JPS5878789A - Serial printer - Google Patents

Abstract

PURPOSE:To easily detect the deviation of print in a serial printer for raising the reliability of printing by utilizing specific outputs from an up-down counter to count driving pulses to a stepping motor for moving a carrier. CONSTITUTION:A carrier 3 is set in place on the left side of a platen 6, the count of an up-down counter 7 is zeroed (initial setting), printing operation is started by the control of a micro program control circuit 1. In this case, printing is made for the first line by a normaly directed drive pulse output from a driving section 2 (the counter 7 is up-counted), and printing is made inversely for the second line by a reversely directed drive pulse (the counter 7 is down-counted). However, when printing is finished for the second line, or when the count of the counter 7 is zeroed (0), a signal is sent from the counter 7 to a comparator 8. When no signal from a sensor 4 is put in the comparator 8 in this case, a warming for the occurrence of the deviation of print is sent out through the control circuit 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial printer that prints by moving a rear wheel using a stepping motor.

In the conventional serial link, when the power is turned on, a stepping motor is driven in the reverse direction to move the carrier toward the initial setting position, and when the sensor detects that the carrier is at the initial setting position, the motor stops driving. Perform initial settings.

After initial settings, the printing operation is started, and the microzologram control circuit controls printing selection, printing, carrier movement, etc. Since the carrier is moved by a stepping motor, when the microzologram control circuit instructs the number of arm pulses corresponding to the amount of movement, the drive section outputs a driving pulse number. Generally, starting from the initial setting position, printing is performed from the rear side by moving the carrier to the right for the first line and to the left for the second line. Therefore, if the nof number that rotates the stepping motor in the forward direction to move the carrier to the right and the number of luths that rotate the stepping motor in the reverse direction and move the carrier to the left are equal, then the first character of the second line can be printed in the correct position. -However, since a stepping motor moves accurately when the input pulse and the rotation of the stepping motor are synchronized, if some kind of failure occurs in the carrier drive mechanism, the number of revolutions will often decrease. By mistake, the carrier may shift from its correct position. Any misalignment of the carrier will disturb all subsequent printing positions. Therefore, the operator must check whether the printing is being performed correctly by monitoring the printing on the paper, which is cumbersome.

An object of the present invention is to provide a serial blink that can monitor the carrier position even when printing from the second line onwards.

The invention! The system includes a stepping motor for moving the carrier, a sensor for determining the initial setting position of the carrier, a drive section for supplying a driving current to the stepping motor, and a drive unit for the stepping motor. In a serial printer equipped with a micrograph control circuit that controls the number of pulses, print selection, printing operation, etc., the number of drive pulses to the stepping motor from the initial setting position is counted, and when the count value is 0. The present invention is characterized in that it includes an up-down counter that outputs an output, and a comparison circuit that outputs an output when the output of the up-down counter and the output of the sensor do not match.

Next, the present invention will be explained in detail with reference to the drawings.

The figure is a block diagram showing one embodiment of the present invention. That is, the micropronoram control circuit 1 gives a signal indicating the number of steps or rotation direction to the drive section 2, and the drive section 2 outputs a drive pulse 10 to drive the stepping motor 11. When the vl power is turned on, the stepping motor 11 rotates in the opposite direction to move the carrier 3 to the left in the figure, and when the sensor 4 detects the initial setting position, the sensor 4 is activated.

The drive section 2 outputs an output 5, and stops outputting the drive nolus. The number of steps corresponding to all members of Graten 6 is set for the up-down carantuff, and the uA of reverse rotation is set.
The count is decremented by 10 during tjh. When the count value of the counter 7 becomes OK and one input of the comparator circuit 8 becomes high level, the output of the sensor 4 becomes high level, and when the output of the sensor 4 becomes high level, the output of the comparator circuit 8 becomes high level. Notifies the microglodallum control circuit l of the abnormality.

Also when the output of the sensor 4 comes out first, the output of the comparator circuit 8 becomes high level. However, at this time, the micronogram control circuit does not judge that there is an abnormality, but when it receives the sensor m force, it sends a reset signal to the carantuff, clears the contents of the counter 7, and completes the initial setting. As described above, it is possible to detect that the carrier 3 does not move normally due to an abnormality in the drive mechanism or the like when the power is turned on. However, the above function
It is not an essential component of the present invention.

After the initial settings, the normal printing operation is started under the control of the microglodulum control circuit 1. All right, print selection.
Printing, carrier movement, etc. are controlled. Their operations are similar to those of the conventional serial blink, so a description thereof will be omitted. However, in this embodiment, the up/down counter 7 counts up by the forward drive/f pulse outputted from the drive unit 2, and counts down by the reverse drive/f pulse. That is, when the stepping motor 11 rotates in the forward direction due to forward direction drive/lls and the carrier 3 moves to the right in the figure, the force ramp value of the counter 7 becomes /
Increases by the number of elbows. At this time, since there is no output from the sensor 4, both inputs of the comparator circuit 80 are at low level), so there is no output from the comparator circuit 8. When the printing progresses and the printing of the first line is completed, the contents of the up/down counter 7 have become a considerable number/down count value.

Next 1. Printing on the second line is started, and the stepping motor 11 rotates in reverse to move the carrier 3 to the left in the figure. At this time, the counter 7 is decremented by the dynamic analogy IOK. When the carrier is accurately moved by the drive nollus, the time when the content of the carantuff becomes @Om and the time when the sensor 9#''11 detects the initial setting position coincide.Therefore, the comparator circuit 8 outputs However, if the movement of the carrier 3 does not accurately correspond to the drive pulse Kfl due to some kind of failure, the output timing from the counter 7 and the sensor 4 do not match, so the comparator circuit 8 outputs an internal input signal. Detects the discrepancy in the microprogram control circuit 1 and notifies the microprogram control circuit 1 of the abnormality. Due to the abnormality of the microprogram control circuit Note that the counter 7 and comparison circuit 8 may be internally provided in the microprogram control circuit 1.

As described above, in the present invention, the drive according to the initial familiarization setting is
The Atsuno down counter is incremented and decremented by the mother pulse, and an abnormality is detected by the discrepancy between the high level output of the Atsuno down counter at the time of θ count and the output of the sensor that detects the initial setting position of the carrier. Since the carrier is configured as follows, the movement of the carrier is driven by
It is possible to detect that the lasing is followed accurately. ! The link operation is made easier and the operator's labor for monitoring print misalignment is reduced.The printing quality and reliability can be improved without glossing over the print misalignment.

[Brief explanation of the drawing]

FIG. d is a block diagram including a partial front view showing an embodiment of the present invention. In the figure, l... microprogram control circuit, 2
...Driver, 3...Carrier, 4...Sensor, 5
...Sensor output, 6...Siraten, 7...Hot!
Down counter, 8...ratio? IIj circuit, 9...
External controller, 10... Drive, 9 Lus. Representative Patent Attorney Sumi 1) Toshi So

Claims (1)

[Claims] A stepping motor for moving the carrier, a sensor for determining the initial setting position of the carrier, a drive unit that supplies the stepping motor with all drive pulses, and a drive unit that controls the number of driving pulses of the stepping motor. In a serial link equipped with a microzologram control circuit that controls control, printing selection, printing operation, etc.
driving the stepping motor from an initial setting position;
The present invention is characterized by comprising an up/down counter that counts the number of 4 pulses and outputs an output when the first count is 0, and a comparison circuit that outputs an output when the output of the up/down counter and the output of the sensor do not match. Serial plink.