JP7244806B2 - liquid injector - Google Patents

Description

The present invention relates to a liquid ejecting apparatus having a liquid ejecting head that ejects liquid from nozzle openings, a controller connectable to the liquid ejecting apparatus, a recording system including the controller, and a program for controlling the controller.

A liquid ejecting apparatus having a liquid ejecting head that ejects liquid droplets includes an ink jet recording head that generates pressure in a pressure generating chamber by a pressure generating means and ejects ink droplets from nozzles communicating with the pressure generating chamber. An ink jet recording device is mentioned.

The ink jet recording head installed in such an ink jet recording apparatus may cause ejection failures of ink droplets. Technologies for detection have also been developed.

Further, there is proposed a technique of correcting image data and completing printing without stopping printing when a non-ejecting nozzle occurs during printing and an image defect occurs (for example, see Patent Document 1). .

Here, as an ink jet recording head using a piezoelectric actuator, a nozzle plate provided with nozzle openings and a channel forming substrate provided with pressure generating chambers communicating with the nozzle openings are adhered with an adhesive or the like. have been proposed (see, for example, Patent Document 1).

JP 2009-172966 A

However, when an ejection failure such as dot dropout occurs, there is a problem that if printing is continued after that, it cannot be recovered by cleaning or the like. As a result of continuing the state of being warmed by the hot platen in a non-ejection state, the ink solidifies and recovery becomes impossible.

In particular, when using high-viscosity ink, pigment ink, latex ink containing a water-soluble polymer, ultraviolet curing ink, or the like, there is a high possibility that ejection failure that cannot be recovered occurs.

It should be noted that such problems are not limited to ink jet recording apparatuses, but also exist in liquid ejecting apparatuses that eject liquids other than ink. Further, the same applies to recording systems in which a control device (host device) and a recording device (printer) are wired or wirelessly connected to perform recording.

In view of such circumstances, the present invention provides a liquid ejecting apparatus, a control device, a recording system, and a program capable of preventing deterioration of ejection failure without stopping ejection of liquid droplets onto an ejection receiving medium. With the goal.

A mode of the present invention for solving the above problems is a liquid jet head comprising a plurality of nozzle openings for ejecting liquid, pressure generating means for generating pressure changes in pressure generating chambers communicating with the nozzle openings, respectively; The nozzle for ejecting droplets according to print data, comprising: detecting means for detecting ejection failure of droplets of the liquid ejecting head for each of the nozzle openings; and control means for controlling the pressure generating means. The pressure generating means corresponding to the openings is driven by a discharge operation, and the pressure generating means corresponding to the nozzle openings that do not discharge liquid droplets are driven by a micro-vibration operation that gives minute vibrations without discharging in order to prevent thickening. In the liquid ejecting apparatus, the control means controls the pressure generating means, and when the control means detects the ejection failure during a printing operation, the control means adjusts the pressure corresponding to the nozzle opening in which the ejection failure is detected. The pressure generating means is operated in an ejection prohibition mode in which driving for the ejection operation or the micro-vibration operation by the generating means is completely prohibited, and the printing operation is continued using nozzle openings other than the nozzle opening in which the ejection failure has been detected. The liquid ejecting apparatus is characterized in that the control means continues control of the pressure generating means in the ejection prohibition mode until it is determined that the printing operation has ended.
In this aspect, when an ejection failure is detected during printing, the driving of the pressure generating means corresponding to the ejection failure nozzle opening is completely prohibited. can be reliably recovered by the recovery processing of .
Here, in the ejection prohibition mode, the control means prohibits driving for a flushing operation, an ejection operation, and a micro-vibration operation by the pressure generation means corresponding to the nozzle opening in which the ejection failure is detected. Preferably, the pressure generating means is controlled.
Moreover, it is preferable that the control unit performs a recovery process after determining that the printing operation has ended. According to this, it is possible to avoid interruption of printing in the middle, and it is possible to reliably recover the ejection failure of the nozzle opening in which the ejection failure has occurred by the predetermined recovery process without exacerbating the ejection failure.
Further, when continuing printing using nozzle openings other than the nozzle opening for which the ejection failure has been detected in the ejection prohibition mode, the control means prevents ejection from the nozzle opening for which the ejection failure has been detected for other nozzle openings. It is preferable to continue printing with print data supplemented by ejection from the nozzle. According to this, it is possible to prevent deterioration of print quality even if ejection failure occurs.
Moreover, it is preferable that the detection means detects an excessive voltage generated in the pressure generation means after driving the pressure generation means, and detects an ejection failure in the state of the vibration. According to this, it is possible to detect an ejection failure almost simultaneously during printing.
According to another aspect of the present invention, there is provided a liquid ejecting head including a plurality of nozzle openings for ejecting liquid, pressure generating means for generating pressure changes in pressure generating chambers communicating with the nozzle openings, respectively; The liquid ejecting head includes a detection unit for detecting ejection failure of the liquid droplets for each of the nozzle openings, and a control unit for controlling the pressure generation unit, wherein the control unit detects the ejection failure during a printing operation. In this case, the pressure generating means corresponding to the nozzle opening for which the ejection failure has been detected is prohibited from driving for the ejection operation or the micro-vibration operation, and the printing is performed using the nozzle openings other than the nozzle opening for which the ejection failure has been detected. The pressure generating means is controlled in a discharge prohibition mode in which the operation is continued, and the control means continues to control the pressure generating means in the discharge prohibition mode until it is determined that the printing operation has ended. in the liquid injection device.
In this aspect, when an ejection failure is detected during printing, the driving of the pressure generating means corresponding to the ejection failure nozzle opening is completely prohibited. can be reliably recovered by the recovery processing of .

Here, it is preferable that the control unit implements recovery processing after determining that the printing operation has ended. According to this, it is possible to avoid interruption of printing in the middle, and it is possible to reliably recover the ejection failure of the nozzle opening in which the ejection failure has occurred by the predetermined recovery process without exacerbating the ejection failure.

Further, when continuing printing using nozzle openings other than the nozzle opening for which the ejection failure has been detected in the ejection prohibition mode, the control means prevents ejection from the nozzle opening for which the ejection failure has been detected for other nozzle openings. It is preferable to continue printing with print data supplemented by ejection from the nozzle. According to this, it is possible to prevent deterioration of print quality even if ejection failure occurs.

Moreover, it is preferable that the detection means detects an excessive voltage generated in the pressure generation means after driving the pressure generation means, and detects an ejection failure in the state of the vibration. According to this, it is possible to detect an ejection failure almost simultaneously during printing.

Another aspect of the present invention is a liquid jet head including a plurality of nozzle openings for ejecting liquid, and pressure generating means for generating pressure changes in pressure generating chambers respectively communicating with the nozzle openings, and the liquid ejecting head. A detection means for detecting ejection failure of the head for each nozzle opening, and a control means for controlling the pressure generation means, wherein the control means detects the ejection failure during recording, The liquid ejecting apparatus is characterized by having an ejection prohibition mode for prohibiting driving of the pressure generating means corresponding to the nozzle opening in which the ejection failure is detected.
In this aspect, when an ejection failure is detected during printing, the driving of the pressure generating means corresponding to the ejection failure nozzle opening is completely prohibited. can be reliably recovered by the recovery processing of .
Here, it is preferable that, in the ejection prohibition mode, the control means continue printing using nozzle openings other than the nozzle opening in which the ejection failure has been detected. According to this, it is possible to avoid interruption of printing in the middle, and it is possible to reliably recover the ejection failure of the nozzle opening in which the ejection failure has occurred by the predetermined recovery process without exacerbating the ejection failure.
Further, when continuing printing using nozzle openings other than the nozzle opening for which the ejection failure has been detected in the ejection prohibition mode, the control means prevents ejection from the nozzle opening for which the ejection failure has been detected for other nozzle openings. It is preferable to continue printing with print data supplemented by ejection from the nozzle. According to this, it is possible to prevent deterioration of print quality even if ejection failure occurs.
Moreover, it is preferable that the detection means detects an excessive voltage generated in the pressure generation means after driving the pressure generation means, and detects an ejection failure in the state of the vibration. According to this, it is possible to detect an ejection failure almost simultaneously during printing.

Another aspect of the present invention includes a liquid jet head including a plurality of nozzle openings for ejecting liquid, and pressure generating means for generating pressure changes in pressure generating chambers respectively communicating with the nozzle openings. A control device connectable to a liquid ejecting apparatus, comprising a control unit that generates and transmits a control command including information for causing the liquid ejecting apparatus to execute printing, wherein the control unit controls the liquid ejecting operation of the printing apparatus. An ejection failure of droplets of the head is detected for each of the nozzle openings, and when the ejection failure is detected during recording, subsequent driving of the pressure generating means corresponding to the nozzle opening in which the ejection failure is detected is prohibited. The control device is characterized in that it has a discharge prohibition mode.
In such a mode, when an ejection failure is detected during printing, control is performed so as to completely prohibit the driving of the pressure generating means corresponding to the nozzle opening with the ejection failure. However, it is possible to reliably recover by a predetermined recovery process.
Here, it is preferable that, in the ejection prohibition mode, the control unit continues printing using nozzle openings other than the nozzle opening in which the ejection failure has been detected. According to this, it is possible to avoid interruption of printing in the middle, and it is possible to reliably recover the ejection failure of the nozzle opening in which the ejection failure has occurred by the predetermined recovery process without exacerbating the ejection failure.
Further, when continuing printing using nozzle openings other than the nozzle opening for which the ejection failure has been detected in the ejection prohibition mode, the control unit prevents ejection from the nozzle opening for which the ejection failure has been detected for other nozzle openings. It is preferable to continue printing using print data complemented by ejection from the nozzle. According to this, it is possible to prevent deterioration of print quality even if ejection failure occurs.
Further, it is preferable that the ejection failure is detected by detecting an excessive voltage generated in the pressure generating means after the pressure generating means is driven, and detecting the state of the vibration. According to this, it is possible to detect an ejection failure almost simultaneously during printing.

Another aspect of the present invention is the control device described above, and a liquid ejecting device connectable to the control device, comprising: a plurality of nozzle openings for ejecting liquid; and pressure generating chambers communicating with the nozzle openings, respectively. and a liquid ejecting apparatus including a liquid ejecting head.
In this aspect, when an ejection failure is detected during printing, the recording apparatus is controlled so as to completely prohibit the driving of the pressure generating means corresponding to the ejection failure nozzle opening. can be reliably recovered by a predetermined recovery process without deteriorating.

Another aspect of the present invention includes a liquid jet head including a plurality of nozzle openings for ejecting liquid, and pressure generating means for generating pressure changes in pressure generating chambers respectively communicating with the nozzle openings. A program executed by a control unit that controls a control device connectable to a liquid ejecting apparatus, wherein the control unit detects ejection failures of liquid droplets of the liquid ejecting head of the liquid ejecting apparatus for each of the nozzle openings. and an ejection inhibition mode in which, when the ejection failure is detected during recording, subsequent driving of the pressure generating means for causing a pressure change in the pressure generating chamber communicating with the nozzle opening in which the ejection failure was detected is prohibited. A program characterized by executing
In this aspect, when an ejection failure is detected during printing, the control device can be made to function so as to completely prohibit the driving of the pressure generating means corresponding to the nozzle opening with the ejection failure. The opening can be reliably recovered by a predetermined recovery process without exacerbating the ejection failure.

1 is a schematic perspective view of a recording apparatus according to Embodiment 1 of the present invention; FIG. 1 is an exploded perspective view of a print head according to Embodiment 1 of the present invention; FIG. 1 is a plan view of a recording head according to Embodiment 1 of the present invention; FIG. 1 is a cross-sectional view of a recording head according to Embodiment 1 of the present invention; FIG. 2 is a block diagram showing the control configuration of the printing apparatus according to Embodiment 1 of the present invention; FIG. 4 is a flow chart showing the operation of the recording apparatus according to Embodiment 1 of the present invention; 2 is a schematic configuration diagram of a recording system according to Embodiment 2 of the present invention; FIG.

The present invention will be described in detail below based on embodiments.
(Embodiment 1)
FIG. 1 is a schematic perspective view of an ink jet recording apparatus, which is an example of a liquid ejecting apparatus according to an embodiment of the invention.

The liquid ejecting apparatus of this embodiment is, for example, an ink jet recording apparatus. As shown in FIG. 1, a recording head unit 1 having an ink jet recording head, which will be described later in detail, includes an ink cartridge 2 that constitutes ink supply means. is detachably provided, and a carriage 3 on which the recording head unit 1 is mounted is provided axially movably on a carriage shaft 5 attached to an apparatus main body 4 . This recording head unit 1 ejects a black ink composition and a color ink composition.

A drive motor 6 is provided near one end of the carriage shaft 5, and a first pulley 6a having a groove on its outer periphery is provided at the tip of the shaft of the drive motor 6. As shown in FIG. Further, near the other end of the carriage shaft 5, a second pulley 6b corresponding to the first pulley 6a of the drive motor 6 is rotatably provided. A timing belt 7 made of an elastic material such as rubber is looped between the two parts 6b.

The driving force of the driving motor 6 is transmitted to the carriage 3 via the timing belt 7 , so that the carriage 3 on which the recording head unit 1 is mounted is moved along the carriage shaft 5 . On the other hand, a transport roller 8 is provided as transport means, and a recording sheet S, which is a recording medium such as paper, is transported by the transport roller 8 . The conveying means for conveying the recording sheet S is not limited to the conveying roller, and may be a belt, a drum, or the like.

An ink jet recording apparatus installed in such an ink jet recording apparatus will be described. 2 is an exploded perspective view of an ink jet recording head which is an example of the liquid jet head according to Embodiment 1 of the present invention, FIG. 3 is a plan view of the ink jet recording head, and FIG. 1 is a cross-sectional view taken along the line AA' of FIG.

As shown in the figure, pressure generating chambers 12 are formed in a channel forming substrate 10 provided in an ink jet recording head II, which is an example of the liquid jet head of the present embodiment. The pressure generating chambers 12 partitioned by the plurality of partition walls 11 are arranged side by side along the direction in which the plurality of nozzle openings 21 for ejecting the same color ink are arranged side by side. Hereinafter, this direction will be referred to as the side-by-side direction of the pressure generating chambers 12 or the first direction X. As shown in FIG. A direction perpendicular to the first direction X will be referred to as a second direction Y hereinafter.

Further, an ink supply path 14 and a communication path 15 are provided on one end side of the pressure generating chamber 12 in the longitudinal direction of the flow path forming substrate 10, that is, one end side of the second direction Y orthogonal to the first direction X. are partitioned by a plurality of partition walls 11 . On the outside of the communication path 15 (on the side opposite to the pressure generating chambers 12 in the second direction Y), there is a communicating portion that constitutes a part of the manifold 100 and serves as an ink chamber (liquid chamber) common to the pressure generating chambers 12. 13 are formed. That is, the flow path forming substrate 10 is provided with a liquid flow path including the pressure generating chamber 12 , the ink supply path 14 , the communication path 15 and the communication portion 13 .

A nozzle plate 20 having nozzle openings 21 communicating with the pressure generating chambers 12 is provided on one side of the flow path forming substrate 10, that is, the surface where the liquid flow paths such as the pressure generating chambers 12 open. or a heat-sealing film or the like. That is, nozzle openings 21 are arranged side by side in the first direction X in the nozzle plate 20 .

An elastic film 50 and an insulator film 55 formed on the elastic film 50 are laminated on the other surface side of the flow path forming substrate 10 . The liquid channels such as the pressure generating chambers 12 are formed by anisotropically etching one surface of the channel forming substrate 10, and the other surface of the liquid channels such as the pressure generating chambers 12 is formed by an elastic membrane. 50.

A piezoelectric actuator 300 (pressure generating means) having a first electrode 60 , a piezoelectric layer 70 and a second electrode 80 is formed on the insulator film 55 . Here, the piezoelectric actuator 300 refers to a portion including the first electrode 60 , the piezoelectric layer 70 and the second electrode 80 . Generally, one of the electrodes of the piezoelectric actuator 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12 . Here, a portion that is composed of either one of the patterned electrodes and the piezoelectric layer 70 and that undergoes piezoelectric strain when a voltage is applied to both electrodes is called a piezoelectric active portion. In this embodiment, the first electrode 60 is the common electrode of the piezoelectric actuator 300, and the second electrode 80 is the individual electrode of the piezoelectric actuator 300. However, there is no problem even if this is reversed for convenience of the drive circuit and wiring. In the above example, the elastic film 50, the insulator film 55, and the first electrode 60 act as a diaphragm, but the present invention is not limited to this. Instead, only the first electrode 60 may act as a diaphragm. Also, the piezoelectric actuator 300 itself may substantially serve as a diaphragm. However, when the first electrode 60 is provided directly on the flow path forming substrate 10, it is preferable to protect the first electrode 60 with an insulating protective film or the like so that the first electrode 60 and the ink are not electrically connected.

The piezoelectric layer 70 is made of an oxide piezoelectric material having a polarized structure formed on the first electrode 60, and can be made of, for example, a perovskite-type oxide represented by the general formula ABO ₃ , where A is lead. and B can include at least one of zirconium and titanium. Said B can further contain niobium, for example. Specifically, the piezoelectric layer 70 includes, for example, lead zirconate titanate (Pb(Zr, Ti)O ₃ : PZT), lead zirconate titanate niobate containing silicon (Pb(Zr, Ti, Nb ) O ₃ :PZTNS) and the like can be used.

The piezoelectric layer 70 is made of a lead-free piezoelectric material that does not contain lead, such as a composite oxide having a perovskite structure containing bismuth ferrate, bismuth ferrate manganate, and barium titanate or bismuth potassium titanate. may be

Further, each second electrode 80, which is an individual electrode of the piezoelectric actuator 300, is pulled out from the vicinity of the end on the side of the ink supply path 14 and extended onto the insulator film 55. For example, gold ( A lead electrode 90 made of Au) or the like is connected.

On the channel forming substrate 10 on which the piezoelectric actuator 300 is formed, that is, on the first electrode 60, the insulator film 55, and the lead electrode 90, there is a manifold portion 31 that constitutes at least a part of the manifold 100. A protective substrate 30 is bonded via an adhesive 35 . In this embodiment, the manifold portion 31 is formed so as to penetrate the protective substrate 30 in the thickness direction and extend across the width direction of the pressure generating chambers 12. , and constitutes a manifold 100 serving as a common ink chamber for the pressure generating chambers 12 . Alternatively, the communicating portion 13 of the flow path forming substrate 10 may be divided into a plurality of pressure generating chambers 12, and only the manifold portion 31 may be used as a manifold. Furthermore, for example, only the pressure generating chambers 12 are provided in the flow path forming substrate 10, and a member (for example, the elastic film 50, the insulating film 55, etc.) interposed between the flow path forming substrate 10 and the protective substrate 30 is a manifold. An ink supply path 14 communicating with each pressure generating chamber 12 may be provided.

The protective substrate 30 is provided with a piezoelectric actuator holding portion 32 having a space that does not hinder the movement of the piezoelectric actuator 300 in a region facing the piezoelectric actuator 300 . It should be noted that the piezoelectric actuator holding portion 32 only needs to have a space that does not hinder the movement of the piezoelectric actuator 300, and the space may or may not be sealed.

Further, the protective substrate 30 is provided with a through hole 33 penetrating the protective substrate 30 in the thickness direction. The vicinity of the end of the lead electrode 90 drawn from each piezoelectric actuator 300 is provided so as to be exposed inside the through hole 33 .

A driving circuit 95 functioning as a signal processing section is fixed on the protective substrate 30 . As the drive circuit 95, for example, a circuit board, a semiconductor integrated circuit (IC), or the like can be used. The drive circuit 95 and the lead electrode 90 are electrically connected via a connection wiring 96 made of a conductive wire such as a bonding wire inserted through the through hole 33 .

As the protective substrate 30, it is preferable to use a material having substantially the same coefficient of thermal expansion as the passage forming substrate 10, such as glass or ceramic material. It was formed using a (110) silicon single crystal substrate.

A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protection substrate 30 . Here, the sealing film 41 is made of a material having low rigidity and flexibility, such as a polyphenylene sulfide (PPS) film, and one surface of the manifold section 31 is sealed by this sealing film 41 . The fixed plate 42 is made of a hard material such as metal, such as stainless steel (SUS). Since the area of the fixing plate 42 facing the manifold 100 is an opening 43 that is completely removed in the thickness direction, one surface of the manifold 100 is sealed only with the flexible sealing film 41. It is

In the ink jet recording head II of this embodiment, ink is taken in from an ink inlet connected to an external ink supply means (not shown), and after filling the inside from the manifold 100 to the nozzle openings 21 with ink, the drive circuit According to the recording signal from 95, a voltage is applied between the first electrode 60 and the second electrode 80 corresponding to the pressure generating chamber 12, and the elastic film 50, the insulator film 55, the first electrode 60 and the piezoelectric body By bending and deforming the layer 70 , the pressure in each pressure generating chamber 12 is increased and ink droplets are ejected from the nozzle openings 21 .

In the present embodiment, the ink jet recording head II having the piezoelectric actuator 300 having the piezoelectric layer 70 that suppresses damage such as cracks even when repeatedly driven is used. A recording head II can be realized.

