JP2868374B2 - Driving method of thermal transfer printer - Google Patents

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 for printing by transferring ink on an ink ribbon to paper by the heat of a thermal head, and in particular, transferring the ink on an ink ribbon to an intermediate transfer member by a thermal head. More particularly, the present invention relates to an intermediate transfer type thermal transfer printer for performing desired printing by forming a primary recording image on a sheet and retransferring the primary recording image to paper, and particularly to a driving method thereof.

[0002]

2. Description of the Related Art Conventionally, a thermal transfer printer which performs printing in a state where a thermal head is pressed against a platen via a sheet and an ink ribbon is often used. When printing on paper having a rough surface, it is necessary to press the thermal head with a strong pressing force, but the pressing force of the thermal head is limited due to its precise structure. Therefore, a primary recording image is formed on the intermediate transfer body by partially melting the ink of the ink ribbon by the heat generated by the thermal head and transferring the ink to the intermediate transfer body. 2. Description of the Related Art An intermediate transfer type thermal transfer printer is used in which an intermediate transfer member is transferred to a sheet by a pressure roller that presses the intermediate transfer member against the sheet with a pressing force.

FIG. 3 schematically shows such a conventional intermediate transfer type thermal transfer printer.
A cylindrical intermediate transfer roller 1 constituting an intermediate transfer member is rotatably disposed. Inside the intermediate transfer roller 1, a heater 2 for heating the intermediate transfer roller 1 to a predetermined temperature is provided. Built-in. In the vicinity of the intermediate transfer roller 1, a thermal head 3 is provided. The thermal head 3 has a plurality of heating elements 4 arranged in a straight line and arranged so as to face the center of the intermediate transfer roller 1. On both sides of the thermal head 3, ink is applied to a bobbin 5. A pair of ribbon rolls 7 for winding the ribbon 6 and guiding the ink ribbon 6 substantially linearly between the intermediate transfer roller 1 and the thermal head 3
A and 7B are provided. Of these, ribbon roll 7
A is on the supply side, and the ribbon roll 7B is on the winding side. Further, a pressure roller 8 that is pressed against the intermediate transfer roller 1 with a strong pressing force is rotatably disposed at a position diametrically symmetric with respect to the thermal head 3 of the intermediate transfer roller 1. A predetermined sheet 9 such as plain paper is inserted between the intermediate transfer roller 1 and the pressure roller 8, and the intermediate transfer roller 1 is driven to rotate, thereby transferring the sheet 9 to the intermediate transfer roller 1 and the pressure roller 8. And transported in the direction opposite to the running direction of the ink ribbon 6.

According to the above-described conventional thermal transfer printer,
A sheet 9 between the intermediate transfer roller 1 and the pressure roller 8
Is inserted, the pressure roller 8 is pressed against the intermediate transfer roller 1 with a strong pressing force, and the thermal head 3 is pressed against the intermediate transfer roller 1. In this state, the intermediate transfer roller 1 is driven to rotate, and 9 and the ribbon roll 7 on the winding side.
While the ink ribbon 6 is wound at a predetermined speed by B, the thermal head 3 is driven based on desired print data. As a result, the heating element 4 of the thermal head 3 generates heat and the ink of the ink ribbon 6 is partially melted and transferred to the surface of the intermediate transfer roller 1 to form a primary recording image. At this time, the primary recording image formed on the surface of the intermediate transfer roller 1 only needs to be held on the intermediate transfer roller 1, and since the surface of the intermediate transfer roller is smooth, the thermal head 3 is moved to the intermediate transfer roller 1. It is not necessary to make the pressure contact with a strong pressure.

The heater 2 of the intermediate transfer roller 1
In a state where the ink transferred to the intermediate transfer roller 1 is heated to a constant temperature to generate a certain degree of viscosity in the ink, the primary recording image of the intermediate transfer roller 1 is applied to the paper 9 by the pressing force of the pressure roller 8. The desired printing can be performed on the paper 9 by retransfer. As a result, the image is retransferred onto the paper 9 by the pressure roller 8 with a strong pressing force, so that printing can be performed even on paper 9 having a rough surface such as bond paper.

[0006]

In the intermediate transfer type thermal transfer printer having the above-described structure, the heating element 4 of the thermal head 3 generates heat so that the ink on the ink ribbon 6 is partially melted. The separation of the ink ribbon 6 from the intermediate transfer roller 1 at the time of forming the primary recording image by being transferred to the surface of the heating element 1 has been performed after the ink melted by the heat generated by the heating element 4 is cooled. Peeling of the ink ribbon at such a timing is referred to as cold peeling, and is a peeling method that counteracts hot peeling in which the ink is still in a molten state.

[0007] When the ink ribbon 6 is peeled off at a cold time, a wax-based ink is used to improve the printing quality. However, since this wax-based ink does not form a film even when it is melted by the heat generated by the heating element 4, it is possible to perform good quality printing on the paper 9 having a rough surface due to generation of voids. Did not. Further, there is a possibility that ink remains on the intermediate transfer roller 1.

For this reason, the paper 9 having a rough surface
It has been found that, in order to uniformly apply the ink on the ink, the ink itself needs to be a resin-based ink capable of forming a film state by the heat generated by the heating element of the thermal head.

Due to its characteristics, the resin-based ink is transferred to the print medium (intermediate transfer roller 1) only when the ink of the ink ribbon 6 is melted by the heat energy generated from the heating element 4 of the thermal head 3. Is possible. On the other hand, according to the experiments performed so far, the time during which the ink is maintained in the molten state is as short as 5 msec from the time when the heat energy from the heating element 4 is obtained. However, it has been difficult to perform hot peeling with an ink ribbon having a resin-based ink.

In addition, it is necessary to heat the intermediate transfer roller 1 for hot separation, but it has been difficult to heat the outer peripheral surface of the intermediate transfer roller 1 to a uniform temperature.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to drive a thermal transfer printer capable of uniformly heating an intermediate transfer body in an intermediate transfer system and performing printing of good quality on paper having a rough surface. The aim is to provide a method.

[0012]

According to the present invention, there is provided a method for driving a thermal transfer printer, comprising: a thermal head for partially melting ink on an ink ribbon in accordance with print data; An ink ribbon is interposed between the intermediate transfer member and a pressure roller that is pressed against the intermediate transfer member is provided, and the thermal head and the pressure roller can be freely moved toward and away from the intermediate transfer member. In the thermal transfer printer, the thermal head and the pressure roller are each separated from the intermediate transfer member when the intermediate transfer member is preheated by the heating means before printing, so that the intermediate transfer member runs idle.

[0013]

According to the present invention, when the intermediate transfer body is preheated by the heating means, the intermediate transfer body is preheated while idling, so that the intermediate transfer body is heated to a uniform temperature in the circumferential direction. Accordingly, the hot-peeling can be performed using the resin-based ink, so that printing of good quality can be performed by uniformly adhering the ink on paper having a rough surface.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. Note that the same or corresponding components as those of the above-described conventional device are denoted by the same reference numerals in the drawings, and description thereof will be omitted.

FIGS. 1 and 2 show an embodiment of a thermal transfer printer for implementing the driving method of the present invention.
As shown in detail in FIG. 2, the thermal head 3 in this embodiment has a flat insulating substrate 10 formed of a material such as ceramic. This insulating substrate 10
A glaze layer 11 made of a material such as glass and having a heat storage function is stacked on one end of the glass layer. The upper surface of the glaze layer 11 is formed in an arc shape so that the top extends in the direction in which the heating elements 4 are arranged. This glaze layer 11
A plurality of heating elements 4 are linearly arranged on the top of the. Further, a common electrode (not shown) and an individual electrode (not shown) for supplying power to the heating elements 4 are connected to each heating element 4. In this embodiment, the common electrodes are connected from the end of the insulating substrate 10. It is connected to each heating element 4.

The length of the common electrode from the end face 12 of the insulating substrate 10 to each heating element 4 is set to 0.9 mm or less. This dimension is extremely small as compared with the conventional thermal head. As a result, the thermal head 3 of this embodiment has a so-called real edge in which each heating element 4 is located near the end face 12 of the insulating substrate 10. It is of type.

The thermal head 3 of the present embodiment having the above-described configuration is disposed such that the end face 12 of the insulating substrate 10 is located downstream of the heating element 4 in the running direction of the ink ribbon 6. In addition, the heating element 4 is movably disposed so as to be able to contact and separate from the intermediate transfer roller 1.

Further, a pinch roller for peeling off the ink ribbon 6 at a portion passing through the heating element 4 from the intermediate transfer roller 1 immediately downstream of the thermal head 3 in the running direction of the ink ribbon 6. 13 is rotatably disposed on the longitudinal extension of the insulating substrate 10 of the thermal head 3, and moves the ink ribbon 6 along the outer peripheral surface of the pinch roller 13 on the side away from the intermediate transfer roller 1. By causing the ink ribbon 6 to pass, the portion of the ink ribbon 6 that has passed the heating element 4 can be immediately separated from the intermediate transfer roller 1.

Further, the pressure roller 8 which is in pressure contact with the intermediate transfer roller 1 is movably disposed so as to be able to contact and separate from the intermediate transfer roller 1.

Further, the heater 2 provided in the intermediate transfer roller 1 is constituted by a halogen lamp as an example so as to uniformly heat the intermediate transfer roller 1 in its axial direction.

The other structure is the same as that of the above-mentioned conventional one.

Next, the operation of the present embodiment having the above-described configuration will be described.

When the main switch of the thermal transfer printer is turned on for printing, in this state, the thermal head 3 and the pressure roller 8 are separated from the intermediate transfer roller 1 as shown in FIG. In this case, the heater 2 serving as a heating unit is turned on to preheat the intermediate transfer roller 1, and at this time, the intermediate transfer roller 1 is idled by driving of a driving unit (not shown). It is uniformly heated in the circumferential direction. The pre-heating of the intermediate transfer roller 1 is performed at a temperature of about 50 ° C. to 63 ° C. at which the outer peripheral surface of the intermediate transfer roller 1 can be maintained in a molten state of the ink in order to perform the hot peeling of the ink ribbon 6. That is, it is necessary to heat the ink to a temperature higher than the ambient temperature and lower than the melting point of the ink.

When the intermediate transfer roller 1 is preheated for a certain period of time as described above, a printable state is obtained. Therefore, when the paper 9 is inserted between the intermediate transfer roller 1 and the pressure roller 8, the intermediate transfer roller 1
After pressing the thermal roller 3 against the intermediate transfer roller 1 and pressing the thermal head 3 against the intermediate transfer roller 1, the intermediate transfer roller 1 is rotated to convey the paper 9, and the ink ribbon is moved by the take-up ribbon roll 7 B. While winding 6 at a predetermined speed, the thermal head 3 is driven based on desired print data. As a result, each heating element 4 of the thermal head 3 selectively generates heat, and the ink of the ink ribbon 6 is partially melted and transferred to the surface of the intermediate transfer roller 1 to form a primary recording image.

Incidentally, the ink of the ink ribbon 6 in this embodiment is of a resin type suitable for peeling at the time of heating, while the thermal head 3 in this embodiment is of a real edge type, and As a result, the portion of the ink ribbon 6 that has passed through the heating element 4 is immediately peeled off from the intermediate transfer roller 1 and the intermediate transfer roller 1 is also heated by the heater 2 provided inside. The ink on the ink ribbon 6 at the portion that has been melted by the heat is transferred to the intermediate transfer roller 1 while it is still in the melted state. Therefore, the ink of the ink ribbon 6 is transferred to the intermediate transfer roller 1 when it is in a film state by melting, and the primary recording image on the intermediate transfer roller 1 has the ink of the ink ribbon 6 uniformly attached thereto. It is of good quality.

Next, the heater 2 of the intermediate transfer roller 1
In a state where the ink transferred to the intermediate transfer roller 1 is heated to be in a semi-molten state and the ink is formed into a film to generate a certain degree of viscosity, the pressure of the pressure roller 8 causes the primary transfer of the intermediate transfer roller 1 The recorded image is retransferred to the paper 9 and desired printing is performed on the paper 9. At this time, since the ink of the primary recording image is in a film state, the ink on the paper 9 also adheres uniformly. Good quality can be obtained. As described above, in the present embodiment, the transfer is performed when the ink is in the form of a film due to heat using the resin-based ink, so that printing of good quality can always be performed. Further, since the preheating is performed while the intermediate transfer roller 1 is idling, the preheating time of the intermediate transfer roller 1 can be shortened.

The present invention is not limited to the above-described embodiment, but can be variously modified as needed. For example, in the above-described embodiment, the intermediate transfer roller is used as the intermediate transfer member, but a belt or the like may be used as the intermediate transfer member.

[0028]

As described above, according to the driving method of the thermal transfer printer of the present invention, the intermediate transfer body can be preheated stably and the transfer can be performed when the ink is in the form of a film due to the heat. Therefore, it is possible to achieve an effect that printing of good quality can be performed even on paper having a rough surface.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a thermal transfer printer that performs a driving method of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1 showing a state of the intermediate transfer roller during preheating.

FIG. 3 is a schematic configuration diagram showing a conventional thermal transfer printer.

[Explanation of symbols]

 Reference Signs List 1 intermediate transfer roller 2 heater 3 thermal head 4 heating element 6 ink ribbon 8 pressure roller 9 paper 10 insulating substrate 11 glaze layer 12 end surface of insulating substrate 13 pinch roller

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-182166 (JP, A) JP-A-3-227254 (JP, A) JP-A-3-242667 (JP, A) JP-A-5-205 293998 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/325 B41J 29/00

Claims (1)

(57) [Claims] An ink ribbon is interposed between a thermal head that partially melts the ink of an ink ribbon in accordance with print data and an intermediate transfer member that is heated by a heating unit, and is pressed against the intermediate transfer member. A pressure transfer roller is provided, and the thermal head and the pressure roller can be freely moved toward and away from the intermediate transfer member, respectively. A method for driving a thermal transfer printer, characterized in that the pressure rollers are respectively separated from the intermediate transfer member so that the intermediate transfer member runs idle.