JPH1123980A - Image pickup unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup unit allowing a fine focus adjustment of an image pickup optical system and also having a sufficient intensity. SOLUTION: In an objective optical system of an image pickup unit 12, a lens frame 23 fixedly holding a 1st lens 14 and 2nd lens 15, and a SID frame 24 forming a step on the periphery and fixedly holding a 3rd lens, a 4th lens 17, and a solid-state imaging device (SID) 18 are fitted with each other via an insulation frame 27, and between a rear end of the lens frame 23 and the step part of the SID frame 24, inclusion 28 consisting of adhesive, spacer, etc., are provided. Each dimension of a surface where the lens frame 23 and the SID frame 24 face each other is designed so that an inner diameter of the rear end part of the lens frame 23 is larger than a 1st outer diameter of the tip part of the SID frame 24, and an outer diameter of the rear end part of the lens frame 23 is equal to or smaller than a 2nd outer diameter of the rear end of the step part of the SID frame 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device which is incorporated in a distal end portion of an insertion portion of an endoscope.

[0002]

2. Description of the Related Art Conventionally, endoscopes capable of observing a test site and performing various treatments by inserting an elongated insertion portion into a body cavity or the like have been widely used. In particular, in recent years, a solid-state imaging device including an objective lens, a CCD, etc.
Various electronic endoscopes including an imaging unit including a circuit board and the like connected to a solid-state imaging device have been proposed.

As an image pickup unit, for example,
As disclosed in Japanese Patent Application Laid-Open No. 60972, a structure in which a lens frame and a CCD frame are fitted and the lens frame and the CCD frame are fixed to each other by an adhesive force,
As disclosed in US Pat. No. 2,269,081, there is a structure in which a lens frame and a CCD frame are integrated.

[0004]

When the imaging unit as described above is taken out of the end portion of the insertion portion of the endoscope or the like for repair, the lens and the lens frame are generally pushed and removed from the installation site. It has become. At this time, in the conventional structure as disclosed in Japanese Patent Publication No. 6-60972, there is a risk that the adhesive fixing the lens frame and the CCD frame may be peeled off, and the structure may be easily broken. Further, in the structure as disclosed in Japanese Patent Application Laid-Open No. H5-269081, since the lens frame and the CCD frame are integrated, the problem that the lens frame and the CCD frame are easily damaged when detached from the disposition portion can be solved. However, there is a problem that the focus becomes loose because the focus cannot be finely adjusted because it is determined uniformly.

The present invention has been made in view of the above circumstances, and enables fine adjustment of the focus of an imaging optical system.
It is an object to provide an imaging device having a sufficient strength.

[0006]

According to the present invention, there is provided an image pickup apparatus comprising: a lens of an objective optical system for forming an image of a subject; a lens frame for holding at least one of the lenses of the objective optical system; A solid-state imaging device arranged behind and captures a subject image, and an imaging device including an imaging device frame that holds the solid-state imaging device, wherein the imaging device frame,
A step portion is formed on the outer periphery of the lens frame, the tip portion having a first outer diameter, and a rear end side having a second outer diameter larger than the first outer diameter; Is characterized by having an inner diameter larger than a first outer diameter of the imaging element frame and an outer diameter equal to or smaller than a second outer diameter of the imaging element frame at a rear end thereof.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 relate to a first embodiment of the present invention. FIG. 1 is a cross-sectional view showing a configuration of a distal end portion of an insertion section of an endoscope incorporating an imaging device, and FIG.
FIG. 3 is an explanatory view showing a system configuration of the endoscope apparatus, FIG. 4 is a cross-sectional view showing a configuration of a signal cable, and FIG. 5 is a block diagram showing a configuration of a disconnection detecting unit. FIG. 6 is an explanatory diagram showing a first configuration example of a connection portion between the connector of the universal cord and the video processor, and FIG. 7 is an explanatory diagram showing a second configuration example of a connection portion between the connector of the universal cord and the video processor. It is.

