JPH09192083A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability in the adjusting of a driving speed of an object to be driven provided on an endoscope. SOLUTION: In this endoscope apparatus which has an piezo-electric actuator 33 to drive an object to be driven provided on an endoscope, a drive circuit 34 to supply a drive power to the piezo-electric actuator 33, a control circuit 43 to control the driving of the piezo-electric actuator 33 with the drive circuit 34 and a switch 18 to supply a control signal to the control circuit 43, the control circuit 43 controls the drive circuit 34 to change the operation time of the switch 18 and the speed of the piezo-electric actuator 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope apparatus in which a driven body provided in an endoscope is driven by a piezoelectric actuator.

[0002]

2. Description of the Related Art Conventionally, as a piezoelectric actuator, for example, as disclosed in Japanese Patent Publication No. 4-52070, a moving member is frictionally engaged with a stationary member, and one end of a piezoelectric (electrostrictive) element is fixed to the moving member. There is proposed a structure in which an inertial body is fixed to the other end of the piezoelectric element. When a drive voltage is applied to the piezoelectric element, this piezoelectric actuator causes the moving body to move slightly with respect to the stationary member due to the shock caused by the abrupt expansion or contraction of the piezoelectric element, and then the piezoelectric element is restored to its original length by slow deformation. Back. By repeating this, the moving body with respect to the stationary member is moved.

This type of piezoelectric actuator is also used as a drive means for adjusting an optical system in an endoscope apparatus, as known from Japanese Patent Application Laid-Open No. 6-315282, for example. The piezoelectric actuator disclosed in Japanese Patent Laid-Open No. 6-315182 describes a volume for changing the driving speed of the piezoelectric actuator.

[0004]

However, in the above-described conventional example, since the volume for changing the speed is provided as a separate body from the drive on / off operation switch of the piezoelectric actuator, the piezoelectric actuator is operated by the on / off operation switch. Only when you try to operate, you can see that the speed is fast or slow. After that, the volume was adjusted to the desired speed, so the operability was very poor.

The present invention has been made in view of the above problems, and an object thereof is to improve the operability for adjusting the drive speed of a driven body provided in an endoscope.

[0006]

According to the present invention, there is provided a piezoelectric actuator for driving a driven body provided in an endoscope, a drive circuit for supplying drive power to the piezoelectric actuator, and the piezoelectric circuit provided by the drive circuit. In an endoscopic device having a control circuit for controlling the drive of a linear actuator and a switch means for supplying a control signal to the control circuit, the control circuit changes the speed of the piezoelectric actuator with the operation time of the switch means. The drive circuit is controlled as described above.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION

<First Embodiment> A first embodiment of the present invention will be described with reference to FIGS. The main points of this embodiment are as follows. It should be possible to adjust between auto speed and manual speed. When adjusting the auto speed, change the drive waveform so that the moving speed of the piezoelectric actuator increases for a certain time after the zoom operation switch is pressed. When adjusting the manual speed, the speed can be adjusted using the speed adjustment knob or the foot switch volume. There are three zoom operation switches: an operation section switch, a remote control switch, and a foot switch. The remote control switch must be hooked along the insertion part so that it can be moved. A means for releasing the catch when the stationary body and the moving body of the piezoelectric actuator are caught is provided.

(Structure) FIG. 1 schematically shows a system of a magnifying electronic endoscope (hereinafter referred to as an endoscope) 1. The endoscope 1 includes an insertion portion 2, an operation portion 3 and a universal cord 4. A connector 5 for connecting to a light source device 25 described later is provided at the extending end of the universal cord 4. The insertion portion 2 of the endoscope 1 includes a distal end portion 6, a bending portion 7 and a flexible tube portion 8 which are sequentially arranged from the distal end side.

A zoom cable 9 extends from the connector 5, and a zoom connector 10 is provided at the tip of the zoom cable 9. A connection cord 11 is connected to the zoom connector 10. When the connection cord 11 is not connected, the cap 10a is attached. The connection cord 11 is connected to the zoom connector 10 at one end.
A connector 12 is detachably connected to the
Another connector 13 is fixed to the other end. The connector 13 is detachably connected to a zoom control device 14 described later.

The zoom control device 14 includes a speed adjusting knob 1
5 are provided. Further, the zoom controller 14 is provided with a connection cord 17 to a foot switch 16 and a connection cord 19 to a seesaw type zoom remote controller switch 18 in a detachable manner.

Further, the connector 5 of the universal cord 4
Is a connector 2 provided at one end of the video cable 20.
1 is detachably connected. A connector 22 is provided at the other end of the video cable 20, and the connector 22 is connected to a camera control unit (hereinafter, referred to as a CCU) 2.
3 is detachably connected. The output image of the CCU 23 is displayed on the screen of the monitor 24 shown in FIG.

As shown in FIG. 2, the universal cord 4
The connector 5 is detachably connected to the light source device 25. The light source device 25 includes a lamp 26 for allowing illumination light to enter a light guide fiber 27 built in the endoscope 1.
And an air supply source (not shown) for supplying air to the air supply line and a water supply source for supplying water to the water supply line.

On the other hand, in the distal end portion 6 of the endoscope 1, an objective lens system 28 and an image pickup device, specifically a solid-state image pickup device, and more preferably a charge coupled device (hereinafter CCD) 29 are built in.
An image of a subject is taken.

A zoom lens 30 is provided on a part of the objective lens 28. The zoom lens 30 differs from a general so-called zoom lens in that the focal point changes when the magnification is changed. That is, for example, the depth of field is 5 to 100 mm on the wide angle side, and the depth of field is 2 to 5 mm on the enlargement side.

The image pickup signal of the CCD 29 is the preamplifier 3
1 is input to the signal processing circuit 32 in the CCU 23.

An actuator 33 for operating the zoom lens 30 is provided in the tip portion 6 of the endoscope 1. The actuator 33 is driven by receiving a drive signal from a drive circuit 34 provided in the zoom control device 14.

More specifically, the actuator 33 is composed of a piezoelectric actuator, and the actuator 33 moves the zoom lens 30 in the front-back direction of the optical axis via the connecting arm 35. This actuator 33 is configured as shown in FIG. That is, the zoom lens 3
The moving body 37 connected to the connecting arm 35 of 0 through the connecting member 36, and one end fixed to the moving body 37, the driving force of a predetermined waveform is applied to perform the expansion / contraction operation, and the movement is performed by the expansion / contraction operation. A piezoelectric element (including an electrostrictive element) 38 is provided as an impact force generation unit that applies an impact force to the body 37. The moving body 37 is held by being frictionally engaged with a base (stationary member) fixedly provided on the main body member of the tip portion 6, specifically, the inner surface of the circular pipe 39.

Here, the piezoelectric element 38 is formed by laminating piezoelectric members made of ceramics such as barium titanate, lead zirconate titanate, and porcelain, forming electrodes on them, and applying a direct current to the electrodes. It causes mechanical elongation deformation. The original piezoelectric element 38 is an element in which a distortion proportional to the electric field intensity is generated due to the reverse voltage effect, and the electrostrictive element is an element in which a distortion proportional to the square of the drive voltage is generated. It is called an element.

The movable body 37 is composed of a circular member that contacts the inner surface of the circular pipe 39, and a plurality of members that extend rearward at the outer peripheral portion of the member and elastically expand outwardly. Beam portions (leg portions) 40 of the above are projected. Projecting portions 40a are provided at the extending ends of the beam portions 40 to press against the inner surface of the circular tube 39.

The operation section 3 is provided with an actuator operation switch, more specifically, a seesaw type zoom switch 42. The output signal of the zoom switch 42 is input to a control circuit 43 provided in the zoom control device 14. The control circuit 43 instructs the drive circuit 34 on the type of drive waveform and the drive power of the actuator 33.

As shown in FIG. 2, the zoom switch 42 is of a seesaw type, and includes an enlargement (T) switch portion 42a having one mountain portion and a wide-angle (W) switch portion 42b having the other mountain portion. Equipped with. Then, by selectively operating each of the switch sections 42a and 42b, the actuator 33 moves the zoom lens 30 forward or backward in the optical axis direction accordingly, and the objective lens system 2
The zoom of 8 is performed. Moving body 37 of actuator 33
Moves back and forth in the optical axis direction of the objective lens system 28 integrally with the zoom lens 30 of the objective lens system 28.

The output signal of the foot switch 16 is input to the control circuit 43 via a photo coupler 44. Therefore, the foot switch 16 and the control circuit 43
The sides are electrically insulated. In addition, the foot switch 1
Reference numeral 6 includes an expansion (T) switch section 16a and a wide-angle (W) switch section 16b. Then, the switch parts 16a, 16
The actuator 33 is driven by selectively operating b, and the zoom lens 30 in the objective lens system 28 is moved forward or backward in the optical axis direction in accordance with the selected switch operation to perform a predetermined zoom. .

Similarly, the output signal of the remote control switch 18 is also input to the control circuit 43. The remote control switch 18 is also of a seesaw type, and includes an enlarged (T) switch portion 18a composed of one peak and a wide-angle (W) switch portion 18b composed of the other peak. The actuator 33 is driven by selectively operating each of the switch sections 18a and 18b, and the zoom lens 30 in the objective lens system 28 is moved forward or backward in the optical axis direction according to the selected switch operation. The predetermined zoom is performed.

As shown in FIG. 4, the remote control switch 18 is provided with an L-shaped hooking portion 46. The hooking portion 46 can be hooked on the flexible tube portion 8 of the endoscope 1 and can be moved. It is slidable in the axial direction of the flexible tube portion 8. The operator can grip the remote control switch 18 and the flexible tube portion 8 at the same time while selecting the mounting position of the remote control switch 18.

Manual zooming (that is, manual focusing) is possible by the switch means composed of the above switches 42, 16 and 18, respectively.

Next, a mechanism for performing auto zoom (that is, auto focus) will be described. CCU2
A focus detection circuit 45 is built in 3 and the image signal of the video signal processing circuit 32 is input to the focus detection circuit 45.
The focus detection circuit 45 calculates contrast data from the input image signal and inputs this data to the control circuit 43.

This auto-zoom (that is, auto-focus) control and the aforementioned manual zoom (that is,
Manual focus) control is selected by a selection switch (not shown). When the autofocus control is selected, the control circuit 43 controls the drive of the actuator 33 by moving the zoom lens 30 so that the contrast of an image is maximized by, for example, the contrast method (hill climbing method). That is,
The zoom lens 30 is moved so that the light receiving surface of the CCD 29 is always in focus. Therefore, the image displayed on the monitor 24 is always zoomed so as to be in focus.

Next, the moving speed adjusting mechanism of the actuator 33 will be described. The movement speed of the actuator 33 is performed by a manual method or an automatic method, and the selection of the method is selected by a manual speed adjustment / auto speed adjustment selection switch (not shown), and the speed adjustment method of the actuator 33 is set in the control circuit 43. It is specified.

First, when manual speed adjustment is selected, control is performed as follows. That is, the speed adjusting volume 1 provided on the foot switch 16
By operating 6c, the moving speed of the actuator 33 is manually adjusted. Therefore, the zoom speed of the lens 30 can be adjusted, and thus the zoom speed can be adjusted. Similarly, the zoom speed can be manually adjusted by the speed adjusting device knob 15 provided in the control device 14.

On the other hand, when the automatic speed adjustment is selected, the control is performed as follows. That is, the control circuit 43 controls the drive voltage waveform as shown in FIG. 5, for example. That is, the control circuit 43 causes the switch means, for example, the zoom switch 42 to be pressed for a certain period of time (T).
The drive circuit 3 causes the drive circuit 34 to output a drive waveform that increases the drive speed of the piezoelectric actuator 33.
4 is controlled. After that (after time T), the drive waveform is fixed so that the drive speed becomes constant. Further, when the zoom switch 42 is turned off, the application of the drive waveform is stopped at any time, and when the zoom switch 42 is pushed again, the piezoelectric actuator 3 is restarted from the slow state.
The operation of 3 is started.

In this case, the control circuit 43 controls the drive frequency (f) of the drive waveform applied to the piezoelectric element 38 of the piezoelectric actuator 33 so as to change with time.
Then, the piezoelectric element 38 of the actuator 33 repeats this with rapid expansion (contraction) and slow contraction (expansion) as one cycle, and advances and retreats together with the moving body 37 using the inertial force and impact force generated in each cycle. To do. As the drive waveform in this case, a triangular wave, a trapezoidal wave, a semicircular arc (for example, a sine curve) waveform, or the like as shown in the above-mentioned prior art can be used. The drive waveforms are different when the drive operation direction is the forward direction and the reverse direction, and are usually in the inverted form.

The number of times the piezoelectric element 38 expands and contracts per unit time corresponds to the drive frequency of the actuator 33. In principle, the moving speed increases as the drive frequency increases. For example, in the waveform of FIG. 5, the drive frequency gradually increases during the elapsed time T from the time when the zoom switch 42 is pressed (T1>T2>
T3 ...> Tn, f1 <f2 <f3 ... <fn,) and therefore the operating speed of the piezoelectric actuator 33 increases. The peaks of the drive voltage of each pulse in the waveform of FIG. 5 are made equal and the drive frequency is changed. Further, the drive frequency may be changed not only for each pulse but for any number of pulses.

By the way, a means for canceling the catch when the circular tube 39 and the moving body 37 are caught in the actuator 33 for some reason and cannot be moved will be described below. This is configured to be performed by the control of the drive circuit 34. For this reason, the drive circuit 34 has a hook release drive circuit as shown in FIG. That is, a full-wave rectified wave generation circuit 52 that outputs a full-wave rectified waveform having a frequency equal to the longitudinal resonance frequency f _R of the piezoelectric element 38 forming the actuator 33, which is arranged in parallel with each other in the drive circuit 34, A full-wave rectified wave generating circuit 51 that outputs a full-wave rectified waveform having a frequency f _O that is sufficiently lower than the frequency f _R , and analogs that intervene in the output lines S1 and S2 of both full-wave rectified wave generating circuits 51 and 52, respectively. Amplifiers 55 and 56 for amplifying the output waveforms of the switches 53 and 54 and the analog switches 53 and 54 to the drive voltage level of the piezoelectric element 38, respectively.
And their outputs are connected to each other, and a resistor 57 for detecting an injection current to the actuator 38, which is interposed in the integrated signal line S8, is provided as a main element. One end of the resistor 57 is + of the piezoelectric element 38.
Connected to electrodes.

Here, both of the analog switches 53,
The switch signal S4 output from the switch control circuit 43a in the control circuit 43 is input in parallel to the control terminal for controlling the switching operation of 54. Further, both ends of the resistor 57 described above are connected to one input end of a current detection / comparison circuit 58 for detecting an injection current to the piezoelectric actuator 33 and comparing it with a reference value. The reference signal S7 for comparison is input to one input terminal of the current detection / comparison circuit 58.

The output signal of the current detection / comparison circuit 58 is input to the clock terminal of the one-shot multivibrator 59, and the output signal S of the one-shot multivibrator 59 is input.
Reference numeral 3 is connected to a control input terminal of a relay 60 which controls the supply of high voltage power to both amplifier circuits 55 and 56. The two output contacts of the relay 60 are respectively connected to the high voltage power supply terminals of the amplifier circuits 55 and 56.

The current detection / comparison circuit 58 and the one-shot multivibrator 59 are connected to the control circuit 43.
It is built in.

