Ink-jet printed products producing apparatus and ink-jet printed products produced by the apparatus

Ink bottles containing inks having the same tone and different compositions adapted to respective kinds of fibers for a cloth are provided. Printing heads are provided corresponding to respective inks for performing printing.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to an ink-jet printing apparatus and a 
printing method for performing printing by ejecting an ink to a printing 
medium, such as cloth and so forth, and printed products obtained through 
ink-jet printing. 
Throughout this specification, the wording "print" should be appreciated to 
include "textile printing". Furthermore, in the specification, "coloring 
matter is fixed on a printing medium" includes coloring of the printing 
medium employing the coloring matter in the extent that substantially no 
washing-out of the color is caused. Also, "tone" means "color" and 
"density". Accordingly, "same tone" means substantially the same color and 
the same density. 
2. Description of the Related Art 
As typical conventional textile printing apparatus for performing printing 
on cloth, there have been known apparatus employing a roller printing 
method of forming a sequential pattern on a cloth by depressing a roller 
on which a pattern is carved onto the cloth, or employing screen printing 
method preparing plates in a screen form and using the screen plates 
corresponding to number of colors and patterns to be overlaid so as to 
perform printing directly on the cloth or so forth. 
However, in the textile printing apparatus employing the roller printing 
method or screen printing method, large number of process steps and days 
in preparation of the roller or the screen are required. In addition, 
these textile printing apparatuses require operations for blending of 
various colors of inks for color matching and positioning of the roller or 
the screen plates. Furthermore, the apparatus per se is relatively large 
and becomes larger when to increasing of number of colors to be used, and 
therefore requires a relatively wide space for installation. Furthermore, 
an additional space is further required for storing the rollers and screen 
plates. 
On the other hand, as a recording apparatus to be employed in a printer, 
copy machine, facsimile and so forth, or as a recording apparatus to be 
employed as an information output apparatus in composite electronic 
apparatus including computers, word processors and so forth or work 
stations, an ink-jet type printing apparatus has been put into practical 
use. In Japanese Patent Application Publication No. 62-57750 and Japanese 
Patent Application Publication No. 63-31594, there has been proposed to 
employ such ink-jet type recording apparatus for the textile printing and 
to perform printing by ejecting ink directly on the cloths. 
The ink-jet type recording apparatus performs recording by ejecting ink 
toward a printing medium from a recording head, and holds many advantages 
that the recording head can be easily down-sized, a fine image can be 
recorded at high speed, a cost for running the apparatus is relatively 
small, running noises of the apparatus are small, and a color image using 
a plurality of color inks can be easily recorded. 
Particularly, a bubble-jet type recording head which ejects ink utilizing 
thermal energy, can be produced by employing a semiconductor fabricating 
process, such as etching, deposition, sputtering and so forth. In such 
case, electrothermal transducing elements, electrodes and so forth are 
formed on a substrate, also liquid passage walls and a ceiling plate and 
so forth are formed on the substrate. Therefore, the recording head 
permits high density arrangement of liquid passages and ejection orifices, 
and can be easily down-sized. 
However, if the ink-jet printing apparatus is applied for the textile 
printing by simply replacing the printing medium with cloth, it may be 
readily expected to cause new technical problems. 
For example, the following problems have been known. The cloth as generally 
referred to includes variety of materials including natural fibers, such 
as cotton, silk, wool and so forth and synthetic fibers, such as nylon, 
polyester, acryl and so forth. Naturally, different fibers have different 
characteristics in textile printing. The characteristics of various fibers 
have been discussed in detail in "Dyeing", directed by Kazuo Kondo, 
Denki-Dai Shuppankyoku and "Materials and Products of Apparel", Bunka 
Fukuso Gakuin, Bunka Shuppankyoku. 
Dyeing property of dyes and fibers are in the relationship shown in the 
following table 1. As can be seen from the table, the dyeing properties of 
each fiber are differentiated depending upon the dye to be used. When a 
cloth is woven with a plurality of kinds of fibers having the same or 
similar dyeing property, one kind of ink (dye), to which a plurality of 
kinds of fibers have a common dyeing property, can be used. However, in 
the case where the cloth is woven with a plurality of kinds of fibers 
having different dyeing properties, such as blended fiber cloth of nylon 
and cotton, for example, it is desirable to use different inks 
respectively adapted to respective of the different kinds of fibers. As a 
construction to use inks respectively corresponding to respective fibers, 
it can considered to use one kind of ink until the printing amount reaches 
a predetermined amount with exchanging inks to repeated the printing 
process. However, in the case of using above-described construction, it is 
relatively difficult to maintain the accuracy of positioning relationship 
between a recording head and a cloth, an operation for maintaining the 
accurate positioning is complicated and thus there is a problem that it is 
impossible to utilize the advantages of the ink-jet textile printing. 
__________________________________________________________________________ 
Dyeing property of Dye and Fiber 
Dye 
Metal 
Basic 
Acid 
Fiber 
Direct 
Acid 
Complex 
(Cation) 
Mordant 
Vat 
Sulphur 
Naphthol 
Disperse 
Reactive 
Pigment 
__________________________________________________________________________ 
Cotton, 
.DELTA. .largecircle. 
.largecircle. 
.largecircle. 
.largecircle. 
.largecircle. 
Hemp, 
Rayon 
Wool, 
.DELTA. 
.largecircle. 
.largecircle. 
.DELTA. 
.largecircle. .DELTA. 
.DELTA. 
Silk 
Acetate .DELTA. .DELTA. 
.DELTA. 
.largecircle. 
.DELTA. 
Nylon 
.DELTA. 
.largecircle. 
.largecircle. 
.DELTA. 
.largecircle. 
.DELTA. 
.DELTA. 
.DELTA. 
.DELTA. 
Polyester .largecircle. 
.DELTA. 
Acryl .DELTA. 
.DELTA. 
.largecircle. .DELTA. .DELTA. 
Vinal 
.DELTA. .DELTA. .DELTA. 
.DELTA. 
.largecircle. 
.DELTA. .DELTA. 
fiber 
__________________________________________________________________________ 
.largecircle.: Good dyeing property 
.DELTA.: Dyeing is possible 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an ink-jet printed 
products producing apparatus which can easily and surely perform high 
quality printing for cloths woven with a plurality of fibers having 
mutually different dyeing properties. 
According to a first aspect of the present invention, there is provided an 
ink-jet printed product producing apparatus employing a plurality of 
ink-jet heads ejecting inks of respectively the same tone and different 
composition and performing printing by ejecting inks from the plurality of 
ink-jet heads to a printing medium, the apparatus comprising: 
means for providing the plurality of ink-jet heads for using at different 
printing steps from each other for printing on the printing medium. 
According to a second aspect of the present invention, there is provided an 
ink-jet printed product producing apparatus employing a plurality of 
ink-jet heads ejecting inks of respectively the same tone and different 
composition and performing printing by ejecting inks from the plurality of 
ink-jet heads to a printing medium containing a plurality of kinds of 
fibers, the apparatus comprising: 
control means for varying ejection ratio of inks to the printing medium 
through the ink-jet head depending upon ratio of content of the plurality 
of fibers. 
According to a third aspect of the present invention, there is provided an 
ink-jet printed product producing apparatus employing a plurality of 
ink-jet heads ejecting inks of respectively the same tone and different 
composition and performing printing by ejecting inks from the plurality of 
ink-jet heads to a printing medium, the apparatus comprising: 
means for determining order of ejection of the plurality of ink-jet heads 
in printing depending upon a difference of dyes. 
According to a fourth aspect of the present invention, there is provided an 
ink-jet printed product producing apparatus employing a plurality of 
ink-jet heads ejecting inks of respectively the same tone and different 
composition and performing printing by ejecting inks from the plurality of 
ink-jet heads to a printing medium, the apparatus comprising: 
print control means for making inks ejected from the plurality of ink-jet 
heads to shoot onto substantially the same position on the printing 
medium. 
According to a fifth aspect of the present invention, there is provided an 
ink-jet printed product producing apparatus employing a plurality of 
ink-jet heads ejecting inks of respectively the same tone and different 
composition and performing printing by ejecting inks from the plurality of 
ink-jet heads to a printing medium, the apparatus comprising: 
feeding means for feeding the printing medium; 
scanning means for arranging the plurality of ink-jet heads in the feeding 
direction of the printing medium fed by the feeding means and for 
operating the plurality of ink-jet heads for scanning in a direction 
different from the feeding direction; and 
control means for controlling feeding of the feeding means and scanning by 
the scanning means and thus overlaying printing region by respective ones 
of the plurality of ink-jet heads. 
According to a sixth aspect of the present invention, there is provided a 
producing method of an ink-jet printed product of performing printing by 
ejecting ink onto a printing medium, the method comprising the steps of: 
providing a plurality of ink-jet heads respectively ejecting inks of the 
same tone and different composition; and 
performing printing steps employing respective ones of the plurality of 
ink-jet heads with a given interval between the printing steps. 
The above and other objects, effects, features and advantages of the 
present invention will become more apparent from the following description 
of embodiments thereof taken in conjunction with the accompanying drawings 
.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will be discussed hereinafter in detail with 
reference to the accompanying drawings. In the following description, 
numerous specific details are set forth in order to provide a thorough 
understanding of the present invention. It will be obvious, however, to 
those skilled in the art that the present invention may be practiced 
without these specific details. In other instances, well-known structures 
are not shown in detail in order to unnecessarily obscure the present 
invention. 
It should be noted that while the following detailed description is 
directed to an application of the present invention to an ink-jet printing 
apparatus serving as a textile printing apparatus, the ink-jet printing 
apparatus according to the present invention is, of course, applicable for 
various other applications, such as printing apparatus and so forth. 
(First Embodiment) 
FIG. 1 shows an example of an ink-jet printing apparatus as the first 
embodiment of a textile printing apparatus according to the present 
invention, and FIG. 2 is an enlarged perspective view showing the major 
part of the ink-jet printing apparatus of FIG. 1. The shown embodiment of 
the textile printing apparatus generally comprises a cloth feeding portion 
B for feeding a cloth on a roll, which is processed for preparation for 
textile printing, a main body portion A performing printing with an ink 
ejected from an ink-jet head with precise line-feeding for the fed cloth, 
and a winding portion C drying and winding the printed cloth. The main 
body portion A comprises a precise line feeding portion A-1 including a 
platen and a printing unit A-2. 
A processed cloth 3 in a form of roll is supplied to the cloth 3 feeding 
portion B. Then, the cloth is fed to the main body portion A in stepping 
manner. 
The cloth 3 fed in stepping manner is restricted to flatten a printing 
surface by a platen 12 in a first printing portion 11. To this printing 
surface, ink is ejected from the ink-jet head 13 on scanning in 
perpendicular direction with respect to the plane of the drawing, for 
performing printing for one line. After completion of printing for one 
line, the cloth is set for a predetermined stepping amount (line-feeding 
amount). The printed portion of the cloth is subsequently heated from the 
back side thereof by a heating plate 14 and dried by hot air supplied from 
the surface side thereof and ventilated, by a hot air duct 15. 
Subsequently, in a second printing portion 11', overlaying printing is 
performed for the portion printed by the first printing portion 11 in the 
same process to the first printing portion. 
In the construction set forth above, when printing is to be performed for a 
blended fiber cloth of cotton and polyester, for example, inks to be 
ejected from the head 13' arranged at the upper portion in FIG. 1 and from 
the head 13 arranged at the lower portion have the same tone but mutually 
different compositions. Namely, the head 13' ejects the ink containing 
reactive dye having good dyeing property to cotton, and the head 13 ejects 
the ink containing disperse dye having good dyeing property to polyester. 
In addition, in the overlaying printing by using the ink-jet heads 13 and 
13', each ink droplet ejected from the heads 13 and 13' for printing a 
same pixel is shot onto substantially the same point on the cloth 3. 
As set forth above, by performing printing with inks having good dyeing 
property to correspond to respective fibers forming the cloth, sufficient 
dyeing can be performed for respective fiber resulting in high quality 
printing. 
The cloth completed printing in the first and second printing portions 11 
and 11' is again dried by post drying portion 16 similar to the heating 
plate 14 and the duct 15 set forth above, guided by a guide roller 17 and 
then wound on a winding roll 18. The cloth thus wound on the winding roll 
is removed from the shown apparatus. Then, the cloth is subject color 
development, washing and drying processes by batch process to become the 
product. 
In FIG. 2, the cloth 3 as the printing medium is fed in stepping manner 
upwardly in the drawing. In the first printing portion 11 at the lower 
side in the drawing, a first carriage 24 mounting ink-jet heads for 
ejecting ink of the colors yellow (Y), magenta(M), cyan (C), black (BK) 
and special colors S1 to S4, namely eight ink-jet heads 13Y, 13M, 13C, 
13BK, 13S1 to 13S4, and movable in the direction shown by arrow, is 
provided. The ink-jet head in the shown embodiment has element for 
generating thermal energy for causing film boiling in ink as energy to be 
utilized for ejecting ink. A plurality of elements are arranged 
corresponding to 256 ejection orifices arranged at a density of 400 DPI. 
At the downstream side (upper side in the drawing) in the cloth feeding 
direction, of the first printing portion, a drying portion 25 is provided. 
The drying portion 25 includes the heating plate 14 for drying the cloth 3 
from the backside thereof and the hot air duct 15 for drying the cloth 
from the surface side. The heat transmission surface of the heating plate 
14 strongly heats the cloth from the back side with high temperature and 
high pressure vapor passing through hollow interior thereof. A plurality 
of fins 14' are provided on the inner side of the heating plate 14 for 
collecting heat so that the heat may be efficiently concentrated on the 
back side of the cloth 3. The heating plate 14 is covered with a heat 
insulating material 26 at the opposite side to the side mating with the 
cloth 3 so as to avoid loss of heat by radiation. 
At the surface side of the cloth 3, as a dry hot air is blown thereonto by 
the hot air supply duct 27 so as to enhance effect of drying by blowing 
air at lower temperature than the heat provided by the heat plate, drying 
of the cloth is promoted. Also, air containing sufficient moisture and 
flowing in the opposite direction to the cloth feeding direction, is drawn 
in a much greater amount than blowing amount by the upstream side drawing 
duct 28 so that evaporated water vapor may not cause leakage to cause dew 
drops on the peripheral machine devices. A supply source of the hot air is 
placed at the back side in FIG. 2, and, on the other hand, drawing of the 
hot air is performed from the front side, so that the pressure difference 
between the pressures at a blowing opening 29 and a drawing opening 30 can 
be uniform at overall area in the longitudinal direction. The air blowing 
and drawing portion is offset to the downstream side with respect to the 
center of the heating plate 14 at the back side of the cloth so that the 
air may be blown onto the portion sufficiently heated. By this, a large 
amount of water including a reducer contained in ink received in the cloth 
can be strongly dried. 
Furthermore, at the downstream side, there is provided the second printing 
portion 11' which is formed with eight ink-jet heads 13Y', 13M', 13C', 
13BK' and 13S1' to 13S4' and a second carriage 24' mounting these ink-jet 
heads, similarly to the first carriage. It should be appreciated that the 
first carriage 24 and the second carriage 24' may be preliminarily 
integrated or integrated with an appropriate coupling member so as to make 
the driving power source and power transmission mechanism in common to 
each other. 
Also, though it is not illustrated in FIGS. 1 and 2, an ink supply device 
for storing ink and supplying necessary amount of ink to the head is 
provided. The ink supply device includes an ink tank, an ink pump and so 
forth as known in the art. A main body of the ink supply device is 
connected to the head through an ink supply tube and so forth. Typically, 
by capillary effect, an amount of ink corresponding to the amount ejected 
through the head is automatically supplied to the head. On the other hand, 
in an ejection recovery operation, ink is forcedly supplied to the head by 
means of the ink pump. The head and the ink supply device are mounted on 
different carriages for reciprocation in the direction shown by the arrow 
by a not shown driving device. 
Also, while it is not illustrated in FIGS. 1 and 2, it is possible to 
provide a head recovery device at a position to mate with the head at a 
home position (retracted position) for maintaining ejection stability of 
ink by the head. The head recovery device may perform the following 
operation. Namely, in order to avoid vaporization of ink from the ejection 
orifice of the head in inoperative state, capping for the head is 
performed at the home position. Also, a collection operation is performed 
when in order to remove bubble and/or dust at the ejection orifice before 
initiation of image recording, ink path in the head is pressurized by 
means of the ink pump for forcedly discharging ink through the ejection 
orifice (pressurizing recovery operation), or ink is forcedly drawn from 
the ejection orifice to discharge by a negative pressure (suction recovery 
operation). 
Description will be given for a control system of the shown embodiment of 
the apparatus. FIGS. 3 and 4 show an example of a control system for the 
shown embodiment of the textile printing apparatus and its operating 
portion. FIGS. 5 to 7 conceptually illustrate internal construction of a 
control board 102 of FIG. 3 in terms of flow of data. 
