JP2009119759A - Liquid jet device, and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet device which exhibits stable jetting characteristics irrespective of the number of nozzles simultaneously jetting inks, and its control method. <P>SOLUTION: The liquid jet device compares the number of nozzles simultaneously jetting the ink with a predetermined threshold. When the number of nozzles simultaneously jetting the inks is lower than the threshold, the device changes the polarity of either of a pair of FFCs so as to make the polarities of conduction patterns 55 facing each other between the first FFC 10a and the second FFC 10b differ from each other. When the number of nozzles simultaneously jetting the inks is equal to or larger than the threshold, the device changes the polarity of the conduction pattern of one of the pair of the FFCs so as to make both conduction patterns facing each other between the FFCs have the same polarities. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus including a liquid ejecting head that ejects liquid from a nozzle by the operation of an ejecting drive source, and a control method therefor, and in particular, a drive signal from a drive signal generating unit is ejected from the liquid ejecting head. The present invention relates to a structure of a wiring member for transmitting to a source side.

  The liquid ejecting apparatus is an apparatus that includes a liquid ejecting head capable of ejecting (discharging) liquid and ejecting various liquids from the liquid ejecting head. As a typical example of this liquid ejecting apparatus, for example, an image recording apparatus such as an ink jet printer that performs recording by ejecting and landing liquid ink on recording paper or the like as a landing target (recording medium). Can be mentioned. In recent years, in addition to the image recording apparatus, for example, in a display manufacturing apparatus such as a liquid crystal display and an organic EL (Electro Luminescence) display, various liquid materials such as coloring materials and electrodes are used as pixel forming regions. A liquid ejecting apparatus is suitably used as a means for ejecting the electrode or the electrode forming region.

  Taking the above-described ink jet printer (hereinafter simply abbreviated as a printer) as an example, the printer includes an ink jet recording head (a type of liquid ejecting head; hereinafter abbreviated as a recording head) that ejects ink. The recording head is supplied with a drive signal from a drive signal generation circuit (drive signal generation circuit) on the printer controller side through a flexible flat cable (a type of wiring member; hereinafter abbreviated as FFC) to eject ink. It is configured as follows.

  The FFC is a band-like flexible wiring member in which conductive patterns, which are a large number of conductive lines, are arranged in the band width direction, and is configured by molding a conductive pattern into a synthetic resin (for example, Patent Documents). 1). In general, an FFC having a length about twice the moving span of the recording head is used. The conductive pattern of the FFC is derived from drive signal lines (positive electrode side conductive pattern (COM), negative electrode conductive pattern (GND)), temperature detection signal line, and other logic signal lines of the piezoelectric vibrator which is an ejection drive source. Become. In recent years, the number of FFC conductive patterns is also increasing in order to cope with an increase in the number of nozzles and diversification of ink types. For this reason, the increase in the conductive pattern is accommodated by laminating a plurality of FFCs.

Japanese Patent Laid-Open No. 11-188865

  However, for example, when performing so-called solid printing that fills a wide area of recording paper with dots without gaps, a large number of piezoelectric vibrators are driven simultaneously to eject ink from each nozzle. As a result of the increase, a voltage drop occurs in the drive signal for driving the piezoelectric vibrator of the recording head, and as a result, there is a possibility of adversely affecting the ink ejection characteristics. That is, depending on the number of nozzles that eject ink at the same time, there is a possibility that the weight of the ink and the flying speed vary and the image quality of the recorded image becomes unstable.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a liquid ejecting apparatus capable of obtaining stable ejecting characteristics regardless of the number of nozzles ejecting ink simultaneously, and a control method thereof. There is to do.

The present invention has been proposed to achieve the above object, and a liquid ejecting head that ejects liquid from a nozzle by the operation of an ejection drive source and a drive that generates a drive signal for operating the ejection drive source. A liquid ejecting apparatus comprising: a signal generating unit; and a wiring member for transmitting a driving signal from the driving signal generating unit to the ejection driving source side of the liquid ejecting head,
The wiring member has a strip-like shape in which first conductive patterns connected to the positive electrode side of the ejection driving source and second conductive patterns connected to the negative electrode side of the ejection driving source are alternately arranged in the band width direction. Laminated with multiple cables in pairs,
Switching means for switching the polarity of the conductive pattern of either the first cable or the second cable in a pair;
Control means for controlling the switching means,
The control means compares the number of nozzles that simultaneously eject liquid with a predetermined threshold value, and faces the first cable and the second cable when the number of simultaneous ejection nozzles is less than the threshold value. The switching means is controlled so that the polarities of the conductive patterns are different from each other. On the other hand, when the number of simultaneous injection nozzles is equal to or greater than the threshold value, the opposite conductive properties between the first cable and the second cable. The switching means is controlled so that the polarities of the patterns are the same.

According to another aspect of the present invention, there is provided a liquid ejecting head that ejects liquid from a nozzle by the operation of an ejection drive source, a drive signal generation unit that generates a drive signal for operating the ejection drive source, and a drive signal generation unit A wiring member for transmitting a drive signal to the ejection drive source side of the liquid ejection head, and
The wiring member has a strip-like shape in which first conductive patterns connected to the positive electrode side of the ejection driving source and second conductive patterns connected to the negative electrode side of the ejection driving source are alternately arranged in the band width direction. A control method for a liquid ejecting apparatus in which a plurality of cables are paired and laminated,
Compare the number of nozzles that simultaneously eject liquid with a predetermined threshold,
When the number of simultaneous injection nozzles is less than the threshold value, the first cable or the first cable paired so that the conductive patterns facing each other between the first cable and the second cable have different polarities. Switch the polarity of one of the conductive patterns of the second cable,
When the number of simultaneous injection nozzles is equal to or greater than the threshold, the polarity of the one cable is switched so that the polarities of the conductive patterns facing each other between the first cable and the second cable are the same. It is characterized by.

  According to the above configuration, when the number of simultaneous injection nozzles is less than the threshold value, the conductive patterns facing each other between the first cable and the second cable are paired so that the polarities are different from each other. When the polarity of the conductive pattern of either the first cable or the second cable is switched and the number of simultaneous injection nozzles is equal to or greater than the threshold value, the conductive surfaces facing each other between the first cable and the second cable Since the polarity of one cable is switched so that the polarities of the patterns are the same, it is possible to obtain stable ejection characteristics by suppressing fluctuations in the amount of liquid and flight speed regardless of the number of nozzles that eject liquid simultaneously. Is possible.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following, an ink jet recording apparatus (ink jet printer) will be described as an example of the liquid ejecting apparatus of the invention.

The printer 1 includes a recording head 2 that is a type of liquid ejecting head and a carriage 4 on which an ink cartridge 3 (a type of liquid storage member) is detachably attached, and a platen 5 that is disposed below the recording head 2. A carriage moving mechanism 7 that moves the recording head 2 (carriage 4) in the paper width direction of the recording paper 6 (a kind of landing target), that is, the main scanning direction, and a sub-scanning direction that is a direction orthogonal to the head moving direction. A paper feed mechanism 8 for conveying the recording paper 6 and a printer controller 9 for controlling each part are schematically configured. Drive signals and various control signals from the printer controller 9 are transmitted to the recording head 2 through a flexible flat cable (FFC) 10 (corresponding to a wiring member in the present invention). Details of the FFC 10 will be described later.
The ink cartridge 3 may be a type that is mounted on the carriage 4 or a type that is mounted on the housing side of the printer 1 and is supplied to the recording head 2 via an ink supply tube.

  The carriage 4 is attached in a state of being pivotally supported by a guide rod 11 installed in the main scanning direction, and is configured to move in the main scanning direction along the guide rod 11 by the operation of the carriage moving mechanism 7. ing. The position of the carriage 4 in the main scanning direction is detected by the linear encoder 12, and a detection signal is transmitted as position information to the control unit 48 (see FIG. 3) of the printer controller 9. Thus, the control unit 48 can control the recording operation (jetting operation) and the like by the recording head 2 while recognizing the scanning position of the carriage 4 (recording head 2) based on the position information from the linear encoder 12. .

  FIG. 2 is a partial cross-sectional view illustrating the configuration of the recording head 2. The recording head 2 includes a case 17, a vibrator unit 18 housed in the case 17, a flow path unit 19 joined to the bottom surface (tip surface) of the case 17, and the like. The case 17 is made of, for example, an epoxy-based resin, and a housing empty portion 20 for housing the vibrator unit 18 is formed therein. The vibrator unit 18 includes a piezoelectric vibrator 21 that functions as a kind of ejection drive source, a fixed plate 22 to which the piezoelectric vibrator 21 is joined, and a film cable 23 for supplying a drive signal and the like to the piezoelectric vibrator 21. And.

