JP2003001803A - Apparatus and method for recording control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for a serial scanning type recording control which can reduce joining streaks which are most conspicuous of all density fluctuations with a relatively simplified structure to obtain a stable image all the times. SOLUTION: Among a plurality of patterns recorded on a plurality of correction tables, a proper table is set. While, the number of recording dots at the joining portion between respective recording scans is adjusted on the set table to match the density at the joining portion to that at other portions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial scan type recording control apparatus and recording control method, and more particularly to a method of reducing density unevenness called a connecting line.

[0002]

2. Description of the Related Art There is a recording device (hereinafter, also referred to as a printer) as a device for outputting images, characters and the like. In addition to a monochrome printer that records in black only,
Cyan (C), magenta (M), yellow (Y) 3
There are color printers that record in four colors, or four colors in which black (K) is added. Various systems such as an inkjet recording system, an electrophotographic recording system, a thermal transfer recording system, and a sublimation recording system have been developed for such a recording apparatus.
Among them, the ink jet recording method is particularly attracting attention as an apparatus that is inexpensive and can perform quiet, high speed and high resolution recording.

The ink jet recording method uses a heating element or a piezoelectric element as an ejection energy generating element,
This is a method in which recording is performed by ejecting ink from nozzles and attaching the ink to a recording medium. This recording device is classified into a full multi type and a serial scan type. The full-multi type is a type in which recording is performed while a recording head having a plurality of nozzles as wide as the recording medium is used and the recording medium is relatively conveyed in a direction different from the direction in which the nozzles are arranged. On the other hand, the serial scan type uses a print head in which a plurality of nozzles are arranged in the transport direction of a print medium, and a main scan for printing and scanning the print head in a direction different from this, and a predetermined amount of paper between each main scan. The image is completed by alternately performing sub-scanning for carrying. At present, the latter serial scan type is predominant because it is inexpensive and small.

By the way, in the ink jet recording apparatus,
There is some variation in the ink ejection amount and ejection direction of each nozzle, the conveyance amount of the recording medium, and the like. Due to this variation, it may be perceived as density unevenness on the image. In particular, in the serial scan type, a sub-scan is performed between each print scan, and therefore, when an image is printed, a connecting portion is always generated between print scans. The periodic black streaks and white streaks that occur at the joints are particularly noticeable and have been an image problem called joint streaks.

In order to reduce the connecting stripes, it is sufficient to eliminate the above-mentioned variation, but this is very difficult in manufacturing the recording apparatus.

Even if there is no variation, black streaks are likely to occur in a recording medium such as plain paper into which ink easily penetrates.

FIG. 1 is a model diagram showing the above phenomenon.
In the case of a recording medium that easily absorbs ink, the ink ejected in the first recording scan penetrates into the medium in a relatively short time as shown in FIG. After transporting the recording medium, the second
When a recording scan (scan next to the first scan) is performed,
As shown in (b), the ink in the first recording scan has already finished permeating, and the ink in the connecting portion ejected in the second scanning is attracted to the ink in the first recording scan. Therefore, as shown in the figure, a high density portion in which ink is collected occurs at the boundary between the two. This high-density boundary portion becomes a black streak and appears regularly in each recording scan cycle, which is easily perceived and causes a problem on the image.

As a method of correcting such periodic density unevenness, there is, for example, Japanese Patent Laid-Open No. 05-220977. Here, after printing the test pattern on the print head, the density unevenness of the test pattern is read by the sensor, and the raster data corresponding to each nozzle is corrected to eliminate the density unevenness on the image.
A so-called head shading method is disclosed. According to this method, it is possible to eliminate density unevenness that periodically appears in the sub-scanning direction, such as variations in the ejection amount and ejection direction of the nozzles, or connecting stripes.

