JPH0428780Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a line head type thermal transfer recording device, in particular, it forms an endless base supporting a heat-fusible transfer material, and a method for transferring the transfer material. The present invention relates to a thermal transfer recording device in which an ink reapplying means is disposed on the downstream side of the substrate so that the substrate can be repeatedly reused.

"Prior Art and its Problems" Conventionally, an ink sheet carrying heat-fusible ink and a recording paper are pressed against the platen surface via a print head, and the platen is intermittently rotated. 2. Description of the Related Art A line head type thermal recording device is already known, in which an ink sheet and a recording paper transfer predetermined information onto the recording paper while the two move together due to the frictional force generated between the two.

In this type of recording device, during transfer, the recording paper and ink sheet are welded together via the ink, so the frictional force between them becomes extremely large, but during non-printing, the frictional force between them is This is only slightly larger than the frictional force between the head and the ink sheet.

For this reason, if a mechanism is added to the upstream side of the printing position to prevent skew or for other reasons, slipping may occur between the recording paper and the ink sheet in the non-printing area, or slippage may occur between the non-printing area and the printing There were cases where differences in the amount of transfer occurred between parts, causing wrinkles on the ink sheet.

Particularly, in a thermal transfer recording device in which the ink sheet is formed as an endless sheet as shown in the embodiments described later, and the ink sheet can be repeatedly reused, the ink sheet is located at a position facing the ink reapplying mechanism. A driving force is required to enable the platen to rotate around and return to the printing position with a predetermined tension while making a detour, and it is difficult to apply such driving force only by the frictional force generated by the rotation of the platen. If an attempt is made to obtain a predetermined driving force using only the frictional force, an unreasonable force is applied to the ink sheet, which tends to cause skew or wrinkles.

In view of the shortcomings of the prior art, the present invention provides an ink reapplying means disposed downstream of the platen roller in addition to the platen roller at the transfer position, particularly in a thermal transfer recording device that enables repeated reuse of the ink sheet. To provide a thermal transfer recording device capable of applying driving force even at a facing position, preventing occurrence of skew and wrinkles without applying excessive force to an ink sheet, and improving print quality.

"Means for Solving the Problems" The present invention forms a base supporting a heat-fusible transfer material in an endless shape, and disposes an ink reapplying means downstream of the transfer position of the transfer material. In a thermal transfer recording device that can be repeatedly reused, a detour roller that guides the endless substrate to a position facing the ink reapplying means is connected to a drive system via a friction mechanism, and the circumferential speed of the detour roller is is configured so that the peripheral speed is slightly higher than the circumferential speed of the platen roller placed at the transfer position, and the frictional force generated between the detour roller and the substrate applies forward tension to the substrate, and the rotation speed from the detour roller to the transfer position is It is characterized by a tension roller arranged on the circuit around the base body.

In addition, in order to apply frictional force to the detour roller,
For example, this can be easily achieved by forming the outer periphery of the detour roller with a rubber member, and a slipping clutch or the like can be used as the friction mechanism.

"Operation" According to this technical means, driving force is applied to the substrate at two locations: the platen roller at the transfer position and the detour roller disposed downstream thereof, so that unreasonable force is not applied to the substrate. It can be rotated without any problems.

Moreover, since forward tension is applied to the substrate via the detour roller, good printing quality can be maintained without skew or wrinkles occurring on the substrate.

Furthermore, since the present invention uses thermal transfer recording, the base welded to the recording paper side at the transfer position is pulled when peeled from the recording paper, which may cause tension fluctuations, impact vibrations, and even tensile force. However, in the present invention, a friction mechanism is interposed between the detour roller and the drive system that drives the detour roller, and the detour roller and the base body are held together through frictional force, so that fluctuations in tension and impact can be avoided. Even if a force or even a tensile force is generated, the driving force of the detour roller and the sliding friction resistance by the friction mechanism act together with the forward tension to absorb the fluctuations in the tension, etc., thereby preventing the above-mentioned defects.

Furthermore, in a preferred embodiment of the present invention, by arranging a buffer member between the detour roller and the drive system, the tensile force is further stabilized and the drive timing shift that occurs between the platen roller and the platen roller is completely eliminated. It can be prevented.

Now, with the above configuration, fluctuations in tension from the transfer position to the detour roller can be absorbed, but no consideration is given to fluctuations in tension on the substrate return side from the detour roller located downstream to the transfer position.

In particular, if forward tension is to be applied at the detour roller position as described above, sagging or vibration will inevitably occur on the downstream side. If such slack or vibration spreads to the transfer position, it becomes an obstacle to smooth transfer.

Therefore, the present invention is characterized in that a tension roller is disposed on the circumferential circuit.

Embodiments Hereinafter, preferred embodiments of the present invention will be described in detail by way of example with reference to the drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described in this example are as follows, unless otherwise specified.
This is not intended to limit the scope of this invention, but is merely an illustrative example.

1 to 3 show an ink sheet reusable thermal transfer recording apparatus according to an embodiment of the present invention.

In Fig. 3, 1 is an endless ink sheet whose surface is coated with heat-melting ink, and is made of polyimide resin or other hard and heat-resistant resin film, and is designed to improve the transfer efficiency. Therefore, the film thickness is set to be approximately 10 μm.

The ink sheet 1 is then corrected by a platen roller 2, a pair of shafts 11a and 11b arranged close to the platen roller 2, a detour roller 12 arranged facing the ink coating device 4, and a skew of the ink sheet 1. Skew correction roller 3,
The ink sheet 1 is wound around a tension roller 5 which is tension-supported by a spring 13 and applies a predetermined tension to the ink sheet 1.

The printing head 7 is disposed at a position facing the platen roller 2, and has a heating resistor element 7a arranged in a line along the width of the recording paper 6 on the side facing the platen, and a spring 14 disposed on the back side allows the ink sheet 1 and the recording The paper 6 is configured to be able to be pressed against the circumferential surface of the platen 2.

The ink coating device 4 also includes an ink tank 15 in which thermally molten ink is stored, an ink supply roller 16 disposed within the ink tank 15, and an ink tank 15 that is in contact with the ink tank 15 downstream of the supply roller 16. The correction rod 17 is arranged in such a manner that the ink sheet 1 having the missing print can be reapplied with a predetermined thickness of ink.

As a result, the platen roller 2
When the ink sheet 1 is pressed against the surface, the ink carried on the ink sheet 1 is transferred to the recording paper 6 by the selective heat generation of the heating resistor elements 71, and one line of printing is transferred. After printing, the platen roller 2 is intermittently driven by the width of one line by the step rotation of a step motor (not shown), and as a result, the ink sheet, together with the recording paper 6, is pressed against the recording paper 6 via the print head 7. 1 is also intermittently transferred due to the frictional force generated between the two.

After the ink sheet 1 with missing prints is uniformly coated again by the ink coating device 4 on the downstream side of the transfer position, the skew of the ink sheet 1 is corrected by the skew correction roller 3, and a constant tension is applied by the tension roller 5. While holding it, it returns to a predetermined position on the surface of the platen roller 2 and rotates, and the printing operation is performed again, and this process can be repeated thereafter.

Such a structure is based on the patent application filed in 1983 by the applicant.
Since it is described in No.-274453, its detailed explanation will be omitted.

Now, as mentioned above, the platen roller 2
It is difficult to obtain enough driving force to return the ink sheet 1 to a predetermined position on the surface of the platen roller 2 while bypassing the ink application device 4 using only the frictional force generated by the rotation of the platen roller 2. In the example, a drive system is attached to the shaft end of the detour roller 12 that rotates the ink sheet 1, and the detour roller 1
A tensile force is applied to the ink sheet 1 via 2.

The configuration of such a drive system will be explained based on FIGS. 1 and 2.

The detour roller 12 has an outer peripheral surface made of rubber or other high-friction material, has one shaft end extending to the outside of the side plate 21, has a flange 22 fitted to the shaft end, and has a shaft end extending outside the side plate 21. A rotating ring 23 is fitted on the outside thereof.

The rotating ring 23 has a bored hole 23a into which the flange portion 22 can be fitted, and a pressing spring 24 disposed on the back side presses the wall surface of the flange portion 22 via a sliding clutch plate 25. A pulley 26 is rotatably fitted into the outer circumferential groove 23b of the rotating ring 23, and the two 23 and 26 are connected via a spring-like thin plate spring 27 inserted in the outer circumferential recessed part 23c of the rotating ring 23.

The thin plate spring 27 rotates a predetermined number of rotations within the outer circumferential recessed portion 23c, and its both ends are connected to the pulley 26.
A predetermined buffering function is provided between the rotating ring 23 and the pulley 26 by engaging with slit grooves 23d and 26d formed on the inner periphery and the outer periphery of the rotating ring groove portion 23b, respectively.

Note that the thin plate spring 27 is not limited to any material that can provide a buffering function, and may be configured to provide a buffering function by being filled with a flexible material, for example.

The pulley 26 is connected to the timing belt 2
It is connected to a stepping motor that drives the platen roller 2 via 8, and is configured to rotate intermittently in conjunction with the platen roller 2.

In addition, the pulley 26 has a rotational speed (angular velocity) of
The diameter ratio is set so that the rotational speed of the platen roller 2 is greater than the rotational speed of the platen roller 2.

Next, the operation of this configuration will be explained.

Each time printing for one line is completed, the stepping motor is driven intermittently, the pulley 26 rotates together with the platen roller 2, and its rotational force is transmitted to the rotary wheel 23 via the thin plate spring 27.

On the other hand, the rotating wheel 23 is connected to the detour roller 12 via the sliding clutch plate 25, but as mentioned above, since the rotating wheel 23 rotates at a rotation speed higher than the rotation speed of the platen roller 2, A rotating wheel 23 that exceeds the rotational speed of the platen roller 2
The rotational force slips on the contact surface of the sliding clutch plate 25 and applies a predetermined tensile force to the detour roller 12.

At this time, even if a drive timing shift or rotational fluctuation occurs on the upstream side of the rotary wheel 23, this is absorbed by the sliding clutch plate 25, and a stable and uniform tensile force is obtained on the detour roller 12 side.

Furthermore, in this embodiment, since the thin plate spring 27 and other cushioning materials are interposed between the pulley 26- and the rotating wheel 23, vibrations on the pulley 26 side caused by the drive timing deviation etc. are absorbed, and Smooth tensile force can be applied.

"Effects of the Invention" As is clear from the above description, according to the present invention, a tensile force is applied to the substrate on the downstream side of the platen to absorb the drive timing deviation and other tension fluctuations that occur between the platen roller and the platen roller. Therefore, the relative speed between the transport speed of the recording paper and the transport speed of the sheet-like substrate can be made substantially zero, making it possible to completely prevent wrinkles on the substrate and deterioration of print quality.

It has various effects such as

[Brief explanation of the drawing]

1 to 3 show a substrate reusable thermal transfer recording device according to an embodiment of the present invention, FIG. 3 is an overall schematic diagram, FIG. 1 is a cross-sectional view of main parts, and FIG. 1
It is a sectional view taken along the line AA in the figure. 1... Base body (ink sheet), 2... Platen roller, 12... Detour roller, 25... Friction mechanism (clutch plate).

Claims (1)

[Scope of utility model registration request] A heat-sensitive transfer recording device in which a base supporting a heat-melting transfer material is formed in an endless shape, and an ink reapplying means is disposed downstream of a transfer position of the transfer material, thereby making it possible to repeatedly reuse the base, A detour roller that guides the endless substrate to a position facing the ink reapplying means is connected to a drive system via a friction mechanism, and the circumferential speed of the detour roller is adjusted to
The circumferential speed is slightly higher than that of the platen roller placed at the transfer position, and the friction force generated between the detour roller and the substrate applies forward tension to the substrate. A thermal transfer recording device characterized in that a tension roller is arranged on a circumferential circuit of a substrate.