JP2006321200A - Method for setting bias voltage of liquid injection head, liquid injection apparatus, and method for controlling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for setting a bias voltage by which a proper bias voltage is set for every liquid injection head, and the property is improved for delivering an ink. <P>SOLUTION: The setting method of bias voltage is applied to the liquid injection head which is equipped with a passage forming substrate with a pressure generating chamber communicating with nozzle ports and a piezoelectric actuator formed on the passage forming substrate. The property for the bias voltage of the liquid injection head is detected by the setting method. Based on the detected result, the bias voltage value applied to the piezoelectric actuator is set for the every liquid injection head. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for setting a bias voltage of a liquid ejecting head, a method for controlling a liquid ejecting apparatus, and a liquid ejecting apparatus.

  When manufacturing a liquid ejecting head, extremely fine processing and assembly in units of micrometers are performed. For this reason, the thickness and area of the elastic plate, the shape of the pressure generating chamber, the size of the nozzle opening, and the like vary from one liquid ejecting head to another, which may adversely affect the ink ejection characteristics in the pressure generating chamber.

In view of such circumstances, a method has been proposed for stably ejecting ink while enabling mass production of liquid ejecting heads and eliminating variations in the quality of the liquid ejecting heads. For example, a method has been proposed in which a natural vibration period of ink pressure in a pressure generation chamber is measured, a rank determined based on the period is given, and a drive signal corresponding to the rank is set in a liquid ejecting head (Patent Document 1). ).
JP 2002-154212 A

  However, the ink ejection characteristics are influenced not only by the natural oscillation period of the ink pressure in the pressure generation chamber but also by the driving characteristics of the piezoelectric elements that constitute the piezoelectric actuator with respect to the bias voltage. As a result of investigations by the inventors, even in a liquid ejecting head manufactured with the same specifications (materials, processes, etc.), the displacement amount characteristic of the piezoelectric element with respect to the bias voltage (hereinafter referred to as “bias voltage characteristic”) It was found that each jet head was different.

  FIG. 7 shows the result of studying the bias voltage characteristics of the liquid jet head. The investigation of the bias voltage characteristics of the liquid ejecting head is performed by using the liquid ejecting heads X and Y manufactured with the same specifications, and the piezoelectric voltage when only the bias voltage is changed with the driving voltage applied to the liquid ejecting head being constant. This was done by determining the amount of displacement of the piezoelectric element constituting the actuator.

  As shown in FIG. 7, it is clear that the liquid ejecting head X and the liquid ejecting head Y have different displacement amounts of the piezoelectric elements that are displaced according to the applied bias voltage. FIG. 7 shows that the liquid ejecting head X has a larger displacement than the liquid ejecting head Y when the same bias voltage is applied. Therefore, when the same bias voltage is uniformly applied to the liquid ejecting head on which the liquid ejecting head is mounted, the characteristics differ for each liquid ejecting head. In the case of a head unit composed of a plurality of liquid ejecting heads, the displacement amount of the piezoelectric element constituting the piezoelectric actuator varies depending on the liquid ejecting heads, resulting in variations in characteristics such as the amount of ejected ink and the flying speed of the ink. It will be.

  However, the current situation is that the bias voltage applied to the liquid ejecting head is uniform for all the liquid ejecting heads. In order to correct such variations in bias voltage characteristics, a method of setting the driving voltage for each liquid ejecting head is conceivable. However, if the correction is made with the driving voltage, the circuit becomes large, and thus the density tends to increase. There was a problem with the design of some liquid jet heads.

  Further, in order to obtain a desired amount of displacement under a situation where the bias voltage is not properly set, it is necessary to apply a higher drive voltage. If voltage is continuously applied under such circumstances, there is a problem that a load is applied to the piezoelectric element and the life of the piezoelectric element is shortened.

  Accordingly, an object of the present invention is to provide a method for manufacturing a liquid ejecting head in which an appropriate bias voltage is set for each liquid ejecting head and ink ejection characteristics are improved.

  In order to solve the above problems, the present invention provides a bias voltage for a liquid jet head including a flow path forming substrate having a pressure generating chamber communicating with a nozzle opening, and a piezoelectric actuator formed on the flow path forming substrate. A setting method for detecting a characteristic of a liquid ejecting head with respect to a bias voltage, and setting a bias voltage value to be applied to the piezoelectric actuator for each liquid ejecting head based on the detection result. A method for setting a bias voltage of an ejection head is provided.

  With such a configuration, an appropriate bias voltage can be set for each liquid ejecting head, so that the ink ejection characteristics can be improved and the life of the piezoelectric actuator can be improved.

  Preferred embodiments of the invention are as follows. The bias voltage value applied to the piezoelectric actuator is preferably set to a value at which the displacement amount of the piezoelectric actuator is the largest or a value close to the value. With such a configuration, the performance of the liquid ejecting head can be always used in a high state.

  The bias voltage value applied to the piezoelectric actuator is preferably set to a value that minimizes the difference in displacement between the plurality of piezoelectric actuators formed on the liquid ejecting head. With such a configuration, an appropriate bias voltage can be set even when the bias voltage characteristics differ between the piezoelectric actuators.

  According to another aspect of the invention, there is provided a liquid jet head including a flow path forming substrate having a pressure generation chamber communicating with the nozzle opening, a piezoelectric actuator formed on the flow path forming substrate, and a bias voltage with respect to the piezoelectric actuator. And a bias power supply circuit for applying the liquid jet head to the liquid jet apparatus, comprising: a step of detecting a characteristic of the liquid jet head with respect to a bias voltage for each liquid jet head; A step of ranking the ejection heads, a step of determining a bias voltage value to be applied to each liquid ejection head based on the ranking result, and a step of setting the determined bias voltage values in the bias power supply circuit, respectively And a method of controlling a liquid ejecting apparatus.

  With such a configuration, an appropriate bias voltage can be set for each liquid ejecting head, so that the ink ejection characteristics can be improved and the life of the piezoelectric actuator can be improved. Further, even when a head unit including a plurality of liquid ejecting heads is configured, since the bias voltage is set for each liquid ejecting head, the ink ejection characteristics do not vary.

  Preferred embodiments of the invention are as follows. The bias voltage value is preferably set to a value at which the displacement amount of the piezoelectric actuator is the largest or a value close to the value. With such a configuration, the performance of the liquid ejecting head can be always used in a high state.

  According to another aspect of the invention, there is provided a liquid jet head including a flow path forming substrate having a pressure generation chamber communicating with the nozzle opening, a piezoelectric actuator formed on the flow path forming substrate, and a bias voltage with respect to the piezoelectric actuator. And a detection unit that detects a characteristic of the liquid jet head with respect to the bias voltage and sets a bias voltage value to be applied to the bias power circuit based on the detection result. Is to provide.

  Next, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is an exploded perspective view illustrating a liquid ejecting head, and FIG. 2 is a plan view and a cross-sectional view of FIG. As shown in FIGS. 1 and 2, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in the present embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation. An elastic film 50 having a thickness of 1 to 2 μm is formed. The flow path forming substrate 10 includes two rows of pressure generating chambers 12 partitioned by a plurality of partition walls in the longitudinal direction. Further, a communication portion 13 is formed on the outer side in the longitudinal direction of the pressure generation chambers 12 in each row, and the communication portion 13 and each pressure generation chamber 12 are connected via an ink supply path 14 provided for each pressure generation chamber 12. Communicated. The communication unit 13 constitutes a part of a reservoir that communicates with a reservoir unit 33 of the sealing substrate 30 described later and serves as a common ink chamber for the pressure generation chambers 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

Further, a nozzle plate 20 having a nozzle opening 21 communicating with the side opposite to the ink supply path 14 of each pressure generating chamber 12 on the opening surface side of the flow path forming substrate 10 is an adhesive, a heat-welded film, or the like. It is fixed through. The nozzle plate 20 has a thickness of, for example, 0.03 to 0.3 mm, a linear expansion coefficient of 300 ° C. or less, and a glass ceramic of, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.]. It consists of a silicon single crystal substrate or non-rust steel. The nozzle plate 20 entirely covers one surface of the flow path forming substrate 10 on one surface, and also serves as a reinforcing plate that protects the silicon single crystal substrate that is the flow path forming substrate 10 from impact and external force.

  On the other hand, an insulating film 55 having a thickness of, for example, about 0.4 μm is formed on the elastic film 50 opposite to the opening surface of the flow path forming substrate 10. Are stacked with a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1 μm, and an upper electrode film 80 having a thickness of, for example, about 0.05 μm. Thus, the piezoelectric element 300 is formed. Here, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80. In general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber. Further, here, the piezoelectric element 300 and the vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In the present embodiment, the elastic film 50, the insulator film 55, and the lower electrode film 60 function as a diaphragm.

  Here, to the upper electrode film 80, which is an individual electrode of the piezoelectric element 300, lead electrodes 90 drawn from the vicinity of the longitudinal end of the piezoelectric element 300 to the region outside the pressure generation chamber 12 are respectively connected. The lead electrode 90 is made of, for example, gold (Au) or the like, and is extended from the vicinity of the longitudinal end of the piezoelectric element 300 to a region corresponding to the space between the rows of the pressure generating chambers 12 in this embodiment. Further, in this embodiment, the lower electrode film 60 that is a common electrode of the piezoelectric element 300 is patterned in a region facing the vicinity of both ends in the longitudinal direction of the pressure generation chamber 12 and along the parallel direction of the pressure generation chambers 12. The pressure generation chambers 12 extend to the outer region. The lower electrode film 60 in a region corresponding to each row of pressure generation chambers 12 is continuous in a region outside the row of pressure generation chambers 12.

  On the piezoelectric element 300 side of the flow path forming substrate 10, a sealing substrate 30 having a piezoelectric element holding portion 31 that seals the space is secured in a state where a space that does not hinder the movement of the piezoelectric element 300 is secured. . In the present embodiment, the piezoelectric element holding portion 31 includes a row of piezoelectric elements 300 (in FIG. 2) provided in each region facing each piezoelectric element 300, that is, each region facing each row of pressure generation chambers 12. 300a and 300b) are sealed. Further, a penetrating portion 32 that penetrates the sealing substrate 30 in the thickness direction is provided between the piezoelectric element holding portions 31, that is, in a region corresponding to the central portion of the sealing substrate 30. The leading end portion of the lead electrode 90 drawn out from the upper electrode film 80 is exposed in the through portion 32, and each lead electrode 90 is electrically connected via the connection wiring 120 extending in the through portion 32. It is connected.

  In addition, the sealing substrate 30 is provided with a reservoir portion 33 that constitutes at least a part of the reservoir 100 serving as an ink chamber common to the pressure generation chambers 12. In this embodiment, the reservoir portion 33 is formed through the sealing substrate 30 in the thickness direction and across the width direction of the pressure generation chamber 12, and is provided through the elastic film 50 and the insulator film 55. A reservoir 100 is formed which communicates with the communicating portion 13 of the flow path forming substrate 10 through the formed through hole and serves as a common ink chamber for the pressure generating chambers 12. In addition, two drive ICs 110 for driving the piezoelectric elements 300 for each column are mounted on both sides of the through portion 32 on the sealing substrate 30. The drive IC 110 and the vicinity of the end exposed in the through portion 32 of each lead electrode 90 are electrically connected by a drive wiring 120 made of a bonding wire.

  Note that a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded to a region corresponding to the reservoir portion 33 of the sealing substrate 30. Here, the sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and the sealing film 41 seals one surface of the reservoir portion 33. It has been stopped. The fixing plate 42 is formed of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 100 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 100 is sealed only with a flexible sealing film 41. Has been.

  The liquid ejecting head configured as described above takes in ink from an external ink supply unit (not shown), fills the interior from the reservoir 100 to the nozzle opening 21, and then fills the inside with ink, and then according to a recording signal from the driving IC 110, the upper electrode film 80. By applying a voltage between the elastic film 50, the insulator film 55, the lower electrode film 60, and the piezoelectric layer 70, the pressure in the pressure generation chamber 12 is increased and the nozzle opening is increased. Ink droplets are ejected from 21.

  In the present embodiment, the characteristics with respect to the bias voltage are detected for such a liquid jet head. In this embodiment, three liquid ejecting heads A, B, and C (not shown) are used as the liquid ejecting heads, and the displacement amount of the piezoelectric element 300 that constitutes the piezoelectric actuator that is displaced according to the bias voltage is measured. A case where the bias voltage characteristic of the head is detected will be described.

  FIG. 3 is a diagram illustrating the bias voltage characteristics of the liquid ejecting heads A, B, and C (not shown). Note that the bias voltage characteristics can be examined, for example, by fixing the drive voltage, changing only the bias voltage, and measuring the displacement amount of the piezoelectric element that is displaced according to each bias voltage. In the figure, a curve 101 shows the bias voltage characteristic of the liquid jet head A, a curve 102 shows the bias voltage characteristic of the liquid jet head B, and a curve 103 shows the bias voltage characteristic of the liquid jet head C. Point a, point b, and point c indicate the bias voltage (V) when the displacement amount of the piezoelectric elements of the liquid jet heads A, B, and C is the largest.

  As shown in FIG. 3, the bias voltage characteristics are different for each of the liquid jet heads A, B, and C. The bias voltage value (V) at which the displacement amount of the piezoelectric element is the largest is different for each liquid ejecting head A, B, and C. That is, in the case of the liquid ejecting head A, when the bias voltage value (V) is a value indicated by a, in the case of the liquid ejecting head B, the liquid ejecting head C is obtained when the bias voltage value (V) is a value indicated by b. In this case, the largest displacement amount is obtained when the bias voltage value (V) is a value indicated by c. This indicates that the optimum bias voltage value (V) is different for each liquid ejecting head. Accordingly, the liquid ejecting head A sets the bias voltage value to a, the liquid ejecting head B sets the bias voltage value to b, and the liquid ejecting head C sets the bias voltage value to c. As described above, by determining the bias voltage value (V) at which the maximum displacement amount is obtained for each liquid ejecting head, it is possible to always exhibit optimum ink ejection characteristics.

  The bias voltage value (V) set for each liquid ejecting head is preferably set to a value at which the displacement amount of the piezoelectric element is maximized. However, the bias voltage value (V) is not necessarily maximum as long as a certain performance required for the liquid ejecting head is satisfied. There is no need to set a bias voltage value (V) that provides a displacement amount, and a bias voltage value (V) that is close to the bias voltage value (V) that provides the maximum displacement amount within an allowable range is set. May be.

  Further, when setting the bias voltage value (V), the bias voltage characteristics are examined for each liquid ejecting head in the above example. However, the bias voltage characteristics for each of a plurality of piezoelectric actuators formed in one liquid ejecting head. May be detected. For example, the bias voltage characteristic is detected for each row of the piezoelectric elements 300a and 300b in FIG. 2, and the bias voltage value (V) is set so that the difference in displacement amount between the piezoelectric elements 300a and 300b is minimized. Also good.

(Embodiment 2)
The second embodiment is a case where a head unit including a plurality of liquid ejecting heads is configured. In the present embodiment, first, a case where the head unit includes two liquid ejecting heads will be described. In the present embodiment, the displacement amount of the piezoelectric element 300 that is displaced according to the bias voltage is measured using the four liquid ejecting heads D, E, F, and G, and the bias voltage characteristics of each liquid ejecting head are examined. An example is shown.

  FIG. 4A is a diagram illustrating the bias voltage characteristics of the liquid jet heads D, E, F, and G. As in the case of the first embodiment, the bias voltage characteristics were examined by fixing the drive voltage, changing only the bias voltage, and measuring the displacement amount of the piezoelectric element displaced according to each bias voltage. In the figure, a curve 104 shows the bias voltage characteristic of the liquid ejecting head D, a curve 105 shows the bias voltage characteristic of the liquid ejecting head E, a curve 106 shows the bias voltage characteristic of the liquid ejecting head F, and a curve 107 shows the liquid ejecting head. The bias voltage characteristics of the head G are shown. A point p indicates a bias voltage value (V) when the displacement amount of the piezoelectric elements of the liquid ejecting heads D and E becomes the largest, and a point q indicates a displacement amount of the piezoelectric elements of the liquid ejecting heads F and G. The bias voltage value (V) at the maximum is shown.

  Based on such a difference in bias voltage characteristics, the liquid ejecting heads are ranked. The ranking conditions can be arbitrarily set. For example, as shown in Table 1 below, four ranks from rank 1 to rank 4 according to the inspection bias voltage (V) at the peak value of the displacement amount of the piezoelectric actuator. Settings can be made. When the peak value of the displacement amount of the piezoelectric actuator is out of the predetermined range, the liquid ejecting head can be handled as rank 0 (nonconforming).

