JP2019163117A - Image formation apparatus and control method - Google Patents

Abstract

To provide an image formation apparatus capable of enhancing precision of conveyance control over a recording medium with simple constitution.SOLUTION: There is provided an image formation apparatus having: conveyance means which conveys a medium having an image formed, the recording medium being drawn out from a roll body; conveyance control means which performs drive control over a drive source for the conveyance means so that a conveyance quantity of the recording medium reaches a target conveyance quantity; pseudo-load imparting means which places a pseudo conveyance load on the recording medium in conveyance adjustment while varying the degree of the pseudo load; correlation information generation means which generates information correlating with an increase in output of the drive source in conveyance of the recording medium, the correlation information being made to correspond to the conveyance load placed while varied; correction information generation means which generates correction information for correcting a target conveyance quantity corresponding to each conveyance load upon the basis of a plurality of pieces of correlation information; correction information storage means which stores the correction information; and a target conveyance quantity correction means which corrects the target conveyance quantity by using the correction information.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus and a conveyance control method.

  In an image forming apparatus that uses a roll body wound in a roll shape as a recording medium, it is known that the conveyance load varies depending on the remaining amount of the roll body. If the transport load fluctuates, there will be a difference between the target transport amount of the roll body during the image forming process and the actual transport amount, leading to a reduction in image formation quality. There is a need to.

  Therefore, a technique is disclosed in which an auxiliary force corresponding to the conveyance speed of the roll body is applied to the roll motor in order to keep the winding tension constant so as to suppress fluctuations in the conveyance load (for example, Patent Document 1). . This technique corrects the conveyance amount according to the remaining amount of the roll body.

  When used with the technique disclosed in Patent Document 1, there is a problem that the speed control timing for controlling the correlation between the transport speed of the roll body and the transport roller becomes complicated. Further, since the inertia of the roll body with respect to the conveying force varies depending on the size of the roll body, there is also a problem that it is difficult to obtain an optimal correction amount only by the remaining amount of the roll body. Furthermore, since there is a difference in conveying force depending on the type of roll body (recording medium) to be used, there is a further difficulty in obtaining an optimal correction amount.

  In addition, when the size and type of the print medium change, the amount of slippage of the print medium at the time of conveyance is different from the prediction, so that even if correction is performed, image quality may be deteriorated. Such a problem becomes particularly noticeable when performing high-speed printing. These problems can be solved by further adding a complicated structure so as to cope with various factors, but it is desirable to increase the accuracy of recording medium conveyance control with a simpler configuration.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can improve the accuracy of conveyance control of a recording medium with a simple configuration.

  In order to solve the above technical problem, according to one aspect of the present invention, a conveyance unit that conveys a recording medium that is an image-formed medium and is pulled out from a roll body, and a conveyance amount of the recording medium is a target conveyance A conveyance control unit that drives and controls the drive source of the conveyance unit so that the amount is equal to the amount, and is applied to the recording medium while varying the magnitude of a pseudo load that is a pseudo conveyance load on the recording medium during conveyance adjustment Correlation information generation that correlates with the increase in output of the driving source when the recording medium is conveyed and the correlation information corresponding to the conveyance load applied while being varied A correction information generating means for generating correction information for correcting the target transport amount corresponding to each transport load, and correction information for storing the correction information. Storage means, characterized in that it and a target transport amount correction means for correcting the target carry amount using the correction information.

  According to the present invention, it is possible to improve the accuracy of conveyance control of a recording medium with a simple configuration.

1 is a partially transparent perspective view of a schematic configuration of an embodiment of an image forming apparatus according to the present invention. 1 is a schematic diagram illustrating an image forming apparatus according to an embodiment from a side surface direction. FIG. 3 is a partially transparent plan view of an image forming unit provided in the image forming apparatus according to the embodiment. FIG. 6 is a perspective explanatory view around the conveyance roller for explaining the outline of conveyance control according to the embodiment. The block diagram which shows the outline | summary of the control part which concerns on this embodiment. The schematic diagram which shows typically the assumption by which correction | amendment information and an approximate expression which concern on this embodiment are produced | generated. Explanatory drawing explaining the command value change of the duty ratio (Duty ratio) of the PWM value of the conveyance speed in one normal rotation operation | movement (feed operation) of a conveyance roller. Explanatory drawing which shows an example of a PWM command value.

  In the image forming apparatus according to the present invention, in the operation of forming an image on a recording medium while conveying the roll-shaped recording medium, even if the roll diameters on the recording medium feeding side and the winding side change, the target The gist of the invention is that correction information for controlling the transport amount can be acquired with a simple configuration. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment of Image Forming Apparatus]
FIG. 1 is a diagram illustrating a schematic configuration of an inkjet recording apparatus 100 which is an embodiment of an image forming apparatus according to the present invention, partially seen from obliquely upward. FIG. 2 is a schematic view showing the inkjet recording apparatus 100 from the side surface direction. FIG. 3 is a plan view showing a part of the main part of the image forming unit 104 provided in the ink jet recording apparatus 100.

  As shown in FIG. 1, the ink jet recording apparatus 100 includes an apparatus main body 101, a feeding device 102, and a winding device 103. The feeding device 102 is an embodiment of a medium supply device that supplies, as a medium, a material to be transported wound in a roll disposed below the apparatus main body 101, and constitutes a first transport unit. The winding device 103 is an embodiment of a medium winding device that winds a medium disposed on the lower side of the apparatus main body 101, and constitutes a second transport unit. In addition, the conveyed object which is a medium is a sheet-like thing which can be wound in roll shape. For example, paper, coated paper, cardboard, OHP, plastic film, prepreg, silver foil and the like are included. In the description of this embodiment, a roll paper 120 in which paper is rolled is used as an example.

  The feeding device 102 holds a roll body 112 in which a sheet is wound around a hollow shaft 115. The winding device 103 is provided with a hollow shaft portion 114 that winds up a sheet, and the roll body 112 is wound around the hollow shaft portion 114. Note that the feeding device 102 and the winding device 103 may be configured integrally with the apparatus main body 101 instead of separately.

  The feeding device 102 supplies the roll paper 120 into the apparatus main body 101. Inside the apparatus main body 101, an image forming unit 104 for forming an image on the roll paper 120 supplied in the transport direction indicated by the B direction of the arrow in FIG. In the image forming unit 104, a guide rod 1 and a guide stay 2, which are guide members, are spanned on both side plates, and a carriage 5 is shown on the guide rod 1 and the guide stay 2 in the direction indicated by the arrow A in FIG. It is supported so as to be movable in the scanning direction. The winding device 103 winds up the roll paper 120 on which an image is formed.

  On one side in the main scanning direction, a main scanning motor 8 which is a driving source for reciprocating the carriage 5 is arranged. A timing belt 11 is wound around a driving pulley 9 rotated by the main scanning motor 8 and a driven pulley 10 arranged on the other side in the main scanning direction. The belt holding portion of the carriage 5 is fixed to the timing belt 11 and the carriage 5 is reciprocated in the main scanning direction by driving the main scanning motor 8.

  The carriage 5 is mounted with a plurality (four in this case) of recording heads 6a to 6d in which a liquid discharge head and a head tank that supplies liquid to the head are integrated. Here, the recording head 6a and the recording heads 6b to 6d are arranged by shifting the position of one head (for one nozzle row) in the sub-scanning direction orthogonal to the main scanning direction. In addition, the recording heads 6a to 6d are mounted with a nozzle row composed of a plurality of nozzles that eject droplets arranged in the sub-scanning direction and the droplet ejection direction facing downward.

  Each of the recording heads 6a to 6d has a plurality (for example, two rows) of nozzle rows. And about the recording heads 6a and 6b, the black droplet which is the same color is discharged from any nozzle row. The recording head 6c discharges cyan droplets from one nozzle row, and the other nozzle row is an unused nozzle row. Further, the recording head 6d discharges yellow droplets from one nozzle row and ejects magenta droplets from the other nozzle row.

