JP5950537B2 - Recording apparatus, conveyance apparatus, and sheet conveyance control method - Google Patents

Description

  The present invention relates to a recording apparatus, a conveyance apparatus, and a sheet conveyance control method, and more particularly to a recording apparatus, a conveyance apparatus, and a sheet conveyance control method that use a sheet wound in a roll shape as a sheet.

  In recent years, there has been an increasing demand for higher image quality in recording apparatuses. As countermeasures, it is conceivable to improve the recording accuracy of the recording head (for example, in the case of an ink jet recording apparatus, the ink ejection amount and ejection timing), the operation accuracy of the carriage on which the recording head is mounted, and the sheet conveyance accuracy. .

  In a recording apparatus that records on a sheet wound in a roll shape, attention is paid to the conveyance accuracy among the above measures. 2. Description of the Related Art A conveyance device that conveys a sheet by pulling out a sheet wound in a roll shape in a supply unit and sandwiching the pulled sheet between a conveyance roller and a driven roller is known. If a load is applied to the roll core by a torque limiter or the like, a back tension is applied to the sheet between the supply unit and the conveyance roller in a direction opposite to the conveyance direction, and applied to the sheet between the supply unit and the conveyance roller. Appropriate tension can be generated. If the back tension is not sufficient, the sheet may become slack and cause skewing. If the back tension is excessive, on the other hand, slippage occurs between the roller and the sheet, and accurate conveyance cannot be performed.

  As a countermeasure, for example, Japanese Patent Application Laid-Open No. H10-228561 describes that braking of the driving of the motor on the supply unit side is started when a difference occurs between the sheet speed in the conveyance roller and the sheet speed in the supply unit. ing.

JP 2009-2242047 A

  There is a time lag between the detection of the sheet speed and the control of the motor, and particularly when large roll paper is used, the rotation speed of the roll becomes the target value after the motor control is started. The time until is longer.

  However, in the control method of Patent Document 1, since the control of the motor on the roll side is started after detecting the difference in sheet speed between the conveyance roller side and the roll side, this problem cannot be solved.

  Accordingly, an object of the present invention is to synchronize the sheet speed on the conveyance roller and the sheet speed on the outer periphery of the roll in a recording apparatus and a conveyance apparatus that pulls out a roll sheet and conveys the sheet by a conveyance roller.

In order to achieve the above object, according to the present invention, there is provided a recording apparatus that pulls out a roll-shaped sheet, conveys the sheet by rotating a conveyance roller, and records on the sheet, the conveyance speed of the sheet Generating means for generating the command value, a transport motor for rotating the transport roller, a first control means for controlling the transport motor based on the command value and the rotation speed of the transport roller, and the command value A calculation means for calculating the amount of change per unit time of the rotation speed of the transport roller as an acceleration, a supply motor for rotating the roll-shaped sheet, and a measurement means for measuring the radius of the portion wound in the roll shape When a second control means for controlling the supply motor based the rotational speed of the conveying roller and the rotational speed and the radius of the rolled sheet and the acceleration Recording apparatus comprising: a is provided.

According to another aspect of the present invention, there is provided a recording apparatus that pulls out a roll-shaped sheet and conveys the sheet by rotating a conveyance roller, and records on the sheet, and generates a command value for the conveyance speed of the sheet. A generating unit; a conveying motor that rotates the conveying roller; a first control unit that controls the conveying motor based on the command value and a speed of the sheet on the conveying roller; and the conveying roller based on the command value. Calculating means for calculating the amount of change per unit time of the rotation speed as an acceleration, a supply motor for rotating the roll-shaped sheet, the speed of the sheet in the conveying roller, and the sheet on the outer periphery of the roll-shaped sheet recording apparatus Hisage, characterized in that it comprises a second control unit for controlling the supply motor based speed between the said acceleration It is.

Further, according to the present invention, there is provided a conveyance device that conveys the sheet by pulling a roll-shaped sheet and rotating a conveyance roller, the generation unit generating a command value of the conveyance speed of the sheet, and the conveyance A transport motor for rotating the roller, first control means for controlling the transport motor based on the command value and the rotational speed of the transport roller, and a rotational speed of the transport roller based on the command value per unit time. Calculation means for calculating the amount of change as acceleration, supply motor for rotating the roll-shaped sheet, measurement means for measuring the radius of the portion wound in the roll shape, rotation speed of the conveying roller, and roll shape providing transport device and a second control means for controlling the supply motor based sheet speed and the radius of the said acceleration, characterized in that it comprises for the It is.

Further, according to the present invention, there is provided a method for controlling the conveyance of the sheet performed by pulling out a roll-shaped sheet and rotating a conveyance roller, wherein a command value for the conveyance speed of the sheet is generated, and a conveyance motor is , Rotating the transport roller, controlling the transport motor based on the rotational speed based on the command value and the rotational speed of the transport roller, and changing the rotational speed of the transport roller based on the command value per unit time It calculates the amount as the acceleration, feed motor, the rolled sheet rotates, the radius of the roll-wound portion was measured, the rotational speed of the rolled sheet and the rotational speed of the conveying roller and A method is provided for controlling the supply motor based on the radius and the acceleration.

  According to the present invention, the command value of the conveyance speed used for controlling the conveyance motor is also used for controlling the supply motor. Therefore, when changing the conveyance speed such as acceleration / deceleration, the second control unit can control the rotation speed of the supply motor using information obtained from the command value of the conveyance speed before detecting the change in the conveyance roller speed. Therefore, according to the present invention, in the recording apparatus and the conveying apparatus that pulls out the roll-shaped sheet and conveys it by the conveying roller, the sheet speed on the conveying roller and the sheet speed on the outer periphery of the roll can be synchronized.

1 is a diagram illustrating an overall configuration of an ink jet recording apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a sheet feeding / conveying mechanism and a sheet feeding / conveying control unit of the recording apparatus illustrated in FIG. 1. FIG. 6 is a diagram illustrating a relationship between a conveyance speed, a sheet feeding speed, and a tension related to a sheet in a conventional recording apparatus. FIG. 4 is a diagram illustrating a relationship among a conveyance speed, a sheet feeding speed, and a tension related to a sheet in the recording apparatus according to the embodiment of the invention. FIG. 6 is a diagram illustrating a configuration of a sheet feeding / conveying mechanism and a sheet feeding / conveying control unit of a recording apparatus according to another embodiment of the invention.

  Hereinafter, preferred embodiments of the present invention will be described more specifically and in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the already demonstrated part and duplication description is abbreviate | omitted.

  In this specification, “recording” (sometimes referred to as “printing”) is not limited to the case of forming significant information such as characters and graphics, but may be significant. In addition, a case where an image, a pattern, a pattern, or the like is widely formed on a sheet, or a medium is processed, regardless of whether or not it has been revealed so that a human can perceive it visually.

  In this embodiment, roll paper is used as the sheet, but other than that, for example, a roll wound cloth, a plastic film, or the like may be used.

<Overall configuration of inkjet recording apparatus>
FIG. 1 is a diagram showing an overall configuration of an ink jet recording apparatus (hereinafter referred to as a recording apparatus) according to an embodiment of the present invention.

  First, a configuration for recording on a sheet will be described. The recording head 107 is an ink jet recording head that includes an ink tank that stores ink to be supplied to the recording head 107 and performs recording by discharging ink according to an ink jet method. The ink tanks are provided with mat black (MBk), magenta (M), cyan (C), yellow (Y), and black (K), and these five ink tanks can be attached and detached independently. . The recording head 107 is mounted on the carriage 109.

  The carriage 109 is supported by the guide shaft 110 so as to be able to reciprocate along the carriage driving direction. Both ends of the guide shaft 110 are fixed to the chassis 111. By driving the carriage motor 112, the carriage 109 is driven via the belt 113 engaged with the carriage 109. With this configuration, the recording head 107 performs recording by ejecting ink in the recording area while reciprocating the carriage 109. Further, a sheet sensor 114 capable of detecting the presence / absence of a sheet and an end portion of the sheet is disposed on the side surface of the carriage 109, and the width of the sheet can be detected by reciprocating the carriage 109. . Further, the amount of skew of the sheet can be detected by conveying the sheet by a predetermined amount (for example, 300 mm) and detecting the sheet end position before and after the conveyance.

  Note that the recording head 107 according to the present embodiment employs an ink jet system that ejects ink using thermal energy. For this reason, the recording head 107 includes a heating resistance element. The heating resistance element is provided corresponding to each of the discharge ports, and applies a pulse voltage corresponding to the recording signal to the corresponding heating resistance element. Thereby, ink is ejected from the corresponding ejection port. However, the present invention is not limited to this, and various ink jet methods such as a method using a piezo element, a method using an electrostatic element, and a method using a MEMS element may be adopted.

  Next, a configuration for conveying a sheet will be described. In the present embodiment, roll paper is used as the roll sheet. The roll paper 101R, which is a roll-shaped part, is held rotatably around the roll axis by the paper supply unit (supply unit) 103 with the spool 102 as a roll axis, and is fed by pulling out one end. Paper (supplied). The fed sheet 101 </ b> S is sandwiched between the transport roller 104 and the pinch roller 105. The pinch roller 105 is pressed against the sheet 101S by a pinch roller spring (not shown). The conveyance roller 104 and the roll paper 101R are rotated (and the pinch roller 105 is driven to rotate), and the sheet 101S is conveyed in the conveyance direction. When the part to be recorded on the sheet 101S reaches the platen 106, the conveyance is stopped, and the recording head 107 performs recording on this part. After recording is performed, the sheet 101S is transported again, and transport and recording are performed alternately (that is, recording is performed while intermittently transporting). When all of the series of recordings are completed, the sheet 101S is conveyed to a predetermined cutting position and is cut by the cutter 108.

<Configuration of paper feed / conveyance mechanism>
FIG. 2 is a diagram illustrating the configuration of the sheet feeding / conveying mechanism and the sheet feeding / conveying control unit of the recording apparatus illustrated in FIG. 1. First, the paper feeding / conveying mechanism (right side in FIG. 2) will be described here.

  On the conveyance side, a gear 201 is coaxially attached to the conveyance roller 104, and a driving torque of the conveyance motor 202 is transmitted via a belt 205 engaged with the gear 201 and the conveyance motor 202. Further, in order to detect the rotation angle of the transport roller 104, the transport roller 104 is provided with a transport encoder film 203 coaxially, and on the main body side, a corresponding transport encoder sensor 204 is provided.

  On the paper feed side, a gear 211 is coaxially attached to the spool 102 that holds the roll unit 101R, and the driving torque of the paper feed motor (supply motor) 212 is transmitted through the gear 211. Further, in order to detect the rotation angle of the spool 102, the spool 102 is provided with a paper feed encoder film 213 coaxially, and a paper feed encoder sensor 214 corresponding thereto is provided on the main body side.

  Further, a reference side roll paper holder 215 a and a non-reference side roll paper holder 215 b are attached to both ends of the spool 102. The reference side roll paper holder 215a includes a plurality of light emitting devices 216a arranged in the radial direction of the roll paper 101R, and the non-reference side roll paper holder 215b includes an optical sensor 216b. The light sensor 216b receives the light from the light emitting device 216a and measures the radius of the roll paper 101R.

<Control method of paper feed / conveyance mechanism>
FIG. 3 is a diagram illustrating a relationship between the conveyance speed V _LF , the sheet feeding speed V _FD , and the tension T relating to the sheet 101S in the conventional recording apparatus. Here, V _LF is the sheet speed at the transport roller 104 and is a value obtained by multiplying the rotation speed RV _LF of the transport roller 104 by the radius of the transport roller R _LF . V _FD is the sheet speed on the outer periphery of the roll portion 101R, and is a value obtained by multiplying the rotational speed RV _FD of the spool 102 by the winding diameter R _FD of the roll portion (the same applies to FIG. 4).

  In this case, when the rotation of the conveyance roller 104 is accelerated, a change in the rotation speed of the spool 102 follows the change in the rotation speed of the conveyance roller with a delay, so that a large tension is generated in the sheet 101S. On the other hand, slack occurs in the sheet 101S during deceleration.

FIG. 4 is a diagram illustrating a relationship between the conveyance speed V _LF , the sheet feeding speed V _FD , and the tension T related to the sheet 101S in the recording apparatus of the present embodiment. According to the acceleration / deceleration of the rotation of the conveying roller 104, the rotation of the spool 102 can be accelerated / decelerated simultaneously. Therefore, the relationship of V _LF = V _FD is maintained even during acceleration / deceleration, and as shown in FIG. 4, it is possible to prevent large tension and looseness from occurring in the sheet 101S. A configuration for performing control as shown in FIG. 4 will be described below.

<Configuration of paper feed / conveyance control unit>
Next, the configuration (mainly the left side in FIG. 2) of the paper feed / conveyance control unit for performing the above control will be described. Although not shown, the controller 220 includes a CPU (MPU), a RAM, a ROM, an ASIC, and the like. Each component in the controller 220 may be realized by the CPU executing a program stored in the ROM, or may be realized by a dedicated circuit such as an ASIC.

On the transport side, the speed command generator 221 generates a command value RV _LF0 for the rotational speed of the transport roller 104. The first speed calculation unit 222 calculates the rotation speed RV _LF1 of the transport roller 104 from the signal detected by the transport encoder sensor 204. The first controller 223 calculates a PWM value PWM _LF as an operation amount from a difference value between the command value RV _LF0 and the calculated rotation speed RV _LF1 . The calculated PWM value PWM _LF is output to the transport motor driver 230, and the transport motor driver 230 drives the transport motor 202 by _supplying a current I _LF corresponding to the operation amount to the transport motor 202.

On the paper feed side, the second speed calculation means 225 calculates the rotation speed RV _LF1 of the spool 102 from the signal detected by the paper feed encoder sensor 214. The speed converter 224 receives the rotation speed RV _LF1 of the transport roller 104 and the winding diameter (radius) R _{FD of the} roll unit 101R, and generates a target value RV _FD0 of the rotation speed of the spool 102. Specifically, when the radius of the transport roller is R _LF (constant), RV _FD0 = RV _LF1 × (R _LF / R _FD ). The second controller 226 calculates a PWM value PWM _{FD serving} as an operation amount from a difference value between the target value RV _FD0 and the calculated rotation speed RV _FD1 . A correction value PWM _ADJ based on the acceleration information of the conveying roller is output from the differential calculator 227 and added to the calculated PWM value PWM _FD to correct the PWM value. The paper feed motor driver 240 receives the corrected PWM value as input, and causes the paper feed motor 212 to drive the paper feed motor 212 by _supplying a current _IFD corresponding to the operation amount. Here, the acceleration information is obtained by the differential calculator 227 with the amount of change per unit time of the command value RV _LF0 generated by the speed command generator 221.

In the present embodiment, the acceleration information is obtained by the differential calculator 227 and the correction value correction value PWM _ADJ is output. However, the speed command generator 221 may output the correction value directly.

<Effect of this embodiment>
In the configuration shown in FIG. 2, the speed information (acceleration information) generated by the speed command generator is also output to the paper feed side. For this reason, when changing the transport speed such as acceleration / deceleration, the paper feed side can control the rotation speed of the paper feed motor using the generated speed information before the sensor or the like detects it. Therefore, according to the present embodiment, in the recording apparatus that pulls out a roll-shaped sheet and conveys it by the conveyance roller, the sheet speed on the conveyance roller and the sheet speed on the outer periphery of the roll can be synchronized.

  Furthermore, the configuration of the transport / feed mechanism and its control system according to the present embodiment can also be applied to a transport apparatus.

<About other embodiments>
FIG. 5 is a diagram illustrating a configuration of a sheet feeding / conveying mechanism and a sheet feeding / conveying control unit of a recording apparatus according to another embodiment of the present invention. Here, the description of the same configuration as in FIG. 2 is omitted.

On the transport side, the transport speed V _LF1 is calculated by the first speed calculation means 222 from the signal detected by the first speed detector 207 provided near the transport roller. The first controller 223 calculates a PWM value PWM _{LF serving} as an operation amount from the difference value between the transport speed command value V _LF0 generated by the speed command generator 221 and the calculated transport speed V _LF1 .

On the paper feed side, the paper feed speed V _FD1 is calculated by the second speed calculation means 225 from the signal detected by the second speed detector 217 provided near the roll unit 101R. The second controller 226 calculates a PWM value PWM _{FD serving} as an operation amount from the difference value between the calculated transport speed V _LF1 and the paper feed speed V _FD1 . A correction value PWM _ADJ based on the acceleration information of the conveying roller is output from the differential calculator 227 and added to the calculated PWM value PWM _FD to correct the PWM value.

In this configuration, for example, an LDV (laser Doppler velocimeter) is used as the speed detection means. However, the present invention is not limited to this, and since the radius of the transport roller 104 is constant, the encoder film 203 and the encoder sensor 204 may be used on the transport side as in the embodiment shown in FIG. Further, on the sheet feeding side, a roller biased so as to be pressed against the outer periphery of the roll unit 101R is provided, the (driven) rotation of this roller is detected, and the sheet speed on the outer periphery of the roll unit 101R is determined as the sheet feeding speed V. _The configuration may be calculated as _FD1 .

  In the configuration of the present embodiment, the conveyance / paper feed speed is calculated regardless of the radii of the conveyance roller 104 and the roll unit 101R. Therefore, an apparatus (light emitting device 216a) for detecting the roll diameter as shown in FIG. And the optical sensor 216b) and the speed converter 224 are not required.

Claims (4)

A recording apparatus that pulls out a roll-shaped sheet and conveys the sheet by rotating a conveyance roller, and records on the sheet,
Generating means for generating a command value of the sheet conveying speed;
A transport motor for rotating the transport roller;
First control means for controlling the transport motor based on the command value and the rotational speed of the transport roller;
Calculating means for calculating the amount of change per unit time of the rotation speed of the transport roller based on the command value as acceleration;
A supply motor for rotating the roll-shaped sheet;
Measuring means for measuring a radius of the portion wound in the roll shape;
Second control means for controlling the supply motor based on the rotation speed of the transport roller, the rotation speed of the roll-shaped sheet, the radius, and the acceleration;
A recording apparatus comprising: A recording apparatus that pulls out a roll-shaped sheet and conveys the sheet by rotating a conveyance roller, and records on the sheet,
Generating means for generating a command value of the sheet conveying speed;
A transport motor for rotating the transport roller;
First control means for controlling the transport motor based on the command value and the speed of the sheet in the transport roller;
Calculating means for calculating the amount of change per unit time of the rotation speed of the transport roller based on the command value as acceleration;
A supply motor for rotating the roll-shaped sheet;
Second control means for controlling the supply motor based on the speed of the sheet on the conveying roller and the speed and acceleration of the sheet on the outer periphery of the roll-shaped sheet;
A recording apparatus comprising: A conveyance device that conveys the sheet by pulling out a roll-shaped sheet and rotating a conveyance roller,
Generating means for generating a command value of the sheet conveying speed;
A transport motor for rotating the transport roller;
First control means for controlling the transport motor based on the command value and the rotational speed of the transport roller;
Calculating means for calculating the amount of change per unit time of the rotation speed of the transport roller based on the command value as acceleration;
A supply motor for rotating the roll-shaped sheet;
Measuring means for measuring a radius of the portion wound in the roll shape;
Second control means for controlling the supply motor based on the rotation speed of the transport roller, the rotation speed of the roll-shaped sheet, the radius, and the acceleration;
A conveying device comprising: A method of controlling the conveyance of the sheet performed by pulling out a roll-shaped sheet and rotating a conveyance roller,
Generating a command value of the sheet conveyance speed;
A conveyance motor rotates the conveyance roller,
Controlling the transport motor based on the rotational speed based on the command value and the rotational speed of the transport roller;
The amount of change per unit time of the rotation speed of the transport roller based on the command value is calculated as acceleration,
A supply motor rotates the roll-shaped sheet,
Measure the radius of the rolled part,
A method of controlling the supply motor based on a rotation speed of the conveying roller, a rotation speed of the roll-shaped sheet, the radius, and the acceleration.

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