JP2003126029A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a decline of shield efficiency caused by thickness of a shield member or impedance of the shield member, and to reduce emission of unnecessary radiant noise and interference of unnecessary radiant noise completely. SOLUTION: A metal meshed tube 17 is exposed and is electrically connected to an electric shield member 19 at the peripheral part of a CCD 14 by plane-to- plane contact at the front end side of an image cable 15, and the metal meshed tube 17 is exposed and is electrically connected to a third shield member 20 in a CCU connector 11 by plane-to-plane contact at the back end side of the image cable 15. A second shield member 21 is provided at the outside of an image cable 15 in an insertional part 2, an operational part 3, a universal cord 4, a light guide connector 9, and a camera cable 10, and the second shield member 21 is electrically connected to the third shield member 20 by plane-to-plane contact. Electrically connecting the third shield member 20 to reference potential 25 of a patient circuit 24 through plane-to-plane contact can reduce emission and interference of unnecessary radiant noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus that reduces the emission of unwanted radiation noise and the mixing of unwanted radiation noise.

[0002]

2. Description of the Related Art Generally, in an electronic endoscope, an EMC is used.
As a countermeasure, in order to reduce the emission of unwanted radiation noise from the electronic endoscope and the mixing of unwanted radiation noise into the electronic endoscope, it is necessary to shield the built-in electronic components.
For example, it has a plurality of input / output signal lines in the center, the outer periphery of the bundled signal lines is covered with a metal mesh tube for shielding, and the outer periphery is further covered with an outer shield made of an electrically insulating material. In the signal cable, by connecting the metal mesh tube for shielding to the reference potential of the signal processing means,
The emission and mixing of unwanted radiation noise is reduced.

The applicant of the present invention has also filed Japanese Patent Application Laid-Open No. 7-18485.
Japanese Patent Laid-Open No. 2 (1994) proposes a technique for stabilizing the potential level and effectively reducing unnecessary radiation noise by electrically connecting the metal members of the endoscope to a predetermined potential.

[0004]

However, in the endoscope, there is a demand for reducing the outer diameter of the insertion portion to be inserted into the body cavity of the patient. To meet this requirement, it is desirable to make the signal cable with the shield member as thin as possible. However, if the signal cable is made thin, it is possible to secure a sufficient radial space for the metal mesh tube for shielding. It will be difficult. For this reason, the thickness of the metal mesh tube for shielding becomes thin and the shielding ability cannot be sufficiently ensured, and the emission of unnecessary radiation noise from the electronic endoscope and the mixing of unnecessary radiation noise into the electronic endoscope are prevented. A new problem arises that cannot be reduced enough.

Further, in the case where a metal member is provided over the entire length of the inside of the electronic endoscope to shield the built-in electronic parts and the metal member is connected to the reference potential of the signal processing means, Usually, since the metal member arranged over the entire internal length is formed by connecting a plurality of metal members,
There is a drawback that the impedance between the most distal end portion and the rearmost end portion of the metal member arranged over the entire inner length becomes large, and the shield ability is lowered. That is, similarly, there is a problem in that it is not possible to sufficiently reduce the emission of unwanted radiation noise from the electronic endoscope and the mixing of unwanted radiation noise into the electronic endoscope.

The present invention has been made in view of the above circumstances, and prevents the reduction of the shielding ability due to the influence of the thickness of the shield member and the impedance, and surely reduces the emission of unwanted radiation noise and the mixing of unwanted radiation noise. It is an object of the present invention to provide an electronic endoscope device that can do the above.

[0007]

In order to achieve the above object, the invention according to claim 1 is an image pickup means using a solid-state image pickup element, and a signal transmission means for transmitting an electric signal photoelectrically converted by the solid-state image pickup element. A signal processing unit for processing an electric signal transmitted from the signal transmitting unit; and a first shield member formed of a conductive member and having at least a part of the image pickup unit and the signal transmitting unit inserted therein. A second shield member formed of a conductive member and electrically connected to the first shield member by covering at least a part of the first shield member, the first shield member, and the second shield member. And a third shield member which is electrically connected to each of the two shield members by making a surface contact with each other and is connected to the reference potential of the signal processing means.

According to a second aspect of the present invention, in the first aspect of the invention, the third shield member is a relay member for connecting to a reference potential of the signal processing means, and the third shield member is the third shield member.
It is characterized by comprising a fixing means for urging and fixing the shield member in a direction of making surface contact with the shield member.

That is, according to the first aspect of the present invention, at least a part of the image pickup means using the solid-state image pickup element and the signal transmission means for transmitting the electric signal photoelectrically converted by the solid-state image pickup element is provided with the first conductive member. Inserted in the shield member of
At least a part of the first shield member is covered with a second shield member which is a conductive member electrically connected to the first shield member. The third shield member connected to the reference potential of the signal processing means for processing the electric signal transmitted from the signal transmission means is connected to the first shield member and the second shield member.
Since they are brought into surface contact with each of the shield members and electrically connected, for example, when the wall thickness of the shield member is thinned to reduce the outer diameter of the insertion portion of the electronic endoscope or the shield member is Even when the impedance is partially increased due to the formation of a large number of metal members, the unnecessary radiation noise is suppressed while suppressing the deterioration of the shielding ability by the double shield of the first shield member and the second shield member. Is absorbed, and the unnecessary radiation noise absorbed by the shield member is surely eliminated by reducing the impedance by making the connecting portion of each shield member into surface contact.

At this time, as in the second aspect of the invention, the relay member for connecting the third shield member to the reference potential of the signal processing means is urged in the direction of coming into contact with the third shield member. It is desirable to fix it by fixing it, and to reduce the impedance of the connection portion to the reference potential to surely eliminate the unnecessary radiation noise absorbed by the first shield member and the second shield member.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show the first embodiment of the present invention.
1 is an explanatory view showing an external structure of an electronic endoscope, FIG. 2 is a sectional view showing a schematic structure of the electronic endoscope, FIG. 3 is a sectional view showing a structure of an imaging cable, and FIG. 4 is a camera. FIG. 5 is a detailed view of the control unit connecting connector, and FIG. 5 is a sectional view taken along line AA of FIG.

As shown in FIG. 1, the electronic endoscope 1 of the present embodiment serves as an elongated insertion portion 2 to be inserted into a body cavity or the like, and also serves as a grip portion on the proximal end side of the insertion portion 2. And a flexible universal cord 4 extending from the operation portion 3 to the rear side thereof. The insertion section 2 is configured to include, from the distal end side, a hard distal end portion 5 having an objective optical system and the like, a bendable bending portion 6, and a soft tube portion 7 having flexibility. Instead of the soft tube portion 7, a hard tube portion may be used.

The operation portion 3 is provided with a bending lever 8 for remotely performing a bending operation. Further, the operation section 3 is provided with a light guide fiber 12 (see FIG. 2) for transmitting illumination light and a universal cord 4 made of a flexible material and containing a signal cable for transmitting various signals. The universal cord 4 has a length that is sufficiently long with respect to the insertion portion 2, and a light guide connector 9 that can be connected to an external light source device (not shown) is connected to the end portion. The light guide connector 9 has a camera cable 10 branching from the side surface thereof, and is electrically connected to a camera control unit (hereinafter abbreviated as CCU) as a control device or a signal processing device at the terminal end of the camera cable 10. A possible camera control unit connection connector (hereinafter abbreviated as CCU connector) 11 is connected.

As shown in FIG. 2, the light guide fiber 12 inserted into the electronic endoscope 1 has its tip end side fixed to the illumination window of the tip end portion 5, and the light guide connector 9 at the proximal end portion thereof. Is connected to the light source device, the illumination light from the lamp in the light source device is supplied. The illumination light supplied from the light source device is the light guide fiber 12
The illumination light is emitted from the illumination window of the distal end portion 5 to the front to illuminate a subject such as a diseased part in the body cavity.

Further, an observation window is provided adjacent to the illumination window at the tip portion 5, and the objective lens 13 is attached to this observation window. A CCD 14 as a solid-state image pickup device is arranged at an image forming position of the objective lens 13 to constitute an image pickup means, and photoelectrically converts the formed optical image. This C
An image pickup cable 15 is connected to the CD 14, and reaches the CCU connector 11 via the insertion section 2, the operation section 3, and the universal cord 4.

The imaging cable 15 is, as shown in FIG.
A plurality of input / output signal lines 16 forming a signal transmission means for transmitting electric signals photoelectrically converted by the CCD 14 are provided in the central portion, and these input / output signal lines 16 are bundled and arranged on the outer periphery thereof. Is shielded by being covered with a metal mesh tube 17 as a shield member. Further, the metallic reticulated tube 17 is covered with an outer tube 18 made of an electrically insulating material and arranged on the outer periphery thereof. The first shield member is not limited to the metal mesh tube 17, and may be formed by spirally winding a metal anchor tape.

As shown in FIG. 2, the outer tube 18 of the imaging cable 15 is peeled off at both the front end side and the rear end side to expose the metal mesh tube 17, and the metal mesh tube 17 exposed at the tip side. Is connected to a cylindrical electric shield member 19 that shields the outer peripheral portion of the CCD 14, while the metal mesh tube 17 exposed at the rear end side is a third shield member made of a conductive member provided in the CCU connector 11. 20
Is electrically connected to. The tip side of the third shield member 20 has an insertion portion 2, an operation portion 3, a universal cord 4, a light guide connector 9, and a camera cable 10.
Inside, is electrically connected to the second shield member 21 made of a conductive member disposed outside the imaging cable 15.

The second shield member 21 is electrically and mechanically connected to a plurality of conductive members such as a metal mesh tube, a bending piece, a spiral metal tube, and a frame as an internal structure. The second shield member 21 and the electric shield member 19 electrically connected to the tip of the metal net-like tube 17 as the first shield member are electrically connected to each other. It An endoscope exterior member 22 made of an insulating member is provided outside the third shield member 20 and the second shield member 21.

On the other hand, C to which the CCU connector 11 is connected
Inside the CU 23, from the CCD 14 to the input / output signal line 16
A patient circuit 24 is provided as a signal processing means for processing a signal transmitted via the patient circuit 24, and an electrically stable reference potential (eg, ground potential) 25 of the patient circuit 24 is provided.
The third shield member 20 is electrically connected to. A board 26 having various electronic components is provided inside the third shield member 20, and the input / output signal line 16 of the imaging cable 15 is wired to the board 26.

The connection between the metal mesh tube 17 and the third shield member 20, the connection between the third shield member 20 and the second shield member 21, the reference of the third shield member 20 and the patient circuit 24. Connection with electric potential 25, electric shield member 1
The connection between 9 and the second shield member 21 is such that the surfaces of the respective members are connected so that the contact areas of the members to be connected are large and the contact force amount is large.

Here, a specific example of the method of connecting the shield members will be described with reference to FIGS. 4 and 5. The camera cable 10 connected to the tip side (left side in FIG. 4) of the CCU connector 11 includes a metal net-like tube 28 provided outside the spiral metal tube 27 and an insulating material provided outside the metal net-like tube 28. And an outer skin 29 made of a member.
Here, the spiral metal tube 27 and the metal mesh tube 28 are the above-mentioned second shield member 21 that absorbs unnecessary radiation noise.
The outer skin 29 corresponds to the endoscope exterior member 22 described above.

Further, the ends of the spiral metal pipe 27 and the metal net-like pipe 28 are fitted and sandwiched by a hollow cylindrical base 30 made of a metal member as an example of the third shield member 20. . By doing so, the spiral metal tube 27 and the metal mesh tube 28 serving as the second shield member.
And a base 3 as a third shield member for sandwiching this
0 is a connection between the surfaces of the outer surface and the inner surface of each other, and a large contact area can be secured.

Incidentally, such a joining method can be similarly realized at other portions, and for example, although not shown in FIGS. 4 and 5, the metal net-like tube 17 as the first shield member is used. Also, by using a die having a similar shape, it is possible to increase the contact area for connecting the surfaces of the outer surface and the inner surface. Furthermore, the method of connecting the shield members is not limited to this, and it is sufficient that the surfaces are connected to each other.

A part of the hollow cylindrical rear end of the base 30 is cut out to form a flat base surface 31 of the base. A substrate 32 is fixed to the base flat portion 31 with screws 34, and the ground pattern 33 of the base 32 and the base flat portion 31 are brought into contact with each other to be firmly and electrically connected. The substrate 32 is connected to a patient circuit of a CCU (not shown), and the ground pattern 33 of the substrate 32 is connected to a reference potential of the patient circuit.

That is, the substrate 32 functions as a relay member for connecting the base 30 as the third shield member to the reference potential of the patient circuit, and the screw 34 as the fixing means.
Thus, the substrate 32 is biased and fixed in a direction in which the substrate 32 comes into surface contact with the base flat portion 31, so that the base flat portion 31 of the base 30 as the third shield member and the ground pattern 33 of the substrate 32 are firmly fixed. To be in close contact.

The base 30 and the substrate 32 are housed in the CCU connector 11, and the inner peripheral surface of the CCU connector 11 is
A shield case 35 made of a conductive member is arranged. The shield case 35 and the base 30 contact each other,
It is electrically connected. An exterior member 36 made of an insulating material is provided outside the shield case 35 so as to cover the shield case 35.

In the electronic endoscope 1 having the above-mentioned configuration, unnecessary radiation noise radiated from the input / output signal line 16 of the image pickup cable 15 and unnecessary radiation noise that may be mixed in the input / output signal line 16 are introduced. First for covering the output signal line 16
It is absorbed by the metal net-like tube 17 serving as the shield member, and further reliably absorbed by the second shield member 21 provided outside the imaging cable 15.

The unwanted radiation noise absorbed by the metal net-like tube 17 and the second shield member 21 as the first shield member is reduced to the metal net-like tube 17 and the second shield member 2.
Reference potential 2 of the patient circuit 24, which is electrically connected to 1
The third shield member 20 connected to 5 ensures that the reference potential 25 disappears. In addition, the third shield member 2
The unnecessary radiation noise absorbed by 0 is also surely lost to the reference potential 25.

In this case, since the metal net-like tube 17 and the second shield member 21 have a long overall length, unwanted radiation noises absorbed by each may adversely affect each other. Since the rear end portions of the metal nets 17 are electrically connected to each other via the third shield member 20, the metal mesh tube 17 and the second shield member 21 are securely connected to each other. The unwanted radiation noises that are made to have the same electric potential and that are absorbed do not adversely affect each other.

The connection between the third shield member 20 and the second shield member 21, the connection between the second shield member 21 and the reference potential 25 of the patient circuit 24, the electric shield member 19 and the second shield member. Since the connection with 21 is such that the contact areas of the members to be connected are large and the contact force amount is large, the impedance of each connection part is small, and the unwanted radiation noise absorbed is reliably at the reference potential 25. Disappeared.

As a concrete example of the method of connecting the shield members, the spiral metal tube 27, the metal mesh tube 28, and the third shield member as the second shield member shown in FIGS. 4 and 5 are shown. The unnecessary radiation noise absorbed by the base 30, the shield case 35, etc. is surely due to the fact that each shield member is connected to the reference potential of the patient circuit of the CCU via the ground pattern 33 of the substrate 32. Disappears.

In this case as well, since the contact area between the flat base portion 31 of the base 30 and the ground pattern 33 of the substrate 32 is large and they are firmly adhered by the screw 34, the flat base portion 31 and the ground pattern 33 are connected to each other. The impedance of the connection part is extremely small, and there is an effect that the unnecessary radiation noise absorbed by each shield member is surely lost to the reference potential.

As described above, the electronic endoscope 1 according to the present embodiment is used.
Then, it is possible to reduce the emission of unwanted radiation noise and the mixing of unwanted radiation noise. Further, since the metal reticulated tube 17 and the second shield member 21 are doubly shielded, even if the metal reticulated tube 17 has a small wall thickness and the shielding ability of the metal reticulated tube 17 is reduced, It is possible to reliably reduce the emission of unwanted radiation noise and the mixing of unwanted radiation noise, and thus it is possible to reduce the outer diameter of the insertion portion 2 of the electronic endoscope 1.

Further, by forming the second shield member 21 from a large number of metal members, even if the impedance of the second shield member 21 becomes large and the shield ability is lowered,
Since the metal net-like tube 17 and the second shield member 21 are doubly shielded, it is possible to reliably reduce the emission of unwanted radiation noise and the mixing of unwanted radiation noise. Therefore, the design allowable range of the electronic endoscope is widened, and product design with a higher degree of freedom becomes possible. Furthermore, since the impedance of the connection part of each shield member is very small, unnecessary radiation noise absorbed by the shield member is more reliably eliminated,
Radiation of unwanted radiation noise and mixing of unwanted radiation noise can be reduced.

Next, a second embodiment of the present invention will be described. FIG. 6 is a sectional view showing a schematic configuration of an electronic endoscope according to the second embodiment of the present invention.

In the second mode, a large number of metal members are electrically connected,
By using a shield member that is mechanically connected, it is possible to deal with a partial increase in impedance. In the electronic endoscope 37 of the second embodiment,
The following configuration is different from the electronic endoscope 1 of the embodiment.

That is, as shown in FIG. 6, in the electronic endoscope 37 of the second embodiment, the inside of the insertion portion 38, the operation portion 39, the universal cord 40, the light guide connector 41, and the camera cable 43 is electrically conductive. A first shield member 42 made of a member is provided. First shield member 42
Is formed by electrically and mechanically connecting a plurality of conductive members such as a metal mesh tube, a bending piece, a spiral metal tube, and a frame as an internal structure. First
The shield member 42 has a rear end side electrically connected to a third shield member 45 formed of, for example, a metal mesh tube and housed in the camera cable 43, and a rear end of the shield member 42 made of a conductive member provided in the CCU connector 44. Connected. The third shield member 45 is connected to a reference potential of a patient circuit (not shown).

A second shield member 46 made of a conductive member is provided on the inner peripheral surface of the camera cable 43 so as to cover the first shield member 42. The second shield member 46 is made of, for example, a metal net-like tube, a spiral metal tube, a metal cylindrical member, or the like.
It is formed by mechanically connecting.

The tip of the second shield member 46 has a first
Is electrically connected to the shield member 42 of the second shield member 46, and the rear end portion of the second shield member 46 is connected to the third shield member 45.
Electrically connected to. In this case, the first shield member 42 and the third shield member 45 are connected, the third shield member 45 and the second shield member 46 are connected, and the third shield member 45 and the reference potential of the patient circuit are connected. The connection is such that the contact area between the members to be connected is large and the contact force amount is large. Further, the first shield member 4
2, third shield member 45, second shield member 46
An endoscope exterior member 47 made of an insulating member is provided on the outer side of the.

In the electronic endoscope 37 having the above structure, the unwanted radiation noise radiated from the signal line of the image pickup cable 15 or the unwanted radiation noise which may be mixed in the signal line is covered by the signal line. It is absorbed by the first shield member 42. In addition, in the portion of the camera cable 43, the first
Unnecessary radiation noise is absorbed by the shield member 42 and the second shield member 46 that covers the first shield member 42, and further, at the connection portion to the patient circuit, the third shield member in the CCU connector 44. At 45, unnecessary radiation noise is absorbed.

Unwanted radiation noise absorbed by the first shield member 42 and the second shield member 46, and the third shield member 45 electrically connected to the first shield member 42 and the second shield member 46. The unnecessary radiation noise absorbed by is surely eliminated to the reference potential of the patient circuit via the third shield member 45. In addition, connection between the first shield member 42 and the third shield member 45, connection between the second shield member 46 and the third shield member 45, connection between the third shield member 45 and the reference potential of the patient circuit. The connection is made so that the contact area between the members to be connected is large and the contact force amount is large, so the impedance of each connection part is small and the absorbed unwanted radiation noise is surely eliminated to the reference potential. It

In this case, the second shield member 46 has a relatively large impedance because many metal members are electrically and mechanically connected to each other. For this reason, there is a possibility that the unnecessary radiation noise absorbed by the second shield member 46 may be difficult to be transmitted to the third shield member 45. However, it is formed inside the second shield member 46 by, for example, a metal mesh tube. The first shield member 42 having a relatively small impedance that passes through the camera cable 43 is disposed, and the tip side of the second shield member 46 is electrically connected to the first shield member 42. Since the rear end side of the first shield member 42 is electrically connected to the third shield member 45, the first and second shield members 42, 46.
The unnecessary radiation noise absorbed by the third shield member 45
Is reliably transmitted to and absorbed.

As described above, in the electronic endoscope 37 of the second embodiment, in addition to the effect similar to that of the first embodiment, a shield member formed by electrically and mechanically connecting a large number of metal members is provided. By using it, even if the impedance becomes relatively large locally, it is possible to reliably reduce the emission of unwanted radiation noise and the mixing of unwanted radiation noise.

[Additional Notes] (Additional Item 1) Imaging means using a solid-state imaging device, signal transmission means for transmitting an electrical signal photoelectrically converted by the solid-state imaging device, and electrical signal photoelectrically converted by the solid-state imaging device. Signal processing means for processing the image signal into a video signal, a first shield member formed of a conductive member and having at least a part of the image pickup means and the signal transmission means inserted therein, and a conductive member formed of the first shield member. A second shield member connecting the shield member to a reference potential of the signal processing means; and a third shield member electrically connected to each of the first shield member and the second shield member, An electronic endoscope apparatus comprising:

(Additional Item 2) In the additional item 1, the first
At least a part of the shield member is inserted into the third shield member.

(Appendix 3) Image pickup means using a solid-state image pickup device, signal transmission means for transmitting an electric signal photoelectrically converted by the solid-state image pickup device, and an electric signal photoelectrically converted by the solid-state image pickup device as a video signal. A first shield member formed of a conductive member and at least a part of the image pickup unit and the signal transmission unit; and a first shield member formed of a conductive member. A second shield member connected to the reference potential of the signal processing means; and a third shield member having the first shield member inserted therein and electrically connected to the second shield member. In the electronic endoscope device, the tip end portion of the first shield member is electrically connected to the third shield member.

(Additional Item 4) The electronic endoscope apparatus according to Additional Item 2, wherein the tip portion of the third shield member is electrically connected to the first shield member.

(Additional Item 5) The electronic endoscope apparatus according to any one of Additional Items 1 to 4, wherein the first shield member is a mesh tube made of metal.

(Additional Item 6) At least a part of the first, second, and third shield members is covered with an electrically insulating material, according to any one of Additional Items 1 to 5. Electronic endoscope device.

(Additional Item 7) The electronic endoscope apparatus according to Additional Item 6, wherein the third shield member is a metal structural member of the electronic endoscope.

[0051]

As described above, according to the present invention, it is possible to prevent the shield performance from being deteriorated due to the influence of the thickness of the shield member and the impedance of the shield member in the electronic endoscope apparatus, and to radiate and eliminate unnecessary radiation noise. Mixing of radiation noise can be reliably reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an external structure of an electronic endoscope according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a schematic configuration of the electronic endoscope.

FIG. 3 is a sectional view showing the structure of the imaging cable of the same as above.

[Fig. 4] Same as above, a detailed view of a connector for connecting a camera control unit.

5 is a sectional view taken along line AA of FIG.

FIG. 6 is a sectional view showing a schematic configuration of an electronic endoscope according to a second embodiment of the invention.

[Explanation of symbols]

1 Electronic endoscope 14 CCD (solid-state image sensor) 16 I / O signal line 17 Metal mesh tube (first shield member) 20 Third shield member 21 Second shield member 24 Patient circuit (Signal processing means) 25 Reference potential

Claims (2)

[Claims] 1. An image pickup means using a solid-state image pickup device, a signal transmission means for transmitting an electric signal photoelectrically converted by the solid-state image pickup element, and a signal processing means for processing the electric signal transmitted from the signal transmission means. A first shield member formed of a conductive member and having at least a part of the image pickup unit and the signal transmission unit inserted therein; and a first shield member formed of a conductive member and formed of at least a part of the first shield member. A second shield member that covers and is electrically connected to the first shield member; and a second shield member that is in surface contact with each of the first shield member and the second shield member and is electrically connected Along with
A third shield member connected to the reference potential of the signal processing means, and an electronic endoscope apparatus. 2. The fixing means for fixing the relay member for connecting to the reference potential of the signal processing means to the third shield member by urging the relay member in a direction of making surface contact with the third shield member. The electronic endoscope apparatus according to claim 1, further comprising: