Liquid discharge head, liquid discharge unit, liquid discharge device, liquid discharge method and program

Abstract

To uniformize image qualities of nozzle overlap regions of head end parts of liquid discharge heads adjacently arranged.SOLUTION: A liquid discharge head comprises a plurality of heads in which nozzle rows constituted of a plurality of nozzles is arranged and which makes the nozzles selectively discharge liquid droplets, in which the heads adjacently arranged are installed so that nozzle overlap regions are set in end parts in a row direction of the nozzle row. The liquid discharge head further comprises a discharge control part that with respect to mask patterns of the nozzle overlap regions, constitutes data on a direction parallel to the row direction of the nozzle row of both pixel data created by one head of the plurality of heads and pixel data created by the other head of the plurality of heads, and constitutes data on a direction crossing the row direction of the nozzle row of either of the pixel data created by the one head and the pixel data created by the other head. The discharge control part sets the number of dots that are discharged from the same head, which continue in the direction crossing the row direction of the nozzle row, to be below a predetermined number of dots.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a liquid ejection head, a liquid ejection unit, an apparatus for ejecting a liquid, a liquid ejection method, and a program.

Background Art

[0002] Conventionally, a technique related to image processing of a nozzle overlap region at an end of an adjacent liquid ejection head has been considered and is already known.

[0003] Patent Document 1 discloses a technique for suppressing deterioration in image quality of a nozzle overlap region of a liquid ejection head by applying a mask to the nozzle overlap region and forming an image by mixing printing dots with two liquid ejection heads.

[0004] Patent Document 2 discloses a technique in which, in a nozzle overlap region, a row of dots in the Y direction is formed by both a head end of one liquid ejection head and a head end of another liquid ejection head. By doing so, it is possible to suppress a change in density in the nozzle overlap region more than when it is composed of only the head end of one liquid ejection head.

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when printing dots are distributed in the nozzle overlap region of two liquid ejection heads as in the conventional technology, the driving frequency per nozzle decreases compared to the normal nozzle region outside the nozzle overlap region. Generally, since the ejection droplet volume of a liquid ejection head often varies according to the driving frequency, the dot size of the printing dots changes in the masked nozzle overlap region. There has been a problem that a portion where the dot size of the printing dots has changed in the nozzle overlap region is visually recognized as density unevenness or streaks.

[0006] Also, in the nozzle overlap region where the mask is applied, it is ideal for the printed dots ejected from the two liquid ejection heads to land at the ideal positions. However, due to the misalignment between the two liquid ejection heads and the difference in droplet velocity, if the landing position of the printed dots of one of the liquid ejection heads is shifted relatively, it becomes impossible to achieve the same density as in the normal nozzle region. There was also a problem that the portion where the same density as in the normal nozzle region could not be achieved was also visually recognized as density unevenness or streaks.

[0007] In addition, recent liquid ejection heads have very little manufacturing variation between the liquid ejection heads due to the utilization of semiconductor processes and the like. Since the variation in frequency characteristics is much larger than the variation between the liquid ejection heads, a mask that cancels the influence of frequency characteristics is effective.

[0008] The present invention has been made in view of the above, and an object thereof is to uniformize the image quality in the nozzle overlap region at the head end of adjacent liquid ejection heads.

Means for Solving the Problems

[0009] In order to solve the above-described problems and achieve the object, the present invention has a plurality of heads that arrange a nozzle row composed of a plurality of nozzles and selectively eject droplets from the nozzles, and adjacent ones of the heads are provided with a nozzle overlap region at an end in the row direction of the nozzle row. In the liquid ejection head installed, for the mask pattern in the nozzle overlap region, data in a direction parallel to the row direction of the nozzle row is composed of both pixel data by one of the plurality of heads and pixel data by the other of the plurality of heads, and data in a direction intersecting the row direction of the nozzle row is composed of either pixel data by the one head or pixel data by the other head. A discharge control unit is provided, and the discharge control unit sets the number of dots continuously ejected from the same head in a direction intersecting the row direction of the nozzle row to be equal to or less than a predetermined number of dots.

Effects of the Invention

[0010] According to the present invention, there is an effect that the image quality of the nozzle overlap region at the head end of adjacent liquid ejection heads can be made uniform.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0012] Hereinafter, embodiments of a liquid ejection head, a liquid ejection unit, an apparatus for ejecting a liquid, a liquid ejection method, and a program will be described in detail with reference to the accompanying drawings.

[0013] Hereinafter, as an example of an apparatus that discharges a liquid to which the present invention is applied, an image forming apparatus which is an aspect of the apparatus that discharges a liquid will be described as an example, but the present invention is not limited thereto.

[0014] (First Embodiment) FIG. 1 is a perspective view showing an internal structure of an image forming apparatus 100 according to the first embodiment in a transparent manner. FIG. 2 is a diagram showing an outline of the configuration of the image forming apparatus 100. As shown in FIGS. 1 and 2, the image forming apparatus 100 according to the present embodiment is a wide-width serial type inkjet recording apparatus.

[0015] In the present embodiment, an example in which the apparatus for discharging the liquid of the present invention is applied to a wide-width serial type inkjet will be described. However, the present invention can be applied to any image forming apparatus such as a multifunction peripheral having at least two functions among a copying function, a printer function, a scanner function, and a facsimile function, a copier, a printer, a scanner apparatus, and a facsimile apparatus.

[0016] As shown in FIGS. 1 and 2, the image forming apparatus 100 includes side plates 21A and 21B on the left and right of the apparatus main body 100a. The side plates 21A and 21B horizontally support a main guide rod 31 which is a guide member. The image forming apparatus 100 also includes a sub sheet metal guide 32. The main guide rod 31 and the sub sheet metal guide 32 slidably hold a carriage 121.

[0017] The carriage 121 moves in the direction of arrow Y (main scanning direction) via a timing belt that is rotationally driven by a main scanning motor 117 (see FIG. 3), and thereby relatively moves with respect to the medium 40. The movement of the carriage 121 can also be referred to as scanning. Further, the carriage 121 is equipped with an optical sensor 37 that detects an end portion (paper end portion) of the medium 40.

[0018] The optical sensor 37 is an example of a reading unit that outputs a reading signal of an image previously formed on the medium 40 by the image forming apparatus 100. As the optical sensor 37, a device that detects by reflection density, a camera that images an image formed on the medium 40, or the like can be used.

[0019] The carriage 121 is provided with heads 122a, 122b, 122c (these three heads 122a, 122b, 122c are collectively referred to as the "liquid ejection head 122") for ejecting ink droplets (liquids) of various colors such as yellow (Y), cyan (C), magenta (M), black (K), orange (O), green (G), and clear (Cl) according to the mounted ink cartridge 10.

[0020] The medium 40 moves along the sub-scanning direction (the direction of arrow X), which is substantially orthogonal to the main scanning direction (Y direction), by using a conveyance roller that is rotationally driven by a sub-scanning motor 118 (see FIG. 3), thereby relatively moving with respect to the liquid ejection head 122. However, the main scanning direction (Y direction) and the sub-scanning direction (X direction) do not necessarily have to be substantially orthogonal, and it is sufficient if they intersect.

[0021] The heads 122a, 122b, 122c arrange nozzle rows composed of a plurality of nozzles (not shown) in the sub-scanning direction (X direction). The heads 122a, 122b, 122c are mounted with the ink droplet ejection direction from the nozzles facing downward (Z direction: see FIG. 15). The heads 122a, 122b, 122c are respectively installed so as to overlap in the sub-scanning direction (X direction). The carriage 121 mounts a sub-tank to supply ink of various colors corresponding to the heads 122a, 122b, 122c.

[0022] The "liquid ejection head" is a functional component that ejects and sprays liquid from nozzles. The liquid to be ejected may be any liquid having a viscosity and surface tension that can be ejected from the liquid ejection head 122, and is not particularly limited, but preferably has a viscosity of 30 mPa·s or less at normal temperature and pressure, or by heating or cooling. More specifically, it includes solutions, suspensions, emulsions, etc. containing solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functional imparting materials such as surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium, edible materials such as natural pigments, etc. These can be used, for example, in applications such as inkjet inks, surface treatment liquids, components of electronic elements and light-emitting elements, liquids for forming electronic circuit resist patterns, and material liquids for three-dimensional modeling.

[0023] As the energy generation source for ejecting the liquid of the "liquid ejection head", those using pressure generating means such as piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements) are included.

[0024] Also, the pressure generating means used in the "liquid ejection head" is not limited. For example, in addition to the piezoelectric actuators (such as those using laminated piezoelectric elements) as described above, thermal actuators using electrothermal conversion elements such as heating resistors, electrostatic actuators composed of diaphragms and counter electrodes, etc. may also be used.

[0025] The image forming apparatus 100 includes a cartridge loading unit 1 for detachably mounting ink cartridges 10y, 10c, 10m, 10k of each color (referred to as "ink cartridge 10" when not distinguished).

[0026] The ink in the ink cartridge 10 is replenished and supplied to the sub-tank of the carriage 121 through the supply tubes 36 of each color by the supply pump unit. The supply pump unit and the supply tubes 36 constitute a supply mechanism. Note that the ink cartridge 10 may include a white ink cartridge.

[0027] The image forming apparatus 100 includes a maintenance and recovery mechanism 81 in a non-printing area on one side in the main scanning direction (Y direction) of the carriage 121. The maintenance and recovery mechanism 81 maintains and / or recovers the state of the nozzles of the liquid ejection head 122.

[0028] The maintenance and recovery mechanism 81 includes cap members 82a, 82b, 82c (referred to as "cap member 82" when not distinguished) for capping each nozzle surface of the liquid ejection head 122, a wiping unit 83 for wiping the nozzle surface, and the like. Further, a replaceable waste liquid tank for storing waste liquid generated by the maintenance and recovery operation is provided below the maintenance and recovery mechanism 81 of the liquid ejection head 122.

[0029] The "liquid ejection unit" is an integrated unit of functional components and mechanisms with the liquid ejection head 122, and is an aggregate of components related to liquid ejection. For example, the "liquid ejection unit" includes at least one of a head tank (sub-tank of the carriage 121), the carriage 121, a supply mechanism, the maintenance and recovery mechanism 81, and a configuration of a main scanning movement mechanism combined with the liquid ejection head 122.

[0030] Here, the integration means, for example, that the liquid ejection head 122 and functional components and mechanisms are fixed to each other by fastening, adhesion, engagement, etc., and those in which one is movably held with respect to the other. Further, the liquid ejection head 122 and functional components and mechanisms may be configured to be detachable from each other.

[0031] For example, as a liquid ejection unit, there is one in which the liquid ejection head 122 and the head tank are integrated. Also, there is one in which the liquid ejection head 122 and the head tank are integrated by being connected to each other with a tube or the like. Here, a unit including a filter can also be added between the head tank of these liquid ejection units and the liquid ejection head 122.

[0032] Further, as a liquid ejection unit, there is one in which the liquid ejection head 122 and the carriage 121 are integrated.

[0033] In addition, as a liquid ejection unit, there is one in which a liquid ejection head 122 is movably held on a main guide rod 31 that is a guide member constituting a part of a main scanning movement mechanism, and the liquid ejection head 122 and the main scanning movement mechanism are integrated. Also, there is one in which the liquid ejection head 122, the carriage 121, and the main scanning movement mechanism are integrated.

[0034] In addition, as a liquid ejection unit, there is one in which a cap member 82 that is a part of a maintenance and recovery mechanism 81 is fixed to a carriage 121 to which a liquid ejection head 122 is attached, and the liquid ejection head 122, the carriage 121, and the maintenance and recovery mechanism 81 are integrated.

[0035] In addition, as a liquid ejection unit, there is one in which a supply tube 36 is connected to a liquid ejection head 122 to which a head tank (sub-tank of the carriage 121) or a flow path component is attached, and the liquid ejection head 122 and the supply mechanism are integrated. Through this tube, the liquid from the liquid storage source is supplied to the liquid ejection head 122.

[0036] The main scanning movement mechanism shall include the main guide rod 31 alone which is a guide member. Also, the supply mechanism shall include the supply tube 36 alone and the cartridge loading unit 1 alone.

[0037] FIG. 3 is a block diagram showing an example of the hardware configuration of the image forming apparatus 100. As shown in FIG. 3, the image forming apparatus 100 includes a control unit 101, an operation panel 114, an environment sensor 115, an optical sensor 37, a head driver 116, a main scanning motor 117, a sub-scanning motor 118, a fan 119, a heater 120, a liquid ejection head 122, and a movement mechanism 140.

[0038] As shown in FIG. 3, the control unit 101 includes a CPU (Central Processing Unit) 102, a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, a non-volatile memory (NVRAM: Non-Volatile RAM) 105, an ASIC (Application Specific Integrated Circuit) 106, an I / F 107, a print control unit 108, a main scanning motor drive unit 109, a sub-scanning motor drive unit 110, a fan control unit 111, a heater control unit 112, and an I / O 113. Note that the control unit 101 may include configurations other than those described above.

[0039] The CPU 102, ROM 103, RAM 104, non-volatile memory 105, ASIC 106, I / F 107, print control unit 108, main scanning motor drive unit 109, sub-scanning motor drive unit 110, fan control unit 111, heater control unit 112, and I / O 113 are connected to be mutually communicable via, for example, a bus or the like.

[0040] The CPU 102 controls the operation of the entire image forming apparatus 100. Specifically, the CPU 102 realizes various functions by executing programs stored in the ROM 103 and the like.

[0041] The ROM 103 stores programs executed by the CPU 102 and other fixed data. The RAM 104 temporarily stores image data and the like. The non-volatile memory 105 holds data even while the power of the image forming apparatus 100 is turned off. The ASIC 106 is a circuit for performing various signal processes and rearrangement, such as image processing, and for processing input / output signals for controlling the entire apparatus.

[0042] I / F 107 is an interface circuit that transmits and receives data and signals to and from the host side. Specifically, I / F 107 receives print data (image data), etc. generated by a printer driver of a host such as an information processing device, an image reading device, or an imaging device via a cable, a network, or the like. That is, the generation and output of print data to the control unit 101 may be performed by the printer driver on the host side.

[0043] The print control unit 108 is a circuit that generates a drive waveform for driving the liquid ejection head 122 and selectively drives pressure generating means that generates pressure for the liquid ejection head 122 to eject liquid (ink) from the nozzles, and outputs print data and various associated data to the head driver 116.

[0044] The main scanning motor drive unit 109 is a circuit for driving the main scanning motor 117. The sub-scanning motor drive unit 110 is a circuit for driving the sub-scanning motor 118. The fan control unit 111 is a circuit for controlling the output of the fan 119 so that blowing at a predetermined temperature and air volume is performed.

[0045] The heater control unit 112 is a circuit for controlling the heater 120 so as to reach a set temperature. I / O 113 is a circuit for acquiring information from the environment sensor 115 and extracting information required for controlling each part of the image forming apparatus 100. Note that I / O 113 also inputs detection signals from various sensors (for example, the optical sensor 37) other than the environment sensor 115.

[0046] The operation panel 114 is a device for inputting and displaying various information such as user-specified resolution. The operation panel 114 is communicably connected to the CPU 102, etc. via, for example, the bus of the control unit 101.

[0047] The environment sensor 115 is a sensor that detects, for example, the ambient temperature, the ambient humidity, etc. The environment sensor 115 is connected to I / O 113 of the control unit 101.

[0048] The head driver 116 is a circuit for driving the liquid ejection head 122 by selectively applying drive pulses that constitute a drive waveform given from the print control unit 108 to the pressure generating means of the liquid ejection head 122 based on input image data (e.g., dot pattern data). The head driver 116 is connected to the print control unit 108 of the control unit 101. Note that the control of the ejection amount is performed, for example, by controlling the amplitude of the drive waveform input to the pressure generating means of the liquid ejection head 122, but the ejection amount may be controlled using other means.

[0049] The main scanning motor 117 is a device that rotationally drives a timing belt by driving and moves the carriage 121 provided with the liquid ejection head 122 in the main scanning direction (the direction of arrow Y). The main scanning motor 117 is connected to the main scanning motor drive unit 109 of the control unit 101.

[0050] The sub-scanning motor 118 is a device that drives and operates a conveyance roller that conveys the medium 40, which is an object to be ejected with liquid (ink) by the liquid ejection head 122, in the sub-scanning direction (X direction). The sub-scanning motor 118 is connected to the sub-scanning motor drive unit 110 of the control unit 101.

[0051] The movement mechanism 140 relatively moves the liquid ejection head 122 and the medium 40. The movement mechanism 140 includes a main guide rod 31, a sub sheet metal guide 32, a carriage 121, conveyance rollers, etc., and constitutes a main scanning movement mechanism.

[0052] The movement mechanism 140 relatively moves the liquid ejection head 122 and the medium 40 along the main scanning direction (Y direction) by the main guide rod 31, the sub sheet metal guide 32, the carriage 121, etc. Also, the movement mechanism 140 relatively moves the liquid ejection head 122 and the medium 40 along the sub-scanning direction (X direction) by conveyance rollers that convey the medium 40, etc. In the present embodiment, the relative movement in the sub-scanning direction (X direction) by the movement mechanism 140 is an intermittent movement. The intermittent movement means a movement that alternately performs movement and stop.

[0053] The fan 119 is a device for promoting the convection of air inside the image forming apparatus 100 by driving and preventing the temperature from rising excessively due to the stagnation of the warmed air at the upper part of the image forming apparatus 100. The fan 119 is connected to the fan control unit 111 of the control unit 101.

[0054] FIG. 4 is a block diagram showing an example of the functional configuration of the control unit 101. Note that the description of the components overlapping with those in FIG. 3 is omitted.

[0055] As shown in FIG. 4, the control unit 101 includes a color separation data generation unit 211 and a discharge control unit 212. The discharge control unit 212 generally controls the discharge of ink.

[0056] When the image data to be printed is input, the color separation data generation unit 211 generates color separation data for each color of ink mounted in the image forming apparatus 100 from the input image data (an example of the input image). For example, when the image forming apparatus 100 performs printing using CMYK inks, the color separation data generation unit 211 generates color separation data for each of the CMYK colors from the input image data.

[0057] The discharge control unit 212 applies a dot data generation mask to the color separation data for each color generated by the color separation data generation unit 211 to generate print dot data. Here, the dot data generation mask is, for example, a mask pattern for forming an image by mixing print dots with two liquid discharge heads in the nozzle overlap region at the ends of the adjacent heads 122a, 122b, 122c.

[0058] The control unit 101 realizes these functions (the color separation data generation unit 211 and the discharge control unit 212) by the CPU 102 executing a predetermined program. Further, the control unit 101 may realize some or all of these functions by one or a plurality of processing circuits.

[0059] The "processing circuit" includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, an ASIC (Application Specific Integrated Circuit) designed to execute each function described above, a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and devices such as conventional circuit modules.

[0060] The control unit 101 controls the liquid ejection head 122 and the moving mechanism 140 so as to place the ink on the medium 40 while relatively moving the liquid ejection head 122 and the medium 40 a plurality of times. The ink placed on the medium 40 forms dots in the image by fixing on the medium 40. More specifically, after one ink droplet formed by the ink ejected from the liquid ejection head 122 lands on the medium 40, it dries and fixes on the medium 40 to form one dot in the image. The image is formed as an aggregate of a plurality of dots.

[0061] Here, the conventional problems will be described.

[0062] FIG. 5 is a diagram showing an example of a conventional mask pattern when the end nozzles of two heads 201a and 201b arranged in the X direction are overlapped and arranged, FIG. 6 is a diagram showing the characteristics of the driving frequency of the conventional ejection droplet volume, FIG. 7 is a diagram showing the characteristics of the driving frequency and the conventional mask pattern, and FIG. 8 is a diagram showing the Y deviation and the conventional mask pattern. In FIG. 5, the number of nozzles in the nozzle overlap region 202 where the nozzles of both the head 201a and the head 201b are overlapped and arranged is set to 12 nozzles, but it may be more or less than this.

[0063] The landing dot A shown in FIG. 5 shows the state of the printed dot when the droplets ejected from the heads 201a and 201b land at ideal positions on the recording medium 203. The landing dot A includes a normal part A1, a normal part A2, and a mask part A3 corresponding to the nozzle overlap region 202.

[0064] As shown in FIG. 5, the normal part A1 of the landing dot A is formed by the ejected droplets from the head 201a, and the normal part A2 is formed by the ejected droplets from the head 201b.

[0065] As shown in FIG. 5, the mask part A3 of the landing dot A is formed by the ejected droplets from the nozzles in the nozzle overlap region 202 of the heads 201a and 201b. The mask part A3 of the landing dot A shown in FIG. 5 shows an example in which an XY equal mask process is performed in which the printed dots formed by the heads 201a and 201b are alternately arranged in both the X direction and the Y direction. By this XY equal mask process, the mask part A3 forms an image by mixing the printed dots of the two heads 201a and 201b, thereby suppressing image quality degradation such as density unevenness and streaks due to variations in ejection characteristics between the heads 201a and 201b and landing deviation due to air flow at the end of the liquid ejection head.

[0066] Incidentally, as shown in FIG. 6, generally, the ejected droplet amount of the liquid ejection head varies due to differences in the residual vibration of the pressure wave remaining after ejection according to the drive frequency of the drive waveform. FIG. 6 shows an example in which what was "droplet amount 1" at the drive frequency F decreases to "droplet amount 2" when the drive frequency becomes (1 / 2)F.

[0067] More specifically, as shown in FIG. 7(a), when an XY equal mask process is performed in the nozzle overlap region 202 of the two heads 201a and 201b to distribute the printed dots, the ejection intervals in the mask part A3 for a single head will be different from the ejection intervals in the normal parts A1 and A2. As a result, as shown in FIG. 7(b), in the mask part A3 of the landing dot A corresponding to the nozzle overlap region 202, the drive frequency per nozzle decreases to (1 / 2)F compared to the drive frequency F of the normal parts A1 and A2. Therefore, the normal parts A1 and A2 will be formed by printed dots of "droplet amount 1", and the mask part A3 will be formed by printed dots of "droplet amount 2", and the mask part A3 will become thinner than the normal parts A1 and A2, resulting in the occurrence of white unevenness.

[0068] Also, as shown in FIG. 8, if the landing position of the printed dots of one of the heads is shifted relatively due to the displacement in the Y direction (ΔY) between the two heads 201a and 201b or the difference in the droplet velocity between the two heads 201a and 201b, the printed dots of the head 201a and the head 201b will land overlapping each other, and it will become impossible to obtain the same density as that of the normal portions A1 and A2 in the mask portion A3. This also had the problem of being visually recognized as density unevenness or streaks.

[0069] Therefore, in the present embodiment, in the nozzle overlap region 300 (see FIG. 9) at the ends of two adjacent heads, a mask pattern that reduces the occurrence of density unevenness and streaks caused by the difference in the drive frequency characteristics of the ejection droplet amounts between the heads, or the displacement between the heads or the difference in the droplet velocity, is used to equalize the image quality of the nozzle overlap region 300 at the ends of the heads.

[0070] Here, FIG. 9 is a diagram showing an example of a mask pattern according to the first embodiment. Here, the nozzle overlap region 300 of the two heads 122a and 122b will be described as an example.

[0071] As shown in FIG. 9, the mask portion A3 of the landing dot A is formed by the ejected droplets from the nozzles in the nozzle overlap region 300 of the heads 122a and 122b. Here, the length of the mask portion A3 in the X direction is 12 pixels. On the other hand, since the nozzle overlap region 300 can be imaged with a total of 24 nozzles, which are 12 nozzles of the head 122a and 12 nozzles of the head 122b, there are twice as many nozzles as those in the normal portions A1 and A2.

[0072] As shown in FIG. 9, the ejection control unit 212 of the control unit 101 overlaps the nozzle 1a (in use) of the head 122a and the nozzle 2b (not in use) of the head 122b, and overlaps the nozzle 1b (not in use) of the head 122a and the nozzle 2a (in use) of the head 122b in the nozzle overlap region 300.

[0073] By doing so, as shown in FIG. 9, in the mask process of the nozzle overlap region 300, the discharge control unit 212 of the control unit 101 arranges the printed dots formed by the head 122b formed by the head 122a in the X direction, but in the Y direction, it is a vertical stripe mask pattern that makes the printed dots formed by the same heads 122a and 122b continuous.

[0074] In addition, the discharge control unit 212 of the control unit 101 sets the number of dots discharged from the same head that are continuous in a direction intersecting the column direction of the nozzle array, that is, the number of consecutive nozzles to be "used" and the number of consecutive nozzles to be "not used", to 2 dots or less.

[0075] In the example shown in FIG. 9(a), since the discharge interval in the mask portion A3 for a single head is the same as the discharge intervals in the normal portions A1 and A2, the printed dots in the normal portions A1 and A2 and the mask portion A3 have the same driving frequency. For this reason, since it is not affected by the characteristics of the driving frequency as shown in FIG. 6, there is no difference in the droplet volume due to the difference in the characteristics of the driving frequency as shown in FIG. 7, and the dot sizes of the printed dots in the normal portions A1 and A2 and the mask portion A3 can be made the same.

[0076] Also, as shown in FIG. 9(b), even if a positional deviation (Y deviation) ΔY in the Y direction occurs between the two heads 122a and 122b, since it is a vertical stripe mask pattern that makes the printed dots formed by the same heads 122a and 122b continuous in the Y direction, the printed dots do not overlap as shown in FIG. 8. Therefore, according to the mask pattern according to the present embodiment, it is possible to suppress the occurrence of image quality degradation such as density unevenness and streaks in the nozzle overlap region 300 between the adjacent heads 122a and 122b compared to the conventional mask pattern.

[0077] Between the heads 122a and 122b, due to the head structure and temperature influence, they are not exactly the same. Therefore, in the nozzle overlap region 300, by not hardening the area ejected from one side head, it is possible to suppress density unevenness and streaks caused by the difference in dot diameter between the heads 122a and 122b.

[0078] As described above, according to the present embodiment, the mask pattern in the nozzle overlap region 300 at the head end of the adjacent heads 122a and 122b arranges the printed dots formed by the head 122a and the printed dots formed by the head 122b with respect to the X direction, but is composed only of the printed dots formed by the same head with respect to the Y direction, and the continuous number of nozzles to be "used" and nozzles to be "not used" is set to 2 dots or less. Thereby, in the nozzle overlap region 300 at the head end of the two adjacent heads 122a and 122b, it is possible to suppress the occurrence of density unevenness and streaks due to the difference in the driving frequency characteristics of the ejection droplet amount between the two heads 122a and 122b, or the positional deviation or droplet speed difference between the two heads 122a and 122b, and it is possible to equalize the image quality of the nozzle overlap region 300 at the head end of the adjacent heads 122a and 122b.

[0079] Further, according to the present embodiment, even if a positional deviation (Y deviation) ΔY in the Y direction occurs between the two heads 122a and 122b, it is possible to suppress the occurrence of image quality degradation such as density unevenness and streaks in the nozzle overlap region 300 between the adjacent heads 122a and 122b.

[0080] The program executed in the image forming apparatus 100 of the present embodiment is provided by being recorded on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a DVD (Digital Versatile Disc) in an installable format or an executable format file.

[0081] Alternatively, the program executed by the image forming apparatus 100 of the present embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Further, the program executed by the image forming apparatus 100 of the present embodiment may be configured to be provided or distributed via a network such as the Internet.

[0082] Alternatively, the program executed by the image forming apparatus 100 of the present embodiment may be configured to be provided by being pre - incorporated into a ROM or the like.

[0083] The program executed by the image forming apparatus 100 of the present embodiment has a module configuration including the above - described respective parts (color separation data generation unit 211, ejection control unit 212). As actual hardware, the CPU (processor) reads the program from the storage medium and executes it, whereby the above - described respective parts are loaded onto the main storage device, and the color separation data generation unit 211 and the ejection control unit 212 are generated on the main storage device.

[0084] In the present embodiment, the heads 122a and 122b having two - row nozzle arrays have been described, but the present invention is not limited thereto, and a liquid ejection head having an eight - row nozzle array as shown in FIG. 10 or a liquid ejection head having another column configuration may be used.

[0085] In the present embodiment, the multi - pass method in which the carriage 121 reciprocates and ink is ejected has been described, but the present invention is not limited thereto, and it is also applicable to the line head method in which the liquid ejection head is fixed and the medium is moved. In the case of the line head method, a mask pattern that does not use the nozzles on the most upstream side, which are easily affected by the airflow in the conveyance direction of the medium (the direction intersecting the column direction of the nozzle array), may be used. In particular, since an inkjet printer using the line head method has a high conveyance speed, the drive frequency becomes high and the influence of the frequency characteristics becomes large, so a great effect can be obtained.

[0086] (Second Embodiment) Next, a second embodiment will be described. In the following description of the second embodiment, the description of the same parts as those in the first embodiment will be omitted, and the parts different from the form of the first embodiment will be described.

[0087] <Electrode manufacturing apparatus> The "apparatus for discharging a liquid" according to the present invention also includes an apparatus for manufacturing an electrode and an electrochemical element. Hereinafter, the electrode manufacturing apparatus will be described.

[0088] FIG. 11 is a schematic diagram showing an example of an electrode manufacturing apparatus according to the second embodiment. The electrode manufacturing apparatus is an apparatus for manufacturing an electrode including a layer having an electrode material by discharging a liquid composition using a head module including the liquid discharge head 122 described in the first embodiment.

[0089] <Forming means for a layer containing an electrode material, forming step for a layer containing an electrode material> The discharging means included in the electrode manufacturing apparatus shown in FIG. 11 is the head module according to the above-described embodiment of the present invention. By discharging the liquid composition from the discharge head included in the head module, the liquid composition is applied onto the object, and a liquid composition layer is formed. The object (hereinafter, may be referred to as "discharge object") is not particularly limited as long as it is an object on which a layer containing an electrode material is formed, and can be appropriately selected according to the purpose. For example, examples of the object include an electrode substrate (current collector), an active material layer, and a layer containing a solid electrode material. Further, the object may be an electrode composite layer containing an active material on an electrode substrate (current collector). Further, the discharging means and the discharging step may be means and steps for forming a layer having an electrode material by directly discharging the liquid composition as long as it is possible to form a layer having an electrode material on the discharge object. Further, the discharging means and the discharging step may be means and steps for forming a layer having an electrode material by indirectly discharging the liquid composition.

[0090] <Other configurations, other steps> As for other components included in the manufacturing apparatus of the electrode composite material layer, there are no particular limitations as long as the effects of the present invention are not impaired, and they can be appropriately selected according to the purpose. Similarly, other steps included in the manufacturing method of the electrode composite material layer are not particularly limited as long as the effects of the present invention are not impaired, and they can be appropriately selected according to the purpose. For example, as components and steps included in the manufacturing apparatus and manufacturing method of the electrode composite material layer, heating means and a heating step can be mentioned.

[0091] <Heating means, heating step> The heating means included in the manufacturing apparatus of the electrode composite material layer is means for heating the liquid composition discharged by the discharging means. Also, the heating step included in the manufacturing method of the electrode composite material layer is a step of heating the liquid composition discharged in the discharging step. By heating the liquid composition, the liquid composition layer can be dried.

[0092] <Configuration for forming a layer containing an electrode material by directly discharging a liquid composition> Here, as an example of the manufacturing apparatus of the electrode, a manufacturing apparatus of an electrode for forming an electrode composite material layer containing an active material on an electrode substrate (current collector) will be described. As shown in FIG. 11, the manufacturing apparatus of the electrode includes a discharging engineering section 150 including a step of applying a liquid composition onto a printing substrate 704 having an object to be discharged to form a liquid composition layer, and a heating engineering section 130 including a heating step of heating the liquid composition layer to obtain an electrode composite material layer.

[0093] The manufacturing apparatus of the electrode includes a conveying section 705 for conveying the printing substrate 704. The conveying section 705 conveys the printing substrate 704 at a preset speed in the order of the discharging engineering section 150 and the heating engineering section 130. As for the manufacturing method of the printing substrate 704 having an object to be discharged such as an active material layer, there are no particular limitations, and known methods can be appropriately selected. The discharging engineering section 150 includes a liquid discharging head 122 for realizing an application step of applying a liquid composition onto the printing substrate 704, a storage container 281b for storing the liquid composition 707, and a supply tube 281c for supplying the liquid composition 707 stored in the storage container 281b to the liquid discharging head 122.

[0094] In the ejection engineering department 150, the liquid composition 707 is ejected from the liquid ejection head 122, and the liquid composition 707 is applied onto the printing substrate 704, whereby a liquid composition layer is formed in a thin film shape. Note that the storage container 281b may be configured to be integrated with the manufacturing apparatus for the electrode composite layer, or may be configured to be removable from the manufacturing apparatus for the electrode composite layer. Further, the storage container 281b may be a container used for adding to a storage container integrated with the manufacturing apparatus for the electrode composite layer or a storage container removable from the manufacturing apparatus for the electrode composite layer.

[0095] The storage container 281b and the supply tube 281c can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0096] In the heating engineering department 130, a solvent removal process is performed to heat and remove the solvent remaining in the liquid composition layer. Specifically, the solvent remaining in the liquid composition layer is heated and dried by the heating device 703 in the heating engineering department 130, whereby the solvent is removed from the liquid composition layer. Thereby, the electrode composite layer is formed. Further, the solvent removal process in the heating engineering department 130 may be performed under reduced pressure.

[0097] There is no particular limitation on the heating device 703, and it can be appropriately selected according to the purpose. For example, examples of the heating device 703 include substrate heating, an IR heater, and a hot air heater. Further, the heating device 703 may be a combination of at least two of substrate heating, an IR heater, and a hot air heater. Further, regarding the heating temperature and the heating time, they can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the formed film thickness.

[0098] By using the manufacturing apparatus for the electrode according to the embodiment of the present invention, the liquid composition can be ejected to the targeted position of the ejection object. The electrode composite layer can be suitably used, for example, as a part of the configuration of an electrochemical element. There is no particular limitation on the configuration other than the electrode composite layer in the electrochemical element, and known ones can be appropriately selected. For example, examples of the configuration other than the electrode composite layer include a positive electrode, a negative electrode, and a separator.

[0099] In the present application, the "device for discharging a liquid" includes a liquid discharge head 122 or a liquid discharge unit, and is a device that drives the liquid discharge head 122 to discharge a liquid. The device for discharging a liquid includes not only a device capable of discharging a liquid onto an object to which the liquid can adhere, but also a device capable of discharging a liquid into the air or into a liquid.

[0100] This "device for discharging a liquid" can also include means related to the feeding, conveying, and paper discharging of an object to which a liquid can adhere, as well as other pretreatment devices, post-treatment devices, and the like.

[0101] For example, as the "device for discharging a liquid", there are an image forming device that discharges ink to form an image on a sheet of paper, and a three-dimensional modeling device (three-dimensional shaping device) that discharges a shaping liquid onto a powder layer formed by layering powders in order to model a three-dimensional object (three-dimensional shaped object).

[0102] In addition, the "device for discharging a liquid" is not limited to those in which a significant image such as characters or figures is visualized by the discharged liquid. For example, those that form a pattern or the like having no meaning by itself, and those that model a three-dimensional image are also included.

[0103] The above-mentioned "object to which a liquid can adhere" means an object to which a liquid can adhere at least temporarily, and includes an object to which the liquid adheres and adheres firmly, an object to which the liquid adheres and penetrates, and the like. Specific examples include recording media such as paper, recording paper, recording sheets, films, and cloth, electronic components such as electronic substrates and piezoelectric elements, powder layers (powder layers), organ models, media such as test cells, and include all objects to which a liquid adheres unless otherwise particularly limited.

[0104] The material of the above-mentioned "object to which a liquid can adhere" may be paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc., as long as a liquid can adhere even temporarily.

[0105] In addition, the "liquid" may be any liquid that can be ejected from the liquid ejection head 122, and is not particularly limited, but it is preferably a liquid that has a viscosity of 30 mPa·s or less at normal temperature and pressure, or by heating or cooling. More specifically, it includes solvents such as water and organic solvents, colorants such as dyes and pigments, polymerizable compounds, resins, functional additive materials such as surfactants, biocompatible materials such as DNA, amino acids, proteins, and calcium, edible materials such as natural pigments, etc., and solutions, suspensions, emulsions, etc. containing these can be used, for example, in applications such as inkjet inks, surface treatment liquids, components of electronic devices and light-emitting devices, liquids for forming electronic circuit resist patterns, and material liquids for three-dimensional modeling.

[0106] In addition, as the "device for ejecting a liquid", there is a device in which the liquid ejection head 122 and a member to which the liquid can adhere move relative to each other, but it is not limited thereto. Specific examples include serial type devices that move the liquid ejection head 122 and line type devices that do not move the liquid ejection head 122.

[0107] In addition, other examples of the "device for ejecting a liquid" include a treatment liquid coating device that ejects a treatment liquid onto paper in order to modify the surface of the paper for purposes such as surface modification of the paper, and an injection granulation device that injects a composition liquid in which raw materials are dispersed in a solution through nozzles to granulate fine particles of the raw materials.

Explanation of Reference Numerals

[0108] 100 Device for ejecting a liquid 101 Control unit 122 Liquid ejection head 122a, 122b, 122c Heads 212 Ejection control unit 300 Nozzle overlap region

Prior Art Documents

Patent Documents

[0109]

Patent Document 1

Claims

1. A liquid ejection head having a plurality of heads arranged with a nozzle array composed of a plurality of nozzles and selectively ejecting droplets from the nozzles, wherein adjacent heads are installed with a nozzle overlap region provided at an end in the column direction of the nozzle array, for the mask pattern of the nozzle overlap region, data in a direction parallel to the column direction of the nozzle array is composed of both pixel data by one of the plurality of heads and pixel data by another of the plurality of heads, and data in a direction intersecting the column direction of the nozzle array is composed of either pixel data by the one head or pixel data by the other head, and includes a discharge control unit, the discharge control unit makes the number of dots ejected from the same head and continuous in a direction intersecting the column direction of the nozzle array be equal to or less than a predetermined number of dots, A liquid ejection head characterized by this.

2. The discharge control unit makes the number of dots ejected from the same head and continuous in a direction intersecting the column direction of the nozzle array be equal to or less than 2 dots. The liquid ejection head according to Claim 1, characterized by this.

3. The liquid ejection head according to Claim 1 or 2, and at least one of a head tank, a carriage, a supply mechanism, a maintenance and recovery mechanism, and a main scanning movement mechanism, A liquid ejection unit characterized by including this.

4. The liquid ejection head according to Claim 1 or 2, and a control unit for driving the liquid ejection head to eject liquid, An apparatus for ejecting liquid characterized by including this.

5. A liquid ejection method in a liquid ejection head having a plurality of heads arranged with a nozzle array composed of a plurality of nozzles and selectively ejecting droplets from the nozzles, wherein adjacent heads are installed with a nozzle overlap region provided at an end in the column direction of the nozzle array, for the mask pattern of the nozzle overlap region, data in a direction parallel to the column direction of the nozzle array is composed of both pixel data by one of the plurality of heads and pixel data by another of the plurality of heads, and data in a direction intersecting the column direction of the nozzle array is composed of either pixel data by the one head or pixel data by the other head, and includes a discharge control step. The ejection control step sets the number of dots continuously ejected from the same head in a direction intersecting the column direction of the nozzle array to be equal to or less than a predetermined number of dots. A liquid ejection method characterized by this. **Claim 6** A computer that controls a liquid ejection head having a plurality of heads that array nozzle arrays composed of a plurality of nozzles and selectively eject droplets from the nozzles, and that installs adjacent heads with a nozzle overlap region provided at an end in the column direction of the nozzle array. For the mask pattern of the nozzle overlap region, the data in the direction parallel to the column direction of the nozzle array is composed of both the pixel data by one of the plurality of heads and the pixel data by the other of the plurality of heads, and the data in the direction intersecting the column direction of the nozzle array is made to function as an ejection control unit that is composed of either the pixel data by the one head or the pixel data by the other head. The ejection control unit sets the number of dots continuously ejected from the same head in a direction intersecting the column direction of the nozzle array to be equal to or less than a predetermined number of dots. A program characterized by this.

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