JP2805577B2 - Thermal transfer printing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a method and apparatus for printing monochromatic and color prints on various types of substrates, especially thermal transfer of images or information onto substrates such as paper (e.g., Printing, thermal wax transfer, dye diffusion transfer, etc.).

[0002]

2. Description of the Related Art Thermal transfer printing includes known printing methods such as thermal wax transfer printing and thermal dye diffusion printing.

[0003] Thermal wax transfer printing is a method in which colorants (eg, magenta, cyan, yellow, and yellow) are dispersed in a wax-based material (wax-based material) in a controlled manner to form an image. (If possible black) from the carrier to a smooth paper-like substrate surface. A thermal transfer print engine having a large number of independently activatable heating elements per unit length is one of the devices available for this purpose. Frequently, the carrier is positioned in the print engine such that one side of the carrier is adjacent to the heating element and the opposite side of the carrier carrying the wax-based material is adjacent to the surface of the substrate on which the printing is to be performed.

[0004] In order to form an image, the print engine and the substrate are relatively moved. If the printhead is to be colored at a location on the arrayed substrate surface, a suitable heating element is activated to locally heat the carrier to a temperature above the colorant melting point. When this heating is performed, the ink containing a certain amount of wax in the colorant becomes soft and adheres to a desired position on the substrate. This separates the ink from the carrier, unheated colorants and poorly heated colorants. To subsequently form a color image, three colors (cyan, magenta, and yellow) or four colors (cyan, magenta, yellow, and black) are successively passed along with different carriers on the same substrate. Note that each of the carriers corresponds to each of the primary colors.

Dye diffusion printing transfers a dye colorant from a carrier, such as a polymer, to a special substrate surface, such as a polyester sheet, in a controlled manner to form an image. In this form of imaging using something similar to the thermally induced subtractive printing technique, a thermal transfer print engine and three different color dye / carrier configurations may be used. However, the operating principle of dye diffusion is different from that of thermal wax transfer printing. In dye diffusion applications, the amount of dye deposited at a single location can be varied so that fine color gradations can be achieved. Dye diffusion techniques can produce images close to photographic quality.

When the print head of a thermal transfer print engine is arranged and colored at a location on the substrate surface, the appropriate heating element is activated to a temperature sufficient to move the appropriate amount of dye. Heat the dye / carrier configuration. Then, the dye is separated from the carrier in the vicinity of the specially constructed substrate. In this way, an appropriate amount of dye contacts and penetrates the substrate due to the molecular dispersion of the dye in the substrate at the desired location.

[0007] Many types of paper, especially bond types common in the United States, have a rough surface, a flat top, and are hollow. Conventional thermal transfer printing techniques cannot be used efficiently with such paper. This is because hollows in the substrate surface structure of the paper can cause adhesion problems or destroy ink or dye points.

Also, most papers are not chemically compatible with diffusive dyes in such a way that the dye substrate in a solid-in-solid manner melts. As a result, bright color images cannot be formed on such substrates using dye diffusion techniques. Rough paper is less expensive than special substrate materials and uses thermal transfer technology to produce high-quality images, so color printing on flat paper substrates is an option. desirable.

One way to increase the useful substrate range in thermal transfer printing is to select the inks and dyes used to form the image. For example, Journal of Imaging Technology, 1991
Abe and Kitamura, "Relationship Between Dynamic Characteristics and Print Quality of Thermal Fused Ink for Thermal Transfer Printing," published on June 119, July, Vol. 17, No. 3, pp. 119-122. Disclose the use of highly extensible inks to reduce the number and deterioration of voids in an image.

Another way to increase the number of substrates available for use in monochromatic printing applications is to use a carrier with multiple layers of ink to place. Theoretically, a first ink layer deposited on a substrate surface, as disclosed in U.S. Pat. No. 4,623,580 to Koshizuka et al., Improves the coverage of a second layer that is simultaneously coated.

However, such single-color techniques do not follow the multi-pass principle used in subtractive color printing. In multi-pass color printing, multiple coatings of colorant reduce image resolution and adhesion as a result of the cumulative thickness of the coating.

Recently, it has been proposed to apply a precoat to a substrate surface which is smoother than conventional substrate surfaces and which is chemically compatible with a predetermined coloring agent. U.S. Patent No. 452717 to Takanashi et al.
No. 4,670,307 to Onishi et al., And US Pat. No. 4,704,615 to Tanaka (Japanese Unexamined Patent Publication No. Sho 62-62).
No. 16192) discloses an example of a thermal transfer printing system using a fusion bonding material that is coated as a precoat on a substrate prior to printing.

In the US patent to Takanashi et al., The entire substrate is coated and printed with a layer of binding material. This method prepares the substrate for colorant coating during printing, but consumes a large amount of binder used during the precoating process. Furthermore, as a result,
The surface of the substrate becomes smooth enough to be identified. This is unpleasant for those who prefer the look and feel of flat paper.

In the Tanaka US patent, a precoat is applied to the substrate at the same pixel location as the colorant coating is performed pixel by pixel. During the precoat material coating period,
The longer pulse width is supplied to the print head element,
Precoat This is done in the area of the slightly wider each pixel location than the colorant. In this Tanaka system, the unprinted portion of the substrate retains the appearance and feel of flat paper, but still has certain problems. In particular, in some cases, it has been found difficult to effectively pre-coat the substrate at individual one-pixel intervals. Such problems are most common in areas where the desired image requires that the colorant be applied very thinly to the substrate. In such areas, sometimes the substrate results from the combined effect of heat loss from a single activated heating element on the print head and the transition period required to bring this heating element to its operating temperature. Precoat material does not provide sufficient coverage.

