JP2012213483A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an endoscope apparatus that can reduce the amount of energy consumed to drive a piezoelectric vibrator for generating surface acoustic wave on an inspection window.SOLUTION: The endoscope apparatus 1 includes: a transparent member 32 for an observation window; a piezoelectric vibrator 37 for generating ultrasonic vibration f; an operation circuit 61 for outputting an operation signal when the operation switch 13 is operated; a diffraction grating 40 for converting the ultrasonic vibration f generated by the piezoelectric vibrator 37 into a surface acoustic wave Φ propagated along an outer surface of the transparent member 32; a drive signal supply system 55 for supplying a drive signal to the piezoelectric vibrator 37; a power supply 51 for supplying power to the drive signal supply system 55; a switch circuit 53 for switching between a mode for outputting the drive signal to the piezoelectric vibrator 37 from the drive signal supply system 55 and a mode for stopping the output; and a control section 52 for controlling the switch circuit 53 to intermittently switch between the mode for outputting the drive signal to the piezoelectric vibrator 37 when an operational signal is being input from the operation circuit 61 and the mode for stopping the output.

Description

  The present invention relates to an endoscope apparatus in which dirt attached to the surface of an observation window is easily removed, thereby improving the observability and further reducing power consumption.

  In recent years, a surgical operation using an endoscope has been widespread for the purpose of minimally invasive medical treatment. In such an endoscopic operation, contamination of blood, fat, and the like is likely to occur, and it is a problem that the visual field is hindered by adhering to the observation window of the endoscope.

  As a countermeasure against this problem, for example, a technique of an endoscope apparatus disclosed in Patent Document 1 is known. This Patent Document 1 proposes a method of removing dirt adhering to an observation window of an endoscope apparatus by ultrasonic vibration or a surface acoustic wave obtained by converting it by a diffraction grating.

  In a conventional endoscope apparatus, a diffraction grating-shaped groove having a rectangular cross-sectional shape is formed as a deflecting portion on the outer surface of a glass plate serving as an observation window. ) To the adhesion surface (inner surface) of the piezoelectric vibrator of the glass plate, at least a part of the surface of the piezoelectric vibrator is located in the projection area of the groove.

  In this glass plate, the ultrasonic vibration generated by the piezoelectric vibrator is diffracted (deflected) by the grooves of the diffraction grating shape, and at least a part of the glass plate is in the above-described central direction, that is, the observation visual field region of the imaging unit 34. It becomes possible to efficiently propagate in the center direction of the portion facing the surface, and it is possible to efficiently remove dirt on the glass plate.

JP 2009-254571 A

  By the way, due to recent environmental circumstances, further reduction in power consumption is required not only for endoscope apparatuses but also for general electronic devices. However, in a conventional endoscope apparatus, in order to propagate a surface acoustic wave on a glass plate to which a piezoelectric vibrator is bonded in order to remove body fluid, electric power of several watts to several tens of watts is transmitted to the piezoelectric vibrator. It is necessary to supply a drive signal having a quantity. In such a circuit for supplying a drive signal to the piezoelectric vibrator, a relatively large bias current is required, so that the power consumption of the apparatus must be increased. Therefore, a conventional endoscope apparatus is required to reduce power consumption for driving a piezoelectric vibrator that generates surface acoustic waves on a glass plate.

  Accordingly, the present invention has been made in view of the above circumstances, and provides an endoscope apparatus capable of reducing power consumption for driving a piezoelectric vibrator that generates surface acoustic waves on an observation window. Objective.

  In order to achieve the above object, an endoscope apparatus according to an aspect of the present invention is provided with a transparent member provided at the distal end of an insertion portion so as to face an imaging optical system, and is provided on the transparent member to generate ultrasonic vibrations. A piezoelectric vibrator, an operation circuit for outputting an operation signal based on an operation of an operation switch for instructing operation of driving the piezoelectric vibrator, and the ultrasonic vibration generated in the piezoelectric vibrator provided in the transparent member. A diffraction grating for converting to a surface acoustic wave propagating to the outer surface of the transparent member, a drive signal supply system for supplying a drive signal for driving the piezoelectric vibrator, and a power supply for supplying power to the drive signal supply system; A switch circuit that is connected to the power source and switches between output and stop of a drive signal from the drive signal supply system to the piezoelectric vibrator, and the piezoelectric vibration while an operation signal is input by the operation switch And a control unit for controlling the switch circuit to intermittently switch the stop and outputs a drive signal to.

  ADVANTAGE OF THE INVENTION According to this invention, the endoscope apparatus which can reduce the power consumption which drives the piezoelectric vibrator which generates a surface acoustic wave on an observation window can be provided.

1 is an overall configuration diagram of an endoscope system according to a first embodiment of the present invention. The block diagram which mainly shows the internal configuration of the endoscope system Sectional drawing which shows the structure of the front-end | tip part of a rigid endoscope same as the above Fig. 3 is a sectional view taken along line IV-IV in Fig. 3 Sectional drawing which shows the structure of the front-end | tip part of a water supply sheath same as the above FIG. 5 is a plan view showing the configuration of the water supply sheath in the direction of arrow VI in FIG. The perspective view of the front-end | tip part which shows the state by which the insertion part of the rigid endoscope was insertedly arranged by the water supply sheath similarly The same fragmentary sectional view which shows the constitution of the tip part of the rigid endoscope Same as above, flowchart of main routine control executed by the control unit Same as above, flowchart of subroutine A control executed by the control unit Same as above, flowchart of subroutine B control executed by the control unit Front view and sectional view showing the distal end portion of the rigid endoscope Same as above, timing chart showing states of amplified power, signal power and drive signal based on operation signal

  Hereinafter, an endoscope apparatus according to the present invention will be described. In the following description, the drawings based on each embodiment are schematic, and the relationship between the thickness and width of each part, the thickness ratio of each part, and the like are different from the actual ones. It should be noted that the drawings may include portions having different dimensional relationships and ratios between the drawings.

  First, an embodiment of the present invention will be described based on the drawings. In the following description, for example, a rigid endoscope that performs laparoscopic surgery is illustrated. The present invention is applicable not only to rigid endoscopes but also to various endoscopes that are inserted into living body lumens.

  FIGS. 1 to 13 relate to the first embodiment of the present invention, FIG. 1 is an overall configuration diagram of the endoscope system, and FIG. 2 is a block diagram mainly showing the internal configuration of the endoscope system. 3 is a sectional view showing the configuration of the distal end portion of the rigid endoscope, FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a sectional view showing the configuration of the distal end portion of the water supply sheath, and FIG. FIG. 7 is a perspective view of the distal end portion showing a state in which the insertion portion of the rigid endoscope is inserted and disposed in the water supply sheath, and FIG. 8 is the distal end of the rigid endoscope. FIG. 9 is a flowchart of main routine control executed by the control unit, FIG. 10 is a flowchart of subroutine A control executed by the control unit, and FIG. 11 is a flowchart of subroutine B control executed by the control unit. FIG. 12 is a front view showing the distal end portion of the rigid endoscope And a sectional view, FIG. 13 is based on the operation signal, amplifies power, is a timing chart showing the states of signal power and drive signals.

  As shown in FIGS. 1 and 2, an endoscope system 1 that is an endoscope apparatus according to the present embodiment includes a rigid endoscope (hereinafter simply referred to as an endoscope) 2 and the endoscope 2. The insertion part 11 is mainly comprised by the water supply sheath 3 which comprises the washing | cleaning-liquid supply means by which it is inserted and arrange | positioned inside, the camera control unit (CCU) 5, the light source device 4, and the monitor (apparatus) 6. . The CCU 5, the light source device 4, and the monitor 6 constitute an extracorporeal device.

  The endoscope 2 includes an operation unit 12 connected to the hard insertion unit 11, switches 13 provided on the operation unit 12, a universal cable 14 that is a composite cable extending from the operation unit 12, The light source connector 15 disposed at the extending end of the universal cable 14, the electric cable 16 extending from the side of the light source connector 15, and the electric connector 17 disposed at the extending end of the electric cable 16 And is configured. The light source connector 15 is detachably connected to the light source device 4. The electrical connector 17 is detachably connected to the CCU 5.

  The CCU 5 is electrically connected to the light source device 4 and the monitor 6. The CCU 5 converts the image data captured by the endoscope 2 into a video signal and displays it on the monitor 6. Further, the CCU 5 receives operation signals from the switches 13 disposed in the operation unit 12 of the endoscope 2, and controls the light source device 4 based on these signals, or washing water such as physiological saline. Constitutes a control device which is a control means for sending air from the CCU 5 to the water supply tank 24 which is a water supply device in which water is stored and controlling the supply of the wash water in the water supply tank 24 to the water supply sheath 3. . The water supply tank 24 is connected to an air supply tube 25 provided with an air supply connector 26 detachably attached to the CCU 5 at its end.

Next, an internal configuration mainly of the endoscope system 1 will be described below based on FIG.
The CCU 5 receives a power source 51 for supplying power to each circuit and each unit, a control unit 52 having a processing circuit (CPU) for performing each process, and a control signal from the control unit 52, and receives the power source 51 and the circuit. A switch circuit 53 that switches connection to the memory, a memory 54 that stores a processing algorithm, a drive signal supply system 55 that is a power supply system that outputs a drive signal to the piezoelectric vibrator 37, and a distal end portion of the insertion portion 11. A timing generation circuit 56 that sends a clock signal, a control signal, and the like to the image pickup unit 34 disposed, and an image signal that is input from the image pickup unit 34, performs image processing, and outputs the image signal subjected to image processing to the monitor 6 And a processing circuit 57.

  The drive signal supply system 55 includes a signal generation circuit 58 that generates a reference signal, and an electric energy necessary for driving the signal from the signal generation circuit 58 and the piezoelectric vibrator 37 disposed at the distal end portion of the insertion portion 11. And an amplifier circuit 59 for amplifying the signal to a drive signal. The signal generation circuit 58 and the amplification circuit 59 of the drive signal supply system 55 are monitored by the detection circuit 60 for their states. The drive signal supply system 55 receives a control signal from the control unit 52 and controls the signal generation circuit 58 and the amplification circuit 59. The detection circuit 60 outputs the monitoring results of the signal generation circuit 58 and the amplification circuit 59 to the control unit 52 as detection signals.

  The operation unit 12 includes an operation circuit 61 that receives an input signal based on an operation of the switches 13 that gives instructions to generate / stop the surface acoustic wave Φ (see FIG. 8) together with water supply, and outputs the operation signal to the control unit 52. I have. The CCU 5 includes a pump control circuit (not shown) and a pump that is a compressor.

  The light source device 4 includes a light source such as a halogen lamp and a light source control circuit that drives the light source (all not shown). The light source control circuit is electrically connected to and controlled by the control unit 52 of the CCU 5.

Next, the configuration of the distal end portion of the insertion portion 11 of the endoscope 2 will be described below based on FIGS. 3 and 4.
As shown in FIGS. 3 and 4, the insertion portion 11 of the endoscope 2 is transparent at the tip of a metal tubular member 31 constituting the insertion portion exterior, which is an observation window here, which is a substantially disk-shaped glass plate. The member 32 is joined via an adhesive.

  Inside the tubular member 31, the above-described imaging unit 34 including an imaging optical system and two light guides 33 for illumination are arranged here. Although not shown in detail, the imaging unit 34 incorporates an imaging optical system, a solid-state imaging device, and a driver chip thereof, and a communication cable 35 is drawn out in the root direction.

  In addition, on the inner surface (back surface) of the transparent member 32, a region that does not obstruct the observation field of view, that is, one region side outside the imaging unit 34 that is oppositely arranged (in this case, a direction away from a part of the outer periphery by a predetermined distance). Further, for example, a rectangular piezoelectric vibrator 37 made of PZT is attached. A wiring 36 is connected to the piezoelectric vibrator 37 and is electrically driven. That is, in the piezoelectric vibrator 37, the wiring 36 that supplies a voltage for excitation is drawn out in the root direction of the endoscope 2. Further, the fixing of the piezoelectric vibrator 37 to the transparent member 32 is not limited to fixing with an adhesive, and solder or the like may be used. Further, the tubular member 31 and the transparent member 32 may be fixed with screws. The piezoelectric vibrator 37 is driven at or near the resonance frequency to generate ultrasonic vibration λ in the transparent member 32 (see FIG. 8).

  As shown in FIG. 3 (FIG. 8), the transparent member 32 diffracts the ultrasonic vibration λ at the position of the outer surface facing the piezoelectric vibrator 37 attached to the inner surface (back surface) to generate a surface acoustic wave. A diffraction grating 40 of a deflecting unit that converts (deflects) into Φ is provided. The diffraction grating 40 here is a plurality of irregularities having a rectangular cross section formed on the outer surface of the transparent member 32, here five groove portions 40a (see FIG. 8). These groove portions 40a are formed in parallel on the outer surface of the transparent member 32 at equal intervals, and are parallel concave grooves.

  The ultrasonic vibration generated from the piezoelectric vibrator 37 is propagated mainly in a direction perpendicular to the sticking surface of the piezoelectric vibrator 37 (the inner surface of the transparent member 32), and the transparent member 32 facing the piezoelectric vibrator 37. Is incident on the diffraction grating 40. The ultrasonic vibration λ incident on the diffraction grating 40 is converted (deflected) into a surface acoustic wave Φ propagating on the outer surface of the transparent member 32 by the diffraction grating 40 (see FIG. 8).

The components of the endoscope 2 are sealed by a tubular member 31 and a joined transparent member 32, and have a structure that can withstand sterilization with high-pressure steam.
Furthermore, in the present embodiment, the inner surface of the transparent member 32 that faces the imaging optical system of the imaging unit 34 is planar, but part of the surface that faces the imaging optical system has a convex lens shape or a concave lens shape. A part of the optical system may be configured.

  The light guide 33 according to the present embodiment extends to the universal cable 14, and the light guide 33 is terminated at the light source connector 15. The communication cable 35 and the wiring 36 are connected to the electrical connector 17 via the electrical cable 16.

  That is, in the endoscope 2, the light guide 33 is connected to the light source of the light source device 4 including the light source control circuit via the universal cable 14 and the electric cable 16, and the communication cable 35 drawn from the imaging unit 34 is used for image processing of the CCU 5. Wiring 36 drawn from the piezoelectric vibrator 37 is connected to the circuit 57 to a drive signal supply system 55 that constitutes the vibration means of the CCU 5.

Next, the water supply sheath 3 will be described below based on FIGS. 1, 5, and 6.
The water supply sheath 3 includes a coated tube 21 having a distal end member, a connection portion 22 provided continuously to the proximal end of the coated tube 21, and a water supply tube 23 extending from a side portion of the connection portion 22. Configured. The extended end of the water supply tube 23 is connected to the water supply tank 24. The water supply tank 24 is connected to the other end of an air supply tube 25 having one end connected to an air supply connector 26 of the CCU 5.

  The covered tube 21 of the water supply sheath 3 includes a tube main body 41 and a substantially cylindrical tip member 42 fitted to the tip of the tube main body 41. One part of the thick portion of the tube main body 41 is formed with one water supply passage 43 having a circular cross section for water supply. The water supply path 43 is disposed up to the connection portion 22 and communicates with the water supply tube 23 via the connection portion 22.

  The distal end member 42 has an eaves portion 44 that is a plate body along the opening end surface at a position facing the water supply path 43 of the tube main body 41.

  The water supply sheath 3 configured as described above is connected so that the water supply path 43 communicates with the water supply tank 24 via the water supply tube 23. Then, physiological saline or the like which is the washing water in the water supply tank 24 is fed into the water supply path 43 by increasing the pressure in the water supply tank 24 by the air from the pump controlled by the pump control circuit. It flows to the tip of the endoscope.

  In the endoscope system 1 of the present embodiment described above, as shown in FIG. 7, the insertion portion 11 of the endoscope 2 is inserted and disposed in the covering tube 21 of the water supply sheath 3, for example, laparoscopic surgery Used for surgery.

Here, when the endoscope system 1 is used, an example of drive control of the piezoelectric vibrator 37 is executed according to the routine (step S) in the flowcharts of FIGS. 9 to 11, and FIGS. 8, 12, and 13. An example of the control will be described below.
First, in step S1, the control unit 52 determines the state of the operation signal from the operation circuit 61, that is, whether there is a signal input. When the user performs an ON operation intended to generate a surface acoustic wave using the switches 13, the voltage level of the operation signal from the operation circuit 61 becomes high, and the processing in steps S 2 and S 3 (subroutine A) , B) is executed.

  In addition, when the voltage level of the operation signal from the operation circuit 61 in which the switches 13 are in a non-operation (OFF operation) signal non-input state and the voltage level of the operation signal from the operation circuit 61 is low (Low), the control unit 52 performs steps S2 and S3. Does not shift to loop control or exits from this loop processing.

  In step S2, the control unit 52 executes the control of the subroutine A shown in FIG. In this subroutine A, the control unit 52 supplies power to the amplifier circuit 59 in step S11. At this time, the switch circuit 53 switches to a path for supplying power from the power source 51 to the amplifier circuit 59 by a control signal from the processing circuit of the control unit 52.

