JP2010208172A - Method for inspecting power supply system - Google Patents

Abstract

It is possible to more easily detect a degree of a resistance value with respect to a reference resistance value of a power feeding system without requiring a measuring device.
Two different drive pulse signals and inspection pulse signals are supplied from a driver IC to a piezoelectric actuator. At this time, the capacitance is calculated by dividing the voltage value of the pulse signal by the total charge amount calculated by integrating the current value flowing through the FPC 50. After that, the contact resistance between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is compared by comparing the capacitance of the capacitor 83 when the drive pulse signal is applied with the capacitance of the capacitor 83 when the detection pulse signal is applied. The degree of magnitude relative to the reference resistance value is detected.
[Selection] Figure 4

Description

  The present invention relates to a feeding system inspection method for feeding power from a driving device to a driving object that operates with charging and discharging.

  2. Description of the Related Art Conventionally, a drive target that operates with charge / discharge and a drive device that supplies power to the drive target are connected to a power supply system. For example, in Patent Document 1, a piezoelectric actuator that is driven with charging and discharging and applies an ejection pressure to ink in an ink flow path formed in a flow path unit, and a power supply to the piezoelectric actuator, which is a driving target, There is disclosed an ink jet head in which a driver IC as a driving device is mounted by a flexible printed circuit (FPC) in which the driver IC is mounted and electrically connected to a plurality of individual electrodes on the surface of the piezoelectric actuator. . In this inkjet head, a plurality of conductive bumps are provided to protrude from a plurality of individual electrodes of the piezoelectric actuator, and a plurality of terminals connected to the driver IC corresponding to the plurality of bumps of the piezoelectric actuator are provided on the FPC. Each is provided. The terminals and the bumps are electrically connected, and the ink jet head applies a voltage to the individual electrodes via the bumps connected to the terminals by supplying a voltage from the driver IC to the terminals. Actuator is driven.

  The power supply system including the FPC that connects the drive device and the drive target includes a considerable amount of resistance components such as wiring resistance. If the resistance value of the power supply system is large, the charge / discharge current is increased. By becoming smaller, the charge / discharge speed of the drive target changes, which may affect the drive of the drive target. For example, the resistance value of the connection portion may increase depending on the bonding state between the FPC terminal and the bump of the piezoelectric actuator, and the resistance value of the power feeding system may increase. In the ink jet head described in Patent Document 1, if the contact between the terminal of the FPC and the bump of the piezoelectric actuator is insufficient, the contact area is small, and the contact resistance increases. Then, the voltage waveform applied to the individual electrode connected to the bump from the driver IC is lost, and the ejection pressure applied to the ink in the ink flow path corresponding to the individual electrode is reduced, and the ejection timing is shifted. Or the desired jetting characteristics cannot be obtained.

Japanese Patent Laying-Open No. 2005-305847 (FIG. 9)

  Therefore, it is desired to measure the resistance value of the power feeding system. In the ink jet head described in Patent Document 1, when the contact resistance between the terminal of the FPC and the bump of the piezoelectric actuator is to be measured, a measuring device is purposely prepared. The contact resistance had to be measured by bringing the probe into contact with the terminals and bumps, which was troublesome.

  Therefore, an object of the present invention is to provide a power feeding system inspection method capable of more easily detecting the magnitude of the resistance value.

  The power feeding system inspection method of the present invention is a power feeding system inspection method in which power is supplied from a driving device to a driving target that operates with charge and discharge, and an inspection pulse signal from the driving device to the driving target. Between the start of charging and the completion of charging, or from the start of discharging to the completion of discharging, of the driving target driven by the inspection pulse signal supplied in the supplying step A calculation step of calculating a total charge amount by one charge or discharge by integrating current values flowing through the power supply system, and a reference resistance of the power supply system based on the total charge amount calculated by the calculation step And a detection step of detecting the degree of the resistance value with respect to the value.

  According to the inspection method of the power feeding system of the present invention, from the start of charging of the driving target whose charge / discharge speed has changed due to the difference in the resistance value of the power feeding system to the middle of charging, or from the beginning of discharging to the middle of discharging. The degree of the magnitude of the resistance value relative to the reference resistance value of the power feeding system can be detected based on the value of the current flowing through the power feeding system. As a result, it is possible to detect the magnitude of the resistance value without using the measuring device when inspecting the power supply system, so that the troublesomeness when using the measuring device is eliminated, and the magnitude of the resistance value is reduced. The degree can be easily detected. The “reference resistance value” refers to the resistance value of the power feeding system when the drive device and the drive target are normally conducted.

  Further, in the supplying step, a first inspection pulse signal set so that charging / discharging of the driving target is not performed completely is supplied from the driving device to the driving target, and in the calculating step, the first checking pulse signal is set. It is preferable to calculate the total charge amount by integrating the current values flowing through the power feeding system between the edges from the rising edge to the falling edge of one inspection pulse signal or between the edges from the falling edge to the rising edge. When an inspection pulse signal that does not completely charge or discharge the drive target is supplied to the drive target, the charge time or discharge time ends in the middle and is insufficient. Compared to charge / discharge. However, since the value of the current flowing through the power supply system per unit time varies depending on the resistance value of the power supply system, the total charge amount during charging or discharging varies. Therefore, the degree of the resistance value with respect to the reference resistance value of the power feeding system can be detected from the total charge amount during charging or discharging.

  Further, in the supplying step, the first inspection pulse signal, which is set so that complete charge and complete discharge of the drive object are repeatedly performed from the driving device to the drive object, A second inspection pulse signal having a different pulse width is supplied, and a value of a current flowing through the power feeding system between the edges of the first inspection pulse signal when the first inspection pulse signal is supplied in the calculation step. The first charge amount is calculated by integration, and the second charge amount is calculated by integrating the current value flowing through the power feeding system between the edges of the second check pulse signal when the second check pulse signal is supplied. In the detection step, the first charge amount is compared with the second charge amount, and the first charge amount is smaller than a predetermined value with respect to the second charge amount. It is preferable to detect a large resistance value of the power supply system to the resistance value of the reference. When the first inspection pulse signal is supplied to the drive target so that charging / discharging ends in the middle, if the resistance value of the power feeding system is larger than the reference resistance value, charging or discharging is performed during the charging or discharging period terminated halfway. The total amount of charge thus made becomes relatively small. Further, when the second inspection pulse signal is supplied to the drive target, the total charge amount at the time of charging or discharging is equal regardless of the magnitude of the resistance value of the power feeding system. Accordingly, when the resistance value of the power feeding system is larger than the reference resistance value, the first charge amount when the first inspection pulse signal is supplied, and the second charge amount when the second inspection pulse signal is supplied. The difference becomes larger. Therefore, when the first charge amount is smaller than a predetermined value with the second charge amount as a reference, it can be detected that the resistance value of the power feeding system is larger than the reference resistance value.

  The second inspection pulse signal is preferably a drive pulse signal supplied from the drive device to the drive target during normal drive. According to this, the drive pulse signal used at the time of normal driving can be used for inspection.

  In addition, in the supplying step, it is preferable that the first inspection pulse signal and the second inspection pulse signal supplied from the driving device to the driving target have the same frequency and different duty ratios. Here, the duty ratio is the ratio of the rising and falling intervals of the pulse signal. In the supplying step, when the duty ratio of the first inspection pulse signal and the second inspection pulse signal is the same and the frequency of the first inspection pulse signal is made larger than the second inspection pulse signal, charging or discharging is performed depending on the frequency characteristics. The total amount of charge at the time becomes small. Therefore, it is difficult to determine whether the total charge amount during charging or discharging has decreased due to the resistance value of the power feeding system, or whether the total charge amount during charging or discharging has decreased due to frequency characteristics. is there. Therefore, by making the duty ratios of the first inspection pulse signal and the second inspection pulse signal different from each other, the reference resistance of the power feeding system can be determined based on the total charge amount during charging or discharging without being affected by the frequency characteristics. The degree of the magnitude of the resistance value with respect to the value can be detected.

  Moreover, it is preferable that the drive target is a piezoelectric actuator. According to this, it is possible to detect the degree of the magnitude of the resistance value with respect to the reference resistance value of the power feeding system between the piezoelectric actuator that is driven along with charging and discharging and the wiring member.

  Further, the drive device and the piezoelectric actuator are electrically connected via a wiring member, and the contact of the piezoelectric actuator and the contact of the wiring member are in contact and electrically connected, It is preferable that the wiring member and the piezoelectric actuator are joined by a resin disposed around. A resistance value generated at a contact point between the contact of the piezoelectric actuator and the contact of the wiring member is included in the resistance value of the power feeding system. Since the contact of the piezoelectric actuator and the contact of the wiring member are in contact with each other and electrically connected, the contact resistance between the contacts is increased compared to the case where the contacts are joined and electrically connected. In such a case, it is easy to detect the degree of the resistance value with respect to the reference resistance value between the contacts. In addition, since the variation in contact resistance has a great influence, it is highly necessary to detect the degree of the resistance value.

  Further, the drive device and the piezoelectric actuator are electrically connected via a wiring member, and the contact of the piezoelectric actuator and the contact of the wiring member are connected by a conductive resin containing metal particles, The wiring member and the piezoelectric actuator may be joined. The resistance value generated in the conductive resin that electrically connects the contact of the piezoelectric actuator and the contact of the wiring member is included in the resistance value of the power feeding system. Resin has a larger resistance than metal, and the resistance value between the contact of the piezoelectric actuator electrically connected via the resin and the contact of the wiring member is increased. In such a case, it is easy to detect the degree of the resistance value with respect to the reference resistance value between the contacts. In addition, since the variation of the resistance value greatly affects, it is highly necessary to detect the degree of the resistance value.

  Based on the value of the current flowing through the power feeding system from the start of charging to the middle of the charging of the drive target whose charging / discharging speed has changed due to the difference in the resistance value of the power feeding system, or from the start of discharging to the middle of discharging. Thus, the degree of the magnitude of the resistance value with respect to the reference resistance value of the power feeding system can be detected. As a result, it is possible to detect the magnitude of the resistance value without using the measuring device when inspecting the power supply system, so that the troublesomeness when using the measuring device is eliminated, and the magnitude of the resistance value is reduced. The degree can be easily detected.

It is a schematic block diagram of an inkjet printer. It is a partial top view of an inkjet head. It is the III-III sectional view taken on the line of FIG. It is an equivalent circuit diagram which shows the electrical structure from a driver IC to a piezoelectric actuator. It is a figure explaining the rounding of the pulse signal applied to a capacitor by the difference in the resistance value of a resistor, (a) is a voltage waveform figure in the point a of Drawing 4, (b) is in the b point of Drawing 4. FIG. 5C is a voltage waveform diagram when the resistance value of the feeding system is small, and FIG. 5C is a voltage waveform diagram when the resistance value of the feeding system at point b in FIG. 4 is large. It is explanatory drawing when a drive pulse signal is supplied in the case of a reference resistance value. It is explanatory drawing when a drive pulse signal is supplied when resistance value is large. It is explanatory drawing when an inspection pulse signal is supplied in the case of a reference resistance value. It is explanatory drawing when an inspection pulse signal is supplied when resistance value is large. It is a figure which shows the electrostatic capacitance according to the duty ratio in the case of a reference | standard resistance value, and when a resistance value is large.

  Next, a preferred embodiment of the present invention will be described. In the present embodiment, power is supplied from a driver IC, which is a driving device, to a piezoelectric actuator that is a driving target via an FPC, so that an ejection pressure is applied to the ink in the ink flow path of the flow path unit, and the ink is discharged from the nozzle. It is an example which applied this invention to the inkjet head which ejects.

  First, an ink jet printer having this ink jet head will be described. FIG. 1 is a schematic configuration diagram of an ink jet printer. As shown in FIG. 1, an inkjet printer 100 includes a carriage 2 that can move in the left-right direction (scanning direction) in FIG. 1, and a serial-type inkjet that is provided on the carriage 2 and that ejects ink onto recording paper P. The head 1 and a transport roller 3 for transporting the recording paper P forward (in the paper feed direction) in FIG. 1 are provided.

  The inkjet head 1 moves in the scanning direction integrally with the carriage 2, and supplies ink supplied from an ink cartridge (not shown) to the recording paper P from the nozzle 20 (see FIGS. 2 and 3) disposed on the lower surface thereof. Inject against. Further, the transport roller 3 transports the recording paper P forward in FIG. Then, the ink jet printer 100 conveys the recording paper P forward by the conveying roller 3 while ejecting ink from the nozzles 20 of the ink jet head 1 to the recording paper P, whereby a desired image, character, or the like is printed on the recording paper P. It is configured to record.