  Thereby, for monochrome images, the recording heads 6a and 6b can be used to form an image with a width of two heads in the main scanning direction of one scan, and for color images, for example, the recording heads 6b to 6d are used. Thus, image formation can be performed. The head configuration is not limited to this, and a configuration in which a plurality of recording heads are all arranged in the main scanning direction may be used.

  An encoder sheet 12 is arranged along the moving direction of the carriage 5, and an encoder sensor 13 that reads the encoder sheet 12 is provided on the carriage 5. These encoder sheet 12 and encoder sensor 13 constitute a linear encoder 14 and detects the position and speed of the carriage 5 from the output of the linear encoder 14.

  In the recording area in the main scanning area of the carriage 5, the roll paper 120 is fed from the feeding device 102. Thereafter, the roll paper 120 is intermittently conveyed by the conveying unit 21 in the sub-scanning direction (paper conveying direction) orthogonal to the main scanning direction of the carriage 5. Each color ink is supplied to the head tanks of the recording heads 6a to 6d through a supply tube from an ink cartridge 70 which is a main tank that is replaceably attached to the apparatus main body 101. A maintenance / recovery mechanism 80 that performs maintenance / recovery of the recording heads 6 a to 6 d is disposed on one side of the carriage 5 in the main scanning direction, on the side of the conveyance guide member 25.

  As illustrated in FIG. 2, the transport unit 21 includes a transport roller 23 that transports the roll paper 120 fed from the feeding device 102, and a pressure roller 24 that is disposed to face the transport roller 23. The conveyance roller 23 and the pressure roller 24 constitute a conveyance control unit. A transport guide member 25 having a plurality of suction holes formed on the downstream side of the transport roller 23 and a suction fan 26 as suction means for performing suction from the suction holes of the transport guide member 25 are provided. Further, on the downstream side of the conveying unit 21, a cutter 27 is disposed as a cutting unit that cuts the roll paper 120 on which an image is formed by the recording heads 6a to 6d with a predetermined length.

  The roll body 112 of the feeding device 102 is obtained by winding a long sheet-shaped roll paper 120 around a hollow shaft 115 such as a paper tube as a core member. Here, the roll body 112 is either the one in which the end of the roll paper 120 is fixed to the hollow shaft 115 by bonding such as gluing, or the non-fixed one in which the end of the roll paper 120 is not bonded to the hollow shaft 115. Can also be installed.

  The roll paper 120 delivered from the feeding device 102 is conveyed by the conveying means 21 directly below the image forming unit 104 to form an image, and is taken up by the winding device 103. The feeding device 102 includes a feeding driving unit, and the winding device 103 includes a winding driving unit. Each of the feeding drive unit and the take-up drive unit has a drive motor. By controlling the drive motor, a constant torque is applied so that a constant tension is applied to the roll paper 120 being conveyed. However, the slack of the roll paper 120 is eliminated. This drive motor rotates in the direction of the arrow in FIG.

  As shown in FIG. 2, the guide body 130 that guides the roll paper 120 drawn from the roll body 112 of the feeding device 102 and the roll paper 120 that has been sucked downstream of the conveyance guide member 25 are disposed on the apparatus main body 101 side. A paper discharge guide member 131 for guiding is disposed. The winding device 103 has a hollow shaft portion 114 such as a paper tube as a core member. The leading end of the roll paper 120 is bonded to the hollow shaft portion 114 with a tape or the like.

  The inkjet recording apparatus 100 moves the carriage 5 in the main scanning direction at the time of image formation, and intermittently feeds the roll paper 120 drawn out from the roll body 112 of the feeding apparatus 102 and guided along the guide member 130 by the conveying means 21. Transport to. Then, the recording heads 6 a to 6 d are driven according to image information (printing information) to discharge droplets, whereby a required image is formed on the roll paper 120. The image-formed roll paper 120 is guided by the paper discharge guide member 131 and wound around the hollow shaft portion 114 in the winding device 103. The roll paper 120 on the conveyance roller 23 is conveyed while tension is applied from each of the feeding device 102 side and the winding device 103 side. Each tension (back tension and winding tension) at this time affects the accuracy (conveyance accuracy) of the transport amount of the roll paper 120.

  In the above description, the ink jet recording apparatus 100 including the feeding device 102 that holds the roll body 112 is an embodiment of the present invention. The form of the image forming apparatus according to the present invention is not limited to this. For example, the apparatus (liquid discharge apparatus) which discharges the liquid provided with the feeder 102 which hold | maintains the roll body 112 may be sufficient.

  The liquid discharge apparatus is an apparatus that includes a liquid discharge head or a liquid discharge unit and drives the liquid discharge head to discharge liquid. The apparatus for ejecting liquid includes not only an apparatus capable of ejecting liquid to an object to which liquid can adhere, but also an apparatus for ejecting liquid toward the air or liquid.

  The liquid discharge apparatus can include means for feeding, transporting, and discharging a liquid to which a liquid can adhere, a pre-processing apparatus, a post-processing apparatus, and the like. Examples of the liquid ejecting apparatus include an image forming apparatus that is an apparatus that ejects ink to form an image on paper, and a powder in which powder is formed in a layer to form a three-dimensional structure (three-dimensional structure). There is a three-dimensional modeling apparatus (three-dimensional modeling apparatus) that discharges a modeling liquid to a body layer. Further, the liquid ejection device is not limited to the one in which a significant image such as a character or a figure is visualized by the ejected liquid. For example, what forms a pattern etc. which does not have a meaning in itself, and what forms a three-dimensional image are also included.

  What the liquid can adhere to means that the liquid can be attached at least temporarily and adheres and adheres, or adheres and penetrates. Specific examples include recording media such as paper, recording paper, recording paper, film, cloth, etc., electronic parts such as electronic boards, piezoelectric elements, powder layers (powder layers), organ models, examination cells, and other media. Yes, unless specifically limited, includes everything that the liquid adheres to.

  The materials to which the above liquid can adhere are paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, and liquids such as textiles for clothing are temporary. What is necessary is just to be able to adhere. The liquid includes an ink, a treatment liquid, a DNA sample, a resist, a pattern material, a binder, a modeling liquid, a solution containing amino acid, protein, calcium, a dispersion liquid, and the like.

  In addition, the liquid ejection device includes a device in which the liquid ejection head and the device to which the liquid can adhere move relatively, but the present invention is not limited to this. Specific examples include a serial type apparatus that moves the liquid discharge head, a line type apparatus that does not move the liquid discharge head, and the like.

  Further, as the liquid ejecting apparatus, there is a processing liquid coating apparatus that ejects the processing liquid onto the paper in order to apply the processing liquid to the surface of the paper for the purpose of modifying the surface of the paper. In addition, there is an injection granulation apparatus that granulates fine particles of a raw material by spraying a composition liquid in which the raw material is dispersed in a solution through a nozzle.

  The liquid discharge unit described above is an assembly of functional parts and mechanisms integrated with a liquid discharge head, and is an assembly of parts related to liquid discharge. For example, the liquid discharge unit includes a combination of at least one of a head tank, a carriage, a supply mechanism, a maintenance / recovery mechanism, and a main scanning movement mechanism with a liquid discharge head. Here, the term “integration” includes, for example, a liquid discharge head, a functional component, and a mechanism that are fixed to each other by fastening, adhesion, engagement, and the like, and one that is held movably with respect to the other. Further, the liquid discharge head, the functional component, and the mechanism may be configured to be detachable from each other.

  For example, there is a liquid discharge unit in which a liquid discharge head and a head tank are integrated. Also, there are some in which the liquid discharge head and the head tank are integrated by being connected to each other by a tube or the like. Here, a unit including a filter may be added between the head tank and the liquid discharge head of these liquid discharge units. In addition, there is a liquid discharge unit in which a liquid discharge head and a carriage are integrated.

  Furthermore, some liquid ejection units are configured such that the liquid ejection head and the scanning movement mechanism are integrated by holding the liquid ejection head movably on a guide member that forms part of the scanning movement mechanism. In addition, there is a liquid discharge unit in which a liquid discharge head, a carriage, and a main scanning movement mechanism are integrated. Incidentally, the main scanning movement mechanism includes a guide member alone.

  In addition, there is a liquid discharge unit in which a cap member that is a part of the maintenance / recovery mechanism is fixed to a carriage to which the liquid discharge head is attached, and the liquid discharge head, the carriage, and the maintenance / recovery mechanism are integrated. . In addition, there is a liquid discharge unit in which a tube is connected to a liquid discharge head to which a head tank or a flow path component is attached, and the liquid discharge head and a supply mechanism are integrated. Incidentally, the supply mechanism includes a single tube and a single loading unit.

  Further, the pressure generating means to be used for the liquid ejection head is not limited. For example, a piezoelectric actuator (multilayer piezoelectric element) may be used. In addition, a thermal actuator using an electrothermal conversion element such as a heating resistor, an electrostatic actuator including a diaphragm and a counter electrode, or the like may be used. In addition, image formation, recording, printing, printing, printing, modeling, etc. in terms in the specification are all synonymous.

  Next, an outline of conveyance control in the inkjet recording apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 4 is a perspective explanatory view around the transport roller 23. As shown in FIG. 3, an encoder wheel 51 is attached to the shaft of the transport roller 23, and an encoder sensor 52 that reads the encoder wheel 51 is disposed on the apparatus main body side, thereby constituting a rotary encoder 50. .

  The transport roller 23 is rotated via a timing belt 61 and the like by a sub-scanning motor 60 that is a drive source of the transport unit 21.

  Therefore, the operation of the sub-scanning motor 60 is feedback controlled from the detection output of the rotary encoder 50 and the target conveyance amount, and the conveyance amount of the roll paper 120 is controlled by the rotation amount of the conveyance roller 23. This control is executed by the control unit 400 described later.

  Next, an overview of the control unit 400 of the inkjet recording apparatus 200 according to the present embodiment will be described with reference to the block explanatory diagram of FIG. While describing the configuration included in the control unit 400, the control method according to the embodiment of the present invention will also be described. The control unit 400 includes a CPU 401, an FPGA (Field Programmable Gate Array) 403, a RAM 411, a ROM 412, an NVRAM 413, a motor driver 414, and the like.

  Since the control unit 400 controls the entire inkjet recording apparatus 100, the control unit 400 constitutes a drive control unit that controls the conveyance state of the roll paper 120 to be the target conveyance amount. In addition, before performing the image forming process on the roll paper 120 and when adjustment related to the conveyance control of the roll paper 120 is performed (during conveyance adjustment), a pseudo load that is a pseudo conveyance load on the roll paper 120 is reduced. A pseudo load applying unit that applies the roll paper 120 while changing the size is also configured. In addition, a correlation information generating unit is also configured to generate correlation information that correlates with an increase in the output of the motor 417 when the roll paper 120 is being transported and that corresponds to the transport load applied while being varied. A correction information generation unit that generates correction information for correcting the target drive amount according to the transport load based on the plurality of correlation information is also configured. Further, information storage means for storing correction information is also configured. Further, a target transport amount correction unit that corrects the target transport amount using the correction information is also configured.

  A calculation unit 402 of the CPU 401 configuring the control unit 400 communicates with each unit of the FPGA 403.

  The FPGA 403 includes a CPU control unit 404 that communicates with the CPU 401, a memory control unit 405 that accesses a memory such as the ROM 412 and the RAM 411, stores and reads correction information, and an I2C control unit 406 that communicates with the NVRAM 413. It is composed.

  The FPGA 403 controls the suction fan 26 and the drive motor, and processes sensor signals such as a pseudo load application unit 409 and an encoder sensor 416 that are pseudo load application units that apply a pseudo load to the roll paper 120 being conveyed. A sensor processing unit 407 is provided.

  The pseudo load applying unit 409 is, for example, a state in which it is difficult to transport the roll paper 120 by changing the driving amount (suction duty) of the suction fan 26 and adjusting the suction force of the roll paper 120 with respect to the transport guide member 25 (platen). Form. The conveyance guide member 25 and the suction fan 26 constitute conveyance guide means. That is, the conveyance state of the roll paper 120 with respect to the suction duty is changed. Further, the pseudo load application unit varies the drive amount of the drive motor of the feeding device 102 and the winding device 103 to change either the back tension or the winding tension to the roll paper 120.

  The sensor processing unit 407 constitutes a generation unit that generates a position signal and a speed signal of the carriage 5 from the output signal of the linear encoder 42.

  Further, a motor control unit 408 that drives and controls the motor 417 of each unit including the main scanning motor 8 and a driving motor that drives the feeding device 102 and the winding device 103 is configured.

  The encoder sensor 416 includes an encoder sensor 41, an encoder sensor 52, a rotary encoder 302, and the like. The encoder sensor 41 is an encoder sensor of the linear encoder 42 that detects the position and speed of the carriage 5 described above. The encoder sensor 52 is an encoder sensor of the rotary encoder 50 that detects the rotation amount of the transport roller 23 and the like. The rotary encoder 302 is an encoder sensor of the paper feeding unit.

  In the pseudo load application unit 409, correlation information is generated by correlating the rotation amount of the encoder sensor 52 of the rotary encoder 50 generated in the sensor processing unit 407 in response to varying the amount of pseudo load. The An example of the correlation information is shown in FIG. 6A shows an example of the correlation between the suction duty and the motor PWM value, and FIG. 6B shows an example of the correlation between the suction duty or the back tension or the winding tension and the conveyance correction amount.

  A correlation between the pseudo load amount by the pseudo load application unit 409 and the rotation amount of the transport roller 23 detected by the sensor processing unit 407 is calculated, and based on this, an approximate expression is generated as shown in FIG. Correction information can be generated based on the formula. The generated correction information has a data structure that defines the conveyance correction amount for the motor PWM value. This is stored in the correction information storage means constituted by NVRAM 413 or the like.

  In addition to the main scanning motor 8 described above, the motor 417 includes a sub-scanning motor 60 that drives the conveyance roller 23 to rotate, a driving motor, and the like. For example, a DC motor or a stepping motor can be used as the motor.

  Here, the operation of the sub-scanning motor 60 included in the motor 417 will be described. The CPU 401 instructs the motor control unit 408 about the moving speed and the moving distance together with the operation start instruction. Upon receiving an instruction from the CPU 401, the motor control unit 408 creates a drive profile from the speed instruction / movement distance instruction information and the above-described correction information, and passes through the sensor processing unit 407 from the encoder sensor 52 included in the encoder sensor 416. Comparison with the encoder information obtained. Then, the PWM command value is calculated, and the PWM command value is output to the motor driver 414.

  When the motor control unit 408 finishes the predetermined operation, the motor control unit 408 notifies the CPU 401 of the operation end, and the CPU 401 receives an operation end instruction.

  Note that instead of the motor control unit 408 creating a drive profile, the CPU 401 may create a drive profile and give an instruction to the motor control unit 408.

  That is, here, the CPU 401 and the motor control unit 408 constitute drive control means for driving and controlling the sub-scanning motor 60 that is the drive source of the transport roller 23 by PWM control.

  Next, an example of conveyance control for conveying the roll paper 120 in the inkjet recording apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 7 is an explanatory diagram for explaining a change in the command value of the duty ratio (Duty ratio) of the PWM value of the conveyance speed in one normal rotation operation (feed operation) of the conveyance roller 23.

  In the present embodiment, drive control of the sub-scanning motor 60 that rotates the conveyance roller 23 is performed by PWM control, and is performed by a servo system having a PI control loop. In this system, the carriage speed is controlled by changing a command value (PWM command value) that determines the duty ratio of PWM. Here, it is assumed that the PWM command values are assigned as shown in FIG. 8, for example. Based on this, an example of controlling the motor speed by controlling the duty ratio of PWM will be described.

  First, the speed error (Ve) is calculated by subtracting the moving speed of the controlled object (here, the conveyance roller 23) or the rotational speed of the motor detected by the position and speed detecting means such as an encoder from the externally designated speed. .

  Next, an operation amount (here, a duty ratio of PWM) is calculated using, for example, the following equation (1). In equation (1), Kp is a proportional control constant, and Ki is an integral control constant.

  Based on the calculated value by the equation (1), the speed control of the conveying roller 23 is performed by changing the PWM command value given to the motor driver 414.

  In this embodiment, PI control is performed, but PID (proportional integral derivative) control can also be performed.

  Returning to FIG. 7, in the speed control of the transport roller 23, the transport roller 23 is gradually accelerated in the acceleration region after the start of the sub-scanning motor 60, and then the control shifts to the constant speed control, and the target position (target transport amount) When approaching, the operation shifts to the deceleration region, and the sub-scanning motor 60 is quickly decelerated and stopped.

  As described above, a pseudo load is applied while the roll paper 120 is being conveyed, and the information from the sensor obtained as a result is used to obtain the PWM value for the load. Thus, the correction information can be generated as described above. The generated correction information can be stored in the NVRAM 413 or the like and used for correcting the target carry amount when the inkjet recording apparatus 100 executes the image forming process.

  In generating the correction information, the conveyance amount with respect to the pseudo load amount also changes depending on the type of the roll paper 120. Therefore, the operation for generating correction information (during conveyance adjustment) is performed when the user replaces the roll paper 120 or when a test pattern for adjusting the conveyance amount is used for image formation.

  As described above, when the torque applied by the driving motor of the feeding device 102 is constant in the inkjet recording apparatus 100 according to the present embodiment, the back tension increases as the diameter of the roll body 112 decreases. As the back tension increases, the slip between the transport roller 23 and the roll paper 120 increases. Thereby, the actual transport amount is reduced. In this case, the output of the transport motor is high.

  Therefore, in the present embodiment, when the conveyance amount is adjusted, the conveyance load is artificially increased, and an environment similar to the case where the diameter of the roll paper 120 is reduced is created in a pseudo manner, and the conveyance is performed according to the magnitude of the pseudo load. A change state is created in which the amount decreases and the output of the transport motor increases.

  A plurality of conveyance amount and motor output data are acquired and a correction value is generated. This correction value is stored and used for correction processing for the target carry amount in carry drive control when image formation is performed.

  As means for increasing the conveyance load in a pseudo manner, the suction duty of the platen is increased, the back tension is increased by controlling the drive motor, or the winding tension is increased.

  In this case, at least the suction duty when sucking the roll paper 120 during normal image formation is set as the “default condition”, and one intentionally increased suction duty is set as the “load condition”. Then, an approximate expression is generated using the motor PWM value of the drive motor under the default condition and the motor PWM value of the drive motor under the load condition. Using the generated approximate expression, a conveyance correction amount based on the motor PWM value is calculated, and correction information including this as data is generated and stored. In this way, by performing the conveyance adjustment process, it is possible to prepare a conveyance correction amount corresponding to the motor PWM value and suitable for the roll paper 120 to be conveyed from now on at the time of adjustment before executing the image forming operation. it can.

  During the conveyance control for executing image formation, the motor PWM value is monitored, the target conveyance amount is corrected based on the correction information, and the conveyance drive control is executed. The generated approximate expression is stored, and when carrying control based on image formation, the correction information is calculated by applying the acquired motor PWM value to the approximate expression, and the target drive amount is calculated using the calculated correction information. Correction may be performed.

  As the motor PWM value, a value for each conveyance may be used. However, since it is likely to vary, it is preferable to use an average value obtained immediately before a plurality of times.

  Or if it is a case where the structure which can calculate a roll diameter is provided, the range of a roll diameter may be divided | segmented and the average value of a motor PWM value may be calculated in the range of each roll diameter. Alternatively, the approximate expression may be acquired or the correction information may be generated by temporarily transporting the roll paper 120 before executing the image forming operation.

  In addition, if the variation of the motor PWM value is taken into account, the roll diameter does not change greatly within the same range of print jobs that constitute a unit of image forming processing. It is better not to.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the technical scope thereof, and all the technical matters included in the technical idea described in the claims are included. The subject of the present invention. The above-described embodiments show preferred examples, but those skilled in the art can realize various modifications from the disclosed contents, and these are described in the appended claims. Included in the technical scope.

1: Guide rod 2: Guide stay 5: Carriage 6a: Recording head 6b: Recording head 6c: Recording head 6d: Recording head 8: Main scanning motor 9: Drive pulley 10: Driven pulley 11: Timing belt 12: Encoder sheet 13: Encoder sensor 14: Linear encoder 21: Conveying means 23: Conveying roller 24: Pressure roller 25: Conveying guide member 26: Suction fan 27: Cutter 41: Encoder sensor 42: Linear encoder 50: Rotary encoder 51: Encoder wheel 52: Encoder Sensor 60: Sub-scanning motor 61: Timing belt 70: Ink cartridge 80: Maintenance / recovery mechanism 100: Inkjet recording apparatus 101: Apparatus main body 102: Feeding apparatus 103: Winding apparatus 104: Image forming unit 112: Low Body 114: the hollow shaft portion 115: hollow shaft portion 120: the roll paper 130: guide member 131: discharge guide member 302: rotary encoder 400: Control unit 401: CPU
402: Operation unit 403: FPGA
404: CPU control unit 405: Memory control unit 406: I2C control unit 407: Sensor processing unit 408: Motor control unit 409: Pseudo load applying unit 411: RAM
412: ROM
413: NVRAM
414: Motor driver 416: Encoder sensor 417: Motor

JP 2013-22084 A

Claims (6)

A transport means for transporting a recording medium that is an image-formed medium and is drawn from the roll body;
A transport control unit that drives and controls a drive source of the transport unit so that the transport amount of the recording medium becomes a target transport amount;
Pseudo load application means for applying to the recording medium while varying the magnitude of the pseudo load that is a pseudo conveyance load for the recording medium during conveyance adjustment;
Correlation information generating means for generating correlation information corresponding to the transport load applied while being variable, the information correlating to an increase in output of the drive source when transporting the recording medium;
Correction information generating means for generating correction information for correcting the target transport amount corresponding to each transport load based on a plurality of the correlation information;
Correction information storage means for storing the correction information;
Target transport amount correction means for correcting the target transport amount using the correction information;
An image forming apparatus comprising: The correction information generation means generates the correction information by an approximate expression using the correlation information corresponding to each transport load.
The image forming apparatus according to claim 1. A conveyance guide means for guiding conveyance of the recording medium;
The pseudo load applying means uses a suction force for sucking the recording medium by the transport guide means as a transport load.
The image forming apparatus according to claim 1. The transport unit includes a first transport unit that feeds the recording medium in a transport direction, and a second transport unit that winds the recording medium,
The pseudo load applying means includes
The back tension applied to the recording medium by the first transport unit is used as a transport load.
The image forming apparatus according to claim 1. The transport unit includes a first transport unit that feeds the recording medium in a transport direction, and a second transport unit that winds the recording medium,
The pseudo load applying means includes
The winding tension applied to the recording medium by the second transport means is used as a transport load.
The image forming apparatus according to claim 1. Convey the recording medium pulled out from the roll body, which is the medium on which the image is formed,
Drive control of the drive source so that the transport amount of the recording medium becomes the target transport amount,
Applying to the recording medium while varying the magnitude of the pseudo load that is a pseudo conveyance load for the recording medium during conveyance adjustment,
Information correlating with an increase in output of the drive source when the recording medium is being transported, and generating correlation information corresponding to the transport load applied while being varied,
Based on a plurality of the correlation information, generating correction information for correcting the target transport amount corresponding to each transport load,
Storing the correction information;
Correcting the target transport amount using the correction information;
A control method characterized by that.