Printer, and determination method

Abstract

To frequently become incapable of obtaining adhesive force during printing onto a medium by a printer.SOLUTION: A printer comprises: a conveyor belt for conveying a printing medium attached onto an adhesive layer; a print head for performing printing with ink onto the conveyed printing medium; a washing part for washing the conveyor belt, that is located on a downstream side of the print head in a rotation direction of the conveyor belt; an imaging device for imaging the conveyor belt; and a control part. The control part performs subjecting the adhesive layer of the conveyor belt to printing a printing pattern with the print head; subjecting the washing part to washing the adhesive layer of the conveyor belt; subjecting the imaging device to imaging the printing pattern after washing; and determining deterioration of the adhesive layer, based on an imaging result of the printing pattern.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printing device and a determination method. [Background technology]

[0002] Patent Document 1 discloses a printer that uses an inkjet head to print on a recording medium that is transported by an adhesive transport belt. The printer is an example of a printing device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-107588 A Summary of the Invention [Problem to be solved by the invention]

[0004] The adhesive strength of the transport belt may deteriorate as the printing device is used. If the adhesive strength deteriorates, the transport belt may no longer be able to adhere to the medium during printing. [Means for solving the problem]

[0005] The printing device includes a conveyor belt having an adhesive layer and conveying a printing medium affixed to the adhesive layer, a print head that prints with ink on the printing medium conveyed by the conveyor belt, a cleaning unit located downstream of the print head in the rotation direction of the conveyor belt and cleans the conveyor belt, an imager that images the conveyor belt, and a control unit that controls the conveyor belt, the print head, the cleaning unit, and the imager, and the control unit performs the following operations: print a printing pattern on the adhesive layer of the conveyor belt using the print head, cause the cleaning unit to clean the adhesive layer of the conveyor belt, cause the imager to image the printing pattern after cleaning, and determine deterioration of the adhesive layer based on the imaged result of the printing pattern.

[0006] The determination method includes printing a printing pattern on a conveying belt with ink by ejecting ink from a print head toward an adhesive layer of the conveying belt having an adhesive layer, cleaning the conveying belt after printing the printing pattern, and determining deterioration of the adhesive layer based on the printing pattern after cleaning. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a schematic configuration of a printing apparatus. [Diagram 2] FIG. 1 is a block diagram illustrating a schematic configuration of a printing apparatus. [Diagram 3] FIG. 4 is a plan view illustrating an example of a print pattern. [Figure 4] 5A and 5B are diagrams for explaining ink amounts of a plurality of test patterns. [Diagram 5] FIG. 13 is a diagram for explaining a plurality of test patterns after cleaning. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] As shown in FIG. 1, the printing device 1 includes a medium transport unit 2, a medium contact unit 3, a printing unit 4, a drying unit 5, a cleaning unit 6, an image sensor 7, and a control circuit 8. Each unit of the printing device 1 is attached to a frame F. FIG. 1 is labeled with an X-axis, a Y-axis, and a Z-axis. The X-axis, the Y-axis, and the Z-axis are mutually orthogonal coordinate axes. The X-axis, the Y-axis, and the Z-axis are also labeled as necessary for the figures shown below. In this case, the X-axis, the Y-axis, and the Z-axis in each figure correspond to the X-axis, the Y-axis, and the Z-axis in FIG. 1. FIG. 1 shows a state in which the printing device 1 is disposed on an XY plane defined by the X-axis and the Y-axis. In this embodiment, the state in which the printing device 1 is disposed on the XY plane with the XY plane aligned with a horizontal plane is the usage state of the printing device 1. The posture of the printing device 1 when the printing device 1 is disposed on the XY plane aligned with the horizontal plane is called the usage posture of the printing device 1.

[0009] The X-axis, Y-axis, and Z-axis may be indicated in diagrams and explanations showing components and units of the printing device 1. In such cases, the X-axis, Y-axis, and Z-axis refer to the state in which the components and units are incorporated into the printing device 1. The orientation of each component or unit in the usage orientation of the printing device 1 is referred to as the usage orientation of that component or unit. In the following explanations of the printing device 1 and its components, units, etc., unless otherwise specified, the explanations will be in each usage orientation.

[0010] In addition, in a scene where the printing device 1 is actually used, the horizontal plane may be a substantially horizontal plane. The substantially horizontal plane includes, for example, an inclination within an inclination range that is permissible for the surface on which the printing device 1 is placed when used. For this reason, the substantially horizontal plane is not limited to, for example, a surface such as a highly accurate surface plate. The substantially horizontal plane includes, for example, various surfaces such as a desk, stand, shelf, and floor on which the printing device 1 is placed when used. In addition, the vertical direction is not strictly limited to the distance along the direction of gravity, and also includes the perpendicular direction to the substantially horizontal plane. For this reason, when the substantially horizontal plane is, for example, a surface such as a desk, stand, shelf, or floor, the vertical direction refers to the perpendicular direction to these surfaces.

[0011] The X-axis, Y-axis, and Z-axis are each marked with an arrow. For each of the X-axis, Y-axis, and Z-axis, the direction of the arrow indicates the + (positive) direction, and the direction opposite to the arrow indicates the - (negative) direction. The Z-axis is an axis perpendicular to the XY plane. When the printing device 1 is in use, the +Z direction is the vertically upward direction. When the printing device 1 is in use, in FIG. 1, the -Z direction is the vertically downward direction.

[0012] The medium transport unit 2 transports the medium P along the transport path. The medium P is an example of a print medium. The medium transport unit 2 includes a medium supply unit 10, a plurality of transport rollers 11, a transport belt 12, a rotating roller 13, a driving roller 14, and a medium recovery unit 15. When the plurality of transport rollers 11 are individually identified, the plurality of transport rollers 11 are represented as transport roller 11A, transport roller 11B, transport roller 11C, and transport roller 11D, respectively. The medium supply unit 10 supplies the medium P to the transport belt 12. As the medium P, for example, a woven fabric or nonwoven fabric made of natural fibers, cotton, silk, hemp, mohair, wool, cashmere, regenerated fibers, synthetic fibers, nylon, polyurethane, polyester, or a blend thereof can be used. A pretreatment agent for promoting color development and fixation may be applied to the woven fabric or nonwoven fabric.

[0013] The medium supply unit 10 has a supply shaft 17 and a bearing unit 18. A strip-shaped medium P is wound in a roll around the supply shaft 17. The bearing unit 18 rotatably supports both ends of the supply shaft 17. Furthermore, the medium supply unit 10 has a motor (not shown). The supply shaft 17 is driven to rotate by the power of the motor. The medium P is sent out by the supply shaft 17 being driven to rotate. The transport rollers 11A and 11B relay the medium P sent out from the medium supply unit 10 to the transport belt 12.

[0014] The conveyor belt 12 conveys the medium P facing the printing unit 4 in the conveying direction. The conveyor belt 12 is an endless belt formed by connecting both ends of a band-shaped belt. The conveyor belt 12 is an endless belt. The conveyor belt 12 is stretched between a rotating roller 13 and a driving roller 14. The conveyor belt 12 is held in a state in which a predetermined tension is applied. An adhesive layer 21 that adheres the medium P is provided on the surface 12A of the conveyor belt 12. The surface 12A of the conveyor belt 12 is the outer peripheral surface of the conveyor belt 12 formed in a ring shape. The back surface of the surface 12A is called the inner peripheral surface 12B. The conveyor belt 12 supports the medium P attached to the adhesive layer 21 at the medium contact section 3 described later. This allows a stretchable fabric or the like to be treated as the medium P.

[0015] The rotating roller 13 and the driving roller 14 are provided inside the conveyor belt 12 and support the inner circumferential surface 12B of the conveyor belt 12. The medium conveying unit 2 has a conveying motor (not shown). The driving roller 14 is driven to rotate by the power of the conveying motor. When the driving roller 14 is driven to rotate, the conveyor belt 12 is driven to rotate. When the driving roller 14 is driven to rotate, the conveyor belt 12 rotates and moves, and the rotating roller 13 is rotated. As a result, the medium P supported by the conveyor belt 12 is conveyed in the conveying direction, and an image is formed on the medium P by the printing unit 4 provided between the rotating roller 13 and the driving roller 14.