The precoat material according to Tanaka US patent is envisioned to fill gaps or valleys on the rough substrate surface, rather than bridges across the gap on the rough substrate surface. This is a typical precoat technique commonly used today. Japanese Patent Publication No. Sho 62-77987 discloses that a rough substrate is coated with a composite layer of the adhesive layer and the ink layer so that the adhesive layer forms a bridge in a gap or valley of the substrate. However, coating a precoat or surface preparation layer in the form of a bridge supplied separately from the colorant is not currently known to those skilled in the art.

[0016]

SUMMARY OF THE INVENTION An improved system and method for producing prints, overcoming the shortcomings described above, has long been desired but not realized.

Accordingly, it is an object of the present invention to provide a thermal transfer printing method and apparatus which realize a good image adhered to a rough substrate such as a bond type paper.

Another object of the present invention is to provide a thermal transfer printing method and apparatus for performing thermal transfer printing on a rough substrate and maintaining the rough appearance and feel of the substrate in an area where no image is printed.

Still another object of the present invention, without degrading the image quality by gaps in the surface of the precoat gave colorant, a thermal transfer printing method for printing on the form of coarse substrates used to emphasize the image precoat And the provision of equipment.

It is another object of the present invention to provide an improved print that matches the object.

[0021]

SUMMARY OF THE INVENTION To accomplish the above and many other objects of the present invention, a method for performing thermal transfer printing on a substrate of the type characterized by a rough surface having peaks and valleys is a method of performing rough printing. This rough surface is precoated with an image to form a bridge that intersects the valley between adjacent peaks of the surface, while the interior of the valley is made so that the surface receiving the colorant is more uniform than the rough surface. Eliminate gaps. Then, the colorant is coated on the surface of the pre-coated image enhancement precoat that receives the colorant.

In accordance with the present invention, a method of performing thermal transfer on a substrate characterized by a rough surface having peaks and valleys is provided, wherein the rough surface is partially filled with an image-enhancing precoat to partially fill the rough surface valleys. While removing some gaps in the valleys, creating a partial bridging effect between the peaks, forming a colorant receiving surface that is more uniform than a rough surface. Then, the colorant is coated on the colorant receiving surface of the image enhancement precoat previously coated.

The apparatus of the present invention for performing thermal transfer printing on a substrate of the type characterized by a rough surface having peaks and valleys, forms a bridge across the rough surface valley between adjacent ridges. A configuration that removes substantial gaps in the valley so as to form a surface that receives the colorant more uniformly than the rough surface while applying the image enhancement precoat on the surface, and a colorant for the pre-coated image enhancement precoat A first colorant on the receiving surface.

In the method of performing thermal transfer printing on a substrate according to the present invention, the position where the colorant is disposed on the substrate is determined for each pixel. Next, each predetermined pixel on the substrate on which the colorant is disposed,
An image enhancement precoat is applied to at least one pixel immediately adjacent to each predetermined pixel. However, the adhesion of the precoat to the substrate is further ensured, except for any pixels that are not immediately adjacent to one of the predetermined pixels, but not one of the predetermined pixels. Then, a colorant is coated on the pre-coated predetermined pixels.

According to the present invention, an apparatus for performing thermal transfer printing on a substrate includes a configuration in which the colorant is coated on a pixel-by-pixel basis at a position where the colorant is disposed on the substrate, and a method for coating the colorant on the substrate where the colorant is disposed. Applying image enhancement pre-coating to the predetermined pixels and at least one pixel immediately adjacent to each predetermined pixel (except for pixels that are not one of these predetermined pixels nor directly adjacent to one of the predetermined pixels), It has a configuration that further ensures the adhesion of the precoat to the substrate, and a configuration in which a colorant is coated on predetermined precoated pixels.

According to the present invention, the printed matter that conveys information to the observer includes a substrate, an image-enhanced precoat applied to the substrate with independent pixels, and at least one applied to a corresponding number of precoated pixels. Colorant pixels. Note that at least one pre-coated pixel is disposed immediately adjacent to each pre-coated pixel to which the colorant pixel is applied, and no pre-coat is applied to pixels that are not immediately adjacent to the pre-coated pixel to which the colorant is applied. As such, the pre-coated pixels are located on the substrate.

The method of performing thermal transfer printing on a substrate according to the present invention includes the steps of:
Apply to the surface of the plate. The colorant receiving surface on the upper side of this precoat has one or more gaps. Then, the colorant is coated on the colorant receiving surface. The colorant is formulated and coated such that the coated colorant bridges across gaps in the colorant receiving surface.

Further, according to the present invention, an apparatus for performing thermal transfer printing on a substrate has a configuration in which an image enhancing precoat is applied to the surface of the substrate. The precoat has a colorant receiving surface with one or more gaps. The thermal transfer printing apparatus also has a configuration in which a colorant is coated on the colorant receiving surface. The colorant is formulated and coated such that the coated colorant bridges across gaps in the colorant receiving surface.

Further, the printed matter according to the present invention comprises a substrate, an image enhancing precoat adhered to the substrate, and a colorant adhered to the colorant receiving surface. The precoat has at least one gap. The colorant is also formulated such that the coated colorant bridges across a gap in the colorant receiving surface,
Coated.

[0030] The present invention, a method of thermal transfer printing on a substrate is to determine whether to place the image enhancement <br/> pre Coat that laid colorant and below where on the substrate in pixels, the lower The location of the additional exposure precoat in contact with the image enhancement precoat laid on the image is determined on a pixel-by-pixel basis. Then, an image emphasizing precoat is applied to each predetermined pixel on the substrate on which the colorant is arranged and at least one pixel adjacent to each area where the colorant pixel is arranged. This further ensures the adhesion of the precoat to the substrate.
Further, the coloring agent is coated not on the exposed precoat but on the underlying precoat.