As another method, by masking the actual image data to reduce the number of print data for each print scan, masks complementary to each other are sequentially switched, and a plurality of print scans are performed. There is a division recording method that completes an image. According to this method, the amount of paper feed performed during each print scan is set to a width smaller than the number of nozzles, so that the variations in nozzles and the harmful effects of connecting lines are dispersed without concentrating in one place. It Therefore, it is possible to record an image that is relatively uniform and has no density unevenness. In this divisional recording method, the greater the number of divisions (the number of passes), the greater the degree of dispersion and the higher quality recording becomes possible.

[0010]

However, the above-described head shading method does not particularly focus only on the connecting stripes, but mainly aims to reduce the density unevenness in the entire recording width. The effect of reducing was small.

Further, in the divided recording method, since the carry amount, the discharge amount, and the discharge direction variations due to individual differences are not taken into consideration, the effect of reducing the connecting stripes varies from individual to individual, and a sufficient effect can be obtained. Didn't. Further, since the number of divisions increases, the number of print scans increases, and the print time (throughput) also increases significantly. On the other hand, it was not possible to deal with the reduction of the connection stripes at the time of high-speed recording (division number = 1).

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to reduce the particularly conspicuous connecting streak in density unevenness with a relatively easy structure and to always stabilize the density. A recording control device and a recording control method of a serial scan type for obtaining an image are provided.

[0013]

To this end, according to the present invention, a main scanning in which a recording head in which a plurality of recording elements are arranged in parallel is moved in a direction different from the direction in which the recording elements are arranged in parallel, and the main scanning is performed. In a recording control device for recording an image on the recording medium by repeating sub-scanning in which the recording medium is conveyed relative to the recording head in a different direction, a boundary that is connected by two main scans is included. Extraction means for extracting an area having a width of a predetermined number of continuous pixels in the sub-scanning direction as a joint area, a plurality of correction tables for correcting the number of recording pixels in the joint area, and a plurality of the correction tables. According to each of the above, a plurality of test pattern recording means for recording a plurality of test patterns, and a plurality of the correction tables of the plurality of correction tables determined from the recorded test patterns. One and a setting means for setting a to and recording an image in accordance with the correction table set by said setting means.

Further, a main scan for performing recording while moving a recording head in which a plurality of recording elements are arranged in parallel in a direction different from the direction in which the recording elements are arranged in parallel, and a relative direction with respect to the recording head in a direction different from the main scanning. In the recording control method for recording an image on the recording medium by repeating the sub-scan for transporting the recording medium, a width including a boundary connected by two main scans and having a predetermined number of consecutive pixels in the sub-scanning direction. The area having a is extracted as a connecting area, a plurality of correction tables for performing correction for increasing or decreasing the number of recording pixels in the connecting area are prepared, and according to each of the plurality of correction tables, a plurality of test patterns are recorded, One of the plurality of correction tables determined from the recorded test pattern is set, and an image is recorded according to the set correction table. And wherein the door.

With the above arrangement, it is possible to set an appropriate table in a timely manner from a plurality of patterns recorded in a plurality of correction tables. Further, in the set table, it is possible to adjust the number of print dots in the connecting portion between the respective print scans so that the density of the connecting portion can be adjusted to that other than the connecting portion. Therefore, it is possible to provide a recording control apparatus and a recording control method that can always obtain a uniform image without a connection stripe regardless of individual differences of the recording apparatus, the recording head, and the like.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) <Outline of Recording Apparatus> FIG. 2 is a perspective view of an ink jet recording apparatus used in this embodiment. In FIG. 2, 1 is paper,
Alternatively, it is a recording medium such as a plastic sheet. A plurality of recording media 1 stacked in a cassette or the like is first supplied one by one into a recording device by a paper feed roller (not shown). The first transport roller pair 3 and the second transport roller pair 4 are
The recording media 1 are arranged at regular intervals and are driven by respective stepping motors (not shown) to carry the fed recording medium 1 in the direction of arrow A.

