JP2011056106A - Visual-field switching adapter for endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual-field switching adaptor for an endoscope, which enables an endoscopic observation in a plurality of visual fields without lowering resolution by being attached to a leading end of the endoscope. <P>SOLUTION: The visual-field switching adaptor for the endoscope has an optical element capable of obtaining a penetration state and a reflection state. By changing the state of the optical element, a first light path forming an image of a first visual field and a second light path forming an image of a second visual field are switched over. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an endoscope adapter that is attached to a distal end portion of an endoscope and adds a function to the endoscope, and more particularly to an endoscope visual field switching adapter that enables observation by switching a plurality of visual fields.

  Conventionally, endoscopes are widely used in medical and industrial fields in order to perform observation and treatment in a narrow space such as in a body cavity. In recent years, as endoscopes such as CCD image sensors and CMOS image sensors have become smaller and higher in performance, electronic endoscopes in which a solid-state image sensor is mounted at the distal end of an insertion portion have been rapidly spread. A general electronic endoscope has a glass plate (optical aperture), an objective lens, and a solid-state image sensor in the longitudinal direction along the optical axis at the distal end of a flexible and slender cable-shaped insertion portion. It is arrange | positioned in a line toward, and it is comprised so that the area | region ahead of the insertion part front-end | tip can be observed. However, when observing organs with a large number of folds such as the small intestine, for example, a blind spot is formed on the back side of the fold, so that there are cases where sufficient observation cannot be performed only by forward observation. Therefore, an endoscope attachment has been proposed that enables simultaneous observation of the front visual field and the side visual field by attaching to the distal end of the endoscope as described in Patent Document 1. The endoscope attachment described in Patent Document 1 has a hyperboloid convex mirror with an opening formed in the center, and an image of the front field of view at the tip of the endoscope passes through the opening of the convex mirror to the center of the imaging surface. An image is formed, and the image of the side field is reflected by the convex mirror and formed on the imaging surface around the image of the front field. Therefore, the front view and the side view are simultaneously displayed on one screen, and the front view and the side view can be performed simultaneously.

  In the technical field of window materials used for buildings and vehicles, various so-called “light control glasses” that control sunlight transmitted through window glass have been proposed. The light control glass includes an absorption light control glass that performs light control by absorbing light and a light control mirror that performs light control by reflection of light (reflective light control glass). In the dimming mirror, a film having a property that the reflectance continuously and reversibly changes between a mirror state having a high reflectance and a transparent state having a low reflectance and a high transmittance is formed on a transparent substrate. (Patent Document 2).

WO2006-004083 Japanese Patent Application No. 2005-274630

  By the way, in the medical electronic endoscope, it is important to make the insertion portion of the electronic endoscope small in diameter so that the subject can receive an endoscopic examination without pain. One of the main factors that determine the outer diameter of the electronic endoscope is the external dimension of the solid-state imaging device, particularly the size of the imaging surface. For this reason, the size of the imaging surface of the solid-state imaging device used in the electronic endoscope is strictly limited, and therefore the number of effective pixels of the solid-state imaging device is also limited. In the endoscope apparatus described in Patent Document 1, since the front observation image and the rear observation image are divided into regions on the imaging surface of the solid-state imaging device having a limited number of effective pixels, There is a problem that the resolution or viewing angle is lowered.

  The present invention has been made in view of the above circumstances. That is, an object of the present invention is to provide an endoscope adapter that allows a plurality of fields of view to be observed without lowering the resolution or the angle of view by being attached to the distal end of the endoscope.

  In order to solve the above problems, the present invention provides an endoscope visual field switching adapter that is attached to the distal end of an endoscope and enables observation of a plurality of visual fields. The endoscope visual field switching adapter includes an optical element that can be in a transmission state and a reflection state, and by changing the state of the optical element, a first optical path that forms an image of the first visual field, and a second optical path The second optical path for forming the field image is switched.

  According to the above configuration, since it is possible to observe by switching a plurality of fields of view, it is not necessary to share a limited imaging region for each field of view, and each field of view can be observed with a wide angle of view or high resolution. it can.

  In one embodiment of the present invention, when the optical element is in the transmissive state, an image of the first visual field is formed by the first optical path that passes through the optical element, and when the optical element is in the reflective state, the image is reflected by the optical element. The second optical path forms an image of the second field of view.

  The optical element may have a variable reflectance and switch between a transmissive state and a reflective state according to a change in the reflectance.

  Further, the first field of view may include a front field of view, and the second field of view may include a rear field of view and / or a side field of view. The optical element may be formed such that the reflection surface in the reflection state is suitable for omnidirectional observation. Such a configuration enables endoscopic observation with a small number of blind spots.

  A shape suitable for omnidirectional observation may be a two-leaf hyperboloid. An image obtained by reflecting on a two-leaf hyperboloid can be converted into a planar perspective projection image or a 360-degree panoramic image. For this reason, it becomes possible to observe more accurately when the optical element is in the reflective state.

  The optical element may include a reflectivity variable film. By adopting a film structure in the reflectivity variable portion, an optical element with high transmittance can be obtained.

  The reflectivity variable film may be a metal thin film that changes to a transparent state by hydrogenation and changes to a reflection state by dehydrogenation, for example, a metal thin film containing magnesium such as magnesium metal or a magnesium-nickel alloy.

  The reflectivity variable film may be held in a transparent solid medium. That is, when both surfaces of the reflectivity variable film are brought into close contact with the solid medium, for example, even when the reflectivity variable film is formed in a curved surface, the reflectivity variable film has substantially a refractive power with respect to transmitted light. In addition, the image formed by the transmitted light is not distorted or enlarged / reduced. The solid medium may be optical glass or optical resin.

  Moreover, it is desirable that the endoscope field-of-view switching adapter can be attached to and detached from the distal end of the endoscope. By making it detachable, the versatility of the endoscope and endoscope visual field switching adapter can be enhanced, and medical resources can be effectively utilized.

  The endoscope visual field switching adapter further includes a pair of electrodes that can be inserted into a pair of terminal holes formed at the distal end of the endoscope, and can receive power from the endoscope via the pair of electrodes. It may be configured. The endoscope field-of-view switching adapter configured in this way achieves fixing to the distal end of the endoscope and power feeding simultaneously by a simple mechanism of inserting electrodes into the terminal holes.

  For example, each of the pair of electrodes may be a rod-shaped electrode extending in parallel with each other. With such an electrode structure, the processing of the electrode is easy, and the endoscope visual field switching adapter can be attached to the endoscope with a simple operation of simply inserting and removing.

  Each of the pair of electrodes may have a hook that can be engaged with an engaging claw formed in the terminal hole at the tip. With such an electrode structure, the endoscope visual field switching adapter is not easily detached from the distal end of the endoscope during use.

  The endoscope visual field switching adapter may further include an adapter mounting tool for mounting the main body of the endoscope visual field switching adapter at the distal end of the endoscope. The adapter mounting tool includes, for example, a first recessed portion into which the distal end of the endoscope can be inserted, a second recessed portion into which the main body of the visual field switching adapter can be inserted, and a portion facing the exit of the forceps channel of the endoscope. And a groove communicating with the through hole formed in the peripheral edge of the bottom of the first recess.

  The endoscope visual field switching adapter configured as described above can be mounted on various types of endoscopes only by changing the size or shape of the adapter mounting tool. In addition, since the forceps channel of the endoscope can be connected to an external control terminal through a control line, it can be used by being attached to an existing endoscope in which a through hole is not formed in the distal end surface.

  According to the present invention, there is also provided a field-of-view switching endoscope including the endoscope field-of-view switching adapter. This field-of-view switching endoscope includes a control unit that controls the endoscope field-of-view switching adapter. Further, the endoscope has a pair of terminal holes formed at the distal end, and the endoscope visual field switching adapter has a pair of electrodes that engage with the pair of terminal holes. The pair of terminal holes are connected to the control unit and supply a control voltage to the pair of electrodes.

  The endoscope may be an electronic endoscope. In this case, the images of the first and second visual fields are formed on the imaging surface of the imaging element. The endoscope may be a fiberscope having an optical fiber bundle. In this case, the images of the first and second visual fields are formed on the end face of the tip of the optical fiber bundle.

  The present invention also provides an endoscope processor to which the above-described field-of-view switching endoscope can be connected. The endoscope processor converts an omnidirectional observation image captured by the endoscope into a plane perspective projection image or a panoramic image.

  By attaching the visual field switching adapter according to the embodiment of the present invention to the distal end of the endoscope, it becomes possible to switch and observe a plurality of visual fields. According to the field-of-view switching adapter according to the embodiment of the present invention, since images of a plurality of fields of view are not simultaneously displayed on one screen, there is no need to divide a display area and assign the images to a plurality of fields of view. Multiple fields of view can be observed without dropping the corners.

It is a disassembled side view which shows the external appearance of the endoscope apparatus equipped with the visual field switching adapter according to the embodiment of the present invention. 1 is a block diagram showing a schematic configuration of an endoscope apparatus equipped with a visual field switching adapter according to an embodiment of the present invention. It is a figure explaining mounting | wearing to the endoscope front-end | tip of the visual field switching adapter which concerns on 1st Embodiment of this invention. It is a longitudinal cross-sectional view which shows schematic structure of the visual field switching adapter which concerns on 1st Embodiment of this invention. It is a cross-sectional view which shows schematic structure of the visual field switching adapter which concerns on 1st Embodiment of this invention. It is a figure explaining the schematic structure of the variable optical element in embodiment of this invention. It is a figure explaining switching of the optical path by the visual field switching adapter which concerns on embodiment of this invention. It is a disassembled perspective view which shows schematic structure of the 1st modification of 1st Embodiment of this invention. It is a figure explaining schematic structure of the 2nd modification of 1st Embodiment of this invention, and the mounting | wearing to the endoscope front-end | tip. It is a longitudinal cross-sectional view which shows schematic structure of 2nd Embodiment of this invention. It is a top view which shows the external appearance of the mounting member in 2nd Embodiment of this invention. It is a top view which shows schematic structure of the endoscope apparatus which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a view showing an appearance of an endoscope apparatus 1 to which a visual field switching adapter 50 according to an embodiment of the present invention is attached. FIG. 2 is a block diagram showing a schematic configuration of the endoscope apparatus 1 according to the first embodiment of the present invention. The endoscope apparatus 1 includes an endoscope (electronic scope) 10, a processor 20, a monitor 30, and a visual field switching adapter 50 attached to the distal end of the endoscope 10.

  The endoscope 10 inserts a flexible cable-shaped insertion portion 14 into a body cavity of a subject, and images an observation site in the body cavity with an imaging device provided at the distal end of the insertion portion 14. Unit. The endoscope 10 is divided into a connecting portion 11, a universal cable portion 12, an operating portion 13, and an inserting portion 14 in order from the proximal end side to the longitudinal direction, and is configured to be detachable from the processor 20 via the connecting portion 11. Yes. A visual field switching adapter 50 according to the first embodiment of the present invention is detachably attached to the distal end of the insertion portion 14.

  The endoscope 10 has a light guide (for example, an optical fiber bundle) 15 for propagating illumination light for illuminating the observation region from the light source unit 22 built in the processor 20 to the distal end of the insertion unit 14 in a substantially full length. It is arranged over. The light guide 15 has one line on the proximal end side where the illumination light is incident, but is branched into two lines (15a, 15b) in the middle. Further, a light distribution lens (light distribution optical system) 142 is disposed at the distal end of the insertion portion 14 so as to face each emission end face of the light guide 15. The light distribution lens 142 is configured to diffuse illumination light emitted from the exit end of the light guide and illuminate the observation region substantially uniformly via the visual field switching adapter 50. The visual field switching adapter 50 is a mechanism unit that switches the visual field to be observed. Details of the visual field switching adapter 50 will be described later.

  The illumination light emitted from the visual field switching adapter 50 illuminates a subject (for example, a body cavity inner wall) located in the observation region. A part of the illumination light applied to the inner wall of the body cavity is scattered or reflected by the surface layer of the inner wall of the body cavity and returns to the distal end of the endoscope 10 via the visual field switching adapter 50. An objective lens (objective optical system) 144 is disposed at the distal end of the endoscope 10 so as to face the imaging surface of the CCD image sensor 146. The objective lens 144 is configured to collect return light from the subject and form a subject image on the imaging surface of the CCD image sensor 146. The objective lens 144 has a lens center (first principal point) at the focal point of the other curved surface (the curved surface with the opposite sign) that is paired with one curved surface of a two-leaf hyperboloid that defines the shape of the variable optical element 51 described later. It is arranged to be located. The CCD image sensor 146 generates an image signal based on the light intensity distribution of the subject image formed on the imaging surface. In the present embodiment, a single-plate color image sensor having a Bayer array color filter is used as the CCD image sensor 146.

  Note that the light distribution optical system and the objective optical system in the present embodiment are configured by a single optical lens, but an optical system including a plurality of optical lens groups and optical elements other than lenses such as an optical filter and a deflection element, for example. It may be composed of a system. Depending on the design, necessary illumination can be obtained without providing a light distribution optical system.

  The operation unit 13 is a part that the operator holds to operate the endoscope 10. The operation unit 13 is provided with various operation means such as an operation button 132 and an operation knob 134 for the operator to operate the endoscope system 1 during the operation. Further, a forceps channel 148 for introducing a treatment tool such as forceps penetrates from the forceps insertion opening 148a provided in the operation section 13 to the distal end of the insertion section 14, and the operator inserts the treatment tool into the forceps insertion opening 148a. Then, it is inserted into a forceps channel and sent to an observation site, and a tissue collection and various treatments can be performed using a treatment tool.

  As shown in FIG. 1, a signal line connection plug 18 and a light guide connection plug 19 are provided on the connection surface of the connection portion 11. In addition, a signal line connection socket 28 and a light guide connection socket 29 are provided on the front panel 20 f of the processor 20. By inserting the light guide connection plug 19 into the light guide connection socket 29, the endoscope 10 and the processor 20 are optically connected. Further, by inserting the signal line connection plug 18 into the signal line connection socket 28, various signal lines and power lines of the endoscope 10 are electrically connected to corresponding wirings in the processor 20. Further, the connection portion 11 is provided with well-known engagement means (not shown) (for example, a screw mechanism or a hook mechanism) for detachably mounting the endoscope 10 to the processor 20.

  The connection unit 11 also includes a CCD drive circuit 112 that supplies a drive signal to the CCD image sensor 146, and a signal that performs processing such as gamma correction by converting an analog image signal output from the CCD image sensor 146 into a digital video signal. A processing circuit 114 and a visual field switching control circuit 116 that supplies a driving voltage to the visual field switching adapter 50 are arranged. The CCD drive circuit 112 is connected to the system control circuit 21 of the processor 20 via the signal line connection plug 18, generates a drive signal based on the control signal from the system control circuit 21, and is connected to the CCD via the wire. Transmit to the image sensor 146. The signal processing circuit 114 is connected to the video signal processing circuit 23 of the processor 20 via the signal line connection plug 18, and transmits the generated digital video signal to the video signal processing circuit 23.

  The processor 20 includes a system control circuit 21 that comprehensively controls each part of the processor 20, the endoscope 10, and the visual field switching adapter 50, a light source unit 22 that generates illumination light and supplies it to the light guide 15, and the endoscope 10. A video signal processing circuit 23 that processes a digital video signal from the video signal to generate and output a video signal to the outside, a touch panel display 24 that displays information necessary for operating the endoscope apparatus 1 and accepts a user input operation; A video output interface 25 for outputting various video signals to the external monitor 30 and a user input device interface 26 for connecting user input devices such as a keyboard 262 and a mouse 264 are provided. The light source unit 22 condenses the illumination light emitted from the light source body 222, the automatic diaphragm mechanism 224 that adjusts the amount of illumination light coupled to the light guide 15, and the light source body 222 to the light guide 15 with high efficiency. A condensing lens 226 for coupling is provided. The light source body 222 is a well-known element (not shown) such as a control unit that controls the entire light source unit 22, a high-intensity white lamp (xenon lamp) that emits illumination light, a lamp power supply circuit that supplies driving power to the lamp, and a lamp holder. It is composed of

  Next, the configuration of the visual field switching adapter 50 attached to the distal end of the insertion portion 14 of the endoscope 10 will be described in detail. The endoscope 10 according to the first embodiment of the present invention has a forward angle of the insertion portion 14 (when the downward direction in FIGS. 1 and 2 is the distal direction of the insertion portion 14, the angle formed with the distal direction is approximately Front observation for observing 0 to ± 60 °) and lateral and rear all directions (direction in which the angle formed with the distal end direction of the insertion portion 14 is approximately ± 60 to 150 °) Backward observation is possible, and the visual field switching adapter 50 switches the front visual field and the side / back visual field. Specifically, the visual field switching adapter 50 switches the optical path of the illumination light and the return light from the observation site between the front optical path FP and the side / rear optical path BP.

  FIG. 3 is an enlarged perspective view showing a state in which the visual field switching adapter 50 according to the first embodiment of the present invention is attached to the distal end surface of the insertion portion 14 of the endoscope 10. The field-of-view switching adapter 50 is a column-shaped unit that is substantially formed of a transparent member such as optical glass, and two electrodes 54a and 54b protrude from the mounting surface (the lower surface in FIG. 3). On the other hand, the distal end surface 14e of the insertion portion 14 of the endoscope 10 is imaged by a pair of exit ports 142a through which illumination light emitted from the light distribution lens 142 is emitted, an exit 148b of the forceps channel 148, and a CCD image sensor 146. An observation window 144a into which the observation light to be incident is opened. The exit port 142a and the observation window 144a are closed by a glass plate so that the lens is not soiled by body fluids or the like, and constitutes an optical aperture through which only light passes. In addition, two terminal holes 149a and 149b are formed on the distal end surface 14e of the insertion portion 14 according to the present embodiment with the observation window 144a interposed therebetween. As shown by arrows in FIG. 3, rod-shaped electrodes 54 a and 54 b of the visual field switching adapter 50 are inserted into the terminal holes 149 a and 149 b, respectively, and the distal end of the insertion portion 14 covers the observation window 144 a of the endoscope 10. A visual field switching adapter 50 is attached to the surface. In addition, contacts (not shown) electrically connected to the visual field switching control circuit 116 through wires are provided on the inner periphery of the terminal holes 149a and 149b, and the electrodes 54a and 54b are inserted into the terminal holes 149a and 149b. Thus, the visual field switching adapter 50 is electrically connected to the visual field switching control circuit 116.

  4 and 5 are a longitudinal sectional view and a transverse sectional view showing a schematic structure of the visual field switching adapter 50 according to the first embodiment of the present invention, respectively. The field-of-view switching adapter 50 includes a first transparent member 52, a second transparent member 53, a variable optical element 51 sandwiched between both transparent members, transparent electrodes 52a and 52b, electrodes 54a and 54b, a transparent insulating tube (not shown), and the like. It is composed of The variable optical element 51 is a film-like optical element having a variable reflectance, and has an optical state between a reflective state in which light is reflected with high reflectance and a transmissive state in which light is transmitted with low reflectance. It has a changing nature. Details of the variable optical element 51 will be described later.

  The first transparent member 52 and the second transparent member 53 are a pair of axisymmetric members formed from a transparent optical material, and the symmetry axis that is the optical axis coincides with the optical axis of the objective lens 144 of the endoscope 10. To be arranged. Optical materials for forming the first transparent member 52 and the second transparent member 53 include optical glass such as crown glass, flint glass, and quartz glass, or polycarbonate (PC), polymethyl methacrylate (PMMA), cyclic olefin resin, and the like. The optical resin is used. The outer surface of the first transparent member 52 includes a flat surface that is a mounting surface, a concave curved surface that faces the flat surface, and a cylindrical side surface. The concave curved surface is formed as a two-leaf hyperboloid. Further, the outer surface of the second transparent member 53 is composed of one flat surface and one convex curved surface. The convex curved surface of the second transparent member 53 is formed as a two-leaf hyperboloid having the same shape as the concave curved surface of the first transparent member 52. A film-shaped variable optical element 51 is formed between the concave curved surface of the first transparent member 52 and the convex curved surface of the second transparent member 53.

  Next, the detailed configuration of the variable optical element 51 will be described. The variable optical element 51 of the present embodiment utilizes an optical phenomenon seen in some metal thin films such as magnesium, that is, a phenomenon that reversibly changes from a state showing metal reflection to a transparent state by hydrogenation. is there. In addition, the variable optical element applicable to the embodiment of the present invention is not limited to the one using the change in optical characteristics due to hydrogenation of the metal as described above, and other physical, chemical, or mechanical. A mechanism may be used.

FIG. 6 is a diagram illustrating a schematic configuration of the variable optical element 51 in the embodiment of the present invention. The variable optical element 51 is a film-like optical element composed of a transparent electrode layer 51a, an ion storage layer 51b, a solid electrolyte layer 51c, a proton injection layer 51d, and a reflectivity variable layer 51e. It is integrally formed on the concave curved surface. The transparent electrode layer 51a is a thin film of ITO (Indium-Tin Oxide) which is a transparent conductive material. The transparent electrode layer 51a is formed on the concave curved surface of the first transparent member 52 by a dip coating method or the like. An ion storage layer 51b, which is a tungsten oxide thin film, is formed on the transparent electrode layer 51a. The ion storage layer 51b is formed by a reactive sputtering method using metallic tungsten as a target in a mixed atmosphere of oxygen and argon. A solid electrolyte layer 51c, which is a tantalum oxide thin film, is formed on the ion storage layer 51b. The solid electrolyte layer 51c is formed by an RF sputtering method using tantalum oxide as a target in a mixed atmosphere of oxygen and argon. A proton injection layer that is a platinum thin film is formed on the solid electrolyte layer 51c. Also, a reflectivity variable layer 51e, which is a magnesium / nickel alloy thin film, is formed on the proton injection layer 51d. The proton injection layer 51d and the reflectivity variable layer 51e are formed by a magnetron sputtering method in an argon atmosphere. After forming the reflectivity variable layer 51 e, the variable optical element 51 is exposed to a hydrogen atmosphere, and hydrogen ions (H ⁺ ) are taken into the variable optical element 51. Thereafter, the concave curved surface of the first transparent member 52 on which the variable optical element 51 is formed and the convex curved surface of the second transparent member 53 are bonded together by an adhesive (adhesive layer 51f) such as silicone.

