JP2009154368A - Inkjet recording device - Google Patents

Abstract

An apparatus is miniaturized with respect to a conveyance direction.
An ink jet printer (1) is arranged between four ink jet heads (2), a belt transport device (50) for transporting paper (P) in the transport direction (A), and an ink jet head in the transport direction (A), and the paper (P) with respect to a transport surface (54). And a halogen lamp 73a that heats the roller 73 and a switch that switches between an energized state and a non-energized state for the halogen lamp 73a.
[Selection] Figure 1

Description

  The present invention relates to an ink jet recording apparatus that ejects ink onto a recording medium.

  Patent Document 1 discloses a transport unit that transports recording paper in the transport direction, four inkjet heads that are arranged at positions facing the transport unit and arranged along the transport direction, and the most between these heads and in the transport direction. An ink jet recording apparatus having four fixing means (heating means) arranged downstream of an ink jet head arranged downstream is described. In this ink jet recording apparatus, the ink ejected from each head onto the recording paper is fixed on the recording paper by fixing means located downstream in the transport direction of the head, thereby suppressing ink bleeding and color mixing.

JP 2005-288905 A

  However, in the ink jet recording apparatus described in Patent Document 1, since the fixing unit is provided between the heads, the distance between the heads in the transport direction is increased. When the distance between the heads is increased in this way, the front end of the recording paper conveyed by the conveying unit and the head are likely to come into contact with each other, and the recording paper is jammed between the head and the conveying unit, that is, jamming is likely to occur. . In order to prevent such a jam, it is possible to arrange a pressing member that presses the recording paper against the conveyance unit at a position adjacent to the fixing unit in the conveyance direction. However, if a pressing member is arranged in addition to the fixing unit, The inkjet recording apparatus itself is increased in size with respect to the transport direction.

  Accordingly, an object of the present invention is to provide an ink jet recording apparatus capable of downsizing the apparatus in the transport direction.

  An ink jet recording apparatus of the present invention has a plurality of ink jet heads having discharge surfaces on which discharge ports for discharging ink are formed, a transport surface for transporting a recording medium, and the transport surface facing the discharge surface. A conveying device that conveys the recording medium in the conveying direction by moving in the conveying direction; a first roller that is disposed between the inkjet heads in the conveying direction and presses the recording medium against the conveying surface; Heating means for heating the outer peripheral surface of the first roller.

  According to this, the first roller disposed between the heads can press the recording medium against the transport surface and heat the recording medium. Therefore, it is not necessary to separately provide both the heating means for heating the recording medium and the pressing member for pressing the recording medium, and the apparatus can be downsized in the transport direction.

  In the present invention, it is preferable that the image forming apparatus further includes a control unit that controls the heating unit so as to dry the ink discharged from the discharge port onto the recording medium. This makes it possible to control the drying of the ink ejected to the recording medium.

  At this time, the image forming apparatus further includes a second roller that is disposed on the downstream side of the ink jet head located on the most downstream side in the transport direction and presses the recording medium against the transport surface. The heating unit can also heat the outer peripheral surface of the second roller, and the control unit ejects ink to a recording medium among the first and second rollers. The heating means may be controlled so as to heat only the adjacent rollers on the downstream side in the transport direction. Thereby, the power consumption required for heating a roller can be reduced.

  Further, at this time, it further comprises first detection means for detecting the type of the recording medium, and the control means heats the first roller according to the type of the recording medium detected by the first detection means. The heating means may be controlled so as to adjust the temperature. Thereby, the heating temperature of the first roller can be adjusted to a temperature according to the type of the recording medium, so that the power consumption can be further reduced.

  At this time, the control means controls the heating means so as not to heat the first roller when the recording medium detected by the first detection means is a recording medium that does not require heating. Also good. Here, the recording medium that does not require heating is, for example, ink jet dedicated paper or a recording medium having quick drying properties. As a result, when the recording medium detected by the first detection means is, for example, ink-jet dedicated paper, it is possible to prevent the occurrence of conveyance failure due to the coating on the printing surface being in close contact with the heated first roller. In the case of a recording medium having quick drying properties, it is possible to prevent wrinkles from occurring on the paper by heating.

  Further, at this time, the first roller is moved between the first detecting means for detecting the type of the recording medium, and the pressing position where the first roller presses the recording medium and the separated position separated from the recording medium. A moving mechanism is further provided. The moving mechanism may move the first roller to the separation position when the recording medium detected by the first detection unit is a recording medium that does not require heating. Thereby, the ink discharged to the recording medium does not adhere to the roller.

