JPH0781190A - Ink-test printing method and ink jet recorder - Google Patents

Abstract

PURPOSE:To judge a test print image easily and accurately, by providing test- pattern print mode by which test patterns are formed in the same area in printing in forward scanning and backward scanning. CONSTITUTION:A test print specifying means 1 has the function of specifying one of different test-patterns in the same area to use it in test-pattern print mode; and the function of making a choice between a first test-pattern including as a test print area the central area of a recording medium and areas on the right and left sides of the central area and a second test-pattern including, as a test-pattern area, areas smaller in number than the first test-pattern. A reciprocation resist correction means 2 does not function when a fresh correction-command is not issued, but a memory means 3 for storing print-timing at which specific re-writing including reciprocation resist in reciprocating scan is caused to function.

Description

Detailed Description of the Invention

[0001]

The present invention relates to plain paper, processed paper, OH
Regarding reciprocating scanning timing correction of a contact type thermal printer, a non-contact type ink jet printer, etc., which can be applied to a printer capable of performing printing on a recording medium such as a P medium or a cloth or an output part of an information processing device, Specifically, the invention relates to an ink test printing method and a recording apparatus.

[0002]

2. Description of the Related Art With the widespread use of copying machines, word processors, information processing equipment such as computers, and communication equipment, an ink jet type recording head is used as one of image forming (recording) equipment of these equipment. Those that record digital images are rapidly spreading. In such a recording apparatus, in order to improve the recording speed, a recording head in which a plurality of recording elements are arranged in an array (hereinafter referred to as a multi-head) is formed by integrating a plurality of ink ejection ports and liquid paths. In addition, with the recent trend toward color compatibility, it is often seen that a plurality of the multi-heads are provided at the same time.

In the conventional recording method, the timing (frequency) at which ink is continuously ejected from each nozzle is determined by the pixel density of the recorded image and the carriage speed. If this timing cannot be controlled with sufficient accuracy, the recording dots on the paper surface of the recording medium will be misaligned with respect to the scanning direction of the carriage and multi-head, and will be recorded as an image with uneven density, resulting in poor image quality. Will end up. Therefore, while trying to increase the throughput as much as possible, the print dots by the head can form a good image array only when the head is driven within a range that can satisfy the limit of the frequency of the head and the given pixel density with high accuracy.

However, in the conventional test print, the operator is required to determine the optimum condition including the test print pattern itself for selecting the optimum condition. It is common to print through. This is shown in FIG.

FIG. 4 shows an example of a conventional reciprocal resist adjustment method. FIGS. 4A and 4B show forward print data (A) and forward print data (B) of forward and backward passes in the case of performing bidirectional printing of a type in which the feeding of the recording medium intervenes in both directions, respectively. Is. A recording pattern for which normal registration adjustment is performed by this data is a vertical straight line which is perpendicular to the reciprocating scanning direction in FIG. That is, a vertical straight line test pattern is formed by printing a straight line of vertical 8 dots every four horizontal dots in a reciprocating manner. Conventionally, if the print timing in both directions is deviated by 1 pixel or more due to the linearity of the vertical straight line test pattern, it can be determined whether or not the straight line of the vertical straight line test pattern is broken, and the operator can judge this, After printing is completed, the one having the best linearity is selected from the plurality of patterns, and the selected value is input to the main body by some method.

Further, conventionally, the head may move back and forth depending on the state of the head. At this time, the value is input to the main body so that the printing timing at the time of subsequent bidirectional printing is adjusted to the correction value. There is something.

[0007]

However, the linearity of the vertical straight line test pattern can be visually determined when it is deviated by 1 pixel or more, but the deviation smaller than 1 pixel is hard to be visually recognized. This is shown in FIG.
In (b), (d), and (e), the print pattern for confirming the proper correction value of the positional deviation is sequentially changed in 0.25 pixel increments for the backward pass printing centering on FIG. 4 (c). While recording multiple patterns. Conventionally, these FIG. 4 (a), (b), (d),
(E) was judged to be substantially equivalent to that in FIG. 4 (c). Therefore, the range for the purpose of visually determining and adjusting the conventional test print is only the minimum unit of 1 pixel or more.

Particularly, when bidirectional printing is performed by reciprocally scanning the recording head with respect to the recording width of the recording head when the recording medium is stopped, or when a plurality of color heads are driven in parallel. In order to maintain the optimum image quality due to changes in the usage environment of the printer, it becomes impossible to control with constant drive parameters.

A concrete explanation will be given with reference to FIGS. FIG. 9 shows a carriage 706 that scans at a speed S.
The head 901 fixed to
9A and 9B show a state in which an ink drop is ejected on a paper surface separated by a distance P, in the case of the forward path (FIG. 9-a) and the case of the backward path (FIG. 9-b). The carriage speed can be switched to S in the forward path and to -S in the reverse path, but the ejection angle of the head is always fixed in the constant direction θ. At this time, the distance between the position ejected by the head in the scanning direction and the position where ink is actually landed on the paper surface is ΔF on the forward path and ΔB on the return path, and ΔF = P × (Vsinθ + S) / Vcosθ [Delta] B = P * (Vsin [theta] -S) / Vcos [theta], and the ejection timings for the target pixel differ by a distance of ([Delta] F- [Delta] B) = P * 2S / Vcos [theta].

If this value is always constant in any recording device or recording head, the dot positions in both directions can be optimized by constantly driving the head at appropriate ejection timings. However, in reality, the thickness of the recording paper varies P, the speed variation of the carriage varies S, and the variation of the recording head varies the ejection speed V. Also,
Even with the same head, the ejection speed may change depending on the temperature and the scanning direction, or may change gradually as the ejection is repeated.

FIG. 13 shows ΔF and ΔB when the paper interval P, the carriage speed S, the ejection speed V, and the ejection angle θ in FIG. 9 are changed during forward scanning and backward scanning, respectively.
(ΔF−ΔB) and the amount of dot position deviation.

In the uppermost row of FIG. 13, the sheet interval P = 1.2 m.
m, carriage speed S = 4.318 m / sec (reciprocal same speed), ejection speed V = 12.5 / sec (reciprocal same speed), ejection angle θ = 10 ° (reciprocal same angle),
ΔF, ΔB and optimum correction amount (ΔF-
Assuming that the head is driven so that ΔB) = 84.18 μm, the bidirectional dot position deviation amount is set to “0”.

On the other hand, since the values of various factors change little by little in the second and subsequent stages, the appropriate correction amount (ΔF-ΔB) in each case is different. But,
Even at this time, since the head is driven at the same timing as the uppermost stage, a dot position deviation amount in both directions occurs,
At this time, the value of this shift amount is a difference from the uppermost stage of the optimum correction amount (ΔF−ΔB).

In the table of FIG. 13, individual factor values are normally swung, but as can be seen, the factor that can most affect the bidirectional dot misalignment is the sheet interval P. . According to this table, a gap of 42.29 μm (half a pixel or more at a pixel density of 360 dpi) occurs if the gap between sheets is changed by ± 0.2 mm with an optimized correction amount of 1.2 mm. Become. The thickness of normal paper itself is stable at about 100 μm, but such a thickness change is within a range that can be easily moved due to variations in the recording apparatus main body and variations in the recording head. It will be necessary to make corrections accordingly.

Such a change between sheets can occur not only in the variation of the recording apparatus itself but also during printing. Ideally, the printing portion on the recording paper is kept smooth by the paper holding mechanism before printing and after printing. However, when the print duty is high, or when the divided recording method is used that completes the printing by dividing the same recording scan into several recording scans, the paper surface after printing absorbs ink Shrinkage is likely to occur, and only the printing portion is likely to float. In this case, the sheet interval P may be different between the forward pass and the return pass for each printing scan, and the optimum correction amount is changed due to the floating of the paper (hereinafter referred to as cockling), which causes the dot position deviation during bidirectional printing. I will let you.

As described above, the correction amount cannot be kept constant due to various factors. Therefore, it was confirmed that it is preferable to optimize these dot positions when performing bidirectional printing or recording with a head of a plurality of colors.

[0017]

[Problems to be Solved by the Invention] In any case,
As described above, when performing bidirectional printing or recording with a head of a plurality of colors, these dot positions are determined and corrected based on the linearity of the vertical ruled line of the specific pattern. There was a limit, and there was also a limit to keeping the image good. That is, the method of confirming the dot position by the vertical ruled line described so far is difficult to make a fine adjustment for one pixel or less such as a unit of several μm.

In addition, as the image quality and the speed have been increased as in recent years, a new dot position correction method capable of performing correction in such a small amount unit is required. Further, in the past, when the material and thickness of the recording medium change for the printer, different measures are required, and it is difficult to obtain a good image state, and the recording characteristics are not affected by the material and thickness of the recording medium. It is important to be able to achieve satisfactorily and accurately, and the present invention provides a test printing method and apparatus that can meet this demand.

In any case, there is no conventional method in which the operator can easily and accurately determine the test print image.

[0020]

SUMMARY OF THE INVENTION The present invention provides a novel test printing method and apparatus by which an operator or automatic reading means can easily and accurately determine a test print image.

Further, the present invention provides a test printing method and apparatus capable of achieving good and accurate recording characteristics regardless of the material and thickness of the recording medium.

According to the present invention, not only the linearity but also the uniformity of the test print image such as the presence / absence of the image and the change of the color tone is adopted as the criterion, so that the accuracy of the determination can be remarkably improved and the accuracy of the unit of several μm can be obtained. It is an object of the present invention to provide a test printing method and apparatus that can achieve such fine adjustment of one pixel or less.

The basic feature of the present invention is that the recording medium is not conveyed during the reciprocating process and is within a predetermined width range of the recording medium in the stopped state of the recording medium (hereinafter referred to as "same region"). It is characterized by having a test pattern print mode in which a test pattern is formed in the same region by printing in the forward scanning process and the backward scanning process to which the divided data of the data forming the test pattern to be printed are respectively given. According to this, since the recording medium is not conveyed, it is possible to suppress the deterioration of the image quality of the test print due to the conveyance of the recording medium, and it is possible to more clearly determine the mutual displacement of the divided data of the data forming the test pattern. There is.

On the other hand, according to the present invention, the test pattern itself adopts the uniformity of the test print image such as the presence or absence of the image and the change of the color tone as the criterion, so that the accuracy can be more stably improved than before. is there. Specifically, a test pattern based on divided data of prints in the forward scanning process and the backward scanning process is a line pattern in the reciprocal scanning direction, preferably a line pattern in the reciprocal scanning direction with respect to the reciprocal scanning direction. The presence or absence of an image can be determined by using a pattern in which a plurality of lines are arranged with a minute gap in the vertical direction, and by using a substantially strip line pattern in the reciprocating scanning direction.

Here, the "line-shaped pattern" means that the divided data itself has a dot interval of 300 in the reciprocal scanning direction.
It means that the target normal resist print can be visually judged to be a substantial line print such that the dot interval is 300 μm or less when the actual normal resist is satisfied. Moreover, the "small gap" in the direction intersecting the reciprocating scanning direction is 1 mm.
Hereinafter, it is preferably 500 μm or less, which means that the visual determination can be made easier by the plurality of linear patterns. Further, the "line pattern" is a general visual resolution of about 150 μm when a distance of 25 cm is set on the image, so that the dot distance of the normal resist finally formed by each divided data is 150 μm. As will be seen below, it is meant that substantially normal dots form a horizontal line. In addition, the “substantially strip-shaped line pattern” has an inter-dot distance of 150 μm or less (optimally continuous dots) in the normal resist that is finally formed by the divided data in the horizontal direction, and in the vertical direction it is an actual pattern. When the normal resist is satisfied, the dot spacing is 300 μm or less (preferably 150 μm).
.mu.m or less), it includes all that can be regarded as a "solid" image having a uniform density distribution in the visual state.

In particular, in the case of the ink jet recording method, such a "uniformity pattern" will be changed in consideration of variations in ink droplets and ink bleeding on the recording medium. Is only required to be able to test-print a uniform pattern of a certain area and easily determine a dot position shift smaller than one pixel depending on the presence or absence of density unevenness or texture occurring in this pattern. More specifically, the pattern of divided data by reciprocation forming the test pattern is regularly arranged in a row in the vertical direction and in the horizontal direction at a pitch of within several pixels in each of the adjacent dots and continuously over a constant distance. It is preferable. The “pitch within several pixels” can be 400 μm or less.

