JPS62144993A - Method and transfer recording medium for forming intermediate tone image - Google Patents

Abstract

PURPOSE:To transfer high-quality images even on an ordinary paper having a low surface smoothness, by a system wherein a transfer recording layer is provided in which two or more kinds of image forming elements differing in energy application conditions for changing the physical properties thereof are mixed in varying mixing ratios, two or more kinds of energy are applied to form a transfer image on a transfer recording medium, and the transfer image is transferred onto a transfer recording material. CONSTITUTION:A transfer recording medium 1 comprises a transfer recording layer 1a in which two or more kinds of image forming elements 1aa differing in the energy application conditions for changing the physical properties thereof governing the transfer characteristics are mixed in varying mixing ratios. Two or more kinds of energy lambda1, lambda2, lambda3 under conditions corresponding to optical densities of the image forming elements 1aa-1-1aa-3 are applied to the medium 1 according to recording information, thereby forming a transfer image on the medium 1. The transfer image is transferred onto a transfer recording material. In this intermediate tone image forming method, a transfer image forming step and a transferring step are separate from each other. Since the transfer image is already formed, the transferring step is free of restrictions concerning selective energy application for forming the image, and accordingly, and energy necessary and sufficient for transferring clear images can be applied to the transfer recording medium in accordance with the surface properties of the transfer recording material.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image forming method capable of expressing halftones that can be used in copying machines and various printers, a transfer recording medium used in the method, and a transfer recording medium used in the method. The present invention relates to an image forming apparatus using the method.

[Conventional technology]

In recent years, with the rapid development of the information industry, various information processing systems have been developed, and recording methods and devices suitable for each information processing system have been developed. One such recording method is the thermal transfer recording method, which has been widely used recently because the equipment used is lightweight, compact, noiseless, and has excellent operability and maintainability. .

This recording method generally uses a heat-sensitive transfer medium formed by coating a sheet-like support with a heat-transferable ink made by dispersing a colorant in a heat-melting binder. A heat supply pattern is created by superimposing the ink layer on the transfer medium so that it is in contact with the transfer medium, and applying heat from the support side of the thermal transfer medium using a thermal head or the like to transfer the melted ink layer onto the transfer medium. A transfer recording image corresponding to the image is formed on a transfer medium.

According to this method, plain paper can be used as the transfer medium.

[Problem that the invention seeks to solve]

However, such conventional thermal transfer recording methods are 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 although it is possible to print well on a highly smooth transfer medium, Print quality is significantly degraded on low-quality transfer media.

Furthermore, even among paper, which is the most common transfer medium, highly smooth paper is rather special, and ordinary paper has various degrees of unevenness due to intertwining of fibers. Therefore, in the case of paper with large surface irregularities, the hot-melted ink cannot penetrate into the fibers of the paper during printing and only adheres to the convexities on the surface or the vicinity thereof, resulting in sharp edges of the printed image. The printing quality deteriorated because the image was not printed correctly or part of the image was missing.

In addition, the transfer of the ink layer to the transfer medium is performed only by heat from the thermal head, but there is generally a limit to the amount of heat that can be supplied from the thermal head, and a large amount of recording signals can be heated within a limited time. In order to convert and supply pulses, it is necessary to prevent the time lag in cooling the thermal head to a predetermined temperature between the thermal pulses during recording, as well as to prevent thermal strokes between the heat generating segments that make up the thermal head surface. Furthermore, it has been theoretically difficult to increase the amount of heat supplied from the thermal head. Therefore, high-speed recording is difficult with conventional thermal transfer recording methods.

Furthermore, thermal conduction has a slower response than electricity or light, so when recording with a thermal head, it is generally difficult to control heat pulses to the extent that halftones can be reproduced. The thermal transfer ink layer does not have transfer characteristics capable of expressing gradation. Therefore, it was not possible to express halftones by directly controlling the heat pulses and adjusting the shading of the recorded image.

- On the other hand, in the conventional thermal transfer recording method, due to the recording characteristics mentioned above, it is usually possible to express only two values (printing or not) within one recording pixel; Since it is not possible to express multiple levels of density gradation, when expressing halftones using this recording method, a matrix consisting of multiple pixels is used as the recording unit of the image, and printing is recorded at each pixel that makes up the matrix. The so-called area gradation method has been mainly used, which expresses halftones by controlling the density of the image.

However, when such an area gradation method is used, there is a drawback that it is difficult to obtain good resolution.

In other words, the resolution of an image is basically inversely proportional to the size of the matrix, which is the constituent unit of the recorded image.In thermal transfer recording using the conventional area gradation method, the resolution of the image is basically inversely proportional to the size of the matrix, which is the constituent unit of the recorded image. In order to express this, it is necessary to increase the number of pixels that make up the matrix. Moreover, since there is a limit to reducing the pixel size, the size of the matrix itself inevitably increases, which exceeds the range suitable for obtaining good resolution.

On the other hand, in order to express one recording unit of a recorded image with one pixel and to be able to express multiple density gradations with one recording pixel, the colorant is transferred to the medium when recording one recording pixel. A thermal transfer recording method using a sublimation transfer type transfer recording medium that directly controls the amount of adhesion has been put into practical use in recent years, but it has the drawback of requiring the use of special recording paper (transfer medium). ing.

The present invention provides a halftone image forming method that solves the problems of the conventional thermal transfer recording method described above. The main object of the present invention is to provide a halftone image forming method capable of forming a high-quality transferred image even on commonly used code paper, and a transfer recording medium used in the method.

[Means for solving problems]

The above objects can be achieved by the following invention.

The present invention is characterized in that: (a) it has a transfer recording layer in which two or more types of image forming elements, each having different energy application conditions that change the physical properties governing the transfer characteristics, are mixed in predetermined different blending ratios; (b) A transfer image is formed on the transfer recording medium by applying two or more types of energy to the transfer recording medium under conditions corresponding to the optical density exhibited by the image forming element according to the recorded information. a step of forming;
This is a halftone image forming method characterized by comprising a step of transferring the transferred image to a transfer medium.

That is, in the halftone image forming method according to the present invention, the transfer image formation step and the transfer step are separated, and in the transfer step, since the transfer image has already been formed, the restriction on selective energy application for image formation is lifted. According to the surface properties of the transfer medium, the amount of energy necessary to transfer a clear image can be applied to the transfer recording medium. In addition, the transferred image formed in the printing process is not simply an image with changed properties such as a thermally fused image, but is an image formed by changing the physical properties that govern the transfer characteristics of the transfer layer. By utilizing the difference in the transfer process, reliable transfer can be achieved, and faithful transfer of the transferred image is also possible. For example, when a thermally fused image is used as a transferred image, it is necessary to maintain the thermally fused image completely from the transfer image formation process to the transfer process, or the transferability may deteriorate due to cooling phenomenon between the two processes. Blurring of the image due to heat conduction to the surroundings of the thermally fused image is unavoidable. However, in the case of the present invention, the transferred image is produced by changing the physical properties that govern the transfer characteristics, such as the melting point, softening point, and viscosity at the same temperature of the image forming element in the transfer recording layer. is memorized until the transfer step, and therefore, unless energy is applied to change the physical properties after the 5th transfer image forming step, the transferability of the transferred image will not deteriorate or image blur will occur. Furthermore, even if the surface smoothness of the transferred medium is low, the transfer process can be carried out independently under conditions adapted to that, making it possible to form a high-quality image, and also to prevent the image quality of the transferred image from deteriorating. It is possible to transfer the image to the transfer medium without any trouble.

Further, in the halftone image forming method according to the present invention, the application of signalized energy for forming a transferred image and the application of uniform energy for transfer are functionally separated, and Compared to the case where the signaled energy for is used as energy for transcription at the same time,
Constraints on energy provision will be significantly relaxed. For example, the amount of energy for forming a transferred image only needs to cause a change in the physical properties of the transfer recording layer, and the energy for transfer can be uniform energy without being converted into a signal, so that the desired transfer can be achieved. It can be increased according to the speed, and high-speed recording can be easily realized.

The thermal response speed of the thermal heads used in conventional thermal transfer recording devices is 1 to 5 isec even for the fastest one.
If you try to drive at a faster repetition cycle than that, the temperature will not rise or fall sufficiently within one cycle, resulting in insufficient heating or the temperature not being able to drop completely, causing the heat storage DG9 to increase. Appeared in image quality. This was one of the biggest factors hindering speed-up, but if multiple types of energy are used as in the present invention, for example by combining a thermal head and light irradiation, the transfer characteristics can be controlled even under heat-accumulated conditions. The effectiveness of the heating state that changes the physical properties can be made only during light irradiation, so by irradiating light only during a limited time period around the peak temperature, the temperature after the peak temperature can be reduced as in the conventional method. It becomes possible to make it less susceptible to the influence of the descending speed, and even if a conventional thermal head is used, the recording operation can be performed with a shorter edge-turning cycle, and high-speed recording becomes easy.

Furthermore, the transfer recording medium of the present invention exhibits a predetermined optical density on the transfer medium, and each of the two or more types of image forming elements has different energy application conditions that change the physical properties governing the transfer characteristics. There is a transfer recording layer mixed on the substrate with different compounding ratios, and the conditions for applying energy such as light and heat to the transfer recording layer are controlled according to the density of the image to be recorded. , corresponding to the blending ratio of each image forming element, for example, the number of image forming elements exhibiting the same optical density, or the combination of image forming elements exhibiting different optical densities and the number of transfers thereof; t11 control,
This is transferred onto a transfer medium to express the density gradation of the recorded image.

Therefore, in the method of the present invention, even when a recording unit of an image is expressed by one recording pixel, for example, the number of transfers of an image forming element exhibiting the same optical density as described above, or two exhibiting different optical densities can be reduced. Since one recording pixel is formed by controlling the combination of more than one image forming element and the number of their transfers, it is possible to directly control the optical density exhibited by each recording pixel, and it is possible to directly control the optical density exhibited by each recording pixel. Unlike conventional thermal transfer recording methods that use gradation methods, halftones can be expressed without reducing resolution, and the shading of the image to be recorded can be faithfully reproduced.

Furthermore, as described above, the image forming method of the present invention basically involves the number of transfers of image forming elements exhibiting the same optical density, or the combination of two or more types of image forming elements exhibiting different optical densities. This is a method of expressing halftones by controlling the number of transfers and the number of transfers depending on the recording information and transferring the image to the transfer medium.Furthermore, the temperature and time of heating, for example, when forming the transferred image on the recording layer, are controlled. The amount of transfer per image forming element is controlled by adjusting the energy conditions in stages such as how many years it takes, etc.
It is also possible to express gradations of light and shade divided into more stages.

Even when the above-mentioned control is performed, high-speed recording is possible in the image forming method of the present invention because energy with a fast response such as light can be used in combination.

In the halftone image forming method according to the present invention, the transferred image is formed by changing the physical properties that govern the transfer characteristics of the image forming element, but these physical properties may vary depending on the type of transfer recording medium used. For example, in the case of a transfer recording medium in which the transferred image is transferred in a thermally molten state, it is the melting temperature, softening temperature, or glass transition point, etc.
Further, in the case of a transfer recording medium in which the transferred image is transferred in an adhesive state or in a permeable state to the transfer medium, the viscosity is the same at the same temperature.

Further, the plurality of types of energy used to form a transferred image are arbitrarily selected depending on the type of transfer recording medium used, and for example, light, electron beam, heat, pressure, etc. are used in an appropriate combination.

Therefore, in the transfer recording medium of the present invention, 2MJ
A transfer recording layer having a transfer recording layer whose physical properties governing transfer characteristics change depending on the above energy;
For example, it has a transfer recording layer that forms a transferred image by changing the physical properties governing the transfer characteristics of the image forming element using heat and light energy, based on the principle explained in FIGS. 1a to 1d, which will be described later. Includes things, etc.

Next, the principle of the halftone image forming method of the present invention will be explained with reference to FIGS. 1a to 1d, taking as an example the case where an image is formed by forming a transferred image using light and thermal energy.

The time axes (horizontal axes) of the graphs in FIGS. 1a to 1d correspond to each other. Further, the transfer recording layer contains a polymerization component including a reaction initiator and a crosslinking agent, which will be described later, as a sensitive component. FIG. 1a shows the rise in the surface temperature of the heating element and the subsequent temperature drop when the heating means such as a thermal head is driven to develop heat from time 0 to t3. The transfer recording medium that is in pressure contact with the heating element exhibits a temperature change as shown in FIG. 1b as the temperature of the heating element changes. That is, the temperature rises with a time delay of t, reaches the maximum temperature at time L4, which is also delayed from t3, and thereafter decreases. This transfer recording layer has a glass transition point Tgo, and rapidly softens and decreases in viscosity in a temperature range below Tgo. This situation is shown by curve A in FIG. 1c. After reaching Tgo at time [2], the viscosity continues to decrease until time t4, when the maximum temperature is reached, and as the temperature decreases, the viscosity increases again, and rapidly increases until time t6, when it drops to Tgo. In this case, there is basically no change in the physical properties of the transfer recording layer compared to before heating, and in the next transfer process the temperature Tgo
Only by heating it does the same viscosity change phenomenon as described above occur. Therefore, if the transfer recording layer is brought into pressure contact with the transfer medium and the heat necessary for transfer is applied, for example, heating north of Tgo, the transfer recording layer will be transferred using a mechanism similar to the transfer mechanism of conventional thermal transfer recording. However, in the case of the present invention,
As shown in Figure 1d, when the transfer recording layer is heated and irradiated with light from time L2, the reaction initiator contained in the transfer recording layer is activated by the light irradiation, and the temperature increases the reaction rate. When the temperature rises to a sufficient level, the reaction initiator acts to generate an activated crosslinking agent, which dramatically increases the probability of crosslinking the crosslinkable prepolymer.
Curing of the transfer recording layer progresses.

When heating and light irradiation are performed simultaneously in this manner, the transfer recording layer exhibits a behavior as shown by curve B in FIG. 1C. As the crosslinking reaction progresses, the glass transition point increases, and when the crosslinking ends *lIt! , it changes from Tgo to Tg'. This situation is shown in Figure 1d.

Therefore, when heated in the next transfer step, there will be a difference in physical properties (temperature dependence of viscosity) between the part where the Tg' changes and the part which does not change. Therefore, if the material is heated to a temperature Tr that satisfies, for example, Tgo<Tr<Tg', there will be a portion where the viscosity has decreased and a portion where the viscosity has not decreased, and only the portion where the viscosity has decreased will be transferred onto the transfer medium. Although it depends on the temperature stability accuracy of the transfer process, Tg'-Tgo at this time is preferably about 20° C. or higher. In this way, a transfer image can be formed by controlling heating or non-heating according to the image signal and simultaneously irradiating light. Furthermore, if the glass transition point changes, the softening temperature and melting temperature also change in a similar manner, so the softening temperature and melting temperature can be controlled using the fluctuation range of the glass transition point as a guide.

In addition, the heating temperature in the transfer image forming process is such that the transfer recording layer is heated at 70°C in order to speed up the reaction rate at which the physical properties that govern the transfer characteristics change and to perform the reaction stably.
As mentioned above, good results can be obtained by heating preferably to a temperature of 80° C. or higher.

Examples of the halftone image forming method of the present invention will be described below with reference to the principles of the image forming method described above.

FIGS. 2a to 2d are schematic diagrams showing the relationship between the transfer recording medium, the thermal head, and light irradiation in the transfer image forming step in the image forming method of the present invention.

In this example, thermal energy modulated according to the image signal is applied to the transfer recording medium along with optical energy of a wavelength selected corresponding to the optical density of the image forming element whose physical properties governing the transfer characteristics are to be changed. be done. Here, "modulation" refers to changing the position where energy is applied according to the image signal, and "together" may mean applying light energy and thermal energy at the same time, or It is also possible to apply energy separately.

The transfer recording medium 1 for forming halftone images of the present invention in this example is constructed by providing a transfer recording layer 1a on a base film lb. The transfer recording layer 1a is an image forming element that exhibits a predetermined optical density θ1 by itself, that is, can impart an optical density of 01 to the recorded portion of the transfer medium when it is transferred alone to the transfer medium. 1aa-1~Iaa
-3 or a mixed layer.

Each image forming element 1aa contains, for example, a black coloring material (coloring component), and the three types of image forming elements 1 have wide range of energy application conditions that change the physical properties governing the transfer characteristics.
aa-1 to Iaa-3, and in this example, these are transferred to the transfer layer 1a as follows: 1aa-1: 1aa-2: 1aa-:
It is contained in a blending ratio of 1:2:3.

