017] Figure 4 FIG. 4 is a cross-sectional view along the line IV-IV in FIG. 2. Figure 2

[0018] Figure 5 FIG. 5 is a cross-sectional view along the line V-V in FIG. 2. Figure 3

[0019] Figure 6 ​​​is an explanatory view showing the positional relationship of the magnetic field formed by the magnet of the voice coil motor and each of the built-in objects.

[0020] Figure 7 is an exploded perspective view of the objective optical system unit. DETAILED DESCRIPTION

[0021] Hereinafter, a mode of the present application will be described with reference to the drawings. The drawings relate to an embodiment of the present application, Figure 1 is a schematic configuration view of an endoscope system.

[0022] Figure 1 The illustrated endoscope system 1 is configured to include an endoscope 2, a control device 3, and a display device 4.

[0023] The endoscope 2 is capable of being inserted into a subject such as a human body, and optically observing a prescribed observation site in the subject. Note that the subject into which the endoscope 2 is inserted is not limited to a human body, but can be another living body, or an artificial object such as a machine or a building.

[0024] The endoscope 2 includes an insertion section 5 to be inserted into the inside of the subject, an operation section 6 connected to the proximal end side of the insertion section 5, and a general-purpose cable 7 extending from the operation section 6.

[0025] The insertion section 5 includes, in order from the distal end side toward the proximal end side, a distal end section 10, a bendable bend section 11, and a flexible tube section 12 having flexibility.

[0026] Details will be described later, but as Figure 2 shown, the distal end section 10 is provided with an imaging unit 20 for forming an image of a subject on an imaging element, a plurality of illumination optical units (for example, three illumination optical units: first to third illumination optical units 21A to 21C), a treatment instrument channel port 22, and an air / water feeding nozzle 23.

[0027] The imaging unit 20 is connected to a composite cable 25 for transmitting and receiving various signals (see Figure 1 ). In addition, as Figure 5 shown, the first to third illumination optical system units 21A to 21C are connected to first to third light guide beams 26A to 26C, respectively. In addition, the treatment instrument channel port 22 is connected to a treatment instrument channel 27. Also, the air / water feeding nozzle 23 is connected to an air / water feeding tube 28.

[0028] These composite cable 25, first to third light guide beams 26A to 26C, treatment instrument channel 27, and air / water feeding tube 28 extend to the inside of the operation section 6 via the bend section 11 and the flexible tube section 12. In addition, the respective light guide beams 26A to 26C extend to the inside of the operation section 6 as one light guide beam 26 after converging in the inside of the flexible tube section 12.

[0029] The operation section 6 is provided with a treatment instrument insertion port 6a that constitutes a base end side opening portion of the treatment instrument channel 27, an angle operation knob 6b for performing a bending operation on the bending portion 11, and a zoom lever 6c for performing a change operation on the optical characteristics of the imaging unit 20.

[0030] The composite cable 25, the light guide bundle 26, and the air / water feeding tube 28 that extend to the inside of the operation section 6 are inserted in the inside of the general cable 7. The endoscope connector 8 that is detachably connected to the control device 3 is provided at the base end portion of the general cable 7.

[0031] The endoscope connector 8 is configured to connect the composite cable 25, the light guide bundle 26, and the air / water feeding tube 28 to the control device 3.

[0032] The control device 3 has a processor such as a CPU (Central Processing Unit) that collectively controls the entire endoscope system 1. The control device 3 has an image control section 3a, a light source control section 3b, and an air / water feeding control section 3c.

[0033] The image control section 3a is electrically connected to the imaging unit 20 and the operation section 6 through the composite cable 25. The image control section 3a receives an operation signal for the zoom lever 6c to control the optical characteristics of the objective optical unit (described later) provided to the imaging unit 20. Also, the image control section 3a performs drive control on the imaging element (described later) of the imaging unit 20 to convert an imaging signal output from the imaging unit 20 into an image signal. The image converted by the image control section 3a is displayed by the display device 4 such as a monitor. Thus, in the present embodiment, the control device 3 realizes a function as an image processing device by having the image control section 3a.

[0034] The light source control section 3b is connected to a not-shown light source device built in the control device 3. Also, the light source control section 3b controls the brightness and the like of the illumination light supplied to the first to third illumination optical system units 21A to 21C through the light guide bundle 26 (first to third light guide bundles 26A to 26C) by performing drive control on the light source device.

[0035] The air / water feeding control section 3c is connected to a not-shown air / water feeding device built in the control device 3. Also, the air / water feeding control section 3c performs air feeding or water feeding to the air / water feeding nozzle 23 through the air / water feeding tube 28 by performing drive control on the air / water feeding device.

[0036] Next, the structure of the distal end portion 10 of the endoscope 2 will be described with reference to FIG. 2. Figures 2 to 7 The structure of the distal end portion 10 of the endoscope 2 will be described in detail.

[0037] The front end portion 10 has a front end frame 30 that is hard and substantially cylindrical in shape and is made of metal such as stainless steel. Here, the front end frame 30 is preferably magnetically reset by being subjected to heat treatment or the like that is known.

[0038] A front end cover 31 that forms the front end face of the front end portion 10 is adhesively fixed to the front end side of the front end frame 30. In addition, the outer periphery of the front end frame 30 is covered by an outer skin 32. Furthermore, the outer periphery of the front end side of the outer skin 32 is fixed to the front end frame by a wire wrapping adhesive portion 33.

[0039] A camera unit holding hole 30a is provided in the front end frame 30. The camera unit 20 is inserted into this camera unit holding hole 30a and is fixed by a fixing screw or the like that is not shown. The front end of the camera unit 20 is exposed to the outside of the front end cover 31, and thus an observation window 20a is formed in the front end portion 10.

[0040] In addition, as shown in Figs. 1 and 2, a plurality of illumination unit holding holes (for example, three illumination unit holding holes: first to third illumination unit holding holes 30bA to 30bC) are provided in the front end frame 30 at positions that surround the periphery of the camera unit 20. First to third illumination units 21A to 21C are inserted into these first to third illumination unit holding holes 30bA to 30bC. Figure 4 5 The first to third illumination units 21A to 21C are configured to have a metal-made substantially cylindrical illumination lens frame 35 and a plurality of lenses 36 that are held inside the illumination lens frame 35.

[0041] The front end of the first to third illumination units 21A to 21C is exposed to the outside of the front end cover 31, and thus illumination windows 21aA to 21aC are formed in the front end portion 10.

[0042] On the other hand, the front end side of first to third light guide bundles 26A to 26C, to which metal-made light guide connectors 37 are attached, are inserted inside the first to third illumination unit holding holes 30bA to 30bC on the base end side of the first to third illumination units 21A to 21C. By pressing the light guide connectors 37 against the inner walls of the first to third light guide bundles 26A to 26C with fixing screws 38, the first to third light guide bundles 26A to 26C are fixed (see Fig. 2).

[0043] By this, each of the illumination units 21A to 21C is optically connected to each of the light guide bundles 26A to 26C, and is able to irradiate the illumination light supplied from the control device 3 to the subject. Figure 5

[0044] In addition, as shown in Figs. 1 and 2, a plurality of illumination unit holding holes (for example, three illumination unit holding holes: first to third illumination unit holding holes 30bA to 30bC) are provided in the front end frame 30 at positions that surround the periphery of the camera unit 20. First to third illumination units 21A to 21C are inserted into these first to third illumination unit holding holes 30bA to 30bC. Figure 2 5 ​​​As shown, the front end frame 30 is provided with a passage through-hole 30c that opens as a passage for the treatment instrument channel 22 at the front end. A metal joint 40 is inserted in this passage through-hole 30c, and the joint 40 is connected to the front end side of the treatment instrument channel 27.

[0045] In addition, as shown in Figs. 6 and 7, a nozzle insertion hole 30d is provided on the front end frame 30 at a position that surrounds the periphery of the imaging unit 20. A metal air / water supply nozzle 23 is inserted in this nozzle insertion hole 30d. The air / water supply nozzle 23 is fixed by an adhesive or the like (not shown) in a state in which a nozzle outlet 23a provided at the front end faces the observation window 20a. On the other hand, at the base end side of the front end frame 30, the air / water supply nozzle 23 is connected to the air / water supply tube 28. Thus, the air / water supply nozzle 23 can spray air and cleaning water supplied from the control device 3 toward the observation window 20a. Figure 3 5 In addition, as shown in Figs. 6 and 7, a nozzle insertion hole 30d is provided on the front end frame 30 at a position that surrounds the periphery of the imaging unit 20. A metal air / water supply nozzle 23 is inserted in this nozzle insertion hole 30d. The air / water supply nozzle 23 is fixed by an adhesive or the like (not shown) in a state in which a nozzle outlet 23a provided at the front end faces the observation window 20a. On the other hand, at the base end side of the front end frame 30, the air / water supply nozzle 23 is connected to the air / water supply tube 28. Thus, the air / water supply nozzle 23 can spray air and cleaning water supplied from the control device 3 toward the observation window 20a.