FIG. 5 is a block diagram showing the control configuration of the ink jet recording apparatus. Now, with reference to FIG. 5, control of the ink jet recording apparatus of this embodiment will be described. As shown in FIG. 5, the ink jet recording apparatus of this embodiment is roughly configured from a printer controller 111 and a print engine 112 . The printer controller 111 includes an external interface 113 (hereinafter referred to as an external I/F 113), a RAM 114 that temporarily stores various data, a ROM 115 that stores control programs and the like, and a control section 116 that includes a CPU and the like. , an oscillation circuit 117 that generates a clock signal, a drive signal generation circuit 119 that generates a drive signal to be supplied to the liquid jet head II, and dot pattern data (bitmap data) developed based on the drive signal and print data. ) and the like to the print engine 112 (hereinafter referred to as an internal I/F 120).

The external I/F 113 receives print data composed of, for example, character codes, graphic functions, image data, etc. from a host computer (not shown) or the like. Also, a busy signal (BUSY) and an acknowledge signal (ACK) are output to the host computer or the like through the external I/F 113 . The RAM 114 functions as a reception buffer 121, an intermediate buffer 122, an output buffer 123, and a work memory (not shown). The reception buffer 121 temporarily stores print data received by the external I/F 113, the intermediate buffer 122 stores intermediate code data converted by the control unit 116, and the output buffer 123 stores dot pattern data. . The dot pattern data is composed of print data obtained by decoding (translating) the gradation data.

The ROM 115 also stores font data, graphic functions, etc., in addition to control programs (control routines) for performing various data processing. The control unit 116 reads the print data in the reception buffer 121 and causes the intermediate buffer 122 to store the intermediate code data obtained by converting the print data. It also analyzes the intermediate code data read from the intermediate buffer 122, refers to font data and graphic functions stored in the ROM 115, and develops the intermediate code data into dot pattern data. Then, the control unit 116 causes the output buffer 123 to store the developed dot pattern data after performing necessary decoration processing.

Then, when dot pattern data corresponding to one line of the ink jet recording head II is obtained, this one line of dot pattern data is output to the piezoelectric actuator 300 through the internal I/F 120 . When dot pattern data for one line is output from the output buffer 123, the intermediate code data that has been developed is erased from the intermediate buffer 122, and the next intermediate code data is processed for development.

The print engine 112 includes an ink jet recording head II, a paper feeding mechanism 124 and a carriage mechanism 125 . The paper feed mechanism 124 is composed of a transport motor, transport rollers 8, etc., and sequentially feeds print storage media such as recording paper in conjunction with the recording operation of the ink jet recording head II. That is, the paper feed mechanism 124 relatively moves the print storage medium in the sub-scanning direction.

The carriage mechanism 125 is composed of a carriage shaft 5 on which the ink jet recording head II can be mounted, and a carriage driving section for running the carriage shaft 5 along the main scanning direction. The ink jet recording head II is moved in the main scanning direction. The carriage drive section is composed of the drive motor 6, the timing belt 7, and the like, as described above.

The ink jet recording head II has a large number of nozzle openings 21 along the sub-scanning direction, and ejects droplets from each nozzle opening 21 at timings defined by dot pattern data and the like. Electric signals such as drive signals (COM) and print data (SI), which will be described later, are supplied to the piezoelectric actuators 300 of the ink jet recording head II via external wiring (not shown). In the printer controller 111 and the print engine 112 configured as described above, a drive signal having a predetermined drive waveform output from the printer controller 111 and the drive signal generation circuit 119 is selectively input to the piezoelectric actuator 300 as a latch. 132 , a level shifter 133 , a drive circuit (not shown) having a switch 134 and the like serve as drive means for applying a predetermined drive signal to the piezoelectric actuator 300 .

The shift register 131, the latch 132, the level shifter 133, the switch 134, and the piezoelectric actuator 300 are provided for each nozzle opening 21 of the ink jet recording head II. , the level shifter 133 and the switch 134 generate drive pulses from the ejection drive signal and relaxation drive signal generated by the drive signal generation circuit 119 . Here, the drive pulse is the applied pulse that is actually applied to the piezoelectric actuator 300 .

In such an ink jet recording head II, print data (SI) forming dot pattern data is first serially transmitted from the output buffer 123 to the shift register 131 in synchronization with the clock signal (CK) from the oscillation circuit 117 . , are set sequentially. In this case, first, the most significant bit data in the print data of all the nozzle openings 21 is serially transmitted, and after the serial transmission of the most significant bit data is completed, the second most significant bit data is serially transmitted. . In the same manner, lower-order bit data are sequentially serially transmitted.

Then, when the print data of the bit for all nozzles is set in each shift register 131, the control unit 116 causes the latch signal (LAT) to be output to the latch 132 at a predetermined timing. This latch signal causes the latch 132 to latch the print data set in the shift register 131 . The print data (LATout) latched by this latch 132 is applied to a level shifter 133 which is a voltage amplifier. This level shifter 133 boosts the print data to a voltage value that can drive the switch 134, for example, several tens of volts when the print data is "1". Then, this boosted print data is applied to each switch 134, and each switch 134 is put into a connected state by the print data.

A drive signal (COM) generated by the drive signal generation circuit 119 is also applied to each switch 134, and when the switch 134 is selectively connected, the piezoelectric actuator 300 connected to this switch 134 is selected. A drive signal is applied to the terminal. As described above, in the illustrated ink jet recording head II, it is possible to control whether or not to apply the ejection drive signal to the piezoelectric actuator 300 according to the print data. For example, when the print data is "1", the switch 134 is connected by the latch signal (LAT), so that the driving signal (COMout) can be supplied to the piezoelectric element 18. COMout) causes the piezoelectric element 18 to be displaced (deformed). Moreover, since the switch 134 is in a non-connected state during the period when the print data is "0", the supply of the drive signal to the piezoelectric actuator 300 is cut off. It should be noted that each piezoelectric actuator 300 holds the previous potential during the period in which the print data is "0", so the previous displacement state is maintained.

Further, the ink jet recording apparatus I of the present embodiment is provided with a detection means 210 for detecting ejection failure of ink droplets from the nozzle openings 21 .

As the detection means 210, for example, an optical system sensor such as a scanner that detects discharge failures (missing dots) by printing a test pattern on the ink jet recording apparatus I and reading the print pattern as an image can be used. Further, the detection means 210, for example, charges ink by applying a voltage between an inspection region made of a liquid absorber and the nozzle plate 20 (nozzle opening 21), and ejects the charged ink as ink droplets. Thus, by outputting a potential signal representing a change in potential between the inspection area and the nozzle plate 20, a method of detecting an ejection failure based on the amplitude of this potential signal may be used. Further, the detection means 210 detects an excessive voltage (electromotive voltage) generated in the piezoelectric actuator 300 after driving the piezoelectric actuator 300, and detects the state of the vibration (residual vibration), for example, the period and amplitude of the residual vibration. It may be one that detects an ejection failure. Of course, the detection means is not limited to those described above, and conventionally known means can be used.

As the detection means 210, a system that can be performed almost simultaneously with printing is preferable, and it is particularly preferable to detect an excessive voltage generated in the piezoelectric actuator 300, observe residual vibration, and detect an ejection failure. This embodiment adopts this. It should be noted that the method disclosed in detail in Japanese Patent No. 3794431 may be used as a method for detecting and determining ejection failure due to residual vibration.

Further, the control unit 116 is provided with a switching unit 220 in addition to the printing control unit 201 for creating print data as described above. The switching unit 220 controls the printing control unit 201 to switch the printing operation to be performed by the printing control unit 201 between the normal mode and the ejection prohibition mode based on the detection result of the detection unit 210 .

Here, the normal mode is normal printing executed when the detecting means 210 does not detect an ejection failure (missing dots), and based on the print signal, the piezoelectric pressure corresponding to one pressure generating chamber 12 is detected. By driving the actuator 300 , printing is performed so that the ink droplets ejected from the nozzle openings 21 corresponding to one pressure generating chamber 12 fill the area of the recording sheet S for one dot.

On the other hand, the ejection prohibition mode is printing that is executed when the detection unit 210 detects an ejection failure (missing dot). Driving of the piezoelectric actuator 300 corresponding to the nozzle opening 21 is prohibited at all. Here, prohibiting the driving of the piezoelectric actuator 300 at all means that the nozzle openings 21 in which the ejection failure has occurred are not only driven for ejection based on print data, but also driven for flushing operation and for preventing ink thickening. The drive for the micro-vibration operation, in which micro-vibration is applied without causing ejection, is also completely prohibited, and is continued until a recovery operation such as a suction recovery operation is performed.

The ejection prohibition mode completely prohibits driving of the piezoelectric actuator 300 corresponding to the nozzle opening 21 in which the ejection failure occurs, thereby preventing the ejection failure from worsening, for example, from becoming unrecoverable. If the piezoelectric actuator 300 corresponding to the nozzle opening 21 in which the ejection failure occurs continues to be driven for the ejection operation or for the micro-vibration operation, the thickened ink present in the vicinity of the nozzle opening 21 is agitated and inside. If this continues for a long period of time, the thickened state may progress into the interior and may become unrecoverable, so this is to be prevented. When the ejection inhibit mode is executed, the piezoelectric actuator 300 corresponding to the nozzle opening 21 is not driven at all, so the thickened ink in the vicinity of the opening of the nozzle opening 21 stays as it is, and even after a long period of time, it thickens and becomes a film. It is possible to prevent the viscous from advancing inward, and maintain a state in which it is easy to recover in the next recovery operation.

In principle, printing is continued even in the ejection prohibition mode, but if the number of nozzle openings 21 in which defective ejection has been detected is extremely large, printing may be stopped and recovery processing may be performed immediately.

Further, when printing is continued in the ejection prohibition mode, driving of the piezoelectric actuator 300 corresponding to the nozzle opening 21 in which an ejection failure has been detected is prohibited, so printing is continued in the other nozzle openings 21 . It should be noted that prohibition of driving of the piezoelectric actuator 300 corresponding to the nozzle opening 21 in which ejection failure has been detected can be easily performed by cutting the drive signal to the piezoelectric actuator 300 . For example, switching to the connected state of the switch 134 corresponding to the piezoelectric actuator 300 for which an ejection failure has been detected may be prohibited.

Furthermore, when printing is continued in the ejection prohibition mode, complementary printing is executed in which printing is continued using print data for supplementing ejection from the nozzle opening 21 in which an ejection failure has been detected with ejection from another nozzle opening 21. good too.

Such complementary printing may be performed by using a conventionally known method, but it is necessary to completely cut off the drive data for the piezoelectric actuator 300 corresponding to the nozzle opening 21 in which the ejection failure has occurred.

A switching operation between printing in the normal mode and printing in the ejection inhibit mode will be described with reference to the flow chart of FIG.

