JP3663911B2 - Printing apparatus, printing method, and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printing apparatus and printing method for performing printing on a printing medium by performing sub-scanning in which a print head moves relative to the printing medium in one direction, and a recording medium on which a program for the printing is recorded.
[0002]
[Prior art]
Conventionally, ink jet printers have been widely used as printing apparatuses for printing images processed by a computer or the like. Inkjet printers perform printing by ejecting ink onto paper from nozzles provided in a print head to form dots. Normally, an inkjet printer forms an image while performing main scanning in which the print head reciprocates relative to the paper and sub-scanning in which the paper moves relative to the print head in one direction. As such an ink jet printer, there is known a type in which a plurality of nozzles are arranged in a print head at a predetermined pitch in the sub-scanning direction. Such a printer has an advantage that the printing speed is high because the plurality of nozzles can simultaneously print a plurality of dot rows in one main scan.
[0003]
In the case of an ink jet printer having a print head having a plurality of nozzles, deviations in dot formation positions occur due to variations in the characteristics of individual nozzles ejecting ink or variations in the array pitch between the plurality of nozzles. Sometimes. What is produced as a result of such a shift being visually recognized is called banding. When banding occurs, the quality of the printed image decreases.
[0004]
As a technique for avoiding banding, a technique called interlace printing as disclosed in, for example, U.S. Pat. No. 4,198,642 or JP-A-53-2040 is known. FIG. 18 is an explanatory diagram showing an example of an interlace method. First, various parameters used in the following description will be described. In the example of FIG. 18, the number of nozzles used for dot formation is three. The nozzle pitch k [dot] in FIG. 18 is a value that represents the interval between the center points of the nozzles in the recording head, with the recording image pitch (dot pitch w) as a unit. In the example of FIG. 18, k = 2. The number of scan repetitions s means the number of main scans required to fill each raster with dots. In the example of FIG. 18, since each raster is filled by one main scan, the number of scan repetitions s is one. When the number of scan repetitions s is 2 or more, in each main scan, dots are intermittently formed along the main scan direction. L in FIG. 18 means the paper feed amount in the sub-scan, and corresponds to 3 rasters in this example.
[0005]
In FIG. 18, circles including two-digit numbers indicate dot recording positions. Among the two-digit numbers in the circle, the number on the left side indicates the nozzle number, and the number on the right side indicates the printing order (how many times the main scanning was recorded).
[0006]
In the interlaced recording shown in FIG. 18, the dots of each raster are formed by the second nozzle and the third nozzle in the first main scan. The first nozzle does not form dots. Next, as shown in FIG. 18, after feeding paper for three rasters, each raster is formed using the first nozzle to the third nozzle while performing the second main scan. Thereafter, an image is recorded by repeatedly executing paper feeding for three rasters and forming a raster by main scanning in the same manner. The reason why the raster is not formed by the first nozzle in the first main scan is that the raster adjacent to the raster cannot be formed in the second and subsequent main scans.
[0007]
The interlace method is a method of recording an image while intermittently forming rasters in the sub-scanning direction. This interlace method has an advantage that variations in nozzle pitch, ink ejection characteristics, and the like can be dispersed on a recorded image. Therefore, even if there are variations in the nozzle pitch and ejection characteristics, it is possible to alleviate these effects and improve the image quality.
[0008]
FIG. 18 illustrates the case where each raster is formed by one main scan at a specific nozzle pitch. In general, in interlaced recording, the nozzle pitch k and the number of nozzles Nnz are selected to be relatively prime. At this time, the feed amount L is set to a value L = Nnz / s using the nozzle number Nnz and the scan repetition number s. Interlaced recording is often realized by setting the above parameters under such conditions.
[0009]
[Problems to be solved by the invention]
However, even when the above-described interlace printing is used, if there is an error in the paper feed amount in the sub-scanning, banding may occur due to accumulation of the error, and the image quality may be deteriorated. In recent years, the resolution of ink jet printers has increased, and high-quality printing has been demanded. Therefore, such a deterioration in image quality cannot be overlooked. Such a problem occurs not only in an ink jet printer but also in various printing apparatuses that form dots and print an image.
[0010]
In interlace, parameters such as the number of nozzles Nnz are often selected so as to satisfy the above conditions. Accordingly, in some cases, some of the nozzles provided in the head may not be used for printing in the interlace mode. In this case, there is a possibility that ink clogging may occur at nozzles that are not used for printing.
[0011]
[Means for solving the problems and their functions and effects]
The first object of the present invention is to provide a technique that suppresses the occurrence of banding and enables high-quality printing. A second object is to avoid the deviation of nozzles used in interlaced printing. In order to solve at least a part of the above problems, the present invention adopts the following configuration.
[0012]
The printing apparatus of the present invention includes:
A sub-scan that drives the head to form a raster that is a dot row aligned in one direction of the print medium, and moves the print medium relative to the head in one direction that intersects the raster each time the raster is formed. A printing device for printing an image,
The head is a head provided with a plurality of dot forming elements that form dots on the print medium arranged in the sub-scanning direction;
Selecting means for selecting at least one dot-forming element among the plurality of dot-forming elements as an effective element to be used for dot formation at least once after starting printing of the image;
The sub-scan feed amount Q after the selection is set according to the positional relationship between the dot formation element that has been used for dot formation before the selection and the dot formation element that is used for dot formation after the selection. Feed amount setting means to perform,
Sub-scanning means for performing the sub-scanning with the set feed amount;
A gist of the invention is that it includes a print head driving unit that drives only the selected dot forming element among the dot forming elements to form dots.
[0013]
The printing method of the present invention includes:
A sub-scan that drives the head to form a raster that is a dot row aligned in one direction of the print medium, and moves the print medium relative to the head in one direction that intersects the raster each time the raster is formed. Of the printing methods for printing images,
A printing method for printing an image using a head comprising a plurality of dot forming elements for forming dots on the print medium arranged in the sub-scanning direction,
(A) at least once after starting the printing of the image, selecting at least some of the plurality of dot forming elements as effective elements for forming dots; and
(B) a step of setting a sub-scan feed amount after the selection according to dot forming elements used for dot formation before and after the selection;
(C) performing the sub-scanning with the set feed amount;
(D) The present invention includes a step of forming dots by driving only the selected dot forming elements among the dot forming elements.
[0014]
In the printing apparatus and printing method of the present invention, after printing of an image is started, a dot forming element is selected as an effective element to be used for dot formation, and the subsequent sub-scan feed amount is set according to the selection result. Set. For example, assume that ten dot forming elements are provided in the order of # 1, # 2,..., # 10, and an image is formed using these. In the printing apparatus, after starting image printing, for example, eight dot forming elements # 1, # 2,..., # 8 are selected as effective elements. Thereafter, dots are formed by the eight selected elements, and dots are not formed by # 9 and # 10. Further, the sub-scan feed amount is set according to which dot forming element is selected.
[0015]
If the element used for dot formation changes, the sub-scan feed amount changes accordingly. As described above, in the printing apparatus of the present invention, the sub-scan feed amount changes after the image printing is started. The feed error that occurs in the sub-scan often changes depending on the feed amount. The error corresponding to the feed amount may appear in a direction where the feed amount is excessive or may appear in a direction where it is too small. In the printing apparatus of the present invention, by changing the sub-scan feed amount, a part of the feed amount error cancels out, and the sub-scan feed error can be suppressed as a whole. For this reason, the printing apparatus of the present invention can suppress banding and improve the image quality of a printed image.
[0016]
Moreover, in the printing apparatus of this invention, the dot formation element used for printing changes as mentioned above. Accordingly, it is possible to avoid the deviation of the dot forming elements used during printing. As a result, when the dot forming element is an element that forms dots by discharging ink, for example, clogging or the like can be prevented.
[0017]
In the above printing apparatus and printing method, after the dot formation element is selected, the sub-scan feed amount is set according to the selection result. However, both may be set in the reverse order. . That is, it is also possible to first set the sub-scan feed amount and then select a dot forming element to be used for dot formation according to the setting. In short, any method may be used as long as there is a correlation between the selection of the dot formation element and the sub-scan feed amount during image printing.
[0018]
In the printing apparatus or the like, the selection is made “at least once after image printing is started” because the selection is made after an image of a predetermined area is printed or a raster is formed. Means that all of the above selections are included. Further, “at least a part of the plurality of dot forming elements” means that all dot forming elements may be selected. In addition, every other dot forming element may be selected so as to skip some of the dot forming elements arranged in the sub-scanning direction. However, in this specification, “selection” means selection with a difference in the dot forming elements used for dot formation before or after the selection or the sub-scan feed amount.
[0019]
In the above description, the case where there are 10 dot forming elements has been described as an example, but the above effect does not depend on the number of dot forming elements. The effective dot forming element may be selected any number of times. For example, the selection may be performed every time a raster is formed. In the above description, some of the ten dot forming elements provided in the head are selected. However, all elements provided in the head may be selected. It is sufficient that some elements used for dot formation are different before and after the selection.
[0020]
In the above printing apparatus,
It is desirable that the effective element selected by the selecting means is a continuous dot forming element.
[0021]
In this way, it is possible to easily set the sub-scan feed amount for forming a raster with no gap in the sub-scan direction.
[0022]
In the printing apparatus,
Of the dot forming elements, the number of elements used for dot formation is preferably a predetermined number N.
[0023]
In such a printing apparatus, the number of elements used for printing an image is always constant before and after the dot formation element is selected. Accordingly, the sub-scan feed amount after the selection can be set easily and appropriately.
[0024]
In this case,
The plurality of dot forming elements provided in the head are arranged at a predetermined pitch in the sub-scanning direction between adjacent dot forming elements.
The sub-scan feed amount Q set by the feed amount setting means is preferably a feed amount given in units of dot recording pitch in the sub-scanning direction according to the following equation.
Q = N−k (ji)
Here, k is a value representing the interval in the sub-scanning direction of the dot forming elements in units of the dot recording pitch in the direction,
i is positioned at one end of the dot forming elements used for dot formation before the selection when the element numbers are given from one end of the array of the dot forming elements with the sub-scanning direction as the normal order. Element number of the element,
j is an element number of an element located at an end corresponding to one of the dot forming elements used for dot formation after the selection.
[0025]
In this way, even when the dot forming element used for forming the dot is changed, the dot can be appropriately formed without generating a blank raster.
[0026]
In the printing apparatus,
Of the dot forming elements, the number of elements used for dot formation may change in a predetermined order.
[0027]
This increases the degree of freedom in selecting effective elements for dot formation. Accordingly, it is possible to select the dot formation element and set the sub-scan feed amount so that the effects such as the improvement of the image quality are further improved.
[0028]
Furthermore, the printing apparatus of the present invention includes:
The print head driving means is means for dividing each raster into two or more predetermined times S across the sub-scan,
The feed amount setting means is a means for setting the feed amount of the sub-scan after the selection in accordance with the dot forming element used for dot formation before and after selection and the number of divisions S of each raster. It can also be.
[0029]
According to such a printing apparatus, each raster can be formed by a so-called overlap method. For example, in the overlap method in which each raster is formed in two steps, odd-numbered dots of each raster are formed at the first time, and even-numbered dots are formed at the second time using dot formation elements different from the first time. Form. Similarly, each raster can be formed in three or more times. In the overlap method, by recording each raster with different dot forming elements, it is possible to disperse the deviation of the dot forming positions caused by mechanical manufacturing errors of each element, and to reduce banding. . The above printing apparatus employs an overlap method, thereby enabling higher quality printing.
[0030]
In this case,
Of the dot forming elements, the number of elements used for dot formation is preferably a predetermined number N. By so doing, it is possible to easily and appropriately set the sub-scan feed amount after the selection.
[0031]
In this case,
The plurality of dot forming elements provided in the head are arranged at a predetermined pitch in the sub-scanning direction between adjacent dot forming elements.
The sub-scan feed amount Q set by the feed amount setting means is preferably a feed amount given in units of dot recording pitch in the sub-scanning direction according to the following equation.
Q = (N / S) -k (ji)
here,
k is a value representing the interval in the sub-scanning direction of the dot forming element in units of the recording pitch of the dots in the direction,
i is positioned at one end of the dot forming elements used for dot formation before the selection when the element numbers are given from one end of the array of the dot forming elements with the sub-scanning direction as the normal order. Element number of the element,
j is an element number of an element located at an end corresponding to one of the dot forming elements used for dot formation after the selection.
[0032]
In this way, even when the dot forming element used for forming the dot is changed, the dot can be appropriately formed without generating a blank raster. In the present invention, when the number of dot forming elements is A in total, the number N of selected dot forming elements is smaller than A (N <A). Further, the interval k between the dot forming elements in the sub-scanning direction and (N / S) are relatively prime. The number of divisions S of each raster is a factor of N.
[0033]
Of course, in a printing apparatus capable of recording each raster by the so-called overlap method,
Of the dot forming elements, the number of elements used for dot formation may change in a predetermined order.
By doing so, there is an advantage that the degree of freedom in selecting the dot forming element is increased.
[0034]
If the printing apparatus described above is specifically configured,
A sub-scan that drives the head to form a raster that is a dot row aligned in one direction of the print medium, and moves the print medium relative to the head in one direction that intersects the raster each time the raster is formed. A printing device for printing an image,
The head is a head provided with a plurality of nozzles for forming dots on the print medium arranged in the sub-scanning direction,
A memory storing data for selecting at least some of the plurality of nozzles as effective nozzles for forming dots at least once after printing of the image is started;
A sub-scanning controller that performs the sub-scanning by a sub-scan feed amount after the selection according to the nozzles used for dot formation before and after the selection;
The printing apparatus includes a print head controller that drives only the nozzles selected based on the data stored in the memory among the nozzles to form dots.
[0035]
The printing apparatus includes a nozzle as the dot forming element described above. Such nozzles include those that eject ink and form dots on a print medium. However, the above description does not mean that the printing apparatus of the present invention can be applied only to a printing apparatus that ejects ink. Further, the selection of nozzles after the start of printing and the setting of the feed amount of sub-scanning after selection are electrically realized using a memory and a controller, respectively. As such a controller, a general-purpose control element such as a so-called CPU may be used, or a dedicated control circuit may be used.
[0036]
Note that all the printing apparatuses of the present invention described above perform not only the type of printing apparatus that forms a raster while performing main scanning in which the head moves reciprocally relative to the print medium, but also such main scanning. It can also be configured as a printing apparatus that forms a raster without performing it. Further, the present invention is applicable not only to a printing apparatus that ejects ink, but also to a so-called impact dot type printing apparatus and a thermal transfer type printing apparatus.
[0037]
The printing apparatus of the present invention described above can also be configured by realizing control of a head for recording dots and sub-scanning by a computer. Therefore, the present invention can also take the form of a recording medium on which such a program is recorded.
[0038]
The recording medium of the present invention is
A printing apparatus including a head having a plurality of dot forming elements that form dots, and a program for controlling sub-scanning in which a print medium is moved relative to the head in one direction is recorded in a computer-readable manner. A recording medium,
A function of selecting at least a part of the plurality of dot forming elements as effective elements to be used for dot formation at least once after printing an image;
It is a recording medium on which a program for realizing a function of setting a feed amount of sub-scanning after selection according to dot forming elements used for dot formation before and after the selection is recorded.
[0039]
By executing the program recorded on the recording medium by the computer, the above-described printing apparatus of the present invention can be realized. Storage media include flexible disks, CD-ROMs, magneto-optical disks, IC cards, ROM cartridges, punch cards, printed materials printed with codes such as bar codes, and computer internal storage devices (memory such as RAM and ROM). ) And external storage devices can be used. Further, an aspect as a program supply apparatus that supplies a computer program for realizing a control function of the printing apparatus to a computer via a communication path is also included.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples.
(1) Device configuration:
FIG. 1 is a block diagram showing a configuration of an image processing apparatus using a color printer 22 as an embodiment of a printing apparatus of the present invention. As shown in the figure, a scanner SCN and a color printer 22 are connected to a computer 90. The computer 90 can handle images captured from the scanner SCN or the like by various application programs. When an image print command is issued from the application program, the computer 90 activates an internal printer driver to convert the print image data into print data that can be printed by the printer 22 and outputs the print data to the printer 22. The printer 22 receives this print data and prints an image while executing various controls described later. As will be described later, the printer 22 of this embodiment can perform printing in various modes. The data transferred from the computer 90 to the printer 22 includes data for designating a print mode.
[0041]
The computer 90 includes a flexible disk drive 15 and a CD-ROM drive 16, and can read programs recorded on the flexible disk FD and the CD-ROM, respectively. The computer 90 can be connected to the public telephone line PNT via the modem 18. The computer 90 can also connect to a specific server SV connected to an external network through the public telephone line PNT and download the program to a hard disk inside the computer 90. Further, since the computer 90 can transfer various data to the printer 22, the computer 90 can also transfer the program to the printer 22.
[0042]
FIG. 2 is a block diagram showing the software configuration of this embodiment. The printer 22 according to this embodiment includes a print mode setting unit 1, a print mode table 12, a drive unit control unit 2, a main scan drive unit 3, a sub scan drive unit 4, a print head drive unit 5, and a raster data storage unit 6. Is done.
[0043]
Data transferred from the computer 90 to the printer 22 includes print image data and print mode designation data. The print mode setting unit 1 refers to the print mode table 12 according to the print mode designation data, and sets the nozzles used for forming dots, the sub-scan feed amount, and the like. The contents of the print mode table 12 will be described in detail later. The various quantities set by the print mode setting unit 1 are transmitted to the drive unit control unit 2. The drive unit control unit 2 controls the drive amounts and drive timings of the main scanning drive unit 3, the sub-scanning drive unit 4, and the print head drive unit 5. The main scanning driving unit 3 performs main scanning that reciprocates the print head, and the sub scanning driving unit 4 conveys the paper in the sub scanning direction that intersects the main scanning direction. The print head drive unit 5 drives the nozzles of the print head based on the print image data stored in the raster data storage unit 6 to eject ink onto the paper.
[0044]
Next, a schematic configuration of the printer 22 will be described with reference to FIG. As shown in the figure, the printer 22 includes a mechanism for transporting the paper P by the paper feed motor 23, a mechanism for reciprocating the carriage 31 in the axial direction of the platen 26 by the 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. . Hereinafter, each mechanism and the like will be described in this order.
[0045]
The mechanism for reciprocating the carriage 31 in the axial direction of the platen 26 is an endless drive belt between the carriage motor 24 and a slide shaft 34 that is installed in parallel with the axis of the platen 26 and slidably holds the carriage 31. 36, a pulley 38 for extending 36, a position detection sensor 39 for detecting the origin position of the carriage 31, and the like.
[0046]
The carriage 31 accommodates a black ink (Bk) cartridge 71 and inks of five colors, cyan (C1), light cyan (C2), magenta (M1), light magenta (M2), and yellow (Y). The color ink cartridge 72 can be mounted. For two colors, cyan and magenta, two types of light and dark inks are provided. A total of six ink ejection heads 61 to 66 are formed on the print head 28 below the carriage 31. An inlet pipe 67 (which guides ink from the ink tank to the color heads) is provided at the bottom of the carriage 31. (See FIG. 4). When a black (Bk) ink cartridge 71 and a color ink cartridge 72 are mounted on the carriage 31 from above, an introduction tube 67 is inserted into a connection hole provided in each cartridge, and the ejection heads 61 to 66 are ejected from each ink cartridge. Ink can be supplied to the printer.
[0047]
A mechanism for ejecting ink and forming dots will be described. FIG. 4 is an explanatory diagram showing a schematic configuration inside the ink ejection head 28. 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 67 using the capillary phenomenon as shown in FIG. The print head 28 is guided to each color head 61 to 66. When the ink cartridge is first installed, an operation of sucking ink to the respective color heads 61 to 66 is performed by a dedicated pump. In this embodiment, a pump for sucking and a cap for covering the print head 28 at the time of sucking are performed. The illustration and description of such a configuration is omitted.
[0048]
As will be described later, the heads 61 to 66 for each color are provided with 48 nozzles Nz for each color (see FIG. 6). Each nozzle is one of electrostrictive elements and is responsive. An excellent piezo element PE is arranged. FIG. 5 shows the structure of the piezo element PE and the nozzle Nz in detail. As illustrated in the upper part of FIG. 5, the piezo element PE is installed at a position in contact with the ink passage 68 that guides ink to the nozzle Nz. As is well known, the piezo element PE is an element that transforms electro-mechanical energy at a very high speed because the crystal structure is distorted by application of voltage. 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 extends for the voltage application time as shown in the lower part of FIG. One side wall of 68 is deformed. As a result, the volume of the ink passage 68 contracts according to the expansion of the piezo element PE, and the ink corresponding to the contraction becomes particles Ip and is ejected from the tip of the nozzle Nz at high speed. Printing is performed by the ink particles Ip soaking into the paper P mounted on the platen 26.
[0049]
FIG. 6 is an explanatory diagram showing the arrangement of the inkjet nozzles Nz in the ink ejection heads 61-66. The arrangement of these nozzles consists of six sets of nozzle arrays that eject ink for each color, and 48 nozzles Nz are arranged in a staggered manner at a constant nozzle pitch k. The positions of the nozzle arrays in the sub-scanning direction coincide with each other. Note that the 48 nozzles Nz included in each nozzle array need not be arranged in a staggered manner, and may be arranged on a straight line. However, when arranged in a zigzag pattern as shown in FIG. 7, there is an advantage that the nozzle pitch k can be easily set small.
[0050]
FIG. 7 shows an enlarged view of the nozzle array and the state of dots formed by the nozzle array. The left side of FIG. 7 is an enlarged view of the nozzle array, and the right side is a state of dots to be formed. A circle indicated by a broken line on the right side means dots that can be formed by sub-scanning the nozzle array. That is, in this embodiment, there is a relationship of nozzle pitch: recording pitch = 2: 1. In order to prevent so-called white spots of dots, each dot is formed with a diameter that partially overlaps with dots adjacent to each other in the main scanning direction and the sub-scanning direction.
[0051]
Finally, the internal configuration of the control circuit 40 of the printer 22 will be described, and a method for driving the head 28 including the plurality of nozzles Nz shown in FIG. 6 will be described. FIG. 8 is an explanatory diagram showing the internal configuration of the control circuit 40. As shown in FIG. 8, the control circuit 40 includes a CPU 41, a PROM 42, a RAM 43, a PC interface 44 for exchanging data with the computer 90, a paper feed motor 23, a carriage motor 24, an operation panel 32, and the like. A peripheral input / output unit (PIO) 45 for exchanging signals with the timer, a timer 46 for timing, a driving buffer 47 for outputting dot on / off signals to the heads 61 to 66, and the like. These elements and circuits are connected to each other via a bus 48.
[0052]
The control circuit 40 is also provided with a transmitter 51 that outputs a drive waveform (see FIG. 9) at a predetermined frequency, and a distributor 55 that distributes the output from the transmitter 51 to the heads 61 to 66 at a predetermined timing. ing. The control circuit 40 receives the print image data processed by the computer 90, temporarily stores it in the RAM 43, and outputs it to the drive buffer 47 at a predetermined timing. The control circuit 40 performs main scanning control of the carriage 31, driving control of each nozzle, sub scanning control, and the like. The driving buffer 47 corresponds to the raster data storage unit 6 shown in FIG.
[0053]
A mode in which the control circuit 40 outputs signals to the heads 61 to 66 will be described. FIG. 9 is an explanatory diagram showing connection of one nozzle row of the heads 61 to 66 as an example. One nozzle row of the heads 61 to 66 is interposed in a circuit having the drive buffer 47 as the source side and the distribution output device 55 as the sink side, and each piezo element PE constituting the nozzle row has its electrode. One of these is connected to each output terminal of the drive buffer 47, and the other is connected to the output terminal of the distribution output device 55 all together. As shown in FIG. 9, a driving waveform of the transmitter 51 is output from the distribution output device 55. When the CPU 41 determines ON / OFF for each nozzle and outputs a signal to each terminal of the drive buffer 47, only the piezo element PE that has received the ON signal from the drive buffer 47 side is driven according to the drive waveform. The As a result, the ink particles Ip are simultaneously ejected from the nozzles of the piezo element PE that has received the ON signal from the drive buffer 47.
[0054]
As shown in FIG. 6, since the heads 61 to 66 are arranged along the transport direction of the carriage 31, the timing at which each nozzle row reaches the same position with respect to the paper P is shifted. Accordingly, the CPU 41 outputs the dot ON / OFF signal via the driving buffer 47 at a necessary timing after taking into account the displacement of the nozzles of the heads 61 to 66, and sets the dots of the respective colors. Forming. Further, as shown in FIG. 6, the output of the on / off signal is controlled in consideration of the fact that the nozzles are formed in two rows in each of the heads 61 to 66.
[0055]
In the printer 22 having the hardware configuration described above, the carriage 31 is reciprocated by the carriage motor 24 while the paper feed motor 23 rotates the paper feed roller and other rollers to convey the paper P, and at the same time the print head. The piezo elements PE of the 28 color heads 61 to 66 are driven to discharge the inks of the respective colors to form dots and form a multicolor image on the paper P.
[0056]
In this embodiment, as described above, the printer 22 having the head for ejecting ink using the piezo element PE is used. However, a printer for ejecting ink by other methods may be used. For example, the present invention may be applied to a printer of a type in which electricity is supplied to a heater arranged in the ink passage and ink is ejected by bubbles generated in the ink passage. Further, a so-called dot impact type printer or thermal transfer type printer may be used.
[0057]
(2) Print control processing
Next, print control processing in the printer 22 of this embodiment will be described. FIG. 10 is a flowchart showing the flow of the print control process. This process is a process executed by the CPU 41 of the printer 22 (see FIG. 8). When the print control process is started, the CPU 41 reads print image data (step S100). This print image data is data processed by the computer 90 and is a data string indicating ON / OFF of each nozzle of each head 61 to 66 of the printer 22. The CPU 41 reads the print mode designation data together with the print image data (step S105), and sets the used nozzle block based on the print mode designation data (step S110).
[0058]
The setting of the print mode and the used nozzle block will be described. In other words, the setting of the used nozzle block is a process performed by the print mode setting unit 1 shown in FIG. 2 with reference to the print mode table 12. FIG. 11 shows the contents of the print mode table 12 in this embodiment. As described above, the printer 22 of this embodiment is actually provided with 48 nozzles in each head, but in the following, it is assumed that the printer 22 is provided with 8 nozzles for convenience of explanation. explain.
[0059]
The printing mode table 12 records printing procedures such as printing resolution, printing mode corresponding to the printing resolution, combination of nozzle blocks to be used (change order), transport amount (sub-scanning amount), and the like. In this embodiment, when the print resolution is 360 dpi, the normal or nozzle block selection interlace mode can be selected as the print mode. When the print resolution in the print data is 720 dpi, the normal interlace overlap printing and the nozzle block selection interlace mode can be selected as the print mode. It should be noted that the print image data transferred from the computer 90 is the same for each printing in the above two modes of 360 dpi. The print image data used for printing in the two modes of 720 dpi is also common. The print mode designation data read in step S105 is data for specifying the resolution and each print mode.
[0060]
The setting contents of the print mode table 12 for the resolution of 360 DPI will be described. For the normal print mode, values such as the number of scan repetitions = 1, the number of used nozzles = 3, the used nozzle block = 1, and the sub-scan = 3 are stored in the print mode table 12. The number of scan repetitions means the number of main scans required to form each raster. The number of used nozzles indicates the number of nozzles actually used for printing among the nozzles provided in the head. FIG. 12 shows the correspondence between the nozzles used and the resolution. As shown in the figure, among the eight nozzles provided in the head, four nozzles # 1 to # 4 can be used when printing at a low resolution of 360 DPI. As shown in FIG. 11, when the normal print mode is selected, printing is executed using the three nozzles. The value stored in the used nozzle block specifies the first nozzle in the nozzle row used for printing among the plurality of nozzles provided in the head. In the normal printing mode, the value of the used nozzle block is 1. Since the number of nozzles used is three as described above, this means that the three nozzles # 1, # 2, and # 3 are used for printing. The sub-scanning amount represents the sub-scan feed amount in units of dot recording pitch.
[0061]
When the resolution is 360 DPI and the nozzle block selection interlace mode is selected, the respective parameters are set as follows. The number of scan repetitions and the number of used nozzles are the same as in the normal printing mode. That is, in each main scan, three nozzles were selected to form nozzle blocks. The nozzle block used has three values 1, 2, and 1. The used nozzle block is sequentially changed with the main scanning. This means that the three used nozzle blocks are periodically used as 1 → 2 → 1 → 1 → 2. Although the used nozzle block is changed, the number of used nozzles is constant at three. The correspondence between the used nozzle block and the number of the nozzle used for printing is as follows.
Used nozzle block = 1 → # 1, # 2, # 3;
Used nozzle block = 2 → # 2, # 3, # 4;
Further, the sub-scanning amount is also changed sequentially with the main scanning. Values 3, 1, and 5 are set as sub-scanning amounts for the used nozzle block values 1, 2, and 1, respectively.
[0062]
The relationship between the used nozzle block and the sub-scan feed amount is as follows. If the number of nozzles used is N, the nozzle interval in the nozzle array in the sub-scanning direction is k-dot pitch (see FIG. 6), and the nozzle block used is changed from i to j, then the sub-scan feed amount Q is 1).
Q = N−k (j−i) (1)
For example, in this embodiment, the nozzle interval k is a value 2, and the number N of used nozzles is a value 3. If the used nozzle block is changed from 1 to 2, the sub-scan feed amount Q is
Q = 3-2 (2-1) = 1
Is required. In the sub-scanning amount corresponding to the used nozzle block 2 in FIG. 11, the value 1 thus obtained is stored.
[0063]
The contents of the print mode table 12 for the resolution 720 DPI are as follows. In the normal print mode, the number of scan repetitions is set to value 2, the number of used nozzles is set to value 6, the used nozzle block is set to 1, and the sub-scanning amount is set to value 3. Since the scan repetition number is 2, each raster is formed by two main scans. This means that printing by the so-called overlap method is performed. When the resolution is high, high image quality is often desired, and therefore, the overlap printing is employed. Of course, each raster may be formed by one main scan. As shown in FIG. 12, in the case of resolution 720 DPI, all eight nozzles & 1 to & 8 can be used. In the normal printing mode, six nozzles from & 1 to & 6 are used.
[0064]
On the other hand, in the case of nozzle block selection interlace, the number of scan repetitions and the number of used nozzles are the same as in the normal print mode. The used nozzle block is sequentially changed with the main scanning. In the used nozzle block, six values 1, 2, 3, 3, 2, and 1 are set, which means that the nozzles used for printing change periodically in this order. The correspondence between the used nozzle block and the number of the nozzle used for printing is as follows.
Used nozzle block = 1 & 1 & 2 & 3 & 4 & 5 &6;
Used nozzle block = 2 → & 2, & 3 & 4 & 5 & 6 &7;
Nozzle block used = 3 → & 3, & 4, & 5, & 6, & 7, &8;
In this case, the carry amount (sub-scan amount) is also changed sequentially with the main scan. For the used nozzle block values 1, 2, 3, 3, 2, 1, values 3, 1, 1, 3, 5, and 5 are set as sub-scanning amounts, respectively.
[0065]
The relationship between the used nozzle block and the sub-scan feed amount is as follows. If the number of used nozzles is N, the nozzle interval is k dot pitch (see FIG. 6), the number of scan repetitions is S, and the used nozzle block is changed from i to j, then the sub-scan feed amount Q is 2).
Q = (N / S) − (j−i) k (2)
For example, in this embodiment, the nozzle interval k is a value 2 and the number N of used nozzles is a value 6. If the used nozzle block is changed from 1 to 2, the sub-scan feed amount Q is
Q = (6/2) -2 (2-1) = 1;
Is required. In the sub-scanning amount corresponding to the used nozzle block 2 in FIG. 11, the value 1 thus obtained is stored.
[0066]
In the above description, when the number of nozzles constituting the nozzle array of the print head 28 is A, the number N of nozzles constituting the nozzle block is smaller than A (N <A), and k and N / S are relatively small. And S is a factor of N.
[0067]
Returning to FIG. 10, the contents of the print control processing routine will be described. In setting the use nozzle block (step S110), the use nozzle block corresponding to the print mode designation data is selected with reference to the print mode table 12 in which the various values described above are stored.
[0068]
Next, the CPU 41 performs main scanning to form dots (step S115). This processing can be rephrased as main scanning and printing operations performed by the main scanning driving unit 3 via the driving unit control unit 2 in FIG. At this time, the CPU 41 executes a process for forming a raster using the previously used nozzle block. That is, the data transfer destination to the drive buffer 47 (see FIG. 8) is controlled according to the used nozzle block. For example, when the nozzles # 1 to # 3 are used among the nozzles # 1 to # 4 shown in FIG. 12, the print image data read in step S100 is used as the nozzles # 1 to # 1 of the drive buffer 47. Transfer to the location corresponding to # 3. In # 4, mask data for preventing ink from being ejected is transferred.
[0069]
After the main scan is performed to form the raster, it is determined whether or not printing is finished (step S120). This is determined, for example, by the presence or absence of unprocessed print image data in the print image data temporarily stored in the RAM 43 or the like, or the presence or absence of transfer of print image data from the computer 90. Is determined to be the end of printing.
[0070]
If there is unprocessed print image data or the like, it is determined that printing is to be continued. Next, the print mode table 12 is referred to and the sub-scanning amount is set (step S125). In other words, the print mode setting unit 1 reads the sub-scanning amount of the print mode table 12. Next, sub-scanning is performed based on this sub-scanning amount (step S130). In other words, the sub-scanning is performed by the sub-scanning driving unit 4 via the driving unit control unit 2. Thereafter, similarly, main scanning and sub-scanning are continued until there is no print image data.
[0071]
Note that, when overlap (nozzle block selection overlap mode) is selected as the print mode, main scanning and sub-scanning are performed in the same procedure.
[0072]
Next, a specific operation of the inkjet printer 22 according to the present embodiment will be described with reference to FIGS. FIG. 13 is an explanatory diagram showing how dots are formed in the normal mode at a resolution of 360 DPI (hereinafter referred to as low resolution). For convenience of illustration, in the example of FIG. 13, the print head is illustrated as including a nozzle array having four nozzles with a nozzle pitch of 2 dots. These four nozzles correspond to # 1 to # 4 shown in FIG. A nozzle is indicated by a circled number on the left side of FIG. The numbers in the circles indicate # 1 to # 4 in FIG. FIG. 13 shows the relative positions of the heads in the first to sixth main scans. The state of the dot row formed when the head is at each position is shown on the right side of FIG. Each circled number represents a dot row. The numbers mean the numbers of the nozzles forming each dot.
[0073]
As shown in FIG. 11, in the normal printing mode at a low resolution, printing is performed using three lines # 1 to # 3. Therefore, in FIG. 13, the # 4 nozzle that is not used for dot formation is indicated by a broken line. When sub-scanning is performed using these three nozzles with a fixed sub-scanning amount equivalent to 3 dots, an image can be printed as shown on the right side of FIG. In the first main scanning, the nozzle # 1 does not form a dot. This is because, as shown on the right side of FIG. 13, the raster adjacent to the lower side becomes a blank raster because of the sub-scanning.
[0074]
FIG. 14 is an explanatory diagram showing how dots are formed in the nozzle block selection interlace mode at a low resolution. The meaning of the symbols in the figure is the same as in FIG. The dot recording in this mode will be described with reference to FIG. Since the value 3 is set as the number of used nozzles in FIG. 11, in this mode, the number of nozzles used in all main scans is three. In the first main scan, nozzles # 1 to # 3 are used. In FIG. 14, the # 4 nozzle that is not used for dot formation is indicated by a broken line. However, for the same reason as in FIG. 13, the nozzle # 1 does not actually form dots.
[0075]
In the second main scan, nozzles # 2 to # 4 are used. In FIG. 14, the # 1 nozzle that is not used for dot formation is indicated by a broken line. At this time, as can be seen from FIG. 11, the sub-scan feed amount is set to 1. Therefore, when shifting to the second main scanning, after performing sub-scanning for one dot, main scanning is performed to form dots. In the third main scan, the nozzles # 1 to # 3 are used again. The sub-scanning amount at this time is set to 5. Therefore, when shifting to the third main scan, the sub-scan for 5 dots is executed, and then the main scan is performed to form dots. Thereafter, an image is formed in the same manner.
[0076]
The recording in the nozzle block selection mode (FIG. 14) is compared with the recording in the normal mode (FIG. 13). Both can form dots in the same area. In the normal mode, since the image is printed using the constant nozzles # 1 to # 3, the feed amount in the sub-scanning direction is constant. On the other hand, when printing is performed in the nozzle block selection mode, since the combination of nozzles used for dot formation is changed, the sub-scan feed amount is periodically changed.
[0077]
As described above, in the nozzle block selection interlace mode, the order of the used nozzle blocks is (# 1, # 2, # 3) → (# 2, # 3, # 4) → (# 1, # 2, # 3). It was repeated. Further, the amount of sub-scanning in each main scan is set to repeat 1 dot pitch → 5 dot pitch → 3 dot pitch. And 9 dot pitch (1 + 5 + 3) which is the total number of these repeated dot pitches was performed in 3 passes. In this case, the average transport amount in the three passes is a 3-dot pitch. This is consistent with the sub-scan feed amount in the normal mode.
[0078]
FIG. 15 shows how dots are formed in the normal mode at a resolution of 720 DPI (hereinafter referred to as high resolution). The meaning of the symbols in the figure is the same as in FIG. As shown in FIG. 11, in the high-resolution normal mode, six nozzles were selected from the nozzle array having eight nozzles with a nozzle interval of 2 dot pitch to form a nozzle block. These are the six nozzles & 1 to & 6 shown in FIG. Using these nozzles, printing is performed by an overlap method with a scan repetition number of two. In FIG. 15, nozzles & 7 and & 8 that are not used for dot formation are indicated by broken lines.
[0079]
As shown in FIG. 15, if each raster is formed by performing sub-scanning with a constant feed amount of 3 dot pitch, for example, the & 4 nozzles in the first main scan and the & 1 nozzles in the third main scan are sub-scanned. The position in the scanning direction is the same. In this way, each raster can be formed by two different nozzles. In the normal mode, the data constituting each raster is divided into odd and even groups from the left end of FIG. In the data corresponding to the formation of odd-numbered dots, mask data indicating that dots are not formed is set for even-numbered pixels. Conversely, in the data corresponding to the formation of even-numbered dots, mask data is set for odd-numbered pixels. The print image data set in this way is transferred from the data computer 90. Therefore, if the CPU 41 of the printer 22 transfers such data to a location corresponding to each nozzle of the drive buffer 47, printing by the overlap method is realized. As shown in FIG. 15, the nozzles & 1 to & 4 do not actually form dots in the first main scan. In the second main scan, the nozzles & 1 to & 3 do not form dots. This is because a raster formed by these nozzles cannot completely form an adjacent raster, as shown in FIG.
[0080]
FIG. 16 is an explanatory diagram showing how dots are formed in the nozzle block selection interlace mode at high resolution. The meaning of the symbols in the figure is the same as in FIG. The dot recording in this mode will be described with reference to FIG. Since the value 6 is set as the number of used nozzles in FIG. 11, in this mode, the number of nozzles used in all main scans is six. Also, the number of scan repetitions is 2, and an overlap method is employed in which each raster is formed by two main scans as in the normal mode. In the first main scan, nozzles & 1 to & 6 are used. In FIG. 16, nozzles & 7 and & 8 that are not used for dot formation are indicated by broken lines. However, nozzles & 1 to & 4 do not actually form dots for the same reason as in FIG.
[0081]
In the second main scan, nozzles & 2 to & 7 are used. In FIG. 16, nozzles & 1 and & 8 that are not used for dot formation are indicated by broken lines. At this time, as can be seen from FIG. 11, the sub-scan feed amount is set to 1. Therefore, when shifting to the second main scanning, after performing sub-scanning for one dot, main scanning is performed to form dots. In the third main scan, nozzles & 3 to & 8 are used. The sub-scanning amount at this time is set to 1. Accordingly, when shifting to the third main scan, the sub-scan for one dot is executed, and then the main scan is performed to form dots. Thereafter, an image is formed in the same manner. In the high resolution nozzle block selection interlace mode, the nozzle blocks used are (& 1 to & 6) → (& 2 to & 7) → (& 3 to & 8) → (& 3 to & 8) → (& 2 to & 7) → (& 1 to & 6 ).
[0082]
The recording in the nozzle block selection mode (FIG. 16) is compared with the recording in the normal mode (FIG. 15). Both can form dots in the same area. In the normal mode, since the image is printed using the constant nozzles & 1 to & 6, the feed amount in the sub-scanning direction is constant. On the other hand, when printing is performed in the nozzle block selection mode, since the combination of nozzles used for dot formation is changed, the sub-scan feed amount is periodically changed. Specifically, the amount of sub-scanning in each main scan is repeated in the order of 1 dot pitch → 1 dot pitch → 3 dot pitch → 5 dot pitch → 5 dot pitch → 3 dot pitch in accordance with the periodic change of the used nozzle block. It changes with. An 18-dot pitch (1 + 1 + 3 + 5 + 5 + 3), which is the total number of these repeated dot pitches, is performed in each of six passes. In this case, the average sub-scanning amount in 6 passes is 3 dot pitch. This coincides with the sub-scanning amount in the normal mode.
[0083]
According to the printer 22 of the present embodiment described above, when printing is performed in the nozzle block selection mode, it is possible to print an image by performing recording by the interlace method while changing the sub-scanning amount. The feed error that occurs in the sub-scan often changes depending on the feed amount. The error corresponding to the feed amount may appear in a direction where the feed amount is excessive or may appear in a direction where it is too small. Therefore, according to the printer 22 of this embodiment, it is possible to prevent the dot formation position from being shifted in the sub-scanning direction due to accumulation of errors in the sub-scanning. As a result, high-quality printing can be performed without deterioration in image quality due to banding.
[0084]
In the case of performing the interlace with a constant feed amount shown in FIGS. 13 and 15, there are nozzles that are not used for printing. On the other hand, according to the printer 22 of the above embodiment, the nozzle block used for printing changes as described above. In the low resolution, two types of nozzle blocks # 1 to # 3 and # 2 to # 4 are used. In the high resolution, three types of nozzle blocks & 1 to & 6, & 2 to & 7, & 3 to & 8 are used. Accordingly, it is possible to avoid the deviation of the dot forming elements used during printing. As a result, clogging of some nozzles can be prevented.
[0085]
In the above description, for convenience of illustration, the case where eight nozzles are provided has been described as an example. However, the printer 22 of the present embodiment includes 48 nozzles in each head as shown in FIG. The present invention can be realized by any number of nozzles in addition to the number of nozzles. Naturally, any resolution is applicable as well as the resolution in the above embodiment. In addition, the setting of the used nozzle block can be variously set as shown in FIG.
[0086]
In the above embodiment, the number of nozzles used in the nozzle block selection interlace mode is constant. As shown in FIG. 11, the number of nozzles used is 3 for low resolution and 6 for high resolution. On the other hand, the number of used nozzles may be changed. In the above embodiment, the number of scan repetitions is 1 for low resolution and the number of scan repetitions is 2 for high resolution. However, it may be set to a larger value or both may be set to 1. I do not care.
[0087]
FIG. 17 shows how dots are formed when the number of nozzles used is changed. The meaning of the symbols in the figure is the same as in FIG. FIG. 17 shows an example of a head having four nozzles # 1 to # 4 at a pitch of 6 dots in the sub-scanning direction. The number of scan repetitions is 1. The number of nozzles used changes periodically from 4 to 3. When four nozzles are used, nozzles # 1 to # 4 are used. When three nozzles are used, nozzles # 1 to # 3 are used. That is, the used nozzle block was repeated (# 1 to # 4) → (# 1 to # 3). The sub-scanning amount corresponding to the number of nozzles was set to values 2 and 5.
[0088]
Although not shown, in the case of this embodiment, the following two sets of values are stored in the print mode table 12 in FIG.
Number of nozzles used = 4;
Used nozzle block = 1;
Sub-scanning amount = 5;
and
Number of nozzles used = 3;
Used nozzle block = 1;
Sub-scanning amount = 2;
[0089]
In the first main scan, nozzles # 1 to # 4 are used. However, nozzles # 1 and # 2 do not actually form dots for the same reason as in some of the above-described embodiments. Next, after performing sub-scanning for 2 dots, the second main scanning is performed. In the second main scan, nozzles # 1 to # 3 are used. In FIG. 17, the # 4 nozzle that is not used for dot formation is indicated by a broken line. Further, after the sub-scan for 5 dots is executed, the third main scan is performed. In the third main scan, the nozzles # 1 to # 4 are used again. Thereafter, an image is formed in the same manner.
[0090]
Thus, an image can be formed even if the number of nozzles used is changed. By allowing a change in the number of nozzles to be used, the degree of freedom in selecting nozzle blocks is greatly improved. As a result, the nozzle block can be selected so that an effective feed amount is realized by improving the image quality, or the nozzle block can be selected so that the deviation of the nozzles to be used is further reduced. In the above example, the number of nozzles to be used alternately uses two types of values, but various other combinations are possible. Of course, the head is not limited to the nozzle pitch and the number of nozzles described above.
[0091]
In the embodiment described above, a continuous portion of the nozzles provided in the head is selected as a nozzle block, but it is not always necessary to select a continuous portion. For example, in the example shown in FIG. 17, two nozzles # 1 and # 3 among the nozzles # 1 to # 4 may be selected as nozzle blocks.
[0092]
In the above embodiment, the embodiment applied to an ink jet printer having a nozzle as a dot forming element has been described. However, the present invention is not limited to a printing apparatus having a similar dot forming element, such as an impact dot type. The present invention can be similarly applied to printers, thermal printers, thermal transfer printers, and the like. In addition, in the ink jet printer, in addition to the type of printer having the piezoelectric element described in the above embodiment, a printer that discharges ink with bubbles generated by heating the ink by energizing the heater provided in the nozzle, etc. The present invention can be applied to various types of printers.
[0093]
As described above, in the printer 22 of the present invention, the print control process (FIG. 10) is realized by the CPU 41 executing the control software. Therefore, the present invention can also be realized by an aspect as a recording medium on which a program for realizing such control processing is recorded. Such recording media include flexible disks, CD-ROMs, magneto-optical disks, IC cards, ROM cartridges, punch cards, printed matter on which codes such as barcodes are printed, computer internal storage devices (memory such as RAM and ROM) And various computer-readable media such as an external storage device. Further, an aspect as a program supply apparatus that supplies a computer program for realizing a control function of the printing apparatus to a computer via a communication path is also included. These programs may be executed by the computer 90, or may be executed by the control device 40 provided in the printer 22.
[0094]
Although various embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments can be implemented without departing from the spirit of the present invention. For example, part or all of the print control processing described in the above embodiment may be realized by hardware. In the above embodiment, the print control process is executed by the CPU 41 of the printer 22. However, the print control process may be executed by the CPU of the computer 90.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a printing apparatus according to the present invention.
FIG. 2 is an explanatory diagram showing a configuration of software.
FIG. 3 is a schematic configuration diagram of a printer of the present invention.
FIG. 4 is an explanatory diagram showing a schematic configuration of a dot recording head of the printer of the present invention.
FIG. 5 is an explanatory diagram illustrating a principle of dot formation in the printer of the present invention.
FIG. 6 is an explanatory diagram showing an example of nozzle arrangement in the printer of the present invention.
FIG. 7 is an enlarged view of nozzle arrangement in the printer of the present invention and an explanatory diagram showing a relationship with dots to be formed.
FIG. 8 is an explanatory diagram showing an internal configuration of a printer control apparatus.
FIG. 9 is an explanatory diagram showing a state in which a signal for forming dots is sent to the head.
FIG. 10 is a flowchart illustrating a flow of a print control processing routine.
11 is an explanatory diagram showing the contents of a print mode table 12. FIG.
FIG. 12 is an explanatory diagram showing a correspondence relationship between resolution and nozzles.
FIG. 13 is an explanatory diagram showing how dots are formed in a normal mode at a low resolution.
FIG. 14 is an explanatory diagram showing how dots are formed in the nozzle block selection interlace mode at low resolution.
FIG. 15 is an explanatory diagram showing how dots are formed in a normal mode at high resolution.
FIG. 16 is an explanatory diagram showing how dots are formed in a nozzle block selection interlace mode at high resolution.
FIG. 17 is an explanatory diagram showing how dots are formed in the nozzle block selection interlace mode when the number of nozzles to be used is changed.
FIG. 18 is an explanatory diagram showing how dots are recorded by the interlace method.
[Explanation of symbols]
[Explanation of symbols]
1. Print mode setting section
2 ... Drive unit control unit
3 ... main scanning drive unit
4. Sub-scanning drive unit
5. Print head drive unit
6: Raster data storage
12 ... Print mode table
15 ... Flexible drive
16 ... CD-ROM drive
18 ... modem
22 Color printer
23 ... Paper feed motor
24 ... Carriage motor
26 ... Platen
28 ... Print head
31 ... Carriage
32 ... Control panel
34 ... Sliding shaft
36 ... Drive belt
38 ... pulley
39 ... Position detection sensor
40 ... Control circuit
41 ... CPU
42 ... Programmable ROM (PROM)
43 ... RAM
44 ... PC interface
45. Peripheral input / output unit (PIO)
46 ... Timer
47 ... Drive buffer
48 ... Bus
51 ... Transmitter
55 ... Distribution output device
61, 62, 63, 64, 65, 66... Ink ejection head
67 ... Introducing pipe
68 ... Ink passage
71 ... cartridge for black ink
72. Color ink cartridge
90 ... Personal computer

Claims (12)

A sub-scan that drives the head to form a raster that is a dot row aligned in one direction of the print medium, and moves the print medium relative to the head in one direction that intersects the raster each time the raster is formed. A printing device for printing an image,
The head is a head provided with a plurality of dot forming elements that form dots on the print medium arranged in the sub-scanning direction;
Selecting means for selecting at least one dot-forming element among the plurality of dot-forming elements as an effective element to be used for dot formation at least once after starting printing of the image;
The sub-scan feed amount Q after the selection is set according to the positional relationship between the dot formation element that has been used for dot formation before the selection and the dot formation element that is used for dot formation after the selection. Feed amount setting means to perform,
Sub-scanning means for performing the sub-scanning with the set feed amount; and print head driving means for driving only the selected dot forming element among the dot forming elements to form dots ;
With
The printing apparatus , wherein among the dot formation elements, elements used for dot formation change in a predetermined order, and the sub-scan feed amount changes in a predetermined order . The printing apparatus according to claim 1,
An effective element selected by the selecting means is a printing device that is a continuous dot forming element. The printing apparatus according to claim 1,
Among the dot forming elements, a printing apparatus in which the number of elements used for dot formation is a predetermined number N. The printing apparatus according to claim 3, wherein
The plurality of dot forming elements provided in the head are arranged at a predetermined pitch in the sub-scanning direction between adjacent dot forming elements.
A sub-scan feed amount Q set by the feed amount setting means is a feed amount given in units of a dot recording pitch in the sub-scan direction according to the following equation.
Q = N−k (ji)
Here, k is a value representing the interval in the sub-scanning direction of the dot forming elements in units of the dot recording pitch in the direction,
i is positioned at one end of the dot forming elements used for dot formation before the selection when the element numbers are given from one end of the array of the dot forming elements with the sub-scanning direction as the normal order. Element number of the element,
j is an element number of an element located at an end corresponding to one of the dot forming elements used for dot formation after the selection. The printing apparatus according to claim 1,
A printing apparatus in which the number of elements used for forming dots among the dot forming elements changes in a predetermined order. The printing apparatus according to claim 1,
The print head driving means is means for dividing each raster into two or more predetermined times S across the sub-scan,
The feed amount setting means is a means for setting the sub-scan feed amount after the selection in accordance with the dot forming elements used for dot formation before and after selection and the number of divisions S of each raster. apparatus. The printing apparatus according to claim 6,
Among the dot forming elements, a printing apparatus in which the number of elements used for dot formation is a predetermined number N. The printing apparatus according to claim 7, wherein
The plurality of dot forming elements provided in the head are arranged at a predetermined pitch in the sub-scanning direction between adjacent dot forming elements.
A sub-scan feed amount Q set by the feed amount setting means is a feed amount given in units of a dot recording pitch in the sub-scan direction according to the following equation.
Q = (N / S) -k (ji)
here,
k is a value representing the interval in the sub-scanning direction of the dot forming element in units of the recording pitch of the dots in the direction,
i is positioned at one end of the dot forming elements used for dot formation before the selection when the element numbers are given from one end of the array of the dot forming elements with the sub-scanning direction as the normal order. Element number of the element,
j is an element number of an element located at an end corresponding to one of the dot forming elements used for dot formation after the selection. The printing apparatus according to claim 6,
A printing apparatus in which the number of elements used for forming dots among the dot forming elements changes in a predetermined order. A sub-scan that drives the head to form a raster that is a dot row aligned in one direction of the print medium, and moves the print medium relative to the head in one direction that intersects the raster each time the raster is formed. A printing device for printing an image,
The head is a head provided with a plurality of nozzles for forming dots on the print medium arranged in the sub-scanning direction,
A memory storing data for selecting at least some of the plurality of nozzles as effective nozzles for forming dots at least once after printing of the image is started;
The sub-scan feed amount after the selection is set according to the combination of nozzles used for dot formation before the selection and the combination of nozzles used for dot formation after the selection. A sub-scanning controller that performs the sub-scanning with a feed amount;
A print head controller for forming dots only by driving the nozzle that is selected based on the data stored in said memory of said nozzle,
With
The printing apparatus according to claim 1, wherein the sub-scan feed amount changes in a predetermined order as a combination of nozzles used for forming dots among the nozzles changes in a predetermined order . A sub-scan that drives the head to form a raster that is a dot row aligned in one direction of the print medium, and moves the print medium relative to the head in one direction that intersects the raster each time the raster is formed. Of the printing methods for printing images,
A printing method for printing an image using a head comprising a plurality of dot forming elements for forming dots on the print medium arranged in the sub-scanning direction,
(A) at least once after starting the printing of the image, selecting at least some of the plurality of dot forming elements as effective elements for forming dots; and
(B) Sub-scan feed amount after the selection according to the positional relationship between the dot formation element that has been used for dot formation before the selection and the dot formation element that is used for dot formation after the selection A process of setting
(C) performing the sub-scanning with the set feed amount;
(D) driving only the selected dot forming element among the dot forming elements to form dots ;
With
The printing method , wherein among the dot formation elements, the elements used for dot formation change in a predetermined order, and the sub-scan feed amount changes in a predetermined order . Record for recording a computer-readable program for controlling sub-scanning in which a printing medium is moved relative to the head in one direction with respect to a printing apparatus having a head having a plurality of dot forming elements for forming dots A medium,
A function of selecting at least a part of the plurality of dot forming elements as effective elements to be used for dot formation at least once after printing an image;
The sub-scan feed amount after the selection is set according to the positional relationship between the dot forming element used for dot formation before the selection and the dot forming element used for dot formation after the selection. function and,
Among the dot forming elements, a function for changing the elements used for dot formation in a predetermined order, and a function of changing the sub-scan feed amount in a predetermined order accordingly.
A recording medium on which a program for realizing the above is recorded.

Images