(Operation) First, the case where the manual zoom and the automatic speed adjustment are selected will be described. It is assumed that the operator presses any one of the foot switch 16, the remote control switch 18, and the zoom switch 42. Hereinafter, for simplicity, the description will be made by pressing the zoom switch 42. The drive voltage waveform as shown in FIG. 5 (only the waveform in the forward direction is shown in FIG. 5) is applied to the actuator 33. Then, the actuator 33 is driven, the moving body 37 moves back and forth, and the optical system (zoom lens, focus lens) 30 connected to the moving body 37 via the connecting member 36 moves. The operator has the zoom switch 42
When turned off, the application of the drive voltage to the actuator 33 is stopped, and the operation of the actuator 33 is stopped.

The control circuit 43 controls the drive circuit 34 to output a drive waveform that increases the operation speed of the piezoelectric actuator 33 for a certain period (T) after the zoom switch 42 is pressed. After that (after time T), the drive waveform is fixed so that the speed becomes constant.
When the zoom switch 42 is turned off, the application of the drive waveform is stopped at any time, and the zoom switch 42 is turned on again.
When is pressed, the operation of the actuator 33 starts again from the slow speed state.

The control circuit 43 controls the frequency (f) of the drive signal so as to change with time. The piezoelectric element 38 of the actuator 33 repeats rapid expansion (contraction) and slow contraction (expansion), and advances and retreats by utilizing the inertial force and impact force generated in each cycle. The number of expansions and contractions per unit time corresponds to the drive frequency of the actuator 33, and in principle, as the drive frequency increases, the moving speed increases. Therefore, in the waveform of FIG. 5, the driving frequency gradually increases during the time T after the zoom switch 42 is pressed, and the driving speed of the actuator 33 increases.

Since the moving speed of the moving body 37 of the actuator 33 has a frequency characteristic, the moving speed does not always increase when the driving frequency is increased. In such a case, however, the frequency increases as the frequency increases. Just select the band. On the contrary, it is possible to select a frequency band in which the speed is increased when the driving frequency is lowered, and the driving frequency is lowered with time when the operation switch is pressed. Of course, the drive frequency may be continuously changed as described above, but the drive frequency may be changed every several pulses.

Next, the case where the manual zoom and the manual speed adjustment are selected will be described. The operator operates the zoom switch 42. At this time, when it is desired to change the zoom speed, the speed adjusting knob 15 or the speed adjusting volume 16c of the foot switch 16 is operated. Thus, a desired zoom speed (actuator movement speed) can be obtained.

Next, a case where the auto zoom (that is, auto focus) is selected will be described. The operator inserts the insertion portion 2 of the endoscope 1 into the body cavity. At this time, zooming and focusing are automatically performed according to the distance to the subject. That is, when the distance to the subject is large, the angle is wide, and the closer to the subject, the larger the distance. Then
Focusing is always performed regardless of the distance to the subject.

Further, in the actuator 33, when the moving body 37 is caught by the circular tube 39, it operates as follows. This will be described with reference to FIGS. 6 to 8. First, when the zoom control device 14 is powered on, the full-wave rectified wave generation circuits 51, 52 are
Outputs the full-wave rectified waveforms S1 and S2 continuously as shown in FIGS. 7 (a) and 7 (b).

Here, the full-wave rectified waveform S2 has a frequency equal to the longitudinal resonance frequency f _R of the piezoelectric element 38 in the actuator 33, and one full-wave rectified waveform S1 is the piezoelectric element 3
8 no fear of breakage of, moreover, the moving speed is set to a frequency f _O of the maximum (sufficiently smaller than the resonance frequency) of the actuator 33.

Therefore, the zoom remote control switch 1
8 or the foot switch 16 or the zoom switch 42 for the operating section of the scope 27, for example, when the zoom switch 42 is pressed (t = t0), the switch signal line S4 changes to "H" level, In conjunction with this, the analog switches 53 and 54 become conductive, and the full-wave rectified waveform signals S1 and S2 are input to the amplifier circuits 55 and 56.
Here, the relay 60 controls the control signal S of the relay 60.
When 3 is at "L" level, switching is performed so that only the amplifier circuit 55 is supplied with high voltage power when only at "H" level.

Now, before any one of the switches 16, 18, 42 is pushed, the one-shot multivibrator 59
Output S3 is preset to "H" level. Here, when the zoom switch 18 is pressed, if the moving body 37 of the actuator 33 and the circular tube 39 do not bite, the current injected into the actuator 33, that is, the current flowing through the resistor 57, drives the actuator 33. Since the voltage is sufficiently large and the voltage across the resistor 57 exceeds the level of the reference voltage signal S7, the output of the current detection / comparison circuit 58 remains at the "H" level and does not change, and the one-shot multivibrator 59 is present. Does not operate, the control signal S3 of the relay 60 remains at "L" level.

Therefore, since the high-voltage power is supplied only to the amplifier circuit 55, the output of the amplifier circuit 55, that is, the energization waveform S8 to the actuator 33, shows the amplified frequency f _O as shown in FIG. 7 (g). It becomes a full-wave rectified waveform.

