JP3665442B2 - Electronic endoscope - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic endoscope in which an endoscopic observation image is picked up by a solid-state imaging device arranged at the tip of an insertion portion.
[0002]
[Prior art]
In an electronic endoscope, generally, an objective optical system and a solid-state imaging device for capturing an image formed by the objective optical system are arranged in a distal end portion main body constituting the distal end of the insertion portion. . A CCD (charge coupled device) is widely used as a solid-state imaging device.
[0003]
[Problems to be solved by the invention]
Endoscopes need to be cleaned and disinfected each time they are used to prevent infection. As disinfection methods, chemical disinfection and ethylene oxide gas sterilization have been widely performed so far.
[0004]
However, if disinfectant solution or ethylene oxide gas remains in the endoscope, it may be harmful to the human body or to sterilize Helicobacter pylori and other viruses that cause gastric ulcers at a higher level. High-pressure steam sterilization (autoclave) has been performed.
[0005]
Autoclaves are non-toxic and safe for the human body, but generally, an object to be sterilized is placed in a high temperature environment of about 120 ° C to 135 ° C.
However, in general, a CCD is often damaged when heated to about 80 ° C. or more due to a difference in thermal expansion coefficient between an adhesive used for assembly and an adherend. For this reason, it has been difficult to sterilize electronic endoscopes using an autoclave.
[0006]
In addition, since the pitch between pixels of the CCD is as small as about 6 to 10 μm, if the discharge occurs in the CCD due to static electricity generated while assembling the endoscope, it causes electrostatic breakdown and becomes a defective product. It may become. In such a case, all endoscopes must be disassembled and reassembled from the beginning.
[0007]
Further, when the endoscope is being used, the tip of the insertion portion may be hit or dropped on the floor, and the impact may damage the CCD. In such a case, it is necessary to replace the entire endoscope or to disassemble and repair the entire endoscope in order to replace the CCD.
[0008]
The present invention has been made to improve the above-described disadvantages, and is an electronic device that can easily replace only the solid-state imaging element portion at the tip and can be sterilized by an autoclave. An object is to provide an endoscope.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an electronic endoscope according to the present invention is an electronic device in which an objective optical system and a solid-state imaging device for imaging an image formed by the objective optical system are provided at the distal end of the insertion portion. In the endoscope, a unit to which the objective optical system and the solid-state imaging device are attached is configured to be detachable from the outside at the distal end portion of the insertion portion, and the unit is engaged with the distal end portion of the insertion portion by a bayonet mechanism. It is characterized by stopping.
[0010]
In addition, when the unit is attached to the distal end portion of the insertion portion, at least an electrical contact portion connected to transmit an imaging signal or the like between the distal end portion of the insertion portion and the unit is externally provided. It is preferable to provide a waterproof means for preventing water from entering.
[0011]
In addition, in a state where the unit to which the objective optical system and the solid-state image sensor are attached is removed from the distal end portion of the insertion portion, the insertion is performed so that external moisture does not enter the distal end portion of the insertion portion. It is preferable that the tip portion of the unit has a waterproof structure, and the unit itself has a waterproof structure in which external moisture does not enter the inside.
[0012]
And the protrusion part which protrudes toward the front is provided in the central axis position of the tip part of the insertion part, and the hole through which the protrusion part is inserted is formed in the central axis position of the unit. The unit may be able to rotate around the central axis relative to the distal end portion of the insertion portion when attached to the distal end portion of the insertion portion. In that case, an illumination light guide may be inserted into the protrusion, and a fluid passage may be formed in the protrusion.
[0013]
Further, when the unit is locked to the distal end portion of the insertion portion by the bayonet mechanism, a member connected between the rear end surface of the unit and the distal end surface of the insertion portion that contacts the unit May be arranged, and the connected member may be a light guide for illumination.
[0014]
In addition, a member connected at a fitting portion between the unit and the distal end portion of the insertion portion when the unit is locked to the distal end portion of the insertion portion by the bayonet mechanism is disposed. Alternatively, the connected member may be an electrical contact for transmitting an imaging signal or the like.
[0015]
Further, the positional relationship between the unit and the distal end portion of the insertion portion in the bayonet mechanism may be only one.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
FIG. 2 shows an electronic endoscope. A proximal end of an insertion portion 1 made of a flexible tube is connected to an operation portion 2, and a distal end unit 3 is detachably connected to a distal end portion 1 a of the insertion portion 1. ing. Reference numeral 4 denotes a bending portion that can be bent by remote operation from the operation portion 2.
[0017]
FIG. 1 shows a distal end portion 1a of the insertion portion 1, and 6 is attached to the distal end of a flexible tube (including the bending portion 4), and the distal end unit 3 is detachably connected to the front side thereof. It is a tip cap.
[0018]
The unit body 7 constituting the block of the tip unit 3 is made of, for example, an electrically insulating hard plastic, and an observation window 8 and an illumination window 9 are arranged on the tip surface.
[0019]
An objective optical system 11 is built inside the observation window 8 of the unit main body 7, and an imaging surface of a solid-state imaging device 12 made of, for example, a CCD is disposed on the imaging surface of a subject by the objective optical system 11. Yes. Reference numeral 13 denotes a circuit board on which electronic components (not shown) for driving the solid-state imaging device 12 are attached.
[0020]
Reference numeral 38 denotes a forceps channel inserted into the insertion portion 1, and the tip thereof is fixed to the tip cap 6. In the state shown in FIG. 1 in which the tip unit 3 is coupled to the tip cap 6, the forceps passage hole 39 formed in the unit body 7 is connected to the forceps channel 38 in a straight line. Yes.
[0021]
The distal end portion of the light guide fiber 28 inserted and disposed in the insertion portion 1 is inserted and fixed in the light guide base 28a, and the light guide base 28a is a fitting formed through the unit body 7 in the axial direction. The fitting hole 41 is loosely inserted.
[0022]
The light guide base 28 a is made of, for example, a stainless steel pipe, and the base end portion thereof is watertightly fixed to the front end base 6, and the front end portion is located at the illumination window 9 portion on the front end surface of the unit body 7.
[0023]
In order to secure the fixed state of the light guide base 28 a and the tip base 6, a flange portion 28 b that sandwiches the wall portion at the front end of the tip base 6 protrudes from the light guide base 28 a.
[0024]
An electrical contact 25 connected to the electrical wiring 26 in the insertion portion 1 is provided on the outer peripheral surface of the light guide base 28a via a wiring path formed in the light guide base 28a, and the light guide base 28a is inserted. On the inner peripheral surface of the fitting hole 41 on the unit body 7 side, an electrical contact 24 connected to the wiring of the circuit board 13 via the connection line 23 is provided.
[0025]
A plurality of electrical contacts 25 on the insertion portion 1 side are provided at intervals in the axial direction of the light guide base 28a, and the electrical contacts 24 on the unit body 7 side are arranged at positions corresponding thereto.
[0026]
As a result, in a state in which the tip unit 3 is coupled to the tip portion 1 a of the insertion portion 1, both electrical contacts 24 and 25 are connected, and between the solid-state imaging device 12 and the electrical wiring 26 in the insertion portion 1. Signals (imaging signal, CCD drive signal, etc.) are transmitted.
[0027]
Further, in order to prevent moisture from entering the electrical contacts 24 and 25 from the gap between the fitting hole 41 formed in the unit main body 7 and the light guide base 28a, the inner peripheral portion near the tip of the fitting hole 41 An O-ring 42 for sealing is mounted on.
[0028]
The light guide base 28 a and the fitting hole 41 are provided at the center axis positions of the tip base 6 and the unit body 7. Therefore, the unit main body 7 is rotatable around the light guide base 28a with no deviation around the central axis.
[0029]
The tip cap 6 and the unit main body 7 are bayonet-coupled by a bayonet mechanism 60 when connected.
For example, three bayonet inner claws 61 whose rear cross section (III-III cross section) is shown in FIG. 3 protrude from the front end portion of the tip cap 6, and correspondingly at the rear end portion of the unit body 7. Three bayonet outer claws 62 are formed as shown in FIG. 4 when the unit body 7 is viewed from the rear side (right side in FIG. 1).
[0030]
The inner and outer claws 61, 62 have different widths (angles) of the claws, and there is only one positional relationship in which the claws 61, 62 are engaged. And the groove | channel where the bayonet inner nail | claw 61 fits is formed in the back surface of the bayonet outer nail | claw 62. FIG.
[0031]
Reference numeral 63 shown in FIG. 4 is a stopper for abutting the inner claw 61 when the bayonet is coupled. Further, 51 and 52 shown in FIGS. 3 and 4 are an air supply path and a water supply path, and 39 is the above-described forceps passage hole.
[0032]
When connecting the unit body 7 to the tip cap 6, the inner claw 61 on the tip cap 6 side is inserted between the adjacent outer claws 62 and the outer claws 62 on the unit body 7 side (there is only one position). ) The unit main body 7 is rotated with respect to the tip cap 6 around the light guide cap 28a.
[0033]
Then, as shown in the front sectional view of FIG. 5, the inner claw 61 enters and overlaps the back side of the outer claw 62 in a predetermined direction, and the side of the inner claw 61 comes into contact with the stopper 63. And the air supply passage 51, the water supply passage 52, and the forceps passage hole 39 on both sides of the distal end cap 6 are connected.
[0034]
In this way, the unit body 7 can be bayonet-coupled by rotating the unit body 7 only about one-sixth rotation with respect to the tip cap 6, and the unit can be uncoupled by rotating in the opposite direction. The main body 7 can be removed from the tip cap 6.
[0035]
As shown in FIG. 1, a rubber seal member 47 is lined on the outer peripheral portion of the tip base 6 so that the end surface of the unit main body 7 contacts the entire periphery when the unit main body 7 is connected. .
[0036]
As a result, in a state where the distal end unit 3 is coupled to the distal end portion 1 a of the insertion portion 1, external moisture does not enter the electrical contacts 24 and 25 due to the sealing effect by the O-ring 42 and the seal member 47.
[0037]
Therefore, when the distal end unit 3 is attached to the distal end portion 1 a of the insertion portion 1, there is no possibility that moisture adheres to the electrical contacts 24 and 25 and a signal failure or the like occurs. Further, the seal member 47 also functions as a locking device when the bayonet mechanism 60 is in the connected state.
[0038]
In addition, all the surface parts of the front-end | tip unit 3 are sealed watertight, and a water | moisture content does not penetrate | invade into the inside from the outside. Therefore, the tip unit 3 can be sufficiently cleaned and disinfected in a single state removed from the insertion portion 1.
[0039]
On the other hand, the insertion portion 1 also has a waterproof structure in which no moisture enters the inside from the outside when the tip unit 3 is removed. Therefore, when this electronic endoscope is used for inspection, the insertion unit 1 side (including the operation unit 2) can be placed in the autoclave device with the distal end unit 3 removed, and sterilization using high-pressure steam can be performed.
[0040]
If the tip unit 3 is thus removed and sterilized and sterilized, the solid-state image sensor 12 does not have to be placed in the autoclave device, and the solid-state image sensor 12 can be protected from thermal destruction.
[0041]
Further, since the tip unit 3 in which the solid-state image pickup device 12 is incorporated is detachable from the insertion portion 1, when the solid-state image pickup device 12 is damaged during assembly or use, only the tip unit 3 is replaced. There is no need to add any hand to the insertion portion 1 side.
[0042]
Instead of arranging the light guide base 28a at the central axis position, a pipe that forms a fluid passage for air supply, water supply, suction or the like is arranged, and the unit body 7 can rotate around it. You may do it. Further, the inner claw 61 of the bayonet mechanism 60 may be provided on the unit body 7 side, and the outer claw 62 may be provided on the tip base 6 side.
[0043]
FIG. 6 shows a second embodiment of the present invention, in which the rear end portion of the unit main body 7 is fitted with the tip portion of the tip cap 6, and the electrical contacts 24, 25 is arranged.
[0044]
Further, the distal end surface of the light guide fiber 28 disposed in the insertion portion 1 is located at the distal end surface of the distal end cap 6. Therefore, since the light guide base 28 a does not protrude from the tip of the tip base 6, it is not necessary to arrange it at the axial line position of the tip base 6.
[0045]
A short light guide fiber 16 is independently arranged in the unit main body 7, and the end surfaces of the light guide fibers 28 and 16 face each other when the tip unit 3 is connected to the tip portion 1 a of the insertion portion 1. Thus, the illumination light is transmitted. Other configurations are the same as those of the first embodiment including the bayonet mechanism 60.
[0046]
FIG. 7 shows a third embodiment of the present invention, in which electrical contacts 24 and 25 are arranged on the rear end surface of the unit body 7 and the front end surface of the front end cap 6, and other configurations are the same. This is the same as the second embodiment.
[0047]
In this embodiment, the electrical contacts 25 on the insertion portion 1 side are arranged side by side on the distal end surface of the distal end cap 6. And the front wall part 46 of the front-end | tip base 6 is urged | biased by the compression coil spring 45 provided in the cavity 44 formed in the back so that it may swell forward a little.
[0048]
Therefore, in the state shown in FIG. 7 in which the distal end unit 3 is attached to the distal end portion 1a of the insertion portion 1, the front wall portion 46 of the distal end cap 6 is elastically deformed so as to be returned to a straight state, and the compression coil spring A biasing force of 45 acts in a direction in which the electrical contacts 24 and 25 are brought into contact with each other.
[0049]
The present invention is not limited to the above-described embodiment, and any type of bayonet mechanism 60 may be used.
[0050]
【The invention's effect】
According to the present invention, the unit including the solid-state imaging device can be detached from the distal end portion of the insertion portion by a slight rotation operation by the bayonet mechanism, and only the solid-state imaging device portion can be easily replaced. The electronic endoscope can be sterilized by an autoclave without exposing the image sensor to high heat.
[Brief description of the drawings]
FIG. 1 is a side sectional view of a distal end portion of an insertion portion of an electronic endoscope according to a first embodiment of the present invention.
FIG. 2 is an overall schematic view of the electronic endoscope according to the first embodiment of the present invention.
FIG. 3 is a rear sectional view on the inner claw side of the bayonet mechanism of the first embodiment of the present invention.
FIG. 4 is a rear view of the outer claw side of the bayonet mechanism according to the first embodiment of the present invention.
FIG. 5 is a rear sectional view of the coupled state of the bayonet mechanism according to the first embodiment of the present invention.
FIG. 6 is a side sectional view of a distal end portion of an insertion portion of an electronic endoscope according to a second embodiment of the present invention.
FIG. 7 is a side sectional view of a distal end portion of an insertion portion of an electronic endoscope according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insertion part 1a Tip part 3 Tip unit 6 Tip base 7 Unit main body 12 Solid-state image sensor 24, 25 Electrical contact 60 Bayonet mechanism 61 Inner claw 62 Outer claw

Claims (4)

In an electronic endoscope in which an objective optical system and a solid-state imaging device for capturing an image formed by the objective optical system are provided at the distal end of the insertion portion,
A unit to which the objective optical system and the solid-state image sensor are attached is configured to be detachable from the front of the insertion portion from the front, and is illuminated straight from the central axis position of the insertion portion to the front. The light guide is protruded and a hole through which the illumination light guide is inserted is provided at the center axis position of the unit, and the unit is inserted when the unit is attached to the distal end portion of the insertion portion. An electronic endoscope characterized in that the unit can be rotated around the central axis with respect to the distal end portion of the portion, and the unit is locked to the distal end portion of the insertion portion by a bayonet mechanism. mirror. When the unit is attached to the distal end portion of the insertion portion, external moisture is connected to an electrical contact portion connected to transmit an imaging signal or the like at least between the distal end portion of the insertion portion and the unit. The electronic endoscope according to claim 1, further comprising waterproof means for preventing intrusion. In a state where the unit to which the objective optical system and the solid-state imaging device are attached is detached from the distal end portion of the insertion portion, the external portion of the insertion portion is prevented from entering the distal end portion of the insertion portion. The electronic endoscope according to claim 1 or 2, wherein the tip portion has a waterproof structure. The electronic endoscope according to claim 1, 2, or 3, wherein the unit itself has a waterproof structure in which external moisture does not enter the inside.

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