From a host computer H, a printing image data is transmitted to a control 
board 102 via an interface (here, GPIB). In addition to this, a color 
pallet data and so forth determining mixing ratios of Y, M, C or special 
colors for precisely reproducing colors selected by a designer, is 
transmitted to the control board 102. For the construction of this, the 
system disclosed in commonly assigned Japanese Patent Application 
Laying-open No. 6-91998 may be employed. 
The device for transmitting the image data is not specified. Also, 
transmission of the image data may be performed in various manners such as 
on-line transmission through a network, off-line transmission via a 
magnetic tape or other data recording medium, or so forth. A control board 
102 comprises CPU 102A, ROM 102B storing various programs, RAM 102C having 
various register regions and working regions and other portions 
illustrated in FIGS. 5 to 7 and performs control for overall apparatus. 
The reference numeral 103 denotes an operation and display portion 
including an operating portion for providing necessary command for the 
textile printing apparatus by an operator, and a display portion for 
displaying messages and so forth to the operator. A reference numeral 104 
denotes a cloth feeder comprising a motor and so forth for feeding the 
printing medium, such as cloth, fabric or so forth as an object to be 
printed. A reference numeral 105 denotes a driver unit input/output 
portion for driving various motors (labeled with "M" at the end) and 
various solenoids (labeled as "SOL") shown in FIG. 4. A reference numeral 
107 denotes a transfer board receiving information associated with 
respective head (information of presence or absence of the head and/or 
color to be printed by the head) and supplying this information to the 
control board 102. The information from the transfer board 107 is 
transferred to the host computer H and to demand transfer of the color 
pallet of the color to be used. Also, the information is used for 
recognition of a mounting range of the heads to the carriage 24 and 24' 
and for setting scanning range and so forth. Reference numeral 111 denotes 
a driving portion, such as motor, for driving the carriages 24 and 24' for 
scanning. 
When the image data to be printed is received from the host computer H, the 
control board 102 accumulates the image data in an image memory 505 via a 
GPIB interface 501 and a frame memory controller 504 (see FIG. 5). In the 
shown embodiment, the image memory 505 has 124 Mbyte of capacity for 
storing 8-bit pallet data for A1 size image data. Namely, 8 bits are 
assigned for each pixel. A reference numeral 503 denotes a DMA controller 
for high speed memory transfer. When image data transfer from the host 
computer H is completed, the control board 102 performs predetermined 
process and then initiates printing. 
Here, the host computer H connected to the shown embodiment of the textile 
printing apparatus transfers the image data as raster image data. On the 
other hand, for a plurality of ink ejection orifices arranged in 
longitudinal direction of the head, data in the direction perpendicular to 
the arranging direction of the raster image data is assigned, 
respectively. Therefore, the arrangement of the image data has to be 
transformed into that consistent with the arrangement of the printing 
heads. This data transformation is performed by a raster-@-BJ 
transformation controller 506. The data transformed by the raster-@-BJ 
transformation controller 506 is transferred to a pallet conversion 
controller 508 via an up-scaling function of a next stage up-scaling 
controller 507 for varying the scale of the image data. It should be 
appreciated that the data up to the up-scaling controller 507 is the 
identical data to the data transmitted from the host computer, and thus to 
the 8-bit pallet signal in the shown embodiment. The pallet data (8 bits) 
is commonly transferred to processing portions (discussed later) for 
respective printing heads. 
The following description will be given in terms of the embodiment 
including heads or printing yellow, magenta, cyan, black and other special 
colors S1 to S4. 
In FIGS. 6A and 6B, the pallet conversion controller 508 supplies the 
pallet data input from the host computer H and a conversion table for the 
corresponding color to a conversion table memory 509. 
In case of 8-bit pallet data, colors to be reproduced are 256 kinds of 0 to 
255. Appropriate tables are developed in the table memory 509 
corresponding to respective colors. For example, the following 
relationship is set in a table: 
______________________________________ 
when 0 is input light gray is printed 
when 1 is input special color 1 is printed 
when 2 is input special color 2 is printed 
when 3 is input blue type color as blended color 
of cyan and magenta is printed 
when 3 is input cyan is printed 
when 5 is input red type color as blended color 
of magenta and yellow is printed 
. . 
. . 
. . 
when 254 is input 
yellow is printed 
when 255 is input 
not print 
______________________________________ 
As a concrete circuit construction, the pallet conversion table 509 
performs function by writing conversion data at address corresponding to 
the pallet data. Namely, in practice, when the pallet data is supplied as 
address, memory access is performed in read mode. The pallet conversion 
controller 508 performs management of the pallet conversion table memory 
509 and interfacing between the control board 102 and the pallet 
conversion table memory 509. Also, concerning the special colors, a 
circuit for setting a blending amount of the special color (a circuit for 
multiplying an output for 0 to 1 times) may be disposed between HS system 
comprising the next stage HS controller 510 and HS conversion table memory 
511 to make the set value variable. 
The HS controller 510 and the HS conversion table memory 511 perform 
correction of fluctuation of printing density corresponding to each 
ejection orifice of each head on the basis of a data measured by a head 
characteristics measuring device 108 (see FIG. 3) including a correcting 
portion for correcting unevenness of density. For instance, the process 
for the ejection orifice having the characteristics to have small ejecting 
or expelling amount, and thus to have low printing density, the data is 
converted into high density data, for the ejection orifice having the 
characteristics to have large ejecting amount, the data is converted into 
lower density data, and for the ejecting orifice having the 
characteristics to have medium ejecting amount, the data is maintained 
without conversion, is performed. This process will be discussed later. 
A .gamma. conversion controller 512 and a .gamma. conversion table memory 
513 in the next stage, performs table conversion for increasing and 
decreasing overall density per each color, For example, if no conversion 
is effected, the table becomes linear as follows: 
______________________________________ 
for input 0 output 0 
for input 100 output 100 
for input 210 output 210 
for input 255 output 255 
______________________________________ 
A binarization controller 514 has a pseudo-tone function to input 8-bit 
tone data and output binarized one-bit pseudo tone data. As a method for 
converting many-valued data into binary data, there are methods employing 
dither matrix, an error dispersing method and so forth. The shown 
embodiment may employ any one of such methods, and detailed description 
therefor is omitted. Nevertheless, any method which may express the tone 
with number of dots in the unit area may be utilized. 
The binarized data is once stored in a transfer memory 515 and then used 
for driving each color of ink-jet head. Namely, the binary data is output 
from respective transfer memory for each ink of C, M, Y, BK, S1 to S4. 
Since the binary signal for each color is processed in the same manner, 
the following description will be given with respect to the binary data of 
cyan (C) with reference to FIG. 7. FIG. 7 shows the construction for cyan 
of the printing color. The same construction is employed for each color. 
Also, FIG. 7 shows a circuit construction subsequent to the transfer 
memory 515. 
The binarized signal C is output toward a sequential multi-scan generator 
522 (hereinafter referred to as SMS generator). However, since test 
printing on the basis of predetermined pattern data from binary value PG 
controller forming a pattern generator 517 and EPROM 518, the pattern data 
and the binarized signal C are supplied to a selector 519 for selecting 
one of the pattern data and the signal C. Switching of selection in the 
selector 519 is controlled by CPU of the control board 102, when the 
operator performs predetermined operation in the operating portion 103 
(see FIG. 3), the data from the binary value PG controller 517 is selected 
to perform test printing. Therefore, the selector 519 usually selects the 
data from the transfer memory 515. A reference numeral 520 denotes a logo 
input portion disposed between the selector 519 and the SMS generator 522. 
In the logo input portion 520, in case of the textile printing, logo mark 
data for maker's brand or designer's brand and so forth is input. The 
construction of the logo input portion may include a memory for storing 
the logo mark data and a controller for managing the printing position of 
the logo mark, and so forth. 
The SMS generator 522 is adapted to perform a process for preventing 
fluctuation of density in the image due to difference of the ejecting or 
expelling amount in respective ejection orifices. Sequential 
multi-scanning concerning this process has been proposed in Japanese 
Patent Application Laying-open No. 5-330083. In the disclosed system, 
density fluctuation is reduced by expelling ink through a plurality of 
ejection orifices for one pixel and whereby the quality of the printed 
image is improved. In the SMS generator 522, whether multi-scanning is 
performed or not for providing preference to high printing speed, can be 
instructed through an appropriate input means, such as the operating and 
display portion 103 or the host computer H. 
The transfer memory 524 is a buffer memory for correcting physical position 
of the ink-jet heads, namely the position between the upper and lower 
printing portion shown in FIG. 2 or position between each heads. The image 
data is temporarily input to the transfer memory 524 and output at a 
timing corresponding to the physical position of the heads. Accordingly, 
the transfer members 524 are differentiated in capacity for respective 
colors. 
After performing the data processing set forth above, the data is 
transferred to the ink-jet heads 13C and 13C' for cyan C via a heat 
transfer board 107. 
FIG. 8 shows a relationship between ejecting amount of ink to the cloth and 
dyeing density. In FIG. 8, the axis of abscissa represents the ink 
ejection amount indicated as a ratio taking the maximum ejection amount in 
the unit area as 100. The axis of ordinate represent a function K/S (K: 
absorption coefficient, S: scattering coefficient) of reflectivity R of 
the dyed article after finishing color development and washing process 
subsequent of printing on the cloth, which is expressed by: 
EQU K/S=(1-R).sup.2 /2R 
The value of K/S is the value quantizing the visual dyeing density. 
In FIG. 8, the density is illustrated as normalized value of K/S value with 
taking the maximum K/S value of cyan as 100, in which greater value 
represents higher density. In FIG. 8, there are also illustrated the 
characteristics of yellow, magenta, cyan, black as standard color and blue 
as special color. 
As can be clear from FIG. 8, in comparison with yellow, magenta and cyan, 
black and blue as the special color may obtain approximately half density. 
FIG. 9 is a diagrammatic illustration showing an example of construction of 
ink supply system in the shown embodiment of the textile printing 
apparatus. Here, reference numerals 51 and 51' denote ink bottles forming 
ink supply source for the lower stage ink-jet head 13 and the upper stage 
ink-jet head 13', respectively. These ink bottles 51 and 51' may be in a 
form of cartridge detachable to the shown embodiment of the apparatus. 
Reference numerals 55 and 55' denote sub-tanks as intermediate ink storage 
members arranged in respective ink supply passages between the ink bottle 
51 and the lower head 13 and between the ink bottle 51' and the upper head 
13', which store ink supplied from the ink bottles 51 and 51' and also 
stores ink recirculated from the heads 13 and 13', respectively. The 
liquid levels in these sub-tanks 55, 55' may be maintained constant by 
appropriate liquid level sensors, not shown valves disposed in the ink 
supply passages and driving means thereof, or by constructing the sub-tank 
as enclosed system, and thereby maintain the supply pressure of the ink 
for the heads 13 and 13' constant. 
Reference numerals 57A and 57'A denote ink tubes forming an ink supply 
passage from the sub-tank 55 to the lower head 13 and an ink supply 
passage from the sub-tank 55' to the upper head 13', respectively. Parts 
of the ink tubes 57A and 57'A are formed with flexible members connected 
to ink connectors 59 and 59' provided on the carriages 24 and 24' (see 
FIG. 2) to follow the scanning motion of the latter. Reference numerals 
57B and 57'B denote ink tubes similar to the ink tubes 57A and 57'A and 
forming ink recirculation passages to the sub-tanks 55 and 55'. Reference 
numerals 60 and 60' denote pressurizing motors for pressurizing ink supply 
system via the tubes 57A and 57'A for forcedly discharging ink through the 
heads 13 and 13' during recovery operation set forth above, respectively. 
As shown in FIG. 9, in the shown embodiment, completely independent ink 
supply systems are arranged for upper stage head array and lower stage 
head array, and such two ink supply systems are arranged for respective 
heads. As set forth above, respective ink supply systems supply inks of 
mutually different composition for each color corresponding to two kinds 
of fibers of the blended fiber cloth having mutually different dyeing 
properties. 
Here, a preferred blended fiber cloth or fabric which can enhance the 
effect of the present invention as applied for the shown embodiment of the 
textile printing apparatus may have fiber blending ratio in the following 
range. Namely, in case of blended fiber cloth of two kinds of fibers, the 
preferred blending ratio by weight is in a range of 10:1 to 1:10, more 
preferably in a range of 3:1 to 1:3. In case the blending ratio is out of 
the above-mentioned range, necessity for using different composition of 
ink for the same color becomes low and can attain sufficient coloring even 
when one kind of ink adapted to the fiber having greater proportion of 
blending. In such case, while overall ink amount ejected to the cloth 
becomes smaller since the ink corresponding to the fiber of smaller 
proportion is not used, influence of not ejecting the ink will not be 
perceptible in the finally obtained printed article for small proportion 
of the corresponding fiber. 
On the other hand, in case of blended fiber cloth of three kinds of fibers 
or more, ink having composition adapted to the fiber should be used for 
the fiber having proportion greater than or equal to 10% by weight in the 
cloth. 
It should be appreciated that in the case where printing is performed only 
with ink corresponding to the fiber having large blending rate depending 
upon the blending ratio, sufficient coloring may be obtained without 
causing lowering of density of the image by employing ink of higher dye 
concentration or by increasing ejecting amount of the ink. 
As set forth above, in the case where ejection of the inks of the same 
color and different composition is performed through respective upper and 
lower ink-jet heads 13' and 13, the SMS generator 522 passes the data 
through and does not perform distribution of the image data for the upper 
and lower heads. Namely, the upper and lower heads ejecting the inks of 
the same color and different compositions performs ejecting of the inks 
for printing the identical image. 
Considering the case of printing on the blended fiber cloth of cotton and 
polyester, the ink containing reactive dye for cotton is employed for the 
upper ink supply system and the ink containing disperse dye for polyester 
is employed for the lower ink supply system. By this, cotton forming the 
blended cloth is effectively dyed by the reactive dye ejected by the upper 
head and polyester is effectively dyed by the disperse dye ejected by the 
lower head. 
As set forth, the upper ink-jet head 13' and the lower ink-jet head 13' 
eject inks of the same color and different compositions. In the shown 
embodiment, on the portion of the cloth where the ejected ink from the 
lower head 13 is propagated, the ejected ink from the upper head 13' is 
propagated in overlaying manner so that respective dyes may color the 
corresponding fibers effectively depending upon the dyeing properties. For 
instance, in the case of the example set forth above, the ink ejected from 
the lower head 13 effectively colors the polyester fiber and the ink 
ejected from the upper head 13' effectively colors the cotton fiber. In 
such case, as long as no problem in color development is arisen with 
elaboration in preparation for the cloth, inks may be ejected in any 
order. 
However, in general, in case of 1) ink containing reactive dye, 2) ink 
containing acid dye, direct dye or basic dye, 3) ink containing disperse 
dye, ejecting the inks in order of 1), 2), 3) is preferred in view of 
uniformity of coloring and stability of color development. 
The inks of 1) to 3) set forth above are differentiated in dyeing 
mechanism. Namely, the disperse dye forming the ink of 3) dyes the fiber 
in a manner that the disperse dye diffuses in the specific fiber and is 
physically joined to the fiber, precedingly adhering ink may have little 
influence for dyeing. Therefore, the ink of 3) may cause little problem in 
coloring even when it is ejected after dyeing by the ink of 1) or 2). 
On the other hand, inks of 1) and 2) color the specific fibers by covalent 
bonding and ion bonding, it can be influenced in dyeing property by the 
precedingly adhering ink. Therefore, it is desirable to eject the ink of 
1) and 2) in advance. 
Furthermore, the order of ejection of the inks of 1) and 2) will not cause 
significant problem. However, it is desirable to eject the ink of 1) which 
dyes by covalent bonding at earlier timing for improving uniformity of 
dyeing and stability of coloring. 
(Second Embodiment) 
FIG. 10 shows another embodiment of the present invention, in which is 
illustrated a construction image processing system incorporating means for 
switching density to be printed by each of the upper and lower heads. It 
should be appreciated that while FIG. 10 illustrates a system 
corresponding to cyan color, the same construction is, of course, 
applicable for each color. 
In the shown embodiment, the construction subsequent to the HS conversion 
table 511 shown in FIG. 6 in the former embodiment, is provided as two 
systems (which are illustrated with reference numerals common to FIG. 6 
but with extensions of "-1" and "2"), as shown in FIG. 10. The density of 
coloring (ink amount) by the upper head is controlled by gamma-conversion 
table 513-1, and the density of coloring (ink amount) by the lower head is 
controlled by gamma-conversion table 513-2. Then, necessary processes are 
performed subsequently. 
With such construction, modification of coloring ratio by the reactive dye 
and disperse dye depending upon blending ratio of two kinds of fibers 
having different dyeing properties in the blended fiber cloth, can be 
realized. Also, correction in the case where the reactive dye and disperse 
dye are different in density while the ejection amounts are the same, can 
be realized. 
In such case, in general, the proportion of dyes by weight depending upon 
the blending ratio of fibers of the cloth is preferably set to be slightly 
lower than the fiber blending ratio in the disperse dye and to be slightly 
high than the fiber blending ratio in the reactive dye. 
This is because that when printing is performed with the same weight ratios 
of disperse dye and reactive dye, the reactive dye has tendency to be 
difficult to dye in comparison with the disperse dye. This tendency is 
caused by the dyeing mechanism and the difference in a molar absorptivity 
between above-stated two kinds of dyes. Therefore, it is desirable to 
provide the reactive dye in slightly greater amount. On the other hand, in 
the case of the disperse dye, since it dyes the fiber by penetrating in 
the fiber by its molecular structure, it becomes possible to have lower 
dye ratio relative to the fiber blending ratio. 
While heads are arranged on upper and lower two stages of carriage for each 
color and thus arrange two heads for each color at different positions in 
the cloth feeding direction for ejecting inks having different 
compositions in each embodiment set forth above, the arrangement of heads 
is not necessarily the different positions in the cloth feeding direction 
but can be arranged on the common carriage. Also, number of stages of the 
carriage is not specified to be two, but can be one or three or more. 
Furthermore, the blended fiber cloth is not necessarily fabricated by two 
fibers having different dyeing properties but can be fabricated with three 
or more kinds of fibers. Therefore, the apparatus may have three or more 
kinds of inks for each color. 
Subsequently, the description will be made of the entire processes of the 
ink jet textile printing. After the ink jet textile printing process is 
executed by the use of the above-mentioned ink jet printing apparatus, the 
textile is dried (including natural drying). Then, in continuation, the 
dyestuff on textile fabric is dispersed, and a process is executed to 
cause the dyestuff to be reactively fixed to the fabric. With this 
process, it is possible for the printed textile to obtain a sufficient 
coloring capability and strength because of the dyestuff fixation. 
For this dispersion and reactive fixation processes, the conventionally 
known method can be employed. A steaming method is named, for example. 
Here, in this case, it may be possible to give an alkali treatment to the 
textile in advance before the textile printing. 
Then, in the post-treatment process, the removal of the non-reactive 
dyestuff and that of the substances used in the preparatory process are 
executed. Lastly, the defect correction, ironing finish, and other 
adjustment and finish processes are conducted to complete the textile 
printing. 
Particularly, the following performatory characteristics are required for 
the textile suitable for the ink jet textile printing: 
(1) Colors should come out on ink in a sufficient density. 
(2) Dye fixation factor is high for ink. 
(3) Ink must be dried quickly. 
(4) The generation of irregular ink spread is limited. 
(5) Feeding can be conducted in an excellent condition in an apparatus. 
In order to satisfy these requirements, it may be possible to give a 
preparatory treatment to the textile used for printing as required. In 
this respect, the textile having an ink receiving layer is disclosed in 
Japanese Patent Application Laying-open No. 62-53492, for example. Also, 
in Japanese Patent Application Publication No. 3-46589, there are proposed 
the textile which contains reduction preventive agents or alkaline 
substances. As an example of such preparatory treatment as this, it is 
also possible to name a process to allow the textile to contain a 
substance selected from an alkaline substance, water soluble polymer, 
synthetic polymer, water soluble metallic salt, or urea and thiourea. 
As an alkaline substance, there can be named, for example, hydroxide alkali 
metals such as sodium hydroxide, potassium hydroxide; mono-, di-, and 
tori-ethanol amine, and other amines; and carbonate or hydrogen carbonate 
alkali metallic salt such as sodium carbonate, potassium carbonate, and 
sodium hydrogen carbonate. Furthermore, there are organic acid metallic 
salt such as calcium carbonate, barium carbonate or ammonia and ammonia 
compounds. Also, there can be used the sodium trichloroacetic acid and the 
like which become an alkaline substance by steaming and hot air treatment. 
For the alkaline substance which is particularly suitable for the purpose, 
there are the sodium carbonate and sodium hydrogen carbonate which are 
used for dye coloring of the reactive dyestuffs. 
As a water soluble polymer, there can be named starchy substances such as 
corn and wheat; cellulose substances such as carboxyl methyl cellulose, 
methyl cellulose, hydroxy ethel cellulose; polysaccharide such as sodium 
alginic acid, gum arabic, locasweet bean gum, tragacanth gum, guar gum, 
and tamarind seed; protein substances such as gelatin and casein; and 
natural water soluble polymer such as tannin and lignin. 
Also, as a synthetic polymer, there can be named, for example, polyvinyl 
alcoholic compounds, polyethylene oxide compounds, acrylic acid water 
soluble polymer, maleic anhydride water soluble polymer, and the like. 
Among them, polysaccharide polymer and cellulose polymer should be 
preferable. 
As a water soluble metallic salt, there can be named the pH4 to 10 
compounds which produce typical ionic crystals, namely, halogenoid 
compounds of alkaline metals or alkaline earth metals, for example. As a 
typical example of these compounds, NaCl, Na.sub.2 SO.sub.4, KCl and 
CH.sub.3 COONa and the like can be named for the alkaline metals, for 
example. Also, CaCl.sub.2, MgCl.sub.2, and the like can be named for the 
alkaline earth metals. Particularly, salt such as Na, K and Ca should be 
preferable. 
In the preparatory process, a method is not necessarily confined in order 
to enable the above-mentioned substances and others to be contained in the 
textile. Usually, however, a dipping method, padding method, coating 
method, spraying method, and others can be used. 
Moreover, since the printing ink used for the ink jet textile printing 
merely remains to adhere to the textile when printed, it is preferable to 
perform a subsequent reactive fixation process (dye fixation process) for 
the dyestuff to be fixed on the textile. A reactive fixation process such 
as this can be a method publicly known in the art. There can be named 
steaming method, HT steaming method, and thermofixing method, for example. 
Also, alkaline pad steaming method, alkaline blotch steaming method, 
alkaline shock method, alkaline cold fixing method, and the like can be 
named when a textile is used without any alkaline treatment given in 
advance. 
Further, the removal of the non-reactive dyestuff and the substances used 
in the preparatory process can be conducted by a rinsing method which is 
publicly known subsequent to the above-mentioned reactive fixation 
process. In this respect, it is preferable to conduct a conventional 
fixing treatment together when this rinsing is conducted. 
