JPS60157881A - Printer controlling system - Google Patents

Abstract

PURPOSE:To prevent a DC power source voltage from varying in the case where dot duty is heavy, by a method wherein a power source current is integrated over the course of printing a line, and when the integrated value exceeds a predetermined value, the start of printing in the next line is suspended for a period of time corresponding to the excess amount. CONSTITUTION:An output current from a rectifying circuit 1 is converted into a voltage signal by a current-detecting circuit 2, and the voltage signal is treated by an integrating circuit 4 to produce an averaged signal of the power source load current. A comparator 6 discriminates whether or not the averaged signal exceeds a reference current value 5, and when the signal exceeds the reference current value 5, the start of printing in the next line is inhibited by a printing-inhibiting signal (a). Accordingly, a power source board can be prevented from being heated to a high temperature due to overload, and the entire body of the device can be prevented from being overheated.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a printer control system, and more particularly to a print control system for a dot printer.

In the prior art dot printing, the load current supplied from the stain source board varies greatly depending on the printing pattern. When the dot duty (the number of dot positions actually printed for all dot numbers) is negative, the load current increases and the DC power supply voltage decreases. In order to prevent such a voltage drop, it is necessary to increase the capacity of the power supply, which has the disadvantage of being expensive and large.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a printer control system that does not cause fluctuations in the DC power supply voltage even when the dot duty is large and allows a compact power supply panel.

Jv1q Toyonari The printer control method according to the present invention determines the magnitude of the dot duty by integrating the power supply current during printing one line, and if this integrated value exceeds a predetermined value, the printer control system prints the next line for a time corresponding to the amount exceeded. It is characterized by delaying the start of printing.

Example Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, and shows a block diagram for issuing a print prohibition signal. The output current of the rectifier circuit 1 is supplied to a switching regulator 3 which is a power supply for the printer.
However, by converting this current into a voltage signal by the current detection circuit 2 and passing it through the integration circuit 4, a power supply load current averaging signal is created. A comparator 6 determines whether this current averaged signal exceeds a certain reference current value 5, and a print prohibition signal is generated.

The printer (not shown) looks at the print inhibit signal, and if it is at the low level, it starts printing one line and continues printing until the printing of that line is completed.The dot duty of that line is If the value is high, the print prohibition signal goes to the ``...'' level during printing. The print prohibition signal is °°...
Since printing of the next line does not start while the level is "A", the load current decreases.Therefore, the current averaging signal, which is the output signal of the integrating circuit 4, also decreases with the passage of time and becomes less than the reference current value 5. When the value reaches , the print inhibit signal, which is the output signal of the comparator 6, returns to the "low" level. The printer starts printing the next line after recognizing that the print prohibition signal has gone to the "low" level.

By doing this, when a large amount of load current is drawn from the power supply panel, printing can be paused in proportion to the amount of load current taken, preventing the power supply panel from becoming too hot due to overload, and printing. It is also possible to prevent a rise in temperature of the entire device including the head, driver, etc.

FIG. 2 shows a time chart of this embodiment. Every time one line is printed, a load current flows according to the dot duty, and a print prohibition signal is generated by comparing the integrated value of the load current with a reference current value. Printing of the next line is not started during the hatched portion of the print prohibition signal in the figure.

FIG. 3 is a circuit diagram showing a specific example of the block in FIG. 1, in which the power supply load current flowing through the resistor Ro is detected by a current detection circuit 2 having an operational amplifier (operational amplifier) 7 and converted into a voltage. . And resistance RI.

An analog integration circuit 4 consisting of R2, a capacitor CI, and an operational amplifier 8 creates a load current averaging signal. This averaged signal and a reference value 5 are compared in a comparator 6 consisting of an operational amplifier 9, and if the averaged signal is larger than the reference value, a "high" level print prohibition signal is output. .

The control unit of the printer (not shown) determines the state of the print inhibit signal before starting printing one line, and keeps the print inhibit signal at the "high" level until the next line returns to the "10-" level. Delays the start of printing.

Effects of the Invention According to the present invention, since the integral value of the load current is determined to control the print start time of the next line, the power supply can be made smaller and the temperature rise of the power supply and the temperature of the entire device can be reduced. This has the advantage of preventing

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a time chart showing the operation of the device shown in FIG. 1, and FIG. 3 is a circuit diagram of a specific example of the device shown in FIG. Explanation of symbols of main parts 2...Current detection circuit 4...Integrator circuit 5...Reference value setting circuit 6...Comparator applicant NEC Corporation representative Patent attorney -m- Shin Yanagawa

Claims (1)

[Claims] This is a control method for dot printers that integrates the power supply current while printing one line, and if this integrated value exceeds a predetermined value, the start of printing the next line is delayed by a time corresponding to the amount exceeded. Features printer control method.