JPH11352414A - Objective optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the time and before of replacing a second lens which may be broken with the replacement work by breaking a 1st lens when it is damaged. SOLUTION: An outer circumference of a 2nd lens 7 is formed approximately in a quadrangle inscribed in a inner circumference of a circular lens frame 3, and spaces 8 are secured between the outer circumference of the 2nd lens 7 and the inner circumference of the lens frame 3. In such a manner, it becomes possible to easily take out the 2nd lens by inserting tweezers, etc., into the spaces 8 after having taken out the damaged 1st lens. Moreover, also when an adhesive for fixing the 1st lens 1 to the lens frame 3 flows into the neighborhood of 2nd lens 7 and sticks thereto, it is only at the four points that the outer circumference of the 2nd lens 7 is in contact with the inner circumference of the lens frame 3, therefore, it is easy to remove the stuck adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective optical device for forming an image of a subject constituting an image pickup device or the like provided at a distal end portion of an endoscope, for example.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional example of a configuration of an objective optical device 4 for forming a subject image constituting an image pickup device provided at a distal end portion of an endoscope (not shown).

The objective optical device 4 shown in FIG. 6 includes a first lens 1, a second lens 6, etc., each of which has a circular outer periphery, a diaphragm 2, such as a diaphragm 2, and a spacing ring 5 for maintaining the spacing between the lenses. , And a substantially cylindrical lens frame 3 having a circular inner periphery.

[0004] In this specification, the first lens, the first lens,
The second lens is called. In this specification, a lens including a parallel flat plate is also called a lens.

In the objective optical device 4, a second lens 6, a diaphragm 2, and a first lens 1 are sequentially fitted into a front side portion 3a of the lens frame 3 from the front of the lens frame 3, and the first lens 1 is attached to the lens frame 3.
The lens, the spacing ring 5, the stop, and the like are fitted into the rear side portion 3b of the lens frame 3 from behind the lens frame 3, and the rearmost lens among the lenses fitted into the lens frame 3 is placed. It is assembled by bonding and fixing to the lens frame 3.

At this time, the outer periphery of each of the lenses such as the first lens 1 and the second lens 6 is fitted all around the inner periphery of the lens frame 3.

Incidentally, since the first lens 1 is exposed, the first lens 1 may be accidentally hit or dropped, for example, when using or moving the endoscope, thereby causing damage such as scratches or cracks. is there.

Conventionally, when the first lens is damaged, the first lens 1 is split, the first lens 1 is removed from the lens frame 3, and the first lens 1 is replaced.

When the first lens 1 is split, the second lens 6
In some cases, damage such as scratches or cracks may occur. In such a case, not only the first lens 1 but also the second lens is removed from the lens frame 3 and replaced.

[0010]

However, the outer periphery of the second lens 6 and the inner periphery of the lens frame 3 are fitted all around, and even if the first lens 1 is removed from the lens frame 3, It is difficult to grasp the second lens 6 fitted in the back of the lens 3, and it is difficult to remove the second lens 6 from the lens frame 3.

The outer periphery of the second lens 6 and the inner periphery of the lens frame 3 are fitted over the entire periphery, and the adhesive used to adhere and fix the first lens 1 to the lens frame 3 is applied to the second lens 6. And the adhesive may adhere to the entire periphery of the fitting portion between the outer periphery of the second lens 6 and the inner periphery of the lens frame 3. The first lens 1 may be removed from the lens 3. Also, it takes time and effort to remove the adhesive stuck to the outer periphery of the second lens 6, and it is difficult to remove the second lens 6 from the lens frame 3.

Therefore, for example, when the first lens 1 is damaged, it takes time to replace the second lens 6 which may be broken by the operation of replacing the damaged first lens 1 and replacing the first lens 1. There is a problem that it takes time and effort to repair the lens when the lens is damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and when a lens is damaged, the trouble of replacing another lens which may be damaged by replacing the damaged lens. And an objective optical device capable of improving the restoration efficiency when the lens is broken.

[0014]

A subject image having a lens group consisting of a plurality of lenses and a substantially cylindrical lens frame whose inner periphery is fitted to the outer periphery of each lens constituting the lens group is formed. The at least one lens and the lens frame are formed in such a shape that a gap is formed in a fitting portion between an inner periphery of the lens frame and an outer periphery of at least one lens in the lens group. By doing so, when the lens is damaged, the trouble of replacing another lens that may be damaged due to the operation of replacing the damaged lens is reduced, and the restoration efficiency in the event of lens damage is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings. FIG.
1 to 3 relate to a first embodiment of the present invention, FIG. 1 is a cross-sectional view showing a configuration of an image pickup apparatus, FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 3 is a sectional view taken along line BB of FIG.

(Construction) As shown in FIG. 1, an imaging device 9 used at the tip of an endoscope (not shown)
It mainly includes an objective optical device 4 for forming an image of a subject on the front end side, an imaging device body 13 having a solid-state imaging device 10 for capturing an image of the formed subject on the rear end side, and the like. .

First, the configuration of the objective optical device 4 will be described.

The objective optical device 4 comprises a substantially cylindrical lens frame 3 which is a frame of the objective optical device 4, an optical system fitted into the lens frame 3, and the like.

The lens frame 3 has a front side 3a into which the optical system is inserted from the front side of the lens frame 3, and a rear side 3b into which the optical system is inserted from the rear side.
And so on.

On the front side 3a, a second lens 7, an aperture 2,
The optical system is fitted in the order of the first lens 1, and the entire circumference of the first lens 1 is fixed to the lens frame 3 with an adhesive. It is waterproofed because it is bonded all around.

The outer periphery of the second lens 7 is, for example, as shown in FIG.
2B, or a substantially square shape with chamfered corners of the square as shown in FIG. 2B. Therefore, a gap 8 is provided between the outer periphery of the second lens 7 fitted into the lens frame 3 and the inner periphery of the lens frame 3. As long as this gap 8 can be secured, the outer periphery of the second lens 7 is shown in FIGS.
However, the shape is not limited to the shape shown in FIG.

The rear side 3b includes a lens, an aperture, and an interval ring 5
The entire periphery of the lens located at the rearmost end of the lenses fitted to the rear side portion 3b is bonded to the lens frame 3 all around.

Next, the operation of the objective optical device 4 will be described.

Since the first lens 1 is exposed, the first lens 1 may be erroneously hit or dropped, for example, when the endoscope is used or moved, and may be damaged or damaged.

Conventionally, when the first lens is damaged, the first lens 1 is split, the first lens 1 is taken out of the lens frame 3, and the first lens 1 is replaced.

When the first lens 1 is split, the second lens 7
If the first lens 1 is damaged, the second lens 7 is also moved to the lens frame 3 because the first lens 1 is damaged.
Remove from and replace.

At this time, the first lens 1 and the second lens 7
Is fitted to the front side 3a, so that the first lens 1 and the second lens 7 can be taken out from the front of the objective optical device 4 without removing the lens frame 3 from the imaging device 9. .

Since a gap 8 is provided between the outer circumference of the second lens 7 and the inner circumference of the lens frame 3, by inserting tweezers, wire, or the like into the gap 8, the second gap is formed.
The lens 7 can be easily taken out of the lens frame 3.

The gap 8 can be formed by using tweezers, wire, or the like in addition to removing the second lens 7 for replacement.
It can be used for adjusting the tilt of the second lens 7 and the like.

Further, the adhesive for bonding the first lens 1 to the lens frame 3 may flow into the second lens 7.
Even in this case, the outer periphery of the second lens 7 and the lens frame 3
The portion in contact with the inner circumference of the lens is smaller than the case where it is in contact with the entire circumference. For example, in the case of the second lens 7 having the shape shown in FIG. Therefore, the adhesive is more easily peeled off than in the case where the second lens 7 is in contact with the entire circumference, and the second lens 7 is easily taken out.

