Color recording method and device

A color recording method and device which is capable of color recording images on large-sized paper in which a first color is developed in direct heat sensitive paper by directly supplying heat energy of thermal heads to the direct heat sensitive paper. Furthermore, in order to transfer a color ink to the direct heat sensitive paper to thereby obtain a second color, the heat energy of the thermal heads is supplied to a plurality of ink ribbons which are coated with both a desensitizing material for controlling the coloring reaction of the direct heat sensitive paper and the desired colored inks.

BACKGROUND OF THE INVENTION 
The present invention relates to color recording and, in particular, to 
both a color recording method and a device which are capable of recording 
images in multiple, e.g., 2 to 5, colors on large-sized paper. 
As is known well in the art, ink jet systems, electronic copying systems, 
thermal sublimation type transfer systems, thermal fusion type transfer 
systems and the like can be employed in color recording. 
Moreover, because the mechanisms associated with thermal sublimation type 
transfer systems and thermal fusion type transfer systems are relatively 
simple, a compact recording device can be provided and the cost of the 
device can be reduced. Also, the use of ribbons respectively coated with 
different color inks, e.g., a yellow ink, a magenta ink and a cyan ink, 
allows color recording to be readily achieved. 
As mentioned above, although a variety of systems are available for 
obtaining color recording, when the size and cost of the device are taken 
into consideration, choices which would be acceptable to ordinary users 
become more limited. 
One example of a system which can satisfy both the size and cost 
requirements is the thermal transfer system. However, in such thermal 
transfer systems, the ribbons are expensive and can be quickly consumed, 
thus, the operating cost of such a system can be quite high. Also, because 
thermal transfer devices are typically arranged so as to provide 
"full-color" recording, the device inevitably becomes expensive. 
From the viewpoint of the ordinary users, it is not always necessary that 
the recording device be adapted to the full-color recording but, in most 
cases, it is adequate that the recording device be capable of recording in 
multiple colors in the range of 2 to 5 colors. 
Further, in recent years, the need has also arisen to record on paper 
having a larger size including paper of an A1 size or greater, e.g., 
poster and the like. 
However, conventional recording systems can not record multiple colors on 
large-sized paper at costs acceptable to ordinary users. 
SUMMARY OF THE INVENTION 
Among other things, the present invention aims at eliminating the drawbacks 
found in the above-mentioned conventional recording methods. Accordingly, 
it is an object of the invention to provide a color recording method and 
device which are capable of relatively simple, cost effective, color 
recording on large-sized paper. 
In attaining the foregoing, the present invention relates to a color 
recording method which comprises the steps of developing a color in direct 
heat sensitive paper which contains a leuco dye and a color developer to 
thereby obtain a first color, and transferring an ink and desensitizing 
material, which desensitizing material controls the coloring reaction of 
the direct heat sensitive paper, and thus provides a second color 
corresponding to the color ink. 
Also, there is provided a color recording method in which the 
above-mentioned first color is developed in the major area of the direct 
heat sensitive paper, while the second color is transferred to the minor 
area of the direct heat sensitive paper. 
In another aspect, the present invention relates a color recording device 
which supplies the heat energy of the heads directly to the direct heat 
sensitive paper in order to develop a first color in the direct heat 
sensitive paper, and, in order to transfer a color ink to the direct heat 
sensitive paper and thereby produce a second color, also supplies the heat 
energy of the heads to a plurality of ink ribbons. These ink ribbons are 
coated with both a desensitizing material for controlling the coloring 
reaction of the direct heat sensitive paper and inks having a desired 
color. 
Another aspect of the invention relates to a color recording device which 
comprises a first recording part for supplying the heat energy of the 
heads directly to the direct heat sensitive paper to thereby develop the 
first color, and a second recording part for transferring the color ink to 
the direct heat sensitive paper to thereby transfer the second color. 
