JP2011051250A - Printing method and printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing method and a printing device that easily and surely prevent a flipping phenomenon of the rear end of a recording medium. <P>SOLUTION: The printing method has: a transfer step for transferring a recording medium (P) by holding the recording medium between a first roller (133) and a second roller (134) biased toward the first roller; a printing step for printing on the transferred recording medium; and a rear-end guiding step for guiding the rear end (PE) of the recording medium by defining the interval between the first roller and the second roller to an interval (G) equivalent to the thickness (T) of the recording medium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  2. Description of the Related Art Conventionally, there is known a printing apparatus that obtains a high-quality image by reducing the influence of the flipping phenomenon at the trailing edge of the paper in the clamping portion between the paper feed roller and the pressure roller on the image quality (for example, Patent Document 1). reference). Further, there is known a printing apparatus that receives a force from the roller when the rear end portion of the recording material is separated from the pinch roller, and prevents a decrease in the conveyance accuracy of the recording material after the separation from the roller ( For example, see Patent Document 1).

Japanese Patent Laid-Open No. 9-272236 Japanese Patent Laid-Open No. 10-26851

  However, the conventional printing apparatus suppresses the phenomenon of the trailing edge of the recording medium by controlling the pressure for sandwiching the recording medium such as recording paper, but it is difficult to control the pressure for sandwiching the recording medium. is there. Also, depending on the pressure control, there is a problem that it is difficult to surely prevent the phenomenon of flipping the trailing edge of the recording medium.

  Therefore, the present invention provides a printing method and a printing apparatus that can easily and reliably prevent a trailing edge phenomenon of a recording medium.

In order to solve the above-described problem, the printing method of the present invention includes a conveyance step of nipping and conveying a recording medium between a first roller and a second roller biased toward the first roller; A printing process for performing a printing process on the conveyed recording medium, and a gap between the first roller and the second roller is defined as an interval corresponding to the thickness of the recording medium to guide the rear end of the recording medium And a rear end guide step.
By printing in this way, when the leading edge of the recording medium reaches between the first roller and the second roller in the transport process, the recording medium is sandwiched between the first roller and the second roller, and in the transport direction. Be transported. The conveyed recording medium is subjected to a printing process in a printing process. At this time, a biasing force acts on the second roller toward the first roller, and the recording medium is sandwiched between the first roller and the second roller by the biasing force. For this reason, when a force that pulls the leading end side of the recording medium that has passed between the first roller and the second roller to the front in the transport direction is applied, the recording medium is in a state where tension is applied.
However, when the interval between the first roller and the second roller is defined as an interval corresponding to the thickness of the recording medium in the rear end guide step, the second roller is biased toward the first roller by the interval. It becomes a released state. As a result, the second roller is merely disposed near the surface of the recording medium, and even if a force that pulls the leading end side of the recording medium forward in the conveying direction is applied, the tension is hardly applied to the recording medium. . In this state, when the trailing edge of the recording medium reaches between the first roller and the second roller, the trailing edge of the recording medium is not affected by the tension, and the first roller and the second roller face the front side and the back side. It passes between the first roller and the second roller while being guided by the roller.
Therefore, according to the present invention, it is not necessary to control the pressure for pinching the recording medium, and the flipping phenomenon in which the rear end of the recording medium is flipped can be easily and reliably prevented.

In addition, the printing method of the present invention is characterized by having a rear end detection step of detecting a rear end of the recording medium before the rear end guide step.
In this way, the trailing edge guide process can be started at an appropriate timing according to the position of the trailing edge of the recording medium.

The printing method of the present invention is characterized in that the trailing edge guide step is executed immediately before the trailing edge of the recording medium passes between the first roller and the second roller.
By doing so, the recording medium is sandwiched between the first roller and the second roller until the rear end of the recording medium passes between the first roller and the second roller, and is appropriate for the recording medium. It is possible to apply a proper tension.

