JP2002224028A - Mounting method of image sensor module of electronic endoscope and electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope provided with an image pickup device at a distal end of an insertion portion, a method of mounting an image pickup device module of an electronic endoscope, which can be performed with high accuracy and efficiency. And an electronic endoscope manufactured by this method. SOLUTION: The relative position of the image sensor module with respect to the rectangular tube portion of the image sensor storage case is adjusted, and the alignment pins 52 and the alignment pin engaging holes 50a of the square tube portion of the image sensor storage case are heated and melted. By joining, the image sensor module is fixed in the rectangular tube portion of the image sensor storage case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope having an image pickup device at the distal end of an insertion portion, in which a prismatic image pickup device module having the image pickup device and peripheral circuits is inserted. The present invention relates to a method for mounting an image sensor module of an electronic endoscope, which is mounted on an image sensor storage case having a rectangular tube portion, and an electronic endoscope manufactured by using this method.

[0002]

2. Description of the Related Art In recent years, instead of a fiber endoscope in which an image formed at the distal end of an endoscope is transmitted as an optical fiber bundle to a hand operation unit and the transmitted image is observed with an eyepiece, an electronic endoscope is used. Endoscopes are being used. An electronic endoscope is an image forming device that forms an image on an image sensor provided at the distal end of the endoscope, converts the image into an electric signal by the image sensor, and converts the electric signal into a hand-held operating unit by means such as a cable. The transmitted electric signal is reconverted into an image, and the image is observed on a display means such as a monitor.

As described above, the electronic endoscope is superior to the fiber endoscope in that the image is once converted into an electric signal, so that it is easy to obtain a still image and to process the image. In general, the number of pixels per unit area of an image sensor of an electronic endoscope is larger than the number of optical fiber bundles per unit cross-sectional area used for transferring an image in a fiber endoscope. The mirror can obtain a more accurate image.

Generally, electronic components such as an image sensor are housed in an image sensor storage case, and the image sensor storage case is fitted into the distal end of an electronic endoscope so that the solid-state image sensor can be mounted at the distal end of the endoscope. Attached to.

FIG. 7 shows the structure of an image sensor storage case in a conventional endoscope. The imaging element storage case 127 includes a metal objective lens barrel 121 in which the objective lens group 128 is inserted, a pipe member 150, and a connection member 151.

Here, the solid-state image sensor 124 and the substrate 143 for driving and controlling the solid-state image sensor 124 are integrated to form an image sensor module 144. The signal cable 145 is connected to the board 143. Since the solid-state imaging device 124 is a substantially square flat plate, the imaging device module 144 is formed in a prismatic shape. The pipe member 150 that accommodates the image sensor module 144 is a rectangular tube-shaped member whose hollow portion is slightly larger than the size of the image sensor module.

On the base end side of the connecting member 151, a pipe member engaging end 151a to be fitted into the pipe member 150 is formed, and on the distal end side of the connecting member 151, an objective lens barrel 121 is inserted. Objective lens barrel engagement hole 151b
Are perforated. Therefore, the imaging element storage case 127
Inserts the objective lens barrel 121 into the objective lens barrel engaging hole 151b of the connecting member 151,
Is assembled by fitting the pipe member engaging end 151a into the pipe member 150. The objective lens barrel 121 and the connecting member 151, and the connecting member 151 and the pipe member 150 are joined by the adhesive 170.

Here, in order to reliably form an image on the solid-state image pickup device 124 of the light beam that has passed through the objective lens group 128,
Optical axis center 181 of objective lens group 128 and solid-state imaging device 1
24 must coincide with the center 182 of the imaging plane. Therefore, in the image sensor storage case of the conventional endoscope, by adjusting the mounting position of the image sensor module 144, the center of the optical axis 181 of the objective lens group 128 and the center 182 of the imaging surface of the solid-state image sensor 124 are adjusted. The wick had gone.

That is, one or a plurality of insulating tapes 146 having electrical insulation properties and having a small thickness and excellent durability are attached to the side surfaces of the image sensor module 144, and the solid-state image sensor 124 has a thickness corresponding to the thickness of the insulating tape. Imaging plane center 18
2 by decentering the image sensor module 14
The mounting position of 4 is adjusted. For example, in FIG. 7, two insulating tapes 146 are attached to the first side surface 144a (upper side in the figure) of the image sensor module 144, and four insulating tapes 146 are attached to the third side surface 144c (lower side in the figure) of the image sensor module 144. Therefore, compared to the case where the same number of insulating tapes are attached to the first side surface 144a and the third side surface 144c of the image sensor module 144, the solid-state image sensor 124 has a thickness of one insulating tape 146. The center 182 of the imaging surface is eccentric in the direction of the first side surface 144a of the imaging element module 144.

