JPS61134273A - Thermal printing control device - Google Patents

Abstract

PURPOSE:To enable printing density to be kept at a constant level according to ambient temperature variations without the use of a power circuit by controlling heat printing time in accordance with preset annual classified data. CONSTITUTION:A clock circuit 15 which always operates connected to a battery 14 is provided on a drive circuit 2. Further, a setting switch 16 which sets a season and a readout circuit 17 which reads such a setting status are provided. MPU7 is so arranged that only a month may be read from the clock circuit 15. It checks a corresponding voltage application time (T1) from ROM5 as a reference and controls the voltage application time (T1) on the basis of data obtained through such a check. Next, the setting switch 16 controls the voltage application time (T1) in accordance with, for instance, the setting status of summer, winter, spring and fall. Consequently no power circuit is required and a thermal printing control device requiring only a small installation space is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a thermal printing control device that controls a device that prints by applying heat to thermal paper.

<Summary of the Invention> This invention is directed to controlling thermal printing time according to predetermined divisions of the year, thereby keeping the printing density constant against changes in ambient temperature without using a power circuit. ing.

<Background of the Invention> FIG. 3 is a block diagram schematically showing a conventional Kemal printing apparatus. In the figure, a suitable voltage is applied to the thermal head 1 from a power source 3 under the control of a drive circuit 2, and this thermal head 1 is thereby conveyed by a pulse motor 4 whose rotation is also controlled by the drive circuit 2. Thermal wrapping paper (not shown): A predetermined printing is performed on this paper.

The drive circuit 2 is an MPU (Micro Process @
orUnit) 7, ROM (Read 0nly
Memory) 5, RAM (Random Acc
es@Memory) B includes a timing generation circuit 6, etc., the ROM 5 stores a graphic pattern for printing in advance, and the timing generation circuit 6 generates a timing pulse as shown in FIG. This pulse has a voltage application period T
1 and a rest period T2, and the pulse motor 4 is rotationally controlled by this timing pulse.

The MPU 7 transmits the data stored in the ROM 5 to the thermal head 1 via the transmission circuit 8 at the timing of the pause period T2 of the timing pulse.

On the other hand, a wrapping paper (not shown) is conveyed under the thermal head 1 in synchronization with the timing of this data transmission.

FIG. 5 is a block diagram showing a schematic configuration of the thermal head 1. As shown in FIG. The thermal head 1 sets the data given at the timing of the pause period T2 of the timing pulse to each bit 1 to n of the shift register 12 in synchronization with the clock.

In the next cycle Tl (voltage application period), the NAND gate group 13 is activated by a timing pulse, so the resistor groups R1 to Rn generate heat according to the set data. By repeating this process, desired printing is performed.

However, in this case, if the printing voltage is kept constant, the color density of the thermal paper will be affected by the ambient temperature and will not be constant. Therefore, conventionally, as shown in FIG. 3, a thermistor 10
and a temperature detection circuit 11 to detect the ambient temperature.
As shown in the figure, the color density is kept constant by controlling the printing voltage according to the detected ambient temperature. However, printing power supplies usually require a large amount of power, so a relatively large space is required to install a power circuit for voltage control.

For example, 6 pieces/my head usually requires about 0.5 W of power per 1 resistor (1 dot), so 30 mm
In order to generate heat from all the resistors even with a head of width 6X30X0.
5=90W of power required. Furthermore, since the power circuit is provided, there is a problem that the cost of the entire device becomes high.

<Object of the Invention> An object of the present invention is to provide a thermal printing control device that is inexpensive and can maintain the color density of thermal paper constant against changes in ambient temperature without requiring much installation space.

<Configuration and Effects of the Invention> “In order to achieve the above object, the control device according to the present invention includes a means for instructing one of the predetermined divisions of the year, and a time period for applying heat to the thermal paper in accordance with the instruction. and a means for controlling.

According to this invention, there is no need for a power circuit like in conventional devices, and the device can be formed using the circuits that the thermal printing device originally has, so it is possible to control thermal printing at low cost and in a small installation space. The device can be realized.

<Description of Embodiments> FIG. 1 is a block diagram schematically showing a thermal printing control device that is an embodiment of the present invention.

In the following, the same reference numerals as in FIG. 3 indicate the same or corresponding parts, and the explanation thereof will be omitted.

The illustrated drive circuit 2 is provided with a clock circuit 15 that is connected to a battery 14 and is always operating, and in addition to this, a setting switch 16 for setting the season and a reading circuit 17 for reading the setting state are provided. It is. In the example shown in FIG. 1, both of these are provided, or the
Even if only one of them is installed, the intended purpose of the present invention can be achieved.

First, the case of the clock circuit 15 will be explained.

Ticket vending machines for station service that print with a thermal head are usually equipped with a clock circuit in order to print the date on the face of the ticket. Therefore, the clock circuit 15 shown in FIG. 1 is also used with this clock circuit for printing the date.

In this invention, by keeping the printing voltage applied to the thermal head 1 constant and controlling the voltage application time TI (see FIG. 4), the color density of the thermal paper is kept constant despite changes in ambient temperature. The MPU 7 is a clock circuit 15
For example, read only the month, and also read the ROM
5 stores the voltage application time T1 set in advance for each month, as shown in FIG. MPU 7 is RO
The corresponding voltage application time T1 is referred to from M5, and based on this, an instruction is given to the timing generation circuit 6 to change the duty ratio of the timing pulse, thereby controlling the voltage application time T1. Note that the voltage application time T1 for each month can be easily set by calculating, for example, based on the average temperature of each month so that the color density is constant.

Next, the case of the setting switch 16 will be explained. For example, in the case where there is no clock circuit available, the setting switch 16 allows manual switching of three stages, for example, summer, winter, and spring/autumn, and the voltage application time T1 is controlled according to the setting state. The illustrated setting switch 16 has a summer display node and an answer display node, and its neutral position indicates the spring/autumn state. The reading circuit 17 reads the setting state and sends the MPU
7 performs the same control as described above by referring to the read setting state and the voltage application time T1 data stored in the ROM 5. Of course, in this case, the voltage pre-stored in the ROM 5 The data on the application time T1 is calculated in advance for summer, winter, spring and autumn.

In addition, in the above explanation, the yearly divisions for which the voltage application time T1 is calculated in advance for each time are monthly when using a clock circuit, and summer, winter, spring and autumn when using a setting switch. However, other appropriate classifications may be used in consideration of annual changes in temperature depending on the installation location, etc., thereby allowing more accurate control.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an outline of a thermal printing control device that is an embodiment of the present invention, FIG. 2 is a diagram showing an example of setting the voltage application time, and FIG. 3 is a block diagram showing a conventional thermal printing device. , Figure 4 is a diagram showing timing pulses, Figure 5 is a diagram showing timing pulses.
The figure is a block diagram showing the schematic configuration of the thermal head.
The figure is a diagram showing an example of controlling the printing voltage. 1... Thermal head 2... Drive circuit 5...
ROM 6...Timing generation circuit 7...MPU 15...Clock circuit 16...Setting switch 17...Reading circuit A,
C:/IIIV hair 1,7. . A,, vI”a, eh, 1. eo.

Claims (3)

[Claims] (1) A control device for a device that performs printing by applying heat to thermal paper, comprising an instruction means for instructing one of the predetermined categories of the year, and a time period for applying the heat in response to the instruction means. A thermal printing control device comprising means for controlling. (2) The thermal printing control device according to claim 1, wherein the instruction means is a clock circuit. (3) The thermal printing control device according to claim 1, wherein the instruction means is a manual setting switch.