JPH02307757A - 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] Industrial applications The present invention relates to a thermal transfer printer).

BACKGROUND OF THE INVENTION FIG. 4 is an overall perspective view of a thermal transfer color printer. 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. Reference numeral 6 denotes a platen roller, which together with the pinch roller 4 and capstan roller 5 constitutes a paper feeding mechanism. Here, pinch roller 4. The platen row 26 is driven by the main motor 7. Reference numeral 8 denotes a pinch roller lever that brings the pinch roller 4 into contact with the capstan roller 5 or releases the contact with the capstan roller 5 by interlocking with the operation of the cam. 9 is a peeling roller that separates the ink film from the paper, 1o 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 that stores the paper wound into a roll. Reference numeral 13 denotes a horn bar 3...-7 frame, which is opened and closed by engaging and disengaging the lock lever 14 and the lock lever shaft 16.

-) The 3-bar 7'v-me 13 includes a ribbon feed gear 16 for positioning one end of the ribbon feed, in which an ink film is wound in a roll, and a ribbon feed presser for applying pressing force to the other end of the ribbon feed. 17 are arranged. A head holder 18 has a head 19 fixed thereon, and is fixed to a head arm 20 that is linked to the movement of a cam.

21 is a cooling fan that radiates heat from the main motor 7, the circuit section 2, etc., and 22 is an operation panel. 23 is the top cover, 24
is the upper cabinet.

By the way, in a conventional thermal transfer color printer, printing is performed as shown in FIG. That is, the platen roller 6 and the pinch roller 4 rotate clockwise, and the paper 25 is rewound in the B direction by one screen. At this time, the head 19 is still in contact with the platen roller 6, the ink film holder-ink film take-up holder 29 rotates counterclockwise, and the ink film 27 is rewound in the B direction in conjunction with the paper 26. In this way, heat is applied to the ink film 27 by the head 19, and a predetermined print is made on the paper 25. Here, 26 is a paper holder.

Incidentally, yellow, magenta and cyan are sequentially arranged on each screen on the ink film 27, and color printing is performed by repeating the above operation three times.

Problems to be Solved by the Invention However, with the above configuration, depending on the thickness of the transferred ink on the ink film 2γ where printing is performed,
This has had the problem of overlapping printing misalignment between yellow, magenta, and cyan. FIG. 6 illustrates this phenomenon. FIG. 6 is a diagram showing the paper 25 being pinched between the capstan roller 5 and the pinch roller 4. As shown in FIG. The paper 25 moves while being subjected to tension by the capstan roller 5. If the location where the tension of the paper 25 is generated is approximated by the dotted line at half the thickness t, then the actual driving force of the capstan roller 5 will be The radius a that gives 1/ to 5 is given by the following formula.

a = b -1- 2/l...
River (1) Here, the ink 2 transferred to the paper 25
The radius of the reversely printed portion due to the thickness of 6 will change by this thickness. Since the transferred ink 30 usually has a very low elastic modulus, the radius a in equation (1) is equal to the ink 30.
The thickness t' increases, a = b + 2/l -1- t' ・・・-・・-
---・-(2). In the portion where the incorrect printing was performed, the printing area became long, and skew occurred depending on the printed location, resulting in deterioration of image quality due to printing misalignment.

In view of the above-mentioned problems, the present invention provides a thermal transfer printer that can predict and correct the amount of deviation caused by the thickness of the printed portion, regardless of the change in the thickness of the ink in the printed area.

Means for Solving the Problems In order to solve the above problems, the present invention provides a thermal head for printing by thermally melting ink on an ink film and transferring it to paper, and the above-mentioned paper. and a pair of rollers facing each other for feeding,
The apparatus is configured to include means for predicting the thickness of ink to be transferred onto paper, and to change the amount of paper feed using the means.

Further, the roller on the printing surface side of the paper is provided with a means for changing the diameter of the roller, and the diameter of the roller is corrected in accordance with the thickness of the ink.

Further, a means for detecting the type of paper and ink film or a switching means is provided, and the feed amount is changed depending on the type of paper and ink film.

Effect: By using the above-mentioned printing deviation prevention means based on the thickness of the ink, printing deviation can be reduced and image quality can be improved.

Embodiment A thermal transfer printer according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a thermal transfer printer according to an embodiment of the present invention.

In FIG. 1, the same parts as those shown in FIGS. 4 to 6 are designated by the same numbers.

In the figure, 31 and 32 are heating means. The capstan roller 5 is coupled to and driven by a main motor 7 via a belt. Thermal head 19. Heater 31, heater 32
．． The heater controller 33 , 34 and motor driver 35 of the main motor 7 are controlled by a control system 36 . Further, print data is supplied from outside.

The operation of the thermal transfer printer configured as described above will be explained below with reference to FIGS. 1 to 3.

First, consider a case where external data for printing a pattern as shown in FIG. 2 is input. The data is - first stored in the internal memory 360 by the DMA controller 3, 6b from Ilo '361 of the control system 36; Here, the CPU 36d selects yellow.

It is possible to detect the locations where magenta and cyan colors are produced. Thereafter, the print data is transferred to the l10366, converted by the thermal head controller 37, and the thermal head 19 generates heat. Now, as shown in FIG. 2, when the printed portions 38 of yellow, magenta, and cyan exist with a high color development rate on the C side, the radius of the capstan roller 5 will apparently become thicker by the thickness of the ink.
The paper 25 is skewed to the D side due to the difference in circumferential speed of the capstan roller 5. Therefore, the CPU 36d transfers the data to the processor 1036e, operates the heater controller 34, and heats the heater 32.
The capstan roller 5 is thermally expanded to eliminate the circumferential speed difference,
Skew can be reduced.

In addition, in the case of a printing pattern as shown in Fig. 3, 0, D
Although no directional skew occurs, the feeding direction of the paper 25 is restricted (
assets) will be required. FIG. 3 shows the graph from point F to G
The pattern shown is that the area up to the point is printed in yellow, and the area from point E to point G is printed in magenta. First, the yellow data of the printing pattern data shown in FIG. 3 is transferred and printed from point F to point G. Assuming that the position of the capstan roller 5 is between points E and F at the end of yellow printing,
2-9B-7 It is printed with a radius corresponding to formula (1) and returned to the input direction in FIG. Next, magenta is transferred.

Magenta data is data from point E to point G,
Between point E and point F, the radius of the capstan roller 5 is given by the above equation (2) in consideration of the thickness of the magenta ink, and after magenta printing, point G is printed at the position of point H, causing printing misalignment. Since no printing deviation occurs at point E, the amount of magenta ink to be fed per line after it is gripped by the capstan roller 5 can be changed. Further, the amount of feed p may be corrected at the time of feed 9 in the A direction in FIG.

Similarly, cyan is also controlled.

Depending on the application, for example, when paper and transparent paper are to be exchanged, switching is performed by a spring/I/38 connected to a control system 36 as shown in FIG.

The signal switched by the spring /l/36 is recognized by the control system 36, and the heating means and paper feed amount are adjusted according to the difference in thickness due to the difference in the amount of ink seeping into the paper, such as paper and OHP paper. Just control it.

In addition, heaters 10, 10, etc. are installed outside the capstan roller 5.
7 Although provided, it may be built into the capstan roller 5.

Effects of the Invention According to the present invention, by predicting the thickness of ink and reducing the amount of printing misalignment, high image quality can be obtained, and the industrial value is extremely high.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a thermal transfer printer according to an embodiment of the present invention, Figs. 2 and 3 are explanatory diagrams for explaining the present invention in detail, and Fig. 4 is a schematic diagram of a thermal transfer printer according to an embodiment of the present invention. FIG. 5 is a schematic diagram of a printing portion according to a conventional example, and FIG. 6 is a schematic diagram showing a difference in the apparent outer diameter of the capstan roller depending on the thickness of ink. 4... Pinch roller, 6... Platen roller, 19 Thermal head, 25 - Paper, 27 - Ink film, 31. 32 ... heater, 36
...control system.

Claims (2)

[Claims] (1) It has a thermal head for thermally melting the ink on the ink film and transferring it to the paper for printing, and a pair of rollers facing each other for feeding the paper, and the ink is transferred onto the paper. A thermal transfer printer is provided with a means for predicting the thickness of the paper, and is configured to change the amount of paper feed using the means. (2) The thermal transfer printer according to claim 1, wherein the roller on the printing surface side of the paper is provided with means for changing the diameter of the roller, and the diameter of the roller is corrected according to the thickness of the ink. (3) The thermal transfer printer according to claim 1 or 2, further comprising means for detecting or switching means for detecting the types of paper and ink film, and configured to change the feed amount depending on the types of paper and ink film.