JP2002011861A - Information processing system, ink-jet recording device, and image data correcting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record a high quality image by reducing generation of black stripes as density irregularity at a joint part between recording areas formed in each scanning of a recording head in an ink-jet recording device. SOLUTION: An ink amount 13-9 to be possibly provided to the joint parts of recording data 13-1, 13-2, 13-3, 13-4 of three rasters at joint parts adjacent to the recording area in the scanning operation of immediately before, is calculated based on the gradient value for each pixel thereof for each image data to be supplied to a recording head of each color ink. According to the ink amount, a thinning operation is executed with reference to a thinning table for finding the final recording data at the joint parts 13-10, 13-11, 13-12, 13-13. Thereby, the ejected ink amount at the joint parts in the vicinity of the boundaries can be reduced so that black stripes can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus, an ink jet recording apparatus and an image data correcting method.
More specifically, the present invention relates to an information processing apparatus, an inkjet recording apparatus, and an image data correction method capable of reducing density unevenness generated at or near a boundary of a recording area formed in response to scanning of a recording head.

[0002] The present invention can be applied to all apparatuses that perform recording by an ink-jet method using a recording medium such as paper, cloth, nonwoven fabric, OHP paper, etc. Specifically, such apparatuses include printers, copiers, and the like. Examples include office equipment such as facsimile machines and mass production equipment such as printing machines.

[0003]

2. Description of the Related Art Conventionally, paper, cloth, plastic sheet, O
2. Description of the Related Art An ink jet recording apparatus capable of performing recording on a recording medium such as an HP sheet is often used as an information output apparatus in an information processing apparatus because it can perform high-density and high-speed recording. For example, it is used as a recording unit of a copying machine, a facsimile, an electronic typewriter, a word processor, a workstation, or the like, or as a printer for outputting information processed by a personal computer or a host computer connected via a network. Further, it is also used as a handy or portable printer provided in an optical disk device, a video device, and the like, and has been commercialized.

In this case, the ink jet recording apparatus, of course, has a configuration corresponding to the functions and usage forms specific to the used apparatuses, but the ink jet recording apparatus generally includes a recording head or a recording head and an ink tank. And a transport mechanism for transporting recording paper as a recording medium, and a control circuit for controlling these. Then, the recording head mounted on the carriage is caused to scan (hereinafter, also referred to as “scan”) the recording paper in a direction (hereinafter, also referred to as “main scanning direction”) orthogonal to the transport direction (hereinafter, also referred to as “sub-scanning direction”). During this scanning, the recording paper is conveyed according to the recording width in the scanning of the recording head, thereby sequentially recording on the recording paper.

According to this method, recording is performed by discharging ink from a nozzle of a recording head onto recording paper in accordance with a recording signal based on image data. Therefore, the running cost is low and the recording cost is reduced. Noise is also widely used as a relatively small recording method. In addition, by using a print head having a large number of nozzles arranged in the sub-scanning direction, the print width of a print area that can be printed by one scan can be increased, thereby achieving high-speed printing. More recently, an apparatus has been provided which is capable of performing full-color printing by mounting such a printing head for inks of three to four colors. Such an ink jet recording apparatus generally includes a recording head and an ink tank respectively corresponding to three primary colors of yellow (Y), magenta (M), and cyan (C) or four colors including black (Bk). It is provided.

An ink jet recording apparatus having such a configuration requires a certain degree of accuracy in ejecting ink from nozzles in a recording head or a paper feed amount performed in accordance with scanning of the recording head. That is, variations in the discharge amount and discharge direction of the print head appear as density unevenness in the print image, and variations in the paper feed amount cause black stripes at the boundary between print regions for each scan and at a joint portion near the boundary. And uneven density such as white stripes may occur.

[0007] It is difficult to completely eliminate these factors at the stage of manufacturing a recording head or an apparatus. Particularly, as the required image quality increases, the difficulty only increases. From this point, there has been proposed a recording method which does not completely eliminate the cause of the density unevenness, but makes the density inconspicuous even if there is some density unevenness.

Further, the number of occasions of recording on various recording media having different characteristics, such as plain paper, coated paper, and OHP paper, has increased, and a recording method suitable for each recording medium with respect to density unevenness has been required. I have. For example, in a recording medium, such as coated paper or plain paper, in which ink is absorbed relatively quickly, a connecting streak, which is one of the density unevenness, often appears as a black streak. As a particularly remarkable case, a black streak generated at a connection portion between recording regions caused by scanning of the recording head is raised. This can be explained as follows.

FIG. 1 schematically shows a cross section in the thickness direction of the recording paper in the state of ink on the recording paper when recording is performed by two scans of the recording head, and is realized by the state. It shows the optical reflection density. The ink ejected in the preceding scan is denoted by the symbol A on the paper.
And indicates the concentration due to the penetration. After the recording paper is conveyed according to the recording width, the ink discharged in the subsequent scanning penetrates as shown in B in the figure. At this time, in a portion adjacent to the permeation region A, the permeation in a state of being attracted toward the permeation region A occurs, and a portion like the region C is generated. This is a state in which the ink that has been ejected in the preceding scan and has penetrated the recording paper has increased the penetrating power to the recording paper, and as a result, the ink in the next scan is drawn by the penetrated ink in the preceding scan. It is thought that it will be in a state. Due to such a bias of ink penetration, the density of the connecting portion becomes high, and black stripes are generated. The above description relates to a method of performing printing by performing only one scan on each print area.

