JP2015037839A - Printer and control method for printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer that shortens a period in which a form is turned over and sent to a conveyor roller again in both-side printing.SOLUTION: A printer includes: a conveyor roller which conveys a printing medium in a predetermined ongoing direction or retracting direction; a printing head which sticks a printing material on the printing medium conveyed by the conveyor roller; an inversion roller which turns over the printing medium conveyed in the retracting direction by the conveyor roller and conveys the turned-over printing medium in the ongoing direction; and a control part which controls the printing head, conveyor roller, and inversion roller. In a predetermined case of both-side printing mode, the control part sticks the printing material on a first surface of the printing medium, then performs non-stop inversion in which the conveyor roller is reversed without stopping the inversion roller during an inversion period from when the rear end of the printing medium conveyed in the retracting direction by the conveyor roller has passed the conveyor roller until when the front end of the printing medium conveyed in the ongoing direction by the conveyor roller reaches the conveyor roller, and sticks the printing material on the second surface of the printing medium after the inversion period.

Description

  The present invention relates to a printer and a printer control method.

  Conventionally, printers that print on both sides of a sheet are known. Such a printer includes a reversing roller for reversing the paper and feeding the reversed paper back to the paper feeding roller. In the ink jet printer, if the ink attached to the first surface of the paper does not dry and comes into contact with the paper feed roller or the platen, the image printed on the first surface of the paper deteriorates. In order to prevent such image deterioration, the reverse roller is temporarily stopped during the period during which the paper is conveyed by the reverse roller to ensure sufficient drying time, and the paper feed roller is reversely rotated while the reverse roller is temporarily stopped. The technique to make is known (patent document 1). Since the necessary drying time varies depending on the amount of ink attached to the first surface of the paper, the temporary stop time of the reversing roller is set according to the amount of ink attached to the first surface of the paper.

JP 2009-155037 A

  However, in order to stop the motor rotating at a constant speed and rotate it again at a constant speed, deceleration and acceleration are required. For this reason, even if the setting of the pause time is set to zero, compared to the case where the motor is rotated at a constant speed, the period of reversing the paper and feeding the reversed paper back to the transport roller becomes longer. That is, when adjusting the ink drying time by setting the reversing roller pause time, double-sided printing may be unnecessarily prolonged.

  The present invention was created to solve such a problem, and an object of the present invention is to provide a printer that reverses paper during double-sided printing and shortens the period during which the reversed paper is fed back to the transport roller. One of them.

(1) A printer for achieving the above object includes a transport roller that transports a print medium in a predetermined forward or backward direction, a print head that attaches a printing material to the print medium transported by the transport roller, A control unit that controls the reversing roller that reverses the printing medium conveyed in the backward direction by the conveying roller and conveys the reversed printing medium in the forward direction, the print head, the conveying roller, and the reversing roller. The control unit, in a predetermined case of the double-sided printing mode, after the printing material is attached to the first surface of the printing medium, and then conveyed in the backward direction by the conveying roller After the rear end of the print medium passes through the transport roller, the front end of the print medium that is transported in the forward direction after being reversed reaches the transport roller. During the reversal period, non-stop reversal is performed to reverse the rotation direction of the transport roller without stopping the reverse roller, and after the reversal period, the printing material is attached to the second surface of the printing medium. Let
According to the present invention, by reversing the transport roller without stopping the reversing roller, the paper can be reversed during double-sided printing, and the period during which the reversed paper is fed back to the transport roller can be shortened.

(2) A printer for achieving the above object may include a first actuator that drives the transport roller and a second actuator that drives the reversing roller.
By adopting this configuration, the mechanism for transmitting the driving force from the actuator to the transport roller can be simplified as compared with the case where the transport roller and the reverse roller are driven by a common actuator.

(3) In the printer for achieving the above object, the control unit may stop the non-stop during the inversion period when the amount of the printing material attached to the first surface of the printing medium is less than a predetermined amount. Inversion may be performed, and the reversing roller may be stopped during the reversing period when the amount of the printing material attached to the first surface of the printing medium is equal to or greater than the predetermined amount.
When this configuration is adopted, when the amount of printing material adhering to the first surface is small, the printing material adheres to the first surface of the printing medium during the period in which the paper is reversed and the reversed paper is fed again to the transport roller. Can be optimized according to quantity.

(4) In the printer for achieving the above object, when the amount of the printing material adhering to the first surface of the print medium is equal to or greater than the predetermined amount, the control unit performs the inversion during the inversion period. You may set the temporary stop time of a roller according to the adhesion amount of the said printing material to the 1st surface of the said printing medium.
By adopting this configuration, when the amount of printing material attached to the first surface is large, the printing material is attached to the first surface of the printing medium during the period of turning the paper over and feeding the reversed paper back to the transport roller. Can be optimized according to quantity.

(5) In the printer for achieving the above object, the control unit sets a rotation speed of the reversing roller during the reversing period according to an amount of the printing material attached to the first surface of the printing medium. May be.
By adopting this configuration, it is possible to optimize the period of reversing the paper and feeding the reversed paper back to the transport roller according to the amount of the printing material attached to the first surface of the print medium.

The schematic diagram concerning embodiment of this invention. The block diagram concerning embodiment of this invention. The flowchart concerning embodiment of this invention. The flowchart concerning embodiment of this invention. The timing chart concerning embodiment of this invention. The flowchart concerning embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the corresponding component in each figure, and the overlapping description is abbreviate | omitted.
1. Configuration of Printer FIG. 1 and FIG. 2 show the configuration of a printer 1 as an embodiment of the present invention. The printer 1 is an ink jet printer that sends a sheet as a printing medium loaded in a sheet feeding cassette (not shown) one by one between the platen 24 and the print head 22 to execute a print job. The paper transport path of the printer 1 includes a reverse roller 12a, a relay roller 13a, a paper feed roller 14a, and a paper discharge roller 15a as a mechanism for transporting paper in order from the paper feed cassette.

  The reversing roller 12a and the relay roller 13a are driven by a paper feeding motor 36 counterclockwise in FIG. 1, thereby causing the paper drawn from a paper feeding cassette (not shown) and the paper fed back by the paper feeding roller 14a to To the paper feed roller 14a. Around the reversing roller 12a, driven rollers 12b and 12c that contact the reversing roller 12a and rotate together with the reversing roller 12a are provided. Around the relay roller 13a, driven rollers 13b and 13c are provided that come into contact with the relay roller 13a and rotate together with the relay roller 13a. The sheet is conveyed while being sandwiched between the reverse roller 12a, the relay roller 13a, and the driven rollers 12b, 12c, 13b, and 13c.

  The paper feed roller 14a as a transport roller rotates with the driven roller 14b by being driven by the paper feed motor 34. The paper discharge roller 15a rotates with the driven roller 15b by being driven by the paper feed motor 34. Here, the direction in which the paper advances from the paper feed roller 14a toward the paper discharge roller 15a is referred to as a forward direction, and the direction in which the paper advances from the paper discharge roller 15a toward the paper feed roller 14a is referred to as a backward direction. As will be described later, the paper feed roller 14a and the paper discharge roller 15a rotate counterclockwise in FIG. 1 to transport the paper in the forward direction when printing on the first and second sides of the paper. Further, when the printing on the first surface of the paper is completed in the double-sided printing mode, the paper feeding roller 14a and the paper discharge roller 15a rotate clockwise in FIG. 1 to convey the paper in the backward direction. When printing on the second side of the paper in the duplex printing mode is completed, the paper rotates counterclockwise in FIG. 1 to transport the paper in the forward direction, and the paper is discharged onto a stacker (not shown).

  A paper feed motor 36 as a second actuator is driven by a drive circuit 35 to rotate the reverse roller 12a and the relay roller 13a. A paper feed motor 34 as a first actuator is driven by a drive circuit 33 to rotate the paper feed roller 14a and the paper discharge roller 15a.

  The displacement of the paper is measured by a rotary encoder 45 that measures the rotation angle of the paper feed motor 36, a rotary encoder 44 that measures the rotation angle of the paper feed motor 34, and the paper sensor 43. The paper sensor 43 is provided between the paper feeding roller 14a and the relay roller 13a. The paper sensor 43 is an optical sensor that detects a change in the amount of light incident on the paper sensor 43 as the paper passes.

