JP3170898B2 - Recording device and recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording method for forming an image or a character on a recording material (paper or the like) using a pixel matrix of recording dots of an ink jet printer or the like, or a single dot.
The present invention relates to an apparatus and a recording method.

[0002]

2. Description of the Related Art Color recording by the ink jet system can be easily achieved structurally by providing inks of respective colors, and has been put to practical use as a mainstream technology of a low-cost color printer. A recording material (paper or the like) of a recording apparatus that performs recording based on image or character data as shown in FIG. 1 and a recording element group (nozzles in the head) are attached at substantially right angles, and the head is moved in the main scanning. In a serial printer that forms an image by moving a recording material by moving and sub-scanning, in order to express a color image at high speed and with high quality, it is necessary to increase the density of the nozzle of the printer head and increase the head in the sub-scanning direction. It is necessary to increase the number of nozzles by increasing the number of nozzles. However, increasing the density of the head requires higher precision of the mechanism mechanism including the head, which increases the manufacturing cost.

Therefore, an interlace driving method has been disclosed as a countermeasure for this. This is a configuration in which a plurality of identical comb-tooth-shaped heads are arranged in the main scanning direction and are shifted in the sub-scanning direction. By performing the sub-scanning, one dot line is left unrecorded. It is possible to record portions sequentially and fill them. Each head has a different color such as Y, M, and C. An example of the interlace driving method is Japanese Patent Publication No. 3-76226. This is because a plurality of unit recording element groups in which N recording elements are arranged at K dot intervals are set to H which is an integral multiple of N in the main scanning direction.
It is arranged on the stairs with the dot interval shifted, and N
This is a method of performing sub-scan feed by dot and recording. This prevents overlapping of other color inks before the color ink ejected on the recording paper is not sufficiently dried, and keeps the order of the recording colors constant. After that, N
This interlace driving method for performing the sub-scan feed for the dots is referred to as an equal-interval sub-scan feed interlace drive.

FIG. 9 shows a driving situation in the case where the number of nozzles N is relatively large, N = 15, for the equal-interval sub-scan feed interlace driving. The square frame on the left side shows the arrangement of print heads having print elements for four colors. Nozzle number N =
15. Nozzle spacing K = 4 dots, M1, M2, M3,
M4 is a unit recording element group of each color, which is arranged at intervals of H = 15. T indicates the number of sub-scans, and T1,
One cycle ends at T2, T3, and T4. When the main scanning in T1 is completed, the unit recording element group is fed in the sub-scanning direction by P = 15 dots, and the main scanning in T2 is performed. Points indicated by black circles indicate recording dots,
For the M1 color, six main scans are performed. For the M2 and M3 colors, only T1 is shown. For the M4 color, T1 to T4 are shown. From this figure, it can be seen that by performing scanning with T1, T2 #, dots corresponding to the recording nozzles are recorded, and the vacant portions are gradually filled. At this time,
As shown in FIG. 11, the printing order of colors is performed in a fixed order on all printing lines.

Further, separately from the above, interlaced driving is performed in which a one-dot line feed interpolation is performed in the sub-scanning direction for each main scan, and a plurality of dots are fed to the next recording section in the sub-scanning direction when the head width is filled. There is a law. For example, N =
When 15, K = 4, the sub-scan feed is performed three times by one dot line feed during four consecutive main scans, and the fourth feed is performed by the sub-scan direction feed of 47 dot lines. This interlace driving method is referred to as one-dot line sub-scan feed interlace driving.

[0006]

SUMMARY OF THE INVENTION In order to speed up the recording time, it is necessary to increase the number of recording elements.
The width of the head in the sub-scanning direction increases. Specifically, a comparison between the head length and the memory capacity in the above two conventional examples will be described. In the case of N = 15, K = 4, M = 4 row nozzles and H = 15 in FIG. 9 described above, X = 0.0706 mm per dot
The distance A (hereinafter referred to as head length) between both ends of all nozzles in the sub-scanning direction at (360 dots / inch) is A = [H × (M−1) + (N−1) × K] × X mm .. (1) and A = 7.1 mm = 101 dot length.

