JP2011212998A - Multicolor thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce uneven feeding and cockles in a multicolor thermal transfer printer.SOLUTION: The multicolor thermal transfer printer includes thermal transfer units printing images of a plurality of color inks. A master roll is supplied to the thermal transfer unit, and is nipped by a thermal head 13 and a platen 12 together with an ink ribbon in the thermal transfer unit. By supplying thermal energy to each heating element 36 of the thermal head 13 by application of electricity, transfer is performed so that images of the respective color inks are overlapped. The multicolor thermal transfer printer includes: a platen warming means warming the platen 12; and a warming control means performing warming control of the platen 12 before printing of the respective color inks is started. Thermal energy at a level preventing transfer of ink to non-printing parts 43 which are positioned before a printing start end 42 of a printing part 41 of the master roll to be printed and after a printing terminal 42a of the printing part 41 is applied to the heating elements 36 of the thermal head 13 by application of electricity.

Description

  The present invention relates to a multi-color thermal transfer printer including a thermal transfer unit that forms an image by transferring a plurality of color inks.

  2. Description of the Related Art Conventionally, thermal transfer printers that include a plurality of thermal transfer units that transfer images of predetermined colors to form images are known. In this thermal transfer printer, in each thermal transfer unit, a continuous raw material is sandwiched between a thermal head and a platen together with an ink ribbon film base material, and predetermined thermal energy is applied to the ink of the film base material, whereby an image of each color ink is formed. It is designed to be transferred to a continuous web.

  On the other hand, although different from the configuration of the printer of the present invention, in other printers, the printing paper generally has a print portion to which ink is transferred and a non-print portion to which ink is not transferred. It is known that a speed fluctuation caused by a difference in frictional force is caused by a difference in calorie between the printing part and the non-printing part, resulting in feed unevenness (darkness unevenness).

  In addition, it is known that a tension difference caused by a difference in frictional force is generated due to a difference in heat quantity between a printed portion and a non-printed portion in the width direction during printing, and wrinkles are generated.

  Further, in order to solve such a problem, a thermal printer is known in which pre-heating is applied to the non-printing portion downstream from the printing start end at the start of printing to reduce feed unevenness due to a difference in friction coefficient ( (See Reference 1).

  Also known is a thermal transfer printer that preheats the non-printed portion in the width direction of the printing paper, eliminates the tension difference between the printed portion and the non-printed portion when the ink ribbon film is rolled up, and prevents wrinkles. (See Reference 2).

Japanese Patent No. 3197136 Japanese Patent No. 3329267

  In conventional multicolor thermal transfer printers, a feed roller for running an original fabric such as a film is arranged downstream of each thermal transfer unit, and each feed roller is rotated by a stepping motor to feed the original fabric. Yes. According to this feeding method, there is a problem that speed fluctuation is likely to occur in the original fabric, and unevenness of feeding is likely to occur due to this, and high-precision halftone dot printing becomes difficult. That is, in the conventional multicolor thermal transfer printer, since the original fabric is pulled on the downstream side of the thermal head in each thermal transfer unit, it is difficult to prevent the speed variation from occurring in the original fabric during printing. When speed fluctuation occurs, feed unevenness and color misregistration may occur. Further, in such a multi-color thermal transfer printer, simply transferring ink causes a tension difference and a speed fluctuation caused by a difference in frictional force due to a difference in heat amount between the printing part and the non-printing part as described above. , Wrinkles and feed unevenness occur.

  The present invention is a multicolor thermal transfer printer which can solve such problems as one of the problems, reduce the occurrence of feed unevenness and wrinkles, and can print images with high definition and multicolor on the printing paper with thermoplastic resin ink. Is to provide.

  In order to solve the above problems, the present invention employs the following configuration. In addition, although the code | symbol with a parenthesis is attached | subjected in order to make an understanding of this invention easy, this invention is not limited to this.

  In other words, the multicolor thermal transfer printer according to claim 1 includes a thermal transfer unit that prints an image of a plurality of color inks, supplies the original fabric to the thermal transfer unit, and the original fabric is a thermal head together with the ink ribbon in the thermal transfer unit. Platen heating means for heating the platen in a multi-color thermal transfer printer that is transferred so that the images of the respective color inks are superimposed by passing thermal energy to the heating elements of the thermal head And heating control means for controlling the heating of the platen before starting the printing of each color ink, and the heating element of the thermal head reaches the printing start end of the printing portion to be printed on the original fabric. Thermal energy is applied so that ink is not transferred to the non-printing portion from the front to the end of printing of the printing portion.

  The multicolor thermal transfer printer according to claim 2 is characterized in that, in the multicolor thermal transfer printer according to claim 1, a rotary shaft of a constant speed control type servo motor is directly connected to the platen of the thermal transfer unit. And

  Further, the multicolor thermal transfer printer according to claim 3 is the multicolor thermal transfer printer according to claim 2, wherein the multicolor thermal transfer printer includes a plurality of thermal transfer units each printing an image of a predetermined color ink. The continuous raw material is supplied to each thermal transfer unit, and the continuous raw material is sandwiched between the thermal head and the platen together with the ink ribbon in each thermal transfer unit, and heat energy is supplied to each heating element of the thermal head. Thus, a multi-color thermal transfer printer that transfers images of each color ink so as to overlap each other, and the rotation axis of each constant-speed controlled servo motor is directly connected to the platen of the total thermal transfer unit, so that On the other hand, the rotation of the platen is controlled so that it can run in the total thermal transfer unit at the same constant speed.

  The multicolor thermal transfer printer according to claim 4 is the multicolor thermal transfer printer according to claim 3, wherein the rotational speed of the platen in another thermal transfer unit is based on the rotational speed of the platen in any one thermal transfer unit. Is controlled.

  The multicolor thermal transfer printer according to claim 5 is the multicolor thermal transfer printer according to claim 3, wherein a feed roller for running the continuous raw material is provided at a predetermined position, and the rotational speed of the feed roller is used as a reference. The rotational speed of the platen in the thermal transfer unit is controlled.

  The multicolor thermal transfer printer according to claim 6 is the multicolor thermal transfer printer according to claim 3, wherein the tension detector detects the tension of the continuous raw fabric at a predetermined position, and tension adjustment driven by a servo motor. A roller is provided, and the number of rotations of the servo motor is controlled based on the tension detected by the tension detector, whereby the tension of the continuous raw fabric is adjusted.

  Further, the multicolor thermal transfer printer according to claim 7 is the multicolor thermal transfer printer according to claim 3, wherein the continuous original fabric passing between the platen and the thermal head is transferred to the platen before and after the thermal head. A nip roller for pressing is provided.

  According to the present invention, it is possible to reduce or prevent wrinkles and feed unevenness by heating the platen and further reducing the difference in the amount of heat between the application part and the non-application part, and a detailed multicolor image can be printed stably.

It is a schematic diagram which shows the layer structure of the transfer foil printed by the multicolor thermal transfer printer which concerns on this invention. It is a schematic diagram which shows the layer structure of the injection molded product in which the image of transfer foil was transcribe | transferred. 1 is a schematic front view of an embodiment of a multicolor thermal transfer printer according to the present invention. It is a schematic front view of one thermal transfer unit in a multicolor thermal transfer printer. FIG. 5A is an external view showing an arrangement example of the platen and the heating roller, and FIG. 5B is a cross-sectional view of the platen and the heating roller. It is sectional drawing which shows the structural example of a thermal head. It is a figure which shows the printing part and non-printing part of the continuous transfer foil original fabric printed with the multicolor thermal transfer printer of this invention. It is a schematic front view which shows other embodiment of the multicolor thermal transfer printer which concerns on this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

<Embodiment 1>
First, the transfer foil printed by this multicolor thermal transfer printer will be described.

  As shown in FIG. 1, the transfer foil 1 has a layer structure in which a release layer 3, a protective layer 4, an ink receiving layer 5, and an ink layer 6 are sequentially laminated on a base material layer 2. Among these, the layer constituting portion from the base material layer 2 to the ink receiving layer 5 is a continuous transfer foil original fabric 7 which is a kind of continuous original fabric, and is supplied to a later-described multicolor thermal transfer printer for printing.

  The base material layer 2 is formed of, for example, a PET (polyethylene terephthalate) film, paper, foil, or the like, and the protective layer 4 is formed of, for example, a UV curable acrylic resin. The release layer 3 and the protective layer 4 are also formed of known materials that need not be exemplified. The protective layer 4 and the ink receiving layer 5 are formed of a transparent material or a translucent material so that an image formed by the ink layer 6 can be seen through.