[0046] Next, the structure of the imaging unit 20 provided at the front end portion 10 will be described.

[0047] As shown in Figs. 6 and 7, the imaging unit 20 is configured to have an imaging element unit 45 and an objective optical unit 46 connected to the front end side of the imaging element unit 45. Figures 3 to 5

[0048] The imaging element unit 45 has an imaging element holding frame 50. The front surface side of a solid-state imaging element 51 composed of a CCD, CMOS, or the like is held in the imaging element holding frame 50 via an optical member 52 such as a glass cover. In addition, the back surface side of the solid-state imaging element 51 is electrically connected to an imaging element substrate 53 on which various control circuits and the like are mounted. In addition, although not shown, the imaging element substrate 53 is electrically connected to various cables branched from the composite cable 25.

[0049] The objective optical unit 46 is configured to have a front group lens frame 55, a rear group lens frame 56, a coil holding frame 57 provided between these front group lens frame 55 and rear group lens frame 56, a moving lens frame 58 as a movable frame that is disposed inside the coil holding frame 57 in a slidable manner, and a sensor holding frame 59 that integrally holds the front group lens frame 55, rear group lens frame 56, and coil holding frame 57. Here, the objective optical unit 46 is an optical unit that can change the optical characteristics of the objective optical system by moving the moving lens frame 58 in the direction of the optical axis O to advance and retreat using a voice coil motor 60 (refer to Fig. 8) described later. Figure 7

[0050] ​​​The front group lens frame 55 is composed of a frame body in a substantially cylindrical shape. The front group lens frame 55 is formed so that the outer diameter of the front end side is larger than the outer diameter of the base end side. Further, by forming the outer diameters of the front end side and the base end side to be different diameters, a step portion 55a is formed midway through the outer peripheral surface of the front group lens frame 55. The step portion 55a is set as an abutting surface for positioning with the sensor holding frame 59.

[0051] Further, inside the front group lens frame 55, a front group lens 65 composed of a plurality of fixed lenses is held. The front group lens 65 constitutes the objective optical system of the objective optical unit 46.

[0052] The rear group lens frame 56 is composed of a frame body in a substantially cylindrical shape. The rear group lens frame 56 is formed so that the outer diameter of the front end side is smaller than the outer diameter of the base end side. Further, by forming the outer diameters of the front end side and the base end side to be different diameters, a step portion 56a is formed midway through the outer peripheral surface of the rear group lens frame 56. The step portion 56a is set as an abutting surface for positioning with the coil holding frame 57.

[0053] Further, inside the rear group lens frame 56, a rear group lens 66 composed of a plurality of fixed lenses is held. The rear group lens 66 constitutes the objective optical system of the objective optical unit 46.

[0054] The coil holding frame 57 is composed of a frame body in a substantially cylindrical shape. At every rotation position of 90° of rotation of the coil holding frame 57 about the optical axis O, a weight reduction portion 57a (refer to FIG. 6) extending in the direction of the optical axis O is formed. Figure 7 ).

[0055] Further, on the outer peripheral surface of the coil holding frame 57, two coils 67f, 67r constituting the voice coil motor 60 are arranged in the direction of the optical axis O.

[0056] The moving lens frame 58 is composed of a frame body in a substantially cylindrical shape. Inside the moving lens frame 58, a moving group lens 58a composed of one or more lenses is held. The moving group lens 58a constitutes the objective optical system of the objective optical unit 46.

[0057] Further, on the outer peripheral surface of the moving lens frame 58, a pair of recesses 68f, 68r are arranged in the direction of the optical axis O at every rotation position of 90° of rotation about the optical axis O. Two magnets 69f, 69r constituting the voice coil motor 60 are respectively held in each of the recesses 68f, 68r in a manner arranged in the direction of the optical axis O.

[0058] Each magnet 69f, 69r is arranged so that a part thereof protrudes from each recess 68f, 68r to the radially outer side of the moving lens frame 58. Further, each magnet 69f, 69r is magnetized in a manner having a polarity in the thickness direction (i.e., the radially outer side of the moving lens frame 58). Each magnet 69f, 69r in the present embodiment is arranged in the recess 68f, 68r, for example, in a manner in which the radially outer side of the moving lens frame 58 is an S pole and the radially inner side of the moving lens frame 58 is an N pole, and is fixed via an adhesive.

[0059] Here, between one group of the four groups of recesses 68f, 68r provided in the moving lens frame 58, a key 70 protruding to the radially outer side from between the pair of magnets 69f, 69r is provided. This key 70 is inserted into one of the four weight reduction portions 57a when the moving lens frame 58 is inserted into the inside of the coil holding frame 57. Thus, the rotation of the moving lens frame 58 about the optical axis O is restricted. That is, the moving lens frame 58 is housed inside the coil holding frame 57 in a state in which the rotation about the optical axis O is restricted by the key 70 and can move in the direction of the optical axis O.

[0060] The sensor holding frame 59 is composed of a frame body in a substantially cylindrical shape. An inward flange 59a is provided on the inner periphery of the front end side of this sensor holding frame 59.

[0061] Further, a sensor holding groove 75 is formed on one side of the outer peripheral portion of the sensor holding frame 59. A through hole 75a that penetrates the inside and outside of the sensor holding frame 59 is provided on a part of the front end side of this sensor holding groove 75.

[0062] A sensor substrate 76 is arranged inside the sensor holding groove 75. A Hall element 77 for detecting a magnetic field is provided on the face of the sensor substrate 76 opposite the through hole 75a. Further, the sensor substrate 76 is connected to various cables 25a branched from the composite cable 25. Also, in the sensor holding groove 75, a pressing plate 78 composed of a metal plate is provided at a position radially outward of the sensor substrate 76.

[0063] The sensor holding groove 75 in which the sensor substrate 76 and the pressing plate 78 are housed is closed by a cover 79.

[0064] The front group lens frame 55 is held on the front end side of such a sensor holding frame 59. Specifically, the front group lens frame 55 is fixed with respect to the sensor holding frame 59 in a state in which it is inserted into the inside of the sensor holding frame 59 by adhesion or the like. At this time, the stepped portion 55a of the front group lens frame 55 abuts against the front end face of the inward flange 59a of the sensor holding frame 59 via an adhesive or the like not shown. Thus, the positioning of the front group lens frame 55 with respect to the sensor holding frame 59 in the direction of the optical axis O is completed.

[0065] In addition, the coil holding frame 57 is held inside the sensor holding frame 59. Specifically, the coil holding frame 57 is fixed by adhesion or the like in a state where the front end surface abuts against the base end surface of the inward flange 59a of the sensor holding frame 59.

[0066] At this time, the coil holding frame 57 is positioned around the optical axis O in a manner that one set of the magnets 69f, 69r among the multiple sets (four sets in the present embodiment) of the magnets 69f, 69r housed on the moving lens frame 58 is opposed to the Hall element 75. Thereby, the Hall element 75 is able to detect the position of the moving lens frame 58 in the direction of the optical axis O in accordance with the change in the magnetic field received from the one set of the magnets 69f, 69r. In addition, by pulling the one set of the magnets 69f, 69r toward the urging plate 78, the wobble of the moving lens frame 58 inside the coil holding frame 57 is suppressed. Thereby, stable sliding performance of the moving lens frame 58 and stable optical characteristics of the objective optical system are realized.

[0067] In addition, the rear group lens frame 56 is held inside the sensor holding frame 59 at a position on the base end side from the coil holding frame 57. Specifically, the rear group lens frame 56 is fixed by an adhesive or the like in a state where the front end side is inserted inside the coil holding frame 57 and the base end side is inserted inside the sensor holding frame 59. At this time, the rear group lens frame 56 is positioned in the direction of the optical axis O with respect to the coil holding frame 57 by abutting the stepped portion against the base end surface of the coil holding frame 57.

[0068] The front end side of the imaging element holding frame 50 is connected to the base end side of the rear group lens frame 56 held in the sensor holding frame 59. Thereby, the object image is formed on the solid-state imaging element 51 by the objective optical system of the objective optical unit 46.

[0069] In the thus configured endoscope system 1, when the zoom lever 6c of the endoscope 2 is operated by a user or the like, the image control section 3a of the control device 3 performs energization control of the coils 67f, 67r in accordance with the operation state of the zoom lever 6c. The magnets 69f, 69r move the moving lens frame 58 in the direction of the optical axis O in response to the magnetic field generated in the coils 67f, 67r by the energization control. At this time, the Hall element 77 detects the change in the magnetic field accompanying the movement of the magnets 69f, 69r in the direction of the optical axis O, and outputs the detected change in the magnetic field as a feedback signal to the image control section 3a. Thereby, the energization of the coils 67f, 67r is feedback-controlled, and the moving lens frame 58 is controlled to a position on the optical axis O corresponding to the operation state of the zoom lever 6c.

[0070] In addition, as Figure 6As shown, the objective optical unit 46 of the imaging unit 20 forms a magnetic field around the objective optical unit 46 using four magnets 69f, 69r. In addition, Figure 6 The isomagnetic line of the magnetic field shown indicates the distribution of the magnetic field of the objective optical unit 46 alone before the objective optical unit 46 is assembled to the front end frame 30.

[0071] In order to avoid the magnetic field from changing due to the influence of other metals (magnetic bodies), the various built-in objects provided to the front end portion 10 are provided to positions in the vicinity of the imaging unit 20 where the influence on the magnetic field formed by the respective magnets 69f, 69r is small.

[0072] Specifically, for example, as shown in Figure 6 The various built-in objects composed of magnetic bodies are configured so as not to substantially enter the inside of a specific isomagnetic line 80 (in the present embodiment, for example, 100 (mT)) as a standard. Here, the specific isomagnetic line 80 is a lower limit value of the isomagnetic line that is considered to be able to affect the performance of the action of the voice coil motor 60. This lower limit value is appropriately determined based on experiments, simulations, or the like in accordance with the kind of the objective optical system unit 46 or the like. Furthermore, even in the case where the built-in object enters the inside of the specific isomagnetic line 80, a slight amount of entry to the extent that the amount of entry does not affect the magnetic field can be permitted.

[0073] In order to bring the various built-in objects in the vicinity of the imaging unit 20 while satisfying such conditions, it is preferable that at least a part of at least one of the various built-in objects be provided on a line (first to fourth lines 83a to 83d) that links the poles of the valleys of the isomagnetic lines in which the magnetic flux density is different. Alternatively, it is preferable that at least one of the various built-in objects be provided at a position that intersects at least one of the straight lines (first to eighth straight lines 84a to 84h) that link the poles 81a to 81d of the valleys of the specific isomagnetic line 80 and the two inflection points 82a to 82h sandwiching each valley. That is, by being provided so as to satisfy at least one of such conditions, it is possible to provide at least one of the various built-in objects along the valley of the specific isomagnetic line 80, and it is possible to provide the various built-in objects in the vicinity of the objective optical unit 46 as much as possible while excluding the influence on the magnetic field.

[0074] Here, the pole of the valley portion of each magnetic line refers to the pole of the portion of the magnetic line that protrudes toward between the adjacent magnets 69f, 69r. Further, the first to fourth lines 83a to 83d that connect the poles of the valley portions of the magnetic lines can be an approximate straight line or a spline curve. In the mobile lens frame 58 of the present embodiment, four sets of magnets 69f, 69r are arranged on the outer periphery, and thus the valley portions of the magnetic lines are formed at four places, respectively. Therefore, the first to fourth lines 83a to 83d that connect the valley portions of the magnetic lines are set around the objective optical unit 46. Further, the first to eighth straight lines 84a to 84h that connect the valley portion of the specific magnetic line 80 and each inflection point are set.

[0075] In the present embodiment, the first illumination optical unit 21A is arranged at least in a portion of the position that intersects the first line 83a. Further, the first illumination optical unit 21A is arranged so that at least a portion thereof is positioned at a position that intersects the first straight line 84a, and a majority (for example, more than half of the cross-sectional area) thereof is positioned in the region sandwiched by the two straight lines defined by the same pole (pole 81a). By satisfying these conditions, the first illumination optical unit 21A is arranged along the valley portion of the specific magnetic line 80.

[0076] By such an arrangement, the illumination lens frame 35, the light guide joint 37, and the fixing screw 38, which are various components (built-in objects) composed of a magnetic material associated with the first illumination optical unit 21A, are arranged in a state where they do not need to be substantially arranged inside the specific magnetic line 80, and approach the objective optical unit 46 (imaging unit 20).

