JP2015136793A - image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable printing even when a print medium is not parallel to a print head.SOLUTION: An image forming apparatus includes: a conveyor belt for conveying a print medium having a polyhedral shape in which one principal surface facing a print head is parallel to the other principal surface; a plurality of movable rollers for pressing the other principal surface; a print medium receiving wall for receiving the one principal surface; a wall turning mechanism for turning the print medium receiving wall; a plurality of rollers which are provided on the print head, and in which the presence or absence of the rotation of the rollers by contact with the print medium can be measured; and a head turning mechanism for turning the print head. When the print head is not parallel to the one principal surface of the print medium, and it is not satisfied that at least three of the plurality of rollers provided on the print head are rotated, the print medium receiving wall and the print head are controlled to be turned, so that the print head is kept parallel to the print surface of the print medium.

Description

  The present invention relates to an image forming apparatus.

A technique for printing on a rectangular parallelepiped print medium is already known (see, for example, Patent Document 1).
The invention described in Patent Document 1 (Japanese Patent Laid-Open No. 2003-191458) is a recording apparatus that can significantly reduce the distribution cost of goods by directly printing on a cardboard box that is a three-dimensional structure. It is intended to provide. The invention described in Patent Document 1 discloses that a recording unit having a recording head, a carrier unit, at least one shaft unit, a control unit, an ink storage unit, and a distance measurement unit are provided.
The carry portion is a member that holds the recording portion and moves the recording portion along the shaft portion. The control unit is a member that controls the recording unit and the carrier unit. The ink storage unit is a member that is integrally attached to the recording unit. The distance measuring unit is a member that measures the distance between the recording surface of the three-dimensional structure and the recording head.

However, the technique described in Patent Document 1 has a problem that printing cannot be performed when the side surface of the print medium and the print head are not parallel.
Accordingly, an object of the present invention is to enable printing even when the print medium and the print head are not parallel.

  In order to solve the above problems, the invention described in claim 1 is directed to a conveyor belt that conveys a multi-sided print medium in which one main surface facing the print head and the other main surface are parallel, and the other main surface. A plurality of movable rollers that press the surface, a print medium receiving wall that receives the one main surface, a wall rotation mechanism that rotates the print medium receiving wall, and a print head provided in contact with the print medium. A plurality of rollers capable of measuring the presence or absence of rotation, and a head rotation mechanism that rotates the print head, and the print head has one main surface of the print medium that is not parallel to the print head. When three or more of the plurality of rollers are not in a rotating state, the print head and the print surface of the print medium are kept parallel by controlling the rotation of the print medium receiving wall and the print head. It is characterized by that.

  According to the present invention, printing can be performed even when the print medium and the print head are not parallel.

It is the whole appearance perspective view concerning one embodiment. FIG. 2 is an enlarged perspective view of the vicinity of a print head 11 shown in FIG. 1. FIG. 2 is an example of a block diagram of the image forming apparatus illustrated in FIG. 1. It is explanatory drawing about rotation of a print head. 4 is an explanatory diagram of a mechanism for rotating a carriage 13 that holds a print head 11 around a horizontal axis 26a. FIG. 4 is an explanatory diagram of a roller for detecting a positional relationship between the print head 11 and a print medium. FIG. 2 is an example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. 6 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG. 1.

<Overview>
The present embodiment includes measuring that the print medium and the print head are not parallel, and controlling the rotation of the print medium and the print head so as to be parallel.

<Configuration>
FIG. 1 is a perspective view of the overall appearance according to an embodiment.
Reference numeral 10 denotes an ink jet printer as an image forming apparatus. A conveyance belt 12 conveys a cardboard box B as an example of a printing medium. The frame 12a of the conveyor belt 12 is supported by a plurality of, for example, four legs 12c. A plate-like member 12b extending in the horizontal direction is fixed to the frame 12a, and a print head 11 and a member for driving the print head 11 are arranged on the plate-like member 12b. Note that the print medium is not limited to include a rectangular parallelepiped, a cube, or the like as long as it is an object having a polyhedral shape in which one main surface and the other main surface are parallel.

FIG. 2 is an enlarged perspective view of the vicinity of the print head 11 shown in FIG.
The print head 11 provided on the plate-like member 12b (see FIG. 1) side of the conveyor belt 12 has nozzle rows in the vertical direction. The print head 11 is held by a carriage 13 and can be moved along the width direction of the transport belt 12 by a maintenance forward mover 21. The carriage 13 holding the print head 11 can be moved along the longitudinal direction of the conveyor belt 12 by a maintenance side mover 22.
In the figure, 15 is a stepping motor for driving the maintenance forward mover 21, and 16 is a printing medium receiving wall for receiving the printing medium. An ink supply mechanism 17 supplies ink to the print head 11. Reference numeral 19 denotes a controller for controlling the rotation of the print medium receiving wall 16 and the movement of the carriage 13 which will be described later. 20 is a power supply unit.

FIG. 3 is an example of a block diagram of the image forming apparatus shown in FIG.
The image forming apparatus includes a controller 19, a head driver 37, a print head rotation control motor 38, a print medium receiving wall control motor 39, a roller rotation presence / absence sensor 40, a print medium presence / absence sensor 41, a sub-scanning motor 42, a conveyance belt 12, and a carriage. 13
The controller 19 includes a head control unit 31, a print head rotation control motor drive unit 32, a print medium receiving wall control motor drive unit 33, a roller rotation presence / absence sensor control unit 34, a print medium presence / absence sensor control unit 35, and a sub-scanning motor drive unit. 36.

The head control unit 31 is a control unit that controls the ejection of ink from the inkjet head, which is the print head 11, via the head driver 37. The head driver 37 is a circuit that controls driving of a piezoelectric element (not shown) provided in each nozzle of the print head 11.
The print head rotation control motor drive unit 32 is a circuit that generates a signal for rotating the carriage 12 together with the print head 11. The print head rotation control motor 38 is a motor that rotates the carriage 13 that holds the print head 11, and for example, a stepping motor is used.
The print medium receiving wall control motor drive unit 33 is a circuit that generates a signal for driving the print medium receiving wall control motor 39 that rotates the print medium receiving wall 16 (see FIG. 2).
The roller rotation presence / absence sensor control unit 34 is a circuit that controls a signal from a sensor that detects the presence / absence of rotation of the movable pressure roller 14 (see FIG. 2). Examples of the roller rotation presence / absence sensor 40 include an encoder directly connected to the movable pressure roller 14. The movable pressure roller 14 is biased by a spring (not shown) so as to push the print medium conveyed on the conveyor belt 12 toward the print head 11.
The print medium presence / absence sensor control unit 35 is a circuit that controls a signal from a sensor that detects whether or not there is a print medium in the vicinity of the print head 11. The print medium presence / absence sensor 41 is a sensor that is provided on the frame 12a of the transport belt 11 and has a function of detecting whether or not there is a print medium, and includes, for example, a reflective photo interrupter.
The sub-scanning motor driving unit 36 is a circuit that generates a signal for driving the sub-scanning motor 42 that rotationally drives the transport belt 11.

FIG. 4 is an explanatory diagram of the rotation of the print head.
FIG. 2 shows a rotation mechanism of the print medium receiving wall 16 provided in the vicinity of the print head.
Reference numeral 18 denotes a rotation shaft for rotating the print medium receiving wall 16 in the direction of the arrow P1, and is provided at one end of the print medium receiving wall 16. At the other end of the print medium receiving wall 16, a rack gear 23 is provided in the horizontal direction so as to be substantially orthogonal to the print medium receiving wall 16. The planar shape of the rack gear 23 is actually an arc centered on the rotation shaft 18. It is arranged so as to mesh with a pinion gear 25 provided on the output shaft of the motor 24. The movable pressure roller 14 rotates in the direction of arrow P2. With this configuration, fine adjustment for making the surface of the print medium with respect to the print head 11 parallel can be performed.

FIG. 5 is an explanatory diagram of a mechanism for rotating the carriage 13 holding the print head 11 around a horizontal axis 26a.
A horizontal shaft 26 a is provided at the upper end of the carriage 13, and a horizontal shaft 26 b is provided at the lower end of the carriage 13. A pulley 27b is provided near the end of the shaft 26a. The pulley 27b is connected to a pulley 27a smaller than the pulley 27b by a belt. The pulley 27a is fixed to the output shaft of the motor 29. The left and right ends of both shafts 26a, 26b are connected by arms 28a, 28b. With this configuration, the print head 11 can rotate in the direction of arrow P3 together with the carriage 13, and the angle of the print head 11 with respect to the print medium can be finely adjusted.

FIG. 6 is an explanatory diagram of a roller for detecting the positional relationship between the print head 11 and the print medium.
A plurality of rollers 30a, 30b, 30c, and 30d having rotational axes that are parallel to the arms 28a and 28b are disposed in the vicinity of the connecting portion between the shafts 26a and 26b and the arms 28a and 28b. These rollers 30a, 30b, 30c, and 30d are connected to a roller rotation presence / absence sensor 40, and it is detected whether the print surface of the print medium and the surface of the print head are parallel to each other. The criterion for determining whether or not the print surface of the print medium is parallel to the print head surface is whether or not three or more rollers 30a, 30b, 30c, 30d of the print head 11 are rotating.

Here, the image forming apparatus of the present embodiment has the following features.
For example, the printing medium B having a rectangular parallelepiped shape is conveyed in the direction of the arrow by the conveying belt 12, one side of the printing medium B is pushed by the movable pressure roller 14, and the other side on the printing head 11 side is received by the wall. Yes. The inkjet printer that performs printing on the transport belt 12 has the following characteristics.
When the print medium presence / absence sensor 41 detects the print medium, detection of whether or not the print surface of the print medium and the print head 11 are parallel is started.
It is assumed that the print head 11 and the print surface of the print medium are parallel, and that a plurality of rollers 30a, 30b, 30c, 30d of the print head 11 are rotating in contact with the print medium.
The reason why the number is three or more is that the minimum number of points required to create a surface is three. In this case, it is possible to provide an ink jet printer as an image forming apparatus in which the print head 11 and the print surface of the print medium are parallel and the distance between the print head 11 and the print medium print surface is constant and satisfactory image quality can be obtained. .
When the print surface of the print head 11 and the print medium are not parallel and three or more of the rollers 30a, 30b, 30c, 30d of the print head 11 are not rotating, control is performed to rotate the print medium receiving wall 16. . Next, the print head is controlled to rotate, that is, the rotation control is sequentially performed with respect to the two axes, so that the print head 11 and the print surface of the print medium can be kept parallel to enable printing.

<Operation 1>
FIG. 7 is an example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The subject of operation is the controller 19.
The conveyance belt 12 is advanced in the direction of the arrow to convey the print medium B (step S101).
If the print medium presence / absence sensor 41 has not detected the print medium B, the process returns to step S101, and if detected, it is determined whether or not three or more rollers 30a, 30b, 30c, 30d of the print head 11 are rotating. To do. When three or more rollers 30a, 30b, 30c, and 30d are rotating, printing is performed on the print medium by the print head 11 (step S104). The inclination of the rotation control is set to 0 [rad] (step S105), the transport belt 12 is advanced, and the print medium is transported. The inclination of 0 [rad] means that the surface of the nozzle row of the print head 11 is vertical (step S106).

When three or more rollers 30a, 30b, 30c, and 30d of the print head are not rotating ([else]), it is determined whether or not the transport position is after the print start position. If the transport position is after the print start position, the transport belt 12 is stopped (step S107).
If the transport position is not after the print start position or has reached ([else]), print medium receiving wall rotation control is performed (step S102). If the rollers 30a and 30b above the print head 11 have not been rotated, the process proceeds to step S107. When three or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating, the process proceeds to step S104. When only two or less rollers 30a, 30b, 30c, 30d of the print head 11 are rotating ([else]), the rotation of the print head 11 is controlled and the rollers 30a, 30b, 30c, 30d of the print head 11 are controlled. It is determined whether or not three or more are rotating.

<Operation 2>
FIG. 8 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The rotation control frequency limit is set to n times (step S201).
The conveyance belt 12 is advanced to convey the print medium (step S202).
If the print medium presence / absence sensor 41 has not detected a print medium, the process returns to step S202. If the print medium presence / absence sensor 41 detects a print medium, three or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotated. Judge whether or not. When three or more of the rollers 30a, 30b, 30c, and 30d are rotating, printing is performed on the print medium by the print head (step S205). The inclination of the rotation control is set to 0 [rad] (step S206), the conveyance belt 12 is advanced, and the print medium is conveyed (step S207).
When only two or less rollers 30a, 30b, 30c, 30d of the print head 11 are rotating ([else]), if the transport position is after the print start position, the transport belt is stopped (step S208).
If the transport position is not after the print start position ([else]), the print medium receiving wall rotation control is performed (step S203). If the rollers 30a and 30b above the print head 11 are not rotated, the process proceeds to step S208. . When three or more of the rollers 30a, 30b, 30c, 30d of the print head 11 are rotated, the process proceeds to step S205. When only two or less of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating, the rotation control of the print head 11 is performed (step S204). The process returns to the step of determining whether or not three or more rollers 30a, 30b, 30c, 30d of the print head 11 are rotating.

