JP2001293851A - Method and apparatus for ink jet recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a recording speed without sacrificing an image quality. SOLUTION: A method for ink jet recording comprises the steps of setting a plurality of individual areas (R1 to R6) in an overall area based on print data, deciding a number of passes of main scanning at the set individual areas, and recording at the decided number of the passes. In this case, the setting of the individual areas is conducted by dividing raster data obtained by developing the print data at each window set by dividing the overall area in a rectangular shape, giving a rank at each window divided based on the raster data, and grouping the windows in response to a distributed state of the given rank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet recording method for recording an image on a recording medium by an ink jet recording head, and an ink jet recording apparatus.

[0002]

2. Description of the Related Art An ink jet recording head is provided.
An ink jet recording apparatus that performs recording on a recording medium by scanning the recording head is well known.
This type of ink jet recording apparatus (hereinafter, referred to as a recording apparatus) includes a recording head, a head scanning mechanism for moving the recording head in a main scanning direction, and a recording medium, such as recording paper, which is fed in a paper feeding direction and is subordinate. A paper feed mechanism for scanning is provided, and an image is recorded on a recording medium by repeatedly performing main scanning and sub-scanning of the recording head.

The above-described recording head has a variation that occurs during a mass production process, such as a diameter of a nozzle opening and a shape of a pressure chamber, and there is a problem that the variation causes a discharge ink amount and a landing position to differ for each nozzle opening. Due to this defect, white streaks and color unevenness occur on the image. Therefore, one dot line (one raster) along the main scanning direction is recorded in a plurality of passes using different nozzle openings, that is, in a plurality of main scans. That is being done.

In this type of printing apparatus, a plurality of types of printing modes such as a "fast mode" and a "clean mode" are prepared, and the number of passes, that is, the main mode for printing one dot line, is set for each printing mode. The number of scans is determined.
For example, in the "fast mode", one dot line is printed in one pass, and in the "clean mode", one dot line is printed in four passes.

[0005]

As described above, the conventional recording apparatus has a configuration in which the number of passes required for recording one dot line is set for each recording mode. Therefore, if the number of passes is increased, the image quality is improved. Although the recording speed is reduced, the recording speed is reduced. On the other hand, in order to improve the recording speed, the number of passes must be reduced, and in this case, the image quality is impaired. In short, in the conventional recording apparatus, it is necessary to select either to prioritize the recording speed and sacrifice the image quality or to prioritize the image quality and sacrifice the recording speed.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ink jet recording method and an ink jet recording apparatus capable of improving a recording speed without sacrificing image quality. .

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above object, and the invention according to claim 1 has a recording head having a nozzle array formed of a plurality of nozzle openings. By repeatedly performing main scanning for ejecting ink droplets while moving the recording medium in a direction orthogonal to the main scanning direction and sub-scanning for moving a recording medium in a direction orthogonal to the main scanning direction, one dot line is formed by different nozzles. In an ink jet recording method for recording by main scanning of a plurality of passes by an opening and recording an image based on print data on a recording medium, a plurality of individual areas are set in the entire area based on the print data, and the set individual areas are set. An ink jet recording method, wherein the number of main scanning passes is selected and determined from different preset numbers of passes for each area, and printing is performed with the determined number of passes. A.

Here, "print data" means data transmitted from a host computer or the like. Also,
The “entire area” means the entire recording area defined by the print data, and the “individual area” refers to an area that is divided based on the conspicuousness of color unevenness or the like due to the variation of each nozzle opening. means.

According to a second aspect of the present invention, in the setting of the individual area, the raster data obtained by expanding the print data is divided for each window set by dividing the entire area into a rectangular shape. And assigning a rank to each window based on the raster data, and setting individual areas by grouping the windows according to the distribution state of the assigned ranks. An ink jet recording method according to claim 1, wherein:

[0010] Here, the "rank" is an index for determining the conspicuousness of unevenness or the like due to the variation of the nozzle openings in window units.

According to a third aspect of the present invention, the window is composed of a plurality of small blocks, and the step of assigning the rank detects the recording density of each block constituting the window based on raster data. And setting a block level according to the recording density for each block based on the detected recording density, and assigning a rank of the window based on the distribution state of the block level. The inkjet recording method according to claim 2, wherein:

Here, the "block level" is an index for indicating the degree of conspicuousness of unevenness or the like caused by variations in nozzle openings.

According to a fourth aspect of the present invention, the setting of the individual area includes a step of dividing the whole area into a lattice so as to surround the image data and setting a plurality of windows, and a step of setting the window of the image data. 2. The method according to claim 1, further comprising the steps of: grouping necessary windows to set an image individual area and setting the remaining windows as text individual areas in order. .

According to a fifth aspect of the present invention, there is provided a recording head having a nozzle row composed of a plurality of nozzle openings, and main scanning for ejecting ink droplets while moving the recording head in a direction intersecting the nozzle row direction. And a printing operation control means for controlling a sub-scan which moves the recording medium in a direction orthogonal to the direction of the main scan, and by repeatedly performing the main scan and the sub-scan, one dot line can be formed with different nozzle openings. In an ink jet recording apparatus that records by using a plurality of passes of main scanning and records an image based on print data on a recording medium, an individual area is set in the entire area based on the print data. Area setting means;
Providing a pass number setting means for selecting the number of main scanning passes for each individual area set by the individual area setting means from a preset different number of passes; and a printing operation control means,
An ink jet recording apparatus characterized in that main scanning and sub-scanning are controlled based on the number of main scanning passes determined by a pass number setting unit.

According to a sixth aspect of the present invention, the individual area setting means divides the raster data obtained by expanding the print data into each window set by dividing the entire area into a rectangular shape. Raster data dividing means, rank assigning means for assigning a rank to each window based on raster data, and grouping means for grouping each window according to the assigned rank distribution state and setting an individual area. The ink jet recording apparatus according to claim 5, comprising:

According to a seventh aspect of the present invention, the window is composed of a plurality of small blocks, and the rank assigning unit detects and detects the recording density of each block constituting the window based on raster data. 7. The ink jet recording apparatus according to claim 6, wherein a block level corresponding to the recording density is set for each block based on the recording density, and a rank is assigned based on a distribution state of the block level.

The invention according to claim 8 is characterized in that the rank assigned by the rank assigning means is a numerical value indicating the number of passes in the main scanning. Device.

According to a ninth aspect of the present invention, the individual area setting means sets an image individual area containing image data and a text individual area consisting of only text data based on print data, and the pass number setting means The ink jet recording apparatus according to claim 5, wherein the number of passes of each individual area is set such that the number of passes of the individual image area is larger than the number of passes of the individual text area.

According to a tenth aspect of the present invention, the individual area setting means includes window setting means for setting a plurality of windows by dividing an entire area into a lattice so as to surround the image data. 10. The ink jet type recording apparatus according to claim 9, wherein necessary windows are grouped together and windows are set to set individual image regions, and the remaining windows are set as individual text regions.

In a preferred embodiment of the present invention, the printing operation control means sets the number of passes at the boundary portion to each other when different numbers of passes are set for the individual areas adjacent in the sub-scanning direction. The inkjet recording apparatus according to any one of claims 5 to 10, wherein the number is changed to a number between the number of passes set in the individual area.

According to a twelfth aspect of the present invention, the printing operation control means is configured to execute an idle operation when a recording area in which ink droplets are ejected and an idle area in which ink droplets are not ejected are mixed in one pass of main scanning. 12. The ink jet recording apparatus according to claim 5, wherein a scanning speed of the recording head in the running area is higher than a scanning speed of the recording head in the recording area.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment. First, a schematic configuration of an ink jet printer 1 (hereinafter, simply referred to as a printer 1), which is a typical ink jet recording apparatus, will be described with reference to FIG.

The illustrated printer 1 has a carriage 4 to which a recording head 2 is attached and which holds an ink cartridge 3 in a replaceable manner. This carriage 4
Is movably attached to a guide member 6 provided on the housing 5, and is reciprocated along the guide member 6 by the head scanning mechanism (that is, along the main scanning direction).

The head scanning mechanism includes a pulse motor 7 provided at one of the left and right ends of the housing 5, a driving pulley 8 connected to the rotating shaft of the pulse motor 7, and a play motor provided at the left and right other ends of the housing 5. The driving pulley 9, the timing belt 10 that is bridged between the driving pulley 8 and the idle pulley 9 and connected to the carriage 4, a control unit 11 (see FIG. 3) that controls the rotation of the pulse motor 7, and the like. It is provided for. That is, the head scanning mechanism reciprocates the carriage 4, that is, the recording head 2, in the width direction of the recording paper 12, which is a kind of print recording medium, by operating the pulse motor 7. Further, the printer 1 includes a recording paper 12
Is provided in a sub-scanning direction orthogonal to the main scanning direction. This paper feed mechanism includes a paper feed motor 1
3, a paper feed roller 14, a control unit 11, and the like. The recording paper 12 is moved in the paper feed direction based on a control signal from the control unit 11.

Next, the configuration of the recording head 2 will be described. The recording head 2 illustrated in FIG. 2 is a recording head 2 including a piezoelectric vibrator 21 in a flexural vibration mode. The recording head 2 includes an actuator unit 23 in which a plurality of pressure chambers 22 are formed, a flow path unit 26 in which a nozzle opening 24 and a common ink chamber 25 are formed, and a piezoelectric vibrator 21.
With. The flow path unit 26 is joined to the front surface of the actuator unit 23, and the piezoelectric vibrator 21 is provided on the back surface of the actuator unit 23.

The recording head 2 has a common ink chamber 25.
A plurality of ink flow paths extending from the nozzle through the pressure chamber 22 to the nozzle opening 24 are formed corresponding to the nozzle opening 24. When a driving voltage is supplied and an electric field acts on the piezoelectric vibrator 21, the piezoelectric vibrator 21 bends so as to protrude toward the pressure chamber 22, and contracts the volume of the pressure chamber 22.
When the supply of the driving voltage is stopped, the electric field does not act, so that the piezoelectric vibrator 21 returns to the steady state, and the contracted pressure chamber 22 also expands. When ejecting ink droplets from the nozzle openings 24, for example, a driving voltage is supplied to rapidly contract the pressure chambers 22. That is, when the pressure chamber 22 is rapidly contracted, an increase in the ink pressure occurs in the pressure chamber 22, and an ink droplet is ejected from the nozzle opening 24 with the increase in the pressure. When the supply of the driving voltage is stopped after the ejection of the ink droplet, the piezoelectric vibrator 21 returns to the original state. As a result, the contracted pressure chamber 22 expands, and ink is supplied from the common ink chamber 25 into the pressure chamber 22 through the ink supply port.

Next, the electrical configuration of the printer 1 will be described. As shown in FIG. 3, the exemplified printer 1 includes a printer controller 31 and a print engine 32.

The printer controller 31 has an interface 33 for receiving print data and the like from a host computer (not shown) and an R for storing various data.
AM 34, ROM 35 storing control routines and the like for various data processing, and control unit 11 including a CPU and the like.
Oscillating circuit 36, a drive signal generating circuit 37 for generating a drive signal to be supplied to the recording head 2, and a print engine 32 for converting raster data (dot pattern data) and drive signals obtained by developing print data And an interface 38 for transmission to the

The interface 33 receives print data including, for example, any one of character codes, graphic functions, and image data or a plurality of data from a host computer or the like. The interface 33 can output a busy (BUSY) signal, an acknowledge (ACK) signal, and the like to the host computer.

The RAM 34 is used as a reception buffer 34a, an intermediate buffer 34b, an output buffer 34c, a work memory (not shown), and the like. The print data from the host computer received by the interface 33 is temporarily stored in the reception buffer 34a. The intermediate buffer 34b stores intermediate code data. The output buffer 34c stores raster data obtained by expanding the intermediate code data.

The ROM 35 stores various control routines executed by the control unit 11, font data, graphic functions, and the like.

The control section 11 functions as print data expanding means, and expands print data from the host computer into raster data. Further, the control unit 11 also functions as an individual area setting unit and a pass number setting unit, and refers to raster data stored in the output buffer 34c to refer to the entire area (two-dimensional map) defined by the raster data. A plurality of individual areas are set therein, and the number of passes (the number of main scans for printing one dot line) is selected and set from a preset number of different passes for each individual area. Further, it also functions as a printing operation control means, and serially transmits the raster data to the recording head 2 or outputs a pulse signal for moving the carriage 4 to the pulse motor 7 according to the set number of passes. Alternatively, a signal for moving the recording paper 12 is output to the paper feed motor 13 so that the main scanning and the sub-scanning are repeatedly performed, and an image is recorded on the recording paper 12.

The print engine 32 includes the electric circuit system 41 of the recording head 2, the paper feed motor 13, and the pulse motor 7. Electric circuit system 4 of recording head 2
1 is a shift register 42 in which raster data is set.
And a latch circuit 43 for latching raster data set in the shift register 42, a level shifter 44 functioning as a voltage amplifier, and a switch circuit 45 for controlling supply of a drive signal to the piezoelectric vibrator 21. As shown in FIG. 4, these shift registers 42 (42a to 42n) and latch circuits 43 (43a to 43a)
43n), a plurality of level shifters 44 (44a to 44n), and a plurality of switch circuits 45 (45a to 45n) are provided corresponding to the respective piezoelectric vibrators 21.

The raster data is print data (SI)
Is transmitted to the recording head 2. That is, this print data is synchronized with the clock signal (CK) from the oscillation circuit 36,
2 is transmitted serially. The print data serially transferred is latched by the latch circuit 43, and the latched print data is boosted by the level shifter 44 to a voltage at which the switch circuit 45 can be driven. The boosted print data is supplied to the switch circuit 45. The drive signal (COM) from the drive signal generation circuit 37 is input to the input side of the switch circuit 45, and the piezoelectric vibrator 21 is electrically connected to the output side of the switch circuit 45.

The print data controls the operation of the switch circuit 45. For example, during a period in which the latched print data is “1”, a voltage signal sufficient to turn on the switch circuit 45 is output from the level shifter 44. The switch circuit 45 is connected by the voltage signal, and a drive signal is supplied to the piezoelectric vibrator 21 to deform the piezoelectric vibrator 21. On the other hand, when the latched print data is “0”, no voltage signal is output from the level shifter 44, so that the switch circuit 45 is in a non-connected state (OFF). In this case, the supply of the drive signal to the piezoelectric vibrator 21 is shut off. Therefore, when a drive signal having a waveform for discharging ink droplets is supplied to the piezoelectric vibrator 21 during a period in which the latched print data is “1”, ink droplets are discharged from the corresponding nozzle openings 24.

Next, the recording operation in the printer 1 having the above configuration will be described. In the following description,
For the sake of convenience, a configuration in which print data is image data, and this print data is developed into one page of raster data and then transmitted to the recording head 2 will be described. / 3 page, 1/4 page, or
When raster data of bands AF to be described later (see FIG. 6) is obtained, the present invention can be similarly applied to a configuration in which the raster data is transmitted to the recording head 2. The following recording operation is performed in one recording mode.

When print data is received from the host computer, the controller 11 creates raster data. That is, the received print data is first stored in the reception buffer 34a of the RAM 34. The control unit 11 reads the print data stored in the reception buffer 34a, converts the print data into intermediate code data, and stores the converted intermediate code data in the intermediate buffer 34b. Control unit 1
Reference numeral 1 decompresses the intermediate code data read from the intermediate buffer 34b into raster data with reference to font data and graphic functions in the ROM 35, and stores the raster data in the output buffer 34c.

After the raster data has been created in this manner, the control unit 11 (individual area setting means) subsequently sets a plurality of individual areas in the entire area which is the entire recording area defined by the print data. Set. The individual area is an area that is divided based on the conspicuousness of unevenness or the like due to the variation of the nozzle openings 24.

The setting of the individual area is performed based on the rank given to the window WD. As shown in FIG. 5A, the window WD is an area set by dividing the entire area into a rectangular shape. For example, if the entire area has a vertical size of A4, This is a rectangular area slightly longer in the horizontal direction, which is divided into three parts in the horizontal direction (corresponding to the main scanning direction) of the whole area and six parts in the vertical direction (corresponding to the sub-scanning direction) of the whole area. Further, each window WD is shown in FIG.
As shown in the figure, the block is composed of a plurality of minute blocks BK. The minute block BK is a region for determining the recording density (duty) of each ink used, and in the present embodiment, is set as a square region composed of 60 pixels × 60 pixels.

Therefore, when setting the individual area, the control unit 11 firstly sets the rank of the number of passes for each window WD, that is, the conspicuousness of unevenness or the like caused by the variation of the nozzle openings 24 on a window basis. An index for expressing with is given. That is, the image recorded in the window WD is weighted as to whether or not the influence of the variation of each nozzle opening 24 is likely to occur, and an index indicating the weight is given.

Therefore, the control unit 11 first functions as a raster data dividing unit, and converts the raster data thus developed into raster data.
Each window WD shown in FIG. 5A is divided.

When the raster data is divided, the control unit 1
1 functions as a rank assigning means. Here, the control unit 11 detects the recording density of each block BK constituting the window WD based on the raster data for the window WD to which the rank is to be assigned. That is, the ink recording ratio (for example, dot formation density) is calculated for each block. For blocks recorded with a plurality of types of inks having different colors and color materials, the recording density is calculated for each type of ink. That is,
It calculates which type of ink and how much ink is ejected in the block.

When the recording density is detected, a block level corresponding to the recording density is set for each block BK based on the detected recording density. The block level is an index for indicating the conspicuousness of unevenness or the like due to the variation of the nozzle openings 24, and has three stages in the present embodiment.
As an example, three levels corresponding to “easy to notice”, “medium”, and “not noticeable” are set.

The leveling is performed by comparing the detected recording density with a reference formula. Regarding the conspicuousness of unevenness or the like, there is a characteristic that the recording density is very low or high, and it is hard to be conspicuous, and the medium density is conspicuous. Therefore, a reference expression such as “recording density = 1% or less” is set, and if applicable, a level indicating “not noticeable” is set. Similarly, a level indicating “inconspicuous” is set even when the reference expression “recording density = 100% or more” is satisfied. On the other hand, "recording density = 1% or more to 30
% Or "recording density = 70% or more to less than 100%", a level indicating "medium" is set, and "recording density = 30% or more to less than 70%"
In the case of the reference expression, a level indicating "conspicuous" is set. Further, there is a characteristic that the degree of conspicuousness such as unevenness differs depending on the color of the ink. For example, light magenta ink is more noticeable such as unevenness than magenta ink or cyan ink. Therefore, the value of the recording density corresponding to each level is appropriately set for each type of ink.

When a block level is set for each block BK, a rank is assigned to the window WD based on the distribution state of the level of each block BK constituting the window WD.

In this case, the rank is set in consideration of the existence ratio of each block level in the window WD to be provided, the distribution state of each block level, and the like. For example, if the presence ratio in the window WD is high, the weight of the block level is increased, and if the presence ratio is low, the weight of the block level is reduced. Also, when the same block level is dense in the window WD, the weight of this block level is increased, and when the same block level is distributed over the entire area in the window WD, the weight of this block level is reduced. .

In the present embodiment, ranks are assigned in correspondence with the most weighted block levels. For example, as shown in FIG. 6, when the block level with the highest weight is a level indicating “conspicuous”, a rank “4” is assigned to this window WD. Similarly, when the block level with the highest weight is a level indicating “medium”, this window WD
Is given a rank “2”, and when the block level indicates “not noticeable”, a rank “1” is given to this window WD.

Note that these ranks are numerical values associated with the number of passes in the main scan. That is, rank "4"
It is optimal to record this window WD in four passes, rank "2" means optimal in two passes, and rank "1" is sufficient to record in one pass. Means that Thus, the window W
By using the number of passes of the main scan as the rank given to D, each window WD can be managed by the number of passes, and processing performed thereafter, for example, setting processing of the number of passes can be simplified. it can.

When a rank is assigned to each window WD, the control unit 11 functions as a grouping unit, and groups each window WD according to the assigned rank distribution state to set an individual area. After that, the control unit 11
Also functions as pass number setting means, and determines the number of passes of main scanning for each set individual area.

In the following description, a group of windows WD adjacent in the main scanning direction will be referred to as a band. Therefore, in the example of FIG. 6, the entire area is composed of six bands including bands A to F, and each band is composed of three windows WD. For convenience of description, a window WD indicated by a reference symbol X is referred to as a first window of a band A and is referred to as a window A1, a window WD indicated by a reference symbol Y is referred to as a third window of a band C and indicated by a window C3, and a reference sign Z Window WD indicated by
Is referred to as a second window of the band E and is indicated by a window E2.

In this embodiment, the setting of the individual area and the setting of the number of main scanning passes for the individual area are performed in band units. In grouping each window WD, which window WD and which window WD
It depends on the way of main scanning whether to group. For example, the windows to be grouped are different between the unidirectional scan and the bidirectional scan. Here, a case in which scanning is performed in one direction from the left side (home position HP side) to the right side in FIG. 6 will be described.

First, the processing of band A will be described.
In the band A, the window A1 on the home position HP side has the rank “1”, the adjacent window A2 has the rank “2”, and the window A3 farthest from the home position HP has the rank “2”. That is, the windows with the rank “2” are arranged in the main scanning direction. For this reason, the control unit 11 (grouping means) groups windows of the same rank. That is, the windows A2 and A3 of the rank “2” are grouped to set one individual area (individual area indicated by a symbol R1 in FIG. 7). Although the remaining window A1 is a single window, it is regarded as a group and one individual region R
Set 2. Then, the control unit 11 functions as an area rank assigning unit, and assigns a rank to each of the individual areas R1 and R2. That is, rank “2” is assigned to the individual region R1, and rank “1” is assigned to the individual region R2.
Is given.

When the individual areas R1 and R2 are set for the band A, the control unit 11 functions as a pass number setting unit and sets the number of passes for each of these individual areas R1 and R2. In the present embodiment, the rank given to each of the individual regions R1 and R2 indicates the number of main scanning passes suitable for printing. Therefore, the control unit 11 (the number of pass setting unit) sets the individual regions R1 and R2 Is recognized and set as the number of passes. If the rank does not indicate the number of passes, the rank may be converted to the number of passes by referring to table information or the like.

When the number of main scanning passes is set for band A, the process for band B is performed. In the band B, the window B1 and the window B2 have the rank “4”, and the window B3 has the rank “1”.
Then, the control unit 11 (grouping means) groups the windows B1 and B2 of rank “4” and sets an individual region R3. The remaining window B3 is also regarded as a group, and one individual region R4 is set. Further, the control unit 11 (area rank assigning unit) assigns a rank “4” to the individual area R3 and assigns a rank “1” to the individual area R2. Each individual area R
When the ranks are assigned to R3 and R4, the control unit 11 (pass number setting means) recognizes and sets the ranks assigned to the individual regions R3 and R4 as the number of passes.

Hereinafter, the processing of the bands C to F is sequentially performed in the same manner. Here, regarding the band D, the window D1 and the window D3 have the rank “1”,
Window D2 is rank “2”. That is, the window of rank “2” is sandwiched between the windows of rank “1”. In such a case, it is conceivable that an individual area is constituted only by the window D2 interposed therebetween. However, a state occurs in which the paper cannot be fed between the previous pass (main scanning) and the next pass, and the efficiency is reduced. It is difficult to make a good record. For this reason, in the present embodiment, the control unit 11 (grouping means) groups the window D1 and the window D2 constituting the band D to set the individual region R5, and sets the rank of the individual region R5 to a higher rank. (Rank with a large number of passes) is set to rank “2”. Also,
The rank “1” is set with the window D3 as the individual region R6. In the present embodiment, the individual area R5 of rank “2” and the individual area R6 of rank “1” are selected with emphasis on image quality.
However, the present invention is not limited to this. For example, three windows D1 to D3 may be grouped into a single individual area as shown in the setting of band E described below, and rank "1" may be set in this individual area to emphasize printing speed. Good.

For the band E, the window E
1, and the window E3 has the rank “2”, and the window E2 has the rank “1”. That is, the window of rank “1” is sandwiched between the windows of rank “2”. In such a case, in the present embodiment, the control unit 11 (grouping means) groups the three windows E1 to E3 constituting the band E and sets a single individual region R6. Then, regarding the rank of the individual region R6, the window E on both sides is used.
Align the rank of window E2 with the rank of 1, E3,
Rank “2” is given.

When the individual area and the number of main scanning passes for the individual area are set as described above, the control unit 11 functions as a printing operation control unit, and based on the determined number of passes. The main scanning and sub-scanning are controlled to record an image on the recording paper 12. The main scanning and the sub-scanning vary depending on the number of passes of the individual areas adjacent in the main scanning direction and the manner of the main scanning, and the patterns thereof are various. Here, some typical examples will be described.

First, a first example will be described with reference to FIGS. In the first example, as shown in FIG. 8, the first individual area on the home position HP side is a one-pass area where the number of passes = “1”, and is separated from the first individual area from the home position HP. The second individual area adjacent to the side is a two-pass area with the number of passes = “2”, and these individual areas are printed solidly by unidirectional scanning from the home position HP side. For convenience of explanation, in the first example, the number of nozzle openings 24 forming the nozzle row is “4”, the upstream end in the paper feeding direction (sub-scanning direction) is the nozzle opening 24 of # 1, and the downstream end is The nozzle opening is # 4. Further, a dot area where dots are formed, that is, an ink droplet landing area has 8 areas in the main scanning direction and 10 areas in the sub-scanning direction.
Area. When indicating a specific dot area, it is represented by a dot area (area number in the main scanning direction, area number in the sub-scanning direction). For example, when indicating the area of the symbol α, the dot area (2, 4) In the case where the area indicated by the symbol β is indicated, it is expressed by the dot area (5, 8).

In starting the recording operation, first, as shown in FIG. 8, the recording head 2 and the recording paper 12 are positioned at the scanning start position. In this scanning start state, the first area of the recording paper 12 in the paper feeding direction and the nozzle opening 24 of # 2, and the second area in the paper feeding direction and the nozzle opening of # 1
4 and the print head 2 is positioned at the first scanning base point P1 (a position closer to the home position HP than the first area in the main scanning direction). After the positioning at the scanning start position, the main scanning of the first pass is performed as shown in FIG. In the first pass of the main scanning, one dot line in the main scanning direction is recorded in one pass in the first individual area, so that eight dot areas, that is, dot areas (1, 1) to (4, 2) are used. A dot is recorded in each area of.
In the second individual area, one dot line in the main scanning direction is recorded in two passes, so that four dot areas (5, 5) selected in a staggered manner (in other words, every other in the main scanning direction). 1), (6,2), (7,1), (8,
2) Record dots.

When the main scanning of the first pass is completed, FIG.
As shown at 0, preparations are made for performing the second pass main scanning.
Here, the paper feed mechanism is operated to feed the paper for two dots, and the recording head 2 is moved (idle-fed) to the home position HP side so that the second scanning base point P2 (on the fourth area in the main scanning direction). Position). When the preparation is completed, the second pass main scanning is performed as shown in FIG. In the second pass main scan, the dot areas (5, 2) and (5) selected in a zigzag manner so as to fill the dot areas not recorded in the first pass main scan with respect to the second individual area.
4), (6,1), (6,3), (7,2), (7,
4) Dots are recorded at (8, 1) and (8, 3). At this time, regarding the first dot area and the second dot area in the sub-scanning direction, the nozzle openings 24 (#
Dots are recorded at nozzle openings 24 (# 3, # 4) different from (1, # 2), and the current dot is recorded between previously recorded dots. This makes the variation of each nozzle opening 24 inconspicuous.

When the main scanning of the second pass is completed, FIG.
As shown in FIG. 2, preparations are made for performing the main scan in the third pass.
That is, the paper is fed by two dots and the recording head 2
At the first scanning base point P1. When the preparation is completed, the main scanning of the third pass is performed as shown in FIG. In the main scan of the third pass, the first individual area
6, dot areas (1, 3) to (4,
6) Dots are recorded in each area. In the second individual area, eight dot areas, that is, the dot areas (5, 3), (5, 5) selected in a zigzag pattern so as to fill the dot areas not recorded in the main scan in the second pass. 5),
(6,4), (6,6), (7,3), (7,5),
Dots are recorded at (8, 4) and (8, 6).

When the main scanning of the third pass is completed, FIG.
As shown in FIG. 4, preparations are made for the main scan of the fourth pass.
That is, the paper is fed by two dots and the recording head 2
At the second scanning base point P2. When the preparation is completed, the main scanning of the fourth pass is performed as shown in FIG. In this main scan, eight dot areas (5, 6), (5, 8), (6) selected in a zigzag manner for the second individual area.
5), (6,7), (7,6), (7,8), (8,
5) Record dots at (8, 7).

When the main scanning of the fourth pass is completed, FIG.
As shown in FIG. 6, preparations are made for performing the main scan in the fifth pass.
That is, the paper is fed by two dots and the recording head 2
At the first scanning base point P1. When the preparation is completed, the main scanning of the fifth pass is performed as shown in FIG. In this main scanning, dots are recorded in the 16 individual dot areas, that is, in each of the dot areas (1, 7) to (4, 10). Further, as for the second individual area, eight dot areas (5, 7) selected in a staggered manner,
(5, 9), (6, 8), (6, 10), (7, 7),
Dots are recorded at (7, 9), (8, 8), and (8, 10).

When the main scanning of the fifth pass is completed, FIG.
As shown in FIG. 8, preparations are made for performing the main scan in the sixth pass.
That is, the paper is fed by two dots and the recording head 2
At the second scanning base point P2. When the preparation is completed, the main scan of the sixth pass is performed as shown in FIG. In this main scanning, four dot regions (5, 10), (6, 9), (7,
For (10) and (8, 9), dots are recorded using the nozzle openings 24 of # 3 and # 4.

As described above, by setting a plurality of individual areas having different numbers of passes in the entire area, the area where the variation among the nozzle openings 24 is conspicuous is set to 4
Since recording is performed by increasing the number of passes such as passes, recording can be performed without deteriorating image quality. Further, in an area where the variation among the nozzle openings 24 is not conspicuous, printing can be performed with a reduced number of passes, so that printing can be performed in a correspondingly short time.

Next, a second example will be described with reference to FIGS. In the second example, the first individual area on the home position HP side is a two-pass area with the number of passes = “2”, and the second individual area adjacent to the first individual area is the number of passes =
Each of these individual areas is solid and printed by bidirectional scanning. Also in this second example, the nozzle openings 24 forming the nozzle row are composed of the nozzle openings 24 of # 1 to # 4. The number of dot areas is eight in the main scanning direction and ten in the sub-scanning direction.

Before starting the recording operation, first, FIG.
As shown in (2), the recording head 2 and the recording paper 12 are positioned at the scanning start position. In this scanning start state, the recording paper 12
No. 1 in the paper feed direction and the nozzle opening 24 of # 1
And the print head 2 is positioned at the first scanning base point P1. After the positioning at the scanning start position, the main scanning of the first pass is performed as shown in FIG. In the first pass main scanning, one dot line in the main scanning direction is printed in two passes for the first individual area.
A dot is recorded in each of the two dot areas (1, 1) and (3, 1). That is, dots are printed in every other selected area in the main scanning direction. In addition, since one dot line in the main scanning direction is printed in four passes for the second individual area, dots are printed in one dot area (5, 1). That is, dots are recorded in every three selected areas in the main scanning direction. Since the second individual area of this embodiment has only four dot areas in the main scanning direction, printing is performed on one dot area.

When the main scanning of the first pass is completed,
As shown in FIG. 2, preparations are made for performing the main scan in the second pass.
Here, the paper feed mechanism is operated to feed the paper for one dot. At this time, the print head 2 moves the scan end position of the first pass (the home position H is higher than the eighth area in the main scanning direction)
P), that is, at the third scanning base point P3. When the preparation is completed, the second pass main scanning is performed. In the main scanning of the second pass, the recording head 2 moves from the third scanning base point P3 to the second scanning base point P2. As a result, main scanning is performed on the second individual area, dots are recorded in the dot area (7, 2) by the nozzle opening 24 of # 1, and
A dot is recorded in the dot area (6, 1) by the nozzle opening 24 of # 2.

When the main scanning of the second pass is completed, FIG.
As shown in 3, preparations are made for performing the third pass of main scanning.
Here, the recording head 2 feeds one dot of paper while waiting at the second scanning base point P2, which is the scanning end position of the second pass. When the preparation is completed, the main scanning of the third pass is performed (FIG. 23). In the main scanning of the third pass, the recording head 2 moves from the second scanning base point P2 to the third scanning base point P3, and the dot area (5, 3) is moved by the nozzle opening 24 of # 1.
The dot is recorded in the dot area (8, 2) by the nozzle opening 24 of # 2, and the dot is recorded in the dot area (7, 1) by the nozzle opening 24 of # 3.

When the main scanning of the third pass is completed, FIG.
As shown in FIG. 4, one dot of paper is fed while the recording head 2 is kept at the third scanning base point P3, which is the scanning end position of the third pass, to prepare for the main scanning of the fourth pass. When the preparation is completed, the main scanning of the fourth pass is performed. In the main scan of the fourth pass, the recording head 2 moves from the third scanning base point P3 to the first scanning base point P1. In the main scanning of the fourth pass, the second individual area is moved in the main scanning direction by three times.
Dots are recorded in every other selected dot area, and the first
In the individual area, dots are recorded in every other selected dot area in the main scanning direction. Specifically, the dot areas (7, 4), (3,
4), dots are recorded in (1, 4), and the dot areas (6, 3), (4, 3),
Dots are recorded in (2,3), and the dot areas (5,2), (3,2), (1,2) are formed by the nozzle opening 24 of # 3
Are recorded in the dot areas (8, 1), (4, 1), and (2, 1) by the nozzle opening 24 of # 4.

When the main scanning of the fourth pass is completed,
As shown in FIG. 5, one dot is fed while the print head 2 is kept at the first scanning base point P1, which is the scanning end position of the fourth pass, and preparations are made for the main scanning of the fifth pass. When the preparation is completed, the main scanning of the fifth pass is performed. In the main scanning of the fifth pass, the recording head 2 moves from the first scanning base point P1 to the third scanning base point P3. And the first
Eight dot areas (1, 3),
(1,5), (2,2), (2,4), (3,3),
Dots are recorded at (3, 5), (4, 2), and (4, 4). For the second individual area, dots are recorded in four dot areas (5, 5), (6, 2), (7, 3), and (8, 4).

When the main scanning of the fifth pass is completed, FIG.
As shown in FIG. 6, preparations are made for the sixth pass of main scanning, and when the preparation is completed, the sixth pass of main scanning is performed. In the main scanning of the sixth pass, the recording head 2 is moved from the third scanning base point P3 to the second scanning base point P2, and the four dot areas (8, 3), (7, 6), (6, 5), A dot is recorded at (5, 4).

Thereafter, the printing of the seventh and subsequent passes is performed in the same procedure. In the seventh pass (FIG. 27),
Dot areas (5,7), (6,4), (7,5),
The dots are recorded at (8, 6), and in the eighth pass (FIG. 28), dots are recorded in a total of 12 dot areas indicated by hatching in the figure. Further, in the ninth pass, FIG.
8, each dot indicated by a dotted line is recorded.

Next, a third example will be described with reference to FIGS. In the third example, in the first half (dot areas 1 to 5) in the sub-scanning direction, the first individual area is a 2-pass area, and the second individual area is a 4-pass area. Then, in the latter half of the sub-scanning direction (dot areas 6 to 10), the first individual area is switched to a 4-pass area, and the second individual area is switched to a 2-pass area. Then, these individual areas are solidly recorded by bidirectional scanning. Also in the third example, the nozzle openings 24 forming the nozzle row are #
It consists of one nozzle opening 24 to # 4 nozzle opening 24, and has eight dot regions in the main scanning direction and ten dot regions in the sub-scanning direction. In the third example, the control unit 11
(Printing operation control means) changes the number of passes at the boundary between the individual areas adjacent in the sub-scanning direction to a number between the number of passes set for each individual area. In the third example, the printing operation up to the fifth pass is the same as in the above-described second example (FIGS. 20 to 25), and a description thereof will not be repeated.

When the main scanning of the fifth pass is completed, FIG.
As shown in FIG. 9, the recording paper 12 is moved by one dot and
Prepare for the main scan in the pass. When the preparation is completed, the main scanning of the sixth pass is performed. In the main scan of the sixth pass, the recording head 2 is moved from the third scanning base point P3 to the first scanning base point P1, and the seven dot areas (8, 3),
(6,5), (5,4), (5,6), (4,5),
Dots are recorded at (2, 5) and (1, 6).

When the main scanning of the sixth pass is completed, FIG.
As shown in FIG. 0, preparations are made for the seventh pass main scanning, and when the preparation is completed, the seventh pass main scanning is performed. In the main scan of the seventh pass, the recording head 2 is moved from the first scanning base point P1 to the third scanning base point P3, and the eight dot areas (2, 6), (2, 7), (5, 7), (6,4),
Dots are recorded at (6, 6), (7, 5), (7, 7), and (8, 6).

When the main scanning of the seventh pass is completed, FIG.
As shown in FIG. 1, preparations are made for the main scanning of the eighth pass, and when the preparation is completed, the main scanning of the eighth pass is performed. In the main scanning of the eighth pass, the recording head 2 is moved from the third scanning base point P3 to the first scanning base point P1, and the eight dot areas (8, 5), (8, 7), (7, 6), (7,8),
(6,7), (5,8), (4,8), (3,6),
A dot is recorded at (3, 7). Here, the boundary area between the 4th pass and the 2nd pass in the second individual area, that is, the dot areas (5, 6) to (8, 6) hatched in FIG.
Is recorded in three passes, which is the number of passes between four passes and two passes.

When the main scanning of the eighth pass is completed, FIG.
As shown in FIG. 2, preparations are made for the ninth pass of the main scanning, and when the preparation is completed, the ninth pass of the main scanning is performed. In the main scanning of the ninth pass, the first scanning base point P1 is moved to the second scanning base point P1.
2, the recording head 2 is moved, and dots are recorded in the four dot areas (1, 8), (2, 9), (4, 6), and (4, 7).

When the ninth pass of the main scan is completed, FIG.
As shown in 3, prepare for the main scan of the 10th pass,
When the preparation is completed, the main scanning of the tenth pass is performed. This one
In the main scan of the 0th pass, the recording head 2 is moved from the second scanning base point P2 to the first scanning base point P1, and the four dot areas (4, 10), (3, 9), (2, 8), ( 1,7)
Record the dot at Then, in the printing operation after the eleventh pass, since the first individual area is printed in four passes, every third dot-printing area is selected in the main scanning direction. In addition, since the second individual area is printed in two passes, every other area for printing dots is selected in the main scanning direction.

Next, a fourth example will be described with reference to FIGS. In the fourth example, the first individual area is a two-pass area, and the second individual area is a four-pass area. The first individual area is recorded by unidirectional scanning, and the second individual area is recorded by bidirectional scanning. Also in the fourth example, the nozzle openings 24 forming the nozzle row are the nozzle openings 24 of # 1.
And # 4 nozzle openings 24. The dot area is eight in the main scanning direction and ten in the sub-scanning direction. Further, in the third example, the control unit 11 (printing operation control unit) determines whether an ink droplet is to be ejected when a recording region where ink droplets can be ejected and an idle region where ink droplets are not ejected are mixed in one pass of main scanning. The scanning speed of the recording head 2 in the idle region where the ink is not ejected is made higher than the scanning speed of the recording head 2 in the recording region.

Before starting the recording operation, first, FIG.
As shown in (2), the recording head 2 and the recording paper 12 are positioned at the scanning start position. In this scanning start state, the recording paper 12
No. 1 in the paper feed direction and the nozzle opening 24 of # 1
And the print head 2 is positioned at the first scanning base point P1. After positioning at the scanning start position, the first pass main scanning is performed. In the main scan of the first pass, the first
For the individual area, one dot line in the main scanning direction is printed in two passes, so dots are printed in two dot areas, that is, dot areas (1, 1) and (3, 1). Also,
As for the second individual area, one dot line in the main scanning direction is printed in four passes, so every third dot is selected in the main scanning direction (note that the second individual area in this example has four dots in the main scanning direction). Since it is composed of dot areas, one dot area (1, 5) is selected) and dots are recorded.

When the main scanning of the first pass is completed, FIG.
As shown in FIG. 5, preparation for performing the second pass main scanning by feeding the paper for one dot is performed, and when the preparation is completed, the second pass main scanning is performed. In the main scanning of the second pass, the recording head 2 moves from the third scanning base point P3 to the second scanning base point P2. As a result, main scanning is performed on the second individual area, and dots are recorded in the dot areas (7, 2) and (6, 1).

When the main scanning of the second pass is completed, preparations are made for the main scanning of the third pass. Here, the paper is fed by one dot, and the recording head 2 is moved (idle-fed) to the home position HP to be positioned at the first scanning base point P1. At this time, the control unit 11 (printing operation control unit)
The print head 2 in the idle running area (the area from the second scanning base point P2 to the first scanning base point P1) where the ink droplet is not ejected
Is made higher than the scanning speed in the recording area (the area from the third scanning base point P3 to the second scanning base point P2). As a result, the time until the preparation for the third pass is completed can be reduced. The effect of shortening the time is remarkable when recording is performed on the large-size recording paper 12 such as A0.

When the preparation is completed, the main scanning of the third pass is performed as shown in FIG. In the third pass of the main scan, the first individual areas are selected in a staggered manner so as to fill the dot areas not recorded in the first pass of the main scan. ), (2,3),
Dots are recorded at (3, 2), (4, 1), and (4, 3). In the second individual area, dots are recorded in three dot areas (5, 3), (7, 1), and (8, 2).

When the main scanning of the third pass is completed, FIG.
As shown in FIG. 7, the preparation for performing the second pass main scanning by feeding the paper for one dot is performed, and when the preparation is completed, the fourth pass main scanning is performed. In the main scan of the fourth pass, the recording head 2 is moved from the third scanning base point P3 to the second scanning base point P2, and the four dot areas (8,
1) Dots are recorded in (7, 4), (6, 3), and (5, 2).

When the main scanning in the fourth pass is completed, preparations are made for the main scanning in the fifth pass. Here, the paper is fed by one dot, and the recording head 2 is moved to the home position HP side to be positioned at the first scanning base point P1. Also in this case, the control unit 11 (printing operation control unit) sets the scanning speed of the recording head 2 on the first individual area where ink droplets are not ejected to be higher than the scanning speed on the second individual area.

When the preparation is completed, the main scanning of the fifth pass is performed as shown in FIG. The main scanning in the fifth pass is performed in the same manner as the main scanning in the third pass. For the first individual area, each of the dot areas (1,
3), (1,5), (2,2), (2,4), (3,
3) Dots are recorded in (3, 5), (4, 2), and (4, 4). In the second individual area, dots are recorded in four dot areas (5, 5), (6, 2), (7, 3), and (8, 4). Thereafter, the sixth pass main scanning is performed in the same manner as in the fourth pass (FIG. 39), and the seventh pass main scanning is performed in the same manner as in the third pass (FIG. 40).

In the above embodiment, the raster data obtained by expanding the print data is divided for each window WD, a rank is assigned to each window WD, and the distribution is performed according to the distribution state of the assigned rank. Although the individual regions R are set by grouping the windows WD, the present invention is not limited to this. For example, after dividing the entire area into a grid so as to surround the image data and setting a plurality of windows WD, the window WD of the image data is included and necessary windows WD are grouped to set an image individual area. Alternatively, the remaining windows may be set as individual text regions, and the number of passes of the individual image regions may be set to be greater than the number of passes of the individual text regions.

Hereinafter, another embodiment configured as described above will be described. In this embodiment, the control unit 11
Functions as individual area setting means, and as shown in FIG. 41, based on print data transmitted from a host computer by word processor software or the like, image data areas GD1 and GD2 and a text area TD constituting the entire area. And recognize.

After recognizing the image data areas GD1 and GD2 and the text area TD, the control unit 11 (window setting means) divides the entire area into a grid so as to surround the image data GD1 and GD2, and Window WD
Set. That is, as shown in FIG. 42, the band is divided at both ends in the sub-scanning direction in the image data, and the entire area is divided into four bands A to D. Here, for bands B and D containing only text data, the entire band is set in one window. For bands including image data (bands A and C), a window WD including only image data and a window WD including only text data are separately set.

After setting the window, the control unit 11
(Rank assigning means) assigns a rank to each window WD. As shown in FIG. 43, in the present embodiment, a rank “1” is assigned to the text data window, a rank “4” is assigned to the band A image data window, and a rank “4” is assigned to the band C image data window. "2"
Is given. In this embodiment, a value indicating the number of passes is used for the rank.

When ranks are given to each window,
As shown in FIG. 44, the control unit 11 (grouping unit)
Sets the image individual region GR by grouping the necessary windows WD including the window WD of the image data, and sets the remaining windows as the text individual region TR.

Here, since the window of the image data of band A is located at the end in the main scanning direction, although it is a single window, it is regarded as a group and one image individual area G
Set R1. Then, the rank of the individual image area is set to “4” which is the rank of the window WD. The window WD of the image data of the band C is
Since both sides in the main scanning direction are sandwiched between the windows WD of the text data, the three windows constituting the band C are grouped to set a single image individual region GR2. Further, the rank of the individual image area is set to the rank “2” which is the rank of the image data. For windows other than the image individual area, the text individual area TR is set by grouping in the main scanning direction, and the rank “1” which is the rank of the text data is set.

As described above, if a rank is assigned to each individual area GR, TR, the control unit 11 (pass number setting means) recognizes the rank assigned to each individual area GR, TR as the number of passes. And set. Then, each individual area GR, T
When the number of passes is added to R, the control unit 11 functions as a printing operation control unit, controls main scanning and sub-scanning based on the determined number of passes, and records an image on the recording paper 12. .

The present invention is not limited to the above configuration, and various modifications can be made based on the description in the claims. For example, in the above embodiment, the rank assigned to the window WD or the individual region R is a numerical value indicating the number of passes, but the present invention is not limited to this as long as it can be associated with the number of passes. For example, the rank corresponding to the one-pass area is “C”, the rank corresponding to the two-pass area is “B”,
The rank corresponding to the pass area may be “A”.

Although the piezoelectric vibrator 21 in the bending vibration mode has been described as an example of the recording head 2, a recording head using a piezoelectric vibrator in the longitudinal vibration mode may be used. Further, the recording head may include a heating element, expand and contract bubbles by heat from the heating element, and obtain a necessary pressure by the bubbles.

[0097]

As described above, according to the present invention, the following effects can be obtained. That is, a plurality of individual areas are set in the entire area based on the print data, the number of main scanning passes is determined for each set individual area, and printing is performed with the determined number of passes. In the area where the variation is conspicuous, printing is performed by increasing the number of passes, so that printing can be performed without deteriorating the image quality. Therefore, recording can be performed in that short time. As a result, the recording speed can be improved without sacrificing image quality.

The setting of the individual area is based on the step of dividing the raster data obtained by expanding the print data into each window set by dividing the whole area into a rectangular shape, and based on the raster data. When a step of assigning a rank for the number of passes for each window and a step of grouping each window according to the distribution state of the assigned rank and setting an individual area are sequentially performed, Since raster data can be processed in window units,
Processing is easy. Therefore, the setting of the individual area can be performed by a simple algorithm.

The setting of the individual area is performed by dividing the whole area into a grid so as to surround the image data and setting a plurality of windows, and grouping necessary windows by including the image data windows. If the image individual area is set and the steps of setting the remaining windows as the text individual area are sequentially performed, the number of passes can be set separately for the image individual area and the text individual area. By increasing the number of passes, printing can be performed on the image individual region where the variation between nozzle openings is conspicuous, and printing can be performed without deteriorating the image quality. Recording can be performed in a short time in minutes. As a result, the recording speed can be improved without sacrificing image quality.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an internal configuration of an ink jet printer.

FIG. 2 is a cross-sectional view illustrating a structure of a recording head.

FIG. 3 is a block diagram illustrating an electrical configuration of the printer.

FIG. 4 is a diagram illustrating an electric circuit system of the recording head.

5A is a schematic diagram illustrating a window set in the entire area, and FIG. 5B is a schematic diagram illustrating blocks forming the window.

FIG. 6 is a schematic diagram showing a relationship between windows and ranks, and a relationship between windows and bands.

FIG. 7 is a diagram illustrating a set individual area.

FIG. 8 is a diagram illustrating a state in which a recording head and a recording sheet are positioned at a scanning start position in a first example of a recording operation.

FIG. 9 is a diagram illustrating a first-pass main scan in the first example.

FIG. 10 is a diagram illustrating a preparatory operation for main scanning in the second pass in the first example.

FIG. 11 is a diagram for explaining main scanning in the second pass in the first example.

FIG. 12 is a diagram illustrating a preparatory operation for the third pass of main scanning in the first example.

FIG. 13 is a diagram illustrating main scanning in the third pass in the first example.

FIG. 14 is a diagram illustrating a preparatory operation for main scanning in the fourth pass in the first example.

FIG. 15 is a diagram illustrating a fourth-pass main scan in the first example.

FIG. 16 is a diagram illustrating a preparatory operation for the fifth pass of main scanning in the first example.

FIG. 17 is a diagram illustrating a main scan in a fifth pass in the first example.

FIG. 18 is a diagram illustrating a preparatory operation for the sixth pass of main scanning in the first example.

FIG. 19 is a view for explaining main scanning in the sixth pass in the first example.

FIG. 20 is a diagram illustrating a state in which a recording head and a recording sheet are positioned at a scanning start position in the second example.

FIG. 21 is a diagram illustrating a first-pass main scan in the second example.

FIG. 22 is a diagram for explaining main scanning in the second pass in the second example.

FIG. 23 is a diagram for explaining main scanning in the third pass in the second example.

FIG. 24 is a diagram for explaining main scanning in the fourth pass in the second example.

FIG. 25 is a diagram illustrating a fifth-pass main scan in the second example.

FIG. 26 is a view for explaining the main scanning in the sixth pass in the second example.

FIG. 27 is a diagram illustrating a seventh-pass main scan in the second example.

FIG. 28 is a diagram illustrating an eighth pass main scanning in the second example.

FIG. 29 is a diagram illustrating a sixth pass main scanning in the third example.

FIG. 30 is a diagram for explaining main scanning in the seventh pass in the third example.

FIG. 31 is a diagram illustrating an eighth pass main scanning in the third example.

FIG. 32 is a diagram illustrating a ninth pass main scanning in the third example.

FIG. 33 is a diagram illustrating main scanning in the tenth pass in the third example.

FIG. 34 is a diagram for describing main scanning in the first pass in a fourth example.

FIG. 35 is a diagram for explaining main scanning in the second pass in the fourth example.

FIG. 36 is a view for explaining main scanning in the third pass in the fourth example.

FIG. 37 is a view for explaining main scanning in the fourth pass in the fourth example.

FIG. 38 is a view for explaining main scanning in the fifth pass in the fourth example.

FIG. 39 is a view for explaining the main scanning in the sixth pass in the fourth example.

FIG. 40 is a view for explaining the main scanning in the seventh pass in the fourth example.

FIG. 41 is a schematic diagram illustrating an image data area and a text area in another embodiment.

FIG. 42 is a schematic diagram illustrating a state after window division according to another embodiment.

FIG. 43 is a schematic diagram illustrating a relationship between a window and a rank according to another embodiment.

FIG. 44 is a schematic diagram illustrating a state after individual region division according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink-jet printer 2 Recording head 3 Ink cartridge 4 Carriage 5 Housing 6 Guide member 7 Pulse motor 8 Drive pulley 9 Idling pulley 10 Timing belt 11 Control part 12 Recording paper 13 Paper feed motor 14 Paper feed roller 21 Piezoelectric vibrator 22 Pressure chamber 23 Actuator unit 24 Nozzle opening 25 Flow path unit 31 Printer controller 32 Print engine 33 Interface 34 RAM 35 ROM 36 Oscillation circuit 37 Drive signal generation circuit 38 Interface 41 Electric circuit system of recording head 42 Shift register 43 Latch circuit 44 Level shifter 45 Switch circuit

Claims (12)

[Claims] 1. A main scan for ejecting ink droplets while moving a recording head having a nozzle row composed of a plurality of nozzle openings in a direction intersecting the nozzle row direction, and a recording medium in a direction orthogonal to the main scanning direction. By repeatedly performing the sub-scan to move the print data, a single dot line is printed by a plurality of main scans with different nozzle openings, and an ink jet printing method for printing an image based on print data on a print medium. A plurality of individual areas are set in the entire area based on the number of passes, and the number of main scanning passes is selected and determined from a preset number of different passes for each set individual area, and is recorded with the determined number of passes. And an inkjet recording method. 2. The method according to claim 1, wherein the setting of the individual area includes dividing the raster data obtained by expanding the print data into each window set by dividing the entire area into a rectangular shape. 2. The method according to claim 1, wherein a step of assigning a rank to each window based on the order, and a step of grouping the windows according to the assigned rank distribution state and setting an individual area are sequentially performed. The ink-jet recording method as described above. 3. The window is composed of a plurality of small blocks. The step of assigning the rank includes the steps of: detecting a recording density of each block constituting the window based on raster data; 3. The method according to claim 2, wherein a step of setting a block level corresponding to the recording density for each block based on the density and a step of assigning a rank of the window based on a distribution state of the block level are sequentially performed. 3. The ink jet recording method according to item 1. 4. The setting of the individual area includes a step of setting a plurality of windows by dividing the entire area into a grid so as to surround the image data, and a step of grouping necessary windows by including a window of the image data. 2. The ink jet recording method according to claim 1, further comprising the steps of: setting an individual image area by setting the remaining windows as text individual areas; 5. A printhead having a nozzle row composed of a plurality of nozzle openings, a main scan for ejecting ink droplets while moving the printhead in a direction intersecting the nozzle row direction, and a main scan direction. A printing operation control means for controlling sub-scanning for moving the recording medium in a direction orthogonal to the main scanning; and performing main scanning and sub-scanning repeatedly to perform one-dot main scanning in a plurality of passes using different nozzle openings. And an individual area setting means for setting a plurality of individual areas in the entire area based on the print data; and an individual area setting means for recording an image based on the print data on a recording medium. A pass number setting means for selecting the number of main scanning passes for each individual area set by the setting means from different preset pass numbers; Control means, an ink jet recording apparatus characterized by, based on the number of paths in the main scanning which defines the path number setting means, controls the main scanning and sub scanning. 6. The raster data dividing means, wherein the individual area setting means divides raster data obtained by expanding print data into each window set by dividing an entire area into a rectangular shape; It is characterized by comprising rank assigning means for assigning a rank to each window based on raster data, and grouping means for grouping each window according to the assigned rank distribution state and setting an individual area. The ink jet recording apparatus according to claim 5, wherein 7. The window is composed of a plurality of small blocks, and the rank assigning unit detects a recording density of each block constituting the window based on raster data, and detects each block based on the detected recording density. 7. A method according to claim 6, wherein a block level is set according to the recording density, and a rank is assigned based on the distribution state of the block level.
3. The ink jet recording apparatus according to claim 1. 8. The ink jet recording apparatus according to claim 6, wherein the rank assigned by the rank assigning unit is a numerical value indicating the number of passes in the main scanning. 9. The individual area setting means sets an image individual area including image data and a text individual area consisting of only text data based on print data, and the pass number setting means sets a path of the image individual area. 6. The ink jet recording apparatus according to claim 5, wherein the number of passes of each individual area is set so that the number is larger than the number of passes of the individual text area. 10. The individual area setting means includes window setting means for setting a plurality of windows by dividing an entire area into a lattice so as to surround image data, and including a window for image data. 10. The ink jet recording apparatus according to claim 9, wherein windows are grouped to set an image individual area, and the remaining windows are set as text individual areas. 11. The printing operation control means, when a different number of passes is set for individual areas adjacent in the sub-scanning direction, sets the number of passes at a boundary portion to the number of passes set for each individual area. The ink jet recording apparatus according to any one of claims 5 to 10, wherein the number is changed to a number between the numbers. 12. The printing operation control unit according to claim 1, wherein the print head scans in the idle running area when the printing area in which the ink droplets can be ejected and the idle running area in which the ink drops are not ejected are mixed in one pass main scanning. 12. The ink jet recording apparatus according to claim 5, wherein the speed is higher than the scanning speed of the recording head in the recording area.