JPH10114165A - Media ribbon and thermal transfer printer using the same - Google Patents

Abstract

(57) [Problem] To provide an ink ribbon and a thermal transfer printer which have a simple configuration and prevent skew of a sheet. A base film having a predetermined width (paper 1) is provided.
Ink 12 is applied (corresponding to the width of the printing surface 16 of No. 5), and a transparent or white hot-melt adhesive 13 is applied to the margins on both sides (corresponding to the left and right margins of the printing surface 16 of the paper 15). Thus, the ink ribbon 10 is formed. The hot-melt adhesive 13 has an adhesive strength stronger than the adhesive strength when the ink 12 is transferred to the paper 15. The print head 21 selectively heats the heating element according to the print data to cause the ink 1 of the ink ribbon 10 to be heated.
2 is transferred to the paper 15 and the heat-generating body of the hot-melt adhesive 13 is heated irrespective of the print data to transfer the hot-melt adhesive 13 to the margin 17 of the paper 15. Alternatively, the heating element in the portion of the hot-melt adhesive 13 is selectively heated so as to compensate for imbalance by detecting the right and left balance of the print data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printer which eliminates skew of a sheet due to imbalance in printing rate without complicating a mechanical mechanism.

[0002]

2. Description of the Related Art Conventionally, there is a thermal transfer printer as shown in FIG. FIG. 1 is a side sectional view showing a configuration of a main part of the thermal transfer printer. As shown in FIG. 1, in the thermal transfer printer, a print head 1 and a platen roller 2 are arranged to face each other.
Are conveyed together. At the time of printing, the print head 1 moves downward from a non-printing position indicated by a broken line 1 'in the drawing, and presses the ink ribbon 4 and the paper 3 against the platen roller 2 at a printing position indicated by a solid line in the drawing.

The ink ribbon 4 is composed of a long base film, Y (yellow: yellow) and M, which are three primary colors of subtractive color mixture.
(Magenta: red dye) and C (cyan: greenish blue) inks are arranged in a plane-sequential manner and applied. The ink ribbon 4 has its ink-coated surface pressed against the paper 3,
The printed portion is moved in the sub-scanning direction by being taken up by the take-up reel 7, and a new ink portion is pulled out from the holding reel 8 and supplied to the printing position.

The paper 3 is conveyed to the printing position with the rotation of the platen roller 2 while being pressed by the pressing roller 5, the ink is transferred, and separated from the ink ribbon 4 by the separation roller 6, and separated from the printing position. .

[0005] The print head 1 is disposed so as to extend in parallel with the main scanning direction of the platen roller 2 (perpendicular to the drawing).
A large number of heating elements are arranged in the main scanning direction corresponding to the maximum printable paper width. The heating element of the print head 1 is selectively heated and driven by a control unit (not shown) in accordance with image information, whereby heat energy is applied to the ink of the ink ribbon 4 to melt the ink and transfer it to the paper 3. Is done. Printing is performed in this manner.

The paper 3 is adhered to the ink ribbon 4 by the printing ink which has been transferred to the paper surface and solidified. In order to separate the sheet 3 from the ink ribbon 4, a separation roller 6 is provided. In color printing, FIG.
The paper 3 on which the first color ink has been transferred while being conveyed in the printing direction as shown by the arrow A is pulled back as shown by the arrow B in the same figure to transfer the next color ink, and again in the printing direction. While being conveyed, the next color ink is transferred from the printing start position.

If the above-mentioned printing (printing) is not an image but a sentence, the printing ratio (the occupation ratio of the ink on the paper) is about 5%, and the ink is distributed almost evenly on the paper. ing. However, in the case of an image, the printing ratio increases and the distribution of bright and dark portions is often not uniform, so that the printing ratio is often biased toward one side. For example, if a design or the like is fitted on the right side of the paper (recording paper) 3 shown in FIG.
The printing ratio of r becomes larger than the printing ratio of the left area PRA1 (PRA1 <PRAr). When the printing ratio is large, the amount of the transferred ink increases, and when the amount of the transferred ink is large, the adhesiveness of the paper 3 to the ink ribbon 4 increases accordingly.

Therefore, the paper 3 should be conveyed straight in the printing direction indicated by the arrow C as shown in FIG. 5 (a). On the other hand, the right side of the paper 3 has a slightly worse releasability from the ink ribbon, and the transport resistance on the right side of the paper 3 increases by that much, and as the paper 3 is transported as shown by the arrow D in FIG. Leaning on. That is, it skews to the right. Conversely, if the printing ratio of the left region PRA1 of the paper 3 becomes larger than the printing ratio of the right region PRAr (PRA1> PRAr), the releasability of the left side of the paper 3 is slightly reduced by the same operation as above, and the transport resistance is reduced. Becomes larger, and leans to the left as the paper is conveyed as shown by an arrow E in FIG. That is, it skews to the left.

