JPS6091900A - Controller for stepping motor - Google Patents

Abstract

PURPOSE:To reduce the power consumption of a stepping motor by switching the applying voltage to the motor on the basis of the predetermined switching condition. CONSTITUTION:One end of exciting coils A, B, -A, -B of a stepping motor is connected to drivers 161-164 for selecting the exciting phase, and the other end is connected directly to a low voltage power source 155 or to a high voltage power source 156 through power source switching drivers 170, 171. The exciting phase is selected by signals SPA, SPB from a slave microcomputer 132, and a power source is selected by signals HA, HB. A high voltage power source 156 is selected at the initial of exciting in every phase, and a large current is flowed to the exciting coil. When the prescribed time is elapsed, the drivers 170, 171 are turned OFF on the basis of the predetermined switching conditions, and switched to the low voltage power source 155.

Description

[Detailed description of the invention] Ko Seikodan The present invention relates to a stepping motor control device.

Emperor Kosue For example, thermal printers and electrical transfer printers.

2. Description of the Related Art Among various serial printers such as inkjet printers, type printers, and wire dot printers, there are some in which a carriage is driven by a stepping motor.

Conventionally, in printers with low-speed printing mode and high-speed printing mode, in order to enable high-speed printing, in order to enable high-speed printing, the stepping motor is used to provide the same amount of power in the low-speed printing mode as in the high-speed printing mode. is supplied to.

However, if the power necessary for the high-speed printing mode is constantly supplied in this manner regardless of the printing speed, there is a problem in that power consumption increases.

In addition, if a constant power is always supplied in this way, when printing continuously for a long time, the resistance of the windings increases as the temperature of the motor increases, the current decreases, and the torque becomes weaker. It is necessary to provide a margin for the power to be used, and there is a problem that a larger amount of power must be supplied, resulting in even greater power consumption.

- Neck This invention was made in view of the above points, and an object thereof is to reduce the power consumption of a stepping motor.

Encounter aummaru travel father-in-law Hereinafter, the configuration of the present invention will be explained based on one embodiment.

FIG. 1 is a functional block diagram showing an embodiment of the present invention.

This stepping motor control device includes a first excitation voltage applying means B that applies a first excitation voltage to the stepping motor A, and a second excitation voltage that applies a second excitation voltage higher than the first excitation voltage to the stepping motor A. excitation voltage application means C
It is equipped with

Then, the second excitation voltage applying means C is switched by the switching means.
The application time of the second excitation voltage during excitation for each excitation phase of the stepping motor A is switched according to predetermined switching conditions.

In this case, the switching means always supplies the first excitation voltage from the excitation voltage application means B of the box 1 to the stepping motor A, and supplies the second excitation voltage from the second excitation voltage application means C for a predetermined period of time. voltage to the stepping motor A, or by switching between the first excitation voltage from the first excitation voltage application means B and the second excitation voltage from the second excitation voltage application means C. supply

In this way, this stepping motor control device applies the high voltage (second excitation voltage) to the excitation phase of the stepping motor A by switching the application time according to the predetermined switching conditions.

Therefore, for example, if this stepping motor control device is used to drive and control the space motor that drives the carriage of a serial printer, the application time of the high voltage may be switched depending on the printing speed, such as in low-speed printing mode. In some cases, the high voltage application time can be shortened, and in high-speed printing, the high voltage application time can be increased.

This reduces power consumption compared to when a high voltage is constantly applied.

Similarly, the high voltage application time can be changed according to the continuous printing time, for example, the high voltage application time can be shortened until the continuous printing time reaches a predetermined time, and after the predetermined time has passed, the high voltage application time can be shortened. The time for applying high voltage can be increased.

Thereby, it is possible to correct the decrease in torque due to heat generation of the stepping motor, and power consumption is reduced.

Furthermore, the application time of the second excitation voltage can be switched depending on the printing speed and continuous printing time, and in this way, power consumption can be further reduced and the decrease in torque can be compensated for. .

FIG. 2 is an external perspective view showing an example of a thermal printer embodying the present invention.

The outer casing of this printer consists of a lower case 1 and an upper case 2 that house a mechanical section and a control section, and a cover 3 for a ribbon cassette section.

A control panel 4 provided on the front of the printer is equipped with various switches and indicators.

Online/offline (ONLloFL) switch 5
is a switch for switching between online and offline, and the state is set to offline when the power is turned on, and the state is switched between online and offline with each subsequent operation.

The form feed (FF) switch 6 is a switch that instructs form feed to feed the paper to the top position of the next page, and is valid only when offline.

The speed changeover (50/100) switch 7 is a switch for changing the printing speed between 50 CPS (low speed printing mode) and 100 CPS (high speed printing mode).

Pica/Elite (PIC/E LT) switch 8
is a switch that switches the printing pitch between 1/10' and 1/12'.

The ribbon end indicator 9 is an indicator consisting of a light emitting diode, an autograph, etc., which indicates the paper end and the ribbon end.

ON L/OF' L indicator 10 is 0NL10F
This is a display made of a light emitting diode or the like that displays online/offline selected by the L switch 5.

There is also a power switch 11 on the rear side of this printer.
Similarly, a density selection switch 12 is attached to the top surface.

FIG. 3 is a perspective view showing the mechanism of this printer.

On the rear top surface of the lower case 1 of this printer, there is a temporary
As shown in the phantom diagram, a paper storage section 15 is formed as a substantially semi-cylindrical recess for storing roll paper 16, and a mechanism section is housed in the front part of the lower case 1.

This mechanical part consists of the left and right side plates 2 that make up the frame.
A guide plate 22 for supplying cut paper into one mechanism section and a guide plate 23 for supplying the roll paper 16 stored in the paper storage section 15 are stacked at a predetermined interval at the rear of the 0.21 mechanism and placed in front. It should be installed with the side facing downward.

And in front of these guide plates 22, 23.

A platen 24 for winding and feeding cut paper guided and fed by a guide plate 22 or roll paper guided and fed by a kite plate 23 is mounted on one side Fi20.

It is rotatably attached to 21.

This platen 24 is rotationally driven via a gear train 2S by a line foot motor consisting of a Stella Pink motor (not shown) fixed to the side plate 21, and automatically feeds the paper.

Further, the platen 24 can be manually rotated by turning a knob 26 connected to a gear train 25. Note that a knob cover 26a having a knurled surface is fitted onto the knob 2C as shown in FIG.

Furthermore, in front of this platen 24, both side plates 20.2
Operation lever 2 of the paper setting mechanism 27 attached to the outer surface of 1
A rod 29 that can swing back and forth in conjunction with the rod 29 and a paper presser bar 32 consisting of rollers 30 and 31 that are rotatably inserted into the rod 29 are provided.

In front of this platen 24, this platen 24
Guide rods 64 fixed to both side plates 20 and 21 in parallel with
A carriage 40 is mounted on a rail portion 6, which is a part of the front plate 35, so as to be movable parallel to the platen 24.

The carriage 40 is equipped with a thermal head 41 and ribbon guide rollers 42 and 43 for guiding the thermal ribbon between the thermal head 41 and the platen 24, the details of which will be described later.

The carriage 40 is driven by a space motor 46 consisting of a Stella Pink motor attached to a motor frame 45 fixed to the bottom plate 44.

A pulley 48 attached to the right side plate 21 and the left side plate 20 are rotationally driven by this space motor 46 via a gear train 47.
It is moved via a timing belt 50 stretched between a pulley 49 attached to the timing belt 50.

On the other hand, a ribbon cassette 51 is placed at the top of this mechanism section.
It is attached and mounted on the side plates 20 and 21 thereof.

This ribbon cassette 51 has a heat-sensitive ribbon 53 housed within a cassette body 52.

The thermal ribbon 53 of this ribbon cassette 51 is
A ribbon foot motor 55 consisting of a Stella Pink motor attached to a motor frame 54 fixed to the bottom plate 44 rotates the ribbon through a gear train 56 and connects it to a winding drive roller in the ribbon cassette 51. is moved via a drive shaft 57.

Further, on the mechanism section side, a ribbon end sensor 59 is provided which is constituted by a photosensor including a light emitting element and a light receiving element for detecting the end of the ribbon 53 of the ribbon cassette 51.

4 and 5 are a plan view and a left side view showing details of the carriage of this mechanism section.

In this carriage 40, first, a head holder 64 with a thermal head 41 attached thereto is rotatable by a support shaft 65 on brackets h62 and 63 formed on the front surface of a carriage block 61 which is slidably inserted into a chi 1-rod 64. It is installed.

This head holder 64 has head pressing springs Ei6a and 6 at both ends thereof to prevent the thermal head 41 from being pulled out.
The head holders 66 and 67 formed with 7a are attached.

Further, a head (=J-force member 6) having a tongue-shaped plate spring 68 integrally formed thereon is attached to the lower part of the holder 64.

On the other hand, a tongue piece 7 for fixing the timing belt 50 to the carriage block 61 is provided at the lower part of the carriage block 61.
A solenoid holder 71 integrally formed with the head up/down solenoids 1 to 72 is attached to the solenoid holder 71.

Plunger 72 of this head up/down solenoid 72. The front end of the head biasing member 69 is fitted with the base of the leaf spring 68, and the traction member 73 is fixed to the tip thereof.

In the carriage 40 configured in this manner, the head up/down solenoid 72 is deactivated when loading paper or replacing the ribbon.

As a result, the head holder 64 is held in the state shown in the figure by the restoring force of the leaf spring 68, and the thermal head 41 is held in a position away from the platen 24 as shown by the solid line in FIG.

Then, during printing operation, from this state 8tsu1~up/
The down solenoid 72 is activated.

As a result, the plunger 72a moves in the direction of arrow A together with the base of the plate spring 68 in FIG.
rotates toward the platen 24 as shown by the imaginary line in the figure, and becomes ready for printing, so that the thermal head 41 is instantaneously heated and printing is performed.

Further, a rotating arm 75.7 is attached to the upper surface of the carriage block 61 of the carriage 40 by a screw 74.74.
El is shown by an arrow and is rotatably mounted in the E direction (Fig. 4).

Paper kites 77 and 78 are attached to the front ends of these rotating arms 75 and 76, and ribbon guide rollers 42 and 46 are rotatably supported by fixed shafts 80 and 81. Auxiliary rollers 84 and 85 are rotatably supported by fixed shafts 82 and 83.

Further, substantially hemispherical click stops 75a, 76a are formed on the lower surfaces of these rotating arms 75, 76, while substantially hemispherical four portions 61a, 76a are formed on the upper surface of the carriage block 61.
61b, these click stoppers 75a,
76a and recess 61a.

61b and the stopper 86 to rotate the arm 75°76.
Regulates the rotation range of.

FIG. 6 is a block diagram showing the control section of this printer.

The control unit 130 includes a CPU (central processing unit) and a block RAM memory (ROM) that performs overall control.

A mask microcomputer (hereinafter referred to as "microcomputer") 161 consisting of RAM (data memo 1) and ■10 (input/output device), etc., a slave microcomputer 162 that mainly controls motors and solenoids, and programmable peripherals. Interface (hereinafter referred to as r I 10J) 133, 134, character generator (CG
) ROM 135, three RAMs 136 to 138 forming a line buffer, and drive circuits 141 to 147.
It consists of

The mask microcomputer 131 of this control unit 130
Sends data to and from the host system via the Centronics interface 150 and l10133,
Input various data such as print data, carriage movement amount data, carriage return data, line feed data, etc. from the host system side.

In addition, this mask microcomputer 131 connects ON Llo F provided on the operation panel 4 in FIG. 2 via l10133.
L switch5. Various operating information and detection information from the FF switch, 507100 switch 7, PI(,'ELT switch 8, and paper end sensor 151, not shown in FIG. 3) are input.

Then, this master microcomputer 131 processes based on these, and transfers data necessary for controlling printing speed information, carriage movement, line feed, etc. to the slave microcomputer 132 according to the processing results.

The mask microcomputer 131 also converts print data from the host system into character pattern data using the ROM 135, and controls the thermal head 41 via the l10134 and drive circuit 147 according to this character pattern data. control to print the necessary characters.

Furthermore, this mask microcomputer 131 controls the lighting of the ribbon end indicator 9 via the drive circuit 145 when the ribbon end sensor 5 detects the ribbon end and when the paper end sensor 151 detects the paper end. Further, in accordance with the operation of the 0NL10FL switch 5, the lighting of the 0NL10FL display 10 is controlled via the drive circuit 146.

On the other hand, the slave microcomputer 162
Based on the data from 1 and the detection signal from the left margin sensor 152 (not shown in FIG. 6), the space motor 4 is activated via the drive circuit 141 for printing.
6 is driven and controlled by two-phase excitation to control the movement of the carriage 40 (FIG. 6). Note that details of this control will be described later.

Also, this slave microcomputer 132 performs a line break.

For form feed, etc., a line feed motor 1 (not shown in FIG. 3) is connected via a drive circuit 142.
53 to rotate the platen 24.

Furthermore, this slave microcomputer 132 operates on the redrive circuit 1 in order to wind up the ribbon 53 of the ribbon cassette 51.
The ribbon foot motor 55 is drive-controlled via the motor 46 to rotate the drive shaft 57.

Furthermore, this slave microcomputer 162 is operated via the drive circuit 144 for printing.
The down solenoid 72 (FIG. 5) is driven and controlled to move the thermal head 41 to a printable state and a retracted position.

Further, this slave microcomputer 132 transfers the detection signal of the ribbon end sensor 59 to the mask microcomputer 131.

Figure 7 shows the drive circuit 1 for the space motor in Figure 6.
41 is a block diagram showing details of 41. FIG.

First, each excitation coil A of the space motor 46.

B, A, and B are directly applied with the first excitation voltage VN from the low voltage power supply 155, which is the first excitation voltage application means, and the high voltage power supply 1, which is the second excitation voltage application means.
56 to a second excitation voltage V higher than the first excitation voltage VN.
W4 (VM>V, N) is applied via the drive circuit 141.

This drive circuit 141 first receives drive pulses SPA and 5PI from the slave microcomputer 132 by drivers 161 to 164 consisting of electrodynamic control transistors and the like.
3 and the drive pulse SP generated by inverting these drive pulses SPA and SPB with inverters 165 and 166.
A, each excitation coil A, B of the space motor 46 according to SPB.

Controls the excitation of A and B.

Further, this drive circuit 141 includes resistors 1 and 1 each inserted in the power supply path from the high voltage power supply 156 to the space motor 46.
67, 168 and transistors 16, high voltage power supply 1
The application of the second excitation voltage VM from 56 to the space motor 46 is controlled.

Note that in this embodiment, the slave microcomputer 132
and drivers 170, 171 and inverters 172, 17
3 constitutes a switching means.

Next, the operation of this embodiment configured as described above will be explained with reference to FIG. 8 and subsequent figures.

First, the operation of the master microcomputer 131 shown in FIG. 6 will be described with reference to FIGS. 8 to 13.

The mask microcomputer 161 is connected to the power switch 1 shown in FIG.
When 1 is input, the main routine shown in FIG. 8 is executed.

In other words, after making the predetermined initial settings in ST[EPl, 5TEP2 prints a predetermined test graphic character to determine whether the printer is performing a self-test to determine whether it is normal or not. If the determination result is self-diagnosis, proceed to 5TEP 7, which will be described later.

Also, if the discrimination result is not a self-diagnosis, S1'[', P
3, the status of the ON Llo F L switch 5 is checked to determine whether it is online or offline.

If this determination result is offline, F with 5TEP 4
Check the state of F switch 6 to determine whether it is form feed or not, and if it is form feed, 5TEP5
transfers the required data to the slave microcomputer 132 and controls the line foot motor 153 to drive the platen 24.
is rotated to move the operating position to the corresponding position of the first line of the next page, and if it is not a form foot, return to 5TEP 3.

On the other hand, if 1 discrimination result is online, 5 TEP
After completing the online initial settings in step 6, set the 50/100 switch 7 and PIC/ELT on the operation panel 4 in step 5 TEP 7.
The state of the switch 8 is checked, printing speed information and printing pitch information are read, and the printing speed information and printing pitch information are transferred to the slave microcomputer 132.

After that, it is determined in 5TEP8 whether it is a self-diagnosis or not, and if it is a self-diagnosis, it proceeds to 5TEPIO, which will be described later.If it is not a self-diagnosis, it is checked in 5TEP9 whether there is data in the FIFO (receiving data buffer). If there is data, start processing the command with 5TEP l O, then 5T
Return to EP8.

In addition, if there is no data in the FIFO, 5TEP11 detects the status of the ON Llo F L switch 5, etc. on the operation panel 4, 5TEP12 determines whether it is offline, and if it is offline, 5TEP13 initializes the offline setting. After that, return to 5TEP 5, and if it is not offline, return to 5TEP 9.

Next, the process of receiving data from the host system side of the master microphone 131 will be explained with reference to FIGS. 9 and 10.

First, when data from the host system is serially transferred, the processing shown in FIG. 9 is executed by an interrupt.

That is, when an interrupt occurs, first, the register is saved in 5TEP21, and then it is determined in 5TEP22 whether reception is complete, and if reception is not completed, that is, if the received data is normal data, the process proceeds to 5TEP27, which will be described later.

On the other hand, if reception is complete, STV! , P23 reads the received data, and 5TEP24 sends the data to F.
After storing in the IFO, check whether the FIFO is full in S1'EP 25, and if it is not full, return 5.
After enabling reception at TEP26, if the state is full, the register is restored at 5TEP27 and the process returns to the main routine.

Furthermore, when data from the host system side is transferred in parallel, the processing shown in FIG. 10 is executed by one interrupt.

In other words, when an interrupt occurs, first the reception is disabled in 5TEP31, the register is saved in 5TEP32, and then
Read the received data at 5TEP33 and F at 5TEP34.
Store in IFO.

Then, in 5TEP35, check whether FII"0 is full or not, and if it is not full, enable reception in ST[P36, and if it is full, leave it as is, 5TEP3
After restoring the registers in step 7, the process returns to the main routine.

Next, 5TEP in the main routine shown in FIG.
IO command processing will be explained with reference to FIG.

First, 5TEP41 determines whether the data read from the FIFO is character code data or not. If it is character code data, 5THP42 processes the character code and then returns to the main routine.

On the other hand, if the data is not character code data,
5TEP43 performs code compression processing, and 5TEP44
Convert it to an internal command with 5TOP45 and decode the internal command.

Then, in 5TEP46-53, motion is activated according to the result of decoding the internal command.

Position (POS I T I ON), initial (INITO), and auto sheet feeder (ASF), which are absolute coordinate positioning operations based on the left margin.
and various other processes (not shown) are executed.Next, the motion of the 5TEP 47 in this command processing will be explained with reference to FIG.

First, in 5TEP61, it is determined whether the space (S' P ) for moving the carriage 40 or the line feed (L F) for rotating the platen 24 is used.

If the result of this determination is a space, 5TEP6
2 determines whether the space direction is positive or negative.

If this determination result is in the positive direction, S'TEP63 determines whether the space amount is in characters (CHR) or bits (BIT).
Determine whether it is a unit, and if it is a character unit, 5TEP
If the data for moving the carriage 40 in the forward direction in units of characters in 64 is in units of bits, then 5TEP65
Then, data for moving the carriage 40 in the forward direction bit by bit is transferred to the slave microcomputer 152.

Also, if the determination result of 5TEP62 is in the negative direction.

5TEPs 66 to 68 perform the same processing as 5TIEPs 63 to 65, and send data to the slave microcomputer 1 to move the carriage 40 in the negative direction in units of characters or bits.
Transfer to 32.

On the other hand, if the determination result of 5TEP61 is line feed, 5TEP69 determines whether the line feed direction is a positive direction or a negative direction, and 5TE
In P70 and P71, the positive direction or negative direction is specified as the line feed direction.

Then, 5TEP72 determines whether the line feed amount is in characters or bits, and according to this determination, the line feet movement amount is set in 5TEP73;74, and 5TEP75 transfers one line data to slave microcontroller 1!12. Transfer to.

Next, character code processing of 5TEP42 in command processing will be explained with reference to FIG. 16.

First, set the font information in STI3I'81, and
l'l! After processing the invalid code in P82, 5TEP
83 sets the address of the character generator (ROM 135), S'rEP 84 performs typeface processing, 5TEP 85 performs body face processing, and the character pattern data corresponding to the character coat data is stored in the line buffer (RAM 136). ~168).

Incidentally, the typeface processing is a process of reading data of a portion of the typeface PC excluding the portion of the character spacing PS within the body face PB indicating the entire character pattern, as shown in FIG.

Further, body face processing is processing in which character spacing PS data is added to the typeface pc data read in the typeface processing and the data is transferred to the line buffer.

In this way, the typeface and character spacing are stored as separate data, and the two data are combined to form character pattern data.The typeface and character spacing data are stored as one character pattern data in the character generator. This is because the capacity of the ROM is smaller than that required in the case where the ROM is used.

Next, processing operations executed by the slave microcomputer 132 will be described with reference to FIG. 15 and subsequent figures.

First, the drive routine will be explained with reference to FIG. 15.

When the slave microcomputer 162 is powered on, ST[!
After making initial settings in P91, data from the master microcomputer 131 is input in 5TEP 92.

Then, in 5TEP93, it is determined whether the input data is data such as print data that requires an X drive to move the carriage 40 and a Y drive to rotate the platen 24 (line feed), that is, whether or not it is an XY drive. .

If this determination result is an XY drive, then 5TIEP
Enter the xy drive information in step 94, and enter the X drive step (XDS) number data indicating the maximum movement amount of the carriage in the +X direction in that row in step S1'EP95. Set in register.

Thereafter, after a drive process for printing is performed in 5TEP96, it is checked in S1'EP97 whether or not heating of the thermal head 41 has been completed.

If heating is completed, set the drive step number set in the CR drive register in ST[EP98 to the X drive register, and perform a carriage return in STEP99.

After that, the output end information is transferred to the master microcomputer 1 and 1 at 5TIEL) 100.

On the other hand, if the determination result of ST[EP93 is that it is not an XY drive, 5TEP 101 determines whether it is a Y drive such as paper feed, and if it is not a
Return to 2, if Y1 ~ Live, 5TEIP1
02 Yl-live information manually, S1'EP I
After doing Y drive with O3, 5TEP 100 mentioned above
Proceed to.

Next, data input processing of the 5TEP 92 in this drive routine will be explained with reference to FIG.

Input buffer flag I at 5TEPI 11
It is determined whether the BF is in a full state (TBF'=1).

If IBF=1, 5TEP 1 ], after taking the received data into register R7 at 2, 5TEP l ],
Set the data input flag in step 3 and 5TEP l
After processing to disable external interrupts in step 14, the process returns to the drive routine.

Next, S T E 1 in the same drive routine
) 96 will be explained with reference to FIG.

First, specify the child direction with 5TEP121, and
' After turning on the Macnet (head up/down solenoid) at 122, it is determined whether it is printing or CR at 5TEPI 23.

Then, in 5TEP 124 to 127, a timer pointer is set to determine the timing of excitation phase switching of the space motor 46 according to this determination result, and the space motor 46 is
The second excitation voltage VM from the high voltage power supply 156 in FIG.
The high power pointer that determines the timing to apply the 5 0 /
1. The setting is made according to the printing speed selected by the OO switch 7.

After that, start each timer with 5TEPI 28, and
At TIEP 129, it is determined whether or not it is CR. If it is not CR, it is determined at 5TEP 130 whether or not the drive has ended.

If the result of this determination is that the drive is not finished, execute 5TCP, 129 again, and if it is 1-live finished,
Proceed to 5TEP 133, which will be described later.

Also, if the discrimination result of 5TtEII 129 becomes CR, if the discrimination result of 5TEP 129 becomes CR, 5T
Execute line feed in EP131.132.

Then, after turning off the magnet at 5TIEP l 33, the process returns to the drive routine.

Next, regarding the drive process of the space motor 46, the first
This will be explained with reference to FIG.

First, when an internal interrupt occurs, the timer is stopped at STE'P 141, and the timing of this interrupt is determined at S1'EP 142 to switch the application state of the second excitation voltage VRII from the high voltage power supply 156. Then, it is not the timing to switch the excitation phase of the space motor 46.
In other words, it is determined whether or not it is the timing to switch only high power.

If the result of this determination is the high power only switching timing, it is checked in 5TEP 143 whether or not the high power start flag is set, and it is determined whether or not the high power is to be started.

If this determination result is high power start, 5TEP14
After setting the high power start flag in step 4, and if it is not the start of high power, high power switching processing is performed in step 5TEP 145, and then the high power switching flag is reset in step 5TUP 146.

Thereafter, at 5TEP 147, a timer value corresponding to the printing speed at that time is set, and after starting the timer at 5TEP 148, the process returns to the main routine.

On the other hand, if the determination result at 5TEEP 142 is not the switching timing for only high power, 5TEEP1
49 determines whether it is CR or printing, and if it is CR, it is 5TEP.
Perform a ribbon drive at 150.

Then, do an X drive with S1'EP 15] and 5
After switching to high power with TtiP152, 5TE
Decrement the number of X drive steps by 1-(
-1) and determines whether it is a through-up or not in 5TEP l 54.

If this discrimination result is through-up, 5TEP15
Increment the timer pointer (+1) at 5, and
Check whether the through-up is completed at TEP 156, and if the through-up is completed, it is 5T! EP 157 and 1
- Determine whether or not it is printed using ST [EP 158, and if it is, use the thermal spatula 1-41 to
Start heating.

Then, a timer value is set in 5TIEP 160, and after starting the timer in 5STEP 161, the process returns to the main routine.

On the other hand, if the determination result of 5TEP 154 is not through-up, ST[! At P 162, check the top flag to determine whether or not the speed is 1-tsubu, and if it is the top speed, check at 5TEP 163 whether or not the number of X drive steps (XDS) is the preset "XX". If it is rXXJ, set the down flag in S1'EP164, and if it is not rXXJ, proceed directly to the above-mentioned 5TEP]60.

In addition, the discrimination results of 5TEP 162 are
If not, determine whether the number of X drive steps is rOJ at 5TEP l 65, and if it is not rOJ, then
1'EP166 decrements the timer pointer (-1
), proceed to the aforementioned 5TEP 160, and if it is "0", after waiting for a predetermined time at S1'EP 167,
Set the drive end flag to Sera 1 with S'l”IEP168.
do.

First, the excitation phase switching and high power switching timing processing of the space motor 46 when such processing is performed will be briefly explained with reference to FIG. 1S. In addition, this 19th
The figure shows only one phase.

First, if the drive of the space motor 46 is set to star 1 at timing 'fS in FIG. Set the high power start flag to Sera 1.

Thereafter, at timing TA when a predetermined period of time has elapsed from this timing TS, since it is the timing for switching only high power, the process proceeds to 5TEPI 43 to determine whether or not to start power. is in the set state, so 5TEP l 45
Proceed to 1) to reset the high power start flag and switch to high power.

That is, at this timing TA, the output from the (a) Innotower continues.

Thereafter, the timing TBI, which is a predetermined period of time after the timing TA, is the timing for switching the excitation phase and outputting the power, so 5TEL+14
The processing from 9 onwards is performed to switch the excitation phase and output high power.

Then, since timing TC, which is a predetermined period of time after timing TB, is a timing for switching only high power, the process proceeds to 5TEP 143.

When it is 1:, the high power start flag is set to 11, so switching of the high power, that is, the application of the ino(war) is stopped.

Thereafter, excitation phase switching and high power output processing are performed at timing Ttsn, and high power output stopping processing is performed at timing TCn.

Next, the drive control of such space motor 46 is performed by the seventh
A detailed explanation will be given with reference to FIGS. 20 and 21 as well.

First, when driving and controlling the space motor 46 with two-phase excitation, the excitation coils A, B, A,
Excite B.

Table 1 Therefore, the slave microcomputer 132 has a printing speed of 50
At the time of CPS, drive pulses SPA and SPB having a pulse period of T1m5ec are outputted to the drive circuit 141, for example, as shown in FIGS. 1S (a) and (b).

Also, when printing speed or LOOCPS, 1, for example, 2nd
As shown in Figure 0 (a) and (b), one pulse period is T
2 m5ec drive pulse SPA.

Output SPB to the drive circuit.

Therefore, 1-live circuit 141's dry no.<161
~164 includes Figure 19 (Ino~(d)) or Figure 20 (
Drive pulses spΔ, 5PI3. shown in a) to (d).
SPA and S lower j are each manually operated.

Therefore, when the printing speed is 50 CPS (low speed printing mode), for example, at point 1 in FIG. This is the timing to switch the excitation phase of the space motor 46 from the excitation coil A to the excitation coil A, and it is also the high power switching timing, so for example, the drive pulse SPA is set to 'H'.
At the same time, the high power drive nozzle HA is set to H'' to turn on the driver 170.

As a result, the second excitation voltage VM from the high voltage power supply 156 is applied to the common terminal of the excitation coil A of the space motor 46, so that the common terminal voltage CA is changed, for example, as shown in FIG. becomes the second excitation voltage VFjI.

Then, a predetermined time ΔT1m from this time t1
After 5 ec has elapsed, since this time t2 is the timing for switching only high power, the high power drive pulse HA is set to L'' and the driver 170 is turned off.

Thereby, the high voltage power supply 156 is connected to the space motor 46.
Since the common terminal to the excitation coil A of the space motor 46 is disconnected from the first one from the low voltage power supply 155,
The excitation voltage VN is applied, and the common terminal voltage CA is the first
becomes the excitation voltage VN.

After that, at time t3, this time t3 is the timing to switch the excitation phase of the space motor 46 from the excitation coil path to the excitation coil B, and is also the high power disconnection timing, so for example, the drive pulse SPB is changed to I]''
to excite the excitation coil B, and set the high power drive pulse HB to -[I'' to the driver 17.
1 is turned on.

As a result, the second excitation voltage VM from the high voltage power supply 156 is applied to the common terminals of the excitation coils B and B of the space motor 46, so that the common terminal voltage cm is 1, for example, as shown in FIG. becomes the second excitation voltage VM.

Then, from this time point t3, a predetermined time ΔT1m
After 5 ec has elapsed, since this time t4 is the timing for switching only high power, the high power drive pulse HB is set to L'' and the driver 171 is turned off.

Thereby, the high voltage power supply 156 is connected to the space motor 46.
Since the common terminal of the excitation coils B and B of the space motor 46 is disconnected from the first
The excitation voltage VN is applied, and the common terminal voltage CB is the first
becomes the excitation voltage VN.

In this way, when the printing speed is 50 CPS, the time TI during which each exciting coil is excited.

To time! During the period, the second excitation voltage VM is applied, and during the remaining time (TL-ΔTt), the first excitation voltage VN is applied.

At this time, Δ'1゛l is ΔT 1<('L
'+-ΔT1), so that the low voltage application time is longer than the high voltage application time during low-speed printing.

On the other hand, when the printing speed is 100 cPs (high-speed printing mode), the pulse width of the drive pulses SPA, SPB, SPA, and Sl-'H becomes T2 m5ec (TI > T2), as shown in Fig. 21. , 1-11 addition time Δ of the high voltage (second excitation voltage VRA) at this time
T2 is set to the relationship ΔT2>(T2−Δ′1′2) so that the low voltage application time is shorter than the high voltage application time.

In addition, when controlling the space motor 46 of this printer with two-phase excitation, one pulse period of the drive pulse is 3.3 m5 ec when the printing speed is 50 CPS, and for example, if the high voltage application time is set to 1°2n1 sec. , the low voltage application time is set to 2,'1 m5ec.

Further, when the printing speed is 100 cI)S, one pulse period is 1.66 m5 ec, and for example, the high voltage application time is set to 1,000 sec, and the low voltage application time is set to 0°66 m5 ec.

In this way, in this printer, a high voltage (second excitation voltage) is applied for a predetermined period of time during excitation of each phase of the space motor that drives the carriage, and the application jJ11
The time is changed according to the printing speed.

As a result, the low voltage printing time can be extended during the low speed printing mode, and the high voltage application time can be extended during the high speed printing mode 1.

Therefore, compared to the case where a high voltage is constantly applied, power consumption is reduced because a high voltage is applied for a predetermined period of time, and the power consumption is further reduced because the high voltage application time is changed according to the printing speed.

Note that in the above embodiment, the application time of the second excitation voltage (high voltage) is changed depending on the printing speed.
For example, the high voltage application time may be kept constant regardless of the printing speed, and may be switched depending on whether the continuous printing time exceeds a predetermined set time.

In other words, if the continuous printing time exceeds a certain time, the torque will decrease due to the heat generated by the motor, so in that case, it is possible to suppress the decrease in torque by increasing the high voltage application time to 120 to 130% of the normal time. can.

In this case, the continuous printing time can be measured, for example, by the continuous rotation time of a space motor, by the number of continuously printed lines, or by the number of continuously printed pages.

Moreover, by switching the application time of the second excitation voltage according to the printing speed and also according to the continuous printing time, it is possible to suppress a decrease in torque and to reduce power consumption.

Further, in the above embodiment, an example was described in which the space motor that drives the carriage of a thermal printer is controlled by the stellar and ping motor control device according to the present invention, but the present invention is not limited to this.

For example, carriage drive motors for various printers such as inkjet printers and type printers.

(Even if it is a type selection motor of a type printer or a stepping motor of other equipment other than a printer).

Effects As explained above, according to the present invention, the power consumption of the stepping motor can be reduced.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing an embodiment of the present invention. FIG. 2 is an external perspective view showing an example of a thermal printer equipped with a stepping motor control device embodying the present invention, FIG. 3 is a perspective view showing the mechanism, and FIGS. 4 and 5 are: Similarly, FIG. 6 is a block diagram showing the control section thereof, FIG. 7 is a block diagram showing details of the driver circuit 141 in FIG. 6, and FIG. 8 is a block diagram showing the details of the carriage. , FIG. 6 is a flowchart showing a main routine of processing executed by the master microcomputer. FIGS. S and 10 are flowcharts showing different examples of the reception processing routine. 11 is a flowchart showing the command processing routine of FIG. 8; FIG. 12 is a flowchart showing the MOTION processing routine of FIG. 11. FIG. 13 is a flowchart showing the character coat processing routine, FIG. 14 is an explanatory diagram for explaining the typeface processing and body face processing in FIG. 16, and FIG. 15 is a flowchart showing the character coat processing routine.
16 is a flowchart showing the data input processing routine of FIG. 15, and FIG. 17 is a flowchart showing the print processing routine, which is executed by the slave microcomputer shown in the figure. Flowchart, FIG. 18 is a flowchart showing the space motor drive routine, FIG. 19 is a timing chart 1-chart for explaining FIG. 18, and FIGS. 20 and 21 are low-speed printing Timing chart 1 of each part in Figure 7 during remote mode and high-speed printing mode
-Illustration. 5...Online/offline switch 6...Form feet switch 7...Printing speed changeover switch 8, Pica/Elli-1 switch 24...Platen 40...Carriage 41...Thermal head 46... -Space motor 1ro1...Master microcomputer 132...Slave microcomputer 141...Drive circuit 155...Low voltage power supply 156...High voltage power supply 161
~164...For excitation) Lime 170i71...High power driver Applicant Rico Co., Ltd. - Figure 13 Figure 14 Ij Figure 16 Figure 17

Claims (1)

[Scope of Claims] 1. A first excitation voltage applying means for applying a first excitation voltage to the stepping motor, and a second excitation voltage applying means for applying a second excitation voltage higher than the first excitation voltage to the stepping motor. excitation voltage applying means; and a second excitation voltage applying means by the second excitation voltage applying means when exciting each phase of the stepping motor.
and a switching means for switching the application time of the excitation voltage based on predetermined switching conditions. 2. The stepping motor control device according to claim 1, wherein the stepping motor drives a carriage of a serial printer, and the switching condition of the switching means is printing speed. 3. The stepping motor control device according to claim 1 or 2, wherein the stepping motor drives one carriage of a serial printer, and the switching condition of the switching means is continuous printing time.