JPH06269408A - Electronic endoscope - Google Patents

Abstract

PURPOSE:To reinforce insulated pressure resistance between an outer cylinder and an inner cylinder, where an electric member is arranged, and to reduce a diameter. CONSTITUTION:A first insulating member 30 at a dielectric constant epsilon1 and a second insulating member 31 at a dielectric constant epsilon2 are concentrically laminated and arranged between an internal shield cylinder 17 arranged so as to surround the electric parts including a CCD 15 arranged at the head part of the electronic endoscope and an outer cylinder 12 arranged at the outer periphery of the endoscope. Thus, even when the same electric charge is impressed, the burden of pressure resistance is more distributed and the insulated pressure resistance is more reinforced in comparison with the conventional case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating structure of an electronic endoscope which has a solid-state image pickup element at its tip and is inserted into an object to be observed.

[0002]

2. Description of the Related Art A solid-state image sensor as an image sensor,
That is, an electronic endoscope device using a CCD (Charge Coupled Device) is well known, and according to this electronic endoscope device,
A color image can be displayed on a monitor or the like inside the body to be observed such as inside a body cavity. In this electronic endoscope apparatus, a CCD or other electric (electronic) component is provided at the tip of an electronic endoscope as a scope that is inserted into a body cavity or the like, and by electrically driving the CCD, a CCD image pickup surface is obtained. The image connected to is electrically taken out as an image signal, and an image is formed by processing this image signal.

By the way, in such an electronic endoscope, the CCD and other electric parts are provided at the tip portion as described above, so that insulation measures are taken against an observed object such as a human body. FIG. 4 shows a cross-sectional structure of a tip portion of a conventional electronic endoscope. In FIG. 4, the tip portion is made of a metal screw tube, and an outer cylinder 1 is made of an insulating material. The outer cylinder 1 is also covered with the, and also functions as an electrical shield member. In this outer cylinder 1, a CCD 4 is arranged in a state of being housed in a cylindrical shield cylinder 3,
D4 is attached to the circuit board 5 and its CCD
An image is optically formed on the imaging surface via the prism 6. Further, inside the outer cylinder 1, there are arranged light guides 7A, 7B for guiding the irradiation light to the distal end portion, a treatment instrument insertion channel 8 for guiding a treatment instrument such as forceps, and the like. When an electric knife or the like is used, it can be composed of a shield member.

An insulating material 9 made of resin is filled in the gaps between the outer cylinder 1, the shield cylinder 3, the light guides 7A and 7B, and the treatment instrument insertion channel 8. According to such a configuration, noise is prevented from being mixed in the video signal obtained by the CCD 4 by the outer cylinder 1, the shield member 3, the treatment instrument insertion channel 8 and the like, and the outer cover 2 and the insulating material 9 are present. Maintains a predetermined dielectric strength,
This ensures safety for patients and others.

[0005]

In the conventional electronic endoscope as described above, there is a demand for enhancing the insulation breakdown voltage and enhancing the insulation effect to reduce the diameter of the electronic endoscope. That is, between the outer cylinder 1 and the shield cylinder 3 accommodating, for example, the CCD 4, a predetermined length is set in consideration of the dielectric constant of the insulating material 9 in order to maintain a predetermined dielectric strength voltage. However, since there is a limit to the selection of the dielectric constant of the insulating material 9 itself, it is difficult to shorten the distance between the outer cylinder 1 and the shield inner cylinder 3, and the diameter cannot be reduced. .

The present invention has been made in view of the above problems, and an object thereof is to enhance the dielectric strength voltage between the outer cylinder and the inner cylinder in which the electric member is arranged, and to reduce the diameter. It is to provide an electronic endoscope.

[0007]

In order to achieve the above-mentioned object, the present invention provides an electronic endoscope having a solid-state image sensor arranged at its distal end so as to enclose at least an electric component including the solid-state image sensor. It is characterized in that a plurality of insulating materials having different permittivities are concentrically laminated between the internal electric shield member and the external electric shield member arranged on the outer circumference of the endoscope.

[0008]

According to the above structure, when an insulating material in which a plurality of materials having different dielectric constants are laminated and an insulating material having the same dielectric constant are compared with each other in the same thickness, different dielectric constant members are given when the same charge is applied. The combined electric field strength of the electric field generated by the combination is suppressed. Therefore, the insulating material between the external electrical shield member and the internal electrical shield member can be thinned.

[0009]

1 shows the configuration of an electronic endoscope apparatus according to an embodiment. In FIG. 1, the electronic endoscope apparatus is an electronic endoscope 10 as a scope and an external processor unit 11 in FIG.
In this electronic endoscope 10, an outer jacket 13 (external electrical shield member) made of a metal screw tube is covered with an outer jacket 13. Inside the electronic endoscope 10, the prism 1
4, an electric shield inner cylinder 17 accommodating the CCD 15, the circuit board 16 and the like is arranged, and the inside of the shield inner cylinder 17 is filled with a filling material 18. The prism 1
An optical system member 19 guides an image of the inside of the observed body to 4, and the observed body image is formed on the imaging surface of the CCD 15. Further, electronic parts (not shown) are arranged on the circuit board 16, and the circuit board 16 is connected with a transmission line 20 for transmitting a signal for driving the CCD 15 and a video signal output from the CCD 15. Reference numeral 21 in the figure is a light guide.

On the other hand, the inside of the external processor unit 11 has a housing 2
An image signal processing circuit 23, which has 2 and is connected to the transmission line 20 is provided in the housing 22, and the image signal processing circuit 23 performs image processing such as white balance and gamma correction. A plug 25 is attached to the image signal processing circuit 23 via a power transformer 24, and a monitor 27 is connected via an insulating transformer 26. The transformers 24 and 26 have a role of maintaining an electrical insulation state, whereby the image signal processing circuit 23 has a predetermined withstand voltage against the AC 100V power source connected via the plug 25 or the monitor 27. Is secured.

In the apparatus having such a configuration, the image signal processing circuit 23 connected via the power transformer 24 and the insulating transformer 26 and the AC 100V power source, or the monitor 27.
The A + B route connecting the CCD 15 and the outer cylinder 12 is added to the A route between and to maintain a withstand voltage (insulation voltage test voltage) of, for example, 4 kV, and also to the case 22 of the external processor device 11. A C + D route in which the D route connecting the transmission line 20 and the outer cylinder 12 of the electronic endoscope 10 is added to the C route connecting the transmission line 20 must also maintain the withstand voltage of 4 kV. Therefore, the outer cylinder 12
The insulation between the inner cylinder 17 and the inner cylinder 17 has an important meaning, and it is necessary to provide a sufficient withstand voltage by this insulation.

Therefore, in the embodiment, as shown in the drawing, the outer cylinder 12
The first insulating material 3 having a dielectric constant ε1 between the inner cylinder 17 and the inner cylinder 17.
The second insulating material 31 composed of 0 and the dielectric constant ε 2 is laminated and arranged,
The dielectric constant is set to ε1> ε2. FIG. 2 shows the positional relationship between the outer cylinder 12 in which the insulators 30 and 31 are arranged and the inner cylinder 17 when the inner cylinder 17 is closest to the outer cylinder 12 (G interval in FIG. 1). As shown, the first insulating material 30 having a dielectric constant ε1 is formed from the outer peripheral radius a to the radius b of the inner cylinder 17, and the dielectric constant ε2 is formed from the radius b to the inner peripheral radius c of the outer cylinder 12. The second insulating material 31 is formed. And
The dielectric constants ε 1 and ε 2 are actually the values of the withstand voltage test, 4
It is set to a value that can maintain kV.

With such a structure, a charge + Q is applied to the outer surface of the inner cylinder 17, a charge -Q is applied to the inner surface of the outer cylinder 12, the electric flux density at a point of radius r from the center O is D, and the first insulating material. The internal electric field of 30 is E1, the internal electric field of the second insulating material 31 is E2, and the outer cylinder 12
When the potential difference V between the inner cylinder 17 and the inner cylinder 17 is V, the following equation is established.

[0014]

[Equation 1] E1 = K · V / ε1 · r [V / m], E2 = K · V / ε2 · r [V / m] where K = 1 / [(1 / ε1) log (b / a) ＋ (1 / ε2) lo
g (c / b)].

FIG. 3 shows the electric field strength [electric field strength (vertical axis) with respect to radius r (horizontal axis)] of the insulating material portion in the embodiment, and one kind of insulating material 9 is used as in the conventional case. If it is, the electric field strength of the curve 100 is obtained, whereas in the case of the embodiment, the curve 200 (first insulating material 30) and the curve 201 are obtained.
The electric field strength is represented by (second insulating material 31). According to this, the electric field strength at the radius r = a (the part to which the highest voltage is applied) is obtained by using two kinds of insulating materials (30, 31) as compared with the case of using one kind of insulating material (Ep). The example (Eq) becomes smaller. This is because the breakdown voltage burden is dispersed, and therefore even if the same charge is applied, the electric field strength is lower in the embodiment, and the dielectric breakdown is less likely to occur.

In the above description, the interval of radius c-a in FIG. 2 corresponds to the shortest interval G between the outer cylinder 12 and the inner cylinder 17 of FIG. It suffices to determine the dielectric constants ε1 and ε2 in consideration of the above, and it is possible to obtain a withstand voltage higher than the withstand voltage in the other portions. Further, in the description of FIG. 2, it is assumed that the outer cylinder 12 and the inner cylinder 17 are infinitely long, but the actual electronic endoscope 10 has a length of 1 m or more, which is a sufficiently large value as compared with the distance G. Therefore, the configuration of the embodiment can be considered in the same way as when the outer cylinder 12 and the inner cylinder 17 have infinite length.

Further, in the above-mentioned embodiment, 2 having different dielectric constants are used.
Although the types of the first insulating material 30 and the second insulating material 31 are used, this insulating material may be three types, four types, or the like having different dielectric constants, which further enhances the withstand voltage. Will be.

Further, in the above-described embodiment, an example in which it is applied to the insulating material between the inner cylinder 17 having the CCD 15 and the outer cylinder 12 is shown, but between the inner cylinder and the outer cylinder 12 for accommodating other electric parts. The present invention can be applied to an insulating material between the treatment instrument insertion channel 8 and the outer cylinder 1 shown in FIG. 4, for example.

[0019]

As described above, according to the present invention,
A plurality of insulating materials having different dielectric constants are concentrically formed between the internal electric shield member arranged so as to enclose the solid-state image sensor and other electric parts and the external electric shield member arranged on the outer circumference of the endoscope. Since they are stacked on top of each other, the withstand voltage between the outer cylinder and the inner cylinder on which the electric member is arranged can be significantly enhanced. Therefore, it becomes possible to reduce the diameter of the electronic endoscope by shortening the distance between the outer cylinder and the inner cylinder.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing a structure of an insulating material arranged between an outer cylinder and an inner cylinder in the embodiment.

FIG. 3 is a diagram showing electric field characteristics generated in the insulating material of the example.

FIG. 4 is a front end cross-sectional view showing the configuration of a conventional electronic endoscope.

[Explanation of symbols]

1, 12 ... Outer cylinder (external electrical shield member), 3, 17 ... Shield inner cylinder (internal electrical shield member), 4, 15 ... CCD, 8 ... Treatment instrument insertion channel, 10 ... Electronic endoscope, 30 ... 1st insulating material, 31 ... 2nd insulating material.

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[Procedure amendment]

[Submission date] August 11, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. An electronic endoscope in which a solid-state image sensor is disposed at a tip portion, and an internal electrical shield member disposed so as to wrap at least an electric component including the solid-state image sensor, and an outer periphery of the endoscope. An electronic endoscope in which a plurality of insulating materials having different dielectric constants are concentrically laminated between the external electrical shield member and the external electrical shield member.