On the other hand, in the one-dot line sub-scan feed interlaced drive, the same condition is applied to four rows of nozzles for one dot.
In the case of a dot-shifted head, the head length A in the sub-scanning direction is as follows: A = [(N−1) × K + (M−1)] × X = [NK−1] × X mm 2) and A = 4.2 mm = 59 dot length. The amount of buffer memory for temporarily storing data at the time of recording also has a capacity proportional to the length, which is about 1.7 times as large. When the number of nozzles is increased as described above, the head length is increased in the conventional interlaced drive in which the color order is fixed, so that the buffer memory capacity is increased, the demand for the mechanism is also increased, and the price is increased. . On the other hand, if the conventional one-dot line sub-scan feed interlace drive with a short head length is used, the color order must be extended several times. Can not meet.

In addition, since the position of the nozzle end of the head in the sub-scanning direction is close to each other for each color, the misalignment is easily seen.
Further, since the difference in the amount of one sub-scan feed is large, uneven feed in the sub-scan direction caused by a mechanical manufacturing accuracy error becomes easy to see, which causes quality deterioration.

The recording apparatus and recording method of the present invention solve such a problem. The purpose of the recording apparatus and recording method is to reduce the head length in the recording sub-scanning direction as much as possible by using an interlaced recording method. In a recording method in which time is shortened as much as possible, it is possible to provide a recording apparatus and a recording method capable of performing high-resolution and high-speed recording without changing the color order of color recording by suppressing variation in mechanical accuracy. Ah
You.

[0010]

According to the present invention, there is provided a recording apparatus for performing recording on a recording medium while performing main scanning and sub-scanning based on recording data. The N unit recording element groups are different from each other.
A printing element group in which the unit printing element groups having different printing colors are arranged in a plurality of rows at predetermined intervals in the main scanning direction and H dots in the sub-scanning direction, and an image data storage unit for storing printing data as image data An image data processing means for selecting image data from the image data storage unit in accordance with the arrangement of the unit recording element group and transferring the image data to the recording element group; and a main unit for performing recording in a main scanning direction on a recording medium. A scanning driving unit, a sub-scanning driving unit for performing recording in a sub-scanning direction on a recording medium, and a driving unit control unit for controlling the main scanning driving unit and the sub-scanning driving unit; The control means performs (K + α-1) sub-scan feeds for the P dot interval for each main scan of the recording element group, and then repeats one sub-scan feed for the S dot interval. It performed, wherein K, N, S, P, alpha is the recording apparatus characterized by satisfying the following
Furthermore, based on the recording data, while performing main scanning and sub scanning, a recording method for recording on a recording medium, a step of storing the recorded data as image data, respectively, from the image data storage unit Different recording colors
A step of unit image data to match the arrangement of the recording element group select to transfer to the recording element group that, a main scan driver for performing recording in the main scanning direction on a recording medium, sub-scanning on the recording medium And a sub-scanning drive unit for performing recording in the direction, and performing (K + α−1) sub-scan feeds for a P dot interval for each main scan of the recording element group,
Performing a sub-scan feed that repeats a single sub-scan feed for a dot interval; and performing the K, N, S, P,
α is a recording method characterized by satisfying the following conditions. α is an integer value, 1 ≦ α ≦ K H is a positive integer, H <NP is a positive integer other than 1, and P <N × K / (K + α) K / N, K / H and K / P is an irreducible fraction S = K × N− (K + α−1) × P

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIG. 1 shows a color serial printer according to the present invention. 101 is a color head including a recording element, 102 is a recording paper as a non-recording material, and 103 is a platen. The head 101 performs a main scanning recording operation on the area A in the direction of the arrow. The main scanning operation is performed at a constant speed to record at a predetermined position using a pulse motor, a DC motor, or the like as a power source, and monochrome recording or color recording is performed.
After the main scanning, the recording paper 102 moves in the sub-scanning direction by the rotation of the platen 103 or the rotation of a paper feed roller (not shown), and the recording main scanning is performed again to perform recording.

FIG. 2 shows an example of the configuration of a color head comprising a plurality of unit recording element groups, which are main components of the present invention. 201 is a unit recording element group of the first color, 202 is a unit recording element group of the second color, 203
Is a unit recording element group for the third color, 204 is a unit recording element group for the fourth color, 205 is a nozzle unit that ejects ink of the recording element group, 206 is a holding unit that supports the recording element group, 207 is a tube that supplies ink, Reference numeral 208 denotes a cable for supplying an electric signal. A plurality of nozzles 205 are arranged at regular intervals, and the unit recording element group is arranged in a plurality of rows to constitute a head as a whole. These heads are attached to the main scanning axis by a head holding unit 206.
And color printing is performed by operation in the main scanning direction. That is, in the printing at the time of the main scanning, a signal accompanying data corresponding to the printing position is supplied to the ink ejection element groups 201 to 204 via the cable 207, ink is ejected from the nozzles 201, and printing of each color is performed on printing paper or the like.
The ink can be supplied by disposing an ink tank outside the head as shown in FIG. 2, but it is also possible to dispose the ink on a movable portion in the head. FIG. 3 is a block diagram showing components of the present invention. The processing-related constituent means of 301 is a buffer memory 30
3. It comprises processing means 304 and control means 305.
Reference numeral 302 denotes a mechanism-related component, in which a recording element group 306 is arranged. In this apparatus which has received a recording instruction from a personal computer, a workstation, or the like, processing for printer recording such as expansion of character data and expansion of graphics is performed, and the recording data is temporarily recorded in the buffer memory 303. The buffer memory is a memory in which the recording data is partially arranged, and a call in accordance with the recording order is performed from this memory based on an instruction of the processing unit 304. Data to be printed in one head main scan is called from the buffer memory 303 and transferred to a latch circuit (temporary holding circuit (not shown)) for the print element group 306. The control unit 305 is a unit that controls all operations such as the operation of the print head, the print operation instruction to the print element group, the movement of the print paper, and the like. This control means controls interlaced scanning for printing, which will be described later.

FIG. 4 shows an example of the arrangement of a unit recording element group according to the present invention. The unit recording element group is a component in the head shown in FIG. 2, and discharges ink from the nozzles to record dots on recording paper. 4-A
Is an example in which four colors are composed of one row of recording element groups in four-color printing. 4-B is an example in which one color is composed of two columns in color printing of a four-color configuration. In each of the examples A and B, the number of nozzles per row N =
15 and a configuration example of the nozzle interval K = 4. At this time, the values of K and N are selected so that K / N is an irreducible fraction.

4-A denotes a nozzle pitch in the sub-scanning direction within one line of each color K = 4 dots, N = 15 nozzles, and M1, M2,
Each of M3 and M4 records a dot of a different color ink. Each color of M1, M2, M3, and M4 is, for example, magenta, cyan, yellow, and black. The shift in the sub-scanning direction of each column is H = 7 dots.

In 4-B, only one color has a two-row configuration, and the other three colors have a one-row configuration. It is applied to increase the printing speed of monochromatic printing or increase the number of printing nozzles.

Using this head, interlaced scanning for recording, which will be described later, is performed.

In the arrangement of the recording element group in FIG. 1, the condition is that the element groups A and B shown in FIG. 4 are arranged at positions substantially perpendicular to the non-recording material (recording paper) when attached to the printer. Is what you do.

FIG. 5 shows an embodiment of the present invention. This shows an interlaced recording system by the means described above.
M1, M2, M3, and M4 in the four columns on the left side show the arrangement of nozzles of four colors, and the four blocks on the right side show the dot positions in the sub-scanning direction at the time of recording by representative points.

As a description procedure, first, the recording order of single color printing of only M1 will be described, and then the case of color printing will be described.

First, the operation of the unit M1 which is a unit recording element group arranged on the leftmost side of the figure will be described. This unit recording element group has the number of nozzles N = 15 described in 4-A of FIG.
The nozzle pitch K = 4. As in the description of FIG. 9, the number of times of main scanning is represented by T, and the number of times of one stroke is (K
+ Α) times, since α = 2 for this M1 color, one cycle is performed by a total of six main scans. Subsequent to the first main scanning at T1, the P dot line is skipped in the sub-scanning direction, and the second main scanning is performed. As for the value of the sub-scan feed amount P, K / P is an irreducible fraction (P <N × K / (K +
α), P ≠ 1 is a positive integer), and a value of P = 7 is selected here. By this feeding of P, the second printing section is printed on a line that does not overlap with the dot line printed in the first printing, and T3, T4, T5, and T6 are also printed by P-dot feeding and scanning. After these six scans, the sub-scan feed to the next dot line is performed, and one stroke is completed. The sub-scan feed amount S at this time is determined by S = K × N− (K + α−1) × P (3) In this embodiment, S = 4 × 15− (4 + 2-1) × 7 = 25 dots.

Here, reference will be made to (K + α), which is the number of main scans in one cycle. In the case of a print scan group having a nozzle configuration with K intervals, one cycle is completed by K main scans. However, in the present invention, one stroke is increased by α times to guarantee the ink printing order in color printing. I have. The principle will be described later.

Next, recording of M1, M2, M3 and M4 will be described. K / H is an irreducible fraction (a positive integer satisfying H <N) as the value of the displacement H in the sub-scanning direction of each unit recording element group.
In this embodiment, the value of H = 7 is selected. Under these conditions, if the number of recording inks M and K is M ≦ K, simultaneous recording of inks can be avoided. Here, M = 4 and K = 4
Therefore, simultaneous recording of color ink does not occur.

The recording order of the color ink of the present invention is as follows.
This shows an example in which the order of recording colors is not changed and limited to three colors of M1, M2, and M3. As described above, printing is performed without changing the printing order of M1, M2, and M3 in the five main scans of M2 and the four main scans of M3 with respect to the six main scans of M1. As a result, the main scanning is performed six times in one process. In the case of unnecessary recording colors (the sixth main scanning in M2, and the fifth and sixth main scanning in M3), the operation is performed but the recording is not performed. In addition, in dot printing of each color in one process, allocation is performed for each nozzle as to whether or not to perform printing with each nozzle in the printing order, and printing is not performed at an extra printing timing.

The specific recording order will be described with reference to FIGS. 5, 6, and 7. FIG. 6 shows a printing nozzle in the case of performing one-stroke four main scans of the M1 color in FIG. 5 (a driving method of ending one stroke at T4 excluding the square frame portion of the M1 recording order portion in FIG. 5). No. (n) and the number of times of recording (T) are checked in the order of recording. For example, from the upper left of the table, the dot line printed at the T = 04th main scanning timing with the n = 1st nozzle of the M1 unit printing element group, and the T = 03rd main scanning timing with the n = 3rd nozzle next Indicates a dot line recorded by. Here, the second digit of T = 01 of the number of recordings describes the next process after four main scans in the order of the main scan. According to this table, recording within one color has zero strokes.
It can be seen that the number of steps increases as the steps are mixed with the first step. Next, when the colors are multicolored, the recording order of this table is shifted for each color by the shift value H of the nozzle position in the sub-scanning direction. For example, a shift for each color of N = 15 (however, in the conventional example, P = 15 in each sub-scan feed in the same-interval sub-scan feed interlace driving, in this example, P = 7) is used. Considering this, the first line of the next color is recorded at a position shifted by 15 lines, which corresponds to a case where each column of the table in FIG. 6 is shifted. In this case, when the table is viewed in the horizontal direction, the recording order for each color is compared, and if the order is fixed, such as from the left column to the right column, the recording order will not change. In FIG. 6, when viewed in four color columns, for example, 03, 04, 0 in the first horizontal row
Since the order of the first, twelfth and third columns is reversed, it is not possible to record the colors in a fixed order. Here, the color order in the conventional equal-interval sub-scanning interlace method will be viewed from the same viewpoint. FIG. 10 is a table similar to FIG. The number of rows is adjusted to the number of nozzles N = 15 and the feed interval P = 15, and there are 15 rows. When each row is compared, the order of recording is constant from left to right for all rows. The conventional method can easily stabilize the color order, but has the disadvantages of the head length and mechanical accuracy as described in the subject, and the color order is adjusted by shortening the overall length of each color in the sub-scanning direction. In the present embodiment, the color order in FIG. 6 is increased by increasing the number of main scans within one stroke, and the case where the recording order is different for each color is extracted and corrected to guarantee the color order.

FIG. 7 shows the case of this embodiment, in which the number of main scans per stroke is changed from four to six. As a result, printing has been successfully performed in a fixed color order for all lines. In this embodiment, three colors M1, M2, M
This is an example of a case where a color recording order of No. 3 is designated. The hatched line indicated by D in the figure cannot guarantee the recording order. Therefore, the number of feed nozzles N = 15, the nozzle interval K = 4, the sub-scan feed P = 7,
The three-color order designation with the displacement H in the sub-scanning direction is achieved by performing six scans in one stroke. The three colors are corrected at T5 and T6 so that the recording order is constant. M here
The driving operations of M1, M2, and M3 correspond to M1, M2, and M3 in FIG. 5. In six main scans, T1 and T5 have a common dot line, and T2 and T6 have the same common dot line. For the above-mentioned common dot line, recording is performed in black dot portions as indicated by T1, T5 in T1, T2, T5, T6, and M2 portions of M1 in FIG. Not performed. That is, the print output is selectively designated, and the main scan printing is performed. In this case, a recording time 1.5 times as long as the conventional example of FIG. 6 is required.
The head length A in the sub-scanning direction at this time is indicated by A in FIG. 5, and the general formula is: A = [P × (M−1) + (N−1) × K] × X
(4) The length X between one dot in this example X = 0.0706 mm
In the case of (360 dots / inch), A = 5.43 mm = 77 dot length, which is shorter than A = 7.1 mm = 101 dot length of the equally spaced sub-scan feed interlace driving method under the same conditions. The disadvantage of the interlace driving method is that the non-recording area C that cannot be recorded on all dot lines that occur at the beginning and end of recording
(C in FIG. 5) also becomes shorter as the head length A in the sub-scanning direction becomes shorter. C is a general formula: C = (K−1) × (P + H−1) (5), and C = 39 dot lines in the embodiment of FIG. 5 (in the conventional equal-interval sub-scan feed interlace driving, C = 87 under the same conditions).

In the above embodiment, the case of correcting the three-color printing order has been described. However, in order to specify the four-color printing order, a T7 main scanning line is provided and the correction in FIG. By doing so, the color recording order can be similarly specified.

In summary, the relational expressions of the apparatus of the present invention are as follows: K / N, K / P and K / H: irreducible fraction P dot sub-scan feed (K + α-1) times S dot sub-scan feed once P P <N × K / (K + α), and a positive integer S satisfying P ≠ 1 is S = N × K− (K + α−1) × P.

A supplementary explanation of the above relational expression will be given. P
Is the total number of feed strokes in the sub-scanning direction is N × K dot lines, and a value obtained by dividing the total number by (K + α) times is the maximum value of the sub-scanning amount sent in one step. . For the method of selecting P, P <N × K / (K + α),
Although a range of positive integer values of P ≠ 1 is defined, when approaching the maximum value, the values of P and S approach, which is useful for improving the mechanical feed accuracy. However, the invalid recording range of Expression (4) is large. Become. When P approaches 1, the opposite relationship is established. Therefore, P
Is to select an appropriate value based on various conditions of the printer components, such as the length in the head sub-scanning direction, the variation in mechanical accuracy, the capacity of the buffer memory for storing data, and the like. The value of S is to send the remaining amount obtained by subtracting the amount sent by the number of times of P feeding (K + α-1) from the total number in one stroke.

When the value of H is the minimum value H = 1, the head length A in the sub-scanning direction becomes the minimum, and the head length can be shortened with respect to the conventional equal-interval sub-scan feed interlace driving, and the effect can be found, but it is more invalid. The recording area C is also reduced, which is advantageous. However, since the positions of the nozzle ends in the sub-scanning direction are close to each other for each color, it is easy to see a shift that may occur due to a slight feeding accuracy error. Therefore, it is desired that the selection of the value of H be large to some extent.

FIG. 8 shows another embodiment. K = 4, N = 3
1, three colors of P = 15, H = 7, and one color of N = 31,
This is an example of a recording element group composed of two rows. As in the case of FIG. 5, one stroke is performed in six sub-scans, and a continuous printing operation is performed. Six main scans are performed to match the recording order of the three colors M2, M3, and M4, and one of T1 and T5 shown in the recording order portion of M2, and T2
And T6, that is, the recording is performed by selecting the black circle, and the recording order is guaranteed. When such recording elements increase, the head length A in the sub-scanning direction and the non-recording area C can be selected more effectively. For M1, two scans of other print elements are provided as a unit print element group, which is effective in improving the printing speed of a single color.

As for the problem that the printing speed is reduced as compared with the conventional equal-interval main-scan feed interlace driving method, the frequency of use in a request for a small number of recording colors, such as 7 colors and 16 colors, is required in a general color printer. Therefore, these requirements satisfy the purpose of color printing without guaranteeing the color order. Further, in the case of using a full-color image, a processing time for producing a full-color image requires time, so that a slight delay in the recording time does not pose a problem in a low-cost printer. Therefore, the switching of the driving method between high quality recording and high speed recording is effective in practical use.

[0033]

As described above, according to the present invention, K / N, K / K / K / N dots are displaced in the main scanning direction for each color in the recording element group of K dots and N nozzles in the sub-scanning direction.
H and K / P are irreducible fractions, P <N × K / (K + α), P ≠
When the feeding of the P dot in the sub-scanning direction having the condition of a positive integer P being 1 in the sub-scanning direction is performed (K + α-1) times, S = K × N− (K + α−
1) S dot sub-scan feed with the condition of × P dot
Since the interlaced driving method is performed repeatedly, the color recording order of the color recording can be made constant while the head length in the sub-scanning direction is kept short even when the printer is configured with a head having a large number of nozzles. In addition, the number of invalid recording areas is reduced as compared with the conventional interlaced drive of equal-interval sub-scan feed, so that unnecessary sub-scan feed is not required. further,
It is possible to improve a decrease in recording quality due to a mechanical variation caused by a difference in a sub-scan feed amount for each time as compared with a conventional one-dot sub-scan feed interlaced driving method, without increasing the price. Recording quality can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of one embodiment of the present invention.

FIG. 3 is a diagram of one embodiment of the present invention.

FIG. 4 is a diagram illustrating the configuration of one embodiment of the present invention.

FIG. 5 is a diagram of one embodiment of the present invention.

FIG. 6 is an explanatory diagram of one embodiment of the present invention.

FIG. 7 is an explanatory diagram of one embodiment of the present invention.

FIG. 8 is a diagram of another embodiment of the present invention.

FIG. 9 illustrates a conventional example.

FIG. 10 illustrates a conventional example.

FIG. 11 illustrates a conventional example.

[Explanation of symbols]

 201 unit recording element group 205 nozzle unit 303 buffer memory 304 processing unit 305 control unit 306 recording element group

Claims (5)

(57) [Claims] 1. A printing apparatus for performing printing on a printing medium while performing main scanning and sub-scanning based on print data, comprising: N unit printing elements arranged at intervals of K dots in a sub-scanning direction. Groups, and a plurality of printing element groups in which the unit printing element groups, each having a different printing color, are arranged at predetermined intervals in the main scanning direction and H dots in the sub-scanning direction, and the printing data is image data. An image data storage unit for storing, image data processing means for selecting image data from the image data storage unit in accordance with the arrangement of the unit recording element group, and transferring the selected image data to the recording element group; A main scanning drive unit for performing printing, a sub-scanning drive unit for performing printing in a sub-scanning direction on a recording medium, and a drive unit control for controlling the main scanning drive unit and the sub-scanning drive unit And means, wherein the drive unit control means, P for each main scan of the recording element group
After the sub-scan feed for the dot interval is performed (K + α-1) times, the sub-scan feed for the S dot interval is repeated once, and K, N, S, P, and α satisfy the following conditions. A recording device, characterized in that: α is an integer value, 1 ≦ α ≦ K H is a positive integer, H <NP is a positive integer other than 1, and P <N × K / (K + α) K / N, K / H and K / P is an irreducible fraction S = K × N− (K + α−1) × P 2. The recording apparatus according to claim 1, wherein said unit recording element group of a limited color is constituted by a plurality of rows. 3. The recording apparatus according to claim 2, wherein a multi-color recording or a single-color recording using only a limited number of unit recording element groups can be selected. 4. The printing apparatus according to claim 1, wherein α is set so that the ink printing order during color printing is constant. 5. A recording method for performing recording on a recording medium while performing main scanning and sub-scanning based on recording data, comprising: a step of storing recording data as image data; Each has a different recording color
A process of selecting image data corresponding to the arrangement of the unit recording element group and transferring the image data to the recording element group; a main scanning drive unit for performing recording in the main scanning direction on the recording medium; A sub-scanning drive unit for performing recording in the scanning direction; a step of controlling; and a sub-scan feed for a P-dot interval for each main scan of the recording element group performed (K + α-1) times, and then an S-dot. A process of repeating one sub-scan feed for an interval, and wherein K, N, S, P, and α satisfy the following conditions. α is an integer value, 1 ≦ α ≦ K H is a positive integer, H <NP is a positive integer other than 1, and P <N × K / (K + α) K / N, K / H and K / P is an irreducible fraction S = K × N− (K + α−1) × P