JP2006240026A - Recording apparatus and method for controlling recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a carriage from being broken and an ink delivering face of a recording head exposed on the bottom face of the carriage from being damaged by rapidly stopping driving of the carriage when such abnormalities as paper floating condition of a recording paper and a foreign substance accidentally entered in an apparatus coming into contact with the carriage, in an inkjet recording apparatus. <P>SOLUTION: When the carriage is driven, while calculation processing on driving command values on position and speed is performed, information on the position and the speed are acquired by utilizing encoder information carried on the carriage. They are fed back, to judge the driving condition of the carriage from the information of differences between the position or the speed command value and the present position and speed values of the carriage, and when the difference values exceed allowable values, driving of the carriage is stopped. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording apparatus and a recording control method, and more particularly, to carriage drive deceleration and stop control in an inkjet recording apparatus, for example.

  In a conventional serial printer, for example, a DC motor and its control device (hereinafter referred to as a motor driver) are used as a drive source for scanning a carriage on which a recording head according to a dot impact method, an ink jet method, or a thermal transfer method is mounted. Yes.

  A general serial printer has a configuration in which when recording data is received from an external computer or the like, motor rotation is started to drive the carriage, and recording is started when a certain speed is reached. When recording is performed using recording data for one scan of the carriage, the motor is stopped, and a recording medium such as recording paper is conveyed by a length corresponding to the width of the one scan. Further, if there is recording data, the above operation is repeated to continue recording.

  Here, the operation of the carriage drive motor (hereinafter referred to as the carriage motor) will be described in detail.

  First, when a recording start command is sent from the computer, the printer controller activates the carriage motor via the motor driver.

  FIG. 8 is a diagram showing a change in the carriage speed in one carriage scan.

As shown in FIG. 8, immediately after the carriage motor is started, the carriage is gradually accelerated so that noise and vibration do not occur (A: acceleration region). When the carriage reaches a predetermined target speed (v = v _c ), the process shifts to constant speed control, and the recording head is driven to perform recording (B: constant speed region). After the end of recording, the carriage speed is quickly reduced and stopped (C: deceleration area). In the constant speed region B and the deceleration region C, control is performed so that noise or the like does not occur due to a rapid speed change, and further, in the constant speed region B, recording accuracy is not disturbed.

  Such speed control of the carriage motor is generally performed by a servo system having a PID control loop, and finally is performed by changing a voltage applied to the motor or a duty of PWM.

  Here, an example of controlling the motor speed by controlling the PWM duty will be described.

  First, the speed error (Ve) is calculated by subtracting the moving speed of the controlled object (here, the carriage) or the rotational speed of the motor detected by the position and speed detecting mechanism such as an encoder from the externally designated speed. Next, an operation amount (here, PWM duty) is calculated according to the equation (1).

PWM = Kp × Ve + Ki × ∫Ve · dt + Kd × (dVe / dt) (1)
Here, Kp is a proportional control constant, Ki is an integral control constant, and Kd is a differential control constant. The speed of the carriage is controlled by changing the duty of the PWM applied to the motor driver according to the calculated value.

The carriage motor is controlled in consideration of the load on the mechanical system including the carriage, noise during driving, the period of ink ejected from the recording head, and the like when performing carriage driving control. Further, when driving the motor, focusing on the torque, the motor is driven with a driving torque having a predetermined margin with respect to the load of the mechanical system (Patent Document 1).
JP 2004-090267 A

  In recent years, there has been a growing need for serial printers to perform recording operations on a wide variety of recording media, and various recording media have actually existed.

  When performing a recording operation on such a medium, various problems to be solved arise due to the structure of the recording apparatus.

  A typical example is a problem called paper floating, which is a phenomenon in which the recording medium itself warps depending on the use environment of the apparatus and the storage state of the recording medium. Usually, the height from the surface of the recording medium to the recording head is designed to be 1 to 2 mm. Therefore, when a minute paper float occurs, there arises a problem that the recording medium comes into contact with the scanning recording head. When the amount of paper floating is large, the carriage may reciprocate while tearing the recording medium, which may damage not only the recording medium but also the nozzle surface of the recording head.

  The present invention has been made in view of the above conventional example, and provides a recording apparatus and a recording control method capable of instantaneously detecting an abnormality in carriage scanning and protecting the recording medium and the recording head from damage. It is an object.

  In order to achieve the above object, the recording apparatus of the present invention has the following configuration.

  That is, a recording apparatus that performs recording on a recording medium by reciprocating a carriage on which a recording head is mounted, and detects a position of a carriage driven by the driving means and a position and speed of the carriage driven by the driving means. Detection means, command means for commanding the position and speed of the carriage, comparison means for feeding back the position and speed of the carriage detected by the detection means and comparing with the command value commanded by the command means, Drive control means for controlling the drive means to stop the carriage according to the comparison result by the comparison means, and the drive control means is configured to detect the position and speed of the carriage detected by the comparison by the comparison means. When the difference between the detected value and the command value corresponding to the detected value is larger than a predetermined threshold value, And outputs an instruction to stop moving.

  Here, the detection means includes a scale disposed in a carriage movement direction, an encoder mounted on the carriage for reading the scale according to the movement of the carriage, and a position of the carriage based on an output signal from the encoder. Generation means for generating a signal and a speed signal are included.

  The drive means includes, for example, a carriage motor such as a DC motor and a motor driver that drives the carriage motor.

  Therefore, in this case, the drive control means may issue an instruction for stopping the drive of the carriage motor to the motor driver.

  Furthermore, the reciprocating movement of the carriage is divided into an acceleration movement section, a constant speed movement section, and a deceleration movement section. The drive control means detects in the acceleration movement section and the constant speed movement section. It is desirable to perform control of the driving means based on the carriage speed, and to control the driving means based on the detected carriage position in the deceleration movement section.

  Specifically, the feedback control based on the detection by the detection unit and the comparison by the comparison unit may be performed, for example, about every 2 milliseconds.

  The recording head is preferably an ink jet recording head that performs recording by discharging ink onto a recording medium.

  According to another aspect of the present invention, there is provided a recording control method for performing recording on a recording medium by reciprocating a carriage having a recording head mounted thereon by a driving unit, the position and speed of the carriage driven by the driving unit. A detection step for detecting the carriage, a command step for commanding the position and speed of the carriage, and a comparison step for feeding back the position and speed of the carriage detected in the detection step and comparing them with the command value commanded in the command step And a drive control step for controlling the drive means to stop the carriage in accordance with the comparison result in the comparison step. In the drive control step, the detected carriage position by the comparison in the comparison step If the difference between the speed and the command value corresponding to the detected value is larger than a predetermined threshold value, the drive A recording control method characterized by outputting a command to stop the drive of the stage.

  Therefore, according to the present invention, in the carriage drive control, for example, an abnormal state such as a recording medium such as a recording sheet coming into contact with the carriage is fed back to the detected carriage position and speed, and commands for these values are sent. Compared with the value, the carriage can be stopped based on the comparison result.

  Thereby, compared with the conventional carriage drive control by an electric circuit, for example, overcurrent detection by an overcurrent limiter, it is possible to detect and respond to a carriage operation abnormality at a higher speed. Therefore, even if a carriage operation abnormality occurs during the recording operation, damage or damage to the recording medium or the recording head can be minimized.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  In this specification, “recording” (sometimes referred to as “printing”) is not only for forming significant information such as characters and figures, but also for human beings visually perceived regardless of significance. Regardless of whether or not it has been manifested, it also represents a case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or the medium is processed.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  Furthermore, “ink” (sometimes referred to as “liquid”) is to be interpreted broadly in the same way as the definition of “recording (printing)” above. It represents a liquid that can be used for forming a pattern or the like, processing a recording medium, or processing an ink (for example, solidification or insolubilization of a colorant in ink applied to the recording medium).

  Furthermore, unless otherwise specified, the “nozzle” collectively refers to an ejection port or a liquid channel communicating with the ejection port and an element that generates energy used for ink ejection.

  FIG. 1 is an external perspective view showing a configuration of a recording apparatus equipped with a recording head for ejecting ink according to an ink jet system which is a typical embodiment of the present invention.

  In FIG. 1, a carriage 5 is mounted with a recording head 1 and reciprocates along a guide rail 4 in the directions of arrows A1 and A2. The recording head 1 may use thermal energy, or eject liquid droplets of recording liquid from ink ejection nozzles (hereinafter referred to as nozzles) using mechanical energy to form an image on a recording medium.

  Further, the recording head 1 has, for example, a plurality of head units composed of a plurality of recording element groups corresponding to different colors of ink. For example, a head unit used for discharging Y (yellow) ink, a head unit used for discharging M (magenta) ink, a head unit used for discharging C (cyan) ink, and Bk (black) And a head unit used to eject ink. These color inks are stored in the main tank 7 and supplied from the main tank 7 to the recording head 1 through the tube 9 and the joint 8. The ink supplied from the main tank 7 is stored in a sub tank (not shown), and is supplied to the recording head 1 through the sub tank.

  In this embodiment, the sub tank and the recording head 1 are integrated to form a head cartridge 6, and the head cartridge 6 is mounted on the carriage 5.

  Further, by transmitting the driving force of the carriage motor 11 to the carriage 5 by the timing belt 17, the carriage 5 is reciprocated along the guide shaft 3 and the guide rail 4 in the directions of arrows A 1 and A 2 (main scanning direction). During this carriage movement, the carriage position is detected by reading a linear scale 19 provided along the carriage movement direction by an encoder sensor 21 provided on the carriage 5. Then, recording on the recording medium is started by this reciprocation. At this time, the recording sheet S <b> 2 is supplied from the sheet supply unit 12, sandwiched between the conveyance roller 16 and the pinch roller 15, and conveyed to the platen 2.

  Next, when the printing for one carriage scan is completed in the main scanning direction, the carriage 5 is returned to a predetermined position (a fixed position before the recording is started, hereinafter referred to as a home position), and the linear motor 20 is driven by the carry motor 13. Then, the conveying roller 16 is driven, and for example, a recording medium such as the recording sheet S2 is conveyed by a predetermined amount in the sub-scanning direction (the arrow B direction in the figure). As shown in FIG. 1, the home position is provided with a head cap 10 and a recovery unit 14, and performs recovery processing of the recording head 1 intermittently as necessary.

  Thereafter, as described above, the timing belt 17 and the carriage motor 11 move the carriage 5 from the predetermined position in the main scanning direction in the directions of the arrows A1 and A2, thereby recording an image, characters, or the like on the recording medium. . Further, the recording medium is intermittently conveyed on the platen 2 in synchronization with the scanning of the recording head by the rotation of the conveying roller 16 while being sandwiched between the conveying roller 16 and the pinch roller 15.

  By repeating the above-described operation, when recording for one sheet of recording medium is completed, the recording medium is discharged and recording for one sheet is completed.

  FIG. 2 is a block diagram showing a control configuration of the recording apparatus shown in FIG.

  As shown in FIG. 2, the controller 600 includes an MPU 601, a program corresponding to a control sequence to be described later, a required table, a ROM 602 storing other fixed data, a control of the carriage motor 11, a control of the transport motor 13, and a recording. A special purpose integrated circuit (ASIC) 603 that generates a control signal for controlling the head 1, a RAM 604 provided with a development area for image data, a work area for executing a program, and the like, MPU 601, ASIC 603, and RAM 604 are mutually connected. A system bus 605 for transferring data, and an A / D converter 606 for inputting analog signals from the sensor group described below, A / D converting them, and supplying digital signals to the MPU 601 and the like.

  In FIG. 2, reference numeral 610 denotes a computer (or a reader for image reading, a digital camera, etc.) serving as a supply source of image data, and is collectively referred to as a host device. Image data, commands, status signals, and the like are transmitted and received between the host apparatus 610 and the recording apparatus 1 via an interface (I / F) 611.

  Reference numeral 620 denotes a switch group, which instructs to start a power switch 621, a print switch 622 for instructing the start of printing, and a process (recovery process) for maintaining the ink ejection performance of the recording head 1 in a good state. For example, a recovery switch 623 for receiving a command input from the operator. Reference numeral 630 denotes a sensor for detecting an apparatus state including a position sensor 631 such as a photocoupler for detecting a home position, a temperature sensor 632 provided at an appropriate position of the recording apparatus for detecting an environmental temperature, and the like. Is a group.

  Further, reference numeral 640 denotes a carriage motor driver for driving the carriage motor 11 for reciprocating scanning of the carriage 5 in the directions of arrows A1 and A2. Reference numeral 642 denotes a conveyance motor driver for driving the conveyance motor 13 for conveying the recording medium.

  The ASIC 603 transfers printing element (ejection heater) drive data (DATA) to the print head while directly accessing the storage area of the RAM 602 during print scan by the print head 1.

  Further, as the carriage 5 moves, the encoder sensor 21 provided in the carriage 5 outputs an encoder signal generated by reading the linear scale 19 to the encoder controller 644. The encoder controller 644 performs signal processing on the encoder signal, generates a carriage position signal and a carriage speed signal indicating the carriage position and the carriage speed, and outputs them to the MPU 601.

  Next, carriage movement control by carriage motor drive in the recording apparatus having the above-described configuration will be described with reference to FIGS. Here, it is assumed that the carriage motor 11 is a DC motor.

  3 to 4 are block diagrams showing a control configuration related to feedback control based on an encoder signal. Specifically, these configurations include a carriage movement detection mechanism such as a carriage drive mechanism and its drive control circuit, such as a motor driver 640, an encoder sensor 21, an encoder controller 644, an MPU 601, and an ASIC 603. FIG. 3 shows a known feedback control configuration, and FIG. 4 shows a feedback control configuration according to this embodiment.

  3 to 4, common constituent elements are given the same reference numerals, and constituent elements already described in FIGS. 1 to 2 are already assigned the same reference numerals.

  3 to 4, the encoder controller 644 includes a position detector 105 that detects the carriage position and a speed detector 106 that detects the carriage speed from the change in the carriage position. Also, the generated carriage position signal and carriage speed signal are transferred from the encoder controller 644 to the RAM 604 and the MPU 601 or ASIC 603.

  On the other hand, the MPU 601 and the ASIC 603 are functionally provided with a command value generator 101 for instructing a carriage speed, a PID compensator 102, a PWM controller 103, and a control constant calculator 109. In this embodiment, an abnormality detector 110 for detecting a carriage abnormality from the carriage speed signal and the commanded carriage speed is provided.

  Note that how these functions are shared by the MPU 601 and the ASIC 603 is determined depending on required performance, the price of the apparatus, and the like.

  In this embodiment, the scanning speed and position of the carriage 5 are recorded with slits at a recording scale density corresponding to a linear scale 19 (for example, 150 dots / inch (dpi) or 300 dpi) extending in the scanning direction of the carriage 5. And the encoder signal generated by reading the slit with the encoder sensor 21 mounted on the carriage 5.

  As is apparent from the configurations of FIGS. 3 to 4, according to the error between the carriage speed value and the command speed value indicated by the carriage speed signal that is a feedback signal generated based on the encoder signal from the encoder sensor 21. The movement of the carriage is controlled by feedback control for controlling the motor. Here, the command speed is a speed that should be originally achieved at the timing when the speed of the carriage is detected.

  Carriage control is classified into speed control for performing control while paying attention to speed and position control for performing control while paying attention to position.

  In the ink jet recording operation as in this embodiment, the recording is performed by ejecting ink from the recording head to the recording medium while scanning the recording head. Therefore, the carriage speed control or the position control is appropriately performed and the control is performed. It is necessary to accurately deposit ink droplets at desired positions on the recording medium by appropriately determining the ink ejection timing based on the above.

  Such ink ejection is often performed in a constant speed region and an acceleration region in carriage movement. Therefore, in the acceleration area and the constant speed area of the carriage, control focusing on the speed is performed so that the carriage moves following a predetermined command speed. In the deceleration region, the carriage movement is controlled by paying attention to the position so that the carriage can stop at a predetermined position.

  5 to 6 are diagrams showing temporal changes in the carriage speed and the carriage position detected based on the encoder signal. FIG. 5 shows a case where the carriage is operating normally, and FIG. 6 shows an abnormality in the operation of the carriage. This shows the case where this occurs.

  5 to 6, (a) shows the time change of the carriage speed, (b) shows the time change of the carriage position, and the solid line shows the speed command value output from the command value generator 100. The dotted line indicates the value detected based on the encoder signal (ENC) value output from the encoder sensor 21.

  When the carriage 5 is operating normally, control is performed according to the speed command value and position command value output from the command value generator 100. Then, the feedback control calculation is performed in the PID compensator 102 based on the encoder signal (ENC value) in the acceleration area, constant speed area, and deceleration area of the carriage as described in FIG.

  Here, PID compensation will be described. This is to compensate the control state, and P of PID is a proportional compensation component, and specifically means to perform gain compensation. Further, I of PID is an integral compensation component, and specifically means that phase delay compensation is performed. D of PID is a differential compensation component, and specifically means phase advance compensation. The characteristics of the drive system are compensated by optimizing the parameters of each component. Then, the gain value that is a parameter of each block in the PID compensator 102 is determined according to the speed commanded by the control constant calculator 109 and the driving state such as acceleration and deceleration.

  As can be seen from FIG. 5, when the carriage is operating normally, the measured value (value obtained from the encoder signal) with respect to the command value shows a good tracking characteristic, and the feedback control functions correctly. ing.

  On the other hand, when the operation of the carriage 5 is abnormal, the conventional feedback control configuration shown in FIG. 3 performs carriage drive according to the speed command value and position command value output from the command value generator 100, In the acceleration area, constant speed area, and deceleration area of the carriage, feedback control calculation is performed in the PID compensator 102 based on the encoder signal (ENC value). As can be seen from FIG. 6, it is obtained from the encoder signal (ENC value). The obtained value is greatly deviated from the command value, and cannot follow the speed command value and the position command value from the command value generator 100.

  In order to cope with such inconvenience, in this embodiment, as shown in FIG. 4, an abnormality detector 110 is provided between the command value generator 101 and the PID compensator 102 having a feedback control configuration. The abnormality detector 110 monitors the difference Δv between the command value from the command value generator 101 and the carriage speed obtained from the encoder signal at the time of driving the carriage, and compares this with a determination value (Er_v)). Determine if it has occurred.

  As a difference determination value for determining whether or not an abnormal state has occurred, it is necessary to set a value corresponding to the moving speed or the moving amount at the design stage of the apparatus. In this embodiment, there are determination values that can be used in common in the acceleration region, constant speed region, and deceleration region. In this embodiment, specifically, the determination value (Er_v) is a value corresponding to 50% of the command speed value. That is, when there is a fluctuation of ± 50% or more of the speed command value, it is determined that the state is abnormal.

  Similarly, the abnormality detector 110 checks the difference (ΔP) from the position command value for the position abnormality. In this embodiment, a value corresponding to 50% of the command position amount is used as the determination value (Er_p). For example, if the carriage is operating normally, if it is detected that the movement of the linear scale 19 for 100 slits is detected as a movement of 49 slits in the feedback loop per time, an abnormal state is assumed. To be judged.

  If an abnormal state is detected, the MPU 601 interrupts feedback control and instructs the carriage motor driver 640 that drives the carriage motor 11 to stop driving the carriage motor. In this case, since there is a possibility that the recording head 1 is in contact with the recording medium, a signal to stop the carriage motor 11 is sent to the carriage motor motor driver 640 instead of performing a deceleration control by providing a deceleration region. Is controlled to output.

  Next, detection of an abnormal state and carriage stop processing in carriage driving, which are characteristic parts of this embodiment, will be described.

  The abnormal operation state of the carriage described in this embodiment means that, when the carriage is driven, for example, a recording medium such as a recording sheet floats from the platen 2 due to its storage state, environmental conditions, etc. In this state, the carriage 5 is in contact with the driving carriage 5, and further, the recording paper is caught on the carriage 5, and the carriage 5 is moved.

  Conventionally, in order to detect such an abnormal state, it is common to detect an overcurrent state using a current limiter or the like in an electric circuit. However, when such an abnormal state occurs, it takes time to detect the overcurrent state, and the carriage moves during that time. For example, if it takes several tens of milliseconds to detect it, the carriage will move considerably during that time, and if it is assumed that the recording paper is torn and moved, the moving state can be detected instantaneously. Desired.

  Therefore, in this embodiment, in order to detect this abnormal state, the difference between the position or speed command value used for carriage drive feedback control and the carriage position or speed value is monitored using the above-described configuration. When a difference of a certain level or more occurs, the carriage or the recording head is prevented from being damaged by controlling the carriage to stop immediately.

  Specifically, in this embodiment, feedback control is performed based on carriage speed information obtained from the encoder sensor 21 every 2 milliseconds. For example, in the constant speed region, the speed value obtained from the encoder is within a previously determined range. In such a state, when the end of the paper floating from the platen 2 comes into contact with the carriage, the speed variation of the carriage becomes large, so that a value out of the above range is obtained from the encoder signal. Therefore, if the carriage speed value obtained by feedback control several times (for example, three times) is out of the predetermined range, it can be determined that there is an abnormality. In this case, an abnormal state can be detected in about 6 milliseconds (2 milliseconds × 3).

  The control configuration described above is incorporated in the procedure of the entire recording operation of the recording apparatus.

  FIG. 7 is a flowchart showing an outline of the recording operation described mainly on the carriage movement control.

  First, in step S1, when a recording start command is sent from the host apparatus 610 connected to the recording apparatus via the interface 610, the MPU 601 determines whether or not a carriage initialization process is necessary. The process proceeds to step S2, an initialization process is performed, and if unnecessary, the process proceeds to step S3.

  One of the initialization processes is a process for moving the carriage 5 to the home position. In this embodiment, the current position of the carriage is set to a value exceeding the maximum distance that the carriage can move, and the arrival position is set to, for example, “0”. After setting this arrival position, feedback control is performed to move the carriage 5. As a result, the carriage 5 moves to the recovery unit 14, but before reaching the set arrival position, the carriage 5 comes into contact with the side surface of the main body and is prevented from moving.

  Accordingly, the encoder sensor 21 detects that the carriage position does not change, and the MPU 601 recognizes that the carriage 5 is in a stopped state accordingly. When this stop state is recognized for a predetermined number of times of control timing, it is recognized that the carriage has contacted the side surface of the main body, and this position is set as the home position of the carriage 5. In this embodiment, the position of the home position is, for example, “100”, and after this setting, the position of the carriage is changed as needed based on detection signals detected by the encoder sensor 21 and the linear scale 19 as the carriage moves. Detected.

  In this way, when an initialization process such as power-on is necessary, the initialization process is performed.

  When recording is not performed, the recording head 1 mounted on the carriage 5 is covered with the cap 10 of the recovery unit 14, but in step S3, its capping state is checked. If it is determined that the recording head 1 is in the capping state, the process proceeds to step S4, a cap OPEN process for removing the cap 10 from the recording head 1 is performed, and the cap OPEN state is confirmed. . On the other hand, if it is determined that the cap 10 has already been removed from the recording head 1, the process proceeds to step S5.

  In step S5, it is checked whether or not the recording medium to be conveyed (here, a recording sheet) has the sheet at the recording position of the recording apparatus. If it is determined that there is no recording paper, the process proceeds to step S6, the transport motor 13 is driven to rotate the transport roller 16, and the recording paper is fed and transported to the recording start position. On the other hand, if it is determined that there is a recording sheet, the process proceeds to step S7.

  Next, in step S7, the MPU 601 sets a carriage arrival position corresponding to the print data transmitted from the host device 610, and further performs carriage movement while executing feedback control in step S8.

  In the carriage movement control in this embodiment, the feedback control is performed at a cycle of 2 milliseconds.

  When the carriage 5 reaches the recording start position after the carriage movement starts, a recording signal is transferred from the controller 600 to the recording head 1 mounted on the carriage 5, whereby ink is ejected from the ejection port of the recording head 1. Recording starts. Furthermore, while the carriage 5 is moved and moved to the set arrival position, ink is ejected from the recording head 1 and recording is continued.

  In step S9, it is checked whether or not the carriage 5 has reached the set position. If the carriage 5 has not yet reached the set position, the process returns to step S8 to continue the carriage movement while continuing the feedback control. If it is determined that the carriage 5 has reached the set arrival position, the recording of the recording head by one carriage scan is completed, the process proceeds to step S10, and the MPU 601 detects the paper according to the recording data. The arrival position to be reached is set, and the conveyance motor 13 is driven to start conveying the recording paper.

  In step S11, the recording sheet is conveyed based on the feedback control. Further, in step S12, it is checked whether or not the recording sheet has reached the set arrival position. Returning to S11, the conveyance of the recording paper is continued by feedback control. If it is determined that the recording sheet has reached the target position, the process returns to step S13 to check whether a series of recording operations have been completed.

  If it is determined that the recording operation has not been completed, the process returns to step S7 to continue the carriage movement and perform the recording operation. On the other hand, when a recording end command is sent from the host device 610, it is determined that the recording operation is ended, and the process proceeds to step S14, where the conveyance roller 16 is rotated by a predetermined amount to discharge the paper, and a series of recording operations are performed. finish.

  In the processing described above, the carriage 5 is moved in steps S7 to S9, and during that time, a carriage speed signal based on the encoder signal is input to the abnormality detector 110 at a constant cycle, and the carriage speed is set to the command value. Monitoring for whether or not a carriage operation abnormality occurs due to a large deviation from the above is executed. If an abnormal operation of the carriage is detected, the MPU 601 issues a command 107 for stopping the driving of the carriage motor 11 to the carriage motor driver 640 regardless of the above processing.

  Therefore, according to the embodiment described above, it is detected whether or not the carriage speed detected in the feedback control every 2 milliseconds is in an abnormal state greatly deviating from the command value, and it is determined that the carriage operation is abnormal. In such a case, the carriage motor can be stopped immediately and the carriage movement can be stopped.

  As a result, a paper floating phenomenon occurs depending on the operating environment of the device and the storage state of the recording medium, and even if the recording medium is caught by the carriage or recording head during the recording operation, the carriage is stopped immediately. Damage to the recording medium or damage to the recording head can be minimized.

  Note that even if no abnormality occurs in the operation of the carriage, the speed fluctuation width is different between the acceleration area and the constant speed area of the carriage, and the speed fluctuation width in the constant speed area is smaller than that in the acceleration area. Therefore, a determination value for determining an abnormal state may be provided for an acceleration region value and a constant speed region value.

  The present invention relates to a recording apparatus such as a printer, and more particularly to a recording apparatus that performs recording with a recording head mounted on a carriage that reciprocates along a guide shaft. The present invention is applied to a general printing apparatus, an apparatus such as a copying machine, a facsimile having a communication system, a word processor having a printing unit, and an industrial apparatus combined with various processing apparatuses. can do.

1 is an external perspective view showing a configuration of an ink jet recording apparatus that is a typical embodiment of the present invention. It is a block diagram which shows the control structure of the inkjet recording device shown in FIG. It is a block diagram which shows the structure of the conventional feedback control. It is a block diagram which shows the structure of the feedback control according to the Example of this invention. It is a figure which shows the time change of the carriage speed detected based on the encoder signal at the time of a normal carriage operation | movement, and a carriage position. It is a figure which shows the time change of the carriage speed detected based on the encoder signal at the time of an abnormal carriage operation | movement, and a carriage position. 6 is a flowchart illustrating a recording operation described mainly with respect to carriage movement control. It is a figure which shows the speed change of the carriage in 1 carriage scan.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording head 2 Platen 3 Guide shaft 4 Guide rail 5 Carriage 6 Head cartridge 7 Main tank 8 Joint part 9 Tube 10 Head cap 11 Carriage motor 12 Sheet supply part 13 Conveyance motor 14 Recovery unit 15 Pinch roller 16 Conveyance roller 17 Timing belt 19 Linear scale 20 Linear wheel 21 Encoder sensor 100 Command value generator 101 Command speed 102 PID compensator 103 PWM controller 105 Position detector 106 Speed detector 107 PWM command value 109 Control constant calculator 110 Abnormality detector 640 Carriage motor driver 644 Encoder controller

Claims (9)

A recording apparatus for recording on a recording medium by reciprocating a carriage mounted with a recording head,
Driving means for driving the carriage;
Detecting means for detecting the position and speed of the carriage driven by the driving means;
Command means for commanding the position and speed of the carriage;
A comparison unit that feeds back the position and speed of the carriage detected by the detection unit and compares them with a command value commanded by the command unit;
Drive control means for controlling the drive means to stop the carriage according to the comparison result by the comparison means,
The drive control means drives the drive means when the difference between the detected carriage position and speed and the command value corresponding to the detected value is larger than a predetermined threshold value, as a result of the comparison by the comparing means. A recording apparatus that outputs an instruction to stop the recording. The detection means includes
A scale disposed in the moving direction of the carriage;
An encoder mounted on the carriage and reading the scale according to the movement of the carriage;
The recording apparatus according to claim 1, further comprising a generating unit that generates a position signal and a speed signal of the carriage based on an output signal from the encoder. The driving means includes
A carriage motor;
The recording apparatus according to claim 1, further comprising a motor driver that drives the carriage motor.   The recording apparatus according to claim 3, wherein the carriage motor is a DC motor.   The recording apparatus according to claim 3, wherein the drive control unit issues an instruction to the motor driver to stop driving the carriage motor. The reciprocating movement of the carriage is divided into an acceleration movement section, a constant speed movement section, and a deceleration movement section of the carriage,
The drive control means controls the drive means based on the detected carriage speed in the acceleration movement section and the constant speed movement section, and based on the detected carriage position in the deceleration movement section. The recording apparatus according to claim 5, wherein the driving unit is controlled.   6. The recording apparatus according to claim 1, wherein feedback control based on detection by the detection unit and comparison by the comparison unit is performed about every 2 milliseconds.   The recording apparatus according to claim 1, wherein the recording head is an ink jet recording head that performs recording by discharging ink onto a recording medium. A recording control method for recording on a recording medium by reciprocating a carriage mounted with a recording head by a driving means,
A detection step of detecting the position and speed of the carriage driven by the driving means;
A commanding step for commanding the position and speed of the carriage;
A comparison step in which the carriage position and speed detected in the detection step are fed back and compared with the command value commanded in the command step;
A drive control step of controlling the drive means to stop the carriage according to the comparison result of the comparison step,
In the drive control step, if the difference between the detected carriage position and speed and the command value corresponding to the detected value is greater than a predetermined threshold value, the drive means is driven. A recording control method characterized by outputting an instruction to stop the recording.

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