JP2002067363A - Color printing method and color thermal printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable printing with low electric power consumption and at a high speed. SOLUTION: In a color printing method using a color thermal recording paper on which plural coloring layers with different colors having different thermal sensitivities are laid and fixed by being irradiated with light of different wavelengths to lose their coloring reactivities, the light with wavelength to lose the coloring reactivity is applied to a part where coloring is unnecessary of the coloring layers in sequence from the layer with high thermal sensitivity to that with low thermal sensitivity (SP1, SP4, SP7) and then the coloring layers are heated with heat quantity corresponding to respective thermal sensitivities (SP2, SP5, SP8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color printing method and a color thermal printer, and more particularly, to a color printing method and a color thermal printer for recording a full-color image on a color thermosensitive recording paper having a light fixing property.

[0002]

2. Description of the Related Art One of the direct thermal recording type color thermal printers is a full-color printing type printer called a thermoautochrome type (hereinafter abbreviated as "TA type"). A recording method of the conventional color thermal printer using the TA method will be described with reference to FIGS.

FIG. 5 is a longitudinal sectional side view showing the structure of a color thermal recording paper C1 used in the conventional color thermal printer (not shown), FIG. 6 is a characteristic diagram showing the color development characteristics of the color thermal recording paper C1, and FIG. 2 is a flowchart showing a recording process of a conventional color thermal printer. The outline of the recording method of the TA thermal color printer is based on the fact that the three primary colors of yellow, magenta, and cyan are colored with heat energy in different ranges, and the respective primary colors are sequentially colored, and at the same time, as necessary. By performing light fixing after each of the primary colors has been formed, a full-color image is finally recorded.

First, as shown in FIG. 5, on a color thermosensitive recording paper C1, a yellow coloring layer 2 having a light-fixing property to ultraviolet light having a wavelength of about 420 nm is provided on the outermost side, and an ultraviolet light having a wavelength of about 365 nm is provided on the inner side. A magenta coloring layer 3 having a light fixing property and a cyan coloring layer 4 having no light fixing property are further laminated so as to contact the base paper 5.

Next, steps of a recording method of the color thermal printer will be described with reference to flowcharts of FIGS. FIG. 6 shows the coloring characteristics of the color thermosensitive recording paper C1. In the figure, the horizontal axis represents the heat energy, and the vertical axis represents the color density. In the figure, a, b, and c indicate the respective color densities of yellow, magenta, and cyan. The state of thermal recording in this case will be described with reference to the flowchart of FIG.

The thermal head is pressed against the color thermosensitive recording paper C1 to thermally record a yellow image line by line on the yellow thermosensitive coloring layer having the highest thermal sensitivity (ST1). Thereafter, in order to prevent the yellow coloring layer 2 from being colored even when heated in this step or later, and to develop only the desired primary color, the thermosensitive recording paper 1 is sequentially arranged from the portion where the thermal recording is completed. The color recording function of the yellow coloring layer 2 is eliminated by irradiating the thermosensitive recording paper 1 with ultraviolet rays having a wavelength of about 420 nm and performing light fixing (ST2).

Next, thermal recording (ST3) and light fixing (ST4) are similarly performed on the magenta coloring layer 3, and thermal recording is performed on the cyan coloring layer 4 having the lowest thermal sensitivity (ST5). A color image can be obtained.
Note that light fixing is not required for the cyan coloring layer having the lowest thermal sensitivity. Also, the case where the number of the coloring layers is three has been described, but the same processing may be repeated for each of the layers even when the number of the coloring layers is four.

[0008]

By the way, the direct thermal recording type color thermal printer which has a plurality of coloring layers having different thermal sensitivities and which can control the coloring density of each coloring layer with the supplied thermal energy, has the following problem. In order to develop the color of the lowest layer, high heat energy is required, and there is a problem that power consumption increases because heating and cooling are repeated for thermal recording one line at a time. In addition, since the recording heat is accumulated in the thermal head, it is difficult to control the amount of heat applied. In addition, because of the high thermal energy, it is necessary to temporarily reduce the temperature of the resistor in order to control the density of the image and the heating for color development, which causes a heat loss and a long print processing time. There is.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a color thermal printer capable of performing high-speed printing with low power consumption.

[0010]

According to the first aspect of the present invention,
A color thermosensitive recording paper with a light-fixing property in which a plurality of coloring layers of different colors that are colored by heating and have different thermal sensitivities are laminated, and each of the coloring layers loses color-forming reactivity when irradiated with light in a different wavelength band. In a color printing method using
In order from the color forming layer having the highest heat sensitivity, for each color forming layer, light irradiation in a wavelength band in which color development reactivity is lost only to a portion of the color forming layer where color is not formed in advance is performed, and then the color forming layer is subjected to heat corresponding to the heat sensitivity. Heating is adopted.

Here, "high heat sensitivity" means that a small amount of heat is required for coloring. Accordingly, in this case, it is also shown that the color develops even at a low heating temperature.

In the above configuration, for example, when printing is performed on a color thermosensitive recording paper provided with a three-color coloring layer composed of a coloring layer having a high thermal sensitivity, a middle coloring layer, and a low coloring, the thermal sensitivity is as follows. Is applied to only a portion of the color-forming layer that does not cause color development to a color suitable for light fixing of the color-forming layer, and the amount of heat generated by the color-forming layer and the amount of heat that does not lead to coloration of the middle color-forming layer Heat with. As a result, only the portion of the coloring layer having a high thermal sensitivity to be colored develops color.

Similarly, light is irradiated to a portion of the coloring layer having a medium heat sensitivity which is not colored at a wavelength suitable for the light, and the heat is generated by the coloring layer. Heat with inaccessible heat. Further, similarly, light irradiation is performed on a portion of the coloring layer having low heat sensitivity that does not cause coloring at an appropriate wavelength, and the layer is heated with the amount of heat for coloring the coloring layer. As a result, each color-forming layer develops a color and a desired color print image is printed on the color thermosensitive recording paper.

As described above, since the light fixing is performed in advance on the areas where the coloring layers are not colored, it is not necessary to heat only the portions where the coloring is to be performed. A rapid heating method can be appropriately selected, such as heating by passing the heating means for simultaneously heating the entire area in the width direction of the paper (the direction orthogonal to the conveyance direction) by the conveyance urging means.

According to a second aspect of the present invention, at least a portion which has at least a color formed after heating is provided for each of the color forming layers other than the color forming layer having the lowest thermal sensitivity, having the same structure as the first aspect of the present invention. In addition, a configuration is adopted in which light irradiation is performed in a wavelength band in which the coloring reactivity of the coloring layer is lost.

By adding the above-mentioned steps, light fixing after coloring is performed on the colored portions of each coloring layer. The light fixing after the color development may be performed not only on the colored region but also on the entire surface of the recording paper. In addition, even for the coloring layer having the lowest thermal sensitivity, light irradiation in a wavelength band that causes the coloring reactivity of the coloring layer to be lost may be performed on a portion where the coloring is formed after heating.

According to a third aspect of the present invention, a plurality of coloring layers of different colors, each of which develops a color by heating and has a different thermal sensitivity, are stacked, and each of the coloring layers loses the coloring reactivity by light irradiation in a different wavelength band. In a color thermal printer that prints on a color thermal recording paper having a light fixing property, a transport urging means provided along a transport path on which the color thermal recording paper is transported, and a color thermal recording on the transport path A light irradiator that irradiates the paper with light in a wavelength band that causes the color-forming reactivity of each color-developing layer to be lost, and is inserted between the light irradiator and the color thermosensitive recording paper on the transport path, and receives external input. A pre-fixing unit that has a shielding unit that shields the irradiation light from the light irradiation unit with a mask pattern that can be changed based on information, and heats the color thermosensitive recording paper on the transport path with the amount of heat according to the thermal sensitivity of each color forming layer Heating It adopts a configuration that includes a and.

With the above configuration, the same steps as those of the color printing method according to the first aspect are performed.

For the shielding portion of the pre-fixing portion, for example, pattern information is input from the outside and a predetermined mask pattern is formed based on the pattern information.

The light irradiating section may be a single light irradiating section which can be adjusted to a wavelength suitable for light fixing of each color forming layer, or a plurality of light irradiating sections which individually emit light of each wavelength. It may be a light irradiation unit. In the case of a plurality of color recording layers, the color thermosensitive recording paper is conveyed to each light irradiating unit by the conveying urging unit at the time of light fixing of each color forming layer.

Similarly, the heating section may be a single heating section capable of adjusting the amount of heat suitable for the coloring of each coloring layer, or a plurality of heating sections for individually heating each coloring layer. Department. Even when there are a plurality of heating units, the color thermosensitive recording paper is conveyed to the respective heating units by the conveyance urging means when each of the coloring layers is heated.

When both the pre-fixing section and the heating section are single, the color thermosensitive recording paper is reciprocated between these sections by the conveying urging means according to the process.

