JPS59218880A - Spacing speed control method of printer - Google Patents

Abstract

PURPOSE:To reduce the capacity of a power source and to also reduce the lowering in the through-put of printing, in subjecting the detected moving speed of a carriage to feedback control, by also controlling the same by the voltage of a power source supplied to a motor. CONSTITUTION:The speed of a carriage or a carriage driving DC motor 5 is detected by comparing the pulse signal cycle outputted from an A/D converter 6 and an objective cycle and the detected value is fed back to a control circuit 1 to control the spacing apparatus of a printer. At this time, the output voltage of a power source 8 for driving the motor 5 is detected by a voltage detector circuit 9 and the detected result is added to perform control.

Description

TECHNICAL FIELD The present invention relates to a spacing speed control method for a printer.

(Prior Art) A block diagram of the control of a conventional printer is shown in FIG. 1
is the control section, which mainly consists of the CPU, I10 port, timer, etc. 2 is a head drive circuit, and control section 1
A drive current is supplied to the head 3 according to a print signal given from the head 3. 4 is a motor drive circuit, which connects the control unit 1 to the D/A
A drive current is supplied to the motor 5 in response to a control voltage applied through the converter 22. The motor 5 has a built-in speed detector (for example, a slit and an optical sensor), and converts a voltage according to the rotational speed into an analog-digital converter 6 (
(hereinafter abbreviated as an A/D converter), the signal is converted into a signal, and is fed and packed into the control section 1.

The feed pack signal is used for constant speed control and also as print timing for the head 3. 7
is a logic power supply, and its output V, , is mainly used in the control section 1.
is supplied to. 8 is the power supply, and its output ■
1 is supplied to the head 3 via the head drive circuit 2 and to the motor 5 via the motor drive circuit 4. Next, the operating principle of the printer will be explained.

First, the D/A converter 22 is connected from the control unit 1 to the motor drive circuit 4.
A control voltage, which will be described later, is applied through the motor 5, and a control current is applied to the motor 5, causing the motor 5 to rotate. When the motor 5 rotates, a speed signal generated from a speed detector (not shown) of the motor 5 is converted into pulses by an A/D converter 6 and is applied to the control phloem 1. The control unit 1 monitors the output from the A/D converter 6, and when one signal is input, the control unit 1
(hereinafter referred to as decrement timer)
At the same time, the initial timer value (described later) is set and the decrement timer is started, and the next /? By counting the time until the pulse is input, constant rotation is performed at a predetermined speed.

The principle of printing operation will be explained using the flowchart shown in FIG. When the next pulse is input in step A, the control unit 1 reads the above-mentioned timer (direct), and then sets the timer 1 and decrements it to obtain the next pulse cycle. The timer is started. In Stella fB, in order to further control the speed of the motor 5, the control unit 1 starts the timer value obtained by taking the above Hfe, that is, A/D-
The pulse signal period output from the converter 6 and the target period are compared.

Note that the above-mentioned target period is predetermined by the steady rotation speed of the motor 5. An example of the above comparison method is shown in FIG.

In FIG. 3, the vertical axis is the timer value of the decrement timer, and the horizontal axis is the pulse signal period.
OI T'U is the lower limit value, reference value (target cycle), and upper limit value of the d' pulse signal cycle, respectively. b.

c and d are timer values corresponding to 'r, , To, and TU, respectively. 'l'l, + TU is 1゛, for example. 90% and 110%. Now, set the initial timer value a to TU
It can be seen that when the timer value a is decremented in correspondence with the timer value a and the timer value stops at b, the pulse signal period is TLl, that is, the rotational speed of the motor 5 is about 110% of the target speed. Similarly, when the timer value stops at C, the Noyals signal period is T. That is, it can be seen that the rotational speed of the motor 5 is equal to the target speed. Similarly, the timer value is d
(Here, when it stops at d=0), the pulse signal station is
is TU, that is, the rotation speed of motor 5 is about 9 of the target speed.
It can be seen that it is 0chi. Similarly, if the timer value is greater than or equal to b, it is controlled to be b, and if it is less than or equal to O (which does not appear as a timer value), it is controlled to be all O.

Next, in step C, a control voltage corresponding to the above-mentioned timer value is applied to the motor and drive circuit 4 via the control section ID/A converter 22. Here, the motor drive circuit 4 is a circuit that flows a current proportional to the input voltage and control voltage to the motor, as shown in the input/output characteristics shown in FIG. Therefore, in the case of the above-mentioned timer values fOI b to C, the speed is fast and no drive current is required, while in the case of the timer values C to d, the speed is slow, so it is necessary to gradually increase the drive current.

In step C, using the input/output characteristics of the motor drive circuit 4, the timer values c and c are set to control voltages 0(v) to e(v), and e(V) to' (V
) and output it. When the phase signal of the motor 5 is output by the control unit 1, it is possible to reverse the current direction and flow the brake current, so the timer value s C is converted from the control voltage '(V) to e(v). It also becomes possible to output the information.

Finally, in step D, the print signal at the position obtained by the signal input of the A/D converter 6 is given to the head drive circuit 2, and the head drive circuit 2 supplies current to the head 3 to perform printing. be.

Then, in order to perform the next input again, the process returns to Step A and repeats the above-mentioned process.

Conventionally, printers have required a large power source to cover the maximum power consumption. Today, printers are becoming smaller and lighter.
When lower prices, increased functionality, and lower power consumption are required, the power supply capacity is kept as small as possible. Therefore, it is necessary to change the rotational speed of the motor 4 according to the print density of the - line +&. For example, the printing speed is set to 200 cps for normal ASCII character printing, and 100 cps for graphic printing. However, this method has the disadvantage that if even one graphic character is included in the - line, the printing speed will be 100 cps in the graphic mode even if the other printing densities are low. One way to prevent this is for the f171Lf wholesaler 1 to manage the number of dots for one line and determine the printing speed based on the number of recognized dots, but this increases processing time significantly and is therefore impractical. It's coming. Another method is to stop spacing when the voltage of the power supply 8 drops below 1 voltage, wait for the voltage to recover, and then restart spacing. -There is a disadvantage that the put is lowered.

(Object of the Invention) The present invention has been made in view of the above points, and an object thereof is to "minimize the capacity of the power supply;
Furthermore, it is an object of the present invention to provide a spacing speed control method for a printer that can minimize reduction in printing throughput.

(Structure of the Invention) A voltage detection circuit is added to the servo system of the motor steel control 1 of the present invention, and the motor speed is adjusted according to the voltage by monitoring the power supply voltage supplied to the voltage detection circuit. Hiruichi 1] is the one who exercises control. This will be explained in detail below.

(Example) A book diagram of an embodiment of the present invention is shown in FIG.

Components that are the same as before are given the same reference numerals.

In FIG. 5, reference numeral 9 denotes a voltage detection circuit, which inputs the output voltage (V, ) of the Q-war power supply 8 and outputs a voltage according to the fluctuation of the voltage. -As an example, it is constructed by a circuit as shown in FIG. In Figure 6, 12 is an operational amplifier, 13
are diodes, 14 to 17 are resistors, Vll is the power supply voltage, and 2 is the logic power supply voltage. FIG. 7 shows the relationship between the input 〒iL voltage and the output voltage of the voltage detection circuit 90 of FIG. 6.

As shown in FIG. 7, the voltage detection circuit 9 in FIG. The output is 0~VL
(V). However, vP(max)
is the highest output voltage of the 9-watt power supply 8, and the slope of the above straight line is determined by the resistors 14 to 17 in FIG. . Further, the diode 13 in FIG. 6 causes the voltage detection circuit 9 in FIG. 6 to act on the refill point 10 in FIG. 5 only when the power supply voltage VP decreases due to printing with a heavy load. Operate.

No in Figure 9? The operation of the printer as a whole will be explained using a graph of power supply vehicle pressure vP vs. printing speed.

Note that the printing speed in FIG. 9 is set to a speed that is approximately 9 times the average of the blower power supply voltage ripple and speed fluctuation of the motor 5 during printing.

The graph for the conventional servo system is ■, and the / below A(ri) is
? At the voltage of the power source 8, the motor 5 does not rotate due to insufficient torque, and at B(v) and C(v), the motor 5 rotates, but the voltage of the power source #8 is too low, causing the printing to become faint. I had to set the printing speed to a low speed because sometimes the printout did not come out.

In a servo system including the voltage detection circuit 9 of the present invention, the graph becomes like ■. Before printing starts, the voltage of power supply 8 is D.
(V) or more, the motor 5 has a predetermined value of X (c p
s) starts rotating. Even when printing starts, in areas where the printing density is low, the power consumption of D3 is also small, so the voltage of the power source 8 hardly decreases, and the printing speed is maintained at X (cps) to maintain the voltage above D(cps). .

As the printing density increases, the voltage of the power source 8 increases
When the voltage drops between (v) and B (V), the output of the voltage detection circuit 9 acts on the control voltage at the addition point lθ, so the printing speed changes from X (c p s ) to O.
(cps). If the print density returns to low...
Since the voltage of the power supply 8 recovers to D(v) or higher, the motor 5 can also perform continuous operation such as rotating to a rotational speed of X(cps).

FIG. 8 shows the above relationship in the hidden state of the replenishment point 10 in FIG. In FIG. 8(a), ■ is the control voltage, ■ is the output of the voltage detection circuit 9 in FIG. 6, and the solid line signal is the output of the refill point 10, and The output is given to a motor drive circuit 4 to control the speed of the motor 5. Here, printing is performed in time zone A shown in FIG. 8(b), and printing is performed in time zone B, but the printing density is low, so time zones A and B
Now, the voltage V at voltage 8 does not drop that much (
■2≧D(v) in Figure 9) The voltage detection circuit output ■ (from Figure 7, g(v) or more) is greater than the control voltage ■.

Therefore, the stain pressure detection circuit output by diode J3 in Figure 6■
(contact) does not act on the output of the summing point 10, but is given from the control unit 1 via the D/A converter 22).

- Lumi pressure (2) is directly applied to the shimotor drive circuit 4 as the output of the cutting/adding point 10. In addition, as mentioned above, time periods A and B
Then, constant speed control (X (cps)) is performed while changing the control voltage based on the timer 1 clock (that is, if the rotation speed of the motor 5 is fast, the control voltage is lowered F, and conversely, if the rotation speed of the motor 5 is slow, the control voltage is increased). It is. Next, in time zone C, the printing density is not clear υ power supply 8
Voltage ■.

Vp < D (v)) in Figure 9) The voltage detection circuit output ■ (less than g (v) from Figure 7) acts on the output of summing point 10, causing the printing speed to drop below X (cps). do.

Then, the time period C' when the output of the summing point 10 is e(v)
Then, as shown in FIG. 4, when the current supplied from the motor drive circuit 4 to the motor 5 becomes zero, the motor 5 loses its rotational force and enters a balanced state.

Next, during the time period, the voltage of the power supply 8 is restored, and the output of the summing point 10 becomes the control voltage given from the control section 1 via the D/A converter 22.

In addition, in time period A, it is necessary to make the voltage detection circuit voltage slightly higher than the control voltage to prevent the minute voltage changes at the power source 8 from having a full effect on the output at the summing point 10. It's for a reason.

In the first embodiment, when there is insufficient power supply capacity and the voltage of the power supply 8 suddenly decreases, or when the motor 5
If the followability of the voltage-speed characteristics is poor, the motor 5 will stop, resulting in a printing halt state.

This is no different from the conventional stopping of printing due to voltage drop, and does not improve the drop in printing throughput.

In order to prevent printing from stopping, we added a function that stops the feedback by voltage detection circuit 1@9 when the speed of motor 5 decreases to a certain extent, and then controls the constant speed again at low speed. There is peace of mind in trying to revive it. The method will be explained as the 20th 1M chestnut.

FIG. 10 shows an overall block diagram. What is different from the first embodiment is that it has an ON-OFF function. A voltage detection circuit 1 and a line 2 that outputs an ON-OFF signal from the control unit 1.
Everything else is the same except for the addition of .

One row of voltage limit circuits 11 is shown in FIG. 11, and its operating percentage is shown in FIG. 12. In Figure 11, 7,! l,
J91d resistor 20 is an open collector type driver. Components that are the same as those in the first implementation column (FIG. 6) are given the same reference numerals. The voltage limit circuit 11 shown in FIG. 11 operates as shown in FIG. 12 (■) when an ON signal is given to the driver 20 from the control section l, and operates as shown in FIG. 12 (■) when an OFF signal is given. .

The operation of the printer as a whole will be explained using ◯ in FIG. 9. When printing starts and the printing density is low, the power consumption is similar, so there is no drop in the voltage of the power supply 8, and X(c
Maintain a printing speed of ps). As the printing density increases, the voltage of the printer power supply 8 decreases from D(v) to C(v), and the feedback of the voltage detection circuit 11 is applied, so the printing speed becomes X (c p s ) to Y (cps) is the same as in the first embodiment. Higher printing density, voltage detection circuit 1
1 feedback, the printing speed is Y (cps)
It becomes below. In fact, due to speed fluctuations of the tongue 5 due to voltage fluctuations of the ri power source 8, there are cases where the period of the nosolus signal from the A/D converter 6 becomes less than the equivalent of X/1.6 (cps). come.

In that case, the white control circuit 1 turns off the function of the voltage detection circuit 1.
Output the bow to F through signal line 2.

Since the input pressure of the motor drive circuit 4 in this case is the maximum value f(v) of the control voltage as shown by the dotted line in the diagonal line in FIG. 8, the voltage detection circuit When 1 is turned off, constant speed control is restored and 1. The printing speed begins to increase to X (cps). However, when the printing speed exceeds x/16 (cps), the open side 1 part I turns on the voltage detection circuit 1, so the round voltage detection circuit 1 turns on.
The operation of reducing the print correlation by moving the feedback of No. 1 is repeated. Through this repeated operation, the motor 5 can apparently rotate in a balanced manner near Y (cps).

When the printing density returns to low, as in the first implementation 9t1, as the power source 805 voltage is restored, the printing speed also increases to X (
c p s ), and continuous printing becomes possible.・
Furthermore, the voltage vP of the power source 8 further decreases to A(v)
As in the first embodiment 1+, the motor drive current becomes zero and the motor 5 loses its rotational force and enters a balanced state.

In the case of the first embodiment, the processing performed by the control unit 10 may be the same as the conventional one, but in the case of the second embodiment, the pulse signal period input from the A/D converter 6 is a sequence of the reference period. For example 1
When the voltage exceeds 60%, the voltage limit circuit 11 is turned off.
It is necessary to issue a signal, and the motor speed control process in step B of FIG. 2 is different. Next, the speed control process will be explained using the flowchart shown in FIG.

First, in step A, the previously set decrement timer (initial timer value a/) value is read as in the first implementation column, and in step B, the initial timer value is set again and the decrement timer is started. In the second embodiment, the relationship between the timer value and the signal period is set as shown in FIG. FIG. 13 differs from FIG. 3, which shows the same conventional relationship, in that the initial timer value a' is set corresponding to a value that is thicker than the upper limit mil value TU of the pulse signal period. That is, when the timer value becomes 0, the pulse signal period is the reference value T. It can be seen that the rotational speed of the motor 5 is approximately 60% of the target speed. Next, in step C, it is determined whether or not the timer 1 count is 0. If the timer value is -0, the process proceeds to step E, where an OFF signal (logical 0) is applied to the driver 20 of the voltage limit circuit 11. On the other hand, if the timer value is NO, proceed to step D and voltage limit circuit 1
1 driver 20 gives a KON signal (logic 1). Next, proceed to step F, and from the read timer 1, the reference value T
. By subtracting the timer value C' corresponding to υ, the speed control can be performed by the same process as in the past, so the flowchart and explanation will be omitted.

(Effects of the Invention) As explained in detail above, the present invention enables printing without controlling printing density by changing the motor supply power according to the voltage when the power supply voltage becomes below a certain value. It becomes possible to adjust the speed, thereby reducing the maximum power consumption of the printer and reducing the power supply capacity, which has the advantage of making it easier to make the printer smaller and lighter.

Furthermore, there is an advantage that printing throughput can be improved by keeping the printing speed constant without stopping the motor within a certain voltage range of the power supply voltage.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of conventional printer control. FIG. 2 is a flowchart of the conventional processing of both parts. 3 and 4 are operation explanatory diagrams. FIG. 5 is a block diagram of a first embodiment of the present invention. FIG. 6 shows a voltage detection circuit according to the first embodiment of the present invention, and FIG. 7 is an explanatory diagram of the operation of FIG. 6. FIGS. 8(a) and 9(b) are explanatory diagrams of the operation of the first embodiment. FIG. 1O is a clock diagram of a second embodiment of the present invention. FIG. 11 shows a voltage limit circuit according to a second embodiment of the present invention, and FIG. 12 is an 11th operation explanatory diagram. FIG. 13 is an explanatory diagram of the operation of the second embodiment. FIG. 111 is a flowchart 1 of the processing of the control section in the second embodiment. 1...Control i11 section, 2...Head drive circuit, 3...
・H, C, 4...Motor drive circuit, 5...Motor,
6... A/D converter, 7... logic power supply, 8... 9 power supply, 9... voltage limit, 1 circuit, 10...
Addition point, 11...voltage limit circuit with 0N-QFF function example, 12... operational amplifier, 513... diode, 14-19... resistor, 20... driver, 21...
・・ON-OFF signal line, 22・D/A converter.

Claims (2)

[Claims] (1) A control circuit, a DC motor, a carriage unit driven using the power obtained from the DC motor, and a speed detection means for detecting the speed of the carriage unit or the DC motor, and the output of the speed detection means is In a method for fully controlling a spacing device of a printer in which a servo system is formed by feeding and packing a control circuit, a voltage detection circuit is connected to the power source of the DC motor, and the output of the voltage detection circuit is connected to the feed bar and the spacing device of the printer. A spacing speed control method for a printer, characterized in that the speed is also adjusted by a feed/pack system of the voltage detection circuit by inputting the voltage into a summing point of the system. (2) Set the voltage detection circuit function to 0N-OF to the voltage detection circuit.
2. A spacing speed control method for a printer according to claim 1, wherein a terminal is provided to enable speed adjustment by ON-OFF.