JP3632516B2 - Image forming apparatus - Google Patents

Description

【００４９】

【００５０】
そして、サンプル−２では３回程度のプライマ転写、サンプル２では、２〜３回の転写で良好な接着強度が得られることを確認し、セロハンテープ剥離試験や学振試験等の接着特性試験でも良好な結果を得ることが出来た。
また、紙の繊維等の他にも、被転写体上に施した事前に行なうプリプリントの性能によってもプライマ転写回数を変えた方が良いことも判明した。
【００５１】
【発明の効果】
以上、本発明によれば、支持体上にプライマ層を感熱転写可能に設けてある感熱転写記録媒体を使用し、プライマ層を中間転写媒体の受像層の面に感熱転写する場合に、被転写体の被転写面の状態や性質に応じて、２回以上の適当な回数で複数回、中間転写媒体上に加熱転写できるような技術を提供し、これにより強固な最終記録画像を得る事の出来る画像形成装置を提供することが出来た。
【図面の簡単な説明】
【図１】本発明に係る画像形成装置を模式的に示す説明図。
【図２】本発明に係る１実施例で使用する感熱転写記録媒体（インクリボン）を模式的に示す説明図。
【図３】本発明に係る１実施例で使用する中間転写媒体上に、各色のインクによって感熱転写画像記録がなされたところを模式的に示す説明図。
【図４】プライマパネルによるプライマ層の感熱転写をサーマルヘッドによって、１回だけ行ったところを模式的に示す説明図。
【図５】プライマパネルの残りの部分を使って２回目のプライマ層を感熱転写したところを模式的に示す説明図。
【図６】加熱加圧された最終的な記録媒体（被転写体上に画像各層が転写されたもの）を模式的に示す説明図。
【符号の説明】
１、１‘・・・被転写体
２、２‘・・・トレイ
３ ・・・レール
４、４’、５、５’・・・車輪
６ ・・・中間転写媒体
１０ ・・・プラテンローラ
１３、１５、１６、３９ ・・・ガイドローラ
１７、１８ ・・・搬送ローラ
４０ ・・・ヒートローラ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an indirect transfer image forming apparatus that forms a dot-shaped area gradation image by thermal transfer, and more particularly to an image forming apparatus that improves the strength between an image to be formed and a transfer target.
[0002]
[Prior art]
Conventionally, as a method for writing an image on an intermediate transfer medium based on image information, in addition to the most frequently used printing method, a thermal transfer method, an electrophotographic method, an inkjet method, a thermal destruction method described in the present invention are described. Various transfer recording methods using a photopolymerization recording material can be cited as technically possible examples.
Then, it is difficult to form an image directly on the final recording medium (final product) to which an image is to be applied using these image forming methods, the mass productivity is poor, or the cost becomes high. When any problem is involved, as described above, a method is employed in which an image is first formed on an intermediate transfer medium, and then the image is applied to the final product by transfer.
[0003]
When the image forming method is, for example, a thermal transfer method using a sublimation dye, it can be a thermal recording ribbon and a final recording medium in which a sublimation dye is coated on the base film so as to be capable of thermal transfer. A desired image is transferred and recorded on the transfer body by superimposing the transfer image on the transfer body and selectively heating the thermal transfer ribbon to the transfer body based on the image data prepared using a thermal head or the like. It is widely known as a known fact.
[0004]
According to this means, when, for example, each human face is individually recorded on each transferred object, recording of a large number of different images can be easily performed on the transferred object as a color image rich in gradation. There is an advantage not seen in the case of the printing method in that it can be recorded. If such a record of each person's face or the like is to be dealt with by the printing method, it is generally very uneconomical because it requires a great deal of cost, labor and time.
However, the thermal transfer recording method using a sublimation dye has a drawback. In other words, materials that can be dyed with a sublimable material are limited, and can be applied only to a material to be transferred such as polyester, acrylic resin, vinyl chloride resin, and the like.
[0005]
Therefore, as a means for carrying out the thermal transfer recording using a sublimation dye in spite of the use of a material other than these as the material to be transferred, for example, JP-A-63-81093 In the image writing section using a sublimation dye transfer ribbon and a thermal head, an image is first written on a film-like intermediate transfer medium having an adhesive layer, and then in the transfer section. There has been proposed a system in which an image on a transfer medium is transferred to the transfer target body by applying heat and pressure to the transfer target body together with the adhesive layer using a transfer roller.
[0006]
By the way, this method is only an example of a sublimation dye, but for various reasons, an image is once formed on an intermediate transfer medium by other image writing means that cannot directly form an image on a transfer target. The method for transferring an image to a transfer medium together with the layer on which the image is formed is basically the same, and this recording method is hereinafter referred to as an indirect transfer method.
For example, direct images may be used for various reasons, such as the thickness of the transferred material that will be the final product (recording medium), unevenness, or pre-finished products such as booklets. It is not an exaggeration to say that the image can be formed only by the indirect transfer method when it is impossible to form the image on the transfer material or when it takes a lot of cost and time to form the image.
[0007]
However, when an electrophotographic method is used as a method for writing an image on the intermediate transfer medium based on image information, a latent image is formed by charging the photosensitive member or exposing the charged photosensitive member to form a full-color image. Formation, development of a toner image formed on a latent image on a photoconductor, image transfer to a transfer member for temporarily storing a toner image of each color such as a transfer drum, erasing unnecessary charged portions on the photoconductor, photoconductor It is necessary to repeat the electrophotographic process such as cleaning above etc. 3 times (3 color) or 4 times (4 color) or more, and it takes a very long time. Instability. Furthermore, since the dots of the toner image forming the image cannot be changed in size so much, it basically becomes a binarized image, and is a pseudo-area floor using a dither matrix such as Bayer type or Fatton type (including screw type). If the tone method is not used, the density change expression of the image cannot be expressed, and there is a big problem that the image itself is rough.
[0008]
Next, when the ink jet method is used, since an image is formed on the intermediate transfer medium using liquid ink, it is necessary to dry, and the problem of nozzle clogging also occurs. Furthermore, even in the case of the ink jet method, since the dot size cannot be changed so much, the resolution of the image tends to become coarse because a pseudo area gradation method such as a dither matrix or an error diffusion method is used. It is in.
And for the thermal destruction method, full-color expression is not possible at present.
For these reasons, image formation by a thermal transfer method using a sublimation dye is simple, low cost, high image quality, and high resolution can be realized. I can say that.
[0009]
However, the thermal transfer method using a sublimation dye has a major drawback. This is because the sublimation dye itself is a color material with very low resistance such as heat resistance, light resistance, solvent resistance, etc. When this sublimation dye is used, the final product on the transferred material. The image durability is very inferior. For this reason, for example, when an IC card having a heat resistant temperature of about 120 ° C. is used as the transfer target, image density reduction due to phenomena such as thermal decomposition of sublimation dyes and resublimation occurs even at about 80 ° C. It is impossible to clear the heat-resistant temperature of 120 ° C.
In addition, when paper such as passport is used as the transfer target, the image may “bleed” due to the solvent atmosphere such as paradichlorobenzene or naphthalene that is often used as an insect repellent from the back side of the paper on which the image is transferred, When the image quality is high, various problems such as a decrease in image density due to resublimation of the sublimable dye from paper fibers occur.
Furthermore, since the sublimation printing method itself is widely used in the world, when used for security purposes such as passports, fraud such as forgery and tampering tends to be easily performed, and forgery or tampering is likely to occur. However, there was also a problem that it was difficult to distinguish sincerity.
[0010]
In order to solve these unique problems of sublimation dyes and achieve simple, low-cost, high image quality and high resolution by the thermal transfer method, the size of the transferred dots depends on the amount of heat generated by the thermal head used for thermal transfer. An area gradation type fusion thermal transfer printing system that performs density gradation by changing the thickness is very effective.
For example, a colorant such as an organic dye, an organic pigment, or an inorganic pigment is internally added to a binder resin such as polymethyl methacrylate, polybutyral, or vinyl chloride-vinyl acetate copolymer, and if necessary, WAX An ink ribbon that has been pre-formed by a printing method on a support such as polyethylene terephthalate (abbreviated as PET) or polyethylene naphthalate (abbreviated as PEN) is controlled from the thermal head. This is a melt transfer system in which area gradation is possible by softening ink by the amount of heat and changing the area to be softened by the amount of heat.
[0011]
In this method, dyes or pigments other than sublimation dyes can be used as coloring materials, so it is possible to significantly improve durability, especially heat resistance, solvent resistance, and light resistance, and passports, visas, and driver's licenses. It can be said that this method has a very high requirement conformity in a field where high tolerance is required.
Originally, the area gradation type melt transfer method is very sensitive to the unevenness of the recording medium to be transferred, and if there is any unevenness, the image cannot be directly transferred and formed, so it is compatible with the indirect transfer method. In other words, in other words, it can be said that it is almost impossible to obtain a high quality image by the area gradation type melt transfer system except by the indirect transfer system.