In order to solve the above-mentioned density unevenness, for example, Japanese Patent Application Laid-Open No. 5-220977 discloses a method of controlling density unevenness for each raster (data) of image data corresponding to each nozzle of a print head during printing. A so-called head shading method has been proposed in which density unevenness is reduced by performing correction.

Further, the applicant of the present application has proposed that a recording head supplied to a recording head to record at least one of a plurality of connection regions which are predetermined regions adjacent to boundaries between recording regions by scanning. There has been proposed a method of calculating the total signal value and correcting the magnitude of the recording signal value for recording the connection area according to the magnitude of the total recording signal value.

[0012]

However, although the above-described structure can reduce the density unevenness generated in the connection region, there is a problem in mounting.

That is, when the ink jet recording apparatus is used by being connected to a host computer including a system configured via a network, processing with a large load such as image processing such as color processing of image data is performed by the host computer. The image data is in the form of image data in a form directly representing whether or not ink is to be ejected by the recording head of the recording apparatus by this processing, and is often sent to the recording apparatus as image data in a binary form. ing. On the other hand, on the recording apparatus side, for example, JP-A-8-207
As disclosed in Japanese Patent Application Publication No. 399, there is a case where a special recording head movement or conveyance of a recording medium is performed, such as performing recording while skipping a blank portion of image data in order to increase the recording speed. For this reason, when the host computer finally creates binary image data by image processing, the print head or the print head in the printing apparatus is used to determine a joint between print areas formed by scanning the print head in advance. The operation of the recording medium must be considered,
There is a problem that the processing speed is reduced by the processing. On the other hand, it is considered that the recording device corrects a joint between the recording areas. However, since the binarized image data sent from the host computer has a small amount of information on density unevenness, an accurate correction amount is required. There is a problem that it is relatively difficult to calculate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems.
It is an object of the present invention to provide an information processing apparatus, an inkjet recording apparatus, and an image data correction method that can reduce occurrence of a streak due to recording scan and record a high-quality image.

[0015]

According to the present invention, there is provided:
In an information processing system including a host device and an ink jet recording device that performs recording based on recording data sent from the host device, a boundary of each of a plurality of recording areas formed at the time of a recording operation in the ink jet recording device An ink amount data generating means for obtaining, in the host device, data on an ink amount that can be ejected into the predetermined portion based on image data of a nearby predetermined portion, and an ink amount data obtained by the ink amount data generating device. Data output means for sending to the ink jet recording apparatus together with the recording data based on the image data, and thinning out the recording data of the predetermined portion based on the ink amount data sent from the host device by the data output means, the ink jet recording apparatus Means of thinning out , Characterized by having a.

According to another aspect, in an ink jet recording apparatus which performs recording based on recording data transmitted from a host apparatus, the data transmitted from the host apparatus together with recording data based on image data, Receiving means for receiving data of an ink amount that can be ejected into the predetermined portion, which is obtained based on image data of a predetermined portion near the boundary for each of the plurality of recording areas to be formed, and an ink amount received by the receiving means Thinning means for thinning out the recording data of the predetermined portion based on data.

According to still another aspect, in an image data correction method for correcting image data used in an ink jet printing apparatus for printing based on print data, a plurality of printing areas formed at the time of printing operation in the ink jet printing apparatus are provided. Is obtained based on image data of a predetermined portion in the vicinity of the boundary, data of an ink amount that can be applied to the predetermined portion is obtained, and print data of the predetermined portion is thinned out based on the ink amount data to generate print data. , Steps.

According to the above arrangement, for each of a plurality of recording areas formed at the time of recording operation in the ink jet recording apparatus, based on the image data of the prescribed portion near the boundary, data of the amount of ink that can be injected into the prescribed portion. Is determined, and the recording data is created by thinning out the recording data of the predetermined portion based on the ink amount data. Therefore, the predetermined portion near the boundary adjacent to another recording region in each recording region, that is, the connecting portion is used. During recording, the amount of ink that is ejected there can be reduced, thereby reducing black streaks, which are uneven density on the streaks generated at the joints.

[0019]

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

(Embodiment 1) A first embodiment of the present invention will be described with reference to FIGS.

<Overview of Recording Apparatus> FIG. 2 is a perspective explanatory view showing a schematic configuration of an ink jet recording apparatus according to the present embodiment.

In FIG. 2, reference numeral 1 denotes a recording sheet as a recording medium made of paper or a plastic sheet;
A plurality of sheets 1 stacked on a cassette or the like (not shown) are supplied one by one by a paper feed roller (not shown). The fed recording sheet 1 is arranged in a direction indicated by an arrow A in the figure by a first transport roller pair 3 and a second transport roller pair 4 which are arranged at a predetermined interval and are driven by respective stepping motors (not shown). Transported to

The recording heads 5 prepared for the respective inks of C, M, Y and Bk are removably mounted on the carriage 6 for each of the recording heads. A predetermined number, for example, 256 ink ejection ports (nozzles) are arranged in the scanning direction). The ink used in each recording head 5 is similarly supplied from a corresponding ink cartridge (not shown) mounted on the carriage 6, so that ink can be ejected from each nozzle according to a recording signal. Each recording head has an electrothermal conversion element in an ink path corresponding to each nozzle, and the electrothermal conversion element generates bubbles in the ink using thermal energy generated by application of an electric pulse corresponding to a recording signal. The ink is ejected by the generation pressure of the bubbles. A part of the belt 7 is joined to the carriage 6, whereby the driving force of the carriage motor 23 is transmitted via the belt and the pulleys 8a and 8b, and the carriage 6 can be moved. On the other hand, the carriage 6 is configured to slidably engage with the guide shaft 9 and to reciprocate along the guide shaft 9. With the above-described carriage configuration, scanning for recording, in which recording is performed by ejecting ink onto the recording sheet 1 in accordance with a recording signal while the recording head 5 moves in the direction of arrow B in the drawing, becomes possible.

The recording head 5 moves to the home position as required, and performs a predetermined recovery operation by the discharge recovery device 2. For example, the cap of the recovery device 2 covers the surface of each recording head where the nozzles are provided, and forcibly discharges ink from inside the nozzles, preliminary recovery that performs suction recovery and discharge that does not involve recording from each nozzle of the recording head, and the like. Can be performed. This recovery operation makes it possible to eliminate clogging or the like caused by the thickened ink that may have occurred in each nozzle.

In the above arrangement, the recording head 5 and the conveyance of the recording sheet 1 by an amount corresponding to the width of the recording area to be recorded by the scanning are repeated to record on the recording sheet 1 according to the image data. It can be carried out.

FIG. 3 is a block diagram showing the configuration of a control system in the ink jet recording apparatus.

As shown in FIG. 3, the control system of this embodiment is as follows.
For example, CPU 20a such as a microprocessor, CPU 2
ROM2 for storing the control program of Oa and various data
0b, a control system 20 having a RAM 20c for temporarily storing various data such as image data and the like, which is used as a work area of the CPU 20a, an interface 21, an operation panel 22, and each motor (a motor 23 for driving a carriage). , A motor 27 for driving the paper feed roller, a motor 25 for driving the first conveyor roller pair, a driver 27 for driving the second motor for driving the conveyor roller pair, and a print head driving driver 28. I have.

The control unit 20 receives various information (for example, character pitch and character type) from the operation panel 22 and I / O such as image data with an external device 29 which is a host device such as a personal computer via an interface 21. O
(Input and output of information). The control unit 20 outputs ON and OFF signals for driving the motors 23 to 26 via the interface 21, and outputs various control signals and recording signals for each head to the head driver 28. Then, the ink ejection according to the scanning of each recording head is controlled.

When outputting the image data, the control unit 20 determines whether or not the image data is a connection portion, as described later. The image data according to the image data from the host computer is sent to the recording head.

<Outline of Image Processing> FIG. 4 is a block diagram showing an information processing system configured as one embodiment of the present invention. That is, the information processing system according to the present embodiment includes the ink jet printing apparatus (hereinafter, also simply referred to as “printing apparatus”) 200 of the present embodiment described with reference to FIGS. 2 and 3 and a host computer (hereinafter, simply referred to as “host”) which is an external device. 201) so that bidirectional communication is possible.

As shown in FIG. 4, the host 201
It comprises a PU 202, a memory 204, an external storage device 203, an input unit 205, and an interface 206 between the inkjet recording device 200.
The CPU 202 can execute color processing, quantization processing, and the like, which will be described later, by executing a program stored in the memory 204. These programs are stored in the external storage device 203 or supplied from an external device. The host 201 having the above configuration is connected to the recording device 202 via the interface 206.
The image data subjected to the image processing and other control data can be transmitted to the recording device 202 for recording.

FIG. 5 is a block diagram for explaining the image processing performed at 201.

This image processing includes data read by a scanner (not shown) and image data processed by the host 201, and includes R (red), G (green), and B (blue) colors.
This is performed on image data of bits (256 gradations), and can be used as it is in the printing apparatus 200. C (cyan), M (magenta), Y (yellow), and K (black) 1 This is a process of outputting as bit data. First, the 8-bit data of each color of R, G, and B is 3 bits.
Each color is converted into 8-bit data R ', G', B 'by a dimensional lookup table (LUT). This processing is called a color space conversion processing (pre-stage color processing), and is a conversion processing for correcting a difference between a color space formed by input image data (color space) and a color space that can be realized by a printing apparatus as an output apparatus. . The 8-bit data R ', G', B 'for each color which has been subjected to the color space conversion processing is converted into 8-bit data for each color of C, M, Y, K by a three-dimensional LUT at the next stage. This processing is called color conversion processing (second-stage color processing), and is performed by input system R
This is a color conversion process for converting a GB color to an output CMYK color. That is, the input data is the three primary colors R, G, and B of the additive color mixture, which are signals of a luminous body such as a display.
However, when a color is expressed by reflection of light in a recording apparatus or the like, the conversion processing is performed because the three primary colors C, M, and Y of the subtractive color mixture are used.

The three-dimensional LUT used for the first-stage color processing and the three-dimensional LUT used for the second-stage color processing do not hold corresponding data for all input data, but hold data discretely. If the input data does not correspond to the held data, the output data is obtained by interpolation processing. Such an interpolation processing is a known technique, and a detailed description thereof will be omitted.

