JPS62130861A - Thermal recording type printer - Google Patents

Abstract

PURPOSE:To enable a printing operation to be performed with a fixed electric power, by constituting a power source for driving a thermal recording head of a constant current circuit, a storage battery device and a constant voltage circuit, and controlling printing and paper feeding while monitoring the amount of electricity stored in the storage battery device. CONSTITUTION:In a high-speed printing condition, when printing data 14 are sent, power consumption in a thermal recording head 1 rapidly increases, and the supply of electricity from a constant current circuit 7 becomes insufficient, resulting in that the quantity of electricity is decreased, and the terminal voltage of a storage battery device 8 is lowered. When the terminal voltage is lowered to or below a deceleration detecting level, a decelerating signal 12 is sent to a printing-controlling circuit 3', which lowers printing speed by increasing the pulse separations of a printing signal 5 and a paper feed controlling signal 6 at predetermined rates. As the power consumption is decreased due to a change in the content of the printing data during the decelerated and low-speed printing, the supply of electricity exceeds the consumption, so that the quantity of electricity is increased. When the quantity of electricity exceeds an acceleration detecting level, an electricity quantity monitoring circuit 10 sends an accelerating signal 13 to the printing-controlling circuit 3', which increases the printing speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermal recording type printing device used as a character and graphic output terminal for computers and the like.

[Summary of the invention]

The present invention uses a constant current circuit capacitor as a power source for driving a thermal recording head.
It is constructed from a constant voltage circuit, and performs printing control and paper feeding control while monitoring the amount of electricity stored in a capacitor.

[Conventional technology]

Conventionally, as shown in FIG. 4, it consists of a thermal recording head 1, a thermal recording head drive power source 2, a print control circuit 3, and a paper feed control circuit 4. This was performed only by the control circuit 4, and the thermal recording head drive power source 2 only supplied power to the RAD 1 for thermal recording.

[Problem that the invention seeks to solve]

In a conventional thermal recording type printing device, a print control circuit 3 sends a print signal 5 to a thermal recording head 1 at regular intervals, and simultaneously sends a paper feed signal 6 to a paper feed control circuit 4, thereby controlling printing and paper feeding. Printing operations were performed in synchronization. Therefore, the electric power input per unit time to the thermal recording head 1 depends on the content of print data, that is, the number of operating heating resistors constituting the thermal recording head.

In general, the content of printed data varies depending on the field of application, and with conventional methods, the power consumption of the device fluctuates greatly, causing temporal concentration of power depending on the printed content, and requiring multiple heating resistors to be operated at the same time. High-speed printing and large-sized printing are difficult to implement because they increase the cost of the power supply equipment and the device itself.

[Failure to solve the problem]

In order to solve the conventional problems, the present invention provides a constant current circuit 7
, a capacitor 8, a constant voltage circuit 9, a quantity of electricity monitoring circuit 10, a print control circuit 3', a paper feed control circuit 4', and a thermal recording head 1.

[Effect]

The constant current circuit 7 is connected to a commercial power source, performs rectification and constant current, and supplies power to the capacitor 8 .

The capacitor 8 stores electric power supplied from the constant current circuit 7, and is connected to the constant voltage circuit 9 to supply electric power.

The constant voltage circuit 9 converts the electric power supplied from the capacitor 8 into a voltage required by the thermal recording head 1 and supplies the voltage. Electrical quantity monitoring circuit 10 monitors the quantity of electricity stored in capacitor 8 and notifies it to printing control circuit 3'. The print control circuit 3' sends a print signal 5 to the thermal recording head 1 and a paper transmission signal 6 to the paper feed control circuit 4 based on the notified electrical quantity signal. The thermal recording head 1 performs printing according to the print signal 5. A paper feed control circuit 4 performs paper feed control in accordance with a paper feed signal 6.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, constant current circuit 7 continues to supply a constant current to capacitor 8. When the terminal voltage of the capacitor 8 reaches the maximum voltage, the control signal 11 stops the power supply. The terminal voltage of the capacitor 8 indicates the amount of electricity stored therein. Therefore, since the power supplied from the capacitor 8 to the constant voltage circuit 9 changes depending on the content of the print data, the power capacitor 8
The terminal voltage of is also changing. If the power consumption of the thermal recording head 1 at a certain time is greater than the power supplied from the constant current circuit 7, the terminal voltage of the capacitor 8 drops. or,
In the opposite case, the terminal voltage increases.

The electricity amount monitoring circuit 10 is for monitoring the terminal voltage of the electricity condenser 8, and changes the printing speed according to the stored electricity amount to control the electric power applied to the thermal recording head 1 per unit time. It is something. FIG. 2 shows the relationship between the amount of electricity in the capacitor 8 and the signals of each part. Also, the third
The figure shows the relationship between the amount of electricity and printing speed. In the high-speed printing state shown in FIGS. 2 and 3, when printing data 14 that causes many heating resistors to operate is sent, the power consumption in the thermal recording head 1 increases rapidly, and the power consumption from the constant current circuit 7 increases. As the supply slows down, the amount of electricity decreases as shown in FIGS. 2 and 3, and the terminal voltage of the capacitor 8 drops. When the terminal voltage falls below the deceleration detection level, a deceleration signal 12 is sent to the print control circuit 3. The print control circuit 3' receives the deceleration signal 12.
When this signal is received, the pulse intervals of the print signal 5 and paper feed control signal 6 are increased at a constant rate, and the printing speed is decreased.

Figure 3 shows the relationship between printing speed and amount of electricity. In the example,
As shown in FIG. 3, uniform acceleration and deceleration motion is shown, but the speed function is not uniform depending on the transmission characteristics of the printing mechanism, but in general, uniform acceleration motion is acceptable. If the amount of electricity does not exceed the acceleration detection level during the deceleration operation, that is, the data density of the print data 14 is high (if the power consumption does not decrease, the printing speed is reduced to the predetermined minimum printing speed. The minimum printing speed is determined by the current supply capacity of the constant current circuit 7 and the paper feeding characteristics of the printing mechanism, but is 1/2 to 1/1 of the maximum printing speed.
0 would be appropriate.

When the content of the print data changes during deceleration and low-speed printing and the power consumption in the thermal recording head 1 decreases, as shown in FIG.
As shown in FIG. 3, since the supply from the constant current circuit 7 becomes dominant, the amount of electricity increases. The electrical quantity monitoring circuit 10 whose electrical quantity exceeds the acceleration detection level sends an acceleration signal 13 to the print control circuit 3'. When the print control circuit 3' receives the acceleration signal 13, it decreases the pulse interval of the print signal 5 and the paper feed control signal 6 at a constant rate to increase the printing speed. This means is known for controlling the speed of a stepping motor, etc. It is about.

In this embodiment, as shown in FIGS. 2 and 3, the intervals between control pulses for printing and paper feeding are shown as a uniform acceleration function, but the printing speed is controlled in discontinuous steps. It's okay.

〔Effect of the invention〕

As is clear from the above description, the present invention is characterized in that printing can be performed with constant power, regardless of the content of print data.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an embodiment of the present invention.
Timing diagram showing the relationship between electrical quantity and various control signals, Part 3
The figure is a timing diagram showing the relationship between the amount of electricity and the printing speed, and FIG. 4 is a block diagram showing a conventional example of a thermal recording type printing device. l...Thermal recording head 2...Thermal recording head drive power source 3.3'...Print control circuit 4...Paper feed control circuit 7...Constant current circuit 8...Condenser 9... Constant voltage circuit 10...Electrical quantity monitoring circuit and above Applicant: Seiko Electronics Industries Co., Ltd. Yukimura and Ichiyu Conventional Koinetsu printing process 1 Figure 7 Figure 4

Claims (1)

[Claims] In a thermal recording type printing device comprising a thermal recording head, a printing control circuit, a paper feed control circuit, and a thermal recording head driving power source, the thermal recording head driving power source is a constant current circuit,
1. A thermal recording type printing device comprising an electric condenser and a constant voltage circuit, and further comprising an electric quantity monitoring circuit that monitors the electric quantity stored in the electric condenser and performs printing control and paper feeding control.