JP2011037103A - Inkjet recording apparatus and recording method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce time in connection with maintenance time by efficiently carrying out maintenance of a recording head by the number of times as small as possible in an inkjet recording apparatus which continuously outputs a plurality of jobs, and to output an image by a suitable throughput. <P>SOLUTION: One job data is selected from a plurality of job data on the basis of priority information as an index of priorities for recording the job data. Then, it is determined whether or not to execute suction recovery before the selected job data is recorded on the basis of information related to an ink ejection number of times necessary for recording image data included in the job data. A job dispensing with suction recovery can be recorded with priority, and the number of times of the suction recovery operation can be reduced. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that employs an ink jet recording method in which ink is ejected from a recording head onto a recording medium, and a recording method thereof.

  An ink jet recording apparatus prints an image by ejecting ink from a plurality of nozzles provided in a recording head. In particular, in a large-format ink jet recording apparatus that has been increasing in recent years, a large-capacity ink tank fixed in the apparatus and a recording head that discharges ink while moving relative to the recording medium are connected by a resin tube. Forms are mainstream.

  The resin tube is required to be able to flexibly follow the movement of the recording head and at the same time to stably supply the ink consumed by the recording head from the ink tank. In order to be flexible to the extent that the operation of the recording head is not hindered, the rigidity of the tube must be low to some extent, and for that purpose, the molecular weight of the resin must be low. However, when a resin having a low molecular weight is used, gas permeability into the tube is also increased, so that air is easily mixed into the tube. The air mixed in the tube forms bubbles, travels toward the recording head as the ink is consumed, and eventually enters the recording head. As a result, ink is not normally ejected from the recording head, or an image defect such as missing dots is invited.

  Furthermore, when a relatively large bubble enters the recording head, the liquid chamber that supplies ink in common to the plurality of nozzles is blocked by the bubble, so that the ink cannot be retained due to the water head difference, and the tube The ink inside may flow backward in the direction of the ink tank. Such a phenomenon is generally referred to as “ink drop”, but when this “ink drop” occurs, many nozzles are idly driven, so the life of the print head is shortened or the print head is destroyed. I'll be there.

  In order to avoid such a situation, for example, Patent Document 1 discloses a suction recovery process for removing bubbles from the recording head by using a means (dot count) for counting the number of ejections from the recording head and a timer in combination. Has been disclosed in a suitable timing. Japanese Patent Application Laid-Open No. 2004-228688 discloses a configuration for determining the timing for executing the suction recovery process by combining the dot count and the recording duty of image data.

JP 07-125228 A JP 2001-121717 A

  By the way, there are usually the following three processes in the maintenance process of the recording head performed in order to maintain stable ejection. That is, a suction recovery process for sucking bubbles and foreign matters in the recording head from the discharge port, a preliminary discharge process for performing discharge unrelated to recording from each discharge port, and a wiping process for removing dirt on the discharge port surface . These generally cannot be performed simultaneously with the recording operation. Therefore, in the ink jet recording apparatus, in addition to the time required for the actual recording operation, the time required for the maintenance operation for normally executing the recording operation is also required. As a result, the total time of these operations is one job. It will be the consumption time involved.

  In particular, in a large format printing apparatus, since each recording scan is executed after data for one recording scan of the recording head is accumulated, a maintenance process may be required during the recording of the same image. Therefore, in a recording apparatus having such a configuration, maintenance processing is generally performed at the beginning of each recording scan in accordance with information obtained from a timer or dot count, that is, the recording history thus far. For this reason, there are many situations in which maintenance processing is performed even at a timing when it is not always necessary to remove bubbles, and the consumption time, that is, the throughput is reduced more than necessary.

  In particular, when a recording device that can be connected to a plurality of image input devices and outputs a plurality of images (a plurality of jobs) from various input devices continuously, the throughput is greatly reduced and a lot of time is required. There was a situation that was consumed more than necessary.

  The present invention has been made in view of such problems. Therefore, in the inkjet recording apparatus that outputs a plurality of jobs continuously, the purpose is to perform the recording head maintenance process as few times as possible, reduce the time related to the maintenance time, and image with a suitable throughput. Is to output.

  In order to solve the above problems, the present invention provides an ink jet recording apparatus that records an image on a recording medium while moving the recording head in a state where an ink tank and a recording head are connected via a supply tube. A suction recovery means for performing a suction recovery process capable of sucking air bubbles in the supply tube together with ink, image data, and the number of ejections of the recording head required to record the image data Storage means capable of storing a plurality of job data including information and priority information serving as a priority index for recording the image data, and the plurality of job data based on the priority information Selecting means for selecting one of the job data and the suction cycle before recording the job data selected by the selecting means. Based on the information related to the number of ejections, it is determined whether the execution of the process is necessary, and when it is determined that the suction recovery process is not necessary, the job data selected by the selection unit is And a confirming means for confirming as job data to be recorded next.

  Further, in an ink jet recording method for recording an image on a recording medium while moving the recording head in a state where an ink tank and a recording head are connected via a supply tube, bubbles in the supply tube are combined with ink to form the recording head. A step of performing a suction recovery process for suctioning through the image, image data, information on the number of ejections of the recording head required to record the image data, and a priority index for recording the image data A storage step of storing a plurality of job data including the priority information, a selection step of selecting one job data from the plurality of job data based on the priority information, and the selection step Whether or not it is necessary to execute the suction recovery process before recording the selected job data is indicated in the information regarding the number of ejections. A determination step for determining, a determination step for determining job data selected by the selection step as job data to be recorded next when it is determined that execution of the suction recovery process is not necessary, and And a step of recording an image on the recording medium using the recording head in accordance with the job data determined in the determination step.

  According to the present invention, it is possible to reduce the number of suction recovery operations by preferentially recording jobs that do not require suction recovery processing. As a result, it is possible to suppress the time and ink consumption associated with the suction recovery process and improve the running cost and time cost.

1 is an external view of an ink jet recording apparatus according to the present invention. FIG. 6 is a schematic diagram when the recording head is observed from a direction in which ink is ejected. It is a typical perspective view for demonstrating the structure of the nozzle row for 1 color. It is a figure for demonstrating the structure of the ink supply system employ | adopted by this invention. It is a typical perspective view for demonstrating the structure of the recovery system unit employ | adopted by this invention. It is a block diagram for demonstrating the structure of control of the recording device used by this invention. 6 is a flowchart for explaining each step of a recording head maintenance process. It is a flowchart for demonstrating each process of the recording processing sequence for 1 page. It is a flowchart for demonstrating each process of the recording sequence with respect to one job. It is a functional block diagram for explaining the means of image processing and the flow in a recording system composed of a host device and a recording device. 6 is a flowchart for explaining image processing steps for one job executed by the printer driver. 6 is a flowchart for explaining a process executed by a controller after receiving image data corresponding to one job. It is a flowchart for demonstrating the process which a controller judges and performs when performing the recording operation of several job data. FIG. 10 is a flowchart for explaining a process performed by a controller when a recording apparatus executes a recording operation of a plurality of job data.

    Hereinafter, the present invention will be described in detail with reference to the drawings.

(1) Mechanical Configuration of Inkjet Recording Apparatus (1-1) Outline of Apparatus FIG. 1 shows an appearance of an inkjet recording apparatus 200 according to an embodiment of the present invention. This is a so-called serial type recording apparatus, and forms an image by ejecting ink while moving the recording head (main scanning) in a direction (main scanning direction) orthogonal to the conveyance direction of the recording medium P.

  In the figure, the recording medium P is conveyed in the sub-scanning direction in the figure while being sandwiched between a paper feed roller and a pinch roller (not shown), and is arranged at a position where recording can be performed by the recording head 9 mounted on the carriage unit 2. The

  The carriage unit 2 reciprocates in the main scanning direction orthogonal to the sub-scanning direction while being guided and supported by the guide shaft 8 by a driving force obtained from a carriage motor (not shown) via a carriage belt. In the present embodiment, the carriage unit 2 is mounted with recording heads for six colors, and each of these recording heads has a supply tube 45 that can follow the scanning of the carriage unit 2 from an ink tank that accommodates each ink. Ink is supplied via

  The carriage unit 2 is electrically connected to the control circuit of the apparatus main body by a flexible cable 9 that can follow the scanning of the carriage unit 2, and receives a recording signal from the control circuit or receives information on the recording head from the control circuit. Can be sent. Furthermore, the carriage unit 2 is provided with an encoder sensor for reading the encoder 7 extending in the main scanning direction, and the current position of the carriage unit 2 can be acquired.

  Under such a configuration, the recording head 9 discharges ink supplied from the ink supply tube 45 based on the position information obtained by the encoder 7 and the recording data obtained from the flexible cable 9, thereby performing one batch. The recording scan is executed. When such a recording scan is completed, the recording medium P is conveyed in the sub-scanning direction by an amount corresponding to the recording width of the recording head. After that, when the print data for the next one scan is accumulated in the print buffer, the same print scan as described above is performed again. Images are recorded on the recording medium P step by step by alternately repeating the main recording scan and the conveying operation as described above. The area of the recording medium on which the recording for one scan is executed is supported from below by the platen 4 so that the distance between the ejection port surface of the recording head 9 and the recording medium is kept constant. .

  A recovery system unit for performing maintenance processing of the recording head 9 is provided at the end (home position) of the movable range of the carriage unit 2. In a rest state in which the recording operation is not performed, the carriage unit 2 stands by at the home position, and the ejection port surface of the recording head 9 is capped by a cap provided here.

  The transmission of the driving force from the carriage motor to the carriage unit 2 is not limited to the configuration using the carriage belt as described above. For example, other driving force transmission configurations such as a configuration in which the carriage unit 2 includes a lead screw that extends in the main scanning direction and is driven to rotate by a carriage motor, and an engaging portion that engages with a groove of the lead screw. It is also possible to adopt.

(1-2) Configuration of Recording Head FIG. 2 is a schematic diagram when the recording head 9 employed in the present embodiment is observed from the direction in which ink is ejected. In the recording head 9, six nozzle rows 11 to 16 for ejecting ink for six colors are arranged in parallel in the main scanning direction. In this embodiment, these six nozzle rows are black (BK), light cyan (Lc), cyan (C), light magenta (Lm), magenta (M), and yellow (Y) in order from the left in the figure. It is a nozzle row for discharging. The six introduction parts 23 are introduction ports for the recording head 9 to receive ink from the six ink tanks, and ink flow paths are formed from the introduction parts 23 of the respective colors to the respective nozzles. Each color introduction section 23 is connected to an ink tank for storing each color ink fixed inside the apparatus by a flexible tube.

  FIG. 3 is a schematic perspective view for explaining the structure of the nozzle row for one color employed in the present embodiment. The orifice plate 54 is formed with a plurality of ejection ports 55, an ink path 59 that guides ink to each ejection port 55, and an ink supply port 56 that supplies ink in common to these ink paths 59. The orifice plate 54 is bonded onto a substrate 51 having electrical wiring, and an electrothermal conversion element for generating thermal energy at positions corresponding to the individual ejection ports 55 and ink paths 59 on the substrate 51. 52 is deployed. Such an electrothermal conversion element 52, the ink path 59, and the ejection port 55 constitute one nozzle.

  When a voltage pulse is applied to the electrothermal conversion element 52 according to the recording signal, the electrothermal conversion element 52 rapidly generates heat, and film boiling occurs in the ink in the ink path that contacts the electrothermal conversion element 52. Then, the ink in the ink path is pushed out from the ejection port 55 by the bubble growth energy generated here and ejected as droplets.

  In the nozzle row of this embodiment, one row in which the plurality of nozzles are arranged in the sub-scanning direction at a predetermined pitch is configured in parallel with two rows in a state shifted by a half pitch in the sub-scanning direction. The predetermined pitch may be a pitch that is ½ of the recording resolution, and can be set to the same recording resolution or different recording resolution for each of the nozzle rows 11 to 16 of each color. For example, in the nozzle array 11 for BK, 640 nozzles are arranged at a recording resolution of about 245 / cm, and in the nozzle arrays 11 to 15 for other color inks, 1280 nozzles are about 490 / cm. It is also possible to have a configuration in which the recording resolution is arranged.