On the other hand, if the biting phenomenon already occurs when t = t0, the operation described later
The bite is released. Each of the switches 18, 1
When the beam portion (leg portion) 40 of the moving body 37 of the actuator 33 is engaged with the inner surface of the circular pipe 39 while pressing 6, 42, the actuator 33 is stopped (t = t1). It is conceivable that the injection current to the actuator 33 is reduced by changing the resonance state of the entire system of the actuator 33 and increasing the impedance value of the actuator at the current drive frequency f _O.

Here, as shown in FIG. 7 (h), the injection current has a form in which the energization voltage waveform S8 is differentiated with respect to time, and at the discontinuity point of the full-wave rectified wave, the injection current rapidly changes from the minimum value to the maximum value. To do. Now, as shown in FIG. 7 (g), when the injection current level falls below the level of the reference voltage S7 due to the decrease of the injection current, the output of the current detection / comparison circuit 58 changes from "H" to "L". At the moment, the output S3 of the one-shot multivibrator 59 becomes "H", and the relay 6
0 is switched to supply high voltage power to the amplifier circuit 56 side.

At this time, the energization waveform S8 changes to a full-wave rectified wave of the frequency f _R , and the impedance of the piezoelectric element 38 greatly decreases at the frequency of the energization waveform as shown in FIG. Therefore, the injection current to the actuator 33 increases, so that the generated force of the actuator 33 greatly increases to a level at which the engagement with the circular tube 39 can be released. At this time, the energization time of the full-wave rectified wave of frequency f _R is
In order to prevent breakage of the piezoelectric element 38, the one-shot multivibrator 59 is set so as to be limited to about several pulses. In order to cancel the bite phenomenon, a full-wave rectified wave having a larger amplitude than usual may be applied to the actuator 33 in addition to the above waveform.

When the bite state is released (t = t2) and the injection current returns to the normal level, the injection current value exceeds the level of the reference voltage S7, so the output of the one-shot multivibrator 59 becomes "L" again. The relay 60 is switched to the amplification circuit 55 side again to energize the actuator 33 with the full-wave rectified wave of the frequency f _O.

By the above operation, the actuator 33
However, even if the moving body 37 and the circular tube 39 are stopped due to biting, the energization waveform that gives a large generative force for releasing the biting state can be automatically output to release the biting state.

(Effect) If the operator often turns off the operation switch within a certain time T, the operation speed of the actuator 33 does not reach the maximum, and the actuator 33 can be finely operated. Therefore, the zoom lens, the focus lens, and other precision positioning tables can be finely moved, and the operator can easily adjust the magnification, focus, position, etc. desired by the operator.

When it is desired to roughly move and roughly determine the enlargement ratio, focus, and position, the operation switch is pressed for a certain time T or more, and the maximum speed of the actuator 33 is reached.
The zoom lens, focus lens, and precision positioning table can be moved. Therefore, the operator can easily coarsely move the lens and the positioning table to a desired position.

Since the operation speed of the actuator 33 can be changed by the speed adjusting volume 16c of the foot switch 16, the speed can be adjusted with the foot while operating the zoom with the hand, and the operability is good. The operability is good because the zoom can be operated with multiple switches.

Since the remote control switch is provided, it can be operated by a person other than the operator, and is most suitable for education, for example.

Since the remote control switch 18 is provided along the insertion portion 2 of the endoscope 1, the operator can perform the forward / backward movement and the zoom operation of the insertion portion with the right hand while performing the bending operation with the left hand, and the operability is good.

The circular tube 39 of the actuator 33 and the moving body 3
When you get caught in 7, you can automatically release the catch. Therefore, the stable operation of the actuator 33 becomes possible.

<Second Embodiment> A second embodiment of the present invention will be described with reference to FIG. (Structure) This second embodiment is different from the first embodiment described above in the way of controlling the drive circuit 34 by the control circuit 43. That is, the method of automatic speed adjustment is different.

In this embodiment, the output drive voltage of the drive circuit 34 is controlled so as to change with time, and the drive circuit 34 is controlled by the control circuit 43. The amount of force generated by the piezoelectric element 38 used for the actuator 33 is proportional to the voltage applied to the piezoelectric element 38. As a result, when the voltage applied to the actuator 33 is gradually increased, the generated force of the piezoelectric element 38 increases and the actuator 33
The moving speed of the moving body 37 is increased. This is used for speed adjustment.

The drive voltage of the drive circuit 34 increases until a certain time (T) after the zoom switch 42 is pressed, and then the drive waveform is fixed so that the drive speed of the actuator 33 becomes constant. . At this time, the drive frequency of the drive circuit 34 is kept constant. The voltage change does not have to be sequentially changed for each pulse, but may be changed for any number of pulses. Further, the drive circuit 3 is combined with the drive voltage waveform (FIG. 5) in the first embodiment described above, and the drive circuit 3 is operated after the operation switch is pressed.
The drive frequency and drive voltage of No. 4 may be changed with time, and the drive speed of the actuator 33 may be increased.

(Function and Effect) According to this embodiment, the same function and effect as those of the above-described first embodiment can be obtained.

<Third Embodiment> A third embodiment of the present invention will be described with reference to FIG. (Structure) This third embodiment differs from the first embodiment described above in the way of controlling the drive circuit 34 by the control circuit 43. That is, the method of automatic speed adjustment is different.
In this embodiment, the number of waves of the output drive voltage waveform of the drive circuit 34 is controlled so as to be changed at regular intervals (Ti).

