JPH04201574A - Thermal transfer printer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal transfer printer used as an output terminal for various computers including CAD-CAM.

Conventional technology In recent years, thermal printers have not only been able to print on thermal paper, which is often used for facsimiles, but also thermal transfer monochrome printing using monochrome ink film and thermal transfer paper, and even color ink film with multicolor plane sequential printing. Applications are increasing for thermal transfer color printing, etc.

Recently, thermal transfer color printers have been used in applications ranging from the traditional CAD/CAM field to business graphics using personal computers, desktop publishing that requires both character quality and image quality, and bripress and proofing where even higher image quality is desired. In order to express true blacks and grays and to require high color reproducibility, the conventional three-color overlay printing using yellow, magenta, and cyan inks has been changed to yellow, magenta, and cyan. It has become necessary to perform four-color overlapping printing using four-color ink including cyan and black.

In four-color printing using conventional thermal transfer printers, black printing was performed after the conventional yellow, magenta, and cyan printing due to the inking method of printing technology.

Problems to be Solved by the Invention However, due to the printing principle of thermal transfer color printers,
Because color printing is performed by overlapping ink layers, the fixation of the ink deteriorates as the ink is placed on top of the ink, yellow, yellow, etc.
When printing in four colors (magenta, cyan, and black), the black ink that is printed at the end has poor adhesion. In particular, when black is printed in an area adjacent to an area where yellow, magenta, and cyan are overlaid and printed, a white spot of about 1 dot occurs. Since black printing mainly consists of characters and line drawings, poor black print fixation in areas adjacent to yellow, magenta, and cyan overlapping printed areas will significantly degrade print quality. Furthermore, inking methods using black ink, which aim for high color reproducibility, cannot achieve sufficient color reproduction with four colors due to the unstable fixation of the black ink.

The present invention solves this problem by printing black as the first color instead of the conventional four-color printing of yellow, magenta, cyan, and black.
The purpose of this invention is to provide a high quality thermal transfer printer that has high color reproducibility, including black and gray, by printing in magenta and cyan in that order.

Means for Solving the Problem In order to solve this problem, the present invention includes a platen roller that conveys paper, a thermal head provided opposite to this platen roller, and a thermal head that applies heat from this thermal head and that prints yellow paper. , magenta, cyan, black 4
It has a four-color surface sequential ink film composed of different colors, and is configured to thermally transfer the printing of the first color from black ink to the paper.

Function: With this configuration, it is possible to provide a thermal transfer printer with high print quality and high color reproducibility including black and gray.

Embodiment FIG. 1 is an overall perspective view of a thermal transfer color printer according to an embodiment of the present invention. In the figure, 1 is a lower cabinet, 2 is a circuit section, and 3 is a power supply panel. A pinch roller 4 contacts the capstan roller 5 and applies a driving force. 6. is a platen roller, which together with a pinch roller 4 and a capstan roller 5 constitutes a paper feeding mechanism. Here, the pinch roller 4 and the platen roller 6 are driven by a main motor 7. 8 is linked to the operation of the cam,
This is a pinch roller lever that brings the pinch roller 4 into contact with the capstan roller 5 and releases the contact. 9 is a peeling roller that separates the ink film from the paper; 10 is a paper feed roller that brings the paper into contact with the platen roller 6; and 11 is a paper guide that guides the paper.

Reference numeral 12 denotes a paper support for storing paper wound into a roll. Reference numeral 13 denotes a cover frame, which is opened and closed by engaging and disengaging the lock lever 14 and the lock lever shaft 15. A ribbon feed gear 16 for positioning one end of a ribbon feed formed by winding an ink film into a roll, and a ribbon feed presser 17 for applying a pressing force to the other end of the ribbon feed are arranged on the cover frame 13. Reference numeral 18 denotes a head hold, to which a thermal head 19 is fixed, and is fixed to a head arm 20 that is linked to the operation of a cam. 21 is a cooling fan that radiates heat from the main motor 7, circuit section 2, etc., and 22 is an operation panel. 23 is a cover cabinet, and 24 is an upper cabinet.

In the thermal transfer color printer of the present invention, paper feeding and printing are performed as shown in FIG. First, when feeding the paper, as shown in FIG.
The paper 25 is fed by one screen in the direction A from the paper holder 26 by the rotational driving force of the platen roller 6 in the counterclockwise direction. At this time, the thermal head 19 is located away from the platen roller 6, the ink film 27 is in a stopped state, and no printing is performed. In addition, the same figure (
In a), 28 is an ink film supply holder, 29
is an ink film take-up holder.

Next, when printing the first color black ink, the platen roller 6 and pinch roller 4 rotate clockwise, and the paper 25 is rewound in the direction B by one screen, as shown in FIG. 2(b). It can be done. At this time, the thermal head 19 is in contact with the platen roller 6, the ink film take-up holder 28 and the ink film take-up holder 29 rotate counterclockwise, and the ink film 27 is wound in the direction B in conjunction with the paper 25. be returned. In this way, the head 19
More heat is applied to the ink film 27, and a predetermined print is made on the paper 25. Furthermore, on the ink film 27, black, yellow, magenta, and cyan are sequentially arranged on each screen, and the above operation is repeated four times to perform four-color overlapping printing in the order of black, yellow, magenta, and cyan, and color printing is performed. Printing is done.

In this way, it is possible to provide a thermal transfer printer with high print quality and high color reproducibility including black and gray.

Figure 3(a) shows yellow 30. Magenta 31. cyan 3
2. When four colors are printed in the order of black 33, yellow 30. Magenta 31. An enlarged cross-sectional view of printing when black 33 is printed on a portion adjacent to the cyan 32 printed portion, and FIG. 3(b) shows the black 33. yellow 3
0. Magenta 31. When printing four colors in the order of cyan 32, yellow 30. Magenta 31. cyan 32
An enlarged cross-sectional view of printing is shown when black 33 is printed on a portion adjacent to the printed portion. In the case of FIG. 3(a), it is clear that a white spot of about 1 dot occurs.

In the above embodiments, a fixed dot size thermal transfer printer with the same printing dot size has been described. If applied to a variable dot size thermal transfer printer that can sequentially vary the amount of heat applied to the ink film in multiple steps for each heating element dot and vary the size of the dots printed on the paper in multiple steps, it is possible to print with smaller dot sizes. Therefore, it is particularly effective when smoothing characters and expressing thin line drawings in black.

Furthermore, in this embodiment, the four-color ink of black, yellow, magenta, and cyan is sequentially printed, but the first color is printed with black ink, and the second color and subsequent colors are printed with yellow, magenta, and cyan ink in any order. It goes without saying that it is okay to do so.

Effect of the invention According to the present invention, the following effects can be expected.

(1) If you have a four-color sequential ink film consisting of four colors of ink: yellow, magenta, cyan, and black, and thermally transfer the printing of the first color from black ink to paper, yellow, magenta, and cyan will be printed. Even if black is printed on an area adjacent to the overprinted area, since the black is printed first, the adhesion of the black ink will not deteriorate, and considering that most of the text and line drawings are printed in black. Print quality is significantly improved. Furthermore, in the case of four-color printing, since a UCR (under color removal) method is used in which common parts of yellow, magenta, and cyan are replaced with black, stability in fixing black is particularly required. From this, the first
Thermal transfer of colored print from black ink to paper is effective in terms of color reproducibility, and it is possible to provide a thermal transfer printer with high print quality.

(2) Furthermore, by controlling the energy applied to each of the many heating elements provided in the thermal head in multiple stages, the amount of heat applied to the ink film sequentially on the multicolor surface can be varied in multiple stages for each dot of the heating element. By varying the size of dots printed on paper in multiple stages, it is possible to provide a thermal transfer printer that can smooth characters and line drawings and has high print quality with smoother gradation.

[Brief explanation of the drawing]

- Figure 1 is a configuration diagram of a thermal transfer printer according to an embodiment of the present invention, Figures 2 (a) and (b) are diagrams explaining the printing operation of the same printer, and Figure 3 (a) is a diagram showing the printing operation of the printer in yellow, magenta, cyan, FIG. 3B is an enlarged view of a printed area when four colors are printed in an overlapping manner in the order of black, and FIG. 6...Platen roller, 7...Main motor, 19...Thermal head, 25...
・Paper, 27... Ink film, 30...
...Yellow, 31...Magenta, 32...
...Cyan, 33...Black. Name of agent: Patent attorney Haruaki Koebi and two others Figure 1 Figure 2 Figure 3

Claims (3)

[Claims] (1) Consisting of a platen roller that conveys paper, a thermal head installed opposite to this platen roller, and heat applied from this thermal head, which has four colors: yellow, magenta, cyan, and black. 1. A thermal transfer printer comprising a four-color sequential ink film, and thermally transferring printing of a first color from black ink to the paper. (2) By controlling in multiple stages the energy applied to each of the multiple heating elements included in the thermal head, 4
2. The thermal transfer printer according to claim 1, wherein the amount of heat applied to the ink film sequentially in color is varied in multiple steps for each dot of the heating element, and the size of the dots printed on the paper can be varied in multiple steps. (3) Using a sequential ink film of black, yellow, magenta, and cyan, black, yellow, magenta, and cyan are used to print achromatic and near-achromatic parts of black and gray, including text and line drawings. The thermal transfer printer according to claim 1, wherein the thermal transfer printer performs four-color overlapping printing.