JP2012120774A - Illumination optical system unit for endoscope and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control an adhesive poured into between a protective cover and a sleeve member to be an appropriate amount.SOLUTION: An illumination optical system unit 26A comprises an optical fiber 37A, a phosphor 38, a ferrule 60 as a holding member for holding the phosphor 38 and the optical fiber 37A, a cylindrical sleeve member 61 for covering the outer periphery of the phosphor 38, and a protective cover 36 for sealing the distal end of the sleeve member 61. The ferrule 60 holds the phosphor 38 and is fitted in a fitting hole 71 of the sleeve member 61. The protective cover 36 is held by a receiving part 70 of the sleeve member 61. Since concentrically arranged circumferential grooves 75 are formed on a bottom surface 70b of the receiving part 70, when the adhesive 72 is poured into from a gap between the outer peripheral surface 36a of the protective cover 36 and the inner peripheral surface 70a of the receiving part 70, the amount of the adhesive 72 flowing from the outer side of the bottom surface 70b to the inner side is suppressed.

Description

  The present invention relates to an endoscope illumination optical system unit that irradiates an observation site in an object with illumination light to observe the inside of the object, and a method for manufacturing the same.

  Conventionally, diagnosis using an endoscope has been widely used in the medical field. The endoscope includes an observation window for capturing image light of the subject and an illumination window for irradiating illumination light toward the subject at the distal end of the insertion portion that is inserted into the subject. . The endoscope is connected to the light source device via a cord or a connector.

  The light source device has a light source for supplying illumination light for in-subject illumination to the endoscope. Illumination light from the light source is guided to the distal end of the insertion portion by a light guide inserted through the endoscope. Conventionally, a white light source such as a xenon lamp or a halogen lamp has been used as a light source constituting the light source device. However, in recent years, a light source device using a laser light source is being used instead. Laser light supplied from a light source device using this laser light source is guided to the distal end of the insertion portion by a light guide, and a phosphor disposed at the distal end of the light guide is excited and emitted by the laser light, so that white illumination light enters the body cavity. An endoscope to irradiate is described in Patent Document 1.

  Further, in an endoscope, it is necessary to irradiate illumination light with higher intensity. For this reason, a reflective film having a high reflectivity may be provided around the above phosphor in order to efficiently use the excited light as illumination light. It is known that a metal film such as silver or aluminum is suitable as the reflective film having a high reflectance.

JP 2007-20937 A

  At the time of diagnosis using an endoscope, the inside of the endoscope insertion portion inserted into the body cavity is in a highly humid state, and grease containing molybdenum disulfide is used as a lubricant on the outer peripheral surface of the insertion portion. Applied. Furthermore, in the endoscope, after the diagnosis is completed, a cleaning / disinfecting process is performed in which the endoscope is immersed in a disinfectant containing peracetic acid. As described above, since chemicals such as moisture, grease, and a disinfectant can easily enter the endoscope insertion portion, the phosphor and the reflective film that are vulnerable to moisture and chemicals are easily deteriorated.

  Therefore, the present applicant has studied an illumination optical unit for an endoscope having a structure in which the outer periphery of the phosphor is covered with a cylindrical sleeve member and the tip of the sleeve member is sealed with a protective cover that transmits illumination light. Yes. In sealing the protective cover to the sleeve member, an adhesive is poured between the protective cover and the sleeve member to bond the protective cover and the sleeve member.

  However, in the process of bonding the protective cover and the sleeve member, if the adhesive has a low viscosity, the area of the portion where the protective cover and the sleeve member are bonded is very small. It is very difficult to control to an appropriate amount. In particular, a problem arises when too much adhesive is poured between the protective cover and the sleeve member, and the adhesive flows to the position where the phosphor should be originally disposed. When manufacturing an endoscope illumination optical system unit, when a process of inserting the phosphor into the sleeve is performed after the process of bonding the protective cover and the sleeve member, the position where the phosphor should originally be disposed When the adhesive flows in, the solidified adhesive interferes with the insertion of the phosphor, and a gap is formed between the protective cover and the phosphor. Even when the protective cover and the sleeve are bonded after the step of inserting the phosphor into the sleeve, if the adhesive flows too much, the adhesive enters between the phosphor and the protective cover. A gap is formed between the two. And if the gas which the water | moisture content and the chemical | medical agent volatilized approached into the clearance gap produced between a protective cover and fluorescent substance, a fluorescent substance and a reflecting film will deteriorate and the intensity | strength of illumination light will fall.

  In addition, when there is a part that is not filled with adhesive in the circumferential direction of the inner peripheral surface of the sleeve member and the outer peripheral surface of the protective cover due to insufficient amount of adhesive to be poured, moisture and chemicals have volatilized from that part. The problem is that the gas enters and deteriorates the phosphor and the reflective film.

  The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to control an appropriate amount of adhesive poured between a protective cover and a sleeve member.

  An endoscope illumination optical system unit according to the present invention includes an optical fiber that guides and emits laser light supplied from a laser light source to a tip, and a phosphor that emits fluorescence by being excited by the laser light emitted from the optical fiber. A phosphor that forms white light composed of the fluorescence and the laser light, a protective cover that covers a front end side of the phosphor and transmits the fluorescence and the laser light, and an outer periphery of the phosphor. A sleeve member that covers and has a receiving portion that holds the protective cover on the tip side, and an adhesive is poured between the receiving portion and the protective cover, and the tip is sealed; The receiving portion is formed with a plurality of circumferential grooves arranged concentrically.

  The receiving portion includes an inner peripheral surface that faces the outer peripheral surface of the protective cover, and a bottom surface that intersects the inner peripheral surface and faces the end surface of the protective cover, and the circumferential groove is formed on the receiving portion. Preferably, it is formed on the bottom surface.

  It is preferable that the protective cover is formed with a plurality of circumferential grooves arranged on the end surface facing the bottom surface while being shifted in the radial direction with respect to the circumferential groove formed in the receiving portion.

  The adhesive is preferably a silicon-based adhesive. The adhesive is preferably mixed with glass beads.

  The method for manufacturing an endoscope illumination optical system unit according to the present invention includes an optical fiber that guides and emits laser light supplied from a laser light source to the tip, and excites fluorescence with the laser light emitted from the optical fiber. A fluorescent material that emits white light composed of the fluorescent light and the laser light, a protective cover that covers a front end side of the fluorescent material and transmits the fluorescent light and the laser light, and the fluorescent material A sleeve member that has a receiving portion for holding the protective cover on a tip end side thereof, an adhesive is poured between the receiving portion and the protective cover, and the tip is sealed. In a method of manufacturing an endoscope illumination optical system unit including a sleeve member formed with a plurality of circumferential grooves concentrically arranged in a part, an adhesive is provided between the sleeve member and the protective cover. Pouring agent Sealing the tip of the sleeve member with the protective cover; and connecting the phosphor and the optical fiber into the sleeve member from the base end side of the sleeve member whose tip is sealed with the protective cover. Inserting the phosphor into close contact with the protective cover; and bringing the phosphor into close contact with the protective cover and placing the optical fiber on the proximal end side of the phosphor, and the phosphor and the light Holding the fiber to the sleeve.

  According to the present invention, since the plurality of circumferential grooves arranged concentrically are formed in the receiving portion of the sleeve member that covers the outer periphery of the phosphor and holds the protective cover at the tip, the protective cover, the sleeve member, It is possible to make it possible to control an appropriate amount of the adhesive that is poured in between.

It is an external view which shows the structure of an electronic endoscope system. It is principal part sectional drawing which shows the structure of the front-end | tip part of an electronic endoscope. It is a top view of the front-end | tip part of an electronic endoscope. It is a block diagram which shows the electric constitution of an electronic endoscope system. It is a disassembled perspective view which shows the structure of an illumination optical system unit. It is principal part sectional drawing which shows the structure of fluorescent substance periphery. It is a top view which shows the state which poured the adhesive agent between the receiving part of a sleeve member, and a protective cover. It is explanatory drawing which shows the process when pouring an adhesive agent between the receiving part of a sleeve member, and a protective cover. It is principal part sectional drawing which shows the structure of 2nd Embodiment which formed the circumferential groove in the protective cover.

  As shown in FIG. 1, the electronic endoscope system 11 includes an electronic endoscope 12, a processor device 13, and a light source device 14. The electronic endoscope 12 is connected to a flexible insertion portion 16 that is inserted into the body of a subject, an operation portion 17 that is connected to a proximal end portion of the insertion portion 16, a processor device 13, and a light source device 14. Connector 18, and a universal cord 19 that connects between the operation unit 17 and the connector 18.

  The insertion portion 16 is provided at the distal end thereof, and is continuously provided at a distal end portion 16a having a built-in CCD image sensor (see FIG. 4; hereinafter referred to as CCD) 33 for imaging inside the subject, and a proximal end of the distal end portion 16a. The bendable bending portion 16b, and the flexible tube portion 16c having flexibility, which is connected to the base end of the bending portion 16b.

  The operation portion 17 is provided with operation members such as an angle knob 21 for bending the bending portion 16b up and down, left and right, and an air / water supply button 22 for ejecting air and water from the distal end portion 16a. Further, the operation unit 17 is provided with a forceps port 23 for inserting a treatment tool such as an electric knife into a forceps channel (not shown).

  The processor device 13 is electrically connected to the light source device 14 and comprehensively controls the operation of the electronic endoscope system 11. The processor device 13 supplies power to the electronic endoscope 12 via the universal cord 19 and a transmission cable inserted into the insertion portion 16 and controls the drive of the CCD 33. In addition, the processor device 13 acquires an imaging signal output from the CCD 33 via a transmission cable, and performs various image processing to generate image data. The image data generated by the processor device 13 is displayed as an observation image on a monitor 20 connected to the processor device 13 by a cable.

  As shown in FIG. 2, the distal end portion 16 a includes a distal end rigid portion 24 and a distal end protective cap 25 attached to the distal end side of the distal end rigid portion 24. The distal end hard portion 24 is made of a metal such as stainless steel, and a plurality of through holes are formed along the longitudinal direction. Various parts such as an imaging optical system 32 (see FIG. 4), CCD 33, illumination optical system units 26A and 26B, forceps channel, air / water supply channel (not shown) are attached to each through hole of the distal end rigid portion 24. ing. The rear end of the distal end rigid portion 24 is connected to the bending piece 27 at the distal end that constitutes the bending portion 16b. In addition, the outer tube 28 is covered on the outer periphery of the distal end rigid portion 24.

  The tip protection cap 25 is made of rubber or resin, and a through hole is formed at a position corresponding to various parts held by the tip rigid portion 24. As shown in FIG. 3, the tip protection cap 25 exposes the observation window 29, illumination optical system units 26 </ b> A and 26 </ b> B, the forceps outlet 30, the air / water supply nozzle 31 and the like from the through holes 25 a to 25 e. The pair of illumination optical system units 26 </ b> A and 26 </ b> B are arranged at symmetrical positions with the observation window 29 in between.

  As shown in FIG. 4, inside the distal end portion 16 a, a CCD 33 is placed behind the observation window 29 so that an image in the subject is formed on the imaging surface by an imaging optical system 32 including a lens group and a prism. Has been placed.

  The CCD 33 photoelectrically converts an image in the subject imaged on the imaging surface by the imaging optical system 32, accumulates signal charges, and outputs the accumulated signal charges as an imaging signal. The output imaging signal is sent to the AFE 34. The AFE 34 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 33 to remove noise generated by driving the CCD 33. The AGC amplifies the imaging signal from which noise has been removed by CDS.

  The imaging control unit 35 is connected to the controller 44 in the processor device 13 when the electronic endoscope 12 and the processor device 13 are connected, and sends a drive signal to the CCD 33 when an instruction is issued from the controller 44. . The CCD 33 outputs an imaging signal to the AFE 34 at a predetermined frame rate based on the drive signal from the imaging control unit 35.

  The illumination optical system units 26A and 26B are units that irradiate illumination light into the subject. The distal end sides of the illumination optical system units 26A and 26B are sealed by a protective cover 36, and are exposed from the distal end surface of the distal end portion 16a, that is, the through holes 25b and 25c of the distal end protective cap 25 as illumination windows.

The optical fibers 37A and 37B constituting the illumination optical system units 26A and 26B guide blue laser light supplied from the light source device 14 and emit it to the phosphor 38 provided on the emission end side. Hereinafter, the emission end sides of the optical fibers 37A and 37B are referred to as “front end sides”, and the incident end sides of the optical fibers 37A and 37B are referred to as “base end sides”. The phosphor 38 is made of, for example, YAG or BAM (BaMgAl ₁₀ O ₁₇ ), and absorbs part of the blue laser light emitted from the optical fibers 37A and 37B to emit light in a green to yellow manner. For this reason, in the illumination optical system units 26A and 26B, white light (pseudo-white) is obtained by combining blue light transmitted while diffusing the phosphor 38 and green to yellow fluorescence excited and emitted from the phosphor 38 together. Light is formed. The illumination light irradiation range is approximately the same as or larger than the imaging range of the electronic endoscope 12, and the illumination light is irradiated almost uniformly on the entire surface of the observation image.

