JP2000075218A - Endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an endoscope which prevents the intrusion of dust between objective lenses and a solid-state image pickup element and facilitates the regulation of foci and optical axes in spite of the occurrence of variation in optical performance at the time of assembling and exchanging an optical unit in the mounting constitution of the optical unit consisting of the objective lenses arranged at the main body at the front end of the endoscope and the solid-state image pickup element. SOLUTION: This endoscope includes the lens barrel 14, which holds the plural objective lenses 15a to 15c and is formed with an external thread part and fitting part on the outer peripheral part, and an element holding cylinder 20, which holds the solid-state image pickup element 13 and has an internal thread part and fitting part formed in the inner peripheral part on the image forming face side of the solid- state image pickup element 13. Both fitting parts of the lends barrel 14 and the element holding cylinder 29 are slid and fitted to each other and the external thread part of the lens barrel 14 and the internal thread part of the element holding cylinder 20 are screwed to each other. The endoscope has an image pickup unit 40 which adjusts the advance and retreat of the solid-state image pickup element 13 and the objective lenses 15a to 15c in their optical axis direction by this screwing dimension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope which is inserted into a body cavity for observing a deep part or performing a therapeutic treatment using a treatment tool, and is particularly provided at the distal end of the endoscope to photograph the deep part. The present invention relates to an objective lens and a solid-state imaging device.

[0002]

2. Description of the Related Art An objective lens for capturing a subject image at a distal end inserted into a body cavity, and a solid-state imaging device for converting the subject image captured by the objective lens into an electric signal are incorporated, and an electric signal generated by the solid-state imaging device is provided. In an endoscope that displays on a television monitor, during operation, handling or transportation of the endoscope, the solid-state image pickup device or the insertion unit tip where the objective optical system lens for guiding subject light is arranged is placed on a solid object. When dropped or collided, the objective lens is often damaged, and it is necessary to replace the damaged objective lens with a new lens. Japanese Patent Application Laid-Open No. 61-59309 and Japanese Patent Application Laid-Open No.
2-66220 and JP-A-63-2016.

In an endoscope disclosed in Japanese Patent Application Laid-Open No. 61-59309, a male screw is formed on the entire outer periphery of a lens barrel holding and fixing an objective lens system, and a solid-state imaging device is held and fixed. A female screw is formed on the entire inner circumference of the tube, and the male screw and the female screw are screwed and rotated relative to each other, so that an optical unit that can advance and retreat in the optical axis direction penetrates the end body of the endoscope in the axial direction. It is inserted densely into the hole, and is fixed with screws via mounting holes formed in the outer peripheral side surface of the tip main body.

In the endoscope having such a configuration, when the objective lens system is damaged, the screwing of the element holding tube and the lens tube is released, and a new lens tube is attached to the element holding tube. Although it will be screwed, the outer periphery of the lens barrel,
Since the male screw or the female screw is formed on the entire inner periphery of the element holding cylinder, the screw thread is chipped or dust is mixed in when the screwing is released or re-threaded. Further, due to the play between the male screw and the female screw, a deviation may occur between the optical center axis of the lens and the optical center axis of the solid-state imaging device during attachment and fixing to the tip main body by screw fixing. Careful and skilled work is required to prevent chipping of the threads and deviation of the optical axis.

In the endoscope disclosed in Japanese Patent Application Laid-Open No. 62-66220, a solid-state imaging device is disposed inside a fitting hole provided in the axial direction of a distal end main body, and an inner periphery of the fitting hole is provided. The female screw is formed in the female screw. On the other hand, a male screw is formed on the outer periphery of the lens barrel that holds the objective lens, and this objective lens barrel fits into a fitting hole of the distal end main body, and is screwed with a male screw and a female screw to form the male screw. It is attached and fixed to the tip body.

In the endoscope having such a configuration, when the male screw and the female screw of the objective lens barrel and the distal end main body are screwed together, chipping of the screw thread or dust mixing occurs. Also, the solid-state image sensor is solid in the tip body, and when replaced with a lens barrel that holds a new objective lens, the focal length between the objective lens and the solid-state image sensor differs due to the variation in the optical performance of the lens. Occurs, and the objective lens projects or retracts from the distal end main body, so that a step is generated between the distal end of the objective lens and the distal end main body, and the step causes the endoscope end portion to be inserted into the body cavity when inserted into the body cavity. Can be a factor.

The endoscope disclosed in Japanese Patent Application Laid-Open No. 63-2016 has a lens frame to which an objective lens is attached and fixed, and a fixed frame to which a solid-state image sensor is attached and fixed.
The lens frame is fitted into the fixed frame, and an imaging unit fixed by screws from the outer peripheral direction of the fixed frame is inserted into a fitting hole provided in the axial direction of the distal end body,
A screw is fixed from the outside of the tip main body.

In the endoscope having such a configuration, the fixing frame for fixing the solid-state image pickup device and the objective lens frame are fixed to the distal end body with screws. And the shape and dimensions of the endoscope inserted into the body cavity are inappropriate.

[0009]

SUMMARY OF THE INVENTION An optical unit, which is disposed on a distal end main body of a conventional endoscope and comprises an objective lens and a solid-state image pickup device for converting subject light captured by the objective lens into an electric image signal, is mounted and fixed. In the configuration, when the optical unit is exchanged, dust easily enters the objective lens surface or the imaging surface of the solid-state imaging device, and a replacement objective lens having no variation in optical performance is required. There is a problem that requires skilled work for repair management.

According to the present invention, it is possible to prevent dust from entering when repairing an optical unit including an objective lens and a solid-state imaging device incorporated in a distal end body provided at a distal end portion of an endoscope.
It is another object of the present invention to provide an endoscope that does not require skilled work for adjusting the focus between the objective lens and the solid-state imaging device.

[0011]

SUMMARY OF THE INVENTION The present invention relates to an endoscope having an imaging unit including a plurality of objective lenses for imaging a subject and a solid-state imaging device for converting a subject image taken by the objective lens into an electric signal. A lens barrel holding the plurality of objective lenses on an inner peripheral portion, a male screw portion and a fitting portion formed on an outer peripheral portion, and holding the solid-state imaging device on an inner peripheral portion, and forming an image of the solid-state imaging device. An element holding cylinder having a female screw portion and a fitting portion formed on the inner peripheral portion on the surface side, and both the fitting portions of the lens tube and the element holding tube are slidably fitted together, A male screw part of the lens barrel and a female screw part of the element holding barrel are screwed together, and an image pickup unit that adjusts the solid-state image pickup element and the objective lens in the optical axis direction by this screwing dimension is provided. It is an endoscope.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of an endoscope according to the present invention. FIG. 1 shows an insertion portion 1 to be inserted into a body cavity of an endoscope, and a distal end portion 2 of the insertion portion 1. The distal end portion 2 is connected to a bending portion 3.

The distal end portion 2 has a substantially cylindrical distal end portion main body 4 and a distal end cover 5 fitted on the outer periphery of the distal end side of the distal end portion main body 4. The tip cover 5 is made of an electrically insulating material. A fixed piece 7 that is connected to the movable piece 6 of the bending portion 3 is fitted and fixed to the outer periphery of the rear end side of the tip component main body 4. An outer skin 8 made of an electrically insulating material is fitted around the movable piece 6 to the fixed piece 7 and the outer periphery of the distal end component main body 4 of the bending portion 3.

An illumination window (not shown), an observation window 10, an air / water nozzle (not shown), and a suction port 11 are provided on the tip surface 9 of the tip cover 5. An objective lens system 12 is arranged in the observation window 10, and a subject image in a visual field observed through the objective lens system 12 is formed on a light receiving surface of the solid-state imaging device 13.

The objective lens system 12 is composed of a plurality of objective lenses 15a to 15c held and fixed to a lens barrel 14. The outer periphery of the distal end of the lens barrel 14 is provided on the distal end component main body 4 and the distal end cover 5 by silicon. It is hermetically attached with an elastic adhesive such as a system. The positioning of the lens barrel 14 in the axial direction is such that a step 17 provided on the distal end side of the lens barrel 14 is arranged to abut against the inner surface of the distal end of the distal end component main body 4, and the outer periphery of the distal end of the lens barrel 14. A positioning screw 18 is fitted and fixed from the outer periphery of the front end cover 5 into the groove 19 provided in the above, and the head of the positioning screw 18 is filled with an elastic adhesive 16 made of silicon or the like. Further, a male screw 21 to which an element holding tube 20 described later is connected is formed on the outer periphery of the central portion of the lens tube 14, and the element screw is formed on the outer periphery of the rear end of the lens tube 14 on which the male screw 21 is formed. A fitting part 22 for sliding fitting with the holding cylinder 20 is formed.

The element holding barrel 20 has a substantially cylindrical shape, and has a female screw 23 screwed with a male screw 21 of the lens barrel 14 and a fitting portion 22 of the lens barrel 14 on the inner surface on the distal end side. It has a fitting surface 24 for dynamic fitting, and a screw relief portion 25 is formed between the female screw 21 and the fitting surface 24 over the entire circumference. Further, the last objective lens 15d of the objective lens system 12 is hermetically attached and fixed to the inner surface on the rear end side of the element holding cylinder 20, and the solid-state image sensor 13 is attached to the final objective lens 15d via a cover glass 26. It is fixed with an optical adhesive. The final objective lens 15d of the objective lens system 12, the cover glass 26, and the solid-state imaging device 13
It is adhesively fixed while being positioned with respect to the optical axis. Further, the final objective lens 15d can be directly adhered and fixed to the solid-state imaging device 13 by eliminating the cover glass 26. Further, on the outer peripheral front surface of the cover glass 26 adhered and fixed to the solid-state imaging device 13,
An adhesive 37 is used to prevent the adhesive fixed surface of the solid-state imaging device 13 and the cover glass 26 from peeling off and to secure airtightness of the adhesive fixed surface.
Is applied.

