Drying device

Abstract

The purpose of the present invention is to provide a drying device in which formation of drying unevenness of a coating film can be suppressed. Specifically, the drying device includes a heating mechanism including a radiation heating part for heating a coating film formed on a conveyed base material by radiation heat, and dries the coating film by heating the coating film by the heating mechanism. The drying device further includes a measurement part for measuring a temperature of the coating film. The heating mechanism is configured to adjust the total sum of heat energy applied to a predetermined portion of the coating film on the basis of a measurement result obtained by the measurement part.

Description

Drying Device

[0001] The present invention relates to a drying device for drying a coating film formed on a substrate.

[0002] A lithium-ion battery forms a positive electrode and a negative electrode by applying a slurry of an electrode material to a sheet-like substrate such as an aluminum foil or a copper foil conveyed in a roll-to-roll manner to form a coating film and drying the formed coating film.

[0003] As an example of a drying device for drying a coating film, Patent Document 1 below discloses a device including a housing portion in which a coating film formed on a substrate is heated inside, and a heating portion that irradiates the coating film with far infrared rays inside the housing portion to heat the coating film. That is, the drying device disclosed in Patent Document 1 below dries the coating film by heating the coating film with radiant heat.

[0004] Japanese Patent No. 7285360

[0005] However, in the above drying device, drying unevenness may be formed in the coating film. Specifically, in the above drying device, the ambient temperature inside the housing portion increases due to the radiant heat for heating the coating film, so the total amount of thermal energy applied to the coating film changes over time, and heating unevenness occurs in the coating film. As a result, there is a problem that drying unevenness is formed in the coating film.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a drying device capable of suppressing the formation of drying unevenness in a coating film.

[0007] The drying device of the present invention for solving the above problems includes a heating mechanism including a radiant heating portion that heats a coating film formed on a conveyed substrate with radiant heat, and dries the coating film by heating the coating film with the heating mechanism. The drying device further includes a measuring portion that measures the temperature of the coating film, and the heating mechanism is characterized in that it adjusts the total amount of thermal energy applied to a predetermined portion of the coating film based on the measurement result by the measuring portion.

[0008] According to the above drying apparatus, the total amount of thermal energy applied to a predetermined part of the coating film by the heating mechanism is adjusted based on the temperature of the coating film measured by the measuring unit, making it possible to heat the coating film to the desired temperature. This suppresses the formation of uneven drying in the coating film.

[0009] Furthermore, the radiant heating unit may have an irradiation unit that heats the coating film by irradiating it with a laser, and the heating mechanism may be configured to adjust the laser irradiation time of a predetermined location on the coating film by the irradiation unit based on the measurement results from the measurement unit.

[0010] With this configuration, by adjusting the time the laser is irradiated onto the coating film from the irradiation unit based on the temperature of the coating film measured by the measurement unit, it becomes possible to heat the coating film to the desired temperature without adjusting the intensity of the irradiated laser. This suppresses uneven heating in the thickness direction of the coating film that occurs when adjusting the intensity of the irradiated laser, and thus further suppresses the formation of uneven drying in the coating film.

[0011] Furthermore, as a specific embodiment, it is preferable that the irradiation unit is configured to irradiate with a laser using a pulsed waveform with a controlled duty cycle.

[0012] Furthermore, a blocking section is provided between the substrate and the irradiation section to block the laser irradiated from the irradiation section, and the heating mechanism may be configured to adjust the arrangement of the blocking section based on the measurement results from the measurement section.

[0013] With this configuration, the laser irradiation range can be adjusted by adjusting the arrangement of the blocking section based on the temperature of the coating measured by the measuring section, thereby adjusting the time that the laser irradiates a predetermined location on the coating.

[0014] Furthermore, the heating mechanism may include a housing portion in which the coating film is heated internally, and a hot air supply portion that supplies hot air to the housing portion, and the temperature of the hot air supplied to the housing portion by the hot air supply portion may be adjusted based on the measurement results from the measuring portion.

[0015] With this configuration, the temperature of the hot air supplied from the hot air supply unit into the housing is adjusted based on the temperature of the coating measured by the measurement unit. This makes it possible to adjust the thermal energy applied to the coating without adjusting the intensity of the laser irradiated from the irradiation unit. As a result, uneven heating in the thickness direction of the coating that occurs when adjusting the intensity of the irradiating laser can be suppressed, and thus the formation of uneven drying in the coating can be further suppressed.

[0016] Furthermore, the heating mechanism may be further equipped with a fracture detection unit for detecting fracture of the substrate, and when the fracture detection unit detects fracture of the substrate, the irradiation unit may be configured to immediately stop the irradiation of the laser.

[0017] With this configuration, when the fracture detection unit detects a fracture in the substrate, the irradiation unit immediately stops the laser irradiation, thus preventing the laser from irradiating equipment located on the opposite side of the substrate from the surface being irradiated. This prevents equipment failure.

[0018] Furthermore, the radiant heating unit may have an irradiation unit that heats the coating film by irradiating it with a laser, and the heating mechanism may be configured to adjust the intensity of the laser irradiated by the irradiation unit based on the measurement results from the measurement unit.

[0019] With this configuration, the intensity of the laser irradiated onto the coating from the irradiation unit is adjusted based on the temperature of the coating measured by the measurement unit, making it possible to heat the coating to the desired temperature. This suppresses the formation of uneven drying in the coating.

[0020] Furthermore, the irradiation unit may have a zoom lens with variable magnification, and the irradiation range of the laser may be adjusted by changing the magnification of the zoom lens.

[0021] With this configuration, the intensity of the laser irradiated onto the coating can be adjusted by changing the magnification of the zoom lens based on the temperature of the coating measured by the measurement unit, thereby adjusting the laser irradiation range and the density of the laser per unit area irradiated onto the coating.

[0022] Furthermore, a damping section is provided between the substrate and the irradiation section to attenuate the laser irradiated from the irradiation section, and the damping section may be configured to allow adjustment of the amount of laser attenuation.

[0023] With this configuration, the intensity of the laser irradiated onto the coating can be adjusted by attenuating the laser irradiated by the attenuation unit.

[0024] According to the drying apparatus of the present invention, it is possible to suppress the formation of uneven drying in the coating film.

[0025] This figure shows a coating apparatus equipped with a drying device according to one embodiment of the present invention. This is a cross-sectional view of the drying device in the first embodiment of the present invention. This is a diagram illustrating the drying device in the first embodiment of the present invention. This is a diagram illustrating the drying device in the first embodiment of the present invention. This is a diagram illustrating the drying device in the second embodiment of the present invention.

[0026] [First Embodiment] The drying apparatus in this embodiment will be described with reference to the drawings. In the following description, the three axes of the Cartesian coordinate system are X, Y, and Z, the horizontal direction is expressed as the X-axis direction and the Y-axis direction, and the direction perpendicular to the XY plane (i.e., the vertical direction) is expressed as the Z-axis direction.

[0027] Figure 1 is a schematic diagram showing a coating apparatus 100 equipped with a drying apparatus 4 according to one embodiment of the present invention. Figure 2 is a cross-sectional view of the drying apparatus 4 according to one embodiment of the present invention, with a portion shown in an enlarged view. Figures 3 and 4 are diagrams for explaining the drying apparatus 4 in the first embodiment of the present invention, where Figure 3 shows the case of adjusting the irradiation time of the laser 44 to a predetermined location on the coating film 11, and Figure 4 shows the case of adjusting the intensity of the laser 44 irradiated to a predetermined location on the coating film 11. Note that in Figures 3 and 4, the coating film 11 formed on the back surface of the substrate 1 and the irradiation unit 45b that irradiates the coating film 11 with the laser 44 are omitted.

[0028] As shown in Figure 1, the coating apparatus 100 includes a transport device 2 for continuously transporting the substrate 1, a coating mechanism 3 for applying a coating liquid to both sides of the substrate 1 to form a coating film 11 (see Figure 3(a)), and a drying device 4 for heating and drying the coating film 11 formed on the substrate 1. The coating mechanism 3 applies the coating liquid, which is the electrode material, to both sides of the substrate 1 transported by the transport device 2 to form a coating film 11, and the drying device 4 heats and dries the formed coating film 11, thereby forming the positive or negative electrode of a lithium-ion battery.

[0029] The base material 1 is a metal foil that serves as the electrode plate for a lithium-ion battery. When it forms the positive electrode, aluminum foil or the like is used, and when it forms the negative electrode, copper foil or the like is used. This base material 1 is a long, strip-shaped sheet and is transported by the transport device 2 so that it passes through each part that makes up the coating device 100.

[0030] The coating solution is, for example, a slurry obtained by mixing an active material, a binder, and a conductive additive with a solvent, and is used as the material for the electrode plates of a lithium-ion battery (so-called electrode material). This coating solution is applied to both sides of the substrate 1 by the coating mechanism 3, thereby forming a coating film 11.

[0031] The conveying device 2 is for continuously conveying the substrate 1 in its longitudinal direction. This conveying device 2 has an unwinding roll 21, a winding roll 22, a plurality of conveying rolls 23, and a coating roll 24. These rolls are formed in a cylindrical shape and rotate around the central axis of the cylinder as the axis of rotation.

[0032] The unwinding roll 21 is for unwinding the base material 1 downstream, and its rotation is driven and controlled by a control unit (not shown), unwinding the base material 1 at a predetermined speed. The control unit is, for example, composed of a general-purpose computer device, and will be treated similarly in the following description. The winding roll 22 is for winding the base material 1, and its rotation is driven and controlled by the control unit, similar to the unwinding roll 21, winding the base material 1 while applying a predetermined tension to it. The tension referred to here is the tension in the conveying direction of the base material 1.

[0033] The conveyor rolls 23 are used to transport the substrate 1 from the unwinding roll 21 to the winding roll 22. Multiple conveyor rolls 23 are provided and are arranged so that the substrate 1 passes through each part of the coating apparatus 100. Some or all of these conveyor rolls 23 are driven and controlled by a control unit, similar to the unwinding roll 21 and the winding roll 22, to transport the substrate 1 while applying a predetermined tension to it.

[0034] The coating roll 24 is used to guide the substrate 1 to the position where the coating liquid will be applied by the coating mechanism 3. The coating roll 24 is positioned opposite the die 31 that dispenses the coating liquid and supports the substrate 1 from the back side with a predetermined gripping angle. This allows the substrate 1 to be transported while maintaining a constant distance from the die 31.

[0035] With this configuration, the conveying device 2 continuously conveys the base material 1 at a predetermined speed while applying a predetermined tension to the base material 1.

[0036] The coating mechanism 3 is for applying a coating liquid to both sides of the substrate 1 to form a coating film 11. This coating mechanism 3 has a first coating section 31 for applying the coating liquid to the surface of the substrate 1 and a second coating section 32 for applying the coating liquid to the back surface of the substrate 1.

[0037] The first coating section 31 is formed to be elongated in one direction and is provided to extend in the width direction (hereinafter referred to as the width direction) perpendicular to the transport direction of the substrate 1 in the in-plane direction of the substrate 1. The coating roll 24 is positioned at a predetermined distance from the first coating section 31 such that the rotation axis direction of the coating roll 24 is parallel to the longitudinal direction of the first coating section 31.

[0038] Furthermore, the first coating section 31 is composed of a manifold 34, which is connected to the supply passage 33 and is a space that stores coating liquid in a long widthwise direction; a slit 35 that is wide in the widthwise direction and connected to the manifold 34; and a discharge port 36 that opens to the same length as the slit 35 in the widthwise direction and discharges the coating liquid. As a result, the coating liquid stored in the manifold 34 is discharged from the discharge port 36 to the substrate 1 via the slit 35. The discharge port 36 is opposite the coating roll 24 and the substrate 1, with the substrate 1 in between. That is, the discharge port 36 is opposite the substrate 1 on the surface side of the substrate 1. As a result, the coating liquid can be applied to the substrate 1 while maintaining a constant distance between the discharge port 36 and the substrate 1, so that a coating film 11 with a uniform thickness can be formed on the surface of the substrate 1.

[0039] The supply channel 33 connects the manifold 34 to the tank 37 where the coating liquid is stored. The coating liquid is supplied from the tank 37 to the manifold 34 via the supply channel 33 by a pump (not shown), and is applied to the substrate 1 through the discharge port 36 via the slit 35. As a result, a coating film 11 is formed on the surface of the substrate 1.

[0040] The second coating section 32 has a similar configuration to the first coating section 31, and its discharge port 36 is positioned downstream of the first coating section 31, facing the substrate 1 on the back side of the substrate 1. By applying the coating liquid with this second coating section 32, a coating film 11 is formed on the back surface of the substrate 1. The width of the coating film 11 formed on the back surface of the substrate 1 by the second coating section 32 is preferably the same as the width of the coating film 11 formed on the surface of the substrate 1 by the first coating section 31.

[0041] The first coating portion 31 and the second coating portion 32 form a coating film 11 on both sides of the substrate 1.

[0042] A drying device 4 is provided downstream of the coating mechanism 3. The drying device 4 is used to heat and dry the coating film 11 formed on both sides of the substrate 1, and comprises a housing section 41 in which the coating film 11 is heated, and a heating mechanism for heating the coating film 11.

[0043] The housing part 41 is a box body formed long in the conveying direction of the base material 1, and has a space inside the box body through which the base material 1 passes and an entrance / exit for the base material 1 to enter and exit this space. A plurality of such housing parts 41 are provided, and the housing parts 41 are arranged in communication along the conveying path of the base material 1. In the example of FIG. 1, one housing part 41a and three housing parts 41b arranged downstream thereof are described, but more housing parts 41 may be provided. Then, the base material 1 conveyed by the conveying device 2 continuously passes through the interiors of the housing parts 41a and 41b, so that the coating film 11 is heated. Incidentally, when there is no particular need to distinguish between the housing parts 41a and 41b, they are simply referred to as the housing part 41.

[0044] The heating mechanism is for heating the coating film 11. This heating mechanism includes a radiation heating part 42 that heats the coating film 11 with radiant heat and a hot air supply part 43 that supplies hot air into the housing part 41. In the present embodiment, the radiation heating part 42 is provided only in the housing part 41a. That is, in the housing part 41a, the temperature of the coating film 11 is rapidly increased by heating the coating film 11 with the radiant heat from the radiation heating part 42 and the convective heat from the hot air supplied into the housing part 41a by the hot air supply part 43. Also, in the housing part 41b, the coating film 11 is heated only with the convective heat from the hot air supplied into the housing part 41a by the hot air supply part 43 without using the radiant heat from the radiation heating part 42, so that the temperature of the coating film 11 is increased to a substantially constant temperature or gently increased to advance the drying of the coating film 11.

[0045] The radiation heating part 42 in the present embodiment is configured to heat the coating film 11 with a laser 44 and has an irradiation part 45 that irradiates the laser 44. The irradiation part 45 is a laser light source that irradiates the coating film 11 with the laser 43. In the present embodiment, two irradiation parts 45 are provided so as to face each other with the base material 1 interposed therebetween in order to irradiate the coating films 11 formed on both surfaces of the base material 1 with the laser 44.

[0046] These irradiation units 45 are each housed in a case unit 51 attached to the upper and lower parts of the housing unit 41a, respectively. An opening 52 through which the laser 44 irradiated from the irradiation unit 45 passes is provided between the case unit 51 and the housing unit 41a. That is, the laser 44 is irradiated vertically downward from the irradiation unit 45 (hereinafter referred to as irradiation unit 45a) housed in the case unit 51 attached to the upper part of the housing unit 41a, and the coating film 11 formed on the surface of the base material 1 is heated. The laser 44 is irradiated vertically upward from the irradiation unit 45 (hereinafter referred to as irradiation unit 45b) housed in the case unit 51 attached to the lower part of the housing unit 41a, and the coating film 11 formed on the back surface of the base material 1 is heated. When there is no particular need to distinguish between the irradiation units 45a and 45b, they are simply referred to as the irradiation unit 45.

[0047] Further, the irradiation unit 45 includes an oscillator (not shown) that irradiates the laser 44 and a lens (not shown) for shaping the laser 44 into a predetermined shape. By irradiating the lens with the laser 44 by the oscillator, the laser 44 shaped into a predetermined shape is irradiated onto the coating film 11. The predetermined shape here refers to a shape that enables the laser 44 to be irradiated over the entire width direction of the coating film 11. Since the base material 1 is conveyed by the conveying device 2 between the lasers 44 irradiated over the width direction of the coating film 11 by the irradiation units 45a and 45b, the entire coating film 11 is uniformly heated. The irradiation and stop of the laser 44 by the irradiation unit 45 are controlled by the above-described control unit.

[0048] The hot air supply unit 43 is for supplying hot air into the housing unit 41. The hot air supply unit 43 includes a nozzle 46 that blows out hot air, an air supply path (not shown) that sends gas to the nozzle 46, and a heater (not shown) that heats the gas in the air supply path. That is, the hot air supply unit 43 heats the gas sent to the nozzle 46 by the air supply path with the heater to make hot air, and supplies the hot air into the housing unit 41 by blowing out the hot air from the nozzle 46. When hot air is supplied into the housing unit 41, the ambient temperature in the housing unit 41 rises, and the coating film 11 is heated.

[0049] Furthermore, the nozzles 46 that blow hot air into the housing 41b consist of a lower nozzle positioned below the base material 1 within the housing 41b to blow hot air onto the back surface of the base material 1, and an upper nozzle positioned above the base material 1 within the housing 41b to blow hot air onto the surface of the base material 1. These lower and upper nozzles are arranged alternately in the direction of transport of the base material 1. As a result, the base material 1 is lifted and floated, and the base material 1 is transported in a substantially linear direction.

[0050] With this configuration, the drying apparatus 4 dries the coating film 11 by heating it and vaporizing the solvent from the coating film 11.

[0051] Furthermore, the drying apparatus 4 in this embodiment is further equipped with a measuring unit 61 for measuring the temperature of the coating film 11. The measuring unit 61 is a radiation thermometer that measures the temperature of the coating film 11 without contact. This measuring unit 61 is located downstream of the irradiation unit 45 within the housing 41a and measures the temperature of the coating film 11 immediately after the laser 44 irradiates it. In this embodiment, two measuring units 61 are provided facing each other on either side of the substrate 1 in order to measure the temperature of each coating film 11 formed on both sides of the substrate 1. The measurement results from the measuring units 61 are then transmitted to the control unit described above.

