JP2001046325A - Electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic endoscope which is provided with a fixing means surely mountable to the front end body of the endoscope at an image pickup unit without upsizing. SOLUTION: Lenses 25, 26 and 30, a brightness diaphragm 27 and filters 28 and 29 constituting an objective optical system 31 are set at the outside diameter sizes necessary for passage of rays forming optical images. The rays incident on the objective optical system 31 attain the most converged state when passing the brightness diaphragm 27. As a result, the outside diameter size of the brightness diaphragm 27 is formed to be a required minimum one. The sectional thickness of lens frame 21 is formed to be the largest in the vicinity of the brightness diaphragm 27 since the outside diameter size of the brightness diaphragm 27 is formed to be the smallest. A peripheral groove 41 which is detained and arranged with the front end of a lock screw to constitute a fixing means is formed in such thick 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 constructed by fixing a lens frame of an imaging unit to a main body of a distal end portion of an endoscope.

[0002]

2. Description of the Related Art In recent years, for example, C
A solid-state imaging device such as a CD is built in, and an observation image of an observation target part is formed on an imaging surface of the solid-state imaging device through an objective optical lens, and the image signal of the observation imaging obtained by photoelectric conversion is converted into an electronic endoscope. By transmitting the image signal to a video processing device, which is an external device, through a signal cable, converting the image signal into a video signal, and transmitting the video signal to a monitor, an endoscope image of an observation target portion displayed on a monitor screen is displayed. 2. Description of the Related Art Electronic endoscope devices that can perform treatment or inspection while observing are widely used.

For example, Japanese Patent Application Laid-Open No. 9-222568 discloses an imaging unit of an endoscope having a built-in solid-state imaging device and the like, which is provided in a distal end main body constituting the endoscope.

[0004]

However, the imaging unit of the endoscope disclosed in Japanese Patent Application Laid-Open No. 9-222568 is fixed to the distal end body of the electronic endoscope with an adhesive. For this reason, when disinfecting the electronic endoscope with high-level gas sterilization, there is a problem that the adhesive is deteriorated by the sterilizing gas that has entered the inside of the endoscope, and the bonded and fixed state is destroyed. Was.

In order to cope with this problem, there is a method of mechanically fixing the imaging unit to the distal end main body by using a fastening screw or the like in addition to adhesively fixing the imaging unit to the distal end main body. However, in order to mechanically fix the imaging unit to the distal end main body, it is necessary to provide a fixing means on the imaging unit side, and there is a problem that the provision of the fixing means increases the size of the entire imaging unit. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an electronic endoscope in which an image pickup unit is provided with fixing means that can be securely attached to a distal end main body of the endoscope without increasing the size. The purpose is to do.

[0007]

An electronic endoscope according to the present invention comprises:
A solid-state imaging device, an objective optical system including a plurality of optical lenses for forming an optical image on an imaging surface of the solid-state imaging device, a brightness stop, a filter, and the like, and fixedly holding the optical lens, the brightness stop, and the filter An electronic endoscope for integrally fixing an imaging unit having a lens frame to be mounted to a distal end body constituting an endoscope via mounting means formed on an outer periphery of the lens frame. The means is provided on the outer periphery of the lens frame near the aperture stop arranged on the lens frame.

According to this configuration, the imaging unit constituting the electronic endoscope is fixedly mounted on the distal end body in a stable state.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 relate to a first embodiment of the present invention, FIG. 1 is a view showing a schematic configuration of an electronic endoscope system, FIG. 2 is a view for explaining a configuration of an imaging unit, FIG.
FIG. 3 is a diagram illustrating a configuration of a distal end portion of an insertion portion of the electronic endoscope.

As shown in FIG. 1, an electronic endoscope system 1 including an electronic endoscope (hereinafter also referred to as an endoscope) 2 applied to the present embodiment is used for obtaining an observation image of a portion to be examined. An endoscope 2 in which an imaging unit, which will be described later, is built in the distal end portion 11 of the insertion section of the endoscope 2, a light source device 3 for supplying illumination light to the endoscope 2, a control of the endoscope 2, and an endoscope. A video processor 4 that performs signal processing for generating an image signal obtained by the mirror 2 into a video signal and a monitor 5 that receives the video signal generated and output by the video processor 4 and displays an observation image are mainly provided. The endoscope peripheral device such as a VTR deck, a video printer, or a video disk is connected as needed.

The endoscope 2 includes, for example, an elongated and flexible insertion section 6 which can be inserted into a body cavity, an operation section 7 provided continuously with a base end of the insertion section 6, A universal cord 8 extending from the side of the operation unit 7.

At the base end of the universal cord 8, there is provided a connector section 8a detachable from the light source device 3. From the side of this connector section 8a, a signal cord having an electric connector 9a provided at the base end. 9 is extended. Then, by connecting the electric connector 9a to the video processor 4, the video processor 4 and the endoscope 2 are connected.
And are electrically connected.

The insertion portion 6 includes an insertion portion distal end portion 11 formed of a hard member in order from the distal end side, and a plurality of bending pieces connected in a rotatable manner, for example, a bending portion 1 which can be bent vertically and horizontally.
2. The flexible tube portion 13 having flexibility is continuously provided.

The video processor 4 generates a drive signal for driving the solid-state image sensor, generates an image signal output from the solid-state image sensor into a video signal, and outputs the video signal to the monitor 5 to output the video signal to the monitor 5. Display the observation image on the screen.

By connecting the connector portion 8a to the light source device 3, illumination light generated by a light source lamp disposed inside the light source device 3 is transmitted to the connector portion 8a.
The light is transmitted to the distal end portion 11 of the insertion portion via a light guide (not shown) inserted through the universal cord 8, the operation portion 7, and the insertion portion 6, and is transmitted from the illumination window provided on the distal end surface 11a of the endoscope to the observation site. The light is emitted toward.

The bending section 12 is configured to bend in a desired direction by operating a bending operation knob 14 provided on the operation section 7 at hand. By appropriately operating, the observation window provided on the endoscope distal end surface 11a can be directed in a desired direction.

In addition to the bending operation knob 14, the operation unit 7 includes an air / liquid supply button for controlling an air / liquid supply function, a suction button for controlling a suction function, and light amount adjustment of the light source device 3. The switch is provided for remotely performing the operation.

Reference numeral 7a denotes a treatment tool insertion port for guiding a treatment tool such as a grasping forceps into a body cavity, and a channel tube constituting a treatment tool channel provided in the insertion portion (see reference numeral 19 in FIG. 3). Is in communication with

As shown in FIG. 2, an image pickup unit 20 built in the distal end portion 11 of the insertion section of the endoscope 2 includes a plurality of optical lenses and a brightness stop which constitute an objective optical system described later.
An elongated lens frame 21 having a through-hole for disposing a filter or the like and formed of a metal member such as stainless steel, and a shield case 22 disposed at a base end of the lens frame 21.
And a cable holder 23 having a through-hole fixedly provided on the inner peripheral surface side of the base end of the shield case 22, and a plurality of signal lines having a base end bonded and fixed to the through-hole of the cable holder 23. Signal cable 24 formed
It is mainly composed of

In the through-hole of the lens frame 21, for example, a concave lens 25, a distal convex lens 26, a brightness stop 27, an infrared cut filter 28, a laser cut filter 29, and a proximal convex lens 30 are bonded in order from the distal end side. To form an objective optical system 31.

A cover lens 33 for protecting the imaging surface 32a of the solid-state imaging device 32 is adhered and fixed by an optical adhesive to the inner peripheral surface of the shield case 22 and to the proximal end surface of the proximal convex lens 30. The solid-state imaging device 32 is joined to the base end surface of the cover lens 33 by the optical adhesive.

A flexible lead 34 is electrically connected to the imaging surface 32a side of the solid-state imaging device 32 by bump bonding (not shown).
The base end of the connection 4 is formed, for example, on a side of a circuit board 37 on which a transistor is mounted on one surface as a first electrical component 35 and a chip capacitor or a chip resistor is mounted as a second electrical component 36 on the other surface. It is electrically connected and fixed to the land 37a by solder. The circuit board 3
Reference numeral 7 denotes a plurality of lands (not shown) provided on the base end surface of the circuit board 37 disposed substantially parallel to the solid-state imaging device 32. Each land has a corresponding signal inserted through the signal cable 24. The core wire of the wire 24a is electrically connected. Further, a metal wire 24a is connected to the second electronic component 36 mounted on the circuit board 37, which is a means for preventing heat generation that passes through the signal cable 24.

The metal wire 37 is used to dissipate heat generated from the electronic component 36 and, consequently, heat generated from the entire image pickup unit 20 in, for example, the operation unit 7 to which the other end of the metal wire 37 is connected. It has a function of conducting to a metal piece having a large heat capacity (not shown). That is, the heat generated in the imaging unit 20 is conducted to the metal piece by the metal wire 37 to prevent the temperature of the imaging unit 20 from rising, and the S / N of the solid-state imaging device 32 is reduced.
The ratio is prevented from deteriorating due to temperature rise.

The space surrounding the solid-state imaging device 32 and the circuit board 37 and the space surrounded by the shield case 22 and the cable holder 23 are filled with a transparent and electrically insulating resin member. A sealing portion 38 is provided. A coating surface 39 formed by applying an electrically insulating adhesive is formed on the side surface and the base end surface of the solid-state imaging device 32. The surface is electrically insulated.

The lens 2 constituting the objective optical system 31
5, 26, 30, brightness aperture 27 and filters 28, 2
Numerals 9 are set to diameters necessary for light rays to pass as indicated by dotted lines of arrows A forming optical images. For this reason, the light beam passes through the solid-state imaging device 32 without passing through positions outside the optical axes of the lenses 25, 26, 30, the aperture stop 27, and the filters 28, 29 that constitute the objective optical system 31. The light is incident on the surface 32a.

Light rays incident on the objective optical system 31 are most narrowed when passing through the aperture stop 27. For this reason, the outer diameter of the aperture stop 27 is formed with a minimum necessary outer diameter.

The aperture stop 27 and the convex lens 2
6 and the outer diameters of the cut filters 28 and 29 are smaller than those of the concave lens 25 disposed on the most distal side of the lens frame 21 and the proximal convex lens 30 disposed on the most proximal side. are doing.

The through hole of the lens frame 21 includes a concave lens arrangement hole 21a in which the concave lens 25 is arranged, a distal convex lens arrangement hole 21b having a smaller inner diameter than the concave lens arrangement hole 21a in which the distal convex lens 26 is arranged, The optical member arrangement hole 21c in which the aperture stop 27, the infrared cut filter 28, and the laser cut filter 29 are arranged, and the optical member arrangement hole 2 in which the base-side convex lens 30 is arranged.
It has a base lens arrangement hole 21d having an inner diameter larger than 1c.

An aperture 21e having a small diameter is formed between the front convex lens arrangement hole 21b and the optical member arrangement hole 21c so as to protrude from the inner peripheral surface of the front convex lens arrangement hole 21b and the optical member arrangement hole 21c. The tip-side convex lens 2
6 and a receiving portion 40 for holding the aperture stop 27 are provided.

That is, the through holes formed in the lens frame 21 are concave lens arrangement holes 21a, distal convex lens arrangement holes 21b formed on the distal end side with the aperture hole 21e interposed therebetween, and optical holes formed on the base end side. In the member arrangement hole 21c and the base lens arrangement hole 21d, the arrangement hole located on the outer side has a larger diameter. Further, since the lens frame 21 is formed of a metal member, the arrangement holes 21a, 2
1b, 21c, 21d and the aperture 21e are formed to predetermined dimensions by machining.

As described above, in the arrangement holes 21a, 21b, 21c, 21d formed on the front end side and the base end side with the receiving portion 40 formed in the lens frame 21 therebetween, the arrangement located on the end face side. The lenses 25, 26, and 3 constituting the objective optical system 31 are formed by forming the holes with a large diameter.
0, filters 28 and 29, and aperture stop 27 are respectively fixed in predetermined arrangement holes 21a, 21b, 21c, and 21d, and lenses 25, 26, 30 and filters 28, 29 and the aperture stop 27 can be easily arranged by dropping.

That is, in this embodiment, the concave lens 2
5 and the convex lens on the distal end side are dropped from the opening on the left side shown in the drawing, and the aperture stop 27, the infrared cut filter 28, the laser cut filter 29, and the convex lens 27 on the proximal end are dropped from the opening on the right side in the figure and placed. ing.

The sectional thickness of the lens frame 21 is the smallest in the outer diameter dimension of the aperture stop 27 and the smallest in the vicinity of the aperture stop 27 formed with a smaller diameter than other optical members. It is formed thick. For this reason, a distal end portion of a fixing screw described later is engaged and arranged in the thick portion to form a peripheral groove 41 as a fixing groove having a substantially V-shaped cross section serving as fixing means.

The tip side convex lens 26 is a refractive index distribution type convex lens in which the refractive index changes from the center of the optical lens toward the periphery, and is manufactured by hot pressing to achieve a smaller size and a wider angle. Have been.

In this embodiment, the cross-sectional shape of the peripheral groove is substantially V-shaped, but the cross-sectional shape is not limited to the V-shape, and may be a U-shape.

Further, in the present embodiment, the brightness stop 27 is structured to be supported and fixed by being brought into contact with the receiving portion 40. Instead of providing the brightness stop 27,
The aperture stop 27 may be formed integrally with the lens frame 21. That is, the aperture 21e of the receiving portion 40 may be a brightness aperture.

Although the material of the lens frame 21 is a metal member to enable high-precision machining, when the lens frame 21 needs to be electrically insulated, the lens frame 21 is made of a resin member having electrical insulation. Form.

As shown in FIG. 3, a distal end portion 11 of the insertion portion of the endoscope 2 covers a distal end body 15 formed of a metal member such as a hard stainless steel, and a distal end side of the distal end body 15. It mainly comprises a resin end cover 16.

The distal end main body 15 is provided with a unit arrangement hole 15a for disposing the imaging unit 20 and a channel through hole 15b constituting a treatment instrument channel. The base 16 is inserted into the channel through hole 15b.
The channel tube 19 is communicated and fixed via the.

Further, a through hole 15c with a female thread is formed in the side peripheral surface of the distal end main body 15 so as to penetrate perpendicularly to the unit arrangement hole 15a.

Here, the distal end body 1 of the imaging unit 20
5 will be described. First, the imaging unit 20 is inserted and arranged in the unit arrangement hole 15a. Next, a fixing screw 17 is screwed into the through-hole 16 c with a female thread, and a tip end of the fixing screw 17 is engaged with a circumferential groove 41 formed in the lens frame 21. This allows
With the distal end surface of the lens frame 21 in contact with a fixing portion 15d formed on the distal end body 15, the imaging unit 2
0 is securely fixed to the distal end body 15 without being displaced in the insertion axis direction.

The image pickup unit 20 is also fixed by an adhesive. In addition, this imaging unit 20
The signal cable 24 extending from the base end of the connector cable 8 extends through the insertion section 6, the operation section 7, and the universal cord 8 to the connector section 8a. Further, a gap 18 formed between the unit arrangement hole 15a and the imaging unit 20 is formed.
Is filled with a silicone adhesive 10 as a reinforcing member.

As described above, the fixing screw is engaged and arranged,
A peripheral groove for fixing the imaging unit to the main body of the distal end portion with a fixing screw has a small outer diameter required in the objective optical system arranged in the lens frame, and is the largest among the optical members constituting the objective optical system. The imaging unit can be firmly fixedly arranged at a predetermined position of the distal end body while maintaining the miniaturization of the entire imaging unit by forming the imaging unit in the thick portion of the lens frame where the vicinity of the small-diameter aperture stop is located. .

As a result, the image pickup unit is firmly fixed by the adhesive and the fixing screw. Therefore, even if the adhesive is deteriorated by a sterilizing gas or the like, the image pickup unit may be detached from the tip main body or displaced. Is prevented, and the quality of the electronic endoscope for a long time is maintained.

Also, the diameter of the arrangement holes formed on both sides of the aperture formed in the lens frame increases as the distance from the aperture increases.
A lens frame having a plurality of arrangement holes can be formed with high precision, and an optical member constituting the objective optical system can be easily assembled by dropping an optical member constituting one of the openings formed in the lens frame.

This eliminates the need for a lens frame for holding an optical lens in a conventional imaging unit to be composed of a plurality of members. Further, a separate member such as an interval holding member for keeping the interval between the optical lenses at a predetermined amount is not required, and a high-precision imaging unit which is easy to process and assemble and has little dimensional variation is provided at low cost.

It should be noted that as shown in FIG.
By providing a bent portion 43 on the base end side of the distal end main body 15 that abuts on the cable holder 23 and holds the imaging unit 20, the strength in the axial direction is further strengthened and the imaging unit 20 is moved to the distal end. It can be fixed to the main body 15.

The bent portion 4 is attached to the tip end body 15.
3 instead of providing the fixing pins 44 as shown in FIG.
Is arranged to press the vicinity of the cable holder 23, the same operation and effect as those having the bent portion 43 shown in FIG. 4 can be obtained. In the present embodiment, a fixing screw may be provided instead of the fixing pin 44.

In the configuration shown in FIG. 5, a through hole 45 is formed in the distal end body 15 so as to penetrate at right angles to the unit arrangement hole 15a, like the through hole 15c with the female thread. A heat dissipating member formed of a member having high thermal conductivity is arranged in the through hole 45. One end surface of the heat radiating member disposed in the through hole 45 is connected to the lens frame 21.
, And the other end face is arranged near the surface of the tip end body 15. This allows the heat generated inside the imaging unit 20 to be conducted to the heat radiating member and released to the outside of the endoscope, thereby preventing the temperature of the imaging unit 20 from rising.

FIG. 6 is a view for explaining the configuration of an imaging unit according to the second embodiment of the present invention. As shown in FIG. 6, in the present embodiment, as in the first embodiment, a cover lens 33a for protecting the imaging surface 32a of the solid-state imaging device 32 is arranged, and the outer shape of the cover lens 33a is It is formed in a quadrangular shape according to the shape of the imaging surface 32a of the solid-state imaging device 32.

A laser cut filter 29a and an infrared cut filter 28a are bonded to the tip end side of the cover lens 33a by an optical adhesive, and the cover lens 33a, the laser cut filter 29a, and the infrared cut filter 28a are joined. , The solid-state imaging device 32 constitutes an integrated assembly. Therefore, the outer shapes of the laser cut filter 29a and the infrared cut filter 28a are formed in a quadrangular shape having the same shape and dimensions as the cover lens 33a.

For this reason, the sectional shape of the space where the infrared cut filter 28a, the laser cut filter 29a and the cover lens 33a of the lens frame 21A are arranged is formed in a quadrangular shape.

In this embodiment, similarly to the first embodiment, the peripheral groove 41A in which the fixing screw 17 is engaged and disposed in the thick portion near the aperture stop 27 formed with the minimum required outer diameter. Is formed.