Ink jet recording heads 5a to 5d eject different ink colors onto the recording medium 1. Reference numeral 6 is a carriage, and the recording heads 5a to 5d
In addition, an ink tank (not shown) that supplies ink of each color is mounted on it. The carriage 6 is connected to a carriage motor 23 via a belt 7 and pulleys 8a and 8b. In this way, the carriage motor 23 is driven so that the carriage 6 can reciprocate in the direction of arrow B along the guide shaft 9.

At the time of recording, the recording heads 5a to 5d are
The recording medium 1 is moved in the direction of arrow B according to the image signal.
Ink is ejected onto the recording medium (printing main scan). After this one print scan is completed, the conveying roller pairs 3 and 4 are driven to drive the print medium 1
Is conveyed in the direction of arrow A by a predetermined amount (sub scanning). The image is gradually completed on the recording medium 1 by alternately repeating the main scanning and the sub-scanning.

Reference numeral 2 denotes a recovery device for the recording heads 5a to 5d, which is installed at the home position which is the position shown in the figure. The recording heads 5a to 5d return to their home positions as necessary, and the recovery device 2 eliminates or prevents clogging of the nozzles.

FIG. 3 is a block diagram showing a control system for driving each member of FIG. The control unit 20 has a CPU 2
0a, ROM 20b, RAM 20c, and the CPU 20a can be realized by a microprocessor or the like. The ROM 20b stores a control program for the CPU 20a and various data. The RAM 20c is the CPU 2
It is used as a work area of 0a and temporarily stores various data such as recorded image data.

Reference numeral 21 is an interface, 22 is an operation panel, and 29 is an external device. 23 is a motor for driving a carriage, 24 is a motor for driving a paper feeding motor, and 25 is a first motor.
A motor for driving the conveying roller pair, 26 is a motor for driving the second conveying roller pair, and 27 is these motors 23 to 26.
Is a driver for driving. Reference numeral 5 is the same as the recording head 5 in FIG. 2, and 28 is a driver for driving the recording head 5.

The control unit 20 receives various information (for example, character pitch, etc.) from the operation panel 22 via the interface 21.
I / O such as character type) or an image signal with the external device 29
O (input / output of information) is performed. Also, interface 2
O for driving each motor 23-26 via
N, OFF signals and image signals are output to drive each member. Particularly, in the CPU 20a, the image data to be printed by the print head 5 in one print scan is sent for each print scan.

FIG. 4 is an explanatory view of the connecting portion. In this figure, circles are dots given to the recording medium. The joint portion refers to a recording area composed of a plurality of rasters that sandwiches a boundary line (joint) between two continuous recording scans such as the first scan and the second scan. In the present embodiment, the area expanded by 4 rasters above and below the boundary is used as the connecting portion, but the width and position of the area are not limited to this. It is only necessary to adjust the visibility of the connecting part by increasing or decreasing the number of recording dots in the area, so it is sufficient to set an appropriate width for each recording device, and the rasters above and below the boundary line are not necessarily the same number. Good.

The CPU 20a extracts only the data contained in this area from the recording data, and performs the connecting process described later. Data that does not correspond to the connecting portion is transferred as normal ejection data according to the image data from the host computer.

<Outline of Image Processing> Next, an image processing method of print data generated by the host computer will be described.

FIG. 5 is a block diagram of an image processing system to which the present invention is applied. In FIG. 5, the host 201 is a CP
It has an interface with the U, memory, external storage, input unit, and recording device. The CPU executes a program stored in the memory to implement color processing, quantization processing, and the like, which will be described later. This program is stored in an external storage or supplied from an external device. Host 201
Is connected to the recording device 202 via an interface, and transmits the image data that has been subjected to color processing to the recording device 202 for recording.

FIG. 6 is a block diagram for explaining the above image processing. In the present embodiment, the connection process is multivalued (8 bits).
There are two possible methods, one for performing in (1) and the other for performing in binary (1 bit). In case of multi-value (8bit),
FIG. 6A shows the 8-bit processing of the connecting portion. In the case of binary (1 bit) processing, the connection 1 bit processing is performed as shown in FIG.
It shows in (b). In the two diagrams, the block configurations other than the connection processing unit show the same processing content.

