JP6609117B2 - Recording device - Google Patents

Description

  The present invention relates to a sheet heating technique.

  As one application of a heating apparatus for heating a sheet, for example, application to a recording apparatus is known. In an ink jet recording apparatus, a technique for heating a sheet such as paper to promote ink drying is known. However, the heating apparatus may have high power consumption. Therefore, it has been proposed to set a mode for shifting to a lower temperature after satisfying a condition that there is no print job for a certain period of time (Patent Document 1). Such a state may be called as a power saving mode or a sleep mode, for example.

Japanese Patent No. 2590822

  In a recording apparatus including a conveyance mechanism that nipping and conveying a sheet, conveyance may be stopped while the sheet is nipped in the power saving mode. When the sheet expanded during heating contracts as the temperature decreases, distortion may occur in the sandwiched portion of the sheet, and the sheet may be wrinkled. This wrinkle is a cause of sheet quality degradation and device malfunction.

  The present invention provides a technique for preventing wrinkles from occurring on a sheet.

According to the present invention, for example, a conveyance unit that sandwiches a sheet and conveys the sheet in the conveyance direction, a recording head that is provided downstream of the conveyance unit in the conveyance direction and discharges ink onto the sheet, and faces the recording head And a supporting unit that supports the sheet, a heating unit that heats the sheet from the lower side of the supporting unit , and a release that partially releases the holding of the sheet by the conveying unit before the heat generation of the heating unit is reduced. e Bei means, wherein the conveying means includes a conveying roller, and a plurality of pinch rollers that are pressed against the conveying roller, wherein the release means includes pressing a portion of the pinch roller of said plurality of pinch rollers A recording apparatus is provided , which is movable between the position and the pressure release position .

  ADVANTAGE OF THE INVENTION According to this invention, the technique which prevents that a wrinkle generate | occur | produces on a sheet | seat can be provided.

1 is a schematic diagram of a recording apparatus according to an embodiment of the present invention. (A) And (B) is explanatory drawing of a control example. Explanatory drawing of a control example. Explanatory drawing of a control example. (A) And (B) is explanatory drawing which shows the clamping cancellation | release example. (A) And (B) is a flowchart which shows the example of control. (A) And (B) is a flowchart which shows the example of control. The flowchart which shows the example of control. FIG. 6 is a schematic diagram of another example of a recording apparatus. FIG. 6 is a schematic diagram of another example of a recording apparatus. FIG. 6 is a schematic diagram of another example of a recording apparatus. (A)-(C) is explanatory drawing which shows the example of control. (A) And (B) is explanatory drawing which shows the example of control. (A) And (B) is a flowchart which shows the example of control.

  Hereinafter, an example in which the present invention is applied to a recording apparatus will be described. However, the present invention is not limited to a recording apparatus, and can be applied to apparatuses for various uses for handling sheets.

<First embodiment>
FIG. 1 is a schematic diagram of a recording apparatus A. The recording apparatus A is an ink jet recording apparatus that records an image on a sheet S as a recording medium. In “recording”, not only when significant information such as characters and figures is formed, but also regardless of significance, images, patterns, patterns, etc. are widely formed on the recording medium, or the medium is processed. It does not matter whether or not it is manifested so that humans can perceive it visually. In addition to paper, the recording medium may be cloth, plastic film, or the like. The present invention can also be applied to other types of recording apparatuses.

  The recording apparatus A includes a supply unit 2, a transport unit 3, and a discharge unit 9 as a mechanism for transporting the sheet S in the transport direction F. The conveyance direction F may be referred to as a sub-scanning direction, and the direction orthogonal to the conveyance direction F may be referred to as a main scanning direction. Further, the supply unit 2 side may be referred to as the upstream side, and the discharge unit 9 side may be referred to as the downstream side.

  The supply unit 2, the transport unit 3, and the discharge unit 9 transport the sheet S on the support unit 4. The support unit 4 is provided from the supply unit 2 to the discharge unit 9 and forms a conveyance path (conveying surface) of the sheet S. The sheet S is conveyed while being supported on the support portion.

  The supply unit 2 supports an unrecorded sheet roll 1. The sheet S is a web-like continuous sheet, and is provided in the supply unit 2 in the form of a sheet roll 1. The sheet S can employ various sizes with a sheet width ranging from several centimeters to several meters, for example. The supply unit 2 supports the sheet roll 1 rotatably. The supply unit 2 includes a drive mechanism that adjusts the tension of the sheet S pulled out from the sheet roll 1. This drive mechanism is, for example, a mechanism that rotationally drives the sheet roll 1 using a motor as a drive source, and adjusts the tension of the sheet S by feeding and winding the sheet S. In addition to this, the supply unit 2 may include a pair of rollers (a driving roller and a driven roller) that sandwich and convey the sheet S.

  The conveyance unit 3 is disposed on the downstream side of the supply unit 2 and conveys the sheet S while sandwiching it. The transport unit 3 includes a transport roller 3a extending in the main scanning direction, and a pinch roller 3b pressed against the transport roller 3a. The conveyance roller 3a and the pinch roller 3b extend over a length corresponding to the maximum width of the sheet S assumed to be used.

  The transport unit 3 includes a drive mechanism using a motor as a drive source, and the drive mechanism rotationally drives the transport roller 3a. The transport unit 3 also includes a sensor (for example, a rotary encoder) that detects the rotation amount of the transport roller 3a. The conveyance amount of the sheet S can be controlled based on the detection result of this sensor.

  In the present embodiment, a plurality of pinch rollers 3b are provided in the main scanning direction, but one pinch roller 3b may be provided. The pinch roller 3b forms a nip portion with the transport roller 3a and rotates following the rotation of the transport roller 3a. The sheet S is nipped and conveyed by the nip portion.

  The release unit 6 is a unit that can at least partially release the holding of the sheet S by the transport unit 3. In the case of this embodiment, the release unit 6 can move at least a part of the plurality of pinch rollers 3b between the pressure contact position (solid line position in FIG. 1) and the pressure release position (dashed line position in FIG. 1). is there. The pressure contact position is a position where the pinch roller 3b presses against the conveying roller 3a to sandwich the sheet S, and is a position indicated by a solid line in FIG. The pressure release position is a position where the pinch roller 3b is separated from the conveying roller 3a and releases the nipping of the sheet S, and is a position indicated by a broken line in FIG. In the present embodiment, the release unit 6 moves only a part of the pinch rollers 3b, but may move all the pinch rollers 3b.

