JPH0532812Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to the tip of an endoscope, and particularly relates to an improvement of the tip of an endoscope using a solid-state image sensor.

[Prior Art] The output end of a light guide fiber used for endoscope illumination generally has a circular cross section to match the shape of a lens (illumination window) for expanding the light distribution angle placed on the end face. The cross-sectional shape is maintained and the tip is drawn toward the rear of the tip body. this is,
The same applies to endoscopes that use solid-state imaging devices; a solid-state imaging device is provided at the imaging position of the objective optical system within the main body of the distal end, and a light guide fiber with a circular cross-section is attached to the solid-state imaging device. It was placed along.

[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 tip of the insertion section thinner is an important factor for an endoscope using a solid-state image sensor.

However, as mentioned above, the tip of a conventional endoscope has a light guide fiber with a circular cross section arranged along the solid-state image sensor, so the tip body is at least as large as the thickness of the solid-state image sensor. The thickness plus the diameter of the light guide fiber is required.
As a result, the tip of the insertion portion becomes thicker, which has the disadvantage of causing great pain to the patient.

This invention eliminates such conventional drawbacks and
It is an object of the present invention to provide a distal end of an endoscope that uses a solid-state image pickup device, has a narrower distal end of an insertion portion, improves insertability, and causes less pain to a patient.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the tip of the endoscope according to the present invention has a circular shape at the imaging position behind the objective optical system in the tip body. In the distal end of an endoscope, a solid-state image sensor formed in a cross-sectional shape with a part cut out is provided, an illumination light guide fiber is arranged along the solid-state image sensor, and its output end is arranged in front, The light guide fiber is formed to have a circular cross-sectional shape near its output end, and the cross-sectional shape is changed within the tip body, so that the light guide fiber has a circular cross-sectional shape in the vicinity of the solid-state image sensor in the vicinity of the solid-state image sensor. It is characterized in that it is formed in a flat cross-sectional shape along the defective portion and is disposed in the defective portion of the solid-state imaging device.

[Function] Since the cross-sectional shape of the light guide fiber is made flat near the solid-state image sensor inside the tip body, it is possible to keep the diameter of the tip body below a certain level while keeping a certain amount of light inside the tip body. A guide fiber can be inserted and placed therethrough.

[Embodiment] An embodiment of the present invention will be described based on FIGS. 1 to 3.

FIG. 2 is a front view of the distal end of the endoscope, and FIG. 1 is a cross-sectional view taken along the line 1, in which 1 is the distal end main body provided at the distal end of the insertion section, and the rear half 1a is Made of metal such as stainless steel,
The front half portion 1b is made of electrically insulating synthetic resin. Reference numeral 2 denotes a curved portion that can be bent freely by remote control, and its most advanced node ring 3 is connected to the rear end of the tip body 1 by screws or adhesive. 4 is a flexible insulating tube that covers the curved portion, and the metal portion of the tip main body 1 is also covered by this insulating tube 4.

5 is a lens group which is an objective optical system, and 6 is a solid-state image sensor arranged at an imaging position behind the objective optical system 5. As shown in FIG. 3, the solid-state image sensor 6 is formed into a circular shape with both the top and bottom portions cut out to form a plane. Further, a mounting cylinder 7 is formed in the same shape as this, and the solid-state image sensor 6 is mounted and fixed inside this mounting cylinder 7. Further, the solid-state image sensor 6 is provided in the rear half portion 1a of the tip body.
A through hole 8 is formed into which the outer peripheral part of the solid-state image sensor fits, and the through hole 8 is expanded upward and downward to align with the defective part of the solid-state image sensor, and a space is formed between the mounting cylinder 7 and the through hole 8. 9 is formed.

6a is a light-receiving part of a solid-state image pickup device having a substantially square cross-sectional shape, 6b is a seal part sealing wiring etc. on the side thereof, and 6c is a seal part formed on the surface of the light-receiving part to prevent dust from adhering to the light-receiving part. In addition, it is a transparent layer made of, for example, a transparent epoxy resin. The output signal from the solid-state image sensor 6 is amplified by an amplifier circuit formed on the substrate 10, and is sent to the monitor device via a rear signal processing circuit via a cord 11a passing through the shielded cable 11. connected (not shown). In addition, the mounting cylinder 7
is grounded via the ground wire 11b of the shielded cable 11.

The objective optical system 5 is close to a telecentric optical system, and the chief ray incident on the solid-state image sensor 6 is almost parallel to the optical axis, and the rearmost lens 5a is almost parallel to the light receiving part 6a of the solid-state image sensor. Largely formed. The other lenses are formed thinner than the rearmost lens 5a, and all the lenses are housed in a metal lens frame 12 whose rear end 12a is thickened to match the shape of the lens group. The front thin part of this lens frame 12 is fixed to the tip main body 1, and the thick rear end part 12a is formed in the same external shape as the solid-state image sensor 6 and is fitted and fixed to the mounting cylinder 7. has been done.