As described above, the work of replacing the second lens 7 that occurs with the work of replacing the damaged first lens 1 can be performed efficiently.

Next, the configuration of the imaging device main body 13 will be described.

As shown in FIG. 1, the imaging device body 13 has a solid-state imaging device 10 built therein. The solid-state imaging device 10 includes a chip portion 10b and a cover glass 10a.

A TAB tape 12 is provided at a position rearward from the vicinity of the side surface of the solid-state imaging device 10. This TA
On the surface of the B tape 12, electronic components 17 constituting a drive circuit and the like for the solid-state imaging device 10 are mounted.
An electrode 18 for connecting a cable is arranged on the back surface of the TAB tape 12.

The side and back surfaces of the solid-state imaging device 10 and TAB
The adhesive between the tape 12 and the periphery of the TAB tape inner lead bump bonding portion 12a is reinforced with an adhesive, so that the strength between the solid-state imaging device 10 and the TAB tape 12 is ensured.

A lens 14 is joined to the front surface of the cover glass 10a of the solid-state imaging device 10. This lens 1
4, a light-shielding mask 15 is attached to the rear or front surface by vapor deposition.

A substantially cylindrical solid-state image sensor frame 16 is mounted in front of the solid-state image sensor 10, and the front end of the solid-state image sensor 10 and the rear end of the solid-state image sensor frame 16 are adhesively fixed. The solid-state imaging device frame 16 is
The solid-state image sensor frame 16 and the lens 14 are also bonded and fixed to each other so as to be fitted around the outer periphery of the lens.

The cable is composed of a three-core composite cable 19, a single-core cable 20, and a coaxial cable 21, and these cables extend to the rear of the imaging device 9.

The seven-core composite cable 19 is formed by covering seven coaxial cables and the like with an outermost coat 23. In order to prevent the outermost skin 23 from moving backward, the front end of the outermost skin 23 is covered with a heat-shrinkable tube 22 and fastened.

The three cables are soldered to electrodes (not shown) provided on electronic components 17 provided on the surface of the TAB tape 12 and electrodes 18 on the back surface of the TAB tape 12.

The electrodes 18 on the back surface of the TAB tape 12 are arranged in two rows before and after. In order to prevent a short circuit between the cable connected to the front row electrode 18 and the vicinity of the rear row electrode 18, the cable is soldered to the rear row electrode 18, and then over the cable soldered to the rear row electrode 18. After the insulating tape 24 has been applied to the electrode 18, the cable is soldered to the electrode 18 on the front row.

After connecting a cable to the TAB tape 12 of the solid-state imaging device 10 to an electrode (not shown) provided on the electronic components 17 or the electrode 18 on the back surface of the TAB tape 12, the solid-state imaging device 10 and the TAB tape 12 are connected. An adhesive for reinforcement is applied near the front end of the cable.

From the front end of the solid-state image pickup device frame 16 to a position near the front end of the cable to cover the heat shrinkable tube 22, the image pickup device main body 13 is covered with the heat shrinkable tube 25 and fastened.

When heat shrinking the heat shrink tube 25,
7-core cable 19, single-core cable 20,
The three cables such as the coaxial cable 21 are bundled so as not to interfere with other built-in components provided in an endoscope (not shown) or the like, and then heat-shrinked. is there. In the example of the present embodiment, three cables are arranged as shown in FIG.

The outermost coat 23 of the 7-core composite cable 19, the outermost coat of the single-core cable 20, and the outermost coat of the coaxial cable 21 are as follows:
Since it rubs against other built-in components provided in an endoscope (not shown) or the like, it is formed of a polyester or polyimide material having high abrasion resistance.

The solid-state imaging device frame 16 of the imaging device body 13
Is externally fitted from behind the lens frame 3 of the objective optical device 4,
Position adjustment, such as focus adjustment, is performed, and it is adhesively fixed.

(Effects) The effects of the present embodiment described above are as follows.

Since the first lens 1 and the second lens 7 are housed in the front side 3a of the lens frame 3, the first lens 1 and the second lens 7 can be removed without trouble such as removing the objective optical device 4 from the imaging device 9.
The lens 1 and the second lens 7 can be removed from the front of the objective optical device 4 and replaced.

Since there is a gap 8 between the outer periphery of the second lens 7 and the inner periphery of the lens frame 3, after removing the first lens 1 from the objective optical device 4, tweezers, needles and the like are inserted into the gap 8, The second lens 7 can be easily taken out of the lens frame 3. In addition, the inclination of the second lens 7 can be adjusted.

Since there is a gap 8 between the outer periphery of the second lens 7 and the inner periphery of the lens frame 3, there are few contact points between the outer periphery of the second lens 7 and the inner periphery of the lens frame 3, and the first lens 1 Even when the adhesive for fixing the lens and the lens frame 3 has flowed into the position of the second lens, the number of bonding positions between the second lens 7 and the lens frame 3 is small, and the first lens 1 is removed from the lens frame 3. After that, it is possible to reduce the trouble of peeling off the adhesive stuck between the second lens 7 and the lens frame 3.

As described above, the trouble of replacing the second lens 7 which may be damaged due to the replacement of the damaged first lens 1 can be reduced, and the repairing efficiency when the first lens 1 is damaged can be improved. it can.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. 4 and 5 relate to a second embodiment of the present invention. FIG. 4 is a cross-sectional view showing a configuration of an objective optical device, and FIG. 5 is a cross-sectional view taken along line CC of FIG. is there. The configuration of the parts not described in the present embodiment is the same as the configuration in the first embodiment.

(Configuration) As shown in FIGS. 4 and 5, in the present embodiment, as in the first embodiment, the shape of the outer periphery of the second lens 7 is changed from circular to inward (see FIG. 4). 2
), But instead of forming the second
The shape of the place where the lens 7 is fitted is changed from a circular shape, and a gap 8 is secured between the inner periphery of the lens frame 3 and the outer periphery of the second lens 7. In the example of FIG. 5, the inner periphery of the lens frame 3 is formed in a substantially square shape so as to circumscribe the outer periphery of the circular second lens 7.

(Effects) According to the present embodiment, the same effects as those of the first embodiment can be obtained. It should be noted that the present invention is not limited to only the embodiments described in the first and second embodiments, and various modifications can be made without departing from the spirit of the invention.

The shape of the outer periphery of the second lens 7 in the first embodiment is not limited to a substantially square shape. For example, a substantially hexagon,
It may have a shape such as a substantially octagon.

The shape of the inner periphery of the lens frame 3 in the second embodiment is not limited to a substantially square shape. For example, the shape may be a substantially hexagon, a substantially octagon, or the like.

In the embodiment, the structure for reducing the replacement work of the second lens 7 which may be damaged due to the replacement work of the damaged first lens 1 has been described.
With the replacement of the lens 1, not only the second lens 7 but also other lenses such as the third lens may be damaged. In this case, even if another lens such as the third lens has the same configuration as the second lens 7, it is within the scope of the present invention.

Further, in the embodiment, the structure for reducing the replacement work of the lens when the first lens 1 is exposed has been described. For example, a cover glass (not shown) is provided in front of the first lens 1. When the objective optical device 4 has:
An objective optical device in which the first lens 1 described in the embodiment is replaced with a cover glass (not shown) and the second lens 7 is replaced with a first lens, that is, the first lens 1 has the same configuration as the second lens 7. The configuration of 4 is also within the scope of the present invention.

Therefore, other lenses other than the second lens 7 having the same configuration as the second lens 7 are also within the scope of the present invention.

The objective optical device 4 is used not only in a configuration in which the object image formed by the objective optical device 4 is picked up by the solid-state image pickup device 10, for example, in a configuration like the image pickup device 9, but also in the objective optical device 4. The image of the subject may be transmitted to the image guide fiber by transmitting the subject image.

[0061]

The endoscope constituted by using the objective optical device 4 may be used not only for medical applications but also for various industrial applications. For example, it may be used for inspection of piping.

The technical concept of the objective optical device 4 may be used not only for forming an endoscope but also for forming another device. For example, it may be used in a TV camera.

[Supplementary Notes] (1) A subject image having a lens group composed of a plurality of lenses and a substantially cylindrical lens frame whose inner periphery is fitted with the outer periphery of each lens constituting the lens group is formed. The at least one lens and the lens frame are formed in such a shape that a gap is formed in a fitting portion between an inner periphery of the lens frame and an outer periphery of at least one lens in the lens group. An objective optical device, characterized in that:

(2) The shape of the inner periphery of the lens frame is formed in a circular shape, and the shape of the outer periphery of the at least one lens is changed from circular to inward so as to be inscribed in the inner periphery of the lens frame. The objective optical device according to supplementary note (1), wherein the objective optical device is formed.

(3) The lens frame has a front side and a rear side in which the lens group can be separately fitted from the front and the rear, respectively, and the at least one lens is arranged on the front side. The objective optical device according to supplementary note (2).

(4) The objective optical device according to (3), wherein the at least one lens is a lens located second from the front in the lens group.

(5) An endoscope provided with any one of the objective optical devices described in Supplementary Notes (1) to (4).

[0069]

An object for forming a subject image having a lens group including a plurality of lenses and a substantially cylindrical lens frame whose inner circumference is fitted to the outer circumference of each lens constituting the lens group. In the optical device, by forming the at least one lens and the lens frame in a shape such that a gap is formed in a fitting portion between an inner periphery of the lens frame and an outer periphery of at least one lens in the lens group, When the lens is damaged, the trouble of replacing another lens that may be damaged due to the operation of replacing the damaged lens can be reduced, and the restoration efficiency in the event of lens damage can be improved.

[Brief description of the drawings]

FIGS. 1 to 3 are cross-sectional views illustrating a configuration of an imaging apparatus according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1, illustrating the shape of a lens;

FIG. 3 is a sectional view taken along line BB of FIG. 1 showing an arrangement of cables.

FIG. 4 and FIG. 5 are cross-sectional views showing a configuration of an objective optical device according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along the line CC of FIG. 4, illustrating the shape of the lens frame;

FIG. 6 is a cross-sectional view showing a configuration of a conventional example of an objective optical device used for explaining a conventional technique

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st lens 2 ... Aperture 3 ... Lens frame 3a ... Front side 3b ... Rear side 4 ... Objective optical device 5 ... Spacing ring 6 ... 2nd lens (conventional example) 7 ... 2nd lens 8 ... Gap 9 ... Imaging Apparatus 10: solid-state imaging device 10a: cover glass 10b: chip portion 11: light receiving surface 12: TAB tape 12a: inner lead bump bonding portion 13: imaging device body 14: lens 15: light shielding mask 16: solid-state imaging device frame 17: electronic Parts 18 ... Electrode 19 ... 7-core composite cable 20 ... Single-core cable 21 ... Coaxial cable 22 ... Heat-shrinkable tube 23 ... Outermost skin 24 ... Insulating tape 25 ... Heat-shrinkable tube

Claims (1)

[Claims] 1. An object for forming a subject image having: a lens group including a plurality of lenses; and a substantially cylindrical lens frame whose inner circumference is fitted to the outer circumference of each lens constituting the lens group. The optical device, wherein the at least one lens and the lens frame are formed in a shape such that a gap is formed in a fitting portion between an inner periphery of the lens frame and an outer periphery of at least one lens in the lens group. Characteristic objective optical device.