JP4538297B2 - Endoscope - Google Patents

Description

  The present invention relates to a cover glass that is attached to the tip of the endoscope in order to protect the observation system of the endoscope, and an endoscope that includes such a cover glass.

Some observation systems for endoscopes inserted into body cavities include a cover glass for preventing foreign substances from entering the endoscope or intrusion of cleaning liquid (for example, Patent Document 1 and Patent Document 2).
Japanese Utility Model Publication 2-38249 No. 2-19774

  The cover glass as disclosed in Patent Document 1 is usually bonded to the adhesive surface of the holding frame with an adhesive applied to the edge surface (side surface). Since such an edge surface is a groove surface, an anchor effect is generated, and the adhesive strength at the interface between the groove surface and the holding frame is high. The ground surface is a surface having a relatively large surface roughness, which is different from a surface through which light is transmitted and is not polished to obtain optical performance, or is intentionally roughened. It is a surface. Moreover, the cover glass shown by the said patent document 2 is being fixed to the endoscope front-end | tip part by the periphery part being pinched | interposed into a frame.

  However, in the method of fixing the cover glass as shown in the above-mentioned Patent Document 1, since the bonding area is small, the adhesive strength between the holding frame and the cover glass is improved even when the ground surface is the bonding surface as described above. Cannot secure enough. Moreover, in the fixing method of a cover glass as shown by the said patent document 2, a big space is required for arrange | positioning the fixing structure for pinching | interposing a cover glass. As a result, the endoscope distal end is enlarged.

  Therefore, in view of the above circumstances, the present invention has an object to provide a cover glass that can ensure sufficient adhesive strength without increasing the size of the endoscope tip and an endoscope including such a cover glass. To do.

  The cover glass according to one embodiment of the present invention that solves the above problem is attached to an endoscope whose tip is applied to the object when observing the object, and applied to the object A central region including at least an effective diameter that is optically effective, and a second surface that is a flat surface located on a back side of the first surface. And a peripheral region having a rougher surface than the central region.

  When the cover glass is formed in this way, the area on the cover glass that can be expected to have an anchor effect in bonding with the endoscope increases (that is, the area that can be used for bonding with the endoscope increases), so that sufficient bonding is achieved. It is possible to ensure strength. Moreover, since such a configuration can be realized even with a thin cover glass, the endoscope distal end portion is not enlarged.

  The cover glass may further have an edge surface having a rougher surface than the center region. Further, in the central region, at least the entire effective diameter may be coated with an antireflection film.

  Further, the cover glass according to one embodiment of the present invention that solves the above problem is for protecting the endoscope interior from another viewpoint, and the surface disposed on the image side is a plane, It has a central region including at least an effective diameter which is optically effective, and a peripheral region whose surface is rougher than the central region.

  In addition, an endoscope according to one aspect of the present invention that solves the above problem includes an observation system in which a distal end portion of the endoscope is applied to the object when the object is observed. A cover glass having a first surface to be applied and a second surface which is a flat surface located on the back surface thereof, and a holding frame for holding the cover glass formed with the first adhesive surface bonded to the second surface are provided. It is a thing. The endoscope is characterized in that, on the second surface, the surface of the region bonded to the first bonding surface is rougher than the surface of the central region including at least an effective diameter that is optically effective. .

  When the endoscope is configured in this way, the bonding area is larger than that of the conventional one, and the anchor effect is generated over the entire bonding interface, so that the bonding strength is increased.

  In the endoscope, when the cover glass has an edge surface and the holding frame has a second adhesive surface bonded to the edge surface, the edge surface is finished to be rougher than the surface of the central region. It may be. Further, in the central region, at least the entire effective diameter may be coated with an antireflection film for preventing internal reflection that may occur in the observation system provided therein. The observation system may include a confocal optical system for performing confocal observation.

  Moreover, the endoscope which concerns on 1 aspect of this invention which solves said subject WHEREIN: In another viewpoint, the cover surface for protecting the inside and the adhesion surface adhere | attached with a part of the said cover glass are formed. The cover glass is provided with a holding frame for holding the cover glass, and the cover glass is a surface disposed on the image side, and a part of the surface is bonded to the bonding surface. The surface of the region bonded to the bonding surface is rougher than the surface of the central region including at least an effective optically effective diameter.

