JP2006247919A - Printer, and driving controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer and a driving controlling method by which a motor can accurately be stopped at a target stopping position by a simple operation. <P>SOLUTION: This printer 10 executes printing to a printing object 12. A body 30 to be driven is driven by the motor 25, driving information based on a control command is given to the motor 25 by a motor controlling means 76, and the driving of the motor 25 is controlled. Also, the position of the body 30 to be driven is measured by measuring means 36, 37 and 76. In a storage means 80, stoppage inclination correcting information for correcting a slipping amount between the central position of the unevenness of accumulated stopped positions from the past to the present time of the body 30 to be driven, and the target stopping position of the body 30 to be driven at the time of the stoppage is stored. In addition, the motor controlling means 76 corrects the driving information by the stoppage inclination correcting information stored in the storage means 80, and the motor 25 is controlled and driven by using the driving information corrected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printer and a drive control method.

  In recent years, ink jet printers have been improved in print quality. In such a printer, when a printing object is fed and printing is performed, the carriage is driven by a carriage motor (hereinafter referred to as a CR motor). Along with this driving, the print head is driven during the movement of the carriage, and ink droplets are ejected to a desired position of the printing object.

  In addition, as a CR motor for driving the carriage, a DC motor having a commutator and a brush is often used because of cost and ease of control. This DC motor has a region controlled by PID control, and when the carriage approaches the target stop position, the voltage applied to the CR motor is reduced to decelerate the carriage, and the target stop position is reached. Stopped.

  By the way, even if the carriage is stopped at the target position due to variations in the inertia (moment of inertia), load, motor current value, etc., the carriage may deviate from the target stop position. Therefore, as a technique for correcting such a deviation, there is one disclosed in Patent Document 1. According to the technical content disclosed in Patent Document 1, the inertia which is a control target is calculated based on the current value and acceleration applied to the motor, and the current control applied to the motor is controlled using the calculated inertia. Is going.

Japanese Patent Laid-Open No. 2001-169584 (see abstract, paragraph numbers 0047 to 0051, etc.)

  By the way, in the technical content of the above-mentioned patent document 1, it is necessary to know a current value directly. Therefore, a means (circuit) for detecting the current value or directly controlling it is necessary. However, in current printers, PWM control is often used, and in this case, drive control of the CR motor is performed only by controlling the pulse width of the voltage pulse.

  When driving control of the CR motor is performed by voltage control by adjusting the voltage pulse, the current flowing through the CR motor cannot be directly controlled. Here, even when the voltage control is performed, it is possible to calculate the current value based on the characteristics of the CR motor, the detection of the encoder, and the like. However, in this case, the counter electromotive force in the CR motor, the resistance variation of the coil existing in the CR motor, and the like must be taken into consideration, and the calculation of the inertia based on the current value and the acceleration becomes very complicated. Even if the inertia is calculated by calculation, the calculation result often includes an error due to the above-described back electromotive force and coil resistance variation, and the carriage is accurately placed at the target stop position. It is difficult to stop.

  The present invention has been made on the basis of the above circumstances, and an object thereof is to provide a printer and a drive control method capable of accurately stopping a motor at a target stop position by simple calculation. To do.

  In order to solve the above-described problems, the present invention provides a motor, a driven body driven by the motor, and drive information based on a control command to the motor in a printer that performs printing on an object to be printed. A motor control means for controlling the driving of the motor, a measuring means for measuring the position of the driven body, a center position of the cumulative stop position variation of the driven body from the past to the present, and the driven position at the time of the stop. Storage means for storing stop tendency correction information for correcting the amount of deviation from the target stop position of the drive body, and the motor control means uses stop tendency correction information stored in the storage means. The drive information is corrected, and the motor is controlled and driven based on the corrected drive information.

  In such a configuration, when a control command is received from the motor control means and the motor is controlled, the stop tendency correction information stored in the storage means is read. Then, the motor control means corrects the drive information of the motor based on the stop tendency correction information, and the motor is controlled and driven based on the corrected drive information.

  In this way, by correcting the motor drive information with the stop tendency correction information, it is possible to eliminate the shift of the central position of the accumulated stop position variation from the past to the present of the driven body. That is, by applying the above-described stop tendency correction information, the center position of the stop position variation can be matched with the target stop position. Therefore, the habit of the stop position due to the mechanical cause of each printer can be eliminated, and the probability that the driven body stops at the target stop position can be improved. As a result, the accuracy of the stop position of the driven body can be improved, and the print quality can be improved.

  Further, by performing the correction as described above, it is possible to further reduce the cost of the printer. That is, in order to eliminate the stop position variation, it is necessary to improve the parts accuracy and assembly accuracy of the printer, but it is possible to eliminate individual differences in the stop position of the driven body without such accuracy improvement. It becomes possible. As a result, the cost of the printer can be reduced by the amount required for improving the component accuracy, the assembly accuracy, and the like.

  According to another aspect of the present invention, in a printer that performs printing on a print target, a motor, a driven body driven by the motor, and drive information based on a control command are given to the motor, and the motor A motor control means for controlling the driving; and a measuring means for measuring the position of the driven body. The motor control means gives drive information based on a control command for stopping the motor after the motor is driven. After the driving body stops, to calculate the amount of deviation between the actual stop position and the target stop position of the driven body at the time of stopping based on the measurement result of the measuring means, to eliminate this deviation amount The latest correction information is calculated, the drive information is corrected using the latest correction information, and the motor is controlled and driven based on the corrected drive information.

  In such a configuration, when the control command is received from the motor control means and the motor is stopped, the stop position of the driven body is measured by the measurement means. Then, the motor control means calculates a deviation amount between the actual stop position and the target stop position of the driven body, and calculates the latest correction information for eliminating this deviation amount. Then, the driving information of the motor is corrected based on the latest correction information, and the motor is controlled and driven based on the corrected driving information.

  In this way, by correcting the motor drive information with the latest correction information, it is possible to eliminate the deviation amount between the actual stop position and the target stop position in the immediate vicinity of the driven body. That is, by applying the latest correction information, the actual stop position of the driven body can be matched with the target stop position. For this reason, even if the printer undergoes a sudden change in the situation (for example, a sudden change in ambient temperature, grease breakage in the drive transmission portion, ink solidification, dust adhering to the drive portion, etc.) If the correction is made, it is possible to cope with the change in the situation, and it is possible to eliminate the deviation of the actual stop position from the target stop position. As a result, the accuracy of the stop position of the driven body can be improved, and the print quality can be improved.

  Further, by performing the correction as described above, it is possible to further reduce the cost of the printer. That is, in order to cope with a change in the situation of the printer, it is necessary to take various mechanical measures assuming the change of the situation. However, individual differences in the stop position of the driven body can be eliminated without such mechanical measures. As a result, the cost of the printer can be reduced by the amount required for mechanical measures.

  Furthermore, another invention provides a printer that performs printing on an object to be printed, a motor, a driven body driven by the motor, and drive information based on a control command to the motor, thereby driving the motor. Motor control means for controlling, measuring means for measuring the position of the driven body, central position of the cumulative stop position variation of the driven body from the past to the present, and the target stop of the driven body at the time of the stop Storage means for storing stop tendency correction information for correcting the amount of deviation from the position, and the motor control means corrects the drive information with the stop tendency correction information stored in the storage means. Then, the motor is controlled and driven based on the corrected drive information, and after the motor is driven, the drive information based on the control command for stopping the motor is given, and the driven body is stopped. Based on the measurement result of the means, calculate the amount of deviation between the actual stop position and the target stop position of the driven body at the time of the stop, and calculate the latest correction information for eliminating this amount of deviation, The drive information is corrected with the latest correction information, and the motor is controlled and driven based on the corrected drive information.

  In such a configuration, when the motor is controlled and driven by a control command from the motor control means, the stop tendency correction information stored in the storage means is read. Then, the motor control means corrects the drive information of the motor based on the stop tendency correction information, and the motor is controlled and driven based on the corrected drive information. Thereafter, when the motor is stopped by a control command from the motor control means, the stop position of the driven body is measured by the measurement means. Then, the motor control means calculates a deviation amount between the actual stop position and the target stop position of the driven body, and calculates the latest correction information for eliminating this deviation amount. Then, the driving information of the motor is corrected based on the latest correction information, and the motor is controlled and driven based on the corrected driving information.

  Thus, by correcting the drive information of the motor by the stop tendency correction information, it is possible to eliminate the deviation of the central position of the cumulative stop position variation from the past to the present of the driven body, The center position of the variation of the stop position can be matched with the target stop position. Therefore, the habit of the stop position due to the mechanical cause of each printer can be eliminated, and the probability that the driven body stops at the target stop position can be improved. In addition, by correcting the drive information of the motor with the latest correction information, the deviation amount between the actual stop position and the target stop position in the immediate vicinity of the driven body can be eliminated, and the actual state of the driven body It is possible to make the stop position coincide with the target stop position. For this reason, even if the printer undergoes a sudden change in the situation (for example, a sudden change in ambient temperature, grease breakage in the drive transmission portion, ink solidification, dust adhering to the drive portion, etc.) If the correction is made, it is possible to cope with the change in the situation, and it is possible to eliminate the deviation of the actual stop position from the target stop position. As a result, the accuracy of the stop position of the driven body can be improved, and the print quality can be improved.

  Further, by performing each correction as described above, it is possible to further reduce the cost of the printer. That is, in order to eliminate the variation in the stop position, it is necessary to improve the accuracy of parts of the printer, the assembly accuracy, etc. In addition, in order to cope with the change in the situation of the printer, the situation change is assumed, It is necessary to take various mechanical measures. However, individual differences in the stop position of the driven body can be eliminated without such accuracy improvement and mechanical measures. As a result, the cost of the printer can be reduced by the amount required for parts accuracy, assembly accuracy, and mechanical measures.

  In another invention, in addition to the above-described invention, the driven body is a carriage on which a print head is mounted, and the motor is a carriage motor that moves the carriage. In the case of such a configuration, when the carriage is driven by the carriage motor, the deviation of the actual stop position with respect to the target stop position of the carriage can be reduced. As a result, the accuracy of the carriage stop position can be improved, and the print quality can be improved.

  Furthermore, in addition to the above-described invention, in another invention, correction of drive information based on stop tendency correction information, latest correction information, or both stop tendency correction information and latest correction information is performed at both end portions of the reciprocation of the carriage. This is done at an existing stop position.

  When configured in this manner, the accuracy of the carriage stop position can be improved at the stop positions present at both ends of the carriage in the main scanning direction. Thereby, it is possible to further improve the print quality.

  According to another invention, in addition to the above-mentioned invention, the motor control means performs drive control of the motor based on the stop tendency correction information at the beginning of driving of the motor, and after the drive has elapsed. The driving control of the motor is performed in a state where the latest correction information is weighted more than the stop tendency correction information.

  In such a configuration, at the initial stage of driving the motor, the driving information for driving the motor is corrected based on the stop tendency correction information. However, after the initial stage, the amount of deviation between the actual stop position and the target stop position is measured by the measuring means. Further, in a printer, the influence of the latest situation change (for example, ambient temperature change, ink solidification, etc.) is more likely to occur than the tendency of the stop position over a long period of time. Therefore, by weighting the latest correction information rather than the stop tendency correction information, the latest situation change can be strongly reflected, and the accuracy of the stop position of the driven body can be improved.

  Furthermore, in another invention, in addition to the above-described invention, the latest correction information changes the weighting as the operation time of the motor elapses. When configured in this manner, it is possible to cope with changes in the status of the printer, such as changes in the temperature of the printer and ink viscosity, which occur as time elapses after the printer is turned on. That is, at the initial stage of power-on of the printer, for example, because the ambient temperature is low and the ink is solidified, the drive load of the printer is large, but as the time from power-on elapses, the printer itself generates heat. The situation surrounding the printer also changes due to the elimination of ink solidification caused by ink ejection. For this reason, if the weighting for the latest correction information is changed in accordance with the change in the situation, even if the time from the printer power-on becomes longer, the stop position accuracy of the driven body can be improved during the power-on. Can be secured.

  According to another invention, in addition to the above-described inventions, the measuring means further includes an encoder for measuring the position of the carriage at each time. In such a configuration, the stop position of the carriage can be accurately measured by using an encoder. In addition, since the printer is usually provided with an encoder such as a linear encoder, it is not necessary to provide a dedicated measuring device for the printer, and the increase in cost can be suppressed.

  Furthermore, in another invention, in addition to each of the above-described inventions, the stop tendency correction information or the latest correction information is information for changing the timing of changing the voltage value applied to the motor. As described above, when the timing for changing the voltage value is changed, the stop position of the driven body also changes accordingly. That is, if the timing for changing the voltage value is changed, the stop position of the driven body can be changed, and the accuracy of the stop position of the driven body can be improved.

  Further, in addition to the above-described invention, in another invention, the motor is controlled and driven by PWM control, and the motor control means changes the voltage value by changing the duty ratio in the PWM control. It is.

  When configured in this manner, the voltage control of the motor can be easily and accurately performed by the PWM control that adjusts the duty ratio of the pulse voltage. In addition, by performing PWM control, it is possible to increase the power efficiency.

  Furthermore, another invention relates to a drive control method for executing printing on a print object while moving the driven body by driving a motor, from the past to the present of the driven body stored in the storage means. A reading process of reading stop tendency correction information for correcting a deviation amount between the center position of the cumulative stop position variation and the target stop position of the driven body at the time of stop, and the stop tendency correction information, A first correction step for correcting the drive information; an initial drive step for performing initial driving of the motor and stopping the driven body with respect to the target stop position based on the drive information corrected by the first correction step; Based on the measurement process of measuring the amount of deviation between the position where the driven body actually stopped in the initial drive process and the target stop position using the measurement means, and the measurement result in the measurement process, And immediate correction information calculation step of calculating the most recent correction information for eliminating the amount of which, by the last correction information, and a second correction step of correcting the driving information, those having a.

  In the case of such a configuration, a deviation between the center position of the cumulative stop position variation of the driven body from the past to the present and the target stop position of the driven body at the time of the stop by the reading process. Stop tendency correction information for correcting the amount is read from the storage means. In the first correction step, drive information for driving the motor is corrected based on the stop tendency correction information. In the initial driving process, the motor is initially driven based on the driving information corrected in the first correcting process, and the driven body is stopped toward the target stop position. Further, in the measurement step, the amount of deviation between the position where the driven body actually stops in the initial drive step and the target stop position is measured by the measurement means. In the latest correction information calculation step, the latest correction information for eliminating the above-described deviation amount is calculated based on the measurement result in the measurement step. In the second correction step, the drive information is corrected by the latest correction information.

  Thus, by correcting the drive information of the motor by the stop tendency correction information, it is possible to eliminate the deviation of the central position of the cumulative stop position variation from the past to the present of the driven body, The center position of the variation of the stop position can be matched with the target stop position. Therefore, the habit of the stop position due to the mechanical cause of each printer can be eliminated, and the probability that the driven body stops at the target stop position can be improved. In addition, by correcting the drive information of the motor with the latest correction information, the deviation amount between the actual stop position and the target stop position in the immediate vicinity of the driven body can be eliminated, and the actual state of the driven body It is possible to make the stop position coincide with the target stop position. For this reason, even if the printer undergoes a sudden change in the situation (for example, a sudden change in ambient temperature, grease breakage in the drive transmission portion, ink solidification, dust adhering to the drive portion, etc.) If the correction is made, it is possible to cope with the change in the situation, and it is possible to eliminate the deviation of the actual stop position from the target stop position. As a result, the accuracy of the stop position of the driven body can be improved, and the print quality can be improved.

