JP3431955B2 - Image output apparatus, image forming system including the apparatus, and image output method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image output apparatus for forming (outputting) an image on a print medium, and an image forming system including the apparatus and an image supply apparatus for supplying image data to the apparatus. and relates to an image output method, for example, the fabric used as a print medium, to a textile printing system or the like for printing an image on the fabric.

[0002]

2. Description of the Related Art As an image output device, a device that performs digital image printing by using a print head of an inkjet method, a thermal transfer method, or the like is rapidly becoming popular. In such an image output device, in order to improve the printing speed, a print head in which a plurality of print elements are integrated and arranged (hereinafter referred to as a multi-head in this section)
Is generally used.

For example, in an ink jet print head, a so-called multi-nozzle head in which a plurality of ink ejection ports and liquid paths are integrated is generally used, and a plurality of heaters are also integrated in a thermal transfer system or a thermal system thermal head. It is normal.

However, it is difficult to uniformly manufacture multi-head print elements due to variations in characteristics due to manufacturing processes, variations in head constituent materials, and the like, and variations in characteristics of each print element occur to some extent. For example, in the above multi-nozzle head, variations occur in the shape of the ejection port, liquid path, etc., and in the thermal head, variations in the heater shape, resistance, etc. occur.
Then, such nonuniformity of characteristics among the print elements appears as nonuniformity of dot size and density printed by each print element, and eventually density unevenness occurs in the printed image.

To address this problem, the present applicant has filed Japanese Patent Application Laid-Open No.
No. -18358 and others propose an apparatus in which a density unevenness reading unit is provided in an image forming apparatus to periodically read density unevenness distribution in a print element array range and recreate density unevenness correction data. According to this, even if the density unevenness distribution of the head changes, the correction data is recreated accordingly, so that it is possible to always maintain a uniform image without unevenness.

[0006]

By the way, the image output apparatus is provided with a plurality of print heads for the printing agent of the same color tone, and the print lines are overprinted on the same line to improve the print quality, or different. Some have been trying to improve the printing speed by performing printing on lines. When the image output device performs color printing, a plurality of print heads are provided for each printing agent having a different color tone.

An object of the present invention is to make it possible to efficiently perform density unevenness correction for each print head in a structure in which a plurality of print heads are provided for printing agents of the same color tone and overlapping printing is performed.

Another object of the present invention is to make it possible to perform an appropriate density unevenness correction process in both overlaid printing and non-overlaid printing.

[0009]

To this end, the present invention provides
In an image output device that outputs an image by printing an image on a print medium using a plurality of print heads in which a plurality of print elements are arranged for a printing agent of the same color, printing is performed according to the same image data.
Pixels to be distributed to each of the print heads.
Kicking with, by printing overlapping the image to be printed are distributed to each front Symbol plurality of print heads on the print medium based on the image data, and superimposed printing means for printing an image corresponding to the image data, wherein Means for forming a test image by a plurality of print heads, and based on the result of reading density unevenness in the array of the print elements of the formed test image, at the same print position in the image printing by the overlay printing means. Corresponding correction data generating means for generating correction data commonly used by the print elements of the plurality of print heads, and the plurality of image data inputted from the outside by the overlay printing means. Pudding for each printhead Characterized by comprising a correction means for correcting in correspondence with the element.

In this case, the test image is the plurality of images.
Using the lint head, the preprinting means
One test image overlaid on a print medium
Further, the correction data creating means is
Density data obtained by reading the density of one test image
Is averaged over the number of print heads and
The correction data is created based on the averaged value.
can do.

Further , each of the plurality of print heads
Means for individually forming a test image on the
A test image formed by each of several printheads
From the results of reading the density unevenness for each image,
Density unevenness correction data corresponding to each print head
Head-specific correction data creating means for creating
Can be obtained. And the plurality of print heads
When individually correcting the drive signal with respect to
The processing can be performed in a time-sharing manner.

The plurality of print heads are print media
Are arranged along the transport direction of the
More than one print head is used to print
Overlapping print operation and the plurality of print heads
Non-overlapping pre-prints that print without overlapping each
When performing the above-mentioned overlapping printing
Is the correction data created by the correction data creating means.
When performing the non-overlapping print after correcting with
Is a correction data created by the head-specific correction data creation means.
Correction is performed for each of the multiple print heads using positive data.
You can Further, the image forming system of the present invention
The image output device and the image output device
While supplying image data related to printing,
Do the print operation or the non-overlap print operation.
And an image supply device that gives instructions for
To collect.

In the above image output device, the test image
An image is formed by each of the printheads.
The test image is formed without overlapping.
The positive data creating means is for each of the plurality of print heads.
By individually reading multiple test images formed by this
Based on the density data obtained, the overlay printing means
When printing images with the
Printing of each of the plurality of print heads
Correction data that is commonly used by the elements shall be created.
You can Then, the correction data creating means is
Multiple print heads formed by multiple print heads
Add the density data obtained by reading the strike images individually
The correction data is created based on the
can do.

In the above, two or more prints having different color tones
The image is output with a lint agent and the color tone is changed.
For each of the two or more printing agents
Printhead can be used
It Further, the print head is made of the printing agent.
Ink is used to eject the ink.
It can be a lint head.

Further, according to the present invention, a plurality of print heads in which a plurality of print elements are respectively arranged for the same color tone printing agent are used, and printing is performed according to the same image data.
The printed pixels to each of the printheads.
Ri together divide performs overlapping printing operation to print an image corresponding to the image data by printing overlapping the image to be printed on the print medium distributed to each front Symbol plurality of print heads based on the image data, In an image output method for outputting an image to a print medium, based on a step of forming a test image by the plurality of print heads, and a result of reading density unevenness in an array of the print elements of the formed test image, A correction data creating step of creating correction data commonly used by the print elements of the plurality of print heads, which correspond to the same print position in printing of images by the overlapping print operation;
A correction step of correcting image data input from the outside in accordance with the print elements of each of the plurality of print heads that print the image data by the overlapping print operation, and the image data is corrected by the correction step. It is characterized in that printing is performed by the overlapping printing operation based on image data.

Here, the test image is the plurality of images.
Using the lint head, the
One test image overlaid on a print medium
In addition, in the correction data creating step,
The density data obtained by reading the density of the test image
Is averaged over the number of print heads,
Creating the correction data based on the averaged values
Can be

Further , the test image includes the plurality of pre-printed images.
The test image formed by each front head
The correction data creation step is
A plurality formed by each of the plurality of print heads
The density data obtained by individually reading the test images of
Based on the above, the image is printed by the overlapping printing means.
At the same print position,
Supplementary print head common to each print head
It may be intended to create positive data. And
The correction data creating step is performed by the plurality of print heads.
Individually read multiple test images created by each
Based on the sum of the concentration data obtained,
The correction data may be created.

Further, according to the present invention, a plurality of print heads each having a plurality of print elements arranged for the same color tone printing agent are used to print according to the same image data.
The printed pixels to each of the print heads.
With split performs overlapping printing operation to print an image corresponding to the image data by printing overlapping the image to be printed on the print medium distributed to each front Symbol plurality of print heads based on the image data, print An image output method for outputting an image to a medium, wherein:
A step of determining whether to perform a common correction or a different correction; and when the determination step determines that a common correction is to be performed on the plurality of print heads, the plurality of print heads Form a test image, read the test image, and based on the result of the read, commonly correcting drive signals of the plurality of print heads at the time of outputting the image; and the plurality of print heads by the determination step. When it is determined that different corrections are to be applied to each of the print heads, a test image is formed separately by the plurality of print heads, the test image is read, and the different density obtained by reading the test image is read. A step of individually correcting drive signals for the plurality of print heads based on the data.

Here, with respect to the plurality of print heads,
When individually correcting the drive signal,
It can be performed in a time-sharing manner. In addition,
The lint head is placed in the print medium transport direction and
Onto the print medium using the plurality of print heads
Of the overlapping print operation or the plurality of print operations
Print without overlapping the prints of each
Overlap printing operation is possible,
If the print operation is determined, the common
It is determined that the correction is performed and the non-overlap printing operation is performed.
If the above is specified, each of the above corrections shall be performed.
You can

In any of the above image output methods,
Image output using two or more printing agents with different color tones
In addition, two or more printing agents with different color tones
Multiple print heads are used for each
Can be one. In addition, one of the above
In the image output method, the print head is
Ink that uses an ink as a coating agent and ejects the ink
It can be a jet print head.

Also, in any of the above image output methods
Ink is applied to the print medium to output an image.
Fixing the ink on the print medium after performing
Can be further equipped. Then, set the ink
After the dressing process, print the printed media
The method may further include a step of cleaning treatment.

In any of the above image output methods,
The ink jet from the print head.
Before including a pretreatment agent in the print medium before printing
It may further comprise a treatment step.

[0023]

According to the present invention, for example, one test image is formed by a plurality of print heads provided for a printing agent having the same color tone, and the density data obtained by reading the test image is averaged by the number of heads. By commonly correcting the drive signals of the plurality of print heads based on the average value, it is possible to efficiently perform the density unevenness correction processing of the heads when performing overlapping printing using the plurality of print heads.

Further, means for forming a test image for each of the plurality of print heads, and each of the plurality of print heads based on the respective density data obtained by reading the test image. By further comprising a means for correcting the drive signal and performing different density unevenness correction during non-overlapping printing, it is possible to perform appropriate correction according to the print mode.

[0025]

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

In the following, a textile printing system as a preferred embodiment of the present invention will be described in the following procedure.

(1) Overall system (FIGS. 1 and 2) (2) Host computer (FIG. 3) (2.1) Configuration (2.2) Operation (3) Printer (FIGS. 4 to 31) (3) 1) Description of printing mechanism (3.2) Description of device configuration (3.3) Description of printing method (3.4) Description of head shading (4) Others (1) Overall system FIG. 1 shows an overall configuration of a textile printing system according to an embodiment. The host computer H serves as a data supply device that supplies original image data for printing and other control commands to a printer P that prints (hereinafter also referred to as printing) on a print medium such as cloth. Using this host computer H, it is possible to make desired corrections to the original image created by the designer and read by the scanner S, and set the required parameters for the printer P to perform printing. The host computer H also has a LAN (local area network) 10 such as Ethernet (by XEROX).
It is possible to connect with 16 to enable communication with other systems. In addition, the printer P notifies the host computer H of its status and the like. Details will be described later with reference to FIG. 3 for the host computer H and FIG. 4 for the printer P.

FIG. 2 shows an example of a printing process procedure that can be performed using this system. The processing contents performed in each step are as follows, for example.

Original image creating step This is a step in which the MS1 designer uses an appropriate means to create an original image, that is, a basic image which is a basic unit of a repeating image on a cloth as a print medium. In the creation, necessary parts of the host computer H which will be described in detail with reference to FIG.
For example, input means or display means can be used.

Original image input step MS3 Step of reading the original image created in the original creating step MS1 into the host computer H using the scanner S, or reading the original image data stored in the external storage of the host computer H, or This is a step of receiving original image data from the LAN 1016.

Original image correction step MS5 The textile printing system in this example allows selection of various repeating patterns for the basic image, as will be described later with reference to FIG. Image misalignment or color tone discontinuity may occur. This step is a step of receiving the selection of the repeating pattern and correcting the discontinuity at the boundary portion of the repeating pattern according to the selection.
As a mode of the correction, the designer or the operator may use the mouse or other input means while referring to the screen of the display device of the host computer H, and the automatic correction is performed by the image processing of the host computer H itself. It may be one.

Special Color Designating Step MS7 In the printer P according to this example, basically, yellow (Y),
Printing is performed using magenta (M) and cyan (C), or even black (BK) ink. In printing, colors other than these, for example, metallic colors such as gold and silver, and clear red (R) are used. , Green (G), Blue (B), etc. may be desired. Therefore, in the printer P of this example, it is possible to perform printing using inks of these special colors (hereinafter referred to as special colors), and
In this step, the spot color is designated.

Color Palette Data Creation Step In MS9 design, the designer creates an original image while selecting colors from standard color patches. The reproducibility of the color when printing the selected color greatly affects the productivity of the printing system. Therefore, in this step, data for determining the mixing ratio of Y, M, C, or the special color for favorably reproducing the selected standard color is generated.

Logo input step MS11 In the case of a piece of cloth, a logo mark of a designer, a brand of a manufacturer or the like is often printed on the end portion. In this step, such a logo mark is designated and its color, size and position are designated.

Cloth size specifying step MS13 The width, length, etc. of the cloth to be printed are specified. As a result, the scanning amount of the print head in the printer P in the main scanning direction and the sub scanning direction, the number of repetitions of the original image pattern, etc. are determined.

Original image magnification designation step MS15 Variable magnification at the time of printing the original image (for example, 100%, 2
00%, 400%, etc.) is set.

Cloth type designating step MS17 cloth has various kinds such as natural fibers such as cotton, silk and wool, and synthetic fibers such as nylon, polyester and acrylic, and has different characteristics relating to printing. It is considered that this is due to the elasticity of the cloth, but when the feed amounts at the time of printing are made equal, the appearance of streaks occurring at the boundary portion for each main scan differs. Therefore, in this step, the type of cloth for printing is input so that the printer P can be used to set an appropriate feed amount.

Maximum ink ejection amount setting step MS19 Even when the same amount of ink is ejected onto the cloth, the image density reproduced on the cloth differs depending on the cloth type. The amount of ink that can be ejected also differs depending on the configuration of the fixing system in the printer P and the like. Therefore, in this step, the maximum ink ejection amount is designated according to the cloth type, the configuration of the fixing system of the printer P, and the like.

Print Mode Designating Step MS21 Printer P does not perform multi-scan overlay printing (see FIG. 20). High-speed print mode is executed or multi-scan overlay printing (see FIG. 1).
No. 8, FIG. 19, etc.) is executed, or whether one dot of ink is ejected once or a plurality of times of ink is ejected. Furthermore, when printing is interrupted, control is performed so that the patterns continue before and after the interruption, or whether new printing is started regardless of the pattern continuity. You can also

Head Shading Mode Designating Step MS23 When a print head having a plurality of ejection ports is used in the printer P, the ink ejection amount and ejection direction for each ejection port of the head are changed due to manufacturing variations and subsequent usage conditions. There may be variations and deviations. Therefore, in order to correct this, processing (head shading) may be performed to correct the drive signal for each ejection port to keep the print density constant. In this step, the mode of head shading according to the print mode, the timing of head shading, etc. can be designated.

Printing is performed by the printer P based on the designations in the printing step MS25 and above.

If it is unnecessary to specify the above, the step may be deleted or skipped. Moreover, you may add the step which performs other designation | designated etc. as needed.

(2) Host Computer (2.1) Configuration FIG. 3 is a block diagram showing the entire system centering on the configuration of the host computer according to one embodiment of the present invention.

In the figure, 1011 is a CPU for executing control of the entire information processing system, and 1013 is a CPU 101.
1 stores a program to be executed by 1 and is used as a work area at the time of execution. A main memory 1014 transfers data between the main memory 1013 and various devices constituting the system without the CPU 1011. DMA controller (Direct Memory A)
access controller (hereinafter referred to as DMAC). 1015 is a LAN interface between the LAN 1016 and this system, and 1017 is a ROM, S
It is an input / output device (hereinafter referred to as I / O) having a RAM, an RS232C system interface, and the like. I / O
Various external devices can be connected to 1017. 101
Reference numerals 8 and 1019 denote a hard disk device and a floppy disk device as external storage devices, respectively.
Reference numeral 0 is a disk interface for signal connection between the hard disk device 1018 or the floppy disk device 1019 and this system. Reference numeral 1022 denotes a scanner / printer interface for signal connection between the printer P and the scanner S and the host computer H, which can be of the GPIB specification.
Reference numeral 1023 is a keyboard for inputting various kinds of character information, control information, and the like, 1024 is a mouse as a pointing device, and 1025 is a key interface for performing signal connection between the keyboard 1023 and the mouse 1024 and this system. Reference numeral 1026 denotes a display device such as a CRT whose display is controlled by the interface 1027. Reference numeral 1012 is a system bus composed of a data bus, a control bus, and an address bus for connecting signals between the above-mentioned devices.

(2.2) Operation In the system described above, in which various devices are connected, the designer or operator operates while corresponding to various information displayed on the display screen of the CRT 1026. That is, an external device connected to the LAN 1016, I / O 1017, a hard disk 1018, a floppy disk 1019, a scanner S, a keyboard 102.
3. Characters and image information supplied from the mouse 1024, operation information related to system operation stored in the main memory 1013, and the like are displayed on the display screen of the CRT 1026, and the designer or operator can see various information while viewing this display. Designate and instruct the system.

(3) Printer (3.1) Description of Mechanical Structure FIG. 4 shows an example of the structure of an ink jet printer as a textile printing apparatus of this embodiment, and FIG. 5 shows an enlarged perspective view of the main part thereof.
The printing apparatus (printer) of this example is roughly divided into a cloth feeding section B that sends out a cloth on a roll that has been subjected to a pretreatment for printing,
It is composed of a main body section for precisely feeding the fed cloth and printing with an inkjet head, and a winding section C for drying and winding the printed cloth. The main body portion A further includes a cloth precision feed portion A-1 including a platen and a print unit A-2.

The pre-processed roll-shaped cloth (cloth) 3 is sent out toward the cloth feeding portion and sent to the main body portion A. A thin endless belt 6 which is precisely step-driven is wound around a drive roller 7 and a winding roller 9 in the main body. The drive roller 7 is a high resolution stepping motor (not shown).
Is directly step-driven by and the belt is step-fed by the step amount. The sent cloth is pressed by the pressing roller 10 against the belt surface backed up by the winding roller 9, and the print surface is regulated to be flat.

The cloth 3 stepwise fed by the belt is positioned by the platen 12 on the back surface of the belt in the first printing section 11 and printed by the ink jet head 13 from the front side. Each time one line of printing is completed, a predetermined amount of step feed is performed, then heating from the back surface of the belt by the heating plate 14 and the warm air duct 1
5 is dried by hot air from the surface which is supplied / exhausted. Then, in the second printing unit 11 ', the first
Overprinting is performed in the same manner as the printing unit of.
Note that the warm air duct 15 does not necessarily have to be provided, and even if it is omitted, natural drying is also performed in the area from the first printing unit 11 to the second printing unit 11 '.

The cloth after printing is peeled off, dried again in the same post-drying section 16 as the heating plate 14 and the duct 15 described above, guided to the guide roll 17 and wound on the winding roll 18. Then, the wound cloth is removed from the apparatus, and color development, washing, and drying are performed in a batch process to obtain a product.

In FIG. 5, the cloth 3, which is a print medium, is supported by the belt 6 and is step-fed upward in the drawing. In the first printing unit 11 at the lower part of the drawing, there is a first carriage 24 carrying Y, M, C, BK, and inkjet heads for the special colors S1 to S4.
Inkjet head (print head) in this example
Uses an element having a heat energy generating element that causes film boiling in the ink as the energy used for ejecting the ink, and has a density of 400 DPI (dots / inch) of 128 or 256 pieces. An array of discharge ports is used.

On the downstream side of the first printing section, there is provided a drying section 25 comprising a heating plate 14 for heating from the back side of the belt and a warm air duct 15 for drying from the front side. The drying process by the drying unit 45 is mainly for evaporating the ink solvent adhering to the print medium, and is different from the diffusion or fixing process described later. The heat transfer surface of the heating plate 14 is pressed against the endless belt 6 which is strongly tensioned, and the high temperature and high pressure steam passing through the hollow inside strongly heats the conveyor belt 6 from the back side. The inside of the heating plate surface is provided with fins 14 'for collecting heat so that the heat can be efficiently concentrated on the back surface of the belt. The side not in contact with the belt is covered with a heat insulating material 26 to prevent loss due to heat dissipation.

On the front side, by blowing hot dry air from the supply duct 27 on the downstream side to the cloth which is being dried,
The effect is enhanced by applying air with lower humidity. The air flowing in the opposite direction to the cloth conveying direction and containing a sufficient amount of water sucks a much larger amount than the amount of spraying from the suction duct 28 on the upstream side, so that evaporated water leaks and Avoid condensation on mechanical devices. The supply source of warm air is on the back side of FIG. 5, and suction is performed from the front side, and the pressure difference between the blowing port 29 and the suction port 30 facing the cloth is uniform over the entire longitudinal direction. It is designed to be. The air blower / sucker is offset downstream with respect to the center of the rear heating plate so that the air hits the fully heated location. As a result, the first printing unit 11 strongly dries a large amount of water contained in the ink including the thinning liquid received by the cloth.

The second printing unit 1 is provided downstream (upper) thereof.
1 ', and the second carriage 24' having the same structure as the first carriage forms the second print portion.

After the above-described drying (including natural drying), the dye contained in the ink, such as the dye on the fabric fiber, is diffused by using a means for fixing the dye contained in the ink, and A step of fixing the dye to the fiber can be performed. By this step, sufficient color developability and fastness due to dye fixation can be obtained.

This diffusion and fixing step (including a dye diffusion step, a fixed color development step, etc.) may be a conventionally known method, such as a steaming method (for example, treatment in a steam atmosphere at 100 ° C. for 10 minutes). Can be mentioned. In this case, the cloth may be previously subjected to an alkali treatment as a pretreatment before the printing step. Further, the fixing process may or may not include a reaction process such as ionic bonding depending on the dye. An example of the latter is one in which the fibers are impregnated and do not physically separate. Any appropriate ink can be used as long as it contains a required coloring matter, and it is not limited to a dye and may contain a pigment.

Then, in the post-treatment step, the unreacted dye and the substance used for the pre-treatment are removed.
Finally, the print is completed through a finishing process such as defect correction and ironing.

As the print medium, in addition to the above cloth (cloth 3), wall cloth, thread used for embroidery, wallpaper, and the like can be cited.

In the present invention, the cloth means a material,
Includes all woven, non-woven and other fabrics, whether woven or knitted.

In particular, as a fabric for ink-jet printing, (1) the ink can be developed to a sufficient density,
(2) High ink dyeing rate, (3) Ink dries quickly on the cloth, (4) Rare ink bleeding on the cloth is small, (5) In-apparatus It is required to have excellent performance such as excellent transportability. In order to satisfy these required performances, the fabric may be subjected to pretreatment in advance using a means for containing a treatment agent, if necessary. For example, Japanese Patent Laid-Open No. 62-5349
No. 2 discloses a fabric having an ink receiving layer, and Japanese Patent Publication No. 3-46589 proposes a fabric containing a reduction inhibitor and an alkaline substance. Examples of such pretreatment include a treatment in which the cloth is made to contain a substance selected from alkaline substances, water-soluble polymers, synthetic polymers, water-soluble metal salts, urea and thiourea.

Examples of the alkaline substance include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide,
Examples thereof include amines such as mono-, di- and triethanolamine, and carbonic acid or alkali metal bicarbonate such as sodium carbonate, potassium carbonate and sodium bicarbonate. Furthermore, there are organic acid metal salts such as calcium acetate and barium acetate, and ammonia and ammonia compounds. Also, sodium trichloroacetate, which becomes an alkaline substance under steaming and dry heat, can be used. Particularly preferred alkaline substances are sodium carbonate and sodium bicarbonate used for dyeing reactive dyes.

Examples of the water-soluble polymer include starch substances such as corn and wheat, cellulosic substances such as carboxymethylcellulose, methylcellulose and hydroxyethylcellulose, sodium alginate, gum arabic,
Locust bean gum, tragacanth gum, guar gum,
Examples include polysaccharides such as tamarind seeds, protein substances such as gelatin and casein, and natural water-soluble polymers such as tannin-based substances and lignin-based substances.

Examples of synthetic polymers include polyvinyl alcohol compounds, polyethylene oxide compounds, acrylic acid water-soluble polymers, maleic anhydride water-soluble polymers and the like. Among these, polysaccharide polymers and cellulose polymers are preferable.

Examples of the water-soluble metal salt include compounds such as halides of alkali metals and alkaline earth metals, which produce typical ionic crystals and have a pH of 4 to 10. As a typical example of such a compound, for example, in the case of an alkali metal, NaCl, Na ₂ SO
₄ , KCl, CH ₃ COONa, etc., and the alkaline earth metals include CaCl ₂ and Mg.
Cl _{2 and the} like can be mentioned. Of these, salts of Na, K and Ca are preferable.

The method of incorporating the above substances and the like into the cloth in the pretreatment is not particularly limited, and examples thereof include a dipping method, a pad method, a coating method and a spraying method which are usually carried out.

Further, the printing ink applied to the ink-jet printing cloth merely adheres to the cloth when it is applied to the cloth. Therefore, as described above, the step of fixing the dye in the ink such as dye to the fiber is continued. Is preferably applied.
Such a fixing step may be a conventionally known method, for example, a steaming method, an HT steaming method, a thermofix method, an alkali pad steam method, an alkali blotch steam method, when a cloth which has been previously alkali-treated is not used. The alkali shock method, the alkali cold fix method and the like can be mentioned.

Further, the unreacted dye and the substance used in the pretreatment are removed after the fixing step by using a means for washing the print medium in accordance with a conventionally known method, and water containing a neutral detergent dissolved therein is used. It can be performed by washing with hot water or the like. In addition, it is preferable to use a conventionally known fixing treatment (a treatment for fixing a dye which is likely to fall off) at the time of this washing.

The printed matter which has been subjected to the above-mentioned post-processing step is then cut into a desired size, and the cut pieces are sewn, bonded, welded, etc. to obtain a final processed product. After that, clothes such as dresses, dresses, ties, swimwear, duvet covers, sofa covers, handkerchiefs, curtains, etc. can be obtained. Many methods of processing cloth by sewing or the like to make clothes and other daily necessities are described in publicly known books such as the monthly magazine "Souen" (published by Bunka Publishing Bureau).

FIG. 6 illustrates the speed at which the carriage of the first and second printing units 11 and 11 'in FIG. 4 scans the cloth surface for printing.

The movement of the carriage speeds up gradually from the start position, and in the print area,
When the print area ends (constant speed area) due to constant speed motion, the speed is reduced in the deceleration area and stopped at the reverse position.

After that, the movement to return to the start position starts. However, the reversal without printing usually makes a faster movement than the printing, and improves the productivity of the machine. Reference numeral 30 represents a motion when thinning printing is performed, and 31 represents a motion in a mode for increasing the density.

FIG. 7 shows a density unevenness correction section 237 including an HS test pattern printing section and a test pattern reading section provided on the side of the apparatus opposite to that of FIG. Reference numeral 213 is a print medium for a test pattern, which is provided at the scanning position of the upper and lower carriages and can be printed by the inkjet heads of the first and second printing units 11 and 11 '.
The motor 216 is stretched between the rollers 216A and 216B.
The sheet M is conveyed in the direction D in the figure. Then, as described above, the print medium 21 on which the test pattern is printed is printed.
3 is illuminated by the light source 218, the print density of the test pattern printed on the print medium 213 by each inkjet head is read by the read line sensor 217, and the read signal of the test pattern print by each print head read by the read sensor 217. Are converted into digital signals by the A / D converter 236 as R, G, B signals, and the read signals are temporarily stored in the RAM 2
It is stored in 19.

(3.2) Configuration of Control System of Device Next, the configuration of the control system of this device will be described. 8 and 9 show the configuration of the ink jet printer of the embodiment and the configuration example of the operation unit thereof, and FIGS. 10 to 12 show an example of the internal configuration of the control board 102 of FIG. 8 along the data flow. It is shown in the figure.

From the host computer H via the interface (here, GPIB), the control board 1
The image data for printing is sent to 02. The device for sending the image data is not particularly limited, and the transfer form may be transfer via a network or offline via a magnetic tape or the like. The control board 102 is the CPU 102.
A, the ROM 102B storing various programs, the RAM 102C having various register areas and work areas, and each unit shown in FIGS. An operation / display unit 103 has an operation unit for the operator to give a desired instruction to the printer P and a display for displaying a message to the operator. Reference numeral 104 denotes a cloth transporting machine including a motor and the like for transporting a print medium such as cloth to be printed. Reference numeral 105 denotes a driver unit input / output unit for driving various motors (shown by "M" at the end) and various solenoids (shown by "SOL") shown in FIG. 107 supplies a drive signal to each head,
It is a relay board for receiving information about each head (information such as whether or not the head is mounted and the color presented by the head) and supplying the information to the control board 102. The information is transferred to the host computer H as described above.

Now, when the information of the image data to be printed is received from the host computer H, the image data is GPI.
The image is stored in the image memory 505 via the B interface 501 and the frame memory controller 504 (see FIG. 10).
reference). The image memory of the embodiment has a capacity of 124 Mbytes, and has an A1 size of 8-bit palette data. That is, 8 bits are assigned to each pixel. 503 is D for speeding up memory transfer
It is an MA controller. When the transfer from the host computer H is completed, printing can be started after a predetermined process.

Before and after the description, the host computer connected to the printing apparatus of the embodiment transfers the image data as a raster image. Since each print head has a plurality of ink ejection nozzles arranged in the vertical direction, the arrangement of image data must be converted to match the print head. This data conversion is performed by the raster @BJ conversion controller 506. Then, the data converted by the raster @BJ conversion controller 506 is supplied to the palette conversion controller 508 through the expansion function of the next expansion controller 507 for scaling the image data.
The data up to the expansion controller 507 is the data sent from the host computer, and in this embodiment is an 8-bit palette signal. Then, this palette data (8 bits) is commonly passed to and processed by a processing unit (described below) for each print head.

In the following description, it is assumed that there are eight print heads, that is, a head that stores specific colors S1 to S4 in addition to yellow, magenta, cyan, and black is provided.

The palette conversion controller 508 supplies the palette data input from the host computer H and the corresponding color conversion table to the conversion table memory 509.

In the case of an 8-bit palette, the number of reproducible color types is 256 from 0 to 255. For example,
The table as shown in FIG. 13 is expanded in the table memory 509 corresponding to each color.

In the case of an 8-bit palette, the number of reproducible color types is 256 from 0 to 255. For example, when 0 is input, light gray printing is performed, 1 is input, solid printing of special color 1 is performed. When 2 is input Solid color of special color 2 is input 3 When blue is printed by mixing cyan and magenta 4 When cyan is solid print 5 When 5 is input Mixed color of magenta and yellow In the case where the print of the color of the let system 254 is input, in the case where the solid print of the yellow 255 is input, the process of not printing anything is performed.

As a concrete circuit configuration, the palette conversion table memory 509 fulfills its function by writing the conversion data in the address position for the palette data. That is, when the palette data is actually supplied as an address, the memory is accessed in the read mode. The palette conversion controller 508 manages the palette conversion table memory 509 and interfaces the control board 102 and the palette conversion table memory 509. Regarding the spot color, a circuit for setting the spot color mixture amount (a circuit for multiplying the output by 0 to 1) is inserted between the HS system including the HS controller 510 and the HS conversion table memory 511 at the next stage, and the set amount is set. Can be variable.

The HS conversion controller 510 and the HS conversion table memory 511 use the print density corresponding to each ejection port of each head based on the data measured by the head characteristic measuring means 108 including the density unevenness correction section shown in FIG. The variation of is corrected. For example, data with a low density (low ejection rate) is converted to darker data, and a port with high density (high ejection rate) is converted to lighter data, and a medium density ejection port is converted. In that case, the process of flowing it as it is is performed. This process will be described later.

The next γ conversion controller 512 and γ conversion table memory 513 are table conversions for increasing or decreasing the overall density for each color. For example, when nothing is done, it is a linear table, 0 output for 0 input, 100 output for 100 input, 210 output for 210 input, and 255 output for 255 output.

The next-stage binarization controller 514 has a pseudo gradation function, inputs 8-bit gradation data, and outputs binarized 1-bit pseudo gradation data. is there. Although there are a dither matrix, an error diffusion method, and the like for converting multi-valued data into binary data, these are adopted also in the embodiment, and the detailed description thereof will be omitted, but in any case, the unit What is necessary is just to express gradation by the number of dots per area.

The binarized data is stored in the connection memory 515 and then used for driving each print head. Then, the binary data output from each connection memory is output as C, M, Y, BK, S1 to S4. Since the same processing is performed on the binarized signals of the respective colors, the binary data C will be focused here and described with reference to FIG. It should be noted that the drawing shows the configuration for the print color cyan, and has the same configuration for each color. Note that FIG. 12 shows the connection memory 515 shown in FIGS.
3 is a block diagram showing a circuit configuration of a stage subsequent to that of FIG.

The binarized signal C is a sequential multi-scan generator (hereinafter, SMS generator) 5
22 is output to the pattern generator 51.
In some cases, the test printing of the device alone is performed by the 7, 518, so the data is supplied to the selector 519. Of course, this switching is controlled by the CPU of the control board 102, and the operator operates the operation unit 103.
When a predetermined operation is performed on (see FIG. 8), the data from the binary pattern controller 517 is selected for test printing. Therefore, normally, the data from the binary controller 514 (connecting memory 516) is selected. 520 is a selector 520 and an SMS
This is a logo input section that is inserted between the generator 522 and the printer 522. In the case of textile printing, a logo mark such as a brand of a maker or a designer is often put on the end of the cloth, which is compatible with this. The configuration can be made up of, for example, a memory that stores logo data, a controller that manages a print position, and the like, and step MS11 in FIG.
You can make the required specifications at.

The SMS generator 522 prevents unevenness in image density due to changes in the discharge amount of each nozzle. Multi-scan is, for example, Japanese Patent Application No. 4-79858.
It has been proposed as an issue. Whether to prioritize image quality by performing multi-scan, that is, by ejecting ink from a plurality of ejection ports for one pixel, or prioritizing high speed without performing such multi-scan, FIG. Can be specified in step MS21. This SMS
The printing method controlled by the generator 522 will be described later.

The connection memory 524 is a buffer memory that corrects the physical position of the head, that is, the position between the upper and lower print units in FIG. 5 and the position between the heads. Output at a timing according to the physical position of the head. Therefore, the connection memory 524 has a different capacity for each print color.

After the data processing as described above is performed, the data is sent to the head via the head relay board 107.

By the way, conventionally, the data for palette conversion and γ conversion has been fixedly held in the memory provided in the main body of the apparatus. Therefore, it may not match the image data to be output, and an image of sufficient quality may not be obtained. Therefore, in the present embodiment, these conversion data can be input from the outside and are stored in each conversion table memory. For example, palette conversion data as shown in FIG. 13 is downloaded to the conversion table memory 509.
That is, the conversion table memories 509 and 511 of the embodiment are
All of 513 are composed of RAM. The data for palette conversion and γ conversion is sent from the host computer 101. Further, the data for HS conversion is input from the head characteristic measuring instrument 108 including the configuration shown in FIG. 7 so that the data always matched to the state of the head can be obtained. In order to obtain the head characteristic of each print color by the head characteristic measuring device 108, test printing (printing with uniform predetermined halftone density) is performed with each print head. Then, the density distribution corresponding to the print width is measured. The state of the head is the dispersion of the ejection states of a plurality of nozzles included in the head, or how much the density of the image printed by the head is different from the desired density.

Further, in the present embodiment, in order to prevent the abnormal output and the like until the conversion parameter is input, even if data is input, the output is set to 0 and printing is performed, as shown in FIG. I was not allowed to. The same applies to γ conversion and the like.

(3.3) Description of Print Method FIG. 15 shows certain print data, and a rectangular area surrounded by a dotted line corresponds to one pixel, and in the case of 400 DPI, it is about 63.5 μm square. In the figure, the place where a black dot is printed indicates that it is a pixel for printing an image. The print head h moves in the direction shown, and ink is ejected from the ink ejection port at a predetermined timing to perform printing as shown in FIG.

Here, the sequential multi-scan is the head movement direction in order to correct the variation in the size of the ink droplets ejected from each ejection port and the concentration variation between the ejection ports caused by the variation in the ink ejection direction. Is a method of printing the same line in a plurality of ejection ports. By thus forming one line with a plurality of ejection ports, it is possible to reduce the unevenness by utilizing the randomness of the ejection characteristics. When performing the sequence multi-scan by scanning twice, the head on the side of the first printing unit 11 shown in the lower side of FIG. 4 and the head on the side of the second printing unit 11 ′ shown in the upper side of FIG. Besides doing
For one head, for example, by using the upper half of the head in the first scan and the lower half in the second scan, an odd number of print data in the head moving direction (see FIG.
6) is printed on the upper half of the discharge port group and even-numbered (Fig. 1).
7) can be printed by the lower half ejection port group. This is a means for preventing the print quality from deteriorating due to the unevenness of ink ejection that occurs at each ejection of the inkjet head, and an effect similar to head shading can be obtained.

18 to 21 show various printing methods selectable in this embodiment.

FIG. 18 shows an ordinary type using the head on the first printing section side and the head on the second printing section side shown in FIG.
It is a print with multiple multi-scans. Areas printed by the lower head on the side of the first printing unit 11 in FIG. 5 are shown as “lower 1”, “lower 2”, and “lower 3”, and areas printed by the upper head are “upper 1”, It is shown as "upper 2" and "upper 3".

The cloth feed direction is as shown by the arrow in the figure, and the step feed amount per time is the head width. As can be seen from the figure, all areas are composed of the upper half of the upper head and the lower half of the lower head, or the lower half of the upper head and the upper half of the lower head. As a result of being cut and superposed by both heads, a predetermined density is obtained. The head scan speed at this time is V1 × 2.

FIG. 19 shows a case where the print density is doubled as compared with FIG. The difference from FIG. 18 is that the print data is not thinned and the carriage speed is halved. The SMS generator 522 of FIG.
Then, in the case of FIG. 18, data distribution is executed,
In the case of FIG. 19, this is not done. Also, speed 1
The reason for setting // 2 is related to the ink refill frequency of the head.

Compared to FIG. 18, FIG. 20 eliminates thinning,
And the cloth feed amount is doubled. Further, the upper and lower head spacing is changed to an integral multiple of the head width L0. Therefore, it is possible to provide means for variably adjusting the distance between the first and second printing units 11 and 11 'in FIG. 4, but in the print shown in FIG. 4, the head distance is as shown in FIGS. Even with (N + 0.5) × L0 ″, it is possible to adjust the cloth feed amount and the scan timing of the upper and lower heads.

FIG. 21 shows still another printing method.
This is because the print is performed by scanning the upper and lower heads once each in total in FIG.
Printing is performed by scanning the upper and lower heads twice, a total of four times. In this method, the SMS generator 522 has thinning /
There is an advantage that the design can be simplified, that is, there is no need to create a mode without thinning and there is no need to switch the speed of the scanner.

(3.4) Description of Head Shading The image signal read from the test pattern described later is sent to the image forming unit and is used for the correction of the drive condition of the print head as described later.

In the present invention, the adjustment to prevent uneven density during image formation means to make the image density of the liquid droplets from a plurality of liquid discharge ports of the print head uniform in the print head itself, or To make the image density uniform among a plurality of heads, or to make a desired color by mixing a plurality of liquids to obtain a desired color or to obtain a desired density. It includes at least one, and preferably includes satisfying a plurality of these.

As the density uniformization correction means therefor,
It is preferable that the reference print giving the correction condition is automatically read and the correction condition is automatically determined, and it is not a matter not to add a manual adjustment device for fine adjustment and user adjustment.

The correction purpose determined by the correction condition is
Not only optimum printing conditions but also adjustment within a predetermined range including an allowable range and a reference density that changes according to a desired image may be used, and all that are included in the purpose of correction can be applied.

As an example, a case will be described in which density unevenness correction of a multi-head with the number of print elements N is performed so that the print output of each element is converged to an average density value for the purpose of correction.

It is assumed that a density distribution is generated when each element (1 to N) is driven by a certain uniform image signal S to print.

First, the density of the portion corresponding to each print element
Measure OD _1- OD _N

[0106]

[Outer 1]

[0107] This average density is not limited to each element, but may be a method of integrating the amount of reflected light to obtain an average value or a known method.

If the relationship between the value of the image signal and the output density of a certain element or a certain element group is as shown in FIG.
For the signal actually given to this element or this element group, the correction coefficient α for correcting the signal S to bring about the target density bar OD may be determined. That is, the signal S is expressed as α × S = (bar OD /
The correction signal S corrected to OD _n ) × S may be given to this element or group according to the input signal S. Specifically, it is executed by subjecting the input image signal to table conversion as shown in FIG.

In FIG. 22B, a straight line A is a straight line having a slope of 1.0 and is a table for outputting an input signal without conversion, but a straight line B has a slope α = bar OD / O.
It is a straight line of D _n and is a table for converting an output signal into α · S with respect to an input signal S. Therefore, if the head drive is performed after performing table conversion on the image signal corresponding to the n-th print element for determining the correction coefficient α _n for each table as shown by the straight line B in FIG. Each density of the part printed by the individual printing elements is equal to the bar OD. If such a process is performed on all print elements, the uneven density is corrected and a uniform image is obtained. That is, the unevenness can be corrected by previously obtaining data as to what kind of table conversion should be performed on the image signal corresponding to which print element.

Needless to say, this objective correction may be carried out by comparing the densities of the respective nozzle groups (3 to 5 units) as an approximate uniformization process.

The density unevenness can be corrected by such a method. However, the density unevenness can be corrected depending on the use condition of the apparatus or environmental changes, or the density unevenness before correction or the correction circuit with time. Therefore, it is necessary to change the correction amount of the input signal in order to cope with such a situation. The cause of this is
In the case of an inkjet print head, it is conceivable that the density distribution may change with use due to the deposition of deposits from the ink in the vicinity of the ink ejection port or the deposition of foreign matter from the outside. This is also predicted from the fact that the density distribution may change due to deterioration or deterioration of each heater in the thermal head. In such a case, for example, since the uneven density correction cannot be sufficiently performed with the input correction amount initially set at the time of manufacturing or the like, the problem that the uneven density gradually becomes conspicuous as it is used is also a problem in long-term use. It becomes a problem to be solved.

FIG. 23 shows an example of the configuration of the control system of the present apparatus centering on the head shading (HS) system. Here, h is a print head, which is a representative of each head in the first and second printing units in FIG.

Reference numeral 718 is an unevenness correction signal, and 717 is an unevenness correction RAM. Further, 720 is an ejection recovery means for improving the ejection state of the print head h by performing suction or the like, and 725 is a means for causing the print head to scan the print medium or the test pattern print medium.

As described above with reference to FIG. 11, the palette-converted signal 704 is sent to each HS conversion table memory 50.
9 is converted so as to correct the unevenness of the print head. The unevenness correction table has 64 correction straight lines, and the correction straight line (or a non-linear curve can be used) is switched according to the unevenness correction signal 718.

FIG. 24 shows an example of the unevenness correction table.
In this example, there are 64 correction straight lines each having a different slope from Y = 0.68X to Y = 1.31X by 0.01, and the correction straight lines are switched according to the unevenness correction signal 718. For example, when a signal of a pixel to be printed with an ejection port with a large dot diameter is input, a correction straight line with a small inclination is selected, and conversely, with a discharge port with a small dot diameter, a correction straight line with a large inclination is selected to output an image signal. to correct.

The unevenness correction RAM 717 stores a selection signal of a correction straight line necessary to correct the unevenness of each head. That is, the unevenness correction signals having 64 kinds of values of 0 to 63 are stored for the number of ejection ports, and the unevenness correction signal 718 is output in synchronization with the input image signal. And
The signal 706 in which the unevenness is corrected by the straight line selected by the unevenness correction signal is subjected to γ conversion as described above with reference to FIG. 11.

By performing the unevenness correction process as described above, the ejection energy generating element corresponding to the ejection port of the dense portion of the head lowers the driving energy (for example, the driving duty), and conversely, the ejection port of the thin portion is ejected. The corresponding ejection energy generating element raises driving energy. As a result, the print head density unevenness is corrected and a uniform image is obtained. However, if the density unevenness pattern of the head changes with use, the unevenness correction signal used becomes inadequate, and the unevenness in the image is caused. Occurs. In such a case, the nonuniformity correction data is rewritten.

HS conversion controller 51 in FIG.
0 and the conversion table memory 511 and FIG. 23 are described. In this example, the HS conversion table memory 5
09 is a ROM that stores each of the correction curves as shown in FIG. 24 in a table, and the unevenness correction RAM 717 can be a component of the HS conversion controller 510.

The HS conversion table memory 509 is set to R
ROM composed of rewritable memory such as AM and provided separately
It is also possible to appropriately read the table stored in the table etc. in accordance with the HS data (density unevenness correction data) calculation processing and expand it in the HS conversion table memory 509. In this case, as will be described later, when using independent density unevenness correction data for the upper and lower heads, the memory 50 is used.
The capacity of 9 may be the capacity corresponding to each of the HS corrections for the upper and lower heads, and the corresponding table may be rewritten prior to the HS correction for the upper and lower heads.

FIG. 25 shows an example of the unevenness correction processing procedure according to this example.

When this procedure is activated, first, step SP
At 1, an ejection stabilizing operation by head recovery / initialization is executed. This is because if the print head does not have normal ejection characteristics due to thickening of ink, mixing of dust or air bubbles, etc., if density unevenness correction processing is performed as it is, faithful head characteristics (density unevenness) This is because there is a risk that it may not be possible to recognize.

In the discharge stabilization process, the print head h and the cap, which is a component of the discharge recovery means 720, face and are joined to each other, and suction is performed through the cap to forcibly discharge the ink from the discharge port. You can Further, the ejection port forming surface may be cleaned by contacting the ejection port forming surface of the ink absorber that can be arranged in the cap unit, or by blowing air or wiping. It is also possible to drive the print head in the same manner as during normal printing to perform preliminary ejection. However, the driving energy at the time of preliminary ejection does not necessarily have to be the same as that at the time of printing. That is, the same processing as the so-called ejection recovery operation performed in the inkjet printing apparatus may be performed.

Note that, instead of or after the above-described processing, a pattern for stabilizing ejection can be printed on the test pattern print medium 213. Then, after that, a test pattern or the like for density unevenness correction may be printed.

Next, in steps SP3 and SP5,
The test pattern is printed and read, respectively. The manner of printing and reading in this example will be described.

FIG. 26 shows an example of the test image printing procedure (step SP3). In this procedure, first, step S
In P3-1, the carriages of the first and second printing units 11 and 11 'are moved to the test pattern (test image) printing position shown in FIG. 7, and then in step SP3-3.
It is determined whether the multi-scan mode as shown in FIGS. 18, 19, and 21 or the high-speed print mode as shown in FIG. 20 is set. When the multi-scan mode is set, it is further determined in step SP3-5 whether or not the unevenness correction data is independently set for each of the upper and lower heads in FIG.

When it is determined in step SP3-3 that the high speed mode is set, or in step S3.
If an affirmative decision is made in P3-5, step SP3-
7, the test pattern T1 as shown in FIG.
And T2 may be formed by two scans of the lower head and the upper head, respectively, and read in the R direction. In this case, in each subsequent test pattern, the predetermined area M from the center of each scan may be subjected to the unevenness correction calculation target. As a result, it is possible to cover the processing for all the ejection ports for each of the upper and lower heads, and it is possible to eliminate the instability of the read density at the image end portion that may occur when printing is performed by performing only one scan. . For this purpose, as disclosed in Japanese Patent Application No. 2-329746, before and after one scan performed by driving all the discharge ports, scans performed by driving the lower and upper several discharge ports are provided. The so-called irregular 3-line printing may be performed.

On the other hand, if a negative decision is made in step SP3-5, the operation proceeds to step SP3-9, for example, as shown in FIG.
Print a test pattern as shown in the upper and lower heads. Here, T1 'is a region for three scans printed by the lower head, T2' is a region for two scans overlapped by the upper head, and M'is a target region for unevenness correction calculation.

Referring again to FIG. 25, in steps S7 and S9, the averaging of the densities in the X direction and the allocating of the densities corresponding to the ejection ports are performed, respectively. As a method of assigning the density data obtained as described above to the ejection ports of the head, the following methods can be adopted. First, a threshold is determined so that a printed portion and a blank portion can be clearly distinguished from each other in the entire density distribution. Next, the center value of the coordinates having the density equal to or higher than the threshold value is obtained.
Then, the data for 64 ejection ports before and after that is obtained as the data of the unevenness correction calculation target, and in FIG. 27, the first half portion is made the density data for the lower ejection port group (the 65th to 128th ejection ports), The latter half is the upper outlet group (first
The density data for the 64th to 64th discharge ports may be used. In FIG. 28, the first half is the density data for the upper ejection port group for the lower head, the density data is for the lower ejection port group for the upper head, and the latter half is for the lower ejection port group for the lower head. And the upper head may be the density data for the upper ejection port group.

Based on the above, step SP1 of FIG.
In step 1, unevenness correction calculation is performed. That is, the signals for the number of ejection ports are sampled from the signals obtained by reading the density unevenness, and these are used as data corresponding to each ejection port as described above. When these R _1, R ₂ ... and R _{N (N} = 128), is once are stored in these RAM 219, CPU
At 102, the following calculation is performed.

These data are

[0131]

[Number 1] _{C n = -log (R n /} R 0) (R 0 is a constant becomes _{R 0 ≧ R n; 1 ≦} n ≦ N) is converted to become calculates subjected density signal.

Next,

[0133]

[Outside 2]

Is calculated.

Next, how much the density corresponding to each ejection port deviates from the average density is calculated as follows.

[0136]

## EQU2 ## ΔC _n = bar C / C _n Next, the signal correction amount (ΔS) _n according to (ΔC) _n is calculated.

[0137]

## EQU3 ## ΔS _n = A × ΔC _n .

Here, A is a coefficient determined by the gradation characteristics of the head.

Subsequently, a selection signal of the correction straight line to be selected is obtained according to ΔS _n , and the unevenness correction signal having 64 kinds of values of “0” to “63” is provided for the unevenness correction RAM 717 for the number of ejection ports.
(Steps SP13 and SP15). According to the unevenness correction data created in this manner, a γ correction curve (non-linear in FIG. 29A, linear in FIG. 29B) different for each ejection port is selected to correct density unevenness. To do so.

In the case shown in FIG. 27, the HS conversion data is obtained independently for the upper and lower heads. In this case, the capacity of the RAM 717 or the HS conversion table memory 509 is set to 2 heads for each color. In addition to the above, if the processing speed of the device such as the CPU 102A is high, the stored contents of the upper and lower heads may be rewritten.

