JP5279863B2 - Electronic endoscope and electronic endoscope system - Google Patents

Abstract

The invention relates to an electronic endoscope and an electronic endoscope system, when can acquire observation images with high comparison between a blood vessel and peripheral parts in an enlarged observation mode. The front end part of an insert part comprises a front end part main body, a front protection cap, an objective lens, and an illuminating lens. A blue ray reflecting face is formed on the front end face of the front protection cap. The objective lens and the illuminating lens are equipped on a window formed on the front protection cap. The surfaces of the objective lens and the illuminating lens share the same plane with the blue ray reflecting face. The reflection rays from the surface of an observation part are reflected with blue rays again through the blue ray reflection face for illuminating the observation part. The blood vessel is prominent due to the fact that the proportion of the blue rays inside the illumination rays is increased.

Description

  The present invention relates to an electronic endoscope and an electronic endoscope system for observing the inside of a subject.

  In the medical field, many diagnoses and treatments using an electronic endoscope are performed. An electronic endoscope has an observation optical system for capturing image light in a subject at the distal end of an insertion portion that is inserted into the subject, and an image sensor on which the image light captured by the observation optical system is imaged And an illumination optical system for irradiating illumination light into the subject.

  Conventionally, there is an electronic endoscope provided with a mechanism for changing the focal length of an observation optical system. In such an electronic endoscope, since the focal length can be switched between normal observation and magnified observation, first, normal observation is performed, and when an abnormal site such as a lesion is found, switching to magnified observation is clear. An observation image can be obtained.

  When magnifying observation with an electronic endoscope, the depth of field of the observation optical system becomes narrower than normal observation. Therefore, the surface of the subject cannot be focused unless the distance between the surface of the subject and the tip of the observation optical system (referred to as working distance) is a predetermined distance. Illumination light reflected on the surface of the subject because the illumination optical system also approaches the subject when the insertion unit is moved and the observation optical system is brought closer to the subject in order to make the distance in focus on the subject's surface. Is returned and reflected again at the endoscope tip, and the reflected light reflected by the endoscope tip irradiates the surface of the subject again.

  When the surface of the endoscope tip is generally black, the reflectance is low, and the reflected light reflected by the endoscope tip does not irradiate the surface of the subject again. For this reason, when observing the observation optical system close to the subject, the illumination of the illumination optical system does not reach the observation range of the observation optical system with an electronic endoscope having a low reflectance at the distal end of the endoscope. There may be a missing state.

  Therefore, in the electronic endoscope described in Patent Document 1, a hood is attached to the distal end portion of the endoscope, and the inner surface of the hood is a white reflecting surface, thereby increasing the reflectance. Thereby, when the observation optical system is brought close to the subject, it is possible to suppress the observation range from being in a hollow state.

JP 2003-235789 A

  In medical electronic endoscopes, when performing magnified observation, there is a case where it is desired to perform observation so that a blood vessel and a peripheral portion can be distinguished. However, when the electronic endoscope described in Patent Document 1 is used, there are cases where the contrast between the blood vessel and the peripheral portion is lowered, making observation difficult. Hemoglobin, which is a blood component, has a high blue light absorption rate and a low red light absorption rate. That is, blue light is absorbed by the surface layer, but red light reaches deep inside the subject. As in the electronic endoscope described in Patent Document 1, the object is again irradiated with the reflected light from the white reflecting surface, and the white light whose light intensity has increased has light with wavelengths from blue light to red light. Since it is included evenly, red light that has reached the inside is scattered and mixed within the observation range in addition to the blue light necessary for observing the blood vessel and the surrounding region. As a result, the contrast between the blood vessel and the peripheral portion is lowered.

  The present invention has been made in view of the above problems, and an electronic endoscope that can obtain an observation image having a large contrast between a blood vessel and a peripheral portion when observation is performed close to the surface of the subject. And it aims at providing an electronic endoscope system.

An electronic endoscope according to the present invention is provided at a distal end portion of an insertion portion to be inserted into a subject, an observation optical system for taking an image light in the subject and performing observation, and a focus of the observation optical system Focus changing means for changing the distance between normal observation and magnified observation, an image sensor on which image light in the observation range captured by the observation optical system is imaged, and illumination for irradiating illumination light toward the observation range An optical system, and a blue light reflecting surface provided at a position facing the observation range and around the observation optical system and having a maximum light reflectance in a wavelength range of 400 nm to 550 nm. It is characterized by.

An electronic endoscope according to the present invention is provided at a distal end portion of an insertion portion to be inserted into a subject, an observation optical system for taking an image light in the subject and performing observation, and a focus of the observation optical system Focus changing means for changing the distance between normal observation and magnified observation, an image sensor on which image light in the observation range captured by the observation optical system is imaged, and illumination for irradiating illumination light toward the observation range An optical system is provided at a position facing the observation range and in the vicinity of the observation optical system, and reflects light having a wavelength of 400 nm or more and 550 nm or less with a reflectance of 50% or more, and is larger than 550 nm and 700 nm. A blue light reflecting surface that reflects light having a wavelength less than 400 nm or more and having a reflectance lower than that of light having a wavelength of 550 nm or less, and reflects light having a wavelength of 700 nm or more with a reflectance of 5% or less; Characterized in that it comprises.

  It is preferable that the tip portion includes a tip portion main body and a tip protection cap fixed to the tip side of the tip portion main body, and the blue light reflecting surface is formed on the tip protection cap. Moreover, it is preferable to provide the hood with which the outer peripheral surface of the front-end | tip part is mounted | worn, and the said blue light reflective surface is formed in the said hood.

  The distal end portion has a recessed portion in which a part of the outer peripheral surface is cut out, and the observation optical system is provided at a position exposed from the recessed portion, and is viewed from the side perpendicular to the insertion direction of the inserting portion. It is a side-view observation optical system that captures image light from a direction, and the blue light reflecting surface is preferably provided in the recess.

  The recessed portion is formed of a first recessed surface orthogonal to the side viewing direction, a second recessed surface that is troubled by the outer peripheral surface and the first recessed surface and is inclined toward the tip side, The observation optical system is provided at a position exposed from the first concave surface, the illumination optical system is provided at a position exposed from the second concave surface, and the blue light reflecting surface is the first reflective surface. It is preferable to be formed on the concave surface.

  The electronic endoscope system of the present invention includes the electronic endoscope provided with a light guide that guides illumination light to the illumination optical system, a light source that emits light, and light from the light source to collect the light. When the condensing means to be incident on the guide and the observation optical system are switched from a state in which the observation optical system can be normally observed to a state in which the observation can be magnified, the light condensing unit is positioned on the optical path from the light source to the light guide. Partially dimming means for partially dimming only the dimming region located in the center of the incident light and transmitting the light without dimming in the transmissive region located around the dimming region. And the illumination optical system irradiates illumination light in accordance with a distribution of light intensity incident on the light guide.

According to the present invention, the blue light reflection surface provided at the position facing the observation range and around the observation optical system has a maximum light reflectance in a wavelength range of 400 nm or more and 550 nm or less . An observation image having a large contrast between the blood vessel and the peripheral portion can be obtained.

It is an external appearance perspective view of an electronic endoscope system. It is a perspective view which shows the structure of the front-end | tip part of an electronic endoscope. It is sectional drawing of the front-end | tip part cut | disconnected along the observation optical system and the illumination optical system. It is a graph which shows the extinction coefficient of hemoglobin. It is a block diagram which shows the outline | summary of the electric constitution of an electronic endoscope system. It is explanatory drawing explaining the state at the time of use of an electronic endoscope. It is a perspective view which shows the structure of 2nd Embodiment of this invention. It is sectional drawing of the insertion part front-end | tip part shown in FIG. It is a perspective view which shows the structure of 3rd Embodiment of this invention. It is sectional drawing of the insertion part front-end | tip part shown in FIG. It is a block diagram which shows the outline | summary of the electrical structure of 3rd Embodiment. It is a top view of a partial dimming plate. It is explanatory drawing which shows the structure of a light source part. It is a perspective view which shows the structure of 4th Embodiment of this invention. It is sectional drawing of the insertion part front-end | tip part shown in FIG.

  As shown in FIG. 1, the electronic endoscope system 10 includes an electronic endoscope 11, a processor device 12, a light source device 13, an air / water supply device 14, and the like. The air / water supply device 14 is built in the light source device 13 and is a well-known air supply device (pump or the like) 14a for supplying air, and a washing water tank that is provided outside the light source device 13 and stores washing water. 14b. The electronic endoscope 11 includes an insertion portion 16 to be inserted into a subject, a hand operation portion 17 connected to a proximal end portion of the insertion portion 16, and a connector 18 connected to the processor device 12 and the light source device 13. And a universal cord 19 that connects between the hand operating section 17 and the connector 18.

  The insertion portion 16 is provided at the distal end thereof, and includes a distal end portion 16a having a built-in CCD image sensor (see FIG. 3; hereinafter referred to as CCD) 38 as an imaging element for in-subject imaging, and a distal end portion 16a. It comprises a bendable bending portion 16b provided continuously at the base end, and a flexible flexible tube portion 16c provided continuously at the base end of the bending portion 16b.

  The connector 18 is a composite type connector to which the processor device 12, the light source device 13, and the air / water supply device 14 are connected. The hand operating section 17 includes an angle knob 21 for bending the bending section 16b vertically and horizontally, and an air / water supply button 22 for ejecting air and water from an air / water supply nozzle 30 (see FIG. 2). An operating member is provided. The hand operating section 17 is provided with a forceps inlet 23 for inserting a treatment instrument such as an electric knife into a forceps channel (not shown).

  The processor device 12 is electrically connected to the light source device 13 and comprehensively controls the operation of the electronic endoscope system 10. The processor device 12 supplies power to the electronic endoscope 11 via the universal cord 19 and a transmission cable inserted into the insertion portion 16 and controls driving of the CCD 38 described later. Further, the processor device 12 acquires an imaging signal output from the CCD 38 via a transmission cable, and performs various image processing to generate image data. The image data generated by the processor device 12 is displayed as an observation image on a monitor 24 connected to the processor device 12 by a cable.

  2 and 3, the distal end portion 16a includes a distal end portion main body 25, a distal end protective cap 26 fixed to the distal end side of the distal end portion main body 25, an observation lens 27 that constitutes an observation optical system 36 described later, Illumination lenses 28a and 28b as illumination optical systems, a forceps outlet 29, and an air / water supply nozzle 30 are provided. The rear end of the distal end portion main body 25 is connected to a bending piece (not shown) on the distal end side that constitutes the bending portion 16b.

  The tip protection cap 26 includes a tip plate portion 26 a that covers the tip side of the tip portion main body 25 and a cylindrical portion 26 b that covers the outer peripheral surface of the tip portion main body 25. An outer skin layer 31 covering the outer peripheral surface of the curved portion 16b extends to the distal end portion body 25, the distal end of the outer skin layer 31 and the rear end of the cylindrical portion 26b are brought into contact with each other, and the end portions are fixed with an adhesive or the like. . The distal end plate portion 26 a is formed with a distal end surface 26 c that is flat and orthogonal to the axial direction (insertion direction) of the insertion portion 16 and is located on the distal end side. A blue light reflecting surface 32 to be described later is formed on the tip surface 26c. Through-holes 26d to 26g and a forceps outlet 29 are formed in the distal end plate portion 26a.

  The observation lens 27 has an optical axis arranged along a direct viewing direction F parallel to the insertion direction of the insertion portion 16. The observation lens 27 is attached to a position exposed from the through hole 26d, and the surface serving as a light incident surface is located on the same plane as the blue light reflecting surface 32, and takes in the image light from the side viewing direction S.

  The illumination lenses 28 a and 28 b are attached to positions exposed from the through holes 26 e and 26 f, and the surface is located on the same plane as the blue light reflecting surface 32. The exit ends of the light guides 32a and 32b face the back of the illumination lenses 28a and 28b. The illumination lenses 28a and 28b irradiate the illumination light guided by the light guides 32a and 32b toward the observation range where the observation optical system 36 takes in the image light.

  The light guides 32a and 32b are formed by bundling a large number of optical fibers (for example, made of quartz) and covering the outer peripheral surface with a tube. The light guides 32a and 32b are held by the distal end body 25 and pass illumination light from the light source device 13 to the illumination lenses 28a and 28b through the insertion portion 16, the hand operating portion 17, the universal cord 19, and the connector 18. Guide each one.

  The forceps outlet 29 communicates with the forceps inlet 23 of the hand operation unit 17 via a forceps conduit (not shown). Various treatment tools inserted from the forceps inlet 23 are guided to the forceps conduit and can be treated by protruding the tip from the forceps outlet 29. The air / water supply nozzle 30 is provided so as to be exposed from the through-hole 26g, and jets air and washing water supplied from the air / water supply device 14 toward the observation lens 27 and adheres to the direct-view observation lens 27. It is possible to wash away dirty dirt.

  An imaging unit 35 is incorporated in the distal end portion 16a. The imaging unit 35 includes an observation optical system 36, a lens moving mechanism 37, and a CCD 38. The observation optical system 36 includes an observation lens 27 and a zoom lens 39.

  The CCD 38 is located on the extension of the optical axis of the observation lens 27. The zoom lens 39 is located between the observation lens 27 and the CCD 38, and is arranged with the position of the optical axis aligned with the observation lens 27 and the CCD 38. Incident light from the observation lens 27 passes through the zoom lens 39, forms an image on a light receiving surface (not shown) of the CCD 38, and is converted into an imaging signal.

  The zoom lens 39 and the lens moving mechanism 37 constitute a focal point changing unit, and the focal distance of the observation optical system 36 is changed by the lens moving mechanism 37 moving the zoom lens 39 forward and backward along the optical axis direction. The lens moving mechanism 37 includes a moving cylinder 41 as a lens holding member that holds the zoom lens 39, a fixed cylinder 42 as a guide member that guides the moving cylinder 41, and an actuator 43. The fixed cylinder 42 is fixed inside the distal end portion body 25, and the axial direction is arranged in parallel with the optical axis of the zoom lens 39. A CCD 38 is fixed to the rear end portion of the fixed cylinder 42.

  The outer peripheral surface of the movable cylinder 41 is slidably fitted to the inner peripheral surface of the fixed cylinder 42. Thereby, the zoom lens 39 is guided in the optical axis direction. The moving tube 41 is integrally provided with a connecting portion 44. The connecting portion 44 protrudes outside the fixed cylinder 42 through a slit 45 formed in the fixed cylinder 42. The actuator 43 is connected to the moving cylinder 41 via the connection portion 44. For example, a solenoid is used as the actuator 43. By driving the actuator 43, the zoom lens 39 can be moved forward and backward together with the moving cylinder 41.

  The lens moving mechanism 37 varies the focal length of the observation optical system 36 between the normal observation and the enlarged observation having a longer focal length than the normal observation by moving the zoom lens 39 forward and backward by driving the actuator 43. be able to. In the following, the position of the zoom lens 39 during normal observation is the normal observation position (position indicated by the two-dot chain line in FIG. 3), and the position of the zoom lens 39 during magnification observation is the enlarged observation position (position indicated by the solid line in FIG. 3). Called.

  The tip protection cap 26 is made of a material that selectively reflects blue light, for example, resin or rubber. As a result, a blue light reflecting surface 32 is formed on the tip surface 26 c of the tip protection cap 26. Further, since the blue light reflecting surface 32 is on the same plane as the incident surface of the observation lens 27, the blue light reflecting surface 32 is at a position facing the observation range of the observation optical system 36. Therefore, the blue light reflecting surface 32 is provided around the observation lens 27 and can selectively reflect blue light. Specifically, the blue light reflecting surface 32 reflects blue light with a wavelength of 400 nm or more and 550 nm or less with a reflectance of 50% or more, while red light has a wavelength of 700 nm or more with 5%. Reflects with a reflectance of less than%.

As shown in FIG. 4, hemoglobin in blood has an extinction coefficient of mM cm ⁻¹ depending on the wavelength of illumination light. Hb represents the extinction coefficient of oxyhemoglobin, and HbO2 represents the extinction coefficient of reduced hemoglobin. These extinction coefficients indicate the light absorption rate (absorbance) of hemoglobin. The absorption rate is low for the red light (700 nm or more) and the absorption rate for blue light (400 nm or more, 550 nm or less). I understand that it is expensive.

  FIG. 5 schematically shows the electrical configuration of the electronic endoscope system 10. The electronic endoscope 11 includes an AFE 51 and an imaging control unit 52 in addition to the imaging unit 35. The CCD 38 photoelectrically converts the image in the subject imaged on the light receiving surface as described above, accumulates signal charges, and outputs the accumulated signal charges as an imaging signal. The output imaging signal is sent to the AFE 51. The AFE 51 includes a correlated double sampling (CDS) circuit, an automatic gain adjustment (AGC) circuit, an A / D converter, and the like (all not shown). The CDS performs correlated double sampling processing on the imaging signal output from the CCD 38 to remove noise generated by driving the CCD 38. The AGC amplifies the imaging signal from which noise has been removed by CDS.

  The imaging control unit 52 is connected to the controller 57 in the processor device 12 when the electronic endoscope 11 and the processor device 12 are connected, and sends a drive signal to the CCD 38 when an instruction is issued from the controller 57. . The CCD 38 outputs an imaging signal to the AFE 51 at a predetermined frame rate based on the drive signal from the imaging control unit 52.

  The processor device 12 includes a digital signal processing circuit (DSP) 53, a digital image processing circuit (DIP) 54, a display control circuit 55, a VRAM 56, a controller 57, an operation unit 58, and the like.

  The controller 57 controls the overall operation of the processor device 12. The DSP 53 performs various signal processing such as color separation, color interpolation, gain correction, white balance adjustment, and gamma correction on the imaging signal output from the AFE 51 of the electronic endoscope 11 to generate image data. The image data generated by the DSP 53 is input to the working memory of the DIP 54. Further, the DSP 53 generates ALC control data necessary for automatic control (ALC control) of the amount of illumination light, such as an average luminance value obtained by averaging the luminance of each pixel of the generated image data, and inputs the data to the controller 57.

  The DIP 54 performs various types of image processing such as electronic scaling, color enhancement processing, and edge enhancement processing on the image data generated by the DSP 53. Image data that has been subjected to various image processing by the DIP 54 is temporarily stored as an observation image in the VRAM 56 and then input to the display control circuit 55. The display control circuit 55 selects and acquires an observation image from the VRAM 56 and displays it on the monitor 24.

  The operation unit 58 includes a known input device such as an operation panel, a mouse, and a keyboard provided in the housing of the processor device 12. The controller 57 operates each unit of the electronic endoscope system 10 in accordance with operation signals from the operation unit 58 and the hand operation unit 17 of the electronic endoscope 11.

  The light source device 13 includes a light source unit 61, a light source control unit 62, and the like. The light source unit 61 includes a light source 63, a mirror 64, a condenser lens 65, an optical fiber 66, and the like.

  The light source 63 is a white light source such as a xenon tube. The mirror 64 is a parabolic mirror formed in a bowl shape, and a mirror surface is formed on the inner peripheral surface. The mirror 64 has a light source 63 disposed near the center of the inner peripheral surface, and reflects light emitted from the light source 63 forward. The condensing lens 65 is in a position facing the inner peripheral surfaces of the light source 63 and the mirror 64, condenses the light emitted from the light source 63 and the light reflected by the mirror 64, and guides it to the optical fiber 66. The optical fiber 66 is connected to the light guides 32 a and 32 b of the electronic endoscope 11 via the connector 18. Light enters the light guides 32 a and 32 b from the condenser lens 65 through the optical fiber 66.

  The light emitted from the light source 63 is guided to the light guides 32a and 32b and enters the illumination lenses 28a and 28b. The illumination lenses 28a and 28b irradiate the subject as illumination light. The light source control unit 62 adjusts the lighting / extinguishing timing of the light source 63 according to the adjustment signal and the synchronization signal input from the controller 57 of the processor device 12.

  The lens moving mechanism 37 moves the zoom lens 39 to the normal observation position or the magnified observation position by driving the actuator 43 when an instruction to move the zoom lens 39 is given from the controller 57.

  The operation of the above configuration will be described with reference to FIG. When the insertion unit 16 is inserted into the subject and observation is performed with the electronic endoscope 11, the imaging unit 35 is normally observable (the zoom lens 39 is in the normal observation position) in the initial state. Normal observation is performed in this state, and an observation image obtained by imaging the inside of the subject is displayed on the monitor 24.

  In some cases, as a finer observation image, it is desired to perform magnified observation in which a blood vessel and a peripheral portion are distinguished. The surgeon performs an operation of switching from normal observation to magnified observation through the operation unit 58. The controller 57 operates the lens moving mechanism 37 in accordance with the operation of the operation unit 58 to move the zoom lens 39 from the normal observation position to the enlarged observation position. As a result, the observation optical system 36 is in a state where magnification observation is possible. As shown in FIG. 6, when performing magnified observation, the distal end portion 16 a is moved by the operator's operation in order to focus the observation optical system 36 on the surface H of the subject, and the incident surface of the observation optical system 36, that is, the observation The incident surface of the lens 27 is positioned close to the surface H of the subject. At this time, the illumination light irradiated from the illumination lenses 28a and 28b is reflected by the surface H of the subject and returned. Among the reflected light reflected by the surface H of the subject, there is also light that returns to the periphery of the observation lens 27. Since the blue light reflecting surface 32 is formed around the observation lens 27 and the blue light reflecting surface 32 is at a position facing the observation range, the reflected light from the surface H of the subject is reflected by the blue light reflecting surface 32. Blue light is reflected again and most of the red light is not reflected. The blue light selectively reflected by the blue light reflecting surface 32 irradiates the surface H of the subject again. Accordingly, since the observation range of the observation optical system 36 is irradiated with illumination light containing a large amount of blue light, the imaging unit 35 that captures the observation range obtains an observation image with a high contrast between the blood vessel and the peripheral portion. Can do.

  In the first embodiment, the blue light reflecting surface 32 is formed on the tip surface 26c of the tip protective cap 26 by molding the tip protective cap 26 from a material that selectively reflects blue light. Not limited to this, the tip protection cap 26 is formed of a general material, and a coating made of a material that selectively reflects blue light is applied to the tip surface, or a sheet made of a material that selectively reflects blue light is applied. For example, a blue light reflecting surface may be disposed around the observation lens 27. Further, the blue light reflecting surface 32 may be formed on the entire surface of the tip protection cap 26, or may be formed only on a part of the tip surface 26c located around the observation lens 27.

  In the said 1st Embodiment, although the blue light reflective surface 32 is formed in the front-end | tip protection cap 26 which comprises the front-end | tip part 16a, not only this but 2nd Embodiment shown in FIG.7 and FIG.8, A blue light reflecting surface may be formed on the hood 71 attached to the outer peripheral surface of the distal end portion 70. In FIGS. 7 and 8, parts similar to those in the first embodiment are given the same reference numerals and description thereof is omitted.

