JPH0714645B2 - Transfer recording medium and image forming method - Google Patents

Description

The present invention relates to a multicolor or halftone image forming method applicable to printers, copying machines, facsimiles and the like.

[Prior Art] In recent years, along with the rapid development of the information industry, various information processing systems have been developed, and recording methods and apparatuses suitable for the respective information processing systems have been developed. One of such recording methods is a heat-sensitive recording method. This method is widely used in recent years because the apparatus used is lightweight and compact, has no noise, and has excellent operability and maintainability.

Among these heat-sensitive recording methods, the heat-sensitive transfer recording method has recently attracted particular attention. This method of recording is generally
A heat-sensitive transfer medium obtained by applying a heat-transferable ink having a colorant dispersed in a heat-meltable binder on a sheet-shaped support is used, and the heat-sensitive transfer medium is used as a transfer medium. The transferred recording image is transferred according to the heat supply pattern by superimposing on the transfer medium so as to be in contact with each other, and by supplying heat from the support side of the thermal transfer medium with a thermal head or the like to transfer the melted ink layer to the transfer medium. It is formed on the transfer medium. According to this method, plain paper can be used as the transfer medium.

However, such a conventional thermal transfer recording method is not without drawbacks. In the conventional thermal transfer recording method, the transfer recording performance, that is, the image quality is greatly affected by the surface smoothness of the transfer medium, and good printing can be performed on the transfer medium having high smoothness, but the smoothness is low. This means that the print quality is remarkably deteriorated in the transferred medium. Moreover, even the most common transfer medium, paper with high smoothness is rather special, and ordinary paper has various degrees of unevenness due to the entanglement of fibers. Therefore, in the case of paper with large surface irregularities, the heat-melted ink cannot penetrate into the fibers of the paper at the time of printing and adheres only to the convex parts of the surface or its vicinity, resulting in sharp edges of the printed image. Or a part of the image is missing and the print quality is degraded.

Further, in the conventional thermal transfer recording method, the transfer of the ink layer to the transfer medium is performed only by the heat from the thermal head, but generally the amount of heat that can be supplied from the thermal head is limited and limited. In order to convert and supply a large number of recording signals as heat pulses in a time period, a time lag of cooling to a predetermined temperature between heat pulses of the thermal head during recording,
Further, it is theoretically difficult to increase the amount of heat supplied from the thermal head in order to prevent a thermal stroke between the heat-generating segments forming the thermal head surface. Therefore, high-speed recording has been difficult with the conventional thermal recording method.

In addition, since heat conduction has a slower response response than electricity or light, it is generally difficult to control the heat pulse until halftone can be reproduced when recording with a thermal head. Since the heat-sensitive transfer ink layer of No. 1 does not have transfer characteristics capable of expressing gradation, it was not possible to form a halftone recorded image.

Further, when trying to obtain a multicolor image by the conventional thermal recording method, it is necessary to make a complicated movement such as a stop on one of the medium to be transferred and the thermal transfer medium, and the entire apparatus becomes large and complicated. There was a drawback.

The present invention has been made in view of the above problems, and an object of the present invention is to form a high-quality transfer image on plain paper, which has low plane smoothness and is most commonly used, and is capable of high-speed recording. Provided are a multicolor image forming method and a multicolor transfer recording medium used for the same, which enables halftone recording and does not require complicated movement of a thermal transfer medium or a transfer target medium to easily obtain a multicolor image. To do.

It should be noted that one raster described in the specification of the present invention is one line in the main scanning direction perpendicular to the transfer proceeding direction of the transfer recording apparatus.

[Means for Solving the Problems] The above object of the present invention has a transfer recording layer composed of two or more kinds of image forming elements exhibiting different color tones or optical densities on a substrate, and the image forming element is Has a sensitive component whose physical properties change the transfer characteristics when heat and light energy are applied, and the conditions of heat and light energy that change the physical properties are the color tone or optical density exhibited by the image forming element. Common within each combination of one or more combinations in which two or more kinds of image-forming elements exhibiting different conditions and different color tones or optical densities are selected and combined as desired. And a transfer recording medium having the following conditions, and light and heat energy are applied to the transfer recording medium under conditions corresponding to recorded image information and different conditions depending on the color tone or optical density of the image forming element. A multicolor or halftone image forming method including the steps of sequentially forming transfer images one raster at a time, and transferring the transfer images to a transfer medium, wherein the transfer image is formed within one raster. ,
In the case where the step of changing the transfer characteristics of at least one set of a combination of two or more kinds of image forming elements having a common energy applying condition for changing the physical properties is included, at least these image forming elements are included. This is achieved by an image forming method in which heat and light energy are applied to a portion corresponding to one raster of the transfer recording layer in accordance with recording information under an energy applying condition common to the above.

That is, the transfer recording medium of the present invention, as shown in FIGS. 2a to 2f, is formed by laminating an image forming element body 1a containing a coloring material on a base material 1b. When energy is applied to this image-forming element, the physical properties that govern the transfer characteristics change, but the physical properties can be changed by applying heat at the same time. As conditions for changing the physical properties by applying light and heat, there are two or more clearly distinguishable conditions, and the physical properties of the image forming element change similarly under the respective applying conditions. One of the conditions of the change in the physical properties is different for each color tone or optical density exhibited after the transfer of each image forming element, and is a condition specific to the image forming element exhibiting the same color tone or optical density, and the other condition is That is, there are some conditions that are common to the physical property changing conditions other than the conditions specific to the color tone or the optical density of the image forming element exhibiting another expression tone or the optical density.

