JP2001180018A - Ink jet recording method and ink jet recorder for recording through reciprocal scanning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance recording speed while reducing conspicuous recording irregularity due to reciprocal scanning. SOLUTION: Among image data corresponding to scanning regions for recording, the recording duty is calculated for a plurality of different regions under scanning, a scanning direction is determined depending on the recording duties of the plurality of regions and then recording is performed according to the determined scanning direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording method for forming an image by discharging a recording liquid such as ink onto a recording medium while scanning a recording means.

[0002] In particular, the present invention relates to an ink jet recording method for preventing deterioration of image quality by reciprocal scanning.

[0003]

2. Description of the Related Art Conventionally, an ink jet recording method for recording on various types of recording media is capable of high-density and high-speed recording operations. It has been applied and commercialized.

[0004] In this case, each recording device has a configuration corresponding to a function, a usage form, and the like unique to these devices.

In general, an ink jet recording apparatus includes a carriage on which recording means (recording head) and an ink tank are mounted, a conveying means for conveying a recording medium, and a control means for controlling these. Then, the recording head for ejecting ink droplets from the plurality of ejection ports is serially scanned in a direction (main scanning direction) intersecting with, for example, a direction perpendicular to the transport direction (sub-scanning direction) of the recording medium. The recording medium is intermittently conveyed by an amount equal to the recording width.

In this recording method, recording is performed by discharging ink onto recording paper in accordance with a recording signal, and is widely used as a quiet recording method with a low running cost. In recent years, many products using inks of a plurality of colors and applied to a color recording apparatus have been put into practical use.

When the ink jet recording method is applied to a color recording apparatus, the constitution of the recording head is roughly classified into two types.

First, as shown in FIG. 14, there is a recording head in which a number of nozzles for ejecting ink are arranged linearly in the sub-scanning direction. FIG. 14A shows nozzles 100y, 100m, 100c, and 100k for discharging yellow, magenta, cyan, and black inks arranged in one row in the sub-scanning direction so that the colors do not overlap. FIG. 14B shows a nozzle 101k that discharges black ink and a nozzle 101 that discharges color ink.
y, 101m, and 101c.
As apparent from FIG. 14, with respect to yellow, magenta, and cyan, one main scan of the recording head forms images of each color at different positions on the recording medium, so that the so-called blue, red, and green colors are used. When forming a secondary color, the order of superimposition of colors is constant regardless of the scanning direction of the recording head. For example, when forming a blue image,
First, after cyan is recorded, magenta is superimposed and recorded thereon. Therefore, when the print head 100 or the print head 101 is used, color unevenness does not occur even when printing is performed in the forward scan and the backward scan of the print head.

However, if the number of nozzles of each color is increased to increase the speed, the length of the recording head becomes longer and the size of the recording head tends to increase, or the method of suppressing the recording medium in the recording section tends to become more complicated. This leads to an increase in the cost of the recording head and the apparatus.

[0010] Second, as shown in FIG. 15, for example, recording heads 102k, 102c, and 102 ejecting black ink, cyan ink, magenta ink, and yellow ink.
m and 102y are arranged in the main scanning direction.
When the print head 102 is used, inks of all colors are ejected in one scan according to image data.

Here, in order to increase the speed, the forward scan (arrow A in the figure)
Direction) and the backward scanning (the direction of arrow B in the figure) are alternately repeated to form an image. For example, in the case of forming a so-called secondary color of blue, red, and green, the order of color superposition is determined by the recording head 102. In the forward scan (direction of arrow A in the figure) and in the backward scan (direction of arrow B in the figure). As a result,
The color (hue) differs in each scan, resulting in color unevenness, which greatly reduces image quality.

As described above, there are two types of configurations of the ink jet recording head applied to the color recording apparatus. However, it is suitable for increasing the speed of the apparatus that the nozzles of each color are arranged in the scanning direction of the recording head. It can be said that it is a type (the latter). However, as described above, there is a problem that color unevenness occurs in each scan due to a difference in the color overlapping order between the forward scan and the backward scan of the print head.

In order to solve this problem, Japanese Patent Publication No. 3-54
No. 508 discloses a method of making the color processing method different between the forward scan and the backward scan of the print head. However,
This method requires two types of color processing tables, forward scan and backward scan.

When recording is performed by an ordinary printer, color processing is performed by a printer driver on a host computer, and the image data after the color processing is sent to the printer main body. Recording is performed by processing and processing according to the recording head, but when performing color processing with the printer driver, the color of the image data being processed is determined in advance by knowing how it will be recorded on the main unit side. Processing needs to be performed. That is, the host computer must know whether recording is performed in the forward scan or the backward scan of the recording head, but this greatly complicates the system including the printer driver and the printer body.

Further, since the color gamut (hue) of the forward scan and the backward scan is usually shifted, if the color processing is changed so that the forward scan and the backward scan have a common color gamut, the color may be different. There is a possibility that the reproduction range is narrowed and the image quality is reduced.

[0016]

SUMMARY OF THE INVENTION The present invention is directed to a method for performing color reciprocation using a recording head in which nozzles of respective colors are arranged in the scanning direction as described above, and a method for controlling color unevenness due to a difference in ejection color order. An ink jet recording method capable of improving the recording speed while reducing color unevenness even in a color recording apparatus in which the recording speed is reduced by performing only directional recording and the ink ejection order is different between reciprocation. And a recording device and the like.

[0017]

According to the recording method of the present invention, a plurality of recording element groups corresponding to inks of different color tones are provided in a direction in which the recording elements are scanned relative to a recording medium. Scanning a recording medium on the recording medium, and transporting the recording medium a predetermined amount in a direction intersecting the scanning direction, the image data corresponding to the scanning area An inkjet recording method for performing recording in accordance with the scanning direction determined according to a recording duty determined from a predetermined area, wherein the determination of the scanning direction includes determining the predetermined area as an area located near a boundary of a scanning area. An ink jet recording method is performed in accordance with the duties of at least two different areas.

Further, the recording apparatus of the present invention scans a recording medium provided with a plurality of recording element groups corresponding to inks of different colors in a direction in which the recording element is scanned relative to a recording medium. An ink jet recording apparatus for performing recording on a recording medium and performing recording in accordance with the scanning direction determined according to a recording duty determined from a predetermined area in image data corresponding to a scanning area, wherein the recording medium Means for transporting a predetermined amount in a direction intersecting the scanning direction, and the determination of the scanning direction is based on the duty of at least two areas of an area located near the boundary of the scanning area as the predetermined area and an area different from this. An ink jet recording apparatus comprising: a calculating unit configured to perform the calculation.

Further, the control device of the recording apparatus of the present invention causes the recording means provided with a plurality of recording element groups corresponding to inks of different colors in the direction of scanning relative to the recording medium to scan. And a recording device for performing recording on the recording medium and performing recording on the recording device in accordance with the scanning direction determined according to a recording duty obtained from a predetermined area in image data corresponding to a scanning area. Wherein the determination of the scanning direction is performed in accordance with the duty of at least two areas of an area located near the boundary of the scanning area as the predetermined area and an area different from the predetermined area; A transmission unit for transmitting information about a direction to the recording device side, the control device for a recording device.

Further, the storage medium of the present invention scans a recording medium provided with a plurality of recording element groups corresponding to inks of different color tones in a scanning direction relative to the recording medium. A control command for performing printing on a printing medium and causing a printing apparatus to perform printing in accordance with the scanning direction determined according to a printing duty determined from a predetermined area in image data corresponding to a scanning area is stored. A control command for calculating according to the duty of at least two areas of an area located near a boundary of a scanning area as the predetermined area, and a print duty of the plurality of areas; And a control command for determining the scanning direction in accordance with the control command.

Further, the network device of the present invention scans a recording medium provided with a plurality of recording element groups corresponding to inks of different color tones in a direction in which the recording element is scanned relative to a recording medium. A control command for performing printing on a printing medium and causing a printing apparatus to perform printing in accordance with the scanning direction determined according to a printing duty determined from a predetermined area in image data corresponding to a scanning area is stored. A network device, wherein the predetermined area is an area located near a boundary of a scanning area, a control command for calculating according to duties of at least two areas different from the area, and a printing duty of the plurality of areas. A control command for determining the scanning direction according to the following, and a transmission device for transmitting these control commands. That.

[0022]

Embodiments of the present invention will be described below.

The term "recording" used in the present invention means not only that an image having a meaning such as a character or a figure is given to a recording medium, but also that an image having no meaning such as a pattern is given. Also means.

The "recording medium" used in the present invention
As well as paper, yarn, fiber, fabric, leather, metal,
OHP sheets, plastic, glass, wood, ceramics and the like can be used.

Further, the recording device of the present invention comprises a printer,
A printer unit used for a printer, a typewriter, a copier, a facsimile having a communication system, a recording system combining a communication system and a printer unit, a word processor having a printer unit, and a combination of various processing devices. Industrial recording devices including workstations and the like.

The present invention also includes a handy or portable printer provided in a personal computer, a host computer, an optical disk device, a video device and the like.

First, points considered in forming the present invention will be described.

FIG. 1 shows a nozzle 10 for discharging black ink, cyan ink, magenta ink, and yellow ink.
The following describes an example in which a recording head in which 1k, 101c, 101m, and 101y are arranged in the scanning direction records a solid blue (blue) image of a secondary color.

FIG. 1A shows color unevenness caused by a conventional printing method, and is an example of printing a blue image in an area wider than one scan width of the print head. Since the overlapping order of the cyan ink and the magenta ink differs between the scan and the scan, color unevenness occurs for each scan width of the print head.

On the other hand, in FIG. 1B, the blue solid image is separated in the paper feed direction, and each blue image has a width that can be printed by one scan of the print head.
Also in this example, since each blue image is printed by both the forward scan and the backward scan of the printhead as shown in the drawing, color unevenness occurs for each scan width of the printhead.

However, in an actual image, FIG.
The color unevenness is more remarkable in the case of FIG. 1B than in FIG. This is because the former has higher human eye detection ability when images of different hues are adjacent to each other and when they are not adjacent to each other.

FIG. 2 shows the color difference between the forward scan and the backward scan when a continuous image is printed by the forward scan and the backward scan of the print head. The duty (ink application amount) of the continuous image is shown. Is changed as a parameter. In this figure, the applied amount of 200% means that both the cyan ink and the magenta ink are on a 1/600 inch square paper surface.
Two drops of about 8.5 pl of ink are applied, that is, about 17 drops of each ink on a 1/600 inch square paper.
pl of ink. The color difference is Lab between blue in the forward scan and blue in the backward scan.
It shows the distance in space. As is clear from this figure, the color difference is large in the region where the duty of the image is high, and the image has a clear color unevenness even when viewed.

As described above, when printing is performed by the forward scan and the backward scan of the print head, noticeable color unevenness does not always occur. That is, if images smaller than the scan width of the recording head are not adjacent to each other, color unevenness is hardly conspicuous, and conversely, even if the image is larger than the scan width of the print head, color unevenness is conspicuous unless the image duty is high. It is difficult.

The present invention is based on this characteristic. If it is determined that color unevenness is unlikely to occur from a plurality of different areas in the image data corresponding to the scanning area where printing is to be performed, forward scanning and recovery are performed. Printing is performed in both scans. On the contrary, if it is determined that color unevenness is likely to occur, printing is performed only in the forward scan or the backward scan. As the plurality of regions, it is particularly preferable to use image data corresponding to a relatively end portion of the scan width of the print head and image data corresponding to the entire scan width of the print head.

In the following embodiments, a heating element will be described as an example of a recording element for generating energy for discharging ink, but the present invention is not limited to this, and a piezoelectric element may be used. The heating element is not limited to a heating resistor, but may be any element that can generate heat and eject ink.

[0036]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, FIG. 3 shows the appearance of the ink jet recording apparatus used in this embodiment.

A carriage 11 on which an ink jet cartridge is mounted, and a carriage motor 12 for moving the carriage relatively to the recording medium in the main scanning direction.
And a flexible cable 13 for sending an electric signal from a control unit (not shown) of the ink jet device to the ink jet cartridge, a recovery unit 14 for performing a recovery process of the ink jet head unit, and a recording medium as a recording medium. Paper feed tray 15 for storing by means of an optical head and an optical position sensor 16 for optically reading the position of the carriage
Etc. The inkjet apparatus having such a configuration performs serial scanning of the carriage 11 to perform printing with a width corresponding to the ejection ports (the number of nozzles) of the inkjet head, while intersecting the recording medium with the main scanning direction during non-printing (here In this case, the sheet is intermittently conveyed by a predetermined amount in a direction perpendicular to the direction.

FIG. 141, which is an enlargement of FIG. 14, is a suction and leaving cap, 142 is a discharge receiver for receiving the processing liquid discharged at the time of recovery, 143 is a discharge receiver for receiving the ink discharged at the time of recovery. The face surface is wiped while moving in the direction of the arrow with a wiper blade for wiping the face surface.

FIG. 4 is a block diagram showing a configuration example of an electric control system of the ink jet recording apparatus shown in FIG.

Reference numeral 301 denotes a system controller for controlling the entire apparatus, in which a microprocessor and a storage element (ROM) as a storage medium storing a control program are arranged. Reference numeral 302 denotes a driver for driving the recording head in the main scanning direction. Reference numerals 304 and 305
Are motors corresponding to the drivers 302 and 303, respectively, and operate by receiving information such as speed and moving distance from the drivers.

Reference numeral 306 denotes a host computer, which is a device having transmission means for transferring information to be recorded to the recording device of the present invention. In addition to a computer as an information processing device,
It may be in the form of an image reader or the like.

Reference numeral 307 is a buffer for temporarily storing data from the host computer 306, and stores received data until data is read from the system controller 301.

Reference numeral 308 (308k, 308c, 3
08m, 308y) is a frame memory for developing data to be recorded into image data, and has a memory size required for recording for each color. Here, a frame memory capable of recording one sheet of recording paper will be described, but it goes without saying that the present invention is not limited to the size of the frame memory. Reference numeral 309 (3
09k, 309c, 309m, and 309y) are storage elements for temporarily storing data to be recorded, and the recording capacity changes according to the number of nozzles of the recording head.

Reference numeral 310 denotes a recording control section for appropriately controlling the recording head in accordance with a command from the system controller 301, and for controlling the recording speed, the number of recording data, and the like. Reference numeral 311 denotes recording heads 17k and 17c for discharging ink.
A driver for driving 17m and 17y is controlled by a signal from the recording control unit 310.

In the above configuration, the image data supplied from the host computer 306 is
7 is temporarily stored and developed in a frame memory for each color. Next, the developed image data is read by the system controller 301 and developed in the buffer 309. The recording control unit 310 controls the operation of the recording heads 17k, 17c, 17m, and 17y based on the image data in each buffer and the processing liquid.

A specific example of a recording method performed by the ink jet recording apparatus having the above configuration will be further described.

(First Embodiment) Hereinafter, a first embodiment of the present invention will be described.

FIG. 5 is a view of the recording head used as the recording means used in the present embodiment, as viewed from the ejection port side, and has a row of 300 ejection ports at a density of 600 per inch and different color tones. For each ink, a recording head 17k for discharging black ink, a recording head 17c for discharging cyan ink,
A recording head 17m for ejecting magenta ink and a recording head 17y for ejecting yellow ink are separately arranged in the scanning direction of the recording head.

An ink liquid path is provided for each ejection port, and a recording element for generating energy for ejecting ink is provided for each ejection port.