  The magnesium / nickel alloy thin film constituting the reflectivity variable layer 51e has a property of being in a transparent state that transmits visible light when combined with hydrogen and in a reflective state exhibiting a metallic luster when hydrogen is released. When the transparent electrode layer 51a is grounded and a positive voltage is applied to the reflectivity variable layer 51e, hydrogen ions in the reflectivity variable layer 51e pass through the proton injection layer 51d and the solid electrolyte layer 51c and move to the ion storage layer 51b. Accumulated. Thereby, the reflectivity variable layer 51e is dehydrogenated to be in a reflective state. When a negative voltage is applied to the reflectivity variable layer 51e, hydrogen ions accumulated in the ion storage layer 51b move through the solid electrolyte layer 51c and the proton injection layer 51d to the reflectivity variable layer 51e. Thereby, the reflectivity variable layer 51e is hydrogenated and becomes transparent. Thus, by applying a voltage between the transparent electrode layer 51a and the reflectivity variable layer 51e, the transparent state and the reflective state are reversibly switched according to the polarity of the voltage.

  Further, two grooves 52c and 52d for attaching the electrodes 54a and 54b are formed in the lower part of the side surface of the first transparent member 52 (lower side in FIG. 4). Further, transparent electrodes 52 a and 52 b made of an ITO thin film are formed on the side surface of the first transparent member 52. The transparent electrodes 52a and 52b are electrically connected to the transparent electrode layer 51a and the reflectivity variable layer 51e, respectively. The upper portions of the electrodes 54a and 54b are respectively accommodated in the grooves 52c and 52d of the first transparent member 52, and are electrically connected to the transparent electrodes 52a and 52b by solder or conductive paste, respectively. Furthermore, the electrodes 54a and 54b are firmly fixed to the first transparent member 52 with an adhesive. Therefore, the electrode 54a is electrically connected to the transparent electrode layer 51a, and the electrode 54b is electrically connected to the reflectivity variable layer 51e. After completion of the electrical connection in the visual field switching adapter 50, the entire visual field switching adapter 50 except for the protruding portions of the electrodes 54a and 54b is covered with a transparent insulating tube formed of a transparent film such as a silicone resin, and the outside Electrical insulation is ensured. Insulation may be ensured by covering the visual field switching adapter 50 with a member of a cylindrical glass or a hard transparent resin instead of the resin film and filling the gap with a transparent resin or the like.

  Next, the function of the visual field switching adapter 50 will be described in detail. FIG. 7 is a diagram showing optical paths of return light from the observation target in the front observation (a) and the side / rear observation (b) (front observation optical path FP, side / rear observation optical path BP). When the variable optical element 51 is in a transparent state, the front observation light FP is incident from the plane of the second transparent member 53, is transmitted through the variable optical element 51 and the first transparent member 52, and is incident on the objective lens 144. Here, the medium before and after the variable optical element 51, that is, the first transparent member 52 and the second transparent member 53 have the same refractive index, and the film thickness of the variable optical element 51 is extremely thin. The difference in refractive index between 52 and the second transparent member 53 is not large. Therefore, when the variable optical element 51 is in a transparent state, almost no refractive power is generated by the variable optical element 51, and the front observation light is incident on the objective lens through a flat glass with a substantially uniform refractive index. Behave. Accordingly, the field-of-view switching adapter 50 provides the same forward observation image as that of a general forward observation endoscope without enlarging / reducing or distorting the forward observation image formed on the imaging surface of the CCD image sensor 146. . On the other hand, when the variable optical element 51 is in the reflective state, the side / rear observation light BP is incident on the first transparent member 52 from the side surface (cylindrical surface), reflected at the interface with the variable optical element 51, and further After exiting from the plane of the first transparent member 52, it enters the objective lens 144. Here, since the reflecting surface is a convex curved surface, the side / rear observation light that is incident from the side surface of the first transparent member 52 and forms an image on the imaging surface of the CCD image sensor 146 forms the tip direction of the visual field switching adapter 50. The angle ranges over a wide range of approximately ± 60 to 150 °. That is, the visual field switching adapter 50 gives an image of an omnidirectional visual field from the side to the rear. In this way, the visual field switching adapter 50 provides an optical path for performing front observation when the variable optical element 51 is in a transparent state, and provides an optical path for performing side / rear observation when in a reflective state. It is configured as follows.

  Next, in the endoscope apparatus 1 to which the visual field switching adapter 50 is attached, details of the operation when switching between the front observation and the side / backward observation will be described. First, when performing forward observation, the user performs user input for switching to the forward visual field using the operation button 132 or the like. When recognizing this user input, the system control circuit 21 sends a signal instructing switching to the front visual field to the visual field switching control circuit 116. The visual field switching control circuit 116 applies a negative DC voltage to the wiring connected to the visual field switching adapter 50 when receiving a command to switch to the front visual field. Here, the negative DC voltage is a DC voltage such that the reflectivity variable layer 51e of the variable optical element becomes a negative electrode. Specifically, the wiring connected to the reflectivity variable layer 51e (electrode 54b) is connected to the negative electrode. And a DC voltage with the wiring connected to the transparent electrode layer 51a (electrode 54a) as a positive electrode. At this time, hydrogen ions accumulated in the ion storage layer 51b move to the reflectivity variable layer 51e, and the reflectivity variable layer 51e is hydrogenated and changes to a transparent state. An observation image is formed.

  In the case of performing side / rear observation, when the user performs user input for switching to the side / rear view with the operation button 132 or the like, the system control circuit 21 recognizes the user input and moves to the side / rear view. Is sent to the visual field switching control circuit 116. The visual field switching control circuit 116 applies a positive DC voltage to the wiring connected to the visual field switching adapter 50 when receiving a switching command to the lateral / rear visual field. Here, the positive DC voltage is a DC voltage such that the reflectivity variable layer 51e of the variable optical element becomes a positive electrode. Specifically, the wiring connected to the reflectivity variable layer 51e (electrode 54b) is connected to the positive electrode. And a DC voltage with the wiring connected to the transparent electrode layer 51a (electrode 54a) as a negative electrode. At this time, the hydrogen ions bonded to the reflectivity variable layer 51e move toward the transparent electrode layer 51a and are restrained by the ion storage layer 51b. As a result, the reflectivity variable layer 51e is dehydrogenated and changes to a reflective state, and an omnidirectional observation image with lateral and rear visual fields is formed on the imaging surface of the CCD image sensor 146.

  The processor 20 can also display the omnidirectional observation images of the lateral and rear visual fields captured by the CCD image sensor 146 on the monitor 30 as they are. However, this omnidirectional observation image is an image reflected by a convex curved surface of a bilobal hyperboloid, so it has uneven and large distortion in the elevation direction (angle direction from the front to the back) and is suitable for observation. Not a thing. Further, as described above, in the present embodiment, the center (first principal point) of the objective lens 144 is at the focal point of the other curved surface paired with one curved surface of the two-leaf hyperboloid that defines the shape of the variable optical element 51. Is arranged. Because of this configuration, omnidirectional observation is easy to convert into a planar perspective projection image or a 360-degree panoramic image viewed from the mirror focal point of the variable optical element 51 (the focal point of a biplane hyperboloid that defines the shape of the variable optical element 51). An image is acquired. Therefore, the processor 20 according to the embodiment of the present invention automatically converts the omnidirectional observation image of the lateral / rear visual field into a plane perspective projection image or a 360-degree panoramic image based on the user setting, and outputs it to the monitor 30. It has a function to display. In this embodiment, image conversion from an omnidirectional observation image to a plane perspective projection image is automatically executed during side / rear visual field observation, and a video for displaying the converted plane perspective projection image on the monitor 30 is displayed. It is set to output a signal.

  In the first embodiment described above, the two rod-shaped electrodes 54a and 54b that protrude vertically from the mounting surface of the visual field switching adapter 50 extend vertically from the distal end surface 14e of the insertion portion 14 of the endoscope 10. The visual field switching adapter 50 is configured to be mounted on the distal end surface 14e of the insertion portion 14 by being inserted into the two linear terminal holes 149a and 149b. However, the shape of the electrode of the visual field switching adapter and the terminal hole of the endoscope is not limited to a linear shape, and can take various shapes. FIG. 8 shows a first modification of the configuration in which the visual field switching adapter is attached to the insertion portion of the endoscope. Moreover, the A arrow view in FIG. 8 is shown in FIG. 8 (A), and the B arrow view is shown in FIG. 8 (B), respectively. The electrodes 54c and 54d in the first modification have their tip portions bent 90 ° radially outward of the visual field switching adapter 50a to form an L-shaped hook 54h. Further, arc-shaped terminal holes 149c and 149d concentric with the observation window 144a are formed in the distal end surface 14e of the endoscope insertion portion 14a. The terminal holes 149c and 149d are formed with engaging claws 149e that engage with the hooks 54h except for the attaching / detaching portion indicated by the symbol A, and the cross-sectional shape is an L shape corresponding to the electrodes 54c and 54d. (FIG. 8B). For this reason, since the L-shaped electrodes 54c and 54d are engaged with the terminal holes 149c and 149d except for the detachable portion A, the electrodes 54c and 54d can slide along the arcs of the terminal holes 149c and 149d. However, it cannot be pulled out from the terminal holes 149c and 149d. Further, in the attaching / detaching portion A, the engaging claws 149e are not formed, and the cross-sections of the terminal holes 149c and 149d are formed in a rectangle having a width wider than the width of the L-shaped electrodes 54c and 54d (see FIG. 8 (A)). Therefore, in the detachable portion A, the electrodes 54c and 54d can be slid along the arcs of the terminal holes 149c and 149d, or can be pulled out from the terminal holes 149c and 149d. That is, when the visual field switching adapter 50a is attached to the distal end surface 14e of the insertion portion 14a of the endoscope 10a, the L-shaped electrodes 54c and 54d are inserted into the terminal holes 149c and 149d from the attachment / detachment portion A, respectively. 50a is twisted in the direction of the arrow (counterclockwise) in FIG. 8, and the electrodes 54c and 54d are slid along the arc-shaped terminal holes 149c and 149d. When removing the visual field switching adapter 50a from the insertion portion 14a of the endoscope 10a, the visual field switching adapter 50a is twisted in the reverse direction (clockwise) so that the electrodes 54c and 54d are disposed along the arc-shaped terminal holes 149c and 149d. The terminal holes 149c and 149d are pulled out from the attaching / detaching part A by sliding. As in the first embodiment, contacts (not shown) connected to the visual field switching control circuit 116 are provided on the inner periphery of the terminal holes 149c and 149d, and the electrodes 54c and 54d are connected to the terminal holes 149c and 149d, respectively. By engaging, the visual field switching adapter 50a is electrically connected to the visual field switching control circuit 116. According to the configuration of the first modification, a large force in the direction of pulling out the electrodes 54c and 54d from the visual field switching adapter 50a is not applied to the electrodes 54c and 54d when the visual field switching adapter 50 is attached or detached. Therefore, the electrodes 54c and 54d are difficult to come off due to the attachment / detachment of the visual field switching adapter 50. Further, since the hook 54h and the engaging claw 149e are engaged, the electrodes 54c and 54d do not fall out of the terminal holes 149c and 149d during use, and the visual field switching adapter 50a does not fall off the endoscope 10.

