JPH0647946A - Multi-color printing method in thermal printer - Google Patents

Abstract

PURPOSE:To make dimensions of a power source small, by a method wherein a medium is conveyed to a plurality of arranged printing heads, a different printing timing pulse is generated every printing head and a driving current is supplied to the printing heads each by printing head impression pulses each by corresponding to the printing timing pulse. CONSTITUTION:For example, the first and second printing heads 12, 13 are separated from each other by a fixed distance and printing to a medium is performed by the first printing head 12 and then by the second printing head. When a control part 21 receives slit data through a slit sensor 22, the first printing timing pulse 28 is applied to the first head 12 and 1/2 cycle delaying part 23. When the 1/2 cycle delaying part 23 receives the first printing timing pulse 28, the second printing timing pulse 29 which has delayed by 1/2 cycle is applied to the second printing head 13. The printing data is transmitted to the printing heads 12, 13 each along with the timing pulses 28, 29 each and a driving current corresponding to the printing data is supplied by the printing head impression pulses each. Then a cooling time of the first printing head 12 is allotted to a driving time of the second printing head 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor printing method for a thermal printer.

[0002]

2. Description of the Related Art Conventionally, thermal printers that selectively melt heat-melting ink and transfer it to a medium such as recording paper are
It is used for small printers such as word processors because of its simple mechanism and easy maintenance. Further, recently, a multi-head type thermal printer capable of performing multi-color printing has been provided.

In the thermal printer,
The print heads of the same number as the number of colors are provided to perform printing on the medium a plurality of times, or the thermal transfer ink ribbon coated with multicolor ink is used to repeatedly perform the printing on the medium for the number of colors. Among them, in the thermal printer having the print heads of the number of colors, it is possible to perform printing for a plurality of colors at the same time, so that the printing speed can be increased.

FIG. 2 is a schematic view of a conventional thermal printer,
FIG. 3 is a diagram showing the printing operation of the conventional thermal printer, and FIG. 4 is a conceptual diagram of the printing operation in the conventional thermal printer. FIG. 3A is a diagram showing a state when the front end of the medium reaches the second print head, and FIG. 3B is a diagram showing a state when the rear end of the medium reaches the first print head. In the figure, 11 is a thermal transfer ink ribbon to which different colors of ink are applied, and 12 is a first color for printing the first color.
A print head, 13 is a second print head for performing printing of a second color, 14 is a first platen disposed facing the first print head 12, and 15 is a face facing the second print head 13. The second platen 16 provided is a medium.

The first print head 12 and the second print head 13 are arranged at positions separated by a distance A, and the first print head 12 first prints the first color on the medium 16, and then the second print head 13 is printed. The second print head 13 prints the second color. Then, when a certain point on the medium 16 is printed with two colors, the portion printed by the first print head 12 is conveyed by the first print head 12 so that color misregistration does not occur between the first color and the second color. Accordingly, when the second print head 13 is reached, printing is performed by the second print head 13.

Therefore, the timing of the printing operation by the first print head 12 and the timing of the printing operation by the second print head 13 are shifted as shown in FIG. Then, the printing operation by the first print head 12 and the printing operation by the second print head 13 can be simultaneously performed (overlap) for the time B shown in the figure, and the printing time can be shortened accordingly.

[0007]

However, in the conventional multicolor printing method for the thermal printer, each print head 1 is operated while the print operation by the first print head 12 and the print operation by the second print head 13 are simultaneously performed.
The drive current supplied to 2 and 13 is doubled. FIG. 5 is a time chart showing the printing operation of the conventional thermal printer.

As shown in the figure, the first print head application pulse is generated every time each print timing pulse is generated, and the first print head 12 (FIG. 3) performs the printing operation.
When the second print head applied pulse is generated, the second print head 1
3 performs the printing operation, and at time B, the first print head 1
A combination of the drive current for 2 minutes and the drive current for the second print head 13 is required. In addition, C is a cooling time of each print head 12 and 13 provided for each applied pulse.

As described above, since the drive current supplied to each print head 12 and 13 is doubled, a power supply (not shown) having a doubled capacity is required, and the size of the power supply is increased and the cost is increased. I will end up. The present invention can solve the problems of the multicolor printing method in the conventional thermal printer, and reduce the size of the power supply by making the capacity of the power supply for the print head necessary for one print head. Moreover, it is an object of the present invention to provide a multicolor printing method for a thermal printer that can reduce the cost.

[0010]

Therefore, in the multicolor printing method in the thermal printer of the present invention, the medium is conveyed to a plurality of print heads, and the print timing is different for each print head. A pulse is generated, and each print head application pulse is generated corresponding to each print timing pulse.

Then, a drive current is supplied to each print head by each print head application pulse.

[0012]

According to the present invention, the medium is conveyed to the plurality of print heads arranged as described above, and print timing pulses of different timings are generated for each print head, and each print timing pulse is handled. To generate each print head applied pulse.

A drive current is supplied to each print head by each print head application pulse. A plurality of print heads perform printing operations at different timings to perform multicolor printing. In this case, since the print head applied pulses are not generated at the same time, the drive current supplied can be reduced.

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a control block diagram of a thermal printer to which the multicolor printing method according to the first embodiment of the present invention is applied, and FIG. 6 is a thermal printer to which the multicolor printing method according to the first embodiment of the present invention is applied. FIG. 7 is a schematic view of the printer, and FIG. 7 is a time chart showing the printing operation of the multicolor printing method in the thermal printer of the present invention.

In FIG. 6, 11 is a thermal transfer ink ribbon coated with different color inks, 12 is a first print head for printing a first color, and 13 is a second print head for printing a second color. , 14 is a first platen arranged to face the first print head 12, 15 is a second platen arranged to face the second print head 13, and 16 is a medium.

The first print head 12 and the second print head 13 are arranged at positions separated by a distance A, and the first print head 12 first prints the first color on the medium 16, and then the second print head 13 is printed. The second print head 13 prints the second color. Then, when a certain point on the medium 16 is printed with two colors, the portion printed by the first print head 12 is conveyed by the first print head 12 so that color misregistration does not occur between the first color and the second color. Accordingly, when the second print head 13 is reached, printing is performed by the second print head 13.

Reference numeral 20 is a slit plate connected to the second platen 15 and rotating in conjunction with the second platen 15, and 22 is a slit sensor for detecting slits formed in the slit plate 20. Next, the operation of the thermal printer having the above configuration will be described. 1 and 7, 11 is a thermal transfer ink ribbon, 12 is a first print head, 13 is a second print head, 21 is a control unit for controlling the entire thermal printer, 22 is a slit sensor, and 23 is 1/2 cycle. It is a delay unit, and when the first print timing pulse 28 for printing the first print head 12 is operated,
The second print timing pulse 29 for printing the print head 13 is delayed by 1/2 cycle.

Reference numeral 24 is a mechanism control unit for controlling the printing mechanism, and 2
6 is a motor for rotating each platen 14, 15 (FIG. 6) and the like, 27 is each print head 12, 13 during a printing operation.
Is a magnet for pressing the platens 14 and 15 against the platens 14, 15 is a print head control signal for causing the print heads 12 and 13 to perform a printing operation in accordance with the print data. The print timing pulse of each print head 12, 13 is generated by slit data from a slit sensor 22 provided on the slit plate 20. That is, when the control unit 21 receives the slit data from the slit sensor 22, it generates a print timing pulse and outputs it as a first print timing pulse 28 to the first print head 12 and the 1/2 cycle delay unit 23. Upon receipt of the first print timing pulse 28, the 1/2 cycle delay unit 23 delays by 1/2 cycle and outputs it as a second print timing pulse 29 to the second print head 13.

The print timing pulses 28,
29, the print data is transferred to the print heads 12 and 13, and the drive current corresponding to the print data is applied from the power source (not shown) to the print heads 1 and 13 by the print head applied pulse.
It is supplied to Nos. 2 and 13, and the printing operation is performed. in this case,
Since the first print timing pulse 28 and the second print timing pulse 29 are shifted by 1/2 cycle by the 1/2 cycle delay unit 23, as shown in FIG.
The second print head application pulse is generated during the print head application pulse, and the cooling time C of the first print head 12 can be assigned to the drive time of the second print head 13.

In this embodiment, a 1/2 cycle delay unit 23 is provided as a means for shifting the generation of the first print timing pulse 28 and the second print timing pulse 29 by 1/2 cycle. It is also possible to use the slits formed on the plate 20 by half so that double slit data can be obtained and used for the first print head 12 and the second print head 13.

Next, a second embodiment of the present invention will be described. FIG. 8 is a control block diagram of a thermal printer to which the multicolor printing method according to the second embodiment of the present invention is applied, and FIG.
6 is a time chart showing a printing operation in the second embodiment of the present invention. In the figure, 11 is a thermal transfer ink ribbon to which different colors of ink are applied, 12 is a first print head for printing a first color, 13 is a second print head for printing a second color, and 32 is a second print head. An Nth print head for printing N colors, 21 a control unit, 22 a slit sensor,
24 is a mechanism control unit, 26 is a motor, 27 is a magnet,
Reference numeral 30 is a print head control signal, and 33 is a 1 / N cycle delay unit.

In this case, the N print heads 12, 13,
..., 32 are provided. When the control unit 21 receives the slit data from the slit sensor 22, the control unit 21 generates a print timing pulse and outputs the first print timing pulse 35.
As the first print head 12 and the 1 / N cycle delay unit 3
Output to 3. When the 1 / N cycle delay unit 33 receives the first print timing pulse 35, the 1 / N cycle delay unit 33 delays it by 1 / N cycle, and as the second print timing pulse 36, the second print head 13 and the next 1 / N cycle delay unit 3 are provided.
Output to 3.

When the 1 / N cycle delay unit 33 receives the second print timing pulse 36, the 1 / N cycle delay unit 33 further outputs 1 / N.
It is delayed by the cycle and output as a third print timing pulse to a third print head (not shown) and the next 1 / N cycle delay unit 33. Similarly, the print timing pulse is delayed by 1 / N cycle,
Output to the Nth print heads 12, 13, ..., 32.

In this case, as shown in FIG. 9, the second to Nth print head application pulses are generated between the first print head application pulses, and the cooling time C of the first print head 12 is set to the second time.
~ It can be assigned to the driving time of the Nth print head 13, ..., 32. Therefore, each print head 12, 1
The driving currents supplied to 3, ..., 32 can be made uniform.

The present invention is not limited to the above-mentioned embodiments, but various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

[0026]

As described in detail above, according to the present invention, a medium is conveyed to a plurality of print heads, and print timing pulses of different timings are generated for each print head. Each print head application pulse is generated corresponding to the print timing pulse.

Then, a drive current is supplied to each print head by each print head application pulse. A plurality of print heads perform printing operations at different timings to perform multicolor printing. In this case, since the print head applied pulses are not generated at the same time, the drive current supplied can be reduced. Therefore, the capacity of the power supply for the print head can be made as small as necessary for one print head, and the size of the power supply can be reduced, and the cost can be reduced.

Further, since the printing operation by the other print head can be performed during the cooling time of the certain print head, the printing speed can be increased.

[Brief description of drawings]

FIG. 1 is a control block diagram of a thermal printer to which a multicolor printing method according to a first embodiment of the present invention is applied.

FIG. 2 is a schematic view of a conventional thermal printer.

FIG. 3 is a diagram showing a printing operation of a conventional thermal printer.

FIG. 4 is a conceptual diagram of a printing operation in a conventional thermal printer.

FIG. 5 is a time chart showing a printing operation of a conventional thermal printer.

FIG. 6 is a schematic view of a thermal printer to which the multicolor printing method according to the first embodiment of the present invention is applied.

FIG. 7 is a time chart showing the printing operation of the multicolor printing method in the thermal printer of the present invention.

FIG. 8 is a control block diagram of a thermal printer to which a multicolor printing method according to a second embodiment of the present invention is applied.

FIG. 9 is a time chart showing the printing operation in the second embodiment of the present invention.

[Explanation of symbols]

 12 1st print head 13 2nd print head 16 Medium 28, 35 1st print timing pulse 29, 36 2nd print timing pulse 32 Nth printhead 37 Nth print timing pulse

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Claims (1)

[Claims] 1. A medium is conveyed to a plurality of print heads arranged, (b) print timing pulses at different timings are generated for each print head, and (c) each print timing pulse is supported. Then, each print head applied pulse is generated, and (d) a drive current is supplied to each print head by each print head applied pulse.