The ejection amount of the ink ejected from the ejection port is about 30 ng for black ink and about 15 ng for other inks.
ng. Here, the ejection amount of the black ink is increased in order to realize a high density.

Next, a method for detecting whether or not color unevenness occurs in each scan when an image is printed by alternately repeating the forward scan and the backward scan of the print head will be described.

FIG. 6 (a) shows a predetermined area of image data in an image area (scanning area: one band) of (scanning width of recording head x 300 dots (recording width of recording head)) to be recorded. This shows a method of calculating the recording duty, and here shows a case where two windows are used as a plurality of windows.
A window B62 for calculating the duty near the boundary of the image area (boundary between different bands) is prepared, and the recording duty in the window is calculated from the image data in this window while scanning the window in the image area. I do.

The window A61 has a horizontal resolution of 1
This is for calculating the print duty over the entire print width of the print head (duty over the entire width of the image area in the recording medium transport direction) with a size of 600 dots per inch = 600 dpi. The window is 128 dots wide.

The window B is used to calculate the print duty of an area near the boundary of the image area to be printed by each scan (the boundary with the adjacent band). In this embodiment, the size of the window is 32 dots by 128 dots. Window.

Regarding the position and size of the window, in the case of the window B62, it is sufficient to set the recording duty near the end of the band, that is, near the boundary between the bands, and the position is set to 0.5 mm from the boundary 63. It is desirable that the recording duty be within the range from the position of about 5 mm to the printing duty in the range on the boundary 63 side. Further, it is desirable to set the position so that the printing duty of the dot closest to the boundary 63 is included. However, the position may be set by removing several dots from the boundary 63.

In the case of the window A61, it is desirable that the window has a width capable of reading the duty of the entire width (band width) in the direction orthogonal to the scanning direction of the head.
It is sufficient if the recording duty of the bandwidth is reflected, and the boundary 6
The position may be set by removing several dots from 3.

The length of the windows A and B in the head scanning direction (the length direction of the band) is set to 128 dots, but is not limited to this, and may be any length that allows easy calculation of the recording duty of the window. I just need.

In the above-described windows A and B, the number of image data to be calculated in each window is different in this embodiment. In window A, calculation is performed with a relatively large number of image data in order to capture the average density distribution in the scanning area. In window B, the relative density is calculated in order to capture the local density distribution at the boundary. The calculation is performed with a relatively small number of image data.

However, this point can also be obtained by specifying the window at a position that reflects the boundary and the bandwidth as described above, so that the effect can be obtained. It does not have to be a relationship.

The calculation of the print duty in these windows is performed by the print control unit using the image data stored in the buffer 309.

FIG. 6 shows a window scanning method.
As shown in (b), a scanning method in which each window is shifted by one line in the scanning direction of the recording head (the length direction of the band) to calculate the recording duty, or as shown in FIG. Alternatively, a scanning method may be used in which the printing duty is calculated by shifting the length of each window in the band length direction (every 128 dots in the horizontal direction in this embodiment).

The recording duty Dc of the cyan image, the recording duty Dm of the magenta image, and the recording duty Dy of the yellow image in the window are counted, and the sum Dc + Dm + Dy is set as the recording duty in the window at a certain window position.

In this embodiment, the threshold value of the recording duty of each window is set to 125% for window A and 100% for window B. Here, the recording duty of 100% is defined as when one dot of the color ink is recorded at a pixel position of 1/600 inch × 1/600 inch. Therefore, for example, an image of 100% cyan indicates that the area is filled with cyan dots, and 200% is, for example, a solid blue image and is completely filled with cyan and magenta dots. Point to.

That is, the recording duty refers to the ratio of the coloring material provided in the unit recording area, and is 100% at the maximum for the temporary color and 200% at the maximum for the secondary color.

The recording duty of the window A is 125% at all positions in the recording area where recording is to be performed.
If the print duty of the window B at all positions satisfies the condition of 100% or less, printing (reciprocal printing) is performed in both forward scanning and backward scanning to increase the printing speed. If even one of the conditions is not satisfied, printing (one-way printing) is performed in either the forward scan or the backward scan to reduce uneven printing.

The reason why the threshold value of the recording duty of the window A is smaller than the threshold value of the window B in the present embodiment is that the window B has a recording duty at the boundary portion, so that even small unevenness tends to be conspicuous. On the other hand, if the threshold value of the window A is made smaller and stricter, on the other hand, the ratio of one-way printing becomes too large, and the printing speed is reduced.

FIG. 7 is a flowchart of the above operation. First, in step 1, printing is performed in the first scan (n = 1) of the print head according to image data. In this embodiment, the scanning direction at this time is described as an example in which the scanning direction starts from the home position side of the recording head (the recovery unit side in FIG. 3), but the scanning direction is not limited to this.

Subsequently, in step 2, n = n + 1 is set in order to proceed to the next scan (recording of the second band).

In step 3, the window A and the window B at a certain position of the next scan (for example, the second scan)
Is calculated from the recording duty of each color,
In step 4, the recording duty of window A is 125
% Is determined. If it is less than 125%, the process proceeds to step 5, and if it exceeds 125%, the process proceeds to step 7. If it is less than 125%, the process proceeds to step 5, where it is determined whether or not the print duty of the window B is less than 100%.
If it exceeds, go to step 7. In step 6, printing in the direction opposite to the previous (here, first scanning) printing direction is performed.
That is, a setting is made to perform reciprocal recording. In step 7, a setting is made to perform recording in the same direction as the previous recording direction, that is, one-way recording.

