JPH06315282A - Actuator - Google Patents

Abstract

PURPOSE:To reduce the number of components and the cost of machining and assembly, miniaturize the actuator body as a while, and avoid the breakage of the impact force generating section when mechanical impact is externally applied. CONSTITUTION:The body of this actuator consists only of a mobile body 16 fitted in a stationary section 3a and 7 such that it can be slide; and a piezoelectric element 17, secured on the mobile body 16, that is expanded/contracted by the application of voltage and exerts impact force on the mobile body 16 through the expanding/contracting motion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for driving a driven portion by utilizing the expansion / contraction operation of a piezoelectric / electrostrictive element.

[0002]

2. Description of the Related Art Conventionally, as a piezoelectric actuator, for example, as shown in Japanese Patent Publication No. 4-52070, one end of a piezoelectric element is fixed to a moving body slidably frictionally engaged with a fixed portion. It is known that the inertial body is fixed to the other end of the element. During operation of this piezoelectric actuator, the piezoelectric element is rapidly expanded and contracted to apply acceleration to the inertial body, and the resulting inertial force is applied to the movable body, causing the movable body to slide with respect to the fixed portion and the piezoelectric actuator to move. It is designed to run.

Further, for example, as shown in JP-A-4-63309 and JP-A-4-69071, a structure in which a lens of a camera is driven by using the above actuator, or, for example, JP-A-4-177214. As disclosed in Japanese Patent Laid-Open Publication No. 2004-163, there is disclosed a device which uses the actuator to drive an optical system of an endoscope, bend a treatment tool to be inserted into a body cavity, open and close forceps, and the like.

[0004]

However, in the above-described conventional structure, the movable body is fixed to one end of the piezoelectric element of the piezoelectric actuator, and the inertial body is fixed to the other end of the piezoelectric element. The number of components increases,
There is a problem that processing and assembling costs increase.

Further, there is a problem that the entire size of the piezoelectric actuator becomes large, and when the piezoelectric actuator receives a mechanical shock from the outside, the inertial force generated in the inertial body is applied to the piezoelectric element, which may damage the piezoelectric element. There is.

The present invention has been made in view of the above circumstances, and its purpose is to reduce the number of constituent parts, to reduce the cost of processing and assembling, and to make the whole compact and to mechanically work from the outside. An object of the present invention is to provide an actuator in which a piezoelectric element is less likely to be damaged when it receives an impact.

[0007]

SUMMARY OF THE INVENTION According to the present invention, an actuator is formed only from a base, a moving body slidably frictionally engaged with the base, and an impact force generating portion coupled to the moving body. Is.

[0008]

[Operation] An impact force is applied to the moving body by the impact force generation unit,
This moving body is made to slide with respect to the base.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to (B). In this embodiment, the main body 3a of the tip forming portion 3 in the insertion portion 2 of the endoscope 1 shown in FIG.
A piezoelectric actuator is applied as a driving means of the focus adjusting mechanism 4 of the observation optical system incorporated therein.

In this case, the observation optical system of the endoscope 1 is provided with an observation window portion 5 on the tip surface of the tip forming portion 3. Further, an observation optical system mounting hole is formed inside the distal end configuration body 3a, and an actuator mounting hole 3b of the focus adjusting mechanism 4 is formed adjacent to the mounting hole around the mounting hole.

Further, in the observation optical system, a front side fixed lens 6 arranged to face the observation window portion 5 and a rear side fixed lens 8 arranged to face the front side fixed lens 6 at a distance from each other,
A focus adjusting lens 9 which is arranged between the fixed lenses 6 and 8 and is movable along the optical axis direction of the observation optical system is provided. The respective lenses 6, 8 and 9 form an objective lens group of the observation optical system.

A lens frame 10 of a focus adjusting lens 9 is supported by a lens barrel 7 holding front and rear fixed lenses 6 and 8 so as to be movable along the optical axis of the observation optical system. A connecting arm 11 is provided on the lens frame 10 so as to project toward the actuator mounting hole 3b. In this case, the lens barrel 7 is formed with a guide hole 12 through which the connecting arm 11 is inserted.

Further, an actuator unit 13 of a piezoelectric actuator is mounted in the actuator mounting hole 3b. Then, the lens frame 10 of the focus adjustment lens 9
The actuator unit 13 is moved and operated along the optical axis direction of the observation optical system.
Further, behind the fixed lens 8 on the rear side, a solid-state image sensor 14 such as a CCD for converting an observation image formed by the objective lens group of the observation optical system into an electric signal is arranged.

As shown in FIG. 1, the actuator unit 13 has a moving body 16 connected to the connecting arm 11 of the lens frame 10 via a connecting member 15, and the moving body 1.
6, a piezoelectric element (or an electrostrictive element) 17 is provided as an impact force generation unit that performs an expansion / contraction operation by applying a voltage and applies an impact force to the moving body 16 by the expansion / contraction operation. Here, the piezoelectric element and the electrostrictive element are, for example, barium titanate, lead zirconate titanate, electrodes are formed on ceramics such as porcelain, and mechanical elongation deformation is caused by applying a direct current to the electrodes. is there. The piezoelectric element is an element in which a distortion proportional to the electric field strength is generated by the reverse voltage effect. Further, the electrostrictive element is an element in which distortion proportional to the square of the electric field strength occurs when a drive voltage is applied.

A concave portion is formed on each of the front and rear end surfaces of the moving body 16. The rear end portion of the connecting member 15 is fitted and adhered to the concave portion of the front end surface of the moving body 16, and the front end portion of the piezoelectric element 17 is fitted and adhered to the concave portion of the rear end surface of the moving body 16. When the weight of the lens frame 10 is significantly larger than that of the actuator unit 13, the connecting member 15 is made of an elastic material such as rubber.

Further, beam portions 16a, 16b extending rearward are provided on the outer peripheral portion of the moving body 16 so as to project therefrom. The extended end portions of the beam portions 16a and 16b are in pressure contact with the base including the lens barrel 7 and the tip component body 3a,
It is frictionally engaged with an appropriate friction force. The beam portion 16
Each of a and 16b may be a plurality of extending portions projecting on the outer peripheral portion of the moving body 16, or may be circular pipe-shaped portions projecting on the outer circumferential portion of the moving body 16.

Further, the lens barrel 7 is formed with a holding hole 7a for holding the other end of the piezoelectric element 17 in an inserted state. The other end of the piezoelectric element 17 is held in the holding hole 7a of the lens barrel 7 in a state of being fitted by loose fitting.

Further, the piezoelectric element 17 is the insertion portion 2 of the endoscope 1.
Also, it is connected to an external control section 21 via the operation section 19 and the lead wire 18 arranged in the universal cord 20 shown in FIG. Here, the lead wire 18 attached to the piezoelectric element 17 is fixed to the piezoelectric element 17 at the following two points as shown in FIG. That is, one of the points is soldered to the electrode portion 17a of the piezoelectric element 17, and the other point is fixed to the dummy portion 17b of the piezoelectric element 17 with an adhesive. The piezoelectric element 17 may be vertically stacked, horizontally stacked, or single-layered.

The surface of the lens barrel 7 and the surface of the movable body 16 are subjected to a surface treatment for improving wear resistance, for example, alumite oxalate and titanium coat. further,
The surface of the piezoelectric element 17 is provided with a parylene coat for improving temperature and humidity resistance and chemical resistance.

Further, the control section 21 has, for example, each drive waveform of the first drive waveform of the piezoelectric element 17 shown in FIG. 4 (A) and the second drive waveform of the piezoelectric element 17 shown in FIG. 4 (B). A voltage applying means for applying a voltage to the piezoelectric element 17 is provided. Here, in the first drive waveform, within a predetermined set time T of 1 pulse, an a region where the applied voltage is gradually decreased from the set voltage to the 0 potential and a region where the applied voltage is rapidly increased from the 0 potential to the predetermined set voltage. area b. Further, in the second drive waveform, within a predetermined set time T of one pulse, a region c in which the applied voltage is gradually increased from the 0 potential to the predetermined set voltage, and d is rapidly decreased from the set voltage to the 0 potential. And a region are provided.

Next, the operation of the above configuration will be described.
First, the operation of the actuator unit 13 driven by the first drive waveform of FIG. 4A will be described with reference to FIG. When the actuator unit 13 is stopped, the moving body 16 moves the lens barrel 7 and the tip forming portion main body 3a.
And is held in a frictionally engaged state with an appropriate frictional force.

When a voltage having the first driving waveform is applied to the piezoelectric element 17 of the actuator unit 13, the piezoelectric element 17 contracts slowly in the area a of the first driving waveform and expands rapidly in the area b. Repeat the cycle.

That is, when the piezoelectric element 17 contracts slowly in the area "a" of the first drive waveform, the moving body 16 is moved as shown in FIG.
As shown in a of (A), the lens barrel 7 and the tip component body 3
It is held still by the frictional force of the contact surface with a.

