JP2018192735A - Printer and slip detection method for conveyance belt - Google Patents

Abstract

To detect a slip between a conveyance belt and a drive roller.SOLUTION: A printer 100 comprises: a printing part 40 performing printing onto a medium 95; a conveyance belt 23 supporting the medium 95; a belt drive roller 25 conveying the medium 95 in a conveyance direction by rotationally moving the conveyance belt 23; a first detection part detecting a rotation amount of the belt drive roller 25; a scale part provided in the conveyance direction; a second detection part detecting a relative amount of movement with respect to the scale part; a holding part 80 being constituted so as to move integrally with the scale part or the second detection part, holding the conveyance belt 23 and moving together with the conveyance belt 23; and a control part determining whether or not a difference between a first amount of movement being an amount of movement of the conveyance belt 23 obtained from the rotation amount detected by the first detection part 92 and a second amount of movement being the amount of movement of the conveyance belt 23 detected by the second detection part is equal to a reference value or more.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printing apparatus and a conveyor belt slip detection method.

In recent years, in printing on fabrics such as cotton, silk, wool, chemical fibers, and mixed spinning, an ink jet printing apparatus that ejects ink toward the surface of the fabric to print a pattern or the like is used. A printing apparatus used in textile printing includes a transport belt that places a medium and transports it in the transport direction in order to handle a stretchable fabric as a medium. In such a printing device,
In order to improve the conveyance accuracy of the conveyance belt, one having a mechanism for detecting the movement amount of the conveyance belt is known. For example, Patent Document 1 discloses an ink jet recording including a movement amount detection unit configured by a scale unit that engages and moves with a conveyor belt and a sensor unit that is fixed to a base and measures the movement amount of the scale unit. An apparatus (printing apparatus) is disclosed.

JP 2013-28143 A

However, the transport belt used for transporting the medium has a driving roller and a transport belt that rotate and move the transport belt as the transport belt stretches or wears on the back of the transport belt while being repeatedly used while being rotated. There may be slippage between the two. Patent Document 1
Although the printing apparatus described in (1) can improve the conveyance accuracy of the conveyance belt by directly measuring the movement amount of the conveyance belt, it is not possible to detect slippage between the driving roller and the conveyance belt that causes a decrease in conveyance accuracy. It was difficult.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A printing apparatus according to this application example conveys the medium in the conveyance direction by rotating the printing unit that performs printing on the medium, a conveyance belt that supports the medium, and the conveyance belt. A drive roller, a first detection unit for detecting the rotation amount of the drive roller, a scale unit provided along the transport direction, and a second detection for detecting a movement amount relative to the scale unit. Configured to move integrally with the unit, the scale unit or the second detection unit,
A gripping portion that grips the transport belt and moves with the transport belt, a first travel amount that is a travel amount of the transport belt determined from the rotation amount detected by the first detection portion, and a second detection portion And a control unit that determines whether or not a difference from the second movement amount that is the movement amount of the conveyor belt to be detected is equal to or greater than a reference value.

According to this application example, the printing apparatus calculates the relative movement amount with respect to the first detection unit that detects the rotation amount of the driving roller that rotates and moves the conveyance belt, and the scale unit provided along the conveyance direction. A second detection unit for detection. Since the scale unit or the second detection unit is provided in the grip unit that grips the transport belt and moves with the transport belt, the second detection unit detects the amount of movement of the transport belt. Then, the printing apparatus performs the first movement amount that is the movement amount of the conveyance belt obtained from the rotation amount detected by the first detection unit, and the second movement that is the movement amount of the conveyance belt detected by the second detection unit. A control unit is provided for determining whether or not the difference from the quantity is greater than or equal to a reference value. Thereby, the printing apparatus can detect that the slip more than the reference value occurred between the conveyance belt and the driving roller.

Application Example 2 In the printing apparatus according to the application example described above, when the control unit determines that the difference between the first movement amount and the second movement amount is greater than or equal to a reference value, a warning operation is performed. It is preferable.

According to this application example, the control unit performs a warning operation when the difference between the first movement amount and the second movement amount is greater than or equal to the reference value. As a result, it is possible to notify the user that slippage exceeding the reference value has occurred between the transport belt and the driving roller.

Application Example 3 In the printing apparatus according to the application example, even when the control unit determines that the difference between the first movement amount and the second movement amount is equal to or greater than a reference value, It is preferable to continue the printing operation.

According to this application example, the control unit continues the printing operation on the medium even when the difference between the first movement amount and the second movement amount is equal to or larger than the reference value. Even when slippage occurs between the conveyance belt and the drive roller, the control unit can detect the actual movement amount of the conveyance belt by the second detection unit, and this influence immediately affects the printing operation. is not. Since the printing apparatus of this application example continues printing even when slippage is detected between the conveyance belt and the driving roller, it is possible to suppress a decrease in production efficiency of the printing apparatus.

Application Example 4 In the printing apparatus according to the application example described above, when the number of times the transport belt transports the medium is n, the control unit determines the difference between the first travel distance and the second travel distance. Is stored as the n-th slip amount, and the difference between the first movement amount and the second movement amount when the medium is transported before the n-th slip amount is stored is the n-1th slip amount. Is preferably stored as

According to this application example, the control unit stores the difference between the first movement amount and the second movement amount as the n−1th slip amount and the nth slip amount in time series. The n-th slip amount represents a slip amount between the transport belt and the drive roller that is generated when the transport belt transports the medium for the nth time. Therefore, the slip amount between the transport belt and the drive roller over time. Changes can be confirmed.

Application Example 5 In the printing apparatus according to the application example described above, when the control unit determines that the change amount of the n-th slip amount with respect to the n-1 slip amount is equal to or greater than a reference value, a warning operation is performed. It is preferable to carry out.

According to this application example, the control unit performs a warning operation when the change amount of the n-th slip amount with respect to the (n-1) -th slip amount is equal to or greater than the reference value. By comparing the n-1 slip amount with the nth slip amount, it becomes possible to predict that the slip amount between the conveyor belt and the driving roller will be large, so it is possible to notify the user of the abnormality of the device in advance. I can inform you.

Application Example 6 In the printing apparatus according to the application example, when the number of rotations of the conveyance belt is m, the control unit counts the number of rotations of the conveyance belt by the second detection unit, The rotation amount of the driving roller detected by the first detection unit when the conveyance belt makes one rotation is stored as the m-th rotation amount, and the conveyance belt is set to 1 before the m-th rotation amount is stored. The rotation amount of the drive roller detected when rotating is stored as the m-1st rotation amount, and whether or not the change amount of the mth rotation amount with respect to the m-1st rotation amount is equal to or greater than a reference value. It is preferable to judge.

According to this application example, the control unit stores the rotation amount of the driving roller detected by the first detection unit when the conveyance belt makes one rotation as the m−1th rotation amount and the mth rotation amount in time series. . Then, the control unit determines whether or not the difference between the m−1th rotation amount and the mth rotation amount is equal to or greater than a reference value. M
When the difference between the −1 rotation amount and the m-th rotation amount occurs, it means that a slip is generated between the conveyance belt and the driving roller. It can be determined whether or not slipping has occurred. Further, it is possible to confirm the change with time of the slippage between the conveyor belt and the driving roller.

Application Example 7 In the printing apparatus according to the application example described above, the driving roller is provided downstream of the printing unit in the transport direction, and the grip unit is upstream of the printing unit in the transport direction. It is preferable to grip the conveyor belt on the side.