After step 6, it is determined in step 8 whether each window has completed all shifts within n bands,
If not, the window is shifted to the next position in step 9. After the shift, the process returns to the step 3, and the reading calculation is performed until there is no place where the recording duty exceeds the reference value until the entire shift is completed.

If no window exceeds the reference value even after all shifts of the window are completed, the (n
-1) Perform recording in the direction opposite to the band (step 1)
0).

When recording in the same direction as the previous band is set in step 7, in this embodiment, recording is performed without calculating the recording duty of the next window.

The above operation is repeated until all recording is completed.

FIG. 8 explains an example to which this embodiment is applied. Here, data of six bands from n = 1 to 6 is shown, and the recording duty of each band is shown by a graph of shading and duty on the right side.

First, in the first scan (n = 1), printing is performed in the forward scan. In the subsequent second scan, the print duty of the window A61 and the print duty of the window B62 are calculated. Here the highest recording duty is 80% for both
It is assumed that the recording duty is.

As a result, the recording direction of the second scan is opposite to that of the first scan, and recording is performed in the backward scan. However, since the recording duty is low at the boundary between the first scan and the second scan, color unevenness occurs. Inconspicuous.

Next, in the third scan, the print duty of window A is 115%, and the print duty of window B is 8%.
It is assumed that the calculated value is 0%. As a result, the printing direction of the third scan is opposite to that of the second scan, and printing is performed in the forward scan. However, since the print duty is low at the boundary between the second scan and the third scan, color unevenness is not conspicuous.

In the fourth scan, it is assumed that the print duty of window A is calculated to be 115% and the print duty of window B is calculated to be 150%. As a result, the recording direction of the fourth scan is the same as that of the third scan, and recording is performed in the forward scan, so that color unevenness does not occur at the boundary between the third scan and the fourth scan.

In the subsequent fifth scan, the print duty of window A is 150%, and the print duty of window B is 8%.
It is assumed that the calculated value is 0%. As a result, the printing direction of the fifth scan is the same as that of the fourth scan, and printing is performed in the forward scan, so that color unevenness does not occur at the boundary between the fourth scan and the fifth scan.

In the last sixth scan, it is assumed that the print duty of window A is calculated to be 150% and the print duty of window B is calculated to be 175%. As a result, the printing direction of the sixth scan is the same as that of the fifth scan, and printing is performed in the forward scan, so that color unevenness does not occur at the boundary between the fifth scan and the sixth scan.

As described above, according to this embodiment, the print duty of a predetermined area in the scan for printing is calculated from now on, reciprocal printing is performed when the print duty is low, and unidirectional printing is performed when the print duty is high. Since recording is performed, an image with less noticeable color unevenness can be recorded in a short time, that is, at a high speed.

In the present embodiment, if the calculated value exceeds the reference value before the end of the entire shift of the window, the recording direction is determined and recording is performed without performing subsequent calculations. After all shifts have been completed, recording may be started.

(Second Embodiment) When red, green, and blue secondary color images are recorded in a reciprocating manner, the degree of occurrence of color unevenness due to forward scan and backward scan differs. This is considered to be due to the time difference of the color superposition due to the characteristics of the ink and the physical distance between the heads of each color. In consideration of this, when calculating the print duty in the predetermined area, in addition to simply adding the print duty for each color, and calculating the print duty for a specific color, higher quality images can be obtained. High-speed recording becomes possible.

In this embodiment, an example of control in consideration of such a secondary color image is shown.

For example, referring to FIG. 9, a description will be given of a flow in a case where a secondary color image having the same duty is recorded in a reciprocating manner and green in which color unevenness is more conspicuous than red and blue is considered.

Since the steps up to the third step are the same as those in the first embodiment, the description is omitted.

In step 4, first, the green recording duty Dc +
Calculate Dy. If not more than 125%, step 5
If the value exceeds 125%, the process proceeds to step 9. In step 5, the total recording duty Dc + Dm + Dy in the window A at the same position is calculated, and 150
If it is less than 150%, the process proceeds to step 6. If it exceeds 150%, the process proceeds to step 9.

In steps 6 and 7, the green print duty and the total print duty in window B at a certain position are calculated. Green recording duty is 10
Only when the recording duty is 0% or less and the total recording duty is 125% or less, the process proceeds to step 8. In Step 8, (n-1)
Step 9 is set so that recording is performed in the direction opposite to the scanning.
In this case, it is set so that printing is performed in the same direction as the (n-1) scan.

After step 8, it is determined in step 10 whether or not the window has shifted all positions in the n band. If not, the window is shifted by one in step 11; Make a record.

As is clear from the above description, for a green image in which color unevenness is easily conspicuous, the recording duty is checked and the recording operation is performed in the same manner as in the first embodiment, but the color unevenness is relatively inconspicuous. Since the threshold value is set high for blue, red, or a mixed image of three colors, printing is performed in both the forward scan and the backward scan even when the duty is higher than in the first embodiment. Recording becomes possible.

(Third Embodiment) FIG. 10 shows a window in the present embodiment. The difference from the first embodiment is that the window B101 is located near the upstream end of the recording medium in the transport direction. The print duty of the area is calculated. As is clear from the figure, the vertical size of the window B is 48 dots including 32 dots at the end of the scan to be recorded and 16 dots at the end of the next scan, and the first size in the horizontal direction. 128 dots, which is the same as in the embodiment.

The difference from the first embodiment is that, as described above, the window B is provided in the area near the end on the upstream side in the transport direction of the recording medium, and the duty in this window B is calculated. The scanning direction of the band next to the band related to the duty calculation is determined in consideration of the print duty.

FIG. 11 shows a flow chart of the present embodiment. In step 1, n = 1 is set, and in step 2, the window A and the window A at a certain position of the n-th scan (for example, the first scan) are set. The print duty of the window B is calculated from the print duty of each color. In step 3, it is determined whether or not the recording duty of the window A is 125% or less.
If it exceeds, go to step 6. When the process proceeds to step 4, it is determined whether or not the print duty of the window B is 100% or less. When the print duty is less than 100%, the process proceeds to step 5, and when it exceeds 100%, the process proceeds to step 6.

In step 5, the recording direction of the (n + 1) th scan (for example, the second scan) is changed to the nth scan (here, the first scan).
Scan). Next, as in the previous embodiment, it is determined in step 7 whether or not all the windows have been shifted. If not, the process proceeds to step 8 to shift the window and return to step 2. on the other hand,
In step 6, the (n + 1) th scan (here, the second scan)
Is determined to be the same direction as the n-th scanning (here, the first scanning).

Thereafter, the recording of the n-th band is executed in step 7 (step 10). In step 11, it is determined whether or not all printing has been completed. If not completed, in step 9, n = n + 1, and the process proceeds to the next scanning. The above is repeated until the recording is completed.

FIG. 12 explains an example to which the present embodiment is applied. The expression in FIG.
According to.

First, in the first scan (n = 1), the print duty of the window A121 and the print duty of the window B121 are calculated. Here, it is assumed that both windows have a recording duty of 80%. As a result, after it is determined that the recording direction of the second scan is the opposite direction to the first scan, first, the first scan is recorded in the forward scan.
Here, the first scan may start printing in the forward scan or may start printing in the backward scan. However, if the first scan is started from the forward scan, the second scan is the same as the printing in the backward scan. Become.

In the subsequent second scan, the print duty of window A and the print duty of window B are calculated. Here, it is also assumed that all the windows have a recording duty of 80%. As a result, the printing direction of the third scan is
After the scan is performed in the opposite direction and it is determined that the recording is in the forward scan,
The recording of the second scan is performed. Since the printing duty is low at the boundary between the first scan and the second scan, color unevenness is not conspicuous.

Next, in the third scan, the print duty of window A is 115% and the print duty of window B is 1%.
It is assumed that 50% is calculated. As a result, the recording direction of the fourth scan becomes the same direction as the third scan, and it is determined that the recording is performed in the forward scan. Then, the recording of the third scan is performed. However, the boundary between the second scan and the third scan is also determined. Since the recording duty is low, color unevenness is not conspicuous.

In the fourth scan, it is assumed that the print duty of window A is calculated to be 115% and the print duty of window B is calculated to be 80%. As a result, the printing direction of the fifth scan is opposite to that of the fourth scan, and it is determined that printing is performed in the backward scan. Thereafter, printing of the fourth scan is performed, but the color at the boundary between the third scan and the fourth scan is determined. Unevenness does not occur because the recording directions are the same.

In the subsequent fifth scan, the print duty of window A is 150% and the print duty of window B is 1
It is assumed that the calculated value is 75%. As a result, the printing direction of the sixth scan is the same as that of the fifth scan, and it is determined that printing is performed in the backward scan. Thereafter, printing of the fifth scan is performed, but the boundary between the fourth scan and the fifth scan is printed. Since the duty is low, color unevenness does not occur.

In the last sixth scan, it is assumed that the print duty of window A is calculated as 150% and the print duty of window B is calculated as 80%. As a result, the printing direction of the sixth scan becomes the same direction as the fifth scan, and it is determined that printing is performed in the backward scan. Thereafter, printing of the sixth scan is performed. However, the color at the boundary between the fifth scan and the sixth scan is changed. Unevenness does not occur because the recording directions are the same.

As described above, in this embodiment, the direction of the next scan is determined based on the data of the scan to be printed. The example shown in FIG. 12 has the same image as the first embodiment shown in FIG. 8, but as a result, the fifth and sixth scanning directions are different from those of the first embodiment. However, in either case, since color unevenness between scans can be suppressed, it can be said that either method may be used.

(Other Embodiment 1) In the first and second embodiments, image data is present in the window B, and as a result, the feed amount of the recording medium is 300 nozzles, which is the recording width of the recording head. However, when the recording duty of the window B is 0%, that is, when there is no image data, the recording medium may be further conveyed by that amount.

Further, the size of the window is not limited to the first size. For example, as shown in FIG. 13A, the size of the window may be smaller than that of the first embodiment.
As shown in FIG. 3B, the scanning may be performed over the previous or next scanning beyond the scanning width. In the case of FIG. 13B, the occurrence of color unevenness at the boundary of scanning can be detected with higher accuracy.

