JP2011161762A - Inkjet recorder and reserve discharging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder which executes a reserve discharging at a proper frequency while suppressing deterioration in throughput, when recording in a dye ink and pigment ink, and to provide a reserve discharging method. <P>SOLUTION: In the inkjet recorder, when executing a reserve discharging with a dye ink, a recording head scans the outside of a recording medium for each predetermined amount of scanning of the recording head, and discharges a dye ink not involved in recording, from a dye ink discharging outlet of the recording head outside the recording medium. The inkjet recorder also has a cap to collect a pigment ink discharged for reserve discharged from a pigment ink discharging outlet and not involved in recording. Then, after recording on a sheet of a recording medium is finished, in conjunction with discharging of the recording medium by a sheet discharging means, the recording head discharges a pigment ink not involved in recording from the pigment ink discharging outlet of the recording head, in the position where a pigment ink is collected by a pigment ink collecting means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus and a preliminary ejection method for performing preliminary ejection to recover ejection of a recording head in the inkjet recording apparatus.

  Conventionally, in an ink jet recording system, it is known that a discharge recovery process is performed in order to solve problems such as a decrease in recording quality caused by a discharge failure such as nozzle clogging in a recording head. As one of the ejection recovery processes, ink that does not participate in recording is ejected from the recording head to a predetermined position other than the recording area immediately before recording, thereby discharging ink with increased viscosity in the nozzles. In other words, so-called preliminary discharge is performed.

  In general, the preliminary ejection includes a system in which the recording head is temporarily stopped at a predetermined position to eject a predetermined amount of ink, and a system in which the recording head is ejected without being stopped (hereinafter, this system is referred to as “flowing”). It is called “preliminary discharge”. The preliminary flow discharge is a preliminary discharge to a predetermined portion outside the recording medium while moving the recording head. In particular, in order to improve the recording throughput in the ink jet recording apparatus, the preliminary flow discharge is often employed.

  An ink jet recording apparatus that performs such preliminary flow discharge is disclosed in Patent Document 1. Patent Document 1 discloses an ink jet recording apparatus that can change the frequency of flow preliminary discharge depending on recording conditions.

JP-A-11-334096

  However, since the preliminary discharge is performed on the platen, the discharge is generally performed with a dye ink that is difficult to deposit on the platen. However, preliminary ejection may also be performed in an ink jet recording apparatus in which recording is performed using both pigment ink and dye ink. In this case, if the preliminary discharge is performed for the dye ink and the preliminary discharge is also performed for the pigment ink, the pigment ink accumulates on the platen, and the recording medium on which recording is performed next is soiled. There is a possibility. In addition, if preliminary ejection is performed with both the dye ink and pigment ink capped with the ejection port capped, the recording head moves to the cap and the recording head is temporarily stopped to eject the pigment ink. As a result, the throughput decreases.

  Accordingly, the present invention has been made in view of the above circumstances, and in the case where recording is performed using a dye ink and a pigment ink, an ink jet capable of performing preliminary ejection at an appropriate frequency while suppressing a decrease in throughput. It is an object to provide a recording apparatus and a preliminary discharge method.

  An inkjet recording apparatus of the present invention includes a recording head having a dye ink discharge port for discharging dye ink, a pigment ink discharge port for discharging pigment ink, and a transport unit for transporting a recording medium. Scanning means for reciprocally moving the recording head in the main scanning direction intersecting with the conveying direction in which the recording medium is conveyed, recording medium supplying means for supplying the recording medium, and recording medium for discharging the recording medium Discharging means, discharging the dye ink and the pigment ink from the recording head to perform recording on a recording medium, and the recording head from the discharge port for dye ink and the discharge port for pigment ink other than the recording medium In an inkjet recording apparatus that performs preliminary ejection by ejecting dye ink and pigment ink that are not involved in recording to a place, for each predetermined amount of scanning of the recording head A dye that controls the preliminary ejection by the dye ink so that the recording head is scanned to the outside of the recording medium, and the dye ink that does not participate in recording is ejected from the ejection port for the dye ink of the recording head outside the recording medium Ink pre-ejection control means, pigment ink collecting means for collecting pigment ink not involved in recording ejected for pre-ejection from the pigment ink ejection port, and after recording on one recording medium is completed In parallel with the discharge of the recording medium by the recording medium discharge means, the pigment ink that does not participate in the recording is discharged from the discharge port for the pigment ink of the recording head at a position where the pigment ink is recovered by the pigment ink recovery means. And a pigment ink preliminary ejection control means for controlling preliminary ejection by the pigment ink.

  Further, the preliminary ejection method of the present invention includes a recording head having a dye ink ejection port for ejecting a dye ink, a pigment ink ejection port for ejecting a pigment ink, and a conveying means for conveying a recording medium. Scanning means for reciprocating the recording head in the main scanning direction intersecting with the conveyance direction in which the recording medium is conveyed, scanning recording medium supply means for supplying the recording medium, and discharging the recording medium And a recording medium discharge means, wherein the recording head discharges the dye ink and the pigment ink from the recording head and performs recording on the recording medium. In a preliminary ejection method for performing preliminary ejection by ejecting dye ink and pigment ink not involved in recording from an outlet to a place other than a recording medium, the recording head includes: Each time a fixed amount of scanning is performed, the recording head is scanned to the outside of the recording medium, and the dye ink that is not involved in recording is discharged from the dye ink discharge port of the recording head outside the recording medium. In order to perform preliminary ejection from the pigment ink ejection port in parallel with the dye ink preliminary ejection control step for controlling ejection and the ejection of the recording medium by the recording medium ejection means after the recording on one recording medium is completed. The pigment is ejected from the pigment ink ejection port of the recording head at a position where the pigment ink is collected by the pigment ink collecting means for collecting the pigment ink that is not involved in the recording. And a pigment ink preliminary ejection control step for controlling preliminary ejection by ink.

  According to the present invention, even when recording is performed using dye ink and pigment ink, it is possible to maintain a high throughput in recording while performing preliminary discharge at an appropriate frequency.

1 is a perspective view showing an appearance of a main part of an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view showing an overall appearance when a main part of the ink jet recording apparatus of FIG. 1 is housed in a housing. FIG. 2 is a block diagram of a control system of the ink jet recording apparatus of FIG. 1. 2 is a flowchart illustrating a control flow when preliminary ejection is performed by the ink jet recording apparatus of FIG. 1. FIG. 2 is an explanatory diagram for explaining timings of preliminary ejection with dye ink and preliminary ejection with pigment ink by the ink jet recording apparatus of FIG. 1. 10 is a flowchart showing a control flow when preliminary ejection is performed by the ink jet recording apparatus according to the second embodiment of the present invention. When the preliminary ejection is performed according to the flow of FIG. 6, the recording time for recording on one recording medium, the number of preliminary ejections with dye ink and the number of preliminary ejections with pigment ink that change in accordance with the recording time. It is a table which shows the relationship between. It is explanatory drawing for demonstrating the timing at which the preliminary discharge by dye ink and the preliminary discharge by pigment ink are performed when the preliminary discharge in other embodiment is performed.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
In the embodiments described below, an embodiment in which the present invention is applied to an ink jet recording apparatus using a recording head to which an ink jet method is applied that performs recording by discharging ink onto a recording medium will be described.

(Configuration of inkjet recording apparatus)
FIG. 1 is a perspective view showing an outline of a configuration of main parts of an ink jet recording apparatus 1 which is a typical embodiment of the present invention.

  As shown in FIG. 1, an ink jet recording apparatus (hereinafter referred to as a recording apparatus) performs recording by discharging ink from a recording head 3 to a recording medium according to an ink jet system. The recording head 3 has a dye ink discharge port for discharging dye ink and a pigment ink discharge port for discharging pigment ink. The driving force generated by the carriage motor M1 is transmitted from the transmission mechanism to the carriage 2 on which the recording head 3 is mounted, and the carriage 2 is reciprocated. FIG. 2 is a perspective view showing an appearance of an ink jet recording apparatus having the main part of FIG. 1 inside. As shown in FIG. 2, the ink jet recording apparatus 1 includes a paper supply unit 10 as a recording medium supply unit for supplying a recording medium P such as recording paper, and the paper supply unit 10 records the recording medium. Transport to position. Then, recording is performed by discharging dye ink and pigment ink from the recording head 3 to the recording medium P at the recording position. In addition, a discharge unit 11 is provided as a recording medium discharge unit for discharging the recording medium P on which an image is formed by the recording head 3 to the outside of the ink jet recording apparatus. The paper discharge means 11 has a discharge roller (not shown), and the discharge roller is driven by the rotation of the transport motor. The discharge roller is brought into contact with a spur roller (not shown) that presses the recording medium P with a spring (not shown), and the recording medium P is sandwiched and driven between the discharge roller and the spur roller, thereby recording the recording medium. P is discharged from the inkjet recording apparatus 1.

  In addition to mounting the recording head 3 on the carriage 2 of the recording apparatus 1, an ink cartridge 6 for storing ink to be supplied to the recording head 3 is mounted. The ink cartridge 6 is detachable from the carriage 2. Note that the recording head 3 and the ink cartridge 6 may be integrally formed.

  The recording apparatus 1 shown in FIG. 1 is capable of color recording. For this purpose, the carriage 2 contains four inks respectively containing magenta (M), cyan (C), yellow (Y), and black (K) inks. A cartridge is installed. These four ink cartridges can be attached and detached independently.

  The carriage 2 and the recording head 3 can achieve and maintain a required electrical connection by properly contacting the joint surfaces of both members. The recording head 3 applies energy according to a recording signal to selectively eject ink from a plurality of ejection ports for recording. In particular, the recording head 3 of this embodiment employs an ink jet system that ejects ink using thermal energy. The recording head 3 includes an electrothermal converter for generating thermal energy, and converts the electric energy applied to the electrothermal converter into thermal energy. Then, the thermal energy is applied to the ink to cause film boiling in the ink, and the ink is ejected from the ejection port by utilizing the pressure change caused by the growth and contraction of the bubbles generated thereby. The electrothermal transducer is provided corresponding to each of the ejection ports, and ink is ejected from the corresponding ejection port by applying a pulse voltage to the corresponding electrothermal transducer in accordance with the recording signal.

  As shown in FIG. 1, the carriage 2 is connected to a part of a driving belt 7 of a transmission mechanism that transmits the driving force of the carriage motor M1. Accordingly, the carriage 2 is guided and supported so as to be slidable in the direction of arrow A along the guide shaft 13. The carriage 2 on which the recording head 3 is mounted is reciprocated by the driving force of the carriage motor M1. At the same time, a recording signal is given to the recording head 3 and ink is ejected onto the recording medium. Accordingly, the carriage 2 reciprocates in the main scanning direction intersecting the conveyance direction in which the recording medium is conveyed along the guide shaft 13 by the forward rotation and the reverse rotation of the carriage motor M1. Further, a scale (not shown) is provided for indicating the position of the carriage 2 along the moving direction of the carriage 2 (arrow A direction). As described above, it has scanning means for scanning the carriage 2 on which the recording head 3 is mounted by reciprocating in the main scanning direction. Recording is performed over the entire width of the recording medium P by performing recording while the recording head scans by the scanning unit. Further, the recording apparatus 1 is provided with a platen so as to face the discharge port surface where the discharge port of the recording head 3 is formed.

  Further, the ink jet recording apparatus 1 includes a transport roller 14 that is driven by a transport motor M2 to transport the recording medium P. The inkjet recording apparatus 1 is connected to a pinch roller 15 that contacts the recording medium P with the conveyance roller 14 by a spring (not illustrated), a pinch roller holder (not illustrated) that rotatably supports the pinch roller 15, and the conveyance roller 14. In addition, a conveyance roller gear (not shown) is included. Then, the transport roller 14 is driven by the rotation of the transport motor M2 transmitted to the transport roller gear via the intermediate gear. As described above, the ink jet recording apparatus 1 includes a transport unit that transports the recording medium.

  Further, the ink jet recording apparatus 1 is provided with a cap 226 that caps the ejection port of the recording head 3 and can receive the ink ejected from the recording head 3. Preliminary ejection with pigment ink is performed with the cap 226 capping the ejection port of the recording head 3, and the ink ejected by the preliminary ejection with the pigment ink can be collected by sucking the ink in the cap. Is possible. Further, a platen preliminary discharge position home 224 and a platen preliminary discharge position away 225 that can receive ink discharged when preliminary discharge is performed on the platen are arranged outside the recording medium P in FIG.

(Control configuration of inkjet recording apparatus)
FIG. 3 is a block diagram showing a control configuration of the recording apparatus shown in FIG. As shown in FIG. 3, the controller 600 includes an MPU 601, a ROM 602, a special purpose integrated circuit (ASIC) 603, a RAM 604, a system bus 605, an A / D converter 606, and the like. The ROM 602 stores a program corresponding to the control sequence, a required table, and other fixed data. The ASIC 603 generates control signals for controlling the carriage motor M1, the transport motor M2, and the recording head 3. The RAM 604 is configured as a development area for image data and a work area for program execution. A system bus 605 connects the MPU 601, the ASIC 603, and the RAM 604 to each other to exchange data. The A / D converter 606 receives an analog signal from the sensor, performs A / D conversion, and supplies a digital signal to the MPU 601.

  In FIG. 3, reference numeral 610 denotes a computer (or an image reading reader, digital camera, or the like) serving as an image data supply source, and is collectively referred to as a host device. Image data, commands, status signals, and the like are transmitted and received between the host apparatus 610 and the recording apparatus 1 via an interface (I / F) 611.

  Reference numeral 620 denotes a switch group, which includes switches for receiving command inputs from the operator, such as a power switch 621, a print switch 622, and a recovery switch 623. The print switch 622 is a switch for instructing the start of printing. The recovery switch 623 is a switch for instructing the start of processing (recovery processing) such as preliminary ejection for maintaining the ink ejection performance of the recording head 3 in a good state. Reference numeral 630 denotes a position sensor 631 such as a photocoupler for detecting the home position h, a temperature sensor 632 provided at an appropriate location of the recording apparatus for detecting the environmental temperature, and the like. It is a sensor group. Further, the sensor group includes a recording time detection unit 633 for detecting a recording time required to record one recording medium described later.

  Further, 640 is a carriage motor driver that drives a carriage motor M1 for reciprocating scanning of the carriage 2 in the direction of arrow A, and 642 is a conveyance motor driver that drives a conveyance motor M2 for conveying the recording medium P.

  With the configuration as described above, the recording apparatus main body analyzes the command of the recording data transferred via the interface 611 and develops image data used for recording in the RAM 602. The image data development area (development buffer) is a two-dimensional rectangular area, and its horizontal size corresponds to the number of pixels Hp corresponding to the recordable area in the carriage movement direction (main scanning direction). Further, the vertical size of the development area of the image data is set to 4 of cells corresponding to 16 × 16 pixels, which is the number of pixels in the conveyance direction (sub-scanning direction) of the recording medium recorded by one recording scan of the recording head. It is configured so as to correspond to the number of parts (that is, cells corresponding to 64 pixels). This is secured in the RAM 602.

  A storage area (print buffer) on the RAM 602 that is referred to for transferring print data to the print head 3 in print scanning is also a two-dimensional rectangular area. The horizontal size of the image data corresponds to the number of pixels Vp corresponding to the recordable area in the main scanning direction, and the vertical size of the image data is the number of pixels in the sub-scanning direction recorded by one recording scan of the recording head. It is configured to correspond to a cell corresponding to × 16 pixels. Then, this is secured on the storage area of the RAM 602.

  The ASIC 603 transfers drive data (DATA) of the printing element (ejection heater) to the printing head while directly accessing the storage area of the RAM 602 during printing scanning by the printing head 3.

(Discharge recovery method of recording head of this embodiment)
Next, an outline of an ejection recovery method by preliminary ejection of the recording head in the inkjet recording apparatus of the present embodiment will be described. The ink jet recording apparatus 1 of the present embodiment intermittently performs the ejection recovery process of the recording head 3 in order to maintain the state of the recording head 3 satisfactorily. At this time, the recording head 3 discharges the dye ink and the pigment ink not involved in recording from the discharge port for the dye ink and the discharge port for the pigment ink to a place other than the recording medium, and performs preliminary discharge as a discharge recovery process. . The ink jet recording apparatus of the present embodiment is characterized by a recording head ejection recovery method, and FIG. 4 is a flowchart showing an outline of the recording head ejection recovery method. First, in S11, in response to a recording command from the user, the recording medium P is fed to the recording apparatus 1 to prepare for recording. Next, in S12, recording is started by the ink jet recording apparatus. At this time, the recording head 3 reciprocates and scans the recording medium P while ejecting ink droplets to form an image. In S13, in order to recover the ejection of the recording head 3, when the recording head 3 is positioned outside the recording medium P by scanning, the recording head 3 performs preliminary ejection on the platen while performing scanning.

  FIG. 5 is an explanatory diagram for explaining the timing at which the preliminary ejection is performed when the recording operation is performed on one recording medium. Reference numerals 61 and 62 shown in FIG. 5 indicate timings at which preliminary ejection with dye ink and preliminary ejection with pigment ink are performed in the process of recording on one recording medium. In the present embodiment, the preliminary ejection 61 for the dye ink is performed every time one reciprocal scan (a predetermined amount of scan) is performed once. Here, when the recording head 3 reaches the right end of the recording medium P by the scanning of the recording head 3, the recording head 3 continues to scan further, passes through the recording medium P, and further to the right side of the recording medium P. Located in. When the recording head 3 passes through the recording medium P and reaches the platen, the recording head 3 performs preliminary ejection of the dye ink toward the platen.

  Then, during the paper discharge operation after the recording on the recording medium P is completed, the preliminary discharge 62 for the pigment ink is performed. By controlling the ejection recovery method by preliminary ejection of the recording head 3 in this way, the step of moving the recording head 3 over the cap 226 every predetermined scanning amount in order to perform preliminary ejection with dye ink can be omitted. it can. Accordingly, it is possible to shorten the time required for the recording head 3 to move over the cap in order to perform preliminary ejection, and it is possible to suppress a decrease in throughput while maintaining the ejection performance of the recording head.

  In the present embodiment, preliminary ejection with dye ink is performed when the recording head is positioned outside on one side of the recording medium. As shown in FIG. 5, in the present embodiment, preliminary ejection is performed when the recording head is positioned outside the right side of the recording medium. The preliminary discharge performed at this time is a flow preliminary discharge in which ink is discharged toward the platen outside the recording medium while the recording head is moving as described above.

  Note that the preliminary ejection with the dye ink performed at this time is not limited to an external position on the right side of the recording medium. The position on the platen where the preliminary discharge is performed may be either left or right as long as the position is outside the recording medium such as the platen preliminary discharge position home 224 and the platen preliminary discharge position away 225 shown in FIG. However, in order to prevent the throughput in recording from being reduced as much as possible, it is desirable that the preliminary ejection position is performed as close to the recording medium as possible.

  At this stage, preliminary discharge with pigment ink is not performed. If preliminary ejection with pigment ink is performed at this stage, pigment ink may be deposited on the platen. If the pigment ink is deposited on the platen, there is a possibility that the next recording medium will be contaminated when passing the recording position corresponding to the recording head. Accordingly, here, only preliminary ejection with dye ink is performed. In this way, the recording head 3 is scanned to the outside of the recording medium for every predetermined amount of scanning of the recording head 3. Then, the dye ink that does not participate in the recording is ejected from the dye ink ejection port of the recording head 3 outside the recording medium (dye ink preliminary ejection control step). In this way, preliminary ejection with dye ink is controlled. At this time, in the inkjet recording apparatus 1, the controller 600 including the MPU 601, the ROM 602, the ASIC 603, the RAM 604, and the like functions as a dye ink preliminary ejection control unit that controls preliminary ejection with the dye ink.

  When the formation of the image on the recording medium by the recording head is completed in S14, the recording head moves over the cap 226 shown in FIG. Waits on the cap 226. Here, the cap 226 is configured to be able to collect the pigment ink that is not involved in the recording ejected for the preliminary ejection from the pigment ink ejection port. As described above, in this embodiment, the cap 226 functions as a pigment ink collecting unit that collects the pigment ink that is not involved in the recording ejected from the pigment ink ejection port in the preliminary ejection with the pigment ink. When the recording head reaches the cap 226, the recording medium is discharged in S15. In parallel with this, preliminary ejection with pigment ink, which has not been performed during recording, is performed on the cap 226. The If the preliminary ejection with the pigment ink is performed into the cap 226, the waste ink discharged to the cap 226 can be collected. Therefore, since the ink ejected by the preliminary ejection does not remain on the platen, there is no need to worry about subsequent staining of the recording medium due to the accumulation of the pigment ink. In addition, it is also possible to perform preliminary discharge of dye ink in accordance with this time. As described above, since the preliminary ejection with the pigment ink is performed during the ejection of the recording medium, the ejection process of the recording medium and the preliminary ejection process with the pigment ink can be performed at the same time, compared with the case where these are performed separately. Throughput can be improved.

  As described above, after the recording on one recording medium is completed, the pigment ink not involved in the recording is ejected from the pigment ink ejection port of the recording head 3 in parallel with the ejection of the recording medium by the ejection unit. Thus, preliminary ejection with pigment ink is performed (pigment ink preliminary ejection control step). Here, the preliminary ejection with the pigment ink is performed at a position where the pigment ink is collected by a cap 226 as a pigment ink collecting means.

  Here, the controller 600 having the MPU 601, the ROM 602, the ASIC 603, the RAM 604, and the like functions as a pigment ink preliminary ejection control unit that controls preliminary ejection with pigment ink. In the present embodiment, in the preliminary ejection with the dye ink, the number of ejections of the pigment ink for ejecting the dye ink that is not involved in the recording from the dye ink ejection port of the recording head is controlled to be constant. In the preliminary ejection with pigment ink, the number of ejections of pigment ink for ejecting pigment ink that is not involved in recording from the pigment ink ejection port of the recording head is controlled to be constant.