Further, when the piezoelectric element 17 expands rapidly in the region b of the first drive waveform, the moving body 16 is pressed to the left in FIG. 5A by the abrupt expansion operation of the piezoelectric element 17. Impact force is generated. Therefore, the moving body 16 has a center of gravity determined by the weight of the piezoelectric element 17 and the mass of the moving body 16 by the impact force from the piezoelectric element 17 as a fixed point in the left direction in the figure as shown in b of FIG. 5 (A). Moving.

When the actuator unit 13 is driven by the second drive waveform shown in FIG. 4B, the actuator unit 13 operates as shown in FIG. 5B.

When a voltage having the second drive waveform is applied to the piezoelectric element 17 of the actuator unit 13, the piezoelectric element 17 slowly expands in the region c of the second drive waveform and abruptly in the region d. Repeat the shrinking cycle.

That is, when the piezoelectric element 17 slowly extends in the c region of the second drive waveform, the moving body 16 is moved to the position shown in FIG.
As shown in c of (B), the lens barrel 7 and the tip component body 3
It is held still by the frictional force of the contact surface with a.

Furthermore, when the piezoelectric element 17 contracts abruptly in the d region of the second drive waveform, the abrupt contraction of the piezoelectric element 17 causes the moving body 16 to be pulled to the right in FIG. 5B. Power is generated. Therefore, the moving body 16 moves to the right in the figure as a fixed point with the center of gravity determined by the weight of the piezoelectric element 17 and the mass of the moving body 16 by the impact force from the piezoelectric element 17 as a fixed point. Moving.

Therefore, the actuator unit 13
When the first drive waveform is applied to the piezoelectric element 17 during the operation of, the moving body 16 moves leftward in FIG. 1 and moves when the second drive waveform is applied to the piezoelectric element 17. The body 16 retreats to the left in the figure. As a result, the lens frame 1 of the focus adjustment lens 9 is linked to the operation of the moving body 16.
Since 0 also moves back and forth in the same direction, the position of the focus adjustment lens 9 can be moved in the front and back direction to adjust the focus position of the objective lens group of the observation optical system. The operation of the actuator unit 13 has been confirmed by an experiment described later by the inventors.

Therefore, in the above-mentioned structure, the moving body 16 connected to the connecting arm 11 of the lens frame 10 via the connecting member 15 and the moving body 16 fixed to the moving body 16 and expanding and contracting by applying a voltage thereto. However, since the actuator unit 13 is configured only by the piezoelectric element 17 that applies an impact force to the moving body 16 by this expansion and contraction operation, the inertial body used in the conventional piezoelectric actuator can be omitted. Therefore, the number of constituent parts can be reduced as compared with the conventional piezoelectric actuator, the processing and assembling costs can be reduced, and the actuator unit 1
The whole 3 can be miniaturized.

Further, the focus adjusting mechanism 4 of the observation optical system of the endoscope 1 is particularly applicable to the actuator unit 13 having the above-mentioned configuration.
Since it is used as an actuator of the endoscope 1, the length of the rigid portion formed by the distal end forming portion 3 of the insertion portion 2 of the endoscope 1 can be suppressed, and the patient at the time of inserting the insertion portion 2 of the endoscope 1 can be suppressed. The burden can be reduced.

In addition, the front end of the piezoelectric element 17 is fitted into the concave portion of the rear end surface of the moving body 16 to be bonded, and the lens barrel 7 is attached.
Since the other end of the piezoelectric element 17 is held in the holding hole 7a by being loosely fitted, the piezoelectric element 17 can be restrained from deforming in the direction perpendicular to the expansion and contraction direction. Therefore, it is possible to prevent the piezoelectric element 17 from being deformed in the direction perpendicular to the expansion / contraction direction and cracked by a mechanical shock from the outside, and the piezoelectric element 17 is damaged when the mechanical shock is applied from the outside. It can be made into a difficult structure.

When the weight of the lens frame 10 is significantly larger than that of the actuator unit 13, the connecting member 15 is made of an elastic material such as rubber, so that the moving body 16 of the actuator unit 13 is prevented from moving rapidly. On the other hand, it is possible to prevent the lens frame 10 from following.
Therefore, when the weight of the lens frame 10 is significantly larger than that of the actuator unit 13, the fixed point approaches the moving body 16 as in the case where the connecting member 15 is made of a hard material, and one cycle of the drive waveform is generated. Thus, it is possible to prevent the moving amount of the moving body 16 from decreasing, and it is possible to prevent the movement of the actuator unit 13 from being hindered.

FIG. 6A shows an experimental model relating to the output characteristics of the actuator unit 13 during operation. In FIG. 6A, P is the load of the actuator unit 13 and Q is the base. In addition, M shows the mass body of the conventional actuator. further,
FIG. 6B shows a first drive waveform when the actuator unit 13 of the experimental model is moved forward, and FIG. 6C shows a second drive waveform when the actuator unit 13 is moved backward.

Here, in the first drive waveform, within a predetermined set time T of 1 pulse, from 0 potential to a predetermined set voltage (74
a first region in which the applied voltage rises rapidly up to v), and a second region in which the applied voltage is held constant at a set voltage for a predetermined time,
And a third region for gradually reducing the applied voltage from the set voltage to the 0 potential, the first region: the second region: the third region.
The area ratio is set to 4:13:79. Further, in the second drive waveform, the fourth region in which the applied voltage is gradually increased from the 0 potential to the predetermined set voltage (74v) within the predetermined set time T of 1 pulse, and the abruptly changed from the set voltage to the 0 potential. And a sixth region for keeping the applied voltage at 0 potential for a predetermined time, and the ratio of the fourth region: the fifth region: the sixth region is set to 79: 4: 13. ing. The piezoelectric element 17 of the actuator unit 13 has a size of 1.6 × 0.8 × 9 and a displacement amount of 7 μm.
m / 100 vDC and weight: 0.1 g, respectively. Further, the moving body 16 is set to have a weight of 30 mg.

The experimental results of the actuator unit 13 of the above experimental model are shown in Table 1 below. Here, the actuator mass means the moving body 16 + the piezoelectric element 1
7 + indicates the total weight of the mass body M, and * indicates that the mass of the mass body M is set to 0.0 g.

[0037]

[Table 1]

That is, as is clear from Table 1 above, the actuator unit 13 without the mass body M outputs /
Good weight characteristics. This is because, in the actuator unit 13 without the mass body M, the portion corresponding to the mass body M is also the piezoelectric element 17, and expands and contracts when a voltage is applied to the moving body 16.
It is considered that this is to increase the displacement amount of.

Further, FIG. 7A shows a second embodiment of the present invention. This is because the rear end portion of the piezoelectric element 17 is adhered to the leaf spring 31 and the leaf spring 31 is supported while being pressed between the beam portions 16a and 16b of the moving body 16 so that the piezoelectric element 17 extends and contracts. And is configured to regulate the deformation in the vertical direction. In this case, since it is not necessary to form the holding hole 7a in the lens barrel 7, the structure of the lens barrel 7 can be simplified.

Further, as in the modification shown in FIG. 7B, a regulating member 32 is attached to the back of the beam portions 16a and 16b of the moving body 16, and the rear end portion of the piezoelectric element 17 is fixed by the regulating member 32. The piezoelectric element 17 may be supported in a sandwiched state to restrict the deformation of the piezoelectric element 17 in the direction perpendicular to the expansion / contraction direction.

Further, as in the third embodiment of the present invention shown in FIG. 8, a circular pipe 33 is arranged in the actuator mounting hole 3b, and the movable body 16 of the actuator unit 13 is inserted in the circular pipe 33. The lever tube 33 may be incorporated into the lens barrel 7 together.

In the above embodiment, the actuator unit 13 is used as the actuator of the focus adjusting mechanism 4 of the observation optical system of the endoscope 1, but the endoscope 1
It can also be used as a drive unit for the zoom mechanism of the observation optical system or the aperture adjustment mechanism.

FIG. 9 shows a fourth embodiment of the present invention. This is the lens frame 10 of the focus adjustment lens 9.
Is used as a part of the actuator unit 13 of the focus adjustment mechanism 4 for performing focus adjustment.

That is, in this embodiment, the tip of the cylindrical piezoelectric element 41 is attached to the lens frame 10 so that the lens frame 10 functions as a moving body of the actuator unit 13. In this case, in order to prevent diffused reflection on the surface of the cylindrical piezoelectric element 41, for example, BC
Black processing such as r processing is applied.

Further, FIG. 10A shows the lens barrel 7 and the lens frame 1.
It shows a frictional engagement portion that applies a static frictional force between 0 and 0. In this case, on the outer peripheral portion of the lens frame 10, a beam portion 42 extending toward the rear side is provided so as to project. The extended end portion of the beam portion 42 is pressed against the lens barrel 7 and frictionally engaged with it with an appropriate frictional force.

The cylindrical piezoelectric element 41 shown in FIG.
When the voltage of each drive waveform shown in (A) and (B) is applied,
The piezoelectric element 41 expands and contracts in the optical axis direction of the focus adjustment lens 9 of the endoscope 1, and as a result, the lens frame 10, which is a moving body, moves forward or backward according to the drive waveform. This allows
By moving the position of the focus adjustment lens 9 in the front-back direction, the focus position of the objective lens group of the observation optical system can be adjusted.

Therefore, even with the above-described structure, the same effect as that of the first embodiment can be obtained, and in this embodiment, in particular, the focus adjustment of the lens frame 10 of the focus adjusting lens 9 is performed. Since it is used as a part of the actuator unit 13 of the mechanism 4, it is possible to reduce the outer diameter dimension of the distal end forming portion 3 of the endoscope 1, and the burden on the patient when inserting the insertion portion 2 of the endoscope 1. Can be further reduced.

FIG. 10B shows the lens barrel 7 and the lens frame 1.
It shows the 1st modification of the friction engagement part which gives static frictional force between 0 and 0. In this case, an electromagnet 43 is attached to the lens barrel 7. In this case, the lens frame 10 is made of, for example, iron or another material having a high magnetic permeability, and is attracted by the magnetic force of the electromagnet 43 of the lens barrel 7 to give a static frictional force between the lens barrel 7 and the lens frame 10. It is configured.

FIG. 10C shows a second modification of the friction engagement portion. This is the lens barrel 7 and the lens frame 1.
A second piezoelectric element 44 that can be expanded and contracted in the radial direction of the endoscope 1 is provided between the piezoelectric element 44 and 0, and the piezoelectric element 44 is extended to apply a static frictional force between the lens barrel 7 and the lens frame 10. It is the one.

FIG. 10D shows a third modification of the friction engagement portion. This is because the first electrode 45 is attached to the lens barrel 7, the second electrode 46 is attached to the joint surface of the lens frame 10 with the lens barrel 7, and the lead wires 47 and 48 are attached to the respective electrodes. By applying voltages of opposite polarities to the electrodes 45 and 46, the electrodes 45 and 46 are attracted to each other, and as a result, a static friction force is applied between the lens barrel 7 and the lens frame 10.

FIG. 11 shows a fifth embodiment of the present invention. This applies the actuator of the present invention as a drive means of a bending mechanism for bending the tip of a treatment tool (forceps) 51.

In this treatment tool 51, a forceps main body 53 is attached to the tip of an insertion member 52 formed of, for example, a flexible thin tube.
Is provided. Further, a flexible tube 54 is arranged outside the insertion member 52. This flexible tube 5
An actuator unit 55, which is a piezoelectric actuator, is attached to the tip portion of 4.

The actuator unit 55 is provided with a unit case 56 in which one end of a double circular pipe consisting of an inner pipe and an outer pipe is connected in a closed state. An opening surface 56a is formed at the tip of the unit case 56. The tip of the flexible tube 54 is fixed to the outer peripheral surface of the outer tube of the unit case 56.

The tip of the insertion member 52 of the treatment instrument 51 extends to the outside of the unit case 56, and in this state, the insertion member 52 is attached to the inner peripheral surface of the inner tube of the unit case 56.
The outer peripheral surface of is fixed.

Further, inside the unit case 56, there are provided a cylindrical moving body 57 and a piezoelectric element 58 which constitute a piezoelectric actuator. in this case,
The moving body 57 is slidably frictionally engaged with the inner pipe and the outer pipe of the unit case 56.

Further, the tip of the lead wire 59 is connected to the piezoelectric element 58. The lead wire 59 is fixed at the connecting end portion between the inner pipe and the outer pipe of the unit case 56, and even if the moving body 57 moves, the lead wire 59 on the hand side is fixed.
Is not pulled. Further, the movable body 57 and the distal end portion of the insertion member 52 of the treatment instrument 51 are connected by an operation wire 60.

Then, when the voltage of each drive waveform shown in FIGS. 4A and 4B is applied to the piezoelectric element 58 in the unit case 56, the piezoelectric element 58 is inserted into the insertion member 5 of the treatment instrument 51.
2 expands and contracts in the axial direction, and as a result, the moving body 57 moves forward or backward according to the drive waveform. Since the operation wire 60 can be pushed and pulled in accordance with the movement of the moving body 57, the distal end portion of the insertion member 52 can be curved or returned.

Therefore, also in this case, as in the first embodiment, the inertial body used in the conventional piezoelectric actuator can be omitted, so that the number of constituent parts can be reduced as compared with the conventional piezoelectric actuator, and processing, The cost of assembly can be reduced, and the size of the entire actuator unit 55 can be reduced.

FIG. 12 shows a sixth embodiment of the present invention. This applies the actuator of the present invention as a driving means of an opening / closing mechanism for opening and closing the forceps main body 64 arranged at the tip of the insertion member 62 of the treatment tool 61.

In this case, a tubular tip rigid portion 63 which constitutes a unit case of the actuator unit 66 is fixed to the tip of the insertion member 62. This tip hard part 6
A movable body 67 of the actuator is provided in
Is slidably frictionally engaged with the wall surface of the inner peripheral surface of the.

An opening / closing portion 65 which is a pantograph mechanism of the forceps body 64 is attached to the moving body 67.
Then, the moving body 67 of the actuator is moved to
By opening and closing the inside, the opening / closing part 65 is opened and closed.

A lead wire is connected to the piezoelectric element 68 of the actuator unit 66. This lead wire is fixed to a stopper 69 in the hard tip portion 63 so that the lead wire on the proximal side cannot be pulled even if the moving body 67 of the actuator unit 66 moves.

Therefore, also in this case, as in the first embodiment, the inertial body used in the conventional piezoelectric actuator can be omitted, so that the number of constituent parts can be reduced as compared with the conventional piezoelectric actuator, and machining, The cost of assembly can be reduced, and the entire actuator unit 66 can be downsized.

Further, FIG. 13 shows the focus adjusting mechanism 4 of the endoscope 1.
5 shows a first modified example in which a piezoelectric actuator is used as a drive unit for performing focus adjustment by moving the focus adjustment lens 9 for focus in the optical axis direction back and forth.

That is, in this modification, the focus adjustment lens 9
A connecting arm 71 is provided so as to project from the outer peripheral portion of the lens frame 10. A tube 72 is provided on the connecting arm 71 so as to project rearward.

A fixed tube 73 is fixed to a fixed portion such as the lens barrel 7 in the tip forming portion 3. An actuator unit 74 of a piezoelectric actuator is attached to the fixed tube 73. In this case, the actuator unit 74
Is set to a size (for example, φ4 × 20 or less) that can be incorporated into the distal end portion of the endoscope 1.

Further, the actuator unit 74 is provided with a laminated piezoelectric element 76, a driving body 77 having a rectangular cross section perpendicular to the expansion / contraction direction, and a fixing member 75 for fixing one end of the piezoelectric element 76. Has been. Here, the fixing member 75 is fixed to the rear end of the fixed tube 73.

The driving body 77 is fixed to the other end of the piezoelectric element 76. The drive member 77 is provided with a beam portion 78 that extends toward the front side. The extended end portion of the beam portion 78 is press-fitted into the tube body 72 of the connecting arm 71, and is frictionally engaged with an appropriate frictional force.

Further, one end of a lead wire 79 is connected to the piezoelectric element 76. The other end of the lead wire 79 is connected to the actuator drive circuit 80. This actuator drive circuit 80 has the circuit configuration shown in FIG. That is, the actuator drive circuit 80 is provided with a control unit 81, and the control unit 81 includes a defocus signal output unit 82, a first analog switch 83,
The second analog switches 84 are respectively connected.

A first sin wave oscillating unit 85 is connected to one switching terminal of the first analog switch 83 through a full wave rectifying unit 86, an inverting unit 87 and an adding unit 88 in this order. Here, a bias voltage circuit 89 is connected to the input side of the adder 88. Further, the connection portion of the full-wave rectifying unit 86 and the inverting unit 87 is connected to the other switching terminal of the first analog switch 83.

Further, one switching terminal of the second analog switch 84 is connected to the common terminal of the first analog switch 83. This second analog switch 84
A second sin wave oscillating unit 90 is connected to the other switching terminal of the. Further, the piezoelectric element 76 of the actuator unit 74 is connected to the common terminal of the second analog switch 84 via the amplifier 91.

Next, the operation of the actuator drive circuit 80 having the above structure will be described. First, the control unit 81 recognizes the defocus amount based on the signal from the defocus signal output unit 82, and switches the first analog switch 83 and the second analog switch 84 to determine the drive waveform for energizing the piezoelectric element 76. Change.

Here, when the focus adjustment lens 9 is moved to the left in FIG. 13 for focus adjustment, the voltage having the drive waveform shown in FIG. 15A is applied to the piezoelectric element 76. Further, when the focus adjustment lens 9 is moved to the right in FIG. 13, the voltage having the drive waveform shown in FIG. 15B is applied to the piezoelectric element 76. The peak voltage of the voltage waveform applied to the piezoelectric element 76 is set to 300 V or less due to the withstand voltage of the piezoelectric element 76, and the frequency is set to about several tens kHz or less so as not to excessively heat the element.

Further, when the defocus amount is measured without moving the actuator unit 74, FIG.
The defocus amount is obtained by applying the voltage of the drive waveform of (C) to the piezoelectric element 76 and subjecting the lens frame 10 to simple vibration to modulate the contrast component of the video signal. In addition,
This method is generally called a modulation contrast method, and a detailed description is omitted here.

When the voltage having the drive waveform shown in FIG. 15A is applied to the piezoelectric element 76, the time differential value of the voltage is discontinuously inverted (the movement direction of the piezoelectric element 76 suddenly contracts from the extending direction). The lens frame 10 is driven by the driver 77.
On the other hand, in FIG. 13, slide to the left. At this time, the step movement amount is about several μm or less. It should be noted that, at other points of the drive waveform of FIG. 15A, the lens frame 10 moves together with the driving body 77 and does not slip.

Therefore, when the voltage having the drive waveform shown in FIG. 15A is continuously applied to the piezoelectric element 76, the lens frame 10 as a whole moves to the left in FIG. The amount of movement at this time is about a dozen mm / s or less.

Further, when the voltage having the drive waveform of FIG. 15B is applied to the piezoelectric element 76, the lens frame 10 moves to the right in FIG. 13 due to the opposite phenomenon. In addition, FIG.
When the voltage of the drive waveform of (C) is applied to the piezoelectric element 76, the lens frame 10 moves together with the driving body 77, so that the lens frame 10 vibrates monotonously on the optical axis.

Therefore, in the above-mentioned structure, since the lens frame 10 can be linearly driven in the forward and reverse directions by one actuator unit 74, the endoscope 1 can be downsized, and the endoscope 1 for the patient can be reduced. The burden is reduced and the cost is reduced.

FIG. 16 shows a modification of the drive circuit for the actuator shown in FIG. The actuator drive circuit includes a manual switch 101, an analog switch 102 operated by the manual switch 101, an amplifier 103, a trapezoidal wave oscillator 104,
A triangular wave oscillating unit 105 and a multiple resistor 106 are provided respectively.

In this case, the trapezoidal wave oscillator 104 is connected to one switching terminal of the analog switch 102, and the triangular wave oscillator 105 is connected to the other switching terminal.
Further, the piezoelectric element 76 of the actuator unit 74 is connected to the common terminal of the analog switch 102 via the amplifier 103. In addition, the trapezoidal wave oscillator 104
The triangular wave oscillating unit 105 is connected to the oscillation frequency adjusting volumes 106a and 106b of the multiple resistor 106, and the amplifier 103 is connected to the gain adjusting volume 106c of the multiple resistor 106.

Next, the operation of the actuator drive circuit having the above structure will be described. First, the manual switch 1
01 switches the analog switch 102. Then, along with the switching operation of the analog switch 102, the triangular wave oscillating unit 105 or the trapezoidal wave oscillating unit 104.
One of the outputs is applied to the piezoelectric element 76 of the actuator unit 74 via the amplifier 103.

Here, when the output of the triangular wave oscillating unit 105 is applied to the piezoelectric element 76, the lens frame 10 is moved relative to the driving body 77 when the applied voltage value reaches the upper limit.
Glide in the left direction. At other times than that time, the lens frame 10 moves together with the driving body 77, so that the lens frame 10 moves leftward in FIG. 13 in total.

When the output of the trapezoidal wave oscillator 104 is applied to the piezoelectric element 76, the lens frame 10 is moved relative to the driver 77 in FIG.
Move to the right.

Further, the multiple resistor 106 is configured to linearly change the oscillation frequency of the triangular wave oscillating unit 105 or the trapezoidal wave oscillating unit 104, and also to linearly change the gain of the amplifier 103. However, the oscillation frequency of the triangular wave oscillator 105 or the trapezoidal wave oscillator 104 is inversely proportional to the gain of the amplifier 103. In this case, since the motion velocity and acceleration of the driving body 77 do not change even if the resistance value of the multiple resistor 106 is changed, the lens frame 10 is moved relative to the driving body 77 at a point other than the upper limit point of the triangular wave and the lower limit point of the trapezoidal wave. It does not slip.

Since the speed of motion of the drive body 77 is the same before and after the point where the speed of motion of the drive body 77 is discontinuously inverted,
The acceleration α generated at that time is also the same. Here, the acceleration α is as follows.

Α = speed before inversion−speed after inversion / Δt Note that Δt is determined by the time resolution of the amplifier 103 and the oscillating units 104 and 105, and hardly depends on the oscillation frequency. Therefore, at this point, the lens frame 10 can slide with respect to the driving body 77. At this time, since the lens frame 10 and other conditions such as the mass of the driving body 77 do not change, the lens frame 10 slides by the same amount per pulse even if the oscillation frequency is changed. However, since the oscillation frequency has changed, the total movement amount of the lens frame 10 per unit time changes.

Therefore, in the actuator drive circuit having the above structure, the speed of the focus adjustment operation of the focus adjustment lens 9 can be controlled without affecting the operation of the actuator unit 74.

FIG. 17 shows a second modification of the actuator. This is provided with the second piezoelectric element 111 sandwiched on the base end side of the extending portion 78 of the driving body 77 in the actuator unit 74 of FIG. The lead wire 11 is connected to the second piezoelectric element 111.
One end of 2 is connected. The other end of the lead wire 112 is connected to the actuator drive circuit shown in FIG.

The actuator drive circuit shown in FIG. 18 has the same structure as the actuator drive circuit shown in FIG.
The control mechanism of No. 1 is added. That is, this FIG.
In the actuator drive circuit of No. 8, the first comparator 113,
Second comparator 114, OR circuit 115, AND circuit 11
6, a third analog switch 117 and an amplifier 118 are added respectively.

Next, the operation of the actuator drive circuit having the above configuration will be described. First, the first comparator 113 outputs an output when the voltage becomes lower than a certain set voltage. Furthermore, the second
The comparator 114 outputs an output when the voltage exceeds a certain set voltage.

Therefore, during the time when the piezoelectric element 76 is energized with a signal other than the point where the time differential value of the voltage shows discontinuity on the inverted signal and the non-inverted full-wave rectified signal, the second piezoelectric The power supply to the element 111 is stopped. At this time, the second piezoelectric element 111 contracts in the direction perpendicular to the optical axis.
As a result, the extension portion 78 of the piezoelectric element 76 and the connecting arm 71 are
The contact between the tube body 72 and the
Does not follow the movement of the driving body 77.

Therefore, in the above-mentioned structure, the lens frame 10 does not unnecessarily slide on the lens barrel 7, so that dust is prevented from coming out from the sliding contact portion between the lens frame 10 and the lens barrel 7. Therefore, it is possible to prevent dust that has come out of the sliding contact portion between the lens frame 10 and the lens barrel 7 from appearing as a stain on the image.

FIG. 19 shows a third modification of the actuator. This uses an actuator having a structure different from that of the sixth embodiment shown in FIG. 12 as a driving means of an opening / closing mechanism for opening and closing the forceps main body 124 arranged at the tip of the insertion member 122 of the treatment instrument 121.

That is, as shown in FIG.
The fixed tube 123 that accommodates the actuator unit 126 having substantially the same configuration as the actuator unit 74 of No. 3 is fixed. In the fixed tube 123, the laminated piezoelectric element 127 of the actuator unit 126, and the driving body 128 having a rectangular cross section perpendicular to the expansion / contraction direction,
A fixing member 123a that fixes one end of the piezoelectric element 127 is provided. Here, the fixing member 123a is the fixed tube 1.
It is fixed to the rear end of 23.

The driving body 128 is fixed to the other end of the piezoelectric element 127. The drive body 128 is provided with a beam portion 128a extending toward the front side. The extended end portion of the beam portion 128a is press-fitted into the cylinder of a bottomed cylindrical slider 129 slidably mounted in the fixed tube 123, and is frictionally engaged by an appropriate friction force.

Further, the slider 129 has an opening / closing portion 125, which is a pantograph mechanism of the forceps body 124, attached to the tip portion thereof. The slider 129 is moved back and forth in the fixed tube 123, so that the opening / closing portion 125 is opened / closed.

The piezoelectric element 127 has a lead wire 131.
One end of is connected. The other end of the lead wire 131 is connected to the actuator drive circuit 80 incorporated in the actuator drive device 130.

FIG. 20 shows a fourth modification of the actuator. This uses an actuator unit 143 having substantially the same configuration as the actuator unit 74 of FIG. 13 as a drive means of the forceps raising base 142 of the side-view endoscope 141.

The actuator unit 143 is provided with a laminated piezoelectric element 144 and a driving body 146 connected to the piezoelectric element 144 via a connecting rod 145. Here, one end of the piezoelectric element 144 is connected to the endoscope 141.
It is fixed to the body of the tip component.

Further, a cylindrical slider 14 having a bottom for pressing the forceps raising base 142 is provided on the inner wall surface of the body of the tip forming section.
7 is slidably mounted. A beam portion at the tip of the driving body 146 is press-fitted into the cylinder of the slider 147,
It is frictionally engaged with an appropriate friction force.

Therefore, in this case, the slider 147 is slid by the actuator unit 143, and the forceps raising base 142 is erected with the sliding operation of the slider 147.

