JP3216891B2 - Electronic endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope which is inserted into a small-diameter pipe to image the inside of the pipe.

[0002]

2. Description of the Related Art In recent years, endoscopes (scopes or fiberscopes) capable of diagnosing or examining internal organs and the like by inserting an elongated insertion portion into a body cavity have been widely used. I have. In addition, not only for medical use but also for industrial use, boilers, machines, chemical plants, etc.
Alternatively, it is used for observing and inspecting an object inside a machine or the like.

Further, various types of electronic endoscopes using a solid-state image pickup device such as a charge-coupled device (CCD) as an image pickup means are also used.

An electronic endoscope is provided with an objective lens system, a solid-state image pickup device, other electronic components, and a light guide in a rigid end portion. In order to facilitate the assemblability and exchangeability of the endoscope end portion, Japanese Utility Model Application Laid-Open No. 63-158304 discloses that an objective lens system, a solid-state imaging device, and other electronic components are configured in one imaging unit. Is disclosed which enables the assembling. The rear part of the imaging unit is in the shape of a box having a rectangular column shape in the axial direction.

In the case of a flexible endoscope having a flexible insertion portion, a flexible bending portion is provided at the rear of a rigid distal end portion comprising an imaging unit, a light guide for illumination, and the like. Is provided. The bending portion is composed of two or three layers of overlapping members in view of the bending function and its durability, but since it can be formed in a hollow shape, it is easy to insert a light guide or a signal line. , Thinning is possible. On the other hand, since the imaging unit is large, occupies a considerable space, and the light guide is also inserted into the rigid distal end portion, it is longer than the curved portion. As described above, since the space occupied by the imaging unit is large, the insertion space of the light guide in the rigid distal end portion is restricted, and the light guide is inserted at least outside the inner diameter of the curved portion. In other words, when the light guide is inserted into the curved portion via the distal end rigid portion, it is necessary to detour in the outer peripheral direction, approach the insertion path in the central axis direction, and penetrate the inside of the curved portion to avoid the imaging unit. There is.

[0006]

Problems to be Solved by the Invention
Since the imaging unit described in Japanese Patent Publication No. 04 is a box type,
In order not to put a burden on the light guide made of an optical fiber, from the rear end of the imaging unit toward the curved portion,
It is necessary to gradually approach in the direction of the central axis and pass through the inside of the curved portion, and it is necessary to form the rigid portion at the tip end long. As a result, the insertability is deteriorated.

In addition, if the curved portion is formed to have a large diameter, a portion of the entire insertion portion which becomes a large diameter will be unnecessarily long, and the insertability will be degraded against the demand for thinning.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electronic endoscope in which the distal end portion is shortened and the outer diameter of the insertion portion is reduced to improve the insertability. And

[0009]

An electronic endoscope according to the present invention comprises:
An electronic device with an adapter detachably attached to the tip of the insertion section
In the endoscope, it is provided in the adapter, an objective optical system for imaging the site to be examined, at the rear of the objective optical system
A solid-state imaging device disposed at the tip of the insertion portion, and a peripheral circuit disposed behind the solid-state imaging device;
A signal line disposed behind the peripheral circuit, a cover member that covers a tip of the signal line from the solid-state imaging device,
Inserted through the insertion portion, the light guide and which illuminates the site to be examined, it is provided in the adapter, instrumentation on the insertion portion to a proximal end
An adapter cover having a mounting portion to be attached, and the cover portion
It is formed on the wood, and have missing off site to the tip portion of the signal line from the mounting portion near the cover of the light guide
And a notch for being arranged along the member .

[0010]

In this configuration, the cover member is located on the light guide side.
From the back of the solid-state image sensor to the tip of the signal line.
The part is formed in a notched shape and
The light guide is inserted into the chipped space
To effectively utilize the space formed by cutting out
Can be

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 relate to an embodiment of the present invention.
2 is a cross-sectional view of the distal end of the endoscope insertion section, FIG. 2 is an overall configuration diagram of the endoscope apparatus, and FIG.
FIG. 4 is a sectional view taken along a line, and FIG.

An endoscope apparatus 1 shown in FIG. 2 is for observing an inside of a duct, and is an electronic endoscope 2 for outputting an image signal.
And a light source device 3 for supplying illumination light to the electronic endoscope 2.
And a control device 4 for processing an image signal sent from the electronic endoscope 2 and a monitor 6 for displaying a video signal output from the control device 4.

The electronic endoscope 2 has an elongated insertion portion 7,
It has a large-diameter operation section 8 connected to the rear end of the insertion section 7 and a cable 9 extending from a side portion of the operation section 8 and penetrating a light guide and a signal line to be described later.

The insertion section 7 of the electronic endoscope 2 has a hard distal end 11, a bendable bending section 12, and a flexible flexible section 13 in this order from the distal end side. The operation section 8 is provided with a bending operation knob 14. By operating the bending operation knob 14, the bending section 12 bends in the up / down / left / right directions.

A light source connector 16 is provided at a rear end of the cable 9 so that light emitted from a light source lamp (not shown) provided in the light source device 3 is supplied to the light guide. I have. A signal cable 18 extends from the light source connector 16, and the signal line is connected to the connector 1 provided at the rear end of the signal cable 18.
9 is connected to the control device 4.

As shown in FIG. 1, the distal end portion 11 is connected to the bending portion 12 and is detachably replaceable with respect to the distal end body portion 21 having the imaging unit 20 built therein. And an optical adapter 24 having an objective optical system 22 and two illumination optical systems 23 (one is not shown).

As shown in FIG. 1, the distal end main body 21 has
At the distal end side of the outer peripheral surface, a male screw part 25 is formed, and as shown in FIG. 4 , a crank-shaped positioning engagement groove part 40 is provided. On the other hand, the optical adapter 24 has a female screw portion 26 formed on the inner peripheral surface on the rear end side, and
1 and the positioning pin 41.
Is protruding. As shown in FIG. 4 , the engaging groove 40 of the distal end main body 21 guides the positioning pin 41 of the optical adapter 24 from the mounting start groove 40a to the final position groove 40b. Then, at the position of the final position groove 40b, the male screw part 25 of the distal end main body part 21 and the female screw part 26 of the optical adapter 24 are screwed together and positioned and fixed.

For the purpose of weight reduction, the optical adapter 24 is provided with a strong, scratch-resistant material, for example, an adapter cover 27 made of stainless steel on the outside, and a light material, for example, duralumin on the inside of the adapter cover 27. Or, an internal member 28 made of plastic is provided and fixed with screws 29.

The optical adapter 24 has a two-layer structure of the adapter cover 27 and the internal member 28 described above, and is hardly damaged by an impact from the outside. Help me.

On the front surface of the adapter cover 27, an objective cover glass 30 and two illumination cover glasses 31 are provided.
(One is not shown), while the internal member 28 has
Objective cover glass 30 and two illumination cover glasses 31
The objective optical system 22 and the illumination optical systems 23 and 23 are respectively disposed at positions facing the. A lens frame 32 is interposed between the objective optical system 22 and the internal member 28. Even if the lens frame 32 is loosened with respect to the internal member 32, the claw 27a of the adapter cover 27 functions as a stopper, so that the lens frame 32 does not fall off.

On the other hand, the tip body 21 has an outer cover 33a having the male screw portion 25 and outer covers 33b and 33c on the outside, and an inner member 34a on the front side and a rear end on the inside. A fitting member 34b is provided on the side. The fitting member 34b fixes the front end side of the bending tube 35 of the bending portion 12 to the rear end side with screws 36a and 36b.

The inner member 34a has a tip portion of the unit cover 20a of the image pickup unit 20 therein,
Two illumination lenses 35 (one not shown) and two light guides 36 are fitted with the distal ends, respectively.

As shown in FIG. 1, the image pickup unit 20
Unit cover 42 is formed in a hollow substantially cylindrical shape,
In order from the axial front end side, a substantially cylindrical column portion 42a opening forward and the cylindrical portion 4 toward the rear end side in the drawing are shown.
It is formed so that it becomes notched so that it gradually becomes narrower than 2.
And a notch forming portion 42b whose rear end face is open.

The unit cover 42 has a main body cover glass 37a, an infrared cut filter 37b, and a crystal filter 37c arranged in this order from the front end. Further, the unit cover 42 is provided with a solid-state imaging device 38 that converts light incident through the objective optical system 22 of the optical adapter 24 into an electric signal at the rear end of the crystal filter 37c. Further, the unit cover 42 is
The capacitors 39a, 39a and the IC 39b
The peripheral circuit 39 has a solid-state imaging device 38 connected to the input side and two signal lines 43 connected to the output side.

The two signal lines 43, the light guide 36, and the light guide 36 pass through a plurality of lotus-shaped holes at the rear end side of the fitting member 34b, respectively, and
2, the flexible portion 13, the operation portion 8, and the cable 9 are inserted.

FIG. 3 is a cross-sectional view taken along the line AA of FIG. 1, and as shown in FIG.
“b” has a D-shaped cross section, and forms a shape in which a part is cut away from the cylindrical portion 42a to form a space margin. Therefore, the insertion path of the two light guides 36 from the curved portion 12 to the distal end side in the distal end portion 11 gradually moves outward from the position in the curved portion 12 along the notch forming portion 42b of the unit cover 42. In the opposite direction, it is parallel to the axial direction along the cylindrical portion 42a.

The distal end main body 21 containing the image pickup unit 20 includes a main body cover glass 37a, an infrared cut filter 37b, and a crystal filter 37c. Objective optical system 2
2 is provided on the optical adapter 24. Since the optical adapter 24 is configured to be detachable from the distal end main body 21 having an imaging function, it is easy to replace the optical adapter 24 with an adapter having a different optical specification. Therefore, the electronic endoscope 1 does not replace the endoscope main body, and mounts an optical adapter having various kinds of optical specifications on one endoscope to perform endoscope observation. be able to.