  Further, at this time, the image forming apparatus further includes second detecting means for detecting whether or not the recording medium conveyed by the conveying device is separated from the conveying surface by a predetermined value or more. The conveyance of the recording medium may be stopped when the distance is more than the value. Thereby, it is possible to prevent the recording medium from being clogged between the conveyance surface and the ejection surface. Therefore, it is possible to prevent the discharge surface from being damaged when the recording medium is jammed.

  Further, at this time, the transport device has a plurality of holes formed in the transport surface, and a fan that sucks air through the holes to attract the recording medium to the transport surface, The fan may adsorb the recording medium to the transport surface when printing on the recording medium, and may suck air through the holes even after printing. Thereby, even after printing, air is sucked through the holes, so that the first roller heated by the air flow by the suction is cooled. For this reason, it is difficult for the ink in the vicinity of the ejection port to thicken by the heat of the roller.

  Further, at this time, the apparatus further includes a measuring unit that measures the temperature of at least one of the ejection surface and the first roller, and the fan is configured so that the temperature measured by the measuring unit is ink near the ejection port. The air may be sucked through the holes when the viscosity is equal to or greater than a predetermined value. As a result, the ink in the vicinity of the ejection port is less likely to thicken due to the heat of the heated first roller.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic side view of an inkjet printer according to an embodiment of the present invention. FIG. 2 is a plan view of the belt conveyance device 50 shown in FIG. 1 as viewed from above. FIG. 3 is an explanatory diagram illustrating a detection operation state in which the optical sensor 80 illustrated in FIG.

  As shown in FIG. 1, the inkjet printer 1 is a color inkjet printer having four inkjet heads 2. The inkjet printer 1 is provided with a paper feeder 10 on the left side in FIG. 1 and a paper discharge unit 40 on the right side in FIG. Between the paper feeding device 10 and the paper discharge unit 40, a belt conveyance device 50 that conveys the paper (recording medium) P conveyed from the paper supply device 10 toward the paper discharge unit 40 is provided. . In addition, the printer 1 is provided with a control unit 60 that controls these operations.

  As shown in FIG. 1, the paper feeding device 10 rotates a paper storage unit 11 that can store a plurality of stacked paper P, a pickup roller 12 that feeds the paper P from the paper storage unit 11, and a pickup roller 12. It has a paper feed motor 13 (see FIG. 4).

  The pickup roller 12 sends out the paper P by rotating and contacting the paper P positioned at the uppermost position among the plurality of papers P stored in the paper storage unit 11. The paper feed motor 13 is controlled by the control unit 60.

  In this configuration, the pickup roller 12 rotates counterclockwise in FIG. 1 under the control of the control unit 60, so that the paper P in contact with the pickup roller 12 is sent out to the belt conveyance device 50.

  The belt conveyance device 50 includes a pair of belt rollers 51 and 52, an endless conveyance belt 53 wound around the rollers 51 and 52, and conveyance that applies a driving force to rotate the belt roller 52. And a motor 59 (see FIG. 4). As shown in FIGS. 1 and 2, the transport belt 53 is formed with a plurality of holes 56 penetrating in the thickness direction over the transport surface 54 and the inner peripheral surface 55 which are outer peripheral surfaces. These holes 56 are formed in a distributed manner throughout the conveying belt 53.

  In a region surrounded by the conveyor belt 53, a substantially rectangular parallelepiped fan 57 is provided at a position facing the inkjet head 2. The fan 57 sucks air through a plurality of holes 56 existing between the inkjet head 2 and the fan 57 and sucks the paper P onto the transport surface 54. The transport motor 59 and the fan 57 are controlled by the control unit 60.

  In this configuration, the conveyor belt 53 is rotated by rotating the belt roller 52 in the direction of arrow B in FIG. At this time, the belt roller 51 as a driven roller also rotates with the rotation of the conveyance belt 53. At this time, by driving the fan 57 under the control of the control unit 60, the paper P sent out from the paper feeder 10 is attracted to the transport surface 54 in the transport direction A (in the direction of arrow A in FIG. 1). Be transported.

  A peeling member 9 is provided immediately downstream in the conveyance direction A of the belt conveyance device 50. The peeling member 9 is configured to peel the paper P adsorbed on the conveyance surface 54 from the conveyance surface 54 and to send the paper P toward the right paper discharge unit 40.

