JP2008000980A - Printing apparatus, conveying apparatus, and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control with a high accuracy a stopping position of a medium conveyed in a printing apparatus. <P>SOLUTION: A winding roller 108, a conveying controlling part 114 and a printing part 112 are equipped. The conveying controlling part 114 is equipped with a command outputting part 202 and a part 206 for detecting the amount of overrun. The command outputting part 202 outputs a stopping command for stopping rotation of the winding roller 108 respectively corresponding to at least two positions which are a middle position before a medium 30 reaches a target position and the target position, during conveying the medium 30 between a time when the preceding printing is performed and a time when the next printing is performed. The part 206 for detecting the amount of overrun detects the amount of overrun of the winding roller 108 when the command outputting part 202 outputs the stopping command corresponding to the middle position. When the stopping command corresponding to the target position is outputted, the command outputting part 202 outputs the stopping command at a timing when the medium 30 reaches a position where a distance corresponding to the amount of detected overrun is subtracted from the target position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing apparatus, a conveying apparatus, and a printing method.

  For example, the printing apparatus performs printing by transporting a medium to the feed target position. In this case, in order to stop the conveyance of the medium, for example, a stop command is given to a conveyance roller that conveys the medium. However, the transport roller or the like may not stop immediately after receiving a stop command, and an overrun may occur.

Therefore, conventionally, for example, by outputting a stop command at a point where the predicted overrun amount is subtracted, and then expecting to advance by the predicted overrun amount, positioning of the stop position of the medium is performed. I was going. For example, conventionally, there is known an automatic document feeder provided with a predicting unit that predicts the number of overrun pulses from the start of the stopping operation of the conveying unit to the actual stop (see, for example, Patent Document 1). Conventionally, thermal transfer that corrects the timing of outputting a stop command (stop command timing) by performing an overrun amount detection operation at the time of mechanical initialization of the device (immediately after application of power, reset at the time of trouble occurrence, etc.) A recording apparatus is known (see, for example, Patent Document 2).
Japanese Unexamined Patent Publication No. 7-17658 JP-A-5-96760

  The amount of overrun varies depending on environmental conditions, differences between devices, media conditions, and the like. The environmental conditions are, for example, the temperature and humidity of the atmosphere. The inter-device difference is, for example, friction generated when a medium is transported different for each device, an assembly error of the device, or the like. The media conditions are, for example, the material, thickness, width, etc. of the medium. When a medium roll in which the medium is wound into a roll is used, for example, the diameter of the medium roll is also a media condition. When predicting the overrun amount, it is necessary to derive an appropriate overrun amount in consideration of these various conditions. However, in this case, the following problems occur.

  For example, when the overrun amount is predicted, it is necessary to create a function or a table that can obtain the overrun amount if the environmental condition and the media condition are given. For this purpose, an experiment or the like is required. Furthermore, these operations need to be performed every time the configuration of the control device or the printing apparatus is changed. Therefore, when the amount of overrun is predicted, there arises a problem of an increase in development time. In addition, a sensor or the like is required to acquire environmental conditions, media conditions, and the like. Therefore, the problem of an increase in cost also arises. In addition, due to the existence of conditions that are difficult to assume due to the influence of changes over time and unpredictable conditions such as differences between devices, it may be difficult to predict an appropriate overrun amount. Therefore, even if the overrun amount is predicted, for example, the accuracy of the prediction becomes insufficient, and there is a possibility that the stop position of the medium cannot be controlled with sufficient accuracy.

  Also, for example, as in Patent Document 2, when performing an overrun amount detection operation by actual measurement, there is a possibility that the stop position of the medium cannot be controlled with sufficient accuracy. For example, when printing is repeated, there is a possibility that the stop position cannot be controlled with sufficient accuracy due to changes in various conditions that occur while printing is repeated. For example, when a medium roll is used, the diameter of the medium roll gradually changes. For this reason, the timing at which the stop command is output cannot be appropriately corrected, and the stop position may not be controlled with sufficient accuracy.

  If the stop position cannot be controlled with sufficient accuracy, for example, problems such as dimensional deviation in a subsequent process or the like will occur. Under such circumstances, conventionally, there has been a demand for positioning a stop position of a conveyed medium with higher accuracy without being affected by environmental conditions, differences between devices, media conditions, and the like. SUMMARY An advantage of some aspects of the invention is that it provides a printing apparatus, a conveyance apparatus, and a printing method that can solve the above-described problems.

In order to solve the above problems, the present invention has the following configuration.
(Configuration 1) A printing apparatus that repeats conveyance of a medium, stop of conveyance, and printing, and controls a conveyance roller that conveys a medium on which printing is performed to a preset target position, and rotation and stop of the conveyance roller. Thus, a conveyance control unit that controls conveyance of the medium and a printing unit that performs printing on the medium conveyed to the target position. The conveyance control unit performs the next printing after the previous printing is performed by the printing unit. A command to output a rotation stop command of the conveyance roller corresponding to each of the intermediate position before the medium reaches the target position and at least two positions of the target position during the conveyance of the medium until When the command output unit outputs a stop command corresponding to the output unit and a halfway position, an overrun amount that is the amount of rotation of the transport roller from when the stop command is output until the transport roller stops is detected. When a stop command corresponding to the target position is output, the command output unit outputs the medium at a position obtained by subtracting the distance corresponding to the overrun amount detected by the overrun amount detection unit from the target position. A stop command is output at the timing reached.

  If comprised in this way, the stop position of the medium conveyed with respect to a target position can be controlled with high precision. In addition, by performing a stop operation (measurement stop operation) for detecting the amount of overrun immediately before a stop operation (positioning stop operation) for printing each time, environmental conditions, differences between devices, media conditions, etc. The timing at which the stop command corresponding to the target position should be output can be corrected by absorbing the influence of various conditions. Therefore, for example, even when various conditions change while repeating printing, the stop position can be controlled with high accuracy.

  Further, in the case of such a configuration, unlike the case where the overrun amount is predicted, a function or a table for obtaining the overrun amount from the environmental condition, the media condition, etc. is unnecessary. Therefore, development time can be shortened. In addition, since a sensor for acquiring environmental conditions, media conditions, and the like is not necessary, costs can be reduced. In addition, there is no error in the overrun amount due to the presence of unpredictable conditions.

  Note that “transporting the medium to the target position” means, for example, transporting the medium so that the printing range in which printing is performed on the medium is set to a predetermined target position. The timing when the medium reaches the position obtained by subtracting the distance corresponding to the overrun amount from the target position is, for example, that the predetermined reference position on the medium has reached the position obtained by subtracting the distance corresponding to the overrun amount from the target position. It is timing. This reference position is, for example, a position that should be adjusted to the target position in the positioning stop operation. The distance corresponding to the overrun amount is, for example, a distance that the medium is transported while the transport roller is overrun. In addition, this printing apparatus performs, for example, printing that requires alignment with a printing result in a later process or the like. Such printing is, for example, printing of one or a plurality of ink layers in overprinting.

  (Configuration 2) The command output unit outputs a stop command at a plurality of halfway positions, and the overrun detection unit detects an overrun amount corresponding to the stop command output at each halfway position. The output unit corrects the timing at which a stop command should be output corresponding to the target position based on the overrun amount detected corresponding to each of the plurality of intermediate positions. With this configuration, the stop position of the medium can be controlled with higher accuracy.

  (Configuration 3) The printing apparatus is a printing apparatus that uses a medium roll in which the medium is wound in a roll shape, the conveying roller sequentially conveys the medium from the medium roll, and the printing unit sequentially unwinds from the medium roll. Print sequentially on the printed media.

  When a media roll is used, the diameter of the media roll gradually changes while printing is repeated. Therefore, there is a possibility that the overrun amount with respect to the stop command also changes gradually. Therefore, for example, even if the overrun amount is detected only at the time of mechanical initialization of the apparatus, it is difficult to control the stop position with high accuracy.

  On the other hand, with the configuration 3, it is possible to detect the amount of overrun under various conditions immediately before printing each time. Therefore, even when a medium roll is used, the stop position of the medium can be controlled with high accuracy. Note that when the medium roll is used, the conveyance of the medium to the target position means, for example, that the medium is conveyed so that the printing range where the next printing is performed is matched with the target position.

  (Configuration 4) The overrun amount detection unit detects the overrun amount even when the command output unit outputs a stop command corresponding to the target position, and the target detected by the overrun amount detection unit at the previous printing Further, based on the overrun amount corresponding to the position, the command output unit corrects the timing at which the stop command should be output corresponding to the target position. With this configuration, the stop position of the medium can be controlled with higher accuracy.