As shown in FIG. 3, an endoscope 1 provided with an imaging device according to the present embodiment has an elongated insertion portion 2 that can be inserted into a body cavity or the like. 3, a bendable portion 4 and a flexible tube portion 5 having flexibility are provided. On the rear end side of the insertion section 2, an operation section 6 also serving as a grip section
Are provided continuously, and a signal cable,
A universal cord 7 in which a light guide fiber or the like is provided extends. The universal cord 7 is connected to a video processor 9 via a connector 8 provided at the end. The video processor 9 is connected to a monitor 11 via a signal cable 10. An image signal of a subject imaged by an imaging unit provided at the distal end portion 3, which will be described later, is subjected to signal processing by the video processor 9, and the subject image is monitored. 11 is displayed.

As shown in FIG. 1, an imaging unit 12 is provided at the distal end portion 3 of the endoscope 1 and is fixed to a distal end support frame 13. The imaging unit 12 includes a first lens 14, a second lens 15,
It has a third lens 16 and a fourth lens 17, and a solid-state imaging device (SID) 18 is arranged behind the fourth lens 17.

A first diaphragm 19, a spacer 20 having a lower specific heat than a lens having a rough surface, and a second lens 15 are fitted around the inner periphery of the first lens 14. The two lenses 15 are hermetically fixed with an adhesive. At this time, the air pressure in the space 21 surrounded by the first lens 14 and the second lens 15 is 1.2 to 10 atm (atmospheric pressure). The inner surfaces of the first lens 14 and the second lens 15 are provided with a water-repellent coating 22.

The first lens 14 is fitted and held in the lens frame 23. On the other hand, the third lens 16, the fourth lens
The lens 17 and the solid-state imaging device 18 are fitted and held in an SID frame 24 having a step formed on the outer periphery. Also,
A second diaphragm 25 is provided on the front surface of the third lens 16, and a spacer 26 is provided between the third lens 16 and the fourth lens 17.
Is inserted. The inner periphery of the rear end of the lens frame 23 and the outer periphery of the front end of the SID frame 24 are fitted via a tubular insulating frame 27. Also, the rear end of the lens frame 23 and SI
Between the step portion of the D frame 24, an intervening body 28 made of an adhesive, a spacer, or the like is provided.

As shown in FIG. 2, the dimension of the surface where the lens frame 23 and the SID frame 24 face each other is as follows: (inner diameter a of the lens frame 23)> (first outer diameter c of the SID frame 24). 23 is satisfied (the second outer diameter d of the SID frame 24). That is, the inner diameter a at the rear end of the lens frame 23 is larger than the first outer diameter c at the front end of the SID frame 24, and the outer diameter b at the rear end of the lens frame 23 is Each dimension is set to be equal to or smaller than the second outer diameter d on the rear end side.

The solid-state image sensor 18 has an SI extending rearward.
It has a D lead 29, and a circuit board 30 is connected to the SID lead 29. An electric component 32 such as an IC having a hole 31 is attached to the circuit board 30, and the electric component 32 is covered with a sealing resin 33 having a close thermal expansion coefficient to the circuit board 30 and good heat radiation.

The signal cable 34 is soldered and connected to the circuit board 30 in a state where the end of the signal cable 34 is wound around the electric component 32. The signal cable 34 is 180 ° as shown in FIG.
It may be in a rotated state, and is not limited to this. For example, 270
° may be turned.

As described above, in the connection portion of the signal cable 34 to the circuit board 30, the signal cable 34 is pulled by the bending of the insertion portion 2 by connecting the end portion of the signal cable 34 with a slack. Since the tensile stress can be absorbed by the slack portion, the signal cable 34 is less likely to be disconnected. Therefore, according to this configuration, disconnection of the signal cable can be prevented, and durability is improved.

A shield frame 35 for covering the solid-state imaging device 18 and the circuit board 30 is provided on the outer peripheral portion of the circuit board 30. The shield frame 35 is fixed to the outer peripheral portion on the rear end side of the SID frame 24 by an adhesive. I have. Here, shield frame 3
Reference numeral 5 denotes a structure in which the distal end of a cable bundle 36 in which the signal cables 34 are gathered and covered is located in a shield frame 35. Further, an adhesive 37 is provided inside the shield frame 35.
Is filled, and the shield frame 35 and the tip of the cable bundle 36 are fixed with an adhesive 37. The outside of the shield frame 35 is covered with a heat-shrinkable tube 38.

The shield frame 35 is made of a hard conductive member such as a metal, and is filled with an adhesive 37 for fixing the tip of the cable bundle 36 only up to the end of the shield frame 35 and extends rearward. Therefore, the hard portion of the imaging unit 12 ends at the end of the shield frame 35, and the hard length is designed to be the shortest. Further, since the distal end of the cable bundle 36 is fixed by the adhesive 37 in the shield frame 35 and only the soft cable bundle 36 extends rearward, the cable is a soft portion exposed from the shield frame 35. Bundle 3
6 has a uniform strength, is less susceptible to stress concentration, and has the effect of being less likely to break. Therefore, according to this configuration, the disconnection of the cable can be prevented without increasing the rigid length of the imaging unit.

The cable bundle 36 is covered with a protective tube 40 provided with a plurality of slits 39, for example, at least at the curved portion 4. Further, although not shown, a slit may be provided also on the jacket of the cable bundle 36. By providing the slit 39 in the protective tube 40 in this manner, when the cable bundle 36 is bent, the protective tube 4
0 so that the cable bundle 36
Of the cable bundle 36 is hardly broken.

As shown in FIG. 4, the signal cable 34 is composed of an insulated wire 41 (shown by hatching in the lower right in the figure) and an uninsulated wire 42 (shown by hatching in the upper right in the figure). (Shown) at the center as a component. The outer periphery of the inner conductor 43 is covered with an inner insulator 44, an outer conductor 45 is provided outside the inner insulator 44, and the outer periphery of the outer conductor 45 is covered with an outer insulator 46.

Since the inner conductor 43 of the signal cable 34 is soldered to the circuit board 30 at the tip, the wires 41 and 42 are electrically connected at the tip as shown in FIG. FIG.
4 schematically shows the configuration of the disconnection detecting means. The video processor 9 includes a disconnection determination circuit 47 and an alarm circuit 4.
8 are provided, and the wires 41 and 42 are connected to the disconnection determination circuit 47. The disconnection determination circuit 47 measures the resistance value of the wires 41 and 42 and detects a disconnection of the wires 41 or 42 based on a change in the resistance value. When the wire 41 or the wire 42 is disconnected, the disconnection determination circuit 4
7, the detection signal is sent to the alarm circuit 48,
A warning sound or the like is issued from the alarm circuit 48 to notify the user of the occurrence of disconnection.

The inner conductor 43 and the outer conductor 45, which are components of the signal cable 34, are made of materials having different strengths. For example, the inner conductor 43 may be made of a tin-plated tin-containing copper alloy, and the outer conductor 45 may be made of a high tensile strength steel alloy to improve the electrical characteristics of the inner conductor 43 and improve the tensile strength of the outer conductor 45 to prevent disconnection. Configuration. Alternatively, the inner conductor 43 is made of a high tensile strength steel alloy, and the outer conductor 45 is made of a tin-plated tin-containing copper alloy to improve the tensile strength of the inner conductor 43 so that disconnection hardly occurs and improve the electric characteristics of the outer conductor 45. A configuration that enhances the shielding effect may be adopted.

Returning to FIG. 1, the first frame 49 at the front end of the curved frame formed by connecting the first frame 49, the second frame 50,... The outer circumference of the bending piece constituting the bending portion 4 is covered with an outer tube 51, and the distal end of the outer tube 51 is connected to a thread binding portion 52.
It is fixed at. A channel hole 53 is formed through the distal end support frame 13. A front end of the channel hole 53 is opened by a forceps port 54, and a channel pipe 55 is fixed to a rear end. A channel tube 56 is connected to the rear end of the channel pipe 55, and the channel tube 56 extends to the near side via a connecting pipe 57.