According to the present invention, a printed material for transmitting information to an observer includes a substrate, an image enhancing precoat adhered to the substrate, and a colorant adhered to the colorant receiving surface. The precoat has a colorant receiving surface having at least one gap. The coloring agent is blended so as to have a lower viscosity than the precoat.

Further, according to the present invention, a printed matter that conveys information to an observer includes a substrate, an image enhancing precoat that is adhered to the substrate and includes a colorant receiving surface having at least one gap, A colorant adhered to the colorant receiving surface. This coloring agent is blended so as to have a lower melting temperature than that of the precoat.

The method of the present invention also employs a dye diffusion printing technique that selectively coats a desired amount of one or more dyes on a substrate surface to reduce many or severe image defects. A quality color image is formed on a rough substrate. Also, in the method of the present invention, an image enhancement precoat is applied to the substrate surface using a dye diffusion print engine prior to dye coating. Here, the image-enhancement pre-coat, in combination with the substrate surface, is sufficiently compatible with the substrate surface to realize a more uniform print surface, and the compatibility with the dye is sufficient as the dye diffusion is possible. There is also.

Further, in accordance with the transfer mechanism of the present invention, prior to dye diffusion, a dye diffusion printing technique is used to selectively coat an image enhancing precoat on the substrate surface, thereby providing a rough surface on the substrate. Form high quality color images with reduced many or severe image defects. This transfer mechanism, in combination with the substrate surface, provides an image-enhancing portion having an image-enhancing pre-coat that is sufficiently compatible with the substrate surface to provide a more uniform print surface and provide support. And an image-enhancing precoat and at least one tinted portion with a compatible dye or mixture of dyes so that it can be supported.

The printing apparatus of the present invention uses a dye diffusion printing technique to selectively coat an image-enhancing precoat on the substrate surface prior to dye diffusion using a dye diffusion printing technique on a rough surface substrate. Or to form a high quality color image with reduced severe image defects. The printing apparatus includes a print head capable of dye diffusion printing, an image enhancement precoat and at least one dye .
A controller is provided to direct the operation of the print head coating the rate surface and an input mechanism is provided to communicate the desired image enhancement precoat and dye coverage to the controller. This printing device is used together with the transfer mechanism. The transfer mechanism provides an image-enhancing portion, which is an image-enhancing precoat that is compatible with the substrate surface, sufficient to provide and support a more uniform print surface in combination with the substrate surface; To the extent that it can be supported, it comprises an image-enhancing precoat and at least one tinted portion with a compatible dye or mixture of dyes.

The above and various other advantages and novel features of the invention are pointed out in the appended claims. However, in order to better understand the present invention, a preferred embodiment will be described with reference to the accompanying drawings.

[0037]

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings, like reference numerals refer to like parts throughout the views. FIG. 2 shows a printing apparatus constructed according to a preferred embodiment of the present invention. The printing apparatus 10 for performing thermal transfer printing on a substrate 12 that may have a rough surface 14 includes a print head element 1.
6, which responds to commands from a printer controller 18. The print head 16 according to the preferred embodiment of the present invention includes the heating element 2
0, with each of these heating elements
In response to a command from the printer controller 18, heating is performed by electric resistance. Support rollers 22 or by providing it with uniform surface, the substrate 12 is supported by empty relationships between parallel gap with respect to the heating element 20. By selectively controlling the heating element 20 on (in contact with) the print head 16, the substrate 1 can be controlled as described in more detail below.
Printer controller 1 to control the placement of images on
8.

In general, image formation in printer controller 18 is controlled using specially designed, commercially available software such as Adobe PustScript ™.

The printer mechanism in the apparatus 10 includes a color point PS CH-5504-PR10 (Seiko Instrument, USA) and a colormate PS model 40
(NEC Technologies), ColorScript 100 Model 10 (QMS), Phasor IIPXi (Tektronix), VY-5000 and VY150 (Hitachi), S3
Commercial printers such as 40 (Mitsubishi), XL7700 and SV6500 (Kodak), 4CAST (DuPont), A4JX-560 (Sharp Electronics), UP-5000 (Sony), CIP1024P (Copal), CP-2 (Nikon) May be one of However, suitable for use by the device 10 is an A4JX-560 printer from Sharp Electronics.

Substrate 12 such as paper of bond type
In order to solve the problem of printing on a rough surface 14, the present invention provides a rough surface 14 such that a surface texture and chemistry compatible with the colorant used are obtained over the surface 14 of the substrate 12. Is subjected to an image enhancement precoat.

A coating such as an image enhancing precoat 30 is shown in FIG.
Shown in As can be seen from FIG. 1, a pre-coated application ribbon 24 is located between the heating element 20 on the print head 16 and the surface 14 of the substrate 12. The pre-coated application ribbon 24
It has a heat resistance backing 26 and a precoat forming layer 28. The precoat forming layer 28 is adhered to the backing on the side of the backing 26. In addition, backing 2
6 is arranged adjacent to the surface 14 of the substrate 12. Upon heating the heating element 20 to a predetermined temperature by the printer controller 18, the area of the precoat forming layer 28 substantially equal to the surface area of the end face of the heating element 20 is soft or molten, and the precoat application ribbon It begins to adhere to the rough surface 14 of the substrate 12 with a greater force than it adheres to the backing 26 of 24.
At this point, the area of the pre-coat formation layer 28 is separated from the application ribbon 24 and
Start to attach to the surface 14 of No. 2. This region portion reaches the pixel of the precoat material 30. FIG. 1 shows the application of three adjacent pixels 32, 34, 36 of the precoat material 30. Printer controller 18
Selectively provides precoated pixels 32, 34, 36 at predetermined locations on the substrate 12 in response to a desired image to be printed on the substrate 12. This processing will be described later in detail. Optionally, one or more operations may be performed on each pixel to completely pre-coat.