  In the above description, the electrothermal conversion element 52 is disposed so as to face the ejection port 55. However, the electrothermal conversion element is disposed on the side surface of the ink path, and the ink is ejected from the side surface in the direction in which the ink is ejected. It is good also as a structure which emits a bubble in a road.

(1-3) Ink Supply System FIG. 4 is a diagram for explaining the configuration of the ink supply system employed in this embodiment. The inlet 23 of the recording head 9 mounted on the carriage 2 is connected to the ink outlet tube 46A of the joint portion 46, and the joint portion 46 reciprocates in the main scanning direction together with the carriage 2. On the opposite side of the joint portion 46 from the ink outlet tube 46A, a connection portion 46B connected to the supply tube 45 of each color is provided for each ink color. The other end of the supply tube 46 is connected to an ink tank 39 disposed at a fixed portion of the recording apparatus, and ink is intermittently transferred from the ink tank to the recording head 9 according to consumption of ink accompanying recording. Can be supplied.

  The supply tube 45 has flexibility that can follow the movement of the carriage unit 2 or the recording head 9, and is a flexible resin tube. In the resin tube, the rigidity of the tube is determined by the molecular weight of the resin. Here, a material having a rigidity (molecular weight) that does not hinder the movement of the recording head 9 is used.

  In this embodiment, the ink tank 39 is prepared for six colors of black (39BK), light cyan (39Lc), cyan (39C), light magenta (39Lm), magenta (39M), and yellow (39Y). The ink tank of the present embodiment is molded by injection blow or the like using a resin such as PP or PE, and is assembled using techniques such as ultrasonic welding, thermal welding, adhesion, and fitting.

  In this example, the tank exterior is of a type that functions as an ink chamber as it is, and two joint rubbers 44 are provided at the bottom of each ink tank 39. A hollow needle 43 provided at the end of the supply tube 45 passes through one joint rubber 44 so that the ink in the ink chamber can flow out to the supply tube 45. A hollow needle 42 provided in the atmosphere communication pipe 41 passes through the other joint rubber 44, and the air for the ink that has flowed out of the ink tank 39 flows into the joint rubber 44 so that the internal pressure in the ink tank 39 is substantially constant. I try to keep it.

  Further, a buffer chamber 40 is inserted in the atmosphere communication pipe 41, and even if a pressure change occurs in the ink tank due to an environmental change or the like, the pressure change is absorbed and absorbed in the supply tube 45 and the recording head 9 side. To prevent the influence of. For example, even if the air in the ink tank expands, the internal pressure of the entire ink supply system can be kept constant by the buffer chamber 40 temporarily holding ink overflowing from the ink tank.

  In the recording head 9, ink is guided to the vicinity of the ejection opening by the capillary force of each ink path 59, while a meniscus is formed at the tip of the ink path by the negative pressure generated on the ink tank side. Such a negative pressure is generated by a water head difference between the ink path 59 and the meniscus formed at the opening of the hollow needle 42 connected to the atmosphere communication pipe. For example, in this embodiment, this negative pressure is set to approximately −90 mmAq.

  The configuration of the ink tank is not limited to the configuration described above. For example, one with an ink bag filled with ink inside, or a porous material filled inside to hold the ink impregnated and generate negative pressure to hold the ink meniscus formed at the ink discharge port of the recording head It is also possible to make it. Further, as a form of the tank having such a negative pressure generating mechanism, a flexible bag for storing ink is provided, and the inner volume of the bag is expanded by a spring mechanism or the like provided inside or outside the bag. It may be one that is energized.

(1-4) Recovery System Unit The carriage unit 2 is positioned at the home position as necessary during standby or during recording, and undergoes maintenance processing by the recovery system unit 20 here.

  FIG. 5 is a schematic perspective view for explaining the configuration of the recovery system unit 20 employed in the present embodiment. The cap 27 is supported by an elevating mechanism (not shown) so as to be able to move up and down. In the raised position, the cap 27 covers and protects the face surface on which the ejection ports of the recording head 9 waiting at the home position are arranged. In this embodiment, two caps 27 are prepared: a cap that collectively protects the face surfaces of black, light cyan, and cyan, and a cap that collectively protects the face surfaces of light magenta, magenta, and yellow. .

  During the recording operation, the cap 27 is disposed at the lowered position so as not to contact the moving recording head, but the recording head 9 is appropriately moved to a position facing the cap 27 and performs a preliminary ejection operation toward the cap 27. I can do it.

  In a state where the cap 27 has capped the face surface of the recording head 9, a negative pressure is generated in the cap 27 by using the suction pump 29, thereby forcibly removing bubbles and foreign matters together with ink from the ejection port of the recording head 9. The suction recovery operation can be performed. Further, in a state where the ink is not sufficiently filled up to the tip of the ejection port, the ink can be drawn from the ink tank to the tip of the ejection port.

  The suction pump 29 of the present embodiment has a tube pump configuration, a member having a curved surface along which the flexible tube 28 is formed, a roller 30 that can press the flexible tube 28 toward the member, The roller support part 31 rotates while supporting the roller 30. Then, by rotating the roller support portion 31 in a predetermined direction, the roller 30 rolls while crushing the flexible tube on the member, and generates a negative pressure in the sealed space formed by the cap 27. . The ink drawn into the cap 27 by the suction pump 29 is then transferred to a waste ink absorber installed in the apparatus.

  The suction pump 29 can be operated to discharge the ink received in the cap 27 by the preliminary discharge operation described above. That is, the ink held in the cap 27 is discarded via the flexible tube 28 by operating the suction pump 29 when the pre-discharged ink held in the cap 27 reaches a predetermined amount. It can be transferred to an ink absorber.

  Wiper blades 21 and 22 made of an elastic member such as rubber are fixed to a wiper holder 25. The wiper holder 25 is movable along the guide 24 in the front-rear direction of the figure indicated by the arrow (the direction in which the discharge ports are arranged in the nozzle row). When the recording head 9 is at the home position, by moving the wiper holder 25 in the direction of the arrow, it is possible to wipe out ink adhering thereto while the wiper blades 21 and 22 are in contact with the face surface. This operation is a wiping operation.

