JP4716430B2 - Printing apparatus, conveying apparatus, and printing method - Google Patents

Description

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

  2. Description of the Related Art Conventionally, as a printing apparatus that prints a thin medium such as a film, an ink jet printer that uses a medium wound in a roll shape is known (for example, see Non-Patent Document 1). In such an ink jet printer, when printing is performed by operating an ink jet head, the medium is unwound, wound, and conveyed.

Conventionally, there has been known an ink jet image forming apparatus including a suction fan that sucks a print medium from a lower part of a platen, and a variable control unit that variably controls the suction force of the suction fan (Patent Document 1). In this image forming apparatus, for the purpose of reducing the load on the transport motor, reducing power consumption, noise, and the like, the suction force of the suction fan is used as the first suction force during one-band printing by operating the head, and the subsequent transport of the print medium is performed. Sometimes the second suction force is smaller than the first suction force.
Internet (URL: http://www.mimaki.co.jp/) No. 00/034049

  In an ink jet printer using a medium wound in a roll shape, when printing is performed by moving the ink jet head with respect to a thin medium such as a film, it is necessary to fix the medium. As a method of fixing the medium, for example, a method of pressing both ends of the printing range of the medium with rollers used for conveying the medium is conceivable. However, when printing on a thin medium such as a film, the medium may be wrinkled due to an operation for fixing the medium only by pressing both ends of the printing range. If the medium is wrinkled, an accurate print result cannot be obtained.

  Further, as a method of fixing the medium, a method of adsorbing and fixing the medium on a table or the like is also conceivable. However, also in this case, wrinkles may occur in the medium due to adsorption to a thin medium such as a film. If wrinkles occur in the medium, an accurate printing result cannot be obtained in this case as well. Therefore, conventionally, a method for appropriately fixing a medium without generating wrinkles has been demanded.

  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 using a medium roll in which the medium is wound in a roll shape, wherein the medium roll is rotatably held so that the medium is sequentially discharged from the medium roll in accordance with a pulling force of the medium. A roller, a printing unit that performs printing on the medium fed from the medium roll, a table that is provided at a position facing the printing unit across the medium, and that fixes the medium printed by the printing unit by suction, and a printing unit A take-up roller that winds up the medium printed by the control unit, and a transport control unit that controls a transport speed of the medium transported from the feed roller to the take-up roller. The transport control unit has a first transport speed. The transport speed of the medium is controlled so as to repeat the speed switching operation for sequentially switching the transport, the transport at the second transport speed lower than the first transport speed, and the stop of the transport. When the medium is being transported at the second transport speed, the table sucks the medium at a preset first degree of vacuum, and when the transport of the medium is stopped, the table has the first degree of vacuum. By sucking the medium at a higher second degree of vacuum, the medium is fixed by suction, and the printing unit performs printing on the medium fixed by suction on the table.

  In such a configuration, the medium is transported at the second transport speed at a low speed while being sucked at the first vacuum degree with a low degree of vacuum immediately before fixing by suction. In this case, the suction force from the table and the tension for conveyance (pulling force) are simultaneously applied to the medium, and for example, it becomes easier to release the wrinkles of the medium as compared with the case where only the tension for conveyance is applied to the medium. For this reason, even if wrinkles are temporarily generated in the medium during conveyance or the start of suction, the wrinkles can be appropriately released.

  In addition, the conveyance is stopped in a state in which the wrinkles are released, and the suction is started at the second vacuum degree with a higher degree of vacuum, for example, the conveyance is stopped without interposing the low-speed conveyance. The generation of wrinkles in the medium can be suppressed compared to the case where vacuum suction is performed. Therefore, with the configuration 1, even when a thin medium such as a film is used, wrinkles can be prevented from occurring due to the operation for fixing the medium. In addition, it is possible to provide a printing apparatus including a medium suction mechanism and a wrinkle release mechanism.

  For example, when the conveyance at low speed is not performed, for example, even if the suction is performed at a low degree of vacuum while the conveyance is stopped, it is difficult to release the wrinkles. For example, when suction is performed at a low degree of vacuum while carrying at high speed, there is a concern that scratches may occur due to the medium rubbing on the table at high speed. Further, for example, when high-speed conveyance is not performed and only low-speed conveyance and conveyance stop are repeated, printing efficiency is greatly reduced due to a decrease in conveyance speed. On the other hand, with the configuration 1, the wrinkles can be appropriately released without greatly reducing the printing efficiency.

  (Configuration 2) When the medium is transported at the first transport speed, the table does not suck the medium. If comprised in this way, a medium can be conveyed efficiently except just before fixing by adsorption | suction. In addition to the case where the table does not suck the medium at all, it includes a case where the table is not substantially sucked, for example, a case where the suction is performed so as not to affect the conveyance of the medium.

  (Configuration 3) A drive unit that rotates the take-up roller in the direction of winding the medium and a biasing unit that biases the feed roller in a direction opposite to the direction of feeding the medium are further provided, and the medium has a first transport speed. In this case, the conveyance control unit adjusts the outputs of the driving unit and the urging unit so that the preset first tension is applied to the medium. The conveyance control unit preferably adjusts the outputs of the driving unit and the urging unit so that the medium is tensioned during both conveyance and stoppage.

  (Configuration 4) A transport device that transports a medium in a printing apparatus that uses a medium roll in which the medium is wound into a roll, and the medium roll is configured so that the medium is sequentially fed out from the medium roll in accordance with a pulling force of the medium. A feed roller that holds the print medium rotatably, a table that fixes the medium to be printed by suction, a take-up roller that winds up the printed medium, and a transport of the medium that is transported from the feed roller to the take-up roller A transport control unit that controls the speed, and the transport control unit performs transport at the first transport speed, transport at a second transport speed lower than the first transport speed, and stop of the transport. When the medium transport speed is controlled so as to repeat the speed switching operation for switching in order, and the medium is transported at the second transport speed, the table stores the medium at the preset first degree of vacuum. And arguments, if the conveyance of the medium is stopped, the table, by sucking the medium at a higher than the first degree of vacuum second vacuum, to fix the adsorbing medium. If comprised in this way, the effect similar to the structure 1 can be acquired.

  (Structure 5) A printing method using a medium roll in which the medium is wound into a roll, and the medium roll can be rotated by a feeding roller so that the medium is sequentially fed out from the medium roll in accordance with a pulling force of the medium. Holding and repeating the speed switching operation for sequentially switching between the transport at the first transport speed, the transport at the second transport speed lower than the first transport speed, and the stop of the transport. While controlling the conveyance speed, the medium is conveyed, and the first preset by a table provided at a position facing the printing unit with the medium sandwiched at the timing when the medium is conveyed at the second conveyance speed. At a timing when the medium is sucked at a vacuum degree and the conveyance of the medium is stopped, the medium is sucked at a second vacuum degree higher than the first vacuum degree by the table, and the medium is fixed by suction. Depending on the printing department Buru to perform printing on fixed media by adsorption, taken up by the take-up roller to medium that has been printed. In this way, the same effect as in Configuration 1 can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, in a printing apparatus using the medium roll by which the medium was wound up in roll shape, generation | occurrence | production of wrinkles can be suppressed and a medium can be fixed appropriately.

  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 printing apparatus that uses a medium roll 20 in which a medium 30 such as a thin film or paper is wound in a roll shape, and includes a printing unit 112 and a transport unit 100. The printing unit 112 is an inkjet head, and performs printing on the medium 30 conveyed from the medium roll 20 by the conveyance unit 100.

  The transport unit 100 is a transport device for transporting the medium 30 and transports the medium 30 while repeating transport and transport stop. In this example, the transport unit 100 includes a feeding roller 102, a motor 120, a tension controller 124, driven rollers 104 and 106, a table 110, a take-up roller 108, a motor 122, and a transport control unit 114. The transport unit 100 may further include a roller or the like for pressing and extending the medium 30.

  The feeding roller 102 is a roller that holds the medium roll 20, and rotatably holds the medium roll 20 so that the medium 30 is sequentially fed out from the medium roll 20 according to the force with which the medium 30 is pulled out. The motor 120 is an example of an urging unit and urges the feeding roller 102 in a direction opposite to the direction in which the medium 30 is fed in accordance with the output of the conveyance control unit 114. Accordingly, the motor 120 adjusts the tension applied to the medium 30 by applying reverse tension. The tension controller 124 is a torque limiter that limits the torque received by the feeding roller, and limits the tension applied to the medium 30 in accordance with an instruction from the conveyance control unit 114.

  The driven rollers 104 and 106 are rollers for guiding the conveyance of the medium 30. The driven rollers 104 and 106 are respectively provided downstream of the feeding roller 102 in the transport direction of the medium 30 and rotate according to the movement of the transported medium 30.

  The table 110 is a suction fixing stage that supports the lower surface of the medium 30 to be conveyed, and is provided between the driven roller 104 and the driven roller 106 so as to face the printing unit 112 with the medium 30 interposed therebetween. Further, the table 110 sucks the medium 30 at a vacuum level set by the transport control unit 114. Then, the medium 30 is fixed by suction at the timing when the conveyance is temporarily stopped. Note that after the medium 30 is fixed by suction, the printing unit 112 performs printing on the fixed medium 30.

  The take-up roller 108 is a roller that takes up the medium 30 printed by the printing unit 112, and is provided downstream in the transport direction with respect to the driven roller 106. The motor 122 is an example of a drive unit, and rotates the take-up roller 108 in the direction in which the medium 30 is taken up in accordance with the output of 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 in the transport direction.

  The conveyance control unit 114 controls the conveyance speed of the medium 30 that is conveyed from the feeding roller 102 to the take-up roller 108. In addition, the conveyance control unit 114 controls the suction and release of the medium 30 by the table 110, and the degree of vacuum that the table 110 sucks the medium 30 during conveyance and when the conveyance is stopped (hereinafter, the degree of vacuum of the table 110). Adjust). In this example, the conveyance control unit 114 changes the degree of vacuum of the table 110 according to the conveyance speed of the medium 30. Further, in this example, the conveyance control unit 114 adjusts the tension applied to the medium 30 by adjusting the output of the tension controller 124.

FIG. 2 shows an example of control of the transport control unit 114 with respect to the transport speed of the medium 30 and the degree of vacuum of the table 110. In this example, the conveyance control unit 114 controls the conveyance speed of the medium 30 so as to repeat the speed switching operation for sequentially switching the speed in a constant sequence. The first period T1 of the speed changing operation, the conveyance control unit 114, the conveying speed is set to high speed of the conveying speed (first conveying speed) v _1. Then, in the next period T2, the conveying speed is set to v ₂ (conveying speed of the second) slower transport speed. In the last period T3, the conveyance speed is set to 0 and the conveyance is stopped. Incidentally, the conveying speed _{v 2} of the low speed is about 1/10 of fast transport speed _{v 1} (e.g., about 1 / 20-1 / 5).

Moreover, the conveyance control part 114 changes the vacuum degree of the table 110 according to the timing which changes conveyance speed. For example, in the period T1 where the medium 30 is transported at a high conveying speed v _1, the transport control unit 114 sets the degree of vacuum table 110 to atmospheric pressure. In this case, the table 110 does not suck the medium. Therefore, high-speed conveyance can be appropriately performed in the period T1.

Further, in the period T2 in which the medium 30 is transported at a slower conveying speed v _2, the conveyance control unit 114, the degree of vacuum table 110, preset fine vacuum vacuum P _{1 (first} degree of vacuum, For example, a negative pressure of about 0.2 to 0.4 kPa) is set. In this case, the table 110 sucks the medium 30 at a vacuum degree P ₁ of a fine vacuum. Thereby, in the period T2, the medium 30 can be extended and wrinkles can be released.

In addition, during the period T3 in which the conveyance of the medium 30 is stopped, the conveyance control unit 114 sets the vacuum degree of the table 110 to the vacuum degree P ₂ (second vacuum degree, for example, a negative pressure of about 5 to 10 kPa). ). In this case, the table 110, to suck the medium 30 at a vacuum degree _{P 2} strong vacuum. Thereby, in the period T3, the medium 30 can be appropriately fixed by suction. This also prevents the medium 30 from being displaced during printing, and an accurate printing result can be obtained.

  In the above control, when the vacuum rate is increased by lowering the transport speed, such as the transition from the period T1 to T2 or the transition from the period T2 to T3, the transport speed is decreased first and the transport speed is decreased. It is preferable to raise the degree of vacuum later. For example, when lowering the degree of vacuum by increasing the conveyance speed as in the transition from the period T3 to the next period T1, it is preferable to lower the degree of vacuum first and increase the conveyance speed after the degree of vacuum has decreased. In this way, the generation of wrinkles can be prevented more appropriately.

  FIG. 3 shows an example of control of the conveyance control unit 114 with respect to the tension applied to the medium 30. The conveyance control unit 114 controls the tension of the medium 30 by keeping the output of the motor 120 constant and adjusting the output of the tension controller 124.

  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 control of the transport control unit 114 with respect to the transport speed of the medium 30 and the degree of vacuum of the table 110. FIG. 4 is a diagram illustrating an example of control of a conveyance control unit 114 with respect to a tension applied to a medium 30.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printing apparatus, 20 ... Medium roll, 30 ... Medium, 100 ... Conveying part, 102 ... Feeding roller, 104 ... Driven roller, 106 ... Driven roller, 108. ..Take-up roller, 110 ... Table, 112 ... Printing unit, 114 ... Conveyance control unit, 120 ... Motor, 122 ... Motor, 124 ... Tension controller

Claims (5)

A printing apparatus using a medium roll in which a medium is wound into a roll,
A feeding roller that rotatably holds the medium roll so that the medium is sequentially fed from the medium roll in accordance with a force for pulling out the medium;
A printing unit that performs printing on the medium fed from the medium roll;
A table that is provided at a position facing the printing unit across the medium, and that fixes the medium printed by the printing unit by suction;
A winding roller that winds up the medium printed by the printing unit;
A conveyance control unit that controls the conveyance speed of the medium conveyed from the feeding roller to the take-up roller;
The transport control unit repeats a speed switching operation for sequentially switching transport at the first transport speed, transport at a second transport speed lower than the first transport speed, and stop of transport. And controlling the transport speed of the medium,
When the medium is being transported at the second transport speed, the table sucks the medium at a preset first degree of vacuum,
When the conveyance of the medium is stopped, the table fixes the medium by suction by sucking the medium at a second degree of vacuum higher than the first degree of vacuum,
The printing apparatus, wherein the printing unit performs printing on the medium fixed to the table by suction.   The printing apparatus according to claim 1, wherein the table does not suck the medium when the medium is transported at the first transport speed. A drive unit that rotates the take-up roller in the direction of taking up the medium;
An urging portion that urges the feeding roller in a direction opposite to the direction of feeding out the medium;
When the medium is transported at the first transport speed, the transport control unit adjusts the outputs of the driving unit and the urging unit so that a preset tension is applied to the medium. The printing apparatus according to claim 1, wherein the printing apparatus is a printer. A transport device for transporting the medium in a printing apparatus using a medium roll in which the medium is wound into a roll,
A feeding roller that rotatably holds the medium roll so that the medium is sequentially fed from the medium roll in accordance with a force for pulling out the medium;
A table for fixing the medium to be printed by suction;
A take-up roller for taking up the printed medium;
A conveyance control unit that controls the conveyance speed of the medium conveyed from the feeding roller to the take-up roller;
The transport control unit repeats a speed switching operation for sequentially switching transport at the first transport speed, transport at a second transport speed lower than the first transport speed, and stop of transport. And controlling the transport speed of the medium,
When the medium is being transported at the second transport speed, the table sucks the medium at a preset first degree of vacuum,
When the conveyance of the medium is stopped, the table fixes the medium by suction by sucking the medium at a second degree of vacuum higher than the first degree of vacuum. Conveying device. A printing method using a medium roll in which the medium is wound into a roll,
The medium roll is rotatably held on a feeding roller so that the medium is sequentially fed out from the medium roll according to a force for pulling out the medium,
Transport of the medium so as to repeat a speed switching operation for sequentially switching between transport at the first transport speed, transport at a second transport speed lower than the first transport speed, and stop of transport. Conveying the medium while controlling the speed,
At a timing when the medium is conveyed at the second conveyance speed, the medium is sucked at a preset first degree of vacuum by a table provided at a position facing the printing unit with the medium interposed therebetween. ,
At the timing when the conveyance of the medium is stopped, the medium is sucked by the table at a second vacuum level higher than the first vacuum level, and the medium is fixed by suction,
The printing unit performs printing on the medium fixed to the table by suction,
A printing method characterized by winding the printed medium on a winding roller.

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