  The piezoelectric vibrator 21 is a laminated type produced by cutting a piezoelectric plate in which piezoelectric layers and electrode layers are alternately laminated into a comb-like shape, and is capable of expanding and contracting in a direction perpendicular to the laminating direction. This is a piezoelectric vibrator. The film cable 23 is composed of a film-like wiring member such as TCP (tape carrier package). In the film cable 23, a drive IC 24 for selectively supplying a drive signal to the piezoelectric vibrator 21 is mounted in a region facing the fixed plate 22.

  The film cable 23 is configured by forming a conductor pattern with copper foil on the surface of an insulating film such as polyimide or polyester and covering portions other than the wiring terminals with a resist. The front end side of the film cable 23 is electrically connected to the external electrode 15 (see FIG. 4) of the piezoelectric element 21. In addition, the rear end side of the film cable 23 is electrically connected to a relay board 25 that relays a drive signal and the like from the FFC 10 side. In addition to a connector (not shown) for connecting the FFC 10, a switching circuit 53 (see FIG. 3) described later is mounted on the relay board 25.

  As shown in FIG. 4, the individual wiring terminals 23 a of the film cable 23 are arranged on the leading end side of the film cable 23 so as to correspond to the individual external electrodes 15 a (positive electrodes) of the piezoelectric vibrator 21. On the other hand, the individual wiring terminals 23a are connected to the common external electrode 15b (negative electrode) of the piezoelectric vibrator 21 on both sides in the arrangement direction of the individual wiring terminals 23a and closer to the rear end of the film cable 23 than the individual wiring terminals 23b. A common wiring terminal 23b is provided.

  In the piezoelectric vibrator 21, the external electrodes 15 are formed on the wiring connection surface excluding the side surfaces, the front end surface portion, the rear end surface portion, and the fixed plate joint surface by vapor deposition or sputtering using a conductive material. The individual external electrode 15a is an external electrode formed in series on the front end surface portion and the wiring connection surface of each piezoelectric vibrator 21, and in the portion on the wiring connection surface side, from the front end side of the piezoelectric vibrator 21 to the vicinity of the rear end. It is formed continuously. A portion of each individual external electrode 15 a located near the rear end of the piezoelectric vibrator 21 is a portion joined to the individual wiring terminal 23 a of the film cable 23. On the other hand, the common external electrode 15b is an external electrode formed in series on the wiring connection surface, the rear end surface portion, and the fixed plate joint surface of the piezoelectric vibrator 21, and the piezoelectric vibration is greater on the wiring connection surface than the individual external electrode 15a. It is continuously formed from the position away from the rear end side of the child 21 toward the rear end surface portion.

  The flow path unit 19 is configured by joining a nozzle plate 28 to one surface of the flow path forming substrate 27 and a diaphragm 29 to the other surface of the flow path forming substrate 27. The flow path unit 19 is provided with a reservoir 31, an ink supply port 32, a pressure chamber 33, a nozzle communication port 34, and a nozzle 35. A series of ink flow paths from the reservoir 31 to the nozzle 35 via the ink supply port 32, the pressure chamber 33, and the nozzle communication port 34 are formed corresponding to each nozzle 35.

  The nozzle plate 28 is a thin metal plate in which a plurality of nozzles 35 are formed in a row at a pitch (for example, 180 dpi) corresponding to the dot formation density. In the present embodiment, the nozzle plate 28 is made of a stainless steel plate material, and a plurality of nozzle 35 rows (nozzle rows, a kind of nozzle group) are provided. One nozzle row is composed of, for example, 180 nozzles 35. The recording head 2 in the present embodiment has a total of four colors of inks of different colors (a kind of liquid in the present invention), for example, cyan (C), magenta (M), yellow (Y), and black (K). A total of four nozzle rows are formed on the nozzle plate 28 corresponding to the inks. Therefore, the recording head 2 in the present embodiment includes a total of four transducer units 18 corresponding to the respective colors.

  The diaphragm 29 has a double structure in which an elastic film 38 is laminated on the surface of the support plate 37. In the present embodiment, the vibration plate 29 is manufactured using a composite plate material in which a stainless plate, which is a kind of metal plate, is used as the support plate 37 and a resin film is laminated on the surface of the support plate 37 as an elastic film 38. The diaphragm 29 is provided with a diaphragm portion 39 that changes the volume of the pressure chamber 33. The diaphragm 29 is provided with a compliance portion 40 that seals a part of the reservoir 31.

  The diaphragm 39 is produced by partially removing the support plate 37 by etching or the like. That is, the diaphragm portion 39 is formed by removing the surrounding support plate 37 by an etching process while leaving the portion to which the tip surface of the piezoelectric vibrator 21 is connected as the island portion 41, so that only the elastic film 38 is obtained. It consists of The compliance unit 40 is produced by removing the support plate 37 in the region facing the opening surface of the reservoir 31 by etching or the like in the same manner as the diaphragm unit 39, and the pressure fluctuation of the liquid stored in the reservoir 31 is reduced. Functions as a damper to absorb.

  In the recording head 2, when the drive signal COM is supplied from the drive signal generation circuit 50 to the piezoelectric vibrator 21 through the FFC 10, the relay substrate 25, and the film cable 23, the piezoelectric vibrator 21 expands and contracts in the longitudinal direction of the element. As a result, the island portion 41 is displaced in the direction approaching or separating from the pressure chamber 33. As a result, the volume of the pressure chamber 33 changes, and the pressure in the ink in the pressure chamber 33 varies. Ink is ejected from the nozzles 35 by this pressure fluctuation.

  FIG. 3 is a block diagram illustrating an electrical configuration of the printer 1. The printer 1 is schematically composed of a printer controller 9 and a print engine 44. The printer controller 9 stores an external interface (external I / F) 45 that receives print data from an external device such as a host computer, a RAM 46 that stores various data, a control program for various controls, and the like. The ROM 47, a control unit 48 (corresponding to the control means in the present invention) that performs overall control of each unit in accordance with a control program stored in the ROM 47, an oscillation circuit 49 that generates a clock signal, and the recording head 2 A driving signal generating circuit 50 (a kind of driving signal generating means in the present invention) for generating a driving signal to be output, and ejection data, a driving signal, and the like obtained by developing print data for each dot are output to the recording head 2. And an internal interface (internal I / F) 51 for this purpose. The printer controller 9 is provided with a switching circuit 52 for switching the polarity of the conductive pattern of the FFC 10 (first FFC 10a). On the other hand, the print engine 44 includes the recording head 2, the carriage moving mechanism 7, the paper feeding mechanism 8, and the linear encoder 12.

  The control unit 48 develops the print data transmitted from the external device into ejection data corresponding to the dot pattern and transmits it to the recording head 2. In this case, the control unit 48 reads the print data in the reception buffer, converts it into intermediate code data, and stores this intermediate code data in the intermediate buffer. Then, the control unit 48 analyzes the intermediate code data read from the intermediate buffer, and expands the intermediate code data into dot-by-dot ejection data (dot pattern data) with reference to font data, graphic functions, and the like in the ROM 47. The developed ejection data is temporarily stored in the output buffer. When ejection data for one line corresponding to one main scan is obtained, the ejection data for one line is stored in the recording head 2 through the internal I / F 51. Serial transmission. When ejection data for one line is transmitted from the output buffer, the contents of the intermediate buffer are erased, and conversion to the next intermediate code data is performed. The recording head 2 ejects ink droplets based on the received ejection data.

The drive signal generation circuit 50 generates a drive signal COM having a predetermined waveform.
For example, the drive signal COM includes a drive pulse DP as shown in FIG. The drive pulse DP includes an expansion element P1 that expands the pressure chamber 33 from the reference volume, a hold element P2 that maintains the pressure chamber 33 at the expansion volume for a short time, and a contraction element that contracts the pressure chamber 33 from the expansion volume to the reference volume. P3. In this embodiment, since the piezoelectric vibrator 21 in the longitudinal vibration mode is used as described above, the expansion element P1 increases the potential with a predetermined gradient that does not cause ink droplets to be ejected from the reference potential Vb to the maximum potential Vh. It becomes a waveform element. The hold element P2 is a constant waveform element at the maximum potential Vh, and the contraction element P3 is a waveform element that lowers the potential from the maximum potential Vh to the reference potential Vb with a steeper slope than the expansion element P1.

  When such a driving pulse DP is supplied, the recording head 2 operates as follows to eject ink from the nozzles. That is, the supply of the expansion element P1 causes the piezoelectric vibrator 21 to contract in the element longitudinal direction, and the pressure chamber 33 expands. The expansion of the pressure chamber 33 lowers the ink pressure, and ink is supplied from the reservoir 31 into the pressure chamber 33 and the free surface (meniscus) of the ink exposed to the nozzle 35 is drawn to the pressure chamber side. Next, the hold element P2 is supplied, and the meniscus freely vibrates over the supply period. Thereafter, the contraction element P3 is supplied at the timing when the meniscus is displaced from the pressure chamber side to the ejection side (the side opposite to the pressure chamber 33), and the piezoelectric vibrator 21 rapidly expands in the longitudinal direction of the element. As a result, the pressure chamber 33 is rapidly contracted to increase the ink pressure, and ink is ejected from the nozzle 35.

Next, the FFC 10 will be described.
6A and 6B are diagrams for explaining the configuration of the FFC 10. FIG. 6A is a perspective view of the FFC 10, and FIG. 6B is a cross-sectional view taken along line AA in FIG. The FFC 10 in this embodiment is a strip-like flexible wiring member in which conductive patterns 55, which are a large number of conductive lines, are arranged in the band width direction. The conductive pattern 55 is molded on a synthetic resin covering material 56. Configured. The conductive pattern 55 is formed by cutting a thin plate material made of, for example, a copper alloy into a strip shape. The FFC 10 in this embodiment has a structure in which a first FFC 10a (corresponding to a first cable in the present invention) and a second FFC 10b (corresponding to a second cable in the present invention) are stacked in pairs. . Further, connection portions 57 a and 57 b connected to the connectors are respectively provided at both ends of each FFC 10. One connection portion 75 a is connected to the connector of the printer controller 9, and the other connection portion 57 b is connected to the recording head 2. The relay board 25 is connected to the connector.

  The FFC 10 is configured to transmit the drive signal COM generated by the drive signal generation circuit 50, the injection data, the temperature detection signal, and other control logic signals. Since the drive signal COM is generated for each transducer unit 18, a plurality of sets of conductive patterns 55 for the drive signal COM are provided corresponding to the number of transducer units 18. A plurality of conductive patterns 55 for the drive signal COM can be assigned to one drive signal COM as a set, for example, a total of four in the present embodiment. The breakdown is the first conductive pattern 55a (COM) connected to the positive side of the piezoelectric vibrator 21 and the printer controller 9, and the second conductive pattern connected to the negative side of the piezoelectric vibrator 21 and the printer controller 9. 55b (GND) is two each. Therefore, since the recording head 2 in this embodiment includes a total of four transducer units 18, the drive signal conductive patterns 55 assigned to the FFC 10 are 16 in total. In each FFC 10a, 10b, the first conductive pattern 55a and the second conductive pattern 55b are alternately arranged in the band width direction. Of course, the number of conductive patterns assigned to one drive signal COM is not limited to that illustrated.

  By the way, in the printer 1 having the above-described configuration, for example, when performing so-called solid printing in which a relatively wide range of the recording paper 6 is filled with no gaps, a large number of piezoelectric vibrators 21 are driven at the same time and ink is supplied from each nozzle 35. Conventionally, in this case (for example, when jetting simultaneously from more than half of all nozzles: high DUTY), the voltage drop increases as the load increases. In this case, as shown in FIG. 5A, with respect to the drive voltage Vh of the drive pulse DP of the drive signal COM, than when the number of simultaneous injection nozzles is small (for example, less than half of the total number of nozzles: low DUTY). Also decreases (Vh ′ <Vh). As a result, the volume fluctuation amount of the pressure chamber 33 is reduced, so that not only the amount (weight / volume) of ejected ink is reduced, but also the pulse width Pw of the hold element P2 in the drive pulse DP is widened ( Pw ′> Pw), and thus the pressure chamber 33 may be expanded and then rapidly contracted to eject the ink from the optimum value. As a result, the flying speed of the ink is lowered, the flying direction is bent, and landing deviation on the recording paper 6 may occur.

  For this reason, in the printer 1 according to the present invention, the mutual inductance is intentionally generated by changing the arrangement of the conductive patterns 55 in the FFC 10 according to the number of nozzles that simultaneously eject ink (the number of simultaneous ejection nozzles). Thereby, the voltage drop of the drive pulse DP is suppressed. Hereinafter, this point will be described.

As shown in FIG. 3, the printer 1 includes switching means for switching the polarity of one of the conductive patterns 55 (the conductive pattern for the drive signal COM) of the first FFC 10 a or the second FFC 10 b that is paired with the FFC 10. Switching circuits (SW) 52 and 53 are provided on the printer controller 9 side and the recording head 2 side, respectively.
7A and 7B are schematic diagrams for explaining the polarity switching control by the switching circuits 52 and 53. FIG. 7A is a switching state at the time of the low DUTY (first pattern), and FIG. 7B is a switching state at the time of the high DUTY. (Second pattern) is shown. FIGS. 8A and 8B are diagrams showing the arrangement of the drive signal COM conductive pattern 55 in the FFC 10. FIG. 8A is a state at the time of low DUTY (first pattern), and FIG. 8B is a state at the time of high DUTY (first). 2 patterns).

  Switching of these switching circuits 52 and 53 is controlled by the control unit 48. In the present embodiment, the control unit 48 switches the polarity of the conductive pattern for the drive signal of the first FFC 10a. It is configured. That is, the first switching circuit 52 is disposed at the end of the first FFC 10a on the printer controller side, and the second switching circuit 53 is disposed at the end of the first FFC 10a on the recording head side. In the printer 1, a threshold value for the number of simultaneous ejection nozzles is set in advance in order to define the timing of switching control of the switching circuits 52 and 53. This threshold value can be arbitrarily determined according to the specifications of the head. For example, the number of simultaneous ejection nozzles corresponding to the upper limit of the allowable range for the change in the flying speed and weight of the ink due to the voltage drop of the drive signal COM is determined. Is set. In the present embodiment, this threshold value is set to half of the total number of nozzles of the recording head 2.

  Then, the control unit 48 functions as a control unit in the present invention, compares the number of nozzles that simultaneously eject ink with the above threshold value, and when the number of simultaneous ejection nozzles is less than the threshold value, FIG. 7A and FIG. As shown in FIG. 8A, the switching circuits 52 and 53 are switched and controlled so that the polarities of the conductive patterns facing each other between the first FFC 10a and the second FFC 10b are different from each other (first pattern). In the first pattern, as shown in FIG. 8A, the first FFC 10a and the second FFC 10a are in a state where the directions of the magnetic fields in the conductive pattern for one drive signal COM are totally opposite to each other. The induced electromotive force is canceled with the FFC 10b. As a result, the drive signal COM can be stably transmitted to the recording head 2 while suppressing waveform distortion.

  On the other hand, when the number of simultaneous injection nozzles is equal to or greater than the threshold value, the control unit 48 switches the switching circuit 52 so that the polarities of the conductive patterns facing each other between the first FFC 10a and the second FFC 10b are the same. , 53 are controlled to be switched (second pattern). In this second pattern, as shown in FIG. 8B, the polarities of the conductive patterns facing each other between the first FFC 10a and the second FFC 10b are the same, and the direction of the magnetic field is aligned. An induced electromotive force is generated between the first FFC 10a and the second FFC 10b. That is, the mutual inductance is intentionally generated by changing the arrangement of the conductive patterns. Accordingly, as shown in FIG. 5B, the drive voltage of the drive pulse DP of the drive signal COM can be increased (Vh ″> Vh ′). For this reason, a large number of piezoelectric vibrators 21 are driven simultaneously. In addition, it is possible to prevent fluctuations in the amount of ejected ink by suppressing the voltage drop caused by the above, and to suppress fluctuations in the pulse width Pw of the hold element P2 by suppressing the voltage drop in the driving voltage of the driving pulse DP. Therefore, it is possible to prevent a variation in the timing of ejecting the ink and suppress a decrease in the flying speed of the ink.

  Thus, by changing the arrangement of the conductive pattern of the FFC 10 according to the number of nozzles that simultaneously eject ink, it is possible to prevent fluctuations in the amount of ink ejected and the flying speed regardless of the number of simultaneous ejection nozzles. it can. As a result, it is possible to reduce the deterioration of the image quality of the image printed on the recording paper 6.

  By the way, the present invention is not limited to the above-described embodiment, and various modifications can be made based on the description of the scope of claims.

  For example, in the above-described embodiment, the FFC 10 in which a total of two FFCs, ie, the first FFC 10a and the second FFC 10b are stacked has been illustrated. However, the present invention is not limited to this. The present invention can also be applied when the FFC 10 is configured by stacking four or more FFCs.

  In the above embodiment, a set of switching circuits 52 and 53 is provided to switch the polarity of the entire conductive pattern of the first FFC 10a. However, the present invention is not limited to this. For example, the first FFC 10a is provided with a switching circuit corresponding to each drive signal COM of each transducer unit 18 (or nozzle row or liquid type), and the polarity of the conductive pattern corresponding to each transducer unit 18 is set. It is good also as a structure to switch. In this case, it is desirable to set the threshold value to half of all the nozzles corresponding to one transducer unit 18 (the number of nozzles constituting one nozzle row). As a result, more appropriate switching control can be performed according to the driving state of each transducer unit 18 (or nozzle row or liquid type), and as a result, the amount of ejected ink and the variation in the flying speed can be further reduced. It can be effectively prevented.

  In the above embodiment, the so-called longitudinal vibration mode piezoelectric vibrator 21 is exemplified as the ejection drive source of the present invention. However, the present invention is not limited to this. For example, it may be provided for each pressure chamber like a so-called flexural vibration mode piezoelectric vibrator. Furthermore, not only the piezoelectric vibrator but also other ejection driving sources such as a heating element can be used.

  In the above, the printer 1 has been described as an example of the liquid ejecting apparatus, but the present invention can also be applied to other liquid ejecting apparatuses. For example, the present invention can be applied to a display manufacturing apparatus, an electrode manufacturing apparatus, a chip manufacturing apparatus, and the like.

FIG. 2 is a perspective view illustrating a configuration of a printer. FIG. 3 is a cross-sectional view of a main part of the recording head. FIG. 2 is a block diagram illustrating an electrical configuration of a printer. It is sectional drawing explaining the structure of a vibrator | oscillator unit. It is a wave form diagram explaining the structure of the drive pulse in a drive signal. It is a figure explaining the structure of FFC, (a) is a perspective view, (b) is an AA sectional view. It is a schematic diagram explaining the polarity switching control by a switching circuit. It is a figure which shows the arrangement | sequence of the conductive pattern for the drive signal COM in FFC.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Recording head, 9 ... Printer controller, 10 ... FFC, 18 ... Vibrator unit, 21 ... Piezoelectric vibrator, 35 ... Nozzle, 48 ... Control part, 50 ... Drive signal generation circuit, 52 ... 1st Switching circuit, 53... Second switching circuit, 55... Conductive pattern, 56.

Claims (2)

A liquid ejecting head that ejects liquid from a nozzle by the operation of an ejection drive source, a drive signal generating unit that generates a drive signal for operating the ejection drive source, and a drive signal from the drive signal generating unit A liquid ejecting apparatus comprising: a wiring member for transmitting to the ejection drive source side of the head,
The wiring member has a strip-like shape in which first conductive patterns connected to the positive electrode side of the ejection driving source and second conductive patterns connected to the negative electrode side of the ejection driving source are alternately arranged in the band width direction. Laminated with multiple cables in pairs,
Switching means for switching the polarity of the conductive pattern of either the first cable or the second cable in a pair;
Control means for controlling the switching means,
The control means compares the number of nozzles that simultaneously eject liquid with a predetermined threshold value, and faces the first cable and the second cable when the number of simultaneous ejection nozzles is less than the threshold value. The switching means is controlled so that the polarities of the conductive patterns are different from each other. On the other hand, when the number of simultaneous injection nozzles is equal to or greater than the threshold value, the opposite conductive properties between the first cable and the second cable. The liquid ejecting apparatus, wherein the switching unit is controlled so that the polarities of the patterns are the same. A liquid ejecting head that ejects liquid from a nozzle by the operation of an ejection drive source, a drive signal generating unit that generates a drive signal for operating the ejection drive source, and a drive signal from the drive signal generating unit A wiring member for transmitting to the ejection drive source side of the head,
The wiring member has a strip-like shape in which first conductive patterns connected to the positive electrode side of the ejection driving source and second conductive patterns connected to the negative electrode side of the ejection driving source are alternately arranged in the band width direction. A control method for a liquid ejecting apparatus in which a plurality of cables are paired and laminated,
Compare the number of nozzles that simultaneously eject liquid with a predetermined threshold,
When the number of simultaneous injection nozzles is less than the threshold value, the first cable or the first cable paired so that the conductive patterns facing each other between the first cable and the second cable have different polarities. Switch the polarity of one of the conductive patterns of the second cable,
When the number of simultaneous injection nozzles is equal to or greater than the threshold, the polarity of the one cable is switched so that the polarities of the conductive patterns facing each other between the first cable and the second cable are the same. A control method for a liquid ejecting apparatus.

Images