JPH0611561B2 - Step motor controller for paper feeder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control system when a step motor is used as a paper feed control used in a printer such as a typewriter.

<Prior Art> In a paper feeding device generally used in a typewriter, in order to hold the paper feeding position after paper feeding, the stop position of the step motor (motor for driving the paper feeding) is kept. But I had to keep the current flowing.

This is because the printing position is displaced when tension due to disturbance acts on the recording paper during printing.

Therefore, conventionally, a voltage was applied as shown in FIGS. 1 and 2 when the step motor was stopped. In FIG. 1, the same current and voltage as during operation are applied during the stop period of the step motor, and in FIG. 2, the same current and voltage as during operation are applied at the initial stage of stop, and then the current and voltage are changed. It was applied in the lowered state.

However, there is a problem that if the motor is stopped and it is energized by the constant operation, it may cause heat generation or damage to the motor, and if the energized current is lowered, the paper easily shifts due to disturbance and the printing position shifts. It was

<Objective> The present invention does not apply a current or voltage during operation that would cause heat generation or damage to the motor when the step motor is stopped, and even if the paper is slightly displaced due to disturbance,
The paper misalignment can be corrected to a regular position during printing.

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

In the figure, 10 is a printer controller, which is not shown in the figure, but controls character type selection (for example, wheel rotation control in the case of a daisy wheel printer), print control, ribbon feed control, etc. based on input data. Is.

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

In the case of printing control, data indicating ribbon shift (up) is output to the ribbon shift circuit prior to printing.

The feed control circuit 20 outputs pulses corresponding to the feed amount via l ₄ according to the feed amount. Also l
_A "1" signal is supplied to the gate OR via ₂ .

Reference numeral 21 is a counter for counting the 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 which is a gate circuit group.

This is because the feed control circuit 20 receives the output of the counter 21 and detects that the motor described later has reached the position corresponding to the feed amount.

Reference numeral 23 denotes a step motor, and one of the windings is supplied with a relatively high voltage V ₂ supplied when the step motor 23 is rotated or V ₁ lower than the above-mentioned V ₂ for holding, via a switch circuit 24. A driver 25 (a switching circuit for grounding) is connected to the other side of the step motor 23.

When the switch circuit 24 receives the "1" signal from the gate OR, it supplies the power of + V ₂ to the step motor 23, and when it receives the "0" signal, it supplies the power of + V ₁ to the step motor 23.

Further, the driver 25 includes A, B, and
The C and D pulses are supplied, and the A to D pulses are 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 set the output of the flip-flop F ₁ of the input to the set terminal also the flip-flop F ₁ is input to the D terminal of the flip-flop F ₂ of type D. A pulse (clock pulse) having the same period as the above l ₄ is input from the feed control circuit 20 to the C terminal of the flip-flop F ₂ via l ₁ , and is set in synchronization with the pulse. The set output of the flip-flop F ₂ is the gate O
Through R are introduced to the reset terminal of the introduction into the "1" signal to the switch circuit 24 also flip-flop F _1.

Therefore, the flip-flop F ₁ is set in response to the ribbon shift signal output when printing, and the flip-flop F ₂ is set in synchronization with the clock pulse from l ₁ to output the set output “1”. Is supplied to the switch circuit 24 and the + V power is supplied to the step motor 2
Supply to 3. The output of the flip-flop F ₂ is the fourth
It corresponds to the signal in the example of the figure.

The operation of FIG. 3 will be described with reference to the time charts of FIGS. 4 and 5. Further, FIG. 5 shows each exciting coil (A, B, C,
6 is a time chart of the voltage supplied to the stop exciting coil C in the stopped state, in particular, in the voltage supplied to D). Therefore, it is assumed that the step motor 23 first stops in response to the phase of the pulse of the coil C in order to stop the step motor 23 at the position of the exciting coil (C) from the phase circuit 22. At this time, the switch circuit 24 holds + V for holding.
The power of No. ₁ is supplied, and the state shown in FIG.

Here, when the ribbon shift signal (shift up) is output from the controller 10 of the printer for printing as shown in FIG. 5A, the flip-flop F ₁ is set and the flip-flop F ₂ is controlled to be fed. Circuit 20
Is set in synchronism with the clock signal input via the input terminal ₁ to l ₁ .

The set output of the flip-flop F ₂ is supplied to the switch circuit 24 as a “1” signal via the gate OR. In response to this, the switch circuit 24 supplies the power of + V ₂ to the step motor 23, and the state shown by E in FIG. 5 (2) is obtained.

Further, in order to reset the flip-flop F ₁ on the set output of the flip-flop F _2, then resets the flip-flop F _2, "1" output to the switching circuit 24 is stopped.

The state indicated by E is a power supply of + V ₂ when the step motor 23 is rotationally driven, and the paper is pulled by a disturbance when the power of + V ₁ for holding is supplied. Even if occurs, the phase is corrected to the "C" phase in the stopped state by the + V ₂ power supply before the printing. Therefore, it is lower than the holding voltage (a voltage equivalent to the drive voltage V ₂ at the time of feeding the paper) for eliminating the positional deviation immediately before the printing operation and stopping and holding the step motor 23 after a certain time, as shown in FIG. The printing operation is started in the state where the stopped state is held at the holding voltage V ₁ . Therefore, when starting the printing,
Before the printing, the paper is corrected to the regular position in advance and then held at the holding voltage V _1. Therefore, during the printing, the correction feed of the paper is not performed by the voltage switching, and the paper does not shift at the same time as the printing. The printing can be performed normally, and at the same time, the printing can be performed at the proper position.

Incidentally, just before the above embodiment has been from the flip-flop F ₂ using the ribbon shift signal is "1" output to the switch circuit 24, which can also be utilized print selection signals, etc., in short printing operation is performed In addition, the "1" output from the flip-flop F ₂ may be guided to the switch circuit 24.

<Effect> In the step motor control method of the sheet feeding device of the present invention described above, when the step motor that performs the sheet feeding drive is stopped, the same current and voltage as during the driving are not supplied during the stop period. There is no problem of heat generation or destruction. Also, when the motor is stopped, a lower holding current and voltage are supplied than when driving, but at this time some disturbance due to disturbance occurs. Even if occurs, the deviation can be corrected by applying the same current and voltage to the step motor just before the printing operation for a certain period of time immediately before the printing operation, and when the printing starts, the sheet holding voltage V ₁
Since the printing is performed in the state of being held at, the voltage is not switched during printing and the correction feed of the paper does not occur, and the printing distortion does not occur due to the paper misalignment at this time and the normal printing is performed at the same time. The feature is that printing can be performed at an appropriate position on the static paper.

[Brief description of drawings]

1 and 2 are time charts showing a conventional paper feed drive operation, FIG. 3 is a block diagram showing a control circuit configuration of a control system according to the present invention, and FIG. 4 is a pulse of a phase circuit output in FIG. And FIG. 5 is a time chart showing the control operation of FIG. 10: printer controller, 20: feed control circuit,
21: counter, 22: phase circuit, 23: step motor, 24: switch circuit, 25: driver, F ₁ and F ₂ : flip-flop.

Claims (1)

[Claims] 1. A sheet feeding device for feeding a sheet of a printer by a step motor, wherein a holding voltage V ₁ lower than a drive voltage V ₂ for feeding the sheet is fed to the step motor when the feeding of the step motor for feeding the sheet is stopped. In the step motor controller of the paper feeding device of the printer that supplies and stops feeding the paper and holds it, and starts the printing operation in this stopped state, immediately before the printing operation by the printer starts Voltage V ₂ when driving when feeding paper
While the holding voltage that is the same as the holding voltage is supplied to the step motor after the fixed time, the step holding voltage V ₁
A step motor control device for a paper feeding device, characterized in that a voltage switching control means for supplying the above voltage is provided, and the printing operation is started in a stopped state of the paper to which the holding voltage V ₁ is supplied after the fixed time.