FIG. 21 shows a fifth modification of the actuator. This uses an actuator unit 156 having substantially the same configuration as the actuator unit 74 of FIG. 13 as a driving unit of a bending mechanism that bends the distal end of the treatment instrument 151.

The treatment instrument 151 is provided with a guide tube 154 such as a multi-lumen tube. The insertion member 152 of the treatment instrument 151 is inserted into one lumen of the guide tube 154, and the forceps main body 153 is arranged at the tip of the insertion member 152.

Furthermore, the other lumen 1 of the guide tube 154.
An actuator unit 156 is mounted inside 55. The actuator unit 156 is provided with a laminated piezoelectric element 157 and a driving body 158. The beam portion of the driving body 128 is press-fitted into a cylinder of a bottomed cylindrical slider 159 slidably mounted in the lumen 155, and is frictionally engaged with an appropriate frictional force. Also,
The distal end portion of the slider 129 and the insertion member 15 of the treatment tool 151
An operation wire 160 is connected to the tip of the second wire.

Then, the slider 129 is moved forward or backward by the actuator unit 156, so that the operation wire 160 can be pushed and pulled, so that the distal end portion of the insertion member 152 is bent or returned. Is able to.

FIG. 22A shows the seventh embodiment of the present invention. This is the endoscope 1 of the first embodiment.
The configuration of the drive means of the focus adjustment mechanism 4 of the observation optical system is changed. That is, in this embodiment, the first electrostrictive element 162 and the second electrostrictive element 163 are provided in the actuator unit 161.

The first electrostrictive element 162 and the second electrostrictive element 163 are arranged in front of and behind the connecting arm 11 of the lens frame 10 so as to sandwich the same.
The front end of the second electrostrictive element 163 and the rear end of the second electrostrictive element 163 are fixed to the connecting arm 11.

In addition, the lens frame 10 is provided with a first beam portion 10a protruding rearward of the connecting arm 11 and a second beam portion 10b protruding forward of the connecting arm 11. There is. In this case, the tip portion of the first beam portion 10a extends to the rear side of the guide hole 12 and the tip portion of the second beam portion 10b extends to the front side of the guide hole 12, and is slidably contacted with the lens barrel 7. There is. Note that lead wires 164 and 165 are attached to the first electrostrictive element 162 and the second electrostrictive element 163, and are connected to the external control unit 21 via the lead wires 164 and 165.

Further, a magnet 166 is attached to the lens barrel 7 of the endoscope 1.
Is inset. Due to the magnetic force of the magnet 166, the entire barrel 7 has a magnetic force, and the lens frame 10 is slidably attracted to and held by the barrel 7.

Next, the operation of the above structure will be described.
When the focus adjustment mechanism 4 of the observation optical system of the endoscope 1 is driven, the voltage of the isosceles triangular wave is applied to either the first electrostrictive element 162 or the second electrostrictive element 163 as shown in FIG. A waveform drive voltage is applied.

Here, the first electrostrictive element 162 shown in FIG.
When the voltage having the drive waveform shown in (B) is applied, the first electrostrictive element 162 expands and contracts as shown in FIG. 22 (C). Therefore, an impact force is generated in the first electrostrictive element 162 at a point where the directions of expansion and contraction suddenly intersect, and the lens frame 10 is stepwise moved to the right (forward direction) in FIG. When the voltage having the drive waveform shown in FIG. 22B is applied to the second electrostrictive element 163, the lens frame 10 moves to the left (rearward direction) in FIG. 22A.

Therefore, in the structure described above, the first electrostrictive element 162 and the second electrostrictive element 163 are provided in the actuator unit 161, and the first electrostrictive element is driven when the focus adjusting mechanism 4 is driven. 162 or second electrostrictive element 163
22B, a driving voltage having a voltage waveform of an isosceles triangular wave is applied to either one of them to move the lens frame 10 in the forward or backward direction. Unlike the case where the piezoelectric element 17 of the first embodiment is provided, the lens frame 1 of the focus adjusting mechanism 4 is obtained even with only one type of drive signal of the voltage waveform of the isosceles triangular wave.
A zero forward movement and a backward movement can be performed.

That is, since the piezoelectric element 17 of the first embodiment expands and contracts in proportion to the applied voltage, when a drive voltage having a triangular waveform is applied to this piezoelectric element 17, the expansion and contraction of the piezoelectric element 17 becomes a triangular wave. Therefore, the impact force generated when the piezoelectric element 17 is fully extended is the same as the impact force generated when the piezoelectric element 17 is fully contracted. Therefore, the impact force generated when the piezoelectric element 17 is fully extended and the impact force generated when the piezoelectric element 17 is fully contracted are offset, and the moving body 16 does not move as a whole. On the other hand, the electrostrictive elements 162, 1
In the case of 63, since it is displaced in proportion to the square of the applied voltage, there is a difference in the impact force generated when the electrostrictive elements 162 and 163 are fully expanded and when they are fully contracted. for that reason,
In this case, the moving body 16 can be moved as a total.

Further, FIG. 23A shows an eighth embodiment of the present invention. This is the endoscope 1 of the first embodiment.
The configuration of the drive means of the focus adjusting mechanism 4 of the observation optical system is further modified. That is, in this embodiment, the giant magnetostrictive material (alloy of rare earth metal and iron) 174 is provided in the actuator unit 171. Here, the magnetostrictive element is an element that expands or contracts when a magnetic field is applied to an alloy such as nickel, chromium, or cobalt, or an aluminum alloy. Further, among them, the giant magnetostrictive material is an alloy centered on rare earth elements, which has a strain amount of 1,000 to 10,000 times that of a general magnetostrictive element.

Further, in the actuator unit 171, a moving body 172 is provided at the lower end of the connecting arm 11 of the lens frame 10.
Is fixed. The moving body 172 is provided with beam portions 173a and 173b extending toward the front side. The beam portions 173a and 173b are slidably frictionally engaged with the inner peripheral surface of the lens barrel 7 of the endoscope 1. Further, the front end portion of the giant magnetostrictive material 174 is fixed to the rear end surface of the moving body 172.

Further, a drive pipe 175 for driving the giant magnetostrictive material 174 is arranged around the giant magnetostrictive material 174. The drive pipe 175 has a coil 177 wound around the outer peripheral surface of a pipe body 176 made of an alnico magnet. This coil 177 has a lead wire 178.
Is attached and connected to the external control unit 21 via the lead wire 178.

Next, the operation of the above configuration will be described.
When the focus adjusting mechanism 4 is driven, the actuator unit 1
When the drive voltage having the waveform shown in FIG. 23B or the drive voltage having the waveform shown in FIG. 23C is applied to the coil 177 of 71, the giant magnetostrictive material 174 expands or contracts rapidly.

When a drive voltage having the waveform shown in FIG. 23B is applied to the coil 177, the moving body 172 is given an impact force by the rapid deformation operation of the giant magnetostrictive material 174 at this time, and the lens frame is moved. 10 is slid and moved in the lens barrel 7 in the forward direction. In addition, FIG.
When the driving voltage having the waveform shown in FIG. 6 is applied, the moving force is applied to the moving body 172 by the rapid deformation operation of the giant magnetostrictive material 174 at this time, and the lens frame 10 slightly slides in the lens barrel 7 in the backward direction. To be done.

Therefore, in the structure described above, a giant magnetostrictive material 174 is provided in the actuator unit 171, and a drive pipe 175 arranged around the giant magnetostrictive material 174.
The coil 177 is driven by the giant magnetostrictive material 174 by applying the drive voltage having the waveform shown in FIG. 23 (B) or the drive voltage having the waveform shown in FIG. 23 (C). It is not necessary to attach the giant magnetostrictive material 174 in the actuator unit 171. Therefore, when the actuator unit 171 moves, the lead wire 178
Does not become a load, and there is no possibility that the lead wire 178 may fall off and become stuck.

Further, FIG. 24 shows a ninth embodiment of the present invention. This is a modification of the configuration of the power supply circuit 181 that supplies power to the piezoelectric element 17 of the actuator unit 13 of the first embodiment.

That is, the power supply circuit 181 is provided with a signal source 182, a transistor 183, a power supply voltage V ₀ , and a resistor 187. Furthermore, this power supply circuit 1
A series circuit 184 including a resistor 185 and a coil 186 is inserted between the output end of 81 and the piezoelectric element 17.

Then, in accordance with the operation of the transistor 183 that is turned on and off according to the signal output from the signal source 182, the power supplied from the power supply voltage V ₀ to the output terminal side through the resistor 187 is controlled. Further, the electric power (current × voltage) supplied from the output end to the piezoelectric element 17 via the series circuit 184 of the resistor 185 and the coil 186 is MA by the series circuit 184 of the resistor 185 and the coil 186.
The output of the actuator unit 13 (moving speed × load) is improved by adjusting so as to be X.

25 to 27 show the tenth aspect of the present invention.
FIG. FIG. 25 shows the configuration of the entire system of the image pickup device 191 for an endoscope. 193 is an endoscope, 192 is an external camera detachably connected to the endoscope 193, 194 is a camera control unit, 195 is a monitor.

