JP2019177657A - Liquid discharge device, control method and control program - Google Patents

Abstract

To provide a liquid discharge device which improves an image quality while assuring productivity.SOLUTION: A liquid discharge device 100 has a liquid discharge head for discharging a liquid, and carriage on which the liquid discharge head is mounted. The liquid discharge device has: a drive frequency control part 101 which controls a drive frequency, at which the liquid discharge head is driven in a frequency region range in which a liquid discharge quantity is changed, to a different value by reciprocating scan in a main scan direction of the carriage; and a movement control part 102 which controls a travel speed of the carriage in said reciprocating scan.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a liquid ejection apparatus, a control method, and a control program.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses that perform bidirectional printing by ejecting ink from an ink jet head are known. For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2000-296648), when bidirectional printing is performed, the timing of ink ejection is shifted by changing the frequency of the drive signal between the forward path and the backward path, and the shift of the recording position is detected. Techniques for adjustment are disclosed.

  However, since the conventional technique does not change the drive frequency in the frequency region where the ink ejection amount changes, the size of the ink droplet cannot be reduced, and it is difficult to improve the image quality. In order to improve the image quality, it is conceivable to operate the carriage at a low speed in bidirectional printing, but the productivity is lowered.

  The present invention has been made in view of the above, and an object of the present invention is to improve image quality while ensuring productivity.

  In order to solve the above-described problems and achieve the object, a liquid discharge apparatus according to the present invention includes a liquid discharge head that discharges a liquid, a carriage on which the liquid discharge head is mounted, and a frequency at which the discharge amount of the liquid changes. A reciprocating scan of the carriage based on the drive frequency, and a drive frequency control unit that controls a drive frequency for driving the liquid ejection head to a different value in a reciprocating scan in the main scanning direction of the carriage in a region range And a movement control unit for controlling the movement speed at

  According to the present invention, it is possible to improve the image quality while ensuring the productivity.

FIG. 1 is a plan view illustrating an example of a mechanism unit of the liquid ejection apparatus according to the first embodiment. FIG. 2 is a diagram illustrating an example of a side surface of a main part of the liquid ejection apparatus according to the first embodiment. FIG. 3 is a block diagram illustrating an example of a device configuration of the liquid ejection device according to the first embodiment. FIG. 4 is a block diagram illustrating 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 the ink droplet amount and the drive frequency according to the first embodiment. FIG. 6 is a diagram for explaining an example of the size of dots of ink droplets ejected by the liquid ejection head according to the first embodiment.

  Hereinafter, embodiments of a liquid ejection apparatus, a control method, and a control program according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following embodiments.

(Embodiment 1)
FIG. 1 is a plan view illustrating an example of a mechanism unit of the liquid ejection apparatus 100 according to the first embodiment. FIG. 2 is a diagram illustrating an example of a side surface of a main part of the liquid ejection apparatus 100 according to Embodiment 1.

  As shown in FIG. 1, the liquid ejection device 100 includes a guide member 11, a drive pulley 12, a driven pulley 13, a timing belt 14, a side plate 15A, a side plate 15B, a back plate 15C, a carriage 160, A liquid discharge head 165 and a main scanning motor 140 are included.

  The guide member 11 spans the left and right side plates (side plate 15A and side plate 15B) of the main body of the liquid ejection apparatus 100, and holds the carriage 160 so as to be movable in the main scanning direction. The timing belt 14 is stretched between the driving pulley 12 and the driven pulley 13, and a part thereof is fixed or in contact with the carriage 160. When the main scanning motor 140 mounted on the back plate 15C side is driven, the carriage 160 reciprocates in the main scanning direction (that is, the carriage movement direction).

  The carriage 160 includes a liquid ejection head 165. For example, the liquid discharge head 165 can be a piezoelectric actuator such as a piezoelectric element, or a thermal actuator that uses a phase change for liquid film boiling using an electrothermal transducer such as a heating resistor.

  As shown in FIG. 2, the lower portion of the liquid discharge head 165 is disposed so as to be exposed from the carriage 160 and to face the conveyance belt 170. The liquid discharge head 165 includes a nozzle row in which a plurality of recording elements (nozzles) are arranged.

  As shown in FIG. 2, the liquid ejection apparatus 100 includes a conveyance belt 170, a conveyance roller 21, and a tension roller 22. The conveyance belt 170 is a conveyance unit that adsorbs an object to be ejected such as a sheet material and conveys it at a position facing the liquid ejection head 165. The conveyor belt 170 is an endless belt and is stretched between the conveyor roller 21 and the tension roller 22. A sub-scanning motor 150 (to be described later) rotates the conveyance roller 21 so that the conveyance belt 170 rotates in the sub-scanning direction, and the sheet material on the conveyance belt 170 is conveyed in the sub-scanning direction.

  By combining the liquid ejection method described above, the movement of the carriage 160 in the main scanning direction, and the movement of the sheet material or the like in the sub-scanning direction, image formation (formation of a liquid application surface) on the sheet material or the like is performed. can do. More specifically, the liquid ejection head 165 is driven while moving the carriage 160 in the main scanning direction, thereby ejecting liquid onto a stopped sheet material or the like to record an image for one line. Here, in the case of multi-pass image formation, at least one row of images is recorded in the forward path and the backward path. Next, after the sheet material or the like is moved by a predetermined amount in the sub-scanning direction, the next line is recorded. By repeating these steps, an image can be formed on the entire sheet material.

  FIG. 3 is a block diagram illustrating an example of a device configuration of the liquid ejection device 100 according to the first embodiment.

  As illustrated in FIG. 3, the control unit 120 includes a CPU (Central Processing Unit) 121, a ROM (Read Only Memory) 122, and a RAM (Random Access Memory) 123. The CPU 121 controls the entire liquid ejecting apparatus 100. The ROM 122 stores fixed data such as a program executed by the CPU 121. The RAM 123 temporarily stores image data and the like.

  The control unit 120 includes an NVRAM (Non-Volatile RAM) 124 and an ASIC (Application Specific Integrated Circuit) 125. The NVRAM 124 is a non-volatile memory that retains data even when the power of the liquid ejection apparatus 100 is shut off. The ASIC 125 processes input / output signals for controlling the liquid ejecting apparatus 100 as a whole, as well as image processing for performing various signal processing and rearrangement on image data.

  The control unit 120 includes a print control unit 127. The carriage 160 includes a liquid ejection head 165. The print control unit 127 transfers data for driving the liquid ejection head 165 to the head driver 130. The head driver 130 drives a liquid discharge head 165 provided on the carriage 160 to discharge liquid from the liquid discharge head 165.

  The control unit 120 has a motor drive unit 128. The motor driving unit 128 drives the main scanning motor 140 and the sub scanning motor 150. The main scanning motor 140 moves and scans the carriage 160 by driving. The sub-scanning motor 150 rotates to move the transport belt 170 around.

  The control unit 120 has an I / O 129. The I / O 129 acquires information from the sensor 190 and extracts information used for controlling each part of the liquid ejection apparatus 100 main body. For example, the sensor 190 corresponds to a sensor group such as a photo sensor, a temperature sensor, and an encoder sensor. The operation panel 180 inputs and outputs various information.

  The control unit 120 has a host I / F 126. The host I / F 126 transmits and receives data and signals to and from the host side. Specifically, data and signals are transmitted and received via a cable or a network from the printer driver 110 side of a host such as an information processing apparatus such as a client PC, an image reading apparatus, or an imaging apparatus. The CPU 121 reads and analyzes the print data in the reception buffer included in the host I / F 126. The ASIC 125 performs image processing, data rearrangement processing, and the like, and the image data is transferred from the print control unit 127 to the head driver 130.

  The print control unit 127 transfers the image data as serial data, and outputs a transfer clock, a latch signal, a control signal, and the like required for the transfer of the image data to the head driver 130. The head driver 130 generates a drive pulse that forms a drive waveform supplied from the print control unit 127 based on image data corresponding to one line of the liquid discharge head 165 that is input serially, and generates a pressure for the liquid discharge head 165. Give selectively to the means. As a result, the liquid discharge head 165 is driven to discharge the liquid. By selecting some or all of the pulses that make up the drive waveform and some or all of the waveform elements that form the pulses, for example, large dots, medium drops, small drops, etc. Can be categorized.

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

  As illustrated in FIG. 4, the liquid ejection apparatus 100 includes a drive frequency control unit 101 and a movement control unit 102.

  The drive frequency control unit 101 controls the drive frequency for driving the liquid discharge head 165 to a different value in the reciprocating scan in the main scanning direction of the carriage 160 within a frequency range where the liquid discharge amount changes. As described above, the liquid ejection head 165 can sort dots having different sizes such as large droplets, medium droplets, and small droplets. The drive frequency control unit 101 drives the liquid ejection head 165 on the forward and backward paths in the main scanning direction of the carriage 160 in a frequency range where the liquid ejection amount changes in addition to such dot placement. Control the drive frequency to a different value.

  FIG. 5 is a diagram illustrating an example of the relationship between the ink droplet amount and the drive frequency according to the first embodiment. Note that the ink droplet amount shown in FIG. 5 is different from the above-described dot placement with different sizes such as large droplets, medium droplets, and small droplets. For example, even when a large droplet is ejected, it means that a dot smaller than a large droplet (however, a dot larger than a medium droplet) can be ejected by changing the drive frequency.

  As shown in FIG. 5, the amount of ink droplets ejected from the liquid ejection head 165 changes according to the drive frequency of the liquid ejection head 165. For example, in FIG. 5, the driving frequency in the vicinity of 10 kHz to 20 kHz is a range of the frequency region in which the ink droplet amount (liquid ejection amount) changes. Specifically, the ink droplet amount when the driving frequency is 15 kHz is smaller than the ink droplet amount when the driving frequency is 20 kHz. From these, for example, when ejecting large droplets, if the drive frequency is controlled to 20 kHz, large droplets of the same size will be ejected, but if the drive frequency is controlled to 15 kHz, droplets smaller than large droplets will be ejected. It can be discharged.

  From such a relationship, for example, the drive frequency control unit 101 controls the drive frequency to 20 kHz on the forward path of the carriage 160 in the main scanning direction, and controls the drive frequency to 15 kHz on the return path. In such a case, the amount of ink droplets in the return path is smaller than that in the forward path, and smaller dot drops can be ejected. If droplets of smaller dots can be ejected, the graininess can be improved and the image quality can be improved. It should be noted that droplets of smaller dots may be ejected either on the forward path or on the return path. That is, the drive frequency control unit 101 may control the drive frequency to 15 kHz on the forward path of the carriage 160 in the main scanning direction and may control the drive frequency to 20 kHz on the return path.

  The movement control unit 102 controls the movement speed in the reciprocating scanning of the carriage 160 based on the driving frequency. More specifically, the movement control unit 102 controls the moving speed of the carriage 160 between the forward path and the return path based on the driving frequency controlled by the driving frequency control unit 101. When the drive frequency of the liquid discharge head 165 is controlled by the drive frequency control unit 101, the amount of ink droplets discharged from the liquid discharge head 165 changes and the time width for discharging ink also changes. For example, as the driving frequency is decreased, the time width for ejecting ink becomes longer.

  Therefore, for example, when the drive frequency control unit 101 controls the drive frequency to 20 kHz on the forward path in the main scanning direction of the carriage 160 and the drive frequency is controlled to 15 kHz on the return path, the movement control unit 102 has a carriage on the return path rather than the forward path. The moving speed of 160 is controlled to be slow. That is, the movement control unit 102 controls the movement speed of the carriage 160 in accordance with the drive frequency control by the drive frequency control unit 101. In addition, although the path | route which makes the moving speed of the carriage 160 slow is generated according to controlling a drive frequency to a different value by a forward path and a return path, the movement of the carriage 160 is carried out by all the paths of a forward path and a return path. Since the speed is not slowed down, a certain level of productivity can be secured.

  In this respect, in order to improve productivity, the above-described processing may be performed for each predetermined number of lines. Specifically, the drive frequency control unit 101 may control the drive frequency to a different value by reciprocating scanning of the carriage 160 for each predetermined number of lines. For example, the drive frequency control unit 101 controls the drive frequency to a different value by reciprocating scanning of the carriage 160 every three lines. That is, since a smaller dot drop can be ejected for each predetermined number of lines, the image quality as a whole can be improved.

  FIG. 6 is a diagram for explaining an example of the size of dots of ink droplets ejected by the liquid ejection head 165 according to the first embodiment. FIG. 6 shows an example in which the drive frequency on the return path is smaller than the forward path.

  For example, as shown in FIG. 6, when the drive frequency in the return path is smaller than the forward path, ejection is performed with a drop size of one of a large droplet, a medium droplet, and a small droplet on the forward path and the return path in the main scanning direction of the carriage 160. Even so, dots having a smaller droplet size are ejected in the return path than in the forward path.

  As described above, the liquid ejection apparatus 100 controls the driving frequency of the liquid ejection head 165 to a different value in the reciprocating scanning of the carriage 160 in the main scanning direction, and controls the moving speed of the carriage 160 according to the driving frequency. As a result, the liquid ejection apparatus 100 can improve image quality while ensuring productivity.

  In addition, since the liquid ejection apparatus 100 controls the driving frequency to a different value by reciprocating scanning of the carriage 160 for each predetermined number of lines, it is possible to ensure a constant image quality while further improving productivity.

  Information including processing procedures, control procedures, specific names, various data, parameters, and the like shown in the above documents and drawings can be arbitrarily changed unless otherwise specified. 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 the distribution or integration of the devices is not limited to the illustrated one, and all or a part of the distribution or integration is functionally or physically distributed or arbitrarily in any unit according to various burdens or usage conditions. Can be integrated.

  In addition, the control program executed by the liquid ejection apparatus 100 may be a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disk) in one installable or executable file. And the like recorded on a computer-readable recording medium. In addition, the control program executed by the liquid ejection apparatus 100 may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The control program executed by the liquid ejection apparatus 100 may be provided or distributed via a network such as the Internet. Further, the control program executed by the liquid ejection apparatus 100 may be provided by being incorporated in advance in a ROM or the like.

  The control program executed by the liquid ejection apparatus 100 has a module configuration including the above-described units (the drive frequency control unit 101 and the movement control unit 102). As actual hardware, a CPU (processor) is loaded from a storage medium. By reading and executing the control program, the above-described units are loaded on the main storage device, and the drive frequency control unit 101 and the movement control unit 102 are generated on the main storage device.

  In addition, the liquid discharge apparatus 100 described in the above embodiment is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

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

  For example, as the liquid ejecting apparatus 100, an image forming apparatus that is an apparatus that ejects ink to form an image on a sheet, or a powder layer in which powder is formed in a layered manner to form a three-dimensional structure (three-dimensional structure). There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid.

  Further, the liquid ejecting apparatus 100 is not limited to an apparatus in which significant images such as characters and figures are visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  The above-mentioned “applicable liquid” means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film and cloth, electronic parts such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, examination cells, and other media. Unless otherwise specified, everything to which liquid adheres is included.

  The material of the above-mentioned “adherable liquid” may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as the liquid can be adhered even temporarily.

  The “liquid” is not particularly limited as long as it has a viscosity and surface tension that can be ejected from the head, but the viscosity becomes 30 mPa · s or less at room temperature, normal pressure, or by heating and cooling. Preferably there is. More specifically, solvents such as water and organic solvents, colorants such as dyes and pigments, functional materials such as polymerizable compounds, resins, and surfactants, and biocompatible materials such as DNA, amino acids, proteins, and calcium. , Edible materials such as natural pigments, solutions, suspensions, emulsions, etc., which include, 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 in applications such as liquids for use, three-dimensional modeling material liquids, and the like.

  In addition, the liquid discharge apparatus 100 includes an apparatus in which the liquid discharge head and the apparatus to which the liquid can be attached move relatively, but is not limited thereto. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  In addition, the liquid ejecting apparatus 100 includes a processing liquid applying apparatus that discharges a processing liquid onto a sheet in order to apply the processing liquid to the surface of the sheet for the purpose of modifying the surface of the sheet, and the raw materials in the solution. There is an injection granulator for spraying the composition liquid dispersed in the above through a nozzle to granulate fine particles of raw materials.

DESCRIPTION OF SYMBOLS 100 Liquid discharge apparatus 101 Drive frequency control part 102 Movement control part 160 Carriage 165 Liquid discharge head

JP 2000-296648 A

Claims (4)

A liquid discharge head for discharging liquid;
A carriage on which the liquid discharge head is mounted;
A drive frequency control unit that controls a drive frequency for driving the liquid discharge head to a different value in a reciprocating scan in the main scanning direction of the carriage within a frequency range in which the liquid discharge amount changes;
And a movement control unit that controls a movement speed of the carriage in the reciprocating scanning based on the driving frequency. The liquid ejection apparatus according to claim 1, wherein the drive frequency control unit controls the drive frequency to a different value in the reciprocating scan for each predetermined number of lines. A control method executed in a liquid ejection device,
The step of controlling the driving frequency for driving the liquid discharge head for discharging the liquid to a different value in the reciprocating scan in the main scanning direction of the carriage on which the liquid discharge head is mounted in the frequency range where the liquid discharge amount changes. When,
And a step of controlling a moving speed of the carriage in the reciprocating scanning based on the driving frequency. On the computer,
Controlling the drive frequency for driving the liquid discharge head for discharging the liquid to a different value in the reciprocating scan in the main scanning direction of the carriage on which the liquid discharge head is mounted in the range of the frequency region in which the liquid discharge amount changes; ,
And a step of controlling a moving speed of the carriage in the reciprocating scanning based on the driving frequency.

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