In this embodiment, the sectional shape of the peripheral groove 41A is concave. Reference numeral 46 denotes a cemented lens for supporting and fixing the aperture stop 27 in contact with the receiving portion 40. Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals and description thereof will be omitted.

As described above, by forming the outer shape of the laser cut filter and the infrared cut filter in conformity with the cover lens formed in a square shape in accordance with the shape of the imaging surface of the solid-state image sensor, the workability and the workability are improved. The assemblability can be improved.

By forming the cross-sectional shape of the peripheral groove into a concave shape, the imaging unit can be easily fixed to the main body of the distal end portion by a general screw having a flat distal end portion.

As shown in FIG. 7, the circumferential grooves 41, 41A
A similar effect can be obtained by providing a step 47 in a thick portion near the brightness stop 27 of the lens frame 21B instead of forming the step.

It should be noted that the present invention is not limited to only the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.

[Appendix] According to the above-described embodiment of the present invention as described in detail above, the following configuration can be obtained.

(1) An objective optical system including a solid-state imaging device, a plurality of optical lenses for forming an optical image on an imaging surface of the solid-state imaging device, and a brightness stop, and the optical lens and the brightness stop An electronic endoscope for integrally fixing an imaging unit having a lens frame to be fixedly held to a distal end main body constituting an endoscope through an attaching means provided on an outer periphery of the lens frame, An electronic endoscope wherein the mounting means is provided on an outer periphery of the lens frame near a brightness stop arranged on the lens frame.

(2) The electronic endoscope according to appendix 1, wherein the attachment means is a peripheral groove formed on an outer periphery of the lens frame.

(3) The electronic endoscope according to appendix 1, wherein the attachment means is a step formed on an outer peripheral portion of the lens frame.

(4) A plurality of optical lenses and an aperture stop,
An objective optical system provided with a filter and the like, and a plurality of these optical lenses and an aperture stop, and a lens frame having a through hole in which the filter is disposed, and an optical lens and an aperture stop formed in the lens frame An electronic endoscope in which the diameter of the arrangement hole in which the filter is fixed is increased as the distance from the arrangement hole in which the brightness stop is arranged to the distal end side or the base end side increases.

[0064]

As described above, according to the present invention, there is provided an electronic endoscope in which an image pickup unit is provided with a fixing means which can be securely attached to the distal end main body of the endoscope without increasing the size. be able to.

[Brief description of the drawings]

FIGS. 1 to 3 relate to a first embodiment of the present invention, and FIG. 1 shows a schematic configuration of an electronic endoscope system.

FIG. 2 illustrates a configuration of an imaging unit.

FIG. 3 is a diagram illustrating a configuration of a distal end portion of an insertion portion of the electronic endoscope.

FIG. 4 is a diagram illustrating another configuration of the distal end portion of the insertion portion of the electronic endoscope.

FIG. 5 is a diagram illustrating another configuration of the distal end portion of the insertion section of the electronic endoscope.

FIG. 6 is a diagram illustrating a configuration of an imaging unit according to a second embodiment of the present invention.

FIG. 7 is a diagram illustrating another configuration of the imaging unit.

[Explanation of symbols]

 Reference Signs List 20 imaging unit 21 lens frame 27 aperture stop 31 objective optical system 32 solid-state imaging device 41 circumferential groove

Claims (1)

[Claims] An objective optical system including a solid-state imaging device, a plurality of optical lenses for forming an optical image on an imaging surface of the solid-state imaging device, a brightness stop, a filter, and the like, and the optical lens and the brightness stop An electronic endoscope in which an imaging unit including a lens frame for fixing and holding a filter is integrally fixed to a distal end body constituting an endoscope via an attaching means formed on an outer periphery of the lens frame. An electronic endoscope, wherein the attachment means is provided on an outer periphery of a lens frame near a brightness stop arranged on the lens frame.