[0012]
[Problems to be solved by the invention]
By the way, when transferring an image on an intermediate transfer medium onto a transfer medium such as paper, a thermal transfer means using heat and pressure is practical, but the image is firmly bonded to the transfer medium such as various paper media by thermal bonding. It is very difficult to do. In particular, the melt transfer image formed on the intermediate transfer medium needs to improve the gradation of the ink layer forming it, that is, reduce the thickness of the ink and improve the foil breakage of the ink layer. Therefore, the ink thickness is generally thin, and the amount of the color material component to be internally added to the ink is determined by the required maximum image density, so that the binder resin component ratio in the ink is reduced.
However, since the adhesive force between the ink layer and the transfer target is almost determined by the amount of the binder resin in the ink, when the image is directly transferred to the transfer target, the adhesive strength between the image and the transfer target is extremely high. There is a problem that it becomes low. This is a very negative point especially in fields where image security and durability are required, such as passports and driver's licenses.
[0013]
Therefore, in the ink ribbon that forms the image, a primer resin layer (hereinafter referred to as a primer panel) having adhesiveness between the transfer target, the ink layer, and the image receiving adhesive layer that is the outermost surface layer of the intermediate transfer medium is provided. After the image is formed on the intermediate transfer medium, if the primer panel is heat-bonded in an area equal to or larger than the area of the intermediate transfer medium that is heat-bonded to the transfer medium, it is heat-bonded on the transfer target Since a primer layer is formed between the image layer (made of thermal transfer ink) and the transfer target, the adhesive strength is improved.
[0014]
By the way, when paper is used for the transfer target, the paper may be made of fibers, and a primer layer having a sufficient thickness is necessary to give sufficient adhesive strength. For example, a primer layer of at least 4 μm is required for high-quality paper distributed in Japan, and a bond layer of about 6 μm is required for bond paper such as Alaska White that is distributed overseas as high-quality paper.
However, although an ink ribbon is generally produced by a coating means by a gravure printing method, it is extremely difficult to coat thickly with a thickness of 4 μm or more simultaneously with ink printing. In particular, in the gravure printing method, in order to increase the coating thickness, it is necessary to increase the depth of the intaglio plate, and the limit of the coating thickness is naturally determined, and the surface of the plate is roughened. There was a problem that it was finished on the rough and bad side.
[0015]
Even if a thick primer panel can be provided in the ink ribbon by some method, the primer panel is too thick at the time of thermal transfer from the ink ribbon by the thermal head or the like onto the intermediate transfer medium. There are various problems, such as burrs appearing at the edge of the transfer area of the primer panel, dust being generated, or, in the worst case, the primer panel does not move from the ink ribbon onto the intermediate transfer medium. End up.
Furthermore, when a thermal head is used as the transfer means, a large amount of thermal energy is input to the thermal head in order to heat soften or melt the thick primer panel, resulting in a significant decrease in the life of the thermal head. There was a problem that.
[0016]
The present invention has been made in view of the problems of the prior art, and uses a thermal transfer recording medium in which a primer layer is provided on a support so that thermal transfer is possible, and the primer layer is received by an intermediate transfer medium. In thermal transfer to the surface of the layer, a technology is provided that allows heat transfer to the intermediate transfer medium multiple times at an appropriate number of times of 2 or more depending on the state and properties of the transfer surface of the transfer object. Thus, an image forming apparatus capable of obtaining a strong final recorded image is provided.
[0017]
[Means for Solving the Problems]
The invention of claim 1
Use an intermediate transfer medium having at least a transferable image-receiving layer provided on a support and a thermal transfer recording medium having a colored layer using at least one of a pigment or a dye as a colorant provided on the support. Then, the surface of the image-receiving layer of the intermediate transfer medium and the surface of the colored layer of the thermal transfer recording medium face each other and are subjected to selective heating based on image information from at least one of the supports. Image recording means capable of recording a thermal transfer image on the image receiving layer by performing thermal transfer, and
Along with the image receiving layer, the surface of the image receiving layer on which the heat-sensitive transfer image of the intermediate transfer medium is recorded is superimposed on the surface to be transferred of the transfer object, and at least one of the intermediate transfer medium and the transfer object is heated. Image transfer means capable of transferring the heat-sensitive transfer image from an intermediate transfer medium onto the transfer target;
An image forming apparatus comprising:
(A) After recording a thermal transfer image by thermal transfer based on image information on the image receiving layer of the intermediate transfer medium, an area on the image receiving layer containing all or at least a part of the thermal transfer image of the intermediate transfer medium; Using the primer layer transfer sheet provided on the support so that the primer layer can be thermally transferred and the heating means for transferring the primer layer, the primer layer is overlaid on the primer layer transfer sheet approximately twice in the same area as the first time. A primer layer transfer means capable of thermal transfer;
(B) the image transfer means includes a transfer mechanism on which the thermal transfer image is recorded and the transferred primer layer can be transferred together with the image receiving layer from an intermediate transfer medium onto a transfer target;
An image forming apparatus including all of the above (a) and (b).
[0018]
The invention of claim 2
Use an intermediate transfer medium having at least a transferable image-receiving layer provided on a support and a thermal transfer recording medium having a colored layer using at least one of a pigment or a dye as a colorant provided on the support. Then, the surface of the image-receiving layer of the intermediate transfer medium and the surface of the colored layer of the thermal transfer recording medium face each other and are subjected to selective heating based on image information from at least one of the supports. Image recording means capable of recording a thermal transfer image on the image receiving layer by performing thermal transfer, and
Along with the image receiving layer, the surface of the image receiving layer on which the heat-sensitive transfer image of the intermediate transfer medium is recorded is superimposed on the surface to be transferred of the transfer object, and at least one of the intermediate transfer medium and the transfer object is heated. An image forming apparatus comprising image transfer means capable of transferring the heat-sensitive transfer image from an intermediate transfer medium onto the transfer target,
(C) a thermal transfer recording medium in which a primer layer is provided on a support separately from the colored layer in a surface-sequential manner, the primer layer being peelable from the support by heating, and the image receiving The image recording means can use a thermal transfer recording medium that exhibits adhesiveness by heating to both the layer and the transfer target, and can be transferred from the support to the image receiving layer.
(D) The image recording means records the thermal transfer image on the image receiving layer of the intermediate transfer medium by thermal transfer based on image information using the colored layer of the thermal transfer recording medium of (c). Using the thermal transfer recording device used for thermal transfer of the thermal transfer image, the primer layer on the thermal transfer recording medium is formed on the intermediate transfer medium on the image receiving layer containing all or at least part of the thermal transfer image. It is possible to perform thermal transfer over the same area as the first in two or more times,
(E) the image transfer means includes a transfer mechanism on which the heat-sensitive transfer image is recorded and the transferred primer layer can be transferred together with the image receiving layer from an intermediate transfer medium onto a transfer medium;
An image forming apparatus comprising all of the above (c) to (e).
[0019]
According to the first or second aspect of the present invention, the primer layer on the ink ribbon is thin and can be formed with high precision, so that dust such as burrs is not generated, and good foil cutting and transferability are basically provided. can get.
When the inventions of claim 1 and claim 2 are compared, claim 1 provides a thermal transfer recording medium (ink ribbon) with a colored layer and a thermal transfer recording medium with a transfer primer layer separately. However, handling and device control have the advantage of being relatively simple.
In addition, since the thermal transfer recording device used in the thermal transfer of the thermal transfer image can be used in the second aspect, the primer layer can be thermally transferred. The forming apparatus can be designed to be compact, and has an advantage that is advantageous in the case of aiming at space saving, weight saving, cost reduction, and the like.
[0020]
The invention according to claim 3 is characterized in that the number of times of thermal transfer of the primer layer onto the image receiving layer can be arbitrarily set and changed according to the transfer target. The image forming apparatus described in the above.
According to this, the number of thermal transfer of the primer layer onto the intermediate transfer medium changes the number of times the primer layer is transferred according to the surface condition and properties of the transfer surface of the transfer target. There is an advantage that even a body can cope with a good image adhesive strength.
[0021]
According to a fourth aspect of the present invention, the region where the primer layer is thermally transferred onto the image receiving layer can be arbitrarily set and changed based on data transmitted from a computer that controls the image forming apparatus. An image forming apparatus according to any one of claims 1 to 3.
According to this, there is an advantage that it is possible to select a place where the adhesive strength is desired to be increased and a place where the adhesive strength is desired to be decreased.
[0022]
According to a fifth aspect of the present invention, when a primer layer is thermally transferred onto the image receiving layer, all or at least a region on the image receiving layer to be transferred is based on data transmitted from a computer that controls the image forming apparatus. 5. The image forming apparatus according to claim 1, wherein a part of the primer layer can be arbitrarily thermally transferred in a dot pattern.
According to this, since the transfer adhesive strength of the transfer part can be controlled intentionally depending on the size of the halftone dot, for example, for a sign panel, the transfer layer is peeled off later, and an entry column is displayed. There is an advantage that can be.
[0023]
According to a sixth aspect of the present invention, in the means for thermally transferring a primer layer onto the image receiving layer, the heating means for transferring the primer layer is a heat roller. Device.
According to this, there is an advantage that the structure becomes simple and the device control becomes easy.