  When the cover glass and the endoscope of the present invention are employed, a large bonding area between the cover glass and the holding frame can be secured, so that sufficient adhesive strength can be ensured. In addition, since the anchor effect is generated over the entire bonded surface, the bonding strength is further increased. In this case, since the fixing structure as shown in Patent Document 2 is not used, the distal end portion of the endoscope is not enlarged.

  The cover glass according to the embodiment of the present invention is provided in a confocal optical system for performing confocal observation described later, and has a higher adhesive strength than the cover glass provided in a conventional endoscope. It can be bonded to the distal end portion of the endoscope. Below, with reference to drawings, the cover glass of this embodiment and the endoscope provided with the cover glass are explained.

  FIG. 1 is a diagram illustrating an appearance of an electronic endoscope 100 according to the present embodiment. As shown in FIG. 1, the electronic endoscope 100 of the present embodiment includes an insertion portion flexible tube 101 that is a long tube that is inserted into a body cavity and has flexibility. The distal end of the insertion portion flexible tube 101 is provided with a distal end portion main body 101t in which an optical unit or the like is incorporated.

  The electronic endoscope 100 also includes a forceps insertion port 102 for inserting forceps for performing various treatments such as hemostasis and collection of living tissue. A channel through which forceps is inserted is formed along the longitudinal direction inside the insertion portion flexible tube 101, and an opening of the channel is formed in the distal end portion main body 101t. Therefore, when the forceps are set in the forceps insertion slot 102, the tip portion protrudes from the opening of the tip portion main body 101t. Thereby, the surgeon can perform various treatments using forceps on the surgical site.

  The electronic endoscope 100 includes an operation unit 103 for performing various operations. A plurality of knobs and buttons are arranged on the operation unit 103, and by operating these knobs, for example, the operator changes the direction of the front surface of the distal end portion body 101t by bending the vicinity of the root portion of the distal end portion body 101t. The observation area can be changed, and air or water can be supplied to clean the body cavity.

  Although not shown in its entirety, the tube extending from the operation unit 103 in a direction different from that of the insertion unit flexible tube 101 is connected to a processor (not shown) including a light source and an image processing unit. Yes.

  FIG. 2 is a cross-sectional view of the insertion portion flexible tube 101 of the present embodiment, and mainly shows a cross section of the distal end portion main body 101t. Two cylindrical openings (cavities) with different diameters are formed in the tip end body 101t. In each cavity, a cylindrical confocal observation unit 10 and a normal observation unit 50 having diameters corresponding to the respective diameters are incorporated. These two units are optical units for observing living tissue in the body cavity, and the confocal observation unit 10 is for observing the surface portion and tomographic portion of the living tissue at a higher magnification than the normal observation unit 50. It is. In FIG. 2, the longitudinal direction of the tip body 101t is defined as the Z direction, the direction orthogonal to the Z direction and parallel to the paper surface is defined as the Y direction, and the direction orthogonal to the paper surface is defined as the X direction.

  The normal observation unit 50 includes a normal observation objective optical system 51 and an image sensor 52. Here, generation of an observation image by the normal observation unit 50 will be briefly described. First, when the illumination light emitted from the light source of the processor illuminates the observation target via a light guide (not shown), the reflected light from the observation target enters the normal observation objective optical system 51. The incident light is imaged on the light receiving surface of the image sensor 52 by the power of the normal observation objective optical system 51. The optical image formed on the light receiving surface of the image sensor 52 is accumulated as a charge corresponding to the amount of light in each light receiving element arranged on the light receiving surface and converted into an image signal of the living tissue. The converted image signal is transmitted to the processor by an electric cable wired inside the electronic endoscope 100. The processor performs image processing and outputs the image to a monitor (not shown). As a result, an image to be observed is displayed on the monitor. The normal observation unit 50 has a lower magnification than the confocal observation unit 10 and is used when it is desired to observe the surface portion of the living tissue over a relatively wide range.

  Next, the confocal observation unit 50 will be described. The confocal observation unit 10 includes a light emitting unit 11, a confocal objective optical system 12, a lens barrel 13, a tip frame 14, a cover glass 15, a main body frame 16, and an inner tube 17.

  The light emitting unit 11 includes a single mode optical fiber 11A and piezoelectric elements 11B and 11C. The single mode optical fiber 11A guides the laser light emitted from the laser light source provided in the processor. The piezoelectric elements 11B and 11C are installed in the vicinity of the end surface 11t of the single mode optical fiber 11A, and displace the end surface 11t in a predetermined direction.

  The confocal objective optical system 12 is disposed in front of the end surface 11 t and is held by the lens barrel 13. The lens barrel 13 is held by the distal end frame 14 so as to be slidable in the Z direction. The distal end frame 14 has a diameter equivalent to that of the opening (cavity) for the confocal observation unit 10 formed in the distal end portion main body 101t, and is fixed thereto. A cover glass 15 that is a plane parallel plate is bonded to the front surface of the front end frame 14. The confocal objective optical system 12 is actually composed of a number of lenses, but only two are shown in FIG. 2 for convenience.

  The main body frame 16 also has a diameter equivalent to that of the opening (cavity) and is fixed thereto. For this reason, the main body frame 16 and the front end frame 14 are in a relatively fixed state. Further, the inner tube 17 is provided such that the outer skin thereof is in contact with the inner wall of the main body frame 16 over the entire area. The inner tube 17 is fixed to the lens barrel 13 and can slide in the Z direction with respect to the main body frame 16.

  The confocal observation unit 10 is a unit for performing confocal observation, and its optical system is designed to have a high NA. For this reason, when observing using the confocal observation unit 10, it becomes possible to observe the inside of the living tissue which is a dark part with high magnification. The confocal observation unit 10 is configured to be small in order to reduce the diameter of the tip body 101t.

  In addition, the observation method using the confocal observation unit 10 is different from the normal observation method (that is, the observation method using the normal observation unit 50), and is the first surface that is the object side surface of the cover glass 15 disposed on the front surface thereof. Observation is performed with the surface 151 applied to the living tissue. For this reason, the confocal observation unit 10 is incorporated so as to protrude a predetermined amount from the normal observation unit 50 in the tip end body 101t.

  The operation of the confocal observation unit 10 will be outlined. First, laser light is emitted from the laser light source of the processor. The laser light is incident on the end portion of the single mode optical fiber 11 </ b> A in the insertion portion flexible tube 101. The laser light incident on the end portion is transmitted through the single mode optical fiber 11A and emitted from the end face 11t of the fiber. The light beam emitted from the end face 11t is focused on the living tissue 400 by the power of the confocal objective optical system 12 through the confocal objective optical system 12 and the cover glass 15.

  The light beam focused on the biological tissue 400 is reflected or emitted by the biological tissue 400, and near the end surface 11 t by the power of the confocal objective optical system 12 through the cover glass 15 and the confocal objective optical system 12. Focus. The end face 11t is conjugate with the position where the light beam emitted from the confocal objective optical system 12 is focused on the living tissue 400. Further, the core diameter of the single mode optical fiber 11A is extremely small. Accordingly, of the reflected light or fluorescence from the living tissue 400, only the component focused on the living tissue 400 is incident on the inside of the single mode optical fiber 11A, and the other light is the clad portion of the single mode optical fiber 11A. It will be shielded from light. That is, the light incident on the end face 11t is only the component focused on the living tissue 400.

  The reflected light guided to the processor by the single mode optical fiber 11A is processed by the processor and converted into a video signal. The converted video signal is displayed on the monitor as an observation image by the confocal objective optical system 12 or recorded on a recording device.

  Here, the piezoelectric element 11B disposed in the vicinity of the end face 11t is deformed by applying a voltage, and presses the single mode optical fiber 11A in the X direction. Similarly, the piezoelectric element 11C disposed in the vicinity of the end face 11t is deformed when a voltage is applied, and presses the single mode optical fiber 11A in the Y direction. Thereby, the end surface 11t is displaced in the X direction or the Y direction. Note that the end face 11t is positioned substantially at the center of the confocal observation unit 10 (in other words, substantially on the same line as the optical axis of the confocal objective optical system 12) when not pressed by the piezoelectric elements 11B and 11C.

  When the end surface 11t is displaced in the X direction or the Y direction, the focal position of the light beam applied to the living tissue 400 also moves with the displacement of the end surface 11t. In other words, the light beam applied to the living tissue 400 scans the surface or the inside of the living tissue 400 in the X direction or the Y direction in accordance with the displacement of the end surface 11t. Thus, an image for obtaining a two-dimensional observation image defined by the X direction and the Y direction is transmitted from the confocal observation unit 10 to the processor.

  Note that the confocal observation unit 10 is configured so that the focal position on the living tissue 400 can be moved minutely in the optical axis direction (Z direction) of the confocal objective optical system 12. Members arranged inside the unit, such as the optical system 12, are integrated and slidable in the Z direction by an actuator (not shown). Here, as described above, the distal end frame 14 and the main body frame 16 are fixed to the opening (cavity), and the lens barrel 13 and the inner tube 17 are configured to be slidable in the Z direction with respect to them. When the actuator is driven, the lens barrel 13 and the inner tube 17 slide in the Z direction with respect to the tip frame 14 and the main body frame 16.

  Here, the front end frame 14 is a molded part molded from, for example, ABS resin, and the cover glass 15 is a glass part formed from, for example, BK7. Since these parts are formed of resin or glass, sufficient adhesive strength cannot be ensured even if these parts are bonded with an adhesive. Therefore, conventionally, the edge surface (side surface), which is the adhesive surface on the cover glass side, is a slit surface, and an anchor effect is produced at the interface between the cover glass and the holding frame (corresponding to the tip frame 14 of the present embodiment). The adhesive strength was improved. However, it still cannot be said that sufficient adhesive strength has been secured. Therefore, in the confocal observation unit 10 of the present embodiment, the cover glass 15 is configured so as to ensure sufficient adhesive strength, as will be described in detail below.

  FIG. 3 is a view showing the cover glass 15 of the present embodiment, FIG. 3 (a) is a cross-sectional view across the center of the cover glass 15, and FIG. 3 (b) is an observation of a surface arranged on the image side. It is a figure to do. FIG. 4 is a view for explaining attachment of the cover glass 15 and the tip frame 14. Below, with reference to FIG.3 and FIG.4, the cover glass 15 of this embodiment is demonstrated. In FIG. 3 and FIG. 4, the slit surface is indicated by a bold line for convenience.

  As shown in FIG. 3, the cover glass 15 is a plane parallel plate and has a cylindrical shape with a low height. In addition, it has a first surface 151 facing the object side when attached to the confocal observation unit 10, a second surface 152 facing the image side, and an edge surface 153 orthogonal to the first surface 151 and the second surface 152. is doing.

  The first surface 151 is a surface that has the appearance of the tip body 101t and transmits light for confocal observation, and is thus polished over the entire area. Further, the edge surface 153 is a slit surface in order to produce an anchor effect during bonding. The second surface 152 is a surface through which light for confocal observation is transmitted. However, the second surface 152 is a partially ground surface in order to increase the adhesive strength between the cover glass 15 and the tip frame 14.

  The second surface 152 is a central region 152a having the same surface roughness as the first surface 151, and a region surrounding the central region 152a, and has a surface roughness equivalent to the edge surface 153 (that is, a ground surface). A peripheral region 152b having a larger surface roughness than the central region 152a. In other words, the second surface 152 includes an optically effective surface (a polished surface or a surface with a low surface roughness) and a ground surface (a surface that has been roughened, or a surface roughness) on the same plane. High surface).