  The visual field switching adapter 50 according to the first embodiment described above covers only the observation window 144 a, and the illumination light exit port 142 a and the forceps channel outlet 148 are not blocked by the visual field switching adapter 50. However, the present invention is not limited to this configuration. For example, a configuration in which the visual field switching adapter covers all openings except for the outlet of the forceps channel and a configuration in which the visual field switching adapter covers the entire distal end surface of the endoscope are also included in the scope of the present invention. FIG. 9 is a diagram illustrating a second modification in which the visual field switching adapter covers the entire front end surface 14e of the endoscope. The visual field switching adapter 50b of the second modification is formed so that the diameter is the same as or slightly smaller than the distal end portion of the insertion portion 14b of the endoscope 10a. The terminal holes 149a 'and 149b' are formed in the vicinity of both ends of the diameter of the insertion portion 14b passing through the center of the observation window 144a corresponding to the attachment positions of the electrodes 54a and 54b of the visual field switching adapter 50b. Furthermore, the variable optical element 51 'is formed so as to cover substantially the entire front end surface 14e of the endoscope in order to ensure a wide effective field of view in the direction distal to the observation window 144a. Specifically, the variable optical element 51 ′ is formed in a substantially conical shape having the entire front end surface 14e (upper surface in FIG. 9) of the visual field switching adapter 50b as a bottom surface and having a vertex right above the center of the observation window 144a. ing. With this configuration, it is possible to observe an image behind the azimuth distant from the observation window 144a. In addition, during side / rear observation, the illumination light emitted from the exit port 142a is also reflected by the variable optical element 51 ', so that the side and rear can be illuminated sufficiently brightly.

  The visual field switching adapter 50 according to the first embodiment described above is configured such that the electrodes 54a and 54b are inserted into the terminal holes 149a and 149b formed in the distal end surface 14e of the endoscope 10 for use. However, the attachment of the visual field switching adapter to the endoscope distal end and the configuration of the wiring to the visual field switching adapter of the present invention are not limited to the above embodiment. The second embodiment of the present invention to be described next is an example of a configuration in which the visual field switching adapter is attached to the distal end of the insertion portion of a normal endoscope in which no terminal hole is formed using an adapter mounting tool.

  FIG. 10 is a longitudinal sectional view showing an outline of a mounting structure of the visual field switching adapter 50c according to the second embodiment of the present invention. As shown in FIG. 10, the visual field switching adapter 50 c is attached to the distal end of the insertion portion 14 c of the endoscope 10 c via the adapter attachment tool 56. The field-of-view switching adapter 50c according to the second embodiment is the second modification of the first embodiment, except that the electrodes 54a and 54b and the grooves 52c and 52d for attaching them are not provided in the first embodiment. There is no substantial difference in configuration from the visual field switching adapter 50b according to the example. Note that the transparent electrodes 52a and 52b of the visual field switching adapter 50c according to the second embodiment extend to the vicinity of the bottom surface. Further, the transparent electrodes 52a and 52b are not covered with insulation in the vicinity of the bottom surface, and wires 57a and 57b are soldered to portions where the transparent electrodes 52a and 52b are exposed, respectively.

  FIG. 11 is a schematic top view (viewed from above in FIG. 10) of the adapter mounting tool 56 according to the second embodiment of the present invention. The adapter mounting tool 56 is a member formed from a transparent resin such as PC or PMMA or optical glass. A concave portion 56a into which the bottom of the visual field switching adapter 50c is inserted is formed on the upper surface of the adapter mounting tool 56, and a concave portion 56b into which the distal end of the insertion portion 14c of the endoscope 10c is inserted is formed on the lower surface. A groove 56c for accommodating the wires 57a and / or 57b is formed on the periphery of the bottom of the recess 56a. Further, the adapter mounting tool 56 has a through hole 56d formed in a portion facing the outlet 148b of the forceps channel when the distal end of the insertion portion 14c of the endoscope 10c is inserted into the recess 56b. The space formed by the groove 56c after mounting is in communication with the through hole 56d.

  Locations where the transparent electrodes 52a and 52b of the visual field switching adapter 50c described above are exposed (including locations where the wires 57a and 57b are soldered) are accommodated in the grooves 56c. The wires 57a and 57b are passed through the through hole 56d through a passage formed by being surrounded by the groove 56c and the visual field switching adapter 50c.

  FIG. 12 is a block diagram showing an outline of the overall configuration of an endoscope apparatus 1c according to the second embodiment of the present invention. The wires 57a and 57b passed through the through-hole 56 are then passed through a forceps channel 148 that is not used, drawn out from the forceps insertion port 148a to the outside of the endoscope 10c, and connected to the output terminal of the visual field switching control terminal 116c. Has been. The visual field switching control terminal 116c is a unit provided outside the endoscope 10c and has the same function as the visual field switching control circuit 116 in the first embodiment. That is, the visual field switching control terminal 116c supplies a driving voltage to the visual field switching adapter 50 based on a command from the system control circuit 21 of the processor 20c. The visual field switching control terminal 116c is also connected to the processor 20c through a control line 57c, and a signal from the system control circuit 21 is sent to the visual field switching control terminal 116 through the control line 57c.

  When a user input for switching to the front visual field is performed by operating the operation button 132 of the endoscope 10c or the touch panel display 24 of the processor 20c, the system control circuit 21 recognizes this user input and switches to the front visual field. A command signal is transmitted to the visual field switching control terminal 116c. The visual field switching control terminal 116c applies a negative DC voltage to the wires 57a and 57b connected to the visual field switching adapter 50c when receiving the instruction to switch to the front visual field. Here, the negative DC voltage is a DC voltage that causes the reflectivity variable layer 51e of the variable optical element to be a negative electrode. Specifically, the wire 57a connected to the reflectivity variable layer 51e is used as a negative electrode, and transparent. This is a DC voltage with the wire 57b connected to the electrode layer 51a as the positive electrode. At this time, the reflectivity variable layer 51e is hydrogenated to be in a transparent state, and an observation image of the front visual field is formed on the imaging surface of the CCD image sensor 146. Next, when a user input for switching to the lateral / rear visual field is performed, the visual field switching control terminal 116c applies a positive DC voltage to the wires 57a and 57b. Here, the positive DC voltage is a DC voltage such that the first electrode layer 51a serves as an anode. Specifically, the wire 57a connected to the reflectivity variable layer 51e is used as a positive electrode, and the transparent electrode layer 51a is applied to the transparent electrode layer 51a. This is a DC voltage with the connected wire 57b as the negative electrode. At this time, the reflectivity variable layer 51e is dehydrogenated to be in a reflective state, and an observation image of a lateral / rear visual field is formed on the imaging surface of the CCD image sensor 146.