Inside the distal end portion 3, first frames 49,
The built-in components made of a hard member such as the curved top such as the second top 50 and the connecting pipe 57 have chamfered corners to form chamfers 58 and 59. Thus, the chamfered part 5
When the insertion section 2 is curved, the image pickup unit 12 can move the first frame 49 and the second frame 5
0, so that it will not be damaged even if it hits the connecting pipe 57 or the like. Although not shown, the operation unit 6 and the connector 8
May be provided with a similar chamfering structure inside to obtain the same effect.

A detaching screw 61 having a claw hole 65 on the distal end surface is screwed and fixed to the imaging unit mounting hole 60 of the distal end support frame 13. The imaging unit 12
The distal end portion of the lens frame 23 is inserted from behind the imaging unit mounting hole 60, and the distal end portion of the lens frame 23 engages with the detachment screw 61 and abuts thereon, and is fixed from the side of the distal end support frame 13 by the fixing screw 62. The space at the head of the fixing screw 62 is filled with an adhesive 63. A watertight ring 64 is provided on the outer peripheral portion of the lens frame 23 so as to engage with the inner peripheral surface of the imaging unit mounting hole 60, and watertightness between the distal end support frame 13 and the lens frame 23 is maintained. ing.

The first lens 14, the second lens 15,
When the third lens 16 and the fourth lens 17 are clouded by water droplets, an ultrasonic oscillator (not shown) is inserted into the forceps port 54, and vibration is given to the imaging unit 12 from the distal end support frame 13, and the first Lens 14, second lens 15, third lens 1
6, the structure is such that water droplets attached to the fourth lens 17 can be removed, and a clear visual field is always secured.

Next, a description will be given of a configuration of a connecting portion between the connector 8 on the rear end side of the universal cord 7 and the video processor 9. As shown in FIG. 6, in the universal cord 7,
A cable bundle 36 of the signal cable 34, a light guide fiber 66 for transmitting illumination light, a gas pipe 67 used for gas sterilization and the like are provided, and an end of the gas pipe 67 is opened by a gas base 68 provided on a side of the connector 8. doing.

In the first configuration example shown in FIG. 6, when the connector 8 and the video processor 9 are connected to each other with the gas mouth cap 68 made of a conductive material such as metal attached to the gas mouth 68 of the connector 8, The two connection detection terminals 70 provided on the outer periphery of the tube 8 are electrically connected by the gas cap 69. The video processor 9 includes:
A connection detection circuit 71 and a power supply circuit 72 are provided,
A connection terminal 73 is provided in the connector receiver 73 at a position corresponding to the connection detection terminal 70, and is connected to the connection detection circuit 71.

When the connector 8 is connected to the connector receiver 73 with the gas cap 68 attached to the gas cap 68, the connection detection terminal 70 comes into contact with the connection terminal 73 and conducts. Is detected, and it is detected that the gas mouth cap 69 is attached. At this time, the connection detection circuit 71
Sends a control signal to the power supply circuit 72 to stop the operation of the video processor 9.

When the gas base cap 69 is removed from the gas base 68, the connection detection terminal 70 is opened without conducting, and in this state, when the connector 8 is connected to the connector receiver 73, the connection base circuit 71 detects the gas base cap 69.
Is detected as not being attached. In this case, the connection detection circuit 71 does not send a control signal to the power supply circuit 72 and activates the video processor 9 so that a normal endoscopy can be performed.

Also, as in the second configuration example shown in FIG.
The connector 8, the gas base 68, and the gas base cap 69 of the endoscope 1, and the connector receiver 73 of the video processor 9
Is set so as to satisfy the relationship of B>C> A, so that the gas base cap 69 is
8, the gas cap 69 hits the video processor 9 and the connector 8 receives the connector 8.
3 may not be connected. Also in this configuration, it is possible to prevent the endoscope inspection when the gas mouth cap 69 is attached, as in the first configuration example of FIG.

Further, as shown in FIG.
The rear end of the connector 8 is stripped of the coating in the connector 8 to expose the signal cable 34. A cable length adjusting circuit 74 is provided in the connector 8, and the signal cable 34 is electrically connected to the cable length adjusting circuit 74. ing. Then, the electrical connection portion 7 which is electrically connected to the cable length adjustment circuit 74 and exposed to the outside is provided.
Numeral 5 is electrically connected to a circuit in the video processor 9 when the connector 8 is connected to the connector receiver 73.

