JPH09169130A - Color thermal transfer printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely prevent occurrence of color shifts among color inks. SOLUTION: The title printer is so constituted that inks each having different color are thermally transferred to a printing paper by a plurality of thermal heads 2-4 which are provided on a conveying passage of the printing paper with prescribed intervals, then color printing is executed. Reading means 32, 33 that read position information on the printing paper are provided to prescribed positions corresponding to the respective thermal heads 3, 4. Each of the thermal heads 3, 4 is driven based on the timing when the position information on the printing paper is read by the respective reading means 32, 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color thermal transfer printer for performing full color printing by sequentially thermally transferring inks of different colors by a plurality of thermal heads arranged at a predetermined interval on a conveyance path of printer paper. Is.

[0002]

2. Description of the Related Art In a general conventional color thermal transfer printer, an ink sheet in which yellow, magenta, cyan and black inks are applied in order for each print screen is used, and each color ink is printed by one thermal head. Each time the print operation is performed, the ink of each color is overlaid while rewinding the printer paper.
I got a sheet of color print.

However, in the case of such a color thermal transfer printer, since a single color image is superimposed and printed while the printer paper is reciprocated a plurality of times, the printing position for each ink differs depending on the conveyance accuracy of the printer paper, and the color misregistration occurs. Occurs and deteriorates the color reproducibility of the printed image, and the time required to complete the color printing becomes longer.Furthermore, even if the ink of a certain color is not printed at all, However, there is a problem in that the ink sheet is wasted because the ink sheet is idle-fed.

Therefore, what solves these problems is
For example, it is proposed in Japanese Patent Laid-Open No. 2-1334.
What is proposed in this Japanese Patent Laid-Open No. 2-1334 will be described below with reference to FIGS. 3 and 4. Here, FIG. 3 is a side view showing a schematic configuration of a conventional color thermal transfer printer, and FIG. 4 is an explanatory view showing operation timing in the conventional color thermal transfer printer.

As shown in FIG. 3, a conventional color thermal transfer printer is arranged at equal intervals on a conveying path for conveying a long printer sheet 1 fed from a roll in the direction of arrow A along the longitudinal direction. Are four thermal heads 2, 3, 4, 5 in which a plurality of heating resistors are arranged in a line in the width direction of the printer paper 1, and each is yellow Y, magenta M, cyan C and black B.
Ink sheet of each color with one side of the ink
7, 8 and 9 are provided.

Further, the printer paper 1 and the ink sheets 6 to 9 of the respective colors are conveyed while pressing the thermal heads 2 to 5 so that the ink application surfaces of the ink sheets 6 to 9 come into contact with the printer paper 1. The platen rollers 10, 11, 12, and 13 and the platen rollers 10 to 13 are released from the pressure contact state before printing, and the platen rollers 10 to 13 are pressure contacted at the start of printing, and the thermal head 2 causes the yellow ink Transfer and print the ink on sheet 6 and print on printer paper 1
When the front end of the printed material reaches the pressing portion between the thermal head 3 and the platen roller 11, the platen roller 11
Bearings 14 that sequentially control the pressure contact so that
15,16,17, Plunger 18,19,20,2
1, and a pressure contact control mechanism including springs 22, 23, 24, 25.

To perform the printing operation, first, a color image signal is stored in a buffer memory (not shown) in advance, the platen roller 10 is brought into a pressure contact state, and then the yellow ink sheet 6 and the printer paper 1 are conveyed. While doing so, the image signal corresponding to yellow Y is read from the buffer memory, and thereby the thermal head 2 is driven to heat and melt the yellow ink on the yellow ink sheet 6 and transfer it to the printer paper 1.

Here, when the print scanning line pitch on the printer paper 1 is d and the intervals between the thermal heads 2 to 5 are equal to l ₀ , n (n is a natural number) between adjacent thermal heads. Assuming that the print scan line can be drawn, then l ₀ = nd.

As shown in FIG. 2, printing of yellow Y is started at time t ₀ , printing of yellow ink is performed up to the nth line from the top line of the image, and printing with the yellow ink printed by the thermal head 2 is performed. The platen roller 11 is brought into a pressure contact state at time t ₁ when the print line at the head of the image comes directly below the thermal head 3. Then, at the same time that the thermal head 2 transfers the yellow ink of the (n + 1) th line, the image signal corresponding to the magenta ink of the first line of the image is read from the buffer memory, and thereby the thermal head 3 is driven to drive the magenta ink. The magenta ink on the sheet 7 is heated and melted and transferred to the printer paper 1.

Similarly, at the time t ₂ when the first print line of the print image of yellow and magenta ink comes directly under the thermal head 4, the platen roller 12 is brought into pressure contact with the image signal corresponding to the cyan C ink. Drive the thermal head 4 to transfer the cyan ink onto the printer paper 1.

Finally, at the time t ₃ when the first print line of the print image with the yellow, magenta, and cyan inks is immediately below the thermal head 5, the platen roller 1
The thermal head 5 is driven by the image signal corresponding to the black B ink, and the black ink is transferred to the printer paper 1 with 3 being in a pressure contact state.

In this way, the printing operation is performed in the order of yellow Y, magenta M, cyan C and black B. Therefore, the printing ends in the same order as this,
Time t ₄ to yellow Y, magenta M to the time t _5, time t ₆
Cyan C, platen from which printing is completed so that black B to time t ₇ in order roller 1:10
3 is released and the corresponding ink sheets 6 to 9 are released.
Stop transporting

As a result, it is not necessary to reciprocally convey the printer paper 1, and it is possible to prevent the occurrence of print position deviation for each color ink due to conveyance accuracy, improve the print image quality, and delay each color with a predetermined time delay. Since they can be recorded in parallel, the time required to finish color printing can be greatly reduced. Furthermore, since the ink sheet corresponding to the ink that is not printed at all is not conveyed, waste of the ink sheet can be prevented, running costs can be reduced, and the length of print paper that can be printed is limited. It becomes possible to print a banner.

[0014]

However, in the conventional color thermal transfer printer described above with reference to FIGS. 3 and 4, the printing operation of each color ink is performed at a constant time interval (t ₁ -t ₀ ) to perform print positioning. Since the printing paper 1 is controlled, the transport distance of the print paper 1 in a certain period of time varies depending on the thickness and material of the printer paper 1, the pressure contact state of the platen rollers 10 to 13, and so on. There was a problem that it could not be completely prevented.

The present invention has been made in view of the above points, and an object of the present invention is to provide a color thermal transfer printer capable of completely preventing the occurrence of color misregistration for each color ink.

[0016]

SUMMARY OF THE INVENTION According to the present invention, a plurality of thermal heads arranged at a predetermined interval on a conveyance path of a printer paper thermally transfer inks of different colors to the printer paper to perform color printing. A color thermal transfer printer, at a predetermined position with respect to the thermal head, provided with a reading unit that reads the positional information on the printer paper, based on the timing when the positional information on the printer paper is read by the reading unit,
The thermal head is driven.

As a result, since each thermal head is driven based on the detection timing of the position information on the printer paper, each thermal head is driven at the same timing with respect to the position of the printer paper. It is possible to completely prevent the occurrence of color misregistration for each color ink.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a color thermal transfer printer of the present invention will be described below with reference to FIGS. 1 and 2 in which three color inks of yellow, magenta and cyan are color printed. The same parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.
Here, FIG. 1 is a side view showing a schematic configuration of the color thermal transfer printer of the present embodiment, and FIG. 2 is a flowchart showing the operation of the color thermal transfer printer of the present embodiment.

The color thermal transfer printer of this embodiment is
As shown in FIG. 1, three thermal heads 2. are arranged at equal intervals on the conveyance path of the printer sheet 1 conveyed by a pinch roller and a paper feed roller.
3.4, and ink sheets 6, 7, and 8 of the respective colors to which yellow Y, magenta M, and cyan C inks have been applied
And platen rollers 10, 11 and 12 that convey the printer sheet 1 and the ink sheets 6 to 8 of each color while pressing the thermal heads 2 to 4 so that the ink sheets 6 to 8 come into contact with the printer sheet 1. Is provided.

Further, with respect to the thermal head 3, the write head 31 is provided on the paper feed side of the printer paper 1 by a predetermined distance l _{1 with} respect to the thermal head 2, and the positional information is written on the back surface of the printer paper 1 by magnetic recording. And a read head 32 which is provided on the paper feed side of the printer sheet 1 by a predetermined distance l ₁ and magnetically reproduces the position information recorded on the printer sheet 1 and reads the thermal head 4 by a predetermined distance l _1. It is provided on the paper feed side of 1.
A read head 33 for magnetically reproducing and reading the position information recorded on the printer paper 1 is provided.

Next, the operation of the color thermal transfer printer configured as described above will be described with reference to the flow chart of FIG. When the three-color printing operation is started, the write head 31 writes the position information on the printer paper 1 by magnetic recording (step 1), and after the predetermined time T has passed from the writing of the position information, the thermal head 2 is started to be driven. Then, the yellow ink on the yellow ink sheet 6 is melted by overheating and transferred to the printer paper 1 (step 2).

Further, the reading head 32 constantly monitors the positional information on the printer paper 1, and when the positional information is read by the reading head 32 (step 3), the reading of the positional information takes a predetermined time T. After the lapse of time, the thermal head 3 is started to drive, the magenta ink on the magenta ink sheet 7 is overheated and melted, and transferred to the printer paper 1 (step 4).

Further, the reading head 33 constantly monitors the positional information on the printer paper 1, and the positional information is read by the reading head 33 (step 5).
Then, after a predetermined time T has passed from the reading of the position information,
The driving of the thermal head 4 is started, the cyan ink on the cyan ink sheet 8 is overheated and melted, and transferred to the printer paper 1 (step 6).

Therefore, in the above-described color thermal transfer printer of the present embodiment, the timing of the printing operation for each color ink is reset based on the positional information on the printer paper 1, so that the printer paper 1 It is possible to match the print operation timing for each color ink with respect to the transport position.
It is possible to completely prevent the occurrence of print position deviation for each color ink regardless of the transport speed of the ink.

In order to simplify the description, one embodiment of the color thermal transfer printer of the present invention will be described.
Although what has been described is one in which color inks are color printed, the present invention is not limited to this, and it is apparent that the present invention may be applied to those in which four or more color inks are sequentially color printed in parallel. .

In the above embodiment, the write head 31 writes the position information on the printer paper 1 by magnetic recording, and after a predetermined time T elapses from the writing of the position information, the yellow ink is printed on the printer paper 1. Although the operation is started, the position information is written in advance on the printer paper 1, a read head is provided in place of the write head 31, the position information is read by the read head, and the yellow ink is read after a predetermined time T elapses. By starting the print operation on the printer paper 1, the print operation timing for each color ink with respect to the transport position of the printer paper 1 may be matched.

Further, in the above embodiment, the case where the write head 31 writes the position information on the back surface of the printer sheet 1 by magnetic recording has been described.
Colored yellow ink may be printed as position information at a predetermined position on the surface of the printer paper 1. In this case, the magnetic head is not required, so that the cost can be suppressed.

[0028]

Since the color thermal transfer printer of the present invention is configured as described above, each thermal head is driven based on the detection timing of the position information on the printer paper, so that each thermal head is mounted on the printer paper. Since the driving is performed at the same timing with respect to the position, it is possible to completely prevent the occurrence of color misregistration for each color ink.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a schematic configuration of an embodiment of a color thermal transfer printer of the present invention.

FIG. 2 is a flowchart showing an operation in one embodiment of the color thermal transfer printer of the present invention.

FIG. 3 is a side view illustrating a schematic configuration of a conventional color thermal transfer printer.

FIG. 4 is an explanatory diagram showing operation timing in a conventional color thermal transfer printer.

[Explanation of symbols]

 1 Printer Paper 2 Thermal Head 3 Thermal Head 4 Thermal Head 6 Yellow Ink Sheet 7 Magenta Ink Sheet 8 Cyan Ink Sheet 10 Platen Roller 11 Platen Roller 12 Platen Roller 31 Writing Head 32 Reading Head 33 Reading Head

Claims (4)

[Claims] 1. A color thermal transfer printer for performing color printing by thermally transferring inks of different colors to a printer paper by a plurality of thermal heads arranged at a predetermined interval on a conveyance path of the printer paper, wherein: A reading means for reading the position information on the printer paper is provided at a predetermined position with respect to the thermal head, and the thermal head is driven based on the timing when the position information on the printer paper is read by the reading means. A color thermal transfer printer. 2. The color thermal transfer printer according to claim 1, further comprising writing means for writing positional information on the printer paper. 3. The color thermal transfer printer according to claim 2, wherein the writing unit magnetically records position information on printer paper. 4. The color thermal transfer printer according to claim 2, wherein the writing unit prints position information with ink on a printer sheet.