[0077] Further, in the present embodiment, a portion of the illumination lens frame 35 and the light guide joint 37 of the first illumination optical unit 21A intersects the specific magnetic line 80. However, the amount (cross-sectional area) by which these illumination lens frame 35 and light guide joint 37 enter inside the specific magnetic line 80 is a small amount that does not cause a large impact on the magnetic field.

[0078] Here, regarding the area Sa in which the built-in object composed of a magnetic material enters inside the specific magnetic line 80, it is preferable that the evaluation value E indicated by the following formula (1) is smaller than the threshold value Eth of the evaluation value in the entire region in the optical axis O direction.

[0079] E = (Sa / S) x P... (1)

[0080] Further, in formula (1), S indicates the cross-sectional area of the built-in object composed of a magnetic material, and P indicates the magnetic permeability of the built-in object composed of a magnetic material.

[0081] By so configuring, it is possible to dispose a part of the built-in object inside the specific magnetic line 80 without causing a large influence on the magnetic field of the voice coil motor 60. Further, the threshold value Eth is a value that is obtained in advance based on experiments, simulations, or the like.

[0082] The second illumination optical unit 21B is disposed at least in part at a position intersecting the second line 83b. By satisfying this condition, the second illumination optical unit 21B is disposed along the valley of the specific magnetic line 80.

[0083] By so configuring, the illumination lens frame 35, the light guide joint 37, and the fixing screw 38, which are various components (built-in objects) composed of a magnetic body in association with the second illumination optical unit 21B, are disposed in a state of approaching the objective optical unit 46 (imaging unit 20) without being disposed inside the specific magnetic line 80.

[0084] The third illumination optical unit 21C is disposed at least in part at a position intersecting the third line 83c. By satisfying this condition, the third illumination optical unit 21C is disposed along the valley of the specific magnetic line 80.

[0085] By so configuring, the illumination lens frame 35, the light guide joint 37, and the fixing screw 38, which are various components (built-in objects) composed of a magnetic body in association with the third illumination optical unit 21C, are disposed in a state of approaching the objective optical unit 46 (imaging unit 20) without being disposed inside the specific magnetic line 80.

[0086] Further, the air / water feeding nozzle 23 is disposed at least in part at a position intersecting the second straight line 84b and a majority thereof is disposed in a region sandwiched by two straight lines defined by the same pole point (pole point 81a). By satisfying these conditions, the air / water feeding nozzle 23 is disposed along the valley of the specific magnetic line 80.

[0087] Further, in the example shown in FIG. 8, the air / water feeding nozzle 23 is disposed at least in part at a position intersecting the second straight line 84b and a majority thereof is disposed in a region sandwiched by two straight lines defined by the same pole point (pole point 81a). By satisfying these conditions, the air / water feeding nozzle 23 is disposed along the valley of the specific magnetic line 80. Figure 6 In the example shown in FIG. 8, as to the treatment instrument channel port 22, the layout is separated from the objective optical unit 46. Therefore, it is not particularly required to satisfy the above conditions, but in a case where it is required to dispose them in the vicinity of the objective optical system unit 46, it is preferable to dispose at least in part at a position intersecting the first to fourth straight lines 84a to 84d.

[0088] According to such an embodiment, the endoscope 2, in the distal end section 10 constituted by the distal end frame 30, holds the objective optical unit 46 having the voice coil motor 60 that moves the movable lens frame 58 in the optical axis O direction using a plurality of magnets 69f, 69r arranged around the movable lens frame 58, and a plurality of built-in sections arranged around the objective optical unit 46, constituted by a magnetic substance, at least one of the plurality of built-in sections being arranged at a position where at least a portion thereof intersects any one of the first to fourth lines 83a to 83d that are lines linking poles of the equal magnetic lines of magnetic field formed by the plurality of magnets 69f, 69r, and thus, without thickening the distal end section 10, it is possible to secure the performance of the movable lens frame 58 by a low-cost structure.

[0089] That is, by arranging at least one of the plurality of built-in sections at a position where at least a portion thereof intersects any one of the first to fourth lines 83a to 83d that link poles of the valley portions of the specific equal magnetic lines 80, it is possible to efficiently arrange the built-in section along the valley portion of the specific equal magnetic line 80. Thus, it is possible to arrange the built-in section in the vicinity of the objective optical unit 46 while suppressing the influence of the built-in section on the magnetic field, and it is possible to suppress thickening of the distal end section 10. Also, since the built-in section is arranged without influencing the magnetic field, it is not necessary to change the design of the arrangement of the magnets 69f, 69r of the voice coil motor 60 provided to the objective optical unit 46 and the magnetic field according to the type of the endoscope 2, etc. Thus, it is possible to secure the performance of the movable lens frame 58 by a low-cost structure.