The moving distance of the actuator 33 is determined by the number of waves of the drive voltage waveform applied. When the number of drive waveforms applied within the time Ti increases, the distance that the moving body 37 moves within the time Ti increases, and the actuator 33
The average speed of the moving body 37 is increased. Since the drive frequency of the drive circuit 34 is as high as several kHz, the movement of the actuator 33 is not intermittent but very smooth.

After a certain time T, the number of drive waveforms applied within the time Ti is fixed, and the control circuit 43 controls so that the moving speed of the actuator 33 becomes constant.
The movement of the zoom lens 30 attached to the actuator 33 gradually increases during the time T after pressing the zoom switch 42, and when the time T is exceeded, the zoom lens 30 moves at a constant speed.

(Function and Effect) According to this embodiment, the same function and effect as those of the above-described first embodiment can be obtained.

<Fourth Embodiment> A fourth embodiment of the present invention will be described with reference to FIGS. 11 and 12. (Structure) The fourth embodiment is different from the above-described first embodiment in the way of controlling the drive circuit 34 by the control circuit 43. In the first embodiment described above, when the moving body 37 is caught by the circular tube 41 of the piezoelectric actuator 33, the catch is automatically released, whereas in this embodiment, the release switch 65 is used to catch the catch. Is to be released.

The structure will be described with reference to FIG.
The drive circuit 34 is arranged in parallel with each other, and is provided to the full-wave rectified wave generation circuit 51 of frequency f _O , the full-wave rectified wave generation circuit 52 of frequency f _R , and the output lines S1 and S2 of both circuits 51 and 52, respectively. An amplifier circuit 6 for amplifying the output waveforms of the intervening analog switches 61 and 62 and the analog switches 61 and 62 to the drive voltage level of the piezoelectric element 38, respectively.
A signal line S15, which is mainly composed of 3 and 64, outputs of both amplifier circuits 63 and 64 are connected to each other and is unified, is connected to the + electrode side of the actuator 33.

Here, the switch signal line S9 output from the switch control circuit 43a in the control circuit 43 is connected to the control terminal for controlling the switching operation of the one analog switch 61, and the other analog switch. The control terminals of 62 are provided with zoom switches 18, 16,
A switch signal line S10 output from the bite release switch control circuit 43b whose output voltage level changes in conjunction with the on / off operation of the bite release switch 65 provided separately from 42 is connected.

Further, the output terminal of the relay 66 for controlling the supply of the high voltage power source is connected to the high voltage power source input terminal of one of the amplifier circuits 63, and the switch signal line S9 is connected to the control terminal of this relay 66. To be done. The other amplifier circuit 64
The output terminal of another relay 67 is connected to the high voltage input terminal of. The ANDIC circuit 69 is connected to the control terminal of the relay 67.
The output signal terminal S12 of is connected. ANDIC circuit 6
Reference numeral 9 obtains a logical product of the signal of the switch signal line S10 and the output S11 of the one-shot multivibrator 68 which operates by using the signal of the switch signal line S10 as a clock and outputs a signal. The one-shot multivibrator 68 and the ANDIC 69 are built in the control circuit 43. The other points are the same as those of the first embodiment described above.

(Operation) The operation of this embodiment will be described with reference to FIGS.
2 will be described. First, at time t = t0, when any one of the zoom switches 18, 16 and 42 of the switch means is pressed, the signal S9 becomes "H" level, the analog switch 61 becomes conductive and the amplifier circuit 63 is connected. Is input with the full-wave rectified wave signal S1 of frequency f _O. Here, the relay 66 is switched so that the high voltage power is supplied only to the amplifier circuit 63 when the control signal S9 is at "H" level. Therefore, at this moment, the amplifier circuit 63 operates and the actuator 33 is amplified. The full-wave rectified wave S15 having the frequency f _O is energized.

The operator selects each zoom switch 18, 16,
When the bite of the actuator 33 is detected by stopping the image on the monitor 24 while pressing any one of the switches 42, the zoom switches 18, 1
When pressing 6, 42 is stopped (time t = t1) and the button of the bite release switch 65 is pressed (time t = t2), the switch signal S10 becomes "H" level, so that the analog switch 62 becomes conductive. , The amplifier 64 has a frequency f
The full-wave rectified wave S2 of _R is input, but at the same time, the one-shot multivibrator 68
Operates, and only for the time of the pulse width of its output pulse S11,
Relay 6 to supply high voltage power only to amplifier circuit 64
The waveform S15 that is switched between 7 and energized the actuator 33 becomes a full-wave rectified wave of the amplified frequency f _R.

Here, the pulse width of the output S11 of the one-shot multivibrator 68 is set to be limited to a few pulses of the energizing waveform S15 in order to prevent the piezoelectric element 38 from being broken. This short-time energizing pulse is applied to the piezoelectric element 38.
Since the resonance frequency is equal to the resonance frequency of, the actuator 33 can be provided with a large generated force capable of releasing the bite.
In addition to this waveform, a waveform having a larger amplitude than usual may be energized in order to release the bite.