According to this application example, the driving roller for rotating the transport belt is provided on the downstream side of the printing unit, and the gripping unit grips the transport belt on the upstream side of the printing unit. When the driving roller is rotationally driven to move the grip portion together with the transport belt in the transport direction, the transport belt on the downstream side in the transport direction from the drive roller and the upstream portion in the transport direction from the grip portion is easily loosened.
However, by setting the positional relationship between the driving roller and the gripping portion in this way, it is possible to make the easy-to-loose part of the transport belt within a short range, so that it is difficult for slippage between the drive roller and the transport belt. be able to.

Application Example 8 A method for detecting slippage of a conveyance belt according to this application example includes a printing unit that performs printing on a medium, a conveyance belt that supports the medium, and the conveyance belt by rotating the conveyance belt. A driving roller that conveys the first roller, a first detection unit that detects a rotation amount of the driving roller,
A scale unit provided along the transport direction, a second detection unit that detects a movement amount relative to the scale unit, and the scale unit or the second detection unit so as to move together. And a gripping unit that grips the transport belt and moves together with the transport belt. The slip detection method of the transport belt in a printing apparatus includes the rotation amount detected by the first detection unit. A determination step of determining whether a difference between a first movement amount that is the movement amount of the conveyance belt and a second movement amount that is the movement amount of the conveyance belt detected by the second detection unit is greater than or equal to a reference value. It is characterized by including.

According to this application example, the slip detection method of the conveyor belt includes the first movement amount that is the amount of movement of the conveyor belt obtained from the rotation amount detected by the first detection unit, and the conveyance detected by the second detection unit. A determination step is included for determining whether or not the difference from the second movement amount, which is the movement amount of the belt, is equal to or greater than a reference value. The first movement amount is the movement amount of the conveyance belt obtained from the rotation amount of the driving roller that rotates the conveyance belt detected by the first detection unit. The second movement amount is a relative movement amount between the scale unit and the second detection unit provided along the conveyance direction. Since the scale unit or the second detection unit moves integrally with the gripping unit that grips the transport belt, the second detection unit detects the amount of movement of the transport belt. Therefore, according to the slip detection method for the transport belt, it is possible to detect that a slip greater than the reference value has occurred between the transport belt and the drive roller.

1 is a schematic diagram illustrating a schematic overall configuration of a printing apparatus according to an embodiment. The top view which shows the principal part of a printing apparatus. The perspective view which shows the structure of a belt movement amount measurement part. Sectional drawing in the AA in FIG. FIG. 3 is an electrical block diagram illustrating an electrical configuration of the printing apparatus. The flowchart figure explaining the slip detection method of a conveyance belt. FIG. 9 is a flowchart for explaining a conveyance belt slip detection method according to Modification 1; FIG. 10 is a flowchart for explaining a conveyance belt slip detection method according to a second modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the scale of each layer and each member is different from the actual scale so that each layer and each member can be recognized.
1 to 4, for convenience of explanation, the X axis, the Y axis, and the Z axis are illustrated as three axes that are orthogonal to each other. The end side is defined as “− side”. The direction parallel to the X axis is referred to as “X axis direction”, the direction parallel to the Y axis is referred to as “Y axis direction”, and the direction parallel to the Z axis is referred to as “Z axis direction”.

(Embodiment)
<Schematic configuration of printing device>
FIG. 1 is a schematic diagram illustrating a schematic overall configuration of a printing apparatus according to an embodiment. FIG. 2 is a plan view showing a main part of the printing apparatus. First, a schematic configuration of the printing apparatus 100 according to the present embodiment will be described with reference to FIGS. 1 and 2. In the present embodiment, an ink jet printing apparatus 100 that performs printing on the medium 95 by forming an image or the like on the medium 95 will be described as an example.

As illustrated in FIG. 1, the printing apparatus 100 includes a medium transport unit 20, a medium contact unit 60, and a printing unit 40.
, A drying unit 27, a belt movement amount measuring unit 70, a cleaning unit 50, and the like. And it has the control part 1 which controls each of these parts. Each unit of the printing apparatus 100 is attached to the frame unit 90.

The medium transport unit 20 transports the medium 95 in the transport direction. The medium transport unit 20 includes a medium supply unit 10, a transport roller 22, a transport belt 23, a belt rotation roller 24, a belt drive roller 25 as a drive roller, transport rollers 26 and 28, and a medium recovery unit 30. First, the conveyance path of the medium 95 from the medium supply unit 10 to the medium recovery unit 30 will be described. In the present embodiment, the direction along the gravity is the Z axis, the direction in which the medium 95 is conveyed in the printing unit 40 is the X axis, and the width direction of the medium 95 that intersects both the Z axis and the X axis is the Y axis. And The positional relationship along the conveyance direction of the medium 95 or the movement direction of the conveyance belt 23 is also referred to as “upstream side” or “downstream side”.

The medium supply unit 10 supplies a medium 95 for forming an image to the printing unit 40 side.
As the medium 95, for example, natural fiber, cotton, silk, hemp, mohair, wool, cashmere, recycled fiber, synthetic fiber, nylon, polyurethane, polyester, or a woven or non-woven fabric made of these blends can be used. . The woven fabric or the nonwoven fabric may be coated with a pretreatment agent for promoting color development and fixing properties. The medium supply unit 10 includes a supply shaft portion 11 and a bearing portion 12. The supply shaft portion 11 is formed in a cylindrical shape or a columnar shape, and is provided to be rotatable in the circumferential direction. A belt-like medium 95 is wound around the supply shaft portion 11 in a roll shape. The supply shaft portion 11 is detachably attached to the bearing portion 12. Thus, the medium 95 that has been wound around the supply shaft portion 11 in advance can be attached to the bearing portion 12 together with the supply shaft portion 11.

The bearing portion 12 rotatably supports both ends of the supply shaft portion 11 in the axial direction. Medium supply unit 1
0 has a rotation drive unit (not shown) for rotating the supply shaft unit 11. The rotation drive unit rotates the supply shaft unit 11 in the direction in which the medium 95 is sent out. The operation of the rotation drive unit is controlled by the control unit 1. The conveyance roller 22 relays the medium 95 from the medium supply unit 10 to the conveyance belt 23.

The conveyance belt 23 is held between at least two rollers that rotate the conveyance belt 23, and conveys the medium 95 in the conveyance direction (+ X axis direction) as the conveyance belt 23 rotates. Specifically, the conveyor belt 23 is formed in an endless shape by connecting both ends of a belt-like belt,
A belt rotating roller 24 and a belt driving roller 25 are hung between two rollers. The conveyor belt 23 is held in a state where a predetermined tension is applied so that a portion between the belt rotating roller 24 and the belt driving roller 25 is horizontal. An adhesive layer 29 for adhering the medium 95 is provided on the surface (support surface) 23 a of the transport belt 23. The conveyance belt 23 supports (holds) a medium 95 that is supplied from the conveyance roller 22 and is in close contact with the adhesive layer 29 by a medium contact portion 60 described later. As a result, a stretchable fabric or the like is used as the medium 95.
Can be treated as

The belt rotation roller 24 and the belt driving roller 25 are an inner peripheral surface 23 of the transport belt 23.
Support b. In addition, a configuration in which a support portion such as a roller that supports the conveyance belt 23 is provided between the belt rotation roller 24 and the belt driving roller 25 may be employed.

The belt drive roller 25 conveys the medium 95 in the conveyance direction by rotating the conveyance belt 23. The belt driving roller 25 is provided with a motor 25a that rotationally drives the belt driving roller 25. The belt driving roller 25 is provided on the downstream side of the printing unit 40 in the conveyance direction of the medium 95, and the belt rotation roller 24 is provided on the upstream side of the printing unit 40. When the belt driving roller 25 is driven to rotate, the conveyor belt 23 rotates as the belt driving roller 25 rotates, and the belt rotating roller 24 rotates as the conveyor belt 23 rotates. The medium 95 supported by the conveyance belt 23 is conveyed in the conveyance direction (+ X axis direction) by the rotation of the conveyance belt 23, and the medium 95 is printed by the printing unit 40 described later.
An image is formed.

The belt drive roller 25 is provided with a disk-shaped rotary scale 93 on one side surface that intersects the rotation axis of the belt drive roller 25. The rotary scale 93 of the present embodiment uses a magnetic scale in which magnets having different polarities are alternately arranged along the circumferential direction. A first detection unit 92 is provided at a position facing one side surface of the belt driving roller 25 via the rotary scale 93. The first detection unit 92 includes an element (for example, a Hall element or an MR element) that changes a change in magnetic field into an electric signal, and detects a movement amount relative to the rotary scale 93. That is, the first detection unit 92 is a so-called rotary encoder, and detects the rotation amount of the belt driving roller 25.

In the present embodiment, the rotary encoder (first detection unit 92) that detects the rotation amount of the belt driving roller 25 is illustrated, but a rotary encoder that detects the rotation amount of the motor 25a may be used.
Further, in the present embodiment, a so-called magnetic encoder that obtains the relative movement amount of the rotary scale 93 and the first detection unit 92 by a change in the magnetic field is illustrated, but an optical encoder that obtains the movement amount by an optical change is used. There may be.

In the present embodiment, the surface 23a of the conveyor belt 23 faces the printing unit 40 (+ Z axis side).
The medium 95 is supported by the belt rotating roller 24 together with the conveyor belt 23.
From the side to the belt drive roller 25 side. On the side (−Z axis side) where the surface 23 a of the conveyor belt 23 faces the cleaning unit 50, only the conveyor belt 23 moves from the belt driving roller 25 side to the belt rotating roller 24 side. The transport belt 23 has been described as including the adhesive layer 29 that allows the medium 95 to be in close contact therewith, but is not limited thereto. For example, the conveyance belt may be an electrostatic adsorption type belt that adsorbs a medium to the belt with static electricity.

The transport roller 26 peels the medium 95 on which the image is formed from the adhesive layer 29 of the transport belt 23. The transport rollers 26 and 28 relay the medium 95 from the transport belt 23 to the medium recovery unit 30.

The medium collection unit 30 collects the medium 95 conveyed by the medium conveyance unit 20. The medium recovery unit 30 includes a winding shaft portion 31 and a bearing portion 32. The winding shaft portion 31 is formed in a cylindrical shape or a columnar shape, and is provided to be rotatable in the circumferential direction. The winding shaft 31 includes
A belt-like medium 95 is wound up in a roll shape. The winding shaft portion 31 is detachably attached to the bearing portion 32. Thereby, the medium 95 in the state of being wound around the winding shaft portion 31.
Can be removed together with the winding shaft 31.

The bearing portion 32 rotatably supports both ends of the winding shaft portion 31 in the axial direction. The medium recovery unit 30 includes a rotation driving unit (not shown) that drives the winding shaft unit 31 to rotate. The rotation driving unit rotates the winding shaft portion 31 in the direction in which the medium 95 is wound. The operation of the rotation drive unit is controlled by the control unit 1.

Next, the medium contact portion 60 and the belt movement amount measuring portion 7 provided along the medium conveying portion 20.
0, the printing unit 40, the drying unit 27, and the cleaning unit 50 will be described.

The medium contact portion 60 is for bringing the medium 95 into close contact with the transport belt 23. Medium adhesion part 6
0 is provided on the upstream side (−X axis side) from the printing unit 40 in the transport direction. The medium contact portion 60 includes a pressing roller 61, a pressing roller driving unit 62, and a roller support unit 63. The pressing roller 61 is formed in a cylindrical shape or a columnar shape, and is provided to be rotatable in the circumferential direction. The pressing roller 61 is disposed so that the axial direction intersects the transport direction so as to rotate in a direction along the transport direction. The roller support portion 63 is connected to the conveyor belt 23.
Is provided on the inner peripheral surface 23 b side of the conveyor belt 23 facing the pressing roller 61.

The pressing roller driving unit 62 presses the pressing roller 61 in the conveying direction (+ X axis direction) and the direction opposite to the conveying direction (−X axis direction) while pressing the pressing roller 61 downward in the vertical direction (−Z axis side). The roller 61 is moved. The medium 95 superimposed on the conveyor belt 23 is a pressing roller 61.
And the roller support 63 are pressed against the transport belt 23. Thereby, the medium 95 can be reliably adhered to the adhesive layer 29 provided on the surface 23 a of the transport belt 23, and the occurrence of the floating of the medium 95 on the transport belt 23 can be prevented.

The belt movement amount measuring unit 70 is provided between the medium contact unit 60 and the printing unit 40. The belt movement amount measuring unit 70 will be described in detail later.

The printing unit 40 is disposed above (+ Z axis side) with respect to the position where the transport belt 23 is disposed, and performs printing on the medium 95 placed on the surface 23 a of the transport belt 23. The printing unit 40 includes a head unit 42, a carriage 43 on which the head unit 42 is mounted, and a carriage 4.
3 for moving the carriage 3 in the width direction (Y-axis direction) of the medium 95 intersecting the transport direction.
5 etc. The head unit 42 according to this embodiment includes four subunits 42a. Further, the subunit 42a includes ink (for example, an ink supplied from an ink supply unit (not shown) to the medium 95 placed on the transport belt 23). A plurality of discharge heads (not shown) for discharging droplets of yellow, cyan, magenta, black, etc.) are provided.

The carriage moving unit 45 is provided above the conveyance belt 23 (+ Z axis side). The carriage moving unit 45 has a pair of guide rails 45a and 45b extending along the Y-axis direction. The guide rails 45a and 45b are bridged between frame portions 90a and 90b that are vertically provided outside the conveyor belt 23. The head unit 42 is supported by the guide rails 45a and 45b so as to be capable of reciprocating along the Y-axis direction together with the carriage 43.

The carriage moving unit 45 includes a moving mechanism and a power source (not shown). As the moving mechanism, for example, a mechanism in which a ball screw and a ball nut are combined, a linear guide mechanism, or the like can be employed. Furthermore, the carriage moving unit 45 includes a motor (not shown) as a power source for moving the carriage 43 along the guide rails 45a and 45b. Various motors such as stepping motors, servo motors, and linear motors can be employed as the motor. When the motor is driven by the control of the control unit 1, the head unit 42 moves along the Y axis direction together with the carriage 43.

The drying unit 27 is provided between the transport roller 26 and the transport roller 28.
The drying unit 27 is for drying the ink ejected on the medium 95. The drying unit 27 includes, for example, an IR heater, and the ink ejected on the medium 95 is driven by driving the IR heater. It can be dried in a short time. Thereby, the belt-shaped medium 95 on which an image or the like is formed can be wound around the winding shaft portion 31.

The cleaning unit 50 is disposed between the belt rotating roller 24 and the belt driving roller 25 in the X-axis direction. The cleaning unit 50 includes a cleaning unit 51, a pressing unit 52, and a moving unit 5.
3. The moving unit 53 integrally moves the cleaning unit 50 along the floor surface 99 and fixes it to a predetermined position.

The pressing part 52 is, for example, an elevating device constituted by an air cylinder 56 and a ball bush 57, and makes the cleaning part 51 provided on the upper part abut on the surface 23a of the conveyor belt 23. The cleaning unit 51 includes a belt rotating roller 24 and a belt driving roller 25.
The surface (support surface) 23a of the conveyor belt 23 that is applied with a predetermined tension between the belt drive roller 25 and moves from the belt drive roller 25 toward the belt rotation roller 24 is washed from below (−Z axis direction). .

The cleaning unit 51 includes a cleaning tank 54, a cleaning roller 58, and a blade 55. The cleaning tank 54 is a tank for storing a cleaning liquid used for cleaning ink and foreign matters attached to the surface 23 a of the conveyor belt 23, and the cleaning roller 58 and the blade 55 are provided inside the cleaning tank 54. As the cleaning liquid, for example, water or a water-soluble solvent (alcohol aqueous solution or the like) can be used, and a surfactant or an antifoaming agent may be added as necessary.

When the cleaning roller 58 rotates, the cleaning liquid is supplied to the surface 23a of the transport belt 23, and the cleaning roller 58 and the transport belt 23 slide. As a result, ink adhering to the conveyor belt 23, fabric fibers as the medium 95, and the like are removed by the cleaning roller 58.

The blade 55 can be formed of a flexible material such as silicon rubber, for example.
The blade 55 is provided downstream of the cleaning roller 58 in the conveyance direction of the conveyance belt 23. When the conveying belt 23 and the blade 55 slide, the conveying belt 23 is moved.
The cleaning liquid remaining on the surface 23a is removed.

FIG. 3 is a perspective view illustrating a configuration of the belt movement amount measurement unit. 4 is a cross-sectional view taken along line AA in FIG.
It is sectional drawing in a line. Next, the configuration of the belt movement amount measuring unit 70 will be described with reference to FIGS.

The belt movement amount measuring unit 70 is provided on the upstream side of the printing unit 40 and is provided along either one of both ends in the width direction (Y-axis direction) of the transport belt 23. The belt movement amount measuring unit 70 according to the present embodiment is provided on the + Y axis side of the conveyor belt 23. The belt movement amount measuring unit 70 is provided on a base 71 having a long rectangular parallelepiped shape along the conveyance direction (X-axis direction) of the medium 95, a scale attaching unit 73 provided above the base 71, and the base 71. And a gripping portion 80 that moves along a guide rail 72 that extends in the X-axis direction, a return portion 76 that moves the gripping portion 80 to the upstream side in the transport direction, and the like.

The scale attaching part 73 is bridged between pillar parts 73a and 73b provided perpendicularly to both ends in the longitudinal direction (X-axis direction) of the base 71. The scale sticking portion 73 has a protruding portion that protrudes like a bowl in the −Y-axis direction, and a part thereof overlaps the transport belt 23 in plan view.
A scale portion 75 is provided on the lower surface (the surface on the −Z axis side) of the protruding portion of the scale pasting portion 73 along the conveyance direction of the medium 95. The scale unit 75 of this embodiment uses a magnetic scale in which magnets having different polarities are alternately arranged.

The gripping unit 80 of the present embodiment grips the transport belt 23 on the upstream side in the transport direction from the printing unit 40. When the belt driving roller 25 is rotationally driven to move the gripping portion 80 in the gripping state together with the transport belt 23 in the transport direction, it is downstream of the belt drive roller 25 in the transport direction and upstream of the grip portion 80 in the transport direction. The conveyor belt 23 on the side portion is easy to loosen. However, by setting the positional relationship between the belt driving roller 25 and the gripping portion 80 in this way, it is possible to make the easy-to-loose part of the transport belt 23 within a short range. It is possible to prevent slippage between them.

The gripping unit 80 includes a gripping substrate 81, a guide block 82, a second detection unit 85, and the like. The gripping substrate 81 has a rectangular plate shape that is long in the width direction (Y-axis direction) of the transport belt 23. An end portion 81c on the −Y-axis side of the grip substrate 81 substantially coincides with the −Y-axis side wall 73c of the scale pasting portion 73 in a plan view and overlaps the transport belt 23. An end 81d on the + Y-axis side of the holding substrate 81 protrudes in the + Y-axis direction from the side wall 71d on the + Y-axis side of the base 71 in plan view. A guide block 82 is provided on the bottom surface (the surface on the −Z axis side) of the gripping substrate 81. The guide block 82 is formed with a concave groove that opens to the −Z axis side, following the shape of the guide rail 72 protruding in a convex shape. When the guide block 82 and the guide rail 72 are engaged, the grip portion 80 is configured to be able to reciprocate along the transport direction (X-axis direction).

An elastic member 83 is provided on the upper surface (the surface on the + Z-axis side) of the gripping substrate 81. The elastic member 83 has a rectangular plate shape shorter than the gripping substrate 81. An end 83 d on the + Y-axis side of the elastic member 83 is joined to the gripping substrate 81 at the approximate center of the gripping substrate 81. The end portion 83c on the −Y axis side of the elastic member 83 is substantially coincident with the end portion 81c on the −Y axis side of the holding substrate 81 in a plan view. The end portion 81 c of the holding substrate 81 and the end portion 83 c of the elastic member 83 have a gap slightly wider than the thickness of the transport belt 23. The gripping portion 80 is configured to be able to hold the transport belt 23 between the end portion 81 c of the gripping substrate 81 and the end portion 83 c of the elastic member 83 by the elastic force of the elastic member 83. As the material of the elastic member 83, carbon fiber having a specific gravity lighter than that of a metal material and excellent in strength, elastic modulus, and wear resistance can be used.

The grip 80 has a ferromagnetic body 84. The ferromagnetic body 84 is formed of the transport belt 2 in plan view.
3 is provided on the upper surface (the surface on the + Z-axis side) of the elastic member 83 that does not overlap with 3. As the ferromagnetic material 84, iron, nickel, cobalt, or the like can be used.

In addition, a switching unit 74 that switches the gripping unit 80 between a gripping state and a non-holding state is provided at a position on the lower surface of the gripping substrate 81 of the gripping unit 80 and facing the ferromagnetic body 84. The switching unit 74 includes an electromagnet, and the ferromagnetic body 84 is attracted to the switching unit 74 (electromagnet) by a magnetic force generated when a current flows through the electromagnet. At this time, the elastic member 83 is moved to the holding substrate 8.
It is elastically deformed to one side, and the conveying belt 23 is held between the holding substrate 81 and the elastic member 83 by the elastic force. Further, when the current flowing through the electromagnet is interrupted, the gripping portion 80 changes from the gripping state to the non-griping state.

On the upper surface of the end 83c of the elastic member 83 and at a position facing the scale 75, the second
A detection unit 85 is provided. The second detection unit 85 includes an element (for example, a Hall element or an MR element) that changes the change of the magnetic field into an electric signal, and detects the amount of movement relative to the scale unit 75. The second detection unit 85 of the present embodiment is provided on a pedestal that is arranged close to the scale unit 75. Since the second detection unit 85 is configured to move integrally with the gripping unit 80, it detects the amount of movement of the transport belt 23 when the gripping unit 80 that grips the transport belt 23 moves with the transport belt 23. Can do.

The return unit 76 moves the grip unit 80 in a non-grip state in the direction opposite to the transport direction.
The return unit 76 includes a moving lever 78 and a lever moving unit 77 that reciprocates the moving lever 78 along the transport direction. The lever moving part 77 has a rectangular parallelepiped shape that is long in the transport direction, and is fixed to the side wall 71 d of the base 71 on the + Y axis side. On the upper surface (+ Z-axis side surface) and the lower surface (−Z-axis side surface) of the lever moving portion 77, concave guide grooves extending in the transport direction are formed.

The moving lever 78 includes a pedestal 78a and a pedestal 78 having convex protrusions that follow the shape of the guide groove.
and a long handle portion 78b extending in the vertical direction (+ Z-axis direction). The moving lever 78 is configured to be able to reciprocate along the guide groove of the lever moving portion 77. Lever moving part 7
7 includes a moving mechanism (not shown) that reciprocates the moving lever 78 in the transport direction. For example, an air cylinder can be employed as the moving mechanism. Move lever 7
8 is moved upstream in the transport direction by the lever moving portion 77, the long handle portion 78b of the moving lever 78 and the gripping substrate 81 of the gripping portion 80 come into contact with each other, and the gripping portion 80 in the non-grip state is moved in the transport direction. It is returned to the upstream side in the reverse direction. Accordingly, the gripping portion 80 in the gripping state can be repeatedly moved together with the transport belt 23, and the movement amount of the transport belt 23 can be repeatedly detected by the second detection portion 85.

In the present embodiment, the second detection unit 85 moves integrally with the gripping unit 80, and the scale unit 75.
However, a configuration in which the scale unit moves integrally with the gripping unit and the detection unit is fixed may be employed.
In the present embodiment, a so-called magnetic encoder that obtains the relative movement amount of the scale unit 75 and the second detection unit 85 by a change in the magnetic field is illustrated, but the optical encoder obtains the movement amount by an optical change. May be.

<Electrical configuration>
FIG. 5 is an electrical block diagram illustrating an electrical configuration of the printing apparatus. Next, the printing apparatus 100
The electrical configuration will be described with reference to FIG.

The printing apparatus 100 includes an input device 6 to which printing conditions and the like are input, a control unit 1 that controls each unit of the printing apparatus 100, and the like. As the input device 6, a desktop or laptop personal computer (PC) having a display unit 6a, a tablet terminal, a portable terminal, or the like can be used. The input device 6 may be provided separately from the printing device 100.

The control unit 1 includes an interface unit (I / F) 2 and a CPU (Central Processing Unit).
3, the memory | storage part 4, the control circuit 5, etc. are comprised. The interface unit 2 is for transmitting and receiving data between the input unit 6 that handles input signals and images and the control unit 1. The CPU 3 is an arithmetic processing unit for processing input signals from various detector groups 7 including the first and second detection units 92 and 85 and controlling the printing operation of the printing apparatus 100. For example, C
The PU 3 calculates the movement amount (first movement amount) of the transport belt 23 from the rotation amount of the belt driving roller 25 detected by the first detection unit 92. Further, the CPU 3 calculates the movement amount (second movement amount) of the transport belt 23 from the relative movement amount with respect to the scale unit 75 detected by the second detection unit 85.
The storage unit 4 is a storage medium for securing an area for storing a program of the CPU 3, a work area, and the like, and includes a RAM (Random Access Memory), an EEPROM (Electrically Erasabl).
(e Programmable Read Only Memory).

The control unit 1 controls the drive of the ejection head provided in the head unit 42 by the control signal output from the control circuit 5 to eject ink toward the medium 95. The control unit 1 controls the drive of the motor provided in the carriage moving unit 45 by a control signal output from the control circuit 5 to move the carriage 43 on which the head unit 42 is mounted in the main scanning direction (Y-axis direction). Move back and forth. The control unit 1 controls the drive of the motor provided in the belt driving roller 25 by the control signal output from the control circuit 5 to rotate and move the conveyance belt 23. As a result, the medium 95 placed on the transport belt 23 is moved in the transport direction (+ X-axis direction).

A main scan in which the control unit 1 controls the carriage moving unit 45 and the head unit 42 to move the head unit 42 (carriage 43) while discharging ink from the discharge head;
An image or the like is formed on the medium 95 by a printing operation in which the belt drive roller 25 is controlled to perform sub-scanning in which the medium 95 is conveyed in the conveyance direction.

The control unit 1 switches the gripping unit 80 between a gripping state and a non-holding state by controlling a current flowing through the electromagnet provided in the switching unit 74 according to a control signal output from the control circuit 5. The control unit 1 controls the moving mechanism of the lever moving unit 77 by the control signal output from the control circuit 5 to reciprocate the moving lever 78 along the transport direction. The control unit 1 controls each device (not shown).

<Conveying belt slip detection method>
FIG. 6 is a flowchart for explaining a method for detecting slippage of the conveyor belt. Next, a method for detecting slippage of the conveyor belt 23 in the printing operation of the printing apparatus 100 will be described with reference to FIG.

Step S1 is a print information receiving step for receiving print data. The control unit 1 receives input of print data or print information for recording an image on the medium 95 from the input device 6, and stores it in the storage unit 4.

Step S <b> 2 is a gripping process in which the gripping unit 80 is gripped by the transport belt 23. Control unit 1
The current flows through the electromagnet of the switching unit 74 to generate a magnetic force in the electromagnet. As a result, the gripping unit 80 enters a gripping state and grips the transport belt 23.

Step S3 is a sub-scanning step for moving the transport belt 23 in the transport direction. Control unit 1
Controls the motor 25 a of the belt driving roller 25 based on the second movement amount calculated from the signal output from the second detection unit 85 as the transport belt 23 moves. The control unit 1 controls the motor 25 a of the belt driving roller 25 to move the gripping unit 80 in the gripping state together with the transport belt 23. Then, according to the movement amount detected by the second detection unit 85, the control unit 1 has the second position where the gripping unit 80 is located on the downstream side in the transport direction from the first position (initial position). The rotation of the conveyor belt 23 is stopped. This
The medium 95 placed on the transport belt 23 is transported in the transport direction. In the first sub-scanning step, the interval between the first position and the second position is a carry amount up to a predetermined position where the printing operation is started. In the second and subsequent sub-scanning steps, the interval between the first position and the second position is the amount of line feed during the printing operation.

Step S <b> 4 is a slip amount calculating step for calculating the slip amount of the transport belt 23. A belt driving roller 25 and a conveyor belt that rotate and move the conveyor belt 23 when the conveyor belt 23 is repeatedly used while being rotated and the conveyor belt 23 extends or the inner peripheral surface 23b of the conveyor belt 23 wears. There is a case where slippage occurs between the two. For this reason, the control unit 1
After the movement (conveyance) of the conveyance belt 23 is stopped, the movement amount (first movement amount) and the second detection of the conveyance belt 23 obtained from the rotation amount of the belt driving roller 25 detected by the first detection unit 92 are detected. The difference from the movement amount (second movement amount) of the conveyor belt 23 detected by the unit 85 is calculated.

Since the second detector 85 moves with the conveyor belt 23, the second detector 85 detects the second.
The movement amount indicates the actual movement amount of the transport belt 23. On the other hand, the first movement amount of the conveyance belt 23 obtained from the rotation amount of the belt driving roller 25 detected by the first detection unit 92 includes the belt driving roller 25 and the conveyance belt 23 in addition to the actual movement amount of the conveyance belt 23. The amount of slippage between is included. That is, when slippage occurs between the belt driving roller 25 and the conveyor belt 23, the first movement amount is larger than the second movement amount (actual movement amount). By calculating the difference between the first movement amount and the second movement amount, it is possible to detect whether or not the conveyor belt 23 slips.

In step S5, the difference between the first movement amount of the conveyance belt 23 obtained from the rotation amount of the belt driving roller 25 detected by the first detection unit 92 and the second movement amount of the conveyance belt 23 detected by the second detection unit 85. Is a determination step of determining whether or not the reference value is greater than or equal to the reference value. Thereby, the control unit 1
Can detect that slippage of a reference value or more has occurred between the conveyor belt 23 and the belt driving roller 25. When the difference between the first movement amount and the second movement amount is greater than or equal to the reference value (step S
5: Yes), the process proceeds to step S6. When the difference between the first movement amount and the second movement amount is less than the reference value (step S5: No), the process proceeds to step S7. The reference value is set in consideration of the maintenance frequency and production efficiency of the printing apparatus 100.

Step S6 is a warning process for warning the user. The control unit 1 performs a warning operation when the difference between the first movement amount and the second movement amount is equal to or greater than a reference value. As a result, it is possible to notify the user that slippage exceeding the reference value has occurred between the transport belt 23 and the belt drive roller 25.
The warning operation is an operation for notifying that the maintenance time of the apparatus is near because a slip more than a reference value has occurred between the conveyor belt 23 and the belt driving roller 25. The control unit 1 displays a message such as “The belt slip amount is increasing. Printing is possible, but maintenance is recommended” on the display unit 6a of the input device 6 via the interface unit 2. . Accordingly, it is possible to notify the user that the printing apparatus 100 is approaching the time when maintenance is required. In the present embodiment, the warning operation is described as displaying a message on the display unit 6a of the input device 6. However, the printing apparatus includes a notification unit that performs a warning operation, and emits sound, light, or the like from the notification unit. Thus, the user may be notified of the warning.

Even when the difference between the first movement amount and the second movement amount is equal to or larger than the reference value, the control unit 1 determines the medium 95.
Continue printing on. Even if the slip amount between the transport belt 23 and the belt driving roller 25 is equal to or greater than the reference value, the travel amount (transport amount) of the transport belt 23 is the actual travel amount (second value) detected by the second detector 85. Therefore, this influence does not immediately affect the printing operation or the print image quality. After performing the warning operation in step S6, the control unit 1 returns to step S7 and continues the printing operation. The user can improve the production efficiency of the printing apparatus 100 by performing maintenance of the printing apparatus 100 when the medium 95 or the printing type is switched.

Step S <b> 7 is a main scanning step for ejecting ink toward the medium 95. The control unit 1 controls the head unit 42 and the carriage moving unit 45 to move the carriage 43 on which the head unit 42 is mounted from the head unit 42 while moving it in the width direction (Y-axis direction) of the medium 95 intersecting the transport direction. Main scanning is performed to eject ink toward the medium 95.

Step S <b> 8 is a non-gripping step for bringing the gripping portion 80 gripping the transport belt 23 into a non-gripping state. The control unit 1 interrupts the current flowing in the electromagnet of the switching unit 74 and demagnetizes the magnetic force of the electromagnet. Thereby, the holding part 80 will be in a non-holding state.

Step S9 is a return process for returning the return unit 76 to the upstream side in the transport direction. The control unit 1
The lever moving unit 77 is controlled to move the moving lever 78 waiting at a predetermined position downstream of the gripping unit 80 in the transport direction to the upstream side of the transport direction. As a result, the grip portion 80 and the moving lever 78 come into contact with each other, and the grip portion 80 in the non-grip state located at the second position is returned to the first position. Thereby, the gripping portion 80 in the gripping state can be repeatedly moved from the first position to the second position together with the transport belt 23. Thereafter, the moving lever 78 is moved downstream in the transport direction from the second position, and waits at a predetermined position. For convenience of explanation, the steps from the main scanning process in step S7 to the returning process in step S9 have been described as different steps. However, steps S8 and S9 are performed substantially simultaneously with step S7.

Step S10 is a print data confirmation step for confirming whether there is print data for the next line.
The control unit 1 refers to the print data stored in the storage unit 4 and confirms whether there is print data for the next line. If there is print data for the next line (step S10: Yes), step S2
Return to step S2 to repeat step S10. As a result, main scanning and sub-scanning are repeated, and an image or the like is printed on the medium 95. When there is no print data for the next line (step S1
0: No), the control unit 1 ends the printing operation of the printing apparatus 100.

In the present embodiment, the flow of performing the returning process for each sub-scanning process and main scanning process is shown. However, after the sub-scanning process and the main scanning process are repeated a plurality of times, the gripping unit 80 is moved a plurality of times. It is good also as a flow which returns the movement amount which moved to one return process.

As described above, according to the printing apparatus 100 according to the present embodiment, the following effects can be obtained.
The printing apparatus 100 detects the amount of movement relative to the first detection unit 92 that detects the rotation amount of the belt driving roller 25 that rotates and moves the conveyance belt 23 and the scale unit 75 that is provided along the conveyance direction. And a second detection unit 85. Since the second detection unit 85 is provided in the gripping unit 80 that grips the transport belt 23 and moves with the transport belt, the second detection unit 85 detects the travel amount (actual travel amount) of the transport belt. The printing apparatus 100 includes the first movement amount that is the movement amount of the conveyance belt 23 obtained from the rotation amount of the belt driving roller 25 detected by the first detection unit 92, and the conveyance detected by the second detection unit 85. A control unit 1 is provided for determining whether or not the difference from the second movement amount, which is the actual movement amount of the belt, is greater than or equal to a reference value. Since the first movement amount includes the slip amount between the conveyance belt 23 and the belt driving roller 25, the printing apparatus 1
00 detects whether slip has occurred between the conveyance belt 23 and the belt driving roller 25 by determining whether or not the difference between the first movement amount and the second movement amount is equal to or greater than a reference value. be able to.

The control unit 1 of the printing apparatus 100 performs a warning operation when the difference between the first movement amount and the second movement amount is equal to or greater than a reference value. As a result, it is possible to notify the user that slippage has occurred between the transport belt 23 and the belt driving roller 25.
Even if slip occurs between the conveyance belt 23 and the belt driving roller 25, the control unit 1 continues the printing operation even after performing a warning operation that warns that the slip has occurred. Based on this warning, when the user performs maintenance of the printing apparatus 100 when the medium 95 or the printing type is switched, it is possible to suppress a decrease in production efficiency of the printing apparatus 100.
Since the grip unit 80 grips the transport belt 23 on the upstream side in the transport direction from the printing unit 40,
A portion where the conveyor belt 23 is easy to loosen can be set in a short range. Thereby, it is possible to prevent slippage between the belt driving roller 25 and the conveyor belt 23.

The slip detection method of the conveyance belt 23 in the printing apparatus 100 includes a first movement amount that is a movement amount of the conveyance belt 23 obtained from the rotation amount of the belt driving roller 25 detected by the first detection unit 92, and a second detection unit. A determination step of determining whether or not the difference from the second movement amount, which is the movement amount (actual movement amount) of the conveyor belt 23 detected in step S1, is greater than or equal to a reference value. Since the first movement amount includes the slip amount between the conveyance belt 23 and the belt driving roller 25, according to the slip detection method of the conveyance belt 23, the difference between the first movement amount and the second movement amount is calculated. By determining whether or not the value is greater than or equal to the reference value, it is possible to detect that slip has occurred between the conveyance belt 23 and the belt driving roller 25.

(Modification 1)
FIG. 7 is a flowchart illustrating a method for detecting slippage of the conveyor belt according to the first modification. The slip detection method for the conveyor belt 23 of the printing apparatus 100 described in this modification stores the difference (slip amount) between the first movement amount and the second movement amount in time series, and further stores the slip amount stored before and after. A difference from the embodiment is that a warning operation is performed when the amount of change exceeds a reference value.

Hereinafter, a slip detection method for the conveyance belt 23 in the printing operation of the printing apparatus 100 according to the first modification will be described with reference to FIG. Note that the configuration of the printing apparatus 100 according to the present modification is the same as that of the embodiment, and a description thereof will be omitted. In the flowchart shown in FIG. 7, steps S101 to S103 are the same as steps S1 to S3 described in the embodiment.
Step S108 to step S111 are the same as step S described in the embodiment.
Since it is the same as 7-step S10, the description is abbreviate | omitted.

Step S <b> 104 is a slip amount calculation storage step for calculating and storing the slip amount of the transport belt 23. When the number of times the transport belt 23 transports the medium 95 (the number of sub-scans) is n, the control unit 1 determines the first speed of the transport belt 23 obtained from the rotation amount of the belt driving roller 25 detected by the first detection unit 92. The difference between the first movement amount and the second movement amount (actual movement amount) of the conveyor belt 23 detected by the second detection unit 85 is calculated and stored in the storage unit 4 as the nth slip amount. Further, the control unit 1 stores the difference between the first movement amount and the second movement amount when the medium 95 is transported before the nth slip amount is stored in the storage unit 4 as the n−1 slip amount. I remember it. Thereby, the change with time of the slippage between the conveyor belt 23 and the belt driving roller 25 can be confirmed.

Step S105 is a slip change amount calculating and storing step of calculating and storing a change amount of the slip amount of the transport belt 23. For example, the difference between the first movement amount and the second movement amount calculated by the first sub-scan (n = 1) is stored in the storage unit 4 as the first slip amount, and the second sub-scan (n = 2). The difference between the first movement amount and the second movement amount calculated by (1) is stored in the storage unit 4 as the second slip amount.
In the second sub-scanning (n = 2), the control unit 1 changes the second (n) slip amount with respect to the first (n−1) slip amount (second slip change amount = second slip amount− First slip amount) is calculated and stored in the storage unit 4.

Step S106 is a determination step of determining whether or not the n-th slip change amount, which is the change amount of the n-th slip amount with respect to the n-1 slip amount, is equal to or greater than a reference value. The control unit 1 performs step S105.
It is determined whether or not the amount of slip change between the conveyor belt 23 and the belt driving roller 25 calculated in step S is equal to or greater than a predetermined reference value. When the slip change amount is equal to or greater than a predetermined reference value (step S106)
: Yes) proceeds to step S107. When the slip change amount is less than the predetermined reference value (step S106: No), the process proceeds to step S108. The reference value is set in consideration of the maintenance frequency and production efficiency of the printing apparatus 100.

Step S107 is a warning process for warning the user. The control unit 1 performs a warning operation when the change amount of the n-th slip amount (the n-th slip change amount) with respect to the n-1 slip amount is equal to or greater than a reference value. Thereby, it is possible to notify the user before the slip amount between the conveyance belt 23 and the belt driving roller 25 becomes too large. And the control part 1 is step S
After a warning operation is performed at 107, the process returns to step S108 to continue the printing operation. Note that the content of the warning operation is the same as the content of the warning operation described in step S6 of the embodiment, and thus the description thereof is omitted.

According to the slip detection method for the transport belt 23 according to the first modification, the transport belt 23 and the belt drive roller 25 are determined by determining that the amount of change in slip between the transport belt 23 and the belt drive roller 25 is equal to or greater than a reference value. It is possible to detect that slip has occurred between the two. Even when slipping occurs, the control unit 1 continues the printing operation even after performing a warning operation that warns that slipping has occurred. Based on this warning, when the user performs maintenance of the printing apparatus 100 when the medium 95 or the printing type is switched, it is possible to suppress a decrease in production efficiency of the printing apparatus 100.

(Modification 2)
FIG. 8 is a flowchart for explaining a conveyance belt slip detection method according to the second modification. The slip detection method for the conveyor belt 23 of the printing apparatus 100 described in this modification is the conveyor belt 2.
The number of rotations of the belt driving roller 25 per one rotation is stored in time series, and a warning operation is performed when the amount of change in the number of rotations of the belt driving roller 25 stored before and after becomes more than the reference value. It is different from the form.

Hereinafter, a slip detection method for the conveyance belt 23 in the printing operation of the printing apparatus 100 according to the modification 2 will be described with reference to FIG. Note that the configuration of the printing apparatus 100 according to the present modification is the same as that of the embodiment, and a description thereof will be omitted. In the flowchart shown in FIG. 8, Step S201 and Step S202 are the same as Step S1 and Step S2 described in the embodiment, and Step S210 to Step S213 are the same as Step S7 to Step S10 described in the embodiment. Since it is the same, the description is abbreviate | omitted.

Step S203 is a sub-scanning start step for starting sub-scanning for moving the transport belt 23 in the transport direction. The control unit 1 moves the motor 2 of the belt driving roller 25 based on the second movement amount calculated from the signal output from the second detection unit 85 as the transport belt 23 moves.
5a is controlled. The control unit 1 controls the motor 25a of the belt driving roller 25 to move the gripping unit 80 in the gripping state together with the transport belt 23 from the first position (initial position) to the downstream side in the transport direction from the first position. Move towards position. Then, the control unit 1 accumulates the movement amount (actual movement amount) of the transport belt 23 by the second detection unit 85 and accumulates the rotation amount of the belt driving roller 25 by the first detection unit 92. Note that the interval between the first position and the second position in the first sub-scan is a carry amount to a predetermined position at which the printing operation is started. The interval between the first position and the second position in the second and subsequent sub-scans is a line feed amount during the printing operation.

In step S204, it is determined whether the transport belt 23 has made one revolution. The control unit 1 compares the integrated value of the actual movement amount of the transport belt 23 with the length of one round along the transport direction of the transport belt 23 stored in the storage unit 4, and the transport belt 23 makes one rotation. Determine whether. Conveyor belt 2
When 3 rotates once (step S204: Yes), the process proceeds to step S205. If the transport belt 23 has not made one rotation (step S204: No), the process proceeds to step S209.

Step S205 is a roller rotation amount calculation storing step for calculating and storing the rotation amount of the belt driving roller 25. When the number of rotations of the conveyance belt 23 is m, the control unit 1 counts the number of rotations of the conveyance belt by the second detection unit 85, and the first detection unit 92 detects the rotation of the conveyance belt 23 once. The rotation amount of the belt drive roller 25 thus calculated is calculated and stored in the storage unit 4 as the m-th rotation amount. Further, the control unit 1 stores the rotation amount of the belt driving roller 25 detected when the conveyance belt 23 makes one rotation before the m-th rotation amount is stored in the storage unit 4 as the m−1th rotation amount. doing.

Step S206 is a rotation change amount calculating and storing step of calculating and storing a rotation change amount that is a change amount of the rotation amount of the belt driving roller 25. For example, when the transport belt 23 makes two rotations (m = 2), the control unit 1 performs the second (m) rotation that is a change amount of the second (m) rotation amount with respect to the first (m−1) rotation amount. A change amount (second rotation change amount = second rotation amount-first rotation amount) is calculated and stored in the storage unit 4. If slip occurs between the belt drive roller 25 and the conveyor belt 23,
Since the rotation amount of the belt driving roller 25 gradually increases, it is predicted that the amount of slippage of the conveying belt 23 is increased by storing the rotation change amount of the belt driving roller 25 every time the conveying belt 23 makes one rotation. can do.

Step S207 is a determination step of determining whether or not the rotation change amount, which is the change amount of the m-th rotation amount with respect to the m−1 rotation amount, is equal to or greater than a reference value. The control unit 1 determines whether or not the rotation change amount of the belt driving roller 25 calculated in step S206 is greater than or equal to a reference value. When the rotation change amount is equal to or larger than the predetermined reference value (step S207: Yes), step S208 is performed.
Proceed to When the rotation change amount is less than the predetermined reference value (step S207: No), the process proceeds to step S209. In this way, by determining the amount of change in the rotation of the belt driving roller 25 for each rotation of the transport belt 23, it is possible to level the changes that occur at singular points such as the joints of the transport belt 23. The reference value is set in consideration of the maintenance frequency and production efficiency of the printing apparatus 100.

Step S208 is a warning process for warning the user. The control unit 1 performs a warning operation when the change amount of the m-th rotation amount (m-th rotation change amount) with respect to the m-1 rotation amount is equal to or greater than a reference value. Thereby, it is possible to notify the user before the slip amount between the conveyance belt 23 and the belt driving roller 25 becomes too large. And the control part 1 is step S
After performing a warning operation in 208, the process returns to step S209. Note that the content of the warning operation is the same as the content of the warning operation described in step S6 of the embodiment, and thus the description thereof is omitted.

Step S209 is a sub-scanning end process for ending the sub-scanning started in step S203. Based on the actual amount of movement of the conveyor belt 23 calculated by the second detector 85, the controller 1 stops driving the motor 25a of the belt driving roller 25 when the gripper 80 reaches the second position, and performs sub-scanning. Exit.

According to the slip detection method for the transport belt 23 according to the second modification, the transport belt 23 and the belt drive roller 25 are determined by determining that the rotation change amount of the belt drive roller 25 is equal to or greater than a reference value.
It is possible to detect that slip has occurred between the two. Even if the rotation change amount is equal to or greater than the reference value, the control unit 1 continues the printing operation even after performing a warning operation that warns that a slip has occurred. Based on this warning, when the user performs maintenance of the printing apparatus 100 when the medium 95 or the printing type is switched, it is possible to suppress a decrease in production efficiency of the printing apparatus 100.

DESCRIPTION OF SYMBOLS 1 ... Control part, 2 ... Interface part, 3 ... CPU, 4 ... Memory | storage part, 5 ... Control circuit, 6 ...
Input device, 6a ... display unit, 7 ... detector group, 10 ... medium supply unit, 20 ... medium transport unit, 23 ...
Conveying belt, 24 ... belt rotation roller, 25 ... belt drive roller, 25a ... motor, 27 ... drying unit, 30 ... medium recovery unit, 40 ... printing unit, 42 ... head unit, 43
... Carriage, 45 ... Carriage moving part, 50 ... Cleaning unit, 60 ... Medium contact part, 70
... belt moving amount measurement unit, 74 ... switching unit, 75 ... scale unit, 80 ... gripping unit, 83 ... elastic member, 84 ... ferromagnetic material, 85 ... second detection unit, 92 ... first detection unit, 93 ... rotary Scale, 95 ... medium, 100 ... printing device.

Claims (8)

A printing section for printing on a medium;
A conveyor belt for supporting the medium;
A driving roller that conveys the medium in a conveying direction by rotating the conveying belt;
A first detector for detecting the amount of rotation of the drive roller;
A scale portion provided along the transport direction;
A second detection unit for detecting a movement amount relative to the scale unit;
A gripping unit configured to move integrally with the scale unit or the second detection unit, and grips the transport belt and moves with the transport belt;
The difference between the first movement amount, which is the movement amount of the conveyor belt, obtained from the rotation amount detected by the first detection unit, and the second movement amount, which is the movement amount of the conveyance belt, detected by the second detection unit. A control unit for determining whether or not is greater than or equal to a reference value;
A printing apparatus comprising: The printing apparatus according to claim 1,
The control device performs a warning operation when it is determined that a difference between the first movement amount and the second movement amount is a reference value or more. The printing apparatus according to claim 1 or 2, wherein
The control unit continues the printing operation on the medium even when the difference between the first movement amount and the second movement amount is determined to be a reference value or more. The printing apparatus according to any one of claims 1 to 3,
When n is the number of times the transport belt transports the medium,
The controller is
The difference between the first movement amount and the second movement amount is stored as the n-th slip amount,
The difference between the first movement amount and the second movement amount when the medium is conveyed before the n-th slip amount is stored is stored as the n-1 slip amount. Printing device to do. The printing apparatus according to claim 4,
The controller is
A printing apparatus that performs a warning operation when it is determined that a change amount of the n-th slip amount with respect to the n-1 slip amount is a reference value or more. A printing apparatus according to any one of claims 1 to 5,
When m is the number of times the conveyor belt makes one rotation,
The controller is
Counting the number of rotations of the conveyor belt by the second detector;
Storing the rotation amount of the driving roller detected by the first detection unit when the conveyor belt makes one rotation as the m-th rotation amount;
Storing the rotation amount of the driving roller detected when the conveyor belt makes one rotation before the m-th rotation amount is stored as the m-1st rotation amount;
A printing apparatus that determines whether or not a change amount of the m-th rotation amount with respect to the m-1 rotation amount is equal to or greater than a reference value. The printing apparatus according to any one of claims 1 to 6,
The drive roller is provided on the downstream side in the transport direction from the printing unit,
The printing apparatus, wherein the gripping unit grips the transport belt on the upstream side in the transport direction with respect to the printing unit. A printing unit that performs printing on a medium, a conveyance belt that supports the medium, a driving roller that conveys the medium in a conveyance direction by rotating the conveyance belt, and a first amount that detects a rotation amount of the driving roller. A detection unit; a scale unit provided along the transport direction; a second detection unit that detects a movement amount relative to the scale unit; and the scale unit or the second unit.
A method for detecting slippage of a conveyor belt in a printing apparatus, comprising: a gripping unit configured to move integrally with a detector; and gripping the conveyor belt and moving with the conveyor belt;
The difference between the first movement amount, which is the movement amount of the conveyor belt, obtained from the rotation amount detected by the first detection unit, and the second movement amount, which is the movement amount of the conveyance belt, detected by the second detection unit. A method for detecting slippage of a conveyor belt, comprising: a determination step of determining whether or not is equal to or greater than a reference value.

Images