JP5359113B2 - Operation detection method, operation detection apparatus, and frequency adjustment apparatus for shutter mechanism - Google Patents

Description

  The present invention relates to an operation detection method, an operation detection device, and a frequency adjustment device for a shutter mechanism that drives a shutter to two open / close positions by a solenoid.

  Conventionally, a method of adjusting the frequency of a piezoelectric element by etching the piezoelectric element with an ion beam is known. At that time, a shutter for adjusting the ion beam irradiation time to the piezoelectric element is provided, and a solenoid is used as an actuator for driving the shutter.

  Patent Document 1 discloses an apparatus for adjusting the frequency of a piezoelectric element by ion beam etching in a vacuum chamber, and selectively selects a piezoelectric substrate having a plurality of electrodes formed on the surface and a plurality of electrodes on the piezoelectric substrate. Corresponding to the number of electrodes exposed from the opening of the base plate, an ion source that simultaneously irradiates an ion beam to a plurality of electrodes exposed from the opening of the base plate, The frequency adjustment device having the same number of shutter mechanisms that can be independently driven is disclosed.

  1 and 2 of Patent Document 1 disclose an example in which all shutter mechanisms including a shutter and a solenoid are arranged inside a vacuum chamber. Ion beam irradiation time is adjusted and the frequency is adjusted by opening and closing the shutter with a solenoid, but there is no function to detect whether the shutter operation has been performed correctly, so there is some problem with the shutter. However, when a malfunction occurs in the operation, there is a possibility that discovery will be delayed, resulting in repeated adjustment failures. There is a method of separately providing a sensor for detecting the movement of the shutter. However, when the shutter mechanism is disposed in the vacuum chamber, the sensor must also be disposed in the vacuum chamber, which makes it difficult to install the sensor. Further, as the number of shutters (solenoids) increases, the number of sensors increases, and the apparatus becomes larger accordingly.

  In Patent Document 2, in a printer device for printing data on a recording paper, a recording paper conveyed from a paper feeding unit is cut by a cutter unit, and a discharging unit that discharges the recording paper cut by the cutter unit is provided. Some have a shutter driven by a solenoid. The solenoid is driven to operate the shutter, and the control unit controls the open state of the shutter by chopping control, provides a position detection unit in the shutter unit, and performs opening / closing control of the shutter unit by an output signal from the position detection unit. Yes.

  In the case of Patent Document 2, the control unit performs two-step control on the shutter driving solenoid, that is, solenoid suction control and holding control. In the suction control, a DC voltage is applied for a predetermined time, and in the holding control, a pulse train voltage is applied. Since the current flowing through the solenoid during the holding control changes depending on the position of the movable iron core in the solenoid, the position of the movable iron core in the solenoid can be detected by detecting the difference in change in the current value. Therefore, the open / close state of the shutter can be detected, and the position of the shutter can be detected by the solenoid drive unit without providing any special position detecting means for detecting the open / close state of the shutter.

The current that flows through the solenoid during holding control changes depending on the position of the movable core in the solenoid. The coil inductance changes depending on the position of the movable core in the solenoid, and the pulse current that flows there is close to an alternating current. Therefore, it is shown that the current changes due to the influence of the inductance. The position of the shutter is detected from this change. However, this change in current is not only due to the inductance, but also a change in current due to the coil being heated and the resistance value changing. For this reason, in the case where the coil is heated continuously using a solenoid, or in an environment where the temperature change is large, it is impossible to distinguish whether the current change is due to position or temperature. Furthermore, since the position of the movable iron core can be detected only when the pulse current is switched during the holding control, the time when the operation is completed cannot be known. Therefore, it cannot be determined whether or not the movable iron core has moved in a desired operation time.
JP 2004-56455 A Japanese Utility Model Publication No. 7-19265

  SUMMARY OF THE INVENTION An object of the present invention is to provide a shutter mechanism operation detection method and apparatus capable of detecting the opening / closing operation of a shutter from a change in driving current passed through a shutter driving solenoid.

In order to achieve the above object, according to the first embodiment of the present invention, a movable iron core is linearly moved by flowing a drive current through a shutter that can be operated in two positions of an open position and a closed position. And a solenoid for driving to open and close the shutter, and a step of continuously measuring a drive current flowing through the coil when the solenoid is driven, and a size of a depression of the waveform of the drive current. A step of determining, wherein the depression of the waveform is caused by a decrease in the driving current due to a back electromotive force corresponding to a driving speed of the movable iron core after the driving current has increased from an initial value to a steady value. core said drive current to reach the stroke end is generated by rises to a steady value, the steps, the shutter depending on the size of the recess of the waveform And detecting the opening and closing operation, provides an operating method of detecting a shutter mechanism having a.

In the second embodiment of the present invention, the shutter is operable in two positions, an open position and a closed position, and the movable iron core is moved by passing a driving current through the coil, and the shutter is connected to the movable iron core. A means for continuously measuring a drive current flowing through the coil when the solenoid is driven, and a means for determining the size of the depression of the waveform of the drive current. In the depression of the waveform, after the drive current rises from an initial value to a steady value, the drive current decreases due to a back electromotive force according to the drive speed of the movable core, and then the movable core reaches a stroke end. hand detecting the opening and closing operation of the shutter the drive current is generated by rises to a steady value, and means, depending on the size of the recess of the waveform by If, to provide a motion detection apparatus of the shutter mechanism having a.

  In the present invention, the change in the drive current when the solenoid coil is energized is continuously measured. When the coil is energized, the drive current increases rapidly from the initial value (= 0). When the movable iron core (shutter) starts driving, a back electromotive force is generated according to the driving speed of the movable iron core, so that the driving current starts to decrease. As the driving speed of the movable iron core increases with time, the drive current also decreases. Eventually, when the movable iron core reaches the stroke end and the movement of the movable iron core stops, the back electromotive force is not generated. Therefore, the dent of the current waveform at the time of reaching the stroke end becomes the lowest value, and then rises to the steady value. In this way, in the normal state, a “waveform dent” appears in which the drive current temporarily decreases with the movement of the movable iron core. If the solenoid does not move for some reason, this dent will not occur, so the presence or absence of the dent is detected. Thus, it is possible to detect whether the opening / closing operation of the shutter is normal. By measuring the current change of the coil in this way, an operation error of the shutter can be detected. Therefore, the position detection sensor can be omitted, and the present invention can be used even when the shutter mechanism is disposed in a vacuum. In addition, since it is not necessary to observe a change in inductance using a pulse current, detection is possible even in a situation where the temperature change is large and the resistance value of the coil changes.

  As a specific method for determining the presence or absence of a waveform depression, the determination may be made by the ratio between the current value at the lowest point of the depression and the current value at a steady value. If the shutter operates normally, the lowest point will be the bottom of the indentation, and the highest point will be a steady value, so there will be a difference between the two, but if it does not operate, there will be no indentation. This is because there is no difference. For example, calculate the ratio between the lowest value and the highest value (steady value) of the measured indentation, and compare with a predetermined threshold value. If the calculated value is less than the threshold value, determine that it is normal. Can do.

  As another method for determining the presence / absence of a dent in the waveform, it can be determined by the area of the dent. The area of the dent can be easily obtained by integrating with a steady value of zero. When there is no dent, this area is almost zero, but when there is a dent, the area is larger than the threshold value, so that the operation can be detected. In comparison between the lowest and highest points, it is difficult to distinguish when the shutter operation is slow and a shallow and long depression with a gentle slope occurs, but the area is a large value if it is shallow but long. Therefore, the presence or absence of a dent can be easily determined. Even if there is a lot of noise, if the noise is integrated, it becomes approximately zero, so that the determination is easy.

  As yet another method for determining the presence / absence of a dent in the waveform, a reference value is set between the lowest expected value and the steady value of the dent, and after the drive current rises from the initial value to the reference value or more, the reference It is also possible to determine the shutter operation based on whether or not the reference value is exceeded again when the value drops below the value. This method is effective when the driving speed of the shutter is fast, the shutter starts to be driven before the current once rises from the voltage application start to the steady value, and the current rise and the depression overlap. In the above-described method, it is necessary to predict in advance a region where a depression can be made, and if a current rising portion enters the region, the minimum value becomes small even if there is no depression, and the operation may not be determined correctly. However, this method facilitates the determination because it observes whether there is a decrease in current due to the back electromotive force after the current rise at the start of application.

  The operating time of the movable iron core (shutter) can also be detected from the elapsed time from the start of driving the solenoid to the lowest point of the indentation, as well as detecting whether the shutter opening / closing operation is normal from the presence or absence of the indentation. That is, the shutter operation speed can be known. For this reason, not only the presence or absence of a dent but also a case where the drive time is slow can be detected as an operation failure, and an operation abnormality can be known before the shutter completely stops moving.

  If the drive current is too large, the movable iron core may bounce back in the opposite direction at the stroke end. In this case, an electromotive force is generated in the direction in which the drive current increases, and thus shows a change that once exceeds the steady value and then returns to the steady value. Therefore, it can be determined whether or not the drive current is too large, and it becomes easy to adjust the drive current to an optimum value.

  The solenoid in the present invention may be a solenoid provided with one coil, or has two coils arranged at intervals in the axial direction, and reciprocates the movable iron core by flowing current alternately through these coils. A solenoid to be driven may be used. In the case of a solenoid having a single coil, it is possible to determine the operation in one direction of the movable iron core from the change in the drive current when the coil is energized. Cannot be determined. Also, the stroke is small. On the other hand, in the case of a solenoid using two coils, the movable iron core can be operated in two positions by alternately passing current through the two coils. The movement of the movable iron core in both directions, that is, the movement of both the opening operation and the closing operation of the shutter can be detected. And since it moves to both opening and closing positions with the neutral position in between, there is an advantage that the stroke becomes large.

  According to the present invention, since the opening / closing operation of the shutter is detected based on the presence or absence of the depression of the waveform of the driving current flowing in the coil, a plurality of shutter operations can be confirmed simultaneously without using a special sensor, and further, no sensor is used. It can also be used in a special environment. Further, since the driving current is continuously observed, the time when the shutter operation is completed can be known from the bottom time of the current depression. By managing this driving time, it is possible to know the maintenance time of the solenoid. Since the change in current from the start of driving is measured / analyzed rather than the inductance at the driving end position, it is possible to cope with the case where the driving current itself changes due to heating of the coil or the like. By monitoring the shutter operation in this manner, it is possible to prevent a reduction in the yield rate due to a defective shutter operation and to determine whether or not the shutter needs to be maintained.

  Hereinafter, preferred embodiments of the present invention will be described based on examples.

  1 and 2 show an example of a frequency adjusting device to which a shutter mechanism according to the present invention is applied. The frequency adjusting device 1 includes a processing chamber 2 having a hermetically sealed structure, and a vacuum pump 4 is connected to the side of the processing chamber 2 via an opening / closing door 3. By driving the vacuum pump 4, the inside of the processing chamber 2 is kept at a predetermined degree of vacuum. An etching ion gun 5 is installed on the ceiling of the processing chamber 2. As shown in FIG. 1, the ion gun 5 can irradiate an ion beam IB having a substantially constant intensity per unit area downward within a predetermined range.

  A movable stage (conveying means) 6 is provided at the bottom of the processing chamber 2, and a wafer 10 is positioned and held thereon. The wafer 10 is made of, for example, a piezoelectric substrate, and an area 10a having a plurality of elements as one unit is densely arranged in a matrix at a constant pitch P, as shown in FIG. Note that one area 10a is not limited to including a plurality of elements, and may be composed of one element. The movable stage 6 can carry the wafer 10 intermittently in the direction of arrow A at intervals of the pitch P of the area 10a. The frequency of each area 10a of the wafer 10 at the previous stage sent to the frequency adjusting apparatus is set in a state shifted in advance in the direction opposite to the frequency change direction by the ion beam irradiation, and the target value is obtained by the ion beam irradiation. It is adjusted in the direction approaching. Any material that can adjust the frequency, such as an electrode or a protective film formed on the wafer 10, may be etched by ion beam irradiation. The frequency of each area 10a of the wafer 10 is measured in advance, and the amount of frequency deviation with respect to the target value is obtained individually.

  Above the movable stage 6, a shutter base 11 is installed at a fixed position and horizontally. At the center of the shutter base 11, an opening 11a having a size substantially corresponding to the ion beam irradiation range by the ion gun 5 is formed. A pattern mask 15 that blocks an ion beam other than the target area is positioned and fixed in the opening 11 a of the shutter base 11. The pattern mask 15 is preferably supported as close to the wafer 10 as possible. A plurality of mask holes 15 a are formed in the pattern mask 15 independently for each area 10 a of the wafer 10. The size of each mask hole 15a is determined according to the distance between the pattern mask 15 and the wafer 10 and the diffusion angle of the ion beam, but is set substantially equal to the size of each area 10a. The mask holes 15a in this example are provided in two rows in the direction orthogonal to the wafer transfer direction and alternately shifted in the wafer transfer direction (A direction) so that the process for one row of the wafer 10 is performed in two stages. ing. That is, the odd-numbered and even-numbered mask holes are provided shifted in the A direction (transport direction). The mask holes on the downstream side (left side) in the transport direction correspond to the odd-numbered areas, and the mask holes on the upstream side (right side) in the transport direction correspond to the even-numbered areas. An interval d that is the same as one row (= P) of the area 10a is provided between the left mask hole 15a and the right mask hole 15a. The space d in the A direction between the left and right mask holes 15a is not limited to one row, but may be one element or a plurality of elements, and can be arbitrarily selected according to the area allocation.

  A shutter mechanism 20 is provided on the shutter base 11. The shutter mechanism 20 includes a plurality of solenoids 12 fixed on the shutter base 11 on both sides of the opening 11a. Each solenoid 12 is connected to a shutter 14 via a shaft 13, and each shutter 14 is individually operated in the horizontal direction by the respective solenoid 12. The solenoid 12 is preferably provided with a main body provided with a coil, a yoke, and the like, and a shaft 13 that operates integrally with the movable iron core, and is capable of operating the shaft 13 at two positions of opening and closing by energizing the coil. For example, it is preferable to be able to operate between several tens of milliseconds or less between the open position and the closed position. Each shutter 14 is provided corresponding to each mask hole so that each mask hole 15a can be opened and closed individually. That is, the left shutter 14 is operated in the opposite direction so as to open and close the left mask hole 15a and the right shutter 14 is opened and closed. The width and length of the shutter 14 are larger than the vertical and horizontal dimensions of the mask hole so that the mask hole 15a can be completely covered. The movements of the movable stage 6 and the solenoids 12 are controlled by the control device 16 so as to adjust the frequency of the area in one row in the direction orthogonal to the wafer transfer direction in a plurality of stages. The control device 16 stores a frequency shift amount with respect to a target frequency in each area of the wafer 10 in association with an ion beam irradiation time.

  After the wafer 10 is transferred below the pattern mask 15, all shutters are opened, and all areas are irradiated with ion beams through the mask holes 15a. Then, the shutter is sequentially closed from the shutter corresponding to the area where the desired irradiation time (irradiation time corresponding to the frequency shift amount) has elapsed, and after all the shutters are closed, the wafer 10 is transferred by one pitch in the transfer direction. The

  FIG. 3 shows an example of a specific structure of the solenoid 12. This solenoid 12 is commercially available as a three-position solenoid. As shown in FIG. 3, two coils 121 and 122 are disposed in the frame 120 made of a magnetic material with an interval in the axial direction. A fixed magnetic pole 123 is provided between the coils 121 and 122. A movable iron core 124 is disposed in the center of the coils 121 and 122 so as to be movable in the axial direction, and the shaft 13 is inserted into and fixed to the axis of the movable iron core 124. Fixed magnetic poles 125 and 126 are disposed at both ends of the frame 120 and at the inner peripheral portions of the coils 121 and 122, respectively. The shaft 13 is slidably inserted into the fixed magnetic poles 125 and 126. A spring (not shown) is accommodated in the left fixed magnetic pole 125.

  3A is a neutral position, FIG. 3B is a shutter closed position, and FIG. 3C is a shutter open position. When the coils 121 and 122 are not energized, the movable iron core 124 is held at a position where it does not contact any of the fixed magnetic poles 125 and 126, that is, a neutral position, by the repulsive force of the spring. When the right coil 122 is energized, a magnetic circuit as shown by a broken line is formed by the frame 120 surrounding the right coil 122, the fixed magnetic pole 123, the movable iron core 124, and the fixed magnetic pole 126, so that the movable iron core 124 is fixed on the right side. It is attracted to the magnetic pole 126 (see FIG. 3B). Since the movable iron core 124 and the shaft 13 move integrally to the right, the spring is compressed. 3B, when the left coil 121 is energized and the right coil 122 is de-energized, the movable iron core 124 and the shaft 13 are first returned to the neutral position by the repulsive force of the spring, and then the left side. Since the magnetic circuit as shown by the broken line is formed by the frame 120, the fixed magnetic pole 123, the movable iron core 124, and the fixed magnetic pole 125 surrounding the coil 121, the movable iron core 124 is attracted to the left fixed magnetic pole 125 (FIG. 3). (See (c)). Since the movable iron core 124 and the shaft 13 move integrally to the left, the spring is pushed by the shaft 13 and compressed.

  Thus, by alternately energizing the coils 121 and 122, the movable iron core 124 can reciprocate between the fixed magnetic poles 125 and 126 on both sides across the neutral position, compared to a solenoid having a single coil. About twice the stroke S can be obtained. Further, as will be described later, since the movement in both opening and closing directions can be detected from the change in the drive current flowing in the coils 121 and 122, it can be determined from the current change whether the shutter 14 is in the open position or the closed position. .

  FIG. 4 shows an example of a drive detection circuit for the solenoid 12. The two coils 121 and 122 are connected to the solenoid drive circuit 133 via wirings 131 and 132, and resistors 134 and 135 for converting the drive current flowing in the coils 121 and 122 into voltages are provided in the middle of the wirings 131 and 132, respectively. Is provided. The resistors 134 and 135 are connected to a microcomputer (hereinafter referred to as a microcomputer) 137 via a noise filter 136. The microcomputer 137 is provided with an A / D converter 138, a CPU 139, and an I / O unit 140. The I / O unit 140 is connected to a PLC (programmable controller) 141, and an operation command signal is output from the PLC 141 to the solenoid drive circuit 133, and at the same time, a measurement start signal is output to the microcomputer 137. The microcomputer 137 receives / measures the measurement start signal from the PLC 141 and continuously measures / records the drive current flowing in the coils 121 and 122 (for example, at an interval of 0.1 msec), and determines the presence / absence of a waveform indentation, which will be described later. The result (signal of good operation G or bad NG) is output to the PLC 141.

Next, a flow for determining whether or not the solenoid 12 is driven will be described with reference to FIG.
(1) When the PLC 141 outputs an operation command signal for opening and closing the shutter, the relay of the solenoid drive circuit 133 is turned on, and the solenoid 12 is energized to start operation. At the same time, the PLC 141 outputs a current measurement start signal to the microcomputer 137, and the microcomputer 137 starts measurement. Thereafter, the microcomputer 137 records the drive current value every 0.1 msec.
(2) When the solenoid 12 is energized, the current increases rapidly as shown in FIGS. 5 (a) and 5 (b).
(3) When the movable iron core 124 starts to operate, a back electromotive force is generated according to the moving speed of the movable iron core 124, so that the drive current starts to decrease.
(4) Since the moving speed of the movable iron core 124 increases with time, the drive current also decreases. This appears as a depression H of the drive current shown in FIG. When the movable iron core 124 does not move for some reason, the dent H is not generated as shown in FIG. 5B, and the operation of the shutter can be detected by detecting the presence or absence of the dent H.
(5) When the movable iron core 124 reaches the stroke end and stops its operation, no back electromotive force is generated. Therefore, when the movable core 124 reaches the stroke end, the current reaches the minimum value, and then reaches a steady value. The shutter driving time T can be known from this minimum time, and even when the driving time is long, it can be detected as an operation failure. Depending on the structure, the operation of the solenoid is completed in 15 to 25 msec. When the movable iron core 124 rebounds in the reverse direction at the stroke end, an electromotive force is generated in the direction in which the drive current increases after the dent H, and once the steady value is exceeded as shown in FIG. Return to value.
(6) After the current recording is completed, the microcomputer 137 analyzes the obtained waveform, and compares the lowest point and the highest point in the range where the depression of the predetermined waveform is predicted to occur. When the shutter operates, the lowest point is the bottom of the indentation, and the highest point is a steady value, so there is a difference between the two, but if it does not operate, the indentation does not occur, so the minimum and maximum values are comparable. Value (steady value: I = V / R), which can be easily discriminated.
(7) The ratio between the minimum value and the maximum value is calculated, and if this is smaller than the threshold value, it is determined that the shutter has operated normally. As shown in FIG. 5A, assuming that the current value at the lowest point is Id and the current value at the highest point is Is, it is determined that the current is normal when Id / Is is smaller than the threshold value. Since the time required for the analysis is about 5 msec when there is one shutter, even a shutter mechanism provided with a large number of shutters can be analyzed in a short time.