Input R, G, B colors 8 bits (25
The 6-gradation image data is output as 1-bit data for each color of C, M, Y, and K through the series of flows shown here.

First, the 8-bit data for each color of R, G, B is
R ′, G ′, B ′ are processed by a color space conversion process (pre-stage color process) 61 which is a three-dimensional lookup table (LUT).
Converted to 8-bit data for each color. This process is a conversion process for correcting the difference between the color space of the input image (color space) and the reproduced color space of the output device.

R ′, G ′, which have been subjected to color space conversion processing,
The 8-bit data of each color B'is converted into 8-bit data of each color of C, M, Y, and K by a color conversion process (post-stage color process) 62 which is the following three-dimensional LUT. This process is a color conversion process for converting the input RGB color to the output CMYK color. The input data is often the three additive primary colors (RGB) of a light emitting body such as a display. However, when expressing colors by reflection of light from a recording device or the like, a color material of the three additive primary colors (CMY) is used. Since it is used, the above conversion process is necessary. Three-dimensional LUT used in the front color processing 61 and three used in the rear color processing 62
The dimension LUT holds data discretely, and the held data is obtained by interpolation processing. Since this interpolation processing is a known technique, detailed description thereof will be omitted here.

The 8-bit data for each color of C, M, Y, and K which has been subjected to the post-stage color processing is output γ processing 63 which is a one-dimensional LUT.
Thus, the output signal is corrected. Normally, the relationship between the number of print dots per unit area and the output characteristics (reflection density, etc.) on the medium is not an ideal linear relationship. Therefore, the output γ process 63 guarantees the linear relationship between the input levels of the C, M, Y, and K8 pits and the output characteristics at that time. As described above, the three processes of the color space conversion process 61, the color conversion process 62, and the output γ process 63 are the correction processes in the color processing unit.

The 8-bit data for each color of C, M, Y and K output from the color processing section is sent to the joint processing section or the quantization processing section. As shown in FIG. 6A, when the data is first sent to the connection processing unit 65, the output data from the color processing unit is set to 8
After the correction in the bit state, the quantization processing unit 64 merges with the data other than the connecting portion and sends 8-bit data. Figure 6 (b)
As described above, when the quantization process is performed first, the 8-bit data from the color processing unit is binarized, and then the correction is performed by the connection processing unit 66 in the 1-bit state.

In the quantization processing section 64, the data of 8 pits for each color of C, M, Y and K is quantized into 1-bit data for each color of C, M, Y and K. In this embodiment, the error diffusion method is used as the quantization method. The error diffusion method is a method capable of smoothly expressing a photographic halftone image with a binary recording device, among many quantizations. For details, since various documents and papers such as “Nikkei Electronics May 1978 issue P50-P65” have been published and are well-known techniques, detailed description thereof will be omitted here.

<Outline of Joint Correction> When the image data output from the color processing unit is sent to the joint processing unit first, only the joint portion is sent to the joint processing unit as 8-bit data as shown in FIG. 6A. . In the case of being sent to the quantization processing unit first, only the quantized connection unit is sent to the connection processing unit as 1-bit data as shown in FIG. 6B. In either case, the connection portion is selected by the CPU 20a, and only the data included in the area already described with reference to FIG. 4 is extracted from the print data. In the case of FIG. 6A, the data that does not correspond to the connecting portion is the quantization processing unit 64.
In the case of (b), it is directly transferred as a binary recording signal.

In the present embodiment, the joining process is realized by thinning out or adding the recording dots in the joining portion to correct. The data sent to the connection processing unit is subjected to correction processing according to the correction table.