  As shown in FIG. 4A, the bias voltage characteristics are substantially the same in the liquid ejecting heads D and E (curves 104 and 5) and the liquid ejecting heads F and G (curves 106 and 7). In this case, the liquid ejecting heads D and E are classified into rank 2, and the liquid ejecting heads F and G are classified into rank 4. Accordingly, when a head unit including two liquid ejecting heads is manufactured, the liquid ejecting heads D and E are selected and combined, and the liquid ejecting heads F and G are selected and combined. A bias voltage (i to d) preset for each rank is applied to the head unit in which the liquid ejecting heads D and E are combined. Thereby, even when the head unit is constituted by a plurality of liquid ejecting heads, the ink ejection characteristics can be made uniform.

  FIG. 4B is a diagram showing an example of the above combination. As described above, the liquid ejecting heads D and E are classified into rank 2, and the liquid ejecting heads F and G are classified into rank 4. Each optimum bias voltage value (V) is set.

  The method for setting the bias voltage of the head unit composed of two liquid ejecting heads has been described above. Next, the method for setting the bias voltage of the head unit composed of four liquid ejecting heads will be described using the above example. .

  As shown in FIG. 4A, the bias voltage characteristics of the liquid ejecting head D (curve 104), the liquid ejecting head E (curve 105), the liquid ejecting head F (curve 106), and the liquid ejecting head G (curve 107). As a result of detection, it is found that the bias voltage value (V) indicated by X is a bias voltage at which the displacement amount of the piezoelectric actuator of each liquid ejecting head is the same. Therefore, when a head unit is configured using four liquid ejecting heads (DG), the common bias voltage value (V) of the four liquid ejecting heads is detected and ranked as described above. As a result, an optimum bias voltage can be set. In the example of FIG. 4A, since the bias voltage indicated by X is a common bias voltage for the four liquid ejecting heads, this common bias voltage is detected. Then, the bias voltage (A) classified into rank 1 based on the ranking and set in advance to rank 1 is applied.

(Embodiment 3)
In the third embodiment, a method of controlling the bias voltage of a head unit including four liquid ejecting heads with an ink jet printer will be described. For ease of understanding, the liquid ejecting head will be described using the four liquid ejecting heads (D to G) used in the second embodiment.

  FIG. 5 is a functional block diagram illustrating a part of the configuration of an inkjet printer including a head unit including four liquid ejecting heads. As shown in FIG. 5, the ink jet printer has a printer main body 1 and a head unit 2.

  The printer body 1 includes an external interface 3 that receives print data including multi-level hierarchical information from a host computer (not shown), and a RAM 4 that stores various data such as print data including multi-level hierarchical information. A ROM 5 storing routines for performing various data processing, a control unit 6 including a CPU, a bias power supply circuit (Vbs circuit) 7 for applying a bias voltage to the liquid jet heads (heads D to G), A detection unit 8 that detects the bias voltage characteristics of the liquid jet heads (heads D to G), and an internal interface 9 that functions to apply a bias voltage applied from a bias power supply circuit (Vbs circuit) 7 to the head unit 2. And.

  As shown in FIG. 5, the head unit 2 includes four liquid ejecting heads (heads D to G), and each liquid ejecting head (heads D to G) is connected to the printer main body 1 via a cable. Has been.

  FIG. 6 is a diagram showing an outline of processing in the detection unit 8. The detection unit 8 detects bias voltage characteristics for the four liquid jet heads (heads D to G) mounted on the head unit 2 (ST1). Here, a bias voltage value (V) at which the displacement amount of the piezoelectric element of each liquid ejecting head (heads 1 to 4) is the same is detected and ranked (ST2). The ranking conditions can be arbitrarily set. For example, as shown in Table 1, ranks 1 to 4 are set according to the bias voltage (V) at the peak value of the displacement amount of the piezoelectric actuator. In addition, when the peak value of the displacement amount of the piezoelectric actuator is out of a predetermined range, the liquid ejecting head can be handled as nonconforming (0: error).

  Further, since the bias voltage value (V) is set for each rank, the bias voltage value (V) to be applied to the liquid jet heads (heads 1 to 4) is determined based on the rank information (ST3). Information on the determined bias voltage value (V) is stored in the ROM 5 (ST4). When the ink jet printer is in operation, the control unit 6 supplies a bias voltage to be applied to the head unit 2 to the bias power supply circuit 7 based on information stored in the ROM 5, and applies it to the head unit 2 via the internal interface 9.

  In the above description, an ink jet recording head and an ink jet recording apparatus that discharge ink are given as examples. However, the present invention broadly covers liquid ejecting heads and liquid ejecting apparatuses in general. Examples of the liquid ejecting head include a recording head used in an image recording apparatus such as a printer, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an organic EL display, and an electrode formation such as an FED (surface emitting display). Examples thereof include an electrode material ejecting head used in manufacturing, a bioorganic matter ejecting head used in biochip manufacturing, and the like.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. It is a figure which shows the bias voltage characteristic of the piezoelectric element unit A, B, and C. It is a figure which shows the bias voltage characteristic of the piezoelectric element unit D, E, F, and G. FIG. 5 is a functional block diagram illustrating a part of the configuration of an ink jet printer including a head unit including four liquid ejecting heads. It is the figure which showed the outline | summary of the process in the detection part. It is a figure which shows the result of having examined the bias voltage characteristic of a piezoelectric element unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Flow path formation board | substrate, 12 ... Pressure generation chamber, 13 ... Communication part, 14 ... Ink supply path, 20 ... Nozzle plate, 21 ... Nozzle opening, 30 ... Sealing board | substrate, 31 ... Piezoelectric element holding part, 32 ... Through Reference numeral 33: Reservoir part 40: Compliance substrate 41 Sealing film 42 Fixed plate 43 Opening 50 Elastic film 55 Insulator film 60 Lower electrode film 70 Piezoelectric layer , 80 ... Upper electrode film, 90 ... Lead electrode, 100 ... Reservoir, 120 ... Connection wiring, 300 ... Piezoelectric element, 110 ... Drive IC, 1 ... Printer body, 2 ... Head unit 3 ... External interface, 6 ... Control unit, 7 ... Bias power supply circuit, 8 ... Detector, 9 ... Internal interface

Claims (6)

A method for setting a bias voltage of a liquid ejecting head comprising: a flow path forming substrate having a pressure generation chamber communicating with a nozzle opening; and a piezoelectric actuator formed on the flow path forming substrate,
Detecting a characteristic of the liquid jet head with respect to a bias voltage;
A bias voltage setting method for a liquid ejecting head, wherein a bias voltage value applied to the piezoelectric actuator is set for each liquid ejecting head based on the detection result.   The bias voltage setting method for a liquid jet head according to claim 1, wherein a bias voltage value applied to the piezoelectric actuator is set to a value at which a displacement amount of the piezoelectric actuator is maximized or a value close to the value.   The bias of the liquid ejecting head according to claim 1, wherein a bias voltage value applied to the piezoelectric actuator is set to a value that minimizes a difference in displacement between the plurality of piezoelectric actuators formed on the liquid ejecting head. How to set the voltage. A liquid ejecting head including a flow path forming substrate having a pressure generating chamber communicating with the nozzle opening, and a piezoelectric actuator formed on the flow path forming substrate;
A bias power supply circuit for applying a bias voltage to the piezoelectric actuator;
A control method for a liquid ejecting apparatus comprising:
Detecting a characteristic of the liquid jet head with respect to a bias voltage for each liquid jet head;
Ranking the liquid jet head based on the detection result;
Determining a bias voltage value to be applied to each liquid ejecting head based on the ranking result;
A step of setting each determined bias voltage value in the bias power supply circuit, respectively.   5. The method of controlling a liquid ejecting apparatus according to claim 4, wherein the bias voltage value is a value at which a displacement amount of the piezoelectric actuator is maximized or a value close to the value. A liquid ejecting head including a flow path forming substrate having a pressure generating chamber communicating with the nozzle opening, and a piezoelectric actuator formed on the flow path forming substrate;
A bias power supply circuit for applying a bias voltage to the piezoelectric actuator;
Detecting a characteristic of the liquid jet head with respect to a bias voltage, and setting a bias voltage value to be applied to the bias power supply circuit based on the detection result;
A liquid ejecting apparatus comprising:

Images