The fitting portion 22 of the lens barrel 14 is slidably fitted on the fitting surface 24 of the element holding barrel 20. Further, the male screw 21 of the lens barrel 14 and the female screw 23 of the element holding barrel 20 The lens barrel 14 advances and retreats in the direction of the optical axis by rotating the lens barrel 14 and rotates, and the subject light captured by the objective lenses 15a to 15c arranged in the lens barrel 14 is coupled to the solid-state imaging device 13. The focus of the subject formed on the image plane is adjusted. After the focus adjustment is completed, for example, a silicone-based elastic adhesive 16 is applied air-tight to the entire circumference of the distal end side of the male screw 21 of the lens barrel 14 and cured, and then fitted and fixed to the distal end component main body 4. .

The fitting length L1 of the fitting portion 22 of the lens barrel 14 and the fitting surface 24 of the element holding barrel 20 is determined by the male screw 21 of the lens barrel 14 and the female screw 23 of the element holding barrel 20. It is longer than the combined length L2 (L1> L2). Also,
The length of the male screw 21 of the lens barrel 14 is
At the time of focus adjustment, which will be described later, when the subject light captured in step 2 is formed on the imaging surface of the solid-state imaging device 13, a minimum adjustment pitch obtained by adding the length of approximately two threads as a thread pitch of a necessary adjustment allowance. Length, and the thread pitch is
Is set clockwise (or counterclockwise) to a dimension that allows focus adjustment by making one full rotation.

Note that there is a space between the outer peripheral surface of the element holding cylinder 20 and the inner peripheral surface of the distal end component main body 4 so that they are not fitted.

Various electronic components 27 are mounted on the back side of the solid-state imaging device 13 to supply a drive signal to the solid-state imaging device 13 and to form an electric circuit for transmitting and processing an electric signal of a subject image. A wiring board 28 is disposed and fixed, and external leads 2 extending from the side surface of the solid-state imaging device 13 to lands (not shown) provided on the side surface of the printed wiring board 28.
9 is bent in the shape of a crank and then connected and connected with solder.

The lands on the side surfaces of the printed wiring board 28, together with the external leads 29 of the solid-state imaging device 13, are inserted into the bending portion 3 to control the operation of the solid-state imaging device 13 (not shown). And various signal lines 31 of a cable 30 connected to a television monitor that receives and reproduces an electric signal of a captured subject light.

A cable holding member 32 is mechanically fixed to the outer periphery of the distal end of the cable 30 by bonding or caulking, and a step is provided on the inner surface of the cable holding member 32. In order to electrically insulate the shield wire 33 exposed at the end of the shield wire 30 and prevent the shield wire 33 from being unraveled, a thread winding portion 34 wound and fixed with an insulating thread is disposed.
The cable 30 is caught by the stepped portion 2 and is formed to prevent the cable 30 from coming off the cable holding member 32.

The solid-state imaging device 13 and the printed wiring board 2
8 and the outside of the signal line 31 are surrounded by a shield frame 35 formed of a thin metal plate, and the outer peripheral surfaces of the shield frame 35, the element holding cylinder 20 and the cable holding member 32 are heat-shrinkable tubes 36. Cover with. The interior space of the solid-state imaging device 13, the printed wiring board 28, and the signal line 31 covered with the heat-shrinkable tube 36 is filled with, for example, an epoxy-based adhesive to maintain confidentiality.
The arrangement positions of the printed wiring board 28 and the signal lines 31 are maintained.

The objective lenses 15a to 15c are provided in front of the final objective lens 15d of the objective lens system 12.
A field-of-view mask 38 for setting the viewing angle of a subject to be captured and projected on the image-forming surface of the solid-state imaging device 13 is arranged. Further, an aperture mechanism 39 is arranged between the objective lenses 15a and 15b. Have been. The state in which the lens barrel 14 and the element holding barrel 20 have been assembled in a predetermined positional relationship is referred to as an imaging unit 40.

Next, an assembling method and an assembling sequence of the above-described imaging unit 40 will be described.

The printed circuit board 28 has electronic components 27
And peeling the outer skin of the distal end portion of the cable 30, connecting and arranging the signal line 31 at a predetermined connection position on the printed wiring board 28 by soldering or the like. External lead 29 of imaging element 13
Is bent and connected to the printed wiring board 28 by wiring. The bobbin winding portion 34 of the shield wire 33 at the portion where the outer skin of the cable 30 is peeled is subjected to bobbin winding, and the previously held cable holding member 32 is returned to the bobbin winding portion 34 of the cable 30 and adhered and fixed. The solid-state imaging device 13 connected to the printed wiring board 28 is bonded to the final objective lens 15 d via a cover glass 26 with an optical adhesive, and is bonded to the outer peripheral side surface of the solid-state imaging device 13 and the cover glass 26. Apply agent 37 and seal. Further, a shield plate 35 is disposed around the cover glass 26, the solid-state imaging device 13, the printed wiring board 28, and the cable holding member 32, and an epoxy resin adhesive is filled and solidified inside the shield slope 35. Apply confidentiality. The final objective lens 1 is placed on a field mask 38 previously set in the element holding cylinder 20.
5 d is hermetically bonded, and the cable holding member 32 is covered from the element holding tube 20 with a heat shrinkable tube 36.

On the other hand, the plurality of objective lenses 15a to 15c and the aperture mechanism 39 are mounted and fixed to the lens barrel 14 in advance. The fitting portion 22 of the lens barrel 14 is fitted from the front side of the element holding barrel 20 and is fitted and slid on the fitting surface 24, and the male screw 21 of the lens barrel 14 and the While screwing the female screw 23, the lens barrel 14 is rotationally screwed into the element holding barrel 20, and the objective lenses 15a to 15c in the lens barrel 14 are screwed.
The focus of the objective lens system 12 and the solid-state imaging device 13 are aligned. When the focus adjustment between the objective lens system 12 and the solid-state imaging device 13 is completed, an elastic adhesive 16 is applied to the entire circumference of the distal end side of the male screw 21 and the female screw 23 to maintain confidentiality, and By removing the elastic adhesive 16, the lens barrel 14 can be detached from the element holding barrel 20. Further, since the fitting portion 22 of the lens barrel 14 and the fitting surface 24 of the element holding barrel 20 are slidably fitted, the entry of dust can be prevented.

After the lens barrel 14 and the element holding barrel 20 have been assembled in this manner, and the focus position has been adjusted, the imaging unit 40 is assembled into the observation window 10 of the tip component main body 4 and the tip cover 5 A positioning screw 18 provided on the outer periphery of the lens barrel 14 is fitted and fixed in a groove 19 of the lens barrel 14, and a portion where the distal end portion of the lens barrel 14 contacts the distal end component main body 4 and the distal end cover 5 includes:
Apply an elastic adhesive to provide airtightness.

As a result, the objective lens 15a in which the lens barrel 14 is disposed is securely attached and fixed to the observation window 10 of the main body 4 and the predetermined position of the front cover 5.

After the imaging unit 40 has been assembled in the distal end component main body 4 in this way, the fixed piece 7 is attached to the distal end component main body 4, and the entire outer periphery of the distal end component main body 4 is covered with the outer skin 8. The tip 2 is completed by coating.

Next, the lens barrel 14 of the endoscope tip 2
The procedure at the time of replacement will be described. Basically, the order is reverse to that of the above-described assembling.

First, the outer cover 8 is removed, the fixing piece 7 is removed from the main body 4, and the positioning screw 18 fitted in the groove 19 of the lens barrel 14 from the outer periphery of the front cover 5 is loosened. The imaging unit 40 is removed from the distal end component main body 4. The tip cover 5
It is clear that the elastic adhesive applied to the contact surface between the observation window 10 and the lens barrel 14 and the elastic adhesive 16 applied to the positioning screw 18 are removed.

After removing the elastic adhesive applied to the male screw 21 of the lens barrel 14 and the female screw 23 of the element holding barrel 20, the imaging unit 40 removed from the distal end component body 4 is removed. The screwing of the male screw 21 of the lens barrel 14 and the female screw 23 of the element holding barrel 20 is released. The element holding tube 2 removed from the lens tube 14
After cleaning the female screw 23, the fitting surface 24, the visual field mask 38, and the final objective lens 15d, a newly prepared lens barrel 14 is prepared, and reassembled according to the above-described assembling order.

In the endoscope end portion having such a configuration,
The lens barrel 14 is provided with a fitting portion 22 at a portion fitted to the solid-state imaging device 13 side of the element holding barrel 20, and a male screw 21 is formed at a front side of the fitting portion 22. On the other hand, a female screw 23 is provided at a distal end portion of the element holding tube 20 where the lens tube 14 is inserted and fitted, and the female screw 23 and the final objective lens 1 arranged in the element holding tube 20 are provided.
5d, a fitting surface 24 is formed, and dust adhered to the male screw 21 or the female screw 23 due to the fitting of the fitting portion 22 and the fitting surface 24 being slid, Fitting part 2
2 does not enter the lens barrel 14 and the element holding tube 20 because of being blocked by the fitting surface 24. Further, a screw is provided between the female screw 23 of the element holding tube 20 and the fitting surface 24. Since the escape portion 25 is provided, dust is temporarily attached to the male screw 21 or the female screw 23, or the thread of the male screw 21 or the female screw 23 is broken for some reason and the broken piece is damaged. However, the dust and broken pieces accumulate in the screw escape portion 25 and do not enter the lens barrel 14 or the element holding barrel 20.

The optical axes of the objective lens group 12 disposed in the lens barrel 14 and the solid-state image pickup device 13 disposed in the element holding barrel 20 are aligned with the fitting portion 22 of the lens barrel 14 and the element. Since the fitting surface 24 of the holding cylinder 20 is slidably fitted tightly, the holding cylinder 20 can be assembled with almost no adjustment, and the focus adjustment between the objective lens group 12 and the solid-state imaging device 13 can be performed by adjusting the lens cylinder 14 It can be easily adjusted only by screwing and rotating the screw 21 and the female screw 23. Even if the optical performance of the objective lens 15 in the lens barrel 14 to be newly replaced varies,
And at least two threads of female screw 23 are screwed together, and
By setting the fitting length L1 of the fitting portion 22 and the fitting surface 24 to be longer than the screwing length L2 of the two screws 21 and 23, the lens barrel 14 and the element holding member are held. The sufficient fixing strength of the cylinder 20 can be secured.
A screw or the like for fixing and holding the lens barrel 14 and the element holding barrel 20 is not required, and the diameter of the connecting portion between the lens barrel 14 and the element holding barrel 20 can be reduced.

Further, for fixing the image pickup unit 40 to the distal end component main body 4, a screw 18 is fitted and fixed to the groove 19 of the lens barrel 14 from outside the distal end cover 5 of the distal end component main body 4. Therefore, the fixing of the lens barrel 14 arranged on the observation window 10 is at a predetermined position,
The lens barrel 14 does not protrude or retract from the distal end surface 9 of the lens unit, and is attached to the distal end component body 4 in a state where the lens barrel 14 of the imaging unit 40 and the element holding barrel 20 are maintained in a pre-assembled state. Since the objective lens group 12 and the solid-state imaging device 13 are fixed, they can be assembled without affecting the optical axis and the focus of the objective lens group 12 and the solid-state imaging device 13.

Next, the relationship between the printed wiring board on which the electric circuit element for driving and controlling the solid-state imaging device of the endoscope of the present invention is mounted and the cable will be described with reference to FIG. In addition,
1 are given the same reference numerals and the detailed description is omitted.

The distal end portion 2 of the endoscope is desired to be as small as possible in outer diameter and as short as possible in order to be inserted into a body cavity. The external leads 2 of the solid-state imaging device 13
9 is connected to a printed wiring board 28 on which electronic components constituting an electric circuit for controlling electric signals of the solid-state imaging device 13 are mounted. Shortening is also desired. For this reason, conventionally, a signal line 31 derived from the end of the cable 30 is used.
Is shortened as much as possible, but the work efficiency at the time of attaching and soldering the signal line 31 to the printed wiring board 28 is reduced.

Therefore, according to the present invention, as shown in FIG. 2A, the signal line 31 led out from the end of the cable 30 is
The connection lands provided on the side surfaces of the printed wiring board 28 are set to have a length having a dimension that allows easy wiring connection work, and the connection lands of the printed wiring board 28 are Is connected by soldering. Next, as shown in FIG. 2B, the cable 30 is twisted several times, and the signal line 31 is twisted a plurality of times into a stranded state. In this state, the cover glass 26, the solid-state imaging device 13,
An electronic component 27, a printed wiring board 28, and a shield frame 35 for shielding the signal line 31 are mounted, and the cover glass 26, the solid-state image sensor 13, the electronic component 27, and the printed wiring are covered by the shield frame 25. The entire area up to the substrate 28, the signal line 31, and the cable holding member 32 is filled with an epoxy resin adhesive and solidified, and then covered with a heat shrinkable tube 36. Wiring and assembly of the substrate 28 and the cable 30 are performed.

As a result, it is possible to secure a line length for facilitating the operation of connecting and wiring the signal line 31 to the printed wiring board 28, and twist and twist the signal line 31 after connecting and wiring the printed wiring board 28. With the linear shape, the entire length of the signal line 31 between the printed wiring board 28 and the stripped portion of the cable 30 can be shortened, and the signal line 31 can be reduced.
The twisted wire portion enhances the strength against bending and pulling.

Next, the solid-state image pickup device 28 of the endoscope of the present invention will be described.
External leads 29 are connected, and various electronic components 27
The configuration of the printed wiring board 28 on which is mounted will be described with reference to FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description will be omitted.

A plurality of external leads 29 extending from the solid-state imaging device 13 are formed in the same shape from the outer surface of the solid-state imaging device 13 at equal intervals. On the other hand, the plurality of signal lines 31 built in the cable 30 are
The conductor diameter of the signal line 31 varies depending on the signal content or power handled by the signal line 1. The shapes and sizes of the plurality of electronic components 27 mounted on the printed wiring board 28 are different from each other. For this reason, the external leads 29 of the solid-state imaging device 13 arranged on the printed wiring board 28 and the cable 3
0, the position of the connection land of the signal line 31 and the electronic component 2
We have difficulty in the location of 7.

Accordingly, the printed wiring board 2 of the endoscope of the present invention
8, as shown in the cross section AA of FIG. 3A, wiring lands 29 ′ of the external leads 29 of the solid-state imaging device 13 are formed on both opposing side surfaces of the printed wiring board 28, Lands 41 to 43 of various shapes on which the signal lines 31 of the cable 30 are wired are formed on both side surfaces. In particular, the connection lands of the signal line 31 of the cable 30 include a land 41 for a thick wire having a conductor diameter, a land 42 for a middle wire having a conductor diameter, and a land 43 for a wire having a small conductor diameter. The land 41 for a thick line or the land 42 for a middle line is arranged at the corner of the printed wiring board 28, and the land 43 for the thin line is arranged between the lands 41, 42 for the thick line or the middle line. It is formed as follows.

As shown in FIG. 3B, the cable 30 is connected to the same land as the connection land 29 'of the external lead 29 provided on the opposite side surface of the printed wiring board 28.
Lands of the signal lines 31 and the printed wiring board 28
Are formed so that the lands 41 for thick lines are arranged at the corners of the circles, and the lands 42 and 43 for medium lines and thin lines are arranged between the rounds 41 for thick lines.

As described above, the connecting lands 29 ′ and 41 for the external leads 29 and the signal lines 31 are provided on the outer surface of the printed wiring board 28.
By arranging 43, the connection soldering work becomes easy, and a large mounting area for the electronic component 27 mounted on the printed wiring board 28 can be secured.

Next, a modified example of the printed wiring board 28 will be described with reference to FIGS. The same parts as those in FIG. 3 are denoted by the same reference numerals, and detailed description is omitted.

FIG. 4 shows that the printed wiring board 28 is divided into two parts, one printed wiring board 28 has electronic components 27 arranged on both sides, and the other printed wiring board 28 ′ has The signal line 31 is mainly connected. Electronic components 27 are arranged on both sides of the printed wiring board 28, and external leads 29 extending from the solid-state imaging device 13 are connected to opposing side faces of the printed wiring board 28, The external leads 29 are further connected to the printed wiring board 2.
8 'is extended and connected to both opposing side surfaces.
The printed wiring board 28 'is provided with a side surface to which the external lead 29 is connected and a land 31' to which a signal line 31 of the cable 31 is connected in a plane portion. A cutout portion 44 is formed on a side surface of the printed wiring board 28, 28 'to which the external lead 29 is not connected.
4, a reinforcing plate 45 is fitted over the printed wiring boards 28 and 28 ', and the front end surface of the reinforcing plate 45 is fixed to the solid-state imaging device 13 by adhesion. That is, the reinforcing plate 45 is used to maintain the distance between the solid-state imaging device 13 and the printed wiring boards 28 and 28 ′ at a predetermined size and to fix and maintain the printed wiring boards 28 and 28 ′. Further, the printed wiring boards 28, 28 '
Is formed with at least one or more through-holes 46 in the plane portion thereof.

FIG. 5 shows a printed circuit board in which the electronic component 27 is mounted on both sides of a single printed wiring board 28, and the external leads 29 and the signal lines 31 are connected to the same land on opposing side surfaces. In the wiring board 28, the external leads 2
Notch portions 44 are provided on both side surfaces where the signal line 9 and the signal line 31 are not connected, and a reinforcing plate 45 is disposed in the notch portion 44. Have been. Further, the printed wiring board 2
8, a through hole 46 is formed.

Further, FIG. 6 shows that the reinforcing plate 45 is directly attached and fixed without providing the cutouts 44 on both sides of the printed wiring board 28 to which the external leads 29 are not connected, and
The other end of the reinforcing plate 45 is extended and fixed to the outer peripheral portion of the element holding cylinder 20. As shown in FIG. 6, the reinforcing plate 45 is formed of a metal material to fix the reinforcing plate 45 to the printed wiring board 28.
8 is fixed to the side surface of the printed wiring board 28 by soldering or adhesive, or the end of the reinforcing plate 45 'is bent to one flat surface side of the printed wiring board 28 and fixed by soldering or adhesive. or,
An adhesive is used to fix the reinforcing plates 45 and 45 'to the element holding tube 20.

By arranging the reinforcing plates 45 and 45 'in the cutouts 44 provided in the printed wiring board 28 or 28', the solid-state image pickup device 13 and the printed wiring boards 28 and 2 'are arranged.
8 ', and the fixed holding strength of the printed wiring board 28 or 28' against the vibration and impact of the endoscope end portion 2 can be enhanced. Further, the reinforcing plates 45, 45 '
May be formed of an object having a material capable of maintaining the fixed holding of the printed wiring board.
Is formed of a metal material, the shield frame 35 can be omitted, or the shield effect can be further improved by using the shield frame 35 in common. In addition, when the adhesive is filled between the printed wiring board 28 or 28 ′ and the solid-state imaging device 13 or the like, the through-hole 46 easily flows around through the through-hole 46, and the printed wiring board 28 The periphery of the mounted electronic component 27 can be reliably filled with the adhesive. The internal strength of the imaging unit 40 is improved by filling the adhesive.

It is clear that the shape and number of the reinforcing plates 45, 45 'can be set to a shape and number that can achieve the purpose of the reinforcing plates 45, 45.

Next, another embodiment of a printed wiring board on which an electric circuit element for driving and controlling a solid-state imaging device of an endoscope according to the present invention will be described with reference to FIGS. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.

When the printed wiring board 28 is disposed behind the solid-state imaging device 13, the reinforcing plate 45 shown in FIGS. In the above-mentioned Japanese Patent Application Laid-Open No. 61-59309, it is disclosed that a spacer is interposed between the first printed board and the second printed board. The reinforcing plate 45 and the spacer may hinder a reduction in the diameter and length of the connection between the solid-state imaging device of the endoscope and the printed wiring board.

FIG. 7 shows an electronic component-mounted printed wiring board 28 in which electronic components are mounted on both sides of a printed wiring board disposed behind the solid-state imaging device 13 and a cable connection in which the signal line 31 of the cable 30 is connected. The printed wiring board 51 is mainly provided. For example, a resistor 47 and a transistor 48
Are mounted on one and the same front surface, and the IC 49 and the capacitor 50 are mounted on the other and the same back surface. The resistor 47
The outer height H1 of the transistor 48 and the outer height H2 of the transistor 48 are almost the same (H1ＨH2), and the outer height H3 of the IC 49 and the outer height H4 of the capacitor 50 are almost the same (H3 ≒ H4). ) Is used. That is, electronic components mounted on the front surface and the back surface of the printed wiring board 28 are selected and arranged with substantially the same height.
The electronic component mounting printed wiring board 28 and the cable connection printed wiring board 51 are disposed behind the solid-state imaging device 13, and the solid-state imaging device 13 The external lead 29 is connected, but the resistor 47 mounted on the front surface of the electronic component mounting printed wiring board 28 and the head of the transistor 48 are arranged on the back surface of the solid-state imaging device 13 so as to be in contact with each other. The surface of the connection printed wiring board 51 where the signal line 31 of the cable 30 is not introduced and connected is connected to the electronic component mounted printed wiring board 2.
8 and the IC 49 on the back side and the head of the capacitor 50 are disposed in contact with each other. That is, the arrangement interval H5 between the solid-state imaging device 13 and the electronic component-mounted printed wiring board 28 is determined by the height H1 of the resistor 47 and the height H2 of the transistor 48.
Can be arranged with almost the same dimensions as (H1 ≒ H2 ≒ H5).
An arrangement interval H6 between the electronic component mounting printed wiring board 28 and the cable connection printed wiring board 51 can be set to be substantially the same as the height H3 of the IC 49 and the height H4 of the capacitor 50 (H3 ≒ H4 ≒ H6). .

As a result, the interval between the various printed wiring boards 28 and 51 disposed behind the solid-state imaging device 13 is
The electronic component mounted on the printed wiring board can be set by selecting substantially the same external height without using any spacing maintaining reinforcing plate or spacer.

Next, an application example of the other embodiment will be described with reference to FIG. The same parts as those in FIG. 7 are denoted by the same reference numerals, and detailed description is omitted.

This application example is a case where some electronic components are mounted on the printed wiring board 51 for cable connection in view of the circuit network formed on the printed wiring boards 28 and 51. The back surface of the connection connection surface of the signal line 31 of the cable 30 of the cable connection printed wiring board 51,
That is, it was mounted on the surface facing the electronic component mounted printed wiring board 28. As a result, the arrangement interval H6 between the electronic component mounting printed wiring board 28 and the cable connection printed wiring board 51 is determined by the height H3 of the IC 49 and the capacitor 50.
Of the same dimensions (H3 ≒ H4 ≒ H) set at a height H4
6) can be arranged.

In the description of the other embodiments,
Although the height dimensions of the electronic components mounted on each surface of the electronic component mounting printed wiring board 28 are set to be substantially the same, the height dimensions of all the electronic components mounted on the printed wiring board need not be the same, Among the electronic components to be mounted, select the electronic components having the same dimensions and the highest and largest of several points, and set the arrangement interval of the printed electronic circuit boards to the selected electronic components having the large height. By arranging the solid-state imaging device and the printed wiring board at the most appropriate position on the printed wiring board, the mounting arrangement interval and position between the solid-state imaging device and the printed wiring board can be determined.

[Appendix] (Appendix 1) In an endoscope having an image pickup unit including a plurality of objective lenses for picking up an image of a subject and a solid-state image pickup device for converting a subject image picked up by the objective lens into an electric signal, A lens barrel having an objective lens held in an inner peripheral portion, a male screw portion and a fitting portion formed in an outer peripheral portion, and the solid-state imaging device held in an inner peripheral portion, and an imaging surface side of the solid-state imaging device. A female screw part formed on the inner peripheral part of the element holder and an element holding cylinder having a fitting part. Wherein the male screw portion of the solid-state imaging device and the female screw portion of the element holding cylinder are screwed together, and an image pickup unit that adjusts the solid-state imaging device and the objective lens in the optical axis direction by this screwing dimension is provided. mirror.

(Additional Item 2) The screw length of the male screw portion formed on the outer peripheral portion of the lens barrel is obtained by adding the length of two screw threads to the screw thread pitch required for adjusting the focus of the objective lens. The endoscope according to claim 1, characterized in that the endoscope has dimensions.

(Additional Item 3) The fitting length of the fitting portion formed with the lens barrel and the element holding barrel is longer than the screwing length of both screw portions of the lens barrel and the element holding barrel. 3. The endoscope according to claim 1, wherein

(Additional Item 4) In an endoscope having an image pickup unit including a plurality of objective lenses for picking up an image of a subject and a solid-state image pickup device for converting a subject image picked up by the objective lens into an electric signal, An electronic circuit for processing the drive signal of the solid-state imaging device and the electric signal of the converted subject image is disposed at the rear, and further, a signal cable for transmitting and receiving various signals and a drive source is connected to a single or An electronic component comprising a plurality of printed wiring boards and various electronic components constituting an electronic circuit of the printed wiring board, wherein the electronic components mounted on the printed wiring board have substantially the same height and shape. An endoscope wherein components are mounted on the same surface of the printed wiring board.

(Supplementary note 5) The single or plural printed wiring boards arranged behind the solid-state imaging element may be arranged at intervals between the solid-state imaging element and the printed wiring board, or may be arranged between the solid-state imaging element and the plural printed wiring boards. 5. The endoscope according to claim 4, wherein the mutual arrangement interval is substantially the same as the height and dimension of the electronic component mounted on the printed wiring board.

(Additional Item 6) An electronic device according to Additional Item 4, wherein at least a plurality of electronic components among the electronic components mounted on the same surface of the printed wiring board have the same maximum height and shape. Endoscope.

[0065]

According to the present invention, the end portion of the endoscope has a lens barrel for holding the objective lens constituting the imaging unit, and a device holding cylinder for holding the solid-state imaging device having a screw portion and a fitting portion. Accordingly, the diameter of the lens barrel and the element holding cylinder can be reduced, and the optical axis of the lens barrel and the element holding cylinder are displaced during the assembly of the imaging unit or the replacement of the lens barrel when the objective lens is damaged. In addition, focus adjustment can be easily and reliably performed, and since dust does not easily enter between the lens barrel and the element holding barrel, a skilled operation is not required at the time of assembly or replacement.

Further, when the lens barrel is replaced, even if the coupling position between the lens barrel and the element holding barrel is shifted due to focus adjustment due to the variation in the optical characteristics of the objective lens, the surface of the distal end main body remains. The distal end portion of the lens barrel located can be reliably fixed at a predetermined position.

Therefore, the endoscope according to the present invention has an effect that the image pickup unit can be assembled and the image pickup unit can be repaired without using a special work environment and skilled work.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view showing a connection arrangement between a solid-state imaging device arranged at a distal end portion of the endoscope shown in FIG. 1, a printed wiring board and a cable.

FIG. 3 is a sectional view showing a configuration of a printed wiring board arranged at a distal end portion of the endoscope shown in FIG. 1;

FIG. 4 is a sectional view showing an application example of the printed wiring board shown in FIG. 3;

FIG. 5 is a sectional view showing an application example of the printed wiring board shown in FIG. 3;

FIG. 6 is a sectional view showing an application example of the printed wiring board shown in FIG. 3;

FIG. 7 is a cross-sectional view of another embodiment of the connection arrangement between the solid-state imaging device arranged at the distal end of the endoscope shown in FIG. 1, the printed wiring board, and the cable.

FIG. 8 is a cross-sectional view showing a modification of the connection arrangement between the solid-state imaging device arranged at the distal end of the endoscope shown in FIG. 7, the printed wiring board, and the cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Insertion part 2 ... Tip part 3 ... Bending part 4 ... Tip construction part main body 5 ... Tip cover 6 ... Movable piece 7 ... Fixed piece 8 ... Outer skin 9 ... Tip face 10 ... Observation window 11 ... Suction port 12 ... Objective lens system DESCRIPTION OF SYMBOLS 13 ... Solid-state image sensor 14 ... Lens cylinder 15a-15c ... Objective lens 15d ... Final objective lens 16 ... Elastic adhesive 17 ... Stepped part 18 ... Positioning screw 19 ... Groove 20 ... Element holding cylinder 21 ... Male screw 22 ... Fitting part 23 ... female screw 24 ... fitting surface 25 ... screw escape part 26 ... cover glass 27 ... electronic component 28 ... printed wiring board 29 ... external lead 30 ... cable 31 ... signal line 32 ... cable holding member 33 ... shield wire 34 ... thread winding Part 35 ... Shield frame 36 ... Heat shrink tube 37 ... Adhesive 38 ... Field mask 39 ... Aperture mechanism 40 ... Imaging unit 41 ... Thick line land 42 ... Medium line land 43 ... Fine Wire land 44 Notch 45 Reinforcement plate 46 Through hole 47 Resistor 48 Transistor 49 IC 50 Capacitor 51 Cable printed wiring board

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/225 H04N 5/225 D

Claims (1)

[Claims] 1. An endoscope having an imaging unit including a plurality of objective lenses for imaging a subject and a solid-state imaging device for converting a subject image captured by the objective lens into an electric signal. And a lens barrel having a male screw portion and a fitting portion formed on the outer peripheral portion, and the solid-state imaging device is retained on the inner peripheral portion and formed on the inner peripheral portion on the imaging surface side of the solid-state imaging device. An element holding cylinder having a female screw part and a fitting part, wherein both fitting parts of the lens barrel and the element holding cylinder are slidably fitted, and a male screw part of the lens barrel and the An endoscope having an image pickup unit in which a female screw portion of an element holding cylinder is screwed, and the screwing dimension is used to adjust the solid-state image pickup element and the objective lens in the optical axis direction.