The 8-bit data C, M, Y, and K for each color that has been subjected to the post-stage color processing are subjected to output γ correction by a one-dimensional LUT. In many cases, the relationship between the number of dots formed per unit area during recording and the reflection density achieved thereby does not have a linear relationship. Therefore, by performing the output γ correction, the linear relationship between the gradation level of the input image data represented by the C, M, Y, and K 8-bit data and the gradation level of the output is guaranteed.

The 8-bit image data C, M, Y, K of each color obtained by the above-described processing of the color processing unit is converted into binary data in a form used directly by the recording device in the quantization unit, and described later. Is provided for the processing of creating ink amount data for the connection portion processing. That is, since the color printing apparatus of this embodiment is a binary printing apparatus,
8-bit image data for each color of M, Y, K is C, M, Y, K
Each color is quantized into 1-bit image data. The image data of 8 bits for each color is used in the calculation of the amount of ink to be ejected to the connecting portion of the recording area in the connecting portion processing described later with reference to FIGS. 6 to 9, and the obtained ink amount data is The data is sent to the recording device together with the 1-bit image data.

In the present embodiment, quantization is performed by an error diffusion method that allows a photographic halftone image to be smoothly expressed by a binary recording device. That is, the above-described 8-bit data of each color of C, M, Y, and K is quantized into 1-bit image data of each color of C, M, Y, and K by the error diffusion method. For details of the quantization method using the error diffusion method, see, for example, “Nikkei Electronics May 1978, P50 to P6.
Since various documents and papers have already been published including “5” and are known technologies, detailed descriptions thereof will be omitted.

The composition of the ink used in this embodiment is shown below.

(Black (Bk) ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight IJA260 (10% aqueous solution) 10.0 parts by weight Project Fast Black 2 (5% aqueous solution) 36.5 parts by weight Isopropyl alcohol 2.0 parts by weight Ammonium sulfate 1.0 part by weight Na @ H 1.0 part by weight Acetylenol EH 1.0 part by weight Water remaining part

(Yellow (Y) ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight Project Fast Yellow 2 (4.3% aqueous solution) 43.48 parts by weight Daiwa Yellow 330EP 0 0.5 parts by weight Isopropyl alcohol 2.0 parts by weight Ammonium sulfate 1.0 part by weight 4N-Li @ H 1.0 part by weight Acetylenol EH 1.2 parts by weight Water balance

(Magenta (M) ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight Project Fast Magenta 2 (4% aqueous solution) 45.0 parts by weight isopropyl alcohol 3.0 parts by weight Part Ammonium sulfate 1.0 part by weight 10% Li @ Ac 1.0 part by weight Acetylenol EH 1.0 part by weight Water balance

(Cyan (C) ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight Direct Blue 199 (10% aqueous solution) 28.0 parts by weight Isopropyl alcohol 2.0 parts by weight Ammonium sulfate 1.0 part by weight 10% Li @ c 1.0 part by weight Acetylenol EH 1.0 part by weight Water balance

The details of the connecting portion processing for correcting the image data of the connecting portion performed in the information processing system described above will be described below.

<Connection Process> FIG. 6 is a diagram for explaining the connection process of the present embodiment. As described above, the image data processed by the color processing unit of the host 201 is further processed by the quantization unit and the ink amount calculation unit. Ink amount data calculated by the ink amount producing unit, specifically, 4-bit data obtained by calculating the sum of gradation values represented by 8 bits for each of C, M, Y, and K data and calculating according to a formula described later Are transferred to the interface 206 together with C, M, Y, K and 1-bit image data (hereinafter also referred to as print data), and are input to the interface of the printing apparatus at a predetermined timing.

In the printing apparatus, for print data for one scan, first, print data sent as data corresponding to pixels in the main scanning direction is rearranged into pixel data along the nozzle row array direction in the print head. Perform conversion processing. Thereafter, it is determined whether or not the recording data is for the connection portion, that is, whether or not the recording data is to be corrected for the connection portion. Specifically, three rasters adjacent to those boundaries in a print area by each scan are connected, and correction is performed on the print data.

When these rasters correspond to the nozzles of the recording head, as shown in FIG. 7, the raster at the connecting portion is the uppermost nozzle 1 of the recording head and the nozzles 2 following it.
And 3. It should be noted that the raster forming the connecting portion is not necessarily recorded only by these nozzles. That is, in a so-called multi-pass printing method in which one raster is printed by a plurality of different nozzles, nozzles other than the above-described nozzles are also supported.

Further, the raster forming the connecting portion is affected by the characteristics of the recording medium and the characteristics of the ink. In a special recording medium with improved recording characteristics, a layer that absorbs ink is provided, so that the phenomenon of ink flowing in due to the above-described drawing related to ink penetration is reduced. For this reason, it is possible to reduce the number of rasters that need to be considered as the connecting portion. On the other hand, in a medium generally used in electrophotography or the like, the ink absorption layer is smaller than the amount of ink, so that the ink penetrates in a direction other than the depth direction of the medium. As a raster needs to be more. Similarly, it is desirable to make the number of rasters to be considered as a link part different depending on the difference in ink permeability.