[0024]
According to a seventh aspect of the present invention, in any one of the first, third, fourth and fifth aspects, the primer layer transfer heating means is a thermal head as the means for thermally transferring the primer layer onto the image receiving layer. The image forming apparatus described.
[0025]
The invention according to claim 8 is characterized in that, for the means for thermally transferring the primer layer onto the image receiving layer, the thermal transfer recording device used for thermal transfer of the thermal transfer image is a thermal head. The image forming apparatus according to any one of 5.
[0026]
According to the invention of claim 7 or 8, there is an advantage that a very simple image forming apparatus can be constructed and the total issue time can be shortened.
[0027]
<Action>
According to the image forming apparatus of claim 2, the thermal transfer recording medium in which a colored layer using at least one of a pigment or a dye as a coloring material is provided on a support is used, and the thermal transfer is performed based on image information. An image forming apparatus in which a thermal transfer image is written by melting and transferring a recording medium, and then the image is transferred from the intermediate transfer medium to the transfer medium by heating and pressurizing the intermediate transfer medium to the transfer medium. In the thermal transfer recording medium (ink ribbon), a primer layer (primer panel as viewed from the ink ribbon) having thermal adhesion between the transfer target, the colored layer and the intermediate transfer medium is provided in advance. After the image formation on the intermediate transfer medium based on the image information is completed, the primer layer is melt-transferred onto the intermediate transfer medium at least twice. The thermal transfer recording device is the same as the thermal transfer recording device used at the time of formation, and then the image onto which the primer layer has been transferred is transferred from the intermediate transfer medium to the transfer target. Is exerted between the image layer, the image receiving adhesive layer on the surface of the intermediate transfer medium, and the transfer target, so that the adhesive strength between the transfer target and the image can be improved.
The image forming apparatus of claim 1 is different from the case of claim 2 in that a heating means different from the thermal transfer recording device that records the thermal transfer image is used to transfer the primer layer to the intermediate transfer medium. However, this makes the device control simple.
[0028]
Further, according to the image forming apparatus of the first or second aspect, the primer layer is transferred onto the intermediate transfer medium in a plurality of times. Therefore, when it is desired to increase the adhesive strength, the transfer amount is increased by increasing the number of times of transfer. I can do it. In addition, the density and roughness of the fibers of the fibrous material to be transferred such as paper are related to the adhesive force, and the coarser the paper fibers and the lower the density, the more primer layer to be transferred. It is essential that the image forming apparatus of the present invention can determine the number of times of transfer in accordance with the properties of the transfer target.
[0029]
In addition, since the primer panel provided on the ink ribbon may be a thin film, it can be produced on the same printing machine (gravure printing machine, etc.) as that used to produce the ink ribbon, and no die coater or micro gravure should be used. Therefore, it is possible to easily produce a primer panel in the ink ribbon in the same manner as each color of the ink ribbon.
[0030]
According to the image forming apparatus of the third aspect, the number of times of melt transfer onto the intermediate transfer medium of the primer layer changes the number of times of transfer of the primer layer in accordance with the properties of the object to be transferred. Good image adhesion strength is obtained. In addition, one apparatus can deal with various transferred objects such as a passport and a visa.
[0031]
According to the image forming apparatus of the fourth aspect, since the melt transfer range of the primer layer onto the intermediate transfer medium can be changed according to the data from the host computer, it is possible to select the portion where the adhesive strength is to be increased and the portion where the adhesive strength is to be decreased. It is possible to do it. For example, if you reduce the adhesive strength of a part of the image and give it a choice of adhesive strength, and try to peel it off for the purpose of fraud, for example, only that part will be easily bald and the whole will be beautiful The image layer can be made brittle, for example, it cannot be peeled off.
[0032]
According to the image forming apparatus of claim 5, with respect to the melt transfer onto the intermediate transfer medium of the primer layer, a part or all of the entire transfer area is melted and transferred in a halftone dot shape by data from the host computer. Depending on the size of the halftone dots, it is possible to intentionally control the transfer adhesive strength at the transfer location. Therefore, for example, for a sign panel or the like, the transfer layer can be peeled off later, and the entry field of the transfer object can be displayed.
Moreover, even if it is intentionally peeled off for the purpose of unauthorized use or the like, if the adhesive force is changed in various ways, it cannot be removed uniformly, and as a result, the unauthorized use can be prevented by the brittle effect.
[0033]
According to the image forming apparatus of claim 7 or 8, since the image forming means by melt transfer onto the intermediate transfer medium and the melt transfer means onto the intermediate transfer medium of the primer layer are performed by the same thermal head, for example, printing The primer panel can be transferred on the platen roller where the process is performed, so that a very simple image forming apparatus can be constructed and the total issuing time can be shortened.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described more specifically with reference to the drawings.