  The release unit 6 includes, for example, a movable member that supports the pinch roller 3b, an elastic member (for example, a coil spring) that urges the movable member so that the pinch roller 3b presses against the transport roller 3a, and an actuator. The actuator is, for example, an electromagnetic solenoid or a motor, and biases the movable member so that the pinch roller 3b is separated from the transport roller 3a against the bias of the elastic member during operation. The movable member is slidably or rotatably provided so that the pinch roller 3b can be moved.

  The discharge unit 9 is disposed on the downstream side of the transport unit 3 and discharges the sheet S after recording. The discharge unit 9 includes a discharge roller 9, and the sheet S is conveyed by the rotation of the discharge roller 9. The sheet S is discharged out of the apparatus while falling downward. The discharge unit 9 includes a drive mechanism using a motor as a drive source, and this drive mechanism rotationally drives the discharge roller 9a. A cutter unit for cutting the sheet S may be provided on the downstream side of the discharge unit 9.

  The recording apparatus A includes a recording unit 7 that records an image on the sheet S conveyed by the conveyance unit 3. A region of the support unit 4 that faces the recording unit 7 constitutes a platen. The recording unit 7 includes a carriage 5 and a recording head 10 mounted on the carriage 5. The carriage 5 may be equipped with an ink reservoir that stores ink ejected from the recording head 10.

  The carriage 5 is reciprocated in the main scanning direction by a driving mechanism (not shown). The drive mechanism includes, for example, a drive source such as a motor, a transmission mechanism that transmits the drive force of the drive source to the carriage 5, a guide shaft that guides the movement of the carriage 5, and the like. The transmission mechanism is, for example, a belt transmission mechanism. Further, a position detection mechanism (not shown) for detecting the position of the carriage 5 that reciprocates is provided. The position detection mechanism includes, for example, a linear scale that extends in the main scanning direction, and an encoder sensor that is mounted on the carriage 5 and reads the linear scale. The position detection mechanism can control the position of the carriage 5, that is, control of the ink discharge position with respect to the sheet S.

  The recording head 10 may be any of a method using a heater, a method using a piezo element, a method using an electrostatic element, and a method using a MEMS element. In the present embodiment, a recording head using emulsion ink (dispersed ink) is assumed, but the present invention is not limited to this.

  The emulsion ink is solidified and fixed on the surface of the sheet S by forming a film by applying heat to the ink droplets discharged and landed on the sheet S. In order to promote this fixing, a heating unit 100 is provided. The heating unit 100 is a unit that heats the sheet S, and is disposed below the conveying surface of the sheet S formed by the support unit 4.

  In the case of this embodiment, the heating unit 100 includes a plurality of heater units 101 to 104 that can be controlled independently. Each heater unit 101-104 includes a heat source. The heat source is, for example, a device that converts electric power into heat. Here, the amount of heat generated can be controlled by the amount of electric power supplied. The heating range of each of the heater units 101 to 104 is set to a width corresponding to the maximum recording width of the sheet S in the main scanning direction. The heater units 101 to 104 are arranged side by side in the transport direction F.

  Each of the heater units 101 to 104 heats the sheet S through the support portion 4. In other words, the sheet S in contact with the support part 4 is heated by heating the support part 4. The support portion 4 may be provided for each of the heater units 101 to 104, or may be a wall body that constitutes a part of each of the heater units 101 to 104. In addition, each heater unit 101-104 may heat the sheet | seat S by non-contact with radiant heat, warm air, etc. When heating in such a non-contact manner, the support 4 is heated to the same temperature through the sheet S.

  Of the heater units 101 to 104, the heater unit 102 is a main heater and is disposed at a position facing the recording unit 7 (a position below the platen). The heater unit 102 may be referred to as a platen heater 102. The heater unit 101 is an auxiliary heater that preheats the sheet S before image recording, and is disposed on the upstream side of the platen heater 102. The heater unit 101 may be referred to as an auxiliary heater 101 or a preheater 101. The heater unit 103 is an auxiliary heater that further promotes drying of ink after recording, and is disposed on the downstream side of the platen heater 102. The heater unit 103 may be referred to as an auxiliary heater 103 or an after heater 103. The heater unit 100 is a heater that is supplementarily provided as necessary. In the present embodiment, the heater unit 100 is disposed on the upstream side of the preheater 101. The number and arrangement of the heater units are not limited to this, and various numbers and arrangements can be adopted.

  In the case of the present embodiment, the platen heater 102 is a main heat source in the heating apparatus 100, and is a heater unit that has the slowest temperature decrease in a stopped state. Factors that cause the slowest decrease in temperature include, for example, a structure that generates the largest amount of heat, a structure that controls the amount of generated heat to be the largest, and a structure that has the largest amount of heat storage. Or there can be mentioned that there is another heater unit in the vicinity.

  The heating temperature of the sheet S is required to be equal to or higher than a predetermined temperature for drying the ink. On the other hand, if the temperature is too high, so-called thermal damage may occur. Therefore, it can be controlled to be stable within a predetermined temperature range. Examples of the thermal damage include recording failure, thermal deformation of the sheet S, bubbles, and bleeding of adhesive. The predetermined temperature differs depending on the type of the sheet S. For example, if the sheet S is an adhesive vinyl chloride material sheet, the temperature range is, for example, 30 ° C. to 110 ° C., and in a narrower range, 40 ° C. to It is 90 ° C., and in a narrower range, it is 50 ° C. to 80 ° C.

  Various factors that cause the temperature to change (hereinafter referred to as temperature fluctuation factors) act on the platen heater 102. For example, the amount of ink applied to the sheet S by the recording unit 7 can be mentioned. This is because the amount of heat taken from the platen heater 102 by the so-called vaporization heat through the sheet S when the ink component dries varies depending on the amount of ink applied.

  Examples of other temperature fluctuation factors include various factors such as the conveyance speed of the sheet S and the temperature of the supplied ink. In order to maintain the sheet S within a predetermined temperature range even when these temperature fluctuation factors act, a member constituting the support portion 4 heated by the platen heater 102 is set to a material having a high thermal conductivity and a large heat storage amount. be able to. For example, a metal material such as aluminum or copper can be used. Specifically, an aluminum plate having a thickness of 5 to 10 mm can be employed, but is not limited thereto.

  The recording apparatus A includes a temperature sensor 13. The temperature sensor 13 is a sensor that detects the temperature in the heating region of the platen heater 102, and detects the temperature of the sheet S on the platen heater 102, as indicated by a broken line. As the temperature sensor 13, for example, an infrared temperature sensor that detects the surface temperature of the sheet S in a non-contact manner, a contact temperature sensor that detects the temperature by contacting the sheet S, and the like can be considered. In this embodiment, the temperature detection target is the heating area of the platen heater 102. However, a temperature sensor corresponding to each of the heater units 101 to 104 may be provided to detect the temperature in each heating area individually. Good. Of course, if the number of sensors is small, the cost can be reduced accordingly.

  The recording apparatus A includes an adsorption unit 8 that adsorbs the sheet S to the support unit 4. Examples of the adsorption method include a method in which air holes are provided in the support portion 4 and air is sucked from the air holes to adsorb the sheet S to the surface of the support portion 4. In this case, the adsorption unit 8 includes a negative pressure generation source such as a pump for sucking air. Further, as an adsorption method, for example, a method in which the sheet S is adsorbed on the surface of the support portion 4 by electrostatic force can be cited. In this case, the suction unit 8 includes an electric circuit that generates static electricity on the surface of the support portion 4.

  For example, interference between the sheet S and the recording head 10 is prevented by bringing the sheet S and the support portion 4 into close contact with each other by the suction unit 8. Moreover, the thermal conductivity to the sheet S is improved, and the sheet S can be heated to a more stable temperature. The attracting force acts on the sheet S in a direction perpendicular to the surface of the support portion 4, so that the restraining force is relatively weak with respect to the transport direction F. For this reason, the conveying operation of the sheet S is possible even during the adsorption, and the expansion and contraction of the sheet S due to heat may occur.

  The recording apparatus A includes a control unit 14. The control unit 14 is an electronic circuit that controls various devices included in the recording apparatus A based on detection results of various sensors included in the recording apparatus A. For example, the control unit 14 controls the output of the heating unit 100 based on the detection result of the temperature sensor 13. The control unit 14 controls the output of the heating unit 100 including stopping (OFF). The output here is, for example, the heat generated by the heating unit 100. The control unit 14 also controls the pinch roller 3 b to be held and released by the release unit 6 and the suction state of the suction unit 8.

  The control unit 14 includes, for example, a CPU, a storage device, and an interface. The CPU executes the control program stored in the storage device and controls the recording apparatus A. The storage device is, for example, a RAM or a ROM. The interface enables transmission or reception of signals between the CPU and various sensors and various devices. The control unit 14 also includes a circuit that processes a signal from the sensor, a drive circuit that drives the device, and the like.

  An example of the recording operation of the recording apparatus A will be described. In recording an image on the sheet S, a two-dimensional ink image is formed on the sheet S by alternately repeating movement of the recording head 10 in the main scanning direction and ink ejection and conveyance of the sheet S in the sub scanning direction. (Serial recording). During serial recording, the sheet S is adsorbed on the support unit 4 by the adsorption unit 8. In the serial recording, a so-called multi-pass recording method can be adopted in which the carriage 5 is reciprocally moved to apply the ink to the same portion of the sheet S in a plurality of times (overprinting) to complete the image.

  The number of overstrikes is also referred to as the number of passes. For example, a recording method that performs eight overstrikes is referred to as “8-pass recording”. When emulsion ink is used, a portion where ink is applied from the recording head 10 in a certain main scan (pass) is somewhat dried until ink is applied to the same portion in the next main scan (pass). Need to be. If the ink is not dried to some extent at the time of the next main scanning, the overstrike inks are mixed together, causing image deterioration due to bleeding or aggregation. Therefore, the heating unit 100 can heat the sheet S to a stable temperature that does not fall below a predetermined temperature range.

<Control of heating unit>
A control example of the heating unit 100 will be described. When the sheet S is heated to a predetermined temperature (for example, 60 ° C.) by the platen heater 102, the temperature of the recording position is detected by the temperature sensor 13, and the platen heater 102 is feedback-controlled so that the temperature of the sheet S becomes 60 ° C. Is done. As a specific control method, for example, PID control is conceivable, but not limited thereto. In this way, a sheet on which an image is formed on the sheet S and has been dried and fixed can be obtained.

  As an operation mode of the recording apparatus A, a recording standby mode and a power saving mode can be set in addition to a recording mode for performing a recording operation. The recording standby mode can be set as a stage before shifting to the power saving mode after the recording operation is completed. The recording standby mode is a mode in which standby is performed while maintaining a temperature or the like so that the next recording job can be started immediately. In the recording standby mode, the heating unit 100, the suction unit 8 and the like operate in the same manner as during recording. The conveyance of the sheet S is stopped.

  Transition to the power saving mode can be made when a predetermined condition, for example, the passage of a predetermined time, is satisfied for the purpose of reducing power consumption and preventing noise after the recording operation is completed. In this power saving mode, processing such as stopping the conveyance of the sheet S, stopping the operation of the platen heater 102 and the suction unit 8, or changing the heating temperature and the suction force to a lower state is performed. In the present embodiment, the power saving mode is a mode in which the power consumption of the heating unit 100 is lower than that in the recording mode or the recording standby mode. The power saving mode may finally be a state in which little power is consumed (main body power supply OFF, so-called sleep mode).

  Here, when shifting to the power saving mode, the sheet S is in a state where at least a part thereof is present in the conveyance path. For this reason, a difference occurs in the temperature distribution of the sheet S, which may cause wrinkles. Hereinafter, a control example for suppressing wrinkles and unevenness when shifting to the power saving mode will be described. Here, the control for setting the preheater 101, the platen heater 102, and the afterheater 103 to the power saving state will be mainly described.

<Control example 1>
2A is an explanatory diagram of the control example 1, and FIG. 6A is a flowchart illustrating a processing example executed by the control unit 14. FIG.

  In the graph of FIG. 2A, the vertical axis indicates the temperature of the sheet S, and the horizontal axis indicates the elapsed time. Curves L101 to L103 indicate the temperatures of the sheets S in the preheater 101, the platen heater 102, and the afterheater 103, respectively. In FIG. 1, the temperature of the sheet S in the preheater 101 is the temperature of the portion of the sheet S located in the region RG1. In FIG. 1, the temperature of the sheet S in the platen heater 102 is the temperature of the portion of the sheet S located in the region RG2. In FIG. 1, the temperature of the sheet S in the after heater 103 is the temperature of the portion of the sheet S located in the region RG3. Among these temperatures, the temperature of the sheet S in the region RG2 can be detected by the temperature sensor 13. In the present embodiment, the temperatures of the sheets S in the other regions RG1 and RG3 are estimated temperatures.

  As already described, the platen heater 102 is a main heat source in the heating device 100, and is a heater unit that has the slowest temperature drop in a stopped state. In the case of this example, it is assumed that the heat storage amount of the platen heater 102 is set to be the largest.

  As an example, the following temperature situation is assumed. The ambient temperature is 25 ° C. The environmental temperature is, for example, the room temperature of the space where the recording apparatus A is installed. The temperature settings of the regions RG1 to RG3 of the sheet S during the recording indicated by the times P0 to P1 or in the recording standby mode are, for example, 50 ° C., 60 ° C., and 65 ° C., respectively.

  The preheater 101 and the afterheater 103 are adjacent to the platen heater 102. For this reason, in the recording or recording standby mode, each heater is controlled such that the temperature difference of the sheet S between adjacent heaters (in other words, between the regions RG) is within the allowable temperature range Z. The allowable temperature range Z is a temperature range in which wrinkles and irregularities do not occur, and is, for example, a range within ± 10 ° C. when the sheet S is adhesive vinyl chloride.

  In FIG. 2A, the allowable temperature range Z centering on the temperature of the sheet S in the region RG2 is indicated by hatching. Hereinafter, for convenience of explanation, ½ of the width of the allowable temperature range Z is defined as the temperature z. For example, in the case of the aforementioned adhesive vinyl chloride, z = 10 ° C.

  At times P0 to P1 (step S101 in FIG. 6A), the recording apparatus A is in the recording or recording standby mode. Mode transition control for shifting to the power saving mode is executed in the determination in step S102 of FIG. At time P1 in FIG. 2A (step S103 in FIG. 6A), the heating of the platen heater 102 is stopped by the control unit 14 (curve L102 in FIG. 2A), and a power saving state is set. In the present embodiment, in this way, in the power saving state, the power supply for heat generation to the platen heater 102 is turned off and the heat generation stop state is set. However, in the power saving state, only the heat generation may be reduced.

  In this way, the platen heater 102 having the largest heat storage amount, that is, the slowest temperature drop due to heat dissipation is first stopped. At this time, the pre-heater 101 and the after-heater 103 are continuing the same heating as before (curves L101 and L103 in FIG. 2A). This is because the pre-heater 101 and the after-heater 103 have a faster temperature drop after stopping the heater than the platen heater 102. That is, if all the heaters are stopped at the same time, the temperature may be relatively high in the region RG2, relatively low in the regions RG1 and RG3, and the temperature difference may be large. As in this embodiment, by stopping the pre-heater 101 and the after-heater 103 after stopping the platen heater 102, the temperature difference on the sheet S can be reduced and wrinkles are prevented from occurring on the sheet S. can do.

  Next, the timing when the preheater 101 and the afterheater 103 are set in the power saving state will be described. In the power saving state of the pre-heater 101 and the after-heater 103, in the case of this embodiment, the power supply for heat generation is turned off, but the heat generation may be reduced.

  As shown by a curve L102, the temperature of the sheet S in the region RG2 corresponding to the platen heater 102 gradually decreases due to heat radiation after the time P1. The other heaters (see curves L101 and L103) are stopped so that the temperature of the sheet S changes within the allowable temperature range Z. Here, after heater 103 is stopped at time P2, and preheater 101 is stopped at time P3.

  As already described, the present embodiment does not have a sensor for detecting the temperature of the sheet S in the region RG1 and the region RG3. The stop timing of the pre-heater 101 and the after-heater 103 may be determined based on the temperature of the region RG2 detected by the temperature sensor 13. Alternatively, it may be determined by the elapsed time from the stop of the platen heater 102.

  The stop timing may be determined from the characteristics of the device grasped in advance, or may be determined according to the environmental temperature in addition to the characteristics of the device. A sensor for detecting the environmental temperature may be provided, or the user may input the environmental temperature.

  By grasping the temperature lowering characteristics of the apparatus in advance, it is possible to specify the temperature at which the heater that is continuously heating should be stopped so that the temperature of each part of the sheet S changes within the allowable temperature range Z. For example, the temporal relationship between the temperature change in the region RG2 and the temperature change in the regions RG1 and RG2 can be obtained in advance by simulation or experiment. Then, the preheater 101 and the afterheater 103 can be stopped at the timing when the temperature of the region RG2 detected by the temperature sensor 13 reaches the threshold temperature. For example, here, the temperature of the region RG2 where the preheater 101 can be stopped is T1, and the temperature of the region RG2 where the afterheater 103 can be stopped is T2. Then, if the detection result of the temperature sensor 13 is monitored, the arrival of the stop timing of the pre-heater 101 and the after-heater 103 can be determined.

  Further, after the platen heater 102 is stopped, if the time until the temperature of the region RG2 reaches T1 is a substantially constant time, the preheater 101 is stopped after a predetermined time without using the detection result of the temperature sensor 13. You can also Similarly, after the platen heater 102 is stopped, if the time for the temperature of the region RG2 to reach T2 is a substantially constant time, the detection result of the temperature sensor 13 is not used, and the after heater 103 is used after a predetermined time has elapsed. Can also be stopped. When managing by time, it will be necessary to set the time to stop in consideration of the influence of environmental temperature.

  The control example in FIG. 6A shows a case where the stop timing of the preheater 101 and the afterheater 103 is determined based on the detection result of the temperature sensor 13.

  In step S104, the temperature of the region RG2 of the sheet S detected by the temperature sensor 13 is determined. Here, if it is determined that the temperature of region RG2 is equal to or lower than T1, preheater 101 is stopped in step S105 (see time P3 in FIG. 2A). If it is determined that the temperature of the region RG2 is equal to or lower than T2, the after heater 103 is stopped in step S106 (see time P2 in FIG. 2A). If it is determined that the temperature of the region RG2 is equal to or lower than T1 and T2, both the pre-heater 101 and the after-heater 103 are stopped in step S107. Thereafter, one unit of processing is completed. When the temperature of the region RG2 is higher than T2, the process is waiting.

  When the preheater 101 or the afterheater 103 is stopped, the temperature of the sheet S in the corresponding regions RG1 and RG3 gradually decreases, but changes within the allowable temperature range Z described above.

  In step S108 of FIG. 6A, it is confirmed whether both the pre-heater 101 and the after-heater 103 are stopped. If not stopped, the process returns to S104, and if stopped, one unit of processing is terminated. .

  When all of the plurality of heater units 101 to 103 are stopped in this way, the main body power supply can be turned off or the sleep mode can be shifted. Since the heater is stopped by shifting the stop timing in this way, the temperature difference of the sheet S can be maintained within the allowable temperature range. Therefore, wrinkles and unevenness can be suppressed. In addition, since it is not necessary to perform complicated control of the heater, the configuration can be simplified.

  In the present embodiment, the stop timing of the other heaters is set so that the temperature distribution of the sheet S is within the allowable temperature range in accordance with the temperature decrease due to the heat radiation of the platen heater 102. But you can do the same. For example, when the heater unit 104 is located at a position adjacent to the preheater 101 as in the present embodiment, the heater unit 104 may be stopped in accordance with a temperature drop due to heat dissipation of the preheater 101.