The light guides 36, 36 irradiate illumination light from the light source device 3 to a test portion (not shown) via the illumination optical system 23 and the like. The solid-state imaging device 38 receives light from the portion to be measured via the objective optical system 22 and the quartz filter 37c, and converts the light into an electric signal. The electric signal output from the solid-state imaging device 38 is supplied to the control device 4 illustrated in FIG. 2 through the peripheral circuit 39 and the signal line 43. Monitor 6
Receives the video signal output from the control device 4 and displays an endoscopic image of the subject.

In the present embodiment, the signal line 4
Light guides 36, 3 inserted in parallel with 3, 43
6 can be disposed in parallel with the cylindrical portion 42a by arriving at the distal end portion 11 and gradually changing the insertion path outward along the notch forming portion 42b from the narrow portion 42c of the unit cover 42.
That is, the imaging unit 20 includes a notch forming portion 42b formed so that the rear end side of the cylindrical portion 42a is notched diagonally.
And the light guide 3
6, 36 can be inserted. Since the shape of the conventional imaging unit is a block shape as a whole, the light guides 36, 3 are provided between the curved portion 12 and the distal end portion 11.
Although the insertion path of No. 6 had to be changed, the end portion was long formed as a result, but in this embodiment, the end portion 11 can be shortened.

The bending portion 12 has the same outer diameter as the tip portion 11.
By forming the light guides 36, the light guides 36, 36 can be easily positioned near the cylindrical portion 42a of the unit cover 42, but the curved portion 12 becomes unnecessarily thickened. In the present embodiment, it is not necessary to adopt such a structure, and the insertion portion 7 can be made thinner.

FIG. 5 shows an endoscope in which a detection unit of a flaw detection device for searching for a flaw caused by corrosion or the like in a pipeline is integrally formed at the tip of the endoscope.

This flaw detection device 50 is a device for searching for a flaw in a pipe 61 which is a test object based on a change in capacitance. The flaw detection device 50 is provided at the distal end portion 52 of the insertion portion of the endoscope, a plurality of detection portions 55 including a pair of electrodes 53 and a detection circuit 54, and provided outside the endoscope 51;
High frequency oscillator (OSC) 56, multiple amplifiers (AMP)
57, and a flaw detection device 59 including a display device 58.

The high frequency oscillator (OSC) 56 is connected to a pipe 61
The electrode 53 is for detecting a high frequency from the conduit 61.

If the value and frequency of the high-frequency voltage supplied by the high-frequency oscillator (OSC) 56 are constant, the high-frequency current detected from the electrode 53 is proportional to the capacitance between the pipe 61 and the electrode 53. Therefore, as shown in FIG.
If there is a corroded portion 62 in 1, the distance between the conduit 61 and the electrode 53 is widened and the capacitance changes, so that the depth of the corroded portion 62, that is, the degree of flaw can be detected.

The detection circuit 54 rectifies a high-frequency current generated in the electrode 53 by a diode 54a and a capacitor 54b and outputs a DC signal to the amplifier 57, for example, in the circuit configuration shown in FIG. The amplifier 57 amplifies the DC signal output from the detection circuit 54, and the display device 58 displays the DC signal from the amplifier 57, so that the corrosion state in the pipeline 61 can be known.

In the flaw detector 50, the electrode 53 and the detection circuit 54 are provided in the distal end portion 52 of the endoscope, so that the wiring distance between the electrode 53 and the detection circuit 54 can be shortened. The detection accuracy of flaw detection can be improved without being affected by the change in capacitance due to the vibration of the wire or the increase in the wiring distance (noise).

[0037]

As described above, according to the present invention, there is an effect that the insertability can be improved by shortening the distal end portion and narrowing the outer diameter of the insertion portion.

[Brief description of the drawings]

FIG. 1 is a sectional view of a distal end portion of an endoscope insertion section.

FIG. 2 is an overall configuration diagram of an endoscope apparatus.

FIG. 3 is a cross-sectional view taken along line AA of FIG. 1 including an imaging unit.

FIG. 4 is an explanatory view showing a falling-off prevention structure when an adapter is connected.

FIG. 5 is a schematic electrical configuration diagram of the flaw detector.

FIG. 6 is a circuit diagram showing a configuration example of a detection circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 2 ... Electronic endoscope 7 ... Insertion part 11 ... Tip part 20 ... Imaging unit 21 ... Tip main body part 22 ... Objective optical system 24 ... Optical adapter 36, 36 ... Light guide 38 ... Solid-state image sensor 39 ... Peripheral circuit 42 ... Unit Cover 42b: Notch forming part 43, 43: Signal line

Claims (1)

(57) [Claims] An adapter is detachably attached to a distal end of an insertion portion.
In the electronic endoscope to be mounted, the
It is an objective optical system for imaging a measurement site, and the solid-state image sensor which is arranged at the distal end portion of the insertion portion a rear side of the objective optical system is arranged behind the solid-state imaging device Peripheral circuit, a signal line disposed behind the peripheral circuit, a cover member for covering a distal end of the signal line from the solid-state imaging device, and a light for illuminating a portion to be inspected through the insertion portion. A guide , provided on the adapter, at the proximal end
Adapter cover having a mounting part to be mounted on the insertion part
When it formed in the cover member, and have missing off site from the mounting portion near to the tip of the signal line, the write
Notch for positioning the guide along the cover member
An electronic endoscope comprising: