Processing device

Abstract

The present invention provides a processing device. The processing device comprises: a first light source and a second light source, which emit light with a peak wavelength included in 900nm and above and below 2100nm; a first light receiving unit, which receives the light emitted by the first light source; a second light receiving unit, which receives the light emitted by the second light source; a support unit, which supports a medium to be transported; a processing unit, which is opposite to the support unit and performs a process on the medium to increase or decrease the amount of water contained in the medium, the first light source and the first light receiving unit are located upstream of the processing unit in the transport direction of the medium to be transported, the first light source irradiates light to the medium before being processed by the processing unit, and the first light receiving unit receives light reflected from the medium, the second light source and the second light receiving unit are located downstream of the processing unit in the transport direction, the second light source irradiates light to the medium after being processed by the processing unit, and the second light receiving unit receives light reflected from the medium.

Description

Technical Field

[0001] The invention relates to a processing device. Background Art

[0002] Patent Document 1 describes an image forming device for printing on a medium as an example of a processing device for processing a medium. The image forming device includes a sensor for detecting the surface roughness of the medium. The image forming device determines the glossiness of the medium based on the surface roughness of the medium detected by the sensor. The image forming device determines the type of the medium based on the glossiness of the medium. The image forming device prints on the medium with settings corresponding to the type of the medium by determining the type of the medium.

[0003] Even for the same type of media, the surface roughness of the media may be different for each medium. Not limited to the surface roughness of the media, even for the same type of media, its characteristics may be different for each medium. For example, even if the same treatment is applied to the same type of media, the change in the amount of moisture contained in the media may be different for each medium. The amount of moisture contained in the medium has a great influence on the printing quality of the medium. Therefore, it is important in the processing device to detect the change in the amount of moisture contained in the medium to be processed.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-181060 Summary of the invention

[0005] A processing device for solving the above-mentioned technical problem comprises: a first light source and a second light source, which emit light with a peak wavelength included in a range of 900 nm to 2100 nm; a first light receiving unit, which receives the light emitted by the first light source; a second light receiving unit, which receives the light emitted by the second light source; a support unit, which supports a medium to be transported; and a processing unit, which is opposite to the support unit and performs a process on the medium to increase or decrease the amount of water contained in the medium, wherein the first light source and the first light receiving unit are located upstream of the processing unit in a transport direction of the medium to be transported, the first light source irradiates light to the medium before being processed by the processing unit, and the first light receiving unit receives light reflected from the medium, and the second light source and the second light receiving unit are located downstream of the processing unit in the transport direction, the second light source irradiates light to the medium after being processed by the processing unit, and the second light receiving unit receives light reflected from the medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a schematic diagram showing a first embodiment of a printing system including a processing device.

[0007] Figure 2 for Figure 1 Magnified image of .

[0008] Figure 3 4 is a cross-sectional view of the first optical sensor with the first light shielding portion in a first state.

[0009] Figure 4 4 is a cross-sectional view of the first optical sensor with the first light shielding portion in the second state.

[0010] Figure 5 4 is a cross-sectional view of the second optical sensor with the second light shielding portion in the third state.

[0011] Figure 6 4 is a cross-sectional view of the second optical sensor with the second light shielding portion in the fourth state.

[0012] Figure 7 A cross-sectional view showing a capacitive sensor.

[0013] Figure 8 It is a schematic diagram showing a second embodiment of a printing system including a processing device. DETAILED DESCRIPTION

[0014] Hereinafter, an embodiment of a printing system including a processing device will be described with reference to the drawings.

[0015] First embodiment

[0016] like Figure 1 As shown, the printing system 11 of the first embodiment includes a holding device 12 , a winding device 13 , a printing device 14 , and a drying device 15 .

[0017] The holding device 12 is a device for holding a roll body 100 formed by overlapping and winding the medium 99. The holding device 12 has a holding shaft 17 for holding the roll body 100. The holding shaft 17 is, for example, configured to be rotatable. As the holding shaft 17 rotates, the medium 99 is unwound from the roll body 100. In the first embodiment, the holding shaft 17 does not actively rotate, but, for example, by pulling the medium 99 from the roll body 100, the holding shaft 17 and the roll body 100 rotate together. The medium 99 is, for example, a thin sheet such as paper or cloth. The holding shaft 17 may also be a non-rotating structure. In this case, by pulling the medium 99 from the roll body 100, the roll body 100 rotates relative to the holding shaft 17.

[0018] The winding device 13 is a device for winding up the medium 99 unwound from the holding device 12. The winding device 13 has a winding shaft 18 for winding up the medium 99. The winding shaft 18 is configured to be rotatable. The winding shaft 18 winds up the medium 99 by rotating. As a result, the winding shaft 18 holds the roll body 100 formed by winding up the medium 99. In the first embodiment, the winding shaft 18 rotates to unwind the medium 99 from the roll body 100 held by the holding shaft 17.

[0019] The medium 99 is transported by being taken up by the take-up device 13. The medium 99 is transported from the holding device 12 toward the take-up device 13. In the first embodiment, the direction from the holding device 12 toward the take-up device 13 is the transport direction Y of the medium 99. The medium 99 has a front surface 99A and a back surface 99B opposite to the front surface 99A.

[0020] The printing device 14 is a device that prints on the medium 99. The printing device 14 is, for example, an inkjet printer that records images such as text, photos, and graphics by ejecting ink, which is an example of liquid, onto the medium 99. In the first embodiment, the printing device 14 is an example of a processing device. That is, the printing device 14 processes the medium 99 by printing on the medium 99.

[0021] The printing device 14 is located between the holding device 12 and the winding device 13 in the conveying direction Y. In other words, the printing device 14 is located between the holding device 12 and the drying device 15 in the conveying direction Y. Therefore, the medium 99 unwound from the holding device 12 passes through the printing device 14 and the drying device 15 in sequence.

[0022] The printing device 14 includes a first support unit 21, a printing unit 22, and a first control unit 23. The printing device 14 includes a first ultrasonic sensor 24 and a second ultrasonic sensor 25. The printing device 14 includes a first optical sensor 26 and a second optical sensor 27. The printing device 14 includes a capacitive sensor 28.

[0023] The first support portion 21 is, for example, a plate-shaped member. The first support portion 21 supports the medium 99 being transported. The first support portion 21 of the first embodiment supports the medium 99 from below. The first support portion 21 of the first embodiment is in contact with the back surface 99B of the medium 99. The first support portion 21 is a support portion provided in the printing device 14 in the printing system 11. The first support portion 21 of the first embodiment has a mounting hole 31 for mounting the capacitance sensor 28.

[0024] The printing unit 22 faces the first support unit 21. The printing unit 22 of the first embodiment is located above the first support unit 21. The printing unit 22 is configured to print on the medium 99. The printing unit 22 of the first embodiment includes a head 32 and a carriage 33.

[0025] The head 32 is opposite to the first support portion 21. The head 32 of the first embodiment is located above the first support portion 21. The head 32 ejects liquid toward the medium 99 supported by the first support portion 21. As a result, an image is printed on the medium 99. The head 32 of the first embodiment ejects liquid toward the front surface 99A of the medium 99. The liquid ejected by the head 32 is, for example, an aqueous ink using water as a solvent.

[0026] When the head 32 ejects the liquid onto the medium 99, the amount of water contained in the medium 99 increases. That is, the head 32 performs a process on the medium 99 to increase the amount of water contained in the medium 99 by ejecting the liquid onto the medium 99. The head 32 performs the process on the front surface 99A of the medium 99 opposite to the back surface 99B contacted by the first support part 21. In this regard, the head 32 of the first embodiment is an example of a processing unit.

[0027] The carriage 33 carries the head 32. The carriage 33 is opposite to the first support portion 21. The carriage 33 of the first embodiment is located above the first support portion 21. The carriage 33 scans the transported medium 99. That is, the carriage 33 reciprocates above the first support portion 21 in a manner spanning the width of the medium 99. At this time, the carriage 33 reciprocates in the scanning direction X.

[0028] The scanning direction X represents two directions including a first direction D1 and a second direction D2. The first direction D1 is a direction opposite to the second direction D2. The first direction D1 and the second direction D2 are directions different from the conveying direction Y and the vertical direction Z.

[0029] The printing device 14 of the first embodiment is a serial printer in which the head 32 scans the medium 99. The printing device 14 may be a line printer in which the head 32 ejects liquid all at once across the width of the medium 99.

[0030] The first control unit 23 controls various components of the printing device 14. For example, the first control unit 23 controls the printing unit 22. The first control unit 23 is a control unit provided in the printing device 14 in the printing system 11.

[0031] The first control unit 23 of the first embodiment is configured to be able to communicate with the holding device 12, the winding device 13, and the drying device 15. The first control unit 23 receives signals from the holding device 12, the winding device 13, and the drying device 15 as needed, or sends signals to the holding device 12, the winding device 13, and the drying device 15. The first control unit 23 may also control the printing system 11 in an integrated manner.

[0032] The first control unit 23 can be configured as a circuit including α: one or more processors that execute various processes according to a computer program, β: one or more dedicated hardware circuits such as integrated circuits for specific purposes that execute at least a part of the various processes, or γ: a combination thereof. The processor includes a CPU and a memory such as a RAM and a ROM, and the memory stores program codes or instructions configured in such a way that the CPU executes the process. The memory, i.e., the computer-readable medium, includes all readable media that can be accessed by a general-purpose or dedicated computer.

[0033] like Figure 2 As shown, the first ultrasonic sensor 24 is, for example, located upstream of the first support portion 21 in the conveying direction Y. The first ultrasonic sensor 24 includes a first emitting portion 34 and a first receiving portion 35. The first emitting portion 34 and the first receiving portion 35 are arranged so as to sandwich the conveyed medium 99. In the first embodiment, the first emitting portion 34 and the first receiving portion 35 are arranged so as to sandwich the conveyed medium 99 from top to bottom. That is, the medium 99 is conveyed so as to pass between the first emitting portion 34 and the first receiving portion 35.

[0034] The first emitting section 34 is, for example, located above the first receiving section 35. The first emitting section 34 is configured to emit ultrasonic waves. The first emitting section 34 emits ultrasonic waves toward the first receiving section 35. That is, the first emitting section 34 emits ultrasonic waves toward the bottom. Therefore, when the medium 99 is located between the first emitting section 34 and the first receiving section 35, the ultrasonic waves emitted from the first emitting section 34 are irradiated to the medium 99. At this time, the ultrasonic waves emitted from the first emitting section 34 are irradiated to the medium 99 before printing. When the medium 99 is not located between the first emitting section 34 and the first receiving section 35, the ultrasonic waves emitted from the first emitting section 34 are directly irradiated to the first receiving section 35.

[0035] The first receiving unit 35 is, for example, located below the first emitting unit 34. The first receiving unit 35 is configured to receive ultrasonic waves. The first receiving unit 35 receives ultrasonic waves emitted by the first emitting unit 34. That is, the first receiving unit 35 receives ultrasonic waves irradiated from above. Therefore, when the medium 99 is located between the first emitting unit 34 and the first receiving unit 35, the first receiving unit 35 receives ultrasonic waves emitted from the first emitting unit 34 and transmitted through the medium 99. At this time, the first receiving unit 35 receives ultrasonic waves transmitted through the medium 99 before printing. When the medium 99 is not located between the first emitting unit 34 and the first receiving unit 35, the first receiving unit 35 directly receives ultrasonic waves emitted from the first emitting unit 34.

[0036] The ultrasonic wave emitted from the first emission unit 34 is attenuated by passing through the medium 99. Therefore, when the medium 99 is located between the first emission unit 34 and the first receiving unit 35, the intensity of the ultrasonic wave received by the first receiving unit 35 becomes lower than when the medium 99 is not located between the first emission unit 34 and the first receiving unit 35. The degree of attenuation of the ultrasonic wave passing through the medium 99 varies depending on the density, thickness, etc. of the medium 99.

[0037] The transmittance of the ultrasonic wave with respect to the medium 99 is detected based on the intensity of the ultrasonic wave received by the first receiving unit 35 when the medium 99 is located between the first emitting unit 34 and the first receiving unit 35, and the intensity of the ultrasonic wave received by the first receiving unit 35 when the medium 99 is not located between the first emitting unit 34 and the first receiving unit 35. The transmittance of the ultrasonic wave with respect to the medium 99 refers to the ratio of the ultrasonic wave that has passed through the medium 99 to the ultrasonic wave emitted by the first emitting unit 34.

[0038] There is a correlation between the transmittance of the ultrasonic wave to the medium 99 and the grammage of the medium 99. For example, the greater the transmittance of the ultrasonic wave to the medium 99, the smaller the grammage of the medium 99. The smaller the transmittance of the ultrasonic wave to the medium 99, the greater the grammage of the medium 99. In this way, the grammage of the medium 99 is detected based on the transmittance of the ultrasonic wave to the medium 99. Therefore, the first ultrasonic sensor 24 is a sensor for detecting the grammage of the medium 99. The grammage of the medium 99 can also be calculated by the first control unit 23 based on the signal sent from the first ultrasonic sensor 24.

[0039] The second ultrasonic sensor 25 is located, for example, upstream of the printing unit 22 in the conveying direction Y. The second ultrasonic sensor 25 of the first embodiment is located between the first ultrasonic sensor 24 and the printing unit 22 in the conveying direction Y.

[0040] The second ultrasonic sensor 25 includes a second emitting unit 36 ​​and a second receiving unit 37. The second emitting unit 36 ​​and the second receiving unit 37 are opposite to the first supporting unit 21. The second emitting unit 36 ​​and the second receiving unit 37 are located above the first supporting unit 21. In the first embodiment, the second emitting unit 36 ​​and the second receiving unit 37 are arranged in sequence in the conveying direction Y.

[0041] The second emitting section 36 is configured to emit ultrasonic waves. The second emitting section 36 emits ultrasonic waves toward the downward direction. The second emitting section 36 irradiates the medium 99 or the first supporting section 21 with ultrasonic waves. That is, when the medium 99 is located below the second emitting section 36, the second emitting section 36 irradiates the medium 99 with ultrasonic waves. At this time, the second emitting section 36 irradiates the front surface 99A of the medium 99. When the medium 99 is not located below the second emitting section 36, the second emitting section 36 irradiates the first supporting section 21 with ultrasonic waves.

[0042] The ultrasonic wave emitted from the second emission part 36 is reflected by the medium 99 or the first support part 21. In the first embodiment, when the medium 99 is located below the second emission part 36, the ultrasonic wave emitted from the second emission part 36 is reflected by the medium 99 or the first support part 21. Figure 2 The ultrasonic wave emitted from the second emitting portion 36 is reflected at the front surface 99A of the medium 99 as shown by the solid line in FIG. 1 . In this case, when the medium 99 is not located below the second emitting portion 36, the ultrasonic wave emitted from the second emitting portion 36 is reflected at the front surface 99A of the medium 99. Figure 2 As shown by the double-dashed line in FIG. , the light is reflected at the first supporting portion 21 .

[0043] The second receiving unit 37 is configured to receive ultrasonic waves. The second receiving unit 37 receives ultrasonic waves emitted by the second emitting unit 36. The second receiving unit 37 receives ultrasonic waves emitted from the second emitting unit 36 ​​and reflected from the medium 99 or the first supporting unit 21. That is, when the medium 99 is located below the second emitting unit 36, the second receiving unit 37 receives ultrasonic waves emitted from the second emitting unit 36 ​​and reflected from the medium 99. At this time, the second receiving unit 37 receives ultrasonic waves reflected from the front surface 99A of the medium 99. When the medium 99 is not located below the second emitting unit 36, the second receiving unit 37 receives ultrasonic waves emitted from the second emitting unit 36 ​​and reflected from the first supporting unit 21.

[0044] The second receiving unit 37 receives the ultrasonic wave emitted from the second emitting unit 36 ​​and reflected by the object, thereby detecting the distance between the second ultrasonic sensor 25 and the object. That is, the distance between the second ultrasonic sensor 25 and the object is detected by detecting the time from the second emitting unit 36 ​​emitting the ultrasonic wave to the second receiving unit 37 receiving the ultrasonic wave, that is, by the so-called flight time. In the first embodiment, the second ultrasonic sensor 25 detects the vertical distance between the second ultrasonic sensor 25 and the object.

[0045] The second receiving unit 37 receives the ultrasonic wave emitted from the second emitting unit 36 ​​and reflected at the front surface 99A of the medium 99, thereby detecting the distance between the second ultrasonic sensor 25 and the front surface 99A of the medium 99. The second receiving unit 37 receives the ultrasonic wave emitted from the second emitting unit 36 ​​and reflected at the first supporting unit 21, thereby detecting the distance between the second ultrasonic sensor 25 and the first supporting unit 21. Here, the distance between the second ultrasonic sensor 25 and the first supporting unit 21 can be regarded as the distance between the second ultrasonic sensor 25 and the back surface 99B of the medium 99.

[0046] The distance between the front surface 99A and the back surface 99B, that is, the thickness of the medium 99 can be grasped based on the distance between the second ultrasonic sensor 25 and the front surface 99A and the distance between the second ultrasonic sensor 25 and the back surface 99B. That is, the thickness of the medium 99 is detected based on the ultrasonic wave reflected at the front surface of the medium 99 and the ultrasonic wave reflected at the first support portion 21. In this way, the second ultrasonic sensor 25 is a sensor for detecting the thickness of the medium 99. The first control unit 23 may also calculate the thickness of the medium 99 based on the signal sent from the second ultrasonic sensor 25.

[0047] like Figure 1 As shown, the first optical sensor 26 is located upstream of the head 32 in the conveying direction Y. The first optical sensor 26 is opposite to the first support portion 21. The first optical sensor 26 is located above the first support portion 21. The first optical sensor 26 is mounted on, for example, the carriage 33. The first optical sensor 26 of the first embodiment is mounted on the surface of the carriage 33 that faces upstream in the conveying direction Y. The first optical sensor 26 is mounted on the carriage 33, and scans the medium 99 together with the carriage 33.

[0048] like Figure 3 as well as Figure 4 As shown, the first optical sensor 26 includes a first housing 41, a first light source 42, and a first light receiving unit 43. The first optical sensor 26 of the first embodiment further includes a first light shielding unit 44. The first optical sensor 26 is a reflective optical sensor.

[0049] The first housing 41 accommodates the first light source 42, the first light receiving portion 43, and the first light shielding portion 44. The shape of the first housing 41 is, for example, a rectangular parallelepiped or a rectangular parallelepiped. The first housing 41 has a first opening 45. The first opening 45 is provided on a surface of the first housing 41 that is opposite to the first support portion 21. That is, in the first embodiment, the first opening 45 is provided on the lower surface of the first housing 41. The interior of the first housing 41 and the exterior of the first housing 41 are communicated through the first opening 45.

[0050] The first light source 42 is a light source that emits light. The first light source 42 emits light having a peak wavelength at the absorption wavelength of water. The first light source 42 is configured to emit light having a peak wavelength within a range of 900 nm to 2100 nm, for example. The first light source 42 of the first embodiment emits near-infrared light.

[0051] The first light source 42 of the first embodiment irradiates light downward. Therefore, the first light source 42 of the first embodiment irradiates light toward the medium 99 before being processed by the head 32, for example. At this time, the first light source 42 irradiates light toward the front surface 99A of the medium 99.

[0052] The first light source 42 has one or more light-emitting elements that emit light. In the first embodiment, the first light source 42 has multiple light-emitting elements. Specifically, the first light source 42 has multiple light-emitting elements with different peak wavelengths. The light-emitting element is, for example, an LED. The first light source 42 has, for example, a first light-emitting element 46 and a second light-emitting element 47. The first light source 42 may also have more than three light-emitting elements.

[0053] The first light-emitting element 46 is, for example, a light-emitting element that emits light with a peak wavelength of 940 nm. 940 nm is the absorption wavelength of water. The second light-emitting element 47 is, for example, a light-emitting element that emits light with a peak wavelength of 1450 nm. 1450 nm is the absorption wavelength of water. The first light-emitting element 46 and the second light-emitting element 47 only need to be light-emitting elements that emit light with a peak wavelength that is the absorption wavelength of water. For example, the first light-emitting element 46 can be a light-emitting element that emits light with a peak wavelength of 1800 nm, a light-emitting element that emits light with a peak wavelength of 1940 nm, or a light-emitting element that emits light with a peak wavelength of 2100 nm. Similarly, the second light-emitting element 47 can be a light-emitting element that emits light with a peak wavelength of 1800 nm, a light-emitting element that emits light with a peak wavelength of 1940 nm, or a light-emitting element that emits light with a peak wavelength of 2100 nm. 1800 nm, 1940 nm, and 2100 nm are all absorption wavelengths of water.

[0054] The peak wavelength of light emitted by the first light emitting element 46 is lower than the peak wavelength of light emitted by the second light emitting element 47. In this regard, the first light emitting element 46 is an example of a short-wavelength light emitting element. The second light emitting element 47 is an example of a long-wavelength light emitting element.

[0055] The first light receiving unit 43 receives light emitted by the first light source 42. The first light receiving unit 43 includes, for example, a light receiving element. The light receiving element is, for example, a photodiode. The first light receiving unit 43 receives light from the first light source 42 traveling in the first detection light path L1, or light from the first light source 42 traveling in the first reference light path L2. That is, the light emitted by the first light source 42 enters the first light receiving unit 43 by traveling in the first detection light path L1 or the first reference light path L2.

[0056] The first detection optical path L1 is an optical path in which the light emitted by the first light source 42 is reflected by the medium 99 supported by the first support portion 21 and enters the first light receiving portion 43. Figure 3 Indicated by the solid line and in Figure 4 The first detection light path L1 extends inside the first housing 41 and outside the first housing 41 via the first opening 45. The first detection light path L1 extends from the first light source 42 to the medium 99 supported by the first support portion 21, and then extends from the medium 99 to the first light receiving portion 43.

[0057] The light traveling in the first detection optical path L1 first collides with the medium 99 by passing through the first opening 45 from the first light source 42. At this time, the light traveling in the first detection optical path L1 collides with the front surface 99A of the medium 99. The light that collides with the front surface 99A of the medium 99 is reflected at the front surface 99A of the medium 99. The light reflected at the front surface 99A of the medium 99 passes through the first opening 45 and enters the first light receiving unit 43. In this way, the light emitted by the first light source 42 travels in the first detection optical path L1. As a result, the first light receiving unit 43 receives the light reflected at the medium 99.

[0058] The first reference optical path L2 is an optical path along which the light emitted by the first light source 42 enters the first light receiving unit 43 without being reflected by the medium 99 supported by the first support unit 21. Figure 3 Indicated by the double-dashed line and in Figure 4 The first reference optical path L2 is an optical path shown by a solid line in FIG. The first reference optical path L2 extends inside the first housing 41. The first reference optical path L2 extends straight from the first light source 42 to the first light receiving portion 43 inside the first housing 41. Therefore, the light traveling in the first reference optical path L2 is directly incident from the first light source 42 to the first light receiving portion 43. Thereby, the first light receiving portion 43 directly receives the light emitted by the first light source 42.

[0059] The first light shielding portion 44 is configured to shield the light emitted by the first light source 42. The shape of the first light shielding portion 44 is, for example, a flat plate or a flat plate. The first light shielding portion 44 is located between the first light source 42 and the first light receiving portion 43 inside the first housing 41. The first light shielding portion 44 is, for example, provided in a manner spanning the first detection light path L1 and the first reference light path L2. The first light shielding portion 44 blocks the first detection light path L1 or the first reference light path L2. The first light shielding portion 44 shields the light emitted by the first light source 42 by blocking the first detection light path L1 or the first reference light path L2.

[0060] The first light shielding portion 44 is configured to switch between a first state S1 and a second state S2 . Figure 3 The first light shielding portion 44 is shown in the first state S1 . Figure 4 The first light shielding portion 44 is shown in the second state S2.

[0061] The first light shielding portion 44 switches between the first state S1 and the second state S2 by, for example, shifting. The first light shielding portion 44 of the first embodiment is configured to rotate around the first rotation axis 48 as an imaginary axis. The first light shielding portion 44 of the first embodiment switches between the first state S1 and the second state S2 by rotating around the first rotation axis 48. The first light shielding portion 44 is supported by the first housing 41 in a state in which it can rotate around the first rotation axis 48, for example.

[0062] The first light shielding portion 44 has, for example, a first hole 49. When the first light shielding portion 44 is in the first state S1, the first hole 49 is located on the first detection optical path L1. Therefore, when the first light shielding portion 44 is in the first state S1, the light traveling from the first light source 42 in the first detection optical path L1 is incident on the first light receiving portion 43 by passing through the first hole 49. That is, when the first light shielding portion 44 is in the first state S1, the light emitted by the first light source 42 is allowed to travel in the first detection optical path L1. In addition, when the first light shielding portion 44 is in the first state S1, the first hole 49 is not located on the first reference optical path L2. That is, when the first light shielding portion 44 is in the first state S1, the light emitted by the first light source 42 is not allowed to travel in the first reference optical path L2. In this way, the first state S1 of the first light shielding portion 44 is a state in which the first light shielding portion 44 does not block the first detection optical path L1 and the first light shielding portion 44 blocks the first reference optical path L2.

[0063] When the first light shielding portion 44 is in the second state S2, the first hole 49 is located on the first reference optical path L2. Therefore, when the first light shielding portion 44 is in the second state S2, the light traveling from the first light source 42 in the first reference optical path L2 is incident on the first light receiving portion 43 by passing through the first hole 49. That is, when the first light shielding portion 44 is in the second state S2, the light emitted by the first light source 42 is allowed to travel in the first reference optical path L2. In addition, when the first light shielding portion 44 is in the second state S2, the first hole 49 is not located on the first detection optical path L1. That is, when the first light shielding portion 44 is in the second state S2, the light emitted by the first light source 42 is not allowed to travel in the first detection optical path L1. In this way, the second state S2 of the first light shielding portion 44 is a state in which the first light shielding portion 44 blocks the first detection optical path L1 and the first light shielding portion 44 does not block the first reference optical path L2.

[0064] The first light shielding portion 44 determines the optical path along which the light emitted by the first light source 42 travels by switching between the first state S1 and the second state S2. In the first embodiment, the first control unit 23 switches the first light shielding portion 44 between the first state S1 and the second state S2.

[0065] When light is irradiated from the first light source 42 to the medium 99, that is, when the light traveling in the first detection optical path L1 hits the medium 99, a portion of the light is absorbed by the medium 99. In particular, the near-infrared light emitted by the first light source 42 is easily absorbed by water. Therefore, the more water content the medium 99 contains, the more light is absorbed by the medium 99. Conversely, when the water content of the medium 99 is less, the less light is absorbed by the medium 99.

[0066] The first light receiving unit 43 receives the light traveling in the first detection optical path L1, thereby detecting the intensity of the light reflected at the medium 99. The first light receiving unit 43 receives the light traveling in the first reference optical path L2, thereby detecting the intensity of the light irradiated to the medium 99 by the first light source 42. Based on the intensity of the light traveling in the first detection optical path L1 and the intensity of the light traveling in the first reference optical path L2, the reflectivity of the light with respect to the medium 99 is detected. Here, the reflectivity of the light with respect to the medium 99 refers to the ratio of the light reflected at the medium 99 to the light irradiated to the medium 99.

[0067] There is a correlation between the reflectivity of light relative to the medium 99 and the amount of moisture contained in the medium 99. For example, the greater the reflectivity of light relative to the medium 99, the less moisture contained in the medium 99. The smaller the reflectivity of light relative to the medium 99, the more moisture contained in the medium 99. In this way, the amount of moisture contained in the medium 99 is detected based on the reflectivity of light relative to the medium 99. Therefore, the first optical sensor 26 is a sensor that detects the amount of moisture contained in the medium 99 before printing, that is, before processing. The first optical sensor 26 is particularly capable of detecting the moisture content of the front side 99A with high precision. The first control unit 23 can also calculate the amount of moisture contained in the medium 99 based on the signal sent from the first optical sensor 26.

[0068] like Figure 1 As shown, the second optical sensor 27 is located downstream of the head 32 in the conveying direction Y. The second optical sensor 27 is opposite to the first support portion 21. The second optical sensor 27 is located above the first support portion 21. The second optical sensor 27 is mounted on the carriage 33, for example. The second optical sensor 27 of the first embodiment is mounted on the surface facing downstream in the conveying direction Y with respect to the carriage 33. The second optical sensor 27 is mounted on the carriage 33, and scans the medium 99 together with the carriage 33. In the first embodiment, the structure of the second optical sensor 27 is the same as that of the first optical sensor 26.

[0069] like Figure 5 as well as Figure 6 As shown, the second optical sensor 27 includes a second housing 51, a second light source 52, and a second light receiving unit 53. The second optical sensor 27 of the first embodiment further includes a second light shielding unit 54. The second optical sensor 27 is a reflective optical sensor.

[0070] The second housing 51 accommodates the second light source 52, the second light receiving portion 53, and the second light shielding portion 54. The shape of the second housing 51 is, for example, a rectangular parallelepiped or a rectangular parallelepiped. The second housing 51 has a second opening 55. The second opening 55 is provided on the surface of the second housing 51 that is opposite to the first support portion 21. That is, in the first embodiment, the second opening 55 is provided on the lower surface of the second housing 51. The interior of the second housing 51 and the exterior of the second housing 51 are communicated through the second opening 55.

[0071] The second light source 52 is a light source that emits light. The second light source 52 emits light having a peak wavelength at the absorption wavelength of water. The second light source 52 is configured to emit light having a peak wavelength within a range of 900 nm to 2100 nm, for example. The second light source 52 of the first embodiment emits near-infrared light.

[0072] The second light source 52 of the first embodiment irradiates light downward. Therefore, for example, the second light source 52 of the first embodiment irradiates light toward the medium 99 processed by the head 32. At this time, the second light source 52 irradiates light toward the front surface 99A of the medium 99.

[0073] The second light source 52 has one or more light emitting elements that emit light. In the first embodiment, the second light source 52 has a plurality of light emitting elements. Specifically, the second light source 52 has a plurality of light emitting elements with different peak wavelengths. The second light source 52 has, for example, a third light emitting element 56 and a fourth light emitting element 57. The second light source 52 may also have three or more light emitting elements.

[0074] The third light emitting element 56 is, for example, a light emitting element that emits light with a peak wavelength of 940 nm. The fourth light emitting element 57 is, for example, a light emitting element that emits light with a peak wavelength of 1450 nm. The third light emitting element 56 and the fourth light emitting element 57 only need to be light emitting elements that emit light with a peak wavelength that is the absorption wavelength of water. For example, the third light emitting element 56 can be a light emitting element that emits light with a peak wavelength of 1800 nm, a light emitting element that emits light with a peak wavelength of 1940 nm, or a light emitting element that emits light with a peak wavelength of 2100 nm. Similarly, the fourth light emitting element 57 can be a light emitting element that emits light with a peak wavelength of 1800 nm, a light emitting element that emits light with a peak wavelength of 1940 nm, or a light emitting element that emits light with a peak wavelength of 2100 nm.

[0075] The peak wavelength of light emitted by the third light emitting element 56 is lower than the peak wavelength of light emitted by the fourth light emitting element 57. In this regard, the third light emitting element 56 is an example of a short-wavelength light emitting element. The fourth light emitting element 57 is an example of a long-wavelength light emitting element.

[0076] The second light receiving unit 53 receives light emitted by the second light source 52. The second light receiving unit 53 includes, for example, a light receiving element. The second light receiving unit 53 receives light traveling from the second light source 52 in the second detection light path L3, or light traveling from the second light source 52 in the second reference light path L4. That is, the light emitted by the second light source 52 enters the second light receiving unit 53 by traveling in the second detection light path L3 or the second reference light path L4.

[0077] The second detection optical path L3 is an optical path in which the light emitted by the second light source 52 is reflected by the medium 99 supported by the first support part 21 and enters the second light receiving part 53. Figure 5 Indicated by the solid line and Figure 6The second detection optical path L3 extends inside the second housing 51 and outside the second housing 51 via the second opening 55. The second detection optical path L3 extends from the second light source 52 to the medium 99 supported by the first support portion 21, and then extends from the medium 99 to the second light receiving portion 53.

[0078] The light traveling in the second detection optical path L3 first collides with the medium 99 by passing through the second opening 55 from the second light source 52. At this time, the light traveling in the second detection optical path L3 collides with the front surface 99A of the medium 99. The light that collides with the front surface 99A of the medium 99 is reflected at the front surface 99A of the medium 99. The light reflected at the front surface 99A of the medium 99 passes through the second opening 55 and enters the second light receiving unit 53. In this way, the light emitted by the second light source 52 travels in the second detection optical path L3. As a result, the second light receiving unit 53 receives the light reflected at the medium 99.

[0079] The second reference optical path L4 is an optical path along which the light emitted by the second light source 52 enters the second light receiving portion 53 without being reflected by the medium 99 supported by the first support portion 21. Figure 5 Indicated by the double-dashed line and in Figure 6 The second reference optical path L4 extends inside the second housing 51. The second reference optical path L4 extends straight from the second light source 52 to the second light receiving portion 53 inside the second housing 51. Therefore, the light traveling in the second reference optical path L4 is directly incident from the second light source 52 to the second light receiving portion 53. Thereby, the second light receiving portion 53 directly receives the light emitted by the second light source 52.

[0080] The second light shielding portion 54 is configured to shield the light emitted by the second light source 52. The shape of the second light shielding portion 54 is, for example, a flat plate or a flat plate. The second light shielding portion 54 is located between the second light source 52 and the second light receiving portion 53 inside the second housing 51. The second light shielding portion 54 is, for example, provided in a manner spanning the second detection light path L3 and the second reference light path L4. The second light shielding portion 54 blocks the second detection light path L3 or the second reference light path L4. The second light shielding portion 54 blocks the light emitted by the second light source 52 by blocking the second detection light path L3 or the second reference light path L4.

[0081] The second light shielding portion 54 is configured to switch between a third state S3 and a fourth state S4 . Figure 5 The second light shielding portion 54 is shown in the third state S3. Figure 6 The second light shielding portion 54 is shown in the fourth state S4.

[0082] The second light shielding portion 54 switches between the third state S3 and the fourth state S4 by, for example, shifting. The second light shielding portion 54 of the first embodiment is configured to rotate around the second rotation axis 58 as an imaginary axis. The second light shielding portion 54 of the first embodiment switches between the third state S3 and the fourth state S4 by rotating around the second rotation axis 58. The second light shielding portion 54 is supported by the second housing 51 in a state where it can rotate around the second rotation axis 58, for example.

[0083] The second light shielding portion 54 has, for example, a second hole 59. When the second light shielding portion 54 is in the third state S3, the second hole 59 is located on the second detection optical path L3. Therefore, when the second light shielding portion 54 is in the third state S3, the light from the second light source 52 traveling in the second detection optical path L3 is incident on the second light receiving portion 53 by passing through the second hole 59. That is, when the second light shielding portion 54 is in the third state S3, the light emitted by the second light source 52 is allowed to travel in the second detection optical path L3. In addition, when the second light shielding portion 54 is in the third state S3, the second hole 59 is not located on the second reference optical path L4. That is, when the second light shielding portion 54 is in the third state S3, the light emitted by the second light source 52 is not allowed to travel in the second reference optical path L4. In this way, the third state S3 of the second light shielding portion 54 is a state in which the second light shielding portion 54 does not block the second detection optical path L3 and the second light shielding portion 54 blocks the second reference optical path L4.

[0084] When the second light shielding portion 54 is in the fourth state S4, the second hole 59 is located on the second reference optical path L4. Therefore, when the second light shielding portion 54 is in the fourth state S4, the light from the second light source 52 traveling in the second reference optical path L4 is incident on the second light receiving portion 53 by passing through the second hole 59. That is, when the second light shielding portion 54 is in the fourth state S4, the light emitted by the second light source 52 is allowed to travel in the second reference optical path L4. In addition, when the second light shielding portion 54 is in the fourth state S4, the second hole 59 is not located on the second detection optical path L3. That is, when the second light shielding portion 54 is in the fourth state S4, the light emitted by the second light source 52 is not allowed to travel in the second detection optical path L3. In this way, the fourth state S4 of the second light shielding portion 54 is a state in which the second light shielding portion 54 blocks the second detection optical path L3 and the second light shielding portion 54 does not block the second reference optical path L4.

[0085] The second light shielding portion 54 switches between the third state S3 and the fourth state S4 to determine the optical path along which the light emitted by the second light source 52 travels. In the first embodiment, the first control unit 23 switches the second light shielding portion 54 between the third state S3 and the fourth state S4.

[0086] The second light receiving unit 53 receives the light traveling in the second detection optical path L3, thereby detecting the intensity of the light reflected at the medium 99. The second light receiving unit 53 receives the light traveling in the second reference optical path L4, thereby detecting the intensity of the light irradiated to the medium 99 by the second light source 52. The reflectivity of the light relative to the medium 99 is detected based on the intensity of the light traveling in the second detection optical path L3 and the intensity of the light traveling in the second reference optical path L4. That is, the moisture content contained in the medium 99 is detected based on the reflectivity of the light relative to the medium 99, similar to the first optical sensor 26. Therefore, the second optical sensor 27 is a sensor that detects the moisture content contained in the medium 99 after printing, that is, after processing. The second optical sensor 27 is particularly capable of detecting the moisture content of the front side 99A with high accuracy. The moisture content contained in the medium 99 can also be calculated by the first control unit 23 based on the signal sent from the second optical sensor 27.

[0087] Based on the detection results of the first optical sensor 26 and the detection results of the second optical sensor 27, the change in the amount of moisture contained in the medium 99 with respect to the treatment performed by the processing unit on the medium 99 is detected. That is, in the first embodiment, the increase in the amount of moisture contained in the medium 99 with respect to the liquid ejected from the head 32 to the medium 99 is detected. Based on the detection results of the first optical sensor 26 and the detection results of the second optical sensor 27, the first control unit 23 calculates the increase in the amount of moisture contained in the medium 99 with respect to the treatment. The change in the amount of moisture contained in the medium 99 with respect to the treatment performed by the processing unit on the medium 99 is useful for grasping the characteristics of the medium 99.

[0088] like Figure 1 As shown, the capacitive sensor 28 is, for example, mounted on the first support portion 21. The capacitive sensor 28 of the first embodiment is mounted on the mounting hole 31. The capacitive sensor 28 is, for example, located between the first optical sensor 26 and the second optical sensor 27 in the conveying direction Y. The capacitive sensor 28 of the first embodiment is located downstream of the head 32 in the conveying direction Y.

[0089] like Figure 7 As shown in FIG. 1 , the capacitance sensor 28 is provided in a manner to be accommodated in the mounting hole 31. The capacitance sensor 28 is located below the medium 99 supported by the first support portion 21. The capacitance sensor 28 contacts the medium 99 from below. The capacitance sensor 28 contacts the medium 99 to detect the capacitance of the medium 99. The capacitance sensor 28 of the first embodiment detects the capacitance of the medium 99 after printing, that is, after processing.

[0090] The capacitance sensor 28 includes a holding portion 61 , an electrode pair 62 , and a position adjusting portion 63 . The holding portion 61 holds the electrode pair 62 . The holding portion 61 is in the shape of, for example, a rectangular parallelepiped or a rectangular parallelepiped. The holding portion 61 is attached to the position adjusting portion 63 .

[0091] The electrode pair 62 is provided so as to protrude from the holding portion 61. The electrode pair 62 of the first embodiment protrudes from the upper surface of the holding portion 61. The electrode pair 62 contacts the medium 99 supported by the first supporting portion 21. In the first embodiment, the electrode pair 62 contacts the back surface 99B of the medium 99. In this case, compared with the case where the electrode pair 62 contacts the front surface 99A of the medium 99, the possibility of damaging the front surface 99A to be printed, that is, the front surface 99A to be processed is reduced.

[0092] The electrode pair 62 constitutes a part of the oscillation circuit of the capacitance sensor 28. The electrode pair 62 is composed of two electrodes 64. An alternating voltage is applied between the two electrodes 64. That is, the capacitance sensor 28 detects the capacitance between the two electrodes 64. When the two electrodes 64 are in contact with the medium 99, an alternating current flows to the medium 99. Thus, the capacitance sensor 28 detects the capacitance of the medium 99 in contact with the electrode pair 62.

[0093] Since the alternating current flows from the two electrodes 64 to the medium 99, the capacitance between the two electrodes 64 changes. At this time, the change in capacitance between the two electrodes 64 is greatly affected by the amount of water contained in the medium 99 in contact with the two electrodes 64. The reason is that the relative dielectric constant of water is larger than that of the medium 99 using paper, cloth, etc. Therefore, for example, when the amount of water contained in the medium 99 is large, the change in capacitance between the two electrodes 64 is large. When the amount of water contained in the medium 99 is small, the change in capacitance between the two electrodes 64 becomes smaller. In this way, there is a correlation between the change in capacitance between the two electrodes 64 and the amount of water contained in the medium 99. Therefore, based on the change in capacitance between the two electrodes 64, the amount of water contained in the medium 99 is detected. The amount of water contained in the medium 99 can also be calculated by the first control unit 23 based on the signal sent from the capacitance sensor 28.

[0094] The change in capacitance between the two electrodes 64 is also affected by the gram weight of the medium 99 in contact with the two electrodes 64. For example, when the gram weight of the medium 99 is large, the change in capacitance between the two electrodes 64 is large. When the gram weight of the medium 99 is small, the change in capacitance between the two electrodes 64 is small. Therefore, in the first embodiment, the amount of water contained in the medium 99 is detected with high accuracy by the first ultrasonic sensor 24 and the capacitance sensor 28. In particular, the amount of water contained in the medium 99 is detected with high accuracy based on the specific gravity of the medium 99, the thickness of the medium 99, and the change in capacitance between the two electrodes 64.

[0095] The first optical sensor 26 and the second optical sensor 27 mainly detect the amount of moisture contained in the front surface 99A of the medium 99, while the capacitance sensor 28 mainly detects the amount of moisture contained in the back surface 99B of the medium 99 and the inside of the medium 99. Therefore, the amount of moisture contained in the medium 99 is detected with high accuracy by the first optical sensor 26, the second optical sensor 27, and the capacitance sensor 28.

[0096] When the head 32 ejects liquid to the medium 99, there is a case where most of the liquid remains on the front surface 99A of the medium 99. In this case, when referring to the detection results of the first optical sensor 26 and the detection results of the second optical sensor 27, it can be understood that the increase in the amount of water contained in the medium 99 is large relative to the amount of liquid ejected by the head 32. On the other hand, when referring to the detection results of the first optical sensor 26 and the detection results of the capacitance sensor 28, the liquid is hardly absorbed in the medium 99, and therefore, it can be understood that the increase in the amount of water contained in the medium 99 is small relative to the amount of liquid ejected by the head 32. Based on this, it can be understood that the medium 99 has a characteristic of being difficult to absorb liquid. In this way, the characteristics of the medium 99 can be understood based on the detection results of the first optical sensor 26, the detection results of the second optical sensor 27, and the detection results of the capacitance sensor 28.

[0097] The position adjustment unit 63 includes a first adjustment member 65 and a second adjustment member 66. In the first embodiment, the first adjustment member 65 and the second adjustment member 66 are located downstream of the holding unit 61 in the conveying direction Y, but may be located upstream of the holding unit 61 in the conveying direction Y.

[0098] The first adjustment member 65 is, for example, a plate or a plate-shaped member. The first adjustment member 65 is attached to the first support portion 21 and the second adjustment member 66. The first adjustment member 65 is attached to the inner peripheral surface of the attachment hole 31 with respect to the first support portion 21.

[0099] The first adjusting member 65 has a first long hole 67 extending in the scanning direction X. The first adjusting member 65 is fixed to the first supporting portion 21 by being screwed to the first supporting portion 21 through the first long hole 67. That is, the first adjusting member 65 can move relative to the first supporting portion 21 in the scanning direction X. In this way, the first adjusting member 65 can adjust its position relative to the first supporting portion 21 in the scanning direction X.

[0100] The second adjustment member 66 is, for example, a plate or a plate-shaped member. The second adjustment member 66 is attached to the first adjustment member 65 and the holding portion 61. The second adjustment member 66 is located between the first adjustment member 65 and the holding portion 61. The second adjustment member 66 is fixed to the holding portion 61.

[0101] The second adjusting member 66 has a second long hole 68 extending in the vertical direction Z. The second adjusting member 66 is fixed to the first adjusting member 65 by being screwed to the first adjusting member 65 through the second long hole 68. That is, the second adjusting member 66 can move relative to the first adjusting member 65 in the vertical direction Z. In this way, the second adjusting member 66 can adjust its position relative to the first adjusting member 65 in the vertical direction Z.

[0102] When the first adjustment member 65 moves in the scanning direction X relative to the first support portion 21, the electrode pair 62 moves in the scanning direction X relative to the first support portion 21. When the second adjustment member 66 moves in the vertical direction Z relative to the first adjustment member 65, the electrode pair 62 moves in the vertical direction Z relative to the first support portion 21. In this way, the position of the capacitive sensor 28 can be adjusted in the scanning direction X and the vertical direction Z by the position adjustment portion 63. In this way, the position of the electrode pair 62 can be adjusted in such a way that the electrode pair 62 is effectively in contact with the medium 99.

[0103] like Figure 1 As shown in FIG. 1 , the drying device 15 is located downstream of the printing device 14 in the conveying direction Y. The drying device 15 is a device that dries the medium 99. The drying device 15 dries the medium 99 printed by the printing device 14. The drying device 15 is an example of a processing device. That is, the printing device 15 processes the medium 99 by drying the medium 99. In the printing system 11, the printing device 14 and the drying device 15 process the medium 99 in sequence.

[0104] The drying device 15 of the first embodiment includes a second support portion 71 , a storage body 72 , a heating portion 73 , and a second control portion 74 .

[0105] The second support portion 71 is, for example, a plate-shaped member. The second support portion 71 supports the medium 99 being transported. The second support portion 71 supports the medium 99 printed by the printing device 14. The second support portion 71 of the first embodiment supports the medium 99 from below. The second support portion 71 of the first embodiment is in contact with the back surface 99B of the medium 99. The second support portion 71 is a support portion provided in the drying device 15 in the printing system 11.

[0106] The receiving body 72 is opposite to the second supporting portion 71. The receiving body 72 of the first embodiment is located above the second supporting portion 71. The receiving body 72 is, for example, a box. The receiving body 72 has an opening 75 on the surface opposite to the second supporting portion 71. Therefore, the opening 75 faces downward in the receiving body 72. The receiving body 72 receives the heating portion 73.

[0107] The heating unit 73 is opposite to the second support unit 71. The heating unit 73 of the first embodiment is located above the second support unit 71. The heating unit 73 is configured to heat the medium 99. The heating unit 73 is, for example, a heating tube extending in the scanning direction X. In the first embodiment, two heating units 73 are provided. The two heating units 73 are arranged in the conveying direction Y with a gap therebetween.

[0108] The heating unit 73 generates heat. The generated heat reaches the second support unit 71 through the opening 75. Thus, the heating unit 73 heats the medium 99 supported by the second support unit 71. At this time, the heating unit 73 heats the front surface 99A of the medium 99. The heating unit 73 heats the medium 99, thereby drying the liquid ejected to the medium 99. As a result, the medium 99 is dried.

[0109] When the heating unit 73 heats the medium 99, the amount of water contained in the medium 99 is reduced. That is, the heating unit 73 performs a process of reducing the amount of water contained in the medium 99 on the medium 99 by heating the medium 99. The heating unit 73 performs the process on the front surface 99A of the medium 99 opposite to the back surface 99B in contact with the second support unit 71. In this regard, the heating unit 73 of the first embodiment is an example of a processing unit.

[0110] The second control unit 74 controls various components of the drying device 15. For example, the second control unit 74 controls the heating unit 73. The second control unit 74 is a control unit provided in the drying device 15 in the printing system 11.

[0111] The second control unit 74 of the first embodiment is configured to be able to communicate with the holding device 12, the winding device 13, and the printing device 14. The second control unit 74 receives signals from the holding device 12, the winding device 13, and the printing device 14 as needed, or sends signals to the holding device 12, the winding device 13, and the printing device 14. The second control unit 74 communicates with the first control unit 23, for example. The second control unit 74 may also control the printing system 11 in an integrated manner.

[0112] The second control unit 74 can be configured as the following circuit similarly to the first control unit 23, the circuit including α: one or more processors that execute various processes according to a computer program, β: one or more dedicated hardware circuits such as integrated circuits for specific purposes that execute at least a part of the various processes, or γ: a combination thereof. The processor includes a CPU and a memory such as a RAM and a ROM, and the memory stores program codes or instructions configured in such a way that the CPU executes the process. The memory, i.e., the computer-readable medium, includes all readable media that can be accessed by a general-purpose or dedicated computer.

[0113] Next, the operation and effects of the first embodiment described above will be described.

[0114] (1) The moisture content of the medium 99 before the treatment is performed is detected by the first light source 42 and the first light receiving unit 43. The moisture content of the medium 99 after the treatment is performed is detected by the second light source 52 and the second light receiving unit 53. Thus, it is possible to detect a decrease in the moisture content of the medium 99 relative to the treatment, or an increase in the moisture content of the medium 99 relative to the treatment. Therefore, it is possible to detect a change in the moisture content of the medium 99 relative to the treatment.

[0115] (2) At least one of the first light source 42 and the second light source 52 has a plurality of light emitting elements that emit light having different peak wavelengths. In this case, light having different spectra is irradiated onto the medium 99. This allows the amount of water contained in the medium 99 to be detected with high accuracy.

[0116] (3) At least one of the first light source 42 and the second light source 52 has a short-wavelength light emitting element that emits light with a peak wavelength of 940 nm, and a long-wavelength light emitting element that emits light with a peak wavelength of 1450 nm. 940 nm and 1450 nm are the absorption wavelengths of water. Therefore, the light emitted by the short-wavelength light emitting element and the long-wavelength light emitting element is easily absorbed by water. Therefore, the amount of water contained in the medium 99 can be detected with high accuracy.

[0117] (4) The first light shielding portion 44 is configured to switch between a first state S1 in which the first detection light path L1 is not blocked and the first reference light path L2 is blocked, and a second state S2 in which the first detection light path L1 is blocked and the first reference light path L2 is not blocked. Thus, when the first light shielding portion 44 is in the first state S1, the light emitted by the first light source 42 enters the first light receiving portion 43 by traveling in the first detection light path L1. When the first light shielding portion 44 is in the second state S2, the light emitted by the first light source 42 enters the first light receiving portion 43 by traveling in the first reference light path L2. Based on the light traveling in the first detection light path L1 and the light traveling in the first reference light path L2, the reflectivity of the light with respect to the medium 99 is detected with high accuracy. Thus, for example, even if the first light source 42 deteriorates over time, the amount of water contained in the medium 99 can be detected with high accuracy.

[0118] (5) The second light shielding portion 54 is configured to switch between a third state S3 in which the second detection light path L3 is not blocked and the second reference light path L4 is blocked, and a fourth state S4 in which the second detection light path L3 is blocked and the second reference light path L4 is not blocked. Thus, when the second light shielding portion 54 is in the third state S3, the light emitted by the second light source 52 enters the second light receiving portion 53 by traveling in the second detection light path L3. When the second light shielding portion 54 is in the fourth state S4, the light emitted by the second light source 52 enters the second light receiving portion 53 by traveling in the second reference light path L4. Based on the light traveling in the second detection light path L3 and the light traveling in the second reference light path L4, the reflectivity of the light with respect to the medium 99 is detected with high accuracy. Thus, for example, even if the second light source 52 deteriorates over time, the amount of water contained in the medium 99 can be detected with high accuracy.

[0119] (6) The head 32 as the processing unit processes the front surface 99A of the medium 99 opposite to the back surface 99B in contact with the first support portion 21. On the other hand, the first light source 42 and the second light source 52 irradiate light to the front surface 99A. This makes it possible to detect the amount of moisture contained in the front surface 99A of the medium 99 being processed with high accuracy.

[0120] (7) The printing device 14 as a processing device includes a capacitance sensor 28 and a first ultrasonic sensor 24. The first emitting unit 34 and the first receiving unit 35 of the first ultrasonic sensor 24 are arranged so as to sandwich the medium 99 being transported. Thus, when the medium 99 is located between the first emitting unit 34 and the first receiving unit 35, the ultrasonic wave emitted by the first emitting unit 34 passes through the medium 99. In this case, the first receiving unit 35 receives the ultrasonic wave that has passed through the medium 99. When the medium 99 is not located between the first emitting unit 34 and the first receiving unit 35, the ultrasonic wave emitted by the first emitting unit 34 is directly received by the first receiving unit 35. The transmittance of the ultrasonic wave to the medium 99 is detected based on the ultrasonic wave that has not passed through the medium 99 and the ultrasonic wave that has passed through the medium 99. In addition, the gram weight of the medium 99 is detected based on the transmittance of the ultrasonic wave to the medium 99. Therefore, the amount of moisture contained in the medium 99 can be detected based on the capacitance of the medium 99 detected by the capacitance sensor 28 and the gram weight of the medium 99 detected by the first ultrasonic sensor 24. Thereby, the amount of moisture contained in the medium 99 can be detected with high accuracy.

[0121] (8) The first ultrasonic sensor 24 is attached to the carriage 33 . Therefore, the first ultrasonic sensor 24 can detect the amount of moisture contained in the medium 99 across the width of the medium 99 by scanning together with the carriage 33 .

[0122] (9) The second ultrasonic sensor 25 is attached to the carriage 33 . Therefore, the second ultrasonic sensor 25 can detect the amount of moisture contained in the medium 99 across the width of the medium 99 by scanning together with the carriage 33 .

[0123] Second embodiment

[0124] Next, the second embodiment is described. In the second embodiment, the difference from the first embodiment is that the drying device 15 includes a first ultrasonic sensor 24, a second ultrasonic sensor 25, a first optical sensor 26, a second optical sensor 27, and a capacitive sensor 28. The second embodiment is mainly described in terms of the differences from the first embodiment.

[0125] like Figure 8 As shown, the drying device 15 includes a second support portion 71, a storage body 72, a heating portion 73, and a second control portion 74. The drying device 15 of the second embodiment includes a first ultrasonic sensor 24 and a second ultrasonic sensor 25. The drying device 15 of the second embodiment includes a first optical sensor 26 and a second optical sensor 27. The drying device 15 of the second embodiment includes a capacitive sensor 28.

[0126] The second support part 71 of the second embodiment has a mounting hole 31 for mounting the capacitance sensor 28. The mounting hole 31 is located in a region of the second support part 71 facing the storage body 72. The mounting hole 31 of the second embodiment is located between the two heating parts 73 in the conveying direction Y.

[0127] The first ultrasonic sensor 24 of the second embodiment is located downstream of the second support portion 71 in the conveying direction Y. The first ultrasonic sensor 24 of the second embodiment is located between the second support portion 71 and the winding device 13 in the conveying direction Y.

[0128] The first ultrasonic sensor 24 detects the grammage of the medium 99 after being processed by the heating unit 73. That is, the first ultrasonic sensor 24 detects the grammage of the heated medium 99. Thus, when the first ultrasonic sensor 24 detects the grammage of the medium 99, the influence of the liquid ejected from the head 32 to the medium 99 is reduced. The reason is that when a large amount of liquid is contained in the medium 99, it is difficult to detect the grammage of the medium 99 with high accuracy.

[0129] The second ultrasonic sensor 25 of the second embodiment is opposite to the second support portion 71. The second ultrasonic sensor 25 is located above the second support portion 71. The second ultrasonic sensor 25 of the second embodiment is located downstream of the heating portion 73 in the conveying direction Y. The second ultrasonic sensor 25 of the second embodiment is located between the storage body 72 and the first ultrasonic sensor 24 in the conveying direction Y.

[0130] The second ultrasonic sensor 25 detects the thickness of the medium 99 after being processed by the heating unit 73. That is, the second ultrasonic sensor 25 detects the gram weight of the heated medium 99. Thus, when the second ultrasonic sensor 25 detects the thickness of the medium 99, the influence of the liquid ejected to the medium 99 is reduced. The reason is that when a large amount of liquid is contained in the medium 99, the medium 99 may swell, and therefore it is difficult to detect the thickness of the medium 99 with high accuracy.

[0131] The first optical sensor 26 of the second embodiment is located upstream of the heating unit 73 in the conveying direction Y. The first optical sensor 26 of the second embodiment is located upstream of the storage body 72 in the conveying direction Y. The first optical sensor 26 faces the first support unit 71. The first optical sensor 26 is located above the second support unit 71.

[0132] The first optical sensor 26 detects the amount of moisture contained in the medium 99 before being heated by the heating unit 73. That is, the first optical sensor 26 detects the amount of moisture contained in the medium 99 before being processed by the heating unit 73. More specifically, the first optical sensor 26 detects the amount of moisture contained in the medium 99 after the liquid is ejected. Therefore, the first light source 42 irradiates light to the medium 99 before being heated by the heating unit 73. The first light receiving unit 43 receives light reflected from the medium 99 before being heated by the heating unit 73.

[0133] The second optical sensor 27 of the second embodiment is located downstream of the heating unit 73 in the conveying direction Y. The second optical sensor 27 of the second embodiment is located upstream of the storage body 72 in the conveying direction Y. The second optical sensor 27 faces the second support unit 71. The second optical sensor 27 is located above the second support unit 71.

[0134] The second optical sensor 27 detects the amount of moisture contained in the medium 99 after being heated by the heating unit 73. That is, the second optical sensor 27 detects the amount of moisture contained in the medium 99 after being processed by the heating unit 73. Therefore, the second light source 52 irradiates light to the medium 99 after being heated by the heating unit 73. The second light receiving unit 53 receives light reflected from the medium 99 after being heated by the heating unit 73.

[0135] The first optical sensor 26 and the second optical sensor 27 detect changes in the amount of moisture contained in the medium 99 in response to the treatment performed by the treatment unit on the medium 99. That is, in the second embodiment, a decrease in the amount of moisture contained in the medium 99 in response to the heating of the medium 99 by the heating unit 73 is detected.

[0136] The capacitance sensor 28 of the second embodiment is mounted on the second support portion 71. The capacitance sensor 28 of the second embodiment is mounted on the mounting hole 31. The capacitance sensor 28 is located, for example, between the first optical sensor 26 and the second optical sensor 27 in the conveying direction Y. The capacitance sensor 28 of the second embodiment is located between the two heating portions 73 in the conveying direction Y.

[0137] The capacitance sensor 28 of the second embodiment detects the amount of moisture contained in the medium 99 during the process of being heated by the heating unit 73. That is, the capacitance sensor 28 detects the amount of moisture contained in the medium 99 during the process of being processed by the heating unit 73. The capacitance sensor 28 detects the amount of moisture contained in the medium 99 during the process.

[0138] The first optical sensor 26, the second optical sensor 27, and the capacitance sensor 28 detect the change in the amount of water contained in the medium in response to the process, thereby accurately detecting the amount of water contained in the medium 99 reduced by the heating unit 73.

[0139] When the heating unit 73 heats the medium 99, there is a case where the front surface 99A is dried, but the inside of the medium 99 is not dried. In this case, when referring to the detection results of the first optical sensor 26 and the detection results of the second optical sensor 27, it can be understood that the amount of water contained in the medium 99 is reduced greatly relative to the heat applied to the medium 99 by the heating unit 73. On the other hand, when referring to the detection results of the first optical sensor 26 and the detection results of the capacitance sensor 28, it can be understood that the amount of water contained in the medium 99 is reduced less relative to the heat applied to the medium 99 by the heating unit 73. Based on this, it can be understood that the medium 99 has a characteristic that is difficult to dry. In this way, the characteristics of the medium 99 can be understood based on the detection results of the first optical sensor 26, the detection results of the second optical sensor 27, and the detection results of the capacitance sensor 28.

[0140] According to the second embodiment described above, in addition to the same effects as those of the first embodiment, the following effects can be obtained.

[0141] (10) The heating unit 73 as the processing unit processes the front surface 99A of the medium 99 opposite to the back surface 99B in contact with the first support unit 21. On the other hand, the first light source 42 and the second light source 52 irradiate light to the front surface 99A. Thus, the amount of moisture contained in the front surface 99A of the processed medium 99 can be detected with high accuracy.

[0142] (11) The printing device 15 as a processing device includes a capacitance sensor 28 and a first ultrasonic sensor 24. The first emitting unit 34 and the first receiving unit 35 of the first ultrasonic sensor 24 are arranged so as to sandwich the medium 99 being transported. When the medium 99 is located between the first emitting unit 34 and the first receiving unit 35, the ultrasonic wave emitted by the first emitting unit 34 passes through the medium 99. In this case, the first receiving unit 35 receives the ultrasonic wave after passing through the medium 99. When the medium 99 is not located between the first emitting unit 34 and the first receiving unit 35, the ultrasonic wave emitted by the first emitting unit 34 is directly received by the first receiving unit 35. The transmittance of the ultrasonic wave with respect to the medium 99 is detected based on the ultrasonic wave that has not passed through the medium 99 and the ultrasonic wave that has passed through the medium 99. In addition, the gram weight of the medium 99 is detected based on the transmittance of the ultrasonic wave with respect to the medium 99. Therefore, the amount of moisture contained in the medium 99 can be detected based on the capacitance of the medium 99 detected by the capacitance sensor 28 and the gram weight of the medium 99 detected by the first ultrasonic sensor 24. Thereby, the amount of moisture contained in the medium 99 can be detected with high accuracy.

[0143] The first embodiment and the second embodiment described above can be modified and implemented as follows. The first embodiment, the second embodiment, and the following modified examples can be implemented in combination with each other within a range that does not technically contradict each other.

[0144] - Instead of the mounting hole 31, a recessed portion may be provided in the support portion.

[0145] The first emitting unit 34 may constitute both the first ultrasonic sensor 24 and the second ultrasonic sensor 25. That is, the first emitting unit 34 may also function as the second emitting unit 36. In this case, for example, the first emitting unit 34 moves in the conveying direction Y and the opposite direction thereof. Thus, the first emitting unit 34 can emit ultrasonic waves to the first receiving unit 35 and emit ultrasonic waves to the supporting unit.

[0146] In the second embodiment, the first ultrasonic sensor 24 and the second ultrasonic sensor 25 may also be located at the same position as in the first embodiment. Compared with the case where the ultrasonic wave is irradiated to the medium 99 after the liquid is ejected, the gram weight and thickness of the medium 99 can be detected with higher accuracy when the ultrasonic wave is irradiated to the medium 99 before the liquid is ejected.

[0147] The first light shielding portion 44 may be configured to shield the first detection optical path L1 by blocking the first opening 45. For example, the first light shielding portion 44 may reflect the light emitted by the first light source 42 so that the light enters the first light receiving portion 43. In this case, the first light shielding portion 44 may not have the first hole 49.

[0148] The second light shielding portion 54 may be configured to block the second detection optical path L3 by blocking the second opening 55. For example, the second light shielding portion 54 may reflect the light emitted by the second light source 52 so that the light enters the second light receiving portion 53. In this case, the second light shielding portion 54 may not have the second hole 59.

[0149] The first state S1 may be a state in which the amount of light passing through the first detection optical path L1 is greater than the amount of light passing through the first reference optical path L2. In this case, the first light shielding portion 44 in the first state S1 shields more light passing through the first reference optical path L2 than light passing through the first detection optical path L1.

[0150] The second state S2 may be a state in which the amount of light passing through the first reference optical path L2 is greater than the amount of light passing through the first detection optical path L1. In this case, the first light shielding portion 44 in the second state S2 shields more light passing through the first detection optical path L1 than light passing through the first reference optical path L2.

[0151] The third state S3 may be a state in which the amount of light passing through the second detection optical path L3 is greater than the amount of light passing through the second reference optical path L4. In this case, the second light shielding portion 54 in the third state S3 shields more light passing through the second reference optical path L4 than light passing through the second detection optical path L3.

[0152] The fourth state S4 may be a state in which the amount of light passing through the second reference optical path L4 is greater than the amount of light passing through the second detection optical path L3. In this case, the second light shielding portion 54 in the fourth state S4 shields more light passing through the second detection optical path L3 than light passing through the second reference optical path L4.

[0153] The first light source 42 may also be configured to emit light including wavelengths that are easily absorbed by water and wavelengths that are difficult to be absorbed by water. In this case, the reflectivity of the light with respect to the medium 99 can be calculated by comparing the intensity of the light with respect to the wavelengths that are easily absorbed by water and the intensity of the light with respect to the wavelengths that are difficult to be absorbed by water among the light reflected by the medium 99. In this way, even if the light is not directly incident from the first light source 42 to the first light receiving unit 43, the reflectivity of the light with respect to the medium 99 can be calculated.

[0154] The first light source 42 may include only the first light emitting element 46 or only the second light emitting element 47. That is, the first light source 42 may include only the short-wavelength light emitting element emitting light with a peak wavelength of 940 nm or only the long-wavelength light emitting element emitting light with a peak wavelength of 1450 nm.

[0155] The second light source 52 may also be configured to emit light including wavelengths that are easily absorbed by water and wavelengths that are difficult to be absorbed by water. In this case, the reflectivity of light with respect to the medium 99 can be calculated by comparing the intensity of the light with respect to the wavelength that is easily absorbed by water and the intensity of the light with respect to the wavelength that is difficult to be absorbed by water among the light reflected at the medium 99. In this way, even if the light from the second light source 52 is not directly incident on the second light receiving unit 53, the reflectivity of light with respect to the medium 99 can be calculated.

[0156] The second light source 52 may include only the third light emitting element 56 or only the fourth light emitting element 57. That is, the second light source 52 may include only the short-wavelength light emitting element emitting light with a peak wavelength of 940 nm or only the long-wavelength light emitting element emitting light with a peak wavelength of 1450 nm.

[0157] The capacitance sensor 28 may be located at a position for detecting the amount of moisture contained in the medium before the treatment. The capacitance sensor 28 may be located at a position not affected by the light emitted by the first optical sensor 26 and the second optical sensor 27 .

[0158] The position adjustment unit 63 may be configured to be able to adjust the position of the electrode pair 62 by electrical driving. For example, the position adjustment unit 63 may be an actuator.

[0159] The position adjustment unit 63 may be configured to be able to adjust the position of the electrode pair 62 relative to the holding unit 61. In this case, the position of the electrode pair 62 relative to the support unit can also be adjusted.

[0160] The drying device 15 may include an air supply unit that supplies air to the medium 99 instead of the heating unit 73. In this case, the air supply unit corresponds to the processing unit. By blowing air to the medium 99, the drying of the medium 99 is also promoted.

[0161] The drying device 15 may include an air supply unit for supplying air toward the medium 99 in addition to the heating unit 73. In this case, the heating unit 73 and the air supply unit correspond to the processing unit. In addition to heating the medium 99, air is blown toward the medium 99, thereby further promoting the drying of the medium 99.

[0162] The following describes the technical ideas and effects grasped from the above-mentioned embodiment and modified examples.

[0163] (A) The processing device comprises: a first light source and a second light source, each emitting light having a peak wavelength within a range of 900 nm to 2100 nm; a first light receiving unit, receiving the light emitted by the first light source; a second light receiving unit, receiving the light emitted by the second light source; a support unit, supporting a medium to be transported; and a processing unit, which is opposed to the support unit and performs a process on the medium to increase or decrease the amount of water contained in the medium, wherein the first light source and the first light receiving unit are located upstream of the processing unit in a transport direction of the medium to be transported, the first light source irradiates light onto the medium before the medium is processed by the processing unit, and the first light receiving unit receives light reflected from the medium, and the second light source and the second light receiving unit are located downstream of the processing unit in the transport direction, the second light source irradiates light onto the medium after the medium is processed by the processing unit, and the second light receiving unit receives light reflected from the medium.

[0164] When light is irradiated to a medium, the reflectivity of the light reflected at the medium changes depending on the amount of moisture contained in the medium. That is, the amount of moisture contained in the medium can be detected based on the reflectivity of the light reflected at the medium. According to the above structure, the amount of moisture contained in the medium before the treatment is performed is detected using the first light source and the first light receiving unit. The amount of moisture contained in the medium after the treatment is performed is detected using the second light source and the second light receiving unit. Thereby, the decrease in the amount of moisture contained in the medium relative to the treatment, or the increase in the amount of moisture contained in the medium relative to the treatment can be detected. Therefore, the change in the amount of moisture contained in the medium relative to the treatment can be detected.

[0165] (B) In the above processing device, at least one of the first light source and the second light source may include a plurality of light emitting elements that emit light having different peak wavelengths.

[0166] According to the above configuration, light having different spectra is irradiated onto the medium, thereby making it possible to detect the amount of water contained in the medium with high accuracy.

[0167] (C) In the above-mentioned processing device, at least one of the first light source and the second light source may have a short-wavelength light-emitting element emitting light with a peak wavelength of 940 nm and a long-wavelength light-emitting element emitting light with a peak wavelength of 1450 nm.

[0168] 940nm and 1450nm are the absorption wavelengths of water. Therefore, the light emitted by the short-wavelength light-emitting element and the long-wavelength light-emitting element is easily absorbed by water. Therefore, according to the above structure, the amount of water contained in the medium can be detected with high accuracy.

[0169] (D) The above-mentioned processing device can also be constructed to have a first light shielding portion for shielding light emitted by the first light source, the light emitted by the first light source travels in a first detection light path or a first reference light path, the first detection light path is a light path in which the light emitted by the first light source is reflected at the medium supported by the supporting portion and is incident on the first light receiving portion, the first reference light path is a light path in which the light emitted by the first light source is incident on the first light receiving portion without being reflected at the medium supported by the supporting portion, and the first light shielding portion is configured to switch between a first state in which the first detection light path is not blocked and the first reference light path is blocked, and a second state in which the first detection light path is blocked and the first reference light path is not blocked.

[0170] According to the above structure, when the first light shielding portion is in the first state, the light emitted by the first light source enters the first light receiving portion by traveling in the first detection light path. When the first light shielding portion is in the second state, the light emitted by the first light source enters the first light receiving portion by traveling in the first reference light path. Based on the light traveling in the first detection light path and the light traveling in the first reference light path, the reflectivity of the light relative to the medium is detected with high precision. Thus, for example, even if the first light source deteriorates over time, the amount of water contained in the medium can be detected with high precision.

[0171] (E) The above-mentioned processing device can also be constructed to have a second light shielding portion for shielding light emitted by the second light source, the light emitted by the second light source travels in a second detection light path or a second reference light path, the second detection light path is a light path in which the light emitted by the second light source is reflected at the medium supported by the supporting portion and is incident on the second light receiving portion, the second reference light path is a light path in which the light emitted by the second light source is incident on the second light receiving portion without being reflected at the medium supported by the supporting portion, and the second light shielding portion is constructed to switch between a third state in which the second detection light path is not blocked and the second reference light path is blocked, and a fourth state in which the second detection light path is blocked and the second reference light path is not blocked.

[0172] According to the above structure, when the second light shielding portion is in the third state, the light emitted by the second light source enters the second light receiving portion by traveling in the second detection light path. When the second light shielding portion is in the fourth state, the light emitted by the second light source enters the second light receiving portion by traveling in the second reference light path. Based on the light traveling in the second detection light path and the light traveling in the second reference light path, the reflectivity of the light relative to the medium is detected with high accuracy. Thus, for example, even if the second light source deteriorates over time, the amount of water contained in the medium can be detected with high accuracy.

[0173] (F) In the above processing device, the processing section may process the front side of the medium opposite to the back side in contact with the support section, and the first light source and the second light source may irradiate light toward the front side.

[0174] According to the above configuration, the amount of moisture contained in the front surface of the medium to be processed can be detected with high accuracy.

[0175] (G) The processing device may also adopt the following structure, that is, it comprises: a capacitive sensor having an electrode pair and detecting the capacitance of the medium in contact with the electrode pair; an ultrasonic sensor having an emitting unit for emitting ultrasonic waves and a receiving unit for receiving the ultrasonic waves emitted by the emitting unit, wherein the emitting unit and the receiving unit are arranged in a manner that separates the medium being transported.

[0176] When there is a medium between the emitting part and the receiving part, the ultrasonic wave emitted by the emitting part passes through the medium. In this case, the receiving part receives the ultrasonic wave after passing through the medium. When there is no medium between the emitting part and the receiving part, the ultrasonic wave emitted by the emitting part is directly received by the receiving part. The transmittance of the ultrasonic wave with respect to the medium is detected based on the ultrasonic wave that has not passed through the medium and the ultrasonic wave that has passed through the medium. The gram weight of the medium is detected based on the transmittance of the ultrasonic wave with respect to the medium. Therefore, according to the above structure, the amount of moisture contained in the medium can be detected based on the capacitance of the medium detected by the capacitive sensor and the gram weight of the medium detected by the ultrasonic sensor. Thereby, the amount of moisture contained in the medium can be detected with high precision.

[0177] Explanation of symbols

[0178] 11…printing system; 12…holding device; 13…winding device; 14…printing device; 15…drying device; 17…holding shaft; 18…winding shaft; 21…first supporting part; 22…printing part; 23…first control part; 24…first ultrasonic sensor; 25…second ultrasonic sensor; 26…first optical sensor; 27…second optical sensor; 28…capacitive sensor; 31…mounting hole; 32…head; 33…slide; 34…first sending part; 35…first receiving part; 36…second sending part; 37…second receiving part; 41…first housing; 42…first light source; 43…first light receiving part; 44…first light shielding part; 45…first opening; 46…first light emitting element; 47…second light emitting element; 48…first rotating shaft; 49…first hole; 51…second housing; 52…second light source; 53…second light receiving part; 54…first light shielding part; 55…first light shielding part; 56…first light emitting element; 57…second light emitting element; 58…first rotating shaft; 59…first hole; 60…second housing; 61…second light source; 62…second light receiving part; 63…second light receiving part; 64…second light shielding part; 65…first light shielding part; 66…first light emitting element; 67…second light emitting element; 68…first rotating shaft; 69…first hole; 70…second housing; 71…second light source; 72…second light receiving part; 73…second light shielding part; 74…first light shielding part; 75…first light shielding part; 76…first light shielding part; 77…second light shielding part; 78…first light shielding part; 79…first light shielding part 4…second light shielding portion; 55…second opening; 56…third light emitting element; 57…fourth light emitting element; 58…second rotating shaft; 59…second hole; 61…holding portion; 62…electrode pair; 63…position adjusting portion; 64…electrode; 65…first adjusting member; 66…second adjusting member; 67…first long hole; 68…second long hole; 71…second supporting portion; 72…accommodating body; 73…heating portion; 74…second control portion; 75…opening; 99…medium; 99A…front side; 99B…back side; 100…roll body; D1…first direction; D2…second direction; L1: first detection optical path; L2…first reference optical path; L3…second detection optical path; L4…second reference optical path; S1…first state; S2…second state; S3…third state; S4…fourth state; X…scanning direction; Y…transport direction; Z…vertical direction.

Claims

1. A processing device comprising: The first light source and the second light source emit light having a peak wavelength in the range of 900 nm to 2100 nm; A first light receiving part, which receives light emitted by the first light source; A second light receiving part, which receives the light emitted by the second light source; A supporting part, which supports the medium being transported; a processing unit which is opposed to the support unit and performs a process on the medium to increase or decrease the amount of water contained in the medium, The first light source and the first light receiving unit are located upstream of the processing unit in the conveying direction of the medium being conveyed. The first light source irradiates light to the medium before being processed by the processing unit. The first light receiving unit receives the light reflected from the medium. The second light source and the second light receiving unit are located downstream of the processing unit in the conveying direction. The second light source irradiates light to the medium after being processed by the processing unit. The second light receiving unit receives the light reflected from the medium. The processing device includes a first light shielding portion for shielding light emitted by the first light source. The light emitted by the first light source travels in a first detection light path or a first reference light path, the first detection light path is a light path in which the light emitted by the first light source is reflected by the medium supported by the support portion and is incident on the first light receiving portion, and the first reference light path is a light path in which the light emitted by the first light source is incident on the first light receiving portion without being reflected by the medium supported by the support portion. The first light shielding portion is configured to switch between a first state in which the first detection light path is not blocked and the first reference light path is blocked, and a second state in which the first detection light path is blocked and the first reference light path is not blocked.

2. A processing device comprising: The first light source and the second light source emit light having a peak wavelength in the range of 900 nm to 2100 nm; A first light receiving part, which receives light emitted by the first light source; A second light receiving part, which receives the light emitted by the second light source; A supporting part, which supports the medium being transported; a processing unit which is opposed to the support unit and performs a process on the medium to increase or decrease the amount of water contained in the medium, The first light source and the first light receiving unit are located upstream of the processing unit in the conveying direction of the medium being conveyed. The first light source irradiates light to the medium before being processed by the processing unit. The first light receiving unit receives the light reflected from the medium. The second light source and the second light receiving unit are located downstream of the processing unit in the conveying direction. The second light source irradiates light to the medium after being processed by the processing unit. The second light receiving unit receives the light reflected from the medium. The processing device includes a second light shielding portion for shielding light emitted by the second light source. The light emitted by the second light source travels in a second detection light path or a second reference light path, the second detection light path is a light path in which the light emitted by the second light source is reflected at the medium supported by the support portion and is incident on the second light receiving portion, and the second reference light path is a light path in which the light emitted by the second light source is incident on the second light receiving portion without being reflected at the medium supported by the support portion. The second light shielding portion is configured to switch between a third state in which the second detection light path is not blocked and the second reference light path is blocked, and a fourth state in which the second detection light path is blocked and the second reference light path is not blocked.

3. The processing device according to claim 1 or 2, wherein: At least one of the first light source and the second light source includes a plurality of light emitting elements that emit light having different peak wavelengths.

4. The processing device according to claim 3, wherein: At least one of the first light source and the second light source includes a short-wavelength light emitting element that emits light with a peak wavelength of 940 nm and a long-wavelength light emitting element that emits light with a peak wavelength of 1450 nm.

5. The processing device according to claim 1 or 2, wherein: The processing unit processes the front side of the medium opposite to the back side in contact with the supporting unit. The first light source and the second light source irradiate light toward the front surface.

6. The processing device according to claim 1 or 2, wherein: have: A capacitive sensor having an electrode pair and detecting the capacitance of the medium in contact with the electrode pair; The ultrasonic sensor comprises a transmitter for transmitting ultrasonic waves and a receiver for receiving the ultrasonic waves transmitted by the transmitter. The emission unit and the reception unit are provided so as to sandwich the medium to be transported.

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