JP4262246B2 - Image recording apparatus and control method thereof - Google Patents

Description

  The present invention relates to an image recording apparatus, a control method therefor, and a storage medium, and more particularly to a uniform image recording method in an ink jet recording apparatus that performs recording by discharging ink onto a recording material.

  In printers, copiers, facsimiles, etc., recording devices used for recording images, etc., or recording devices used as print output devices such as composite electronic devices and workstations including computers and word processors, image information (character information, etc.) The image is recorded on a recording material (hereinafter also referred to as a recording medium) such as paper or a plastic thin plate based on (including all output information).

  Such a recording apparatus can be classified into an inkjet method, a wire dot method, a thermal method, a laser beam method, and the like depending on the recording method.

  Among these, an ink jet recording apparatus (hereinafter referred to as an ink jet printer) performs recording by ejecting ink onto a recording medium from a recording head or the like, and is easy to achieve higher definition than other recording methods. Moreover, it has various advantages such as high speed, excellent quietness, and low cost.

  On the other hand, in recent years, the importance of color output such as color images has increased, and many high-quality color inkjet printers comparable to silver salt photographs have been developed.

  In such an ink jet printer, in order to improve the recording speed, a recording head in which a plurality of recording elements are integrated and arranged (hereinafter also referred to as a multi-head) uses a plurality of ink discharge ports and a plurality of liquid paths integrated. In addition, a color display device having a plurality of the multi-heads is generally used for color correspondence.

  FIG. 1 shows a configuration of a main part of a general ink jet printer for performing recording on a paper surface using the multi-head.

  In FIG. 1, reference numeral 1101 denotes an ink jet cartridge. These are composed of an ink tank in which four color inks, that is, black, cyan, magenta, and yellow ink are stored, and a multi-head 1102 corresponding to each ink.

  FIG. 2 is a schematic view of a single color ejection port (hereinafter also referred to as a nozzle) disposed in the multi-head 1102 as viewed from the z direction in FIG.

  In FIG. 2, reference numeral 1201 denotes D nozzles arranged at a D nozzle density (Ddpi) per inch on the multi-head 1102. The nozzles arranged in d are referred to as even nozzles in the y direction, and the odd nozzles are referred to as odd nozzles.

  In FIG. 1, reference numeral 1103 denotes a paper feed roller, which rotates in the direction of the arrow in the figure while holding the recording medium P together with the auxiliary roller 1104, and rotates the recording medium P in the y direction (sub-scanning direction, transport direction, paper feed direction). Transport from time to time.

  Reference numeral 1105 denotes a pair of paper feed rollers for feeding a recording medium. Like the rollers 1103 and 1104, the pair of rollers 1105 rotate while holding the recording medium P. However, it is possible to apply tension to the recording medium by making the rotation speed lower than that of the paper feed roller 1103.

  Reference numeral 1106 denotes a carriage that supports the four inkjet cartridges 1101 and scans them together with recording. The carriage 1106 waits at the home position h at the position indicated by the broken line in the drawing when recording is not performed or when the recovery processing of the multi-head 1102 is performed.

  The carriage 1106 at the home position h before the start of recording moves in the x direction (main scanning direction) when there is a recording start command, and D nozzles arranged at a density of D per inch of the multihead 1102. In step 1201, recording with a width of D / D inches is performed on the paper surface. Before the second recording starts after the end of the first recording, the paper feeding roller 1103 rotates in the direction of the arrow to feed the paper in the y direction by a width D / D inch.

  In this way, by repeating the recording of the width D / D inch (recording 1 inch width of the recording medium using D nozzles) and the paper feeding by the multi-head 1102 for each main scanning of the carriage 1106, for example, A page of records can be completed. Hereinafter, such a recording mode is referred to as a one-pass recording mode.

  As another recording mode, the carriage 1106 at the home position h before the start of recording moves in the x direction (for example, the main scanning forward direction) and moves 1 inch of the multi-head 1102 when a recording start command is issued. Recording with a width of D / D inches is performed on the paper surface by D nozzles 1201 arranged at a density of D per hit.

  The dots to be recorded by scanning at this time are obtained by thinning out the prescribed image data by about half in a predetermined pattern. The paper feed roller 1103 rotates in the direction of the arrow after the end of the first recording and before the second recording starts to feed the paper in the y direction by width D / 2D inches.

  In the second scan, the carriage 1106 scans in the opposite direction to the first print (for example, in the reverse direction of the main scan), and prints according to the respective patterns, so that the areas corresponding to the respective nozzles are recorded. Complete the record. Such a recording mode is called a two-pass recording mode. Hereinafter, the M (≧ 2) pass recording is generally referred to as a multi-pass recording mode.

  In such a multi-pass recording mode, it is optimal when recording a photographic image with high image quality as a color printer.

  However, there is a case where a uniform image cannot be obtained due to the ejection direction of the ink droplets ejected from the nozzle or the ink droplets (referred to as satellites) smaller than the main droplets separated from the main droplets during ejection. .

  In particular, if the ejection direction of the d nozzles of the Even nozzle and the Odd nozzle are different in the main scanning direction, the landing position of the satellite on the paper surface may be different and a uniform image may not be obtained.

  Hereinafter, a case where a uniform image cannot be obtained due to different ejection directions and satellites of the Even nozzle and the Odd nozzle will be described in detail with reference to the drawings.

  FIGS. 3A to 3C are views showing landing positions on the paper surface, which is a recording medium for main droplets and satellites, in the ink droplet ejection direction.

  FIG. 3A is a schematic diagram showing the landing positions of the main droplet and the satellite when the ink droplet ejection direction is perpendicular to the paper surface.

  FIG. 3B is a schematic diagram showing the landing positions of the main droplet and the satellite when the ink droplet discharge direction is inclined in the carriage traveling direction.

  FIG. 3C is a schematic diagram showing the landing positions of the main droplet and the satellite when the ink droplet ejection direction is inclined opposite to the carriage traveling direction.

  3A to 3C, reference numeral 1301 denotes a main droplet, 1302 denotes a satellite, 1303 denotes a carriage traveling direction, and 1304 denotes a discharge inclination direction.

  First, referring to FIG. 3A, the landing positions of the main droplet and the satellite when the ink droplet ejection direction is perpendicular to the paper surface as the recording medium, that is, when the ink droplet ejection direction is not inclined in the carriage traveling direction. Will be described.

  In FIG. 3A, when the discharge speeds of the main droplets 1301 and satellites 1302 discharged from the nozzles are compared, the discharge speed of the main droplets 1301 is usually higher than the discharge speed of the satellites 1302. Therefore, the satellite 1302 has a longer time than the main droplet 1301 to the time required from ink ejection to landing on the recording medium. Therefore, since the satellite 1302 is landed after the main droplet 1301 has landed on the paper surface as a recording medium, a predetermined time is required from when the main droplet 1301 has landed until the satellite 1302 landed.

  Here, since the ejection of the main droplet 1301 and the satellite 1302 is performed while the carriage 1106 is moving, the carriage speed in the carriage traveling direction is added to the ejection speed of the main droplet 1301 and the satellite 1302.

  For this reason, the landing point of the main droplet 1301 and the landing point of the satellite 1302 on the paper surface as a recording medium are different positions. That is, the satellite 1302 is landed in the traveling direction of the carriage 1106 with respect to the landing position of the main droplet 1301 shown in FIG.

  Next, the landing positions of the main droplet and the satellite when the ink droplet discharge direction is inclined in the carriage traveling direction 1303 with respect to the paper surface as the recording medium will be described with reference to FIG.

  In FIG. 3B, the ink droplet ejection direction is inclined in the carriage traveling direction 1303. For this reason, the speed of the satellite 1302 in the carriage traveling direction 1303 is larger than the speed when the ink droplet ejection direction is perpendicular to the paper surface (FIG. 3A), so the landing point of the satellite 1302 is as shown in FIG. ) Is landed at a position shown in the figure further away from the main droplet 1301 than the landing point of the satellite 1302 shown in FIG.

  Next, with reference to FIG. 3C, the landing positions of the main droplet and the satellite when the ink droplet discharge direction is inclined in the direction opposite to the carriage traveling direction 1303 with respect to the paper surface as the recording medium will be described. To do.

  In FIG. 3C, the ink droplet ejection direction is inclined in the direction opposite to the carriage traveling direction 1303. Therefore, since the speed of the satellite 1302 in the carriage traveling direction is smaller than the speed when the ink droplet ejection direction is perpendicular to the paper surface (FIG. 3A), the landing point of the satellite 1302 is as shown in FIG. The landing is made at a position closer to the main droplet 1301 than the landing point of the satellite 1302 shown in FIG. As an example, FIG. 3C shows a case where the satellite 1302 has landed at substantially the same position as the main droplet 1301.

  Next, with reference to FIGS. 4 (a) to 4 (d) and FIGS. 5 (a) to 5 (d), the problem of the recording image quality in the multi-pass recording mode performed by the conventional ink jet printer will be described. .

  4 (a) to 4 (d) and FIGS. 5 (a) to 5 (d), the Even nozzle is inclined in the ink droplet ejection direction in the main scanning direction, and the Odd nozzle is opposite to the main scanning direction. Although the case where the ink droplet ejection direction is inclined in the direction will be described, the same applies even if the inclination directions are opposite directions.

  First, FIGS. 4A to 4D will be described.

  4 (a) to 4 (d) are multi-pass recording modes in which recording is performed in 4 passes, and 1 / D inch square is a unit recording pixel (area surrounded by a dotted line), and 4 dots are recorded in the unit recording pixel. FIG. 4 is a schematic diagram when the recording medium is fed by an even multiple of 1 / D inch, and there are four patterns described below.

  FIG. 4A is a schematic diagram showing a dot arrangement when the first pass printing is started by the Even nozzle while the carriage is traveling in the main scanning direction (x).

  FIG. 4B is a schematic diagram showing a dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the main scanning direction (x).

  FIG. 4C is a schematic diagram showing the dot arrangement when the first pass printing is started by the Even nozzle while the carriage is moving in the direction opposite to the main scanning direction (x).

  FIG. 4D is a schematic diagram showing the dot arrangement when the first pass printing is started by the odd nozzle while the carriage is moving in the direction opposite to the main scanning direction (x).

  In FIGS. 4A to 4D, 401 is a recording dot for the first pass, 402 is a recording dot for the second pass, 403 is a recording dot for the third pass, and 404 is a recording dot for the fourth pass. Show. Actually, the four types of recording dots in the first to fourth passes are recorded overlappingly, and in the case of FIGS. 4A to 4D, one main droplet and one satellite are formed. These represent the gradation of the unit recording pixel. However, in the following description, the above expression is used for simple explanation. 4A to 4D appear on the recording medium as follows. That is, FIG. 4A and FIG. 4B (or FIG. 4C and FIG. 4D) appear alternately every 1 / D inch in the paper feed direction.

  4 (a) to 4 (d), arrows (←, →) described in the unit recording pixels indicate the traveling direction of the carriage in each pass recording, and E is a dot recorded by the Even nozzle, O indicates a dot recorded by the Odd nozzle. Next, the problem of the recording image quality in the conventional multi-pass recording mode will be described in detail with reference to FIGS. 4 (a) to 4 (d) described above.

  First, the pattern of FIG. 4A will be described.

  In FIG. 4A, in the first pass, recording is performed by the Even nozzle while the carriage is moving in the main scanning direction (x), so that the main droplet 301 and the satellite 302 land at separate positions.

  Next, since the second pass is performed after the paper feed of an even multiple of 1 / D inch, recording is performed with the Even nozzle as well. Further, since recording is performed while the carriage 106 is moving in the direction opposite to the x direction, the main droplet 301 and the satellite 302 land at close positions. Next, in the third pass and the fourth pass, the same recording as in the first pass and the second pass described above is performed, so that the recording is performed with the dot arrangement as shown in FIG.

  That is, as shown in FIG. 4A, when the first pass printing is started with the Even nozzle while the carriage 106 is traveling in the main scanning direction (x), all dots within the unit recording pixel are the Even nozzle. To be recorded.

  Next, the pattern in FIG. 4B will be described.

  In FIG. 4B, since the recording is performed by the odd nozzle while the carriage is moving in the direction opposite to the main scanning direction (x) in the first pass, the main droplet 301 and the satellite 302 land at separate positions.

  Next, since the second pass is performed after the paper feed of an even multiple of 1 / D inch, recording is also performed by the odd nozzle. Further, since the recording is performed while the carriage 106 is moving in the x direction, the main droplet 301 and the satellite 302 land on close positions.

  Next, in the third pass and the fourth pass, the same recording as in the first pass and the second pass described above is performed, so that the recording is performed with the dot arrangement as shown in FIG.

  That is, as shown in FIG. 4B, when the first pass printing is started by the odd nozzle while the carriage 106 is traveling in the direction opposite to the main scanning direction (x), all the dots are within the unit recording pixel. Recording is performed with an odd nozzle.

  Similarly, also in the case of FIGS. 4C and 4D, all dots are recorded by only one of the even and odd nozzles in the unit recording pixel.

  As shown in FIGS. 4A to 4D, when all the recording pixels are recorded by the odd nozzle or the even nozzle, the ejection characteristics such as different ink ejection amounts may be different between the odd nozzle and the even nozzle. In some pixels, a recorded ink amount is large, and in a certain pixel, a visually non-uniform image such as a small amount of recorded ink is recorded.

  Further, FIGS. 4A and 4B (or FIGS. 4C and 4D) alternately appear every 1 / D inch with respect to the paper feed direction. That is, the landing positions of the satellites 1302 appear alternately on the left and right with respect to the main droplet 1301 every 1 / D inch. In other words, a pixel in which a satellite appears on the right side of the main droplet (pixel in FIG. 4A) and a pixel in which a satellite appears on the left side of the main droplet (pixel in FIG. 4B) are 1 / It appears alternately every D inches. For this reason, a visually non-uniform image is recorded.

  Next, FIGS. 5A to 5D will be described.

  FIGS. 5A to 5D are multi-pass recording modes in which recording is performed in four passes, and 1 / D inch square is a unit recording pixel, and four dots are recorded in a unit recording pixel (area surrounded by a dotted line). FIGS. 5A and 5B are schematic diagrams in the case where the paper feeding of the recording medium is performed at an odd multiple of 1 / D inch, and there are four patterns shown in FIGS. 5A to 5D described below. In FIG. 5, as in FIG. 4 described above, in order to make the explanation easier to understand, 4 dots are illustrated as if they landed at different positions of the single recording pixel. Four dots land on almost the same point in the unit recording pixel. The appearance of FIGS. 5A to 5D is the same as that in FIG. 4, and FIGS. 5A and 5B (or FIGS. 5C and 5D). ) Appear alternately every 1 / D inch in the paper feed direction.

  FIG. 5A is a schematic diagram showing a dot arrangement when the first pass printing is started by the Even nozzle while the carriage is traveling in the x direction.

  FIG. 5B is a schematic diagram showing a dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the x direction.

  FIG. 5C is a schematic diagram showing the dot arrangement when the first pass printing is started by the Even nozzle while the carriage is moving in the direction opposite to the x direction.

  FIG. 5D is a schematic diagram showing a dot arrangement when the first pass printing is started by the odd nozzle while the carriage is moving in the direction opposite to the x direction.

  In FIGS. 5A to 5D, 401 is the first-pass recording dot, 402 is the second-pass recording dot, 403 is the third-pass recording dot, and 404 is the fourth-pass recording dot. The arrows (←, →) described in the unit recording pixels indicate the traveling direction of the carriage in each pass recording, E indicates a dot recorded by the Even nozzle, and O indicates a dot recorded by the Odd nozzle. ing. The description of each of the above symbols is the same as that in FIGS. 4A to 4D, and the description thereof is omitted because it is duplicated. In addition, the inclination direction of ejection of the Odd nozzle and the Even nozzle is the same as that shown in FIGS. 4A to 4D as described above.

  Next, the problem of the recording image quality in the conventional multi-pass recording mode will be described in detail with reference to FIGS. 5 (a) to 5 (d) described above.

  First, the pattern of FIG. 5A will be described.

  In FIG. 5A, since the recording is performed by the Even nozzle while the carriage is moving in the main scanning direction (x) in the first pass, the main droplet 301 and the satellite 302 land at separate positions.

  Next, in the second pass, after odd number times of 1 / D inch is fed, recording is performed by the odd nozzle. Further, since the recording is performed while the carriage is moving in the direction opposite to the x direction, the main droplet 301 and the satellite 302 land at positions separated from each other.

  Next, in the third pass and the fourth pass, the same recording as in the first pass and the second pass described above is performed, so that the recording is performed with the dot arrangement as shown in FIG.

  That is, as shown in FIG. 5A, when the first pass printing is started by the Even nozzle while the carriage 106 is traveling in the main scanning direction (x), all the dots in the unit recording pixel are the Odd nozzle. Alternatively, recording is performed by alternately using the Even nozzle.

  Next, the pattern in FIG. 5B will be described.

  In FIG. 5B, since the recording is performed by the odd nozzle while the carriage is moving in the main scanning direction (x) in the first pass, the main droplet 301 and the satellite 302 land at close positions.

  Next, in the second pass, the paper is fed by an odd multiple of 1 / D inch, and then recording is performed by the Even nozzle. Further, since the recording is performed while the carriage 106 is moving in the direction opposite to the x direction, the main droplet 301 and the satellite 302 land at close positions.

  Next, in the third pass and the fourth pass, the same recording as in the first pass and the second pass described above is performed, so that the recording is performed with the dot arrangement as shown in FIG.

  That is, as shown in FIG. 5B, when the first pass printing is started with the Odd nozzle while the carriage 106 is traveling in the main scanning direction (x), all the dots within the unit printing pixel are Odd. Recording is performed by alternately using nozzles or even nozzles.

  In the case of FIGS. 5C and 5D, although not described, all the dots in the unit recording pixel are Odd nozzles as in FIGS. 5A and 5B described above. Alternatively, recording is performed by alternately using the Even nozzle.

  That is, as shown in FIGS. 5 (a) to 5 (b), all unit recording pixels are recorded only by the odd nozzle or even nozzle by performing recording with a paper feed of an odd multiple of 1 / D inch. Will disappear.

  However, FIG. 5A and FIG. 5B (or FIG. 5C and FIG. 5D) appear alternately every 1 / D inch in the paper feed direction. That is, the landing positions of the satellites 302 appear alternately on the left and right with respect to the main droplet 301 every 1 / D inch in the paper feeding direction. In other words, the pixels in which satellites appear on both the left and right sides of the main droplet (pixels in FIG. 5A) and the pixels in which no satellites appear (pixels in FIG. 5B) are each 1 / D inch in the paper feed direction. It appears alternately. For this reason, a visually non-uniform image is recorded.

  As described above, in a conventional inkjet printer that repeatedly scans the recording head in the main scanning direction and the recording medium in the sub-scanning direction to form an image by multi-pass (two or more passes) recording, the nozzle interval is 1 / D inch. If the Odd nozzle and the Even nozzle have different ejection characteristics, a visually non-uniform image will be recorded if the paper feed is repeated at an even multiple or an odd multiple of 1 / D inch. There was a case.

  The present invention has been made to solve the above-described problems of the prior art, and its purpose is to avoid visually non-uniform image recording in multi-pass recording of two or more passes, and to achieve uniformity. It is an object to provide an image recording apparatus capable of performing good image recording and a control method thereof.

In order to achieve the above object, an image recording apparatus according to an embodiment of the present invention has the following arrangement. That is, a recording head in which a plurality of nozzles for ejecting ink droplets of the same color are arranged at a predetermined interval is scanned in a first direction intersecting with the nozzle arrangement direction and in a second direction opposite to the first direction . In order to perform recording on the pixel region by ejecting ink droplets from different nozzles to the pixel region of the recording medium in a plurality of scans including the scanning in the first direction and the scanning in the second direction. an image recording device, in an even multiple of the conveying amount by the conveying said plurality of scans of the conveyance of an odd multiple of the conveying quantity of the recording medium is interposed at least once in the interval of the recording medium of the distance When a plurality of predetermined number of ink droplets are ejected toward each of the plurality of pixel regions arranged along the transport direction of the recording medium, the main droplets of the predetermined number of ink droplets overlap each other. Satellite of the predetermined number of ink drops in the scanning direction on both sides, characterized in that the lands of.

Here, for example, the length of the pixel region in the transport direction is preferably substantially equal to the interval .

Here, for example, conveyed by the conveying and transporting of the odd multiple by conveying amount of said even multiple is is preferably performed alternately.

Here, for example, the plurality of nozzles arranged at the predetermined interval includes a nozzle constituting the first nozzle row and a nozzle constituting the second nozzle row, and satellites of ink droplets ejected from the first nozzle row. Is landed at a position shifted in the one direction with respect to the position where the main droplet overlaps, and the satellite of the ink droplet ejected from the second nozzle row is in the two directions with respect to the position where the main droplet overlaps. It is preferable to land at a shifted position .

The image recording method of the present invention has the following configuration. Scanning a recording head in which a plurality of nozzles for ejecting ink droplets of the same color are arranged at a predetermined interval in a first direction intersecting the nozzle arrangement direction and a second direction opposite to the first direction; An image for recording on the pixel area by ejecting ink droplets from different nozzles to the pixel area of the recording medium in a plurality of scans including scanning in the first direction and scanning in the second direction. In the recording method, between the scanning in the first direction and the scanning in the second direction, the recording medium is transported by a transport amount that is an even multiple of the interval and the recording is performed by a transport amount that is an odd multiple of the interval. In the plurality of scans including the step of alternately transporting the medium, the transport of the recording medium by the transport amount of the even number times, and the transport of the recording medium by the transport amount of the odd number times, toward the pixel region The record A step of ejecting ink droplets from the print head, and a plurality of predetermined number of ink droplets are ejected by the plurality of scans toward each of the plurality of pixel regions arranged along the conveyance direction of the recording medium. In this case, the satellites of the predetermined number of ink droplets land at positions shifted in the first direction and positions shifted in the second direction with respect to a position where the main droplets of the predetermined number of ink droplets overlap. And

  According to the present invention, there is provided an image recording apparatus capable of performing recording of uniform and good images while avoiding visually non-uniform image recording in multi-pass recording of two or more passes, and a control method thereof. can do.

  An embodiment according to the present invention will be described below with reference to the drawings.

  However, in this embodiment, a serial ink jet printer is used as an image recording apparatus, but the scope of the present invention is not limited to the description example.

[First Embodiment]
[Control configuration]
FIG. 6 is a block diagram showing a control configuration of the ink jet printer according to the first embodiment of the present invention. The mechanical configuration of the ink jet printer according to the present embodiment is the same as the general configuration shown in FIG.

  In FIG. 6, a CPU 600 executes control and data processing of each unit to be described later via a main bus line 605. That is, the CPU 600 controls the head drive control, carriage drive control, and data processing described in FIG. 7 and subsequent sections through the respective units described below in accordance with a program stored in the ROM 601.

  The RAM 602 is used as a work area for data processing by the CPU 600, and other memory includes a hard disk.

  The image input unit 603 has an interface with a host device (not shown), and temporarily holds an image input from the host device (not shown). The image signal processing unit 604 performs data processing in addition to color conversion and binarization.

  The operation unit 606 includes keys and the like, thereby enabling control input by the operator. The recovery system control circuit 607 controls a recovery operation such as preliminary ejection in accordance with a recovery processing program stored in the RAM 602. That is, the recovery system motor 608 drives the recording head 613 and the cleaning blade 609, the cap 610, and the suction pump 611 that face and separate from the recording head 613.

  The head drive control circuit 615 controls the drive of the ink ejection electrothermal transducer of the recording head 613 and normally causes the recording head 613 to perform ink ejection for preliminary ejection or recording. Further, the carriage drive control circuit 616 and the paper feed control circuit 617 similarly control carriage movement and paper feed, respectively, according to the program.

  In addition, a heat retention heater is provided on the substrate on which the electrothermal transducer for ink ejection of the recording head 613 is provided, and the ink temperature in the recording head can be adjusted by heating to a desired set temperature. The thermistor 612 is also provided on the substrate in the same manner, and is used for measuring a substantial ink temperature inside the recording head. Similarly, the thermistor 612 may be provided not on the substrate but on the outside or in the vicinity of the periphery of the recording head.

[Recording head]
Next, a recording head according to an embodiment of the present invention will be described with reference to a schematic diagram shown in FIG.

  In FIG. 7, reference numeral 701 denotes a black ink recording head, reference numeral 702 denotes a cyan ink recording head, reference numeral 703 denotes a magenta ink recording head, and reference numeral 704 denotes a yellow ink recording head. Each of the four color recording heads includes an even nozzle row 701a and an odd nozzle row 701b. The recording head described above is an example, and other configurations may be used.

  Here, the black Odd nozzle row 701a and the Even nozzle row 701b are arranged at a density (300 dpi) of D = 300 per inch, and the interval (nozzle pitch) P between the nozzles is P = 1. / D = 1/300 inch≈84.7 μm.