FIG. 7 is a correction graph when each color of C, M, Y and K is 8-bit data (in the case of FIG. 6A). The horizontal axis is the 8-bit input value of each of C, M, Y, and K before correction, and the vertical axis is the amount of data reduction, that is, the correction amount. In areas where the input value is low, the dots that are originally recorded are sparse, so the connecting stripes are not very noticeable,
The correction amount is also low. From around the point where the input value exceeds the intermediate density, the overlap of the dots increases and the connecting stripes described in FIG. 1 start to stand out, so the correction amount also gradually increases. Such a correction may be performed for each pixel,
It may be performed by the sum or average of a plurality of pixels, and when processing is performed by a plurality of pixels, the processing may be performed so that the corrected value of each pixel does not become negative. When the sum is used, the range of the horizontal axis and the vertical axis of the correction graph of FIG. 7 may be changed. In addition, the same correction graph may be applied to all the pixels in the connecting portion.
The correction graph to be applied may be changed according to the number of pixels in the sub-scanning direction from the connection shown in FIG. Furthermore, in the above description, C, M, Y, and K single colors have been described, but the correction may be applied to the sum of a plurality of colors or all colors.

FIGS. 8 and 9 are explanatory views of the thinning-out method when each color of C, M, Y and K is 1-bit data (in the case of FIG. 6B). In FIG. 8, the portion shown in black is an area of 1 column × 8 rasters (joint portion). The CPU 20a counts the number of recording pixels in this area. As for the counted value, the thinning-out number (dot reduction number) is determined for each column according to the table shown in FIG. Here, FIG. 9A is a table in the case of independently correcting each color, and the count value is 0 to 8. FIG. 9B is a table in the case of performing correction with the sum of all four colors, and the count value is 0 to 32. Both methods are effective in this embodiment. Such a correction is basically performed for each column, but in practice, it may be performed by taking the sum or average of multiple columns. When processing with multiple columns, recording after thinning each column It suffices to perform processing so that the number of pixels does not become negative. If the average value is not an integer, convert the average value to an integer. Rounding or rounding up or down is used for integerization, but the integerization method is not limited to these. Further, although the correction table in which the thinning-out number is an integer is shown in FIG. 9, it may be other than an integer. However, if the thinning-out number is not an integer, it is converted to an integer. After the thinning-out number is determined, pixels to be thinned out at random from the recording pixels are determined from the recording pixels according to the thinning-out number in the joint portion to which the correction table is applied. The method of determining the pixels to be thinned out from the recording pixels according to the thinning-out number is not limited to random, and may be regularly determined.

In this case, the data corrected by the respective joint processing units is 8-bit data for each color of C, M, Y and K (see FIG. 6).
In the case of (a)), the data is quantized and sent to the recording head.

In the case of 1-pit data for each color of C, M, Y, and K (case of FIG. 6B), the data is sent to the recording head as it is. In either method, the print data after each conversion process has a result that the number of print dots in the connecting portion is smaller than that in other areas.

By the way, in the above two methods, there are some characteristics in the image quality after processing, the constitution of the main body and the processing time. Normally, the color processing units 61 to 63 shown in FIG.
Since the quantization processing unit 64 handles a huge amount of data of 8 bits for each color, it is generally processed by software inside the host computer. Therefore, in the case of FIG. 6A in which the quantization process is performed after the joining process, the joining process is also performed by the host computer. In this method of performing the thinning-out process with 8 bits, since the quantization is performed after the thinning-out process, it is possible to correct the joint portion with a relatively wide field of view, so that the correction is smooth and the image adverse effect is small. However, since the data expansion of the 8-bit processing including the thinning-out processing is all performed by software, the data expansion may take a long time.

On the other hand, in the case of FIG. 6B, the thinning process can be performed on the recording device side with a relatively easy structure. In this case, since 1-bit data processing is developed by the recording device hardware, the processing time is shorter than that in FIG. 6A. However, since the joint portion is corrected with a comparatively narrow visual field of 1 column (several columns) × 8 rasters, the joint portion may be less smooth than that in FIG. 6A.

Either method is effective in the present invention and this embodiment. An appropriate method may be adopted according to the characteristics of the recording apparatus and the conditions of the head.

<Setting method of thinning table> In the above,
The flow of image data when recording with the correction table already determined has been described. Here, a method of setting an optimum correction table for each recording device, each recording head, and each print mode will be described.

FIG. 10 is a flow chart of the mode for setting the correction table. First, when the user selects the correction table setting mode on the UI screen of the printer driver (Step 1), the preset connecting streak pattern is output from the printing apparatus (Step 1).
2).

FIG. 11 shows a connecting line pattern output at this time. Here, a connecting line pattern of one color among C, M, Y and K is recorded.

Here, the numbers 1 to 5 represent the correction level (dot thinning amount) of the connecting portion. The letters A to E represent each recording mode that can be set by the printer driver. The recording mode is for the user to adjust the image quality and the output speed according to the application, and by changing this, the nozzles corresponding to the connecting portion and the paper feed amount are also changed.

All of the patches are set to have a size including a connecting portion. Further, all the patches recorded in the same mode arranged in the horizontal direction are recorded with the same gradation. However, the joint portion is thinned according to each correction level.

FIG. 12 is a graph showing a plurality of correction tables for 8-bit processing, and curves 1 to 5 show correction curves having different levels. in this case,
The patches 1 to 5 in FIG. 11 are recorded according to the correction curves 1 to 5.

FIG. 13 shows a correction table for 1-bit processing, and FIG. 13A shows the case of correction with a single color as shown in FIG.
(B) shows the case where correction is performed with the sum of all four colors. The table contents of the number of thinned dots lined up in the horizontal direction are different according to the correction levels of five stages. In this case, the patches 1 to 5 in FIG. 11 are recorded in accordance with the number of thinned dots.

The user visually confirms the pattern described above, and selects a correction level from 1 to 5 in which the joint portion is the most inconspicuous in each mode. Then, the result is input from the UI screen (Step 3).

In this way, the optimum correction table for each recording mode can be set in the connection processing section of FIG. 6 (Step 4).

As described above, by performing the processing of Step 1 to Step 4 in FIG. 10, the optimum correction table among the plurality of correction tables can be set for each recording apparatus, recording head, and recording mode.

The user can always obtain a smooth output image in which the joint portion is inconspicuous by executing the above-described correction mode when the recording apparatus is loaded or when it is necessary during use.

In FIG. 11, correction of a single color is taken as an example, and all patches are described as having the same color. However, correction for a plurality of colors is actually required. In this case, the patterns for a plurality of colors may be recorded in a line on the same sheet of paper, or may be recorded separately on a plurality of sheets of paper. Further, in the case of correction with mixed colors, a patch in which dots of respective colors are mixed may be used.

Further, in the above, an independent patch is used for each correction level, but the connecting line pattern is not limited to this. This embodiment is effective even if a continuous strip pattern is used and the correction amount is partially changed in the pattern.

Further, although the above description has been made with the correction level set to five stages, the present embodiment is not limited to this. The number of tables may be increased to obtain a more accurate correction table, and conversely may be decreased to simplify the determination. This embodiment is effective if the number of changing stages is at least two or more.

Further, depending on the recording mode, the gradation at which the joint portion is conspicuous may be different. In this case, the patches (A to E) in each recording mode in FIG. 11 do not necessarily have the same gradation. When recording a patch, the input signal on the horizontal axis in FIG.
In 3, the ejection dot count number is different. Each patch may be recorded according to its gradation and correction levels 1-5.

The tables shown in FIGS. 12 and 13 may be different for each color when the correction is performed with a single color.
Further, the present embodiment is effective even if it differs for each recording mode.

Furthermore, the recording apparatus of this embodiment may be compatible with a plurality of types of recording media. Generally, in such a recording apparatus, the recording mode is often different for each recording medium. In this case, in the recording apparatus of this embodiment, an independent correction mode may be executed for each recording medium. When the user sets a recording medium from the UI and mounts the corresponding medium on the recording device, the recording device outputs the connecting stripe pattern in the recording mode of the corresponding medium. If the correction table is selected for each recording medium, the above contents can be realized.