[0052] Furthermore, the heating mechanism in this embodiment adjusts the total amount of thermal energy applied to a predetermined location on the coating film 11 based on the measurement results from the measurement unit 61. Specifically, the control unit compares the temperature of the coating film 11 measured by the measurement unit 61 with the appropriate temperature of the coating film 11 to determine whether there is an over- or under-heating of the coating film 11. The appropriate temperature of the coating film 11, as used here, refers to the temperature of the coating film 11 when it is heated within a predetermined tolerance range, centered on the ideal temperature of the coating film 11 where there is absolutely no over- or under-heating of the coating film 11.

[0053] If the control unit determines that there is an over- or under-heating of the coating film 11, the heating mechanism adjusts the total amount of thermal energy applied to a predetermined location on the coating film 11 according to the amount of the over- or under-heating. That is, it adjusts the sum of the thermal energy applied by irradiating the coating film 11 with the laser 44 by the irradiation unit 45 and the thermal energy applied by the hot air supplied into the housing unit 41 by the hot air supply unit 43 so that the temperature of the predetermined location on the coating film 11 reaches an appropriate temperature. This makes it possible to heat the coating film 11 to the desired temperature, thus preventing over- or under-heating of the coating film 11. Therefore, it is possible to suppress the formation of uneven drying on the coating film 11.

[0054] Furthermore, the heating mechanism in this embodiment adjusts the thermal energy applied to the coating film 11 by adjusting the irradiation time of the laser 44 to a predetermined location on the coating film 11 by the irradiation unit 45, based on the measurement results from the measurement unit 61.

[0055] In this embodiment, the irradiation unit 45 emits a laser 44 with a pulsed waveform whose duty cycle is controlled. Specifically, as shown in Figures 3(b) and 3(c), the intensity of the laser 44 emitted from the irradiation unit 45 is kept constant, and the ratio of the on-time and off-time of the laser 44 irradiation is controlled so that the laser 44 is continuously emitted at predetermined locations on the coating film 11 at a constant interval. In the example in Figure 3(b), the irradiation time of the laser 44 at predetermined locations on the coating film 11 is adjusted to be 30% shorter than the normal irradiation time shown in Figure 3(a), thereby applying an average of 70% of the thermal energy to the predetermined locations on the coating film 11. In this way, by adjusting the irradiation time of the laser 44 at predetermined locations on the coating film 11, it becomes possible to adjust the thermal energy applied to predetermined locations on the coating film 11 without adjusting the intensity of the laser 44 emitted from the irradiation unit 45.

[0056] When the intensity of the laser 44 irradiated from the irradiation unit 45 is adjusted to control the thermal energy applied to the coating film 11, the penetration depth of the laser 44 into the coating film 11 changes according to the intensity of the laser 44 irradiated from the irradiation unit 45, as shown in Figures 4(a) to 4(c). That is, the penetration depth of the laser 44 into the coating film 11 is shallower when the laser 44 is irradiated at 70% and 30% intensities, as shown in Figures 4(b) and 4(c), compared to when the laser 44 is irradiated at 100% intensity from the irradiation unit 45, as shown in Figure 4(a). As a result, uneven heating occurs in the thickness direction of the coating film 11, and uneven drying is formed in the coating film 11.

[0057] In contrast, the heating mechanism in this embodiment adjusts the time for which the laser 44 is irradiated onto the coating film 11 from the irradiation unit 45 based on the temperature of the coating film 11 measured by the measurement unit 61. This makes it possible to heat the coating film 11 to the desired temperature without adjusting the intensity of the irradiating laser 44. As shown in Figures 3(a) to 3(c), the penetration depth of the laser 44 into the coating film 11 can be kept constant. This suppresses uneven heating in the thickness direction of the coating film 11 that occurs when the intensity of the irradiating laser 44 is adjusted. Therefore, it is possible to further suppress the formation of uneven drying in the coating film 11.

[0058] Furthermore, it is possible to suppress the peeling of the coating film 11 from the substrate 1. Specifically, the coating film 11 inside the housing portion 41a, where the coating film 11 is first heated, contains a large amount of solvent. If the laser 44 is continuously irradiated onto the coating film 11 in this state, a temperature difference is likely to occur between the surface and the interior of the coating film 11, causing the binder contained in the coating film 11 to segregate. As a result, the adhesive strength between the substrate 1 and the coating film 11 weakens, and the coating film 11 peels off from the substrate 1. In contrast, the heating mechanism in this embodiment adjusts the time for which the laser 44 is irradiated onto the coating film 11 from the irradiation unit 45, and deliberately provides a time when the coating film 11 is not irradiated with the laser 44, that is, provides a time for the coating film 11 to cool, thereby reducing the temperature difference between the surface and the interior of the coating film 11. As a result, segregation of the binder contained in the coating film 11 can be suppressed, and thus the peeling of the coating film 11 from the substrate 1 can be suppressed.

[0059] Furthermore, the heating mechanism is configured such that the irradiation time of the laser 44 by the irradiation unit 45 is adjusted so that the time from when the laser 44 is irradiated onto the coating 11 from the irradiation unit 45 until the coating 11 is transported to the housing unit 41b and heated remains constant. By adjusting the irradiation time of the laser 44 by the irradiation unit 45 in this way, differences in the degree of decrease in the surface temperature of the coating 11 during transport from the housing unit 41a to the housing unit 41b are less likely to occur, thereby suppressing uneven heating of the coating 11 in the housing unit 41b.

[0060] Furthermore, the drying apparatus 4 is further equipped with a fracture detection unit (not shown) that detects fracture of the substrate 1. The fracture detection unit is a sensor capable of measuring the tension applied to the substrate 1 by measuring the load applied to the conveyor roll 23 due to the tension of the substrate 1. This fracture detection unit is attached to one of the multiple conveyor rolls 23 and measures the tension applied to the substrate 1 by measuring the load applied to that conveyor roll 23. The measurement result from the fracture detection unit is then transmitted to the control unit, which determines whether or not a fracture has occurred in the substrate 1.

[0061] If the control unit determines that a fracture has occurred in the substrate 1, it immediately stops the irradiation of the laser 44 by the irradiation unit 45. This prevents the laser 44 from irradiating equipment such as the irradiation unit 45 that is located on the opposite side of the substrate 1 from the side of the substrate 1 from which the laser 44 is irradiated, even if the substrate 1 is fractured by the laser 44. Therefore, equipment failure can be prevented.

[0062] Furthermore, the drying apparatus 4 is further equipped with a substrate position detection unit (not shown) that detects misalignment of the substrate 1. The substrate position detection unit is a sensor capable of detecting the position of the edges of the substrate 1 in the width direction. This substrate position detection unit is positioned near each of the ends of the substrate 1 in the width direction and detects the position of each of the ends of the substrate 1 in the width direction. The measurement results from the substrate position detection unit are then transmitted to the control unit, which determines whether or not misalignment has occurred in the substrate 1.

[0063] If the control unit determines that the substrate 1 has shifted position, it immediately stops the irradiation of the laser 44 by the irradiation unit 45. This prevents the laser 44 from irradiating equipment such as the irradiation unit 45 that is located on the opposite side of the substrate 1 from the side of the substrate 1 from which the laser 44 is irradiated. Therefore, equipment failure can be prevented.

[0064] Furthermore, the heating mechanism adjusts the temperature of the hot air supplied from the hot air supply unit 43 into the housing unit 41 based on the temperature of the coating film 11 measured by the measurement unit 61. That is, based on the measurement results from the measurement unit 61, the amount of gas heated by the heater is adjusted, and the temperature-adjusted hot air is supplied from the nozzle 46 into the housing unit 41. This makes it possible to adjust the thermal energy applied to the coating film 11 without adjusting the intensity of the laser 44 irradiated from the irradiation unit 45. Therefore, it is possible to suppress heating unevenness in the thickness direction of the coating film that occurs when adjusting the intensity of the irradiating laser 44, and thus further suppress the formation of drying unevenness in the coating film 11.

[0065] As described above, the drying apparatus 4 in the above embodiment adjusts the total amount of thermal energy applied to predetermined locations on the coating film 11 by the heating mechanism based on the temperature of the coating film 11 measured by the measuring unit 61, thereby enabling the coating film 11 to be heated to a desired temperature. This makes it possible to suppress the formation of uneven drying in the coating film 11.

[0066] Furthermore, by adjusting the time the laser 44 is irradiated onto the coating 11 from the irradiation unit 45 based on the temperature of the coating 11 measured by the measurement unit 61, it becomes possible to heat the coating 11 to the desired temperature without adjusting the intensity of the irradiating laser 44. This suppresses uneven heating in the thickness direction of the coating that occurs when adjusting the intensity of the irradiating laser 44, and thus further suppresses the formation of uneven drying on the coating 11. In addition, in this embodiment, since the laser 44 is irradiated from the irradiation unit 45 with a pulse waveform with a controlled duty cycle, it becomes easier to adjust the thermal energy supplied to the coating 11 than when simply adjusting the on and off times of the laser 44 irradiation.

[0067] [Second Embodiment] Next, a drying apparatus according to the second embodiment of the present invention will be described with reference to Figure 5. The drying apparatus 4 in this embodiment differs from the first embodiment in that the heating mechanism adjusts the irradiation time of the laser 44 to a predetermined location on the coating film 11 by adjusting the arrangement of the blocking section 47. In the following description, specific explanations of points similar to the first embodiment will be omitted, and the differences will be the focus of the description.

[0068] Figure 5 is a diagram illustrating the drying apparatus 4 in this embodiment, and shows a portion of it enlarged. Note that in Figure 5, the coating film 11 formed on the back surface of the substrate 1 and the irradiation unit 45b that irradiates the coating film 11 with the laser 44 are omitted.

[0069] As shown in Figure 5, a blocking section 47 is provided between the substrate 1 and the irradiation section 45 to block the laser 44 irradiated from the irradiation section 45. The blocking section 47 is for blocking the laser 44 irradiated from the irradiation section 45 from irradiating the coating film 11, and in this embodiment, it is made of a material that absorbs the laser 44.

[0070] Furthermore, the blocking section 47 is connected to a moving mechanism (not shown) that moves the blocking section 47 to adjust its position. Based on the measurement results from the measurement section 61, the heating mechanism adjusts the range to which the laser 44 emitted from the irradiation section 45 irradiates the coating film 11 by moving the blocking section 47 using the moving mechanism, thereby adjusting the irradiation time of the laser 44 to a predetermined location on the coating film 11. This makes it possible to adjust the thermal energy applied to a predetermined location on the coating film 11 without adjusting the intensity of the irradiating laser 44. Therefore, it is possible to suppress heating unevenness in the thickness direction of the coating film that occurs when adjusting the intensity of the irradiating laser 44, and thus further suppress the formation of drying unevenness on the coating film 11.

[0071] Furthermore, the blocking section 47 is located upstream of the irradiation section 45 in the transport direction of the substrate 1, and is moved along the transport direction of the substrate 1 by a moving mechanism. This makes it possible to keep the time from when the laser 44 is irradiated onto the coating 11 from the irradiation section 45 in the housing section 41a until the coating 11 is transported to the housing section 41b and heated constant. As a result, differences in the degree of decrease in the surface temperature of the coating 11 between transport from the housing section 41a to the housing section 41b are less likely to occur, and uneven heating of the coating 11 in the housing section 41b can be suppressed.

[0072] [Third Embodiment] Next, the drying apparatus 4 in the third embodiment of the present invention will be described. The drying apparatus 4 in this embodiment differs from the first and second embodiments in that the heating mechanism adjusts the thermal energy applied to a predetermined location on the coating film 11 by adjusting the intensity of the laser 44 irradiated from the irradiation unit 45. In the following description, specific details of points similar to those in the first and second embodiments will be omitted, and the differences will be the focus of the description.

[0073] In this embodiment, the heating mechanism adjusts the thermal energy applied to the coating film 11 by adjusting the intensity of the laser 44 irradiated from the irradiation unit 45 based on the measurement results from the measurement unit 61. As a result, it becomes possible to heat the coating film 11 to a desired temperature, and the formation of uneven drying in the coating film 11 can be suppressed.

[0074] In this embodiment, the intensity of the laser 44 irradiated onto the coating 11 from the irradiation unit 45 is adjusted by using a zoom lens. Specifically, the irradiation unit 45 has a zoom lens (not shown) with variable magnification. By changing the magnification of this zoom lens and irradiating the laser 44 from the oscillator and passing it through the zoom lens, the irradiation range of the laser 44 onto the coating 11 is adjusted, thereby adjusting the density of the laser 44 irradiated onto the coating 11 per unit area. This makes it possible to adjust the intensity of the laser 44 irradiated from the irradiation unit 45.

[0075] [Fourth Embodiment] Next, a drying apparatus 4 in the fourth embodiment of the present invention will be described. The drying apparatus 4 in this embodiment differs from the third embodiment in that the heating mechanism uses an attenuation unit to adjust the intensity of the laser 44 irradiated from the irradiation unit 45. In the following description, specific explanations of points similar to those in the first, second, and third embodiments will be omitted, and the differences will be the focus of the description.

[0076] In this embodiment, an attenuation unit (not shown) is provided between the irradiation unit 45 and the substrate 1 to attenuate the laser 44 irradiated from the irradiation unit 45. This attenuation unit is composed of an attenuator with a variable attenuation amount for the laser 44. By irradiating the laser 44 from the irradiation unit 45 and passing it through the attenuation unit while the attenuation amount of the laser 44 by this attenuation unit is changed, the attenuated laser 44 is irradiated onto the coating film 11. This makes it possible to adjust the intensity of the laser 44 irradiated onto the coating film 11.

[0077] Although embodiments of the present invention have been described in detail above with reference to the drawings, the configurations and combinations thereof in the above embodiments are merely examples, and additions, omissions, substitutions, and other modifications to the configurations are possible without departing from the spirit of the present invention. For example, in the above embodiments, an example was described in which the radiant heating unit 42 heats the coating film 11 with a laser 44, but it is not limited to a laser 44; infrared rays, microwaves, etc., may also be used.

[0078] Furthermore, although the above embodiment describes an example in which the radiant heating unit 42 is provided only in the housing portion 41a, the radiant heating unit 42 may be provided in both the housing portion 41a and the housing portion 41b, or the radiant heating unit 42 may be provided only in the housing portion 41b. In other words, the coating film 11 may be heated by radiant heat not only in the first half or second half of the drying process of the coating film 11.

[0079] Furthermore, in the above embodiment, in order to adjust the total amount of thermal energy applied to a predetermined location on the coating 11, the thermal energy applied by irradiating the coating 11 with a laser 44 by the irradiation unit 45 and the thermal energy applied by supplying hot air into the housing unit 41 by the hot air supply unit 43 are adjusted. However, it is sufficient to adjust the thermal energy applied by either one of these methods.

[0080] Furthermore, although the above embodiment describes an example in which the coating film 11 is formed on both sides of the substrate 1, the coating film 11 may be formed on only one side.

[0081] Furthermore, in the first embodiment described above, an example was described in which the laser 44 is irradiated with a pulse waveform with a controlled duty cycle in order to adjust the irradiation time of the laser 44 to a predetermined location on the film 11. However, it is also possible to simply adjust the time when the laser 44 is on and the time when it is off.

[0082] 100 Coating device 1 Substrate 11 Coating film 2 Conveying device 21 Unwinding roll 22 Winding roll 23 Conveying roll 24 Coating roll 3 Coating mechanism 31 First coating section 32 Second coating section 33 Supply path 34 Manifold 35 Slit 36 ​​Discharge port 37 Tank 4 Drying device 41 Housing section 41a Housing section 41b Housing section 42 Radiation heating section 43 Hot air supply section 44 Laser 45 Irradiation section 46 Nozzle 47 Shut-off section 51 Case section 52 Opening 61 Measurement section

Claims

1. A drying apparatus comprising a heating mechanism including a radiant heating section for heating a coating film formed on a transported substrate with radiant heat, wherein the drying apparatus dries the coating film by heating it with the heating mechanism, and further comprising a measuring section for measuring the temperature of the coating film, wherein the heating mechanism adjusts the total amount of thermal energy applied to a predetermined location on the coating film based on the measurement result from the measuring section.

2. The drying apparatus according to claim 1, wherein the radiant heating unit has an irradiation unit that heats the coating film by irradiating the coating film with a laser, and the heating mechanism adjusts the laser irradiation time of a predetermined location on the coating film by the irradiation unit based on the measurement result by the measurement unit.

3. The drying apparatus according to claim 2, characterized in that the irradiation unit irradiates with a laser in a pulse waveform with a controlled duty cycle.

4. The drying apparatus according to claim 2, wherein a blocking section is provided between the substrate and the irradiation section to block the laser irradiated from the irradiation section, and the heating mechanism adjusts the arrangement of the blocking section based on the measurement results from the measurement section.

5. The drying apparatus according to any one of claims 1 to 4, wherein the heating mechanism includes a housing portion in which a coating film is heated internally, and a hot air supply portion that supplies hot air to the housing portion, and the temperature of the hot air supplied to the housing portion by the hot air supply portion is adjusted based on the measurement results from the measuring portion.

6. The drying apparatus according to any one of claims 2 to 4, further comprising a fracture detection unit for detecting fracture of the substrate, wherein the heating mechanism immediately stops the irradiation of the laser by the irradiation unit when the fracture detection unit detects fracture of the substrate.

7. The drying apparatus according to claim 1, wherein the radiant heating unit has an irradiation unit that heats the coating film by irradiating the coating film with a laser, and the heating mechanism adjusts the intensity of the laser irradiated by the irradiation unit based on the measurement results from the measurement unit.

8. The drying apparatus according to claim 7, characterized in that the irradiation unit has a zoom lens with variable magnification, and the irradiation range of the laser is adjusted by changing the magnification of the zoom lens.

9. The drying apparatus according to claim 7, wherein a damping section is provided between the substrate and the irradiation section to dampen the laser irradiated from the irradiation section, and the damping section is formed so that the amount of laser damping can be adjusted.

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