JP2911037B2 - Endoscope imaging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging apparatus for an endoscope which is improved so as to prevent deterioration of image quality due to mixing of noise.

[Related Art] In recent years, various devices using a solid-state imaging device as observation means of an endoscope have been proposed (Japanese Patent Application Laid-Open No. 58-69508, etc.). An imaging device used for this type of endoscope includes an imaging optical system, a solid-state imaging device, a preceding circuit, a signal processing unit, and a long imaging cable. Therefore, in order to facilitate the assembly operation, a plurality of signal lines of the video transmission system and the imaging device driving system are mixed and bundled. Further, at least the drive pulse signal and the video output signal use a coaxial cable with impedance matching.

[Problems to be Solved by the Invention] By the way, the imaging cable of the endoscope is composed of a plurality of signal lines, and furthermore, the arrangement of each signal line in the imaging cable is not taken into consideration, and each line is close to each other. The high-frequency current flowing through the horizontal shift register drive pulse line and the vertical shift register drive pulse line of the image sensor drive system during operation of the endoscope is induced as high-frequency noise in the video signal output line. Therefore, there is a problem that a good image cannot be obtained. To cope with this, it is conceivable to double shield the video signal at least, but this has the disadvantage that the cable becomes thick and the diameter of the insertion portion becomes large.

The present invention has been made in view of the above problems, and prevents a high-frequency current flowing through a drive pulse line from riding as a high-frequency noise on a video signal output line without increasing the diameter of an imaging cable, thereby reducing noise. It is an object of the present invention to provide an endoscope imaging device capable of obtaining an image.

Means and Action for Solving the Problems The present invention has a solid-state imaging device as an imaging unit, and transmits a drive signal for driving the solid-state imaging device from a signal processing unit to a horizontal shift register driving pulse line. And transmitted to the solid-state imaging device via the vertical register drive pulse line, and the output signal of the solid-state imaging device is transmitted to the signal processing means via the video signal output line, within the same bundle,
In an endoscope imaging apparatus in which a horizontal shift register driving pulse line, a vertical shift register driving pulse line, a video signal output line, and other various lines are arranged, the horizontal shift register driving line and the video signal output within the same bundle. A line other than the video signal output line, the horizontal shift register drive pulse line and the vertical shift register drive pulse line is arranged between the lines and between the vertical register drive line and the video signal output line. The drive pulse line and the video signal output line are not adjacent to each other.

With this configuration, transmission and reception of electromagnetic waves between the horizontal shift register driving pulse line and the vertical shift register driving pulse line and the video signal output line are reduced, so that high-frequency noise induced on the video signal output line is reduced, and image quality is deteriorated. Is prevented.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 relate to a first embodiment of the present invention. FIG. 1 is a sectional view showing an imaging cable, and FIG. 2 is an explanatory view showing an imaging device for an endoscope.

In FIG. 2, reference numeral 1 denotes an image pickup apparatus, which is an objective lens 2, a solid-state image pickup device 3, a pre-stage circuit 4, a signal processing unit 5 as signal processing means, and a video signal output from the signal processing unit 5 on a screen. It comprises a monitor TV 6 for displaying and an imaging cable 7 for connecting the pre-stage circuit 4 and the signal processing unit 5.

The imaging cable 7 in the imaging device 1 is generated from various drive lines from the imaging device driving circuit 8 in the signal processing unit 5 and from the imaging device 3,
And a video signal output line to be transmitted to the process circuit 9. Further, a plurality of lines including the various drive lines and the video signal output lines are bundled to form a bundle of cables.

As shown in FIG. 1, the imaging cable 7 is connected to a power line 10
, A horizontal shift register driving pulse line 11, a vertical shift register driving pulse line 12, and a ground line 13.
And an unraveling prevention member covering the outside of each line to prevent the bundle of each line and the video signal output line 14 from being unraveled
15 and an intervening member 16 which is located at the center of each line and improves the fit of each line.

Here, the power supply line 10, the horizontal shift register driving pulse line 11, and the vertical shift register driving pulse line 12
The ground line 13 is a minimum line required to drive the solid-state imaging device 3, and the horizontal shift register driving pulse line 11 and the vertical shift register driving pulse line 12 therein have a frequency of several KHz or more. A high-frequency current flows. A power supply line 10 is located as another line between the video signal output line 14 and the horizontal shift register drive pulse line 11, and a power supply line 10 is located between the video signal output line 14 and the vertical shift register drive pulse line 12. The ground line 13 is located as another line. Further, each of the above-mentioned lines is constituted by a coaxial cable whose impedance is matched. In addition, power line
The line 10 and the ground line 13 may be simple lines.

In such a configuration, since the video signal output lines 12 are located apart from the horizontal shift register drive pulse line 11 and the vertical shift register drive pulse line 10 without being adjacent to each other, the horizontal shift register drive pulse lines 11 In addition, the high-frequency component of the high-frequency current flowing through the vertical shift register drive pulse line 12 does not leak and ride on the video signal output line 14 as noise, thereby preventing the image quality of the image displayed on the monitor TV 16 from deteriorating.
In addition, since noise is prevented by optimizing the arrangement of each line, it is possible to prevent the imaging cable 7 from having a large diameter by, for example, double shielding the video signal output line 14.

3 to 8 relate to a second embodiment of the present invention, FIG. 3 is an explanatory view showing an imaging device for an endoscope, FIG. 4 is an enlarged sectional view showing a distal end portion of an electronic endoscope, FIG. 5 shows A-
FIG. 6 is an explanatory view showing a coaxial cable, and FIG.
The figure is an explanatory diagram showing a simple line.

In this embodiment, the imaging apparatus of the present invention is applied to an electronic endoscope.

3, an electronic endoscope device 21 includes an endoscope 22, a light source unit 23 that supplies illumination light to the endoscope 22, and a signal processing unit that processes a video signal transmitted from the endoscope 22. 24, and a monitor TV 25 for displaying a video signal output from the signal processing unit 24 on a screen.

The endoscope 22 includes an elongated insertion portion 26, a large-diameter operation portion 27 connected to the rear end side of the insertion portion 26, and a universal cord 28 extended from the operation portion 27 to the outside. It has.

An objective lens 29, a solid-state imaging device 30, and a pre-stage circuit 31 are provided on the distal end side of the insertion portion 26, and the pre-stage circuit 31 and the signal processing unit 24 are connected by an imaging cable 32.

The imaging cable 32 transmits various drive lines for transmitting signals generated from the image sensor driving circuit 33 in the signal processing unit 24, and a video signal generated from the solid-state image sensor 30 via the pre-stage circuit 31. Video processing circuit in signal processing unit 24
And an image signal output line for transmitting the signal to the image signal output line 34, and the imaging cable 32 bundles a plurality of signal lines including the various drive lines and the image signal output line to form a bundle of cables. I have.

As shown in FIG. 4, the solid-state imaging device 30 is fixed to a metallic imaging device holder 35 via an aperture 36 with an epoxy adhesive 37. The solid-state imaging device 30 is composed of a transparent filler 42 filled between the external lead 38, the header 39, the chip 40, and the cover glass 41, and the center of the image area of the chip 40 is fitted to the lens frame of the element holder 35. It is fixed to the element holder 35 so as to substantially coincide with the center of the part 43.
Further, the lens frame fitting portion 43 is subjected to black processing for antireflection.

An IC board 44 and a through board 45 are connected to the external leads 38 of the image sensor 30 by soldering. A metal cable fixing member 46 is fixed to the rear ends of the IC board 43 and the through board 45 by soldering. Although not shown, the ground line 13 and the fixing member 46 are connected. The external leads 38 are fixed to the outer surface of the IC
Of the 32 lines, the video signal output line 14 and an internal conductor (47) of a noise cancel line described later are also connected by soldering.

On the inner surface of the IC substrate 44, an IC 48 is provided in a chip-on-board shape and sealed with a sealing resin 49. further,
A capacitor 50 is also mounted, and is coated with an insulating agent 51. A locking hole 52 is formed in the cable fixing member 46 so that positioning and holding for fixing the cable fixing member 46 to the IC board 44 and the through substrate 45 during assembly can be performed.

On the outer surface side of the through substrate 45, the external leads 38 are fixed, and the inner conductors of the horizontal shift register driving pulse line 11, the vertical shift register driving pulse line 12, and the anti-blooming gate driving pulse line of the lines of the imaging cable 32 are fixed. (47) is connected by soldering.

After the outer conductor 53 of each line of the imaging cable 32 is temporarily fixed by the wire 54 arranged along the cable fixing member 46,
The conductive fixing agent 55 electrically connects to the cable fixing member 46. External leads on the outer surface of IC board 44 and through board 45
38. The inner conductor (47) of each line is connected, and an insulating agent 56 is applied for strength reinforcement and insulation. Further, an insulating tube 57 for ensuring insulation of side through holes provided on the side surfaces of the IC substrate 44 and the through substrate 45 is provided on the outside thereof.

The internal space surrounded by the IC board 44 and the through board 45 is the IC 48
A heat-dissipating potting agent 58 having good heat-dissipating properties is filled so as not to come into contact with the image sensor 30 in order to release the heat generated in the step S1.
Here, the reason why the contact is not made to the image pickup device 30 is to prevent heat from being transmitted to the image pickup device 30 side. Further, on the cable fixing member 46 side, an IC board 44 and a through board 45,
An adhesive 59 is applied to reinforce the fixation of the cable fixing member 46.

A metallic shield frame 60 covering the entire outer periphery is conductively connected and fixed to the element holder 35 and the cable fixing member 46. The reinforcing adhesive 61 is used to reinforce the partial strength of the portion where the imaging cable 32 is divided into each line. Further, the insulating tube 62 insulates the ground line of the imaging device 30 from the scope exterior metal. The ventilation hole 63 is a ventilation hole for preventing a pressure difference between the inside and the outside of the endoscope from occurring when the endoscope 22 is subjected to gas sterilization, thereby preventing the destruction of the imaging device.

The objective lens 29 is attached by a first lens frame 64 and a second lens frame 65 and an insulating frame 66 for insulatingly connecting them. The outer periphery of the second lens frame 65 is fitted to the lens frame fitting portion 43 of the element holder 35, and after adjusting the focus, is filled with an insulating adhesive 67 and adhered and fixed.

The imaging device including the objective lens 29, the solid-state imaging device 30, the pre-stage circuit 31, and the imaging cable 32 has a seal member 68 attached thereto, is inserted into the distal end component 69, and is watertight to the endoscope distal end portion by the fixing pin 70. Fixed.

The illustrated solid-state imaging device 30 is a line transfer type monochrome CCD.
In D, a color image is obtained by a so-called frame sequential method, but it is a matter of course that a simultaneous image method in which a modike filter is arranged on the front side may be used.

As shown in FIG. 5, the imaging cable 32 of this embodiment includes a power supply line 10, a horizontal shift register driving pulse line 11, a vertical shift register driving pulse line 12, a ground line 13, an anti-blooming A driving pulse line 71, a video signal output line 14, which is a video signal transmission system, and the video signal output line
Noise cancel line 72 placed adjacent to and parallel to 14
And, insulation tape 73, overall shield 74, overall jacket
75.

The noise cancel line 72 subtracts the signal of the noise cancel line 72 from the signal of the video signal output line by utilizing that noise equivalent to the noise induced in the video signal output line 14 is also induced in the noise cancel line 72. This is a line for removing noise. Further, the plurality of lines composed of the various lines are bundled and spirally wound horizontally around the ground line 13 to form a single cable.
An overall shield 74 made of a metal conductor is wound through the metal layer, and an outermost jacket is covered with an insulating overall jacket 75.

Further, the seven lines are an anti-blooming gate drive pulse line 71, a video output line 14, a noise cancel line 72, a power supply line 10, a vertical shift register drive pulse line 12, clockwise around the ground line 13. A horizontal shift register drive pulse line 11 is provided.

By the way, the frequency of each drive pulse line is, for example, 9.5 MHz for the horizontal shift register drive pulse line 11 and 500 KHz for the vertical shift register drive pulse line 12, while 3.58 MHz for the anti-blooming gate drive pulse line 71. Although it has a high frequency, it does not operate during transmission of the video signal, and therefore has very little effect on the video signal. And the noise cancellation line as described above
The reference numeral 72 is provided adjacent to the video signal output line 14 because the noise immunity must be equal to that of the video signal output line 14.

The horizontal shift register drive pulse line 11 which is a high frequency drive pulse line is connected to the video signal output line 14.
And another line is interposed therebetween without being adjacent to the anti-blooming gate drive pulse line 71.
Similarly to the horizontal shift register driving pulse line 11, the vertical shift register driving pulse line 12, which has a high frequency, is also provided separately from the video signal output line 14 and the anti-blooming gate driving pulse line 71.

The horizontal shift register drive pulse line, the vertical shift register drive pulse line, the video signal output line, and the noise cancel line are each shielded, but each coaxial cable is used to reduce the diameter of the endoscope. Are extremely thin, and each coaxial cable is close and closely spaced over a length of 3-6 m. for that reason,
Although shielded, the video signal output line and the noise cancel line are susceptible to the horizontal and vertical shift register drive pulse lines, so the above-described measures are required.

FIG. 6 shows a horizontal shift register driving pulse line 11,
Vertical shift register drive pulse line 12, video signal output line 14, anti-blooming gate drive pulse line
71 shows an impedance-matched coaxial cable 80 used for the noise canceling line 72.

The coaxial cable 80 shown in FIG.
Inner insulation covering 81, outer conductor covering inner insulation 81
53, an external insulating coating 82 covering the external conductor 53;

FIG. 7 shows a simple line 90 used for the power supply line 10 and the ground line 13.

A simple line 90 shown in FIG. 7 includes a conductor 91 and an insulating coating 92 covering the conductor.

Further, the coaxial cable 80 and the simple wire 90 have the same diameter, and are filled in the hexagonal closest packing by these seven wires to be bundled to have the minimum diameter, thereby constituting the imaging cable 32.

FIG. 8 is a circuit diagram of the distal end portion of the endoscope 22 shown in FIG. Reference numeral 93 denotes a shield member that covers the solid-state imaging device 30 and the former-stage circuit 31, and includes terminals 10a and 11 of the solid-state imaging device 30.
a, 12a, 13a, 14a, 71a are a power supply line 10, a horizontal shift register driving pulse line 11, a vertical shift register driving pulse line 12, a ground line 13, a video signal output line 14, and an anti-blooming gate driving pulse line 71, respectively.
It corresponds to. Further, the terminals 10a, 13a, 14a and the pre-stage circuit 3
One terminal 10b, 13b, 14b is connected. The terminals 10c, 13c, 14c, and 72c of the pre-stage circuit 31 are the conductor 91 of the power line 10, the conductor 91 of the ground line 13, the internal conductor 47 of the video signal output line, and the internal conductor of the noise cancel line 72, respectively.
Connected to 47. On the other hand, the terminals 11a,
12a and 71a are the internal conductors 47 of the horizontal shift register drive pulse line 11, the vertical shift register drive pulse line 12, and the anti-blooming gate drive pulse line 71, respectively.
It is connected to the. Outer conductors 53 of various lines formed of coaxial cables are connected to inner conductors 91 of ground line 13.

The pre-stage circuit 31 outputs a signal obtained by amplifying the output signal of the terminal a to the terminal c.

According to such a configuration, the horizontal shift register driving pulse line 11 and the vertical shift register driving pulse line 12
Since the video signal output line 12 is arranged at a certain distance from the image signal, the high frequency noise of the video signal output line induced by the high frequency current flowing in the horizontal shift register driving pulse line 11 and the vertical shift register driving pulse line 12 is reduced. .

Further, since the noise cancel line 72 and the video signal output line 14 are arranged adjacent to each other, the noise induced in the noise cancel line 71 and the video signal output line 14
And the noise in the video signal output line is removed by the signal processing unit 24.

This allows the motor TV to maintain a minimum diameter bundle.
Image quality of the image displayed on the screen can be prevented.

It should be noted that the power line 10 and the video signal output line 14 can obtain the same effect even with a coaxial cable 80.

 FIG. 9 is a sectional view showing a third embodiment of the present invention.

The imaging cable 101 of the present embodiment replaces the noise canceling line 71 of the imaging cable 32 shown in FIG. 5 with an intervening member 102 for balancing at the time of bundling, and further exchanges various lines in the imaging cable 32. The arrangement has been changed.

The arrangement of various lines in the imaging cable 101 is such that a video signal output line 14, a ground line 13, an anti-blooming gate drive pulse line 71, and a horizontal shift register drive pulse line 11 are arranged clockwise around the intervening member 102. , The vertical shift register driving pulse line 12 and the power supply line 10 are arranged in this order.

In addition, insulation tape 73, total shield 74, integrated jacket
75 is the same as FIG.

According to such a configuration, the horizontal shift register driving pulse line 11 and the vertical shift register driving pulse line 12
Since the video signal output line 12 is arranged at a certain distance from the image signal output line 12, the high frequency noise of the image signal output line induced by the high frequency current flowing through the horizontal shift register driving pulse line 11 and the vertical shift register driving pulse line is reduced.

As a result, it is possible to prevent the image quality of the image displayed on the monitor TV from deteriorating.

FIG. 10 is a sectional view showing a fourth embodiment according to the present invention.

The imaging cable 103 of the present embodiment is the same as that of FIG. 9 except that the arrangement of various lines in the imaging cable 101 of FIG. 9 is changed.

The arrangement of the various lines in the imaging cable 103 is such that the intervening members 10 are arranged clockwise around the ground line 13.
2. The anti-blooming gate drive pulse line 71, the horizontal shift register drive pulse line 11, the vertical shift register drive pulse line 12, the power supply line 10, and the video output line 14 are arranged in this order.

According to such a configuration, the horizontal shift register driving pulse line 11 and the vertical shift register driving pulse line 12
Since the video signal output line 12 is arranged at a certain distance from the image signal, the same effect as in the embodiment of FIG. 3 can be obtained.

FIGS. 11 (A) and 11 (B) are cross-sectional explanatory views showing a state where an IC is mounted on an IC substrate as shown in FIG. 4 and sealed with a sealing resin.

In general, an image pickup device incorporated in an insertion section of an endoscope has a solid-state image pickup device that picks up an endoscope observation image incident from an objective lens and a video signal output from the image pickup device. An IC 112 mounted on a chip is provided. When the chip-on-board IC 112 is covered with the sealing resin 113 for the purpose of preventing physical damage and blocking moisture, a sufficient distance is required from the IC 112 to the substrate end surface 114.
When the IC is placed and the IC 112 on the substrate 111 is sealed by potting, the sealing resin 113 is diffused (as shown in FIG. 11 (A)), so that there is sufficient space between the IC 112 and the sealing resin 113 surface. Thickness cannot be maintained, and the reliability as IC protection is poor.

Therefore, when the sealing resin 113 is filled up to the entire end face 114 of the substrate, the vertical section of the sealing resin 113 shows an upwardly convex shape due to surface tension. At this time, if the distance between the IC 112 and the substrate end surface 114 is shortened, a small amount of the sealing resin 113 causes a surface tension, and as shown in FIG. And the effect of preventing injury and blocking moisture is improved. Further, the size of the substrate 111 can be reduced.

In this manner, the IC provided in the imaging device at the tip of the electronic endoscope insertion section reduces the distance between the substrate end face and the IC on the substrate fixed in the form of a chip-on-board,
By filling the IC sealing resin to the entire end face, surface tension of the resin is caused, a sufficient thickness for sealing is ensured, and the size of the substrate can be reduced. As a result, it is possible to improve the reliability of sealing the IC chip in the imaging device at the distal end portion of the electronic endoscope, and to reduce the size of the substrate with the downsizing of the imaging device.

[Effects of the Invention] As described above, according to the present invention, since the video signal output line is arranged at a certain distance from the horizontal shift register drive pulse line and the vertical shift register drive pulse line in the imaging cable, There is an effect that the noise induced in the video signal output line is reduced and the deterioration of the image quality can be prevented.

[Brief description of the drawings]

FIGS. 1 and 2 relate to a first embodiment of the present invention.
FIG. 2 is a sectional view showing an image pickup cable, FIG. 2 is an explanatory view showing an endoscope image pickup apparatus, and FIG. 3 to FIG.
FIG. 3 is an explanatory view showing an endoscope apparatus according to the embodiment, and FIG.
The figure is an enlarged sectional view of the tip of FIG. 3, and FIG. 5 is A in FIG.
6 is a perspective view showing the coaxial cable shown in FIG. 3, FIG. 7 is a perspective view showing a simple line in FIG. 3, FIG. 8 is a circuit diagram, and FIG. FIG. 10 is a cross-sectional view of the imaging cable according to the third embodiment, FIG. 10 is a cross-sectional view of the imaging cable according to the fourth embodiment, and FIG. 11 is an explanatory diagram showing a state where an IC mounting board is filled with a sealing resin. 1 ... imaging device, 7, 32, 101, 103 ... imaging cable, 10 ...
… Power supply line, 11… horizontal shift register drive pulse line, 12… vertical shift register drive pulse line, 13
…… Ground line, 14 …… Video signal output line, 16,1
02: Interposed member, 71: Anti-blooming drive pulse line, 72: Noise cancel line.

Claims (1)

(57) [Claims] An image pickup device includes a solid-state image sensor, and a drive signal for driving the solid-state image sensor is transmitted from a signal processing unit via a horizontal shift register driving pulse line and a vertical shift register driving pulse line. The signal is transmitted to the solid-state imaging device, and the output signal of the solid-state imaging device is transmitted to the signal processing means via the video signal output line, and within the same bundle, the horizontal shift register driving pulse line and the vertical shift register driving pulse line And an image signal output line and other various lines are arranged in the endoscope imaging apparatus, wherein the horizontal shift register driving pulse line and the video signal output line and the vertical shift register driving pulse within the same bundle. A video signal output line, a horizontal shift register driving pulse line, and a vertical shift An endoscope imaging apparatus characterized in that lines other than the register driving pulse line are arranged so that the shift register driving pulse line and the video output line are not adjacent to each other.