  The four inkjet heads 2 are arranged along the transport direction A in correspondence with four color inks (magenta, yellow, cyan, and black). That is, the ink jet printer 1 is a line printer. The inkjet head 2 has an elongated rectangular parallelepiped shape whose longitudinal direction extends in a direction perpendicular to the transport direction A (a direction perpendicular to the paper surface in FIG. 1). The inkjet head 2 has a laminate (both not shown) in which a flow path unit in which an ink flow path including a pressure chamber is formed and an actuator that applies pressure to the ink in the pressure chamber are bonded together. Ink is ejected from a large number of nozzles (not shown) formed on the ejection surface 2a which is the bottom surface.

  In the inkjet head 2, the discharge surface 2a and the conveyance surface 54 of the conveyance belt 53 facing the inkjet head 2 are parallel to each other, and a sheet conveyance path is formed between these surfaces. With this configuration, when the paper P transported by the transport belt 53 sequentially passes immediately below the four inkjet heads 2, each color of each color is ejected from the nozzle (discharge port) toward the upper surface (printing surface) of the paper P. Ink is ejected to form a desired color image.

  With respect to the transport direction A, the paper P is transported to the transport surface 54 so that the paper P transported by the belt transport device 50 does not float from the transport surface 54 between the ink jet heads 2 and immediately downstream of the most downstream ink jet head 2. Four pressing mechanisms 70a to 70d for pressing are provided. Since the four pressing mechanisms 70a to 70d have the same configuration, the pressing mechanism 70a will be described below, and the description of the remaining pressing mechanisms 70b to 70d will be omitted.

  The pressing mechanism 70a includes a roller 73 having a rotation axis that is parallel to the ejection surface 2a and parallel to a direction orthogonal to the transport direction A, and a roller moving mechanism 75 that moves the roller 73 in the vertical direction. The roller moving mechanism 75 includes a support member 76 that rotatably supports the roller 73 and a solenoid 77 that moves the roller 73 in the vertical direction together with the support member 76. The support member 76 is fixed to the rod 77 a of the solenoid 77. The solenoid 77 is controlled by the control unit 60.

  In this configuration, when the solenoid 77 is driven under the control of the control unit 60, the rod 77a of the solenoid 77 extends and the roller 73 presses the paper P against the transport surface 54 as shown in FIG. Move to position. On the other hand, when the drive of the solenoid 77 is stopped, the rod 77a contracts, and the roller 73 moves to a separation position separated from the paper P and the transport surface 54. The roller 73 included in the pressing mechanism 70d corresponds to the second roller, and the roller 73 included in the pressing mechanisms 70a to 70c corresponds to the first roller.

  The roller 73 is a metal cylindrical member, and as shown in FIG. 1, a halogen lamp 73a as a heat source is provided therein. The halogen lamp 73a is switched between an energized state (a state in which the roller 73 is heated) and a non-energized state (a state in which the roller 73 is not heated) by a switch 74 (see FIG. 4). The switch 74 is controlled by the control unit 60, and the ON / OFF timing and energization time for the halogen lamp 73a are controlled. In this embodiment, the temperature at which the roller 73 is heated is adjusted according to the length of the energization time. The halogen lamp 73a and the switch 74 constitute a heating means. Further, a temperature sensor (measuring means) 73b (see FIG. 4) is provided in the vicinity of the halogen lamp 73a, and measures the temperature of the roller 73.

  In this configuration, the outer peripheral surface of the roller 73 is heated by energizing the halogen lamp 73 a under the control of the control unit 60. At this time, if the roller 73 is in the pressing position, the paper P is sandwiched between the roller 73 and the transport surface 54, and the ink discharged onto the paper P is dried.

  As shown in FIG. 1, the printer 1 is provided with an optical sensor (second detection means) 80 on the upstream side of the inkjet head 2 that is the most upstream in the transport direction A. The optical sensor 80 detects floating of the paper P from the transport surface 54 when the paper P is separated from the transport surface 54 by a predetermined distance (predetermined value) or more. Specifically, the optical sensor 80 includes a light emitting unit 81 and a light receiving unit 82 that receives light emitted from the light emitting unit 81. The light emitting unit 81 is located at the upper side in FIG. 2 is arranged in the lower part of FIG.