The central region 152a is a region coated with an antireflection film for preventing internal reflection that may occur in the confocal observation unit 10, and an optically effective effective diameter (all light rays are transmitted within this effective diameter). ) At least. Further, the coating region is designed to include at least an effective diameter. The central region 152a, the coating region, and the effective diameter are substantially concentric circles, the center of which is substantially equal to the center of the cover glass 15. Here, the diameter of the central region 152a and .phi.n _1, the diameter of the coating area are .phi.n _2, if the diameter of the effective diameter is _{φn 3, n 1 ≧ n 2} ≧ n 3 is satisfied.

Ideally, n ₁ = n ₂ = n ₃ , but in the cover glass 15 of the present embodiment, each region is designed with n ₁ > n ₂ > n ₃ in consideration of manufacturing errors.

  Here, as shown in FIG. 4, the front end frame 14 is formed with an adhesive surface 142 corresponding to the peripheral region 152 b in addition to the adhesive surface 141 corresponding to the edge surface 153. Therefore, when the cover glass 15 is attached to the front end frame 14, these parts are bonded to each other at the edge surface 153 and the bonding surface 141, and the peripheral region 152 b and the bonding surface 142. Therefore, the bonding area is larger than the conventional one, and the bonding strength is increased. Furthermore, since the peripheral region 152b is a groove surface as well as the edge surface 153, an anchor effect occurs at the interface between the peripheral region 152b and the adhesive surface 142, and the adhesive strength is increased.

  Note that the edge formed by the first surface 151 and the edge surface 153 is chamfered to remove burrs. On the other hand, the edge portion formed by the second surface 152 and the edge surface 153 is not chamfered in order to secure a bonding area as much as possible. Thus, in this embodiment, the adhesive strength is further increased by intentionally not chamfering.

  In addition, when the tip frame 14 is formed so that the surface roughness of the adhesive surface 141 and the adhesive surface 142 is increased, the components are more complicated and bonded at the interface with the edge surface 153 and the peripheral region 152b. A higher anchor effect is expected.

  Here, since the antireflection film may be peeled off when the antireflection film is immersed in a chemical solution (including a cleaning solution), the operator needs to accurately identify the front and back sides of the cover glass during assembly. In this regard, in the cover glass 15 of the present embodiment, the front and back sides can be easily identified by the presence of the peripheral region 152b (scratch surface). Therefore, it is not necessary to attach front / back identification marks to the cover glass 15 and it is not mistakenly attached to the front end frame 14.

  The above is the embodiment of the present invention. The present invention is not limited to these embodiments and can be modified in various ranges.

  For example, in this embodiment, a ground surface is formed on the second surface 152, but in another embodiment, a ground surface may be formed on the first surface 151. This is effective when the adhesive surface on the front end frame 14 side is formed so as to cover the peripheral portion of the first surface 151. The first surface 151 can be formed with a ground surface in all regions other than the effective diameter.

It is a figure showing appearance of an electronic endoscope of an embodiment of the invention. It is sectional drawing of the insertion part flexible tube of embodiment of this invention, and mainly shows the cross section of a front-end | tip part main body. It is a figure which shows the cover glass of embodiment of this invention. It is a figure for demonstrating attachment with the cover glass and front-end | tip frame of embodiment of this invention.

Explanation of symbols

10 confocal observation unit 14 tip frame 15 cover glass 100 electronic endoscope 101t tip body 151 first surface 152 second surface 152a central region 152b peripheral region 153 edge surface

Claims (4)

  An objective optical system;
  The surface facing the objective optical system is a central region including the effective diameter of the objective optical system, and a cover glass composed of a peripheral region having a rougher surface roughness than the central region,
  A holding frame to which the cover glass is bonded and fixed, and a holding frame having a roughened bonding surface with the edge surface of the cover glass and the peripheral region;
Have
  An endoscope according to claim 1, wherein the cover glass has a non-chamfered edge portion formed by the edge surface and the facing surface. The endoscope according to claim 1 , wherein the edge surface is rougher than the central region. In the central region, at least the effective径全zone, endoscopic according the the coated antireflection film for preventing internal reflection may occur in the objective optical system, to claim 1 or claim 2, wherein mirror. The endoscope according to any one of claims 1 to 3 , wherein the objective optical system includes a confocal optical system for performing confocal observation.

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