JP7589464B2 - Image forming apparatus and program - Google Patents

Description

The present invention relates to an image forming device and a program.

Conventionally, in image forming devices that eject liquid to form an image on a recording medium, a technique is known in which the location where the idle ejection that does not contribute to the image is performed is switched depending on the amount of liquid stored in that location.

In addition, in order to prevent the image forming device from ceasing operation when the liquid stored in the location where the blank ejection is performed becomes full, a configuration has been disclosed in which the location where the blank ejection is performed is set from among a number of predetermined locations (see, for example, Patent Document 1).

However, with the technology of Patent Document 1, the mist generated when performing blank ejection may contaminate the image forming device or recording medium.

The objective of the present invention is to suppress mist.

An image forming apparatus according to one aspect of the present invention is an image forming apparatus that ejects liquid to form an image on a recording medium, and includes a plurality of liquid ejection heads, and has a liquid ejection unit that ejects the liquid, a first liquid receiving unit that receives the liquid ejected by the plurality of liquid ejection heads performing idle ejections in parallel that do not contribute to the image, a second liquid receiving unit that receives the liquid ejected by the plurality of liquid ejection heads performing the idle ejections non-parallel, and a control unit that controls the liquid ejection unit so that the plurality of liquid ejection heads perform the idle ejections non-parallel toward the second liquid receiving unit when a total idle ejection discharge amount, which is the total amount of the liquid discharged by the idle ejections, is equal to or greater than a predetermined change threshold, and the control unit controls the liquid ejection unit so that the plurality of liquid ejection heads sequentially perform the idle ejections toward the second liquid receiving unit when the total idle ejection discharge amount is equal to or greater than a predetermined change threshold .

The present invention can suppress mist.

1 is a diagram illustrating an example of the configuration of an image forming apparatus according to an embodiment. 1 is a block diagram of an example of a hardware configuration of an image forming apparatus according to an embodiment; 4 is a block diagram of an example of a functional configuration of a main control unit according to the first embodiment. FIG. 4 is a flowchart illustrating an example of an operation of the image forming apparatus according to the first embodiment. 13 is a flowchart showing a blank discharge cap discharge sequence. 10 is a flowchart of another example of the operation of the image forming apparatus according to the first embodiment. 5A and 5B are diagrams showing examples of evaporation amount conversion tables, in which FIG. 5A shows an evaporation amount conversion table for one ink type, and FIG. 5B shows an evaporation amount conversion table for another ink type. FIG. 11 is a block diagram of an example of a functional configuration of a main control unit according to a second embodiment. 10 is a flowchart of an example of the operation of an image forming apparatus according to a second embodiment. FIG. 13 is a block diagram of an example of a functional configuration of a main control unit according to a third embodiment. FIG. 11 is a diagram illustrating an example of busy time period information. 13 is a flowchart of an example of the operation of the image forming apparatus according to the third embodiment.

Below, a description will be given of a mode for carrying out the invention with reference to the drawings. In each drawing, the same components are given the same reference numerals, and duplicated explanations may be omitted. Furthermore, the embodiments shown below are illustrative of an image forming apparatus for embodying the technical concept of the present invention, and the present invention is not limited to the embodiments shown below. Unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended as examples, and are not intended to limit the scope of the present invention thereto. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated to clarify the explanation.

The image forming apparatus according to the embodiment is an apparatus that ejects liquid to form an image on a recording medium such as plain paper, glossy paper, or film. The image forming apparatus has a liquid ejection section that includes multiple liquid ejection heads and ejects liquid. It also has a first liquid receiving section that receives liquid ejected by the multiple liquid ejection heads performing idle ejections in parallel that do not contribute to the image, and a second liquid receiving section that receives liquid ejected by the multiple liquid ejection heads performing idle ejections in non-parallel.

In the embodiment, when the total amount of idling discharged is equal to or greater than a predetermined change threshold, the liquid discharge unit is controlled so that the multiple liquid discharge heads perform idling in a non-parallel manner toward the second liquid receiving unit. As a result, when the first liquid receiving unit becomes full, for example, the location for idling is switched to the second liquid receiving unit, thereby preventing the image forming device from ceasing operation. In addition, by having the multiple liquid discharge heads perform idling in a non-parallel manner toward the second liquid receiving unit, the amount of liquid discharged in a single idling operation is reduced compared to when all of the multiple liquid discharge heads perform idling in parallel, and mist that occurs due to liquid rebound, etc. is suppressed.

Here, blank ejection refers to ejection that does not contribute to image formation. The term blank ejection can be replaced with terms such as preliminary ejection, flushing, purging, or dummy jet. By having the liquid ejection head perform blank ejection, it is possible to eject thickened liquid from inside the liquid ejection head and prevent the nozzles from drying out, thereby maintaining the head in a normal state without non-ejecting nozzles. The total blank ejection discharge volume refers to the total amount (accumulated amount) of liquid ejected by blank ejection.

Mist is a very small, floating mist of liquid. When mist is generated, the inside of the image forming device becomes dirty with the mist, and the recording medium inside the image forming device becomes dirty with the mist. Performing idle ejection in parallel means performing idle ejection from multiple liquid ejection heads at the same time, while performing idle ejection in a non-parallel manner means not performing idle ejection from multiple liquid ejection heads at the same time, in other words, performing idle ejection at different times for each liquid ejection head.

The following describes an embodiment using as an example an image forming apparatus using a so-called serial inkjet method in which a liquid ejection unit including a liquid ejection head moves.

In the terms of the embodiment, image formation, recording, printing, imprinting, and printing are all synonymous. The liquid is not particularly limited as long as it has a viscosity and surface tension that allows it to be ejected from a liquid ejection head, but it is preferable that the viscosity is 30 mPa·s or less at room temperature and normal pressure, or by heating or cooling. More specifically, the liquid may be a solution, suspension, emulsion, etc. that contains a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural dye, etc., and these can be used for applications such as inkjet ink, surface treatment liquid, a liquid for forming a component of an electronic element or a light-emitting element, an electronic circuit resist pattern, and a material liquid for three-dimensional modeling.

A liquid ejection head is a functional component that ejects and sprays liquid from a nozzle. The energy source for ejecting liquid includes those that use piezoelectric actuators (laminated piezoelectric elements and thin-film piezoelectric elements), thermal actuators that use electrothermal conversion elements such as heating resistors, and electrostatic actuators that consist of a vibration plate and an opposing electrode.

<Configuration Example of Image Forming Apparatus According to the Embodiment>
First, the configuration of an image forming apparatus according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram illustrating an example of the configuration of an image forming apparatus 1.

As shown in FIG. 1, the image forming device 1 has a carriage 2, a liquid ejection unit 3, an ink cartridge 4, a fixed waste liquid tank 5, a maintenance unit 7, and a replacement waste liquid tank 8.

The carriage 2 can move back and forth in the main scanning direction corresponding to the X-axis direction. Here, the main scanning direction refers to a direction perpendicular to the transport direction (sub-scanning direction) of the paper 9 corresponding to the Y-axis direction. A liquid ejection unit 3 is fixed to the carriage 2, and the liquid ejection unit 3 can move back and forth by the reciprocating movement of the carriage 2.

The liquid ejection unit 3 includes multiple liquid ejection heads 3a, 3b, 3c, and 3d, and is an example of a liquid ejection section that ejects ink from nozzles in each of the multiple liquid ejection heads 3a, 3b, 3c, and 3d. The liquid ejection head 3a ejects black (K) ink, and the liquid ejection head 3b ejects cyan (C) ink. The liquid ejection head 3c ejects magenta (M) ink, and the liquid ejection head 3d ejects yellow (Y) ink.

The ink cartridges 4 include ink cartridges 4a, 4b, 4c, and 4d. Ink cartridge 4a supplies K ink to liquid ejection head 3a, and ink cartridge 4b supplies C ink to liquid ejection head 3b. Ink cartridge 4c supplies M ink to liquid ejection head 3c, and ink cartridge 4d supplies Y ink to liquid ejection head 3d.

The image forming device 1 can form an image on the paper 9 by moving the liquid ejection unit 3 back and forth in the main scanning direction while transporting the paper 9 in the sub-scanning direction and ejecting ink of each color.

The fixed waste liquid tank 5 is a place where ink is discharged from the liquid ejection unit 3 due to idle ejection. The fixed waste liquid tank 5 is an example of a first liquid receiving section that receives ink ejected by the liquid ejection heads 3a, 3b, 3c, and 3d performing idle ejections in parallel that do not contribute to the image. The fixed waste liquid tank 5 also includes a storage section that stores ink ejected from the liquid ejection unit 3 during idle ejection.

The image forming device 1 has a fixed waste liquid tank 5 on the negative side of the X-axis inside the image forming device 1. The fixed waste liquid tank 5 has slits corresponding to the number of liquid ejection heads. The liquid ejection heads 3a, 3b, 3c, and 3d can discharge ink by performing idle ejection in parallel toward the fixed waste liquid tank 5.

The maintenance unit 7 includes caps 6a, 6b, 6c, and 6d (referred to as "cap 6" when no distinction is made), and operates to maintain normal ejection by the liquid ejection unit 3. The image forming device 1 is provided with the maintenance unit 7 on the positive X-axis side within the image forming device 1. When image formation is completed, the image forming device 1 moves the liquid ejection unit 3 to a retracted position where the maintenance unit 7 is located, and caps the liquid ejection heads 3a, 3b, 3c, and 3d with cap 6.

Of the caps 6, cap 6a is a suction cap equipped with a suction mechanism for sucking ink from the head when performing maintenance operations on the liquid ejection unit 3. The ink sucked by cap 6a passes through a connected tube and reaches replacement waste tank 8 installed at the bottom of the ink cartridge. Replacement waste tank 8 is a replaceable tank that stores the ink that reaches it.

Cap 6a can also be used as a discharge location for ink that has been blank-discharged. When blank-discharge is performed on cap 6a, image forming device 1 moves each of liquid discharge heads 3a, 3b, 3c, and 3d in sequence to the position of cap 6a, and blank discharge is performed by each of them. Cap 6a corresponds to an example of a second liquid receiving section that receives the liquid discharged by the liquid discharge heads performing the blank discharge non-parallel. Each of caps 6 is also an example of a moisturizing section that moisturizes the nozzles of each of liquid discharge heads 3a, 3b, 3c, and 3d.

In this embodiment, a configuration in which one suction cap is provided is exemplified, but two or more suction caps may be provided. However, even when two or more suction caps are provided, when performing blank discharge to cap 6a, image forming device 1 performs blank discharge non-parallel from each of liquid discharge heads 3a, 3b, 3c, and 3d.

If all liquid ejection heads 3a, 3b, 3c, and 3d are idle-ejected in parallel, the amount of mist scattered may increase, which may soil the maintenance unit 7. Since the maintenance unit 7 has a head cleaning member such as a wiper (not shown), it is preferable to minimize soiling caused by mist. By providing a suction mechanism only for cap 6a and idle-ejecting each of the liquid ejection heads 3a, 3b, 3c, and 3d one by one, it is possible to prevent soiling caused by mist.

Also, by making only cap 6a a suction cap, there is only one suction mechanism, which reduces costs. Furthermore, by using only one suction cap, the absorbent material (not shown) inside the suction cap can be sufficiently moistened, preventing ink from drying out inside the nozzles when the head is capped.

If all caps 6 were used as suction caps and blank discharge were performed, the total blank discharge amount, which is the amount of ink discharged by blank discharge for each cap 6, would be smaller. Although the ink discharged into the cap 6 is sucked up, it remains in a state of soaking into the surface of the fibrous absorbent material inside the cap 6. When the ink adheres to the absorbent material dries, it has a moisture absorbing effect, and when the liquid discharge heads 3a, 3b, 3c, and 3d are capped, this may promote the drying of the ink on the nozzle surface.

If the total discharge amount of idling is small, the ink in the absorber dries out easily, which may cause problems with drying out the ink on the nozzle surface. When there is only one suction cap, a relatively large amount of ink is discharged to the suction cap, so the absorber remains sufficiently moist and is less likely to dry even after the cap is sucked in, making it possible to effectively prevent the ink on the nozzle surface from drying out when capping.

In this embodiment, caps 6b to 6d are dedicated moisturizing caps that do not have an absorbent and do not eject ink, so there is no concern about drying out during capping.

<Example of Hardware Configuration of Image Forming Apparatus 1>
Next, a hardware configuration of the image forming apparatus 1 will be described with reference to Fig. 2. Fig. 2 is a block diagram illustrating an example of a hardware configuration of the image forming apparatus 1.

As shown in FIG. 2, the image forming device 1 includes a control unit 500. The image forming device 1 includes a CPU (Central Processing Unit) 501 that controls the entire device, and a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, a non-volatile memory (NVRAM: Non-Volatile RAM) 504, and an ASIC (Application Specific Integrated Circuit) 505 that are connected to the CPU 501. The CPU 501, ROM 502, RAM 503, and NVRAM 504 function as a main control unit 500A that controls the main body.

The ROM 502 stores the programs executed by the CPU 501 and other fixed data. The RAM 503 temporarily stores image data and the like. The NVRAM 504 retains data even while the power to the image forming device 1 is cut off. The ASIC 505 serves as an image processing unit that performs various signal processing to convert document image data into print image data and image processing such as sorting, and an image correction unit that corrects image data based on color information of the recording medium, and also processes input/output signals for controlling the entire device.

The control unit 500 also includes a host I/F 506, a print control unit 508, a motor drive unit 510, a supply system drive unit 512, and an ejection detection unit 515. The control unit 500 also connects an operation panel 514 to a temperature sensor 572 and other sensors 570 through an I/O 513.

The host I/F 506 is an interface that transmits and receives data and signals to and from the host side. Specifically, the host I/F 506 receives print data generated by a printer driver of a host such as an information processing device, image reading device, or imaging device via a cable, network, or the like. In other words, the print data may be generated and output to the control unit 500 by a printer driver on the host side. The CPU 501 reads and analyzes the print data in the receive buffer included in the host I/F 506. Then, the ASIC 505 performs image processing, data sorting, and the like, and the image data is transferred to the print control unit 508 and head driver 509.

The print control unit 508 generates a drive waveform for driving the liquid ejection unit 3, and outputs image data and various associated data to the head driver 509 to selectively drive the pressure generating means that generates pressure for the liquid ejection head 3 to eject liquid from the nozzles.

The print control unit 508 may be configured as a computer having a CPU, ROM, RAM, etc. The print control unit 508 performs the desired functions by the CPU executing a program stored in the ROM, etc.

The program executed by the CPU of the print control unit 508 may be provided by being recorded in an installable or executable format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk).

Furthermore, the program executed by the CPU of the print control unit 508 may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also, the program executed by the CPU of the print control unit 508 may be provided or distributed via a network such as the Internet.

The motor drive unit 510 drives the main scanning motor 50, the sub-scanning motor 15, and the maintenance and recovery motor 556. The main scanning motor 50 moves the carriage 2 equipped with the liquid ejection unit 3 in the main scanning direction by driving it. The sub-scanning motor 15 operates the transport belt 12 that transports the paper onto which the liquid is to be ejected by the liquid ejection unit 3 by driving it. The maintenance and recovery motor 556 sucks up ink discharged onto the cap 6a by maintenance or idling by driving it, and sends the ink to the replacement waste liquid tank 8. The supply system drive unit 512 drives the liquid delivery pump 540 to supply ink from the ink cartridge 4 (see FIG. 1) to the liquid ejection unit 3.

The I/O 513 acquires information from a temperature sensor 572 and other sensors 570, and extracts information required to control each part of the image forming apparatus 1. For example, the sensors 570 may include a liquid level sensor that detects the capacity of the replacement waste liquid tank 8. The operation panel 514 allows the user to input and display various information.

[First embodiment]
<Example of functional configuration of main control unit 500A>
Next, the functional configuration of the main control unit 500A will be described with reference to Fig. 3. Fig. 3 is a block diagram illustrating an example of the functional configuration of the main control unit 500A. As shown in Fig. 3, the main control unit 500A has a blank discharge counting unit 51, a blank discharge total discharge amount acquiring unit 52, an elapsed time measuring unit 53, an evaporation amount acquiring unit 54, a determining unit 55, a storing unit 56, and a receiving unit 57.

Of these, the functions of the blank discharge counting unit 51, blank discharge total discharge amount acquisition unit 52, elapsed time measurement unit 53, evaporation amount acquisition unit 54, determination unit 55, and reception unit 57 are realized by the CPU 501 in FIG. 2 executing a predetermined program, etc. The function of the storage unit 56 is realized by the NVRAM 504, etc.

The idling counting unit 51 counts each time the image forming device 1 performs an idling operation and obtains information on the number of idling operations.

The total idling discharge amount acquisition unit 52 acquires the total idling discharge amount. The total idling discharge amount acquisition unit 52 acquires information on the total idling discharge amount as a calculated idling discharge amount, i.e., a soft count, obtained by multiplying the droplet amount obtained from the idling discharge droplet amount table stored in the storage unit 56 by the number of droplets discharged, which is preset according to various conditions such as temperature and drive waveform type, and stores the information in the storage unit 56.

The elapsed time measurement unit 53 measures the elapsed time from when the total amount of empty discharge becomes equal to or greater than the change threshold. Here, the change threshold refers to a threshold for determining whether the fixed waste liquid tank 5 can be used as a discharge location for empty discharge. When the total amount of empty discharge exceeds the change threshold, the image forming device 1 determines that the fixed waste liquid tank 5 cannot be used as a discharge location for empty discharge, and the elapsed time measurement unit 53 starts measuring the elapsed time.

The evaporation amount acquisition unit 54 acquires evaporation amount information of the ink stored in the fixed waste liquid tank 5. For example, the evaporation amount acquisition unit 54 acquires evaporation amount information based on the elapsed time received from the elapsed time measurement unit 53, the type of ink, and the temperature and humidity around the fixed waste liquid tank 5 detected by the temperature sensor 572 and the sensor group 570. The storage unit 56 stores an evaporation amount conversion table indicating the correspondence between the elapsed time, the type of ink, and the temperature and humidity around the fixed waste liquid tank 5, and the evaporation amount acquisition unit 54 can acquire evaporation amount information by referring to the evaporation amount conversion table based on the elapsed time received from the elapsed time measurement unit 53.

The determination unit 55 determines whether the ink is discharged from the idling to either the fixed waste liquid tank 5 or the cap 6a based on the total amount of ink discharged from the idling and the amount of ink evaporated from the fixed waste liquid tank 5. Depending on the result of the determination, the print control unit 508 and the motor drive unit 510 work together to perform idling toward either the fixed waste liquid tank 5 or the cap 6a.

The reception unit 57 can receive user operations such as setting operations via the operation panel 514.

<Operation Example of Image Forming Apparatus 1>
Next, the operation of the image forming apparatus 1 will be described with reference to FIGS.

The location where ink is discharged during idling can be selected according to the timing of idling, such as before or during printing. For example, in order to avoid reducing the printing speed during printing, all liquid discharge heads 3a, 3b, 3c, and 3d can perform idling in parallel to the fixed waste liquid tank 5, and when there is little impact on the actual printing time, such as before or after printing, the liquid discharge heads 3a, 3b, 3c, and 3d can perform idling sequentially to the cap 6a.

The image forming device 1 sets a change threshold for the fixed waste liquid tank 5 and a return threshold for the cap 6a. The image forming device 1 determines that the fixed waste liquid tank 5 is unusable when the soft count of the total empty discharge amount exceeds the change threshold, and determines that the cap 6a is unusable when the total empty discharge amount exceeds the return threshold. Since the cap 6a is connected to the replacement waste liquid tank 8, if it is determined that the replacement waste liquid tank 8 is unusable, the user is notified via the operation panel 514 that the replacement waste liquid tank 8 is full and a replacement is requested.

When the total amount of ink discharged during idling is equal to or greater than the change threshold and it is determined that the fixed waste tank 5 cannot be used as an ink discharge location during idling, the image forming device 1 changes the discharge location to the cap 6a. By changing the discharge location, even if the unreplaceable fixed waste tank 5 becomes unusable, the machine can be used continuously without calling a service technician.

After it is determined that the fixed waste tank 5 is full and unusable, the amount of ink evaporation obtained according to the elapsed time is subtracted from the total amount of ink discharged from the fixed waste tank 5, and the newly obtained soft count value is stored in the NVRAM 504.

When the soft count value falls below the return threshold, which is smaller than the change threshold at which the fixed waste liquid tank 5 is determined to be unusable, the image forming device 1 determines that the total amount of empty discharge stored in the fixed waste liquid tank 5 has decreased due to evaporation and that discharge is possible again. Then, the discharge location is changed from the cap 6a back to the fixed waste liquid tank 5. The change threshold, return threshold, and discharge location according to the threshold can be changed and set by the user, and are configured to be freely customized according to the usage situation.

In the case of an image forming device 1 that uses multiple types of ink, the evaporation rate differs for each ink formulation used, so the image forming device 1 sets an ink evaporation count for each type of ink used. In addition, the amount of ink evaporation varies depending on the temperature and humidity of the surrounding environment, so the image forming device 1 sets an evaporation count for each temperature and humidity of the surrounding environment.

Since the amount of ink evaporation is affected in various ways depending on the conditions under which the device is used, the evaporation count that is pre-set on the device can be changed by a modification operation and stored in NVRAM 504, allowing the user to correct for variation. It is configured so that it can be customized according to the conditions of use to operate with high precision.

Here, FIG. 4 is a flow chart showing an example of the operation of the image forming device 1. Note that FIG. 4 shows the operation triggered by the start of blank ejection. The explanation will also refer to FIG. 1 to FIG. 3 as appropriate.

First, in step S41, the total empty discharge amount acquisition unit 52 acquires information on the total empty discharge amount, and the determination unit 55 determines whether the total empty discharge amount is equal to or greater than the change threshold value.

If it is determined in step S41 that the change threshold is not exceeded (step S41, No), in step S42, the image forming device 1 moves the carriage 2 to the position of the fixed waste liquid tank 5.

Next, in step S43, all liquid ejection heads 3a, 3b, 3c, and 3d perform blank ejection in parallel toward the fixed waste liquid tank 5.

On the other hand, if it is determined in step S44 that the change threshold is exceeded (step S41, Yes), the liquid ejection heads 3a, 3b, 3c, and 3d sequentially perform blank ejection toward the cap 6a.

In this way, the image forming device 1 can perform blank ejection.

Next, FIG. 5 is a flow chart showing the sequence of sequential blank ejection. FIG. 5 shows the operation of the image forming device 1 triggered by the start of sequential blank ejection. Note that in FIG. 5, liquid ejection heads 3a, 3b, 3c, and 3d are abbreviated and written as heads 3a, 3b, 3c, and 3d.

First, in step S51, the image forming device 1 moves the head 3d to the position of the cap 6a, and in step S52, performs idle ejection of the head 3d.

Next, in step S53, the image forming device 1 moves the head 3c to the position of the cap 6a, and in step S54, performs blank ejection of the head 3c.

Next, in step S55, the image forming device 1 moves head 3b to the position of cap 6a, and in step S56, performs blank ejection of head 3b.

Next, in step S55, the image forming device 1 moves head 3b to the position of cap 6a, and in step S56, performs blank ejection of head 3b.

Next, in step S57, the image forming device 1 moves the head 3a to the position of the cap 6a, and in step S57, performs idle ejection of the head 3a.

In this way, the image forming device 1 can sequentially perform idle ejection for each of the liquid ejection heads 3a, 3b, 3c, and 3d.

When the carriage 2 is positioned at the cap 6 position, the blank ejection to the cap 6a is performed sequentially starting from the head 3d furthest from the transport side. When printing, it is preferable that the carriage 2 reaches a specified speed on the transport belt 12, and therefore it is preferable to accelerate the carriage 2 from the right end of the image forming device 1. By performing blank ejection from the head 3a last during blank ejection at the cap 6 position, the carriage 2 is positioned at the right end of the image forming device 1 when the blank ejection ends, and a sufficient acceleration distance can be secured when continuing to print.

Next, FIG. 6 is a flowchart showing another example of the operation of the image forming device 1. In the example shown in FIG. 4, the location where ink is discharged during idling is determined based only on the total amount of ink discharged during idling, but in the example shown in FIG. 6, the location where ink is discharged during idling is determined based on the total amount of ink discharged during idling and the amount of ink evaporated in the fixed waste liquid tank 5.

Note that FIG. 6 shows the operation triggered by the start of blank discharge. The operation of step S61 in FIG. 6 is the same as the operation of step S41 in FIG. 4, and the operations of steps S64 to S66 in FIG. 6 are the same as the operations of steps S42 to S44 in FIG. 4. Therefore, duplicated explanations will be omitted here. The explanation will be given with reference to FIG. 1 to FIG. 3 as appropriate.

If the total blank discharge discharge amount is stabilized to be equal to or greater than the change threshold in step S61 (step S61, Yes), in step S62, the elapsed time measurement unit 53 measures the elapsed time since the total blank discharge discharge amount became equal to or greater than the change threshold, and the evaporation amount acquisition unit 54 acquires evaporation amount information of the ink stored in the fixed waste liquid tank 5 based on the measured time.

Next, in step S63, the determination unit 55 determines whether the difference between the total blank discharge amount and the ink evaporation amount is equal to or greater than the return threshold. If it is determined in step S63 that the difference is not equal to or greater than the return threshold (step S63, No), the image forming device 1 determines that the amount of evaporation is too small to reuse the fixed waste liquid tank 5, and executes steps S64 to S65. On the other hand, if it is determined in step S63 that the difference is equal to or greater than the return threshold (step S63, Yes), the image forming device 1 determines that a reusable volume has been secured in the fixed waste liquid tank 5 due to the evaporation of ink, and executes step S66.

In this way, the image forming device 1 can perform blank ejection.

Here, FIG. 7 shows an example of an evaporation amount conversion table stored in the storage unit 56. (a) shows an evaporation amount conversion table for one ink type, and (b) shows an evaporation amount conversion table for another ink type.

Figure 7 shows the relationship between elapsed time and the amount of ink evaporation. It also shows the amount of ink evaporation in high temperature (H) and low temperature (L) states, and in high humidity (H) and low humidity (L) states. When the temperature and humidity are both high, it is displayed as "HH", when the temperature and humidity are both high, it is displayed as "HL", when the temperature and humidity are both low, it is displayed as "LH", and when the temperature and humidity are both low, it is displayed as "LL".

The image forming device 1 can predefine such an evaporation amount conversion table for each type of ink and store it in the storage unit 56.

<Functions and Effects of Image Forming Apparatus 1>
As described above, in this embodiment, when the total amount of blank discharge is equal to or greater than a predetermined change threshold, the liquid discharge unit is controlled so that the liquid discharge heads perform blank discharge in a non-parallel manner toward the second liquid receiving unit (cap 6a). For example, the liquid discharge heads are controlled so that they sequentially perform blank discharge toward the second liquid receiving unit.

As a result, for example, if the first liquid receiving section (fixed waste liquid tank 5) becomes full, the location for performing the empty discharge can be switched to the second liquid receiving section, thereby preventing the image forming device from stopping operation.

In addition, by having the multiple liquid ejection heads perform idle ejection non-parallelly toward the second liquid receiving portion, the amount of liquid ejected at one time can be reduced compared to when all of the multiple liquid ejection heads perform idle ejection in parallel, and mist generated due to liquid rebound, etc. can be suppressed. This prevents the interior of the image forming device and various sensors, encoders, etc. installed within the image forming device from being soiled, and also prevents mist from scattering outside the image forming device and soiling recording media, etc. outside the device.

In this embodiment, the second liquid receiving section includes a moisturizing section (cap 6) that moisturizes the nozzles of the liquid ejection head, and some of the multiple moisturizing caps included in the moisturizing section are suction caps (cap 6a) that have a suction mechanism that sucks up the liquid in the moisturizing caps. Then, when the total amount of empty ejection discharge is equal to or greater than a predetermined change threshold, the image forming device controls the multiple liquid ejection heads to sequentially perform empty ejection toward the suction caps.

In this way, by making only one of the moisturizing caps a suction cap, the suction mechanism is reduced to one, reducing costs. Furthermore, by using only one suction cap, the absorbent inside the suction cap can be sufficiently moistened, preventing the liquid inside the nozzle from drying out when capping the head.

In addition, in this embodiment, the number of times the liquid ejection section (liquid ejection unit 3) performs blank ejection is counted to obtain information on the total blank ejection discharge amount, and based on the obtained information on the total blank ejection discharge amount, the liquid ejection section is controlled so that the multiple liquid ejection heads perform blank ejection in non-parallel toward the second liquid receiving section. In this way, a means for measuring the amount of liquid stored in the first liquid receiving section is not required, and an image forming apparatus can be configured simply and at low cost.

In addition, in this embodiment, the liquid ejection unit is controlled to perform an empty ejection toward either the first or second liquid receiving unit based on the total empty ejection amount and the evaporation amount of liquid. This allows the volume to be reused when the evaporation of liquid secures a volume for storing liquid in the storage unit of the first liquid receiving unit.

In addition, in this embodiment, evaporation information is acquired based on the time elapsed since the total amount of idling discharge became equal to or greater than the change threshold, the type of liquid, and the temperature and humidity around the first liquid receiving section. Then, based on the total amount of idling discharge and the evaporation amount information acquired by the evaporation amount acquisition section, the liquid ejection section is controlled to perform idling discharge toward either the first or second liquid receiving section. This eliminates the need for a means for measuring the amount of evaporation of liquid, making it possible to configure an image forming apparatus simply and at low cost.

In addition, this embodiment has a reception unit that receives input operations for the change threshold value. This allows the user to change the change threshold value and customize it as desired depending on the usage status of the image forming device.

[Second embodiment]
Next, an image forming apparatus 1a according to a second embodiment will be described. The same components as those described in the first embodiment are given the same part numbers, and duplicated descriptions will be omitted as appropriate. This also applies to the following embodiments.

In this embodiment, the image forming device 1a has at least two image forming modes, a high-speed mode and a high-resolution mode, and when the difference between the total blank discharge amount and the evaporation amount of ink is equal to or less than a return threshold that is smaller than the change threshold and an image is formed in high-speed mode, the liquid discharge unit is controlled to perform blank discharge toward the first liquid receiving unit. This makes it possible to handle high-speed image formation by utilizing the first liquid receiving unit that has become reusable due to the evaporation of ink, and by having all liquid discharge heads perform blank discharge in parallel.

In addition, when the difference between the total amount of blank discharge and the amount of evaporation is equal to or less than the return threshold, which is smaller than the change threshold, and an image is formed in high resolution mode, the liquid discharge unit is controlled to perform blank discharge toward the second liquid receiving unit. This allows multiple liquid discharge heads to perform blank discharge non-parallelly, thereby suppressing the generation of mist and enabling high resolution image formation.

<Example of Functional Configuration of Image Forming Apparatus 1a>
The image forming apparatus 1a has a similar configuration to the image forming apparatus 1 shown in the first embodiment, but differs mainly in the functional configuration of a main control unit 500A included in the image forming apparatus 1a.

Figure 8 is a block diagram illustrating an example of the functional configuration of such a main control unit 500Aa. As shown in Figure 8, the main control unit 500Aa has an operation mode acquisition unit 58 and a determination unit 55a. The image forming device 1a can operate in at least two image formation modes: a high-speed mode and a high-resolution mode.

The operation mode acquisition unit 58 can acquire information indicating the operation mode of the image forming device 1a and provide it to the determination unit 55a.

The determination unit 55a determines to perform blank discharge toward the first liquid receiving section when the difference between the total blank discharge amount and the amount of ink evaporation is equal to or less than the return threshold and an image is formed in high-speed mode. Also, when the difference between the total blank discharge amount and the amount of ink evaporation is equal to or less than the return threshold and an image is formed in high-resolution mode, the determination unit 55a determines to perform blank discharge toward the second liquid receiving section.

<Example of Operation of Image Forming Apparatus 1a>
In the image forming device 1a, the change threshold value for determining that the fixed waste liquid tank 5 is unusable may be set to a value equal to the amount of ink that fills the fixed waste liquid tank 5, or may be set to a value a predetermined amount less than the amount of ink that fills the tank 5. When the change threshold value is a value less than full, a surplus capacity is left to allow the fixed waste liquid tank 5 to be discharged until it is full, making it possible to select the fixed waste liquid tank 5 as a discharge location depending on the conditions.

For example, one of the conditions for selecting the fixed waste liquid tank 5 is the resolution setting of the print image. The print image is formed by repeatedly scanning the carriage 2 in the main scanning direction. At low resolution, the density of the image dots formed is low, so the number of scans is small, and at high resolution, the number of scans is large to arrange the image dots at high density. The resolution setting can be set in the print mode specified by the user, and the time required to complete printing differs for each print mode because the number of scans differs for each print mode.

When the high-speed print mode is set, the print speed is given more importance than the print image quality, and when the high-resolution print mode is set, the print image quality is given more importance than the print speed. Therefore, the discharge position of the blank ejection can be selected appropriately depending on the print mode.

When the total amount of empty discharge from the fixed waste liquid tank 5 exceeds the change threshold and the discharge location for empty discharge is switched to the cap 6a, empty discharge is sequentially and repeatedly performed from each liquid discharge head to the cap 6a, so discharge takes longer than when discharged to the fixed waste liquid tank 5.

Therefore, even if the cap 6a is in a state where blank discharge is being performed, if the high-speed printing mode is selected by the user, the discharge location for blank discharge can be switched from the cap 6a to the fixed waste liquid tank 5, allowing all liquid discharge heads 3a, 3b, 3c, and 3d to discharge in parallel, thereby reducing the time required for blank discharge.

Conversely, even if the fixed waste liquid tank 5 is in a state where empty discharge is being performed, if the high-resolution print mode is selected, the mode is originally low productivity and prioritizes image quality, so there is no degradation in image quality even if discharged into the cap 6a, and there is little impact on users who want high-quality printed images.

Here, FIG. 9 is a flow chart showing an example of the operation of the image forming apparatus 1a. Note that FIG. 9 shows the operation triggered by the start of dummy discharge. Also, the operations of steps S91 to S95 in FIG. 9 are the same as the operations of steps S61 to S65 in FIG. 6, and the operation of step S97 in FIG. 9 is the same as the operation of step S66 in FIG. 6, so duplicated explanations will be omitted here. The explanation will be given with reference to FIG. 1, FIG. 2 and FIG. 8 as appropriate.

In step S96, the operation mode acquisition unit 58 acquires information indicating the operation mode of the image forming device 1a, and the determination unit 55a determines whether the operation mode is the high resolution mode.

If it is determined in step S96 that the operation mode is not the high-resolution mode (step S96, No), the operation mode is the high-speed mode, so the image forming device 1a executes steps S94 to S95, and performs idle ejection of the liquid ejection heads 3a, 3b, 3c, and 3d in parallel to accommodate high-speed printing.

On the other hand, if it is determined in step S96 that the mode is high resolution mode (step S96, Yes), the image forming device 1a executes step S97, and performs idle ejection from the liquid ejection heads 3a, 3b, 3c, and 3d in sequence, thereby suppressing the generation of mist and printing in high resolution mode.

In this way, the image forming device 1a can perform blank ejection.

<Functions and Effects of Image Forming Apparatus 1a>
As described above, in this embodiment, the image forming apparatus 1a has at least two image forming modes, a high-speed mode and a high-resolution mode, and when the difference between the total blank discharge amount and the evaporation amount of ink is equal to or less than the return threshold which is smaller than the change threshold and an image is formed in the high-speed mode, the liquid discharge unit is controlled to perform blank discharge toward the first liquid receiving unit. This makes it possible to handle high-speed image formation by utilizing the first liquid receiving unit which has become reusable due to the evaporation of ink, and by having all the liquid discharge heads perform blank discharge in parallel.

In addition, when the difference between the total amount of blank discharge and the amount of evaporation is equal to or less than the return threshold, which is smaller than the change threshold, and an image is formed in high resolution mode, the liquid discharge unit is controlled to perform blank discharge toward the second liquid receiving unit. This allows multiple liquid discharge heads to perform blank discharge non-parallelly, thereby suppressing the generation of mist and forming a high resolution image.

All other effects and advantages are the same as those described in the first embodiment.

[Third embodiment]
Next, an image forming apparatus 1b according to a third embodiment will be described.

In this embodiment, when the difference between the total amount of empty discharge and the amount of ink evaporation is equal to or less than the recovery threshold, the liquid discharge unit is controlled to perform empty discharge toward the first liquid receiving unit during busy periods of the image forming device 1b, and to perform empty discharge toward the second liquid receiving unit during periods other than the busy periods. Here, busy periods refer to periods during which the image forming device is used frequently. In this way, it is possible to perform empty discharge at high speed during busy periods.

Figure 10 is a block diagram illustrating an example of the functional configuration of the main control unit 500Ab provided in the image forming device 1b. As shown in Figure 10, the main control unit 500Ab has a storage unit 56b, a busy time period acquisition unit 59, and a determination unit 55b.

The storage unit 56b stores information about busy periods for the image forming device 1b. For example, the storage unit 56b can store the printing date and time and the number of printed sheets as a printing log.

The busy time period acquisition unit 59 divides the printing time into hourly intervals based on the printing log stored in the storage unit 56b, and calculates the number of printed sheets per hour to acquire information about busy time periods when the image forming device 1b is used.

The print log referenced by the busy time period acquisition unit 59 may be, for example, the print log of the previous day, or the average print log for a certain period of time. The busy time period information acquired may be for a single time period per day, or multiple times per day. The settings for acquiring these busy time periods may be set in advance in the image forming device 1b, or may be configured to be configurable by the user or a service technician.

When the difference between the total amount of ink discharged during idling and the amount of ink evaporated is equal to or less than the recovery threshold, the determination unit 55b determines that the ink discharge location during idling is the fixed waste liquid tank 5 during busy hours of the image forming device 1b, and determines that the discharge location is the cap 6a during non-busy hours.

Here, FIG. 11 is a diagram explaining information showing busy time periods for image forming device 1b. FIG. 11 is an average of print logs for one week, and from this, when determining the three busiest times in one day, it is estimated that the number of printed sheets is high between 11:00, 14:00, and 15:00, and that a large number of print jobs need to be executed during those times.

Therefore, during these time periods, the determination unit 55b determines that the ink discharge location for the blank discharge is the fixed waste liquid tank 5, thereby shortening the time required for the blank discharge operation and reducing the user's waiting time. At other times, since the number of printed sheets is small, the determination unit 55b determines that the discharge location is the cap 6a for sequential blank discharge, which takes longer than when performed in parallel.

Next, FIG. 12 is a flow chart showing an example of the operation of image forming device 1b. Note that FIG. 12 shows the operation triggered by the start of dummy ejection. The operations of steps S121 to S125 in FIG. 12 are the same as the operations of steps S91 to S95 in FIG. 9, and the operation of step S128 in FIG. 12 is the same as the operation of step S97 in FIG. 9. Therefore, a duplicated explanation will be omitted here. The explanation will be given with reference to FIG. 1, FIG. 2 and FIG. 10 as appropriate.

In step S126, the busy time period acquisition unit 59 acquires information about the busy time period of the image forming device 1b by calculation based on the print log stored in the storage unit 56b.

Next, in step S127, the determination unit 55b determines whether the current time period is a busy time period.

If it is determined in step S127 that the current time period is during a busy period (Yes in step S127), the image forming device 1b executes steps S124 to S125, and performs idle ejection from the liquid ejection heads 3a, 3b, 3c, and 3d in parallel at high speed.

On the other hand, if it is determined in step S127 that the current time does not fall within the busy time period (step S127, No), the image forming device 1b executes step S128 and sequentially performs idle ejection from the liquid ejection heads 3a, 3b, 3c, and 3d while suppressing mist.

In this way, the image forming device 1b can perform blank ejection.

<Functions and Effects of Image Forming Apparatus 1a>
As described above, in this embodiment, when the difference between the total amount of ink discharged and the amount of ink evaporated is equal to or less than the return threshold, the liquid discharge unit is controlled to perform idle discharge toward the first liquid receiver (fixed waste liquid tank 5) during busy periods of the image forming apparatus, and to perform idle discharge toward the second liquid receiver (cap 6a) during periods other than busy periods. This allows idle discharge to be performed at high speed during busy periods, and allows appropriate idle discharge to be performed according to the usage status of the image forming apparatus.

Other effects are the same as those described in the first embodiment.

Although the embodiments have been described above, the present invention is not limited to the specifically disclosed embodiments above, and various modifications and variations are possible without departing from the scope of the claims.

For example, in the embodiment, a serial type liquid ejection type image forming apparatus is described, but the embodiment can also be applied to a line type liquid ejection type image forming apparatus in which the liquid ejection head does not move in the main scanning direction.

The embodiment includes a program. For example, the program is used in an image forming apparatus that ejects liquid to form an image on a recording medium, the image forming apparatus including a liquid ejection unit that includes a plurality of liquid ejection heads and ejects the liquid, a first liquid receiving unit that receives the liquid ejected by the plurality of liquid ejection heads performing idle ejections in parallel that do not contribute to the image, and a second liquid receiving unit that receives the liquid ejected by the plurality of liquid ejection heads performing the idle ejections in non-parallel, and causes a computer to execute a process to control the liquid ejection unit so that the idle ejection is performed toward either the first or second liquid receiving unit based on the total amount of idle ejection discharged by the liquid ejection unit when the idle ejection is performed. This allows the same effect as the image forming apparatus described above to be obtained.

In addition, all ordinal numbers, quantities, and other numbers used in the description of the embodiments are provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the exemplified numbers. In addition, the connections between the components are provided as examples to specifically explain the technology of the present invention, and the connections that realize the functions of the present invention are not limited to these.

The division of blocks in the functional block diagram is just one example, and multiple blocks may be realized as one block, one block may be divided into multiple blocks, and/or some functions may be transferred to other blocks. Furthermore, the functions of multiple blocks having similar functions may be processed in parallel or in a time-shared manner by a single piece of hardware or software.

Furthermore, each function of the embodiments described above can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and devices such as an ASIC (Application Specific Integrated Circuit), DSP (digital signal processor), FPGA (field programmable gate array), and conventional circuit modules designed to execute each function described above.

1 Image forming apparatus 2 Carriage 3 Liquid ejection unit (an example of a liquid ejection section)
3a, 3b, 3c, 3d Liquid ejection head 4 Ink cartridge 5 Fixed waste liquid tank (an example of a first receiving portion, an example of a storage portion)
6 Cap (an example of a moisturizing part, an example of a moisturizing cap)
6a Cap (an example of a moisturizing part, an example of a suction cap)
7 Maintenance unit 8 Replacement waste liquid tank 9 Paper 51 Blank discharge counting section 52 Blank discharge total discharge amount acquisition section 53 Elapsed time measurement section 54 Evaporation amount acquisition section 55 Determination section 56 Storage section 57 Reception section 58 Operation mode acquisition section 59 Busy time period acquisition section 500 Control section 500A Main control section

JP 2004-142207 A

Claims (12)

An image forming apparatus that ejects liquid to form an image on a recording medium,
a liquid ejection section including a plurality of liquid ejection heads and configured to eject the liquid;
a first liquid receiving portion that receives the liquid discharged by the plurality of liquid discharge heads performing dummy discharges in parallel that do not contribute to the image;
a second liquid receiving portion that receives the liquid discharged by the plurality of liquid discharge heads performing the idle discharge in a non-parallel manner;
a control unit that controls the liquid ejection unit so that the plurality of liquid ejection heads perform the blank ejection toward the second liquid receiving unit in a non-parallel manner when a blank ejection total ejection amount, which is a total amount of the liquid ejected by the blank ejection, is equal to or greater than a predetermined change threshold value;
The control unit controls the liquid ejection unit so that, when the total amount of blank ejection discharge is equal to or greater than a predetermined change threshold, the liquid ejection heads sequentially perform the blank ejection toward the second liquid receiving unit.
Image forming device. An image forming apparatus that ejects liquid to form an image on a recording medium,
a liquid ejection section including a plurality of liquid ejection heads and configured to eject the liquid;
a first liquid receiving portion that receives the liquid ejected by the plurality of liquid ejection heads performing dummy ejection in parallel that does not contribute to the image;
a second liquid receiving portion that receives the liquid discharged by the plurality of liquid discharge heads performing the idle discharge in a non-parallel manner;
a control unit that controls the liquid ejection unit so that the plurality of liquid ejection heads perform the blank ejection toward the second liquid receiving unit in a non-parallel manner when a blank ejection total ejection amount, which is a total amount of the liquid ejected by the blank ejection, is equal to or greater than a predetermined change threshold value;
a blank discharge total discharge amount acquisition unit that counts the number of times the liquid discharge unit has performed the blank discharge and acquires information on the blank discharge total discharge amount,
The control unit controls the liquid ejection unit so that the liquid ejection heads perform the blank ejection in a non-parallel manner toward the second liquid receiving unit, based on the information on the blank ejection total ejection amount acquired by the blank ejection total ejection amount acquisition unit.
Image forming device. An image forming apparatus that ejects liquid to form an image on a recording medium,
a liquid ejection section including a plurality of liquid ejection heads and configured to eject the liquid;
a first liquid receiving portion that receives the liquid ejected by the plurality of liquid ejection heads performing dummy ejection in parallel that does not contribute to the image;
a second liquid receiving portion that receives the liquid discharged by the plurality of liquid discharge heads performing the idle discharge in a non-parallel manner;
a control unit that controls the liquid ejection unit so that the plurality of liquid ejection heads perform the blank ejection toward the second liquid receiving unit in a non-parallel manner when a blank ejection total ejection amount, which is a total amount of the liquid ejected by the blank ejection, is equal to or greater than a predetermined change threshold value;
the second liquid receiving portion includes a moisturizing portion that moisturizes the nozzles of each of the plurality of liquid ejection heads;
the moisture retaining unit includes a moisture retaining cap for each of the plurality of liquid ejection heads,
some of the plurality of moisture retaining caps are suction caps having a suction mechanism that sucks the liquid inside the moisture retaining caps,
The control unit controls the liquid ejection unit so that, when the total amount of empty ejection discharge is equal to or greater than the change threshold value, the liquid ejection heads sequentially perform the empty ejection toward the suction cap.
Image forming device. An image forming apparatus that ejects liquid to form an image on a recording medium,
a liquid ejection section including a plurality of liquid ejection heads and configured to eject the liquid;
a first liquid receiving portion that receives the liquid ejected by the plurality of liquid ejection heads performing dummy ejection in parallel that does not contribute to the image;
a second liquid receiving portion that receives the liquid discharged by the plurality of liquid discharge heads performing the idle discharge in a non-parallel manner;
a control unit that controls the liquid ejection unit so that the plurality of liquid ejection heads perform the blank ejection toward the second liquid receiving unit in a non-parallel manner when a blank ejection total ejection amount, which is a total amount of the liquid ejected by the blank ejection, is equal to or greater than a predetermined change threshold value;
the first liquid receiving portion includes a storage portion configured to store the liquid used when the liquid ejection portion performs the blank ejection,
the second liquid receiving portion includes a moisturizing portion that moisturizes the nozzles of each of the plurality of liquid ejection heads;
The change threshold value is a value that is a predetermined amount less than the total empty discharge amount at which the storage portion becomes full,
The control unit controls the liquid ejection unit to perform the empty ejection toward either the first or the second liquid receiving unit based on the total empty ejection amount and the evaporation amount of the liquid stored in the storage unit after the total empty ejection amount becomes equal to or greater than the change threshold, and when a difference value between the total empty ejection amount and the evaporation amount is equal to or less than a return threshold which is smaller than the change threshold, controls the liquid ejection unit to perform the empty ejection toward either the first or the second liquid receiving unit based on information regarding a busy time period for image formation. the first liquid receiving portion includes a storage portion configured to store the liquid used when the liquid ejection portion performs the blank ejection,
the second liquid receiving portion includes a moisturizing portion that moisturizes the nozzles of each of the plurality of liquid ejection heads;
The change threshold value is a value that is a predetermined amount less than the total empty discharge amount at which the storage portion becomes full,
The control unit controls the liquid ejection unit to perform the empty ejection toward either the first or the second liquid receiving unit based on the total empty ejection amount and the evaporation amount of the liquid stored in the storage unit after the total empty ejection amount becomes equal to or greater than the change threshold, and controls the liquid ejection unit to perform the empty ejection toward the first liquid receiving unit when a difference value between the total empty ejection amount and the evaporation amount becomes equal to or less than a return threshold that is smaller than the change threshold . The image forming apparatus according to any one of claims 1 to 4. the image forming apparatus has at least two image forming modes, a high-speed mode and a high-resolution mode;
the first liquid receiving portion includes a storage portion configured to store the liquid used when the liquid ejection portion performs the blank ejection,
the second liquid receiving portion includes a moisturizing portion that moisturizes the nozzles of each of the plurality of liquid ejection heads;
The change threshold value is a value that is a predetermined amount less than the total empty discharge amount at which the storage portion becomes full,
The control unit controls the liquid ejection unit to perform the idle ejection toward either the first or the second liquid receiving unit based on the total amount of idle ejection and the amount of evaporation of the liquid stored in the storage unit after the total amount of idle ejection becomes equal to or greater than the change threshold, and controls the liquid ejection unit to perform the idle ejection toward the first liquid receiving unit when a difference between the total amount of idle ejection and the amount of evaporation is equal to or less than a return threshold that is smaller than the change threshold and an image is formed in the high-speed mode . The image forming apparatus according to any one of claims 1 to 5. the image forming apparatus has at least two image forming modes, a high-speed mode and a high-resolution mode;
the first liquid receiving portion includes a storage portion configured to store the liquid used when the liquid ejection portion performs the blank ejection,
The change threshold value is a value that is a predetermined amount less than the total empty discharge amount at which the storage portion becomes full,
The control unit controls the liquid ejection unit to perform the blank ejection toward either the first or the second liquid receiving unit based on the total blank ejection amount and the evaporation amount of the liquid stored in the storage unit after the total blank ejection amount becomes equal to or greater than the change threshold, and controls the liquid ejection unit to perform the blank ejection toward the second liquid receiving unit when a difference between the total blank ejection amount and the evaporation amount is equal to or less than a return threshold that is smaller than the change threshold and an image is formed in the high resolution mode . The image forming device according to any one of claims 1 to 4. 7. The image forming apparatus according to claim 4 , wherein the change threshold value is a value equal to the total discharge amount of the blank discharge at which the reservoir becomes full. An image forming apparatus that ejects liquid to form an image on a recording medium,
a liquid ejection section including a plurality of liquid ejection heads and configured to eject the liquid;
a first liquid receiving portion that receives the liquid ejected by the plurality of liquid ejection heads performing dummy ejection in parallel that does not contribute to the image;
a second liquid receiving portion that receives the liquid discharged by the plurality of liquid discharge heads performing the idle discharge in a non-parallel manner;
a control unit that controls the liquid ejection unit so that the plurality of liquid ejection heads perform the blank ejection toward the second liquid receiving unit in a non-parallel manner when a blank ejection total ejection amount, which is a total amount of the liquid ejected by the blank ejection, is equal to or greater than a predetermined change threshold value;
the first liquid receiving portion includes a storage portion configured to store the liquid used when the liquid ejection portion performs the blank ejection,
The change threshold value is a value that is a predetermined amount less than the total empty discharge amount at which the storage portion becomes full,
an evaporation amount acquisition unit that acquires information on the evaporation amount of the liquid stored in the storage unit based on the elapsed time since the total amount of empty discharge became equal to or greater than the change threshold value, the type of the liquid, and the temperature and humidity around the first liquid receiving unit,
The control unit controls the liquid discharge unit to perform the blank discharge toward either the first or the second liquid receiving unit, based on the total blank discharge amount and information on the evaporation amount acquired by the evaporation amount acquisition unit.
Image forming device. The image forming apparatus according to claim 4, wherein the control unit controls the liquid ejection unit to perform the idle ejection toward the first liquid receiving unit during the busy period, and to perform the idle ejection toward the second liquid receiving unit during periods other than the busy period. The image forming apparatus according to claim 1 , further comprising a reception unit that receives an input operation of the change threshold value. An image forming apparatus that ejects liquid to form an image on a recording medium,
a liquid ejection section including a plurality of liquid ejection heads and configured to eject the liquid;
a first liquid receiving portion that receives the liquid ejected by the plurality of liquid ejection heads performing dummy ejection in parallel that does not contribute to the image;
a second liquid receiving section that receives the liquid ejected by the plurality of liquid ejection heads performing the idle ejection in a non-parallel manner,
the first liquid receiving portion includes a storage portion configured to store the liquid used when the liquid ejection portion performs the blank ejection,
the second liquid receiving portion includes a moisturizing portion that moisturizes the nozzles of each of the plurality of liquid ejection heads;
a control unit controls the liquid ejection unit so that the plurality of liquid ejection heads perform the blank ejection toward the second liquid receiving unit in a non-parallel manner when a blank ejection total ejection amount, which is a total amount of the liquid ejected by the blank ejection, is equal to or greater than a predetermined change threshold value;
The change threshold value is a value that is a predetermined amount less than the total empty discharge amount at which the storage portion becomes full,
The control unit controls the liquid discharge unit to perform the blank discharge toward either the first or the second liquid receiving unit based on the total blank discharge amount and an evaporation amount of the liquid stored in the storage unit after the total blank discharge amount becomes equal to or greater than the change threshold, and controls the liquid discharge unit to perform the blank discharge toward either the first or the second liquid receiving unit based on information regarding a busy time period for image formation when a difference value between the total blank discharge amount and the evaporation amount is equal to or less than a return threshold that is smaller than the change threshold.
A program that causes a computer to carry out processing.

Images