[0090] In addition, by arranging at least one of the plurality of built-in sections at a position where at least a portion thereof intersects any one of the first to eighth straight lines 84a to 84h that respectively link the poles 81a to 81d of the valley portions of the specific equal magnetic lines 80 and each two inflection points 82a to 82h sandwiching the valley portions, even in this case, it is possible to efficiently arrange the built-in section along the valley portion of the specific equal magnetic line 80.

[0091] Furthermore, the present application is not limited to the above-described embodiments, and various modifications and changes can be made, which are also within the technical scope of the present application.

[0092] For example, in the above-described embodiments, the structure in which all of the three illumination optical units 21A to 21C are arranged at positions intersecting any one of the first to fourth lines 83a to 83d was described, but the present application is not limited thereto, and it is also possible to arrange one or two of the illumination optical units at positions intersecting any one of the first to fourth lines 83a to 83d depending on the layout on the distal end section 10.

[0093] In addition, the number of illumination optical units arranged in the front end portion 10 is not limited to three, and can be one or two illumination optical units, and can also be four or more illumination optical units.

[0094] In addition, in the above-described embodiment, an example in which the illumination optical unit is arranged at a position intersecting any one of the first to fourth lines 83a to 83d is described, but for example, other built-in objects such as the treatment instrument passage port 22, the air / water feeding nozzle 23, and the like can be arranged at a position intersecting any one of the first to fourth lines 83a to 83d.

[0095] In addition, the number of magnets constituting the voice coil motor 60 is of course not limited to the above-described embodiment.

Claims

1. An endoscope, wherein an objective lens optical unit is held in the front end frame constituting the front end portion of the insertion section, characterized in that, The objective lens optical unit has: lens; A lens frame that holds the lens; An actuator, comprising multiple magnets and a coil, moves the lens frame in the direction of the optical axis. A plurality of built-in elements are arranged around the objective lens optical unit. The plurality of built-in elements are made of magnetic materials, and at least one of the plurality of built-in elements is arranged at a position where at least a portion intersects one of the following straight lines, which are the poles of the valleys of specific isomagnetic lines of the magnetic field formed by the plurality of magnets and the straight lines that sandwich the two inflection points of the valleys.

2. The endoscope according to claim 1, characterized in that, At least one of the plurality of built-in elements is configured at a position where at least a portion intersects one of the following lines, which are lines connecting the poles of the valleys of isomagnetic lines with different magnetic flux densities in the magnetic field formed by the plurality of magnets.

3. The endoscope according to claim 1, characterized in that, The built-in components are an illumination optics unit and components associated with the illumination optics unit.

4. The endoscope according to claim 1, characterized in that, The built-in components are air and water delivery nozzles and components associated with the air and water delivery nozzles.

5. The endoscope according to claim 1, characterized in that, The built-in components are the treatment device access port and the components associated with the treatment device access port.

6. An endoscope, wherein an objective lens optical unit is held in the front end frame constituting the front end portion of the insertion section, characterized in that, The objective lens optical unit has: lens; A lens frame that holds the lens; An actuator, connected to the lens frame, includes multiple magnets and a coil, to move the lens frame along the optical axis. A plurality of built-in elements are arranged around the objective lens optical unit. The plurality of built-in elements are made of magnetic materials, and at least one of the plurality of built-in elements is arranged at a position where at least a portion intersects one of the following straight lines, which are lines connecting the poles of the valleys of the magnetic flux densities of the magnetic fields formed by the plurality of magnets.

7. The endoscope according to claim 6, characterized in that, The built-in components are an illumination optics unit and components associated with the illumination optics unit.

8. The endoscope according to claim 6, characterized in that, The built-in components are air and water delivery nozzles and components associated with the air and water delivery nozzles.

9. The endoscope according to claim 6, characterized in that, The built-in components are the treatment device access port and the components associated with the treatment device access port.

10. An endoscope system, characterized in that, have: The endoscope as claimed in claim 1; and An image processing device that converts the camera signal obtained by the endoscope into an image signal.

11. An endoscope system, characterized in that, have: The endoscope as claimed in claim 6; and An image processing device that converts the camera signal obtained by the endoscope into an image signal.

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