JPH08169129A - Image forming method - Google Patents

Abstract

PURPOSE: To provide a method for forming an image in which an image formed matter in which the image is formed by a sublimation transfer type on the entire surface without a margin at the end side can be easily and efficiently obtained. CONSTITUTION: Heat is applied by a thermal head 7 having larger maximum recording width than an image receiving sheet 1 from the back surface of a heat transfer sheet 4 in the state that the sheet 1 is superposed with the sheet 4 having larger maximum recording width than the sheet 1 to sublimate and transfer dye from the dye layer of the sheet 4 on the sheet 4, thereby forming an image on the entire area of the sheet 1 in the width direction as an image forming area A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method, and more particularly to an image forming method for an entire image receiving sheet by a sublimation transfer method.

[0002]

2. Description of the Related Art Conventionally, when various kinds of images are formed by a sublimation transfer method, a thermal transfer sheet having a dye layer provided on one surface of a base film has been used. This thermal transfer sheet comprises a base film having heat resistance, and a dye layer formed by applying and drying an ink in which a sublimable dye is mixed with a binder on the base film. And
Heat is applied from the back side of the thermal transfer sheet by a thermal head to transfer a large number of three-color or four-color dots to the image-receiving sheet to form a full-color image. The formed image is clear and excellent in transparency because the coloring material used is a dye, and has high reproducibility of intermediate colors and gradation, and it is possible to form high-quality images equivalent to conventional full-color photographic images. is there. As a result of being able to form high-quality images by the sublimation transfer method, it has come to be used as a substitute for silver halide photography. In this case, it is required to form an image on the entire surface of a sheet. .

[0003]

Conventionally, when an image is formed by sublimation transfer on the entire surface of a sheet, the maximum recording width of the thermal head is set smaller than the width of the image receiving sheet, and the width of the recording sheet is smaller than the width of the image receiving sheet. After forming the image in the area,
After the image formation, the image receiving sheet is cut inside the four edge sides of the image area to obtain a printed matter on which an image is formed up to the edge sides.

However, the cutting process of the image-receiving sheet after image formation is extremely complicated in the case of manual work,
Further, when the cutting process is incorporated inline in the image forming process, a slitting device in the width direction is required in addition to the cutting device in the flow direction of the image receiving sheet, which causes a problem that the manufacturing cost of the image forming apparatus increases. . Further, perforations for cutting are formed in advance in the image forming areas of both widths of the image receiving sheet, and both end portions of the sheet obtained by being cut in a predetermined length in the flow direction are obtained from the above perforations. When separated, the manual cutting is slightly simplified, but it is necessary to form perforations at both ends in the width direction of the image receiving sheet in the image receiving sheet manufacturing process, which increases the image receiving sheet manufacturing cost. There is a problem of doing.

Further, as described above, when the image receiving sheet is cut inside the four edge sides of the image area after the image is formed to obtain a sheet on which an image is formed on the whole, a cut removed portion at both ends in the width direction of the image receiving sheet is obtained. However, it is necessary to use an image-receiving sheet that is wider than the intended sheet, and there is a problem that running costs are hindered.

The present invention has been made in view of such circumstances, and easily and efficiently obtains an image-formed product on which an image is formed by a sublimation transfer method on the entire surface without forming a blank portion on the edge. An object of the present invention is to provide an image forming method that enables the above.

[0007]

In order to achieve such an object, the present invention provides a thermal head from the back surface of the thermal transfer sheet by superposing a dye layer and an image receiving sheet provided on the surface of the base film of the thermal transfer sheet. In the method of forming an image by sublimating and transferring the dye from the dye layer onto the image receiving sheet by applying heat, the width of the thermal transfer sheet and the maximum recording width of the thermal head are set to be larger than the width of the image receiving sheet. The image forming area is formed over the entire width of the image receiving sheet.

According to the present invention, the image receiving sheet is a long body, and after the image is formed, the image receiving sheet is cut at the end portion in the flow direction of the image forming area to form a sheet on which an image is formed on the entire surface. It was configured like this.

Further, according to the present invention, the heat generation of a portion of the thermal head located outside the image receiving sheet is suppressed more than that of other portions.

