The reciprocating movement control mode of dot matrix printer
The present invention relates to the reciprocating movement control mode of dot matrix printer.
Fig. 3 represents the printing principle of dot matrix printer.
In Fig. 3, be provided with printing and hammer assembly 200 into shape by being with 270 to be arranged on 2 pulleys 260 synchronously with the word of word hammer, and when driving one of them pulley 260 by stepper motor 210, this word hammer assembly 200 stroke along continuous straight runs according to the rules moves back and forth.
Word hammer assembly 200 is provided with linear transducer 280, when word hammer assembly 200 moves, above-mentioned linear transducer 280 sends signal according to certain interval, not shown print control unit is according to this signal, drive above-mentioned printing and hammer into shape, and print with 220 assigned positions in printing paper 230 by China ink with word.
When the printing of 1 stroke that is carried out when word hammer assembly 200 finishes, by stepper motor 210 is rotated in opposite direction, the moving direction counter-rotating of word hammer assembly 200, during moving to next print position, by transmit the printing paper transmission haulage gear 250 that motor 240 drives by printing paper, with printing paper 230 amount of movement transmission according to the rules, begin to carry out the printing of next stroke.
Fig. 4 is the block diagram of the print control section in the dot matrix printer, and Fig. 5 is the sequential chart of the output signal of linear transducer 280.
In Fig. 4, CPU (central processing unit) 10 is according to the data according to the program of weaving in advance, and the signal of the excitation phase place of stepper motor 210 is exported to motor drive circuit 40, drives stepper motor 210.When driving stepper motor 210, word hammer assembly 200 moves, and as shown in Figure 5, linear transducer 280 sends two the signal psi A and the φ B of 90 ° of phase phasic differences.When word hammer assembly 200 is mobile from left to right, φ A90 ° transmission before the φ B ultrasonic, when word hammer assembly 200 is mobile from right to left, the leading φ B90 ° transmission of φ A.Waveform transformation circuit 30 output can be hammered the signal " DIR " that the moving direction of assembly 200 is judged into shape to word, this signal " DIR " before the φ B ultrasonic φ A90 ° be " 1 " when transmitting, when the leading φ B90 of φ A ° of transmission, be " 0 ".In addition, above-mentioned waveform transformation circuit 30 is the rising portion of the φ A when φ B is " 0 " also, output pulse signal " CLK ".If when " DIR " is " 1 ", location counter 20 inputs " CLK " are then carried out add operation to this calculated value, if when " DIR " is " 0 ", location counter 20 inputs " CLK " are then carried out subtraction to this calculated value.
CPU10 judges the position of word hammer assembly 200 according to the data from position calculator 20 inputs, in addition according to the time interval of the pulse signal of importing from waveform transformation circuit 30 " CLK ", calculates the speed of word hammer assembly 200.CPU10 calculates the driving time of printing with the word hammer according to these information, and word hammer driving signal is exported to word hammer drive circuit 50.This word hammer circuit 50 drives signal according to the word hammer that is sent by CPU10, drives to print and hammers into shape with word.
Stepper motor 210 is the motor that makes the rotor rotation in the mode of the excitation phase of switching stator winding in order, and the number of revolutions of this motor is determined that by the switching frequency of excitation phase place the anglec of rotation of motor is determined by the switching times of excitation phase.So, when generally motor being monitored, needn't control or definite its position its rotary speed by devices such as encoder or tachogenerators, open loop control can be carried out, thereby the designs simplification of equipment can be made, reduce cost.
But, when effect on the stepper motor 210 has the load of the torque that produces greater than motor, can produce " imbalance " phenomenon that rotor can not be followed the tracks of the switching frequency of excitation phase place.So, in open loop control, must switch the excitation phase place according to the frequency that is positioned at the safe range of not lacking of proper care.Otherwise, because the print speed of dot matrix printer is determined by the translational speed of word hammer assembly 200 that substantially people wish with the maximum speed that can limit word hammer assembly 200 to be moved like this.
So, in the reciprocating device in dot matrix printer, the imbalance of stepper motor 210 detects by linear transducer 280, and being provisional load variations such as following occasion or equipment fault, the imbalance of this stepper motor 210 causes, this occasion refers in the scope that does not have problems according to general service condition, make stepper motor 210 produce rotation, and word hammer assembly 200 is hung in the machine hole in the printing paper 230.
Fig. 6 represents an example of the imbalance detection method of stepper motor 210.
Fig. 6 represents the sequential chart of following occasion, and this occasion refers to that 4 phase stepper motors 210 turn round according to 2 phase excitation direction, and word hammer assembly 200 is with at the uniform velocity mobile.A phase, B phase, C phase, D represent the excitation phase place of the stator winding in the stepper motor 210 mutually, when signal is " 1 ", carry out excitatory to respective phase.In addition, when the speed reducing ratio of pulley 260 is 1, the phase place of stepper motor 210 is switched 1 time and its corresponding word hammer assembly 200 when moving, waveform transformation circuit 30 sends 1 subpulse signal " CLK ".
Owing to when stepper motor 210 normally rotates, word hammer assembly 200 is followed the tracks of the phase place switching frequency of stepper motors 210, and the number of times of phase place switching and the quantity of pulse signal " CLK " are consistent like this.But owing to the occasion that is in the imbalance state at stepper motor 210, word hammer assembly 200 can not be followed the tracks of the phase place switching frequency of stepper motor 210, and the quantity of pulse signal " CLK " is less than the number of times of phase place switching like this.When making the running of 4 phase stepper motors according to 2 phase excitation modes, if the difference of the quantity of number of times that phase place is switched and pulse signal " CLK " more than 4, then departs from 1 more than the cycle owing to excitation mutually, decidable stepper motor 210 is in the imbalance state like this.
In the manner described above, in the past owing to be in the occasion of imbalance state detecting stepper motor 210, can not whether be judging of causing of equipment fault to the reason of imbalance, or word hammer assembly 200 be hung in the machine hole in the printing paper 230 etc. occasion, can not judge provisional reason, thereby detecting when being in the imbalance state, interrupting printing.
But, if even stepper motor is under the situation of imbalance state, interrupt printing, still can produce the problem of the reliability reduction of equipment.Can thereby not make stepper motor be in the structure of imbalance state because of the former of non-equipment fault in order to form, then must be when generally motor being monitored by devices such as encoder or tachogenerators, be used for rotary speed is controlled or determined the closed-loop control of position, can produce the problem that equipment cost increases like this.
So the objective of the invention is is not increasing under the printer condition of cost, is carrying out making the control that moves back and forth of dot matrix printer that the reliability of printer improves.
According to an aspect of the present invention, a kind of reciprocating movement control mode of dot matrix printer, reciprocating device in this dot matrix printer moves back and forth word hammer assembly by following manner, this mode is: have printing and with the endless belt transmission parts of the word hammer assembly of word hammer 2 pulleys are connected by being provided with, drive in above-mentioned two pulleys one by stepper motor, it is characterized in that, be provided with:
Set the phase switching cycle setting device of phase switching cycle, above-mentioned phase switching cycle determines the rotary speed of above-mentioned stepper motor:
The imbalance checkout gear, according to the phase switching times of above-mentioned stepper motor with the imbalance that the pulse signal that is output detects above-mentioned stepper motor that moves back and forth of above-mentioned word hammer assembly,
When above-mentioned imbalance checkout gear detects the imbalance of above-mentioned stepper motor in print procedure, above-mentioned phase switching cycle setting device change phase switching cycle, the rotary speed of above-mentioned stepper motor is switched to the traceable speed of above-mentioned word hammer assembly, under this state, print action continuously.
According to another aspect of the present invention, a kind of reciprocating movement control mode of dot matrix printer, reciprocating device in this dot matrix printer moves back and forth word hammer assembly by following manner, this mode is: have printing and with the endless belt transmission parts of the word hammer assembly of word hammer 2 pulleys are connected by being provided with, drive in above-mentioned two pulleys one by stepper motor, it is characterized in that, be provided with:
Set the phase switching cycle setting device of phase switching cycle, above-mentioned phase switching cycle determines the rotary speed of above-mentioned stepper motor;
The imbalance checkout gear, according to the phase switching times of above-mentioned stepper motor with the imbalance that the pulse signal that is output detects above-mentioned stepper motor that moves back and forth of above-mentioned word hammer assembly,
When above-mentioned imbalance checkout gear detects the imbalance of above-mentioned stepper motor in print procedure, above-mentioned stepper motor is quit work after the vibration of above-mentioned word hammer assembly finishes, make above-mentioned word hammer assembly move to assigned position, then begin to print.
According to a further aspect of the invention, a kind of reciprocating movement control mode of dot matrix printer, reciprocating device in this dot matrix printer moves back and forth word hammer assembly by following manner, this mode is: have printing and with the endless belt transmission parts of the word hammer assembly of word hammer 2 pulleys are connected by being provided with, drive in above-mentioned two pulleys one by stepper motor, it is characterized in that, be provided with:
The imbalance checkout gear is according to the phase switching times of above-mentioned stepper motor with the imbalance that the pulse signal that is output detects above-mentioned stepper motor that moves back and forth of above-mentioned word hammer assembly;
Whether control device when above-mentioned imbalance checkout gear detects the imbalance of above-mentioned stepper motor, is judged proceeding to print still to stop to print,
The occasion that repeatedly is in the imbalance state at above-mentioned stepper motor continuously stops to print action, then proceeds to print action in other occasion.
Fig. 1 is the flow chart of one embodiment of the invention;
Fig. 2 represents the velocity wave form of the word hammer assembly of one embodiment of the invention;
Fig. 3 is the printing schematic diagram of dot matrix printer;
Fig. 4 is the block diagram of the print control section of dot matrix printer;
Fig. 5 is the sequential chart of the output waveform of linear transducer;
Fig. 6 is the schematic diagram of an embodiment detecting of the imbalance of stepper motor.
Fig. 1 and Fig. 2 represent embodiments of the invention.
Fig. 2 represents to be equivalent to the speed of the word hammer assembly 200 of 1 stroke, solid line is represented speed just often, dotted line is illustrated in the speed that stepper motor 210 in the print procedure is in the occasion of imbalance state, and dotted line is illustrated in the speed that stepper motor 210 when not printing is in the occasion of imbalance state.
In Fig. 2, CPU10 makes word hammer assembly 200 accelerate to speed Vh at acceleration region, at the uniform velocity regional above-mentioned word hammer assembly 200 is moved according to the constant speed of speed Vh, make above-mentioned word hammer assembly 200 decelerate to 0 speed in the deceleration zone, word hammer assembly 200 edge opposite directions are moved.CPU10 compares the phase place switching times of stepper motor 210 and the quantity of pulse signal " CLK " at imbalance surveyed area shown in Figure 2, in the occasion of its difference greater than predetermined value X, judges that then stepper motor 210 is in the imbalance state.
In addition, linear transducer 280 is used to detect the action of stepper motor 210, it can be subjected to synchronously with 270 the elongation or the loosening influence of mechanism, and after the moving direction counter-rotating of word hammer assembly 200, this word hammer assembly 200 is just at once inconsistent with the motion of stepper motor 210.Thus, in fact in the zone (imbalance surveyed area) that the motion of the motion of word hammer assembly 200 and stepper motor 210 is consistent substantially, judgement stepper motor 210 is in the imbalance state.
Flow chart when Fig. 1 represents stepper motor 210 drivings.
In Fig. 1, CPU10 is at the controlling organization that to detect occasion that stepper motor 210 is in driving condition and is in the imbalance state be continuously to printing or interrupt judging, according to the data that are written as program in advance, start the phase place switching and use timer, the phase place of stepper motor 210 is switched.When the phase place switching finishes with the timer timing, number of times according to the phase place switching, judge whether being in the imbalance surveyed area,, then calculate the difference of the quantity of phase place switching times and pulse signal " CLK " if at the imbalance surveyed area, if the absolute value of this difference is less than setting X, then be judged to be normally, then in the time must making stepper motor 210 produce rotation, in the phase place switching data of setting next time in the timer, start the phase place switching and use timer, the phase place of carrying out next time is switched.If the absolute value of the difference of the quantity of phase place switching times and pulse " CLK " is greater than setting X, judge that then stepper motor 210 is in the imbalance state, this moment is if be in following occasion, promptly not 2 times continuous imbalance and be in the print procedure, the phase place of then carrying out speed and be Vh ' (Vh>Vh ') is switched, and finishes until printing.In addition, Vh ' is even for detecting the still traceable speed of situation lower word hammer assembly of imbalance state.After this, stepper motor 210 is slowed down, stepper motor 210 quits work, and the vibration end until word hammer assembly 200 then begins to carry out the printing of next stroke.Not being at non-2 continuous imbalance states and being in occasion in the print procedure, stepper motor 210 is quit work, finish until the vibration of word hammer assembly 200, after this make word hammer assembly 200 move to assigned position, begin to print.In the occasion of carrying out 2 continuous imbalances, then be judged to be printer and break down, interrupt printing and showing mistake.
Form or the structure of printer of CPU10 by stepper motor 210 determines to judge that stepper motor 210 is in the setting X of imbalance state, the zone detected of lacking of proper care, detect phase place switch speed Vh ' behind the imbalance state, judge the imbalance number of times that printer breaks down.
Such as, in the reciprocating device in dot matrix printer shown in Figure 3, in the occasion of 4 phase stepper motors according to the running of 2 phase excitation modes, preferably afore mentioned rules value X is 4~8, the lack of proper care zone detected is the scope of the phase place of carrying out 2~3 times after stepper motor 210 direction of rotation change switching, speed Vh ' judges that less than 1/2 of the maximal rate of word hammer assembly 200 the imbalance number of times that printer breaks down is 2~3 times.
If realize the present invention in the manner described above, owing to can to the imbalance reason of stepper motor whether be cause temporarily or the printer fault causes judges, thereby can not increase under the printer condition of cost, improve the reliability of printer.