FIG. 1 is a schematic view showing an image forming apparatus according to the present invention, and a transfer target 1 (1 ′) is interposed through a base rubber sheet made of silicon rubber having a surface coated with a fluorine-based polymer compound (not shown). Is set on the tray 2 (2 '). Note that the positions of the transfer target 1 and the tray 2 indicated by solid lines are positions when the image on the intermediate transfer medium 6 is heated and pressed by the heat roller 40 on the transfer target 1. Further, the transfer object is transported on the rail 3 by wheels 4 (4 ′) and 5 (5 ′) by an actuator and a drive system (not shown).
[0035]
Reference numeral 6 denotes an intermediate transfer medium, which is supplied from the supply reel 23 and is guided by the guide rollers 13, 15, 16, 39 and the transport rollers 17, 18 (rotation direction h when traveling), 20, 19 (when traveling). It is conveyed to the take-up reel 24 in the rotation direction d), and is held by the clamp rollers 8 and 9 on the platen roller 10 coated with a fluorine-based polymer compound on the silicon-based elastomer layer at the time of image writing. Is written. Reference numeral 25 denotes a cleaning roller for removing dust on the platen roller.
[0036]
In this embodiment, the intermediate transfer medium 6 has a hologram image layer (including an electron beam drawing grating image) which is a diffraction grating image by hologram and electron beam drawing inside the intermediate transfer medium 6, in order to align the hologram image. The laser registration mark sensor 11 detects the origin position of the hologram image and performs alignment on the platen roller 10. Reference numeral 12 denotes a cleaning roller that removes dust on the image transfer side of the intermediate transfer medium 6, and removes dust on the image surface of the intermediate transfer medium together with a neutralizing brush (not shown).
[0037]
On the other hand, for image writing, in this embodiment, thermal transfer is performed by molten ink using an organic pigment or an inorganic pigment as a color material (actually, the ink is thermally softened). Gradation can be achieved by arbitrarily changing the size of the thermal transfer dots to be formed by image data (finally converted into a heating amount) applied to a heat-concentrating thermal head 38 that is approximately square in a micron square. Have sex.
[0038]
The ink ribbon 7 having the molten ink using the pigment is supplied from a supply reel 26, and is guided by a guide roller 36 and a transport roller 28 (rotation direction g when traveling) 29, and cleaning rollers 32 and 33 which also serve as guide rollers. The image is written onto the intermediate transfer medium 6 based on the image information by the heat-concentrated thermal head 34 which is conveyed to the take-up reel 27.
In addition, in order to distinguish each color in the ink ribbon 7, the sensor mark formed on the ink ribbon in advance is read by the sensors 30 and 31, and the distinction and alignment are performed. (See sensor marks 51 and 52 in FIG. 2)
[0039]
Then, the intermediate transfer medium on which the image is formed on the intermediate transfer medium is heated and pressed on the transfer body 1 by lowering the heat roller 40 in the direction b, and thereby the image of the intermediate transfer medium (thermal bonding that also serves as the image receiving layer). Layer), a hologram layer, a protective layer (not shown), etc., so-called image layers are transferred by heating and pressing. However, for safety, a flocked metal shutter 41.42 is provided between the heat roller 40 facing the transfer target 1 and the shutters 41 and 42 are moved in the direction C only when the heat roller descends in the direction b. , C ′ is opened, and the metal shutters 41 and 42 in which hair is planted so that a human hand or the like normally touches the heat roller 40 to avoid burns are closed.
[0040]
By the way, the heat roller 40 has a halogen lamp heater 41 inside, and is a hollow cylinder in which the inside of the section that absorbs the heat radiation from the Halon lamp heater is blackened. This is a reverse-roller heat roller provided with a conductive fluorine-based polymer compound. Then, by rotating the peripheral speed (the rotation direction is i) slightly faster than the transfer speed of the intermediate transfer medium or the transfer medium, a tension is intentionally generated outside the center of the intermediate transfer medium being heated, Generation of transfer media is prevented.
[0041]
The heat roller 40 detects the surface temperature with the temperature sensor 21 and keeps the surface temperature constant by a temperature controller or the like (not shown). Further, oil is used to keep the surface of the heat roller clean. An impregnated cleaning roller 22 is provided.
[0042]
FIG. 2 shows an ink ribbon used in this embodiment. In the drawing, the ink surface 50 is in front, and each color of black (Bk), cyan (C), magenta (M), and yellow (Y) is formed on a PET (polyethylene terephthalate) base film of about 4 to 5 μm. And a primer panel (P) is formed. In addition, the thickness of the ink layer used by the present Example is all 1 micrometer or less, and the primer layer is applied to about 2-3 micrometers.
[0043]
Incidentally, sensor marks 51 and 52 are provided in order to recognize the position of each ink color and primer on the image forming apparatus side. Among these, 51 is a sensor mark for recognizing the origin, and the mark is made long so that the sensor 30 and 31 in FIG. 1 can recognize the origin when both recognize the sensor mark.
Further, the region of the primer panel (P) is formed long to perform a plurality of transfers.
[0044]
Next, actual primer layer transfer and heat and pressure transfer of the intermediate transfer medium onto the transfer medium will be described with reference to FIGS.
FIG. 3 shows a thermal transfer image recorded on the intermediate transfer medium with each color ink.
A PET sheet having a thickness of about 25 μm is used as a support 60, and an image receiving adhesive layer 61 is formed thereon by a gravure printing method or a die coating method. However, the image receiving adhesive layer 61 actually includes a hologram layer, a peeling layer that improves peeling from the support, a security printing layer such as fluorescent printing, and the like. However, since only the image receiving adhesive layer corresponding to the outermost surface layer is necessary in the description of this embodiment, this layer is representative. On the image receiving adhesive layer 62, ink layers 62, 63, 64, and 65 are formed by thermally transferring each color according to area gradation. Each color needs to be overlapped for multi-color output. Thermal transfer is performed with overlapping parts.
[0045]
Next, FIG. 4 shows a case where the thermal transfer of the primer layer by the primer panel is performed only once by the thermal head, and the first primer layer 66 is formed on the intermediate transfer medium.
[0046]
Next, in FIG. 5, when the second primer layer is thermally transferred using the remaining part of the primer panel, the second primer layer 67 is placed on the first primer layer 66.
By the way, when an image (an image receiving adhesive layer, an ink layer, a primer layer, etc.) on the intermediate transfer medium is heated and pressed with a heat roller on the transfer body in two times with the primer coating, when the transfer body 68 is a paper medium If the primer covering thickness (thickness of reference numerals 66 and 67 in FIG. 5) is thicker than the thickness of the protruding portion of the fibers (uneven portions on the surface where the fibers protrude in a flaky shape) 69, the primer A strong thermal adhesive force can be expected when the layer penetrates the surface fiber portion.
[0047]
FIG. 6 shows the final recording medium that has been heated and pressurized (the image layer transferred onto the transfer target), and the primer layer formed by the two transfers is the surface of the transfer target surface. It can be seen that the unevenness is sufficiently filled.
[0048]
By the way, the inventors conducted an image forming experiment under the following conditions.

[0049]

[0050]
In Sample-2, it was confirmed that good adhesive strength was obtained by about 3 times primer transfer, and in Sample 2 by 2-3 times transfer. Even in adhesive property tests such as cellophane tape peeling test and Gakushin test. Good results were obtained.
In addition to paper fibers, it has also been found that it is better to change the number of times of primer transfer depending on the performance of preprinting performed on the transfer medium in advance.
[0051]
【The invention's effect】
As described above, according to the present invention, when a thermal transfer recording medium in which a primer layer is provided on a support so as to be capable of thermal transfer is used and the primer layer is thermally transferred onto the surface of the image receiving layer of the intermediate transfer medium, Depending on the state and nature of the transfer surface of the body, a technique is provided that can be heat-transferred onto the intermediate transfer medium multiple times at an appropriate number of times of 2 or more, thereby obtaining a strong final recorded image An image forming apparatus capable of being provided has been provided.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing an image forming apparatus according to the present invention.
FIG. 2 is an explanatory view schematically showing a thermal transfer recording medium (ink ribbon) used in one embodiment according to the present invention.
FIG. 3 is an explanatory view schematically showing a state where a thermal transfer image is recorded with ink of each color on an intermediate transfer medium used in one embodiment according to the present invention.
FIG. 4 is an explanatory diagram schematically showing that the thermal transfer of the primer layer by the primer panel is performed only once by the thermal head.
FIG. 5 is an explanatory view schematically showing a second thermal transfer of the primer layer using the remaining part of the primer panel.
FIG. 6 is an explanatory diagram schematically showing a final recording medium that has been heated and pressed (in which each layer of an image is transferred onto a transfer medium).
[Explanation of symbols]
1, 1 '... transferred object
2, 2 '... Tray
3 ... Rail
4, 4 ', 5, 5' ... wheel
6 ... Intermediate transfer medium
10: Platen roller
13, 15, 16, 39 ... guide rollers
17, 18 ・ ・ ・ Conveying roller
40 ・ ・ ・ Heat roller

Claims (8)

Use an intermediate transfer medium having at least a transferable image-receiving layer provided on a support and a thermal transfer recording medium having a colored layer using at least one of a pigment or a dye as a colorant provided on the support. Then, the surface of the image-receiving layer of the intermediate transfer medium and the surface of the colored layer of the thermal transfer recording medium face each other and are subjected to selective heating based on image information from at least one of the supports. Image recording means capable of recording a thermal transfer image on the image receiving layer by performing thermal transfer, and
Along with the image receiving layer, the surface of the image receiving layer on which the heat-sensitive transfer image of the intermediate transfer medium is recorded is superimposed on the surface to be transferred of the transfer object, and at least one of the intermediate transfer medium and the transfer object is heated. Image transfer means capable of transferring the heat-sensitive transfer image from an intermediate transfer medium onto the transfer target;
An image forming apparatus comprising:
(A) After recording a thermal transfer image by thermal transfer based on image information on the image receiving layer of the intermediate transfer medium, an area on the image receiving layer containing all or at least a part of the thermal transfer image of the intermediate transfer medium; Using the primer layer transfer sheet provided on the support so that the primer layer can be thermally transferred and the heating means for transferring the primer layer, the primer layer is overlaid on the primer layer transfer sheet approximately twice in the same area as the first time. A primer layer transfer means capable of thermal transfer;
(B) the image transfer means includes a transfer mechanism on which the thermal transfer image is recorded and the transferred primer layer can be transferred together with the image receiving layer from an intermediate transfer medium onto a transfer target;
An image forming apparatus comprising all of the above (a) and (b). Use an intermediate transfer medium having at least a transferable image-receiving layer provided on a support and a thermal transfer recording medium having a colored layer using at least one of a pigment or a dye as a colorant provided on the support. Then, the surface of the image-receiving layer of the intermediate transfer medium and the surface of the colored layer of the thermal transfer recording medium face each other and are subjected to selective heating based on image information from at least one of the supports. Image recording means capable of recording a thermal transfer image on the image receiving layer by performing thermal transfer, and
Along with the image receiving layer, the surface of the image receiving layer on which the heat-sensitive transfer image of the intermediate transfer medium is recorded is superimposed on the surface to be transferred of the transfer object, and at least one of the intermediate transfer medium and the transfer object is heated. An image forming apparatus comprising image transfer means capable of transferring the heat-sensitive transfer image from an intermediate transfer medium onto the transfer target,
(C) a thermal transfer recording medium in which a primer layer is provided on a support separately from the colored layer in a surface-sequential manner, the primer layer being peelable from the support by heating, and the image receiving The image recording means can use a thermal transfer recording medium that exhibits adhesiveness by heating to both the layer and the transfer target, and can be transferred from the support to the image receiving layer.
(D) The image recording means records the thermal transfer image on the image receiving layer of the intermediate transfer medium by thermal transfer based on image information using the colored layer of the thermal transfer recording medium of (c). Using the thermal transfer recording device used for thermal transfer of the thermal transfer image, the primer layer on the thermal transfer recording medium is formed on the intermediate transfer medium on the image receiving layer containing all or at least part of the thermal transfer image. It is possible to perform thermal transfer over the same area as the first in two or more times,
(E) the image transfer means includes a transfer mechanism on which the heat-sensitive transfer image is recorded and the transferred primer layer can be transferred together with the image receiving layer from an intermediate transfer medium onto a transfer medium;
An image forming apparatus comprising all of the above (c) to (e). The image forming apparatus according to claim 1, wherein the number of times of thermal transfer of the primer layer onto the image receiving layer can be arbitrarily set and changed according to the transfer target. 4. An area for thermal transfer of a primer layer on the image receiving layer can be arbitrarily set and changed based on data transmitted from a computer that controls the image forming apparatus. The image forming apparatus according to any one of the above. When the primer layer is thermally transferred onto the image receiving layer, the primer layer is formed on all or at least a part of the area on the image receiving layer to be transferred based on data transmitted from a computer that controls the image forming apparatus. The image forming apparatus according to claim 1, wherein thermal transfer can be arbitrarily performed in a halftone dot shape. 4. The image forming apparatus according to claim 1, wherein, for the means for thermally transferring the primer layer onto the image receiving layer, the heating means for transferring the primer layer is a heat roller. 6. The image forming apparatus according to claim 1, wherein, for the means for thermally transferring the primer layer onto the image receiving layer, the heating means for transferring the primer layer is a thermal head. 6. The thermal transfer recording device used for thermal transfer of the thermal transfer image as a means for performing thermal transfer of a primer layer on the image receiving layer is a thermal head. Image forming apparatus.

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