First, in order to understand the formation of an image using the transfer recording medium of the present invention, as shown in FIGS. 2a to 2f, the transfer recording layer 1a is provided on the base film 1b, and light and thermal energy are provided. An example using the transfer recording medium 1 on which a transfer image is formed will be described with reference to FIGS. 1a to 1d. Fig. 1a-Fig.
The time axis (horizontal axis) of each graph in Fig. 1d corresponds to each other. Further, the transfer recording layer contains, as a sensitive component, a polymerizing component containing a reaction initiator and a crosslinking agent described later.
FIG. 1a shows how the surface temperature of the heating element rises and the temperature drops thereafter when the heating means such as a thermal head is driven to generate heat for a period of time 0 to t ₃ . The transfer recording layer on the transfer recording medium pressed against the heating element shows a temperature change as shown in FIG. 1b with a temperature change of the heating element. That is, the temperature rises with a time delay of t ₁ ,
Similarly, after t ₃ , the maximum temperature is reached at time t ₄ , and then the temperature decreases. This transfer recording layer has a glass transition point Tg 2 _O and is rapidly softened and its viscosity is reduced in a temperature range above Tg 2 _O. This situation is shown by the curve A in FIG. 1c. Tg _O at time t ₂
Drop until time t ₄ when reaching the maximum temperature the viscosity continues after reaching increased again viscosity decreasing temperature and accompanied viscosity until time t ₆ for lowering the Tg _O increases rapidly. In this case, the transfer recording layer has basically no change in physical properties before heating,
In the next transfer step, the same phenomenon of change in viscosity as described above is exhibited only by heating to a temperature of Tg 2 _{O 3} or higher. Therefore, if the recording medium is pressed into contact with the medium and heated for the transfer, such as Tg 2 _{O 3} or more, the transfer recording layer is transferred by a mechanism similar to the transfer mechanism of the conventional thermal transfer recording. However, in the case of the present invention, as shown in FIG. 1d, when light is irradiated simultaneously with heating of the transfer recording layer from time t _{2, the} reaction initiator contained in the transfer recording layer is irradiated by light. When activated and the temperature rises high enough to increase the reaction rate, the reaction initiator acts to produce an activated crosslinker, which dramatically increases the probability of crosslinking the crosslinkable prepolymer. And the curing of the transfer recording layer progresses.

When the heating and the light irradiation are simultaneously performed in this way, the transfer recording layer behaves as shown by the curve B in FIG. 1c. The glass transition temperature rises with the crosslinking reaction proceeds, the crosslinking changes the Tg 'from Tg _O at time t ₅ is terminated. This is shown in Figure 1d. Therefore, when heated in the next transfer step, Tg '
There is a difference in the physical properties (temperature dependence of viscosity) between the part that has changed and the part that has not changed. So, for example, Tg _O <Tr <T
When heated to a temperature Tr satisfying g ′, a portion where the viscosity is reduced and a portion where the viscosity is not generated are generated, and only the portion where the viscosity is reduced is transferred onto the transfer medium. Depending on the temperature stability accuracy of the transfer process, TG'-Tg _O at this time is preferably about 20 ° C. or higher. In this way, the transfer image can be formed by controlling heating or non-heating according to the image signal and irradiating light at the same time. If the glass transition point changes, the softening temperature and the melting temperature also fluctuate with the same tendency. Therefore, the softening temperature and the melting temperature can be controlled by using the fluctuation range of the glass transition point as a guide.

With reference to the principle of the image forming method described above, the image forming method of the present invention will be described below. First, the image forming method when the image in one raster is not recorded, or is not a single color or a single gradation. This will be described with reference to FIGS. 2a to 2f.

The transfer recording medium 1 includes a transfer recording layer 1a on a base film 1b.
Is provided. The transfer recording layer 1a is a layer in which minute image forming elements 1aa are mixed, and each image forming element 1aa has a different color tone. For example, FIGS. 2a to 2f showing the relationship between the transfer recording medium of the present invention and the thermal head.
In the embodiment as shown in the drawing, each image forming element 1aa contains a color material of any one of cyan (C), magenta (M), yellow (Y) and black (K). The color material contained in each image forming element 1aa is not limited to cyan, magenta, yellow and black, and any color material may be used depending on the application. Each image forming element body 1aa contains, in addition to the coloring material, a sensitive component that changes physical properties that govern transfer characteristics when light and heat energies are applied.

The sensitive component of each image forming element 1aa is configured to include one having different wavelength dependence depending on the contained coloring material and one having common wavelength dependence regardless of the coloring material. That is, an image forming element body containing a yellow coloring material
In 1aa, when heat and light of wavelength λy or common wavelength λn are applied, crosslinking rapidly progresses and cures. Similarly, the image forming element body 1aa containing the magenta coloring material has heat and wavelength λm.
Alternatively, the light of the common wavelength λn, the image forming element 1aa containing the cyan coloring material is heat and the wavelength λc or the light of the common wavelength λn,
The image forming element body 1aa containing the black coloring material undergoes crosslinking and cures when heat and light of the wavelength λk or the common wavelength λn are applied.