According to a fourth aspect of the present invention, in addition to having the same configuration as the third aspect of the present invention, a mask control section for newly setting a mask pattern of the shielding section is provided. The unit is provided with a pre-fixing function of forming a mask pattern that blocks irradiation light to a color forming area of each color forming layer based on printing information on the color thermosensitive recording paper.

According to the fourth aspect of the present invention, the same operation as that of the third aspect of the present invention is performed, and when print information is input to the mask control unit from an external higher-level device, for example, The coloring pattern information of the color to be colored is extracted, and a mask pattern (a mask pattern having a shielding area having the same shape as the coloring pattern) for blocking the coloring pattern is formed by the shielding unit.

According to a fifth aspect of the present invention, in addition to the same configuration as the fourth aspect of the present invention, the mask control unit, after being heated by the heating unit, based on the printing information on the color thermosensitive recording paper, And a post-fixing function of forming a mask pattern that blocks irradiation light to a region other than the region where the color is to be formed.

According to the fifth aspect of the invention, the same operation as that of the fourth aspect of the invention is performed, and after the color of the color forming layer is formed, the color thermosensitive recording paper is returned to the pre-fixing section again by the conveying urging means. Light in a wavelength band that causes loss of color development reactivity is applied through a shielding portion in which a mask pattern that shields a portion other than the coloring portion is formed. Therefore, the color-developed portion is fixed by light irradiation. As described above, when the light fixing of the coloring portion is performed for each coloring layer, no reaction occurs in the coloring portion even when the coloring layer after the coloring layer is heated. This is because, for example, when the coloring of the coloring layer is suppressed to less than 100% or when the coloring is suppressed for the purpose of shading a part of the coloring portion, the coloring reaction is performed by heating the coloring layer that follows. Can be prevented from proceeding.

According to a sixth aspect of the present invention, in addition to having the same configuration as the third, fourth or fifth aspect of the present invention, the light irradiating section comprises a light irradiator of each wavelength band which causes the color forming layer to lose its color forming reactivity. , A plurality of light-emitting lamps emitting light.

According to the seventh aspect of the present invention, in the third or fourth aspect,
In addition to having the same configuration as the described invention, the transport biasing unit transports the color thermosensitive recording paper in a constant traveling direction along the transport path, and the pre-fixing unit and the heating unit individually corresponding to each color forming layer The heating unit is arranged downstream of the pre-fixing unit in the fixed traveling direction, and the pre-fixing unit and the heating unit are arranged in a predetermined order in order from the one corresponding to the color layer having high thermal sensitivity. The arrangement is such that they are arranged side by side from the upstream side to the downstream side in the direction.

In the above configuration, a pre-fixing section and a heating section are provided for each of the coloring layers individually, and these are arranged in order from the one corresponding to the coloring layer having high thermal sensitivity along the transport direction of the color thermosensitive recording paper. It is arranged in. Therefore, as the color thermosensitive recording paper is conveyed, the pre-fixing section and the heating and coloring are sequentially repeated from the coloring layer having the highest thermal sensitivity to the coloring layer having the lowest thermal sensitivity. As described above, since the color thermosensitive recording paper reaches the area where each process is performed by being conveyed in a certain traveling direction, the printing operation can be performed smoothly and quickly.

According to an eighth aspect of the present invention, there is provided the same configuration as that of the seventh aspect of the present invention, and at least each of the color forming layers other than the color forming layer having the lowest thermal sensitivity corresponds to each of the color forming layers. A post-fixing unit that irradiates the color-forming layer with light in a wavelength band that causes loss of color-forming reactivity is provided, and each of these post-fixing units is disposed adjacent to a downstream side in a certain traveling direction of a heating unit corresponding to the same color-forming layer. Has been adopted.

According to the eighth aspect of the present invention, the same operation as that of the seventh aspect of the present invention is performed, and after the color has been formed in each of the color forming layers, the post-fixing section performs light fixing on the color forming portion, and thereafter, The process proceeds to the next color forming layer.

Incidentally, after the color development of the last color development layer,
Since there is no subsequent heating in the printing process, there is no need to provide a post-fixing section. However, a post-fixing section may be provided for the last coloring layer in order to improve the image stability of the color thermosensitive recording paper after printing is completed.

According to the ninth aspect of the present invention,
In addition to having the same configuration as the invention described in 5, 6, 7, or 8, the liquid crystal shutter is used as the shielding unit.

According to the tenth aspect of the present invention, a plurality of coloring layers of different colors which are colored by heating and have different thermal sensitivities are laminated, and each coloring layer loses its coloring reactivity by light irradiation in a different wavelength band. In a color thermal printer that prints on a color thermosensitive recording paper having a light fixing property, a transport urging means provided along a transport path on which the color thermal recording paper is transported, and a color development reaction of each color forming layer A laser light source that emits laser light in a wavelength band that causes loss of light in a blinkable manner, and a laser light that scans laser light in a direction perpendicular to the direction of conveyance of color thermosensitive recording paper conveyed along the conveyance path The configuration includes a scanning unit and a heating unit that heats the color thermosensitive recording paper on the transport path with a heat amount corresponding to the thermal sensitivity of each coloring layer.

With the above configuration, the same steps as those of the color printing method according to the first aspect are performed. According to the above configuration,
Light irradiation for losing color development reactivity before color development is performed by scanning with laser light. At the time of scanning with laser light, the laser light source stops emitting light for a portion to be colored, and continuously emits light for other portions. As a result, only the non-irradiated portion of the laser beam is colored by heating.

According to an eleventh aspect of the present invention, in addition to having the same configuration as the tenth aspect of the present invention, a laser beam scanning control unit for controlling the blinking of the laser light source and the timing of scanning by the laser beam scanning unit is provided. The laser light scanning control unit has a configuration in which a function of performing control of irradiating laser light excluding a region where each color forming layer develops a color based on printing information on the color thermosensitive recording paper is adopted.

According to the eleventh aspect of the present invention, the same operation as that of the tenth aspect of the present invention is performed, and when print information is input to the laser light scanning control unit from an external host device, for example, The control unit takes out the coloring pattern information of the color to be developed, which is included in the print information, and determines the scanning timing and the flash timing of the laser light source so that the laser light does not hit the light emitting portion from the pattern information. Operation control for performing laser beam scanning is performed.

According to the twelfth aspect of the present invention,
A configuration similar to that of the invention described in 4, 5, 6, 7, 8, 9, 10, or 11 is provided, and the heating unit is formed of a heat roller.

The present invention aims at solving the above-mentioned problems by the above-mentioned respective structures.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A color thermal printer 1 according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a simplified configuration diagram of the color thermal printer 1, FIG. 2 is a block diagram showing a control configuration thereof, and FIG. 3 is a flowchart showing an image recording process by the color thermal printer 1.

The color thermal printer 1 is formed by stacking a plurality of color-forming layers of different colors, each of which develops a color by heating and has a different thermal sensitivity, and each of the color-forming layers loses color-forming reactivity when irradiated with light in a different wavelength band. Printing is performed on color thermosensitive recording paper C, which is cut paper having fixability. The color thermosensitive recording paper C has substantially the same structure and characteristics as the color thermosensitive recording paper C1 described above (see FIGS. 5 and 6), but the cyan coloring layer is formed by ultraviolet rays of a different wavelength band from the yellow and magenta coloring layers. It differs from the color thermosensitive recording paper C1 in that it has light fixing properties.

The color thermal printer 1 includes transport rollers 11, 12, and 13 as transport urging means provided along a transport path on which the color thermal recording paper C is transported, and color thermal recording paper C on the transport path. On the other hand, a light irradiator 40 that irradiates light in a wavelength band that causes the color-forming reactivity of each color-forming layer to be lost,
A shielding unit interposed between the light irradiating unit 40 and the color thermosensitive recording paper C on the conveyance path, and shielding the irradiation light from the light irradiating unit 40 with a mask pattern that can be changed based on externally input information. A pre-fixing section 42 having a liquid crystal shutter 6, a thermal head 10 as a heating section for heating the color thermosensitive recording paper C on the transport path with a heat amount corresponding to the thermal sensitivity of each color-forming layer, and controlling the operation of each of the above components. Operation control means 43 for performing the operation.

The pre-fixing section 42 includes a light irradiating section 40, a liquid crystal shutter 6, and a housing 44 which does not leak the irradiation light from the light irradiating section 40 to the outside from outside the liquid crystal shutter 6.

The light irradiating section 40 is composed of a plurality of ultraviolet lamps 7, 8, and 9 as a plurality of light emitting lamps for emitting light in each wavelength band that causes the color forming layer of the color thermosensitive recording paper C to lose the color forming reactivity. Have been. That is, reference numeral 7 denotes a yellow fixing ultraviolet lamp, reference numeral 8 denotes a magenta fixing ultraviolet lamp, and reference numeral 9 denotes a cyan fixing ultraviolet lamp.

The liquid crystal shutter 6 is a so-called transparent liquid crystal, and the liquid crystal surface is arranged so as to face the surface of the color thermosensitive recording paper C conveyed on the conveyance path. The liquid crystal shutter 6 has a liquid crystal surface having substantially the same size as a printing area for one sheet of the color thermosensitive recording paper C, and the liquid crystal surface is partitioned into an infinite number of dots that determine the printing resolution. The liquid crystal shutter 6 can be switched between a passable state and a blocked state of the irradiation light from the light irradiation unit 40 for each dot by a mask control unit 45 described later.

The thermal head 10 is composed of two heating plates disposed so as to sandwich the transport path from above and below. Each heating plate has a built-in heater and is set to a predetermined temperature by the operation control means 43. Further, each heating plate is set to a size that can just sandwich the entire surface of one color thermal recording paper C.
The upper heating plate can be moved up and down by an operation command from the operation control means 43, and when the color thermosensitive recording paper C is heated, it is lowered to sandwich the entire surface of the color thermosensitive recording paper C. .

The operation control means 43 receives a print command and print information from a higher-level device (not shown) and outputs a print operation command to each of the transport rollers 11, 12, and 13, the thermal head 10, and the pre-fixing section 42. .

Further, the operation control means 43 includes a mask control section 45 for controlling to freely set a mask pattern (a pattern formed by blocking some dots) of the liquid crystal shutter 6. I have. The mask control unit 45 includes a memory 47 for storing coloring pattern data for each color included in the printing information on the color thermosensitive recording paper. This coloring pattern data is data indicating whether or not a minute area on the recording paper surface corresponding to the dot stored for each dot of the liquid crystal shutter develops the color.

Further, the mask control section 45 has a pre-fixing function of forming a mask pattern for blocking irradiation light to a color forming area of each color forming layer based on each color forming pattern data, and It has a post-fixing function of forming a mask pattern that blocks irradiation light to areas other than the color forming areas of each color forming layer based on printing information on the color thermosensitive recording paper C.

The operation of the color thermal printer 1 having the above configuration will be described with reference to FIG.

When the operation control means 43 receives the print command and the print information from the host device, the mask control section 45 stores the color development pattern data of each color from the print information in the memory 47.
To memorize. The operation control means 43 drives the transport roller 11 to fix the color thermosensitive recording paper C to the pre-fixing section 42.
Feed paper. Further, the mask control unit 45 forms a mask pattern on the liquid crystal shutter 6 based on the pre-fixing function by referring to the yellow heat-sensitive pattern data having the highest thermal sensitivity and setting the dots to be colored in a shielding state. Then, ultraviolet rays are radiated from the yellow fixing ultraviolet lamp 7 through the mask pattern, and a portion where yellow is not formed is formed on the yellow coloring layer surface (ST1).

Then, the color thermosensitive recording paper C is sent between the heating plates of the thermal head 10 through the transport roller 12, and is sandwiched and heated to develop yellow (ST).
2).

Thereafter, the color thermosensitive recording paper 1 is returned under the liquid crystal shutter 6 through the transport rollers 12. The mask control unit 45 forms a mask pattern on the liquid crystal shutter 6 based on the post-fixing function by referring to the yellow color pattern data again and setting the non-colored dots in a shielding state. Then, ultraviolet rays are radiated from the yellow fixing ultraviolet lamp 7 through the mask pattern, and light fixing is performed on the portion that has already developed yellow (ST3).

Next, the mask control unit 45 forms a mask pattern on the liquid crystal shutter 6 based on the pre-fixing function by referring to the magenta color pattern data having the next highest thermal sensitivity and setting the dots to be colored in a shielding state. Then, ultraviolet rays are irradiated from the magenta fixing ultraviolet lamp 8 through the mask pattern, and a portion where magenta is not formed is formed on the magenta coloring layer surface (ST4).

Then, the color thermosensitive recording paper C is sent between the heating plates of the thermal head 10 through the conveying roller 12, and is sandwiched and heated at a temperature higher than that of the yellow color to develop magenta (ST5).

Thereafter, the color thermosensitive recording paper 1 is returned under the liquid crystal shutter 6 through the transport rollers 12. The mask control unit 45 forms a mask pattern on the liquid crystal shutter 6 based on the post-fixing function by referring again to the magenta coloring pattern data and setting the non-coloring dots in a shielding state. Then, ultraviolet rays are irradiated from the magenta fixing ultraviolet lamp 8 through the mask pattern, and light fixing is performed on a portion where magenta has already been colored (ST6).

Next, the mask control unit 45 forms a mask pattern on the liquid crystal shutter 6 based on the pre-fixing function by referring to the cyan color pattern data having the lowest thermal sensitivity and setting the dots to be colored in a shielding state. Then, ultraviolet rays are radiated from the cyan fixing ultraviolet lamp 9 through the mask pattern, and a portion where cyan is not formed is formed on the cyan coloring layer surface (ST7).

Then, the color thermosensitive recording paper C is sent between the heating plates of the thermal head 10 through the transport roller 12, and is sandwiched between the heating plates at a temperature higher than that of magenta, and heated to develop cyan (ST8).

Thereafter, the color thermosensitive recording paper 1 is returned under the liquid crystal shutter 6 through the transport rollers 12. The mask control unit 45 forms a mask pattern on the liquid crystal shutter 6 based on the post-fixing function by referring again to the cyan color pattern data and setting the non-colored dots in a shielding state. Then, ultraviolet rays are radiated from the cyan fixing ultraviolet lamp 9 through the mask pattern, and light fixing is performed on a portion where cyan has already been developed (ST9).

Through the above steps, a color image can be finally obtained. Finally, the thermal recording paper C is transported by the transport roller 13.
The paper is discharged through

Here, each of the above-mentioned pre-fixing steps (ST
In 1, 4, 7), the liquid crystal shutter is opened and closed halfway,
The function of adjusting the color density may be added to the mask control unit 45 by changing the degree of fixing. In this case, color tone data for each dot is extracted from the print information and stored in the memory 47, and a timer for measuring the time elapsed since the ultraviolet lamp was turned on is newly added, so that the color tone for each dot is adjusted. Control is performed to switch from the passable state to the shielded state (or vice versa) with a corresponding elapsed time.

It is desirable to carry out the step ST9 in consideration of the long-term stability of the color of the color thermosensitive recording paper C after printing. However, in the printing step, the color thermosensitive recording paper C after cyan coloring is used. Since there is no heating step, it can be omitted.

In the above embodiment, the light fixing process (ST3, 6, 9) is performed on all the color forming layers. However, the unfixed portions are completely colored (the density adjustment is not performed). If no change is caused by the heat energy, the light fixing step may be omitted.

In the color thermal printer 1, the latent image (pre-fixing), the development (heating) and the post-light fixing are performed as described above. Can be heated at the same time,
It is not necessary to provide a cooling period every time a line shifts as in the related art, and high-speed printing can be performed. Further, since it is not necessary to repeat heating and cooling for each line and the head can be kept at a constant temperature, power consumption can be reduced.

(Second Embodiment) FIG. 4 shows a color thermal printer 1A configured to enable continuous printing. The same components as those of the above-described color thermal printer 1 are denoted by the same reference numerals, and redundant description will be omitted.

In the color thermal printer 1A, the feed roller 14 for feeding out the continuous color thermal recording paper C2 and the color thermal recording paper C2 as a transport urging means are moved in a predetermined traveling direction along the transport path (the left side in FIG. 4). And a take-up roller 48 for conveying in a direction from the right to the right).

The pre-fixing sections 49, 50, 51 and the post-fixing sections 52, 53, 54 individually corresponding to the respective color forming layers.
And heating rollers 15, 16, and 17 as heating units. These are arranged in a concentrated manner for each corresponding color forming layer, and the conveying urging means are arranged in a certain traveling direction for conveying the color thermosensitive recording paper C2 in order from the one having the highest thermal sensitivity of the color forming layer. ing. That is, the pre-fixing section 49, the heating roller 15, and the post-fixing section 5 corresponding to the yellow coloring layer from the upstream side to the downstream side in a certain traveling direction.
2, a pre-fixing section 50 corresponding to the magenta coloring layer, a heating roller 16, a post-fixing section 53, a pre-fixing section 51 corresponding to the cyan coloring layer, a heating roller 17, and a post-fixing section 54 are arranged side by side.

Each of the fixing units 49, 50, 51, 52, 53,
54 is the same liquid crystal shutter 1 as the pre-fixing section 42 described above.
8, 19, 20, 24, 25, 26 and the same housing as the pre-fixing section 42.
In contrast, only the single ultraviolet lamps 21, 22, 23, 27, 28, 29 are provided, each of which fixes the corresponding color forming layer by light.

Each of the heat rollers 15, 16, and 17 has an outer peripheral surface that uniformly generates heat, and the amount of heat generated is set uniformly. However, the heat roller 15 for forming the yellow coloring layer has a small contact area with the color thermosensitive recording paper C2, and the heat roller 16 for forming the magenta coloring layer has a slightly large contact area with the color thermosensitive recording paper C2. The contact area of the heat roller 17 for forming the cyan coloring layer with the color thermosensitive recording paper C2 is set to be the largest. This causes a difference in the amount of heat applied to the color thermosensitive recording paper C2 between the heating rollers 15, 16, and 17 so that each of the heating rollers 15, 16 and 17 develops only the corresponding coloring layer.

Further, the color thermal printer 1A
Also has an operation control unit (not shown) similar to the color thermal printer 1. However, in the mask control unit provided in the operation control means of the color thermal printer 1A,
The pre-fixing function controls the self-fixing sections 49, 50, 51, respectively, and the post-fixing function controls the post-fixing sections 52, 53, 5, respectively.
4 is controlled.

With this configuration, the heat-sensitive recording paper C2 is irradiated with ultraviolet rays from the latent image ultraviolet lamps 21 to 23 through the liquid crystal shutters 18 to 20 for each color, and after the latent image, the heat is fixed using the heat rollers 15 to 17 at a fixed temperature. Heat developed. Thereafter, the fixing ultraviolet lamps 27 to 26 are passed through liquid crystal shutters 24 to 26 whose opening and closing settings are reversed from those of the liquid crystal shutters 18 to 20.
Ultraviolet rays are irradiated from 29 to eliminate the coloring function. In this case as well, as in the embodiment shown in FIG. 2, the unfixed portion is completely colored, and the light fixing process is unnecessary if the portion is not changed by the heat energy any more.

The heat-sensitive recording paper 14 comprises heat rollers 15 to 17
The color is developed only while contacting the
17 and the contact area between the heat-sensitive recording paper 14 and the heat rollers 15 to 17 can be easily adjusted, so that the color development time of each color can be easily adjusted. Is possible.

In the first and second embodiments, the example in which the liquid fixing is performed by the liquid crystal shutter in the page unit has been described. However, the present invention is not limited to this, and the line unit in the direction perpendicular to the transport direction is not limited to this. May be used for light fixing.

(Third Embodiment) In each of the above embodiments, the latent image is formed by irradiating ultraviolet rays through a liquid crystal shutter as a means for forming a latent image. Fixing can be performed. That is, in place of the pre-fixing section 42 shown in FIG. 4, a laser light source that emits a laser beam in a wavelength band that causes the color-forming reactivity of each color-forming layer to blink, and a color thermosensitive recording conveyed along a conveying path. A laser light scanning unit is provided which is capable of scanning the paper C with laser light in a direction perpendicular to the transport direction. A laser light scanning control unit for controlling the blinking of the laser light source and the timing of scanning by the laser light scanning unit is provided in place of the mask control unit 45, and the laser light scanning control unit prints information on the color thermosensitive recording paper C. A similar result can be obtained by adding a function of performing control of irradiating a laser beam except for a region of each color forming layer where a color is formed based on the above.

[0075]

As described above, in the present invention, for each color, color fixing is performed in advance, excluding the area where the color is formed on the color thermosensitive recording paper, and then, only the unfixed area is developed by heating to perform color printing. It is possible.

Thus, according to the present invention, since the entire paper can be heated simultaneously, heating and cooling in units of minute dots are not repeatedly performed as in the conventional thermal head, so that the cooling time is reduced. High-speed printing can be performed by eliminating printing delay. Further, since it is not necessary to repeat heating and cooling for each line and the head can be kept at a constant temperature, power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a simplified configuration diagram of a color thermal printer according to a first embodiment.

FIG. 2 is a control block diagram of the color thermal printer.

FIG. 3 is a flowchart showing an image recording process by the color thermal printer.

FIG. 4 is a simplified configuration diagram of a color thermal printer according to a second embodiment.

FIG. 5 is a vertical sectional side view showing a structure of a thermal recording paper.

FIG. 6 is a characteristic diagram showing color development characteristics of a thermosensitive recording paper.

FIG. 7 is a flowchart showing a recording process of a conventional color thermal printer.

[Explanation of symbols]

1,1A color thermal printer 2 yellow coloring layer 3 magenta coloring layer 4 cyan coloring layer 6,18,19,20,24,25,26 liquid crystal shutter (shielding part) 7,8,9 ultraviolet lamp 21,22,23, 27, 28, 29 UV lamp (light irradiating unit) 10 Thermal head (heating unit) 11, 12, 13 Conveying roller (conveying urging means) 15, 16, 17 Heat roller (heating unit) 40 Light irradiating unit 45 Mask control Part C, C2 Color thermal recording paper

Claims (12)

[Claims] 1. A plurality of coloring layers of different colors which are colored by heating and have different thermal sensitivities are laminated, and each of the coloring layers has a light fixing property of losing a coloring reactivity when irradiated with light in a different wavelength band. In the color printing method using the provided color thermosensitive recording paper, in order from the coloring layer having the highest thermal sensitivity, for each coloring layer, light irradiation in a wavelength band in which the coloring reactivity is lost only to a portion of the coloring layer in which coloring is not performed in advance is performed. And subsequently heating the color-forming layer with a heat amount corresponding to the thermal sensitivity. 2. At least for each of the coloring layers other than the coloring layer having the lowest thermal sensitivity, light irradiation in a wavelength band that causes the coloring reactivity of the coloring layer to be lost is applied to at least a portion where the coloring is performed after the heating. 2. The method according to claim 1, wherein
The described color printing method. 3. A plurality of coloring layers of different colors which are colored by heating and have different thermal sensitivities are laminated, and each of the coloring layers has a light fixing property of losing a coloring reactivity when irradiated with light in a different wavelength band. A color thermal printer that performs printing on a color thermal recording paper provided with: a transport urging unit provided along a transport path on which the color thermal recording paper is transported; On the other hand, a light irradiating unit for irradiating light in a wavelength band that causes the color-forming reactivity of each of the color-forming layers to be lost, and a light-sensitive recording paper interposed between the light irradiating unit and the color thermosensitive recording paper on the transport path, and input from the outside A pre-fixing unit having a shielding unit that shields irradiation light from the light irradiation unit with a mask pattern that can be changed based on information; and a color thermosensitive recording paper on the conveyance path according to the heat sensitivity of each of the coloring layers. heat A color thermal printer, comprising: a heating unit for heating by a quantity. 4. A mask control section for performing control for freely setting a mask pattern of the shielding section, wherein the mask control section causes each of the coloring layers to develop a color based on printing information on the color thermosensitive recording paper. The color thermal printer according to claim 3, further comprising a pre-fixing function of forming a mask pattern that blocks the irradiation light to an area. 5. The mask control section, after heating by the heating section, forms a mask pattern for blocking the irradiation light to areas other than the areas where the coloring layers of the respective coloring layers are to be colored based on printing information on the color thermosensitive recording paper. 5. The color thermal printer according to claim 4, further comprising a post-fixing function. 6. The light irradiating section comprises a plurality of light-emitting lamps that emit light in each wavelength band that causes the color-forming reactivity of each of the color-forming layers to be lost.
The described color thermal printer. 7. The transport urging unit transports the color thermosensitive recording paper in a fixed traveling direction along the transport path, and the pre-fixing unit and the heating unit individually corresponding to each of the color forming layers. The heating unit is arranged downstream of the pre-fixing unit in the predetermined traveling direction, and the pre-fixing unit and the heating unit are arranged in order from the one corresponding to the color layer having high thermal sensitivity. 5. The color thermal printer according to claim 3, wherein the color thermal printer is arranged side by side from the upstream side to the downstream side in the predetermined traveling direction. 8. A post-fixing unit for individually irradiating the color-developing layer after color development with light in a wavelength band that causes loss of color-developing reactivity, corresponding to each of the color-forming layers other than the color-forming layer having the lowest thermal sensitivity. 8. The color thermal printer according to claim 7, wherein each of the post-fixing sections is disposed adjacent to a downstream side of the heating section corresponding to the same color forming layer in the predetermined traveling direction. 9. The color thermal printer according to claim 3, wherein said shielding portion is a liquid crystal shutter. 10. A plurality of coloring layers of different colors which are colored by heating and have different thermal sensitivities are laminated, and each of said coloring layers has a light fixing property that loses coloring reactivity when irradiated with light in different wavelength bands. A color thermal printer for performing printing on a color thermosensitive recording paper provided with: a conveyance biasing means provided along a conveyance path through which the color thermosensitive recording paper is conveyed; A laser light source that emits laser light in a wavelength band to be blinked in a blinking manner, and a laser light that can scan the laser light in a direction perpendicular to the conveying direction on the color thermosensitive recording paper conveyed along the conveyance path. A color thermal printer, comprising: a scanning unit; and a heating unit that heats the color thermosensitive recording paper on the transport path with a heat amount corresponding to the thermal sensitivity of each of the coloring layers. 11. A laser light scanning control section for controlling timing of blinking of the laser light source and scanning by the laser light scanning section, wherein the laser light scanning control section is based on printing information on the color thermosensitive recording paper. 11. The color thermal printer according to claim 10, further comprising a function of performing control to irradiate the laser light except for a region of each of the color forming layers where the color is formed. 12. The apparatus according to claim 3, wherein said heating section comprises a heat roller.
A color thermal printer according to 10 or 11.