JPS5925658Y2 - Print paper drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a printing device that uses a sprocket to advance lines of printing paper.

Conventionally, a printing device shown in FIG. 1 is known that uses this type of sprocket system for line feeding.

That is, the pawl 2 provided on the sprocket 1 is fitted into the hole 4 of the printing paper 3, and the sprocket 1 is rotated by the pulse motor 5.

The rotational force of this pulse motor 5 is applied to the belt 7 on the take-up roller 6.
The printing paper 3 is moved upward with the rotation of the pulse motor 5 by the rotational force of the sprocket 1 and the rotational force of the take-up roller 6, thereby performing line feeding.

FIG. 2 shows an explanatory diagram of this state.

The claw 2 contacts the upper end of the hole 4 of the printing paper 3 and rotates upward, and the printing paper 3 is rotated by the rotational force of the take-up roller 6 and the sprocket 1.
It moves upward due to the rotational force of.

Therefore, when the line feeding is completed and the pulse motor 5 is stopped, the claw 2 remains in contact with the upper end of the hole 4.

However, in reality, the belt 7 that was transmitting the rotational force to the take-up roller 6 still has a force that pulls the printing paper 3 upward, and this contractile force causes it even after the pulse motor 5 stops feeding the line. The print paper 3 is wound upward little by little due to the shock of each print after a line feed, and the residual contractile force of the belt 7 gradually decreases, and after several times of printing, the print paper 3 is moved upward.
As shown in the figure, when the lower end of the hole 4 comes into contact with the pawl 2 of the stopped sprocket 1, the contraction force of the belt 7 at this time is no longer enough to move the printed paper 3, and the There will be no further movement and it will stop.

During this time, printing is performed sequentially at fixed positions relative to the platen, so in such conventional reciprocating printing devices, the fourth
As shown in the figure, there is a drawback that oblique printing is performed.

The present invention improves this point, and after the end of the change action,
To provide a printing paper drive device which can prevent unnecessary movement of a recording paper after the end of a reversing operation and prevent oblique printing by automatically reversing a motor by a certain number of times.

The present invention consists of a take-up roller that winds up printed paper with holes at both ends, a sprocket that has claws that fit into the holes, a belt that transmits the rotational force of this sprocket to the take-up roller, and a belt that rotates the sprocket. In a printing paper drive device including a motor and a drive circuit that drives the motor, after the drive circuit stops the rotation of the sprocket, the sprocket is moved into the gap between the sprocket pawl and the hole. It is characterized in that it is configured to reverse the magnitude by an amount equal to or slightly greater than the magnitude.

An embodiment of the present invention will be described based on the drawings.

FIG. 5 is a block diagram of the main parts of the present invention-embodiment.

The output of the pulse generation circuit 10 is led to a pulse motor 13 via a polarity inversion circuit 11 and an amplifier 12.

Further, the output of this pulse generating circuit 10 is led to a counter 15.

The size of this counter 15 is set to r408J in this example.

The carry output of this counter 15 is the flip-flop 1
It is led to the set terminal of 6.

The output of this flip-flop 16 is led to one input terminal of an inhibition circuit 17 used when the changeover operation is performed continuously.

The output of this inhibition circuit 17 is led to the control terminal of the polarity inversion circuit 11.

The output of the polarity inversion circuit 11 is led to a counter 19 via a diode 18.

The size of this counter 19 is set to "48" in this example.

The carry output of this counter 19 is led to the reset terminal of the flip-flop 16.

Further, the control output of a control circuit (not shown) is led to the reset terminals of the counters 15 and 19 and the input terminal of the inhibiting circuit 17.

FIG. 6 is an operation time chart showing output signals of the embodiment circuit shown in FIG.

FIG. 6A shows the output signal, and FIG. 6B shows the relationship between the claw 2 and the hole 4 at this time.

The characteristic operation of the present invention will be explained using such a circuit configuration.

This embodiment shows a case where the pulse motor 5 is reversed until the pawl 2 of the sprocket 1 contacts the lower end of the hole 4 of the printing paper 3 after the end of the changeover operation.

Now, the number of input pulses to the pulse motor 5 required to move the claw 2 from the lower end of the hole 4 to the upper end is 48 pulses (hereinafter referred to as r48PJ).

), and the number of pulses required for line feeding is 360 pulses (hereinafter referred to as "360P").

). First, the modification behavior will be explained.

In this case, the pawl 2 contacts the lower end of the hole 4 and the sprocket is stopped.

Also, counters 15 and 19, flip-flop 16
has also been reset, and the polarity inversion circuit 11 is also not operating.

In this state, a line feed command is given to the pulse generating circuit 10, and a pulse is output.

This pulse is amplified by an amplifier 12 and drives a pulse motor 13.

This number of pulses is counted by a counter 15.

This counter 15 first counts 48 P for the claw 2 to come into contact with the upper end of the hole 4, and then counts the 36 P required for the line feed.
Count 0P.

This ends the change action. The feature of the present invention lies in the next action.

In other words, the counter 15 is 408 P (48P+36
0 P), the counter output a is given to the flip-flop, and the flip-flop 16 is set.

The signal passes through this flip-flop stop circuit 17 and is applied to the polarity inverting circuit 11 to operate the polarity inverting circuit 11.

At this time, the pulse generation circuit 10 continues to output pulses, and the output pulses after 408P have their polarities inverted by the polarity inversion circuit 11 and are applied to the pulse motor 13.

Therefore, the pulse motor 13 performs a reverse rotation operation.

The pulses with reversed polarity are counted by a counter 19.

When this counter 19 counts 48 P, the counter output C is flip-flopped and the flip-flop 16 is reset.

Therefore, the polarity inversion circuit 11 also stops operating.

This counter output C is also given to a control circuit (not shown) to stop the pulse generation circuit 10.

Furthermore, a reset signal is given to counters 15 and 19 from the control circuit, and counters 15 and 19 are reset.

Due to this reversal action, the claw 2 is reversed to the lower end of the hole 4,
This prevents the printed paper from moving after a line feed.

In addition, when the line feed operation is performed continuously for two or more lines, logic "1" is given to the prohibition circuit 17, and the operation of the polarity inversion circuit 11 is prohibited.

In addition, although the above embodiment shows an example in which the reverse operation is performed until the claw 2 comes into contact with the lower end of the hole 4, the present invention is not limited to this.
It may be of any other size, including up to the lower end of the hole 4 or slightly larger than that.

As explained above, after the improvement operation is completed, the sprocket is reversed in the opposite direction to the paper feeding direction so that the gap between the sprocket pawl and the diameter of the hole in the printing paper becomes larger.

Therefore, when printing is performed sequentially after the sprocket stops reversing and the characters are fed, even if the pawl moves forward little by little due to the residual contractile force of the belt 7, there is a gap between the front end of the pawl and the front end of the hole in the stopped printing paper. As the printing progresses, the gap gradually decreases, completely preventing the printing paper from being fed upwards, and the printing paper is accurately stopped while maintaining the line spacing set for the paper feeding operation. This stop position is accurately maintained even after the stop.

Therefore, oblique printing can be prevented, the printing accuracy and printing quality of the printing device can be significantly improved, and the practical value of the printing device is significantly increased.

Furthermore, the circuit for this purpose is not complicated and the cost can be reduced.

If the present invention is implemented in a reciprocating printing method in which the printing direction is repeated in the opposite direction, this tooth-shaped oblique printing can be prevented and a particularly excellent effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional device. FIGS. 2 and 3 are explanatory diagrams of paper feeding in a conventional device. FIG. 4 is a diagram showing an example of printing by a conventional device. FIG. 5 is a circuit diagram of a main part of the present invention-an embodiment. FIG. 6 is an operation time chart of the above embodiment. 1...Sprocket, 2...Tlaw, 3
...Print paper, 4...hole, 5,13...
...Pulse motor, 6...Take-up roller, 7
...Belt, 10...Pulse generation circuit, 11...Polarity inversion circuit, 12...Amplifier, 15, 19...Counter, 16...
··flip flop.

Claims (1)

[Scope of Claim for Utility Model Registration] A take-up roller that winds printed paper with holes at both ends; a sprocket that has a tab that fits into the hole; a belt that transmits the rotational force of the sprocket to the take-up roller; In a printing paper drive device that includes a motor that rotates a sprocket and a drive circuit that drives this motor, after the drive circuit stops the rotation of the sprocket, the sprocket is moved between the pawl of the sprocket and the hole. A print drive device characterized in that the print drive device is configured to reverse the print by an amount equal to or slightly larger than the size of the gap generated in the print drive device.