JPH09266886A - Noise eliminating structure for electron endoscope device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate high-frequency noises produced by the presence of connector component members that are held floating in an electron endoscope and in a main body. SOLUTION: At the connection between a connector support member 24 and a light source device 34, a connecting ring 36 placed in an electrically floating state is connected by a connecting wire 100 to a casing 41 via a capacitor C to drop noises to frame ground. For cable sheathes on the outer peripheries of signal lines 23A, 23B, double electric shields 44A, 44B are provided, and a circuit part shield 45 made of a metal is provided around a circuit substrate 25. The outside shield 44B and the circuit part shield 45 are connected to the connecting ring 36 by connecting wires 101, 102, 103 so that other noises also drop to the frame ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise removing structure in which a metallic connector component is provided in a floating state in a connector portion of an electronic endoscope apparatus for connecting an electronic endoscope to a main body side.

[0002]

2. Description of the Related Art FIG. 2 shows the overall structure of an electronic endoscope apparatus. In the figure, the tip portion 1A of the electronic endoscope 1 is shown.
Is a light guide for irradiating light into the body to be observed and a CCD (Charge Coupled Device) which is a solid-state image sensor.
Is provided, and a signal line for transmitting a control signal and a video signal (video signal) is connected to the CCD. The signal line and the light guide are guided to the connector supporting portion 3 through the cable 2.

Further, the signal line is connected to the processor device 6 from a circuit board 4 arranged in the connector supporting portion 3 via a cable 5. The circuit board 4 includes a timing generator 7A and a DSP which is a video signal processing circuit.
A (Digital Signal Processor) 7B, a CCD drive circuit and the like are provided, and the video signal from the CCD is subjected to a certain amount of image processing in the connector supporting portion 3 and transmitted to the processor device 6. Then, by outputting this video signal from the processor device 6 to a monitor or the like,
The image inside the body to be observed can be observed on a monitor or the like.

On the other hand, the light guide is provided up to the insertion portion 9 provided at the end of the connector supporting portion 3, and the insertion portion 9
Are connected to the light source device 10.

FIG. 3 shows the construction of the insertion portion 9 and the receiving portion of the light source device 10. As shown in the drawing, the insertion portion 9 is a resin case of the connector support portion 3. Body 11
The end portion of the light guide 12 is fixed to the insertion portion 9 in a protruding state.
A spring ring 13 is provided at the tip of the insertion portion 9 to prevent it from coming off.

Further, the light source device 10 is provided with a metal connecting ring 15 into which the receiving portion 14 of the inserting portion 9 is fitted, and the metal connecting ring 15 is fitted at a predetermined position on the inner surface of the connecting ring 15. By fitting the above-mentioned spring ring 13, both are firmly fixed. And this connection ring 15
Is electrically attached to the housing 17 of the light source device 10 via the insulator 16 in order to electrically separate the main body side from the connector side and maintain a withstand voltage of 4 kV or more. According to this structure, if the insertion portion 9 is inserted into the receiving portion 14 and the insertion portion 9 is fitted to the connection ring 15, the light guide 12 is formed.
The incident end of can be arranged at the emission part of the light source in the light source device, and the electronic endoscope 1 can be connected to the light source device 10.

[0007]

However, the above-mentioned electronic endoscope apparatus has a problem that high-frequency noise is radiated due to the presence of a connector component member such as the connection ring 15 which is in an electrically floating state. there were. That is, in the connector support portion 3, the clock signal supplied to each circuit such as the DSP 7B acts on the circuit component member to generate high frequency noise. In addition, the light source device 1
Noise is generated even from 0, and particularly when a xenon lamp is used as a light source, high frequency noise is generated due to a switching current and a high-voltage pulse formed by using a lighting circuit and an igniter.

Due to these high frequency noises, a noise current is induced and accumulated in the connection ring 15 which is electrically floating in the insulator 16 in the receiving portion 14. As a result, high-frequency noise is radiated by using the connection ring 15 as an antenna, and this noise may be mixed into the video signal through the signal line or the like, and may prevent formation of a good image.

The present invention has been made in view of the above problems, and an object thereof is to satisfactorily remove high frequency noise generated by the presence of a connector constituent member in a floating state on the electronic endoscope and the main body side. It is an object of the present invention to provide a noise removal structure for an electronic endoscope device that can be used.

[0010]

In order to achieve the above object, the invention according to the first aspect is for connecting a light guide and a solid-state image pickup device arranged at the tip of an electronic endoscope to the main body side. A metal provided with a connector supporting portion provided with a circuit board forming a part of the video signal processing circuit, and electrically connected to the connecting portion between the connector supporting portion and the main body in an electrically floating state. In an electronic endoscope apparatus having a connector component made of, the connector component is electrically connected to the main body side casing, and a noise current is dropped to the frame ground of the main body. Here, the above-mentioned main body indicates a processor device for image processing and a light source device. According to the second aspect of the invention, a capacitor for removing high frequency noise is provided in the main body,
The connector constituent member is connected to the main body side casing through the capacitor. According to a third aspect of the present invention, the signal line arranged in the electronic endoscope is protected by at least a double electric shield body, and the electric shield body is provided in the connector supporting portion so as to cover the circuit board. It is characterized in that the circuit portion shield body is provided and connected to the outer shield body of the cable and to the connector component member.

[0011] According to the action of the first claim, wherein,
The noise current induced in the metallic connector component is dropped to the body frame ground, and according to the second aspect of the present invention, the high frequency noise is effectively removed by the capacitor.

According to the third aspect of the invention, the high frequency noise due to the clock signal generated in the connector supporting portion can be caught by the circuit shield body and guided to the capacitor through the metal connector constituting member.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the overall configuration of an electronic endoscope apparatus according to an embodiment. In the figure, a light guide 21 for irradiating light to an object to be observed is arranged at a tip end portion 20 of the electronic endoscope, and a CCD (Charge Coupled Device) 22 which is a solid-state image pickup device detects the object to be observed. Arranged for shooting. The CCD 22 has a signal line 23A for transmitting a control signal and a video signal.
The signal line 23A and the light guide 21 are connected as a single cable and guided to the connector supporting portion 24.

The signal line 23A is connected to the circuit board 25 in the connector supporting portion 24. This circuit board 25 has a clock frequency (for example, 14.3) for other circuits.
MHz or 28.6 MHz) signal is provided to provide a timing generator 26A. Further, a DSP which is a video signal processing circuit for performing predetermined processing such as amplification, white balance processing, gamma processing, etc. on the video signal from the CCD 22 based on the clock signal.
A CCD drive circuit for supplying a drive signal to the (Digital Signal Processor) 26B and the CCD 22 is provided.

On the other hand, the circuit board 25 has a signal line 23.
The signal line 23B is led to the inside of the processor unit 28 as one cable and is connected to a memory circuit 29 for storing a video signal. The memory circuit 29 is connected to an output circuit 31 for outputting a video signal to a monitor or the like via an isolation means (pulse transformer or photo coupler) 30. By the isolation means 30, the memory circuit 29 and the output circuit 31 maintain the withstand voltage of 4 kV or more.

On the other hand, the light guide 21 is arranged up to the insertion portion 33 at the end of the connector support portion 24, and is projected and fixed from the insertion portion 33. The insertion portion 33 and the receiving portion 35 on the side of the light source device 34 have the same configuration as in FIG. 3, and by fitting the insertion portion 33 into the connection ring 36, the incident end of the light guide 21 is changed. Light source device 34
It is arranged at the light emitting portion of the halogen lamp (may be a xenon lamp) 37 therein. Further, with the above fitting, the spring ring 38 engages with the inner peripheral groove of the connection ring 36, thereby preventing the spring from coming off.

The connecting ring 36 is attached to the housing 41 of the light source device 34 via an insulator 40 and is 4 kV.
While maintaining the above withstand voltage, it is brought into an electrically floating state, and is electrically separated from the resin case body 39 on the connector supporting portion 24 side.

In the connection portion with such a light source device,
A capacitor C for electrically connecting the connection ring 36 and the housing 41 of the light source device 34 by a conductive means such as a conductive wire as shown by a connection wire 100, and for removing high frequency noise therebetween. To place. This capacitor C
As for the harmonics of the frequency (14.3 MHz) of the clock signal used in the DSP 26B and the like, the light source section (including a lighting circuit when a xenon lamp is used)
The one having a high frequency characteristic that has a low impedance at a noise frequency generated by is used. The housing 41 of the light source device 34 is grounded to the frame ground GND.

Further, in the embodiment, the signal line 2 is used.
3 and the circuit board 25 also take the following noise countermeasures. That is, a double electric shield body composed of the inner shield body 44A and the outer shield body 44B is provided in the cable jacket around the signal lines 23A and 23B. The shield bodies 44A and 44B are formed, for example, by winding a shield wire, and an insulator is arranged between them. On the other hand, in the connector supporting portion 24, a box-shaped circuit unit shield body 45 made of metal such as aluminum is arranged so as to cover the two circuit boards 25.

Then, the signal line 23A side and the signal line 2
Both outer shield bodies 44B on the 3B side are connected to each other by the connecting wire 10
1, 102 are connected to the circuit part shield body 45, and this circuit part shield body 45 is electrically connected to the connection ring 39 as shown by the connection line 103. This can be achieved, for example, by exposing the conductive member to a part of the outer circumference of the insertion portion 35. The shield body of the signal line 23 may be triple or more, and in this case, the outermost shield body is connected to the circuit portion shield body 45. The other end of the outer shield body 44B on the signal line 23B side is also grounded to the frame ground GND via the housing 46 of the processor device 28 like the connection line 104.

The embodiment has the above-mentioned configuration. In the connector supporting portion 24, by supplying the clock signal to each circuit such as the DSP 26B, the noise of the harmonic of the clock frequency is generated, and even in the light source device 34. Noise is generated by a lamp or a lighting circuit, and such noise is in an electrically floating state. Connection ring 39
Be guided to. However, the noise current generated in the connection ring 39 is transmitted through the connection line 100 to the frame ground G.
While being dropped to ND, the high frequency component is well removed by the capacitor C.

In the connector supporting portion 24, the high frequency noise generated by the clock signal is captured by the circuit portion shield body 45, and the connecting wire 103 and the connecting ring 3 are connected.
9, and is dropped to the frame ground GND of the casing 41 via the capacitor C. Furthermore, the outer shield body 4
The noise captured in 4B is also similarly dropped to the frame ground GND of the housing 41 via the connection lines 101 and 102. Of course, the above noise also flows to the frame ground GND of the processor unit 28 via the connection line 104. When using an electric knife,
The noise generated from the electric knife is also well removed.

In this way, the high frequency noise mixed in the video signal transmitted from the CCD 22 to the processor unit 28 can be reduced, and the image displayed on the monitor or the like can be improved.

In the above embodiment, only one capacitor for removing high frequency noise is provided. However, a plurality of capacitors having different high frequency characteristics may be additionally provided, which enables reliable noise removal over a wide range. Becomes Also,
The case where the light source device 34 and the processor device 28 are separately described has been described, but these devices may be configured as one main body device, and the present invention can be similarly applied to such a main body device.

Further, in the above embodiment, the case where the connection ring (36) is provided on the main body side has been described, but the case where the connection ring is provided on the connector side and other than the connection ring are electrically floating. The present invention can be applied to the constituent members of the connector.

[0026]

As described above, according to the first aspect of the present invention, the metallic connector member which is electrically floating is provided at the connector connecting portion between the electronic endoscope and the main body. Since it is electrically connected to the frame ground via the housing on the main body side, it is possible to satisfactorily remove high frequency noise generated due to the presence of the connector constituent member.

According to the second aspect of the present invention, since the connector constituent member is connected to the main body side casing via the high frequency noise removing capacitor, the high frequency noise can be removed more favorably.

According to the third aspect of the invention, the signal line arranged in the electronic endoscope is protected by at least a double electric shield, and the circuit board is covered in the connector supporting portion. Since an electric shield is provided and the outer shield of the circuit, the outer shield of the cable, and the connector component are electrically connected, high-frequency noise due to a clock signal generated in the connector support, electric knife, etc. It is possible to satisfactorily remove the noise that occurs.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of an electronic endoscope apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of an entire conventional electronic endoscope apparatus.

FIG. 3 is an explanatory view showing a connecting portion between the connector supporting portion and the light source device of FIG.

[Explanation of symbols]

3,24 ... Connector support part, 9,33 ... Insert part, 10,34 ... Light source device, 14,35 ... Receiving part, 15,36 ... Connection ring, 16,40 ... Insulator, 17,41,46 ... Case, 44A ... Inner shield body, 44B ... Outer shield body, 45 ... Circuit part shield body, 100, 101, 102, 103, 104 ... Connection line, C ... Capacitor.

Claims (3)

[Claims] 1. A connector, which is provided for connecting a light guide and a solid-state image pickup device arranged at a tip portion of an electronic endoscope to a main body side and has a built-in circuit board which forms a part of a video signal processing circuit. In an electronic endoscope apparatus having a support part, and a connector part made of metal, which is attached in an electrically floating state by an insulator, at a connection part between the connector support part and the main body side, A structure for removing noise of an electronic endoscope device, which is electrically connected to a main body side body to drop a noise current into a frame ground of the main body. 2. The electronic device according to claim 1, wherein a capacitor for removing high frequency noise is provided in the main body, and the connector constituent member is connected to the main body side casing via the capacitor. Noise removal structure of endoscope device. 3. A signal line arranged in an electronic endoscope is protected by at least a double electric shield body, and an electric shield body is provided in the connector supporting portion so as to cover the circuit board. The noise removing structure for an electronic endoscope apparatus according to claim 1 or 2, wherein the circuit shield body is connected to the outer shield body of the cable and is also connected to the connector constituent member.