  That is, d = 32 ejection ports (32 nozzles), and the recording head length (d / D) is d / D = 32/300 inches≈2.71 mm. Further, as shown in the drawing, the black Odd nozzle row 701a and the Even nozzle row 701b are shifted by P / 2, that is, 1/600 inch in the paper feeding direction (conveying direction).

  Accordingly, the substantially black nozzle row 701 has 64 nozzles arranged at a density (600 dpi) of D = 600 nozzles per inch.

  The three color ink recording heads, that is, the cyan ink recording head 702, the magenta ink recording head 703, and the yellow ink recording head 704 are also the same as the black ink recording head 701 described above.

  The positional relationship between the black Odd nozzle row and the three color nozzles is arranged side by side in the main scanning (x) direction as shown in the figure.

  On the other hand, the resolution of one pulse of the motor that drives the paper feed roller for transporting the recording medium is 600 dots per inch (600 dpi) in terms of the transport amount.

  For example, in order to perform the 1-pass printing mode with a black nozzle array of 600 dpi and 64 nozzles (about 2.71 mm), the recording medium may be conveyed in the conveying direction (sub-scanning direction) by a recording width of 2.71 mm.

  The black nozzle row 701 described above is merely an example, and may be arranged at a density of D per inch (Ddpi) and a nozzle pitch P (P = 1 / D). In this case, the resolution of one pulse of the motor that drives the paper feed roller for conveying the recording medium may be D dots per inch (Ddpi) or a multiple thereof in terms of the conveyance amount.

[Multipass recording mode]
Next, a multi-pass printing mode using the ink jet printer having the control configuration described above and a print head will be described.

  In the following description, as an example of a multi-pass printing mode in which a color nozzle array is divided into m and an image is completed by m scans, four passes are performed with m = 4 and images are completed by four scans. This will be described using the recording mode. Note that the description using the 4-pass printing mode is an example, and the present embodiment can be applied to two or more multi-pass printing modes.

  In this embodiment, for example, in the 4-pass multi-pass printing mode using the color recording heads shown in FIG. 8, the repetitive carry amount (paper feed amount) in the print medium carrying direction is set to 16 in the first pass. / 600 inch, 15/600 inch in the second pass, 16/600 inch in the third pass, and 15/600 inch in the fourth pass. This is repeated, that is, an even multiple of 1/600 inch (1 By repeating the recording medium conveyance direction by repeating the second pass), the odd multiple (second pass), the even multiple (third pass), and the odd multiple (fourth pass) without being affected by the satellite landing position. A uniform image can be recorded.

  Therefore, in the color 4-pass multi-pass printing mode according to the present embodiment, the unit printing pixel is completed with the paper feed amount of 62/600 dpi which is the total of the four paper feed amounts. Therefore, the nozzles indicated by 63 and 64 in FIG. 8 are not used, and only 62 nozzles 1 to 62 are used to record an image.

  Next, the image recording method of this embodiment in the color 4-pass multi-pass recording mode will be described with reference to FIGS. 9A to 9D, FIGS. 10A and 10B.

  9 (a) to 9 (d) are multi-pass recording modes in which recording is performed in four passes, where 1/600 inch square is a unit recording pixel, 4 dots are recorded in the unit recording pixel, and paper feed is 1/600 inch. It is a schematic diagram showing the dot arrangement in the case of repeating by even and odd multiples.

  FIG. 9A is a schematic diagram showing a dot arrangement when the first pass printing is started by the Even nozzle while the carriage is traveling in the main scanning (x) direction.

  FIG. 9B is a schematic diagram showing the dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the main scanning (x) direction.

  FIG. 9C is a schematic diagram showing the dot arrangement when the first pass printing is started by the even nozzle while the carriage is traveling in the direction opposite to the main scanning (x) direction.

  FIG. 9D is a schematic diagram showing a dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the direction opposite to the main scanning (x) direction.

  In FIGS. 9A to 9D, 101 is a first-pass recording dot, 102 is a second-pass recording dot, 103 is a third-pass recording dot, and 104 is a fourth-pass recording dot. Show. Actually, the four types of recording dots in the first to fourth passes are combined and one main droplet and two satellites are formed in the case of FIGS. 9 (a) to 9 (d). These represent the gradation of the unit recording pixel. However, in the following description, the above expression is used for simple explanation. 9A to 9D appear on the recording medium as follows. That is, FIG. 9A and FIG. 9B (or FIG. 9C and FIG. 9D) appear alternately every 1 / D inch in the paper feed direction.

  In FIGS. 9A to 9D, arrows (←, →) described in the unit recording pixels indicate the traveling direction of the carriage in each pass recording, and E is a dot recorded by the Even nozzle, O indicates a dot recorded by the Odd nozzle. Also, the inclination of the ink droplet ejection direction of the Odd nozzle and the Even nozzle is a diagram when the Even nozzle is inclined in the main scanning (x) direction and the Odd nozzle is inclined in the opposite direction.

  Next, with reference to FIGS. 9A to 9D and FIGS. 10A to 10D described above, the image recording in the multi-pass recording mode (4 passes) will be described in detail.

  First, FIG. 9A will be described.

  In FIG. 9A, in the first pass, recording is performed using an arbitrary Even nozzle while the carriage is moving in the x direction, so that the main droplet and the satellite land at separate positions. When the first pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10A, recording of unit recording pixels in the first pass is performed using, for example, the Even nozzle 2, and after the first pass recording is finished, 16/600 inch paper feeding is performed.

  Next, in the second pass, since recording is performed using an arbitrary Odd nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, the main droplet and the satellite are separated from each other (however, in the first pass, Land in the opposite direction). When the second pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, the same unit recording pixel in the second pass is recorded using the Odd nozzle 17, and after the second pass recording is completed, the paper feed of 15/600 inches is performed.

  Next, in the third pass, since recording is performed using an arbitrary Odd nozzle while the carriage is moving in the x direction, the main droplet and the satellite land at close positions. When the third pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10A, the same unit recording pixel in the third pass is recorded using the odd nozzle 33, and after the third pass recording is completed, the paper feed of 16/600 inches is performed.

  Next, in the fourth pass, recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, so that the main droplet and satellite land at close positions. When the fourth pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, recording of the same unit recording pixel in the fourth pass is performed using the Even nozzle 50, and after the recording of the fourth pass is completed, 15/600 inch paper feed is then performed.

  When the above-described four-pass image recording is performed, as shown in FIG. 9A, recording is performed by one satellite equally on the left and right of the pixels recorded by the main droplet.

  Next, FIG. 9B will be described.

  Next, in FIG. 9B, in the first pass, recording is performed using an arbitrary Odd nozzle while the carriage is moving in the x direction, so the main droplet and satellite land at close positions. When the first pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10B, the unit recording pixels in the first pass are recorded using, for example, the Odd nozzle 1, and after the first pass recording is finished, the paper is then fed by 16/600 inches.

  Next, in the second pass, since recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, it lands at a position close to the main droplet and the satellite. When the second pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, the same unit recording pixel in the second pass is recorded using the Even nozzle 18, and after the second pass recording is completed, the paper feed of 15/600 inches is performed.

  Next, in the third pass, since recording is performed using an arbitrary Even nozzle while the carriage is moving in the x direction, the main droplet and the satellite land at a distant position. When the third pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10A, the recording of the same unit recording pixel in the third pass is performed using the Even nozzle 34, and after the third pass recording is finished, the paper is fed by 16/600 inches.

  Next, in the fourth pass, since recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, the main droplet and the satellite are separated from each other (however, in the third pass, Land in the opposite direction). When the fourth pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, recording of the same unit recording pixel in the fourth pass is performed using the odd nozzle 49, and after the recording of the fourth pass is completed, 15/600 inch paper feeding is performed.

  When the above-described four-pass image recording is performed, as shown in FIG. 9B, recording is performed with one satellite equally on the left and right of the pixels recorded by the main droplet.

  9 (c) and 9 (d) differ from FIGS. 9 (a) and 9 (b) described above only in that the traveling direction of the carriage in each pass is opposite. 9 (c) or FIG. 9 (d) is the same in that the recording by one satellite is equally performed on the left and right of the pixels recorded by the main droplet, and detailed description thereof will be given here. Is omitted.

