JP2009234015A - Motor control device, printer and motor control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor control device, capable of ensuring carrying accuracy of a carrying object even if a mechanical load is increased, and thus preventing reversion of carrying speed between two motors, a printer, and a motor control method. <P>SOLUTION: The motor control device comprises a motor 31; a speed calculation means 121 which calculates a driving speed of the motor 31; a motor control means 100 which feedback controls the motor 31 based on a target speed of either a first speed table 102a or a second speed table 102b and the driving speed; a determination means 110 which determines, when the motor 31 is driven based on the first speed table 102a, whether a delay state in which the driving speed of the motor 31 is below a target time only for a predetermined time is established or not; and a table selection means 110 which selects driving based on the second speed table 102b when the delay state is determined. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor control device, a printer, and a motor control method.

  Ink jet printers include a conveyance drive roller for conveying a print medium, a pickup roller for feeding the uppermost printing paper P from a feeding cassette to a printing site, and the like. These are driven by a motor such as a DC motor (the former is a PF motor and the latter is an ASF motor). For the drive control of these motors, PID control using a PWM system is often used. In this PID control, a speed deviation (speed difference) between the target speed and the actual speed is calculated, and a proportional element, an integral element, and a differential element are calculated based on the deviation. Thereby, the control value (Duty ratio) of the motor is determined so as to follow a predetermined speed table (see Patent Document 1).

JP 2001-251878 A

  In general, when a printer is used for a long period of time, the load on various frictional parts (rotating parts, sliding parts, etc.) tends to increase due to grease deterioration, mist adhesion, and various other reasons. As described above, when the mechanical load increases, the duty ratio is increased so as to obtain the rotation speed of the motor according to a predetermined speed table. However, when the mechanical load increases greatly, a state occurs in which the duty ratio cannot be followed even though the duty ratio is close to the maximum value.

  If such a state in which the speed table cannot be followed continues, the print medium stop accuracy deteriorates and the drive time becomes significantly longer than the target value. As a result, the printer may eventually determine that a fatal error has occurred, and the printer may stop.

  Further, when a state in which the PF motor cannot follow a predetermined speed table occurs due to an increase in mechanical load, the amount of print medium fed by the ASF motor becomes larger. As a result, a problem arises in that the print medium is loosened and the print medium comes into contact with the print head.

  The present invention has been made on the basis of the above circumstances, and the object of the present invention is to ensure the printing medium conveyance accuracy even when the mechanical load increases, and between the two motors. An object of the present invention is to provide a motor control device, a printer, and a motor control method capable of preventing the reverse of the conveyance speed.

  In order to solve the above-described problems, the present invention provides a motor that provides a driving force for transporting an object to be transported, a speed calculation unit that calculates a driving speed of the motor, and a first speed table relating to a target speed of the motor for each transport step. And a storage unit for storing a second speed table related to a target speed lower than the first speed table, a target speed of either the first speed table or the second speed table, and a driving speed, Motor control means for feedback-controlling the motor, and determination means for determining whether or not the motor drive speed is in a delay state below the target time for a predetermined time when the motor is driven based on the first speed table; And a table selection unit that selects driving based on the second speed table when it is determined that the state is a delay state.

  In such a configuration, when it is determined that the motor driving speed is in a delay state that is less than the target time for a predetermined time, the table selection unit changes the driving to the driving based on the second speed table. For this reason, even when a mechanical load increases greatly and the load applied to the motor is large and a delay state in which the first speed table cannot be followed occurs, it is possible to follow the second speed table. As a result, it is possible to prevent problems such as deterioration of the conveyance accuracy (stop accuracy) of the object to be conveyed and the driving time being significantly longer than the target value, which occurs due to the delay state continuing. It becomes.

  In another invention, in addition to the above-described invention, the determination means determines whether or not the acceleration region in the first speed table is in a delay state.

  In the above-described case, an acceleration region is absolutely present for each transport step, but when the speed is low, there is no constant speed region. In addition, the speed of the deceleration region may vary depending on the target stop position and the like. Therefore, if it is determined whether or not it corresponds to the delay state in the acceleration region, it is possible to reliably determine whether or not it corresponds to the delay state.

  Furthermore, in another invention, in addition to the above-described invention, the motor control means performs PID control by performing PID calculation for each predetermined cycle, and the predetermined time is stored in the storage unit and the number of PID calculations. The PID count threshold is used.

  In such a configuration, it is possible to measure the time required for the acceleration region to elapse by counting the number of PID calculations. Therefore, it can be determined whether or not the delay state is met.

  In another invention, in addition to the above-described invention, the table selection may be performed when it is determined by the determination means that a delay state has occurred in a transport step that continues for a predetermined threshold number of times set to a value of 2 or more. The second speed table is selected by means.

  In this configuration, when delay information is accidentally issued in a certain transport step, it is possible to prevent the second speed table from being automatically driven, and the second speed table can be driven. It is possible to prevent frequent occurrence. Thereby, it is possible to improve the reliability of motor driving.

  Furthermore, in another invention, in addition to each of the above-described inventions, the object to be conveyed is conveyed by a motor and an upstream motor located upstream of the motor and driven by the upstream motor. An upstream speed calculating means for calculating a speed, and an upstream motor control means for performing feedback control of the upstream motor based on the target speed of either the first speed table or the second speed table and the driving speed. The determination unit determines that the state is a delay state when the drive speed of the upstream motor exceeds the drive speed of the motor.

  In such a configuration, even when the drive speed of the upstream motor exceeds the drive speed of the motor, the motor is controlled and driven by the second speed table, and in addition, the upstream motor is also controlled and driven by the second speed table. It is done. For this reason, it is possible to prevent a problem that the conveyed object is loosened between the motor and the upstream motor.

  In addition, another invention includes a motor control device related to each of the above-described inventions, the transported object is a print medium on which ink based on supply from an ink cartridge is ejected from a print head, and the table selection unit is turned off. At this time, or at the timing of ink cartridge replacement, the drive selection based on the second speed table is changed to the drive selection based on the first speed table.

  In such a configuration, even when a delay occurs in which the load applied to the motor is large and cannot follow the first speed table due to a large increase in mechanical load in the printer, the printer follows the second speed table. Is possible. As a result, it is possible to prevent problems such as deterioration of the conveyance accuracy (stop accuracy) of the object to be conveyed and the driving time being significantly longer than the target value, which occurs due to the delay state continuing. It becomes. In addition, the table selection means changes the selection from the driving based on the second speed table to the driving based on the first speed table at the power-off timing or the ink cartridge replacement timing. It becomes possible to increase the driving speed.

  Furthermore, another invention is based on a speed calculation step for calculating a driving speed of a motor that gives a driving force for transporting the object to be transported, a first speed table for driving the motor, and a target speed of the motor for each transport step. A motor control step for feedback-controlling the motor, a determination step for determining whether or not the motor drive speed is below a target time for a predetermined time, and a first speed table when the delay state is determined. A table selection step of selecting driving based on a second speed table relating to a lower target speed.

  In such a configuration, when it is determined that the motor driving speed is in a delay state that is less than the target time for a predetermined time, the table selection unit changes the driving to the driving based on the second speed table. For this reason, even when a mechanical load increases greatly and the load applied to the motor is large and a delay state in which the first speed table cannot be followed occurs, it is possible to follow the second speed table. As a result, it is possible to prevent problems such as deterioration of the conveyance accuracy (stop accuracy) of the object to be conveyed and the driving time being significantly longer than the target value, which occurs due to the delay state continuing. It becomes.

  Hereinafter, a printer 10 including a motor control device (mainly a control unit 100) and a drive control method according to an embodiment of the present invention will be described with reference to FIGS. Note that the printer 10 of the present embodiment is an ink jet printer, but the ink jet printer may be an apparatus that employs any ejection method as long as the apparatus is capable of printing by ejecting ink.

  In the following description, the lower side refers to the side where the printer 10 is installed, and the upper side refers to the side away from the installed side. Further, the side on which the print medium P is supplied is described as a feeding side (rear end side), and the side on which the print medium P is discharged is described as a paper discharge side (front side).

<Schematic Configuration of Printer 10>
As shown in FIG. 1, the printer 10 includes a housing unit (not shown), a carriage drive mechanism 20, a paper transport mechanism 30, a rear feeding mechanism 40, a PF encoder 50, an ASF encoder 60, and a control unit. 100 is a main component.

  Among these, the carriage drive mechanism 20 includes a carriage 21, a carriage motor (CR motor 22), a belt 23, a gear pulley 24, a driven pulley 25, and a carriage shaft 26. The carriage 21 can be loaded with ink cartridges 27 for each color. As shown in FIGS. 1 and 2, a print head 28 capable of ejecting ink droplets is provided on the lower surface of the carriage 21. The belt 23 is an endless belt, and a part of the belt 23 is fixed to the back surface of the carriage 21. The belt 23 is stretched by a gear pulley 24 and a driven pulley 25.

  The print head 28 according to the present embodiment has a piezo drive system using a piezo element. However, the print head 28 is not limited to a piezo drive system using a piezo element. For example, a heater system that uses ink to heat ink to generate bubbles, a magnetostriction system that uses a magnetostrictive element, and a mist that are controlled by an electric field. A mist method or the like may be employed.

  As shown in FIG. 1 and the like, the paper transport mechanism 30 transports a print medium P or the like as a transported object, a motor and a PF motor 31 (corresponding to the motor) as a transport motor, and transports / A PF roller pair 32 is provided for clamping. The PF roller pair 32 includes a PF drive roller 32a that is rotated by driving the PF motor 31, and a PF driven roller 32b that is biased by the PF drive roller 32a by receiving a biasing force by a spring (not shown).

  On the paper discharge side of the PF roller pair 32, the platen 33 and the above-described print head 28 are arranged so as to face each other vertically. The platen 33 corresponds to the placement unit, and supports the print medium P conveyed below the print head 28 by the PF roller pair 32 from below. Further, on the paper discharge side with respect to the platen 33, a paper discharge roller pair 34 similar to the above-described PF roller pair 32 is provided. The driving force from the PF motor 31 is transmitted to the paper discharge driving roller 34a of the paper discharge roller pair 34 together with the PF driving roller 32a. The CR motor 22, the PF motor 31, and the ASF motor 42 described later are DC motors.

  As shown in FIGS. 1 and 2, the rear feeding mechanism 40 includes a hopper 41, an ASF motor 42, a feeding roller 43, and a retard roller 44. The hopper 41 is a portion on which the lower side of the print medium P is placed. The hopper 41 receives a biasing force of a hopper spring (not shown), and is provided so as to be able to swing around the pivot fulcrum 41a on the upper end side. By this swing, the printing medium P is pressed against the feeding roller 43. The separating operation is realized.

  The ASF motor 42 (corresponding to the upstream motor) is a motor that provides a driving force for rotating the feeding roller 43. The feeding roller 43 feeds the uppermost printing medium P in contact with the downstream side by rotating while being in contact with the printing medium P pushed up by the hopper 41. The retard roller 44 is provided so as to be capable of advancing and retreating with respect to the feeding roller 43 and given a predetermined rotational resistance by a torque limiter mechanism. Accordingly, when a plurality of print media P are interposed between the feed roller 43 and the retard roller 44, the rotational resistance is greater than the frictional force between the print media P that overlap, so that the retard roller 44 Remains stopped, and the subsequent feeding of the print medium P is prevented. However, when only one print medium P is interposed between the feed roller 43 and the retard roller 44, the retard roller 44 is driven to rotate with respect to the feed roller 43, and the print medium P is sent downstream. .

  As shown in FIG. 1, the PF encoder 50 detects the rotational speed of the PF motor 31, and includes a disk-shaped scale 51 and a rotary sensor 52. The disk-shaped scale 51 is rotated by the PF motor 31 and has a light-transmitting part that transmits light and a light-blocking part that blocks light transmission at regular intervals along the circumferential direction of rotation. Yes. The rotary sensor 52 is an optical sensor having a light emitting element (not shown) and a light receiving element (not shown) as main components. Among these, the A-phase and B-phase pulse signals whose phases are shifted from each other by 90 degrees are output from the light receiving element to the ASIC 104 described later.

  The ASF encoder 60 detects the rotational speed of the ASF motor 42, and includes a disk-shaped scale 61 and a rotary sensor 62. Since the ASF encoder 60 has the same configuration as the PF encoder 50, the description thereof is omitted.

  The printer 10 also includes a linear encoder 70 that calculates the movement distance of the carriage 21, a paper width detection sensor that detects the width of the print medium P, and a gap detection sensor that detects the distance between the print head 28 and the platen 33. And other sensors.

<Configuration of control unit>
Next, the control unit 100 will be described with reference to FIG. The control unit 100 is a part that performs various controls. The control unit 100 receives output signals from the rotary sensors 52 and 62, a paper width detection sensor (not shown), a gap detection sensor (not shown), a power switch for turning on / off the printer 10, and the like.

  As shown in FIG. 3, the control unit 100 includes a central processing unit (CPU) 101, a memory 102, an interface 103, an application specific integrated circuit (ASIC) 104, a bus 105, a timer 106, a PF motor driver 107, and an ASF motor driver 108. Have The control unit 100 includes a speed calculation unit (mainly a PF speed calculation unit 121), a storage unit (memory 102), a motor control unit, a determination unit (mainly a PID count unit 112, a continuous number count unit 113, Main control unit 110), table selection means (mainly main control unit 110), upstream speed calculation means (mainly ASF speed calculation unit 122), and upstream motor control means.

  The CPU 101 operates according to a control program stored in the memory 102. The memory 102 has a RAM and a ROM, and a control program is stored in the ROM in advance. When the CPU 101 executes the control program, a main control unit 110, a PID calculation unit 111, a PID count unit 112, a continuous number count unit 113, and a speed comparison unit 114 are realized.

  Of these, the main control unit 110 is a part that governs overall motor control. When the PID calculation is instructed, or when the limit number described later is reached in the continuous number counting unit 113, or the speed comparison unit 114. When the rotation speed of the ASF motor 42 is determined to be higher, a command for changing the speed table is given.

  When PID calculation is instructed, the PID calculation unit 111 performs PID calculation for PID control at predetermined timings based on the timer 106 based on the speed table specified by the main control unit 110. Execute.

  The PID count unit 112 is a part that counts the number of times PID calculation has been performed (PID interrupt count). Here, in the present embodiment, the number of PID calculations (PID interrupt count) is counted in the acceleration region in the first speed table 102a in FIG. This is because an acceleration region absolutely exists for each transport step, but when the speed is low, there is no constant speed region. In addition, the speed of the deceleration region may vary depending on the target stop position and the like. Therefore, the number of PID calculations is counted by the PID counting unit 112 only in the acceleration region in the first speed table 102a.

  Further, in the PID count unit 112, when the count value reaches the PID count threshold value 102c (corresponding to a predetermined time) delivered from the memory 102, information indicating that the delay speed is reached (delay information; one of the delay states). Is transferred to the continuous number counting unit 113, and thereafter, the PID calculation is not counted in the transport step. In addition, when counting is started in a new transport step, and when the count value in the PID count unit 112 does not reach the count threshold value 102c, the count value is reset to zero in the PID count unit 112. Note that the PID count threshold 102c is a large value, for example, 500 times.

  The continuous number counting unit 113 is a part to which the conveyance step information and the delay information are transferred from the PID counting unit 112, and is a part for counting the number of times the delay information is transferred in successive conveyance steps. When the number of times the delay information is delivered reaches the speed limit threshold 102d (corresponding to the predetermined threshold), information indicating that the speed limit condition (corresponding to the delay state) is satisfied is passed to the main control unit 110. Note that when the transport step information is delivered and the delay information is delivered, the continuous number counting unit 113 counts up, but even if the transport step information is delivered, the delay information is not delivered. In the case (when no delay information is generated in the transport step), the count value is reset to zero.

  The speed comparison unit 114 compares the rotation speed (paper feed speed) of the PF motor 31 with the rotation speed (paper feed speed) of the ASF motor 42. In this comparison, when it is determined that the rotational speed of the ASF motor 42 is faster than the rotational speed of the PF motor 31, information to that effect is transferred to the main control unit 110.

  The memory 102 stores a first speed table 102a, a second speed table 102b, a PID number threshold 102c, and a speed limit threshold 102d. Among these, the first speed table 102a is a normal speed table in a state where the PF motor 31 has not reached the speed limit. The above-described PID calculation unit 111 performs PID control based on the first speed table 102a. The second speed table 102b is a speed table in a state where the PF motor 31 has reached the speed limit. When the PF motor 31 is driven based on the second speed table 102b, the speed is lower than the driving by the first speed table 102a.

  The PID count threshold 102c is a threshold for determining whether or not the number of PID calculations in the acceleration region is an output of delay information. That is, since the PID calculation is executed every predetermined PID cycle (corresponding to the predetermined cycle), when the number of PID interruptions is large in the acceleration region, the rotation speed of the PF motor 31 becomes slow, and the state is determined. The threshold for this is the PID count threshold 102c. The speed limit threshold value 102d is a threshold value for determining whether or not the number of delay information receptions has reached a predetermined limit number. Here, the speed limit threshold value 102d is a value of 2 or more. In this case, when delay information is received only once, there may be a case in which delay information is accidentally issued in the transport step, so the value of two or more times is used as a threshold value.

  The interface 103 has a function of converting a signal format and the like so that the control unit 100 and the computer 130 are electrically connected and information can be transmitted and received between them. The ASIC 104 includes a PF speed calculation unit 121, an ASF speed calculation unit 122, a PF motor control unit 123, and an ASF motor control unit 124.

  In the ASIC 104, the PF speed calculation unit 121 and the ASF speed calculation unit 122 measure the period between the edges of the ENC signal output from the rotary sensors 52 and 62, respectively, and based on the period measurement, the PF motor 31 and the ASF The rotational speed of the motor 42 is calculated. Further, the PF motor control unit 123 and the ASF motor control unit 124 respectively output control signals for controlling the PF motor 31 and the ASF motor 42 based on the control commands from the CPU 101. In the present embodiment, the PF motor control unit 123 and the ASF motor control unit 124 respectively output a PWM (Pulse Width Modulation) signal having a duty ratio corresponding to the rotation amounts of the PF motor 31 and the ASF motor 42.

  The timer 106 measures time by counting clock signals (not shown). When a preset time is reached by this count, an interrupt signal is output to the CPU 101.

  The PF motor driver 107 and the ASF motor driver 108 apply pulse voltages corresponding to a predetermined duty ratio to the PF motor 31 and the ASF motor 42 based on control signals from the PF motor control unit 123 and the ASF motor control unit 124, respectively. Output each.

<About motor drive control (1)>
A case where the motor control is performed in the printer 10 having the above-described configuration will be described below based on the operation flow of FIG.

  If the CPU 101 issues a drive command to the PF motor 31 when the printer 10 is turned on, for example, when printing is performed, the PF motor 31 is driven according to the first speed table 102a as shown in FIG. (S01). As a result, the PID calculation unit 111 performs PID calculation in the acceleration region (S02). Accordingly, the PF motor 31 is controlled and driven by PID control based on the speed deviation ΔV between the target speed and the current speed so that the PF motor 31 converges on the first speed table 102a shown in FIG. To be controlled. Here, when the load applied to the PF motor 31 is large, the value of the speed deviation ΔV is large, so that the control command value output from the PID calculation unit 111 increases the duty ratio.

  However, when the mechanical load of the printer 10 is large, the PF motor 31 cannot follow the first speed table 102a even though the duty ratio is maximized, as indicated by a one-dot chain line in FIG. Occurs. Here, since the PID calculation arrives at every predetermined PID cycle, the time required until the end of the acceleration region can be calculated based on the number of PID calculations. Therefore, the CPU 101 determines whether or not the number of PID calculations in the acceleration region has reached the PID number threshold 102c (S03).

  In the above determination, when it is determined that the number of PID calculations has reached the PID number threshold 102c (in the case of Yes), the mechanical load is large, which corresponds to the state of the one-dot chain line in FIG. In this case, the PID count unit 112 outputs delay information to the continuous number counting unit 113 (S04). Accordingly, the continuous number counting unit 113 counts the number of times delay information is input.

  Subsequently, it is determined whether or not the count value in the continuous number counting unit 113 has reached the speed limit threshold 102d (S05). As described above, the continuous number counting unit 113 resets the count value in the continuous number counting unit 113 to zero when no delay information is input in the next transport step. Therefore, the state in which the count value in the continuous number counting unit 113 reaches the speed limit threshold value 102d is not only able to follow the first speed table 102a in a specific transport step, but also in the transport step that follows the first speed table. This corresponds to a state in which it cannot follow 102a.

  Therefore, when it is determined in S05 described above that the speed limit threshold value 102d has been reached (in the case of Yes), the continuous number counting unit 113 passes information indicating that the speed limit condition is satisfied to the main control unit 110 ( S06). Then, the main control unit 110 drives the PF motor 31 in the speed limit mode from the next transport step (S07). That is, the PF motor 31 is driven so as to converge on the second speed table 102b.

  If it is determined in S03 that the number of PID calculations has not reached the PID number threshold (in the case of No), it is determined in S05 that the delay information count value has not reached the speed limit threshold 102d. If yes (No), the process proceeds to S09 described below.

  In the present embodiment, main controller 110 determines whether or not the condition for canceling speed limit mode is satisfied (S08). Here, the release condition in the present embodiment corresponds to the case where the printer 10 is newly turned on and the ink cartridge 27 is replaced. If it is determined that the release condition is satisfied (Yes), the speed limit mode is released (S09). When it is determined that the release condition is not satisfied (in the case of No), the speed limit mode is not released and remains as it is.

<About motor drive control (2)>
Next, another motor control in the present invention will be described with reference to FIG. Note that the operation flow of FIG. 6 has many parts in common with the operation flow of FIG. However, in the flow of FIG. 6, as a new step, the speed comparison unit 114 determines whether or not the driving speed of the ASF motor 42 exceeds the driving speed of the PF motor 31 (S10). This determination is made in order to prevent a situation in which the PF motor 31 cannot follow the first speed table 102a, the feed amount of the print medium P by the ASF motor 42 becomes larger, and the print medium P becomes slack. Is provided.

  When it is determined in S10 described above that the driving speed of the ASF motor 42 exceeds the driving speed of the PF motor 31 (in the case of Yes), the process proceeds to S06 described above, and the main control unit 110 limits the speed. Outputs that the condition is met. If it is determined in S10 that the driving speed of the ASF motor 42 does not exceed the driving speed of the PF motor 31 (No), the process proceeds to S09 described above and is driven based on the first speed table 102a. Is done.

<Effects of the present invention>
According to the printer 10 configured as described above, when it is determined that the speed limit condition is satisfied in the PF motor 31, the driving is changed to the driving based on the second speed table 102b. For this reason, even if a mechanical load increases significantly and the load applied to the PF motor 31 is large and a delay state that cannot follow the first speed table 102a occurs, the second speed table 102b can be followed. Become. As a result, it is possible to prevent problems such as deterioration in the conveyance accuracy (stop accuracy) of the print medium P caused by continuing the delay state and the drive time being significantly longer than the target value. It becomes.

  Further, it is determined whether or not a delay state is satisfied in the acceleration region of the first speed table 102a. Here, although the acceleration region absolutely exists for each conveyance step, there is no constant speed region when the speed is low. In addition, the speed of the deceleration region may vary depending on the target stop position and the like. Therefore, if it is determined whether or not the acceleration state corresponds to the delay state, it is possible to reliably determine whether or not the PF motor 31 corresponds to the speed limit condition.

  Furthermore, by counting the number of PID calculations by the PID counting unit 112, it is possible to measure the time required for the acceleration region to elapse. Therefore, it is possible to easily determine whether or not the delay state is satisfied.

  Further, by counting the delay information by the continuous number counting unit 113, it is possible to prevent the second speed table 102b from being automatically driven when the delay information is accidentally issued in a certain transport step. It becomes possible. As a result, frequent driving of the second speed table 102b can be prevented, and the driving reliability of the PF motor 31 can be improved.

  Furthermore, in the speed comparison unit 114, even when the driving speed of the ASF motor 42 exceeds the driving speed of the PF motor 31, the PF motor 31 and the ASF motor 42 are controlled and driven by the second speed table 102b. For this reason, it is possible to prevent a problem that the print medium P is loosened between the PF motor 31 and the ASF motor 42 and the print medium P contacts the print head 28.

  In this embodiment, the selection is changed from driving based on the second speed table 102b to driving based on the first speed table 102a at the timing of turning off the power of the printer 10 or the timing of replacing the ink cartridge 27. Therefore, the driving speed of the PF motor 31 can be increased at the timing.

<Modification>
Although one embodiment of the present invention has been described above, the present invention can be variously modified. This will be described below.

  In the above-described embodiment, the case where a DC motor is used as the PF motor 31 and the ASF motor 42 has been described. However, these motors are not limited to DC motors, and stepping motors may be used when, for example, motor noise does not matter so much. Also, an AC (alternating current) motor such as a synchronous motor may be used.

  In addition, the control unit 100 in the above-described embodiment may be realized in a circuit or software. Further, the control unit 100 may be configured by combining a one-chip microcomputer or the like in which various peripheral devices are incorporated.

  In the above-described embodiment, the print medium P is a transported object. However, the object to be conveyed is not limited to the print medium P. For example, a workpiece in various manufacturing apparatuses may be the object to be conveyed.

  In the above-described embodiment, the case where the motor control device is provided in the ink jet printer 10 is described as an example. However, the motor control device is not limited to being provided in the printer 10, and the motor control device of the present invention may be applied to a scanner device, a copy device, various recording devices, and the like. The printer is not limited to the ink jet printer 10 as long as it can eject fluid. For example, the present invention can be applied to various printers such as a gel jet printer, a toner printer, and a dot impact printer. Further, the printer 10 in the above-described embodiment may be a part of a complex device such as a configuration having functions (scanner function, copy function, etc.) other than the printer function.

  Furthermore, in the above-described embodiment, only PID control is described in the acceleration region of the first speed table 102a. However, the movement of the PF motor 31 is not limited to PID control, and may be open control. Furthermore, the feedback control is not limited to PID control, and the present invention can be applied to various feedback controls such as PI control and P control.

1 is a diagram illustrating a schematic configuration of a printer according to an embodiment of the present invention. FIG. 2 is a side view illustrating a schematic configuration of a main part of the printer of FIG. 1. It is a block diagram which shows the structure of a control part. It is a figure which shows each speed table memorize | stored in memory. It is a figure which shows the operation | movement flow in the case of performing motor control. It is a figure which shows the operation | movement flow which added the comparison of ASF speed and PF speed.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printer, 20 ... Carriage drive mechanism, 30 ... Paper conveyance mechanism, 31 ... PF motor (corresponding to motor), 40 ... Rear feeding mechanism, 42 ... ASF motor (corresponding to upstream motor), 50 ... PF encoder, 60 ... ASF encoder, 100 ... control unit, 101 ... CPU, 102 ... memory (corresponding to storage unit), 104 ... ASIC, 106 ... timer, 110 ... main control unit, 111 ... PID calculation unit, 112 ... PID count unit, 113 ... Continuous number counting unit, 114 ... Speed comparison unit, 121PF speed calculation unit, 122 ... ASF speed calculation unit, 123 ... PF motor control unit, 124 ... ASF motor control unit

Claims (7)

A motor for providing a driving force for conveying the object to be conveyed;
Speed calculating means for calculating the driving speed of the motor;
A storage unit for storing a first speed table related to the target speed of the motor for each conveyance step and a second speed table related to a target speed lower than the first speed table;
Motor control means for feedback-controlling the motor based on the target speed of either the first speed table or the second speed table and the driving speed;
Determining means for determining whether or not the driving speed of the motor is in a delay state below the target time for a predetermined time when the motor is driven based on the first speed table;
A table selection unit that selects driving based on the second speed table when it is determined that the delay state is present;
A motor control device comprising:   The motor control device according to claim 1, wherein the determination unit determines whether or not the delay state is set in an acceleration region in the first speed table. The motor control means performs PID control by performing PID calculation every predetermined period,
The predetermined time is stored in the storage unit and is a PID number threshold relating to the number of PID calculations.
The motor control device according to claim 2.   When the determination means determines that the delay state has occurred in the transport step that continues for a predetermined threshold number of times set to a value of 2 or more, the table selection means selects the second speed table. The motor control apparatus according to claim 2 or 3, wherein The transported object is transported by the motor and an upstream motor located upstream of the motor, and
Upstream speed calculating means for calculating the driving speed of the upstream motor;
Upstream motor control means for feedback-controlling the upstream motor based on the target speed of either the first speed table or the second speed table and the driving speed;
With
In the determination unit, when the drive speed in the upstream motor exceeds the drive speed of the motor, it is determined that the delay state is present.
The motor control device according to claim 1, wherein the motor control device is a motor control device. While comprising the motor control device according to any one of claims 1 to 5,
The transported object is a print medium on which ink based on supply from an ink cartridge is ejected from a print head,
The table selection means changes from drive selection based on the second speed table to drive selection based on the first speed table at power-off timing or ink cartridge replacement timing.
A printer characterized by that. A speed calculating step for calculating a driving speed of a motor that applies a driving force for transporting the object to be transported;
A motor control step of driving the motor and feedback-controlling the motor based on a first speed table relating to a target speed of the motor for each conveyance step;
A determination step of determining whether or not the driving speed of the motor is in a delay state below the target time by a predetermined time;
A table selection step of selecting driving based on a second speed table related to a target speed lower than the first speed table when it is determined that the delay state is present;
A motor control method comprising:

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