An operation section 197 on the near side is connected to the proximal end of an insertion section 196 inserted into the body of the endoscope 193. A connecting cord 198 is detachably connected to the operating portion 197, and is connected to a light source device (not shown) through the connecting cord 198. Furthermore, this operation unit 197
An eyepiece 199 is provided at the end of the.

Further, the external camera 192 is provided with a connecting portion 201 with the endoscope 193 at the tip of the camera body 200. Then, the endoscope 193 is attached to the connecting portion 201.
The eyepiece part 199 is detachably connected.

Further, a connection cord 202 is connected to the base end of the camera body 200.
2 to the camera control unit 194. Furthermore, this camera control unit 1
94 is connected to the monitor 195. An endoscopic image taken by the external camera 192 is displayed on the monitor 195 via the camera control unit 194.

Further, in the lens barrel of the external camera 192, as shown in FIG. 26, a diaphragm mechanism 203 is arranged on the optical axis of the external camera 192. As shown in FIG. 27, the diaphragm mechanism 203 includes a rotary plate 204 and three diaphragm blades 2.
05 and are provided. In this case, the diaphragm blade 205 is connected to a fixed portion on the camera body 200 side so as to be rotatable about a rotation shaft 206. Further, the base end of each diaphragm blade 205 is rotatably connected to the rotary plate 204 via a connecting pin 207.

Further, a linear actuator 208 for opening and closing the diaphragm mechanism 203 is arranged around the lens holder of each lens 210 of the optical system so as to move back and forth in the optical axis direction of the external camera 192. One end of a coil sheath 209 is attached to this actuator 208. The other end of the coil sheath 209 is fixed to the rotary plate 204 of the diaphragm mechanism 203. The fixed point is arranged at a position displaced from the axial center of the actuator 208 in the circumferential direction of the rotary plate 204.

Next, the operation of the above configuration will be described.
First, when the diaphragm mechanism 203 is operated, the linear actuator 208 is driven back and forth. This actuator 208
The coil sheath 209 is pushed and pulled in accordance with the above operation. At this time, the fixed point between the coil sheath 209 and the rotary plate 204 is from the axial center of the actuator 208 to the rotary plate 2.
Since the coil sheath 209 is arranged at a position displaced in the circumferential direction, the rotating plate 204
Rotates by the force received from the coil sheath 209. Further, the rotation of the rotary plate 204 causes the aperture blades 205 to rotate about the rotation shaft 206, and the external camera 192.
The optical path of is opened and closed.

Therefore, in the structure described above, when the rotary plate 204 is rotationally driven by the linear actuator 208, the actuator 208 can be arranged parallel to the rotation axis of the rotary plate 204.
As compared with the case where 08 is arranged in the direction perpendicular to the rotation axis of the rotary plate 204, the increase in the aperture of the diaphragm mechanism 203 of the external camera 192 can be reduced, and the external camera 192 can be downsized as a whole. .

FIG. 28 (A) shows the essential structure of the stereoscopic rigid endoscope 221 according to the eleventh embodiment of the present invention. In this stereoscopic rigid endoscope 221, a proximal end portion of a rigid insertion portion 222 that is inserted into the body is provided with an operation portion 223 on the proximal side.
Are connected.

Furthermore, the stereoscopic rigid endoscope 221 has a pair of left and right relay optical systems 224a, 2 for stereoscopic observation.
24b and CCDs 225a and 225b for picking up the subject images transmitted by the respective relay optical systems 224a and 224b are provided to obtain left and right subject images with parallax.

Further, a pair of left and right relay optical systems 224a,
224b is built in the insertion part 222 of the stereoscopic rigid endoscope 221. These relay optical systems 224a, 224
The portion b is shielded from each other by a light shielding member (not shown).

FIG. 28B shows the inside of the operation section 223 on the hand side.
As shown in, a prism 226 is provided to reflect the left and right subject images transmitted by the relay optical systems 224a and 224b in the direction perpendicular to the optical axis thereof. Further, the operation unit 22
Mirrors 227a and 227b that reflect two subject images reflected by the prism 226 in a direction parallel to the optical axes of the relay optical systems 224a and 224b, and these mirrors 2
The images reflected by 27a and 227b are transferred to CCDs 225a and 22
An imaging lens (not shown) that forms an image on the exposure surface of 5b is built in. Peripheral circuits 228a and 228b are provided at the rear ends of the CCDs 225a and 225b.

The CCDs 225a and 225b convert the formed left and right subject images into electric signals, respectively, and output them to the control device 230 via the peripheral circuits 228a and 228b and the signal cable. .

Further, the stereoscopic rigid endoscope 221 has a built-in illumination optical system (not shown). Then, illumination light supplied from a light source device (not shown) is guided to the illumination window portion at the tip of the insertion portion 222 through this illumination optical system, and the subject is illuminated with the illumination light.

Further, the CCD 225 is provided in the control device 230.
Signal processing circuits 232a and 232b that perform processes such as γ correction on the electric signals output by a and 225b are provided. Each of the signal processing circuits 232a and 232b is A
/ D converter 233a, 233b, frame memory 234
a, 234b and D / A converters 235a, 235b are sequentially connected to the three-dimensional conversion processing circuit 236. The three-dimensional conversion processing circuit 236 is connected to the monitor 231.

Then, each of the signal processing circuits 232a, 232
Each video signal output from b is an A / D converter 233a,
After A / D conversion by 233b, each A / D conversion output is stored in the frame memories 234a and 234b for each frame. Furthermore, each frame memory 23
4a and 234b are read out from the respective signals and are D / A converted by the D / A converters 235a and 235b.
The outputs of the converters 235a and 235b are alternately displayed on the monitor 231 by the three-dimensional conversion processing circuit 236. At this time, the observer can observe the subject as a stereoscopic image by viewing the image on the monitor 231 through the light-shielding glasses. As a method for realizing stereoscopic vision, other than the method of alternately displaying left and right images on the monitor 231, a method of simultaneously displaying may be used.

Therefore, the controller 230 controls the CCD 22
5a, 225b, and each CCD 225a,
The electric signal output from 225b is subjected to signal processing, and the left subject image and the right subject image are alternately displayed on the monitor 231 for 30 times per second, for example. Then, the observer can observe the subject image displayed on the monitor 231 as a stereoscopic image by looking at the screen of the monitor 231 through light-shielding glasses (not shown). In this case, the light-shielding glasses are adapted to alternately shield the left and right in synchronization with the display image on the screen of the monitor 231. This is to give an observer a stereoscopic effect by utilizing the afterimage phenomenon, and since the left subject image and the right subject image transmitted by the two relay optical systems 224a and 224b have a parallax,
It can be observed as a stereoscopic image.

Further, the A / D converters 233a and 233b are connected to the image shift detection circuit 238 for detecting the shift amount between the left and right images via the contour extraction circuits 237a and 237b. The image shift detection circuit 238 is connected to memory control circuits 239a and 239b, a shift amount detection button 240 provided on the operation unit 223 of the endoscope 221, and an actuator control circuit 249 described later.

Then, the A / D converters 233a and 233b
A contour extraction circuit 237a from each video signal output from
The contour of the image is extracted by 237b, and the contour extraction circuit 237 is extracted by the image shift detection circuit 238.
a, 237b are compared to detect the amount of shift between the left and right images, and the memory control circuits 239a and 239b control the reading of the frame memories 234a and 234b in accordance with the output of the image shift detection circuit 238. It is like this.

Further, the image shift detection circuit 238 is used for the endoscope 2
When the shift amount detection button 240 of the operation unit 223 of No. 21 is turned on, the shift amount of the left and right images is detected. Then, the memory control circuits 239a and 239b use the frame memory 2 so that the amounts of misalignment between the left and right images match.
The reading order of the addresses 34a and 234b is controlled.

Here, the control device 230 may detect the deviation amount of the left and right images only once, or may detect the deviation amount of the left and right images again by the image deviation detection circuit 238. It may be possible to confirm that the displacement between the left and right images is within an appropriate range. If there is a deviation after confirmation, the amounts of misalignment of the left and right images are adjusted again. The frame memories 234a, 2
The display signals of the video signals read out from the monitor 34b are substantially coincident with each other on the monitor 231 and can be viewed by the observer as a stereoscopic subject image.

Further, the stereoscopic rigid endoscope 221 is shown in FIG.
As shown in FIG. 9, the left and right relay optical systems 224a, 224b
An auxiliary tilt angle adjusting mechanism 241 is provided for adjusting the auxiliary tilt angle θ which is an angle between the optical axes of the left and right incident lights respectively incident on the. The sub-angle adjusting mechanism 241 has an insertion portion 2
A pair of left and right prisms 242a and 242b are disposed on the respective optical axes of the binocular inside the observation window portion 222W on the front end surface of 22. The prisms 242a and 242b are attached to the mount 2
It is fixed to the inner ends of 43a and 243b. These mounting bases 243a and 243b are rotatably fixed to the fixed portion of the insertion portion 222 via support shafts 244a and 244b.

Further, one ends of the rods 245a and 245b are fixed to the outer ends of the mounting bases 243a and 243b via connecting rubbers 246a and 246b. To the other ends of the rods 245a and 245b, actuators 247a and 247b, which can move back and forth in parallel with the optical axis and have the same structure as the piezoelectric actuator of the first embodiment, are coupled. Further, each actuator 247a, 247b is connected to an actuator control circuit 249 via a lead wire 248a, 248b.

Next, the stereoscopic rigid endoscope 221 having the above structure.
The operation of the secondary helix angle adjusting mechanism 241 will be described. First, the images obtained from the left and right eyes of the stereoscopic endoscope 221 are signal-processed, and the image shift detection circuit 238 shifts the left and right images (if the shift amount is large, a good three-dimensional image is not obtained. ) Is detected and three-dimensionally imaged, and the data of the shift amount is obtained by the actuator control circuit 249.
Sent to.

The actuator control circuit 249 moves the actuators 247a and 247b back and forth based on the output signal from the image shift detection circuit 238. The mount 24 with the operation of each actuator 247a, 247b
3a and 243b are rotated about the support shafts 244a and 244b, and the prisms 242a and 242b are rotated in the arrow direction in FIG.

By changing the sub-angle θ in this way, the intersection of the optical axes of the incident lights of the left and right eyes of the endoscope 121 moves. At this time, the actuator control circuit 249 controls the operations of the actuators 247a and 247b so that the intersections of the optical axes of the left and right incident lights come to the position of the observation target (the intersection of the optical axes of the left and right incident lights is the position of the observation target). When it comes to, the amount of misalignment of each image on the left and right becomes minimal).

Therefore, in the case of the above-mentioned structure, it is possible to control by the sub-angle adjusting mechanism 241 of the stereoscopic rigid endoscope 221 so that the intersection of the optical axes of the left and right incident lights comes to the position of the observation target. Therefore, a good three-dimensional image can be obtained even if the distance between the observation target and the endoscope 221 changes.

FIG. 30 shows the twelfth embodiment of the present invention. This is a modification of the drive means of the focus adjusting mechanism 4 of the observation optical system of the endoscope 1 of the first embodiment. That is, in this embodiment, a substantially L-shaped moving body 252 is provided in the actuator unit 251. The horizontal portion 253 of the moving body 252 is provided with a first piezoelectric element 256 arranged in a direction perpendicular to the optical axis direction of the focus adjustment lens 9. The extension of the first piezoelectric element 256 causes the moving body 252 to more strongly frictionally engage with the lens barrel 7. The tip of the horizontal portion 253 of the moving body 252 is connected to the connecting arm 11 of the lens frame 10.
Are linked to.

Further, the vertical portion 255 connected to the rear end of the horizontal portion 253 of the moving body 252 has the second piezoelectric element 25 at the vertical portion 255.
7 is attached such that its expansion / contraction direction is parallel to the optical axis direction of the focus adjustment lens 9.

The first piezoelectric element 256 is the lead wire 2
It is connected via 58 to the first amplifier 260 shown in FIG. The first amplifier 260 is further connected to the phase shifter circuit 262 via the edge trigger circuit 261.

Further, the second piezoelectric element 257 is connected to the second amplifier 263 via the lead wire 259.
The second amplifier 263 is further connected to the phase shifter circuit 262 via the second piezoelectric element pulse circuit 264. In FIG. 32, (A) is a time chart showing the output of the second piezoelectric element pulse circuit 264, (B) the output of the phase shifter circuit 262, and (C) the output of the edge trigger circuit 261. is there.

Next, the operation of the above configuration will be described.
When the focus adjusting mechanism 4 of the observation optical system of the endoscope 1 is driven, the drive pulse (triangular wave or trapezoidal wave) of the second piezoelectric element 257.
On the other hand, a square wave pulse with an appropriately advanced phase is applied to the first piezoelectric element 256. As a result, the drive pulse adjusted so that the rising edge of the triangular wave (or the rising edge of the trapezoidal wave) and the rising edge of the square wave have substantially the same timing is the first piezoelectric element 256 and the second piezoelectric element 25.
7 and 7 respectively. Therefore, when the impact force of the second piezoelectric element 257 is applied to the moving body 252, the first
Since the piezoelectric element 256 contracts and the frictional force applied to the moving body 252 decreases, the impact force applied to the moving body 252 is not lost by friction, and the displacement amount of the moving body 252 can be increased.

Further, with the movement of the moving body 252 at this time, the lens 9 moves back and forth along with the lens frame 10 along the optical axis, and zooming and focusing of the observation optical system of the endoscope 1 are performed.

Therefore, even with the above-mentioned structure, the same effect as that of the first embodiment can be obtained, and the displacement amount of the moving body 252 when the focus adjusting mechanism 4 is driven can be further increased. The operation speed of zooming and focusing of the observation optical system of the endoscope 1 can be increased.

FIG. 33 shows the 13th embodiment of the present invention. This is a modification of the drive means of the focus adjusting mechanism 4 of the observation optical system of the endoscope 1 of the first embodiment. That is, in this embodiment, the hollow moving body 272 is provided in the actuator unit 271. A permanent magnet 274 is fitted in the moving body 272. The permanent magnet 274 has a lens frame 1
The coupling arm 11 of 0 is magnetically attracted and coupled.

Further, the moving body 272 has a piezoelectric element 273.
Is attached. Flexible cables 275a and 275b are connected to the piezoelectric element 273 with +/- poles of the piezoelectric element 273 by a conductive adhesive.

Further, the flexible cables 275a, 2
75b is a polyimide film 276 as shown in FIG.
A conductive wire made of a copper foil 277 is integrally molded on the top, and an electrode attachment portion 278 is formed at one end of the copper foil 277. Furthermore, each flexible cable 27
5a and 275b are formed in the initial shape of FIG.
Even when the actuator units 271 are folded by being moved, they are set so as not to interfere with each other as shown in FIG.

Next, the operation of the above configuration will be described.
When the focus adjusting mechanism 4 of the observation optical system of the endoscope 1 is driven, the moving body 272 frictionally engages with the lens barrel 7 by the action of the permanent magnet 274. Then, when a drive signal of a triangular wave or a trapezoidal wave is applied to the piezoelectric element 273, an impact force is applied to the moving body 272 and the moving body 272 slides, and at the same time, the lens 9 also moves to perform zooming and focusing.

Therefore, even with the above-mentioned structure, the same effect as that of the first embodiment can be obtained, and the lens frame 1
Since the work of attaching 0 to the moving body 272 can be saved, the actuator unit 271 can be easily assembled.

FIG. 36 shows a fourteenth embodiment of the present invention. This is a modification of the drive means of the focus adjusting mechanism 4 of the observation optical system of the endoscope 1 of the first embodiment. That is, in this embodiment, the contact electrodes 282a and 282b are conductively coupled to the +/- electrode surfaces of the piezoelectric element 17 of the actuator unit 281 respectively. The tip of each contact electrode 282a, 282b is a +/- electrode plate 283a, 283 provided in the lens barrel 7.
b respectively. Further, +/- lead wires are connected to the +/- electrode plates 283a and 283b, respectively.

FIG. 37 shows the actuator drive circuit 2
91 is shown. This actuator drive circuit 2
91 is provided with an astable multivibrator 292 to which a variable duty ratio resistor is connected. The astable multivibrator 292 has two (first and second)
One-shot vibrators 293 and 294 are connected.

Here, the first one-shot vibrator 293 is connected to the first contact of the second analog switch 297 via the first analog switch 295. The common contact of the second analog switch 297 is connected to the amplifier circuit 299 via the output switch 298. The amplifier circuit 299 is connected to the laminated piezoelectric element 17 via a lead wire.

In addition, the second one-shot vibrator 2
94 is connected to the second contact of the second analog switch 297 via the third analog switch 296.
The second analog switch 297 is connected to the waveform changeover switch 300, and the waveform changeover switch 3
The second analog switch 2 is interlocked with the 00 switching operation.
97 is adapted to be switched.

Next, the operation of the above configuration will be described.
The triangular pulse (V ₁ ) and the trapezoidal pulse (V ₂ ) for moving the actuator unit 281 forward or backward are shown in FIG.
As shown in 8, one-shot vibrator 293,29
Square switch pulse generated by 4 analog switch 29
5,296 are switched and the output is switched between 0V and 5V. At that time, it is created by integrating with an RC circuit attached.

In this case, the multivibrator 292 outputs a pulse having an arbitrary frequency. Square pulses are output from the one-shot vibrators 293 and 294 at the rising edge of the pulse, and the analog switches 295 and 296.
And an RC circuit in the vicinity thereof are shaped to form a triangular wave or a trapezoidal wave. In addition, the second analog switch 297
A triangular wave or a trapezoidal wave is selected by and is output to the amplifier circuit 299, and power is supplied from the amplifier circuit 299 to the piezoelectric element 17.

Also, the one-shot vibrator 293,
294 is triggered by the square wave pulse (MV) of the astable multivibrator 292. When the oscillation frequency of the astable multivibrator 292 is changed, the generation rate of triangular pulses or trapezoidal pulses per unit time is also changed, so that the moving speed of the actuator unit 281 is also changed.

