JPS63276586A - Thermal transfer recorder - Google Patents

Abstract

PURPOSE:To achieve improvement of ink transferring property, i.e. stability of recording density and image quality by keeping tension at a sheet peeling position of a thermal transfer sheet at an optimum value, by a method wherein a tension detection part of the thermal transfer sheet is provided between the sheet peeling position and a sheet winding reel and a torque of the sheet winding reel is controlled by its detection quantity. CONSTITUTION:A thermal transfer sheet 2 is pressurized with a thermal head 3 and a platen roller 4 in a state where they are piled up, and transfer recording is carried out. Thereafter, image receiving paper 1 is conveyed at a constant speed with a paper feed roller 8. The thermal transfer sheet 2 is peeled off from the image receiving paper 1 at a peeling position 10 of a peeling roller 7, and wound in an arrow (a) direction on a winding reel 6 via a tension detection part 11. The tension detection part 11 generates voltage output corresponding to deformed amount of a component generated by a force received from a sheet wound on the tension detection part 11. A winding torque of the winding reel 6 is so controlled as to become output voltage corresponding to sheet tension optimum for peeling of the sheet, and the sheet tension is always kept constant.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal transfer recording device useful as a hard copy device for outputting a single character image for televisions, computers, etc.

2. Description of the Related Art A schematic diagram of a conventional thermal transfer recording apparatus is shown in FIG. The thermal transfer sheet 2 coated with thermal transfer ink is wound around a supply reel 5, and while being unwound from the supply reel 5, it is overlapped with the image receiving paper 1 and is pressed into contact with a line-type thermal head 3 and a platen roller 4. , recording is performed by selective heating from the thermal head 3. Thereafter, the thermal transfer sheet 2 and the image receiving paper 1 are separated at the position of the peeling roller 7, and the image receiving paper 1 is separated from the paper feeding roller 8 and the paper pressing roller 9.
The thermal transfer sheet 2 is taken up on a take-up reel 6 in the direction of arrow a.

To 3-7 Here, the image receiving paper 1 is transported at a constant speed by the paper feed roller 8 driven at a constant speed in the direction of the arrow. Since the sheet is in close contact with the image-receiving paper 1 up to the peeling position 10 around the area, the sheet is conveyed together with the image-receiving paper 1, and after passing the peeling position 10, the sheet is conveyed by the torque of the take-up reel 6 and is wound up. Here, if the peeling conditions between the thermal transfer sheet 2 and the image-receiving paper 1 change, the ink transferability changes, causing a difference in the density and quality of the recorded image. Therefore, JP-A-61-682
As in Japanese Patent No. 79, there is an idea to adjust and control the peeling conditions. The peeling conditions here include the peeling angle,
It shows the peeling speed and peeling time. By optimizing these conditions according to the transfer ink or transfer color order,
Improves ink transfer properties.

Problems to be Solved by the Invention In the conventional thermal transfer recording device, the sheet peeling position 10
The tension of the sheet was given by the rotational torque of the take-up reel 6.

Since the take-up reel 6 substantially increases in diameter as the amount of sheet taken up increases, the tension in the sheet decreases as the diameter increases when rotated with a constant torque. When the amount of change is large, it ranges from % to %. Also,
If the sheet tension between the sheet peeling position 10 and the take-up reel 6 is too large, the conveyance force of the image receiving paper 1 will be increased more than necessary in the portion that is in close contact with the image receiving paper 1, and the paper feed roller Although the image-receiving paper 1 is being conveyed at a constant speed in step 8, the image-receiving paper 1 is fed at a speed higher than the feeding speed of the paper feed roller 8 at the pressure contact portion with the thermal head 3. In this case, the recorded image will be misaligned and paper jams will occur. Moreover, excessive seat tension may cause damage to the seat. Therefore, the winding tension of the winding reel 6 cannot be made strong at the beginning of winding, and at the end of winding, the tension becomes about % to % of the same.

Depending on the combination of the thermal transfer sheet 2 and the image receiving paper 1, some types require a certain degree of sheet peeling force after recording (5/, -7). In that case, if the sheet tension at the sheet peeling position 1o is insufficient, the sheet will not be completely peeled off at the sheet peeling position 10, but will peel off at another position. Therefore, the peeling conditions change and the ink transfer properties change. Therefore, differences occur in the density and image quality of recorded images. Also, thermal transfer sheet 2
If the paper reaches the paper feed roller 8 without being peeled off, a paper jam occurs.

Therefore, it was necessary to maintain the sheet tension at the sheet peeling position 10 at an optimal value, but this was very difficult with the conventional configuration.

Means for Solving the Problems In order to solve the above problems, the present invention provides a tension detection section for detecting the tension of the thermal transfer sheet between the sheet peeling position and the sheet take-up reel, and uses the detected amount to detect the tension of the sheet. Controls the torque of the take-up reel.

Operation The present invention has the above-described structure, maintains the tension at the sheet peeling position of the thermal transfer sheet at an optimum value, and constantly optimizes the sheet peeling conditions to improve the transferability of the ink 6, that is, the recording density, and the image quality. Accordingly, it is possible to obtain a recording apparatus in which the stability of the image receiving paper and the thermal transfer sheet are improved, and the reliability of conveyance of the image receiving paper and the thermal transfer sheet is improved.

Embodiment Hereinafter, the configuration of an embodiment of the present invention will be explained based on the accompanying drawings.

FIG. 1 is a basic configuration diagram showing a recording apparatus in an embodiment of the present invention, in which 1 is an image receiving paper, 2 is a thermal transfer sheet, 3 is a thermal head in which a plurality of heating elements are arranged linearly, and 4
5 is a platen roller, 5 is a supply reel for the thermal transfer sheet 2,
Reference numeral 6 indicates a take-up reel, and reference numeral 6 indicates a peeling roller that determines a peeling position 10 between the thermal transfer sheet 2 and the image receiving paper 1. Reference numeral 8.9 denotes a paper feed roller and a paper press roller for conveying the image receiving paper 1 at a constant speed.

The thermal transfer sheet 2 is overlapped with the image receiving paper 1 and is pressed against the thermal head 3 and the platen roller 4 to perform transfer recording. Thereafter, the image receiving paper 1 is conveyed at a constant speed by the paper feed roller 8, and the thermal transfer sheet 2 is peeled off from the image receiving paper 1 at the peeling position 1o of the peeling roller 7, . It is wound onto the reel 6 in the direction of arrow a.

If the tension of the sheet between the sheet peeling position 1o and the take-up reel 6 is T, then a force of 2 T sin θ is applied to the tension detection section 11 in the direction of arrow C. The tension detection section 11 is configured to measure the deformation of the member using a strain gauge, and generates a voltage output corresponding to the amount of deformation of the member caused by the force received from the sheet wrapped around the tension detection section 11. Therefore, an output V corresponding to 2 T sin θ is generated.

Now, if the optimal sheet tension for sheet peeling is T1, then the force applied to the tension detection section 11 is 2T, sin θ
, and a corresponding output of vl will be generated. Therefore, by controlling the winding torque of the take-up reel 6 and changing the sheet tension so that V2V, the sheet tension can always be maintained at T==T,K. Torque of the take-up reel 6 is provided by a reel drive motor and an electromagnetic clutch (not shown), and is configured to generate torque in response to the signal V output from the tension detection section 11 described above. For example, when the sheet tension T is weaker than the optimum value and T(T), the output of the sheet detection section 11 becomes V < V. Then, the torque of the take-up reel 6 is strengthened by the electromagnetic clutch, and the sheet tension T increases.゛In this way, the seat tension T is always T:
= 'r.

FIG. 2 is a basic configuration diagram showing a recording apparatus in another embodiment of the present invention. The tension roller 12 is fixed to a tension roller support plate 13 and biased by a spring 14 in the direction of arrow d. Let that power be T2. Now, assuming that the tension of the sheet is T, a force of 2 T sin θ is applied to the tension roller 12 in the direction of arrow C, as in FIG. 2T at optimal seat tension T1
, 5Lrlθ≧T2. Therefore, for example, when the sheet tension is weaker than the optimum value and T(T), if 2Tsinθ<T2, the tension roller 1
2 and the tension roller support plate 13 are rotated 9 in the direction of arrow d.
When Heno moves, it is detected by the switch 15. Then, the torque of the take-up reel 6 increases, the sheet tension T increases, the tension roller 12 rotates in the direction of arrow C, and the switch 1
The torque is fixed at the point where 6 is cut off. At that time, the sheet tension T given by the take-up reel 6 is T≧T. With this configuration, it is difficult to maintain the seat tension at a constant value, but it is possible to maintain it above a constant value. Therefore, the initial winding torque should always be set to low H, and the torque should be increased according to the tension at that time. In this case, the configuration is simpler than the embodiment shown in FIG.

In the embodiment, the torque of the take-up reel 6 is controlled by an electromagnetic clutch, but other methods may be used, such as controlling the torque by changing the frictional force of the sliding surface, for example.

Further, in the embodiment, the sheet peeling position 10 is located around the peeling roller 7, but the peeling position may be located at the end of the thermal head 3, excluding the peeling roller 7, or other peeling members may be used. Go to 10.-] Yes. In addition, although the thermal head 3 is of a line type with a plurality of heating elements arranged side by side, it may also consist of a single heating element.Also, in the case of an electrically conductive thermal transfer method in which the thermal transfer sheet itself generates heat, the thermal head 3 may be a line type in which a plurality of heating elements are arranged side by side. A current-carrying head may be used instead of the thermal head, and thermal transfer recording may be performed using a laser beam or the like.

Further, although the image-receiving paper is transported at a constant speed by the paper feed roller, a method may also be adopted in which the platen roller is rotated at a constant speed to convey the image-receiving paper, and the paper feed roller sends out the image-receiving paper at a constant tension.

Effects of the Invention The present invention maintains the tension at the sheet peeling position of the thermal transfer sheet at an optimum value and always optimizes the sheet peeling conditions to improve ink transferability, that is, stability of recording density and image quality, and to improve the stability of image transfer and image reception. A recording device with improved reliability in conveying paper and thermal transfer sheets can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a schematic configuration of a recording device according to an embodiment of the present invention, FIG. 2 is a side view showing a schematic configuration of a recording device according to another embodiment of the present invention, and FIG. The figure is a side view showing a schematic configuration of a conventional recording device. 1...Image receiving paper, 2...Thermal transfer sheet, 3
...Thermal head, 6... Winding reel, 7.
...Peeling roller, 11...Tension detection section. Name of agent: Patent attorney Toshio Nakao and 1 other person1-
Female image weight 2 - Thermal transfer sheet 5 - Supply sole O - Take-up roller 9 - Paper press roller 10 - Sheet j'7 m1 position 12 - Tension roller

Claims (3)

[Claims] (1) A recording unit that presses the thermal transfer sheet and image-receiving paper to perform thermal transfer recording, a means for conveying the image-receiving paper, a take-up reel that peels the thermal transfer sheet from the image-receiving paper and winds it, and regulates the peeling position of the thermal transfer sheet. In a thermal transfer recording device having means, a tension detection section for detecting the tension of the thermal transfer sheet is provided between the sheet peeling position and the sheet take-up reel, and a torque control means is provided for controlling the torque of the sheet take-up reel based on the detected amount. A thermal transfer recording device characterized by: (2) The thermal transfer recording device according to claim 1, wherein the tension detection section is constituted by a strain gauge that is in sliding contact with the thermal transfer sheet and detects the amount of deformation due to the tension of the thermal transfer sheet. (3) a tension roller in which the tension detection section slides into contact with the thermal transfer sheet and holds the thermal transfer sheet at a constant pressure;
The thermal transfer recording device according to claim 1, comprising a switch that opens and closes by movement of a tension roller.