  Further, by performing each correction as described above, it is possible to further reduce the cost of the printer. In other words, in order to eliminate variations in the stop position, it is necessary to improve the parts accuracy and assembly accuracy of the printer, and in order to cope with changes in the status of the printer, It is necessary to take mechanical measures. However, individual differences in the stop position of the driven body can be eliminated without such accuracy improvement and mechanical measures. As a result, the cost of the printer can be reduced by the amount required for parts accuracy, assembly accuracy, and mechanical measures.

  Hereinafter, an embodiment of a printer according to 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 installation surface 1 side where the printer 10 is installed, and the upper side refers to the side away from the installation surface 1. A direction in which a carriage 30 described later moves is a main scanning direction, and a direction perpendicular to the main scanning direction and a direction in which the print target 12 is conveyed is a sub-scanning direction. Further, the side on which the printing object 12 is supplied will be described as a paper feeding side (rear end side), and the side on which the printing object 12 is discharged will be described as a paper discharge side (front side).

  The printer 10 includes a chassis 11 that contacts the installation surface 1, and various units are mounted on the chassis 11. The various units include a carriage mechanism 20 that reciprocates the carriage 30 in the main scanning direction by a carriage motor (CR motor 25), and a paper conveyance mechanism that conveys the print object 12 by a PF motor 45 (corresponding to a motor and a paper feed motor). For example, there is a control unit 70 shown in FIGS. 2 and 7.

  Here, the carriage mechanism 20 will be described. As shown in FIGS. 1 and 2, the carriage mechanism 20 includes a carriage 30 corresponding to the driven body. The carriage mechanism 20 is disposed on the back side of a support frame 21, a carriage shaft 24 that is supported by the support frame 21, and slidably holds the carriage 30, and a shielding plate portion 22 described later. Carriage motor (CR motor 25), a gear pulley 26 attached to the CR motor 25, an endless belt 27, and a driven pulley 28 that stretches the endless belt 27 between the gear pulley 26. , A code plate 36 and a linear encoder 37 are provided.

  As shown in FIG. 1, the support frame 21 includes a shielding plate portion 22 and side plate portions 23 that are bent toward the paper discharge side at both ends of the shielding plate portion 22. A pair of side plate portions 23 support a carriage shaft 24 that guides the slide of the carriage 30 along the length of the chassis 11. A CR motor 25 for driving the gear pulley 26 is provided on the back side of the shielding plate portion 22.

  The CR motor 25 is a DC motor capable of PWM control, and adjusts the average voltage applied to the DC motor by adjusting the width (Duty ratio) of the pulse voltage to control the drive of the DC motor. It is possible. In such PWM control, there are a method using a uniform pulse having a uniform pulse width and a method using a non-uniform pulse in which the pulse width changes. Any pulse signal may be used. Further, any pulse signal may be used by various combinations of adjusting the duty ratio of the voltage pulse and the period of the voltage pulse. Note that a PF motor 45 to be described later is also a DC motor capable of PWM control.

  Here, a schematic configuration of the CR motor 25 is shown in FIG. As shown in this figure, the CR motor 25 includes a rotor 25a and a stator 25b (the hatched side is the stator 25b side in FIG. 3), and the rotor 25a has a coil for generating a magnetic field. Many 25d are wound. Further, a commutator 25e is attached to the rotor 25a, and therefore the commutator 25e rotates together with the rotor 25a. A plurality of commutators 25e are arranged in the circumferential direction (odd number; five in the present embodiment) while being spaced apart from the rotating shaft 25f by a predetermined diameter and having a predetermined gap.

  Further, the brush 25g is fixedly attached to a bottom cover (not shown) disposed on the opposite side of the CR motor 25 from the side on which the rotary shaft 25f protrudes to the outside. There are two brushes 25g, a plus side and a minus side, and they are provided at positions that are symmetrical with respect to each other in the radial direction with the above-described rotation shaft 25f interposed therebetween. The stator 25b is configured by attaching a permanent magnet 25h to a cylindrical outer case 25i.

  Further, as shown in FIG. 4 and the like, a carriage 30 is provided to face the platen 56. As shown in FIG. 1, the carriage 30 stores K (black), LM (light magenta), LC (light cyan), cyan (C), magenta (M), and yellow (Y) inks. For example, six cartridges 31 are detachably mounted. The cartridges 31 to be mounted are not limited to six colors, and may have any number of colors such as four colors, seven colors, and eight colors. The ink filled in the cartridge 31 is not limited to dye-based ink, and other types of ink such as pigment-based ink may be mounted.

  As shown in FIG. 4 and the like, a print head 32 is provided below the carriage 30. In the print head 32, nozzles (not shown) are arranged in a line in the transport direction of the printing object 12 to form nozzle lines corresponding to the respective color inks. In this embodiment, the nozzle row is composed of, for example, 180 nozzles, of which the 180th nozzle is located on the paper feed side and the first nozzle is located on the paper discharge side.

  In addition, a piezo element (not shown) that is one of the electrostrictive elements and has excellent responsiveness is arranged for each nozzle in the nozzle row provided under the carriage 30 and associated with each ink. Yes. The piezo element is installed at a position in contact with the wall surface that forms the ink passage, and the wall surface is pushed by the operation of the piezo element, and ink droplets can be ejected from the nozzles at the end of the ink passage. It has become.

  The print head 32 is not limited to the piezo driving method using a piezo element, and other methods may be used. Other methods include, for example, a heater method in which ink is heated with a heater and the generated foam force is used, a magnetostriction method in which a magnetostrictive element is used, an electrostatic method in which electrostatic force is used, and a mist method in which mist is controlled by an electric field. Etc. are mentioned as main methods.

  As shown in FIG. 2 and the like, the carriage mechanism 20 is provided with a code plate 36 and a linear encoder 37. The code plate 36 is attached to the surface of the shielding plate portion 22 that faces the carriage 30. In the code plate 36, slits are formed at predetermined intervals. As the predetermined interval, for example, there is a configuration in which a slit is provided every 1/180 inch. However, the interval between the slits is not limited to this, and can be variously changed. The code plate 36 and the linear encoder 37 function as a part of the measuring means. The linear encoder 37 corresponds to an encoder.

  A linear encoder 37 is attached to the back side of the carriage 30 facing the code plate 36. As shown in FIG. 5, the linear encoder 37 includes a light emitting diode 37a, a collimator lens 37b, and a detection processing unit 37c. Among these, the detection processing unit 37c includes a plurality of (for example, four) photodiodes 37d, and further includes a signal processing circuit 37e and two comparators 37f and 37g.

  Here, when a predetermined voltage Vcc is applied to both ends of the light emitting diode 37a via a resistor, light is emitted from the light emitting diode 37a. This light enters the collimator lens 37b, and the light emitted from the collimator lens 37b is shaped into parallel light. Then, the parallel light passes through the code plate 36, and passes through the above-described slit during this passage. After passing through the slit, the parallel light is incident on the four photodiodes 37d and converted into electric signals.

  Then, the electrical signals output from the four photodiodes 37d are processed in the signal processing circuit 37e, and output signals to the comparators 37f and 37g. The comparators 37f and 37g compare these signals, and compare the comparison results as pulses (pulse ENC-A, pulse ENC-B). Here, the output pulses ENC-A and ENC-B are different in phase from each other by 90 degrees. Therefore, when the CR motor 25 is in the forward rotation state (when the carriage 30 is moving away from the home position), the phase of the pulse ENC-A advances by 90 degrees relative to the pulse ENC-B. When the CR motor 25 is in the reverse rotation state, the phase of the pulse ENC-A is delayed by 90 degrees with respect to the pulse ENC-B.

  One period T of the pulses ENC-A and ENC-B corresponds to the slit interval of the code plate 36, and is equal to the time during which the carriage 30 moves through each slit.

  Details of the paper transport mechanism 40 will be described with reference to FIG. The paper transport mechanism 40 shown in FIG. 4 includes a paper feed roller 41, a hopper 42, and a separation pad 43.

  The paper feed roller 41 that is rotationally driven by the PF motor 45 shown in FIGS. 1 and 2 has a roller body 41a and a rubber material 41b wound around the outer periphery of the roller body 41a. Further, the side view of the paper feed roller 41 is substantially D-shaped. Of the paper feed roller 41, the arc portion of the rubber material 41b feeds a relatively thin sheet of the print target 12, and the paper passes through the flat portion of the rubber material 41b so that the paper on the paper discharge side A transport load is not applied during the transport operation by the discharge roller pair 60.

  The hopper 42 is composed of a plate-like body on which the paper can be placed, and is provided in an inclined posture as illustrated. Further, the hopper 42 is provided so as to be swingable around a rotation shaft 42a provided at the upper part. Then, the lower end portion is elastically pressed against or separated from the paper feed roller 41 by swinging by a cam mechanism (not shown). Accordingly, when the hopper 42 swings in the press-contact direction with respect to the paper feed roller 41, the bundle of sheets accumulated on the hopper 42 comes into pressure contact with the paper feed roller 41. When the paper feed roller 41 rotates in such a pressure contact state, the uppermost one of the stacked sheets is sent to the paper discharge side.

  The separation pad 43 is made of a member having a high friction coefficient, and is provided at a position facing the paper feed roller 41. When the paper feed roller 41 rotates, the arc portion of the rubber material 41b and the separation pad 43 are pressed against each other. The uppermost sheet sent by the rotation of the paper feed roller 41 passes through this pressure contact portion and proceeds to the paper discharge side. Subsequent sheets are prevented from proceeding to the paper discharge side due to the presence of such pressure contact portions. Thereby, double feeding of paper is prevented.

  Note that the paper transport mechanism 40 may employ a system having a retard roller in addition to the system having the separation pad 43. When the retard roller is provided, the print object 12 can be sent in a state where the leading end of the print object 12 is not turned up due to the rotation / stop between the feed roller 41 and the retard roller.

  A paper guide 44 made of a plate-like body is provided substantially horizontally on the paper discharge side of the paper transport mechanism 40. The leading edge of the paper fed by the paper feed roller 41 is in contact with the paper guide 44 obliquely and is smoothly guided to the paper discharge side. Further, a PF roller pair 50 including a PF drive roller 51 and a PF driven roller 52 is provided on the paper discharge side with respect to the paper guide 44. Here, the PF driven roller 52 always receives a biasing force toward the PF drive roller 51 by the action of a biasing force (elastic force) of a spring 54 described later.

  For this reason, the print object 12 conveyed through the hopper 42 side or through an opening 57 described later is between the PF drive roller 51 and the PF driven roller 52 with respect to the print object 12. Nipping while applying urging force. Further, the PF driving roller 51 is rotated by the driving force transmitted from the PF motor 45 shown in FIGS. 1 and 2. Therefore, when the PF motor 45 is operated for one step at a constant pitch, the print object 12 sandwiched between the PF roller pair 50 is conveyed to the paper discharge side for the one step.

  The PF driven roller 52 is pivotally supported on the paper discharge side of the driven roller holder 53. The driven roller holder 53 is provided so as to be rotatable about a rotation shaft 53a. The driven roller holder 53 is urged to rotate in a direction (counterclockwise in FIG. 4) in which the PF driven roller 52 is always in pressure contact with the PF drive roller 51 by a spring 54 as an elastic member. The spring 54 is a torsion coil spring, and is inserted through the rotation shaft 53a.

  On the other hand, the surface of the PF driven roller 52 that comes into contact with the PF drive roller 51 is made of a member (not shown) having a lower friction than the above-described grip body 51b, and the low friction member is made of metal or the like. It is provided so as to cover the outer peripheral surface of the shaft body 51a.

  Also, a paper detector that detects the passage of the printing object 12 in the vicinity of the driven roller holder 53 located on the 0 digit side (the front side of the paper surface in FIG. 4; the reverse side of FIG. 4 is the 80 digit side). 55 is provided. The paper detector 55 includes a sensor body 55b and a detection lever 55a. Among these, the detection lever 55a has a substantially "<" shape on the side surface, and is provided so as to be rotatable about a rotation shaft 55c near the center thereof. The sensor body 55b is located above the detection lever 55a, and includes a light emitting part (not shown) and a light receiving part (not shown) that receives light from the light emitting part. The upper side of the rotation shaft 55c of the detection lever 55a is configured to block and pass light from the light emitting unit to the light receiving unit by the rotation operation.

  Therefore, as shown in FIG. 4, when the detection lever 55a is rotated upward as the print target 12 passes, the upper side of the detection lever 55a is disengaged from the sensor body 55b. As a result, the light receiving unit is in a light receiving state, and the passage of the front end of the printing object 12 is detected. Further, when the rear end of the printing object 12 passes the detection lever 55a, the detection lever 55a rotates in a direction to return downward. Thereby, the light receiving unit is switched to the non-light receiving state, and the passage of the rear end of the print object 12 is detected.

  Further, on the paper discharge side of the PF drive roller 51, the platen 56 and the above-described print head 32 are disposed so as to face each other in the vertical direction. The platen 56 corresponds to the guide member, and supports the printing object 12 conveyed below the print head 32 by the discharge roller pair 60 from below.

  Here, a side sectional view of the platen 56 is shown in FIG. As shown in FIG. 6, ribs 57 a, 57 b, 57 c (corresponding to sliding portions) protrude from the platen 56 upward from the reference plane 56 a of the platen 56. These ribs 57a, 57b, and 57c are provided continuously in the sub-scanning direction, so that the print object 12 can be conveyed satisfactorily.

  The ribs 57a are intermittently provided in the main scanning direction with a certain distance from the other ribs 57a, and the reference plane 56a described above exists between the adjacent ribs 57a and 57a. is doing. However, it is necessary for the platen 56 to correspond to borderless printing in which printing is performed up to the edge of the specified print object 12. For this reason, a portion of the reference plane 56a where the edge of the prescribed print object 12 approaches is provided with a recess (not shown) that is recessed in the downward direction along the sub-scanning direction. . Further, there are recesses 58a and 58b (corresponding to non-sliding portions) extending in the main scanning direction between the ribs 57a and 57b and between the ribs 57b and 57c.

  Further, a paper discharge roller pair 60 similar to the above-described PF roller pair 50 is provided on the paper discharge side of the platen 56. The paper discharge roller pair 60 includes a paper discharge driving roller 61 and a paper discharge driven roller 62. The discharge driving roller 61 is rotated by the driving force transmitted from the PF motor 45. Further, a biasing force is applied to the paper discharge driven roller 62 by the spring 63 in a direction in which the paper discharge driven roller 62 is always pressed against the paper discharge driving roller 61.

  The print object 12 is nipped (nip) by the paper discharge roller pair 60 while being given a predetermined urging force. In this state, when the paper discharge driving roller 61 rotates, the paper is discharged leftward in FIG. The paper discharge drive roller 61 employs a configuration in which rubber rollers are intermittently arranged in the width direction on a shaft body extending in the width direction of the print target 12. The PF motor 45 described above adopts a configuration in which the driving force is distributed to the PF driving roller 51 and the paper discharge driving roller 61. However, a configuration may be employed in which a separate motor is provided in addition to the PF motor 45 and the discharge driving roller 61 is driven by the motor.

  An opening 57 is provided below the hopper 42 described above. The opening 57 is an opening on the rear end side of the printer 10 and has a width in the main scanning direction sufficient to allow the print target 12 to pass therethrough. An example of the printing object 12 that passes through the opening 57 is a thick photo stand paper.

  Next, the configuration of the control unit 70 will be described with reference to FIG. The control unit 70 includes a bus 70a, a CPU 71, a ROM 72, a RAM 73, a character generator (CG) 74, an ASIC 75, a DC unit 76, a PF motor driver 77, a CR motor driver 78, a head driver 79, a nonvolatile memory 80, and the like. . Note that, in the control unit 70, the DC unit 76 functions as a part of the measurement unit and as a motor control unit alone or in cooperation with another configuration.

  Further, the CPU 71 and the DC unit 76 include the paper detector 55 described above, a PW sensor (not shown) for detecting the paper width, a rotary encoder 81 (described later), a linear encoder (not shown) for detecting the movement amount of the carriage 30, and the printer 10. Each output signal of the power source SW for turning on / off the power source is input.

  The CPU 71 performs arithmetic processing for executing the control program for the printer 10 stored in the ROM 72, the nonvolatile memory 80, and the like, and other necessary arithmetic processing.

  The ROM 72 stores a control program for controlling the printer 10 and data necessary for processing. In the present embodiment, the ROM 72 stores a drive control program, a correction table related to a correction value X, which will be described later, and the like corresponding to the type of the printing object 12. This drive control program enables the control drive of the CR motor 25 based on the detection of the linear encoder 37 corresponding to the flowchart shown in FIG. Further, the ASIC 75 has a built-in parallel interface circuit, and can receive a print signal supplied from the computer 90 via the interface 91.

  The RAM 73 is a memory that temporarily stores a program being executed by the CPU 71 or data being calculated. The nonvolatile memory 80 is a memory for storing various data that needs to be retained even after the inkjet printer 10 is turned off. The nonvolatile memory 80 stores a correction table related to a correction value X, which will be described later, and corresponds to a storage unit.

  The rotary encoder 81 is different from the linear encoder 37 described above in that the code plate is provided in a disc shape. However, the other configuration is the same as that of the linear encoder 37. In the present embodiment, the slit interval of the plurality of slits provided on the code plate of the rotary encoder 81 is 1/180 inch, and when the PF motor 45 rotates by one slit, The print object 12 is configured to be conveyed by 1440 inches. However, the slit interval and the conveyance pitch are not limited to this, and can be variously set.

  The DC unit 76 is a control circuit for performing speed control of the CR motor 25 and the PF motor 45 which are DC motors. The DC unit 76 performs various speed controls for the PF motor 45 and the CR motor 25 based on a control command sent from the CPU 71, an output signal of a rotary encoder 81 described later, and an output signal of the paper detector 55. Calculation is performed, and a motor control signal (analog current, corresponding to motor drive information) is transmitted to the PF motor driver 77 and the CR motor driver 78 based on the calculation result.

  The DC unit 76 is a drive control portion for performing predetermined control (in this embodiment, PID control, control based on the correction processing unit 76n). Specifically, as shown in FIG. 8, the DC unit 76 includes a position calculator 76a, a subtractor 76b, a target speed calculator 76c, a speed calculator 76d, a subtractor 76e, a proportional element 76f, an integral An element 76g, a differential element 76h, an adder 76i, a D / A converter 76j, a timer 76k, an acceleration control unit 76m, and a correction processing unit 76n are provided.

  Among these, as shown in FIG. 9, the position calculation unit 76 a is configured to output each of the output pulses ENC-A (hereinafter referred to as pulse A) and ENC-B (hereinafter referred to as pulse B) of the linear encoder 37. The transport distance is calculated by detecting the rising and falling edges and counting the number of detected edges.

  In this counting, “+1” or “−1” is added every time one edge is detected, corresponding to forward rotation or reverse rotation of the CR motor 25. The period of each of pulse A and pulse B is equal to the slit interval of the code plate, and pulse A and pulse B have a phase difference of 90 degrees. Therefore, “1” in the above-described counting corresponds to ¼ of the slit interval of the code plate of the encoder 37. When the CR motor 25 rotates by an amount corresponding to one slit interval, the carriage 30 moves by 1/180 inch. In this case, the resolution of the encoder 37 is 1/4 × 1/180, so / 720 inch.

  The speed detection of the carriage 30 based on the pulses ENC-A and ENC-B is performed as follows. First, a rising edge or a falling edge is detected for the pulse ENC-A / pulse ENC-B. At the same time, the time interval between the edges of the pulse ENC-A / pulse ENC-B is counted by the timer 76k, and the period T of the pulse ENC-A / pulse ENC-B is obtained from the count. If the slit interval of the code plate 36 is λ, the speed of the carriage 30 is λ / T, which is obtained for each period.

  The calculation of the speed of the carriage 30 is not limited to this. For example, by detecting the rising edge of the pulse ENC-A and the falling edge of the pulse ENC-B, by detecting a quarter of the period T, It may be calculated.

  The subtractor 76b calculates a position deviation between the target position and the count value of the position calculation unit 76a. Further, the target speed calculation unit 76c calculates the target speed of the CR motor 25 based on the position deviation calculated by the subtractor 76b. In this case, the target speed is calculated by multiplying the position deviation by the gain Kp. The gain Kp is set to a value that can appropriately reduce the position deviation.

  Further, the speed calculator 76 d calculates the actual driving speed of the CR motor 25 based on the output pulses A and B of the linear encoder 37. In this case, the rising and falling edges of each of the output pulses A and B of the linear encoder 37 are obtained, and the time interval between the edges is counted by, for example, the timer 76k. The subtractor 76e calculates the speed deviation by taking the difference between the target speed and the actual driving speed.

  Further, the proportional element 76f multiplies the calculated speed deviation by a predetermined constant Gp and outputs the result. The path passing through the proportional element 76f corresponds to the P control function in the PID control. Further, the integration element 76g integrates a predetermined constant Gi to the speed deviation and outputs the result. The path passing through the integration element 76g corresponds to the I control function in PID control. The differential element 76h multiplies the difference between the current speed deviation and the previous speed deviation by a predetermined constant Gd, and outputs the result. The path passing through the differential element 76h corresponds to the D control function in PID control. The calculation of the proportional element 76f, the integral element 76g, and the derivative element 76h is performed every period of the output pulse A of the encoder 37, for example, in synchronization with the rising edge of the pulse A.

  The outputs from the proportional element 76f, the integral element 76g, and the derivative element 76h are added by an adder 76i. After the addition, the analog current is output to the D / A converter 76j, an analog current is output from the D / A converter 76j to the CR motor driver 78, and the CR motor 25 is controlled by the CR motor based on the analog current. It is driven by a driver 78. In addition, a timer 76k that generates a timer interrupt signal and an acceleration control unit 76m that integrates a predetermined current value based on the timer interrupt signal are provided. These include a proportional element 76f, an integral element 76g, and a derivative element 76h. Used for acceleration / deceleration control in the used PID control.

  The output from the correction processing unit 76n is added by the adder 76p. The correction processing unit 76n calculates a correction value Y and a correction amount Z, which will be described later. The correction value Y is information for eliminating the carriage 30 stop error that occurs in response to the latest situation change (environment change) since the printer 10 is turned on. The correction value Y corresponds to the latest correction information. Details of these will be described later.

  Further, the CR motor driver 78 includes, for example, a bridge circuit in which a plurality of transistors are arranged. Based on the output of the D / A converter 76j, each of the transistors is turned on or off, thereby operating mode (normal rotation). Switching between brake mode and stop mode is possible. The CR motor driver 78 outputs an appropriate pulse voltage subjected to PWM control to the CR motor 25. Thereby, the CR motor 25 is driven and controlled. The PF motor driver 77 also controls and drives the PF motor 45 based on the motor control signal from the DC unit 76, similarly to the CR motor 25. The head driver 79 controls and drives the piezo elements existing in the print head 32 based on a signal for performing drive control from the CPU 71.

  Each component in the control unit 70 is connected by a bus 70a which is a signal line. By such a bus 70a, the CPU 71, ROM 72, RAM 73, CG 74, ASIC 75, nonvolatile memory 80, etc. are connected to each other, and data can be exchanged between them.

  The analog current output from the D / A converter 76j via the CR motor driver 78 corresponds to PWM control that adjusts the duty ratio of the voltage. An analog current corresponding to the duty ratio adjustment of the voltage is applied to the CR motor 25.

  The printer 10 includes an interface 91. A computer 90 is connected via the interface 91.

  Details of control when the printer 10 is operated using the above configuration will be described based on the control flow of FIG.

  First, the user turns on the power SW of the printer 10 (step S10). Then, the printer 10 reads the correction value X (corresponding to the stop tendency correction information) corresponding to the type of the printing object 12 from the correction table stored in the nonvolatile memory 80 (step S11; Corresponding to the reading process). Here, the correction value X is a correction value for making the center position of the variation of the stop position coincide with the original target stop position from the initial stage when the printer 10 is manufactured. That is, the printer 10 may tend to stop at a position that has exceeded a predetermined stop position from the initial stage of manufacture, and conversely, at a position on the near side. When such a tendency exists, the center position of the stop position variation stops with a predetermined amount of deviation from the target stop position. Therefore, a correction value X for eliminating such a shift amount and stopping the carriage 30 at the original target stop position is applied in advance to the duty ratio for driving the CR motor 25.

  Such variation generally occurs due to mechanical assembly in the transmission path when the driving force is transmitted from the CR motor 25 to the carriage 30, such as variations in counter electromotive force and coil resistance in the CR motor 25, component accuracy, and the like.

  Here, the correction value X is a value for changing the timing of voltage application applied to the CR motor 25 in the low speed region when the CR motor 25 stops. For example, when the carriage 30 has a tendency to stop at a position that is excessively a from the target stop position, the CR motor 25 is decelerated (see FIG. 11B) at a timing that is earlier by the time corresponding to the a. The start position of t5) is advanced. At this time, the Duty ratio is lowered earlier by the timing. The change to the duty ratio before correction at each timing corresponds to the correction value X. On the other hand, for example, when the carriage 30 has a tendency to stop at a position just before the target stop position by b, the deceleration start position of the CR motor 25 is delayed at a timing after a time corresponding to b. To. At this time, the duty ratio is lowered after being delayed by the timing. At this time, the duty ratio is lowered with a delay corresponding to the timing. Also in this case, the change to the duty ratio before correction at each timing corresponds to the correction value X.

また、補正値Ｘは、次の式によっても表される。

ここで、ｍi は、キャリッジ３０の停止位置と目標停止位置との間の、それぞれのずれ量（補正値Ｘ）であり、ｎは、キャリッジ３０が停止した回数（なお、これらのずれ量、補正値Ｘは、プリンタ１０が安定的な状態における値が好ましい。）であり、Ｋは、ずれ量ｍi と補正値Ｘとの間の所定の係数である。また、Ｘi は、それぞれのプリンタ１０の電源オンにおいて実際に用いられた補正値Ｘである。なお、プリンタ１０の電源オンの度ごとに補正値Ｘを算出する以外に、プリンタ１０の電源オンの間、所定時間毎に補正値Ｘを更新し、かかる更新された補正値ＸをDuty比に印加するようにしても良い。 The correction value X is desirably a deviation amount when the environmental conditions are the same. Therefore, for example, the correction amount after a predetermined time has elapsed after use, not immediately after use of the printer 10, may be used for calculation of the correction value X to be used after the next time. The correction value X is expressed by the following mathematical formula.

The correction value X is also expressed by the following formula.

Here, mi is a deviation amount (correction value X) between the stop position and the target stop position of the carriage 30, and n is the number of times the carriage 30 has stopped (note that these deviation amounts and corrections). The value X is preferably a value when the printer 10 is stable.), And K is a predetermined coefficient between the deviation amount mi and the correction value X. Xi is a correction value X actually used when the power of each printer 10 is turned on. In addition to calculating the correction value X every time the printer 10 is turned on, the correction value X is updated every predetermined time while the printer 10 is turned on, and the updated correction value X is set to the duty ratio. You may make it apply.

  Then, the CR motor 25 is driven in a state where the correction value X is read and applied to the duty ratio (step S12; corresponding to the first correction process and the initial driving process). In this drive, acceleration control and PID control are sequentially performed, further stop control is performed, and drive stop is performed. At this time, it is determined whether or not the carriage 30 has stopped near the target stop position (step S13). . In this series of control of the CR motor 25, voltage control is performed so that the carriage 30 follows the target speed shown in FIG. Note that changes in the speed of the carriage 30 including acceleration control and stop control other than the above-described PID control are as shown in FIG.

  In the present embodiment, such control is performed by changing the duty ratio of the voltage. In other words, when the CR motor 25 is activated, when the CPU 71 transmits a signal corresponding to the control command to the DC unit 76, the initial value E0 of the duty ratio for activation is sent from the acceleration control unit 76m to the D / A converter 76j. The voltage sent and corresponding to the initial value E0 of the duty ratio is applied to the CR motor 25 via the D / A converter 76j and the CR motor driver 78. At this time, an analog current corresponding to the initial value of the Duty ratio flows through the CR motor 25, whereby the CR motor 25 is started.

  Further, in a region other than the startup of the CR motor 25, the speed of the CR motor 25 is controlled by appropriately controlling the voltage duty ratio. In the CR motor 25, acceleration control, PID control, and stop control are performed as speed control. Among these, in the stop control, the duty ratio of the voltage is reduced to a constant value Es so that the CR motor 25 stops at the target position due to the driving load of the CR motor 25.

  If it is determined in step S13 described above that the vehicle is stopped near the target stop position (in the case of Yes), then a deviation amount is calculated (step S14; corresponding to the measurement process). The shift amount is calculated by measuring the stop position of the carriage 30 using the code plate 36 and the linear encoder 37 and comparing the target stop position with the actual stop position.

  The target stop position is a predetermined position in advance depending on the size of the print object 12 and the like. Therefore, the deviation amount can be easily calculated based on the measurement positions of the code plate 36 and the linear encoder 37 at a predetermined time. In addition, due to the presence of a loop returning from step S20 to step S12, the amount of deviation is measured at each of both ends of the carriage 30 in the main scanning direction.

  Next, it is determined whether or not the calculated deviation amount is within an allowable range (step S15). In this step S15, when it is determined that it is not within the allowable range (in the case of No), it is subsequently determined whether or not the correction processing is the first time (step S16). This determination is performed to determine whether or not the correction value Y needs to be calculated since the correction value Y has not yet been calculated when the correction process is performed for the first time. On the contrary, when the correction processing is performed for the second time or more, the correction value Y has already been calculated. Therefore, when calculating the correction amount Z described later, the adjustment of the correction amount Z is performed by adjusting the coefficients a and b. This is because it can be done.

  In the above-described step S16, when the correction process is the first time (in the case of Yes), the correction value Y is calculated based on the deviation amount measured in the above-described step S14 (step S17; the latest correction information calculation step). Correspondence). The correction value Y is a correction value as long as the printer 10 is turned on when the printer 10 is turned on. For example, the load on the carriage 30 often changes significantly due to a sudden change in the temperature around the printer 10, solidification of ink, adhesion of dust, and the like. Therefore, the carriage 30 may stop at a position having a large amount of deviation from the target stop position. Considering such a case, after the power is turned on, the CR motor 25 is driven to calculate the shift amount and the correction value Y, and the correction value Y is reflected in the Duty ratio. In this way, it is possible to eliminate the deviation amount of the printer 10 with respect to the target stop position during the specific power-on.

  Here, the correction value Y is represented by the equation Y = Σl / k. In this equation, l is the amount of deviation detected by the linear encoder 37 or the like, and is the amount of deviation of the actual stop position of the carriage 30 from the target stop position as long as the power of the printer 10 is turned on. Further, Σl is the sum of the stop position deviations from the power-on of the printer 10. Further, k is the number of round trips since the power is turned on. For this reason, the correction value Y is an average with variation in the stop position immediately after the power is turned on.

  The correction value Y is a value that constantly fluctuates during use of the printer 10 due to heat generation in the printer 10, a decrease in the viscosity of the solidified ink, and the like. Therefore, step S19 described later is provided. That is, the correction amount Z can be finely adjusted by adjusting the coefficients a and b in step S19 while the carriage 30 is reciprocatingly driven by the CR motor 25. Further, in the operation immediately after the power is turned on, it is conceivable that the deviation amount of the stop position varies for each movement of the CR motor 25. Corresponding to such a case, the correction value Y may be applied from the point where the information regarding the deviation of the stop position from the power-on is added by the number of times that the operation is stabilized (reliable number of times). .

  Here, based on the correction value X and the correction value Y calculated as described above, the correction amount Z is set to the Duty ratio in the following control (control after control based only on the correction value X). This is applied to drive the CR motor 25 (step S18; corresponding to the second correction step). Here, the correction amount Z is a correction amount represented by a mathematical formula of Z = aX + bY. In this equation, the coefficient b is weighted more than the coefficient a. That is, in the correction amount Z, the influence of the shift amount in the latest environmental change such as ink solidification, adhesion of dust, change in the remaining ink amount, etc. is larger than the relatively small shift amount as a cumulative tendency. . That is, when the latest environmental change occurs, a large shift amount is likely to occur. Therefore, the coefficient b is adjusted so as to be weighted more than the coefficient a.

  An example of such weighting is when the coefficient b has a difference of about 100 times with respect to the coefficient a.

  Here, the driving correction of the CR motor 25 by applying the correction amount Z is performed by adjusting the timing at which the duty ratio of the voltage is reduced. However, the adjustment of the correction amount Z, which will be described later, may be performed by adjusting not only the timing for reducing the duty ratio of the voltage but also the duty ratio of the voltage.

  In step S16 described above, when the correction process is performed for the second time or more (in the case of No), subsequently, adjustment of coefficient a and coefficient b of correction amount Z = aX + bY described later is performed (step S19). Such adjustment is performed mainly by changing the coefficient b. That is, when a predetermined time elapses after the printer 10 is turned on, the situation surrounding the printer 10 changes due to heat generation of the printer 10 or the like. Since the change in the situation relates to the coefficient b, the adjustment of the correction amount Z is also performed by adjusting the coefficient b.

  Further, after step S18 and step S19 described above, it is determined whether or not the CR motor 25 is driven again (step S20). And when driving CR motor 25 again (in the case of Yes), in the state where correction amount Z of Step S18 or Step S19 was applied, it returns to Step S12 and repeats the above-mentioned flow.

  If it is determined in step S20 that the CR motor 25 is to be stopped (standby state) (in the case of No), it is next determined whether to turn off the printer 10 (step S21). If it is determined in this determination that the power is to be turned off (in the case of Yes), the correction amount Z is stored in the nonvolatile memory 80 prior to the power-off of the printer 10 (step S22). In this case, the correction amount Z is stored in the nonvolatile memory 80 as a new correction value X.

  The correction value X may be stored not only when the power is turned off, but also when it is determined that the environment of the printer 10 has become stable after a predetermined time has elapsed. The new correction value X stored in the nonvolatile memory 80 is used when the printer 10 is activated next time. That is, at the next power-on, the number of activations i is updated to i + 1, and the average of the correction values Xi + 1 including the new correction value X (corresponding to Xi + 1) is the correction value at the next activation. Let X be.

  As described above, the shift amount of the stop position of the carriage 30 is eliminated, and the carriage 30 can be stopped at the target stop position.

  Note that printing on the print object 12 is executed in parallel with the elimination of the shift amount. However, it is also possible to perform only the cancellation of the shift amount without executing the printing on the print object 12. In the above flow, since step S19 is provided, the correction amount Z is adjusted by adjusting the coefficients a and b in step S19. However, the correction amount Z may be adjusted by changing the correction value Y without adjusting the coefficients a and b.

  In addition, the determination of power-off in step S22 is not limited to the case where the CR motor 25 is in a standby state, and may be performed at any time as long as the printer 10 is powered on. In this case, separately from the above steps, it is determined whether or not the power is off. When it is determined that the power is off, the correction amount Z is stored in the nonvolatile memory 80 as the correction value X.

  According to the printer 10 and the drive control method configured as described above, the accuracy of the stop position in the initial stage of driving of the CR motor 25 can be improved by reflecting the correction value X in the Duty ratio. That is, the correction value X is information for correcting a deviation of the central position of the accumulated stop position variation from the beginning of manufacturing the printer 10 to the present. Then, if the correction value X is reflected in the Duty ratio, it is possible to eliminate the deviation of the center position due to the variation of the stop position. That is, the center position of the stop position variation can be matched with the target stop position.

  Therefore, it is possible to eliminate the habit of the stop position due to a mechanical cause for each printer 10, and it is possible to improve the probability of stopping the carriage 30 at the target stop position.

  In addition to the correction value X described above, the correction value Y is reflected in the Duty ratio. For this reason, for example, when there is a change in the situation surrounding the printer 10 such as a sudden change in the temperature around the printer 10, grease breakage in the drive transmission portion, ink solidification, dust adhesion to the drive portion, etc. Often, the load at 30 drives varies significantly. In this case, the carriage 30 may not stop at the target stop position even when the correction value X described above is reflected, but may stop at a position having a large deviation amount. However, as described above, after the power is turned on, the CR motor 25 is driven to calculate the deviation amount and the correction value Y, and the correction value Y is reflected in the Duty ratio. The amount of deviation with respect to the target stop position can be eliminated. Thereby, the accuracy of the actual stop position with respect to the target stop position of the carriage 30 can be improved, and even when the printing is continued during the stop control, it is possible to prevent the printing from being shifted. For this reason, it is possible to improve the printing quality.

  In addition, by performing each correction as described above, it is possible to widen the range of selection of components constituting the printer 10. That is, in order to eliminate the variation in the stop position from the beginning of manufacture of the printer 10, it is necessary to improve the component accuracy and assembly accuracy of the printer 10, and it is not possible to select a component that does not reach a certain processing accuracy. There is a problem. Further, in order to cope with a change in the status of the printer 10, it is necessary to take various mechanical measures in consideration of the change in the status.

  However, if the present invention is applied, it is possible to use parts that do not reach machining accuracy with a constant accuracy, and it is possible to eliminate individual differences in the stop position of the carriage 30 without using mechanical measures. It becomes possible. As a result, the cost of the printer 10 can be reduced by the amount required for parts accuracy, assembly accuracy, and mechanical measures. In addition, by applying the present invention, the stop position error can be eliminated by applying the correction amount Z, so that the load design of the printer 10 does not become severe, and the design freedom can be expanded.

  In the above-described embodiment, the correction amount Z is applied at the stop positions at both ends of the reciprocating movement of the carriage 30. Therefore, the accuracy of the stop position of the carriage 30 can be improved at both end portions of the reciprocating motion, and the print quality can be further improved.

  Further, in the above-described embodiment, only the correction value X is reflected in the Duty ratio at the initial stage of driving of the CR motor 25, and when the correction value Y is calculated after the initial driving, the correction value X is calculated. In addition, the correction amount Z, which is weighted toward the correction value Y, is reflected in the Duty ratio. Here, in the printer 10, the influence of the current status change of the printer 10 is more likely to occur than the influence of the deviation of the central position of the cumulative stop position variation. Therefore, by applying the correction amount Z in a state where the correction value Y is weighted more than the correction value X, the current status change of the printer 10 can be strongly reflected, and thus the stop position of the carriage 30. The accuracy can be improved.

  In the present embodiment, the coefficients a and b are changed every time the carriage 30 stops. Accordingly, it is possible to cope with a change in the status of the printer 10 such as a change in temperature, a change in ink viscosity, a change in ink weight, etc., which occurs as the time since the printer 10 is turned on. That is, at the initial stage of power-on of the printer 10, the driving load of the printer 10 is large due to, for example, the low ambient temperature and the ink solidified. The situation surrounding the printer 10 also changes due to the decrease in ink viscosity due to the heat generation and the ink discharge. For this reason, if the coefficients a and b are changed in accordance with the change in the situation, even if the time since the printer 10 is turned on becomes longer, the improvement of the stop position accuracy of the carriage 30 is ensured while the printer 10 is turned on. can do.

  Further, in the present embodiment, the stop position of the carriage 30 is measured using the code plate 36 and the linear encoder 37 provided in the printer 10. Therefore, it is possible to accurately measure the stop position of the carriage 30, and it is not necessary to provide a dedicated measuring device, and it is possible to suppress an increase in cost.

  In the present embodiment, the timing at which the duty ratio of the voltage applied to the CR motor 25 is reduced by applying the correction amount Z is adjusted. In this manner, the stop position of the carriage 30 can be easily changed. The CR motor 25 is controlled and driven by PWM control. In addition, the correction amount Z changes the duty ratio in this PWM control. For this reason, voltage control of the CR motor 25 can be performed easily and accurately. In addition, by performing PWM control, it is possible to increase the power efficiency.

  The position embodiment of the present invention has been described above, but the present invention can be variously modified. This will be described below.

  In the above-described embodiment, the case where the CR motor 25 is driven and controlled by PWM control has been described. However, the drive control of the CR motor 25 is not necessarily limited to performing PWM control. For example, when a constant voltage value is applied without performing PWM control, the current value flowing through the CR motor 25 may be adjusted by appropriately adjusting the voltage value.

  In the above-described embodiment, PID control is performed on the CR motor 25. However, when the motor is a pump motor, for example, it is not necessary to use PID control, and other control methods such as PI control and control based on a predetermined sequence may be used.

  Further, the motor for performing the control for applying the correction amount Z is not limited to the CR motor 25, and the same control may be performed for the PF motor 45 as well. Further, the same control may be performed on the pump motor in the pump unit and the motor for adjusting the platen gap, which are included in the printer 10 and perform the ink suction operation.

  In the above-described embodiment, the case where the carriage 30 is used as the driven body has been described. However, the driven body is not limited to the carriage 30. For example, when the motor is a PF motor, the driven body is the print object 12 driven by the PF drive roller 51 or the like.

  Furthermore, in the above-described embodiment, the correction using the correction value X and the correction using the correction value Y are performed simultaneously while providing a difference in weighting between the two. However, only correction based on either the correction value X or the correction value Y may be performed. In these cases, it can be considered that one of the coefficients a and b is 0 in the correction amount Z = aX + bY. If it can be determined that the correction by the correction value X and the actual stop position are far from each other, the term X is almost unnecessary, so the coefficient a may be reduced. In this case, it is preferable to adjust by setting a + b = 1. Further, the correction may be performed by applying the correction amount Z obtained by the correction amount Z = X + Y to the Duty ratio without providing a difference between the weights of the two.

1 is a perspective view illustrating a configuration of a printer according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of a printer. It is a plane sectional view showing a schematic structure of a CR motor. FIG. 6 is a side sectional view of a portion related to paper feeding of the printer. It is a schematic diagram which shows the structure of a linear encoder. It is a sectional side view showing the shape near a platen. It is a block diagram of the control part which performs various control of a printer. It is a block diagram which shows schematic structure of DC unit. It is a figure which shows the output pulse of an encoder. It is a flowchart which shows stop position correction | amendment in CR motor. It is a figure which shows the standard speed change when a carriage moves.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Printer, 12 ... Print object, 20 ... Carriage mechanism, 25 ... CR motor, 27 ... Belt, 30 ... Carriage, 31 ... Cartridge, 32 ... Print head, 33 ... Nozzle row, 33a ... Nozzle, 34 ... PW sensor , 36 ... code plate (part of measuring means), 37 ... linear encoder (part of measuring means), 40 ... paper transport mechanism, 45 ... PF motor, 50 ... PF roller pair, 70 ... control unit, 72 ... ROM, 76 ... DC unit (part of measuring means, corresponding to motor control means), 79 ... head driver, 80 ... nonvolatile memory (corresponding to storage means), 81 ... rotary encoder

Claims (11)

In a printer that performs printing on an object to be printed,
A motor,
A driven body driven by the motor;
Motor control means for giving drive information based on a control command to the motor and controlling the drive of the motor;
Measuring means for measuring the position of the driven body;
Stop tendency correction information for correcting a deviation amount between the center position of the cumulative stop position variation of the driven body from the past to the present and the target stop position of the driven body at the time of the stop. Storage means for storing;
And having
The motor control means is
Correcting the drive information with stop tendency correction information stored in the storage means, and controlling and driving the motor based on the drive information on which the correction has been made,
A printer characterized by that. In a printer that performs printing on an object to be printed,
A motor,
A driven body driven by the motor;
Motor control means for giving drive information based on a control command to the motor and controlling driving of the motor;
Measuring means for measuring the position of the driven body;
And having
The motor control means is
After driving the motor, drive information based on a control command for stopping the motor is given, and after the driven body is stopped, an actual stop position and the above stop at the time of the stop based on a measurement result by the measuring means. The amount of deviation from the target stop position of the driven body is calculated, the latest correction information for eliminating the amount of deviation is calculated, the drive information is corrected with the latest correction information, and the correction is performed. Based on the drive information, the motor is controlled and driven.
A printer characterized by that. In a printer that performs printing on an object to be printed,
A motor,
A driven body driven by the motor;
Motor control means for giving drive information based on a control command to the motor and controlling the drive of the motor;
Measuring means for measuring the position of the driven body;
Stop tendency correction information for correcting a deviation amount between the center position of the cumulative stop position variation of the driven body from the past to the present and the target stop position of the driven body at the time of the stop. Storage means for storing;
And having
The motor control means is
The drive information is corrected by the stop tendency correction information stored in the storage means, and the motor is controlled and driven based on the corrected drive information.
After driving the motor, drive information based on a control command for stopping the motor is given, and after the driven body is stopped, an actual stop position and the above stop at the time of the stop based on a measurement result by the measuring means. The amount of deviation from the target stop position of the driven body is calculated, the latest correction information for eliminating the amount of deviation is calculated, the drive information is corrected with the latest correction information, and the correction is performed. Based on the drive information, the motor is controlled and driven.
A printer characterized by that.   4. The printer according to claim 1, wherein the driven body is a carriage on which a print head is mounted, and the motor is a carriage motor that moves the carriage. 5. .   The correction of the drive information based on the stop tendency correction information, the latest correction information, or both of the stop tendency correction information and the latest correction information is performed at stop positions existing at both ends of the reciprocation of the carriage. The printer according to claim 4. The motor control means includes
At the beginning of driving of the motor, while performing drive control of the motor based on the stop tendency correction information,
After the initial driving, the motor drive control is performed in a state where the latest correction information is weighted rather than the stop tendency correction information.
The printer according to claim 3.   The printer according to claim 6, wherein the latest correction information changes the weighting as the operation time of the motor elapses.   6. The printer according to claim 4, wherein the measuring unit includes an encoder for measuring the position of the carriage at each time.   The printer according to any one of claims 1 to 8, wherein the stop tendency correction information or the latest correction information is information for changing a timing of changing a voltage value applied to the motor.   The printer according to claim 9, wherein the motor is controlled and driven by PWM control, and the motor control means changes the voltage value by changing a duty ratio in the PWM control. In a drive control method for executing printing on a print object while moving a driven body by driving a motor,
The amount of deviation between the center position of the cumulative stop position variation from the past to the present stored in the storage means and the target stop position of the driven body at the time of the stop is corrected. A reading process of reading stop tendency correction information for
A first correction step of correcting the drive information by the stop tendency correction information;
An initial driving step of performing initial driving of the motor and stopping the driven body with respect to a target stop position based on the driving information corrected in the first correcting step;
A measuring step of measuring a deviation amount between the position where the driven body actually stops in the initial driving step and the target stop position using a measuring unit;
Based on the measurement result in the measurement step, the latest correction information calculation step for calculating the latest correction information for eliminating the deviation amount,
A second correction step of correcting the drive information by the latest correction information;
A drive control method comprising:

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