JP2020104435A - Image formation apparatus and image formation control method - Google Patents

Abstract

To provide an image formation apparatus and an image formation control method which can more easily perform the recording operation while suppressing the reduction in the image quality.SOLUTION: An image formation apparatus includes a conveyance unit of a recording medium, an acquisition unit for movement information of the recording medium, a recording operation unit which has a plurality of recording elements and a recording control unit 251. The recording elements are divided by a plurality of recording heads 211a-211h for each plurality. Each recording head performs image formation in different recording ranges in the width direction orthogonal to the movement direction of the recording medium. The recording ranges adjacent to each other in the width direction partially overlap each other in the width direction. The driving data of each recording element is set so that the recording operation is not performed within a range equal to or greater than a maximum value of the positional deviation amount of the recording medium from the edge of the recording range. The recording control unit changes the correspondence between the driving data and the recording element at the position according to the positional deviation amount obtained on the basis of the movement information for each row for each recording head.SELECTED DRAWING: Figure 4

Description

The present invention relates to an image forming apparatus and an image forming control method.

There is an image forming apparatus that ejects ink from a large number of nozzles to land it on a recording medium and record an image on the recording medium (including a three-dimensional three-dimensional structure and film formation without color). In this image forming apparatus, in response to a demand for speeding up and precision, the recording medium is relatively moved with respect to the nozzle in a predetermined direction so as to extend across a recordable width of the recording medium in a width direction intersecting the predetermined direction. There is a single-pass method in which an image is recorded by arranging nozzles without scanning the nozzles.

In this single-pass type image forming apparatus, there is known a technique of using a line head in which a plurality of blocks (element groups) in which a plurality of nozzles are arranged are arranged in the width direction to arrange the nozzles over a recordable width. However, in this case, there is a problem that it is difficult to sufficiently suppress the deviation of the relative position between the blocks during assembly. On the other hand, there is a technique in which adjacent blocks are assembled so as to be slightly overlapped in the width direction, and a nozzle use range in each block is adjusted according to the relative position of the block (Patent Document 1). When an image is recorded by using the line head divided into a plurality of blocks in this way, the processing time can be reduced by dividing the image data corresponding to each block.

JP, 2009-51066, A

However, depending on the transport accuracy of the transport unit that transports the print medium, the print medium may not accurately advance straight in a desired direction, and a periodic misalignment in the width direction may occur, resulting in deterioration of image quality. If the image forming position is to be corrected in accordance with the positional deviation, conventionally, the data corresponding to each block is insufficient or overflows and recording cannot be performed, so that deterioration of image quality cannot be suppressed. On the other hand, there is a problem that it takes time to exchange data across blocks.

An object of the present invention is to provide an image forming apparatus and an image forming control method capable of performing a recording operation more easily while suppressing deterioration of image quality.

In order to achieve the above object, the invention according to claim 1 is
A transport unit for transporting the recording medium,
An acquisition unit that acquires movement information of the recording medium being conveyed,
A recording operation unit having a plurality of recording elements for performing a recording operation,
A control unit,
Equipped with
The plurality of recording elements are divided into a plurality of element groups, one by one,
The plurality of element groups form images in different recording ranges in a width direction orthogonal to a moving direction of the conveyed recording medium in a plane parallel to the recording medium,
The recording ranges adjacent to each other in the width direction partially overlap in the width direction,
The drive data related to the recording operation is set so that the recording operation by the recording element according to a predetermined range from the end in the width direction in the recording range is not performed,
The control unit, for each of the element group, the set drive data associated with the drive element is obtained based on the movement information for each position in the movement direction, the recording. The correspondence between the drive data and the recording element is changed so as to be associated with the recording element at a position corresponding to the amount of positional deviation in the width direction of the medium,
The image forming apparatus is characterized in that the predetermined range is set to be equal to or larger than a maximum width of the periodic change of the positional deviation amount.

According to a second aspect of the invention, in the image forming apparatus according to the first aspect,
The transport section has a mounting member for mounting the recording medium,
The positional deviation amount is obtained based on the movement information related to meandering when the placement member moves.

According to a third aspect of the invention, in the image forming apparatus according to the second aspect,
The placing member is an endless belt.

The invention according to claim 4 is the image forming apparatus according to claim 2 or 3,
An index indicating a reference position is provided on the placement member,
The acquisition unit acquires the movement information of the recording medium based on the detection result of the index.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects,
When there is no driving data corresponding to some of the recording elements due to the change in the correspondence, the control unit causes the recording element to perform a recording operation as driving data corresponding to the some recording element. It is characterized by adding missing data.

According to a sixth aspect of the invention, in the image forming apparatus according to any one of the first to fifth aspects,
The control unit deletes a part of the drive data when there is no recording element corresponding to the drive data due to the change of the correspondence.

The invention described in claim 7 is the image forming apparatus according to any one of claims 1 to 6,
A plurality of first storage units respectively corresponding to the element groups,
The driving data is stored in the plurality of first storage units for each range corresponding to the recording range of the element group and processed in parallel.

The invention according to claim 8 is the image forming apparatus according to claim 7,
The first storage unit is provided on a separate substrate.

According to a ninth aspect of the invention, in the image forming apparatus according to any one of the first to eighth aspects,
A second storage unit that stores reference data indicating a pattern of the periodic change in the positional deviation amount;
The control unit acquires the position shift amount based on the movement information using the reference data.

The invention according to claim 10 is the image forming apparatus according to claim 9,
The reference data may be the same as each of the element groups of the recording operation unit.

The invention according to claim 11 is the image forming apparatus according to any one of claims 1 to 10,
The control unit has an individual control unit corresponding to each of the element groups,
The movement information is synchronously input to the individual control unit.

The invention according to claim 12 is the image forming apparatus according to any one of claims 1 to 11,
The acquisition unit may include an encoder that measures a transport movement amount of the transport unit.

According to a thirteenth aspect of the invention, in the image forming apparatus according to any one of the first to twelfth aspects,
A plurality of the recording operation units,
The plurality of recording operation units are arranged at different positions in the moving direction of the conveyed recording medium, and at least a part performs a recording operation in a color different from that of the recording operation units other than the part. And

The invention of claim 14 is
A transport unit that transports a recording medium, an acquisition unit that acquires movement information of the transported recording medium, and a recording operation unit that has a plurality of recording elements that perform a recording operation, and the plurality of recording elements, Each of the plurality of element groups is divided into a plurality of element groups, and the plurality of element groups form images in different recording ranges in a width direction orthogonal to a moving direction of the conveyed recording medium in a plane parallel to the recording medium. In the image forming control method of the image forming apparatus, the recording ranges adjacent to each other in the width direction are partially overlapped in the width direction.
An initial setting step of setting the drive data related to the recording operation so that the recording operation by the recording element according to a predetermined range from the end in the width direction in the recording range is not performed,
For each of the element groups, the set driving data associated with each of the driving elements is obtained based on the movement information for each position in the movement direction, and the width direction of the recording medium. Adjustment step for changing the correspondence between the drive data and the recording element so that the recording element is associated with the recording element at a position corresponding to the positional deviation amount of
Including
The predetermined range is defined to be equal to or larger than a maximum width of the periodical change in the positional deviation amount.

According to the present invention, there is an effect that a recording operation can be performed more easily while suppressing deterioration in image quality.

FIG. 1 is an overall perspective view of an inkjet recording apparatus that is an embodiment of an image forming apparatus of the present invention. FIG. 6 is a bottom view showing a surface of the head unit that faces a carrying surface. FIG. 3 is a block diagram showing a functional configuration of an inkjet recording device. It is a figure which shows the structure regarding the process of image data. It is a flow chart which shows a processing procedure of a drive picture. It is a figure explaining the shift of the image data with respect to meandering. It is a figure explaining the shift of the image data with respect to meandering. FIG. 7 is a diagram illustrating a complementary operation of an ink ejection failure nozzle.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is an overall perspective view of an inkjet recording apparatus 100 that is an embodiment of the image forming apparatus of the present invention.

The inkjet recording apparatus 100 has a plurality of line heads, eight line heads in this case, and is capable of recording a color image by ejecting ink by a single-pass method. The recording operation unit 20, the ink supply unit 30, the transport detection unit 41, the image detection unit 42, and the like are provided.

The transport unit 10 includes a drive roller 11, a transport drive unit 12, a transport belt 14 (mounting member), and the like. The transport drive unit 12 has a rotary motor that rotates the drive roller 11 at a predetermined speed. An endless conveyor belt 14 is wound around the drive roller 11 together with a driven roller (not shown), and the conveyor belt 14 is rotated by the rotation of the drive roller 11. Using the outer surface of the conveyor belt 14 as a conveyor surface, the conveyor unit 10 places a recording medium on the conveyor surface in a predetermined range, and moves the recording medium in a circular movement direction along with the circular movement of the conveyor belt 14. The recording medium is conveyed in the moving direction of the recording medium, that is, the conveying direction. The type of the recording medium is not particularly limited, but here, it is a continuous cloth or the like, and for example, roll-shaped cloth can be sequentially sent out, placed on the transfer surface, and transferred.

The recording operation unit 20 includes a carriage 22, a carriage elevating unit 23, and the like. The number of the recording operation units 20 is eight (eight in this case) according to the number of ink colors (eight is provided). Each of the carriages 22 extends in a direction intersecting with the transport direction of the transport unit 10 in a plane parallel to the transport surface, here, in a width direction orthogonal to each other, and above the transport surface of the recording medium by the transport unit 10. It is arranged in the (height direction). Each of the carriages 22 extends from the nozzle opening (nozzle opening 27a; see FIG. 2) over the entire width of the recording medium to be conveyed (a recordable width in the width direction. There may be some margin at both ends or one end). A head unit 21 (see FIG. 2; line head) is fixed so that ink droplets can be ejected. A recording element 26 (see FIG. 3) included in each of the eight (plural) head units 21, here, a nozzle, an ink flow path (ink chamber), and a configuration for ejecting ink from each nozzle (electromechanical conversion element 252 described later) 3 (see FIG. 3) (the number is plural) is appropriately determined according to the recording resolution, the size of the recording medium that can be recorded by the inkjet recording apparatus 100, and the like. The plurality of carriages 22, that is, the recording operation unit 20 are provided at different positions in the transport direction. The carriage 22 is provided so that the position in the height direction can be changed by the carriage elevating/lowering unit 23, and the distance from the transport surface of the head unit 21 is also changed as the carriage 22 moves. An image is recorded (formed) on the recording medium by ejecting ink from the nozzles when the recording elements 26 perform a recording operation (ejection of ink).

The carriage elevating unit 23 changes the distance from the carrying surface of the carriage 22. The carriage elevating part 23 includes an elevating motor 232, an electromagnetic brake 233, a beam member 234, a support part 235, and the like.
Two beam members 234 are provided substantially parallel to each other on the upper part of the transport belt 14 (on the side of the transport surface of the recording medium) in a direction intersecting the transport direction (here, a direction orthogonal to each other, that is, a width direction). The support portions 235 are fixed to both ends of each. The lifting motor 232, the electromagnetic brake 233, and the carriage 22 are attached to the support portion 235.
The position of the carriage 22 is set up and down according to the operations of the lifting motor 232 and the electromagnetic brake 233 which are driven based on a control signal from the control unit 50 (see FIG. 3).

The lifting motor 232 moves the carriage 22 at a predetermined lifting speed. As the lifting motor 232, for example, a servo motor or a stepping motor is used.

The electromagnetic brake 233 maintains the fixed state of the carriage 22, and when the fixed state is released in response to a drive signal, the movement of the carriage 22 by the elevating motor 232 is temporarily enabled. That is, the electromagnetic brake 233 fixes the carriage 22 in a normal state including when the power supply is cut off. As the electromagnetic brake 233, for example, a disc brake is used.

The ink supply unit 30 stores the ink of each color used for image formation and supplies the ink to the head unit 21. Here, the ink storage tanks 31 of the respective colors are arranged in a dedicated rack 32, and are connected to the head unit 21 for ejecting the inks of the respective colors via pipes such as tubes. The ink of each color is not particularly limited, but here, it is eight colors different from each other, and includes C (cyan), M (magenta), Y (yellow), and K (black). P (pink), S (sky), G (gray) and O (orange) inks (at least a part of which is a color different from the part) can be supplied. The ink of each color is ejected as fine dots by the supplied nozzles of each head unit 21 and lands on a recording medium, and is expressed by a density or a combination thereof according to the number of fine dots or the size of the dots (droplet amount). The mixed color image is recorded. The color of the ink stored in the ink storage tank 31 and supplied to the head unit 21 may be exchangeable.

The conveyance detection unit 41 is located upstream of the recording operation unit 20 in the conveyance direction, detects the origin mark O (index indicating the reference position; see FIG. 6) of the conveyance belt 14, and outputs a detection signal. An origin marker O is provided at a predetermined distance from the end in the width direction of the endless conveyor belt 14 and at a specific position in the revolving movement direction. The conveyance detection unit 41 detects the origin mark O for each revolution of the conveyance belt 14 and outputs the timing. Further, the transport detection unit 41 may be capable of measuring and outputting the position of the origin marker O in the width direction (which may be a relative position from the reference position), if necessary. The origin mark O may be, for example, a mark in a color different from that of the other parts of the conveyor belt 14 or a hole provided in the conveyor belt 14. The transport detection unit 41 may be a sensor that reads the origin marker O or acquires the detection intensity of the reflected light. If a hole is provided as the origin marker O, the conveyance detector 41 penetrates the hole. Then, a transmissive optical sensor that detects incident light on the opposite side may be used. The light is not limited to visible light and may be infrared light or the like. Further, the conveyance detection unit 41 may be capable of directly detecting and specifying the position (edge portion) in the width direction of the recording medium.

The image detection unit 42 is provided on the downstream side in the transport direction with respect to the recording operation unit 20, and images the surface of the recording medium on which the image is recorded (or passes without being recorded) by the recording operation unit 20. read. The image detection unit 42 may include an illumination unit (not shown). The illumination unit illuminates the image pickup surface (the surface of the recording medium) by the image detection unit 42 substantially uniformly.

The image detection unit 42 includes, for example, a one-dimensional image sensor. In the one-dimensional image sensor, here, a plurality of image sensors are arranged at least across the width of the conveyor belt 14 in the width direction. The image detecting unit 42 can two-dimensionally image the recording medium by moving the recording medium in the conveying direction by the operation of the conveying unit 10. As the image sensor, a CCD sensor (Charge Coupled Device) or a CMOS sensor (Complementary Metal Oxide Semiconductor) is used. These image pickup sensors perform an image pickup operation in each image pickup device, in which an electric charge amount or a voltage corresponding to the amount of light input to the light receiving device from the surface of the recording medium via the optical system (lens) is output. Here, the image sensor is capable of imaging in each wavelength band of RGB (a plurality of wavelength bands), and the image detection unit 42 can acquire a color read image. The image detection unit 42 is used to previously specify the meandering information 63 and 255 described later (for example, to detect a change pattern of a deviation amount of a straight line formed on a recording medium in the width direction in the width direction). You can
It should be noted that the conveyance detection unit 41 and the image detection unit 42 may have variable distances from the conveyance surface, like the carriage 22.

FIG. 2 is a bottom view showing a surface of the head unit 21 that faces the carrying surface.
Here, since the head units 21 of the respective colors have the same shape and configuration, any one of them will be described.

Here, the head unit 21 has eight recording heads 211a to 211h (element group; hereinafter, a part or all of them are collectively referred to as a recording head 211) fixed. The bottom surface of each recording head 211 is provided with a nozzle array in which nozzle openings 27a of a plurality of nozzles 27 are arranged in a width direction at a predetermined nozzle pitch. The positions of the nozzle openings 27a may be different in the carrying direction as long as they are arranged at a predetermined interval in the width direction. The number and size of the nozzle openings 27a shown in this figure are for explanation purposes, and as will be described later, the number is actually larger than this, and the size is the arrangement range in the width direction of the nozzle openings 27a. Small enough compared to the width of.

The eight recording heads 211 included in one head unit 21 are arranged in a zigzag pattern at different positions. Along with this, the arrangement ranges of the nozzle openings 27a in the recording heads 211 in the width direction are different from each other, and accordingly, it is possible to perform image formation in different recording ranges. The ends of the arrangement range (that is, the recording range of the recording heads 211) in the width direction of the nozzle openings 27a of the adjacent recording heads 211 are slightly overlapped. Therefore, in the head unit 21, the above nozzle pitch is spread over the entire width of the recording medium M (there may be a slight margin at both ends) in the width direction by combining the recording ranges in the width direction of each of the eight recording heads 211. Then, ink can be ejected from a plurality of nozzles divided in each recording head 211.

FIG. 3 is a block diagram showing the functional configuration of the inkjet recording apparatus 100.

The inkjet recording apparatus 100 includes a conveyance unit 10, a recording operation unit 20, a detection unit 40 (acquisition unit), a control unit 50, a storage unit 60, a communication unit 70, a display unit 81, and an operation reception unit 82. And a bus 90 and the like. The transport unit 10 has the transport driving unit 12 described above. The detection unit 40 includes the above-described transport detection unit 41 and image detection unit 42.

The recording operation unit 20 includes a carriage drive unit 24, a head drive unit 25, and the like. The carriage drive unit 24 outputs a drive signal to the above-described lift motor 232, electromagnetic brake 233, etc. to operate or fix them. As described above, the electromechanical conversion element 252 and the nozzle 27 are included in the recording element 26.

The head drive unit 25 includes a recording control unit 251 (individual control unit). The recording control unit 251 outputs a drive signal that causes a pressure fluctuation in the ink in the ink flow path communicating with each nozzle 27 of the recording head 211 based on the control of the control unit 50. As a configuration for causing the pressure fluctuation, for example, an electromechanical conversion element 252 (here, a piezoelectric element) is used, and the electromechanical conversion element 252 is deformed according to an applied voltage, that is, an output voltage of a drive signal. Then, the ink flow path, in particular, the pressure chamber that is formed with a size and a shape in order to appropriately generate pressure fluctuation is deformed. As the drive signal, one or a plurality of voltage waveform patterns are defined in advance, and the electromechanical conversion elements 252 corresponding to the respective nozzles according to the control signal from the controller 50 and the drive data (halftone image data). With respect to, the presence or absence of the output of the drive signal in the voltage waveform pattern is determined. The ink pushed out from the nozzle opening 27a by the deformation operation of the electromechanical conversion element 252 (recording operation of the recording element 26) by the drive signal is separated from the ink in the ink flow path by an appropriate amount and ejected as an ink droplet. It The output cycle of the drive signal may be fixed to a single cycle or may be finely adjustable. Alternatively, it may be variably set according to the transport speed of the recording medium by the transport unit 10 and the resolution in the transport direction of the image.

Here, the recording control unit 251 is provided corresponding to each of the plurality (eight) of recording heads 211, and operates independently based on the synchronization signals from the conveyance detection unit 41 and the encoder 43. The recording control unit 251 controls the recording operation of each recording head 211 at the output cycle of the drive signal based on the driving data of the image range recorded by the nozzle of the corresponding recording head 211.
The control unit 50 and the recording control unit 251 are included in the control unit according to the embodiment of the present invention.

The detection unit 40 has an encoder 43 in addition to the above-described transport detection unit 41 and image detection unit 42. The encoder 43 detects the rotation of the drive motor of the transport drive unit 12 or the drive roller 11, and outputs a signal according to the rotation direction for each rotation of a predetermined angle. The interval from the previous signal output indicates the rotation speed, that is, the conveyance speed of the recording medium. Further, the position in the rotation direction of the conveyor belt 14 and the position of the recording medium being conveyed are specified by the detection timing of the origin mark by the conveyance detection unit 41 and the number of times the signal is output from the encoder 43. The detection signal of the conveyance detection unit 41, the signal of the encoder 43 for each predetermined angle, and the like are acquired as movement information of the conveyance belt 14 and a recording medium placed on the conveyance belt 14.

The control unit 50 integrally controls the overall operation of the inkjet recording device 100. The control unit 50 includes a CPU 51 (Central Processing Unit), a RAM 52 (Random Access Memory), and the like. The control unit 50 performs various processes related to image formation based on image data, a status signal of each unit, a clock signal, and the like. In addition, the control unit 50 performs processing such as operation adjustment related to ink ejection from each nozzle 27, detection of defective state of ejection operation and its response, and detection and adjustment of image quality deterioration.

The CPU 51 performs various arithmetic processes to control the recording medium conveyance, the ink supply, the ink ejection, the formed image reading operation, and the like in the inkjet recording apparatus 100. The CPU 51 performs calculation and control related to each of the above processes according to the program read from the storage unit 60.

The RAM 52 provides the CPU 51 with a working memory space and stores temporary data. The storage area for the temporary data may be appropriately shared with the DRAM area of the storage unit 60.

The storage unit 60 stores a program 61, various setting data, job data 65 related to an image forming command, and the like. The job data 65 includes image data to be recorded, processed data thereof, information relating to operation settings, and the like. The program 61 includes an identification program of ejection failure nozzles that cause ink ejection failure, various image processing programs, and a distribution setting program in an overlapping range of the arrangement range of the nozzles 27 in the recording head 211. As the setting data, the ejection failure nozzle list 62 indicating the positions of the nozzles (ejection failure nozzles) in which the ejection failure of the ink has occurred, and the meandering information 63 indicating the change pattern of the periodic misregistration amount in the width direction of the recording medium. , And a distribution setting 64 indicating a selection pattern of nozzles capable of ejecting ink in the overlapping range of the adjacent recording heads 211. Plural pieces of the meandering information 63 may be held according to the mode of the meandering appearing in the inkjet recording apparatus 100, the set value of the dependent parameter, and the like.

The storage unit 60 includes a volatile memory such as a DRAM and a non-volatile memory here. Temporary data such as job data and processing data may be stored in a volatile memory, processed at high speed, and deleted after the image forming operation is completed. Programs, setting data, and the like are held by a non-volatile memory and are held even when power is not supplied to the inkjet recording apparatus 100. Some programs and setting data, such as initial data and core programs, may be stored in a non-erasable and rewritable ROM instead of the non-volatile memory.

The communication unit 70 is a communication interface that controls a communication operation with an external device. The communication interface includes, for example, one or a plurality of network cards such as LAN cards that support various communication protocols. The communication unit 70 can acquire image data to be recorded and job data including settings related to image formation from an external device under the control of the control unit 50, and can also send status information and the like to the external device. it can.

The display unit 81 displays the status of the inkjet recording apparatus 100, an operation menu, and the like on the display screen according to a control signal from the control unit 50. Examples of the display screen include a liquid crystal screen and the like. In addition, the display unit 81 may include an LED lamp or the like that warns whether or not power is supplied and/or an error.

The operation receiving unit 82 receives a user operation and outputs it to the control unit 50. The operation reception unit 82 has, for example, a touch sensor or the like. The touch sensor may be provided so as to overlap the display screen of the display unit 81 and used as a touch panel. The control unit 50 outputs information on the position and type of the touch operation detected by the touch sensor to the control unit 50. In addition, the operation reception unit 82 may include a push button switch and/or a numeric keypad.

The bus 90 is a path for electrically connecting the control unit 50 and each component for exchanging signals with the control unit 50 and transmitting the signal.

Next, the flow and processing of image data will be described in more detail.

FIG. 4 is a diagram showing a configuration related to processing of image data.
In the head unit 21 of the inkjet recording apparatus 100, substrates 201a to 201h (collectively referred to as substrate 201) are provided corresponding to the recording heads 211a to 211h, respectively. As described above, the print control unit 251 corresponding to each of the print heads 211a to 211h is provided on each substrate 201, and the processing operations can be performed in parallel. A memory 253 (first storage unit) is provided on each of the substrates 201. Since the configurations of the substrates 201b to 201h are the same as the configuration of the substrate 201a, the description thereof is omitted here.

Drive data (halftone image data) relating to ink ejection from each nozzle 27 (corresponding to the nozzle 27) is input to each substrate 201 based on the job data 65 stored in the storage unit 60. It The drive data is two-dimensionally arrayed according to the array order of the recording elements 26 (nozzles 27) in the width direction and the drive cycle order of ink ejection (that is, the position in the transport direction). The drive data is divided in the width direction for each recording range of each recording head 211 and sent to the memory 253 of each substrate 201. That is, the drive operation of each recording head 211 is independently performed based on the individual data (divided drive data). As described above, the division drive data is generated in such a manner that the arrangement range (image recording range) of the nozzle openings 27a overlaps in the width direction. Here, the entire halftone image data (two-dimensional array data divided in the width direction) in the transport direction is sent to the substrate 201, and is stored in the memory 253 while a part or all of the image is formed a specified number of times. Remembered.

The ejection failure nozzle list 254 and the meandering information 255 (reference data) are stored in the substrates 201a to 201h, respectively. The meandering information 255 is the same as the meandering information 63 stored in the storage unit 60. The ejection failure nozzle list 254 may be the same as the ejection failure nozzle list 62, or may be only the list of ejection failure nozzles in the recording heads 211a to 211h to which the substrates 201a to 201h correspond, respectively. Here, the ejection failure nozzle list 254 and the meandering information 255 are stored and held in a volatile memory (second storage unit) such as a DRAM. The ejection failure nozzle list 254 and the meandering information 255 are transmitted from the storage unit 60 each time the corresponding data is transmitted when the inkjet recording apparatus 100 is activated or when an explicit update request is made. Is retained during the operation of. Alternatively, the ejection failure nozzle list 254 and the meandering information 255 may be continuously stored in a non-volatile memory or the like as long as the update data is not received.

Further, the detection signals of the conveyance detection unit 41 and the encoder 43 are cascade-connected in series (in a chain shape) to each of the substrates 201a to 201h, and the detection signals are acquired (input) in synchronization with each other.

When the drive data is divided, the control unit 50 determines which one of the two print heads 211 has the overlap range in the width direction of the arrangement range of the nozzles 27 (the print range of the formed image) in the adjacent print heads 211. The driving data is assigned to each. This distribution is performed individually or collectively by a portion mechanically allocated to one recording head 211 and a portion allocated at an appropriate ejection distribution ratio based on the distribution setting 64. All the drive data corresponding to the nozzles of the recording head 211 on the side to which the drive data is not allocated are set to non-ejection so that ink is not ejected regardless of the original drive data.

In each of the substrates 201, the recording control unit 251 determines, in accordance with the meandering of the recording medium (the positional deviation in the periodic width direction), for each driving cycle (each of the above-described predetermined timings) of the acquired divided driving data. The correspondence relationship between the one-dimensional data (row data) in the width direction and the nozzles 27 (recording elements 26) arranged in order in the width direction is shifted (changed) to form an image at a correct position on the recording medium. Adjust to continue. The conveyor belt 14 causes a slight meander according to the accuracy of each part such as the drive roller 11. That is, when the transport belt 14 moves in the revolving movement direction, each position on the transport belt 14 in the revolving movement direction is accompanied by a slight periodic change in the position in the width direction. The recording medium can cause a periodic change in the width direction based on the meandering of the transport belt 14. In each of the substrates 201a to 201h, the conveyance belt 14 is determined by the detection timing of the origin marker by the conveyance detection unit 41 and the movement amount of the conveyance belt 14 (that is, the conveyance movement amount of the recording medium, the movement speed) by the detection signal of the encoder 43. Is specified. By identifying the phase of this periodic change at a desired position and timing based on these movement information of the recording medium, the meandering information 255 in which this periodic change is stored is referred to (used), and the meandering information is referred to. The positional deviation amount in the width direction related to is specified. The recording control unit 251 shifts the correspondence of the driving data in the width direction in units of rows extending in the width direction with the nozzles 27 by an amount corresponding to the positional deviation amount.

Then, based on the ejection failure nozzle list 62, a complementary process of distributing the ejection of the ink assigned to the ejection failure nozzle to the surrounding nozzles is performed. The driving data after the complementary processing is sent to the recording head 211a at an appropriate timing according to the clock signal to deform the electromechanical conversion element 252.

FIG. 5 is a flowchart showing the processing procedure of the drive image.
FIG. 5A is a flowchart showing a control procedure of the drive image division processing by the control unit 50. FIG. 5B is a flowchart showing the control procedure of the drive image output processing by each recording control unit 251. These processes are included in the image formation control method of this embodiment.

The drive image division process is started after the control unit 50 generates a halftone image as drive image data. The control unit 50 acquires a halftone image (step S101). The control unit 50 sets the recording range (arrangement range of the nozzles 27) on each substrate 201 for the halftone image (step S102). The recording range is defined by the substrate 201 corresponding to each recording head 211 in the overlapping range.

The control unit 50 uses the distribution setting 64 to execute the distribution processing of the overlapping range. The control unit 50 divides the data range corresponding to the recording range corresponding to each substrate 201 together with the above-described overlapping range (after the sorting process) (step S103; initial setting step). The controller 50 outputs the divided driving data (divided driving data) to each substrate 201 (step S104). Then, the control unit 50 ends the drive image division process.

The drive image output process by the recording control unit 251 of the substrate 201 is started in response to the division drive data being input to the memory 253. The recording control unit 251 acquires and reads the division drive data (step S201). The recording control unit 251 acquires the position information and speed information (collectively movement information of the recording medium) of the conveyor belt 14 based on a synchronization signal from the encoder 43 or the like, and based on these information and the meandering information 255, Next, the timing at which the ink ejected from the nozzles 27 lands in accordance with the row data (linear (raster) data extending in the width direction at a predetermined position in the transport direction) output to the recording head 211 (generally, the nozzle The positional deviation amount (meandering amount) in the width direction of the recording medium at the landing position at the ejection timing from 27 may be acquired (step S202).

The recording control unit 251 performs a correction for shifting the above-described row data with respect to the nozzles 27 (recording elements 26) (that is, the correspondence relationship with the nozzles 27) by the number of nozzles corresponding to the acquired positional deviation amount. Perform (step S203). The processing of these steps S202 and S203 constitutes the adjustment step of this embodiment. The recording control unit 251 refers to the ejection failure nozzle list 254 to determine whether or not ink is ejected from the set ejection failure nozzle. When the ejection failure nozzle is set to eject ink, the recording control unit 251 performs ejection failure complementing processing in which the ejection of the ejection failure nozzle is complemented by another nozzle (step S204). The recording control unit 251 outputs the driving data of the row subjected to the above processing to each recording head 211 a predetermined time before the ejection operation (step S205).

The recording control unit 251 determines whether or not the output of all the output target rows (total number of rows) has been completed (step S206). The total number of rows corresponds to the total number of rows when a part or all of the divided drive data is output a designated number of times (the output range may be changed every output). When it is determined that the output of the total number of lines is completed (“YES” in step S206), the recording control unit 251 ends the drive image output process. When it is determined that the output of the total number of lines has not ended (“NO” in step S206), the recording control unit 251 determines whether the output of the total number of lines in this output has ended. (Step S207). When it is determined that the processing is not completed (“NO” in step S207), the process of the recording control unit 251 returns to step S202. When it is determined that the output of all the rows is completed (“YES” in step S207), the recording control unit 251 returns the next output row to the head row of the division drive data (step S208). Then, the process of the recording control unit 251 returns to step S202.

Next, the meandering correction and the ejection failure complement in the drive image output process will be described.

6 and 7 are diagrams illustrating the shift of image data (driving data) with respect to meandering.

As described above, the meandering period L and the amplitude Wm (the maximum amount of movement in the width direction is twice (2 Wm) in the width direction) in the spatial structure are determined according to the above-mentioned structural characteristics and arrangement (Fig. 6(a)). At a position Xi of a certain head unit 21, a cycle change (positional deviation) in the width direction of the conveyor belt 14 due to the meandering cycle L and the amplitude Wm is a component and/or a conveyor that moves with the circular movement of the conveyor belt 14. It may be the sum of the components that vibrate at each position on the belt 14 (a predetermined position in the system that moves as the transport belt 14 moves around). The parameters of the cycle change corresponding to these are inspected and held in advance. When the positional deviation of the recording medium with respect to the conveyor belt 14 is more periodically present, the phase of this positional deviation is measured and acquired at a predetermined time point. Alternatively, if it is determined by the distance between the position XL where the recording medium is placed on the conveyor belt 14 and the detection position X0 by the conveyance detector 41, it is held in advance. The positional deviation amount (for example, a value in units of nozzle pitch) at each phase (relative position from the reference position) within the meandering period L is a predetermined phase interval (or position in the revolving direction of the conveyor belt 14). It is stored and held as the meandering information 63, 255 in association with the phase and/or the position for each (interval).

The phase at the ink landing timing at the ink landing position from the nozzle 27 based on the drive data (row data) is the above parameters, the distance between the position Xi which is the ink landing position and the detection position X0 by the carry detection unit 41, and the carrying position. It is estimated (here, specified within a slight error range) based on at least a part of the detection result (conveyance speed, the detection timing of the origin marker O, and the obtained position in the width direction) by the detection unit 41. The necessary detection content is predetermined (in the present embodiment, the transport speed by the encoder 43 and the detection result by the transport detection unit 41) can be acquired. Of the driving data distributed to the memory 253 of the substrate 201 related to each recording head 211, the row data corresponding to the ink landing timing related to the estimated (specified) misalignment amount was estimated as described above. The correspondence relationship with the nozzle 27 is shifted (changed) so as to cancel the positional deviation amount corresponding to the phase (so that each driving data is associated with the nozzle 27 at the position corresponding to the positional deviation amount).

When the row data is shifted with respect to each recording head 211, the driving data is not exchanged between the substrates 201 corresponding to the adjacent recording heads 211, so that the driving data is transferred at one of the shifted ends. On the other hand, there is no driving data. One or the other of these may be reversed depending on the direction of shift. In the present embodiment, all of the drive data that can exceed the recording range is set to non-ejection so that ink is not ejected from the nozzle 27.

As shown in FIG. 6B, at both ends of the overlapping range D of the nozzle arrangement range (image recording range) in the adjacent recording heads 211 (here, the recording heads 211a and 211b), the amplitude Wm is determined. (Here, the amplitude is equal to Wm, that is, the maximum value (maximum width) of the positional deviation amount, but the total width is larger than the maximum width within the overlapping range D or less (each half or less of the width of the overlapping range D). Areas Da and Db (which may be present) (predetermined range) are predetermined. In the area Da, which is the end portion of the recording head 211a, the ink is not ejected from the nozzles of the recording head 211a (the recording operation by the recording element is not performed). All of this amount of ink is set to be ejected from the nozzles of the recording head 211b. In the area Db, which is the end portion of the recording head 211b, the ink is not ejected from the nozzles of the recording head 211b (the recording operation by the recording element is not performed). All of this amount of ink is set to be ejected from the nozzles of the recording head 211a. The center portion of the overlapping range D excluding the areas Da and Db is distributed by the distribution setting 64 so that ink is ejected complementarily from the nozzles 27 of either of the recording heads 211a and 211b as usual. To be Here, the ejection distribution ratio, which is the proportion of ink that can be ejected, is set to gradually increase with increasing distance from the end of the arrangement range (image recording range). The conventional method may be determined by an appropriately known method. Here, the setting for not ejecting ink to the nozzles 27 in the areas Da and Db is made separately from the distribution setting 64, but may be included in the distribution setting 64.

As shown in FIG. 7A, when the desired recording target range a of the recording head 211a on the recording medium completely overlaps the recording range of the recording head 211a (the same applies to the recording target range b corresponding to the recording head 211b). That is, when the amount of positional deviation of the recording medium is zero, whether or not ink can be ejected from each nozzle 27 is determined according to the original row data (for example, it is possible to eject from the black-painted portion in the drawing). Whether or not the ink is actually ejected from the ejectable portion is determined by the original driving data (halftone image data).In the overlapping range D, ink can be ejected from either one of the recording heads 211a and 211b in a complementary manner. The image of this row is recorded in the correct position. On the other hand, as shown in FIG. 7B, when the recording medium deviates to the right side in the figure by the width W (here, substantially equal to the amplitude Wm) due to the meandering of the conveyor belt 14, the recording medium is on the recording medium. The print target range a and the print target range b are shifted to the right by the width W with respect to the print ranges of the print heads 211a and 211b. In this state, if the ink is ejected with the original row data, the recording position of the image of this row on the recording medium is biased to the left by the width W. Therefore, here, the setting relating to the propriety of ink ejection from each nozzle is shifted (shifted) to the right by the number of nozzles corresponding to the width W.

In this case, as described above, in the initial row data before the shift, it is determined that the ink is not ejected from the nozzle located in the area Da having the width substantially equal to the amplitude Wm from the right end of the recording head 211a. The drive data that is not ejected runs off from the portion of the recording head 211a corresponding to the nozzle 27 and disappears (a part of the drive data is deleted). Since the driving data for the nozzles of the print heads 211a and 211b in this area Da is shifted from the left side (center side of the overlapping range D), complementary ejection is performed, that is, there is no defect such as a defect in the formed image. Does not happen.

Further, for the nozzles (a part of the driving elements) located in the area Db having the width substantially equal to the amplitude Wm from the left end of the recording head 211b, the corresponding driving data disappears due to the above-mentioned shift. On the other hand, in both cases, drive data for making ink non-ejection is added. Since the data for driving the nozzles of the area Db in the recording head 211a is originally shifted from the left side and is outside the overlapping range, ink is ejected from all the nozzles 27 of the recording head 211a in this area Db. .. Therefore, even in this area Db, no abnormality such as ink ejection loss occurs.

That is, with such a setting, it is not necessary to exchange information between the adjacent recording heads 211 when shifting the position of ink ejection propriety.
It should be noted that the above processing cannot deal with both ends of the recording range in the entire line head that is not the overlapping portion. Therefore, when the halftone image is created by the control unit 50, margins (areas where an image is not formed) having a width corresponding to the amplitude Wm may be provided at both ends in the width direction of the line head (head unit 21). ..

FIG. 8 is a diagram for explaining the complementary operation of the ink ejection failure nozzle.
In this ink jet recording apparatus 100, after the position (row data) of whether or not ink can be ejected is shifted according to the meandering, a complementary operation is performed when there is ejection failure in each nozzle to which ink ejection is finally assigned.

As shown in FIG. 8A, when the nozzle 27f1 is an ejection failure nozzle, the ink from the nozzle 27f1 is originally set to be non-ejection (impossible) in this row, so it is necessary to perform the complementary process. Absent. On the other hand, as shown in FIG. 8B, when the shift is performed according to the width W (the amount of positional deviation), the ejection from the nozzle 27f1 is set to be enabled, and therefore, if necessary. That is, when it is set that ink is actually ejected from the nozzle 27f1 according to the original drive data (halftone image data), the ink is not ejected from this nozzle 27f1 and is ejected from other nozzles. Perform complement processing. In this case, for example, the distribution may be simply changed to the nozzles at the same position in the width direction of the recording head 211b.

When the nozzle 27f2 outside the overlapping range D is a defective ejection nozzle, this nozzle 27f2 is always a nozzle capable of ejecting ink. Therefore, when there is an actual ink ejection setting from the nozzle 27f2, the adjacent nozzle 27c2 or the like instead of the nozzle 27f2 is set to perform complementary ink ejection. In this case, the complementary ejection from the nozzle 27c2 is not limited to the timing at which ink ejection was originally set for the nozzle 27f2, that is, not limited to the same row data, and the next ink ejection timing, that is, the next row data. May be carried over.

As described above, the inkjet recording apparatus 100 according to the present exemplary embodiment includes the transport unit 10 that transports the recording medium, the detection unit 40 that acquires the movement information of the transported recording medium, and the plurality of recording elements 26 that perform the recording operation. A recording operation unit 20 having a nozzle 27 and an electromechanical conversion element 252), and a control unit 50. The plurality of recording elements 26 are divided into a plurality of recording heads 211, and the plurality of recording heads 211 move in the moving direction of the recording medium to be conveyed (the conveyance belt 14 in the state where the recording medium is placed). Images are formed in different recording ranges in the width direction orthogonal to the orbital movement direction) in a plane parallel to the recording medium, and the recording ranges adjacent in the width direction partially overlap in the width direction. The drive data related to the recording operation is set so that the recording operation by the recording element 26 according to a predetermined range from the end in the width direction in the recording range is not performed, and the control unit 50 controls each of the recording heads 211. With respect to, the driving data respectively associated with the driving elements 26 is the positional deviation amount in the width direction of the recording medium obtained based on the movement information for each position in the moving direction (conveying direction) of the recording medium. The correspondence relationship between the drive data and the recording element 26 is changed (shifted) so as to be associated with the recording element 26 at the corresponding position. The predetermined range is set to be equal to or larger than the maximum width (amplitude Wm) of the periodic change of the positional deviation amount.
In this way, by arranging the data for which the recording operation is not performed in the width of the amplitude Wm or more, when the positional deviation within the amplitude Wm occurs, the corresponding nozzle 27 (recording element 26) is shifted by the correspondence relationship. The driving data that does not have any data does not cause the recording operation, that is, the data that causes the recording operation is not lost. Therefore, according to the inkjet recording apparatus 100, the divided drive data divided for each recording head 211 is individually processed, and white streaks due to data loss are not generated. Therefore, it is possible to suppress deterioration of the image quality and more easily. The recording operation can be performed.

Further, in particular, when the same image is formed a plurality of times, the generation of the driving data and the correction related to the meandering are separated, and only the correction related to the meandering is performed immediately based on the detection data of the detection unit 40, It is not necessary to generate and transmit/receive the driving data each having a different meandering phase from the beginning every time, and the processing load can be effectively reduced.

Further, the transport unit 10 has a transport belt 14 on which a recording medium is placed, and the positional deviation amount is obtained based on movement information regarding meandering when the transport belt 14 moves.
As described above, by using the positional deviation of the recording medium caused by the meandering of the conveyor belt 14 by detecting the meandering state of the conveyor belt 14, the amount of positional deviation can be easily identified. In particular, when the edge of the medium is not separated by a definite line such as a cloth, it is difficult to specify the amount of positional deviation of the recording medium itself, and thus the process related to the positional deviation correction is facilitated. ..

The mounting member on which the recording medium is mounted is the endless conveyor belt 14. By transporting the recording medium by using the continuous transport belt 14 as described above, it is possible to stably transport the continuous medium in particular, while the circumferential length of the transport belt 14 becomes long, and the periodic position such as meandering occurs. Misalignment is likely to occur. Therefore, it is possible to easily and continuously perform stable image formation by performing the correction for the positional deviation as needed.

An origin marker O is provided on the conveyor belt 14, and the detection unit 40 (conveyance detector 41) acquires the movement information of the recording medium based on the detection result of the origin marker O.
When the meandering cycle becomes a predetermined fraction of the length of the conveyor belt or the like, particularly when the continuous conveyor belt 14 or the like is apt to cause positional deviation of such a cycle, the position of the origin marker O is used as a reference. By specifying the position in the revolving direction on the conveyor belt 14, it is possible to specify the phase of the periodic positional deviation easily and accurately. As a result, it is possible to easily specify the amount of misregistration according to the phase, quickly perform the correction according to the amount of misregistration, easily suppress the misregistration of the image forming position, and reduce the deterioration of image quality. it can.

Further, the control unit 50, when the drive data corresponding to a part of the recording elements 26 disappears due to the change (shift) in the correspondence relationship between the recording elements 26 (nozzles 27) and the drive data, the control unit 50 The data that does not cause the recording element 26 to perform the recording operation is added as the driving data for the section. Since the driving data for causing the recording operation to be performed by the other recording heads 211 are shifted in the portion where the driving data has been lost, it is possible to simply prevent the recording operation from being performed. It is not necessary to acquire the driving data corresponding to the other recording heads 211, and it is possible to form an image having no recording operation loss by a simple process.

Further, the control unit 50 drives a part of the driving data when there is no printing element 26 corresponding to a part of the driving data due to a change (shift) in the correspondence between the printing element 26 (nozzle 27) and the driving data. Delete the data for use. In other words, it is not necessary to send the data deviating from the driving data of the image forming range of a certain recording head 211 to the driving data of another recording head 211 adjacent in the width direction, and it is sufficient to simply delete the data. Then, since the driving data that deviates from the image forming range in this way is only the data for which the recording operation is not performed as described above, the loss of the image does not occur. Therefore, in the inkjet recording apparatus 100, it is possible to form an appropriate image corresponding to a periodic positional deviation (meandering) with a simple process while reducing deterioration in image quality.

Further, a plurality of memories 253 respectively corresponding to the recording heads 211 are provided, and the driving data is stored in the memories 253 for each range corresponding to the recording range of the recording heads 211 and processed in parallel. As described above, the hardware-separated storage and processing cause problems such as an increase in the processing load of the recording control unit 251 and a limitation on the processing speed due to the limit of the data transfer speed in the inkjet recording apparatus 100. The image data relating to the long line head can be easily and rapidly formed into an image with appropriate image quality without being generated.

The memory 253 is provided on each of the separate substrates 201a to 201h. By completely separating the hardware in this way, it is possible to assemble the recording heads 211 together with the recording heads 211. Therefore, the configuration can be easily obtained flexibly according to the number of the recording heads 211, and the versatility is high. Since the processing is completely independent for each substrate, it is possible to prepare data with a margin before the actual image formation.

Further, the inkjet recording apparatus 100 includes a volatile memory such as a DRAM that stores the meandering information 255 indicating the pattern of the periodic change in the positional deviation amount of the recording medium, and the control unit 50 uses the meandering information 255 to change the movement information. Based on this, the positional deviation amount is acquired.
That is, the positional deviation amount is calculated by storing table data or the like so that the actual positional deviation amount can be obtained according to the movement information (conveying speed etc.) of the recording medium and the positional information of the conveying belt 14. It is possible to suppress an increase in the load that occurs and quickly acquire the amount of positional deviation.

The same meandering information 255 is held for each recording head 211 of each recording operation unit 20 (head unit 21). As a result, it is possible to reliably prevent the deviation of the correction amount between the recording heads 211. In addition, since the meandering information 255 can be easily generated and output to each board 201, no trouble is required.

Further, the control unit 50 has a recording control unit 251 corresponding to each of the recording heads 211, and movement information based on the detection result of the detection unit 40 and the like is input to the recording control unit 251 in synchronization. That is, since it is possible to align the timing of parallel processing of the data corresponding to each of the plurality of recording heads 211, it is possible to easily and appropriately correct the positional deviation related to the meandering without complicating the timing control of the processing. be able to. Therefore, in the inkjet recording apparatus 100, it is possible to prevent distortion and data loss of the raster image of each row, and to stably form an image without distortion and color misregistration continuously.

Further, the detection unit 40 includes an encoder 43 that measures a movement amount (conveyance movement amount) of the conveyance belt 14 in the conveyance direction by the conveyance unit 10. By detecting the rotation amount of the drive roller 11 and the like, the position and the conveyance speed of the recording medium can be accurately acquired in real time. Therefore, the positional deviation amount can be specified at an accurate timing corresponding to the ink ejection timing. Correction can be performed according to the amount of positional deviation. Therefore, the inkjet recording apparatus 100 can more accurately prevent the positional deviation and output a high-quality image with less distortion and color misregistration.

The inkjet recording apparatus 100 also includes a plurality of recording operation units 20. The plurality of recording operation units 20 are arranged at different positions in the moving direction of the conveyed recording medium, and at least a part of them performs a recording operation with a color different from that of the recording operation units 20 other than the part, and a color image is displayed. Output is possible.
As described above, when the head units 21 of a plurality of colors are provided separately at different positions in the transport direction (the rotational movement direction of the transport belt 14) and the recording operation is performed with different colors, the circumferential length of the transport belt 14 is dealt with. However, if there is a positional deviation with a large period equal to or greater than the interval between the plurality of head units 21, positional deviation between colors (color deviation) systematically appears and becomes conspicuous. Therefore, the above correction effectively It is possible to suppress color shift and reduce deterioration of image quality. In particular, the fabric is easily noticeable even with a slight color shift depending on the texture and the like, so that the deterioration of the image quality can be effectively suppressed by a simple process.

Further, the image forming control method according to the present embodiment sets the drive data related to the recording operation so as not to perform the recording operation by the recording element according to the predetermined range from the end in the width direction of the recording range. In each of the setting step and the recording head 211, the drive data associated with the drive element 26 of the recording medium is obtained for each position in the moving direction (conveying direction) of the recording medium based on the movement information. An adjustment step of changing the correspondence between the driving data and the recording elements so as to be associated with the recording elements 26 at positions corresponding to the positional deviation amount in the width direction, and the predetermined range is the positional deviation amount. Is determined to be greater than the maximum width of the cycle change of.
By including such an image formation control method, when a long image is formed by a line head in which a plurality of recording heads 211 are arranged, the drive data is appropriately divided according to the recording heads 211, It is possible to process efficiently while suppressing the decrease.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above-described embodiment, the substrate 201 is provided for each recording head 211 and the driving data is stored and processed separately. However, in a head module provided with a plurality of recording heads 211, When the arrangement range of the nozzles 27 in the plurality of recording heads 211 is integrally determined (when a single recording range is determined), for example, the nozzles of the two recording heads 211 are alternately arranged in the width direction. If the head module is used as a unit (element group), the driving data may be stored and processed.

Further, the conveyance detection unit 41 may detect not only the origin mark O but also the position in the width direction of the reference line in the conveyance direction of the conveyance belt 14. By obtaining this position, it is possible to measure the positional deviation amount of the conveyor belt 14 in the width direction in real time. Information on the amount of positional deviation is sent to each recording control unit 251, and each recording control unit 251 specifies the amount of positional deviation of the recording medium that is assumed at a predetermined timing, and shifts the image data according to the amount of positional deviation. .. When the positional deviation amount of the recording medium is directly or indirectly obtained in real time, the meandering information 255 may not be used.

Further, in the above-described embodiment, the signal of the encoder 43 is acquired and the accurate transport speed is specified. However, in comparison with the magnitude of the change in the positional deviation amount per time depending on the meandering cycle and the amplitude of the transport belt 14. When the change in the conveyance speed is sufficiently small, the value of the encoder 43 is not necessarily acquired, the conveyance speed is fixed, and the detection result of the conveyance detection unit 41 periodically (eg, about one cycle of the conveyance belt 14). Alternatively, the phase shift amount may be corrected.

Further, in the above embodiment, the description has been made assuming that only the meandering of a single cycle exists, but the meandering of a plurality of cycles may overlap. When the ratio of a plurality of cycles is an integer or the like, the meandering information 63 and 255 may be generated based on a long cycle, and when the ratio is a non-integer multiple, the meandering information may be separately generated and added. .. That is, the total amount of change in which the individual periodic changes are combined does not have to be completely periodically repeated.

Further, in the above-described embodiment, the memory 253 and the recording control unit 251a are shown as being completely separated in terms of hardware in each board, but they are not necessarily completely separated in terms of hardware. Data related to the plurality of recording heads 211 may be stored and processed on one substrate. Even if they are divided by hardware, they may not be provided on different substrates 201. Even in these cases, it is possible to more easily perform the recording operation while suppressing the deterioration of the image quality without complicating the processing of the data related to the overlapping range D of the adjacent recording heads 211.

Further, in the above-described embodiment, the same meandering information 255 is stored on the different substrates 201a to 201h, but if the phases are different depending on the position difference in the transport direction of the recording heads arranged in a staggered pattern. The twisted meandering information 255 may be stored. Further, between the substrates 201 related to different head units 21, the meandering information 255 having different phases may be stored according to the position in the transport direction.

In the above embodiment, the endless conveyor belt 14 is used. However, the mounting member on which the recording medium is mounted does not have to be endless, and may be one provided intermittently. , It may be other things that can cause meandering. In addition, the recording medium may be meandered by a slight change in the conveying direction for each feeding operation of the recording medium by a plurality of rollers. In addition, the cause and the range of occurrence of the meandering are not limited as long as the pattern is such that the cyclic positional displacement amount in the width direction in the range facing the ink landing position from the head unit 21 can be specified (estimated) in advance. ..

Further, in the above-described embodiment, the signals from the conveyance detection unit 41 and the encoder 43 are sent to the recording control unit 251 synchronously via the signal line that cascade-connects the substrates 201. If possible, they do not have to be cascaded.

In addition, in the above-described embodiment, the inkjet recording apparatus 100, which has the plurality of head units 21 at different positions in the transport direction (the circulating movement direction of the transport belt 14) and discharges inks of different colors, has been described. Alternatively, only a single color of ink may be ejected from the plurality of head units 21. In this case, for example, when the recording medium is a paper medium or the like, even a slight displacement or image distortion in a monochrome image, particularly a clear outline such as a character or a diagram, is easily noticeable. The distortion can be effectively suppressed and the deterioration of the image quality can be easily reduced.

Further, in the above-described embodiment, the inkjet recording apparatus provided with a large number of sets of the nozzles 27 and the electromechanical conversion elements 252 corresponding to the nozzles 27 has been described as an example. If the line head structure is divided into the recording heads (head module, element group) and arranged such that the arrangement range (recording range) of the recording elements in each element group partially overlaps, Not limited. For example, it may be an LED printer using an LED element.
In addition, the specific details such as the specific configuration, structure, processing content, and processing procedure shown in the above embodiment can be appropriately changed without departing from the spirit of the present invention.

10 Transport Unit 11 Drive Roller 12 Transport Drive Unit 14 Transport Belt 20 Recording Operation Unit 201, 201a to 201h Substrate 21 Head Unit 211, 211a to 211h Recording Head 22 Carriage 23 Carriage Lifting Unit 232 Lifting Motor 233 Electromagnetic Brake 234 Beam Member 235 Support Part 24 Carriage drive part 25 Head drive parts 251, 251a Recording control part 252 Electromechanical conversion element 253 Memory 254 Discharge defective nozzle list 255 Meandering information 26 Recording elements 27, 27f1, 27f2, 27c1, 27c2 Nozzle 27a Nozzle opening 30 Ink supply part 31 ink storage tank 32 rack 40 detection unit 41 transport detection unit 42 image detection unit 43 encoder 50 control unit 51 CPU
52 RAM
60 storage unit 61 program 62 ejection failure nozzle list 63 meandering information 64 distribution setting 65 job data 70 communication unit 81 display unit 82 operation reception unit 90 bus 100 inkjet recording device L meandering cycle M recording medium O origin marker Wm amplitude

Claims (14)

A transport unit for transporting the recording medium,
An acquisition unit that acquires movement information of the recording medium being conveyed,
A recording operation unit having a plurality of recording elements for performing a recording operation,
A control unit,
Equipped with
The plurality of recording elements are divided into a plurality of element groups, one by one,
The plurality of element groups form images in different recording ranges in a width direction orthogonal to a moving direction of the conveyed recording medium in a plane parallel to the recording medium,
The recording ranges adjacent to each other in the width direction partially overlap in the width direction,
The drive data related to the recording operation is set so that the recording operation by the recording element according to a predetermined range from the end in the width direction in the recording range is not performed,
The control unit, for each of the element group, the set drive data associated with the drive element is obtained based on the movement information for each position in the movement direction, the recording. The correspondence between the drive data and the recording element is changed so as to be associated with the recording element at a position corresponding to the amount of positional deviation in the width direction of the medium,
The image forming apparatus is characterized in that the predetermined range is set to be equal to or larger than a maximum width of the periodic change of the positional deviation amount. The transport section has a mounting member for mounting the recording medium,
The image forming apparatus according to claim 1, wherein the positional deviation amount is obtained based on the movement information related to meandering during movement of the mounting member. The image forming apparatus according to claim 2, wherein the placing member is an endless belt. An index indicating a reference position is provided on the placement member,
The image forming apparatus according to claim 2, wherein the acquisition unit acquires movement information of the recording medium based on a detection result of the index. When there is no driving data corresponding to some of the recording elements due to the change in the correspondence, the control unit causes the recording element to perform a recording operation as driving data corresponding to the some recording element. The image forming apparatus according to any one of claims 1 to 4, wherein non-existent data is added. 6. The control unit deletes a part of the drive data when there is no recording element corresponding to the drive data due to the change in the correspondence relationship. The image forming apparatus according to item 1. A plurality of first storage units respectively corresponding to the element groups,
7. The driving data is stored in each of the plurality of first storage units for each range corresponding to a recording range of the element group, and is processed in parallel. The image forming apparatus according to item 1. The image forming apparatus according to claim 7, wherein the first storage unit is provided on a separate substrate. A second storage unit that stores reference data indicating a pattern of the periodic change in the positional deviation amount;
The image forming apparatus according to any one of claims 1 to 8, wherein the control unit acquires the positional deviation amount based on the movement information using the reference data. 10. The image forming apparatus according to claim 9, wherein the same reference data is held corresponding to each of the element groups of the recording operation unit. The control unit has an individual control unit corresponding to each of the element groups,
The image forming apparatus according to claim 1, wherein the movement information is synchronously input to the individual control unit. The image forming apparatus according to claim 1, wherein the acquisition unit includes an encoder that measures a transport movement amount of the transport unit. A plurality of the recording operation units,
The plurality of recording operation units are arranged at different positions in the moving direction of the conveyed recording medium, and at least a part performs a recording operation in a color different from that of the recording operation units other than the part. The image forming apparatus according to any one of claims 1 to 12. A transport unit that transports a recording medium, an acquisition unit that acquires movement information of the transported recording medium, and a recording operation unit that has a plurality of recording elements that perform a recording operation, and the plurality of recording elements, Each of the plurality of element groups is divided into a plurality of element groups, and the plurality of element groups form images in different recording ranges in a width direction orthogonal to a moving direction of the conveyed recording medium in a plane parallel to the recording medium. In the image forming control method of the image forming apparatus, the recording ranges adjacent to each other in the width direction are partially overlapped in the width direction.
An initial setting step of setting the drive data related to the recording operation so that the recording operation by the recording element according to a predetermined range from the end in the width direction in the recording range is not performed,
For each of the element groups, the set driving data associated with each of the driving elements is obtained based on the movement information for each position in the movement direction, and the width direction of the recording medium. Adjustment step for changing the correspondence between the drive data and the recording element so that the recording element is associated with the recording element at a position corresponding to the positional deviation amount of
Including
The image forming control method is characterized in that the predetermined range is set to be equal to or larger than a maximum width of the periodic change of the positional deviation amount.

Images