JPH03262652A - Sublimation type thermal transfer recording method - Google Patents

Abstract

PURPOSE:To enable high density transfer recording without increasing energy to be applied to a thermal head by making faster the relative speed of movement of a transfer film with respect to the thermal head than the relative speed of movement of a recording medium with respect to the thermal head. CONSTITUTION:A transfer film 2 and a recording medium 3 are moved relative to a thermal head 1 at the time of recording; however, the relative speed V1 of the transfer film 2 with respect to the thermal head 1 is set to V1 = nV2(n>1) so as to be faster than the relative speed V2 of the recording medium 3. In this case, the greater 'n' becomes, the higher transfer density becomes. However, it is not preferable that 'n' is more than 5 because the transfer density is not increased so much in the case of 'n' being more than 5 and the consumption of the transfer film is only increased. Furthermore, in the case where 'n' becomes smaller than 1.5, the increase of the transfer density is not much obtained. Therefore, it is preferable that the range of 'n' is set to the extent of n = 1.5 - 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal transfer recording method, and particularly to a sublimation type thermal transfer recording method suitable for recording color images.

[Conventional technology]

BACKGROUND ART Sublimation thermal transfer recording has conventionally been used as a means for recording high-quality images such as photographs having a 1Wt tone.

To perform this type of thermal transfer recording, a transfer film having a sublimation dye layer is placed on a recording medium such as recording paper, moved relative to a thermal head, and the thermal head selectively heats the transfer film. 3 The dye was sublimated and transferred 0 Normally, the transfer film and the recording medium both move at the same speed relative to the thermal head.

Therefore, there was no relative movement between the transfer film and the recording medium at the position where they contacted the thermal head. In addition.

In special cases, recording is performed by running the transfer film against the thermal head at a slower speed than the recording medium.
Proposals to reduce the consumption of transfer films are known (
For example, see Japanese Patent Application Laid-Open No. 62-23788).

[Problem to be solved by the invention]

However, such conventional thermal transfer recording methods have a problem in that it is difficult to obtain images with high density.

In other words, to record a high-density image, 1. Normally, it is sufficient to increase the amount of heat applied to the transfer film by the thermal head, and it is thought that it is sufficient to increase the voltage applied to the thermal head, but the voltage applied to the thermal head If the temperature is increased, the temperature of the heat generating part of the thermal head becomes too high, causing thermal damage to the surface of the recording medium, causing problems such as loss of gloss on the surface of the recording medium and formation of a cloak.Increasing the density without increasing the applied voltage. For this purpose, it is possible to increase the application time to the thermal head, but since the maximum application time is determined according to the feeding time of one line of the recording medium,
Increasing the application time ends up increasing the feeding time for one line, resulting in a problem that the recording time becomes longer.

The present invention has been made in view of these problems.

An object of the present invention is to provide a sublimation type thermal transfer recording method capable of recording a high-density image without increasing the voltage applied to a thermal head too high or reducing the recording speed.

[Means to solve the problem]

As a result of intensive studies to solve the above problems, the inventors of the present invention found that
The present invention was achieved by discovering that recording density can be increased by increasing only the running speed of the transfer film relative to the thermal head without changing the voltage applied to the thermal head or the application time.

That is, one aspect of the present invention is a method for transferring and recording onto a recording medium by overlaying a transfer film having a sublimation dye layer on a recording medium and moving it relative to a thermal head.
The sublimation thermal transfer recording method is characterized in that the relative moving speed of the transfer film with respect to the thermal head is faster than the relative moving speed of the recording medium with respect to the thermal head.

As the transfer film used in the present invention, any conventionally known transfer film provided with a sublimation dye layer can be used as appropriate.

As the recording medium, any material such as paper, film, sheet, etc., having an image-receiving layer dyed with the dye of the transfer film can be used. It should be noted that since the transfer film and the recording medium need to slide relative to each other during recording, it is preferable that the contact surface between the two be provided with means for improving the slipperiness.

The thermal head used in the thermal transfer recording method of the present invention is
It may be a line type or a serial type. In addition, in order to perform relative movement between the thermal head, transfer film, and recording medium, the thermal head is stopped at a fixed position, and the transfer film is The recording medium may be moved, or the recording medium may be stopped and the transfer film and the thermal head may be moved.

The present invention is characterized in that the relative moving speed of the transfer film with respect to the thermal head is faster than the relative moving speed of the recording medium, and this will be explained using FIG. 1. FIG. 1 explains the relative movement of the transfer film and the recording medium with respect to the thermal head, where 1 is the thermal head, 2 is the transfer film, 2a is the sublimation dye layer of the transfer film, 3 is the recording medium, 3a is its image-receiving layer. At the time of recording.

The transfer film 2 and the recording medium 3 move relative to the thermal head l, but in the present invention, the thermal head l
The relative speed V of the transfer film 2 with respect to is the relative speed V of the recording medium 3! ie.

Set V, -nV, (n>1). Here, as n in the above equation increases, the transfer density increases, but if it is thicker than 5, the transfer density will not increase too much (, and only the consumption of the transfer film will increase, so it is not preferable (, n When is smaller than 1.5, the increase in transfer density cannot be obtained much. Therefore, the range of n in the above formula is preferably set to about 1.5 to 5.

[Effect]

In FIG. 1, when a voltage is applied to the thermal head 1, the heat generating part 1a generates heat and heats the transfer film 2, sublimating the dye in the sublimation dye layer 2a and transferring it to the image receiving layer 3a of the recording medium 3. Image recording is performed by transferring.

At this time, assuming that the transfer is performed on the length of the recording medium by one application to the thermal head 1,
At this time, the transfer film 2 moves by a length Ll (=nLi, and the dye in the area indicated by the diagonal &!2b is transferred to the recording medium 3 as indicated by the diagonal line 3b.On the other hand, as shown in FIG. , when the transfer film 2 is moved at the same speed v2 as the recording medium 3, the dye in the portion indicated by the diagonal line 2b' within the length Ll of the transfer film 2 is transferred to the recording medium 3 as indicated by the diagonal line !3b'. Here, the thermal head l
Assuming that the same voltage is applied for the same amount of time in both the cases of FIG. 1 and FIG. 2, the thermal head l applies the same amount of heat to the transfer film 2, but
Since a longer area of the dye layer of the transfer film is used for transfer than in the case shown in the figure, the dye on the surface area that is easy to transfer is transferred quickly, and the amount of transferred dye in the case shown in Fig. 1 is higher than that shown in Fig. 2. is larger than in the case of .

This enables high-density transfer recording without increasing the amount of heat used to heat the transfer film by the thermal head.

〔Example〕

FIG. 3 is a schematic side view of one embodiment of a recording device used to carry out the method of the present invention, in which 1 is a thermal head, 2 is a transfer film, 2A is a supply reel for feeding out new transfer film 2, and 2B is a used reel. A take-up reel for winding up the finished transfer film 2, and 3 a recording medium made of recording paper.

4 is a feed roller that conveys the transfer film 2, 5 is a platen roller that holds the recording medium 3, and 6 is a thermal head 1.
This is a pressure spring that presses the platen roller. The feed roller 4 and the platen roller 5 move the transfer film 2 and the recording medium 3 at speeds Vl and vt, respectively.

It is configured to be driven so that it can be conveyed at Vl==nvg). Thus, with this recording apparatus, it is possible to transfer and record onto the recording medium 3 while running the transfer film 2 on the thermal pad 1 at a faster speed than the recording medium 3.

Transfer recording is performed under various conditions using this recording device,
The reflection density (0, D) of the obtained image was measured. The conditions and results are shown below.

(1) Example 1 Feeding speed of recording medium 33.3m5ec/1ine
Feeding speed of transfer film 16.6 Speed ratio (n) 2.0 Pulse width applied to thermal hend 16 s+sec/1ine Applied voltage 8.0■ Recorded image 0. [) 2.0 (2) Example 2 Feeding speed of recording medium 33.3 m5ec/1in
eTransfer film feeding speed 22,2 ~ speed ratio (n)
1.5 Pulse width applied to thermal head 16 asec/1ine Applied voltage 9.5v Recorded image 0. D 2.2 (3) Comparative Example 1 Feeding speed of recording medium 33.35sec/1tne
Feeding speed of transfer film 33.3 #Speed ratio (n
)1 Applied pulse width to the thermal head 16 m5ec/1ine Applied voltage 11. OV Recorded image 0. D 2.0 (4) Comparative Example 2 Feeding speed of recording medium 33.3 m5ec/1in
eTransfer film feeding speed 33.3 Speed ratio (n) 1 Applied pulse width to thermal head 16 m5ec/1ine Applied voltage 8.0■ Recorded image 0. D 1.1 As is clear from this result, the speed ratio (n) of the transfer film 2 to the recording medium was 1.5 (Example 2), 2°0
(Example 1), it is possible to obtain an image with a reflection intensity of 2 or more while setting the applied voltage to the thermal head low, but if the transfer film and the recording medium are moved at the same speed, In order to achieve a reflection intensity of 2 or more, the applied voltage had to be set to IIV. Also.

The image recorded with an applied voltage of 11 V had a reflectance of 2, but was not glossy.

Furthermore, using the recording device shown in Figure 1, the feeding speed of the recording medium was increased to 3.
3.3 +*sec/1ine, and the pulse width and voltage applied to the thermal head are each 16m5ec.
/1ine and 8°0■, recording was performed while changing the speed ratio (n), and the reflection density of the obtained image was measured to obtain the graph shown in FIG.

As is clear from this graph, the reflection density can be increased as the speed ratio n increases.

〔Effect of the invention〕

As is clear from the above description, one method of the present invention is as follows.

By making the relative movement speed of the transfer film to the thermal head faster than the relative movement speed of the recording medium to the thermal head, high-density transfer recording is possible without increasing the energy applied to the thermal head. This has the effect of making it possible to obtain a high-density recorded image while preventing matting of the image.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view for explaining the recording principle according to the present invention, FIG. 2 is a cross-sectional view for explaining the recording principle according to the conventional method, and FIG. 3 is a cross-sectional view for explaining the recording principle according to the conventional method. A schematic side view showing one example, and FIG. 4 is a graph showing the measurement results of the reflection density of an image recorded using the recording apparatus of FIG. 3. 1.-Thermal head 52.--Transfer film, 2
a--Jil-flower dye layer, 3--recording medium, 3a image-receiving layer, 4--feeding roller, 5--platen roller.

Claims (1)

[Claims] In a method in which a transfer film having a sublimation dye layer is superimposed on a recording medium and moved relative to a thermal head to perform transfer recording on the recording medium, the relative moving speed of the transfer film with respect to the thermal head is A sublimation thermal transfer recording method characterized in that the relative moving speed of the recording medium to the thermal head is faster.