  When the recording medium discharge operation is finished in S16, the recording on one recording medium is finished. Here, the preliminary discharge of the pigment ink has been described as being discharged. However, if it is difficult to complete the preliminary discharge of the pigment ink during the paper discharge operation, the preliminary discharge ends after the paper discharge operation ends. Also good. Further, if it is known in advance that it is difficult to complete the preliminary discharge of the pigment ink during the paper discharge operation, the preliminary discharge with the pigment ink may be performed before the paper discharge operation. As long as the recording medium discharge process and the preliminary ejection process using pigment ink at least partially overlap, it is not necessary to fit within the recording medium discharge process.

(Second embodiment)
Next, a second embodiment for carrying out the present invention will be described. The description of the same configuration as in the first embodiment will be omitted, and only different parts will be described. Hereinafter, a method for recovering the ejection of the recording head in the ink jet recording apparatus according to the second embodiment will be described.

  In the first embodiment, the number of ejections in the preliminary ejection for the dye ink and the pigment ink is performed by ejecting a certain number of ejections. In contrast, the preliminary ejection in the second embodiment is different from the first embodiment in that the number of ejections in the preliminary ejection of the dye ink and the pigment ink is controlled according to the recording time on the recording medium. Different. By performing the preliminary ejection operation in this way, preliminary ejection with the dye ink and the pigment ink can be performed as much as necessary, and the amount of ink consumed by the preliminary ejection can be kept small.

  An outline of a recording head ejection recovery method in the ink jet recording apparatus of the present embodiment will be described. FIG. 6 is a flowchart showing an outline of the preliminary ejection process of the recording head in the second embodiment. First, in S21, in response to a recording command from the user, the recording medium is fed to prepare for recording. Next, in S22, recording is started by the ink jet recording apparatus, and an image is formed by ejecting ink droplets while the recording head reciprocates on the recording medium. When image recording is started in S23, the time required for recording on the single recording medium is measured. As described above, the ink jet recording apparatus according to the present embodiment includes the recording time detecting unit 633 that detects the time required for recording on one recording medium. Here, as the recording time detection means 633, the size of the recording medium may be detected by a sensor, and the recording time required for recording one recording medium may be detected from the detected size of the recording medium. . Alternatively, recording may be performed on a single recording medium in advance, and the recording time may be actually measured by a timer. Further, the recording time detecting means of other means may be used. In step S24, in order to recover the ejection of the recording head 3, preliminary ejection of dye ink is performed on the platen for each predetermined scanning amount.

  In this preliminary ejection with dye ink, the dye ink is ejected by the number of preliminary ejections shown in the table of FIG. 7 according to the detected recording time. In this way, the preliminary ejection with the dye ink is controlled so that the number of ejections of the dye ink not involved in the recording from the ejection port for the dye ink of the recording head 3 changes according to the recording conditions. In this case, the number of ejections of the dye ink that is not involved in the recording ejected from the ejection port for the dye ink of the recording head is changed so as to change according to the time required for recording on one detected recording medium. The preliminary discharge by is controlled. Specifically, when the time required for recording on one recording medium is long, the number of ejection times of dye ink not involved in recording is set higher than when the time required for recording on one recording medium is short.

  When the formation of an image on the recording medium by the recording head 3 is completed in S25, the recording head 3 moves onto the cap 226 in FIG. stand by. When the recording head 3 reaches the cap 226 and the recording medium is discharged in S26, the preliminary ejection of the pigment ink that has not been previously performed during the recording is performed on the cap 226 accordingly. carry out. The preliminary ejection at this time is defined by the time measured in S23, and is performed by the number of preliminary ejections shown in the table of FIG.

  As described above, the preliminary ejection with the pigment ink is controlled so that the number of ejections of the pigment ink that is not involved in the recording from the pigment ink ejection port of the recording head 3 changes according to the recording conditions. In this case, the number of ejections of the pigment ink that is not involved in the recording ejected from the pigment ink ejection port of the recording head 3 is changed so as to change according to the time required for recording on one detected recording medium. Preliminary ejection with ink is controlled. Specifically, when the time required for recording on a single recording medium is long, the number of ejections of pigment ink not involved in recording is set higher than when the time required for recording on a single recording medium is short.

  Since the preliminary ejection is controlled in this way, when the recording time is short, only the preliminary ejection of the recording head 3 by the small number of preliminary ejections is performed. When the recording time is short, the degree of thickening due to the ink in the discharge port is small, and therefore, a small number of preliminary discharges is sufficient for the recovery process of the recording head 3. As described above, according to the present embodiment, since the number of preliminary ejections can be reduced, the time for preliminary ejection can be shortened, and the printing throughput can be further improved. In addition, according to the present embodiment, it is possible to avoid wasteful discharge of waste ink by performing preliminary ejection for a necessary amount. As a result, the amount of ink consumed can be kept low, and the maintenance cost of the ink jet recording apparatus can be kept low. In addition, since waste ink can be reduced, an environment-friendly inkjet recording apparatus can be provided.

(Other embodiments)
In the above-described embodiment, the preliminary ejection for the dye ink is performed at a position outside the recording medium on one side of the recording medium, but the present invention is not limited to this. The preliminary ejection for the dye ink may be performed on both the left and right sides of the recording medium. In other words, in an ink jet recording apparatus that performs bidirectional recording in which the recording head performs recording in both the forward and backward scans of the reciprocating scan, preliminary ejection of the dye ink is performed each time recording by one-way scanning is performed. It is good to be. At this time, the recording head scans on both outer platens of the recording medium, and ink is ejected by dye ink not involved in recording onto both outer platens of the recording medium.

  Further, when preliminary ejection with dye ink is performed outside both sides of the recording medium and the recording area on the recording medium is relatively small, the recording head does not have to scan to the outside of the recording medium. good. In such a case, as shown in FIG. 8, the scanning in the forward direction by the recording head is terminated halfway, and the scanning in the backward direction is started from there. In the recording medium P shown in FIG. 8, a recording image I1 having a relatively small length in the main scanning direction and a recording image I2 having a relatively large length in the main scanning direction are recorded. At this time, when recording the recorded image I1 having a relatively small length in the main scanning direction, the recording head stops scanning halfway. At this time, since the recording head does not move to the outside of the recording medium, the preliminary ejection with the dye ink is not performed here. Then, when the recording head finishes scanning in the backward direction and is positioned outside the recording medium, preliminary ejection with the dye ink may be performed. At this time, it is determined that recording for one scanning in the forward direction in the recording area is completed based on the recording data, and recording is performed when it is determined that recording for one scanning in the forward direction in the recording area is completed. The head returns and scanning in the backward direction is started. In this way, unnecessary scanning by the recording head can be omitted, and the throughput of the recording apparatus can be further improved. Further, when recording a recording image I2 having a relatively large length in the main scanning direction, the preliminary ejection of the dye ink may be performed each time recording is performed by scanning in one direction.

  Further, in the second embodiment described above, the time required for recording on one recording medium is detected, and the number of ink ejections in preliminary ejection with dye ink and pigment ink changes according to the detected recording time. It is supposed to be. At this time, as a recording condition for determining the number of ejections of the dye ink and the pigment ink in the preliminary ejection, the time required for recording on one recording medium is used, but the present invention is not limited to this. The temperature around the recording head at the time of recording may be detected, and the number of ink ejections during preliminary ejection with dye ink and pigment ink may be changed according to the detected temperature around the recording head. Further, the number of ejections of the dye ink and the pigment ink in the preliminary ejection may be determined according to other conditions such as the humidity around the recording head. In this way, the preliminary ejection with the dye ink and the pigment ink may be controlled so that the number of ink ejections in the preliminary ejection with the dye ink and the pigment ink changes according to other recording conditions.

  In the first embodiment, the number of ejections is constant in both the preliminary ejection with the dye ink and the preliminary ejection with the pigment ink. In the second embodiment, the number of times of ejection changes according to the recording conditions in both preliminary ejection with dye ink and preliminary ejection with pigment ink. However, the present invention is not limited to these embodiments. Only one of the preliminary ejection with the dye ink and the preliminary ejection with the pigment ink may be changed according to the recording conditions. At this time, only the number of preliminary ejections with dye ink may be changed according to the recording conditions, or only the number of preliminary ejections with pigment ink may be changed according to the recording conditions.

  In this specification, “recording” (sometimes referred to as “printing”) is used not only for forming significant information such as characters and graphics but also regardless of significance. It also represents a case where an image, a pattern, a pattern, etc. are widely formed on a recording medium, or a medium is processed, regardless of whether it is manifested so that humans can perceive it visually. To do.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  Further, “ink” (sometimes referred to as “liquid”) should be interpreted widely as in the definition of “recording (printing)”. By being applied on the recording medium, it can be used for formation of images, patterns, patterns, etc., processing of the recording medium, or ink processing (for example, solidification or insolubilization of the colorant in the ink applied to the recording medium). It shall represent a liquid.

  Furthermore, unless otherwise specified, the “nozzle” collectively refers to an ejection port or a liquid channel communicating with the ejection port and an element that generates energy used for ink ejection.

3 Recording Head 10 Paper Feed Unit 11 Paper Discharge Unit 224 Platen Preliminary Discharge Position Home 225 Platen Preliminary Discharge Position Away 226 Cap

Claims (8)

A recording head having a discharge port for dye ink for discharging dye ink, a discharge port for pigment ink for discharging pigment ink, a transport unit for transporting the recording medium, and transport for transporting the recording medium Scanning means for reciprocating and scanning the recording head in the main scanning direction intersecting the direction, recording medium supplying means for supplying the recording medium, and recording medium discharging means for discharging the recording medium,
Recording the recording medium by discharging the dye ink and the pigment ink from the recording head;
In the inkjet recording apparatus in which the recording head performs preliminary discharge by discharging dye ink and pigment ink not involved in recording from the discharge port for dye ink and the discharge port for pigment ink to a place other than the recording medium,
Each time the recording head scans a predetermined amount, the recording head is scanned to the outside of the recording medium, and the dye ink not involved in recording is ejected from the recording ink ejection port of the recording head outside the recording medium. Dye ink preliminary discharge control means for controlling preliminary discharge with dye ink,
Pigment ink collection means for collecting pigment ink that does not participate in recording discharged for preliminary discharge from the pigment ink discharge port;
At the position where the pigment ink is recovered by the pigment ink recovery means in parallel with the discharge of the recording medium by the recording medium discharge means after the recording on one recording medium is completed, An ink jet recording apparatus comprising: a pigment ink preliminary discharge control unit that controls preliminary discharge by pigment ink so as to discharge pigment ink not involved in recording from an ejection port.   2. The dye ink preliminary ejection control means controls the number of ejections of dye ink that is not involved in recording ejected from the dye ink ejection port of the recording head to be constant. 2. An ink jet recording apparatus according to 1.   The number of ejections of the dye ink that is not involved in the recording from the dye ink ejection port of the recording head is controlled by the dye ink preliminary ejection control unit so as to change according to the recording conditions. The inkjet recording apparatus according to claim 1. Having recording time detecting means for detecting the time required for recording on one recording medium;
The number of ejections of the dye ink that is controlled by the dye ink preliminary ejection control unit and is not involved in the recording ejected from the ejection port for the dye ink of the recording head is a single recording detected by the recording time detection unit. 4. The inkjet according to claim 3, wherein when the time required for recording on the medium is long, the number of times required for recording on one recording medium detected by the recording time detecting means is set larger than when the time required for recording on one recording medium is short. Recording device.   2. The pigment ink preliminary ejection control means controls the number of ejections of pigment ink not involved in recording ejected from the pigment ink ejection port of the recording head to be constant. 5. The ink jet recording apparatus according to any one of items 1 to 4.   The number of ejections of the pigment ink that is not involved in the recording from the pigment ink ejection port of the recording head is controlled by the pigment ink preliminary ejection control means so as to change according to the recording conditions. An ink jet recording apparatus according to any one of claims 1 to 4. Having recording time detecting means for detecting the time required for recording on one recording medium;
The number of ejections of the pigment ink that is controlled by the pigment ink preliminary ejection control unit and is not involved in the recording ejected from the pigment ink ejection port of the recording head is a single recording detected by the recording time detection unit. 7. The inkjet according to claim 6, wherein when the time required for recording on the medium is long, the time is set longer than when the time required for recording on one recording medium detected by the recording time detecting means is short. Recording device. A recording head having a discharge port for dye ink for discharging dye ink, a discharge port for pigment ink for discharging pigment ink, a transport unit for transporting the recording medium, and transport for transporting the recording medium Scanning means for reciprocating and scanning the recording head in a main scanning direction intersecting the direction, recording medium supply means for supplying the recording medium, and recording medium discharging means for discharging the recording medium, An ink jet recording apparatus that records on a recording medium by ejecting the dye ink and the pigment ink from the recording head, and the recording head records from the dye ink ejection port and the pigment ink ejection port to a place other than the recording medium. In a preliminary discharge method of performing preliminary discharge by discharging dye ink and pigment ink not involved,
Each time the recording head scans a predetermined amount, the recording head is scanned to the outside of the recording medium, and the dye ink not involved in recording is ejected from the recording ink ejection port of the recording head outside the recording medium. Dye ink preliminary discharge control step for controlling preliminary discharge by dye ink,
After the recording on one recording medium is completed, in parallel with the discharge of the recording medium by the recording medium discharging means, the pigment ink which is not involved in the recording discharged for preliminary discharge from the pigment ink discharge port is collected. Pigment ink preliminary ejection control for controlling the preliminary ejection by the pigment ink so that the pigment ink that is not involved in recording is ejected from the pigment ink ejection port of the recording head at the position where the pigment ink is collected by the pigment ink collecting means A preliminary discharge method comprising the steps of:

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