Further, according to the present invention, a platen roller is arranged so as to face the thermal head through the thermal transfer sheet and the image receiving sheet, and the width of the platen roller is made larger than the width of the image receiving sheet. And

[0011]

[Function] With the image receiving sheet and the thermal transfer sheet being overlaid,
An image is formed on the image receiving sheet by sublimating and transferring dye from the dye layer of the thermal transfer sheet to the image receiving sheet by applying heat from the back surface of the thermal transfer sheet, but the width of the thermal transfer sheet and the maximum recording of the thermal head Since the width of the image receiving sheet is larger than the width of the image receiving sheet, the image receiving sheet is formed as an image forming area over the entire width direction thereof, and a margin portion in which an image cannot be formed does not occur at an edge portion in the width direction. Further, the image receiving sheet is elongated, and after the image is formed, the image receiving sheet is cut at the end in the flow direction of the image forming area to form a printed matter having an image formed on the entire surface, and heat generated in one row of the thermal head. By suppressing the heat generation in the portion of the resistor located outside the image receiving sheet more than in other portions, it is possible to prevent the platen roller from being contaminated by the dye sublimated from the dye layer that does not participate in image formation.

[0012]

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

FIG. 1 is a plan view for explaining the image forming method of the present invention, and FIG. 2 is an enlarged vertical sectional view taken along line II-II of FIG. 1 and 2, the image receiving sheet 1 in which the dye receiving layer 3 is provided on one surface of the base sheet 2
And the thermal transfer sheet 4 having the dye layer 6 provided on one surface of the base film 5 in such a state that the dye receiving layer 3 and the dye layer 6 are overlapped so as to face each other, the thermal head 7 and the platen roller 8 It is sent to the space opposite to. Then, based on the image data for sublimation transfer, heat is applied from the back side of the thermal transfer sheet 4 by the thermal head 7 to sublimate and transfer the dye from the dye layer 6 onto the dye receiving layer 3 of the image receiving sheet 1 to thereby transfer the image onto the image receiving sheet 1. An image is formed on.

According to the image forming method of the present invention, the maximum recording width W2 of the thermal transfer sheet 4, the maximum recording width W3 of the thermal head 7 and the width W4 of the platen roll 8 with respect to the width W1 of the image receiving sheet 1 are as follows. Both are set large. Therefore, in the image formation by the sublimation transfer method as described above, the entire area of the width W1 of the image receiving sheet 1 is defined as an image forming area (area A indicated by diagonal lines in FIG. 1), and an edge portion in the width direction. There is no blank area where an image cannot be formed. Therefore, the image receiving sheet 1 which has passed through the space where the thermal head 7 and the platen roller 8 face each other and has completed the image formation by sublimation transfer has an image formed on its entire width, and when forming an image on the entire width of the conventional case. It becomes unnecessary to cut the edge portion in the width direction of the image receiving sheet which is necessary for the above. Thereby, the image receiving sheet having a desired width can be efficiently used, and
An image-formed product having an image formed by the sublimation transfer method over the entire width direction can be easily obtained.

Further, both ends 7a, 7a of the thermal head 7 which are located outside the image receiving sheet 1 perform so-called idle transfer, but the both ends 7a, 7a.
The heat generation may be suppressed more than the heat generation in other portions (the portion facing the image receiving sheet 1 via the thermal transfer sheet 4). As a result, it is possible to prevent the dye sublimated from the dye layer 6 that is not involved in image formation from adhering to the surface of the platen roller 8 and causing contamination.

As described above, in the present invention, the maximum recording width W2 of the thermal transfer sheet 4 and the maximum recording width W of the thermal head 7 are set.
3 and the width W4 of the platen roll 8 need only be larger than the width W1 of the image receiving sheet 1, W2, W4, W
The magnitude relationship of 3 is arbitrary.

In the image forming method of the present invention shown in FIGS. 1 and 2, the image receiving sheet 1 is a long sheet, and in the width direction, the image is formed in the full width as described above. In order to obtain a sheet-shaped image formed product on which the image is formed, the image receiving sheet 1 may be cut at the end portion in the flow direction of the image forming area of the image receiving sheet 1. That is, when the margin B is provided between each image forming area A in the flow direction of the image receiving sheet 1 (FIG. 3), the image forming area A
The image receiving sheet 1 may be cut at both ends a, a in the flow direction. Further, when there is no margin between the image forming areas A in the flow direction of the image receiving sheet 1 (FIG. 4), the image receiving sheet 1 may be cut at the boundary b between the image forming areas A.

Further, in the image forming method of the present invention, it is possible to use a single sheet as the image receiving sheet. In this case, a grip area for conveying the image receiving sheet is required, and image formation cannot be performed only in this grip area. Therefore, in order to obtain a sheet-shaped image forming sheet on which an image is formed on the entire surface, it is necessary to cut and remove the blank portion corresponding to the grip area after image formation.