  A flexible guide 13d is provided between the paper feeding roller 14a and the relay roller 13a. The upper surface of the flexible guide 13d guides the leading edge of the paper between the relay roller 13a and the driven roller 13b between the paper feeding roller 14a and the driven roller 14b when the relay roller 13a conveys the paper in the forward direction. The lower surface of the flexible guide 13d guides the leading edge of the paper between the relay roller 13a and the driven roller 13c when the paper feeding roller 14a conveys the paper in the backward direction.

The printer 1 is provided with a guide (not shown) for transporting paper along a transport path indicated by a dotted line in FIG. Here, passage points D ₁ , D ₂ , D ₃ , D ₄ , D ₅ , D ₆ , D ₇ , D ₈ , and D ₉ are set as follows in the paper transport path.
D ₁ : Contact point between the reverse roller 12 a and the driven roller 12 b D ₂ : Contact point between the reverse roller 12 a and the driven roller 12 c D ₃ : Contact point between the relay roller 13 a and the driven roller 13 b D ₄ : Detection of the paper sensor 43 Position D ₅ : Contact point D ₆ between the paper feeding roller 14a and the driven roller 14b D ₆ : Position D ₇ of the discharge port on the most upstream side of the print head 22: Position D ₈ of discharge port on the most downstream side of the print head 22 Contact point D ₉ between the paper roller 15a and the driven roller 15b: Contact point between the relay roller 13a and the driven roller 13c Note that the contact point is a contact point when the paper P is not transported, and the paper is transported Then, it is a nip point that conveys the sheet.

In the double-sided printing mode, the controller 30 passes the leading edge of the paper in the order of D ₁ , D ₂ , D ₃ , D ₄ , D ₅ , D ₆ , D ₇ , D ₈ , and then the trailing edge of the paper (first the trailing edge of the sheet) is _D 4 during printing _{surface, D 9, D 1, D} 2, D 3, D 4, D 5, D 6, D 7, reverse roller 12a so as to pass in the order of _{D 8,} relay It controls the roller 13a, the paper feed roller 14a, and the paper discharge roller 15a.

  Between the paper feed roller 14a and the paper discharge roller 15a, a carriage 21 on which the print head 22 is mounted and a platen 24 are provided. The print head 22 is formed with an ejection port (not shown) that ejects ink droplets as a printing material. Ink droplets ejected from the print head 22 adhere to the paper supported by the platen 24. The carriage 21 is supported by the guide rail 23 so as to be able to reciprocate in a direction perpendicular to the paper transport direction. The carriage 21 moves along the guide rail 23 as the carriage motor 32 rotates. The carriage motor 32 is driven by a drive circuit 31 that is controlled by the control unit 30.

  The control unit 30 is a computer including a processor, a memory, a ROM, an input / output circuit, and the like (not shown). When the processor reads the control program from the ROM into the memory and executes it, the control unit 30 controls the carriage motor 32, the paper feed motor 36, the paper feed motor 34, and the print head 22 according to a predetermined sequence. Printing is performed on the paper by alternately repeating sub-scanning for transporting the paper to a predetermined position and main scanning for ejecting ink from the print head 22 at a predetermined timing while moving the print head 22.

2. Outline of Duplex Printing Next, an outline of the operation of the printer 1 in the duplex printing mode will be described with reference to FIG. During the execution of the print job set in the duplex printing mode, the control unit 30 activates the paper feed motor 36 and starts conveying new paper by the reverse roller 12a and the relay roller 13a, and then performs the duplex printing shown in FIG. Start the process.

  First, the control unit 30 continues to determine whether the leading edge of the paper has reached the detection position of the paper sensor 43 until the leading edge of a new paper reaches the detection position of the paper sensor 43 (S1).

  When it is determined that the leading edge of the new paper has reached the detection position of the paper sensor 43, the control unit 30 performs printing on the first surface of the paper (S2). During printing, the control unit 30 drives the paper feed motor 34 so that the paper feed roller 14a and the paper discharge roller 15a rotate counterclockwise in FIG. 1 and transport the paper in the forward direction. During printing, the control unit 30 may or may not drive the paper feed motor 36 so that the relay roller 13a follows the paper.

  When printing on the first surface of the paper is completed, the control unit 30 stops the paper feed motor 34 and the paper feed motor 36 for a predetermined time (S3). As a result, the paper with the ink on the first surface stops in a state where it is held by at least one of the paper feed roller 14a and the driven roller 14b, and the paper discharge roller 15a and the driven roller 15b. The stop time may be a predetermined fixed value or may be set according to the amount of ink ejected onto the first surface of the paper.

After a predetermined time has elapsed after stopping the paper feed motor 34 and the paper feed motor 36, the control unit 30 determines whether the amount of ink ejected from the print head 22 on the first surface of the paper is less than a predetermined threshold value. It is determined whether or not (S4). This threshold is set so that in the process of reversing the paper for printing on the second side of the paper, the leading edge of the paper (the trailing edge of the paper during printing on the first side) is D ₄ , D ₉ , When the paper is transported so as to pass in the order of D ₁ , D ₂ , D ₃ , D ₄ , the value is small enough that the ink attached to the first surface of the paper does not adhere to the relay roller 13a, the reverse roller 12a, etc. is there. The ink discharge amount compared with the threshold value may be the total amount of ink discharged on the first surface of the paper or the maximum amount of ink discharged per unit area of the first surface. The threshold value may be set according to the type of paper, or may be set according to the temperature and humidity.

  When it is determined that the amount of ink ejected from the print head 22 on the first surface of the paper is less than a predetermined threshold, the control unit 30 reverses the rotation direction of the paper feed roller 14a and the paper discharge roller 15a to that during printing. After the sheet is conveyed in the backward direction, the sheet is reversed by the reversing roller 12a, and then the non-stop reversal is performed to reverse the rotation direction of the paper feeding roller 14a and the discharge roller 15a again without stopping the reversing roller 12a. Execute (S5). When it is determined that the amount of ink ejected from the print head 22 on the first surface of the paper is equal to or greater than a predetermined threshold, the control unit 30 rotates the rotation direction of the paper feed roller 14a and the paper discharge roller 15a in the direction opposite to that during printing. The paper is switched and conveyed in the backward direction, and intermittent reversal is executed to temporarily stop the reversing roller 12a and the relay roller 13a during the period of reversing the paper by the relay roller 13a and the reversing roller 12a (S6).

  When the non-stop reversal or intermittent reversal is completed, the control unit 30 executes printing on the second surface of the paper (S8). During printing on the second side of the paper, the control unit 30 drives the paper feed motor 34 so that the paper feed roller 14a and the paper discharge roller 15a rotate counterclockwise in FIG. 1 and transport the paper in the forward direction. To do.

  When printing on the second surface of the paper is completed, the control unit 30 drives the paper feed motor 34 to rotate the paper feed roller 14a and the paper discharge roller 15a, and transports the paper in the forward direction to place it on a stacker (not shown). Discharge (S9).

3. Non-stop inversion Next, the flow of processing in the non-stop inversion will be described with reference to FIGS.
First, the control unit 30 sets the rotation speeds of the paper feed motor 36 and the paper feed motor 34 based on the amount of ink ejected from the print head 22 on the first surface of the paper (S50). At this time, the control unit 30 sets the rotation speed lower as the ink ejection amount increases. The rotation speed of the paper feed motor 36 may be set in two stages, or may be set in three stages or more by providing two or more threshold values to be compared with the ink ejection amount.

  Next, the control unit 30 activates the paper feed motor 36 and the paper feed motor 34 by setting the rotation direction of the paper feed motor 36 to be the same as that during printing and the rotation direction of the paper feed motor 34 to be opposite to that during printing. Then, the sheet conveyance in the backward direction is started (S51). At this time, the reverse roller 12a and the relay roller 13a rotate counterclockwise in FIG. 1, and the paper feed roller 14a and the paper discharge roller 15a begin to rotate clockwise in FIG. The paper feed motor 36 and the paper feed motor 34 are accelerated until reaching the rotational speed set in step S50, and then rotated at a constant speed. The side of the paper that was the trailing edge during the printing of the first surface is the leading edge because the paper is conveyed in the backward direction. When the leading edge of the sheet conveyed in the backward direction reaches the flexible guide 13d, the sheet is guided between the relay roller 13a and the driven roller 13c.

  Next, the control unit 30 continues to determine whether the trailing edge of the paper has reached the detection position of the paper sensor 43 until the trailing edge of the paper reaches the detection position of the paper sensor 43 (S52).

