JP2016131580A - Observation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an observation device with an insertion part in which the length of the tip of the insertion part in an axial direction can be reduced and the diameter of the insertion part can be made thin.SOLUTION: An endoscope device includes a slender flexible insertion part, an objective lens 24 provided to the tip 11 of the insertion part, an image pickup device 27 provided to the tip 11 of the insertion part for receiving light that passes through the objective lens 24, and a movable optical filter 33 provided between the objective lens 24 and the image pickup device 27 that includes a first area having first optical characteristics and a second area having second optical characteristics different from the first optical characteristics with high transmissivity, and causes the light that passes through the objective lens 24 to pass through the first area or the second area selectively.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an observation apparatus, and more particularly to an observation apparatus having an elongated insertion portion.

  Conventionally, an observation apparatus for observing a subject such as an industrial endoscope has been widely used. For example, an industrial endoscope is used for observing various inspection objects, and can observe various parts in the inspection object. An image observed by the observation device is obtained by an image sensor, and the observation device can display an image having optimum brightness by exposure control.

The observation apparatus is also used for observing a part being processed in the inspection object. For example, the observation device may be used to check the welding state under arc discharge.
When a high luminance region is generated by arc generation during welding, smearing or blooming occurs in the image. When smear or the like occurs, if the exposure is adjusted to an area with high luminance, there is a problem that the peripheral area of the area becomes dark and the welding state cannot be confirmed.

  Therefore, Japanese Patent Application Laid-Open No. 2008-260055 utilizes a partial dimming by a telecentric optical system and a plurality of photochromic filters as an optical system for filtering arc discharge light in order to confirm a welding state under arc discharge. A welding observation apparatus is disclosed. A photochromic filter is a filter that becomes darker in color when it receives ultraviolet rays.

JP 2008-260055 A

  However, in the case of the proposed apparatus, since a plurality of photochromic filters are used in a region where the light beam height is high in the optical path, the diameter of the distal end portion of the insertion portion becomes large, and the objective optical system and the photochromic filter There is a problem that the length in the optical axis direction of the front end portion of the group becomes long.

Even if the observation device is shaped like an endoscope, if the outer diameter of the distal end portion of the insertion portion that is substantially cylindrical is thick and the length of the hard portion in the axial direction of the distal end portion is long, the insertion portion In some cases, it is not possible to insert the distal end portion of the inner space into a narrow space in the inspection object.
A configuration in which a fiber bundle is used in the insertion portion and an image is taken with a camera provided at the proximal end portion of the insertion portion is also conceivable. However, in such a configuration, an endoscope image with sufficient resolution cannot be obtained.

  Therefore, an object of the present invention is to provide an observation apparatus having an insertion portion, in which the length of the distal end portion of the insertion portion in the axial direction can be shortened and the diameter can be reduced.

  According to one aspect of the present invention, the flexible and elongated insertion portion, the objective optical system provided at the distal end portion of the insertion portion, the objective optical system provided at the distal end portion of the insertion portion, and the objective An image sensor that receives light transmitted through an optical system, a first area that is provided between the objective optical system and the image sensor, and that has a first optical characteristic, is different from the first optical characteristic. And a movable optical element that selectively transmits the light transmitted through the objective optical system to the first region or the second region. An apparatus can be provided.

  ADVANTAGE OF THE INVENTION According to this invention, it is an observation apparatus which has an insertion part, Comprising: The observation apparatus which can shorten the length of the axial direction of the front-end | tip part of an insertion part, and can make a diameter thin can be provided.

1 is an overall configuration diagram of an endoscope apparatus 1 according to an embodiment of the present invention. It is sectional drawing which shows the structure of the front-end | tip part 11 of the insertion part 2 concerning embodiment of this invention. It is sectional drawing of the front-end | tip part 11 along the III-III line | wire of FIG. It is a front view of the movable optical filter 33 according to the embodiment of the present invention viewed from the axial direction of the insertion portion 2. It is a side view of the movable optical filter 33 seen from the direction orthogonal to the axis | shaft of the insertion part 2 concerning embodiment of this invention. It is sectional drawing of the front-end | tip part 11 seen from the base end side along the VI-VI line of FIG.2 and FIG.3. It is sectional drawing of the front-end | tip part 11 seen from the front end side along the VII-VII line of FIG.2 and FIG.3. It is sectional drawing of the front-end | tip part 11 seen from the front end side along the VIII-VIII line of FIG.2 and FIG.3. It is sectional drawing of the front-end | tip part 11 seen from the front end side along the VI-VI line of FIG.2 and FIG.3 which shows the modification of the movable optical filter concerning embodiment of this invention. It is sectional drawing of the front-end | tip part 11 seen from the front end side along the VI-VI line of FIG.2 and FIG.3 which shows the modification of the movable optical filter concerning embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
In each drawing used for the following description, the scale is different for each component in order to make each component large enough to be recognized on the drawing. It is not limited only to the quantity of the component described in the drawing, the shape of the component, the ratio of the size of the component, and the relative positional relationship of each component.
(Constitution)
FIG. 1 is an overall configuration diagram of an endoscope apparatus 1 according to the present embodiment. An endoscope apparatus 1 as an observation apparatus includes an elongated insertion portion 2, a main body device 3, a cooling device 4, a compressor 5, a monitor 6, and a power supply device 7.

Here, the endoscope apparatus 1 is used when an inspector confirms the welding state of a welded portion with an image when the workpiece 8 is welded by arc welding.
The elongated insertion portion 2 having flexibility has a base end of the insertion portion 2 connected to the main body device 3 and has an observation window 11a (see FIG. 2) at the distal end portion 11. An imaging element 27 (see FIG. 2) is provided behind the observation window 11a in the distal end portion 11.

  Here, the distal end portion 11 of the insertion portion 2 is not provided with a bending portion, but the insertion portion 2 may have a bending portion. In this case, the user can operate the operation portion such as a joystick. Thus, the bending portion can be bent in the vertical and horizontal directions so that the observation direction of the distal end portion 11 can be directed to a desired direction.

  The main body device 3 is a device having a control unit that controls the overall control and operation of the endoscope device 1. The main unit 3 has a central processing unit (CPU), ROM, RAM, and the like inside, and reads a processing program stored in advance from the ROM and executes it in accordance with an operation instruction to an operation panel (not shown). Control of each device connected to the apparatus 3 is performed.

  In the main unit 3, an image generation circuit that generates an image signal based on an output signal from the image sensor and a signal processing circuit that performs various controls based on the generated image signal are provided. As will be described later, the signal processing circuit in the main body device 3 monitors the luminance value included in the image signal generated from the signal output from the image sensor, and based on the luminance value, for example, an arc in the image region. A movement control unit is included that controls the output of the compressed air from the compressor 5 to control the movement of the movable optical element, which will be described later, depending on whether or not there is such a pixel area having a predetermined luminance value or more. The main unit 3 also includes a cooling mechanism control unit that controls a cooling mechanism for cooling the distal end portion 11 described later.

  The cooling device 4 is a device that cools the distal end portion 11 of the insertion portion 2 by flowing a cooling fluid under the control of the main body device 3. The cooling fluid may be either a liquid or a gas, but here, water having higher cooling efficiency is used as compared with air that is a gas.

  The cooling device 4 and the main body device 3 are connected by two tubes 4a and 4b through which fluid circulates. One ends of the tubes 4 a and 4 b are connected to the cooling water supply terminal 3 a and the cooling water return terminal 3 b of the main body device 3, respectively. The fluid cooled by the cooling device 4 is discharged to the main body device 3 through the tube 4a.

  The fluid discharged from the cooling device 4 is supplied into the distal end portion 11 of the insertion portion 2 through the main body device 3. As will be described later, the fluid warmed at the distal end portion 11 returns from the main body device 3 to the cooling device 4 through the tube 4b, is cooled, and is again discharged to the main body device 3 through the tube 4a.

  The compressor 5 is an output air source for supplying compressed air to the insertion unit 2 under the control of the main body device 3. The compressor 5 and the main unit 3 are connected by a tube 5a. One end of the tube 5 a is connected to the compressed air input terminal 3 c of the main body device 3. Compressed air from the compressor 5 is discharged to the main body device 3 through the tube 5 a, and the compressed air is controlled by the electromagnetic valve in the main body device 3 under the control of the main body device 3, so that the two pipe lines of the insertion portion 2 (To be described later) can be supplied.