Using the transfer recording medium as described above, for example, an image in a portion where both light and heat in one raster are simultaneously applied to form a non-recorded image, a single color image, or a single gradation image In the formation, the transfer recording medium 1 is superposed on the thermal head 20, and light is irradiated so as to cover the entire heating portion of the thermal head 20. The irradiating light sequentially irradiates with a wavelength with which the image forming element 1aa reacts. For example, when the image forming element body 1aa is colored in any of cyan, magenta, yellow and black, light having wavelengths λc, λm, λy and λk are sequentially irradiated.

That is, first, light having a wavelength λy is irradiated from the transfer recording layer 1a side of the multicolor transfer recording medium 1 and, for example, the heating resistors 20b, 20c, 20d and 20f of the thermal head 20 are caused to generate heat. Then, the image forming element body 1a containing the yellow coloring material
Of a, the image forming element body 1aa (hatched portion in FIG. 2a; hereinafter, the cured image forming element body is hatched) to which both heat and light of wavelength λy are applied is cured. .

Next, as shown in FIG. 2b, the transfer recording layer 1a is irradiated with light having a wavelength of λm and the heating resistors 20a, 20e and 20f are caused to generate heat, whereby an image forming element containing a magenta coloring material is formed.
Of the 1aa, the image forming element body 1aa to which heat and light of wavelength λm are applied is cured. Further, as shown in FIGS. 2c and 2d, when the light having the wavelength λc and the light having the wavelength λk are respectively irradiated and the desired heating resistor is heated, the image forming element body to which the light and the heat are applied is formed. 1aa is cured, and finally a transfer image is formed on the transfer recording layer 1 by the image-forming element body 1aa which is not cured. This transfer image is transferred to the transfer medium 10 as shown in FIG. 2f in the next transfer step.

In the transfer step, the transfer recording medium on which the transfer image is formed is brought into contact with the transfer target medium and heated from the transfer recording medium side or the transfer target medium side, and the transfer image is selectively transferred to the transfer target medium to form an image. To form. Therefore, the heating temperature at this time is selected so that only the transferred image is selectively transferred with respect to the physical properties that govern the transfer characteristics. Also, in order to perform the transfer efficiently,
It is also effective to apply pressure at the same time. Pressurization is particularly effective when a transfer medium having a low surface smoothness is used. When the physical property that governs the transfer characteristic is the viscosity at room temperature, the transfer can be performed only by pressure as the energy applied in the transfer step. Heating in the transfer step is suitable for obtaining a stable multicolor image having excellent storage stability.

Further, when no recording is made in the same raster, only the light of the wavelength λn common to all the image forming elements is irradiated and the whole is heated by the thermal head.

When the image formed by the irradiation of heat and light in the same raster is a single color, for example, a single color of yellow, the image forming element showing cyan, magenta, and black is further cured in the apparatus of the above example. Assuming that there is a light source that emits light of a wavelength, only that light is irradiated and the whole is heated by the thermal head.

As described above, in the embodiment described with reference to FIGS. 2a to 2f, the method of irradiating the entire area of the thermal head 20 with light and selectively heating the heating resistors of the thermal head 20 to form an image has been described. , Evenly heat a portion of the transfer recording medium (2a
In the case of the thermal head 20 shown in the figure, a multicolor image can be similarly formed by selectively performing light irradiation when all the heating resistors are heated. That is, light energy of a wavelength that is modulated according to a recording signal and that is selected according to the color tone of the image forming element whose physical properties dominate transfer characteristics is desired is applied together with heat energy.

Explaining with the example shown in FIG. 2a, the heating resistors 20b, 20d,
Instead of heating 20e and 20f, the thermal head 20
Heats the whole uniformly, and irradiates the light having the wavelength λy to the positions corresponding to the heating resistors 20b, 20d, 20e and 20f. Also when irradiating with light of wavelength λm, the entire thermal head 20 is caused to generate heat, and light is irradiated to the positions corresponding to the heating resistors 20a, 20e and 20f. The same applies when irradiating light of wavelength λc and wavelength λk.

According to this image forming method, it is basically possible to express eight colors of a plurality of colors (for example, Y, M, C, R, G, B, BK, W) for each recording pixel. Therefore, by combining these, so-called full-color expression is also possible. That is, as shown in FIG. 3, a pseudo halftone expression can be made by arranging the number of recording pixels arranged in a matrix composed of a plurality of pixels. Kana full-color expression is possible.

Many such methods have been proposed, and some of them have been put into practical use. However, in the image forming method as well, due to the characteristics thereof, conventional digital image forming means (for example, an inkjet method, a laser electrophotographic method, an electrostatic recording method) is used. , A thermal recording method, etc.) is basically applicable. Further, as described above, it is possible to express a plurality of stages of halftones with one recording pixel and to express multiple gradations by distributing these pixels in a matrix, and a high resolution and high quality image can be obtained. .

In the above description, as shown in FIG. 2f, each element is discretely scattered on the transfer medium (recording paper etc.),
This is a form for convenience of explanation only, and the transferred element actually spreads two-dimensionally on the surface of the transfer medium, and as a result, corresponds to each heating element of the thermal head in the example of FIG. Then, each pixel is formed correctly.

