JPH07246722A - Melting type thermal transfer device - Google Patents

Abstract

(57) [Summary] [Object] To provide a fusion type thermal transfer device capable of obtaining a glossy image. A thermal printer comprises a platen 5, a thermal transfer print head 6, a supply core 8 holding an unused ink ribbon 7 on the upstream side of these, and a used ink ribbon 7 on the lower side of the downstream side.
A paper feeding roller 10, a pressing roller 11 are provided on the upper side of the downstream side, and a heat roller 1 is further provided on the downstream side.
2. The press roller 13 is provided. The heat roller 12 is covered with a metal having good thermal conductivity, has a smooth surface, and is provided with a heat source inside. The three primary colors Y, M, C and black Bk are arranged on the ink ribbon 7 in a frame sequential manner. The print head 6 moves up and down for each color printing, the ink ribbon 7 is wound up, and the paper P
Goes on and off, and the four colors are painted over. After the printing of the fourth color Bk is completed, the paper P is sandwiched by the heat roller 12 and the press roller 13 and is discharged from the discharge port 14 while being heated and pressed. As a result, the ink surface in the color-applied stepped portion is smoothed to reduce irregular reflection of light, and a glossy printed image is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fusion type thermal transfer device used as a print output device for word processors, computers and the like.

[0002]

2. Description of the Related Art Conventionally, in a fusion type thermal transfer device mounted on a thermal printer, a print head is provided with a heating element corresponding to the maximum number of pixels to be printed at once in the main scanning direction or the sub scanning direction. By selectively heating these heating elements corresponding to each pixel, the ink of the melted ink ribbon is transferred to a sheet to print an image. The gradation expression of print dots in the melting type thermal transfer device is an area gradation method (1 dot gradation method) in which the size of one dot is changed to obtain a gradation like a halftone dot in offset printing etc. The gradation expression is different from that of the density gradation method using the type ink ribbon. In printing, the ink of the ink ribbon is transferred to the paper surface by the thermal energy radiated by the heating element in a state where the heating element, the ink ribbon, the paper, and the platen are brought into contact in this order in the printing section.

The ink ribbon used for such printing has a long strip shape having a width substantially the same as one printing width of the print head. Usually, a base film made of PET (polyethylene terephthalate) and this base are used. It consists of ink applied uniformly on the film.

In the case of multicolor printing (color printing), the subtractive color mixture of Y (yellow: yellow) and M (magenta:
Red primary dye), C (cyan: blue with green), or Bk (black: dedicated to characters other than images)
An ink ribbon having a shape in which four colors of ink added with (black) are sequentially arranged in the longitudinal direction of the ink ribbon and repeatedly applied on the base film is used. Then, these colors are mixed in various proportions by overcoating to express various shades and gradations.

[0005]

By the way, in the case of coating the heat-melting type ink on the paper in many layers as described above,
For example, as shown in FIG. 7A, when the first-color layer 1 and the second-color layer 2 overlap, a step 3 is formed at the boundary between the overlapping portions. The step 3 scatters the reflected light and loses the gloss of the image. For example, the gloss like the image in the case of the transfer method using a sublimation ink or the silver salt method (normal photo) is generated. There was a problem that I could not get it.

The object of the present invention is to solve the above-mentioned conventional problems.
It is an object of the present invention to provide a fusion type thermal transfer device capable of obtaining a printed image having gloss.

[0007]

The structure of the fusion type thermal transfer device according to the present invention will be described below. According to a first aspect of the present invention, a heating head having a plurality of heating elements in a main scanning direction and a platen are arranged to face each other, and an ink ribbon on which inks of a plurality of colors are repeatedly provided in a sub scanning direction and a sheet are overlapped with each other. It is applied to a fusion type thermal transfer device that conveys the ink on an ink ribbon to a paper by forming a dot image by conveying the ink to a heating element by supplying electricity to a heating element.

According to a second aspect of the present invention, a heating head having a plurality of heating elements is slidably arranged so as to face a platen, and an ink ribbon on which inks of a plurality of colors are repeatedly provided and a sheet are superposed on each other. The present invention is applied to a fusion-type thermal transfer device which is located at a portion opposite to a platen and which energizes a heating element to transfer the ink on an ink ribbon onto a sheet to form a dot image.

Each of the melting type thermal transfer devices of the first and second inventions has a smoothing means for smoothing the surface of the ink transferred onto the paper. The smoothing means is a member that pressurizes and heats the ink surface, for example, as described in claim 3. Further, for example, as described in claim 4, the smoothing member, which is a separate member from the pressing and heating member, presses and heats the ink surface and heats it. And this smoothing means
For example, as described in claim 5, a smoothing member provided on the ink ribbon is pressed against the ink surface and heated by the heating head. Further, for example, claim 6
As described above, the ribbon-shaped smoothing member presses and heats the surface of the ink to press and heat it.

[0010]

According to the present invention, the smoothing means further pressurizes and heats the surfaces of the inks of a plurality of colors, which have been transferred by superimposing on the paper.

As a result, for example, the step in the overlapping portion of the two colors shown in FIG. 7 (a) is smoothed as shown in FIG. 7 (b), and the finished image becomes glossy.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of the configuration of the thermal printer according to the first embodiment as viewed from the side.

As shown in FIG. 1, a thermal printer (hereinafter referred to as a main body device) is provided with a platen roller 5 in the center of the inside of the device and a thermal head 6 below the platen roller 5 and facing the platen roller 5.

The platen roller 5 is a roller having a length substantially the same as the width of the paper used in the main body device, and is arranged so as to extend in the direction perpendicular to the paper surface of the figure, and the main body device is driven (not shown). It is driven to rotate counterclockwise by the device.

The thermal head 6 is also a thermal transfer print head having a width substantially the same as the width of the paper, has the same number of heating elements as the maximum number of print dots in the main scanning direction (width direction of the paper), and moves vertically. It is freely arranged and is apart from the platen roller 5 at the time of non-printing, and is moved downward at the time of printing to press the ink ribbon 7 and the paper P against the platen roller 5 to form a printing portion together with the platen roller 5. To do.

The ink ribbon 7 will be described in detail later,
This is also an ink ribbon formed in a long strip shape having a width substantially the same as the width of the paper P. A supply core 8 is arranged on the upstream side of the printing section. The supply core 8 winds and holds an unused ink ribbon 7 and supplies it to the printing unit. On the other hand, a winding core 9 is arranged below the downstream side of the printing section. The winding core 9 winds up the ink ribbon 7 that has been used for printing.

Further, a paper feed roller 10 and a pressing roller 11 which is in pressure contact with the upper surface of the paper feed roller 10 and is rotated by the paper feed roller 10 are disposed above the printing unit. . The paper feed roller 10 rotates in a clockwise direction when the printed paper P is conveyed (hereinafter, referred to as forward rotation), and rotates in a counterclockwise direction when returning the paper for overcoating in full color printing. (Hereafter referred to as reverse rotation).

These paper feed roller 10 and press roller 11
On the further downstream side of the heat roller 12, a heat roller 12 that rotates in a clockwise direction and a press roller 1 that is pressed against the upper surface of the heat roller 12 and is driven.
3 and the sheet discharge port 14 is provided immediately downstream of them.
Is provided. The surface of the heat roller 12 is coated with a metal having a good thermal conductivity such as copper, and the surface is finished to be smooth. A heat source (not shown) is arranged inside the roller. This heat roller 12
It is desirable that the surface of is coated with Teflon (trade name) or the like. Then, peeling from the ink surface described later can be performed more easily. The heat roller 12 radiates heat energy from the surface to smooth the print sheet P to be described later while discharging the printed sheet P from the discharge port 1.
Discharge from 4 to outside the main unit. The press roller 13 uses a relatively hard member having heat resistance. Also, unlike a usual paper discharge roller divided into a plurality of parts, it is a roller having the same length as the heat roller 12 and a diameter substantially the same as that of the heat roller 12. As a result, the larger diameter
The area of the pressing portion that performs the above smoothing is larger than that of the case where the diameter is small, and therefore, for the same conveyance speed of the paper P, heating and pressing are performed on the paper P for a longer time than when the diameter is small. It can be carried out.

FIG. 2 shows the structure of the ink ribbon 7. As described above, the ink ribbon 7 is formed in a long strip shape having a width substantially the same as the width of the paper P, and a base film made of a PET film having a thickness of, for example, about 4 to 6 μm, and a surface of the base film. Made up of ink applied to. The inks are repeatedly arranged in the vertical direction of the ink ribbon 7 in the order of the three primary colors Y, M, C, and black Bk dedicated to characters and the like. In the figure, for convenience of explanation,
Although each ink surface is illustrated as being horizontally long in the width direction of the ribbon, each ink surface is formed slightly larger than the area of one sheet of paper used, and is usually longer than the length of the paper. It is vertically long and has a length corresponding to the length. The color arrangement of the ink applied to the surface of the base film is not limited to the order of Y, M, C, and Bk described above, and the order of arrangement may be appropriate.

Next, the operation of the main part of the first embodiment having the above structure will be described again with reference to FIG. First, the paper P is automatically taken out from a paper storage unit (not shown) of the main body apparatus by a paper feed roller or the like, and is also conveyed from the left side to the right direction shown by an arrow A in the figure by a conveyance roller (not shown). This allows
The sheet P overlaps the ink ribbon 7 and is carried into the printing unit together.

The thermal head 6 ascends at the timing of the first printing, and presses the paper P and the ink ribbon 7 against the lower surface of the platen roller 5. The take-up core 9 is slidingly frictionally rotated at a speed faster than the conveyance speed of the paper P via the sliding friction clutch, and the ink ribbon having a length corresponding to the movement of the paper P as the paper P is moved. 7 is pulled from the supply core 8.

The control unit (not shown) selectively drives the heating element of the thermal head 6 to generate heat in accordance with print data via a driver (not shown). As a result, heat energy generated by the heating element is transferred from the back surface of the ink ribbon 7 to the ink, and the ink in this portion is melted and transferred onto the paper P (to the lower surface of the paper in the figure).

Subsequently, the winding core 9 rotates, the paper feed roller 10 rotates forward, and the pressing roller 11 follows. As a result, the paper P is fed, and the unused portion of the ink ribbon 7 is pulled out and supplied to the printing portion along with this feeding, and the used ink ribbon 7 is also wound up with it. Then, the paper P is once sent out from the printing unit while the ink of the ink ribbon 7 is being transferred, and first, the printing (transfer) of the color Y of the three primary colors is completed.

Next, the thermal head 6 descends to release the pressure contact of the printing section. Then, the paper feed roller 10 rotates in the reverse direction to pull the paper P back to the print start position. Further, the winding core 9 rotates to position the color M arranged next to the color Y. Then, the thermal head 6 moves up again to press the paper P and the ink ribbon 7 against the lower surface of the platen roller 5.

Then, the color M is printed in exactly the same manner as the case of the color Y printing described above. This is similarly performed for the third color C, and when printing with the fourth color Bk is completed, the paper P is directly conveyed in the forward transport direction (downstream).

The above-mentioned two-color coating state diagram shown in FIG. 7A shows an example of the transfer state of the ink immediately after being discharged from the printing section. Overpainting of colors as shown in FIG. 3 (a) occurs up to two colors, three colors, or four colors.

In this state, the leading edge of the sheet P is nipped by the heat roller 12 and the press roller 13 which is in pressure contact with the heat roller 12. The surface of the heat roller 12 is heated by an internal heat source.
It is heated to a temperature higher than the melting point of the ink transferred to the paper P, and the heat roller 12 heats and presses the ink transfer surface of the paper P while rotating in the clockwise direction. As a result, for example, the ink in the two-color coating stepped portion shown in FIG. 7 (a) is once melted, and a uniform ink surface with no step is formed by pressing, and smoothed as shown in FIG. 7 (b). It is re-solidified. This is the same in the case of three-color or four-color coating overlapping steps.

In this way, the printed paper P is discharged from the discharge port 14 to the outside. As shown in Fig. 7 (b),
By smoothing the ink surface, the irradiation light from the light source for the finished image is rarely irregularly reflected as in the case of the state of FIG. 7 (a), and the reflection direction becomes uniform and regular. Gives a glossy printed image.

In the first embodiment described above, the heat roller 12 is used to smooth the ink transferred to the paper P after the multicolor printing, but in this way, another heat source is purposely used. The same smoothing can be performed without using the heat source of the thermal head 6. This will be described below as a second embodiment.

FIG. 3 is a schematic cross-sectional view of the structure of the thermal printer according to the second embodiment, viewed from the side. In the figure, the same components as those of the first embodiment shown in FIG. 1 are indicated by the same numbers as those given to the configuration of FIG.

In the second embodiment, a discharge roller 15 is provided instead of the heat roller 12 shown in FIG. 1, and a discharge roller 16 having a small diameter and driven by the discharge roller 15 is disposed oppositely. The paper discharge roller 15 has no heat source, and its surface is not subjected to a treatment such as coating with a special metal having an attribute such as thermal conductivity. In other words, it is a very usual paper discharge roller made of synthetic resin having elasticity. The paper discharge roller 16 is the paper discharge roller 15
It is not necessary to form the rollers in the same length as the above, and a roller having a shape divided into a plurality of pieces that come into pressure contact with the upper surface of the paper discharge roller 15 may be used. Other configurations are similar to those shown in FIG.
However, the configuration of the ink ribbon 7'is slightly different.

FIG. 4 shows the structure of the ink ribbon 7 '. In the case of this ink ribbon 7 ', the three primary colors Y, M,
Ink is applied to the surface of the base film in the order of C and black Bk dedicated to characters and the like. Further, in this case, a metal foil having a good thermal conductivity and a smooth surface, for example, a copper foil Cu, is further attached and arranged next to the above four colors. Other configurations are similar to those of the ink ribbon 7 shown in FIG.

Next, the operation of the main part of the second embodiment having the above configuration will be described again with reference to FIG. First, up to the point where the paper P is automatically taken out from a paper storage (not shown) of the main body apparatus by a paper feed roller or the like and is printed in the order of colors Y, M, C, and Bk, it is completely the same as in the first embodiment. It is the same operation.

Next, in the second embodiment, when the printing of the black Bk of the fourth color is completed, the thermal head 6 descends to release the pressure contact of the printing portion, and then the paper feed roller 1
0 reversely rotates and pulls the paper P back to the print start position. Further, the winding core 9 rotates to position the copper foil Cu arranged on the ink ribbon 7'after the black Bk.
Then, the thermal head 6 moves up to press the paper P and the ink ribbon 7 against the lower surface of the platen roller 5.

The winding core 9 rotates to pull out the ink ribbon 7'from the supply core 8 and move the copper foil Cu together with the paper P in a state of abutting the transfer ink surface on the paper P. The control unit heats and drives all the heating elements of the thermal head 6 via the driver. As a result, the thermal energy generated by the heat generated by the heating element is quickly transferred to the transferred ink surface on the paper P, particularly the step portion of the overcoating that strongly abuts, through the base film of the ink ribbon 7'and the copper foil Cu (Fig. 7
(See (a)). As a result, the ink is melted around the step portion, pressed against the surface of the smooth copper foil Cu to be smoothed, and then solidified again.

Subsequently, the winding core 9 rotates, the paper feed roller 10 rotates forward, and the pressing roller 11 follows. Paper P
Is sent, and a new copper foil Cu portion is pulled out and supplied to the printing unit, and the used copper foil Cu portion is wound up. The paper P is sent out from the printing section while the surface of the transferred ink is smoothed, and further discharged from the discharge port 14 to the outside by the discharge roller 15 and the discharge roller 16. Also in this case, as shown in FIG. 7B, a glossy print image can be obtained by smoothing the ink surface.

By the way, in both the first and second embodiments, after smoothing the transfer ink, the smoothing member (heat roller 12 or copper foil Cu) is immediately separated from the ink surface which has not been sufficiently re-solidified. There is. Therefore, a small amount of ink is transferred from the ink surface to the smoothing member. Therefore, even though smoothed, the surface is coagulated in a coarse state when viewed microscopically. In other words, it is not a perfect smoothing, and therefore a satisfactory gloss cannot be obtained.

Next, a third embodiment for realizing a completely smoothed ink surface will be described. In this embodiment, the ink is solidified while the ink surface is in contact with the smooth metal surface. Then, the metal surface is peeled off when the ink is completely solidified. This gives rise to an almost completely smoothed ink surface.

FIG. 5 is a schematic sectional view of the configuration of the thermal printer according to the third embodiment, as viewed from the side. Also in this case, the same components as those of the first embodiment shown in FIG. 1 are designated by the same numbers as those of the configuration of FIG.

In the third embodiment, the upstream side and the immediate downstream side of the printing unit centering on the thermal head 6 are exactly the same as those shown in FIG. 1. In FIG. 1, the heat roller 12 and the press are used. The paper discharge portion made up of the rollers 13 is slightly different.

As shown in FIG. 5, the heat roller 12 'and the press roller 13' in the third embodiment also have the construction shown in FIG.
The configurations of the heat roller 12 and the press roller 13 are substantially the same. However, unlike the case of FIG. 1, the supply core 8'is arranged together with the guide roller 18 on the upstream side thereof, and the winding core 9 ', the peeling roller 19 and the facing core 9'on the downstream side thereof. A peeling roller 20 that is in pressure contact is provided.

A metal foil ribbon 21, which will be described in detail later, is wound and held on the supply core 8 '. The tip of the metal foil ribbon 21 has a guide roller 18 and a heat roller 1.
2'and the facing portion of the press roller 13 ', and the peeling roller 19
And the stripping roller 20 and the winding core 9'through the facing portion.

FIG. 6 shows an example of the structure of the metal foil ribbon 21. As shown in the figure, this metal foil ribbon 21
In the above, a copper foil Cu is attached over the entire surface on a base film similar to the above-mentioned ink ribbon 7 '.

Next, the operation of the main part of the third embodiment having the above configuration will be described. Also in this case, first, the paper P is automatically taken out from a paper storage (not shown) of the main body apparatus by a paper feed roller or the like, and the first and the second operations are performed until printing the colors Y, M, C, and Bk in this order. The operation is exactly the same as in the case of the second embodiment.

After the printing of the fourth color Bk is completed, in the case of the third embodiment, the paper P is immediately discharged from the printing section and conveyed to the opposing portion of the heat roller 12 'and the press roller 13'. To do. At the portion where the heat roller 12 'and the press roller 13' face each other, smoothing similar to that in the second embodiment by the heat roller 12 'is performed via the copper foil Cu of the metal foil ribbon 21 this time. Then, the paper P
Is a metal foil ribbon 21 on the smoothed transfer ink surface.
That is, the copper foil Cu is conveyed to the facing portion of the peeling roller 19 and the peeling roller 20 while being in close contact with the peeling roller 19. As a result, during this time, the smoothed transfer ink surface is cooled and solidified while being in close contact with the smooth copper foil Cu surface. And the peeling roller 19
After passing through the facing portion of the peeling roller 20, the copper foil Cu is peeled from the transfer ink surface together with the metal foil ribbon 21 and wound around the winding core 9 ′, and the paper P is discharged from the discharge port 14 to the outside.

In this way, the transfer ink surface smoothed as shown in FIG. 7 (b) is solidified while being in close contact with the surface of the smooth metal foil (in this case, copper foil). For this reason, the ink surface does not become rough due to the separation of the pressing surface before solidification, and therefore the ink surface that has been smoothed after the metal foil is peeled off is fixed in a perfect shape. As a result, a glossy printed image can be obtained.

Although the copper foil is used as the metal foil in the second and third embodiments, the metal foil is not limited to the copper foil.
The same result can be obtained with any metal as long as the metal has good thermal conductivity and can easily form a smooth surface. Furthermore, it is not necessary to limit to good thermal conductivity,
Similar results can be obtained with any member as long as it has a smooth surface and good peelability.

[0048]

As described above in detail, according to the present invention, the step of the ink surface coated by multicolor printing is smoothed by the smoothing means, and the ink surface is evenly finished. Since the surface is formed, it is possible to finish a beautiful glossy image.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a configuration of a thermal printer according to a first embodiment as viewed from a side surface.

FIG. 2 is a diagram showing a configuration example of an ink ribbon used in the first embodiment.

FIG. 3 is a schematic cross-sectional view of a configuration of a thermal printer according to a second embodiment as seen from a side surface.

FIG. 4 is a diagram showing a configuration example of an ink ribbon used in a second embodiment.

FIG. 5 is a schematic cross-sectional view of a configuration of a thermal printer according to a third embodiment as viewed from the side.

FIG. 6 is a diagram showing a configuration of a metal foil ribbon used for smoothing in a third embodiment.

7A is a diagram showing a state in which a layer of the first color and a layer of the second color are overlapped with each other to form a step, and FIG. 7B is a diagram showing the smoothed state.

[Explanation of symbols]

 1 First color layer 2 Second color layer 3 Step 5 Platen roller 6 Thermal head 7, 7'Ink ribbon 8, 8 'Supply core 9, 9' Winding core 10 Paper feed roller 11 Followed roller 12, 12 'Heat roller 13, 13 'Press roller 14 Discharge port 15 Discharge roller 16 Discharge roller 18 Guide roller 19 Separation roller 20 Separation roller 21 Metal foil ribbon P Paper

Claims (6)

[Claims] 1. A heating head having a plurality of heating elements in a main scanning direction and a platen are arranged so as to face each other, and an ink ribbon on which a plurality of colors of ink are repeatedly provided in a sub-scanning direction and a sheet are overlapped with each other. In a fusion type thermal transfer device that conveys the ink on an ink ribbon to a paper by forming a dot image by conveying the ink to a portion facing the platen and energizing the heating element, the ink surface transferred onto the paper is smoothed. A melting type thermal transfer device comprising: 2. A heating head having a plurality of heating elements is slidably arranged so as to face the platen, and an ink ribbon on which inks of a plurality of colors are repeatedly provided and a sheet are overlapped with each other to form the heating head and the platen. In a fusion type thermal transfer device which forms a dot image by repeating the transfer of the ink on the ink ribbon to the paper by energizing the heat generating element, the ink surface transferred to the paper is smoothed. A melting type thermal transfer device comprising: 3. The fusion type thermal transfer device according to claim 1, wherein the smoothing unit is a member that pressurizes and heats the ink surface. 4. The smoothing means is a smoothing member separate from a member for pressurizing and heating, and is pressed and heated to the ink surface by a member for pressurizing and heating. Item 3. A fusion type thermal transfer device according to item 1 or 2. 5. The smoothing member is a smoothing member provided on an ink ribbon, and is pressed against the ink surface and heated by the heating head. Fusion thermal transfer device. 6. The smoothing means is a smoothing member formed in a ribbon shape, and is pressed against and heated on the ink surface by a pressing and heating member. 4. The fusion type thermal transfer device described in 4.