JP2001239763A - Transfer material for forming substrate and method for thermal transfer recording - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an image having high gradability by melt thermal transfer recording with a relatively low energy consumption amount. SOLUTION: A transfer material 1 for forming a substrate is used to form a substrate layer for thermally transferring a heat fusible coloring ink on a material to be transferred. The material 1 comprises a support 2, and a transparent or white ink layer 3 provided on the support 2 and containing the heat fusible transparent or white ink. In this case, the layer 3 has a plurality of recesses 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer material for forming a base and a transfer recording method, and more particularly to a transfer material for forming a base layer for thermally transferring a hot-melt color ink onto a transfer material. The present invention relates to a thermal transfer recording method for forming an underlayer on a transfer material prior to thermal transfer of a heat-meltable color ink onto a transfer material for forming a base and a transfer material.

[0002]

2. Description of the Related Art Hitherto, the recording of a face image for personal authentication on a license, a passport, a credit card, a membership card, or the like has been mainly performed by a sublimation type thermal transfer recording method. In this sublimation type thermal transfer recording method, a transfer ribbon formed by coating a sublimable (or heat transferable) dye on a film so as to be capable of thermal transfer is overlapped with a transfer material having a receptor layer capable of receiving the sublimable dye, Based on image data prepared in advance, the thermal transfer ribbon is selectively heated by a thermal head or the like, and a desired image is sublimation-transfer-recorded on a material to be transferred. It is widely known that according to this method, a color image with rich gradation can be easily recorded.

However, the sublimation type thermal transfer recording method is as follows.
Since the material that can be dyed with the sublimable dye is limited, there is a disadvantage that the material that can be used as the material to be transferred is limited. In addition, sublimable materials generally have a disadvantage that they are inferior in image durability such as light resistance and solvent resistance.

As a thermal transfer recording method, a fusion type thermal transfer recording method is known in addition to a sublimation type thermal transfer recording method.
The fusion type thermal transfer recording method is to selectively heat a transfer ribbon formed by coating a film in which a color pigment or dye is dispersed in a binder such as a resin or wax, and apply the color pigment or dye to a material to be transferred. The desired image is recorded by transferring the entire binder. According to this method, an inorganic or organic pigment which is generally said to have good light resistance can be selected as a coloring material. Further, since the resin, wax, and the like used for the binder can be devised, the solvent resistance can be improved. Further, the material to be transferred is not particularly limited as long as it has an adhesive to the binder, and various materials can be used.

However, in the fusion-type thermal transfer recording method, a dot area gradation method is used in which gradation is recorded by changing the size of dots to be transferred. Sensitive. In other words, if the surface of the material to be transferred has irregularities, poor transfer may occur, making it difficult to control the dot size satisfactorily, and the gradation may decrease.

Various proposals have been made to solve such a problem. As one of the methods, a method using a transfer material having a porous image receiving layer has been proposed. According to the method, a transfer material provided with minute light on the image receiving layer is used,
Transfer is performed by infiltrating the heat-meltable ink into the micropores. According to this method, it is known that an image with rich gradation can be obtained. However, since the material to be transferred is limited to one having a porous image receiving layer, the advantage of the fusion type thermal transfer recording method is obtained. Is sacrificed.

As another proposal for solving the problem in the fusion type thermal transfer recording method, before transferring color ink, an ink consisting only of a binder containing no coloring material is previously transferred to an image receiving surface of a material to be transferred. There is known a precoat transfer method in which an image receiving surface is smoothed by this and a colored ink is transferred thereon to perform recording. According to this method, since the unevenness of the image receiving surface of the transfer material can be reduced, the colored ink can be reliably transferred. Therefore, the dot size can be finely controlled, and an image with rich gradation can be obtained. Further, since the transfer material only needs to have adhesiveness to the pre-coated ink, there is an advantage that the selection range of the material used for the transfer material is widened. That is, if the precoat transfer method is used, a color image with rich gradation can be formed without impairing the advantages of the fusion type thermal transfer method.

However, the above-mentioned precoat transfer method still has the following problems. In other words, the precoat transfer can reduce the unevenness of the material to be transferred and improve the gradation, but the precoat transfer cannot completely eliminate the unevenness and print dots smaller than the remaining unevenness. Is difficult. In particular, it is difficult to express an image in a low density area.

Further, in order to reduce the irregularities of the material to be transferred, it is necessary to make the thickness of the precoat ink layer larger than the thickness of the colored ink layer. Therefore, the transfer of the precoat ink layer requires a larger energy than the recording energy for recording the colored ink. In addition, unlike the transfer of the colored ink, the transfer of the precoat ink needs to be performed over the entire image forming area in order to reduce the unevenness of the material to be transferred.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to enable formation of an image with rich gradation by fusion type thermal transfer recording.

Another object of the present invention is to make it possible to form an image rich in gradation with a relatively low energy consumption by a fusion type thermal transfer recording.

[0012]

In order to solve the above-mentioned problems, the present invention provides a transfer material for forming a base used for forming a base layer for thermally transferring a heat-meltable color ink on a material to be transferred. Comprising a support and a transparent or white ink layer provided on the support and containing a heat-fusible transparent or white ink, wherein the transparent or white ink layer has a plurality of concave portions. A transfer material for forming a base is provided.

Further, the present invention heats a base-forming transfer material provided with a transparent or white ink layer containing a heat-meltable transparent or white ink to thermally transfer the transparent or white ink onto a material to be transferred. Forming an underlayer on the material to be transferred, and thermally transferring the color ink onto the underlayer by heating an image forming transfer material provided with a color ink layer containing a heat-meltable color ink. And a step of forming the underlayer, wherein the step of forming the underlayer is performed so that a plurality of concave portions and convex portions are formed on the surface of the underlayer.

In general, irregularities inherent in the material to be transferred are irregularly distributed, and their sizes are also irregular. Such irregularities adversely affect the image quality as described above.

On the other hand, according to the present invention, a base layer is provided on a transfer material. Therefore, according to the present invention,
Irregularities unique to the material to be transferred can be reduced.

Further, as described above, this underlayer has a plurality of concave portions and convex portions on the surface. When these concave portions are provided at a higher density than the resolution of the image formed by the colored ink on the base layer, all the dots of the colored ink are formed at the positions of the concave portions. When the concave portions are provided at a high density as described above,
Since the opening width of the concave portion is inevitably narrow, the capillary phenomenon can be used for transferring the color ink. Therefore, not only large dots but also small dots can be reliably recorded, and an image with rich gradation can be formed.

According to the present invention, it is possible not only to form an image with rich gradation, but also to reduce power consumption. As described above, a plurality of concave portions and convex portions are provided on the surface of the underlayer. When a fusion type thermal transfer recording method using a thermal head or the like is used for forming the underlayer having such a structure, it is not necessary to thermally transfer a transparent or white ink having thermal fusibility to the entire surface of the substrate. That is, the transparent or white ink may be thermally transferred only to the area corresponding to the convex portion. Therefore, for example, when the base layer is formed so that the concave portions and the convex portions form a checkerboard-shaped arrangement pattern, the power required for forming the base layer can be reduced by half as compared with the related art.

In the present invention, the concave portions of the underlayer need not be regularly arranged as long as they are distributed at a sufficiently high density. However, usually, the concave portions are regularly arranged. As described above, the underlayer can be formed by a fusion-type thermal transfer recording method using a thermal head or the like. Therefore, the underlayer is
For example, it is easy to form the concave portions and the convex portions so as to form a checkerboard pattern, or to form the plurality of concave portions so as to form a lattice-shaped groove portion.

In the present invention, the thermal transfer of the colored ink is performed by applying each of the yellow, magenta, and cyan inks to the first region corresponding to the plurality of concave portions of the underlayer and to the plurality of convex portions of the underlayer. Preferably, the transfer is performed by alternate transfer in which thermal transfer is performed only to any one of the second regions. For example, when these colored inks are alternately transferred, the transfer can be reliably performed by thermally transferring the yellow ink to the first region prior to the thermal transfer of the magenta ink and the cyan ink. In this case, it is more preferable to perform thermal transfer in the order of yellow, magenta, and cyan. Further, prior to the thermal transfer of the yellow ink and the magenta ink, the cyan ink may be thermally transferred to the first area. In this case as well, the transfer can be performed reliably. When the cyan ink is thermally transferred to the first area prior to the thermal transfer of the yellow ink and the magenta ink, it is more preferable to perform the thermal transfer in the order of cyan, magenta, and yellow.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a perspective view schematically showing a transfer material for forming an underlayer according to the first embodiment of the present invention. The underlayer transfer material 1 shown in FIG. 1 has a structure in which a transparent or white ink layer 3 is formed on one surface of a support 2.
In the ink layer 3, concave portions 4 each having a bottom surface formed of the support 2 are provided in a lattice shape, thereby forming irregularities on the surface of the transfer material 1.

As the support 2 constituting the transfer material 1, for example, a synthetic resin film such as polyester or polyimide having a thickness of about 2 to 6 μm can be used.

The ink layer 3 can be composed of a heat-meltable colorless transparent or colored transparent binder. Such binders include, for example, microcrystalline wax, higher fatty acids, higher fatty acid esters, vinyl acetate-vinyl chloride copolymers, and saturated polyester resins, and have a melting point of about 60 ° C to about 100 ° C. It is preferable to have one. Further, the binder used for the ink layer 3 preferably has the same composition as the binder used for the colored ink. In this case, it is possible to improve the affinity and the adhesiveness between the base layer formed by thermally transferring the ink layer 3 and the colored ink. In addition,
The ink layer 3 may optionally contain a white pigment or dye.

The thickness of the ink layer 3 is sufficient to reduce irregularities on the surface of the material to be transferred, and is preferably 3 μm.
About 10 μm.

The recess 4 of the ink layer 3 can have various shapes. The recess 4 may be formed as a groove, for example, as shown in FIG. 1, or may be formed as a hole. The opening width and interval of the concave portion 4 change according to the resolution of the image formed using the coloring ink. The opening width of the concave portion 4 may be smaller than the size of the dot formed by the colored ink on the base layer.
It is preferably about 10 μm to 10 μm.

For the transfer material 1 described above, for example, a plate having the same outer shape as that shown in FIG. 1 is prepared, and a binder such as microcrystalline wax is supported by the gravure coating method using the convex portions of the plate. It can be obtained by applying it on the body 2 and then drying it.

Next, a thermal transfer recording method using the base material forming transfer material 1 shown in FIG. 1 will be described with reference to FIG.

FIGS. 2A to 2D are cross-sectional views schematically showing a thermal transfer recording method according to the first embodiment of the present invention. First, as shown in FIG. 2A, the entire ink layer 3 of the transfer material 1 is transferred onto a recording paper 5 as a material to be transferred to form a base layer. In this case, as shown in FIG. 1, a transfer material 1 in which grooves 4 having a width of 10 μm and an interval of 85 μm are provided in a grid pattern in the ink layer 3 is used. The ink layer 3 is made of microcrystalline wax.
This operation is performed using a 00 dpi thermal head.

Next, as shown in FIG. 2B, the yellow ink 6 is thermally transferred based on the yellow image data. Since the affinity and adhesiveness between the ink layer 3 and the yellow ink 6 are good, when the size of the dot formed by the yellow ink 6 is larger than the opening width of the groove 4, the shape shown in FIG. As shown on the left, yellow ink 6
Is reliably transferred onto the ink layer 3. At this time, the groove 4
Then, since the yellow ink 6 permeates into the inside of the groove 4 due to the capillary phenomenon, a groove corresponding to the groove 4 is formed in the layer formed by the yellow ink 6. Yellow ink 6
In the case where the size of the dot formed by is smaller than the opening width of the groove 4, as shown in the center of FIG. Spreads in the width direction. As a result, the dot size is enlarged to the width of the groove, but the thickness is reduced, so that the desired density can be realized. When the size of the dot formed by the yellow ink 6 is equal to the opening width of the groove 4, the yellow ink 6 penetrates into the groove 4 by capillary action as shown on the right side of FIG. Thus, reliable transfer is realized.

Next, as shown in FIG. 2C, the magenta ink 7 is thermally transferred based on the magenta image data. As described above, new dots are formed in the dots of the yellow ink 6 formed in a size larger than the opening width of the grooves 4 so as to correspond to the grooves 4. Therefore, FIG.
As shown on the left side of (c), even when the magenta ink 7 is transferred to the dots, the capillary phenomenon can be used, so that reliable transfer can be performed. FIG. 2 (c)
As shown in the center of the figure, the groove 4
Magenta ink 7 with a dot size larger than the opening width of
Is thermally transferred onto the ink layer 3 by good affinity and adhesiveness between the ink layer 3 and the magenta ink 7. On the other hand, at the position of the groove 4, the yellow ink 6 in the groove 4 is also melted when the magenta ink 7 is melted, as shown in the center and right side of FIG. Both penetrate into the inside of the groove 4 due to capillary action. Therefore, reliable transfer is realized.

After the transfer of the yellow ink 6 and the magenta ink 7 is completed as described above, the transfer of the cyan ink 8 is performed as shown in FIG. The transfer of the cyan ink 8 is performed by the same mechanism as described for the transfer of the magenta ink 7.

As described above, according to the first embodiment of the present invention, the transfer material 1 for forming the underlayer in which the ink layer 3 is provided with the recess 4 is used. Is formed. Therefore, not only large dots but also small dots can be reliably recorded, and an image with rich gradation can be formed.

Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 3 is a diagram schematically showing addresses of dots for forming an image used in the thermal transfer recording method according to the second embodiment of the present invention. In FIG. 3, white circles indicate non-recording portions, and black circles indicate recording portions.

In FIG. 3, recording is performed at an address where both the vertical and horizontal directions are even numbers, and at an address where both the vertical and horizontal directions are odd, and recording is not performed at other addresses. That is, the dots constitute a checkerboard pattern (hereinafter, such transfer is referred to as alternate transfer). In this recording method, it is not necessary to drive all the heating resistors of the thermal head at the same time, so that the power consumption for recording one line can be reduced by half.

FIG. 4 is a plan view schematically showing the underlayer 3 formed according to the address shown in FIG. In addition,
In FIG. 4, the recording paper 5 is omitted. The underlayer 3 shown in FIG. 3 is formed by performing the above-described alternate transfer using the undercoat transfer material 1 having the transparent or white ink layer 3 formed on one entire surface of the support 2. It is. In the underlayer 3 thus obtained, small recesses 4 arranged in a checkerboard pattern are formed at one dot intervals, as shown in FIG.

FIG. 5 is a plan view schematically showing a structure obtained when the yellow ink 6 is transferred onto the underlayer 3 shown in FIG. FIG. 6 is a sectional view taken along the line AA of the structure shown in FIG.
It is sectional drawing along the line. Note that, in FIG.
Has been omitted. As shown in FIG. 6, the transfer of the yellow ink 6 to the position of the concave portion 4 of the underlayer 3 is performed by the same mechanism as described in the first embodiment. Therefore, even when the dot size of the yellow ink 6 is small, reliable transfer can be performed. on the other hand,
Similarly, transfer of the yellow ink 6 onto the underlayer 3 can be reliably performed because of good affinity and adhesion between the underlayer 3 and the yellow ink 6. It should be noted that since the capillary action cannot be used for transferring the yellow ink 6 onto the underlayer 3, it may be difficult to transfer a dot having a smaller size than the transfer to the position of the concave portion 4.
In such a case, it is preferable to employ one of the following two methods.

The first method is to deal with image processing. Since the addresses of the dots forming the underlayer 3 are known, if the size of the dot to be formed using the yellow ink 6 is smaller than the dot size that can be actually recorded, the underlayer 3 is formed at that position. What is necessary is just to change the size of the dot to be formed appropriately.

The second method is to alternately transfer the yellow ink 6 as well. That is, if the alternate transfer is performed so that the yellow ink 6 is transferred only to the position of the concave portion 4, not only a large dot but also a small dot can be reliably recorded, and an image with rich gradation can be formed. Becomes possible.

Next, a third embodiment of the present invention will be described. The thermal transfer recording method of the present invention is particularly effective for forming an image display such as a passport or a driver's license in which a face image for personal authentication is recorded on a material to be transferred. The face image for personal authentication is for authenticating that the person who owns the image display body is the person, and is desired to be a more realistic image. Therefore, it is necessary to form an image by a recording method rich in gradation.

As described above, in the fusion-type thermal transfer recording method, gradation recording is performed by using the dot area gradation method in which the dot size is controlled by controlling the amount of heat generated by the heating resistor and the like of the thermal head. . In order to form an image rich in gradation by the dot area gradation method, as a matter of course, it is necessary to accurately control the temperature distribution of the heating resistor.

FIG. 7 is a view schematically showing a part of a thermal head used in the thermal transfer recording method according to the third embodiment. As shown in FIG. 7, the thermal head 10
It has a structure in which a plurality of heating resistors 11 are arranged in a line. Each of the heating resistors 11 has a pair of electrodes 1.
2 and 13 are attached, and individual heating resistors 11 are provided.
Power can be supplied independently.

FIG. 8 is a graph showing the temperature distribution of the three adjacent heating resistors R1 to R3 of the thermal head 10 shown in FIG. In the drawing, the horizontal axis represents the heating resistors R1 to R
3 shows the position along the arrangement direction, and the vertical axis shows the temperature. In FIG. 8, the data shown by the solid line is the temperature distribution observed when the heating resistors R1 to R3 are independently heated, and the data shown by the broken line is the same for all the heating resistors R1 to R3. This is a temperature distribution observed when heating is performed, and data indicated by a dashed line is a temperature distribution observed when heating is generated only by the heating resistors R1 and R3.

As is clear from the data shown by the solid line in FIG. 8, when heating is caused alone, the heating resistors R1 to R
3 has a temperature gradient in which the temperature is high in the center and low in the periphery. However, the heating resistors R1 to R
In the case where heating is performed simultaneously in all three, as is apparent from the data indicated by the broken line in FIG. 8, a temperature interference occurs at the boundary between the resistors R1 to R3, so that the original temperature gradient is not realized.

On the other hand, when heating is caused only by the heating resistors R1 and R3, the heating resistor R2 functions as its cooling body, so that the heating resistor R1 and the heating resistor R2 are used.
And the boundary of the temperature distribution between the heating resistor R2 and the heating resistor R3 becomes clear.
The original temperature gradient can be realized. Such a temperature gradient is excellent in controllability, and makes it possible to control the dot size more finely. When performing gradation recording in the fusion-type thermal transfer recording method, it is widely known that alternate transfer as shown in FIG. 3 is performed for such a reason.

FIG. 9 is a graph showing density characteristics when gradation recording is performed by full transfer using all heating resistors and density characteristics when gradation recording is performed by alternate transfer. In the drawing, the horizontal axis represents the heating time by the heating resistor, and the vertical axis represents the image density.

As shown in FIG. 9, when all the transfer is performed,
A density jump occurs in the middle density range. This is because temperature interference occurred between the heating resistors. On the other hand, when the alternate transfer is performed, a smooth density gradient is obtained. Thus, the alternate transfer is suitable for performing faithful gradation recording.

By the way, the face image is yellow, magenta,
And three colors of cyan and cyan, generally, yellow dots are formed at a relatively high density (large size), magenta dots are formed at an intermediate density, and cyan dots are formed at a low density (small size). It is formed. The present embodiment utilizes such a tendency.

FIG. 10A is a diagram schematically showing addresses for forming dots of the underlayer 3 in the thermal transfer recording method according to the third embodiment of the present invention. FIG.
FIG. 0 (b) is a diagram schematically showing addresses for forming dots of yellow ink 6 in the thermal transfer recording method according to the third embodiment of the present invention. Note that FIG.
In (a) and (b), white circles indicate non-recording portions, and black circles indicate recording portions.

In FIG. 10A, recording is performed at an address in which both the vertical and horizontal directions are even, and an address in which both the vertical and horizontal directions are odd, and recording is performed at other addresses. Absent. That is, FIG. 10A shows the address of the alternate transfer. As described above, the power consumption can be reduced by half when a precoat layer requiring more power is formed by such alternate transfer. When the underlayer 3 is formed by this alternate transfer, a recess 4 similar to that shown in FIG. 4 is formed in the underlayer 3.

In FIG. 10B, on the contrary to the address shown in FIG. 10A, the address in which both the vertical and horizontal directions are even and the address in which both the vertical and horizontal directions are odd are shown. Recording is not performed, and recording is performed at other addresses. That is, FIG. 10B shows the address of the alternate transfer reverse to that shown in FIG. When the yellow ink 6 is transferred according to this address, all the yellow dots are formed at the positions of the concave portions 4 of the base layer 3.

FIG. 11 shows the underlayer 3 and the yellow ink 6 according to the addresses shown in FIGS.
FIG. 3 is a plan view schematically showing a structure obtained by forming dots of FIG. FIG. 12 is a cross-sectional view of the structure shown in FIG. 11 taken along line BB. Note that the recording paper 5 is omitted in FIG.

As described above, when a face image is composed of three colors of yellow, magenta and cyan, yellow dots are generally formed with a relatively high density (large size). In fact, for yellow, as shown in FIG.
Many areas of the face image are solid. In such a case, even if the yellow ink 6 does not penetrate into the concave portion 4 for some reason, the yellow ink 6 and the underlayer 3
The high adhesive force between them ensures reliable transfer without causing transfer failure. In this case, a recess similar to the recess 4 of the underlayer 3 is also formed between the dots formed by the yellow ink 6. That is, a surface shape effective for improving the transferability of the magenta ink 7 is formed.

FIG. 13 shows the yellow ink 6 shown in FIG.
FIG. 9 is a cross-sectional view schematically showing a structure obtained by alternately transferring a magenta ink 7 and a cyan ink 8 on the top. As described above, the face image is yellow, magenta,
And three colors of cyan, magenta dots are generally formed at an intermediate density (intermediate size),
Cyan dots are formed with low density (small size). Therefore, as shown in FIG. 13, even if the positions of the dots of the magenta ink 7 correspond to the positions of the recesses 4, the dots of the magenta ink 7 can be strongly adhered to the dots of the yellow ink 6, so that reliable transfer can be achieved. It can be performed. Since the dots of the cyan ink 8 are small and cannot be strongly bonded to the dots of the yellow ink 6, the positions of the dots of the cyan ink 8 should correspond to the positions of the concave portions formed between the dots of the yellow ink. Thereby, reliable transfer can be performed by utilizing the capillary phenomenon. In addition, such recording is performed by changing the recording order of the colored inks.
The order may be yellow, magenta, and cyan.

In the above-described method, the concave portions 4 are formed before the dots of the magenta ink 7 and the cyan ink 8 are formed.
Although the dot of the yellow ink 6 is formed at the position, the dot of the cyan ink 8 may be formed at the position of the concave portion 4 before the dot of the yellow ink 6 and the magenta ink 7 are formed. That is, after the underlayer 3 is formed, the cyan ink 8 is alternately transferred in a pattern opposite to the dots constituting the underlayer 3, and then the yellow ink 6 and the magenta ink 7 are the same as the dots constituting the underlayer 3. The pattern may be alternately transferred. Also in this case, the gradation can be improved for each colored ink.

That is, although the dots of the cyan ink 8 are generally small and cannot be strongly adhered to the underlayer 3,
By associating the positions of the dots of the cyan ink 8 with the positions of the recesses 4, reliable transfer can be performed by utilizing the capillary phenomenon. Further, since the dots of the yellow ink 6 and the magenta ink 7 are generally larger than the dots of the cyan ink 8, the adhesive force with the base layer 3 and the yellow ink 6
Only the adhesive force between the ink and the magenta ink 7 is sufficient,
Therefore, reliable transfer can be performed. In such printing, the printing order of the colored inks may be cyan, magenta, and yellow.

[0057]

As described above, according to the present invention,
Prior to thermally transferring the heat-meltable colored ink onto the transfer material, an underlayer containing a heat-meltable transparent or white ink is formed on the transfer material. Therefore, according to the present invention, the material used for the material to be transferred is not limited.

Since the underlayer has a plurality of concave portions and convex portions, the capillary phenomenon can be used for the thermal transfer of the colored ink. Therefore, not only large dots but also small dots can be reliably recorded, and an image with rich gradation can be formed.

Further, the underlayer having such a structure can be formed, for example, by alternately transferring a hot-melt transparent or white ink. In the alternate transfer, the power consumption is halved compared to the full transfer. Therefore, power consumption can be reduced.

That is, according to the present invention, it is possible to form an image rich in gradation with relatively low energy consumption by the fusion type thermal transfer recording without impairing the advantages of the fusion type thermal transfer recording method.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a transfer material for forming a base according to a first embodiment of the present invention.

FIGS. 2A to 2D are cross-sectional views schematically showing a thermal transfer recording method according to the first embodiment of the present invention.

FIG. 3 is a diagram schematically showing addresses of dots for forming an image used in a thermal transfer recording method according to a second embodiment of the present invention.

FIG. 4 is a plan view schematically showing an underlayer formed according to the address shown in FIG. 3;

FIG. 5 is a plan view schematically showing a structure obtained when yellow ink is transferred onto an underlayer shown in FIG. 4;

6 is a cross-sectional view of the structure shown in FIG. 5, taken along line AA.

FIG. 7 is a view schematically showing a part of a thermal head used in a thermal transfer recording method according to a third embodiment of the present invention.

FIG. 8 is a graph showing a temperature distribution of three adjacent heating resistors R1 to R3 of the thermal head shown in FIG. 7;

FIG. 9 is a graph showing density characteristics when gradation recording is performed by full transfer using all heating resistors and density characteristics when gradation recording is performed by alternate transfer.

FIG. 10A is a diagram schematically showing addresses for forming dots of an underlayer in a thermal transfer recording method according to a third embodiment of the present invention, and FIG. 10B is a diagram showing a third embodiment of the present invention. FIG. 4 is a diagram schematically showing addresses for forming dots of yellow ink in the thermal transfer recording method according to the embodiment.

FIG. 11 is a plan view schematically showing a structure obtained by forming a base layer and dots of yellow ink in accordance with the addresses shown in FIGS. 10 (a) and (b).

12 is a cross-sectional view of the structure shown in FIG. 11, taken along line BB.

13 is a sectional view schematically showing a structure obtained by alternately transferring a magenta ink and a cyan ink onto the yellow ink shown in FIG. 12;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transfer material for base formation 2 ... Support 3 ... Transparent or white ink layer 4 ... Recess 6 ... Yellow ink 7 ... Magenta ink 8 ... Cyan ink 10 ... Thermal head 11 ... Heat generating resistor 12,13 ... Electrode

Claims (12)

[Claims] 1. A transfer material for forming a base, which is used for forming a base layer for thermally transferring a heat-meltable colored ink on a transfer material, comprising: a support; A transparent or white ink layer containing a transparent or white ink, wherein the transparent or white ink layer has a plurality of recesses. 2. The transfer material for forming an underlayer according to claim 1, wherein the plurality of recesses are provided at a higher density than the resolution of an image formed on the underlayer by the colored ink. 3. The transfer material according to claim 1, wherein the plurality of recesses are regularly arranged. 4. The transfer material for forming an underlayer according to claim 1, wherein each of the plurality of recesses forms a groove. 5. The transfer material according to claim 1, wherein the plurality of recesses form a lattice-shaped groove. 6. The method according to claim 1, further comprising: heating a transfer material for forming an undercoat provided with a transparent or white ink layer containing a transparent or white ink which is heat-meltable to thermally transfer the transparent or white ink onto the transfer material; Forming a base layer on the transfer material, and heating the image forming transfer material provided with a colored ink layer containing a heat-meltable colored ink to thermally transfer the colored ink onto the base layer. The thermal transfer recording method, wherein the step of forming the underlayer is performed so that a plurality of concave portions and convex portions are formed on the surface of the underlayer. 7. The thermal transfer recording method according to claim 6, wherein the transparent or white ink layer has a plurality of concave portions. 8. The thermal transfer recording method according to claim 6, wherein the underlayer is formed such that the plurality of concave portions and convex portions form a checkerboard pattern. . 9. The step of thermally transferring the colored ink includes the steps of: transferring each of yellow, magenta, and cyan inks;
Thermal transfer to only one of a first region corresponding to the plurality of recesses of the underlayer and a second region corresponding to the plurality of protrusions of the underlayer, wherein the magenta ink and 9. The thermal transfer recording method according to claim 8, wherein the yellow ink is thermally transferred to the first area before the thermal transfer of the cyan ink. 10. The thermal transfer recording method according to claim 9, wherein thermal transfer is performed in the order of yellow, magenta, and cyan. 11. The step of thermally transferring the colored ink,
Each of the yellow, magenta, and cyan inks is applied to only one of the first region corresponding to the plurality of concave portions of the underlayer and the second region corresponding to the plurality of convex portions of the underlayer. 9. The thermal transfer recording method according to claim 8, further comprising: thermally transferring the cyan ink to the first area prior to the thermal transfer of the yellow ink and the magenta ink. 12. The thermal transfer recording method according to claim 11, wherein thermal transfer is performed in the order of cyan, magenta, and yellow.