Further, in the above-described transfer image forming method, an example in which the image forming element has different spectral sensitivity for each color has been shown, but this characteristic is not always necessary in the present invention. For example, if two kinds of materials having different temperature characteristics and reacting to heat and light are used, the spectral characteristics are the same and can be distinguished by the applied thermal energy.

As the transfer recording medium used in the image forming method, any transfer recording medium can be used as long as it can form a transfer image by changing the physical properties by a plurality of types of energy. For example, a transfer recording medium containing a polymerizing component and a coloring component in the transfer recording layer may be mentioned as a material whose physical properties such as the melting temperature, softening point, glass transition temperature and viscosity are changed. By polymerizing the polymerizing component, the melting temperature and the like of the transfer recording layer at that portion becomes high, and the portion not polymerized forms a transfer image. The image-forming element that forms the transfer recording layer contains a sensitive component and a coloring material, but the sensitive component is one in which the reaction rate of changes in physical properties changes rapidly when irradiated with light and heat energy. To use.

This polymerizing component is a component that causes a polymerization reaction or a crosslinking reaction, and typical examples thereof include the following monomers or polymers (a) to (c).

(A) Crosslinkable prepolymer, (b) Polymerizable prepolymer and crosslinker, (c) Polymerizable monomer or oligomer, and crosslinkable premolymer include, for example, polyvinyl cinnamate, p-methoxycinnamic acid-succinic acid half. Ester, polyvinyl styrylpyridinium, polymethyl vinyl ketone,
Examples thereof include copolymers of methyl vinyl ketone and methyl isopropeno ketone with ethylene and styrene, and polysulfone.

Examples of the polymerizable prepolymer include epoxy resin, unsaturated polyester resin, polyurethane resin, polyvinyl alcohol resin, polyamide resin, polyacrylic acid resin, polymaleic acid resin, and silicone resin.

Examples of the cross-linking agent include ethylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate and N, N'-methylenebisacrylamide.

Examples of the polymerizable monomer include methyl acrylate,
Methyl methacrylate, cyclohexyl acrylate,
Benzyl acrylate, acrylamide, methacrylamide, N-methylol acrylamide, N-diacetone acrylamide, styrene, acrylonitrile, vinyl acetate, ethylene glycol diacrylate, butylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6- Hexane diol dimethacrylate etc. are mentioned.

Examples of the polymerizable oligomer include diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol acrylate, polyethylene glycol dimethacrylate, polypropylene glycol diacrylate, and the like.

When a polymerizable monomer or oligomer is used, a polymer such as cellulose acetate succinate or methyl ketacrylate-hydroxyethyl methacrylate copolymer may be contained in order to improve the layer forming property.

If necessary, a reaction initiator is added to cause a reaction of the polymerizing component. Examples of the initiator that acts by light energy as a reaction initiator include benzophenone, benzyl, benzoin ethyl ether, 4-N, N-
Carbonyl compounds such as dimethylamino-4'-methoxy-benzophenone; organic sulfur compounds such as dibutyl sulfide, benzyl disfilled, decyl phenyl sulfide; peroxides such as di-tert-butyl peroxide, benzoyl peroxide; carbon tetrachloride , Halogen compounds such as silver bromide and 2-naphthalenesulfonyl chloride; nitrogen compounds such as azobisisobutyronitrile and benzenediazonium chloride; and the like.

Further, as a substance which receives thermal energy and acts as a reaction initiator, methyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl cumyl peroxide, peroxyacetic acid, peroxybenzoic acid, acetyl peroxide, Examples thereof include propionyl peroxide, isobutyryl peroxide, acetone peroxide, methyl ethyl ketone peroxide, diazoamine benzene, dimethyl-2,2'-azoisobutyrate, diphenyl sulfide and benzoyl disulfide.

In particular, the structure of the transfer recording layer in the case of forming a transfer image by receiving both light and thermal energy, the reaction rate of reaction rate by the reaction between the above-mentioned reaction initiator which acts upon receiving light energy and the polymerizing component. The types of the reaction initiator and the polymerizing component may be selected so that the combination is highly temperature-dependent.

For example, a combination of a polymerizable prepolymer having a functional group such as a copolymer of methacrylic acid ester or acrylic acid ester, a photosensitive cross-linking agent such as tetraethylene glycol diacrylate, and a reaction initiator such as benzophenone or Michler's ketone may be used. Can be mentioned.

The coloring component is a component contained to form an optically recognizable image, and various pigments and dyes are appropriately used. Thus, examples of pigments and dyes include inorganic pigments such as carbon black, yellow lead, molybdenum red, red iron oxide, Hansa Yellow, Benzidine Yellow, Brilliant Carmine 6B, Lake Red C, Permanent Red F5R, Phthalocyanine Blue, Victoria Blue Lake. , Organic pigments such as Fast Sky Blue, and coloring agents such as leuco dyes and phthalocyanine dyes.

In the transfer recording medium used for forming a multicolor image in the image forming method of the present invention, the image forming element constituting the transfer recording layer needs to have wavelength dependence depending on the type of coloring material, and in the case of reproducing full color. It is in. As I said before,
When the transfer recording layer is composed of four types of image forming elements, light having different wavelengths for each colored color, that is, a reaction speed that can be rapidly changed at four different wavelengths The combination of components constitutes the distribution layer of the image forming element. As a combination of such sensitive components, for example, benzoin as a photopolymerization initiator, carbonyl compounds such as polynuclear quinones are 360 to 420 nm, and halogen compounds such as silver halide, silver bromide and mercury tetrachloride are 300 to 400 nm. Expose to light.
In addition, sensitizers such as tert-butyl peroxypivalate and triethanolamine are exposed up to 700 nm.

Among the polymers with photosensitive groups, for example, cinnamoyl is 30
Benzalacetophenone at 0 nm is sensitive to 250-400 nm and o-quinonediazide is sensitive to 320-470 nm.

The transfer recording medium for forming a multicolor image as described above can be manufactured, for example, as follows.

The components such as a polymerizable prepolymer having a functional group, a photosensitive cross-linking agent, a reaction initiator, a sensitizer, a stabilizer, and a coloring material are kneaded by heating for each color. Furthermore, after thoroughly mixing the image forming elements of each color with a binder such as polyester resin in a solvent such as ethyl methyl ketone or ethylene glycol acetate, solvent coating is performed on a film such as polyimide and further dried at 800 ° C for 3 minutes to remove the solvent. A desired recording medium can be obtained by removing the.

The above example shows the case where the melting temperature and the like of the portion to which a plurality of types of energy are applied become hard, but when a component that softens by receiving a plurality of types of energy or has a low melting temperature is used as the transfer recording medium. In the area where the energy is received, the transfer increase is formed. Such components include polymethyl vinyl ketone, polyvinyl phenyl ketone, copolymers of methyl vinyl ketone or methyl isopropenyl ketone with ethylene, styrene, etc., copolymers of ethylene with carbon oxide, vinyl chloride, acrylate, etc. Examples thereof include copolymers with carbon monoxide, polyamide-imide, polyamide, polysulfone, and the like.

Next, in the image forming method of the present invention, the step of image formation when the image of the portion formed by applying both light and heat in the same raster at the same time is non-recorded or single color or single gradation The effect of shortening the image forming time will be described with reference to FIGS. 6 to 7 when all the images in the same raster are unrecorded or have a single color or a single gradation.

FIG. 6 shows yellow, magenta, cyan, and
9 is a schematic drive timing chart when an image including a portion in which all images in one raster are unrecorded is formed in an image forming method using a transfer recording medium using four colors of black. Further, FIG. 7 schematically shows a recording sample obtained by forming the above image. In the shaded area of 7a, multicolor or halftone recording is made. Seventh Figure 7b has a region that does not print at all (margin), this time corresponds to Figure 6 T _3. 7a
In the shaded area, the time corresponding to T ₂ is required for one raster because the energy corresponding to each of the image forming elements containing the color material is sequentially applied. In section 7b, 1
It takes T ₁ time per raster, and at this time, the fluorescent lamp that makes all of the image forming elements containing each color material effective.
3a is illuminated.

Since T ₂ is the time for which four fluorescent lamps are sequentially irradiated, it is 4 times or more than T ₁ , and it can be said that the efficiency of the image forming method of the present invention is 4 times or more in this respect. T21 forms a transfer image of a yellow component, t22 a magenta component, t23 a cyan component, and t24 a black component in one raster. Section 7c is present the image again, an image of a multi-color or intermediate color, which corresponds to the time of Figure 6 T _5.

As another embodiment, a method of irradiating light that reacts yellow and magenta and light that reacts cyan and black at the same time, that is, one at a time may be considered.

In the above description, the speed of the margin was increased by trying to react all the image forming elements in common, but for example, in the case of multicolor recording, if only the image forming element corresponding to black is not reacted, High speed recording is possible when recording black single color as compared to when recording multiple colors. Also, in the case of halftone recording, if only one density color is not reacted as in the above case, the speed can be increased in the case of binary recording. There are many possible combinations for this speedup.

Further, in the above description, the non-recording time is described separately for the single recording time, but it is for the purpose of facilitating the description, and it goes without saying that these are actually mixed.

Next, in the case of halftone recording, this is also the same as the above, that is, if the optical density of the image of the portion formed by applying both light and heat at the same time in the same raster is the same, recording of multiple gradations is possible. Recording speed T ₁ / can be realized with raster.

In the above description, the non-recording time is described separately from the single color recording time, but it is for the purpose of facilitating the description, and it goes without saying that these are actually mixed.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples and Examples.

Example 1 The respective components shown in Tables 1 to 4 were melt-mixed in a dark place, and then the solvent was dried to obtain four kinds of powdery image forming elements. The sensitizers in these image-forming elements are the same in the same order for each of Tables 1 to 4 as about 370 to 420 μm, about 420 to 500 μm, about 500 to 550 μm.
m, absorbs light in the band of about 550-600 μm, starts reaction,
The one-way photocrosslinkable polymer absorbs light in the band of about 320 to 370 μm, initiates the reaction, and raises the glass transition point of the image forming element. The colorants in the image forming element are cyan, when forming an image on the recording medium, in the same order, respectively.
It exhibits yellow, black, and magenta colors. It should be noted that a mixture of these four types of image-forming elements was uniformly dispersed and mixed in polymethylmethacrylate, and then the thickness after drying was applied to a base material (referred to as base material 1b) made of polyimide and having a thickness of 6 μmn. To form a layer (this is referred to as a transfer recording layer 1a) to obtain a transfer recording medium 1.

In the transfer recording device shown in FIG. 4, 3a is a 60w type plaque light (manufactured by Toshiba), and 3b uses Eu ^++- activated (SrMg) ₂ P ₂ O ₇ as a phosphor. 40w fluorescent lamp for diazo copier, 3c is Eu0.8 ⁺ activated Ba0.88Mg1.1A
40W high color rendering blue lamp using 19.7O16.7 BaMg-Aluminate phosphor. 3d and 3e are phosphors with Tb ³⁺ activated (L
a, Ce, a high color rendering green fluorescent lamp 60W type using _{Tb) 2 O 3 · 0.2SiO 2} · 0.9P 2 O 5, the short wavelength transmission filter f ₁ for cutting light of more than 550nm in 3d , 3e was equipped with a sharp cut filter f ₂ for cutting light of 550 nm or less between the irradiation surface and the fluorescent lamp.

FIG. 5 is a graph showing the relative spectral power of the above fluorescent lamp (with a sharp cut filter arranged).
In the figure, λ ₁ , λ ₂ , λ ₃ , λ ₄ , and λ ₅ are 3a and 3 in FIG.
It supports b, 3c, 3d, 3e. Further, 3b, 3c, 3d and 3e are fluorescent lamps that start the reaction of the sensitizer in the image forming element that exhibits cyan, yellow, black and magenta when an image is formed.

In the above-mentioned transfer recording apparatus, the supply roll 2 in which the transfer recording medium 1 was wound in a roll shape was arranged so that the substrate 1b was in contact with the thermal head 4 as shown in FIG. During the image forming process, the transfer recording medium 1 was extruded onto the thermal head 4 by the tension between the supply roll 2 and the heat roller 8.

If the images in one raster were neither single color nor all uncolored, then the image formation in one raster was done as follows. That is, first, the heating element corresponding to yellow of the image signal is not energized, and 2 msec is applied to the portion corresponding to the non-recording of the image signal.
At the same time, the fluorescent lamp 3c for diazo copying machine was uniformly irradiated for 4 mSec. After 1 msec after irradiation, the heating element corresponding to magenta of the image signal is not energized, and 2 mSec is energized to the part corresponding to no recording of the image signal, and at the same time, the high color rendering green fluorescent lamp 3
Irradiation with d was performed for 4 mSec uniformly. Similarly, in the case of cyan, the black light 3e is irradiated, and in the case of black, the health ray lamp 3f is irradiated to complete the latent image formation of all four colors at 20 mSec.

When all the images in one raster were unrecorded, all the heating elements were energized and the fluorescent lamp of 3a was uniformly irradiated with 4 mSec.

Recording time per raster is 20mSec, 4mS as above
Since it is different from ec and 4mSec, variable speed driving was performed by micro step driving with a pulse motor. At this time, the pulse motor was made to advance by the specified value when 64 pulses were applied.
The transfer recording medium 1 was conveyed by a stepping motor (not shown) and a heat roll 8 in synchronization with this speed change. After forming the transfer image in this way, the recording paper 10 which is a plain paper having a surface smoothness of 10 to 30 seconds is superposed on the transfer image surface, and is conveyed while being sandwiched between the heat roll 8 and the pinch roll 9 to perform the transfer. The heat roll 8 has a 300 W heater 7 inside and the surface is 2 mm.
Aluminum roll coated with thick silicon rubber makes the surface 90 ~
The heater 7 was controlled to keep it at 100 ° C. The pinch roll 9 is a silicone rubber roll having a hardness of 50 ° and the pressing force is 1 to 1.5 kg / cm ²
And In this way, the image obtained on the plain paper was clear, and a high-quality image having good fixability could be obtained. The recording time was shortened to 20 Sec-4 mSec = 16 mSec every time there was a non-recorded portion and a single color portion corresponding to one raster of the recording apparatus in the recorded image.

Example 2 Image forming element composed of components shown in Tables 5 to 8
D _{4 to} D ₁ (D ₄ in Table 5, D ₃ in Table 6, D ₂ in Table 7, D ₁ in Table 8
(Particle size; 8 to 12 μm) are dispersed in polymethylmethacrylate so that each of them has an equal amount, and this is dried on a base material made of polyimide having a thickness of 6 μm to a dry film thickness of about 2 to 3 μm. To form a transfer recording layer,
Transfer recording medium 2 was obtained by drying.

The sensitizers or photoinitiators in the image forming elements (D _{4 to} D ₁ ) shown in Tables 5 to 8 are about 370 to 420 nm and about 420 to 500, respectively.
nm, about 500 ~ 550 nm, absorbs light in the band of about 550 ~ 600 nm,
Start the reaction.

The transfer recording medium 2 thus prepared was wound in a roll shape, incorporated into the same transfer recording apparatus as that used in Example 1 as the supply roll 2, and recording was performed by this apparatus.

In this embodiment, the thermal head 4 is controlled so that the heating resistor is not energized when the image forming element is transferred, and is energized to generate heat when the image forming element is not transferred. When this heat is generated, the energizing energy is 0.8w / dot x 2.0mSec.

First, in order to form the non-recorded portion, all the heating resistors are energized, and the light sources 3b to 3e are sequentially moved at intervals of 1 mSec for 4 mSec.
After that, the image forming element of the transfer recording layer is changed so that not all of the image forming element is transferred, and then the transfer medium 10 is conveyed by a stepping motor (not shown) and a heat roll 8 which is heated and irradiated by light. Then, the same processing was performed again, and this operation was repeated to form a non-recorded portion (No. 1 in Table 9) on which the image forming element was not transferred.

Next, all the heating resistors are energized, and the light sources 3b, 3d, and 3e are sequentially irradiated at intervals of 1 mSec by 4 mSec each, and the image forming element D ₂ of the transfer recording layer of the portion contacted with the thermal head,
After changing all of D ₃ and D ₄ to the non-transferred state, the transferred medium 1 is conveyed by a stepping motor (not shown) and a heat roll 8 and the same process is performed again, and this operation is repeated and the image is repeated. A transfer image corresponding to the solid print portion (No. 2 in Table 9) including only the forming element D ₁ was formed.

Furthermore, energize all the heating resistors and turn on the light sources 3b and 3d for 1m in sequence.
Irradiate 4 mSec at intervals of Sec, and image forming element D ₃ ,
After changing all of D ₄ to a non-transferred state, the medium to be transferred 1 is conveyed by a stepping motor (not shown) and a heat roll 8 and the same processing is performed again, and this operation is repeated and the image forming element D is repeated. A transfer image corresponding to the solid print portion (No. 3 in Table 9) consisting of ₁ and D ₂ was formed.

Hereinafter, except that the respective light sources 3c to 3f are combined and irradiated as shown in Table 9, the solid printing section No. 4 including the combination of the image forming elements as shown in Table 9 is similarly used. ~ 16
And a transfer image corresponding to the above was formed.

Further, the image forming element was transferred in the same manner as in Example 1.

The optical density in the minute portion corresponding to the heat-generating resistor of the thermal head in the obtained solid print portion was measured using a microdensitometer, and the results are shown in Table 9.

As shown in Table 9, when the transfer recording medium of this example was used, 16 kinds of optical density gradations (0.06 to 1.20) could be expressed including the non-recorded portion.

Further, using the above-mentioned apparatus, the transfer recording medium 2 was used to form an image in which a halftone was expressed as follows.

The image signal input to the apparatus is an image to be recorded (original image) based on the relationship between the combination of the image forming elements obtained as described above and the optical density of the recorded image. Is obtained by analyzing. Therefore, in the present embodiment, the recorded image is represented by 16 density gradations.

First, when the image in one raster is not recorded or has no single tone, the image in one raster is formed by the following four steps.

First, at the start of transfer image formation, based on the image signal corresponding to the optical density of 0.12 exhibited by the image forming element D ₁ , the heating resistor corresponding to the mark signal is not energized, and the heating resistor not corresponding to the mark signal. Is energized for 2 mSec to generate heat, and at the same time, the light source 3c is turned on, and light is uniformly irradiated for 4 mSec.
The image forming element D ₁ on one line of the thermal head, which is on the heating resistor that is generating heat, is changed to a non-transferred state in the subsequent transfer step.

Next, when 1 mSec has elapsed after the end of the irradiation by the light source 3c, the process for the image forming element D ₂ is started next.

That is, based on the image signal corresponding to the optical density of 0.27 exhibited by the image forming element D ₂ , the heating resistor corresponding to the mark signal is not energized, and the heating resistor not corresponding to the mark signal is energized for 2 mSec. Light source 3e is turned on and 4
Light for a period of mSec is uniformly radiated to change one of the image forming element bodies D ₂ on one line of the thermal head, which is on the heat-generating heating element, to a non-transferred state.

Hereinafter, after the irradiation of the light source 3e, the formation of the transfer image is similarly completed for the image forming elements D ₃ and D ₄ with an interval of 1 mSec.

An image in one raster is formed by each processing for D _{1 to} D ₄ described above.

When all the images in one raster were unrecorded, all the heating elements were energized and the fluorescent lamps of 3c, 3e, 3b and 3d were simultaneously and uniformly irradiated with 4 mSec.

When the image in one raster has a single color tone, all the heating elements are energized to raise the melting temperature of the image forming element which is not involved in the desired color tone formation uniformly at the same time with 4 mSec. Irradiated.

Recording time per raster is 20mSec, 4mS as above
Since it is different from ec and 4 mSec, the transfer recording layer was transferred to the plain paper 10 having a smoothness of 10 to 30 seconds at a variable speed using a stepping roller as in Example 1.

In this way, the image obtained on the plain paper was clear, and a high-quality image having good fixability could be obtained. The recording time is 20 Se every time there is an unrecorded portion and a single tone portion corresponding to one raster of the recording device in the recorded image.
The time was reduced by c-4mSec = 16mSec.

[Advantages of the Invention] When the above-described image forming method of the present invention is used, a transfer recording medium whose physical properties change rapidly only when light and heat energy are applied at the same time. Compared with the method that uses only heat that affects the temperature and the method that uses a transfer recording medium that changes the characteristics only with light energy, the environmental stability is higher, and a high-definition image can always be obtained stably and reciprocating. Without moving in a single direction to form an image and without recording in one raster or in the case of a single color or a single tone, the time of image formation is significantly shortened, so high speed recording is possible. It was

[Brief description of drawings]

FIGS. 1a, 1b, 1c and 1d are graphs for explaining the principle of transfer image formation when a transfer image is formed by heat energy of light, where the horizontal axis represents time and the vertical axis represents In the same order, the surface temperature of the heating element, the surface temperature of the transfer recording layer, the viscosity of the transfer recording layer, and the glass transition point of the transfer recording layer are shown. Figures 2a, 2b, 2c, 2d and
FIG. 2e is a partial cross-sectional view showing the relationship between the multicolored transfer recording medium used in the present invention and the thermal head. FIG. 2f is a partial cross-sectional view showing the relationship between the multicolored transfer recording medium used in the present invention and the medium to be transferred. FIG. 3 shows a method 1 for realizing halftone expression in the image forming method of the present invention.
It is a figure which shows an example. FIG. 4 is a cross-sectional view of an apparatus for transferring by the transfer recording method of the present invention, and FIG. 5 is a graph showing the spectral characteristics of the fluorescent lamp in the apparatus of FIG. Figure 6 shows
FIG. 7 is a schematic drive timing chart having no recording according to the present invention, and FIG. 7 is a schematic drawing of a recording sample for explaining FIG. 1: Transfer recording medium 1a: Transfer recording layer 1b: Substrate 2: Supply roll 3a: Black light 3b: Fluorescent lamp for diazo copying machine 3c: High color rendering blue fluorescent lamp 3d: High color rendering green fluorescent lamp 3e: High color rendering green fluorescent Lamp 4: Thermal head 5: Control circuit 7: Heater 8: Heat roller 9: Pinch roller 10: Recording paper 11: Winding roll 12: Recorded image 17: Lighting control circuit f ₁ : Short-wavelength transmission filter f ₂ : Sharp Cut filter T ₁ : Recording time for 1 raster in no recording, single color or single gradation T ₂ : Recording time for 1 raster in halftone or multi-color recording T ₃ : Recording time in non-recording 7b area T _4: Duration at halftone or multi-color region 7a T _5: recording time 7b in the region of the non-recording 7c: not at all recorded area 7a on the recording paper 10, c: half tone or multicolor area on the recording paper 10 t ₂₁ : Recording time for yellow only or OD = 0.80 * only t ₂₂ : Magenta only or OD = 0.1 Recording time for 2 only t ₂₃ : Recording time for cyan only or OD = 1.20 only t ₂₄ : Recording time for black only or OD = 0.27 * OD: Optical density optical density λ ₁ : Common to all image forming elements Wavelength sensitive area λ ₂ : common wavelength sensitive area for cyan and OD = 1.20 λ ₃ : common wavelength sensitive area for yellow and OD = 0.80 λ ₄ : common wavelength sensitive area for black and OD = 0.27 λ ₅ : magenta And OD = 0.12 common wavelength sensitive region

Claims (3)

[Claims] 1. A transfer recording layer comprising two or more types of image-forming elements exhibiting different color tones or optical densities on a substrate,
The image forming element has a sensitive component whose physical properties change the transfer characteristics when heat and light energy are applied, and the heat and light energy conditions for changing the physical properties are as follows. Different conditions for each color tone or optical density and different color tone or optical density 2
Transfer recording, characterized in that conditions common to each combination of one or more combinations of two or more types selected from the one or more types of image forming elements as desired coexist. Medium. 2. A transfer recording layer comprising two or more kinds of image-forming elements exhibiting different color tones or optical densities on a substrate,
The image forming element has a sensitive component whose physical properties change the transfer characteristics when heat and light energy are applied, and the heat and light energy conditions for changing the physical properties are as follows. Different conditions for each color tone or optical density and different color tone or optical density 2
A recording image is recorded on a transfer recording medium in which two or more kinds of image-forming elements selected from two or more kinds as desired are combined and one or more combinations are common in each combination. A step of sequentially forming a transfer image one raster at a time by applying light and heat energy under conditions corresponding to information and conditions different depending on the color tone or optical density of the image forming element, and transferring the transfer image to a transfer medium A multicolor or halftone image forming method including the step of forming two or more kinds of image forming elements that have common energy application conditions for changing the physical properties in forming the transfer image in the one raster. When at least one set of transfer characteristics is changed, heat and light energy are transferred to the transfer recording layer under at least one energy application condition common to these image forming elements. Image forming method comprising applying in accordance with recording information in a portion corresponding to a star. 3. When there are two or more combinations of two or more kinds of image-forming elements having a common condition of energy application for changing the physical properties, the heat of different conditions corresponding to each combination. And all of the light energies at once, or the different conditions are grouped so that at least one group consisting of two or more kinds can be formed, and each group has 1 heat and light energy of the conditions in the group. The image forming method according to claim 2, wherein the image is applied to a portion corresponding to one raster of the transfer recording layer every time according to the recording information.