  The processor device 13 includes a digital signal processing circuit (DSP) 40, a digital image processing circuit (DIP) 41, a display control circuit 42, a VRAM 43, a controller 44, an operation unit 45, and the like.

  The controller 44 controls the overall operation of the processor device 13. The DSP 40 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 34 of the electronic endoscope 12 to generate image data. The image data generated by the DSP 40 is input to the working memory of the DIP 41. Further, the DSP 40 generates ALC control data required 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 generated data to the controller 44.

  The DIP 41 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 40. Image data that has been subjected to various types of image processing by the DIP 41 is temporarily stored in the VRAM 43 as an observation image and then input to the display control circuit 42. The display control circuit 42 selects and acquires an observation image from the VRAM 43 and displays it on the monitor 20.

  The operation unit 45 includes a known input device such as an operation panel, a mouse, and a keyboard provided in the housing of the processor device 13. The controller 44 operates each unit of the electronic endoscope system 11 in accordance with operation signals from the operation unit 45 and the operation unit 17 of the electronic endoscope 12.

  The light source device 14 includes a laser diode (LD) 51 as a laser light source and a light source control unit 52. The LD 51 is a light source that emits blue laser light having a central wavelength of 445 nm, and is guided to the optical fiber 53 through a condenser lens (not shown). The optical fiber 53 is connected to the two optical fibers 55A and 55B via the branch coupler 54. The optical fibers 55A and 55B are connected to the optical fibers 37A and 37B of the electronic endoscope 12 via the connector 18. For this reason, the blue laser light emitted from the LD 51 is incident on the phosphor 38 constituting the illumination optical system units 26A and 26B. Then, when the blue laser light is incident, the phosphor 38 is combined with the green to yellow fluorescence that is excited to emit light, and is irradiated into the subject as white (pseudo white) illumination light.

  The light source control unit 52 adjusts the timing of turning on / off the LD 51 according to the adjustment signal and the synchronization signal input from the controller 44 of the processor device 13. Further, the light source control unit 52 communicates with the controller 44 and adjusts the amount of illumination light irradiated into the subject by adjusting the light emission amount of the LD 51. The illumination light amount control by the light source control unit 52 is ALC (Auto Light Control) control that automatically adjusts the illumination light amount according to the brightness of the photographed observation image, and the ALC control data generated by the DSP 40. Based on.

  As shown in FIGS. 2 and 5, the illumination optical system unit 26A includes a single mode optical fiber 37A, a phosphor 38, a ferrule 60 as a holding member that holds the phosphor 38 and the optical fiber 37A, and a phosphor. A cylindrical sleeve member 61 that covers the outer periphery of the sleeve 38 and a protective cover 36 that seals the tip of the sleeve member 61. The illumination optical system unit 26B includes an optical fiber 37B, a phosphor 38, a ferrule 60, a sleeve member 61, and a protective cover 36. Like the illumination optical system unit 26A, the ferrule 60 is composed of the phosphor 38. The sleeve member 61 covers the outer periphery of the phosphor 38, and the protective cover 36 seals the tip of the sleeve member 61. The outer peripheral surfaces of the optical fibers 37A and 37B are covered with a protective tube 62 (see FIG. 2). The distal end portion of the protective tube 62 is fixed to the outer peripheral surface of the sleeve member 61.

  The ferrule 60 is made of metal, ceramic, or the like, is formed in a substantially cylindrical shape, and has an insertion hole 65 through which the optical fiber 37A is inserted. A phosphor holder 66 that holds the phosphor 38 is formed on the tip side of the ferrule 60. The phosphor holding portion 66 is formed in a concave shape from the tip surface 60 a of the ferrule 60 according to the outer shape of the phosphor 38, and the tip side facing the protective cover 36 is opened. The insertion hole 65 is continuous with the proximal end of the phosphor holder 66.

  A reflection film 67 is provided on the surface of the phosphor holder 66. The reflective film 67 is made of a metal film such as silver or aluminum, and is formed into a thin film by, for example, plating, vapor deposition, or sputtering. The phosphor 38 is held inside the phosphor holder 66 while being in contact with the reflective film 67. The illumination light emitted from the phosphor 38 is reflected by the reflection film 67 and can be used efficiently. When the phosphor 38 is held by the phosphor holder 66, the tip surfaces of the phosphor 38 and the reflective film 67 are formed so as to be flush with the tip surface 60 a of the ferrule 60. The insertion hole 65 is formed along the central axis of the ferrule 60. The tip of the optical fiber 37A is fitted into the insertion hole 65 and is held behind the phosphor 38.

  The sleeve member 61 is made of a metal such as stainless steel, and is formed in a substantially cylindrical shape having a receiving portion 70 that receives the protective cover 36 and a fitting hole 71 into which the outer peripheral surface 60b of the ferrule 60 is fitted in order from the tip side. Has been. The receiving part 70 has an inner diameter larger than that of the fitting hole 71. The receiving portion 70 has an inner peripheral surface 70 a that faces the outer peripheral surface 36 a of the protective cover 36, and a bottom surface 70 b that intersects the inner peripheral surface 70 a and faces the base end surface 36 b of the protective cover 36. By adhering the protective cover 36 to the receiving portion 70, the tip of the sleeve member 61 is sealed. The fitting hole 71 is continuous from the bottom surface 70 b to the rear end surface of the sleeve member 61 along the center of the sleeve member 61.

  The protective cover 36 transmits illumination light (white light) emitted from the phosphor 38, that is, blue laser light transmitted while diffusing the phosphor 38 and green to yellow fluorescence excited and emitted from the phosphor 38. It is formed in a substantially disc shape from possible materials. The protective cover 36 is made of, for example, quartz glass or sapphire glass.

  As shown in FIGS. 5 and 6, a plurality of circumferential grooves 75 are formed on the bottom surface 70 b of the receiving portion 70. The circumferential groove 75 is arranged concentrically with the bottom surface 70 b of the receiving portion 70 and the fitting hole 71. The circumferential grooves 75 may be arranged at predetermined intervals on the bottom surface 70b or may be arranged at random intervals. The circumferential groove 75 is formed in a wedge-shaped cross section whose width gradually decreases from the distal end side toward the proximal end side.

  When the protective cover 36 is bonded to the receiving portion 70 in order to seal the tip of the sleeve member 61, the gap between the receiving portion 70 and the protective cover 36, that is, the inner peripheral surface 70 a of the receiving portion 70 and the protective cover 36. Adhesive 72 is poured into between the outer peripheral surface 36a. As the adhesive 72 used for bonding the protective cover 36 and the receiving portion 70, for example, a silicon-based adhesive is used. Further, when the viscosity of the adhesive 72 is low, glass beads may be mixed into the adhesive 72. When the adhesive 72 mixed with glass beads is used, the glass beads enter so as to fill a gap formed between the outer peripheral surface 36a of the protective cover 36 and the inner peripheral surface 70a of the receiving portion 70. Suppress. Further, since the adhesive 72 mixed with glass beads appears white, the filling state of the adhesive 72 can be easily visually confirmed.

  As shown in FIG. 7, part of the adhesive 72 poured between the inner peripheral surface 70a of the receiving portion 70 and the outer peripheral surface 36a of the protective cover 36 enters between the base end surface 36b and the bottom surface 70b. In this case, since the circumferential groove 75 is formed on the bottom surface 70b, the adhesive 72 is easy to flow along the circumferential groove 75, and the outer circumferential groove 75 is almost full, The adhesive 72 flows into the inner circumferential groove 75. That is, the adhesive 72 that has entered between the base end surface 36b and the bottom surface 70b has a slower flow rate in the radial direction than the flow rate in the circumferential direction of the bottom surface 70b. Thereby, the amount of the adhesive 72 poured into the gap between the receiving portion 70 and the protective cover 36 can flow from the outside to the inside of the bottom surface 70b.

  In the manufacturing process for manufacturing the illumination optical system unit 26 </ b> A having the above-described configuration, first, in order to seal the tip of the sleeve member 61, an adhesion process for bonding the protective cover 36 to the receiving portion 70 is performed. When performing this bonding step, the operator first holds the protective cover 36 on the receiving portion 70. As shown in FIG. 8A, when the protective cover 36 is held on the receiving portion 70, the base end surface 36 b of the protective cover 36 is in contact with the bottom surface 70 b of the receiving portion 70.

  And while maintaining the state in which the protective cover 36 is held by the receiving portion 70, the gap between the receiving portion 70 and the protective cover 36, that is, between the inner peripheral surface 70 a of the receiving portion 70 and the outer peripheral surface 36 a of the protective cover 36. Adhesive 72 is poured into. When the adhesive 72 is poured, a sufficient amount of the adhesive 72, that is, an amount slightly exceeding the volume between the inner peripheral surface 70a and the outer peripheral surface 36a is poured.

  As shown in FIG. 8 (B), the amount of the adhesive 72 exceeding the volume between the inner peripheral surface 70a and the outer peripheral surface 36a is poured into the space between the inner peripheral surface 70a and the outer peripheral surface 36a. The adhesive 72 is filled over the entire circumference, and a part of the adhesive 72 enters between the bottom surface 70 b of the receiving portion 70 and the base end surface 36 b of the protective cover 36. The protective cover 36 is lifted from the bottom surface 70b by the amount of the adhesive 72 that has entered between the bottom surface 70b and the base end surface 36b (moves toward the front end side). Since the circumferential groove 75 is formed on the bottom surface 70b, the amount of the adhesive 72 that has entered between the receiving portion 70 and the protective cover 36 flows from the outside to the inside of the bottom surface 70b can be suppressed. Thereby, it is possible to prevent the adhesive 72 from entering the fitting hole 71.

  After the bonding step, the ferrule 60 holding the phosphor 38 and the optical fiber 37A is inserted into the sleeve member 61, and the phosphor 38, the ferrule 60, and the reflective film 67 are brought into close contact with the protective cover 36. Then, the ferrule 60 is held by the sleeve member 61 in a state where the phosphor 38, the ferrule 60, and the reflective film 67 are inserted into the protective cover 36 until they are in close contact with each other. In order to hold the ferrule 60 on the sleeve member 61, the fitting between the fitting hole 71 and the outer peripheral surface 60b of the ferrule 60 is set to be an interference fit, and when the ferrule 60 is pushed into the sleeve member 61, It can be fixed. The ferrule 60 may be held on the sleeve member 61 by means such as bonding or screwing.

  As described above, when the adhesive 72 is poured into the gap between the receiving portion 70 and the protective cover 36, the adhesive 72 is filled over the entire circumference, and from the outside of the bottom surface 70 b to the inside by the circumferential groove 75. The amount of the flowing adhesive 72 can be suppressed, and the adhesive 72 can be prevented from entering the fitting hole 71. Therefore, it becomes possible to control the adhesive 72 poured between the protective cover 36 and the sleeve member to an appropriate amount, and workability is improved. Moreover, by mixing glass beads into the adhesive 72, the flow of the adhesive 72 can be further suppressed and the adhesive 72 can be prevented from entering the fitting hole 71.

  In the first embodiment, the circumferential groove 75 is formed only in the receiving portion 70 of the sleeve member 61. However, the present invention is not limited to this, and the illumination optical system unit 80 of the second embodiment shown in FIG. As described above, a plurality of circumferential grooves 81 may also be formed in the protective cover 36. The circumferential groove 81 is formed on the base end surface 36 b of the protective cover 36. The circumferential groove 81 is disposed such that its position is shifted in the radial direction with respect to the circumferential groove 75 so as to mesh with the circumferential groove 75 of the receiving portion 70. In particular, when the circumferential grooves 75 are arranged at predetermined intervals, it is preferable that the circumferential grooves 81 are arranged such that a half position of the predetermined intervals is shifted in the radial direction with respect to the circumferential grooves 75. Thereby, when the adhesive 72 enters between the bottom surface 70b of the receiving portion 70 and the base end surface 36b of the protective cover 36, the flow in the radial direction of the bottom surface 70b is suppressed by the circumferential groove 75 and the circumferential groove 81. Therefore, it becomes possible to control the amount of the adhesive 72 flowing from the outside to the inside of the bottom surface 70b with higher accuracy.