The cable length adjusting circuit 74 is provided with a circuit for changing the electrical characteristics (impedance, etc.) of a not-shown trimmer or the like. When the length of the signal cable 34 is shortened due to repair or the like, the cable length adjusting circuit 74 is adjusted. By using the circuit 74 to add or subtract a circuit corresponding to the changed cable length, it is possible to return to the electrical characteristics before the signal cable 34 is shortened and to match the electrical characteristics. As a result, the structure is such that an optimal electric signal can be always exchanged.

An operating knob may be connected to the cable length adjusting circuit 74, and by operating the operating knob, the value of the cable length to be manually adjusted may be set to adjust the electrical characteristics. Also, the cable length adjustment circuit 7
It is also possible to provide a resistance detecting means at 4 and determine the value of the cable length to be automatically adjusted by measuring the resistance of the signal cable 34 so that the electrical characteristics can be adjusted.

The operation of the above-described embodiment will be described. In the imaging unit 12, since the water-repellent coating 22 is applied to the lens of the imaging optical system, it is difficult for water droplets to adhere. Then, the first lens 1
4 has a structure in which the second lens 15 is fitted, so that even if water vapor enters inside, the boundary between the first lens 14 and the lens frame 23, the boundary between the first lens 14 and the insulating frame 27, the first Since it is necessary to pass through the boundary between the lens 14 and the second lens 15, the invasion path is long, and it is difficult for water vapor to enter. Further, the first lens 14 and the second lens 1
Since the space 21 between 5 is at a high pressure, the penetration of water vapor becomes more difficult.

Since the specific heat of the spacer 20 is lower than that of the first lens 14 and the second lens 15, the first lens 14 and the second lens 15
Before the spacer 20 is cooled, the moisture of the saturated water vapor adheres to the spacer 20 and the first lens 14 and the second lens
It does not adhere to the surface of the lens 15. Therefore, a good image can be always obtained without causing visual field fogging.

When taking out the image pickup unit 12 from the distal end portion 3 of the endoscope 1 for repair, loosen the fixing screw 62, attach a jig having a convex portion to the crimp hole 65 of the removing screw 61, and attach the removing screw 61. Is rotated to move the removal screw 61 to the operation unit 6 side. At this time, the removal screw 61 is attached to the lens frame 2 of the imaging unit 12.
3, the detachable screw 61 pushes the lens frame 23, so that the imaging unit 12 can be easily pushed backward to be taken out.

At this time, the inside diameter of the rear end of the lens frame 23 is smaller than the outside diameter of the step portion of the SID frame 24 facing the projection. Therefore, all the pressing force applied to the lens frame 23 is transmitted straight to the SID frame 24 via the intervening object 28.
Therefore, when removing the imaging unit 12, the lens frame 23
Since no diagonal force is applied between the SID frame 24 and
The lens frame 23 and the SID frame 24 are one rigid body, and the adhesive fixing the two does not peel off, so that the lens frame 23 and the SID frame 24 can be prevented from being separated and broken. Further, since the lens frame 23 and the SID frame 24 are separate bodies, the focus of the imaging optical system can be adjusted.

Also, holes 31 are formed in electric components 32 which generate heat.
Is provided, the contact area between the electric component 32 and the sealing resin 33 is increased. For this reason, heat dissipation is good, and there is an effect of suppressing a rise in temperature of the electric component 32. Furthermore, since the circuit board 30 and the sealing resin 33 are configured to have similar thermal expansion coefficients, the electric component 32 has a structure that is difficult to peel off.

Further, since the cable length adjusting circuit 74 is provided at the end of the signal cable 34 in the connector 8, it is possible to adjust the electric characteristics when the cable length changes. Since the unit 12 can be repaired and the electrical characteristics can be matched, the optimal exchange of electrical signals can always be performed.

As described above, according to the present embodiment, even if the lens frame 23 and the SID frame 24 of the image pickup unit 12 are separately provided so that the focus of the image pickup optical system can be finely adjusted, repair can be performed. Therefore, when the imaging unit 12 is detached, the lens frame 23 and the SID frame 24 can be prevented from being detached and damaged, and a robust imaging unit 12 having sufficient strength can be provided.

FIGS. 8 and 9 relate to a second embodiment of the present invention. FIG. 8 is a cross-sectional view showing the configuration of an image pickup apparatus, and FIG. 9 is a perspective view showing the configuration of a cable clamp.

In the second embodiment, the configuration of the imaging unit of the first embodiment is partially changed. Only parts different from the first embodiment will be described, and similar parts will be denoted by the same reference numerals and description thereof will be omitted.

The imaging unit 12a of the second embodiment is slightly different from the first embodiment in the configuration of the lens frame. A first lens 14a, a second lens 15, a first stop 19, and a spacer 20 are provided in a lens frame 23a. Are fitted to each other, and an SID frame 24 is fitted to the lens frame 23 via an insulating frame 27.

Further, a circuit board 30 and a connection board 80 are connected to the SID lead 29 of the solid-state imaging device 18 of the imaging unit 12a, and a signal cable 34 is soldered to the circuit board 30 and the connection board 80, respectively. It is connected. A cable stopper 81 made of an elastic member such as rubber for fixing the signal cable 34 is adhesively fixed between the circuit board 30 and the connection board 80.

The cable stopper 81 is, as shown in FIG.
It has a concave portion in which the circuit board 30 and the connection substrate 80 are engaged, and a slope portion serving as a guide surface along which the signal cable 34 extends, and has a lateral hole 82 opened on both side surfaces and a rear hole 83 opened on the rear surface. The lateral hole 82 and the rear hole 83 communicate with each other inside.

Also, on the outer peripheral portion of the cable stopper 81,
A soft adhesive 84 such as a silicone adhesive is filled. Further, a bendable blade 85 is covered so as to cover the soft adhesive 84 and the cable stopper 81,
The shield frame 35 is engaged with the inner peripheral portion at the rear end.

The portion corresponding to the curved portion 4 of the cable bundle 36 extending to the rear of the imaging unit 12a is a cable alignment portion 86 in which the signal cable 34 is not twisted, and the cable bundle 36 is flexible. The part corresponding to the tube part 5 is
The signal cable 34 serves as a twisted cable twisted portion 87. The cable arranging section 86 and the cable twisting section 87 are provided with a protective tube 80 made of silicone resin.
a is coated.

In the configuration of the second embodiment, the cable stopper 8
1 is provided with a lateral hole 82 and a rear hole 83 penetrating both sides and a rear surface. Therefore, when the soft adhesive 84 is filled from the lateral hole 82 during assembly, the soft adhesive 84 is ejected from the rear hole 83. The space between the cable stopper 81 and the signal cable 34 is sufficiently filled with the soft adhesive 84. Also,
After the soft adhesive 84 is filled, the protective tube 80a is pushed in and inserted, and the heat-shrinkable tube 38 is contracted, so that the soft adhesive 84 is reliably filled around the signal cable 34 without any gap.

Therefore, the rear end of the imaging unit 12a
It is composed of a cable stopper 81 made of an elastic material, a soft adhesive 84 which is a soft material, a flexible blade 85, and a cable alignment portion 86 where the signal cable 34 is easy to be bent without being twisted. Therefore, the signal cable 34 is easily bent without applying a load, and the signal cable 34 is hardly disconnected.

Thus, according to the second embodiment, similarly to the first embodiment, the lens frame 23a of the image pickup unit and the SID
Even when the frame 24 is formed separately, the lens frame 23a
And the SID frame 24 can be prevented from being detached and damaged, and an imaging unit having a sufficient strength can be provided. In addition, the rear end of the imaging unit can be flexibly configured, and disconnection of the signal cable 34 can be prevented.

FIG. 10 is a sectional view showing the structure of an image pickup apparatus according to the third embodiment of the present invention.

In the third embodiment, the configuration of the image pickup unit of the second embodiment is further partially changed. Only parts different from the first and second embodiments will be described, and similar parts will be denoted by the same reference numerals and description thereof will be omitted.

