JPH0544007B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to a solid-state image sensor (hereinafter referred to as CCD).
The present invention relates to an endoscope that uses an endoscope to image the inside of a body cavity of a living body, and particularly to an endoscope suitable for reducing the diameter of a rigid tip portion and improving the aiming ability of forceps.

(Prior Art) Conventionally, optical fiberscopes, which transmit images by bundling a large number of small-diameter optical fibers, have been widely used as endoscopes for examining and treating digestive organs such as the stomach and intestines within body cavities of living bodies. was. However, this optical fiberscope does not have sufficient resolution;
There were problems such as the optical fiber being easily broken and being colored, making it difficult to obtain high-quality images. Another problem with fiberscopes was that only one person could observe through the eyepiece. In order to solve these problems, in recent years, the tip of endoscopes has been
A CCD is provided, and the CCD images the subject and converts it into an electrical signal.Based on the converted electrical signal, a signal processing circuit generates a color video signal, and corresponds to this color video signal. Electronic endoscopes that display content in color images on a monitor have come into widespread use.

Such an electronic endoscope has the advantage of displaying the diseased area in the subject's body cavity in high resolution color on the monitor, allowing multiple people to observe it at the same time, and contributing to improving the diagnostic ability of the operator. be able to.

FIGS. 3 to 5 show the configuration of a conventional electronic endoscope. In FIG. 3, an electronic endoscope 1 includes a flexible part 2 made of a flexible tube body, a bending part 3 made of a plurality of nodal rings connected in a bendable manner, and a lens system and a CCD built inside. The rigid parts 4 are connected in sequence. In addition, a forceps port, a light guide, an air/water supply tube, etc. are provided penetrating inside the flexible part 2, curved part 3, and hard part 4, and a wire (not shown) is connected to the base of the two flexible parts. An operating section 5 for bending the rigid section 4 at the tip is connected thereto.

The rigid part 4 provided at the tip of the electronic endoscope 1 is
It is constructed as schematically shown in FIGS. 4 and 5. That is, the aforementioned forceps port 6, light guide 7, etc. are opened at the distal end surface of the rigid portion 4.
An objective lens 8 is provided. Further, the CCD 9 is disposed within the rigid portion 4 so that the imaging surface is perpendicular to the optical axis of the objective lens 8, and the optical axis passes approximately through the center of the imaging surface.

In this way, when the CCD 9 stands upright in the rigid part 4, the CPU does not need to judge the imaging situation and perform processing to invert the image, as in the case where the CCD is arranged parallel to the side wall of the rigid part. I can get away with it.

However, in the case of a conventional endoscope device in which the CCD stands upright in the rigid part, compared to the case where the CCD is arranged parallel to the side wall of the rigid part,
There was a problem that the tip of the hard part became large.

(Problem to be Solved by the Invention) That is, according to the conventional electronic endoscope having the configuration described in accordance with FIGS. 3 to 5, the optical axis of the objective lens 8 passes approximately through the center of the imaging surface of the CCD 9. ,and
Since the CCD 9 and the forceps port 6 are arranged at a position where they do not interfere with each other, the objective lens 8 and the forceps port 6 are separated from each other, making it difficult to reduce the diameter of the tip of the rigid portion 4. It was hot. In addition, since the objective lens 8 and the forceps port 6 are separated, the sniping ability of the forceps is reduced when the affected area is imaged through the CCD 9 and the forceps are protruded from the forceps port 6 while being monitored on a monitor. There was also the problem of a significant drop.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an endoscope that can reduce the diameter of the tip of the hard part and improve the sniping ability of the forceps. It is about providing.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a flexible section made of a flexible tube, a curved section connected to the flexible section and configured to be able to bend arbitrarily, and a connection to the tip of the curved section. In the endoscope, the optical lens system and the CCD are disposed inside the endoscope, and a rigid part is formed with a forceps opening passing through the endoscope in the axial direction.
The gist is that an optical means for bending the optical path is provided between the CCD and the optical lens system, and the optical axis center of the optical lens system is brought close to the forceps mouth side.

(Function) In the endoscope according to the present invention, even if the center of the optical lens system provided at the tip of the hard part is brought close to the forceps mouth side, the optical path of this optical system is connected to the optical lens system and the CCD.
bent by an optical means provided between the
Its optical axis passes approximately through the center of the CCD. Therefore, it is possible to reduce the diameter of the tip of the hard part while maintaining the performance of the endoscope, and it is also possible to improve the sniping ability of the forceps.

(Example) FIG. 1 is a sectional view showing a rigid distal end portion of an endoscope to which the present invention is applied, and FIG. 2 is a front view showing the distal end surface of FIG. 1.

In the figures, parts that are the same or equivalent to those of the conventional example shown in FIGS. 4 and 5 are designated by the same reference numerals.
In the rigid portion 4, one forceps port 6 and two light guides 7 are arranged in the outer cylinder 10, close to the cylinder wall and parallel to the axial direction. Further, an objective lens 8 is disposed on the distal end surface side of the rigid part 4 in close proximity to the forceps port 6 so that its optical axis is parallel to the axial direction of the rigid part 4. Furthermore, a CCD 9 is provided within the rigid portion 4 at a predetermined distance from the objective lens 8 so that its imaging surface is perpendicular to the optical axis direction of the objective lens 8. And CCD9 and objective 8
A plate-shaped optical glass 11, which is a feature of the present invention, is provided between the objective lens 8 and the optical axis obliquely to the optical axis of the objective lens 8. The optical glass 11 is made of a LaK glass having a high refractive index and a low dispersion coefficient, for example, and refracts the optical path of the objective lens 8 so that the center of the optical path passes approximately through the center of the imaging surface of the CCD 9. It's summery. Further, the tip of the hard portion 4 has a tapered shape that decreases in diameter toward the tip in a space within the inner diameter that is generated due to the proximity of the objective lens 8 to the forceps port 6.
Although not shown, an air/water supply tube is provided in the rigid section 4 in parallel to the axial direction at a position that does not interfere with the objective lens 8, the optical glass 11, and the CCD 9. It's open.

Next, the operation and effect of this embodiment will be explained.

When the endoscope 1 is inserted into the body cavity of a living body and images of affected areas such as the stomach and intestines are captured through the CCD 9, the optical axis of the objective lens 8 does not pass through the center of the CCD 9;
Since the optical path is refracted by the optical glass 11,
The center of the optical path passes through the center of CCD9. At this time,
Since a portion of the distal end of the rigid portion 4 is tapered to have a smaller diameter, the insertability of the endoscope 1 is improved and the subject can easily swallow the endoscope. In addition, when performing treatment by imaging the affected area via the CCD 9 and protruding the forceps from the forceps opening 6 while monitoring it on the monitor, the objective lens 8
Since it is close to the forceps opening 6, it becomes easier to aim the forceps at the affected area, and the aiming ability of the forceps can be improved.

In the above embodiment, the case where the optical glass 11 is plate-shaped has been described, but the optical glass 11 is not limited to the plate-shape, but may be prismatic-shaped, for example, and the same effect can be obtained.

〔Effect of the invention〕

As explained above, in the endoscope to which the present invention is applied, the optical lens system provided at the rigid distal end of the endoscope is brought close to the forceps mouth side, and the optical axis of the optical lens system is aligned with the CCD by the optical means. Since the tip passes through approximately the center of the forceps, it is possible to make the diameter of the tip of the hard part thinner and improve insertability, and the sniping ability of the forceps can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing the hard part of an endoscope to which the present invention is applied, FIG. 2 is a front view of FIG. 1, FIG. 3 is an external perspective view showing a conventional endoscope, and FIG. The figure is the third
FIG. 5 is a longitudinal sectional view showing the hard part in the figure, and FIG. 5 is a front view of FIG. 4. 1... Endoscope, 2... Flexible part, 3... Curved part,
4... Rigid part, 6... Forceps mouth, 8... Objective lens (optical lens system), 9... CCD (solid-state imaging device),
11...Optical glass (optical means).

Claims (1)

[Claims] 1. A flexible section made of a flexible tube, a curved section connected to the flexible section and configured to be able to bend arbitrarily, and a solid-state image sensor with an imaging surface arranged at a substantially right angle to the axial direction of the curved section. An endoscope comprising: an optical lens system that forms an optical image on the imaging surface of the solid-state image sensor; and a component having a forceps opening extending through the curved part in the axial direction. An endoscope characterized in that an optical means for bending an optical path is provided between the optical lens system and the solid-state image pickup device, and the optical axis center of the optical lens system is brought close to the forceps mouth side. .