JP2015123635A - Ink discharge type printer, preliminary discharge control method and preliminary discharge control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and properly perform preliminary discharge.SOLUTION: An ink discharge type printer 1 drives a nozzle of a recording head 15 to be moved in a main scanning direction toward a conveyed paper sheet by a head driver 16 and discharges ink drops so as to form images. The ink discharge type printer 1 spends prescribed preliminary discharge time to cause all nozzles to perform preliminary discharge at a paper sheet interval between a previous paper sheet and a next paper sheet of continuously conveyed paper sheets. The ink discharge type printer detects the paper sheet interval by a register sensor 30 in the preliminary discharge, adjusts at least one of non-image formation time conveyance speed of the paper sheet until image formation is started on the next paper sheet after completion of image formation on the previous paper sheet and the preliminary discharge time on the basis of the paper sheet interval, the conveyance speed of the paper sheet and the preliminary discharge time, and performs the preliminary discharge at the paper sheet interval.

Description

  The present invention relates to an ink ejection printing apparatus, a preliminary ejection control method, and a preliminary ejection control program, and more particularly, to an ink ejection printing apparatus, a preliminary ejection control method, and a preliminary ejection control program that efficiently and appropriately perform preliminary ejection. About.

  An ink ejection printing apparatus ejects ink droplets from a plurality of nozzles formed on a recording head onto a recording medium such as paper or film (hereinafter, simply referred to as paper) to form an image.

  Such an ink discharge type printing apparatus discharges ink having viscosity from fine nozzles as ink droplets. Therefore, if the discharge interval between the previous discharge and the next discharge is long, the viscosity of the ink increases. Discharge failure occurs due to drying or the like. When an ink ejection failure occurs in the ink ejection type printing apparatus, pixel omission, shading, etc. occur, and the image quality deteriorates.

  Therefore, conventionally, an ink ejection printing apparatus performs a preliminary ejection process for maintaining ink ejection performance of nozzles by performing preliminary ejection for ejecting ink droplets at regular intervals.

  However, if preliminary ejection is performed at regular intervals, the state of ink at the nozzles is not taken into consideration, and a situation in which wasteful preliminary ejection occurs is generated. Decrease occurs.

  Therefore, conventionally, an inkjet recording apparatus that performs printing by ejecting ink droplets onto a recording medium using a recording head provided with nozzles that eject ink droplets, and calculates the non-operation time of the nozzles. When the sum of the calculation means, the calculation non-operation time until the next operation of the nozzle, and the total non-operation time and the non-operation time exceeds a reference time, the preliminary discharge of the nozzle is performed. There has been proposed an ink jet recording apparatus including a preliminary ejection control unit that performs control so as to be executed (see Patent Document 1).

  In other words, this conventional technology suppresses ink waste by not performing preliminary ejection when the total non-operation time from the previous nozzle operation to the next operation is less than the reference time. The nozzle performance is maintained.

  However, in the prior art described in the above publication, the preliminary discharge is not performed when the total time of the scheduled non-operation time and the non-operation time is less than the reference time. If the determination of whether or not the operation is continued continues, a situation in which the preliminary discharge is not performed for a long time occurs. As a result, there is a possibility that ejection failure may occur due to nozzle drying and ink viscosity increase.

  Accordingly, an object of the present invention is to perform the preliminary discharge efficiently and reliably at an appropriate timing.

  In order to achieve the above object, an ink ejection type printing apparatus according to claim 1, comprising: a conveying unit that conveys a recording medium; and a recording head that includes a nozzle that ejects ink droplets toward the recording medium. A moving unit that moves in a main scanning direction orthogonal to a conveyance direction of the recording medium; a head driving unit that drives the recording head to eject ink droplets from the nozzle; and the recording medium that is continuously conveyed Preliminary ejection for causing the nozzles to perform preliminary ejection by the head driving means in a medium interval between the front recording medium and the rear recording medium in the transport direction of the recording medium, using a preset preliminary ejection time. Means for detecting the interval between the medium, the medium interval, the conveyance speed of the recording medium and the preliminary ejection time, and at least the front side coverage. After the image formation on the recording medium is completed and before the image formation on the rear recording medium is started, at least one of the conveyance speed during non-image formation by the conveyance unit and the preliminary ejection time And preliminary discharge control means for executing preliminary discharge control processing for adjusting the above and causing the preliminary discharge execution means to perform the preliminary discharge during the medium interval.

  According to the present invention, it is possible to perform preliminary discharge efficiently and reliably at an appropriate timing.

1 is a schematic plan view of a printing unit of an ink ejection printing apparatus to which an embodiment of the present invention is applied. 1 is a block diagram of an ink ejection printing apparatus. FIG. 3 is a diagram illustrating a connection state between an ink ejection printing apparatus and a host apparatus. Explanatory drawing of the state in which the front sheet is conveyed to the registration sensor. FIG. 6 is an explanatory diagram of a state in which a rear sheet is conveyed to a registration sensor. FIG. 6 is an explanatory diagram when a paper time interval is longer than a preliminary discharge time. FIG. 6 is an explanatory diagram when a paper time interval is shorter than a preliminary discharge time. FIG. 10 is an explanatory diagram when the paper time interval after changing to the changed conveyance speed is longer than the preliminary ejection time. The flowchart which shows a preliminary discharge control process. FIG. 6 is an explanatory diagram when a paper time interval after changing to a changed conveyance speed is shorter than a preliminary ejection time. 6 is a flowchart illustrating a preliminary discharge control process for calculating a conveyance speed. FIG. 6 is an explanatory diagram when a paper time interval after changing to a calculated conveyance speed is longer than a preliminary ejection time. 10 is a flowchart showing a preliminary discharge control process in which paper conveyance is stopped and preliminary discharge is performed when a calculated conveyance speed is less than an allowable minimum speed. 9 is a flowchart showing a preliminary discharge control process for shortening a preliminary discharge time when the calculated conveyance speed is less than the allowable minimum speed. The figure which shows an example of the print setting screen of a host apparatus. The figure which shows an example of the preliminary discharge control function setting screen of a scanning display part.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, since the Example described below is a suitable Example of this invention, various technically preferable restrictions are attached | subjected, However, The range of this invention is unduly limited by the following description. However, not all the configurations described in the present embodiment are essential constituent elements of the present invention.

  1 to 16 are diagrams showing an embodiment of the ink ejection printing apparatus, the preliminary ejection control method, and the preliminary ejection control program of the present invention. FIG. 1 shows the ink ejection printing apparatus, the preliminary ejection of the present invention. 2 is a schematic plan view of a printing unit 2 of an ink ejection printing apparatus 1 to which an embodiment of a control method and a preliminary ejection control program is applied. FIG.

  In FIG. 1, the ink ejection printing apparatus 1 includes a printing unit 2, and includes a paper feeding unit, a paper discharge unit, an operation display unit 3 (see FIG. 2) and the like (not shown). Although this embodiment will be described with respect to the case where it is applied to the ink ejection type printing apparatus 1, the present invention is similarly applied to an image forming apparatus other than a single printing apparatus such as a composite apparatus. Can do.

  The ink ejection printing apparatus 1 has a slide rail 11 integrally formed with left and right side plates constituting a frame (not shown) extending in the main scanning direction, and the slide rail 11 scans the carriage 12 in the main scanning direction. Supports movement in the direction.

  The carriage 12 is moved in the main scanning direction indicated by a double arrow in FIG. 1 when the timing belt 14 is rotationally driven by the main scanning motor 13.

  The carriage 12 has a recording head 15 mounted thereon, and the recording head 15 discharges four ink droplets for each color of yellow (Y), cyan (C), magenta (M), and black (K). Discharge heads 15Y, 15C, 15M, and 15K are provided. Each of the droplet discharge heads 15Y, 15C, 15M, and 15K includes a nozzle row in which a plurality of nozzles that discharge ink droplets are arranged in the sub-scanning direction that intersects the main scanning direction. Each of the droplet discharge heads 15Y, 15C, 15M, and 15K discharges an ink droplet from each nozzle of each nozzle row toward a lower sheet (recording medium) P. In the present embodiment, the recording head 15 uses independent droplet discharge heads 15Y, 15C, 15M, and 15K. The recording head 15 using a droplet discharge head may be used. Further, the number and the arrangement order of the colors of the ink droplets ejected from the droplet ejection head are not limited to those described above.

  The recording head 15 can use various methods as a pressure generation method for generating a pressure for discharging the droplets. For example, the recording head 15 includes a piezoelectric actuator using a piezoelectric element, a thermal actuator using a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a shape using a metal phase change caused by a temperature change. A memory alloy actuator, an electrostatic actuator using an electrostatic force, or the like can be used.

  The ink ejection printing apparatus 1 includes a head driver 16 (see FIG. 2) such as a driver IC for driving each nozzle of the recording head 15 mounted on the carriage 12. The head driver 16 is connected to a control unit 50 (see FIG. 2) described later via a harness or the like.

  In addition, the ink ejection printing apparatus 1 is provided with an encoder scale 17 in which slits are formed in the main scanning direction in which the carriage 12 moves, as shown in FIG. The carriage 12 is equipped with an encoder sensor 18 composed of a transmissive photosensor that detects a slit of the encoder scale 17. The encoder scale 17 and the encoder sensor 18 as a whole constitute a linear encoder 19 (see FIG. 2) for detecting the position of the carriage 12 in the main scanning direction.

  As shown in FIG. 1, the ink ejection printing apparatus 1 is disposed below the carriage 12 in a state where an endless belt-shaped transport belt 20 is stretched between a pair of transport rollers 21 a and 21 b. The transport belt 20 is rotationally driven by transport rollers 21a and 21b in a sub-scanning direction orthogonal to the moving direction (main scanning direction) of the carriage 12. The conveyance roller 21 a has a driven pulley 22 fixed thereto, and the driven pulley 22 is connected to a driving pulley 23 and a timing belt 24. The driving pulley 23 is connected to the rotation shaft of the sub-scanning motor 25, and the conveyance roller 21 a is rotationally driven via the driving pulley 23, the timing belt 24, and the driven pulley 22 as the sub-scanning motor 25 rotates. . In the ink ejection printing apparatus 1, the conveyance belt 21 is rotated in the conveyance direction when the conveyance roller 21 a is rotationally driven by the sub-scanning motor 25.

  In the ink ejection type printing apparatus 1, a sub-scanning encoder 26 is connected to the transport roller 21 a, and a sub-scanning encoder sensor 27 is disposed in the vicinity of the sub-scanning encoder 26. The sub-scanning encoder sensor 27 detects the rotational position of the sub-scanning encoder 26 that rotates together with the transport roller 21a. The sub-scanning encoder 26 and the sub-scanning encoder sensor 27 constitute a wheel encoder 28 (see FIG. 2) that detects the rotation amount and conveyance amount (paper position) of the conveyance belt 20 as a whole.

  The conveying belt 20 is charged (charged) by a charging roller 29 (see FIG. 2), and a belt having a single layer structure or a plurality of layers (two or more layers) is used. In the case of the single-layer structure, the conveyance belt 20 comes into contact with the paper and the charging roller 29, so that the entire layer is formed of an insulating material. In the case of a multilayer structure, the conveyance belt 20 may be formed of an insulating layer on the side that contacts the paper or the charging roller 29 and may be formed of a conductive layer on the side that does not contact the paper or the charging roller 29. preferable. The surface of the transport belt 20 is charged by the charging roller 29 and sucks and transports the paper P.

  As shown in FIG. 2, the ink ejection printing apparatus 1 includes a control unit 50. The control unit 50 includes a CPU (Central Processing Unit) 51, a ROM (Read Only Memory) 52, and a RAM (Random). Access Memory (53), Non-Volatile Random Access Memory (NVRAM) 54, Application Specific Integrated Circuit (ASIC) 55, I / O (input / output) 56, host I / F (interface) 57, print controller 58, main A scanning motor drive unit 59, an AC bias supply unit 60, a sub-scanning motor drive unit 61, and the like are mounted. In the control unit 50, the respective units 51 to 61 are connected by a bus 62.

  As shown in FIG. 3, the host I / F 57 is connected to a host device HS such as a computer using a communication line L such as USB (Universal Serial Bus), LAN (Local Area Network), and the like, under the control of the CPU 51. Data is transmitted to and received from the host device HS.

  The ROM 52 stores programs such as a basic program as the ink ejection printing apparatus 1 and a preliminary ejection control program of the present invention, system data, and various data necessary for the preliminary ejection control processing. In particular, the ROM 52 stores a sheet conveyance speed and the like used in the preliminary ejection control process of the ink ejection printing apparatus 1.

  The RAM 53 is used as a work memory for the CPU 51 and stores various data necessary for the processing of the CPU 51.

  The NVRAM 54 generally stores initial setting values for each function of the ink ejection printing apparatus 1 and stores various data necessary for the operation of the ink ejection printing apparatus 1 under the control of the CPU 51. The NVRAM 54 stores various data necessary for executing the preliminary ejection control method of the present invention.

  A CPU (preliminary ejection execution unit, preliminary ejection control unit) 51 controls each part of the ink ejection printing apparatus 1 based on a program in the ROM 52 and executes basic processing as the ink ejection printing apparatus 1. Then, the preliminary discharge control method of the present invention is executed.

  That is, the ink ejection type printing apparatus 1 includes a ROM, an EEPROM (Electrically Erasable and Programmable Read Only Memory), an EPROM, a flash memory, a flexible disk, a CD-ROM (Compact Disc Read Only Memory), and a CD-RW (Compact Disc Rewritable). , DVD (Digital Versatile Disk), SD (Secure Digital) card, MO (Magneto-Optical Disc), etc. pre-discharge control program for executing the pre-discharge control method of the present invention recorded on a computer-readable recording medium Is read and introduced into the ROM 52 or the like, and is constructed as an ink ejection control printing apparatus that executes a preliminary ejection control method that performs preliminary ejection, which will be described later, efficiently and reliably at an appropriate timing. This preliminary discharge control program is a computer-executable program written in a legacy programming language such as an assembler, C, C ++, C #, Java (registered trademark) or an object-oriented programming language, and is stored in the recording medium. Can be distributed.

  The ASIC 55 uses the RAM 53 to perform various image processing such as various signal processing and rearrangement on the image data, and outputs the image data to the print control unit 58 as drive data for the recording head 15. Further, the ASIC 55 processes input / output signals for controlling the entire ink ejection printing apparatus 1. Further, the ASIC 55 transmits and receives data necessary for analysis of various image processing modes in the preliminary ejection control method of the present invention, calculation of the sheet conveyance speed in the image processing mode, and the interval between the sheets P (sheet interval). Do.

  As shown in FIG. 3, the host I / F (setting information acquisition means) 57 sends a print job (image data) to the ink ejection printing apparatus 1 to perform printing (image formation) on the ink ejection printing apparatus 1. A host device HS such as a personal computer is connected by a dedicated line or a communication line L such as a LAN (Local Area Network). The host device HS generates image data and a control signal using the printer driver PD installed therein, and transmits the image data and the control signal to the host I / F 57 as a print job. In particular, the host device HS includes input / output devices such as a display, a keyboard, and a mouse, and the setting operation for enabling / disabling the preliminary ejection control processing is performed using the input / output devices. When the host apparatus HS transmits a print job to the ink ejection printing apparatus 1, the printer driver PD that generates the print job enables / disables the preliminary ejection control process according to the operation of the input / output device. The preliminary ejection control processing function setting information is transmitted to the ink ejection type printing apparatus 1 together with the print job. The host I / F 57 passes the print job, preliminary ejection control processing function setting information, and the like received from the host device HS to the CPU 51.

  The print control unit 58 controls the driving of the head driver 16 based on the drive data, and the head driver (head driving unit) 16 controls each droplet discharge head 15Y of the recording head 15 under the control of the print control unit 58. An image is formed on the paper P by ejecting ink droplets corresponding to the image data from the 15C, 15M, and 15K nozzles. In other words, the print control unit 58 generates a drive waveform for driving the recording head 15, and sends image data for selectively driving a pressure generating unit (not shown) of the recording head 15 and various data associated therewith to the head driver 16. Output. The head driver 16 controls the operation of the nozzles of each recording head 15 based on the image data and various data, and causes each nozzle to eject ink droplets. Note that the ink ejection type printing apparatus 1 may generate dot pattern data for outputting an image by storing font data in the ROM 52, for example, or the image data may be output by the printer driver PD on the host device HS side. Although it may be developed into bitmap data and transferred to the ink ejection printing apparatus 1, in the present embodiment, it is described as being performed by the printer driver PD.

  Specifically, the print control unit 58 includes a D / A converter and an amplifier that perform D / A conversion on drive pulse pattern data stored in the ROM 52 and read by the CPU 51, and the like. A drive waveform composed of a pulse or a plurality of drive pulses is output to the head driver 16. The head driver 16 selectively selects drive pulses constituting a drive waveform supplied from the print control unit 58 based on image data (dot pattern data) corresponding to a predetermined number of lines of the recording head 15 input serially. The recording head 15 is driven by applying the pressure to the pressure generating portion of the recording head 15. The head driver 16 has, for example, a shift register for inputting a clock signal and serial data as image data, a latch circuit for latching a register value of the shift register with a latch signal, and an output value of the latch circuit for changing the level. A level conversion circuit (level shifter) and an analog switch array whose on / off is controlled by the level shifter are provided. The head driver 16 selectively applies a required drive pulse included in the drive waveform from the print control unit 58 to the pressure generation unit of the recording head 15 by controlling on / off of the analog switch array.

  The main scanning motor driving unit 59 controls the driving of the main scanning motor 13 under the control of the CPU 51 to control the movement of the carriage 12 in the main scanning direction.

  The main scanning motor (moving means) 13 is driven to rotate, thereby moving the carriage 12 via the timing belt 14 in the main scanning direction indicated by a double arrow in FIG.

  The linear encoder 19 detects the rotation of the main scanning motor 13 and outputs the detection result to the CPU 51 via the I / O 56.

  The AC bias supply unit 60 applies an alternating voltage in which a positive output and a negative output are alternately repeated to the charging roller 29 under the control of the CPU 51. The charging roller 29 alternately charges the conveying belt 20 in a strip shape with a predetermined width in the sub-scanning direction, which is the circumferential direction, by the alternating voltage, in the sub-scanning direction that is the circumferential direction. Since the conveyance belt 20 is alternately charged with plus and minus, the sheet P fed onto the conveyance belt 20 is adsorbed, and the sheet P is conveyed in the sub-scanning direction by circular movement.

  Under the control of the CPU 51, the sub-scanning motor driving unit 61 controls the driving of the sub-scanning motor 25 to control the conveyance of the conveyance belt 20, and the wheel encoder 28 detects the rotation of the sub-scanning motor 25, The data is output to the CPU 51 via the I / O 56.

  The sub-scanning motor (conveying means) 25 is rotationally driven to circulate and convey the conveying belt 20 in the belt conveying direction (sub-scanning direction), and the paper P on the conveying belt 20 in the sub-scanning direction (conveying direction). Transport.

  The operation display unit (setting information acquisition means) 3 includes various operation keys and a display (for example, a liquid crystal display). The operation display unit 3 performs various operations necessary to operate the ink ejection printing apparatus 1 from the operation keys, and performs various operations to be notified to the operator from the operation keys and the ink ejection printing apparatus 1 on the display. Display information. In particular, the operation display unit 3 outputs various information necessary for the preliminary discharge control processing of the present invention to the display under the control of the CPU 51, and performs various instruction operations input from operation keys or a touch panel of the display. The contents are notified to the CPU 51. The operation display unit 3 is used for a setting operation for enabling / disabling the preliminary discharge control processing function, acquires the setting content, and outputs the setting content to the CPU 51 as preliminary discharge control processing function setting information.

  The ink ejection printing apparatus 1 includes a registration sensor 30 that detects the paper P conveyed from the paper supply unit onto the conveyance belt 20, and the registration sensor (medium interval detection unit) 30 includes at least the paper. The front end and rear end of P are detected, and the detection result is output to the CPU 51 via the I / O 56. In particular, the registration sensor 30 has a sheet interval (medium) between the front sheet P (hereinafter referred to as the front sheet P) and the rear sheet P (hereinafter referred to as the next sheet P) of the continuously transported sheets P. (Interval) X is detected and output to the CPU 51.

  As shown in FIGS. 4 and 5, the ink ejection printing apparatus 1 is provided with a maintenance unit 31 outside the image forming area in the main scanning direction. The ink discharge printing apparatus 1 includes a maintenance unit 31 that performs preliminary discharge from each nozzle of the recording head 15 and droplet discharge heads 15Y, 15C, 15M, and 15K on the carriage 12 that has moved to the maintenance unit 31. Perform maintenance such as capping.

  Next, the operation of this embodiment will be described. The ink ejection printing apparatus 1 according to the present embodiment performs preliminary ejection efficiently and reliably at an appropriate timing.

  That is, for example, when a print job is sent from the host apparatus HS and the host I / F 57 captures the ink ejection printing apparatus 1, the captured image data is temporarily stored in the RAM 53. The CPU 41 converts the image data in the RAM 53 into image data (for example, drawing data) in a format that can be processed by the head driver 16 and develops the image data in the RAM 53. In the ink ejection printing apparatus 1, when there is a print request, the print control unit 58 gives the head driver 16 images corresponding to the number of nozzles of the droplet ejection heads 15Y, 15C, 15M, and 15K of the recording head 15. Transfer data.

  As shown in FIG. 4, when the sheet P is sent from the sheet feeding unit onto the conveyance belt 20 and the registration sensor 30 detects the leading edge of the sheet P, the CPU 51 passes through the main scanning motor driving unit 59. The main scanning motor 13 is driven to start the movement of the carriage 12 in the main scanning direction.

  The CPU 51 detects the transport position of the paper P and the main scanning position of the carriage 12 based on detection signals from the wheel encoder 28 and the linear encoder 19. When the paper P is conveyed to the image formation start position, the CPU 51 drives the head driver 16 via the print control unit 58 to set the nozzles of the droplet discharge heads 15Y, 15C, 15M, and 15K of the recording head 15. The image is formed on the paper P by driving.

  Then, as the image formation on the preceding paper P of the paper P that is continuously conveyed proceeds, the ink ejection printing apparatus 1 sets the next paper P to a preset paper interval X as shown in FIG. The paper is transported from the paper feeding unit onto the transport belt 20 with a gap. In the ink ejection type printing apparatus 1, the registration sensor 30 detects the next sheet P.

  On the other hand, the ink ejection printing apparatus 1 maintains the carriage 12 before starting the printing on the previous paper P and at the paper interval X from the end of printing on the previous paper P to the start of printing on the next paper P. Move to section 31. When the carriage 12 moves to the maintenance unit 31, the CPU 51 outputs a drive signal for preliminary ejection to the head driver 16 via the print control unit 58 and drives all the nozzles to perform preliminary ejection. The preliminary ejection time Ty, which is the time necessary to execute this preliminary ejection, is a preset time.

  When the CPU 51 forms an image on a plurality of sheets P from the analysis result of the print job, the previous sheet P and the next sheet P are usually conveyed with a preset sheet interval X. In this case, the CPU 51 determines the non-image forming conveyance speed V until at least the image formation on the next sheet P is started after the image formation on the previous sheet P is completed. The CPU 51 controls the rotation speed of the sub-scanning motor 25 via the sub-scanning motor driving unit 61 to rotate the conveyance belt 20 at the non-image forming conveyance speed V.

  The paper time interval Td between the previous paper P and the next paper P at this time is obtained by the following equation (1).

Td = X / V (1)
Then, as shown in FIG. 6, when an image is formed on a plurality of sheets P, if the preliminary ejection time Ty is shorter than the paper time interval Td (Ty <Td), the CPU 51 reserves within the paper time interval Td. It is determined that ejection can be performed, and the paper P is conveyed at the paper time interval Td. That is, the CPU 51 continues the transport of the next paper P as it is when the printing (image formation) of the previous paper P is completed without changing the transport speed V during non-image formation of the paper P. Print (image formation). Even when the preliminary ejection time Ty is the same as the paper time interval Td, the CPU 51 may determine that the preliminary ejection can be performed within the paper time interval Td.

  However, as shown in FIG. 7, when the preliminary ejection time Ty is longer than the paper time interval Td (Ty <Td), the CPU 51 determines that the preliminary ejection cannot be performed within the paper time interval Td. In this case, as shown in FIG. 8, when the printing on the front sheet P is completed, the CPU 51 switches the non-image forming conveyance speed V to a preset slow changed conveyance speed (low conveyance speed) V2, The conveyor belt 20 is driven to perform preliminary discharge. When the preliminary ejection is completed, the CPU 51 performs the normal printing by transporting the next sheet P as usual.

  In this case, the changed paper time interval Td2 due to the slow changed conveyance speed V2 is obtained by Td2 = X / V2, similarly to the equation (1), and is longer than the preliminary ejection time Ty (Ty <Td2).

  That is, as shown in FIG. 9, when the registration sensor 30 detects the trailing edge of the front sheet P (step S101), the CPU 51 starts measuring the sheet interval X by the wheel encoder 28.

  Next, when the registration sensor 30 detects the leading edge (leading edge) of the next sheet P (step S102), the CPU 51 determines the sheet interval X (step S103) and waits for the printing of the preceding sheet P to be completed (step S104). ).

  When the printing of the previous paper P is completed, the CPU 51 acquires the preliminary ejection time Ty from the ROM 52 or the NVRAM 54 (step S105), and determines whether the preliminary ejection time Ty is longer than the paper time interval Td (= X / V) ( Step S106).

  In step S106, as shown in FIG. 7, when the preliminary ejection time Ty is longer than the paper time interval Td (YES in step S106), the CPU 51 performs preliminary ejection on the paper interval X (paper time interval Td). It is determined that it cannot be executed within. In this case, the CPU 51 changes the non-image-forming conveyance speed V of the paper P to a preset changed conveyance speed V2 (step S107). When the CPU 51 changes the non-image forming transport speed V to the changed transport speed V2, the CPU 51 executes a preliminary ejection operation while transporting the paper P at the changed transport speed V2 (step S108). In this case, the changed paper time interval Td2 (= X / V2) at the changed conveyance speed V2 is longer than the preliminary discharge time Ty as shown in FIG. 8, and the preliminary discharge is performed within the changed paper time interval Td2, that is, It can be executed within the paper interval X.

  In step S106, as shown in FIG. 6, when the preliminary ejection time Ty is equal to or shorter than the paper time interval Td (NO in step S106), the CPU 51 performs preliminary ejection on the paper interval X (paper time interval Td). Therefore, the preliminary ejection operation is performed without changing the conveyance speed (step S108).

  When the preliminary ejection operation is completed, the CPU 51 starts printing on the next sheet P by a normal operation, and thereafter performs the same processing (step S109).

  Therefore, the ink ejection printing apparatus 1 according to the present embodiment can efficiently perform the preliminary ejection at an appropriate timing.

  In addition, the ink ejection printing apparatus 1 of the present embodiment can appropriately perform preliminary ejection during the paper interval X by adjusting the conveyance speed of the paper P, and efficiently perform preliminary ejection. , Can be carried out reliably at an appropriate timing.

  As described above, when the preliminary ejection time Ty is longer than the paper time interval Td, even if the transport speed V during non-image formation of the paper P is changed to the changed transport speed V2, as shown in FIG. When the preliminary ejection time Ty is longer than the changed paper time interval Td2, as shown in FIG. 11, the transport speed of the paper P that can reliably perform preliminary ejection at the paper interval X is calculated. In FIG. 11, the same step numbers are assigned to the same processing steps as in FIG. 9, and the description thereof is simplified.

  That is, as shown in FIG. 11, when the registration sensor 30 detects the trailing edge of the front sheet P (step S101), the CPU 51 starts measuring the sheet interval X by the wheel encoder 28.

  Next, when the registration sensor 30 detects the leading edge (leading edge) of the next sheet P (step S102), the CPU 51 determines the sheet interval X (step S103) and waits for the printing of the preceding sheet P to be completed (step S104). ).

  When the printing of the previous paper P is completed, the CPU 51 acquires the preliminary ejection time Ty (step S105), and determines whether the preliminary ejection time Ty is longer than the paper time interval Td (= X / V) (step S106).

  If the preliminary ejection time Ty is longer than the paper time interval Td in step S106, the CPU 51 changes the non-image forming transport speed V of the paper P to the preset transport speed V2 (step S107).

  When the CPU 51 changes the transport speed V during non-image formation to the changed transport speed V2, the CPU 51 determines whether the preliminary ejection time Ty is longer than the changed paper time interval Td2 (Td2 = X / V2) based on the changed transport speed V2 (step). S201).

  When the preliminary ejection time Ty is longer than the changed paper time interval Td2 in step S201 (when YES in step S201), the CPU 51 can carry out preliminary ejection within the paper interval X reliably. V is calculated as the calculated transport speed V3 (step S202). That is, the CPU 51 calculates a calculated transport speed V3 (Ty <(X / V3) = Td3) at which the calculated paper time interval Td3 obtained by dividing the paper interval X by the calculated transport speed V3 is less than the preliminary ejection time Ty. .

  When calculating the calculated transport speed V3, the CPU 51 changes the transport speed of the paper P to the calculated transport speed V3 (step S203) and executes a preliminary ejection operation (step S108). In this case, the calculated paper time interval Td3 at the calculated transport speed V3 is shorter than the preliminary ejection time Ty as shown in FIG. Accordingly, the preliminary ejection can be executed within the changed paper time interval Td3.

  When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  In step S201, if the preliminary ejection time Ty is shorter than or the same as the changed paper time interval Td2 (NO in step S201), the CPU 51 executes the preliminary ejection within the paper time interval Td. Judge that you can. The CPU 51 changes the transport speed V during non-image formation to the changed transport speed V2 and performs the preliminary ejection operation while transporting the next sheet P (step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  Further, when the preliminary discharge time Ty is equal to or shorter than the paper time interval Td by the CPU 106 (NO in step S106), the CPU 51 determines that the preliminary discharge can be executed within the paper time interval Td. In this case, the CPU 51 continues the transport of the next sheet P without changing the transport speed V at the non-image forming transport speed V, and executes the preliminary ejection operation (step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  In the above description, the calculated transport speed V3 is calculated when the preliminary ejection time Ty is longer than the paper P transport speed Td2 at the changed transport speed V2. The calculation of the calculated conveyance speed V3 is not limited to the above case, and for example, it may be calculated when the preliminary ejection time Ty is longer than the paper time interval Td.

  Therefore, the ink ejection printing apparatus 1 according to the present embodiment can appropriately perform the preliminary ejection during the paper interval X (paper time interval Td) by adjusting the conveyance speed of the paper P. Can be implemented efficiently and reliably at an appropriate timing.

  Further, the ink ejection printing apparatus 1 according to the present embodiment calculates the calculated transport speed V3, and at least during the paper interval X, the next paper P is transported at the calculated transport speed V3, so that the transport speed of the paper P is increased. Thus, the preliminary ejection can be appropriately performed during the paper time interval Td. As a result, preliminary ejection can be performed efficiently and reliably at an appropriate timing.

  When the calculated transport speed V3 is less than the preset minimum allowable transport speed Vs when the calculated transport speed V3 is calculated, the ink ejection printing apparatus 1 transports the paper P as shown in FIG. You may stop and perform preliminary discharge. In FIG. 13, the same processing steps as those in FIG. 11 are given the same step numbers to simplify the description.

  That is, as shown in FIG. 13, when the registration sensor 30 detects the trailing edge of the front sheet P (step S101), the CPU 51 starts measuring the sheet interval X by the wheel encoder 28. Next, when the registration sensor 30 detects the leading edge (leading edge) of the next sheet P (step S102), the CPU 51 determines the sheet interval X (step S103) and waits for the printing of the preceding sheet P to be completed (step S104). ). When the printing of the previous paper P is completed, the CPU 51 acquires the preliminary ejection time Ty (step S105), and determines whether the preliminary ejection time Ty is longer than the paper time interval Td (= X / V) (step S106).

  If the preliminary ejection time Ty is longer than the paper time interval Td in step S106, the CPU 51 changes the non-image forming transport speed V of the paper P to the preset transport speed V2 (step S107).

  When the CPU 51 changes the transport speed V during non-image formation to the changed transport speed V2, the CPU 51 determines whether the preliminary ejection time Ty is longer than the changed paper time interval Td2 (Td2 = X / V2) based on the changed transport speed V2 (step). S201).

  If the preliminary ejection time Ty is longer than the changed paper time interval Td2 in step S201, the CPU 51 calculates the transport speed V during non-image formation of the paper P that can reliably perform the preliminary ejection within the paper interval X. Calculated as V3 (Ty <(X / V3)) (step S202).

  When calculating the calculated transport speed V3, the CPU 51 checks whether the calculated transport speed V3 is equal to or higher than a preset minimum allowable transport speed Vs (step S301). The minimum allowable transport speed Vs is set in advance as a transport speed at which the preliminary ejection time Ty is longer than the calculated paper time interval Td3 based on the calculated transport speed V3 while appropriately transporting the paper P. The ROM 52 and the NVRAM 54 Etc. are stored.

  If the calculated transport speed V3 is equal to or greater than the minimum allowable transport speed Vs in step S301 (YES in step S3201), the CPU 51 changes the transport speed of the next sheet P to the calculated transport speed V3 (step S203). A preliminary discharge operation is executed (step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  If the calculated transport speed V3 is less than the minimum allowable transport speed Vs in step S301 (NO in step S301), the CPU 51 stops transporting the paper P (step S302).

  The CPU 51 performs preliminary ejection in a state where the conveyance of the paper P is stopped (step S108). When the preliminary ejection is completed, the CPU 51 starts normal conveyance of the next paper P and starts normal printing. (Step S109). Therefore, even when the calculated conveyance speed V3 is less than the minimum allowable conveyance speed Vs, it is possible to reliably perform the preliminary discharge while appropriately performing image formation.

  In step S201, if the preliminary ejection time Ty is shorter than or equal to the changed paper time interval Td2, the CPU 51 determines that the preliminary ejection can be executed within the paper time interval Td2. In this case, the CPU 51 changes the transport speed V during non-image formation to the paper transport speed V2, and performs the preliminary ejection operation while transporting the next paper P (step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  Further, when the CPU 106 determines that the preliminary ejection time Ty is equal to or less than the paper time interval Td, the CPU 51 determines that the preliminary ejection can be executed within the paper time interval Td, and changes the transport speed V during non-image formation. The preliminary discharge operation is executed without performing (step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  Therefore, if the calculated transport speed V3 is less than the minimum allowable transport speed Vs, the transport of the next sheet P is stopped during the preliminary discharge time Ty, and the preliminary discharge is appropriately and reliably performed during the paper time interval Td. Can be implemented. As a result, preliminary ejection can be performed efficiently and reliably at an appropriate timing.

  Furthermore, when the calculated transport speed V3 is less than the preset minimum allowable transport speed Vs when the calculated transport speed V3 is calculated, the ink ejection printing apparatus 1 of the present embodiment, as shown in FIG. The discharge time Ty may be shortened. In FIG. 14, the same processing steps as those in FIG. 13 are given the same step numbers to simplify the description.

  That is, as shown in FIG. 14, when the registration sensor 30 detects the trailing edge of the front sheet P (step S101), the CPU 51 starts measuring the sheet interval X by the wheel encoder 28. Next, when the registration sensor 30 detects the leading edge (leading edge) of the next sheet P (step S102), the CPU 51 determines the sheet interval X (step S103) and waits for the printing of the preceding sheet P to be completed (step S104). ). When the printing of the previous paper P is completed, the CPU 51 acquires the preliminary ejection time Ty (step S105), and determines whether the preliminary ejection time Ty is longer than the paper time interval Td (= X / V) (step S106).

  If the preliminary ejection time Ty is longer than the paper time interval Td in step S106, the CPU 51 changes the non-image forming transport speed V of the paper P to the preset transport speed V2 (step S107).

  When the CPU 51 changes the transport speed V during non-image formation to the changed transport speed V2, the CPU 51 determines whether the preliminary ejection time Ty is longer than the changed paper time interval Td2 based on the changed transport speed V2 (step S201).

  If the preliminary ejection time Ty is longer than the changed paper time interval Td2 in step S201, the CPU 51 calculates the transport speed V during non-image formation of the paper P that can reliably perform the preliminary ejection within the paper interval X. Calculated as V3 (Ty <(X / V3)) (step S202).

  When calculating the calculated transport speed V3, the CPU 51 checks whether the calculated transport speed V3 is equal to or higher than a preset minimum allowable transport speed Vs (step S301).

  If the calculated transport speed V3 is equal to or higher than the minimum allowable transport speed Vs in step S301, the CPU 51 changes the non-image forming transport speed V of the next sheet P to the calculated transport speed V3 (step S203), and performs the preliminary ejection operation. Execute (Step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  In step S301, if the calculated transport speed V3 is less than the minimum allowable transport speed Vs, the CPU 51 calculates a calculated preliminary discharge time Ty2 in which the preliminary discharge is completed within the paper time interval Td3 based on the calculated transport speed V3. That is, the CPU 51 calculates the calculated preliminary discharge time Ty2 that satisfies Td3 (= X / V3)> Ty2. When calculating the calculated preliminary discharge time Ty2, the CPU 51 sets the shortened calculated preliminary discharge time Ty2 as the preliminary discharge time Ty, and executes the preliminary discharge for the preliminary discharge time Ty (step S108). When the preliminary ejection is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109). Therefore, even when the calculated conveyance speed V3 is less than the minimum allowable conveyance speed Vs, the preliminary ejection can be reliably performed while shortening the preliminary ejection time and appropriately performing image formation.

  Furthermore, in step S201, if the preliminary ejection time Ty is shorter than or the same as the changed paper time interval Td2, the CPU 51 determines that the preliminary ejection can be executed within the paper time interval Td, and the preliminary ejection time Ty. The operation is executed (step S108). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  If the CPU 106 determines that the preliminary discharge time Ty is equal to or shorter than the paper time interval Td, the CPU 51 determines that the preliminary discharge can be executed within the paper time interval Td, and executes the preliminary discharge operation (step S108). ). When the preliminary ejection operation is completed, the CPU 51 starts normal printing on the next sheet P, and thereafter performs the same processing (step S109).

  Therefore, if the calculated transport speed V3 is less than the minimum allowable transport speed Vs, the calculated preliminary discharge time Ty shorter than the current preliminary discharge time Ty is calculated, and the preliminary discharge is performed using the calculated preliminary discharge time Ty2. Can do. As a result, preliminary ejection can be performed efficiently and reliably at an appropriate timing.

  Note that the ink ejection printing apparatus 1 appropriately uses the operation of the host device HS or the operation display unit 3 of the ink ejection printing apparatus 1 for the preliminary ejection control processing function for controlling the preliminary ejection. Enable / disable can be set.

  That is, for example, as shown in FIG. 15, the host device HS displays a preliminary ejection control processing function on a print setting screen G1 that the printer driver PD displays on a display or the like so that the user can perform print settings for a print job. Display check items to enable / disable. In FIG. 15, a check box is displayed in the check item of the preliminary discharge control function, and when the check box is checked, the printer driver PD incorporates information for enabling the preliminary discharge control function into the print job. And transmitted to the ink ejection printing apparatus 1. That is, the printer driver PD incorporates preliminary ejection control processing function setting information corresponding to the setting content set on the print setting screen G1 into the print job, and transmits it to the ink ejection printing apparatus 1.

  In the ink ejection printing apparatus 1, the host I / F 57 receives (acquires) a print job in which the preliminary ejection control processing function setting information is incorporated and passes it to the CPU 51. When analyzing the print job, the CPU 51 analyzes the preliminary ejection control processing function setting information and performs processing according to the setting contents of the preliminary ejection control processing function setting information. FIG. 15 shows a state in which the check box for the preliminary ejection control function is not checked.

  In addition, as shown in FIG. 16, the ink ejection printing apparatus 1 displays the preliminary ejection control function setting screen G <b> 2 on the display of the operation display unit 3, and the user sets whether to enable / disable the preliminary ejection control processing function. Make it possible. Note that the preliminary discharge control function setting screen G2 in FIG. 16 shows a case where the “OK” button is pressed when the preliminary discharge control function is enabled, and the “CA” button is pressed when the preliminary discharge control function is disabled. .

  Therefore, the user can appropriately set the validity / invalidity of the preliminary ejection control function according to the availability of the ink ejection type printing apparatus 1, the contents of the print setting information of the print job, the required quality of the formed image, and the like. It is possible to improve usability.

  As described above, the ink ejection printing apparatus 1 according to the present embodiment includes the sub-scanning motor (conveying unit) 25 that conveys the paper (recording medium) P and the nozzle that ejects ink droplets toward the paper P. A main scanning motor (moving means) 13 that moves the recording head 15 in a main scanning direction orthogonal to the conveyance direction of the paper P, and a head driver (head driving) that drives the recording head 15 to eject ink droplets from the nozzles. Means) 16 and a sheet interval (medium interval) X between the front sheet (front sheet) P and the next sheet (rear sheet) P in the transport direction of the continuously transported sheet P are set in advance. A CPU (preliminary ejection execution means) 51 for preliminarily ejecting all the nozzles by the head driver 16 using a preliminary ejection time Ty, and a registration sensor (medium interval detection) for detecting the paper interval X Means) 30 and after the image formation on the previous paper P is completed at least after the image formation on the previous paper P is started based on the paper interval X, the conveyance speed of the paper P and the preliminary ejection time Ty. The sub-scanning motor 25 adjusts at least one of the transport speed V during non-image formation and the preliminary ejection time Ty, and the preliminary ejection is performed during the paper interval X to the CPU 51 as the preliminary ejection execution means. CPU (preliminary discharge control means) 51 for executing preliminary discharge control processing.

  Therefore, by adjusting either the conveyance speed of the paper P or the preliminary discharge time Ty, the preliminary discharge can be performed within the paper interval X, and the preliminary discharge is efficiently and reliably performed at an appropriate timing. Can be implemented.

  Further, the ink ejection printing apparatus 1 of the present embodiment includes a transport processing step for transporting a paper (recording medium) P and a recording head 15 equipped with a nozzle for ejecting ink droplets toward the paper P. A movement processing step for moving in the main scanning direction orthogonal to the P conveyance direction, a head drive processing step for driving the recording head 15 to eject ink droplets from the nozzles, and conveyance of the continuously conveyed paper P A preliminary discharge execution processing step in which a preliminary discharge time Ty that is set in advance is consumed at a paper interval X between the previous paper P and the next paper P in the direction, and preliminary discharge is performed on all the nozzles by the head driving processing step; Based on the medium interval detection processing step for detecting the sheet interval X, the sheet interval X, the conveyance speed of the sheet P, and the preliminary ejection time Ty, In both cases, after the image formation on the previous paper P is completed and before the image formation on the next paper P is started, the non-image-forming transport speed V and the preliminary ejection time Ty in the transport processing step. At least one of them is adjusted, and a preliminary ejection control method is performed, which includes a preliminary ejection control processing step for causing the preliminary ejection execution processing step to perform the preliminary ejection during the sheet interval.

  Therefore, by adjusting either the conveyance speed of the paper P or the preliminary discharge time Ty, the preliminary discharge can be performed within the paper interval X, and the preliminary discharge is efficiently and reliably performed at an appropriate timing. Can be implemented.

  Furthermore, the ink ejection printing apparatus 1 according to the present exemplary embodiment includes a recording process in which a control process such as the CPU 51 includes a transport process for transporting the paper (recording medium) P and a nozzle for ejecting ink droplets toward the paper P. The head 15 is transported continuously with a moving process for moving in the main scanning direction orthogonal to the transport direction of the paper P, and a head driving process for driving the recording head 15 to eject ink droplets from the nozzles. Preliminary ejection execution processing for preliminarily ejecting all the nozzles by the head driving process at a paper spacing X between the previous paper P and the next paper P in the transport direction of the paper P and using a preset preliminary ejection time Ty. And a medium interval detection process for detecting the sheet interval X, the sheet interval X, the conveyance speed of the sheet P, and the preliminary ejection time Ty, After the image formation on P is completed, at least one of the non-image forming conveyance speed V by the conveyance process and the preliminary ejection time Ty until the image formation on the next sheet P is started. A preliminary discharge control program for executing a preliminary discharge control process for adjusting and performing the preliminary discharge control process for performing the preliminary discharge during the paper interval in the preliminary discharge execution process is installed.

  Therefore, by adjusting either the conveyance speed of the paper P or the preliminary discharge time Ty, the preliminary discharge can be performed within the paper interval X, and the preliminary discharge is efficiently and reliably performed at an appropriate timing. Can be implemented.

  Further, in the ink ejection type printing apparatus 1 according to the present embodiment, the CPU 51 as the preliminary ejection control unit performs at least the preliminary ejection control process when the preliminary ejection is not completed within the sheet interval X. The conveyance speed V during non-image formation is adjusted to a predetermined changed conveyance speed (low conveyance speed) V2 that is slower than the current conveyance speed V during non-image formation.

  Therefore, it is possible to easily adjust the conveyance speed of the paper P and appropriately perform the preliminary discharge during the paper interval X, and simply and reliably perform the preliminary discharge at an appropriate timing. Can be implemented.

  Further, in the ink ejection type printing apparatus 1 according to the present embodiment, the CPU 51 as the preliminary ejection control unit performs the preliminary ejection control processing when the preliminary ejection is not completed within the sheet interval X. Based on the sheet interval X and the preliminary ejection time Ty, a calculated transport speed (low transport speed) V3 slower than the current transport speed V during non-image formation is calculated, and the transport speed V during non-image formation is calculated and transported. The speed is adjusted to the speed V3.

  Therefore, the conveyance speed of the paper P can be adjusted according to the paper interval X and the preliminary discharge time Ty, and the preliminary discharge can be more appropriately performed during the paper interval X. It can be carried out efficiently and surely at a more appropriate timing.

  Further, in the ink ejection type printing apparatus 1 according to the present embodiment, the CPU 51 as the preliminary ejection control unit performs the preliminary paper P as the preliminary ejection control process at least during the preliminary ejection in the paper interval X. Stop the transport of.

  Therefore, the conveyance of the paper P can be stopped, and the preliminary discharge can be performed more reliably during the paper interval X, and the preliminary discharge can be easily and efficiently performed at an appropriate timing. can do.

  Furthermore, in the ink ejection type printing apparatus 1 of the present embodiment, when the CPU 51 as the preliminary ejection control unit calculates the low conveyance speed V3 as less than the predetermined minimum conveyance speed Vl as the preliminary ejection control process, In the paper interval X, the conveyance of the next paper P is stopped at least during the preliminary discharge.

  Therefore, the conveyance of the paper P can be stopped only when necessary, and the preliminary discharge can be more reliably performed during the paper interval X, and the preliminary discharge can be performed more efficiently and appropriately. It can be carried out reliably at the timing.

  Further, in the ink ejection type printing apparatus 1 according to the present embodiment, the CPU 51 as the preliminary ejection control unit performs the preliminary ejection control processing when the preliminary ejection is not completed within the sheet interval X. Based on the sheet interval X and the preliminary discharge time Ty, a calculated preliminary discharge time (shortened preliminary discharge time) Ty2 shorter than the current preliminary discharge time Ty is calculated, and the preliminary discharge time Ty is calculated as the calculated preliminary discharge time Ty2. Adjust the time.

  Therefore, only when necessary, the preliminary ejection time can be adjusted according to the paper interval X and the preliminary ejection time Ty, and the preliminary ejection can be reliably performed during the paper interval X, so that the preliminary ejection is efficient. In addition, it can be carried out reliably at an appropriate timing.

  Furthermore, the ink ejection printing apparatus 1 according to the present embodiment further includes setting information acquisition means such as a host I / F 57 for acquiring the setting information for valid / invalid of the preliminary ejection control processing function, the operation display unit 3, and the like. The CPU 51 as the preliminary discharge control means executes the preliminary discharge control process only when the preliminary discharge control processing function is set to be effective according to the setting information acquired by the setting information acquisition means.

  Therefore, the user can appropriately set the validity / invalidity of the preliminary ejection control function according to the availability of the ink ejection type printing apparatus 1, the contents of the print setting information of the print job, the required quality of the formed image, and the like. It is possible to improve usability.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to that described in the above embodiments, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

DESCRIPTION OF SYMBOLS 1 Ink discharge type printer 2 Printing part 3 Operation display part 11 Slide rail 12 Carriage 13 Main scanning motor 14 Timing belt 15 Recording head 15Y, 15C, 15M, 15K Droplet discharge head 16 Head driver 17 Encoder scale 18 Encoder sensor 19 Linear Encoder 20 Conveying belt 21a, 21b Conveying roller 22 Driven pulley 23 Drive pulley 24 Timing belt 25 Sub-scanning motor 26 Sub-scanning encoder 27 Sub-scanning encoder sensor 28 Wheel encoder 29 Charging roller 30 Registration sensor 31 Maintenance unit 50 Control unit 51 CPU
52 ROM
53 RAM
54 NVRAM
55 ASIC
56 I / O
57 Host I / F
58 Print Control Unit 59 Main Scan Motor Drive Unit 60 AC Bias Supply Unit 61 Sub Scan Motor Drive Unit 62 Bus P Paper L Communication Line HS Host Device PD Printer Driver G1 Print Setting Screen G2 Preliminary Discharge Control Function Setting Screen

JP 2006-142840 A

Claims (9)

Conveying means for conveying a recording medium;
A moving means for moving a recording head equipped with a nozzle for ejecting ink droplets toward the recording medium in a main scanning direction orthogonal to the conveying direction of the recording medium;
Head driving means for driving the recording head to eject ink droplets from the nozzles;
In the medium interval between the front recording medium and the rear recording medium in the conveyance direction of the recording medium that is continuously conveyed, a predetermined preliminary discharge time is spent in the medium interval between the recording medium and the recording medium. Preliminary discharge execution means for causing the nozzle to perform preliminary discharge;
Medium interval detecting means for detecting the medium interval;
Based on the medium interval, the transport speed of the recording medium, and the preliminary discharge time, at least after the image formation on the front recording medium is completed, the image formation on the rear recording medium is started. The preliminary discharging unit adjusts at least one of the conveying speed during non-image formation by the conveying unit and the preliminary discharge time until the preliminary discharging is performed during the medium interval. Preliminary discharge control means for executing discharge control processing;
An ink-jet printing apparatus comprising: The preliminary discharge control means includes
As the preliminary ejection control process, when the preliminary ejection is not completed within the medium interval, at least the transport speed at the time of non-image formation is set to a predetermined low transport speed that is slower than the current transport speed at the time of non-image formation. The ink discharge printing apparatus according to claim 1, wherein the speed is adjusted to a predetermined speed. The preliminary discharge control means includes
As the preliminary ejection control process, when the preliminary ejection is not completed within the medium interval, the low conveyance is slower than the current non-image-forming conveyance speed based on the medium interval and the preliminary ejection time. 2. The ink ejection printing apparatus according to claim 1, wherein a speed is calculated and the transport speed during non-image formation is adjusted to the low transport speed. The preliminary discharge control means includes
2. The ink ejection printing apparatus according to claim 1, wherein, as the preliminary ejection control processing, conveyance of the rear recording medium is stopped at least during the preliminary ejection in the medium interval. . The preliminary discharge control means includes
As the preliminary ejection control process, when the calculated low transport speed is less than a predetermined minimum transport speed, the rear recording medium is transported at least during the preliminary ejection in the medium interval. The ink ejection printing apparatus according to claim 3, wherein the ink ejection printing apparatus is stopped. The preliminary discharge control means includes
As the preliminary ejection control process, when the preliminary ejection is not completed within the medium interval, a shortened preliminary ejection time shorter than the current preliminary ejection time is set based on the medium interval and the preliminary ejection time. The ink ejection printing apparatus according to claim 1, wherein the preliminary ejection time is calculated and the time is adjusted to the shortened preliminary ejection time. The ink ejection type printing apparatus comprises:
A setting information acquisition means for acquiring setting information for valid / invalid of the preliminary ejection control processing function;
The preliminary discharge control means includes
7. The preliminary ejection control process is executed only when the preliminary ejection control processing function is set to be effective in the setting information acquired by the setting information acquisition unit. The ink ejection type printing apparatus according to any one of the above. A transport processing step for transporting a recording medium;
A movement processing step of moving a recording head equipped with a nozzle for discharging ink droplets toward the recording medium in a main scanning direction orthogonal to the conveying direction of the recording medium;
A head drive processing step of driving the recording head to eject ink droplets from the nozzles;
In the medium interval between the front recording medium and the rear recording medium in the transport direction of the recording medium that is continuously transported, a preset preliminary discharge time is spent, and the head driving processing step A preliminary discharge execution processing step for performing preliminary discharge on all nozzles;
A medium interval detection processing step for detecting the medium interval;
Based on the medium interval, the transport speed of the recording medium, and the preliminary discharge time, at least after the image formation on the front recording medium is completed, the image formation on the rear recording medium is started. The preliminary ejection is performed during the medium interval in the preliminary ejection execution processing step by adjusting at least one of the transport speed at the time of non-image formation by the transport processing step and the preliminary ejection time. A preliminary discharge control processing step,
A preliminary discharge control method comprising: To the control processor,
A transport process for transporting a recording medium;
A moving process for moving a recording head equipped with a nozzle for ejecting ink droplets toward the recording medium in a main scanning direction orthogonal to the conveying direction of the recording medium;
A head driving process for driving the recording head to eject ink droplets from the nozzles;
In the medium interval between the front recording medium and the rear recording medium in the transport direction of the recording medium that is continuously transported, a pre-discharge time set in advance is used, and the head driving process performs the total recording. A preliminary discharge execution process for causing the nozzle to perform preliminary discharge;
A medium interval detection process for detecting the medium interval;
Based on the medium interval, the transport speed of the recording medium, and the preliminary discharge time, at least after the image formation on the front recording medium is completed, the image formation on the rear recording medium is started. The preliminary discharge is performed during the medium interval by adjusting at least one of the conveyance speed at the time of non-image formation by the conveyance process and the preliminary discharge time until the preliminary discharge is performed. Discharge control processing;
A pre-discharge control program characterized by causing

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