  As described above, the ratio between the minimum value and the maximum value is calculated and compared with the threshold value, and the indentation area S (shown by hatching in FIG. 6) is obtained by integrating the steady value as zero. The determination may be made by comparing the area S with a threshold value. When there is no depression, the area S is almost zero, but when there is a depression, the area S is larger than a certain value, so that the shutter operation can be detected. It is also possible to determine whether the shutter operation is good or bad by combining a method of comparing the ratio of the minimum value to the maximum value with a threshold value and a method of comparing the area S of the depression with the threshold value.

  Further, as shown in FIG. 7, after setting the reference value Ir to an intermediate level between the lowest value (expected value) and the highest value (steady value), the drive current increases from the initial value to the reference value Ir or more, The shutter operation can also be determined based on whether or not the reference value Ir has once exceeded the reference value Ir. Note that the minimum value (predicted value) may be determined from a value obtained by measuring in advance the minimum current value of a normal shutter depression. This method can determine whether or not the shutter operation is normal even when the shutter drive speed is high and the current rise and the depression overlap.

  As the shutter and solenoid constituting the shutter mechanism are used, the driving force tends to decrease due to changes over time such as scratches and dirt, and the driving time tends to be delayed. On the other hand, since the bottom of the depression of the drive waveform is at the end of the shutter operation, the state of the solenoid can be managed by looking at this time, and maintenance corresponding to changes with time can be put in. In addition, if the operation is slowed down due to a problem, the indentation does not enter the range to be analyzed, and this can be detected as an operation failure.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. The solenoid is not limited to the three-position solenoid shown in FIG. 3, and other types of three-position solenoids may be used. In addition, when only one of the opening operation and the closing operation of the shutter needs to be detected, a normal two-position solenoid (equipped with a single coil and a spring) may be used. Further, two solenoids may be provided for one shutter, and the shutters may be operated in both directions by opening and closing the solenoids alternately. In the above-described embodiment, an example in which the shutter is directly fixed to the shaft of the solenoid and the shutter linearly moves back and forth is shown. However, the present invention can be similarly applied to a case where the shutter swings as in Patent Document 1.

  The shutter mechanism according to the present invention is not limited to the ion beam irradiation time adjusting shutter as shown in the embodiment, and for example, a shutter for shielding frequency adjusting ink for applying a mass load to the piezoelectric element, and patent literature As a shutter mechanism for operating the shutter in two open / close positions, such as a shutter provided in a discharge unit that discharges the recording paper cut by the cutter unit as shown in FIG.

  In the above embodiment, the ion beam is irradiated in the vertical direction from the top to the bottom. However, the ion beam may be irradiated in the vertical direction from the bottom.

It is the schematic of an example of the frequency adjustment apparatus with which the shutter mechanism which concerns on this invention is used. It is the disassembled perspective view which looked at the principal part of the frequency adjusting device shown in FIG. 1 from the ion gun 5 side for etching of FIG. It is sectional drawing which shows the structure of an example of a solenoid, (a) is a neutral position, (b) is a closed position, (c) shows an open position. It is a circuit diagram of an example of the drive detection circuit of a solenoid. It is a figure which shows the electric current change at the time of the drive of a solenoid. It is a figure which shows the area of the hollow at the time of the drive of a solenoid. It is a figure of the example which compares the electric current at the time of the drive of a solenoid with a reference value.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frequency adjusting device 2 Processing chamber 5 Etching ion gun 6 Movable stage 10 Wafer 10a Area 11 Shutter base 12 Solenoid 13 Shaft 14 Shutter 15 Pattern mask 16 Controller 20 Shutter mechanism 120 Frame 121, 122 Coil 123 Fixed magnetic pole 124 Movable iron core 125, 126 Fixed magnetic pole

Claims (11)

A shutter operable in two positions, an open position and a closed position;
In a shutter mechanism comprising: a solenoid that linearly moves a movable iron core by passing a drive current through a coil and that opens and closes the shutter connected to the movable iron core;
Continuously measuring the drive current flowing in the coil when the solenoid is driven;
The step of determining the size of the indentation of the waveform of the drive current, wherein the indentation of the waveform is a counter electromotive force according to the drive speed of the movable core after the drive current has increased from an initial value to a steady value. The drive current is reduced by the following, and then the movable iron core is generated by increasing the drive current to a steady value by reaching a stroke end,
And a step of detecting an opening / closing operation of the shutter based on a size of the dent of the waveform. 2. The operation detection of the shutter mechanism according to claim 1, wherein the step of determining the size of the dent of the waveform is determined by a ratio between a current value of the lowest point of the dent and a current value of the steady value. Method. The method of detecting an operation of the shutter mechanism according to claim 1, wherein the step of determining the size of the corrugated recess is performed based on an area of the corrugated recess. The elapsed time to the lowest point of said depression from the start of driving of the solenoid, the operation detection of the shutter mechanism according to any of claims 1 to 3, comprising a step of detecting an operating time of the movable core Method. The solenoid has two coils arranged at intervals in the axial direction, and is a solenoid that reciprocally drives the movable iron core by passing an electric current alternately through these coils,
Wherein the variation of the driving current flowing through the two coils, the operation detection method of the shutter mechanism according to any of claims 1 to 4, characterized in that to detect the operation of both the opening operation and closing operation of the shutter . A shutter operable in two positions, an open position and a closed position;
In a shutter mechanism comprising: a solenoid that moves a movable iron core by passing a driving current through a coil and that opens and closes the shutter connected to the movable iron core;
Means for continuously measuring the drive current flowing in the coil when the solenoid is driven;
A means for determining the size of the depression of the waveform of the drive current, wherein the depression of the waveform is a counter electromotive force according to the drive speed of the movable iron core after the drive current has increased from an initial value to a steady value. The driving current is reduced by the following, and then the driving iron is generated by increasing the driving current to a steady value by reaching the stroke end,
Means for detecting the opening / closing operation of the shutter according to the size of the dent of the waveform. 7. The operation detection of the shutter mechanism according to claim 6 , wherein the means for determining the size of the dent of the waveform is determined by a ratio between the current value at the lowest point of the dent and the current value of the steady value. apparatus. 7. The operation detecting device for a shutter mechanism according to claim 6 , wherein the means for determining the size of the corrugated recess is determined based on an area of the corrugated recess. The elapsed time to the lowest point of said depression from the start of driving of the solenoid, the operation detection of the shutter mechanism according to any of claims 6 to 8, characterized in that it comprises means for detecting the operating time of the movable core apparatus. The solenoid has two coils arranged at intervals in the axial direction, and is a solenoid that reciprocally drives the movable iron core by passing an electric current alternately through these coils,
From the change of the driving current flowing through the two coils, the operation detecting device of the shutter mechanism according to any of claims 6 to 9, characterized in that detecting the opening operation and the operation of both closing operation of the shutter . An apparatus that adjusts the frequency of the piezoelectric element in the vacuum chamber by irradiating the piezoelectric element with an ion beam using an etching ion gun and adjusting the ion beam irradiation time with a shutter,
A shutter mechanism is arranged in the vacuum chamber,
Frequency adjusting apparatus characterized by operation detecting apparatus according is provided in any one of claims 6 to 10.

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