  (Configuration 5) A conveyance device that conveys a medium in a printing apparatus that repeatedly conveys the medium, stops conveyance, and prints, and conveys the medium on which printing is performed to a preset target position; and a conveyance roller A conveyance control unit that controls the conveyance of the medium by controlling the rotation and stop of the medium, and the conveyance control unit is conveying the medium from the previous printing until the next printing is performed. In addition, a command output unit that outputs a stop command for rotation of the transport roller corresponding to each of the intermediate position before the medium reaches the target position and at least two positions of the target position, and a stop command corresponding to the intermediate position When the command output unit outputs, an overrun amount detection unit that detects an overrun amount that is the rotation amount of the transport roller from when the stop command is output until the transport roller stops is provided. When outputting a stop command corresponding to, the command output unit outputs a stop command at the timing when the medium reaches the position obtained by subtracting the distance corresponding to the overrun amount detected by the overrun amount detection unit from the target position. . If comprised in this way, the effect similar to the structure 1 can be acquired.

  (Structure 6) A printing method in which conveyance of a medium, stop of conveyance, and printing are repeated, and a medium on which printing is performed by a conveyance roller after the previous printing is performed until the next printing is performed The rotation amount of the transport roller from the stop command is output to the stop of the transport roller at a midway position before the medium reaches the preset target position. After detecting the overrun amount and restarting the conveyance of the medium, when the medium reaches the position obtained by subtracting the distance corresponding to the detected overrun amount from the target position, a command to stop the rotation of the conveyance roller is issued again. Output and print on the medium whose conveyance has been stopped. In this way, the same effect as in Configuration 1 can be obtained.

  According to the present invention, the stop position of the conveyed medium can be controlled with high accuracy in the printing apparatus.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings. FIG. 1 shows an example of the configuration of a printing apparatus 10 according to an embodiment of the present invention. The printing apparatus 10 is an ink jet printer that uses a medium roll 20 in which a medium 30 is wound in a roll shape, and repeats conveyance of the medium 30, stop of conveyance, and printing. In each printing, the printing apparatus 10 conveys the medium 30 so that the printing range is adjusted to a predetermined target position. In this example, the printing apparatus 10 includes a printing unit 112 and a conveyance unit 100.

  The printing unit 112 is an inkjet head, and performs printing sequentially on the medium 30 that is transported by the transport unit 100 and sequentially fed from the medium roll 20. The conveyance unit 100 includes a feeding roller 102, a motor 120, a take-up roller 108, a motor 122, guide rollers 104 and 106, and a conveyance control unit 114.

  The feeding roller 102 is a roller that holds the medium roll 20 on the feeding side, and rotatably holds the medium roll 20 so that the medium 30 is sequentially fed from the medium roll 20 in accordance with a force for pulling out the medium 30. The motor 120 is, for example, a motor with a torque limiter, and biases the feeding roller 102 in a direction opposite to the direction in which the medium 30 is fed out. As a result, the motor 120 applies a back tension to the medium 30 and adjusts the tension applied to the medium 30.

  The take-up roller 108 is an example of a conveyance roller, and takes up the medium 30 on the take-up side in accordance with the output of the motor 122. The motor 122 rotates the take-up roller 108 in the direction in which the medium 30 is taken up in accordance with an instruction from the conveyance control unit 114. As a result, the take-up roller 108 sequentially feeds the medium 30 from the medium roll 20 held by the feed roller 102 and transports it to the target position downstream in the transport direction. Note that a roller other than the take-up roller 108 such as the guide roller 104 or the guide roller 106 may be used as the transport roller for transporting the medium 30.

  The guide rollers 104 and 106 are rollers for guiding the conveyance of the medium 30, and are provided in the middle of the conveyance path of the medium 30. The table 110 is a table that supports the lower surface of the medium 30 to be conveyed, and is provided between the guide roller 104 and the guide roller 106 so as to face the printing unit 112 with the medium 30 interposed therebetween.

  The conveyance control unit 114 controls the rotation and stop of the winding roller 108 by controlling the output of the motor 122. Accordingly, the conveyance control unit 114 controls the conveyance of the medium 30. In this example, the transport control unit 114 includes a command output unit 202, a motor control unit 204, and an overrun amount detection unit 206.

  The command output unit 202 outputs a rotation start command and a stop command for the winding roller 108. In this example, the command output unit 202 is positioned at two positions, a predetermined halfway position of transport and a target position, during transport of the medium 30 between each printing and the next printing. At the corresponding timing, a stop command for the winding roller 108 is output. Accordingly, the transport unit 100 executes the stop operation of the medium 30 twice in the positioning sequence of the medium 30 for performing each printing (control sequence of the transport speed of the medium 30). Hereinafter, the first stop operation is referred to as a measurement stop operation, and the second stop operation is referred to as a positioning stop operation. The command output unit 202 outputs a stop command corresponding to the measurement stop operation at a timing corresponding to a predetermined midway position of conveyance. Further, a stop command corresponding to the positioning stop operation is output at a timing corresponding to the target position of conveyance.

  The motor control unit 204 rotates and stops the winding roller 108 according to the command output from the command output unit 202. The overrun amount detection unit 206 detects the overrun amount of the take-up roller 108 when the measurement stop operation is performed. The overrun amount detection unit 206 detects the overrun amount based on, for example, the output of an encoder that outputs a pulse signal in accordance with the rotation of the winding roller 108. The overrun amount detection unit 206 may detect the overrun amount based on the rotation amount of the motor 122 that drives the winding roller 108.

  Hereinafter, the use of the detected overrun amount will be described in more detail. The overrun amount detection unit 206 notifies the command output unit 202 of the detected overrun amount. Using this, the command output unit 202 corrects the timing to output the stop command in the positioning stop operation. Thereby, the command output unit 202 outputs a stop command at the timing when the medium 30 reaches the position obtained by subtracting the distance corresponding to the overrun amount detected during the measurement stop operation from the target position in the positioning stop operation. According to this example, the stop position of the conveyed medium 30 can be controlled with high accuracy with respect to the target position.

  In this example, a measurement stop operation for detecting the overrun amount is performed immediately before the positioning stop operation for performing each printing. Therefore, it is possible to determine the timing at which a stop command corresponding to the target position should be output by absorbing the influence of various conditions such as environmental conditions, differences between devices, and media conditions. In addition, this makes it possible to control the stop position with high accuracy even when various conditions change during repeated printing.

  FIG. 2 shows an example of a control sequence of the conveyance speed of the medium 30. In this example, the printing apparatus 10 conveys the medium 30 to the target position before printing each time. In addition, during the conveyance of the medium 30, two stop operations, a measurement stop operation and a positioning stop operation, are performed.

  In this sequence, the command output unit 202 first outputs a rotation start command for the winding roller 108 after the previous printing is performed. Thereby, conveyance of the medium 30 is started. Then, at a predetermined point in time when the medium 30 approaches a midway position before reaching the target position, the command output unit 202 outputs a stop command for performing a measurement stop operation. Thereby, the conveyance of the medium 30 is temporarily stopped. Further, for this measurement stop operation, the overrun amount detection unit 206 detects the overrun amount of the winding roller 108. Based on the detected overrun amount, the command output unit 202 corrects the timing at which the stop command should be output in the positioning stop operation.

  After the measurement stop operation, the command output unit 202 outputs a rotation start command for the winding roller 108 again. Thereby, the conveyance of the medium 30 is resumed. When the medium 30 approaches the target position, the command output unit 202 outputs a stop command for performing the positioning stop operation at the timing corrected by the positioning stop operation. As a result, the medium 30 stops at the target position. According to this example, the stop position of the conveyed medium 30 can be controlled with high accuracy.

  After the medium 30 stops at the target position, the printing unit 112 performs printing on the medium 30. Further, after printing, the above operation for performing the next printing is repeated.

  Here, the overrun amount detection unit 206 may detect the overrun amount even with respect to the positioning stop operation. In this case, the command output unit 202 corrects the timing at which the stop command should be output in the next positioning stop operation based on, for example, the overrun amount with respect to the positioning stop operation at the previous printing. In this way, the stop position of the conveyed medium 30 can be controlled with higher accuracy.

  FIG. 3 shows a modification of the control sequence of the conveyance speed of the medium 30. In this example, the printing apparatus 10 performs the measurement stop operation twice. Except as described below, the sequence shown in FIG. 3 is the same as or similar to the sequence shown in FIG.

  In this sequence, the command output unit 202 outputs a stop command for performing a measurement stop operation at two intermediate positions. The overrun amount detection unit 206 detects the overrun amount for each measurement stop operation. The command output unit 202 corrects the timing to output the stop command in the positioning stop operation based on the overrun amount detected for the two measurement stop operations. According to this example, the stop position of the conveyed medium 30 can be controlled with higher accuracy.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

  The present invention can be suitably used for a printing apparatus, for example.

1 is a diagram illustrating an example of a configuration of a printing apparatus 10 according to an embodiment of the present invention. FIG. 6 is a diagram illustrating an example of a control sequence of a conveyance speed of a medium 30. FIG. 10 is a diagram illustrating a modification of the control sequence of the conveyance speed of the medium 30.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 20 ... Medium roll, 30 ... Medium, 100 ... Conveyance part 100, 102 ... Feeding roller, 104 ... Guide roller, 106 ... Guide roller, 108 ... take-up roller (conveyance roller), 110 ... table, 112 ... printing unit, 114 ... conveyance control unit, 120 ... motor, 122 ... motor, 202 ... command output , 204... Motor control unit, 206... Overrun amount detection unit

Claims (6)

A printing apparatus that repeats conveyance of a medium, stop of conveyance, and printing,
A transport roller for transporting the medium to be printed to a preset target position;
A conveyance control unit that controls conveyance of the medium by controlling rotation and stop of the conveyance roller;
A printing unit that performs printing on the medium conveyed to the target position;
The conveyance control unit
During the conveyance of the medium between the time when the printing unit performs the previous printing and the time when the next printing is performed, a command to stop the rotation of the conveyance roller is issued before the medium reaches the target position. A command output unit for outputting corresponding to each of the position and at least two positions of the target position;
When the command output unit outputs the stop command corresponding to the halfway position, an overrun amount that is a rotation amount of the transport roller from when the stop command is output until the transport roller stops is detected. With an overrun amount detector,
When outputting the stop command corresponding to the target position, the command output unit causes the medium to reach a position obtained by subtracting a distance corresponding to the overrun amount detected by the overrun amount detection unit from the target position. The printing apparatus is characterized in that the stop command is output at the timing. The command output unit outputs the stop command at a plurality of the intermediate positions,
The overrun detection unit detects the overrun amount in response to the stop command output at each of the intermediate positions,
The command output unit corrects the timing at which the stop command should be output corresponding to the target position based on the overrun amount detected corresponding to each of the plurality of intermediate positions. The printing apparatus according to claim 1. The printing apparatus is a printing apparatus that uses a medium roll in which the medium is wound into a roll,
The transport roller sequentially feeds and transports the medium from the medium roll,
The printing apparatus according to claim 1, wherein the printing unit sequentially performs printing on the medium sequentially fed from the medium roll. The overrun amount detection unit detects the overrun amount even when the command output unit outputs the stop command corresponding to the target position,
Based on the overrun amount corresponding to the target position detected by the overrun amount detection unit at the time of the previous printing, the command output unit corrects the timing at which the stop command should be output corresponding to the target position. The printing apparatus according to claim 1, wherein the printing apparatus is a printing apparatus. A transport device that transports the medium in a printing apparatus that repeats transport of the medium, stop of transport, and printing,
A transport roller for transporting the medium to be printed to a preset target position;
A conveyance control unit that controls conveyance of the medium by controlling rotation and stop of the conveyance roller;
The conveyance control unit
During the conveyance of the medium from the previous printing to the next printing, a command to stop the rotation of the conveyance roller, a midway position before the medium reaches the target position, and the A command output unit for outputting corresponding to each of at least two positions of the target position;
When the command output unit outputs the stop command corresponding to the halfway position, an overrun amount that is a rotation amount of the transport roller from when the stop command is output until the transport roller stops is detected. With an overrun amount detector,
When outputting the stop command corresponding to the target position, the command output unit causes the medium to reach a position obtained by subtracting a distance corresponding to the overrun amount detected by the overrun amount detection unit from the target position. The stop device outputs the stop command at the timing. A printing method for repeating conveyance of a medium, stopping conveyance, and printing,
Between the time when the previous printing is performed and the time when the next printing is performed, the conveyance roller conveys the medium on which printing is performed,
At a midway position before the medium reaches a preset target position, a rotation stop command for the transport roller is output,
Detecting the amount of overrun that is the amount of rotation of the transport roller from when the stop command is output until the transport roller stops;
After restarting the conveyance of the medium, at the timing when the medium reaches a position obtained by subtracting a distance corresponding to the detected amount of overrun from the target position, an instruction to stop the rotation of the conveyance roller is output again.
A printing method comprising printing on the medium whose conveyance has been stopped.

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