The series of processing shown in FIG. 6 for realizing the present embodiment is performed by the host 201 and the recording device 2 shown in FIG.
02. The present invention proposes a control mode capable of such a series of processing, which is defined as a recording control device and a recording control method.

(Second Embodiment) In the first embodiment, FIG.
In Step 3 of, the user relied on the visual inspection of the user to determine the optimum corrected image. However, since the visual judgment is subjective, the selected correction table is not always appropriate.

On the other hand, in the present embodiment, the recorded connecting line pattern is read by a scanner or a sensor provided in the recording apparatus main body, the level of the connecting line is quantitatively judged from the input signal value, and the optimum correction is made. It sets up a table.

Specifically, after the joining streak pattern is printed by the method of the first embodiment, the same printing sheet is scanned and conveyed again for reading. The scanner or sensor may be provided beside or on the front surface of the carriage or on the recording head to read and scan with the head, or the recording head may be detachable from the carriage to form a cartridge. A replaceable form is also acceptable. Further, the scanner or the sensor may be installed in another place in the main body so that the scanner can read and scan the recording paper only at the time of reading.

In any case, the scanner or sensor scans and scans the paper patch, and stores the read data in the main body or in the memory of the PC. The obtained data is converted into density data and subjected to a process for detecting a joint portion. For patches with constant tone, the densities within the patch should also be uniform. However, here
If there is a connecting line described in, the density is high or low only in that part. Therefore, the data is traced in the sub-scanning direction of the patch, and the correction table of the patch having a portion whose density value is clearly different from the others is excluded as insufficient correction. Then, the patch with the smallest difference in the density value is selected, and the correction table corresponding to the selected patch is automatically set in the main body memory or the driver.

In the present embodiment, it is sufficient that the relative density difference within the patch can be discriminated, and the absolute density is not necessary. Therefore, even if the scanner or the sensor used here has relatively low accuracy and is inexpensive, it can be used.

Further, in the above description, the visibility of the connecting stripes is determined by detecting the density difference, but the present embodiment is not limited to this. The quantitative value for the most inconspicuous joint line selection may be an L value (brightness) difference in the sub-scanning direction of the patch, a brightness difference, or a differential value thereof. Furthermore, the spatial frequency component of the patch in the sub-scanning direction may be taken in consideration of the spatial frequency characteristic of the eye, and the amplitude thereof may be used.

In the above two embodiments, the ink jet recording apparatus has been described as an example, but the present invention is not limited to this. The problem of the connection stripe is not limited to the ink jet recording method, but is a problem that is present to some extent in the serial type recording apparatus. In addition, the method of the present invention of adjusting the density of the connecting portion by increasing or decreasing the number of recording pixels is
Any type of recording device can be used as long as it is a serial scan type recording device.

[0068]

As described above, according to the present invention,
From multiple patterns recorded in multiple correction tables,
Appropriate tables can be set at appropriate times. Also,
In the set table, it is possible to adjust the number of print dots in the connecting portion between the respective print scans and adjust the density of the connecting portion to that other than the connecting portion. Therefore, it is possible to provide a recording control apparatus and a recording control method that can always obtain a uniform image without a connection stripe regardless of individual differences of the recording apparatus, the recording head, and the like.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the permeation of ink ejected from a recording head on a paper surface.

FIG. 2 is a perspective view of a recording apparatus used in the embodiment of the present invention.

FIG. 3 is a block diagram illustrating a control logic of the recording apparatus used in the embodiment of the present invention.

FIG. 4 is a diagram illustrating a connecting portion.

FIG. 5 is a block diagram illustrating an image processing system according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram illustrating a flow of image processing according to the embodiment of the present invention.

FIG. 7 is a relationship diagram showing a relationship between an uncorrected 8-bit value and a correction amount in a joint portion of the recording apparatus according to the embodiment of the present invention.