  The monitor 6 is a display device that displays an image generated by an image generation circuit in the main body device 3. The monitor 6 and the main unit 3 are connected by a cable 6a including a plurality of signal lines. One end of the cable 6 a is connected to the video signal output terminal 3 d of the main device 3.

  The power supply device 7 is a power supply for supplying power to the entire endoscope apparatus 1 such as an AC adapter, and supplies power to the main body device 3. The power supply device 7 and the main unit 3 are connected by a power supply cable 7a. One end of the cable 7 a is connected to the power input terminal 3 e of the main body device 3.

The inspector confirms the state of the bead 8a of the member 8 on the monitor 6 of the endoscope apparatus 1 while welding the member 8 to be welded with the welding electrode 12 of the welding apparatus.
Next, the configuration of the distal end portion 11 of the insertion portion 2 of the endoscope apparatus 1 will be described.
FIG. 2 is a cross-sectional view showing the configuration of the distal end portion 11 of the insertion portion 2. FIG. 3 is a cross-sectional view of the distal end portion 11 taken along line III-III in FIG. FIG. 3 shows a cross-sectional view of the distal end portion 11 along the axial direction of the distal end portion 11.

  The tip portion 11 has a cylindrical shape and has an observation window 11a. A cover glass 21 is provided on the observation window 11a, and the cover glass 21 is fixed to the inside of a metal fixing frame 22 with an adhesive.

The distal end portion of the metal distal end frame 23 is screwed and fixed inside the proximal end opening of the fixed frame 22. A first objective lens 24 that is a cemented lens is fixed in the distal end frame 23 with an adhesive. The objective lens 24 is an objective optical system provided at the distal end portion 11 and is an achromatic lens in which a biconvex lens and a concave flat lens are cemented.
The objective lens 24 has a positive refractive power as a whole. Therefore, the light transmitted through the objective lens 24 is condensed and the light flux is reduced.

  The proximal end portion of the distal end frame 23 is fixed by an adhesive in the distal end portion of the recessed portion on the distal end side of the metal housing 25. An inward flange portion 23a is formed at the proximal end portion of the distal end frame 23, and light incident from the observation window 11a is emitted to the proximal end side of the distal end portion 11 through the opening of the inward flange portion 23a.

The distal end portion of the image pickup unit 26 is fitted into the recess on the proximal end side of the housing 25 and is fixed by an adhesive or the like.
The imaging unit 26 is a camera unit including a second objective optical system and an imaging element 27 such as a CCD. The imaging unit 26 has a cylindrical member 28, and a frame 29 is fixed in the cylindrical member 28. An objective lens 30 as a second objective optical system is fixed inside the front end of the frame 29 with an adhesive. The objective lens 30 is an achromatic lens in which a meniscus concave lens and a biconvex lens are cemented.

  A cover glass 31 is disposed on the base end side of the objective lens 30 and is fixed to the inner side of the frame body 29 with an adhesive. On the base end side of the cover glass 31, an image sensor 27 is disposed and fixed to the frame body 29 with an adhesive. An optical member 32 such as an infrared cut filter is disposed on the imaging surface of the imaging element 27. As described above, the image sensor 27 is provided at the distal end portion 11 of the insertion portion 2 and receives light transmitted through the objective optical system.

A filter storage portion 25a is formed inside the recess on the distal end side of the housing 25, and the movable optical filter 33 is slidably stored in the filter storage portion 25a. In FIG. 2, the movable optical filter 33 is shown in a perspective view, not a cross section, so that the shape of the movable optical filter 33 can be seen.
That is, the movable optical filter 33 is movably provided in the filter storage portion 25a in a state where the proximal end portion of the distal end frame 23 is fixed to the distal end portion of the housing 25.

  4 and 5 are diagrams showing the configuration of the movable optical filter 33. FIG. FIG. 4 is a front view of the movable optical filter 33 as viewed from the axial direction of the insertion portion 2. FIG. 5 is a side view of the movable optical filter 33 viewed from a direction orthogonal to the axis of the insertion portion 2.

