JPH0930023A - Thermal head device - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the efficiency of using the power supply of the thermal head device. [Constitution] As the printing rate of the label 2 becomes higher than the continuous rated capacity of the power supply device 4, the pause time until the printing of the next label 2 is started becomes longer. As a result, when the continuous rated capacity is exceeded, the power feeding interval becomes long and heat is sufficiently radiated, so that the capacity of the power supply device can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal head device for continuously printing on an object to be printed using a thermal head.

[0002]

2. Description of the Related Art An example of a thermal head device for printing and issuing a product name, price, ruled line, etc. on a label that is continuously fed will be described below.

Conventionally, a thermal head device of this type is known as shown in FIG. Reference numeral 1 is a label feeder, which continuously feeds the label 2 in the direction of arrow A. A thermal head 3 is composed of a power feeding circuit 3a and a printing element 3b. The peak corresponding power supply device 4 feeds power to the printing element 3b via the power feeding circuit 3a to print on the label 2.
Reference numeral 5 denotes a controller, which receives a print command and reads data from a memory described later to control the operation of all the devices.
6, a memory 7 for storing a plurality of label printing patterns and label feeding data, a label feeding control means 8 for controlling the feeding operation of the label feeding device 1, and a printing element of the thermal head 3. Energization control means 9 for controlling energization to 3b
It is composed of

The CPU 6 reads out from the memory 7 the print pattern of the label 2 designated by the print command given by the operator and the feeding data thereof, and the label feeding control means 8 based on the feeding data. The label feeding apparatus 1 controls the feeding operation of the label 2 and the energization control unit 9 controls the energization of the printing element 3b of the thermal head 3 through the feeding circuit 3a in synchronization with the operation. The print pattern read out from 7 is printed.

The feeding operation of the label feeding apparatus 1 is driven by a stepping motor to feed out the label 2 at a constant time interval by a fixed amount, and while the label 2 is stopped, a 1-dot line is formed along the width direction of the label 2. It is configured to perform printing, and the power supply to the thermal head 3 is stopped while the printing of one label is finished and the label is sent to a position where printing of the next label is started.

By the way, the peak corresponding power supply device 4 used in the conventional thermal head device is a power supply device capable of supplying power while keeping the output voltage constant for a certain period of time against an overload. It is a figure which shows an example of the dynamic load characteristic of the peak corresponding power supply device of rated output 4A and peak output current 10A. The dynamic load characteristic of this example can sustain a peak output current of 10 A for 1.6 ms, then 10-1.6 = 8.4 ms
The output characteristic is that the output voltage cannot be kept constant unless the output current is kept at 0.1 A or less.

Time t required for printing one label 2
p is about 1 second, and the total energization is performed according to the number and thickness of characters and line segments to be printed, that is, the number of dots required to print one label (cumulative number of energized printing elements). The amount changes. FIGS. 5A and 5B show energization patterns of two types of labels having different total energization amounts required for printing, and FIG. 5A shows an average energization amount of about 4 A.
In (b), the average value of the energization amount is about 7 A, and the current value when energizing all the printing elements 3b is 10 A. FIG.
In (a) and (b), the bar graph indicates 1 of the printing element 3b.
The printing rate for each dot line and the power supply current proportional thereto are shown.

With such continuous power supply, the continuous rated capacity is 4 A,
When the peak corresponding power supply device 4 having a peak current value of 10 A is used, the ratio of the average energization amount to the peak current value, in other words, the value of (the number of print dots) / (the number of dots on the entire print surface) (hereinafter, "print ratio" 5) is 4/10 = 25% for the label of FIG. 5A and 7/10 for the label of FIG. 5B.
= 70%. Since the label with a print rate of 25% is within the continuous rated capacity, it is possible to issue (print) the label continuously, but with the label in FIG. 5 (b), the print rate exceeds the continuous rated value. The temperature of the peak corresponding power supply device 4 rises and exceeds the allowable temperature. It should be noted that the symbol tp in FIG. 5 is the time required to print one label, and to is the time required to feed the label to the next print position.

Therefore, in the conventional thermal head device, when the label having the maximum printing rate is continuously issued, the temperature rise of the peak corresponding power supply device is within the allowable temperature.
A large power supply unit was used so that the average energization amount when printing a label with the maximum printing rate did not exceed the rated capacity.

[0010]

As described above, in the conventional thermal head device, a large power supply device corresponding to the label having the maximum printing rate and having the continuous rated capacity is used, and the overall size of the thermal head device is increased. And increased costs.

The present invention has been made for the purpose of solving the above-mentioned problems, and aims to reduce the capacity of a peak-capable power supply device by maximally utilizing the instantaneous load capacity of the peak-capable power supply device. Therefore, it is an object of the present invention to obtain a thermal head device capable of cost reduction.

[0012]

SUMMARY OF THE INVENTION A thermal head device according to the present invention comprises a print object feeding means for feeding a print object to a thermal head at a constant speed, a power supply device for feeding power to the thermal head, and a plurality of power supply devices. A memory that stores the printing patterns of the types of print objects and the issue interval data for the print objects for that printing rate, and the print pattern of the print object that is commanded from this memory, its printing rate, and the printing rate for that printing rate Data reading means for reading the issue interval data of the object, power supply control means for controlling power supply from the power supply device to the thermal head based on the read print pattern of the object to be printed, and the read object. The feeding operation of the printed material feeding means is controlled based on the print interval data of the printed material, and after the printing of one printed material is completed, the printing of the next printed material is started. It is obtained by a publication interval control means for controlling the interval of issuing up.

[0013]

According to the present invention, when the print command is given, the data reading means reads the print pattern and the issue interval data for the print rate from the memory when the print command is given, and the power feeding control means feeds power to the thermal head. The print interval is controlled by the control unit to print the read print pattern on the print target, and the issuing interval control means sets the time until start printing on the next print target to the read issue interval data. Basically, the printing interval is controlled so that the printing interval becomes longer as the printing rate exceeds the rated capacity of the power supply device and becomes higher. Therefore, the dynamic load characteristic of the power supply device can be effectively used, and a print pattern having a high printing rate can be continuously printed by the power supply device having a small rated capacity.

[0014]

【Example】

Embodiment 1 FIG. FIG. 1 is a diagram showing an embodiment of the present invention.
And the same reference numerals respectively indicate the same or corresponding parts. In the figure, the thermal head device includes a label feeding device 1, a thermal head 3, a peak corresponding power supply device 4, and a controller 5 as in the conventional example of FIG. In addition to the CPU 6, the memory 7, the label feeding control means 8 and the energization control means 9, the controller 5 has a built-in memory 10 in which printing rates of a plurality of types of labels and issuing interval data for each printing rate are stored. And this memory 1 by the CPU 6
From 0, the issuance interval data of the label instructed to print is read.

The relationship between the printing rate and the issuing interval is not limited when the printing rate is 25% or less corresponding to the continuous rated capacity of the power supply device 4, and the issuing interval takes into consideration the feeding speed of the label 2 and the like. It is set to a fixed time to (ms). On the other hand, when the printing rate exceeds 25%, the issuing interval is determined based on the experimental data of the temperature rise of the power supply device 4 so that the issuing interval becomes longer as the printing rate becomes higher.
Shows an example.

[0016]

[Table 1]

Next, the operation of the part of this embodiment different from the conventional device will be described. Upon receipt of the print command, the CPU 6 reads out the label issue interval data instructed from the memory 10, and uses the data combined with the feed data read out from the memory 7 to feed the label via the label feed control means 8. The feeding operation of the device 1 is controlled to feed the label 2 in the direction of arrow A.

FIG. 2 is a diagram showing the printing rates of the three types of labels a, b, and c and their issuing intervals. FIG. 2A shows the label a.
Has a printing rate of 20%, which is lower than the printing rate of 25% corresponding to the continuous rated capacity 4A of the power supply device 4, so there is no limitation on the issuing interval and the label is fed to the first printing position of the next label a. The time to required until it is determined is a time determined by the arrangement interval of the label a and the feeding speed of the label feeding device 1. If the printing rate does not exceed 25%,
The temperature rise of the power supply device 4 is within the allowable temperature.

However, in the case of a label having a printing rate of 90% such as the label b shown in FIG. 2B, the energization amount in the printing time tp of one label is much larger than the rated capacity.
The calorific value increases. For this reason, if the state in which printing is started after the time to when the next label b is fed to the printing position is continued, the temperature of the power supply device 4 rises and exceeds the allowable temperature.

Therefore, in this embodiment, the printing rate 91 in Table 1 is
As shown in the column of ~ 100, the next label 2b is fed to the printing position after the next label 2b is fed to the printing position in order to wait 3 × to until the next printing is started. Device 1
The feeding operation is stopped, the feeding of the label 2b is restarted after that, and the power supply to the thermal head 3 is controlled to start printing, thereby increasing the printing interval.

Next, since the printing rate of the label c shown in FIG. 2 (c) is 45%, as shown in the columns of printing rates 41 to 50 in Table 1, the feeding of the label feeding device 1 is performed. Stop time 1.
2 × to, and the issuing interval is 2.2 × to.

As described above, when the printing rate of one label is low and does not exceed the continuous rated capacity of the power supply device, the label issuing interval is not limited, while the printing rate of the label is high and the rated capacity is increased. When it exceeds, the label issuance interval is lengthened according to the high printing rate to radiate heat from the power supply unit, so the capacity is several times the continuous rated capacity within the range of the dynamic load characteristics of the power supply unit. It is possible to print a label having a high printing rate, which is a burden on the printer. Therefore, it is possible to reduce the size and cost of the entire thermal head device by using the power supply device having a small continuous rated capacity.

[Brief description of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an issuance interval of labels having different printing rates according to the embodiment.

FIG. 3 is a block diagram showing a conventional thermal head device.

FIG. 4 is a diagram showing a dynamic load characteristic of a peak-capable power supply device.

5 (a) and 5 (b) are explanatory views showing different printing rates when printing a label.

[Explanation of symbols]

1 ... Label feeding device, 2 ... Label, 3 ... Thermal head, 4 ... Power supply device, 5 ... Controller, 6 ... CPU,
7, 10 ... Memory, 8 ... Label feeding control means, 9 ... Power feeding control means.

Claims (1)

[Claims] 1. A printing material feeding means for feeding a printing object to a thermal head at a constant speed, a power supply device for feeding power to the thermal head, a printing pattern of plural kinds of printing objects, and a printing rate thereof. A memory for storing issuance interval data of the print object; and a data reading means for reading out the commanded print pattern of the print object, its printing rate, and the issuance interval data of the print object for the printing rate from the memory. Power supply control means for controlling power supply from the power supply device to the thermal head based on the read print pattern of the print target, and the print target transfer based on the read issue interval data of the print target. An issue interval control means for controlling the feeding operation of the feeding means to control the issue interval from the completion of printing of one printed material to the start of printing on the next printed material. For example was the thermal head apparatus.