As described above, when the bite is released,
Stop pressing the button of the bite release switch 65 (time t = t3), and switch the zoom switches 18, 16 and 4 again.
By pressing any one of the two (time t = t4), the energization waveform S15 to the actuator 33 returns to the full-wave rectified wave of the frequency f _O , and the normal zooming operation is resumed.

(Effect) According to this embodiment, the bite of the actuator 33 can be easily released, and the stable operation of the actuator 33 becomes possible.

<Other Embodiments> The present invention is not limited to the above embodiments. For example, the actuator need not be a piezoelectric actuator. Further, the driven body driven by the actuator is not limited to the lens, and may be the one described below. Further, it can be applied to products other than endoscopes. In addition, the foot switch 16 and / or the remote control switch 18 is set to C of the endoscope 1.
A switch for storing or instructing to store the captured image of the CD 29 electronically or by another method may be added.

Instead of the slide type volume control 16c provided on the foot switch 16, a stepping type foot pedal may be used. It does not have to be autofocus. The speed of the actuator 33 may be displayed on the monitor 24. The monitor 24 may display a selection state of auto zoom / manual zoom. The monitor 24 may display a selection state of automatic speed adjustment / manual speed adjustment.

[Additional Notes] (1st group) (1) A piezoelectric actuator for driving a driven body provided in an endoscope, a drive circuit for supplying drive power to the piezoelectric actuator, and the drive circuit for driving the piezoelectric actuator. In an endoscope apparatus having a control circuit for controlling the drive of the piezoelectric actuator and a switch means for supplying a control signal to the control circuit, the control circuit changes the speed of the piezoelectric actuator with the operation time of the switch means. An endoscope apparatus characterized in that the drive circuit is controlled so as to perform the above-mentioned operation. (2) The endoscope apparatus according to item 1, wherein the driving frequency is changed with time to adjust the speed. (3) The endoscope apparatus according to item 1, wherein the control of the drive circuit by the control circuit adjusts the speed by changing the drive voltage with time. (4) The endoscope apparatus according to item 1, wherein the control of the drive circuit by the control circuit adjusts the speed by changing the number of waves of the drive waveform. (5) The endoscope apparatus according to item 1, wherein the driven body is at least a part of an optical element of an objective optical system arranged at a tip portion of the endoscope insertion portion. (6) The endoscope apparatus according to item 1, wherein the driven body is a zoom lens arranged at a tip portion of the endoscope insertion portion. (7) The endoscope apparatus according to item 1, wherein the driven body is a focus lens disposed at a tip end portion of the endoscope insertion portion. (8) The endoscope apparatus according to item 1, wherein the driven body is a visual field conversion lens arranged at the tip of the endoscope insertion portion. (9) The endoscope apparatus according to item 1, wherein the driven body is a solid-state image pickup element arranged at a tip end portion of an endoscope insertion portion. (10) The endoscope apparatus according to item 1, wherein the driven body is a forceps raising base arranged at a distal end portion of the endoscope insertion portion. (11) The endoscope apparatus according to item 1, wherein the driven body is an illumination lens arranged at a tip portion of the endoscope insertion portion. (12) The endoscope apparatus according to item 1, wherein the driven body is an air supply nozzle arranged at a tip portion of the endoscope insertion portion. (13) The endoscope apparatus according to item 1, wherein the driven body is a water supply nozzle provided at a tip end portion of the endoscope insertion portion. (14) The endoscope apparatus according to item 1, wherein the driven body is a diaphragm provided in a part of an optical system arranged at a tip portion of the endoscope insertion portion. (15) The endoscope apparatus according to item 1, wherein the driven body is a precision positioning table.

(Group 2) (1) An actuator for driving a driven body provided in the endoscope, a drive circuit for supplying drive power to the actuator, and control of driving of the piezoelectric actuator by the drive circuit In the endoscopic device having a control circuit for operating the control device, speed control operation means for varying the drive speed of the actuator is connected to the control circuit. (2) The endoscope apparatus according to item 1, wherein the speed varying operation means is provided in an operation section of the endoscope. (3) The endoscope apparatus according to item 1, wherein the speed varying operation means is provided separately from the endoscope. (4) The endoscope apparatus according to item 1, wherein the variable speed operation means is provided in an apparatus having a drive circuit and a control circuit. (5) The endoscope apparatus according to item 1, wherein the variable speed operation means is detachably provided in an apparatus having a drive circuit and a control circuit. (6) The endoscope apparatus according to item 1, wherein the speed varying operation means is a foot pedal. (7) The endoscope apparatus according to item 1, wherein the variable speed operation means is a slide volume provided on a foot switch. (8) The endoscope apparatus according to item 1, wherein the actuator is a piezoelectric actuator.

(Group 3) (1) An actuator for driving a driven body provided in the endoscope, a drive circuit for supplying drive power to the actuator, and a control circuit for controlling the drive of the drive circuit, An endoscope apparatus having control switch means for supplying a control signal to the control circuit, wherein the switch means is provided separately from the endoscope. (2) The endoscope apparatus according to item 1, wherein the switch means is provided along the insertion portion of the endoscope so as to be slidable in the axial direction of the insertion portion. (3) The endoscope device according to item 1, wherein the switch means is a foot switch. (4) The endoscope device according to item 1, wherein the switch means is insulated by a photocoupler. (5) The operation section of the endoscope is provided with a switch means other than the switch means, and the movement of the piezoelectric actuator can be controlled by both switch means. Mirror device. (6) The endoscope apparatus according to the first item, wherein the actuator is a piezoelectric actuator. (7) The switch means is further provided with a switch for storing or instructing to store an image picked up by an image pickup device provided in the insertion portion of the endoscope electronically or by another method. Endoscope device.

