Endoscope and endoscope system

Abstract

To provide an endoscope and endoscope system that can efficiently remove the dirt of an auxiliary light-emitting window.SOLUTION: A distal end part 12d of an insertion part of an endoscope is provided with a distal end surface 56, an objective lens 21, an air / water supply nozzle 25 that jets fluid toward the objective lens 21, two illumination lenses 22, and a measurement auxiliary light lens 23 for emitting measurement auxiliary light. The objective lens 21 is disposed between two illumination lenses 22, and emits measurement auxiliary light in a state where the optical axis of the measurement auxiliary light crosses the optical axis of the objective lens 21. The measurement auxiliary light lens 23 is disposed within a fluid ejection range of the air / water supply nozzle 25 and between the objective lens 21 and the air / water supply nozzle 25.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an endoscope that emits auxiliary measurement light and an endoscope system. [Background technology]

[0002] In the field of endoscopy, it is common to obtain the distance to an observation object or the size of the observation object. For example, in Patent Document 1, an auxiliary measurement light is irradiated onto the object from an auxiliary light irradiation window provided at the tip of the endoscope, forming a spot on the object. As a result, an endoscope processor identifies the position of the spot from an image obtained by capturing an image of the object. The observation distance is then detected from the position of the spot.

[0003] Meanwhile, the tip of the endoscope is equipped with an observation window, an illumination window, a fluid ejection nozzle, and the like in addition to the auxiliary light ejection window. The fluid ejection nozzle ejects a fluid such as cleaning water to clean the observation window. In the endoscope described in Patent Document 2, the illumination window is disposed within the ejection range of the fluid ejection nozzle, and the cleaning water ejected from the fluid ejection nozzle is sprayed onto the surface of the illumination window. This allows heat generated by light irradiation from the illumination window to be dissipated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 051680 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-39462 Summary of the Invention [Problem to be solved by the invention]

[0005] Because the tip of an endoscope becomes soiled with body fluids and the like, it is desirable to clean the auxiliary light emission window as well as the observation window. However, in Patent Document 2, cleaning water is sprayed onto the illumination window to dissipate heat, and cleaning of the illumination window is not taken into consideration. Therefore, even if an auxiliary light emission window is provided instead of the illumination window in a configuration similar to Patent Document 2, cleaning of the auxiliary light emission window cannot be accommodated, and dirt removal is insufficient.

[0006] The present invention has been made in view of the above circumstances, and has as its object to provide an endoscope and an endoscope system that can efficiently remove dirt from an auxiliary light emission window. [Means for solving the problem]

[0007] The endoscope of the present invention comprises an insertion section, a tip surface, an observation window, a fluid ejection nozzle, two illumination lenses, and an auxiliary light emission window, wherein the observation window is disposed between the two illumination lenses, and the auxiliary light emission window is disposed within the fluid ejection range of the fluid ejection nozzle and between the observation window and the fluid ejection nozzle, and emits auxiliary measurement light to a specific region of the subject with the optical axis of the auxiliary measurement light intersecting the optical axis of the observation window. The insertion section is inserted into a subject. The tip surface is provided at the tip of the insertion section. The observation window is disposed on the tip surface. The fluid ejection nozzle is disposed on the tip surface and ejects fluid toward the observation window. The auxiliary light emission window is disposed on the tip surface and emits auxiliary measurement light used for measuring the subject. The two illumination lenses are disposed on the tip surface and are for irradiating illumination light onto the subject.

[0008] It is preferable that the opening width of the fluid ejection nozzle is smaller than the outer diameter of the observation window, and that the outer diameter of the auxiliary light irradiation window is smaller than the opening width of the fluid ejection nozzle.It is preferable that the auxiliary light irradiation window is disposed within a region connecting the ejection port of the fluid ejection nozzle and the outer peripheral edge of the observation window, and that the illumination lens is disposed outside this region.

[0009] The tip surfaces of the observation window and the illumination lens are preferably located at an attachment position relative to the tip surface of the fluid ejection nozzle and at the tip side in the axial direction relative to the tip surface of the auxiliary light irradiation window, and have a guide surface that continues from the outer peripheral edge of the auxiliary light irradiation window to the outer peripheral edge of the observation window.

[0010] It is preferable that the opening width of the fluid ejection nozzle is smaller than the outer diameter of the observation window, and the guide surface is located within the fluid ejection range of the fluid ejection nozzle.

[0011] The fluid ejection nozzle ejects a liquid or gas as the fluid, and when the liquid or gas is ejected from the fluid ejection nozzle toward the observation window, it is preferable that the flow velocity of the liquid at the position where it reaches the observation window is 2 m / s or more, and the flow velocity of the gas at the position where it reaches the observation window is 40 m / s or more.

[0012] It is preferable that the outer diameter of the auxiliary light irradiation window is 0.5 mm or more and 1.6 mm or less, the first minimum distance which is the smallest distance between the outer peripheral edge of the observation window and the outer peripheral edge of the auxiliary light irradiation window is 0 mm or more and 1.5 mm or less, and the second minimum distance which is the smallest distance between the outer peripheral edge of the auxiliary light irradiation window and the tip of the fluid ejection nozzle is 0 mm or more and 0.5 mm or less.

[0013] An endoscope system of the present invention includes the above-described endoscope, a light source device, and a processor device. [Effects of the Invention]

[0014] According to the present invention, dirt on the auxiliary light emission window can be removed efficiently. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an external view of an endoscope system. [Figure 2] FIG. 2 is a plan view showing the tip portion of the endoscope. [Figure 3] FIG. 2 is a block diagram showing the functions of the endoscope system. [Figure 4] FIG. 4 is a schematic diagram showing the configuration of a measurement assist light emitting unit. [Figure 5] FIG. 2 is an explanatory diagram showing a state in which an insertion portion of an endoscope is inserted into a subject. [Figure 6] 1 is an explanatory diagram showing the relationship between the tip of the endoscope and the near end PN, the central area PM, and the far end PF within the observation distance range R1. [Figure 7] FIG. 2 is a cross-sectional view of the tip of the endoscope. [Figure 8] FIG. 2 is a perspective view of the tip of the endoscope. [Figure 9] FIG. 2 is a cross-sectional view of the main part of the tip of the endoscope. [Figure 10] FIG. 2 is a plan view of the distal end of the endoscope, showing the dimensional relationship between an auxiliary light irradiation window, an observation window, and a fluid ejection nozzle. [Figure 11] FIG. 2 is a plan view of the distal end of the endoscope, showing a state in which fluid ejected from a fluid ejection nozzle is diffused on a guide surface. [Figure 12] FIG. 10 is a plan view showing the tip of an endoscope without a guide surface as a comparative example. [Figure 13] FIG. 10 is a cross-sectional view of the tip portion of the endoscope according to the second embodiment. [Figure 14] FIG. 10 is a perspective view showing the positional relationship between a fluid ejection nozzle and an auxiliary light irradiation window in a second embodiment. [Figure 15] FIG. 10 is an exploded perspective view of the distal end portion of the endoscope according to the second embodiment. [Figure 16] FIG. 11 is a perspective view showing the positional relationship between a fluid ejection nozzle and an auxiliary light irradiation window in a modified example of the second embodiment. [Figure 17] FIG. 10 is a cross-sectional view of the tip portion of the endoscope according to the third embodiment. [Figure 18] FIG. 11 is a perspective view showing the positional relationship between the tip cap and the auxiliary light emission window in the third embodiment. [Figure 19] 10 is an image diagram showing a spot and a first measurement marker when the observation distance is near end PN. FIG. [Figure 20] 10 is an image diagram showing the spot and the first measurement marker when the observation distance is near the center PM. FIG. [Figure 21]10 is an image diagram showing a spot and a first measurement marker when the observation distance is the far end PF. FIG. [Figure 22] FIG. 10 is an image diagram of an example of a measurement image in which a measurement marker is superimposed on a subject image. [Figure 23] FIG. 10 is an image diagram of an example of a measurement image in which a measurement marker is superimposed on a subject image. [Figure 24] FIG. 10 is an image diagram of an example of a measurement image in which a measurement marker is superimposed on a subject image. [Figure 25] An explanatory diagram showing the types of measurement markers, where Figure 25(A) is a measurement marker with a line segment and scale to the left of the spot SP, Figure 25(B) is a measurement marker with a line segment and scale to the bottom of the spot SP, and Figure 25(C) is a measurement marker with a line segment and scale to the top right of the spot SP. [Figure 26] 10A to 10C are explanatory diagrams showing first measurement markers of a cross type, a graduated cross type, a distorted cross type, a circle and cross type, and a measurement point cloud type. [Figure 27] FIG. 1 is an image showing three concentric markers, each of the same color. [Figure 28] FIG. 10 is an image diagram showing three concentric markers of different colors. [Figure 29] FIG. 10 is an image diagram showing a distorted concentric circle marker. [Figure 30] 10A and 10B are explanatory diagrams showing a light emission pattern for intermittently irradiating spotlight. [Figure 31] FIG. 10 is an image showing the intersecting lines and scales. [Figure 32] 10A and 10B are explanatory diagrams showing a light emission pattern for intermittently irradiating line-shaped measurement light. [Figure 33] FIG. 10 is an explanatory diagram showing a stripe pattern light ZPL. [Figure 34] 10 is an explanatory diagram showing an emission pattern of striped pattern light ZPL of phases X, Y, and Z. FIG. [Figure 35] FIG. 10 is an explanatory diagram showing a measuring light LPL having a grid pattern. [Figure 36] 10A and 10B are explanatory diagrams showing a light emission pattern for intermittently irradiating measurement light in a grid pattern. [Figure 37] FIG. 1 is an explanatory diagram showing three-dimensional planar light TPL. [Figure 38] 10A and 10B are explanatory diagrams showing a light emission pattern for intermittently emitting three-dimensional planar light. DETAILED DESCRIPTION OF THE INVENTION

[0016] [First embodiment] 1, the endoscope system 10 includes an endoscope 12, a light source device 14, a processor device 16, a monitor 18, and a user interface 19. The endoscope 12 is optically connected to the light source device 14 and electrically connected to the processor device 16. The processor device 16 is electrically connected to a monitor 18 (display unit) that displays an image. The user interface 19 is connected to the processor device 16 and is used for various setting operations for the processor device 16. The user interface 19 includes a mouse and the like in addition to the keyboard shown in the figure.

[0017] The endoscope 12 has an insertion section 12a that is inserted into the subject, an operation section 12b provided at the base end of the insertion section 12a, and a bending section 12c and a tip section 12d provided at the tip end of the insertion section 12a. The bending section 12c is bent by operating an angle knob 12e of the operation section 12b. As a result of this bending, the tip section 12d is directed in a desired direction.

[0018] The endoscope 12 has a normal mode and a length measurement mode, and these two modes can be switched by a mode selector switch 13a provided on the operation unit 12b of the endoscope 12. The normal mode is a mode in which the observation object is illuminated with illumination light. The length measurement mode is a mode in which the observation object is illuminated with illumination light or auxiliary measurement light, and a measurement marker used to measure the size of the observation object is displayed on an image obtained by imaging the observation object. The auxiliary measurement light is light used to measure the subject.

[0019] The operation section 12b of the endoscope 12 is also provided with a freeze switch 13b (still image acquisition instruction section) for operating a still image acquisition instruction that instructs acquisition of a still image of the captured image. When the user operates the freeze switch 13b, the screen of the monitor 18 is frozen and an alert sound (e.g., a beep) is emitted to indicate that a still image will be acquired. Then, still images of the captured images obtained around the time of operating the freeze switch 13b are stored in the still image storage section 42 (see FIG. 3) in the processor device 16.

[0020] The still image storage unit 42 is a storage unit such as a hard disk, a USB (Universal Serial Bus) memory, etc. If the processor device 16 can be connected to a network, the still images of the captured images may be stored in a still image storage server (not shown) connected to the network instead of or in addition to the still image storage unit 42.

[0021] Note that a still image acquisition instruction may be issued using an operating device other than the freeze switch 13b. For example, a foot pedal may be connected to the processor device 16, and a still image acquisition instruction may be issued when the user operates the foot pedal (not shown) with his or her foot. Mode switching may also be performed using the foot pedal. Furthermore, a still image acquisition instruction or mode switching may be performed using voice input, eye-gaze input, gesture input, or the like.

[0022] As shown in FIG. 2, the tip of the endoscope 12 is approximately circular and includes an objective lens 21 located closest to the subject among the optical members constituting the imaging optical system 29b (see FIG. 7) of the endoscope 12, two illumination lenses 22 for irradiating the subject with illumination light, an auxiliary measurement light lens 23 for illuminating the subject with auxiliary measurement light, which will be described later, a treatment tool outlet 24 for projecting a treatment tool toward the subject, and an air and water nozzle 25 for supplying air and water. The objective lens 21 constitutes the observation window in the claims. The air and water nozzle 25 corresponds to the fluid injection nozzle in the claims. The liquid supplied by the air and water nozzle 25 is cleansing water, and the gas supplied is air or carbon dioxide.

[0023] The optical axis LI (see FIG. 6) of the objective lens 21 extends in a direction perpendicular to the paper surface. A first vertical direction D1 is perpendicular to the optical axis LI, and a second horizontal direction D2 is perpendicular to the optical axis LI and the first direction D1.

[0024] As shown in FIG. 3, the light source device 14 includes a light source unit 26 and a light source control unit 27. The light source unit 26 (illumination light source unit) generates illumination light for illuminating the subject. The illumination light emitted from the light source unit 26 enters a light guide 28 and passes through an illumination lens 22 to be irradiated onto the subject. The light source unit 26 preferably uses a white light source that emits white light, or a plurality of light sources including a white light source and a light source that emits light of another color (e.g., a blue light source that emits blue light). The light source control unit 27 is connected to a system control unit 41 of the processor device 16. The light source control unit 27 controls the light source unit 26 based on instructions from the system control unit 41. The system control unit 41 (light emission control unit) not only issues instructions regarding light source control to the light source control unit 27, but also controls the light source 30a (see FIG. 4) of the measurement assist light emitting unit 30. Details of light source control by the system control unit 41 will be described later.

[0025] The tip 12d of the endoscope 12 is provided with an illumination optical system 29a, an imaging optical system 29b, and an auxiliary measurement light emitting unit 30. The illumination optical system 29a has an illumination lens 22, and light from a light guide 28 is irradiated onto the observation object via the illumination lens 22. The imaging optical system 29b has an objective lens 21 and an imaging element 32. Reflected light from the observation object is incident on the imaging element 32 via the objective lens 21. As a result, a reflected image of the observation object is formed on the imaging element 32.

[0026] The imaging element 32 is a color imaging sensor that captures a reflected image of the subject and outputs an image signal. The imaging element 32 is preferably a CCD (Charge Coupled Device) imaging sensor or a CMOS (Complementary Metal-Oxide Semiconductor) imaging sensor. The imaging element 32 used in the present invention is a color imaging sensor that obtains RGB image signals of three colors: R (red), G (green), and B (blue). The imaging element 32 is controlled by an imaging control unit 33. Note that the imaging element 32 may also be a complementary color imaging element provided with color filters of complementary colors: C (cyan), M (magenta), Y (yellow), and G (green).

[0027] The image signal output from the imaging element 32 is transmitted to a CDS / AGC circuit 34. The CDS / AGC circuit 34 performs correlated double sampling (CDS) and automatic gain control (AGC) on the analog image signal. The image signal that has passed through the CDS / AGC circuit 34 is converted into a digital image signal by an A / D (Analog / Digital) converter 35. The A / D converted digital image signal is input to the processor device 16 via a communication I / F (Interface) 36.

[0028] The processor device 16 includes a communication I / F (Interface) 38 connected to the communication I / F 36 of the endoscope 12, a signal processing unit 39, a display control unit 40, and a system control unit 41. The communication I / F 38 receives image signals transmitted from the communication I / F 36 of the endoscope 12 and transmits them to the signal processing unit 39. The signal processing unit 39 has a built-in memory that temporarily stores the image signals received from the communication I / F 38, and processes a group of image signals that are a collection of image signals stored in the memory to generate a captured image.

[0029] The signal processing unit 39 acquires an image captured by the endoscope. When the signal processing unit 39 is set to the length measurement mode, the captured image may be subjected to structure enhancement processing that enhances structures such as blood vessels, or color difference enhancement processing that expands the color difference between normal and diseased areas of the object of observation.

[0030] The display control unit 40 displays the captured image generated by the signal processing unit 39 on the monitor 18. The system control unit 41 controls the image sensor 32 via the imaging control unit 33 provided in the endoscope 12. The imaging control unit 33 also controls the CDS / AGC circuit 34 and the A / D converter 35 in accordance with the control of the image sensor 32. The still image saving control unit 43 controls the still images of the captured images to be saved in the still image saving unit 42. The still image saving control unit 43 performs control described below in response to a single still image acquisition instruction being given in the length measurement mode.

[0031] As shown in FIG. 4, the auxiliary measurement light emitting unit 30 (auxiliary measurement light source unit) includes a light source 30a, a GRIN (Gradient Index) lens 30b, a prism 30c, an optical fiber 30d, and the auxiliary measurement light lens 23. The light source 30a emits light (specifically, visible light) of a color detectable by the pixels of the imaging element 32. The light source 30a includes a light-emitting element such as a laser light source LD (Laser Diode) or LED (Light Emitting Diode), and a condenser lens that condenses the light emitted from the light-emitting element. The auxiliary measurement light lens 23 constitutes the auxiliary light emitting window and the optical member for the auxiliary light emitting window in the claims. The auxiliary measurement light lens 23 is formed in a cylindrical shape. When incorporated into the distal end portion 12d, the distal end surface 23a is a plane perpendicular to the axial direction Z of the insertion portion 12a, and the proximal end surface 23b is a plane that intersects the axial direction Z and is aligned with the distal end surface of the prism 30c.

[0032] The wavelength of the light emitted by the light source 30a is preferably, for example, 600 nm to 750 nm, more preferably 600 nm to 700 nm, and most preferably red light of 630 nm to 660 nm. Alternatively, green light of 495 nm to 570 nm may be used. The light source 30a is controlled by the system control unit 41 and emits light based on instructions from the system control unit 41.

[0033] The base end side (light source 30a side) of the optical fiber 30d is covered with a fiber jacket 30e, and the tip end side (the side that emits the laser light) is inserted into a ferrule 30f and bonded with an adhesive, and the end face is polished.

[0034] A GRIN lens 30b is attached to the tip of the ferrule 30f, and a prism 30c is attached to the tip of the GRIN lens 30b to form a joint. The ferrule 30f is a member for holding and connecting the optical fiber 30d, and a hole for inserting the optical fiber 30d is formed in the center in the axial direction (left and right direction in Figure 4).

[0035] A reinforcing member 30g is provided on the outside of the ferrule 30f and the fiber jacket 30e to protect the optical fiber 30d and the like. The auxiliary measurement light lens 23, the GRIN lens 30b, and the prism 30c are housed in a housing 30h. The housing 30h is joined to the reinforcing member 30g. As a result, the auxiliary measurement light lens 23, the GRIN lens 30b, the prism 30c, and the optical fiber 30d are held together within the reinforcing member 30g and the housing 30h.

[0036] The optical fiber 30d guides the light from the light source 30a to the GRIN lens 30b. The GRIN lens 30b converts the light guided from the light source 30a by the optical fiber 30d back into highly coherent light in order to convert the light emitted from the light source 30a into auxiliary measurement light used in measuring the subject.

[0037] The prism 30c is an optical element for changing the traveling direction of the fill-in measurement light after being converted by the GRIN lens 30b. The prism 30c changes the traveling direction of the fill-in measurement light so that it intersects with the field of view of the imaging optical system 29b, which includes the objective lens 21 and a group of lenses. The traveling direction of the fill-in measurement light will also be described in detail later. The fill-in measurement light emitted from the prism 30c passes through the fill-in measurement light lens 23 and is irradiated onto the subject. As shown in FIG. 5, when the fill-in measurement light is irradiated onto the subject H, a spot SP is formed on the subject as a circular area (specific area).

[0038] Note that an auxiliary measurement slit formed in the tip 12d of the endoscope may be used instead of the auxiliary measurement light lens 23. It is also preferable to apply an anti-reflection coating (AR (Anti-Reflection) coating) (anti-reflection portion) to the auxiliary measurement light lens 23. The reason for providing an anti-reflection coating in this manner is that if the auxiliary measurement light is reflected without passing through the auxiliary measurement light lens 23, reducing the proportion of the auxiliary measurement light that is irradiated onto the subject, it becomes difficult for the signal processing unit 39 to recognize the position of the spot SP formed on the subject by the auxiliary measurement light.

[0039] The measurement assist light emitting unit 30 may be any unit capable of emitting measurement assist light toward the field of view of the imaging optical system. For example, the light source 30a may be provided in a light source device, and the light emitted from the light source 30a may be guided to the GRIN lens 30b by an optical fiber 30d. Alternatively, instead of using the prism 30c, a DOE (Diffractive Optical Element) may be used instead of the GRIN lens 30b, and the light source 30a, the DOE, and the optical fiber that guides the light from the light source 30a to the DOE may be oriented obliquely with respect to the optical axis LI, thereby emitting the measurement assist light in a direction that crosses the field of view of the imaging optical system.

[0040] 6, the auxiliary measurement light is emitted such that its optical axis LM intersects with the optical axis LI of the objective lens 21. Assuming that observation is possible within an observation distance range R1, the positions of the spots SP formed on the subject by the auxiliary measurement light in the imaging range (indicated by arrows QN, QM, and QF) at each point (the points where the arrows QN, QM, and QF intersect with the optical axis LM) differ between the near end PN, the center PM, and the far end PF of range R1. The imaging angle of view of the imaging optical system is represented within the region sandwiched between two solid lines 45, and measurement is performed in the central region of this imaging angle of view (the region sandwiched between two dotted lines 46) where aberration is minimal.

[0041] As described above, by emitting the fill-measurement light with its optical axis LM intersecting the optical axis LI, the sensitivity of the spot position to changes in observation distance is high, making it possible to measure the size of the subject with high precision. Then, by capturing an image of the subject illuminated with the fill-measurement light using the image sensor 32, a captured image including the spot SP is obtained.

[0042] The signal processing unit 39 functions as a position identifying unit that identifies the position of the spot SP based on the captured image. Specifically, it identifies coordinate information related to the position of the spot SP. In the captured image, the spot SP is displayed as a substantially circular red area that contains many components corresponding to the color of the measurement assist light. Therefore, the position of the spot SP is identified from the substantially circular red area. As a method for identifying the position, for example, the captured image is binarized, and the center of gravity of the white part (pixels whose signal intensity is higher than the binarization threshold) in the binarized image is identified as the position of the spot SP.

[0043] The signal processing unit 39 also functions as an observation distance detection unit that detects the observation distance based on the position of the spot SP. The signal processing unit 39 detects the observation distance from the position of the spot SP by referring to an observation distance table that stores the relationship between the position of the spot SP in the captured image and the observation distance. Note that it is preferable that coordinate information regarding the position of the spot SP, the observation distance, etc. be saved as auxiliary data of the captured image.

