JPH04338572A - Control method of space of printer - Google Patents

Abstract

PURPOSE:To improve a printing grade by preventing the generation of mechanical vibrations by sudden acceleration and sudden deceleration. CONSTITUTION:The rotational speed of a motor is detected, and rotational speed detected is fed back and currents fed to a motor are controlled. When a printing head moved in the certain direction is stopped and shifted in the opposite direction, deceleration treatment is conducted first, then, unconditional acceleration is performed, and a set treating region c2 is formed during that time, and the supply of currents is stopped and the free travelling state of the printing head is brought. Unconditional acceleration is carried out, the movement of the printing head is inverted, and a semi-unconditional acceleration region f2 reducing a current value in step and a pre-stage constant-speed control region g2, in which target speed lower than final speed is set, are formed during a time when the printing head is shifted at constant speed by constant speed control.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a space control method for a printer that prints using a print head that moves in space in opposition to a platen.

0002

2. Description of the Related Art Conventionally, in a serial printer, printing is performed by moving a carriage carrying a print head along the axial direction of a platen, and supplying print data to the print head during this period. In order to perform this spacing operation, a slit disk is attached to the motor, and the slits of the slit disk are detected to control the motor.

FIG. 2 is a diagram showing a spacing mechanism of a conventional printer, and FIG. 3 is a diagram showing a speed profile of a conventional printer. In FIG. 2, reference numeral 1 denotes a motor for moving the print head 2 in the left-right direction, and a pulley 4 attached to the end of the rotating shaft of the motor 1 and a pulley 6 attached to the end of the lead screw 5. They are connected by a timing belt 7, and the rotation of the motor 1 is controlled by the lead screw 5.
transmitted to. The lead screw 5 is connected to the motor 1.
The print head 2 is moved in the left and right direction in response to the rotation. 8
is a counter for keeping balance when the print head 2 moves left and right. Therefore, the above lead screw 5
A balance lead screw 9 is fixed to the other end of the balance lead screw 9, and the balance lead screw 9 is threaded in the opposite direction to the lead screw 5. Therefore, at the same time that the rotation of the motor 1 is transmitted to the lead screw 5 and the print head 2 moves, the balance lead screw 9 rotates and the counter 8 moves the print head 2.
and move in the opposite direction.

Reference numeral 11 denotes a control circuit for controlling the rotation of the motor 1. In order to detect the moving speed of the print head 2, a slit disk 12 and a sensor 13 for detecting the slits of the slit disk 12 are attached to the rear of the motor 1. The sensor 1
3 is sent to the control circuit 11, and the rotational speed of the motor 1 is controlled to obtain a speed profile as shown in FIG.

FIG. 3 shows the process when the print head 2 is switched from a deceleration state to an acceleration state, that is, when the print head 2 moving in one direction is moved in the opposite direction. The time is plotted on the vertical axis, and the speed is plotted on the vertical axis. A1 and b1 in the figure indicate the first and second deceleration processing areas, and at this time, while the print head 2 is moving, a current is applied to the motor 1 in the opposite direction to brake the motor 1, and the print head 2
I'm trying to stop it.

[0006] In the deceleration processing regions a1 and b1, currents of different current values are passed different times. c1 is an unconditional acceleration region, in which the maximum current within the allowable range depending on the conditions of the motor 1 and the circuit is passed a certain number of times. d1 is the overshoot processing area,
A current lowered to a certain value is passed a certain number of times. e1
is a constant speed region, and the motor 1 changes according to the output of the sensor 13.
The moving speed of the print head 2 is kept constant by changing the current value applied to the print head 2.

[0007]

However, in the conventional printer space control method described above, when high-speed printing is performed, the acceleration time at startup is set short, so the moving speed of the print head 2 cannot be stabilized. Furthermore, mechanical vibrations occur, making it difficult to print with a set time period.

[0008] Furthermore, when using the multi-head system,
The weight of the print head becomes considerably large, the acceleration during acceleration and deceleration becomes considerably high, and mechanical vibration becomes large. When speed control is performed under these conditions,
At the rising portion of the movement speed, overshoot occurs, and mechanical vibrations occur due to sudden acceleration and deceleration when the direction of the print head 2 is reversed, causing disturbances in printing.

The present invention solves the problems of the conventional printer space control method described above, and eliminates mechanical vibration due to overshoot at the rising edge of the moving speed and sudden acceleration and deceleration when reversing the direction of the print head. An object of the present invention is to provide a space control method for a printer that can prevent the occurrence of the problem and improve printing quality.

0010

[Means for Solving the Problems] To solve the problem, the present invention provides a printer in which the motor is rotated by supplying current and the rotation is converted into linear motion to move the print head left and right. The rotational speed of the motor is detected, and the detected rotational speed is fed back to control the current supplied to the motor.

When the print head moving in a certain direction is stopped and moved in the opposite direction, the current supply is stopped while the print head moves from the deceleration processing area to the unconditional acceleration area and the print head is allowed to move freely. An enactment processing area is provided to create the state. In addition, while moving from the unconditional acceleration area to the constant speed control area, a semi-unconditional acceleration area where the current value is reduced in stages and a preliminary constant speed control area where the target speed is set lower than the final speed are provided. ing.

0012

[Operation] According to the present invention, in a printer in which the motor is rotated by supplying current as described above and the rotation is converted into linear motion to move the print head left and right, the rotation of the motor is as follows. The speed is detected, and the detected rotational speed is fed back to control the current supplied to the motor.

[0013] When a print head moving in a certain direction is stopped and moved in the opposite direction, deceleration processing is first performed and then unconditional acceleration is performed. The supply of water is stopped to create a free running state for the print head. At this time, the print head moves freely due to inertia. In addition, after performing unconditional acceleration and reversing the movement of the print head, constant speed control is used to move the print head at a constant speed. A preliminary constant speed control area is provided in which a target speed lower than the current speed is set.

[0014]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a speed profile according to the printer space control method of the present invention. The printer space control method of the present invention can be implemented using the spacing mechanism shown in FIG.

In the figure, a2 and b2 are the first and second
This shows the deceleration processing area of the print head 2 (
(See Figure 2)
The motor 1 is braked to stop the print head 2. In both deceleration processing regions a2 and b2, currents of different current values are passed different times.

c2 is an established processing area, in which the supply of current is temporarily stopped after the above-mentioned deceleration processing areas a2 and b2, a free running state is created due to the inertia of the print head 2 itself, and a sudden reversal of direction is performed. are avoiding. Subsequently, in the first unconditional acceleration region d2, the maximum current within the allowable range depending on the conditions of the motor 1 and the circuit is passed a certain number of times. The second unconditional acceleration region e2 is a control after the motor 1 starts rotating, and requires less current than when starting up from a stationary state. Therefore, a current smaller than that in the first unconditional acceleration region d2 is made to flow for a certain period of time. In this manner, in the semi-unconditional acceleration region f2 after the first and second unconditional accelerations have been performed, a process is performed to lower the current value in stages in order to prevent overshoot in the rising portion. The current value to be lowered stepwise and the number of times can be set arbitrarily.

g2 is a pre-stage constant speed control region, that is, a first stage constant speed control region, and is designed to have a target speed lower than the final speed in order to prevent overshoot. h2 is the second stage constant speed control region, in which the final speed is the target speed. In this way, by setting the constant speed control region to two stages, the speed of the print head 2 is made to quickly reach a constant value. Also, in the first stage constant speed control region g2, the target speed and the time period of the region can be set arbitrarily.

By the way, in the printer with the above configuration,
There are cases where the print head 2 that is moving in a certain direction is moved in the opposite direction to perform continuous operation, and cases where the print head 2 that is moving in a certain direction is stopped. Therefore, in order to control the rotation of the motor 1 under the same conditions in any operation, an establishment processing area c2 and a stop processing area i2 are provided and can be switched.

FIG. 4 is a time chart in the case where the stop processing and the establishment processing can be switched. As shown in the figure, after being decelerated in the first deceleration processing area a2 and the second deceleration processing area b2, it enters the establishment processing area c2 as described above during continuous operation, but stops during single-shot operation. Enter processing area i2. In this case, current is applied until the moving speed of the print head 2 becomes 0, and the print head 2 stops after a certain distance.

FIG. 5 is an operational flow chart of the space control method of the present invention, and FIG. 6 is a time chart of the space control method of the present invention. In FIG. 6, A is the edge signal of the slit disk 12 obtained by the sensor 13 (see FIG. 2), and B is the current flowing through the motor 1. The timing of forming the edge signal A and the timing of the current sent to the motor 1 are synchronized, and the speed of the motor 1 is changed by changing the duty ratio of the signal B.

In the constant speed control region before entering the first deceleration process, the time between each pulse of the signal A is measured, and the motor 1 is driven at a duty ratio corresponding to the time. Note that the present invention is not limited to the above embodiments,
Various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0022]

As described in detail above, according to the present invention, during the transition from the deceleration processing region to the unconditional acceleration region, there is an established processing region in which the supply of current is stopped and the print head is made to run freely. As a result, the direction of movement of the print head does not suddenly reverse, and it is possible to prevent mechanical vibration from occurring in the print head.

Furthermore, while moving from the unconditional acceleration region to the constant speed control region, there is also a semi-unconditional acceleration region in which the current value is reduced stepwise, and a pre-stage constant speed control in which a target speed lower than the final speed is set. Since the area is provided, it is possible to prevent overshoot from occurring.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a speed profile according to the printer space control method of the present invention.

FIG. 2 is a diagram showing a spacing mechanism of a conventional printer.

FIG. 3 is a diagram showing a speed profile of a conventional printer.

FIG. 4 is a time chart in a case where it is possible to switch between stop processing and establishment processing.

FIG. 5 is an operation flowchart of the space control method of the present invention.

FIG. 6 is a time chart of the space control method of the present invention.

[Explanation of symbols]

1 Motor 2 Print head a2 First deceleration processing area b2 Second deceleration processing area c2 Establishment processing area d2 First unconditional acceleration area e2 Second unconditional acceleration area f2 Semi-unconditional acceleration area g2 First stage determination Speed control area h2
2nd stage constant speed speed control area i2 Stop processing area

Claims (1)

[Claims] 1. A space control method for a printer that detects the rotational speed of a motor for moving a print head, feeds back the detected rotational speed, and controls the current supplied to the motor, comprising: (a) a deceleration processing area; An established processing area is provided during which the current supply is stopped and the print head is placed in a free running state during the transition to the unconditional acceleration area, and (
b) During the transition from the unconditional acceleration region to the constant speed control region,
A space control method for a printer, characterized by providing a semi-unconditional acceleration region in which a current value is reduced stepwise, and a preliminary constant speed control region in which a target speed lower than the final speed is set.