(Other Embodiment 2) In each of the above embodiments, the calculation of the printing duty using the window is performed by the printing control unit 310 based on the data held in the buffer 309 (FIG. 4) in the printing apparatus. Although an example of performing the processing has been described, the present invention is not limited to this, and the processing may be performed on the host computer 306 side as a device for controlling the printing apparatus, that is, by a pudding and a driver.

In this case, the host computer 309
The print duty of the band to be printed in each scan is calculated using the window as in the above-described embodiments, and the scan direction of each band is determined. And
The recording may be performed by transmitting the recording data from the host to the recording device together with or separately from the host by the transmission means of the host computer.

Control commands such as programs for performing the processing of each embodiment as described above may be held in the recording apparatus as in the previous embodiment, but may be stored in the host computer as in this embodiment. May be held. The present invention is not limited to this, and may be stored in various types of storage media. The above-described processing may be performed by reading a control command or the like from this storage medium before or during processing.

As a storage medium, any medium, such as a floppy disk, CD-ROM, MO, MD, or DVD, which can store control commands and can be read out to the outside, regardless of magnetic storage or optical storage, can be used. Storage medium. Further, the storage medium is not limited to a storage medium which can be easily detached from the reading apparatus as described above, and may be a packaged ROM attached to the apparatus.

The above-mentioned control command may be held in the network device 160 as shown in FIG. 16, and this control command is transmitted to the host computer connected to the network device by using the transmission means of the network device. You may make it transfer via a network.

[0112]

As described above, according to the present invention,
In a printing apparatus in which print heads for ejecting each color ink are arranged in the scanning direction, in order to calculate a print duty from image data in a predetermined area to determine a print direction, when it is determined that color unevenness is unlikely to occur. High-speed recording becomes possible by performing reciprocating recording. If it is determined that color unevenness is likely to occur, it is possible to perform one-way printing and minimize the reduction in printing speed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating color unevenness when performing reciprocal printing.

FIG. 2 is a diagram showing an ink ejection amount and color unevenness;

FIG. 3 is a diagram illustrating a schematic configuration of an ink jet recording apparatus used in an embodiment.

FIG. 4 is a diagram illustrating a block configuration of an ink jet recording apparatus used in an embodiment.

FIG. 5 is a diagram illustrating a configuration of a recording head used in an embodiment.

FIG. 6 is a view for explaining a window for calculating a print duty in the first embodiment.

FIG. 7 is a view for explaining an operation flow in the first embodiment;

FIG. 8 is a diagram illustrating a recording operation according to the first embodiment.

FIG. 9 is a view for explaining an operation flow in the second embodiment;

FIG. 10 is a view for explaining a window for calculating a print duty in the third embodiment.

FIG. 11 is a view for explaining an operation flow in the third embodiment;

FIG. 12 is a diagram illustrating a recording operation according to a third embodiment.

FIG. 13 is a view for explaining another example of a window for calculating a recording duty.

FIG. 14 illustrates a configuration of a recording head.

FIG. 15 illustrates a configuration of a recording head.

FIG. 16 illustrates a network configuration.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Daigoro Kanematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C056 EA01 EA11 EB29 EB58 EC11 EC28 EE03 EE10 FA03 FA04 FA10 FA11 HA07 KD10 2C057 AF05 AF91 AG12 AG44 AG46 AL31 AL40 AM40 AN01 AN02 DA06 DB01 DB03 DC08

Claims (31)

[Claims] 1. A printing unit having a plurality of printing element groups corresponding to inks of different colors in a scanning direction relative to a printing medium is scanned to perform printing on the printing medium. And a step of transporting the recording medium by a predetermined amount in a direction intersecting the scanning direction, wherein the recording medium is determined based on a printing duty obtained from a predetermined area in image data corresponding to a scanning area. An inkjet recording method for performing recording in accordance with a scanning direction, wherein the determination of the scanning direction is performed in accordance with a duty of at least two regions of a region located near a boundary portion of the scanning region as the predetermined region and a region different from the region. An ink jet recording method characterized by being performed by: 2. The ink jet recording method according to claim 1, wherein the scan in which the scan direction is determined is a scan of a scan area where the print duty is calculated. 3. The ink jet printing method according to claim 1, wherein the scan in which the scan direction is determined is a scan in which printing is performed next to a scan of a scan area in which the print duty is calculated. 4. The recording medium having a first area including substantially the entire area of the scanning area in a direction intersecting with the scanning direction as the plurality of areas, and the scanning width of the scanning area. 3. The ink jet recording method according to claim 2, wherein the calculation is performed in a second area near the end on the downstream side in the conveyance direction. 5. The recording medium having a first area including substantially the entire width of the scanning area in a direction intersecting the scanning direction as the plurality of areas, and the scanning width of the scanning area. 4. The ink jet recording method according to claim 3, wherein the calculation is performed in a second area near the end on the upstream side in the conveyance direction. 6. The ink jet recording method according to claim 1, wherein the plurality of different areas have different numbers of image data included in the areas. 7. The printing apparatus according to claim 1, wherein when the print duty of at least one of the plurality of areas is higher than a predetermined reference value, printing is performed in the same scanning direction as that in which printing was previously performed. An ink-jet recording method according to claim 6. 8. The ink jet recording method according to claim 7, wherein the reference value differs between the plurality of areas. 9. The ink jet recording method according to claim 8, wherein a reference value of a recording duty in an area near the end is set lower. 10. The ink jet printing method according to claim 1, wherein the print duty obtained by the calculation is a sum of print duties for each color. 11. The ink jet printing method according to claim 1, wherein the print duty in the predetermined area is a sum of print duties of a specific color. 12. The ink jet recording method according to claim 1, wherein the step of calculating the recording duty is a step of performing the calculation while sequentially shifting each of the plurality of areas in the scanning area. . 13. The recording element according to claim 1, wherein the recording element is a heating element that ejects an ink droplet by causing a state change in the ink using thermal energy. Ink jet recording method. 14. The ink jet recording method according to claim 1, wherein the recording element is a piezoelectric element that ejects ink droplets by mechanical displacement. 15. Recording on a recording medium by scanning a recording unit having a plurality of recording element groups corresponding to inks of different colors in a direction in which the recording elements are scanned relative to the recording medium. And an ink jet recording apparatus that performs recording in accordance with the scanning direction determined according to a recording duty determined from a predetermined area in image data corresponding to the scanning area, wherein the recording medium intersects the scanning direction. Means for transporting a predetermined amount in the direction, and determining the scanning direction comprises: an area located near the boundary of the scanning area as the predetermined area; and a calculating means configured according to the duty of at least two areas different from this. Characteristic inkjet recording device. 16. The ink jet printing apparatus according to claim 15, wherein the scan in which the scan direction is determined is a scan of a scan area in which the print duty has been calculated. 17. The ink jet printing apparatus according to claim 15, wherein the scan in which the scan direction is determined is a scan in which printing is performed next to a scan in a scan area in which the print duty has been calculated. 18. The calculation means as the plurality of regions,
A first area including substantially the entire width of the scanning area in a direction intersecting with the scanning direction, and a first area including a scanning width of the scanning area near an end on a downstream side in a conveying direction of the recording medium. 17. The ink jet recording apparatus according to claim 16, wherein the means performs calculation in the second area. 19. The calculating means as the plurality of areas,
A first area including substantially the entire width of the scanning area in a direction intersecting with the scanning direction, and a first area including a width of the scanning area in the scanning area near an end of the recording medium on the upstream side in the transport direction. 18. The ink jet recording apparatus according to claim 17, wherein the means performs calculation in the second area. 20. The inkjet recording method according to claim 15, wherein the plurality of different areas have different numbers of image data included in the areas. 21. When the print duty of at least one of the plurality of areas is higher than a predetermined reference value, the determination means determines that printing is performed in the same scanning direction as that in which printing was previously performed. The ink jet recording apparatus according to any one of claims 15 to 20, which is means. 22. A different reference value is set as the reference value among the plurality of regions in the determination unit.
2. The ink jet recording apparatus according to 1. 23. The ink jet recording apparatus according to claim 22, wherein a reference value of a recording duty in an area near the end portion is set lower. 24. The ink jet printing method according to claim 16, wherein said calculating means calculates a sum of print duties for each color. 25. The apparatus according to claim 1, wherein said calculating means is means for calculating a sum of print duties of a specific color.
7. The ink jet recording apparatus according to 6. 26. An ink jet recording apparatus according to claim 16, wherein said calculating means is means for performing calculation while sequentially shifting each of said plurality of areas in said scanning area. 27. The ink jet recording apparatus according to claim 15, wherein the recording element is a heating element that ejects ink droplets by causing a state change in the ink using thermal energy. 28. An ink jet recording apparatus according to claim 15, wherein said recording element is a piezoelectric element for ejecting ink droplets by mechanical displacement. 29. Recording is performed on a recording medium by scanning a recording unit provided with a plurality of recording element groups corresponding to inks of different colors in a direction in which the recording element is scanned relative to the recording medium. A control device that causes a printing apparatus to perform printing in accordance with the scanning direction determined in accordance with a printing duty determined from a predetermined area in image data corresponding to a scanning area; Calculating means configured in accordance with duties of at least two areas of an area located near the boundary of the scanning area as the predetermined area and an area different from the scanning area;
Transmitting means for transmitting the information on the determined scanning direction to the printing apparatus side, a control apparatus for the printing apparatus. 30. Recording on a recording medium by scanning a recording unit provided with a plurality of recording element groups corresponding to inks of different colors in a direction in which the recording elements are scanned relative to the recording medium. A storage medium storing a control command for causing a printing apparatus to perform printing in accordance with the scanning direction determined according to a printing duty determined from a predetermined area in image data corresponding to a scanning area, An area located near the boundary of the scanning area as the predetermined area, a control command for calculating according to the duties of at least two areas different from the area, and the scanning direction according to the recording duty of these areas. A storage medium storing a control command to be determined and 31. A recording means provided with a plurality of recording element groups corresponding to inks of different colors in a direction in which the recording elements are scanned relative to a recording medium, performs recording on the recording medium. A network device storing a control command for causing a printing apparatus to perform printing in accordance with the scanning direction determined in accordance with a printing duty determined from a predetermined area in image data corresponding to a scanning area, An area located near the boundary of the scanning area as the predetermined area, a control command for calculating according to the duties of at least two areas different from the area, and the scanning direction according to the recording duty of these areas. A network device comprising: control commands to be determined; and transmission means for transmitting these control commands.