  The wiper blade 21 of the present embodiment is provided with two blades that wipe the black, light cyan, and cyan face surfaces together and one that wipes the light magenta, magenta, and yellow face surfaces together. On the other hand, the wiper blade 22 is a single blade that wipes the face surfaces of all colors together.

(2) Ink The ink that can be used in the recording apparatus of the present embodiment is not particularly limited. It may be an ink containing a dye component in the color material or an ink containing a pigment component. Further, the dye and the pigment may be different depending on the ink color, or an ink containing both components of the dye and the pigment may be used.

  As dyes that can be used, various dyes conventionally known in the art can be used. For example, an azo dye as a direct dye, a phthalocyanine dye, an azo dye as an acid dye, an anthraquinone dye, and the like can be given.

  Moreover, when using a pigment, all the conventionally well-known organic and inorganic pigments can be used. The water-soluble resin (dispersion resin) contained for dispersing the pigment in the ink is preferably soluble in an aqueous solution in which an amine or a base is dissolved and has a weight average molecular weight in the range of 3000 to 30000. Further, a range of 5000 to 15000 is preferable. For example, a styrene-acrylic acid copolymer, a styrene-acrylic acid-alkyl acrylate copolymer, a styrene-maleic acid copolymer, or a styrene-maleic acid-acrylic acid alkyl ester copolymer can be used. Moreover, a styrene-methacrylic acid copolymer can be used. Moreover, a styrene-methacrylic acid-acrylic acid alkyl ester copolymer and a styrene-maleic acid half ester copolymer can be used. Furthermore, a vinyl naphthalene-acrylic acid copolymer, a vinyl naphthalene-maleic acid copolymer, and a styrene-maleic anhydride-maleic acid half ester copolymer can be used. Furthermore, these salts can also be used.

  When an ink using a pigment component and a dye component together is used, it is generally desirable that the pigment: dye (weight ratio) is in the range of 8: 2 to 2: 8. More preferably, the range is 7: 3 to 3: 7 (pigment: dye).

(3) Configuration Example of Control System FIG. 6 is a block diagram for explaining a control configuration of the recording apparatus 200 used in the present embodiment. Reference numeral 101 denotes a programmable peripheral interface (hereinafter referred to as PPI). The PPI 101 receives a recording information signal including a command and recording data sent from the host device 100 connected to the outside and transfers it to the controller 102. Provide status information. The PPI 101 also inputs and outputs to and from the console 106 having a setting input unit for the user to make various settings for the recording apparatus, a display unit for displaying messages to the user, and the like. Further, the PPI 101 receives a signal input from a sensor group 107 including a home position sensor that detects that the carriage unit 2 is at the home position, a capping sensor, and the like.

  The controller 102 controls each mechanism in the recording apparatus according to a control program stored in the control ROM 105. In addition to the control program, the control ROM 105 also stores fixed data corresponding to data used in the control process (for example, data for determining the necessity of wiping execution according to the main part of the present embodiment). ing.

  The DRAM 103 is used to temporarily store received signals, use it as a work area for the controller 102, and store various data. The font generation ROM 104 stores pattern information such as characters and records corresponding to the code information, and outputs various pattern information corresponding to the input code information. The print buffer 121 is a memory for storing recording data expanded in the DRAM 103 and the like, and has a capacity for a plurality of recording scans by the recording head. A hard disk (HDD) 1205 is a memory for storing a plurality of job data including recording data and recording mode information. A method of using the hard disk 1205 will be described in detail later. The printer engine 1310 is an engine for controlling various drivers such as the carriage unit 2, the recording head 9, the recovery system, and the transport system. These units shown in FIG. 6 are controlled by the controller 102 via an address bus 117 and a data bus 118.

  The capping motor 113 is a motor that is a driving source for raising and lowering the cap 27, moving the wiper holder 25, and the operation of the suction pump 29. Motor drivers 114, 115, and 116 are drivers for driving the capping motor 113, the carriage motor 3, and the paper feed motor 5, respectively, according to the control of the MPU 102, and the head driver 111 is a driver for driving the recording head 9. It is.

  The sheet sensor 109 is a sensor for detecting whether the recording medium fed by the paper feed motor 5 has reached a position where recording by the recording head is possible. The power supply unit 120 includes an AC adapter and a battery as a drive power supply device, and supplies power to the above-described units.

  Here, the recording apparatus 200 according to the present embodiment is illustrated as connected to one host apparatus 100, but the recording apparatus according to the present embodiment can also connect a plurality of external devices serving as image input apparatuses. is there. A command and recording data can be received from each of the plurality of external devices.

  In a recording system including the recording device 200 and an external device (here, the host device 100) that supplies a recording information signal thereto, recording data is transmitted from the host device 100 via a parallel port, an infrared port, a network, or the like. . At this time, necessary information related to the recording operation such as the type of the recording medium, the size of the recording medium, the recording quality, the paper feed path, and whether or not the object is automatically discriminated is added to the head portion of the recording data. In addition, in the case of a configuration in which a treatment liquid for improving the fixability of ink on a recording medium is applied, information for determining the presence or absence of the application may be transmitted as information.

  In accordance with these commands, the controller 102 reads data necessary for recording from the ROM 105, and executes a recording operation based on these data. The data read from the ROM 105 at this time includes, for example, data for determining the number of printing passes when performing multi-pass printing, the ink ejection amount per printing medium unit area, the printing direction, and the like. In addition, the type of data thinning mask applied when performing multi-pass printing, the driving conditions of the recording head (for example, the shape of the driving pulse applied to the heat generating portion 52, the application time, etc.), the dot size, and the recording medium There are also conveyance conditions, carriage speed, and the like.

  FIG. 10 is a functional block diagram for explaining the image processing means and its flow in the recording system constituted by the host device 100 and the recording device 200 of the present embodiment.

  In the present embodiment, the host apparatus 100 includes an application 1301 and a printer driver 1303 as software that functions here. The application 1301 is software for creating or editing a sentence or a figure. The created image data such as a sentence or a figure has 8 bits (256) for each color of red (R), green (G), and blue (B). Data). The printer driver 1303 performs image processing for matching with the recording apparatus 200 on the RGB data created by the application 1301, and then transfers the processed RGB data to the recording apparatus.

  FIG. 11 is a flowchart for explaining image processing steps for one job executed by the printer driver 1303 of this embodiment. First, in step S401, the printer driver 1303 performs data conversion for mapping 8-bit data of each color of R, G, and B into a color space that can be reproduced by the printing apparatus. Specifically, using a three-dimensional LUT table prepared in advance, 8-bit data for each color of R, G, B is converted to 8-bit (or 10-bit) data for each color of R ′, G ′, B ′. Convert to

  In the subsequent step S402, recording mode information designated by the user and a predetermined color conversion table used in the designated recording mode are added to the R′G′B ′ data acquired in step S401. Here, the recording mode information designated by the user indicates, for example, a high speed mode, a normal mode, a high image quality mode, and the like, and these are designated via the user interface of the printer driver.

  In step S403, priority information of the job being processed is added, and the job is transferred to the recording apparatus 200 in this state. This priority information is information that serves as an index of how preferentially the current job being processed should be recorded among other jobs, and may be specified by the user. It may be automatically determined from the recording mode. Note that the processes in steps S401 to S403 are not limited to the order described above. For example, signal value conversion as described in step S401 may be performed after priority order information or a recording mode is given.

  FIG. 12 is a flowchart for explaining the processing steps executed by the controller 102 of the recording apparatus 200 after receiving the image data corresponding to the one job, with reference to the block diagram of FIG. In step S <b> 501, the image data output from the host device 100 is received by an external interface (I / F) block in the controller 102 and stored in the DRAM 103.

  In subsequent steps S <b> 502 to S <b> 504, the image controller 1397 performs predetermined image processing on the image data stored in the DRAM 103 to generate binary data that can be recorded by the recording head 9. Hereinafter, steps S502 to S504 will be specifically described.

  First, in step S502, the image controller 1397 performs color conversion processing on the received R′G′B ′ data using the color conversion table received together with these data. The color conversion process is a process for converting R′G′B ′ data into density data corresponding to the ink color used in the printing apparatus. Specifically, 8-bit R′G′B ′ data is converted into C (cyan), Lc (light cyan), M (magenta), Lm (light magenta), Y (yellow), and BK (black) colors. Convert to corresponding 8-bit density data. Note that the color conversion table used here is the three-dimensional lookup table (LUT) assigned according to the recording mode in step S402 described in FIG. 11, but all R′G′B ′ values are used. The CLcMLmYK value may not be prepared corresponding to the combination. CLcMLmYK values corresponding to some combinations of R′G′B ′ values are prepared, and for other combinations, output values may be acquired by performing interpolation processing from a plurality of the CLcMLmYK values.

  When the color conversion process ends, the image controller 1397 performs output γ correction on the density data of the six colors obtained in step S502. The output γ correction is a process for correcting the input density signal value and the density value expressed by the recording medium so as to have a linear relationship. In the present embodiment, 8-bit density data for each color is also corrected to 8-bit density data using a one-dimensional LUT.

  In subsequent step S504, the image controller 1397 executes quantization processing, and can record 8-bit multi-value density data with the recording head 9, that is, recording (1) or non-recording on individual pixels of the recording medium. It is converted into 1-bit binary data indicating recording (0). As the quantization processing method, a known error diffusion method can be used, but other quantization methods such as a dither method may be adopted.

  In the above image processing, the present embodiment has been described with the configuration in which the color conversion processing table executed in step S502 is acquired from the printer driver 1303. This is because the three-dimensional LUT used in the color conversion process generally differs depending on the type of recording medium, and is obtained from the printer driver 1303 for each job and expanded in the DRAM 204 rather than being stored in the recording apparatus. This is because the memory can be reduced. However, the present embodiment is not limited to such a configuration. A color conversion table corresponding to a plurality of recording media and a one-dimensional table for output γ correction may be stored in advance in the control ROM 105 of the recording apparatus 200.

  In subsequent step S505, the image controller 1397 uses the control block 1308 to count the number of data (1) indicating ink ejection (dot recording) among the binary image data. In short, so-called dot counting is performed. The obtained count value (information relating to the number of ejections) is stored in the hard disk (HDD) 1205 as one job data together with the recording mode information, priority information, and binary data (step S506). As will be described in detail later, these pieces of information are used when determining the recording order of a plurality of jobs. Thus, a series of image processing for one job as described with reference to FIGS. 11 and 12 is completed.

  The HDD 1205 in this embodiment can store a plurality of such job data, that is, job data associated with recording mode information and priority information together with binary recording data. Then, the image controller 1397 is configured to transmit to the engine controller 1309 one by one in accordance with the priority information of each job.

  Upon receiving the above information, the engine controller 1309 provides the information to the printer engine 1310 that controls various drivers such as the carriage unit 2, the recording head 9, the recovery system, and the transport system of the recording apparatus 200, and starts operation. .

(4) Control Procedure In this embodiment, the recording apparatus control method in the case of handling a plurality of job data as described above has its characteristics. Here, first, the recording of this embodiment having the above-described configuration is provided. A basic sequence in the apparatus 200 will be described.

(4-1) Recovery Processing Sequence FIG. 7 is a flowchart for explaining each step of maintenance processing of the recording head 9 executed under the control of the controller 102.

  When this process is started, the controller 102 first obtains the current time Ta from, for example, a calendar function provided in the main body in step S1, and then executes the previous maintenance process stored in the DRAM 103 in step S2. Read time Tb. Thereafter, in step S3, the difference between them, that is, the elapsed time T = Ta−Tb from the previous maintenance process to the present time is calculated.

  In step S4, it is determined whether or not the elapsed time T obtained in step S3 exceeds a predetermined threshold value U. If T ≦ U, it is determined that there is no need for maintenance processing at the present time, and the process jumps to step 7 to enter a standby state. On the other hand, if T> U, the process proceeds to step S5 to cause the printer engine 1310 to execute a predetermined maintenance process.