  In the second embodiment, the distal end portion 70 includes a distal end portion main body 25 and a distal end protective cap 72 fixed to the distal end of the distal end portion main body 25. The tip protection cap 72 has a tip plate portion 72a and a cylindrical portion 72b similarly to the tip protection cap 26 of the first embodiment, and exposes the observation lens 27, the illumination lenses 28a and 28b, and the air / water feed nozzle 30. Through holes 72d to 72g to be made and a forceps outlet 29 are formed. The tip protection cap 72 is formed from, for example, a general material, and the blue light reflecting surface may not be formed on the tip surface 72c.

  The hood 71 attached to the distal end portion 70 is fitted to the outer peripheral surface of the distal end portion 70, that is, the outer peripheral surface 73 of the distal end protection cap 72, and the distal end side is closer to the distal end side in the insertion direction (direct viewing direction F) than the distal end surface 72c. It is formed to protrude. The hood 71 has a tapered shape in which the inner peripheral surface is gradually inclined outward (side away from the optical axis of the observation lens 27) from the surface of the observation lens 27 toward the subject side. A blue light reflecting surface 74 is formed on the surface. The hood 71 is formed of a material that selectively reflects blue light, similar to the tip protection cap 26 of the first embodiment, and the blue light reflecting surface 74 selectively reflects blue light.

  The blue light reflecting surface 74 is disposed at a position surrounding the distal end surface 72c, that is, around the observation lens 27, and further has a tapered shape so that it faces the surface of the subject. Therefore, since the reflected light from the surface H of the subject is selectively reflected by the blue light reflecting surface 74 and irradiates the surface H of the subject again, the same effect as in the first embodiment is obtained. be able to. In the second embodiment, the blue light reflecting surface is formed on the inner peripheral surface of the hood 71 by molding the hood 71 from a material that selectively reflects blue light. However, the present invention is not limited to this. The hood 71 is formed of a general material, and a paint that selectively reflects blue light is applied to the inner peripheral surface, or a sheet made of a material that selectively reflects blue light is pasted. A blue light reflecting surface may be provided.

  In the first and second embodiments, the present invention is applied to an electronic endoscope and an electronic endoscope system including an observation optical system for observing the direct viewing direction, but the present invention is not limited thereto. In the third embodiment of the present invention described below, as shown in FIGS. 9 to 11, an electronic endoscope 81 provided with a side-view observation optical system 83 for observing the side-view direction at the distal end portion 82, and The present invention is applied to the electronic endoscope system 80. 9 to 11, parts similar to those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the third embodiment, the distal end portion 82 includes a distal end portion main body 84 and a distal end protective cap 85 that is fixed to the distal end side of the distal end portion main body 84. The tip protection cap 85 has a recessed portion 87 formed by cutting out a part of the cylindrical outer peripheral surface 86. The concave portion 87 is provided with a side-view observation lens 88 constituting the side-view observation optical system 83, a side-view illumination lens 89 as a side-view illumination optical system, a forceps outlet 90, and a water jet injection port 91. ing. The side-view observation lens 88 has an optical axis along the side-view direction S orthogonal to the insertion direction of the insertion portion 16.

  The recessed portion 87 is surrounded by a planar first recessed surface 92 orthogonal to the side viewing direction S, an outer peripheral surface 86 and the first recessed surface 92, and is a planar second inclined surface that is inclined toward the distal end side. And a recessed surface 93. The side-view observation lens 88 is attached to a position exposed from a through hole 92a formed in the first recessed surface 92, and the surface that becomes the light incident surface is located on the same surface as the first recessed surface 92. Then, the image light from the side viewing direction S is captured.

  The side illumination lens 89 is attached to a position exposed from a through hole 93 a formed in the second recessed surface 93, and the emission end of the light guide 94 faces the back of the side illumination lens 89. The side-view illumination lens 89 irradiates the illumination light guided by the light guide 94 toward an observation range where the side-view observation optical system 83 captures image light.

  Further, the second recessed surface 93 is provided with a forceps outlet 90 and a water jet injection port 91. The forceps outlet 90 communicates with the forceps inlet 23 of the hand operating portion 17 through a forceps conduit (not shown), similarly to the forceps outlet 29 of the first embodiment.

  The water jet injection port 91 communicates with a water jet pipe (not shown) disposed in the insertion portion 16, the hand operating portion 17, and the universal cord 19. The water jet line is connected to a liquid feeding device (not shown). The water jet injection port 91 is formed along a direction orthogonal to the second recessed surface 93, and can directly spray the liquid sent from the liquid feeding device into the water jet conduit.

  The light guide 94 is formed by bundling a large number of optical fibers (for example, made of quartz) and covering the outer peripheral surface with a tube. The light guide 94 is held by the tip body 84 and guides the illumination light from the light source device 13 to the side-view illumination lens 89, similarly to the light guides 32a and 32b of the first embodiment.

  As shown in FIG. 10, an imaging unit 95 is incorporated in the distal end portion 16a. The imaging unit 95 includes a side-view observation optical system 83, a lens moving mechanism 98, and a CCD 99. The tip end body 84 holds a prism 96, a zoom lens 97, a lens moving mechanism 98, a CCD 99, and the like.

  The side-view observation optical system 83 includes a side-view observation lens 88, a prism 96, and a zoom lens 97. The prism 96 is a 45 ° right-angled isosceles prism, and a mirror 96a that reflects incident light is formed on a slope facing the right angle. In this prism 96, the incident light from the side-view observation lens 88 is reflected by the mirror 96a and emitted from the emission surface 96b.

  The CCD 99 is located on the emission surface 96 b side of the prism 96. The zoom lens 97 is located between the prism 96 and the CCD 99 on the light exit surface 96 b side of the prism 96. The reflected light obtained by reflecting the incident light from the side-view observation lens 88 by the mirror 96a is imaged on the light receiving surface (not shown) of the CCD 99 via the zoom lens 97 and converted into an image signal.

  The zoom lens 97 and the lens moving mechanism 98 constitute a focus changing unit. The lens moving mechanism 98 includes a moving cylinder 41, a fixed cylinder 42, an actuator 43, and the like, similar to the lens moving mechanism 37 of the first embodiment. Similar to the lens moving mechanism 37 of the first embodiment, the lens moving mechanism 98 is configured so that the zoom lens 97 moves forward and backward by driving the actuator 43, so that the normal observation and the enlarged observation having a longer focal length than the normal observation are performed. The focal length of the side-view observation optical system 83 can be varied between

  At the distal end portion 82, the side-view observation lens 88 and the side-view illumination lens 89 are provided so as to be exposed from the first recessed surface 92 and the second recessed surface 93 which are different from each other. The illumination direction in which the lens 89 emits illumination light intersects the side view direction S in which the side view observation optical system 83 captures image light.

  The tip protection cap 85 is formed of a material that selectively reflects blue light, like the tip protection cap 26 of the first embodiment. Thereby, the blue light reflecting surface 101 is formed on the first recessed surface 92. Further, the blue light reflecting surface 101 is located on the same plane as the side-view observation lens 88 and is in a position facing the observation range of the side-view observation optical system 83. Therefore, the blue light reflecting surface 101 is provided around the side-view observation lens 88, and selectively reflects blue light as in the first embodiment.

  FIG. 11 shows an outline of an electrical configuration of an electronic endoscope system 80 to which the third embodiment is applied. The electronic endoscope system 80 includes an electronic endoscope 81 provided with a distal end portion 82, a processor device 102, and a light source device 103. In addition to the imaging unit 95, the electronic endoscope 81 includes an AFE 51, an imaging control unit 52, and the like.

  The processor device 102 includes a digital signal processing circuit (DSP) 53, a digital image processing circuit (DIP) 54, a display control circuit 55, a VRAM 56, a controller 104, an operation unit 58, and the like. Various signal processes are performed on the imaging signal output from the AFE 51 of the endoscope 11 to generate image data, and an observation image based on the image data subjected to the various image processes is displayed on the monitor 24.

  The lens moving mechanism 98 is connected to the controller 104 together with the AFE 51 and the imaging control unit 52 when the electronic endoscope 11 and the processor device 12 are connected. When the movement instruction of the zoom lens 97 is given from the controller 104, the lens moving mechanism 98 moves the zoom lens 97 to the normal observation position or the enlarged observation position by driving the actuator 43.

  The light source device 13 includes a light source unit 105, a light source control unit 106, and the like. The light source unit 105 includes a light source 107, a mirror 108, a condenser lens 109, an optical fiber 110, a partial dimming unit 111, and the like.

  The light source 107, the mirror 108, and the condensing lens 109 are the same as the light source 63, the mirror 64, and the condensing lens 65 of the first embodiment, and condenses the light emitted from the light source 107 and the light reflected by the mirror 108. To the optical fiber 110. The optical fiber 110 is connected to the light guide 94 of the electronic endoscope 11 via the connector 18. The light guide 94 and the optical fiber 110 are connected with their optical axes aligned, and light enters the light guide 94 from the condenser lens 109 through the optical fiber 110.

  The light emitted from the light source 107 is guided to the light guide 94 and enters the side view illumination lens 89. The side illumination lens 89 irradiates the subject as illumination light. The side-view illumination lens 89 and the light guide 94 are attached with their optical axes aligned. The side-view illumination lens 89 emits illumination light according to the distribution of the light intensity incident on the light guide 94. The light source control unit 106 adjusts the timing of turning on / off the light source 107 according to an adjustment signal or a synchronization signal input from the controller 104 of the processor device 102.

  The partial dimming unit 111 includes a partial dimming plate 112 and a slide mechanism 113. The partial dimming plate 112 is located between the condenser lens 109 and the optical fiber 110. As shown in FIG. 12, the partial dimming plate 112 has a disc shape, and a circular dimming filter 112a is formed in the center portion. The partial light attenuating plate 112 has a low light transmittance of the neutral density filter 112a, and a portion from the periphery to the outside of the neutral density filter 112a has a high light transmittance.

  The partial dimming plate 112 is positioned on the optical path where light enters the optical fiber 110 from the condensing lens 109, and the center position of the neutral density filter 112a is on the optical axis L1 of the condensing lens 109 (see FIG. 13). It is freely movable between the dimming position to be combined (the position indicated by the solid line in FIGS. 11 and 13) and the dimming position, that is, the retracted position (the position indicated by the two-dot chain line in FIGS. 11 and 13). Is provided.

  The slide mechanism 113 includes a guide member that guides the movement of the partial dimming plate 112 and an actuator that moves the partial dimming plate 112. As the actuator, for example, a solenoid is used. When the controller 104 gives an instruction to the light source control unit 106, the slide mechanism 113 slides the partial dimming plate 112 between the retracted position and the dimming position by driving an actuator that receives a control signal from the light source control unit 106. Let

  The controller 104 moves the slide mechanism 113 when the focal length of the side-view observation optical system 83 is switched between normal observation and magnified observation, that is, when the zoom lens 97 moves between the normal observation position and magnified observation position. To move the partial dimming plate 112 between the retracted position and the dimming position. When the zoom lens 97 is in the normal observation position, the partial dimming plate 112 is in the retracted position, and when the zoom lens 97 is in the enlarged observation position, the partial dimming plate 112 is in the dimming position.

  As shown in FIG. 13, the neutral density filter 112 a formed on the partial dimming plate 112 is dimmed out of light incident on the optical fiber 110 from the condenser lens 109 when the partial dimming plate 112 is in the dimming position. It is formed in accordance with the area A1. Since the light intensity in the vicinity of the optical axis L1 of the light condensed by the condenser lens 109 is large, the central circular area including the optical axis L1 is set as the light reducing area A1. A transmission area A2 is set around the light attenuation area A1. As a result, when the partial dimming plate 112 is in the dimming position, the partial dimming plate 112 partially dimmes only the dimming area A1 located in the center out of the light incident on the optical fiber 110 from the condensing lens 109, and the transmissive area In A2, light is transmitted without being dimmed.

  The operation of the above configuration will be described. When the insertion unit 16 is inserted into the subject and observation is performed with the electronic endoscope 11, the imaging unit 95 is normally observable (the zoom lens 97 is the normal observation position) in the initial state. At this time, in the light source unit 105, the partial dimming plate 112 is in the retracted position. Normal observation is performed in this state, and an observation image obtained by imaging the inside of the subject is displayed on the monitor 24.

  When normal observation is performed using the imaging unit 95, if the operator wants to perform magnified observation in which a blood vessel and a peripheral part are distinguished as a finer observation image, the operator performs an operation to switch from normal observation to magnified observation. This is performed by the operation unit 58. When the imaging unit 95 is in a state in which enlargement observation is possible, the illumination light emitted from the side-view illumination lens 89 is reflected by the surface of the subject and returned. Among the reflected light reflected from the surface of the subject, there is also light that returns to the periphery of the side-view observation lens 88. Since the blue light reflecting surface 101 is formed around the observation lens 88 as described above, the blue light is selectively reflected again by the blue light reflecting surface 101 from the surface of the subject. The blue light irradiates the surface H of the subject again. Since the observation range of the side-view observation optical system 83 is irradiated with illumination light containing a large amount of blue light, the imaging unit 95 that captures the observation range obtains an observation image with a large contrast between the blood vessel and the peripheral portion. be able to.

  Further, when moving the zoom lens 97 from the normal observation position to the enlarged observation position, the controller 104 controls the light source control unit 106 to operate the slide mechanism 113 to move the partial dimming plate 112 from the retracted position to the dimming position. Let Thereby, in the light source unit 105, only the dimming area A <b> 1 of the light collected by the condensing lens 109 is partially dimmed and is incident on the light guide 94. The side-view illumination lens 89 is partially dimmed by the partial light reduction plate 112 and irradiates the observation range of the side-view observation optical system 83 with illumination light according to the light intensity distribution incident on the light guide 94.

  Since the side-view illumination lens 89 emits illumination in a direction that intersects the side-view direction S in which the side-view observation optical system 83 captures image light, the observation range can be reliably illuminated. Thereby, the contrast between the blood vessel and the peripheral portion is large, and a clearer observation image can be obtained. Further, when the side-view observation optical system 83 performs magnified observation, the illumination light partially dimmed by the partial dimming plate 112 is irradiated, so that the light intensity near the optical axis of the side-view illumination lens 89 is lowered. . Therefore, when performing a magnified observation with the side-view observation optical system 83, it is possible to prevent an increase in reflected light even if the side-view observation optical system 83 is brought close to the surface of the subject, and to suppress a deviation in luminance distribution within the observation range. it can. Since the unevenness of the luminance distribution is suppressed, it is possible to prevent the occurrence of overexposure and obtain a clear observation image.

  In the third embodiment, the blue light reflecting surface 101 is formed on the first recessed surface 92 of the tip protective cap 85 by molding the tip protective cap 85 from a material that selectively reflects blue light. However, the present invention is not limited to this, and the tip protection cap 85 is made of a general material, and a coating that selectively reflects blue light is applied to the first concave surface 92 or blue light is selectively used. Alternatively, a blue light reflecting surface may be disposed around the side-view observation lens 88 by attaching a sheet made of a reflective material. Further, the blue light reflecting surface 101 may be formed on the entire surface of the tip protection cap 85, and is formed only on a part of the first concave surface 92 located around the side-view observation lens 88. Also good.

  Moreover, in the said 3rd Embodiment, the structure which consists of the slide mechanism 113 which moves the partial light reduction plate 112 in which the light reduction filter 112a with low light transmittance was formed as the partial light reduction part 111 and the partial light reduction plate 112 is used. However, the present invention is not limited to this. For example, a liquid crystal panel on which a light attenuation pattern having a low light transmittance is formed at the time of magnified observation, and a partial dimming portion composed of a liquid crystal driver for driving and controlling the liquid crystal panel, etc. Any configuration capable of partially dimming only the light region may be used.

  In the third embodiment, the blue light reflecting surface 32 is formed on the tip protection cap 85 constituting the tip portion 82. However, the present invention is not limited to this, as in the fourth embodiment shown in FIGS. In addition, a blue light reflecting surface may be formed on the hood 121 attached to the outer peripheral surface of the tip portion 120. In FIGS. 13 and 14, parts similar to those of the third embodiment are given the same reference numerals and description thereof is omitted.

  In the fourth embodiment, the tip portion 120 includes a tip portion main body 84 and a tip protection cap 122 fixed to the tip of the tip portion main body 84. The tip protection cap 122 is formed with a recessed portion 124 in which a part of the outer peripheral surface 123 is cut out, similarly to the tip protection cap 85 of the first embodiment. The recessed portion 124 is surrounded by a planar first recessed surface 125 orthogonal to the side view direction S, an outer peripheral surface 123 and the first recessed surface 125, and is a planar second inclined surface that is inclined toward the distal end side. The concave surface 126 is formed. The side-view observation lens 88 is attached to a position exposed from the through hole 125a formed in the first concave surface 125, and takes in the image light from the side-view direction S. The side-view illumination lens 89 is attached at a position exposed from a through hole 126a formed in the second concave surface 126, and the side-view observation optical system 83 takes in the image light from the illumination light guided by the light guide 94. Irradiate to range. The tip protection cap 122 is formed from, for example, a general material, and the blue light reflecting surface may not be formed on the first recessed surface 125.

  The hood 121 attached to the distal end portion 120 is formed with an opening 121 a that exposes the recessed portion 124, and fits to the outer peripheral surface of the distal end portion 120, that is, the outer peripheral surface 123 of the distal end protective cap front end protective cap 122. The hood 121 is formed so that the end surface of the opening 121 a protrudes toward the distal end side in the side view direction S with respect to the first recessed surface 125. The inner peripheral surface of the hood 121 has a tapered shape that gradually inclines outward (side away from the optical axis of the side-view observation lens 88) from the surface of the side-view observation lens 88 toward the subject. A blue light reflecting surface 127 is formed on the inner peripheral surface. The hood 121 is formed of a material that selectively reflects blue light, similar to the tip protection cap 26 of the first and third embodiments and the hood 71 of the second embodiment, and the blue light reflecting surface 127 is blue light. To selectively reflect.