The image pickup unit 12b according to the third embodiment includes a light transmitting member 88 having a low refractive index made of a fluorine-based liquid or a fluorine resin between the first lens 14a and the second lens 15.
Is enclosed and filled. Thereby, the first lens 1
Water droplets do not adhere to the surfaces of the lens 4a and the second lens 15, and the field of vision is not fogged.

The lead extending from the solid-state imaging device 18 is a bent SID lead 29a, and the SID lead 29a has a circuit board 3 having a bent shape.
0a is connected. By using the circuit board 30a having such a bent shape, the length of the circuit board 30a itself in the longitudinal direction is shortened, and the electric component 32 can be arranged and the signal cable 34 can be connected by effectively utilizing the space. Therefore, the hard length of the imaging unit 12b can be further reduced.

Further, a cable alignment member 89 for rearranging the signal cables 34 in the order in which the signal cables 34 are connected to the circuit board 30a and holding and fixing the connection portions of the signal cables 34 is attached to the end portion of the signal cable 34 where the coating is removed. Have been. The signal cable 34 at the mounting portion of the cable alignment member 89 has a rough surface portion 90 whose surface is rough (indicated by X in the drawing). By providing the cable alignment member 89 in this manner, the distal end portion of the signal cable 34 can be firmly fixed by the cable alignment member 89, and since the signal cable 34 has a reasonable arrangement, a load is applied to the signal cable 34. It has a structure that is hard to be disconnected. Further, since the surface of the signal cable 34 to which the cable alignment member 89 is attached is a rough surface portion 90, the load applied to the cable connection portion can be reduced without slipping between the cables.

The cable bundle 36 of the signal cable 34
Is coated with a protective tube 40b made of a material having a characteristic of being deformed by a gradually applied force and not deformed by a suddenly applied force. Such a protective tube 4
By covering the cable bundle 36 with 0b, the portion that interferes with the built-in object is deformed and dented by the protective tube 40b against the force gradually applied from the built-in object. Since the protection tube 40b repels a suddenly applied force, the structure is such that the cable bundle 36 is hardly damaged and the disconnection can be prevented.

As described above, according to the third embodiment, similarly to the first embodiment, the lens frame 23a of the imaging unit and the SID
Even when the frame 24 is formed separately, the lens frame 23a
And the SID frame 24 can be prevented from being detached and damaged, an imaging unit having sufficient strength can be provided, and a structure in which a load is not easily applied to the signal cable 34 at the rear end of the imaging unit can be provided. Disconnection can be prevented.

[Supplementary Notes] (1) A lens of an objective optical system for forming an image of a subject, a lens frame for holding at least one of the lenses of the objective optical system, and a subject image arranged behind the objective optical system A solid-state image pickup device for imaging the solid-state image pickup device, and an image pickup device frame holding the solid-state image pickup device, wherein the image pickup device frame has a step formed on the outer periphery thereof, and has a first outer portion at a tip end. Having a diameter, and at the rear end side, the first
The lens frame has, at its rear end, an inner diameter larger than a first outer diameter of the image sensor frame, and a second outer diameter of the second frame of the image sensor frame. An imaging device having an outer diameter equal to or smaller than an outer diameter.

(2) The lens frame and the image sensor frame are characterized in that the inner periphery of the rear end of the lens frame and the outer periphery of the front end of the image sensor frame are fitted directly or via an intervening object. 2. The imaging device according to claim 1, wherein

(3) In an image pickup apparatus provided with an objective optical system having two or more lenses, the first lens in the objective optical system has a cylindrical portion into which a member can be fitted. An imaging apparatus, wherein an outer periphery of a second lens is fitted to an inner periphery of a cylindrical portion of the first lens, and the second lens is adhered and fixed.

(4) An endoscope including an endoscope having a curved portion in an insertion portion and an imaging unit disposed in the insertion portion of the endoscope and having a signal cable extending to a rear end side. An endoscope, wherein a protective tube with a slit for covering the signal cable is provided at least at a portion corresponding to the curved portion of the signal cable of the imaging unit.

(5) The endoscope according to appendix 4, wherein a slit is also provided in at least a part corresponding to the bending portion in a jacket of the signal cable.