If it is determined in the above connection portion that the connection portion is not a connection portion, print data of 1 bit for each of C, M, Y, and K is sent to a print head driver. on the other hand,
If it is a joint, correction is performed by thinning out print data. This makes it possible to reduce the amount of ink ejected to the connection portion and reduce black streaks that are uneven in density that occur in or near the recording area.

In this thinning-out process, first, when the 1-bit data of the recording data of each pixel in the connection portion is turned on, that is, indicating that ink is to be ejected, the 4-bit ink amount data corresponding to the pixel is used. FIG.
Referring to the thinning table shown in (a), the probability of thinning is obtained, and the thinning of the recording data is performed according to this probability.
As shown in FIG. 8A, in the present embodiment, the probability is determined according to the value of 0 to 15 of the ink amount data, and the probability is made different for each raster. In other words, the probability is set so that the closer to the boundary of the recording area, the higher the probability of the same ink amount data value.

The more detailed aspects of the thinning-out probability and the thinning-out method based on the thinning-out probability in the present embodiment are as follows.

The probability of thinning set in the above-described table is to record a raster area in a certain range, and to realize the thinning amount in which density unevenness appearing at a joint is most inconspicuous. For example, in a case where recording is performed with a duty of discharging ink to all pixels constituting the raster area using a patch of a predetermined size using only the cyan ink and the raster area, the thinning probability corresponding to the calculated ink amount is When all pixels of the first raster from the joint are thinned out and thinning is performed at a rate of one pixel out of five pixels of the second raster, uneven stripes at the most joint become inconspicuous. That is, thinning is
By setting the 100% thinning probability for the first raster from the joint, the 20% thinning probability for the second raster, and the 0% thinning probability for the third raster,
Streak unevenness that may occur at a joint can be reduced most effectively.

The table shown in FIG. 8A set in this way is referred to by the calculated ink amount, and based on the probability obtained based on the calculated amount, whether or not to thin out the recording data for each pixel is determined. Is determined.
Specifically, the following procedure is performed.

I) As described above, the probability of horseback (1 to 100) is determined for the pixel to be processed with reference to the table, and multiplied by ten.

Ii) Next, a numerical value is obtained from a random function circuit that randomly generates a numerical value of 0 to 1000.

Iii) The numerical value obtained in i) is compared with the numerical value obtained in ii). If the numerical value obtained in i) is equal to or larger than the numerical value obtained in ii), the recording data of the pixel is thinned out. If the numerical value obtained in i) is smaller than the other numerical values obtained in ii), the pixel is not thinned out.

With the above procedure, it is possible to execute the thinning of the probability obtained from the table.

The image data that has been subjected to the thinning process in this way is sent to the printhead as print data for the connection portion. Although this process is performed for each print head, in this embodiment, thinning is performed on four types of print data C, M, Y, and K using the same thinning table shown in FIG. Do.

FIG. 9 is a diagram specifically showing the above-described correction processing in accordance with the flow of print data.

In FIG. 9, each grid represents one pixel.
FIG. 3 shows three rasters at the connection portion of the print data for one scan, and only three pixels in the main scanning direction are shown for simplification of the description.

As described above, first, the recording data for one scan of 8 bits each of C, M, Y, and K which has been subjected to color processing by the host computer 201 is represented by reference numerals 13-1 to 13-4. It is. These print data are data represented by any one of gradation values of 0 to 255. For each pixel, the sum of the gradation values of C, M, Y, and K is calculated, and 4-bit ink amount data is calculated. And The formula for calculating the ink amount data is represented by the following formula.

Ink = (C + M + Y + K) / 32 However, the calculation result is rounded to an integer value, and otherwise is set to 15.

The ink amount data calculated in this manner is indicated by reference numeral 13-9 in FIG. As mentioned above,
The ink amount data and the binary print data are sent to the printing apparatus via the interface. Note that, in addition to these data, control data related to paper feeding is also sent to the recording apparatus.

As described above, in this embodiment, the ink amount data is calculated corresponding to all the pixels to be printed. However, in the thinning process in the printing apparatus using the data, the data of the predetermined pixel close to the seam is used. Use only. For this reason, the ink amount data other than those of the predetermined pixels is wasted, and the processing for the calculation is redundant. However, there is an advantage that it is not necessary for the host computer to consider which pixel is a pixel constituting the connection portion.

That is, when the host computer determines which pixel constitutes the connecting portion,
For example, when the printing apparatus independently optimizes the printing scan, relatively complicated processing is required. The printing apparatus of the present embodiment independently performs complicated printing scan optimization processing. For this reason, the host computer determines the optimization processing in advance, and determines a connection portion based on the optimization processing. Calculating the thinning amount in such a manner complicates the processing. For this reason, in this embodiment, although redundant processing is performed, the calculation of the ink amount described by realizing only with addition and shift operations is basically performed for all the pixels,
This realizes faster processing.

Of course, when the host computer transmits print data in consideration of the printing scan of the printing apparatus, or when the host computer calculates the optimization of the print scan in advance for faster processing, the printing resolution becomes higher and the pixel resolution becomes higher. For example, when it is desired to reduce the amount of print data, a link portion for print scan may be calculated in the host computer in advance, and the ink amount may be calculated only for the pixel and transmitted to the printing apparatus.

The printing apparatus receives these data and determines whether or not it is a connection portion as described above. For the connection portion, the printing data of each pixel is referred to by referring to the thinning table based on the ink amount. Determine the probability of thinning out. In the example shown in FIG. 9, the ink amount data of the first raster in the ink amount data 13-9 is 11, 12, 10
Therefore, the probability of thinning obtained by referring to the thinning table shown in FIG. 8A is 100%, so that the print data of these pixels is necessarily thinned. On the other hand, for example, when the thinning-out probability obtained by referring to the table is 75%, for example, this 75%
If there are four pixels with the probability of, three of them will be thinned out. The recording data obtained as a result of the thinning process performed as described above is denoted by reference numerals 13-10 to 13 in FIG.
13-13.

By the above-described thinning-out processing, it is possible to reduce streak-like density unevenness which may occur at a joint of recording areas by each scan.

(Modification of Embodiment 1) In this modification, in Embodiment 1 described above, both the calculation of the ink amount and the thinning-out table perform the same calculation regardless of the type (color) of the ink. It used a thinning table. However, as described above, the stripe-shaped density unevenness that occurs at the joint of the printing areas due to each scan is caused by the penetration of the ink into the printing medium. Therefore, the permeability to the printing medium depends on the type of the ink. May be significantly different. In such a case, it can be considered that the thinning-out table is made different for each type of ink to cope with this. However, in consideration of the fact that the stripe-shaped density unevenness occurring at the joint occurs depending on the total ejection amount of all types of ink to be ejected there, a thinning-out table is set for each type of ink and thinning is performed. Proper correction may not be performed simply by determining the probability.

Therefore, in the present modified example, when calculating the ink amount of the joint portion, the ink amount is calculated by performing weighting for each type of ink (penetration). Also, with this,
A thinning-out table is also set for each type of ink.

The composition of the ink used in this embodiment is shown below.

(Black ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight IJA260 (10% aqueous solution) 10.0 parts by weight Project Fast Black 2 (5% aqueous solution) 36.5 Parts by weight Daiwa Yellow 330EP 0.3 parts by weight Direct Blue 199 (10% aqueous solution) 7.2 parts by weight Isopropyl alcohol 2.0 parts by weight Ammonium sulfate 1.0 part by weight Na @ H 1.0 part by weight Acetylenol EH 1.0 part by weight Water Rest

(Yellow ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight Acid Yellow 23 (5% aqueous solution) 60.0 parts by weight Daiwa Yellow 330EP 0.5 parts by weight Isopropyl alcohol 2.0 parts by weight Ammonium sulfate 1.0 part by weight 4N-Li @ H 1.0 part by weight Acetylenol EH 1.0 part by weight Water balance

(Magenta ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight Project Fast Magenta (4% aqueous solution) 45.0 parts by weight Isopropyl alcohol 3.0 parts by weight Ammonium sulfate 1. 0 parts by weight 10% Li @ Ac 1.0 parts by weight Acetylenol EH 1.0 parts by weight Water balance

(Cyan ink) Glycerin 7.5 parts by weight Thiodiglycol 7.5 parts by weight Urea 7.5 parts by weight Direct Blue 199 (10% aqueous solution) 28.0 parts by weight Isopropyl alcohol 2.0 parts by weight Ammonium sulfate 1. 0 parts by weight 10% LiAc 1.0 parts by weight Acetylenol EH l. 0 parts by weight water balance

The formula for calculating the amount of ink used in this embodiment is represented by the following formula. ink = (C + M + Y × 0.8 + K) / 32 Further, the thinning-out tables are shown in FIGS. 8B and 8C, respectively. That is, the table shown in FIG. 4B is used for cyan, magenta, and black inks, and the table shown in FIG. 5C is used for yellow ink.

As described above, the weighting of the yellow ink in the calculation of the amount of the ink and the difference in the thinning-out table are different from those of the other inks because the permeability is lower than that of the other color inks. There is little effect on the occurrence of uneven density at the joint. For this reason, weighting smaller than 1 is performed so as to make a small contribution to the calculated ink amount. Further, as shown in FIG. To be smaller.

As described above, by making the ratio of the contribution to the calculated ink amount different from the actual ink amount and changing the thinning amount according to the type of ink,
For various inks having different characteristics, it is possible to reduce streak-like density unevenness at a joint between recording areas by scanning.

As another embodiment, when a recording head capable of modulating the amount of ink ejected from one nozzle is used, the ink amount at the connecting portion may be corrected using this characteristic.

(Embodiment 2) In another embodiment of the present invention, the method of thinning out at the connecting portion is different from that of Embodiment 1 and its modifications. In the present embodiment, as shown in FIGS. 10 and 11, the calculation of the ink amount of the connection portion is performed with the 8-bit data as it is, and the ink amount data obtained in the 8-bit form is converted into the three rasters of the connection portion.
(3 planes) are binarized and sent to the recording device together with the binary recording data. That is, the host 201
In step (2), binary ink amount data is obtained in the same manner as binary print data, and these are sent to the printing apparatus 200. This allows
It is possible to simplify the data format when sending data relating to two types of recording.

For the transferred data, the printing apparatus performs a process of obtaining the logical product of the binary ink amount data and the print data and thinning out the print data.

FIG. 12 is a diagram for explaining the generation of thinned recording data in the connection portion according to the present embodiment.
FIG. 10 is a view similar to FIG.

In FIG. 12, predetermined image processing is performed on the image data in the host 201 as described above.
8-bit image data 9-1, 9-2, 9-3, and 9-4 are obtained for each of the inks C, M, Y, and K. As in the case of the first embodiment described with reference to FIG. 9, only the connection portion of the image data is shown.

The image data of these connection portions is obtained by summing the gradation values for each pixel to obtain data 9-5. With this data, ink amount data 9-10, 9-11, and 9-12 are obtained for rasters 1, 2, and 3, respectively, according to the table for each raster shown in FIG.

The table shown in FIG. 13 performs a predetermined conversion on the above-described sum of the gradation values for each pixel and regards the result as the ink amount of the pixel. The conversion contents are different for each raster. I have. In other words, the closer the raster is to the boundary of the recording area by each scan of the recording head, that is, the closer to the boundary in the order of rasters 1, 2, and 3 in FIG. Perform the conversion.

The 8-bit ink amount data for each raster obtained by the above-described conversion using the table is binarized by a predetermined binarization method. In this embodiment, the binarization is performed in the same manner as the binarization of the image data. That is, the same processing as that for the image data is performed at the same timing as the binarization processing of the image data, whereby the configuration of the image processing can be simplified. The binarized ink amount data for each raster is data 9-1 in FIG.
3, 9-14 and 9-15.

The binary ink amount data obtained in this way is the logical inverse of the binary ink amount data and the binary print data 9-6, 9-7, 9-8 and 9-9 for each color. Is taken. More specifically, among the ink amount data 9-13, 9-14, and 9-15 of each raster, only the binary data R1, R2, and R3 of the corresponding raster (inverted data of the corresponding raster) correspond to the corresponding raster of each color. Is calculated for each corresponding pixel between the print data and the corresponding print data.

As a result, the final recorded data 9-16, 9-17, 9-18 and 9
-19 is obtained. As described above, the same form as the print data regarding the ink amount of the connection portion in advance (binary in the present embodiment)
Is obtained, and by using this data as mask data, it is possible to thin out the connecting portion. At the same time, in order to obtain finally thinned recording data, the processing can be performed in the same data format as in the case of generating the recording data, and the configuration of the image processing can be simplified.

Note that also in the present embodiment, the first embodiment
The modifications described above and other embodiments can be similarly implemented.

[0089]

As is apparent from the above description, according to the present invention, for each of a plurality of recording areas formed at the time of recording operation in an ink jet recording apparatus, based on image data of a predetermined portion near the boundary thereof, Data of the amount of ink that can be ejected to a predetermined portion is obtained, and the recording data of the predetermined portion is thinned out based on the ink amount data to generate recording data. The above-mentioned predetermined portion, that is, the amount of ink to be ejected thereat when recording the spliced portion can be reduced, whereby the black streak which is uneven density on the streak generated at the spliced portion can be reduced.

As a result, it is possible to record a high-quality image with reduced occurrence of black streaks at the joint.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining density unevenness occurring at a joint portion of a print area for each scan of a print head.

FIG. 2 is a perspective view illustrating a schematic configuration of an inkjet recording apparatus according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a control system of the printing apparatus.

FIG. 4 is a block diagram illustrating a configuration of an information processing system including the recording device and a host computer.

FIG. 5 is a block diagram illustrating a configuration of image processing including ink amount data creation according to an embodiment of the present invention, which is executed by the host computer.

FIG. 6 is a block diagram showing a configuration of a thinning-out process in a connection part of recording areas executed using the ink amount in the information processing system.

FIG. 7 is a diagram showing the correspondence between pixels of a link portion to be subjected to the thinning process and nozzles of a print head.

FIG. 8A shows a thinning table used in the thinning processing according to an embodiment of the present invention, and FIGS.
(c) is a diagram showing a thinning table according to another embodiment.

FIG. 9 is a diagram illustrating a thinning process according to an embodiment of the present invention by using data for each pixel.

FIG. 10 is a block diagram illustrating a configuration of image processing including ink amount data creation according to an embodiment of the present invention, which is executed by a host computer according to another embodiment of the present invention.

FIG. 11 is a block diagram showing a configuration of a thinning-out process at a connection portion of recording areas executed using the ink amount in the information processing system according to the other embodiment.

FIG. 12 is a diagram illustrating a thinning process according to another embodiment by using data for each pixel.

FIG. 13 is a diagram conceptually showing an ink amount table used in a thinning process according to another embodiment.

[Explanation of symbols]

 5 Recording head 6 Carriage 20 Control unit 20a CPU 20b RAM 20c ROM 21 Interface 22 Operation panel 23 Carriage motor 24 Feed motor 25 First transport roller drive motor 26 Second transport roller drive motor 27 Driver 28 Driver 29, 201 External device ( (Host computer) 200 inkjet recording device 202 CPU 203 external storage device 204 memory 205 input unit 206 interface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Daigoro Kanematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masao Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Non-corp. F term (reference) 2C056 EA06 EA08 EA11 EB29 EB45 EC03 EC71 EC75 EC76 ED05 EE03 FA03 FA10 FB02 FB03 2C062 AA37 AA52 KA03 5B021 AA01 BB02

Claims (27)

[Claims] 1. An information processing system comprising a host device and an ink jet recording device that performs recording based on recording data sent from the host device, wherein a plurality of recordings formed during a recording operation in the ink jet recording device. Ink amount data creating means for obtaining, in the host device, data of an ink amount that can be ejected into the predetermined portion based on image data of a predetermined portion near the boundary for each of the areas; and an ink amount obtained by the ink amount data creating means. Data
Data output means for sending from the host device to the ink jet recording apparatus together with the recording data based on the image data; and ink data recording means for thinning out the predetermined portion of the recording data based on the ink amount data sent from the host apparatus by the data output means. An information processing system, comprising: a thinning unit performed in a device. 2. The information processing system according to claim 1, wherein the ink amount data is sent in a data form different from print data. 3. The thinning-out means refers to a table holding thinning-out probability data based on the ink amount data, and thins out the recording data with the thinning-out probability obtained by the reference. An information processing system according to claim 1. 4. The information processing system according to claim 1, wherein the ink amount data is sent in the same data form as print data. 5. The printing apparatus according to claim 4, wherein the ink amount data and the print data are sent in a binary data form.
An information processing system according to claim 1. 6. The recording apparatus according to claim 5, wherein said thinning means thins out the print data by calculating a logical product of the ink amount data and the print data.
An information processing system according to claim 1. 7. The information processing system according to claim 1, wherein said ink amount data is obtained based on a total of values indicated by image data for each pixel of said predetermined portion. 8. The information processing system according to claim 7, wherein the total is the total of all image data corresponding to the type of ink used in the ink jet recording apparatus. 9. The method according to claim 1, wherein the ink amount data generating means obtains the ink amount data by referring to a table holding the ink amount data according to the proximity from the boundary, based on the total value. Item 7 or 8
An information processing system according to claim 1. 10. An ink-jet printing apparatus which performs printing based on print data sent from a host device, wherein the data is sent from the host device together with print data based on image data, and is formed at the time of printing operation in the ink-jet printing device. Receiving means for receiving data of an ink amount that can be shot into the predetermined portion, which is obtained based on image data of a predetermined portion near the boundary for each of the plurality of recording areas; and based on the ink amount data received by the receiving means. An ink jet recording apparatus comprising: a thinning means for thinning out the print data of the predetermined portion. 11. The apparatus according to claim 1, wherein the ink amount data is sent in a data form different from print data.
0. The ink jet recording apparatus according to 0. 12. The thinning unit according to claim 11, wherein the thinning means refers to a table holding thinning probability data based on the ink amount data, and thins the print data with the thinning probability obtained by the reference. 3. The ink jet recording apparatus according to claim 1. 13. The apparatus according to claim 10, wherein the ink amount data is sent in the same data form as print data.
3. The ink jet recording apparatus according to claim 1. 14. The ink jet recording apparatus according to claim 13, wherein the ink amount data and the recording data are sent in a binary data form. 15. The ink jet recording apparatus according to claim 14, wherein the thinning means performs thinning of the print data by calculating a logical product of the ink amount data and the print data. 16. The ink jet recording apparatus according to claim 10, wherein the ink amount data is obtained based on a total value indicated by image data for each pixel of the predetermined portion. 17. The ink jet recording apparatus according to claim 16, wherein the total is the total of all image data corresponding to the type of ink used in the ink jet recording apparatus. 18. The method according to claim 16, wherein the ink amount data is obtained by referring to a table holding the ink amount data according to the proximity from the boundary, based on the total value. The inkjet recording apparatus according to any one of the preceding claims. 19. An image data correction method for correcting image data used in an ink jet printing apparatus for performing printing based on print data, wherein each of a plurality of printing areas formed during a printing operation in the ink jet printing apparatus is in the vicinity of its boundary. Obtaining data of the amount of ink that can be ejected into the predetermined portion based on the image data of the predetermined portion, and thinning out the print data of the predetermined portion based on the ink amount data to generate print data. An image data correction method characterized by the above-mentioned. 20. The image data correction method according to claim 19, wherein the ink amount data is used in a data form different from print data. 21. The thinning-out step of referring to a table holding thinning-out probability data based on the ink amount data, and thinning out the recording data with the thinning-out probability obtained by the reference. Item 21. The image data correction method according to Item 20. 22. The apparatus according to claim 1, wherein the ink amount data is used in the same data form as print data.
9. The image data correction method according to item 9. 23. The method according to claim 22, wherein the ink amount data and the print data are used in a binary data form. 24. The image data correction method according to claim 23, wherein in the step of performing the thinning-out, the print data is thinned out by calculating a logical product of the ink amount data and the print data. . 25. The image data correction method according to claim 19, wherein said ink amount data is obtained based on a total value indicated by image data for each pixel of said predetermined portion. 26. The image data correction method according to claim 25, wherein the total is the total of all image data corresponding to the type of ink used in the ink jet recording apparatus. 27. The method of claim 27, wherein the step of obtaining the ink amount data comprises obtaining the ink amount data by referring to a table holding the ink amount data in accordance with the proximity to the boundary, based on the total value. The image data correction method according to claim 25 or 26, wherein