  The movable optical filter 33 is an optical element having two optical members 33A and 33B. The optical member 33A is an ND filter member, and the optical member 33B is a colorless and transparent optical glass member. The refractive indexes of the two optical members 33A and 33B are substantially the same. As the optical member 33A, a filter member made of a material that reduces the amount of arc light by a predetermined amount so that smear or the like does not occur even if the image obtained by the image sensor 27 contains arc light is selected.

  As shown in FIG. 4, the two optical members 33A and 33B have a structure in which a part of a cylindrical optical member is cut along the axial direction of the cylinder and the cut surfaces are bonded together with an adhesive. doing. In other words, each of the optical members 33A and 33B has a D-cut shape with a D-shaped cross section, and the movable optical filter 33 is configured by bonding together the D-cut plane portions.

  The two optical members 33A and 33B are formed so that the light from the observation window 11a passes through the parallel plane. As shown in FIG. 5, the incident side surface 33a1 and the exit side surface 33b1 of the optical member 33A are parallel, and the entrance side surface 33c1 and the exit side surface 33d1 of the optical member 33B are parallel. That is, the region where the light of the two optical members 33A and 33B is transmitted is a parallel plane having no optical system power.

  Two reinforcing members 33C made of metal are fixed to both side surfaces of the two bonded optical members 33A and 33B with an adhesive. The two reinforcing members 33C cover the bonded portion of the two optical members 33A and 33B, and when the movable optical filter 33 moves in the filter housing portion 25a, the two reinforcing members 33C are moved to the filter housing portion 25a. This is a member for preventing the two optical members 33A and 33B from directly touching the inner wall of the filter housing portion 25a by contacting the inner wall.

  As described above, the distal end portion 11 has a storage space for storing the movable optical filter 33 that is an optical element. The movable optical filter 33 slides along the inner wall of the housing 25 of the distal end portion 11 forming the filter storage portion 25a, and can reciprocate within the filter storage portion 25a.

  Further, since the objective lens 24 has a positive refractive power, the movable optical filter 33 is used in a region where the light beam height is low in the optical path from the subject. The diameter of the distal end portion 11 can be further reduced.

Returning to FIGS. 2 and 3, a housing 34, which is a cylindrical member, is externally attached to the base end portion of the housing 25 and fixed with an adhesive.
On the proximal end side of the housing 34, the distal end portion of the housing 35 is inserted and fixed with an adhesive. The insertion portion 2 is covered with an exterior member 36 from the proximal end side of the housing 34 to the proximal end portion of the insertion portion 2.
A cable (not shown) including a signal line or the like extending from the imaging unit 26 extends from the base end portion of the cover member 37 provided at the base end portion of the imaging unit 26 into the exterior member 36, and the main body device 3. Connected to an image generation circuit (not shown). The output of the image generation circuit is connected to the input of the monitor 6.

  In the distal end portion 11, the distal ends of two air conduits 41 and 42 to which the compressed air from the compressor 5 is sent, and two water conduits 43 for circulating water from the cooling device 4. , 44 are disposed.

  FIG. 6 is a cross-sectional view of the distal end portion 11 viewed from the proximal end side along the line VI-VI in FIGS. 2 and 3. FIG. 7 is a cross-sectional view of the distal end portion 11 viewed from the distal end side along the line VII-VII in FIGS. 2 and 3. FIG. 8 is a cross-sectional view of the distal end portion 11 viewed from the distal end side along the line VIII-VIII in FIGS. 2 and 3.

  The proximal end side of the housing 25 is surrounded by the cylindrical member 28 and the housings 34 and 35, and the imaging unit 26 is disposed in the cylindrical member 28. A cylindrical space S formed by being surrounded by the housings 34 and 35 and the cylindrical member 28 on the base end side of the housing 25 constitutes a cooling space for cooling the imaging unit 26.

  Between the tubular member 28 and the housing 34, two air pipes 41 and 42 through which air for moving the movable optical filter 33 flows are inserted and disposed. The proximal ends of the two air pipes 41 and 42 are connected to an electromagnetic valve (not shown) in the main unit 3.

  The two air pipes 41 and 42 are pipes through which the compressed air from the tube 5a of the compressor 5 is sent. In response to a user operation instruction, the main body device 3 discharges the compressed air from the compressor 5 to one of the air pipes 41 and 42, and the electromagnetic valve is set so that the other pipe is open. Be controlled.

  The front ends of the two air pipes 41 and 42 are fixed to the housing 25 through the housing 35. As shown in FIGS. 6 and 7, the distal ends of the two air ducts 41 and 42 are opened at openings 41a and 42a formed on the inner wall of the filter storage portion 25a, respectively. As shown in FIG. 7, the openings 41 a and 42 a are formed at axially symmetric positions of the distal end portion 11 of the insertion portion 2.

  As shown in FIG. 7, two openings 41 a and 42 a through which gas is ejected are provided in the distal end portion 11, and are provided outside the optical path where the light beam that has passed through the observation window 11 a is narrowed by the objective lens 24. It has been.

  Further, as shown in FIGS. 6 and 7, the cross section of the filter storage portion 25a in the direction orthogonal to the axis of the insertion portion 2 has a substantially rectangular shape extending in the predetermined direction L1. The filter housing portion 25 a is formed by the proximal end side surface of the inward flange portion 23 a of the distal end frame 23 and the inner wall surface of the distal end side recess of the housing 25.

  The movable optical filter 33 has a shape capable of reciprocating along a predetermined direction L1 in the filter storage portion 25a. The predetermined direction L1 is a direction orthogonal to the optical axis O of the objective lens 24 that is an objective optical system. Further, in this aspect, the optical axis O of the objective lens 24 is disposed so as to substantially coincide with the axis of the tip portion 11, that is, the central axis of the tip portion 11 having a cylindrical shape.

  The width including the two reinforcing members 33C of the movable optical filter 33 is based on the distance between the two opposing inner wall surfaces 25a1 and 25a2 among the inner walls of the concave portion on the front end side of the housing 25 in the direction orthogonal to the predetermined direction L1. Is also small.

  Further, as indicated by the solid line in FIGS. 6 and 7, the movable optical filter 33 is moved in the first direction of the predetermined direction L1 (downward in FIG. 6) and is in contact with the inner wall surface 25a3 of the housing 25. The movable optical filter 33 is configured such that light that enters from the observation window 11a and exits from the opening of the inward flange portion 23a passes through the optical member 33A that is an ND filter and is received by the image sensor 27. Yes.

  6 and 7, the movable optical filter 33 moves in the second direction of the predetermined direction L1 (upward in FIG. 6) and comes into contact with the inner wall surface 25a4 of the housing 25. In the state, the movable optical filter is configured so that the light incident from the observation window 11a and emitted from the opening of the inward flange portion 23a passes through the optical member 33B, which is a colorless and transparent glass member, and is received by the image sensor 27. 33 is configured.

  The optical member 33A has a region having optical characteristics for performing a predetermined amount of light reduction, and the optical member 33B has a region having optical characteristics for not performing light reduction, unlike the optical characteristics of the optical member 33A. The movable optical filter 33 is moved by the gas ejected from the opening 41a or the opening 42a so that the light from the observation window 11a passes through the region of the optical member 33A or the region of the optical member 33B.

Therefore, the movable optical filter 33 is provided between the objective lens 24 and the image sensor 27 and is different from the first optical characteristic and the first region having the first optical characteristic for performing a predetermined amount of light reduction. And a second region having a second optical characteristic that does not reduce light, and a movable optical element that selectively transmits light transmitted through the objective lens 24 to the first region or the second region.
That is, in this embodiment, the transmittance of the optical member 33B is higher than the transmittance of the optical member 33A, and the optical characteristic that can be selectively set is the transmittance.

  As described above, when the movable optical filter 33 slides on the two inner wall surfaces 25a1 and 25a2 along the predetermined direction L1, the two reinforcing members 33C move the two optical members 33A and 33B. It is a member for preventing direct contact.

  When the compressed air is discharged from the opening 41a of the air duct 41, the opening 42a is open on the proximal end side as described above, so that the movable optical filter 33 is moved along the predetermined direction L1 by the force of air. And move to the position indicated by the solid line in FIGS. Further, when compressed air is discharged from the opening 42a of the air conduit 42, the opening 41a is open on the proximal end side, so that the movable optical filter 33 is moved along the predetermined direction L1 by the force of air. It moves to a position indicated by a two-dot chain line in FIGS.

  Further, as shown in FIGS. 3 and 8, the space S between the tubular member 28 and the housing 34 is a flow path for cooling the distal end portion 11, and a water conduit for flowing water. An opening 43 a at the tip of 43 and an opening 44 a at the tip of the water conduit 44 are disposed.

  The distal ends of the two water conduits 43 and 44 pass through the housing 35 and are fixed to the housing 35 so that the openings 43a and 44a at the respective distal ends are disposed in the space S. The opening 43 a is located in the vicinity of the housing 25, and the opening 44 a is located at the same position as the tip side surface of the housing 35.

The water conduit 43 is connected to the tube 4a in the main body device 3, and water sent from the cooling device 4 is discharged from the opening 43a. The water conduit 44 is connected to the tube 4b in the main body device 3, and draws water in the space S from the opening 44a. The water drawn into the opening 44a returns to the cooling device 4 through the tube 4b, is sent out from the tube 4a again, and circulates.
Therefore, the cooling device 4, the tubes 4 a and 4 b, and the water pipes 43 and 44 in the space S constitute a cooling mechanism that cools the distal end portion 11.

Since the cooling water passes through the space S from the distal end side to the proximal end side of the insertion portion 2, the imaging unit 26 surrounded by the space S in the distal end portion 11 is efficiently cooled.
(Function)
A user who is an inspector can use the endoscope apparatus 1 to insert the insertion portion 2 into the inspection target and observe the welding state of the welded portion displayed on the monitor 6.

  The signal processing circuit in the main body device 3 includes a movement control unit that controls the movement of the movable optical filter 33. When the signal processing circuit monitors the brightness of the captured image and detects that a pixel area having a predetermined brightness value or more such as an arc exists in the image area, the signal processing circuit NDs the light incident on the observation window 11a. The electromagnetic valve in the main body device 3 is controlled so as to transmit the optical member 33A that is a filter, and compressed air is discharged from the opening 41a of the air duct 41.

  The air discharged from the opening 41a passes through the gap between the movable optical filter 33 and the inner wall of the filter housing portion 25a, returns from the opening 42a to the main body device 3 through the air conduit 42, and is discharged from the electromagnetic valve to the atmosphere. Is released.

  When the signal processing circuit detects that there is no pixel area having a predetermined luminance value or more in the image area, the electromagnetic valve in the main unit 3 is controlled so that the light incident on the observation window 11a is transmitted through the optical member 33B. Then, the compressed air is discharged from the opening 42 a of the air conduit 42.

  The air discharged from the opening 42a passes through the gap between the movable optical filter 33 and the inner wall of the filter housing portion 25a, returns from the opening 41a to the main body device 3 through the air conduit 41, and is discharged from the electromagnetic valve to the atmosphere. Is released.

  As long as a pixel region having a predetermined luminance value or more such as an arc exists in the obtained endoscopic image, the compressed air continues to be discharged from the opening 41a. At this time, since the endoscope image by the light passing through the optical member 33A, which is an ND filter, is displayed on the monitor 6, the user can check the weld state of the bead.

  Similarly, if a pixel region having a predetermined luminance value or higher such as an arc does not exist in the obtained endoscopic image, the compressed air continues to be discharged from the opening 42a. At this time, a normal endoscopic image is displayed on the monitor 6 by light passing through the colorless and transparent optical member 33B.

  Here, the main body device 3 automatically controls the movement of the movable optical filter 33. However, the main body device 3 is provided with a switch, and the user enters the observation window 11a by operating the switch. The light may be transmitted through either the optical member 33A or 33B.

  As described above, for an endoscopic image including a pixel area with high luminance such as an arc, light from the subject strikes the image sensor 27 through the optical member 33A having an ND filter, so that smear or the like is applied to the image. Does not occur. In addition, for an endoscopic image that does not include an image area having a predetermined luminance value or more such as an arc, light from the subject strikes the imaging element 27 through the optical member 33B that is a colorless and transparent optical glass member. A normal endoscopic image is displayed on the monitor 6.

