JPS5957781A - Controlling system for serial printer - Google Patents

Abstract

PURPOSE:To enable to smoothly print at high speed without any overshooting, by a method wherein when timer interval in feeding printing data is not longer than an interval allowable for continuously printing at a fixed speed, printing is conducted in a fixed-speed controlling system, and when the time interval is not shorter than said interval, printing is conducted in a position controlling system. CONSTITUTION:The time intervals Ti-1, Ti, Ti+1,... in feeding printing data PD are monitored, and when the interval is within a predetermined period (e.g., selected to be a minimum printing interval Ta in a fixed-speed driving system) (t), fixed-speed driving is conducted, and when the time interval is not shorter than the period (t), position control driving is conducted. For example, in the case where the printing data interval is first narrow and the printer is driven in the fixed-speed controlling system but printing data (2) are considerably delayed behind the preceding printing data (1) and the interval Ti+1 becomes not shorter than (t) as shown, printing of the data (1) is momentarily stopped by a position control at time ta.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a control system for a serial printer that prints based on print data from a host device.

Technical background A typeface serial printer used as an input/output device for a computer prints (printed type) as shown in Figure 1.
A wheel 10, a type selection motor I2 that rotates it, a hammer 14 that hits the type to print, a carrier 16 on which these are mounted, a screw shaft 18 that moves the carrier back and forth, a carriage motor that drives dirt, and a motor that moves the carrier back and forth. It consists of a stay shaft 22 that guides the paper, a platen 24, a paper foot motor 26 that drives the platen, and the like. A transducer 2 is attached to the shaft of the type selection motor 12 to determine the rotational position of the type wheel 10, and a transducer 2 is attached to the rotational shaft of the carriage motor 2o to determine the transverse position of the carrier unit 12, 16, etc. In this printer, a paper feed motor 26 rotates the platen 24 to feed paper and select lines, and a carriage motor 2o rotates the screw shaft 1.
Rotate 8 to move the carrier 16 across and select the digit.
The type selection motor 12 rotates the type wheel 10, and when the desired type comes in front of the hammer 14, the hammer is actuated to strike the type and print.

Although not shown, there is an ink ribbon, carbon paper, etc., and paper between the type wheel 10 and the platen 24.

Prior Art and Problems 1ii Selection, that is, selection of the print position within a line, is performed by rotating the carriage motor 20. There are two methods for this. One is to drive the motor 12 at a constant speed determined according to the type selection time from a device (such as a computer).
There is a method in which printing is performed while moving the carrier at the constant speed, and the other method is to move the specified moving object to the carrier, then stop the carrier, and print in this stopped state. It is a method.

m1 constant speed control 11 formulas, l & thought (1 position control ial
+ Power ceremony and leaf. The constant speed control method is suitable for high-speed continuous printing, but if the print take is interrupted, the carrier naturally needs to stop, so stop position control is performed at this time, and the maximum deceleration current is applied to the motor 20. The carrier suddenly stops. When print data is input, the maximum acceleration current is applied to the motor 20, causing rapid acceleration, and when a constant speed is reached, printing is performed, but when the print data is interrupted again, the motor 20 suddenly stops, and thus the motor 20 receives a large acceleration current. Acceleration and deceleration currents flow, making carrier movement uneven, causing oat/shoe I-, poor alignment, shortening the life of the potentiometer 30, loud vibration noise, and high power consumption for control, etc. There is a problem. In this point position control method, the moving distance is given, and the carrier stops when the distance is moved, so even if the moving amount is minute or the movement is intermittent, the desired control can be performed, as described above. Although there are no problems, it is not suitable for high-speed printing because it prints by repeatedly starting and stopping.

Purpose of the Invention The present invention has been made in view of the above points, and it monitors the interval at which print data is input, and when inputting data at short intervals that allow printing using the speed control force method, continues the speed control method. However, when the interval becomes long, the system switches to position control, thereby printing as fast as possible and eliminating circular printing operations without rapid acceleration/deceleration or machining chute.

Composition of the Invention The present invention is a control method for an unreal printer that prints according to print data sent from a host device, in which the interval at which the print data is sent is monitored, and the interval is set to a predetermined value that is allowable for constant speed continuous printing. If the interval is less than a predetermined time interval, printing is performed using a constant speed control force method, and if the interval is longer than a predetermined time interval, printing is performed using a position control method.
Next, this will be explained with reference to the drawings.

Examples of the invention FIG. 2 shows a drive circuit for the carriage motor 20. As shown in FIG.

32 is an amplifier that drives the motor 20; 32 is a differential amplifier that receives the speed command signal st and the actual speed signal S2 and outputs the difference; and 36 is a switch 9). Reference numeral 38 denotes a speed detection circuit which receives the output of the drop meter 30 and outputs a signal S2 indicating the actual moving speed of the carrier 16. These are constant speed control systems that control the motor 20 so that the actual carrier movement speed S2 becomes equal to the aforementioned speed command S1 given from the computer. The position control system includes a position error detection circuit 40, a differential amplifier 42, a dual changeover switch 36, an amplifier 32, a motor 20, and a potentiometer 30.
The position error detection circuit 40 receives a position command, that is, a signal S3 indicating the above-mentioned specified movement amount, and the output of the potentiometer 30, and generates a position error signal S4. via the amplifier 32, and the position error becomes zero. The motor 20 is driven as follows.

The actual speed signal S2 is also input to the differential amplifier 42, but this is for damping. In the present invention, the speed control system and the position control system are switched depending on the interval at which print data is input manually.

First, the relationship between print data and carrier movement will be explained with reference to FIG. 3 for the conventional system. PD is a signal indicating the arrival of print data, PR is a printer ready signal, and P indicates the positional deviation of the carrier. The horizontal axis is the printing target position Po, and L indicates the amount of carrier movement before the next printing position. When the print data is input, the amount of movement of the carrier IJ-1 is determined, and when the carrier starts moving, the positional deviation decreases, so that the deviation I] has a sawtooth shape as shown in the figure. When the positional deviation P decreases below a predetermined value, a printer ready signal is generated, which is transmitted by the host device (
In this example, Ll+MB, -Ito) is sent to prompt the sending of the next print data -1° at time t1. At 1 near t2, the next print data is sent as soon as printer ready (No. 4 is -1 -, specifically, within the time T from printer ready to print completion), but at time 3 near t2, the next print data is sent. is not directly sent to the printer.When the printer becomes ready, the hammer 14 and the like operate so that printing based on the previously sent data is performed at the printing target position ffpo, and when printing is completed, the positional deviation P becomes the next The carry movement amount to the printing position changes to I-, and the crystal difference P decreases by 7 as the carry cart moves.Difference P
When the value becomes less than a predetermined value, the printer outputs the signal Y)R to V.
The operation is repeated. During this time, the carrier is continuously moved, and printing is performed while it is moving.

If the next print data does not arrive even when the printer is ready, as at time t3, the printing based on the data sent previously is completed and there is no next print data, so the printer is stopped. Get into control. That is, when the carry reaches the target position, a large braking current is applied to the data 20, and the carrier 16 suddenly stops, but there is a slight overshoot. This overshoot can be corrected by passing a reverse current through the motor 20 to avoid hacking. After that, when print data is input, the data is rapidly accelerated so as to quickly reach a constant speed, and printing is performed at the next print position, but when the print data is interrupted again by -, an abrupt stop is performed. In this way, the carrier moves intermittently and discontinuously, and as shown in FIG. 3 M+, the motor is supplied with a sudden deceleration and acceleration current that is considerably larger than when the carrier is continuously moved. A is a continuous constant speed driving period, and B is an intermittent driving period.

Therefore, in the present invention, as shown in the fourth circle].

Immediately, in order to perform continuous constant speed side fl'Ill, the next print data must be input within the time 'F' from when the printer becomes ready until printing is performed, and if it is not input within this time 1' is the above-mentioned intermittent operation, so in this case, switch to position side (J(1).LJ print data P I
) is sent during the time interval 1'i-I, Ti.

1' i-+1. . . . is monitored, and if it is within a predetermined time t (for example, this is selected as the minimum print interval 1'a in the constant speed drive method), the constant speed drive is performed, and if it is longer than the specified time, the position is Control. In the example shown in Fig. 4, the print data interval of LJ was narrow at first, and printing was performed using a constant speed control method, but the print data ■ was considerably delayed from the print data D of fff, and the interval 1' i 41 was Since the above time has passed, printing of data (D is performed by position control at time ta, and the appearance becomes 11-), and then the printed data
This is also an example in which the distance between the next print data and the next print data is 1" i→2 is large, so printing is performed by position control. Position control is as described above by setting the movement m to the next print position to the reference value and the current value. Since the control is performed using servo control using the position as a feedback indicator, there is no need to stop due to a large braking current, or to over-drive.In this way, according to this control, when printing data is sent one after another, it is possible to print at a constant speed of 11. In addition, when print data is sent intermittently or interrupted, the position control method (311) can be performed smoothly without overshooting.

Note that in order to perform this control, it is necessary to know whether the data following the data to be printed will be delayed, and for this, the -1- position device should notify the blink-1 or set up a buffer. It is necessary to take measures such as delaying printing by one cycle. For example, if you do not know the delay of the next data,
In the figure, printing at time ta is performed using the same constant speed method because the print data 0 has arrived within the time, or because the data ■ has arrived within the allowable time after lowering the printer ready PR. When printing is finished, there is no more data, resulting in sudden stops, overshoots, etc. However, if there is an intermittent take after that, position control will be performed because no data has been input within the permissible time, and desired control will be performed.

FIG. 5 does not show the control flow when a buffer is provided.

When data ■ is input, it is stored in a buffer and time t
Start a timer that calculates the number of . When the time-up of type 7 occurs, it is checked whether the next data (2) has been input, and if YES, the constant speed control force type is used, and if No, the position control force type is used.

Advantages of the Invention As described above, according to the present invention, it is possible to control the printer by controlling the printing speed in an OJ manner, ilf + manual and lh, without the need for a key 2t-rear drive.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the outline of a type serial printer;
Fig. 2 is a block diagram showing an overview of the control system, Fig. 3 shows the conventional control force formula, and Fig. 4 shows the control force formula of the present invention.
Char 1., FIG. 5 is a flowchart of the control method of the present invention. In the drawing, 20 is a carrier drive motor, 3o, 3B, 34
．． 36.32 is constant speed control system, 3o, 40.42, 36
．． 32 is a position control system. Applicant Fuji if! Representative Patent Attorney Co., Ltd. Minoru Aoyagi 0 Figure 21 14 Figure 3 tl t2 t3i-1-□吋-
□□□□□T1--Medium-Ti++ □□□□□4-
TI + 2 Do 11-11 CI

Claims (1)

[Claims] In a control method for a serial printer that prints according to print data sent from a host device, the interval at which the print data is sent is monitored, and if the interval is less than a predetermined time interval allowed for constant speed continuous printing, constant speed control is performed. A control method for a serial printer, characterized in that printing is performed by a position control method if the interval is a predetermined time interval or more.