  If it is determined that the trailing edge of the paper has reached the detection position of the paper sensor 43, the control unit 30 stops the paper feeding motor 34 (S53). At this time, since the control unit 30 does not stop the paper feed motor 36, the paper continues to be conveyed by the relay roller 13a and the reverse roller 12a. Further, since the trailing edge of the paper has already passed the detection position of the paper sensor 43, the paper feeding roller 14a and the paper discharge roller 15a positioned behind the conveyed paper do not follow the paper.

  After stopping the paper feed motor 34, the control unit 30 continues to determine whether the leading edge of the reversed paper has reached the detection position of the paper sensor 43 until the leading edge of the paper reaches the detection position of the paper sensor 43 ( S54).

  When the leading edge of the reversed paper reaches the detection position of the paper sensor 43, the control unit 30 sets the rotation direction of the paper feeding motor 34 to the same direction as during printing, restarts the paper feeding motor 34, and the leading edge of the paper is The sheet is conveyed in the forward direction by the relay roller 13a until the contact point between the sheet feeding roller 14a and the driven roller 14b is reached (S55). Although the paper feed motor 36 continues to rotate as shown in FIG. 5 until the paper feed motor 34 is restarted, the leading edge of the paper is still on the paper feed roller 14a in front of the paper sensor 43. Since it has not reached, the paper feed roller 14a does not follow the paper. That is, in the period T from when the trailing edge of the paper that advances in the backward direction after the printing on the first surface passes through the paper sensor 43 to the leading edge of the paper that reverses and advances in the forward direction reaches the paper sensor 43, Since the paper feed roller 14a is not in contact with the paper, there is no problem even if the paper feed roller 14a is stopped or reversed while rotating the relay roller 13a and the reverse roller 12a. Therefore, during this period T, the paper feed motor 34 is stopped and reversed without stopping the paper feed motor 36.

  When the paper feed motor 34 is restarted, the paper feed roller 14a and the paper discharge roller 15a rotate counterclockwise in FIG. Further, the reverse roller 12a and the relay roller 13a continue to rotate counterclockwise in FIG. When the leading edge of the paper reaches the contact point between the paper feeding roller 14a and the driven roller 14b, it becomes possible to start printing on the second surface of the paper.

4). Intermittent Inversion Next, the flow of processing in intermittent inversion will be described with reference to FIG.
First, the control unit 30 sets a temporary stop time of the paper feed motor 36 based on the amount of ink ejected from the print head 22 on the first surface of the paper (S50). At this time, the control unit 30 sets the pause time longer as the amount of ink discharged to the first surface increases. The temporary stop time of the paper feed motor 36 may be set in two stages, or may be set in three stages or more by providing two or more threshold values to be compared with the ink ejection amount.

  The processing from step S61 to step S63 executed by the control unit 30 in the intermittent inversion is the same as the processing from step S51 to step S53 executed by the control unit 30 in the non-stop inversion. That is, even in intermittent inversion, the control unit 30 stops only the paper feed motor 34 without stopping the paper feed motor 36 when the rear end of the paper reaches the paper sensor 43 after starting to transport the paper in the backward direction. . Even if the paper feed motor 34 is stopped in step S63, the paper feed motor 36 continues to rotate, so that the paper continues to be conveyed by the relay roller 13a and the reverse roller 12a.

  After stopping the paper feed motor 34, the control unit 30 continues to carry the paper by rotating the paper feed motor 36 until the leading edge of the paper reaches a predetermined position (S64). When the leading edge of the paper reaches a predetermined position, the control unit 30 temporarily stops the paper feed motor 36 for the time set in step S60 (S66). As for the predetermined position of the sheet for stopping the sheet feeding motor 36, the rear end of the sheet is sandwiched between the relay roller 13a and the driven roller 13c, and the leading end of the sheet is sandwiched between the reversing roller 12a and the driven rollers 12b and 12c. Position. If this state is maintained for a certain period, a wrinkle having a concave printed first surface is attached to the leading edge of the paper along the reverse roller 12a. A sheet with ink attached to one surface is likely to bend in the direction in which the surface with ink attached extends. That is, by printing on the first surface of the paper, the paper has a wrinkle that makes the first surface convex. By holding the paper with the driven rollers 12b and 12c along the cylindrical surface of the reversing roller 12a, a wrinkle that bends in the opposite direction to the wrinkle attached to the paper by printing is added. Further, when the paper is fed directly under the print head 22 by the paper feed roller 14a for printing on the second surface, if the leading edge of the paper is warped toward the print head 22, the print head 22 and the paper are Rub. Therefore, it is preferable to prevent such a problem by attaching a wrinkle having a concave first surface particularly to the front end portion of the paper.