  In the above embodiments, the cross-sectional shape of the circumferential grooves 75 and 81 has been described by taking a wedge-shaped cross-sectional shape as an example. . Further, the number and size of the circumferential grooves 75 and 81 are appropriately determined depending on the viscosity of the adhesive 72, the size of the bottom surface 70b of the receiving portion 70, and the like.

  In each of the above embodiments, the ferrule is fitted to the sleeve member while the phosphor is held by the ferrule as the holding member, and the outer periphery of the phosphor is covered with the sleeve member. However, the present invention is not limited to this. Instead, the phosphor may be directly held by the sleeve member.

  Further, in each of the above embodiments, an electronic endoscope that observes an image obtained by imaging the state of the subject using an imaging element is described as an example, but the present invention is not limited to this, The present invention can also be applied to an endoscope that employs an optical image guide to observe the state of a subject. Furthermore, in the above embodiment, an endoscope provided with two illumination optical system units has been described as an example. However, the present invention is not limited thereto, and an endoscope provided with one illumination optical system unit is described. The present invention can also be applied to an endoscope or an endoscope provided with three or more illumination optical system units.

DESCRIPTION OF SYMBOLS 11 Electronic endoscope system 12 Electronic endoscope 13 Processor apparatus 14 Light source device 16 Insertion part 16a Tip part 26A, 26B, 80 Illumination optical system unit 33 CCD
36 Protective cover 37A, 37B Optical fiber 38 Phosphor 60 Ferrule (holding member)
61 Sleeve member 65 Through-hole 66 Phosphor holding portion 67 Reflective film 70 Receiving portion 71 Fitting hole 72 Adhesive 75, 81 Circumferential groove

Claims (6)

An optical fiber that guides and emits laser light supplied from a laser light source to the tip;
A phosphor that emits fluorescence when excited by laser light emitted from the optical fiber, and forms a white light composed of the fluorescence and the laser light; and
A protective cover that covers the front end side of the phosphor and transmits the fluorescence and the laser beam;
A sleeve member that covers the outer periphery of the phosphor and has a receiving portion that holds the protective cover on the tip side, and an adhesive is poured between the receiving portion and the protective cover, and a sleeve member that seals the tip. Prepared,
An endoscope illumination optical system unit, wherein the sleeve member is formed with a plurality of circumferential grooves arranged concentrically in the receiving portion.   The receiving portion includes an inner peripheral surface that faces the outer peripheral surface of the protective cover, and a bottom surface that intersects the inner peripheral surface and faces the end surface of the protective cover, and the circumferential groove is formed on the receiving portion. The endoscope illumination optical system unit according to claim 1, wherein the illumination optical system unit for an endoscope is formed on the bottom surface.   The protective cover is formed with a plurality of circumferential grooves disposed on an end surface facing the bottom surface, the positions being shifted in a radial direction with respect to the circumferential groove formed in the receiving portion. The endoscope illumination optical system unit according to claim 2.   The endoscope illumination optical system unit according to any one of claims 1 to 3, wherein the adhesive is a silicon-based adhesive.   The endoscope illumination optical system unit according to any one of claims 1 to 4, wherein the adhesive is mixed with glass beads. An optical fiber that guides and emits laser light supplied from a laser light source to the tip, and a phosphor that emits fluorescence by being excited by the laser light emitted from the optical fiber, and is a white color composed of the fluorescence and the laser light A phosphor that forms light, a protective cover that covers a front end side of the phosphor, transmits the fluorescent light and the laser light, and a receiving unit that covers an outer periphery of the phosphor and holds the protective cover on the front end side A sleeve member in which an adhesive is poured between the receiving portion and the protective cover and the tip is sealed, and a plurality of circumferential grooves arranged concentrically on the receiving portion are formed. In the manufacturing method of an illumination optical system unit for an endoscope provided with a sleeve member,
Pouring an adhesive between the sleeve member and the protective cover, and sealing the tip of the sleeve member with the protective cover;
Inserting the phosphor and the optical fiber into the sleeve member from the base end side of the sleeve member, the tip of which is sealed with the protective cover, and bringing the phosphor into close contact with the protective cover;
A step of holding the phosphor and the optical fiber on the sleeve in a state where the phosphor is brought into close contact with the protective cover and the optical fiber is disposed on a proximal end side of the phosphor. A method of manufacturing an endoscope illumination optical system unit.