JPH0332860A - Thermal printer of sublimable thermal transfer type - Google Patents

Abstract

PURPOSE:To obtain a hard copy superior in glossiness and enhanced in image quality by a method wherein an image receiving layer provided on a printing paper surface for accepting a sublimable dye transferred due to a heating energy by a thermal head is heated and softened, and the softened printing paper surface is smoothened. CONSTITUTION:In printing, each heating resistor 20 applies a heating energy substantially in proportion to the conduction time therefor to an ink ribbon 10. In accordance with the heating energy, a sublimable dye on the ribbon is discretely sublimated to transfer onto a printing paper surface 16a opposed thereto. Printing paper 16 subjected to this transfer processing is moved on a mount 26 through guide rollers 24. An electric heater 28 as a heater part disposed above the mount 26 is applied with an electric power from a heating temperature control circuit 30 to generate heat, thereby heating and softening an image receiving layer on the printing paper surface 16a passing right below the heater 28. Thereafter, the printing paper 16 is passed through a high- smoothness roller 34. The roller 34, e.g. a glass roller, which is a rigid body with a periphery remarkably highly smoothened, smoothes the printing paper surface 16a which has been softened due to heating by the heater part of a prior step.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal printer that creates hard copies using a sublimation thermal transfer method.

[Prior Art] In a sublimation thermal transfer type thermal printer, a thermal head generates thermal energy according to an image signal, and the thermal energy sublimates ink (sublimable dye) on an ink sheet to print on photographic paper (recording Ml). Transfer to the top and record the image. With this method, halftone recording is easy and a density gradation method is possible.

[Problems to be Solved by the Invention] By the way, in a print image created by a conventional thermal printer of this type, a large number of minute irregularities are observed on the image receiving layer on the surface of photographic paper.

These irregularities are caused by uneven transfer, mechanical damage caused by photographic paper transport,
This is caused by physical scratches, deformation of the image receiving layer during recording, etc.
It causes the print to lose its luster, reduces color reproducibility in full-color prints, and lowers the image quality.

The present invention has been made in view of such problems, and an object of the present invention is to provide a thermal printer capable of producing sublimation thermal transfer hard copies with high gloss and high image quality.

[Means for Solving the Problems] In order to achieve the above object, the sublimation thermal transfer thermal printer of the present invention applies thermal energy according to image information to an ink ribbon coated with a sublimable dye, and a thermal head means for sublimating the sublimable dye and transferring it onto the photographic paper; a heater means for heating and softening the image receiving layer on the surface of the photographic paper that receives the transferred sublimable dye; and a photographic paper softened by heating. and high smoothness roller means for smoothing the surface.

Furthermore, in order to reduce the size of the apparatus, a configuration was adopted in which a heater means was built into the high smoothness roller.

Furthermore, in order to obtain high image quality by optimizing the heating softening of the image receiving layer on the surface of the photographic paper, the heater means is heated based on the temperature detection means disposed near the heater means and the output signal of the temperature detection means. The heating temperature control means controls the heater means to optimize the temperature.

[Operation] The sublimable dye is sublimated from the ink ribbon and transferred onto the photographic paper by the heat generated by the thermal head means. During this transfer, the adhesion of the dye may be insufficient and uneven transfer may occur. Furthermore, when the photographic paper passes through the guide rollers and heads, mechanical and physical scratches may occur on the surface of the photographic paper.

Such uneven transfer, scratches, etc. cause minute irregularities on the surface of the photographic paper.

According to the present invention, the heater means softens the image receiving layer by heating the image receiving layer on the surface of the photographic paper that receives the sublimable dye transferred by the printing process of the print head, and then the high smoothness roller means smoothes the surface of the photographic paper.

As a result, the unevenness on the surface of the photographic paper is eliminated, and the diffusion of the dye into the image-receiving layer is promoted, resulting in enhanced color development. This results in a glossy, high-quality hard copy.

In addition, by incorporating the heater means into the high smoothness roller, the roller and heater can be placed in one place.
The device can be designed compactly.

Furthermore, when a temperature detection means is arranged near the heater means, its output signal represents the heating temperature for the surface of the photographic paper.

The heating control means compares the output signal with a reference value, for example, and controls the ON@OFF operation of the heater means to set the heating temperature optimal for softening the image receiving layer.

[Embodiment] FIG. 1 shows the configuration of essential parts of a sublimation thermal transfer type thermal printer according to an embodiment of the present invention.

The ink ribbon 10 is coated with sublimable dye ink, and is passed from the supply reel 12 to the thermal head 1 during printing.
8 and is sent to the winding wheel 14. The photographic paper 16 is
A recording paper having an image-receiving layer on the surface lea that receives the sublimable dye transferred from the ink ribbon 10, which passes through the thermal head 18 as usual during printing, and then passes through the heater section and smooth section according to this embodiment. Ru.

The thermal head 18 includes a large number of heating resistive elements 20 in a direction (line direction) perpendicular to the plane of the drawing. During printing, each heating resistor element 20 is selectively energized and generates heat for a period of time corresponding to image information while being pressed against the platen 22. As a result, heat generation energy approximately proportional to the energization time is applied to the ink ribbon 10 from each heating resistance element 20, and the sublimable dye on the ribbon is discretely sublimated (vaporized) and opposed to each other in accordance with each heat generation energy. Transfer (transfer) onto the photographic paper surface lea. The photographic paper 1B that has undergone this transfer process passes through a guide roller 24 and moves on a table 26.

Above this table 26 is an electric heater 2 as a heater section.
8 are arranged. The electric heater 28 is comprised of a resistor that generates heat upon receiving electric power from the heating temperature control circuit 30, and heats and softens the image receiving layer on the surface 18a of the photographic paper that passes directly beneath it. In this embodiment, a thermistor 32 is provided near the heater 28, and its output signal (a signal representing the heating temperature of the heater 28) is given to a heating temperature control circuit 30. The control circuit 30 compares the signal with a reference value set according to the quality of the photographic paper, the material of the sublimable dye, etc.
0N10FF of the heating power supply for the heater 28 is controlled so that the heating temperature is optimal for heating and softening the photographic paper image-receiving layer.

Next, the photographic paper 16 is passed through a high smoothness roller 34.

This roller 34 is a rigid body, for example, a glass roller, and has an outer peripheral surface processed to an extremely high degree of smoothness, and smoothes the surface lea of the photographic paper, which has been softened by heating by the preceding heater section. The auxiliary roller 36 and the high smoothness roller 3
The photographic paper 16 is sandwiched between the rollers 4 and 4, and the smoothing by the high smoothness roller 34 is strengthened. Note that the high smoothness roller 34 is
By disposing the auxiliary roller 36 at a position opposite to the auxiliary roller 36, it is also possible to omit the auxiliary roller 36.

As a result of the heat softening by the heater 28 and the smoothing by the high smoothness roller 34 as described above, minute irregularities on the photographic paper surface 18a are flattened, and the diffusion of the sublimable dye into the image receiving layer is promoted to improve color development. This results in a high-quality, glossy hard copy.

FIG. 2 shows the main part of the modified example. In this example, an electric heater 28' is embedded inside a high smoothness roller 34' to heat, soften and smooth the photographic paper image-receiving layer at the same time. According to this, the distance between the guide roller 24 and the high smoothness roller 34'' can be shortened, and the stand 26 can be omitted, so that the present printer device can be configured compactly. A rotating brush or the like may be used for feeding, and a thermistor may be attached to the surface of the roller 34' that does not contact the photographic paper 18 to optimize the heating temperature as described above.

[Effects of the Invention] By having the above-described configuration, the present invention provides the following effects.

According to the sublimation thermal transfer type thermal printer of claim 1, the image receiving layer on the surface of the photographic paper that receives the transferred sublimable dye is heated and softened by the heat generated by the thermal head, and the surface of the photographic paper softened by the heating is heated. Smoothing eliminates unevenness on the surface of the photographic paper and promotes color development of the sublimation dye, making it possible to produce hard copies with excellent gloss and high image quality.

According to the sublimation thermal transfer type thermal printer of the second aspect, by incorporating the heater means in the high smoothness roller, the apparatus can be made compact.

According to the sublimation thermal transfer type thermal printer of claim 3, the heating temperature of the heater means is optimized by the temperature detection means and the heating temperature control temperature, so that it can be applied to photographic paper or sublimable dye of arbitrary specifications and properties. Optimal softening treatment can be performed even when

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of the main parts of a sublimation thermal transfer type thermal printer according to an embodiment of the present invention, and FIG. 2 is a perspective view showing the structure of the main parts of a modified example. 16... Photographic paper, lea... Photographic paper surface, 18... Thermal head, 28.28'... Electric heater, 30... Heating temperature control device, 32...・Thermistor, 34.34'...High smoothness roller.

Claims (3)

[Claims] (1) A thermal head means that applies thermal energy according to image information to an ink ribbon coated with a sublimable dye to discretely sublimate the sublimable dye and transfer it onto photographic paper, and the transferred sublimation Sublimation characterized by comprising: a heater means for heating and softening the image receiving layer on the surface of the photographic paper that receives a color dye; and a high smoothness roller means for smoothing the surface of the photographic paper softened by heating. Heat transfer thermal printer. (2) The thermal printer according to claim 1, wherein the heater means is built into the high smoothness roller. (3) a temperature detection means disposed near the heater means; and a heating temperature control means for controlling the heater means to optimize the heating temperature of the heater means based on the output signal of the temperature detection means. A thermal printer according to claim 1 or 2, characterized in that the thermal printer comprises: