Liquid discharge head, unit, device, method and computer program product

Abstract

The invention relates to a liquid discharge head, a liquid discharge unit, a liquid discharge apparatus, a liquid discharge method, and a computer program product. The purpose of the present invention is to make image quality uniform in a nozzle overlapping region of end portions of adjacent liquid discharge heads. The liquid discharge head includes a plurality of discharge heads in which a nozzle row formed of a plurality of nozzles is arranged and liquid droplets are selectively discharged from the nozzles, and adjacent discharge heads of the liquid discharge heads are provided with a nozzle overlap region at an end portion in a row direction of the nozzle row, and are provided with a discharge control portion. In the mask pattern of the nozzle overlap region, data in a direction parallel to the column direction of the nozzle column is configured by both pixel data of one of the plurality of discharge heads and pixel data of the other discharge head, and data in a direction intersecting the column direction of the nozzle column is configured by pixel data of any one discharge head. The discharge control unit causes the number of points discharged from the same discharge head to be equal to or less than a predetermined point number in a direction intersecting the row direction of the nozzle row.

Description

Technical Field

[0001] The present invention relates to a liquid discharge head, a liquid discharge unit, a liquid discharge device, a liquid discharge method, and a computer program product. Background Art

[0002] The prior art discloses some image processing for a nozzle overlapping region at an end portion of adjacent liquid discharge heads.

[0003] Patent Document 1 discloses a technical solution, which suppresses a deterioration in image quality in a nozzle overlapping region of a liquid discharge head by forming a mask in the nozzle overlapping region and forming an image by mixing print dots with two liquid discharge heads.

[0004] Patent Document 2 discloses another technical solution, in which a dot column in the Y direction in the nozzle overlapping region is formed by a head end portion of one liquid discharge head and a head end portion of another liquid discharge head together. Thus, compared with a mechanism using only a head end portion of one liquid discharge head, a change in density in the nozzle overlapping region can be suppressed.

[0005] Patent Document 1: Japanese Patent Gazette No. 3702711

[0006] Patent Document 2: Japanese Patent Application Laid-Open Gazette No. 2009-160876

[0007] However, as in the prior art, if print dots are distributed in a nozzle overlapping region of two liquid discharge heads, the driving frequency of each nozzle in the nozzle overlapping region is lower than that in a normal nozzle region outside the nozzle overlapping region. Generally, the amount of liquid droplets discharged by a liquid discharge head mostly varies with the driving frequency, resulting in a change in the size of print dots formed on the nozzle overlapping region where a mask is formed. Thus, there is a portion where the size of printed dots changes in the nozzle overlapping region, and thus there are problems of density unevenness or stripes.

[0008] Ideally, print dots discharged by two liquid discharge heads in a nozzle overlapping region where a mask is formed fall on ideal positions. However, due to a positional deviation and a difference in droplet discharge speed between the two liquid discharge heads, if the droplet falling position of print dots of one liquid discharge head deviates relatively, a density same as that in a normal nozzle region cannot be obtained. Thus, there will also occur problems of density unevenness or stripes in a portion where a density same as that in a normal nozzle region cannot be obtained.

[0009] In addition, recently, in a liquid discharge head by adopting a semiconductor process or the like, a manufacturing deviation between liquid discharge heads has become very small, and a deviation in frequency characteristics is much larger than a deviation between liquid discharge heads. Therefore, a mask for eliminating the influence of frequency characteristics is effective. Summary of the Invention

[0010] The present invention is a technical solution proposed in view of the above problems, and its object is to make the image quality in the nozzle overlapping region of adjacent liquid ejection head ends uniform.

[0011] In order to solve the above problems and achieve the object of the present invention, the present invention provides a liquid ejection head having a plurality of ejection heads in which nozzle rows composed of a plurality of nozzles are arranged, and droplets are selectively ejected from the nozzles. In the liquid ejection head, adjacent ejection heads are provided with a nozzle overlapping region at the end in the column direction of the nozzle row. The liquid ejection head is characterized by including an ejection control unit that forms data in a direction parallel to the column direction of the nozzle row in the mask pattern of the nozzle overlapping region by using pixel data of one of the plurality of ejection heads and pixel data of another of the plurality of ejection heads, and forms data in a direction intersecting the column direction of the nozzle row by using pixel data of any one of the pixel data of the one ejection head and the pixel data of the other ejection head. The ejection control unit makes the number of consecutive points ejected from the same ejection head in a direction intersecting the column direction of the nozzle row be equal to or less than a specified number of points.

[0012] The effect of the present invention is that it can make the image quality in the nozzle overlapping region of the ends of adjacent liquid ejection heads uniform. Description of the Drawings

[0013] Figure 1 is an internal perspective three-dimensional view of an image forming apparatus according to a first embodiment.

[0014] Figure 2 is a schematic diagram of the configuration of an image forming apparatus.

[0015] Figure 3 is a block diagram of an example of the hardware configuration of an image forming apparatus.

[0016] Figure 4 is a block diagram of an example of the functional configuration of a control unit.

[0017] Figure 5 is a schematic diagram of an example of a past mask pattern when the end nozzles of two ejection heads arranged in the X direction are overlapped and arranged.

[0018] Figure 6 is a graph of the drive frequency characteristics of the past droplet ejection amount.

[0019] Figure 7 is a schematic diagram of the drive frequency characteristics and a past mask pattern.

[0020] Figure 8 is a schematic diagram of Y deviation and a past mask pattern.

[0021] Figure 9It is a schematic diagram of a mask pattern related to the first embodiment.

[0022] Figure 10 It is a schematic diagram of another example of a mask pattern.

[0023] Figure 11 It is a schematic diagram of an electrode manufacturing apparatus related to the second embodiment.

[0024] Symbol Explanation

[0025] 100 Liquid discharge device

[0026] 101 Control unit

[0027] 122 Liquid discharge head

[0028] 122a, 122b, 122c Discharge heads

[0029] 212 Discharge control unit

[0030] 300 Nozzle overlapping area Detailed Embodiment

[0031] Hereinafter, embodiments of a liquid discharge head, a liquid discharge unit, a liquid discharge device, a liquid discharge method, and a computer program product will be described in detail with reference to the accompanying drawings.

[0032] Hereinafter, an image forming apparatus will be described as an example of a liquid ejection apparatus to which the present invention is applicable, but the present invention is not limited thereto.

[0033] <First Embodiment>

[0034] Figure 1 It is an internal perspective three-dimensional view of an image forming apparatus 100 related to the first embodiment. Figure 2 It is a schematic diagram of the configuration of the image forming apparatus 100. As Figure 1 and Figure 2 shown, the image forming apparatus 100 of the present embodiment is a wide-format serial inkjet recording apparatus.

[0035] In the present embodiment, a wide-format serial inkjet printer is exemplified to illustrate the liquid ejection apparatus to which the present invention is applicable, but any image forming apparatus such as a multifunction machine, a printer, a scanner, or a facsimile apparatus having at least two of a copying function, a printing function, a scanning function, and a facsimile function can be applied to the present invention.

[0036] As Figure 1 and Figure 2As shown, the image forming apparatus 100 includes side plates 21A and 21B on the left and right sides of the apparatus main body 100a. The side plates 21A and 21B are used to support the main guide shaft 31 as a guiding member. The image forming apparatus 100 further includes an auxiliary metal plate guide 32. The main guide shaft 31 and the auxiliary metal plate guide 32 hold the carriage 121, and the carriage 121 can slide.

[0037] The carriage 121 is moved in the direction of arrow Y (main scanning direction) by a timing belt driven by the main scanning motor 117 (see Figure 3 ), and moves relative to the medium 40. The movement of the carriage 121 can also be referred to as scanning. The carriage 121 further mounts an optical sensor 37 for detecting the end (paper end) of the medium 40.

[0038] The optical sensor 37 is an example of a reading unit for outputting 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 photographs the image formed on the medium 40, etc. can be used.

[0039] The carriage 121 includes ejection heads 122a, 122b, and 122c 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) with the mounted ink cartridges 10. (These three ejection heads 122a, 122b, and 122c are collectively referred to as "liquid ejection head 122".)

[0040] The conveyance rollers are rotated by the sub-scanning motor 118 (see Figure 3 ), and move the medium 40 in the sub-scanning direction (direction of arrow X) substantially orthogonal to the main scanning direction (Y direction), so as to move relative to the liquid ejection head 122. However, the main scanning direction (Y direction) and the sub-scanning direction (X direction) do not necessarily need to be substantially perpendicular, as long as they intersect.

[0041] Nozzles (not shown) of the ejection heads 122a, 122b, and 122c are arranged in the sub-scanning direction (X direction). The ejection heads 122a, 122b, and 122c are mounted such that the ejection direction of the ink droplets ejected from the nozzles faces downward (Z direction, see Figure 5 ). The ejection heads 122a, 122b, and 122c are overlapped and arranged in the sub-scanning direction (X direction). The carriage 121 mounts sub-tanks for supplying inks of various colors corresponding to the ejection heads 122a, 122b, and 122c respectively.

[0042] "Liquid ejection head" refers to a functional component that discharges or sprays liquid from nozzles. The liquid to be discharged only needs to have a viscosity or surface tension that can be discharged from the liquid ejection head 122, and there is no particular limitation, but a liquid with a viscosity of 30 MPa·s or less at normal temperature and pressure or after heating and cooling is preferred. More specifically, it is a solvent, suspension, emulsion, etc. containing solvents such as water or organic solvents, colorants such as dyes or pigments, polymers, resins, functional imparting materials such as surfactants, biocompatible materials such as DNA, amino acids or proteins, calcium, and edible materials such as natural dyes. These can be used, for example, in applications such as inkjet inks, surface treatment liquids, constituent elements of electronic components or light-emitting elements, or liquid for forming circuit resist patterns, and liquid materials for three-dimensional modeling.

[0043] "Liquid ejection head" serves as an energy generation source for discharging liquid, including devices that use pressure generating devices such as piezoelectric actuators (laminated piezoelectric elements and thin film piezoelectric elements).

[0044] There is no limitation on the pressure generating device used by the "liquid ejection head". In addition to using the above-mentioned piezoelectric actuators (laminated piezoelectric elements), for example, a thermal actuator that uses an electrothermal conversion element such as a heating resistor, an electrostatic actuator composed of a vibrating plate and an opposing electrode, etc. can also be used.

[0045] The image forming apparatus 100 includes a cartridge loading portion 1 for detachably mounting ink cartridges 10y, 10c, 10m, 10k of respective colors (collectively referred to as "ink cartridge 10" when not distinguished).

[0046] The ink in the ink cartridge 10 is supplied to the sub-tank on the carriage 121 for replenishment through the supply pump unit via supply tubes 36 of respective colors. The supply pump unit and the supply tubes 36 constitute a supply mechanism. The ink cartridge 10 may also include a white ink cartridge.

[0047] In the non-printing area in the main scanning direction (Y direction) of the carriage 121 in the image forming apparatus 100, a maintenance and recovery mechanism 81 is provided. The maintenance and recovery mechanism 81 maintains and / or recovers the state of the nozzles of the liquid ejection head 122.

[0048] The maintenance and recovery mechanism 81 includes cover members 82a, 82b, 82c (collectively referred to as "cover member 82" when not distinguished) for covering respective nozzle surfaces of the liquid ejection head 122, a wiping unit 83 for wiping the nozzle surfaces, etc. Below the liquid ejection head 122 in the maintenance and recovery mechanism 81, an exchangeable waste liquid tank is provided for storing waste liquid generated by the maintenance and recovery operation.

[0049] The "liquid discharge unit" is an integrated unit that combines the functional components and mechanisms of the liquid discharge head 122, and is an assembly of components related to liquid ejection. For example, the "liquid discharge unit" includes a unit that combines at least one of the discharge head tank (sub-tank of the carriage 121), the carriage 121, the supply mechanism, the maintenance and recovery mechanism 81, and the main scanning movement mechanism with the liquid discharge head 122.

[0050] Here, the so-called integration means, for example, a unit in which the liquid discharge head 122 and the functional components and mechanisms are fixed to each other by fastening, bonding, engaging, etc., and one is movably held relative to the other. The liquid discharge head 122, the functional components, and the mechanisms may also be configured to be detachable from each other.

[0051] Regarding the liquid discharge unit, for example, there is a unit in which the liquid discharge head 122 and the head tank are integrally formed. There is also a unit in which the liquid discharge head 122 and the discharge head tank are integrated by being connected to each other through pipes or the like. A unit including a filter may also be added between the discharge head tank and the liquid discharge head 122 of these liquid discharge units.

[0052] The integrated unit of the liquid discharge head 122 and the carriage 121 may also be used as the liquid discharge unit.

[0053] As the liquid discharge unit, there is also a structure in which the liquid discharge head 122 is held on the guide shaft 31, which is a guide member forming a part of the main scanning movement mechanism, so as to be movable, and the liquid discharge head 122 and the main scanning movement mechanism are integrated. In addition, there is a structure in which the liquid discharge head 122, the carriage 121, and the main scanning movement mechanism are integrally formed.

[0054] As the liquid discharge unit, there is a structure in which the cap member 82, which is a part of the maintenance and recovery mechanism 81, is fixed to the carriage 121 provided with the liquid discharge head 122, so that the liquid discharge head 122, the carriage 121, and the maintenance and recovery mechanism 81 are integrally formed.

[0055] Furthermore, as the liquid discharge unit, there is also a structure in which a supply pipe 36 is connected to the liquid discharge head 122 on which the discharge head tank (sub-tank of the carriage 121) or the flow path member is installed, and the liquid discharge head 122 and the supply mechanism are integrated. Through this pipe, the liquid from the liquid storage source is supplied to the liquid discharge head 122.

[0056] The main scanning movement mechanism further includes the guide shaft 31 alone as the guide member. The supply mechanism further includes the supply pipe 36 alone and the cartridge loading portion 1 alone.

[0057] Figure 3 It is a block diagram of a hardware structure of an example of the image forming apparatus 100. As Figure 3As shown, the image forming apparatus 100 includes a control unit 101, an operation panel 114, an environment sensor 115, an optical sensor 37, a discharge head driver 116, a main scanning motor 117, a sub-scanning motor 118, a fan 119, a heater 120, a liquid discharge head 122, and a moving mechanism 140.

[0058] As Figure 3 shown, the control unit 101 includes a CPU (Central Processing Unit) 102, a ROM (Read Only Memory) 103, a RAM (Random Access Memory) 104, an 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 (input / output) 113. The control unit 101 may also include components other than those described above.

[0059] The CPU 102, ROM 103, RAM 104, NVRAM 105, ASIC 106, I / F (interface) 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 communicable with each other via, for example, a bus.

[0060] The CPU 102 controls the overall operation of the image forming apparatus 100. Specifically, the CPU 102 realizes various functions by executing programs stored in the ROM 103 and the like.

[0061] The ROM 103 stores programs executable by the CPU 102 and other fixed data. The RAM 104 temporarily stores image data and the like. The NVRAM 105 retains data even when the power of the image forming apparatus 100 is turned off. The ASIC 106 is a circuit for processing image processing such as various signal processing and permutation replacement, and for controlling input / output signals of other devices as a whole.

[0062] The I / F 107 is an interface circuit for transmitting and receiving data and signals to and from a host. Specifically, the I / F 107 receives print data (image data) generated by a printer driver of a host such as an information processing device, an image reading device, and a photographing device via a cable or a network. That is, the generation and output of print data to the control unit 101 may also be performed by the printer driver on the host side.

[0063] The print control unit 108 is a circuit that generates a drive waveform for driving the liquid ejection head 122 and outputs print data for selecting a drive pressure generation mechanism and various accompanying data to the ejection head driver 116. The pressure generated by the pressure generation mechanism causes the liquid ejection head 122 to eject liquid (ink) from the nozzles.

[0064] The main scan motor drive unit 109 is a circuit for driving the main scan motor 117. The sub-scan motor drive unit 110 is a circuit for driving the sub-scan motor 118. The fan control unit 111 is a circuit that controls the output of the fan 119 to perform air supply at a specified temperature and air volume.

[0065] The heater control unit 112 is a circuit for controlling the heater 120 to reach a set temperature. The I / O 113 is a circuit for obtaining information from the environment sensor 115 and extracting information required to control each part of the image forming apparatus 100. The I / O 113 also inputs detection signals from various sensors other than the environment sensor 115 (for example, the optical sensor 37).

[0066] 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 the bus of the control unit 101, for example.

[0067] The environment sensor 115 is a sensor that detects environmental temperature, environmental humidity, etc., for example. The environment sensor 115 is connected to the I / O 113 of the control unit 101.

[0068] The ejection head driver 116 is a circuit that drives the liquid ejection head 122 by selectively applying drive pulses that make up the drive waveform provided from the print controller 108 to the pressure generation device of the liquid ejection head 122 according to the input image data (for example, dot data or pixel data). The ejection head driver 116 is connected to the print control unit 108 of the control unit 101. For example, the ejection amount is controlled by controlling the amplitude of the drive waveform input to the pressure generation device of the liquid ejection head 122, but other devices can also be used to control the liquid ejection amount.

[0069] The main scan motor 117 is a device that drives the timing belt to rotate and moves the carriage 121 having the liquid ejection head 122 in the main scan direction (the direction of arrow Y). The main scan motor 117 is connected to the main scan motor drive unit 109 of the control unit 101.

[0070] The sub-scanning motor 118 is a device that drives an object, i.e., the medium 40, which is the 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.

[0071] The moving mechanism 140 relatively moves the liquid ejection head 122 and the medium 40. The moving mechanism 140 includes a main guide bar 31, a sub-metal plate guide rail 32, a carriage 121, a conveying roller, etc., and constitutes a main-scanning moving mechanism.

[0072] The moving mechanism 140 relatively moves the liquid ejection head 122 and the medium 40 along the main-scanning direction (Y direction) through the main guide bar 31, the sub-metal plate guide rail 32, the carriage 121, etc. The moving mechanism 140 relatively moves the liquid ejection head 122 and the medium 40 along the sub-scanning direction (X direction) through a conveying roller for conveying the medium 40. In the present embodiment, the relative movement of the moving mechanism 140 in the sub-scanning direction (X direction) is an intermittent movement. The intermittent movement means a movement in which movement and stop alternate.

[0073] The fan 119 is a device that promotes the convection of the air inside the image forming apparatus 100 by driving, and prevents the temperature of the upper part of the image forming apparatus 100 from rising excessively due to the retention of heated air. The fan 119 is connected to the fan control unit 11 of the controller 101.

[0074] Figure 4 It is a functional block diagram example of the control unit 101. Parts that are repeated are omitted in the description. Figure 3 The repeated parts.

[0075] As Figure 4 shown, the control unit 101 has a color separation data generation unit 211 and an ejection control unit 212. The ejection control unit 212 basically controls the ejection of ink.

[0076] After inputting the image data to be printed, the color separation data generation unit 211 generates color separation data for each ink color installed in the image forming apparatus 100 according to the input image data (an example of input image). For example, when the image forming apparatus 100 prints with CMYK inks, the color separation data generation unit 211 generates color separation data for each of CMYK according to the input image data.

[0077] The ejection control unit 212 generates print dot data by using a dot data generation mask for the color separation data of each color generated by the color separation data generation unit 211. Here, the dot data generation mask is, for example, a mask pattern for imaging by mixing print dots with two liquid ejection heads in the overlapping area of the nozzles at the ends of adjacent ejection heads 122a, 122b, 122c.

[0078] The control unit 101 implements these functions (the color separation data generation unit 211, the discharge control unit 212) by the CPU 102 executing a prescribed program. The control unit 101 may also implement part or all of these functions by one or more processing circuits.

[0079] "Processing circuit" includes: a processor programmed by software to execute each function, such as a processor installed by a circuit; and devices such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), or an existing circuit module that are designed to execute each of the functions described above.

[0080] The control unit 101 controls the liquid discharge head 122 and the moving mechanism 140 to relatively move the liquid discharge head 122 and the medium 40 multiple times, while disposing ink on the medium 40. The ink disposed on the medium 40 is fixed to the medium 40 to form dots in the image. More specifically, after one ink droplet formed by the ink discharged from the liquid discharge head 122 drops onto the medium 40, it dries and is fixed to the medium 40, thereby forming a dot on the image. The image is formed by an aggregate of multiple dots.

[0081] Here, the problems of the prior art are described.

[0082] Figure 5 is a schematic diagram of a mask pattern when the end nozzles of two discharge heads 201a and 201b arranged in the X direction in the prior art overlap and are arranged, Figure 6 is a graph showing the relationship between the discharged droplet amount and the drive frequency characteristics in the prior art, Figure 7 is a schematic diagram of the drive frequency characteristics and the mask pattern in the prior art, Figure 8 is a schematic diagram of the Y deviation and the mask pattern in the prior art. Figure 5 In, the number of nozzles in the overlapping region 202 of the overlapping nozzles in the nozzles 201a and 201b is set to 12 each, but it may be more or less.

[0083] Figure 5 The shown droplet point A represents the state of the printing point when the droplets discharged from the discharge head 201a and the discharge head 201b drop onto the ideal position on the recording medium 203. The droplet point A includes a normal part A1, a normal part A2, and a mask part A3 corresponding to the nozzle overlapping region 202.

[0084] As Figure 5As shown, the normal part A1 of the dropping point A is formed by droplets discharged from the discharge head 201a, and the normal part A2 is formed by droplets discharged from the discharge head 201b.

[0085] As Figure 5 shown, the mask part A3 of the dropping point A is formed by droplets discharged from the nozzles in the nozzle overlapping area 202 of the discharge head 201a and the discharge head 201b. Figure 5 The mask part A3 of the dropping point A shown represents an example of XY equal mask processing in which the printing points formed by the discharge head 201a and the discharge head 201b are alternately arranged in both the X direction and the Y direction. Through this XY uniform mask processing, the mask part A3 mixes the printing points of the two discharge heads 201a and 201b to form an image, thereby being able to suppress deviations in the discharge characteristics of the discharge heads 201a and 201b, uneven concentrations, streaks, and other image quality degradations caused by dripping deviations due to airflows at the ends of the liquid discharge heads.

[0086] As Figure 6 shown, generally, as the driving frequency of the driving waveform varies, the residual vibrations of the residual pressure wave after discharge are different, and thus, fluctuations in the discharge amount of the liquid discharge head are caused. Figure 6 This is an example where "droplet amount 1" at a driving frequency F becomes reduced to "droplet amount 2" when the driving frequency changes to (1 / 2)F.

[0087] Specifically, as Figure 7 (a) of shows that in the nozzle overlapping area 202 of the two discharge heads 201a and 201b, when performing XY equal mask processing and allocating printing points, the discharge interval of a single discharge head on the mask part A3 is different from the discharge intervals on the normal parts A1 and A2. Therefore, as Figure 7 (b) of shows, for the mask part A3 of the dropping point A corresponding to the nozzle overlapping area 202, the driving frequency of each nozzle drops to (1 / 2)F compared to the normal parts A1 and A2. Thus, printing points with "droplet amount 1" are formed for the normal parts A1 and A2, and printing points with "droplet amount 2" are formed for the mask part A3, so that the mask part A3 is sparser than the normal parts A1 and A2, resulting in white spots.

[0088] In addition, as Figure 8 shown, due to the positional deviation (△Y) in the Y direction between the two discharge heads 201a and 201b or the difference in the dripping speeds between the two discharge heads 201a and 201b, if the dripping positions of the printing points of one discharge head deviate relatively, the printing points of the discharge head 201a and the discharge head 201b overlap and drip, and in the mask part A3, a concentration similar to that of the normal parts A1 and A2 cannot be obtained, and moreover, problems of uneven concentration or streaks will occur.

[0089] In this regard, in the nozzle overlapping region 300 (see Figure 9 ) at the ends of two adjacent discharge heads, by reducing the difference in drive frequency characteristics of the amount of discharged droplets between the discharge heads, or the mask pattern for reducing the concentration unevenness or stripe occurrence caused by the positional deviation or droplet velocity difference between the discharge heads, the image quality of the nozzle overlapping region 300 at the end of the discharge head is equalized.

[0090] Figure 9 FIG. is a schematic diagram of an example of a mask pattern according to the first embodiment. Here, the nozzle overlapping region 300 of two discharge heads 122a and 122b will be taken as an example for description.

[0091] As Figure 9 shown, the mask portion A3 of the droplet landing point A is formed by droplets discharged from the nozzles in the nozzle overlapping region 300 of the discharge head 122a and the discharge head 122b. Here, the length of the mask portion A3 in the X direction is 12 pixels. On the other hand, in the nozzle overlapping region 300, imaging can be performed using a total of 24 nozzles, namely 12 nozzles of the discharge head 122a and 12 nozzles of the discharge head 122b. Therefore, there are twice as many nozzles in the ordinary portions A1 and A2 in the nozzle overlapping region 300.

[0092] As Figure 9 shown, in the nozzle overlapping region 300, the ejection control unit 212 of the control unit 101 overlaps the nozzle 1a (in use) of the discharge head 122a with the nozzle 2b (not in use) of the discharge head 122b, and overlaps the nozzle 1b (not in use) of the discharge head 122a with the nozzle 2a (in use) of the discharge head 122b.

[0093] In this way, as Figure 9 shown, in the mask process of the nozzle overlapping region 300, the ejection control unit 212 of the control unit 101 arranges the printing dots formed by the discharge head 122a and the printing dots formed by the discharge head 122b in the X direction, and in the Y direction, the printing dots formed by the same discharge heads 122a and 122b are continuous, thereby forming a mask pattern in the shape of vertical stripes.

[0094] In other words, the pixel data (i.e., the mask pattern) formed by the discharge control unit 212 includes the first pixel data of the discharge head 122a and the second pixel data of the discharge head 122b. The first pixel data includes first pixels arranged along the nozzle row direction and the intersection direction intersecting the nozzle row direction corresponding to the printing dots (pixels) formed by the discharge head 122a, and the second pixel data includes second pixels arranged along the nozzle row direction and the intersection direction corresponding to the printing dots (pixels) formed by the discharge head 122b. Droplets are discharged from the discharge head 122a for the first pixel data, and droplets are discharged from the discharge head 122b for the second pixel data. The pixel data includes the first pixels and the second pixels in the nozzle arrangement direction, and in the nozzle overlapping region, includes one of the first pixels and the second pixels in the intersection direction. Therefore, the discharge control unit 212 forms a longitudinal stripe-shaped mask pattern based on the pixel data, and allows a plurality of nozzles to selectively discharge droplets.

[0095] In addition, the discharge control unit 212 of the control unit 101 sets the number of points continuously discharged from the same discharge head in the direction intersecting the column direction of the nozzle row, that is, the continuous number of "used" nozzles and "unused" nozzles, to 2 points or less.

[0096] In Figure 9 In the example shown in (a) of, since the discharge interval of the mask portion A3 of a single discharge head is the same as the discharge intervals of the normal portions A1 and A2, the driving frequencies of the printing dots of the normal portions A1 and A2 and the mask portion A3 are the same. Thus, since it is not affected by the Figure 6 shown driving frequency characteristics, no Figure 7 difference in droplet volume caused by the difference in driving frequency characteristics shown occurs, and the sizes of the printing dots of the normal portions A1 and A2 and the mask portion A3 can be made consistent.

[0097] Moreover, as shown in (b) of Figure 9 , even if a positional deviation (Y deviation) ΔY occurs in the Y direction between the two discharge heads 122a and 122b, the printing dots formed by the same discharge heads 122a and 122b in the Y direction in the mask pattern are in a continuous longitudinal stripe shape, and thus the printing dots do not overlap each other as in Figure 8 . Therefore, compared with the mask pattern of the prior art, the mask pattern of the present embodiment can suppress phenomena such as uneven density and stripes, which are image quality degradation, from occurring in the nozzle overlapping region 300 between the adjacent discharge heads 122a and 122b.

[0098] Since it is strictly impossible to be completely the same between the discharge head 122a and the discharge head 122b due to the influence of the discharge head structure and temperature, in the nozzle overlapping region 300, by not fixing the region discharged from one discharge head, uneven density and stripes caused by the difference in dot diameter between the discharge head 122a and the discharge head 122b can be suppressed.

[0099] Thus, in this embodiment, the mask pattern of the nozzle overlapping region 300 at the discharge head ends of the adjacent discharge heads 122a and 122b is configured such that the printing dots formed by the discharge head 122a and the printing dots formed by the discharge head 122b are arranged in the X direction, and the printing dots formed by only the same discharge head are arranged in the Y direction. At the same time, the continuous number of "used" nozzles and "unused" nozzles is set to two or less. In this way, it is possible to suppress the occurrence of density unevenness or stripes in the nozzle overlapping region 300 at the discharge head ends of the two adjacent discharge heads 122a and 122b due to the difference in the driving frequency characteristics of the discharged droplet amounts between the two discharge heads 122a and 122b, or the positional deviation or droplet speed difference between the two discharge heads 122a and 122b, thereby equalizing the image quality in the nozzle overlapping region 300 at the discharge head ends of the adjacent discharge heads 122a and 122b.

[0100] Moreover, even if a positional deviation (Y deviation) ΔY occurs in the Y direction between the two discharge heads 122a and 122b, this embodiment can suppress the occurrence of image quality degradation such as density unevenness or stripes in the nozzle overlapping region 300 of the adjacent discharge heads 122a and 122b.

[0101] The computer program executed in the image forming apparatus 100 of this embodiment is provided by being recorded in a computer-readable recording medium such as a CD-ROM, a floppy disk (FD), a CD-R, or a DVD (Digital Versatile Disc) in an installable form or an executable form.

[0102] In addition, it may be configured to store the computer program executed in the image forming apparatus 100 of this embodiment in a computer connected to a network such as the Internet and provide it by downloading through the network. Furthermore, it may be configured to provide or distribute the computer program executed by the image forming apparatus 100 of this embodiment via a network such as the Internet.

[0103] In addition, the computer program executed in the image forming apparatus 100 of this embodiment may also be configured to be pre-installed in a ROM or the like for providing.

[0104] The computer program executed in the image forming apparatus 100 of this embodiment is configured in a modular manner to include the above-described respective parts (the color separation data generation unit 211 and the discharge control unit 212). As actual hardware, the CPU (processor) reads out the computer program product from the above storage medium and executes it, whereby the above-described respective parts are called to the main storage device, and the color separation data generation unit 211 and the discharge control unit 212 are generated on the main storage device.

[0105] In this embodiment, the discharge heads 122a and 122b having two nozzle rows are described, but the present invention is not limited thereto, and it may be a liquid discharge head having eight nozzle rows as shown in Figure 10 or a liquid discharge head having a column configuration other than this.

[0106] In addition, in this embodiment, the multi-pass method in which the carriage 121 reciprocates to discharge dropwise ink is described, but the present invention is not limited thereto, and it may also be used for a line-type discharge head method in which the liquid discharge head is fixed and the medium is moved. In the case of the line-type discharge head method, it can be used as a mask pattern for the uppermost nozzle that is not affected by the air flow in the conveying direction of the medium (the direction crossing the column direction of the nozzle rows). In particular, the conveying speed of an inkjet printer using the line-type discharge head method is fast, the driving frequency is likely to be high, and the influence of the frequency characteristics increases, so a greater effect can be obtained.

[0107] <Second Embodiment>

[0108] In the following description of the second embodiment, the description of the same parts as those in the first embodiment is omitted, and only the differences from the first embodiment are described.

[0109] Manufacturing apparatus of electrode

[0110] The "liquid discharging device" of the present invention also includes a manufacturing device for electrodes and electrochemical elements. The manufacturing device for electrodes is described below.

[0111] Figure 11 It is a schematic diagram of an example manufacturing device for electrodes in the second embodiment. The manufacturing device for electrodes is a device for manufacturing an electrode including a layer having an electrode material by discharging a liquid composition using a head assembly including the liquid discharge head 122 described in the first embodiment.

[0112] Forming apparatus and forming process of layer containing electrode material

[0113] Figure 11The discharging device included in the electrode manufacturing apparatus shown is a head assembly based on the above-described embodiment of the present invention. By discharging a liquid composition from the discharge head included in the head assembly, the liquid composition is applied to an object to form a liquid composition layer. The object (hereinafter sometimes 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 to be formed, and can be appropriately selected according to the purpose. Examples of the object include an electrode substrate (current collector), an active material layer, a layer including a solid electrode material, etc. The object may also be an electrode mixture layer containing an active material on an electrode substrate (current collector). The discharging device and the discharging process may also be a device and a process for directly discharging a liquid composition to form a layer having an electrode material as long as they can form a layer having an electrode material on the discharge object. The discharging device and the discharging process may also be a device and a process for indirectly discharging a liquid composition to form a layer having an electrode material.

[0114] <Other configurations and processes>

[0115] Regarding other configurations included in the manufacturing apparatus for the electrode mixture 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. Other processes included in the manufacturing method of the electrode mixture layer are also 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 the configurations and processes included in the manufacturing apparatus and the manufacturing method for the electrode mixture layer, a heating device and a heating process can be cited.

[0116] The heating device included in the manufacturing apparatus for the electrode mixture layer is a device for heating the liquid composition discharged by the discharging device. The heating process included in the manufacturing method of the electrode mixture layer is a process for heating the liquid composition discharged in the discharging process. By heating the liquid composition, the liquid composition layer can be dried.

[0117] Configuration for directly discharging liquid composition to form layer containing electrode material

[0118] Here, a manufacturing apparatus for an electrode in which an electrode mixture layer containing an active material is formed on an electrode substrate (current collector) will be described as an example of an electrode manufacturing apparatus. As Figure 11 shown, the electrode manufacturing apparatus includes a discharging process section 150 and a heating process section 130. Among them, the discharging process section 150 includes a process of applying a liquid composition to a printed circuit board 704 having a discharge object to form a liquid composition layer, and the heating process section 130 includes a heating process of heating the liquid composition layer to obtain an electrode mixture layer.

[0119] The electrode manufacturing apparatus includes a conveyance unit 705 that conveys a printed circuit board 704. The conveyance unit 705 conveys the printed circuit board 704 at a preset speed in the order of the discharge process unit 150 and the heating process unit 130. There is no particular limitation on the manufacturing method of the printed circuit board 704 having a discharge object such as an active material layer, and an existing method can be appropriately selected. The discharge process unit 150 includes a liquid discharge head 122, a storage container 281b, and a supply pipe 281. Among them, the liquid discharge head 122 is used to perform a liquid application process of applying a liquid composition onto the printed substrate 704. The storage container 281b is used to store the liquid composition 707. The supply pipe 281 supplies the liquid composition 707 stored in the storage container 281b to the liquid ejection head 122.

[0120] In the ejection process unit 150, the liquid composition 707 is discharged from the liquid discharge head 122, and the liquid composition 707 is applied onto the printed circuit board 704 to form a thin film-like liquid composition layer. The storage container 281b can be integrally formed with the manufacturing apparatus of the electrode mixture layer, or can be a structure detachable from the manufacturing apparatus of the electrode mixture layer. The storage container 281b can be integrally formed with the manufacturing apparatus of the electrode mixture layer, or is a container for being installed in a storage container detachable from the manufacturing apparatus of the electrode mixture layer.

[0121] The storage container 281b and the supply pipe 281c can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0122] In the heating process unit 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 dried by heating with the heating device 703 of the heating process unit 130, thereby removing the solvent in the liquid composition layer. Thus, an electrode mixture layer is formed. The solvent removal process in the heating process unit 130 can also be performed under reduced pressure.

[0123] The heating device 703 can be appropriately selected according to the purpose and there is no particular limitation. For example, the heating device 703 can be a circuit board heater, an IR heater, a warm air heater, etc. The heating device 703 can be a combination of at least two of a circuit board heater, an IR heater, and a warm air heater. Regarding the heating temperature and heating time, they can be appropriately selected according to the boiling point of the solvent contained in the liquid composition 707 or the film thickness to be formed.

[0124] By using the electrode manufacturing apparatus according to the embodiments of the present invention, a liquid composition can be discharged to a target site of a discharge object. The electrode mixture layer can be preferably used as a part of an electrochemical module, for example. In addition to the electrode mixture layer, other components in the electrochemical module are not particularly limited, and existing components can be appropriately selected. For example, components other than the electrode mixture layer include a positive electrode, a negative electrode, a separator, and the like.

[0125] The "liquid discharging apparatus" in the present invention is a liquid discharging apparatus that includes a liquid discharging head 122 or a liquid discharging unit and drives the liquid discharging head 122. The liquid discharging apparatus includes, in addition to being able to discharge liquid to an object capable of attaching the liquid, a liquid discharging apparatus that discharges liquid into a gas or a liquid.

[0126] The "liquid discharging apparatus" includes mechanisms related to the conveyance, handling, and paper discharge of an object capable of attaching the liquid. In addition, it may include a pre-treatment apparatus, a post-treatment apparatus, and the like.

[0127] Examples of the "liquid discharging apparatus" include an apparatus that discharges ink to form an image on paper, that is, an image forming apparatus, and a three-dimensional modeling apparatus (3D modeling apparatus) that discharges a modeling liquid to a powder layer formed into a layer of powder in order to form a three-dimensional object (3D object).

[0128] In addition, the "liquid discharging apparatus" is not limited to an apparatus that makes a meaningful image such as text or a graphic visible by the discharged liquid. For example, an apparatus that forms a pattern or the like that has no meaning in itself, and an apparatus that forms a three-dimensional image are also included.

[0129] The above-mentioned "object capable of attaching the liquid" refers to an object that can at least temporarily attach the liquid, that is, an object that can attach and fix, an object that can attach and penetrate, and the like. For example, there are recording media such as paper, recording paper, recording sheets, films, and cloths, electronic components such as electronic circuit boards and piezoelectric components, powder layers (powder layers), organ models, media such as inspection units, and all media that can attach the liquid as long as there is no particular limitation.

[0130] The material of the above-mentioned "object capable of attaching the liquid" only needs to be paper, thread, fiber, cloth, leather, metal, plastic, glass, wood, ceramic, etc., as long as it can attach the liquid even temporarily.

[0131] In addition, the "liquid" only needs to have a viscosity or surface tension that can be ejected from the liquid ejection head 122, and there is no particular limitation, but a liquid having a viscosity of 30 MPa·s or less at normal temperature and pressure or by heating or cooling is preferred. More specifically, it is a solution, suspension, emulsion, etc. containing solvents such as water or organic solvents, colorants such as dyes or pigments, functional imparting materials such as polymers, resins, surfactants, bio-compatible materials such as DNA, amino acids or proteins, calcium, and edible materials such as natural pigments. For example, it can be used in applications such as inkjet inks, surface treatment liquids, structure forming liquids for electronic components or light-emitting elements, or circuit resist patterns, and three-dimensional modeling material liquids.

[0132] The "liquid ejection device" has a device for relative movement of the liquid ejection head 122 and an object to which the liquid can adhere, but the present invention is not limited thereto, and may also include, for example, a serial method device for moving the liquid ejection head 122, a linear method device for moving the liquid ejection head 122 without movement, and the like.

[0133] In addition to this, the "liquid ejection device" also has a treatment liquid coating device, a spray granulation device, etc. The treatment liquid coating device coats the surface of the paper with a treatment liquid for the purpose of changing the surface properties of the paper and discharges the treatment liquid onto the paper. The spray granulation device ejects a composition liquid used to disperse raw materials into a solution through a nozzle to form fine particles of the raw materials.

Claims

1. A liquid discharge head, comprising a plurality of discharge heads, wherein a nozzle array consisting of a plurality of nozzles is arranged in the discharge head, and liquid droplets are selectively discharged from the nozzles, and adjacent discharge heads in the liquid discharge head are provided with nozzle overlapping areas at the ends of the nozzle array in the row direction, characterized in that: The apparatus comprises a discharge control unit for forming data in a direction parallel to the column direction of the nozzle array in the mask pattern of the nozzle overlap region by using both pixel data of one of the plurality of discharge heads and pixel data of another of the plurality of discharge heads, and forming data in a direction intersecting the column direction of the nozzle array by using pixel data of either the one of the plurality of discharge heads or the other of the plurality of discharge heads, The discharge control unit makes the number of dots discharged from the same discharge head continuous in a direction intersecting the row direction of the nozzle row equal to or less than a predetermined number of dots.

2. The liquid discharge head according to claim 1, wherein The discharge control unit makes the number of dots discharged from the same discharge head continuous in a direction intersecting the row direction of the nozzle row be two or less.

3. A liquid discharge unit, characterized in that: A liquid discharge head according to claim 1 or 2, and at least one of a head tank, a carriage, a supply mechanism, a maintenance recovery mechanism, and a main scanning movement mechanism.

4. A liquid discharge device, characterized in that: A liquid discharge head according to claim 1 or 2, and a control unit for driving the liquid discharge head to discharge liquid.

5. A liquid discharge method for a liquid discharge head, the liquid discharge head having a plurality of discharge heads, a nozzle array consisting of a plurality of nozzles arranged in the discharge head, liquid droplets are selectively discharged from the nozzles, adjacent discharge heads in the liquid discharge head are provided with nozzle overlapping areas at the ends of the nozzle array in the row direction, the liquid discharge method being characterized in that: The method comprises the steps of forming data of a direction parallel to the column direction of the nozzle array in the mask pattern of the nozzle overlap region by using both pixel data of one of the plurality of discharge heads and pixel data of another of the plurality of discharge heads, forming data of a direction intersecting the column direction of the nozzle array by using pixel data of either one of the pixel data of the one discharge head and the pixel data of the other discharge head, In the discharge control step, the number of dots discharged from the same discharge head that are continuous in a direction intersecting the row direction of the nozzle row is set to be less than or equal to a predetermined number of dots.

6. A computer program product for controlling a liquid discharge head by a computer, the liquid discharge head comprising a plurality of discharge heads, a nozzle array consisting of a plurality of nozzles arranged in the discharge head, liquid droplets being selectively discharged from the nozzles, adjacent discharge heads in the liquid discharge head having a nozzle overlap region at the end of the nozzle array in the row direction, the computer program product being characterized in that: The computer functions as a discharge control unit, and the data of the direction parallel to the nozzle array direction in the mask pattern of the nozzle overlap area is composed of both the pixel data of one of the plurality of discharge heads and the pixel data of another of the plurality of discharge heads, and the data of the direction intersecting the nozzle array direction is composed of the pixel data of the one discharge head and the pixel data of any one of the pixel data of the other discharge head, The discharge control unit sets the number of dots discharged from the same discharge head that are continuous in a direction intersecting the row direction of the nozzle row to be less than or equal to a predetermined number of dots.

Images