[0016] When the drive roller 14 is driven to rotate, the conveyor belt 12 rotates in a counterclockwise direction as viewed in FIG. 1. The counterclockwise direction as viewed in FIG. 1 is the rotation direction of the conveyor belt 12. The direction from the rotating roller 13 toward the driving roller 14 along the conveying path of the medium P is the conveying direction of the medium P. In the conveying direction of the medium P, the rotating roller 13 is located upstream of the driving roller 14. On the other hand, in the rotation direction of the conveyor belt 12, which is an endless belt, a cleaning unit 6, which will be described later, is located downstream of the driving roller 14. From another perspective, in the rotation direction of the conveyor belt 12, which is an endless belt, the cleaning unit 6 is located upstream of the rotating roller 13.

[0017] The transport roller 11C peels the medium P on which the image has been formed from the transport belt 12. The transport rollers 11C and 11D relay the peeled medium P to the medium collection unit 15. The medium collection unit 15 collects the medium P. The medium collection unit 15 has a winding shaft 25 and a bearing unit 26. The winding shaft 25 winds the medium P into a roll. The bearing unit 26 rotatably supports both ends of the winding shaft 25. Furthermore, the medium collection unit 15 has a motor (not shown). The winding shaft 25 is driven to rotate by the power of the motor. The medium P is wound up by the winding shaft 25 being driven to rotate.

[0018] The medium contacting unit 3 is located upstream of the printing unit 4 in the transport direction of the medium P. The medium contacting unit 3 brings the medium P supplied onto the transport belt 12 into contact with the surface 12A of the transport belt 12. As described above, the surface 12A of the transport belt 12 is provided with an adhesive layer 21. The medium P is brought into contact with the adhesive layer 21 by the medium contacting unit 3. The medium contacting unit 3 has a pressure roller 31, a roller support unit 32, a roller receiving unit 33, and a pressure roller driving unit 34. The pressure roller 31 is formed in a cylindrical shape. The roller support unit 32 rotatably supports both ends of the pressure roller 31.

[0019] The roller receiving portion 33 receives the load of the pressure roller 31 via the conveyor belt 12. The pressure roller driving portion 34 drives the pressure roller 31. The pressure roller driving portion 34 rolls the pressure roller 31 in the conveying direction and in the direction opposite to the conveying direction. The medium P is pressed against the surface 12A of the conveyor belt 12 by the pressure roller 31. As a result, the medium P is brought into close contact with the adhesive layer 21.

[0020] The printing unit 4 is disposed above the conveyor belt 12. The printing unit 4 prints on the medium P on the conveyor belt 12. The printing unit 4 has a head 41, a carriage 42, a guide rail 43, and a guide rail 44. The head 41 is an example of a print head. The head 41 is mounted on the carriage 42. The guide rail 43 and the guide rail 44 guide the carriage 42. The guide rail 43 and the guide rail 44 each extend along the X-axis. The carriage 42 reciprocates along the X-axis. As the carriage 42 reciprocates along the X-axis, the head 41 reciprocates along the X-axis. The X-axis is defined as the direction in which the head 41 reciprocates.

[0021] The head 41 ejects ink toward the medium P. The head 41 has a plurality of nozzles formed therein. The ink is ejected from the plurality of nozzles. The ink includes color ink and treatment ink. The color ink includes, for example, cyan (C), magenta (M), yellow (Y), black (K), and other inks. The treatment ink includes, for example, pretreatment ink and post-treatment ink. The pretreatment ink is ink for pre-treatment of the medium P before printing with the color ink. The post-treatment ink is ink for post-treatment that is ejected on top of the printing with the color ink. The treatment ink includes, for example, ink that improves the fixation of the color ink and ink that improves the flexibility of the medium P.

[0022] The drying unit 5 is provided upstream of the take-up shaft 25 in the transport direction of the medium P. The drying unit 5 dries the medium P peeled off from the transport belt 12. The drying unit 5 includes a heater (not shown). As the heater, for example, an IR heater can be used. The drying unit 5 dries the ink that has permeated into the medium P in a short period of time by driving the heater.