During the alignment operation, the signal cable 145 is connected to the monitor to check whether the center 181 of the optical axis of the objective lens group 128 and the center 182 of the imaging surface of the solid-state image sensor 124 match. Is confirmed. Here, if the center 181 of the optical axis of the objective lens group 128 does not match the center 182 of the imaging surface of the solid-state imaging device 124,
From the image sensor storage case 127 to the image sensor module 14
4 is pulled out, the number of insulating tapes 146 attached to each side surface of the image sensor module 144 is changed, the image sensor module 144 is inserted again into the image sensor storage case 127, and the optical axis center 181 of the objective lens group 128 is moved. It was confirmed on the monitor whether the image coincided with the center 182 of the imaging surface of the solid-state imaging device 124. The objective lens group 12
After confirming on the monitor that the center 181 of the optical axis No. 8 coincides with the center 182 of the imaging surface of the solid-state imaging device 124,
The image sensor module 144 and the pipe member 150 are bonded and fixed with an adhesive 171.

Therefore, in the conventional electronic endoscope, the center 181 of the optical axis of the objective lens group 128 and the solid-state image pickup device 12
Until the center 182 of the imaging surface of No. 4 coincides, the above-described centering operation must be repeatedly performed, and the work efficiency is poor.

Also, since the center 182 of the imaging surface of the solid-state imaging device 124 can be decentered only by half the thickness of the insulating tape 146, a plurality of types of insulating tapes 146 having different thicknesses must be used. Instead, it took a lot of time to align the work.

[0013]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a highly accurate centering operation for aligning the center of the optical axis of an objective lens group of an electronic endoscope with the center of the imaging surface of a solid-state imaging device. It is an object of the present invention to provide a method of mounting an imaging element of an electronic endoscope that can be implemented efficiently and an electronic endoscope manufactured by the method.

[0014]

According to a first aspect of the present invention, there is provided a method for mounting an image pickup device module for an electronic endoscope, comprising the steps of: When the image sensor module is inserted into the rectangular tube portion of the image sensor storage case, a centering pin engaging hole is drilled at a position where a side surface of the image sensor module contacts, and the image sensor module is inserted into the image sensor storage case. The centering pin is inserted into each of the centering pin engagement holes, and each of the centering pins is urged against the image sensor module, and By adjusting the insertion depth, the relative position of the image sensor module with respect to the rectangular tube portion of the image sensor storage case is adjusted, and the alignment pins and the alignment pin engaging holes of the square tube portion of the image sensor storage case are adjusted. Heat melting By joining Te, and fixing the image sensor module to the rectangular tube portion of the image pickup element storage case.

That is, since the operation of decentering the center of the imaging surface of the image sensor is performed by changing the insertion depth of the alignment pin, the image sensor module is inserted into the square tube portion of the image sensor storage case. It is possible to decenter the center of the imaging surface of the imaging element while keeping the state. Therefore, according to the method for mounting an image sensor module of an electronic endoscope according to claim 1,
The centering operation for matching the center of the optical axis of the objective lens group of the electronic endoscope with the center of the imaging surface of the solid-state imaging device can be efficiently performed.

Further, since the center of the image pickup surface of the image pickup device can be decentered steplessly irrespective of the thickness of the insulating tape, etc., the center of the optical axis of the objective lens group of the electronic endoscope and the solid object can be accurately detected. Alignment work for matching the center of the imaging surface of the imaging element can be performed.

Further, the alignment pin engaging hole has an internal thread portion, and the alignment pin has an external thread portion which engages with the internal thread portion of the alignment pin engaging hole. By screwing the external thread of the pin to the internal thread of the alignment pin engaging hole,
A configuration for adjusting the insertion depth of the alignment pin may be adopted (claim 2). In this case, the adjustment pin can be moved forward and backward by a driver or the like, so that the alignment work for aligning the center of the optical axis of the objective lens group of the electronic endoscope with the center of the imaging surface of the solid-state imaging device with high accuracy is easier. It can be implemented efficiently.

Further, the alignment pins and the alignment pin engaging holes of the square cylindrical portion of the image sensor storage case are joined by heating and melting, and the image sensor module is fixed in the rectangular cylindrical portion of the image sensor storage case. Thereafter, the image sensor module and the rectangular tube portion of the image sensor storage case are bonded with an adhesive, so that the image sensor module can be firmly bonded to the image sensor storage case.

The method of heating and melting the alignment pin and the alignment pin engaging hole of the square cylindrical portion of the image sensor storage case includes adjusting the alignment pin and the square cylindrical portion of the image sensor storage case. A method of exposing the core pin engaging hole to the arc column (Claim 4), and irradiating a laser to the aligning pin and the aligning pin engaging hole of the square tube portion of the imaging element storage case (Claim 5). is there. In particular, when the alignment pin and the alignment pin engaging hole of the square tube portion of the imaging element storage case are exposed to the arc column and heated and melted, the melting point is instantaneously heated to the melting point. This is advantageous in that it is not heated to a high temperature, and the joint and its surrounding area are not thermally degraded.

[0020]

Embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows the overall configuration of the electronic endoscope according to the embodiment of the present invention. The operating section 2 is connected to the proximal end of the flexible tubular insertion section 1 of the endoscope 1000, and the bending section 4 formed at the distal end of the insertion section 1 is connected to the bending operation knob 3 provided on the operation section 2. By rotating, it can be bent by an arbitrary angle in an arbitrary direction.

A distal end body 10 containing an objective optical system and the like is connected to the distal end of the bending portion 4. In the vicinity of the connection between the insertion section 1 and the operation section 2, a treatment instrument insertion port 5 which is an entrance of a treatment instrument insertion channel inserted and arranged in the insertion section 1 is protrudingly arranged.

A connector 8 is connected to a distal end of a flexible connecting tube 7 connected to a rear portion of the operation section 2. The connector 8 supplies illumination light to a light guide fiber bundle for illumination, which will be described later, and a distal end. It is connected to a light source device and a video processor (not shown) for processing video signals picked up by a solid-state image pickup device built in the main body 10.

FIG. 3 is a front view of the distal end body 10, and FIG.
1 is an observation window for taking in an observation image, 12 is an illumination window for emitting illumination light for illuminating a subject, 13 is an outlet of a treatment instrument insertion channel, and 14 and 15 are an air supply nozzle and a water supply nozzle. .

FIG. 4 is a side sectional view of the distal end portion of the insertion portion 1 in a cross section passing through the respective center lines of the observation window 11 and the illumination window 12. Reference numerals 4 and 10 denote the aforementioned curved portion and distal end body. is there.

A concave lens 17 for widening the light distribution angle of the illumination light is fitted into the illumination window 12, and an emission end of a light guide fiber bundle 18 is arranged inside the concave lens 17. Further, a cover lens 20, which is a first lens of the objective optical system, is fitted into the observation window 11, and an objective lens group 28, a solid-state imaging device 24, and the like are arranged inside the cover lens 20. 2
2 is a YAG laser cut filter, and 23 is a cover glass.

An imaging element storage case 27 is fitted and fixed in a hole formed in the distal end body 10 in the axial direction. The imaging device storage case 27 includes a YAG laser cut filter 22, a cover glass 23, and a solid-state imaging device 2.
4, and a board 43 for driving and controlling the solid-state imaging device 24 are inserted and fixed.

Further, the board 43 is connected to the processor by a signal cable 45 inserted through the insertion section 1, the operation section 2 of the endoscope 1000, and the flexible connection pipe 7.

Further, the objective lens group 28 is housed in the objective lens barrel 21 made of metal. Here, the imaging element storage case 27 includes the objective lens barrel 21 made of metal, a connecting member 51 that is a metal member, and a pipe member 50 that is a square tubular metal member.

On the base end side of the connecting member 51, a pipe member engaging end 51a having a rectangular cross section is formed so as to engage with the hollow portion of the pipe member 50. Further, an objective lens barrel engaging hole 51b into which the objective lens barrel 21 can be fitted and engaged is drilled at the distal end side of the connecting member 51.

Therefore, the image pickup device storage case 27 is configured such that the objective lens barrel 21 is inserted into the objective lens barrel engaging hole 51b of the connecting member 51, and the pipe member engaging end 51a of the connecting member 51 is connected to the pipe member 50. It is assembled by fitting into. Note that the objective lens barrel 2 is attached by the adhesive 70.
1 and connecting member 51, and connecting member 51 and pipe member 5
0 is joined.