Preferably, a material exhibiting thermal resistance as well as thermal conductivity is used as the backing layer 26. Examples of these materials include cellophane, polyimide films, polyester films, polyethylene films, polystyrene films.
Film, polypropylene film, capacitor paper,
There are polymer films and papers such as glassine paper, synthetic paper, and laminated paper. Preferred carriers have a thickness of about 3 microns to about 25 microns and a density of about 0.8 [gram] / [cubic centimeter] to about 1.5 [gram] / [cubic centimeter].

Preferably, the backing layer 26 of the precoat application ribbon 24 is formed of a layer of polyethylene terephthalic acid having a thickness of about 4-5 microns.

The precoat formation layer 28, ie, the precoat pixels 32, 34, 36, is preferably a wax-based composition. Examples of the composition containing the wax as a main component include vegetable waxes such as carnuuba wax, Japanese wax, Aurichly wax, and esparto wax; and animals such as beeswax, insect wax, shellac wax, and whale wax. Petroleum waxes such as paraffin wax, polycrystalline wax, ester wax, and oxidized wax; mineral waxes such as montan wax, azocellite, and ceresin; and palmitic acid, stearic acid, margaric acid, and behenic acid High fatty acids; High alcohols such as palmityl alcohol, stearyl alcohol, eicosane; High fatty acid esters such as cetyl palmitate, myryl palmitate, cetyl stearate, myryl stearate; and acetamide, propionamide, malmityl acid Bromide, stearic acid amide, oleic acid amide,
Amides such as amides and waxes; polyamides; primary and secondary fatty acid amides; ester gums, rosin / maleic acid resins; rosin derivatives such as rosin / phenolic resins and hydrogenated rosins; rosin / esters; High molecular compounds such as resins, terpene resins, synchropentadiene resins, and aromatic resins having a melting point of about 40 to 120 degrees Celsius; high amines such as stearylamine, behenylamine, and palmitamine; and polyethylene glycol 40
00, polyethylene glycol 6000 and the like. These materials may be used independently or in combination to form a main component for a thermal wax transfer ink useful in the practice of the present invention.

The precoat forming layer 28 is preferably between 7 and 15 microns in thickness and is formed from a mixture of carnauba wax, paraffin wax, polycrystalline wax and ethylene vinyl acetate (EVA). The relative ratio of these components in the precoat forming layer 28 is shown in FIG.
And 4 will be described later in detail.

In FIG. 3, it can be seen that the rough surface 14 of the substrate 12 can be regarded as a series of alternating peaks 38 and valleys 40. According to the embodiment of FIG. 3, each precoated pixel 42 has a valley 4 of the rough surface 14 between adjacent peaks 38.
0 to form a complete bridge and a valley 40 between the peaks
Pre-coated material 30 so as to remove substantial space of
Is blended. Therefore, a more uniform colorant receiving surface can be formed than the rough surface 14.

In order to achieve the full bridging effect shown in FIG. 3, the precoat material 30 is preferably about 0-3.
5% carnauba wax, 20-40% paraffin wax, 20-40% polycrystalline wax and 15-25
% Of EVA.

More preferably, the full-bridge precoat material 30 comprises about 30% carnauba wax, 20%
Of paraffin wax, 30% polycrystalline wax and 20% EVA.

As can be seen from FIG. 3, the first colorant layer 44 may be provided directly on the upper colorant receiving surface of the first (left) precoat pixel 42. A second colorant layer 46 is provided over the first colorant layer 44 to apply a desired color over the area of the substrate 12 covered by the first precoat pixel 42. Instead, a second (right) pre-coat
As shown with reference to pixel 42, a third colorant layer 48 of the final color of interest is provided without further colorant application.
It may be coated directly on the colorant receiving surface of the second precoat pixel 42. By providing a desired combination of the three primary colors (cyan, magenta and yellow), a wide range of colors can be represented. Alternatively, color mixing from various known dither techniques can be used to form a comprehensive color image on the colorant receiving surface of each precoated pixel 42.

Referring to FIG. 4, a partially-completed precoated pixel 5 constructed according to a second embodiment of the present invention
0 is applied to the rough surface 14 of the substrate 12. Each pre-coated pixel 5 to partially fill the valley 40
Zero is applied to the rough surface 40 and some space in the valleys 40 is removed, creating a partial bridge effect between the peaks. The embodiment of FIG. 4 configured as a preferred embodiment is shown in FIG.
The colorant layers 44 and 48 are bonded more effectively than the bridge type precoat shown in FIG. Based on that compound, it adheres to the rough surface 14 of the substrate 12 with slightly less force than the precoated pixel 42 of the embodiment of FIG. This is clearly because the precoat of the embodiment of FIG. 3 contains a thicker EVA than the precoat shown in FIG.

Preferably, the precoated pixel 50 of the embodiment of FIG. 4 has a 20-60% carnauba wax,
Contains 60% paraffin wax, 0-30% polycrystalline wax, 5-20% ethylene vinyl acetate (EVA). The most preferred compound is about 4
Consists of 0% carnauba wax, 40% paraffin wax, 10% polycrystalline wax, 10% ethylene vinyl acetate (EVA).

[0052] Figure 5 shows that coating the colorant pixels 5 4 on the form of underlay precoat pixels 32 applied to precoating process shown in FIG. The pre-coated pixel 32 may be of the embodiment of FIG. 3 or FIG. The same print head 16 and printer controller 18 used to apply the precoat material are preferably used to provide the colorant pixels 54. Indeed, the preferred embodiment of the present invention provides a single pre-coated application ribbon 24.
And a continuous web of ribbons containing four repeats of three colorant application ribbons 52 of three primary colors, or one pre-coated application ribbon 24
And a continuous web of ribbons containing five repeats of four colorant application ribbons containing three primary colors plus black. By removing the continuous web of ribbon with respect to the print head 16, the precoat and subsequent colorant layer can be removed from the substrate 1 with minimal mechanical operation.
2 on top.

Alternatively, a printer including two print heads, one covering the pre-coated pixels and the other one covering the ink or dye, can be used in the practice of the present invention. If the diffusion temperature of the colorant is different from the diffusion temperature of the precoat, or if a high print speed is desired,
Such dual print heads are most often used.

Referring again to the illustrated embodiment. A colorant application ribbon 52 is disposed between the linear array of heating elements 20 on the print head 16 and the target pre-coated pixels 34 on the substrate 12. As can be seen from FIG. 5, the colorant application ribbon 52 includes a backing layer 56 and a colorant forming layer 58.

As described above with reference to the backing layer 26, a material exhibiting thermal resistance and thermal conductivity is preferably used as the backing layer 56. Examples of this material include cellophane, polyamide films, polyester films, polyethylene films, polystyrene films, polypropylene films, capacitor papers, polymer films such as glassine paper, synthetic paper, laminated paper, and paper. The preferred carrier thickness is from about 3 microns to about 25 microns, and the density is about 0.8 [gram] /
From [cubic centimeter] to about 1.5 [gram] / [cubic centimeter].

Various thermal wax transfer ribbons are known and are commercially available. For example, product numbers CH721U and CH730U (Seiko Instruments), 50
-080 and 50-081 (NEC Technologies),
805T13-10C3H and 805T-10C4H
(QMS), 016-0906-01 and 016-09
06-00 (Tektronix) and the like are known. Wax transfer inks useful in embodiments of the present invention contain at least one colorant based on wax. Various colorants commonly used for thermal wax transfer printing are:
The present invention is more effective. For example, the coloring agent is as follows.

The yellow colorant is C.I. I. Pigments such as CI Pigment Yellow 10, 12, 16, 31, 36, 37; I. Dyes such as Solvent Yellow 34 and dyes described below.

The magenta colorant is C.I. I. Pigments such as CI Pigment Red 5, 49, 57: 1, 60, 81 and 83; I. Dyes such as Solvent Red 49 and dyes described below.

Cyan colorants include C.I. I. Pigments such as CI Pigment Blue 2, 15 and 17; I. Dyes such as Solvent Blue 4 and dyes described below.

The black colorant used in the present invention is C.I. I. Pigment Black 6, 7 and 18, C.I. I. Solvent Black 7 and the like. For purposes of this description, black is considered one color.

Similarly, various wax binders and other wax-based components commonly used in thermal wax transfer printing can be used in accordance with the present invention. Examples of wax-based ingredients are carnuuba wax,
Nippon Wax, Aurichly Wax, Espart
Vegetable wax such as wax; animal wax such as beeswax, insect wax, shellac wax, whale wax; petroleum wax such as paraffin wax, microcrystalline wax, ester wax, oxidized wax; montan wax; Mineral waxes such as azocellite and ceresin; palmitic acid, stearic acid, margaric acid,
High fatty acids such as behenic acid; high alcohols such as palmityl alcohol, stearyl alcohol, and eicosane; high fatty acid esters such as cetyl palmitate, myricyl palmitate, cetyl stearate, myricyl stearate; and acetamido and propion Amides such as acid amide, malmitylamide, stearamide, oleic amide, amide wax; polyamide;
Primary and secondary fatty acid amides; ester gums, rosin / maleic acid resins; rosin derivatives such as rosin / phenolic resins and hydrogenated rosins; rosin / esters; phenolic resins, terpene resins, synchropentadiene resins;
Polymer compounds having a melting point of about 40 to 120 degrees Celsius such as aromatic resins; high amines such as stearylamine, behenylamine, and palmitamine; and polyethylene oxides such as polyethylene glycol 4000 and polyethylene glycol 6000. These materials may be used independently or in combination to form a main component for a thermal wax transfer ink useful in the practice of the present invention.

[0062] The wax base for thermal wax transfer printing optionally includes components that promote heat-induced ink conductivity, such as softening agents, extended pigments, and the like. If necessary, by using a softening agent, a thermal transfer print head heating element is at approximate temperatures of operation, thermal wax transcription ink to ensure that melt. Suitable softening agents include mineral oil resins, polyvinyl acetate, polystyrene, styrene-butadiene copolymer, cellulose esters, cellulose ethers, acrylic resins,
It contains substances that cause heat-induced melting at the print head heating element temperature, such as lubricating oils such as mineral oil. EV
A may be used. The softening agent is preferably at a concentration of about 3% to 25%, based on the total dry weight of the thermal wax transfer ink.

Examples of suitable (ie, transparent) extender pigments for improving the transfer of molten ink are magnesium carbonate, calcium carbonate, kaolin clay, sericite, and precipitated silica. Less than about 10%, preferably about 2%, based on the total dry weight of the thermal wax transfer ink.
The filler pigment is used at a concentration of from about 10% to about 10%.

Preferred thermal wax transfer inks include about 1% to about 20% colorant, about 20% to about 80% wax binder, about 3% based on the total dry weight of the hot wax transfer ink. From about 25% of a softening agent. The hot wax transfer ink is coated on a carrier, preferably the configuration described below. Hot melt coating,
Treatments such as soluble coatings are used for this purpose. The thickness of the coated thermal wax transfer ink layer is generally less than about 20 microns, from about 1 micron to about 1 micron.
0 microns is preferred.

Preferably, the pre-coated pixel 32,
The wax-based colorant forming layer 58 of the application ribbon 52 is blended to have a lower melting point than the melting points of 34 and 36. This means that during the coating of the colorant, the structure associated with the melting is reduced to the pre-coated pixels 32, 3
4, 36 is prevented. A comparison of the optimal compound of the precoat material with the compound of the colorant material shows that the precoat material accounts for a high proportion of the carnauba wax. Here, carnauba wax has a higher melting point than paraffin wax or polycrystalline wax. Thereby, the melting point of the precoat component becomes higher than the melting point of the colorant component.

Further, the thickness of the precoat forming layer 28 is
Preferably, it is thinner than the colorant forming layer 58. This increases the strength of the coated pre-coated pixels 32, 34, 36 against the coating colorant clumps, thereby preventing the pre-coat from being severely damaged which affects overall image quality.

The viscosity of the precoat material is preferably higher than the colorant material. The optimal precoat compound viscosity is about 250-300 centipoise at 100 degrees Celsius. At the same temperature, the optimal colorant viscosity is about 100 centipoise. The viscous precoat makes the precoat pixels 32, 34, 36 more stable so that the colorant can be coated without deformation. The low viscosity colorant makes it easier to set into the precoat.

The colorant forming layer 58 preferably has a thickness of 1 to 20.
% Ink or migration, 3-10% softening agent , 70-90% wax binder. Optimally, the colorant forming layer comprises about 60% paraffin wax, 20% carnauba wax, 5% EVA to provide tack as a softening agent, 10% polycrystalline wax and 5% colorant. Including. Colorant layer 58 is preferably about 3 microns in thickness.

In operation, printer controller 18 instructs heating element 20 to heat an area of colorant application ribbon 52 to a predetermined temperature. This area is
It corresponds to the end face area of the heating element 20. At this predetermined temperature, the colorant forming layer 58 melts and adheres itself to the target precoated pixel 34. Preferably,
The forming layer 58 does not actually melt.

The printed matter formed by the above-described processing and transmitting information to the observer includes the substrate 12, the image emphasizing precoat applied to the substrate 12 by the individual pixels 32, 34, and 36, and the corresponding number of printed materials. Pre-coat
And at least one colorant pixel 54 provided to pixel 34. At least one of the precoated pixels 32, 34, 36 is positioned immediately adjacent to each precoated pixel having a colorant pixel 54, and the precoat is applied to pixels that are not immediately adjacent to the precoated pixel to which the colorant is applied. Pre-coated pixels 32, 34, 36 are not applied to substrate 1
2 above. According to a preferred embodiment of the present invention, each precoat pixel having a colorant pixel 54 is surrounded by adjacent precoat pixels 32, 36, thereby forming a precoat boundary around each colorant pixel.

Another apparatus and method for applying a colorant to the target precoated pixel 34 is shown in FIG. This figure 6
As can be seen, a dye-diffusing colorant application ribbon 60 is disposed between the linear array of heating elements 20 on the print head 16 and the target pre-coated pixels 34. The colorant application ribbon 60
It includes a backing layer 62 and a dye diffusion carrier layer 64. When heated, it dyed soaked in career layer 64
The material diffuses into adjacent target pre-coated pixels 34. Colorant application ribbon 6
By varying the temperature and time at which the zeros are exposed to the heating element 20, the amount of dye diffused into the target pre-coated pixels 34 can be more accurate than is possible with the wax transfer technique used in the embodiment of FIG. Can control. In an optimal embodiment of operation, the dye diffusion printing process is as follows. One rough paper 12 is placed in a dye diffusion printer having a continuous carrier ribbon. On this, an image enhancing substance, a yellow dye, a magenta dye, and a cyan dye are arranged in a repeating unit in the longitudinal direction. Partial heating is provided by heating elements of the print head 16 to provide complete or selective coating of the substrate to the image-enhancing pre-coated ribbon. Heating the elements of the print head heats the continuous yellow, magenta, and cyan dye / carrier ribbon sections, causing partial heating to produce an image on the substrate surface 14.

Preferably, the precoat material used in the dye diffusion embodiments of the present invention can be coated on a rough substrate surface by a conventional or slightly modified dye diffusion printer. Dye diffusion and thermal wax transfer printers operate in the same way (i.e., using partial heating for coating), so wax-based or other substantially the same image enhancing precoats Can be coated.

If the dye and precoat exhibit substantially different migration and melting temperatures, control of the print head heating element temperature will be required. More specifically, different temperatures are required to melt coat the image enhancing precoat than is necessary to transfer coat the dye. In such embodiments of the invention, a dual head temperature, dual head or other suitable device may be used.

For the dye diffusion embodiment of the present invention, the image enhancing precoat must be compatible with the dye used together. In this state, the term "compatibility" implies the ability to physically or chemically interact with the dye to produce a brightly colored image. Dispersion of the molecular weight II of the dye results in an image having this desirable color brightness characteristic. The dye molecules preferably adhere to each other because of the inability of molecular dispersion. The paper substrates used in the practice of the present invention have no room for their molecular dye dispersion. As a result, the dye is preferably wettable or forms an image enhancing precoat and a solid-in-solid solution of the dye diffusion embodiments of the present invention. Dye diffusion in an image enhancement precoat is similar to the processing that occurs between, for example, a dye and a polymer film.

Thus, the image-enhancing precoat in this embodiment of the present invention is partially selected based on dye solubility or wettability. Dye-in-solids solutions that form substances such as organic polymers, polyamide waxes, etc. are, for example, image-enhancing precoats for practical embodiments in the present invention.

Further, the image enhancing precoat may contain one or more additives capable of dye diffusion. For example, fine particles such as finely divided polymer particles may be dispersed in an image enhancing precoat such as a low melting adhesive compound (eg, polyamide, wax, etc.). For example, polyester particles having a diameter of about 10 microns or less may be used in the practice of the present invention. By applying an appropriate amount of heat, the dye migrates out of the carrier and molecularly diffuses into the precoat containing such particulate matter, resulting in a light colored image on the substrate. The substrate itself
It is difficult to accept such a dye dispersion.

In the practice of the present invention, the thickness of the precoat layer containing fine particles disposed on the substrate is determined by factors such as the level of the amount of fine particles added. Generally, as the concentration of particulate matter in the precoat material increases, the thickness of the layer required to produce a solid-in-solid solution decreases. The amount of dye that is coated anywhere affects the physical lower limit of the precoat (ie, the layer must be thick enough to allow for particulate loading and dye diffusion). Also, the desirability of the predictable color optical density dictates at least some of the precoat thickness parameters. Thicker layers are preferred for this purpose because the prediction of optical density is a function of the uniformity of the precoat layer, among other things. Since the chemical and physical structures of the dye and precoat components are known or ascertainable, conventional microparticles can prepare and implement an image enhancing component or precoat useful in the dye diffusion embodiment of the present invention.

Another important concept of the present invention is shown in FIG. As can be seen from FIG. 7, the area of the substrate 12 that is wider than the area to be coated with the colorant is provided with the precoat material according to the invention, but not over the entire surface of the substrate 12. Thereby, a remarkable change appears in the surface texture of the substrate 12. More particularly, a preferred embodiment of the present invention provides an image enhancement precoat for each predetermined pixel on the substrate on which the colorant is to be placed, and also for at least one pixel immediately adjacent to each such predetermined pixel. An apparatus and a method for performing the method are provided. However, pixels that are not one of the predetermined pixels or pixels that are not immediately adjacent to one of the predetermined pixels are not subjected to the image enhancement precoat. As a result, the precoat can be more reliably adhered to the substrate without unnecessarily wasting the precoat or changing the apparent surface texture of the substrate.

According to the preferred embodiment of the present invention, the image enhancement pre-coat is applied to each pixel immediately adjacent to each pixel to be coated with the colorant, so that the pre-coat around each pixel to be coated with the colorant is performed. To form a boundary.

To accomplish this processing, the printer controller 18 first determines where to place the colorant and underlying image enhancement precoat on the substrate on a pixel-by-pixel basis. In FIG. 10, this step is called "shadow
Create mask ". Also, the printer controller 18
Determines where to place the additional exposure precoat adjacent to the underlying image enhancement precoat in pixel units. In FIG. 10, this second step is called “Create surroundings”.
As shown. Next, the printer controller 18 determines for each predetermined pixel of the substrate where the colorant is to be placed, and
An image enhancement precoat is applied to at least one additional pixel adjacent to each area where the colorant pixel is to be located. Next, the printer controller 18 instructs the undercoat precoat to coat the colorant.

As a third step, the printer controller 18
To adjust the peripheral pattern based on the shape of the shadow mask. In FIG. 10, this step is indicated as “filling a gap”. For example, in a region where the colorant is to be distributed sparsely, the step of filling the gap applies a precoat as well as pixels immediately adjacent to the pixel to be coated with the colorant. In regions with high density, the precoat boundary region may be reduced.

As an example of the preferred embodiment, the printer controller 1
8, first, as shown in FIG. 7, it is determined that the pixel (G, 8) is to be coated with the colorant as a part of the shape of the character "E". When the printer controller 18 makes such a determination,
The printer controller 18 controls each pixel adjacent to pixel (G, 8), ie, pixels (F, 7), (F, 8),
(F, 9), (G, 9), (H, 9), (H, 9),
It is determined that (H, 7) and (G, 7) are to be precoated. When the printer controller 18 makes this determination, it instructs the apparatus 10 to apply a pre-coat to a given pixel. In the illustrated embodiment, the step of filling the gap does not change the shape of the precoat boundary. Subsequently, the colorant is applied to the preselected pixels (G, 8). The printer controller 18 may execute this processing line by line or region by region. Alternatively, the present invention can apply a precoat to a wide area that is larger than immediately adjacent pixels.

The print shown in FIG. 7 comprises a substrate 12, an image enhancing precoat applied to the substrate in individual pixels 32, 34, 36, and at least one precoat pixel 34 applied to a corresponding number of precoated pixels 34. And a colorant pixel 54. Pre-coating is performed on at least one pre-coated pixel immediately adjacent to each pre-coated pixel having a colorant pixel, and on pixels that are not immediately adjacent to the pre-coated pixel provided with the colorant. Pre-coated pixels are arranged on the substrate so that they do not exist. Optimally,
Each pre-coated pixel 3 having a colorant pixel 54
4 forms a precoat boundary around each colorant pixel, as it is surrounded by adjacent precoat pixels 32,36. According to the embodiment of the present invention shown in FIG. 5 or FIG. 6, a coloring agent can be applied.

