JP2008114401A - Recording liquid delivery apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording liquid delivery apparatus suppressing a decrease in through-put on recording. <P>SOLUTION: A plurality of blocks are provided which have a nozzle for delivering a recording liquid and forming a line head by arranging a plurality of them at specified positions, at least one reserve block having the nozzle for delivering the recording liquid and which does not form the line head, and a moving means for simultaneously moving in one direction approximately intersecting at right angles to a carrying direction of a recording medium. (1) Among a plurality of the blocks, the block 340 whose nozzle is positioned to the outside of a recording region of the recording medium by moving is excluded from a plurality of the blocks forming the line head, and (2) the reserve block 310 is used as one of a plurality of the blocks forming the line head in place of the excluded block. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a recording liquid ejecting apparatus that has a line head in which nozzles are arranged over all sub-portions of a transported recording medium and ejects a recording liquid to the recording area to record an image.

  Conventionally, in order to increase the recording speed, a line-type inkjet recording apparatus that records an image or the like on a transported recording medium by ejecting ink from nozzles arranged over all the sub-portions of the recording medium has been recorded. It has been put into practical use as one of liquid ejection devices.

  By the way, in such an ink jet recording apparatus, while ink is ejected and recording is performed, the nozzle surface on which the nozzle is formed becomes dirty or the nozzle is clogged, so that the ink droplet is stabilized. There is a case where ink is not ejected or ink droplets are not ejected. For this reason, in an ordinary inkjet recording apparatus, the nozzles are cleaned so that ink droplets are stably ejected from the nozzles.

  For example, in Patent Document 1, a line head in which nozzles are arranged over the entire width of a recording medium is moved in the width direction of the recording medium, and the nozzles are cleaned by a cleaning unit provided at an outer position of the recording medium. Technology is disclosed. Further, Patent Document 2 discloses a line-type ink jet printer in which a detection unit for detecting a nozzle discharge failure is provided in a moving path along which the line head is moved to a maintenance unit that eliminates a nozzle discharge failure. ing.

JP 2005-74764 A Japanese Patent Laid-Open No. 2005-199658

  However, in the technique and printer disclosed in Patent Document 1 or Patent Document 2, when the nozzle cleaning process or the maintenance process is performed, the line head is moved from the position on the recording medium to the position where the cleaning unit or the maintenance unit is provided. Need to move. Therefore, it becomes impossible to perform recording on the recording medium during the period when the nozzle is cleaned or maintained. As a result, although the recording speed is increased by the line head to increase the recording throughput, the recording operation has to be interrupted when performing cleaning and maintenance, and the recording throughput decreases accordingly. is there.

  Further, in Patent Document 2, an inspection unit for inspecting nozzle ejection defects is further provided, and nozzle ejection defects are detected in the process of moving the line head in order to provide high-precision print quality.

  However, in this case, although the deterioration of the printing quality can be avoided, the interruption time of the recording operation becomes longer by the detection time for detecting the ejection failure, so that the throughput for recording is further reduced.

  SUMMARY An advantage of some aspects of the invention is that it provides a recording liquid ejecting apparatus capable of suppressing a decrease in throughput with respect to recording.

  In order to solve the above-described problems, the present invention has a line head in which nozzles are arranged over all the sub-portions of a conveyed recording medium, and discharges the recording liquid to the recording area to record an image. A plurality of nozzles for discharging the recording liquid, and a plurality of blocks for forming the line head by disposing a plurality of nozzles at predetermined positions, and a nozzle for discharging the recording liquid. And at least one spare block that does not form the line head, and a moving unit that simultaneously moves a plurality of blocks that form the line head in one direction substantially orthogonal to the conveyance direction of the recording medium. (1) Among the plurality of blocks, the block in which the nozzle is located outside the recording area of the recording medium by the movement is a plurality of blocks forming the line head. It is excluded from, (2) the spare block is used as a plurality of blocks forming the line head in place of the said excluded blocks, characterized in that.

  According to this configuration, when a plurality of divided blocks forming one line head are simultaneously moved in the width direction of the recording medium, the nozzle position is outside the recording area of the recording medium, that is, as a line head. The block that does not function is replaced with a spare block, and the replaced block functions as one of the blocks that form a new line head. Therefore, for example, if the spare block is a block in which the recording liquid from the nozzle is always stably ejected, the recording liquid is always stably ejected from the line head formed by the replaced block. Probability increases. As a result, the necessity of interrupting the recording operation and maintaining the entire line head is reduced, so that a decrease in throughput for recording can be suppressed.

  Here, the excluded block is one block located at the head in the one direction among the plurality of blocks forming the line head, and the spare block is a plurality of blocks forming the line head. It is preferable that the block is one block located at the end in the one direction.

  In this way, each time a plurality of blocks forming the line head move in one direction, one block is replaced with a spare block. As a result, a plurality of blocks forming the line head are sequentially replaced with spare blocks, so that the blocks forming the line head are not fixed. Therefore, if a block that can stably discharge recording liquid is used as a spare block, ink droplets are always stably discharged from a line head formed of a plurality of blocks. Therefore, in such a case, there is basically no need to interrupt the recording operation and maintain the entire line head, so that it is possible to suppress a decrease in throughput for recording.

  In addition, when the recording operation is interrupted during the movement period in which the plurality of blocks forming the line head are moved, the interruption time may basically be the movement time for one block. Obviously, it can be considerably shorter than the travel time of travel. As a result, the interruption time of the recording operation can be suppressed, so that a decrease in throughput with respect to recording can be suppressed.

  Here, the moving means may move a plurality of blocks forming the line head during recording of the image.

  Even if the plurality of blocks forming the line head are moved by one block in one direction, if the nozzle positions of the plurality of blocks are present in the recording area in the width direction of the recording medium, the block is being moved. Even so, recording on the recording medium can be performed. In other words, when the line head is formed in such a state by a plurality of blocks, the blocks can be moved during recording. Therefore, if the plurality of blocks forming the line head are moved during recording on the recording medium, the recording operation does not need to be interrupted even during the movement period in which the plurality of blocks forming the line head are moved. As a result, a decrease in throughput with respect to recording can be suppressed.

  The recording liquid ejection apparatus of the present invention further comprises ejection inspection means for inspecting whether or not the recording liquid is ejected from the nozzles with respect to the excluded block, and the preliminary block includes the ejection inspection means. It may be the excluded block that is inspected when the recording liquid is discharged from the nozzle.

  In this way, for the excluded block, the block that has been inspected and confirmed to eject the recording liquid from the nozzle is used as a spare block, so there is no need to prepare a plurality of spare blocks that stably eject the recording liquid. Good. As a result, for example, when a spare block is stored in the recording liquid discharge apparatus, the storage space can be reduced, so that an increase in the recording liquid discharge apparatus can be suppressed.

  Furthermore, the recording liquid ejection apparatus of the present invention includes a maintenance unit that performs a maintenance procedure so that the recording liquid can be ejected from the nozzle, and the spare block is configured to perform the maintenance procedure according to an inspection result of the ejection inspection unit. The excluded block may be the excluded block.

  In this way, for the excluded block, the block that has been inspected and confirmed not to eject the recording liquid from the nozzle is maintained so that the recording liquid can be discharged from the nozzle by the maintenance means, and the excluded block after the maintenance is completed. Use spare blocks. Therefore, a spare block that stably ejects the recording liquid can be covered by the excluded block. As a result, for example, when a spare block is stored in the recording liquid ejection apparatus, the number of spare blocks to be stored is small, so that the storage space can be further reduced, and the recording liquid ejection apparatus becomes larger. This can be suppressed.

  In addition, it is preferable that the plurality of blocks forming the line head and the spare block have recording liquid storage means for storing the recording liquid.

  By doing so, the recording liquid can be ejected from the nozzles alone without receiving the supply of the recording liquid from the outside. Therefore, when moving the block when forming the line head or excluding it from the block forming the line head, a supply path for supplying the recording liquid from the outside is formed, or supply of the block and the recording liquid is performed. There is no need to disconnect the road. As a result, it is possible to easily move and exclude blocks for each block.

  Further, the recording liquid discharge device may be a device that discharges a recording liquid by an ink jet method. In addition, the ejection method includes driving the piezoelectric element to eject the recording liquid from the nozzle, or heating the recording liquid by applying a voltage to a heating resistor (for example, a heater) and applying the recording liquid by the generated bubbles. The recording liquid may be discharged under pressure.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of an ink jet printer which is an embodiment of the recording liquid ejection apparatus of the present invention. This ink jet printer 10 constitutes a line head in which nozzles are arranged in the width direction of a printing paper that is substantially orthogonal to the conveyance direction of the printing paper as a recording medium, and ink as a recording liquid is supplied during the conveyance of the printing paper. This is a line-type inkjet printer that performs printing by discharging.

  As shown in FIG. 1, the ink jet printer 10 supplies a line head that discharges each color ink of Y (yellow), M (magenta), C (cyan), and K (black), and supplies, conveys, and discharges printing paper. And a discharge inspection unit and a discharge recovery unit (not shown) which will be described later.

  A paper feed tray 11 for storing printing paper 20 is provided at the lower part of the ink jet printer 10, and the stored printing paper 20 is taken out one by one by the take-out device 12, and then is fed to the transport path 21 by the transport rollers 13 a and 13 b. Sent out. Thereafter, the printing paper 20 is further taken out from the conveyance path 21 by the conveyance rollers 14a and 14b, and is placed on the conveyance belt 25 stretched by the tension roller 22a and the tension roller 22b by the pressing roller 15.

  The printing paper 20 placed on the transport belt 25 is transported from the right to the left in the drawing as the transport belt 25 moves. With respect to the printing paper 20 being transported, a predetermined position is sequentially set from a K line head 30, a C line head 40, an M line head 50, and a Y line head 60 at positions determined by image data to be printed. Color ink is ejected to print an image. Thereafter, the printing paper 20 on which the image has been printed is discharged to the discharge tray 18 by the discharge rollers 16a and 16b.

  Next, each line head 30, 40, 50, 60 will be described. In this embodiment, it is assumed that all the YMCK line heads have the same configuration, and the following description of the line heads will be made for the K (black) line head 30 as an example.

  FIG. 2 is a schematic diagram for explaining the configuration of the line head 30 and is a plan view showing the state of the line head 30 as viewed from above the ink jet printer 10 of FIG. For ease of explanation, a front view of the line head 30 is shown at the bottom of the drawing. As shown in the drawing, a total of four blocks for ejecting ink from the nozzles are arranged adjacently from block 310 to block 340. The left and right sides of each block are sandwiched between a substantially L-shaped guide rail 31 and a guide rail 32, and are configured to be movable along the guide rail 31 and the guide rail 32 without rattling in the left-right direction of the drawing. Has been. Further, the blocks are in contact with each other with no gaps at the ends in the vertical direction of the drawing.

  As moving means for moving each block, an actuator 35 and a push portion 36 that moves in the vertical direction of the drawing by the actuator 35 are provided at the lower end portion of the guide rail 31 (guide rail 32). Then, when the push portion 36 is driven by the actuator 35 to move in the moving direction S indicated by the arrow and moves to the position of the push portion 36b indicated by the two-dot chain line in the figure, each block from the block 310 to the block 340 is While moving in contact with each other, they move simultaneously by the length of one block in the upward direction of the drawing. Each block is moved one block at a time by repeating movement at a predetermined timing by the moving means configured as described above. From the end of the movement to the next movement, each block is configured so that an appropriate pressure is applied from the side by the guide rail 31 and the guide rail 32 so as not to move in the vertical direction of the drawing during image printing. .

  Here, the structure of each block 310,320,330,340 is demonstrated. Note that all the blocks have the same structure, and as an example, an outline of the structure of the block 310 will be described with reference to FIG.

  The block 310 includes a block main body 311 and an ink tank 313 as a storage means for storing ink. In the present embodiment, the ink tank 313 is provided integrally with the block main body 311 so that ink can be replenished from the ink supply port 313a. Of course, the ink tank 313 may be formed in a cartridge type and configured to be detachable from the block body 311.

  A nozzle 315 for ejecting ink is formed on the bottom surface of the block body 311. In the present embodiment, description will be made assuming that 180 nozzles are formed for one block. In FIG. 3 (and FIG. 2), the nozzles formed in each block are shown as four nozzles so that the drawing is not complicated. Of course, a larger number of nozzles is usually formed in many cases, for example, the number of nozzles corresponding to the number of pixels of an image to be printed is formed.

  Corresponding to each of the formed nozzles, a pressure generating mechanism (see FIG. 3, a blowing portion) that generates pressure to eject ink for each nozzle is formed in the block main body 311. That is, when a voltage is applied to the electrodes COM and GND at both ends of the piezoelectric element 2, the piezoelectric element 2 is deformed and driven to push down the member 3 in the direction of the arrow (the lower side in the drawing) and apply the ink 8 supplied from the ink tank 313. It is comprised so that it may press. As a result, ink is ejected as ink droplets 9 from the nozzles 315 provided on the bottom surface of the block main body 311. Therefore, an image is printed by selecting a nozzle in accordance with the position in the conveyance direction of the printing paper, and driving the piezoelectric element corresponding to the selected nozzle to be deformed and ejecting ink droplets from the nozzle.

  In order to print an image in this way, a receiving substrate 314 including a receiving circuit that receives a drive signal for selecting a nozzle to eject ink and deforming and driving a piezoelectric element is also provided in the block main body 311. ing. In the block main body 311, the drive signal received by the receiving circuit is applied to the COM electrode and the GND electrode of the corresponding piezoelectric element. In addition, in order to receive power supply for operating these receiving circuits, pressure generating mechanisms, etc., two conductive belt-like patterns 312a and 312b (see FIG. A terminal board 312 is provided. The conductive brush 318 a and the brush 318 b that are in contact with the pattern 312 a and the pattern 312 b are configured so that power can be supplied from the outside of the block 310.

  Returning to FIG. 2, in the state before the movement of each block, as shown in the figure, the nozzles (FIG. 2, broken line circles) are formed over the width WP in which the three blocks from block 320 to block 340 become the printing area of the printing paper 20. A line head for forming a mark) is formed. When each block forming the line head moves in the movement direction S by the movement of the pressing portion 36 in this way, the block 340 located at the head is pushed out of the printing area WP, and from the block forming the line head. It is an excluded block (hereinafter simply “excluded block”).

  On the other hand, the block 310 is a spare block for forming a line head before the movement of the block, and is located at the end in the movement direction S, and is moved to the position of the block 320 by the push portion 36. At this time, in the opening 32h provided on the side surface of the guide rail 32, the brush 318a and the brush 318b (not shown) described in FIG. 3 abut against the pattern 312a and the pattern 312b, respectively, so that power is supplied to the block 310. The In addition, in the opening 31 h provided on the side surface of the guide rail 31, the reception circuit provided on the reception board 314 described above receives a drive signal transmitted from a transmission circuit described later. Thus, it functions as one block forming the line head and prints an image on the printing paper 20.

  Of course, the block 320 is moved to the position of the block 330, and the block 330 is moved to the position of the block 340. And also about each block, similarly to the block 310, in the opening part 32h provided in the side surface of the guide rail 32, power is supplied from the brush which is not shown in figure. Moreover, in the opening part 31h provided in the side surface of the guide rail 31, the receiving circuit provided in the block receives the drive signal transmitted from the transmission circuit mentioned later. As a result, the block 340 forming the line head is replaced with the block 310.

  The exclusion block 340 excluded from the block forming the line head is then transported to a discharge inspection box 70 as discharge inspection means to inspect whether ink droplets are discharged from the nozzles, and further according to the result of the discharge inspection. Then, it is transported to a discharge recovery device 80 as maintenance means, and a predetermined discharge recovery treatment is performed. Then, the block 340 in which the ejection recovery has been performed is used as a spare block that becomes a block forming the line head. For this reason, after once transported to the storage area 90 for storing the spare block, it is transported and installed at the position of the block 310 described above when the next block is moved. The ejection inspection box 70, the ejection recovery device 80, and the storage area 90 are provided at predetermined locations (not shown) in the inkjet printer 10. Of course, these may be provided outside the inkjet printer 10.

  As is apparent from the above description, in this embodiment, every time the block is moved by the moving means, the blocks forming the line head are sequentially switched. Then, when one block is excluded from the blocks forming the line head, ink droplets are reliably discharged from the nozzles by performing discharge inspection and discharge recovery treatment corresponding to the discharge inspection result for the excluded block. This exclusion block can be used as a block for forming a line head. Further, since the block for performing the ejection inspection and the ejection recovery treatment is not the block for forming the line head, it is not necessary to interrupt the printing of the image for the ejection inspection and the ejection recovery treatment as in the conventional example. Therefore, it is possible to perform a printing process in which the throughput for recording is not reduced while avoiding the deterioration in printing quality.

  By the way, in the conventional example shown in Patent Document 1 or Patent Document 2 described above, since cleaning and maintenance are performed for the entire nozzle forming the line head, the provided cleaning means and maintenance means are the line head. It is disclosed as requiring approximately the same length as the whole. Therefore, an ink jet printer provided with such cleaning means and maintenance means cannot be made shorter than the sum of such means and the length of the line head in the width direction of the printing paper. This is a problem for downsizing

  On the other hand, in the present embodiment, as shown in FIG. 2, one block pushed out from the printing area WP is taken out from the line head as an excluded block, and then discharge inspection and discharge recovery processing are performed. Therefore, as long as the upper side of the print area WP in the drawing is sufficient, an area having a length WB of one block can be secured in the inkjet printer 10. On the other hand, on the lower side of the print area WP in the drawing, an area of the total length WA of one spare block for forming the line head and the actuator 35 and the push portion 36 provided as moving means is secured. It only has to be done. That is, the inkjet printer 10 according to the present embodiment can be downsized to a lateral width that can secure the length corresponding to the sum of WA, WP, and WB in the width direction of the printing paper 20. As a result, the probability that the lateral width of the ink jet printer can be further reduced is higher than in the case of moving the entire line head as in the conventional example, and this contributes to the miniaturization of the ink jet printer.

  Next, control of the above-described moving operation and the like performed in the inkjet printer 10 of the present embodiment will be described using the control circuit configuration diagram shown in FIG. Each control circuit shown in FIG. 4 is formed on a circuit board (not shown) provided in the inkjet printer 10 of FIG.

  The control circuit includes a CPU 100 for controlling various operations of the ink jet printer 10, a ROM 101 for recording programs relating to these operations, a RAM 102 for temporarily storing and reading data necessary for the operation, and a user And an interface (I / F) 105 for exchanging data with an external device such as a personal computer (PC) 109. Further, a nozzle drive control circuit 110 for discharging predetermined color ink from nozzles of each block forming the line head, a block movement control circuit 120 for controlling movement of each block by controlling the actuator 35, and each block are provided. Ink from the nozzles using the drive signal generation circuit 150 that generates a drive signal for driving the piezoelectric element corresponding to the nozzle, the discharge inspection control circuit 170 that controls the discharge inspection using the discharge inspection box 70, and the discharge recovery device 80 An ejection recovery control circuit 180 that controls recovery of droplet ejection and a printing paper conveyance control circuit 190 that controls conveyance of printing paper from ejection to ejection to a paper ejection tray are provided. These are connected by a bus line so that data can be exchanged between them.

  The CPU 100 generates a drive signal for driving the piezoelectric element corresponding to the nozzle by controlling the drive signal generation circuit 150 based on the print image data sent from the PC 109 via the I / F 105 and stored in the RAM 102. To do. Then, the printing paper conveyance control circuit 190 controls the printing paper conveyance means described in FIG. 1 to convey the printing paper, and the generated drive signal is sent to each line head via the nozzle driving control circuit 110. Transmission is performed to each block to be formed, and control is performed so that ink droplets of a predetermined color are ejected from a nozzle included in each block onto a print medium to print a print image.

  The nozzle drive control circuit 110 is basically formed in accordance with the number of line heads provided for each ink color. In this embodiment, the nozzle drive control circuit 110k corresponding to the K line head 30 is connected to the C line head 40. A corresponding nozzle drive control circuit 110c, a nozzle drive control circuit 110m corresponding to the M line head 50, and a nozzle drive control circuit 110y corresponding to the Y line head 60 are formed.

  These nozzle drive control circuits all have the same circuit configuration. For example, as shown in FIG. 4, when the block forming the line head includes three blocks 310, 320, and 330, the nozzle drive control circuit 110 k stores data corresponding to the width WP of the print area, The drive signal corresponding to each of the three blocks is divided by the interface (1 / F) 115, and the drive signal is wirelessly transmitted to each of the blocks 310, 320, and 330 via the transmission circuits 111, 112, and 113 corresponding to the three blocks. Send. The transmitted drive signal is received by the receiving boards 314, 324, and 334 in each block, and the piezoelectric element corresponding to the nozzle is driven by the received drive signal.

  Here, the drive signal will be described in detail with reference to FIG. The drive signal generation circuit 150 includes a total of four Pv and P1, P1, P2, and P3 in a section for printing an image corresponding to one pixel (also referred to as a segment when the printing paper 20 crosses one pixel interval). An original signal ODRV in which unit signals (pulse balloons in FIG. 5) having pulse signals are repeatedly present and a print signal PRTn are generated.

  The original signal ODRV includes a pulse signal Pv for causing the piezoelectric element to vibrate slightly so that the ink does not harden in the nozzle, and pulse signals P1, P2, for ejecting one ink drop from each nozzle. P3. The printing paper 20 has a small size dot only with the pulse signal P1, a medium size dot with the pulse signal P1 and the pulse signal P2, and a large size dot with the pulse signal P1, the pulse signal P2, and the pulse signal P3. Formed.

  The print signal PRTn (n = 1 to 540) is a signal that specifies a nozzle to which ink droplets should be ejected from among 540 nozzles and selects a pulse signal in the original signal ODRV for each block. Therefore, the print signal PRTn is a signal for selectively supplying the nozzles by selecting the nozzles that should eject ink and the pulse signals that should be output based on the print data (the presence or absence of dots and their gradation values) when printing is performed. Become. Further, at the time of an ejection inspection described later, a nozzle for ejecting ink for the inspection is specified and a pulse signal to be output is selected.

  These signals are output to the mask circuit. The mask circuit is configured so that a pulse signal selected by the print signal PRTn among the original signals is output to a piezoelectric element corresponding to the nozzle that is also specified by the print signal PRTn. That is, the mask circuit is configured to output the pulse signal selected by the print signal among the pulse signals of Pv, P1, P2, and P3 to the piezoelectric element corresponding to the selected nozzle, and is driven from the mask circuit. Output as signal DRVn. Thus, the drive signal DRVn is generated.

  The drive signal DRVn (n = 1 to 540) generated in this way is divided by the I / F 115 based on the number of blocks forming the line head. In this embodiment, since the number of blocks forming the line head is three, the drive signal DRVn is divided into three signals DRV1 to 180, DRV181 to 360, and DRV361 to 540. Further, in the I / F 115, the drive signal DRVn is converted into a data signal that can be wirelessly transmitted, and transmitted from the respective transmission circuits 111 to 113.

  The transmitted data signals are converted into reception and drive signals DRVn by the reception circuits 314, 324, and 334 of the respective blocks, and the piezoelectric elements corresponding to the nozzles of the respective blocks are driven. In the example shown in FIG. 5, the piezoelectric elements corresponding to the nozzles n = 1 to 180 of the block 310 are driven by the drive signals DRV1 to 180, respectively, and the piezoelectric elements corresponding to the nozzles n = 1 to 180 of the block 320 are The piezoelectric elements respectively driven by the drive signals DRV181 to 360 and corresponding to the nozzles n = 1 to 180 of the block 330 are driven by the drive signals DRV361 to 540, respectively. Thus, a print image is formed on the printing paper by the line head formed by the three blocks.

  In the present embodiment, the drive signal is transmitted to the block in a wireless manner as described above, but it is preferable to use a short-range communication means using radio waves such as UWB (Ultra Wide Band) as the communication means. In this way, the reception circuits of the corresponding blocks can stably receive the drive signal without causing signal interference between adjacent transmission circuits. Of course, wireless communication may be performed using infrared rays instead of radio waves. Or it is good also as transmitting a drive signal not by radio but by the wire by the brush and pattern as shown, for example in FIG.

  Next, operations performed in the inkjet printer 10 of the present embodiment will be described using the flowchart of FIG.

  When the operation of the inkjet printer 10, that is, printing is started, first, in step S101, printing processing is performed. The CPU 100 reads the print data stored in the RAM 102 and prints the print data on the print paper 20 by controlling the nozzle drive control circuit 110, the print paper transport control circuit 190, and the like.

  Next, in step S105, it is determined whether or not a predetermined amount of printing has been performed. In this embodiment, it is assumed that the number of print sheets is stored in advance in the ROM 101 as a predetermined amount. Therefore, the CPU 100 counts the number of printed sheets and makes a determination by comparing with the predetermined number of printed sheets stored in the ROM 101. Of course, the printing amount is not limited to the number of printed sheets, and may be, for example, a cumulative value of the printing time or a cumulative value of the number of times of driving each piezoelectric element.

  By the way, in this embodiment, since the line head is formed of three blocks, as is apparent from the above description, one block starts from the block that forms the line head when a predetermined amount of printing is performed three times. Will be excluded. Therefore, it is preferable to set the print amount that is one third of the print amount to be subjected to the nozzle ejection inspection as the predetermined print amount. Of course, as the number of blocks forming the line head increases, the predetermined printing amount decreases.

  As a result of the determination, if the predetermined amount of printing has not been reached (step S105: NO), it is determined whether or not the printing is finished in step S110. The CPU 100 determines whether there is print data that has not yet been printed. If print data exists (NO), the process returns to step S101 to continue printing. If print data does not exist (YES), printing ends.

  As a result of the determination, if a predetermined amount of printing has been reached (step S105: YES), whether or not a spare block that forms a line head when the block is moved has been installed on the guide rails 31 and 32 in step S106. It is determined whether or not. In FIG. 2, the CPU 100 detects the output of a sensor (not shown) that outputs a signal when the block is installed at the position of the block 310, and determines whether or not it has been installed.

  If there is no sensor output (NO), the process waits until an output is detected. After detecting the output (YES), the process proceeds to the next step S107. In the present embodiment, it is assumed that the user performs a process of installing a spare block at the tail end of the guide rail (step S116). Therefore, the user conveys and installs the spare block stored in the storage area 90 (FIG. 2) at the end of the guide rail until the predetermined amount of printing is completed.

  Next, in step S107, the actuator is operated to move each block by one block. The CPU 100 controls the block movement control circuit 120 to drive the actuator 35 and moves the push portion 36 to move each block installed on the guide rails 31 and 32 (FIG. 2) by one block.

  Thereafter, in step S108, notification processing that the block has moved is performed. In the present embodiment, the block movement control circuit 120 notifies that the movement for one block has been completed using notifying means (not shown) (for example, lighting of a lamp). The user recognizes this notification and performs a process of excluding the head block from the movement target (step S118). Specifically, the user manually removes the leading block from the guide rail. Therefore, the extracted block becomes an excluded block excluded from the blocks forming the line head.

  Next, after the notification by the notification means described above, the block movement control circuit 120 performs a process of operating the actuator and returning the pushing portion to the original position (step S109). By doing so, the above-described spare block can be installed before the next predetermined amount of printing. Then, the process returns to step S101, the process after the predetermined amount of printing is repeated, and when all the print data is printed, the process here ends.

  By the way, in the present embodiment, the excluded block is used as a spare block. That is, the ejection block is subjected to ejection inspection, and then ejection recovery processing is performed according to the result of ejection inspection, and a block where ink droplets are reliably ejected from the nozzle is used as a spare block. This will be described with reference to the flowchart of FIG.

  First, a discharge inspection process is performed. In step S201, it is determined whether there is a target block for discharge inspection. In FIG. 2, the CPU 100 detects the output of a sensor (not shown) that outputs a signal when a block is installed at the position of the ejection inspection box 70, and determines whether there is a target block. If there is no output from the sensor (NO), the process waits until an output is detected. After the output is detected (YES), a discharge inspection process is performed in the next step S202.

  Here, the mechanism of the ejection inspection apparatus incorporated in the inkjet printer 10 will be specifically described with reference to FIG. In the present embodiment, it is assumed that the ejection inspection is performed using a method for determining whether or not ink is ejected using a voltage change generated when a charged ink droplet is ejected from a nozzle. Of course, the method is not limited to such a method, and a known method such as a method of performing an ejection test using whether or not an ejected ink droplet blocks light may be used.

  FIG. 8 is a schematic diagram illustrating an apparatus configuration for applying pressure to ink from each of a plurality of nozzles provided in the block main body 311 and determining whether ink droplets are ejected, with the block 310 as an example. FIG.

  When the target block 310 of the discharge inspection is installed at the position of the discharge inspection box 70, the ground potential for operating the pressure generating mechanism or the like on the two conductive strip-shaped pattern portions provided on the terminal board 312 A voltage Vd with respect to the ground potential is supplied. Then, the CPU 100 generates a drive signal for selecting a nozzle to eject ink for ejection inspection and a deformation driving of the piezoelectric element in the drive signal generation circuit 150, and passes through the ejection inspection control circuit 170 and the transmission circuit 179. The data is transmitted to a receiving circuit formed on the receiving substrate 314. In this way, the nozzle to be inspected in the ejection inspection is selected, and the piezoelectric element is driven so that the ink supplied from the ink tank 313 to the block body 311 through the supply path (not shown) is ejected from the nozzle selected as the ink droplet 9. To do.

  The ejected ink droplet 9 is landed on the electrode member 71 provided in the ejection inspection box 70. The electrode member 71 is formed of a metal material such as a mesh-like SUS plate, and serves as a landing receiving area for the ink droplet 9. The landed ink droplet 9 then passes through the electrode member 71 and is absorbed by the ink absorber 72 formed of sponge-like resin or the like. Thus, the electrode member 71 is configured not to deposit ink. The electrode member 71 is electrically grounded by a connection member 176.

  In the discharge inspection, the discharge inspection control circuit 170 operates the voltage generation circuit 171 whose one end is grounded, generates a predetermined voltage with respect to the electrode member 71, and then passes through a resistor 174 having a predetermined resistance value. A predetermined inspection voltage is applied to a predetermined location (for example, near the nozzle) of the block main body 311 using the connecting member 175.

  In the present embodiment, the inspection voltage applied to the block body 311 is a positive potential with respect to the electrode member 71. Accordingly, a voltage is generated between the electrode member 71 and the electrode body 71 in the direction of application from the block body 311 side to the electrode member 71 side. As a result, the block main body 311 is positively charged and the electrode member 71 is negatively charged.

  When the ink droplet 9 is ejected from the nozzle provided in the block main body 311, the ink droplet 9 takes away the positive charge charged from the block main body 311. Then, a positive charge flows through the resistor 174 to replenish the lost positive charge. Therefore, a voltage drop occurs due to the positive charge flowing through the resistor 174 in this way, and the voltage of the block body 311 changes (decreases). Therefore, with respect to the voltage that changes in this way, the DC component is cut through the capacitor 178, and only the voltage change is taken out as an output signal having a plus or minus voltage amplitude.

  Thereafter, this output signal is input to the ejection inspection control circuit 170, amplified as necessary, and then the value of the voltage amplitude representing the amount of voltage change is compared with a threshold value to determine whether or not ink droplets are ejected from the nozzles. To do. Of course, in the present embodiment, it is determined that ejection is present if the negative voltage amplitude is greater than or equal to the threshold value, and that ejection is not present (also referred to as “non-ejection”) if the voltage amplitude is within the threshold value. The determination result of whether or not ink droplets are ejected is recorded in the RAM 102 for each nozzle by the CPU 100, and the ejection inspection is completed.

  Returning to FIG. 7, in the next step S205, it is determined whether or not there is a non-ejection nozzle. The CPU 100 refers to the determination result of the discharge inspection recorded in the RAM 102, and if there is even one non-discharge nozzle (YES), the CPU 100 performs notification processing of discharge recovery necessity (step S206). On the other hand, when there is no non-ejecting nozzle (NO), a notification process is performed to indicate that ejection recovery is unnecessary (step S207). For example, in FIG. 1, a message indicating “necessary” or “unnecessary” is displayed on a display unit of an operation panel (not shown) provided in the inkjet printer 10, or a lamp indicating “necessary” or “unnecessary” is turned on. Or notify the user to that effect. Thus, the discharge inspection process is completed.

  Thereafter, when the notification that the ejection recovery is unnecessary is confirmed, the user carries out the exclusion block subjected to the ejection inspection to the spare block position (FIG. 2, storage area 90) as shown in step S217. By this processing, the excluded block is used as a spare block.

  On the other hand, when the notification of the necessity of discharge recovery is confirmed, as shown in step S216, the user carries the excluded block subjected to the discharge inspection to the discharge recovery apparatus as a target block for discharge recovery treatment.

  Next, the discharge recovery process will be described. As shown in the lower part of FIG. 7, first, in step S301, it is determined whether or not there is a target block for discharge recovery treatment. In FIG. 2, the CPU 100 detects the output of a sensor (not shown) that outputs a signal when a block is installed at the position of the ejection recovery device 80, and determines whether there is a target block. If there is no output from the sensor (NO), the process waits until an output is detected. After the output is detected (YES), a discharge recovery process is performed in the next step S302.

  The discharge recovery device 80 basically has a known structure including a cap member that covers an ink droplet discharge port of a nozzle provided in the block body and a suction pump. In other words, a cap member made of rubber or the like covers the entire ink droplet discharge port, and the ink droplets are forced from the nozzles by the suction pump sucking the air inside the space formed after blocking and sealing with the outside air. To be sucked into. Ink sucked by the suction pump is discharged to a waste ink tank. In this way, the discharge recovery treatment is performed for the non-discharge nozzles. Of course, the present invention is not limited to the discharge recovery treatment by suction, and for example, flushing may be performed by discharging ink droplets and blowing off foreign matters adhering to the nozzle discharge port and the nozzle discharge surface. Wiping for removing ink droplets adhering to the surface may be performed to perform ejection recovery treatment. Note that the structure for such a discharge recovery procedure is well known in the prior art, and therefore the description thereof is omitted here.

  Next, in step S303, the end of the discharge recovery process is notified. For example, in FIG. 1, a message indicating “END” is displayed on a display unit of an operation panel (not shown) provided in the inkjet printer 10, or a lamp indicating “END” is turned on to notify the user. Notify that. Thus, the discharge recovery process ends.

  After confirming the completion of the discharge recovery process, the user carries the excluded block subjected to the discharge recovery process to the spare block position (FIG. 2, storage area 90) as shown in step S313. By this processing, the excluded block is used as a spare block.

  The present invention has been described using specific embodiments. However, the present invention is not limited to these embodiments, and can be implemented in various forms without departing from the spirit of the present invention. Of course you can. Hereinafter, a modification will be described.

(First modification)
In the above embodiment, the line head is formed by arranging the three blocks so as to be aligned in a line. However, the blocks are alternately arranged in a staggered manner at predetermined intervals in the conveyance direction and the width direction of the printing paper. Thus, a line head may be formed.

  When the line head is formed by arranging the blocks in a line, it is necessary to prevent the nozzle pitch from changing at the boundary between the blocks. For this reason, it is necessary to form the nozzle of the edge part of a block in the immediate vicinity of the external shape of a block main body, and the load from a manufacture surface is large. Therefore, the blocks are arranged in a staggered pattern. This makes it possible to easily form nozzles with equal pitches over the entire width of the printing paper, although the nozzle positions differ in the printing paper conveyance direction. Many printers in practical use are actually arranged in such a staggered manner. An example of this is shown in FIG.

  FIG. 9A shows a state before the pushing portion 36c is moved by the actuator 35a, and four blocks 310n, 320n, 330n, and 340n having the same shape are arranged along the guide rails 31a, 32a, and 33a. ing. As shown in the figure, in this state, the blocks forming the line head are three blocks 320n, 330n, and 340n, and the block 330n is staggered in the transport direction of the printing paper 20 (from right to left in the drawing). Become. The block 310n is a spare block.

  FIG. 9B shows a state in which the pushing portion 36c is moved to the position of the pushing portion 36d by the actuator 35a, and four blocks 310n, 320n, 330n, having the same shape along the guide rails 31a, 32a, and 33a. 340n shows a moved state. As shown in the figure, in this state, there are three blocks 310n, 320n, and 330n that form the line head, and this time, the block 310n and the block 330n are transport directions of the printing paper 20 (from right to left in the drawing). It becomes a staggered pattern. Note that the block 340n is an exclusion block, and after the discharge inspection process and the discharge recovery process are performed as in the above-described embodiment, as shown by a two-dot chain line, as a spare block, in the block moving direction. On the other hand, it is installed at the last position.

  By the way, as shown in FIG. 9A and FIG. 9B, the arrangement of each block differs with respect to the conveyance direction of the printing paper 20. That is, when the line head is formed by arranging the blocks in a zigzag manner in this way, there are two types of block arrangements when the blocks are moved one by one. Therefore, when ejecting ink droplets from the nozzles of each block onto the printing paper 20, the CPU 100 controls the output timing of the drive signal so that the ink droplets are ejected at a timing according to the arrangement of the two types of blocks. The print data can be printed correctly.

(Second modification)
In the above embodiment, the block forming the line head is moved by one block when a predetermined amount of printing is completed. However, the block may be gradually moved during printing. By doing so, it is not necessary to interrupt the recording operation even during a moving period in which a plurality of blocks forming the line head are moved by one block, so that it is possible to suppress a decrease in throughput with respect to recording. This modification will be described with reference to FIG.

  FIG. 10 is a schematic diagram showing a state in which four blocks 310, 320, 330, and 340 form a line head and an image is printed on the printing paper 20. In this modification, each block forming the line head is moved by one pitch of the nozzle every time ten printing sheets 20 are printed by operating the pressing portion 36 by the actuator 35. Therefore, since one block has 180 nozzles, when 1800 printing sheets 20 are printed, the block moves by one block. Incidentally, FIG. 10 shows a state in which the printing paper 20 is printing an image on the 901st printing paper 20.

  In the above embodiment, three blocks form a line head, but in this modification, four blocks 310, 320, 330, and 340 form a line head as shown in the figure. Accordingly, each of the blocks 310, 320, 330, and 340 is provided with four transmission circuits 111 to 114 that correspond one-to-one. For example, a driving signal corresponding to the nozzles of the block 310 is wirelessly transmitted from the transmission circuit 111. .

  The four transmission circuits are fixed to a fixed plate 39 provided so as to be movable in the vertical direction (arrow in the figure). The fixed plate 39 is connected to a pressing portion 38 driven by an actuator 37, and moves in the vertical direction of the drawing as the pressing portion 38 moves.

  The push unit 38 is controlled so as to move in synchronization with the push unit 36 when the fixed plate 39 is pushed to move upward in the drawing, and the four transmission circuits correspond to the movement positions with respect to the four blocks. Control is performed to transmit a drive signal. For example, in the state illustrated in FIG. 10, the transmission circuit 111 transmits the drive signals DRV 1 to 90 to the block 310. The transmission circuit 112 transmits drive signals DRV 91 to 270 to the block 320, and the transmission circuit 113 transmits drive signals DRV 271 to 450 to the block 330. Then, the transmission circuit 114 transmits drive signals DRV 451 to 540 to the block 340.

  In block 310, the received drive signals DRV1 to 90 are allocated from the nozzle n = 180 that is the tip in the moving direction of the block and assigned to the piezoelectric elements corresponding to the nozzles n = 91 to 180, respectively. On the other hand, in the block 340, the received drive signals DRV451 to 540 are allocated from the nozzle n = 1 which is the rear end in the moving direction of the block and assigned to the piezoelectric elements corresponding to the nozzles n = 1 to 90, respectively. Apply. In the blocks at both ends forming the line head, the drive signal is thus output to each nozzle.

  A drive signal is output to the piezoelectric element corresponding to the nozzle to be printed on the printing paper 20 in accordance with the position of each block thus moved, so that the nozzle positions of the plurality of blocks forming the line head are determined. As long as there is a print area in the width direction of the print paper 20, recording on the print paper 20 can be performed even while the block is moving.

  Thereafter, when each block completes the movement of one block, the actuator 37 immediately returns the pushing portion 38 to the original position before the movement of the block is started. Therefore, the fixing plate 39 moves downward in the drawing together with the pushing portion 38, and a transmission circuit for a total of four blocks including a newly installed spare block (block 310 shown in FIG. 2) and blocks 310, 320, and 330. Function as each. That is, the transmission circuit 112 transmits a drive signal to the block 310, the transmission circuit 113 transmits a drive signal to the block 320, and the transmission circuit 114 transmits a drive signal to the block 330. Needless to say, the period until the pressing portion 38 returns to the original position is a period during which printing should be interrupted.

  By repeating such control each time the blocks forming the line head are repeatedly moved, printing on the printing paper 20 can be performed even during the movement of the blocks.

(Other variations)
In the above embodiment, one block is moved among the plurality of blocks forming the line head. However, the present invention is not limited to this, and two or more blocks may be moved. When the number of blocks forming the line head is large, the discharge inspection is performed sequentially for each block as described above. Therefore, the interval of the discharge inspection for one block is set to a considerably long time according to the number of blocks. Will end up. Therefore, in such a case, for example, two blocks are moved at a time. In this way, it is possible to perform the ejection inspection at half the time interval as compared with the case of moving one block at a time.

  In the above embodiment, the number of blocks forming the line head has been described as three. However, the number of blocks is not limited to this. If the number of blocks is increased with respect to the length of the line head, the length per block becomes shorter. Therefore, as described in the above embodiment, with respect to the inkjet printer 10, the size of the printing paper in the width direction can be reduced by at least the block being shortened.

  Moreover, in the said embodiment, although the movement of a block was performed by the actuator and the pushing part, it is good also as not only using this but using other means, such as performing by a ball screw and a rotary motor, for example.

  Further, in the above embodiment, the user of the inkjet printer 10 is required to carry the excluded block to the discharge inspection box 70 and the discharge recovery device 80 and to carry the spare block to the block position which is the last of the line head. It was supposed to be done by work. Of course, for example, a well-known transport unit such as a transport robot may be provided in the inkjet printer 10 and the above-described transport installation work may be performed automatically. In this way, a space for installing the transportation means is required and the cost increases, but the user does not check the notification and does all the work automatically. It is possible to reduce the work load.

  In the above embodiment, an apparatus for ejecting ink droplets onto a printing medium by an ink jet printer has been described as one embodiment of the recording liquid ejection apparatus of the present invention. However, the present invention is not limited to this. It is. For example, an image, a figure, a character, etc. by ejecting a recording liquid using an inkjet method, such as a manufacturing apparatus for forming a wiring pattern by discharging a recording liquid onto a glass substrate or a resin substrate, or a manufacturing apparatus for a color filter The same can be applied to an apparatus for recording the image on a recording medium.

  In the above embodiment, the ink jet method using a piezoelectric element has been described as a method for discharging ink droplets. However, a so-called thermal ink jet method in which ink droplets are discharged using a heating element may be used. Of course, the present invention can be applied to any printer that uses a line head, such as a laser printer that forms a latent image from a line head using a laser beam.

1 is a schematic structural diagram of an inkjet printer according to an embodiment of the present invention. The schematic diagram for demonstrating the structure of a line head. The structure schematic of the block which forms a line head. FIG. 3 is a configuration diagram of a control circuit of the ink jet printer according to the embodiment. Explanatory drawing about the drive signal which drives a piezoelectric element. 6 is a flowchart showing an operation in the ink jet printer of the present embodiment. The flowchart which shows the process until an exclusion block is made into a reserve block. Explanatory drawing about the mechanism of the discharge inspection apparatus in this embodiment. (A), (b) is the structural example of the line head arrange | positioned in the zigzag form of the 1st modification. The schematic diagram which shows the state of the image printing by four blocks in the 2nd modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Piezoelectric element, 3 ... Member, 8 ... Ink, 9 ... Ink droplet, 10 ... Inkjet printer, 11 ... Feed tray, 12 ... Extraction device, 13a, 13b ... Conveyance roller, 14a, 14b ... Conveyance roller, 15 ... Pressure roller, 16a, 16b ... paper discharge roller, 18 ... paper discharge tray, 20 ... printing paper, 21 ... transport path, 22a, 22b ... tension roller, 25 ... transport belt, 30, 40, 50, 60 ... line head , 31, 31a ... guide rail, 31h ... opening, 32, 32a ... guide rail, 32h ... opening, 33a ... guide rail, 35, 35a ... actuator, 36, 36b, 36c, 36d ... pusher, 37 ... actuator , 38 ... pushing portion, 39 ... fixing plate, 70 ... discharge inspection box, 71 ... electrode member, 72 ... ink absorber, 80 ... discharge recovery device, 90 ... Pipe region, 100 ... CPU, 101 ... ROM, 102 ... RAM, 105 ... I / F, 109 ... PC, 110, 110k, 110c, 110m, 110y ... Nozzle drive control circuit, 111, 112, 113, 114 ... transmission circuit , 115 ... I / F, 120 ... block movement control circuit, 150 ... drive signal generation circuit, 170 ... discharge inspection control circuit, 171 ... voltage generation circuit, 174 ... resistance, 310, 320, 330, 340 ... block.

Claims (7)

A recording liquid ejecting apparatus that has a line head in which nozzles are arranged over all the sub-portions of a transported recording medium, and records an image by ejecting the recording liquid to the recording area,
A plurality of blocks having nozzles for discharging the recording liquid and forming the line head by arranging a plurality of nozzles at predetermined positions;
At least one spare block having a nozzle for discharging the recording liquid and not forming the line head;
Moving means for simultaneously moving a plurality of blocks forming the line head in one direction substantially orthogonal to the conveyance direction of the recording medium;
With
(1) Among the plurality of blocks, the block in which the nozzle is located outside the recording area of the recording medium by the movement is excluded from the plurality of blocks forming the line head,
(2) The spare block is used as a plurality of blocks forming the line head in place of the excluded block.
A recording liquid ejecting apparatus. The recording liquid ejecting apparatus according to claim 1,
The excluded block is one block located at the head in the one direction among a plurality of blocks forming the line head,
The recording liquid ejecting apparatus according to claim 1, wherein the spare block is one block located at the end of the one direction among the plurality of blocks forming the line head. The recording liquid ejection apparatus according to claim 1 or 2,
The recording liquid ejecting apparatus, wherein the moving unit moves a plurality of blocks forming the line head during recording of the image. The recording liquid ejection device according to any one of claims 1 to 3,
About the excluded block, comprising a discharge inspection means for inspecting whether or not the recording liquid is discharged from the nozzle,
The recording liquid ejection apparatus, wherein the preliminary block is the excluded block that is inspected when the ejection liquid is ejected from the nozzle by the ejection inspection unit. The recording liquid ejection apparatus according to claim 4,
Maintenance means for performing maintenance treatment so that the recording liquid can be discharged from the nozzle,
The recording liquid ejecting apparatus according to claim 1, wherein the spare block is the excluded block subjected to the maintenance treatment according to an inspection result of the ejection inspection unit. A recording liquid ejection apparatus according to any one of claims 1 to 5,
The recording liquid ejecting apparatus according to claim 1, wherein the plurality of blocks forming the line head and the spare block have recording liquid storage means for storing the recording liquid. A recording liquid ejection apparatus according to any one of claims 1 to 6,
The recording liquid ejecting apparatus is an apparatus for ejecting a recording liquid by an ink jet method.

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