JPH0924022A - Electronic endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope apparatus, in which the generation and entering of an unnecessary radiating noise from a drain hole of the lower part of an enclosure unit for storing a signal processing means can be satisfactorily restrained and reduced. SOLUTION: An electronic endoscope apparatus comprises an electronic endoscope 1 having a built-in image pickup element inserted in the body cavity 9, and a signal processing means to which the electronic endoscope is removably connected through connectors 24, 25, and which includes a patient circuit 30 for conducting signal processing for the image pickup element and a secondary circuit 35 insulated from the patient circuit by an isolation means 34, wherein a conductive enclosure 4 for storing the signal processing means is provided with a drain hole with dimensions smaller than the wavelength of the maximum frequency generated in the signal processing means.

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, and more particularly, to an electronic endoscope having a signal processing means connected to an electronic endoscope having a built-in image sensor and a connector having a signal transmission line. The present invention relates to an endoscope apparatus.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, it is possible to observe internal organs in the body cavity or to perform various treatments using a treatment tool inserted into a treatment tool channel as necessary. Endoscopes are widely used.

Further, various electronic endoscopes of the type in which a solid-state image pickup device such as a charge-coupled device (CCD) is provided as an image pickup means at the tip of the insertion portion and image information is taken out as a photoelectrically converted electric signal have been proposed. There is.

In the case of a medical electronic endoscope, a circuit section (patient circuit) inserted into the body of a patient and a circuit section (secondary circuit) connected to peripheral devices such as a monitor are safe. In order to secure the property, the insulation is provided by an isolation means as shown in, for example, JP-A-1-223928.

[0005] In other words, if the insulation is not provided by the isolation means, if the insulation from the GND is reduced or becomes defective due to a failure or the like, a current flows through the human body through which the endoscope is inserted, and the GND flows. There is a fear that a very dangerous situation is expected.

On the other hand, if the isolation means insulates the patient circuit from the secondary circuit, even if the above-mentioned insulation degradation or the like occurs, current flows through only one circuit side to GND. Can be secured.

That is, when the current flows only on the patient circuit side, the current is low, and the influence on the patient is small. Also, 2
When the current flows only on the next circuit side, the patient is safe because the patient circuit side is insulated.

On the other hand, in the above-mentioned electronic endoscope apparatus,
In a case unit that stores a signal processing unit including a patient circuit and a secondary circuit, the water and the like leaking into the case unit can be discharged to the lower part of the case unit.
A drainage opening (drainage hole) is provided.

[0009]

However, even in the above-mentioned isolation means, the G of the patient circuit and the secondary circuit is
Since the ND is not shared, there is a problem that a signal is easily radiated as radio waves to the outside of the device via a stray capacitance and the like, and a radio wave from the outside is mixed into the device via the stray capacitance.

That is, the electric signal used in the electronic endoscope apparatus may be radiated to other electronic equipment to cause noise to cause malfunction, and the noise radiated from the other electronic equipment may be generated. It becomes easy to mix in the electronic endoscope apparatus, for example, noise is mixed in the video signal to deteriorate the quality of the endoscopic image, or noise is mixed in the control signal, which causes malfunction.

Further, since various signals having different levels are generally handled also in the electronic endoscope apparatus, unnecessary radiation noise can be suppressed as much as possible and radiation noise can be suppressed as much as possible. It is desired to have a function.

On the other hand, it is also considered that noise may be radiated to the outside from the water drain hole provided in the lower portion of the housing of the housing unit, or noise may enter the inside of the housing through the water drain hole. To be

Recently, EMC (generally referred to as a problem of giving electromagnetic interference (EMI) and a problem of receiving electromagnetic interference (EMS)) measures have been taken sufficiently for general electric equipment. The situation is increasingly desired.

The present invention has been made in view of the above-mentioned points, and an unnecessary radiation noise is generated from a water draining hole provided in a lower portion of a casing of a casing unit for storing signal processing means and the like. It is an object of the present invention to provide an electronic endoscope device capable of sufficiently suppressing or reducing the mixing of unnecessary radiation noise.

[0015]