According to still another aspect of the invention, a color recording 
device in which the plurality of ink ribbons are each movable in the 
feeding direction of the direct heat sensitive paper, the plurality of ink 
ribbons are arranged in a plurality of lines independent of one another, 
and heads for scanning the direct heat sensitive paper line by line are 
disposed opposite to the direct heat sensitive paper, is provided. In 
developing the first color in the direct heat sensitive paper, the heat 
energy of the heads is supplied directly to the direct heat sensitive 
paper, and, in order to obtain the second color from the plurality of ink 
ribbons, a required ribbon is set opposed to the heads and the heat energy 
of the heads is supplied to the ink ribbon to thereby transfer ink from 
the ribbon to the direct heat sensitive paper. 
Also, a plurality of mutually independently arranged ink ribbons can be 
employed to provide for the desired colors, which ribbons are movable in 
the feeding direction of the direct heat sensitive paper, thus, heat 
energy can be supplied to both the direct heat sensitive paper and the ink 
ribbon by, e.g., a plurality of thermal heads which are arranged in a 
single line. 
As is apparent, the recording method and device of the present invention 
can provide "first" and "second" colors, that is, the first color can be 
obtained by developing a color in the direct heat sensitive paper, while 
the second color can be obtained by transferring a color ink. In this 
regard, both the ink and the desensitizing material which controls the 
reaction of a leuco dye and a color developer contained in the heat 
sensitive layer of the direct heat sensitive paper, are transferred to the 
direct heat sensitive paper. Because the coloring reaction at that portion 
of the direct heat sensitive paper to which the desensitizing material is 
transferred can be prevented, the first color is not developed, and the 
second color is therefore, not dull, but instead, unexpectedly vivid. By 
transferring various color inks to the direct heat sensitive paper, the 
second (as well as third, fourth, fifth and so on) colors can be provided. 
The first color is typically formed in the major area of the direct heat 
sensitive paper and the second color is formed in the minor area thereof, 
so that a multi-color recording can be easily provided.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
A description will be provided for certain embodiments of the color 
recording method and device according to the invention. 
FIG. 1 shows a recording process according to the invention. 
As shown in FIG. 1(a), an ink ribbon 101 includes a base film 103 as well 
as an ink layer 105 and a control layer 107 both of which are coated in 
this order on the base film 103. 
The ink layer 105 is a primary color ink layer, such as a red ink layer, a 
blue ink layer and the like, or combinations thereof. For example, if red 
and blue are allocated to the ink layer and the ink ribbons having such 
ink layers respectively are sequentially arranged in parallel to each 
other, then there can be produced a two-color, or red-and-blue ink ribbon. 
The inks which can be employed within the present invention can include any 
ink well recognized in the art suitable for use in thermal transfer. 
Preferred inks are described in PRINTER DESIGN of TRICEPS CO., LTD. 
The amount/thickness of this ink layer is typically is the same as that 
associated with conventional ink ribbons. 
The control layer 107 is a layer of desensitizing material which controls 
the coloring reaction of a leuco dye and a color developer to be described 
later. 
The desensitizing material can be any compound which controls the reaction 
of a leuco dye and a color developer contained in the heat sensitive 
transfer layer of the direct heat sensitive paper. Suitable examples of 
the desensitizing materials, include: esters including trioctyl phosphate, 
triphenyl phosphate, tricresyl phosphate, dioctyl adipate, dibutyl 
sebacate, dioctyl phthalate, dicyclohexyl phthalate, tributyl 
trimellitate, sorbitan fatty acid esters, polyoxyalkylene fatty acid 
esters, and the like; alcohols including as oleoyl alcohol, tridecyl 
alcohol, benzyl alcohol, and the like; ketones, including acetophenone, 
methylcyclohexanone, phorone, and the like; ethers including polyalkylene 
glycols, polyoxyalkylenealkylamines, polyoxyalkylene oleoyl ethers, 
polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, 
polyoxyalkylene alkylphenol ethers, and the like; and, organic bases 
including monoalkylamines, dialkylamines, trialkylamines, 
triphenylguanidine, dicyclohexylguanidine, 2-benzylimidazole, 
2-phenol-4-methylimidazole, 2-undecylimidazoline, 
2,4,5-trifuryl-2-imidazoline, N,N'-dibenzylpiperazine, and the like. 
Moreover, these desensitizing materials can be used individually or in 
combination. The desensitizing material are present in an amount such 
that, upon transfer, they can prevent any substantial developing reaction 
between the leuco dye and the developing agent. In this regard, they are 
at least present in an amount of 10 wt %, preferably 30-75 wt %, to the 
whole transferring layers. 
Direct heat sensitive paper 111 includes a base 113 coated with a heat 
sensitive recording layer 115 containing therein a leuco dye and a color 
developer. 
Such direct heat sensitive papers are recognized in the art as disclosed in 
PRINTER DESIGN of TRICEPS CO., LTD. 
Both the leuco dyes and the color developers are also recognized within the 
art and as such need not be described in detail here. These components are 
typically employed in amounts recognized in the art as described in 
PRINTER DESIGN of TRICEPS CO., LTD. 
As shown in FIG. 1(b), if the heat energy of a thermal head 121 is applied 
to the ink ribbon 101, then both the control layer 107 and ink layer 105 
of the ink ribbon 101 are transferred to the heat sensitive layer 115 of 
the direct heat sensitive paper 111. Due to the transfer of the ink layer 
105, the heat sensitive recording layer 115 is going to develop a color. 
However, as shown in FIG. 1(c), the color developing or coloring reaction 
of the heat sensitive recording layer 115 can be controlled due to the 
action of the control layer 107. 
The above-mentioned ink ribbon 101 has a structure that the two layers, 
namely, the ink layer 105 formed of the primary color and the control 
layer 107 formed of the desensitizing material are respectively supported 
on the base film 103. However, alternatively, the ink ribbon 101 may have 
another structure, e.g., a single layer containing both ink and 
desensitizing material can be supported on the base film. 
Next, a description will be provided of a first embodiment of a color 
recording device according to the invention. 
FIG. 2 provides a flow sheet for a color recording device according to the 
invention. In FIG. 2, direct heat sensitive paper 203, which can be driven 
and fed by feed rollers 201, is firstly pressed against and supported by a 
platen roller 207 and is directly printed by a thermal head 209 in a first 
recording part 205. Then, in a second recording part 210, the direct heat 
sensitive paper 203 is transferred and printed by a thermal head 213 
through a required ink ribbon out of a plurality of ink ribbons to be 
stored in a ink ribbon cartridge 211. 
FIG. 3 is a block diagram of a control part of the above-mentioned color 
recording device. The control part comprises a digitizer 301 for 
instructing color conversion and conversion area with respect to the image 
information to be input, a scanner 303 for inputing the image information 
therein, an operation panel 305 for instructing the magnification 
conversion of the image instructed for conversion to thereby specify a 
print size, a random access memory (which is hereinafter referred to as 
RAM) 306 for storing and holding therein editing data in connection with 
the instructed conversion processing, a RAM 307 for storing and holding 
image data therein, a RAM 308 for storing and holding therein the image 
data including the color conversion data, a read only memory (which is 
hereinafter referred to as ROM) 309 for storing a system program used to 
execute the instructed processing, a printer 311 for outputing the 
processed image information, an interface 313 for connecting the 
associated equipment with each other, and a central processing unit 315 
(which is hereinafter referred to as CPU) for controlling the timing of 
the whole device. 
FIG. 4 illustrates a print produced by the above color recording device. 
That is, for a character existing on a black and white manuscript 401, 
mutually opposing points i), ii) and iii), iv) representing color 
conversion areas are specified, and red is specified to the area to be 
defined by the opposing points i), ii), while blue is specified to the 
area to be defined by the opposing points iii), iv). After completion of 
the color conversion processing, the print size is specified. 
On the print 403 on which the color conversion and magnification conversion 
processings have both been performed, there are then formed a red 
character, a blue character respectively printed through the 
above-mentioned ink ribbons, and a black character printed directly on the 
direct heat sensitive paper. 
Next, the operation of the above color recording device with reference to 
FIGS. 5 and 6 which show the flow charts of the processings to be 
performed by the color recording device, will be discussed. 
The power supply of the device is started (S501), and then the position of 
the first thermal head for checking the presence or absence of the 
recording paper and for executing printing directly and the position of 
the second thermal head for executing transfer printing are detected 
respectively, so that the device is initialized (S502). 
Then, a manuscript is set on the digitizer (S503), and the color conversion 
is specified to the desired area of the manuscript (S504). The color 
conversion data are stored and held in the RAM 308 (S505). By performing 
the processings in S504 and S505 repeatedly, the color conversion 
specification is executed a required number of times. 
After completion of the color conversion (S506 Yes), it is checked whether 
the necessary ink ribbon(s) for the color conversion are set in the second 
recording part (S507). 
If the ink ribbon is not set (S507 No), then the ink ribbon is set (S508) 
and, then, the manuscript is set on the scanner (S509) and the start of 
scanning is instructed (S510). 
The scanner reads the image data sequentially in a line unit (S511), and 
the image data are stored and held in the RAM 306 until the recording is 
completed in the first and second recording parts (S512). And, the image 
data are read out sequentially (S513) and it is checked sequentially 
whether the image data are the above-mentioned color conversion data or 
not (S514). 
If it is not necessary for the readout image data to be color converted 
(S514 No), then the image data is immediately recorded directly in the 
recording paper in the first recording part (S515). If it is necessary 
that the readout image data be color converted by means of the color 
conversion data (S514 Yes), then it is detected whether an ink ribbon 
corresponding to the color specified by the second recording part is set 
at a given position (S516). If sequential recording (to be described 
later) is executed, then it is detected whether ink ribbons respectively 
corresponding to a plurality of colors are set at their given positions. 
A plurality of ink ribbon cartridges are incorporated in the second 
recording part, and, if the corresponding ink ribbon is not set at its 
given position (S516 No), then the corresponding cartridge in set at its 
given position (S517). 
Then, in the second recording part, the image data containing the color 
conversion data are recorded and held in the RAM 307 (S518), the CPU 
determines that the corresponding line has reached the second recording 
part and the transfer recording is started (S519). The recording in the 
second recording part is controlled by the CPU and is executed at the 
optimum timing, and thus it can be controlled independent of the recording 
operation in the first recording part. 
Also, because a specified color may be produced by means of over-recording 
of a plurality of colors, it is determined whether such over-recording is 
necessary (S520). In addition to over-recording, when executing the 
sequential recording in which a plurality of colors are recorded in the 
same line, it is determined whether the sequential recording is necessary. 
If it is determined that over-recording is necessary (S520 No), then the 
feeding of the recording paper is stopped (S521) and it is determined 
whether the ink ribbons to be over-recorded are set at the desired 
position (S516). Then, the over transfer recording of a plurality of 
desired inks is executed on the same line. 
If the over-recording is not necessary (S520 Yes), then the stop of the 
feeding of the recording paper is removed (S522) to thereby resume feeding 
the recording paper. 
After the reading of the image data on the manuscript is completed (S523 
Yes), the processings in and after S511 are executed on all image data, 
and the end of the feeding of the recording paper is confirmed (S524), the 
print is completed (S525). 
In the above-described embodiment, the description has been given of an 
example in which an image is recorded on the direct heat sensitive paper 
shown in FIG. 1. However, alternatively, the image can be recorded on a 
heat transfer sheet consisting of a combination of two kinds of sheets 
bonded to each other: that is, a heat sensitive recording sheet including 
a support member and a heat sensitive recording layer coated on the 
support member and containing therein a leuco dye and a color developer; 
and, a heat sensitive transfer donor sheet including a support member and 
a heat sensitive transfer layer coated on the support member and 
containing ink and desensitizing material for controlling the reaction of 
the leuco dye and color developer. 
In this embodiment, in the first recording part, the desensitizing material 
and ink are transferred to the heat sensitive recording sheet, whereby 
only the coloring due to the ink can be developed on the heat sensitive 
recording sheet. Next, the heat sensitive transfer donor sheet is peeled 
off, heat energy is applied to the non-coloring portion of the heat 
sensitive recording sheet, whereby only the coloring due to the leuco dye 
and color developer layer can be developed on the heat sensitive recording 
sheet. 
A second embodiment of a color recording device according to the invention 
with reference to FIGS. 7 to 9 will now be described. 
FIGS. 7 to 9 illustrate a schematic side view, schematic plan view and 
schematic front view, respectively, of the color recording device. 
In particular, a direct heat sensitive paper 703 wound around a roller 701 
is fed and moved in a direction of an arrow a in FIG. 7 while it is driven 
by a feed roller 705 and is guided by a guide 706. 
In a direction perpendicular to the feeding direction of the direct heat 
sensitive paper 703, ink ribbons 707a, 707b, 707c and 707d respectively 
coated with yellow, cyan, magenta and black inks are wound by cartridges 
709a, 709b, 709c, and 709d, respectively. 
The cartridges 709a to 709d are respectively placed on a moving guide 713 
which is movable along a moving guide rail 711 extending in the paper 
feeding direction. Also, a plurality of thermal heads 715a, 715b, 715c are 
provided and a shuttle 717 movable in a direction of an arrow b in FIG. 9 
is provided so as to extend across the thermal heads. 
At the scanning positions of the thermal heads 715a to 715c, there is 
provided a platen rubber 719 which can be pressed against and support the 
direct heat sensitive paper 703. After recording, the direct heat 
sensitive paper 703 can be cut by a cutter 721. 
Next, the recording operation according to the invention will be described. 
FIG. 10 shows a recording operation to be performed when an image is 
recorded by supplying heat energy directly to the direct heat sensitive 
paper. 
At first, the moving guide 713 is moved in a direction of an arrow c shown 
in FIG. 10 to move the ink ribbons 707a to 707d away from their recording 
positions. After then, the direct heat sensitive paper 703 is fed and 
moved in the direction of arrow a in FIG. 10 and, at the same time, the 
thermal heads 715a to 715c are moved in a direction of an arrow b shown in 
FIG. 10, thereby directly recording the image on the direct heat sensitive 
paper 703. 
FIGS. 11(a) and (b) respectively show a recording operation to be performed 
when the color ink is transferred by supplying heat energy to the ink 
ribbon. 
In particular, FIG. 11(a) shows a case in which yellow is transferred to 
the direct heat sensitive paper 703. That is, by driving the moving guide 
713, the ink ribbon 707a coated with an yellow ink is set opposed to the 
thermal heads 715a to 715c. After then, the direct heat sensitive paper 
703 is fed and moved but also the thermal heads 715a to 715c are moved to 
thereby transfer the yellow ink to the direct heat sensitive paper 703. 
Also, FIG. 11(b) shows a case in which black is transferred to the direct 
heat sensitive paper 703. That is, by driving the moving guide 713, the 
ink ribbon 707d coated with a black ink is set opposed to the thermal 
heads 715a to 715c. After then, the direct heat sensitive paper 703 is fed 
and moved and the thermal heads 715a to 715c are moved to thereby transfer 
the black ink to the direct heat sensitive paper 703. 
Further, when magenta or cyan are recorded, similar to the transfer of the 
yellow and black respectively shown in FIGS. 11(a) and (b), a required ink 
ribbon is set opposed to the thermal heads and the required ink can be 
transferred to the direct heat sensitive paper by movements similar to 
those discussed above. 
The present invention allows the color ink to be transferred to a 
predetermined minor area of the direct heat sensitive paper to thereby 
record the image thereon. This makes it possible to reduce the amount of 
expensive ink ribbon employed. Therefore, when compared with the 
conventional image recording method in which a color ink is transferred by 
use of an ink ribbon, the invention can reduce the operating costs of the 
system. Also, because the color recording is capable of being provided on 
a predetermined minor area and the color recording can be readily achieved 
by heat transfer, a color recording can be produced simply and easily. 
Although the present invention has been described in terms of certain 
embodiments, such are merely illustrative in nature and in no way limit 
the claimed invention. Certain modifications, omissions, and substitutions 
can be made without departing from the spirit thereof. Accordingly, the 
scope of the present invention should only be determined by the scope of 
the following claims, including equivalents thereof.