The image-receiving sheet 1 used in the image forming method of the present invention may be the image-receiving sheet used in the conventional image formation by the sublimation transfer method, and is not particularly limited. That is,
As the material that can be used for the base sheet 2 that constitutes the image receiving sheet 1, various types of paper such as simple paper or processed paper can be used. For example, high-quality paper, art paper, coated paper, cast coated paper, paperboard, In addition to wallpaper, backing paper and the like, impregnated paper with resin emulsion, synthetic rubber latex and the like, synthetic resin internal addition paper and the like can be mentioned. Further, laminated paper of these and various plastic films can also be used.

As the synthetic paper, polystyrene-based synthetic paper, polyolefin-based synthetic paper and the like can be favorably used, and as the plastic film, the polyolefin-based resin film,
Polyvinyl chloride film, polyester resin film, polystyrene film, polymethacrylate film, polycarbonate film, polyacrylonitrile film and the like can be used. For these plastic films, not only a transparent film but also a white opaque film formed by adding a white pigment, a filler or the like, or a foamed film can be used, and there is no particular limitation.

When a plastic film is used, a plasticizer or the like may be added if necessary in order to adjust the rigidity of the film.

The above materials for the base sheet 2 may be used alone, or may be used as a laminate in combination with other materials.

The thickness of such a base sheet 2 can be appropriately determined according to the required strength and the like, for example, 1
It can be about 50 to 250 μm.

The dye receiving layer 3 constituting the image receiving sheet 1 is for receiving the sublimable dye transferred from the thermal transfer sheet 4 and maintaining the formed image. As the resin for forming the dye receiving layer 3, known resins can be used and are not particularly limited, and examples thereof include polyester resin, polyacrylic ester resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, vinyl. Resins having ester bond such as toluene acrylate resin, resins having urethane bond such as polyurethane resin, resins having amide bond such as polyamide resin, resins having urea bond such as urea resin, or polycaprolactone resin, styrene-anhydrous Examples thereof include resins having a highly polar bond such as maleic acid resin, polyvinyl chloride resin and polyacrytonitrile resin. Further, a mixture or copolymer of the above resins can be used. Usually, the thickness of the dye receiving layer 3 is 0.5 to 1
It can be about 0 μm.

During sublimation transfer, the dye-receiving layer 3 is heated and pressure-bonded together with the thermal transfer sheet by a thermal head or the like, so that it easily sticks to the surface of the thermal transfer sheet, and the dye-transmitting layer usually passes through the resin as described above. It is formed by containing a mold release agent. Examples of such a release agent include solid waxes, fluorine-based or phosphoric acid ester-based surfactants,
Silicone oils and the like are used. In particular, as the silicone oils, oily ones can be used, but reaction-curable ones are preferable, for example, a combination of amino-modified silicone and epoxy-modified silicone is preferable.

An antistatic agent may be added to the dye receiving layer 3. The antistatic agent to be used is a known antistatic agent, for example, a quaternary ammonium salt, a cationic antistatic agent such as a polyamine derivative, an anionic antistatic agent such as an alkyl phosphate, and a nonionic antistatic agent such as a fatty acid ester. Is mentioned.

Further, the image receiving sheet 1 may have an intermediate layer formed between the base sheet 2 and the dye receiving layer 3. Such an intermediate layer includes the base sheet 2 and the dye receiving layer 3
It is for improving adhesiveness with, and can be formed of polyurethane resin, acrylic resin, polyethylene resin, polypropylene resin, epoxy resin, or the like,
The thickness is preferably about 0.1 to 25 μm.

A bubble-containing layer may be provided between the base sheet 2 and the above intermediate layer. This bubble-containing layer can be formed by using a foaming agent, and the foaming agent used is dinitropentamethylenetetramine, diazoaminobenzene, azobisisobenzene which decomposes by heat to generate gases such as oxygen, carbon dioxide and nitrogen. Examples thereof include decomposition type foaming agents such as butyronitrile and azodicarbamide, and microballoons obtained by microencapsulating a low boiling point liquid such as butane and pentane with a resin such as polyvinylidene chloride and polyacrylonitrile.

As the thermal transfer sheet 4 used in the image forming method of the present invention, a thermal transfer sheet used for image formation by a conventional sublimation transfer system can be used. For example, a yellow dye is formed on one surface of the base film. Layer, magenta dye layer, cyan dye layer 3
A color surface sequential thermal transfer sheet is preferably used. Also,
When the protective layer is transferred after image formation for the purpose of imparting durability to the printed matter, a thermal transfer sheet provided with the yellow, magenta, and cyan dye layers as well as the protective layer can be transferred is used. Good.

The base film 5 constituting the thermal transfer sheet 4 as described above is a base film used in conventional thermal transfer sheets, for example, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polychlorinated. Plastic films such as vinyl, polystyrene, nylon, polyimide, polyvinylidene chloride, polyvinyl alcohol, fluororesin, chlorinated rubber, ionomer, glassine paper, condenser paper,
Papers such as paraffin paper and non-woven fabrics can be used.

The dye layer 6 constituting the thermal transfer sheet 4 is a layer in which a dye is carried by a binder, and the dye is a dye used in a conventional thermal transfer sheet, such as MS R.
ed G, Macrolex RedViolet R, Ceres Red HBSL, Resoli
n Red dye such as F3BS, holon brilliant yellow
Yellow dyes such as 6GL, PTY-52, Macrolex Yellow 6G, Kayaset Blue 714, Waxolin Blue AP-FW,
Blue dyes such as Holon Brilliant Blue SR and MS Blue 100 can be used. As the binder for supporting the above dye, for example, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose resins such as cellulose acetate butyrate, polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl. Vinyl resins such as acetal, polyvinylpyrrolidone, and polyacrylamide, polyesters, and the like can be given. Among these, cellulose, acetal, butyral, and polyester are preferably used in terms of heat resistance, dye transferability, and the like. can do. Incidentally, the dye layer 6 may contain various conventionally known additives, if necessary, in addition to the above dyes and binders.

[0032]

As described in detail above, according to the present invention, when the image receiving sheet and the thermal transfer sheet having a maximum recording width larger than that of the image receiving sheet are superposed, the maximum recording is performed from the back surface of the thermal transfer sheet rather than the image receiving sheet. Heat is applied by a thermal head having a large width to sublimate and transfer the dye from the dye layer of the thermal transfer sheet onto the image receiving sheet to form an image as an image forming area over the entire width direction of the image receiving sheet. There is no blank area where image formation cannot be performed on the edge portion in the width direction, and an image receiving sheet of a predetermined width can be used efficiently,
In addition, it is not necessary to remove the blank portion after the image formation, and it is possible to easily obtain an image-formed product having an image formed by the sublimation transfer method on the entire surface. Furthermore, the image receiving sheet is a long body,
After the image is formed, the image receiving sheet can be easily cut at the end of the image forming area in the flow direction to form a printed image on the entire surface. Especially effective as a print,
Further, by suppressing heat generation in the portion of the thermal head located outside the image receiving sheet as compared with other portions, it is possible to prevent the platen roller from being contaminated with dye sublimated from the dye layer not involved in image formation. it can.

[Brief description of drawings]

FIG. 1 is a plan view for explaining an image forming method of the present invention.

FIG. 2 is an enlarged vertical sectional view taken along line II-II in FIG.

FIG. 3 is a diagram for explaining cutting of an image receiving sheet at an end portion in the flow direction.

FIG. 4 is a diagram for explaining cutting of an image receiving sheet at an end portion in the flow direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image receiving sheet 2 ... Base material sheet 3 ... Dye receiving layer 4 ... Thermal transfer sheet 5 ... Base material film 6 ... Dye layer 7 ... Thermal head 8 ... Platen roller A ... Image forming area W1 ... Image receiving sheet width W2 ... Thermal transfer sheet Width W3 ... Width of thermal head W4 ... Width of platen roller

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location 7416-2H B41M 5/26 101 Z

Claims (4)

[Claims] 1. A dye layer provided on the surface of a substrate film of a thermal transfer sheet and an image receiving sheet are superposed, and heat is applied from the back surface of the thermal transfer sheet by a thermal head to sublimate and transfer the dye from the dye layer onto the image receiving sheet. In the method of forming an image, the width of the thermal transfer sheet and the maximum recording width of the thermal head are set to be larger than the width of the image receiving sheet,
An image forming method, wherein the entire area of the image receiving sheet in the width direction is used as an image forming area. 2. The image receiving sheet is a long body, and after the image formation, the image receiving sheet is cut at the end portion in the flow direction of the image forming area to form a sheet of which image is formed on the entire surface. The image forming method according to claim 1, wherein: 3. The image forming method according to claim 1, wherein a portion of the thermal head located outside the image receiving sheet generates less heat than other portions. 4. A platen roller is arranged so as to face the thermal head via the thermal transfer sheet and the image receiving sheet, and the width of the platen roller is made larger than the width of the image receiving sheet. The image forming method according to any one of claims 1 to 3.