JP2012030594A - Inkjet recording device and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recording device that maintains recording quality while improving recording speed.SOLUTION: The inkjet recording device includes a recording head having first to Mth (M is an aliquot of N) nozzle arrays having N (N is a natural number equal to or above 2) nozzles that eject the same color ink. The N nozzles in each nozzle array are grouped to first to Mth groups by N/M in accordance with prescribed driving order, and recording data corresponding to each nozzle array is divided into first to Mth recording data corresponding to the first to Mth groups. The first to Mth recording data corresponding to the first to Mth groups are dispersedly allotted to the first to Mth nozzle arrays so that the recording data corresponding to the nozzle arrays may be recorded by using the first to Mth nozzle arrays. The drive of the nozzles is controlled so that ink dots ejected from the nozzle that is the first one in driving order in each group may be superposed and recorded in a direction orthogonal to a scanning direction by each recording data corresponding to each nozzle array.

Description

The present invention relates to an ink jet recording apparatus and a recording method for driving a plurality of recording elements in a time-sharing manner.

  In recent years, recording apparatuses of various recording systems have been developed, and among them, the inkjet recording apparatus of the inkjet system is easy to handle colors, has low noise during operation, and has a high quality for a wide variety of recording media. There are advantages such as being able to record and being compact. As one of ink droplet ejection methods of an ink jet recording apparatus, a thermal ink jet printer using thermal energy is known. In this ink droplet ejection method, thermal energy is applied to ink by applying an electrical pulse as a recording signal to an electrothermal conversion element provided in the recording head, and the bubble pressure generated at this time is used for ejection of ink droplets. It is.

  The recording head driving method in the ink jet recording apparatus is a method in which a plurality of nozzles arranged in a line in the column direction (sub-scanning direction) are divided into groups and driven at different timings for each nozzle group specified over each group. A split drive system is generally used (Patent Document 1). As shown in FIG. 5, the nozzle row is grouped every 16 nozzles, and the 16 consecutive nozzles in each group are driven at 16 different timings. In other words, there are nozzles that are driven at the same timing for every 16 nozzles, and a nozzle group composed of nozzles for every 16 nozzles is called a block. FIG. 5A shows a state in which the nozzle rows are grouped, and b shows the discharge timing of 16 nozzles continuous in each group. The vertical axis of b shows the nozzle position in one column, and the horizontal axis shows time. In this example, the nozzles 32k + 1 to 32k + 31 are sequentially driven. Since the recording head continuously moves during recording, as a result, the dots ejected by the nozzles 32k + 1 to 32k + 31 are recorded as b. Here, at the timing when the nozzle 32k + 1 is driven, the other nozzles constituting the block to which the nozzle 32k + 1 belongs, that is, every 16 nozzles described above, are driven at the same timing.

  In the above description, for the sake of simplicity, an example in which the 32k + 1 to 32k + 31 nozzles are driven in order from 32k + 1 is shown, but any nozzle may be driven in what order. By driving the nozzles in a time-sharing manner in this way, it is possible to improve the ink supply speed and stability and reduce the power consumption required for ejection.

  By the way, when recording is performed by driving the nozzles in a time-sharing manner, one column on the paper surface has a certain width as shown in FIG. The width is determined by the relationship between the recording head, the ink-dependent ejection frequency, and the carriage speed. That is, when the ejection frequency is fixed, if the carriage speed is halved from FIG. 18A, the width of one column on the paper surface is halved as shown in FIG. 18B. If the carriage speed is doubled from FIG. 18A, the width of one column on the paper surface is doubled as shown in FIG. 18C. Also, in the case where the carriage speed is constant and the ejection is performed uniformly with respect to the driving cycle, if the ejection frequency is doubled from FIG. 18 (a), one column on the paper surface as shown in FIG. 18 (b). The width is halved. Further, when the ejection frequency is halved from FIG. 18A, the width of one column on the paper surface is twice as thick as shown in FIG. 18C. Here, if the width of one column is widened as shown in FIG. 18C, the resolution in the main scanning direction is lowered, which causes deterioration of recording quality, particularly character quality composed of ruled lines. End up.

  In recent years, improvement of the recording speed of an ink jet recording apparatus has become a particularly important issue. Examples of methods for improving the recording speed include increasing the length of the recording head, improving the ejection frequency, and using a plurality of recording heads. However, since the nozzle substrate of the recording head is manufactured from a single crystal silicon wafer, if the length of the recording head is increased, that is, if the nozzle substrate is enlarged, the number of nozzle substrates that can be manufactured from one silicon wafer is reduced. It will decrease and the cost will increase. Further, since the ejection frequency depends on the characteristics of the ink and the recording head, it is difficult to significantly improve the performance. As a method of performing recording using a plurality of recording heads, a method is disclosed in which the carriage speed is increased and the plurality of recording heads are alternately used in the main scanning direction (Patent Documents 2 and 3).

JP 2000-071433 A JP-A-2-047076 JP-A-5-318771

  In an inkjet recording apparatus that performs time-division driving, when recording is performed alternately in the main scanning direction using a plurality of recording heads, the resolution in the main scanning direction becomes equal, as shown in FIGS. 19A and 19B. The carriage speed can be improved without degrading the resolution. However, as shown in FIG. 19B, the width of one column on the recording medium is doubled as shown in FIG. 19A, and as a result, the vertical ruled lines and the character quality are reduced. .

  An object of the present invention is to solve such conventional problems. In view of the above points, an object of the present invention is to provide an ink jet recording apparatus and a recording method that maintain recording quality while improving recording speed.

In order to solve the above problems, an ink jet recording apparatus according to the present invention includes first to Mth nozzles (N is a divisor of N) having N (N is a natural number of 2 or more) nozzles that eject ink of the same color. A recording head having nozzle rows, scanning the recording head in a direction crossing the arrangement direction of the nozzle rows, and driving N nozzles of each nozzle row in a predetermined driving order on a recording medium. An inkjet recording apparatus that performs recording,
Grouping means for grouping N nozzles of each nozzle row into N-M groups in N / M units according to the driving order;
A dividing unit that divides print data corresponding to each nozzle row into first to Mth print data corresponding to the first to Mth groups;
The first to Mth groups corresponding to the first to Mth groups divided by the dividing unit so as to record the recording data corresponding to each nozzle row using the first to Mth nozzle rows. Allocating means for distributing and allocating the recording data to the first to Mth nozzle rows,
For each print data corresponding to each nozzle row, the ink dots ejected from the nozzle with the earliest drive order in each group assigned by the assigning unit are related to the direction orthogonal to the scan direction of the print head on the print medium. Drive control means for controlling the drive of the nozzles so as to overlap and record.

According to the present invention, it is possible to maintain the recording quality while improving the recording speed.

FIG. 2 is a diagram schematically illustrating a configuration example around a recording head of an ink jet recording apparatus. It is a block diagram which shows schematic structure around a controller. It is a figure which shows the structural example of a control circuit. It is a time chart which shows the change of the various signals supplied to a recording head. It is a figure which shows the position on the recording medium of an ink drop. FIG. 3 is a diagram illustrating a nozzle arrangement of a recording head according to a first example of the first embodiment. It is a figure which shows the allocation method of the recording data in this example. It is a 1st figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 2nd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 3rd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. FIG. 5 is a diagram illustrating a nozzle arrangement of a recording head according to a second example of the first embodiment. It is a figure which shows the allocation method of the recording data in this example. It is a 1st figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 2nd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 3rd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a figure which shows the allocation method of the recording data of 2nd Embodiment 1st example. It is a 1st figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 2nd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 3rd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a figure which shows the allocation method of the recording data in this example. It is a 1st figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 2nd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. It is a 3rd figure which shows the dot arrangement | sequence recorded on the recording medium in this example. FIG. 7 is a diagram showing a conventional method for assigning print data when the print head shown in FIG. 6 is used. FIG. 10 is a diagram showing a conventional method for assigning print data when the print head shown in FIG. 9 is used. It is a figure which shows the change of the recording width of 1 column. It is a figure explaining the dot arrangement recorded on the conventional recording medium.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the present invention according to the claims, and all combinations of features described in the present embodiments are not necessarily essential to the solution means of the present invention. . The same constituent elements are denoted by the same reference numerals, and the description thereof is omitted.

[Configuration example of recording device]
FIG. 1 is a diagram schematically illustrating a configuration example around a recording head of an inkjet recording apparatus 100 that performs recording using a plurality of nozzle arrays. The recording head cartridge 101 is provided corresponding to four color inks of black (K), cyan (C), magenta (M), and yellow (Y). Each recording head cartridge 101 includes an ink tank 102T filled with ink of any color, and a recording head 102H formed by arranging a number of nozzles that can eject ink supplied from the ink tank onto a recording medium. It is configured. A paper feed roller (feed roller) 103 rotates in the direction of the arrow in the figure while nipping a recording medium (recording paper or the like) 107 in cooperation with the auxiliary roller 104, and conveys the recording medium 107 in the y direction as needed. The pair of paper feed rollers 105 are moved to the recording position while sandwiching the recording medium 107. The pair of paper feed rollers 105 also has a function of maintaining the state of the recording medium 107 flat between the paper feed roller 103 and the auxiliary roller 104.

  The carriage 106 supports four recording head cartridges 101 and moves in the main scanning direction that intersects the arrangement direction of the nozzle rows of the recording head together with the recording head cartridge 101 in the case of a recording operation. Further, the carriage 106 is positioned at a position h (home position) indicated by a broken line in the drawing when the recording operation is not executed or when the recovery operation for maintaining the ink ejection performance of the recording head 102H is performed satisfactorily. To do. The carriage 106 positioned at the home position h before starting the recording operation starts to move in the x direction in response to the recording operation start command. After the movement starts, ink is ejected from a plurality of nozzles provided in the recording head 102H according to the recording data, and recording is performed. In the case of unidirectional recording, when the recording operation up to the end in the x-positive direction on the recording medium 107 is completed, the carriage 106 returns to the home position h and performs the recording operation again in the x-positive direction. In the case of bidirectional recording, the recording operation is performed even when moving in the x negative direction toward the home position h. In either case, the paper feed roller 103 rotates by a predetermined amount in the direction of the arrow in the figure before the next recording operation is started after the end of one recording operation (one scan) in one direction. The recording medium 107 is conveyed in the y direction by a predetermined amount. As described above, the recording data for one recording medium is recorded by repeating the recording operation for one scan and the conveying operation for a predetermined amount of the recording medium.

  FIG. 2 is a block diagram showing a schematic configuration around the controller mounted on the inkjet recording apparatus 100. The controller 200 includes a CPU 201 and a ROM 202 that stores a program for realizing the present embodiment, a predetermined table, and other fixed data. In addition, the controller 200 controls the carriage motor 241 and the paper feed motor 243, the special purpose integrated circuit (ASIC) 203 that generates a control signal for the recording head 102H, and an area for developing image data serving as recording data. And a RAM 204 provided with a work area and the like. The controller 200 also connects the CPU 201, the ASIC 203, and the RAM 204 to each other and inputs and receives analog signals from the sensor group 230 and a system bus 205 that transmits and receives data, and converts the digital signals to the CPU 201. An A / D converter 206 is provided.

  The host apparatus 210 is an apparatus outside the inkjet recording apparatus, such as a PC, an image reading apparatus, or a digital camera, and supplies image data to the inkjet recording apparatus 100. The ink jet recording apparatus 100 receives image data, commands, status signals, and the like via an interface (I / F) 211 and outputs them to the controller 200. The switch group 220 is a switch group for receiving an instruction input by an operator, such as the power switch 221, the switch 222 for instructing the start of the recording operation, the recovery switch 223 for instructing the start of the recovery operation. The sensor group 230 is a sensor group for detecting the apparatus state, such as a photocoupler 231 for detecting the home position h, and temperature sensors 232 provided at a plurality of locations of the inkjet recording apparatus 100 for detecting the temperature. is there. The carriage motor 241 scans the carriage 106 in the x positive direction and the negative direction, and the carriage motor driver 240 drives the carriage motor 241. The paper feed motor 243 conveys the recording medium 107, and the paper feed motor driver 242 drives the paper feed motor 243.

[Configuration example of print head controller]
FIG. 3 shows a recording head substrate (also referred to as a heater board) on which an electrothermal conversion element (also referred to as a discharge heater) that generates thermal energy that causes film boiling in ink as energy used for ink discharge is formed. 3 is a diagram illustrating a configuration example of the control circuit 300 of FIG. As shown in FIG. 3, the nozzle row configured in the recording head 102 </ b> H is divided into N groups, for example, 32 pieces each from one end portion to the other end portion thereof. Therefore, in FIG. 3, the recording head 102 </ b> H has 32 × N nozzles. Further, the control circuit 300 controls ejection from the nozzles so that printing is performed by block division driving.

  The control circuit 300 includes a 32 × N-bit shift register 303, a 32 × N-bit latch circuit 304, a block selection circuit 305, a driver circuit 301 for each group, and an AND circuit 302.

  The shift register 303 receives the image signal (DATA) and the clock signal (DCLK) from the controller 200, and holds the image signal (DATA) input serially in synchronization with the clock signal (DCLK). The latch circuit 304 receives the latch signal (LATCH) from the controller 200 and latches the image signal (DATA) held in the shift register 303 according to the latch signal (LATCH). The latched image signal (DATA) becomes a nozzle selection signal for selecting a nozzle to be used.

The block selection circuit 305 receives 4-bit block selection signals (BENB0 to 3) that are binary values from the controller 200. A signal (Block 0 to 15) designating one of 16 blocks (Block 0 to 15) is generated and output to the AND circuit 302 by a combination of the state of each bit of the block selection signals BENB 0 to 3. If the reference numerals “Seg. 1”, “Seg. 2”,... Are attached from one end of the nozzles configured on the recording head 102H, the control circuit 300 is configured so that the nozzles are blocked as follows. Wired above.
Block 0 (Block 0): Seg. 32k + 1, Seg. 32k + 2
Block 1 (Block 1): Seg. 32k + 3, Seg. 32k + 4
Block 2 (Block 2): Seg. 32k + 5, Seg. 32k + 6
Block 3 (Block 3): Seg. 32k + 7, Seg. 32k + 8
Block 4 (Block 4): Seg. 32k + 9, Seg. 32k + 10
Block 5 (Block 5): Seg. 32k + 11, Seg. 32k + 12
Block 6 (block 6): Seg. 32k + 13, Seg. 32k + 14
Block 7 (Block 7): Seg. 32k + 15, Seg. 32k + 16
Block 8 (block 8): Seg. 32k + 17, Seg. 32k + 18
Block 9 (block 9): Seg. 32k + 19, Seg. 32k + 20
Block 10 (Block 10): Seg. 32k + 21, Seg. 32k + 22
Block 11 (Block 11): Seg. 32k + 23, Seg. 32k + 24
Block 12 (Block 12): Seg. 32k + 25, Seg. 32k + 26
Block 13 (Block 13): Seg. 32k + 27, Seg. 32k + 28
Block 14 (block 14): Seg. 32k + 29, Seg. 32k + 30
Block 15 (block 15): Seg. 32k + 31, Seg. 32k + 32
Here, k is an integer of 0 to (N-1) (where N is an integer of 2 or more). Further, the pulse signal (ODD) and the pulse signal (EVEN) (the two signals are also referred to as even / odd selection signals) are wired on the control circuit 300 so as to select the nozzle as described below.
ODD: Seg. 32k + (2m + 1)
EVEN: Seg. 32k + (2m + 2)
Here, m is an integer of 0-15. Therefore, by combining the block selection signal and the even / odd selection signal, the nozzle group can be divided into 16 small blocks to select the nozzles. The heat pulse signal (HENB) input from the controller 200 is connected to the AND circuit 302 so as to be input to all the nozzles of the recording head 102H.

  FIG. 4 is a time chart showing changes in various signals supplied from the controller 200 to the recording head 102H. In FIG. 4, as “event 1” and “event 2”, signal waveforms for two periods of the recording operation are shown. As shown in FIG. 4, the recording operation of one cycle is divided into 16 blocks by the block selection signals (BENB0 to 3) and the even / odd selection signals (ODD, EVEN). Further, the image signal (DATA) transferred at “event 1” is validated by the latch signal (LATCH) of “event 2”.

  As described above, the inkjet recording apparatus 100 selects the nozzle to be driven based on the nozzle selection signal, and determines the driving timing of the nozzle group to be driven simultaneously based on the block selection signal and the even / odd selection signal. Further, the voltage VH applied to each nozzle is controlled by supplying a heat pulse signal in synchronization with the block selection signal and the even / odd selection signal.

  FIG. 5 is a diagram showing the nozzles of the ODD row (nozzle row selected by ODD) arranged in the recording head 102H and the positions of the ink droplets on the recording medium when the recording head 102H is scanned. In the drawing, the horizontal direction is the main scanning direction (x direction in FIG. 1) of the recording head, and the vertical direction is the sub scanning direction, that is, the conveyance direction of the recording medium (y direction in FIG. 1). Each nozzle number (also referred to as a segment number) corresponds to the number assigned to the nozzle in FIG. The nozzles are arranged at equal intervals with a pixel interval d in the sub-scanning direction, and are driven at the same time with a period of 16 pixels in the sub-scanning direction with respect to the recorded image. Here, an example is shown in which the nozzles are driven in order from the nozzle row end, but any nozzle may be driven in what order. Further, the order of nozzles to be driven may be dispersed based on a predetermined drive order table.

[First Embodiment]
FIG. 6 is a diagram showing the nozzle arrangement of the recording head of the first example according to the first embodiment of the present invention. In this example, the recording head 102H is a recording head in which two nozzle rows that eject ink of the same color are arranged symmetrically. That is, as shown in FIG. 6, the nozzle rows 601 and 608 are nozzle rows that discharge the same ink, and are arranged symmetrically across the center. Also, the nozzle rows 602 and 607 are nozzle rows that eject the same ink, and are arranged symmetrically with the center in between. Further, the nozzle rows 603 and 606 are nozzle rows that eject the same ink, and are arranged symmetrically with respect to the center. The nozzle rows 604 and 605 are nozzle rows that eject the same ink, and are arranged symmetrically across the center.

  FIG. 16 is a diagram showing a conventional method for assigning print data when the print head shown in FIG. 6 is used. FIG. 16 shows a state in which input recording data is represented in units of columns. In other words, the recording data is represented by four columns: the first column of recording data (I_Clm1), the second column of recording data (I_Clm2), the third column of recording data (I_Clm3), and the fourth column of recording data (I_Clm4). ing. Here, the column is a unit of print data corresponding to the ODD row or EVEN row (nozzle row selected by EVEN) of each group of nozzles shown in FIG. For example, the print data corresponding to 16 nozzles in the ODD row shown in FIG. 5 is the print data for one column. In FIG. 16, one column is represented by a block number in order to include both the ODD column and the EVEN column. Further, in FIG. 16, the recording data in units of four columns are shown side by side so as to correspond with the block numbers.

  Conventionally, the first column (I_Clm1) of the recording data is assigned to the first column (NA_Clm1) of the nozzle row 601. Further, the second column (I_Clm2) of the recording data is assigned to the first column (NB_Clm1) of the nozzle row 608. The third column (I_Clm3) of the recording data is assigned to the second column (NA_Clm2) of the nozzle row 601. Further, the fourth column (I_Clm4) of the recording data is assigned to the second column (NB_Clm2) of the nozzle row 608.

  FIG. 7 is a diagram showing a recording data allocation method in this example. In this example, first, the first half part and the second half part of the first column (I_Clm1) of the recording data and the second column (I_Clm2) of the recording data according to the nozzle drive order of the reference nozzle row (nozzle row 601). Divide into two. In this example, as shown in FIG. 5, consider an example in which the nozzles are driven in order from the end. Accordingly, when the first column (I_Clm1) of the print data is divided into two according to the driving order of the reference nozzle row (nozzle row 601), the first half (Block 0 to 7) and the second half (Block 8 to 15). Will be divided into Similarly, the second column (I_Clm2) of the recording data is divided into the first half part (Block 0 to 7) and the second half part (Blocks 8 to 15) according to the driving order of the reference nozzle row (nozzle row 601).

  Next, the nozzle row 601 and the nozzle row 608 are divided into two parts, a first half part and a second half part, according to the nozzle drive order. In this example, since the nozzle is driven in order from the end, it is divided into the first half (nozzles 1 to 8) and the second half (nozzles 9 to 16).

  Next, the first half of the first column (I_Clm1) of the print data is assigned to the first half of the nozzle row 601 and the second half of the first column (I_Clm1) of the print data is assigned to the second half of the nozzle row 608. Next, the first half of the second column (I_Clm2) of the print data is assigned to the first half of the nozzle row 608, and the second half of the second column (I_Clm2) of the print data is assigned to the second half of the nozzle row 601.

  Next, print data is transferred to each nozzle row using the function of the ASIC 203 shown in FIG. That is, the first half of the first column (I_Clm1) and the second half of the second column (I_Clm2) of the print data are transferred to the nozzle row 601 according to the driving order of the nozzle row 601 (sequential drive in this embodiment). . Similarly, the latter half of the first column (I_Clm1) and the first half of the second column (I_Clm2) of the recording data are transferred to the nozzle row 608 according to the driving order of the nozzle row 608 (sequential driving in this embodiment). To do. Recording is performed with each nozzle row.

  Further, the first half portion and the second half portion of the third column (I_Clm3) of the print data and the fourth column (I_Clm4) of the print data are similarly determined in accordance with the nozzle drive order of the nozzle row (nozzle row 601) serving as a reference. Divide into two. That is, the third column (I_Clm3) of the recording data is divided into the first half (Block 0 to 7) and the second half (Blocks 8 to 15) according to the driving order of the reference nozzle row (nozzle row 601). The fourth column (I_Clm4) of the recording data is divided into the first half (Block 0 to 7) and the second half (Blocks 8 to 15) according to the driving order of the reference nozzle row (nozzle row 601).

  Next, print data is transferred to each nozzle row using the function of the ASIC 203 shown in FIG. That is, the first half of the third column (I_Clm3) and the second half of the fourth column (I_Clm4) of the recording data are transferred to the nozzle row 601 according to the driving order of the nozzle row 601 (sequential drive in this embodiment). . Similarly, the second half of the third column (I_Clm3) and the first half of the fourth column (I_Clm4) of the recording data are transferred to the nozzle row 608 according to the driving order of the nozzle row 608 (sequential driving in this embodiment). To do. Recording is performed with each nozzle row.

  Thereafter, the first half of the third column (I_Clm3) of the recording data is assigned to the first half of the nozzle row 601 and the second half of the third column (I_Clm3) of the recording data is assigned to the second half of the nozzle row 608. Next, the first half of the fourth column (I_Clm4) of the print data is assigned to the first half of the nozzle row 608, and the second half of the fourth column (I_Clm4) of the print data is assigned to the second half of the nozzle row 601.

  Here, the difference between the conventional example and this example will be described with reference to FIGS. 8A to 8C.

  8A to 8C are diagrams showing the arrangement of dots recorded on the recording medium as a result of scanning the recording head 102H from the left to the right in the drawing. FIG. 8A shows a case in which one column of recording data for one column is used. As shown in FIG. 8A, the recording data for one column is recorded with a driving resolution of 600 dpi.

  In general, a plurality of recording heads are often used to improve the carriage speed. As shown in FIG. 8B, the drive start position of each nozzle row is shifted as shown in FIG. 8B using two rows of print heads, and printing is performed by assigning print data as described in FIG. That is, even if the carriage speed is double that in the case of FIG. 8A, the resolution of 600 dpi can be maintained by shifting the nozzle drive start position in the nozzle row 608 by half the number of nozzles in the nozzle row 601. However, as shown in FIG. 8B, the width of the recording data for one column is doubled as compared with the case of FIG. 8A, which causes deterioration of vertical ruled lines and character quality.

  Here, in this example, print data is assigned to each nozzle row as shown in FIG. FIG. 8C shows a recorded dot arrangement when recording data is allocated as shown in FIG. 7 and the carriage speed is the same as that in FIG. 8B, that is, when double the speed of FIG. 8A. In FIG. 8C, recording data is assigned to the nozzle rows 601 and 608 as shown in FIG. In addition, scanning is started with the drive start timings of the nozzle 1 of the nozzle row 601 and the nozzle 9 of the nozzle row 608 being the same. When a half cycle of the nozzle drive cycle of the nozzle row 601 has elapsed, scanning is performed with the drive start timings of the nozzle 9 of the nozzle row 601 and the nozzle 1 of the nozzle row 608 being the same. That is, in this example, the drive start positions of the nozzle rows 601 and 608 are the same, and the nozzle drive timing of the nozzle row 608 is shifted by a half cycle. As a result, as shown in FIG. 8C, the width of the recording data for one column becomes the same as that in FIG. 8A, and it is possible to prevent deterioration of vertical ruled lines and character quality as shown in FIG. 8B.

  Next, a second example in which four nozzle rows are used will be described.

  FIG. 9 is a diagram showing the nozzle arrangement of the recording head when the number of nozzle rows used is four. As shown in FIG. 9, four nozzle rows that eject the same ink are arranged symmetrically with the center in between. That is, as shown in FIG. 9, the two nozzle rows 901 and 908 are arranged symmetrically with the center in between. Further, the two nozzle rows 902 and 907 are arranged symmetrically across the center. Further, the two nozzle rows 903 and 906 are arranged symmetrically with respect to the center. Further, the two nozzle rows 904 and 905 are arranged symmetrically with respect to the center.

  FIG. 17 is a diagram showing a conventional method for assigning print data when the print head shown in FIG. 9 is used. In FIG. 17, the nozzle row 901 is shown as nozzle row A and nozzle row B, and the nozzle row 908 is shown as nozzle row C and nozzle row D. As shown in FIG. 17, the first column (I_Clm1) of the recording data is assigned to the first column (NA_Clm1) of the nozzle array A. The second column (I_Clm2) of the recording data is assigned to the first column (NB_Clm1) of the nozzle row B. The third column (I_Clm3) of the recording data is assigned to the first column (NC_Clm1) of the nozzle row C. The fourth column (I_Clm4) of the recording data is assigned to the first column (ND_Clm1) of the nozzle row D.

  FIG. 10 is a diagram showing a recording data allocation method in this example. First, the first column (I_Clm1) of the recording data is divided into four sections 1, 2, 3, and 4 according to the nozzle drive order in the reference nozzle row A. Since the nozzle drive order in the nozzle row is the same as that in the case where the number of nozzle rows to be used is two, division 1 (Block 0 to 3), division 2 (Block 4 to 7), division 3 (Block 8 to 11) and This is divided into four sections 4 (Blocks 12 to 15). Similarly, the second column (I_Clm2), the third column (I_Clm3), and the fourth column (I_Clm4) of the recording data are also divided into four. Next, the nozzle rows A to D are divided into four according to the nozzle driving order. In this example, since the example which drives a nozzle in order from an edge part is considered, division 1 (nozzles 1-4), division 2 (nozzles 5-8), division 3 (nozzles 9-12), and division 4 Divide into four (nozzles 13 to 16).

  In this example, the section 1 of the first column (I_Clm1) of the recording data is assigned to the section 1 of the first column of the nozzle array A. In addition, section 2 of the first column (I_Clm1) of the recording data is assigned to section 2 of the first column of nozzle row B. Further, the section 3 of the first column (I_Clm1) of the recording data is assigned to the section 3 of the first column of the nozzle array C. Further, the section 4 of the first column (I_Clm1) of the recording data is assigned to the section 4 of the first column of the nozzle array D.

  Next, section 2 of the second column (I_Clm2) of the recording data is assigned to section 2 of the first column of nozzle array A. Also, the section 3 of the second column (I_Clm2) of the recording data is assigned to the section 3 of the first column of the nozzle row B. Further, the section 4 of the second column (I_Clm2) of the recording data is assigned to the section 4 of the first column of the nozzle array C. Also, section 1 of the second column (I_Clm2) of the recording data is assigned to section 1 of the first column of nozzle row D.

  Next, section 3 of the third column (I_Clm3) of the recording data is assigned to section 3 of the first column of nozzle array A. In addition, the section 4 of the third column (I_Clm3) of the recording data is assigned to the section 4 of the first column of the nozzle row B. Also, section 1 of the third column (I_Clm3) of the recording data is assigned to section 1 of the first column of nozzle array C. In addition, the section 2 of the third column (I_Clm3) of the recording data is assigned to the section 2 of the first column of the nozzle array D.

  Finally, section 4 of the fourth column (I_Clm4) of the recording data is assigned to section 4 of the first column of nozzle array A. Also, section 1 of the fourth column (I_Clm4) of the recording data is assigned to section 1 of the first column of nozzle row B. In addition, the section 2 of the fourth column (I_Clm4) of the recording data is assigned to the section 2 of the first column of the nozzle array C. Further, the section 3 of the fourth column (I_Clm4) of the recording data is assigned to the section 3 of the first column of the nozzle array D.

  Next, print data is transferred to each nozzle row using the function of the ASIC 203 shown in FIG. In other words, the first column (I_Clm1), the first column (I_Clm2), the second column (I_Clm2), the third column (I_Clm3), the third column (I_Clm4), the fourth column (I_Clm4), The data is transferred to the nozzle row A according to the driving order (sequential driving in this embodiment). Similarly, section 2 of the first column (I_Clm1), section 3 of the second column (I_Clm2), section 4 of the third column (I_Clm3), section 1 of the fourth column (I_Clm4), and nozzle array B Are transferred to the nozzle row B in accordance with the driving order (sequential driving in this embodiment). Similarly, the section 3 of the first column (I_Clm1), the section 4 of the second column (I_Clm2), the section 1 of the third column (I_Clm3), the section 2 of the fourth column (I_Clm4), and the nozzle array C Are transferred to the nozzle row C in accordance with the driving order (sequential driving in this embodiment). Similarly, the classification 4 of the first column (I_Clm1), the classification 1 of the second column (I_Clm2), the classification 2 of the third column (I_Clm3), the classification 3 of the fourth column (I_Clm4), and the nozzle array D Are transferred to the nozzle row D in accordance with the driving order (sequential driving in this embodiment). Recording is performed with each nozzle row.

  Here, the difference between the conventional example and this example will be described with reference to FIGS. 11A to 11C. 11A to 11C are diagrams illustrating dot arrangements recorded on a recording medium as a result of scanning the recording head 102H from left to right in the drawing. FIG. 11A shows a case where one column of recording data for one column is used. As shown in FIG. 11A, recording data for one column is recorded with a driving resolution of 600 dpi.

  As shown in FIG. 11B, recording is performed using four rows of recording heads and recording data is allocated as described in FIG. In other words, even if the carriage speed is four times that in the case of FIG. 11A, the resolution of 600 dpi is reduced by shifting the nozzle drive start positions in the nozzle rows B, C, and D by ¼ with respect to the number of nozzles in the nozzle row A. Can be maintained. However, as shown in FIG. 11B, the width of the recording data for one column is four times that in the case of FIG. 11A, causing deterioration of vertical ruled lines and character quality.

  Here, in this example, print data is assigned to each nozzle row as shown in FIG. FIG. 11C shows a recorded dot arrangement when print data is allocated as shown in FIG. 10 and the carriage speed is the same as that in FIG. 11B, that is, when the print speed is four times that of FIG. 11A. In FIG. 11C, recording data is assigned to the nozzle arrays A to D as shown in FIG. Further, scanning is started at the same drive start timing of the nozzle 1 of the nozzle row A, the nozzle 5 of the nozzle row B, the nozzle 9 of the nozzle row C, and the nozzle 13 of the nozzle row D. When a quarter of the nozzle drive cycle has elapsed after the start of scanning, the drive start timings of the nozzle 5 in the nozzle row A, the nozzle 9 in the nozzle row B, the nozzle 13 in the nozzle row C, and the nozzle 1 in the nozzle row D are the same. To continue scanning. Further, when a quarter of the nozzle driving period has elapsed, scanning is performed with the drive start timings of the nozzle 9 in the nozzle row A, the nozzle 13 in the nozzle row B, the nozzle 1 in the nozzle row C, and the nozzle 5 in the nozzle row D being the same. Continue. Further, when a quarter of the nozzle driving period has elapsed, scanning is performed with the drive start timings of the nozzle 13 in the nozzle row A, the nozzle 1 in the nozzle row B, the nozzle 5 in the nozzle row C, and the nozzle 9 in the nozzle row D being the same. Continue. That is, in this example, the drive start positions of the nozzle rows A to D are the same, and the nozzle drive timing is shifted by ¼ period. As a result, as shown in FIG. 11C, the width of the recording data for one column becomes the same as that in FIG. 11A, and vertical ruled lines and deterioration of character quality can be prevented as in FIG. 11B.

  As described above, in the present embodiment, each nozzle row group (the above-mentioned “section”) is used to print print data corresponding to each nozzle row of the print head using two or four nozzle rows. The print data divided so as to correspond to the same or the like is distributed and assigned to two or four nozzle rows. After that, for each print data corresponding to each nozzle row, the ink dots ejected from the nozzle with the earliest drive order in each assigned group are recorded on the print medium in the direction perpendicular to the scan direction of the print head. In this way, nozzle drive control is performed.

  Moreover, although the example in the case where the nozzle row to be used is 2 rows and 4 rows was shown above, the number of nozzle rows is not limited to this. For example, the nozzle rows to be used are M rows (M is a divisor of the number of nozzles N. N is a natural number of 2 or more). In that case, first, N / M nozzles in each nozzle row are divided into first to Mth groups (grouping). Next, the print data corresponding to each nozzle row is divided into first to Mth print data corresponding to the first to Mth divisions. The divided print data is distributed and assigned to the first to Mth nozzle rows so that print data corresponding to each nozzle row of the printhead is printed using the first to Mth nozzle rows.

  In the above description, for the sake of simplicity, an example in which the nozzles are sequentially driven from the end of the nozzle row has been described. However, any nozzle may be driven in what order. Further, the order of nozzles to be driven may be dispersed based on a predetermined drive order table.

[Second Embodiment]
A second embodiment will be described. FIG. 12 is a diagram showing a recording data allocation method according to the first example of this embodiment. As in the first embodiment, an example of sequential driving in which driving is performed sequentially from the nozzles at the end will be described.

  The method for dividing the print data and the nozzle array is the same as described in the first embodiment. This embodiment is different from the first embodiment in a method for assigning divided print data to each nozzle row.

  FIG. 12 is a diagram showing a method for assigning print data to nozzle rows in this example. The first half of the first column (I_Clm1) of the recording data is assigned to the first half of the first column of the nozzle row 601. Further, the latter half of the first column (I_Clm1) of the recording data is assigned to the latter half of the first column of the nozzle row 608. Also, the first half of the second column (I_Clm2) of the recording data is assigned to the first half of the second column of the nozzle row 608. Further, the latter half of the second column (I_Clm2) of the recording data is assigned to the latter half of the first column of the nozzle row 601.

  The first half of the third column (I_Clm3) of the print data is assigned to the first half of the second column of the nozzle row 601 and the second half of the third column (I_Clm3) of the print data is assigned to the second half of the second column of the nozzle row 608. Assign to a part. Also, the first half of the fourth column (I_Clm4) of the print data is assigned to the first half of the third column of the nozzle row 608, and the second half of the fourth column (I_Clm4) of the print data is assigned to the second column of the nozzle row 601. Assign to the second half of

  As described above, after assigning the recording data, Null data that does not record anything on the recording medium is assigned to the first half of the first column of the nozzle row 608 and the second half of the third column of the nozzle row 608. .

  Next, print data is transferred to each nozzle row using the function of the ASIC 203 shown in FIG. That is, the first half of the first column (I_Clm1) and the second half of the second column (I_Clm2) of the print data are transferred to the nozzle row 601 according to the driving order of the nozzle row 601 (sequential drive in this embodiment). . Similarly, the latter half of the first column (I_Clm1) of the print data is transferred to the nozzle row 608 in accordance with the drive order of the nozzle row 608 (sequential drive in this embodiment). At that time, Null data is put in the first half and transferred. Recording is performed with each nozzle row.

  Next, the first half of the third column (I_Clm3) and the second half of the fourth column (I_Clm4) of the recording data are transferred to the nozzle row 601 in accordance with the drive order of the nozzle row 601 (sequential drive in this embodiment). To do. Similarly, the first half of the second column (I_Clm2) and the second half of the third column (I_Clm3) of the recording data are transferred to the nozzle row 608 according to the driving order of the nozzle row 608 (sequential driving in this embodiment). To do.

  Next, the first half of the fourth column (I_Clm4) is transferred to the nozzle row 608 in accordance with the driving order of the nozzle row 608 (sequential driving in this embodiment). At that time, Null data is inserted in the latter half and transferred. Recording is performed with each nozzle row.

  13A to 13C are diagrams illustrating dot arrangements recorded on the recording medium as a result of scanning the recording head 102H from the left to the right in the drawing in this example. 13A and 13B are the same as those in FIGS. 8A and 8B.

  In this example, the shift of the drive start position between the nozzle row 601 and the nozzle row 608 can be the same as that in the conventional example shown in FIG. 13B, and the nozzle drive timings of the nozzle rows 601 and 608 are the first. It is not necessary to shift by half a period as in the embodiment. That is, it is only necessary to sequentially drive from the nozzle 1 in each nozzle row.

  Although not shown in FIG. 17C, the nozzle row 608 is sequentially driven from the nozzle 1. Here, as shown in FIG. 12, Null data is stored in the nozzles 1 to 8 of the nozzle row 608, so nothing is recorded and recording is performed from the nozzle 9. When the recording of the nozzle 9 of the nozzle row 608 starts, the recording starts from the nozzle 1 of the nozzle row 601 (601 driving start position in FIG. 13C).

  The state of dot recording on the recording medium is the same as that in FIG. 8 in the first embodiment.

  Next, a second example in which four nozzle rows are used will be described.

  FIG. 14 is a diagram showing a recording data allocation method according to the first example of this embodiment. As in the first embodiment, an example of sequential driving in which driving is performed sequentially from the nozzles at the end will be described.

  The method for dividing the print data and the nozzle array is the same as described in the first embodiment. This embodiment is different from the first embodiment in a method for assigning divided print data to each nozzle row.

  FIG. 14 is a diagram showing a method for assigning print data to nozzle rows in this example.

  Section 1 of the first column (I_Clm1) of the recording data is assigned to section 1 of the first column of nozzle array A. Further, the section 2 of the first column (I_Clm1) of the recording data is assigned to the section 2 of the first column of the nozzle array B. Further, the section 3 of the first column (I_Clm1) of the recording data is assigned to the section 3 of the first column of the nozzle array C. Further, the section 4 of the first column (I_Clm1) of the recording data is assigned to the section 4 of the first column of the nozzle array D.

  Next, section 1 of the second column (I_Clm2) of the print data is assigned to section 1 of the second column of nozzle array D. In addition, the section 2 of the second column (I_Clm2) of the recording data is assigned to the section 2 of the first column of the nozzle array A. Also, the section 3 of the second column (I_Clm2) of the recording data is assigned to the section 3 of the first column of the nozzle array B. Further, the section 4 of the second column (I_Clm2) of the recording data is assigned to the section 4 of the first column of the nozzle array C.

  Next, section 1 of the third column (I_Clm3) of the recording data is assigned to section 1 of the second column of nozzle array C. In addition, section 2 of the third column (I_Clm3) of the recording data is assigned to section 2 of the second column of nozzle array D. Also, the section 3 of the third column (I_Clm3) of the recording data is assigned to the section 3 of the first column of the nozzle array A. Further, the section 4 of the third column (I_Clm3) of the recording data is assigned to the section 4 of the first column of the nozzle array B.

  Next, section 1 of the fourth column (I_Clm4) of the recording data is assigned to section 1 of the second column of nozzle row B. Further, the second column (I_Clm4) of the print data is assigned to the second column of the nozzle row C. Further, the section 3 of the fourth column (I_Clm4) of the recording data is assigned to the section 3 of the second column of the nozzle array D. Further, the section 4 of the fourth column (I_Clm4) of the recording data is assigned to the section 4 of the first column of the nozzle array A.

  As described above, after allocating the recording data, Null data in which nothing is recorded on the recording medium is allocated to the portion where the recording data of the first and second columns of the nozzle rows B to D are not allocated. .

  Next, print data is transferred to each nozzle row using the function of the ASIC 203 shown in FIG. That is, the first column (I_Clm1) of the recording data, the first column (I_Clm2), the second column (I_Clm2), the third column (I_Clm3), the third column (I_Clm3), the fourth column, the fourth column, and the fourth column 4 In this embodiment, the nozzles are transferred to the nozzle row A according to the sequential driving. Similarly, the division 2 of the first column (I_Clm1), the division 3 of the second column (I_Clm2), and the division 4 of the third column (I_Clm3) are sequentially driven in the driving order of the nozzle row B (in this embodiment, sequentially). ) To the nozzle row B. At that time, Null data is put into the category 1 and transferred. Similarly, the section 3 of the first column (I_Clm1) and the section 4 of the second column (I_Clm2) of the recording data are transferred to the nozzle array C according to the driving order of the nozzle array C (sequential driving in this embodiment). To do. At that time, Null data is put into the sections 1 and 2 and transferred. Similarly, the classification 4 of the first column (I_Clm1) of the print data is transferred to the nozzle row D according to the driving order of the nozzle row D (sequential drive in this embodiment). At that time, Null data is put in the sections 1, 2, and 3 and transferred. Recording is performed with each nozzle row.

  Next, the section 1 of the fourth column of the print data is transferred to the nozzle row B according to the driving order of the nozzle row B (sequential driving in this embodiment). Similarly, the division 2 of the first column (I_Clm1), the division 3 of the second column (I_Clm2), and the division 4 of the third column (I_Clm3) are sequentially driven in the driving order of the nozzle row B (in this embodiment, sequentially). ) To the nozzle row B. At that time, Null data is put in the divisions 2, 3, and 4 and transferred. Similarly, section 1 of the third column (I_Clm3) of recording data and section 2 of the fourth column (I_Clm4) are transferred to the nozzle array C in accordance with the driving order of the nozzle array C (sequential driving in this embodiment). To do. At that time, Null data is put into the sections 3 and 4 and transferred. Similarly, section 1 of the second column (I_Clm2) of the recording data, section 2 of the third column (I_Clm3), section 3 of the fourth column (I_Clm4) are driven in the driving order of the nozzle array D (sequential drive in this embodiment). ) To the nozzle row D. At that time, Null data is put in the category 4 and transferred. Recording is performed with each nozzle row.

  15A to 15C are diagrams showing dot arrangements recorded on a recording medium as a result of scanning the recording head 102H from the left to the right in the figure in this example. 15A and 15B are the same as those in FIGS. 11A and 11B.

  In this example, the deviation of the driving start position between the nozzle arrays A to D can be made the same as in the conventional example shown in FIG. 15B, and each nozzle driving timing of the nozzle arrays A to D is the first implementation. It is not necessary to shift by 1/4 period like the form. That is, it is only necessary to sequentially drive from the nozzle 1 in each nozzle row.

  Although not shown in FIG. 15C, the nozzle rows B to D are sequentially driven from the nozzle 1. Here, since Null data is stored in the nozzle rows B to D as shown in FIG. 14, nothing is recorded. That is, the nozzle row D is recorded from the nozzle 13. When the recording of the nozzle 13 of the nozzle row D starts, the recording starts from the nozzle 9 of the nozzle row C. Further, when the recording of the nozzle 9 of the nozzle row C starts, the recording starts from the nozzle 5 of the nozzle row B. Furthermore, when the recording of the nozzle 5 in the nozzle row B starts, the nozzle row A starts recording from the nozzle 1 (A drive start position in FIG. 15C).

  In the above description, for the sake of simplicity, an example in which the nozzles are sequentially driven from the end of the nozzle row has been described. However, any nozzle may be driven in what order. Further, the order of nozzles to be driven may be dispersed based on a predetermined drive order table.

  The state of dot recording on the recording medium is the same as that in FIG. 11 in the first embodiment.

Claims (3)

A recording head having first to Mth nozzle rows (N is a divisor of N) having N (N is a natural number of 2 or more) nozzles that eject ink of the same color; An inkjet recording apparatus that performs scanning on a recording medium by scanning in a direction intersecting with the arrangement direction of N, and driving N nozzles of each nozzle row in a predetermined driving order,
Grouping means for grouping N nozzles of each nozzle row into N-M groups in N / M units according to the driving order;
A dividing unit that divides print data corresponding to each nozzle row into first to Mth print data corresponding to the first to Mth groups;
The first to Mth groups corresponding to the first to Mth groups divided by the dividing unit so as to record the recording data corresponding to each nozzle row using the first to Mth nozzle rows. Allocating means for distributing and allocating the recording data to the first to Mth nozzle rows,
For each print data corresponding to each nozzle row, the ink dots ejected from the nozzle with the earliest drive order in each group assigned by the assigning unit are related to the direction orthogonal to the scan direction of the print head on the print medium. An ink jet recording apparatus comprising: drive control means for controlling driving of the nozzles so as to overlap and record.   2. The ink jet recording apparatus according to claim 1, wherein the N nozzles of each nozzle row are driven in order from the nozzles located at the end of the nozzle row. A recording head having first to Mth nozzle rows (N is a divisor of N) having N (N is a natural number of 2 or more) nozzles that eject ink of the same color; This is a nozzle drive control method executed in an ink jet recording apparatus that scans in a direction intersecting with the arrangement direction and drives N nozzles in each nozzle row in a predetermined drive order to perform recording on a recording medium. There,
A grouping step in which the grouping means of the inkjet recording apparatus groups N nozzles of each nozzle row into first to Mth groups according to the driving order;
A dividing step in which the dividing unit of the ink jet recording apparatus divides recording data corresponding to each nozzle row into first to Mth recording data corresponding to the first to Mth groups;
The assigning means of the ink jet recording apparatus records the first to Mth divided in the dividing step so as to record the recording data corresponding to each nozzle row using the first to Mth nozzle rows. An assigning step of distributing and assigning the first to Mth print data corresponding to the group to the first to Mth nozzle rows;
For each recording data corresponding to each nozzle row, the drive control means of the ink jet recording apparatus causes the ink dots ejected from the nozzle with the earliest driving order in each group allocated in the allocation step to be recorded on the recording medium. And a drive control step of controlling the drive of the nozzles so as to overlap and record in a direction perpendicular to the scanning direction of the recording head.

Images