JP7135357B2 - Liquid ejector - Google Patents

Description

The present invention relates to a liquid ejection device.

2. Description of the Related Art Among inkjet printers, there is known a so-called serial type printer in which a liquid ejection head for ejecting liquid such as ink reciprocates. The printing widths of such printers are varied because they are intended for everything from postcards to wallpaper and rolls of cloth. It takes a long time to scan back and forth in meters, so in order to complete image formation with fewer scans, you should increase the number of heads to fill the image, or use a lower resolution without increasing the number of heads. There are methods such as using larger droplets to fill the image. On the other hand, in order to improve gradation and graininess, there are techniques such as using light-colored ink and optimizing image processing.

Patent Document 1 (Japanese Patent Application Laid-Open No. 2015-186919) discloses a technique for drying and fixing ink on media using three heaters, a preheater, a print heater, and a postheater, and a hot air fan. .

However, the prior art has the problem that it is difficult to achieve both high density and good graininess while maintaining high productivity. In the prior art, a plurality of heaters or the like are used to dry and fix the ink on the medium in order to use the ink containing a non-volatile silicone surfactant. When droplets of different sizes are mixed and discharged in order to reduce the number of scans while maintaining gradation, dot coalescence occurs in which one of the droplets is absorbed by an adjacent droplet. I have something to do. Since the conventional technology uses an ink containing a silicone-based surfactant, coalescence of dots is likely to occur. As a result, in the conventional technology, the dot diameter increases due to the coalescence of the dots, and the graininess may become unfavorable.

The present invention has been made in view of the above, and an object of the present invention is to achieve both high density and good graininess while maintaining high productivity.

In order to solve the above-described problems and achieve the object, a liquid ejecting apparatus according to the present invention ejects a liquid containing a component that increases the dot diameter as the heating temperature increases, based on input data. a liquid ejection head having a nozzle row in which a plurality of nozzles forming a liquid application surface are arranged in the conveying direction of the object; Among a plurality of heating mechanisms for heating the liquid application surface, a first heating mechanism arranged upstream with respect to the conveying direction of the object, and a back surface of the liquid application surface below the liquid ejection head. a second heating mechanism arranged on the downstream side with respect to the conveying direction of the object among a plurality of heating mechanisms for heating the liquid application surface, and a dot diameter temperature of the liquid application surface; a temperature control unit for controlling setting of heating temperatures of the first heating mechanism and the second heating mechanism based on the dependency, wherein the temperature control unit controls the liquid application surface based on the input data; The setting of the heating temperature is controlled so that the dot diameter is less than the predetermined diameter at locations where the density of the liquid is less than a predetermined value, and the location where the density of the liquid coating surface is greater than or equal to the predetermined value from the input data. The setting of the heating temperature is controlled so that the diameter becomes equal to or larger than a predetermined diameter .

According to the present invention, it is possible to achieve both high density and good graininess while maintaining high productivity.

FIG. 1 is a block diagram showing a hardware configuration example of a liquid ejecting apparatus according to Embodiment 1. As shown in FIG. FIG. 2 is a diagram explaining each heater according to the first embodiment. FIG. 3 is a top view of the carriage according to the first embodiment. FIG. 4 is a block diagram showing a functional configuration example of the liquid ejection device according to the first embodiment. FIG. 5 is a diagram illustrating an example of the relationship between heater temperature and dot diameter according to the first embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a liquid ejecting apparatus according to the present invention will be described below with reference to the accompanying drawings. The present invention is not limited by the following embodiments.

(Embodiment 1)
A hardware configuration of the liquid ejecting apparatus 100 according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a hardware configuration example of a liquid ejecting apparatus 100 according to Embodiment 1. As shown in FIG.

As shown in FIG. 1, the liquid ejection device 100 includes a control section 101 . The liquid ejecting apparatus 100 also includes a CPU (Central Processing Unit) 102 that controls the entire apparatus. The liquid ejecting apparatus 100 includes a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, a non-volatile memory (NVRAM: Non-Volatile RAM) 105, and an ASIC (Application Specific Integrated Circuit) for the CPU 102. 106.

The ROM 103 stores programs executed by the CPU 102 and other fixed data. A RAM 104 temporarily stores image data and the like. The nonvolatile memory 105 retains data even while the liquid ejecting apparatus 100 is powered off. The ASIC 106 processes various signal processing, image processing such as rearrangement, and input/output signals for controlling the entire apparatus.

Further, the control unit 101 includes an I/F 107, a print control unit 108, a main scanning motor driving unit 109, a sub-scanning motor driving unit 110, a fan control unit 111, a heater control unit 112, and an I/O 113. Prepare. Control unit 101 also connects operation panel 114 and environment sensor 115 .

The I/F 107 is an interface that transmits and receives data and signals to and from the host side. Specifically, the I/F 107 receives print data and the like generated by a printer driver of a host such as an information processing device, an image reading device, and an imaging device via a cable, network, or the like. That is, the print data may be generated and output to the control unit 101 by the printer driver on the host side. The CPU 102 reads and analyzes the print data in the receive buffer included in the I/F 107 . Then, the ASIC 106 performs image processing, data rearrangement processing, and the like, and the image data is transferred to the print control unit 108 and the head driver 116 .

The print control unit 108 generates drive waveforms for driving the liquid ejection head 122, and also provides image data and image data for selectively driving pressure generating means for generating pressure for the liquid ejection head 122 to eject liquid from the nozzles. Various data associated therewith are output to the head driver 116 .

The print control unit 108 may have a computer configuration including a CPU, ROM, RAM, and the like. The print control unit 108 exhibits desired functions by executing a program stored in a ROM or the like by the CPU.

A program executed by the CPU of the print control unit 108 is a file in an installable format or an executable format, and can be read by a computer such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk). It may be configured so as to be recorded on a recording medium and provided.

Furthermore, the program executed by the CPU of the print control unit 108 may be stored in a computer connected to a network such as the Internet, and provided by being downloaded via the network. Alternatively, the program executed by the CPU of the print control unit 108 may be provided or distributed via a network such as the Internet.

A main scanning motor drive unit 109 drives a main scanning motor 117 . The main scanning motor 117 is driven to move the carriage 121 having the liquid ejection head 122 in the main scanning direction. The sub-scanning motor driving section 110 drives the sub-scanning motor 118 . The sub-scanning motor 118 drives to operate the conveying roller 123 that conveys the object to be ejected liquid by the liquid ejection head 122 . Fan control unit 111 controls the output of fan 119 so as to blow air at a predetermined temperature and air volume.

Heater control unit 112 controls heater 120 so as to achieve a set temperature. In this embodiment, the heaters 120 correspond to a preheater 120a, a print heater 120b, a print heater 120c, a postheater 120d, and a drying heater 120e. Each heater 120 will be described later.

The I/O 113 acquires information from the environment sensor 115 and extracts information required for controlling each part of the liquid ejecting apparatus 100 . For example, the environmental sensor 115 detects environmental temperature, environmental humidity, and the like. Note that the I/O 113 also receives detection signals from various sensors other than the environment sensor 115 . Operation panel 114 is used to input and display various types of information.

Here, an outline of print control processing in the liquid ejection apparatus 100 will be described.

The CPU 102 of the liquid ejecting apparatus 100 reads and analyzes the print data in the reception buffer of the I/F 107 , performs necessary image processing, data rearrangement processing, etc. in the ASIC 106 and transfers the data to the print control unit 108 .

The print control unit 108 outputs image data and drive waveforms to the head driver 116 at required timing. More specifically, the print control unit 108 D/A-converts and amplifies the driving pulse pattern data stored in the ROM 103 and read out by the CPU 102, thereby generating a driving pulse composed of one driving pulse or a plurality of driving pulses. Generate a waveform.

Image data (for example, dot pattern data) for image output may be generated by storing font data in the ROM 103, for example, or by developing the image data into a bitmap using a printer driver on the host side. It may be transferred to the liquid ejection apparatus 100 .

The head driver 116 selectively applies drive pulses forming a drive waveform provided from the print control unit 108 to the pressure generating means of the liquid ejection head 122 based on input image data (for example, dot pattern data). is applied to drive the liquid ejection head 122 .

Next, the heater 120 according to Embodiment 1 will be described with reference to FIG. 2A and 2B are diagrams for explaining each heater 120 according to the first embodiment. FIG.

As shown in FIG. 2, the liquid ejecting apparatus 100 includes a fan 119, a preheater 120a, a print heater 120b, a print heater 120c, a postheater 120d, and a drying heater 120e. Further, the medium P is transported in the direction of arrow B by transport rollers 123a, 123b, etc. to which a driving force is applied from the sub-scanning motor 118, and the liquid is ejected from the liquid ejection head 122 to form a liquid coated surface. .

The medium P is set on the preheater 120a side. For example, as the medium P, in addition to roll-type paper, PET, PVC, OPP, sheet-like media, etc., which are called flexible packaging media, can be used. The medium P sent from the preheater 120a is first preheated by the preheater 120a to a temperature suitable for forming a liquid coating surface. For example, the preheater 120a (upper margin +2° C., lower margin 0° C.) is an aluminum foil cord heater, which is attached to the rear surface of the transport guide plate and warms the medium P by heating the transport guide plate itself. The preheated medium P is sent to the image forming section where the liquid ejection head 122 is arranged by the transport rollers 123a and 123b.

In the image forming section, while the medium P is kept warm by the print heaters 120b and 120c, liquid such as ink is ejected from the liquid ejection head 122 to form a liquid application surface. For example, the print heater 120b and the print heater 120c (upper margin +0.5° C., lower margin −0.5° C.) embed code heaters in a platen made of aluminum and warm the medium P by heating the platen itself. . The warmed air rises together with the vapor, and the fan 119 promotes convection of the air in order to prevent the upper portion of the liquid ejection device 100 from excessively increasing in temperature due to its retention.

The medium P on which the liquid application surface is formed is sent further downstream, and the liquid such as ink is dried and fixed by the post-heater 120d and the drying heater 120e that sends hot air. For example, the post-heater 120d (upper margin +2° C., lower margin 0° C.) is an aluminum foil cord heater, which is attached to the rear surface of the transport guide plate and heats the medium P by heating the transport guide itself. The drying heater 120e (upper margin +0.5° C., lower margin −0.5° C.) is an IR heater, and irradiates the liquid coated surface of the medium P with IR to dry it. The medium P, which has been dried and fixed, is wound into a roll further downstream.

Each of these heaters is provided with a thermistor for temperature control. Each heater lights up when waking up from the sleep mode, and is controlled to a set temperature according to the medium P and the mode. When the heaters are activated, the liquid ejection apparatus 100 is ready to form the liquid application surface, and starts the initial operation for forming the liquid application surface. The drying heater 120e starts lighting when the formation of the liquid application surface is started. It takes several tens of seconds for the medium P with the liquid coated surface to be transported to the drying heater 120e.

The drying heater 120e preheats the filament so that the temperature of the filament reaches the target temperature (the wavelength of the electromagnetic wave to be output) before the medium P having the liquid coated surface arrives. After that, when the medium P having the liquid coated surface arrives, the drying heater 120e is turned on in synchronization with the sub-scanning stop timing. The lighting timing can be changed according to the type and mode of the medium P. The reason why the drying heater 120e is not turned on at the same time as the sleep mode is canceled is to prevent deterioration of the medium P due to unnecessary radiation heating.

PET and PVC (an example of the medium P) were evaluated using an experimental machine as follows. Specifically, the pre-heater 120a, print-heater 120b, print-heater 120c, and post-heater 120d were each set to 50° C. to 80° C., and printing was attempted using the ink under test. The ink under test contains, for example, a heat shrinkable resin. As a result, the dot diameter was reduced due to the effects of the resin, which has excellent fixability and is easily heat-shrinkable, and a high-quality sample was obtained.

Here, as shown in FIG. 2, the liquid ejection head 122 includes a liquid ejection head 122a arranged upstream with respect to the transport direction of the medium P and a liquid ejection head 122a arranged downstream with respect to the transport direction of the medium P. There is a liquid ejection head 122b. The print heater 120b is arranged below the liquid ejection head 122a, and the print heater 120c is arranged below the liquid ejection head 122b. The liquid ejection head 122a corresponds to the "first liquid ejection head", and the liquid ejection head 122b corresponds to the "second liquid ejection head".

FIG. 3 is a top view of the carriage 121 according to the first embodiment. As shown in FIG. 3, the carriage 121 is mounted with a liquid ejection head 122a and a liquid ejection head 122b.

For example, the liquid ejection head 122a has nozzles that eject magenta (M), cyan (C), yellow (Y), black (K), and other inks forming a liquid coating surface on the medium P in the sub-scanning direction (medium It has a plurality of nozzle rows arranged in the P transport direction). Further, the liquid ejection head 122a is arranged upstream of the liquid ejection head 122b with respect to the transport direction of the medium P. As shown in FIG. A print heater 120b that heats the liquid-coated surface of the medium P is arranged below the liquid ejection head 122a (back surface of the medium P). That is, the print heater 120b is arranged upstream of the print heater 120c with respect to the direction in which the medium P is conveyed. The print heater 120b corresponds to the "first heating mechanism".

For example, the liquid ejection head 122b has nozzles that eject magenta (M), cyan (C), yellow (Y), black (K), and other inks forming a liquid coating surface on the medium P in the sub-scanning direction (medium It has a plurality of nozzle rows arranged in the P transport direction). Further, the liquid ejection head 122b is arranged downstream of the liquid ejection head 122a with respect to the direction in which the medium P is transported. A print heater 120c that heats the liquid-coated surface of the medium P is arranged below the liquid ejection head 122b (back surface of the medium P). That is, the print heater 120c is arranged downstream of the print heater 120b in the medium P transport direction. The print heater 120c corresponds to the "second heating mechanism".

FIG. 4 is a block diagram showing a functional configuration example of the liquid ejection device 100 according to the first embodiment.

As shown in FIG. 4 , the liquid ejection device 100 has a temperature control section 11 and a drive control section 12 . The temperature control section 11 is one of the functions of the heater control section 112 described above. Also, the drive control unit 12 is one of the functions of the print control unit 108 and the head driver 116 described above.

The temperature control unit 11 controls setting of heating temperatures of the print heater 120b and the print heater 120c. More specifically, the temperature control unit 11 controls the setting of the heating temperatures of the print heaters 120b and 120c based on the temperature dependence of the dot diameter of the ink formed on the medium P. FIG.

FIG. 5 is a diagram illustrating an example of the relationship between heater temperature and dot diameter according to the first embodiment. The ink used in this embodiment contains a resin that increases the dot diameter when heated. Therefore, as shown in FIG. 5, the higher the heating temperature of the heater, the larger the dot diameter. In other words, the lower the heating temperature of the heater, the smaller the dot diameter.

In general, the granularity of a liquid-coated surface formed on a medium or the like tends to decrease as the dot diameter decreases. In other words, the smaller the dot diameter, the more accurate the image can be obtained. However, it is inefficient to form a solid image with small dots, and it is desirable to form a solid image with large dots. In order to form a large dot, there is a method of providing a head with a nozzle for forming a large dot on a medium, or combining a plurality of droplets ejected from a nozzle of the head in the air.

For these reasons, the ink ejected from the liquid ejection head 122a or the liquid ejection head 122b has temperature dependence of the dot diameter, and is blended so that the dot diameter becomes larger at the location where the temperature is set higher by heating with the heater. there is For example, the temperature control unit 11 controls the setting of the heating temperature of the print heater 120b to be lower than the setting of the heating temperature of the print heater 120c. In other words, the temperature control unit 11 controls the heating temperature of the print heater 120b (to a low temperature) so that the dot diameter becomes less than the predetermined diameter at locations where the image density is less than the predetermined value. Similarly, the temperature control unit 11 controls the heating temperature of the print heater 120c (to a high temperature) so that the dot diameter becomes equal to or greater than a predetermined diameter at locations where the image density is equal to or greater than a predetermined value.

A liquid ejection head 122a arranged above the print heater 120b, which is set to a low temperature, ejects to form smaller dots on the medium P, and mainly corresponds to portions with low image density. Further, the liquid ejection head 122b arranged above the print heater 120c, which is set to a high temperature, performs ejection for forming larger dots (unified solid portions of high density) on the medium P, and mainly , to correspond to a portion with high image density. When the liquid ejection head 122 is singular (not divided into the liquid ejection head 122a and the liquid ejection head 122b), the print heads arranged below the liquid ejection head 122 on the upstream side and the downstream side of the liquid ejection head 122 respectively. It is sufficient if the temperature control of the heater 120b and the print heater 120c are different.

The drive control unit 12 controls driving of the liquid ejection heads 122a and 122b. More specifically, the drive control unit 12 controls the liquid ejection head 122a by a waveform configuration that ejects droplets (smaller droplets) having a diameter less than a predetermined value in portions where the image density is less than a predetermined value (low). control the drive. Further, the drive control unit 12 controls driving of the liquid ejection head 122b by a waveform configuration that ejects droplets (larger droplets) having a predetermined diameter or more in a portion where the image density is a predetermined value or more (high). . At this time, the liquid ejection head 122a and the liquid ejection head 122b are assumed to be capable of forming multi-valued ejection droplets, for example four-valued ejection droplets of large droplet, medium droplet, small droplet, and none.

If the liquid ejection head 122a and the liquid ejection head 122b can form multi-valued ejection droplets, the droplet sizes are at least partially overlapped. For example, the liquid ejection head 122a can form ejection droplets with droplet sizes such as 5 pL, 10 pL, and 15 pL. Also, the liquid ejection head 122b can form ejection droplets with droplet sizes such as 7 pL, 14 pL, and 21 pL. As a result, the ink is evenly ejected from the two heads regardless of whether the image density is low or high, so it is possible to suppress the occurrence of ejection crookedness and non-ejection due to drying of the nozzle surface. can. At this time, the print heater 120b and the print heater 120c are preferably controlled at the same temperature, or the print heater 120c is controlled at a slightly higher temperature.

In addition to controlling the driving of the liquid ejection heads 122a and 122b by the waveform configuration, heads with different nozzle diameters may be used together. That is, the nozzle diameter of the liquid ejection head 122a is configured to be large enough to eject droplets smaller than a predetermined diameter (smaller droplets), and the nozzle diameter of the liquid ejection head 122b is configured to eject droplets larger than the predetermined diameter. ) may be configured to discharge.

Further, the driving waveforms of the liquid ejection heads 122a and 122b may be less than the four values described above. For example, the liquid ejection head 122a may be capable of forming ejection droplets with a droplet size of none, 5 pL, 10 pL, or the like. Also, the liquid ejection head 122b may be configured to form ejection droplets with a droplet size of 14 pL, 21 pL, or the like. That is, the droplet sizes of the liquid ejected by the liquid ejection head 122a and the liquid ejection head 122b are not overlapped, and the types of droplet sizes are reduced from the four values. As a result, the liquid ejecting apparatus 100 can shorten the waveform length of the drive waveform, thereby increasing the scanning speed and improving the productivity.

Moreover, in the above description, the case of using ink containing a resin that easily shrinks due to heat is taken as an example, but the present invention is not limited to this. For example, the liquid ejection head 122a may use an ink containing a resin that easily shrinks, and the liquid ejection head 122b may use an ink containing a resin that does not easily shrink. In other words, by assigning the liquid ejection head 122a to form small dots and the liquid ejection head 122b to form large dots, higher image quality can be achieved.

As described above, the liquid ejection apparatus 100 includes the print heater 120b arranged below the liquid ejection head 122a on the upstream side in the medium P transport direction, and the print heater 120b arranged below the liquid ejection head 122b on the downstream side in the medium P transport direction. It has a print heater 120c arranged, and controls the setting of the heating temperature of each heater based on the temperature dependence of the dot diameter. As a result, the liquid ejection apparatus 100 can achieve both high density and good graininess while maintaining high productivity. In other words, the liquid ejection apparatus 100 forms dots of temperature-dependent ink on the liquid application surface so that the dot diameter is large in locations where the density is desired to be high, and the dot diameter is small in locations where the granularity is desired to be reduced. Since the size is adjusted by the temperature of each heater, it is possible to achieve both high density and good graininess while maintaining high productivity.

Information including processing procedures, control procedures, specific names, various data and parameters shown in the above documents and drawings can be arbitrarily changed unless otherwise specified. Also, each component of the illustrated apparatus is functionally conceptual, and does not necessarily need to be physically configured as illustrated. That is, the specific form of distributing or integrating the devices is not limited to the illustrated one, and all or part of them can be functionally or physically distributed or integrated in arbitrary units according to various loads and usage conditions. can be integrated.

Further, the liquid ejection apparatus 100 described in the above embodiment is an apparatus that includes a liquid ejection head or a liquid ejection unit, drives the liquid ejection head, and ejects liquid. Devices that eject liquid include not only devices that can eject liquid onto an object to which liquid can adhere, but also devices that eject liquid into air or liquid.

Such a liquid ejecting apparatus 100 can also include means for feeding, transporting, and discharging an object to which liquid can adhere, as well as a pre-processing device, a post-processing device, and the like.

Examples of the liquid ejecting apparatus 100 include an image forming apparatus that ejects ink to form an image on a sheet of paper, and a powder layer that forms a layer of powder in order to form a three-dimensional object (three-dimensional object). There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that ejects a modeling liquid.

Further, the liquid ejecting apparatus 100 is not limited to one that visualizes significant images such as characters and graphics with the ejected liquid. For example, it includes those that form patterns that have no meaning per se, and those that form three-dimensional images.

The above-mentioned "substance to which a liquid can adhere" means a substance to which a liquid can adhere at least temporarily, such as a substance to which a liquid adheres and adheres, a substance which adheres and permeates, and the like. Specific examples include recording media such as paper, recording paper, recording paper, film, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, and testing cells. , unless otherwise specified, includes anything to which a liquid adheres.

The material of the above-mentioned "material to which liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as liquid can adhere even temporarily.

In addition, the "liquid" is not particularly limited as long as it has a viscosity and surface tension that can be discharged from the head, but it should have a viscosity of 30 mPa·s or less at normal temperature and pressure, or by heating or cooling. Preferably. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional-imparting materials such as polymerizable compounds, resins, and surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, etc., including solutions, suspensions, emulsions, etc. These are, for example, inkjet inks, surface treatment liquids, components of electronic elements and light emitting elements, and formation of electronic circuit resist patterns It can be used for applications such as liquids for liquids and material liquids for three-dimensional modeling.

Further, although the liquid ejection apparatus 100 includes an apparatus in which the liquid ejection head and an object to which liquid can be adhered move relatively, the present invention is not limited to this. Specific examples include a serial type apparatus in which the liquid ejection head is moved and a line type apparatus in which the liquid ejection head is not moved.

In addition to the liquid ejecting apparatus 100, a processing liquid coating apparatus that ejects the processing liquid onto the paper to apply the processing liquid to the surface of the paper for the purpose of modifying the surface of the paper, and a raw material in the solution. There is an injection granulator that granulates fine particles of a raw material by injecting a composition liquid dispersed in a liquid through a nozzle.

Reference Signs List 11 temperature control unit 12 drive control unit 100 liquid ejection device 120b print heater 120c print heater 122 liquid ejection head 122a liquid ejection head 122b liquid ejection head

JP 2015-186919 A

Claims (9)

A nozzle row in which a plurality of nozzles are arranged in the conveying direction of the object based on the input data and form a liquid coating surface by ejecting a liquid containing a component that increases the dot diameter as the heating temperature increases. a liquid ejection head having
Among a plurality of heating mechanisms for heating the liquid application surface, which are arranged below the liquid ejection head and behind the liquid application surface, the first heating mechanism is arranged on the upstream side with respect to the conveying direction of the object. 1 heating mechanism;
Among a plurality of heating mechanisms for heating the liquid application surface, which are arranged below the liquid ejection head and behind the liquid application surface, the first heating mechanism is arranged on the downstream side with respect to the conveying direction of the object. 2 heating mechanism;
a temperature control unit that controls setting of heating temperatures of the first heating mechanism and the second heating mechanism based on the temperature dependence of the dot diameter of the liquid application surface ;
The temperature control unit controls the setting of the heating temperature so that the dot diameter becomes less than a predetermined diameter at locations where the density of the liquid application surface is less than a predetermined value from the input data, and controls the setting of the liquid from the input data. The setting of the heating temperature is controlled so that the dot diameter is equal to or greater than a predetermined diameter at locations where the density of the coating surface is equal to or greater than a predetermined value.
A liquid ejection device characterized by: The liquid ejection head is
a first liquid ejection head arranged above the first heating mechanism;
2. The liquid ejection apparatus according to claim 1 , further comprising a second liquid ejection head arranged above the second heating mechanism. 3. The liquid ejection apparatus according to claim 2 , further comprising a drive control section that controls driving of the first liquid ejection head and the second liquid ejection head with different waveform configurations. 4. The liquid ejection apparatus according to claim 2 , wherein the nozzle diameter of the first liquid ejection head is different from the nozzle diameter of the second liquid ejection head. 5. The liquid ejection apparatus according to claim 3 , wherein droplet sizes of the liquid ejected by the first liquid ejection head and the droplet size of the liquid ejected by the second liquid ejection head overlap at least partially. 5. The method according to claim 3 or 4 , wherein droplet sizes of the liquid ejected by the first liquid ejection head and the second liquid ejection head are not overlapped, and types of droplet sizes are reduced. A liquid ejection device as described. The drive control unit controls driving of the first liquid ejection head by a waveform configuration for ejecting droplets having a dot diameter smaller than a predetermined diameter, and ejects droplets having a dot diameter equal to or larger than the predetermined diameter. 4. The liquid ejection apparatus according to claim 3 , wherein driving of the second liquid ejection head is controlled by a waveform configuration. the first liquid ejection head has the nozzle for ejecting droplets having a dot diameter smaller than a predetermined diameter;
5. The liquid ejection apparatus according to claim 4 , wherein the second liquid ejection head has the nozzles for ejecting droplets having a dot diameter equal to or greater than a predetermined diameter. 8. The temperature control unit controls the setting of the heating temperature of the first heating mechanism so as to be lower than the setting of the heating temperature of the second heating mechanism. 9. The liquid ejection device according to 8 .

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