  When the set time for pausing the paper feed motor 36 has elapsed, the control unit 30 activates only the paper feed motor 36, rotates the relay roller 13a and the reverse roller 12a counterclockwise, and resumes paper conveyance (S66). ).

  When the conveyance of the sheet is resumed, the control unit 30 performs the same as in steps S54 and S55 for non-stop reversal, after the leading edge of the sheet reaches the paper sensor (after true determination in step S67), the control unit 30 performs the sheet feeding motor. The rotation direction of 34 is set to the normal rotation direction, the paper feed motor 34 is restarted, and the paper is conveyed in the forward direction by the relay roller 13a until the leading edge of the paper passes the contact point between the paper feed roller 14a and the driven roller 14b. (S68).

  According to the printer 1 described above, by reversing the paper feed roller 14a without stopping the reverse roller 12a, the paper is reversed during double-sided printing, and the period during which the reversed paper is fed again into the paper feed roller 14a is shortened. be able to. That is, when the amount of printing material adhering to the first surface is small, the period of reversing the paper and feeding the reversed paper back to the paper feeding roller 14a is determined according to the amount of ink adhering to the first surface of the paper. Can be optimized. When the amount of ink adhering to the first surface is large, the paper is reversed, and the period during which the reversed paper is fed back to the paper feed roller 14a is temporarily set according to the amount of ink adhering to the first surface of the paper. It can be optimized by adjusting the stop time. Further, the period during which the sheet is reversed and the reversed sheet is fed back to the sheet feeding roller 14a can be optimized by setting the rotation speed of the motor according to the amount of ink attached to the first surface of the sheet. Further, since the reversing roller 12a and the paper feeding roller 14a are driven by different motors, the mechanism for transmitting the driving force from the paper feeding motor 34 to the paper feeding roller 14a can be simplified.

5. Other Embodiments The technical scope of the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.
For example, the rotation speed of the paper feed motor 36 in the intermittent reversal may be set according to the amount of ink ejected onto the first surface of the paper, similarly to the non-stop reversal. If the amount of ink discharged to the first surface of the paper is smaller than a predetermined threshold value, the paper feed motor 34 and the paper feed motor 36 are turned on for a predetermined time before the non-stop reversal after the completion of printing on the first surface. Without stopping, non-stop inversion may be started immediately after the printing of the first surface is completed.

  Further, instead of setting the timing at which the paper feeding motor 34 is temporarily stopped to the timing at which the trailing edge of the paper passes the detection position of the paper sensor 43, the trailing edge of the paper is the contact point between the paper feeding roller 14a and the driven roller 14b. Alternatively, it may be set during the period from when the paper passes through until the detection position of the paper sensor 43 is reached. In this case, the timing at which the paper feed motor 34 is temporarily stopped is determined by the measured value of the rotary encoder 44 of the paper feed motor 34 that drives the paper feed roller 14a. In addition, instead of setting the timing at which the paper feed motor 34 is restarted after being temporarily stopped to the timing at which the leading edge of the paper passes the detection position of the paper sensor 43, the leading edge of the paper passes the detection position of the paper sensor 43. May be set during the period from when the sheet reaches the contact point between the paper feeding roller 14a and the driven roller 14b. In this case, the timing for restarting the paper feed motor 34 is determined by the measured value of the rotary encoder 45 of the paper feed motor 36 that drives the relay roller 13a.

  Also, the paper edge may be detected by a non-contact type sensor other than the optical sensor, the paper edge may be detected by using a contact type sensor, or the displacement of the paper is measured only by the rotary encoder of the paper feed motor. You may do it.

  Further, the sheet may be stopped at different positions a plurality of times during intermittent inversion. In this case, the total pause time may be set according to the amount of ink discharged to the first surface, and a different pause time may be set for each stop position.

  Further, even if the trailing edge of the paper conveyed in the reverse direction during intermittent reversal passes through the paper sensor 43, the paper feed motor 34 is not stopped, and the paper feed motor 34 is stopped at a timing at which the paper feed motor 36 is temporarily stopped. May be. In the intermittent inversion, the paper feed motor 36 may be restarted at a timing when the paper feed motor 36 is restarted after the paper feed motor 36 is temporarily stopped.

  Further, the reverse roller 12a, the relay roller 13a, the paper feed roller 14a, and the paper discharge roller 15a may be driven by a common actuator. In this case, a mechanism for reversing the transmission direction of the driving force from the common actuator to the paper feed roller 14a and the paper discharge roller 15a is required during driving of the reverse roller 12a and the relay roller 13a.

A stepping motor or a servo motor may be used as an actuator for driving the reverse roller 12a, the relay roller 13a, the paper feeding roller 14a, and the paper discharge roller 15a.
The present invention can be applied not only to a serial ink jet printer but also to a line ink jet printer.

DESCRIPTION OF SYMBOLS 1 ... Printer, 12a ... Reverse roller, 12b ... Driven roller, 12c ... Driven roller, 13a ... Relay roller, 13b ... Driven roller, 13c ... Driven roller, 13d ... Flexible guide, 14a ... Paper feed roller, 14b ... Driven roller, 15a ... discharge roller, 15b ... driven roller, 21 ... carriage, 22 ... print head, 23 ... guide rail, 24 ... platen, 30 ... control unit, 31 ... drive circuit, 32 ... carriage motor, 33 ... drive circuit, 34 ... Paper feed motor, 35 ... Drive circuit, 36 ... Paper feed motor, 43 ... Paper sensor, 44 ... Rotary encoder, 45 ... Rotary encoder

Claims (6)

A transport roller for transporting the print medium in a predetermined forward or backward direction;
A print head for adhering a printing material to the print medium conveyed by the conveyance roller;
A reversing roller for reversing the printing medium conveyed in the backward direction by the conveying roller and conveying the reversed printing medium in the forward direction;
A controller that controls the print head, the transport roller, and the reverse roller;
In a predetermined case of the double-sided printing mode, the control unit attaches the printing material to the first surface of the printing medium, and then after the printing medium conveyed in the backward direction by the conveying roller. Rotation of the transport roller without stopping the reversing roller during the reversal period until the leading edge of the print medium transported in the forward direction after reversing after passing through the transport roller reaches the transport roller Performing non-stop reversal to reverse the direction, and after the reversal period, to adhere the printing material to the second surface of the printing medium,
printer. A first actuator that drives the transport roller, and a second actuator that drives the reverse roller,
The printer according to claim 1. The controller is
When the amount of the printing material attached to the first surface of the printing medium is less than a predetermined amount, the non-stop inversion is performed during the inversion period,
When the amount of the printing material attached to the first surface of the printing medium is equal to or greater than the predetermined amount, the reversing roller is stopped during the reversing period.
The printer according to claim 1 or 2. When the amount of the printing material adhering to the first surface of the printing medium is equal to or greater than the predetermined amount, the control unit sets a temporary stop time of the reversing roller during the reversing period to the first surface of the printing medium. Set according to the amount of the printing material attached to
The printer according to claim 3. The control unit sets a rotation speed of the reversing roller during the reversing period according to an amount of the printing material attached to the first surface of the printing medium.
The printer according to claim 3 or 4. A transport roller for transporting the print medium in a predetermined forward or backward direction;
A print head for adhering a printing material to the print medium conveyed by the conveyance roller;
A reversing roller for reversing the printing medium conveyed in the backward direction by the conveying roller and conveying the reversed printing medium in the forward direction;
A method for controlling a printer comprising:
In the case of the duplex printing mode,
Attaching the printing material to the first surface of the printing medium;
After the printing material is attached to the first surface of the printing medium, the forward direction is reversed after the rear end of the printing medium conveyed in the backward direction by the conveying roller passes through the conveying roller. During the reversal period until the leading edge of the print medium transported to the transport roller reaches the transport roller, non-stop reversal is performed to reverse the rotation direction of the transport roller without stopping the reverse roller,
After the inversion period, the printing material is attached to the second surface of the printing medium.
How to control the printer.

Images