Next, in step S12, the control unit 52 resets the internal counter i.
In step S <b> 13, the control unit 52 supplies power to the signal generation circuit 58. At this time, the switch circuit 53 switches to a path for supplying power from the power supply 51 to the signal generation circuit 58 by a control signal from the processing circuit of the control unit 52. As a result, the signal generated in the signal generation circuit 58 is input to the amplification circuit 59, amplified to a drive signal having an electric energy necessary for driving the piezoelectric vibrator 37, and then output to the piezoelectric vibrator 37.

  By executing the routine from step S11 to step S13, the control unit 52 first supplies power to the amplifier circuit 59 to make it high by switching control of the switch circuit 53, and then a predetermined time Δt has elapsed. Later, power is supplied to the signal generation circuit 58 to make it high (see FIG. 13). As a result, the amplification circuit 59 is driven before the signal generation circuit 58 that generates the reference signal is driven, the drive is amplified based on the generated reference signal, and has an electric energy necessary for driving the piezoelectric vibrator 37. A signal is output and the piezoelectric vibrator 37 is driven. Further, the signal generation circuit 58 can change the signal value of the reference signal to be generated by a control signal from the processing circuit of the control unit 52.

  Next, in step S14, the control unit 52 counts up the internal counter i. In step S15, the control unit 52 determines the counter i and exits the loop processing (repetition processing) from step S13 to step S14. Whether to determine whether or not. In step S15, the control unit 52 determines whether the counter i has reached a threshold value X described later.

  Further, the memory 54 stores a value T (obtained by dividing the distance d from the end P of the diffraction grating 40 to the end Q of the transparent member 32 (see FIG. 12) by the velocity v of the surface acoustic wave Φ. The threshold value X for supplying the drive signal to the piezoelectric vibrator 37 for the amount of time TH (<2T: see FIG. 13) whose upper limit is a value obtained by doubling (= d / v) is stored.

  When the amount of time TH corresponding to the threshold value X has elapsed (counter i ≧ threshold value X), the control unit 52 controls the switch circuit 53 to stop the power supply to the signal generation circuit 58 in step S16. At this time, the switch circuit 53 switches to a path that does not supply power from the power supply 51 to the signal generation circuit 58 by a control signal from the processing circuit of the control unit 52.

  When the above subroutine A is performed, the process proceeds to the main routine of FIG. 9, and step S3 is executed. In step S3, subroutine B shown in FIG. 11 is executed.

  In this subroutine B, the control unit 52 resets the internal counter j in step S21. Next, in step S <b> 22, the control unit 52 stops power supply to the amplifier circuit 59. At this time, the switch circuit 53 switches to a path that does not supply power from the power source 51 to the amplifier circuit 59 by a control signal from the processing circuit of the control unit 52.

In the routine of step S16 and step S22, the control unit 52 first stops the power supply to the signal generation circuit 58 and switches it to low (Low) by switching control of the switch circuit 53, and then a predetermined time Δt has elapsed. Later, the power supply to the amplifier circuit 59 is stopped and set to low (see FIG. 13). As a result, while the signal generation circuit 58 for generating the reference signal is driven, the amplifier circuit 59 is always driven, and the drive signal having the necessary electric power amplified based on the generated reference signal is supplied to the piezoelectric vibrator. 37 can be output.

  In step S23, the control unit 52 counts up the internal counter j, and in step S24, determines whether or not the counter j has reached a predetermined value (set threshold value Y) and from step S22. A determination process is performed as to whether or not the process exits the loop process (repetition process) of step S23.

That is, the supply of the drive signal to the piezoelectric vibrator 37 is stopped for a time amount TL (see FIG. 13) corresponding to the threshold value Y set in the memory 54. Note that the threshold Y may be set and stored in the memory 54 in consideration of the physical properties of the piezoelectric vibrator 37 to be used. The amount of time corresponding to the threshold value Y is obtained by dividing the distance d from the end P of the diffraction grating 40 to the end Q of the transparent member 32 (see FIG. 12) by the velocity v of the surface acoustic wave Φ. A time amount TL (> 2T: see FIG. 13) having a value lower than a value obtained by doubling the value T (= d / v).

When the amount of time TL is twice or more than the amount of time T , the surface acoustic wave Φ that is deflected by the diffraction grating 40 and propagates to the transparent member 32 and reaches the tubular member 31 is reflected and reversely directed. Even if the surface acoustic wave Φ is generated, the piezoelectric vibrator 37 is driven again after all the surface acoustic waves Φ in the opposite direction reach the diffraction grating 40. Accordingly, it is possible to prevent the surface acoustic wave Φ that has been deflected and travels to the newly generated diffraction grating 40 by the surface acoustic wave Φ in the reverse direction reflected by the tubular member 31 from being attenuated.

  When the above subroutine B is executed, the routine proceeds to the main routine of FIG. 9, and step S4 is executed. In step S <b> 4, the control unit 52 grasps the power supply state from the power supply 51 to the signal generation circuit 58 by the switch circuit 53 from the detection signal of the detection circuit 60. At this time, if the power supply voltage level of the signal generation circuit 58 is high (High), the control unit 52 proceeds to step S5 and switches the switch circuit 33 to control the power supply from the power supply 51 to the signal generation circuit 58. Stop supplying. In other words, the switch circuit 53 switches to a path that does not supply power from the power source 51 to the signal generation circuit 58 by a control signal from the processing circuit of the control unit 52.

  On the other hand, in the determination of step S4, the control unit 52 proceeds to step S6 when the power supply voltage level of the signal generation circuit 58 is low. In step S <b> 6, the control unit 52 grasps the state of power supply from the power supply 51 to the amplifier circuit 59 by the switch circuit 53 from the detection signal of the detection circuit 60.

  At this time, if the power supply voltage level of the amplifier circuit 59 is high (High), the control unit 52 proceeds to step S7 and switches the switch circuit 53 to control the power supply from the power supply 51 to the amplifier circuit 59. stop. That is, the switch circuit 53 switches to a path that does not supply power from the power source 51 to the amplifier circuit 59 by a control signal from the processing circuit of the control unit 52.

  On the other hand, in the determination in step S6, the control unit 52 ends the main routine when the power supply voltage level of the amplifier circuit 59 is low. Moreover, also after passing through the process of step S7, the control part 52 complete | finishes a main routine. However, the main routine shown in FIG. 9 is repeatedly run in a normal use state of the endoscope system 1.

  As described above, when the endoscope system 1 of the present embodiment is in use, if the main routine shown in FIG. 9 is run, the drive signal to the piezoelectric vibrator 37 is triggered by the operation signal from the operation circuit 61. In addition, the power supply to the drive signal supply system 55 can be intermittently performed.

  That is, as shown in the timing chart of FIG. 13, the switch circuit 53 by the control unit 52 under the condition that the voltage level of the operation signal from the operation circuit 61 is high by the ON operation of the operation switches 13 by the user. With the switching control, the drive signal is supplied from the power source 51 to the piezoelectric vibrator 37 for the time amount TH corresponding to the set threshold value X, and the threshold value is set as the time amount when the drive signal is not supplied to the piezoelectric vibrator 37. In the time amount TL corresponding to Y, power supply from the power supply 51 to the drive signal supply system 55 is stopped. That is, under the condition that the voltage level of the operation signal from the operation circuit 61 is high, a drive signal as shown in FIG. 13 is supplied to the piezoelectric vibrator 37.

  It should be noted that even when the voltage level of the operation signal from the operation circuit 61 is low when the user does not operate the operation switches 13 (OFF), the switching of the switch circuit 53 by the control unit 52 is controlled. The power supply from the power supply 51 to the drive signal supply system 55 is stopped.

  As described above, the endoscope system 1 according to the present embodiment does not clean the transparent member 32 that is the observation window by the surface acoustic wave Φ (the piezoelectric vibrator 37 is not driven). By switching the power supply from the power supply 51 to the drive signal supply system 55, the power consumption due to the bias current in the signal generation circuit 58 and the amplification circuit 59 constituting the drive signal supply system 55 is reduced. be able to.

  In addition, when the voltage level of the operation signal from the operation circuit 61 is switched to high by the user's ON operation of the operation switches 13, the control unit 52 first controls the amplification circuit 59 by switching control of the switch circuit 53. After a predetermined time Δt elapses, the signal generation circuit 58 is set to high.

  Then, when the amount of time TH corresponding to the threshold value X has elapsed, the control unit 52 first sets the signal generation circuit 58 to Low by switching control of the switch circuit 53, and then amplifies the circuit 59 after a predetermined time Δt has elapsed. Is set to Low.

  By such control, first, the signal generation circuit 58 is activated after the amplification circuit 59 is activated. Therefore, the reference signal generated by the signal generation circuit 58 is necessary for driving the piezoelectric vibrator 37 by the amplification circuit 59. Amplification of the amount of electric power to the drive signal can be performed stably.

  The invention described in the above embodiment is not limited to the embodiment and modifications, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements.

  For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the described requirements can be deleted if the stated problem can be solved and the stated effect can be obtained. The configuration can be extracted as an invention.

DESCRIPTION OF SYMBOLS 1 ... Endoscope system 1 ... Endoscope apparatus 2 ... Endoscope 3 ... Water supply sheath 4 ... Light source device 5 ... Camera control unit (CCU)
6 ... Monitor 11 ... Insertion part 12 ... Operation part 13 ... Switches 13 ... Operation switches 14 ... Universal cable 15 ... Light source connector 16 ... Electric cable 17 ... Electric connector 21 ... Cover tube 22 ... Connection part 23 ... Water supply tube 24 ... Water supply tank 25 ... Air supply tube 26 ... Air supply connector 31 ... Tubular member 32 ... Glass plate 33 ... Light guide 34 ... Imaging unit 35 ... Communication cable 36 ... Wiring 37 ... Piezoelectric vibrator 40 ... Diffraction grating 40a ... Groove 41 ... Tube Main body 42 ... tip member 43 ... water supply path 44 ... eaves part 51 ... power supply 52 ... control part 53 ... switch circuit 54 ... memory 55 ... drive signal supply system 56 ... timing generation circuit 57 ... image processing circuit 58 ... signal generation circuit 59 ... Amplifier circuit 60 ... detection circuit 61 ... operation circuit d ... distance f ... ultrasonic vibration i, j ... counter TH, TL ... During periods of v ... speed X, Y ... threshold Delta] t ... time lambda ... ultrasonic vibrations [Phi ... SAW

Claims (6)

A transparent member provided at the distal end of the insertion portion so as to face the imaging optical system;
A piezoelectric vibrator that is provided on the transparent member and generates ultrasonic vibration;
An operation circuit that outputs an operation signal based on an operation of an operation switch that instructs to drive the piezoelectric vibrator;
A diffraction grating provided on the transparent member and converting the ultrasonic vibration generated by the piezoelectric vibrator into a surface acoustic wave propagating to the outer surface of the transparent member;
A drive signal supply system for supplying a drive signal for driving the piezoelectric vibrator;
A power supply for supplying power to the drive signal supply system;
A switch circuit that is connected to the power source and switches output and stop of the drive signal from the drive signal supply system to the piezoelectric vibrator;
A control unit that controls the switch circuit so as to intermittently switch the output and stop of the drive signal by the drive signal supply system to the piezoelectric vibrator while the operation signal from the operation circuit is being input;
An endoscope apparatus comprising:   The control unit causes the switch circuit to supply power from the power source to the drive signal supply system so that the drive signal is stopped for a stop time longer than an output time for outputting the drive signal to the piezoelectric vibrator. The endoscope apparatus according to claim 1, wherein the endoscope apparatus is switched intermittently.   The stop time has a lower limit of twice the time obtained by dividing the distance from the end of the diffraction grating to the end of the transparent member by the speed of the surface acoustic wave traveling to the transparent member. The endoscope apparatus according to claim 2, wherein A signal generation circuit that generates a reference signal that the drive signal supply system outputs to the piezoelectric element; and an amplification circuit that amplifies the reference signal to a predetermined level.
The said control part starts the said signal generation circuit after starting the said amplifier circuit first at the time of the output start of the drive signal to the said piezoelectric element, The any one of Claims 1-3 characterized by the above-mentioned. The endoscope apparatus according to item.   5. The endoscope apparatus according to claim 4, wherein when the drive signal to the piezoelectric element is stopped, the control unit stops the amplification circuit after stopping the signal generation circuit first. 6.   The control unit is a value that is twice the time obtained by dividing the distance from the end of the diffraction grating to the end of the transparent member by the speed of the surface acoustic wave traveling to the transparent member. 6. The switch circuit according to claim 1, wherein the switch circuit is subjected to switching control so that a drive signal from the drive signal supply system is output to the piezoelectric vibrator for an amount of time having an upper limit of λ. The endoscope apparatus described in 1.

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