In the case shown in FIG. 28, mixed density data obtained by performing overprinting on the upper ejection port group for the lower head and the lower ejection port group for the lower head, and the lower ejection port group for the lower head. And mixed density data obtained by performing overprinting on the upper ejection port group for the upper head. In this case, when determining the density unevenness correction data for each ejection port of the upper and lower heads from the density data obtained,
Overprinting is performed by the lower head, so 1/2 (average value) of the mixed concentration data is calculated,
The density unevenness correction data for the ejection port may be obtained from the value. Even if the test pattern is as shown in FIG. 27, the density data obtained from both patterns may be added and then averaged. In addition, if the characteristics of the upper and lower heads are different, the average value of the mixed concentration data is weighted or the mixed concentration data is distributed at an appropriate ratio as necessary, and the upper and lower heads are It is also possible to sort.

The above processing can be performed once for each color print head or repeated a plurality of times until the desired correction is performed. Further, it is possible not only to perform each color independently but also to perform a mixed color test pattern.

Further, it may be changed according to the print duty of the test pattern. That is, when it is desired to perform appropriate correction in various density areas, it is conceivable to print a test pattern with a print duty that provides the density and use the read result (eg, 20).
%, 40%, 60%, 80%, or it is also possible to take the average after printing with each duty).

The test pattern may be formed or corrected only when the print medium is a predetermined one, and this may be performed regardless of the type.
In this case, for example, it is possible to form, read, or correct a test pattern with an appropriate duty according to the type of print medium, and change the threshold according to the type of print medium.

Further, for example, step MS in FIG.
In 23, it is possible to determine the timing for executing this procedure according to various printing conditions.

In the above-described embodiment of the present invention, when one pixel is composed of a plurality of dots when at least the density inspection printing of the test pattern or the like is performed, the print duty, that is, the print setting is the number of constituent dots. This can be done by modulating the number of printed dots inside.

However, the print ratio can also be set by modulating the drive voltage and / or the drive pulse width or the number of ink drops per dot, and these can be set when one pixel is composed of one dot. It can also correspond to. That is, it goes without saying that the present invention can be applied regardless of what kind of modulation the print ratio is set to.

Further, the above-described embodiment of the present invention is an optimum embodiment in which the obtained correction processing is performed for each ejection energy generating element, but in practical use, the convergence state and processing time of the density uniformization processing are taken into consideration. Then, it is preferable to perform correction so as to give a common correction to predetermined adjacent plural ejection energy generating elements. The optimum configuration from this point of view is preferably configured such that the multiple ejection energy generating elements of the print head provide common correction for each block drive group in which a plurality of elements are collected. The block drive itself may be a known or publicly known one or a specific block drive method, but a drive condition that can carry out the corrected uniform density after determining the density unevenness of the present invention is given. It goes without saying that this is a prerequisite.

30 and 31, the image memory 505 in the case of performing independent head shading (HS) correction for the upper and lower heads and in the case of performing the HS correction by averaging the mixed density data, respectively. An example of the timing to drive the upper and lower heads without reading the data from is shown. When independent density unevenness correction is performed in the multi-scan mode, HS for each of the upper and lower heads is performed on the same image data, so that the same data is stored in the image memory 505 as shown in FIG. Is read twice, and data for thinning is generated for each of them, and then the head is driven at an appropriate timing corresponding to the position of the upper and lower heads in the sub-scanning direction. Further, when the mixed density data is averaged and a single HS data is used, as shown in FIG. 31, the image data read from the image memory 505 at the same time point is subjected to the HS conversion, and the upper and lower parts are converted. After the thinning data for the heads is generated, the upper and lower heads are driven at appropriate timings.

(4) Others The present invention is not limited to the ink jet method, and various printing methods can be adopted. When the ink jet printing method is adopted, it is used to eject ink among them. It is possible to provide an excellent effect in a print head and a printing apparatus of a system that includes means for generating heat energy as the generated energy (for example, an electrothermal converter or a laser beam) and causes a change in the ink state by the heat energy. is there. This is because such a method can achieve high density and high definition printing.

Regarding its typical structure and principle, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the print information and causing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling occurs on the heat acting surface of the print head. This is effective because bubbles can be generated in the liquid (ink) corresponding to this drive signal one-to-one as a result. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124, which is an invention relating to the temperature rise rate of the heat acting surface, are adopted, more excellent printing can be performed.

As the construction of the print head, in addition to the combination construction of the discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, The present invention also includes a configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which the heat acting portion is arranged in a bending region. In addition, for multiple electrothermal converters,
Japanese Unexamined Patent Publication No. 59-123670, which discloses a configuration in which a common slit is used as the discharge portion of the electrothermal converter, and Japanese Laid-Open Patent Publication No. 59-63, which discloses a structure in which an opening for absorbing a pressure wave of thermal energy is associated with the discharge portion. The effects of the present invention are effective even with a configuration based on Japanese Patent Laid-Open No. 138461. That is, according to the present invention, regardless of the form of the print head, printing can be surely performed efficiently.

Furthermore, the present invention can be effectively applied to a full line type print head having a length corresponding to the maximum width of a print medium which can be printed by the printing apparatus. As such a print head, a configuration that satisfies the length by a combination of a plurality of print heads,
It may be configured as one print head integrally formed.

In addition, even in the case of the serial type as in the above example, the print head fixed to the apparatus main body or the electrical connection with the apparatus main body or the ink from the apparatus main body by being attached to the apparatus main body The present invention is also effective when a replaceable chip type print head that can be supplied or a cartridge type print head in which an ink tank is integrally provided in the print head itself is used.

Further, as the constitution of the printing apparatus of the present invention, it is preferable to add the ejection recovery means of the print head, the preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suctioning means for the print head, preheating means for heating using an electrothermal converter or another heating element or a combination thereof, and printing Preliminary ejection means for performing another ejection can be mentioned.

Regarding the type and number of print heads to be mounted, for example, a plurality of heads are provided corresponding to a single color ink, and a plurality of inks having different print colors and densities are supported. And a plurality of them may be provided. That is, for example, the print mode of the printing apparatus is not limited to the print mode of only the mainstream color such as black, but may be either the print head is integrally configured or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color print modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet method, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, the ink is liquefied by applying heat energy according to the print signal,
The present invention is also applicable to the case of using an ink that has a property of being liquefied only when heat energy is applied, such as one that ejects a liquid ink or one that already begins to solidify when it reaches a print medium. The ink in such a case is in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, it may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the ink jet printing apparatus of the present invention, other than the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function are provided. It may be a form or the like.

[0159]

As described above, according to the present invention,
For example, one test image is formed by a plurality of print heads provided for a printing agent having the same color tone, and the density data obtained by reading this is averaged by the number of heads,
By commonly correcting the drive signals of the plurality of print heads based on the average value, it is possible to efficiently perform the density unevenness correction processing of the heads when performing overlapping printing using the plurality of print heads.

Further, means for forming a test image separately for each of the plurality of print heads, and for each of the plurality of print heads based on the respective density data obtained by reading the test image. By further comprising a means for correcting the drive signal and performing different density unevenness correction during non-overlapping printing, it is possible to perform appropriate correction according to the print mode.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing an outline of a printing processing procedure.

FIG. 3 is a block diagram showing a system focusing on the configuration of a host computer according to an embodiment of the present invention.

FIG. 4 is a side sectional view showing an outline of a mechanical configuration of a printer applied to this embodiment.

FIG. 5 is a perspective view showing a configuration example around the print head.

FIG. 6 is an explanatory diagram of a speed of a carriage which carries the print head and is scanned.

FIG. 7 is a schematic perspective view showing a schematic configuration of a density unevenness reading unit applicable to the printer of this embodiment.

8 is a block diagram showing an electrical schematic configuration of the printer shown in FIG.

FIG. 9 is a block diagram of the same.

FIG. 10 is a block diagram showing a part of the internal configuration of the control board in FIG. 8 focusing on the flow of data.

FIG. 11 is a block diagram of the same.

FIG. 12 is a block diagram of the same.

13 is an explanatory diagram showing an example of data developed in a palette conversion table memory in FIG.

FIG. 14 is an explanatory diagram for explaining data set in each memory shown in FIG. 11 in order to prevent abnormal output until a conversion parameter is input.

FIG. 15 is an explanatory diagram for explaining pixel formation for a print image.

16 is an explanatory diagram for explaining data thinning-out for FIG. 15. FIG.

FIG. 17 is an explanatory diagram similarly.

FIG. 18 is an explanatory diagram for explaining an example of a printing method by the printer of FIG.

FIG. 19 is also an explanatory diagram.

FIG. 20 is an explanatory diagram similarly.

FIG. 21 is also an explanatory diagram.

FIGS. 22A and 22B are explanatory diagrams of a mode of unevenness correction of the print head.

FIG. 23 is a block diagram showing a configuration example of a control system according to the present embodiment.

FIG. 24 is an explanatory diagram illustrating an unevenness correction table used in this example.

FIG. 25 is a flowchart showing an example of the unevenness correction processing procedure according to the embodiment.

FIG. 26 is a flowchart showing a detailed example of the test image forming process.

FIG. 27 is an explanatory diagram showing an example of a test image used for independently performing HS conversion on two heads.

FIG. 28 is an explanatory diagram showing an example of a test image used for commonly performing HS conversion on two heads.

29 (A) and 29 (B) are explanatory diagrams showing two examples of correction curves used for HS-γ conversion.

FIG. 30 is a timing chart showing an example of timings from image data reading or head driving when driving two heads from two HS data.

FIG. 31 is a timing chart showing an example of the timing from image data reading to head driving when driving two heads from one HS data.

[Explanation of symbols]

H host computer 1011 CPU 1016 LAN 1018, 1019 External storage 1023 keyboard 1024 mouse 1026 CRT P printer 3 print media (cloth) 102 control board 102A CPU 102B ROM 102C RAM 104 cloth feeder 108 Head characteristic measuring machine 213 Test pattern print media 217 Mura reading line sensor 218 light source 219 RAM 236 A / D converter 501 GPIB interface 504 frame memory (FM) controller 505 image memory 509 Palette conversion table memory 511 HS conversion table memory 513 γ conversion table memory 515 connecting memory 717 unevenness correction RAM

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-8571 (JP, A) JP-A-1-99871 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/05 B41J 2/01 B41J 29/46

Claims (24)

(57) [Claims] [Claim 1] with a plurality of print heads in which a plurality of printing elements each for the same color of the print agent, in the image output apparatus that outputs an image by printing an image on a print medium, the same image data Pixels printed according to
While allocating to each print head,
It previous SL plurality of print heads based on serial image data
By overprinted images to be printed are distributed to, respectively on the print medium, the superposed printing means for printing an image corresponding to the image data, and means for forming a test image by the plurality of print heads, formed The print elements of the plurality of print heads corresponding to the same print position in printing of the image by the overlay printing unit are common to the print elements of the plurality of print heads, based on the result of reading the density unevenness in the array of the print elements of the printed test image. Correction data creating means for creating correction data used for the above, and correction means for correcting image data input from the outside in accordance with print elements of the plurality of print heads for printing the image data by the overlay printing means. And is equipped with Image output device. Wherein said test image is printed medium by the superimposed printing means using the plurality of print heads
The image output device according to claim 1, wherein the image output device is one test image printed on the body in an overlapping manner . Wherein said correction data generation means, the density data obtained by reading the concentration of the one of the test image is averaged by the number of said plurality of print heads, and the averaged
The image output apparatus according to claim 2, wherein the correction data is created based on the calculated value . 4. A means for individually forming a test image on each of the plurality of print heads, and a test formed by each of the plurality of print heads.
From the result of scanning density unevenness for each
Density unevenness correction corresponding to each print head
4. The image output device according to claim 1, further comprising head-specific correction data creating means for creating data . 5. The image output apparatus according to claim 4, wherein when the drive signal is corrected for each of the plurality of print heads, the processing is performed in a time division manner. 6. The plurality of print heads are arranged along a conveyance direction of a print medium, and the overlapping print means is provided.
To print by stacking multiple print heads
And overlapping print operation of said plurality of Purintoheddoso
Non-overlapping printing operation in which the respective prints are performed without overlapping is possible, and when performing the overprinting, the correction data created by the correction data creating means is performed.
Performs correction by chromatography data, wherein when performing non-overlap printing is created by the head specific correction data creating means
The correction data can be used to correct each of the multiple printheads.
The image output apparatus according to claim 4 or 5, wherein the image output apparatus is configured to perform . 7. The test image is the plurality of prints.
Without overlapping the test image formed by each head
The correction data creating means is configured to form the plurality of print heads.
Individually read multiple test images created by each
Based on the concentration data obtained,
The same print position when printing images by
The print head of each of the plurality of print heads.
To create correction data that is commonly used for lint elements.
The image output device according to claim 1, which is characterized in that. 8. The correction data creating means includes a plurality of the correction data creating means.
Multiple test images created by each printhead
Add the density data obtained by reading the images individually.
The correction data is created based on
The image output device according to claim 7. 9. An image is output by two or more printing agents having different color tones, and the plurality of print heads are used for each of the two or more printing agents having different color tones. the image output apparatus according to any one of claims 1 to 8. Wherein said print head, the image according to claim 1 of <br/> stone 9, wherein the ink used as the printing agent is an ink jet print head for ejecting the ink Output device. 11. The image output apparatus according to claim 6 , and image data relating to printing are supplied to the image output apparatus, and instructions are given to perform the overlap printing operation or the non-overlap printing operation. An image forming system comprising an image supply device. 12. Pixels printed according to the same image data by using a plurality of print heads in which a plurality of printing elements are arranged for printing agents of the same color tone.
To the print heads
Moni performs overlapping printing operation to print an image corresponding to the image data by printing overlapping the image to be printed are distributed to each front Symbol plurality of print heads on the print medium based on the image data, print In an image output method for outputting an image to a medium, a step of forming a test image by the plurality of print heads, and based on a result of reading density unevenness in the array of the print elements of the formed test image, The correction data creation step of creating correction data commonly used by the print elements of the plurality of print heads corresponding to the same print position in the image printing by the overlapping print operation, and the image data input from the outside Image data can be printed by the overlay printing operation. A correction step of correcting the print elements of the plurality of print heads corresponding to each of the plurality of print heads, and printing is performed by the overlay printing operation based on the image data corrected by the correction step. Image output method. Wherein said test image is printed by the overlapped printing operation using the plurality of print heads
13. The image output method according to claim 12 , wherein the test image is one test image printed on the medium in an overlapping manner. 14. The correction data creating step averages the density data obtained by reading the density of the one test image by the number of the plurality of print heads, and performs the averaging.
The image output method according to claim 13 , wherein the correction data is created based on the value . 15. The test image includes the plurality of print images.
Without overlapping the test images formed by each
The correction data creating step is performed on the plurality of print heads.
Individually read multiple test images created by each
Based on the concentration data obtained,
The same print position when printing images by
The print head of each of the plurality of print heads.
To create correction data that is commonly used for lint elements.
The image output method according to claim 12, characterized in that 16. The correction data creating step includes:
Multiple tests formed by each printhead
The density data obtained by reading each image individually was added.
It is characterized in that the correction data is created based on
The image output method according to claim 15. 17. Pixels printed according to the same image data by using a plurality of print heads in which a plurality of print elements are arranged for printing agents of the same color tone.
To the print heads
Moni performs overlapping printing operation to print an image corresponding to the image data by printing overlapping the image to be printed are distributed to each front Symbol plurality of print heads on the print medium based on the image data, print In an image output method for outputting an image to a medium, a step of determining whether a common correction or a different correction is performed on the plurality of print heads, and the plurality of print heads are determined by the determination step. When it is determined that the common correction is applied to the plurality of print heads, a test image is formed by the plurality of print heads, the test image is read, and the plurality of prints at the time of outputting the image based on the result of the reading. A step of commonly correcting the drive signals of the heads; When it is determined that the correction is performed, a test image is formed separately by the plurality of print heads, the test image is read, and the test image is read based on the respective density data obtained by reading the test image. An image output method comprising: a step of individually correcting drive signals for a plurality of print heads. 18. The image output method according to claim 17 , wherein when the drive signal is corrected for each of the plurality of print heads, the processing is performed in a time division manner. 19. The print head is arranged in the conveying direction of the print medium, the overlapped printing operation onto the printing medium using the plurality of print heads, or the printing by each of the plurality of print heads
When non-overlapping print operation for printing without overlapping is possible, and when it is determined in the determination step that the overprint printing operation is performed, the common correction is performed, and it is determined that the nonoverlap printing operation is performed. the image output method according to claim 17 or 18 wherein, characterized in that each separate correction is performed. 20. An image is output by two or more printing agents having different color tones, and the plurality of print heads are used for each of the two or more printing agents having different color tones. Claim 12 or
20. The image output method according to any one of 19 . 21. The printhead according to claim wherein the ink used as the printing agent is an ink jet print head for ejecting the ink 12
21. The image output method according to any one of 20 to 20 . 22. The method of claim, characterized in that the ink comprises further a step of fixing the printing medium after the to image output applying an ink to the print medium 12
22. The image output method according to any one of 21 to 21 . 23. After the step of fixing the ink,
23. The image output method according to claim 22 , further comprising a step of cleaning the printed print medium. 24. according to any one of claims 12 to 23, characterized in that further comprising a pretreatment step to incorporate a pretreatment agent to said printing medium before printing by ejection of ink from said printhead Image output method.