In the case of one-color printing, there is no problem even if slight skew occurs. However, in the case of multi-color printing such as color printing, after printing with the previous color, the paper is pulled back and re-conveyed, and the next color is overpainted. When the paper 3 in FIG. 4 is pulled back, the print head 1 moves to the upper non-printing position 1 '. The ink ribbon 4 moves upward together with the print head 1 by the tension maintained between the take-up reel 7 and the holding reel 8 and is separated from the paper 3. The sheet 3 is pulled back in the skewed posture, and is transported again in the skewed posture. For this reason, a shift occurs in a position where the previous color and the next color are overlaid. As described above, when the sheet is skewed, the colors cannot be correctly applied. When a misregistration occurs in the color overlay, the image is blurred or moire fringes appear on the whole, and the image quality is significantly impaired.

Therefore, in order to prevent such a decrease in image quality, that is, to prevent the paper from skewing, that is, to reduce the influence of the adhesive force when the paper is peeled from the ink ribbon, Conventionally, a sheet is forcibly conveyed with a strong force. Then, in order to convey the paper with such a strong force, for example, on the one hand, knurling the surface of the platen roller (engraving countless minute tooth shapes) and the like, and on the other hand, the conveying force by the knurling In order to make the improvement effective, the pressing force between the press roller and the platen roller, which pinch and transport the paper, is made to work more, so that the paper is transported straight against the biased adhesive force. I was

[0011]

However, as described above, the knurling process is performed on the surface of the platen roller in order to properly maintain the paper conveyance posture that tends to be skewed due to the imbalance in the right and left printing rates. However, since it requires extremely advanced technology, there is a problem that the platen roller becomes expensive and the price of the main body device (thermal transfer printer) increases.

Further, in addition to this, increasing the pressing force between the press roller and the platen roller increases the load applied to each roller shaft portion, which causes fatigue with time and shortens the life of the main unit. Triggered the problem of becoming shorter.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances,
An object of the present invention is to provide a medium ribbon which prevents skew of a sheet with a simple configuration, and a thermal transfer printer using the same.

[0014]

According to the first aspect of the present invention, a print head and a platen are opposed to each other with a medium ribbon carrying an image forming medium for forming an image on a sheet and the sheet interposed therebetween. The image forming medium is transferred to the paper by printing by moving the ribbon and the paper relative to the print head in the sub-scanning direction of the print head and driving the print head to generate heat according to the print data. And a transfer medium that does not contribute to image formation is provided outside the area where the image forming medium is applied in the main scanning direction.

[0015] The transfer medium is formed so as to have an adhesive strength stronger than that of the image forming medium. Next, the invention according to claim 3 is:
A print head and a platen are opposed to each other across a sheet and a ribbon carrying an image forming medium for forming an image on the sheet, and the ribbon and the sheet are moved relative to the print head in the sub-scanning direction of the print head. A thermal transfer printer that transfers the image forming medium to the paper to perform printing by driving the print head to generate heat in accordance with print data, wherein the main scanning direction is the area where the image forming medium is coated. The image forming medium and the transfer medium are transferred to the sheet by the print head using a medium ribbon provided with a transfer medium that does not contribute to image formation outside the image forming apparatus.

The transfer medium is formed so as to have an adhesive strength stronger than the adhesive strength of the image forming medium, and the transfer medium is transferred to the transfer medium by heat generation of the print head. The applied energy is applied to compensate for the imbalance in the degree of dispersion of the print data in the main scanning direction.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a perspective view illustrating a configuration of an ink ribbon according to an embodiment. Same figure
(b) is a diagram showing the form of paper printed by the ink ribbon. As shown in FIG. 3A, the ink ribbon 10 (medium ribbon) is the inner surface of the base film 11 (the surface which is inward in the rolled state, the surface on the near side in FIG. 3A).
Is coated with ink 12 (image forming medium) with a predetermined width,
For example, a transparent or white hot-melt adhesive material 13 (colorless ink, transfer medium) that does not contribute to image formation is applied to the remaining margins on both sides (outside the area where the ink 12 is applied in the main scanning direction).

The application width of the ink 12 is formed corresponding to the width (main scanning direction) of the printing surface 16 of the paper 15 shown in FIG. The three types of ink, yellow, magenta, and cyan, or four types of ink obtained by adding black to these are divided into the sizes corresponding to the fifteen printing surfaces 16, and the four types of inks obtained by adding black to the three types are printed in the longitudinal direction (sub-scanning direction) of the base film 11. Are arranged side by side. Usually, the printing surface of the paper has margins at the top, bottom, left and right.

The hot-melt adhesive 13 of the ink ribbon 10
Are applied to the left and right margins 17 of the paper 15. In the present embodiment, the hot-melt adhesive 13
Exerts an adhesive strength which is much stronger than the adhesive strength exhibited when the ink 12 is melted and transferred to the paper 15.

FIG. 2 is a perspective view schematically showing a configuration of a main part of the thermal transfer printer according to the embodiment.
FIG. 1 also shows the ink ribbon 10 and the paper 15 shown in FIGS. 1 (a) and 1 (b). The respective components are denoted by the same reference numerals as those in FIGS. The overall configuration of the thermal transfer printer 20 shown in FIG. 2 is almost the same as the configuration of the thermal transfer printer shown in FIG. That is, the print head 21 and the platen roller 2 shown in FIG.
2, the configuration of the separation roller 23 and the take-up reel 24 is the same as the configuration of the print head 1, platen roller 2, separation roller 6, and take-up reel 7 shown in FIG.

FIG. 2 shows a paper pressing roller (disposed on the other side of FIG. 2) similar to the pressing roller 5 shown in FIG. 4 and an ink ribbon supply mechanism (FIG. 2) similar to the holding reel 8. (Which is disposed on the oblique upper right side) is not shown. The thermal transfer printer 20 has a paper feed mechanism for feeding the paper 15 to a printing unit where the print head 21 and the platen roller 22 are pressed against each other, and a detecting mechanism for detecting the movement position of the paper 15 and the ink ribbon 10. Although a plurality of sensors, a driving mechanism for driving these, and a control circuit for controlling these driving mechanisms are provided, they are not shown.

Next, the operation of the thermal transfer printer 20 having the above configuration will be described with reference to the flowchart of FIG. still,
This processing is executed by controlling the respective units by the control circuit (not shown).

In the flowchart shown in FIG. 1, first, initial settings are made (step S1). This process is a process of setting each unit to an initial reference state. In this initial setting, the initial setting of each section is sequentially performed, and finally the initial setting of the print head 21 is performed. That is, it is determined whether or not the print head 21 is at the initial position (refer to the non-print position indicated by the broken line 1 'in FIG. 4) (step S2).
When the print head 21 is not set at the initial position such as being lowered to the print position (S2 is n),
By driving the motor of the print head support mechanism, the print head 21
Is moved to the initial position (step S3), and the sheet 15 is fed to the printing unit (step S4). In step S2, if the print head 21 is at the initial position, the process of step S3 is immediately performed.

In this sheet feeding process, a plurality of sheets are fed to a holding portion formed by a pressing roller (see the pressing roller 5 in FIG. 4) and the platen roller 22 which are not visible in FIG. The paper 15 taken out one by one from the paper cassette in which is stored or the paper 15 inserted one by one from the paper feed port is fed by the paper feed mechanism on the far right side in FIG. In this feeding, although not shown in FIG. 2, a paper sensor is provided near the upstream side (diagonally near the left in FIG. 2) from the separation roller 23, and the leading end of the paper 15 slightly passes the separation roller 23. Is detected by the paper sensor. The control circuit recognizes this detection and temporarily stops the driving of the feeding mechanism.

Subsequently, the cueing of the first color (yellow in this embodiment) of the ink ribbon 10 is performed (step S5). In this process, while the take-up reel 24 is driven to rotate, the ink ribbon 10 is wound and moved in the printing direction, the ink is directly detected by the optical sensor for each color, or a mark provided at each boundary of the ink. To detect the position of the color ink. As a result, the printing start position of the yellow color ink is set in the printing portion (the portion where the print head 21 and the platen roller 22 face each other).

Next, it is determined whether the state of the fed paper 15 is normal, that is, whether a paper jam or the like has occurred (step S6).
Then, it is determined whether or not the transport state of the ink ribbon 10 is normal (ribbon jam state) (step S7). These detections are all performed using sensors.

If it is determined in step S7 that the state of the ink ribbon 10 is normal (y in S7), the print head 21 is moved to a printing position (step S8). In this process, the print head 21 waiting at the initial position is lowered to the print position. This allows
The print head 21 sandwiches the ink ribbon 10 and the paper 15 by being overlapped with the platen roller 22 and presses the platen roller 22 through these. Next, platen roller 2
2 is rotated in the printing direction, and the paper 15 and the ink ribbon 1 are rotated.
0 in the printing direction, the paper 15 and the ink ribbon 10
Is set in the printing section (step S9).
Thereafter, the print head 21 is kept pressed against the platen roller 22 until printing is completed.

Following the above, whether or not the printing is ready,
That is, the print head 21 normally descends to the print position,
It is determined whether or not the ink ribbon 10 has been normally pushed down to the printing unit as the print head 21 descends (step S10). If the ink ribbon 10 has been used and cannot be pulled out from the holding reel, and there is a problem such as the print head 21 not being lowered due to the push-down resistance (S10: n), an operation panel (not shown) informs the user. Error processing such as blinking of a lamp is performed (step S1).
1). Also, when it is detected in step S7 that a jam or the like has occurred in the ink ribbon 10 (n in S7), the process immediately proceeds to step S11 to perform error processing. The same applies to the case where a paper jam or the like is detected in step S6.

On the other hand, when it is confirmed in step S10 that the printing preparation is completed (S10: y), printing of the first color is performed (step S12). In this process, the platen roller 22 conveys the paper 15 to the front left side in FIG. 2 by the frictional force. The paper 15 is a platen roller 22
The ink ribbon 10 is conveyed so as to be caught between the ink ribbon 10. The ink ribbon 10 is taken up by the take-up reel 24 in synchronization with the peripheral surface speed of the platen roller 22 while applying an appropriate tension so that the ink ribbon 10 does not sag.

Printing is started when the leading end of the printing position of the paper 15 reaches the heat generating portion of the print head 21.
The print head 21 selectively causes the heating element to generate heat according to image information (print data) under the control of the control circuit, and transfers the yellow ink of the ink ribbon 10 to the paper 15. After passing through the printing unit, the paper 15 is conveyed while being peeled to the paper discharge side by the separation roller 23 so that the paper 15 is not taken up by the ink ribbon 10 due to the adhesive force of the transferred ink.

In the present embodiment, in the above printing process, the print head 21 further causes the heating element corresponding to the hot-melt adhesive 13 to generate heat irrespective of print data, thereby causing the hot-melt adhesive 13 to be heated. Margin 17 on the side of paper 15
Transfer to Thereby, the ink ribbon 10 of the paper 15 is
Adhesion to the transfer ink becomes extremely high on both sides, and even on the printing surface 16 at the center, the printed pattern 25 is arranged on one side as shown in FIG. Even if the balance occurs, the imbalance is absorbed by the strong adhesiveness of both sides, and therefore, the skew of the sheet 15 due to the imbalance of the adhesive force resulting from the uneven arrangement of the transfer ink is suppressed, and the normal The degree of skew is reduced as compared with the case where printing is performed using the ink ribbon.

It should be noted that instead of uniformly heating the heating element in the portion corresponding to the hot-melt pressure-sensitive adhesive 13 as described above, the left-right balance of the print data is detected and the imbalance is compensated. The heating element corresponding to the hot-melt adhesive 13 may be selectively heated. In this case, the hot-melt adhesive material 1 which is stronger than the ink 12 but is
A hot-melt adhesive material having a weaker adhesiveness than 3 can be used. Further, the skew of the sheet can be more effectively eliminated.

After the above printing process is completed, the print head 21
Is moved to the initial position (step S13). Thereby, in any direction (arrows A and B in FIG. 4)
(See Reference) The transport of the paper 15 becomes easy.

Subsequently, it is determined whether or not printing of the next color is to be executed (step S14). In this process, the control circuit stores the color of the ink that has just been printed based on the ink ribbon position detected by the ink ribbon position sensor before the start of printing, and refers to the progress of color printing to the next step. Then, it is determined whether or not there is a print color, and thereby, it is determined whether or not to print the next color.

When there is a color to be printed next (S14: y), the paper 15 is pulled back to the paper supply side (Step S15), and then the next color ink is cueed (Step S16). . This processing is similar to step S5.
While rotating the take-up reel 24 to take up the ink ribbon 10 and move it in the printing direction, the next ink color is detected by the optical sensor or the next mark is provided at each ink boundary. This is a process of detecting that the color ink has been transported to a predetermined position.

After completing the cueing of the ink position of the next color, the process returns to step S6 and returns to steps S6 to S1.
Repeat 6. Thereby, the color overlay printing of three colors of yellow, magenta, and cyan (or four colors of black) further progresses.

Then, in any case, as described above,
In step S12, regardless of the print data, the heating element in the portion corresponding to the hot-melt adhesive 13 is heated to transfer the hot-melt adhesive 13 to the margin 17 on the side of the paper 15 so that both sides of the paper 15 The strong adhesiveness formed in the portion absorbs the imbalance of the releasability resulting from the uneven arrangement of the transfer ink, thereby preventing the paper 15 from skewing. As a result, the three-color or four-color image is overlaid on the correct position. When the printing of the three or four colors is completed, and it is determined in step S14 that there is no next printing color (n in S14), the paper 15 is discharged out of the machine (step S17).

In the above-described embodiment, the heat-meltable adhesive is applied to the surplus of the ink ribbon. However, the adhesive applied to the surplus of the ink ribbon is not limited to this. It is also possible to apply a glue that is appropriately strengthened in adhesiveness that can be peeled off after sticking used in it or the like. In this case, the print head is not required to generate heat for the surplus portion of the ink ribbon, and a pressing force enough to allow the adhesive to adhere to the paper at both ends of the pressing roller is applied to the platen roller. Good.

[0039]

As described in detail above, according to the present invention, the paper is adhered to the ribbon by transferring the adhesive material to both sides of the paper so that the paper has a peel resistance almost balanced to the left and right. The skew of the sheet due to the imbalance in the printing rate is eliminated, and therefore, a stable color superposition operation is guaranteed and the quality of the image is improved. In addition, since the adhesive on the lower side of the printing rate among the adhesives on both sides of the ribbon is thermally transferred according to the bias of the printing rate, the peeling resistance of the paper from the ribbon can be evenly dispersed. As a result, the skew of the sheet is eliminated and stable color overlay printing can be performed, and therefore, the quality of the image is improved.

[Brief description of the drawings]

FIG. 1A is a perspective view illustrating a configuration of an ink ribbon (medium ribbon) according to an embodiment, and FIG. 1B is a diagram illustrating a form of a sheet printed by the ink ribbon.

FIG. 2 is a perspective view schematically illustrating a configuration of a main part of the thermal transfer printer according to the exemplary embodiment.

FIG. 3 is a flowchart illustrating a processing operation of the thermal transfer printer according to the exemplary embodiment.

FIG. 4 is a side sectional view showing a configuration of a main part of a conventional thermal transfer printer.

FIGS. 5A, 5B, and 5C are diagrams illustrating skew generated on a sheet according to a printing ratio.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 print head 2 platen roller 3 paper 4 ink ribbon 5 press roller 6 separation roller 7 take-up reel 8 holding reel PRAr print area on right side of paper PRA1 print area on left side of paper 10 Ink ribbon (medium ribbon) 11 base film 12 ink (Image forming medium) 13 Hot-melt adhesive material (transfer medium) 15 Paper 16 Printing surface 17 Margin 20 Heat transfer printer 21 Print head 22 Platen roller 23 Separation roller 24 Take-up reel 25 Printing pattern

Claims (5)

[Claims] 1. A print head and a platen are opposed to each other across a sheet and a medium ribbon carrying an image forming medium for forming an image on the sheet, and the medium is attached to the print head with respect to the print head. A medium ribbon used in a thermal transfer printer that transfers the image forming medium to the paper and performs printing by relatively moving the printing head in accordance with print data by moving the printing head in the sub-scanning direction. A medium ribbon provided with a transfer medium that does not contribute to image formation outside a region where the image formation medium is applied in the main scanning direction. 2. The medium ribbon according to claim 1, wherein the transfer medium is formed so as to have an adhesive strength higher than that of the image forming medium. 3. A print head and a platen are opposed to each other across a sheet and a ribbon carrying an image forming medium for forming an image on the sheet, and the ribbon and the sheet are attached to the print head by a sub-head of the print head. A thermal transfer printer that relatively moves in a scanning direction and drives the print head to generate heat according to print data, thereby transferring the image forming medium to the paper and performing printing, wherein the image forming medium is coated. A thermal transfer printer, wherein the image forming medium and the transfer medium are transferred onto the sheet by the print head using a medium ribbon provided with a transfer medium that does not contribute to image formation outside a region in the main scanning direction. 4. The thermal transfer printer according to claim 3, wherein the transfer medium is formed so as to have an adhesive strength higher than that of the image forming medium. 5. The thermal transfer according to claim 3, wherein the energy applied to the transfer medium by the heat generation drive of the print head is applied to compensate for imbalance in the degree of dispersion of print data in the main scanning direction. Printer.