Even if the frequency of the multivibrator 292 is changed, the rising and falling speeds of the waveforms output from the analog switches 295 and 296 and the RC circuit do not change, but the number of pulses per unit time changes. The moving speed of the actuator unit 281 changes. The trapezoidal pulse and the triangular pulse are switched by switching the voltage applied to the analog switch 297 with the switch 300.

Then, the actuator unit 281 is moved forward along the optical axis of the endoscope 1 by the above-mentioned operation,
Alternatively, the backward movement causes the focus adjustment mechanism 4 of the observation optical system to perform a zoom operation and a focus operation.

Therefore, in the structure described above, +/− in the piezoelectric element 17 of the actuator unit 281 is added.
Of the contact electrodes 282a and 282b are conductively coupled to the electrode surfaces of the contact electrodes 282a and 282b, respectively, and the tips of the contact electrodes 282a and 282b are +/- electrode plates 283a and 283b provided in the lens barrel 7.
The actuator unit 2
81 can be supplied with power without moving the lead wire.

Further, the actuator drive circuit 291
Then, the waveform changes as in the case where the driving frequency of the triangular wave or the trapezoidal wave is simply changed, and an appropriate impact force cannot be applied, or stress concentration occurs in the piezoelectric element 17 and the piezoelectric element 17 is destroyed. Therefore, the actuator unit 281 can be driven stably without any fear of being damaged.

FIG. 39 shows the fifteenth embodiment of the present invention. This is the operation unit 312 of the endoscope 311.
A donut-shaped fixing member 317 is attached to the outside of the channel tube 316 of the forceps plug 314 attached to the treatment instrument insertion port body 313 projecting from the above, and a cylindrical piezoelectric element 318 is attached to the fixing member 317. is there.

In this case, the fixing member 317 is the forceps plug 314.
It is fixed to the forceps plug body 315 of FIG.
A treatment tool 319 is inserted into the channel tube 316 so as to be slidable with respect to the channel tube 316.

Next, the operation of the above configuration will be described.
When an impact force is applied to the fixing member 317 by the piezoelectric element 318, slippage occurs between the channel tube 316 and the treatment tool 319. At this time, since the fixing member 317 returns to its original state due to the elastic force of the elastic material, the channel tube 316 and the treatment tool 319 frictionally engaged with the channel tube 316.
Also moves together. Therefore, the treatment instrument 319 finally moves inside the channel tube 316.

Therefore, in the case of the above structure, the treatment tool 319 can be automatically inserted into the endoscope 311 by only slightly inserting the treatment tool 319 into the forceps plug 314. Further, the insertion position of the treatment tool 319 can be finely adjusted. It should be noted that the present invention is not limited to the above-mentioned embodiments, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

[0177]

According to the present invention, since the actuator is formed only by the moving body slidably frictionally engaged with the base and the impact force generating portion coupled to the moving body, the number of components can be reduced. The cost of processing and assembling can be reduced, and the size of the whole can be reduced so that the impact force generating portion is less likely to be damaged when a mechanical impact is applied from the outside.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the configuration of a main part of a first embodiment of the present invention.

FIG. 2A is a side view showing an operation section of the endoscope,
FIG. 6B is a vertical cross-sectional view showing a focus adjustment mechanism incorporated in the distal end configuration portion of the insertion portion of the endoscope.

FIG. 3 is a perspective view showing a fixed state of a lead wire connected to a piezoelectric element.

FIG. 4A is a characteristic diagram showing a first drive waveform of a piezoelectric element, and FIG. 4B is a characteristic diagram showing a second drive waveform of a piezoelectric element.

FIG. 5A is an explanatory diagram for explaining the operation of the piezoelectric element driven by the first drive waveform, and FIG. 5B is a second diagram.
FIG. 6 is an explanatory diagram for explaining the operation of the piezoelectric element driven by the drive waveform of FIG.

6A is a schematic configuration diagram showing an experimental model regarding output characteristics of the actuator, FIG. 6B is a characteristic diagram showing drive waveforms when the actuator of FIG.
FIG. 6C is a characteristic diagram showing a drive waveform when the actuator of FIG.

FIG. 7A is a vertical cross-sectional view showing a main part configuration of a second embodiment of the present invention, and FIG. 7B is a vertical cross-sectional view showing a main part configuration of a modified example.

FIG. 8 is a vertical cross-sectional view showing the configuration of the main parts of the third embodiment of the present invention.

FIG. 9 is a vertical cross-sectional view showing the configuration of the main parts of a fourth embodiment of the present invention.

FIG. 10A is a vertical cross-sectional view of a main part showing a frictional engagement portion that applies a static frictional force between a lens barrel and a lens frame, and FIG. 10B is a first modification of the frictional engagement portion. A longitudinal sectional view of the main part shown,
(C) is a longitudinal cross-sectional view of an essential part showing a second modified example of the friction engaging portion, and (D) is a longitudinal cross-sectional view of the essential part showing a third modified example of the friction engaging part.

FIG. 11 is a vertical cross-sectional view showing the configuration of the main parts of a fifth embodiment of the present invention.

FIG. 12 is a vertical cross-sectional view showing the configuration of the main parts of a sixth embodiment of the present invention.

FIG. 13 is a vertical sectional view of a first modification of the actuator.

FIG. 14 is a schematic configuration diagram showing a drive circuit of the actuator of FIG.

15A is a characteristic diagram showing a first drive waveform of a piezoelectric element, FIG. 15B is a characteristic diagram showing a second drive waveform of a piezoelectric element, and FIG. 15C is a third drive waveform of a piezoelectric element. FIG.

16 is a schematic configuration diagram showing a modified example of the drive circuit of the actuator of FIG.

FIG. 17 is a vertical sectional view of a second modification of the actuator.

FIG. 18 is a schematic configuration diagram showing a drive circuit of the actuator of FIG.

FIG. 19 is a vertical cross-sectional view showing a third modified example of the actuator.

FIG. 20 is a vertical sectional view showing a fourth modified example of the actuator.

FIG. 21 is a vertical sectional view showing a fifth modification of the actuator.

FIG. 22 shows a seventh embodiment of the present invention,
(A) is a vertical cross-sectional view showing the configuration of the main part, (B) is a characteristic diagram showing the drive waveform of the actuator of (A), (C) is (A)
FIG. 6 is a characteristic diagram showing a state in which the electrostrictive element of the actuator of FIG.

FIG. 23 shows an eighth embodiment of the present invention,
(A) is a vertical cross-sectional view showing the configuration of the main part, (B) is a characteristic diagram showing a drive waveform when the actuator of (A) is moved forward, (C) is a drive waveform when the actuator of (A) is moved backward FIG.

FIG. 24 is a schematic configuration diagram of a main part showing a ninth embodiment of the present invention.

FIG. 25 is a perspective view showing the configuration of the entire system of an endoscope imaging apparatus showing a tenth embodiment of the present invention.

FIG. 26 is a vertical cross-sectional view showing the main configuration of an external camera.

FIG. 27 is a plan view showing the main configuration of the diaphragm mechanism of the external camera.

FIG. 28 shows an eleventh embodiment of the present invention,
(A) is a longitudinal cross-sectional view showing the main configuration of a stereoscopic rigid endoscope,
FIG. 3B is a schematic configuration diagram of a control device for a stereoscopic rigid endoscope.

FIG. 29 is a schematic configuration diagram for explaining a secondary angle of a stereoscopic rigid endoscope.

FIG. 30 is a vertical cross-sectional view showing the configuration of the essential parts of the twelfth embodiment of the present invention.

FIG. 31 is a schematic configuration diagram showing a control unit of an actuator.

FIG. 32 is a characteristic diagram showing a drive pulse output, a phase shifter output, and an edge trigger circuit output for the second piezoelectric element.

FIG. 33 is a vertical cross-sectional view showing the configuration of the main parts of the thirteenth embodiment of the present invention.

34 is a cross-sectional view taken along line L ₁ -L _{1 of} FIG.

FIG. 35 is a cross-sectional view of a flexible cable.

FIG. 36 is a longitudinal sectional view showing the structure of the main parts of the fourteenth embodiment of the present invention.

FIG. 37 is a schematic configuration diagram showing a drive circuit of an actuator.

FIG. 38 is a characteristic diagram for explaining the operating characteristics of the actuator.

FIG. 39 is a vertical cross-sectional view showing the main structure of a fifteenth embodiment of the present invention.

[Explanation of symbols]

3a ... Tip component main body (base), 7 ... Lens barrel (base), 16, 57 ... Moving body, 17, 58 ... Piezoelectric element (impact force generating section), 21 ... Control section, 56 ... Unit case (base) , 162 ... First electrostrictive element (impact force generating section), 163 ... Second electrostrictive element, 174 ... Giant magnetostrictive material (impact force generating section).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Yoshida 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An actuator comprising only a base, a moving body slidably frictionally engaged with the base, and an impact force generating portion coupled to the moving body.