JP7097771B2 - Endoscope device - Google Patents

Description

The present disclosure relates to an endoscopic apparatus.

Conventionally, an endoscope device has been used to take an image of an intestinal wall in the body. The endoscope device receives from an endoscope scope having an operation unit for manipulating a flexible tube inside the body, a light source for irradiating light from the tip of the endoscope scope, and an endoscope scope. It is equipped with an endoscope processor having a processor or the like for processing the image, and both are used by connecting to each other. The image taken by the endoscope scope is converted into an electric signal, transmitted to the endoscope processor via a communication cable, and displayed on a monitor connected to the endoscope processor, for example.

The connection between the endoscope scope and the endoscope processor is made of a metal material because it needs to maintain its strength. Therefore, static electricity charged in the room or static electricity charged to the user when the endoscope scope is connected to the endoscope processor may be transferred to the connection portion and become charged. If the amount of charge in the connection portion becomes large, the signal cable passing through the connection portion may be discharged, and the electronic components on the substrate connected to the signal cable may be destroyed.

In order to prevent the above problem, Patent Document 1 discloses an endoscope processor having an electrostatic induction unit including a parallel circuit of a capacitor and a resistor. In the endoscope processor described in Patent Document 1, even when static electricity enters the connection portion between the endoscope scope and the endoscope processor, electricity can be released to the capacitor side.

JP-A-2017-64040

However, in the endoscope device described in Patent Document 1, when static electricity enters the connection portion, a large current flows through the capacitor, and at that time, an induced current may be generated in the signal cable. The induced current generated in the signal cable may damage the electronic components on the board connected to the signal cable. In other words, in order to prevent the failure of the electronic circuit in the endoscope device and use it safely, it is necessary to prevent the metal connection from discharging to the signal cable and to allow a large current to flow from the connection to the ground. Need to be prevented.

The present disclosure has been made in view of the above points, and provides a technique for enhancing the safety of the endoscope device.

In order to solve the above problems, it is used by fitting a first metal connection portion of the endoscope and a second metal connection portion of the endoscope processor to connect a plurality of signal lines. In the endoscope apparatus, the second metal connection portion includes a capacitor and a current suppression resistor connected in series with each other, and a discharge resistance connected in parallel with the capacitor and the current suppression resistor. Provided is an endoscopic device that is grounded via an electrostatic induction circuit.

According to the present disclosure, the safety of the endoscope device can be enhanced.

It is a figure which shows schematically the endoscope apparatus. It is sectional drawing which shows typically the appearance that the endoscope scope and the endoscope processor are connected. It is a figure which conceptually showed the range of the resistance value in which the current suppression resistor Rr functions well. It is a figure which conceptually shows the relationship between the distance d to the signal line which is the shortest distance from the 1st metal connection part among a plurality of signal lines, and the current suppression resistance Rr. It is another figure which shows the relationship between the distance d to the signal line which is the shortest distance from the 1st metal connection part among a plurality of signal lines, and the current suppression resistance Rr. It is the figure which cut out and showed the 1st connector partially. It is a figure which shows the relationship between the 1st connector of 2nd Embodiment, and the electrostatic induction circuit.

<First Embodiment>
FIG. 1 is a diagram schematically showing an endoscope device. The endoscope device includes an endoscope scope 1 and an endoscope processor 2. As shown in FIG. 1, the endoscope scope 1 and the endoscope processor 2 are connected to each other and used to transmit and receive image signals and control signals and conduct light to be irradiated to an observation target. ..

The endoscope scope 1 includes an operation unit 11 for operating a flexible tube, and by operating the operation unit 11, for example, the tip of the tube is refracted or an affected portion provided at the tip of the tube is removed. The forceps to be treated can be manipulated. Further, an image pickup device is provided at the tip 12 of the endoscope scope 1, and for example, the inside of a patient can be imaged. The captured image is converted into an electric signal, sent to the endoscope processor 2, and displayed on the monitor D connected to the endoscope processor 2.

The endoscope scope 1 is light emitted from a light source included in a first connector 13 having a control signal cable for transmitting and receiving a control signal and an image signal cable for transmitting and receiving an image signal, and an endoscope processor 2. A second connector 14 having an optical guide for transmitting the light source is provided, and each of them is inserted into and connected to the endoscope processor 2. The endoscope scope 1 may be provided with a power supply cable in the first connector 13 to supply electric power, or may be supplied with electric power in a non-contact manner using an electromagnetic coil.

The endoscope processor 2 has an image signal processor, corrects an image signal received from the endoscope scope 1, and displays it on the monitor D. Further, as described above, the endoscope processor 2 has a light source (not shown) and irradiates light from the tip of the endoscope scope 1 through an optical guide (not shown).

FIG. 2 is a cross-sectional view schematically showing the configuration of the connection portion between the endoscope scope 1 and the endoscope processor 2 (note that the second connector 14 is omitted in FIG. 2). The endoscope scope 1 includes a substrate 15 on which an analog-digital converter, a control circuit, a timing generator, a sampling circuit, and the like (not shown) are arranged. Each electronic component included in the substrate 15 is connected to a power supply unit (not shown) provided on the substrate 16 included in the endoscope processor 2 via an image signal cable, a control signal cable, a power supply cable, and the like. To.

The electronic circuits provided on the substrate 15 on the endoscope scope 1 side and the substrate 16 on the endoscope processor 2 side are referred to as patient circuits. For safety reasons, the patient circuit is isolated from the housing of the endoscope processor 2 and grounded (PG is ground in FIG. 2). Therefore, the substrate 16 on the patient circuit side included in the endoscope processor 2 and the substrate 17 on which another image processing chip or the like (not shown) is loaded are connected via the capacitor C, and the substrate 17 is internally viewed. It is connected to the housing of the mirror processor 2 and grounded (FG is ground in FIG. 2).

Further, the first connector 13 included in the endoscope scope 1 has a cylindrical metal connector (first metal connecting portion 18) inside, and is made of a cylindrical metal included in the endoscope processor 2. It is fitted with a connector (second metal connection portion 19). At this time, the female connection pin provided by the connector on the endoscope scope 1 side (first metal connection portion 18) and the male connection pin provided by the connector on the endoscope processor 2 side (second metal connection portion 19) are connected. Be connected. The shape of the connector may be square or trapezoidal. Hereinafter, in the present specification, the connection pin and the cable connecting the boards 15 and 16 are collectively referred to as a signal line.

The second metal connection portion 19 is via an electrostatic induction circuit 20 including a capacitor C and a current suppression resistor Rr connected in series with each other and a discharge resistance Rd connected in parallel with the capacitor C and the current suppression resistor Rr. Is grounded.

As shown in FIG. 2, there is a slight gap at the connection point between the endoscope scope 1 and the endoscope processor 2, and static electricity in the room air may charge the metal connector. be. In addition, static electricity charged to the user when connecting the endoscope scope 1 and the endoscope processor 2 may be transferred to the metal connector.

The discharge resistance Rd has a relatively large resistance value, and when static electricity cumulatively enters the first metal connection portion 18 and / or the second metal connection portion 19, the charge accumulated in the capacitor C is charged. It plays a role of discharging little by little.

The current suppression resistance Rr plays a role of preventing the current flowing through the capacitor C from increasing when static electricity enters the metal connector. If the resistance value of the current suppression resistor Rr is too large, the current suppression resistor Rr is likely to be discharged from the first metal connection portion 18 to the signal line. Therefore, it is necessary to prevent the resistance value of the current suppression resistance Rr from becoming too large, and the resistance value is such that the effect of suppressing the current flowing through the capacitor C when static electricity enters the metal connector can be obtained. Must have. Therefore, the resistance value of the current suppression resistor Rr is provided with an upper limit and a lower limit.

FIG. 3 is a diagram conceptually showing a range of resistance values in which the current suppression resistor Rr functions well. In FIG. 3, the vertical axis shows the probability P that the endoscope device malfunctions or the electronic substrate is destroyed, and the horizontal axis shows the resistance value of the current suppression resistance Rr.

As shown in FIG. 3, as the resistance value of the current suppression resistance Rr increases, the probability P that the endoscope device malfunctions or the electronic substrate is destroyed decreases and reaches the minimum value, and then the current is reached. As the resistance value of the suppression resistance Rr increases, the probability P that the endoscope device malfunctions or the electronic substrate is destroyed increases. In the present disclosure, the vicinity of the value of the current suppression resistance Rr at which the probability P at which the probability P of the endoscope device malfunctions or the destruction of the electronic substrate takes a minimum value is referred to as an OK region, and the other resistance values are referred to as an NG region.

FIG. 4 is a diagram conceptually showing the relationship between the distance d to the signal line having the shortest distance from the first metal connection portion 18 among the plurality of signal lines and the current suppression resistance Rr. As described above, if the resistance value of the current suppression resistor Rr is too large, the current suppression resistor Rr is likely to be discharged from the first metal connection portion 18 to the signal line. On the other hand, if the distance d from the metal connection portion to the signal line is large, the phenomenon of discharging from the first metal connection portion 18 to the signal line is less likely to occur.

Therefore, by increasing the resistance value of the current suppression resistor Rr as the distance d increases, the influence when an induced current is generated can be reduced. In other words, the resistance value of the current suppression resistor Rr may be determined to be proportional to the distance d to the signal line having the shortest distance from the first metal connection portion 18 among the plurality of signal lines. By repeating the experiment, the present inventor found the relationship between the distance d and the resistance value in the OK region of the current suppression resistor Rr.

FIG. 5 is another diagram showing the relationship between the distance d to the signal line having the shortest distance from the first metal connection portion 18 among the plurality of signal lines and the current suppression resistance Rr. In FIG. 5, the dotted line indicates the upper limit of the current suppression resistor Rr, and the solid line indicates the lower limit of the current suppression resistor Rr. As shown in FIG. 5, the lower limit and the upper limit of the OK region of the current suppression resistance Rr are defined by the following equations 1, 2 and 3, respectively.
A ≤ Rr ≤ B ... (Equation 1)
A = 101.232 × d-101.6016 ... (Equation 2)
B = 101.232 × d + 198.3984 ... (Equation 3)

FIG. 6 is a diagram showing the first connector 13 partially cut out. FIG. 6A shows a length L (from the proximal end side of the first metal connecting portion 18 to the proximal end side of the second metal connecting portion 19) in which the signal line and the cylindrical metal connector run in parallel. (Length) is 5.5 cm, and an example of the first connector 13 designed so that the distance d to the signal line having the shortest distance from the first metal connection portion 18 among the plurality of signal lines is 1.3 mm is shown. Has been done. Further, FIG. 6B shows a cross-sectional view of the first metal connection portion 18 and the plurality of signal lines.

For example, in the case of d = 1.3 mm and L = 5.5 cm exemplified in FIG. 6 (a), if Rr ≦ 300Ω, it was possible to effectively prevent the defect or the destruction of the substrate due to static electricity. When the resistance value of the current suppression resistor Rr is selected so that the above relational expression holds, for example, electrostatic discharge or induced current is generated in the range where the length L in which the signal line and the cylindrical metal connector run in parallel is 10 cm or less. Was able to be suppressed.

In general, it is considered that the longer the length L in which the signal line and the cylindrical metal connector run in parallel, the higher the probability of discharging from the first metal connection portion 18 to the signal line. Therefore, if the resistance value of the current suppression resistance Rr is inversely proportional to the length L in which the signal line and the cylindrical metal connector run in parallel, it is considered that it becomes difficult to discharge from the first metal connection portion 18 to the signal line. Be done. That is, in the above equation 1, the resistance value of the current suppression resistor Rr may be determined as (cA) / L≤Rr≤(cB) / L (c is a constant).

<Second embodiment>
FIG. 7 is a diagram showing the relationship between the first connector 13 of the second embodiment and the electrostatic induction circuit 20. It is effective to connect the static electricity induction circuit 20 to the vicinity of a portion where static electricity enters in the second metal connection portion 19. By doing so, the path of the current flowing in the second metal connection portion 19 when the static electricity escapes to the ground is shortened, and the influence of the induced current generated in the signal line can be suppressed.

Therefore, in the second embodiment, unlike the first embodiment, the second metal connecting portions 19 are grounded via the electrostatic induction circuit 20 at four positions at equal intervals from each other. In this way, static electricity can be efficiently released. The second metal connection portion 19 may be grounded via the electrostatic induction circuit 20 at four or less or four or more positions. Further, in both the first embodiment and the second embodiment, when the electrostatic induction circuit 20 is connected to the portion of the second metal connection portion 19 located in the portion of the first connector 13 that is easily touched by the user. , The influence of the induced current generated on the signal line is increased.

1 ... Endoscope scope 2 ... Endoscope processor 11 ... Scanning unit 12 ... Tip of endoscope scope 13 ... First connector 14 ... Second connector 15, 16, 17 ... Board 18 ... First metal connection part 19 … Second metal connector 20… Electrostatic induction circuit

Claims (5)

An endoscope device used by fitting a first metal connection portion of an endoscope scope and a second metal connection portion of an endoscope processor to connect a plurality of signal lines.
The second metal connection portion is
It is grounded via an electrostatic induction circuit comprising a capacitor and a current suppression resistor connected in series with each other and a discharge resistor connected in parallel with the capacitor and the current suppression resistor.
Endoscope device. The first metal connection portion and the second metal connection portion each have a cylindrical shape.
A plurality of points of the second metal connection portion are grounded via the electrostatic induction circuit.
The endoscope device according to claim 1. The second metal connection is grounded via the electrostatic induction circuit at four positions equally spaced from each other.
The endoscope device according to claim 2. The resistance value Rr of the current suppression resistor is proportional to the distance d to the signal line having the shortest distance from the first metal connection portion among the plurality of signal lines.
The endoscope device according to claim 1. The resistance value Rr of the current suppression resistor holds the following equations 1 to 3 between the first metal connection portion of the plurality of signal lines and the distance d to the signal line having the shortest distance.
The endoscope device according to claim 1.
A ≤ Rr ≤ B ... (Equation 1)
A = 101.232 × d-101.6016 ... (Equation 2)
B = 101.232 × d + 198.3984 ... (Equation 3)

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