  The blue light reflecting surface 127 is disposed at a position surrounding the first concave surface 125, that is, around the side-view observation lens 88, and further has a tapered shape, so that it faces the surface of the subject. Therefore, since the reflected light from the surface of the subject is selectively reflected by the blue light reflecting surface 127 and irradiates the surface H of the subject again, the same effect as in the third embodiment can be obtained. Can do. The hood 121 is formed of a general material, and a paint that selectively reflects blue light is applied to the inner peripheral surface, or a sheet made of a material that selectively reflects blue light is pasted. A blue light reflecting surface may be disposed around the side-view observation lens 88.

  In each of the above embodiments, the configuration of the tip portion including only one of the side-view observation optical system and the direct-view observation optical system is shown, but the present invention is not limited to this, and the side-view observation optical system and A configuration including both the direct-viewing observation optical system may be used. In this case, for example, the side-viewing observation optical system and the direct-viewing observation optical system are provided with switching means for blocking one of the light incident on the side-viewing observation optical system and transmitting the other. You may make it the structure which selectively performs either one in observation of a visual direction and a direct-view direction.

  In each of the above embodiments, a lens moving mechanism including a lens holding member, a guide member, and an actuator is provided.However, the present invention is not limited thereto. For example, a cam member that converts a rotational drive into a straight drive to advance and retract the zoom lens, The structure provided with the stepping motor etc. as a drive source which rotationally drives a cam member may be sufficient. In each of the above embodiments, a solenoid is used as the actuator of the lens moving mechanism. However, the present invention is not limited to this, and any actuator that can move the zoom lens forward and backward, such as a piezoelectric actuator using a piezoelectric element, is used. That's fine.

  In each of the above-described embodiments, the configuration including the zoom lens and the lens moving mechanism is used as the focus changing unit. However, the configuration is not limited thereto, and the configuration in which the focal length of the side-view observation optical system is changed between normal observation and magnified observation. For example, a configuration may be used in which the focal length of the side-view observation optical system is varied by moving the CCD in the optical axis direction. In each of the above embodiments, a CCD is used as an image pickup element that captures image light in a subject captured by a side-view observation optical system or a direct-view observation optical system.

DESCRIPTION OF SYMBOLS 10,80 Electronic endoscope system 11,81 Electronic endoscope 16 Insertion part 16a, 70,82,120 Tip part 27,88 Observation lens 28a, 28b, 89 Illumination lens 32,74,101,127 Blue light reflection surface 36, 83 Observation optical system 37, 98 Lens moving mechanism 39, 97 Zoom lens 38, 99 CCD

Claims (7)

An observation optical system that is provided at the distal end of the insertion portion that is inserted into the subject and that takes in the image light in the subject and performs observation;
Focus variable means for changing the focal length of the observation optical system between normal observation and magnified observation;
An imaging device on which image light in an observation range captured by the observation optical system is formed;
An illumination optical system that emits illumination light toward the observation range;
A blue light reflecting surface provided at a position facing the observation range and around the observation optical system and having a maximum light reflectance in a wavelength range of 400 nm or more and 550 nm or less. Electronic endoscope. An observation optical system that is provided at the distal end of the insertion portion that is inserted into the subject and that takes in the image light in the subject and performs observation;
Focus variable means for changing the focal length of the observation optical system between normal observation and magnified observation;
An imaging device on which image light in an observation range captured by the observation optical system is formed;
An illumination optical system that emits illumination light toward the observation range;
Provided at a position facing the observation range and around the observation optical system, light having a wavelength of 400 nm or more and 550 nm or less is reflected with a reflectance of 50% or more, and has a wavelength of greater than 550 nm and less than 700 nm. And a blue light reflecting surface that reflects light with a smaller reflectance than light with a wavelength of 400 nm or more and 550 nm or less, and reflects light with a wavelength of 700 nm or more with a reflectance of 5% or less. Electronic endoscope. The tip portion includes a tip portion main body and a tip protection cap fixed to the tip side of the tip portion main body.
The electronic endoscope according to claim 1, wherein the blue light reflecting surface is formed on the tip protection cap. A hood attached to the outer peripheral surface of the tip,
The electronic endoscope according to claim 1, wherein the blue light reflecting surface is formed on the hood. The tip portion has a recessed portion in which a part of the outer peripheral surface is cut out,
The observation optical system is a side-view observation optical system that is provided at a position exposed from the recess, and that captures image light from a side view direction orthogonal to the insertion direction of the insertion unit,
The electronic endoscope according to claim 1, wherein the blue light reflecting surface is provided in the recessed portion. The recessed portion is formed of a first recessed surface orthogonal to the side viewing direction, a second recessed surface that is troubled by the outer peripheral surface and the first recessed surface and is inclined toward the tip side,
The observation optical system is provided at a position exposed from the first concave surface,
The illumination optical system is provided at a position exposed from the second recessed surface,
6. The electronic endoscope according to claim 5, wherein the blue light reflecting surface is formed on the first recessed surface. The electronic endoscope according to any one of claims 1 to 6, wherein the electronic endoscope is provided with a light guide that guides illumination light to the illumination optical system;
A light source that emits light;
Condensing means for condensing the light from the light source and entering the light guide;
When the observation optical system is switched from a state in which normal observation is possible to a state in which magnification observation is possible, it is located on the optical path from the light source to the light guide, and in the center of the light incident on the light guide. A partial dimming means for partially dimming only the dimming area located, and transmitting the light without dimming in the transmissive area located around the dimming area;
The electronic endoscope system according to claim 1, wherein the illumination optical system emits illumination light in accordance with a distribution of light intensity incident on the light guide.

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