After printing for a predetermined period of time in step S1, it is determined in step S2 whether or not the nozzle openings are performing normal ejection. If normal ejection is not performed from all nozzle openings and there is a nozzle opening with ejection failure (step S2, No), the ejection prohibition mode is set at step S3, and normal ejection is performed from all nozzle openings. If so (step S2, Yes), the process proceeds directly to step S4. In step S4, it is determined whether or not printing is finished. If not (step S4, No), the process returns to step S1 to continue printing. At this time, if the ejection prohibition mode is set in step S3, printing is continued in the ejection prohibition mode, and if the ejection prohibition mode is not set in step S3, printing is continued in the normal mode. be done. Then, if it is determined in step S4 that printing has ended (step S4, Yes), it is determined in step S5 whether or not all the nozzle openings are normal. S5, No), recovery processing is executed in step S6, and then the next printing is performed (step S7). In this case, even if a defective nozzle opening occurs during printing and printing is continued after that, printing is continued in the ejection prohibition mode after the occurrence of the defective ejection. Since the subsequent driving is prohibited at all, recovery can be reliably performed by the recovery processing in step S6. If all the nozzle openings are normal in step S5 (step S5, Yes), the process proceeds to the next printing (step S7).

In the embodiment described above, when an ejection failure is detected during printing, the piezoelectric actuator 300 corresponding to the ejection failure nozzle opening is completely prohibited from being driven and printing is continued. A defective nozzle opening can be reliably recovered by a recovery process after printing is completed without exacerbating ejection failure.

(Embodiment 2)
FIG. 7 shows a schematic configuration of a recording system comprising a host computer as a control device and a recording device connected thereto.

As shown in FIG. 7, the host computer 250 includes a host-side control section 260 and a storage section 270 .

The control unit 260 includes a CPU, a ROM, a RAM, other peripheral circuits, etc., centrally controls each unit of the host computer 250 , and includes a control command generation unit 261 . The storage unit 270 also includes a memory that stores various data in a nonvolatile manner, and stores at least an application program 271 and a device driver 272 .

The application program 271 generates information about recording data when the recording device 280 performs recording, and outputs the information to the device driver 272 .

Also, the device driver 272 is a program for controlling the recording device 280 . When information about recording data is input from the application program 271 , the device driver 272 generates a control command and outputs it to the recording device 280 . The recording device 280 performs recording based on the control commands.

The recording device 280 includes an inkjet head (recording head) capable of color printing and a recording unit having a transport mechanism for transporting the set label paper. or the structure described in the first embodiment except that the switching means 220 is not provided.

The recording device 280 includes a printer-side control unit 290 and an ink jet recording head II similar to that of the first embodiment.

The control unit 290 has a CPU, ROM, RAM, etc., and centrally controls each unit of the recording device 280 . A control unit 290 on the printer side includes print control means 291 that, when receiving a control command from the host computer 250, interprets the control command and causes the inkjet recording head II to perform recording.

In this embodiment, the host-side controller 260 comprises a detection means 210A and a switching means 220A. Since the detection means 210 and the switching means 220 are basically the same as those in the first embodiment, they will be briefly described.

The detection means 210A is for detecting ejection failures of ink droplets from the nozzle openings 21. Specifically, after the piezoelectric actuator 300 is driven, the detection means 210A detects excessive voltage (electromotive voltage) generated in the piezoelectric actuator 300, An ejection failure is detected from the state of the vibration (residual vibration), for example, the period or amplitude of the residual vibration.

The switching means 220A switches the control command generated by the control command generating section 261 between the normal mode control command and the ejection prohibition mode control command based on the detection result of the detecting means 210A.

Here, the normal mode is normal printing that is executed when the detecting means 210A does not detect an ejection failure (missing dots). By driving the actuator 300 , a control command is generated to perform printing so that ink droplets ejected from the nozzle openings 21 corresponding to one pressure generating chamber 12 fill a one-dot area of the recording sheet S.

On the other hand, the ejection prohibition mode is printing that is executed when the detection unit 210A detects an ejection failure (missing dot). Driving of the piezoelectric actuator 300 corresponding to the nozzle opening 21 is prohibited at all. Here, prohibiting the driving of the piezoelectric actuator 300 at all means that the nozzle openings 21 in which the ejection failure has occurred are not only driven for ejection based on print data, but also driven for flushing operation and for preventing ink thickening. The drive for the micro-vibration operation, in which micro-vibration is applied without causing ejection, is also completely prohibited, and is continued until a recovery operation such as a suction recovery operation is performed.

In principle, printing is continued even in the ejection prohibition mode, but if the number of nozzle openings 21 in which defective ejection has been detected is extremely large, printing may be stopped and recovery processing may be performed immediately.

The control command for continuing printing in the ejection prohibition mode prohibits driving of the piezoelectric actuator 300 corresponding to the nozzle opening 21 in which an ejection failure has been detected, and continues printing in the nozzle openings 21 other than this. It is a control command.

In this embodiment, the host computer 250 detects the nozzle opening 21 with the ejection failure, and if the nozzle opening 21 with the ejection failure is detected, the control command for the ejection prohibition mode is transmitted to the printing apparatus 280. It is possible to prevent an unrecoverable state without exacerbating the ejection failure.

Further, as described above, in order to equip the control unit 260 of the host computer 250 with the detection means 210A and the switching means 220A as described above, a program for causing the control unit 260 to function as the detection means 210A and the switching means 220A is executed. do it.

Even in the embodiment described above, when an ejection failure is detected during printing, the piezoelectric actuator 300 corresponding to the ejection failure nozzle opening is completely prohibited from being driven and printing is continued. A defective nozzle opening can be reliably recovered by a recovery process after printing is completed without exacerbating ejection failure.

(Other embodiments)
Although one embodiment of the present invention has been described above, the basic configuration of the present invention is not limited to the one described above.

In Embodiment 1 described above, an example in which one nozzle opening 21 is provided for one pressure generating chamber 12 is shown, but the present invention is not limited to this, and two or more nozzle openings are provided for one pressure generating chamber 12. nozzle openings may be provided. Even in the case where there are a plurality of nozzle openings communicating with one pressure generating chamber as described above, the plurality of nozzle openings communicating with one pressure generating chamber are regarded as one nozzle opening 21, and the plurality of nozzle openings 21 A nozzle group may be constructed.

Furthermore, in the above-described first embodiment, the piezoelectric actuator 300 having the thin-film piezoelectric layer 70 is used as the pressure generating means for generating a pressure change in the pressure generating chamber 12. However, the present invention is not particularly limited to this. For example, a piezoelectric actuator having a thick film type piezoelectric layer formed by a method such as attaching a green sheet, or a longitudinal vibration type piezoelectric actuator that alternately laminates a piezoelectric material and an electrode forming material and expands and contracts in the axial direction. Actuators and the like can be used. As the pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are ejected from the nozzle opening by bubbles generated by the heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode. Alternatively, a so-called electrostatic actuator that deforms a diaphragm by electrostatic force to eject liquid droplets from a nozzle opening can be used.

In the above-described example, the ink jet type recording apparatus I has a configuration in which the ink cartridge 2, which is liquid storage means, is mounted on the carriage 3. However, it is not limited to this. may be fixed to the apparatus main body 4, and the storage means and the ink jet recording head II may be connected via a supply pipe such as a tube. Also, the liquid storage means may not be mounted on the ink jet recording apparatus.

In the above embodiments, an ink jet recording head is used as an example of a liquid ejecting head, and an ink jet recording apparatus is used as an example of a liquid ejecting apparatus. However, the present invention widely includes liquid ejecting heads. The present invention is intended for liquid ejecting apparatuses in general, and can of course be applied to a liquid ejecting apparatus having a liquid ejecting head that ejects a liquid other than ink. Other liquid jet heads include, for example, various recording heads used in image recording apparatuses such as printers, coloring material jet heads used in manufacturing color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). and an electrode material ejection head used for electrode formation, and a bioorganic matter ejection head used for biochip production, and the liquid ejection apparatus having such a liquid ejection head can be applied.

I inkjet recording apparatus (liquid ejecting apparatus) II inkjet recording head (liquid ejecting head) 10 flow path forming substrate 12 pressure generating chamber 13 communicating section 14 ink supply path 15 communicating path 20 nozzle plate 21 Nozzle opening 30 Protection substrate 31 Manifold part 32 Piezoelectric actuator holding part 40 Compliance substrate 50 Elastic film 55 Insulator film 60 First electrode 70 Piezoelectric layer 80 Second electrode 90 Lead electrode 100 Manifold 116 Control Unit (Control Means) 210, 210A Detection Means 220, 220A Switching Means 250 Host Computer 280 Recording Device 290 Control Unit 300 Piezoelectric Actuator

Claims (5)

a liquid ejecting head comprising a plurality of nozzle openings for ejecting liquid; and pressure generating means for generating pressure changes in pressure generating chambers respectively communicating with the nozzle openings;
detection means for detecting ejection failure of liquid droplets of the liquid ejecting head for each of the nozzle openings;
and a control means for controlling the pressure generating means,
Based on print data, the pressure generating means corresponding to the nozzle openings for ejecting droplets is driven by an ejection operation, and the pressure generating means corresponding to the nozzle openings not for ejecting droplets is ejected to prevent thickening. A liquid ejecting apparatus in which the control means controls the pressure generating means so as to drive the pressure generating means by a micro-vibration operation that gives a micro-vibration without causing a vibration,
When the ejection failure is detected during a printing operation, the control means completely prohibits driving for the ejection operation and the micro-vibration operation by the pressure generation means corresponding to the nozzle opening in which the ejection failure is detected, controlling the pressure generating means in an ejection prohibition mode in which the printing operation is continued using nozzle openings other than the nozzle opening in which the ejection failure has been detected;
The liquid ejecting apparatus, wherein the control means continues to control the pressure generating means in the ejection prohibition mode until it is determined that the printing operation has ended. The control means controls, in the ejection prohibition mode, the pressure generation means to prohibit driving for the flushing operation, the ejection operation, and the micro-vibration operation by the pressure generation means corresponding to the nozzle opening in which the ejection failure has been detected. 2. The liquid ejecting apparatus according to claim 1, further comprising: controlling means. 3. The liquid ejecting apparatus according to claim 1, wherein the control unit performs recovery processing after determining that the printing operation has ended. When continuing printing using nozzle openings other than the nozzle openings for which the ejection failure has been detected in the ejection prohibition mode, the control means prevents ejection from the nozzle openings for which the ejection failure has been detected from other nozzle openings. 4. The liquid ejecting apparatus according to claim 1, wherein printing is continued with print data complemented by ejection. 5. The detecting means, after driving the pressure generating means, detects an excessive voltage generated in the pressure generating means, and detects an ejection failure from the state of the vibration. 1. The liquid injection device according to item 1.

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