JP2018030299A - Droplet discharge device and droplet discharge control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet discharge control device capable of avoiding waste of information storage area which is caused by sectioning thereof for each pass of information delay processing.SOLUTION: A head module having two-dimensionally arranged nozzles, when allowing each of nozzles arranged in a main scan direction to discharge ink droplets, performs delay processing on the nozzles located at different nozzle positions in a sub scan direction using non-discharge data to make each dot printed in line such that the dot forms an inclination angle of 0° with respect to the main scan direction. The delay processing does not set a unit storage part 212 at each different delay timing, but it instead consecutively stores real data and non-discharge data in time sequence in data areas 212A-212C with delay processing taken into account regardless of delay timing.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a droplet discharge device and a droplet discharge control device.

  Patent Document 1 discloses a nozzle for a two-dimensional array head and a circuit for delaying data together. Specifically, raster data is distributed to cache blocks, grouped for each two-dimensionally arranged nozzle drive timing, and data is stored in a DRAM block corresponding to each cache block. It is described that the DRAM block shifts one address for each printing clock.

JP 2007-168230 A

  In the two-dimensionally arranged heads, when the existing memory is divided for each delay processing time of information corresponding to the nozzles arranged in the main scanning direction, the existing memory increases according to the number of nozzle arrangements in the main scanning direction.

  An object of the present invention is to provide a droplet discharge device and a droplet discharge control device that can eliminate waste of an information storage area by dividing each information delay process.

  According to the first aspect of the present invention, a head in which nozzles for ejecting droplets are two-dimensionally arranged based on droplet ejection data and a first storage for individually storing a plurality of droplet ejection data in the main scanning direction are stored. In order to secure a storage area that satisfies the total number of the number of areas and the number of second storage areas that individually store a plurality of non-ejection data for delaying droplet ejection, the total number is not satisfied. And a storage means having a minimum number of storage elements each having a storage area.

  The invention described in claim 2 is the invention according to claim 1, wherein the droplet discharge data is low gradation data for distinguishing at least large droplets, medium droplets, small droplets, and non-discharge. The non-ejection data is low gradation data instructing non-ejection.

  According to the third aspect of the present invention, the sub-scanning is relatively performed for each main scanning line while the head in which the nozzles for ejecting droplets are two-dimensionally arranged based on the droplet ejection data and the droplet ejection target are relatively sub-scanned. When ejecting droplets from nozzles, non-ejection data corresponding to the two-dimensional array pattern is set for each nozzle, and the droplet ejection timing is delayed stepwise along the main scanning direction. Discharge control means for performing the operation, the number of first storage areas for individually storing a plurality of droplet ejection data in the main scanning direction, and a second for individually storing a plurality of non-ejection data for delaying droplet ejection. In order to secure a storage area that satisfies the total number of storage areas, a storage means in which only a minimum number of storage elements having a storage area that is less than the total number is mounted, and storage elements Recognize storage status and store and retrieve data Management means for management, a droplet ejection control device having a.

  According to a fourth aspect of the invention, in the invention of the third aspect, the actual data for discharging the droplet is at least low gradation data for distinguishing large droplets, medium droplets, small droplets and non-ejections. The non-ejection data is low gradation data for instructing non-ejection.

  According to a fifth aspect of the present invention, in the invention according to the third or fourth aspect, a read address is set according to the write address when the management means stores the droplet discharge data.

  According to a sixth aspect of the present invention, in the third aspect of the invention, when the number of nozzles in the main scanning direction is M and the number of nozzles in the sub-scanning direction is S, the number of arrangements M> the number of arrangements It is a number S, and the nozzles in the main scanning direction divided by the number of arrangement S are set as one unit, and the liquid discharge data is stored by being delayed step by step in one sub-scanning unit. Non-ejection data is stored for the nozzle on the upstream side in the sub-scanning direction.

  According to the first aspect of the present invention, it is possible to eliminate waste of the information storage area by dividing each information delay process.

  According to the second aspect of the present invention, noise (unnecessary droplet discharge) can be prevented in the delay processing.

  According to the third aspect of the present invention, it is possible to eliminate waste of the information storage area due to the division for each information delay process.

  According to the fourth aspect of the present invention, noise (unnecessary droplet discharge) can be prevented in the delay processing.

  According to the fifth aspect of the invention, the address at the time of writing can be used effectively.

  According to the sixth aspect of the present invention, it is possible to establish a storage procedure considering delay processing.

It is a schematic block diagram which shows an example of the main components of the inkjet recording device which concerns on this Embodiment. FIG. 4 is a plan view of a print head conceptually showing a delay processing situation indicating droplet discharge timing according to the present embodiment. It is a control block diagram of a head drive control unit provided in the main controller according to the present embodiment. FIG. 4 is a control block diagram showing details of a rearrangement processing unit of the head drive control unit shown in FIG. 3. 4 is a flowchart illustrating an image processing control routine in a head drive control unit according to the present embodiment. It is a control flowchart which shows the detail of the rearrangement process performed by step 260 of FIG. It is a conceptual diagram which shows the data storage state to the unit storage part allocated for every A group data (A1-A6) based on this Embodiment. It is a transition diagram which shows the state from storage of A3 data of FIG. 7 to transfer. It is a conceptual diagram which shows the data storage state to the unit storage part allocated for every data (A1-A6) of A group based on a comparative example.

  In this specification, “image formation” and “printing” refer to the formation and reproduction of images such as characters, pictures, and photographs on paper or the like. In this specification, “image formation” and “printing” are treated as being synonymous in a broad sense. Further, “printing” indicates an operation at the time of image formation (or printing), and in this specification, ink droplets are ejected from nozzles of print heads 50A and 50B as examples of heads described later. The operation is “printing”.

(Outline of equipment)
FIG. 1 is a schematic configuration diagram of an inkjet printer 12 as a droplet discharge device according to the present embodiment.

  The ink jet printer 12 includes, for example, two sets of image forming units 20A and 20B, a main controller 22, a paper feed roll 80, a discharge roll 90, and a plurality of transport rollers 100.

  The image forming unit 20A includes, for example, a head drive unit 40A, a print head 50A, a heater drive unit 60A, a drying device 70A, and a paper speed detection sensor 110A.

  Similarly, the image forming unit 20B includes, for example, a head driving unit 40B, a print head 50B, a heater driving unit 60B, a drying device 70B, and a paper speed detection sensor 110B.

  The print head 50A includes four print heads 50AC, 50AM, 50AY, and 50AK corresponding to four colors of C, M, Y, and K, respectively, and droplets of the corresponding colors from the print head 50A. A certain ink droplet is ejected.

  Similarly, the print head 50B includes four print heads 50BC, 50BM, 50BY, and 50BK corresponding to four colors of C color, M color, Y color, and K color, respectively. Ink droplets, which are droplets, are ejected.

  The driving method for ejecting ink droplets in the print heads 50A and 50B is not particularly limited, and a known method such as a so-called thermal method or piezoelectric method is applied.

  Hereinafter, when it is not necessary to distinguish between the image forming unit 20A and the image forming unit 20B, and the common members included in the image forming unit 20A and the image forming unit 20B, the symbol “A” and the symbol at the end of the symbol are used. “B” is omitted.

  The main controller 22 includes an image processing control system that controls the head driving unit 40A, a conveyance control system that controls conveyance of the paper P, and a drying control system that controls the heater driving unit 60A. The image forming process is executed.

  That is, the main controller 22 drives a paper conveyance motor (not shown) to control the rotation of the conveyance roller 100 connected to the paper conveyance motor via a mechanism such as a gear. A long paper P is wound around the paper feed roll 80 as a recording medium in the paper transport direction, and the paper P is transported in the paper transport direction as the transport roller 100 rotates.

  Further, the main controller 22 receives image information, for example, and controls the image forming unit 20A based on the color information for each pixel of the image included in the received image information, so that one image forming surface of the paper P is applied. An image corresponding to the image information is formed.

  The head drive unit 40A drives the print head 50A connected to the head drive unit 40A in accordance with the ink droplet discharge timing instructed from the main controller 22, discharges ink droplets from the print head 50A, and transported paper An image corresponding to the image information is formed on one image forming surface of P.

  The heater drive unit 60A includes a switching element that controls the amount of heat by turning on and off a heater (not shown) included in the drying apparatus 70A, and drives the switching element based on an instruction from the main controller 22.

  Then, the main controller 22 controls the heater driving unit 60A to dry the ink droplets of the image formed on the paper P by the drying air including the radiant heat from the drying device 70A toward one image forming surface of the paper P. The image is fixed on the paper P. The main controller 22 can improve the drying efficiency by controlling the heater on / off while maintaining the drive current based on the image information. In addition, you may make it control the strength of a drive current. In addition, you may use the dry form using a laser beam as a dry form.

  Thereafter, the sheet P is transported to a position facing the image forming unit 20 </ b> B as the transport roller 100 rotates. At this time, the paper P is conveyed so that the other image forming surface different from the image forming surface on which the image is formed by the image forming unit 20A faces the image forming unit 20B.

  The main controller 22 forms an image corresponding to the image information on the other image forming surface of the paper P by executing the same control as the control for the image forming unit 20A on the image forming unit 20B.

  Then, the paper P is transported to the discharge roll 90 as the transport roller 100 rotates, and is wound around the discharge roll 90.

  Ink drops include water-based inks, oil-based inks that are inks whose solvent evaporates, and ultraviolet curable inks. In this embodiment, any type of ink drops can be applied.

  As shown in FIG. 2, the print heads 50A and 50B have a plurality of print heads along a direction B (for example, a direction orthogonal to the main scanning direction) that intersects the transport direction A (referred to as the sub-scanning direction) of the paper P. The head modules 52 are arranged. Each head module 52 has the same structure, and FIG. 2 illustrates the first head module 52M1 to the third head module 52M3.

  In the head module 52, nozzles from which ink droplets are ejected are two-dimensionally arranged. In FIG. 2, the positions of the nozzles are illustrated in a matrix of row numbers (1 to 6) and column numbers (A1 to A6, B1 to B6).

  As an example, the number of nozzles in the sub-scanning direction × the number in the main scanning direction = 6 × 12, and a total of 72 nozzles are two-dimensionally arranged. The main scanning direction is classified into two groups (Group A and Group B) (A1 to A6 and B1 to B6).

  Hereinafter, an execution example of ink droplet ejection by the print heads 50A and 50B will be described.

  2, in each head module 52, one nozzle is selected from each group (Group A and Group B) for each row in the sub-scanning direction (marked with a black circle (●) illustrated in an oblique direction in FIG. reference). The inclined inclination angle is canceled based on the conveyance speed of the paper P, so that the ink droplets ejected after the delay process are along the main scanning direction (with an inclination angle of 0 ° with respect to the main scanning direction). Will be arranged in a row.

  By the way, when printing on the paper P (image formation by ink droplet ejection) is started (at the time of setting), in order to prevent ink droplets from being ejected from the nozzles according to the delay processing, actual data for ejecting ink droplets in practice Separately, it is necessary to set non-ejection data in which ink droplets are not ejected.

  For example, the necessity of non-ejection data at each arrangement position of the group A when ejecting ink droplets along the main scanning direction of the first line is shown.

  When ink droplets are ejected from A1, actual data must be stored in A1, and non-ejection data must be stored in A2 to A6.

  When ink droplets are ejected from A2, actual data must be stored in A2, and non-ejection data must be stored in A3 to A6.

  When ejecting ink droplets from A3, it is necessary to store actual data in A3 and store non-ejection data in A4 to A6.

  When ejecting ink droplets from A4, it is necessary to store actual data in A4 and store non-ejection data in A5 to A6.

  That is, it can be seen that the number of non-ejection data stored differs for each arrangement number of each group.

  The head driving units 40A and 40B (see FIG. 1) are configured to supply ink droplets from the print heads 50A and 50B based on the control of the head driving control unit 200 (see FIG. 3A) that functions as a part of the main controller 22. Perform dispensing.

  In the head drive control unit 200, a field programmable gate array (FPGA), which is a kind of PLD (programmable logic device), is applied as a programming circuit including droplet ejection control by the print heads 50A and 50B. In addition, since other integrated circuits, such as ASIC (Application Specific Integrated Circuit), may be used, in the following, they are collectively referred to as “integrated circuits”.

  In the integrated circuit, a storage area 202 (see FIGS. 3A and 3B) as an example of storage means for storing print data (actual data and non-ejection data) is secured.

(Image processing control by the main controller 22)
FIG. 3A shows an image processing system of the main controller 22, for example, a raster during printing for acquiring image information from the outside including an information terminal and a server (not shown) and sending out the head drive units 40 </ b> A and 40 </ b> B. It is a block diagram which shows the head drive control part 200 converted into image data according to a function. Note that the block diagram of FIG. 3A categorizes the control in the head drive control unit 200 by function, and does not limit the hardware configuration.

  Image data received from the outside by the main controller 22 is input to the image conversion unit 204.

  The image conversion unit 204 has a function of converting image data (print data) such as PDL into bitmap data by raster image conversion.

  The image conversion unit 204 is connected to the color conversion unit 206, and the image conversion unit 204 sends the converted bitmap data to the color conversion unit 206.

  The color conversion unit 206 converts the color space of the bitmap data (color space conversion process). For example, RGB data is converted into YMCK data. Further, the color conversion unit 206 executes γ correction processing.

  The color conversion unit 206 is connected to the image processing unit 208, and the color conversion unit 206 sends the data after the color space conversion process and the γ correction process to the image processing unit 208.

  The image processing unit 208 performs screen processing such as dither processing on the data after the color space conversion processing and γ correction processing, and has low gradation (for example, large droplets, medium droplets, small droplets) that can be printed by the print heads 50A and 50B. Droplets and non-ejection four gradations are expressed in 2 bits).

  The image processing unit 208 is connected to the rearrangement processing unit 210, and the image processing unit 208 sends the print image data to the rearrangement processing unit 210.

  The rearrangement processing unit 210 executes rearrangement processing based on the arrangement of the print heads 50A and 50B, and sends the low gradation data after the screen processing to the head driving unit 40A (40B).

  The rearrangement processing unit 210 includes a storage area 202 for storing data after rearrangement processing, and stores data (line data) for each main scan to be sent to the head driving unit 40A (40B). The head driving unit 40A (40B) drives the print heads 50A and 50B based on the rearranged data, and ejects ink droplets in synchronization with the conveyance of the paper P.

  As shown in FIG. 3B, the storage area 202 of the rearrangement processing unit 210 is an example of the number of storage elements required for each delay process, with an existing storage unit having a predetermined storage capacity as one unit. Unit storage unit 212 is prepared.

  In the integrated circuit to which the unit storage unit 212 is applied, the storage capacity is fixed in advance. In this embodiment, the unit storage unit 212 can store 3 dots of data (an example of the first storage area and the second storage area). 3 data areas 212A to 212C).

  FIG. 4 is a functional block diagram showing details of processing in the rearrangement processing unit 210 in FIG. The rearrangement processing unit 210 includes a data storage unit 214 and a data transfer unit 216.

  In the data storage unit 214, when the image data for printing sent from the image processing unit 208 is received by the reception unit 218, the reception unit 218 temporarily stores the received data (for example, data for one sheet) such as a cache memory. The data is temporarily stored in the unit 220.

  The accepting unit 218 is connected to the non-ejection data generation unit 222, and generates non-ejection data at the time of setting to the non-ejection data generation unit 222 when the printing image data is accepted. Instruct.

  When the non-ejection data generation unit 222 generates the non-ejection data at the time of setting, the non-ejection data generation unit 222 stores the generated non-ejection data in the unit storage unit 212 as illustrated in FIG. To do. The temporary storage unit 220 stores actual data (accepted data).

  The temporary storage unit 220 is connected to the line data fetch unit 224. The line data capturing unit 224 captures printing image data for each main scan (one line) from the temporary storage unit 220 and sends it to the storage area allocation unit 226.

  The storage area allocation unit 226 executes the specification of the unit storage unit 212 provided in the storage area 202 and the allocation of the data areas 212A to 212C (addresses) in the specified unit storage unit 212, and the read / write unit 228 To be stored in the storage area 202.

  The storage area 202 is a collection of unit storage units 212.

  FIG. 7 is a conceptual diagram showing a storage area allocation situation when data of group A (A1 to A6) of the head module 52 in the present embodiment is stored in the storage area 202. FIG.

  In the A1 data, the upper stage (data area A) of the first unit storage unit 212 (1) is the storage area 202.

  As the A2 data, one of the middle and lower stages (data areas B and 212C) of the first unit storage unit 212 (1) is selected.

  For the A3 data, any one of the second unit storage units 212 (2) (data areas A to C) is selected.

  For the A4 data, all of the third unit storage unit 212 (3) (data areas A to C) and the upper stage (data area 212A) of the fourth unit storage unit 212 (4) are selected. The

  For the A5 data, the middle and lower stages of the fourth unit storage unit 212 (data areas B and C) and all of the fifth unit storage unit 212 (data areas A to C) are selected.

  For the A6 data, all of the sixth and seventh unit storage units 212 (6) and 212 (7) (data areas A to C) are selected.

  FIG. 8 is a transition diagram showing a state from storage to transfer of data when the A3 data in FIG. 7 is taken as an example.

  In the present embodiment, a FIFO (first-in first-out) operation is performed on the data.

  As shown in FIG. 8A, the previous job is completed and non-ejection data for delay processing of the next job is generated. That is, the data area A is empty, the non-ejection data 1 is stored in the data area B, and the non-ejection data 2 is stored in the data area C.

  Next, as shown in FIG. 8B, the non-ejection data 1 in the data area B and the non-ejection data 2 in the data area C stored in FIG. 8A are shifted to the upper stage (data area B). → A, C → B), the actual data of the first line is stored in the data area C. Subsequently, although not shown, the non-ejection data 1 in the data area A is sent out, and the non-ejection data 2 in the data area B and the actual data on the first line in the data area C are shifted to the upper stage ( Data area B → A, C → B) and data area C store the actual data of the second line.

  FIG. 8C shows the progress of the FIFO operation. After the actual data on the N-3th line in the data area C is transmitted, the actual data on the N-2th line in the data area B and The actual data of the (N−1) th line in the data area C is shifted to the upper stage (data area B → A, C → B), and the actual data of the Nth line is stored in the data area C.

  As shown in FIG. 4, the read / write unit 228 is connected to the line data acquisition unit 230 of the data transfer unit 216. The line data acquisition unit 230 acquires the line data read from the storage area 202 by the read / write unit 228.

  The line data acquisition unit 230 is connected to the transfer unit 232.

  The transfer unit 232 sends the line data acquired by the line data acquisition unit 230 to the head drive unit 40A (40B).

  When the transfer in the transfer unit 232 is completed, the line data acquisition unit 230 receives the transfer end notification and repeats acquiring the next line data from the read / write unit 228.

  The operation of the present embodiment will be described below.

(Printing procedure)
By driving the paper transport motor, the paper P is transported from the paper feed roll 80 in the paper transport direction, image information is acquired, and the image forming unit 20A is controlled based on the color information for each pixel of the image included in the image information. By controlling, an image corresponding to the image information is formed on one image forming surface of the paper P. Then, by controlling the heater driving unit 60A, the ink droplets of the image formed on the paper P are dried by the drying air including the radiant heat from the drying device 70A toward one image forming surface of the paper P, and the paper Fix the image on P.

  Thereafter, the sheet P is transported to a position facing the image forming unit 20 </ b> B as the transport roller 100 rotates. At this time, the paper P is transported so that the other image forming surface different from the image forming surface on which the image is formed by the image forming unit 20A faces the image forming unit 20B, and the other side of the paper P is transferred by the image forming unit 20B. An image corresponding to the image information is formed on the image forming surface, and dried by the drying device 70B to fix the image. Then, the paper P is transported to the discharge roll 90 as the transport roller 100 rotates, and is wound around the discharge roll 90.

  FIG. 5 is a flowchart showing an image processing control routine in the head drive control unit 200 according to the present embodiment.

  In step 250, it is determined whether image data has been received. If the determination is negative, this routine ends.

  If an affirmative determination is made in step 250, the process proceeds to step 252 to execute image conversion processing. In the image conversion process, image data (print data) such as PDL is converted into bitmap data by raster image conversion.

  In the next step 254, color space conversion processing of bitmap data is executed. In the color space conversion process, the color space of the bitmap data is converted from RGB to YMCK.

  In the next step 256, γ correction processing of the bitmap data whose color space has been converted is executed, and the process proceeds to step 258.

  In step 258, print image data is generated. In the printing image data generation processing, screen processing such as dither processing is performed on the data after the color space conversion processing and γ correction processing, and low gradation (for example, 2 bits) that can be printed by the print heads 50A and 50B. Convert to print image data.

  In the next step 260, the print image data rearrangement process (detailed in FIG. 6) is executed, and in this rearrangement process, the data is transferred to the head drive units 40A and 40B, and this routine ends. To do.

  FIG. 6 is a control flowchart showing details of the rearrangement process executed in step 260 of FIG.

  In step 270, non-ejection data at the time of setting is generated, and then the process proceeds to step 271 where the non-ejection data is stored in the storage area 202 as an initialization process, and the process proceeds to step 272.

  In step 272, printing image data (actual data for one image (one sheet)) is temporarily stored in the temporary storage unit 220, and the process proceeds to step 274.

  In step 274, data for one line is fetched from the temporary storage unit 220, and then the process proceeds to step 276 to execute allocation to the storage area 202. In the next step 278, based on the assignment in step 276, the actual data is stored in the data areas 212A to 212C in each unit storage unit 212 of the storage area 202 (see FIG. 7).

  In the present embodiment, when allocating to the storage area 202, the unit storage section 212 is effectively used in the data areas 212A to 212C of each unit storage section 212 without partitioning the unit storage section 212 for each delay process based on non-ejection data. The number of units 212 is reduced as compared with the case where each unit is divided for each delay process. Details of the reduction of the number by effective use of the unit storage unit 212 will be described later.

  In the next step 280, it is determined whether or not it is the printing time. If a negative determination is made, the process waits until an affirmative determination is made in step 280. If an affirmative determination is made in step 280, the process proceeds to step 282, data for one line is acquired from the storage area 202, the process proceeds to step 284, and the data is transferred to the head drive unit 40A (40B).

  In the next step 286, for example, the transfer to the read / write unit 228 is notified.

  In the next step 288, it is determined whether or not one image has been completed. If a negative determination is made, the process returns to step 274, and the read / write unit 228 determines the next one line based on the transfer notification in step 286. Minute data is acquired and the above process is repeated.

  If the determination at step 288 is affirmative, this routine ends.

(Reduction of the number by effective use of the unit storage unit 212)
Here, in the present embodiment, the number of unit storage units 212 is reduced by effectively using the unit storage units 212 provided in the storage area 202 of the rearrangement processing unit 210.

  In the following, the fact that this embodiment has reduced the number of unit storage units 212 will be demonstrated by comparing with a comparative example.

"Comparative example"
As a comparative example, FIG. 9 shows an example in which the unit storage unit 212 is allocated for each data (A1 to A6) of the A group.

  At the time of setting, the following number of unit storage units 212 are allocated in the group A of the head module 52.

  In A1, one unit storage unit 212 is allocated as a storage area for storing the actual data 1.

  In A2, one unit storage unit 212 is allocated as a storage area for storing actual data 1 and non-ejection data 1.

  In A3, one unit storage unit 212 is allocated as a storage area for storing the actual data 1 and the non-ejection data 1 and 2.

  In A4, two unit storage units 212 are allocated as storage areas for storing actual data 1 and non-ejection data 1 to 3.

  In A5, two unit storage units 212 are allocated as storage areas for storing the actual data 1 and the non-ejection data 1 to 4.

  In A6, two unit storage units 212 are allocated as storage areas for storing actual data 1 and non-ejection data 1 to 5.

  In the case of this comparative example, a total of nine unit storage units 212 are required.

"This embodiment"
FIG. 7 shows an example in which the unit storage unit 212 is allocated for each data (A1 to A6) of the group A according to the present embodiment.

  At the time of setting, the following number of unit storage units 212 are allocated in the group A of the head module 52.

  A1 is assigned with the first unit storage unit 212 as a storage area for storing the actual data 1.

  Here, since the first unit storage unit 212 has a space for two data, it is used as a storage area for storing the actual data 1 and non-ejection data 1 of A2. That is, A1 and A2 data (actual data and non-ejection data) are assigned to the first unit storage unit 212.

  In A3, the second unit storage unit 212 is allocated as a storage area for storing the actual data 1 and the non-ejection data 1 and 2. The second unit storage unit 212 matches the storage capacity of A3 data.

  In A4, the third and fourth unit storage units 212 are allocated as storage areas for storing the actual data 1 and the non-ejection data 1 to 3.

  A5 requires a storage area for storing the actual data 1 and the non-ejection data 1 to 4.

  Here, since there is a space for two data in the fourth unit storage unit 212, non-ejection data 1 and 2 of A5 are stored.

  The remaining data (actual data 1 and non-ejection data 3 and 4) in A5 are stored in the fifth unit storage unit 212. The fifth unit storage unit 212 matches the storage capacity of the remaining data of A5 (actual data 1 and non-ejection data 3 and 4).

  In A6, as the storage area for storing the actual data 1 and the non-ejection data 1 to 5, the sixth and seventh unit storage units 212 are allocated. The sixth and seventh unit storage units 212 match the data storage capacity of A6.

  In the present embodiment, a total of seven unit storage units 212 are required. That is, compared to the comparative example, the two unit storage units 212 can be reduced.

  According to the present embodiment, in the head module 52 of the print head 50, when ink droplets are ejected from the nozzles arranged in the main scanning direction, the delay process using the non-ejection data particularly at the time of setting results in By transporting the paper P, each dot is printed in a line at an inclination angle of 0 ° with respect to the main scanning direction. For this delay processing, it is common to set the unit storage unit 212 for each different delay time in the delay processing, whereas the data areas 212A to 212C of the unit storage units arranged regardless of the delay time. By using all of the above, a useless area does not occur in the storage area.

  In the ink jet printer 12 according to the present embodiment, two sets of image forming units 20A and 20B are arranged in series, and the paper P is reversed between the image forming unit 20A and the image forming unit 20B, so that the paper Although it is possible to print on the front and back surfaces of P, an ink jet printer that prints only one side may be used.

(Example)
Hereinafter, an embodiment in which the storage area 202 is mounted on a specific inkjet printer 10 will be described.

  When mounted in the configuration of the comparative example, the number of unit storage units 212 in the storage area 202 required 1023 36 Kbit SRAMs and 162 18 Kbit SRAMs.

  On the other hand, it was found that the number of unit storage units 212 in the storage area 202 when implemented with the configuration of the present embodiment can be 408 36 Kbit SRAMs and 5 18 Kbit SRAMs.

DESCRIPTION OF SYMBOLS 12 Inkjet printer 20A, 20B Image formation part 22 Main controller 40 (40A, 40B) Head drive part 50 (50A, 50B) Print head 50AC, 50AM, 50AY, 50AK Print head 50BC, 50BM, 50BY, 50BK Print head 52 (52M1) -52M3) Head module 60A, 60B Heater drive unit 70 (70A, 70B) Drying device 80 Paper feed roll 90 Discharge roll 100 Transport roller 110 (110A, 110B) Paper speed detection sensor 200 Head drive control unit 202 Storage area 204 Image conversion Unit 206 color conversion unit 208 image processing unit 210 rearrangement processing unit 212 unit storage unit 212A to 212C data area 214 data storage unit 216 data transfer unit 218 reception unit 220 temporary storage Part 222 non-ejection data generating unit 224 line data acquisition unit 226 storage area allocation unit 228 reading section 230 line data acquisition unit 232 the transfer unit

Claims (6)

A head in which nozzles for discharging droplets are two-dimensionally arranged based on droplet discharge data;
The number of first storage areas for individually storing a plurality of droplet ejection data in the main scanning direction, the number of second storage areas for individually storing a plurality of non-ejection data for delaying droplet ejection, In order to secure a storage area satisfying the total number of storage means, a storage means in which only a minimum number of storage elements having storage areas less than the total number are mounted,
A droplet discharge device having   The droplet ejection data is at least low gradation data for distinguishing between large droplets, medium droplets, small droplets, and non-ejection, and the non-ejection data is low gradation data for instructing non-ejection. The droplet discharge device according to 1. When droplets are ejected from the nozzles for each main scanning line while sub-scanning the head in which the nozzles for ejecting droplets are two-dimensionally arranged based on the droplet ejection data and the droplet ejection target. Discharge control means for setting non-discharge data in accordance with a two-dimensional array pattern for each of the nozzles, and discharging the liquid droplet discharge timing in stages along the main scanning direction;
The number of first storage areas for individually storing a plurality of droplet ejection data in the main scanning direction, the number of second storage areas for individually storing a plurality of non-ejection data for delaying droplet ejection, In order to secure a storage area satisfying the total number of storage means, a storage means in which only a minimum number of storage elements having storage areas less than the total number are mounted,
Management means for recognizing a storage state in the storage element and managing storage and retrieval of data;
A droplet discharge control apparatus comprising:   The droplet ejection data is at least low gradation data for distinguishing between large droplets, medium droplets, small droplets, and non-ejection, and the non-ejection data is low gradation data for instructing non-ejection. 3. The droplet discharge control device according to 3.   5. The droplet discharge control device according to claim 3, wherein the management unit sets a read address according to a write address when the droplet discharge data is stored. When the number of nozzle arrays in the main scanning direction is M and the number of nozzle arrays in the sub-scanning direction is S, the number of arrays M> the number of arrays S,
The nozzles in the main scanning direction divided by the number of arrangements S are set as one unit, and the liquid discharge data is stored by being delayed step by step in one sub-scan unit,
The liquid droplet ejection control apparatus according to claim 3, wherein non-ejection data is stored for a nozzle located upstream of the delayed nozzle in the sub-scanning direction.