JP4777014B2 - Inkjet recording method - Google Patents

Description

  The present invention relates to an ink jet recording method and an ink jet recording apparatus. In particular, an image is printed on the recording medium while alternately performing main scanning for moving the recording head for ejecting ink relative to the recording medium and sub-scanning for transporting the recording medium in a direction crossing the main scanning. The present invention relates to a serial type inkjet recording method to be formed.

  An ink jet recording apparatus (ink jet recording apparatus) performs recording by ejecting ink from a recording means (recording head) onto a recording medium, and is easy to achieve higher definition and faster than other recording methods. It has excellent characteristics of being quiet and inexpensive. In order to improve the recording speed, the ink jet recording apparatus uses a recording head in which a plurality of recording elements are integrated and arranged and a plurality of ink discharge ports and liquid paths as ink discharge portions are integrated. In the case of color correspondence, a plurality of recording heads for ink colors to be recorded are provided.

  FIG. 1 is a diagram for explaining a main configuration of a general ink jet recording apparatus. In the figure, reference numeral 101 denotes an ink cartridge containing four color inks, black, cyan, magenta and yellow. Each ink cartridge 101 is connected to a recording head 102 that can eject ink of each color, and supplies the ink consumed by the ejection to the recording head 102. A carriage 106 is capable of reciprocating scanning in the X direction with the recording head 102 and the ink cartridge 101 mounted thereon.

  FIG. 2 is a diagram illustrating a plurality of ejection openings arranged in the recording head 102 from the Z direction. Reference numeral 201 denotes a nozzle for discharging black ink, which is disposed on the recording head 102. In the recording head 102 of this example, 40 nozzles are provided at intervals of 1/600 inch for black ink. In this case, when ink is ejected from each ejection port while moving the recording head in the X direction, dots are recorded on the recording medium at a resolution of 600 dpi (dot / inch; reference value) in the sub-scanning direction (Y direction). The

  Returning again to FIG. Reference numeral 103 denotes a paper feed roller, which rotates in the direction of the arrow in the figure while suppressing the recording medium P together with the spur 104, and feeds the recording medium P in the + Y direction sub-scanning direction as needed. A pair of paper feed rollers 105 feeds the recording medium P and plays the role of suppressing the recording medium P as in the case of 103 and 104.

  When the recording operation is not performed, or when the recovery operation of the recording head is performed, the carriage 106 stands by at the home position (h) indicated by the dotted line in the drawing. When a recording start command is input, the carriage 106 at the home position moves at a predetermined speed in the main scanning direction in the + X direction and performs recording by the plurality of nozzles 201 on the recording head 102. When the scanning to the end of the recording medium located on the side opposite to the home position is completed, the carriage 106 returns to the home position. During this time, the recording medium is conveyed by a predetermined amount in the Y direction. By repeating these steps, images are sequentially formed on the recording medium. When performing high-speed printing, it is also possible to perform recording from both the forward path direction of the carriage 106 in the + X direction and the backward path direction of the −X direction.

  In such an ink jet recording apparatus, it is known that slight variations in nozzle units that occur in the recording head manufacturing process cause density unevenness of a recorded image and cause deterioration in image quality. A specific example will be described with reference to FIGS.

  In FIG. 3A, reference numeral 31 denotes a recording head. Here, for the sake of simplicity, it is assumed that the recording head 31 includes eight nozzles 32. Reference numeral 33 denotes ink droplets ejected by the nozzle 32. Normally, as shown in this figure, it is ideal that the ink is ejected in a uniform direction with a uniform discharge amount. If such ejection is performed, dots of uniform size are landed on the recording medium as shown in FIG. 3B, and a uniform image with no density unevenness is obtained as a whole. (FIG. 3C).

  However, the size and direction of ink droplets actually ejected from individual nozzles include variations as shown in FIG. In this case, the recording medium is in a recording state as shown in FIG. 4B, and there may be a blank portion where the area factor cannot satisfy 100%, or a portion where dots overlap more than necessary.

  A collection of dots landed in such a state has the density distribution shown in FIG. 4C, and this distribution repeatedly appears in the conveyance direction of the recording medium. As a result, as long as it is visually observed, it is perceived as uneven density.

A multipass printing method has already been devised and implemented for such density unevenness that appears periodically in the sub-scanning direction (see, for example, Patent Document 1).
5A to 5C are schematic diagrams for explaining the multipass printing method. Multipass recording is a recording method in which an image is completed by a plurality of recording scans on the same area of a recording medium. Here, a two-pass multi-pass printing method in which an image is completed by two printing scans is illustrated. FIG. 5A shows the position of the recording head 31 in the sub-scanning direction in a plurality of recording scans. The dots recorded by one nozzle in one recording scan are obtained by thinning the recording data by about half according to a predetermined mask pattern.

  6A and 6B show an example of a mask pattern applicable to 2-pass multi-pass printing. 6A shows a mask pattern applied to the upper four nozzles, and FIG. 6B shows a mask pattern applied to the lower four nozzles. Each square indicates a pixel area to which one dot is addressed, and a black area indicates a pixel that allows dot recording, and a white area indicates a pixel that does not allow dot recording. 6A and 6B are complementary to each other.

  In an image area having an arbitrary 4-nozzle width on the recording medium, the pattern shown in FIG. 6A is recorded by the upper 4 nozzles of the recording head in the first recording scan. Thereafter, the recording medium is conveyed in the sub-scanning direction by 4 nozzles, and the next second recording scanning is performed at that position. In the second recording scan, the pattern shown in FIG. 6B is recorded by the lower four nozzles of the recording head. Since the patterns in FIGS. 6A and 6B are complementary to each other, the recording of the image area is completed by the above-described two recording scans.

  When such a multi-pass printing method is used, even if the same print head as shown in FIG. 4 is used, the influence of the variation unique to each nozzle on the print image is halved. That is, the recorded image is as shown in FIG. 5B, and black and white stripes as shown in FIG. 4B are not noticeable. As a result, the density unevenness is reduced as compared with the case of FIG. 4 as shown in FIG.

  In addition, the multi-pass printing method can reduce not only density unevenness due to nozzle variation but also occurrence of black and white stripes due to conveyance variation of the recording medium. Then, density unevenness repeated in the sub-scanning direction can be reduced, and the uniformity of the image can be improved. However, since the number of recording scans for completing an image of one page is increased, the recording time is also increased. Therefore, a general inkjet recording apparatus has a plurality of recording modes such as a mode for performing multi-pass recording and a mode for recording an image in one pass without performing multi-pass recording according to the required image quality and recording speed. Often prepared.

  By the way, in recent ink jet recording apparatuses, there is an increasing demand for higher resolution image output. In order to meet this requirement, a method has been proposed in which dots are recorded at a higher density than the arrangement pitch of nozzles arranged in the recording head in the sub-scanning direction (see, for example, Patent Document 2). . In this method, in a transport operation performed between the respective recording scans, the recording medium is transported by an amount that is not an integral multiple of the nozzle array pitch, thereby realizing recording with a resolution higher than the nozzle array pitch. As for the carry amount of the carry operation performed between each recording scan, there are a method of repeating a constant carry amount and a method of alternately repeating a plurality of types of carry amounts. However, if a plurality of pixels arranged in the sub-scanning direction are recorded by a plurality of recording scans sandwiching the recording medium conveyance operation, such a recording method is collectively referred to as an interlace recording method.

  The multi-pass printing method and the interlace printing method are identical in that the same image area of the printing medium is completed by a plurality of printing scans. However, in this specification, a method of recording a plurality of pixels arranged in the main scanning direction while using a mask pattern by a plurality of recording scans sandwiching a recording medium conveyance operation is referred to as a multi-pass recording method. A method of recording a plurality of pixels arranged in a scanning direction at a higher density than the arrangement pitch of the nozzles by a plurality of recording scans sandwiching a recording medium conveyance operation is referred to as an interless recording method.

  FIG. 7 is a schematic diagram for explaining a specific example of the interlace recording method. Here, an example in which an image of 1200 × 1200 dpi is recorded using the recording head 102 shown in FIG. Further, in this example, the mask pattern shown in FIG. 6 is used, and two-pass multi-pass printing is simultaneously performed.

  The circles shown on the right side of the figure indicate the dots recorded in a certain image area and their recording order. The recording head at the positions indicated as the first scan to the fourth scan is an enlarged part of the recording head 102 shown in FIG. Since a predetermined transport operation is performed for each recording scan, the nozzles of the recording head 102 corresponding to the image area are different for each recording scan.

  FIG. 8 is a flowchart for explaining the operation steps of the recording apparatus in realizing the interless recording of this example. When image data is input, first, in step S1501, the recording medium is fed into the apparatus.

  In subsequent step S1502, the recording head 102 waiting at the home position records dots according to the mask pattern shown in FIG. 6 while moving in the X direction (forward direction). As a result, the first scan is executed. At this time, in the image area shown in FIG. 7, the nozzles of the recording head are arranged as shown in the first scan in FIG. Then, with the mask pattern shown in FIG. 6A, dots indicated by “1” are recorded in the first scan.

  Next, in step S1503, the recording medium P is conveyed by the paper feed roller 153 for 9.5 nozzles (19 dots of 1200 dpi) in the + Y direction. By this carrying operation, the nozzles of the recording head are arranged at the positions shown as the second scan in FIG. 7 with respect to the image area in FIG.

  In step S1504, the recording head 102 records dots while moving in the -X direction (return path direction). As a result, the second scan is executed. The nozzle position of the second scan is shifted by a half pitch (one pixel of 1200 dpi) with respect to the nozzle position of the first scan. Therefore, the dot indicated by ２2 is recorded in the second scan by the mask pattern of FIG.

  In step S1505, the recording medium P is conveyed by the paper feed roller 153 for 10.5 nozzles (21 dots of 1200 dpi) in the + Y direction. By this transport operation, the nozzles of the recording head are arranged at the positions shown as the third scan in FIG. 7 with respect to the image area in FIG.

  In step S1506, it is determined whether data to be recorded still remains. If it is determined that there remains data to be recorded, the process returns to step S1502 to execute the third scan.

  The third scan is the same operation as the first scan, but is the third recording scan for the image area of FIG. Since dots are recorded by the lower half area of the recording head, dots indicated by ○ 3 by the mask pattern in FIG. 6B are recorded in the third scan. Further, in step S1504 after the carrying operation is performed, the fourth recording scan is performed on the image area. With the mask pattern shown in FIG. 6B, dots indicated by “4” are recorded.

  As described above, by repeating steps S1501 to S1506, a 1200 dpi image is gradually formed on the recording medium.

  If it is determined in step S1506 that there is no data to be recorded, the process proceeds to step S1507, and the recording medium is discharged. This process is completed.

  By performing the above-described interlaced recording and multi-pass recording, it is possible to output a high-resolution and uniform high-quality image.

  Incidentally, in recent years, many inkjet recording apparatuses have been provided that realize so-called marginless recording in which an image is output without providing margins at the leading edge, the trailing edge, or the left and right edges of a recording medium. When realizing printing without margins, the most serious problem is that when ink is applied to the outermost portion of the recording medium, the inside of the apparatus is contaminated by the ink protruding from the outermost portion. Further, when recording the leading end portion and the trailing end portion of the recording medium, the support and conveyance accuracy of the recording medium become unstable, and image degradation due to this becomes a problem. Therefore, in the ink jet recording apparatus that realizes recording without margins, various contrivances have been made to overcome the above-mentioned problems.

  FIGS. 9A to 9C are cross-sectional views illustrating examples of a recording unit when the inkjet recording apparatus illustrated in FIG. 1 is configured to be capable of recording without margins. In the figure, reference numeral 108 denotes a platen for supporting the recording medium from below, and reference numeral 107 denotes an ink absorber provided in a predetermined area of the platen. The ink absorber 107 plays a role of absorbing ink ejected from the outermost portion when recording the outermost portion of the recording medium.

  In the three drawings, FIG. 9A shows a case where the ink absorber 107 has the same length as the nozzle row of the recording head 102. FIGS. 9B and 9C show a state in which the length of the ink absorber is reduced to about ½ as compared with FIG. 9A, and the ink absorber 107 is connected to the paper feed roller pair 105. FIG. 9B shows a state of being disposed in a portion farther from the center, and FIG. 9C is a state of being disposed in a closer portion.

  In the case of FIG. 9A, since the ink absorber is provided at a position where all the nozzles are opposed to each other, all the nozzles are caused without causing contamination in the apparatus regardless of the front end portion or the rear end portion of the recording medium. Ink can be ejected using. However, since the ink absorber 107 is long, the area of the platen 108 that supports the recording medium from the bottom is short, and the support of the recording medium tends to be insufficient. In particular, when recording the leading edge and the trailing edge of the recording medium, the recording medium is supported by only one of the pair of paper feed rollers 105 or the pair of transport rollers 103 and spurs 104. Therefore, when the leading edge of the recording medium is curled as shown in the figure, the leading edge easily falls into the ink absorber, which may cause contamination of the recording medium or conveyance failure.

  Therefore, as shown in FIGS. 9B and 9C, an ink absorber 107 having a length shorter than the entire length of the nozzle row is provided while the platen 108 area is secured to some extent, and the leading end and the trailing end are recorded. In this case, it is preferable that ink is ejected by some nozzles of the recording head. As described above, when the number of nozzles used for recording is reduced only at the front end portion and the rear end portion of the recording medium, the conveyance amount of the recording medium performed between each recording scan is also reduced.

  Patent Document 3 and the like disclose a recording method for realizing marginless recording while performing interless recording. This document describes in detail how the number of nozzles used for recording and the conveyance amount of the recording medium are gradually reduced (or increased) at the leading end or the trailing end of the recording medium.

  As described above, the recording method in which the number of nozzles used for recording and the conveyance amount of the recording medium are changed within a page is not effective only when realizing marginless recording. Regardless of the presence or absence of margins, image problems are likely to occur at the leading edge and the trailing edge of the recording medium due to the limitations of the transport mechanism. Even in such a case, the recording method described above can function effectively.

  10A to 10C are cross-sectional views for explaining a conveyance problem at the front and rear end portions of the recording medium. FIG. 10A shows a state where the central portion of the recording medium is being recorded. The recording medium P is sandwiched and stretched by two pairs of rollers, that is, a pair of paper feed rollers 105 and a pair of rollers of a conveyance roller 103 and a spur 104, and a state in which a plane is maintained is maintained. That is, the distance from the ejection port surface of the recording head 102 to the recording medium P (hereinafter referred to as the inter-paper distance) is also maintained at a constant value Z1.

  FIG. 10B shows a state where the leading end portion of the recording medium is recorded, and FIG. 10C shows a state where the trailing end portion of the recording medium is recorded. At the front end and rear end, the recording medium P can be supported only by one roller pair. Therefore, the conveyance accuracy of the recording medium is lower than that in FIG. 10A, and the distance between the papers at the end is also unstable. In the figure, the end of the recording medium is lifted, and shows a state in which the distance between sheets Z2 or Z3 is smaller than Z1.

  When the conveyance amount of the recording medium and the distance between sheets become unstable, the arrangement of dots recorded on the recording medium is also affected. For example, if the carry amount varies, white stripes and black stripes occur irregularly on the image. In addition, when multipass printing or interlace printing is performed, the complementary relationship between dots is impaired, and there is a concern about density unevenness in units of scanning width. Furthermore, the change in the distance between papers changes the time until the ink droplets ejected from the recording head reach the recording medium. In the case of the serial type ink jet recording apparatus as in this example, such a variation in time appears as a dot position shift in the carriage traveling direction. That is, even in this case, since the complementary relationship between the print scans is lost, density unevenness in units of scan width is caused.

  However, even in a situation where the above-described adverse effects can occur, it is possible to suppress the above-described adverse effects to some extent by reducing the number of nozzles used in the recording head and the conveyance amount of the recording medium. This is because, for example, the transport amount is affected by the size of the transport amount, and can be reduced by reducing the transport amount itself. Also, with regard to the inter-paper distance, the inter-paper distance can be made closer to Z1 by using a nozzle closer to the pair of rollers that support and convey the recording medium. Therefore, in a recording apparatus that performs recording without margins, or in a recording apparatus that attempts to maintain high image quality at the leading edge and trailing edge, depending on the recording position of the recording medium, the number of nozzles used and the conveyance amount of the recording medium The change is controlled appropriately.

  FIG. 11 is a flowchart for explaining an operation process of the recording apparatus in realizing marginless recording. Here, a case is shown in which the printing apparatus of FIG. 1 and the printing head of FIG. 2 are used and 4-pass multi-pass printing is performed without performing interlaced printing. In this example, it is assumed that the position of the ink absorber faces the nozzle located on the upstream side of the recording head, as shown in FIG. 9C.

  FIGS. 12A to 12D are schematic views showing mask patterns applied in the 4-pass multi-pass printing of the present example in the same manner as FIG. However, in this example, it is assumed that one type of mask pattern is applied over the entire nozzle row in the same print scan, and the mask pattern applied for each print scan is sequentially switched. FIG. 12A shows a mask pattern applied in the 4n + 1 scan (n is an integer of 0 or more), and FIG. 12B shows a mask pattern applied in the 4n + 2 scan. c) is a mask pattern applied in the 4n + 3 scanning scan, and FIG. 10D is a mask pattern applied in the 4n scanning scan. The mask patterns in FIGS. 12A to 12D are complementary to each other.

  When image data is input, first, in step S1001, the recording medium is fed into the apparatus. In subsequent step S1002, recording is performed on the leading end portion of the recording medium.

  FIGS. 13A to 13F are schematic diagrams for explaining the recording operation of each step in the multi-pass recording of this example. Here, FIG. 13A shows the recording operation in step S1002, that is, the recording operation on the leading end of the recording medium. The recording heads at the positions indicated as the first to fifth scans in the figure indicate the positions of the recording heads for each recording scan with respect to the recording medium P.

  In this example, since the multi-pass printing of 4 passes is performed using the 40-nozzle print head 102, the print head 102 can be considered divided into 4 areas by 10 nozzles. In the following description, for the sake of convenience, the 40 nozzles arranged in the recording head will be described in the order of 1, 2,.

  In step S1002, a recording operation is performed on the leading end of the recording medium. In the recording apparatus of this example, as shown in FIG. 9C, an ink absorber is arranged at a position facing the nozzle located on the upstream side of the recording head. Therefore, when recording is performed on the extreme end of the recording medium, 30 nozzles 11 to 40 are used.

  In the first scan, the main scan is performed in the + X direction while using the mask pattern of FIG. 12A, and then the recording medium is conveyed by 10 nozzles in the sub-scan direction. In the subsequent second print scan, main scan in the −X direction is performed using the mask pattern of FIG. No transport operation is performed between the second and third scans. In the third scan, main scanning is performed in the + X direction while using the mask pattern of FIG. 12C, and then the recording medium is conveyed by 10 nozzles in the sub scanning direction. Further, in the fourth scan, main scanning is performed in the −X direction while using the mask pattern of FIG. 12D, and then the recording medium is conveyed by 10 nozzles in the sub scanning direction. Thereafter, the same recording scan and transport operation are repeated.

  In the figure, attention is paid to an area recorded by the nozzles 31 to 40 in the first scan, for example. This area includes a pattern C1 recorded from the 31st nozzle to the 40th nozzle in the first scan using the mask pattern of FIG. 12A and 21 nozzles in the second scan using the mask pattern of FIG. 12B. The pattern C2 recorded from the first nozzle to the 30th nozzle, the pattern C3 recorded from the 21st nozzle to the 30th nozzle in the third scan using the mask pattern of FIG. 12C, and the mask pattern of FIG. The image is completed by superimposing the pattern C4 recorded by using 20 nozzles from 11 nozzles in the fourth scan.

  For example, let us focus on the area recorded by the nozzles 31 to 40 in the second scan. This area includes the pattern D2 recorded from the 31st nozzle to the 40th nozzle in the second scan using the mask pattern in FIG. 12B, and the 31 nozzle in the third scan using the mask pattern in FIG. 12C. A pattern D3 recorded from the 40th nozzle to the 40th nozzle, a pattern D4 recorded from the 21st nozzle to the 30th nozzle in the fourth scan using the mask pattern of FIG. 12D, and the mask pattern of FIG. The image is completed by superimposing the pattern D1 recorded from the 11th nozzle to the 20th nozzle on the fifth scan. When the recording operation in the vicinity of the leading end as described above ends, the process proceeds to step S1003.

  In step S1003, a recording operation is performed to shift from recording using the nozzles 11 to 40 for the tip portion to recording using all the nozzles. FIG. 13B shows the recording operation in step S1003. First, in the first scan, main scanning in the + X direction is performed by the nozzles 11 to 40 while using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 11 to 40 while using the mask pattern of FIG. Thereafter, the recording medium is again conveyed by 10 nozzles in the sub-scanning direction. In the third scan, main scanning in the + X direction is performed by the nozzles 1 to 40 while using the mask pattern of FIG. 12C, and then the recording medium is transported by 10 nozzles in the sub-scanning direction. Further, in the fourth scan, main scanning in the −X direction is performed by the nozzles 1 to 40 using the mask pattern of FIG. 12D, and then the recording medium is transported by 10 nozzles in the sub scanning direction. The fifth scan can be regarded as the first recording scan in the normal area described below. Above, the process of step S1003 is complete | finished.

  In subsequent step S1004, recording is performed using all nozzles for the normal area. In this example, the normal area indicates an area in which recording can be performed in a state where the recording medium is sandwiched between two pairs of rollers, that is, the paper feed roller pair 105 and the conveyance roller 103 and the spur roller 104 pair.

  FIG. 13C shows the recording operation in step S1004. First, in the first scan, the main scan in the + X direction is performed by all the nozzles while using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by all the nozzles while using the mask pattern of FIG. Thereafter, the recording medium is again conveyed by 10 nozzles in the sub-scanning direction. In the third scan, main scanning in the + X direction is performed by all the nozzles using the mask pattern of FIG. 12C, and then the recording medium is transported by 10 nozzles in the sub-scanning direction. Further, in the fourth scan, main scanning in the −X direction is performed by all the nozzles using the mask pattern of FIG. 12D, and then the recording medium is conveyed by 10 nozzles in the sub scanning direction. After the fifth scan, the first to fourth scans described above are repeated. When the recording progresses and the rear end of the recording medium approaches the process of removing from the paper feed roller, the process proceeds to step S1005.

  In step S1005, a recording operation for shifting from recording using all nozzles to recording using nozzles 11 to 40 for the rear end portion is performed. FIG. 13D shows the recording operation in step S1005. First, in the first scan, main scanning in the + X direction is performed by the nozzles 1 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. No conveyance operation is performed between the second and third scans. In the third scan, the main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. 12C, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. Further, in the fourth scan, main scanning in the −X direction is performed by the nozzles 11 to 40 while using the mask pattern of FIG. 12D, and then the recording medium is conveyed by 10 nozzles in the sub scanning direction. In the fifth scan, the main scan in the + X direction is performed by the nozzles 11 to 40 while using the mask pattern of FIG. Thereafter, the recording operations from the second scan to the fifth scan are sequentially repeated.

  In step S1006, a unique recording operation is performed at the timing when the recording medium is removed from the paper feed roller. FIG. 13E shows the recording operation in step S1006. First, in the first scan, main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the third scan, the main scanning in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. 12C, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction.

  In this example, it is assumed that the recording medium comes off the paper feed roller 105 in the third scan. The transport amount at the moment when the recording medium passes through the paper feed roller tends to be larger than the set value because the recording medium is ejected from the paper feed roller. Therefore, as in this example, the influence of the transport error can be reduced by setting the transport amount at this timing to be larger than usual. Here, a recording operation for 10 nozzles is intentionally performed at a timing at which conveyance is not performed in normal rear end recording, that is, between the second recording scan and the third recording scan. In order to align the data positions, the area of the used nozzles is shifted from 11 nozzles to 40 nozzles to 1 nozzle to 30 nozzles.

  In the fourth scan, main scanning in the −X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. 12D, and then the recording medium is conveyed by 10 nozzles in the sub scanning direction. In the fifth scan, main scanning in the + X direction is performed by the nozzles 1 to 30 while using the mask pattern of FIG. The fifth scan can be regarded as the first recording scan of the rear end area described below. Above, the process of step S1006 is complete | finished.

  In step S1007, a recording operation for returning the used nozzle position from the state of nozzles 1 to 30 to the nozzles 11 to 40 is performed. In step S <b> 1006, the used nozzle position is shifted from nozzle 1 to nozzle 30 in order to reduce the conveyance error at the moment when the recording medium is detached from the pair of paper feed rollers 105. However, as shown in FIG. 9C, the ink absorber of the recording apparatus of this example is opposed to the nozzle row located on the upstream side in the transport direction. Therefore, when recording the outermost portion in the marginless recording, it is necessary to perform the recording by the nozzle on the more upstream side.

  FIG. 13F shows the recording operation in step S1007. First, in the first scan, main scanning in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, the main scanning in the −X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. No conveyance operation is performed between the second and third scans. In the third scan, main scanning in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. The conveying operation is not performed between the third scan and the fourth scan. Further, in the fourth scan, the main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. 12D, and then the recording medium is transported by 10 nozzles in the sub scanning direction. In the fifth scan, main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. This fifth scan can be regarded as the first recording scan of the last end area described below.

  In step S1008, the final recording is performed on the last end area of the recording medium. The recording operation here is equivalent to the recording operation in step S1002 described with reference to FIG.

  When the recording in the rear end area is completed, the process advances to step S1009 to discharge the recording medium. This is the end of the marginless recording operation for one page.

  As described above, recent inkjet recording apparatuses can output high-definition images with high quality by performing interlaced recording or multi-pass recording. On the other hand, it is also possible to realize marginless recording without reducing image quality by appropriately adjusting the conveyance amount and the number of nozzles used.

Japanese Patent Laid-Open No. 06-143618 USP 4,198,642 specification JP 2002-103584 A

  However, as a result of intensive studies by the present inventors, when a recording method in which the conveyance amount and the number of used nozzles are changed in the middle of the page, such as recording without margins, while performing interlaced recording, new density unevenness is obtained. Was confirmed to occur.

  When performing interlaced printing, dots are always complemented by a plurality of printing scans in an image area corresponding to the width of the nozzle pitch (hereinafter referred to as a unit area). For example, in the case of FIG. 7 described above, an image of 1200 dpi is formed using a nozzle row having a 600 dpi pitch. In this case, the unit area is an area having a width of two pixels in the sub-scanning direction. In the example of FIG. 7, the lower part of the unit area is recorded by the first and third scans, and the upper part is recorded by the second and fourth scans. What is the relationship between the recording order of the dots arranged in the unit area? The same applies to the unit area. Hereinafter, the order of the dots recorded in the unit area will be referred to as a phase, the first dot recorded in the unit area will be referred to as the first phase, the second dot recorded in the unit area as the second phase, and so on. .

  FIG. 14 is realized in a unit area of 2 pixels × 2 pixels when performing an interless recording method in which dots are recorded at a resolution twice the nozzle pitch as shown in FIG. 7 and 2-pass multi-pass printing at the same time. FIG. 6 shows various possible phase states. Here, FIG. 14A shows the same phase state as FIG. That is, dots are recorded in the first phase at the lower left of the unit area, the second phase at the upper right, the third phase at the lower right, and the fourth phase at the upper left, and this state continues in the main scanning direction. On the other hand, FIGS. 14B to 14D show phase states different from those in FIG. Such a difference in the phase state appears by changing the carrying amount of the carrying operation performed between printing scans and the mask pattern to be applied.

  FIG. 15 shows various states of phases that can be realized in the unit area in the case of performing interlaced recording in which dots are recorded at a resolution four times the nozzle pitch without using multi-pass recording. FIG. Since multi-pass printing is not performed, all dots arranged in the main scanning direction are printed in the same phase, but various phase states can be assumed for the 4-pixel width arranged in the sub-scanning direction. Such a difference in phase state appears due to a difference in the transport amount of the transport operation. In other words, there is a possibility that unit areas of different phase states exist on the same page when changing the carry amount or mask in the middle, such as when performing marginless recording while performing interlaced recording. Occurs.

  According to the study by the present inventors, it was confirmed that the density of the unit area or some other characteristic is determined by the phase state recorded in the unit area.

  FIG. 16 is a schematic diagram for explaining a fixing state when two ink droplets are continuously recorded at adjacent positions. If the previously recorded ink is already sufficiently fixed at the timing when the subsequently recorded ink is recorded, the subsequently recorded ink remains on the surface of the recording medium and has a relatively high density. Can be expressed. On the other hand, if the previously recorded ink is not yet sufficiently fixed, the subsequently recorded ink wraps around below the previously recorded ink and expresses a very high density. Can not do.

  That is, when the above phenomenon is applied to a phase, the color density of a unit area that is recorded in a phase that is spaced as much as possible with respect to adjacent pixels and a unit area that is recorded in a continuous phase are as follows. Will be different. In other words, when changing the carry amount or mask in the middle while performing interlaced recording, there are unit areas of different densities in the same page due to the difference in phase state, which is confirmed as uneven density. There is a possibility that

  Furthermore, when performing bidirectional recording, the characteristics of the unit region may vary depending on how the dots recorded by the forward scan and the dots recorded by the backward scan are dispersed in the unit region. It depends.

  FIG. 17 is a diagram schematically showing landing states of main ink droplets and satellites recorded in a unit area when interless recording is performed by bidirectional recording scanning. Ink droplets ejected from each nozzle of the ink jet recording head may be divided into main droplets 111 and minute sub-droplets called satellites 112. In this case, the satellite 112 has a slower discharge speed than the main droplet, and the time until landing on the recording medium is longer than that of the main droplet. Since the recording head discharges while moving in the main scanning direction, such a time difference between the main droplet 111 and the satellite 112 appears as a recording position shift in the main scanning direction. That is, the satellite is landed on the main droplet at a position shifted in the traveling direction of the recording head, and the satellite position with respect to the main droplet is reversed between the forward scan and the backward scan.

  FIG. 17A is a diagram showing a recording state of main droplets and satellites in a unit area when bidirectional recording is performed in the phase state of FIG. 14A. In the area of the lower stage 114 recorded in the first scan and the third scan, satellites are always recorded on the right side of the main droplet. On the other hand, in the area of the upper stage 113 recorded in the second and fourth scans, satellites are always recorded on the left side of the main droplet.

  On the other hand, FIG. 17B shows a case where bidirectional recording is performed in the phase state of FIG. In both the area of the lower stage 114 and the area of the upper stage 113, the dots on which the satellite is recorded on the right side of the main droplet and the dots on which the satellite is recorded on the left side of the main droplet are arranged alternately and evenly.

  FIG. 18 is a diagram showing a recording operation in the case where the steady region as shown in FIG. 10A is recorded using all the nozzles by the interlaced recording method described in FIG. First, in the first scan, main scanning in the + X direction is performed by all the nozzles using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the subsequent second recording scan, the main scan in the −X direction is performed by all the nozzles using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10.5 nozzles in the sub-scanning direction. In the third scan, the main scanning is performed in the + X direction by all the nozzles using the mask pattern of FIG. 12C, and then the recording medium is transported by 9.5 nozzles in the sub scanning direction. Further, in the fourth scan, the main scanning in the −X direction is performed by all the nozzles using the mask pattern of FIG. 12D, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. After the fifth scan, the steps of the first scan to the fourth scan described above are sequentially repeated.

  The number of recording scans (1 scan, 2 scans...) Gradually increases, but dots included in the unit area are always recorded in four consecutive phases from the first phase to the fourth phase. In the steady region where the regular recording operation as described with reference to FIG. 18 is repeated, the phase state is the state shown in FIG. 14A in all the unit regions, and the satellite recording state is as shown in FIG. 17 (a).

  On the other hand, in the front end area, the rear end area, or the area before and after the recording medium is removed from the paper feed roller, the recording medium conveyance amount is 10.5 nozzles, 0 nozzles, 9.5 nozzles, Repeat for 0 nozzles. Thus, by changing the carry amount with respect to the normal area, the phase state of the area is changed as shown in FIG. The satellite recording state is as shown in FIG. That is, the density and characteristics in the unit area are different between the steady area and the front end area, the rear end area, or the area before and after the recording medium is removed from the paper feed roller.

  As for the recording state of the satellite, in any of the states shown in FIGS. 17A and 17B, if the unit region having either feature extends over the entire area of the page, there is a large image problem. Don't be. However, as shown in FIGS. 17A and 17B, if unit areas having different satellite recording states exist in the same page, this is perceived as uneven density.

  As described above, various methods have been proposed for the interless recording method, and the recording method described here is only an example. For example, Patent Document 3 discloses a recording method in which an interlace recording method different from the above example and a marginless recording are combined. However, in any conventional method, attention is not paid to unifying the phase state in the unit area in all areas in the page, and the above problem remains unsolved.

  The present invention has been made in view of the above problems, and the object of the present invention is to change the transport amount of the recording medium and the number of nozzles used for recording within the same page while changing the phase state in the unit area. Is to be constant in the entire area of the page, thereby providing an ink jet recording method capable of realizing a high-definition image without density unevenness by an interlace recording method.

Therefore, in the present invention, a recording head in which a plurality of nozzles for ejecting ink are arranged in the sub-scanning direction at a pitch of 2 × d is used, and the recording head is scanned in the main scanning direction intersecting the sub-scanning direction. By intermittently repeating a recording scan for ejecting ink from the nozzles to record dots on a recording medium and a sub-scan for conveying the recording medium in the sub-scanning direction, the recording medium in the sub-scanning direction In the ink jet recording method for recording an image so that dots are arranged at a pitch of d, the transport amount l of the sub-scan is 1 = 0, l = K × 2 × d , (K−1) × 2 × d < At least four types of l <K × 2 × d , K × 2 × d <l <(K + 1) × 2 × d (K is a positive integer) are prepared, and a recording scan using M nozzles, Transfer operation of any of the four types of transfer amount Printing operation step A for alternately executing sub-scanning, printing scanning using N (<M) nozzles in a fixed area among the plurality of arranged nozzles, and any one of the four types A recording operation step B that alternately executes a sub-scan that performs a conveying operation for a conveying amount, a recording scan that uses N (<M) nozzles in a non-fixed region among the plurality of arranged nozzles, and the 4 And a recording operation step C that alternately executes sub-scanning for carrying a carrying operation of any kind of carrying amount, and recording dots for a plurality of pixels arranged in the main scanning direction of the printing medium, In the recording operation step A, it is performed while complementing by a plurality of recording scans. In the recording operation step A, 1 = K × 2 × d , (K−1) × 2 × d <l <K × 2 × d , and K × 2 × d <l <(K + 1) sub-scan to achieve the transport of × 2 × d At least comprises, in the above recording operation step B, l = K × 2 × d , (K-1) × 2 × d <l <K × 2 × d, and K × 2 × d <l < (K + 1) × The ratio of the number of times of sub-scanning that includes at least a sub-scan that realizes a transport amount of 2 × d and that realizes a transport amount of l = 0 is higher than that in the recording operation step A. In the recording operation step C, l At least a sub-scan that realizes a carry amount of K × 2 × d , (K−1) × 2 × d <l <K, and K × 2 × d <l <(K + 1) × 2 × d , and The ratio of the number of times of sub-scanning that realizes the carry amount of l = 0 is further higher than the ratio of the recording operation step B.

Further, a recording head in which a plurality of nozzles for ejecting ink are arranged in the sub-scanning direction at a pitch of 2 × d is used, and ink is ejected from the nozzles while scanning the recording head in the main scanning direction intersecting the sub-scanning direction. By intermittently repeating a recording scan for discharging and recording dots on the recording medium and a sub-scan for conveying the recording medium in the sub-scanning direction, dots are printed at a pitch of d in the sub-scanning direction of the recording medium. In the ink jet recording method for recording an image so as to be arranged, the transport amount l of the sub-scan is 1 = 0, l = K × 2 × d , (K−1) × 2 × d <l <K × 2 At least four types of × d , K × 2 × d <l <(K + 1) × 2 × d (K is a positive integer) are prepared, and N nozzles in a fixed region among the plurality of arranged nozzles Any of the above four types A recording operation step B for alternately executing sub-scanning for carrying a carrying operation of a carry amount, a printing scan using N nozzles in a non-fixed region among the plurality of arranged nozzles, and any of the four types And a recording operation step C that alternately executes sub-scanning for carrying a certain amount of carrying operation, and dot printing for a plurality of pixels arranged in the main scanning direction of the printing medium is performed a plurality of times. In the recording operation step B, it is performed while complementing by the recording scan. In the recording operation step B, 1 = K × 2 × d, (K−1) × 2 × d <l <K × 2 × d , and K × 2 × d. <L <(K + 1) × 2 × d including at least a sub-scan that realizes a carry amount. In the recording operation step C, l = K × 2 × d , (K−1) × 2 × d <l < K, and K × 2 × d <l <a (K + 1) sub-scan to achieve the transport of × 2 × d small Ku and also includes, and the ratio of the number of sub-scan for realizing the transport amount of the l = 0 is equal to or higher than the ratio of the recording operation step B.

  According to the present invention, characteristics such as density and area factor are unified in all unit areas in the page, so that density unevenness in the page is reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
In this embodiment, the ink jet recording apparatus shown in FIG. 1 and the recording head shown in FIG. 2 are applied.

  FIG. 19 is a block diagram for explaining a control configuration of the ink jet recording apparatus according to the present embodiment. In the figure, reference numeral 1305 denotes a main bus line for allowing individual functional components to access each other. The individual functional configurations for accessing the main bus line 1305 include a software processing configuration such as an image input unit 1303, an image signal processing unit 1304, and a central control unit CPU 1300, an operation unit 1306, a recovery system control circuit 1307, a head. It is roughly divided into hardware processing configurations such as a temperature control circuit 1314, a head drive control circuit 1315, a carriage drive control circuit 1316, and a paper feed control circuit 1317.

  The CPU 1300 includes a ROM 1301, a RAM 1302, and an EEPROM 1318. The CPU 1300 gives appropriate recording conditions to the information input to the image input unit 1303, and drives the recording head 102 to execute ejection.

  In the ROM 1301, a program for executing a recovery timing chart of the recording head is stored in advance. The CPU 1300 reads recovery conditions such as preliminary ejection conditions from the ROM 1301 as necessary, and controls the recovery system control circuit 1307, the recording head 102, the heat retaining heater, and the like according to the read conditions. The recovery system motor 1308 drives the cleaning blade 1309, the cap 1310, and the suction pump 1311 that face and separate from the recording head 102. The head drive control circuit 1315 executes driving of the electrothermal transducers provided in the individual nozzles of the recording head 102, and causes the recording head 102 to execute preliminary ejection and ink ejection for recording.

  On the other hand, the substrate of the recording head 1102 is provided with a heat retaining heater, and the ink temperature in the recording head can be heated and adjusted to a desired set temperature. A diode sensor 1312 is also provided on the same substrate, and can measure the ink temperature inside the recording head. However, the diode sensor 1312 is not necessarily provided on the substrate of the recording head, and may be provided outside the recording head or in the vicinity of the periphery of the recording head.

  In the present embodiment, the recording head corresponding to 600 dpi shown in FIG. 2 is used, and a 1200 × 1200 dpi image is recorded without a margin by an interlace recording method. At this time, a two-pass multipass printing method is simultaneously performed using the mask pattern shown in FIG.

  In this example as well, FIG. 11 can be applied as a flowchart for explaining the operation process of the recording apparatus in realizing marginless recording. Hereinafter, a specific recording operation of the present embodiment will be described corresponding to each step of FIG.

  20A to 20F are schematic diagrams for explaining the recording operation of each step of the present embodiment. Here, FIG. 20A shows the recording operation in step S1002, that is, the recording operation with respect to the leading end portion of the recording medium. In step S1002, a recording operation is performed on the leading end of the recording medium. In the recording apparatus of the present embodiment, as shown in FIG. 9C, an ink absorber is provided at a position facing the nozzle located on the upstream side of the recording head. Therefore, when recording is performed on the extreme end of the recording medium, 30 nozzles 11 to 40 are used.

  In the first scan, using the mask pattern shown in FIG. 6A, main scanning is performed in the + X direction by the nozzles 11 to 40, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the third scan, the main scan in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. No transport operation is performed between the third and fourth scans. Further, in the fourth scan, the main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. Thereafter, the same recording scan and transport operation are repeated.

  In step S1003, a recording operation is performed to shift from recording using the nozzles 11 to 40 for the tip portion to recording using all the nozzles. FIG. 20B shows the recording operation in step S1003. First, in the first scan, main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern shown in FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the third scan, using the mask pattern of FIG. 6A, main scanning in the + X direction is performed by the nozzles 11 to 40, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. Further, in the fourth scan, main scanning in the −X direction is performed by the nozzles 1 to 40 while using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. . The fifth scan can be regarded as the first recording scan in the normal area described below. Above, the process of step S1003 is complete | finished.

  In subsequent step S1004, recording is performed using all nozzles for the normal area. In this example, the normal area indicates an area in which recording can be performed in a state where the recording medium is sandwiched between two pairs of rollers, that is, the paper feed roller pair 105 and the conveyance roller 103 and the spur roller 104 pair.

  FIG. 20C shows the recording operation in step S1004. First, in the first scan, the main scan in the + X direction is performed by all the nozzles using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, the main scan in the −X direction is performed by all the nozzles using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the third scan, the main scanning in the + X direction is performed by all the nozzles using the mask pattern of FIG. 6A, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. Further, in the fourth scan, the main scanning in the −X direction is performed by all the nozzles using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. After the fifth scan, the first to fourth scans described above are repeated. When the recording progresses and the rear end of the recording medium approaches the process of removing from the paper feed roller, the process proceeds to step S1005.

  In step S1005, a recording operation for shifting from recording using all nozzles to recording using nozzles 11 to 40 for the rear end portion is performed. FIG. 20D shows the recording operation in step S1005. First, in the first scan, main scanning in the + X direction is performed by the nozzles 1 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, the main scanning in the −X direction is performed by the nozzles 1 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the third scan, the main scan in the + X direction is performed by the nozzles 1 to 40 using the mask pattern of FIG. No conveying operation is performed between 3 and 4 scans. Further, in the fourth scan, the main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. In the fifth scan, the main scan in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG.

  In step S1006, a unique recording operation is performed at the timing when the recording medium is removed from the paper feed roller. FIG. 20E shows the recording operation in step S1006. First, in the first scan, main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern shown in FIG. Thereafter, the recording medium is conveyed by 20 nozzles in the sub-scanning direction. In the subsequent second scan, the main scan in the −X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG.

  In this example, it is assumed that the recording medium comes off the paper feed roller 105 in the second scan. The transport amount at the moment when the recording medium passes through the paper feed roller tends to be larger than the set value because the recording medium is ejected from the paper feed roller. Therefore, as in this example, the influence of the transport error can be reduced by setting the transport amount at this timing to be larger than usual. Here, in the normal rear end printing, the printing operation for 20 nozzles is performed at the timing of carrying 10 nozzles, that is, between the first printing scan and the second printing scan. In order to align the data positions, the area of the used nozzles is shifted from 11 nozzles to 40 nozzles to 1 nozzle to 30 nozzles.

  After the end of the second scan, the recording medium is transported by 9.5 nozzles in the sub-scanning direction. In the third scan, the main scan in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. No transport operation is performed between the third and fourth scans.

  In the fourth scan, using the mask pattern of FIG. 6B, main scanning in the −X direction is performed by the nozzles 1 to 30 and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. In the fifth scan, main scanning in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. The fifth scan can be regarded as the first recording scan of the rear end area described below. Above, the process of step S1006 is complete | finished.

  In step S1007, a recording operation for returning the used nozzle position from the state of nozzles 1 to 30 to the nozzles 11 to 40 is performed. In step S <b> 1006, the used nozzle position is shifted from nozzle 1 to nozzle 30 in order to reduce the conveyance error at the moment when the recording medium is detached from the pair of paper feed rollers 105. However, as shown in FIG. 9C, the ink absorber of the recording apparatus of this example is opposed to the nozzle row located on the upstream side in the transport direction. Therefore, when recording the outermost portion in the marginless recording, it is necessary to perform the recording by the nozzle on the more upstream side.

  FIG. 20F shows the recording operation in step S1007. First, in the first scan, main scanning in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. No conveying operation is performed between the first scan and the second scan. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the third scan, the main scan in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. The conveying operation is not performed between the third scan and the fourth scan. Further, in the fourth scan, the main scanning in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. In the fifth scan, the main scan in the + X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. This fifth scan can be regarded as the first recording scan of the last end area described below.

  In step S1008, the final recording is performed on the last end area of the recording medium. The recording operation here is equivalent to the recording operation in step S1002 described with reference to FIG.

  When the recording in the rear end area is completed, the process advances to step S1009 to discharge the recording medium. This is the end of the marginless recording operation for one page.

  In each of the recording processes in steps S1002 to S1008 described above, the conveyance amount of the recording medium, the number of nozzles used for recording, or the nozzle area are different from each other. However, in any process, the phase state in the unit area is unified to the state shown in FIG. That is, the unit area of any step can develop the same density, and the unit area of any step is in the same positional relationship between the main droplet and the satellite.

  FIG. 21 is a diagram schematically showing landing states of main ink droplets and satellites recorded in a unit area when interlaced recording according to the present embodiment is performed. Here, in both the lower stage 114 area and the upper stage 113 area, dots on which satellites are recorded on the right side of the main droplet and dots on which satellites are recorded on the left side of the main droplet are arranged alternately and evenly. In interlaced recording according to the present embodiment, the satellite recording state is the same in each step. Therefore, since the unit area having the same characteristic or area factor extends over the entire area of the page, the density unevenness as described in the problem section does not appear.

(Second Embodiment)
The second embodiment of the present invention will be described below. Also in this embodiment, the ink jet recording apparatus described with reference to FIGS. 1 and 19 is used. As the recording head, a nozzle in which nozzles are arranged at a pitch of 600 dpi as shown in FIG. 2 is used. However, in this embodiment, it is assumed that 80 nozzles are arranged on the recording head.

  Furthermore, in the present embodiment, a 2400 × 2400 dpi image is recorded without a margin by an interless recording method using a recording head corresponding to 600 dpi. At this time, a two-pass multipass printing method is simultaneously performed using the mask pattern shown in FIG.

  Also in the present embodiment, FIG. 11 can be applied as a flowchart for explaining the operation process of the recording apparatus in realizing marginless recording. Hereinafter, a specific recording operation of the present embodiment will be described corresponding to each step of FIG.

  22A to 22C are schematic diagrams for explaining the recording operation of each step of the present embodiment. Here, the first to third scans in FIG. 22A are excerpts of the recording operation in step S1002, that is, the recording operation for the leading end of the recording medium. In the recording apparatus of the present embodiment, as shown in FIG. 9C, an ink absorber is provided at a position facing the nozzle located on the upstream side of the recording head. Therefore, when recording is performed on the outermost end of the recording medium, 60 nozzles 21 to 80 are used.

  In the first scan, using the mask pattern shown in FIG. 6A, main scanning is performed in the + X direction by the nozzles 21 to 80, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the second scan, main scanning in the −X direction is performed by the nozzles 21 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10.5 nozzles in the sub-scanning direction. In the third scan, main scanning in the + X direction is performed by the nozzles 21 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction.

  Here, only the printing operation for three scans has been described, but actually, the printing of the tip end region is completed while alternately using the mask pattern of FIG. 6A and the mask pattern of FIG. 6B. The recording main scan is reciprocated. The conveyance amount of the recording medium after the end of each recording scan is 9.75 nozzles, 10 nozzles, 10.5 nozzles, 0 nozzles, 9.25 nozzles, 10 nozzles, 10.5 nozzles, 0 Repeat the nozzles sequentially.

  In step S1003, a recording operation for shifting from recording using the nozzles 21 to 80 for the tip portion to recording using all nozzles is performed. The third scan in FIG. 22A to the eighth scan in FIG. 22B show the printing operation in step S1003.

  The fourth scan following the third scan, using the mask pattern shown in FIG. 6B, main scanning is performed in the −X direction by the nozzles 11 to 80, and then 9.25 nozzles are printed in the sub-scanning direction. Carry a minute. In the fifth scan, main scanning in the + X direction is performed by the nozzles 11 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the sixth scan, the main scan in the −X direction is performed by the nozzles 11 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10.5 nozzles in the sub-scanning direction. In the seventh scan, the main scan in the + X direction is performed by the nozzles 11 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the eighth scan, the main scan in the −X direction is performed by the nozzles 1 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.75 nozzles in the sub-scanning direction. Then, step S1003 is completed.

  In subsequent step S1004, recording is performed using all nozzles for the normal area. In this example, the normal area indicates an area in which recording can be performed in a state where the recording medium is sandwiched between two pairs of rollers, that is, the paper feed roller pair 105 and the conveyance roller 103 and the spur roller 104 pair.

  The eighth to eleventh scans in FIG. 22B extract the recording operation in step S1004. Although shown in the drawing as an excerpt, in practice, a reciprocating recording main scan is performed using all the nozzles while alternately using the mask pattern of FIG. 6A and the mask pattern of FIG. 6B. The conveyance amount of the recording medium after the end of each recording scan is 9.75 nozzles, 10 nozzles, 10.5 nozzles, 10 nozzles, 9.25 nozzles, 10 nozzles, 10.5 nozzles, 10 Repeat for the nozzle. When the recording progresses and the rear end of the recording medium approaches the process of removing from the paper feed roller, the process proceeds to step S1005.

  In step S1005, a recording operation for shifting from recording using all nozzles to recording using nozzles 21 to 80 for the rear end portion is performed. The 11th scan in FIG. 22B to the 16th scan in FIG. 22C show the printing operation in step S1005.

  First, in the 11th scan, the main scan in the + X direction is performed by all the nozzles using the mask pattern of FIG. No conveying operation is performed between the 11th and 12th scans. In the 12th scan, using the mask pattern of FIG. 6B, the main scan in the −X direction is performed by the nozzles 11 to 80, and then the recording medium is conveyed by 9.25 nozzles in the sub scan direction. In the thirteenth scan, the main scan in the + X direction is performed by the nozzles 11 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the 14th scan, main scan in the −X direction is performed by the nozzles 11 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10.5 nozzles in the sub-scanning direction. In the fifteenth scan, main scanning in the + X direction is performed by the nozzles 11 to 80 using the mask pattern of FIG. No conveyance operation is performed between the 15th and 16th scans. In the 16th scan, main scan in the −X direction is performed by the nozzles 21 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.75 nozzles in the sub-scanning direction. Above, step S1005 is complete | finished and it transfers to step S1006.

  In step S1006, a unique recording operation is performed at the timing when the recording medium is removed from the paper feed roller. The 17th scan in FIG. 22C to the 19th scan in FIG. 22C show the printing operation in step S1006. First, in the 17th scan, main scanning in the + X direction is performed by the nozzles 21 to 80 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 30 nozzles in the sub-scanning direction. In the subsequent 18th scan, main scan in the −X direction is performed by the nozzles 1 to 60 using the mask pattern of FIG.

  In this example, it is assumed that the recording medium comes off the paper feed roller pair 105 at the 18th scan. The transport amount at the moment when the recording medium passes through the paper feed roller tends to be larger than the set value because the recording medium is ejected from the paper feed roller. Therefore, as in this example, the influence of the transport error can be reduced by setting the transport amount at this timing to be larger than usual. Here, in the normal rear end recording, the conveyance operation for 30 nozzles is performed at the timing of carrying 10 nozzles, that is, between the 17th and 18th scans. In order to align the data positions, the area of the used nozzles is shifted from 21 nozzles to 80 nozzles to 1 nozzle to 60 nozzles.

  After the 18th scan, the recording medium is conveyed by 10.5 nozzles in the sub-scanning direction. In the 19th scan, main scanning in the + X direction is performed by the nozzles 1 to 60 using the mask pattern of FIG. Above, the process of step S1006 is complete | finished.

  In step S1007, a recording operation for returning the used nozzle position from the state of nozzles 1 to 60 to the nozzles 21 to 80 is performed. In step S <b> 1006, the used nozzle position is shifted from nozzle 1 to nozzle 60 in order to reduce the transport error at the moment when the recording medium is detached from the pair of paper feed rollers 105. However, as shown in FIG. 9C, the ink absorber of the recording apparatus of this example is opposed to the nozzle row located on the upstream side in the transport direction. Therefore, when recording the outermost portion in the marginless recording, it is necessary to perform the recording by the nozzle on the more upstream side.

  The 19th to 24th scans in FIG. 22D show the printing operation in step S1007. First, in the 19th scan, main scanning in the + X direction is performed by the nozzles 1 to 60 using the mask pattern of FIG. No conveying operation is performed between the 19th and 20th scans. In the subsequent 20th scan, the main scan in the −X direction is performed by the nozzles 1 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.25 nozzles in the sub-scanning direction. In the 21st scan, main scanning in the + X direction is performed by the nozzles 1 to 60 using the mask pattern of FIG. No transport operation is performed between the 21st and 22nd scans. Further, in the 22nd scan, main scanning in the −X direction is performed by the nozzles 11 to 70 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. In the 23rd scan, main scanning in the + X direction is performed by the nozzles 11 to 70 using the mask pattern of FIG. No transport operation is performed between the 23rd and 24th scans. In the 24th scan, main scan in the −X direction is performed by the nozzles 21 to 80 using the mask pattern of FIG. Above, the process of step S1007 is complete | finished.

  In step S1008, the final recording is performed on the last end area of the recording medium. The recording operation here is equivalent to the recording operation in step S1002.

  When the recording in the rear end area is completed, the process advances to step S1009 to discharge the recording medium. This is the end of the marginless recording operation for one page.

  In each of the recording processes in steps S1002 to S1008 described above, the conveyance amount of the recording medium, the number of nozzles used for recording, or the nozzle area are different from each other. However, in any process, the phase state in the unit region is unified to an equivalent state.

  FIG. 23 is a diagram schematically showing the phase state of the unit area and the landing state of the satellite when the interlaced recording of the present embodiment is performed. Here, in any of the regions 181 to 184, dots on which satellites are recorded on the right side of the main droplet and dots on which satellites are recorded on the left side of the main droplet are arranged alternately and evenly. In the interlaced recording of the present embodiment, the satellite recording state and phase state shown here can be obtained in any unit area in the recording operation of steps S1002 to S1008. Therefore, since the unit area having the same characteristic or area factor extends over the entire area of the page, the density unevenness as described in the problem section does not appear.

(Third embodiment)
The third embodiment of the present invention will be described below. Also in this embodiment, the ink jet recording apparatus described with reference to FIGS. 1 and 19 is used. As the recording head, a nozzle in which nozzles are arranged at a pitch of 600 dpi as shown in FIG. 2 is used. However, in this embodiment, it is assumed that 60 nozzles are arranged on the recording head.

  Furthermore, in the present embodiment, a 1200 × 1200 dpi image is recorded without a margin by an interless recording method using a recording head corresponding to 600 dpi. At this time, a two-pass multipass printing method is simultaneously performed using the mask pattern shown in FIG.

  Also in the present embodiment, FIG. 11 can be applied as a flowchart for explaining the operation process of the recording apparatus in realizing marginless recording. Hereinafter, a specific recording operation of the present embodiment will be described corresponding to each step of FIG.

  In this example as well, FIG. 11 can be applied as a flowchart for explaining the operation process of the recording apparatus in realizing marginless recording. Hereinafter, a specific recording operation of the present embodiment will be described corresponding to each step of FIG.

  24A to 24F are schematic views for explaining the recording operation of each step of the present embodiment. Here, FIG. 24A shows the recording operation in step S1002, that is, the recording operation with respect to the leading end portion of the recording medium. In step S1002, a recording operation is performed on the leading end of the recording medium. In the recording apparatus of the present embodiment, as shown in FIG. 9C, an ink absorber is provided at a position facing the nozzle located on the upstream side of the recording head. Therefore, when recording is performed on the outermost end of the recording medium, 30 nozzles 31 to 60 are used.

  In the first scan, using the mask pattern shown in FIG. 6A, main scanning is performed in the + X direction by the nozzles 31 to 60, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent second recording scan, main scanning in the −X direction is performed by the nozzles 31 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the third scan, the main scan in the + X direction is performed by the nozzles 31 to 60 using the mask pattern of FIG. No transport operation is performed between the third and fourth scans. Further, in the fourth scan, the main scan in the −X direction is performed by the nozzles 31 to 60 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub-scan direction. Thereafter, the same recording scanning and conveying operation are repeated until the recording of the tip end region is completed.

  In step S1003, a recording operation for shifting from recording using the nozzles 31 to 60 for the tip portion to recording using all the nozzles is performed. FIG. 24B shows the recording operation in step S1003. First, in the fourth scan, main scanning in the + X direction is performed by the nozzles 31 to 60 using the mask pattern shown in FIG. Thereafter, the recording medium is conveyed by 20.5 nozzles in the sub-scanning direction. In the fifth scan, the main scan in the + X direction is performed by the nozzles 21 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent sixth scan, the main scan in the −X direction is performed by the nozzles 21 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 19.5 nozzles in the sub-scanning direction. In the seventh scan, main scanning in the + X direction is performed by the nozzles 11 to 60 using the mask pattern of FIG. 6A, and then the recording medium is conveyed by 10 nozzles in the sub-scanning direction. Further, in the eighth scan, main scanning in the −X direction is performed by the nozzles 1 to 60 while using the mask pattern of FIG. 6B, and then the recording medium is transported by 20.5 nozzles in the sub scanning direction. . Above, the process of step S1003 is complete | finished.

  In subsequent step S1004, recording is performed using all nozzles for the normal area. In this example, the normal area indicates an area in which recording can be performed in a state where the recording medium is sandwiched between two pairs of rollers, that is, the paper feed roller pair 105 and the conveyance roller 103 and the spur roller 104 pair.

  FIG. 24C shows the recording operation in step S1004. First, in the ninth scan, main scanning in the + X direction is performed by all the nozzles using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent tenth scan, the main scan in the −X direction is performed by all the nozzles using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 19.5 nozzles in the sub-scanning direction. In the eleventh scan, the main scanning in the + X direction is performed by all the nozzles using the mask pattern of FIG. Further, in the 12th scan, the main scan in the −X direction is performed by all the nozzles using the mask pattern of FIG. 6B, and then the recording medium is transported by 20.5 nozzles in the sub scan direction. Subsequent printing scans repeat the ninth to twelfth scans described above. When the recording progresses and the rear end of the recording medium approaches the process of removing from the paper feed roller, the process proceeds to step S1005.

  In step S1005, a recording operation for shifting from recording using all nozzles to recording using nozzles 31 to 60 for the rear end portion is performed. FIG. 24D shows the recording operation in step S1005. First, in the 12th scan, the main scan in the −X direction is performed by the nozzles 1 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10.5 nozzles in the sub-scanning direction. In the thirteenth scan, the main scanning in the + X direction is performed by the nozzles 11 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 10 nozzles in the sub-scanning direction. In the subsequent 14th scan, main scan in the −X direction is performed by the nozzles 11 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the 15th scan, the main scan in the + X direction is performed by the nozzles 21 to 60 using the mask pattern of FIG. No conveying operation is performed between 15 and 16 scans. Further, in the 16th scan, using the mask pattern of FIG. 6B, the main scan in the −X direction is performed by the nozzles 31 to 60, and then the recording medium is conveyed by 10.5 nozzles in the sub scan direction.

  In step S1006, a unique recording operation is performed at the timing when the recording medium is removed from the paper feed roller. FIG. 24E shows the recording operation in step S1006. First, in the 17th scan, main scan in the + X direction is performed by the nozzles 31 to 60 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 40 nozzles in the sub-scanning direction. In the subsequent 18th scan, main scanning in the −X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG.

  In this example, it is assumed that the recording medium comes off the paper feed roller 105 in the 18th scan. The transport amount at the moment when the recording medium passes through the paper feed roller tends to be larger than the set value because the recording medium is ejected from the paper feed roller. Therefore, as in this example, the influence of the transport error can be reduced by setting the transport amount at this timing to be larger than usual. Here, in the normal rear end printing, a printing operation for 40 nozzles is performed at the timing of carrying 10 nozzles, that is, between the first printing scan and the second printing scan. In order to align the data positions, the area of the used nozzles is shifted from 31 to 60 nozzles to 1 to 30 nozzles.

  After the 18th scan, the recording medium is transported by 9.5 nozzles in the sub-scanning direction. In the 19th scan, main scanning in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. No conveying operation is performed between the 19th and 20th scans.

  In the twentieth scan, the main scanning in the −X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scanning direction. Above, the process of step S1006 is complete | finished.

  In step S1007, a recording operation for returning the used nozzle position from the state of nozzles 1 to 30 to the nozzles 31 to 60 is performed. In step S <b> 1006, the used nozzle position is shifted from nozzle 1 to nozzle 30 in order to reduce the conveyance error at the moment when the recording medium is detached from the pair of paper feed rollers 105. However, as shown in FIG. 9C, the ink absorber of the recording apparatus of this example is opposed to the nozzle row located on the upstream side in the transport direction. Therefore, when recording the outermost portion in the marginless recording, it is necessary to perform the recording by the nozzle on the more upstream side.

  FIG. 24F shows the recording operation in step S1007. First, in the 21st scan, the main scan in the + X direction is performed by the nozzles 1 to 30 using the mask pattern of FIG. No conveying operation is performed between the 21st and 22nd scans. In the subsequent 22nd scan, main scan in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the 23rd scan, main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern shown in FIG. No conveying operation is performed between the 23rd and 24th scans. Further, in the 24th scan, the main scan in the −X direction is performed by the nozzles 11 to 40 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scan direction. In the 25th scan, main scanning in the + X direction is performed by the nozzles 11 to 40 using the mask pattern shown in FIG. No conveying operation is performed between the 25th and 26th scans. In the 26th scan, main scan in the −X direction is performed by the nozzles 21 to 50 using the mask pattern of FIG. Thereafter, the recording medium is conveyed by 9.5 nozzles in the sub-scanning direction. In the 27th scan, main scanning in the + X direction is performed by the nozzles 21 to 50 using the mask pattern of FIG. No conveying operation is performed between the 27th and 28th scans. Further, in the 28th scan, the main scan in the −X direction is performed by the nozzles 21 to 50 using the mask pattern of FIG. 6B, and then the recording medium is conveyed by 10.5 nozzles in the sub scan direction. In the 29th scan, the main scan in the + X direction is performed by the nozzles 21 to 50 using the mask pattern of FIG. No conveyance operation is performed between the 29th and 30th scans. In the 30th scan, main scan in the −X direction is performed by the nozzles 31 to 60 using the mask pattern of FIG. Thus, the recording operation in step S1007 is completed.

  In step S1008, the final recording is performed on the last end area of the recording medium. The recording operation here is equivalent to the recording operation in step S1002 described with reference to FIG.

  When the recording in the rear end area is completed, the process advances to step S1009 to discharge the recording medium. This is the end of the marginless recording operation for one page.

  In each of the recording processes in steps S1002 to S1008 described above, the conveyance amount of the recording medium, the number of nozzles used for recording, or the nozzle area are different from each other. However, in any process, the phase state in the unit region is unified to an equivalent state.

  FIG. 25 is a diagram schematically showing the phase state of the unit area and the landing state of the satellite when the interlaced recording of the present embodiment is performed. Here, in both areas 113 and 114, dots on which satellites are recorded on the right side of the main droplet and dots on which satellites are recorded on the left side of the main droplet are arranged alternately and evenly. In the interlaced recording of the present embodiment, the satellite recording state and phase state shown here can be obtained in any unit area in the recording operation of steps S1002 to S1008. Therefore, since the unit area having the same characteristic or area factor extends over the entire area of the page, the density unevenness as described in the problem section does not appear.

  In the above-described three embodiments, the interless recording method using two-pass multi-pass recording has been described. However, the present invention is not limited to such a configuration. Even without using multi-pass printing, interlaced printing for realizing an image with a resolution higher than the arrangement pitch of the nozzles can be executed. Even in this case, as shown in FIG. 15, various states are conceivable for the phase state (the order in which dots are recorded in each pixel in the area) in the unit area. Conversely, multi-pass printing of 3 or more passes can be used together.

  In the above description, the case of performing interlaced recording by bidirectional recording scanning has been described. However, the effect of the present invention can be sufficiently obtained even in unidirectional recording. The object of the present invention is to “equalize the phase state in the unit area” to mean “align the recording order of the dots recorded in the unit area in all the unit areas”. It does not limit direction. However, in bidirectional recording, since the recording position of the satellite already described affects the area factor of the unit area, it can be said that the effect is further exhibited by adopting the present invention in bidirectional recording.

  In the above-described embodiment, the case where an ink jet recording apparatus having an ink absorber disposed on the paper feed roller side is also used to perform marginless recording has been described. However, the present invention is limited to such a configuration. It is not something. The position where the ink absorber is provided is not limited to that shown in FIG. 9C. If the position or width is changed, the transport amount and the number of used nozzles in each embodiment are also changed. In any case, the present invention is effective as long as the conveyance amount, the position of the nozzle used, the mask pattern, and the like are set so that the phase state in the unit region is unified.

  Furthermore, the present invention is effective even when no marginless recording is performed. Regardless of the presence or absence of margins, a method that records images while varying the number of nozzles used for recording and the conveyance amount of the recording medium is used for the front and rear end areas of the recording medium, which tends to be unstable. Has been. For any purpose, the present invention can effectively function as long as it is a serial type ink jet recording apparatus that forms an image while controlling the number of nozzles used for recording and the transport amount within the same page.

  In the above embodiment, all the nozzles provided in the recording head are used to perform recording in the steady region. However, the effects of the present invention can be obtained without necessarily using all the nozzles. In other words, if the phase state can be adjusted by changing the area on the recording head used for recording the steady area and the area on the recording head used for recording other areas, the scope of the present invention. It can be said that it is included.

  In the above embodiment, for the sake of simplicity, description has been made using a recording head that discharges black ink, but of course, even if it is another ink color, or even when a plurality of ink colors are recorded simultaneously, Similar effects can be obtained.

  Further, as described with reference to FIG. 2, in the above three embodiments, the description has been given using the recording head having a configuration in which nozzles that discharge the same color are arranged in a line at a predetermined pitch. Even if the nozzle arrangement is not correct, the present invention functions effectively. For example, a recording head in which two nozzle rows arranged at a predetermined pitch are arranged in the main scanning direction and each nozzle row is shifted by a half pitch in the sub scanning direction may be used. In such a recording head, dots can be recorded at a pitch twice the predetermined pitch in the sub-scanning direction in one recording scan, and the recording resolution can be further increased by performing interlaced recording. I can do it.

It is a figure for demonstrating the main structures of the inkjet recording device applicable to this invention. FIG. 5 is a diagram illustrating a plurality of ejection openings arranged in a recording head applicable to the present invention from the Z direction. It is a schematic diagram for demonstrating the multipass recording method. It is a schematic diagram for demonstrating the multipass recording method. It is a schematic diagram for demonstrating the multipass recording method. (A) And (b) is a figure which shows the mask pattern applicable to 2-pass multipass printing. It is a schematic diagram for demonstrating the specific example of the interlace recording method. It is a flowchart for demonstrating the process of the operation | movement at the time of implement | achieving interlaced recording. (A)-(c) is sectional drawing of the recording part of the inkjet recording device in which recording without a margin is possible. (A)-(c) is sectional drawing for demonstrating the conveyance problem in the front-and-rear end part of a recording medium. 6 is a flowchart for explaining an operation process of the recording apparatus in realizing marginless recording. (A)-(d) is the schematic diagram which showed the mask pattern applied by 4-pass multipass printing. (A)-(f) is a schematic diagram for demonstrating the recording operation of each step in multipass recording. Various phase states that can be realized in a unit area of 2 pixels x 2 pixels were shown when performing the interless recording method that records dots with a resolution twice the nozzle pitch and 2-pass multi-pass printing simultaneously. FIG. FIG. 6 is a diagram showing various phases that can be realized in a unit area when performing interless recording in which dots are recorded at a resolution four times the nozzle pitch without using multi-pass recording. FIG. 5 is a schematic diagram for explaining a fixing state when two ink droplets are continuously recorded at adjacent positions. (A) And (b) is the figure which showed typically the main droplet of the ink recorded on a unit area | region and the landing state of a satellite at the time of performing interless recording by bidirectional | two-way recording scanning. It is the figure which showed the recording operation in the case of recording a regular area | region by the interlace recording method. It is a block diagram for demonstrating the structure of control of the inkjet recording device applied to embodiment of this invention. (A)-(f) is a schematic diagram for demonstrating the recording operation of each step of 1st Embodiment. FIG. 5 is a diagram schematically illustrating landing states of main ink droplets and satellites recorded in a unit area when interlaced recording is performed in the first embodiment. (A)-(c) is a schematic diagram for demonstrating the recording operation of each step of 2nd Embodiment. FIG. 10 is a diagram schematically showing a phase state of a unit area and a landing state of satellites in interlaced recording according to the second embodiment. (A)-(f) is a schematic diagram for demonstrating the recording operation of each step of 3rd Embodiment. It is the figure which showed typically the phase state of a unit area | region and the landing state of a satellite at the time of performing interless recording in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Ink cartridge 102 Recording head 103 Conveyance roller 104 Spur 105 Paper feed roller pair 106 Carriage 107 Ink absorber 108 Platen 111 Main droplet 112 Satellite 201 Nozzle 1300 CPU
1301 ROM
1302 RAM
1303 Image input unit 1304 Image signal processing unit 1305 Main bus line 1306 Operation unit 1307 Recovery system control circuit 1308 Recovery system motor 1309 Blade 1310 Cap 1311 Pump 1312 Diode sensor 1314 Head temperature control circuit 1315 Head drive control circuit 1316 Carriage drive control circuit 1317 Paper feed control circuit 1318 EEPROM

Claims (2)

Using a recording head in which a plurality of nozzles for ejecting ink are arranged in the sub-scanning direction at a pitch of 2 × d, ink is ejected from the nozzles while scanning the recording head in the main scanning direction intersecting the sub-scanning direction. By intermittently repeating a recording scan for recording dots on the recording medium and a sub-scan for conveying the recording medium in the sub-scanning direction, dots are arranged at a pitch of d in the sub-scanning direction of the recording medium. In an inkjet recording method for recording an image so as to
As the transport amount l of the sub-scan, l = 0, l = K × 2 × d , (K−1) × 2 × d <l <K × 2 × d , K × 2 × d <l <(K + 1) X 2 x d (K is a positive integer)
A recording operation step A for alternately executing a recording scan using M nozzles and a sub-scan for performing a transport operation of any one of the four transport amounts;
Printing scan using N (<M) nozzles in a fixed region among the plurality of arranged nozzles and sub-scanning for performing the transport operation of any of the four types of transport amounts are alternately executed. Recording operation step B;
Printing that alternately performs printing scanning using N (<M) nozzles in a non-fixed region among the plurality of arranged nozzles and sub-scanning that performs the conveyance operation of any of the four types of conveyance amounts. Operation process C;
Have
Dot recording for a plurality of pixels arranged in the main scanning direction of the recording medium is performed while complementing by a plurality of recording scans,
In the recording operation step A, l = K × 2 × d , (K−1) × 2 × d <l <K × 2 × d , and K × 2 × d <l <(K + 1) × 2 × d. Including at least sub-scanning for realizing a conveyance amount of
In the recording operation step B, l = K × 2 × d, (K−1) × 2 × d <l <K × 2 × d , and K × 2 × d <l <(K + 1) × 2 × d. The ratio of the number of times of sub-scanning including at least a sub-scan that realizes a carry amount of 1 and a carry amount of l = 0 is higher than that in the recording operation step A,
In the recording operation step C, transport amounts of l = K × 2 × d , (K−1) × 2 × d <l <K, and K × 2 × d <l <(K + 1) × 2 × d are set. An ink jet recording method characterized in that the ratio of the number of times of sub-scanning including at least sub-scanning to be realized and realizing a carry amount of l = 0 is higher than the ratio of the recording operation step B. Using a recording head in which a plurality of nozzles for ejecting ink are arranged in the sub-scanning direction at a pitch of 2 × d, ink is ejected from the nozzles while scanning the recording head in the main scanning direction intersecting the sub-scanning direction. By intermittently repeating a recording scan for recording dots on the recording medium and a sub-scan for conveying the recording medium in the sub-scanning direction, dots are arranged at a pitch of d in the sub-scanning direction of the recording medium. In an inkjet recording method for recording an image so as to
As the sub-scan transport amount l, l = 0, l = K × 2 × d , (K−1) × 2 × d <l <K × 2 × d , K × 2 × d <l <(K + 1) X 2 x d (K is a positive integer)
A recording operation step B in which a recording scan using N nozzles in a fixed region among the plurality of arranged nozzles and a sub-scan for performing the transport operation of any of the four types of transport amounts are alternately performed. When,
A printing operation step C for alternately executing printing scanning using N nozzles in a non-fixed region among the plurality of arranged nozzles and sub-scanning for carrying the carrying operation of any of the four kinds of carrying amounts; and ,
Have
Dot recording for a plurality of pixels arranged in the main scanning direction of the recording medium is performed while complementing by a plurality of recording scans,
In the recording operation step B, l = K × 2 × d, (K−1) × 2 × d <l <K × 2 × d , and K × 2 × d <l <(K + 1) × 2 × d. Including at least sub-scanning for realizing a conveyance amount of
In the recording operation step C, transport amounts of l = K × 2 × d , (K−1) × 2 × d <l <K, and K × 2 × d <l <(K + 1) × 2 × d are set. An ink jet recording method characterized in that the ratio of the number of times of sub-scanning including at least sub-scanning to be realized and realizing a carry amount of l = 0 is higher than the ratio of the recording operation step B.

Images