  In this way, the EVEN and ODD nozzles are recorded by repeating the conveyance of odd-numbered times of paper and the even-numbered times of paper conveyance sequentially and recording 600 inch unit recording pixels in four passes (4-dot recording). Pixels (pixels shown in FIGS. 9 (a) to 9 (d)) in which the satellites discharged from each appear on the left and right of the main droplet can be recorded. 9A to 9D, in any case, an equal number of satellites appear on both the left and right sides of the main droplet, so that a uniform image is obtained. That is, in the first embodiment, FIG. 9A and FIG. 9B (or FIG. 9C and FIG. 9D) appear alternately every 1 / D inch in the paper feed direction. Therefore, in detail, a pixel in which one satellite appears on both the left and right sides of the main droplet (pixel in FIG. 9A) and a pixel in which one satellite appears on both the left and right sides of the main droplet (FIG. 9 ( Since the pixels b) appear alternately every 1 / D inch in the paper feed direction, satellites can appear uniformly for all the pixels, and the conventional problems in FIGS. 4 and 5 are eliminated. be able to.

  In the above description, four-pass printing has been described as an example, but the above description can be applied to multi-pass printing with two or more passes. In the above description, the Even and Odd nozzles of the recording heads of the respective inks are arranged in different nozzle rows, but the arrangement of the recording heads is an arrangement other than the above example, for example, the Even and Odd nozzles are arranged in the same row. A single-row recording head may be used.

  When the nozzle array of the recording head is arranged with a density of D per inch (Ddpi) and a nozzle pitch P (P = 1 / D), a paper feed roller for conveying the recording medium is provided. The resolution of one pulse of the motor to be driven may be D dots per inch (Ddpi) or a multiple thereof in terms of the transport amount.

  As described above, in the inkjet printer of this embodiment, in multi-pass printing of two or more passes (four passes in the above-described example), the paper feed of the recording medium is 1 / D (1/600 inch in the above-described example). If the operation is repeated at even multiples and odd multiples, the dots ejected from the Even and Odd nozzles are evenly recorded on all unit recording pixels, and the satellites are evenly recorded on the left and right of the main droplets. ) Therefore, non-uniform image recording can be avoided and good image recording can be performed.

[Second Embodiment]
Next, an ink jet printer according to a second embodiment will be described.

  The mechanical configuration, control configuration, and recording head of the ink jet printer of the second embodiment are the same as those of the ink jet printer described in the first embodiment (FIG. 1), control configuration (FIG. 6), and recording head ( The thing of the same structure as FIG. 7, 8) can be used. Accordingly, the description of the mechanical configuration, the control configuration, and the recording head of the ink jet printer according to the second embodiment will be omitted, and the description thereof will be omitted in the following description.

[Multipass recording mode]
Next, a multi-pass recording mode using the above-described ink jet printer and recording head will be described.

  In the following description, as an example of a multi-pass printing mode (m is 2 or more) in which a color nozzle row is divided into m and an image is completed by m scans, m = 4 is divided into four and four scans are performed. A description will be given using a four-pass recording mode for completing an image.

  First, features of the second embodiment will be described.

  In the first embodiment, in the 4-pass multi-pass recording mode, the present invention is applied to the case where the four paper feed amounts of the recording medium are alternately conveyed by even / odd paper feed amounts of 1 / D inch. In the second embodiment, in the four-pass multi-pass recording mode, the four sheet feeding amounts of the recording medium are alternately conveyed by odd / even sheet feeding amounts of 1 / D inch. The case where this invention is applied is demonstrated about the case where it is not carried out.

  Specifically, for example, as shown in FIG. 11, the first transport amount 15/600 inches, the second transport amount 15/600 inches, the third transport amount 16/600 inches, the fourth transport amount A case where the transport amount is 16/600 inches will be described as an example.

  That is, in the second embodiment, in the 4-pass multi-pass printing mode using the color recording heads shown in FIG. 11, the repetitive carry amount (paper feed amount) in the print medium carrying direction is set to the first pass. 15/600 inch in the second pass, 15/600 inch in the second pass, 16/600 inch in the third pass, and 16/600 inch in the fourth pass. This repetition, that is, 1 / D = 1/600 Satellite landing is achieved by repeating the recording medium in the conveyance direction by repeating odd multiples (first pass), odd multiples (second pass), even multiples (third pass), and even multiples (fourth pass). A uniform image can be recorded without being affected by the position.

  Therefore, in the color 4-pass multi-pass printing mode according to the present embodiment, the unit printing pixel is completed with the paper feed amount of 62/600 dpi which is the total of the four paper feed amounts. Therefore, the nozzles indicated by 63 and 64 in FIG. 11 are not used, and only 62 nozzles 1 to 62 are used to record an image.

  Next, the image recording method of the present embodiment in the color 4-pass multi-pass recording mode will be described with reference to FIGS. 12 (a) to 12 (d) and FIGS. 13A and 13B.

  12 (a) to 12 (d) are multi-pass recording modes in which recording is performed in four passes, where 1/600 inch square is a unit recording pixel, 4 dots are recorded in the unit recording pixel, and paper feed is 1/600 inch. It is a schematic diagram showing the dot arrangement in the case of repeating by even and odd multiples.

  FIG. 12A is a schematic diagram showing a dot arrangement when the first pass printing is started by the Even nozzle while the carriage is traveling in the main scanning (x) direction.

  FIG. 12B is a schematic diagram showing the dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the main scanning (x) direction.

  FIG. 12C is a schematic diagram showing the dot arrangement when the first pass printing is started by the even nozzle while the carriage is traveling in the direction opposite to the main scanning (x) direction.

  FIG. 12D is a schematic diagram showing the dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the direction opposite to the main scanning (x) direction.

  In FIGS. 12A to 12D, 201 is a first-pass recording dot, 202 is a second-pass recording dot, 203 is a third-pass recording dot, and 204 is a fourth-pass recording dot. Show. Actually, the four types of recording dots in the first to fourth passes are combined and one main droplet and two satellites are formed in FIGS. 12 (a) to 12 (d). These represent the gradation of the unit recording pixel. However, in the following description, the above expression is used for simple explanation. 12A to 12D appear as follows on the recording medium. That is, FIG. 12A and FIG. 12B (or FIG. 12C and FIG. 12D) appear alternately every 1 / D inch in the paper feed direction.

  12 (a) to 12 (d), arrows (←, →) described in the unit recording pixels indicate the traveling direction of the carriage in each pass recording, and E is a dot recorded by the Even nozzle, O indicates a dot recorded by the Odd nozzle.

  Also, the inclination of the ink droplet ejection direction of the Odd nozzle and the Even nozzle is a diagram when the Even nozzle is inclined in the main scanning (x) direction and the Odd nozzle is inclined in the opposite direction.

  Next, with reference to FIGS. 12A to 12D and FIGS. 13A to 13B described above, image recording in the multi-pass recording mode (four passes) will be described in detail.

  First, FIG. 12A will be described.

  In FIG. 12A, in the first pass, recording is performed using an arbitrary Even nozzle while the carriage is moving in the x direction, so that the main droplet and the satellite land at separate positions. When the first pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 13A, the unit pass pixel recording in the first pass is performed using, for example, the Even nozzle 2, and after the first pass recording is finished, 15/600 inch paper feed is performed.

  Next, in the second pass, since recording is performed using an arbitrary Odd nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, the main droplet and the satellite are separated from each other (however, in the first pass, Land in the opposite direction). When the second pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 13A, the same unit recording pixel in the second pass is recorded using the odd nozzle 17, and after the second pass recording is completed, the paper is fed by 15/600 inches.

  Next, in the third pass, since recording is performed using an arbitrary Odd nozzle while the carriage is moving in the x direction, the main droplet and the satellite land at close positions. When the third pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 13A, the same unit recording pixel in the third pass is recorded using the odd nozzle 33, and after the third pass recording is finished, 16/600 inch paper feeding is performed.

  Next, in the fourth pass, since recording is performed using an arbitrary Odd nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, the main droplet and satellite land at a distant position. When the fourth pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 13A, recording of the same unit recording pixel in the fourth pass is performed using the odd nozzle 49, and after the recording of the fourth pass is completed, 16/600 inch paper feed is then performed.

  When the above-described four-pass image recording is performed, as shown in FIG. 12A, recording is performed by one satellite equally on the left and right of the pixels recorded by the main droplet.

  Next, FIG. 12B will be described.

  Next, in FIG. 12B, in the first pass, recording is performed using an arbitrary Odd nozzle while the carriage is moving in the x direction, so the main droplet and satellite land at close positions. When the first pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 13B, the unit recording pixels in the first pass are recorded using, for example, the Odd nozzle 1, and after the recording in the first pass is completed, 15/600 inch paper feed is performed.

  Next, in the second pass, since recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, it lands at a position close to the main droplet and the satellite. When the second pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 13B, the same unit recording pixel in the second pass is recorded using the Even nozzle 18, and after the second pass recording is completed, the paper feed of 15/600 inches is performed.

  Next, in the third pass, since recording is performed using an arbitrary Even nozzle while the carriage is moving in the x direction, the main droplet and the satellite land at a distant position. When the third pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 13B, recording of the same unit recording pixel in the third pass is performed using the Even nozzle 34, and after the third pass recording is finished, 16/600 inch paper feeding is performed.

  Next, in the fourth pass, recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, so that the main droplet and satellite land at close positions. When the fourth pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 13B, recording of the same unit recording pixel in the fourth pass is performed using the Even nozzle 50, and after the recording of the fourth pass is completed, 16/600 inch paper feed is then performed.

  When the above-described four-pass image recording is performed, recording by one satellite is performed to the right of the pixel recorded by the main droplet as shown in FIG.

  12 (c) and 12 (d) differ from FIGS. 12 (a) and 12 (b) described above in that the carriage traveling direction in each pass is opposite. Therefore, in FIG. 12C, recording is performed with one satellite to the left of the pixel recorded by the main droplet, and in FIG. 12D, one pixel is equally distributed to the left and right of the pixel recorded by the main droplet. However, detailed description is omitted here.

  In the second embodiment, FIG. 12A and FIG. 12B alternately appear every 1 / D inch in the paper feed direction, and specifically, pixels in which satellites appear on the left and right of the main droplet. (Pixels in FIG. 12A) and pixels in which satellites appear only on the right side of the main droplet (pixels in FIG. 12B) alternately appear every 1 / D inch in the paper feed direction. Alternatively, FIG. 12C and FIG. 12D alternately appear every 1 / D inch in the paper feed direction, and specifically, pixels in which satellites appear only on the left side of the main droplet (FIG. 12 ( The pixel c) and the pixels in which satellites appear on the left and right of the main droplet (pixels in FIG. 12D) alternately appear every 1 / D inch in the paper feed direction. Therefore, in the case of image recording in the second embodiment, satellites cannot appear evenly on the left and right of the main droplet for all pixels as in the case of image recording in the first embodiment.

  However, in the case of the second embodiment shown in FIG. 12, all the units that have been a problem in the case of the prior art explained in FIG. The problem that the recording pixel is recorded by only one of the even and odd nozzles can be solved. Further, in the second embodiment, since the pixels in which satellites appear on the left and right of the main droplet and the pixels in which satellites appear on either the left and right of the main droplet alternately appear, the main pixels as shown in FIG. Compared to a configuration in which pixels in which satellites appear on the right side of the droplet and pixels in which satellites appear on the left side of the main droplet alternately appear, the satellite bias can be reduced.

  Similarly, in the case of the second embodiment, since satellites appear for all pixels while including pixels where satellites appear on the left and right of the main droplet, the left and right sides of the main droplet as shown in FIG. Image deterioration due to satellites can be reduced compared to a configuration in which pixels in which satellites appear and pixels in which satellites do not appear alternately appear.

  As described above, in the 4-pass printing, if the paper feeding of the printing medium is repeated by odd number times, odd number times, odd number times, and even number times of 1/600 inch, all unit print pixels are even, odd, and odd. The dots ejected from the nozzles can be mixed and recorded. Furthermore, the pixels where satellites appear on the left and right of the main drop and the pixels where satellites appear on either the left and right of the main drop are alternated every 1 / D inch in the paper feed direction so that image degradation due to satellites is not noticeable as much as possible. Therefore, the uniformity of the entire image is improved as compared with the conventional configuration in FIGS. 4 and 5, and as a result, non-uniform image recording can be avoided and good image recording can be performed. An ink jet printer can be provided.

  In the above description, four-pass printing has been described as an example, but the above description can be applied to multi-pass printing with two or more passes. In the above description, the Even and Odd nozzles of the recording heads for each ink are arranged in different nozzle rows, but the arrangement of the recording heads is other than the above example, for example, the Even and Odd nozzles are in the same row. The print heads may be arranged in a single row.

  When the nozzle array of the recording head is arranged with a density of D per inch (Ddpi) and a nozzle pitch P (P = 1 / D), a paper feed roller for conveying the recording medium is provided. The resolution of one pulse of the motor to be driven may be D dots per inch (Ddpi) or a multiple thereof in terms of the transport amount.

[Third Embodiment]
Next, an ink jet printer according to a third embodiment will be described.

  The mechanical configuration, control configuration, and printhead of the ink jet printer of the third embodiment are the same as those of the ink jet printer described in the first embodiment (FIG. 1), control configuration (FIG. 6), and printhead ( The thing of the same structure as FIG. 7, 8) can be used. Accordingly, the description of the mechanical configuration, the control configuration, and the recording head of the ink jet printer according to the third embodiment will be omitted, and the description thereof will be omitted in the following description.

[Multipass recording mode]
Next, a multi-pass recording mode using the above-described ink jet printer and recording head will be described.

  In the following description, as an example of a multi-pass printing mode (m is 2 or more) in which a color nozzle row is divided into m and an image is completed by m scans, m = 4 is divided into four and four scans are performed. A description will be given using a four-pass recording mode for completing an image.

  First, features of the third embodiment will be described.

  In the first embodiment and the second embodiment, the case where the volume of ink droplets ejected from the even nozzle and the odd nozzle is the same has been described, but in the third embodiment, the volume of ink droplets ejected from the even nozzle is the same. The only difference is that the ink volume ejected from the Odd nozzle is small (small dot).

  That is, the number of nozzles, nozzle length, and nozzle pitch of the recording head used in the third embodiment are the same as those of the recording head described in the first embodiment, but the volume of ink droplets ejected from the Even nozzle is large. The difference is that the volume of ink ejected from the Odd nozzle is small. Therefore, the recording head according to the third embodiment is the same as the recording head according to the first embodiment (FIGS. 8, 10A, and 10B). Therefore, in the following description, the same diagram (FIGS. 8, 10A, and 10B) is used. explain.

  In the third embodiment, in the four-pass multi-pass printing mode similar to the first embodiment, the four paper feed amounts of the recording medium are alternately set to even / odd paper feed amounts of 1 / D inch. The case where this invention is applied about the case where it conveys is demonstrated.

  Next, the image recording method of this embodiment in the color 4-pass multi-pass recording mode will be described with reference to FIGS. 14 (a) to 14 (d).

  14 (a) to 14 (d) are multi-pass recording modes in which recording is performed in four passes, and 1/600 inch square is a unit recording pixel, and recording of two large dots and two small dots is recorded on the unit recording pixel. It is a schematic diagram showing a dot arrangement when feeding is repeated by even times and odd times of 1/600 inch.

  FIG. 14A is a schematic diagram showing a dot arrangement when the first pass printing is started by the Even nozzle while the carriage is traveling in the main scanning (x) direction.

  FIG. 14B is a schematic diagram showing the dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the main scanning (x) direction.

  FIG. 14C is a schematic diagram showing the dot arrangement when the first pass printing is started by the Even nozzle while the carriage is traveling in the direction opposite to the main scanning (x) direction.

  FIG. 14D is a schematic diagram showing the dot arrangement when the first pass printing is started by the odd nozzle while the carriage is traveling in the direction opposite to the main scanning (x) direction.

  In FIGS. 14A to 14D, 301 is a recording dot for the first pass, 302 is a recording dot for the second pass, 303 is a recording dot for the third pass, and 304 is a recording dot for the fourth pass. Show. Actually, the four types of recording dots in the first to fourth passes are recorded overlappingly, and in the case of FIGS. 14A to 14D, one main droplet and one satellite are formed. These represent the gradation of the unit recording pixel. However, in the following description, the above expression is used for simple explanation. 14A to 14D appear on the recording medium as follows. That is, FIG. 14A and FIG. 14B (or FIG. 14C and FIG. 14D) appear alternately every 1 / D inch in the paper feed direction.

  Further, in FIGS. 14A to 14D, arrows (←, →) described in the unit recording pixels indicate the traveling direction of the carriage in each pass recording, and E is a dot recorded by the Even nozzle, O indicates a dot recorded by the Odd nozzle.

  Also, the inclination of the ink droplet ejection direction of the Odd nozzle and the Even nozzle is a diagram when the Even nozzle is inclined in the main scanning (x) direction and the Odd nozzle is inclined in the opposite direction.

  Next, image recording in the multipass recording mode (4 passes) will be described in detail with reference to FIGS. 14A to 14D and FIGS. 10A and 10B described above.

  First, FIG. 14A will be described.

  In FIG. 14A, in the first pass, large dots are recorded using an arbitrary Even nozzle while the carriage is moving in the x direction, so that the main droplet and satellite land at separate positions. When the first pass recording is completed, a paper feed of 16/600 inches is performed. That is, the unit recording pixels in the first pass in FIG. 10A are recorded using, for example, the Even nozzle 2, and after the recording in the first pass is completed, the paper is fed by 16/600 inches.

  Next, in the second pass, since a small dot is recorded using an arbitrary Odd nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, the main droplet and the satellite are separated from each other (however, 1 Land at a position away from the pass). When the second pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, the same unit recording pixel in the second pass is recorded using the Odd nozzle 17, and after the second pass recording is completed, the paper feed of 15/600 inches is performed.

  Next, in the third pass, since a small dot is recorded using an arbitrary odd nozzle while the carriage is moving in the x direction, the main droplet and satellite land at close positions. When the third pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10A, the same unit recording pixel in the third pass is recorded using the odd nozzle 33, and after the third pass recording is completed, the paper feed of 16/600 inches is performed.

  Next, in the fourth pass, since large dots are recorded using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, the main droplet and satellite land at close positions. When the fourth pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, recording of the same unit recording pixel in the fourth pass is performed using the Even nozzle 50, and after the recording of the fourth pass is completed, 15/600 inch paper feed is then performed.

  When the above-described four-pass image recording is performed, as shown in FIG. 14A, recording by one satellite is performed equally on the left and right of the pixels recorded by the main droplet.

  Next, FIG. 14B will be described.

  Next, in FIG. 14B, in the first pass, small dot recording is performed using an arbitrary Odd nozzle while the carriage is moving in the x direction, so the main droplet and the satellite land at close positions. When the first pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10B, the unit recording pixels in the first pass are recorded using, for example, the Odd nozzle 1, and after the first pass recording is finished, the paper is then fed by 16/600 inches.

  Next, in the second pass, large dot recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, so that the ink lands at a position close to the main droplet and the satellite. When the second pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, the same unit recording pixel in the second pass is recorded using the Even nozzle 18, and after the second pass recording is completed, the paper feed of 15/600 inches is performed.

  Next, in the third pass, since large dot recording is performed using an arbitrary Even nozzle while the carriage is moving in the x direction, the main droplet and the satellite land on separate positions. When the third pass recording is completed, a paper feed of 16/600 inches is performed. That is, in FIG. 10A, the recording of the same unit recording pixel in the third pass is performed using the Even nozzle 34, and after the third pass recording is finished, the paper is fed by 16/600 inches.

  Next, in the fourth pass, small dot recording is performed using an arbitrary Even nozzle while the carriage is moving in the direction opposite to the main scanning (x) direction, so the main droplet and the satellite are separated from each other (however, three passes). Land at a position away from the eyes). When the fourth pass recording is completed, a 15/600 inch paper feed is performed. That is, in FIG. 10A, recording of the same unit recording pixel in the fourth pass is performed using the odd nozzle 49, and after the recording of the fourth pass is completed, 15/600 inch paper feeding is performed.

  When the above-described four-pass image recording is performed, as shown in FIG. 14B, recording is performed by one satellite equally on the left and right of the pixels recorded by the main droplet.

  14 (c) and 14 (d) are different from FIGS. 14 (a) and 14 (b) described above only in that the traveling direction of the carriage in each pass is opposite. 14 (c) or FIG. 14 (d) is the same in that the recording by one satellite is equally performed on the left and right of the pixels recorded by the main droplet, and detailed description thereof will be given here. Is omitted.

  That is, when performing multi-pass printing (4-dot printing) using four passes on 600 inch square unit print pixels, as shown in FIGS. Recording is performed by one satellite each ejected from the Even and Odd nozzles on the left and right of the pixel recorded by the droplet.

  In the above description, four-pass printing has been described as an example, but the above description can be applied to multi-pass printing with two or more passes. In the above description, the Even and Odd nozzles of the recording heads for each ink are arranged in different nozzle rows, but the arrangement of the recording heads is other than the above example, for example, the Even and Odd nozzles are in the same row. The print heads may be arranged in a single row.

  As described above, in the inkjet printer of this embodiment, in multi-pass printing of two or more passes (four passes in the above-described example), the paper feed of the recording medium is 1 / D (1/600 inch in the above-described example). By repeating even and odd multiples, even and small dots ejected from the even and odd nozzles are evenly recorded on all unit recording pixels, and satellites are evenly recorded to the left and right of the main droplets. Is done. Therefore, non-uniform image recording can be avoided and good image recording can be performed.

  In the above first to third embodiments, as the paper conveyance executed between the passes, 1) an example in which the paper conveyance of the odd multiple of the nozzle pitch and the paper conveyance of the even multiple are alternately and sequentially repeated. ) Although an example has been described in which the odd-numbered paper conveyance of the nozzle pitch, the odd-numbered paper conveyance, the even-numbered paper conveyance, and the even-numbered paper conveyance are sequentially repeated, the present invention is limited to this paper conveyance method. is not. That is, according to the present invention, when performing multi-pass printing in which the recording head is scanned a plurality of times with respect to a predetermined area, and the recording of the predetermined area is completed by a plurality of scans of the recording head, As the conveyance, the paper conveyance may be executed by including the paper conveyance of the odd multiple of the nozzle pitch and the paper conveyance of the even multiple of the nozzle pitch at least once.

  In the above embodiment, the liquid droplets ejected from the recording head have been described as ink, and the liquid stored in the ink tank has been described as ink. However, the container is limited to ink. It is not a thing. For example, a treatment liquid discharged to the recording medium may be accommodated in the ink tank in order to improve the fixability and water resistance of the recorded image or to improve the image quality.

  The above embodiment includes means (for example, an electrothermal converter, a laser beam, etc.) that generates thermal energy as energy used for performing ink discharge, particularly in the ink jet recording system, and the ink is generated by the thermal energy. By using a system that causes a change in the state of recording, it is possible to achieve higher recording density and higher definition.

  As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both a so-called on-demand type and a continuous type. In particular, in the case of the on-demand type, it corresponds to a sheet or a liquid path that holds liquid (ink). By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling to the arranged electrothermal transducer, thermal energy is generated in the electrothermal transducer, and recording is performed. This is effective because film boiling occurs on the heat acting surface of the head, and as a result, bubbles in the liquid (ink) corresponding to the drive signal on a one-to-one basis can be formed.

  By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable that the drive signal has a pulse shape, since the bubble growth and contraction is performed immediately and appropriately, and thus it is possible to achieve discharge of a liquid (ink) having particularly excellent responsiveness.

  As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.

  As the configuration of the recording head, in addition to the combination configuration (straight liquid flow path or right-angle liquid flow path) of the discharge port, the liquid path, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting surface The configurations described in US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which is arranged in a bending region, are also included in the present invention. In addition, Japanese Patent Application Laid-Open No. 59-123670, which discloses a configuration in which a common slot is used as a discharge portion of an electrothermal transducer, or an opening that absorbs a pressure wave of thermal energy is discharged to a plurality of electrothermal transducers. A configuration based on Japanese Patent Laid-Open No. 59-138461 disclosing a configuration corresponding to each part may be adopted.

  Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is satisfied by a combination of a plurality of recording heads as disclosed in the above specification. Either a configuration or a configuration as a single recording head formed integrally may be used.

  In addition to the cartridge-type recording head in which the ink tank is integrally provided in the recording head itself described in the above embodiment, it can be electrically connected to the apparatus body by being attached to the apparatus body. A replaceable chip type recording head that can supply ink from the apparatus main body may be used.

  In addition, it is preferable to add recovery means, preliminary means, and the like for the recording head to the configuration of the recording apparatus described above because the recording operation can be further stabilized. Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressurizing or sucking unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof. In addition, it is effective to provide a preliminary ejection mode for performing ejection different from recording in order to perform stable recording.

  Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrated or may be a combination of a plurality of colors. An apparatus having at least one of full colors can also be provided.

  In the embodiment described above, the description is made on the assumption that the ink is a liquid, but it may be an ink that is solidified at room temperature or lower, or an ink that is softened or liquefied at room temperature, Alternatively, the ink jet method generally controls the temperature of the ink so that the viscosity of the ink is within a stable discharge range by adjusting the temperature within a range of 30 ° C. or higher and 70 ° C. or lower. It is sufficient if the ink sometimes forms a liquid.

  In addition, it is solidified in a stand-by state in order to actively prevent temperature rise by heat energy as energy for changing the state of ink from the solid state to the liquid state, or to prevent ink evaporation. Ink that is liquefied by heating may be used. In any case, by applying heat energy according to the application of thermal energy according to the recording signal, the ink is liquefied and liquid ink is ejected, or when it reaches the recording medium, it already starts to solidify. The present invention can also be applied to the case where ink having a property of being liquefied for the first time is used.

  In such a case, the ink is held as a liquid or solid in a porous sheet recess or through-hole as described in JP-A-54-56847 or JP-A-60-71260, It is good also as a form which opposes with respect to an electrothermal converter. In the present invention, the most effective one for each of the above-described inks is to execute the above-described film boiling method.

  In addition, as a form of the recording apparatus according to the present invention, a copying apparatus combined with a reader or the like, and a transmission / reception function are provided as an image output terminal of an information processing apparatus such as a computer or the like. It may take the form of a facsimile machine.

[Other Embodiments]
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device. You may apply to.

  Another object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and the computer (or CPU or CPU) of the system or apparatus. Needless to say, this can also be achieved by the MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Furthermore, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion card or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

  When the present invention is applied to the storage medium, the storage medium stores program codes corresponding to those shown in FIGS. 10A, 10B, 13A, and 13B described above.

It is a figure explaining the structure of the principal part of the inkjet printer using a multihead. It is a figure explaining the schematic diagram of the discharge outlet arranged in a multihead. (A) Landing positions of main droplets and satellites when the ink droplet ejection direction is perpendicular to the paper surface, (b) when tilted in the carriage traveling direction, and (c) when tilted in the opposite direction of the carriage traveling direction FIG. In the conventional 4-pass multi-pass printing, the transport amount of the recording medium is an even multiple of 1 / D inch, the Even nozzle is inclined in the ink droplet ejection direction in the main scanning direction, and the Odd nozzle is opposite to the main scanning direction. FIG. 6 is a schematic diagram showing four types of dot arrangement formed when the ink droplet ejection direction is inclined. In the conventional 4-pass multi-pass printing, the transport amount of the recording medium is an odd multiple of 1 / D inch, the Even nozzle is inclined in the ink droplet ejection direction in the main scanning direction, and the Odd nozzle is opposite to the main scanning direction. FIG. 6 is a schematic diagram showing four types of dot arrangement formed when the ink droplet ejection direction is inclined. It is a block diagram which shows the control structure of the inkjet printer which concerns on one Embodiment of this invention. 1 is a schematic diagram of a recording head according to an embodiment of the present invention. FIG. 5 is a schematic diagram illustrating an Even nozzle, an Odd nozzle, and a paper feed amount of the recording head according to the first embodiment of the invention. In the 4-pass printing according to the first embodiment of the present invention, the Even nozzle is formed when the ink droplet discharge direction is inclined in the main scanning direction, and the Odd nozzle is formed when the ink droplet discharge direction is inclined opposite to the main scanning direction. It is a schematic diagram which shows four types of dot arrangements. It is a schematic diagram explaining the recording method by 4 pass recording (in the case of Fig.9 (a)) in the 1st Embodiment of this invention. It is a schematic diagram explaining the recording method by 4 pass recording (in the case of FIG.9 (b)) in the 1st Embodiment of this invention. FIG. 10 is a schematic diagram illustrating an Even nozzle, an Odd nozzle, and a paper feed amount of a recording head according to a second embodiment of the present invention. It is a schematic diagram which shows the dot arrangement | positioning by 4-pass printing in the 2nd Embodiment of this invention. It is a schematic diagram explaining the recording method by 4-pass recording in the 2nd Embodiment of this invention. It is a schematic diagram explaining the recording method by 4-pass recording in the 2nd Embodiment of this invention. In the 4-pass printing in the third embodiment of the present invention, the Even nozzle is formed when the ink droplet discharge direction is inclined in the main scanning direction, and the Odd nozzle is formed when the ink droplet discharge direction is inclined opposite to the main scanning direction. It is a schematic diagram which shows four types of dot arrangements.

Explanation of symbols

101 First-pass recording dot 102 Second-pass recording dot 103 Third-pass recording dot 104 Fourth-pass recording dot 201 First-pass recording dot 202 Second-pass recording dot 203 Third-pass recording dot 204 4th pass printing dot 301 1st pass printing dot 302 2nd pass printing dot 303 3rd pass printing dot 304 4th pass printing dot 401 1st pass printing dot in conventional method 402 2nd pass in conventional method First recording dot 403 Third recording dot in the conventional method 404 Fourth recording dot in the conventional method 1101 Inkjet cartridge 1102 Multihead 1103 Paper feed roller 1104 Auxiliary roller 1105 Paper feed roller 1106 Carriage 1201 Nozzle 1301 Main droplet 1302 Satellite 1303 Carriage traveling direction 1304 Discharge inclination direction 405 Carriage traveling direction in each pass 600 CPU
601 ROM
602 RAM
603 Image input unit 604 Image signal processing unit 605 Main bus line 606 Operation unit 607 Recovery system control circuit 608 Recovery system motor 609 Cleaning blade 610 Cap 611 Suction pump 612 Thermistor 613 Recording head 614 Head temperature control circuit 615 Head drive control circuit 616 Carriage Drive circuit 617 Paper feed control circuit 701 Black Odd nozzle array 702 Black Even nozzle array 703 Color Odd nozzle array 704 Color Even nozzle array P Recording medium E Dot recorded by Even nozzle O Odot recorded by Odd nozzle

Claims (5)

The first direction and the first direction crossing the recording head in which a plurality of nozzles for ejecting ink droplets of the same color are arranged at a predetermined interval to the arrangement direction of the nozzles is scanned in the opposite second direction, An image for recording on the pixel area by ejecting ink droplets from different nozzles to the pixel area of the recording medium in a plurality of scans including scanning in the first direction and scanning in the second direction. A recording device,
In an even multiple of the conveying amount by the conveying said plurality of scans of the conveyance of an odd multiple of the conveying quantity of the recording medium is interposed at least once in the interval of the recording medium of the interval in the transport direction of the recording medium When a plurality of a predetermined number of ink droplets are ejected toward each of the plurality of pixel regions arranged along, the predetermined number of inks on both sides in the scanning direction of the position where the main droplets of the predetermined number of ink droplets overlap. An image recording apparatus characterized in that a satellite of a droplet lands . The image recording apparatus according to claim 1, wherein a length of the pixel region in the transport direction is substantially equal to the interval . The image recording apparatus according to claim 1 or 2, characterized in that the transport is performed alternately by the conveying and transporting of the odd multiple by conveying amount of the even times. The plurality of nozzles arranged at the predetermined interval includes a nozzle constituting the first nozzle row and a nozzle constituting the second nozzle row,
The satellites of the ink droplets ejected from the first nozzle row land at positions shifted in the one direction with respect to the position where the main droplets overlap,
4. The satellite according to claim 1 , wherein the satellites of the ink droplets ejected from the second nozzle row land at positions shifted in the two directions with respect to a position where the main droplets overlap . 5. Image recording device. Scanning a recording head in which a plurality of nozzles for ejecting ink droplets of the same color are arranged at a predetermined interval in a first direction intersecting the nozzle arrangement direction and a second direction opposite to the first direction; image for performing the recording on the pixel area by ejecting ink droplets onto the pixel region of the plurality of recording media from different nozzles in the scanning including scanning to scan and the second direction to the first direction A recording method,
Between the scanning in the scanning and the second direction to the first direction, alternately conveying the recording medium by the conveyance amount of an odd multiple of the transport and the distance of the recording medium by an even multiple of the conveying quantity of the gap A process of performing;
A step of ejecting ink droplets from the recording head toward the pixel area in the plurality of scans including conveyance of the recording medium by the even-numbered conveyance amount and conveyance of the recording medium by the odd-numbered conveyance amount. Have
When a plurality of predetermined number of ink droplets are ejected by the plurality of scans toward each of a plurality of pixel regions arranged along the conveyance direction of the recording medium, the main droplets of the predetermined number of ink droplets are An image recording method , wherein the satellites of the predetermined number of ink droplets land at positions shifted in the first direction and positions shifted in the second direction with respect to overlapping positions.

Images