The illumination light guide fiber 13 is arranged along the solid-state image sensor 6 and the objective optical system 5. Output end 13 of the light guide fiber
a is arranged in front of the solid-state image sensor 6 and in line with the objective optical system 5 . Reference numeral 14 denotes a concave lens for expanding the light distribution angle, which is disposed at the output end 13a of the light guide fiber. As shown in FIG. 2, three concave lenses 14 are provided, and the output end 13a of the light guide fiber is formed to have a circular cross section slightly smaller than the concave lenses 14, and is disposed on the rear side of each concave lens 14. .

In the vicinity along the narrow part of the lens frame 12 (range indicated by A in FIG. 1), that is, in the vicinity of the output end 13a of the light guide fiber, the light guide fiber 13 is solidified to have the same circular cross section as the output end surface. The cross-sectional shape is changed within the tip main body 1, and a third
As shown in the figure, it is formed flat and is placed in the space 9 between the tip main body 1 and the mounting cylinder 7, along the missing portion of the solid-state image sensor 6. In this flat part, the light guide fiber 13
may be hardened into a flat shape in advance, but it should be left in a flexible and freely unraveled state before assembly, so that it can be formed into a flat shape by being sandwiched and placed in the space 9. You can also do this.
Note that the light guide fibers forming the two lower output end portions 13a are one at the rear flat portion 13b.
They are collected as one bundle. In the inside of the curved part 2 (range shown by C in FIG. 1) further behind the flat part 13b, the light guide fiber 13 is inserted in a relaxed and flexible state so as to have a free cross-sectional shape. .

16 is a suction port formed in the tip body 1. A hard pipe 17 made of, for example, stainless steel is connected to the suction port 16 and is fixed to the front half 1b of the tip body. The pipe 17 passes through the space 9 formed at the periphery of the tip main body 1 and connects to a flexible tube 18 made of, for example, tetrafluoroethylene resin, which communicates with an external suction device at the rear thereof. It is connected.
The rigid pipe 17 has a circular cross section near both ends, but the section passing through the space 9 has a slightly flattened elliptical cross section, as shown in FIG. The rigid pipe 17 has a rear end bent inward and is connected to the flexible tube 18, which is arranged directly toward the rear, by a pipe connecting elbow 19. There is. This elbow 19 is made of stainless steel, for example, and has holes drilled at angles from different directions so as to communicate at the middle part, and the hard pipe 17 is fixed to this elbow 19 by, for example, soldering. , flexible tube 1
8 are joined by adhesive.

In this embodiment, the flexible tube 18
The inner diameter of the hard pipe 17 is larger than the outer diameter of the hard pipe 17, so that a sufficient amount of suction can be obtained and the diameter of the tip body 1 is not made as large as possible. By connecting the rigid pipe 17 and the flexible tube 18 with the elbow 19 in this way, the pipe 17 and the tube 18 can be connected at any angle, and the inner and outer diameters of both can be adjusted. No matter how different they are, they can be reliably connected. Further, the flexible tube 18 communicates with a known forceps insertion port in an operation section (not shown), and the flexible tube 18 can also be used as a forceps channel.
It is designed so that forceps and other treatment tools can be protruded from the handle.

In the above embodiment, the light guide fiber near the output end 13a is formed to have a circular cross section, but it does not need to be strictly circular, and may include polygons and other shapes close to circular.

[Effect of the invention] According to the distal end of the endoscope of the present invention, the light guide fiber is formed in a flat cross-sectional shape along the defective part of the solid-state imaging device in the vicinity of the solid-state imaging device within the main body of the distal end. Since the light guide fiber is placed in the defective part of the solid-state image sensor, a certain amount of light guide fibers can be attached to ensure a sufficient amount of illumination light, and the diameter of the tip body can be made thinner than in the past. As a result, it is easier to insert into body cavities, etc.
It has the effect of significantly reducing the pain inflicted on patients.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention (a sectional view taken along the - line in Fig. 2), Fig. 2 is a front view of the embodiment, and Fig. 3 is a sectional view taken along the - line in Fig. 1. be. 1... Tip body, 5... Objective optical system, 6...
Solid-state image sensor, 6a... Light receiving part, 7... Mounting cylinder, 9... Space, 13... Light guide fiber, 13a... Outgoing end, 13b... Flat part, 1
4...Concave lens.

Claims (1)

[Claims for Utility Model Registration] A solid-state image sensor formed in a cross-sectional shape with a part of a circular shape is provided at the imaging position behind the objective optical system in the tip body, and a light guide fiber for illumination is provided. In the distal end of the endoscope, which is disposed along the solid-state image sensor and has its output end in front, the light guide fiber is formed to have a circular cross-sectional shape near the output end;
The cross-sectional shape is changed within the tip main body, so that in the vicinity along the solid-state image sensor, the cross-sectional shape is flattened along the defective part of the solid-state image sensor, and the cross-sectional shape is formed into a flat cross-sectional shape along the defective part of the solid-state image sensor, and the cross-sectional shape is arranged in the defective part of the solid-state image sensor. A distal end portion of an endoscope characterized by: