JP2004001578A - Dot recording method, dot recorder, and recording medium therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable sub scanning/feeding other than "minute feeding" at a lower end process. <P>SOLUTION: Dot recording (upper end process) is carried out by a first recording mode near an upper end of a recording execution region of a recording medium. Dot recording (intermediate process) is carried out by a second recording mode at an intermediate part of the recording execution region. Moreover, dot recording (lower end process) is carried out near a lower end of the recording execution region by a third recording mode in which at least a sub scanning/feeding amount is made different from that of the second recording mode. A sub scanning/feeding pattern in one of the first and third recording modes is adjusted so that a predetermined one kind of sub scanning/feeding can be carried out in the other recording mode. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a technique for printing dots on the surface of a recording medium using a dot recording head, and more particularly to dot recording including upper and lower ends processing for expanding a recordable area on a recording medium.

記録 As a recording device that performs recording while the recording head scans in the main scanning direction and the sub-scanning direction, there are a serial scan printer, a drum scan printer, and the like. In a printer of this type (especially an ink jet printer), in order to expand an area where printing is performed (hereinafter, referred to as a “print execution area” or a “print area”), the vicinity of the upper end and the lower end of the print execution area A printing process different from that in the middle part of the recording execution area is performed. In this specification, print processing in the middle part of the recording execution area is called “intermediate processing”, printing processing in the vicinity of the upper end of the recording execution area is referred to as “upper processing”, and printing in the vicinity of the lower end of the recording execution area. Is referred to as “lower end processing”. When the upper end processing and the lower end processing are collectively called, they are called “upper / lower end processing”.

(4) Before describing the contents of the upper and lower ends processing, some conventional recording methods employed in the intermediate processing will be described first. As one of the recording methods for improving the image quality, there is a technique called "interlace method" disclosed in U.S. Pat. No. 4,198,642 and JP-A-53-2040.

FIG. 34 is an explanatory diagram showing an example of the interlace method. In this specification, the following are used as parameters that define the recording method.

N: Number of nozzles [pcs],
k: Nozzle pitch [dot],
s: number of scan repetitions,
D: Nozzle density [pcs / inch],
L: Sub-scan feed amount [dot] or [inch],
w: Dot pitch [inch].

The number of nozzles N [number] is the number of nozzles used for forming dots. In the example of FIG. 34, N = 3. The nozzle pitch k [dot] indicates how many nozzle pitches of the print head are equal to the pitch (dot pitch w) of the print image. In the example of FIG. 34, k = 2. The number of scan repetitions s [times] is a number indicating the number of main scans in which each main scan line is filled with dots. Hereinafter, the main scanning line is also referred to as “raster”. In the example of FIG. 34, s = 1 since each raster is filled in one main scan. As described later, when s is 2 or more, dots are formed intermittently along the main scanning direction. The nozzle density D [pieces / inch] indicates how many nozzles are arranged per inch in the nozzle array of the print head. The sub-scan feed amount L [dot] or [inch] indicates the distance moved by one sub-scan. The dot pitch w [inch] is a dot pitch in a recorded image. Generally, w = 1 / (D · k) and k = 1 / (D · w) hold.

に お い て In FIG. 34, circles including two-digit numbers indicate dot recording positions. As shown in the legend at the lower left of FIG. 34, among the two-digit numbers in the circle, the numbers on the left indicate the nozzle numbers, and the numbers on the right indicate the recording order (recording number in the main scan). Has been shown).

イ ン タ ー The interlace method shown in FIG. 34 is characterized by the configuration of the nozzle array of the recording head and the sub-scanning method. That is, in the interlace method, the nozzle pitch k indicating the center point interval between the adjacent nozzles is set to an integer of 2 or more, and the number of nozzles N and the nozzle pitch k are selected to be integers having a prime relationship. The sub-scan feed amount L is set to a constant value given by N / (D · k).

(4) The interlace method has an advantage that variations in nozzle pitch, ink ejection characteristics, and the like can be dispersed on a printed image. Therefore, even if there is a variation in the nozzle pitch and the discharge characteristics, the effect is obtained that the effects can be reduced and the image quality can be improved.

As another technique for improving image quality in a color ink jet printer, there is a technique called "overlap method" or "multi-scan method" disclosed in Japanese Patent Application Laid-Open No. Hei 3-207665 and Japanese Patent Publication No. Hei 4-19030. .

FIG. 35 is an explanatory diagram showing an example of the overlap method. In this shingling system, eight nozzles are classified into two nozzle groups. The first set of nozzle groups is composed of four nozzles with even nozzle numbers (the number on the left side of the circle), and the second set of nozzle groups is with four odd nozzle numbers. It is composed of nozzles. In one main scan, dots are formed at every (s−1) dots in the main scan direction by driving each set of nozzle groups at intermittent timing. In the example of FIG. 35, since s = 2, dots are formed every other dot. The driving timing of each nozzle group is controlled so that dots are formed at different positions in the main scanning direction. That is, as shown in FIG. 35, the nozzles of the first nozzle group (nozzle numbers 8, 6, 4, 2) and the nozzles of the second nozzle group (nozzle numbers 7, 5, 3, 1) are: The recording position is shifted by one dot pitch in the main scanning direction. Then, such main scanning is performed a plurality of times, and the driving timing of each nozzle group is shifted each time, thereby completing the formation of all dots on the raster.

ノ ズ ル Also in the overlap method, the nozzle pitch k is set to an integer of 2 or more, similarly to the interlace method. However, the number of nozzles N and the nozzle pitch k do not have a relatively prime relationship. Instead, a value N / s obtained by dividing the number of nozzles N by the number of scan repetitions s and the nozzle pitch k have a relatively prime relationship. Selected as an integer. The sub-scan feed amount L is set to a constant value given by N / (sDk).

In the overlap method, dots on each raster are not recorded by the same nozzle, but are recorded by using a plurality of nozzles. Therefore, even when the characteristics (pitch, ejection characteristics, etc.) of the nozzles vary, it is possible to prevent the effects of the characteristics of a specific nozzle from affecting the entirety of one raster, thereby improving the image quality. .

In the above-described interlace method and overlap method, the sub-scan feed is executed at a constant feed amount L for a plurality of dots.

The upper and lower end processing of the printer is a special print processing performed near the upper end and the lower end of the recording execution area in order to extend the recording execution area of the printer as much as possible. As the upper and lower end processing, for example, there is a technique described in Japanese Patent Application Laid-Open No. Hei 7-242025 disclosed by the present application. In FIG. 9 of this publication, printing by the interlace method is performed in the middle part of the recording execution area, and printing (lower end processing) by “small feed” (sub scanning of one dot) is performed near the lower end of the recording execution area. It is shown to be done. As can be seen by comparing FIG. 8 (without lower end processing) and FIG. 9 (with lower end processing) of the publication, the lower end of the recording execution area is enlarged as a result of the lower end processing.

In “fine feed”, the nozzle moves in the sub-scanning direction one dot at a time. Therefore, no matter what kind of sub-scan feed is performed in the intermediate processing, the lower end of “fine feed” can set the lower end of the print execution area to the desired position. It is possible to extend to the range of. On the other hand, there is also a demand for adopting a recording method using a sub-scan feed other than the “fine feed” in the lower end processing. For example, in order to improve image quality, there is a demand to adopt a recording method using a sub-scan feed amount for a plurality of dots, such as an interlace method or an overlap method. However, depending on the manner of sub-scan feed in the intermediate process, if a sub-scan feed other than “small feed” is applied in the lower end process, a portion that cannot be printed occurs in the recording execution area that should be extended by the lower end process. In some cases, the recording execution area cannot be actually expanded. For this reason, conventionally, depending on the manner of sub-scan feed in the intermediate processing, sub-scan feed other than "fine feed" may not be used in the lower end processing. In addition, when the sub-scan feed other than the “fine feed” is performed in the lower end process, the lower end process may be too complicated.

The present invention has been made to solve the above-described problem in the conventional technology, and has as its first object to provide a technique that enables a sub-scan feed other than “fine feed” in lower end processing. A second object is to prevent the lower end process from being excessively complicated when performing the sub-scan feed other than the “fine feed” in the lower end process.

To solve at least a part of the problems described above, a dot recording apparatus of the present invention is a dot recording apparatus that records dots on the surface of a print medium using a dot recording head,
A dot forming element array in which a plurality of dot forming elements for forming a plurality of dots of the same color at a substantially constant pitch along a sub-scanning direction are arranged at a portion of the dot recording head facing the print medium. When,
Main scanning drive means for performing main scanning by driving at least one of the dot recording head and the printing medium,
Head driving means for driving at least a part of the plurality of dot forming elements to form dots during the main scanning,
Sub-scanning driving means for performing sub-scanning by driving at least one of the dot recording head and the printing medium each time the main scanning is completed,
Control means for controlling each of the means,
The control means includes:
(I) a function of printing dots in a first printing mode near the upper end of a printing execution area of the print medium;
(Ii) a function of printing dots in a second printing mode in an intermediate portion of the printing execution area;
(Iii) near the lower end of the print execution area, a function of printing dots in a third print mode having at least a sub-scan feed amount different from the second print mode;
(Iv) irrespective of the length of the print execution area in the sub-scanning direction, a predetermined set of sub-scan feed patterns is set for one of the first and third print modes selected in advance. A function of selecting one of a plurality of sub-scan feed patterns for the other print mode in accordance with the length of the print execution area in the sub-scan direction. And The first and second recording modes do not necessarily need to be different, and may be the same.

In the dot recording apparatus, one of a plurality of sub-scanning feed patterns is selected for one of the first and third recording modes, and a predetermined set of sub-scanning feed patterns is used in the other recording mode. Therefore, it is possible to use a sub-scan feed other than “fine feed” in the lower end processing. Also, when performing sub-scan feed other than “small feed” in the lower end process, the lower end process can be prevented from becoming excessively complicated.

The function (iV) is a function of the plurality of sub-scanning feed patterns for the third printing mode so that the predetermined set of sub-scanning feed patterns can be used for the first printing mode. In the third printing mode, each dot is selected during the main scanning based on the dot printing history up to the vicinity of the lower end of the printing execution area in the second printing mode. It is preferable to include a function of adjusting the position of the dot recorded by the forming element.

In the third printing mode, the dot position to be printed by each dot forming element is adjusted so that a portion that cannot be printed near the lower end of the printing execution area does not occur. By the way, also in the second printing mode, since a part near the lower end of the printing execution area is printed, the dot position to be printed in the third printing mode depends on the dot printing history in the second printing mode. I do. Therefore, in the third printing mode, if the position of the dot printed by each dot forming element during the main scanning is adjusted based on the dot printing history in the second printing mode, the “fine Even if a sub-scan feed other than "feed" is employed, it is possible to prevent the occurrence of an unprintable portion in the print execution area.

In the above-described dot recording apparatus, the plurality of sub-scanning feed patterns that can be used in the third printing mode may include a feed amount of a transient sub-scanning feed that is performed as needed at the start of the third printing mode. Are different patterns from each other,
The function (iV) is
A function of selecting one of the plurality of sub-scanning feed patterns for the third printing mode based on a history of the sub-scanning feed amount up to near the lower end of the print execution area. preferable.

When shifting from the second printing mode to the third printing mode, if necessary, the sub-scanning using the transient feed amount is executed to print the dots. Immediately transitioning to the third recording mode, even if the recording execution area cannot be extended by a desired range, the extension can be performed well. Therefore, a sub-scan feed other than the "fine feed" can be employed in the lower end processing.

In the above-described dot recording apparatus, the second recording mode is a mode in which a sub-scan is executed by repeatedly using a combination of a plurality of different sub-scan feed amounts as one unit cycle,
It is preferable that the third recording mode is a mode in which, after the transient sub-scan feed, a sub-scan is executed using a constant sub-scan feed amount for a plurality of dots.

In the case where the sub-scan in the second and third print modes uses such a feed amount, if the process immediately shifts from the second print mode to the third print mode, the print execution area may not be extended to a desired range. Relatively high. Therefore, in such a case, if the sub-scan is performed with the transitional feed amount as necessary, the recording execution area can be expanded successfully.

In the dot recording apparatus, the necessity of the transient sub-scan feed in the third recording mode and the value of the feed amount of the transient sub-scan feed are determined according to the second sub-scan mode. When it is assumed that the sub-scanning is continued, it is determined according to the value of the sub-scan feed amount when the lower end element of the plurality of dot forming elements reaches a position after the lower end line of the print execution area. Preferably.

With this configuration, it is possible to easily determine the necessity of sub-scanning based on the transitional feed amount and the value of the feed amount.

In the above dot recording apparatus,
The necessity of the transient sub-scan feed in the third print mode and the value of the feed amount of the transient sub-scan feed are determined according to a value Vres given by the following equation. You may do so.
Vres = {(Lp−ΔL−Ln)%}
Here, Lp is the length of the print execution area in the sub-scanning direction, ΔL is the length from the upper end of the print execution area to the upper end of the area where the printing operation is performed in the second print mode, and Ln is The distance between the dot forming elements at both ends of the dot recording head, Σ is the total value of the sub-scan feed amount for one unit cycle in the second recording mode, and the operator “%” is an operation for taking the remainder of division. , Respectively.

Further, in the dot recording apparatus, the plurality of sub-scan feed patterns that can be used in the first print mode are patterns in which the sub-scan feed amount is constant and the number of sub-scan feeds is different from each other;
The second printing mode is a mode in which a sub-scan is executed by repeatedly using a combination of a plurality of different sub-scan feed amounts as one unit cycle,
The function (iV) may have a function of determining the number of sub-scan feeds in the first print mode so that the predetermined set of sub-scan feed patterns can be used in the third print mode. preferable.

In this way, a predetermined set of sub-scan feed patterns can be used as the lower end processing performed in the third recording mode. Therefore, even when the sub-scan feed other than the “fine feed” is used in the lower end process, the lower end process can be simplified.

In the dot recording apparatus, the number of sub-scan feeds in the first recording mode is determined by a positional relationship between a position of the dot recording head at a final recording position in the second recording mode and a lower end of the recording execution area. May be determined so as to fall within a predetermined range.

In this way, it is possible to relatively easily determine the sub-scan feed required in the first recording mode.

The number of sub-scan feeds in the first printing mode may be determined according to a value Vres given by the following equation.
Vres = {(Lp−ΔL−Ln)%}
Here, Lp is the length of the print execution area in the sub-scanning direction, ΔL is the length from the upper end of the print execution area to the upper end of the area where the printing operation is performed in the second print mode, and Ln is The distance between the dot forming elements at both ends of the dot recording head, Σ is the total value of the sub-scan feed amount for one unit cycle in the second recording mode, and the operator “%” is an operation for taking the remainder of division. , Respectively.

Further, in the above-described dot recording apparatus, the head driving unit may be configured such that, in each of the first to third recording modes, s (s is 2 or more) along the main scanning direction during one main scanning. It is preferable to drive the plurality of dot-forming element arrays at intermittent timings for prohibiting dot formation by (s-1) dots among dots of (integer).

れ ば Thus, the recording execution area can be expanded while improving the image quality.

The method of the present invention is a dot recording method for recording dots on the surface of a recording medium using a dot recording head having a plurality of dot forming elements,
(A) driving at least one of the dot recording head and the recording medium to perform main scanning;
(B) driving at least a part of the plurality of dot forming elements to form dots during the main scanning;
(C) performing a sub-scan by driving at least one of the dot recording head and the recording medium each time the main scanning is completed,
The plurality of dot forming elements can form a plurality of dots of the same color at a substantially constant pitch along the sub-scanning direction,
(I) In the vicinity of the upper end of the print execution area of the print medium, dot printing is performed by performing the steps (a) to (c) in the first printing mode,
(Ii) In an intermediate portion of the recording execution area, dots are recorded by executing the steps (a) to (c) in the second recording mode,
(Iii) In the vicinity of the lower end of the print execution area, the steps (a) to (c) are executed in the third print mode having at least a sub-scan feed amount different from that of the second print mode. Make a record,
(Iv) irrespective of the length of the print execution area in the sub-scanning direction, a predetermined set of sub-scan feed patterns is set for one of the first and third print modes selected in advance. One of a plurality of sub-scan feed patterns is selected for the other print mode in accordance with the length of the print execution area in the sub-scan direction so that the print execution area can be used.

Further, the recording medium of the present invention is used in a dot recording apparatus including a computer and a dot recording head having a plurality of dot forming elements, and performs recording of dots on the surface of a printing medium using the dot recording head. A computer-readable recording medium having recorded thereon a computer program,
The computer program comprises:
(I) a function of printing dots in a first printing mode near the upper end of a printing execution area of the print medium;
(Ii) a function of printing dots in a second printing mode having a sub-scanning feed amount different from that of the first printing mode in an intermediate portion of the printing execution area;
(Iii) near the lower end of the print execution area, a function of printing dots in a third print mode having at least a sub-scan feed amount different from the second print mode;
(Iv) irrespective of the length of the print execution area in the sub-scanning direction, a predetermined set of sub-scan feed patterns is set for one of the first and third print modes selected in advance. A function of selecting one of a plurality of sub-scan feed patterns for the other print mode according to the length of the print execution area in the sub-scan direction, so that it can be used;
Is realized by the computer.

According to these methods and recording media, similarly to the above-described dot recording apparatus, if the recording mode is immediately shifted from the second recording mode to the third recording mode, the recording execution area can be extended only in a desired range. Therefore, it is possible to employ a sub-scan feed other than the “small feed” in the lower end processing, and not to make the lower end processing excessively complicated.

The present invention includes the following other embodiments. A first aspect is an aspect as a program supply device that supplies a computer program for realizing the functions of each step or each means of the above-described invention to a computer via a communication path. In such an embodiment, the above-described image processing method and image processing apparatus can be realized by placing the program on a server or the like on a network, downloading the necessary program to a computer via a communication path, and executing the program. it can.

A. Equipment configuration:
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a printing apparatus as one embodiment of the present invention. As shown in the figure, the scanner 12 and the color printer 22 are connected to a computer 90, and a predetermined program is loaded and executed on the computer 90 to function as a printing apparatus as a whole. The hardware as the printing device is a normal computer 90. As shown in the figure, the computer 90 includes the following units interconnected by a bus 80, centering on a CPU 81 that executes various arithmetic processing for controlling operations related to image processing according to a program. The ROM 82 previously stores programs and data necessary for the CPU 81 to execute various arithmetic processes, and the RAM 83 temporarily reads and writes various programs and data necessary for the CPU 81 to execute various arithmetic processes. Memory. The input interface 84 controls input of signals from the scanner 12 and the keyboard 14, and the output interface 85 controls output of data to the printer 22. The CRTC 86 controls signal output to the CRT 21 capable of color display, and the disk controller (DDC) 87 controls data transfer with the hard disk 16, the flexible drive 15, or a CD-ROM drive (not shown). The hard disk 16 stores various programs loaded and executed in the RAM 83 and various programs provided in the form of device drivers. In addition, a serial input / output interface (SIO) 88 is connected to the bus 80. The SIO 88 is connected to the modem 18, and is connected to the public telephone line PNT via the modem 48. The computer 90 is connected to an external network via the SIO 88 and the modem 18, and by connecting to a specific server SV, can download a program required for image processing to the hard disk 76. In addition, it is also possible to load a necessary program from a flexible disk FD or a CD-ROM, and cause the computer 90 to execute the program.

FIG. 2 is a block diagram showing the configuration of software related to print processing. The computer 90 includes a CPU, RAM, ROM, and the like (not shown), and an application program 95 operates under a predetermined operating system. A video driver 91 and a printer driver 96 are incorporated in the operating system, and the final color image data FNL is output from the application program 95 via these drivers. An application program 95 for retouching an image reads an image from a scanner, performs a predetermined process on the image, and displays the image on a CRT display 93 via a video driver 91. When the application program 95 issues a print command, the printer driver 96 of the computer 90 receives the image information from the application program 95, and receives the image information from the application program 95 as a signal that can be printed by the printer 22 (here, a binary signal for each color of CMYK). Signal). In the example shown in FIG. 2, inside the printer driver 96, a rasterizer 97 that converts color image data handled by the application program 95 into image data in dot units and a printer 22 for image data in dot units are provided. A color correction module 98 that performs color correction according to the ink color CMY to be used and the characteristics of the color development, a color correction table CT that is referred to by the color correction module 98, and ink information in dot units based on the color-corrected image information. A halftone module 99 is provided for generating so-called halftone image information that expresses density in a certain area depending on the presence or absence.

FIG. 3 is a schematic configuration diagram of the printer 22. As shown in the drawing, the printer 22 includes a mechanism for transporting a sheet P by a paper feed motor 23, a mechanism for reciprocating a carriage 31 in the axial direction of a platen 26 by a carriage motor 24, and a print head mounted on the carriage 31. And a control circuit 40 for exchanging signals with the paper feed motor 23, the carriage motor 24, the print head 28 and the operation panel 32. I have.

The cartridge 31 for black ink and the cartridge 72 for color ink containing cyan, magenta, and yellow inks can be mounted on the carriage 31 of the printer 22. A total of four ink discharge heads 61 to 64 are formed on the print head 28 below the carriage 31, and at the bottom of the carriage 31, an introduction pipe 65 (for introducing ink from the ink tank to each color head). (See FIG. 4). When the black ink cartridge 71 and the color ink cartridge 72 are mounted on the carriage 31 from above, an inlet tube is inserted into a connection hole provided in each cartridge, and ink from the ink cartridge to the ejection heads 61 to 64 is inserted. Supply becomes possible.

(4) A mechanism for ejecting ink will be briefly described. As shown in FIG. 4, when the ink cartridges 71 and 72 are mounted on the carriage 31, the ink in the ink cartridge is sucked out through the introduction pipe 65 by utilizing the capillary phenomenon, and is provided below the carriage 31. The print heads 28 are guided to the respective color heads 61 to 64 of the print head 28. When the ink cartridge is mounted for the first time, an operation of sucking ink into the heads 61 to 64 of the respective colors is performed by a dedicated pump. In this embodiment, a pump for suction and a cap for covering the print head 28 at the time of suction are provided. The illustration and description of such a configuration are omitted.

As shown in FIG. 4, the heads 61 to 64 for each color are provided with 32 nozzles n for each color, and each of the nozzles is one of the electrostrictive elements and has excellent responsiveness. The element PE is arranged. FIG. 5 shows the structure of the piezo element PE and the nozzle n in detail. As shown in the drawing, the piezo element PE is installed at a position in contact with an ink passage 66 for guiding ink to the nozzle n. As is well known, the piezo element PE is an element in which the crystal structure is distorted by the application of a voltage and converts the electric-mechanical energy very quickly. In the present embodiment, by applying a voltage having a predetermined time width between the electrodes provided at both ends of the piezo element PE, the piezo element PE expands by the voltage application time as shown in the lower part of FIG. One side wall 66 is deformed. As a result, the volume of the ink passage 66 contracts in accordance with the expansion of the piezo element PE, and the ink corresponding to this contraction becomes particles Ip and is ejected from the tip of the nozzle n at high speed. Printing is performed by the permeation of the ink particles Ip into the paper P mounted on the platen 26.

In the printer 22 having the hardware configuration described above, the carriage 31 is reciprocated by the carriage motor 24 while the paper P is being conveyed by rotating the platen 26 and other rollers by the paper feed motor 23, and at the same time each color of the print head 28 The piezo elements PE of the heads 61 to 64 are driven to discharge the respective color inks, and a multicolor image is formed on the paper P. The specific arrangement of the nozzles in the heads 61 to 64 for each color will be further described later.

The mechanism for transporting the paper P includes a gear train (not shown) for transmitting the rotation of the paper feed motor 23 to not only the platen 26 but also a paper transport roller (not shown). A mechanism for reciprocating the carriage 31 includes an endless drive belt 36 stretched between a carriage shaft 24 and a slide shaft 34 laid parallel to the axis of the platen 26 and slidably holding the carriage 31. And a position detection sensor 39 for detecting the origin position of the carriage 31.

The control circuit 40 (FIG. 3) includes a programmable ROM (PROM) 42 as a rewritable nonvolatile memory in addition to a CPU and a main memory (ROM and RAMU) not shown. The PROM 42 stores dot recording mode information including a plurality of dot recording mode parameters. Here, the “dot recording mode” means a dot recording method defined by the number N of nozzles actually used in each nozzle array, the sub-scan feed amount L, and the like. In this specification, “recording method” and “recording mode” are used with almost the same meaning. Specific examples of the dot recording mode and their parameters will be described later. The PROM 42 also stores mode designation information for designating a preferred mode from a plurality of dot recording modes. For example, when 16 types of dot recording mode information can be stored in the PROM 42, the mode designation information is composed of 4-bit data.

The dot recording mode information is read from the PROM 42 by the printer driver 96 when the printer driver 96 (FIG. 2) is installed when the computer 90 is started. That is, the printer driver 96 reads from the PROM 42 the dot recording mode information for the preferred dot recording mode specified by the mode specification information. The processing in the rasterizer 97 and the halftone module 99 and the main scanning and sub-scanning operations are executed according to the dot recording mode information.

The PROM 42 may be any rewritable nonvolatile memory, and various nonvolatile memories such as an EEPROM and a flash memory can be used. Although the mode designation information is preferably stored in a rewritable nonvolatile memory, the dot recording mode information may be stored in a non-rewritable ROM. Further, the plurality of dot recording mode information may be stored in another storage unit instead of the PROM 42, or may be registered in the printer driver 96.

FIG. 6 is an explanatory diagram showing the arrangement of inkjet nozzles in the ink ejection heads 61 to 64. The first head 61 is provided with a nozzle array that ejects black ink. The second to fourth heads 62 to 64 are also provided with nozzle arrays for ejecting cyan, magenta, and yellow inks, respectively. The positions of these four sets of nozzle arrays in the sub-scanning direction coincide with each other.

The # 4 nozzle arrays each include 32 nozzles n arranged in a staggered manner at a constant nozzle pitch k along the sub-scanning direction. The 32 nozzles n included in each nozzle array need not be arranged in a staggered manner, but may be arranged on a straight line. However, the arrangement in a staggered manner as shown in FIG. 6A has the advantage that the nozzle pitch k can be easily set small in manufacturing.

FIG. 6B shows an arrangement of a plurality of dots formed by one nozzle array. In this embodiment, regardless of whether the arrangement of the ink nozzles is staggered or linear, the plurality of dots formed by one nozzle array are arranged in a substantially straight line along the sub-scanning direction. A drive signal is supplied to the piezo element PE (FIG. 5). For example, consider a case where the nozzles are arranged in a zigzag pattern as shown in FIG. 6A and the head 61 is scanned in the right direction in the figure to form dots. At this time, a driving signal is given to the preceding nozzle groups 100, 102... At a timing earlier by d / v [sec] than to the following nozzle groups 101, 103. Here, d [inch] is the pitch between the two nozzle groups in the head 61 (see FIG. 6A), and v [inch / sec] is the scanning speed of the head 61. As a result, a plurality of dots formed by one nozzle array are arranged on a straight line in the sub-scanning direction. As will be described later, not all of the 32 nozzles provided in each of the heads 61 to 64 are always used. Depending on the dot recording method, only some of the nozzles are used. In some cases.

The nozzle array in each ink ejection head shown in FIG. 6 corresponds to the dot forming element array in the present invention. Further, the feed mechanism of the carriage 31 including the carriage motor 24 shown in FIG. 3 corresponds to the main scanning drive unit in the present invention, and the paper feed mechanism including the paper feed motor 23 corresponds to the sub-scan drive unit in the present invention. . Further, a circuit including the piezo element PE of each nozzle corresponds to a head driving unit in the present invention. Further, the control circuit 40 and the printer driver 96 (FIG. 2) correspond to control means in the present invention.

B. Basic conditions of dot recording method of intermediate processing:
Before describing the dot recording method in the upper and lower end processing and the intermediate processing according to the embodiment of the present invention, first, basic conditions required for the dot recording method of the intermediate processing will be described below. The following basic conditions do not necessarily need to be applied to the upper end processing and the lower end processing, but may be applied to the upper end processing and the lower end processing.

FIG. 7 is an explanatory diagram showing basic conditions of a general dot recording method when the number of scan repetitions s is 1. FIG. 7A shows an example of sub-scan feed when four nozzles are used, and FIG. 7B shows parameters of the dot recording method. In FIG. 7A, solid circles including numbers indicate the positions in the sub-scanning direction of the four nozzles after each sub-scan feed. Numbers 1 to 4 in the circles mean nozzle numbers. The positions of the four nozzles are sent in the sub-scanning direction each time one main scan is completed. However, actually, the feed in the sub-scanning direction is realized by moving the paper by the paper feed motor 23 (FIG. 3).

As shown in the left end of FIG. 7A, in this example, the sub-scan feed amount L is a constant value of 4 dots. Therefore, each time the sub-scan feed is performed, the positions of the four nozzles shift by four dots in the sub-scan direction. When the number of scan repetitions s is 1, each nozzle can record all dots (also referred to as “pixels”) on each raster. At the right end of FIG. 7A, nozzle numbers for recording dots on each raster are shown.

When the recording mode shown in FIG. 7 is adopted from the beginning without performing the upper end processing as described later, a dotted line extending rightward (main scanning direction) from a circle indicating the position of the nozzle in the sub-scanning direction. In the drawn raster, at least one of the upper and lower rasters cannot be recorded. Therefore, dot recording is actually prohibited in these rasters. On the other hand, a raster drawn by a solid line extending in the main scanning direction is in a range where both rasters before and after the raster can be recorded by dots. The range in which dots can be recorded in this manner is hereinafter referred to as a “printable area” (or “recordable area”). The range in which dot printing is actually performed is referred to as “print execution area” (or “print execution area”). The print execution area may be set smaller than the printable area, or may be set equal to the printable area. The printable area is extended by upper end processing and lower end processing described later. A range other than the printable area on the paper is referred to as a “print-disabled area” (or “non-recordable area”). ). Further, the entire area where the nozzle is scanned (including the print execution area and the non-print area) is referred to as a nozzle scan area.

FIG. 7B shows various parameters relating to the dot recording method. The parameters of the dot recording method include the nozzle pitch k [dot], the number of used nozzles N [number], the number of scan repetitions s, the effective nozzle number Neff [number], and the sub-scan feed amount L [dot]. include.

で は In the example of FIG. 7, the nozzle pitch k is 3 dots. The number N of used nozzles is four. The number of used nozzles N is the number of nozzles actually used among a plurality of mounted nozzles. The number of scan repetitions s means that dots are formed intermittently every (s-1) dots in one main scan. Therefore, the number of scan repetitions s is also equal to the number of nozzles used to record all dots on each raster. In the case of FIG. 7, the number of scan repetitions s is one. The effective nozzle number Neff is a value obtained by dividing the used nozzle number N by the number of scan repetitions s. This effective nozzle number Neff can be considered to indicate the net number of rasters that can be printed in one main scan. The meaning of the effective nozzle number Neff will be further described later.

テ ー ブ ル The table shown in FIG. 7B shows, for each sub-scan feed, the sub-scan feed amount L, its cumulative value ΔL, and the nozzle offset F after each sub-scan feed. Here, the offset F refers to the periodic position of the first nozzle in which the sub-scan feed is not performed (the position every four dots in FIG. 7) as the reference position of the offset 0, and This value indicates how many dots the nozzle position is apart from the reference position in the sub-scanning direction. For example, as shown in FIG. 7A, the nozzle position moves in the sub-scanning direction by the sub-scanning feed amount L (4 dots) by the first sub-scan feed. On the other hand, the nozzle pitch k is 3 dots. Therefore, the nozzle offset F after the first sub-scan feed is 1 (see FIG. 7A). Similarly, the nozzle position after the second sub-scan feed has moved by ΔL = 8 dots from the initial position, and the offset F thereof is 2. The nozzle position after the third sub-scan feed has moved by ΔL = 12 dots from the initial position, and its offset F is zero. Since the nozzle offset F returns to 0 by the three sub-scan feeds, all the dots on the raster within the printable area can be recorded by repeating the three sub-scans as one cycle. it can.

解 As can be seen from the above example, when the nozzle position is located at a position away from the initial position by an integral multiple of the nozzle pitch k, the offset F is zero. The offset F is given by a remainder (ΔL)% k obtained by dividing the cumulative value ΔL of the sub-scan feed amount L by the nozzle pitch k. Here, “%” is an operator indicating that the remainder of the division is taken. If the initial position of the nozzle is considered to be a periodic position, the offset F can be considered to indicate the amount of phase shift from the initial position of the nozzle.

(4) When the number of scan repetitions s is 1, the following conditions must be satisfied in order to prevent raster omission or overlap in the printable area.

Condition c1: The number of sub-scan feeds per cycle is equal to the nozzle pitch k.

Condition c2: The nozzle offset F after each sub-scan feed in one cycle takes a different value in the range of 0 to (k-1).

Condition c3: The average amount of sub-scan feed (ΣL / k) is equal to the number N of used nozzles. In other words, the total value ΔL of the sub-scan feed amount L per cycle is equal to a value (N × k) obtained by multiplying the number N of used nozzles by the nozzle pitch k.

各 The above conditions can be understood by thinking as follows. Since there are (k-1) rasters between adjacent nozzles, printing is performed on these (k-1) rasters in one cycle, and the nozzle is positioned at the reference position (position where offset F is zero). In order to return to, the number of sub-scan feeds in one cycle is k. If the number of sub-scan feeds in one cycle is less than k times, a missing raster occurs in the recorded raster, while if the number of sub-scan feeds in one cycle is more than k times, the recorded rasters overlap. Therefore, the above first condition c1 is satisfied.

When the number of sub-scan feeds in one cycle is k, only when the value of the offset F after each sub-scan feed is a different value in the range of 0 to (k-1), the raster to be recorded is missing or overlapping. Disappears. Therefore, the above second condition c2 is satisfied.

(4) If the above first and second conditions are satisfied, each of the N nozzles prints k rasters in one cycle. Therefore, N × k rasters are recorded in one cycle. On the other hand, if the above third condition c3 is satisfied, as shown in FIG. 7A, the position of the nozzle after one cycle (after k times of sub-scan feed) becomes N × k from the initial nozzle position. It comes to a position away from the raster. Therefore, by satisfying the first to third conditions c1 to c3, it is possible to eliminate omissions and duplications in the rasters to be recorded in the range of these N × k rasters.

FIG. 8 is an explanatory diagram showing basic conditions of a general dot recording method when the number of scan repetitions s is 2 or more. When the number of scan repetitions s is 2 or more, the same raster is recorded by s different nozzles. Hereinafter, a dot recording method in which the number of scan repetitions s is 2 or more is called an "overlap method".

The dot recording method shown in FIG. 8 is obtained by changing the number of scan repetitions s and the sub-scan feed amount L in the parameters of the dot recording method shown in FIG. 7B. As can be seen from FIG. 8A, the sub-scan feed amount L in the dot recording method of FIG. 8 is a constant value of 2 dots. However, in FIG. 8A, the positions of the nozzles after the odd-numbered sub-scan feeds are indicated by diamonds. As shown at the right end of FIG. 8A, the dot position recorded after the odd-numbered sub-scan feed is the same as the dot position recorded after the even-numbered sub-scan feed and one dot in the main scanning direction. It is out of alignment. Therefore, a plurality of dots on the same raster are intermittently recorded by two different nozzles. For example, the uppermost raster in the printable area is intermittently recorded every other dot by the third nozzle after the first sub-scan feed, and then is output by the first nozzle after the fourth sub-scan feed. It is recorded intermittently every dot. In general, in the overlap method, the nozzles are driven at intermittent timings so that (s-1) dot printing is prohibited after printing one dot during one main scan.

In the overlap method, since the positions of a plurality of nozzles that print the same raster in the main scanning direction need only be shifted from each other, the actual shift amount in the main scanning direction during each main scan is shown in FIG. Various things other than those shown in FIG. For example, after the first sub-scan feed, the dot at the position indicated by the circle is recorded without shifting in the main scanning direction, and after the fourth sub-scan feed, the dot is shifted in the main scan direction to indicate the position indicated by the diamond. Can also be recorded.

When the number of scan repetitions s is 2 or more, the sub-scan feed of a small cycle is repeatedly applied at the time of dot recording, so the small cycle is also referred to as a "unit cycle". In this sense, when the number of scan repetitions s is 1, one cycle of the sub-scan feed can be called a “unit cycle”.

The value of the offset F after each sub-scan in one cycle is shown at the bottom of the table in FIG. 8B. One cycle includes six sub-scan feeds, and the offset F after each of the first to sixth sub-scan feeds includes a value in the range of 0 to 2 twice. The change of the offset F after the first to third sub-scan feeds is equal to the change of the offset F after the fourth to sixth sub-scan feeds. As shown in the left end of FIG. 8A, six sub-scan feeds in one cycle can be divided into two sets of three small cycles. At this time, one cycle of the sub-scan feed is completed by repeating the small cycle s times.

Generally, when the number of scan repetitions s is an integer of 2 or more, the above first to third conditions c1 to c3 are rewritten as the following conditions c1 'to c3'.

Condition c1 ’: The number of sub-scan feeds in one cycle is equal to the value (k × s) obtained by multiplying the nozzle pitch k by the number of scan repetitions s.

'Condition c2': The nozzle offset F after each sub-scan feed in one cycle is a value in the range of 0 to (k-1), and each value is repeated s times.

{Condition c3}: The average sub-scan feed amount {L / (k × s)} is equal to the effective nozzle number Neff (= N / s). In other words, the cumulative value {L of the sub-scan feed amount L per cycle is equal to the value {Neff × (k × s)} obtained by multiplying the effective nozzle number Neff by the number of sub-scan feeds (k × s).

条件 The above conditions c1 'to c3' hold even when the number of scan repetitions s is one. Accordingly, the conditions c1 'to c3' are conditions generally satisfied for the dot recording method regardless of the value of the number of scan repetitions s. That is, if the above three conditions c1 'to c3' are satisfied, it is possible to prevent the recorded dots from missing or overlapping in the printable area. However, when the overlap method (when the number of scan repetitions s is 2 or more) is adopted, a condition that the recording positions of the nozzles that record the same raster are shifted from each other in the main scanning direction is also necessary.

Depending on the recording method, partial overlap may occur. “Partial overlap” refers to a recording method in which raster data recorded by one nozzle and raster data recorded by a plurality of nozzles are mixed. Even in the printing method using such partial overlap, the effective nozzle number Neff can be defined. For example, of the four nozzles, two nozzles cooperate to print the same raster, and the remaining two nozzles each print one raster, in a partial overlap method, The number of effective nozzles Neff is three. Also in the case of such a partial overlap method, the above three conditions c1 'to c3' are satisfied.

The effective nozzle number Neff can be considered to indicate the net number of rasters that can be recorded in one main scan. For example, when the number of scan repetitions s is 2, raster lines of the same number as the number N of nozzles can be printed in two main scans, so that the net of rasters that can be printed in one main scan is used. Is equal to N / s (ie, Neff). The effective nozzle number Neff in the embodiment corresponds to the effective dot forming element number in the present invention.

C. Example of intermediate processing:
FIGS. 9A and 9B are explanatory diagrams showing a dot recording method in the intermediate processing according to the embodiment of the present invention. The scanning parameters of this dot recording method are as shown at the lower left of FIG. 9A, where the nozzle pitch k is 4 dots, the number of used nozzles N is 8, the number of scan repetitions s is 2, and the effective number of nozzles Neff is 4. is there.

In FIG. 9A, nozzle numbers # 1 to # 8 are assigned to eight used nozzles in order from the top. In the dot recording method in the intermediate processing, one small cycle is constituted by four sub-scan feeds, and one cycle is constituted by two small cycles. The sub-scan feed amount L in each small cycle is 5, 2, 3, 6 dots. That is, a plurality of different values are used as the sub-scan feed amount L. The positions of the eight nozzles in each sub-scan feed are shown by four different figures. A sub-scan feed in which a combination of a plurality of different feed amounts is used as in this example is referred to as “irregular feed”.

(4) When the upper end processing described below is not performed, a non-printable area for 23 rasters exists before the printable area. That is, the printable area starts from the 24th raster from the upper end of the nozzle scanning range (the range including the printable area and the non-printable area).

テ ー ブ ル The table of FIG. 9B shows the sub-scan feed amount L, the cumulative value ΔL thereof, and the nozzle offset F after each sub-scan feed for each sub-scan feed. The parameters shown in FIG. 9B satisfy the above three conditions c1 'to c3'. That is, the number of sub-scan feeds in one cycle is equal to a value (k × s = 8) obtained by multiplying the nozzle pitch k (= 4) and the number of scan repetitions s (= 2) (first condition c1 ′). The nozzle offset F after each sub-scan feed in one cycle is a value in the range of 0 to (k-1) (that is, 0 to 3) (second condition c2 '). The average feed amount (ΣL / k) of the sub-scan feed is equal to the effective nozzle number Neff (= 4) (third condition c3 ′). Therefore, the dot recording method of the intermediate processing satisfies the basic requirement that there is no missing or overlapping of the recorded raster in the printable area.

ド ッ ト The dot recording method of the intermediate processing further has the following two features. A first feature is that the nozzle pitch k and the number N of used nozzles are non-prime integers of 2 or more. A second feature is that “a plurality of different values are used as the sub-scan feed amount L”. In many conventional dot recording methods, the number N of nozzles and the nozzle pitch k are selected as integers having a prime relationship with each other. Therefore, even if a large number of nozzles are mounted, the number N of nozzles that can be actually used is limited to a number that is relatively prime to the nozzle pitch k. In other words, conventionally, there is a problem that the mounted nozzles cannot be used sufficiently in many cases. On the other hand, if the dot recording method having the first feature that “the nozzle pitch k and the number of used nozzles N are non-prime and are integers of 2 or more” is allowed, the mounted nozzles can be used. There is an advantage that a dot recording method that uses as many as possible can be easily adopted. The second feature is to satisfy the basic requirement that "there is no missing or overlapped raster to be recorded in the printable area" even when the first feature is adopted. It is. In a dot recording method having the above-described first feature and having the sub-scan feed amount L at a fixed value, a dropout occurs in the raster or an overlap occurs.

However, as the dot recording method of the intermediate processing, it is also possible to adopt an irregular feeding that does not have the first feature. That is, as the nozzle pitch k and the number N of nozzles to be used, it is also possible to select an integer having a relatively prime relationship.

FIG. 10 is an explanatory diagram showing which nozzle is used to print each raster in the irregular feed dot printing method shown in FIG. 9A. The numbers 1 to 8 in the small square frame indicate the nozzle numbers. In the printable area, each raster along the main scanning direction is recorded by two nozzles. For example, the raster at the uppermost end of the printable area is recorded by the fifth nozzle and the first nozzle. At this time, the fifth nozzle records, for example, an even-addressed pixel, and the first nozzle records an odd-addressed pixel.

FIGS. 11A and 11B are explanatory diagrams showing a comparison between sub-scanning with a constant feed amount and sub-scanning with irregular feeding. In FIGS. 11A and 11B, for example, “first scan” indicates a raster recorded in the first main scan, and “second scan” performs one sub-scan. Shows the raster recorded in the second main scan after the printing. As shown in FIG. 11A, when the sub-scan feed amount is constant, a raster adjacent to a raster to be printed in the previous scan is always to be printed in the next scan. On the other hand, if the irregular feed is performed as shown in FIG. 11B, a raster that is not adjacent to the raster to be recorded in the previous scan will be used in the next scan, as in the examples of the second and third scans. May be recorded. As shown in FIG. 11A, when always adjacent rasters are to be recorded, the following two problems occur. The first problem is that bleeding easily occurs between dots. The second problem is that mechanical sub-scanning feed errors gradually accumulate, and a large positional shift occurs between two adjacent rasters. Both of these two problems cause image quality to deteriorate. These problems can be avoided by using the irregular feeding, and as a result, the image quality can be improved.

In the meantime, as the intermediate processing, a dot recording method in which the sub-scan feed amount is constant may be employed, but from the viewpoint of improving the image quality, it is preferable to employ the irregular feed.

第 The first to third embodiments described below are classified into two groups. The first embodiment is an embodiment in which only one specific sub-scan feed pattern is used in the upper end processing, and one of a plurality of sub-scan feed patterns is selected in the lower end processing. This first embodiment is referred to as “an embodiment in which adjustment is performed by lower end processing”. In the second and third embodiments, in contrast to the first embodiment, only one specific sub-scan feed pattern is used in the lower end processing, and one of a plurality of sub-scan feed patterns is selected in the upper end processing. This is an example of such an operation. These second and third embodiments will be referred to as “embodiments for performing adjustment by upper end processing”. Hereinafter, these three embodiments will be sequentially described.

D. First embodiment (an embodiment in which adjustment is performed by lower end processing):
D-1. Example of upper end processing when adjusting by lower end processing:
FIG. 12 is an explanatory diagram illustrating an example of the upper end process used when performing the adjustment by the lower end process. In this example, three-dot feeding is repeated seven times as upper end processing, and thereafter, the processing shifts to irregular feeding of intermediate processing. Also in the upper end processing, the number of scan repetitions is 2, as in the intermediate processing, and one raster is printed by two main scans. As a result of this upper end processing, the non-printable area is reduced from 23 rasters (FIG. 10) to 18 rasters (FIG. 12), and the printable area is extended by 5 rasters.

In the dot recording method of the upper end processing, the recordable rasters and dots may overlap, and therefore, it is not necessary to satisfy the above-described conditions c1 'to c3'. Actually, the dot recording method of the upper end processing shown in FIG. 12 does not satisfy these conditions.

{Circle around (1)} As the upper end processing, one-dot feed (fine feed) may be employed, and the number of scan repetitions may be one. However, from the viewpoint of improving the image quality, it is preferable to set the sub-scanning feed amount to a plurality of dots, and it is preferable to make the number of scan repetitions of the upper end processing and the intermediate processing equal. It is not always necessary to perform the upper end processing, and the same dot recording mode as in the intermediate processing may be used from the upper end of the printable area.

D-2. Example of adjustment by lower edge processing:
FIG. 13 and FIG. 14 are explanatory diagrams showing a state of recording near the lower end of the printable area when the lower end processing is not performed. Although FIG. 14 shows a raster following FIG. 13, for convenience of illustration, the same raster as the one raster at the upper end of FIG. 14 is displayed at the lower end of FIG. This is the same in other drawings described later. In FIGS. 13 and 14, “n + 1-th feed” means the (n + 1) -th sub-scan in the intermediate processing. That is, it means that the sub-scan feed has been performed n times before FIGS. However, the value of n is not important.

下端 As shown in FIG. 14, there is a lower end position where the paper cannot be mechanically fed near the lower end of the paper. In other words, the eighth nozzle at the lower end of the recording head cannot go below this “lower end position where paper cannot be fed mechanically”. As shown by a broken line in FIG. 14, if the (n + 11) th three-dot sub-scan feed is performed, the eighth nozzle at the lower end protrudes below the “lower end position where the paper cannot be mechanically fed”. I will. Therefore, the sub-scan feed can be actually performed up to the (n + 10) th feed. In the scan up to the (n + 10) th sub-scan feed, the line immediately below the line marked "the lower end line of the printable area" has been subjected to only one main scan, and cannot be scanned twice. Therefore, it becomes an unprintable area.

FIGS. 15 and 16 are explanatory diagrams showing a case where the lower end processing is performed. Up to the (n + 4) th sub-scan feed shown in FIGS. 15 and 16, the operation is the same as in the case without the lower end processing shown in FIGS. 13 and 14. In the examples of FIGS. 15 and 16, the (n + 5) th sub-scan feed for 5 dots is changed to the transient feed for 1 dot, and dot printing for one main scan is performed. After the excessive feeding, the lower end processing is executed by the dot recording method in which the sub-scanning feeding at a constant 3 dots is repeated eight times. As a result, as shown in FIG. 16, the lower end of the printable area is extended by 10 rasters.

In the dot recording method of the lower end processing, recordable rasters and dots may overlap, and therefore, it is not necessary to satisfy the above-described conditions c1 'to c3'. Actually, the dot recording method of the lower end processing shown in FIGS. 15 and 16 does not satisfy these conditions.

FIGS. 17 and 18 are explanatory diagrams showing the lower end processing example 1 of the first embodiment. The dot recording method in FIGS. 17 and 18 is the same as that shown in FIGS. 15 and 16, and as shown in FIG. 18, the position of the lower end line of the print execution area is higher than the lower end line of the printable area. 15 and FIG. 16 only in that The reason for this is that the position of the lower end line of the print execution area on the sheet is determined according to the sheet setting of the printer driver or the page setting of the application program. That is, the position of the lower end line of the print execution area is determined according to the paper setting and the page setting, and the dot recording method of the lower end processing is determined so that the printable area includes the lower end line.

In the example of FIG. 18, whether to change the sub-scan feed for five dots to the transient feed for one dot is determined as follows. That is, when the nozzle at the lower end of the print head reaches a position subsequent to the lower end line of the print execution area when performing the sub-scan feed for 5 dots by the irregular feed of the intermediate processing, the sub-scan feed for 5 dots is performed. Is determined to be changed to the transient feed for one dot. Here, "when the lower end nozzle reaches the position after the lower end line of the print execution area" means that the lower end nozzle reaches the position of the lower end line of the print execution area or exceeds the position of the lower end line. means. If the sub-scanning feed amount when the lower end nozzle reaches the position after the lower end line of the print execution area is not 5 dots, determination as described in another lower end processing example described later is performed.

FIG. 18 shows the range of the lower end line where it is determined that the 5-dot feed should be changed to the 1-dot transient feed. That is, when the lower end line of the print execution area exists within the range of the five rasters, the nozzle at the lower end reaches the position after the lower end line of the print execution area when performing the sub-scan feed of 5 dots. It is determined that the sub-scan feed for 5 dots should be changed to the transient feed for 1 dot. During the main scanning after the transient feed, the uppermost nozzle is positioned on the already recorded raster, and is not used for actual printing.

In the lower end process, not only is it determined whether or not to perform the transient feed, but also the dot position to be printed by each nozzle during each main scan in the lower end process. For example, in the main scan after the transient feed for one dot shown in FIG. 17, the raster scanned by the first nozzle at the upper end is already recorded using the eighth nozzle and the fourth nozzle in the intermediate processing. Completed. Therefore, the first nozzle does not record dots. Further, in the raster scanned by the second nozzle, printing is performed only every other dot by the fifth nozzle in the intermediate processing, so that printing of the remaining dot positions is executed by the second nozzle. Even after the lower end processing of the three-dot feed, the dot position recorded by each nozzle at the time of main scanning is similarly adjusted based on the previous dot recording history.

(4) In the above-described lower end processing, a fixed feed amount of 3 dots is used, but in general, a feed amount for a plurality of dots can be adopted. The reason why the feed amount for a plurality of dots is adopted is to improve the image quality. That is, in the one-dot feed (fine feed), mechanical sub-scanning feed errors are accumulated, and the possibility of deteriorating the image quality is considerably large. If a feed amount of a plurality of dots is adopted, this problem can be mitigated. is there. From the viewpoint of improving the image quality, it is preferable that the number of scan repetitions in the lower end processing and the intermediate processing be equal.

FIGS. 19 and 20 are explanatory diagrams showing a lower end processing example 2 of the first embodiment. Up to the (n + 5) th sub-scan feed shown in FIGS. 19 and 20, the operation is the same as in the case without the lower end processing shown in FIGS. In the examples of FIGS. 19 and 20, the (n + 6) -th sub-scan feed for two dots is maintained as it is, and thereafter, the process shifts to the lower end processing by the constant three-dot sub-scan feed. In the lower end processing example 2, the (n + 6) th sub-scan feed can be considered to be “transient feed”, and the transition from intermediate processing to lower end processing immediately without performing transient feed can be considered. It is possible.

In the lower end processing example 2, the determination that the process shifts to the lower end processing immediately after the (n + 6) th sub-scan feed is performed as follows. That is, if the lower nozzle of the print head reaches a position after the lower line of the print execution area when performing the sub-scan feed for two dots in the irregular feed of the intermediate processing, the sub-scan feed for two dots is performed. Is performed as it is, and thereafter, it is determined that the lower end processing is executed. Note that FIG. 20 shows the range of the lower end line where it is determined that the lower end processing should be started immediately after the feeding of two dots. That is, when the lower end line of the print execution area exists within the range of the two rasters, the nozzle at the lower end reaches the position after the lower end line of the print execution area when performing the sub-scan feed of two dots. , It is determined that the lower end process should be started after the two-dot feed.

Also in the lower end processing example 2, the dot position to be printed by each nozzle in each main scan of the lower end processing is determined based on the dot recording history in the intermediate processing. For example, the raster at the lower end in FIG. 19 is scanned by the first nozzle in the second main scan of the lower end processing. However, printing of this raster has already been completed using the seventh nozzle and the third nozzle in the intermediate processing. Therefore, the first nozzle does not record dots in this raster. Also in FIG. 20, in a raster in which three or more nozzles are positioned, recording by the third nozzle is prohibited. On the other hand, in a raster in which dot positions not recorded in the intermediate processing exist, the remaining dot positions are recorded by the lower end processing.

FIGS. 21 and 22 are explanatory diagrams showing a lower end processing example 3 of the first embodiment. Up to the (n + 6) th sub-scan feed shown in FIGS. 21 and 22, this is the same as the case without the lower end processing shown in FIGS. 13 and 14. In FIG. 21 and FIG. 22, the (n + 7) th sub-scan feed for three dots is maintained as it is, and thereafter, the processing shifts to the lower end processing by the constant three-dot sub-scan feed. In the lower end processing example 3, similarly to the lower end processing example 2, the (n + 7) th sub-scan feed can be considered to be “transient feed”, and the process immediately shifts from intermediate processing to lower end processing without performing transient feed. It is possible to think that it is doing.

(4) In the lower end processing example 3, the determination that the process shifts to the lower end processing immediately after the (n + 7) th sub-scan feed is performed as follows. That is, if the lower nozzle of the print head reaches a position after the lower line of the print execution area when the sub-scan feed for three dots is performed in the irregular feed of the intermediate processing, the sub-scan feed for three dots is left as it is. It is determined that the lower end process is performed after that. FIG. 22 shows the range of the lower end line where it is determined that the lower end processing should be started immediately after the feeding of three dots. That is, when the lower end line of the print execution area exists within the range of three rasters, the nozzle at the lower end reaches the position after the lower end line of the print execution area when performing the sub-scan feed of three dots. , It is determined that the lower end processing should be started after the three-dot feed.

Also in the lower end process 3, the dot position to be printed by each nozzle in each main scan of the lower end process is determined based on the dot recording history in the intermediate process, but the description is omitted.

FIGS. 23 and 24 are explanatory diagrams showing a lower end processing example 4 of the first embodiment. Up to the (n + 7) -th sub-scan feed shown in FIGS. 23 and 24, the operation is the same as the case without the lower end processing shown in FIGS. 13 and 14. In FIGS. 23 and 24, the (n + 8) th sub-scan feed for 6 dots is changed to the transient feed for 3 dots, and thereafter, the process shifts to the lower end process by constant sub-scan feed.

In the lower end processing example 4, whether or not to change the sub-scan feed for 6 dots to the transient feed for 3 dots is determined as follows. That is, if the lower nozzle of the print head reaches a position after the lower end line of the print execution area when performing the sub-scan feed of 6 dots in the irregular feed of the intermediate processing, the sub-scan feed of 6 dots is performed by 3 dots. It is determined that it is necessary to change to the transient feed for the dot. FIG. 24 shows the range of the lower end line where it is determined that the sub-scan feed for six dots should be changed to the transient feed for three dots. In other words, if the lower end line of the print execution area exists within the range of the six rasters, the lower end nozzle reaches the position after the lower end line of the print execution area when performing the sub-scan feed for six dots. , The sub-scan feed for 6 dots should be changed to the transient feed for 3 dots.

In the lower end processing example 4 as well, the dot position to be recorded by each nozzle in each main scan of the lower end processing is determined based on the dot recording history in the main scan of the intermediate processing and the transient feed. Is omitted.

In the lower end processing examples 1 to 4 described above, whether or not transient feed is necessary is determined based on only the value of the sub-scan feed amount when the lower end nozzle reaches a position after the lower end line of the print execution area. It seems that the feed amount has been determined. However, in practice, whether or not the transient feed is necessary and the feed amount depend on the history of a plurality of sub-scan feed amounts up to the position of the lower end line of the print execution area. Therefore, even if the value of the sub-scan feed amount when the lower end nozzle reaches the position after the lower end line of the print execution area is the same, if the recording mode in the intermediate processing is different (that is, the history of the sub-scan feed amount is If they are different), the result of the determination as to whether the transient feed is necessary and the feed amount will be different.

The lower end processing examples 1 to 4 described above can be generated by paper setting or page setting even in the same printer employing the same intermediate processing. Therefore, the printer driver determines which of the above-described lower end processing examples 1 to 4 is applicable, and executes the transition from the intermediate processing to the lower end processing accordingly.

FIG. 25 is an explanatory diagram showing the state of sub-scan feed over substantially the entire print execution area. In FIG. 25, in the intermediate processing, the sub-scan feed of m unit cycles has been completed. The symbol Vres indicates the number of raster lines that are located below the lower end nozzle # 8 in the print execution area and have not yet been recorded. These Vres rasters are recorded by lower end processing. Here, it is assumed that one unit cycle is composed of 5, 2, 3, and 6 dots (FIG. 9). At the start of the intermediate processing, the upper end nozzle # 1 of the recording head 28 is located at a position ΔL below the upper end of the print execution area.

The remaining number of rasters Vres is given by the following equation (1).
Vres = {(Lp−ΔL−Ln)%} (1)

Here, ε is the allowable range of the positional relationship between the lower end nozzle and the lower end line of the print execution area at the end of the intermediate processing, Lp is the length of the print execution area in the sub-scanning direction, and Ln is the upper end nozzle # 1 and the lower end nozzle # Σ indicates the total value of the sub-scan feed amounts for one unit cycle in the intermediate processing, and the operator “%” indicates an operation for taking the remainder of the division. As described above, ΔL is the length from the upper end of the print execution area (which is equal to the upper end of the printable area) to the upper end of the area where the recording operation in the intermediate processing is performed. Note that all the values in the above equation (1) are expressed in units of [dots] (that is, units of the number of raster lines).

The lower end processing examples 1 to 4 described above are selected as follows according to the value of Vres.
When 1 ≦ Vres <6: Example 1 of lower end processing (FIGS. 17 and 18).
When 6 ≦ Vres <8: Example 2 of lower end processing (FIGS. 19 and 20).
When 8 ≦ Vres <11: Example 3 of lower end processing (FIGS. 21 and 22).
11 ≦ Vres <17: Example 4 of lower end processing (FIGS. 23 and 24).
Note that Vres and (Vres-16) are equivalent.

In the above-described first embodiment, when shifting from the intermediate processing to the lower end processing, the sub scanning feed of the intermediate processing and the sub scanning of the lower end processing are performed based on the history of the sub scanning feed up to the vicinity of the lower end of the print execution area. It is determined whether a sub-scan feed with a transient feed amount is necessary between the feed and the feed. If necessary, the sub-scan feed is performed with a transient feed amount, and then the process proceeds to the lower end process. In addition, the dot recording position in the transient feed and the lower end processing is determined based on the dot recording history up to that point. As a result, even when the sub-scan feed for a plurality of dots is employed in the lower end processing, it is possible to smoothly shift from the intermediate processing to the lower end processing. In particular, even when the irregular feed is adopted in the intermediate processing, it is possible to smoothly shift from the intermediate processing to the lower end processing.

In the first embodiment, the "transient feed" is defined as the sub-scan feed performed between the intermediate processing and the lower end processing. However, the "transient feed" is a part of the lower end processing. (That is, the sub-scan feed performed at the start of the lower end process). The present invention mainly uses the definition that "transient feed" is also a part of lower end processing.

As the upper end processing used in the first embodiment, one type of sub-scanning feed pattern shown in FIG. 12 can be commonly used. In other words, in the first embodiment, a plurality of sub-scanning processes are performed for the lower end process in accordance with the length of the print execution area so that one predetermined type of sub-scan feed pattern can be used for the upper end process. It can be considered that one is selected from the feed patterns (lower end processing examples 1 to 4).

E. FIG. Second Embodiment (Embodiment for Adjusting by Upper Edge Processing):
In the second embodiment, contrary to the above-described first embodiment, a predetermined type of sub-scanning feed pattern is used for the lower end process, and a plurality of sub-scanning feed patterns are used for the upper end process. Select one from It is assumed that the lower end processing uses the lower end processing example 4 shown in FIGS. 23 and 24, and that the intermediate processing uses the one shown in FIGS. 9 and 10.

FIG. 26 is an explanatory diagram showing an upper end processing example 1 of the second embodiment. The dot recording method in FIG. 26 is the same as the method shown in FIGS. 15 and 16 (the method used in the first embodiment).

FIG. 27 is an explanatory diagram showing a recording pattern of the upper end processing example shown in FIG. The upper part shows the range of the upper end processing, and the lower part shows the range of the intermediate processing. The rows of nozzle numbers # 1 to # 8 indicate the number of rasters in the printable area where each nozzle records after each sub-scan feed, where "n / a" is the record. Is not performed. For example, nozzle # 1 performs no printing from the first main scan to the main scan after the fifth sub-scan feed (ie, the sixth main scan), and performs the first main scan after the sixth sub-scan feed. The raster is recorded. The row of “feed” indicates the feed amount [dot] in each sub-scan feed, and the row of “odd / even” indicates which of the odd position and the even position on the raster is to be recorded.

解 As can be seen from this table, the print position of each nozzle in the upper end process is adjusted so that all nozzles can always execute printing in the intermediate process. In this case, since the recording operation in the area recorded in the intermediate processing is stabilized, there is an advantage that the image quality in the area is also stabilized.

In the upper end processing example 1 shown in FIGS. 26 and 27, the sub-scan feed is repeated seven times at a fixed feed amount of three dots (three rasters), and then the process proceeds to the intermediate process. In the intermediate processing, a sub-scanning feed pattern in which a combination of (5 + 2 + 3 + 6) dots is one unit cycle is repeated a plurality of times (FIG. 9).

図 FIG. 25 described above can be similarly applied to the upper end processing example 1 of the second embodiment shown in FIGS. 26 and 27. In the example of FIG. 26, ΔL = 3. The “region where the printing operation in the intermediate process is performed” is recorded in the main scan immediately before the sub-scan feed of the intermediate process is started (in FIG. 25, the main scan immediately before the first 5-dot feed). From the uppermost raster to the lowermost raster recorded in the main scan after the last sub-scan feed of the intermediate processing is performed.

In the second embodiment, the lower-end processing example 4 shown in FIGS. 23 and 24 is adjusted by adjusting the number of times of sub-scan feed in the upper-end processing according to the value Vres given by the above equation (1). Always available.
When 11 ≦ Vres <17: Example 1 of upper end processing (FIGS. 26 and 27).
When 17 ≦ Vres <20 (that is, when 1 ≦ Vres <4): Three dot feed is added once to the upper end processing example 1.
In the case of 20 ≦ Vres <23 (that is, in the case of 4 ≦ Vres <7): 3 dots feed is added twice to the upper end processing example 1.
In the case of 23 ≦ Vres <26 (that is, in the case of 7 ≦ Vres <10): 3-dot feed is added to the upper end processing example 1 three times.
When Vres = 26 (that is, when Vres = 10): Three-dot feed is added four times to the upper end processing example 1.
Note that Vres and (Vres−16) are equivalent.

FIG. 28 is an explanatory diagram showing an upper end processing example 2 in which 3-dot sub-scan feed is added three times to the upper end processing example 1 of the second embodiment when 7 ≦ Vres <10. In FIG. 28, “minimum upper end processing” means upper end processing example 1 of the second embodiment. FIG. 29 shows a recording pattern of the upper end processing example 2. In the upper end processing example 2, as in the upper end processing example 1, the printing position in the upper end processing is adjusted so that all the nozzles can execute printing in the intermediate processing.

As can be seen by comparing FIG. 25 and FIG. 28, the start position of the printable area does not change, and the position to shift to the intermediate processing moves downward by the added sub-scan feed distance (3 dots × 3). ing. As a result, even when 7 ≦ Vres <10, the lower end processing example 4 shown in FIGS. 23 and 24 can be used at the lower end of the print execution area.

F. Third embodiment (another embodiment that performs adjustment by upper end processing):
FIG. 30 is an explanatory diagram illustrating an upper end processing example 1 of the third embodiment. In the upper-end processing example 1, the one-dot sub-scan feed (that is, “small feed”) is repeated seven times, and thereafter, the process proceeds to the intermediate process. FIG. 31 is an explanatory diagram illustrating a recording pattern of the upper end processing example 1 of the third embodiment. Also in the upper end processing example 1 of the third embodiment, the printing position in the upper end processing is adjusted so that all the nozzles can execute printing in the intermediate processing. In the third embodiment, it is assumed that the same intermediate processing and lower end processing as in the second embodiment are used.

上端 The upper end processing example 1 of the third embodiment has an advantage that the printable area can be expanded as compared with the upper end processing example 1 of the second embodiment shown in FIG. However, the number of sub-scan feeds in the upper end processing is smaller in the upper end processing example 1 of the second embodiment than in the upper end processing example 1 of the third embodiment.

In the third embodiment, the sub-scan feed for the upper end processing is added as described below.

If 11 ≦ Vres <17: Example 1 of upper end processing (FIGS. 30 and 31).

場合 1 ≦ Vres <11: Add 1 dot feed Vres times to the upper end processing example 1.

FIG. 32 is an explanatory diagram showing an upper end processing example 2 in which one-dot sub-scan feed is added six times to the upper end processing example 1 of the third embodiment. In FIG. 32, “minimum upper end processing” means upper end processing example 1 of the third embodiment. FIG. 33 shows a recording pattern of the upper end processing example 2.

As described above, in the second and third embodiments, by adjusting the number of sub-scan feeds in the upper end processing according to the value of the value Vres given by the above equation (1b), a predetermined sub scanning in the lower end processing is performed. A scanning feed pattern can be used. As a result, there is an advantage that the sub-scan feed pattern of the lower end processing can be simplified.

In the second and third embodiments, the lower end processing example 4 shown in FIGS. 23 and 24 is used as the lower end processing. However, other lower end processing examples (for example, the lower end processing shown in FIGS. 17 to 22) are used. Examples 1 to 3) may be used. When the lower end processing examples 1 to 3 shown in FIGS. 17 to 22 are used instead of the lower end processing example 4, the relationship between the value Vres and the number of sub-scan feeds added in the upper end processing is changed. For example, in the third embodiment, when the lower end processing example 1 shown in FIGS. 17 and 18 is used instead of the lower end processing example 4, the relationship between the value Vres and the number of sub-scan feeds added in the upper end processing is , As follows.
When 1 ≦ Vres <6: Example 1 of upper end processing (FIGS. 30 and 31)
In the case of 6 ≦ Vres <17: 1 dot feed is added (Vres−5) times to the upper end processing example 1.

In the lower end processing examples 1 to 3 shown in FIGS. 17 to 22, the last sub-scan feed of the intermediate processing is not the last sub-scan feed (6 dot feed) of one unit cycle. In other words, in the lower end processing examples 1 to 3 shown in FIGS. 17 to 22, the unit cycle is not completed at the end of the intermediate processing. In this case, in order to keep the meaning of the value Vres as “the number of remaining raster lines recorded in the lower end processing”, the value Vres is defined by the following equation (2) instead of the above equation (1). do it.

{Vres = {(Lp−ΔL−Ln−δ)%} (2)

Here, δ is the total value of the feed amount of “sub-scan feed less than one unit cycle performed at the end of the intermediate processing”. For example, in the lower end processing example 1 shown in FIG. 18, δ is 5 [dots]. In the lower end processing example 2 shown in FIG. 20, δ is 7 [dots], and in the lower end processing example 3 shown in FIG. 22, δ is 10 [dots]. In the lower end processing example 4 shown in FIG. 24, it can be considered that δ is 0. The value δ in the equation (2) is considered to indicate a predetermined value associated with the positional relationship between the head position at the final printing position of the intermediate processing and the lower end line of the printing execution area. It is also possible. Expressions (1) and (2) are equivalent, and depending on which of these expressions defines the value Vres, the range of the value Vres and the number of sub-scan feeds added in the upper end processing are determined. Only the relationship is different.

In the second and third embodiments described above, the sub-scan feed amount in the upper end processing is always set to a constant value, but a plurality of types of sub-scan feed amounts may be used as the upper end process.

The present invention is not limited to the above-described examples and embodiments, and can be carried out in various modes without departing from the gist of the present invention. For example, the following modifications are possible.

(1) In the first embodiment, the irregular feed is employed in the intermediate processing. However, the present invention can be applied to a case where the sub-scan feed amount in the intermediate processing is constant. However, if the irregular feed is adopted in the intermediate processing, the sub-scan feed amount when reaching the lower end line of the print execution area and thereafter will differ depending on the paper setting and page setting. At this time, as shown in the first embodiment, the transitional feed amount at the time of transition from the intermediate processing to the lower end processing depends on the sub-scanning feed amount from the lower end line to the subsequent lines. Therefore, it is understood that the effect of the present invention is particularly large when the irregular feeding is employed in the intermediate processing.

(2) Depending on the dot recording mode in the intermediate processing, transition to the lower end processing does not require any transient feed, and the intermediate processing can always be immediately shifted to the lower end processing. However, even in such a case, in the lower end processing of the first embodiment, the recording is performed by each nozzle at the time of main scanning based on the dot recording history in the intermediate processing up to the vicinity of the lower end of the print execution area. The position of the dot is adjusted. The present invention has the effect of preventing the occurrence of an unrecordable dot position in the print execution area in the lower end process even when such a transient feed is not required at all.

(3) In the first embodiment, one sub-scanning feed pattern is prepared as the dot recording mode (particularly the sub-scanning feeding mode) in the upper end processing, and the dot recording mode in the lower end processing is near the end of the intermediate processing. A plurality of sub-scan feed patterns have been prepared in accordance with the sub-scan feed. In the second and third embodiments, only one sub-scanning feed pattern is prepared as the dot recording mode in the lower end process, and the dot recording mode in the upper end process is selected from a plurality of sub-scanning feed patterns. I was That is, in general, one of the upper-end processing and the lower-end processing can use a predetermined one sub-scanning feed pattern, and the sub-scanning feed pattern in the other processing may be selected from a plurality of sub-scanning feed patterns.

(4) It is also possible to adjust the number of sub-scan feeds in the upper end process so that the number of sub-scan feeds in the lower end process is as small as possible. Conversely, the number of sub-scan feeds in the lower end process may be adjusted so as to minimize the number of sub-scan feeds in the upper end process. That is, it is possible to adjust the number of sub-scan feeds in one of the upper end process and the lower end process so that the number of sub-scan feeds in the other process is as small as possible. In this case, it is preferable that the sub-scan feed amounts in the upper end processing and the lower end processing are respectively set to constant values. It is also possible to adjust the number of sub-scan feeds of the upper end process and the lower end process so that the total value of the number of sub-scan feeds in the upper end process and the lower end process is minimized.

(5) In the above embodiment, a part of the configuration realized by hardware may be replaced with software, and conversely, a part of the configuration realized by software may be replaced with hardware. Is also good.

FIG. 1 is a block diagram illustrating an example in which a printing apparatus according to an embodiment is configured around a computer. FIG. 2 is a block diagram illustrating a configuration of software related to print processing. FIG. 1 is a schematic configuration diagram illustrating a configuration of a color printer as an example of an image output apparatus. FIG. 3 is an explanatory diagram illustrating the structure of a print head 28. FIG. 3 is an explanatory diagram illustrating the principle of ink ejection. FIG. 6 is an explanatory diagram showing an arrangement of inkjet nozzles in the ink ejection heads 61 to 64. FIG. 4 is an explanatory diagram showing basic conditions of a general dot recording method when the number of scan repetitions s is 1; FIG. 4 is an explanatory diagram showing basic conditions of a general dot recording method when the number of scan repetitions s is 2 or more. FIG. 3 is an explanatory diagram illustrating a dot recording method in the intermediate processing according to the embodiment of the present invention. FIG. 7 is an explanatory diagram showing which nozzles are used to print each raster in the intermediate processing. FIG. 4 is an explanatory diagram showing a comparison between a sub-scan with a constant sub-scan feed amount and a sub-scan with irregular feed. FIG. 9 is an explanatory diagram illustrating an example of upper end processing used when performing adjustment by lower end processing. FIG. 9 is an explanatory diagram illustrating a case where lower end processing is not performed. FIG. 9 is an explanatory diagram illustrating a case where lower end processing is not performed. Explanatory drawing which shows the case where lower end processing was performed. Explanatory drawing which shows the case where lower end processing was performed. FIG. 6 is an explanatory diagram illustrating a lower end processing example 1 of the first embodiment. FIG. 6 is an explanatory diagram illustrating a lower end processing example 1 of the first embodiment. FIG. 9 is an explanatory diagram illustrating a lower end processing example 2 of the first embodiment. FIG. 9 is an explanatory diagram illustrating a lower end processing example 2 of the first embodiment. FIG. 9 is an explanatory diagram illustrating a lower end processing example 3 of the first embodiment. FIG. 9 is an explanatory diagram illustrating a lower end processing example 3 of the first embodiment. FIG. 9 is an explanatory diagram showing a lower end processing example 4 of the first embodiment. FIG. 9 is an explanatory diagram showing a lower end processing example 4 of the first embodiment. FIG. 3 is an explanatory diagram illustrating a state of sub-scan feed over a print execution area. FIG. 11 is an explanatory diagram illustrating a first example of the upper end process according to the second embodiment; FIG. 9 is an explanatory diagram illustrating a recording pattern of a first example of the upper end processing according to the second embodiment. FIG. 11 is an explanatory diagram illustrating an upper end processing example 2 of the second embodiment. FIG. 9 is an explanatory diagram illustrating a recording pattern of a first example of the upper end processing according to the second embodiment. FIG. 11 is an explanatory diagram illustrating an upper end processing example 1 of the third embodiment. FIG. 14 is an explanatory diagram illustrating a recording pattern of a first example of the upper end processing according to the third embodiment. FIG. 13 is an explanatory diagram illustrating a second example of the upper end process according to the third embodiment; FIG. 11 is an explanatory diagram illustrating a recording pattern of a second example of the upper end processing according to the third embodiment. FIG. 3 is an explanatory diagram illustrating an example of an interlace recording method. FIG. 3 is an explanatory diagram illustrating an example of an overlap recording method.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 12 ... Scanner 20 ... Image output device 21 ... Color display 22 ... Color printer 23 ... Paper feed motor 24 ... Carriage motor 26 ... Platen 28 ... Print head 31 ... Carriage 32 ... Operation panel 34 ... Sliding shaft 36 ... Drive belt 38 ... Pulley 39 ... Position detection sensor 40 ... Control circuit 42 ... PROM
61 to 64: ink discharge head 65: introduction pipes 71, 72 ... ink cartridge 80: ink passage 90 ... computer 91 ... video driver 93 ... CRT display 95 ... application program 96 ... printer driver 97 ... rasterizer 98 ... color correction module 99 Halftone module 100 to 103 Nozzle group

Claims (21)

In a dot recording apparatus that records dots on the surface of a print medium using a dot recording head,
A dot forming element array in which a plurality of dot forming elements for forming a plurality of dots of the same color at a substantially constant pitch along a sub-scanning direction are arranged at a portion of the dot recording head facing the print medium. When,
Main scanning drive means for performing main scanning by driving at least one of the dot recording head and the printing medium,
Head driving means for driving at least a part of the plurality of dot forming elements to form dots during the main scanning,
Sub-scanning driving means for performing sub-scanning by driving at least one of the dot recording head and the printing medium each time the main scanning is completed,
Control means for controlling each of the means,
The control means includes:
(I) a function of printing dots in a first printing mode near the upper end of a printing execution area of the print medium;
(Ii) a function of printing dots in a second printing mode in an intermediate portion of the printing execution area;
(Iii) near the lower end of the print execution area, a function of printing dots in a third print mode having at least a sub-scan feed amount different from the second print mode;
(Iv) irrespective of the length of the print execution area in the sub-scanning direction, a predetermined set of sub-scan feed patterns is set for one of the first and third print modes selected in advance. A function of selecting one of a plurality of sub-scan feed patterns for the other print mode according to the length of the print execution area in the sub-scan direction, so that it can be used;
A dot recording device comprising: The dot recording apparatus according to claim 1, wherein
The function (iV) is a function of the plurality of sub-scanning feed patterns for the third printing mode so that the predetermined set of sub-scanning feed patterns can be used for the first printing mode. In the third printing mode, each dot is selected during the main scanning based on the dot printing history up to the vicinity of the lower end of the printing execution area in the second printing mode. A dot recording apparatus including a function of adjusting a position of a dot recorded by a forming element. The dot recording apparatus according to claim 2, wherein
The plurality of sub-scanning feed patterns that can be used in the third printing mode are patterns in which the amount of transient sub-scanning feeding performed as needed at the start of the third printing mode is different from each other. ,
The function (iV) is
A dot having a function of selecting one of the plurality of sub-scan feed patterns for the third print mode based on a history of the sub-scan feed amount up to near the lower end of the print execution area; Recording device. The dot recording apparatus according to claim 3, wherein
The second printing mode is a mode in which a sub-scan is executed by repeatedly using a combination of a plurality of different sub-scan feed amounts as one unit cycle,
The third recording mode is a mode in which a sub-scan is executed using a constant sub-scan feed amount for a plurality of dots after the transient sub-scan feed. The dot recording apparatus according to claim 4, wherein
The presence or absence of the need for the transient sub-scan feed in the third recording mode and the value of the feed amount of the transient sub-scan feed are determined by continuing the sub-scan according to the second sub-scan mode. A dot recording device which is determined in accordance with a value of a sub-scan feed amount when a lower end element of the plurality of dot forming elements reaches a position after a lower end line of the recording execution area, . The dot recording apparatus according to claim 4, wherein
The necessity of the transient sub-scan feed in the third recording mode and the value of the feed amount of the transient sub-scan feed are determined according to a value Vres given by the following equation:
Vres = {(Lp−ΔL−Ln)%}
Here, Lp is the length of the print execution area in the sub-scanning direction, ΔL is the length from the upper end of the print execution area to the upper end of the area where the printing operation is performed in the second print mode, and Ln is The distance between the dot forming elements at both ends of the dot recording head, Σ is the total value of the sub-scan feed amount for one unit cycle in the second recording mode, and the operator “%” is an operation for taking the remainder of division. And a dot recording device, respectively. The dot recording apparatus according to claim 1, wherein
The plurality of sub-scan feed patterns that can be used in the first recording mode are patterns in which the sub-scan feed amount is constant and the number of sub-scan feeds is different from each other;
The second printing mode is a mode in which a sub-scan is executed by repeatedly using a combination of a plurality of different sub-scan feed amounts as one unit cycle,
The function (iV) has a function of determining the number of sub-scan feeds in the first print mode so that the predetermined set of sub-scan feed patterns can be used in the third print mode. Recording device. The dot recording apparatus according to claim 7, wherein
The number of sub-scan feeds in the first print mode is such that the positional relationship between the position of the dot print head at the final print position in the second print mode and the lower end of the print execution area falls within a predetermined range. The dot recording device is determined as follows. The dot recording apparatus according to claim 8, wherein
The number of sub-scan feeds in the first print mode is determined according to a value Vres given by the following equation:
Vres = {(Lp−ΔL−Ln)%}
Here, Lp is the length of the print execution area in the sub-scanning direction, ΔL is the length from the upper end of the print execution area to the upper end of the area where the printing operation is performed in the second print mode, and Ln is The distance between the dot forming elements at both ends of the dot recording head, Σ is the total value of the sub-scan feed amount for one unit cycle in the second recording mode, and the operator “%” is an operation for taking the remainder of division. And a dot recording device, respectively. The dot recording device according to any one of claims 1 to 9, wherein
In each of the first to third recording modes, the head driving unit performs one of the s (s is a predetermined integer of 2 or more) dots along the main scanning direction during one main scanning. (S-1) A dot recording apparatus that drives the plurality of dot forming element arrays at intermittent timings that prohibit dot formation for each dot. In a dot recording method for recording dots on the surface of a recording medium using a dot recording head having a plurality of dot forming elements,
(A) driving at least one of the dot recording head and the recording medium to perform main scanning;
(B) driving at least a part of the plurality of dot forming elements to form dots during the main scanning;
(C) performing a sub-scan by driving at least one of the dot recording head and the recording medium each time the main scanning is completed,
The plurality of dot forming elements can form a plurality of dots of the same color at a substantially constant pitch along the sub-scanning direction,
(I) In the vicinity of the upper end of the print execution area of the print medium, dot printing is performed by performing the steps (a) to (c) in the first printing mode,
(Ii) In an intermediate portion of the recording execution area, dots are recorded by executing the steps (a) to (c) in the second recording mode,
(Iii) In the vicinity of the lower end of the print execution area, the steps (a) to (c) are executed in the third print mode having at least a sub-scan feed amount different from that of the second print mode. Make a record,
(Iv) irrespective of the length of the print execution area in the sub-scanning direction, a predetermined set of sub-scan feed patterns is set for one of the first and third print modes selected in advance. A dot recording method, wherein one of a plurality of sub-scan feed patterns is selected for the other recording mode in accordance with the length of the recording execution area in the sub-scanning direction so that it can be used. . The dot recording method according to claim 11, wherein
One of the plurality of sub-scan feed patterns is selected for the third print mode so that the predetermined set of sub-scan feed patterns can be used for the first print mode, and In the third printing mode, based on the dot printing history up to the vicinity of the lower end of the printing execution area in the second printing mode, the dots printed by each dot forming element at the time of the main scanning are displayed. A dot recording method where the position is adjusted. The dot recording method according to claim 12, wherein
The plurality of sub-scanning feed patterns that can be used in the third printing mode are patterns in which the amount of transient sub-scanning feeding performed as needed at the start of the third printing mode is different from each other. ,
A dot recording method, wherein one of the plurality of sub-scanning feed patterns for the third printing mode is selected based on a history of the sub-scanning feed amount up to near the lower end of the print execution area. The dot recording method according to claim 13, wherein
The second printing mode is a mode in which a sub-scan is executed by repeatedly using a combination of a plurality of different sub-scan feed amounts as one unit cycle,
The dot recording method according to claim 3, wherein the third recording mode is a mode in which a sub-scan is executed using a constant sub-scan feed amount for a plurality of dots after the transient sub-scan feed. The dot recording method according to claim 14, wherein
The presence or absence of the need for the transient sub-scan feed in the third recording mode and the value of the feed amount of the transient sub-scan feed are determined by continuing the sub-scan according to the second sub-scan mode. A dot recording method that is determined according to a value of a sub-scan feed amount when a lower end element of the plurality of dot forming elements reaches a position after a lower end line of the print execution area, . The dot recording method according to claim 14, wherein
The necessity of the transient sub-scan feed in the third recording mode and the value of the feed amount of the transient sub-scan feed are determined according to a value Vres given by the following equation:
Vres = {(Lp−ΔL−Ln)%}
Here, Lp is the length of the print execution area in the sub-scanning direction, ΔL is the length from the upper end of the print execution area to the upper end of the area where the printing operation is performed in the second print mode, and Ln is The distance between the dot forming elements at both ends of the dot recording head, Σ is the total value of the sub-scan feed amount for one unit cycle in the second recording mode, and the operator “%” is an operation for taking the remainder of division. , Respectively, the dot recording method. The dot recording method according to claim 11, wherein
The plurality of sub-scan feed patterns that can be used in the first recording mode are patterns in which the sub-scan feed amount is constant and the number of sub-scan feeds is different from each other;
The second printing mode is a mode in which a sub-scan is executed by repeatedly using a combination of a plurality of different sub-scan feed amounts as one unit cycle,
A dot recording method, wherein the number of sub-scan feeds in the first print mode is determined so that the predetermined set of sub-scan feed patterns can be used in the third print mode. The dot recording method according to claim 17, wherein
The number of sub-scan feeds in the first print mode is such that the positional relationship between the position of the dot print head at the final print position in the second print mode and the lower end of the print execution area falls within a predetermined range. The dot recording method is determined as follows. The dot recording method according to claim 18, wherein
The number of sub-scan feeds in the first print mode is determined according to a value Vres given by the following equation:
Vres = {(Lp−ΔL−Ln)%}
Here, Lp is the length of the print execution area in the sub-scanning direction, ΔL is the length from the upper end of the print execution area to the upper end of the area where the printing operation is performed in the second print mode, and Ln is The distance between the dot forming elements at both ends of the dot recording head, Σ is the total value of the sub-scan feed amount for one unit cycle in the second recording mode, and the operator “%” is an operation for taking the remainder of division. , Respectively, the dot recording method. The dot recording method according to any one of claims 11 to 19, wherein
In each of the first to third recording modes, (s-1) dots among s (s is a predetermined integer of 2 or more) dots along the main scanning direction during one main scanning. A dot recording method, wherein the plurality of dot forming element arrays are driven at an intermittent timing at which dot formation is prohibited every minute. A computer-readable recording medium used in a dot recording apparatus including a computer and a dot recording head having a plurality of dot forming elements and recording a computer program for recording dots on a surface of a print medium using the dot recording head. Recording medium,
The computer program comprises:
(I) a function of printing dots in a first printing mode near the upper end of a printing execution area of the print medium;
(Ii) a function of printing dots in a second printing mode having a sub-scanning feed amount different from that of the first printing mode in an intermediate portion of the printing execution area;
(Iii) near the lower end of the print execution area, a function of printing dots in a third print mode having at least a sub-scan feed amount different from the second print mode;
(Iv) irrespective of the length of the print execution area in the sub-scanning direction, a predetermined set of sub-scan feed patterns is set for one of the first and third print modes selected in advance. A function of selecting one of a plurality of sub-scan feed patterns for the other print mode according to the length of the print execution area in the sub-scan direction, so that it can be used;
And a computer-readable recording medium that causes the computer to realize the above.

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