<Control example 2>
After the platen heater 102 is put into the power saving state, before the preheater 101 and the after heater 103 are put into the power saving state, the heat generation of the preheater 101 and the after heater 103 may be controlled based on the detection result of the temperature sensor 13. FIG. 2B is an explanatory diagram of the control example 2, and FIG. 6B is a flowchart illustrating a process example executed by the control unit 14.

  Times P0 to P1 in FIG. 2B are during recording or recording standby (step S201 in FIG. 6B). The mode shift control for shifting to the power saving mode is executed in the determination in step S202 of FIG. At time P1, the platen heater 102 having the largest amount of heat storage, that is, the slowest temperature drop due to heat dissipation is stopped in step S203 of FIG. As indicated by a curve L102, the temperature of the sheet S in the region RG2 corresponding to the platen heater 102 gradually decreases due to heat radiation after the time P1. After the time P1, the preheater 101 and the afterheater 103 shift from the setting for setting the respective fixed temperatures during the time P0 to P1 to the temperature control based on the temperature of the sheet S in the region RG2 detected by the temperature sensor 13 (FIG. 6 (B), step S204). The temperature control is PID control in which the detected temperature of the temperature sensor 13 is a target value, for example.

  In this temperature control, the preheater 101 or the afterheater 103 can be stopped before the temperature of the sheet S in the region RG2 drops to the environmental temperature. That is, after the pre-heater 101 or the after-heater 103 is stopped, the temperature of the sheet S in the region RG1 or RG3 may be stopped at a timing that is within the allowable temperature range Z with respect to the temperature of the sheet S in the region RG2. .

  In the example of FIG. 6B, in step S205, it is determined whether or not the temperature of the sheet S in the region RG2 is equal to or lower than the environmental temperature + z. If applicable, the process proceeds to S206, and if not applicable, the process waits. In step S206, the preheater 101 and the afterheater 103 are stopped.

  When all of the plurality of heater units 101 to 103 are stopped in this way, the main body power supply can be turned off or the sleep mode can be shifted. Since the heater is stopped by shifting the stop timing in this way, the temperature difference of the sheet S can be maintained within the allowable temperature range. Therefore, wrinkles and unevenness can be suppressed. In addition, since it is not necessary to perform complicated control of the heater, the configuration can be simplified.

  Further, by performing the temperature control described above, it is possible to deal with a narrower allowable temperature range Z as compared with Control Example 1, and it is possible to obtain a high-quality sheet S free from wrinkles and unevenness.

  In this embodiment, the other heaters are temperature-controlled so that the temperature distribution of the sheet S is within the allowable temperature range in accordance with the temperature drop due to the heat radiation of the platen heater 102, but the same applies to other adjacent heaters. You can do it. For example, when the heater unit 104 is located at a position adjacent to the preheater 101 as in the present embodiment, the heater unit 104 may be temperature controlled in accordance with a temperature drop due to heat dissipation of the preheater 101.

<Control example 3>
A control example 3 will be described with reference to FIGS. 3 and 7A. Control example 3 can be combined with any of control examples 1 and 2 described above. By combining these, further wrinkle and unevenness suppression effects can be expected. Here, the case of combining with control example 2 will be described as an example, but the combination with control example 1 is also possible.

  In this example, the suction operation control of the suction unit 8 will be described. In FIG. 3, the content of the graph showing the allowable temperature range Z shown on the upper side is the same as FIG. The graph shown on the lower side of FIG. 3 is a timing chart showing the operation of the suction unit 8 with the elapsed time on the horizontal axis and the operation content on the vertical axis.

  During the recording from time P0 to P1 or in the recording standby mode (step S301 in FIG. 7A), the suction unit 8 is in a state where the sheet S is sucked to the support portion 4. The mode shift control for shifting to the power saving mode is executed by the determination in step S302 of FIG. In step S303 in FIG. 7A, the platen heater 102 is stopped (time P1 in FIG. 3). Similar to Control Example 2, the pre-heater 101 and the after-heater 103 shift from the setting for setting the fixed temperature as a target in Step S304 to the temperature control within the allowable temperature range Z centering on the temperature of the sheet S in the region RG2. At this time, the suction state of the suction unit 8 is maintained as shown in step S305 of FIG.

  The adsorption of the adsorption unit 8 is maintained until a predetermined condition is satisfied. Here, it is a condition that the temperature of the sheet S has decreased to a predetermined temperature. In step S306 in FIG. 7A, it is determined whether or not the temperature of the sheet S in the region RG2 has decreased to around the environmental temperature (25 ° C.). The temperature of the sheet S in the region RG2 is a temperature detected by the temperature sensor 13. If applicable, the process proceeds to S307, and if not applicable, the process waits. In step S307 of FIG. 7A, the adsorption of the adsorption unit 8 is stopped, and the preheater 101 and the after heater 103 are stopped (see time P4 in FIG. 3). After time P4, the main unit power can be turned off or the mode can be shifted to the sleep mode.

  In this example, by controlling the suction unit 8 based on the operating state of the heating unit 100, the suction unit 8 can be used to prevent the occurrence of wrinkles due to the temperature difference of the sheet S. That is, since the adsorption of the sheet S is continued in the process of decreasing the temperature of the sheet S, the heat transfer of the platen heater 102 via the support portion 4 is continued. As a result, the temperature of the sheet S is stabilized and uniform, and wrinkles and unevenness due to temperature changes can be suppressed. Further, since the sheet S is held in a posture following the support portion 4 by suction, the flatness thereof is maintained. As a result, wrinkles and unevenness can be suppressed. Further, in the present embodiment, since the sheet S is sucked by the negative suction pressure, the effect of air cooling of the platen heater 102 can be expected. Therefore, the recording apparatus A can be stopped in a shorter time compared to the case where no suction is performed. Thereby, a high-quality sheet free from wrinkles and irregularities can be obtained.

  FIG. 7B shows a modification of the flowchart of FIG. In the example of FIG. 7B, step S306 in the example of FIG. 7A is changed as step S406, and the other processes are the same. In step S406 in FIG. 7B, it is determined whether or not the temperature of the sheet S in the region RG2 is equal to or lower than the environmental temperature + z. The temperature of the sheet S in the region RG2 is a temperature detected by the temperature sensor 13. If applicable, the process proceeds to S307, and if not applicable, the process waits.

  In the case of this example, the adsorption of the adsorption unit 8 is stopped before the time P4 in FIG. 3, and the preheater 101 and the after heater 103 are stopped. Compared to the example of FIG. 7A, the main unit power can be turned off or the sleep mode can be shifted.

  If the control example 3 is not performed, the suction unit 8 can be omitted from the configuration of the recording apparatus A.

<Control example 4>
A control example 4 will be described with reference to FIGS. 4, 5A and 5B, and FIG. Control example 4 can be any combination with control examples 1 to 3 described above. By combining these, further wrinkle and unevenness suppression effects can be expected. Here, the case of combining with control example 1 will be described as an example, but the combination with control example 2 and control example 3 is also possible.

  In this example, the release operation control of the release unit 6 will be described. In FIG. 4, the content of the graph showing the allowable temperature range Z shown on the upper side is the same as FIG. The graph shown on the lower side of FIG. 4 is a timing chart showing the operation of the release unit 6 with the elapsed time on the horizontal axis and the operation content on the vertical axis.

  During the recording from time P0 to P1 or in the recording standby mode (step S501 in FIG. 8), the pinch roller 3b holds the sheet S. The mode shift control for shifting to the power saving mode is executed in the determination in step S502 of FIG. At time P1 in FIG. 4 (step S503 in FIG. 8), the platen heater 102 is stopped, and at least a part of the pinch rollers 3b is moved to the pressure release position by the release unit 6. As a result, the holding of the sheet S between the conveying roller 3a and the plurality of pinch rollers 3b is at least partially released.

  The pinch roller 3b that moves to the pressure release position may be, for example, pinch rollers 3b on both sides of the pinch roller 3b 'except for the substantially central pinch roller 3b' as shown in FIG. Further, as shown in FIG. 5B, a pinch roller 3b excluding the pinch roller 3b 'at one end may be used. The release unit 6 may be provided only on the pinch roller 3b that is moved to the pressure release position.

  Here, although all the pinch rollers 3b may be moved to the pressure release position, the holding of the sheet S is completely released. Then, the position of the sheet S may move due to the action of the weight of the sheet S or an unexpected operation. In particular, when the sheet S is not sucked by the suction unit 8 or the suction unit 8 is not provided, the position of the sheet S may move. Even if the sheet S is adsorbed, the restraining force is relatively weak against movement in the transport direction F as described above. When importance is attached to the positional stability of the sheet S, as shown in FIGS. 5A and 5B, a part of the pinch rollers 3b is maintained in the pressure contact position, and the conveying roller 3a and a part of the pinch rollers are maintained. Clamping of the sheet S with 3b can be continued.

  Steps S504 to S508 in FIG. 8 are the same as steps S104 to S108 in FIG. If the heater is stopped in step S507 or step S508 in FIG. 8, it is possible to turn off the main body power or shift to the sleep mode in a state where the clamping of the sheet S is partially released.

  In this example, by controlling the release unit 6 based on the operating state of the heating unit 100, the release unit 6 can be used to prevent the occurrence of wrinkles due to the temperature difference of the sheet S. That is, in the process of lowering the temperature of the sheet S, the holding of the sheet S by the transport unit 3 is at least partially released, so that the distortion due to the expansion and contraction of the sheet S due to heat is released. The sheet S can easily move with respect to the support portion 4 in the portion where the clamping is released, and the occurrence of distortion is suppressed. For this reason, wrinkles and unevenness can be suppressed. Furthermore, the same effect can be expected in the process of increasing the temperature. In other words, the distortion caused by thermal contraction or thermal expansion of the sheet S due to temperature change is released by at least partially releasing the holding of the sheet S by the transport unit 3, and wrinkles and unevenness due to thermal contraction due to the temperature change of the sheet S are suppressed. can do.

  If the control example 4 is not performed, the suction unit 8 can be omitted from the configuration of the recording apparatus A.

<Second embodiment>
In the first embodiment, an example in which a web-like continuous sheet is used as a recording medium has been described. However, the present invention can also be applied to a recording apparatus that uses a cut sheet as a recording medium. In the first embodiment, serial recording has been described as an example, but the present invention can also be applied to line recording by a line head of a nozzle row corresponding to the maximum recording width, for example.

  FIG. 9 is a schematic diagram of a recording apparatus B that records an image on sheets C1 and C2, which are cut sheets. Here, the sheet C1 is a sheet conveyed in advance, and the sheet C2 is a subsequent sheet. Among the configurations of the recording apparatus B, configurations that are the same as or correspond to those of the recording apparatus A are denoted by the same reference numerals, and description thereof is omitted.

  In the case of the present embodiment, a transport unit 11 is provided instead of the supply unit 2. The transport unit 11 includes a transport roller 11a that is a driving roller, and a driven roller 11b that is pressed against the transport roller 11a. The cut sheet is nipped and conveyed by the conveyance roller 11a and the driven roller 11b. The conveyance unit 11 may constitute a part of a feeding mechanism, or may constitute an intermediate conveyance mechanism that conveys a cut sheet fed from a separately configured feeding mechanism. In the case of the present embodiment, the discharge unit 9 includes a plurality of presser spurs 9b that come into contact with the discharge roller 9a.

  In FIG. 9, the cut sheet C1 is where an ink image is formed in the vicinity of the rear end thereof. In FIG. 9, the cut sheet C <b> 2 is conveyed toward the recording unit 7 following the cut sheet C <b> 1. Although not shown, a plurality of cut sheets are continuously conveyed following the cut sheet C2. The ink applied to the cut sheet by the recording unit 7 is dried by being heated. The cut sheet that has been recorded is discharged by the discharge unit 9.

  FIG. 10 is a schematic diagram of a recording apparatus C that performs line recording. The recording apparatus C is an apparatus that records an image on sheets C1 and C2, which are cut sheets, as with the recording apparatus B. Good. Among the configurations of the recording apparatus C, configurations that are the same as or correspond to those of the recording apparatus B are denoted by the same reference numerals, and description thereof is omitted.

  In the recording apparatus C, the recording unit 7 includes a recording head 110 that is a line head. The recording head 110 is held at a position facing the platen heater 102. A configuration corresponding to the carriage 5, the recording head 10 and the like of the recording apparatus A is basically unnecessary. The recording head 110 is a recording head having a nozzle row having a width corresponding to the maximum sheet width assumed to be used. As an example, if the printer is capable of full-color recording, the heads for the necessary colors are sequentially arranged in the transport direction F. In the example of FIG. 10, a yellow line head 110Y, a magenta line head 110M, a cyan line head 110C, and a black line head 110Bk are arranged. Note that the above-described color types and the order of arrangement are merely examples, and the present invention can also be applied to color types and arrangements other than those described above.

  Since the recording head 110 has a nozzle row corresponding to the sheet width, there is no need to reciprocate the recording head 110 in the main scanning direction during recording, and recording can be performed at high speed while the sheet is continuously conveyed. Therefore, the characteristic of line recording is that the productivity is very high. The recording operation in the case of line recording will be described below.

  As described above, in the case of line recording, ink is continuously ejected from nozzles corresponding to the sheet width while the sheet is continuously conveyed. When a plurality of line heads of each color are arranged in the transport direction, the ink ejected from the upstream line head needs to be dried to some extent before the next ink is ejected from the downstream line head. is there.

  This is the same situation as in the case of multipass in serial recording described above, but in the case of line recording, the ink drying conditions are very severe in the following respects. That is, for example, in the case of line recording, the number of nozzles of the head is larger than that in serial recording. For this reason, the amount of ink applied on the sheet per unit time is remarkably large. Further, for example, in line recording, recording is performed while continuously conveying sheets, so that the time from ink ejection by the upstream line head to ink ejection by the line head adjacent to the downstream side is short. In the meantime, the ink on the sheet must be dried to some extent.

  As described above, the sheet temperature must be maintained at a stable temperature that does not fall below a predetermined temperature range as described above even under the severe condition of drying a large amount of ink in a short time. For this reason, in line recording, characteristics such as temperature stability in the platen heater 102 are required to be higher than in serial recording. For example, a countermeasure for increasing the amount of heat stored in the platen 102 can be considered.

  A large amount of heat storage means that the temperature drop due to heat dissipation after heating is stopped is slow. When a plurality of heater units 101 to 103 are stopped simultaneously after the recording operation is completed in such a recording apparatus C, the temperature difference between the main heater 102 and the adjacent heater units 101 and 103 having a relatively small heat storage amount further increases with time. It will be. As a result, wrinkles and irregularities occur in the sheet. For this reason, implementing the above-described control example is effective in preventing the occurrence of sheet wrinkling.

<Third embodiment>
In the first and second embodiments, the configuration in which the heating unit 100 includes a plurality of heater units that can be controlled independently is illustrated. However, the adsorption operation control of the control example 3 and the release operation control of the control example 4 can be performed even in a configuration in which the heating unit 100 does not include a plurality of heater units that can be controlled independently.

  FIG. 11 is a schematic diagram of the recording apparatus D of the present embodiment. Among the configurations of the recording apparatus D, configurations that are the same as or correspond to those of the recording apparatus A are denoted by the same reference numerals, and description thereof is omitted. In the example of FIG. 11, the web-like continuous sheet S is used as a recording medium, but a configuration using a cut sheet as a recording medium as in the second embodiment can also be adopted. Further, in the example of FIG. 11, the configuration for performing serial recording is used, but the configuration for performing line recording as in the second embodiment can also be adopted.

  In the present embodiment, the heating unit 100 includes only the platen heater 102. In the case of this configuration, the control example 1 and the control example 2 cannot be performed, but it is possible to prevent the sheet from being wrinkled by performing the suction operation control and the release operation control.

<Control example 5>
First, adsorption operation control in the present embodiment will be described. The contents of the suction operation control may be the same as in the control example 3, but a different example will be described here. 12A to 12C are explanatory diagrams of a control example. FIG. 14A is a flowchart of this example.

  FIG. 12A is a graph in which the vertical axis indicates the temperature of the sheet S and the horizontal axis indicates elapsed time. In the case of the present embodiment, when referred to as the temperature of the sheet S, it is the temperature of the region on the platen heater 102 (the temperature of the region RG2 in FIG. 1), which is the temperature detected by the temperature sensor 13. A curve L102 indicates the temperature of the sheet S on the platen heater 102.

  FIG. 12B is a timing chart showing the operation of the suction unit 8 by a curve V102, and FIG. 12C is a timing chart showing the output of the platen heater 102 by a curve H102. 12 (B) and 12 (C) have the same horizontal axis as FIG. 12 (A), and the vertical axis in FIG. 12 (B) shows the operation (adsorption and stoppage) of the adsorption unit 8, and FIG. 12 (C). The vertical axis indicates the operating status of the platen heater 102 (for example, the input power state).

  As an example, the environmental temperature is set to 25 ° C., and the set temperature of the sheet S is set to 60 ° C. during recording from time P1 to P2 or during recording standby from time P2 to P3 (steps S604 to S605 in FIG. 14A). When preparation for recording is started by a recording command at time P0 (step S601 in FIG. 14A), heating of the platen heater 102 is started in step S602.

  Here, the input power of the platen heater 102 at 60 ° C. is HIGH. At the same time, the suction unit 8 starts the suction of the sheet S. If it is determined in step S603 that the sheet S has reached a recordable temperature (for example, 60 ° C.), that is, if it is determined that the recording preparation is completed, recording starts at time P1 (step S604). Recording is performed between times P1 and P2 (steps S604 and S605). The recording operation is as described above.

  After the recording operation is completed at time P2, the recording standby mode indicated by times P2 to P3 is entered. In the recording standby mode, for example, the platen heater 102 and the suction unit 8 continue to be in the same state as during recording so that the next recording job can be started immediately, but recording is not being executed.

  Next, in step S606, when it is determined that a certain time elapses after the recording is completed and it is determined that the mode can be shifted to the power saving mode 1, the mode shifts to the power saving mode 1 indicated by time P3 to P4. The power saving mode 1 is a mode for shifting to a temperature lower than that at the time of recording, for example, 40 ° C. in time P3 (step S607) in order to reduce power consumption. As shown in FIG. 5C, here, the input power to the heater at 40 ° C. is LOW. At this time, since the suction of the sheet S by the suction unit 8 continues, the effect of suppressing wrinkles and unevenness is enhanced.

  In the power saving mode 1, since the platen heater 102 is not cooled to the environmental temperature, the start-up at the time of reheating can be shortened. For this reason, there is an advantage that recording can be started relatively quickly for a new recording job.

  If it is determined in step S608 that a condition such as a predetermined time has elapsed since the power saving mode 1 was started, the process shifts to the power saving mode 2 indicated by times P4 to P5. In the power saving mode 2, the heating of the platen heater 102 is stopped at time P4 (step S609), and the temperature of the sheet S decreases with the lapse of time as shown by the curve L102.

  The adsorption of the adsorption unit 8 is maintained until a predetermined condition is satisfied. Here, it is a condition that the temperature of the sheet S has decreased to a predetermined temperature. If it is determined in step S610 that the temperature of the sheet S has decreased to near the environmental temperature, the suction of the sheet S by the suction unit 8 is stopped at time P5 (step S611). After time P5, the main unit power can be turned off or the mode can be shifted to the sleep mode.

  Although it depends on the type and temperature conditions of the sheet S, there is an allowable temperature range in which wrinkles and irregularities do not occur even if there is a partial temperature difference of the sheet S, or at least does not cause a problem in actual use. If the temperature of the sheet S falls within the allowable temperature range before the temperature drops to around room temperature, the adsorption can be stopped. In this case, power consumption and noise due to adsorption can be reduced, and the time until the recording apparatus is stopped can be shortened. Further, if the sheet S is sucked by the suction negative pressure, the effect of air cooling of the platen heater 102 can be expected, so that the recording apparatus can be stopped in a shorter time compared to the case where no suction is performed.

  Thus, since the adsorption | suction of the sheet | seat S is continuing in the process in which the temperature of the sheet | seat S falls, the temperature of the sheet | seat S is stabilized and equalized, and the wrinkles and unevenness | corrugation accompanying a temperature change can be suppressed. Further, since the sheet S is held in a posture following the support surface by the suction, the flatness is maintained. Thereby, a high-quality sheet free from wrinkles and irregularities can be obtained.

  If the control example 5 is not performed, the suction unit 8 can be omitted from the configuration of the recording apparatus D.

<Control example 6>
Next, the release operation control in this embodiment will be described. The contents of the release operation control are substantially the same as in Control Example 4. FIG. 13A and FIG. 13B are explanatory diagrams of a control example. FIG. 14B is a flowchart of this example. The control example 6 can be combined with the control example 5.

FIG. 13A is a graph in which the vertical axis indicates the temperature of the sheet S and the horizontal axis indicates the elapsed time. As already described, when the temperature of the sheet S is referred to in this embodiment, it is the temperature of the region on the platen heater 102 (the temperature of the region RG2 in FIG. 1), and is the temperature detected by the temperature sensor 13.
A curve L102 indicates the temperature change of the sheet S in the platen heater 102.

  The platen heater 102 has a large heat storage amount for temperature stabilization. As an example, the ambient environment temperature is 25 ° C., and the temperature of the sheet S during recording or in the recording standby mode indicated by time P0 to P1 (step S701 in FIG. 14B) is 60 ° C., for example.

  FIG. 13B is a timing chart showing the operation of the release unit 6 by a curve P102. 13A is the same as the horizontal axis, and the vertical axis indicates the position of the pinch roller 3b moved by the release unit 6. “Holding” means that the pinch roller 3b is in the pressure contact position, and the sheet S is held between the pinch roller 3b and the conveying roller 3a. “Release” means that the pinch roller 3b is in the pressure release position, and the pinching of the sheet S by the pinch roller 3b and the conveying roller 3a is released.

  During the recording from time P0 to P1 or in the recording standby mode (step S701 in FIG. 14B), the pinch roller 3b holds the sheet S. Mode shift control for shifting to the power saving mode is executed in step S702. At time P1 (step S703), the platen heater 102 is stopped, and the release unit 6 releases at least a part of the holding of the sheet S by the transport unit 3. As shown by a curve L102 in FIG. 13A, the sheet S temperature corresponding to the platen heater 102 gradually decreases due to heat radiation after the time P1.

  The purpose of releasing the pinch is to release the distortion due to the expansion and contraction of the sheet due to heat, and therefore, there may be a slight amount before and after the heating stop timing. That is, the release of the clamping may be performed before the heat generation of the platen heater 102 is reduced (before stopping in this example) or after the heat generation of the platen heater 102 is reduced (after stopping in this example). Also good. This is because changes in distortion within a short time can be ignored. “Slightly before and after” is, for example, a short time in which the influence on the sheet S can be almost ignored, for example, about 1 minute. When the holding is released before the platen heater 102 is stopped, the timing for stopping the platen heater 102 may be set from the content of the recording job or the like, and the holding release timing may be set before that.

  In the case of nipping release, all the pinch rollers 3b may be moved to the pressure release position, but some of the pinch rollers 3b are released as described with reference to FIGS. 5A and 5B. May be located. The purpose of partially releasing the holding of the sheet S, in other words, continuing the holding in the remaining part is that the position of the entire sheet S is unintentionally shifted in the width direction and the conveying direction as described above. It is for preventing. By continuing clamping in the remaining portion, it is possible to prevent the sheet S from being skewed and the amount of blank space being changed during the next recording.

  In this way, by at least partially releasing the pinching by the pinch roller 3b, the distortion is released when the sheet S contracts, and the main body is turned off or the power saving mode such as the sleep mode is set while suppressing wrinkles and unevenness. Migration is possible. Thereby, unnecessary power consumption can be suppressed and the quality of the sheet can be maintained.

  In this example, by controlling the release unit 6 based on the operating state of the heating unit 100, the release unit 6 can be used to prevent the occurrence of wrinkles due to the temperature difference of the sheet S. That is, in the process of lowering the temperature of the sheet S, the holding of the sheet S by the transport unit 3 is at least partially released, so that the distortion due to the expansion and contraction of the sheet S due to heat is released. The sheet S can easily move with respect to the support portion 4 in the portion where the clamping is released, and the occurrence of distortion is suppressed. For this reason, wrinkles and unevenness can be suppressed.

  The same effect can be expected in the process of increasing the temperature. For example, the nipping of the sheet S may be released at least partially when heat generation of the heating apparatus 100 is started in order to resume recording after the main body power is turned off or the mode is shifted to the sleep mode. Distortion caused by thermal contraction or thermal expansion of the sheet S due to temperature change is released by at least partially releasing the holding of the sheet S by the transport unit 3, and wrinkles and unevenness due to thermal contraction due to temperature change of the sheet S are suppressed. be able to.

  By using the control example 5 and the control example 6 together, the sheet S is held in a posture following the support portion 4, so that the flatness is maintained. Thereby, a high-quality sheet free from wrinkles and irregularities can be obtained.

  If the control example 6 is not performed, the release unit 6 can be omitted from the configuration of the recording apparatus D.

<Other embodiments>
The present invention supplies a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program This process can be realized. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

  A to D recording apparatus, 3 transport unit, 6 release unit, 8 suction unit, 14 control unit, 100 heating unit, 101 to 104 heater unit

Claims (1)

Conveying means for nipping and conveying the sheet in the conveying direction;
A recording head provided downstream of the conveying means in the conveying direction and for discharging ink onto a sheet;
A support portion for supporting the sheet facing the recording head;
Heating means for heating the sheet from the lower side of the support part;
Wherein prior to lowering the heat generation of the heating means, Bei example and a release means for partially releasing the nipping of the sheet by the conveying means,
The conveying means is
A transport roller;
A plurality of pinch rollers pressed against the conveying roller,
The release means is capable of moving some pinch rollers of the plurality of pinch rollers between a pressure contact position and a pressure release position.
A recording apparatus.

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