In addition, the printing method of the present invention includes a thickness detection step of detecting the thickness of the recording medium before the trailing edge guide step.
By doing in this way, the space | interval of the 1st roller in a back end guide process and a 2nd roller can be determined according to the thickness of the recording medium detected in the thickness detection process.

Further, the printing apparatus of the present invention includes a transport unit that sandwiches and transports a recording medium between the first roller and the second roller that is biased toward the first roller, and the transported recording medium. A printing unit that performs a printing process, a support unit that supports the second roller and biases the first roller, and defines the position of the support unit, and the first roller and the second roller. And a drive unit that regulates the interval to an interval corresponding to the thickness of the recording medium.
With this configuration, when the leading edge of the recording medium reaches between the first roller and the second roller of the transport unit, the recording medium is sandwiched between the first roller and the second roller, and is moved in the transport direction. Be transported. The transported recording medium is subjected to printing processing from the front end side in the printing unit. At this time, the support unit biases the second roller toward the first roller, and the recording medium is sandwiched between the first roller and the second roller by the biasing force. For this reason, when a force that pulls the leading end side of the recording medium that has passed between the first roller and the second roller to the front in the transport direction is applied, the recording medium is in a state where tension is applied.
However, if the distance between the first roller and the second roller is defined as an interval corresponding to the thickness of the recording medium by driving the drive unit and defining the position of the support unit, the second roller Only the urging toward the first roller is released. Then, the second roller is merely disposed near the surface of the recording medium, and even if a force that pulls the front end side of the recording medium forward in the conveying direction is applied, the tension is hardly applied to the recording medium. . In this state, when the trailing edge of the recording medium reaches between the first roller and the second roller, the trailing edge of the recording medium is not affected by the tension, and the first roller and the second roller face the front side and the back side. It passes between the first roller and the second roller while being guided by the roller.
Therefore, according to the present invention, it is not necessary to control the pressure for pinching the recording medium, and the flipping phenomenon in which the rear end of the recording medium is flipped can be easily and reliably prevented.

In the printing apparatus according to the aspect of the invention, the driving unit may be provided so as to rotate integrally with the rotation shaft, a motor provided to rotate the rotation shaft at a predetermined angle, and contact with the support portion. And a cam for defining the position of the support portion.
With this configuration, the rotation shaft of the motor is rotated by a predetermined angle, and the position of the support portion is defined by the cam, so that the interval between the first roller and the second roller corresponds to the thickness of the recording medium. The interval can be specified.

Further, the printing apparatus of the present invention includes a rear end detection unit that detects a rear end of the recording medium.
With this configuration, the driving unit can be driven at an appropriate timing according to the position of the rear end of the recording medium.

Moreover, the printing apparatus of the present invention includes a thickness detection unit that detects the thickness of the recording medium.
With this configuration, the drive unit is driven to define the position of the support unit according to the thickness of the recording medium detected by the thickness detection unit, so that the distance between the first roller and the second roller is determined. Can be defined as an interval corresponding to the thickness of the recording medium.

1 is a perspective view of an ink jet printer in an embodiment of the present invention. It is sectional drawing which shows schematic structure of the inkjet printer of FIG. It is an enlarged view of the vicinity of the conveyance roller and driven roller of FIG. It is an enlarged view of the vicinity of the conveyance roller and driven roller of FIG. It is an enlarged view of the vicinity of the conveyance roller and driven roller of FIG. It is an enlarged view of the vicinity of the conveyance roller and driven roller of FIG.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a perspective view of an ink jet printer (printing apparatus) 1 according to the present embodiment.
The ink jet printer 1 shown in FIG. 1 is a cut paper (recording medium) having a relatively large paper size of, for example, JIS standard A4 size to A2 size, or roll paper (recording medium) in which the recording paper is wound in a roll shape. It is a desktop large-sized printer that prints images and characters on the same.

  The inkjet printer 1 includes a housing 2 that is a housing that covers the internal structure. A window portion 3 is provided on the upper surface of the housing 2. The window 3 is an opening for performing maintenance of the internal mechanism of the ink jet printer 1 and is covered with a window cover 4 that can be opened and closed. On both sides of the front surface of the housing 2, cartridge housing portions 5 and 5 are provided. The cartridge storage unit 5 stores a plurality of ink cartridges therein. The cartridge accommodating portion 5 is provided so as to be openable and closable so that the internal ink cartridge can be individually replaced.

  An operation unit 6 is provided on the upper right side of the front surface of the housing 2. The operation unit 6 is provided with a power button used to turn on / off the power, various operation buttons for cueing and discharging paper, flushing ink, a display unit for displaying the status of the ink jet printer, and the like. ing. A tank accommodating portion 7 is provided at the lower right side of the front surface of the housing 2. Inside the tank accommodating portion 7 is accommodated a waste liquid tank that accommodates ink distributed when the droplet discharge head is cleaned or the ink cartridge is replaced. The tank accommodating portion 7 is provided so as to be openable and closable so that the inside of the waste liquid tank can be cleaned.

  A paper feed unit 8 is provided at the upper part of the back surface of the housing 2. The paper supply unit 8 is provided so as to protrude to the upper rear side of the housing 2 and includes a roll paper holder 8a (see FIG. 2) that rotatably supports the roll paper. A paper feeding window 9 covered with a cover 10 is provided on the front side of the paper feeding unit 8. The cover 10 is provided so as to be openable and closable. By opening the cover 10, the roll paper can be attached to or detached from the roll paper holder 8 a inside the paper supply unit 8 through the paper supply window 9. . The front surface of the paper supply unit 8 and the cover 10 serve as a paper supply guide surface for guiding the paper when the cut paper is supplied manually.

In the lower center of the front surface of the housing 2, a paper supply / discharge section 11 is provided. A paper supply / discharge tray 12 is detachably attached to the paper supply / discharge unit 11. The paper supply / discharge unit 11 can manually feed thick cut paper that cannot be bent during paper supply.
The paper supply / discharge tray 12 is provided so as to protrude to the front of the paper supply / discharge unit 11, and accommodates cut sheets stacked before printing, and places cut paper and roll paper after printing on the upper surface. Can be done.

FIG. 2 is a cross-sectional view illustrating a schematic configuration inside the inkjet printer 1.
As illustrated in FIG. 2, the inkjet printer 1 includes a paper supply / discharge unit 11, a transport unit 13, and a printing unit 14.

The paper supply / discharge unit 11 includes a hopper 111 for replenishing cut paper, a paper feed roller 112 for feeding cut paper, a separating member 113 for separating overlapping cut paper, and the like.
The hopper 111 has one end 111 a positioned near the paper feed tray 121 below the paper feed / discharge tray 12 and is provided in a flat plate shape on which cut paper fed from the paper feed tray 121 can be placed. The other end side 111b of the hopper 111 is located in the vicinity of the separation member 113 and the paper feed roller 112, and is provided so as to be swingable so as to approach and separate from the paper feed roller 112 with the one end side 111a as a fulcrum. Further, the other end 111b of the hopper 111 is biased in a direction approaching the paper feed roller 112 by an elastic member such as a compression spring 111c.

The paper feed roller 112 is formed in a D shape in a cross-sectional view having a flat surface on a part of a cylindrical surface, and can rotate to intermittently convey the cut paper placed on the hopper 111 by friction. It can be done.
On the upper surface of the separation member 113, a high friction surface 113a that holds a cut sheet by friction is formed. The separation member 113 holds the lower cut sheet on the high friction surface 113a and feeds only the upper cut sheet when a plurality of cut sheets are fed up and down by the paper feed roller 112. So as to be separated.

  The transport unit 13 includes a sub roller 131 and driven rollers 132a, 132b, and 132c that transport recording paper, a transport roller (first roller) 133 and a driven roller (second roller) 134, a paper discharge roller 135 and a serrated roller 136, and recording. It has a detection sensor that detects paper.

  The sub-roller 131 sandwiches the cut paper fed by the paper feeding roller 112 between the plurality of driven rollers 132a, 132b, 132c, conveys the cut paper along the rotation direction by friction, and feeds the cut paper to the transport roller 133 It is supposed to be. When printing is performed using roll paper, the sub-roller 131 feeds the roll paper fed from the paper feed unit 8 to the transport roller 133 while being sandwiched between the driven roller 132c. It has become.

The transport roller 133 feeds these recording papers to the printing unit 14 by rotating the cut paper or roll paper fed by the sub-roller 131 while sandwiching it between the driven roller 134. Yes.
The paper discharge roller 135 rotates the recording paper fed by the transport roller 133 and passing through the printing unit 14 while sandwiching the recording paper between the paper discharge roller 135 and the paper discharge tray 136. 122 is discharged.

The printing unit 14 includes a droplet discharge head 141 that discharges ink droplets, a carriage 142 that holds the droplet discharge head 141, a platen 143 that supports recording paper, and the like.
The droplet discharge head 141 is provided corresponding to each color ink supplied from the ink cartridge, and can discharge ink droplets from a plurality of nozzles (not shown).
The carriage 142 can be reciprocated by a driving device (not shown) while holding a plurality of droplet discharge heads 141 corresponding to the inks of the respective colors.

Next, the conveyance roller 133 and the driven roller 134 of this embodiment will be described in more detail.
FIG. 3 is an enlarged view of the vicinity of the transport roller 133 and the driven roller 134 of the present embodiment.
As shown in FIG. 3, the transport roller 133 and the driven roller 134 are arranged adjacent to each other in the vertical direction so as to sandwich the recording medium. The driven roller 134 is rotatably supported by a driven roller holder (supporting portion) 137, and an interval between the driven roller 134 and the transport roller 133 is defined by the driving portion 15.

  The driven roller holder 137 has a predetermined length in the recording paper conveyance direction, and supports the driven roller 134 on one end side 137a thereof. The driven roller holder 137 is rotatably provided with a support shaft 137c provided at the center as a fulcrum, so that the driven roller 134 held on one end side 137a can be moved closer to and away from the transport roller 133 by rotating. It has become. One end side 137a of the driven roller holder 137 is urged toward the transport roller 133 by an elastic member (not shown). As a result, the driven roller 134 is biased toward the transport roller 133. The other end 137 b of the driven roller holder 137 is provided so as to be in contact with the cam 151 of the drive unit 15.

The drive unit 15 includes a motor and a control unit (not shown), and a cam 151 that is fixed to a rotation shaft that is rotationally driven by the motor and rotates integrally with the rotation shaft.
The cam 151 includes a protrusion 151 a that defines the position of the driven roller holder 137. The protrusion 151 a abuts on the upper surface of the other end 137 b of the driven roller holder 137 by the clockwise rotation of the cam 151 in the figure, and defines the position of the driven roller 134 supported by the one end 137 a of the driven roller holder 137. It is like that.

A trailing edge detection unit 16 that detects the trailing edge of the recording sheet is provided upstream of the conveying roller 133 in the recording sheet conveying direction. The trailing edge detection unit 16 is, for example, an optical sensor that detects the trailing edge of the recording paper.
The driven roller holder 137 is provided with a thickness detector 17 that detects the thickness of the recording paper. The thickness detector 17 includes an arm 171 fixed to the other end 137 b of the driven roller holder 137, a displacement sensor 172 that measures the displacement of the arm 171, and the thickness of the recording paper from the displacement of the arm 171. A calculation unit (not shown) for calculation. The displacement sensor 172 is fixed to, for example, a housing via a fixing member 173.

  A control unit (not shown) of the ink jet printer 1 drives a motor (not shown) of the drive unit 15 according to the thickness of the recording paper to rotate the rotation shaft by a predetermined angle in a rear end guide process described later. Then, the cam 151 fixed to the rotation shaft is rotated, the protrusion 151a and the driven roller holder 137 are brought into contact with each other, and the position of the driven roller 134 is defined, so that the gap between the transport roller 133 and the driven roller 134 is reached. The interval is defined as an interval corresponding to the thickness of the recording paper. The control unit (not shown) includes a storage unit in which the thickness according to the standard of the recording paper is recorded, and a calculation unit that compares the thickness of the recording paper measured by the thickness detection unit 17 with the thickness according to the standard of the recording paper. It has.

A printing method for printing characters and images on cut paper using the inkjet printer 1 having the above configuration will be described.
Prior to printing, information such as the thickness and size of the paper to be printed is input to the inkjet printer 1 in advance, and the information is recorded in the storage unit. Further, a bundle of cut sheets stored in the paper feed tray 121 below the paper feed / discharge tray 12 mounted on the paper feed / discharge section 11 shown in FIG. 2 is placed on the hopper 111.

When printing is performed, the outermost cut sheet is separated from the bundle of cut sheets on the hopper 111 by the friction caused by the rotation of the paper feed roller 112 and the friction of the separating member 113, and the gap between the sub roller 131 and the driven roller 132 a. To be sent to.
The cut sheet fed between the sub roller 131 and the driven roller 132a is sandwiched between the sub roller 131 and a plurality of driven rollers 132a, 132b, and 132c arranged in the circumferential direction. It is conveyed so as to be folded back to the front side of the ink jet printer 1 along the rotation direction of the sub roller 131. The cut sheet conveyed to the front side of the inkjet printer 1 by the sub roller 131 is fed between the conveyance roller 133 and the driven roller 134.

4 to 6 are enlarged views of the vicinity of the transport roller 133 and the driven roller 134 showing the operation of the inkjet printer 1 from the thickness detection process to the rear end guide process.
As shown in FIG. 4, the trailing edge detection unit 16 detects that the leading edge of the cut sheet P fed by the sub-roller 131 has passed the detection position D and the cut sheet P exists above. The cut sheet P is sandwiched between the transport roller 133 and the driven roller 134 by the rotation of the transport roller 133, and is transported to the front side of the inkjet printer 1 (transport process). Here, when the cut sheet P is sandwiched between the transport roller 133 and the driven roller 134, the driven roller 134 is pushed upward by the thickness T of the cut sheet P.

  When the driven roller 134 is pushed upward by the thickness T of the cut paper P, the control unit (not shown) of the ink jet printer 1 executes a thickness detection process for detecting the thickness of the recording paper such as the cut paper P. . Specifically, when the driven roller 134 is pushed upward by the thickness T of the cut sheet P, the driven roller holder 137 that supports the driven roller 134 rotates about the support shaft 137c. Then, the arm portion 171 of the thickness detection unit 17 fixed to the driven roller holder 137 rotates together with the driven roller holder 137. The displacement amount of the arm portion 171 is measured by the displacement sensor 172, and the thickness T of the cut sheet P based on the displacement amount of the arm portion 171 is calculated by a calculation unit (not shown).

  The control unit of the ink jet printer 1 compares the information on the thickness of the recording paper input in advance with the information on the thickness T detected by the thickness detection unit 17. If there is a difference exceeding the allowable value between them, the measurement value of the thickness detection unit 17 is recorded in the storage unit as the thickness of the cut sheet P. If the difference is within the allowable value, the information on the thickness of the recording paper input in advance is recorded in the storage unit as the thickness of the cut paper P.

  When the cut sheet P conveyed by the rotation of the conveyance roller 133 reaches a predetermined position on the platen 143, the control unit of the inkjet printer 1 executes a printing process. Specifically, the carriage 142 is moved to move the droplet discharge head 141 to a predetermined position, and ink droplets of each color are discharged from the nozzles of the droplet discharge head 141. Then, a printing process for printing characters and images on the cut paper P by causing the ink droplets to land at predetermined positions on the cut paper P while moving the cut paper P by a predetermined feed amount by the transport roller 133. I do.

  When the leading edge of the cut paper P reaches between the paper discharge roller 135 and the knurled roller 136 shown in FIG. 2, the cut paper P is sandwiched between them and conveyed to the front side of the inkjet printer 1 by the rotation of the paper discharge roller 135. . Here, the rear end PE side of the cut sheet P is sandwiched between the transport roller 133 and the driven roller 134 as shown in FIG. 5, and the discharge speed of the paper discharge roller 135 is set to be slightly higher than that of the transport roller 133. . For this reason, tension is applied to the cut sheet P so as to be pulled to the front end side.

  In a conventional ink jet printer, in order to prevent the occurrence of a flip phenomenon in which the trailing edge of the recording paper is bounced forward in the transport direction due to the influence of the tension acting on the recording paper, the recording paper is composed of a transport roller and a driven roller. The pressure to pinch is controlled. However, it is difficult to control the pressure for sandwiching the recording paper. For this reason, a flip phenomenon occurs in which the trailing edge of the recording paper is flipped forward in the transport direction due to the influence of the tension acting on the recording paper. As a result, the recording paper cannot be accurately conveyed in the conveying direction, and the landing positions of the ink droplets in the printing process are shifted, resulting in a problem that the printing quality is deteriorated.

  Therefore, in the inkjet printer 1 of the present embodiment, the trailing edge detection process in which the trailing edge detection unit 16 detects the trailing edge PE of the recording paper such as the cut sheet P is performed while continuing the printing process. As shown in FIG. 5, the control unit of the inkjet printer 1 detects that the trailing edge PE of the cut sheet P has passed the predetermined detection position D by the trailing edge detection unit 16. At this time, the control unit calculates the rotation amount of the transport roller 133 until the trailing edge PE of the cut sheet P passes between the transport roller 133 and the driven roller 134 by the calculation unit.

  Next, the control unit of the inkjet printer 1 executes a rear end guide process for guiding the rear end PE of the recording paper such as the cut paper P. Specifically, the motor 151 is driven according to the thickness of the cut sheet P recorded in the storage unit in the thickness detection step, and the cam 151 is rotated by rotating the rotation shaft by a predetermined angle. Then, as shown in FIG. 6, the protrusion 151 a of the cam 151 is abutted and fixed so as to support the other end 137 b of the driven roller holder 137.

  As a result, the inferior force received by the elastic member (not shown) on the one end side 137a of the driven roller holder 137 can be received by the pressing force acting on the other end side 137b of the driven roller holder 137 from the projecting portion 151a of the cam 151. An interval between the roller 133 and the driven roller 134 can be defined as an interval G corresponding to the thickness T of the cut paper P. Then, the driven roller 134 is in a state where the bias toward the transport roller 133 is released by the interval G.

As a result, the driven roller 134 is simply placed near the surface of the cut sheet P, and even if a force that pulls the leading end side of the cut sheet P forward in the transport direction is applied, the tension is not applied to the cut sheet P. Almost no longer works.
In this state, when the trailing edge PE of the cut sheet P reaches between the transport roller 133 and the driven roller 134, the trailing edge PE of the cut sheet P is not affected by the tension, as shown in FIG. It passes between the transport roller 133 and the driven roller 134 with the side and the back surface being guided by the driven roller 134 and the transport roller 133, respectively. For this reason, the phenomenon that the trailing edge PE of the cut sheet P is flipped forward in the transport direction by tension is prevented, and the cut sheet P can be transported accurately in the transport direction. Therefore, it is possible to prevent printing defects in the printing process and improve printing quality.

Further, in the present embodiment, the control unit of the inkjet printer 1 determines that the trailing edge PE of the cut sheet P is between the conveying roller 133 and the driven roller 134 based on the rotation amount of the conveying roller 133 calculated in the trailing edge detection step. Immediately before passing, the rear end guide process described above is executed.
Thereby, the trailing edge guide process can be started at an appropriate timing according to the position of the trailing edge PE of the cut sheet P, and the cut sheet P can be conveyed more accurately. Further, until the trailing edge PE of the cut paper P passes between the transport roller 133 and the driven roller 134, the cut paper P is sandwiched between the transport roller 133 and the driven roller 134, and the cut paper P Tension can be applied.

When the trailing edge PE of the cut sheet P passes between the transport roller 133 and the driven roller 134 and the printing process is completed, the cut sheet P is transported by the rotation of the discharge roller 135 shown in FIG. The paper is discharged to a paper discharge tray 122 at the top of the tray 12.
As described above, according to the ink jet printer 1 of the present embodiment, it is not necessary to control the pressure for sandwiching the recording paper such as the cut paper P, and the flipping phenomenon in which the trailing edge of the recording paper is bounced easily and reliably. Can be prevented.

  In addition, by defining the distance between the transport roller 133 and the driven roller 134 as a distance G corresponding to the thickness T of the cut sheet P, not only can the phenomenon of flipping the trailing edge PE of the cut sheet P be avoided, It can be lightly pressed (guided) so that the trailing edge PE of the cut paper P does not float. Therefore, the trailing edge PE is prevented from rising due to warping or movement of the cut paper P, and sudden paper feed fluctuations and contact between the droplet discharge head 141 and the cut paper P are prevented, thereby improving the print quality. Can be made.

  In addition, this invention is not limited to the above-mentioned embodiment, It can implement in various deformation | transformation in the range which does not deviate from the meaning of this invention.

DESCRIPTION OF SYMBOLS 1 Inkjet printer (printing apparatus), 13 conveyance part, 14 printing part, 15 drive part, 16 rear end detection part, 17 thickness detection part, 133 conveyance roller (1st roller), 134 driven roller (2nd roller), 137 Driven roller holder (support part), 151 cam, G interval, P-cut paper (recording medium), PE trailing edge, T thickness

Claims (8)

A conveying step of nipping and conveying the recording medium between the first roller and the second roller biased toward the first roller;
A printing process for performing a printing process on the conveyed recording medium;
A rear end guide step for guiding the rear end of the recording medium by defining an interval between the first roller and the second roller as an interval corresponding to the thickness of the recording medium;
A printing method characterized by comprising:   The printing method according to claim 1, further comprising a rear end detection step of detecting a rear end of the recording medium before the rear end guide step.   The printing according to claim 1 or 2, wherein the trailing edge guide step is executed immediately before the trailing edge of the recording medium passes between the first roller and the second roller. Method.   4. The printing method according to claim 1, further comprising a thickness detection step of detecting a thickness of the recording medium before the rear end guide step. 5. A transport unit that sandwiches and transports the recording medium between the first roller and the second roller biased toward the first roller;
A printing unit that performs a printing process on the conveyed recording medium;
A support portion that supports the second roller and biases the first roller toward the first roller;
A drive unit that defines the position of the support unit and defines the interval between the first roller and the second roller to an interval corresponding to the thickness of the recording medium;
A printing apparatus comprising:   The drive unit includes a motor having a rotation shaft that can rotate a predetermined angle, a cam that can rotate integrally with the rotation shaft, and a cam that contacts the support unit and defines the position of the support unit. The printing apparatus according to claim 5, further comprising:   The printing apparatus according to claim 5, further comprising a rear end detection unit that detects a rear end of the recording medium.   The printing apparatus according to claim 5, further comprising a thickness detection unit that detects the thickness of the recording medium.

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