According to the present invention, the line scan pattern in the reciprocal scanning direction is such that the prints of at least one of the forward scan process and the backward scan process are interposed between the prints of other processes. The fact that the printing in the forward scanning process and the printing in the backward scanning process are in order means that "registration deviation"
There is an advantage in that a test print can be provided in which the phenomenon is more clearly determined and can be more clearly determined as an increase in a region without an image or an increase in a change rate of the density distribution. Further, the length of the line-shaped pattern is preferably longer than 5 mm and more preferably 1 cm or more, but in practice, it is 2 cm.
The range of not less than 8 cm is preferable.

As a more preferable condition for the present invention, as the test pattern, two or more adjacent positions of the dots printed by the forward scan and the dots printed by the backward scan are included in the area pattern having a predetermined area. Under the conditions described above, there is a part where dots printed by the backward scan exist on the right side of the dots printed by the forward scan and a part where dots printed by the backward scan exist on the left side.
This preferable condition is that when a dot shift occurs in reciprocal scanning, both a portion where two dots are overlapped more than necessary and a portion where two dots are separated more than necessary can be present in the area pattern. Therefore, these changes in density are the units that are recognized as clarification of density unevenness and texture for visual observation or automatic density determination. In addition, it is preferable that the dots printed by the forward scan and the dots printed by the backward scan are continuous in a plurality of dots because it is easier to determine the change in density (see the embodiment).

To improve the easiness of determining density unevenness and texture is to increase the number of repetitions of the above-mentioned dot adjacent portions, which makes the thinning pattern complicated or increases the test print area in the scanning direction. It is also possible to increase the length in the direction intersecting the scanning direction to the range where all the recording dots of the recording head are used. Increasing the area occupied by this area pattern not only improves the sensitivity of density unevenness and texture, but also unevenness of scanning of the carriage and unevenness of conveyance of the recording medium (when the test pattern of the present invention is repeated), recording medium. This is preferable because it enables dot position adjustment including various unstable factors such as cockling.

In order to form the divided data of the present invention as a reliable dot image on the recording medium, particularly in the case of the ink jet, the divided data of the above-mentioned data is four or more different divided data. It is preferable that a plurality of types are provided for each of the forward scanning process and the backward scanning process to form the line pattern by a plurality of reciprocating scans. This is because the fixability of the ink droplets can be improved and the accuracy can be improved.

Forming a plurality of the test patterns in which the reciprocal scanning registration timing of the divided data is made different within a range smaller than 1.00 pixel makes it possible to perform the above-mentioned determination more easily and to easily carry out a desired resist adjustment. it can. This reciprocal scanning registration timing is 1.
Having a correction step or means capable of changing in a range smaller than 00 pixels ensures that the desired correction can be achieved. Further, the fact that the execution data of each of the forward scan and the backward scan is divided so as to be at least a plurality of dots continuous in the scanning direction further clarifies the feature of the present invention.

According to the present invention, the test pattern print mode has a plurality of different same area test patterns, and the test pattern in the test pattern print mode is specified by specifying each of the plurality of same area test patterns. By making it possible to perform adjustment according to the accuracy requirement of the apparatus, for example, high accuracy determination can be made at the time of shipment of the apparatus, and then a normal level determination can be made for subsequent operator's determination. .
The high-accuracy determination may include a first test pattern including a central area of the recording medium and left and right areas of the central area as test print areas. The second test pattern may include a region smaller than the test pattern as a test print region. In this example of high precision determination, the entire state of the recording medium in the width direction can be taken into consideration.
This is a preferred example.

The color test print of the present invention is also possible with the above invention, but is characterized by adopting a more developed change in image color as a criterion, and specifically,
In an ink test printing method capable of executing a bidirectional mode in which printing is performed by reciprocal scanning of a multi-color multi-dot head for the same area, the data forming the overlapping test pattern of the multiple colors to be printed for the same area is divided by color. The ink test printing method is characterized in that it has a test pattern print mode for forming an overlapping test pattern of a plurality of colors in the same region by printing the forward scanning process and the backward scanning process to which data is respectively given.

The apparatus invention of the present invention includes a carriage for carrying out reciprocal scanning with a multi-inkjet head mounted thereon, a transport means for transporting a recording medium in a direction intersecting the scanning direction, and a multi-dot head for the same area. In an inkjet recording apparatus provided with a bidirectional mode in which printing is performed by both reciprocating scanning and a memory means for storing a test pattern for displaying a reciprocating resist, the memory means stops the recording medium as the test pattern. A typical example is an inkjet recording apparatus characterized in that it stores forward scan process data and backward scan process data, which are divided data of data forming a test pattern to be printed in the same area in a state. .

According to the ink jet recording apparatus of the present invention,
Using a multi-head with multiple ink ejection ports arranged,
In an inkjet recording method that completes recording by performing bidirectional recording scanning and relatively sequential paper feed, the same printing area is divided into forward scanning and backward scanning divided recording (or multi-color multi-head) Such a pattern is completed, and the proper value of the bidirectional recording timing (or the proper value of the recording timing of each color multi-head) is determined and stored based on the goodness of the uniformity of the pattern (or the difference in tint). As a result, it has become possible to perform dot position correction with higher accuracy than ever before and obtain high-quality images.

The invention will be understood more clearly by the following description of the examples.

[0037]

FIG. 7 shows a typical outline of the constitution of the apparatus of the present invention, and shows the constitution of a color printer section when printing on the paper surface by the multi-head. In this figure, reference numeral 701 is an ink cartridge. These are ink tanks filled with four color inks, black, cyan, magenta, and yellow, respectively,
702 multi-head. FIG. 8 shows a state of the multi-nozzles arranged on the multi-head from the z direction, and 81 is a multi-nozzle arranged on the multi-head 702. In this figure, the multi-nozzle 8
01 are arranged in parallel along the Y-axis, but they may have some inclination on the XY plane in the figure, for example. In this case, while the head moves in the traveling direction X, each nozzle performs printing while shifting the timing. Return to FIG. 7 again. A paper feed roller 703 rotates in the direction of the arrow in the figure while holding the print paper 707 together with the auxiliary roller of 704, and feeds the print paper 707 in the y direction at any time. Further, reference numeral 705 denotes a paper feed roller which feeds the printing paper and also plays a role of suppressing the printing paper 707 similarly to 703 and 704. Reference numeral 706 is a carriage that supports four ink cartridges and moves them with printing. This is when not printing
Alternatively, when performing a multi-head recovery operation or the like, the home position (h) at the position shown by the dotted line in the figure is waited.

Before the start of printing, the carriage (706) at the position shown in the figure (home position) moves in the x direction when the print start command arrives, and the multi-head (702) moves.
The upper n multi-nozzles (81) provide a width D on the paper.
Just print. When the data printing is completed up to the edge of the paper, the carriage returns to the original home position and x
Print in the direction. In this apparatus, in the reciprocal printing mode, the next printing is performed at the stage of moving in the -x direction with the recording medium stopped, thereby completing the printing of the width D.

From the end of the first printing (printing of the width D) to the start of the second printing, the paper feed roller (703) rotates in the arrow direction to move in the y direction corresponding to the width D. Paper feed. Carriage 1 in this way
By repeating the printing of the multi-head width D and the paper feeding for each scan, the data printing on one paper surface is completed.

The first embodiment will be described below with reference to FIG. FIG. 1 shows that a complete strip-shaped area pattern is formed as a test pattern (substantially strip-shaped line pattern area patterning is also viewed substantially equivalently). , ± 0.
A pattern in which the ejection drive timing is shifted by 1/4 pixel for bidirectional printing centered on 00 pixel (± 0.25 pixel
el, ± 0.50 pixel).

In the present embodiment, a block of the number of nozzles of the vertical head × 4 pixels in the horizontal direction is printed 50% at a time so as to have a complementary relationship between the forward print scan and the backward print scan to form a 100% solid image. . In this embodiment, a multi-head having 16-pixel nozzles in the vertical direction is assumed, and therefore a pattern of 16-pixels in the vertical direction is shown in FIG. The effect of this embodiment can be obtained by partially using continuous nozzles without using nozzles.

In the conventional example, the proper value is judged from the linearity of the vertical ruled line, but in this embodiment, it is judged from the uniformity of the entire image. As can be seen from FIG. 1, when the dot correction is not sufficient, the forward printing and the backward printing are not complemented sufficiently, and a gap appears between the blocks as a thin white line. When actually observed, this has a fine texture in the vertical direction, resulting in an image with impaired uniformity.

The process in which the user actually performs the reciprocating register adjustment will be described below with reference to FIG.

First, the user designates the bidirectional registration adjustment mode by the SW of the main body, whereby the main body enters the user registration adjustment mode. Then, the user is notified that the mode has been entered by using an LED or the like.

The user confirms that the adjustment mode has been entered and starts registration pattern printing. FIG. 5 shows an arrangement example of the patterns recorded by this. This figure shows a pattern recorded in 15 steps in the paper feed direction while changing the reciprocating dot position by 10 μm, and the user selects the pattern with the most uniformness from this pattern group. Since the pattern is printed at three points on the paper surface for each step, it is possible to judge the slight unevenness of the carriage speed and the floating of the paper, which occur on the left and right sides of the paper surface, in consideration of the whole.

Four LEDs are provided between the left end and the center pattern
A model diagram showing the lighting state of is simultaneously printed, which is used when the registration adjustment pattern selected by the user is input to the main body. The user adjusts the LED of the main body to the lighting state of the LED shown next to the most uniform pattern by the input SW. For example, in FIG. 5, if it is determined that the pattern beside XX is the most uniform, the input SW is pressed several times until the LED changes to XX, and Press the SW for storage in the state. As a result, the main body stores the ejection timing in both directions when a uniform 100% image is obtained, and in the subsequent printing, the head is always ejected at the above timing.

After the new correction value has been stored in the ROM or the like, the user register adjustment mode ends and the main body returns to the normal print mode again.

In FIG. 5, the ink ejection timing in both directions is changed in 15 steps every 10 μm, but the pitch and the number of steps are twice or more the distance of each pixel of the print image on the same paper surface. It is desirable to do so. In this embodiment, 360 dpi, that is, 70 between pixels
Since it is assumed that the condition is around μm, it is 2 before and after the center value.
It is possible to obtain the shifted state of the dots over the pixels of 140 μm.

Further, here, -70 μm to +70 μm
Until then, all patterns are always printed at equal intervals of 10 μm. However, by increasing the shift amount at both ends as described below, it is possible to form a state in which uniformity is obviously deteriorated on both sides of all patterns. Is also good.

In FIG. 5, both sides 3 from the center ○○ ●●
The pattern is shifted ± 20 μm. After that, the two patterns are shifted ± 30 μm, and the last two patterns are ± 40 μm.
Let's move it one by one. Then, this correction pattern is all 15
Even though it is a pattern, it is possible to control a range of ± 200 μm with respect to the center value. If you do this, all 15
Dot dots in both directions are completely displaced in the pattern, and a state in which uniformity is clearly deteriorated will always occur on both sides, so even if it is difficult to determine the uniformity near the appropriate value, the white stripe The proper value can be easily determined by the distance (the number of steps) from the patterns on both sides, where can be clearly confirmed.

In the present embodiment, the print pattern has been described in units of horizontal 4 blocks, but the shape and size of this block are not limited to this. Further, if a block that is long in the lateral direction is used, the period in which white stripes appear becomes longer, and rough texture can be seen. Also, if the print patterns of the forward pass and the backward pass are reversed every several pixels in the vertical direction, short white stripes will appear finely in places. In any case, it is advisable to apply a block unit that creates a texture that clearly shows the difference between good and bad uniformity.

As described above, according to this embodiment,
The appropriate printing timing is determined from the uniformity of the pattern that prints in block units so that the forward printing scan and the backward printing scan have a complementary relationship, and by inputting to the main body, the landing position during bidirectional printing It is possible to correct the deviation with high accuracy.

The second embodiment will be described below. FIG. 2 shows an embodiment in which a substantially strip-shaped line pattern is formed as a test pattern, and a plurality of reciprocating scans are provided by providing a plurality of different types of divided data for each of the forward scan process and the backward scan process. Is also an example of forming the above line pattern. Similar to FIG. 1, this example also shows the effect of this example by comparing with FIG. Here, when one pattern is printed, recording scanning is performed four times and paper feed scanning is performed for each head adjustment 1/4 (4 pixels) in the same image area to perform divided recording.

The pattern printed from the first recording scan to the fourth recording scan is shown in the upper part of FIG. The pattern finally formed in this embodiment is a set of horizontal ruled lines arranged in the vertical direction at intervals of every other pixel, and becomes a 50% duty image as shown in the figure. Similar to the first embodiment, the pattern configuration is such that the uniformity is judged from the white stripes in the vertical direction.

In this embodiment, the first print scan and the third print scan are forward prints, and the second print scan and the fourth print scan are backward prints. In this way, when one image is formed by two print scans, a slight dot positional deviation that occurs in each print scan is reduced to 1/2. In addition, 1 /
Since the divided recording is performed while feeding the paper for each four head widths, the horizontal ruled lines extending in the main scanning direction are recorded by four types of nozzles, and the deviation peculiar to the nozzles and the variation in the ejection amount are alleviated. Therefore, in this embodiment, various irregularities caused by the above factors are made inconspicuous in advance, and only the dot deviation between the forward printing and the backward printing appears clearly as the texture, while the dot deviation does not occur. Since the characteristics are further enhanced, it becomes easy to select a good pattern arrangement from the pattern arrangement as shown in FIG.

Further, as a variation of the print pattern for each recording scan of the present embodiment, two examples (a) of FIG.
(B) is shown. According to (a), the texture due to the bidirectional printing dot shift is the same as that in FIG. 2, but the first printing scan and the third printing scan, and the second printing scan and the fourth printing scan are staggered ink by pixel for each pixel. Since the nozzles are landed, it is possible to make the nozzle-specific deviation and the variation in the discharge amount, which are described above, more inconspicuous. Further, (b) is a reverse of the second recording scan and the third recording scan of the printing method of FIG. 2, and when this is done, white lines due to bidirectional dot shift appear every four pixels in the horizontal direction. It is possible to make the texture stand out when it is further deviated. Also in these embodiments, the process when the user performs the reciprocating registration adjustment is as shown in FIG. 6, and after the adjustment is completed, the subsequent ejection timing is controlled by the input data.

As described above, according to this embodiment, 2
The appropriate value of the ejection timing is determined from the uniformity by forming a plurality of patterns in which the ejection timing is changed stepwise while performing the division printing by the forward printing scan of two times and the backward printing scan of two times. By inputting into the main body, it is possible to highly accurately correct the landing position deviation during bidirectional printing.

In the first and second embodiments, the dot misregistration correction for bidirectional printing with a single color (one head) has been described, but both embodiments are of course effective for color inks. In this case, each color pattern may be printed as a reference value at the same time in the pattern of FIG.
Alternatively, the correction value may be input independently for each color. However, in the latter case, dot misalignment between colors must be guaranteed at the same time.

As a third embodiment, a method of correcting dot misalignment of each color in the four-color ink jet recording apparatus having the structure shown in FIG. 7 will be described below. First, magenta and black will be described as an example.

FIG. 3 shows an image state when the printing pattern of four recording scans used in this embodiment and the ejection timing of magenta are shifted by 1/4 pixel unit with respect to black. . In this embodiment as well, as in the second embodiment, it is assumed that the pattern is formed by four divided recording scans. Therefore, also in the present embodiment, the factors of dot deviation and ejection amount variation due to nozzle variation can be eliminated in advance.

The present embodiment differs from the previous embodiments in that the textures shown in FIGS. 1 and 2 do not appear. In the case of this embodiment, it appears as a difference in color. Normally, when a black dot and a magenta dot overlap and land on the same pixel, magenta is erased to have a black tint, and almost no color is produced. Pixels in this state are shown in gray in FIG. But,
When the magenta dots are gradually displaced from the black dots, the magenta tint becomes stronger only in the misaligned area, and the overall image becomes reddish depending on the amount of deviation. Go. In FIG. 3, this protruding portion is shown in black.

When the pattern is traced from the region shifted in the minus direction to the region shifted in the plus direction, the red meat of the entire pattern gradually decreases, and the pattern with the strongest black tint is returned to Sakai again. It becomes reddish.

The user selects this portion with the least red meat and inputs it to the main body as in the previous embodiments.

The correction method for magenta and black has been described above. However, as described above, such correction is
Must be done for all colors, all heads. Therefore, in this embodiment, three patterns of black and cyan, black and magenta, and black and yellow are output,
The data for each of the three colors, cyan, magenta, and yellow, is input to the main body in a form that matches the data for black.

Further, in the ink jet used in this embodiment, the color head also performs bidirectional printing, and the user performs both dot misregistration correction between each color and dot misregistration correction during bidirectional printing for each color in the following procedure. To do. FIG. 12 shows a flowchart of these correction steps.

When the user specifies the cash register adjustment mode,
The main unit first enters the dot misalignment correction mode for each color.

When the user confirms that the correction mode is entered by turning on the LED or the like and presses the start SW, the main body starts printing the dot misalignment correction pattern of each color using the four-color head. The sample output at this time is the pattern shown in FIG. 3 arranged as shown in FIG. 5, but the pattern is printed for three combinations of black and cyan, black and magenta, and black and yellow. To do. Also in this case, the ejection timing is changed in 15 steps every 10 μm.
Similar to FIG. 5, the LED model corresponding to each is also printed at the same time.

From the output sample, the user selects a pattern closest to black for each of the three colors, first sets the LED state at the selected position for cyan, and stores the ejection timing in the cyan forward direction in the memory SW.

Similarly, input and storage operations for magenta and yellow are performed.

When the storage of the yellow dot position correction is completed, the main body enters the bidirectional dot position correction mode.
The user confirmed that the sample could be printed again,
Press the start SW. As a result, printing of the bidirectional dot position correction pattern is started using the 4-color head.
The pattern printed here is the one shown in FIG.
The ejection timing is also changed in 15 steps every 10 μm, and the LED model corresponding to each is also printed at the same time.

