Recording apparatus and cleaning mechanism

Abstract

The invention provides a recording apparatus and a cleaning mechanism capable of appropriately discharging cleaning liquid based on ink concentration. The recording apparatus includes: a conveyor belt; a recording unit that records an image on a medium by discharging pigment ink onto the medium; a cleaning mechanism that cleans the conveyor belt with a cleaning liquid, the cleaning mechanism having: a storage unit that stores the cleaning liquid; a first detection unit that detects the ink concentration of the black ink contained in the cleaning liquid stored in the storage unit; a second detection unit that detects the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage unit; the second detection unit detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid, the cleaning control unit determines a threshold value based on the ink concentration of the black ink detected by the first detection unit, and when the ink concentration of the pigment ink detected by the second detection unit is greater than or equal to the threshold value, the cleaning control unit controls the cleaning unit to clean the pigment ink when the ink concentration of the pigment ink detected by the second detection unit is greater than or equal to the threshold value. The cleaning liquid is discharged from the storage part.

Description

Technical Field

[0001] The invention relates to a recording device and a cleaning mechanism. Background Art

[0002] Patent document 1 describes a recording device having a cleaning mechanism, which uses a cleaning liquid to clean a conveyor belt for conveying a medium. In the cleaning mechanism, as the conveyor belt is cleaned, ink is mixed into the cleaning liquid. The cleaning mechanism detects the ink concentration of the cleaning liquid. When the ink concentration of the cleaning liquid is high, the cleaning mechanism discharges the cleaning liquid.

[0003] In the recording device described in Patent Document 1, the ink concentration is detected based on the amount of light transmitted through the cleaning liquid. However, the amount of light transmitted varies depending on the color of the ink contained in the cleaning liquid. For example, when the cleaning liquid contains black ink, the amount of light transmitted tends to be smaller than when the cleaning liquid does not contain black ink. Therefore, the recording device may not be able to properly discharge the cleaning liquid based on the ink concentration.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2008-213394 Summary of the invention

[0005] A recording device for solving the above-mentioned problems comprises: a conveyor belt for conveying a medium; a recording unit for recording an image on the medium by ejecting a pigment ink onto the medium conveyed by the conveyor belt; a cleaning mechanism for cleaning the conveyor belt with a cleaning liquid, wherein the pigment ink includes a black ink and an ink other than the black ink, and the cleaning mechanism comprises: a storage unit for storing the cleaning liquid; a first detection unit for detecting the ink concentration of the black ink contained in the cleaning liquid stored in the storage unit; a second detection unit for detecting the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage unit; and a cleaning control unit, wherein the second detection unit detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid, and the cleaning control unit determines a threshold value based on the ink concentration of the black ink detected by the first detection unit, and discharges the cleaning liquid from the storage unit when the ink concentration of the pigment ink detected by the second detection unit is greater than the threshold value.

[0006] A cleaning mechanism for solving the above-mentioned problem uses a cleaning liquid to clean a conveyor belt for conveying a medium, and the medium records an image by being sprayed with pigment ink including black ink and ink other than the black ink, and the cleaning mechanism comprises: a storage section for storing the cleaning liquid; a first detection section for detecting the ink concentration of the black ink contained in the cleaning liquid stored in the storage section; a second detection section for detecting the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage section; and a cleaning control section, wherein the second detection section detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid, and the cleaning control section determines a threshold value based on the ink concentration of the black ink detected by the first detection section, and discharges the cleaning liquid from the storage section when the ink concentration of the pigment ink detected by the second detection section is greater than the threshold value. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic diagram showing an embodiment of a recording device having a cleaning mechanism.

[0008] Figure 2 A schematic diagram showing a detection unit.

[0009] Figure 3 This is a graph showing the wavelength of light and the transmittance of pigment ink.

[0010] Figure 4 This is a graph showing the wavelength of light and the transmittance of pigment ink.

[0011] Figure 5 It is a graph showing the ink concentration and output level of pigment inks excluding black ink.

[0012] Figure 6 It is a graph showing the ink concentration and output level of pigment inks including black ink.

[0013] Figure 7 This is a graph showing the output level that varies according to the ink density of the black ink and the ink density of the pigment ink.

[0014] Figure 8 It is a schematic diagram showing a modification example of the detection flow path. DETAILED DESCRIPTION

[0015] Hereinafter, an embodiment of a recording device having a cleaning mechanism will be described with reference to the accompanying drawings. The recording device is, for example, an inkjet printer that records images such as text and photos by ejecting pigment ink onto a medium such as cloth or paper. Pigment ink is an ink in which a pigment is dispersed in a solvent. Pigment ink includes black ink and inks other than black ink. For example, pigment inks include cyan, yellow, magenta, red, orange, green, light black, and the like in addition to black.

[0016] Recording device

[0017] like Figure 1 As shown, the recording device 11 includes a recording unit 12. The recording unit 12 is configured to eject pigment ink onto the medium 99. Thus, the recording unit 12 records an image on the medium 99. The recording unit 12 is a head. The recording unit 12 has a nozzle surface 14 in which one or more nozzles 13 are opened. The recording unit 12 ejects the pigment ink from the nozzles 13. The recording unit 12 may be a serial head that scans the medium 99. The recording unit 12 may also be a line head that can eject the pigment ink simultaneously across the width of the medium 99.

[0018] The recording device 11 includes a recording control unit 15. The recording control unit 15 controls the recording unit 12. The recording control unit 15 may also control a transport unit 21 described later.

[0019] The recording control unit 15 can be composed of one or more processors that perform various processes according to a computer program. The recording control unit 15 can also be composed of one or more dedicated hardware circuits such as a special-purpose integrated circuit that performs at least a part of the various processes. The recording control unit 15 can also be composed of a circuit including a combination of a processor and a hardware circuit. The processor includes a memory such as a CPU (Central Processing Unit), a RAM (Random Access Memory) and a ROM (Read Only Memory). The memory stores program codes or instructions that are configured to enable the CPU to perform processing. The memory, i.e., a computer-readable medium, includes all readable media that can be accessed by a general or special-purpose computer.

[0020] The recording device 11 includes a transport unit 21. The transport unit 21 is configured to transport the medium 99. While the transport unit 21 is transporting the medium 99, liquid is ejected from the recording unit 12 onto the medium 99.

[0021] The conveying unit 21 is configured to convey the medium 99 in the conveying direction A1. The conveying unit 21 has a plurality of conveying rollers. In one example, the conveying unit 21 has a first conveying roller 22 and a second conveying roller 23. The first conveying roller 22 is located upstream of the recording unit 12 in the conveying direction A1. The second conveying roller 23 is located downstream of the recording unit 12 in the conveying direction A1.

[0022] The conveying unit 21 has a driving source 24. The driving source 24 is, for example, a motor. The driving source 24 is connected to at least one of the plurality of conveying rollers. In one example, the driving source 24 is connected to the first conveying roller 22. The first conveying roller 22 is rotated by the driving source 24.

[0023] The conveying unit 21 has a conveyor belt 25. The conveyor belt 25 is hung on a plurality of conveyor rollers. In one example, the conveyor belt 25 is hung on the first conveyor roller 22 and the second conveyor roller 23. The conveyor belt 25 rotates along the first conveyor roller 22 and the second conveyor roller 23 by the driving source 24 to rotate the first conveyor roller 22. Figure 1 In the process, the conveyor belt 25 rotates counterclockwise. Thus, the conveyor belt 25 conveys the medium 99. The conveyor belt 25 supports the medium 99 on which the image is recorded by the recording unit 12.

[0024] The conveyor belt 25 includes a portion moving in the conveying direction A1 and a portion moving in the opposite direction A2 opposite to the conveying direction A1. The portion moving in the conveying direction A1 conveys the medium 99. The portion moving in the opposite direction A2 is cleaned by a cleaning mechanism 31 described below.

[0025] The conveyor belt 25 has an inner peripheral surface 26 and an outer peripheral surface 27. The inner peripheral surface 26 is a surface in contact with a plurality of conveyor rollers. In one example, the inner peripheral surface 26 is in contact with the first conveyor roller 22 and the second conveyor roller 23. The outer peripheral surface 27 is a surface in contact with the medium 99. Therefore, the outer peripheral surface 27 is a surface that supports the medium 99. The outer peripheral surface 27 is opposite to the nozzle surface 14.

[0026] The conveyor belt 25 is configured to be able to adhere to the medium 99. In detail, the medium 99 is adhered to the outer peripheral surface 27. Thus, the medium 99 is conveyed in a stable posture. In one example, the conveyor belt 25 is an adhesive belt coated with an adhesive. The adhesive is applied to the outer peripheral surface 27. In this case, the medium 99 is adhered to the outer peripheral surface 27 by the adhesive. Not limited to the adhesive, the medium 99 can be adhered to the outer peripheral surface 27 by, for example, suction force, electrostatic force, intermolecular force, etc. After the image is recorded by the recording unit 12, the medium 99 is peeled off from the outer peripheral surface 27, for example, by being pulled by other devices. The conveying unit 21 may have a peeling unit that peels off the medium 99 from the outer peripheral surface 27. In this case, the peeling unit is, for example, a roller around which the medium 99 is hung.

[0027] The conveying unit 21 may include a pressing unit 28. The pressing unit 28 is configured to press the medium 99 against the conveying belt 25. In one example, the pressing unit 28 is a roller. The pressing unit 28 presses the medium 99 against the conveying belt 25, and the medium 99 adheres to the outer peripheral surface 27.

[0028] In the conveyor belt 25, as the recording unit 12 records an image on the medium 99, pigment ink may adhere to the outer peripheral surface 27. If the conveyor belt 25 continues to convey the medium 99 with pigment ink adhered to the outer peripheral surface 27, the medium 99 may be contaminated.

[0029] The recording device 11 includes a cleaning mechanism 31. The cleaning mechanism 31 is configured to clean the conveyor belt 25 using a cleaning liquid. Specifically, the cleaning mechanism 31 cleans the outer peripheral surface 27 using the cleaning liquid. The cleaning mechanism 31 removes the pigment ink attached to the outer peripheral surface 27 using the cleaning liquid. The cleaning liquid makes it easier for the pigment ink to fall off the conveyor belt 25. In one example, the cleaning liquid is water.

[0030] Cleaning mechanism

[0031] The cleaning mechanism 31 includes a cleaning unit 32. The cleaning unit 32 cleans the conveyor belt 25 with a cleaning liquid. The cleaning unit 32 cleans the conveyor belt 25 by contacting the conveyor belt 25. Specifically, the cleaning unit 32 contacts the outer peripheral surface 27. The cleaning unit 32 contacts a portion of the conveyor belt 25 located in the opposite direction A2. That is, the cleaning unit 32 contacts the conveyor belt 25 after the medium 99 is peeled off.

[0032] The cleaning unit 32 has one or more cleaning rollers 33. In one example, the cleaning unit 32 has three cleaning rollers 33. The cleaning rollers 33 rotate while contacting the conveyor belt 25. The cleaning rollers 33 can rotate with respect to the conveyor belt 25. That is, the cleaning rollers 33 can rotate at any time. Figure 1 The cleaning roller 33 can also be driven to rotate in a manner that opposes the rotation of the conveyor belt 25. That is, the cleaning roller 33 can also be driven to rotate in a clockwise direction. Figure 1 In this case, the contact resistance between the cleaning roller 33 and the conveyor belt 25 becomes large, so it is easy to remove the pigment ink from the conveyor belt 25.

[0033] The cleaning roller 33 is in contact with the conveyor belt 25 while being wetted with the cleaning liquid. Thus, since the conveyor belt 25 is wetted with the cleaning liquid, the pigment ink can be easily removed from the conveyor belt 25. The cleaning roller 33 is, for example, a brush roller. The cleaning roller 33 may also be a sponge roller.

[0034] The cleaning section 32 has one or more cleaning blades 34. In one example, the cleaning section 32 has three cleaning blades 34. The cleaning blades 34 are in contact with the conveyor belt 25 moistened with the cleaning liquid. The cleaning blades 34 are in contact with the outer peripheral surface 27 moistened with the cleaning liquid. The cleaning blades 34 scrape off the pigment ink together with the cleaning liquid attached to the conveyor belt 25. The cleaning blades 34 come into contact with the conveyor belt 25 after the cleaning roller 33 comes into contact with the conveyor belt 25. Therefore, the cleaning blades 34 are located at a position in the opposite direction A2 than the cleaning roller 33.

[0035] The cleaning mechanism 31 includes a storage unit 35. The storage unit 35 is configured to store a cleaning liquid. The storage unit 35 holds the cleaning unit 32. The cleaning unit 32 uses the cleaning liquid stored in the storage unit 35 to clean the conveyor belt 25. The cleaning liquid stored in the storage unit 35 is gradually contaminated as the cleaning unit 32 cleans the conveyor belt 25. Therefore, the cleaning mechanism 31 needs to appropriately replace the cleaning liquid stored in the storage unit 35.

[0036] The storage unit 35 has a cleaning tank 36. The cleaning tank 36 is a tank for storing a cleaning liquid used in the cleaning unit 32. The cleaning tank 36 is provided so as to face the outer peripheral surface 27. The cleaning tank 36 holds the cleaning unit 32.

[0037] The cleaning tank 36 has an immersion tank 37. The immersion tank 37 is a tank for storing a predetermined amount of cleaning liquid. The immersion tank 37 holds the cleaning roller 33. The immersion tank 37 holds the cleaning roller 33 in such a manner that the cleaning roller 33 is immersed in the stored cleaning liquid. As the cleaning roller 33 cleans the conveyor belt 25, the pigment ink flows into the immersion tank 37.

[0038] The cleaning tank 36 has a supporting tank 38. The supporting tank 38 supports the dipping tank 37. Specifically, the supporting tank 38 accommodates the dipping tank 37. The supporting tank 38 receives the cleaning liquid overflowing from the dipping tank 37.

[0039] The support groove 38 supports the cleaning blade 34. The support groove 38 receives the cleaning liquid flowing down along the cleaning blade 34. The pigment ink flows into the support groove 38 as the cleaning blade 34 cleans the conveyor belt 25.

[0040] The storage unit 35 has a storage tank 39. The storage tank 39 is a tank connected to the cleaning tank 36. The storage tank 39 stores the cleaning liquid after the cleaning unit 32 is used and the cleaning liquid before the cleaning unit 32 is used.

[0041] The storage section 35 has a plurality of connecting flow channels. In one example, the storage section 35 has a first connecting flow channel 40 and a second connecting flow channel 41. The connecting flow channel is a flow channel connected to the cleaning tank 36 and the receiving tank 39. In detail, the first connecting flow channel 40 is connected to the support tank 38 and the receiving tank 39. The second connecting flow channel 41 is connected to the immersion tank 37 and the receiving tank 39. The cleaning liquid flows from the cleaning tank 36 to the receiving tank 39 through the first connecting flow channel 40. The cleaning liquid flows from the receiving tank 39 to the cleaning tank 36 through the second connecting flow channel 41. In this way, in the storage section 35, the cleaning liquid circulates between the cleaning tank 36 and the receiving tank 39. As a result, the concentration of the pigment ink contained in the cleaning liquid is easily uniform.

[0042] The storage section 35 has a detection channel 42. A cleaning liquid flows in the detection channel 42. The detection channel 42 detects the ink concentration through a detection unit 58 described later. The detection unit 58 is installed on the detection channel 42. The detection channel 42 can be the same channel as the connecting channel or a different channel from the connecting channel. In one example, the detection channel 42 constitutes a part of the first connecting channel 40. The detection channel 42 can also be a bypass channel installed on the connecting channel.

[0043] like Figure 2 As shown, the detection channel 42 has a first channel portion 43 and a second channel portion 44. The first channel portion 43 is a channel portion for detecting the ink concentration by a first detection unit 59 described later. The second channel portion 44 is a channel portion for detecting the ink concentration by a second detection unit 60 described later. In one example, the width of the first channel portion 43 is smaller than the width of the second channel portion 44.

[0044] The detection channel 42 may have a reflective sheet 45. The reflective sheet 45 is a sheet that reflects light. In one example, the reflective sheet 45 reflects infrared light. The reflective sheet 45 is a resin sheet of, for example, white or silver. The reflective sheet 45 is installed at the first channel portion 43. In one example, the reflective sheet 45 is installed on the outer peripheral surface of the first channel portion 43.

[0045] The detection channel 42 may have a light absorbing sheet 46. The light absorbing sheet 46 is a sheet that absorbs light. In one example, the light absorbing sheet 46 absorbs infrared light. The light absorbing sheet 46 is, for example, a sheet coated with carbon. The light absorbing sheet 46 is installed at the second channel portion 44. In one example, the light absorbing sheet 46 is installed on the outer peripheral surface of the second channel portion 44.

[0046] like Figure 1As shown, the cleaning mechanism 31 has a supply channel 47. The supply channel 47 is a channel for supplying cleaning liquid. New cleaning liquid is supplied to the cleaning mechanism 31 through the supply channel 47. The supply channel 47 is connected to the storage portion 35. In one example, the supply channel 47 is connected to the storage tank 39. The supply channel 47 is connected to a water pipe, for example. When the cleaning liquid in the storage portion 35 is reduced due to evaporation of the cleaning liquid, discharge of the cleaning liquid, etc., the cleaning liquid is supplied from the supply channel 47 to the storage portion 35.

[0047] The cleaning mechanism 31 includes a discharge flow channel 48. The discharge flow channel 48 is a flow channel for discharging the cleaning liquid. The cleaning liquid is discharged from the cleaning mechanism 31 through the discharge flow channel 48. In one example, the discharge flow channel 48 is connected to the storage tank 39. The discharge flow channel 48 is connected to, for example, a treatment device for treating waste liquid, a waste liquid tank for storing waste liquid, etc. In the case where the cleaning liquid is contaminated by the pigment ink, the cleaning liquid is discharged from the storage portion 35 through the discharge flow channel 48.

[0048] The cleaning mechanism 31 includes a pump 49. The pump 49 circulates the cleaning liquid in the storage portion 35. The pump 49 circulates the cleaning liquid between the cleaning tank 36 and the storage tank 39 through the first connecting flow channel 40 and the second connecting flow channel 41. In one example, the pump 49 is located on the second connecting flow channel 41. The pump 49 may also be located on the first connecting flow channel 40.

[0049] The cleaning mechanism 31 includes a flow meter 50. The flow meter 50 measures the flow rate of the cleaning liquid flowing in the storage portion 35. The flow meter 50 measures the flow rate of the cleaning liquid circulating between the cleaning tank 36 and the storage tank 39. The cleaning mechanism 31 controls the pump 49 based on the measurement result of the flow meter 50. In one example, the flow meter 50 is located on the second connecting flow channel 41. In detail, the flow meter 50 is located between the pump 49 and the storage tank 39 on the second connecting flow channel 41. The flow meter 50 may also be located on the first connecting flow channel 40.

[0050] The cleaning mechanism 31 includes a constant flow valve 51. The constant flow valve 51 is configured to maintain a constant flow rate of the cleaning liquid flowing in the storage portion 35. The constant flow valve 51 is a so-called throttle valve. The constant flow valve 51 maintains a constant flow rate of the cleaning liquid circulating between the cleaning tank 36 and the storage tank 39. In one example, the constant flow valve 51 is located on the second connecting flow channel 41. In detail, the constant flow valve 51 is located on the second connecting flow channel 41 between the pump 49 and the cleaning tank 36. The constant flow valve 51 may also be located on the first connecting flow channel 40.

[0051] The cleaning mechanism 31 has more than one opening and closing valve. In one example, the cleaning mechanism 31 has a first opening and closing valve 52, a second opening and closing valve 53, and a third opening and closing valve 54. The opening and closing valve is, for example, a solenoid valve. The first opening and closing valve 52 is located on the first connecting flow channel 40. By opening the first opening and closing valve 52, the cleaning liquid can flow from the cleaning tank 36 to the storage tank 39. The second opening and closing valve 53 is located on the supply flow channel 47. By opening the second opening and closing valve 53, the cleaning liquid is supplied to the storage section 35. The third opening and closing valve 54 is located on the discharge flow channel 48. By opening the third opening and closing valve 54, the cleaning liquid is discharged from the storage section 35.

[0052] The cleaning mechanism 31 may include a liquid amount sensor 55. The liquid amount sensor 55 is a sensor that measures the amount of cleaning liquid stored in the storage portion 35. In one example, the liquid amount sensor 55 measures the amount of cleaning liquid stored in the storage tank 39. The cleaning mechanism 31 can maintain the amount of cleaning liquid stored in the storage portion 35 at a fixed amount through the liquid amount sensor 55. For example, when the amount of cleaning liquid stored in the storage tank 39 is large, the cleaning mechanism 31 discharges the cleaning liquid through the discharge flow channel 48. When the amount of cleaning liquid stored in the storage tank 39 is small, the cleaning mechanism 31 supplies the cleaning liquid through the supply flow channel 47.

[0053] The cleaning mechanism 31 may include more than one filter. The cleaning mechanism 31 includes a cleaning filter 56 and a storage filter 57. The filter captures dust, fluff, etc. in the cleaning liquid. The cleaning filter 56 is installed in the first connecting flow channel 40. In detail, the cleaning filter 56 is located at the end connected to the cleaning tank 36 in the first connecting flow channel 40. The cleaning filter 56 captures foreign matter in the cleaning liquid flowing from the cleaning tank 36 to the storage tank 39. The storage filter 57 is installed in the first connecting flow channel 40. In detail, the storage filter 57 is located at the end connected to the storage tank 39 in the first connecting flow channel 40. The storage filter 57 captures foreign matter in the cleaning liquid flowing from the cleaning tank 36 to the storage tank 39.

[0054] The cleaning mechanism 31 includes a detection unit 58. The detection unit 58 is configured to detect the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage portion 35. The detection unit 58 detects the ink concentration of the cleaning liquid flowing in the detection flow channel 42. The cleaning mechanism 31 discharges the cleaning liquid when the ink concentration of the pigment ink contained in the cleaning liquid is large. If the ink concentration of the pigment ink contained in the cleaning liquid increases, the cleaning ability of the cleaning mechanism 31 decreases. By discharging the cleaning liquid when the ink concentration of the pigment ink contained in the cleaning liquid is large, the amount of cleaning liquid used can be reduced compared to a structure in which the cleaning liquid is continuously supplied.

[0055] In the storage section 35, pigments constituting the pigment ink are dispersed in the cleaning liquid. The detection unit 58 detects the ink concentration of the pigment ink by detecting the pigment dispersed in the cleaning liquid. The detection unit 58 optically detects the pigment dispersed in the cleaning liquid. There are a transmission method and a scattering method for optically detecting the pigment dispersed in the cleaning liquid. The transmission method is a method of detecting the pigment based on the amount of light transmitted through the cleaning liquid. That is, the transmission method is a method of utilizing the absorption of light by the pigment. The scattering method is a method of detecting the pigment based on the amount of scattered light scattered in the cleaning liquid. That is, the scattering method is a method of utilizing the reflection of light by the pigment.

[0056] like Figure 3 as well as Figure 4 As shown, in pigment ink, the transmittance, that is, the absorptivity with respect to the wavelength of light varies depending on the color of the pigment ink. Figure 3 as well as Figure 4 The graph shown indicates transmittance when a cleaning liquid containing a single color ink is irradiated with light. Figure 3 The black ink indicated by the two-dot chain line in FIG. 8 shows absorptivity regardless of the wavelength of light. Specifically, the black ink shows absorptivity for light with a wavelength of 300 nm to 1100 nm. Figure 3 The cyan ink indicated by the solid line in the figure shows absorption for light with a wavelength of 540 nm to 740 nm. Figure 3 The magenta ink indicated by the one-dot chain line in FIG. 1 shows absorption for light having a wavelength of 500 nm to 580 nm. Figure 3 The yellow ink indicated by the dotted line in the figure shows absorption for light with a wavelength of 340 nm to 500 nm. Figure 4 The red ink indicated by the solid line in the figure shows absorption for light with a wavelength of 300 nm to 620 nm. Figure 4 The orange ink indicated by the dotted line in the figure shows absorption for light with a wavelength of 300 nm to 580 nm. Figure 4 The green ink indicated by the single-dot chain line in FIG. 1 shows absorption for light having a wavelength of 580 nm to 780 nm. Figure 4 The light black ink indicated by the double-dashed line in the figure shows absorption for light with a wavelength of 300 nm to 780 nm.

[0057] The greater the ink concentration of the pigment ink, the smaller the amount of light transmitted through the cleaning liquid. On the other hand, the amount of light transmitted varies depending on the color of the pigment ink scattered in the cleaning liquid. This is because the wavelength region of light that exhibits absorption varies depending on the color of the pigment ink. That is, if light of a predetermined wavelength is irradiated to the cleaning liquid, the ink concentration of the color that exhibits absorption to the light can be detected, while on the other hand, the ink concentration of the color that does not exhibit absorption to the light cannot be detected. Therefore, it is difficult to detect the ink concentration of the pigment ink for a cleaning liquid containing pigments of multiple colors based on the amount of light transmitted.

[0058] Compared to the transmission method, in the scattering method, by using light in a wavelength region that is difficult for the pigment to absorb, the ink concentration of the pigment ink can be detected relatively independently of the color. For example, by using infrared light with a wavelength of 800nm ​​or more, the detection unit 58 can detect the ink concentration of the pigment ink for a cleaning liquid containing pigments of multiple colors. Therefore, the detection unit 58 detects the ink concentration of the pigment ink based on the amount of scattered light.

[0059] The greater the ink concentration of the pigment ink, the greater the amount of scattered light. On the other hand, the amount of scattered light varies depending on the color of the pigment ink scattered in the cleaning liquid. Specifically, when the ink concentration of the black ink contained in the cleaning liquid is high, the amount of scattered light decreases even though the ink concentration of the pigment ink is high. This is because black ink absorbs not only visible light but also infrared light.

[0060] like Figure 5 As shown in FIG. 1 , when the cleaning liquid does not contain black ink, there is a proportional relationship between the ink concentration and the output level. The output level is a level represented by the amount of scattered light. That is, the greater the ink concentration of the pigment ink, the greater the amount of scattered light.

[0061] like Figure 6 As shown in FIG. 1 , when the cleaning liquid contains black ink, there is a proportional relationship between the ink concentration and the output level, as in the case where the black ink is not contained. That is, the greater the ink concentration of the pigment ink, the greater the amount of scattered light. On the other hand, when the cleaning liquid contains black ink, the output level becomes smaller relative to the ink concentration compared to the case where the black ink is not contained.

[0062] like Figure 7 As shown in FIG. 1 , the higher the ink concentration of the black ink contained in the cleaning liquid is, the lower the output level is. That is, even if the ink concentration of the pigment ink contained in the cleaning liquid is the same, the amount of scattered light varies due to the difference in the ink concentration of the black ink. Therefore, it is difficult to uniquely determine the ink concentration of the pigment ink based on the amount of scattered light.

[0063] The corresponding relationship between the ink concentration of the pigment ink and the amount of scattered light is determined according to the ink concentration of the black ink. That is, the ink concentration of the pigment ink can be determined according to the amount of scattered light based on the ink concentration of the black ink. Therefore, the detection unit 58 detects the ink concentration of the black ink and the ink concentration of the pigment ink.

[0064] like Figure 2 As shown in FIG. 1 , the detection unit 58 includes a first detection unit 59 and a second detection unit 60. The first detection unit 59 is configured to detect the ink density of black ink. That is, the first detection unit 59 detects the ink density of black ink among the pigment inks of various colors used in the recording unit 12. The second detection unit 60 is configured to detect the ink density of pigment ink. That is, the second detection unit 60 detects the ink density of the pigment inks of multiple colors used in the recording unit 12.

[0065] The first detection unit 59 and the second detection unit 60 detect the ink concentration of the cleaning liquid stored in the storage unit 35. In one example, the first detection unit 59 and the second detection unit 60 detect the ink concentration of the cleaning liquid flowing in the first connecting flow channel 40. In this case, the first detection unit 59 and the second detection unit 60 detect the ink concentration of the cleaning liquid flowing out of the cleaning tank 36. Therefore, the first detection unit 59 and the second detection unit 60 can detect the ink concentration of the cleaning liquid used to clean the conveyor belt 25 with high accuracy. The first detection unit 59 and the second detection unit 60 can also detect the ink concentration of the cleaning liquid flowing in the second connecting flow channel 41.

[0066] The first detection unit 59 and the second detection unit 60 are optical sensors. The first detection unit 59 and the second detection unit 60 respectively include a light emitting unit and a light receiving unit. In detail, the first detection unit 59 includes a first light emitting unit 61 and a first light receiving unit 62. The second detection unit 60 includes a second light emitting unit 63 and a second light receiving unit 64. The light emitting unit includes a light emitting element. The light emitting unit includes, for example, an LED. The light emitting unit emits light of a predetermined wavelength. The light receiving unit includes an element that outputs a signal by receiving light. The light receiving unit includes, for example, a photodiode. The light receiving unit receives light emitted by the light emitting unit. The first light receiving unit 62 receives light emitted by the first light emitting unit 61. The second light receiving unit 64 receives light emitted by the second light emitting unit 63.

[0067] In order to detect the ink concentration of the black ink, the first detection unit 59 uses light of a wavelength that the black ink exhibits absorption and other inks do not exhibit absorption. In one example, the first light emitting unit 61 emits infrared light of a wavelength of 850 nm. The first light receiving unit 62 receives the transmitted light. Thus, the first detection unit 59 detects the ink concentration of the black ink.

[0068] In order to detect the ink concentration of the pigment ink including multiple colors, the second detection unit 60 uses light of a wavelength that the pigment ink of multiple colors does not show absorption. In one example, the second light emitting unit 63 emits infrared light with a wavelength of 850nm in the same manner as the first light emitting unit 61. The second light receiving unit 64 receives the scattered light. Thus, the second detection unit 60 detects the ink concentration of the pigment ink. The first light emitting unit 61 and the second light emitting unit 63 can be composed of a common LED.

[0069] The first detection unit 59 detects the ink concentration of the cleaning liquid flowing in the first flow channel portion 43. The first light emitting unit 61 emits light toward the first flow channel portion 43. The light is reflected by the reflective sheet 45 and then enters the first light receiving unit 62. Thus, the first detection unit 59 detects the transmitted light. The reflective sheet 45 eliminates the need for the first light emitting unit 61 and the first light receiving unit 62 to be opposed to each other across the first flow channel portion 43. That is, the first light emitting unit 61 and the first light receiving unit 62 do not need to be arranged across the first flow channel portion 43. In one example, the first light emitting unit 61 and the first light receiving unit 62 are arranged along the first flow channel portion 43. Thus, the reflective sheet 45 increases the degree of freedom regarding the positions of the first light emitting unit 61 and the first light receiving unit 62. In addition, since the width of the first flow channel portion 43 is relatively small, the optical path from the first light emitting unit 61 to the first light receiving unit 62 is small. Thus, the first detection unit 59 can detect a large amount of transmitted light. Therefore, the first detection unit 59 can detect the ink density of the black ink with high accuracy.

[0070] The second detection unit 60 detects the ink concentration of the cleaning liquid flowing in the second flow channel portion 44. The second light-emitting unit 63 and the second light-receiving unit 64 are arranged along the second flow channel portion 44. The second light-emitting unit 63 emits light toward the second flow channel portion 44. After the light is diffused in the cleaning liquid, it is incident on the second light-receiving unit 64. Thus, the second detection unit 60 detects the scattered light. The light is difficult to be reflected on the outer peripheral surface of the second flow channel portion 44 by the light-absorbing sheet 46. That is, the reflected light is difficult to be incident on the second light-receiving unit 64. Therefore, the second detection unit 60 can detect the scattered light with high accuracy. In addition, since the width of the second flow channel portion 44 is relatively large, the light emitted from the second light-emitting unit 63 is easily diffused by the pigment in the cleaning liquid. Thus, the second detection unit 60 can detect a large amount of scattered light. Therefore, the second detection unit 60 can detect the ink concentration of the pigment ink with high accuracy.

[0071] like Figure 1As shown, the cleaning mechanism 31 includes a cleaning control unit 65. The cleaning control unit 65 controls the cleaning mechanism 31. The cleaning control unit 65, like the recording control unit 15, can be composed of a processor, a hardware circuit, or a circuit including a combination thereof. The cleaning mechanism 31 can also be controlled by the recording control unit 15.

[0072] The cleaning control unit 65 determines the threshold value of the amount of scattered light based on the ink concentration of the black ink contained in the cleaning liquid. That is, the cleaning control unit 65 changes the threshold value based on the ink concentration of the black ink contained in the cleaning liquid detected by the first detection unit 59. The cleaning control unit 65 changes the threshold value in accordance with the amount of scattered light that changes according to the ink concentration of the black ink contained in the cleaning liquid, thereby determining whether the cleaning liquid is contaminated.

[0073] The cleaning control unit 65 stores the corresponding data D1. The corresponding data D1 is data that associates the ink concentration of the black ink with the threshold. The corresponding data D1 may be table data that indicates the correspondence between the ink concentration of the black ink and the threshold, or may be function data that derives the threshold based on the ink concentration of the black ink. The corresponding data D1 may also be stored by the recording control unit 15.

[0074] The cleaning control unit 65 determines the threshold value according to the detection result of the first detection unit 59 by referring to the corresponding data D1. For example, when the ink concentration of the black ink is the first concentration, the cleaning control unit 65 sets the first threshold value. When the ink concentration of the black ink is the second concentration, the cleaning control unit 65 sets the second threshold value. The higher the ink concentration of the black ink, the smaller the cleaning control unit 65 sets the threshold value.

[0075] The cleaning control unit 65 determines whether to discharge the cleaning liquid by comparing the detection result of the second detection unit 60 with the threshold value. When the ink concentration of the pigment ink is greater than the threshold value, the cleaning control unit 65 discharges the cleaning liquid from the storage unit 35. At this time, the cleaning control unit 65 discharges the cleaning liquid from the storage unit 35 by opening the third opening and closing valve 54. After the cleaning liquid is discharged, the cleaning control unit 65 opens the second opening and closing valve 53 to supply the cleaning liquid to the storage unit 35. In this way, the cleaning liquid is replaced.

[0076] The cleaning control unit 65 can judge whether the recording device 11 is in recording when discharging the cleaning liquid. The cleaning control unit 65 can judge whether the recording device 11 is in recording by communicating with the recording control unit 15. The cleaning control unit 65 can also judge whether the recording device 11 is in recording by accepting an operation from a user. When the recording device 11 is in recording, it is preferable that the cleaning liquid is stored in the cleaning tank 36. Therefore, when the recording device 11 is in recording, the cleaning control unit 65 opens the second opening and closing valve 53 while the first opening and closing valve 52 is closed, thereby discharging the cleaning liquid from the storage tank 39. Thereby, the cleaning liquid can be kept in the cleaning tank 36 and replaced in the storage tank 39.

[0077] Function and effect

[0078] Next, the operation and effects of the above-described embodiment will be described.

[0079] (1) The cleaning control unit 65 determines a threshold value based on the ink concentration of the black ink. The cleaning control unit 65 discharges the cleaning liquid from the storage unit 35 when the ink concentration of the pigment ink is above the threshold value. When the ink concentration of the black ink contained in the cleaning liquid is large, the amount of scattered light received by the second detection unit 60 becomes small. When the ink concentration of the black ink contained in the cleaning liquid is small, the amount of scattered light received by the second detection unit 60 becomes large. That is, even if the ink concentration of the pigment ink contained in the cleaning liquid is the same, if the ink concentration of the black ink is different, the amount of scattered light received by the second detection unit 60 will also be different. Therefore, it is difficult to grasp the ink concentration of the pigment ink based on the amount of scattered light. In view of this point, according to the above-mentioned structure, the threshold value is determined based on the ink concentration of the black ink. Therefore, even if the amount of scattered light received by the second detection unit 60 changes due to the ink concentration of the black ink, the ink concentration of the pigment ink can be grasped based on the amount of scattered light. Therefore, the cleaning mechanism 31 can appropriately discharge the cleaning liquid based on the ink concentration.

[0080] (2) The first detection unit 59 detects the ink concentration of the black ink by receiving the light transmitted through the cleaning liquid through the first light receiving unit 62. The second detection unit 60 detects the ink concentration of the pigment ink by receiving the light scattered in the cleaning liquid through the second light receiving unit 64. The pigment of the black ink absorbs light more easily than the pigments other than the black ink. Therefore, according to the above structure, the first detection unit 59 can detect the ink concentration of the black ink based on the amount of light transmitted through the cleaning liquid. Thus, the cleaning control unit 65 can appropriately determine the threshold value.

[0081] (3) The width of the first flow channel portion 43 is smaller than the width of the second flow channel portion 44. In order to increase the amount of light transmitted by the cleaning liquid, it is preferred that the width of the first flow channel portion 43 is smaller. In order to increase the amount of scattered light of the cleaning liquid, it is preferred that the width of the second flow channel portion 44 is larger. According to the above structure, the first detection unit 59 can easily detect the ink concentration of the black ink, and the second detection unit 60 can easily detect the ink concentration of the pigment ink.

[0082] (4) The detection channel 42 has a reflective sheet 45 that reflects the light emitted by the first light emitting unit 61 toward the first light receiving unit 62. According to the above structure, the first light receiving unit 62 can receive the transmitted light of the cleaning liquid without arranging the first light emitting unit 61 and the first light receiving unit 62 in a manner that the first channel portion 43 is sandwiched therebetween. Thus, the first light emitting unit 61 and the first light receiving unit 62 can be concentrated in one place.

[0083] (5) The detection channel 42 has a light absorbing sheet 46, and the light absorbing sheet 46 absorbs the light emitted by the second light emitting section 63. The light emitted by the second light emitting section 63 is sometimes reflected by the second channel portion 44. If the second light receiving section 64 receives the reflected light, the detection accuracy of the second detection section 60 is reduced. In view of this, according to the above-mentioned structure, since the reflected light can be reduced by the light absorbing sheet 46, the possibility of reducing the detection accuracy of the second detection section 60 can be reduced.

[0084] (6) The cleaning mechanism 31 includes a pump 49 that circulates the cleaning liquid between the cleaning tank 36 and the storage tank 39 through the first connecting flow channel 40 and the second connecting flow channel 41. According to the above structure, the ink concentration of the pigment ink contained in the cleaning liquid is easily uniform due to the circulation of the cleaning liquid. Therefore, the detection accuracy of the first detection unit 59 and the detection accuracy of the second detection unit 60 are improved.

[0085] (7) The first detection unit 59 detects the ink concentration of the black ink contained in the cleaning liquid flowing in the first connecting flow channel 40. The second detection unit 60 detects the ink concentration of the pigment ink contained in the cleaning liquid flowing in the first connecting flow channel 40. At the cleaning tank 36, the pigment ink is mixed into the cleaning liquid. Therefore, the ink concentration of the pigment ink contained in the cleaning liquid flowing in the first connecting flow channel 40 tends to become greater than the ink concentration of the pigment ink contained in the cleaning liquid flowing in the second connecting flow channel 41. The same is true for the ink concentration of the black ink. Therefore, according to the above-mentioned structure, the detection accuracy of the first detection unit 59 and the detection accuracy of the second detection unit 60 are improved.

[0086] (8) The purge control unit 65 determines the threshold value based on the ink density of the black ink by referring to the corresponding data D1. According to the above configuration, the purge control unit 65 can determine the threshold value relatively easily.

[0087] Change Example

[0088] The above-described embodiment can be implemented by being modified as follows. The above-described embodiment and the following modified examples can be implemented in combination with each other within the scope of no technical contradiction.

[0089] ·like Figure 8 As shown, the reflective sheet 45 and the light absorbing sheet 46 may also be located in the first flow channel portion 43 and the second flow channel portion 44. In this modification, the reflective sheet 45 and the light absorbing sheet 46 are located in the first flow channel portion 43 and the second flow channel portion 44 in a mutually attached state. The reflective sheet 45 and the light absorbing sheet 46 cause the detection flow channel 42 to branch into the first flow channel portion 43 and the second flow channel portion 44. The reflective sheet 45 and the light absorbing sheet 46 divide the first flow channel portion 43 and the second flow channel portion 44. The first flow channel portion 43 is a portion of the detection flow channel 42 that is opposite to the reflective sheet 45. The second flow channel portion 44 is a portion of the detection flow channel 42 that is opposite to the light absorbing sheet 46. In this modification, the first detection portion 59 and the second detection portion 60 are provided across the detection flow channel 42.

[0090] The first detection unit 59 and the second detection unit 60 may detect the cleaning liquid flowing in different connection channels. For example, the first detection unit 59 may detect the cleaning liquid flowing in the first connection channel 40, while the second detection unit 60 may detect the cleaning liquid flowing in the second connection channel 41. In this case, the first connection channel 40 and the second connection channel 41 each have a detection channel 42.

[0091] The first detection unit 59 is not limited to detecting the ink concentration of the black ink by the transmission method. For example, the first detection unit 59 may detect the ink concentration of the black ink by detecting the pH of the cleaning liquid. In this case, the black ink contains a component that changes the pH of the cleaning liquid. In addition, the first detection unit 59 is not limited to detecting the pH, and may detect the ink concentration of the black ink by detecting a component contained in the black ink from the cleaning liquid.

[0092] The liquid ejected by the recording unit 12 is not limited to ink, and may be, for example, a liquid in which particles of a functional material are dispersed or mixed in a liquid. For example, the recording unit 12 may eject a liquid containing a material such as an electrode material or a pixel material used in the manufacture of a liquid crystal display, an electroluminescent display, or a surface-emitting display in a dispersed or dissolved form.

[0093] Technical Thought

[0094] Hereinafter, the technical ideas and the effects thereof that can be grasped from the above-described embodiments and modified examples will be described.

[0095] (A) The recording device comprises: a conveyor belt that conveys a medium; a recording unit that records an image on the medium by ejecting pigment ink onto the medium conveyed by the conveyor belt; a cleaning mechanism that cleans the conveyor belt with a cleaning liquid, wherein the pigment ink includes a black ink and an ink other than the black ink, and the cleaning mechanism comprises: a storage unit that stores the cleaning liquid; a first detection unit that detects the ink concentration of the black ink contained in the cleaning liquid stored in the storage unit; a second detection unit that detects the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage unit; and a cleaning control unit, wherein the second detection unit detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid, and the cleaning control unit determines a threshold value based on the ink concentration of the black ink detected by the first detection unit, and discharges the cleaning liquid from the storage unit when the ink concentration of the pigment ink detected by the second detection unit is greater than the threshold value.

[0096] When the ink concentration of the black ink contained in the cleaning liquid is large, the amount of scattered light received by the second detection unit becomes smaller. When the ink concentration of the black ink contained in the cleaning liquid is small, the amount of scattered light received by the second detection unit becomes larger. That is, even if the ink concentration of the pigment ink contained in the cleaning liquid is the same, if the ink concentration of the black ink is different, the amount of scattered light received by the second detection unit will also be different. Therefore, it is difficult to grasp the ink concentration of the pigment ink based on the amount of scattered light. In view of this point, according to the above-mentioned structure, the threshold value is determined based on the ink concentration of the black ink. Therefore, even if the amount of scattered light received by the second detection unit changes due to the ink concentration of the black ink, the ink concentration of the pigment ink can be grasped based on the amount of scattered light. Therefore, the cleaning mechanism can appropriately discharge the cleaning liquid based on the ink concentration.

[0097] (B) In the above-mentioned recording device, it can also be set that the first detection unit has: a first light-emitting unit that emits light; a first light-receiving unit that receives the light emitted by the first light-emitting unit, and receives the light transmitted through the cleaning liquid through the first light-receiving unit to detect the ink concentration of the black ink, and the second detection unit has: a second light-emitting unit that emits light; a second light-receiving unit that receives the light emitted by the second light-emitting unit, and receives the light scattered in the cleaning liquid through the second light-receiving unit to detect the ink concentration of the pigment ink.

[0098] The pigment of black ink absorbs light more easily than pigments other than black ink. Therefore, according to the above structure, the first detection unit can detect the ink concentration of black ink based on the amount of light transmitted by the cleaning liquid. Thus, the cleaning control unit can appropriately determine the threshold value.

[0099] (C) In the above-mentioned recording device, it can also be set that the storage part has a detection flow channel for the flow of cleaning liquid, and the detection flow channel has a first flow channel part and a second flow channel part, the ink concentration is detected by the first detection part in the first flow channel part, and the ink concentration is detected by the second detection part in the second flow channel part, and the width of the first flow channel part is smaller than the width of the second flow channel part.

[0100] In order to increase the amount of light transmitted by the cleaning liquid, it is preferred that the width of the first flow channel portion is small. In order to increase the amount of scattered light of the cleaning liquid, it is preferred that the width of the second flow channel portion is large. According to the above structure, the first detection unit can easily detect the ink concentration of the black ink, and the second detection unit can easily detect the ink concentration of the pigment ink.

[0101] (D) In ​​the above-mentioned recording device, it can also be set that the storage part has a detection flow channel for the flow of cleaning liquid, and the detection flow channel has: a first flow channel part, in which the first detection part detects the ink concentration; a second flow channel part, in which the second detection part detects the ink concentration; and a reflective sheet, which reflects the light of the first light-emitting part toward the first light-receiving part, and the first light-emitting part and the first light-receiving part are arranged along the first flow channel part.

[0102] According to the above configuration, the first light receiving unit can receive the transmitted light of the cleaning liquid when the first light emitting unit and the first light receiving unit are not arranged to sandwich the first flow channel portion.

[0103] (E) In the above-mentioned recording device, it can also be set that the storage part has a detection flow channel for the flow of cleaning liquid, and the detection flow channel has: a first flow channel part, in which the first detection part detects the ink concentration; a second flow channel part, in which the second detection part detects the ink concentration; a light absorbing sheet, which absorbs the light emitted by the second light emitting part, and the second light emitting part and the second light receiving part are arranged along the second flow channel part.

[0104] The light emitted by the second light emitting unit is sometimes reflected by the second flow channel. If the second light receiving unit receives the reflected light, the detection accuracy of the second detection unit will be reduced. In view of this, according to the above structure, since the reflected light can be reduced by the light absorbing sheet, the possibility of reducing the detection accuracy of the second detection unit can be reduced.

[0105] (F) In the above-mentioned recording device, it can also be set that the storage part has a cleaning tank; a storage tank; a first connecting flow channel, which is connected to the cleaning tank and the storage tank; a second connecting flow channel, which is connected to the cleaning tank and the storage tank, and the cleaning mechanism has: a cleaning part, which uses the cleaning liquid stored in the cleaning tank to clean the conveyor belt; a pump, which circulates the cleaning liquid between the cleaning tank and the storage tank through the first connecting flow channel and the second connecting flow channel.

[0106] According to the above configuration, the ink concentration of the pigment ink contained in the cleaning liquid is easily made uniform by circulating the cleaning liquid, thereby improving the detection accuracy of the first detection unit and the detection accuracy of the second detection unit.

[0107] (G) In the above-mentioned recording device, it can also be set that the pump delivers the cleaning liquid from the cleaning tank through the first connecting flow channel to the receiving tank, and delivers the cleaning liquid from the receiving tank through the second connecting flow channel to the cleaning tank, the first detection unit detects the ink concentration of the black ink contained in the cleaning liquid flowing in the first connecting flow channel, and the second detection unit detects the ink concentration of the pigment ink contained in the cleaning liquid flowing in the first connecting flow channel.

[0108] In the cleaning tank, the pigment ink is mixed into the cleaning liquid. Therefore, the ink concentration of the pigment ink contained in the cleaning liquid flowing in the first connecting flow channel is likely to be greater than the ink concentration of the pigment ink contained in the cleaning liquid flowing in the second connecting flow channel. The same is true for the ink concentration of the black ink. Therefore, according to the above structure, the detection accuracy of the first detection unit and the detection accuracy of the second detection unit are improved.

[0109] (H) In the above-mentioned recording device, the cleaning control unit may store corresponding data that associates the ink concentration of the black ink with the threshold value, and determine the threshold value based on the ink concentration of the black ink by referring to the corresponding data. According to the above-mentioned structure, the cleaning control unit can determine the threshold value relatively easily.

[0110] (I) It may also be a cleaning mechanism that uses a cleaning liquid to clean a conveyor belt that conveys a medium, and the medium records an image by ejecting a pigment ink containing black ink and ink other than the black ink, and the cleaning mechanism has: a storage unit that stores the cleaning liquid; a first detection unit that detects the ink concentration of the black ink contained in the cleaning liquid stored in the storage unit; a second detection unit that detects the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage unit; a cleaning control unit, the second detection unit detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid, the cleaning control unit determines a threshold value based on the ink concentration of the black ink detected by the first detection unit, and when the ink concentration of the pigment ink detected by the second detection unit is greater than the threshold value, the cleaning liquid is discharged from the storage unit. According to the above structure, the same effect as the recording device can be obtained.

[0111] Explanation of symbols

[0112] 11…recording device; 12…recording unit; 13…nozzle; 14…nozzle surface; 15…recording control unit; 21…transport unit; 22…first transport roller; 23…second transport roller; 24…driving source; 25…transport belt; 26…inner peripheral surface; 27…outer peripheral surface; 28…pressing unit; 31…cleaning mechanism; 32…cleaning unit; 33…cleaning roller; 34…cleaning blade; 35…storage unit; 36…cleaning tank; 37…immersion tank; 38…support tank; 39…storage tank; 40…first connecting flow channel; 41…second connecting flow channel; 42…detection flow channel; 43…first flow channel portion; 44…second flow channel portion points; 45…reflecting sheet; 46…light-absorbing sheet; 47…supply channel; 48…discharge channel; 49…pump; 50…flow meter; 51…constant flow valve; 52…first opening and closing valve; 53…second opening and closing valve; 54…third opening and closing valve; 55…liquid volume sensor; 56…cleaning filter; 57…storage filter; 58…detection unit; 59…first detection unit; 60…second detection unit; 61…first light-emitting unit; 62…first light-receiving unit; 63…second light-emitting unit; 64…second light-receiving unit; 65…cleaning control unit; 99…medium; A1…conveying direction; A2…opposite direction; D1…corresponding data.

Claims

1. A recording device, characterized in that: have: A conveyor belt, which conveys the medium; a recording unit that records an image on a medium by ejecting a pigment ink onto the medium conveyed by the conveyor belt; A cleaning mechanism, which uses a cleaning fluid to clean the conveyor belt, The pigment ink includes black ink and ink other than the black ink, The cleaning mechanism comprises: A storage unit for storing the cleaning liquid; a first detection unit configured to detect an ink concentration of the black ink contained in the cleaning liquid stored in the storage unit; a second detection unit for detecting the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage unit; Cleaning control unit, The second detection unit detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid. The cleaning control unit determines a threshold value based on the ink concentration of the black ink detected by the first detection unit, and discharges the cleaning liquid from the storage unit when the ink concentration of the pigment ink detected by the second detection unit is equal to or greater than the threshold value.

2. The recording device according to claim 1, characterized in that The first detection unit has: a first light emitting portion that emits light; a first light receiving unit that receives light emitted by the first light emitting unit, The first light receiving unit receives the light transmitted through the cleaning liquid to detect the ink concentration of the black ink. The second detection unit has: a second light emitting portion that emits light; a second light receiving unit, which receives light emitted by the second light emitting unit; The ink concentration of the pigment ink is detected by receiving the light scattered in the cleaning liquid by the second light receiving unit.

3. The recording device according to claim 2, characterized in that The storage part has a detection flow channel for the cleaning liquid to flow. The detection channel has a first channel portion and a second channel portion, The first detection unit detects ink concentration in the first flow channel. The ink concentration is detected by the second detection unit in the second flow channel. A width of the first flow channel portion is smaller than a width of the second flow channel portion.

4. The recording device according to claim 2, characterized in that The storage part has a detection flow channel for the cleaning liquid to flow. The detection flow channel has: a first flow channel portion, wherein the first detection portion detects ink concentration; a second flow channel portion, wherein the ink concentration is detected by the second detection portion; The reflective sheet reflects the light emitted by the first light emitting portion toward the first light receiving portion, and the first light emitting portion and the first light receiving portion are arranged along the first flow channel portion.

5. The recording device according to claim 2, characterized in that The storage part has a detection flow channel for the cleaning liquid to flow. The detection flow channel has: a first flow channel portion, wherein the first detection portion detects ink concentration; a second flow channel portion, wherein the ink concentration is detected by the second detection portion; a light-absorbing sheet that absorbs light emitted by the second light-emitting portion, The second light emitting portion and the second light receiving portion are arranged along the second flow channel portion.

6. The recording device according to claim 1, wherein The storage unit has: cleaning tank; Storage slots; A first connecting channel connected to the cleaning tank and the receiving tank; The second connecting channel is connected to the cleaning tank and the receiving tank. The cleaning mechanism comprises: a cleaning unit, which uses the cleaning liquid stored in the cleaning tank to clean the conveyor belt; A pump circulates the cleaning liquid between the cleaning tank and the storage tank through the first connecting flow channel and the second connecting flow channel.

7. The recording device according to claim 6, characterized in that The pump delivers the cleaning liquid from the cleaning tank to the receiving tank through the first connecting flow channel, and delivers the cleaning liquid from the receiving tank to the cleaning tank through the second connecting flow channel. The first detection unit detects the ink concentration of the black ink contained in the cleaning liquid flowing in the first connecting flow channel. The second detection unit detects the ink concentration of the pigment ink contained in the cleaning liquid flowing through the first connecting flow channel.

8. The recording device according to any one of claims 1 to 7, characterized in that The purge control unit stores correspondence data in which the ink density of the black ink and the threshold value are associated with each other, and determines the threshold value based on the ink density of the black ink by referring to the correspondence data.

9. A cleaning mechanism, characterized in that: A conveyor belt conveying a medium on which an image is recorded by ejecting a pigment ink including black ink and ink other than the black ink is cleaned with a cleaning liquid. The cleaning mechanism comprises: A storage unit for storing the cleaning liquid; a first detection unit configured to detect an ink concentration of the black ink contained in the cleaning liquid stored in the storage unit; a second detection unit for detecting the ink concentration of the pigment ink contained in the cleaning liquid stored in the storage unit; Cleaning control unit, The second detection unit detects the ink concentration of the pigment ink by receiving light scattered in the cleaning liquid. The cleaning control unit determines a threshold value based on the ink concentration of the black ink detected by the first detection unit, and discharges the cleaning liquid from the storage unit when the ink concentration of the pigment ink detected by the second detection unit is equal to or greater than the threshold value.

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