JPH07242009A - Thermal transfer recorder - Google Patents

Abstract

PURPOSE:To easily produce a color image with high quality by forming a spacing structure having a specific unit of width in a transferring section wherein a melted transfer dye is vaporized. CONSTITUTION:A transfer section 3 is so constituted that a plurality of roughly square posts 21 provided to be aligned on a bottom face in a dye-housing section 2 at a position corresponding to an opening section 2a having a constant interval with each other so that a periodic spacing structure is formed therein. In the spacing structure of the transfer section 3, both of a width of the post 21 and a distance of an interval thereof are 2mum. That is, a unit width (d) corresponding to one cycle of the spacing structure which is a sum of the width of each of post and distance of the interval is defined by an equation of 0.8mpi(gamma/rhoomega<2>)<2/3d<1.2mpi(gamma.rhoomega<2>) <1/3>. At that time, a concentration of the transfer dye is represented by pi, a surface tension of the transfer dye by gamma, an angle frequency of the periodic heating by omega and a positive integer by (n). Thereby, it is possible to suppress occurrence of a surface wave when the melted transfer dye is vaporized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to transfer a transfer dye to an object to be transferred according to an image signal by an appropriate heat source.
The present invention relates to a thermal transfer recording device that forms a transfer image of continuous gradation.

[0002]

2. Description of the Related Art Conventionally, an object to be transferred such as photographic paper and a thermal transfer recording medium such as an ink sheet are superposed and heated selectively by a heating means such as a laser or a thermal head according to an image signal. However, a thermal transfer recording apparatus that records an image by transferring a transfer dye from a thermal transfer recording medium to a transfer target is widely used.

Among them, in a so-called sublimation type thermal transfer recording apparatus using a heat diffusible dye such as a sublimation dye as a transfer dye, the apparatus is small in size, easy to maintain, has immediacy, and records according to heating energy. Since gradation can be obtained in images and high-quality images comparable to silver halide color photographs can be obtained, in recent years, they have attracted attention as a technique for hard copying images in video cameras, televisions, computer graphics, etc. There is.

However, conventionally, as an ink ribbon used for such thermal transfer recording, a transfer dye is mixed with an appropriate binder resin in a weight ratio of about 1: 1 and a thickness of about 1 μm is formed on a substrate such as a polyester film. The one applied to is used. However, since this ink ribbon is usually disposable, a large amount of waste is generated, which is regarded as a problem from the viewpoint of environmental protection.

Therefore, it has been attempted to improve the utilization efficiency of the thermal transfer recording medium, and one satisfying the demand is a transfer dye of the thermal transfer recording medium such as a transfer dye layer reproducing method or a multiple transfer dye layer constitution method. Examples thereof include a method of reproducing a layer so that it can be repeatedly used, and a method of effectively using a thermal transfer recording medium like a relative velocity method.

[0006]

However, in any of the above-mentioned methods, since the dye is transferred by pressing the transfer dye layer onto the photographic paper, when the color image is obtained, the already transferred dye is transferred. The problem of irreversible transfer to the dye layer, which deteriorates the image quality and damages the image, is unavoidable.

Therefore, an apparatus has been proposed in which a gap is provided between the transfer dye layer and the printing paper to transfer the dye without bringing the transfer dye layer and the printing paper into contact with each other.
In this case, the transfer dye is supplied to the transfer section by flowing in a molten state or by being continuously coated on an appropriate substrate and moving the substrate to the transfer section. Then, based on the image signal, the transfer dye is vaporized by a heating means such as a laser and transferred onto the printing paper.

However, when the transfer recording is carried out by this apparatus, since the transfer dye does not contain a binder, for example, when the laser irradiation is carried out, a surface wave is generated due to a difference in surface tension between a heated portion and a non-heated portion of the transfer dye. Occurs, the transfer dye escapes to the surroundings, and there is a problem that the transfer dye is not vaporized properly.

As described above, a space is provided between the transfer dye layer and the printing paper, and the transfer dye in a molten state is vaporized by a heating means such as a laser according to an image signal, and the transfer dye is transferred and recorded on the printing paper. In the thermal transfer recording apparatus having the above-mentioned structure, reverse transfer does not occur in the transfer dye layer during transfer recording, but it is very difficult to vaporize the transfer dye as desired. .

The present invention has been made in view of the above problems, and an object of the present invention is to appropriately vaporize a transfer dye according to an image signal and perform transfer recording on photographic paper to obtain a high quality image. It is an object of the present invention to provide a thermal transfer recording device that enables easy production of color images.

[0011]

According to the present invention, an air gap is provided between a transfer dye layer and a recording medium to be transferred, the transfer dye is melted and supplied to a transfer portion, and then this is vaporized by a heating means. The present invention is intended for a thermal transfer recording device for transferring onto a recording medium. In the present invention, a spatial structure having a unit width d represented by the following formula is formed in the transfer portion where the melted transfer dye is vaporized. Here, ρ, γ, and ω are the density of the transfer dye, the surface tension of the transfer dye, and the angular frequency of the period in which heat is applied to the transfer dye by the heating means, and n is a positive integer.

0.8nπ (γ / ρω ² ) ^1/3 <d <1.2nπ (γ / ρω ² ) ^1/3 (1) That is, the thermal transfer recording apparatus according to the present invention is )
A spatial structure having a unit width d represented by the formula is formed and configured.

In this case, a laser may be used as a heating means for the transfer dye.

A thermal head may be used as the heating means for the transfer dye.

[0015]

In the thermal transfer recording apparatus according to the present invention, since the spatial structure having the unit width d represented by the above formula (1) is formed, the surface when the transfer dye melted by the heating means is vaporized. Generation of waves is suppressed.

That is, a gap is provided between the transfer dye layer and the printing paper, and the transfer dye in a molten state is heated by a heating means to be vaporized and transferred without contacting the transfer dye layer and the printing paper. When the image is transferred from one part to the photographic paper through the gap, the transfer dye needs to be instantly heated and vaporized, and a difference in surface tension between the heated part and the non-heated part of the transfer dye is generated. Waves are generated. However, the unit width d of the spatial structure provided in the transfer portion is within an allowable range (0.8 to 0.8) centered on an integral multiple of the half wavelength of the surface wave, as shown in the equation (1). Since it is within 1.2 times), the action of canceling the surface wave acts between this surface wave and the spatial structure, and the surface wave is rapidly attenuated. Therefore, the surface wave inevitably generated by instantaneously heating the transfer dye is almost completely suppressed, and the decrease in the transfer amount onto the printing paper is prevented.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of a thermal transfer recording apparatus according to the present invention will be described below with reference to the drawings. This thermal transfer recording apparatus superimposes a transfer target such as photographic paper and a thermal transfer recording medium such as an ink sheet, and selectively heats it in accordance with an image signal by using a heating unit such as a laser or a thermal head. In accordance with an image signal, a transfer dye is transferred from a thermal transfer recording medium to a transfer target to record an image.

First, the first embodiment will be described. This first
As shown in FIG. 1, a main part of the thermal transfer recording apparatus according to the embodiment is a semiconductor laser 1 as a heating means for vaporizing a transfer dye in a molten state, and a glass dye containing part for containing the transfer dye. 2 and.

The above transfer dye has a density ρ at a temperature of 250 ° C.
= 1.0 g / cm ³ and surface tension γ = 20 dyn / cm, which is a disperse dye manufactured by Mitsubishi Kasei Co., Ltd. under the trade name HSR2031, and Mitsui Toatsu Co., Ltd. under the trade name HM1225 as a laser light absorber. 2% by weight was added, and this was heated to a temperature of 160 ° C. to be in a molten state.

The semiconductor laser 1 has a period of 2 μs, an emission wavelength of 780 nm, an output of 40 mW, and emits a pulsed laser beam as shown in FIG. The focus of this laser light is set to 5 × 10 μm by a lens 11 which is an optical system. At this time, the dispersion relation of the surface wave generated by the difference in the surface tension between the heated portion and the non-heated portion of the transfer dye due to the laser beam is expressed by the following equation, where the wave number is k.

Ω ² = (γk ³ ) / ρ (2)

Therefore, assuming that the angular frequency of the laser beam is ω, the wavelength λ of the surface wave is expressed by the following equation.

Λ = 2π (γ / ρω ² ) ^1/3 (3)

From the equation (2), the angular frequency ω of the surface wave is
= 2π × 5 × 10 ⁵ rad / s, and the temperature of the transfer dye is instantaneously raised to 250 ° C. during laser irradiation, so that the wavelength λ of the surface wave is 8.0 μm from the above formula (3).

The dye containing section 2 has a flat housing shape and contains a transfer dye in a molten state to form a transfer dye layer 22. A part of the upper surface of the dye containing section 2 is opened in a predetermined area, and a transfer section 3 is formed on the lower surface of the dye containing section 2 corresponding to the opening 2a. A spacer 12 is provided along the peripheral edge of the opening 2a to form a void portion 13, and a photographic printing paper 14 which is a transfer target is placed on the spacer 12. Therefore, the transfer unit 3
And the photographic printing paper 14 are not brought into contact with each other, and both of them are arranged at a predetermined interval by the void portion 13.

As shown in FIG. 3, the transfer section 3 has a plurality of substantially square columnar columns 21 arranged at equal intervals on the lower surface of the dye containing section 2 corresponding to the opening 2a. Are arranged to form a periodic spatial structure. Each of the columns 21 faces the opening 2a at a height higher than the liquid level of the transfer dye in the dye container 2.

In the spatial structure of the transfer section 3, as shown in FIG. 4, the width of each pillar 21 and the distance between each pillar 21 are both set to 2 μm. That is, the unit width d (= 4 μm) corresponding to one cycle of the spatial structure, which is the sum of the widths of the columns 21 and the intervals between the columns 21, is the heating portion of the transfer dye and the non-heating when the laser irradiation is performed. That is, it corresponds to a half wavelength of the wavelength λ of the surface wave generated by the difference in the surface tension with the portion.

In the thermal transfer recording apparatus according to the first embodiment, since the spatial structure having the unit width d corresponding to one cycle represented by the above formula (1) is formed, it is melted by the laser semiconductor 1. The generation of surface waves when vaporizing the transferred dye is suppressed.

That is, the gap portion 13 is provided between the transfer dye layer 22 and the printing paper 14, and the transfer dye layer 22 and the printing paper 14 are provided.
When the transfer dye in a molten state is heated and vaporized by the laser semiconductor 1 without being brought into contact with and when the image is transferred from the transfer section 3 to the photographic paper 14 through the void section 13,
Since it is necessary to instantly raise the temperature of the transfer dye to vaporize it, a difference in surface tension between the heated portion and the non-heated portion of the transfer dye occurs and a surface wave is generated. However, a unit width d corresponding to one cycle of each column 21 which is a spatial structure provided in the transfer section 3
However, as shown in the above formula (1), since it is an integral multiple of the half wavelength of the surface wave, that is, ½ times here, the surface wave is between the surface wave and each column 21. The surface wave is quickly attenuated. Therefore, the surface wave inevitably generated by instantaneously heating the transfer dye is almost completely suppressed, and the decrease in the transfer amount onto the photographic printing paper 14 is prevented.

It is desirable that the unit width d of the spatial structure is set to a value within an allowable range (0.8 to 1.2 times) centered on an integral multiple of the half wavelength of the surface wave. When the unit width d is a value exceeding the allowable range, the deviation between the wavelength λ of the surface wave and the unit width d cannot be ignored and the effect of attenuating the generated surface wave is significantly reduced.

When the image transfer amount was measured using the thermal transfer device according to the first embodiment, it was 80 μm per 1 ms.
The result was that the transfer dye corresponding to OD 2.2 was transferred onto the photographic printing paper 14 by the Macbeth densitometer in the area of × 80 μm. The transfer amount increased in proportion to the transfer time.

Here, some comparative examples for the above-mentioned measurement of the image transfer amount in the first embodiment will be shown. First, in the first comparative example, in the spatial structure of the transfer portion 3, the unit width d corresponding to one cycle is 3 μm, that is, the width of each pillar 21 and the interval between each pillar 21 are both 1. When the image transfer amount was measured under the same conditions as in the first embodiment except that the thickness was 5 μm, it was 80 μm per 1 ms.
Only a transfer dye corresponding to OD1.2 is transferred by the Macbeth densitometer to the area of m × 80 μm, and even if the transfer time is increased, the dot diameter on the photographic printing paper 14 is only expanded, and the dot OD changes. Not shown.

Next, as a second comparative example, the pulse period of the laser light of the semiconductor laser 1 is 20 μs, that is, the wavelength λ of the surface wave is 3.7 according to the equations (1) and (2).
The image transfer amount was measured under the same conditions as in the first embodiment except that the value was 80 μm per 1 ms.
Only a transfer dye corresponding to OD1.1 is transferred by the Macbeth densitometer to the area of μm × 80 μm, and even if the transfer time is increased, the dot diameter on the photographic printing paper 14 is only expanded, and the OD of the dot changes. Not shown.

Therefore, according to the thermal transfer recording apparatus of the first embodiment, the spatial structure of the transfer section 3 is approximately 2 as compared with the case where the spatial structure of the transfer section 3 is out of the regulation range shown in the equation (1). A double image transfer amount can be obtained, and a high-quality color image can be easily produced.

Next, the thermal transfer recording apparatus according to the second embodiment will be described. The same symbols are given to members and the like corresponding to the first embodiment. The second embodiment has substantially the same structure as the first embodiment, but is different in that the spatial structure of the transfer portion 3 is different.

That is, in the thermal transfer recording apparatus of the second embodiment, as shown in FIG. 5, the transfer portion 3 has a groove portion 3 on the lower surface portion in the dye containing portion 2 corresponding to the opening portion 2a.
1 is formed.

The groove portion 31 has a width d of 75 as a unit width.
The transfer dye is formed in a molten state and has a depth of 20 μm. Regarding the semiconductor laser 1 which is the heating means of the transfer dye, the pulse period of the laser light is set to 20 μs, that is, the wavelength λ of the surface wave is set to 3.7 μm from the above equations (1) and (2). .

In the thermal transfer recording apparatus according to the second embodiment, since the spatial structure having the unit width d represented by the above formula (1) is formed, the transfer dye melted by the laser semiconductor 1 is vaporized. The generation of surface waves is suppressed when the heat treatment is performed.

That is, the gap 13 is provided between the transfer dye layer 22 and the printing paper 14, and the transfer dye layer 22 and the printing paper 14 are provided.
When the transfer dye in a molten state is heated and vaporized by the laser semiconductor 1 without being brought into contact with and when the image is transferred from the transfer section 3 to the photographic paper 14 through the void section 13,
Since it is necessary to instantly raise the temperature of the transfer dye to vaporize it, a difference in surface tension between the heated portion and the non-heated portion of the transfer dye occurs and a surface wave is generated. However, the width d of the groove portion 31 which is the spatial structure provided in the transfer portion 3 is set to an integral multiple of the half wavelength of the surface wave, here, about 40 times, as shown in the equation (1). This surface wave and the groove 3
The action of canceling the surface wave works with 1 and the surface wave is rapidly attenuated. Therefore, the surface wave inevitably generated by instantaneously heating the transfer dye is almost completely suppressed, and the decrease in the transfer amount onto the photographic printing paper 14 is prevented.

When the image transfer amount was measured using the thermal transfer device according to the second embodiment, it was 80 μm per 1 ms.
As a result, the transfer dye corresponding to OD 2.0 was transferred onto the photographic printing paper 14 by the Macbeth densitometer in the region of 80 μm. The transfer amount increased in proportion to the transfer time.

Here, a comparative example (third comparative example) for the above-described measurement of the image transfer amount in the second embodiment will be shown. In the third comparative example, in the spatial structure of the transfer part 3, the width d of the groove part 31 which is a unit width is set to 65 μm which is not a half integer multiple of the wavelength λ of the surface wave, and the other parts of the second embodiment. When the image transfer amount was measured under the same conditions as above, only the transfer dye corresponding to OD1.4 was transferred by the Macbeth densitometer in the area of 80 μm × 80 μm per 1 ms, and even if the transfer time was increased, it was on the printing paper 14. The dot diameter was increased, and the dot OD showed no change.

Therefore, according to the thermal transfer recording apparatus in the second embodiment, it is about 2 as compared with the case where the spatial structure of the transfer section 3 is out of the regulation range shown in the equation (1). A little less than double the image transfer amount can be obtained, and a high quality color image can be easily produced.

The present invention is not limited to the first and second embodiments described above, and a thermal head may be used as a heating means for the transfer dye. Further, as the spatial structure of the transfer portion 3, not only the pillar 21 and the groove portion 31 but also the
For example, a hole or a concentric wall may be used to satisfy the above formula (1).

[0044]

According to the thermal transfer recording apparatus of the present invention,
In a thermal transfer recording apparatus in which a gap is provided between a transfer dye layer and a transfer recording medium, the transfer dye is melted and supplied to a transfer unit, and then this is vaporized by a heating means and transferred onto the transfer recording medium. , Ρ is the density of the transfer dye, γ is the surface tension of the transfer dye, and ω is the angular frequency of heating synchronization, the unit width d of the spatial structure of the transfer portion is 0. Since 8nπ (γ / ρω ² ) ^1/3 <d <1.2nπ (γ / ρω ² ) ^1/3 is configured, the transfer dye is appropriately vaporized according to the image signal and the transfer recording is performed on the printing paper. By doing so, it becomes possible to easily produce a high-quality color image.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing a main part of a thermal transfer recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a temporal change in output of laser light from a semiconductor laser.

FIG. 3 is a plan view schematically showing a spatial structure of a transfer portion of the thermal transfer recording device.

FIG. 4 is a sectional view schematically showing a spatial structure of a transfer portion of the thermal transfer recording device.

FIG. 5 is a sectional view schematically showing a main part of a thermal transfer recording apparatus according to a second embodiment of the invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser 2 Dye accommodation part 3 Transfer part 11 Lens 12 Spacer 13 Void part 14 Printing paper 21 Column 31 Groove part

Claims (3)

[Claims] 1. A gap is provided between the transfer dye layer and the recording medium to be transferred, and after the transfer dye is melted and supplied to the transfer portion,
In a thermal transfer recording apparatus in which this is vaporized by a heating means and transferred onto a recording medium to be transferred, when the density of transfer dye: ρ, the surface tension of transfer dye: γ, the angular frequency in synchronization with heating: ω, The unit width d of the spatial structure of is given by 0.8nπ (γ / ρω ² ) ^1/3 <d <1.2nπ (γ / ρω ² ) ^1/3 , where n is a positive integer. Thermal transfer recording device. 2. A thermal transfer recording apparatus according to claim 1, wherein a laser is used as a heating means for the transfer dye. 3. A thermal transfer recording apparatus according to claim 1, wherein a thermal head is used as a heating means for the transfer dye.