[0044] As shown in Fig. 7, the distal end portion 12d includes a distal end portion main body 51, a distal end cap 52, an objective lens 21, an illumination lens 22 (see Fig. 8), a treatment tool outlet 24 (see Fig. 8), an air / water supply nozzle 25, etc. The distal end portion main body 51 is formed of a hard material such as metal, and holds various components disposed in the distal end portion 12d, such as an imaging optical system 29b, the air / water supply nozzle 25, a connecting pipe 53, a light guide 28 (see Fig. 3), and a treatment tool insertion tube 54 (see Fig. 8). Note that the light guide 28, the treatment tool insertion tube 54, etc. are omitted in Fig. 7 to avoid complication of the drawing.

[0045] The tip cap 52 is made of an insulating resin material and covers the tip side of the tip body 51 of the insertion section 12a in the axial direction Z. In the following, the end face on the tip side (objective side) in the axial direction Z may be referred to as the tip face or tip, and the end face opposite the objective side may be referred to as the base face or base.

[0046] The distal end cap 52 is formed with through-holes 52a-52d that expose the objective lens 21, illumination lens 22, air / water supply nozzle 25, and auxiliary measurement light lens 23, as well as a treatment tool outlet 24 (see FIG. 8). The objective lens 21 also serves as a cover glass for the imaging optical system 29b, and is the lens located at the most distal end of the imaging optical system 29b. The imaging optical system 29b including the objective lens 21 is held by a lens barrel 55. The lens barrel 55 holds the proximal end side of the outer circumferential surface of the objective lens 21. The distal end side of the outer circumferential surface of the objective lens 21 fits into the through-hole 52a of the distal end cap 52.

[0047] The lens barrel 55 is held by the tip portion main body 51. The tip surface of the lens barrel 55 abuts against the base end side of the tip cap 52, and the objective lens 21 is disposed in a position exposed from the tip side of the tip cap 52. Note that the objective lens 21 may be a cover glass that is positioned at the most distal end of the imaging optical system 29b and does not have a lens effect. Furthermore, the objective lens 21 does not have to be a part of the imaging optical system 29b, and may simply be a cover glass that is fitted and fixed into the through-hole 52d of the tip cap 52.

[0048] The treatment tool outlet 24 is connected to a treatment tool introduction port 12f (see FIG. 1) of the operation section 12b through a treatment tool insertion tube 54 that passes through the insertion section 12a, and the inserted treatment tool is led out from the treatment tool introduction port 12f.

[0049] A suction tube (not shown) is connected to the treatment tool insertion tube 54, and suction from the treatment tool outlet 24 is performed by operating the suction button 12g (see FIG. 1) of the operation section 12b.

[0050] As shown in Fig. 8, the tip cap 52 has a tip surface 56. The tip surface 56 has a flat surface 56a, a flat surface 56b, and a guide surface 56c. The flat surface 56a is a plane perpendicular to the axial direction Z. The flat surface 56b is parallel to the flat surface 56a and is located closer to the tip side than the flat surface 56a in the axial direction Z. The guide surface 56c is located between the flat surfaces 56a and 56b.

[0051] The above-mentioned through holes 52a and 52b are arranged on the plane 56b. That is, the tip surface 21a of the objective lens 21 and the tip surfaces 22a of the pair of illumination lenses 22, which are exposed from the through holes 52a and 52b, are arranged on the plane 56b. The objective lens 21 is arranged between the pair of illumination lenses 22. The tip surface 21a of the objective lens 21 and the tip surface 22a of the illumination lens 22 are flat and are arranged on the same plane as the plane 56b in the axial direction Z (see also FIG. 7).

[0052] The above-mentioned through holes 52c and 52d are arranged on the flat surface 56a. The air and water nozzle 25 is exposed from the through hole 52c. That is, the flat surface 56a is the attachment position of the air and water nozzle 25 in the axial direction Z. The air and water nozzle 25 is connected to the air and liquid pipe 57 via a connecting pipe 53. The base end of the air and water nozzle 25 is fitted onto one end of the connecting pipe 53, and one end of the air and liquid pipe 57 is fitted onto the other end.

[0053] An injection tube portion 25a is formed on the tip side of the air and water nozzle 25. The injection tube portion 25a is formed in a cylindrical shape that protrudes from the base end of the air and water nozzle 25 in a direction that bends at 90 degrees, for example, and has an injection port 25b at its tip. The injection tube portion 25a is disposed so as to protrude from the through-hole 52c to the tip side in the axial direction Z.

[0054] The nozzle 25b of the air and water nozzle 25 is arranged facing the objective lens 21. As a result, the air and water nozzle 25 injects a cleaning liquid or gas, which is a fluid, onto the tip surface 21a of the objective lens 21 and its surrounding area.

[0055] The air and water supply nozzle 25 is connected to an air and liquid supply pipe 57 that passes through the inside of the endoscope 12, and is connected to an air and water supply device (not shown) connected to the endoscope 12 via the air and liquid supply pipe 57.

[0056] When the leak hole formed in the air and water supply button 12h (see Figure 1) of the operating unit 12b is closed with a finger, gas from the air and water supply device is sprayed from the air and water supply nozzle 25, and when the air and water supply button 12h is pressed with the finger that has closed the leak hole, cleaning liquid from the air and water supply device is sprayed from the air and water supply nozzle 25.

[0057] The procedure for cleaning the objective lens 21 is, for example, to spray cleaning liquid from the air and water nozzle 25 to remove any adhesions such as blood or body fluids that have adhered to the objective lens 21, and then to spray gas from the air and water nozzle 25 to remove any cleaning liquid remaining on the objective lens 21 or its adjacent area.

[0058] 9, when cleaning water or gas is sprayed from the air / water nozzle 25 toward the objective lens 21, it is preferable that the flow velocity F1 of the cleaning water at the position where it reaches the objective lens 21, i.e., at the outer periphery of the objective lens 21, is 2 m / s or more, and the flow velocity F2 of the gas at the outer periphery of the objective lens 21 is 40 m / s or more. Note that it is preferable that the flow velocities F1 and F2 satisfy the above values ​​regardless of the orientation of the tip 12d. For example, when the air / water nozzle 25 is positioned vertically below the objective lens 21, the flow velocity of the cleaning water or gas decreases due to the influence of gravity, but it is also preferable that the above values ​​be satisfied in this case.

[0059] The tip surface 23a of the auxiliary measurement light lens 23 exposed from the through-hole 52d is disposed on the flat surface 56a. That is, the attachment position of the air and water nozzle 25 and the tip surface 23a of the auxiliary measurement light lens 23 are disposed at the same position in the axial direction Z. The auxiliary measurement light lens 23 is disposed within the fluid injection range of the air and water nozzle 25, and between the objective lens 21 and the air and water nozzle 25.

[0060] 10 , in this embodiment, when the tip surface 56 is viewed from the axial direction Z, the measurement assist light lens 23 is disposed in a region connecting the injection port 25b of the air and water nozzle 25 and the outer periphery of the objective lens 21. This allows the measurement assist light lens 23 to be simultaneously injected with fluid from the air and water nozzle 25 toward the objective lens 21.

[0061] Furthermore, in this embodiment, the central axis CA of the measurement auxiliary light lens 23 is located on the center line CL of the injection tube portion 25a, but this is not limited thereto. The measurement auxiliary light lens 23 only needs to be arranged within the fluid injection range of the air / water supply nozzle 25 and between the objective lens 21 and the air / water supply nozzle 25, and the position of the central axis CA may be shifted from the center line CL.

[0062] Preferably, the outer diameter d1 of the measurement assist light lens 23 is 0.5 mm or more and 1.6 mm or less, the first minimum distance G1, which is the minimum distance between the outer periphery of the objective lens 21 and the outer periphery of the measurement assist light lens 23, is 0 mm or more and 1.5 mm or less, and the second minimum distance G2, which is the minimum distance between the outer periphery of the measurement assist light lens 23 and the tip of the air / water supply nozzle 25, is 0 mm or more and 0.5 mm or less. By making the first minimum distance G1 and the second minimum distance G2 as small as possible, the cleaning water or gas sprayed from the air / water supply nozzle 25 toward the objective lens 21 is sprayed onto the objective lens 21 while maintaining a sufficient flow rate when it reaches the objective lens 21. Furthermore, the outer diameter d1 of the measurement assist light lens 23 is preferably smaller than the outer diameter d2 of the objective lens 21 (see FIG. 11). Furthermore, the outer diameter d1 of the measurement assist light lens 23 is preferably smaller than the opening width W1 of the air / water supply nozzle 25 (see FIG. 11).

[0063] In this embodiment, a guide surface 56c is provided between the flat surface 56a and the flat surface 56b. As described above, the flat surface 56a and the flat surface 56b have a step in the axial direction Z, but the guide surface 56c is formed as a continuous surface connecting the flat surface 56a and the flat surface 56b. Specifically, the guide surface 56c is an inclined surface formed flat from a position contacting the outer circumferential edge of the measurement auxiliary light lens 23 to a position contacting the outer circumferential edge of the objective lens 21.

[0064] Because guide surface 56c is disposed within the fluid injection range of air and water nozzle 25, when fluid is injected from air and water nozzle 25, the fluid is also injected onto guide surface 56c. The fluid injected onto guide surface 56c is diffused and sprayed onto objective lens 21. In this case, the fluid injection range of air and water nozzle 25 may include all of guide surface 56c, or only a portion of guide surface 56c. In this embodiment, guide surface 56c is entirely included within the area connecting injection port 25b of air and water nozzle 25 and the outer periphery of objective lens 21.

[0065] 11, the opening width W1 of the air and water nozzle 25 is smaller than the outer diameter d2 of the objective lens 21. As described above, the guide surface 56c is located within the fluid injection range of the air and water nozzle 25, and therefore the fluid is diffused by the guide surface 56c. Therefore, the fluid diffused by the guide surface 56c is sprayed onto the objective lens 21 (as indicated by the dashed arrow in FIG. 11), thereby improving the cleanability of the objective lens 21, whose outer diameter d2 is larger than the opening width W1 of the air and water nozzle 25.

[0066] 12, in the tip 120, the fluid ejected from the air and water nozzle 125 travels straight without diffusing and is sprayed onto the objective lens 121. Therefore, for an objective lens 121 whose outer diameter d12 is larger than the opening width W11 of the air and water nozzle 125, the fluid may not be sprayed onto both sides of the fluid ejection range (the shaded areas), resulting in residual dirt. In contrast, this does not occur in the present embodiment, since the guide surface 56c is provided.

[0067] The operation of the above configuration will be described. When the length measurement mode is set, the system control unit 41 controls the operation of the image sensor 32 via the imaging control unit 33, and also controls the operation of the light source unit 26 of the light source device 14 and the light source 30a of the assist measurement light emitter 30, thereby controlling the illumination light and the assist measurement light according to a preset light emission pattern. After the image sensor 32, the light source unit 26, and the light source 30a start operating, the insertion section 12a is inserted into the subject, for example, into the digestive tract.

[0068] Light from the light source device 14 passes through the light guide 28 and the illumination lens 22 and is irradiated onto the region to be observed in the digestive tract. Assist measurement light from the light source 30a passes through the assist measurement light lens 23 and is irradiated onto the region to be observed. The image sensor 32 captures an image of the inside of the digestive tract and outputs an image signal. This image signal is input to the processor device 16 via the communication I / F 36 and the communication I / F 38 and is displayed on the monitor 18. A spot SP appears in the captured image due to the irradiation of the assist measurement light.

[0069] When dirt adheres to the objective lens 21 or the measurement auxiliary light lens 23, cleaning water is sprayed from the nozzle 25b by operating the air / water supply button 12h to clean the objective lens 21. After the objective lens 21 is cleaned, gas is sprayed from the nozzle 25b by operating the air / water supply button 12h again to blow away any cleaning water remaining on the objective lens 21.

[0070] As described above, the measurement assist light lens 23 is disposed within the fluid injection range of the air and water nozzle 25 and between the objective lens 21 and the air and water nozzle 25, so when fluid is injected from the air and water nozzle 25 onto the objective lens 21, the fluid can also be injected onto the measurement assist light lens 23 at the same time. This allows the measurement assist light lens 23 to be cleaned simultaneously with the objective lens 21, so that dirt on the measurement assist light lens 23 can be efficiently removed.

[0071] Furthermore, when cleaning water or gas is sprayed from the air / water nozzle 25 toward the objective lens 21, the flow velocity F1 of the cleaning water at the outer edge of the objective lens 21 is set to 2 m / s or more, and the flow velocity F2 of the gas at the outer edge of the objective lens 21 is set to 40 m / s or more, so that the fluid is sprayed at a flow velocity sufficient to remove dirt from the objective lens 21 while also removing dirt from the measurement auxiliary light lens 23.

[0072] [Second embodiment] In the first embodiment, there is a second minimum distance G2 between the outer periphery of the fillet measurement light lens 23 and the tip of the air and water nozzle 25. In the second embodiment, however, this distance is set to 0 mm, and the fillet measurement light lens and the air and water nozzle are brought into contact with each other to regulate the position of the fillet measurement light lens. In the fillet measurement light lens 60 shown in FIG. 13, the fillet measurement light lens 61 has a notch 61a. The notch 61a is positioned facing the air and water nozzle 25. Other than the fillet measurement light lens 61 and the through holes 62a and 62b in the tip cap 52, the configuration is the same as that of the fillet measurement light lens 61 and the fillet measurement light emitter 30 of the first embodiment, and the same reference numerals are used, and description thereof will be omitted.

[0073] The notch 61a is formed at a position that avoids the optical path of the fill-in measurement light emitted from the fill-in measurement light lens 61. In this embodiment, the notch 61a is located on the opposite side of the optical axis LM2 of the fill-in measurement light with respect to the central axis CA2 of the fill-in measurement light lens 61. This prevents the outer shape of the spot SP that is formed on the subject by irradiating it with the fill-in measurement light from being missing.

[0074] As shown in FIG. 14 , the auxiliary measurement light lens 61 is cylindrical like the auxiliary measurement light lens 23 of the first embodiment, but differs in that it has a notch 61 a. The notch 61 a is an inclined surface that slopes from a distal end surface 61 b ​​of the auxiliary measurement light lens 61 toward an outer peripheral surface 61 c. The air and water nozzle 25 is incorporated into the distal end portion 60 with the distal end of the injection tube portion 25 a abutting against the notch 61 a. Note that the air and water nozzle 25 and the auxiliary measurement light lens 61 are held in the distal end portion main body 51, as in the first embodiment. In this case, the air and water nozzle 25 and the auxiliary measurement light lens 61 are incorporated into the distal end portion 60 in abutting contact with each other, and therefore the through-holes 62 a and 62 b (see FIG. 15 ) of the distal end cap 52, which are provided to expose the air and water nozzle 25 and the auxiliary measurement light lens 61, are integrally formed.

[0075] 15, for example, after the measurement assist light lens 61 is held in the tip portion main body 51 together with the prism 30c, the housing 30h, etc., the air and water nozzle 25 is held in the tip portion main body 51 together with the connection pipe 53. As described above, the air and water nozzle 25 is assembled with the injection tube portion 25a and the cutout portion 61a in contact with each other, so that the injection tube portion 25a of the air and water nozzle 25 that is in contact with the cutout portion 61a is located closer to the tip in the axial direction Z than the measurement assist light lens 61. This restricts the position of the measurement assist light lens 61 in the axial direction Z.

[0076] As described above, since the position is regulated by the air and water nozzle 25, the positioning of the fill light for measurement lens 61 in the axial direction Z can be accurately performed. Furthermore, since the position is regulated by the air and water nozzle 25, it is possible to prevent the fill light for measurement lens 61 from coming off in the axial direction Z. Furthermore, since there is no need to fix the tip side of the fill light for measurement lens 61 to the tip portion main body 51 by adhesive or the like in the assembly process, the number of steps for assembling the tip portion 60 can also be reduced.