(6) In an endoscope provided with an image pickup unit disposed inside the distal end portion of the insertion portion and having a signal cable extending to the rear end side, the internal components of the insertion portion have chamfered corners. An endoscope characterized by being made.

(7) The endoscope according to Supplementary Note 6, wherein components in the operating portion and the connector portion connected to the insertion portion are also chamfered at corners.

(8) An image pickup apparatus including an image pickup unit having an objective optical system and an image pickup element, and a front end support frame for engaging at least the front end of the image pickup unit and holding the image pickup unit. In the tip support frame,
The imaging unit is configured to have a threaded portion on the inner surface of the engagement portion, and a cylindrical screwing member that is screwed to the threaded portion is provided, and a step portion is formed on the outer periphery of the distal end portion of the imaging unit. An image pickup device, wherein a front end portion of the imaging unit is fitted to an inner surface of the screw member, and a rear end surface of the screw member and a contact surface of the step portion are in contact with each other. .

(9) An image pickup unit having an image pickup device for picking up a subject image and a signal cable for transmitting an electric signal input / output to / from the image pickup device, and an output signal of the image pickup unit connected to the signal cable of the image pickup unit An image pickup apparatus comprising a video signal processing circuit for processing
In a signal transmission path from the signal cable to the video signal processing circuit, a cable length adjustment circuit capable of adjusting a cable length by changing an electrical characteristic of a circuit corresponding to a length of the signal path is provided. Imaging device.

(10) The cable length adjusting circuit is characterized in that a circuit having an electric characteristic value corresponding to a certain cable length is added or reduced as an electric characteristic of a circuit corresponding to the length of the signal path. 10. The imaging device according to 9.

(11) The image pickup apparatus according to appendix 9, wherein the cable length adjusting circuit has operation means, and changes the value of the cable length to be changed by operating the operation means.

(12) The image pickup apparatus according to appendix 9, wherein the cable length adjusting circuit has resistance detecting means, and measures a resistance of the signal cable to determine a value of a cable length to be adjusted. .

[0070]

As described above, according to the present invention, it is possible to finely adjust the focus of the image pickup optical system and to provide an image pickup apparatus having sufficient strength.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a distal end portion of an insertion section of an endoscope incorporating an imaging device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a dimensional relationship between a lens frame and a CCD frame.

FIG. 3 is an explanatory diagram showing a system configuration of the endoscope apparatus.

FIG. 4 is a sectional view showing a configuration of a signal cable.

FIG. 5 is a block diagram showing a configuration of a disconnection detecting unit.

FIG. 6 is an explanatory diagram showing a first configuration example of a connection portion between a connector of a universal cord and a video processor.

FIG. 7 is an explanatory diagram showing a second configuration example of a connection portion between the connector of the universal cord and the video processor.

FIG. 8 is a cross-sectional view illustrating a configuration of an imaging device according to a second embodiment of the present invention.

FIG. 9 is a perspective view showing a configuration of a cable stopper.

FIG. 10 is a cross-sectional view illustrating a configuration of an imaging device according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope 2 ... Insertion part 3 ... Tip part 12 ... Imaging unit 14 ... 1st lens 15 ... 2nd lens 16 ... 3rd lens 17 ... 4th lens 18 ... Solid-state imaging device (SID) 23 ... Lens frame 24 ... SID frame 27 ... Insulation frame 28 ... Inclusion

Claims (1)

[Claims] 1. A lens of an objective optical system that forms an image of a subject, a lens frame that holds at least one of the lenses of the objective optical system, and a solid object that is arranged behind the objective optical system and captures an image of the subject. An imaging device comprising: an imaging element; and an imaging element frame that holds the solid-state imaging element, wherein the imaging element frame has a step formed on an outer periphery thereof, and has a first outer diameter at a tip end. A second outer diameter larger than the first outer diameter on the rear end side, and the lens frame has an inner diameter larger than a first outer diameter of the imaging element frame at a rear end portion thereof. And the second of the image sensor frame
An imaging device characterized by having an outer diameter equal to or smaller than the outer diameter of the imaging device.