  The ink layer 6 is formed of a known thermoplastic resin ink. The ink layer 6 is formed by printing thermoplastic inks of various colors such as yellow, red, and indigo on the ink receiving layer 5 of the continuous transfer foil original fabric 7, thereby transferring the desired image on the transfer foil. 1 is made.

  As shown in FIG. 2, the transfer foil 1 is used for decorating the surface of the injection molded product 8 with a desired image.

  That is, the transfer foil 1 is attached to the mold so that the base material layer 2 is in contact with the cavity surface of an injection mold (not shown), and then the molten synthetic resin is injected into the mold. Then, simultaneously with the injection molding, the transfer foil 1 sticks to the surface of the injection resin 9 from the ink layer 6 side. After the injection molded product 8 is taken out from the mold, the substrate layer 2 and the like of the transfer foil 1 are removed, so that an image copied from the transfer foil 1 is exposed on the surface of the injection molded product 8. Thereby, the injection molded product 8 on which a fine and beautiful image is displayed is completed. Since the surface of the ink layer 6 is covered and protected by the protective layer 4, the surface of the injection molded product 8 is decorated with a beautiful image over a long period of time.

  Next, a multicolor thermal transfer printer for printing the transfer foil 1 will be described.

  As shown in FIG. 3, in this multicolor thermal transfer printer, a plurality of thermal transfer units I, II, III, and IV, each printing an image of a predetermined color ink on a continuous transfer foil original fabric 7, are arranged in series. It is constituted by.

  When viewed in the flow direction of the continuous transfer foil original fabric 7 in the multicolor thermal transfer printer, a feed roll 7a for feeding the unprinted continuous transfer foil original fabric 7 is installed on the upstream side, and an already printed web is provided on the downstream side. A take-up roll 7b for winding the continuous transfer foil original fabric 7 is provided. The rotating shafts of the vector inverter motors 24 and 25 are connected to the winding cores of the feeding roll 7a and the winding roll 7b, respectively. The rotations of both rolls 7a and 7b are controlled by the vector inverter motors 24 and 25 so that the continuous transfer foil original fabric 7 travels between the rolls 7a and 7b at a predetermined speed.

  The thermal transfer units I, II, III, and IV are indigo, red, yellow, white from the upstream side to the downstream side of the continuous transfer foil original fabric 7 between the feeding roll 7a and the winding roll 7b. Are arranged to print each color ink. Of course, the arrangement of the thermal transfer units I, II, III, and IV is not limited to the order of indigo, red, yellow, and white. Also, the unit is not limited to four units, but may be three units of three color printing or two units of two color printing, or additional units may be added from four units so that other color inks can be further printed. Also good.

  As shown in FIG. 4, the thermal transfer unit I for indigo ink is provided with guide rollers 10 and 11 for detouring the continuous transfer foil original fabric 7 running in the horizontal direction upward. Above these guide rollers 10 and 11, a platen 12 for running a detoured continuous transfer foil original fabric 7 is disposed. Above the platen 12, the thermal head 13 is disposed so as to face the platen 12. An indigo ink ribbon 14 is disposed between the platen 12 and the thermal head 13.

  The platen 12 is a roll whose surface is covered with rubber. The platen 12 is directly connected to the rotating shaft of a constant speed control type servo motor 22.

  As shown in FIG. 4, nip rollers 15 and 15 that respectively press the continuous transfer foil original fabric 7 passing between the platen 12 and the thermal head 13 against the platen 12 before and after the thermal head 13 are used as necessary. Provided. The continuous transfer foil original fabric 7 is pressed against the surface of the platen 12 by the nip rollers 15 and 15, thereby preventing slippage between the continuous transfer foil original fabric 7 and the platen 12. As a result, the image is printed more finely and beautifully.

  In addition, the multicolor thermal transfer printer of this embodiment includes a heating unit that heats the platen 12. For example, as shown in FIG. 4, a far-infrared heater 16 is used as the heating means, and the far-infrared heater 16 is installed below the platen 12. The far-infrared heater 16 is controlled to heat the platen 12 to a predetermined temperature (preferably a saturation temperature during continuous printing) before the multicolor thermal transfer printer starts printing. Since the surface of the platen 12 is made of rubber, the platen 12 accumulates heat by continuing printing, the diameter fluctuates, and the traveling speed of the continuous transfer foil original fabric 7 changes accordingly. This heating means changes the platen 12. Such inconvenience can be eliminated by preheating to a saturation temperature during continuous printing.

  In this embodiment, the far-infrared heater 16 is used as the heating means. However, for example, as shown in FIG. 5B, the far-infrared heater 16 is wound into a coil connected to the power supply unit 35 for applying electricity. You may use the roller 30 for a heating provided with the nichrome wire 32 inside. In this case, the heating roller 30 is arranged so as to contact the platen 12 as shown in FIG. The surface of the heating roller 30 is controlled by heating the nichrome wire 32 by applying electricity. Then, the platen 12 is heated by the contact with the heated heating roller 30, and the temperature around the thermal head 13 and the temperature around the platen 12 are controlled to be substantially constant.

  In addition, a conventionally known technique can be used as a heating method for heating the platen 12 such as applying hot air to the surface of the platen 12.

  The thermal head 13 can move up and down in the vertical direction, and presses the ink ribbon 14 toward the platen 12 as shown in FIG. 4 when printing an image.

  The thermal head 13 includes a plurality of heating elements 36 that are arranged in a line and have resistors corresponding to resolution. Further, as shown in FIG. 6, the thermal head 13 has a large heat capacity such as a ceramic substrate 37 to which the heat generating element 36 is attached and aluminum attached to the ceramic substrate 37 with a conductive adhesive or the like. And a heat radiator 38 made of a material. Further, the heat radiating body 38 is provided with a heat radiating fin 39 and a fan 40 for radiating the heat stored in the heat radiating body 38 to the outside.

  Then, predetermined heat energy is applied to each heating element 36 of the thermal head 13, and the ink of the ink ribbon 14 corresponding to each heating element 36 is transferred to the continuous transfer foil original fabric 7, thereby printing a predetermined print image. The ink layer 6 for forming is formed.

  Further, at the time of printing, the boundary between the printed portion and the non-printed portion is caused by a heat amount difference between the printed portion indicating the portion to be printed in the continuous transfer foil original fabric 7 and the non-printed portion excluding the portion to be printed. In this case, the frictional force changes, and uneven feeding (shading unevenness) and wrinkles occur. Therefore, in the multi-color thermal transfer printer according to the present embodiment, when the ink is transferred to the printing unit 41, the thermal energy that does not transfer the ink to the non-printing unit 43 of the continuous transfer foil original fabric 7 (see FIG. 7). Is energized to each heating element 36 of the thermal head 13.

  In addition, the multicolor thermal transfer printer of this embodiment includes a heating unit that heats the thermal head 13. As shown in FIG. 6, for example, the heating means of the present embodiment wraps a nichrome wire 47 connected to a power supply unit 46 that applies electricity to the radiating fin 39, and applies electricity to the nichrome wire 47 to apply nichrome. The thermal head 13 is heated by heating the wire 47 and conducting the heat to the radiating fins 39. The heating means controls the heating of the thermal head 13 to a predetermined temperature (saturation temperature during continuous printing) before printing, and keeps the temperature around the thermal head 13 and the temperature around the platen 12 substantially constant. Controlled to sag.

  The heating means for heating the thermal head 13 is not limited to the nichrome wire 47, and other conventionally known heating means can be applied.

  By the way, as shown in FIG. 3, the ink ribbon 14 in the thermal transfer unit I for indigo color ink is formed by applying indigo color ink to the surface of a continuous film or the like, and its feeding roll 14a and take-up roll 14b are provided. The platen 12 and the thermal head 13 are arranged so as to be sandwiched from the upstream side and the downstream side of the continuous transfer foil original fabric 7. The feed roll 14a and the take-up roll 14b of the ink ribbon 14 are controlled so that the ink ribbon 14 travels around the platen 12 at the same speed as the continuous transfer foil original fabric 7 during printing shown in FIG.

  When the platen 12 is rotated at a constant speed by the constant speed control servo motor 22, the continuous transfer foil original fabric 7 is moved between the platen 12 and the thermal head 13 at a constant speed equal to the peripheral speed of the platen 12 and the ink ribbon 14. While passing in an overlapping state, an image of indigo ink is thermally transferred onto the surface.

  The thermal transfer unit I for indigo color ink is configured as described above, but the thermal transfer units II, III, and IV for other color inks are also configured in the same manner. However, only the ink color of the ink ribbon 14 is different. Therefore, detailed description of the thermal transfer units II, III, and IV of other color inks is omitted.

  The constant speed controlled servo motors 22 that drive the platens 12 of the thermal transfer units I, II, III, and IV of the respective colors are controlled by the control unit 17 so that all of them move the continuous transfer foil original fabric 7 at the same constant speed. Controlled by. Specifically, the constant speed control type servo motor 22 for driving the platen 12 is provided in the same number of four as the number of printing colors, and the other three rotation speeds are based on the desired one rotation speed. It is controlled to have the same rotational speed. Thereby, the continuous transfer foil original fabric 7 is fed in one direction by the platen 12 of each color, and the image of each color is printed on the surface without causing color misregistration.

  As described above, the continuous transfer foil original fabric 7 is moved under the thermal head 13 in each unit I, II, III, IV at the same constant speed by the platen 12 of each color thermal transfer unit I, II, III, IV. If the printing is continued in this state, the tension of the continuous transfer foil original fabric 7 gradually changes, which causes a color shift. If the tension is too low, the continuous transfer foil original fabric 7 will loosen, causing meandering or misalignment at the start of printing. If the tension is too high, the film will slip between the drive rollers and will not be conveyed normally.

  In order to prevent this, as shown in FIG. 3, for example, between the feeding roll 7a of the continuous transfer foil original fabric 7 and the leading thermal transfer unit I, or the trailing thermal transfer unit IV and the winding roll 7b. Are provided with a tension detector 18 and tension adjusting rollers 19a and 19b, respectively.

  For example, a servo motor 23 is connected to one of the tension adjusting rollers 19a and 19b. The deviation between the tension detected by the tension detector 18 and the appropriate tension is sent to the servo motor 23 via another control unit (not shown). When the controlled driving force of the servo motor 23 is transmitted to the tension adjusting roller 19b, the continuous transfer foil original fabric 7 is kept constant in tension while the plurality of thermal transfer units I, II, III, IV. The image without color misregistration is printed.

  The tension detector 18 is also provided for the vector inverter motors 24 and 25 for rotating the feeding roll 7a and the winding roll 7b of the continuous transfer foil original fabric 7, respectively. The deviation between the tension detected by the tension detector 18 and the appropriate tension is also sent to the vector inverter motors 24 and 25 via the other control unit (not shown). The controlled driving force of the vector inverter motors 24 and 25 is transmitted to the feeding roll 7a and the take-up roll 7b, respectively, so that the tension of the continuous transfer foil original fabric 7 is kept constant.

  The multicolor thermal transfer printer according to the present embodiment particularly has a frictional force generated due to a difference in heat amount between the printing unit and the non-printing unit and a surrounding environmental temperature fluctuation of the thermal energy applied during ink transfer to the printing unit 41. In order to prevent unevenness in feeding and wrinkles due to changes in temperature, the heating temperature control of the platen 12 and the thermal head 13 keeps the environmental temperature constant and brings the difference in heat quantity between the printed part and non-printed part applied during printing closer. Thus, the frictional force is kept constant to prevent feed unevenness and wrinkles. At this time, in the multi-color thermal transfer printer of this embodiment, either one or both of the heating means for heating the platen 12 and the thermal head 13 according to the surrounding environment are used.

  In the multicolor thermal transfer printer of this embodiment, either one or both of the platen 12 and the thermal head 13 are heated, and ink is not transferred in the non-printing portions 43 at both ends in the width direction of the printing portion 41. In order to reduce the generation of wrinkles due to the difference in tension by energizing each heating element 36 of the thermal head 13 with a degree of thermal energy, Thermal energy that does not transfer ink is applied to each heating element 36 of the thermal head 13 to reduce the occurrence of unevenness in feeding due to the difference in frictional force. Thus, the printing portion 41 and the non-printing portion that are applied during printing. By reducing the heat quantity difference of 43, wrinkles and feed unevenness can be reduced or prevented, and a stable print can be obtained from printing to the end of printing.

  Next, the operation of the multicolor thermal transfer printer will be described based on the first to third embodiments.

Example 1
In this embodiment, in the tandem type multi-color thermal transfer printer, the platen 12 and the thermal head 13 are controlled to be heated, and the printing portion on which the continuous transfer foil original 7 is to be printed at the time of ink transfer to the printing portion 41. The non-printing portion 43 from before reaching the print start end 42 of the print 41 to the print end end 42a of the print portion 41 is given thermal energy that does not transfer ink to reduce feed unevenness and wrinkles. This makes it possible to print various images.

  At the start of printing, as described above, the heating control of the platen 12 and the thermal head 13 is controlled to the saturation temperature during continuous printing using both the heating means of the platen 12 and the heating means of the thermal head 13.

  Further, the feed roll 7a and the take-up roll 7b of the continuous transfer foil original fabric 7 are rotated by driving of the respective vector inverter motors 24, 25, and the continuous transfer foil original fabric 7 is transferred to the thermal transfer units I, II, Drive in III and IV.

  In each color thermal transfer unit I, II, III, IV, the platen 12 is rotated at a constant speed by driving a constant speed control type servo motor 22 and the continuous transfer foil original fabric 7 is moved from the upstream side to the downstream side. And send. At that time, the thermal head 13 presses the ink ribbon 14 against the continuous transfer foil original fabric 7 on the platen 12 to transfer the corresponding color ink as an image to the continuous transfer foil original fabric 7.

  When the color ink is transferred, each heating element 36 of the thermal head 13 has the print portion of the print portion before the print start end 42 of the print portion 41 of the continuous transfer foil original 7 to be printed. The non-printing portion 43 up to the printing end end 42a is energized with thermal energy that does not transfer ink.

  Further, all the platens 12 in the thermal transfer units I, II, III, and IV of the respective colors are rotated at the same constant speed under the control of the constant speed control type servo motor 22 by the control unit 17. Each color image is overprinted without shifting.

  The continuous transfer foil original fabric 7 on which an image has been formed by printing all the colors is wound as a continuous transfer foil 1 on a winding roll 7b.

  When the printing is continued, the tension of the continuous transfer foil original fabric 7 may gradually change. Therefore, the tension of the continuous transfer foil original fabric 7 is detected by the tension detector 18 during printing, and compared with the appropriate tension, a signal for eliminating the deviation is sent to the vector inverter motors 24 and 25 via a control unit (not shown). Or sent to the servo motor 23.

  The controlled driving force of the vector inverter motors 24 and 25 and the servo motor 23 is transmitted to the tension adjusting roller 19a, the feeding roll 7a, and the take-up roll 7b, so that the continuous transfer foil original fabric 7 has a constant tension. Passing through the plurality of thermal transfer units I, II, III, and IV while being maintained, a fine and beautiful image without color misregistration is printed.

  The continuous transfer foil original fabric 7 wound around the winding roll 7b is attached to a molding machine in a wound state and used as the transfer foil 1.

-Example 2-
In this embodiment, in the tandem type multicolor thermal transfer printer, the thermal head 13 is controlled to be heated, and the printing of the printing portion 41 to be printed on the continuous transfer foil original fabric 7 is performed at the time of ink transfer to the printing portion 41. The non-printing portion 43 from before reaching the start end 42 to the printing end end 42a of the printing portion 41 is given thermal energy to the extent that ink is not transferred to reduce feed unevenness and wrinkles, and to display a detailed image. It can be printed.

  At the start of printing, as described above, the thermal head 13 is controlled to be heated to the saturation temperature during continuous printing using only the thermal head heating means.

  Further, the feeding roll 7a and the take-up roll 7b of the continuous transfer foil original fabric 7 are rotated by driving of the respective stepping motors 10 and 11, and the continuous transfer foil original fabric 7 is the thermal transfer units I, II and III of the respective colors. , Drive in IV.

  In each color thermal transfer unit I, II, III, IV, the platen 12 is rotated at a constant speed by driving a constant speed control type servo motor 22 and the continuous transfer foil original fabric 7 is moved from the upstream side to the downstream side. And send. At that time, the thermal head 13 presses the ink ribbon 14 against the continuous transfer foil original fabric 7 on the platen 12 to transfer the corresponding color ink as an image to the continuous transfer foil original fabric 7.

  When the color ink is transferred, each heating element 36 of the thermal head 13 has the print portion of the print portion before the print start end 42 of the print portion 41 of the continuous transfer foil original 7 to be printed. The non-printing portion 43 up to the printing end end 42a is energized with thermal energy that does not transfer ink.

  Further, all the platens 12 in the thermal transfer units I, II, III, and IV of the respective colors are rotated at the same constant speed under the control of the constant speed control type servo motor 22 by the control unit 17. Each color image is overprinted without shifting.

  The continuous transfer foil original fabric 7 on which an image has been formed by printing all the colors is wound as a continuous transfer foil 1 on a winding roll 7b.

  When the printing is continued, the tension of the continuous transfer foil original fabric 7 may gradually change. Therefore, the tension of the continuous transfer foil original fabric 7 is detected by the tension detector 18 during printing, and compared with the appropriate tension, a signal for eliminating the deviation is sent to the vector inverter motors 24 and 25 via a control unit (not shown). Or sent to the servo motor 23.

  The controlled driving force of the vector inverter motors 24 and 25 and the servo motor 23 is transmitted to the tension adjusting roller 19a, the feeding roll 7a, and the take-up roll 7b, so that the continuous transfer foil original fabric 7 has a constant tension. Passing through the plurality of thermal transfer units I, II, III, and IV while being maintained, a fine and beautiful image without color misregistration is printed.

  The continuous transfer foil original fabric 7 wound around the winding roll 7b is attached to a molding machine in a wound state and used as the transfer foil 1.

-Example 3-
In this embodiment, in the tandem type multi-color thermal transfer printer, the heating of the platen 12 is controlled, and the printing of the printing portion 41 to be printed on the continuous transfer foil original fabric 7 at the time of ink transfer to the printing portion 41 is started. The non-printing portion 43 from before reaching the end 42 to the printing end end 42a of the printing portion 41 is given thermal energy to the extent that ink does not transfer to reduce feed unevenness and wrinkles, and print a detailed image. It is possible.

  At the start of printing, the platen 12 is heated up to the saturation temperature during continuous printing using only the platen heating means as described above.

  Further, the feed roll 7a and the take-up roll 7b of the continuous transfer foil original fabric 7 are rotated by driving of the respective vector inverter motors 24, 25, and the continuous transfer foil original fabric 7 is transferred to the thermal transfer units I, II, Drive in III and IV.

  In each color thermal transfer unit I, II, III, IV, the platen 12 is rotated at a constant speed by driving a constant speed control type servo motor 22 and the continuous transfer foil original fabric 7 is moved from the upstream side to the downstream side. And send. At that time, the thermal head 13 presses the ink ribbon 14 against the continuous transfer foil original fabric 7 on the platen 12 to transfer the corresponding color ink as an image to the continuous transfer foil original fabric 7.

  When the color ink is transferred, each heating element 36 of the thermal head 13 has the print portion of the print portion before the print start end 42 of the print portion 41 of the continuous transfer foil original 7 to be printed. The non-printing portion 43 up to the printing end end 42a is energized with thermal energy that does not transfer ink.

  Further, all the platens 12 in the thermal transfer units I, II, III, and IV of the respective colors are rotated at the same constant speed under the control of the constant speed control type servo motor 22 by the control unit 17. Each color image is overprinted without shifting.

  The continuous transfer foil original fabric 7 on which an image has been formed by printing all the colors is wound as a continuous transfer foil 1 on a winding roll 7b.

  When the printing is continued, the tension of the continuous transfer foil original fabric 7 may gradually change. Therefore, the tension of the continuous transfer foil original fabric 7 is detected by the tension detector 18 during printing, and compared with the appropriate tension, a signal for eliminating the deviation is sent to the vector inverter motors 24 and 25 via a control unit (not shown). Or sent to the servo motor 23.

  The controlled driving force of the vector inverter motors 24 and 25 and the servo motor 23 is transmitted to the tension adjusting roller 19a, the feeding roll 7a, and the take-up roll 7b, so that the continuous transfer foil original fabric 7 has a constant tension. Passing through the plurality of thermal transfer units I, II, III, and IV while being maintained, a fine and beautiful image without color misregistration is printed.

  The continuous transfer foil original fabric 7 wound around the winding roll 7b is attached to a molding machine in a wound state and used as the transfer foil 1.

<Embodiment 2>
The second embodiment is another configuration example of the multicolor thermal transfer printer. As shown in FIG. 8, in the second embodiment, a pair of feed rollers 20a and 20b for running the continuous transfer foil original fabric 7 are provided at predetermined locations in the multicolor thermal transfer printer.

  One feed roller 20a is a roller whose surface is covered with rubber, and the other feed roller 20b is a roller whose surface is covered with metal. The roller 20b covered with rubber is driven by a servo motor 21, for example.

  The feed rollers 20a and 20b are preferably installed on the running path of the continuous transfer foil original fabric 7 at the center of the four thermal transfer units I, II, III and IV.

  The servo motors 22 directly connected to the platens 12 of all the thermal transfer units I, II, III, and IV are driven based on the rotational speeds of the feed rollers 20a and 20b driven by the servo motor 21. , II, III, and IV are controlled to rotate at the same constant speed.

  Thus, the continuous transfer foil original fabric 7 is wound around the winding roll 7b after the image is printed without causing color shift.

  In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In addition, this invention is not limited to the said embodiment, A various change is possible. For example, the present invention is not limited to a tandem-type multicolor thermal transfer printer that can transfer ink onto a continuous transfer foil original and is provided with a plurality of thermal transfer units. It may be a multicolor thermal transfer printer that is capable of transferring ink to an original made of the above and includes a thermal transfer unit.

I, II, III, IV ... thermal transfer unit 7 ... continuous transfer foil original fabric 12 ... platen 13 ... thermal head 14 ... ink ribbon 15 ... nip roller 16 ... preheating means 18 ... tension detectors 19a, 19b ... tension adjusting roller 20a, 20b ... Feed roller 22 ... Constant speed control servo motor 23 ... Servo motor

Claims (7)

A thermal transfer unit that prints an image of a plurality of color inks, supplies the original fabric to the thermal transfer unit, and the original fabric is sandwiched between a thermal head and a platen together with an ink ribbon in the thermal transfer unit, and the heating element of the thermal head In a multi-color thermal transfer printer in which images of each color ink are transferred so as to overlap each other by applying thermal energy to
Platen heating means for heating the platen;
Heating control means for controlling the heating of the platen before starting the printing of each color ink,
The heating element of the thermal head has thermal energy that does not transfer ink to the non-printing portion from before reaching the printing start end of the printing portion to be printed to the printing end end of the printing portion. A multicolor thermal transfer printer that is energized. The multicolor thermal transfer printer according to claim 1.
A multi-color thermal transfer printer, wherein a platen of the thermal transfer unit is directly connected to a rotary shaft of a constant speed control type servo motor. The multicolor thermal transfer printer according to claim 2.
In the multicolor thermal transfer printer, a plurality of thermal transfer units each printing an image of a predetermined color ink are arranged in a tandem type, and a continuous raw material is supplied to each thermal transfer unit. A multi-color thermal transfer printer that is sandwiched between a thermal head and a platen together with an ink ribbon and energizes each heating element of the thermal head so that images of the respective color inks are transferred in an overlapping manner,
The rotation axis of the servo motor with constant speed control is directly connected to the platen of the total thermal transfer unit, so that the continuous web can run at the same constant speed in the total thermal transfer unit so that the rotation of the platen is controlled. A multicolor thermal transfer printer.   4. The multicolor thermal transfer printer according to claim 3, wherein the rotational speed of the platen in the other thermal transfer unit is controlled on the basis of the rotational speed of the platen in any one thermal transfer unit. Color thermal transfer printer.   4. The multicolor thermal transfer printer according to claim 3, wherein a feed roller for running the continuous raw material is provided at a predetermined location, and the rotational speed of the platen in the thermal transfer unit is controlled based on the rotational speed of the feed roller. A multicolor thermal transfer printer characterized by the above.   4. The multicolor thermal transfer printer according to claim 3, wherein a tension detector for detecting the tension of the continuous original fabric at a predetermined position and a tension adjusting roller driven by a servo motor are provided and detected by the tension detector. A multicolor thermal transfer printer characterized in that the tension of the continuous raw fabric is adjusted by controlling the rotation speed of the servo motor based on the tension.   4. The multicolor thermal transfer printer according to claim 3, wherein a nip roller is provided for pressing the continuous raw material passing between the platen and the thermal head against the platen before and after the thermal head. Color thermal transfer printer.

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