JPH07184854A - Electronic endoscope - Google Patents

Abstract

PURPOSE:To achieve a finer diameter even when an insertion part is long-sized. CONSTITUTION:A CCD20 is arranged on a focal plane of a group of objective lenses 19 housed into a tip part 7 of an insertion part. A signal line requiring a larger diameter is given a proper outer diameter according to a signal involved on the side of the signal line connected to the CCD20 and the outer diameter of other signal lines is made smaller. The signal lines are bundled to be inserted through the insertion part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope using signal wires having different outer diameters.

[0002]

2. Description of the Related Art A signal line used in a conventional electronic endoscope is composed of a plurality of signal lines such as an image pickup device drive system, a video transmission system, a power supply line, and the like, regardless of the type of signal. The finishing outer diameter was the same and they had a structure in which they were bundled). For example, FIG. 12 shows a configuration of a conventional signal line bundle disclosed in Japanese Patent Laid-Open No. 2-112388.

This signal line bundle has three layers of insulating tape 111, integrated shield 112, and integrated jacket 113, and an anti-blooming drive pulse line 114, a ground line 115, a power supply line 116, a horizontal shift register drive pulse line 117, and a vertical shift. In addition to the register drive pulse line 118 and the video signal output line 120, an intervening member 119 for balancing is incorporated.

[0004]

Among industrial electronic endoscopes, there are endoscopes having a long insertion portion. Along with this, the signal line length becomes long, and it becomes difficult to transmit a high-frequency horizontal transfer drive signal, a CCD drive signal such as a CCD output gate reset pulse, and the like. To prevent this, a large diameter signal line is required.

However, as in the prior art, when the signal wires for the high frequency transmission having the largest finished outer diameter and the same diameter are formed into a bundle, the occupied area of the signal wire bundle becomes large. As a result, the outer diameter of the endoscope distal end portion becomes large.

The present invention has been made in view of the above points, and an object of the present invention is to provide an electronic endoscope capable of achieving a reduction in diameter even if the insertion portion is elongated.

[0007]

[Means and Actions for Solving the Problems] Signal wires that require a large diameter should have an appropriate outer diameter according to the signal, and the other signal wires should have a small outer diameter to form a bundle. did.
As a result, the area occupied by the signal line bundle can be reduced, and the diameter of the insertion portion can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a configuration diagram of an endoscope system including the first embodiment, and FIG. 2 shows a structure of a distal end side of an insertion portion. 3 shows the structure of the signal line bundle, FIG. 4 shows a flare diaphragm formed by depositing chromium on a crystal filter, FIG. 5 shows a holding frame, and FIG. 6 shows a reinforcing member in the section AA of FIG.

As shown in FIG. 1, an endoscope system 1 includes an electronic endoscope 2 of a first embodiment having a built-in image pickup means, a light source device 3 for supplying illumination light to the electronic endoscope 2, and an image pickup. A camera control unit (hereinafter abbreviated as CCU) 4 as a signal processing means for performing signal processing to the means, and a color monitor 5 for displaying a video signal output from the CCU 4 are provided, and a tip portion of the insertion portion 6 is formed. A visual field conversion adapter (hereinafter simply referred to as an adapter) 8 for performing visual field conversion can be detachably attached to the device 7.

The electronic endoscope 1 has a long insertion portion 6, an operation portion 9 connected to a proximal end portion of the insertion portion 6 and having a bending operation knob (not shown), and a side of the operation portion 9. The light guide cable 10 is extended from the portion to the outside, and the light guide connector 11 is attached to the tip of the extended light guide cable 10.

By connecting the light guide connector 11 to the light source device 3 in a detachable manner, the illumination light of an illumination lamp (not shown) disposed inside the light source device 3 enters the light guide connector 11. .

This illumination light is emitted from this light guide cable 1
0 is transmitted by the light guide fiber 12 inserted through the inside of the insertion portion 6 and the inside of the insertion portion 6, and the illumination window 1 of the tip portion 7 of the insertion portion 6 is transmitted.
Light is emitted forward from the emission end face of the light guide fiber 12 attached to the light guide fiber 3. When the adapter 8 is connected, illumination light is further emitted from the adapter illumination window 15 via the adapter illumination lens group 14.

A subject illuminated by this illumination light is a group of adapter objective lenses 17 functioning as a field conversion optical system of the adapter observation window 16 and an observation window 18 provided at the tip end portion 7.
An image is formed on a CCD 20 as a solid-state image pickup device through an objective lens system 19 attached to and is photoelectrically converted by this CCD 20. An objective lens unit 21 to which the objective lens system 19 is attached and a CC to which the CCD 20 is attached
An image pickup unit 23 is formed with the D unit 22.

The image signal photoelectrically converted by the CCD 20 is transmitted by the signal line bundle 36. This signal line bundle 36
Is a branch cable 25 inserted through the insertion portion 6 and the light guide cable 10 and branched from the light guide connector 11, and a CC provided at an end of the branch cable 25.
It is transmitted to the CCU 4 via the U connector 26. The signal line bundle 36 will be described in more detail later.

The details of the tip portion 7 will be described with reference to FIGS. An imaging unit 23 including an objective lens unit 21 and a CCD unit 22 is arranged inside the tip portion 7 shown in FIG. Observation window 18 at the tip 7
A lens frame 31 is attached to the lens frame 31, and the objective lens group 19 is provided in the lens frame 31. This lens frame 31
And the objective lens group 19 constitute an objective lens unit 21.

On the other hand, the CCD unit 22 has the following structure. The crystal filters 32 are joined to the CCD 20 in a state where they are adjusted concentrically with each other, and are incorporated in the holding frame 33. On the surface of the crystal filter 32 on the distal end side of the endoscope, as shown in FIG.
4 is given.

A substrate 35 on which a hybrid IC and a resistor (not shown) are mounted is joined to a lead (not shown) on one side of the CCD 20. A part of the signal lines of the signal line bundle 36 is connected to the substrate 35. The remaining signal lines of the signal line bundle 36 are directly connected to the leads 37 on the other side.

Each signal line of the signal line bundle 36 is connected to the CCU.
It is guided to each contact portion of the connector 26. The configuration of the signal line bundle 36 will be described. FIG. 3 is a configuration diagram of the signal line bundle 36 in the first embodiment. The signal line of the imaging unit 23 is
CCD output gate reset pulse (hereinafter referred to as φR) signal line 38, CCD horizontal transfer drive signal (hereinafter referred to as φH) signal line 39, CCD vertical transfer drive signal (hereinafter φ)
V) signal line 40, video output signal (hereinafter Vout
Signal line 41, a power supply line 42, and a ground line 43.

Of these signal lines, the φR signal line 38 and the φH signal line 39 for driving the CCD, which are high frequency signals, are thick signal lines. Other φV signal line 4
0, the signal line 41 for Vout, the power supply line 42, and the ground line 43 are signal lines having outer diameters smaller than those for the above high-frequency signals (φR, φH).

In the present embodiment, pure single wires are used for the power supply line 42 and the ground line 43, and the other signal wires are coaxial signal wires provided with a metal shield on the core wire coating in order to avoid the influence of noise. . The signal wire bundle 36 bundles the signal wires of the numbers 38 to 43, and the outermost skin is covered with a metal blade 44 having a shielding property.

As shown in FIG. 2, a conductive wire 46 is connected to the shield part 45 of the coaxial signal line, and one end of the conductive wire is connected to the ground line on the substrate 35. The heat-shrinkable tube 4 is provided around the conductive wire 46 of the shield part 45.
7 is coated.

As shown in the perspective view of FIG. 5, the holding frame 33 has three projections 49a for holding the assembly of the lens frame 31, the fitting portion (cylindrical portion) 48, the crystal filter 32, and the CCD 20. To c (represented by 49 in FIG. 2) are provided.

A light shielding member 50 is fitted to a part of the outer circumference of the protrusions 49a to 49c so as to abut the cylindrical portion 48, and a black heat shrinkable tube 51 covers the periphery from the light shielding member 50 to the CCD 20. Has been done.

As shown in FIG. 6 (A-A cross section of FIG. 2), a semi-cylindrical reinforcing member 52 is provided on the outer peripheral portions of the protrusions 49a and 49b.
Is provided on the rear side of the light shielding member 50 (this reinforcing member 52
Is extended to a fixing portion 53 described later). The CCD unit 22 configured as described above is fixed by the filling material in the region from the CCD 20 to the end of the signal line bundle 36 (the tip of the outer shield blade 44 of the signal line bundle 36 is fixed by the fixing portion 53). ).

The objective lens unit 21 and the CCD unit 22 are fitted with a fitting portion 48 so that the CCD surface is in focus.
The position of is adjusted and fixed. The imaging unit 23 is
At the lens frame 31, the tip body (hereinafter referred to as the body) 5
Stopped at 5. An illumination lens 56 is provided on the main body 55, and the light guide fiber 12 is continuously provided immediately after the illumination lens 56.

An adapter 8 for converting the direction of view, the angle of view, the observation depth, etc. is attached to the tip portion 7. The adapter 8 is composed of an adapter body 57 (hereinafter referred to as an AD body), a retaining ring screw 58, and a retaining member 59. The AD main body 57 is provided with an adapter objective lens group 17 and an adapter illumination lens group 14.

The retaining ring screw 58 has a protrusion 60 at the front end thereof sandwiched between the main body 57 and the retaining member 59 with a certain space, and is rotatably provided on the AD main body 57. On the inner circumference of the retaining ring screw 58,
A first female screw 61 and a second female screw 62 are provided, and are attached to the adapter 8 by being screwed with a tip cover 63 fixed to the tip body 55.

A female screw 6 is provided on the inner circumference of the tip portion of the tip cover 63.
4 is provided, and this female screw 64 is used for the tip body 55.
The distal end cover 63 and the distal end portion main body 55 are fixed by screwing with each other and further turning an adhesive on the fitting surface 65 of both.

Tip base 68 connected to the outer sheath 66
Is fitted to the tip cover 63 so as to abut against the male screw 67 portion provided on the outer circumference of the tip cover 63. Further, the male screw 69 provided on the distal end portion of the distal end cap 68 and the male screw 67 are screwed together with the ring nut member 70, whereby the distal end cap 68 is fixed to the distal end cover 63.

The operation of this embodiment will be described based on the above configuration. By providing the chromium vapor deposition part 34 on the surface of the crystal filter 32 on the front end side, unnecessary out-of-field light rays are cut and prevented from entering the CCD 20 and causing flare.

Further, by extending the reinforcing member 52 to the fixing portion 53 on the outer peripheral portions of the protrusions 49a and 49b of the holding frame 33, the image pickup unit 23 is provided with tensile strength and warp strength. Further, the reinforcing member 52 is made of metal, and has a heat radiation function of the hybrid IC mounted on the substrate 35.

Of the signal lines connected to the image pickup unit 23, the signal lines of φR, φH, φV and the power source are used to drive the CCD 2
0 is driven and the output signal from the CCD 20 is transmitted through the Vout signal line 41.

Of these signal lines, those for φR and φH are high-frequency signals for driving, and thick signal lines (corresponding to the signals) are used so that the signals are not attenuated when lengthened.

If these signal lines are made to have an appropriate diameter, the impedance will be reduced even if they are elongated, and the attenuation of the high frequency drive signals (φR, φH) can be prevented.

Signals Vou other than φR and φH
Regarding the signal lines of t, the power supply, and the ground, the signal lines other than the high-frequency signals are thinner than the high-frequency signals φR and φH, and are composed of signal lines of two types of thickness. These signal lines are bundled in order to enhance the holding property.

By covering the outer circumference of the conductive wire material 46 wound around the coaxial shield portion of the coaxial signal wires of φR, φH, φV, and Vout with the heat-shrinkable tube 44, the outer skin of the signal wire bundle 36 is prevented from contacting. ing. The conductive wire member 46 is connected to the ground line of the substrate 35 and is electrically connected to the ground line simple wire 43 connected to the ground line.

In operation, the simple line 43 for the ground line is not provided, and the coaxial signal line coaxial shield portion 4 of the signal line bundle 36 is provided.
5 can also be used as a ground line. According to the first embodiment, by making the signal lines of φR and φH thick, it is possible to transmit a stable drive signal even when the length is increased.

Next, a second embodiment of the present invention will be described. Figure 7
FIG. 9 shows the configuration of the signal line bundle in the second embodiment of the present invention.

The signal line bundle is a coaxial signal line bundle (φR,
φH, φV, Vout) 74 and a single-line signal line bundle (power source, ground) 75, and two signal line bundles. At this time, the driving high-frequency signals φR and φH are thick as in the first embodiment, and the other signal lines are thin. Even if two cables are used, the occupied area is smaller than the conventional signal wire bundle having the same diameter. Other functions of this embodiment are similar to those of the first embodiment.

According to this embodiment, two signal line connecting portions (direct connection to the CCD and connection to the substrate) divided into two forks are independently provided to the two signal line bundles 74 and 75 and to the predetermined position. Since it can be mounted, it does not require excessive force on the signal line during assembly. Others are the same as those in the first embodiment.

Next, a third embodiment of the present invention will be described. Figure 8
Shows the structure of the signal line bundle 76 in the third embodiment of the present invention. The video output signal (Vout) 41 is made thicker than other signal lines to form a bundle. The operation of this embodiment is similar to that of the first and second embodiments.

According to the present embodiment, by thickening the Vout signal line diameter, there is an effect that the video output is not attenuated. Also, since the wires other than the Vout signal line are thin,
The area occupied by the signal lines is small, and it becomes easy to process the signal lines into a bundle. This simplifies the structure inside the tip and facilitates the assembly of the tip around the CCD. In this case, it is more advantageous to reduce the diameter of the scope because only one is required to be thick.

Next, a fourth embodiment of the present invention will be described. This electronic endoscope is based on the electronic endoscope 2 disclosed in JP-A-5-211988. The tip of the electronic endoscope 2 disclosed in FIG. 2 of this publication is shown in FIG.
Shown in.

On the other hand, the electronic endoscope 81 according to the fourth embodiment has a B-C-D cross section as shown in FIG. 10 when the front view is shown in FIG. 9 (b). As shown in FIG. 9B, illumination lens systems 82, 82 are arranged on both sides of a line connecting the projection lens 35 ', the objective lens system 29', and the laser spot projection unit 28 ', and the cross section including the illumination lens system 82 is It becomes like FIG.

The objective lens system 29 'is composed of a lens 83, a lens 84, an optical low pass filter 85, and a CCD 86. The illumination lens system 82 includes a light guide filter 87, an infrared cut filter 88, and an illumination lens 89.
It is composed of

The infrared cut filter 88 is supported by the base 90. The base 90 is made of a material having good thermal conductivity such as copper, and radiates the heat absorbed by the infrared cut filter 90. The tip of the light guide filter 87 is fixed to the inside of the base 90 via the base 91. The signal line bundle 92 connected to the CCD 86 is, for example, the video output signal (Vout) 4 as in the third embodiment.
1 is made thicker than other signal lines to form a bundle. The other configurations are the same as those disclosed in the above publication.

The operation of this embodiment will be described. Light from an unillustrated illumination light source 3 (see FIG. 1 of the publication) is guided through a light guide fiber 87, passes through an infrared cut filter 88, and is projected onto an object plane by an illumination lens 89.
On the other hand, the objective lens system 29 'is C
An image is obtained on the CD surface. Lenses 83 and 84 and CCD
An optical low-pass filter 85 is provided between 86, and CC
Moire on the D surface is prevented.

By the infrared cut filter 88, the light from which the infrared region of the illumination light source is removed is projected onto the object plane,
The reflected light is imaged on the CCD surface by the objective lens system 29 '. In general, a color CCD has a light receiving sensitivity in the infrared region as well, so that correct color reproducibility cannot be obtained unless an infrared cut filter is provided in the image pickup optical system.

Further, semiconductor lasers 52a and 62b (see FIG. 6 of the publication) generally used for the laser light source 7 (see FIG. 1 of the publication).
In most cases, the wavelength is 630 nm or more, and it falls on the attenuation range of the infrared cut filter used in the image pickup system. If the image pickup system includes an infrared cut filter, the light receiving sensitivity of the laser light is significantly increased. There is a problem that it will decrease. In this embodiment, since the infrared cut filter is not provided in the image pickup optical system but is provided in the illumination lens system 82, the CCD 86
It is possible to prevent the infrared light receiving sensitivity from being lowered.

Further, the object image illuminated by the illumination lens system 82 that has passed through the infrared cut filter 88 is received by the CCD 86, and correct color development is obtained. As a result, in three-dimensional measurement using interference fringes using laser light, color reproduction is not required and only light intensity is required, so that interference fringes can be obtained with good sensitivity.

Therefore, a low power semiconductor laser can be used. Further, by using a semiconductor laser of small power, it is safer for the human body (eyes). In addition, since the price is low, a three-dimensional measuring endoscope system can be provided at a low price. Others have the same effects as those of the third embodiment. The infrared cut filter may be an infrared reflection type.

Next, a modification of the fourth embodiment will be described. The electronic endoscope of this modification is the illumination lens system 82 in FIG.
In place of the infrared cut filter 88, a plane parallel plate which is optical glass is inserted.

On the other hand, as shown in FIG. 11, the plug 10 of the light source connector 14 '(in the electronic endoscope of this modification).
A light guide fiber 87, an infrared cut filter 103 for color color correction, and a rod lens 104 are provided in the unit 1.

On the other hand, the lamp 105 is provided on the side of the illumination light source 3 '.
And a heat ray absorption filter 106 are provided, and the light of the lamp 105 is condensed on the end surface of the rod lens 104 of the plug 101.

The light passing through the rod lens 104 is color C
Infrared cut filter 1 provided for color correction for CD
After passing through 03, it enters the light guide fiber 87. This light is projected from the tip of the endoscope onto the object plane, and the reflected light is received by the CCD 86 of the objective lens system 29 '.

[0056]

As described above, according to the present invention, the outer diameter of the signal line other than the signal line for high frequency transmission requiring a large diameter is made thin, and the signal lines having different diameters are combined to form a bundle. This makes it possible to make all signal lines the same as the outer diameter for high-frequency signals, which is the thickest, and to make the occupied area of the signal line bundle smaller than the bundled one, and to lengthen the outer diameter of the signal line for high-frequency signals. It is possible to reduce the diameter even in a thick endoscope.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an endoscope system including a first embodiment.

FIG. 2 is a cross-sectional view showing the structure on the distal end side of the insertion portion.

FIG. 3 is an explanatory diagram showing a configuration of a signal line bundle.

FIG. 4 is a view showing a flare diaphragm having chromium deposited on a crystal filter.

FIG. 5 is a perspective view showing a holding frame.

6 is a cross-sectional view showing the reinforcing member in the AA cross section of FIG.

FIG. 7 is an explanatory diagram showing a configuration of a signal line bundle in the second embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a configuration of a signal line bundle according to a third embodiment of the present invention.

FIG. 9 is a front view showing a distal end surface of an insertion portion according to a fourth embodiment of the present invention.

FIG. 10 is a sectional view taken along line B-C-D in FIG.

FIG. 11 is a cross-sectional view showing a structure near a light source connector in a modification of the fourth embodiment.

FIG. 12 is a diagram showing a configuration of a signal line bundle in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Endoscope system ... 2 Electronic endoscope 3 ... Light source device 4 ... CCU 5 ... Color monitor 6 ... Insertion part 7 ... Tip part 8 ... View conversion adapter 10 ... Light guide cable 11 ... Light source connector 19 ... Objective lens group 20 ... CCD 22 ... CCD unit 23 ... Imaging unit 32 ... Crystal filter 35 ... Substrate 36 ... Signal line bundle 38 ... φR signal line 39 ... φH signal line 40 ... φV signal line 41 ... Vout signal line 42 ... Power supply Signal line 43 ... Signal line for ground 44 ... Metal blade

Claims (1)

[Claims] 1. An electronic endoscope having a solid-state image sensor at its tip, having a signal line for transmitting an output signal from the solid-state image sensor and a signal line for transmitting a drive signal and the like to the solid-state image sensor. The electronic endoscope, wherein the signal lines have different outer diameters.