[0077] Furthermore, in the second embodiment, the fillet measurement light lens 61 has a notch 61a formed as an inclined surface that slopes from the tip surface 61b of the fillet measurement light lens 61 toward the outer circumferential surface 61c, but this is not limited to this and any notch may be used as long as it faces the air and water nozzle 25 and abuts against the air and water nozzle 25 when incorporated into the tip portion 60. For example, as shown in Fig. 16, the fillet measurement light lens 63 may have a notch 63a that is recessed one step from the tip surface 63b of the fillet measurement light lens 63 and has a step parallel to the tip surface 63b. As a result, the position of the fillet measurement light lens 63 in the axial direction Z is restricted, similar to the second embodiment.

[0078] [Third embodiment] In the second embodiment, the position of the measurement fill light lens 61 is restricted by abutting the measurement fill light lens 61 against the air / water nozzle 25, but in the third embodiment, the position of the measurement fill light lens is restricted by abutting the measurement fill light lens against the tip cap. The tip portion 65 shown in FIG. 17 has a notch 66a in the measurement fill light lens 66, similar to the measurement fill light lens 61 in the second embodiment. The configuration other than the measurement fill light lens 66 and the through holes 67a and 67b in the tip cap 52 is similar to the tip portion 12d and measurement fill light emitting portion 30 in the first embodiment, and the same reference numerals are used, and description thereof will be omitted.

[0079] Similar to the notch 61a of the measurement fill light lens 61 of the second embodiment, the notch 66a is formed at a position that avoids the optical path of the measurement fill light emitted from the measurement fill light lens 66. This prevents the outer shape of the spot SP formed on the subject by irradiation with the measurement fill light from being missing.

[0080] As shown in FIG. 18, the cutout 66a is an inclined surface that slopes from the distal end surface 66b of the auxiliary measurement light lens 66 toward the outer peripheral surface 66c. Through holes 67a and 67b are formed in the distal end cap 52, exposing the auxiliary measurement light lens 66 and the air / water nozzle 25. The auxiliary measurement light lens 66 has the cutout 66a at a position facing the base end of the distal end cap 52. The through hole 67a is shaped by cutting out a portion of a circle to match the shape of the distal end surface 66b. The distal end surface 66b is exposed from the through hole 67a when the cutout 66a abuts against the base end of the distal end cap 52. The through hole 67a also has an inclined surface 67c (see FIG. 17) that matches the inclination of the cutout 66a. This restricts the position of the auxiliary measurement light lens 66 in the axial direction Z.

[0081] As described above, since the position is restricted by the tip cap 52, the positioning of the measurement fill light lens 66 in the axial direction Z can be accurately performed. Furthermore, restricting the position by the tip cap 52 makes it possible to prevent the measurement fill light lens 66 from coming off in the axial direction Z. Furthermore, since there is no need to fix the tip side of the measurement fill light lens 66 to the tip portion main body 51 by adhesive or the like in the assembly process, the number of assembly steps for the tip portion 65 can also be reduced.

[0082] Furthermore, as described above, the through-hole 67a is formed in a circular shape with a portion cut out, so that the nozzle 25b of the air / water nozzle 25 can be positioned close to the tip surface 66b of the measurement assist light lens 66. This makes it possible to remove dirt from the measurement assist light lens 66 more efficiently.

[0083] In the third embodiment, the measurement assist light lens 66 has the notch 66a formed as an inclined surface that slopes from the tip surface 66b toward the outer circumferential surface 66c, but this is not limited thereto and any notch that abuts against the tip cap 52 when incorporated into the tip portion 65 may be used. For example, similar to the measurement assist light lens 63 shown in Fig. 16 of the second embodiment, the notch may be recessed one step from the tip surface 66b and have a step parallel to the tip surface 66b. This restricts the position in the axial direction Z, similar to the third embodiment.

[0084] [Variations] Various modifications of the above-described embodiments are described below. Note that the same reference numerals are used for components similar to those of the above-described embodiments, and their description will be omitted. In the above-described embodiments, a measurement marker used to measure the size of an object to be observed is displayed on a captured image. Specifically, the display control unit 40 displays a measurement image on the monitor 18, in which the measurement marker is displayed on the object image based on the position of the spot SP, which is the irradiation area. More specifically, the display control unit 40 displays a measurement image on the monitor 18, in which a first measurement marker is superimposed around the spot SP. For example, a circular measurement marker is used as the first measurement marker. In this case, as shown in FIG. 19 , when the observation distance is close to the near end PN, a marker M1 indicating an actual size of 5 mm (in the horizontal and vertical directions of the object image) is displayed in alignment with the center of the spot SP1 formed on the tumor tm1 of the object. Note that when a measurement marker is displayed on the monitor 18, the observation distance may also be displayed on the monitor 18.

[0085] 20, when the observation distance is close to the center PM, a marker M2 indicating an actual size of 5 mm (in the horizontal and vertical directions of the subject image) is displayed in alignment with the center of a spot SP2 formed on a tumor tm2 of the subject. The marker display position of the marker M2 is located in the center of the subject image, which is less susceptible to distortion caused by the objective lens 21, and therefore the marker M2 is circular and not affected by distortion.

[0086] 21, a marker M3 indicating an actual size of 5 mm (in the horizontal and vertical directions of the subject image) is displayed in alignment with the center of a spot SP3 formed on the tumor tm3 of the subject. As shown in FIGS. 19 to 21 above, the size of the first measurement marker corresponding to the same actual size of 5 mm becomes smaller as the observation distance increases. Furthermore, the shape of the first measurement marker also differs depending on the marker display position in accordance with the influence of distortion caused by the objective lens 21.

[0087] 19 to 21, the center of the spot SP and the center of the marker are displayed so as to coincide with each other, but if there is no problem in terms of measurement accuracy, the first measurement marker may be displayed at a position away from the spot SP. However, even in this case, it is preferable to display the first measurement marker near the spot.

[0088] In addition, in Figures 19 to 21, a first measurement marker corresponding to an actual size of 5 mm of the subject is displayed, but the actual size of the subject may be set to any value (e.g., 2 mm, 3 mm, 10 mm, etc.) depending on the object to be observed and the purpose of observation.

[0089] The positional relationship between the measurement marker and the spot SP is not limited to the position of the spot SP at any one of the "center of gravity," "center," or "coordinates regarded as the center" of the measurement marker, as shown in Figures 19 to 21, and the shape of the measurement marker is not limited to a circle. For example, as shown in Figures 22 to 25, the measurement marker setting unit may set a measurement marker having a scale with an end point as a base point corresponding to the position of the spot SP. The end point is a part of the shape of the measurement marker that is closer to the outer part than the central part, or a starting point or an end point, etc.

[0090] FIG. 22 shows a measurement image in which a marker M4 set by the measurement marker setting unit is superimposed on a subject image so that the position of the spot SP and the base point of the scale of the marker M4 overlap. In FIGS. 22 to 25, since the tumor tm has a three-dimensional shape, the subject image includes the tumor tm, the spot SP, and possibly a shadow SH. For more accurate measurement, the marker M4 is preferably superimposed so as to be displayed at the position of the spot SP. Therefore, even if the marker M4 is displayed at a position distant from the spot SP, it is preferable to display it as close to the spot SP as possible. The marker M4 is a straight line segment, and has scales at the start and end points of the line segment that are perpendicular to the straight line segment. When the marker M4 is a line segment or the like and has a start point and an end point, the start point and / or the end point themselves may be scales. In this case, for example, a scale in the shape of a line segment perpendicular to the straight line segment may not be required.

[0091] The marker M4 may also have the number "10" near the base point of the scale. This is the scale label LA of the marker M4, and is added to make it easy to recognize that the line segment of the marker M4 is 10 mm in actual size. Hereinafter, the numbers on the measurement markers have the same meaning. The numerical value of the scale label LA can be changed by settings, and the marker M4 may not display the scale label LA itself.

[0092] Various types of measurement markers are used depending on the settings, such as a straight line segment or a combination of straight line segments, a circle or a combination of circles, or a combination of a straight line segment and a circle.

[0093] For example, the measurement image shown in Fig. 23 includes a marker M5 whose shape is a combination of straight line segments. The marker M5 has a shape where straight line segments are combined into an L-shape, with the line segments extending upward and to the right of the paper from the corner of the L-shape as the base point, and has scales at the start and end points of each base point. Also, like the marker M4, the marker M5 has the number "10" as a scale label LA near the base point of the scale.

[0094] For example, the measurement image shown in FIG. 24 includes a marker M6 whose shape is a combination of a straight line segment and a circle. The marker M6 has a shape that combines a circle with a line segment that is the diameter of the circle, and the line segment extends to the right of the page, starting from one of the intersections of the line segment and the circle. The intersections of the line segment and the circle are used as scale marks on the line segment or circle. A scale mark SC may be provided at the point where the line segment is halved or at the center of the circle. Similarly to markers M4 and M5, marker M6 has a scale label LA with the number "10" near the base point of the scale.

[0095] As shown in Figure 25, measurement markers can take various other shapes, such as marker M7A (Figure 25(A)) which includes a scale label LA and has a line segment extending from a base point to the left on the paper, marker M7B (Figure 25(B)) which includes a scale label LA and has a line segment extending from a base point downward on the paper, or marker M7C (Figure 25(C)) which includes a scale label LA and has a line segment extending from a base point diagonally to the upper right on the paper.

[0096] In addition to these, as shown in FIG. 26, a cross shape in which vertical and horizontal lines intersect may be used. A graduated cross shape in which a scale Mx is added to at least one of the vertical and horizontal lines of the cross shape may also be used. The first measurement marker may also be a distorted cross shape in which at least one of the vertical and horizontal lines is tilted. The first measurement marker may also be a circle and cross shape in which a cross shape and a circle are combined. Alternatively, the first measurement marker may be a measurement point cloud type in which multiple measurement points EP corresponding to the actual size are combined from the spot. The number of first measurement markers may be one or more, and the color of the first measurement marker may be changed depending on the actual size.

[0097] As shown in FIG. 27, three concentric markers M8A, M8B, and M8C of different sizes (2 mm, 5 mm, and 10 mm in diameter, respectively) may be displayed as the first measurement marker on the subject image, with a spot SP formed on the tumor tm at the center. These three concentric markers are displayed in multiple numbers, eliminating the need for switching between markers and enabling measurement even when the subject has a nonlinear shape. When multiple concentric markers are displayed with the spot at the center, multiple combinations of conditions may be prepared in advance and the user may be able to select from among the combinations, rather than specifying the size and color for each marker.

[0098] In Figure 27, all three concentric markers are displayed in the same color (black), but when displaying multiple concentric markers, they may be displayed as multiple colored concentric markers with different colors for each marker. As shown in Figure 28, marker M9A is displayed with a dotted line representing red, marker M9B with a solid line representing blue, and marker M9C with a dashed line representing white. In this way, changing the colors of the markers improves their distinguishability, making measurement easier.

[0099] Furthermore, as the first measurement marker, in addition to a plurality of concentric markers, a plurality of distorted concentric markers obtained by distorting each concentric circle may be used as shown in Fig. 29. In this case, distorted concentric markers M10A, M10B, and M10C are displayed in the subject image around the spot SP formed on the tumor tm.

[0100] In the measurement mode, the illumination light and the spot light (measurement light) are constantly irradiated onto the subject, but as shown in Fig. 30, the illumination light may be constantly turned on and irradiated onto the subject, while the spot light may be turned on and off (or dimmed) every frame (or every few frames) so that the spot light is intermittently irradiated onto the subject. In this case, the position of the spot light is detected and the display settings of the measurement markers are set in the frame in which the spot light is turned on. Then, it is preferable to superimpose the measurement markers whose display settings have been set on the image obtained in the frame in which only the illumination light is irradiated.

[0101] Although the measurement light used herein is light that forms a spot when irradiated onto the subject, other light may also be used. For example, as shown in FIG. 31, a line-shaped measurement light that forms an intersection line 80 on the subject when irradiated onto the subject may be used. When the line-shaped measurement light is irradiated onto the subject, the intersection line 80, which is a linear irradiation area, is formed on the subject. In this case, a second measurement marker is generated as the measurement marker, which is composed of the intersection line 80 and a scale 82 on the intersection line 80 that serves as an indicator of the size of the subject (for example, a polyp P).

[0102] When using a line-shaped measurement light as the measurement light, the illumination light and the line-shaped measurement light may be constantly irradiated onto the subject during the length measurement mode, or, as shown in Fig. 32, the illumination light may be constantly irradiated onto the subject, while the line-shaped measurement light may be intermittently irradiated onto the subject by repeatedly turning on and off (or dimming) the line-shaped measurement light every frame (or every few frames). In this case, the position of the line-shaped measurement light and the display setting of the measurement marker are performed in the frame in which the line-shaped measurement light is turned on. Then, it is preferable to superimpose the measurement marker for which the display setting has been performed on the image obtained in the frame in which only the illumination light is irradiated.

[0103] As for the measurement light, stripe pattern light ZPL may be used, which, when irradiated onto the subject, forms a stripe pattern of light on the subject as shown in FIG. 33 (see, for example, JP 2016-198304 A). The stripe pattern light ZPL is obtained by irradiating a specific laser light onto a liquid crystal shutter (not shown) with variable transmittance, and is formed from two different vertical stripe patterns in which regions that transmit the specific laser light (transmitting regions) and regions that do not transmit the specific laser light (non-transmitting regions) are periodically repeated in the horizontal direction by the liquid crystal shutter. When stripe pattern light is used as the measurement light, the period of the stripe pattern light changes depending on the distance to the subject. Therefore, the period or phase of the stripe pattern light is shifted by the liquid crystal shutter and irradiated multiple times, and the three-dimensional shape of the subject is measured based on multiple images obtained by shifting the period or phase.

[0104] For example, a stripe pattern light of phase X, a stripe pattern light of phase Y, and a stripe pattern light of phase Z are alternately irradiated onto the subject. The stripe pattern light of phases X, Y, and Z has a vertical stripe pattern phase shifted by 120° (2π / 3). In this case, three types of images obtained based on each stripe pattern light are used to measure the three-dimensional shape of the subject. For example, as shown in FIG. 34, it is preferable to irradiate the subject with stripe pattern light of phase X, stripe pattern light of phase Y, and stripe pattern light of phase Z by switching between them every frame (or every few frames). It is preferable to constantly irradiate the subject with illumination light.

[0105] As shown in FIG. 35, the measurement light may be a grid-pattern measurement light LPL that forms a grid pattern when irradiated onto an object (see, for example, Japanese Patent Application Laid-Open No. 2017-217215). In this case, the three-dimensional shape of the object is measured based on the deformation of the grid pattern when the grid-pattern measurement light LPL is irradiated onto the object, and therefore accurate detection of the grid pattern is required. Therefore, the grid-pattern measurement light LPL is not a perfect grid, but is slightly deformed from the grid shape, for example, by making it wavy, to improve the detection accuracy of the grid pattern. In addition, the grid pattern has an S code indicating that the endpoints of the left and right horizontal line segments are continuous. When detecting the grid pattern, the S code is detected in addition to the pattern itself, thereby improving the pattern detection accuracy. The grid pattern may be a pattern in which vertical and horizontal lines are regularly arranged, or a pattern in which multiple spots are arranged vertically and horizontally in a grid pattern.

[0106] When using a grid-pattern measurement light LPL as the measurement light, the illumination light and the grid-pattern measurement light LPL may be constantly irradiated onto the subject during the length measurement mode. Alternatively, as shown in FIG. 36, while the illumination light is constantly irradiated onto the subject, the grid-pattern measurement light LPL may be intermittently irradiated onto the subject by repeatedly turning on and off (or dimming) the grid-pattern measurement light LPL every frame (or every few frames). In this case, in the frame in which the grid-pattern measurement light LPL is turned on, the three-dimensional shape is measured based on the grid-pattern measurement light LPL. Then, it is preferable to superimpose the measurement results of the three-dimensional shape on the image obtained in the frame in which only the illumination light is irradiated.

[0107] As shown in Fig. 37, three-dimensional planar light TPL represented by reticulated lines on the subject image may be used (see, for example, JP2017-508529A). In this case, the tip 12d is moved so that the three-dimensional planar light TPL is aligned with the measurement subject. When the three-dimensional planar light TPL intersects with the measurement subject, the distance to the intersection curve CC between the three-dimensional planar light TPL and the subject is calculated by processing based on manual operation of a user interface or the like, or by automatic processing.

[0108] When three-dimensional planar light TPL is used as measurement light, the illumination light and three-dimensional planar light TPL may be constantly irradiated onto the subject during the length measurement mode, or, as shown in FIG. 38, while the illumination light is constantly irradiated onto the subject, the three-dimensional planar light TPL may be intermittently irradiated onto the subject by repeatedly turning on and off (or dimming) the three-dimensional planar light TPL every frame (or every few frames).

[0109] In each of the above embodiments, the hardware structure of the processing units that execute various processes, such as the signal processing unit 39, the display control unit 40, and the system control unit 41, is the following various processors: The various processors include a CPU (Central Processing Unit), which is a general-purpose processor that executes software (programs) and functions as various processing units, a GPU (Graphical Processing Unit), a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacturing, such as an FPGA (Field Programmable Gate Array), and a dedicated electric circuit, which is a processor having a circuit configuration designed specifically for executing various processes.

[0110] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (for example, multiple FPGAs, a combination of a CPU and an FPGA, or a combination of a CPU and a GPU). Also, multiple processing units may be configured with a single processor. Examples of multiple processing units configured with a single processor include, first, a configuration in which one or more CPUs and software are combined to form a single processor, as typified by client or server computers, and this processor functions as multiple processing units. Second, a configuration in which a processor is used to realize the functions of an entire system including multiple processing units on a single IC (Integrated Circuit) chip, as typified by a system-on-chip (SoC). In this way, the various processing units are configured with one or more of the above-mentioned various processors as a hardware structure.

[0111] Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit in the form of a combination of circuit elements such as semiconductor elements. [Explanation of symbols]

[0112] 10 Endoscopy System 12 Endoscopy 12a Insertion part 12b Operation section 12c curved section 12d Tip 12e Angle Knob 12f Treatment tool introduction port 12g suction button 12h Air and water supply button 13a Mode switch 13b Freeze Switch 14 Light source device 16 Processor Unit 18 monitors 19 User Interface 21 Objective Lens 21a Tip surface 22 Lighting lens 22a Tip surface 23 Measurement auxiliary light lens 23a Tip surface 23b Proximal surface 24 Treatment tool outlet 25 Air and water supply nozzle 25a Injection cylinder part 25b Nozzle 26 Light source section 27 Light source control unit 28 Light Guide 29a Illumination optical system 29b Imaging optical system 30 Measurement auxiliary light emitting section 30a light source 30b lens 30b GRIN (Gradient Index) lens 30c Prism 30d optical fiber 30e fiber jacket 30f ferrule 30g reinforcement 30h Housing 32 Image sensor 33 Imaging control unit 34 CDS / AGC circuit 35 A / D converter 36 Communication I / F (Interface) 38 Communication I / F (Interface) 39 Signal Processing Section 40 Display control unit 41 System control unit 42 Still image storage section 43 Still image storage control section 45 solid line 46 Dotted Line 51 Tip body 52 Tip cap 52a through hole 52b Through hole 52c through hole 52d through hole 53 Connecting Pipe 54 Treatment instrument insertion tube 55 Lens barrel 56 Tip surface 56a plane 56b plane 56c Guide surface 57 Air and liquid supply pipe 60 Tip 61 Measurement auxiliary light lens 61a Notch 61b Tip surface 61c Outer surface 62a through hole 62b Through hole 63 Measurement auxiliary light lens 63a Notch 63b Tip surface 65 Tip 66 Measurement auxiliary light lens 66a Notch 66b Tip surface 66c Outer surface 67a Through hole 67b Through hole 67c slope 80 Crossing Lines 82 scales 120 Tip 121 Objective Lens 125 Air and water supply nozzle CA center axis CA2 center axis CL center line d1 Outer diameter D1 1st direction d12 outer diameter d2 Outer diameter D2 2nd direction F1 flow rate F2 flow rate G1 1st minimum distance G2 2nd minimum distance H Subject LI optical axis LM optical axis LM2 optical axis LPL lattice pattern measurement light M1, M2, M3, M4, M5, M6, M7A, M7B, M7C, M8A, M8B, M8C, M9A, M9B, M9C, M10A, M10B, M10C markers Mx scale PF far end PM midpoint PN near end QF Arrow QM Arrow QN arrow R1 Range SC scale SH Shadow SP, SP1, SP2, SP3 spots tm, tm1, tm2, tm3 tumors TPL 3D plane light W1, W11 opening width Z axis direction ZPL Stripe Pattern Light

Claims

1. an insertion section to be inserted into a subject; a distal end surface provided at the distal end of the insertion portion; an observation window disposed on the tip surface; a fluid ejection nozzle disposed on the tip surface and ejecting a fluid toward the observation window; two illumination lenses disposed on the tip surface for irradiating an object with illumination light; an auxiliary light irradiation window disposed on the tip surface and emitting auxiliary measurement light used for measuring the subject; the observation window is disposed between the two illumination lenses; the auxiliary light irradiation window is disposed within a fluid ejection range of the fluid ejection nozzle and between the observation window and the fluid ejection nozzle; emitting the auxiliary measurement light to a specific region of the subject in a state where the optical axis of the auxiliary measurement light intersects with the optical axis of the observation window; An endoscope in which the specific region is included in a captured image obtained by capturing an image of the subject.

2. 2. The endoscope according to claim 1, wherein the opening width of the fluid ejection nozzle is smaller than the outer diameter of the observation window, and the outer diameter of the auxiliary light emission window is smaller than the opening width of the fluid ejection nozzle.

3. 3. The endoscope according to claim 1, wherein the auxiliary light irradiation window is disposed within a region connecting the injection port of the fluid injection nozzle and an outer periphery of the observation window, and the illumination lens is disposed outside this region.

4. a tip end surface of the observation window and a tip end surface of the illumination lens are located on the tip end side in the axial direction of the insertion portion with respect to an attachment position of the fluid ejection nozzle and a tip end surface of the auxiliary light irradiation window, 4. An endoscope according to claim 1, further comprising a guide surface that is continuous from the outer periphery of said auxiliary light irradiation window to the outer periphery of said observation window.

5. an opening width of the fluid ejection nozzle is smaller than an outer diameter of the observation window; 5. An endoscope according to claim 4, wherein said guide surface is located within a fluid ejection range of said fluid ejection nozzle.

6. the fluid ejection nozzle ejects a liquid or a gas as the fluid, 6. The endoscope according to claim 1, wherein, when a liquid or a gas is sprayed from the fluid spray nozzle toward the observation window, the flow velocity of the liquid at a position where it reaches the observation window is 2 m / s or more, and the flow velocity of the gas at a position where it reaches the observation window is 40 m / s or more.

7. the outer diameter of the auxiliary light irradiation window is 0.5 mm or more and 1.6 mm or less; 7. The endoscope according to claim 1, wherein a first minimum distance, which is the minimum distance between an outer peripheral edge of the observation window and an outer peripheral edge of the auxiliary light irradiation window, is 0 mm or more and 1.5 mm or less, and a second minimum distance, which is the minimum distance between the outer peripheral edge of the auxiliary light irradiation window and a tip of the fluid ejection nozzle, is 0 mm or more and 0.5 mm or less.

8. An endoscope according to any one of claims 1 to 7; a light source device; a processor unit; An endoscope system comprising:

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