JPS59214676A - Control system for step motor of paper feeder - Google Patents

Abstract

PURPOSE:To obtain a step motor control system capable of preventing the breakage of a motor and also of correcting the bias of paper by using a system in which a low-holding power source is supplied when a step motor to driving a paper feeder is stopped, and immediately before the printing operation, the same power source as during the operation is supplied only for a fixed period of time. CONSTITUTION:When feeding by a step motor 23 is stopped, lower power source V1 current and voltage for holding than the power source V2 during the operation is supplied to the motor to avoid the heatup or breakage of the motor. Immediately before the printing operation of the printer, the power source V2 current and voltage for the operation of the motor is supplied to the motor only for a fixed period of time, and the bias of paper caused by external disturbance. Therefore, printing can be made on proper positions.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a control system in which a step motor is used to control sheet feeding in a printer, such as a typewriter.

<Prior art> In paper feeding devices generally used in typewriters, in order to maintain the paper feeding position after paper feeding, the step motor (motor for driving paper feeding) is It was necessary to keep the current flowing even at the stopped position.

This is because when tension due to disturbance acts on the recording paper during printing, the printing position may shift. Therefore, in the past, when the step motor was stopped, a voltage was applied as shown in FIGS. 1 and 2. In Fig. 1, the same current and voltage as during operation are applied during the step motor's stop period, and in Fig. 2, the same current and voltage as during operation are applied at the beginning of the step motor's stop, and then the current and voltage are applied. The conventional method was to apply the voltage with the voltage lowered.

However, when the motor is stopped, the same current is applied as when it is constantly operating.

If this is done, there are problems such as heat generation or destruction of the motor, and if the applied current is lowered, the paper will easily shift due to disturbances, causing misalignment of the printing position.

Purpose of the present invention The present invention is designed to prevent current during operation that may lead to heat generation or destruction of the step motor when it is stopped.

Even if the paper is slightly shifted due to disturbances, the paper shift can be corrected to the normal position during printing without applying any voltage.

<Embodiment> FIG. 3 is a block diagram of a step motor drive control circuit according to the present invention.

In the figure, reference numeral 10 denotes a printer controller, which is not shown, but controls type selection (for example, wheel rotation control in the case of a decimal wheel printer), printing control, ribbon feeding control, etc. based on input data. It is something.

When controlling the paper feed, data on the feed amount is supplied to the feed control circuit 20.

When controlling printing, data indicating ribbon shift (rise) is output to the ribbon shift circuit prior to printing.

The feed control circuit 20 outputs pulses corresponding to the feed amount via t4 in accordance with the feed amount. Also t
A XX1 // times signal is supplied to the gate OR via the gate OR.

21 is a counter that counts pulses from the feed control circuit 20, and the output of the counter 21 is supplied to the feed control circuit 20 and also to a phase circuit 22 consisting of a group of gate circuits.

The feed control circuit 20 receives the output of the counter 21 and detects when a motor, which will be described later, has reached a position corresponding to the feed amount.

Reference numeral 23 denotes a step motor, and one of each winding is supplied with a relatively high voltage v2, which is supplied when the step motor 23 rotates, or a voltage Vl, which is lower than the above-mentioned v2, for holding, through a switch circuit 24.

A driver 25 (switching circuit for grounding) is still connected to the other side of the step motor 23.

The above-mentioned switch circuit 24 is connected from the gate OR to SS 1
//When the double signal is received, the +v2 power is applied to the step motor 23
When the step motor 23 receives the 10 signal, +V+ power is supplied to the step motor 23.

Still, the driver 25 receives signals A, B, from the phase circuit 22.
Pulses C and D are supplied, and this pulse A-D is the fourth pulse.
The signal is as shown in the figure.

On the other hand, the ribbon shift signal output from the controller 10 described above is input to the set terminal of the flip-flop F1, and the set output of the flip-flop F+ is input to the D terminal of the D-type 7-lip 70-tube F2. A pulse (clock pulse) having the same period as t4 described above is input from the feed control circuit 20 to the C terminal of the Noritub flop F2 via tl, and is set in synchronization with the pulse. The set output of this flip-flop F2 is
The X1'' signal is introduced into the switch circuit 24 via the OR, and is also introduced into the reset terminal of the Noritsu flop F1.

Therefore, the flip-flop F1 is set in response to the ribbon shift signal output when printing, and the seven flip-flop F2 is set in synchronization with the clock pulse from tl, and the set output 11 is sent to the switch circuit. 24, and the 10V power is supplied to the step motor 2.
Supply to 3. The output of the flip-flop F2 is the third
In the example shown in the figure, this corresponds to the signal ■.

To explain the operation shown in FIG. 3 together with the time chart shown in FIG.
It is assumed that the stop operation was performed in response to the phase of the pulse C from . At this time, the switch circuit 24 is supplied with the power of +V1 for holding, and enters the state shown in (2) in FIG.

Here, as shown in (1) in Figure 5, the core of the printer is
) When a ribbon shift signal (synthesis) is output from o-ra 10 during printing, flip 70 7'F
+ is set, and the flip-flop F2 is set in synchronization with the clock signal inputted from the transmission control circuit 20 via tl.

A "1" signal from the set output of the flip-flop F2 is supplied to the switch circuit 24 via the gate OR. In response, the switch circuit 24 supplies a power of 10V2 to the step motor 23, and the fifth The state shown by E in FIG. 2 is reached.

Moreover, since the flip-flop F+ is reset by the set output of the flip-flop F2, the flip-flop F2 is then reset and the N1'' output to the switch circuit 24 is stopped.

The state indicated by E above is the +V2 power supply when rotating the step motor 23, and even if the paper is pulled due to disturbance and -1i occurs when the -vl power supply for holding is supplied, the state before printing is S in a stopped state due to +V2 power supply of
The phase is corrected to S C //. Therefore, it is possible to eliminate positional deviation immediately before performing a printing operation and to perform printing at an appropriate position.

In the above embodiment, the ribbon shift signal is used to transfer \X1 / from the flip-flop F2 to the switch circuit 24.
/ specific output, but it is also possible to use a type selection signal, etc. In short, immediately before the printing operation, tt 1 from the flip-flop F2 is led to the specific output switch circuit 24. good.

Effects> In the step motor control method of the paper feed device of the present invention described above, when the step motor that drives the paper feed is stopped, the same current as when the step motor is driven is used.

Since voltage is not supplied during the stop period, there is no problem of heat generation or destruction of the motor. In addition, when the motor is stopped, a lower holding current and voltage are supplied than when the motor is running, but even if some deviation occurs due to disturbances at this time, the same current and voltage as when the step motor is running for a certain period of time immediately before the printing operation is supplied. It has the feature that by applying an electric current to the ink, the deviation can be corrected and printing can be performed at an appropriate position.

[Brief explanation of the drawing]

1 and 2 are time charts showing the conventional paper feed drive operation, FIG. 3 is a block diagram showing the control circuit configuration of the control method according to the present invention, and FIG. 4 is the pulse of the phase circuit output in FIG. 3. FIG. 5 is a time chart showing the control operation of FIG. 3. 10: printer controller, 20: feed control circuit,
21: Counter, 22: Phase circuit, 23: Step-by-step circuit, 24: Switch circuit, 25 Nidry/N,
F1 and F2: flip-flops.

Claims (1)

[Scope of Claims] 1. In a paper feeding device that uses a step motor to feed paper in a printer, when the step motor that feeds the paper stops feeding, a Vl power supply for holding, which is lower than the power supply V2 during this drive, is supplied to the motor. 1. A step motor control method for a paper feeding device, characterized in that the step motor control method for a paper feeding device is characterized in that the power supply V2 for driving the motor is supplied for the motor driving time immediately before the printing operation of the printer.