  Next, the inkjet head 1 will be described. FIG. 2 is a partial plan view of the inkjet head. 3 is a cross-sectional view taken along line III-III in FIG.

  As shown in FIGS. 2 and 3, the inkjet head 1 is configured to apply pressure to the flow path unit 4 in which the ink flow path including the nozzle 20 and the pressure chamber 14 is formed, and the ink in the pressure chamber 14. Piezoelectric actuator 5 (drive target) that ejects ink from nozzle 20 of flow path unit 4, driver IC 55 (drive device) that supplies power to piezoelectric actuator 5, and flexible print that electrically connects piezoelectric actuator 5 and driver IC 55 Wiring board (FPC: wiring member) 50. In FIG. 2, the driver IC 55 and the FPC 50 are indicated by virtual lines for the sake of simplicity. Note that the electric system including the wiring of the FPC 50 from the driver IC 55 to the piezoelectric actuator 5 in the present embodiment corresponds to the power supply system in the present invention.

  First, the flow path unit 4 will be described. As shown in FIG. 3, the flow path unit 4 includes a cavity plate 10, a base plate 11, a manifold plate 12, and a nozzle plate 13, and these four plates 10 to 13 are joined in a stacked state. It is configured.

  Among the four plates 10 to 13, the cavity plate 10 located at the uppermost position is formed with a plurality of pressure chambers 14 arranged along a plane. Each pressure chamber 14 is formed in a substantially elliptical shape that is long in the scanning direction in plan view. The plurality of pressure chambers 14 are arranged in a staggered manner along the paper feeding direction. The two pressure chamber rows 21 arranged in a zigzag form a set of pressure chamber groups 22 corresponding to one color ink, and further, a plurality of color inks (for example, cyan, magenta, A plurality of sets of pressure chambers 22 corresponding to four colors (yellow and black) are arranged in the scanning direction. FIG. 2 is a partial top view showing only a partial region of the top surface of the inkjet head 1. Therefore, FIG. 2 shows only two pressure chamber rows 21 belonging to one set of pressure chamber groups 22. It is shown.

  Lower portions of the plurality of pressure chambers 14 formed in the cavity plate 10 are covered with the base plate 11, and the plurality of pressure chambers 14 are opened on the upper surface of the flow path unit 4. Furthermore, the piezoelectric actuator 5 described later is joined to the upper surface of the flow path unit 4, so that the upper portions of the plurality of pressure chambers 14 are covered with the piezoelectric actuator 5. Further, as shown in FIG. 2, the cavity plate is formed with ink supply ports 18 for each set of pressure chamber groups 22, and each ink supply port 18 is located above the inkjet head 1 (in FIG. 2). The ink tank (not shown) is connected to an ink cartridge (not shown), which is arranged on the front side of the sheet).

  As shown in FIGS. 2 and 3, communication holes 15 and 16 are formed at positions where the base plate 11 overlaps both end portions of the pressure chamber 14 in a plan view, respectively. The manifold plate 12 is formed with a plurality of manifold channels 17 extending in the paper feeding direction so as to overlap with the portion of the pressure chamber 14 on the side of the communication hole 15 in plan view. The two manifold channels 17 corresponding to one set of pressure chamber groups 22 (two pressure chamber rows 21) communicate with one ink supply port 18 formed in the cavity plate 10, and ink from the ink tank. Ink is supplied to the manifold channel 17 via the supply port 18. Further, a plurality of communication holes 19 respectively connected to the plurality of communication holes 16 are provided at positions where the manifold plate 12 overlaps with the end portions on the opposite side to the end portions communicating with the manifold channels 17 of the plurality of pressure chambers 14 in plan view. Is formed.

  Further, a plurality of nozzles 20 are respectively formed at positions where the nozzle plate 13 overlaps the plurality of communication holes 19 in plan view. As shown in FIG. 2, the nozzles 20 are arranged so as to overlap with the ends of the corresponding pressure chambers 14 opposite to the ends communicating with the manifold channel 17. Thus, the plurality of nozzles 20 are arranged in a staggered manner corresponding to the plurality of pressure chambers 14 respectively.

  As shown in FIG. 3, the manifold channel 17 communicates with the pressure chamber 14 through the communication hole 15, and the pressure chamber 14 communicates with the nozzle 20 through the communication holes 16 and 19. As described above, a plurality of individual ink flow paths from the manifold flow path 17 through the pressure chambers 14 to the nozzles 20 are formed in the flow path unit 4.

  Next, the piezoelectric actuator 5 will be described. As shown in FIGS. 2 and 3, the piezoelectric actuator 5 includes a vibration plate 30 joined to the upper surface of the flow path unit 4 so as to cover the plurality of pressure chambers 14, and an upper surface (the pressure chamber 14 and the pressure chamber 14). The piezoelectric layer 31 disposed to face the plurality of pressure chambers 14, the plurality of individual electrodes 32 disposed on the upper surface of the piezoelectric layer 31, and the plurality of individual electrodes 32. And a plurality of bumps 62 respectively protruding from the terminal portion 35.

  The diaphragm 30 is a substantially rectangular metal plate in plan view, and is made of, for example, an iron-based alloy such as stainless steel, a copper-based alloy, a nickel-based alloy, or a titanium-based alloy. The diaphragm 30 is joined to the upper surface of the cavity plate 10 so as to cover the plurality of pressure chambers 14. Further, the upper surface of the conductive diaphragm 30 also serves as a common electrode that sandwiches the piezoelectric layer 31 between the plurality of individual electrodes 32 and generates an electric field in the thickness direction in the piezoelectric layer 31. The diaphragm 30 as the common electrode is connected to the driver IC 55 via a ground wiring (not shown) of the FPC 50 and is always held at the ground potential.

  Further, on the upper surface of the vibration plate 30, a piezoelectric layer 31 made of a piezoelectric material mainly composed of lead zirconate titanate (PZT), which is a solid solution and is a ferroelectric substance, is formed of lead titanate and lead zirconate. Has been. The piezoelectric layer 31 is continuously formed so as to cover the plurality of pressure chambers 14.

  On the upper surface of the piezoelectric layer 31, a plurality of individual electrodes 32 having a substantially elliptical planar shape that is slightly smaller than the pressure chambers 14 are formed in regions facing the central portions of the plurality of pressure chambers 14, respectively. The individual electrode 32 is made of a conductive material such as gold, copper, silver, palladium, platinum, or titanium.

  Further, a plurality of terminal portions 35 made of a conductive material like the individual electrodes 32 are drawn from the end portions of the plurality of individual electrodes 32 on the side of the communication hole 15 to the outer region beyond the peripheral edge of the pressure chamber 14. . A plurality of bumps 62 made of a conductive material such as silver protrude from the plurality of terminal portions 35. The plurality of bumps 62 are in contact with and electrically connected to the land 53 of the FPC 50. Each individual electrode 32 is electrically connected to a driver IC 55 (see FIG. 2) mounted on the FPC 50 via a bump 62 and a land 53 of the FPC 50.

  Next, the FPC 50 on which the driver IC 55 is mounted will be described. As shown in FIG. 3, the FPC 50 includes a base material 51 and a plurality of lands 53 provided on the lower surface of the base material 51 (a surface facing the piezoelectric actuator 5 in FIG. 3). The FPC 50 is disposed above the piezoelectric actuator 5 with a predetermined interval, and is drawn out in the scanning direction.

  The base material 51 is made of an insulating resin material such as polyimide and has flexibility. A plurality of lands 53 made of a conductive material such as silver or platinum are respectively provided on the lower surface of the substrate 51 so as to face the plurality of bumps 62, and each land 53 is in contact with the bump 62. .

  Further, a thermosetting synthetic resin layer 63 such as an epoxy resin is formed on the lower surface of the substrate 51. The synthetic resin layer 63 covers the surfaces of the bumps 62 and the lands 53 to join the FPC 50 and the diaphragm 30.

  A driver IC 55 is mounted in an area drawn out in the scanning direction of the FPC 50. The driver IC 55 is connected to a plurality of wirings (not shown) of the FPC 50, and is electrically connected to the plurality of lands 53 through the plurality of wirings, and is connected to the plurality of lands 53 and the plurality of bumps 62. By supplying a drive pulse signal to each of the plurality of individual electrodes 32, the potential of these individual electrodes 32 is switched between a predetermined drive potential and a ground potential.

  Next, the operation of the piezoelectric actuator 5 during ink ejection will be described. When a predetermined drive potential is applied to a certain individual electrode 32 from the driver IC 55, between the individual electrode 32 to which this drive potential is applied and the diaphragm 30 as a common electrode held at the ground potential. A potential difference is generated, and an electric field in the thickness direction is generated in the piezoelectric layer 31 in the drive region sandwiched between the individual electrode 32 and the diaphragm 30. When the polarization direction of the piezoelectric layer 31 is the same as the direction of the electric field, the piezoelectric layer 31 contracts in a plane direction orthogonal to the thickness direction that is the polarization direction.

  Here, since the lower diaphragm 30 of the piezoelectric layer 31 is fixed to the cavity plate 10, the diaphragm 30 is contracted in the surface direction as the piezoelectric layer 31 positioned on the upper surface of the diaphragm 30 contracts in the surface direction. The portion covering the pressure chamber 14 is deformed so as to protrude toward the pressure chamber 14 (unimorph deformation). In the piezoelectric actuator 5 according to the present embodiment, the diaphragm 30 waits until ink is ejected in a state where the diaphragm 30 is deformed as described above. When the ink is ejected, the driver IC 55 stops applying the driving potential to the individual electrode 32 from the state where the driving potential is applied to the individual electrode 32. As a result, the potential of the individual electrode 32 becomes the ground potential, the diaphragm 30 returns to its original shape, the volume in the pressure chamber 14 increases, and a pressure wave is generated in the pressure chamber 14.

  Here, as is conventionally known, when the pressure wave accompanying the volume increase of the pressure chamber 14 propagates one way in the longitudinal direction of the pressure chamber 14, the pressure in the pressure chamber 14 becomes positive. Turn. Therefore, the driver IC 55 applies the driving potential to the individual electrode 32 again at the timing when the pressure in the pressure chamber 14 turns positive. At this time, since the pressure wave accompanying the increase in the volume of the pressure chamber 14 and the pressure wave generated when the diaphragm 30 is convexly deformed toward the pressure chamber 14 are combined, the ink in the pressure chamber 14 is large. Pressure is applied and ink is ejected from the nozzles 20.

  Next, an electrical configuration from the driver IC 55 to the piezoelectric actuator 5 will be described. FIG. 4 is an equivalent circuit diagram showing an electrical configuration from the driver IC to the piezoelectric actuator. FIG. 5 is a diagram for explaining the rounding of the pulse signal applied to the capacitor due to the difference in the resistance value of the power feeding system, (a) is a voltage waveform diagram at point a in FIG. 4, and (b) is FIG. 5 is a voltage waveform diagram when the resistance value of the power feeding system at point b is small, and (c) is a voltage waveform diagram when the resistance value of the power feeding system at point b in FIG. 4 is large.

  As shown in FIG. 4, when the piezoelectric actuator 5 is a driving target, the driver IC 55 can be regarded as a driving device that drives the piezoelectric actuator 5. The drive region of the piezoelectric layer 31 that is sandwiched and polarized between the individual electrode 32 and the diaphragm 30 of the piezoelectric actuator 5 can be regarded as a capacitor 83 that performs charging and discharging, and the land 53 of the FPC 50 and the piezoelectric actuator. The contact portion of the five bumps 62 can be regarded as the resistor 84 included in the power feeding system. Note that an ideal resistance value of the resistor 84 when the land 53 and the bump 62 are in contact with each other while securing a sufficient contact area is a normal resistance value (reference resistance value).

  As described above, the inkjet head 1 includes an RC in which a resistor 84 is connected in series in the middle of a power feeding system that applies a voltage from a driver IC 55 that is a driving device to a capacitor 83 that charges and discharges the piezoelectric actuator 5 that is a driving target. It can be regarded as a circuit.

  If the electrical configuration from the driver IC 55 to the piezoelectric actuator 5 is such an RC circuit, the time constant increases as the resistance value of the power feeding system increases, and the drive pulse supplied from the driver IC 55 The signal is distorted when applied to the capacitor 83.

  For example, as shown in FIG. 5A, a drive pulse signal with a duty ratio of 50% is supplied from the driver IC 55. Then, if the resistance value of the power feeding system is small, as shown in FIG. 5B, the voltage waveform of the drive pulse signal applied to the capacitor 83 is slightly reduced, the rise time becomes Tr1, and the fall time becomes Tf1. Become. At this time, the capacitor 83 is repeatedly fully charged and completely discharged, and Tr1 = Tf1.

  However, when the same drive pulse signal is supplied, if the resistance value of the power feeding system is large, the voltage waveform of the drive pulse signal applied to the capacitor 83 becomes large as shown in FIG. The time becomes Tr2 longer than Tr1, and the fall time becomes Tf2 longer than Tf1. Also at this time, the capacitor 83 is repeatedly fully charged and completely discharged, and Tr2 = Tf2. As described above, the magnitude of the resistance value of the power feeding system greatly affects the voltage waveform of the drive pulse signal applied to the capacitor 83.

  The resistance component of the power supply system includes various resistance components such as a wiring resistance of a wiring (not shown) of the FPC 50. In particular, the contact resistance between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 (resistance value of the resistor 84). Accounts for a large percentage.

  This is because the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 are not joined but simply contacted and electrically connected. The contact resistance between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5, that is, the resistance value of the resistor 84 is correlated with the size of the contact area between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5. When is small, the resistance value is large.

  For example, the contact between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is insufficient due to insufficient pressing of the FPC 50 and the piezoelectric actuator 5. (The resistance value of the resistor 84) increases. Then, the voltage waveform of the drive pulse signal applied from the driver IC 55 to the individual electrode 32 of the piezoelectric actuator 5 is lost, and the ejection pressure applied to the ink in the ink flow path corresponding to the individual electrode 32 is reduced. The injection timing is shifted and desired injection characteristics cannot be obtained. As described above, when the contact resistance between the land 53 and the bump 62 is large, it becomes impossible to obtain the reference jetting characteristic. Therefore, this contact resistance that occupies the largest proportion of the resistance components of the power feeding system (the resistance of the resistor 84). I want to measure the resistance value of the power supply system including the value.

  However, in order to measure the contact resistance between the land 53 and the bump 62, it is necessary to prepare a measuring device and measure the contact resistance by bringing the probe of this measuring device into contact with the land 53 and the bump 62, respectively. It was troublesome. Further, it takes a very long time to measure the contact resistance between all the lands 53 formed on the inkjet head 1 and the bumps 62. Further, since the space between the FPC 50 and the piezoelectric actuator 5 is very narrow, it is technically difficult to directly measure the contact resistance by inserting the probe of the measuring device there. Therefore, it is conceivable to measure the contact area between the land 53 and the bump 62 and estimate the contact resistance from this contact area. However, the FPC 50 and the piezoelectric actuator 5 are pressed against each other for a predetermined pressing time, and the land 53 and the bump are pressed. Since only 62 is in contact, it was difficult to measure the contact area.

  For these reasons, in this embodiment, this contact resistance (resistance value of the resistor 84) that occupies the largest proportion of the resistance components of the power feeding system is regarded as the resistance value of the power feeding system. Then, while applying a pulse signal from the driver IC 55 to the individual electrode 32 of the piezoelectric actuator 5, based on the total charge amount calculated by integrating the current value flowing through the wiring of the FPC 50 connecting them, the land 53 The degree of the magnitude of the contact resistance (that is, the resistance value of the resistor 84) with respect to the reference resistance value at the contact portion of the bump 62 is detected. FIG. 6 is an explanatory diagram when a drive pulse signal is supplied in the case of a reference resistance value. FIG. 7 is an explanatory diagram when a drive pulse signal is supplied when the resistance value is large. FIG. 8 is an explanatory diagram when an inspection pulse signal is supplied in the case of a reference resistance value. FIG. 9 is an explanatory diagram when an inspection pulse signal is supplied when the resistance value is large. FIG. 10 is a diagram showing the capacitance according to the duty ratio when the reference resistance value is large and when the resistance value is large. 6-9, (a) is the voltage waveform at point a in FIG. 4, (b) is the voltage waveform at point b in FIG. 4, and (c) is the current at point c in FIG. It is a waveform.

  In order to detect the contact resistance with respect to the reference resistance value, that is, the degree of the resistance value of the resistor 84, the piezoelectric layer 31 when a drive pulse signal and an inspection pulse signal to be described later are applied from the driver IC 55 to the individual electrode 32. , That is, the capacitance of the capacitor 83 is calculated. Then, the capacitances of the capacitors 83 when the two pulse signals are applied are compared, and the degree of the resistance value with respect to the reference resistance value of the resistor 84 is detected.

  First, a method for calculating the capacitance of the capacitor 83 when a drive pulse signal (second inspection pulse signal) is applied from the driver IC 55 to the individual electrode 32 will be described. The drive pulse signal is a pulse signal applied to the individual electrode 32 corresponding to the nozzle 20 when ink is ejected from the nozzle 20 of the flow path unit 4 when the inkjet head 1 is normally driven. It is a pulse signal having a predetermined pulse width set so that charging and complete discharging are repeated. In the present embodiment, a pulse signal having a frequency of 20 kHz and a duty ratio of 50% is used as a drive pulse signal.

  As shown in FIG. 6A, when a drive pulse signal is supplied from the driver IC 55 (supply process), as shown in FIG. 6B, a drive pulse signal having a slightly reduced voltage waveform is applied to the capacitor 83. Is done. At this time, at the time of voltage application from the rising edge to the falling edge of the drive pulse signal, as shown in FIG. 6C, the current value I1 is applied to the FPC 50 during the time Tr1 until the capacitor 83 is fully charged. A positive current that gradually approaches zero as a peak flows, and when charging is completed, no current flows through the FPC 50.

  Further, when no voltage is applied from the falling edge to the rising edge of the drive pulse signal, the FPC 50 has a negative value that gradually approaches zero with the current value −I1 as a peak during the time Tf1 until the capacitor 83 is completely discharged. When a current in the direction flows and the discharge is completed, no current flows in the FPC 50.

The current flowing through the FPC 50 is the amount of charge flowing through the FPC 50 per unit time regardless of whether it is positive or negative. The capacitance of the capacitor 83 is the amount of charge stored in the capacitor 83 per unit voltage. Therefore, when the current value flowing through the FPC 50 between the edges from the rising edge to the falling edge of the drive pulse signal is integrated (time integration), the total amount of charge charged in the capacitor 83 within that time is calculated (see Equation 1). The electrostatic capacity of the capacitor 83 is calculated by dividing the total charge amount by the voltage value when the voltage of the drive pulse signal is applied (calculation step: see formula 2). Note that the electrostatic capacity in the present embodiment is different from the electrostatic capacity of the capacitor 83 and indicates the capacity that is calculated by the above-described method and is apparently exchanged when the capacitor 83 is charged and discharged. The total amount of charge charged in the capacitor 83 is the area S1 in FIG. The total amount of charge (area S1) charged in the capacitor 83 between the edges from the rising edge to the falling edge of the drive pulse signal is the total amount discharged from the capacitor 83 between the edges from the falling edge to the rising edge of the drive pulse signal. It is the same as the charge amount (area S2).

  Next, the inspection pulse signal (first inspection pulse signal) is a pulse signal having a pulse width different from that of the drive pulse signal, which is set so that the capacitor 83 is not completely charged and discharged. In this embodiment, a pulse signal having a frequency of 20 kHz and a duty ratio of 10% is used as an inspection pulse signal. That is, the drive pulse signal and the inspection pulse signal are pulse signals having the same frequency but different duty ratios.

  As shown in FIG. 8A, when an inspection pulse signal is supplied from the driver IC 55, an inspection pulse signal having a slightly reduced voltage waveform is applied to the capacitor 83 as shown in FIG. 8B. At this time, when the voltage is applied from the rising edge to the falling edge of the inspection pulse signal, as shown in FIG. 8C, the voltage application time is short and the capacitor 83 is not fully charged. During the current time Tr5, a positive current that continuously approaches zero with the current value I1 as a peak continues to flow through the FPC 50.

  In addition, when no voltage is applied from the falling edge to the rising edge of the inspection pulse signal, the current value −I1 is applied to the FPC 50 only for a short time Tf5 until the capacitor 83 that is not fully charged is completely discharged. A negative current that gradually approaches zero as a peak flows, and when the discharge is completed, no current flows through the FPC 50.

  When the value of the current flowing through the FPC 50 between the rising and falling edges of the inspection pulse signal is integrated, the total charge amount (area S5) charged in the capacitor 83 is calculated, and the voltage of the inspection pulse signal is calculated as the total charge amount. By dividing the voltage value at the time of application, the capacitance of the capacitor 83 is calculated. The total charge amount (area S5) charged in the capacitor 83 between the edges from the rising edge to the falling edge of the inspection pulse signal is the total amount discharged from the capacitor 83 between the edges from the falling edge to the rising edge of the inspection pulse signal. It is the same as the charge amount (area S6).

  Here, when the drive pulse signal is applied, even if the contact state between the land 53 and the bump 62 is normal or insufficient, that is, the resistance value of the resistor 84 is large even at the reference value. However, the capacitance of the capacitor 83 has the same value.

  This is because the capacitor 83 alternately repeats full charge and complete discharge regardless of the resistance value of the resistor 84. Specifically, when the contact state between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is insufficient and the contact resistance is large, a drive pulse signal is supplied from the driver IC 55 as shown in FIG. As shown in FIG. 7B, a drive pulse signal having an increased voltage waveform is applied to the capacitor 83. At this time, when a voltage is applied from the rising edge to the falling edge of the drive pulse signal, as shown in FIG. 7C, during the time Tr4 until the capacitor 83 is fully charged, the FPC 50 has a current value I1. However, when a current in the positive direction gradually approaches zero with a small current value I2 as a peak flows and the charging is completed, no current flows in the FPC 50.

  Further, when no voltage is applied from the falling edge to the rising edge of the drive pulse signal, the FPC 50 has a current value −I2 smaller than the current value −I1 as a peak during the time Tf4 until the capacitor 83 is completely discharged. When a negative current that gradually approaches zero flows and discharge is completed, no current flows through the FPC 50.

  At this time, the value of the current flowing through the FPC 50 is reduced as a whole, but since the time during which the current is flowing becomes longer, the total charge amount charged in the capacitor 83 between the edges from the rising edge to the falling edge of the drive pulse signal ( The area S5) is the same as the area S1 in FIG. The total amount of charge (area S5) charged in the capacitor 83 between the edges from the rising edge to the falling edge of the drive pulse signal is the total amount discharged from the capacitor 83 between the edges from the falling edge to the rising edge of the drive pulse signal. The same is true for the amount of charge (area S6).

  However, when the inspection pulse signal is applied, when the contact state between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is insufficient, the contact resistance is larger than when it is normal (the resistance value of the resistor 84 is As a result, the current flowing through the FPC 50 is reduced, the inspection pulse signal has a smaller duty ratio than the drive pulse signal, and the voltage application time is short, so that the capacitor 83 is not fully charged / discharged. The electric capacity becomes smaller.

  Specifically, when the contact state between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is insufficient and the contact resistance is large, an inspection pulse signal is supplied from the driver IC 55 as shown in FIG. As shown in FIG. 9B, a test pulse signal having an increased voltage waveform is applied to the capacitor 83. At this time, when the voltage is applied from the rising edge to the falling edge of the inspection pulse signal, as shown in FIG. 9C, the voltage application time is short and the capacitor 83 is not fully charged. During the current time Tr6, the FPC 50 continues to flow a positive current that gradually approaches zero with a current value I2 smaller than the current value I1 as a peak.

  In addition, when no voltage is applied from the falling edge to the rising edge of the inspection pulse signal, the FPC 50 has a current value −I1 higher than the current value −I1 only for a short time Tf6 until the capacitor 83 that is not fully charged is completely discharged. A negative current that gradually approaches zero with a small current value −I2 as a peak flows, and when the discharge is completed, no current flows in the FPC 50. The total amount of charge (area S7) charged in the capacitor 83 between the edges from the rising edge to the falling edge of the drive pulse signal is the total amount discharged from the capacitor 83 between the edges from the falling edge to the rising edge of the drive pulse signal. It is the same as the charge amount (area S8). Further, the area S7 is a value smaller than the area S5 in FIG.

  That is, when the contact state between the land 53 and the bump 62 is normal (when the resistance value of the resistor 84 is a reference value), the capacitance of the capacitor 83 when the drive pulse signal is applied, and when the inspection pulse signal is applied When the contact state between the land 53 and the bump 62 is insufficient (when the resistance value of the resistor 84 is large) compared to the difference between the capacitance of the capacitor 83 and the capacitance of the capacitor 83 when the drive pulse signal is applied. The difference between the capacitance and the capacitance of the capacitor 83 when the inspection pulse signal is applied increases.

  Therefore, when the capacitance of the capacitor 83 when the inspection pulse signal is applied is smaller than the capacitance of the capacitor 83 when the drive pulse signal is applied, the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 It is possible to detect that the contact state is insufficient and the contact resistance is larger than the reference resistance value.

  As described above, the capacitance of the capacitor 83 when the drive pulse signal is applied and the detection are calculated by supplying two different drive pulse signals and inspection pulse signals from the driver IC 55 provided in advance in the inkjet head 1. By comparing the capacitance of the capacitor 83 when the pulse signal is applied, a measuring device is not required, and the degree of magnitude of the contact resistance between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 with respect to the reference resistance value can be obtained. It can be detected more easily. In addition, it is possible to quickly detect the magnitude of the contact resistance with respect to a normal contact state between all the lands 53 formed on the inkjet head 1 and the bumps 62. Further, when the contact resistance between the land 53 and the bump 62 is relatively large as described above, the variation in the contact resistance greatly affects the ejection characteristics of the ink jet head 1, and therefore it is necessary to detect the degree of the resistance value. High nature.

  The inspection pulse signal may be any pulse signal as long as it has a pulse width different from that of the drive pulse signal, which is set so that the capacitor 83 is not completely charged and discharged. For example, a pulse signal having a frequency of 20 kHz and a duty ratio of 90% may be used.

  When such an inspection pulse signal having a duty ratio of 90% is applied from the driver IC 55 to the individual electrode 32, current is supplied to the FPC 50 until the capacitor 83 is fully charged when a voltage is applied from the rising edge to the falling edge of the inspection pulse signal. When the flow and charging are completed, no current flows through the FPC 50.

  Further, when no voltage is applied from the falling edge to the rising edge of the inspection pulse signal, the capacitor 83 is not completely discharged, so that a current continues to flow through the FPC 50. Immediately thereafter, the drive pulse signal rises, so that charging is completed immediately and current does not flow immediately through the FPC 50.

  When the current value flowing through the FPC 50 between the edges from the rising edge to the falling edge of the inspection pulse signal is integrated, the total charge amount charged in the capacitor 83 is calculated, and the voltage at the time of applying the voltage of the inspection pulse signal is calculated as the total charge amount. By dividing the value, the capacitance of the capacitor 83 is calculated. At this time, when the inspection pulse signal is applied, when the contact state between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is insufficient, the contact resistance is larger than the normal state (the resistance value of the resistor 84). Therefore, the current flowing through the FPC 50 is small, the duty ratio of the inspection pulse signal is larger than that of the driving pulse signal, and the capacitor 83 is not fully charged and discharged because the voltage non-application time is short. The electrostatic capacity of becomes small.

  From these, as shown in FIG. 10, when a pulse signal with a duty ratio of about 50% is supplied from the driver IC 55, the capacitor 83 repeats full charge / discharge, so regardless of the contact resistance between the land 53 and the bump 62, When a pulse signal with a duty ratio of 0% or near 100% is supplied from the driver IC 55 with the same capacitance, the capacitor 83 repeats insufficient charge / discharge, and the contact resistance between the land 53 and the bump 62 is large. Increases and the capacitance decreases.

  Using such a calculation method, the capacitance between the five lands 53 and the bumps 62 is calculated while changing the duty ratio. These five locations are sequentially designated as ch1 to ch5. Table 1 shows the capacitance between the land 53 of each FPC 50 and the bump 62 of the piezoelectric actuator 5 for each duty ratio of the pulse signal supplied from the driver IC.

  As shown in Table 1, the capacitances of ch1 to ch5 are maximized when the duty ratio is 50%, and become smaller as the duty ratio becomes larger or smaller. At this time, for example, when the capacitance when the duty ratio is 10% is smaller than the capacitance when the duty ratio is 10% by 20 pF or more, and the contact resistance is large, It can be detected that it is larger than the reference resistance value.

  Next, modified examples in which various changes are made to the present embodiment will be described. However, components having the same configuration as in the above embodiment are given the same reference numerals and description thereof is omitted as appropriate.

  In the present embodiment, the drive pulse signal and the inspection pulse signal have the same frequency and have different duty ratios. However, if the inspection pulse signal is a pulse signal that cannot completely charge and discharge the capacitor 83, The frequency may be different from that of the driving pulse signal. In this case, since the duty ratio between the drive pulse signal and the inspection pulse signal is fixed, it is easy to vary the frequency. However, as the frequency is increased, the resistance of the capacitor 83 itself increases due to the frequency characteristics. That is, if the frequency of the inspection pulse signal is made larger than the drive pulse signal, the total charge amount at the time of charging or discharging becomes small due to the frequency characteristics. Then, it cannot be determined whether the total charge amount at the time of charging or discharging is reduced or the total charge amount at the time of charging or discharging is reduced by the frequency characteristic depending on the resistance value of the resistor 84. . For this reason, it is preferable to detect the degree of magnitude of the contact resistance with respect to the reference resistance value without being affected by the frequency characteristics by making the duty ratios of the drive pulse signal and the inspection pulse signal different.

  In this embodiment, the total charge amount charged in the capacitor 83 calculated by integrating the current value flowing through the FPC 50 between the edges at the time of charging from the rising edge to the falling edge of the pulse signal is added to the total charge amount charged in the capacitor 83. The capacitance of the capacitor 83 is calculated by dividing the voltage value at the time of voltage application, but the capacitance of the capacitor 83 is similarly changed between the edges at the time of discharge from the falling edge to the rising edge of the pulse signal. It may be calculated.

  Furthermore, in this embodiment, the magnitude of the contact resistance is detected by comparing the capacitance of the capacitor 83 when the drive pulse signal is applied and when the inspection pulse signal is applied. The magnitude of the contact resistance with respect to the reference resistance value without calculating the capacitance from the total amount of charge charged in the capacitor 83, which is calculated by integrating the current values flowing through the FPC 50 when the inspection pulse signal is applied. May be detected.

  In the present embodiment, the degree of the contact resistance is detected from the difference in capacitance between the capacitors 83 when the drive pulse signal and the inspection pulse signal are applied. By applying an inspection pulse signal, the capacitances of the plurality of capacitors 83 are relatively compared, and it may be detected that the resistance of the resistor 84 connected in series with the capacitor 83 having an extremely small value is large. .

  In the present embodiment, the land 53 that is the connection target on the FPC 50 side and the bump 62 protruding from the terminal portion 35 that is the connection target on the piezoelectric actuator 5 side are brought into electrical contact with each other, and the periphery thereof The FPC 50 and the piezoelectric actuator 5 are joined by the synthetic resin layer 63 disposed on the land. The land 53 that is the connection target on the FPC 50 side and the terminal portion 35 that is the connection target on the piezoelectric actuator 5 side are connected, for example, differently. The FPC 50 and the piezoelectric actuator 5 may be bonded together while being electrically connected by a conductive thermosetting resin containing metal particles such as an isotropic conductive adhesive. The resistance value generated in the resin that electrically connects the terminal portion 35 of the piezoelectric actuator 5 and the land 53 of the FPC 50 is included in the resistance value of the power feeding system. Resin has a larger resistance than metal, and the resistance value between the terminal portion 35 of the piezoelectric actuator 5 and the land 53 of the FPC 50 electrically connected via the resin is increased. Even in such a case, it is easy to detect the degree of the resistance value with respect to the reference resistance value between the terminal portion 35 and the FPC 50.

  Furthermore, in this embodiment, the magnitude of the contact resistance with respect to the reference resistance value is detected from the difference in capacitance of the capacitor 83 when the drive pulse signal and the inspection pulse signal are supplied. When the signal is supplied, the total charge amount calculated by integrating the current value flowing through the FPC 50 from the beginning of charging to the middle of charging or from the beginning of discharging to the middle of discharging is completely charged or discharged. The magnitude of the contact resistance relative to the reference resistance value may be detected by comparing the total charge amount calculated by integrating the current values flowing through the FPC 50.

  Furthermore, in this embodiment, the magnitude of the contact resistance with respect to the reference resistance value is detected from the difference in capacitance of the capacitor 83 when the driving pulse signal and the inspection pulse signal are supplied. When the capacitance of the capacitor 83 at the time is known in advance, only the inspection pulse signal is supplied without supplying the drive pulse signal, and the capacitance of the capacitor 83 and the reference resistance value at this time are supplied. The degree of magnitude of the contact resistance with respect to the reference resistance value may be detected from the difference from the capacitance of the capacitor 83 at that time.

  In the present embodiment, the contact resistance between the land 53 of the FPC 50 and the bump 62 of the piezoelectric actuator 5 is described as an example of the resistance generated in the power supply system, but in addition, the power supply including the wiring resistance of the wiring of the FPC 50 is included. It is possible to detect the degree of the resistance value with respect to the reference resistance value of the resistance component of the entire system. At this time, the reference resistance value is an ideal resistance value when there is no leakage in the power feeding system.

  Furthermore, in the present embodiment, the degree of magnitude of the contact resistance with respect to the reference resistance value is determined from the difference in capacitance of the capacitor 83 when the drive pulse signal and the inspection pulse signal supplied during normal driving of the piezoelectric actuator are supplied. Although it has been detected, the pulse signal is not limited to the drive pulse signal, and any pulse signal that is repeatedly charged and discharged may be used.

  Further, the present invention is not limited to the case where power is supplied to the piezoelectric actuator from the driver IC via the FPC, and the present invention can be applied to any device as long as it is a driving target that operates with charge / discharge. Is possible.

DESCRIPTION OF SYMBOLS 1 Inkjet head 4 Flow path unit 5 Piezoelectric actuator 41 Cavity plate 50 FPC
53 Land 55 Driver IC
62 Bump 100 Inkjet printer

Claims (8)

A method for inspecting a power feeding system that feeds power from a driving device to a driving object that operates with charging and discharging,
A supplying step of supplying an inspection pulse signal from the driving device to the driving target;
The value of the current flowing through the power feeding system from the start of charging to the middle of completion of charging or from the start of discharging to the middle of completion of discharging of the drive target driven by the inspection pulse signal supplied in the supply step And calculating a total charge amount by one charge or discharge,
And a detection step of detecting a degree of the resistance value with respect to a reference resistance value of the power supply system based on the total charge amount calculated in the calculation step. Method. In the supplying step, supplying a first inspection pulse signal set so that charging / discharging of the driving target is not completely performed from the driving device to the driving target;
In the calculation step, a total charge amount is calculated by integrating current values flowing through the power feeding system between edges from the rising edge to the falling edge of the first inspection pulse signal or between edges from the falling edge to the rising edge. The power feeding system inspection method according to claim 1, wherein: In the supplying step, the first inspection pulse signal and a pulse different from the first inspection pulse, which is set so that the complete charging and complete discharging of the driving object are repeatedly performed from the driving device to the driving object. Providing a second inspection pulse signal having a width;
In the calculating step, when the first inspection pulse signal is supplied, a current value flowing through the power feeding system between the edges of the first inspection pulse signal is integrated to calculate a first charge amount. The second charge amount is calculated by integrating the current value flowing through the power feeding system between the edges of the second check pulse signal when the two check pulse signals are supplied;
In the detection step, the first charge amount is compared with the second charge amount, and when the first charge amount is smaller than a predetermined value with respect to the second charge amount, 3. The inspection method for a power feeding system according to claim 2, wherein the resistance value of the power feeding system is detected to be large.   The power feeding system inspection method according to claim 3, wherein the second inspection pulse signal is a driving pulse signal supplied from the driving device to the driving target during normal driving.   5. The supply step, wherein the first inspection pulse signal and the second inspection pulse signal supplied from the driving device to the driving target have the same frequency and different duty ratios. 5. A method for inspecting a power feeding system according to 5.   The power feeding system inspection method according to claim 1, wherein the driving target is a piezoelectric actuator. The driving device and the piezoelectric actuator are electrically connected via a wiring member,
The wiring member and the piezoelectric actuator are joined to each other by a resin disposed around the contact in a state where the contact of the piezoelectric actuator and the contact of the wiring member are in electrical contact with each other. An inspection method for a power feeding system according to claim 6. The driving device and the piezoelectric actuator are electrically connected via a wiring member,
The power supply according to claim 6, wherein the contact of the piezoelectric actuator and the contact of the wiring member are connected by a conductive resin containing metal particles, and the wiring member and the piezoelectric actuator are joined. System inspection method.

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