JP2005246975A - Liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet apparatus which can sufficiently perform an anti-thickening operation for properly maintaining the property of ejection of a liquid droplet even if a thickened state of meniscus of a liquid is uneven. <P>SOLUTION: This liquid jet apparatus is equipped with a head member 4 with a nozzle opening 17. The liquid of the nozzle opening 17 can be jet by a liquid jet means. Thickening of the liquid of the nozzle opening 17 is recovered by a recovery means. The recovery means is a flushing means for performing flushing processing for continuously ejecting the liquid of the nozzle opening 17 as microdroplets. The meniscus of the liquid, which is formed in the nozzle opening 17, is made to greatly recede by the flushing means immediately before each of the microdroplets of the liquid is ejected, and control is so performed that the microdroplets can be ejected from a central part of the meniscus. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid ejecting apparatus including a head member that ejects liquid droplets from a nozzle opening, and more particularly, to a device that prevents liquid thickening at a nozzle opening.

  In an ink jet recording apparatus (a type of liquid ejecting apparatus) such as an ink jet printer or a plotter, a recording head (head member) is moved in the main scanning direction and a recording paper (a type of printing recording medium) is moved in the sub scanning direction. Along with this movement, ink droplets are ejected from the nozzle openings of the recording head in conjunction with this movement, thereby recording an image (character) on the recording paper. The ink droplets (liquid droplets) are ejected, for example, by changing the ink pressure in a pressure generation chamber communicating with the nozzle opening.

  The ink pressure is changed using a pressure generating element, for example, a piezoelectric vibrator (piezoelectric member). In this case, the piezoelectric vibrator is deformed in accordance with the supplied drive pulse, thereby changing the volume of the pressure chamber. This change in volume causes pressure fluctuations in the ink in the pressure chamber, and ink droplets are ejected from the nozzle openings. To do.

  Incidentally, since the ink is exposed to air at the nozzle opening portion of the recording head, the ink solvent (for example, water) gradually evaporates. The evaporation of the ink solvent increases the ink viscosity at the nozzle opening, which deteriorates the image quality of the recorded image. That is, when the ink viscosity of the portion increases, the ejected ink droplets can fly in a direction deviating from the normal direction.

  For this reason, in the ink jet recording apparatus, measures are taken to prevent the ink from thickening at the nozzle opening. As countermeasures against this thickening, there are a flushing operation for forcibly ejecting thickened ink outside the recording area, and an ink agitating operation by slight vibration of the meniscus. Here, the meniscus is the free surface of the ink exposed at the nozzle opening.

  In a conventional flushing operation, an ejection waveform for ejecting ink droplets during a recording operation is used. An example of such a discharge waveform is shown in FIG.

  As shown in FIG. 11, the ejection waveform for ejecting ink droplets generally includes a first voltage increase portion c1 that supplies a voltage that expands the pressure chamber and depressurizes the inside to the piezoelectric member, and the decompressed state. A first voltage maintaining unit c2 that supplies a voltage that maintains the pressure to the piezoelectric member, a first voltage drop unit c3 that supplies the piezoelectric member with a voltage that contracts the pressure chamber and pressurizes the inside, and the pressurization A second voltage maintaining part c4 for supplying a voltage for maintaining the state to the piezoelectric member, and a second voltage increasing part c5 for supplying a voltage for returning the pressure chamber to the original state to the piezoelectric member. Yes.

  In this case, the discharge speed of ink droplets (including ink droplets during the flushing operation) is generally about 7 m / s, and the mass thereof is, for example, 13 ng.

  By the way, when a series of printing processes are completed, the nozzle opening portion of the recording head is generally capped.

  The present inventor has found that, in the case of ink having a high pigment concentration, line thickening, missing dots, etc. may occur in the case of reprinting after capping. Line thickening and missing dots occur when bubbles enter the nozzle openings. The inventor of the present invention analyzed how bubbles enter the nozzle openings as follows.

  In the capped nozzle opening, the ink forming the meniscus is thickened by evaporation of a solvent such as moisture.

  This thickening action proceeds from the periphery of the nozzle opening. The thickening of the ink around the meniscus is confirmed about 2 minutes after the start of capping, but the thickening of the ink at the center of the meniscus is not confirmed until about 5 minutes after the start of capping. That is, the thickened state of the meniscus is non-uniform for about 2 minutes to about 5 minutes after the start of capping.

  In normal flushing control, as shown in FIG. 8B, ink is ejected so as to push out the entire meniscus formed on the nozzle. For this reason, if the thickened state of the meniscus is not uniform between the peripheral portion of the nozzle opening and the central portion of the nozzle opening, the meniscus at the time of the flushing operation becomes non-uniform and becomes fragile. If the flushing operation is continuously performed in a state in which the meniscus is easily broken, an ink pool is generated around the nozzle, the meniscus is broken, and it is considered that there is a high possibility that bubbles finally enter.

  Actually, printing inconveniences such as line thickening and missing dots occur only between 2 minutes and 5 minutes after the start of capping.

  Therefore, when it is considered that the thickened state of the meniscus is not uniform, a kinetic energy not to be defeated by the thickened ink film is given to the ink at the center of the nozzle opening, and ink droplets are ejected. By continuing the flushing operation, it is necessary to perform the flushing operation in such a manner that the thickened ink around the nozzle opening is gradually discharged.

  The present invention has been made in view of such circumstances, and the thickening prevention operation for maintaining good ink droplet ejection characteristics is performed when the thickened state of the ink meniscus is uneven. In addition, an object of the present invention is to provide an ink jet recording apparatus that can perform sufficiently, and in general, a liquid ejecting apparatus.

  The present invention includes a head member having a nozzle opening, liquid ejecting means for ejecting the liquid in the nozzle opening, and recovery means for recovering the thickening of the liquid in the nozzle opening, and the recovery means includes the nozzle Flushing means for performing a flushing process for ejecting the liquid in the opening as fine droplets. The fine liquid droplets ejected by the flushing process have an ejection speed of 8 m / s or more and a mass of 10 ng or less. A liquid ejecting apparatus characterized by the above.

  According to the present invention, control is performed so that the ejection speed of the fine droplets of the ejected liquid is 8 m / s or more and the mass is 10 ng or less. When ejecting minute droplets under such control conditions, the amount of meniscus retreat after ejection is sufficiently suppressed, and the meniscus is not broken even if the thickened state of the meniscus is uneven. This was actually confirmed by various experiments by the present inventors.

  For example, when the nozzle diameter is 25 μm, the preferred liquid droplet weight is 8 to 10 ng.

  Further, if the present invention is expressed functionally, a head member having a nozzle opening, a liquid ejecting means for ejecting the liquid in the nozzle opening, and a recovery means for recovering the thickening of the liquid in the nozzle opening are provided. The recovery means is a flushing means for performing a flushing process for discharging the liquid at the nozzle opening as fine droplets, and the meniscus of the liquid formed at the nozzle opening is obtained by the microfluidic droplet by the flushing means. The liquid ejecting apparatus is characterized in that the liquid jetting apparatus is controlled so that it is drawn in immediately before being discharged and a minute droplet is discharged from the center of the meniscus.

  With a discharge control that allows the meniscus to be drawn in immediately before the liquid droplet discharge and concentrate the kinetic energy on the liquid at the center of the nozzle opening (center of the meniscus), sufficient kinetic energy can be given to the liquid droplet, Breaking down the thickened liquid film and ejecting liquid droplets can prevent the meniscus from collapsing.

  FIG. 9 shows the movement of the meniscus when the liquid droplet is discharged in the case of the present invention. As shown in FIG. 9, when the meniscus is drawn largely immediately before the liquid droplet is discharged, the liquid droplet is not discharged from the entire meniscus (see FIG. 8B), but from the center of the meniscus ( (See FIG. 9B). As a result, it is possible to avoid the liquid having a relatively high viscosity around the nozzle opening from directly affecting the discharge of the liquid droplets, and to realize a more preferable flushing operation.

  Preferably, the head member communicates with the nozzle opening and can store a liquid, and pressure generating means for changing the pressure of the liquid in the pressure generating chamber to discharge a liquid droplet from the nozzle opening; The flushing means has a flushing drive means for driving the pressure generating means.

  More preferably, the pressure generating means includes a piezoelectric member that deforms the pressure generating chamber to discharge liquid droplets from the nozzle openings, and the flushing driving means supplies a driving signal to the piezoelectric member. Yes.

  More preferably, the driving signal supplied to the piezoelectric member by the flushing driving means maintains a first voltage increasing portion for supplying the piezoelectric member with a voltage that expands the pressure generating chamber and depressurizes the inside, and maintains the reduced pressure state. A first voltage maintaining unit that supplies such a voltage to the piezoelectric member, a first voltage drop unit that supplies a voltage to the piezoelectric member to return the pressure generating chamber to a mildly decompressed state, and maintains the mildly decompressed state. A second voltage maintaining unit that supplies the voltage to the piezoelectric member, and a second voltage drop unit that supplies the piezoelectric member with a voltage that returns the pressure generating chamber to the original state.

  More preferably, the first voltage raising unit has an auxiliary voltage maintaining unit that temporarily maintains a light or moderate pressure reduction state in the course of expanding the pressure generation chamber to reduce the inside. ing.

  Preferably, the flushing means has two flushing modes that can be switched, and in the first flushing mode, a fine droplet of liquid ejected in the flushing process has an ejection speed of 8 m / second. s or more, and the mass is 10 ng or less. In the second flushing mode, the fine droplets of the liquid ejected in the flushing process have a mass of 12 ng or more.

  In this case, preferably, a head scanning mechanism that moves the head member in the main scanning direction, a capping mechanism that is provided in a movable region of the head member and that can seal a nozzle opening, and the capping mechanism. And a control timer for measuring the time during which the nozzle opening is sealed, and a control means for switching the flushing mode of the flushing means based on the time measured by the measurement timer.

  For example, the flushing means is operated in the first flushing mode only when the time measured by the measurement timer is between a predetermined first elapsed time and a predetermined second elapsed time, and in other cases The second flushing mode is activated.

  Specifically, for example, the predetermined first elapsed time is 2 minutes, and the predetermined second elapsed time is 5 minutes.

  Alternatively, the flushing means is operated in the first flushing mode at the start of the flushing process, and is operated in the second flushing mode after a predetermined time has elapsed after the start of the flushing process.

  Preferably, the head member communicates with the nozzle opening and accommodates a liquid, and a pressure generating means for discharging a liquid droplet from the nozzle opening by changing the pressure of the liquid in the pressure generating chamber. The flushing means has a flushing drive means for driving the pressure generation means, and the pressure generation means deforms the pressure generation chamber to discharge a liquid droplet from the nozzle opening. The flushing driving means supplies a first drive signal to the piezoelectric member in the first flushing mode, and sends a second drive signal to the piezoelectric member in the second flushing mode. The first drive signal and the second drive signal are formed by selectively using a partial waveform of the common drive signal.

  In this case, for example, the first drive signal includes a first voltage increasing unit that supplies the piezoelectric member with a voltage that expands the pressure generation chamber and depressurizes the inside, and a voltage that maintains the reduced pressure state. A first voltage maintaining unit for supplying to the piezoelectric member, a first voltage dropping unit for supplying a voltage to the piezoelectric member to return the pressure generating chamber to a mildly decompressed state, and a voltage for maintaining the mildly decompressed state to the piezoelectric member. And a second voltage drop unit that supplies the piezoelectric member with a voltage that returns the pressure generating chamber to its original state. The second drive signal is a pressure generating chamber. A first voltage raising section for supplying a voltage to the piezoelectric member so as to decompress the interior and decompressing the inside; a first voltage maintaining section for supplying a voltage to the piezoelectric member to maintain the decompressed state; and a pressure generating chamber. Supply the piezoelectric member with a voltage that shrinks and pressurizes the interior A first voltage drop unit; a second voltage maintaining unit that supplies a voltage that maintains the pressurized state to the piezoelectric member; and a second that supplies the piezoelectric member with a voltage that returns the pressure generating chamber to the original state. And a voltage rising portion.

  Further, the present invention comprises a head member having a nozzle opening, a liquid ejecting means for ejecting the liquid in the nozzle opening, and a recovery means for recovering the thickening of the liquid in the nozzle opening, the recovery means comprising: Flushing means for performing a flushing process for discharging the liquid in the nozzle opening as fine droplets, wherein the head member communicates with the nozzle opening and can store the liquid, and the pressure of the liquid in the pressure generation chamber And pressure generating means for discharging liquid droplets from the nozzle openings, and the liquid ejecting means drives the pressure generating means based on a liquid ejecting signal. The flushing means drives the pressure generating means based on a flushing drive signal, and the flushing drive signal It is liquid-jet apparatus characterized that are generated separately independent of the issue.

  According to the present invention, since the flushing drive signal is generated separately and independently from the liquid ejection signal, the degree of freedom in designing the flushing drive signal is remarkably improved, and an optimal flushing operation can be realized.

  In this case, for example, the pressure generating means includes a piezoelectric member that deforms the pressure generating chamber and discharges liquid droplets from the nozzle openings.

  Also in this case, it is preferable that the fine droplets of the liquid discharged by the flushing process have a discharge speed of 8 m / s or more and a mass of 10 ng or less.

  Alternatively, the liquid meniscus formed at the nozzle opening is controlled to be drawn largely by the flushing means immediately before each minute droplet of liquid is discharged, and the minute droplet is discharged from the center of the meniscus. It is preferable.

  Further, the present invention comprises a head member having a nozzle opening, a liquid ejecting means for ejecting the liquid in the nozzle opening, and a recovery means for recovering the thickening of the liquid in the nozzle opening, the recovery means comprising: An apparatus for controlling a liquid ejecting apparatus, characterized in that it is a flushing means for performing a flushing process for ejecting the liquid at the nozzle opening as a microdroplet. The control device controls the flushing means so that the discharge speed is 8 m / s or more and the mass is 10 ng or less.

  Alternatively, the present invention includes a head member having a nozzle opening, a liquid ejecting unit that ejects the liquid in the nozzle opening, and a recovery unit that recovers the thickening of the liquid in the nozzle opening, and the recovery unit includes: An apparatus for controlling a liquid ejecting apparatus, characterized in that it is a flushing means for performing a flushing process for discharging the liquid at the nozzle opening as fine droplets, wherein the liquid meniscus formed at the nozzle opening The control device is characterized in that the flushing means is controlled so that it is drawn in immediately before each minute droplet is ejected and the minute droplet is ejected from the center of the meniscus.

  Alternatively, the present invention includes a head member having a nozzle opening, a liquid ejecting unit that ejects the liquid in the nozzle opening, and a recovery unit that recovers the thickening of the liquid in the nozzle opening, and the recovery unit includes: Flushing means for performing a flushing process for discharging the liquid in the nozzle opening as fine droplets, wherein the head member communicates with the nozzle opening and can store the liquid, and the pressure of the liquid in the pressure generation chamber And pressure generating means for discharging liquid droplets from the nozzle openings, and the liquid ejecting means drives the pressure generating means based on a liquid ejecting signal. The flushing means controls the liquid ejecting apparatus, wherein the pressure generating means is driven based on a flushing drive signal. A location, the flushing drive signal and with said liquid injection signal, a control device, characterized in that is adapted to generate a separate and independent.

  Each of the above control devices can be realized by a computer system.

  Note that a program for causing the computer system to realize each control device and a computer-readable recording medium recording the program are also subject to protection in this case.

  Here, the recording medium includes not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.

  In the flushing operation according to the present invention, discharge is performed so as not to lose the thickened liquid film. Therefore, even if the thickened state of the meniscus is not uniform, the meniscus is not broken. Therefore, bubbles can be prevented from entering the nozzle openings, and the liquid droplet ejection characteristics can be maintained well.

  Further, according to the present invention, since the flushing drive signal is generated separately and independently from the liquid ejection signal, the design freedom of the flushing drive signal is remarkably improved, and an optimal flushing operation can be realized. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the ink jet recording apparatus according to the present embodiment is an ink jet printer 1 and includes a carriage 5 having a cartridge holder portion 3 capable of holding an ink cartridge 2 and a recording head 4 (head member). I have. The carriage 5 is reciprocated along the main scanning direction by a head scanning mechanism.

  The head scanning mechanism includes a guide member 6 installed in the left-right direction of the housing, a pulse motor 7 provided on one side of the housing, a drive pulley 8 connected to the rotating shaft of the pulse motor 7 and driven to rotate. An idler pulley 9 attached to the other side of the housing, a timing belt 10 spanned between the drive pulley 8 and the idler pulley 9 and coupled to the carriage 5, and a controller for controlling the rotation of the pulse motor 7. 11 (see FIG. 5). Accordingly, by operating the pulse motor 7, the carriage 5, that is, the recording head 4 can be reciprocated in the main scanning direction which is the width direction of the recording paper 12.

  The printer 1 also has a paper feed mechanism that feeds a recording medium such as the recording paper 12 in the paper feed direction (sub-scanning direction). The paper feed mechanism is composed of a paper feed motor 13 and a paper feed roller 14. A recording medium such as the recording paper 12 is sequentially sent out in conjunction with the recording operation.

  The head scanning mechanism and the paper feed mechanism of the present embodiment are configured to be compatible with large-sized recording paper 12 of about B0 size. Further, the printer 1 according to the present embodiment is configured to execute a recording operation (perform unidirectional recording) when the recording head 4 moves forward.

  A home position and a standby position of the recording head 4 (carriage 5) are set in an end area within the movement range of the carriage 5 and outside the recording area. As shown in FIG. 2A, the home position is set at one end (right side in the drawing) of the head movement range in which the recording head 4 can move. Further, the standby position is set substantially adjacent to the home position on the recording area side.

  The present invention can also be applied to a printer configured to execute a recording operation (perform bi-directional recording) both when the recording head 4 moves forward and backward. In such a printer, as shown in FIG. 2B, in addition to the first standby position WP1 substantially adjacent to the home position, a second standby position WP2 is provided at the end opposite to the home position. Can be.

  The home position is a place where the recording head 4 moves and stays when recording is not performed when the power is turned off or for a long time. When the recording head 4 is located at the home position, as shown in FIG. 3D, the cap member 15 of the capping mechanism contacts the nozzle plate 16 (see FIG. 4) to seal the nozzle opening 17 (see FIG. 4). Stop. The cap member 15 is a member obtained by molding an elastic member such as rubber into a substantially square tray shape whose upper surface is open, and a moisturizing material such as felt is attached inside. By sealing the recording head 4 with the cap member 15, the inside of the cap is kept at high humidity, and evaporation of the ink solvent from the nozzle openings 17 is alleviated.

  The standby position is a position that becomes a starting point when scanning the recording head 4. That is, the recording head 4 normally stands by at this standby position, is scanned from the standby position to the recording area side during the recording operation, and returns to the standby position when the recording operation is completed.

  In the case of a printer that performs bi-directional recording, referring to FIG. 2B, the recording head 4 is scanned from the standby state at the first standby position WP1 to the second standby position WP2 side to move forward. Record the hour. When this recording operation ends, the recording apparatus waits at the second standby position WP2. Next, the recording head 4 is scanned from the standby state at the second standby position WP2 to the first standby position WP1 side to perform a recording operation at the time of backward movement. When this recording operation ends, the recording apparatus waits at the first standby position WP1. Thereafter, the recording operation during the forward movement and the recording operation during the backward movement are repeatedly performed alternately.

  The standby position is provided with an ink receiving member for collecting ink discharged by the recording head 4 by a flushing operation (a kind of maintenance operation). In the present embodiment, the cap member 15 also serves as an ink receiving member. That is, as shown in FIG. 3A, the cap member 15 is usually disposed at a position below the standby position of the recording head 4 (position slightly spaced below the nozzle plate 16). Then, as the recording head 4 moves to the home position, as shown in FIG. 3D, the recording head 4 moves obliquely upward (home position side and nozzle plate 16 side) to seal the nozzle opening 17. .

  In the case of a printer that performs bidirectional recording, as shown in FIG. 2B, an ink receiving member 18 is also disposed at the second standby position WP2. The ink receiving member 18 can be constituted by, for example, a box-like flushing box having an opening surface facing the recording head 4.

  Further, in the present embodiment, an acceleration area is set between the standby position and the recording area. The acceleration area is an area for accelerating the scanning speed of the recording head 4 to a predetermined speed.

  Next, the recording head 4 will be described. As shown in FIG. 4, the recording head 4 includes a comb-like piezoelectric vibrator 21 inserted into a storage chamber 72 of a box-like case 71 made of plastic, for example, through one opening, and a comb-like tip portion. 21a faces the other opening. The flow path unit 74 is joined to the surface (lower surface) of the case 71 on the other opening side, and the comb-shaped tip portion 21 a is in contact with and fixed to a predetermined portion of the flow path unit 74.

  The piezoelectric vibrator 21 is formed by cutting a plate-like vibrator plate in which common internal electrodes 21c and individual internal electrodes 21d are alternately stacked with a piezoelectric body 21b interposed therebetween, and cutting the comb-like shape in accordance with the dot formation density. It is. Then, by applying a potential difference between the common internal electrode 21c and the individual internal electrode 21d, each piezoelectric vibrator 21 expands and contracts in the vibrator longitudinal direction orthogonal to the stacking direction.

  The channel unit 74 is configured by laminating the nozzle plate 16 and the elastic plate 77 on both sides with the channel forming plate 75 interposed therebetween.

  The flow path forming plate 75 communicates with a plurality of nozzle openings 17 formed in the nozzle plate 16 and is arranged at least at one end of each pressure generating chamber 22 and a plurality of pressure generating chambers 22 arranged with a pressure generating chamber partition therebetween. This is a plate material on which a plurality of ink supply portions 82 communicating with each other and an elongated common ink chamber 83 communicating with all the ink supply portions 82 are formed. For example, an elongated common ink chamber 83 is formed by etching a silicon wafer, and the pressure generation chambers 22 are formed in accordance with the pitch of the nozzle openings 17 along the longitudinal direction of the common ink chamber 83. A groove-shaped ink supply part 82 may be formed between the ink 22 and the common ink chamber 83. In this case, the ink supply unit 82 is connected to one end of the pressure generating chamber 22, and the nozzle opening 17 is disposed in the vicinity of the end opposite to the ink supply unit 82. The common ink chamber 83 is a chamber for supplying the ink stored in the ink cartridge to the pressure generating chamber 22, and an ink supply pipe 84 is communicated with substantially the center in the longitudinal direction.

  The elastic plate 77 is laminated on the surface of the flow path forming plate 75 opposite to the nozzle plate 16, and a double structure in which a polymer film such as PPS is laminated on the lower surface side of the stainless steel plate 87 as an elastic film 88. It is. Then, an island portion 89 for abutting and fixing the piezoelectric vibrator 21 is formed by etching the portion of the stainless plate 87 corresponding to the pressure generating chamber 22.

  In the recording head 4 having the above configuration, by extending the piezoelectric vibrator 21 in the longitudinal direction of the vibrator, the island portion 89 is pressed toward the nozzle plate 16 and the elastic film 88 around the island portion 89 is deformed. The pressure generation chamber 22 contracts. When the piezoelectric vibrator 21 is contracted in the longitudinal direction from the contracted state of the pressure generating chamber 22, the pressure generating chamber 22 expands due to the elasticity of the elastic film 88. When the pressure generating chamber 22 is once expanded and then contracted, the ink pressure in the pressure generating chamber 22 is increased and ink droplets are ejected from the nozzle openings 17.

  That is, in the recording head 4, the capacity of the corresponding pressure chamber 22 changes as the piezoelectric vibrator 21 is charged / discharged. By utilizing such pressure fluctuations in the pressure chamber 22, ink droplets can be ejected from the nozzle openings 17, or the meniscus (the free surface of the ink exposed at the nozzle openings 17) can be finely vibrated.

  In place of the longitudinal vibration vibration mode piezoelectric vibrator 21 described above, a so-called flexural vibration mode piezoelectric vibrator can be used. The piezoelectric vibrator in the flexural vibration mode is a piezoelectric vibrator that contracts the pressure chamber by deformation due to charging and expands the pressure chamber by deformation due to discharge.

  The recording head 4 is preferably a multicolor recording head capable of recording a plurality of different colors. The multicolor recording head includes a plurality of head units, and the type of ink used for each head unit is set.

  For example, in a recording head having four head units, a black head unit capable of ejecting black ink, a cyan head unit capable of ejecting cyan ink, a magenta head unit capable of ejecting magenta ink, and a yellow ink And a yellow head unit capable of discharging water.

  Next, the electrical configuration of the printer 1 will be described. As shown in FIG. 5, the ink jet printer 1 includes a printer controller 30 and a print engine 31.

  The printer controller 30 includes an external interface (external I / F) 32, a RAM 33 that temporarily stores various data, a ROM 34 that stores a control program, a control unit 11 that includes a CPU, a clock, and the like. An oscillation circuit 35 that generates a signal, a drive signal generation circuit 36 that generates a drive signal to be supplied to the recording head 4, and dot pattern data (bitmap data) developed based on the drive signal and print data And the like, and an internal interface (internal I / F) 37 for transmitting the information to the print engine 31 and a measurement timer 38.

  The external I / F 32 receives print data including, for example, a character code, a graphic function, image data, and the like from a host computer (not shown). Further, a vichy signal (BUSY) and an acknowledge signal (ACK) are output to the host computer or the like through the external I / F 32.

  The RAM 33 has a reception buffer, an intermediate buffer, an output buffer, and a work memory (not shown). The reception buffer temporarily stores the print data received via the external I / F 32, the intermediate buffer stores the intermediate code data converted by the control unit 11, and the output buffer stores dot pattern data. Remember. Here, the dot pattern data is print data obtained by decoding (translating) intermediate code data (for example, gradation data).

  In addition to a control program (control routine) for performing various data processing, the ROM 34 stores font data, graphic functions, and the like. Further, the ROM 34 also stores setting data for maintenance operation as maintenance information holding means.

  The control unit 11 performs various controls according to a control program stored in the ROM 34. For example, the print data in the reception buffer is read and the print data is converted into intermediate code data, and the intermediate code data is stored in the intermediate buffer. In addition, the control unit 11 analyzes the intermediate code data read from the intermediate buffer and develops (decodes) it into dot pattern data by referring to the font data and graphic functions stored in the ROM 34. Then, the control unit 11 stores the dot pattern data in the output buffer after performing the necessary decoration processing.

  If dot pattern data for one line that can be recorded by one main scan of the recording head 4 is obtained, the dot pattern data for one line is sequentially transferred from the output buffer to the recording head 4 through the internal I / F 37. Output to the electric drive system 39, the carriage 5 is scanned, and printing for one line is performed. When dot pattern data for one line is output from the output buffer, the developed intermediate code data is erased from the intermediate buffer, and the development process for the next intermediate code data is performed.

  Further, the control unit 11 controls a maintenance operation (recovery operation) performed prior to the recording operation by the recording head 4.

  The measurement timer 38 measures the time during which the nozzle openings 17 of the recording head 4 are sealed (capped) by the cap member 15.

  The print engine 31 includes a paper feed motor 13 as a paper feed mechanism, a pulse motor 7 as a head scanning mechanism, and an electric drive system 39 of the recording head 4.

  Next, the electric drive system 39 of the recording head 4 will be described. As shown in FIG. 5, the electric drive system 39 includes a shift register circuit 40, a latch circuit 41, a level shifter circuit 42, a switch circuit 43, and the piezoelectric vibrator 21 that are electrically connected in order. The shift register circuit 40, the latch circuit 41, the level shifter circuit 42, the switch circuit 43, and the piezoelectric vibrator 21 are provided for each nozzle opening 17 of the recording head 4.

  In this electric drive system 39, when the print data applied to the switch circuit 43 is “1”, the switch circuit 43 is connected and a drive signal is directly applied to the piezoelectric vibrator 21. It deforms according to the signal waveform. On the other hand, when the print data applied to the switch circuit 43 is “0”, the switch circuit 43 is disconnected and the supply of the drive signal to the piezoelectric vibrator 21 is cut off.

  In this way, a drive signal can be selectively supplied to each piezoelectric vibrator 21 based on the print data. For this reason, depending on the given print data, ink droplets can be ejected from the nozzle openings 17 or the meniscus can be slightly vibrated.

  In the present embodiment, a two-mode flushing operation is realized. For the normal flushing operation, the drive signal FA shown in FIG. 6 is supplied to each piezoelectric vibrator 21. On the other hand, the driving signal FB shown in FIG. 7 is supplied to each piezoelectric vibrator 21 in order to perform the flushing operation when the meniscus is not uniformly thickened. The drive signal FA and the drive signal FB are generated in the drive signal generation circuit 36.

  Here, the drive signal FA and the drive signal FB can be generated by the drive signal generation circuit 36 in a manner that uses the ejection waveform for ejecting ink droplets during the recording operation, as in the conventional case.

  However, as shown in FIG. 12, the drive signal generation circuit 36 discharges ink droplets during the recording operation separately from the main signal generation unit 36a that generates an ejection waveform for discharging ink droplets during the recording operation. The flushing signal generator 36b for generating the drive signal FA and the drive signal FB independently of the discharge waveform may be provided. Here, the selection unit 36c functions as a signal selection unit. In this case, the degree of freedom in selecting (designing) the form (waveform) of the drive signal FA and the drive signal FB is significantly increased.

  Further, in the flushing operation, selection of a drive signal (drive signal FA or drive signal FB) to be supplied to each piezoelectric vibrator 21 (flushing means) is performed by the control unit 11. In this case, the control unit 11 selects a drive signal based on the time measured by the measurement timer 38, that is, switches the flushing mode.

  Specifically, the drive signal FB is supplied to each piezoelectric vibrator 21 only when the time measured by the measurement timer 38 is between a predetermined first elapsed time and a predetermined second elapsed time ( In other cases, the drive signal FA is supplied (actuated in the second flushing mode).

  Here, the predetermined first elapsed time is set to 2 minutes, and the predetermined second elapsed time is set to 5 minutes. However, the predetermined first elapsed time and the predetermined second elapsed time can be changed as appropriate.

  As shown in FIG. 6, the drive signal FA (second drive signal) includes a first voltage increasing portion sa <b> 1 that supplies the piezoelectric vibrator 21 with a voltage that expands the pressure chamber 22 and depressurizes the inside, and the reduced pressure. A first voltage maintaining unit sa2 that supplies a voltage that maintains the state to the piezoelectric vibrator 21 and a first voltage drop unit that supplies the piezoelectric vibrator 21 with a voltage that causes the pressure chamber 22 to contract and pressurize the inside. sa3, a second voltage maintaining unit sa4 that supplies the piezoelectric vibrator 21 with a voltage that maintains the pressurized state, and a second voltage that supplies the piezoelectric vibrator 21 with a voltage that returns the pressure chamber 22 to the original state. 2 voltage rise part sa5.

  On the other hand, as shown in FIG. 7, the drive signal FB maintains the pressure-reducing portion sb <b> 1 that supplies the piezoelectric vibrator 21 with a voltage that expands the pressure chamber 22 and depressurizes the inside. A first voltage maintaining unit sb2 that supplies such voltage to the piezoelectric vibrator 21, a first voltage drop unit sb3 that supplies the piezoelectric chamber 21 with a voltage that returns the pressure chamber 22 to a mildly reduced pressure state, and the mild The second voltage maintaining unit sb4 that supplies the piezoelectric vibrator 21 with a voltage that maintains the reduced pressure state, and the second voltage drop unit that supplies the piezoelectric vibrator 21 with a voltage that returns the pressure chamber 22 to the original state. sb5.

  In this case, the first voltage increase unit sb1 has an auxiliary voltage maintaining unit sb12 that temporarily maintains a moderate pressure-reducing state in the course of expanding the pressure chamber 22 to depressurize the inside. A voltage raising unit sb11 is provided for the purpose of raising the driving potential to the voltage value of the auxiliary voltage maintaining unit sb12 and connecting the driving waveforms. However, the auxiliary voltage maintaining unit sb12 is not an essential feature of the present invention.

Next, the operation of the printer 1 will be described with reference to FIGS.
When the power is turned on, a necessary initialization operation is first performed. Thereafter, the recording head 4 stands by at the standby position (state shown in FIG. 3A). When the print data for one line is output from the output buffer of the RAM 33, the recording head 4 performs a maintenance operation (recovery operation) prior to the recording operation.

  This maintenance operation is performed in order to maintain the ink droplet ejection capability of the recording head 4, and includes, for example, a flushing operation and a fine vibration operation, which are appropriately selected and executed.

  Specifically, the flushing operation is an operation for forcibly discharging ink from the recording head 4 toward the ink receiving member (cap member 15) outside the recording area. The flushing operation is performed while stopping at the standby position. When the flushing operation is performed, the thickened ink in the vicinity of the nozzle opening 17 is discharged out of the recording head 4 and replaced with ink in a good state.

  As described above, the fine vibration operation is an operation of causing the meniscus to vibrate slightly by changing the pressure of the pressure chamber 22 to such an extent that ink droplets are not ejected. In this embodiment, the recording head 4 stops at the standby position. This is done while moving through the acceleration region.

  The flushing operation of the present embodiment will be described in detail. The time measured by the measurement timer 38 is a predetermined first elapsed time (in this case, 2 minutes) and a predetermined second elapsed time (in this case, 5 minutes). The flushing operation using the drive signal FA (see FIG. 6) is performed except when the time is between.

  Ink droplets ejected continuously in the flushing operation in the second mode have an ejection speed of about 7 m / s and a mass of 13 ng. At this time, the state of the meniscus changes as shown in FIG.

  On the other hand, when the time measured by the measurement timer 38 is between a predetermined first elapsed time (in this case, 2 minutes) and a predetermined second elapsed time (in this case, 5 minutes), the drive signal FB (FIG. 7). The flushing operation is performed using (see).

  Ink droplets continuously ejected in the flushing operation in the first mode have an ejection speed of about 10 m / s and a mass of 9 ng. At this time, the state of the meniscus changes as shown in FIG.

  Further, as shown in FIG. 9, when the meniscus is drawn largely immediately before ink droplet ejection, ink droplets are ejected not from the entire meniscus (see FIG. 8B) but from the center of the meniscus. (See FIG. 9B). This avoids that the highly thick ink around the nozzle opening directly affects the ejection of ink droplets, realizes a more favorable flushing operation, and the meniscus thick state is uneven. But the meniscus never breaks.

  In the present embodiment, only when the time measured by the measurement timer 38 is between a predetermined first elapsed time (in this case, 2 minutes) and a predetermined second elapsed time (in this case, 5 minutes). A flushing operation in one mode is performed. This is because, in the second mode, more ink can be ejected in a shorter time, and the general flushing effect is larger. Therefore, the second mode has the exception of the case where the inconvenience occurs in the flushing operation in the second mode. This is because the flushing operation is preferable.

  As a modification of the present embodiment, the control unit 11 performs a flushing operation with the drive signal FB at the start of the flushing process, and performs a flushing operation with the drive signal FA after a predetermined time has elapsed after the start of the flushing process. The flushing mode may be selected as described above.

  In addition, the drive signal FA and the drive signal FB are preferably extracted and generated from a common signal as shown in FIG. 10 using a selected LAT pulse. The common signal mentioned here is a common signal that is also used as an ejection waveform for ejecting ink droplets during a recording operation. For example, in the waveform of the drive signal FB, a waveform obtained by lowering the voltage value for maintaining the reduced pressure state of the pressure chamber 22 by about 3 V can be used as the ejection waveform of the minute ink droplets. According to such a discharge waveform, a minute ink droplet having a mass of 7 ng can be discharged at a discharge speed of 8 m / s.

  Alternatively, the common signal as shown in FIG. 10 is common to the drive signal FA and the drive signal FB for only the flushing operation, which is different from the ejection waveform for ejecting ink droplets during the recording operation, as described above. It may be a signal. In this case, the degree of freedom in selecting (designing) the form (waveform) of the drive signal FA and the drive signal FB is significantly improved.

  Alternatively, the drive signal FA and the drive signal FB may be generated independently.

  Further, particularly preferable ranges of the mass and the ejection speed of the ink droplets ejected in the first flushing mode are 8 to 10 ng and 9 to 15 m / s when the nozzle diameter is 25 μm.

  Furthermore, various additions, changes, and the like can be made within the scope of the gist of the present invention described above with respect to the above-described embodiment.

  For example, the pressure generating element that changes the volume of the pressure chamber 22 is not limited to the piezoelectric vibrator 21. For example, a magnetostrictive element may be used as a pressure generating element, and the pressure chamber 22 may be expanded and contracted by the magnetostrictive element to cause pressure fluctuations, or a heating element may be used as the pressure generating element. You may comprise so that a pressure fluctuation may be produced in the pressure chamber 22 by the bubble which expands / contracts with heat.

  As described above, the printer controller 30 can be configured by a computer system. However, a program for causing the computer system to realize each element and a computer-readable recording medium 201 that records the program are also subject to protection in this case. It is.

  Further, when each of the above elements is realized by a program such as an OS that operates on a computer system, a program including various instructions for controlling the program such as the OS and a recording medium 202 that records the program are also included in the present invention. It is a protection target.

  Here, the recording media 201 and 202 include not only a floppy disk or the like that can be recognized as a single unit, but also a network that propagates various signals.

  Although the above description has been made with respect to an ink jet recording apparatus, the present invention is intended for a wide range of liquid ejecting apparatuses in general. As an example of the liquid, in addition to ink, glue, nail polish or the like can be used.

1 is a schematic perspective view of an ink jet recording apparatus according to an embodiment of the present invention. 2A and 2B are schematic diagrams for explaining a scanning range of a recording head, in which FIG. 3A shows a scanning range of a printer that performs unidirectional recording, and FIG. 4A and 4B are schematic diagrams for explaining the operation of the recording head, in which FIG. 5A shows a state where the recording head is positioned at the standby position, FIG. (D) shows a state when the vehicle is returned to the standby position from the side, and FIG. FIG. 3 is a diagram illustrating a configuration of a recording head. FIG. 2 is a schematic block diagram illustrating the configuration of the ink jet recording apparatus according to the embodiment of FIG. 1. It is a figure which shows an example of the drive signal for 2nd flushing modes. It is a figure which shows an example of the drive signal for 1st flushing modes. It is a figure which shows the change of the meniscus at the time of the ink droplet discharge control by the drive signal shown in FIG. It is a figure which shows the change of the meniscus at the time of the ink droplet discharge control by the drive signal shown in FIG. It is a figure which shows an example of the common drive signal which has the partial waveform corresponding to the drive signal for 1st flushing modes, and the partial waveform corresponding to the drive signal for 2nd flushing modes. It is a figure which shows an example of the drive signal for small ink droplet discharge. It is a schematic block diagram explaining the structure of the inkjet recording device of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer 2 Ink cartridge 3 Cartridge holder part 4 Recording head 5 Carriage 6 Guide member 7 Pulse motor 8 Drive pulley 9 Free-wheel pulley 10 Timing belt 11 Control part 12 Recording paper 13 Paper feed motor 14 Paper feed roller 15 Cap member 16 Nozzle plate 17 Nozzle opening 18 Ink receiving member 21 Piezoelectric vibrator 21a Comb-shaped tip 22 Pressure generating chamber 30 Printer controller 31 Print engine 32 External interface 33 RAM
34 ROM
35 Oscillator 36 Drive signal generator 36a Main signal generator 36b Flushing signal generator 36c Selector 37 Internal interface 38 Measurement timer 39 Recording head electric drive system 40 Shift register circuit 41 Latch circuit 42 Level shifter circuit 43 Switch circuit 71 Case 72 Storage chamber 74 Channel unit 75 Channel forming plate 77 Elastic plate 80 Nozzle opening 82 Ink supply portion 83 Common ink chamber 84 Ink supply tube 87 Stainless steel plate 88 Elastic film 89 Island portion

Claims (24)

A head member having a nozzle opening;
Liquid ejecting means for ejecting the liquid of the nozzle opening;
Recovery means for recovering the thickening of the liquid in the nozzle opening;
With
The recovery means is a flushing means for performing a flushing process for discharging the liquid at the nozzle opening as fine droplets,
The liquid meniscus formed in the nozzle opening is controlled to be drawn largely by the flushing means immediately before each minute droplet of liquid is discharged and to be discharged from the center of the meniscus. A liquid ejecting apparatus. The head member further includes a pressure generation chamber that communicates with the nozzle opening and can store a liquid, and a pressure generation unit that changes the pressure of the liquid in the pressure generation chamber to discharge a liquid droplet from the nozzle opening. And
The liquid ejecting apparatus according to claim 1, wherein the flushing unit includes a flushing driving unit that drives the pressure generating unit. The pressure generating means has a piezoelectric member that deforms the pressure generating chamber to discharge liquid droplets from the nozzle openings,
The liquid ejecting apparatus according to claim 2, wherein the flushing driving unit supplies a driving signal to the piezoelectric member. The drive signal supplied to the piezoelectric member by the flushing drive means is
A first voltage raising unit for supplying a voltage to the piezoelectric member so as to expand the pressure generating chamber and decompress the inside;
A first voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the reduced pressure state;
A first voltage drop unit for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to a slightly reduced pressure state;
A second voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the mild decompression state;
A second voltage drop unit for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to the original state;
The liquid ejecting apparatus according to claim 3, further comprising: The first voltage raising unit includes an auxiliary voltage maintaining unit that temporarily maintains a light or moderate reduced pressure state in the course of expanding the pressure generating chamber to reduce the inside. The liquid ejecting apparatus according to claim 4. The flushing means has two flushing modes that can be switched,
In the first flushing mode, the fine droplets of liquid ejected in the flushing process have an ejection speed of 8 m / s or more and a mass of 10 ng or less,
6. The liquid ejecting apparatus according to claim 1, wherein in the second flushing mode, the liquid droplets ejected in the flushing process have a mass of 12 ng or more. A head scanning mechanism for moving the head member in the main scanning direction;
A capping mechanism provided in a movable region of the head member and capable of sealing a nozzle opening;
A measurement timer for measuring the time during which the nozzle opening is sealed by the capping mechanism;
Control means for switching the flushing mode of the flushing means based on the time measured by the measurement timer;
The liquid ejecting apparatus according to claim 6, further comprising: The flushing means is operated in the first flushing mode only when the time measured by the measurement timer is between the predetermined first elapsed time and the predetermined second elapsed time. In other cases, The liquid ejecting apparatus according to claim 7, wherein the liquid ejecting apparatus is operated in a two-flushing mode. The predetermined first elapsed time is 2 minutes;
The liquid ejecting apparatus according to claim 8, wherein the predetermined second elapsed time is 5 minutes. The flushing means is operated in the first flushing mode at the start of the flushing process, and is operated in the second flushing mode after a predetermined time has elapsed after the start of the flushing process. The liquid ejecting apparatus according to claim 7. The head member includes a pressure generation chamber that communicates with the nozzle opening and can store a liquid, and a pressure generation unit that changes the pressure of the liquid in the pressure generation chamber to discharge a liquid droplet from the nozzle opening. And
The flushing means has a flushing drive means for driving the pressure generating means,
The pressure generating means has a piezoelectric member that deforms the pressure generating chamber to discharge liquid droplets from the nozzle openings,
The flushing driving means supplies a first drive signal to the piezoelectric member in the first flushing mode, and supplies a second drive signal to the piezoelectric member in the second flushing mode. ,
The first drive signal and the second drive signal are formed by selectively using a partial waveform of the common drive signal. Liquid ejector. The first drive signal is
A first voltage raising unit for supplying a voltage to the piezoelectric member so as to expand the pressure generating chamber and depressurize the inside;
A first voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the reduced pressure state;
A first voltage drop unit for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to a slightly reduced pressure state;
A second voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the mild decompression state;
A second voltage drop unit for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to the original state;
Have
The second drive signal is
A first voltage raising unit for supplying a voltage to the piezoelectric member so as to expand the pressure generating chamber and depressurize the inside;
A first voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the reduced pressure state;
A first voltage drop unit for supplying a voltage to the piezoelectric member so as to contract the pressure generating chamber and pressurize the inside;
A second voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the pressurized state;
A second voltage raising section for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to the original state;
The liquid ejecting apparatus according to claim 11, further comprising: A head member having a nozzle opening;
Liquid ejecting means for ejecting the liquid of the nozzle opening;
Recovery means for recovering the thickening of the liquid in the nozzle opening;
With
The recovery means is an apparatus for controlling a liquid ejecting apparatus, characterized in that the recovery means is a flushing means for performing a flushing process for discharging the liquid at the nozzle opening as fine droplets,
The flushing means is controlled so that the liquid meniscus formed in the nozzle opening is drawn largely immediately before each minute droplet of liquid is ejected and the minute droplet is ejected from the center of the meniscus. Control device. The flushing means has two flushing modes that can be switched,
The control device includes:
In the first flushing mode, the fine droplets of liquid ejected in the flushing process have an ejection speed of 8 m / s or more and a mass of 10 ng or less,
14. The control device according to claim 13, wherein in the second flushing mode, the flushing means is controlled so that the fine droplets of liquid ejected in the flushing process have a mass of 12 ng or more. The liquid ejecting apparatus includes:
A head scanning mechanism for moving the head member in the main scanning direction;
A capping mechanism provided in a movable region of the head member and capable of sealing a nozzle opening;
A measurement timer for measuring the time during which the nozzle opening is sealed by the capping mechanism;
Is further provided,
The control device according to claim 14, wherein the control device is configured to switch a flushing mode of the flushing means based on a time measured by a measurement timer. The control device operates the flushing means in the first flushing mode only when the time measured by the measurement timer is between the predetermined first elapsed time and the predetermined second elapsed time, The control device according to claim 15, wherein the control device is operated in a second flushing mode. The predetermined first elapsed time is 2 minutes;
The control device according to claim 16, wherein the predetermined second elapsed time is 5 minutes. The control device operates the flushing means in the first flushing mode at the start of the flushing process, and operates in the second flushing mode after a lapse of a predetermined time after the start of the flushing process. The control device according to claim 15, wherein: The head member includes a pressure generation chamber that communicates with the nozzle opening and can store a liquid, and a pressure generation unit that changes the pressure of the liquid in the pressure generation chamber to discharge a liquid droplet from the nozzle opening. And
The flushing means has a flushing drive means for driving the pressure generating means,
The pressure generating means has a piezoelectric member that deforms the pressure generating chamber to discharge liquid droplets from the nozzle openings,
The control device is configured to supply a first drive signal to the piezoelectric member in a first flushing mode as a flushing drive means, and to supply a second drive signal to the piezoelectric member in a second flushing mode. To supply,
19. The first drive signal and the second drive signal are formed by selectively using a partial waveform of the common drive signal, according to any one of claims 15 to 18. Control device. The first drive signal is
A first voltage raising unit for supplying a voltage to the piezoelectric member so as to expand the pressure generating chamber and depressurize the inside;
A first voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the reduced pressure state;
A first voltage drop unit for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to a slightly reduced pressure state;
A second voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the mild decompression state;
A second voltage drop unit for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to the original state;
Have
The second drive signal is
A first voltage raising unit for supplying a voltage to the piezoelectric member so as to expand the pressure generating chamber and depressurize the inside;
A first voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the reduced pressure state;
A first voltage drop unit for supplying a voltage to the piezoelectric member so as to contract the pressure generating chamber and pressurize the inside;
A second voltage maintaining unit that supplies the piezoelectric member with a voltage that maintains the pressurized state;
A second voltage raising section for supplying a voltage to the piezoelectric member so as to return the pressure generating chamber to the original state;
20. The control device according to claim 19, further comprising: A computer-readable recording medium having recorded thereon a program that is executed by a computer system including at least one computer and causes the computer system to realize the control device according to any one of claims 13 to 20. Instructions for controlling a second program running on a computer system including at least one computer,
21. A computer-readable recording medium having recorded thereon a program executed by the computer system to control the second program to cause the computer system to realize the control device according to any one of claims 13 to 20.   21. A program that is executed by a computer system including at least one computer to cause the computer system to implement the control device according to any one of claims 13 to 20. Instructions for controlling a second program running on a computer system including at least one computer,
21. A program that is executed by the computer system to control the second program to cause the computer system to implement the control device according to any one of claims 13 to 20.

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