  The visual field switching control terminal 116c is provided with a manual visual field switching switch 116s for switching between the front visual field and the side / back visual field. The user can operate the visual field switching adapter 50c without operating the processor 20c by operating the manual visual field switching switch 116s. When operating the visual field switching adapter 50c using only the manual visual field switching switch 116s, the visual field switching control terminal 116c may not be connected to the processor 20c by the control line 57c. For this reason, a visual field switching function can be added to an endoscope apparatus that uses an existing processor that does not support the control of the visual field switching control terminal 116c. Further, by updating the software of the existing processor, it is possible to add a function for converting the side / rear observation image to the processor.

  As described above, the field-of-view switching adapter 50c according to the second embodiment of the present invention is mounted on a conventional endoscope in which a terminal hole for mounting the field-of-view switching adapter is not provided by using the adapter mounting tool 56. Thus, a visual field switching function can be added. Further, in order to add a visual field switching function to the endoscope, it is necessary to add a wire (control line) for transmitting a signal for controlling the visual field switching adapter. In the second embodiment, a wire is connected to the forceps channel. By adopting the configuration to pass through, it is possible to increase the number of wires without modifying the conventional endoscope. The adapter mounting tool 56 is preferably formed of a transparent resin, but may be formed of an opaque material, or may be formed of an inorganic material such as glass or a metal material.

  The field-of-view switching function is particularly useful in endoscopy for observing a wide range, but a treatment tool is often not used during examination (especially periodic medical examination), and the forceps channel is vacant. That is, the configuration of the second embodiment of the present invention makes effective use of the forceps channel by paying attention to the actual usage of the endoscope that the frequency of use of the forceps channel is low during an endoscopic examination in which the visual field switching function is frequently used. This makes it possible to add a visual field switching function to an existing endoscope without modification.

  Moreover, although the said embodiment is an example with which all were attached to the electronic scope, the endoscope to which this invention is applied is not limited to an electronic scope, For example, a fiberscope may be sufficient.

1 Endoscopic device 10 Endoscope (electronic scope)
DESCRIPTION OF SYMBOLS 11 Connection part 112 CCD drive circuit 114 Signal processing circuit 116 Field-of-view switching control circuit 12 Universal cable part 13 Operation part 14 Insertion part 142 Light distribution lens 144 Objective lens 144a Observation window 146 CCD image sensor 148 Forceps channel 149a, 149b Terminal hole 15 Light Guide 20 Processor 21 System control circuit 22 Light source unit 23 Video signal processing circuit 30 External monitor 50 Field-of-view switching adapter 51 Variable optical element 52 First transparent member 53 Second transparent members 54a and 54b Electrodes

Claims (14)

An endoscope visual field switching adapter that is attached to the tip of an endoscope and enables observation of a plurality of visual fields,
A first optical path that forms an image of the first field of view and a second optical path that forms an image of the second field of view by changing the state of the optical element. An endoscope field-of-view switching adapter characterized by switching between and. When the optical element is in a transmissive state, an image of a first field of view is formed by the first optical path that passes through the optical element,
2. The endoscope visual field switching adapter according to claim 1, wherein when the optical element is in a reflective state, an image of the second visual field is formed by the second optical path reflected by the optical element.   The endoscope visual field switching adapter according to claim 1, wherein the optical element has a variable reflectance, and switches between a transmission state and a reflection state according to a change in the reflectance.   The endoscope field-of-view switching adapter according to any one of claims 1 to 3, wherein the first field of view includes a front field of view, and the second field of view includes a rear field of view.   5. The endoscope visual field switching adapter according to claim 1, wherein the first visual field includes a front visual field, and the second visual field includes a side visual field. 6.   6. The endoscope field-of-view switching adapter according to claim 1, wherein the optical element has a reflecting surface in a reflecting state formed in a shape suitable for omnidirectional observation.   7. The endoscope visual field switching adapter according to claim 6, wherein the shape suitable for omnidirectional observation is a bilobal hyperboloid.   The endoscope visual field switching adapter according to any one of claims 1 to 7, wherein the optical element includes a reflectivity variable film. An adapter mounting tool for mounting the endoscope visual field switching adapter according to any one of claims 1 to 8 to a distal end of an endoscope,
A first recess into which the tip of the endoscope can be inserted;
A second recess into which an endoscope adapter can be inserted;
A through hole provided in a portion facing the outlet of the forceps channel of the endoscope;
An adapter mounting tool, characterized in that a groove is formed on the periphery of the bottom of the first recess and communicates with the through hole.   A visual field switching endoscope comprising the endoscope visual field switching adapter according to any one of claims 1 to 8. A controller for controlling the endoscope visual field switching adapter;
The endoscope visual field switching adapter has a pair of electrodes,
A pair of terminal holes that engage with the pair of electrodes are formed at the distal end of the endoscope,
The field-of-view switching endoscope according to claim 10, wherein the pair of terminal holes are connected to the control unit and supply a control voltage to the pair of electrodes.   13. The visual field switching inside according to claim 10, wherein the endoscope is an electronic endoscope, and the images of the first and second visual fields are formed on an imaging surface of an imaging element. Endoscope.   The endoscope according to claim 10 or 12, wherein the endoscope is a fiberscope having an optical fiber bundle, and the images of the first and second visual fields are formed on an end face of a tip end of the optical fiber bundle. The endoscope described.   11. An endoscopic processor to which the field-of-view switching endoscope according to claim 10 can be directly or indirectly cited, wherein an omnidirectional observation image captured by the endoscope is planarly viewed. An endoscope processor characterized by converting into a projected image or a panoramic image.

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