FIG. 8 is a diagram illustrating a dot count area in a connecting portion.

FIG. 9 is a diagram showing a relationship between a dot count value and a number of dots to be corrected in a connecting portion.

FIG. 10 is a flowchart showing a procedure for setting an optimum correction table according to the embodiment of the present invention.

FIG. 11 is a connecting line pattern for setting the optimum correction table according to the embodiment of the present invention.

FIG. 12 is a plurality of correction curves included in the recording apparatus according to the embodiment of the present invention.

FIG. 13 is a plurality of correction tables included in the recording apparatus according to the embodiment of the present invention.

[Explanation of symbols]

1 recording medium 2 Recovery unit 3 First transport roller 4 Second transport roller 5a-d recording head 6 carriage 7 belt 8a-b pulley 9 Guide shaft 20 Control unit 20a CPU 20b ROM 20c RAM 21 Interface 22 Operation panel 23 Carriage Motor 24 Paper feed motor 25 First Conveyor Roller Drive Motor 26 Second Transport Roller Drive Motor 27 Motor driver 28 Recording head drive driver 29 External device 201 host 202 recording device 61 Color space conversion processing 62 color conversion process 63 Output γ processing 64 Binarization processing 65 Thinning processing 66 Thinning processing

Claims (10)

[Claims] 1. A main scan for performing recording while moving a recording head in which a plurality of recording elements are arranged in parallel in a direction different from a direction in which the recording elements are arranged in parallel, and a relative direction with respect to the recording head in a direction different from the main scanning. In the recording control device for recording an image on the recording medium by repeating the sub-scan for transporting the recording medium, the width including a boundary connected by two main scans and having a predetermined number of consecutive pixels in the sub-scanning direction. Based on pattern data corrected by each of the plurality of correction tables, and an extraction unit that extracts a region having a A plurality of test pattern recording means for recording a plurality of test patterns; and the multi-stage correction table determined from the recorded test patterns. One of anda setting means for setting, the recording control apparatus and recording an image according to the correction table set by said setting means. 2. The recording control apparatus according to claim 1, wherein the plurality of correction tables convert a multi-valued signal into a signal value. 3. The recording control apparatus according to claim 1, wherein the plurality of correction tables convert binary signals into signal values. 4. The recording control apparatus according to claim 1, wherein the correction table set by the setting unit is visually determined from the recorded test pattern. 5. The recording control according to claim 1, wherein the correction table set by the setting unit is determined from a signal value input by an optical device from the recorded test pattern. apparatus. 6. The recording apparatus according to claim 1, wherein the recording apparatus has a plurality of recording modes, and the test pattern recording unit records the test pattern for each of the plurality of recording modes. The recording control device described in 1. 7. The recording apparatus according to claim 1, wherein the recording apparatus has a plurality of recording modes, and the plurality of correction tables are provided for each of the plurality of recording modes. Recording controller. 8. The recording control device according to claim 1, wherein the recording device uses a plurality of the recording heads, and the correction table can be set for each of the recording heads. 9. The recording control apparatus according to claim 1, wherein the recording head is of an ink jet type that ejects ink from a plurality of nozzles to perform recording on the recording medium. 10. A main scan in which a plurality of print elements are arranged in parallel and printing is performed while moving the print head in a direction different from the direction in which the print elements are arranged in parallel, and relative to the print head in a direction different from the main scan. In the recording control method of recording an image on the recording medium by repeating the sub-scan for transporting the recording medium, the width including a boundary connected by two main scans and having a predetermined number of consecutive pixels in the sub-scanning direction. The area having a is extracted as a connecting area, a plurality of correction tables for performing correction for increasing or decreasing the number of recording pixels in the connecting area are prepared, and according to each of the plurality of correction tables, a plurality of test patterns are recorded, Setting one of the plurality of correction tables determined from the recorded test pattern and recording an image according to the set correction table Recording control method according to claim.