JP4867508B2 - Droplet ejection apparatus and droplet ejection program - Google Patents

Description

  The present invention relates to a droplet discharge device and a droplet discharge program, and in particular, a plurality of droplets in which a plurality of nozzles are arranged two-dimensionally and each discharge a colored ink liquid or a treatment liquid that aggregates the ink liquid. The present invention relates to a droplet discharge device provided with discharge means and a droplet discharge program executed by the droplet discharge device.

  2. Description of the Related Art Conventionally, an ink jet printer or the like that has a plurality of recording heads each having a plurality of nozzles and records an image by discharging a colored ink liquid or a treatment liquid that agglomerates the ink liquid from each nozzle of each recording head to a recording medium A droplet discharge device is known.

  In this type of liquid droplet ejection device, streaks and shading unevenness occur in the recorded image when non-ejection nozzles that cannot eject liquid droplets to the recording head or defective nozzles that cannot eject liquid droplets of an appropriate droplet amount occur. As a result, the image quality is significantly reduced. Such streaks and shading unevenness are generally called banding, streak, or the like.

  Therefore, as a technique for suppressing a reduction in image quality due to the occurrence of non-ejection nozzles or defective nozzles, Patent Document 1 deals with abnormal nozzles for which deterioration in ejection state has been determined among a plurality of nozzles of a recording head. A technique has been disclosed in which the recording liquid to be printed and the treatment liquid is not landed on the vicinity of the recording dots so that the ink dots in the vicinity of the streaks and the light and shade unevenness are blotted to make the streaks and the light and dark unevenness inconspicuous.

By the way, in this type of droplet discharge device, as shown in FIG. 8, as an example, a plurality of nozzles 40 ′ are arranged in the relative movement direction of the nozzles and the recording paper to be image-recorded. The plurality of nozzle rows 49 ′ do not overlap with the nozzle rows 49 ′ in which the nozzle rows 49 ′ are adjacent to each other in the movement direction, and all the nozzles 40 ′ are substantially equal in the direction perpendicular to the movement direction. Some of the columns 49 ′ include a recording head 14 ′ provided so as to have a predetermined angle with respect to the moving direction.
Japanese Patent No. 3472250

  However, in this recording head 14 ′, there is a case where variations in the amount of droplets ejected from each nozzle 40 ′ occur due to a manufacturing error or the like. In this case, periodic banding is performed on the recorded image. May occur.

  That is, even if the same drive signal is supplied to each nozzle 40 ′, due to manufacturing errors and the like, from one nozzle side 40 ′ on one end side of each nozzle row 49 ′ to the nozzle 40 ′ on the other end side. When the amount of droplets discharged gradually decreases, as an example, as shown in FIG. 8, the amount of droplets discharged from each nozzle 40 ′ is small in each nozzle row 49 ′. Therefore, banding occurs at a position corresponding to the position between the nozzle rows 49 ′ of the recorded image.

  Thus, as shown in FIG. 8 as an example, in the recording head 14 ′ in which a plurality of nozzles 40 ′ are provided two-dimensionally in the relative moving direction of the recording paper and in the direction orthogonal to the moving direction, the nozzle 40 ′. When variations occur in the amount of droplets ejected from the nozzles 40 ′ according to the positions of the nozzles, banding occurs at positions corresponding to the positions between the nozzle rows 49 ′ in the recorded image. There has been a problem of lowering.

  Note that the technique of Patent Document 1 is a technique for reducing deterioration in image quality when a non-ejection nozzle or a defective nozzle occurs in a recording head. In a recording head in which nozzles are provided two-dimensionally, This is ineffective when there is a variation in the amount of droplets ejected from each nozzle according to the position.

  The present invention has been made in view of the above problems, and in a droplet discharge means in which nozzles are provided in a two-dimensional manner, the amount of ink liquid discharged from each nozzle varies depending on the position of the nozzle. It is an object of the present invention to provide a droplet discharge device and a droplet discharge program that can suppress a decrease in image quality of a recorded image even if it occurs.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a plurality of nozzle rows in which a plurality of nozzles are arranged in the relative movement direction of the nozzle and the recording paper to be image-recorded. Rows do not overlap with adjacent nozzle rows in the moving direction, all nozzles are substantially equally spaced in the direction perpendicular to the moving direction, and each nozzle row has a predetermined angle with respect to the moving direction. A plurality of liquid droplet ejection means for ejecting a colored ink liquid or a treatment liquid for aggregating the ink liquid from the nozzles to the recording paper that moves relatively in the movement direction, and the ink Of the nozzles provided in the droplet discharge means for discharging the liquid, the first nozzle and the last nozzle in the moving direction of the nozzle rows adjacent to each other in the orthogonal direction of the nozzle rows adjacent to each other The area provided in the droplet discharge means for discharging the processing liquid to the area where the ink liquid discharged from the nozzle located within a predetermined distance with respect to the orthogonal direction adheres to the recording paper In addition, control is performed so that the droplet amount of the processing liquid discharged from the nozzle that discharges the processing liquid is smaller than the droplet amount of the processing liquid discharged from the other nozzles of the droplet discharge unit , and the ink liquid In the region where the ink adheres to the recording paper, the liquid droplet ejection that ejects the processing liquid as it moves away from the position where the ink liquid ejected from the head nozzle and the tail nozzle adheres in the orthogonal direction. control means for droplet amount of the processing liquid ejected from the nozzles for ejecting the processing liquid to the area provided in the device is controlled to be close to the droplet amount of the processing liquid discharged from the other nozzles , And a.

According to the first aspect of the present invention, a plurality of nozzle rows in which a plurality of nozzles are arranged with respect to the relative movement direction of the nozzles and the recording paper to be image-recorded are moved with the nozzle rows adjacent to each nozzle row. The nozzles are not overlapped with each other, all the nozzles are substantially equally spaced with respect to the direction perpendicular to the moving direction, and each nozzle row is provided at a predetermined angle with respect to the moving direction. The colored ink liquid or the treatment liquid that agglomerates the ink liquid is ejected to the recording paper that moves relative to the movement direction from each nozzle. Here, “substantially equal intervals” means equal intervals in a range including various errors such as errors in manufacturing droplet discharge means and errors caused by changes in environmental conditions.

In the present invention, among the nozzles provided in the droplet discharge means for discharging the ink liquid by the control means, the heads in the moving direction of the nozzle rows adjacent to each other in the orthogonal direction to the nozzle rows adjacent to each other Are provided in a droplet discharge means for discharging a processing liquid to a region where ink liquid discharged from a nozzle located within a predetermined distance from the nozzles at the end and the nozzle at the end adheres to the recording paper. In addition, the droplet volume of the processing liquid discharged from the nozzle that discharges the processing liquid to the region is controlled to be smaller than the droplet volume of the processing liquid discharged from the other nozzles of the droplet discharge means. The predetermined distance defines a range in which the ink liquid is allowed to spread in order to reduce the processing liquid and make the banding inconspicuous. The predetermined distance can be determined appropriately by, for example, performing an evaluation experiment on the image quality of the recorded image by changing the range in which the treatment liquid is reduced.

As described above, according to the first aspect of the present invention, among the nozzles provided in the droplet discharge means for discharging the colored ink liquid, the nozzle rows adjacent to each other in the direction orthogonal to the relative movement direction of the recording paper. On the other hand, with respect to a region where ink liquid ejected from a nozzle located within a predetermined distance from the first nozzle and the last nozzle in the moving direction of nozzle rows adjacent to each other adheres to the recording sheet . The droplet volume of the treatment liquid discharged from the nozzle provided in the droplet discharge means for discharging the treatment liquid for aggregating the ink liquid is larger than the droplet volume of the treatment liquid discharged from the other nozzle of the droplet discharge means. since the less, the ink liquid adhering to the region of the recording paper becomes less noticeable banding in more bleeding, droplets of ink ejected from the nozzles according to the position of the nozzle Even when variation occurs, it is possible to suppress deterioration in the image quality of the recorded image.

In addition, the control means according to the present invention, as described in claim 2, further reduces the treatment liquid to a concentration area where the average density of an image recorded in the area where the ink liquid adheres to the recording paper is more conspicuous. Control may be performed so that the reduction amount of the treatment liquid ejected to the region is larger than the nozzle provided in the droplet ejection means for ejecting.

According to a third aspect of the present invention, the control means of the present invention provides the liquid droplet ejection means for ejecting the treatment liquid as the degree of penetration of the ink liquid adhering to the recording paper into the recording paper decreases. You may control so that the reduction amount of the droplet of the process liquid discharged with respect to the area | region where the said ink liquid adheres to the said recording paper from the provided nozzle may be enlarged.

Furthermore, as described in claim 4 , the present invention further includes drive signal generation means for generating a drive signal to be discharged from each nozzle of the plurality of droplet discharge means, wherein the plurality of droplet discharge means is The ink liquid or the processing liquid is ejected from each nozzle to the recording paper in a droplet amount corresponding to the driving signal supplied corresponding to each nozzle from the driving signal generating means, and the control means The amount of treatment liquid ejected from a nozzle provided in the droplet ejection means for ejecting the treatment liquid may be controlled by controlling the drive signal generation means.

On the other hand, in order to achieve the above object, the droplet discharge program according to claim 5 is a plurality of nozzle rows in which a plurality of nozzles are arranged in the relative movement direction between the nozzles and the recording paper to be image-recorded. However, each nozzle row does not overlap the adjacent nozzle row with respect to the moving direction, and all nozzles are substantially equal to each other in a direction orthogonal to the moving direction, and each nozzle row has a predetermined angle with respect to the moving direction. A plurality of droplet discharge means for discharging a colored ink liquid or a treatment liquid for aggregating the ink liquid to a recording sheet that moves relative to the moving direction from each nozzle. A droplet discharge program executed in a provided droplet discharge apparatus, wherein the nozzle rows adjacent to each other among nozzles provided in the droplet discharge means for discharging the ink liquid are orthogonal to each other In the region where the ink liquid ejected from the nozzles located within a predetermined distance from the head nozzle and the tail nozzle in the moving direction of the nozzle rows adjacent to each other on the recording sheet adheres to the recording paper On the other hand, the amount of the treatment liquid ejected from the nozzle that ejects the treatment liquid to the region provided in the droplet ejection means that ejects the treatment liquid is ejected from another nozzle of the droplet ejection means. In the region where the ink liquid adheres to the recording paper, the position where the ink liquid ejected from the leading nozzle and the trailing nozzle adheres is controlled so as to be less than the droplet amount of the processing liquid to be applied The amount of the treatment liquid discharged from the nozzle that discharges the processing liquid to the region provided in the droplet discharge means that discharges the processing liquid as the distance from the orthogonal direction increases. It is intended to execute the control step of controlling to be close to the drop amount of the processing liquid discharged from the other nozzles in the computer.

  Therefore, according to the droplet discharge program of the sixth aspect, the computer can be caused to act in the same manner as the first aspect of the invention, and therefore, according to the position of the nozzle as in the first aspect of the invention. Therefore, even when there is a variation in the amount of ink liquid ejected from each nozzle, it is possible to suppress a decrease in the image quality of the recorded image.

As described above, according to the present invention, among the nozzles provided in the droplet discharge means for discharging the colored ink liquid, the nozzle rows adjacent to each other in the direction perpendicular to the relative movement direction of the recording paper. With respect to a region where ink liquid ejected from nozzles located within a predetermined distance from the head nozzle and tail nozzle in the moving direction of the nozzle rows adjacent to each other adheres to the recording paper , The droplet volume of the treatment liquid ejected from the nozzle provided in the droplet ejection means for ejecting the treatment liquid for aggregating the ink liquid is larger than the droplet volume of the treatment liquid ejected from the other nozzles of the droplet ejection means. Therefore, even if there is a variation in the amount of ink droplets ejected from each nozzle according to the position of the nozzle, it is possible to suppress a decrease in the image quality of the recorded image. , It has an excellent effect that.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a case where the present invention is applied to an inkjet printer will be described.

  FIG. 1 shows the overall configuration of an ink jet printer (hereinafter referred to as “printer”) 10 according to the present embodiment.

  The printer 10 includes a recording head array 12 that records an image by ejecting ink droplets. The recording head array 12 includes five recording heads 14C, 14M, 14C, 14M, 14C, 14M, 14C, 14M, and 14C corresponding to the ink liquids of C (cyan), M (magenta), Y (yellow), and K (black), respectively. 14Y, 14K, 14H. In the following description, an initial letter corresponding to the reference numeral is added when distinguishing each color of ink liquid and the treatment liquid, and an initial letter corresponding to each color is omitted unless otherwise distinguished.

  The treatment liquid is a colorless or light-colored ink liquid containing a polyvalent metal or the like, and has the effect of reducing dot bleeding by aggregating the pigments of the CMYK color inks. By dripping the treatment liquid over each color ink, dot bleeding is reduced and the image quality can be improved.

  Each recording head 14 is a long head having a recording area equal to or larger than the width of the recording paper P, and a large number of nozzles 40 (see FIG. 3) are two-dimensionally arranged along the width direction of the recording paper P. . The recording head 14 can collectively record the entire width of the recording paper P by ejecting ink droplets from the nozzles 40.

  The printer 10 is loaded with ink cartridges 16C, 16M, 16Y, 16K, and 16H respectively storing CMYK ink liquids and processing liquids. The ink liquids and processing liquids stored in the ink cartridges 16 are illustrated in the drawing. The recording heads 14 are supplied to the corresponding recording heads 14 through the pipes that are not connected.

  In the vicinity of the recording head array 12, a maintenance unit 15 that performs cleaning for preventing ink clogging of each recording head 14 and a suction recovery operation when ink clogging occurs corresponds to each recording head 14. Is provided.

  The maintenance unit 15 is positioned on both sides of the recording head array 12 as shown in FIG. 1 during image recording, and moves to a position facing each nozzle of the recording head array 12 as shown in FIG. 2 during maintenance. It is configured as follows. Note that the configuration of the maintenance unit 15 is not limited to this, and any configuration may be used as long as it can be disposed so as to be able to face each nozzle of the recording head array 12 during maintenance.

  The printer 10 also includes a paper feed tray 18 that stores the recording paper P. The recording paper P supplied from the paper supply tray 18 is conveyed by a plurality of roller pairs 20 and supplied to the recording head array 12.

  An endless transport belt 24 wound around rollers 22A and 22B and a tension roller 23 is provided at a position facing the recording head array 12. The conveying belt 24 has a surface wider than the width in the direction orthogonal to the conveying direction of the recording paper P, and is given a certain tension by being pulled downward by the tension roller 23. The conveyor belt 24 is driven to rotate by the rotation of the rollers 22A and 22B and the tension roller 23.

  A charging roll 26 is provided at a position facing the roller 22B, and a predetermined voltage is applied to the charging roll 26. The recording paper P transported by the plurality of roller pairs 20 is charged by being sandwiched between the charging roll 26 and the transport belt 24, is adsorbed on the surface of the transport belt 24, and is driven by the rotation of the transport belt 24. It passes through an image recording area facing the recording head array 12.

  When the recording paper P passes through the image recording area, the printer 10 ejects ink droplets and processing liquid from each nozzle of each recording head 14 based on the image data, thereby recording a full-color image on the recording paper P. The

  A plurality of discharge rollers 30 are provided on the downstream side of the conveyance belt 24 in the conveyance direction of the recording paper P. The recording sheet P on which an image is recorded by the recording head array 12 is conveyed by the plurality of discharge rollers 30 and discharged to the discharge tray 32.

  The printer 10 also has a reverse path 33 for double-sided recording. The reversing path 33 is composed of a plurality of roller pairs 35, and the recording paper P on which an image is recorded on one side by the recording head array 12 is reversed by the reversing path 33 and conveyed to the image recording area again. As a result, it is possible to record images on both sides of the recording paper P.

  FIG. 3 is a detailed plan view of the recording head 14 according to the present embodiment.

  As shown in the figure, the recording head 14 includes a plurality of nozzles 40 arranged in the relative movement direction (here, the conveyance direction) between the nozzles 40 and the recording paper P to be image-recorded. The nozzle rows 49 of each nozzle row 49 do not overlap the moving direction with the nozzle rows 49 adjacent to each other, and all the nozzles 40 are substantially equal to each other in the direction orthogonal to the moving direction. The resolution is increased by substantially reducing the interval between the nozzles 40 in the orthogonal direction. In the present embodiment, it is assumed that each nozzle row 49 includes 32 nozzles 40, for example.

  FIG. 4 shows a cross-sectional view of one nozzle portion of the plurality of nozzles 40 provided in the recording head 14 according to the present embodiment.

  As shown in the figure, the recording head 14 includes a nozzle 40, an ink tank 41, a supply path 44, a pressure chamber 46, and a piezoelectric element 48.

  The ink tank 41 is supplied with a drop amount of ink from the color ink cartridge 16 corresponding to each recording head 14 and temporarily stores the ink. The ink tank 41 communicates with the pressure chamber 46 via the supply path 44, and the pressure chamber 46 communicates with the outside via the nozzle 40.

  A part of the wall surface of the pressure chamber 46 is constituted by a pressure adjustment plate 46A, and a piezoelectric element 48 is attached to the pressure adjustment plate 46A.

  The piezoelectric element 48 is deformed in accordance with a drive waveform of a drive signal supplied from a head control unit 64 (see FIG. 5), which will be described later, and changes the pressing force on the pressure adjusting plate 46A, thereby causing the pressure chamber 46 to have a volume. A change (shrinkage or expansion) is generated. That is, in the recording head 14, the ink liquid stored in the ink tank 41 by the vibration wave (pressure wave) of the ink liquid generated by the volume change of the pressure chamber 46 is supplied from the nozzle 40 via the supply path 44 and the pressure chamber 46. It is supposed to be discharged.

  The recording head 14 processes, for example, a large plate-shaped piezoelectric element in accordance with the position of the pressure chamber 46 by a known processing method such as a dicing method or a blast method, and the processed plate-shaped piezoelectric element is processed in the pressure chamber 46. It can be produced by bonding in accordance with the position of the above, or by forming a piezoelectric element by a known film formation method (for example, vapor phase film formation method).

  However, the recording head 14 has a nozzle 40 due to, for example, a manufacturing error such as a processing error of a plate-like piezoelectric element, an error in a bonding position when the piezoelectric element is bonded, or an error in film formation of the piezoelectric element. Depending on the position, variations in the amount of droplets ejected from each nozzle 40 may occur.

  On the other hand, FIG. 5 shows an electrical configuration of the printer 10 according to the present embodiment.

  As shown in the figure, the printer 10 includes a CPU (Central Processing Unit) 50 that controls the overall operation, a ROM 52 in which various programs including various control programs for controlling the entire apparatus, various data, and the like, A RAM 54 that temporarily stores data and the like, a communication interface 56 that is connected to an external terminal via a network (not shown), receives image data to be recorded on the recording paper P from the external terminal, and receives the received image data in CMYK colors. A data conversion unit 58 that converts the image data into a predetermined number of gradations for each dot constituting the pixel by performing image processing such as halftone processing on the CMYK color image data converted by the data conversion unit 58 An image processing unit 60 for generating dot data for each of the CMYK colors.

  The data conversion unit 58 stores a color correction LUT (lookup table), converts image data into CMYK color image data, and performs color correction and density correction according to the properties of the ink. Perform color correction processing.

  Further, the image processing unit 60 can record with relatively high gradation image data such as 256 gradations by the recording head 14 using a halftone processing method such as dithering or error diffusion method. Create dot data for the number of gradations. In general, the number of gradations that can be recorded by an inkjet printer is generally 2 to 8 gradations. However, in this embodiment, as an example, each of the colors of YMCK has 4 gradations (no drops, small drops, medium drops, And large droplets).

  On the other hand, the printer 10 converts the dot data for each CMYK color created by the image processing unit 60 into a data structure that can be decoded by the head control unit 64 described later, and each of the recording heads 14C, 14M, 14Y, and 14K. A recording data creation unit 62 for creating recording data for each CMYK color in which data is rearranged in a recording order (transfer order) considering the arrangement of the nozzles 40, and driving of each recording head 14 based on each created recording data A head control unit 64 that controls the conveyance of the recording paper P by controlling a motor (not shown) that rotationally drives each of the roller pairs 20, the discharge rollers 30, the rollers 22A and 22B, and the like. It has more.

  The recording data creation unit 62 performs processing liquid (H) recording data for discharging the processing liquid from each nozzle 40 of the recording head 14H under the control of the CPU 50 in addition to the creation of recording data for each CMYK color. Create

  In addition, the head control unit 64 is electrically connected to each piezoelectric element 48 provided in each recording head 14 individually by wiring, and switches for individually controlling on / off of energization for each wiring. Built-in circuit. The head control unit 64 includes an amplifier capable of adjusting the gain amount, and amplifies a voltage supplied from a power source (not shown). The head controller 64 uses the voltage amplified by the amplifier to control on / off of energization by the switch circuit based on the recording data, so that the size of the dots to be recorded (small droplet, medium droplet, large droplet) ) In accordance with (), a drive signal having a predetermined drive waveform is generated and supplied to the piezoelectric element 48, and the amplitude of the drive waveform of the supplied drive signal is changed by changing the gain amount of the built-in amplifier. Is adjustable.

  The CPU 50, ROM 52, RAM 54, communication interface 56, data conversion unit 58, image processing unit 60, recording data creation unit 62, head control unit 64, and transport control unit 66 are connected to each other via a system bus BUS. ing. Accordingly, the CPU 50 controls the access to the ROM 52 and the RAM 54, the control of the data transmission / reception with the external terminal by controlling the communication interface 56, and the data processing by the data conversion unit 58, the image processing unit 60, and the recording data creation unit 62. Control of the amplitude of the drive waveform of the drive signal by controlling the gain amount of the amplifier built in the head control unit 64, control of conveyance of the recording paper P by controlling the conveyance control unit 66, Can be performed respectively.

  By the way, as described above, banding may occur in the recording head 14 at a position corresponding to the position between the nozzle rows 49 of the image to be recorded due to a manufacturing error or the like.

  Therefore, in the present embodiment, the information indicating the position of the data corresponding to the first nozzle 40A and the last nozzle 40B of each nozzle row 49 in the print data is described above as the nozzle row position information indicating the position of the nozzle row 49. Stored in the ROM 52 in advance.

  Next, the operation of the printer 10 when image data is input from an external terminal (not shown) via the communication interface 56 will be described with reference to FIG. FIG. 6 is a flowchart showing the flow of an image recording processing program executed by the CPU 50 when image data is input from an external terminal (not shown). The program is stored in advance in a predetermined area of the ROM 52.

  In step 100 of the figure, the image data received via the communication interface 56 is stored in the RAM 54, and in the next step 102, the data conversion unit 58 is instructed to convert the data.

  The data converter 58 reads the image data stored in the RAM 54, converts the image data into CMYK color image data, and uses the color correction LUT to perform color correction and density according to the properties of each color ink. Perform color correction such as correction. Then, the data conversion unit 58 stores the image data after the color correction processing in a storage area different from the image data received via the communication interface 56 of the RAM 54.

  In the next step 104, the image processing unit 60 is instructed to execute image processing.

  In response to this, the image processing unit 60 reads the image data after conversion by the data conversion unit 58 from the RAM 54, performs halftone processing based on the image data, and performs each dot according to the gradation value of each pixel. In addition, dot data for each of four gradations of CMYK colors is created. The image processing unit 60 stores the created dot data for each CMYK color in a predetermined storage area of the RAM 54.

  In the next step 106, the recording data creation unit 62 is instructed to create recording data for each CMYK color.

  In response to this, the recording data creation unit 62 reads the dot data for each CMYK color stored in the RAM 54, converts the dot data for each CMYK color into a data structure that can be read by the head control unit 64, and records each recording data. Recording data for each CMYK color is generated by rearranging the data in the recording order in consideration of the arrangement of the nozzles 40 of the heads 14C, 14M, 14Y, and 14K. Then, the recording data creation unit 62 stores the created recording data for each CMYK color in a predetermined storage area of the RAM 54.

  In the next step 108, the nozzle row position information stored in the ROM 52 is read, and the print data creation unit 62 is instructed to create print data for the treatment liquid based on the nozzle row position information.

  In response to this, the recording data creation unit 62, based on the recording data for each CMYK color created in step 106 and the nozzle row position information group, the first nozzle in each nozzle row 49 of the recording heads 14C, 14M, 14Y, 14K. The amount of processing liquid from a nozzle within a predetermined distance (for example, within the range of two nozzles) from 40A and the last nozzle 40B is controlled to be smaller than the amount of processing liquid from other nozzles. The method is based on the recording data for each CMYK color and the nozzle row position information, and a standard amount (in this case, a medium droplet) of processing liquid and the recording head 14C with respect to the position where the ink droplets of each color of CMYK adhere to the recording paper P. , 14M, 14Y, 14K nozzles of the recording head 14H corresponding to the nozzles 40 within a predetermined distance (for example, within the range of two nozzles) with respect to the orthogonal direction from the first nozzle 40A and the last nozzle 40B of the nozzle row 49. Recording data for processing liquid (H) for discharging a processing liquid having a droplet amount (here, small droplets) smaller than the standard amount from 40 is created. Then, the recording data creation unit 62 stores the created recording data for the treatment liquid in a predetermined storage area of the RAM 54 together with the recording data for each CMYK color.

  In the next step 110, the conveyance control unit 66 is instructed to start conveyance of the recording paper P, and when the recording paper P reaches the image recording area facing the recording head array 12, the process proceeds to the next step 112.

  The transport control unit 66 controls a motor (not shown) to start transporting the recording paper P stored in the paper feed tray 18. The recording paper P is conveyed by the plurality of roller pairs 20 and the conveying belt 24 and passes through the image recording area.

  In the next step 112, according to the positional relationship of each recording head 14 with respect to the transport direction in which the recording paper P is transported, each print data for one line of YMCKH stored in the storage area of the RAM 54 is transferred to the head controller. Output to 64.

  The head controller 64 sequentially supplies drive signals to the piezoelectric elements 48 corresponding to the nozzles 40 of the recording heads 14 based on the input recording data of YMCKH. As a result, droplets are ejected from the nozzles 40 of the recording heads 14 and an image for one line is recorded on the recording paper P.

In the next step 114 , it is determined whether or not the recording of all the lines of the recording data has been completed. If the determination is negative, the process returns to step 112 and the recording of the image for the next one line is continuously executed. If the determination is affirmative, the processing of the image recording processing program ends.

  The recording sheet P on which an image is recorded is conveyed by a plurality of discharge rollers 30 and discharged to a discharge tray 32.

  Here, FIG. 7A shows an example in which the printer 10 according to the present embodiment records an image of which all pixels have the same gradation on the recording paper P. Even if the recording head 14 supplies the same drive signal to each nozzle 40, the nozzle 40 B on the other end side from the nozzle 40 A on the one end side of each nozzle row 49 due to a manufacturing error or the like. It is supposed that the amount of droplets ejected gradually becomes smaller. In FIG. 7A, a nozzle number for identifying the nozzle 40 in each nozzle row 49 is attached to the nozzle 40.

  FIG. 7B also shows the amount of treatment liquid droplets ejected from the nozzles 40 of each nozzle row 49 of the recording head 14H for each nozzle number.

  As shown in FIG. 7A, the image recorded on the recording paper P is ejected to a position corresponding to the position between the nozzle arrays 49 of the recording head 14 by the processing of the image recording processing program. Since the droplet volume of the processing liquid is reduced, the dots recorded by the colored ink droplets at the position are likely to spread, and the banding becomes inconspicuous.

As described above, according to the present embodiment, a plurality of droplet discharge means (here, each recording head 14) are provided with a plurality of relative movement directions of the nozzle and the recording sheet to be image-recorded. A plurality of nozzle rows in which nozzles are arranged do not overlap each other in the moving direction with each nozzle row, and all nozzles move at approximately equal intervals in the direction orthogonal to the moving direction, and each nozzle row moves. The recording liquid is provided at a predetermined angle with respect to the direction, and the recording liquid that moves the colored ink liquid or the liquid for aggregating the ink liquid from each droplet discharge means relative to the moving direction from each nozzle. The nozzles provided in the droplet discharge means (here, the recording heads 14C, 14M, 14Y, and 14K) for discharging the ink liquid by the control means (here, the CPU 50). Of these, ink ejected from a pair of nozzles (here, nozzle 40A and nozzle 40B) adjacent to each other in the orthogonal direction of the nozzle rows adjacent to each other, from nozzles positioned within a predetermined distance in the orthogonal direction The droplet amount of the treatment liquid ejected from the nozzles provided in the liquid droplet ejection means (here, the recording head 14H) that ejects the treatment liquid to the area where the liquid adheres to the recording paper is the liquid droplet ejection means. Since the drive signal generation unit is controlled to generate a drive signal that is smaller than the droplet volume of the processing liquid ejected from the other nozzles, the ink liquid ejected from each nozzle depends on the position of the nozzle. Even when variations in the amount of droplets occur, it is possible to suppress a decrease in the image quality of the recorded image.

  In the present embodiment, the CPU 50 discharges from the nozzles 40 that are located within a predetermined distance from the nozzles 40A and 40B in the orthogonal direction among the nozzles 40 provided in the recording heads 14C, 14M, 14Y, and 14K. In the region where the ink liquid to be applied adheres to the recording paper P, the amount of decrease in the treatment liquid droplet amount decreases as the distance from the position corresponding to the boundary between the nozzle 40A and the nozzle 40B in the orthogonal direction decreases, and the normal droplet amount is obtained. To control. In this method, driving is performed by controlling the gain amount of an amplifier built in the head control unit 64 so as to generate a driving signal close to the droplet amount of the processing liquid ejected from the other nozzle 40 of the recording head 14H. The amplitude of the drive waveform of the signal may be controlled, and when the number of gradations that can be recorded by the recording head 14 is large (for example, in the case of 8 gradations), the gradation value of the recording data for the treatment liquid is changed. In this manner, the recording data creation unit 62 may be controlled. As a result, as the distance from the nozzle array 49 increases, bleeding of the CMYK ink liquids is reduced, so that it is possible to suppress image deterioration due to bleeding.

  Banding tends to stand out when a medium density image is recorded. For this reason, the CPU 50 discharges from the nozzles 40 located within a predetermined distance from the nozzles 40A and 40B in the orthogonal direction among the nozzles 40 provided in the recording heads 14C, 14M, 14Y, and 14K based on the image data. The density area in which the average density of the image recorded in the area where the ink liquid to be applied adheres to the recording paper P is more conspicuous (for example, the closer the density is to the medium density), Control is performed so as to increase the amount of decrease in the amount of the treatment liquid ejected to the region. The method is built in the head controller 64 so as to generate a drive signal for increasing the amount of decrease in the droplet volume of the processing liquid ejected to the recording area from the nozzle 40 provided in the recording head 14H. The gain amount of the amplifier may be controlled to control the amplitude of the drive waveform of the drive signal. When the number of gradations that can be recorded by the recording head 14 is large, the gradation value of the recording data for the treatment liquid is changed. In this manner, the recording data creation unit 62 may be controlled. As a result, when a medium density image is recorded in the area, bleeding of the CMYK ink liquid becomes large, and therefore banding can be made inconspicuous.

Also, if the penetration degree of the deposited droplets to the recording sheet is large, a large bleeding when droplets are absorbed into the recording paper, the banding becomes difficult conspicuous. On the other hand, if the penetration degree of the deposited droplets to the recording paper is small, bleeding when droplets are absorbed into the recording paper is small, banding conspicuous. For example, since the penetration degree of the droplets is glossy paper <coated paper <plain paper, banding tends to be conspicuous in the order of glossy paper> coated paper> plain paper with the same droplet amount. For this reason, in the present embodiment, for example, a detection unit that detects the type of the recording paper P is provided in the paper feed tray 18 or the type of the recording paper P is input from the control panel or the like. The smaller the degree of penetration of the ink liquid adhering to the recording paper P into the recording paper P, the closer to the orthogonal direction from the nozzles 40A and 40B of the recording heads 14C, 14M, 14Y, and 14K. Even if control is performed so that the amount of decrease in the droplet volume of the processing liquid discharged from the nozzle 40 provided in the recording head 14H is increased with respect to the area where the ink liquid discharged from the nozzle 40 adheres to the recording paper P. Good. As a result, the droplet volume of the discharged processing liquid is reduced, so that the banding can be made inconspicuous even for the recording paper P where banding is easily noticeable.

  Further, in the present embodiment, the method of controlling the droplet volume of the processing liquid when the recording data for the processing liquid is generated in the step 108 and the recording data generating unit 62 is changed by changing the droplet type (large, medium, small). However, the present invention is not limited to this. For example, the amount of droplets per unit area is set as follows. You can change it. That is, assuming that a normal processing liquid is one in which m dots (m ≦ n × n) are recorded in an area having n × n dots, the amount of the processing liquid is reduced if the number is less than m. It becomes control. Further, a method of determining the droplet amount of the processing liquid in relation to the total amount of CMYK ink liquids may be employed. For example, in a printer in which A% (A ≦ 100) of the total droplet volume of the ink liquid per unit area is determined as the droplet volume of the processing liquid, a control to reduce the droplet volume of the processing liquid by reducing the value of A. It becomes.

  Further, in the present embodiment, when the recording head 14 deforms the piezoelectric element 48 to generate a volume change in the pressure chamber 46 in which the liquid is accommodated, a piezoelectric method is adopted in which droplets are ejected from the nozzle 40. However, the present invention is not limited to this. For example, by generating air bubbles in the liquid in the pressure chamber 46 containing the liquid by generating heat from the heat generating element, droplets are discharged from the nozzle 40. You may employ | adopt the thermal system to discharge. Also in this case, the same effects as in the present embodiment can be obtained.

  In the present invention, the recording head 14 is a long head wider than the width of the recording paper, and the recording paper is moved relative to the long head to record an image. However, the present invention may be applied to the printer 10 that moves the recording head 14 with respect to the recording paper. For example, the recording paper 14 is moved back and forth in the main scanning direction with respect to the recording paper. The present invention may be applied to the printer 10 that records an image. Also in this case, the same effects as in the present embodiment can be obtained.

  In addition, the configuration of the printer 10 described in this embodiment (see FIGS. 1 and 2), the configuration of the recording head 14 (see FIGS. 3 and 4), and the configuration of the electrical system of the printer 10 (see FIG. 5). It is an example, and it is needless to say that it can be appropriately changed without departing from the gist of the present invention.

  Further, the flow of processing of the image recording processing program (see FIG. 6) described in the present embodiment is also an example, and it goes without saying that it can be changed as appropriate without departing from the gist of the present invention.

Further, the printer 10 described in the present embodiment records an image (including characters) on a recording sheet , but the printer 10 of the present invention is not limited to this. That is, the recording paper is not limited to the recording paper, and the liquid to be ejected is not limited to the ink liquid. For example, the present invention can also be applied to other droplet discharge recording apparatuses such as a pattern forming apparatus that discharges droplets onto a sheet-like substrate for pattern formation of a semiconductor or a liquid crystal display.

1 is a configuration diagram illustrating a configuration of a printer according to an embodiment. FIG. 3 is a configuration diagram illustrating an arrangement configuration during maintenance of the printer according to the embodiment. FIG. 3 is a plan view illustrating a detailed configuration of a recording head according to an embodiment. FIG. 4 is a cross-sectional view illustrating a detailed configuration of one nozzle portion of the recording head according to the embodiment. 1 is a block diagram illustrating a configuration of an electrical system of a printer according to an embodiment. It is a flowchart which shows the flow of a process of the image recording process program which concerns on embodiment. (A) is a figure which shows an example of the image recorded by the printer which concerns on embodiment, (B) is a graph which shows the relationship between the nozzle and the droplet volume of the process liquid discharged. It is a figure which shows an example of the image recorded by the conventional printer.

Explanation of symbols

10 Printer 14 Recording head 40 Nozzle 49 Nozzle array 50 CPU
62 Recording data creation unit 64 Head control unit P Recording paper

Claims (5)

A plurality of nozzle rows in which a plurality of nozzles are arranged with respect to the relative movement direction of the nozzle and the recording paper to be image-recorded do not overlap each nozzle row with the adjacent nozzle row in the movement direction. The nozzles are provided at substantially equal intervals with respect to the direction orthogonal to the moving direction, and each nozzle row is provided at a predetermined angle with respect to the moving direction, and aggregates the colored ink liquid or the ink liquid. A plurality of droplet discharge means for discharging the processing liquid from the nozzles to the recording paper that moves relative to the moving direction;
Of the nozzles provided in the droplet discharge means for discharging the ink liquid, the nozzle rows adjacent to each other in the orthogonal direction of the nozzle rows adjacent to each other from the leading nozzle and the trailing nozzle in the moving direction. With respect to a region where ink liquid ejected from nozzles located within a predetermined distance with respect to the orthogonal direction adheres to the recording paper, the region is provided in the region provided in the droplet ejection unit that ejects the processing liquid. Control is performed so that the droplet volume of the processing liquid discharged from the nozzle that discharges the processing liquid is smaller than the droplet volume of the processing liquid discharged from the other nozzles of the droplet discharge means , and the ink liquid is In the region adhering to the recording paper, the treatment liquid is separated from the position where the ink liquid ejected from the leading nozzle and the trailing nozzle adheres with respect to the orthogonal direction. The droplet volume of the treatment liquid ejected from the nozzle that ejects the treatment liquid to the region provided in the droplet ejection means that exits is close to the droplet volume of the treatment liquid ejected from the other nozzle. Control means for controlling;
A droplet discharge device comprising:   The control means includes a nozzle provided in the droplet discharge means for discharging the processing liquid in a density region in which an average density of an image recorded in the region where the ink liquid adheres to the recording paper is more conspicuous. Control to increase the decrease amount of the treatment liquid droplets discharged to the area.
  The droplet discharge device according to claim 1.   As the degree of penetration of the ink liquid adhering to the recording paper into the recording paper is smaller, the control means causes the ink liquid to be discharged from the nozzles provided in the droplet discharging means for discharging the processing liquid. Control to increase the decrease amount of the droplets of the processing liquid ejected to the region adhering to the substrate
  The droplet discharge device according to claim 1 or 2.   Drive signal generation means for generating a drive signal to be discharged from each nozzle of the plurality of droplet discharge means;
  The plurality of droplet discharge means discharges the ink liquid or the processing liquid from the nozzles to the recording paper in an amount corresponding to a drive signal supplied from the drive signal generation means corresponding to each nozzle. Shall be
  The control unit controls the droplet amount of the processing liquid ejected from a nozzle provided in the droplet ejection unit that ejects the processing liquid by controlling the driving signal generation unit.
  The droplet discharge device according to any one of claims 1 to 3.   A plurality of nozzle rows in which a plurality of nozzles are arranged with respect to the relative movement direction of the nozzle and the recording paper to be image-recorded do not overlap each nozzle row with the adjacent nozzle row in the movement direction. The nozzles are provided at substantially equal intervals with respect to the direction orthogonal to the moving direction, and each nozzle row is provided at a predetermined angle with respect to the moving direction, and aggregates the colored ink liquid or the ink liquid. A droplet discharge program that is executed in a droplet discharge device that includes a plurality of droplet discharge units that discharge processing liquid from a nozzle to a recording sheet that moves relatively in the moving direction.
  Of the nozzles provided in the droplet discharge means for discharging the ink liquid, the nozzle rows adjacent to each other in the orthogonal direction of the nozzle rows adjacent to each other from the leading nozzle and the trailing nozzle in the moving direction. With respect to a region where ink liquid ejected from nozzles located within a predetermined distance with respect to the orthogonal direction adheres to the recording paper, the region is provided in the region provided in the droplet ejection unit that ejects the processing liquid. Control is performed so that the droplet volume of the processing liquid discharged from the nozzle that discharges the processing liquid is smaller than the droplet volume of the processing liquid discharged from the other nozzles of the droplet discharge means, and the ink liquid is In the region adhering to the recording paper, the treatment liquid is separated from the position where the ink liquid ejected from the leading nozzle and the trailing nozzle adheres with respect to the orthogonal direction. The droplet volume of the treatment liquid ejected from the nozzle that ejects the treatment liquid to the region provided in the droplet ejection means that exits is close to the droplet volume of the treatment liquid ejected from the other nozzle. Control step to control
  Droplet program for causing a computer to execute.