  When the maintenance process is completed, Tb is replaced with the value of Ta in step S6 and stored in the memory, and the process proceeds to step S7 and enters a standby state. If this standby state continues to some extent, the controller 102 moves the carriage unit 2 to the home position, and waits for the next command with the cap 27 covering the face surface of the recording head.

  Incidentally, the maintenance process described above generally includes a suction recovery process, a wiping process, and a preliminary discharge process, and all these processes are performed in step S5. However, even if T ≦ U in step S4, only the wiping process and the preliminary ejection process may be performed. Further, a plurality of different threshold values U are prepared, and according to the determination in step S4, the process of performing only preliminary ejection, the process of performing wiping and preliminary ejection, and the process of performing all of suction recovery, wiping and preliminary ejection are classified. The structure to perform may be sufficient.

  In order to determine an appropriate maintenance time, a timer such as a programmable interval timer (PIT) may be provided in the main body. The maintenance process may be performed using the full count from the timer as a trigger, and the timer may be reset / restarted after processing interference.

(4-2) Recording Processing Sequence FIG. 8 is a flowchart for explaining each step of the recording processing sequence for one page executed under the control of the controller 102.

  When the recording start command is input, the controller 102 first determines whether or not the recording head 9 is released from the cap using the cap sensor in the sensor group 10 (step S9). If it is determined that it is open, the process proceeds directly to step S11. On the other hand, if it is determined that the cap is not open, i.e., capped, the cap is opened in step S10, and the process proceeds to step S11.

  In step S11, a maintenance sequence before recording is executed according to the flowchart described with reference to FIG. 7, and in step S12, the sheet feeding motor 5 is driven via the printer engine 1310 to feed the recording medium. Align.

  In step S13, it is determined whether print data for one scan is accumulated in the print buffer 121 (data to be recorded still remains). If accumulated, the process proceeds to step S14. On the other hand, if it is determined that the recording data for the next one scan is not accumulated, the process proceeds to step S18.

  In step S14, it is determined again whether the recording head 9 is released from the cap. If it is determined that it is open, the process proceeds to step S16 as it is and a preliminary discharge operation is executed. If it is determined that capping is performed, the cap is opened in step S15, and then a preliminary ejection operation is performed in step S16.

  In step S17, a printing operation for one scan is executed. Thereafter, in step S18, it is determined whether or not to discharge (discharge) the recording medium in accordance with the end of the recording data for one page of the recording medium or a discharge command. If it is determined that the recording medium is to be discharged, the process proceeds to step S22 to execute a paper discharge operation. On the other hand, if it is determined that the paper discharge operation should not be performed yet, the process proceeds to step S19.

  In step S19, an accumulation standby time Tw of recording data required for the immediately preceding one recording scan is acquired. For this acquisition, for example, a timer used to measure the elapsed time for the above-described maintenance process may be used, and the elapsed time from the timing when a negative determination is first made in step S13 in each scan is measured. Can be obtained.

  In step S20, it is determined whether or not the standby time Tw exceeds the threshold value Tcap for capping. If Tw> Tcap, the capping operation for the recording head 9 is executed in step S21, and the process returns to step S13. . On the other hand, if Tw ≦ Tcap, the process proceeds to step S22.

  In step S22, it is determined whether or not the standby time Tw exceeds a threshold Tpre (<Tcap) for preliminary ejection. If Tw> Tpre, preliminary ejection is executed in step S23, and then the process proceeds to step S13. Return. On the other hand, if Tw ≦ Tpre, the process directly returns to step S13 without performing any maintenance operation.

  In the above procedure, preliminary ejection is performed every time in step S16 immediately before the start of each scan. However, the elapsed time since the previous preliminary ejection is managed by the timer in the same manner as described above, and the preliminary ejection is executed. The necessity may be determined.

  Further, in the preliminary discharge performed between the opening of the cap and the start of recording, a uniform number of discharges may be performed on the previous discharge port, or the number of discharges determined by the elapsed time or the like May be performed. Further, preliminary ejection conditions such as the number and execution timing may be set for each nozzle row of each color. Further, particularly, the preliminary ejection performed during recording may be performed only for nozzles that have not been used until the previous recording scan, or may be performed for all nozzles including the used nozzles. For the used nozzles, the number of discharges may be adjusted based on the frequency of use. In addition to the preliminary ejection, as described above, there are those in which the recording head is moved to the position of the cap and the ejection operation is performed to the extent that the portion on the recording medium is not noticeable while performing the recording operation.

(4-3) Recording Sequence in One Job FIG. 9 is a flowchart for explaining each step of the recording sequence for one job including the recording sequence for one page described in FIG. is there. When this process is started and the recording sequence for one page described with reference to FIG. 8 is completed in step S23, the controller 102 turns ON / OFF a wipe flag (described later) that specifies whether or not to perform wiping in step S24. Confirm. If the wipe flag is OFF, the process proceeds to step S27 as it is. On the other hand, if the wipe flag is on (set state), the process proceeds to step S25, and wiping is performed via the printer engine 1310 to reset the wipe flag, and then the process proceeds to step S27.

  In step S27, it is determined whether or not the next page to be recorded is accumulated in the print buffer in this job. If it is determined that pages to be recorded are accumulated, the process returns to step S23 to execute a recording sequence for the next page. On the other hand, if it is determined that the next page to be recorded is not stored in the print buffer, the process proceeds to step S28, where it is determined whether or not the page has been waited for a predetermined time for the next data until the predetermined time has elapsed. The above steps S27 and S28 are repeated. If the recording data of the next page is not accumulated even after waiting for a predetermined time, the process proceeds to step S29, a wiping operation is performed on the recording head 9, and then a capping operation is performed in step S30.

  In the flowchart shown here, the necessity of the wiping operation is determined at the end of the recording sequence of each page. This is to suppress color unevenness within one page as much as possible in the configuration of the present embodiment in which the wiping operation of a plurality of nozzle rows is performed with one wiper. However, when recording is performed on a plotter having a large recording area or a relatively large recording medium such as A0 size or A1 size, wiping is performed for each recording scan or for each of a plurality of recording scans. Also good.

(5) Features Hereinafter, a control method of the printing apparatus according to the present embodiment when handling a plurality of job data will be described.

  As already described, in the recording apparatus 200 of this embodiment that supplies ink using the supply tube 45 that is a resin having low rigidity and low molecular weight, the gas permeability to the supply tube 45 is also high. Therefore, although there is a concern about the generation of bubbles in every path of the supply tube 45, since air is lighter than ink, all the bubbles tend to gather at the highest point in the path of the supply tube 45 and form a bubble pool. . While the bubble reservoir is small, ink can pass through this side, so the bubble reservoir does not move and there is little concern about ink dropping. However, when the bubble reservoir grows and becomes equal to or larger than the inner diameter of the supply tube 45, the bubble reservoir gradually moves toward the recording head as the ink is consumed. However, since the path from the bubble accumulation position to the inlet 23 of the recording head 9 is filled with ink, if there is a job in which recording is completed with the amount of ink included in this path, the presence of bubbles The recording operation can be completed without any problem. In addition, the size of the bubbles in the bubble reservoir or the timing at which the bubble reservoir moves can be predicted to some extent based on the elapsed time from the time when the suction recovery process for the previous recording head was performed.

  Based on the above situation, the present inventors have reached the following findings. That is, even if bubble accumulation occurs in the supply tube, if it does not reach the recording head, there is no need to perform suction recovery processing. Therefore, if the job can be recorded with an ink amount equal to or less than the ink amount included in the path from the bubble accumulation position to the introduction port 23 of the recording head 9, it is not necessary to perform the suction recovery process before recording the job. . That is, if a job that completes recording with less than the amount of ink included in the path from the bubble accumulation position to the introduction port 23 of the recording head 9 among a plurality of jobs existing in the HDD 1205 is recorded, suction recovery processing is performed. The number of times can be suppressed. For this purpose, the number of dots (ink ejection number) Ud corresponding to the amount of ink contained from the highest point that can become a bubble reservoir to the inlet 23 of the recording head 9 is calculated in advance. In addition, a time Uq from when the previous suction recovery process is performed until the bubble reservoir formed at the highest point starts moving in the recording head direction is also predicted in advance.

  When the recording operation is performed when the elapsed time Tg from the previous suction recovery operation exceeds Uq, the dot count value Dt is selected from the plurality of jobs stored in the HDD 1205 according to the job priority information. Searches for a job whose is smaller than Ud. As a search method, the following two cases are mainly conceivable. In the first case, it is first determined whether or not Dt <Ud for the job with the highest priority. If Dt <Ud, the same determination is performed for the job with the next highest priority. <This method repeats the above determination until a Ud job is found (see FIG. 13 below). The second case is a method of first identifying a job with Dt <Ud from among a plurality of jobs and finding a job having the highest priority among these identified jobs. In any case, a search is performed to identify a job having the highest priority indicated by the priority information among jobs whose Dt is smaller than Ud (that is, jobs that can be recorded without performing suction recovery processing). That's fine. Then, the job specified in this way (the job having the highest priority among the jobs that can be recorded without performing the suction recovery process) is determined as the next job to be recorded. As a result, the job can be recorded without performing the suction recovery process. As a result of the above-described search, it may be determined that there is no job with Dt <Ud. In such a case, the suction recovery process is required for any of the plurality of jobs to be recorded. Therefore, after performing the suction recovery process, the job with the highest priority among the plurality of jobs is selected. A recording operation may be executed.

  FIG. 13 is a flowchart for explaining the steps performed by the controller 102 when executing the recording operation of a plurality of job data in this way. When a plurality of job data are stored in the hard disk (HDD) 1205, the controller 102 first compares the priority information of the plurality of job data in step S600, and selects the job with the highest priority as the job of interest. Set as.

  Next, in step S601, the timer provided in the control block 1308 compares the elapsed time Tq from the timing when the previous suction recovery process was executed to the current time with the time Uq until the bubble pool starts to move. If Tq <Uq, it is determined that the bubble reservoir has not yet started moving, and the process proceeds to step S607. If Tq ≧ Uq, the bubble reservoir has started to move and it is considered that dot count information needs to be considered, and the process proceeds to step S602.

  In step S602, the dot count value Dt of the target job is compared with the threshold value Ud (the number of dots until the bubble reaches the recording head), and it is determined whether or not the suction recovery operation needs to be executed before the target job is recorded. To do. If Dt <Ud, it is determined that the job of interest can execute the recording operation without performing the suction recovery operation. Therefore, the target job is determined as the next recording target job. In step S603, the threshold value Ud is reduced by the number of dots Dt necessary for the job of interest (Ud = Ud−Dt), and the process proceeds to step S607.

  In step S607, the target job data is transferred to the engine controller 1309, and then one job sequence described with reference to FIG. 9 is executed. Thereafter, in step 608, it is determined whether or not the recording of all jobs stored in the HDD 1205 has been completed. If it is determined that the recording has been completed, this processing ends. On the other hand, if it is determined that there are still jobs to be recorded, the process returns to step S600 in order to proceed to the next job of interest.

  If it is determined in step S602 that Dt ≧ Ud, that is, the dot count value of the job of interest is larger than the threshold value, it is determined that the job of interest cannot perform the recording operation without performing the suction recovery operation. In step S604, it is determined whether there is an unprocessed job having a lower priority than the job of interest. If it exists, the process proceeds to step S609, a job having a priority lower than that of the current job of interest is set as a new job of interest, and the process returns to step S602. On the other hand, if it is determined in step S604 that there is no unprocessed job having a lower priority than the job of interest, there is no currently unprocessed job that satisfies Dt <Ud, and the process advances to step S605 to perform suction recovery. Execute the process. Thereafter, Tq and Ud are reset in step S606, and the process returns to step S601.

  As described above, according to S602, S604, and S609, with respect to a job that needs to perform the suction recovery operation before recording (that is, a job having a dot count value larger than the threshold value), the recording is postponed to perform the suction recovery operation. It is possible to search for a recordable job without performing the process.

  In the processing described above, when recording data to which priority information is not given is handled, priorities may be grouped according to the recording mode or the like. For example, in the high-speed mode, since the recording speed is generally more important than the image quality, it is preferable to set the priority higher. On the other hand, in the high image quality mode, the image quality is often more important than the recording speed. Therefore, the priority is low, and it is desirable to perform recording reliably after performing the suction recovery operation.

  As described above, according to the present embodiment, even if a bubble is generated in the supply tube, a printable job is preferentially recorded with the amount of ink until the bubble reaches the recording head. As a result, the number of suction recovery operations can be reduced. As a result, it is possible to reduce the time and ink consumption associated with the suction recovery operation and improve the running cost and time cost.

(Second Embodiment)
The second embodiment of the present invention will be described below. In the present embodiment as well, similarly to the first embodiment, control is performed based on the recording apparatus, the recording head, and various sequences shown in FIGS.

  In general, the serial type ink jet recording apparatus as described above employs a multi-pass recording method in which recording data in a unit area that can be recorded by one recording scan by the recording head is divided into a plurality of recording scans. There are many cases. In the multi-pass printing method, by performing a transport operation smaller than the printing width of the printing head during each printing scan, the recording characteristics of individual nozzles are prevented from being concentrated on one line and excellent in uniformity. An image can be output. As the number of printing scans per unit area, that is, the number of multi-passes is increased, the effect of improving the uniformity is increased. However, as the number of multi-passes increases, the time required to complete the image also increases, so even when recording on the same recording medium, multiple recording modes with different multi-pass numbers such as the high-speed mode and the high-quality mode are used. In general, the user selects a recording mode according to the application.

  By the way, the size of the number of multi-passes affects the number of dots to be recorded in one recording scan and thus the flow speed of ink flowing in the supply tube. This is because in the printing mode with a large number of multi-passes, the number of ejections of one printing scan is small and the flow velocity in the tube is kept small, but the number of ejections of one printing scan increases as the number of multi-passes decreases. This is because the flow velocity in the tube also increases. In such a situation, even when the same image is recorded, the multipass recording with a large flow velocity has a higher flow pressure to the bubble reservoir than the multipass recording with a low flow velocity, and the bubbles are generated. It can be said that it is easy to move.

  In view of such a situation, in the situation where a plurality of job data is stored in the HDD 1205, the inventors execute the suction recovery operation before recording based on not only the dot count number Dt but also the multi-pass number. Make a decision of no.

  FIG. 14 is a flowchart for explaining the steps performed by the controller 102 when the recording apparatus of the present embodiment executes a recording operation for a plurality of job data. The flowchart in this embodiment is basically the same as the flowchart shown in FIG. 13 in the first embodiment. However, since the subsequent processes differ when it is determined NO in step S601, only the subsequent processes will be described here.

  Even if it is determined NO in step S601, that is, when it is determined that Tq <Uq and the bubble reservoir has not yet started to move, there is a concern that bubbles move if the number of multipaths is small. Therefore, in this embodiment, the process proceeds to step S704, and the average recording duty Dd of the recording scan for the job of interest is calculated. Here, the average recording duty Dd can be regarded as a value obtained by dividing the dot count value Dt by the number of recording scans required to record one page image, that is, an average value of the number of ejections of individual recording scans. This is a value that correlates with the flow velocity. In step S705, the recording duty Ud2 that generates a flow velocity that can move even if the bubble does not reach the inner diameter of the tube is compared with Dd calculated in step S704. If Dd <Ud2 in step S705, it is determined that there is no concern that bubbles move, and the process proceeds to step S607 to transfer the job data of interest to the engine controller 1309, and then execute one job sequence described in FIG. To do.

  On the other hand, if Dd ≧ Ud2 in step S705, it is determined that there is a concern that bubbles may move in the job of interest, and before executing suction recovery, it is determined whether there is a job with a lower flow velocity. The process proceeds to step S706. In step S706, it is determined whether a job having a lower priority than the job of interest still remains. If the job still remains, the job of interest is transferred to a job having a lower priority, and the process returns to step S704. On the other hand, if it is determined that there is no job having a lower priority than the job of interest, the process proceeds to step S708, the suction recovery process is executed, Tq and Ud2 are reset in step S709, and the process returns to step S600.

  As described above, according to the present embodiment, even if bubbles are generated in the tube, a job that can be recorded with the ink amount until the bubbles reach the recording head, or the bubbles do not move. Priority is given to jobs that can be recorded at a flow velocity of. As a result, the number of suction recovery operations can be reduced, and time and ink consumption associated with the suction recovery operation can be suppressed, and running costs and time costs can be improved.

2 Carriage unit 9 Recording head 27 Cap 29 Suction pump 39 Ink tank 45 Supply tube 102 Controller

Claims (3)

In an inkjet recording apparatus that records an image on a recording medium while moving the recording head in a state where the ink tank and the recording head are connected via a supply tube,
A suction recovery means for performing a suction recovery process capable of sucking air bubbles in the supply tube together with ink through the recording head;
Storing a plurality of job data including image data, information relating to the number of ejections of the recording head required to record the image data, and priority information serving as a priority index for recording the image data. Storage means capable of
Selection means for selecting one job data from the plurality of job data based on the priority information;
Determination means for determining whether or not the suction recovery process needs to be executed before recording the job data selected by the selection means, based on the information regarding the number of ejections;
An inkjet recording apparatus comprising: a determination unit that determines job data selected by the selection unit as job data to be recorded next when it is determined that the suction recovery process is not necessary.   The inkjet recording apparatus according to claim 1, wherein the selection unit selects job data having the highest priority of the priority information among job data that has not been determined by the determination unit. In an inkjet recording method for recording an image on a recording medium while moving the recording head in a state where the ink tank and the recording head are connected via a supply tube,
Executing a suction recovery process for sucking air bubbles in the supply tube together with ink through the recording head;
A storage for storing a plurality of job data including image data, information relating to the number of ejections of the recording head required to record the image data, and priority information serving as a priority index for recording the image data Process,
A selection step of selecting one job data from the plurality of job data based on the priority information;
A determination step of determining whether or not it is necessary to execute the suction recovery process before recording the job data selected in the selection step according to the information regarding the number of ejections;
A determination step of determining the job data selected in the selection step as job data to be recorded next when it is determined that the suction recovery process need not be executed;
And a step of recording an image on the recording medium using the recording head in accordance with the job data determined in the determining step.

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