<Operation 3>
FIG. 9 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The time limit for rotation control is set to t [sec] (step S301).
The conveyance belt 12 is advanced to convey the print medium (step S302).
If the print medium presence sensor 41 has not detected the print medium, the process returns to step S302. When the print medium presence / absence sensor 41 detects the print medium, if three or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating, the print head 11 performs printing on the print medium (step S305). ). The inclination of the rotation control is set to 0 [rad] (step S306), the conveyance belt 12 is advanced, and the print medium is conveyed (step S307).
When only two or less of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating ([else]), if the transport position is after the print start position, the transport belt 12 is stopped. When the transport position is not after the print start position ([else]), print medium receiving wall rotation control is performed (step S303). If the rollers 30a and 30b above the print head 11 are not rotated, the process proceeds to step S208, and if three or more are rotated, the process proceeds to step S305. When only two or less of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating ([else]), print head rotation control is performed (step S304). The process returns to the step of determining whether or not three or more rollers 30a, 30b, 30c, 30d of the print head 11 are rotating.

<Operation 4>
FIG. 10 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The presence or absence of rotation of the rollers 30a, 30b, 30c, 30d is confirmed. Of the rollers 30a, 30b, 30c, and 30d of the print head 11, software processing is performed in which the number of rotating rollers is x. As a specific example, in order to perform printing, it is necessary to rotate at least three of the rollers 30a, 30b, 30c, and 30d. Means that the change can be made (step S401).
The conveyance belt 12 is advanced to convey the print medium (step S402).
If the print medium presence sensor 41 has not detected the print medium, the process returns to step S402. When the print medium is detected, when x or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating, the print head 11 performs printing on the print medium (step S405). The inclination of the rotation control is set to 0 [rad] (step S406). The conveyance belt 12 is advanced to convey the print medium (step S407).
If the number of rotating rollers among the rollers 30a, 30b, 30c, 30d of the print head 11 is less than x and the transport position is after the print start position, the transport belt 12 is stopped (step S408).
If the transport position is not after the print start position ([else]), the print medium receiving wall rotation control is performed (step S403). If the rollers 30a and 30b above the print head 11 are not rotated, the process proceeds to step S408. . If x or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 have been rotated, the process proceeds to step S405. When the number of rotating rollers among the rollers 30a, 30b, 30c, and 30d of the print head 11 is less than x ([else]), rotation control of the print head 11 is performed (step S404). The process returns to the step of determining whether or not x or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating.

<Operation 4>
FIG. 11 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The conveyance belt 12 is advanced to convey the print medium (step S501).
When the print medium presence / absence sensor 41 has not detected the print medium, the process returns to step S501. When the print medium is detected, the print head 11 performs printing on the print medium (S502).
When two or more of the rollers 30a, 30b, 30c, 30d continue to rotate for 300 [ms] during printing, or two or more of the rollers 30a, 30b, 30c, 30d during printing The non-rotation state continues at 50 [ms] or more. Printing is stopped and the conveyor belt 12 is advanced (step S508). When the remaining printing amount is 50 [mm] or more, printing indicating a printing failure is performed, and when the remaining printing amount is less than 50 [mm], the process proceeds to step S506.
During printing, the roller 30a, 30b, 30c, 30d continues non-rotating for 300 [ms] or two or more of the rollers 30a, 30b, 30c, 30d are non-rotating for 50 [mm] or more. Continue and proceed to step S508. If the number of rotating rollers is less than 3 between printing and if 3 or more of the rollers 30a, 30b, 30c, 30d of the print head 11 are rotated, the print head 11 prints on the print medium. Perform (step S505). The conveyance belt 12 is advanced to convey the print medium (step S506).
During printing, two or more of rollers 30a, 30b, 30c, and 30d do not continue to rotate at 300 [ms] or longer, and two or more rollers do not continue to rotate at 50 [ms] or longer. If the number of rotating rollers is 3 or more between printing and printing, the process proceeds to step S506.
When two or less of the rollers 30a, 30b, 30c, and 30d rotate ([else]), printing medium receiving wall rotation control is performed (step S503), and when the rollers 30a and 30b are not rotated, the conveyance belt 12 is stopped (step S507). When at least three of the rollers 30a, 30b, 30c, and 30d are rotated, print head rotation control is performed (step S504), and it is determined whether or not three or more of the rollers 30a, 30b, 30c, and 30d are rotated. Return to step.
When there are less than three rotating rollers between printing, the conveying belt 12 is advanced to convey the printing medium (step S506).

<Operation 5>
FIG. 12 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The threshold value for the continuous non-rotation time of the rollers 30a, 30b, 30c, 30d on the print head 11 side is set to t [ms] (step S601).
The conveyance belt 12 is advanced to convey the print medium (step S602).
If the print medium presence sensor 41 has not detected the print medium, the process returns to step S602.
When the print medium presence / absence sensor 41 detects the print medium, the print head 11 performs printing on the print medium (step S603). When two or more of the rollers 30a, 30b, 30c, and 30d remain in the non-rotating state for t [ms] or more during printing, printing is stopped and the conveyance belt 12 is advanced (step S609).
When the number of rotating rollers 30a, 30b, 30c, 30d is less than 3 between printing, when the number of rollers 30a, 30b, 30c, 30d of the printing head 11 is rotated, the printing head 11 Printing is performed on the print medium (step S606). The conveyance belt 12 is advanced to convey the print medium (step S607).
During printing, two or more of the rollers 30a, 30b, 30c, and 30d do not rotate more than t [ms], and the number of rollers 30a, 30b, 30c, and 30d that rotate between printing is three. If not less than one ([else]), the process proceeds to step S607.
When step S609 is executed, if the remaining printing amount is 50 [mm] or more, printing indicating printing failure is performed, and the process proceeds to step S607 (step S610).
If the remaining printing amount is less than 50 [mm], the process proceeds to step S607.
When the number of rotating rollers among the rollers 30a, 30b, 30c, and 30d of the print head 11 is two or less ([else]), printing medium receiving wall rotation control is performed (step S604). If the rollers 30a and 30b of the print head 11 are not rotated, the conveying belt 12 is stopped (step S608). When three or more of the print heads 11 rotate ([else]), print head rotation control is performed (step S605), and three or more rollers 30a, 30b, 30c, 30d of the print head 11 rotate. Return to the step of determining whether or not.

<Operation 6>
FIG. 13 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The continuous no-rotation time t [ms] of the rollers 30a, 30b, 30c, and 30d on the print head 11 side is calculated from the speed of the conveyor belt 12.
Here, calculation of the continuous non-rotation time t will be described. The continuous time is to be changed so that the conveyance distance without rotation is the same. As an example, when the transport speed of the transport belt 12 is 100 [mm / s] and the threshold is 300 [ms], when the transport speed of the transport belt 12 is 50 [mm / s], the threshold is 600 [ ms]] is automatically calculated (step S701).
The conveyance belt 12 is advanced to convey the print medium (step S702).
When the print medium presence / absence sensor 41 has not detected the print medium, the process returns to step S702. When the print medium presence / absence sensor 41 detects the print medium, the print head 11 performs printing on the print medium (step S703).
When two or more of the rollers 30a, 30b, 30c, and 30d remain in the non-rotating state for t [ms] or more during printing, printing is stopped and the conveyor belt 12 is advanced (step S709). When the remaining printing amount is 50 [mm] or more, printing indicating printing failure is performed (step S710), the transport belt 12 is advanced, and the print medium is transported (step S707). When the remaining printing amount is less than 50 [mm] ([else]), the process proceeds to step S707.
If the number of rotating rollers among the rollers 30a, 30b, 30c, 30d is less than 3 between printing, the rollers 30a, 30b, 30c, 30d of the print head 11 When three or more are rotated, printing is performed on the print medium by the print head 11. Thereafter, the process proceeds to step S707 (step S706).
If the rollers 30a and 30b of the print head 11 are not rotated or the number of rotating rollers is less than 3 between printing, the process proceeds to step S707.
When the number of rotating rollers among the rollers 30a, 30b, 30c, 30d is two or less ([else]), the printing medium receiving wall rotation control is performed (step S704), and the rollers 30a, 30b are not rotated. Then, the conveyor belt 12 is stopped (step S708). When the rollers 30a and 30b are not rotated ([else]), the rotation control of the print head 11 is performed (step S705), and whether or not three or more rollers 30a, 30b, 30c, and 30d of the print head 11 rotate. Return to the step of determining whether or not.

<Operation 7>
FIG. 14 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The continuous non-rotating conveyance distance of the rollers 30a, 30b, 30c, and 30d of the print head 11 is set to x [mm] (step S801).
The conveyance belt 12 is advanced to convey the print medium (step S802).
If the print medium presence sensor 41 has not detected the print medium, the process returns to step S802.
When the print medium presence / absence sensor 41 detects a print medium ([else]), printing is performed on the print medium by the print head 11 (step S803).
When two or more of the rollers 30a, 30b, 30c, and 30d that are rotating during printing remain in the non-rotating state for the conveyance distance x [mm] or more, printing is stopped and the conveyance belt 12 is advanced (step S809). .
When the number of rollers that rotate between printing is less than three and three or more of the rollers 30a, 30b, 30c, and 30d rotate, printing is performed on the print medium by the print head 11 (step S806). The conveyance belt 12 is advanced to convey the print medium (step S807).
Two or more of the rollers 30a, 30b, 30c, and 30d that rotate during printing remain in the non-rotating state for the transport distance x [mm] or more, and the number of rollers that rotate between printing is less than three. Otherwise ([else]), the process proceeds to step S807.
When the number of rollers 30a, 30b, 30c, 30d of the print head 11 is not three or more ([else]), the print medium receiving wall rotation control is performed (step S804). When 30b is not rotated, the conveyor belt 12 is stopped.
If the rollers 30a and 30b of the print head 11 are not rotated ([else]), the print head 11 is controlled to rotate (step S805), and the number of rotating rollers among the rollers 30a, 30b, 30c, and 30d is 3. Return to the step of determining whether or not there are two or more.
When the remaining printing amount is 50 [mm] or more, printing indicating a printing failure is performed (step S810), and when the remaining printing amount is less than 50 [mm], the process proceeds to step S807.

<Operation 8>
FIG. 15 is another example of a flowchart for explaining the operation of the image forming apparatus shown in FIG.
The remaining printing amount threshold is set to x [mm] (step S901).
The conveyance belt 12 is advanced to convey the print medium (step S902).
If the print medium presence / absence sensor 41 has not detected the print medium, the process returns to step S902. If the print medium presence / absence sensor 41 has detected the print medium ([else]), printing is performed on the print medium by the print head 11 (step S903). ).
During printing, if two or more of the rollers 30a, 30b, 30c, and 30d remain in a non-rotating state for 300 [ms] or more, or two or more continue to be in a non-rotating state for 50 [ms] or more, printing is stopped Then, the conveyor belt 12 is advanced (step S909).
When there are less than three rotating rollers between printing, the conveying belt 12 is advanced to convey the printing medium (step S907).
When three or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotating, printing is performed on the print medium by the print head 11, and the process proceeds to step S907 (step S908).
If the remaining print amount after step S909 is equal to or greater than x [mm], printing indicating printing failure is performed, and the process proceeds to step S907 (step S910). If the remaining printing amount is less than x [mm], the process proceeds to step S907.
When three or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are not rotated ([else]), print medium receiving wall rotation control is performed (step S904). If the rollers 30a and 30b on the upper part of the print head 11 have not been rotated, the conveyor belt 12 is stopped (step S908).
When the rollers 30a and 30b above the print head 11 are not rotated ([else]), rotation control of the print head 11 is performed (step S905). The process returns to the step of determining whether or not three or more of the rollers 30a, 30b, 30c, and 30d of the print head 11 are rotated.

<Effect>
From the above, correction by rotation control (π / 90) [rad] is repeated 5 times, or (π / 90) [rad] / 1 [sec] is continued for 5 seconds as the print head rotation control time, If three or more of the rollers do not rotate, the conveyor belt is stopped. Further, after the control for rotating the printing medium receiving wall is performed, when the upper roller of the print head is not rotated, the conveyance belt is stopped. After printing is completed, the tilt of the rotation control is set to 0 [rad] and the printing medium is conveyed, so that the printing medium receiving wall and the printing head are in the same position as before printing. Therefore, when a multi-sided print medium is transported by a transport belt and printed on the transport belt, the print head and the print medium print surface should be parallel even if the print head and the print medium print surface are not parallel. Printing is possible.

Print medium receiving wall and print head rotation control is set to angular velocity (π / 90) [rad] / 1 [sec], and print medium receiving wall and print head rotation control is continued until three or more rollers rotate. By doing so, the print surface and the print head are parallel with high accuracy.
Since the time limit of the rotation control can be made variable, printing can be enabled by a user operation.
By making it possible to change the number of rollers for checking the presence or absence of rotation among a plurality of rollers of the print head, printing can be made possible by user operation.
If the rotation of two or more rollers on the print head side stops while ejecting from the print head, if it is determined that the remaining print amount is 50 mm or more, the print has failed, and printing failed. The medium can be easily identified.
When the rotation of two or more rollers on the print head side is stopped, nothing is printed when the remaining printing amount is known to be 50 mm or less, so it is possible to prevent erroneous printing in an unprintable area. .
When the rotation of two or more rollers on the print head side is stopped, when the remaining print amount is not known, nothing is printed, so that erroneous printing in an unprintable area can be prevented.
When the rotation of the roller on the print head side is stopped between discharges from the print head, the print medium receiving wall and the print head are controlled after the discharge is completed, so that a printable state can be achieved.
When the time during which the print head side roller does not rotate during ejection is continuously 300 ms or less, erroneous detection of a non-printable state can be prevented by continuing ejection.
Since the threshold value of the continuous time in which the print head side roller does not rotate can be made variable during ejection, printing can be performed by a user operation.
By calculating the continuous time in which the print medium and the print head side roller do not rotate during ejection from the transport speed of the transport belt and setting a threshold value, it is possible to prevent erroneous detection of an unprintable state.
When the transport distance in which there is no contact between the print medium and the print head during ejection is 50 mm or less, erroneous detection of an unprintable state can be prevented by continuing ejection.
Printing can be performed by a user operation by making it possible to vary the threshold value of the conveyance distance in which there is no contact between the print medium and the print head during ejection.
Printing can be performed by a user operation by making it possible to vary the threshold value of the conveyance distance in which there is no contact between the print medium and the print head during ejection.
By setting the tilt of the print head to 0 degrees for both axes during the print end process, printing can be performed by a user operation.
By making the remaining printing amount threshold variable, printing can be performed by a user operation.

  That is, since it is measured that the print medium and the print head are not parallel and the print medium and the print head are controlled to rotate in parallel, printing can be performed even when the print medium and the print head are not parallel.

<Program>
The image forming apparatus according to the present invention described above is realized by a program that causes a computer to execute processing. Examples of the computer include general-purpose computers such as personal computers and workstations, but the present invention is not limited to this. Therefore, as an example, a case where the function of the present invention is realized by a program will be described below.

For example,
A conveying belt that conveys a multi-sided print medium in which one main surface facing the print head and the other main surface are parallel, a plurality of movable rollers that press the other main surface, and the one main surface are received. A printing medium receiving wall, a wall rotating mechanism for rotating the printing medium receiving wall, a plurality of rollers provided in the printing head and capable of measuring the presence or absence of rotation by contacting the printing medium, and the printing head A computer of an image forming apparatus provided with a rotating head rotating mechanism;
When the head rotation mechanism is not in a state where the print head and one main surface of the print medium are parallel and not more than three of the plurality of rollers of the print head are rotating, the print medium receiving wall And a program for executing a procedure for controlling the rotation of the print head.
Such a program may be stored in a computer-readable storage medium.

<Storage medium>
Here, examples of the storage medium include computer-readable storage media such as CD-ROM, flexible disk (FD), and CD-R, semiconductor memories such as flash memory, RAM, ROM, and FeRAM, and HDD.

  CD-ROM is an abbreviation for Compact Disc Read Only Memory. A flexible disk means Flexible Disk: FD. CD-R is an abbreviation for CD Recordable. RAM is an abbreviation for Random-Access Memory. ROM is an abbreviation for Read-Only Memory. FeRAM is an abbreviation for Ferroelectric RAM and means a ferroelectric memory. HDD is an abbreviation for Hard Disc Drive.

  The above-described embodiment shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. is there. For example, in the above description, an inkjet printer has been described. However, the present invention is not limited to this, and an industrial inkjet printer is also applicable.

10 Image forming device (inkjet printer)
DESCRIPTION OF SYMBOLS 11 Print head 12 Conveyor belt 12a Frame 12b Plate-shaped member 12c Leg part 13 Carriage 14 Movable pressure roller 15 Stepping motor 16 Print medium receiving wall 17 Ink supply mechanism 18 Rotating shaft 19 Controller 20 Power supply unit 21 Maintenance forward mover 22 Maintenance side Mover 23 Rack gear 24, 29 Motor 25 Pinion gear 26a, 26b Shaft 27a, 27b Pulley 28a, 28b Arm 30a, 30b, 30c30d Roller 31 Head control unit 32 Print head rotation control motor drive unit 33 Print medium receiving wall control motor drive unit 34 Roller Rotation presence / absence sensor control unit 35 Print medium presence / absence sensor control unit 36 Sub-scanning motor drive unit 37 Head driver 38 Print head rotation control motor 39 Print medium receiving wall Control motor 40 Roller rotation presence / absence sensor 41 Print medium presence / absence sensor 42 Sub-scanning motor

JP 2003-191458 A

Claims (22)

A conveying belt that conveys a multi-sided print medium in which one main surface facing the print head and the other main surface are parallel, a plurality of movable rollers that press the other main surface, and the one main surface are received. A printing medium receiving wall, a wall rotating mechanism for rotating the printing medium receiving wall, a plurality of rollers provided in the printing head and capable of measuring the presence or absence of rotation by contacting the printing medium, and the printing head A rotating head turning mechanism,
When the print head and one main surface of the print medium are not parallel and three or more of the plurality of rollers of the print head are not rotating, the print medium receiving wall and the print head are An image forming apparatus characterized in that the printing head and the printing surface of the printing medium are kept parallel by controlling the rotation.   2. The conveyance belt according to claim 1, wherein when at least one of a plurality of rollers provided in the print head is not rotating when the conveyance position of the print medium reaches a print start position, conveyance of the conveyance belt is stopped. An image forming apparatus.   The image forming apparatus according to claim 1, wherein when one of the plurality of rollers that press the other surface of the print medium is not rotated at the print start position, the conveyance is stopped.   2. The roller according to claim 1, wherein even if the rotation control of the fixed value (π / 90) [rad] degrees is corrected five times for the print medium receiving wall and the print head rotation control, one roller is not rotated. In the case where there is the above, the image forming apparatus is characterized in that the conveyance is stopped.   The image forming apparatus according to claim 4, wherein a limit on the number of times of rotation control can be made variable.   The print medium receiving wall according to claim 1, wherein the print medium receiving wall and the print head rotation control are set to an angular velocity (π / 90) [rad] / 1 [sec], and the print medium receiving wall is rotated until three or more rollers rotate. And an image forming apparatus, wherein the print head rotation control is continued.   7. The method according to claim 6, wherein the conveyance is stopped when the three or more rollers are not rotating even when the print medium receiving wall and the print head rotation control time are 5 seconds or longer. Image forming apparatus.   8. The image forming apparatus according to claim 7, wherein the time limit of the rotation control can be made variable.   2. The image forming apparatus according to claim 1, wherein the number of rollers for checking the presence or absence of rotation among the plurality of rollers of the print head can be changed.   The image forming apparatus according to claim 1, wherein after the rotation of the print medium receiving wall is controlled, conveyance is stopped when an upper roller of the print head is not rotating.   The image forming apparatus according to claim 1, wherein when two or more rotations of the roller on the print head side are stopped during ejection from the print head, printing is stopped and conveyance is continued.   2. The printing according to claim 1, wherein if two or more rotations of the rollers on the print head side are stopped during ejection from the print head and the remaining print amount is found to be 50 mm or more, printing indicating a print failure is performed. An image forming apparatus.   13. The image forming apparatus according to claim 12, wherein when the rotation of two or more rollers on the print head side is stopped, the remaining printing amount is found to be 50 mm or less, nothing is printed. .   13. The image forming apparatus according to claim 12, wherein nothing is printed when the remaining print amount is unknown when two or more rotations of the rollers on the print head side are stopped.   2. The print medium receiving wall and the print head are controlled after the completion of discharge when rotation of the roller on the print head side is stopped between discharge from the print head. 3. Image forming apparatus.   13. The image forming apparatus according to claim 12, wherein the ejection is continued when the time during which the print head side roller does not rotate during ejection is 300 ms or less continuously.   17. The image forming apparatus according to claim 16, wherein a threshold value of a continuous time during which the print head side roller does not rotate can be varied during ejection.   The image forming apparatus according to claim 16, wherein a continuous time in which the print medium and the print head side roller do not rotate during ejection is calculated from a conveyance speed of the conveyance belt, and a threshold value is set.   The image forming apparatus according to claim 16, wherein the ejection is continued when the conveyance distance in which the print medium and the print head do not contact during ejection is 50 mm or less.   18. The image forming apparatus according to claim 17, wherein a threshold value of a conveyance distance in which no contact between the print medium and the print head can be made variable during ejection.   The image forming apparatus according to claim 1, wherein the inclination of the print head is set to 0 degrees on both axes in the print end process.   13. The image forming apparatus according to claim 12, wherein the remaining printing amount threshold value can be made variable.