JPH0445179B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an endoscope using a solid-state image sensor, in which an endoscope image signal is obtained using a solid-state image sensor.

[Prior art]

Conventionally, when an endoscope configured to obtain endoscopic signals using a solid-state image sensor is used together with an electric scalpel, for example, high-frequency noise generated from a snare during its operation may be generated by the solid-state image sensor. It mixes in as noise in the image signal sent to the endoscope monitor TV.
There was an inconvenience that the upper monitor image was unclear.
This may interfere with the treatment of the affected area with the electric scalpel, which may lead to serious consequences.

〔the purpose〕

Therefore, an object of the present invention is to obtain image signals from a solid-state image sensor without being affected by high-frequency noise, even if there is a high-frequency noise source such as an electric scalpel near the tip of an endoscope that incorporates a solid-state image sensor. An object of the present invention is to provide an endoscope using a solid-state imaging device that can be obtained.

〔overview〕

According to this invention, the solid-state image sensor is housed at the bottom of a metal cylinder with a bottom, and the dimensions of the aperture of the metal diaphragm of the optical system, which is electrically integrated with the metal cylinder, can be measured from this opening. Since the distance is set smaller than the distance to the solid-state image sensor, high-frequency noise generated from a nearby electric scalpel does not reach the solid-state image sensor inside the metal cylinder, and a clear monitor image can be obtained. A scope will be provided.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. In FIG. 1, a frame 11 of an endoscope distal end 10 is made of synthetic resin, and a metal tube 12 in the shape of a cylinder with a bottom is provided on this frame 11. A lens 13 constituting an optical system is provided at the opening of the metal tube 12, and a solid-state image sensor, such as a CCD, is provided at the bottom.
14 are provided. The maximum dimension of this optical system, that is, the lens 13 provided at the opening of the metal tube 12
The diameter A of the opening of the CCD 14 is
is determined to be smaller than the distance B to the surface. Moreover, this diameter A is set to be equal to or smaller than the wavelength λ of high frequency noise generated from an electric scalpel (not shown). Therefore, the distance B is set longer than this wavelength λ.
As a result, although the optical system part from the lens 13 to the CCD 14, that is, the front of the CCD 14, is not covered with metal, high frequency noise from the electric scalpel is prevented.
The light does not reach the CCD 14, and the CCD 14 is substantially shielded.

A CCD output signal line 15 and a power supply line 16 are led out from the bottom of the metal cylinder 12, and shield lines are used for both of these lines. or,
A light guide 17 for object identification is provided in the frame 11 of the endoscope distal end portion 10 .

In the above configuration, light from the endoscope light source is irradiated from the light guide 17 toward the subject. A reflected light image from the subject is formed on the light receiving surface of the CCD 14 through an optical system including a lens 13, and an image signal of the subject is obtained on an output signal line 15.
This image signal is sent to an endoscope monitor, and a subject monitor image is obtained. Here, when a high frequency current is passed through a snare to treat a subject with the snare, high frequency noise is generated from the snare. This high-frequency noise slightly penetrates into the metal cylinder 12 through the opening of the lens 13, but the diameter A of this opening is set to be shorter than the wavelength λ of the high-frequency noise, and the depth B is set so that it satisfies the relationship A<B. Therefore, the infiltrated high frequency noise does not reach the CCD 14. Therefore, high frequency noise will not be mixed into the image signal generated from the CCD 14. Note that shield lines are used for both the power supply line 16 and the output signal line 15 for the CCD 14, so that a clear monitor image that is not affected by high frequency noise can be obtained.

In the embodiment shown in FIG.
is formed electrically integrally with the metal tube 12 using a metal material. The aperture of this diaphragm 12A, that is, the CCD
The diameter C of the aperture of the optical system 14 may be formed to a size corresponding to the aperture size A of the embodiment shown in FIG.
That is, this diameter C is set to be equal to or greater than the wavelength of high frequency noise generated from the electric scalpel. Therefore, from this aperture of 12A
The distance D to the CCD 14 may be set to the relationship D>C. The other parts of the embodiment shown in FIG. 2 are constructed in the same manner as the embodiment shown in FIG. 1, and their explanation will be omitted.

In the embodiments shown in FIGS. 1 and 2, a shield line 15 is used to derive signals from the CCD 14. As another derivation method, for example, a CCD inside the metal tube 12 can be used.
If the output of 14 is converted into an optical signal using an LED or the like and led out to the outside using a light guide, it becomes unnecessary to use the shield line 15.

〔Effect of the invention〕

As described above, according to the present invention, a fixed image sensor is housed in a metal tube provided at the tip of an endoscope, and the aperture A of the optical system in the metal tube and the distance B from the aperture to the solid-state image sensor Since A<B and the wavelength λ of the high frequency noise from the electric knife is set so that λ≧A, high frequency noise will not be mixed into the image signal from the solid-state image element. Further, since the optical system provided in front of the solid-state image sensor does not have any part that obstructs light entering the solid-state image sensor, a bright endoscopic image can be obtained on a monitor, for example.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of the main part of one embodiment of an endoscope according to the present invention, and FIG. 2 is a sectional view showing the structure of the main part of another embodiment. 10... endoscope tip, 11... frame, 12...
...Metal tube, 13...Lens, 14...CCD, 1
5...Output line, 16...Power line, 17...
...Light guide, A...Aperture dimension, B...Depth dimension.

Claims (1)

[Claims] 1. A bottomed cylindrical metal tube provided at the tip of an endoscope, a solid-state image sensor provided at the bottom of the metal tube, and an optical system provided in the metal tube. , a metal diaphragm located in front of the solid-state image sensor and electrically integrated with the metal tube, the distance from the aperture of the diaphragm to the solid-state image sensor being set larger than the aperture of the diaphragm. An endoscope using a solid-state image sensor, characterized in that: