JP2001334654A - Adjustment of positional shift between dots formed at different timing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance print image quality by adjusting relative positional shift between dots formed at different timings accurately. SOLUTION: A patch type test pattern is employed for adjusting positional shift between first and second dots formed at different timings. In the test pattern, the ratio of a part where first and second dots are arranged in main or sub-scanning direction may be intentionally higher than the ratio of a part where first dots or second dots are arranged. Alternatively, same number of first and second dots may be mixed at the substantially same variance over the substantially entire test pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to adjustment of a shift in formation position between dots formed at different timings.

[0002]

2. Description of the Related Art In recent years, as an output device of a computer,
2. Description of the Related Art Ink jet printers that perform printing by discharging ink from a print head have been widely used. 2. Description of the Related Art In the inkjet printer, there is a type in which dots are formed on a print medium by ejecting a plurality of colors of ink while reciprocating a print head with respect to the print medium as a main scan. Further, there is a type in which dots are formed by both reciprocating movements of main scanning (bidirectional printing) in order to improve printing speed.

In these printers, in order to print a high-quality image, when there are a plurality of nozzles having different positions in the main scanning direction, ink is ejected so that dots are formed at predetermined positions. Timing has been adjusted. Further, in the case of performing bidirectional printing, a dot formed at the time of the forward movement of the main scanning (hereinafter, referred to as a forward dot) and a dot formed at the time of the backward movement (hereinafter, referred to as a backward dot) are each a predetermined number. The ink ejection timing is adjusted so as to be formed at the position. This adjustment is performed using a predetermined test pattern.

FIG. 23 is an explanatory diagram showing a test pattern for adjusting a conventional dot shift. This test pattern is for adjusting the deviation between the formation positions of the forward dot and the return dot in bidirectional printing. In the test pattern shown in FIG. 23, vertical ruled lines (upper ruled lines) formed by forward dots are printed according to a predetermined timing signal. The vertical ruled lines (lower ruled lines) of ruled line numbers 1, 2, 3,... By the return dots are printed in accordance with timing signals which are shifted stepwise from predetermined timing signals for forming forward dots. The vertical ruled lines formed by forward dots and the vertical ruled lines formed by return dots are printed such that their positions in the main scanning direction partially overlap. Ruled line number 1,
In No. 2, since the drive timing of the print head is early for the return dot, it is shifted to the side (right in this figure) where the return dot lands earlier on the ruled line formed by the forward dot. In the ruled line number 3, the ruled line based on the forward dot and the ruled line based on the return dot match. In addition, after the ruled line number 4, since the drive timing of the print head for the return dot is gradually delayed, the return dot gradually shifts to the side where it lands (left in this figure) with respect to the forward dot. The user selects a ruled line number ("3" in FIG. 23) in which the positions of these vertical ruled lines best match, and discharges ink at the drive timing of the print head corresponding to the ruled line number. adjust. In this specification,
The terms "ink ejection timing" and "print head drive timing" are synonymous.

[0005]

However, the vertical ruled test pattern shown in FIG. 23 tends to make it difficult to determine the dot shift, and the adjustment accuracy of the relative shift of the formation position between dots is insufficient. There was a problem that is.

In recent years, miniaturization of dots has been performed in order to realize high quality printing. As a result, it has become increasingly difficult to accurately adjust the deviation of the dot formation position. In particular, in a printer intended for high image quality, the deterioration in image quality due to this slight shift cannot be overlooked.

When bidirectional printing is performed, a slight shift in the dot formation position often greatly affects image quality.
For example, consider a print head that has the characteristic that dots are formed to be shifted to the left from their original positions on the outward path when main scanning is performed left and right. In the return path, due to the characteristics of the print head, the dots are formed shifted to the right from the original position. As a result, when bidirectional printing is performed, the relative shift between the dots formed on the forward pass and the dots formed on the return pass is the difference that occurs when dots are formed only on one of the forward pass and the return pass. Double. Therefore, in bidirectional printing, the image quality is severely degraded due to the presence of dots whose formation positions cannot be adjusted sufficiently. This is because if a relative displacement of the formation position occurs between a plurality of dots, the image becomes rough and the image quality deteriorates.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a technique for accurately adjusting the relative shift of the formation position between dots formed at different timings to improve print image quality. The purpose is to provide.

[0009]

Means for Solving the Problems and Their Functions and Effects To solve at least a part of the above-mentioned problems, the present invention employs the following means. A first print control device of the present invention includes a print head having a plurality of nozzles for ejecting ink, and a printing unit that forms dots on a print medium by the print head and performs printing at different timings. What is claimed is: 1. A print control apparatus for printing a test pattern for adjusting a shift of a formation position between a first dot and a second dot to be formed, wherein the test pattern has a predetermined recording rate in a predetermined area. Is a patch-like pattern in which dots are formed in the main scanning direction or the sub-scanning direction.
The gist is that the test pattern has a significantly higher ratio of the portion where the dots and the second dot are arranged than the ratio of the portions where the first dots or the second dots are arranged.

The test pattern used in the present invention is a patch-like pattern in which dots are formed in a predetermined area at a predetermined recording rate. The patch-shaped pattern significantly affects the print image quality (roughness) when a shift occurs in the dot formation position. Therefore, it is possible to determine the granularity due to the relative shift of the formation position between dots based on the granularity of a certain area.
For this reason, it is easier to determine the dot deviation as compared with the conventional ruled line pattern. In addition, "at a predetermined recording rate in a predetermined area"
The wording is not limited to the case where dots having a fixed recording rate are formed in a predetermined area. Therefore, the test pattern may be a pattern in which the recording rate changes stepwise. Further, a pattern in which the recording rate changes gradually (gradation) may be used.

The test pattern used in the present invention is:
A test pattern in which the ratio of the portion where the first dots and the second dots are arranged in the main scanning direction or the sub-scanning direction is significantly larger than the ratio of the portion where the first dots or the second dots are arranged. . In order to complete the present invention, the present inventor has proposed that when first dots and second dots formed at different timings are formed adjacent to each other, the first dot and the second dot may be formed when the formation positions between these dots are relatively shifted. And found that the graininess (roughness) of the printed image was conspicuous. Therefore, when there is a relative shift in the formation position between dots, the portion where roughness is noticeable increases significantly. Therefore, it is easy to determine the dot shift.

[0012] According to the above, it is possible to precisely adjust the dot formation position by adjusting the ink ejection timing, thereby improving the print image quality.

In the printing control apparatus of the present invention, the first
The second dot and the second dot may be dots formed by nozzles having different positions in the main scanning direction. The ink ejected from the nozzles at different positions in the main scanning direction may be the same color ink or inks of different hues.

When dots are formed at the same position by ink ejected from nozzles at different positions in the main scanning direction, the timing of ink ejection is adjusted according to the main scanning speed of the print head. In this case, by applying the present invention, the dot formation position can be adjusted with high accuracy.

In the printing control apparatus of the present invention, the first dot is a forward dot formed when the print head moves forward in the main scanning, and the second dot is a forward dot formed by the print head. The return dot may be formed at the time of the return of the scan.

In bidirectional printing, the relative slight displacement of the formation position between the forward dot and the return dot is caused by a difference in print quality compared with unidirectional printing in which printing is performed only during the forward movement of the main scanning. Has a large effect on In this case, by applying the present invention, the formation positions of the forward dot and the return dot can be adjusted with high accuracy, so that the print image quality can be particularly effectively improved.

Further, in the printing control apparatus of the present invention, the test pattern may be a test pattern in which the first dots and the second dots are formed in a checkered arrangement.

By using a test pattern in which the first dots and the second dots are arranged in a checkered pattern, it is easy to determine the granularity due to the relative shift of the formation position between the dots, and to adjust the ink ejection timing. Adjustment can be made easier. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

In the printing control apparatus according to the present invention, it is preferable that the predetermined recording rate in the test pattern is a recording rate corresponding to a halftone.

An image having a half tone, that is, a tone near the middle of the tone range reproducible by a printing apparatus, has a greater effect on print quality and has a higher granularity than a high tone or low tone image. Easy to distinguish. Therefore, by using a halftone image as a test pattern, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

Further, in the print control apparatus of the present invention, the print head can discharge inks of different hues, and the test pattern is different from the first dot and the second dot. A test pattern formed using hue ink and formed in a state where the first dots and the second dots partially overlap with each other may be used.

When the first dot and the second dot having different hues partially overlap, a portion having a different hue from the first dot and the second dot is generated. Therefore,
When the dot formation position is displaced, the variation in hue inside the test pattern becomes large. By using dots formed of inks having different hues for the test pattern, it is possible to easily determine the granularity due to the relative shift of the formation position between the dots and to easily adjust the ink ejection timing. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

Further, in the printing control apparatus of the present invention, the print head can discharge inks of different hues, and the first dot is a forward dot formed when the print head moves forward in a main scan. Wherein the second dot is a return dot formed when the print head moves in the main scanning direction, and the test pattern uses a plurality of color inks for both the forward dot and the return dot. A test pattern may be formed.

As described above, in the test pattern, by forming both the forward dot and the return dot using a plurality of colors of ink of different hues, it is easy to determine the granularity due to the relative displacement of the formation position between the dots. In addition, it is possible to easily adjust the ink ejection timing. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

According to a second aspect of the present invention, there is provided a print control apparatus including a print head having a plurality of nozzles for discharging ink, and performing printing by forming dots on a print medium using the print head. A print control device for printing a test pattern for adjusting a displacement of a formation position between a first dot and a second dot formed at different timings, wherein the test pattern has a predetermined area Is a patch-like pattern in which dots are formed at a predetermined recording rate, and almost the same number of first dots and second dots are mixed and formed with substantially the same dispersity over substantially the entirety. The gist is that it is a test pattern.

The test pattern used in the present invention is a patch-like pattern in which dots are formed in a predetermined area at a predetermined recording rate, and almost the same number of the first and second dots are formed over almost the entire area. Are test patterns formed in a mixed manner with substantially the same dispersibility. The present inventors have also found that if the first dots and the second dots formed at different timings are mixed and formed with the same number and substantially the same dispersibility, the formation positions between these dots are shifted. In some cases, they found that the roughness was noticeable. Even with such a test pattern, it is possible to easily determine the granularity due to the relative shift of the formation position between dots, and to easily adjust the ink ejection timing. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved. Note that "almost all over" means that the condition regarding the dispersibility and the ratio need not be satisfied in a very small part of the region. Also,
“Equal number of first dots and second dots” means that the first dots and the second dots do not have to be exactly the same number.

According to a third aspect of the present invention, there is provided a print control apparatus including a print head having a plurality of nozzles for ejecting ink, and performing a main scan and a sub scan of the print head relative to a print medium. A print mode setting unit for setting a print mode, the print mode setting unit setting a print mode, and printing a predetermined test pattern as the print mode. A print control unit that controls the printing unit to perform main scanning and sub scanning in a mode different from the modes other than the test pattern mode when the test pattern mode is set. Make a summary.

Generally, the arrangement of the first and second dots filling the print area changes depending on the driving of the print head during printing and the amount of sub-scan feed. The present inventor has found that due to this arrangement, when the dot formation position is shifted, there is a mode in which the roughness is conspicuous and a mode in which the roughness is relatively low. From the viewpoint of improving the print image quality, it is desirable that roughness is less noticeable when printing normal characters and natural images. On the other hand, when printing the test pattern, it is desirable that the roughness is conspicuous. In the above configuration, the two conditions can be made compatible by selectively using the main scanning and the sub scanning depending on whether or not the test pattern is printed. In addition,
The main scanning and sub-scanning modes mean the driving of the print head and the sub-scanning feed amount, and may be referred to as “dot recording system” or “recording system” in this specification.

The present invention further comprises a print head having a plurality of nozzles for ejecting ink, in addition to the configuration as the print control device described above, and performs printing by forming dots on a print medium by the print head. A printing device including a printing unit and the above-described printing control device can also be configured.

Further, the present invention can be configured as an adjustment method for adjusting a dot shift described below.
That is, the first adjustment method of the present invention includes a print head having a plurality of nozzles for discharging ink, and uses a printing unit that performs printing by forming dots on a print medium by the print head. An adjustment method for adjusting a shift of a formation position between a first dot and a second dot formed at a timing, wherein (a) driving the print head at a plurality of different timings determined in advance. By
A step of printing a plurality of test patterns so as to detect a shift in the formation position between the first dot and the second dot; and (b) an optimum test from the plurality of printed test patterns. A step of selecting a pattern; and (c) setting a drive timing of the print head corresponding to the selected test pattern. In the step (a), the test pattern has a predetermined area. It is a patch-like pattern in which dots are formed at a predetermined recording rate, and the ratio of the portion where the first dots and the second dots are arranged in the main scanning direction or the sub-scanning direction is such that the first dots are This is an adjustment method in which the test pattern is a test pattern that is significantly more than the ratio of the portion where the second dots are arranged.

With this adjustment method, it is possible to easily determine the granularity due to the relative shift of the dot formation position, and to easily adjust the ink ejection timing.
As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

A second adjustment method according to the present invention includes a printing head having a plurality of nozzles for ejecting ink, and a printing unit for printing by forming dots on a printing medium by the printing head. An adjustment method for adjusting a shift of a formation position between a first dot and a second dot formed at different timings by using (a) controlling the print head at a plurality of predetermined different timings. A step of printing a plurality of test patterns so as to be able to detect a displacement of a formation position between the first dot and the second dot by driving; and (b) printing the plurality of test patterns. Selecting an optimum test pattern from among them; and (c) setting a drive timing of the print head corresponding to the selected test pattern, wherein the step (a) In the test pattern,
This is a patch-like pattern in which dots are formed in a predetermined area at a predetermined recording rate.
This is a test pattern in which a dot and a second dot are test patterns formed in a mixed manner with substantially the same dispersibility.

According to this adjustment method, it is also possible to easily determine the granularity due to the relative shift of the dot formation position, and to easily adjust the ink ejection timing. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

A third adjustment method of the present invention includes a printing head having a plurality of nozzles for ejecting ink, and a printing unit for printing by forming dots on a printing medium by the printing head. An adjustment method for adjusting a shift of a formation position between a first dot and a second dot formed at different timings by using (a) a step of inputting an instruction as to whether or not to execute adjustment (B) when an instruction to execute the adjustment is input, a predetermined test pattern formed by main scanning and sub-scanning in a mode different from that in normal printing is set in advance by setting the drive timing of the print head. (C) selecting an optimum test pattern from the plurality of printed test patterns, and (d) selecting the optimum test pattern from the plurality of printed test patterns. And a step of setting the drive timing of the print head corresponding to the test pattern is a is an adjustment method.

Also according to this adjustment method, it is possible to easily determine the granularity due to the relative shift of the dot formation position, and to easily adjust the ink ejection timing. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

Further, the present invention can be configured as a recording medium described below. That is, the first recording medium of the present invention is a recording medium in which a computer program for controlling the above-described printing apparatus is recorded in a computer-readable manner, and causes the computer to realize the functions of the above-described printing control apparatus. Computer-readable recording medium on which a computer program for recording is recorded.

When this program is executed, the above-described print control device, printing device, and adjustment method can be realized.

Further, the second recording medium of the present invention includes a print head having a plurality of nozzles for discharging ink, and a printing unit for forming a dot on the print medium by the print head and performing printing. A recording medium in which print data for controlling is recorded in a computer readable manner,
This is a computer-readable recording medium that records print data for printing a test pattern used in the above-described print control device.

This print data is sent to the print control device described above,
By printing the test pattern using the printing apparatus and the adjustment method, it is possible to easily determine the granularity due to the relative shift of the formation position between dots, and to easily adjust the ink ejection timing. As a result, the dot formation position can be adjusted with high accuracy, and the print quality can be improved.

The present invention can be configured as a test pattern and a test pattern printing method in addition to the above-described configuration as the print control device, the printing device, and the adjusting method. Further, the present invention can be realized in various forms such as a computer program for realizing the above, a recording medium on which the program is recorded, and a data signal including the program and embodied in a carrier wave. In each embodiment, the various additional elements described above can be applied.

When the present invention is configured as a computer program or a recording medium on which the program is recorded, the present invention may be configured as a print control device or an entire program for driving the printing device, or may fulfill the functions of the present invention. Only a part may be constituted. As a recording medium, a flexible disk or a CD-RO
M, a magneto-optical disk, an IC card, a ROM cartridge, a punched card, a printed matter on which a code such as a barcode is printed, a computer internal storage device (RAM or ROM)
And a computer-readable medium such as an external storage device.

[0042]

Embodiments of the present invention will be described below in the following order based on examples. A. Configuration of printing device: Print control: First Embodiment: D. First Embodiment Modification of First Embodiment: Second embodiment F. Modification:

A. FIG. 1 is a block diagram showing the configuration of a printing system according to an embodiment of the present invention. The printer PRT is connected to the computer PC, receives print data generated by the printer driver 80 in the computer PC, and executes printing. The print data contains dots on / off for each pixel on the raster.
Raster data specifying OFF and sub-scan feed amount data specifying the sub-scan feed amount are included. Computer PC
Is connected to an external network TN, and can be connected to a specific server SV to download programs and data for driving the printer PRT. Further, it is possible to load necessary programs and data from a recording medium such as a flexible disk or a CD-ROM by using the flexible disk drive FDD or the CD-ROM drive CDD. These programs may take a form in which the entire program necessary for printing is loaded collectively, or a form in which some functions are loaded as a module.

In the computer PC, an application program (not shown) operates under a predetermined operating system. The application program performs processing such as image generation and retouching. A printer driver 80 is incorporated in the operating system. The printer driver 80 corresponds to a program for realizing a function of generating print data including sub-scan feed amount data and raster data indicating a dot recording state at each main scan.

The printer driver 80 receives image data from the application program and generates print data to be supplied to the printer PRT. Inside the printer driver 80, a print mode setting unit 82,
A print mode control unit 84 and three print data generation units 8
6,87,88.

In the present embodiment, the print mode setting section 82
A text print mode for printing characters, a natural image print mode for printing a natural image, or a test pattern print mode for printing a test pattern is set. The print mode control unit 84 generates print data for character printing, print data for natural image printing, or prints a test pattern according to the print mode set by the print mode setting unit 82. It is determined whether to generate print data for printing. The first print data generator 86 generates print data for text printing. Second print data generation unit 87
Generates print data for natural image printing. The third print data generation unit 88 is prepared with image data for printing a patch-like test pattern having a constant gradation value in advance. The third print data generation unit 88 generates print data for test pattern printing by performing halftone processing on the image data. Although the tone value of the test pattern can be set arbitrarily, in the present embodiment, the tone value is set to halftone.

The three print data generators 86, 87, 88
Has a resolution conversion module, a color conversion module,
A halftone module and an interlace data generation module are provided (not shown). Also, a color conversion table is provided. The resolution conversion module converts the resolution of the color image data handled by the application program into a resolution that the printer driver 80 can handle. The color conversion module refers to the color conversion table and uses cyan (C), light cyan (LC), magenta (M), light magenta (LM), yellow (Y), black ( K) is converted into multi-tone data of each color. The halftone module performs a halftone process of expressing the gradation value of the image data by a dot distribution. The interlace data generation module arranges the halftone processed image data together with the sub-scan feed amount data in a predetermined format to be transferred to the printer PRT. Note that a part of the processing performed in the printer driver 80 is partially
May be performed.

A program for realizing the function of each module of the printer driver 80 is supplied in a form recorded on a computer-readable recording medium. Such recording media include flexible disks and CDs.
-ROMs, magneto-optical disks, IC cards, ROM cartridges, punched cards, printed matter on which codes such as bar codes are printed, and internal storage devices (RAM and R
Various computer-readable media can be used, such as a memory (such as an OM) and an external storage device.

The printer PRT includes an input unit 91, a buffer 92, a main scanning unit 93, a sub-scanning unit 94, a head driving unit 95, and a driving timing table 96. The input unit 91 receives the print data transferred from the printer driver 80. This print data is temporarily stored in the buffer 92. Then, the buffer 92
The main scanning unit 93 and the sub-scanning unit 94 perform the main scanning of the print head and transport the printing paper in accordance with the print data stored in the storage unit, and the head driving unit 95 refers to the driving timing set in the driving timing table 96. The print head is driven to print an image. Note that the printer PRT is
The printer is capable of bidirectional printing.

FIG. 2 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 mechanism for controlling ink ejection and dot formation by driving the paper feed motor 23, the carriage motor 24, the print head 28, and the operation panel 3.
And a control circuit 40 which controls the exchange of signals with the control circuit 2.

The mechanism for reciprocating the carriage 31 in the axial direction of the platen 26 is provided in parallel with the axis of the platen 26, and is provided between a carriage shaft 24 and a slide shaft 34 for slidably holding the carriage 31. And a position detecting sensor 39 for detecting the origin position of the carriage 31.

On the carriage 31, a cartridge 71 for black ink and a cartridge 72 for color ink containing five color inks of cyan, light cyan, magenta, light magenta and yellow can be mounted. The light cyan ink has substantially the same hue as the cyan ink and has a lower density than the cyan ink. The same applies to light magenta ink. Carriage 3
A total of six ink discharge heads 61 to 66 corresponding to these inks are formed on the print head 28 below the print head 28. At the bottom of the carriage 31, an introduction pipe for guiding ink from the ink tank to each color head is provided upright.

FIG. 3 is an explanatory diagram showing the arrangement of the nozzles Nz in the ink discharge heads 61 to 66. These ink ejection heads 61 to 66 have black ink (K), cyan ink (C), light cyan ink (LC), magenta ink (M), light magenta ink (LM), and yellow, respectively. Nozzles Nz for ejecting six colors of ink with ink (Y) are provided. The positions of the ink ejection heads 61 to 66 in the sub-scanning direction coincide with each other. In addition, the ink ejection head 6
1 to 66 are constant nozzle pitches k along the sub-scanning direction.
And 48 nozzles Nz arranged in a zigzag pattern. The nozzles Nz are arranged in a staggered manner so that the nozzle pitch can be easily set small in manufacturing.
They may be arranged on a straight line.

FIG. 4 is an explanatory diagram showing the internal configuration of the control device 40. As illustrated, inside the control device 40,
Various circuits described below, centering on the CPU 41, the PROM 42, and the RAM 43, are mutually connected by a bus 48. P
The C interface 44 exchanges data with the computer 90. The peripheral input / output unit (PIO) 45 exchanges signals with the paper feed motor 23, the carriage motor 24, the operation panel 32, and the like. The clock 46 synchronizes the operation of each circuit. The driving buffer 47 is a head 6
The on / off signals of the dots for each nozzle are output to the drive signal generation unit 55 at 1 to 66.

The oscillator 50 is connected to the drive signal generator 55. The oscillator 50 periodically outputs a clock signal serving as a reference for generating a drive signal. The drive signal generation unit 55 is configured to output the signals from the heads 61 to
A drive waveform to be output to each of the 66 nozzle arrays is generated. As already shown, the heads 61 to 66 are provided with a plurality of nozzle rows at different positions in the main scanning direction. The drive signal generation unit 55 outputs a drive signal at an output timing at which dots can be appropriately formed in each pixel in consideration of such a difference in position. Since the printer PRT is capable of bidirectional printing, the output timing is separately determined for the forward and backward movements of the main scan in the drive timing table 9 in the PROM 42.
6 (see FIG. 1).

FIG. 5 is an explanatory diagram showing generation of the reference print timing signal PTS. The print timing signal is a signal output corresponding to each pixel, and is a signal for instructing the start of a drive waveform. As shown in the figure, the printer PRT includes a linear scale in which black portions are uniformly attached at predetermined intervals in parallel with a slide shaft 34 that slidably holds the carriage 31. In this embodiment, the width of the black portion is twice the resolution of the printer PRT, that is, 360D.
It corresponds to the interval of PI. The carriage 31 is an optical sensor 7
3 is provided. The optical sensor 73 outputs an ON / OFF signal according to whether or not the surface facing the sensor is a black portion when the carriage 31 moves. The state of this signal is shown in the figure. With this pulse, the control device 40 can detect the position of the carriage 31 in the main scanning direction.

By equally dividing the pulse output from the optical sensor 73, the position of the carriage 31 can be detected with a resolution higher than that of the black portion. If the pulse interval is divided into two equal parts, the position of the carriage 31 can be detected with a resolution of 720 DPI. In the signal thus obtained, the relationship between the carriage 31 and the pixels is kept constant. When printing is performed at 720 DPI, the signal obtained in this manner becomes the reference print timing signal PTS. The figure shows an example of the reference print timing signal PTS corresponding to 720 DPI. The reference print timing signal PTS may be generated by using an optical sensor as described above, or may be generated so as to be output at a constant time period from the start of main scanning. However, if the signal is generated using an optical sensor, a signal with higher accuracy can be generated.

FIG. 6 shows the reference print timing signal PTS.
FIG. 4 is an explanatory diagram showing a relationship between the print timing signal and a delayed print timing signal. Although not shown, the delayed print timing signal is generated by applying a delay signal to the reference print timing signal PTS. The printer 22 includes a plurality of print timing signals PTS (0), PTS (1), PTS delayed from the reference timing signal PTS.
It is possible to drive the print head using (3),.

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 conveyed by the paper feed motor 23. At the same time, the piezo elements of the ink discharge heads 61 to 66 of the print head 28 are driven to discharge ink droplets of each color, thereby forming ink dots and forming a multi-color and multi-tone image on the paper P.

B. Print Control: FIG. 7 is a flowchart of a print mode control routine. This is a process executed by the CPU in the computer PC. When this process is started, first, the print mode is set (step S
100). If the set print mode is the text print mode (step S120), print data for text is generated (step S140). If the set print mode is the natural image print mode (step S12)
0), print data for a natural image is generated (step S160). If the set print mode is the test pattern print mode (step S120), print data for the test pattern is generated (step S180).

As described above, these print data include raster data for specifying on / off of dots for each pixel on the raster and sub-scan feed amount data for specifying the sub-scan feed amount. . The printer PRT receives these data and executes printing.

FIG. 8 is an explanatory diagram showing a dot recording method in the text print mode. As shown in FIG. 8A, in this printing method, the nozzle pitch k is 6, the number N of used nozzles is 47, and the number of scan repetitions s is 2. In addition, the lower table of FIG. 8A shows parameters relating to each of the first to thirteenth passes. One cycle is
This includes 12 (= ks) sub-scans. Twelve sub-scans are completed by repeating six sub-scans with a feed amount of (21, 26) dots six times. Also,
In the horizontal position shown at the bottom of FIG. 8A, when the horizontal position is “1”, the odd-numbered pixels of each raster line are recorded in the pass, and when the horizontal position is “2”, the even-numbered pixels are recorded. Means to record.

FIG. 8B shows the nozzle numbers used for dot printing on each raster line in each pass, corresponding to each pass number in FIG. 8A. The line numbers of the respective raster lines shown on the left end are consecutive numbers within the effective recording range. When the pass number is odd, dot recording is performed when the print head moves forward, and when the pass number is even, dot recording is performed when moving backward. As can be seen from this figure, a plurality of dots on each raster line are formed using two different nozzles depending on both the forward and backward movements of the main scan of the print head.

The right side of FIG. 8B shows the relationship between the paths forming the raster lines of raster numbers 2 to 7 and the horizontal position. Since k = 6 and s = 2 in the text print mode, the dots of the entire image are arranged in a uniform order in units of a total of 12 pixels of 2 pixels in the main scanning direction and 6 pixels in the sub-scanning direction. It is formed. The horizontal position 1 represents an odd-numbered pixel position, and the horizontal position 2 represents an even-numbered pixel position. The numbers in the cells represent the pass numbers. As shown in the drawing, in the rasters of raster numbers 2 to 7, odd-numbered pixels are paths 1, 11, 9, 7,
5 and 3 respectively, and the even-numbered pixels are
6, 4, 2, 12, and 10, respectively. In other words, the odd-numbered pixels of each raster line are recorded using forward dots, and the even-numbered pixels are recorded using return dots. Further, by making the horizontal positions of the dots formed in the continuous main scanning different as described above, even when dots having a large diameter are formed in each pixel, the dots can be made difficult to overlap. FIG. 10A shows the state of dots recorded by this recording method. ○ indicates an outgoing dot. Also, ● indicates a double dot.

FIG. 9 is an explanatory diagram showing a dot recording method in the natural image printing mode. As shown in FIG. 9A, in this printing method, the nozzle pitch k is 6, the number N of used nozzles is 48, and the number of scan repetitions s is 2. In addition, the table at the bottom of this figure shows parameters relating to each pass from the first to thirteenth passes. In the 12 (= ks) sub-scans constituting one cycle, the feed amount is (20,
(27,22,28,21,26) Six sub-scans, which are dots, are completed by repeating twice. FIG.
In the horizontal position shown at the bottom of 1 (A), when the horizontal position is “1”, the odd-numbered pixels of each raster line are recorded in the pass, and when the horizontal position is “2”, the even-numbered pixels are recorded. It means to do.

FIG. 9B shows nozzle numbers used for dot printing on each raster line in each pass, corresponding to each pass number in FIG. 9A. The line numbers of the respective raster lines shown on the left end are consecutive numbers within the effective recording range. When the pass number is odd, dot recording is performed when the print head moves forward, and when the pass number is even, dot recording is performed when moving backward. As can be seen from this figure, rasters formed by the forward movement and rasters formed by the backward movement are alternately arranged in a bundle of three rasters. A plurality of dots on each raster line are formed using two different nozzles depending on the forward or backward movement of the main scan of the print head.

The right side of FIG. 9B shows the relationship between the paths forming the raster lines of raster numbers 2 to 7 and the horizontal position. In the comparative example, since k = 6 and s = 2, the dots of the entire image are formed in a uniform order in units of a total of 12 pixels of 2 pixels in the main scanning direction and 6 pixels in the sub-scanning direction. Is done. The horizontal position 1 represents an odd-numbered pixel position, and the horizontal position 2 represents an even-numbered pixel position. The numbers in the cells represent the pass numbers. As shown, in the rasters of raster numbers 2 to 7, odd-numbered pixels are recorded in passes 1, 5, 8, 10, 12, and 3, respectively, and even-numbered pixels are printed in passes 7, 11, 12, 4, and 4.
Record at 6 and 9, respectively. In other words, for raster numbers 2, 3, and 7, the odd-numbered pixels of each raster line are:
Recording is performed in the first main scan, and even-numbered pixels are recorded in the second main scan. For raster numbers 4, 5, and 6, the odd-numbered pixels of each raster line are recorded in the second main scan, and the even-numbered pixels are recorded in the first main scan. Further, by making the horizontal positions of the dots formed in the continuous main scanning different as described above, even when dots having a large diameter are formed in each pixel, the dots can be made difficult to overlap. FIG. 10B shows the state of dots recorded by this recording method. ○ indicates an outgoing dot. Also, ● indicates a double dot.

C. First Embodiment FIG. 11 is an explanatory diagram showing a dot recording method in a test pattern print mode as a first embodiment. As shown in FIG. 11A, in this printing method, the nozzle pitch k is 6, and the number N of used nozzles is 4.
7. The number of scan repetitions s is 2. FIG.
The table below (A) shows the parameters for each pass from the first to the thirteenth pass. One cycle is 1
2 (= ks) sub-scans are included. Twelve sub-scans are completed by repeating six sub-scans with a feed amount of (21, 26) dots six times. The horizontal position shown at the bottom of FIG. 11A records the odd-numbered pixel of each raster line in the pass when the horizontal position is “1”, and the even-numbered pixel when the horizontal position is “2”. This means recording pixels.

FIG. 11B shows nozzle numbers used for dot printing on each raster line in each pass, corresponding to each pass number in FIG. 11A. The line numbers of the respective raster lines shown on the left end are consecutive numbers within the effective recording range. When the pass number is odd, dot recording is performed when the print head moves forward, and when the pass number is even, dot recording is performed when moving backward. As you can see from this figure,
A plurality of dots on each raster line are formed using two different nozzles depending on the forward or backward movement of the print head. Further, dots of raster lines adjacent to each other are formed by main scanning in different directions of the print head.

Raster numbers 2 to 7 are shown on the right side of FIG.
The relationship between the path forming each raster line and the horizontal position is shown. In the second embodiment, since k = 6 and s = 2,
The dots of the entire image are formed in a uniform order in units of an area of a total of 12 pixels of 2 pixels in the main scanning direction and 6 pixels in the sub-scanning direction. The horizontal position 1 represents an odd-numbered pixel position, and the horizontal position 2 represents an even-numbered pixel position. The numbers in the cells represent the pass numbers. As shown, in the rasters of raster numbers 2 to 7, the odd-numbered pixels are recorded in passes 1, 6, 9, 2, 5, and 10, respectively, and the even-numbered pixels are recorded in passes 8, 11, 4, and 9.
Record at 7, 12, and 3, respectively. In other words, the forward dots and the backward dots are arranged and printed in a checkered pattern. In addition,
FIG. 12 shows the state of dots recorded by this recording method. ○ indicates an outgoing dot. Also, ● indicates a double dot. In this way, in the bidirectional printing, by arranging the forward dot and the return dot in a checkered pattern, it is possible to easily determine the degree of roughness due to a shift in the dot formation position.

FIG. 13 is a flowchart of the print head drive timing adjustment. First, a test pattern is printed at five timings described later (Step S).
200).

FIG. 14 is an explanatory diagram showing a test pattern. ○ indicates an outgoing dot. Also, ● indicates a double dot. In this embodiment, the forward dot and the backward dot have the same color. The test pattern is recorded by changing the formation timing of the return dot in five stages indicated by numbers 1 to 5 relative to the formation timing of the forward dot. For example, the forward dot is printed using the print timing signal PTS (0) shown in FIG. The return dots of the test patterns 1 to 5 are printed using the print timing signals PTS (1) to PTS (5). The drive timing for forming the return dot, which is stored in the memory, is the timing of the print timing signal PTS (3), that is, the drive timing for forming the forward dot, which is three times different from the drive timing. And In the test pattern 1, the return dot is shifted to the side (right in this figure) where the return dot lands earlier than the forward dot because the print timing is earlier. In the test pattern 2, the return dots are formed at appropriate timing. This means that the current return dot formation timing is one stage later. Also, test pattern 3,
In 4 and 5, since the printing timing of the return dot is gradually delayed, the return dot gradually shifts toward the landing side (left in this figure) with respect to the forward dot. Test patterns 1, 3, 4,
When the relative formation positions of the forward dot and the backward dot are shifted as in 5, a blank portion is generated between the dots, and a rough feeling and a light and shade pattern are visually recognized. By this effect, it is possible to accurately recognize the deviation of the dot formation position.
Adjusting the dot formation position gives the least roughness
This is performed by the user selecting the pattern 2 formed at the most appropriate timing.

The user selects one of the five printed test patterns having the least roughness, and inputs the number (step S220 in FIG. 13). The drive timing of the print head stored in the drive timing table 96 of FIG. 1 is changed to the drive timing corresponding to the input number (step S240). Because the dot formation timing is too far off, the above five test patterns may not be optimally adjusted. In this case, it is determined whether or not to make further adjustment (step S260). If no further adjustment is made, the process is terminated. To make further adjustments, print the test pattern again and repeat the same processing.

In the first embodiment, the test pattern is
A pattern in which forward dots and return dots are arranged in a checkered pattern is used (FIG. 14). This test pattern is a pattern in which the roughness is conspicuous when the formation positions between dots are relatively shifted. Therefore, it is easy to determine the degree of roughness, and it is easy to accurately adjust the drive timing of the print head. Further, since the recording method is switched and used depending on the printing target (text, natural image, test pattern), printing suitable for each can be performed.

D. Modification of First Embodiment: FIG.
FIG. 9 is a block diagram illustrating a configuration of a printing system as a modification of the embodiment. In the modified example, the print data generation unit for test pattern printing (the third print data generation unit 88 in FIG. 1) is not provided in the printer driver 80. Instead, the test pattern data 97 is stored in the printer PRT in advance.
It has. The test pattern data 97 is print data for printing a test pattern. The test pattern data 97 includes raster data for specifying dot on / off for each pixel on the raster and sub-scan feed amount data for specifying the sub-scan feed amount. Contains. When the test pattern printing mode is set as the printing mode, the main scanning unit 93 and the sub-scanning unit 94
And the test pattern data is supplied directly to the head drive unit 95. The test pattern data may be provided in the printer driver 80. The rest is the same as the first embodiment.

E. Second Embodiment In the first embodiment, the case where the forward dot and the return dot are formed with the same ink has been described. In the second embodiment, a case where both are formed with different inks will be described. FIG. 16 is an explanatory diagram of a test pattern according to the second embodiment. In FIG. 16A, cyan ink (C) is used for forward dots, and magenta ink (M) is used for return dots. In FIG. 16B,
The forward dot uses cyan ink (C), and the return dot uses yellow ink (Y). The dot recording method is the same as in the first embodiment shown in FIG.

In the second embodiment, inks of different hues are used for the forward dot and the return dot. When dots of different hues overlap, a portion of a different hue is generated. For example, in the example shown in FIG. 16A, the portion where the cyan dot and the magenta dot overlap
Turns blue. In the example shown in FIG. 16B, the portion where the cyan dot and the yellow dot overlap is green. As described above, if inks of different hues are used for the forward dot and the return dot, the variation of the hue inside the test pattern changes depending on the degree of the deviation of the dot formation position, and the degree of roughness is easily visually recognized. As a result,
Since the dot formation position can be adjusted with high accuracy, the print quality can be improved. In general, yellow ink has low visibility and therefore is difficult to adjust, but according to the present invention, adjustment can be easily performed.

F. Modifications: Several embodiments of the present invention have been described above, but the present invention is not limited to such embodiments at all, and may be implemented in various modes without departing from the scope of the invention. Implementation is possible. For example, the following modifications are possible.

F1. Modification 1 In the above embodiment, the relative shift of the formation position between the forward dot and the return dot in the bidirectional printing is adjusted. However, in general, the present invention employs the first dot and the second dot formed at different timings. Can be applied to the adjustment of the deviation of the formation position between the dots.
Therefore, the present invention is applicable to the adjustment of the relative formation position shift between dots formed by ink ejected from each nozzle row when the print head has a plurality of nozzle rows at different positions in the main scanning direction. Can also be applied. For example, in the print head 28 shown in FIG. 3, the present invention may be applied to the adjustment of the dot formation position formed by the ink ejected from the nozzles of each of the row A and the row B in the illustrated black ink nozzle group. Alternatively, the present invention may be applied to the adjustment of the dot formation position formed by the ink ejected from the nozzles of the rows B and C that eject the inks of different hues. Note that the present invention may be applied to unidirectional printing in which printing is performed only in the forward movement of main scanning.

FIG. 17 is an explanatory diagram showing a print head 28A in which nozzle groups for ejecting six color inks are arranged in the sub-scanning direction. The present invention can be applied to a case where such a print head is used. That is, the present invention may be applied to the adjustment of the dot formation position formed by the ink ejected from the nozzles of the 0th row and the 1st row in each nozzle group, or may be applied to the nozzle groups ejecting inks of different hues from each other. The present invention may be applied to adjustment of a dot formation position formed by ink ejected from a nozzle.

FIG. 18 is an explanatory diagram showing a print head 28B in which six print heads 28 shown in FIG. 3 are arranged in the sub-scanning direction. Even when using such a print head,
The present invention can be applied. Further, the present invention may be applied to a print head having more nozzle groups.

F2. Modified Example 2: In the above-described embodiment, the test pattern is arranged in a checkerboard pattern so that the forward dot and the backward dot are adjacent to each other in the main scanning direction and the sub-scanning direction. However, the present invention is not limited to this. Here,
The term "dots adjacent to each other" does not mean only "dots formed at pixel positions adjacent to each other", but means a state where the formed dots are adjacent to each other. Therefore, it has a meaning including the case where there is a pixel where no dot is formed between the first dot and the second dot.

FIG. 19 is an explanatory diagram showing first dots and second dots arranged in a checkered pattern. ○ indicates the first dot. Also, ● indicates the second dot. In this arrangement, the first dots and the second dots are always arranged in the main scanning direction and the sub-scanning direction. FIGS. 19A, 19B and 19C show examples in which the dot recording rates are different. As described above, in a checkerboard pattern, it is possible to easily determine the roughness due to a shift in the dot formation position even when the dot recording rates are different.

FIG. 20 is an explanatory diagram showing first and second dots arranged in a staggered manner. ○ indicates the first dot. Also, ● indicates the second dot. As surrounded by a broken line in FIG. 20B, the first dots and the second dots are arranged in the main scanning direction and the sub-scanning direction. I have. In addition, FIG.
(B) and (c) show examples in which the dot recording rates are different. Even in this case, it is possible to easily determine the roughness due to the shift of the dot formation position.

FIGS. 19 and 20 show patterns in which the first dots and the second dots are regularly arranged. However, the present invention is not limited to this. FIG. 21 is an explanatory diagram showing first and second dots arranged irregularly. ○ indicates the first dot. Also, ● is the second
Indicates a dot. As shown in FIG.
The first dots and the second dots may be irregularly arranged. A large number of first dots are formed in a small part of the area A surrounded by a broken line, but are mixed irregularly in the area B surrounded by a broken line with almost the same dispersibility. Further, as shown in FIG. 21B, the recording rate may be arranged so as to gradually change. Such a pattern also corresponds to a pattern in which the same number of the first dots and the second dots are mixed and formed with substantially the same dispersibility.

F3. Modification Example 3 In the second embodiment, two colors of cyan ink and magenta ink and two colors of cyan ink and yellow ink are used as inks of different hues.
Although colors are used, other inks may be used. Further, inks of three or more colors may be used.

FIG. 22 shows cyan, magenta, yellow,
FIG. 4 is a perspective view of a red, green, and blue L ^* a ^* b ^* space in a plane perpendicular to the L axis. This figure shows cyan (C) and magenta (M)
And blue (B) when they mix with each other, red (R) when magenta (M) and yellow (Y) mix, and green (G) when yellow (Y) and cyan (C) mix. Is shown. The relationship between cyan (C) and red (R), the relationship between magenta (M) and green (G), and the relationship between yellow (Y) and blue (B) are complementary colors.

As can be understood from FIG. 22, the change in hue in the test pattern can be increased by using three or more colors of ink, so that the sense of roughness due to a shift in dot formation position can be easily recognized. . Also,
It is also effective to use light cyan ink or light magenta ink having relatively low visibility.

F4. Modification 4: In the second embodiment, the forward dot and the backward dot are formed using inks of different hues from each other in the test pattern.
Both the forward dot and the return dot may be formed using a plurality of colors of ink. Even in this case, as in the case of the third modification, the roughness due to the shift in the dot formation position can be easily recognized.

F5. Modification 5: In the above embodiment, the dot formation position is adjusted using a patch-like test pattern, but may be used in combination with a conventional ruled line pattern. For example, rough adjustment may be performed using a ruled line pattern, and fine adjustment may be performed using a patch-like pattern.

F6. Modification 6: In the above embodiment, an inkjet printer using a piezo element is used.
A printer that ejects ink droplets by another method may be used. For example, there is a printer of a type that energizes a heater disposed in an ink passage and discharges ink droplets by bubbles generated in the ink passage.

Since the printing apparatus of the present embodiment described above includes processing by a computer, the printing apparatus according to the present embodiment may be implemented as a recording medium on which a program for realizing the processing is recorded. Examples of such a recording medium include a flexible disk, a CD-ROM, a magneto-optical disk, an IC card, a ROM cartridge, a punched card, a printed matter on which a code such as a barcode is printed, and an internal storage device of a computer (such as a RAM or a ROM). Various computer-readable media, such as memory and external storage, can be used.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a printing system according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a printer 22.

FIG. 3 is an explanatory diagram showing an arrangement of nozzles Nz in ink ejection heads 61 to 66.

FIG. 4 is an explanatory diagram showing an internal configuration of the control device 40.

FIG. 5 is an explanatory diagram illustrating generation of a reference print timing signal PTS.

FIG. 6 is an explanatory diagram showing a relationship between a reference print timing signal PTS and a delayed print timing signal.

FIG. 7 is a flowchart of a print mode control routine.

FIG. 8 is an explanatory diagram showing a dot recording method in a text print mode.

FIG. 9 is an explanatory diagram showing a dot recording method in a natural image printing mode.

FIG. 10 is an explanatory diagram showing a state of dots recorded by a dot recording method in a text print mode and a natural image print mode.

FIG. 11 is an explanatory diagram showing a dot recording method in a test pattern print mode as the first embodiment.

FIG. 12 is an explanatory diagram showing a state of dots recorded by a dot recording method in a test pattern print mode.

FIG. 13 is a flowchart of a print head drive timing adjustment.

FIG. 14 is an explanatory diagram showing a test pattern.

FIG. 15 is a block diagram illustrating a configuration of a printing system as a modification of the first embodiment.

FIG. 16 is an explanatory diagram of a test pattern according to the second embodiment.

FIG. 17 is an explanatory diagram showing a print head 28A in which nozzle groups for ejecting six colors of ink are arranged in the sub-scanning direction.

FIG. 18 is an explanatory diagram showing a print head 28B in which six print heads 28 are arranged in the sub-scanning direction.

FIG. 19 is an explanatory diagram showing dots arranged in a staggered pattern.

FIG. 20 is an explanatory diagram showing dots arranged in a checkered pattern.

FIG. 21 is an explanatory diagram showing dots in another arrangement.

FIG. 22: L for cyan, magenta, yellow, red, green, and blue
It is an oblique view to a plane perpendicular to L axis in ^* a ^* b ^* space.

FIG. 23 is an explanatory diagram showing a test pattern for performing conventional dot shift adjustment.

[Explanation of symbols]

 Reference numeral 22 Printer 23 Paper feed motor 24 Carriage motor 25 Paper feed roller 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 41 CPU 42 PROM 43 RAM 44 PC interface 45 Peripheral input / output unit (PIO) 46 Timer 47 Drive buffer 48 Bus 50 Oscillator 55 Drive signal generator 61-66 Ink ejection Head 71 black ink cartridge 72 color ink cartridge 73 optical sensor 80 printer driver 82 print mode setting unit 84 print mode control unit 86, 87, 88 print data generation unit 91 input unit 92 Buffer 93: main scanning unit 94: sub-scanning unit 95 The head drive unit 96 ... drive timing table

Claims (15)

[Claims] 1. A printing unit, comprising: a print head having a plurality of nozzles for discharging ink, wherein a first printing unit forms dots at different timings on a printing unit by forming dots on a print medium by the print head. What is claimed is: 1. A print control apparatus for printing a test pattern for adjusting a displacement of a formation position between a dot and a second dot, wherein the test pattern has dots formed in a predetermined area at a predetermined recording rate. It is a patch-like pattern, and the ratio of the portion where the first dots and the second dots are arranged in the main scanning direction or the sub-scanning direction is the ratio of the portions where the first dots or the portions where the second dots are arranged. A print control device that is a test pattern that is significantly more than a percentage. 2. The print control device according to claim 1, wherein the first dot and the second dot are dots formed by nozzles having different positions in the main scanning direction. 3. The print control device according to claim 1, wherein the first dot is a forward dot formed when the print head moves forward in a main scan, and the second dot is a forward dot. A print control device, which is a return dot formed when the print head moves back in the main scan. 4. The print control device according to claim 1, wherein the test pattern is a test pattern in which the first dots and the second dots are formed in a checkered arrangement. . 5. The print control apparatus according to claim 1, wherein the predetermined recording rate in the test pattern is a recording rate corresponding to a halftone. 6. The print control device according to claim 1, wherein the print head is capable of ejecting inks of different hues, and the test pattern includes the first dot and the second dot.
Are test patterns formed by using inks of different hues, and the first dot and the second dot are formed in a partially overlapping state.
Print control device. 7. The print control device according to claim 1, wherein the print head is capable of ejecting inks of different hues, and wherein the first dots are formed when the print head moves forward in a main scan. The second dot is a return dot formed when the print head moves back in the main scan, and the test pattern is such that the forward dot and the return dot have a plurality of colors. A print control device, which is a test pattern formed by using the above ink. 8. A printing unit, comprising: a printing head having a plurality of nozzles for discharging ink, wherein a printing unit that forms dots on a printing medium by the printing head and performs printing is formed at different timings. What is claimed is: 1. A print control apparatus for printing a test pattern for adjusting a displacement of a formation position between a dot and a second dot, wherein the test pattern has dots formed in a predetermined area at a predetermined recording rate. It is a patch-like pattern, and almost the same number of first dots and second dots
A print control device, which is a test pattern formed by being mixed with substantially equal dispersibility. 9. A print head having a plurality of nozzles for discharging ink, wherein dots are formed on the print medium while the print head performs main scan and sub scan relative to the print medium. A print control device that controls a printing unit that performs printing, a print mode setting unit that sets a print mode, and when a test pattern mode for printing a predetermined test pattern is set as the print mode,
A print control unit that controls the printing unit to perform printing by performing main scanning and sub-scanning in a mode different from a mode other than the test pattern mode. 10. A printing unit, comprising: a printing head having a plurality of nozzles for discharging ink, wherein the printing unit forms a dot on a printing medium by the printing head and performs printing. A printing device, comprising: the printing control device according to claim 1. 11. A print head having a plurality of nozzles for ejecting ink, the first print head being formed at different timings by using a printing unit that performs printing by forming dots on a print medium by the print head. (A) driving a plurality of test patterns by driving the print head at a plurality of predetermined different timings. A step of printing so as to be able to detect a displacement of a formation position between the first dot and the second dot; and (b) a step of selecting an optimum test pattern from the plurality of printed test patterns. And (c) setting a drive timing of the print head corresponding to the selected test pattern. In the step (a), the test pattern Is a patch-like pattern in which dots are formed at a predetermined recording rate in a predetermined area, and the ratio of the portion where the first dots and the second dots are arranged in the main scanning direction or the sub-scanning direction is: The adjustment method, wherein the test pattern is a test pattern that is significantly more than the ratio of the portion where the first dots or the second dots are arranged. 12. A print head having a plurality of nozzles for ejecting ink, the first print head being formed at different timings by using a printing unit that forms dots on a print medium by the print head and performs printing. (A) driving a plurality of test patterns by driving the print head at a plurality of predetermined different timings. A step of printing so as to be able to detect a displacement of a formation position between the first dot and the second dot; and (b) a step of selecting an optimum test pattern from the plurality of printed test patterns. And (c) setting a drive timing of the print head corresponding to the selected test pattern. In the step (a), the test pattern Is a patch-like pattern in which dots are formed in a predetermined area at a predetermined recording rate, and almost the same number of the first dots and the second dots have almost the same dispersibility over almost the entire area. An adjustment method, which is a test pattern formed in a mixed manner. 13. A print head having a plurality of nozzles for ejecting ink, wherein the first print head is formed at different timings by using a printing unit that forms dots on a print medium by the print head and performs printing. (A) inputting an instruction as to whether or not to execute the adjustment; and (b) executing the adjustment. When instructions are entered,
(C) printing a predetermined test pattern formed by main scanning and sub-scanning in a mode different from that in normal printing by changing the drive timing of the print head to a plurality of predetermined different timings; A) selecting an optimal test pattern from the plurality of printed test patterns; and (d) setting a drive timing of the print head corresponding to the selected test pattern. Method. 14. A recording medium in which a computer program for controlling the printing apparatus according to claim 10 is recorded in a computer-readable manner, wherein the function of the printing control apparatus according to claim 1 is provided. A computer-readable recording medium in which a computer program for causing the computer to realize is recorded. 15. A computer comprising: a print head having a plurality of nozzles for discharging ink; and a computer reading print data for controlling a printing unit that forms dots on a print medium by the print head and performs printing. A computer-readable recording medium that stores print data for printing a test pattern used in the print control device according to claim 1.