In this respect, the printed textile is cut in desired sizes after the 
execution of the above-mentioned post process. Then, to the cut off 
pieces, the final process such as stitching, adhesion, and deposition is 
executed for the provision of the finished products. Hence, one-pieces, 
dresses, neckties, swimsuits, aprons, scarves, and the like, and bed 
covers, sofa covers, handkerchiefs, curtains, book covers, room shoes, 
tapestries, table cloths, and the like are obtained. The methods of 
machine stitching the textile to make clothes and other daily needs are 
disclosed widely in publicly known publications such as "Modern Knitting 
and Sewing Manual" published by the Textile Journal Inc. or a monthly 
magazine "Souen" published by Bunka Shuppan Kyoku, and others. 
As described above, according to the present invention, it is possible to 
obtain a high cleaning effect of the liquid discharging surface of the 
liquid discharging head as well as a long-time stability of the liquid 
discharging. 
Thus, it is possible to produce the effect that the stable recovery can be 
executed even in a case where a highly viscous liquid is used or highly 
densified nozzles are employed, or further, an industrial use is required 
for a long time under severe conditions. 
The present invention produces an excellent effect on an ink jet printing 
head and printing apparatus, particularly on those employing a method for 
utilizing thermal energy to form flying ink droplets for the printing. 
Regarding the typical structure and operational principle of such a method, 
it is preferable to adopt those which can be implemented using the 
fundamental principle disclosed in the specifications of U.S. Pat. Nos. 
4,723,129 and 4,740,796. This method is applicable to the so-called 
on-demand type printing system and a continuous type printing system. 
Particularly, however, it is suitable of the on-demand type because the 
principle is such that at least one driving signal, which provides a rapid 
temperature rise beyond a departure from nucleation boiling point in 
response to printing information, is applied to an electrothermal 
transducer disposed on a liquid (ink) retaining sheet or liquid passage 
whereby to cause the electrothermal transducer to generate thermal energy 
to produce film boiling on the thermoactive portion of the printing head; 
thus effectively leading to the resultant formation of a bubble in the 
printing liquid (ink) one to one for reach of the driving signals. By the 
development and contraction of the bubble, the liquid (ink) is discharged 
through a discharging port to produce at least one droplet. The driving 
signal is preferably in the form of pulses because the development and 
contraction of the bubble can be effectuated instantaneously, and, 
therefore, the liquid (ink) is discharged with quicker responses. 
The driving signal in the form of pulses is preferably such as disclosed in 
the specifications of U.S. Pat. Nos. 4,463,359 and 4,345,262. In this 
respect, if the conditions disclosed in the specification of U.S. Pat. No. 
4,313,124 regarding the rate of temperature increase of the heating 
surface preferably are adopted, it is possible to perform an excellent 
printing in a better condition. 
The structure of the printing head may be as shown in each of the 
above-mentioned specifications wherein the structure is arranged to 
combine the discharging ports, liquid passages, and electrothermal 
transducers as disclosed in the above-mentioned patents (linear type 
liquid passage or right angle liquid passage). Besides, it may be possible 
to form a structure such as disclosed in the specifications of U.S. Pat. 
Nos. 4,558,333 and 4,459,600 wherein the thermally activated portions are 
arranged in a curved area. 
Furthermore, as a full line type printing head having a length 
corresponding to the maximum printing width, the present invention 
demonstrates the above-mentioned effect more efficiently with a structure 
arranged either by combining plural printing heads disclosed in the 
above-mentioned specifications or by a single printing head integrally 
constructed to cover such a length. 
In addition, the present invention is effectively applicable to a 
replaceable chip type printing head which is connected electrically with 
the main apparatus and can be supplied with ink when it is mounted in the 
main assembly, or to a cartridge type printing head having an integral ink 
container. 
Furthermore, as a printing mode for the printing apparatus, it is not only 
possible to arrange a monochromatic mode mainly with black, but also it 
may be possible to arrange an apparatus having at least one of multi-color 
mode with different color ink materials and/or a full-color mode using the 
mixture of the colors irrespective of the printing heads which are 
integrally formed as one unit or as a combination of plural printing 
heads. The present invention is extremely effective for such an apparatus 
as this. 
Now, in the embodiments according to the present invention set forth above, 
while the ink has been described as liquid, it may be an ink material 
which is solidified below the room temperature but liquefied at the room 
temperature or may be liquid. Since the ink is controlled within the 
temperature not lower than 30.degree. C. and not higher than 70.degree. C. 
to stabilize its viscosity for the provision of the stable discharge in 
general, the ink may be such that it can be liquefied when the applicable 
printing signals are given. 
In addition, while preventing the temperature rise due to the thermal 
energy by the positive use of such energy as an energy consumed for 
changing states of the ink from solid to liquid, or using the ink which 
will be solidified when left intact for the purpose of preventing ink 
evaporation, it may be possible to apply to the present invention the use 
of an ink having a nature of being liquefied only by the application of 
thermal energy such as an ink capable of being discharged as ink liquid by 
enabling itself to be liquefied anyway when the thermal energy is given in 
accordance with printing signals, an ink which will have already begun 
solidifying itself by the time it reaches a printing medium. 
In addition, as modes of a printing apparatus according to the present 
invention, there are a copying apparatus combined with reader and the 
like, and those adopting a mode as a facsimile apparatus having 
transmitting and receiving functions, besides those used as an image 
output terminal structured integrally or individually for an information 
processing apparatus such as a word processor and a computer. 
The present invention has been described in detail with respect to 
preferred embodiments, and it will now be that changes and modifications 
may be made without departing from the invention in its broader aspects, 
and it is the intention, therefore, in the appended claims to cover all 
such changes and modifications as fall within the true spirit of the 
invention.