The type and blending ratio of each image forming element 1aa are as follows:
It is not limited to this example, and may be selected as appropriate depending on the use of the recording medium, and each image forming element 1
The color tone and optical density defined by aa are not limited to black and DI, and the type of coloring material and its content may be changed so that the image forming element exhibits cyan, magenta, yellow or other color tone and optical density. The amount may be appropriately selected and used.

Further, in this example, a transfer recording medium is used which is configured with a transfer recording layer made of image forming elements each exhibiting the same optical density, but the present invention is not limited to this. For example, by combining imaging elements that exhibit different optical densities depending on the energy application conditions to change the physical properties that govern their transfer properties, or by adjusting the energy application conditions as desired. It is also possible to use a transfer recording layer in which image forming elements are mixed in combination such that two or more of the same elements exhibit different optical densities.

In addition to the coloring material, each image forming element 1aa contains a sensitive component (polymerized component) that changes the physical properties that govern its transfer characteristics when light and heat energy is applied. do.

The sensitive components of the three types of image forming elements 1aa-1 to 1aa-3 are appropriately selected so that they have different wavelength dependencies on light energy.

That is, image forming element 1aa-1' (indicated by 1 in the figure)
When heat and light with wavelength λl are applied, crosslinking of the polymerized component contained rapidly progresses and the material is cured. Furthermore, the image forming element 1aa-2 (indicated by 2 in the figure) receives heat and light of λ2,
Further, when the image forming element 1aa-3 (indicated by 3 in the figure) is exposed to heat and light having a wavelength of λ3, the polymerized components contained therein progress to crosslink and harden. Hardened image forming element 1
The viscosity of aa does not decrease even when heated in the next transfer process,
Not transferred to the transfer medium. Note that heat and light are applied depending on the recorded information.

Using a transfer recording medium having the structure described above, an image can be formed by the image forming method of the present invention in the following manner.

First, the transfer recording medium 1 is stacked on the thermal head 20, and light is irradiated so as to cover the entire heated portion of the thermal head 20 while changing the position where thermal energy is applied according to the image signal. The irradiated light is sequentially irradiated with wavelengths necessary to change the physical properties governing the transfer characteristics of the image forming element 1aa. In this example, the image forming element 1aa
consists of three types, 1aa-1xlaa-3, which have different energy application conditions that change the physical properties governing the transfer characteristics, so the wavelength λ0 is set as above accordingly.
, λ2 and λ3 are sequentially irradiated.

That is, first, as shown in FIG. 2a, the transfer recording medium 1.
At the same time, light of wavelength λ1 is irradiated from the side of the transfer recording layer 1a of
0c, 2Of and 20g generate heat. Then, among the image forming elements 1aa-1, the image forming elements to which both heat and light of wavelength λ1 are applied (those with hatching).

Hereinafter, the cured image forming element is indicated by hatching. ) hardens.

Next, as shown in FIG. 2b, the wavelength λ2 is applied to the transfer recording layer 1a.
At the same time, the heating resistors 20a, 20e,
When 20f and 20g are heated, the image forming element 1a
Of a-2, the image forming element to which heat and light of wavelength λ2 are applied is cured. Furthermore, as shown in FIG. 2c, the wavelength λ
In addition to irradiating the light of 3, the heating resistors 20c and 20d
, 20e and 20h, the image forming element to which light and heat have been applied is cured, and finally the uncured image forming element (those without hatching) attempts to record on the transfer recording layer Ia. A transferred image is formed that is expressed in density gradations corresponding to the density of the image to be transferred. This transferred image is transferred to the transfer medium 10 in the next transfer step as shown in FIG. 2d.

In the transfer step performed subsequent to the transfer image forming step shown in FIGS. 2a to 2c, the transfer recording medium on which the transferred image is formed is brought into contact with the transfer medium, and the transfer recording medium side or Heat is applied from the transfer medium side, and the transferred image is selectively transferred to the transfer medium to form an image. 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. Further, in order to perform the transfer efficiently, it is also effective to apply pressure at the same time. Pressure is particularly effective when using a transfer medium with low surface smoothness. When the physical property that governs the transfer characteristics is the viscosity at room temperature, transfer can be performed using only pressure as the energy applied in the transfer process. Heating in the transfer process is
Suitable for obtaining solid halftone images that are stable and have excellent storage stability.

In the transferred image formed in this way, the number of image forming elements to be transferred is controlled according to the recorded image information in accordance with the blending ratio of each image forming element, as shown in FIG. 2d. and is transferred to the transfer medium IO.

In other words, the m-th portion 10e to which the image forming element 1aa is solely transferred exhibits a high optical density as described above,
The unit portion 10c to which only one type of image forming element 1aa-2 is transferred, that is, the portion to which two image forming elements are transferred in accordance with the blending ratio, exhibits an optical density D2, and the image forming element 1aa-2 has an optical density D2. −Unit part where only one type of 3 is transferred +O
f, that is, a portion where three image forming elements are transferred in accordance with the mixing ratio exhibits an optical density D3.

Further, in the m-th portion 10a where the image forming elements 1aa-1 and 1aa-1 are transferred, four image forming elements corresponding to the sum of these mixing ratios are transferred, and the optical density corresponding to this is transferred. Exhibits D4. Similarly, depending on the image information,
Transfer is performed by the combination of image forming elements 1aa-1 to 1aa-3, that is, by the combination of their mixing ratios, according to the density gradation of 7 levels (including the non-recording state Log) according to the number of image forming elements to be transferred. Each record m of the image is formed, and a transferred image in which halftones are well expressed is formed.

In the above explanation, the image forming elements are scattered discretely on the transfer medium (recording paper, etc.) as shown in FIG. 2d, but this is only for convenience of explanation. In reality, the transferred element spreads two-dimensionally on the surface of the transfer medium, and as a result, in the example of Fig. 2d, it corresponds to each heating element (208 to 20 g) of the thermal head. Form each unit part (10a NIOg) correctly.

Here, if each unit portion (IOa N10g) corresponds to one recording pixel, one recording pixel can be expressed with multiple density gradations, and as mentioned earlier, halftones can be expressed without reducing resolution. An image can be formed.

For example, according to the image forming method of the present invention, as shown in Table 5 of Reference Example 1, which will be explained later, the optical density of the image transferred to the transfer recording medium at one recording pixel is 0. 0
It is possible to express in 16 levels of gradation from 6 to 1.20.

In the example explained above in FIGS. 2a to 2d, a method is shown in which the entire area of the thermal head 20 is irradiated with light and the heating resistor of the thermal head 20 is selectively heated to form an image. Heat a certain area of the transfer recording medium uniformly (
In the case of the thermal head 20 shown in FIG. 2a (in the case where all the heating resistors are made to generate heat), a half-tone image can be similarly formed by selectively irradiating light. That is, light energy of a wavelength that is modulated according to the recording signal and that is selected depending on the optical density exhibited by the image forming element whose physical properties governing the transfer characteristics are desired to be changed may be applied together with thermal energy.

Specifically, to describe the example shown in FIG. 2a, instead of generating heat in the heating resistors 20b, 20c, 20f, and 20g, the thermal head 20 uniformly generates heat throughout the heating resistors 20b, 20c, 20f, and 20g. The wavelength λ! is located at the positions corresponding to 20c, 20f and 20g. irradiate with light.

Furthermore, when irradiating light with wavelength λ2, the entire thermal head 20 is made to generate heat, and the heating resistors 20a, 20e, 20
Light is irradiated to a position corresponding to f and 20g. Hereinafter, the same procedure will be applied to the case of irradiating light with wavelength λ3.

In the explanation of Section F, a thermal head was used for convenience as a means for uniformly heating the entire body, but a uniform heating means such as a beat roll or a heating plate may also be used.

In the present invention, in order to record with good resolution, one recording pixel is basically used to express multiple levels of intermediate tones, but of course, if desired, these pixels can be distributed into a matrix to create multiple tones. It is also possible to further increase the number of gradations by using a method of expressing .

Further, in the method for forming a transferred image at high speed, an example has been shown in which the image forming elements have different spectral sensitivities, but this characteristic is not essential to the present invention. For example, if two aids E with different temperature characteristics are made of materials that react to light and heat, they can be distinguished by the thermal energy they provide even though they have the same spectral characteristics. In other words, a temperature-dependent image forming element is used as the image forming element, and the image forming element is uniformly irradiated with light and thermal energy is applied in a manner that varies depending on the recorded information and the optical density exhibited by the image forming element. It doesn't matter if you do it like this.

The transfer recording medium of the present invention exhibits a predetermined optical density and is a transfer medium in which two or more types of image forming elements having different energy application conditions that change the physical properties governing the transfer characteristics are mixed in predetermined different blending ratios. Any transfer recording medium may be used as long as it has a recording layer and can form a transferred image by changing the physical properties of the image forming element in response to the application of multiple types of energy. I can do it.

Examples of the combination of image forming elements to be mixed in the transfer recording layer of the transfer recording medium of the present invention include: a) a combination in which all of the image forming elements exhibit the same optical density; and b) each image forming element. A combination in which the element body exhibits different optical densities depending on the energy application conditions that change the physical properties that govern its transfer characteristics, and (C) image formation where the energy application conditions that change the physical properties that govern its transfer characteristics are the same. Examples include combinations in which two or more of the elements exhibit different optical densities.

As described above, the transfer recording medium of the present invention has physical properties that govern transfer characteristics such as melting temperature, softening point, glass transition point,
Examples of the viscosity include a transfer recording medium in which the image forming element includes a coloring component (coloring material) and a polymerized component as a sensitive component. In this case, by polymerizing the polymerized component of the image forming element, its melting temperature and the like become higher, and the image forming element that is not polymerized forms a transferred image. The image forming element contained in the transfer recording layer contains a sensitive component and a coloring component, and the sensitive component is one that starts a reaction that changes physical properties when irradiated with light and thermal energy, or It is preferable to use a material whose reaction rate for changing physical properties changes rapidly.

The polymerization component is a component that causes a polymerization reaction or a crosslinking reaction, and representative examples thereof include polymers or polymers such as the following (a) to (c).

(a) Crosslinkable prepolymer; (b) Polymerizable prepolymer and crosslinking agent; (c) Polymerizable polymer or oligomer. Examples include acid half ester, polyvinylstyrylpyridium, and polymethylvinylketone.

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 crosslinking agent include ethylene glycol diacrylate, propylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,4-butanediol diacrylate! "r,N'-methylenebisacrylamide and the like.

Examples of the polymerizable polymer 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. Examples include 6-hexanethiol dimethacrylate.

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

When using a polymerizable monomer or oligomer, a polymer such as cellulose acetate succinate or methyl methacrylate-hydroxyethyl methacrylate copolymer may be included in order to improve layer-forming properties.

A reaction initiator is added as necessary to cause the polymerization component to react. Examples of initiators that act using light energy include benzophenone, benzyl, benzoin ethyl ether, 4-
carbonyl compounds such as r'f, N-dimethylamino-4'-methoxy-benzophenone; organic sulfur compounds such as diptylsulfide, benzyl disfiltrate, and decylphenyl sulfide; di-Lert-butyl peroxide, benzoyl peroxide, etc. Peroxide; carbon tetrachloride,
Examples include halogen compounds such as silver bromide and 2-naphthalenesulfonyl chloride; nitrogen compounds such as azobisisobutyronitrile and benzenediazonium chloride; and the like.

In addition, examples of substances that act as reaction initiators upon receiving thermal energy include methyl hydroperoxide, t-butyl hydroperoxide, di-butyl peroxide, and t-butyl hydroperoxide.
-butylcumyl peroxide, peroxyacetic acid, peroxybenzoic acid, acetyl peroxide, propionyl peroxide,
Examples include isobutyryl peroxide, acetone peroxide, methyl ethyl ketone peroxide, diazoaminobenzene, dimethyl-2,2'-azoisobutylade, diphenyl sulfide, benzoyl disulfide, and the like.

In particular, in the structure of the transfer recording layer when a transferred image is formed by receiving both light and thermal energy, the reaction rate is increased by the reaction between the reaction initiator and the polymerization component, which act in response to the above-mentioned light energy. The types of reaction initiator and polymerization component may be selected so as to provide a combination with a large temperature dependence.

'For example, a combination of a polymerizable prepolymer with a functional group such as a copolymer of methacrylic acid ester or acrylic acid ester, a photosensitive crosslinking agent such as tetraethylene glycol diacrylate, and a reaction initiator such as benzophenone or Michler's ketone. can be mentioned.

The coloring component is a component contained in order to form an optically recognizable image, and various pigments and dyes are used as appropriate. Examples of such pigments and dyes include carbon black, yellow lead, molybdenum red, inorganic pigments such as Red Red, Banza Yellow, Benzidine Yellow, Brilliant Carmine 6B, Lake Red C, and Permanent Red F5R.
, organic pigments such as phthalocyanine blue, Victoria blue lake, and fast sky blue, and colorants such as leuco dyes and phthalocyanine dyes.

When incorporating a coloring component into an image forming element, for example, depending on the combination of the above-mentioned three types of image forming elements, the types of image forming elements may be selected so that the image forming elements exhibit the same or different optical densities. and/or change the content.

In addition, the transfer recording layer contains hydroquinone, p-methoxyphenol, p-tert-butyricatechol, 2.2
A stabilizer such as -methylene-bis(4-ethyl-6-Lert-butylphenol) may also be included.

Furthermore, sensitizers such as p-nitroaniline, 1,2-benzoanthraquinone, p-p' dimethylaminobenzophenone, anthraquinone, 2,6-sinitroaniline, Michler's ketone, etc. are used to increase the energy activation of the reaction initiator. It may be included in the transfer recording medium.

In the transfer recording medium used in the halftone image forming method of the present invention in which light energy is used, each of two or more image forming elements mixed in at least a transfer recording layer at a predetermined different blending ratio is It is necessary to have a different wavelength dependence on the applied light energy. For example, when the transfer recording layer is composed of n types of image forming elements having different wavelength dependence on light energy, each type of image forming element has a different wavelength of light, that is, n
The distribution layer of the image-forming element is composed of a combination of sensitive components whose reaction rates change rapidly with light of different wavelengths. As a combination of such sensitive components, for example, by using a sensitizer that is sensitive to approximately 400 to 500 nm and a component that is sensitive to approximately 480 to 600 nm, such as a sensitizer, wavelength dependence can be improved. Two types of image forming elements with different values can be obtained. In this case, at least one recording pixel is mixed in the transfer recording layer at a different mixing ratio for each type of image forming element, so at least one recording pixel is It can be expressed using four types of optical densities (including a non-recorded state), that is, four levels of density gradation.

In this case, the photosensitive range of both is 480~5G0 n
Although the wavelength range of m overlaps, it is also a region with low sensitivity, and by appropriately selecting a light source, it is possible to almost completely separate the two.

Furthermore, by combining these with an azo compound sensitive to 340 to 400 nm or a halogen compound sensitive to 300 to 400 nm, three types of image forming elements having different wavelength dependencies can be used, and these can be used. By combining and transferring, one recorded pixel can be expressed with at least eight types of optical densities (including a non-recorded state), that is, eight levels of density gradation.

The transfer recording medium used in the present invention can be manufactured, for example, as follows.

Polymerizable prepolymers with functional groups, photosensitive crosslinking agents, reaction initiators, sensitizers, stabilizers, colorants, etc., whose energy imparting conditions that change the physical properties that govern their transfer characteristics are the same. By melt mixing method, spray drying method, etc.
A minute image forming element is used. Furthermore, along with a binder such as a polyester resin, two or more types of image forming elements having different energy imparting conditions that change the physical properties governing the transfer characteristics are mixed with a solvent such as ethyl methyl ketone or ethylene glycol niacetate at different predetermined compounding ratios. After thorough mixing in the interior, a film of polyimide or the like is coated with a solvent, and the solvent is removed by drying, for example, at 80° C. for 3 minutes, to obtain a desired recording medium. .

The above example shows a case where the melting temperature, etc. of the part to which multiple types of energy are applied becomes high, but as a transfer recording medium, it is also possible to use a sensitive component that softens or has a low melting temperature, etc. upon receiving multiple types of energy. When used, the energized portion forms a transferred image. Such sensitive components include polymethyl vinyl ketone, polyvinylphenyl ketone, methyl vinyl ketone, copolymers of methyl isopropenyl ketone and ethylene, styrene, etc., copolymers of ethylene and carbon monoxide, vinyl chloride, Examples include copolymers of acrylate and carbon monoxide, polyvinylphenylketone, polyamide-imide, polyamide, polysulfone, and the like.

Next, an example of the image forming process in the image forming method of the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 is a schematic diagram showing an example of an apparatus for carrying out the halftone image forming method of the present invention. This device selectively drives (modulates) a heating means equipped with a plurality of heating elements in accordance with one image number, and also places the shading (lightness and darkness) of the image to be recorded at the position of the driven heating element. optical density)
This method is used to form a transferred image that expresses halftones by irradiating light with different wavelengths corresponding to the
1, for example, the melting temperature or softening point is increased by irradiating light such as ultraviolet rays in a melted or softened state by heating under predetermined conditions, and the irradiation conditions of the light are different. A transfer recording layer 1a in which image forming elements are mixed in a predetermined different blending ratio is formed into a film l.
This is an ink donor film (IDF), which is a transfer recording medium capable of halftone recording, and is disposed on an ink donor film (IDF). In this example, the IDF1 used was of the type described in FIGS. 2a to 2d, which has a transfer recording layer having the structure a described above.

2 is a supply roll wound with IDFI; 3 is a light irradiation means such as a low-pressure mercury lamp, high-pressure mercury lamp, metal octagonal lamp, fluorescent lamp, or xenon lamp for uniformly irradiating light onto IDFI;
Reference numeral 4 denotes a heating means such as a thermal head, which generates heat pulses by a control circuit 5 based on an image signal. Note that as a heating method, it is also possible to use an energization-heating type transfer recording medium in which the transfer recording medium is energized to generate heat, and in this case, 4 is an energizing head that generates an electric pulse for energizing.

The heating means 4 includes a plurality of heating elements 'f- (heating elements refer to, for example, heating resistors shown in FIG. 2a when the heating means is a thermal head, and electrodes when the heating means 4 is a current-carrying head. ). The heating elements may be arranged in rows, in a matrix or in multiple rows. Further, the heating elements include those that are separated from each other, and those that are made of a continuous rod-shaped energized heat generating material separated by a plurality of electrodes, and any of these types may be used.

8.9 is a transfer means, 8 is a heat roll equipped with a heater 7 inside, 9 is disposed opposite to the beat roll 8, and is used to transfer media such as stamp paper, OHP sheet, etc. and IDPI. A pinch roller pinches and suppresses the transfer record 1fi IDF, and I+ is a take-up roll that winds up the transfer recording 1fi IDF. The recorded image 12 is transferred onto the transfer medium 10 and the IDF
separated from

A thermal head 4 applies a heat pulse to the IDPI sent out from the supply roll 2 based on an image signal.

At the same time as the thermal head 4 applies a heat pulse to the IDF1, light of different wavelengths is sequentially irradiated from the lamp 3751 in synchronization with the heat pulse based on the image signal. The principle of the transfer image forming process is as explained in FIGS. 2a to 2C. The lamp 3 shown in the figure is shown schematically.
It is preferable to irradiate light with different wavelengths using a plurality of lamps.

Transfer recording layer 1a is transferred by thermal head 4 and lamp 3.
A transfer image is formed on the transfer medium 10 by the heat roll 8 and the pinch roller 9.

In this case, as described above, what is controlled based on the image signal is basically one selective heating means such as a thermal head, and the control circuit can therefore be simple.

As a result, a compact and highly reliable apparatus can be realized, and stable image formation can be easily performed.

Additionally, both heating and light irradiation can be controlled according to image signals (
Modulation) is also possible. For example, the heat in Figure 2a~
At the same time as in the example shown in FIG. 2C, light is irradiated to a position corresponding to the heating resistor that generates heat. In other words, in the examples shown in Figures 2a to 2d, the light was irradiated in a -. direction, but when controlling both heating and light irradiation, the irradiation position of the light matches the heat generation position of the thermal head. control. In this way, when a wavelength-dependent image forming element is used, the wavelength of the irradiated light is sequentially changed to a wavelength set corresponding to a predetermined blending ratio of each image forming element, while When a temperature-dependent image forming element is used, the heating temperature is sequentially changed to a temperature set corresponding to a predetermined blending ratio of each image forming element.

When both heating and light irradiation are controlled (modulated) as described above, it is advantageous to increase the contrast of changes in physical properties of a transferred image, and a sharp image can be easily obtained. In addition, since the effect on the image when one side deteriorates is halved, it is easy to obtain a highly reliable device.

The image forming apparatus according to the method of the present invention may have a plurality of steps for forming a transferred image, and this is a particularly advantageous method for increasing the speed of recording. In particular, when using a heating stage such as a thermal head driven in accordance with an image signal, it is necessary to repeat heating and cooling of the image forming element at high speed in order to perform high-speed image formation.

For example, when forming an image using the transfer recording medium described above with reference to FIGS. 2a to 2d, suppose that the time required for heating and cooling the image forming element is 4 m5ec, and the transfer image forming step image forming element 1aa with different energy conditions (wavelength dependent floatability)
-1 to 1aa-3 are processed one by one in Figure 2a~
If performed for each of the three processes shown in Figure 2d, it would take at least 4 m5ecx 3
= 12m5ec is required. On the other hand, there are three transfer image forming steps, and they are located sufficiently far apart from each other so that there is no thermal shadow U.
If the roles of processing aa-I, Iaa-2, or 1aa-3 are shared, processing of one scanning line can be performed in parallel, so it can be done in 4 m5ec. In this way, a high-speed recording device that facilitates high-speed processing and can express halftones is obtained.

FIG. 4 is a schematic diagram of an apparatus for carrying out another embodiment of the image forming method of the present invention. In the example shown in FIG. 4, light irradiation is controlled based on an image signal, and heat is uniformly applied.

That is, in the example shown in FIGS. 2a to 2d, instead of causing the heating resistors 20b, 20c, 20f, and 20g to generate heat.

The entire thermal head 20 is made to generate heat uniformly, and the positions corresponding to the heating resistors 20b, 20c, 20f, and 20g are irradiated with light having a wavelength λ1. Also when irradiating light with wavelength λ2, heating resistors 20a, 20e, 20f and 20g
Light is irradiated to the position corresponding to . Hereinafter, the same procedure will be applied to the case of irradiating light with wavelength λ3.

Therefore, 14 is a heater 1 that uniformly heats the IDFI. For example, a heat roller like 8 or a heater arranged on a ceramic base material can also be used. Of course, a temperature sensor and a feedback heater control circuit may be provided for the purpose of sophisticated control of heating temperature. On the other hand, 15
is a lamp array that irradiates light by a control circuit based on an image signal, and is selected depending on the spectral sensitivity of the transfer recording layer 1a.
arrays, laser arrays, liquid crystal shutter arrays, etc. Also, a laser scanning system may be used instead of the lamp array. Furthermore, if the material is sensitive to the ultraviolet region, an ultraviolet lamp array or a method of scanning ultraviolet light with an optical system is used. In this case, since what is basically controlled based on the image signal is light with excellent responsiveness and low diffusion, it is easy to obtain high speed and high image quality.

Note 1. In the process mode shown in FIGS. 3 to 4,
It is also possible to perform heating and then irradiation with light, or conversely, to heat after irradiation with light. The heating and light irradiation surfaces may be in the same direction or may be in the opposite direction to that shown in Figure 1.

Further, in addition to pigments and dyes, a coloring agent or a color developer that develops a coloring agent can be used as a coloring component so that the image forming element exhibits a color tone.

This coloring reaction may be carried out in the transfer image forming step, or may be carried out in or after the transfer step. Furthermore, the recording medium to be transferred may contain, for example, a color developer, which develops color by reaction with the transferred color former. Examples of such color formers include leuco dyes, diazo groups, and the like.

On the other hand, when coloring components such as pigments and dyes that do not use color reaction are included, high-quality halftones with high reproduction accuracy and excellent storage stability of the recording layer medium and post-recording image storage are generally obtained. It is easy to obtain a rendered image.

〔Example〕

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

Reference Example 1 Image forming elements 1aa-1 to 1aa-4 (particle size: s to +2p) composed of the components shown in Tables 1 to 4 were mixed in polymethyl methacrylate (PMM8), each containing Iaa -1:Iaa-2:1aa-3:1aa-4=
Dispersed in a ratio of 1:2:4:8 (weight ratio), and spread it onto a base material 1b made of polyimide with a thickness of 6 μm.
The transfer recording layer 1a shown in FIG. 5 was obtained by coating the layer 11!2 to a dry thickness of about 10 to 14 μm and drying. Note that the image forming elements 1aa-1 to Iaa-4 are formed so that their individual optical densities are approximately equal.

The sensitizers or photoinitiators in the image forming elements shown in Tables 1 to 4 have wavelengths of approximately 450 to 600 nm, approximately 380 to 600 nm, and
450 nm, about 340-380 nm, about 280-3
40 It absorbs light in the r+n+ band and starts a reaction.

In addition, since the sensitizer contained in the image forming element 1aa-1 having the composition shown in Table 1 has a magenta tinge, when this image forming element is transferred to a transfer medium, the image forming element 1aa-1 has a black color. Further, phthalocyanine green is further contained as a coloring agent so that the image forming element 1 has the composition shown in Table 2.
Since the benzoin contained as a sensitizer in aa-2 has a yellowish tinge, phthalocyanine blue is further added as a coloring agent so that the image forming element exhibits a black color when transferred to a transfer medium. ing.

The transfer recording medium 1 thus produced was wound into a roll and incorporated into the apparatus as a supply roll 2.

As shown in FIG. 5, a thermal head 4 of 8 dots/mvn horizontal size line type with heat generating resistors (heat generating bed f) arranged in a row at the edge portion is used to print a transfer recording medium. The base material 1b side of the transfer recording medium 1 was arranged so as to be in contact with the heat generating resistor, and was pressed against the heat generating resistor by the tension of the transfer recording medium 1.

On the other hand, in a portion of the thermal head 4 facing the heating resistor, four types of light sources 3a to 3d each having the spectral characteristics shown in FIG.
/ placed.

The light source 3a is Tb3+ activated (La, Ce, Tb)20
This is a 40W high color rendering green fluorescent lamp that uses 3+0.2Si02.0.9p2O5 as a phosphor, and emits light with the spectral characteristics shown by a in FIG.
Process a-1. The light source 3b uses lEu- as a phosphor.
A 60W diazo copying machine fluorescent lamp using activated (SrMg) 2P207, with a sharp cut filter L-38 (manufactured by Hoya Glass Co., Ltd.) shown at 18 in Figure 5 on its surface.
is provided, and irradiates light with the spectral characteristics shown by b in FIG. 6 through the filter to form an image forming element 1aa-2.
process. The light source 3C is a 60W black light 3C (product name, manufactured by Toshiba), and a sharp cut filter L-18 (manufactured by Hoya Glass Co., Ltd.) shown at 19 in Fig. 5 is installed in front of it. The image forming element body 1aa-3 is processed by irradiating light having the spectral characteristics shown by C in FIG. 6 through the filter. Further, the light source 3d is a 40W health line lamp (trade name, manufactured by Toshiba), which irradiates light with the spectral characteristics shown by d in FIG. 6 to process the image forming element 1aa-4.

In this reference example, the thermal head 4 is controlled such that when the image forming element is transferred to the heating resistor, no current is applied, and when the image forming element is not transferred, the thermal head 4 is energized to generate heat. The energizing energy during this heat generation is 0.8 w/dot x 2
．． It is 0m5ec.

First, in order to form a non-recorded area, all the heating resistors are energized, and the light sources 38 to 3d are sequentially irradiated with 4 m5 ec at intervals of 1 m5 ec, so that all of the image forming elements of the transfer recording layer 1a are After the transfer medium 1 is changed to a state in which it is not transferred, the transfer medium 1 is heated and exposed to light using a stepping motor (not shown) and a heat roll 8, and transported forward, and the same process is performed again. The operation was repeated to form a non-recorded area (il in Table 5) where the image forming element was not transferred.

Next, all the heating resistors are energized, and the light sources 3b and 3C13
d is sequentially irradiated for 4 m5ec at intervals of 1 m5ec, and all of the image forming elements 1aa-2, Iaa-3, and 1aa-4 of the transfer recording layer in the portion that is in contact with the thermal head are not transferred. After changing to transfer medium 1
A stepping motor (not shown) and a heat roll 8
The image forming element body 1aa-1 corresponds to the solid printing section (/L2 in Table 5) consisting only of the image forming element body 1aa-1, that is, the image forming element body 1aa- l/ of the entire image forming element according to the blending ratio of 1
A transfer image consisting of 15 images was formed.

Furthermore, all the heating resistors are energized, and the light sources 3a, 3c, 3
d is sequentially irradiated for 4 m5ec at intervals of 1 m5ec, and the image forming elements 1aa-1, 1aa-3, 1aa
-4 to a non-transfer state, the transfer medium l 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 to form an image forming element. Corresponding to the solid printing part (Makoto 3 in Table 5) consisting of 1aa-2, that is, 2/1 of the entire image forming element according to the blending ratio of the image forming element 1aa-2.
A transfer image consisting of 5 was formed.

Thereafter, a solid printing section 4 consisting of the combinations of image forming elements as shown in Table 5 was prepared in the same manner except that the light sources 3a to 3d were combined and irradiated as shown in Table 5.
Transfer images corresponding to numbers 1 to 16 were formed, respectively.

The portion of the transfer recording medium on which the transferred image is formed is equipped with a 300 W heater 7 and a heat roll 8 made of an aluminum roll coated with silicone rubber of 2 fflff+ thickness.
Plain paper 1 with a surface smoothness of 10 to 30 seconds is conveyed by pinch rolls 9, which are silicone rubber rolls with a hardness of 50".
0 and its transferred image surface, and heated to 90 by heat roll 8.
~! In a state heated to 00°C, the paper 10 was pressed with a pressure of 1 to 1.5 kg/cm2 by the pinch roll 9, and the transferred image of that part was transferred to the Nishitsu paper, as shown in Table 5. Solid print portions A2 to A16 consisting of such combinations of image forming elements were successively formed.

The optical density at a minute portion corresponding to the heating resistor of the thermal head in the obtained solid print area was measured using a microdensity photometer, and the results are shown in Table 5.

Table 5 As shown in Table 5, in this reference example, 16 types of optical density gradations (0.06 to 1.20
) was possible to express.

Example 1 Using the recording device and transfer recording medium used in Reference Example 1, an image expressing halftones was formed in the following manner.

In the case of this embodiment, negative recording is performed because the transfer recording layer 1a whose glass transition temperature increases when light and heat are reduced is used. In this embodiment, the thermal head 4 is controlled such that it is not energized when there is a mark signal (printing is performed), and is energized to generate heat when there is no mark signal (no printing). The energizing energy during this heat generation is 0.8 w/dot x 2
．． It is 0m5ec.

FIG. 7 shows a drive timing chart of the apparatus in the process of forming a transferred image in this embodiment.

The image signal input to the apparatus is determined based on the relationship between the combination of image forming elements obtained in Reference Example 1 and the optical density of the recorded image (original image). It is obtained by analyzing. Therefore, in this embodiment, the recorded image is expressed with 16 density gradations.

First, at the start of transfer image formation, the image forming element 1aa-
Based on the image signal corresponding to the mixing ratio of 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 m5ec to generate heat, and at the same time the light source 3a is turned on. Turn it on, and irradiate the light for 4 m5ec in the direction of -. Then, among the image forming elements 1aa-1 located on the 1st line of the thermal head, those located on the heat generating resistor 1, which is generating heat, are transferred to the subsequent transfer process. to change it to a state where it is not transferred.

When 1 m5ec has elapsed after the irradiation path γ by the light source 3a, processing for the image forming element 1aa-2 is started next.

That is, an image corresponding to the blending ratio of the image forming element 1aa-2 (based on No. 2), the heating resistor corresponding to the mark signal is not energized, and the heating resistor not corresponding to the mark signal is energized.
The light source 3b is turned off at the same time as electricity is turned on for m5ec to generate heat.
Light is uniformly irradiated for 4 m5ec at N, and the image forming element 1aa-2 on one line of the thermal head, which is on the heat generating resistor 1, is transferred and changes to a state where it is not transferred. let

Hereinafter, at an interval of 1 m5ec after irradiation with the light source 3b,
The image forming elements 1aa=3 and 1aa-11 are also processed in the same manner according to the drive timing chart shown in FIG. 7 to form a transfer image (latent image) in one line, and further operations are performed to the north. Formation of all transferred images is completed by repeating the process according to the image signal.

The transfer image formed on the transfer recording medium is conveyed by a heat roll 8 and a pinch roll 9 in synchronization with the repetition cycle of 20 m5ec/line in the drive chart shown in FIG. Depending on the operation, the surface smoothness can be adjusted to 10~
The images were sequentially transferred onto a 30-second paper.

The image obtained in this example was clear, had good fixing properties, and was a high-quality image in which halftones were faithfully reproduced in the 11A pale color of the original image.

Reference Example 2 Image forming elements 1aa-5 and l'aa-6 (particle size: 8 to 12 μm) composed of the components shown in Tables 6 and 7
) in polymethyl methacrylate (PMM8) at 1aa
-5:Iaa-6=1:3,
This was coated onto a base material 1b made of polyimide having a thickness of 6u+ so that the dry film thickness was 2 to 3 scales, and dried to form a transfer recording layer 1a. Note that image forming elements 1aa-5 and 1
aa4 is formed so that the optical densities exhibited by each of these are approximately equal.

The sensitizer in the image forming element 1aa-5 having the composition shown in Table 6 absorbs light in a band of about 350 to 440 nm and starts a reaction. Furthermore, since this sensitizer has a yellowish tinge, this image forming element further contains navy blue as a coloring agent so that it appears black when transferred to a transfer medium.

On the other hand, the sensitizer in the image forming element 1aa-6 having the composition shown in Table 7 absorbs light in a band of about 500 to 600 nm and starts a reaction. Furthermore, since this sensitizer has a magenta tinge, this image forming element further contains phthalocyanine green as a coloring agent so that it appears black when transferred to a transfer medium.

The transfer recording medium obtained as described above was set in an apparatus as shown in FIG.

The heating means for the transfer recording medium in this apparatus is a heater 14 that uniformly heats the A4 horizontal size from the base material 1b side of the transfer recording medium 1, and a heater 14 is provided near the transfer recording medium 1 at a position opposite to the heater 14. A liquid crystal shutter array 21 is provided, which has a horizontal size of A4 and has a plurality of shutters 23 arranged in two rows as shown in FIG. The aperture size of each shutter 23 is 0.4 Xo, 4 m.
The array pitch is 0.5 mm in length and width. Also,
Transfer recording medium 1 of shutter array 21 shown in FIG.
Each shutter 23 of the shutter array 21a on the front side in the direction of movement of the shutter array 21a is provided with a blue filter (product name: Fuji Filter SP l, manufactured by Fuji Photo Film Co., Ltd.) that allows a large amount of light of 500 nm or less to pass through.
Each shutter 23 of 1b is provided with a yellow filter (product name: Fuji Filter SC50, manufactured by Fuji Photo Film Co., Ltd.) that allows a large amount of light of 500 nm or more to pass through.

Furthermore, a 2 kW xenon lamp is installed above the shutter array 21, and a light shield (not shown) is installed so that the light emitted from it passes only through the shutter array, that is, so as not to irradiate the transfer recording medium. It is shaded.

Using the apparatus configured as described above, four types of solid print portions consisting of the combinations of image forming elements shown in Table 8 were formed in the following manner.

First, with the light source 20 turned on, a portion of the transfer recording medium corresponding to the heater is heated to 95° C. using the heater 14, and at the same time each shutter 2 of the shutter array 21a
3 is opened for 28 m5 ec and the transfer recording medium 1 is irradiated with light that has passed through a blue filter, and the portion of the image forming element 1aa-5 that is irradiated with the light is changed into a state in which it will not be transferred in the subsequent transfer step.

Next, all the shutters are closed for 12 m5 ec, and during that time, the transfer recording medium 1 is conveyed by a stepping motor (not shown) and the heat roll 8 to move the transfer recording medium 1 by the processed width under the shutter array 21a. Then, the portion of the transfer recording medium that has been processed by the shutter array 21a moves below the shutter array 21b, and the unprocessed portion of the transfer recording layer 1a moves below the shutter array 21a.

Here, all the shutters of the shutter arrays 21a and 21b are opened for 28 m5 cc to irradiate light. By this irradiation process, the part below the shutter array 21b that has already been treated with the 1T color filter light in the shutter array 21a is further treated with the yellow filter light,
The image forming element 1aa-6 in this area also reacts, and as a result, all the image forming elements in this area will not be transferred in the subsequent transfer process. At the same time, under the shutter array 21a, the first image forming element 1aa
The operation of processing −5 is repeated. Further, the above-described operations were repeated to form a portion corresponding to the non-recorded portion (/L l 7 in Table 8) on the transfer record 331 layer 1a.

Next, the unprocessed portion of the transfer recording medium that has moved below the shutter array 21a is passed through the shutter array 21a'l'- without being irradiated by the shutter array 21a, that is, by the blue filter. or when moving shutter array 2Ib down, all shutters of shutter array 21b are moved to 28m.
It is opened for 5 cc and irradiated with light that has passed through a yellow filter, causing only this portion of the image forming element Iaa-6 to react and not to be transferred. Further, by repeating the above-described operations, an image forming element body 1aa-5 corresponding to the print area A18 formed only from the image forming element body 1aa-5 is formed.
A transfer image consisting of 174 images of the entire image forming element was formed on the transfer recording layer 1a according to the blending ratio.

Furthermore, the unprocessed portion of the transfer recording medium 1 that has moved below the shutter array 2Ia is irradiated with a blue filter at A with all shutters of the shutter array 21a open for 28 rasec, and this portion of the image forming element 1aa-
5 is reacted and not transferred, and when this part moves below the shutter array 2Ib, all the shutters of the shutter array 21b are kept closed, that is, without performing the irradiation process with the yellow filter. The image forming element body 1 corresponds to the solid print area A11L19 formed only from the image forming element body 1aa-6 by passing through the image forming element body 1aa-6.
A transfer image consisting of 374 images of the entire image forming element was formed on the transfer recording layer 1a according to the blending ratio of aa-6.

Finally, without performing the light irradiation process under the shutter arrays 21a and 21b, that is, all the image forming elements of the transfer recording layer la are passed under the shutter array 21 in a state to be transferred in a later transfer step, Image forming element 1a
Solid printing part/L2 formed from a-5 and 1aa-6
0, that is, image forming elements 1aa-5 and 1
Transfer images formed from all the image forming elements of aa-6 were formed on the transfer recording layer 1a.

The portion of the transfer recording medium on which the transferred image is formed is equipped with a 300W heater 7, a heat roll 8 made of an aluminum roll coated with 2ml 11 thick silicone rubber, and a pinch roll 9 made of a silicone rubber roll with a hardness of 50°. It is conveyed by a heat roll 8 and placed on plain paper lO with a surface smoothness of 10 to 30 seconds from the transferred image surface, and then heated to a surface smoothness of 90 to 10 seconds by a heat roll 8.
Pinch roll 9 onto plain paper lO while heated to 0°C.
is pressed with a pressure of 1 to 1.5 kg/am2, and the transferred image of that portion is sequentially transferred to plain paper to form a solid printed area A11L18~ consisting of a combination of image forming elements as shown in Table 8. 20 were formed.

The optical density of a portion corresponding to the size of each shutter 23 of the shutter array of the obtained solid print area was measured using a microdensity photometer, and the results were
Shown in the table.

Table 8 As shown in Table 8, in this reference example, four types of optical density levels, l (0.06 to 1.2
It is possible to express 0).

Example 2 Using the recording device and transfer recording medium used in Reference Example 2, an image expressing halftones was formed as described below.

In the case of this example, light and heat can be studied and the glass transition point is L.
Since the rising transfer recording layer 1a is used, negative recording is performed.

The image signal input to the apparatus is determined based on the relationship between the combination of image forming elements previously obtained in Reference Example 2 and the optical density of the image to be recorded (original image). ) is obtained by analyzing. Therefore, in this embodiment, the recorded image is expressed in four density gradations.

In this embodiment, one line of image signal is combined with a signal for processing the image forming element 1aa-5 and a signal for processing the image forming element 1aa-5.
6 into signals to be processed, and these are sent to shutter arrays 21a and 21b with a time difference of 40m5ec.

I did it manually in this order.

That is, with the light source 20 turned on, the portion of the transfer recording medium that is in contact with the heater is heated to 95° C. by the heater 14, and at the same time, the image forming element 1aa-5 of the image signal is heated.
A predetermined shutter of the shutters 23 of the shutter array 21a is opened for 28 m5ec in accordance with the signal for processing, and the transfer recording medium l is irradiated with light, and the portion of the image forming element 1aa-5 that is irradiated with the light is transferred in a later transfer process. It was changed to a state where it is not transcribed.

Next, all the shutters are closed for 12 m5ec, and during that time the transfer recording medium 1 is transported by a stepping motor (not shown) and the heat roll 8 to the shutter array 21a'.
)"'. Then, the portion of the transfer recording medium that has been processed in shutter array 21a'F moves below shutter array 21b, and the unprocessed portion is in shutter array 21a'F. It's moving.

Here, a predetermined shutter of the shutter array 21b is used to irradiate light onto the transfer recording medium 1 with a gap of 28 m5ec in accordance with the signal for processing the image forming element body 1aa-6 of the image signal LI, and the portion irradiated with the light is Image forming element 1aa-
6 is changed to a state in which it is not transferred in a later transfer step. Then, in this part, a latent image (transfer image) according to the image signal Ll is created.
was formed.

- On the other hand, at the same time as the processing under this shutter array 21b, under the shutter array 21a, in order to form the second column of images, the image forming element body 1aa-5 of the image signal L2 is processed according to the signal. processing was carried out. Furthermore, the above operations were repeated according to the image signal, and transferred images were successively formed.

The transfer recording medium on which the transferred image has been formed is pinched with a beat roll 8 in synchronization with the above-mentioned light irradiation timing, that is, a repetition cycle of 40 m5 ec consisting of irradiation of 28 m5 ec with an interval of 12 m5 ec. The transferred images were sequentially transferred onto plain paper 10 having a surface smoothness of 10 to 30 seconds by the same operation as in Reference Example 2.

The image obtained in this example was clear, had good fixing properties, and was a high-quality image in which halftones were faithfully reproduced in the v:i light of the original image.

〔Effect of the invention〕

As explained above, since the present invention uses a transfer recording medium whose properties change rapidly when multiple types of energy are applied simultaneously, it is not affected by environmental temperature unlike conventional methods. Compared to methods that use only heat or methods that use a transfer recording medium whose characteristics change only due to light energy, this method has higher environmental stability, making it possible to always obtain stable and highly accurate images. Furthermore, for this reason, the storage stability of the transfer recording medium and the storage performance of recorded images have been improved.

Furthermore, with methods that use only heat, for example, the recording speed is controlled by the thermal responsiveness of the system, and it takes a long time to apply the energy necessary for image formation to the transfer recording medium using only one energy source. On the other hand, the present invention uses high-speed recording to control with energy of 2 or more F.

Furthermore, in the present invention, a transferred image can be formed by continuously irradiating light of different wavelengths in a short time, and the number of transfers of an image forming element exhibiting the same optical density can be increased or Directly controls the amount of colored components that form the recorded image by transferring them to the transfer material while controlling the combination of image forming elements of 2 Auxiliary Tool-F that exhibits density and the number of images to be transferred according to the recorded information. For example, it is possible to express density gradations by changing the optical density of one recording pixel as desired, and it is possible to use the area gradation method, which expresses intermediate tones using a matrix composed of multiple pixels as a unit. It is possible to form high-quality images with good halftone expression in a short time without lowering the resolution as in the conventional thermal transfer recording method.

In addition, since the process of forming a transferred image and the process of transferring are independent, conditions suitable for transferring the transferred image to the transfer medium in a high-quality and stable manner can be determined independently of the conditions for forming the transferred image. Can be set freely. Therefore, it is possible to obtain a high-quality image even when a high-quality transfer medium is used, such as not only static paper but also paper with a low surface smoothness, transverse range, etc. At the same time, excellent fixing properties can also be obtained.

[Brief explanation of drawings]

FIGS. 1a to 1d are graphs for explaining the principle of forming a transferred image using light and thermal energy,
FIGS. 2a to 2d are schematic diagrams showing the relationship between the transfer recording medium, the thermal head, and light irradiation in the transfer image forming step in the present invention, and FIGS. 8
Each figure is a schematic diagram of an apparatus used in the image forming method of the present invention, FIG. 6 is a graph showing the spectral characteristics of the light source used in the apparatus shown in FIG. 5, and FIG. 5 is a drive timing chart of the device shown in FIG. 5, and FIG. 9 is a partial plan view of the liquid crystal shutter array used in the device shown in FIG. 1: Transfer recording medium la: Transfer recording layer laa:
Image forming element lb two substrate 2: supply roll
3: Lamp 3a: High color rendering green fluorescent lamp 3b Fluorescent lamp for diazo copying machine 3C Nibrack light 3d Pressure wire lamp 4: Thermal head 5: Control circuit 7: Heater
8: Heat roller 9: Pinch roller O: Recording paper 1: Winding roll 12: Recorded image 14: Heater 15: Lamp array 16.17: Lighting control circuit 18: Sharp cut filter - 3819: Sharp cut filter L-1^20: White light source 2I: @ Crystal shutter array 21a: Shutter array 21b = Shutter array 22: Shielding control circuit 23: Shutter 24a:
Blue filter 24b: yellow filter

Claims (1)

[Claims] 1) A transfer recording having a transfer recording layer in which two or more types of image forming elements having different energy application conditions that change the physical properties governing the transfer characteristics are mixed in predetermined different blending ratios. A step of forming a transferred image on a transfer recording medium by applying two or more types of energy to the medium under conditions corresponding to the optical density exhibited by the image forming element according to recorded information, and a step of forming the transferred image on the transfer recording medium. A method for forming a halftone image, comprising the step of transferring it to a medium. 2) The halftone image forming method according to claim 1, wherein each of the image forming elements exhibits the same optical density. 3) The halftone image forming method according to claim 1, wherein each of the image forming elements exhibits different optical densities depending on energy application conditions that change the physical properties governing the transfer characteristics thereof. 4) The halftone image forming method according to claim 1, wherein two or more of the image forming elements exhibit different optical densities under the same energy application conditions for changing the physical properties governing their transfer characteristics. 5) Any one of claims 1 to 4, wherein the energy applied to the transfer recording medium to form a transfer image is two or more types selected from the group consisting of heat, light, and pressure. The halftone image forming method described in . 6) The halftone image forming method according to any one of claims 1 to 4, wherein the energy applied to the transfer recording medium to form the transfer image is heat and light. 7) The halftone image forming method according to claim 6, wherein the different energy application conditions for each of the two or more types of image forming elements are different wavelengths of light energy. 8) The intermediate according to claim 7, wherein thermal energy modulated according to recorded information is applied together with optical energy of a wavelength selected depending on the type of image forming element whose physical properties governing its transfer characteristics are to be changed. Toned image forming method. 9) Halftone image formation according to claim 7, in which optical energy of a wavelength that is modulated according to recorded information and that is selected depending on the type of image forming element whose transfer characteristics are desired to be changed is applied together with thermal energy. Method. 10) The halftone image forming method according to claim 9, wherein the thermal energy is also modulated according to the recorded information. 11) The halftone image forming method according to claim 6, wherein the different energy application conditions for each of the two or more types of image forming elements are different temperatures of thermal energy. 12) selectively driving a single heating means having a plurality of heating elements in accordance with the recording information, and at least at the position of the driven heating element in accordance with the optical density of the image to be recorded; The halftone image forming method according to claim 6, wherein an image expressing halftones is formed by irradiating light of different wavelengths. 13) A transfer recording medium having a transfer recording layer in which two or more types of image forming elements having different energy application conditions for changing the physical properties governing the transfer characteristics are mixed in predetermined different mixing ratios. . 14) The transfer recording medium according to claim 13, wherein each of the image forming elements exhibits the same optical density. 15) The transfer recording medium according to claim 13, wherein each of the image forming elements exhibits different optical densities depending on energy application conditions that change the physical properties governing the transfer characteristics thereof. 16) The transfer recording medium according to claim 13, wherein two or more of the image forming elements exhibit different optical densities under the same energy application conditions that change the physical properties governing the transfer characteristics. 17) Claim 13, wherein the energy for changing the physical properties governing the transfer characteristics of the image forming element is two or more types selected from the group consisting of heat, light, and pressure.
17. The transfer recording medium according to any one of items 1 to 16.