The solid-state image sensor 24 is fixed to the tip of a substrate 43 for driving and controlling the solid-state image sensor 24.
Here, the solid-state imaging device 24 and the substrate 43 are fixed in a rectangular cylindrical case formed to be slightly smaller than the cross-sectional dimension of the hollow portion of the pipe member 50, and the imaging device module 44.
Is formed.

Further, the cover glass 23 is
4, and a YAG laser cut filter 22 is bonded to the front end surface of the cover glass 23.

The skeleton of the curved portion 4 is formed by connecting a plurality of node rings rotatably with rivets. And is connected and fixed. Reference numeral 4b denotes an elastic rubber outer tube.

A method of performing the alignment by attaching the image sensor module 44 to the image sensor storage case 27 will be described in detail with reference to the drawings. FIG. 5 is an enlarged cross-sectional view of the imaging element storage case 27, and FIG. 6 is a cross-sectional view taken along line II of FIG.

Each of the side surfaces of the pipe member 50 constituting the imaging element storage case 27 is provided with a centering pin engaging hole 50a. Here, each of the alignment pin engagement holes 50a is Y
AG laser cut filter 22 is used for objective lens barrel 2
When the imaging device module 44 is inserted into the pipe member 50 until the imaging device module 44
It is perforated at the position where it overlaps with. Although not shown in FIGS. 5 and 6, the alignment pin engaging hole 50a
Is threaded.

The base end of the signal cable 45 is connected to a monitor (not shown), so that an image formed on the solid-state imaging device 24 after passing through the objective lens group 28 can be observed on the monitor.

Here, the optical axis center 81 of the objective lens group 28
A scale plate (not shown) on which a cross mark is printed is arranged in front of the objective lens group 28 in order to confirm which position of the solid-state image sensor 24 corresponds to the position. In the scale plate, the cross mark is aligned with the optical axis center 81.
It is arranged to intersect with. Therefore, if the cross mark is displayed at the center of the monitor, the objective lens group 2
8 and the imaging surface center 82 of the solid-state imaging device 24
Means that they match.

Each of the alignment pin engaging holes 50a is screwed with an alignment pin 52 having a thread cut on a side surface. Although not shown in FIGS. 5 and 6,
A slot is formed on the head of the alignment pin 52, and the alignment pin 52 can be freely moved forward and backward with a flathead screwdriver or the like.

Accordingly, by finely adjusting the position of the image sensor module 44 by moving the alignment pin 52 so that the cross mark is displayed at the center of the monitor, the center of the optical axis 81 of the objective lens group 28 can be adjusted. And the center 82 of the imaging surface of the solid-state imaging device 24 can be easily matched.

Next, in order to prevent the alignment pin 52 from being loosened,
The alignment pin engaging hole 50a and the alignment pin 52 are joined. Figure 1
FIG. 5 is a view showing a state where the alignment pin engaging hole 50a and the alignment pin 52 are joined.

That is, the first electrode 201 is placed on the first electrode 201 such that the first electrode 201 comes into contact with the pipe member 50. Further, the second electrode 202 is installed near the centering pin engaging hole 50a. In addition, the periphery of the second electrode 202 is filled with argon gas to prevent oxidation of the joint.

Here, the first electrode 201 and the second electrode 2
02, a predetermined power is supplied between the first electrode 201 and the centering pin engaging hole 50a closest to the second electrode 202 among the portions electrically connected to the first electrode 201.
Then, an arc column 203 is generated between the second electrodes 202. Since the temperature of the arc column is extremely high at 5000 K or more, the alignment pin engaging hole 50a and the head of the alignment pin 52 screwed into the alignment pin engaging hole 50a melt.

Next, the first electrode 201 and the second electrode 2
By stopping the supply of electric power during the period 02 and extinguishing the arc column 203, the molten metal is cooled to its freezing point, and the alignment pin engaging hole 50a and the alignment pin 52 are joined.

After all the alignment pin engaging holes 50a and the alignment pins 52 are joined, the adhesive 71 is inserted into the gap between the image sensor module 44 and the pipe member 50 as shown in FIG.
Is applied, and the imaging element module 44 and the pipe member 50 are
Are joined.

The centering pin engaging hole 50a and the centering pin 5
In order to join the two, the method is not limited to the method of exposing the alignment pin engagement hole 50a to the arc column, and it is sufficient that the alignment pin engagement hole 50a can be selectively heated. Therefore, for example, by irradiating a laser to the alignment pin engagement hole 50a, it is heated and melted,
The alignment pin engaging hole 50a and the alignment pin 52 may be joined.

[0046]

As described above, according to the present invention, the centering operation for aligning the center of the optical axis of the objective lens group of the electronic endoscope with the center of the imaging surface of the solid-state imaging device can be performed with high accuracy. It can be implemented efficiently.

[Brief description of the drawings]

FIG. 1 shows a state in which an alignment pin engagement hole and an alignment pin are exposed to an arc column and joined in an embodiment of the present invention.

FIG. 2 is an overall view of the endoscope according to the embodiment of the present invention.

FIG. 3 is a front view of a distal end of an insertion portion of the endoscope according to the embodiment of the present invention.

FIG. 4 is a side sectional view of a distal end of an insertion portion of the endoscope according to the embodiment of the present invention.

FIG. 5 is an enlarged sectional view of an image sensor storage case for storing the image sensor according to the embodiment of the present invention.

FIG. 6 is a sectional view taken along the line II of FIG. 5;

FIG. 7 is an enlarged sectional view of an image sensor storage case for storing an image sensor in a conventional electronic endoscope.

[Explanation of symbols]

 Reference Signs List 1 Insertion part 21 Objective lens barrel 24 Solid-state image sensor 27 Image sensor storage case 28 Objective lens group 43 Substrate 44 Image sensor module 45 Signal cable 50 Pipe member 50a Alignment pin engagement hole 51 Connecting member 52 Alignment pin 70 Adhesive Reference Signs List 71 adhesive 81 optical axis center 82 imaging plane center 201 first electrode 202 second electrode 203 arc column 1000 endoscope

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akira Sugiyama 2-36-9 Maenocho, Itabashi-ku, Tokyo Inside Asahiko Gaku Kogyo Co., Ltd. (72) Minoru Matsushita 2-36-9 Maenocho, Itabashi-ku, Tokyo No. Asahi Gaku Kogyo Co., Ltd. F-term (reference) 2H040 GA03 4C061 JJ06 LL02 NN01 PP08 5C054 CC07 CE01 HA12

Claims (6)

[Claims] 1. An electronic endoscope having an image pickup device at a distal end of an insertion portion, comprising: a prismatic image pickup device module having the image pickup device and peripheral circuits; and a square tube portion into which the image pickup device module is inserted. A method for mounting an image sensor module of an electronic endoscope, wherein the image sensor module is mounted on an image sensor storage case, wherein the image sensor module is provided on each side surface of a square tube portion of the image sensor storage case. A centering pin engaging hole is drilled at a position where a side surface of the image sensor module contacts when inserted into the image sensor module; the image sensor module is inserted into a rectangular tube portion of the image sensor storage case; A centering pin is inserted into each of the pin engagement holes, each of the centering pins is urged against the image sensor module, and the insertion depth of the centering pin is adjusted to adjust the insertion depth. By adjusting the relative position of the image sensor module with respect to the square tube portion of the image sensor storage case, the alignment pins and the alignment pin engaging holes of the square tube portion of the image sensor storage case are heated and melted and joined, A method for mounting an image sensor module for an electronic endoscope, wherein the image sensor module is fixed in a rectangular tube portion of an image sensor storage case. 2. The centering pin engaging hole has a female thread portion, the centering pin has a male thread portion engaging with the female thread portion of the centering pin engaging hole, 2. The electronic device according to claim 1, wherein an insertion depth of the alignment pin is adjusted by screwing an external thread of the pin into an internal thread of the alignment pin engaging hole. 3. How to attach an image sensor module of an endoscope. 3. The image sensing element module is fixed in the square cylindrical part of the image sensor storage case by heating and melting the alignment pins and the alignment pin engaging holes of the square cylindrical part of the image sensor storage case. The image sensor module of the electronic endoscope according to claim 1, wherein the image sensor module and the rectangular tube portion of the image sensor storage case are joined with an adhesive after the operation. Method. 4. The method according to claim 1, wherein the alignment pins and the alignment pin engagement holes of the square tube portion of the imaging element storage case are exposed to an arc column to be heated and melted. A method for mounting an image sensor module for an electronic endoscope according to any one of the above. 5. The heating device according to claim 1, wherein a laser is applied to the alignment pin and the alignment pin engagement hole of the square tube portion of the imaging element storage case to be heated and melted. A method for mounting an image sensor module for an electronic endoscope according to any one of the above. 6. An electronic endoscope manufactured by using the method for mounting an image sensor module of an electronic endoscope according to claim 1. Description: