JPH0515246B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an endoscope using a solid-state image sensor, and particularly to an endoscope that has an improved mounting structure for a solid-state image sensor and an objective optical system at the distal end of an insertion section. Regarding endoscopy.

[Prior Art] A solid-state image sensor used in an endoscope is generally formed in a circular shape with the upper and lower portions cut out in a plane, and a cylindrical mounting member is provided with a cutout that matches the cutout. A solid-state image sensor was attached to the mounting member, and a lens frame was fitted from the front of the mounting member, and a metal shield cylinder was fitted from the rear of the mounting member to fix it to the tip of the insertion tube (Japanese Patent Application Laid-Open No. 1986-
219922).

[Problem to be solved by the invention] The resolution of the image transmitted by the solid-state image sensor is
It is determined by the number of pixels of the solid-state image sensor,
In order to satisfy the resolution required for endoscopes,
With the current state of the art, solid-state imaging devices are inevitably thicker than conventional image guide fibers. This means that the distal end of the insertion portion becomes thicker, reducing ease of insertion and increasing pain to the patient. This is a decline in the basic performance of the endoscope, and how to make the solid-state image sensor thinner is an important factor for endoscopes using solid-state image sensors.

However, as mentioned above, in conventional endoscopes using solid-state imaging devices, the solid-state imaging device has a circular shape with both the upper and lower parts cut out to form a flat surface and is fixed to a cylindrical mounting member. It is not possible to arrange other components, such as an air and water supply conduit, within the circular cross-section of the external shape, and as a result, the distal end of the insertion portion becomes thick, which causes great pain to the patient.

In addition, in order to install the solid-state image sensor and objective optical system at the tip of the insertion tube, three structural members are required: a mounting member, a lens frame, and a shield cylinder.
The distal end became larger, which also caused increased pain to the patient.

This invention eliminates such conventional drawbacks and
It is an object of the present invention to provide an endoscope using a solid-state imaging device that has a thinner insertion portion tip to improve insertability and reduce pain to a patient.

[Means for Solving the Problems] In order to solve the above-mentioned problems, an endoscope using a solid-state imaging device according to the present invention has the following features: In an endoscope in which a solid-state image sensor having an external shape other than a circle is disposed, a metal cylinder is formed to have the same external shape as the solid-state image sensor, and the solid-state image sensor is placed inside the cylinder. At the same time, the rear part of the lens frame to which the objective optical system is attached is formed to have the same external shape as the solid-state image sensor, and is fitted into the front part of the cylinder, and the lens frame is fitted with the cylinder. It is characterized in that the lens frame is fixed within the tip of the insertion section.

[Function] The solid-state image sensor is mounted inside a metal cylinder, and the lens frame is fitted into this cylinder and fixed to the tip of the insertion tube, so only two structural members are needed for fixation, and the lens frame and lens frame are fixed. The rear portion and the cylindrical body are formed to have the same external shape as the solid-state image sensor, and do not block any portion other than the cross section occupied by the solid-state image sensor.

[Embodiment] An embodiment of the present invention will be described based on FIGS. 1 to 4.

FIG. 2 is a plan sectional view of the tip of the insertion portion of the endoscope, and 2 is a metal tip body made of, for example, stainless steel, disposed at the tip of the insertion portion;
The periphery thereof is covered with an insulating cover 3 made of synthetic resin having electrically insulating properties and fixed with adhesive.
4 is provided continuously to and behind the tip portion 1,
It is a curved portion that is bent by remote control, and its most extreme node ring 5 is fitted onto the outer periphery of the rear end portion of the tip body 2, and is connected and fixed with screws 6.
The outer surface of the curved portion 4 is covered with an insulating cover 7 made of rubber that is flexible and has electrical insulation properties, and the insulating cover 7 is fixed to the outer periphery of the rear half of the tip body 2 by adhesive. There is. 8 is the node ring, 9
is a connecting shaft that rotatably connects the joint rings.

10 is a solid-state image sensing device made of, for example, a CCD, 10a is a substantially square light-receiving section, and 10b is a light-receiving section formed on its surface to prevent dust from adhering to the light-receiving section. , for example, a transparent layer made of transparent epoxy resin. The output signal from the solid-state image sensor 10 is then amplified by an amplifier circuit formed on the substrate 11.
A cord 13 passing through the shielded cable 12 is connected to a monitor device via a rear signal processing circuit (not shown). This solid-state image sensor 10
As shown in FIG. 3, it is formed into a circular shape with both the upper and lower portions cut into flat surfaces. 1
0c is an insulating part that seals the wiring and the like on the side of the light receiving part 10a.

An electrically insulating tape 14 made of, for example, synthetic resin is wrapped around the outer periphery of the solid-state image sensor 10 and the substrate 11, and the tape 14 is wrapped around the outer periphery of the solid-state image sensor 10 and the substrate 11. The outer periphery of the cylindrical body 15 is also wrapped with an electrically insulating tape 16 made of, for example, synthetic resin. The cylindrical body 15 is fitted into a through hole 17 formed in the tip body 2, and is pressed and fixed within the tip body 2 by screws 18.

In this way, the insulating tapes 14 and 16 ensure insulation so that no electrical continuity or leakage occurs between the solid-state imaging device 10, the cylindrical body 15, and the tip body 2. Further, the cylinder 15 penetrates the through hole 17 and projects forward thereof, and the tip portion 15a of the cylinder 15 reaches into the hole 3a formed on the back surface of the insulating cover 3, and the insulating tape 16 on the outer periphery is in contact with the insulating cover 3, so that the cylindrical body 15 and the tip body 2 are not electrically conductive.

Further, a silicone resin filler 19 is filled near the end of the shielded cable 12 to completely secure and insulate each member in the vicinity.

The cylindrical body 15 is grounded via the ground wire 20 of the shielded cable 12 to prevent noise from entering the solid-state image sensor 10. On the other hand, the tip main body 2 is not grounded and can be electrically connected to the negative side of the high frequency generator when using the high frequency treatment instrument.

21 is the light receiving section 10a of the solid-state image sensor 10;
These lens groups 21 are adhesively fixed in a metal lens frame 22, and the rear portion 22a of the lens frame 22 is electrically connected to the cylinder 15. It is electrically conductive and securely fitted. Further, reference numeral 31 denotes an aperture of the lens group. This aperture 31 is made of metal, is electrically connected to and fixed to the lens frame 22, and is electrically grounded via the cylindrical body 15. Therefore, the aperture 31 and lens frame 22 serve to prevent noise from entering the solid-state image sensor 10 from the front.

The objective optical system formed by the lens group 21 is close to a telecentric optical system, and the chief ray incident on the solid-state image sensor 10 is almost parallel to the optical axis, and the rearmost lens 21a is used to receive light from the solid-state image sensor 10. It is formed to be as large as the portion 10a. Further, as shown in FIG. 4, the lens frame 22
The cross-sectional shape of the rear portion 22a is formed to be the same as the external shape of the solid-state image sensor 10 so that it can be fitted into the cylindrical body 15, and the lens 21a at the rearmost end is also formed in both upper and lower sides according to the shape. It is formed by cutting out a section. The cut portion of the lens 21a passes the light beam that forms an image on the outside of the opposite side of the light-receiving portion 10a of the solid-state image pickup device, so that the observation light beam is not blocked.

Further, the front end portion 22b of the lens frame 22 is fitted into a hole bored in the insulating cover 3, so that the most advanced objective lens 21b is exposed on the surface of the insulating cover 3. The front end surface of the lens frame 22 is arranged at a position recessed a little (for example, 1 mm) from the surface of the insulating cover 3, and the recess is filled with, for example, an epoxy resin adhesive 23 to provide insulation between the lens frame 22 and the outside. is ensured.

FIG. 1 is a perspective view of the solid-state image sensor 10 mounted inside the cylinder 15 and the lens group 21 mounted inside the lens frame 22, the details of which have already been explained. 15 and lens frame 22 are fitted, positioned with respect to each other, and fixed within the tip body. Therefore, the solid-state imaging device 10 and the lens frame 22 are attached to the tip body 2 by the two structural members (cylindrical body 15 and lens frame 22), and the solid-state imaging device 10 is also electrically shielded.

In the above embodiments, the solid-state image sensor was formed into a circular shape with both the upper and lower surfaces cut into flat surfaces, but the present invention is not limited to this, and the solid-state image sensor may have an external shape other than circular. It includes all shapes.

[Effects of the Invention] According to the endoscope using the solid-state image sensor of the present invention, the solid-state image sensor and the objective optical system are installed at the tip of the insertion section.
It is attached by two structural members, and the area other than the cross section occupied by the solid-state image sensor is not blocked, so air and water supply pipes can be installed in the area that was conventionally blocked by mounting members etc. Other components can be arranged, and the tip of the insertion portion can be made thinner. As a result, the ease of insertion into body cavities is improved, which has the effect of significantly reducing pain to the patient.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the barrel and lens frame of an embodiment of the present invention, Fig. 2 is a plan cross-sectional view of the endoscope tip of the embodiment, and Fig. 3 is a solid-state imaging device used in the embodiment. FIG. 4 is a front sectional view of the rear portion of the lens frame including the rearmost lens. 2... Tip body, 10... Solid-state imaging device, 1
0a... Light receiving section, 15... Cylindrical body, 21... Lens group, 22... Lens frame, 22a... Rear side portion of the lens frame.

Claims (1)

[Scope of Claims] 1. An endoscope in which a solid-state image pickup device having an external shape other than a circle is disposed at the imaging position of an objective optical system attached to the tip of the insertion section, comprising: a metal cylindrical body; is formed to have the same external shape as the solid-state imaging device, and the solid-state imaging device is mounted inside the cylindrical body, and the rear portion of the lens frame to which the objective optical system is mounted is formed to have the same external shape as the solid-state imaging device. 1. An endoscope using a solid-state imaging device, characterized in that the tube is formed into the same shape as the above-mentioned tube, is fitted onto the distal end portion of the tube, and the tube and lens frame are fixed within the distal end of the insertion section. 2. An endoscope using a solid-state image sensor according to claim 1, wherein the outer shape of the solid-state image sensor is formed in a shape obtained by cutting a part of a circular shape. 3. Using the solid-state imaging device according to claim 1 or 2, wherein the rearmost lens constituting the objective optical system is cut to match the external shape of the solid-state imaging device. Endoscope.