The user selects a pattern having the best uniformity for each color and inputs a correction value using LEDs in the order of black, cyan, magenta, and yellow.

When the storage of the last yellow correction value is completed, all the dot position correction modes are completed and the main body returns to the normal print mode.

In the present embodiment, first, in one-sided printing, each color is adjusted to the ejection timing of the black head, and thereafter, the ejection timing in the backward direction is adjusted to the ejection timing in the outward direction for each color. Therefore, it is necessary to previously have a configuration in which the forward printing and the backward printing of each color can be independently corrected.

However, even if it does not have such a configuration,
After correcting each color according to black, by correcting the dot position in both directions for black only, if each color has the same correction as black, dot misalignment in color bidirectional printing can be sufficiently corrected. Will.

As described above, according to the present embodiment, when the pattern shown in FIG. 3 is divided and printed by four unidirectional scans, a plurality of patterns in which the ejection timing is changed stepwise are used. By forming the above, the appropriate value of the ejection timing of each color head is judged from the uniformity, and by inputting into the main body, it is possible to highly accurately correct the landing position deviation during bidirectional printing.

Although the above description has been made on the basis of the case where the user himself / herself performs the correction, if these corrections are performed at the time of shipment of the main body and the correction value here is set as the center value of the user registration adjustment pattern, the adjustment range thereafter is set. You can narrow it down beforehand. The factors that actually cause these dot shifts are
As described above, since many of them are specific to the recording apparatus main body, it is preferable to make such an absolute correction before loading.

FIG. 10 shows a block diagram of an example of a printing apparatus of the present invention. Reference numeral 1 is a means for designating a test print mode, which functions as an operating mechanism for executing the test print mode in the normal recording mode. In this embodiment, the function of designating a test pattern in the test pattern print mode by designating one of a plurality of different same-area test patterns and the central area of the recording medium It has both a function of being able to select a first test pattern including the left and right regions of the central region as a test print region and a second test pattern including a region smaller than the first test pattern as a test print region. ing. Reference numeral 2 denotes a reciprocal registration correcting unit in the reciprocating scan of the print, which does not function when there is no new correction command, and causes the memory unit 3 which stores a predetermined rewritable print timing including the reciprocating resist in the reciprocating scanning to function. The memory means 3 also uses the stored reciprocating resist in the reciprocating scan as the reciprocating resist in the reciprocal recording scan in the normal recording mode. 8 is a recording medium 1 for correcting the reciprocating resist.
0 is a means for discriminating the state of the test pattern (described later, automatic discrimination means, etc.) or a printing discrimination means as a means operated by the operator, which operates the reciprocal registration correcting means 2 and inputs it to the printing discrimination means 8. Then, the reciprocating resist of the memory means 3 is rewritten.

On the other hand, reference numeral 5 is a data memory means for storing the test print data and area data for determining the print area, and has forward scan data 51, backward scan data 52 and other data and area data storage means 6. In the present embodiment, it becomes possible to make adjustments according to the accuracy requirements of the device, and for example, high accuracy determination is performed at the time of shipping of the device, and then a normal level determination can be performed for the operator's determination thereafter. Includes a central area of the recording medium and the left and right areas of the central area as test print areas.
A test pattern can be cited. As a normal level judgment, a second test pattern including an area smaller than the first test pattern as a test print area is used. Further, although only one data may be stored in the data memory means 5, in the present embodiment, the stored data X (= forward scan data X1 + reverse scan data X2), Y, Z.
Are divided into reciprocating scans respectively as shown by the mathematical formulas in the figure (all the contents described in the above-mentioned embodiments and the outline of the invention are applicable), and the forward scan data of these divided data is " 1 "and" 2 "are added to the backward scanning data. Particularly, in this embodiment, since the ink jet recording method is adopted, it is preferable that the stored data Z is used normally or fixedly. Stored data Z is different for each 4
A plurality of types of divided data (A1, B1, A2, B2) of more than one type are given to each of the forward scan process (A1, B1) and the backward scan process (A2, B2), and a plurality of reciprocating scans are performed. As described above, the test pattern can be printed.

Reference numeral 4 is a known carriage reciprocating means, which is provided with a position detecting mechanism such as a motor and an encoder as the reciprocating drive switching means 41. Reference numeral 7 is a known head driving means, and in this embodiment, Canon Co., Ltd. using film boiling is used.
The ink jet head driving means of the bubble jet system proposed by the present invention is provided with a means 71 for performing reciprocal printing switching at a timing according to the reciprocating resist. Further, in the test print mode, the head driving means 7 has a large number of heating elements for forming bubbles in the test pattern in which the reciprocal scanning resist timing of the divided data is varied within a range smaller than 1.00 pixel as shown in FIG. A plurality of multi-nozzle inkjet heads 9 are used to form a plurality.

With the apparatus configuration of FIG. 10, the above-described embodiments can be executed, and the invention described in the outline of the present invention can be executed. In particular, when the ink jet head has a head structure in which the positions of the plurality of color heads have already been mutually adjusted in advance and integrated as shown in FIGS. 7 and 14, the registration adjustment of each head unit is performed for one of the head units. It can be determined by an ink test, and it will be understood that the block diagram in this embodiment can be used for either a single color or a multi-color integrated head.

Next, a fourth embodiment will be described. In the present embodiment, it is assumed that the pattern after printing is read by the reading device attached to the main body, and the determination of uniformity and the input of an appropriate value are all performed automatically.

FIG. 14 is a perspective view of the main body of the ink jet recording apparatus used in this embodiment. A CCD camera as a reading device is attached to the side of the carriage shown in FIG. FIG. 15-a shows the reading section of the CCD camera as seen from the paper side, and the CCDs are arranged in a line in the nozzle arrangement direction with a pixel density equal to the nozzle pitch.

When the printing apparatus completes printing of one pattern in the same manner as in the above-described embodiment, the carriage makes another scan, and the density distribution in the scanning direction is read from the CCD at this time.

FIG. 16 shows each pattern and its density distribution data when the same pattern as that of FIG. 5 is used. By scanning the plurality of patterns shown on the left side of the drawing by the carriage once, the density distribution in each pattern scanning direction is obtained as shown in the right figure. Here, the horizontal axis is the address in the scanning direction,
The vertical axis represents the concentration. As can be seen from the figure, the density density is large where the dot deviation is large during bidirectional printing, and the amplitude is almost 0 when the dot deviation does not occur.

In this embodiment, a plurality of CCD cameras are used,
Since the average value of each read data is used as the density distribution, the characteristic variation of each CCD camera and the characteristic variation during scanning are also corrected. Therefore, it is possible to determine the uniformity of the density distribution with a high resolution, and it is possible to more accurately determine an appropriate value from a plurality of patterns. After that, the main body automatically stores the determined appropriate value, and the value is used for the subsequent recording.

As described above, in the present embodiment, the main body automatically performs reading, discrimination, and storage, so that the user only needs to specify the adjustment mode once and does not need any other complicated operation. Further, since the high resolution CCD camera is used, the correction itself is accurate.

Further, although the correction of the bidirectional dot shift has been described above, in the present embodiment, the dot shift correction of each color multi-head shown in the third embodiment can also be performed. In this case, since the difference between the patterns does not appear due to the difference in amplitude but to the difference in tint, the CCD camera needs to detect the difference in tint for each pattern.

In FIG. 16-b, a CCD with each color filter of red (R), green (G) and yellow (Y)
The cameras are arranged alternately. Here again, reading scanning is performed for each pattern, and each CCD camera reads each density distribution. In this case, since the density distribution is not necessary, the average value in the scanning direction is calculated, and the average value between the same color filters is calculated and used as each color density. That is, the average value of the red filter is cyan density, the green filter is magenta density, and the blue filter is yellow density.

To explain with reference to FIG. 3 used in the third embodiment, if the pattern having the weakest magenta density and the strongest black density is discriminated from the read data of each pattern, it is determined that the pattern is magenta or black head. It becomes an appropriate value.

According to the present embodiment as described above,
The plurality of patterns used in the above-described embodiment are read by the reading device of the main body, the proper value of the ejection timing of the bidirectional or each color head is judged from the uniformity, and the landing position shift is automatically input and stored in the main body. It is possible to correct with high accuracy.

Although the examples of the present invention are listed by limiting the examples to help understanding of the present invention, the present invention can be any combination of the above-mentioned outline of the invention and the examples. The invention can be applied to the case where a printer is used.

According to the present invention, even when a multi-head in which a plurality of ink ejection openings are arranged is used, the ink jet recording is completed by performing the bidirectional printing scan and relatively sequentially feeding the paper. In the recording method, a uniform pattern is completed by dividing the forward scan and the backward scan in the same printing area (or multi-heads of a plurality of colors), and the goodness of the uniformity of the pattern (or the difference in tint) is obtained. ), The proper value of the bidirectional recording timing (or the proper value of the recording timing of each color multi-head) is determined and stored, so that the dot position correction can be performed with higher accuracy than before and a high quality image can be obtained. It became so.

[0093]

As described above, according to the present invention, it is possible to exceed the judgment limit of the judgment based on the linearity of the vertical ruled line as in the prior art, to keep the image in good condition, and to reduce the number of pixels of 1 pixel or less such as a unit of several μm. It was possible to fine-tune the. Further, by using the present invention, a good image state can be easily achieved with good recording characteristics and high accuracy even if the material and thickness of the recording medium are changed. Particularly, when performing bidirectional printing or recording with a head of a plurality of colors, the level of optimizing these dot positions can be significantly improved, and high-speed recording of color prints and high image quality can be achieved.

[Brief description of drawings]

FIG. 1 is a diagram showing a correction pattern according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a correction pattern according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a correction pattern according to a third embodiment of the present invention.

FIG. 4 is a diagram showing an example of a bidirectional dot correction pattern of a conventional example.

FIG. 5 is a diagram showing a correction sample of the present invention.

FIG. 6 is a correction process flowchart of the first and second embodiments.

FIG. 7 is a diagram of a printing unit of the inkjet printer used in the present invention.

FIG. 8 is a diagram of a multi-head used in the present invention.

FIG. 9 is an explanatory diagram of dot misalignment during bidirectional printing by an inkjet printer.

FIG. 10 is a block diagram showing an outline of the present invention.

FIG. 11 is a diagram showing a variation of pattern printing according to the second embodiment of the present invention.

FIG. 12 is a correction process flowchart of the third embodiment.

FIG. 13 is a diagram showing a list showing a relationship between a dot shift factor and a dot shift amount.

FIG. 14 is a diagram showing a printing unit and a reading unit of a recording device used in a fourth embodiment of the present invention.

FIG. 15 is an enlarged view of a reading unit used in the fourth embodiment of the present invention.

FIG. 16 is a concentration distribution data diagram of the fourth embodiment of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigeyasu Nagoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (31)

[Claims] 1. In an ink test printing method capable of executing a bidirectional mode in which printing is performed by reciprocating scanning of a multi-dot head with respect to the same area, divided data of data constituting a test pattern to be printed in the same area are respectively provided. An ink test printing method characterized by having a test pattern print mode in which a test pattern is formed in the same region by printing in a given forward scanning process and backward scanning process. 2. The ink test printing method according to claim 1, wherein the test pattern is a line pattern in the reciprocating scanning direction. 3. The ink test print according to claim 2, wherein the test pattern is a pattern in which a plurality of line-shaped patterns in the reciprocating scanning direction are arranged with a minute gap in a direction perpendicular to the reciprocating scanning direction. Method. 4. The ink test printing method according to claim 1, wherein the test pattern is a substantially band-shaped line pattern in the reciprocating scanning direction. 5. The test pattern is a line pattern in the reciprocal scanning direction in which prints of at least one of the forward scan process and the backward scan process are interposed between prints of other processes. 5. The ink test print method according to claim 4. 6. The divided data of the data is different from each other.
6. A plurality of types of divided data are given to each of the forward scan process and the backward scan process to form the line pattern by a plurality of reciprocating scans.
Either ink test print method. 7. The ink test print method according to claim 1, wherein the multi-dot head is an ink jet head provided with a plurality of ink ejection ports in a direction intersecting with the reciprocal scanning direction. 8. The multi-dot head has a plurality of head parts integrated with each other in advance by adjusting their mutual positional intervals, and each head part has a plurality of ink ejection ports in a direction intersecting the reciprocating scanning direction. The ink test printing method according to any one of claims 1 to 7, characterized in that, with the provided inkjet head, the registration adjustment of each head portion is determined by an ink test of one of the head portions. 9. The ink test printing method according to claim 1, wherein a plurality of the test patterns are formed with different reciprocal scanning resist timings of the divided data within a range smaller than 1.00 pixel. . 10. The ink test print method according to claim 9, further comprising a correction step capable of changing the reciprocal scanning resist timing within a range smaller than 1.00 pixel. 11. The divided data is divided so that the data executed in each of the forward scanning and the backward scanning is at least a plurality of dots continuous in the scanning direction. Item 10 Any one of the ink test print methods. 12. The test pattern print mode has a plurality of different same area test patterns,
The ink test print method according to any one of claims 1 to 11, wherein a test pattern in a test pattern print mode can be specified by specifying each of the plurality of same area test patterns. 13. A plurality of the same area test patterns, a first test pattern including a central area of a recording medium and left and right areas of the central area as a test print area, and more than the first test pattern. The second test pattern including a small area as a test print area, and the ink test print method according to claim 12. 14. In an ink test printing method capable of executing a bidirectional mode in which printing is performed by reciprocating scanning of a multi-color multi-dot head on the same area, an overlay test pattern of a plurality of colors to be printed on the same area is configured. An ink test printing method characterized by having a test pattern print mode for forming an overlapping test pattern of a plurality of colors in the same region by printing in a forward scanning process and a backward scanning process, each of which is provided with divided data for each color. . 15. A carriage that carries a reciprocating scan by mounting a multi-inkjet head, a conveying means for conveying a recording medium in a direction intersecting the scanning direction, and a reciprocating scan of a multi-dot head for the same area for printing. In an ink jet recording apparatus provided with a bidirectional mode for carrying out the above, and a memory means for storing a test pattern for displaying a reciprocating resist, the memory means is the test pattern for the same area in the stopped state of the recording medium. An ink jet recording apparatus characterized in that it stores data for a forward scanning process and data for a backward scanning process which are divided data of data forming a test pattern to be printed. 16. The ink jet recording apparatus according to claim 15, wherein the test pattern is a line pattern in the reciprocating scanning direction. 17. The ink jet recording apparatus according to claim 16, wherein the test pattern is a pattern in which a plurality of line-shaped patterns in the reciprocal scanning direction are arranged with a minute gap in a direction perpendicular to the reciprocal scanning direction. . 18. The ink jet recording apparatus according to claim 15, wherein the test pattern is a substantially strip line pattern in the reciprocating scanning direction. 19. The reciprocal scanning direction line pattern, wherein the test pattern is a line pattern in a reciprocal scanning direction in which prints of at least one of the forward scan process and the backward scan process are interposed between prints of other processes. The inkjet recording device according to claim 18. 20. A plurality of types of divided data of the data are given to each of the forward scanning process and the backward scanning process as four or more different types of divided data, and the line pattern is formed by a plurality of reciprocating scans. The inkjet recording device according to any one of claims 15 to 19. 21. The multi-inkjet head comprises:
An ink jet head having a plurality of ink jet head portions whose mutual positional intervals are adjusted in advance and each of which is provided with a plurality of ink ejection ports in a direction intersecting the reciprocating scanning direction. 21. The ink jet recording apparatus according to claim 15, further comprising means for determining the registration adjustment by an ink test of one head portion of the registration adjustment. 22. The apparatus according to claim 15, further comprising means for forming a plurality of the test patterns in which the reciprocal scanning registration timing of the divided data is varied within a range smaller than 1.00 pixel. Two
One of the inkjet recording devices. 23. The ink jet recording apparatus according to claim 22, wherein the apparatus has a correction unit capable of changing the reciprocal scanning registration timing within a range smaller than 1.00 pixel. 24. The divided data is divided so that the data executed in each of the forward scanning and the backward scanning is at least a plurality of dots continuous in the scanning direction on the one hand. The ink jet recording apparatus according to claim 23. 25. The memory means comprises a plurality of different same area test patterns, and a designating means for executing a test pattern print using any one of the plurality of same area test patterns. 25. The ink jet recording apparatus according to any one of claims 15 to 24. 26. The plurality of same-area test patterns include a first test pattern including a central area of a recording medium and left and right areas of the central area as test print areas, and a first test pattern more than the first test pattern. 26. The inkjet recording apparatus according to claim 25, further comprising a second test pattern including a small area as a test print area. 27. The apparatus according to claim 15, further comprising means for automatically reading a print state of the same area test pattern and automatically performing registration adjustment. Inkjet recording device. 28. In an ink test printing method capable of executing a bidirectional mode in which printing is performed by both reciprocal scanning of a multi-dot head for the same area, divided data of data forming a test pattern to be printed for the same area are each divided. An ink test printing method comprising: a test pattern print mode for forming a same-area test pattern in which a given forward scanning process and a backward scanning process are printed with a predetermined resist together with an instruction mark for giving the resist. 29. The test pattern is a substantially strip-shaped line pattern in the reciprocal scanning direction in which the prints of the forward scan process and the backward scan process are interposed between the prints of at least one process. In the test pattern print mode, at least the reciprocal scan resist timing of the divided data is centered on the print of the forward scan process and the backward scan process with the designated resist in both directions of ± within a range smaller than 1.00 pixel. 3. A plurality of different test patterns are formed.
8. Ink test print method. 30. An apparatus capable of executing the ink test printing method according to claim 28, wherein a resist corresponding to the instruction mark in the forward scanning step and the backward scanning step is recorded on the apparatus by an operation corresponding to the instruction mark. A printing apparatus comprising means for changing to a resist for printing and / or a resist designated in the test pattern print mode. 31. A first test pattern including a central area of the recording medium for the test pattern print mode and left and right areas of the central area as test print areas, and an area smaller than the first test pattern. A second test pattern including as a test print area, and means for designating a test pattern in a test pattern print mode by designating each of the plurality of same area test patterns. Printing equipment.