(Fourth Group) (1) In a drive circuit for a piezoelectric actuator, a first drive state for driving the piezoelectric actuator and a strong generated force in the piezoelectric actuator from the first drive state An endoscope apparatus having a second drive state and a selection means for selecting the first drive state and the second drive state. (2) The endoscope apparatus according to item 1, wherein the first drive state is a normal drive state. (3) The piezoelectric actuator includes only a circular tube, a moving body slidably frictionally engaged with an inner surface of the circular tube, and an impact force generating portion coupled to the moving body.
Endoscope device. (4) The endoscope apparatus according to item 1, wherein the impact force generating portion is a piezoelectric element. (5) The endoscope apparatus according to item 1, wherein the second driving state is driven by a sine wave having a resonance frequency of the piezoelectric element. (6) The endoscope apparatus according to item 1, wherein the drive voltage in the second drive state is higher than the drive voltage in the first drive state. (7) The selection means selects the first state or the second state according to the output of the means for detecting that the circular tube and the moving body are caught, Mirror device. (8) The selection means selects the first driving state when the circular tube and the moving body are not caught, and selects the second driving state when the moving body is caught. Endoscopic device. (9) The endoscope apparatus according to item 1, wherein the selection means is a release switch. Needless to say, the respective items in the above-mentioned additional notes may be combined in any manner. (Prior art example and object for supplementary second group) JP-A-6-315
According to Japanese Patent No. 282, there is a volume that changes the speed of the piezoelectric actuator, but the configuration of the volume that changes the drive speed of the piezoelectric actuator is not specific and is not taken into consideration, so the operability was very poor. Therefore, it is an object of the supplementary second group to improve operability.

(Conventional Example and Purpose for Supplementary Group 3) In Japanese Patent Laid-Open No. 6-315282, there is a switch for instructing the moving direction of the piezoelectric actuator, but the configuration of the switch for instructing the driving direction of the piezoelectric actuator is concrete. The operability was very poor because it was not considered. Therefore, it is an object of the supplementary third group to improve operability.

(Prior Art Example and Objective for Supplementary Group 4) In Japanese Patent Application Laid-Open No. 6-315282, the friction state between the circular tube and the moving body changes while the piezoelectric actuator is being driven, causing a catch and sudden stop. I had to do it. At this time, the drive pulse generated in the conventional drive circuit cannot release the catch because the force generated by the piezoelectric actuator is small. Therefore, the objective of the supplementary fourth group is to enable the hook to be released.

[0084]

As described above, according to the present invention, it is possible to automatically adjust the driving speed of the driven body provided in the endoscope and improve its operability.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a system of a magnifying electronic endoscope according to a first embodiment.

FIG. 2 is an explanatory diagram showing a configuration of an electric circuit of the system of the magnifying electronic endoscope according to the first embodiment.

FIG. 3 is a sectional view of an actuator portion that drives an objective optical system of the magnifying electronic endoscope.

FIG. 4 is an explanatory view of a mounted state of a remote control switch mounted on the endoscope.

FIG. 5 is a waveform diagram of a driving voltage for driving the actuator.

FIG. 6 is an explanatory diagram showing a configuration of a hook release driving circuit incorporated in the driving circuit of the electric circuit.

FIG. 7 is a waveform diagram of another drive voltage for driving the actuator.

FIG. 8 is a waveform diagram showing a change in impedance of the piezoelectric element by the hook release driving circuit.

FIG. 9 is a waveform diagram of a driving voltage for driving an actuator according to the second embodiment.

FIG. 10 is a waveform diagram of a driving voltage for driving an actuator according to the third embodiment.

FIG. 11 is an explanatory diagram showing a configuration of an electric circuit according to a fourth embodiment.

FIG. 12 is a waveform diagram of a driving voltage for driving an actuator according to the fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope 14 ... Zoom control device 16 ... Foot switch 18 ... Remote control switch 23 ... CCU 24 ... Monitor 28 ... Objective lens system, 29 ... CCD 30 ... Zoom lens 32 ... Signal processing circuit 33 ... Actuator 34 ... Drive circuit 37 ... Moving body 38 ... Piezoelectric element 39 ... Circular tube 42 ... Zoom switch 43 ... Control circuit 51, 52 ... Full wave rectified wave generation circuit 52 ... Full wave rectified wave generation circuit 61, 62 ... Analog switch 63, 64 ... Amplification circuit 65 … Release switch 66… Relay 68… One-shot multivibrator 69… ANDIC circuit

Claims (1)

[Claims] 1. A piezoelectric actuator for driving a driven body provided in an endoscope, a drive circuit for supplying drive power to the piezoelectric actuator, and control of driving of the piezoelectric actuator by the drive circuit. In an endoscope apparatus having a control circuit and a switch means for supplying a control signal to the control circuit, the control circuit controls the drive circuit so as to change the speed of the piezoelectric actuator along with the operation time of the switch means. An endoscopic device characterized in that