JP4412314B2 - Motor control device, recording device - Google Patents

Description

The present invention controls the motor to drive the driving target to a predetermined target speed corresponding to the moving position of the driving target and performs deceleration control, thereby setting the driving target to a predetermined target stop position. The present invention relates to a motor control device that is stopped. The present invention also relates to a recording apparatus that performs recording on a recording material, including the motor control apparatus.

Hereinafter, an ink jet printer (hereinafter referred to as “printer”) as one of the recording apparatuses will be described as an example. The printer includes a recording head that ejects ink onto printing paper in a carriage that is reciprocally movable in the main scanning direction. A conveyance roller that conveys the printing paper is provided on the upstream side of the recording head, and the conveyance roller conveys the printing paper below the recording head at a constant pitch.

In such a printer, the carriage and the conveyance roller are driven by a motor (see, for example, Patent Documents 1 and 2). A motor control device that controls a motor obtains a deviation between a target speed value and an actual speed by a subtractor, and performs PID control based on the deviation. In the PID control, for example, based on a predetermined target speed table, the motor drive current is manipulated so as to decelerate the motor along a deceleration curve drawn by the target speed table. In such PID control, optimum control is performed by adjusting the coefficients (gains) of the proportional term (P), the integral term (I), and the differential term (D).
JP 09-058081 A Japanese Patent Laid-Open No. 60-071283

However, in the printer, for example, when the carriage is shifted from constant speed travel to decelerating travel and stopped at the target stop position by controlling the deceleration section by PID control, the carriage load is changed due to the dynamic load variation of the carriage. The stop position may be shifted back and forth from the target stop position. If the carriage stop position deviates before and after the target stop position in this way, for example, the next time the carriage performs main scanning, it becomes impossible to secure an acceleration section for entering the constant speed section, which affects print quality. In addition, a preliminary operation for securing such an acceleration section is required, which causes a problem that the throughput is lowered.

That is, the dynamic load of the carriage changes with time due to temperature change, secular change, sliding portion wear, grease consumption, and the like, and there are individual differences depending on component accuracy, assembly accuracy, and the like. Therefore, due to such factors, the stop position of the carriage deviates back and forth from the target stop position, which causes the above-described problems. In particular, in recent years, printers are strongly demanded to improve throughput, and it is necessary to set a strict deceleration curve, which makes it more difficult to stop at a target stop position. Such a problem occurs not only in the carriage but also in the conveyance roller that conveys the printing paper.

On the other hand, in order to solve such a problem, it is conceivable to use means for shifting the target stop position itself back and forth. However, in this case, for example, in a transport roller that transports printing paper, the paper feed amount must be changed to an optimum value each time, and thereby, printing that performs various processes using the cumulative value of the paper feed amount. It is difficult to achieve consistency in a control program (for example, a printer driver), and the processing becomes complicated. On the other hand, in order to perform more appropriate control in the PID control, it is also conceivable to use an auto-tuning unit that learns the control result and automatically adjusts to the optimum gain from the result. However, in this case, the burden on the CPU is large and the system tends to be complicated. When the gain is increased, there is a problem that the oscillation is large and the control amount becomes unstable.

Therefore, the present invention has been made in view of such a situation, and the problem is to accurately stop the drive target at the target stop position without being affected by load fluctuations and without changing the stop position. It is to obtain a motor control means capable of

  In order to solve the above-described problem, the motor control device according to the first aspect of the present invention controls a motor that drives a drive target to a predetermined target speed corresponding to the movement position of the drive target. A motor control device for stopping the drive target at a predetermined target stop position by performing deceleration control, wherein an actual stop position when the control for stopping the drive target at the target stop position is performed Stop position information storing means for storing as stop position information, and speed setting means for setting the target speed based on the stop position information, and the speed setting means corresponding to the movement position of the drive target. By changing the target speed, the stop position of the drive target is changed without changing the target stop position.

  According to this aspect, the drive target can be accurately stopped at the target stop position without being affected by the load fluctuation and without changing the stop position. That is, as a result of the deceleration control of the drive target, the motor control device stores stop position information storage means for storing the position where the drive target stops as stop position information, and a speed for setting the target speed based on the stop position information. Setting means. And based on the said stop position information, the said target speed corresponding to the movement position of the said drive target is changed. When the target speed corresponding to the movement position of the drive target is changed, the stop position of the drive target is thereby changed. Therefore, the drive target can be accurately stopped at the target stop position as described above. Since there is no need to change the target stop position, it does not affect the upper control means.

  A motor control device according to a second aspect of the present invention includes, in the first aspect, a target speed table in which the speed of the motor is set, and each of the positions from the position where the deceleration control is started to the target stop position. A deceleration curve drawn by the target speed corresponding to the position is determined by the target speed table, and the table length of the target speed table corresponds to the distance from the position where the deceleration control is started to the target stop position. The driving target is stopped at a position before the stop position stored in the stop position information storage means by shifting the reference range of the target speed table, or The deceleration curve changes so as to stop at a position earlier than the stop position stored in the stop position information storage means, and the speed setting It means, based on the stop position information, wherein the driven object is characterized in that shifting the reference range of the target speed table as to stop at the target stop position.

According to this aspect, the target speed can be changed very easily. That is, the target speed is set in advance by a target speed table. The target speed table is one in which the speed of the motor is set corresponding to the movement position of the drive target. For example, the positions P ₀ , P ₁ , P ₂ ,... P _m . _n (position P ₀ is a deceleration start position, position P _n is a target stop position), and speeds V ₀ , V ₁ , V ₂ ,... V _m ..., V _n (V ₀ > V _m > V _n ) is set.

Here, the speed V _m is one having a table length corresponding to the distance from the deceleration start position P ₀ to the target stop position _{P n (V 0 ~V n)} , in the present invention extend the length and, for _{example, V 0, V 1, V} 2, ··· V m ···, and V _{n + k.} The speed setting means shifts the reference range of the extended target speed table based on the stop position information. For example, when the initial reference range is V _{0 to} V _n and the stop position of the driving target exceeds the target stop position, the reference range of the target speed table is associated with the over amount. For example, V _{3 to} V _{n + 3} are shifted by a preset shift amount. Then, each of the target speed corresponding to the target stop position P _n is changed from deceleration start position P ₀ accordingly. Therefore, as described above, the stop position of the driving target can be easily changed without changing the target stop position.

The motor control device according to a third aspect of the present invention is the motor control device according to the first aspect, wherein the speed setting means determines the target speed corresponding to the movement position of the drive target based on a predetermined calculation formula. When the stop position deviates from the target stop position, the target speed is changed by substituting the stop position information into the calculation formula.
According to this aspect, the speed setting means substitutes a predetermined parameter corresponding to the amount of deviation between the stop position of the drive target and the target stop position into a predetermined calculation formula, Since the target speed is changed, the stop position of the drive target can be easily changed, as in the invention according to the second aspect described above.

A motor control device according to a fourth aspect of the present invention is the motor control device according to the first aspect, wherein the speed setting means has a plurality of target speed tables, and the stop position deviates from the target stop position. The target speed is changed by selecting the target speed table corresponding to the stop position.
According to this aspect, the speed setting unit has a plurality of the target speed tables, and selects the target speed table corresponding to the stop position when the stop position deviates from the target stop position. Thus, since the target speed is changed, the stop position of the drive target can be easily changed as in the invention according to the second aspect described above.

The motor control device according to a fifth aspect of the present invention is the motor control device according to any one of the first to fourth aspects, wherein the speed setting means sets a threshold value for a deviation amount between the stop position of the drive target and the target stop position. And the target speed is not changed when the deviation amount exceeds the threshold value.
According to this aspect, the speed setting means has a threshold value for a deviation amount between the stop position of the drive target and the target stop position, and when the deviation amount exceeds the threshold value, the target speed is set. For example, even when an abnormality occurs such as when the user forcibly stops the drive target during the movement operation of the drive target, the target speed is not changed. It is possible to accurately stop at the target stop position.

A recording apparatus according to a sixth aspect of the present invention has a recording head for recording on a recording material, a carriage provided to reciprocate in the main scanning direction, and a recording target at a position facing the recording head. A recording apparatus having a conveyance roller for conveying a material and a paper discharge roller for discharging a recording material recorded by the recording head, wherein the motor driving the carriage and the conveyance roller are driven. At least one of the motors is configured to be controlled by the motor control device according to any one of the first to fifth aspects.
According to this aspect, the motor that drives the carriage or the conveyance roller in the recording apparatus is controlled by the motor control device according to any one of the first to fifth aspects. The same effects as any of the embodiments can be obtained.

A recording apparatus according to a seventh aspect of the present invention is characterized in that, in the sixth aspect, the stop position information is updated every time a recording operation is completed.
According to this aspect, since the recording apparatus updates the stop position information every time the recording operation is completed, the latest stop position information is always obtained thereby, so that the drive target is always accurately set to the target stop position. Can be stopped.

According to an eighth aspect of the present invention, in the sixth or seventh aspect, the recording apparatus includes a measurement mode in which the driving target is driven to update the stop position information by detecting a predetermined condition. It is characterized by.
For example, when the stop position information is updated every time a recording operation is completed, if a considerable time has elapsed from the previous recording operation to the current recording operation, the driving load of the drive target There is a possibility that the driving object cannot be accurately stopped at the target stop position. However, in the invention according to this aspect, the recording apparatus includes a measurement mode in which the driving object is driven to update the stop position information by detecting a predetermined condition. By executing the measurement mode, the drive target can be accurately stopped at the target stop position regardless of fluctuations in the drive load.

A recording apparatus according to a ninth aspect of the present invention is characterized in that, in the eighth aspect, the measurement mode is executed when the recording apparatus is powered on.
According to this aspect, since the recording apparatus executes the measurement mode when the recording apparatus is powered on, it is possible to obtain the same effects as the invention according to the eighth aspect described above. .

A recording apparatus according to a tenth aspect of the present invention is characterized in that, in the eighth aspect, the measurement mode is executed when recording data is received and before the recording operation is started.
According to this aspect, since the recording apparatus executes the measurement mode at the time of recording data reception and before the start of the recording operation, the latest stop position information is reflected in the recording operation to be executed later. The drive target can be more reliably stopped at the target stop position.

A recording apparatus according to an eleventh aspect of the present invention is characterized in that, in the eighth aspect, the measurement mode is executed when the replacement of the ink cartridge mounted on the carriage is detected.
According to this aspect, the recording apparatus executes the measurement mode at the time of detecting the replacement of the ink cartridge. Therefore, the recording apparatus executes the measurement mode after the ink cartridge replacement operation in which the carriage driving load is likely to fluctuate. In the recording operation to be performed, the latest stop position information is reflected, so that the drive target can be more reliably stopped at the target stop position.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of an ink jet printer as a “recording apparatus” according to the present invention. The ink jet printer (hereinafter simply referred to as “printer”) 60 is provided with a paper feed insertion slot 61, and a printing paper 50 as a “recording material” is set in the paper feed insertion slot 61. The The set printing paper 50 is fed to a paper feed roller 65 by a paper feed roller 64 that is rotationally driven by a paper feed motor 63. The paper feed roller 65 is rotationally driven by a paper feed motor (hereinafter referred to as “PF motor”) 1 to convey and feed the fed print paper 50 between the driven roller 66 and feed it in the sub-scanning direction. . The carriage 3 performs recording (printing) on the printing paper conveyed by the PF roller 65 while reciprocating in the width direction (main scanning direction) of the printing paper, guided by the guide shaft 32.

The printed printing paper is conveyed toward the paper discharge roller 68. The paper discharge roller 68 is rotationally driven by the PF motor 1 via the tooth wheel trains 67 a, 67 b and 67 c, conveys the conveyed printing paper 50 to and from the driven roller 69, and sends it to the discharge port 62. Finally, the printed printing paper 50 is discharged from the discharge port 62 to the outside of the printer 60.

FIG. 2 is a perspective view showing in detail a portion of the carriage 3 shown in FIG. 1 and a carriage driving device that drives the carriage 3. An ink cartridge 34 is mounted on the carriage 3, and a recording head 9 is attached to a portion facing the printing paper 50. A nozzle row composed of a plurality of nozzles (not shown) is formed on the surface of the recording head 9 that faces the print paper 50, and ink in the ink cartridge 34 is ejected from the nozzle row toward the print paper 50. Printing (recording) is performed.

A carriage motor (hereinafter referred to as “CR motor”) 4 that is a drive source of the carriage 3 is configured by a DC motor in the present embodiment. A driving pulley (motor and pinion) 30 is attached to the motor output shaft of the CR motor 4, and a timing belt 31 is wound between the driving pulley 30 and the driven pulley 33. By this timing belt 31, the driving force of the CR motor 4 is transmitted to the carriage 3, and the carriage 3 reciprocates in the main scanning direction. The position and moving speed of the carriage 3 are detected by a linear encoder 11 (see FIG. 3 described later) including a code plate 12 having slits formed at predetermined intervals.

In the non-printing area of the carriage 3, a capping device 35 for sealing the nozzles of the recording head 9 during non-printing and a pump unit 36 for sucking ink from the nozzles are provided.

FIG. 3 is a block diagram illustrating a configuration of the control device 100 of the printer 60. The control device 100 includes a CPU 16, a DC unit (hereinafter referred to as “DCU”) 6 as a “motor control device”, a timer IC 17, an interface unit (hereinafter referred to as “IF”) 19, an ASIC 20, a PROM 21, a RAM 22, an EEPROM 23, A paper feed motor driver 2, a head driver 10, a CR motor driver 5, and a pump motor driver 8 are provided.

The DCU 6 of the control device 100 includes a detection signal from the paper detection sensor 15 that detects the start and end of the conveyed printing paper 50 and an encoder 13 that detects the actual position (current position) of the conveyed printing paper 50. And a detection signal from. Further, the DCU 6 is supplied with an output signal (for example, a rising signal for detecting the front end of the slit of the code plate 12 and a falling signal for detecting the rear end) from the linear encoder 11.

The CPU 16 controls the entire printer 60, and the timer IC 17 generates a periodic interrupt signal for the CPU 16. The IF 19 transmits / receives data to / from the host computer 18, and the ASIC 20 controls the print resolution, the drive waveform of the recording head 9, etc. based on the print data sent from the host computer 18 via the IF 19. To do.

The RAM 22 is used as a work area or program storage area for the ASIC 20 and the CPU 16. In the PROM 21 and the EEPROM 23, programs for the ASIC 20, the CPU 16, and the DCU 6 and data necessary for processing are stored.

The paper feed motor driver 2 controls the drive of the PF motor 1 under the control of the DCU 6 to feed paper. The pump motor driver 8 controls the pump motor 7 under the control of the CPU 16. The head driver 10 drives and controls the recording head 9 under the control of the DCU 6 so that ink is ejected from the recording head 9 based on the print data given from the IF 19. The CR motor driver 5 drives and controls the CR motor 4 under the control of the DCU 6 to move or stop the carriage 3.

Since the present invention relates to the control of the CR motor 4 among them, the control part of the CR motor 4 will be described in detail below. FIG. 4 is a block diagram showing a portion that performs drive control of the CR motor 4 in the DCU 6.

The DCU 6 includes a position calculator 6a, a subtractor 6b, a target speed calculator 6c as a “speed setting means”, a speed calculator 6d, a subtractor 6e, a proportional element 6f, an integral element 6g, a differential element 6h, an adder 6i, A D / A converter 6j, a timer 6k, an acceleration control unit 6m, and an internal memory (not shown) as “stop position information storage means” are provided.

The timer 6k and the acceleration controller 6m perform acceleration control in the acceleration section, while the position calculator 6a, the subtractor 6b, the target speed calculator 6c, the speed calculator 6d, the subtractor 6e, the proportional element 6f, the integral element 6g, The differentiation element 6h and the adder 6i perform PID control in the constant speed section and the deceleration section. The output of the acceleration controller 6m or the adder 6i, that is, the value (digital value) of the driving current of the CR motor 4 is sent to the D / A converter 6j and converted into an analog value. This analog value is given to the CR motor driver 5, and the CR motor driver 5 supplies the CR motor 4 with a current having the given analog value. As a result, the CR motor 4 rotates.

In the DCU 6, the position calculator 6 a calculates the current position of the carriage 3 that travels by the CR motor 4 based on the output signal from the linear encoder 11. The subtractor 6b calculates a position deviation between the target stop position and the current position calculated by the position calculation unit 6a. Here, the “target stop position” refers to the stop position of the carriage 3 in the current main scanning, and is given from the CPU 16.

The target speed calculator 6c calculates the target speed of the CR motor 4 based on the position deviation that is the output of the subtractor 6b. This calculation is executed each time an output signal is given from the linear encoder 11, for example.

The speed calculation unit 6 d calculates the actual speed of the CR motor 4 based on the output signal of the linear encoder 11. The subtractor 6e calculates a speed deviation between the target speed and the actual speed of the CR motor 4 calculated by the speed calculation unit 6d. The proportional element 6f multiplies the speed deviation by a constant Gp and outputs the multiplication result. The integrating element 6g integrates the speed deviation multiplied by a constant Gi. The differentiation element 6h multiplies the difference between the current speed deviation and the previous speed deviation by a constant Gd, and outputs the multiplication result. The outputs of the proportional element 6f, the integral element 6g, and the derivative element 6h are added by an adder 6i. Then, as described above, the addition result, that is, the driving current of the CR motor 4 is sent to the D / A converter 6j and converted into an analog current. Based on this analog current, the CR motor driver 5 Drive control.

FIG. 5A is a graph showing the relationship between the target speed V in the deceleration zone of the carriage 3 and the absolute position X of the carriage 3, and FIG. 5B is a partially enlarged view of FIG. is there. Here, the “absolute position” of the carriage 3 refers to the position (movement position) of the carriage 3 with reference to the standby position (home position: not shown) of the carriage 3.

As shown in FIG. 5 (A), the carriage 3 is shifted from the constant-speed running by the constant velocity V _a (traveling from left to right in FIG. 5) to the deceleration at the deceleration start position P _d, ultimately targets The operation of stopping at the stop position P ₀ is taken.

Here, the deceleration curve T ₀ from the deceleration start position P _d to the target stop position P ₀ is determined according to a target speed table stored in advance in the PROM 21, EEPROM 23, or internal memory (not shown) in the DCU 6.

Figure 6 shows a target speed table indicating the gear curve T _0. The target speed table stores a target speed having a smaller absolute value as the table column moves from top to bottom (address goes from 0 to n). The value of each target speed, for each position of the carriage 3, from the deceleration start position P _d at the target stop position P ₀ (e.g., step each of the linear encoder 11) have been set in correspondence with and connecting these A deceleration curve T ₀ from the deceleration start position P _d to the target stop position P ₀ shown in FIG.

The target speed V corresponding to the absolute position X of the carriage 3 is, for example, from the address 5 to the address n + 5 every time an output signal from the linear encoder 11 is given, for example, in the case of the reference deceleration curve T _0. Are sequentially read out by the target speed calculation unit 6c, and the moving speed of the carriage 3 is controlled to be the read target speed V. In other words, toward the deceleration start position P _d at the target stop position P _0, toward the sequential address 5 in the address n + 5, V _{n + 5} from the target velocity V ₅ is sequentially read by the target speed calculating part 6c, as a result, the carriage 3 is subjected to deceleration control so as to draw a deceleration curve T ₀ shown in FIG.

Here, considering the distance from the deceleration start position P _d at the target stop position P _0, the reference range of the target speed table is, for example, so that the sufficient range A ₅ shown in FIG. 6, in this embodiment, As shown in FIG. 6, the target speed table has a table length longer than the necessary range length (the reason will be described later). The address “5” as the reference position number is stored in the internal memory of the PROM 21, EEPROM 23, or DCU 6, and the DCU 6 reads the address “5” to sequentially set the address 5 as the reference start position. Read target speed V up to n + 5.

Next, when the dynamic load of the carriage 3 changes due to some cause, for example, a change in frictional resistance between the carriage 3 and the carriage shaft 32, the stop position of the carriage 3 is as shown in FIG. there is a case in which, as shown shifted to the front and back of the target stop position P _0. Position P ₁ is, showing an example in which the carriage 3 is stopped in front of the target stop position P _0, the position P ₂ is a diagram showing an example in which the carriage 3 is stopped by the over the target stop position P ₀ . That is, when the dynamic load of the carriage 3 is increased, the carriage 3 is stopped before the target stop position P ₀ stalled before the target stop position P _0, the dynamic load of the carriage 3 on the contrary decreases when the carriage 3 will be not be sufficiently decelerated before the target stop position P _0, resulting in over-the target stop position P _0. The trajectories indicated by reference signs T ₁ and T ₂ are trajectories actually drawn by the carriage 3 when the carriage 3 stops at the positions P ₁ and P ₂ (relationship between the target speed V and the absolute position X).

The change in the dynamic load of the carriage 3 changes over time due to changes in temperature, aging, wear of sliding parts, grease consumption, etc. in the relationship between the carriage 3 and the carriage shaft 32 (see FIG. 2). At the same time, it also occurs due to component accuracy, assembly accuracy and the like. When the stop position of the carriage 3 is in front of the target stop position P ₀ as indicated by the position P ₁ , the acceleration section (distance from the target stop position P ₀ to the deceleration start position P _d ) for the next main scanning is short. It becomes, thereby can not be carried out sufficiently acceleration control starts ink discharge before reaching the constant velocity V _a, leading to problems such reducing print quality with.

Hereinafter, means for solving such a problem will be described. CPU16, upon a series of printing operation is finished, the result of the deceleration control of the carriage 3, i.e., the target stop position P ₀ and the deviation amount and a value representing the displacement direction of the stop position of the carriage 3 (hereinafter this "last stop position deviation d) ”is transmitted to the DCU 6 as“ stop position information ”, and the DCU 6 stores this in the internal memory. The previous stop position deviation d may be written to the EEPROM 23 by the CPU 16. Further, when there is no change in the previous stop position deviation d stored in the EEPROM 23, the CPU 16 may not transmit this to the DCU 6. Here, the previous stop position deviation d is, for example, 5 the distance between the target stop position P ₀ shown in (B) and the position P ₁ (step number of the linear encoder 11). Further, in the present embodiment, the previous stop position deviation d when stopping before the target stop position P ₀ is set to a negative value, and conversely, the previous stop position deviation d when exceeding the target stop position P ₀ is set to be positive. Value.

Incidentally, DCU6 occasion of receiving the last stop position deviation d, determines whether the last stop position deviation d has exceeded the threshold value d _max, if not exceed, when updating the previous stop position deviation d, exceeds The previous stop position deviation d is not updated (the reason will be described later).

When the DCU 6 reads the target speed V from the target speed table shown in FIG. 6 at the time of the next deceleration control, the DCU 6 uses the previous stop position deviation d to set the target speed by a predetermined length from an appropriate address in the target speed table. Read V. More specifically, the DCU 6 sets “d + 5” as the read start address from the target speed table during the next deceleration control. For example, when the previous stop position deviation d is “−2” (two steps before the target stop position P ₀ ), the read address n is “3”. In this case, the target speed V is changed from the position of the address 3. Called.

That is, when the read address n in FIG. 6 is read from the "5" as a reference start position is the reference range of the target speed V becomes the range shown by symbol A _5, therefore the previous stop position deviation d "0 "Is maintained in the reference range as it is (range A ₅ ), and when the stop position deviation d is not" 0 ", the reference range of the target speed table is shifted up and down the range A ₅ shown in FIG. Will do. Note that the range A ₀ shows the case of shifting to the top, and the range A ₉ shows the case of shifting to the bottom.

When such a reference range of the target speed table is shifted, the target speed V is changed corresponding to the absolute position X of the carriage 3, from the deceleration start position P _d at the target stop position P _0, the upper as shown in range A ₀ when shifted in the direction, the deceleration curve as shown symbols T ₂ in FIG. 7 is shifted upwards, when shifted downward as shown in range a _9, deceleration as indicated at T ₁ in FIG. 7 The curve shifts downward. Incidentally, the deceleration curve indicated by symbol T ₀ in FIG. 7 is a deceleration curve when the range A ₅ the reference range of the target speed table (deceleration curve as a reference).

By shifting the reference range of the target speed V in the target speed table in this way, the deceleration curve changes and the target speed V corresponding to the absolute position X of the carriage 3 changes. For example, the position in FIG. When the carriage 3 stops before the target stop position P ₀ as indicated by P ₁ , the deceleration curve is changed to a deceleration curve T ₂ shown in FIG. 7 to correspond to the absolute position X of the carriage 3. target speed V is pulled to thereby becomes more accurate as the carriage 3 can be stopped at the target stop position P _0.

Accordingly, even after changing the dynamic load of the carriage 3, the carriage 3 can be accurately stopped at the target stop position P _0, also without changing the target stop position P ₀ before and after the original target stop position Since the carriage 3 can be stopped at the target stop position P ₀ , control by a printer driver in a host control unit such as a host computer that transmits print data to the printer 60 is not complicated.

In the case where the previous stop position deviation d has exceeded the threshold value d _max is DCU6 is not updated the last stop position deviation d, which is due to the following such reasons. That is, when the previous stop position deviation d exceeds the threshold value _dmax , it is considered that some abnormality (for example, the user has forcibly moved the carriage 3) has occurred. The stop position deviation of the carriage 3 is not due to a change in the dynamic load of the carriage 3 or the like. In such a case, it is inappropriate to update the previous stop position deviation d and change the target speed V of the carriage 3 accordingly. That's why.

Subsequently, another embodiment will be described. The target speed V is not determined based on the target speed table described with reference to FIG. 6, but can also be obtained by calculation using a speed function. This will be described below with reference to FIG. Here, FIG. 8 has a deceleration straight line determined by the speed function f (X).

The speed function f (X) is stored in advance in an internal memory (not shown) of the DCU 6. In this embodiment, the speed function f (x) is as follows when the final target speed is _Vb . It has become. V = f (X) = {[(V _a −V _b ) − (d × C)] / (P _d −P ₀ )} · X where the value C is predetermined and stored in the internal memory of the DCU 6 The value d indicates the previous stop position deviation described above. The DCU 6 calculates the target speed V based on such a speed function f (X).

To explain with a specific example, for example, deceleration start speed V _a = 100 (step / msec), final target speed V _b = 10 (step / msec), target stop position P ₀ = 10 (step), deceleration start position When P _d = 110 (step) and the correction coefficient C = 0.95, the speed represents the deceleration straight line S ₀ (reference deceleration straight line) shown in FIG. 8 when the previous stop position deviation d = 0. The function f (X) is V = f (X) = 0.9 · X.

As a result of performing control using this speed function f (X), for example, when the carriage 3 stops at 5 steps before the target stop position P ₀ , the speed function f (X) is V = f (X) = 0. .95 · X Therefore, according to this, the absolute position target velocity V corresponding to X is pulled the carriage 3, it is such decelerated linearly indicated by the letter S ₁ designates 8, thereby, the carriage 3 is more accurately target stop position P ₀ Will be able to stop.

That is, since the speed function f (X) includes the previous stop position deviation d, the previous control result is reflected in the next control, and thereby the carriage 3 is more accurately set to the target stop position P. It can be stopped at _zero .

In the above example, the final target speed of the deceleration straight line S ₁ after the change shown in FIG. 8 is V _b ′. Therefore, the deceleration straight line S ₀ can be changed to the deceleration straight line S ₁ by changing the final target speed V _b ′ itself. For example, when the speed function f (X) indicating the deceleration straight line S ₀ is given by V = f (X) = {(V _a −V _b ) / (P _d −P ₀ )} · X the target speed V _b, 'by multiplying the final target speed V _b' correction value C set in advance to correspond to the value of the last stop position deviation d by changing the value itself, obtaining the deceleration linear S ₁ It is also possible.

Next, still another embodiment will be described. The target speed V is changed by shifting the reference range of the target speed table described with reference to FIG. 6, or the speed function f (X (X) using the previous stop position deviation d described with reference to FIG. ), A plurality of target speed tables may be prepared in advance according to the value of the previous stop position deviation d, whereby the target speed V corresponding to the absolute position X of the carriage 3 may be changed. .

FIG. 9 shows a plurality of target speed tables prepared in advance, and FIG. 10 shows a deceleration curve corresponding to each target speed table. Table length of the target speed table shown in FIG. 9, consist deceleration start position P _d length corresponding to the distance up to the target stop position P ₀ and (addresses 0 to n), the plurality of target speed table Are stored in an internal memory (not shown) of the DCU 6.

For example, when the carriage 3 is stopped before the target stop position P ₀ as a result of performing control using the deceleration curve indicated by the symbol W ₀ in FIG. 10, it corresponds to the value of the previous stop position deviation d. To the preset target speed table. For example, by changing the table (2) from the table (0) in FIG. 9, it becomes a deceleration curve shown by reference numeral W ₂ in FIG. 10, whereby the target speed V corresponding to the absolute position X of the carriage 3 is raised, has can be stopped carriage 3 more accurately at the target stop position P ₀ in.

In FIG. 9, three target speed tables are shown as an example. However, a larger number of target speed tables can be prepared to perform finer control.

By the way, as described above, the previous stop position deviation d is transmitted from the CPU 16 to the DCU 6 at the end of the printing operation as part of a series of printing operations, as described above, and the DCU 6 is stored in the internal memory. The deviation d is updated, but this may be performed independently.

That is, when the control device 100 detects a predetermined condition, the carriage 3 is driven and controlled during the non-printing operation, and the carriage 3 is controlled to decelerate, so that the carriage 3 is accurately stopped at the target stop position P ₀ . Alternatively, a previous stop position deviation d may be updated at a predetermined timing by providing a mode (hereinafter referred to as “measurement mode”) for measuring how much the position has deviated back and forth. In this way, for example, when a considerable time has elapsed from the previous printing operation to the start of the next printing operation, even if a change in the driving load of the carriage 3 occurs during this period, The carriage 3 can be accurately stopped by obtaining the previous stop position deviation d.

As the predetermined condition, for example, when the power supply of the printer 60 is detected, and the measurement mode is executed when the power supply ON is detected, the drive load of the carriage 3 when the printer 60 is not used for a long period of time. Respond appropriately to changes.

Alternatively, as the predetermined condition, it is conceivable that the measurement mode is executed when print data is received, that is, before the start of each printing operation. In such a case, although the print throughput is reduced, it is always the latest. the last can be obtained stop position deviation d, the carriage 3 more accurately with can be stopped at the target stop position P _0.

Furthermore, as a predetermined condition, it may be executed when the replacement of the ink cartridge 34 is detected. In such a case, since the measurement mode is executed after the ink cartridge replacement operation in which the driving load of the carriage 3 is likely to change, the previous stop position after the driving load of the carriage 3 has changed in the printing operation to be executed later. information d can be obtained, it is possible to stop the carriage 3 more accurately at the target stop position P ₀ have.

In the present embodiment, the deceleration control of the carriage 3 as the drive target has been described. However, since the present invention is an invention related to a motor control device, it can also be applied to the PF motor 1 shown in FIG. Needless to say, there is.

In addition, the deceleration control in the target speed calculation unit 6c described so far can be realized by a hardware circuit, or can be realized by a program and a processing device (CPU or the like) that executes the program. The program describing the deceleration control can be provided by being recorded on a computer-readable recording medium such as a floppy disk, a magneto-optical disk, a CD-ROM, or a hard disk.

As described above, according to the present invention, as a result of the deceleration control of the drive target, the motor control device stores the stop position information storage unit that stores the position where the drive target stops as stop position information, and the stop position information. Speed setting means for setting the target speed based on And based on the said stop position information, the said target speed corresponding to the movement position of the said drive target is changed. When the target stop position corresponding to the movement position of the drive target is changed, the stop position of the drive target is changed, and accordingly, the drive target can be accurately stopped at the target stop position, and Since there is no need to change the target stop position, it does not affect the upper control means.

1 is a perspective view illustrating a schematic configuration of an ink-jet printer. FIG. 2 is a perspective view showing in detail a portion of the carriage shown in FIG. 1 and a carriage control device that drives and controls the carriage. It is a block diagram which shows the structure of the control apparatus of a printer. It is a block diagram which shows the part which performs drive control of CR motor in DCU. (A) is a graph which shows the relationship between the target speed and absolute position in the deceleration area of a carriage, (B) is the elements on larger scale of (A). It is a figure which shows a target speed table. It is a graph which shows the relationship between the target speed and absolute position of a carriage at the time of shifting the reference range of a target speed table. It is a graph which shows other embodiment which changes target speed, and shows the relationship between the target speed in the deceleration area of a carriage, and the absolute position of a carriage. It is a figure which shows the target speed table in other embodiment which changes target speed. It is a graph which shows other embodiment which changes target speed, and shows the relationship between the target speed in the deceleration area of a carriage, and the absolute position of a carriage.

Explanation of symbols

3 Carriage, 4 CR motor, 5 CR motor driver, 6 DCU, 11 Linear encoder, 16 CPU, 6a, 6e Subtractor, 6c Target speed calculator, 6d Speed calculator, 6i Adder, 50 Printing paper, 60 Ink jet printer, 100 controller

Claims (7)

A motor for stopping the drive target at a predetermined target stop position by performing deceleration control for controlling the motor to drive the drive target at a predetermined target speed corresponding to the movement position of the drive target. A control device,
Stop position information storage means for storing an actual stop position as stop position information when performing control to stop the drive target at the target stop position;
Speed setting means for setting the target speed based on the stop position information,
By changing the target speed corresponding to the movement position of the drive object by the speed setting means, the stop position of the drive object is changed without changing the target stop position,
The motor control device has a target speed table in which the speed of the motor is set, and a deceleration curve drawn by the target speed corresponding to each position from the position where the deceleration control is started to the target stop position is Determined by the target speed table,
The table length of the target speed table is longer than the table length corresponding to the distance from the position where the deceleration control is started to the target stop position, and the reference range of the target speed table is shifted. The driving object stops at a position before the stop position stored in the stop position information storage means, or stops at a position earlier than the stop position stored in the stop position information storage means. The deceleration curve changes,
The speed setting means shifts the reference range of the target speed table based on the stop position information so that the drive target stops at the target stop position.
The motor control apparatus characterized by the above-mentioned.   2. The motor control device according to claim 1, wherein the speed setting unit has a threshold value for a deviation amount between the stop position of the drive target and the target stop position, and the deviation amount exceeds the threshold value. The motor control device does not change the target speed. A carriage having a recording head for recording on a recording material and provided to reciprocate in the main scanning direction;
A conveyance roller for conveying a recording material to a position facing the recording head;
A recording apparatus having a discharge roller for discharging the recording material recorded by the recording head,
3. A recording apparatus, wherein at least one of a motor for driving the carriage and a motor for driving the transport roller is controlled by the motor control apparatus according to claim 1 or 2.   The recording apparatus according to claim 3, wherein the stop position information is updated every time a recording operation is completed.   5. The recording apparatus according to claim 3, wherein a measurement mode in which the driving target is driven and the stop position information is updated is executed when the recording apparatus is powered on.   5. The recording apparatus according to claim 3, wherein a measurement mode for driving the drive target and updating the stop position information is executed at the time of recording data reception and before the start of the recording operation. Recording device.   5. The recording apparatus according to claim 3, wherein a measurement mode in which the drive target is driven to update the stop position information is executed when the replacement of the ink cartridge mounted on the carriage is detected. Recording device.

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