JPH11221195A - Endoscopic imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent emission of unnecessary radiation noise and its inclusion. SOLUTION: Using a capacitor C4 whose dielectric strength is secured, an inductor L1 and a filter are formed between a patient circuit 30 and a secondary circuit 35, and its resonance frequency is set to a frequency exceeding the rated value, and thereby unnecessary radiation noises exceeding the rated value are removed. That is, if C4 and L1 are set to 10 pF and 0.1 μH, respectively, for example for an unnecessary radiation noise at 160 MHz, the trap frequency can be set to 160 MHz, and the unnecessary radiation noise emitted form the patient circuit 30 can be removed by releasing to the GND of the secondary circuit 35 via this filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope image pickup apparatus, and more particularly to an endoscope image pickup apparatus characterized by a part for radiating unnecessary radiation noise and mixing it.

[0002]

2. Description of the Related Art Conventionally, an endoscope capable of observing an affected part or the like in a body cavity by inserting a slender insertion portion into the body cavity, or inserting a treatment tool into a forceps channel as necessary to perform a medical treatment. Is widely used. As the endoscope, for example, a solid-state imaging device such as a CCD is built in at the distal end of the insertion section, a signal photoelectrically converted by the solid-state imaging device is transmitted through a cable, and the monitor device is connected via a signal processing unit. An electronic endoscope apparatus for displaying a color image is used.

When the electronic endoscope is for medical use, it is connected to a circuit section (patient circuit) inserted into the body of a patient and peripheral devices such as a monitor, as disclosed in Japanese Patent Application Laid-Open No. 1-223928. Isolation means for ensuring safety with the circuit section (secondary circuit) is provided and insulated.

[0004] If the patient circuit and the secondary circuit are not insulated by the isolation means, the endoscope is inserted because the insulation with the GND is reduced or becomes defective due to a failure or the like. It is anticipated that a current may flow through the human body to GND, resulting in a very dangerous situation.

For this reason, by providing the isolation means to insulate the patient circuit and the secondary circuit from each other, when the insulation degradation or insulation failure occurs as described above, the current is applied to GND only on one circuit side. The safety has improved because it is possible to flow.

However, since the GND of the patient circuit and the secondary circuit is not shared by the isolation means, the electric signal used in the electronic endoscope apparatus is not connected to the outside of the apparatus via a floating capacity or the like. In addition to the possibility that the noise radiated to the electronic device and cause malfunction may occur, and the noise radiated from other external electronic devices may enter the device through the floating capacity and reduce the image quality of the endoscope image, There is a possibility that a control signal may malfunction.

For this reason, Japanese Unexamined Patent Publication No. Hei 4-183432 discloses an arrangement in which unnecessary radiation noise reduction components such as a ferrite core are provided in a noise source to prevent radiation and mixing of unnecessary radiation noise.

[0008]

However, in order to constitute an electronic endoscope apparatus as disclosed in Japanese Patent Laid-Open No. 4-183432, it is necessary to provide unnecessary radiation noise reduction components for each line where noise is generated. Therefore, a significant increase in cost is caused, and a space for mounting the components is required, resulting in a problem that a dead space is increased. Therefore, the number of unnecessary radiation noise reduction components has to be limited.

In addition, since the electronic endoscope apparatus handles various signals having different levels from ordinary ones, unnecessary radiation noise radiated from the electronic endoscope is suppressed as much as possible, and radiation noise is mixed into the electronic endoscope. In other words, it is desired to take sufficient measures against EMC (that is, EMI, which is a problem that causes electromagnetic interference, and EMS, which is a problem that receives electromagnetic interference) for electric equipment.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an endoscope imaging apparatus capable of preventing emission and mixing of unnecessary radiation noise.

[0011]

An endoscope imaging apparatus according to the present invention is an endoscope imaging apparatus having a patient circuit section for ensuring insulation resistance with respect to a secondary circuit section to which peripheral devices are connected. A filter including a capacitor and an inductor is provided between the ground of the patient circuit and the ground of the secondary circuit.

In the endoscope imaging apparatus according to the present invention, unnecessary radiation noise is removed by the filter, so that emission and mixing of the unnecessary radiation noise can be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 relate to an embodiment of the present invention. FIG. 1 is an explanatory diagram showing a schematic configuration of an endoscope imaging apparatus, and FIG. 2 is a configuration of a signal processing system of a camera control unit in FIG. FIG. 3 is a first explanatory diagram illustrating the operation of the filter of FIG. 2, and FIG. 4 is a second explanatory diagram illustrating the operation of the filter of FIG.

As shown in FIG. 1, an endoscope imaging apparatus 1 of the present embodiment supplies an electronic endoscope 2 having a built-in image pickup device and illumination light to a distal end portion of the electronic endoscope 2. Light source device 3
A video processor or camera control unit (hereinafter abbreviated as CCU) 4 having signal processing means for an image pickup device of the electronic endoscope 2, a TV monitor 5 for displaying a video signal processed by the CCU 4, It comprises a keyboard 6 connected to the CCU 4 for inputting information, comments, etc. relating to the endoscope image on the TV monitor 5.

The electronic endoscope 2 has a built-in CCD 8 as a solid-state image pickup device at the distal end side of a flexible elongated insertion section 7, and an operation section at the rear end (base end) of the insertion section 7. 9 are formed. A universal cable 11 extends from the side of the operation unit 9, and the universal cable 11
A light source connector 12 that can be detachably attached to the light source device 3 is attached to an end of the light source device 3. The electronic endoscope 2 is provided with a channel 65 through which a treatment tool 59 such as forceps or an electric scalpel can be passed.
6 can be used to insert a treatment tool.

Further, the light source device 3 is
The light source device 3 is attached to the
The light exits from the lamp 14 inside the diaphragm device 15 and the lens 16
The illumination light condensed by passing through the light guide 13 is applied to the end face of the light guide 13.

The illumination light applied to the end face of the light guide 13 is transmitted through the light guide 13 provided in the universal cable 11 and the insertion section of the electronic endoscope 2 to illuminate the observation section. An object image of the observation unit illuminated by the illumination light is formed on an imaging surface of a CCD 8 disposed on a focal plane of the observation unit by an objective lens 18 provided at a distal end portion 17. The CCD 8 has the CC
A drive signal transmission line 21a for driving D8 and a CCD output signal transmission line 2 for transmitting a video signal photoelectrically converted by the CCD8.
1b is connected, extends through the electronic endoscope insertion section 7 and the universal cable 11, and extends to the signal connector receiver 22 provided on the side of the light source connector 12.

The signal connector receiver 22 has a signal cable connector 2 provided at one end of a signal cable 23.
4 can be detachably connected, and the CCU connector 25 provided at the other end of the signal cable 23 can be detachably attached to the CCU connector receiver 26 provided on the CCU 4. It has become. The signal connector receiver 22 provided on the light source connector 12 and the signal cable connector 24 are connected, and the CCU connector receiver 26 is connected to the CCU connector 25.
The video signal is input into the CCU 4 via the cable 23 by attaching the.

As shown in FIG. 2, when a CCD driving signal from a CCD driver 31 constituting a patient circuit 30 in the CCU 4 is supplied to the CCD 8, the signal charges stored in the CCD 8 are read. The read CCD output signal is amplified by the preamplifier 32 in the CCU 4 and then
After being input to the pre-processing circuit 33 and separated into a luminance signal and a color difference signal, or subjected to pre-processing such as γ correction or white balance, a secondary circuit 35 is formed via an insulating transformer 34 as an isolation means. The data is input to the one-pixel clamp circuit 36. This one
The pixel clamp circuit 36 is connected to the
Since the signal from which the DC component has been removed is input, the DC component is generated by the one-pixel clamp circuit 36, and is input to the A / D converter 37 via a low-pass filter (not shown), converted into a digital signal, and stored in the memory 38. It is designed to be stored.

The digital signal stored in the memory 38 is read out at a predetermined timing under the control of a system controller (hereinafter abbreviated as a controller) 39, and converted into an analog signal by a D / A converter 41. After that, it is output to the TV monitor 5.

The controller 39 is connected to the keyboard 6 via the interface 43. By operating the keyboard 6, the controller 39 converts a control operation, and displays information and comments on an endoscope image displayed on the TV monitor 5. Can be input and displayed on the monitor screen.

The controller 39 is connected to the CCD driver 31 via an insulating transformer 45, and receives a CCD signal according to a timing signal from the controller 39.
Since the driver 31 outputs a drive signal for reading to the CCD 8, the driver 31 is provided in the operation unit 9 of the electronic endoscope 2 via an isolation circuit 46 using a photocoupler and a control signal line 47, for example. When the freeze switch is operated by forming the operation switch 48 with a freeze switch for instructing display of a still image, a freeze instruction signal is transmitted to the controller 39, and the controller 39 When the freeze instruction signal is detected, a write inhibit signal is output to the memory 38 to inhibit the data in the memory 38 from being updated.

Therefore, before the write inhibit signal, the memory 3
8 will be repeatedly read out,
A still image is displayed on the TV monitor 5.

The controller 39 generates and controls various timing pulses, that is, the clamp operation of the one-pixel clamp circuit 36 and the A / D converter 37 of the A / D converter 37.
Conversion clock, read / write of memory 38 and D / A
The D / A conversion clock of the converter 41 is controlled. For example, the luminance signal generated by the pre-processing circuit 33 shown in FIG. 2 is input to the automatic dimming circuit 55 in the light source device 3 shown in FIG. 1 via the signal line 60 and the light source control signal transmission line 54. The aperture device 15 generates an error signal obtained by comparing the average value of the luminance signal in one frame period with a set level.
Automatic dimming is performed by controlling the aperture of the lens.

Since the endoscope imaging apparatus 1 shown in FIG. 1 has the patient circuit 30 insulated from the secondary circuit 35, it is very difficult to suppress unnecessary radiation noise. As shown in FIG. 3, CISPR. Pub. 11 exceeds the standard value of Class B (FIG. 3 shows a state in which the unnecessary radiation noise of 160 MHz exceeds the standard value).

Therefore, in the present embodiment, as shown in FIG. 2, an inductor L1 and a filter are formed between the patient circuit 30 and the secondary circuit 35 by using a capacitor C4 having a high withstand voltage. By setting the resonance frequency to match the frequency exceeding the standard value (in this case, 160 MHz), unnecessary radiation noise exceeding the standard value is removed.

That is, for the unnecessary radiation noise of 160 MHz shown in FIG. 3, for example, C4: 10 pF, L1: 0.1 μm
When set to H, as shown in FIG. 4, the trap frequency can be set to 160 MHz, and unnecessary radiation noise radiated from the patient circuit passes through the G filter of the secondary circuit 35 via this filter.
It can be removed by dropping to ND.

As described above, according to the present embodiment, unnecessary radiation noise of a frequency exceeding the standard value is removed by the LC filter provided between the patient circuit 30 and the secondary circuit 35. Emission and mixing of unnecessary radiation noise can be prevented.

In this embodiment, an electronic endoscope having a built-in solid-state imaging device at the tip of the insertion section has been described as an example.
Not limited to this, it goes without saying that an endoscope imaging apparatus having an external TV camera head for TV observation by connecting a TV camera to the eyepiece of the endoscope may be used.

[Supplementary Note] (Supplementary Note 1) In an endoscope imaging apparatus having a patient circuit unit that ensures insulation resistance with respect to a secondary circuit unit to which a peripheral device is connected, the ground of the patient circuit unit and the An endoscope imaging apparatus comprising: a filter configured by a capacitor and an inductor provided between a ground of a secondary circuit unit and an unnecessary radiation noise removed by the filter.

(Additional Item 2) The endoscope imaging apparatus according to Additional Item 1, wherein the filter is a resonance circuit of the capacitor and the inductor.

[0033]

As described above, according to the endoscope imaging apparatus of the present invention, since unnecessary radiation noise is removed by the filter, the radiation and mixing of the unnecessary radiation noise can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a schematic configuration of an endoscope imaging apparatus according to an embodiment of the present invention;

FIG. 2 is a block diagram illustrating a configuration of a signal processing system of the camera control unit in FIG. 1;

FIG. 3 is a first explanatory view illustrating the operation of the filter of FIG. 2;

FIG. 4 is a second explanatory diagram illustrating the operation of the filter of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope imaging device 2 ... Electronic endoscope 3 ... Light source device 4 ... CCU 5 ... TV monitor 6 ... Keyboard 7 ... Insertion part 8 ... CCD 9 ... Operation part 11 ... Universal cable 12 ... Light source connector 13 ... Light Guide 14 ... Lamp 15 ... Stopper 16 ... Lens 17 ... Tip 18 ... Objective lens 21a ... Drive signal transmission line 21b ... CCD output signal transmission line 22 ... Signal connector receiver 23 ... Signal cable 24 ... Signal cable connector 25 ... CCU connector 26 ... CCU connector receiver 30 ... Patient circuit 31 ... CCD driver 32 ... Preamplifier 33 ... Preprocessing circuit 34 ... Insulation transformer 35 ... Secondary circuit 36 ... 1 pixel clamp circuit 37 ... A / D converter 38 ... Memory 39: System controller 41: D / A converter 43: Interface 5 ... insulation transformer 46 ... isolation circuit 47 ... control signal line 48 ... operation switch 54 ... light source control signal transmission line 55 ... automatic light control circuit

Claims (1)

[Claims] 1. An endoscope imaging apparatus having a patient circuit section having insulation resistance secured to a secondary circuit section to which a peripheral device is connected, wherein a ground of the patient circuit section and a ground of the secondary circuit section. And a filter configured by a capacitor and an inductor is provided between the endoscope and the filter, and the filter removes unnecessary radiation noise.