SUMMARY OF THE INVENTION An electronic endoscope apparatus according to the present invention is an electronic endoscope having a built-in image pickup element that can be inserted into a body cavity or the like, and the electronic endoscope is detachable via a connector. In an electronic endoscope apparatus including a patient circuit connected to perform signal processing for the image pickup device and a signal processing means having a secondary circuit insulated from the patient circuit by an isolation means, the signal processing means is housed. The conductive casing is provided with a drain hole having a size smaller than the wavelength of the highest frequency generated by the signal processing means.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. 1 to 15 relate to a first embodiment of the present invention. FIG. 1 is an overall configuration diagram showing an electronic endoscope apparatus according to the first embodiment, and FIG. FIG. 3 is a block diagram showing a signal processing system of the unit, FIGS. 3A and 3B are circuit diagrams showing an isolation circuit, FIG. 4 is a schematic diagram showing an electronic scope, and FIG. FIG. 6 is a sectional view taken along line AA in FIG. 4, FIG. 6 is a schematic sectional view showing a structure near a connector for connecting the camera control unit and the electronic endoscope, and FIG. FIG. 8 is an enlarged view of a main part showing the internal structure of the connector, and FIG. 8 is a schematic perspective view showing a connector receiver provided on the camera control unit side;
9 is a schematic perspective view of the connector receiver of FIG. 8 when viewed from the back side, FIG. 10 is an enlarged view of a main part of a part of the motherboard of the patient circuit, and FIG. FIG. 12 is a block diagram showing that both the GND of the patient circuit and the secondary circuit are connected by a capacitor, and FIG. 12 is a perspective view showing a schematic configuration of a shield case for housing a preamplifier in the camera control unit. FIG. 13 is an enlarged side view showing a part of FIG. 12 in an enlarged manner.
(B), (c), (d) is a schematic diagram showing the shape of a drain opening provided in the lower part of the camera control unit, and FIG. 15 shows a connection part between the camera control unit and a commercial power supply. It is a schematic perspective view.

As shown in FIG. 1, the electronic endoscope apparatus 1 according to the first embodiment includes an electronic scope 2 having a built-in image pickup means, and a light source apparatus 3 for supplying illumination light to the electronic scope 2. , A video processor or camera control unit (hereinafter abbreviated as CCU) 4 for performing signal processing for the electronic scope 2, and a TV monitor 5 for displaying a standard video signal signal-processed by the CCU 4.
And a keyboard 6 connected to the CCU 4 for inputting data such as comments on the endoscope image displayed on the TV monitor 5. The above CCU4
Are arranged in a conductive case.

As shown in FIGS. 1 and 4, the electronic scope 2
A wide operating section 9 is formed at the rear end (base end) of the elongated insertion section 8 having flexibility so that the universal cable 11 can be inserted into a body cavity. Have been. A light source connector 12 is attached to an end of the universal cable 11, and the connector 12 can be detachably attached to the light source device 3.

A light guide 13 for transmitting illumination light is inserted into the insertion portion 8 and the universal cable 11 and the connector 12 is attached to the light source device 3 to illuminate the illumination light of the lamp 14 in the light source device 3. Passes through the diaphragm 15, is condensed by the lens 16, and is irradiated onto the end surface of the opposing light guide 13. The illumination light transmitted by the light guide 13 is emitted forward from the other end face attached to the distal end portion 17 of the insertion section 8, and illuminates a subject such as an affected part. The illuminated subject is imaged by an objective lens 18 provided at a tip portion 17 on an image pickup surface of a CCD 19 serving as a solid-state image pickup device disposed on a focal plane thereof.

A mosaic filter 19a for color separation is attached to the image pickup surface of the CCD 19, for example, each pixel is optically color-separated, and further photoelectrically converted by the CCD 19 to be converted into an electric signal, which is converted into an electric charge. Accumulated. The CCD 19 is connected to one end of a drive signal transmission line 21 a and one end of a CCD output signal transmission line 21 b inserted through the insertion section 8 and the universal cable 11. The other ends of the transmission lines 21 a and 21 b are connected to the light source connector 12.
To the connector receiver 22 provided on the side of the connector.

A connector 24 attached to one end of a signal cable (also referred to as an EL cable) 23 which is a transmission line for transmitting a signal output from the image pickup device is detachably connected to the connector receiver 22. The connector 25 attached to the other end can be detachably attached to a signal connector receiver (also referred to as a scope connector receiver) 26 of the CCU 4.

When the connectors 24 and 25 are respectively connected, the patient circuit 3 in the CCU 4 is connected as shown in FIG.
By supplying the CCD drive signal from the CCD driver 31 constituting 0 to the CCD 19, the signal charges accumulated in the CCD 19 are read. This read C
The CD output signal is output from the preamplifier (PRA) 3 in the CCU 4.
After being amplified by 2, the signal is input to a pre-processing circuit 33 to be separated into a luminance signal and a color difference signal, and pre-processing such as γ correction and white balance is performed. It is input to a one-pixel clamp circuit 36 constituting the secondary circuit 35.

Since the signal from which the DC component has been removed by the insulating transformer 34 is input to the one-pixel clamp circuit 36, the DC component is generated by the one-pixel clamp circuit 36, and the DC component is passed through a low-pass filter (not shown) to D
After being input to the converter 37 and converted into a digital signal, it is stored in the memory 38.

The digital signal stored in the memory 38 is read out at a predetermined timing under the control of the system controller 39, converted into an analog signal by the D / A converter 41, and then a synchronizing signal (not shown). At the same time, it is output to the TV monitor 5.

The system controller 39 (hereinafter, simply abbreviated as controller) is the interface 4
3 is connected to the keyboard 6 via the keyboard 3. By operating the keyboard 6, it is possible to input a comment regarding an endoscopic image displayed on the TV monitor 5 and display the comment on the monitor screen. ing.

The controller 39 is connected to the CCD driver 31 via an insulating transformer 45 as an isolation means, and the CCD driver 31 outputs a read drive signal to the CCD 19 in response to a timing signal from the controller 39. .

The controller 39 is also connected to an operation switch 48 provided in the operation unit 9 of the electronic scope 2 via an isolation circuit 46 using a photocoupler and a control signal line 47, for example.

The operation switch 48 is formed of, for example, a freeze switch for instructing the display of a still image, and when the freeze switch is operated, a freeze instruction signal is transmitted to the controller 39. Upon detecting this instruction signal, the controller 39 outputs a write inhibit signal to the memory 38 to inhibit the data in the memory 38 from being updated. Therefore, the signal stored in the memory 38 before the write inhibit signal is repeatedly read, and a still image is displayed on the TV monitor 5.

The controller 39 also generates and controls various timing pulses, that is, the clamp operation of the one-pixel clamp circuit 36, the A / D conversion clock of the A / D converter 37, the read / write and D / A of the memory 38.
The D / A conversion clock of the converter 41 is controlled.

The patient circuit 30 and a secondary circuit 35 insulated from the patient circuit 30 by insulating transformers 34 and 45 as isolation means constitute a signal processing means.

2 and 3A, the operation switch 48 is shown.
3 shows an isolation circuit 46 connected to a freeze switch 48a. The line 47a of the control signal line 47 connected to the switch 48 is connected to a resistor R1.
Is connected to the power supply terminal Vc1 through the other line 47b.
Is connected to GND via a resistor R2, is connected to the anode of the LED 50a of the photocoupler 50, and the cathode is connected to GND of the patient circuit 30.

Further, the collector of the phototransistor 50b is connected to the power source terminal Vc2, and the emitter thereof is the resistor R3.
Is connected to the GND of the secondary circuit 35 through the controller 39 and to the controller 39.

The resistance R2 is set to a resistance value larger than that of the resistance R1, for example, and the switch 48a is turned off (O
Even in the case of FF), the lines 47a and 47b are fixed at constant potentials, respectively, to prevent radiation and mixing of noise. That is, conventionally, the resistor R2 is not provided, so that the switch 48a is turned off (O
In the case of FF), since the potential of the line 47b was floating without being determined, the line 47b had the functions of noise generation and a receiving antenna. Since the connection to GND is made via R2, when the switch 48a is off (OFF), this GND is connected.
The potential of D is maintained to prevent noise generation and reception.

On the other hand, when the switch 48a is turned on, the light emitting current is supplied to the LED 50a through the resistor R1 and the LED 50a is turned on. In this case, the lines 47a and 47b are maintained at a potential close to GND or the power supply terminal Vc1.

Instead of FIG. 3A, an isolation circuit 46 'as shown in FIG. 3B may be used.

In this circuit 46 ', the line 47a connected to one end of the switch 48a is connected to the power supply terminal Vc1 via the resistor R4 and to the base of the transistor Q1. On the other hand, the line 47b is
0 is connected to GND. The collector of the transistor Q1 is connected to the power supply terminal Vc1, the emitter is connected to GND of the patient circuit 30 via the resistor R5, and is connected to the LED 50a via the resistor R6.
Other configurations are the same as those in FIG.

Also in this FIG. 3B, the switch 48
When a is off (OFF), the potential of the line 47a is fixed to the level of the power supply terminal Vc1 by the resistor R4, and is fixed to GND when the switch 48a is turned on (ON).
It has the same function as that of FIG.

Further, as shown in FIG.
As shown in FIG. 5, the drive signal transmission line 21a, the CCD output signal transmission line 21b, and the control signal transmission line 47 inserted into the
Shielding means for shielding by 1a-1, 21b-1, and 47-1 is formed. Each shielded wire 21a-
A signal line (both a single line and a coaxial line), which is insulated and coated, is housed inside 1, 21b-1, 47-1.

Further, each shield covered wire 21a-1, 21a
b-1 and 47-1 are covered with an insulating jacket. In FIG. 5, reference numeral 51 denotes a suction tube, which can be connected to a suction unit (not shown) in the light source device 3 by connecting the connector 12 to the light source device 3.

The transmission lines 21a, 21b and 47 are individually shielded to prevent noise from mixing between the transmission lines. For example, the drive signal transmission line 21
“a” supplies a high frequency horizontal transfer drive pulse to the CCD 19. Since this pulse has a high frequency, it is easy to generate radiation noise.
When radiation noise leaks into b, the CCD output signal is generally at a very low level, so that even a slight
N will be greatly degraded. On the other hand, by shielding the drive signal transmission line 21a with the shield means as described above, deterioration of the S / N can be prevented. Also,
If radiated noise leaks into the control signal transmission line 47, erroneous control may be performed, but this can also be prevented.

The transmission lines 21a, 21b, 47 inserted through the universal cable 11 of the electronic scope 2
Is a connector receiver 22 attached to the side of the connector 12.
(Not shown). In addition, each shield-covered wire 21a-1, 21b-1, 47-1 is
The connector receiver 22 is connected at one point to a lug 52 fixed with screws for fixing an exterior frame 22a which is a frame made of a conductive member such as a metal.

Further, as shown in FIG. 4, the connector 1
2 is provided with a connector portion 53 connected to the signal connector receiver of the light source device 3. The connector portion 53 and the connector receiver 22 are connected by a light source control signal transmission line 54. The overall shielded line of the transmission line 54 is a lug 52
Connected to a single point.

The connector portion 53 is connected to the automatic light control circuit 55 in the light source device 3 as shown in FIG. The video signal in the CCU 4 is input to the automatic light control circuit 55 via the connector 24 connected to the connector receiver 22 of the light source connector 12, the cable 23, and the like. For example, a luminance signal generated by the pre-processing circuit 33 shown in FIG. 2 is input to the automatic dimming circuit 55 via the signal line 60 and the light source control signal transmission line 54. For example, the average value of this luminance signal in one frame period Is controlled by using an error signal obtained by comparing with the set level, for example, by controlling the aperture amount of the aperture 15.

As shown in FIG. 4, inside the insertion portion 8 of the electronic scope 2, a mesh tube (also referred to as a blade) 56, which is a mesh of metal wires, is provided with a light guide 13 and transmission lines 21a, 21.
One end of a lead wire 57 is connected to the rear end (base end) of the mesh tube 56. The lead wire 57 is inserted through the universal cable 11, and the other end is connected to a pin (not shown) provided on the connector 12.

Further, as shown in FIGS. 1 and 4, the electronic scope 2 is provided with a channel 65 through which a treatment tool such as forceps and an electric knife 59 can be passed, and an insertion port 66 near the operation section 9. The treatment tool can be inserted from here.

On the other hand, the connector 12 of the electronic scope 2
The connector receiver 22 provided at the
Connector 2 having an opening which is substantially fitted to the outer frame 22a of FIG.
4, a shield gasket 61, which is an elastic conductive member, is attached to the inner periphery of the opening, so that the contact resistance between the connector receiver 22 and the outer frame 22a can be reduced. This shield gasket 61 is
The outer frame 22a is formed into a leaf spring shape by a thin copper plate or the like.
To ensure contact.

As in the case of the universal cable 11, the inside of the signal cable 23 is shielded by a shielded wire for each signal system. Similarly to the connector 24 described above, the connector 25 attached to the other end of the cable 23 has a cylindrical frame (reference numeral 81 in FIG.
There is provided a shield gasket 62 which is an elastic conductive member for ensuring contact with a). The shield gasket 62 is also formed of a thin copper plate or the like into a leaf spring shape similarly to the shield gasket 61 described above.

As shown in FIG. 6, the end portion side of the signal cable 23 passes through the ferrite core 71 housed and fixed in the connector 25, and further through the metal cylinder 72 to the pins 74, 74 ,. Each signal line is connected to the base end. Also, the respective shielded wires of the respective transmission lines 21a, 21b,... Are connected to the metal cylinder 72 as shown in FIG. The outer periphery of the metal cylinder 72 and the periphery of the ferrite core 71 are molded and fixed with a resin 75 or the like.

By providing the ferrite core 71, the noise leaking from the transmission lines 21a, 21b, ... Is absorbed and attenuated by the ferrite core 71, and the generation of unnecessary radiation noise is reduced. In this case, the ferrite core 7
When 1 is accommodated in the metal tube 72, the metal portion including the metal tube 72 transmits noise. To prevent this, the ferrite core 71 is provided separately from the outside of the metal tube 72.

In the transmission line 54 for connecting the CCU 4 and the light source device 3 and transmitting the control signal, only the light amount control signal line 54a for transmitting a signal for controlling the light amount, as shown in FIG. Is connected to the pin 74 through a small-sized ferrite core 76 inside. By passing through the ferrite core 76, the signal on the signal line 54a is generally at a low level, thereby preventing the signal from being easily affected by noise. The shield line of the signal line 54a (the signal line 54a is a coaxial line, and the shield line of the coaxial line) is connected to the shield line of the transmission line 54.

CC to which the connector 25 shown in FIG. 6 is connected
As shown in FIG. 8, the connector receiver 26 of U4 has a cylindrical metal frame 82 for reinforcement outside the cylindrical frame 81a on the front end side of the metal connector receiver main body 81, and is insulated from the connector receiver main body 81. It is provided in a double cylinder structure.

As shown in FIG. 9, the connector receiving main body 81 is electrically connected to the connector receiving fixing conductor 83 connected to the GND of the patient circuit 30 on the back side. As shown in FIG. 9, the connection lines drawn from the connector receiving body 81 to the CCU 4 side are also transmission lines 21 a,
21b,... As well as the total shielded wire 8 for each signal system.
4a, 84b, 84c,... Are shielded by shielded wires 84a, 84b, 84c,.
5 and a conductor.

That is, each shield covered wire 84i (i =
a, b, c,...) are connected at one point to the GND of the patient circuit 30 to prevent generation of unnecessary radiation noise, etc. The generation of noise and the like due to the formation of is prevented.

As shown in FIG. 8, the metal portion of the connector body 81 is connected to the chassis 86, which is the GND of the secondary circuit 35, through the capacitor C1 as an impedance element, and is electrically connected in an AC manner. Also, the outer metal frame 8
Reference numeral 2 is connected to the chassis 86 via the capacitor C2, and suppresses generation of unnecessary radiation noise when the metal frame 82 functions as an antenna.

That is, if the capacitor C2 is not provided, the metal frame 82 is in a state of floating above the GND of the secondary circuit 35, unnecessary radio waves are easily radiated from the metal frame 82, and noise enters. Although it becomes easier, by connecting the metal frame 82 to the chassis 86 via the capacitor C2, it is possible to keep the GND of the secondary circuit 35 and low impedance in terms of alternating current, and unnecessary waves are sent to the chassis 86 side. Therefore, the level of unnecessary radiation noise is reduced.

The capacitors C1 and C2 are, for example, 4k
Withstand voltage of V or more, for example, the capacity is 680 to 1
A 000 pF capacitor is used. This satisfies the condition that insulation failure does not occur even when a high voltage is applied to the GND of the patient circuit 30 and the GND of the secondary circuit 35.

Further, as shown in FIG. 8 (or FIG. 1),
In the connector receiver 26 as well, the occurrence of noise and the like is reduced through the ferrite core 87 as in the case of the connector 25 (not shown in FIG. 7). The ferrite core 87 is effective in removing noise that enters in the common mode, and the capacitor C1 helps the operation of the ferrite core 87.

As shown in FIGS. 1 and 10, the CCD output signal transmission line 21b is designed to prevent noise generation and mixing through the ferrite core 88 and input the CCD output signal to the preamplifier 32. Since a weak CCD output signal is input to the preamplifier 32, unlike the other components of the patient circuit 30, the shield case 3
It is housed in 2a so as to minimize the entry of noise.

As shown in FIG. 10, the entire drive signal transmission line 21a of the CCD drive system, which is connected to the connector receiver of the mother board 89 of the patient circuit 30 through the ferrite core 87, is shielded by winding a copper tape 90 around it. The copper tape 90 is connected to the GND of the patient circuit 30 by the lead wire 90a to prevent noise and the like. That is, since the signal lines connected to the connector receiver and the like are separated from each other on the end side, the shield becomes insufficient, and noise is easily emitted from the end side to the surroundings. Thus, by providing the copper tape 90 and the lead wire 90a as the shielding means, generation of noise and the like are suppressed.

The control signal transmission line 47 also passes through the ferrite core 91, and the connector 92 attached to the end thereof is connected to the connector receiver of the mother board 89. On the motherboard 89 near the connector receiver,
Bypass capacitor C3 allows GND of patient circuit 30
(FIG. 3A also shows a signal line 47).
For b, it is shown that it is connected to GND via the capacitor C3. ).

As described above, since the horizontal transfer clocks are transmitted to the electronic scope 2 for driving the CCD, for example, these clocks are likely to be mixed into the control signal transmission line 47 as noises. Noise is likely to be emitted to the outside through the transmission line 47. Therefore, the transmission line 47 is connected to GND via the capacitor C3. Therefore,
This has a great effect on reducing radiation noise.
As the capacitor C3, a ceramic or tantalum capacitor having a capacitance of, for example, 0.1 μF can be used.

The CCD driving line of the substrate (denoted by reference numeral 31a in FIG. 1) which constitutes the CCD driver 31 in the patient circuit 30 suppresses the generation of noise in the surroundings through a lead ferrite (not shown). are doing.

As shown in FIG. 1, FIG. 2 or FIG. 11, the GND of the patient circuit 30 and the GND of the secondary circuit 35 are AC-connected by an impedance element by a capacitor C4. That is, the patient circuit 30 is connected to the chassis 86 serving as GND via the capacitor C4 as an impedance element.
The patient circuit 30 and the GND of the secondary circuit 35 are conducted in an alternating manner.

The capacitor C4 has a withstand voltage of, for example, 4 kV. The capacitor C4 reduces the impedance between the GND of the patient circuit 30 and the secondary circuit 35 at a particularly high frequency, and has a function close to that of a common GND by directly connecting both GNDs in a high frequency band. You can

Therefore, especially in the high frequency band,
Patient circuit 30 or secondary circuit 3 via small stray capacitance
Although the high-frequency signal treated in 5 is easily radiated to the outside,
By providing this capacitor C4, both circuits 30,
Since each of the 35 GNDs is connected in an AC manner, most of the current that becomes radiation when not connected can be reduced to GND. For this reason,
It is possible to greatly reduce the unnecessary radio waves from being emitted and emitted to other circuit portions and the outside.

Further, although high frequency noise is easily intruded from the outside through the stray capacitance, the impedance with GND in the invaded portion can be lowered equivalently, and most of the noise can be reduced to GND, and the signal system It is possible to reduce the rate of mixing with the.

It should be noted that if the capacitance of the capacitor C4 is large, it is effective as a countermeasure against EMC (generally refers to the problem of giving electromagnetic interference (EMI) and the problem of receiving electromagnetic interference (EMS)), but increases the leakage current. Since this is also the case, it is sufficient to set an appropriate capacitance according to the actual environment of the circuit system and the like.

On the other hand, as shown in FIG. 1, noise is also passed through the ferrite core 95 through the flat cable 94 for connecting the secondary circuit 35 with the mother board 93 mainly including the CPU and the like which constitutes the controller 39 (see FIG. 2). We are taking measures. The flat cable 97 connected to the front panel 96 of the motherboard 93 also reduces noise through a ferrite core 98.

The ferrite core 102 also reduces noise in the cable 101 connected to the connector receiver 100 to which the connector to which the cable 99 of the TV monitor 5 is attached is connected.

The mother board 93 shown in FIG. 1 is shielded by shield cases 105 and 106 as shown in FIG. In other words, the component surface on which the components of the motherboard 93 are mounted is the shield case 105.
, And the back surface is covered with a shield case 106.

The shield cases 105, 106 have mounting pieces 105a, ..., 106a ,.
Are provided, and the mounting pieces 105a,.
are provided with holes at positions facing each other, and the motherboard 93 is fixed by screws 107,... and nuts 108,.

At this time, the shield cases 105 and 106
, 106a,... Are fixed to the motherboard 93 with screws 107,.
, 106a,... And the motherboard 93, between the conductive and rubber-like elastic gasket member 10
9 are interposed and fixed.

By thus interposing the gasket member 109, even if the adjacent screws 107 are fixed at positions separated from each other, even if the mounting piece 105a and the mother board 93 are fixed without being in close contact with each other. Since it is possible to prevent a gap from being generated due to the pressure deformation of the gasket member 109, it is possible to reliably shield the motherboard 93.

Further, the attachment pieces 105a and 106a are long provided with a small number of portions interrupted around the openings of the shield cases 105 and 106. The GND land 111 is formed as long as possible on the motherboard 93 at a position facing the mounting pieces 105a and 106a. As a result, as shown in FIG. 13, the mounting portion between the shield cases 105 and 106 and the motherboard 93 is, for example, a mounting piece 105 of the shield case 105.
a, the gasket member 109, the GND land 111 formed on the motherboard 93, and the motherboard 93 are stacked. Therefore, the shield cases 105, 10
Both surfaces of the motherboard 6 and the motherboard 93 are reliably shielded with a small gap. Therefore, emission of noise to the outside and intrusion of noise from the outside can be minimized.

On the other hand, in the electronic endoscope apparatus of the first embodiment shown in FIG. 1, the CCU 4 (which is disposed in the conductive casing as described above) has its lower portion. Further, a drainage opening (drainage hole) is provided (not shown) so that water and the like that have leaked into the housing of the CCU 4 can be drained.

In the prior art, the radiation of noise from the drain hole was not sufficiently suppressed, but in the first embodiment of the present invention, this drain hole is used. , And the shape shown in FIG. 14, respectively, makes it possible to retain the water draining function and suppress the noise radiation.

That is, FIG. 14A exemplifies a metal wire woven into a mesh shape. By setting the size of the mesh 151 in this case to be smaller than the wavelength of the highest frequency handled in the CCU 4,
The noise radiated from inside U4 can be sufficiently suppressed.

Further, FIG. 14B shows an example in which a large number of small holes are provided. The size of the small holes 152 in this case is set similarly to the mesh 151 described above.

Further, FIG. 14C illustrates a case where the small hole 152 of FIG. 14B is an oval small hole 153. Also in this case, the size of the small hole 153 is set similarly to the mesh 151 described above.

Further, FIG. 14 (d) exemplifies a hole having a rounded corner. In this case, noise emission can be reduced as compared to the conventional case where the corners are not rounded and have rectangular openings.

Next, FIG. 15 shows a connecting portion between the CCU 4 and the commercial power source. As shown in FIG. 15, for example, the plug 13 of the commercial power supply cable 131 of the CCU 4
2 from the inlet 133 to which the cable 131 is connected.
Power supply lines 134 and 1 connected to the power supply line and the GND line
34 and the GND line 135 are drawn into the housing and connected. In this case, the GND line 135 is wound around the ferrite core 136 several times, then connected to the chassis 86 inside the housing, and externally connected via the GND line 135 to the CCU.
4 is suppressed.

In the electronic endoscope apparatus 1 of the first embodiment configured as described above, the electronic scope 2 is used by being inserted into the body cavity.
A patient circuit 30 connected to the CCD 19 in the inside, and a secondary circuit 3 for performing signal processing for outputting a video signal to the TV monitor 5
5 is insulated to ensure safety as in the conventional case.

In this case, the secondary circuit 35 can have a large shield function by being connected to the ground, but the GND of the patient circuit 30 is the same as the GND of the secondary circuit 35.
In the prior art, the shield function was not sufficient because it could not be conducted.
As described above, since various radiation noise reducing means are provided, noise radiated to the outside of the device can be reduced efficiently. Further, intrusion of noise from an external device can be sufficiently reduced.

Then, even in the electronic endoscope apparatus 1,
Since the shielding is performed between different signal systems, the function of each signal processing system inside the device 1 can be sufficiently exhibited, and signal processing with good S / N can be performed.

Further, at the connecting portion between the connector 24 and the connector receiving portion 22 and at the connecting portion between the connector 25 and the connector receiving portion 26, the connector receiving portions 22 and 2 are respectively provided.
6 are provided with shielding gaskets 61 and 62,
Since the frame (cylindrical frame 81a) made of a conductive member and the conductive portion (chassis 86) which is the reference potential of the patient circuit are connected via the shield gasket 62, noise leaking to the outside or noise entering from the outside is reduced. It can be reduced.

Further, the connector 25 and the connector receiver 26
Since the cylindrical frame 81a is connected to the GND of the patient circuit 30, the capacity at this portion can be increased. That is, since this circuit portion is floating, the ground level is stable, and a circuit resistant to noise can be obtained.

FIG. 16 is a block diagram showing the main parts of an electronic endoscope apparatus according to the second embodiment of the present invention. Also, FIG.
FIG. 7 is a circuit diagram of a main part showing a state where a connector is not connected to a camera control unit of the electronic endoscope apparatus.

The second embodiment has an electric knife device 202 added to the first embodiment described above, and basically has the same configuration. Therefore, here, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 16, an electric knife 59 is inserted into the channel of the electronic scope 2 of the electronic endoscope apparatus 201.
Is connected to the A terminal of the electric scalpel device 202 via the.

The connector 12 of the electronic scope 2 is
A cable 205 is connected to a connector 204 connected to the light source device 3 and to a terminal provided on a side portion of the connector 12, and is connected to the CCU 4 ′ via the cable 205. The CCU 4 ′ is provided with a connector receiver 207 to which a connector 206 attached to the other end of the cable 205 can be attached.

The connector receiver 207 is used for the switch 20.
8 is connected to the common contact c, and the contact a is connected to GND of the patient circuit 30. Also, this switch 2
The switching contact piece 08 is normally urged by a spring 209 so as to be turned on (ON) with the contact point a as shown in FIG.

On the other hand, the pin 212 of the connector 211 is C
When the pin 212 is mounted on the CU 4 ′, the pin 212 presses the switching contact piece, whereby the contact a is turned off and the tip of the pin 212 is connected to the contact c. It comes into contact and is in a connected state.

The connector 211 is connected to the S terminal of the electric knife device 202 by the connector 214 at the other end of the cable 213. This S terminal is connected to one end of a transformer 215 via a capacitor.
The other end of 5 is connected to the A terminal via a capacitor.

The primary side of the transformer 215 is connected to the high frequency output circuit 216, and the high frequency output from the high frequency output circuit 216 is supplied to the secondary side via the transformer 215. ing.

The P terminal of the electric knife device 202 is
It is connected via a conducting wire 217 to a plate 219 which comes into contact with the patient's 218 body surface and the like in a wide interview.

On the other hand, the electrode inserted through the sheath 221 of the electric scalpel 59 projects from the opening at the tip of the sheath 221, and the loop 222 can be hooked on the polyp 223 or the like.

Then, by turning on the foot switch 224 connected to the electrosurgical knife device 202, a high frequency is output from the high frequency output circuit 216 under the control of the control circuit 225 connected to the foot switch 224. It

The control circuit 225 has a P terminal and an A terminal.
Current transformer 226 that detects the current flowing through the terminals
When the level ratio IP / IA is equal to or higher than a set value, the high-frequency current flowing through the terminal A is detected. Out of the IA, a “constant percentage” or more is returned to the P terminal via the plate 219, which means that the amount of current flowing outside this path is small. Therefore, it can be regarded as a normal use state.

That is, as shown in FIG. 16, when a high-frequency current is passed from the electric knife 59 to the patient 218 side through the A terminal, the floating capacity with the blade 56 as a conductive member around the electric knife 59 causes a certain amount of floating capacitance. Is the blade 56, S
Leakage current may flow through the terminals. At this time, in consideration of the magnitude of the leakage current due to the stray capacitance, a value at which the current IP becomes smaller than the current IA by the amount of the leakage current is checked in advance, and the value of the level ratio is set. By comparing the set value with the level ratio detected during actual use, it can be determined whether or not the device is in a normal use state. When the value is equal to or less than the set value, a warning can be issued by a warning device 228 such as a buzzer.

Further, the connector 214 is provided with a pin 231 for detecting whether or not the connector 214 is connected to the electric knife device 202. That is, when the connector 214 is connected to the electric scalpel device 202, the pin 231 makes the switching contact piece 233 resist the elastic force of the spring 232.
Is pressed to turn on the contacts a and b, and the control circuit 225 detects that the contacts a and b are conducted. In this state, when the foot switch 224 is turned on (ON), the control circuit 225 causes the high frequency output circuit 216 to output a high frequency.

In the second embodiment, the electric knife 59 is used.
Is not performed, the connector 211 is not connected, and the switch 208 is set to the contact a and the contact c.
Are in the ON state. Therefore, the blade 56 of the electronic scope 2 is held in a state of being connected to the GND of the patient circuit 30, and this blade 56 contributes to the reduction of noise.

On the other hand, when the treatment with the electric knife 59 is performed, the connector 211 is connected, so that the pin 2
12, the switch 208 is turned off. In this case, the blade 56 can be used for detecting a leakage current when the electric knife 59 is used. Other configurations are the same as those of the first embodiment.

As described above, in the second embodiment, the same effect as that of the first embodiment can be obtained, and when the electric knife 59 is not used, the blade 56 is used. Since it is connected to the GND of the patient circuit 30, it is possible to contribute to the reduction of noise generation and the like.

When the electric knife 59 is used,
Since the blade 56 is brought into the non-conductive state from GND to detect the leakage current, the treatment with the electric knife 59 can be performed with high safety.

Note that the present invention can be similarly applied to, for example, a device in which a TV camera is mounted on a fiberscope instead of the electronic scope 2 in the above-described first and second embodiments.

[0106]

As described above, according to the present invention, unnecessary radiation noise is generated from the drain hole provided in the lower portion of the housing of the housing unit that houses the signal processing means and the unnecessary radiation. It is possible to provide an electronic endoscope apparatus capable of sufficiently suppressing or reducing the mixing of noise.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a signal processing system of a camera control unit in the electronic endoscope apparatus of FIG. 1;

FIG. 3 is a circuit diagram showing an isolation circuit in the electronic endoscope apparatus of FIG.

FIG. 4 is a schematic configuration diagram showing an electronic scope in the electronic endoscope apparatus of FIG. 1;

FIG. 5 is a sectional view taken along the line AA in FIG. 4;

FIG. 6 is a schematic side view showing a cross section of a part of a connector for connecting the camera control unit and the electronic endoscope in the electronic endoscope apparatus of FIG. 1;

FIG. 7 is an enlarged view of a main part showing the internal structure of the connector of FIG. 6;

FIG. 8 is a schematic perspective view showing a connector receiver provided on the camera control unit side in the electronic endoscope apparatus of FIG. 1;

FIG. 9 is a schematic perspective view of the connector receiver of FIG. 8 as viewed from the back side.

FIG. 10 is an enlarged view of a main part showing a part of a motherboard of a patient circuit in the electronic endoscope apparatus of FIG. 1;

11 shows a patient circuit and 2 in the electronic endoscope apparatus of FIG.
FIG. 9 is a block diagram showing that both GNDs of the next circuit are connected by a capacitor.

12 is a perspective view showing a main part of a shield case that houses a preamplifier in a camera control unit in the electronic endoscope apparatus of FIG.

FIG. 13 is an enlarged side view showing a part of the shield case of FIG. 12 in an enlarged manner;

FIG. 14 is a schematic diagram showing the shape of a drainage opening provided below the camera control unit in the electronic endoscope apparatus of FIG. 1;

FIG. 15 is a schematic perspective view showing a connection portion between a camera control unit and a commercial power supply in the electronic endoscope apparatus of FIG. 1;

FIG. 16 is a main part configuration diagram of a main part of an electronic endoscope apparatus according to a second embodiment of the present invention.

FIG. 17 is a circuit diagram of a main part showing a state where a connector is not connected to a camera control unit in the electronic endoscope apparatus of FIG. 16;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic endoscope 2 ... Electronic scope 3 ... Light source device 4 ... Camera control unit (CCU, housing) 5 ... TV monitor 6 ... Keyboard 19 ... Solid-state imaging device (CCD) 22, 26 ... Connector receiving 23 ... Signal Cable (EL cable, transmission line) 24, 25 ... Connector 30 ... Patient circuit (signal processing means) 34, 45 ... Insulation transformer (isolation means) 35 ... Secondary circuit (signal processing means) C1, C2, C3, C4 ... Capacitor (impedance element)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masahito Goto 2-43-2, Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Riki Hirai 2-43-2, Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An electronic endoscope including an image pickup element that can be inserted into a body cavity and the like, and a patient circuit to which the electronic endoscope is detachably connected via a connector and which performs signal processing for the image pickup element. In an electronic endoscope apparatus provided with a signal processing means having a secondary circuit insulated from the patient circuit by an isolation means, a signal is generated by the signal processing means in a conductive housing for accommodating the signal processing means. An electronic endoscope apparatus characterized in that a drain hole having a size smaller than the wavelength of the highest frequency is provided.