[0023] The cleaning unit 6 is located downstream of the drive roller 14 in the rotation direction of the conveyor belt 12. The cleaning unit 6 can also be expressed as being located downstream of the head 41 in the rotation direction of the conveyor belt 12. The cleaning unit 6 is located on the opposite side of the conveyor belt 12 to the printing unit 4. The cleaning unit 6 is disposed between the drive roller 14 and the rotating roller 13. The cleaning unit 6 cleans the surface 12A of the conveyor belt 12. The cleaning unit 6 has a cleaning tank 46, a cleaning roller 47, and a blade 48. The cleaning tank 46 is a tank that stores a cleaning liquid. For example, a water-soluble solvent such as water or an alcohol aqueous solution is used as the cleaning liquid, and a surfactant or an antifoaming agent is added as necessary.

[0024] The cleaning roller 47 is accommodated in the cleaning tank 46. The cleaning roller 47 is rotatably supported inside the cleaning tank 46. An upper portion of the cleaning roller 47 protrudes from the cleaning tank 46. An upper portion of the cleaning roller 47 contacts the surface 12A of the conveyor belt 12. The cleaning unit 6 has a rotation drive unit that rotates the cleaning roller 47. When the cleaning roller 47 is rotated, the cleaning roller 47 slides against the surface 12A of the conveyor belt 12. This cleans the ink adhering to the conveyor belt 12 and the fibers of the fabric as the medium P. The blade 48 is located downstream of the cleaning roller 47 in the rotation direction of the conveyor belt 12. The blade 48 is accommodated in the cleaning tank 46. An upper end of the blade 48 protrudes from the cleaning tank 46. As the conveyor belt 12 rotates, the blade 48 slides against the conveyor belt 12, thereby removing the cleaning liquid remaining on the surface 12A of the conveyor belt 12.

[0025] The imaging sensor 7 is located downstream of the cleaning unit 6 in the rotation direction of the conveyor belt 12. The imaging sensor 7 is located on the opposite side of the conveyor belt 12 from the printing unit 4. The imaging sensor 7 is located upstream of the rotating roller 13 in the rotation direction of the conveyor belt 12. The imaging sensor 7 is an example of an imaging device. The imaging sensor 7 captures an image of the surface 12A of the conveyor belt 12. The image captured by the imaging sensor 7 is output to the control circuit 8. Note that imaging includes color measurement using a colorimeter or the like.

[0026] As shown in FIG. 2, the printing device 1 includes a communication interface 51, a control unit 52, a memory 53, a conveyance motor 54, a carriage motor 55, and an input receiving unit 56. The control unit 52 is an example of a control unit. In FIG. 2, the interface is denoted as I / F. The communication interface 51 is communicatively connected to an external device 60 such as a computer. The communication interface 51 communicates with the external device 60 according to a predetermined communication protocol. The form of communication may be either wired or wireless. The communication interface 51 includes, for example, a connection port for wired communication, an antenna for wireless communication, and an interface circuit. The communication interface 51 receives print data from the external device 60. The communication interface 51 transmits various data to the external device 60. The communication interface 51 outputs the print data received from the external device 60 to the control unit 52.

[0027] The control unit 52 is a controller that controls the printing device 1. The control unit 52 executes a control program stored in the memory 53 to centrally control the operation of the printing device 1. The control unit 52 is a processor. For example, a CPU or an MPU can be used as the processor. CPU is an abbreviation for Central Processing Unit. MPU is an abbreviation for Micro Processing Unit. The memory 53 is composed of RAM, ROM, etc. RAM is an abbreviation for Random Access Memory. ROM is an abbreviation for Read Only Memory. The RAM is used for temporary storage of various data, etc., and the ROM stores the control program for controlling the operation of the printing device 1, various setting data, etc. Threshold data 58 is stored in the memory 53.

[0028] The control unit 52 functions as various functional units by executing a control program stored in the memory 53. The control unit 52 includes, as functional units, a transport control unit 61, a carriage control unit 62, a discharge control unit 63, and a deterioration determination unit 64. The control unit 52 functions as the transport control unit 61, the carriage control unit 62, the discharge control unit 63, and the deterioration determination unit 64 by executing a control program stored in the memory 53. The transport control unit 61 controls the drive of the transport motor 54. The transport motor 54 generates power for transporting the medium P. The carriage control unit 62 controls the drive of the carriage motor 55. The carriage motor 55 generates power for reciprocating the carriage 42. The discharge control unit 63 controls the drive of the head 41. The print operation of the printing device 1 is controlled by the functions of the transport control unit 61, the carriage control unit 62, and the discharge control unit 63.

[0029] The deterioration determination unit 64 determines the deterioration of the adhesive layer 21 of the conveyor belt 12 based on the imaging result by the imaging sensor 7. The input receiving unit 56 receives input from the user. The input receiving unit 56 receives changes to the threshold value of the imaging result of the print pattern when determining the deterioration of the adhesive layer 21. The input receiving unit 56 can be, for example, an input device such as a touch panel. The input result by the user is transmitted from the input receiving unit 56 to the control unit 52.

[0030] In this embodiment, the user can input a threshold value for determining deterioration of the adhesive layer 21 of the conveyor belt 12 via the input receiving unit 56. When a threshold value for determining deterioration of the adhesive layer 21 of the conveyor belt 12 is input via the input receiving unit 56, the control unit 52 updates the threshold value data 58 in the memory 53 to the new threshold value data 58. The input receiving unit 56 is an example of a receiving unit. According to the printing device 1 having the input receiving unit 56, the user can change the threshold value of the imaging result of the print pattern when determining deterioration of the adhesive layer 21.

[0031] The function of the deterioration determination unit 64 is achieved by the control unit 52 implementing a determination method. The determination method includes printing a print pattern on the adhesive layer 21 of the conveyor belt 12 by the head 41. The print pattern is printed on the surface 12A of the conveyor belt 12 by the head 41 in a state where the medium P is not placed on the surface 12A of the conveyor belt 12. The conveyor control unit 61 controls the conveyor motor 54 to rotate the conveyor belt 12. The carriage control unit 62 controls the carriage motor 55 to reciprocate the carriage 42 along the X-axis. The discharge control unit 63 controls the head 41 to discharge ink from the head 41 onto the surface 12A of the conveyor belt 12. As a result, the print pattern is printed on the surface 12A of the conveyor belt 12.

[0032] The determination method includes cleaning the conveyor belt 12 after printing the print pattern. The cleaning of the conveyor belt 12 is performed by the control unit 52 controlling the cleaning unit 6. By cleaning the conveyor belt 12, the print pattern printed on the adhesive layer 21 of the conveyor belt 12 is also cleaned.

[0033] The determination method includes determining the deterioration of the adhesive layer 21 based on the printed pattern after cleaning of the conveyor belt 12. The deterioration of the adhesive layer 21 is determined based on how much of the printed pattern remains on the conveyor belt 12 after cleaning of the conveyor belt 12. In the printing device 1, the image sensor 7 detects the printed pattern remaining on the conveyor belt 12 after cleaning, and the deterioration of the adhesive layer 21 is determined based on the result. The determination of the deterioration of the adhesive layer 21 based on the detection result by the image sensor 7 is performed by the deterioration determination unit 64.

[0034] In the printing device 1, the imaging sensor 7 detects the density of the printed pattern remaining on the conveyor belt 12 after cleaning. The density result of the printed pattern detected by the imaging sensor 7 is sent to the control unit 52. The control unit 52 determines the deterioration of the adhesive layer 21 based on the density result of the printed pattern detected by the imaging sensor 7 using the function of the deterioration determination section 64. When it is determined that the density result of the printed pattern detected by the imaging sensor 7 is lower than the density threshold value indicated in the threshold data 58 stored in the memory 53, it is determined that the adhesive layer 21 has deteriorated.

[0035] When it is determined that the adhesive layer 21 has deteriorated, an alert is issued to prompt the user to update the adhesive layer 21. The alert to prompt the user to update the adhesive layer 21 is notified to the user by, for example, a display device or alarm device (not shown) provided in the printing device 1, or an external device 60. The user who recognizes the deterioration of the adhesive layer 21 can update the adhesive layer 21. The adhesive layer 21 can be updated, for example, by applying a paint containing an adhesive to the surface 12A of the conveyor belt 12. At this time, a method of applying a paint containing an adhesive to the surface 12A after peeling the deteriorated adhesive layer 21 from the surface 12A can be adopted. A method of applying a paint containing an adhesive to the surface 12A without peeling the deteriorated adhesive layer 21 from the surface 12A can also be adopted.

[0036] According to the printing device 1, the control unit 52 judges the deterioration of the adhesive layer 21 based on the image of the print pattern after cleaning the adhesive layer 21 of the conveyor belt 12. The user can grasp the deterioration of the adhesive layer 21 based on the judgment result by the control unit 52. According to this printing device 1, it is easy to avoid losing adhesive force during printing.

[0037] The method of determination is not limited to a method of determining the deterioration of the adhesive layer 21 based on the detection result by the imaging sensor 7. A method of visually determining the printed pattern remaining on the conveyor belt 12 after cleaning can also be adopted. A printed pattern suitable for visual determination will be described.

[0038] As shown in FIG. 3, the print pattern 71 includes a plurality of test patterns 72. In the example shown in FIG. 3, the print pattern 71 includes ten test patterns 72. When the ten test patterns 72 are individually identified, the plurality of test patterns 72 are each given a symbol with an alphabetical letter A to J added thereto. The ten test patterns 72 are ten patterns, namely test pattern 72A to test pattern 72J. In FIG. 3, of the ten test patterns 72, four patterns, namely test pattern 72D, test pattern 72E, test pattern 72F, and test pattern 72G, are omitted from the illustration.

[0039] In each test pattern 72 of the printing pattern 71, the color ink and the treatment ink are superimposed on each other. That is, in the printing pattern 71, each test pattern 72 is formed by ejecting the color ink and the treatment ink from the head 41. The order in which the color ink and the treatment ink are superimposed may be either first or second. A method of printing with the color ink and then superimposing the treatment ink on the color ink can be adopted. A method of printing with the treatment ink and then superimposing the color ink on the treatment ink can also be adopted. In the printing pattern 71, the treatment ink increases the fixation of the color ink. In the printing pattern 71, the multiple test patterns 72 have different amounts of ink from each other.

[0040] As shown in FIG. 4, the multiple test patterns 72 have different concentrations of treated ink. The concentration of treated ink is determined by the amount of treated ink ejected from head 41 per unit area. The multiple test patterns 72 have different amounts of treated ink ejected from head 41 per unit area. The multiple test patterns 72 have the same concentration of color ink. The concentration of color ink is determined by the amount of color ink ejected from head 41 per unit area. The multiple test patterns 72 have the same amount of color ink ejected from head 41 per unit area. The color of color ink is uniform in the multiple test patterns 72.

[0041] In the print pattern 71, the color ink densities of the multiple test patterns 72 are unified. In the example shown in FIG. 4, the color ink densities of the multiple test patterns 72 are unified at 50%. The treatment ink densities of the multiple test patterns 72 vary in stages for each test pattern 72. In the example shown in FIG. 4, the treatment ink density of test pattern 72A is 10%. The treatment ink density increases by 10% from test pattern 72A to test pattern 72J. The treatment ink density of the tenth test pattern 72J is 100%.

[0042] In this embodiment, the determination method includes determining the deterioration of the adhesive layer 21 based on the density of the multiple test patterns 72 after cleaning. Cleaning of the conveyor belt 12 is performed by the control unit 52 controlling the cleaning unit 6. By cleaning the conveyor belt 12, the multiple test patterns 72 of the printed pattern 71 printed on the adhesive layer 21 of the conveyor belt 12 are also cleaned. As described above, in the printed pattern 71, the fixability of the color ink is improved by the treated ink. In the printed pattern 71, the treated ink density is different for each test pattern 72. Therefore, as shown in FIG. 5, in the multiple test patterns 72 after cleaning of the conveyor belt 12, the density of the test pattern 72 is different for each test pattern 72.

[0043] This is because the fixability of the color ink varies for each test pattern 72 due to differences in the concentration of the processed ink. A test pattern 72 with a low processed ink concentration loses more color ink due to washing compared to a test pattern 72 with a high processed ink concentration. It has been found that the amount of color ink lost due to washing increases according to the degree of deterioration of the adhesive layer 21. By utilizing this effect, the deterioration of the adhesive layer 21 can be easily determined.

[0044] For example, the deterioration of the adhesive layer 21 can be determined based on whether the test pattern 72B has disappeared by visual inspection. In this case, the disappearance of the test pattern 72B by visual inspection can be regarded as a threshold for determining the deterioration of the adhesive layer 21. The threshold for determining the deterioration of the adhesive layer 21 can be arbitrarily determined by the user. According to this determination method, the density of the multiple test patterns 72 after cleaning can be used as an index for determining the deterioration of the adhesive layer 21. Since the deterioration of the adhesive layer 21 is determined based on the multiple test patterns 72 having different ink amounts, it is easy to determine by visual inspection. The number of the test patterns 72 in the printed pattern 71 is not limited to 10. The number of the test patterns 72 in the printed pattern 71 can be any number equal to or greater than 2.

[0045] The method of determining the density of the printed pattern 71 after cleaning is not limited to visual determination. It is also possible to employ a method of determining the deterioration of the adhesive layer 21 based on the result of detecting the density of the printed pattern 71 remaining on the conveyor belt 12 after cleaning by the imaging sensor 7. The processing of the deterioration determination unit 64 shown in FIG. 2 is not limited to processing by the control unit 52. The processing of the deterioration determination unit 64 may be performed by an external device 60 such as a computer. The external device 60 may be configured to include an input receiving unit 56. [Explanation of symbols]

[0046] 1...printing device, 2...medium transport section, 3...medium contact section, 4...printing section, 5...drying section, 6...cleaning section, 7...imaging sensor, 8...control circuit, 10...medium supply section, 11...transport roller, 11A...transport roller, 11B...transport roller, 11C...transport roller, 11D...transport roller, 12...transport belt, 12A...surface, 12B...inner surface, 13...rotating roller, 14...driving roller, 15...medium recovery section, 17...supply shaft, 18...bearing section, 21...adhesive layer, 25...winding shaft, 26...bearing section, 31...pressure roller, 32...roller support section, 33...roller receiving section, 34...pressure roller drive section, 41...head, 42...carriage, 43...guide rail, 44...guide rail, 4 6...cleaning tank, 47...cleaning roller, 48...blade, 51...communication interface, 52...control unit, 53...memory, 54...conveyor motor, 55...carriage motor, 56...input receiving unit, 58...threshold data, 60...external device, 61...conveyor control unit, 62...carriage control unit, 63...ejection control unit, 64...deterioration determination unit, 71...printed pattern, 72...test pattern, 72A...test pattern, 72B...test pattern, 72C...test pattern, 72D...test pattern, 72E...test pattern, 72F...test pattern, 72G...test pattern, 72H...test pattern, 72I...test pattern, 72J...test pattern, P...medium.

Claims

1. a conveyor belt having an adhesive layer and conveying a print medium attached to the adhesive layer; a print head that prints with ink on the print medium transported by the transport belt; a cleaning unit that is located downstream of the print head in a rotation direction of the conveyor belt and cleans the conveyor belt; an imager for imaging the conveyor belt; a control unit that controls the conveyor belt, the print head, the cleaning unit, and the imaging device; The control unit is printing a print pattern on the adhesive layer of the conveyor belt by the print head; causing the cleaning unit to clean the adhesive layer of the conveyor belt; causing the image capture device to capture an image of the printed pattern after cleaning; and determining deterioration of the adhesive layer based on an imaging result of the printed pattern. Printing device.

2. A reception unit that receives a change to a threshold value of the image capturing result of the print pattern when determining deterioration of the adhesive layer, The printing device of claim 1 .

3. printing a print pattern on a conveyor belt with ink by ejecting ink from a print head toward an adhesive layer of the conveyor belt; cleaning the conveyor belt after printing the print pattern; and determining deterioration of the adhesive layer based on the printed pattern after cleaning. Judgment method.

4. the print pattern includes a plurality of test patterns each having a different amount of ink; determining deterioration of the adhesive layer based on densities of the plurality of test patterns after cleaning; The method according to claim 3.

Images