According to the endoscope apparatus 1 described above, since the movable optical element is provided on the rear side of the objective lens 24, the diameter of the distal end portion 11 of the insertion portion 2 can be reduced, and optical characteristics different from each other. Since the movable optical element is used, the length of the tip portion 11 in the axial direction is shortened, and the user can insert the tip portion 11 even in a narrow place.
(Modification)
9 and 10 are cross-sectional views of the distal end portion 11 as viewed from the distal end side, taken along the line VI-VI in FIGS. 2 and 3, showing a modification of the above-described movable optical filter.

  The movable optical filter 51 of this modification is a movable optical element having a turret 53 to which two optical members 52A and 52B are fixed. The turret 53 is a member that is movable around a shaft member 53 a that is parallel to the axis of the distal end portion 11. The optical member 52A is an ND filter member, and the optical member 52B is a colorless and transparent optical glass member. The refractive indexes of the two optical members 52A and 52B are substantially the same.

A filter housing portion 50 is formed inside the concave portion on the front end side of the housing 25, and the movable optical filter 51 is housed in the filter housing portion 50 so as to be rotatable within a predetermined range around the shaft member 53a. .
Similarly to the two optical members 33A and 33B, the two optical members 52A and 52B are also formed so that light from the observation window 11a passes through the parallel plane.

  When compressed air is discharged from the air duct 41, the turret 53 of the movable optical filter 51 rotates around the axis of the shaft member 53a and enters from the observation window 11a to enter the inward flange portion 23a as shown in FIG. The light emitted from the apertures of the light passes through the optical member 52A, which is an ND filter, and is received by the image sensor 27.

  Further, when compressed air is discharged from the air duct 42, the turret 53 of the movable optical filter 51 rotates around the axis of the shaft member 53a and enters from the observation window 11a as shown in FIG. The light emitted from the opening of the portion 23a passes through the optical member 52B, which is a colorless and transparent glass member, and is received by the image sensor 27.

  That is, the distal end portion 11 has a filter storage portion 50 that is a storage space for storing the movable optical filter 51, and the movable optical filter 51 can be rotated around a predetermined axis in the filter storage portion 50. Yes.

  Also in this modified example, since the movable optical element is provided on the rear side of the objective lens 24, the diameter of the distal end portion 11 of the insertion portion 2 can be reduced, and two regions having different optical characteristics can be provided. Since the movable optical element is used, the length of the tip portion 11 in the axial direction is shortened, and the user can insert the tip portion 11 even in a narrow place.

  As described above, according to the embodiment and the modification described above, an observation apparatus having an insertion portion, which can shorten the diameter in the axial direction and reduce the diameter of the distal end portion of the insertion section, is provided. can do.

  In the embodiment described above, the amount of strong light due to the arc is reduced by the ND filter in the entire visible light range, but only the wavelength region of the arc light is blocked or reduced, and light of other wavelengths is transmitted. A band pass filter or the like may be used.

  That is, the two optical regions that transmit the light of the movable optical element have different optical characteristics as the wavelength of transmitted light, and the region that transmits the light of one optical member does not transmit light of a predetermined wavelength such as arc light. The band-pass filter having characteristics may be an optical member that is transparent and transmits light in the entire visible light region.

  Furthermore, in the above-described embodiment and modification, the imaging unit 26 is built in and fixed to the distal end portion 11 of the insertion portion 2, but the imaging unit 26 is detachable from the distal end portion 11. There may be.

For example, in FIG. 2, the cylindrical member 28 in which the objective lens 30 and the imaging device 27 are incorporated is attached to the housings 34 and 35 from the outside of the insertion portion 2 without bonding and fixing the cylindrical member 28 to the housings 34 and 35. The tip 11 is configured so that it can be fixed.
Furthermore, in the embodiment described above, the cover glass 21 has a parallel plate shape, but may have a wedge shape or a prism shape. In this case, the angle of the observation region can be changed with respect to the axis (or the insertion direction) of the tip portion 11 without increasing the size of the tip portion, and it is possible to meet the demand for side view.

  According to such a configuration, an observation apparatus capable of performing observation while suppressing the amount of arc light by attaching the distal end portion of the insertion portion of a normal endoscope to an adapter having a movable optical member and a cooling mechanism. Can be configured.

