JP2000028930A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope whose structure is simple, whose diameter of the tip part can be thinned and which can be made inexpensive. SOLUTION: In a tip component member 7 being the sheathing member constituting the tip part 3, an image pickup unit 14 is housed. The unit 14 is constituted so that a lens supporting frame 27 to which an objective lens 12 is previously fitted is fixed by executing centering adjustment for positioning the optical axis of the lens 12 at the central position of the image pickup surface of a solid-state image pickup element chip 13. At this time, the unit 14 is housed by engaging the outside circumferential part of the chip 13 having the largest outside diameter part being larger than the frame 27 with the inside circumferential surface of the component member 7. Besides the component member 7 of the outside circumference side of the frame 27 whose outside diameter part is smaller than the largest outside diameter part is provided with a clearance 40 whose inside diameter is larger than the outside diameter of the frame 27 and which is formed so that the frame 27 can be surely housed in the component member 7 even in the case that positional deviation is caused at the time of the centering adjustment. Thus, the diameter of the tip part 3 can be thinned with the simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens for forming an image of a subject at the tip of an insertion portion and an electronic endoscope having a solid-state image pickup device arranged at the image forming position.

[0002]

2. Description of the Related Art In recent years, endoscopes provided with an illumination optical system and an observation optical system at the tip of an insertion section have been widely used in the medical field and the industrial field. In addition, the charge-coupled device (CC
Electronic endoscopes having a solid-state imaging device such as D) have been widely used.

A conventional electronic endoscope performs centering and focusing of a solid-state image pickup device with respect to an objective lens, as shown in, for example, Japanese Patent Publication No. Hei. It discloses that a lens support frame incorporating a lens as a unit is fixed to a rigid member at the tip.

A second conventional example is disclosed in Japanese Patent No. 26321.
In No. 72, a lens frame having an objective lens attached to the tip is provided separately from a member to which the solid-state imaging device is fixed, and a mechanism for adjusting the lens frame in the axial direction and the vertical direction is provided.

[0005]

Generally, the size of a solid-state imaging device is larger than that of an objective lens. As in the first conventional example, when an imaging unit in which the image sensor is centered with respect to the objective lens is incorporated in the distal end of the scope, the position of the image sensor by centering around the portion where the image sensor is stored is determined. It is necessary to provide a space for absorbing the displacement. That is, as a result, the outer diameter of the distal end portion becomes large.

In the case of the second conventional example, the adjustment is complicated due to the complicated structure, and the price is increased. In addition, depending on the size of the lens and the size of the solid-state imaging device, it is conceivable that the provision of such an adjustment mechanism may increase the outer diameter of the distal end portion.

(Object of the Invention) The present invention has been made in view of the above points, and an object of the present invention is to provide an electronic endoscope in which a distal end portion can be reduced in diameter with a simple structure and can be reduced in cost. And

[0008]

A lens frame on which an objective lens is mounted and a solid-state image sensor having an outer diameter larger than the lens frame are positioned at the center of the optical axis of the objective lens and the center of the image area of the solid-state image sensor. In an electronic endoscope which is incorporated into a distal end portion as a combined imaging unit, the outer periphery of the solid-state imaging device and the inner periphery of the distal end member constituting the distal end portion are fitted to each other, and clearance is provided between the outer periphery of the lens frame and the inner periphery of the distal end member. With this configuration, the solid-state imaging device can be stored in the distal end portion with a small outer diameter in a simple configuration, and the outer diameter of the lens frame is smaller than the outer diameter portion of the solid-state imaging device. The outer diameter of the tip should not increase.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 5 relate to a first embodiment of the present invention, and FIG. 1 shows a structure of a distal end portion of an electronic endoscope according to the first embodiment. 4 to FIG.
Line A, line BB, and line CC are shown, respectively, and FIG. 5 shows a solid-state image sensor chip mounted on TAB.

As shown in FIG. 1, an electronic endoscope 1 according to a first embodiment of the present invention has an elongated insertion portion 2, and a distal end portion 3 and a distal end portion 3 A bending portion 4 that can be bent is provided at the rear end of 3.

The electronic endoscope 1 is used, for example, in the industrial field, and a front end optical adapter 5 for direct viewing shown in FIG. The distal end portion 3 is formed by a substantially tubular distal end member 7 and a tubular joint member 10 fixedly connected to a locking hole 8 provided on the rear end side of the distal end member 7 with a pin 9. An exterior member serving as a housing member is formed, and a light guide 1 for transmitting illumination light into the interior of the exterior member and emitting the illumination light from a front end surface.
1 and the objective lens 12 (the front lens that constitutes the objective lens 12
a, the rear lens is indicated by 12b) and the imaging unit 1 in which the solid-state imaging device chip 13 is centered (alignment between the optical axis center and the center of the image area) and focused.
4 are stored.

Further, the rear end side of the joint member 10 is reduced in diameter in a step-like manner, and a bending piece 15 forming the bending portion 4 is fixed thereto.
To the rear end of the bending piece 15, another adjacent bending piece 15 is rotatably connected by a rivet 16.
Are coated tube 17a, mesh tube (blade) 17b
And the like.

The outer circumference of the front end member 7 on the front end side is slightly reduced in diameter to form a male screw portion 18.
, A fixing ring 19 constituting the direct-view optical adapter 5 is attached by screwing. The direct-view optical adapter 5 includes an objective lens 12 and a light guide 11 on an adapter body 21.
An optical member 22 and an illumination lens 23 are attached at positions facing the lens.

The optical member 22 has an oval shape in which the upper and lower sides of a circular shape are partially cut out. A retaining pin 24 is attached to the adapter body 21 of the upper thick portion, and two illumination lenses are provided on the lower side. 23 are attached.

Objective lens 1 forming imaging unit 14
2 is a front lens 12a having a small outer diameter attached near the front end of the lens support frame 27 via a front lens frame 28;
It is made of a cover glass for protecting the rear lens 12b and the front lens 12a having a large outer diameter. The lens is supported after the center of the optical axis of the rear lens 12b and the center of the imaging surface of the solid-state image sensor chip 13 are aligned (centered). After fixing the frame 27 with an adhesive, the front lens frame 28 to which the front lens 12a is attached is focused and fixed to the lens support frame 27.

The solid-state image pickup device chip 13 is made of TAB (Tape A).
As shown in FIG. 5, the inner lead 31 connected to the solid-state imaging device chip 13 extends vertically, for example, and is slightly smaller than the solid-state imaging device chip 13 on the front surface thereof. A cover glass 30 having dimensions is bonded and fixed to protect the imaging surface. FIG. 5A is a side view, and FIG. 5B is a front view.

The inner leads 31 are bent along the upper and lower side surfaces of the solid-state image pickup device chip 13 and extended to the back side, and the substrate 33 on which the electronic components 32 are mounted and the signal lines 35 are fixed by soldering. Connected to a pattern or the like of the substrate 34.

An insulating adhesive 36 is poured into the back surface of the solid-state image sensor chip 13 to fix and seal the periphery of the substrates 33 and 34 and the periphery of the connection fixing portion at the end of the signal line 35. I have. In addition, an adhesive is also poured around the electronic component 32 to be sealed and fixed. Further, the left, right, upper and lower side outer peripheries of the solid-state imaging device chip 13 are covered with an adhesive 37, and are fixed so as to cover the upper and lower inner leads 31 and are sealed.

The lower section of the image pickup unit 14 is cut off at the lower side of the rear lens 12b and the lens support frame 34 as shown in FIG. Are also cut out to secure a space for disposing the light guide 11.

The image pickup unit 14 in which the rear end of the lens support frame 27 to which the objective lens 12 is attached is fixed to the cover glass 30 of the solid-state image sensor chip 13 mounted with TAB with an adhesive is used. Because of the plate shape, the diagonal portion of the solid-state imaging device chip 13 becomes the maximum outer diameter portion having the maximum outer diameter as shown in FIG.

In order to make the outer diameter of the distal end portion 3 as small as possible, the maximum outer diameter portion is reduced, and the maximum outer diameter portion is formed on the inner peripheral surface of the distal end component member 7 as an exterior member. It is necessary to house the solid-state image sensor chip 13 in a diagonal direction as shown in FIG. Is cut out, or when the solid-state imaging device chip 13 is fixed so as to cover the outer periphery thereof with the adhesive 37, the outer diameter is previously set to be equal to the inner diameter of the inner peripheral surface of the tip component member 7 (by inserting it into a mold). ) A fitting portion 41 having an outer diameter to be fitted to the inner peripheral surface of the distal end component 7 by providing an adhesive 37 or the like is provided.

On the other hand, the lens support frame 27 is
The outer diameter of the front lens 12a side is smaller than that of b, and accordingly, the lens supporting frame 27 also has a small diameter portion 27a formed in the front end side to have a small diameter in a step shape.

The portion of the distal end component 7 facing the outer periphery of the small diameter portion 27a is made thicker than the rear side, and the inner peripheral surface of the portion facing the outer periphery of the small diameter portion 27a has the small diameter. As shown in FIG. 2, a clearance 40 is formed between the small-diameter portion 27a and the opposing inner peripheral surface of the distal end component 7 with an inner diameter slightly larger than the outer diameter of the portion 27a. I have to.

That is, in the present embodiment, when the imaging unit 14 is housed and fixed in the front end component 7, the lens support frame 27 is previously centered on the cover glass 30 of the solid-state imaging device chip 13 mounted on the TAB and the focus is adjusted. The image pickup unit 14 is mounted as described above, and the adhesive 37 for sealing the diagonal outer peripheral portion of the solid-state image pickup device chip 13 which is the maximum outer diameter portion of the image pickup unit 14 is made as small as possible by thinning. A maximum outer diameter portion that is an outer diameter has an outer diameter that fits into the inner peripheral surface of the distal component member 7, and a part of the distal component member 7 that accommodates the lens support frame 27 smaller than the maximum outer diameter portion. The inner diameter of the peripheral surface is set to be larger than the outer diameter of the lens support frame 27, and the solid-state image sensor is aligned with the centering of the lens support frame 27 and the solid-state image sensor chip 13 (relative positioning and fixing of both). Lens to-up 13 support frame 27
It is characterized in that even if there is a displacement or the like, it can be securely housed and fixed in the distal end component 7.

In other words, by fitting the largest outer diameter portion formed by the solid-state image sensor chip 13 portion of the imaging unit 14 to the inner peripheral surface of the tip component member 7 (without a gap), the outer diameter of the tip portion 3 is reduced. Is smaller.

In this case, with the relative positioning and fixing between the solid-state image sensor chip 13 side and the lens support frame 27 side, for example, the lens support with respect to the center position of the solid-state image sensor chip 13 (or the center position of the maximum outer diameter portion). There is a possibility that the center position of the frame 27 may vary individually (the adhesive 37 at the four corners in the diagonal direction of the solid-state imaging device chip 13 shown in FIG. 4 may vary in thickness, etc.). Therefore, even if the center position of the imaging surface of the solid-state imaging device chip 13 and the center position of the lens support frame 27 are fixed without any displacement, the center of the lens support frame 27 is the center position of the maximum outer diameter portion. In addition to the above, when the objective lens 12 is attached to the lens support frame 27, there is a
May slightly vary from the center position of the lens support frame 27).

For this reason, if the inner diameter of the distal end member 7 at the outer peripheral portion of the lens support frame 27 is made to match the outer diameter of the lens support frame 27, there may be a case where the lens support frame 27 cannot be stored due to the variation. However, in the present embodiment, the inner peripheral surface having an inner diameter larger than the outer diameter of the lens support frame 27, that is, the lens support frame 27 is accommodated so that the lens support frame 27 can be securely accommodated even if this variation occurs. In this case, a clearance 40 is formed around it.

In this case, the outer diameter of the lens support frame 27 is smaller than the maximum outer diameter portion, and the distal end member 7 of the outer peripheral portion has a thick enough portion for providing the clearance 40 as shown in FIG. Therefore, even if the clearance 40 is provided, the outer diameter of the distal end portion 3 does not need to be large. Further, as shown in FIG. 3, which shows a cross-sectional position passing through the lens support frame 27 other than the small-diameter portion 27a and the outer peripheral side thereof, for example, the rear lens 12b, the inner peripheral surface of the distal end constituent member 7 is provided. There is a large space between the surface.

The connecting member 10 connected to and fixed to the rear end (proximal end) of the distal end member 7 is provided with a plurality of grooves along the longitudinal direction from the front end (distal end) of the tubular member. The front end side is formed with a plurality of strips having elasticity that can be deformed in the radial direction. And one part on the upper side of the strip,
Pins 9 are attached to two positions of the left-right direction portion with an adhesive or the like so as to protrude from the inside in the radial direction to the outside. Each of the locking holes 8 provided can be engaged and fixed.

That is, the pin 9 is fixed at two positions on the short side and one position on the long side of the solid-state imaging device chip 13. It is provided on the proximal end side of the solder portion between the substrate 34 and the signal line 35 to be formed.

Also, as shown in FIG.
Is a notch 4 in which the front end is cut out.
4 are provided to secure a storage space for the light guide 11.

According to the electronic endoscope 1 configured as described above,
The lens support frame 27 to which the objective lens 12 is attached in advance and T
The image pickup unit 14 in which the AB-mounted solid-state image pickup device chip 13 is positioned and fixed is housed from the rear end side of the front end component member 7, so that, for example, the lens support frame 27 has the front end configuration of the outer peripheral portion as shown in FIG. The member 7 and the clearance 40 can be housed in a formed state, and the solid-state image sensor chip 13 on the rear end side has a maximum outer diameter portion fitted into the inner peripheral surface of the front end component 7 as shown in FIG. Can be stored in a state.

By inserting the front end side of the joining member 10 into the rear end of the tip component member 7, the front end side of the joining member 10 can be easily elastically deformed inward and easily inserted.
The pin 9 provided on the band-shaped portion is fitted into the locking hole 8, and then the pin 9 is pressed to pour the adhesive and sealed, and the image pickup unit 14 is stored and fixed in the distal end portion 3 by a simple operation. can do.

The rigid portion at the front end of the light guide 11 is inserted into the fixing hole of the light guide 11 of the distal end member 7 before the image pickup unit 14 is stored and fixed, and the rigid portion at the front end is fixed. In this case, the portion behind the front end is a separated fiber bundle, and the imaging unit 1
4 can be deformed when stored and fixed, so that it does not get in the way.

In FIG. 2, a clearance 40 formed between the lens support frame 27 and the inner peripheral surface of the distal end member 7 on the outer periphery is an adhesive for sealing after the image pickup unit 14 is stored and fixed. And sealed. 1 and 3, after the imaging unit 14 is stored and fixed, it is sealed with a sealing agent such as an adhesive.

According to the present embodiment, the imaging unit 14 can be stored and fixed in the distal end portion 3 with the distal end portion 3 having a small diameter, and the cost can be reduced with a simple structure.

(Second Embodiment) Next, a second embodiment of the present embodiment will be described with reference to FIG. FIG. 6 shows a solid-state imaging device chip 13 mounted on a TAB according to the second embodiment, and a cover glass 30 for protecting the imaging surface of the solid-state imaging device chip 13.

In the present embodiment, when the cover glass 30 is fixed to the TAB-mounted solid-state image sensor chip 13 with an adhesive, for example, the chamfered portion 45 in which four corners of the rectangular plate-shaped cover glass 30 are cut off obliquely is formed. The provided one is fixed. When the cover glass 30 provided with the chamfered portion 45 is fixed, at least the solid-state imaging device chip 1
The chamfered portion 45 is formed so that the diagonal outer diameter of the cover glass 30 is smaller than the diagonal outer diameter of 3.

For this reason, the maximum outer diameter before the outer peripheral portion is sealed with the adhesive is determined by the diagonal outer diameter of the solid-state image sensor chip 13, and the diagonal outer diameter of the cover glass 30. It is not decided by. By fixing with the cover glass 30 provided with the chamfered portion 45 in this way, even when using a cover glass having a larger size than when fixing with a cover glass without the chamfered portion 45, the maximum outer diameter portion does not need to be increased. I'm done.

Since the inner lead 31 shown in FIG. 6 is bent, for example, along the upper and lower sides of the solid-state imaging device chip 13, the size of the cover glass 30 in the vertical direction is approximately the same as the thickness when the inner lead 31 is bent. Is larger than the size of the solid-state imaging device chip 13 in the vertical direction, the strength of the imaging unit 14 after sealing with an adhesive can be increased in the cover glass 30 portion. Other configurations are the same as those of the first embodiment. This embodiment has substantially the same effects as the first embodiment.

The present invention is not limited to the case where the maximum outer diameter portion of the imaging unit 14 is formed on the solid-state image sensor chip 13 side.
The same can be applied to a case where the lens frame 27 can be formed on the lens frame 27 side.

[Supplementary Notes] A lens frame on which an objective lens is mounted, and a solid-state imaging device having an outer diameter portion larger than the lens frame are formed into an imaging unit in which the center of the optical axis of the objective lens and the center of the image area of the solid-state imaging device are aligned. In an electronic endoscope incorporated in a part, an outer periphery of a solid-state imaging device and an inner periphery of a distal end member constituting a distal end portion are fitted to each other, and a clearance is provided between an outer periphery of a lens frame and an inner periphery of the distal end member. Endoscope. 2. In Supplementary Note 1, the solid-state imaging device is TAB-mounted, and the outer dimensions of the solid-state imaging device chip are the maximum outer dimensions of the solid-state imaging device after the TAB mounting.

3. An electronic unit in which an imaging unit in which an objective lens support frame and a solid-state imaging device having different maximum outer diameter portions are positioned and fixed at a predetermined position in an image area of the solid-state imaging device with an optical axis center of the objective lens is incorporated in a distal end portion of the insertion unit. In the endoscope, the larger outer diameter portion of the objective lens support frame and the solid-state imaging device portion is fitted and stored in the inner peripheral surface of the exterior member at the distal end portion, and the objective lens support frame and the solid-state imaging device are stored. An endoscope wherein a smaller outer diameter portion of the portion is stored and fixed with a clearance to an inner diameter portion of the exterior member. 4. In Addition 3, the larger outer diameter portion is formed by a diagonal portion of a square or rectangular plate-shaped solid-state imaging device.

5. In Supplementary Note 4, the solid-state imaging device unit includes a solid-state imaging device chip, a TAB tape on which the solid-state imaging device chip is mounted, and a cover glass fixed to the TAB tape. 6. In Appendix 5, the maximum outer diameter of the cover glass is smaller than the maximum outer diameter of the solid-state imaging device chip. 7. In Supplementary Note 1 or 3, the clearance is sealed with a sealant such as an adhesive.

8. A lens frame with an objective lens attached,
In an electronic endoscope incorporated in a distal end portion of a solid-state imaging device having an outer diameter portion larger than the lens frame and an imaging unit in which an optical axis center of an objective lens and an image area center of the solid-state imaging device are aligned. The outer periphery of the solid-state imaging device and the inner periphery of the tip component constituting the tip portion are in a fitted state, and the alignment of the outer periphery of the lens frame and the inner periphery of the tip component with the alignment results in displacement of the lens frame with respect to the solid-state imaging device. An electronic endoscope provided with a clearance for accommodating the lens frame even if it occurs.

[0046]

As described above, according to the present invention, the lens frame on which the objective lens is mounted and the solid-state image pickup device having an outer diameter larger than the lens frame are provided with the center of the optical axis of the objective lens and the solid-state image pickup device. In an electronic endoscope which is incorporated into the distal end as an imaging unit that has been aligned with the center of the image area, the outer periphery of the solid-state imaging device and the inner periphery of the distal end constituting member constituting the distal end are fitted, and the objective lens is attached. Clearance is provided between the outer periphery of the lens frame and the inner periphery of the tip component, so that the solid-state imaging device can be stored in the tip portion with a small outer diameter with a simple configuration, and the outer diameter of the lens frame is the outer diameter of the solid-state imaging device. Because it is smaller, the outer diameter of the tip can be prevented from increasing even if clearance is provided on the outer periphery of the lens frame,
Moreover, it can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a distal end portion of an electronic endoscope according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a sectional view taken along line CC of FIG. 1;

FIG. 5 is a diagram illustrating a TAB-mounted solid-state imaging device chip.

FIG. 6 is a diagram illustrating a solid-state imaging device chip and a cover glass according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 2 ... Insertion part 3 ... Tip part 4 ... Bending part 5 ... Optical adapter for direct vision 7 ... Tip construction member 8 ... Locking hole 9 ... Pin 10 ... Joint member 11 ... Light guide 12 ... Objective lens 12a ... front lens 12b ... rear lens 13 ... solid-state image sensor chip 14 ... imaging unit 15 ... curved piece 19 ... fixing ring 21 ... adapter body 22 ... optical member 23 ... illumination lens 27 ... lens support frame 28 ... lens frame 30 ... cover glass DESCRIPTION OF SYMBOLS 31 ... Inner lead 32 ... Electronic components 33, 34 ... Substrate 35 ... Signal line 36, 37 ... Adhesive 41 ... Mating part 40 ... Clearance 45 ... Chamfered part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/225 DF term (Reference) 2H040 DA12 GA03 4C061 AA00 AA29 BB02 CC06 DD00 FF40 JJ06 LL02 NN01 PP08 5C022 AA09 AB43 AC42 AC54 AC77 AC78 AC80 CA02

Claims (1)

[Claims] 1. A lens frame on which an objective lens is mounted and a solid-state imaging device having an outer diameter larger than the lens frame are aligned with the center of the optical axis of the objective lens and the center of the image area of the solid-state imaging device. In the electronic endoscope incorporated in the distal end portion as an imaging unit, the outer periphery of the solid-state imaging element and the inner periphery of the distal end member constituting the distal end portion are fitted to each other, and clearance is provided between the outer periphery of the lens frame and the inner periphery of the distal end member. An electronic endoscope characterized by the above-mentioned.