JPH02117850A - Printing device - Google Patents

Abstract

PURPOSE:To make possible the high-quality and high-speed recording and efficient compatibility to rough paper by providing the first transfer process for transferring a negative image to a recorded image of a belt-like transport medium and the second transfer process for transferring ink to the whole recording paper from an ink sheet passing through the first transfer process. CONSTITUTION:An ink sheet 6 and a negative transfer belt 9 are transported in arrow (a, c) directions and a negative image is transferred, for recorded information, onto a negative transfer belt 9 from the ink sheet 6 by thermally controlling a thermal head 7. Next, the ink sheet 15 is transported to a whole transfer process 2 along an arrow (d), leaving ink for an image corresponding to recorded information behind. The ink sheet 15 is transported along an arrow (e) in the whole transfer process 2, then is allowed to stick to recording paper 19 closely and pressed with the help of an ultrasound head 18 and a platen 20. The ink which forms a recorded image on the ink sheet 15 generates heat due to the oscillation of the ultrasound head, and is transferred to the whole surface of the recording paper 19 to form a recorded image on the paper 19.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a printing device using a thermal transfer method.

[Prior Art] An example of a conventional thermal transfer printing apparatus will be described with reference to FIGS. 2 and 3. Figure 2 shows the thermal head 201
In this method, ink 203 activated by heat applied to an ink sheet base material 202 is selectively heated according to recorded information and simultaneously transferred onto a recording paper 205 to obtain a recorded image on the recording paper 205. . In addition, FIG. 3 shows that a conductive resistor 302 formed on an ink sheet base material 303 is selectively energized by a current supply head 301 according to recording information to heat the ink 304 activated by heat, and at the same time the recording paper is heated. In this method, the ink 304 is transferred onto the recording paper 306 to obtain a recorded image on the recording paper 306.

As mentioned above, all conventional thermal transfer printing devices use an ink sheet coated with heat-activated ink in close contact with the recording paper, and simultaneously heat the thermal transfer head selectively according to the recorded information and simultaneously perform recording. It was characterized in that a recorded image was obtained by transferring the ink onto paper.

[Problems to be Solved by the Invention] In conventional thermal transfer printing devices, when recording paper with a rough surface is used, the ink transferability deteriorates and the ink is not transferred well to the recording paper, resulting in the problem shown in FIG. 4(b). As shown, the recorded image may be missing. If the heat-generating transfer energy is increased to compensate for the decrease in transferability, heat will accumulate in the head area, preventing proper heat generation and cooling, and transfer will occur even in non-transfer areas, as shown in Figure 4 (C). Like “tailing”
It is known that this phenomenon occurs, leading to deterioration of recorded images. Furthermore, it is known that even when the transfer speed is increased in order to increase the speed of recording, the same "tailing" phenomenon as described above occurs due to the need to increase the heat generation energy. or,
When expressing gradation using a thermal transfer printing device, an area gradation method is used, which expresses gradation by changing the area of each pixel that makes up the recorded image, as shown in the example in Figure 5(a). Or, as shown in the example in Figure 5(b), a density gradation method is used in which gradation is expressed by changing the density of transferred pixels using sublimable dyes in the ink, but in either case, In order to achieve good gradation expression, it is necessary to accurately control the thermal transfer of ink, and eliminating the aforementioned heat accumulation phenomenon in the heat generating portion is an important issue. In order to solve these problems, methods have been devised and implemented, such as devising a method for controlling the energization and heating of the thermal transfer head, but their effectiveness is limited.

In other words, conventional thermal transfer printing devices have a fundamental problem in that when the transfer energy is increased in order to increase the variety of recording papers and increase the recording speed, good selective transfer is hindered by heat accumulation in the heat generating part. There is. SUMMARY OF THE INVENTION An object of the present invention is to provide a method that enables ink to be transferred onto recording paper with higher energy without damaging recorded information, and that enables higher quality and faster recording, and compatibility with rough paper. It is in.

[Means for Solving the Problems] The thermal transfer printer of the present invention includes at least an ink sheet coated with thermally activated ink and means for heating the ink and transferring it onto a recording medium. A first transfer process in which a negative transfer of the recorded image is performed onto a belt-shaped conveyance medium, and a second process in which ink is completely transferred from the ink sheet that has passed through the first transfer process onto the recording paper. It is characterized by having a transcription process.

[Example] An embodiment according to the present invention will be explained with reference to FIG.

In the apparatus shown in Fig. 1, negative transfer process 1 is the first transfer process in which a negative image is transferred to the recorded information, and full-surface transfer process 2 is the first transfer process in which the ink on the ink sheet is entirely transferred to the recording paper. This is the second transcription process.

First, the negative transfer process 1 will be explained. An ink sheet 6 coated with heat-activated ink 5 is unwound from an ink sheet unwinding wheel 3 and is pressed between a negative transfer belt 9 and a thermal head 7. A doctor blade 12 is pressed against the negative transfer belt 9,
A waste ink reservoir 13 is arranged below them. The ink sheet 6 and the negative transfer belt 9 are conveyed in the directions of arrows a and C in the figure, respectively, and at the same time the thermal head 7 is heated and a negative image is transferred from the ink sheet 6 to the recorded information. The image is transferred onto the negative transfer belt 9. After the negative transfer, the ink sheet 15 leaves an image of ink 14 corresponding to the recorded information and is conveyed to the entire surface transfer process 2 along the arrow d in the figure.

The ink 1o transferred to the negative transfer belt 9 by negative transfer with respect to recorded information is conveyed by the negative transfer belt 9 in the direction of arrow C in the figure, and is scraped onto the waste ink reservoir 13 by the doctor blade 12. be dropped. The negative transfer belt 9 whose surface has become clean is conveyed in the direction of the arrow in the figure and used again for negative transfer. In order to perform high-speed and good selective transfer, the negative transfer belt 9 is made of a hard and uniform material such as stainless steel. This is the ink 5 and the negative transfer belt 9.
At the same time, the doctor blade 1
This also has the effect of preventing the abrasion of the negative transfer belt 9 caused by No. 2.

Next, the entire surface transfer process 2 will be explained. Ultrasonic oscillator 16
generates mechanical vibrations in the ultrasonic range, and the vibrations are amplified by the ultrasonic horn 17 and guided to the tip of the ultrasonic head 18. The ink sheet 15 that has undergone the negative transfer process 1 is conveyed along the arrow e in the figure and then passed through the ultrasonic head 18.
The recording paper 19 is brought into close contact with and pressed by the platen 20.

The ink forming a recorded image on the ink sheet 15 generates heat due to the vibration of the ultrasonic head, and the ink forms a recorded image on the recording paper 19.
The image is transferred entirely onto the recording paper 19 to form a recorded image.

When we created a thermal transfer printer with the above configuration, we were able to obtain better recorded images at a much higher speed than conventional thermal transfer printers.

[Effects of the Invention] As described above, according to the present invention, uniform and good transfer conditions can be obtained in the first transfer process without being affected by the recording paper, and it is possible to drive the thermal head with low energy. In the transfer process, the ink on the ink sheet can be transferred to the recording paper with high energy, so a good recorded image can be obtained at high speed.

Furthermore, according to the present invention, by adjusting the second transfer conditions without changing the first transfer conditions, it is possible to deal with various types of recording paper without causing deterioration of the recorded image, which reduces running costs. effective.

Furthermore, by once winding up the ink sheet that has undergone the first transfer process and performing the second transfer process using a different device depending on the recording medium, it becomes possible to handle various recording media.

Furthermore, according to the present invention, since the medium to be transferred in the first transfer process is belt-shaped, the transfer distance varies depending on the belt path.
The angle and the curvature of the waste ink peeling part can be freely set, making it easier to optimize the transfer conditions compared to a method that uses a drum or the like as the transfer medium.

Furthermore, in printing devices that transfer two or more colors of ink overlappingly onto recording paper to create color expressions, according to the conventional method, the first color ink is transferred onto the recording paper, and the second and subsequent colors are transferred onto the already transferred ink. Since selective transfer is performed in a color, the transfer conditions differ depending on the color, but according to the present invention, selective transfer is performed for all colors under the same transfer conditions, making it possible to achieve better color expression.

Furthermore, according to the present invention, since no negative ink of a recorded image remains on the ink sheet after use, it is possible to maintain the confidentiality of recorded information.

Note that the same effect can be obtained even if the ultrasonic head used in the entire surface transfer process of the previous embodiment is replaced with a heater head using heat.

Further, the present invention brings similar effects not only to thermal transfer printers but also to hot stamp devices, printing devices, and the like.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a printing device according to the present invention. FIG. 2 is a diagram showing the configuration of a conventional thermal transfer printing apparatus. FIG. 3 is a diagram showing the mechanism of a printing device using a conventional current-carrying thermal transfer method. FIG. 4 is a diagram showing an example of an image recorded by a conventional thermal transfer method. FIG. 5 is a diagram showing an example of gradation expression using a conventional thermal transfer method. 1 ・ 2 ・ 4 ・ 5 ・ 6 ・ 7 ・ 9 ・ 10 ・ 12 ・ Negative transfer process Full-face transfer process Ink sheet base material Ink Ink sheet thermal Radone negative transfer belt ink (negative image) Doctor blade ink (recorded image) ・Ink sheet (after negative transfer process), ultrasonic head, recording paper, ink (recorded image) Applicant Seiko Epson Co., Ltd. Agent Patent attorney Kanzo Suzumoto and one other person 202, 203, 204, 205 Dispute 206. 1. Thermal head, ink sheet base material, ink, ink sheet, recording paper, platen Figure 2 Sheet base material, ink, ink sheet, recording paper, platen-3; (a)

Claims (1)

[Claims] At least, in a thermal transfer printer having an ink sheet coated with heat-activated ink and a means for heating the ink and transferring it onto a recording medium, a belt-shaped method is used to transfer a negative image to recorded information. A printing apparatus comprising a first transfer process performed on a conveyance medium, and a second transfer process that performs entire ink transfer from an ink sheet that has passed through the first transfer process to a recording paper.