  The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Endoscope apparatus, 2 insertion part, 3 main body apparatus, 3a Cooling water supply terminal, 3b Cooling water return terminal, 3c Compressed air input terminal, 3d Video signal output terminal, 3e Power supply input terminal, 4 Cooling apparatus, 4a, 4b Tube, 5 Compressor, 5a Tube, 6 Monitor, 6a Cable, 7 Power Supply, 7a Cable, 8 Workpiece, 8 Member, 8a Bead, 11 Tip, 11a Observation Window, 12 Welding Electrode, 21 Cover Glass, 22 Fixed Frame, 23 tip frame, 23a inward flange, 24 objective lens, 25 housing, 25a filter housing, 25a1, 25a2, 25a3, 25a4 inner wall surface, 26 imaging unit, 27 imaging element, 28 cylindrical member, 29 frame, 30 objective lens, 31 cover glass, 32 optical member, 33 movable optical filter, 33A, 33B optical member, 33C reinforcing member, 33a1 incident side surface, 33b1 exit side surface, 33c1 entrance side surface, 33d1 exit side surface, 34, 35 housing, 36 exterior member, 37 cover member, 41, 42 air conduit, 41a, 42a Opening, 43, 44 Water conduit, 43a, 44a Opening, 50 Filter housing, 51 Movable optical filter, 52A, 52B Optical member, 53 Turret, 53a Shaft member.

Claims (19)

A flexible, elongated insertion portion;
An objective optical system provided at the distal end of the insertion portion;
An image sensor that is provided at the distal end of the insertion portion and receives light transmitted through the objective optical system;
A first region provided between the objective optical system and the imaging device and having a first optical characteristic; and a second region having a second optical characteristic different from the first optical characteristic. A movable optical element that selectively transmits the light transmitted through the objective optical system to the first region or the second region;
An observation apparatus comprising:   The observation apparatus according to claim 1, wherein the movable optical element is moved by the ejected gas so that the light passes through the first region or the second region.   The observation apparatus according to claim 2, wherein the objective optical system has a positive refractive power.   The observation apparatus according to claim 3, wherein two openings from which the gas is ejected are provided in the tip, and are provided outside an optical path in which a light beam is narrowed by the objective optical system. The gas is compressed air;
It has an air source which outputs the said compressed air, The observation apparatus as described in any one of Claim 2 to 4 characterized by the above-mentioned. The tip portion has a storage space for storing the optical element;
The observation apparatus according to claim 1, wherein the movable optical element is capable of reciprocating by sliding along an inner wall of the tip portion forming the storage space.   The observation apparatus according to claim 6, wherein the reciprocating direction of the movable optical element is a direction orthogonal to the optical axis of the objective optical system.   The observation apparatus according to claim 6 or 7, wherein the movable optical element is provided with a reinforcing member that comes into contact with the inner wall. The tip portion has a storage space for storing the optical element;
The observation apparatus according to claim 1, wherein the movable optical element is rotatable around a predetermined axis in the storage space.   The observation apparatus according to claim 1, wherein the first and second regions are regions of an optical member having a parallel plane.   The observation apparatus according to claim 1, further comprising a cooling mechanism provided at the tip portion.   The observation apparatus according to claim 11, further comprising a cooling mechanism control unit that controls the cooling mechanism. An imaging unit having the imaging element;
The observation apparatus according to claim 1, wherein the imaging unit is detachable from the distal end portion. The first optical characteristic and the second optical characteristic are transmittances;
The observation device according to any one of claims 1 to 13, wherein the transmittance of the second optical characteristic is higher than the transmittance of the first optical characteristic.   The observation apparatus according to claim 14, wherein the movable optical element includes an ND filter having the first region. The first optical characteristic and the second optical characteristic are wavelengths of transmitted light,
The observation apparatus according to claim 1, wherein the first optical characteristic has a characteristic of not transmitting a predetermined wavelength.   The observation apparatus according to claim 16, wherein the movable optical element is a band-pass filter that does not transmit the predetermined wavelength in the first region.   The observation apparatus according to claim 1, further comprising a movement control unit that controls movement of the movable optical element.   The observation according to claim 18, wherein the movement control unit controls the movement of the movable optical element based on a luminance value included in an image signal generated from a signal output from the imaging element. apparatus.

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