8 and 9, the prints 66 and 80 according to the present invention include a substrate 12 and an image emphasizing pre-coat 42 adhered to the substrate 12.
50, a precoat including a colorant receiving surface having at least one gap, and a colorant adhered to the colorant receiving surface. Colorants 78, 88 are formulated and coated to bridge across the gap in the colorant receiving surface.

In FIG. 8, it can be seen that the rough surface 14 and the substrate 12 include adjacent peaks 68, 70, 72. The peaks 68, 72 are substantially higher than the peak 70 and are located between the peaks 68, 72. Due to this height difference, while being configured and compounded according to the embodiment of FIG. 3,
The pre-coated pixel 42 bridging the adjacent peaks 68, 70, 72 falls slightly downward and adheres to the second peak 70 between the peaks 68, 72. As a result, the Precor door 4 2
And a resulting gap 76 between the colorant 7 8. The coloring agent 78 is blended so as to bridge the gap 76 without causing harmful effects such as cracks and breakage.

[0086] Similarly, FIG. 9 shows a printing substrate 80, precoat material is formulated by the embodiment of FIG. 4, a Precor bets 5 0 coated. Precor door 5 0
The drop in the valley of the substrate 12, in order to accommodate the rough surface 14, precoat pixels 50 and a colorant
The gaps 84 and 86 are formed between 88. Again, the gaps 84, 8 can be provided without detrimental effects such as cracks and breaks.
A coloring agent is blended so as to bridge No. 6.

While numerous features and advantages of the present invention have been described above in conjunction with the detailed structure and function of the present invention, various modifications, such as shape, size, and arrangement, may be made without departing from the spirit of the invention. Can be changed.

[0088]

As described above, according to the present invention, thermal transfer printing can be reliably performed on a rough substrate such as bond paper, and the rough appearance and feel of the substrate in an area where no image is printed can be maintained. be able to.

[Brief description of the drawings]

FIG. 1 is a view showing a configuration in which a precoat material is applied on a substrate in an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram of a printing apparatus according to a preferred embodiment of the present invention.

FIG. 3 is a diagram showing a state in which a first type of precoat of the present invention is applied to an underlay substrate.

FIG. 4 is a view showing a state in which a precoat of the second type of the present invention is applied to an underlying substrate.

FIG. 5 is a view showing a configuration in which a wax transfer type colorant is applied on a precoated substrate according to the present invention.

FIG. 6 is a diagram showing a configuration in which a colorant is applied to a precoated substrate by a dye diffusion process.

FIG. 7 illustrates a novel method of applying a precoat on a substrate, according to one aspect of the present invention.

FIG. 8 shows a novel colorant material according to the present invention with a pre-coated material according to the embodiment of FIG. 3;

9 illustrates the colorant material of FIG. 8 overlying the precoat material provided by the embodiment of FIG.

FIG. 10 illustrates a flowchart according to one aspect of the invention.

[Explanation of symbols]

 12 Substrate 14 Rough Surface 16 Print Head 18 Print Controller 20 Heating Element 22 Support Roller 24 Precoat Application Ribbon 26 Thermal Resistance Backing 28 Precoat Forming Layer 30 Precoat Material 32, 34, 36 Pixel

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor B. J. Bareson 98684, Washington, USA South East One Handed Fifty Ace Loop 2016 (72) Inventor Thomas J. Brand Oregon, U.S.A. Canby North East Twelfth Avenue 400 (56) References JP-A-60-131282 (JP, A) JP-A-63-237988 (JP, A) (58) Fields studied (Int. Cl. ⁶ , (DB name) B41J 2/32-2/325 B41M 5/26

Claims (4)

(57) [Claims] 1. A method of performing thermal transfer printing on a rough surface substrate having peaks and valleys, comprising locally heating and applying an image enhancing precoat.
More, subjected to the image emphasis precoat to the rough surface, the upper
While leaving a space in the valley between the serial crests form a complete bridge straddling across the valleys between peaks adjacent the rough surface, than the rough surface to form a uniform colorant receiving surface, already A thermal transfer printing method comprising coating a colorant on the colorant receiving surface of the coated image enhancing precoat. 2. Substrate with a rough surface having peaks and valleys.
A method of performing thermal transfer printing on a sheet, which involves locally heating and coating an image emphasis precoat.
Apply the image emphasis pre-coat on the rough surface
The valley above the rough surface, leaving a gap in the valley between the peaks
And partially bridge the peaks above to achieve a partial bridge effect.
To form a more uniform colorant receiving surface than the rough surface
On the colorant receiving surface of the previously coated image-enhancement precoat
Thermal transfer printing method characterized by coating a colorant on the surface
Law. 3. An apparatus for performing thermal transfer printing on a rough surface substrate having peaks and valleys, the method comprising locally heating and applying an image enhancing precoat.
More, subjected to the image emphasis precoat to the rough surface, the upper
The full bridge is formed straddling across the valley of the Minema of the rough surface while leaving a space in the valley between the serial crests
Te, the coarse means for forming a uniform colorant receiving surface than the surface, the thermal transfer printing apparatus and means for covering the color of the colorant already coated the image enhancing precoat colorant receiving surface. 4. Substrate with a rough surface having peaks and valleys.
This is a device that performs thermal transfer printing on a sheet , and heats it locally to cover the image emphasis precoat.
More subjects on Symbol image enhancing precoat to the rough surface, the upper
The valley above the rough surface, leaving a gap in the valley between the peaks
And partially bridge the peaks above to achieve a partial bridge effect.
To form a more uniform colorant receiving surface than the rough surface.
Means on the colorant receiving surface of the image-enhancement precoat already coated
Transfer pre- coating means for coating a colorant on the surface
Equipment.