  As shown in FIG. 3, the light emitting unit 81 includes a light irradiation unit 81 a that irradiates light in a direction orthogonal to the transport direction A at a position away from the transport surface 54 in the vertical direction by a predetermined distance. This predetermined distance is determined when the paper P is transported to a position facing the ejection surface 2a when the paper P is lifted from the transport surface 54 to the extent that the paper P blocks the light emitted from the light irradiation unit 81a. The distance between the paper P and the ejection surface 2a is too short, and the distance between the conveyance surface 54 and the ejection surface 2a is likely to be jammed.

  In this configuration, as shown in FIG. 3A, when the paper P conveyed by the conveying belt 53 is sent in close contact with the conveying surface 54 without floating, and the paper P is conveyed by the conveying surface 54. If the light irradiating portion 81a does not overlap even if it floats slightly, the paper P is not detected by the optical sensor 80. On the other hand, as shown in FIG. 3B, the sheet P conveyed by the conveying belt 53 is curled at the front end and the front end is lifted from the conveyance surface 54, and the front end of the sheet P is the light irradiation unit 81a. , The light irradiated from the light irradiation unit 81a is blocked by the paper P. At this timing, the optical sensor 80 detects the paper P, and the detection signal is transmitted to the control unit 60. Thus, it is detected by the optical sensor 80 that the paper P is separated from the transport surface 54 by a predetermined value or more.

  In FIG. 3B, the front end of the paper P passes through a position that blocks the light emitted from the light irradiation unit 81a. However, not only the front end of the paper P but also a portion of the paper P emits light. When floating up to the blocking position from the conveyance surface 54, the light is blocked by the portion, and it can be detected whether or not the paper P is separated from the conveyance surface 54 by a predetermined value or more.

  Next, the control unit 60 will be described. The control unit 60 is configured by, for example, a general-purpose personal computer. Such a computer stores hardware such as a CPU, ROM, RAM, and hard disk, and various software including a program for controlling the operation of the printer 1 is stored in the hard disk. And these parts and 61-69 (refer FIG. 4) mentioned later are constructed | assembled by combining these hardware and software.

  FIG. 4 is a block diagram illustrating a schematic configuration of the control unit 60. The control unit 60 includes a print control unit 61, a conveyance control unit 62, a storage unit 63, a heating temperature storage unit 64, a thickening temperature storage unit 65, a determination unit 66, a fan control unit 67, a heating control unit 68, and a roller movement control unit. 69 is included. The print controller 61 controls ink ejection from each inkjet head 2 so that an image is formed at a desired position on the paper P after a predetermined time has elapsed since the paper P was conveyed by the pickup roller 12.

  The transport control unit 62 controls the paper feed motor 13 and the transport motor 59 so as to transport the paper P from the paper feeding device 10 to the paper discharge unit 40. Further, the conveyance control unit 62 stops the conveyance of the paper P when the floating of the paper P is detected by the optical sensor 80 and the paper P detected by the determination unit 66 is other than the paper that needs to be heated. Thus, the paper feed motor 13 and the transport motor 59 are controlled.

  The storage unit 63 stores paper type data selected by the user, which is included in the print data transmitted to the control unit 60. The heating temperature storage unit 64 stores, for example, roller heating temperatures corresponding to a plurality of types of paper such as plain paper and postcards that need to be heated. Note that the paper that needs to be heated here means that if the paper on which the ink is ejected is not heated, when the user holds the paper discharged to the paper discharge unit 40, the ink is placed in the user's hand. This refers to paper that has a possibility that the printed image may be disturbed by adhesion or contact with ink. The thickening temperature storage unit 65 stores a lower limit temperature (predetermined value) at which the ink in the vicinity of the nozzles easily thickens.

  Based on the paper type data stored in the storage unit 63, the determination unit 66 determines that the paper type in the current printing is plain paper or postcard that needs to be heated, and dedicated inkjet paper that does not need to be heated. The paper type is determined by determining which of the papers has quick drying properties. As described above, in the present embodiment, the recording unit 63 and the determination unit 66 constitute a first detection unit. The determination unit 66 determines whether or not the temperature measured by the temperature sensor 73 b is equal to or higher than the lower limit temperature stored in the thickening temperature storage unit 65.

  The fan control unit 67 controls the fan 57 so that air is sucked from the holes 56 when the paper P is conveyed by the belt conveyance device 50. In addition, the fan control unit 67 causes the fan to suck air from the hole 56 when the determination unit 66 determines that the measured temperature is equal to or higher than the stored lower limit temperature after printing on the paper P is completed. 57 is controlled.

  The heating control unit 68 controls the switch 74 so as to heat only the roller 73 adjacent downstream of the inkjet head 2 in which the ink is discharged based on the print data transmitted to the control unit 60 in the transport direction A. In the present embodiment, since the rollers 73 corresponding to the heads 2 are provided, the rollers 73 corresponding to the heads 2 to which ink is not ejected are not heated. Further, the heating control unit 68 controls the switch 74 so as to adjust the heating temperature of the roller 73 according to the paper type detected by the determination unit 66.

  When the paper type detected by the determination unit 66 is plain paper or postcard that needs to be heated, the roller movement control unit 69 moves each of the pressing mechanisms 70a to 70b so that all the rollers 73 move to the pressing position. 70d solenoid 77 is controlled. Further, the roller movement control unit 69 causes all the rollers 73 to move to the separation position when the paper type detected by the determination unit 66 is an inkjet dedicated paper that does not need to be heated or a paper having quick drying properties. The solenoids 77 of the pressing mechanisms 70a to 70d are controlled.

  Next, the printing operation in the printer 1 will be described with reference to FIG. FIG. 5 is an operation state diagram when printing is performed on a sheet that needs to be heated in the inkjet printer 1 of the present embodiment. When print data is transmitted from a PC (personal computer) or the like to the control unit 60, the conveyance control unit 62 sends out the paper P from the paper storage unit 11 to the belt conveyance device 50 as shown in FIG. Thus, the paper feed motor 13 is driven. At this time, the determination unit 66 determines the paper type selected by the user. This time, the case where the determination unit 66 determines that the paper is a plain paper or postcard that needs to be heated will be described below.

  The transport control unit 62 drives the transport motor 59 so that the paper P sent out from the paper storage unit 15 is transported in the transport direction A. At this time, the fan control unit 67 drives the fan 57 so that the paper P conveyed by the conveyance belt 53 is in close contact with the conveyance surface 54. At this time, the roller movement control unit 69 drives the four solenoids 77 so that all the rollers 73 move from the separation position shown in FIG. 5A to the pressing position shown in FIG.

  Further, at this time, the heating control unit 68 is detected by the determination unit 66 so as to heat the roller 73 corresponding to the inkjet head 2 on which ink ejection is performed based on the print data transmitted to the control unit 60. Further, the ON / OFF switching of the switch 74 and the energization time for the halogen lamp 73a are controlled so as to adjust the heating temperature of the roller 73 according to the plain paper or postcard. Thus, by adjusting the heating temperature of the roller 73 to a temperature corresponding to the type of the paper P, it is possible to reduce the power consumption necessary for heating the roller 73. In this printing operation, since ink is ejected from all the inkjet heads 2, the four rollers 73 are heated. In the present embodiment, the heating temperature of the roller 73 is adjusted by adjusting the length of time for which the switch 74 is turned on. However, it is also possible to adjust the current value for energizing the halogen lamp 73a. is there. Further, among the four inkjet heads 2, for example, when ejecting ink only from the inkjet head 2 ejecting black ink, only the roller 73 corresponding to the one inkjet head 2 may be heated. By doing so, it is possible to further reduce the amount of power consumption required to heat the roller 73.

  Next, when the paper P passes between the light emitting unit 81 and the light receiving unit 82 of the optical sensor 80 and is not detected by the optical sensor 80, the paper P is conveyed by the belt conveying device 50 as it is. On the other hand, even if the paper P is detected by the optical sensor 80 and the detection signal is transmitted to the control unit 60, the paper P detected by the determination unit 66 is a paper P that needs to be heated. Since the sheet P is pressed against the conveyance surface 54 by 73, the conveyance control unit 62 conveys the sheet P by the belt conveyance device 50 in the same manner as when the sheet P is not detected by the optical sensor 80.

  Next, when the paper P is transported to an area facing the inkjet head 2 by the belt transport device 50, the print control unit 61 sends out the paper P from the paper storage unit 11, and then the paper P is connected to each inkjet head 2. Each inkjet head 2 is controlled such that ink is ejected from the inkjet head 2 after a lapse of a predetermined time passing through the opposed regions. At this time, the ink ejected from the inkjet head 2 onto the paper P is dried while being sandwiched between the roller 73 heated to a predetermined temperature corresponding to the inkjet head 2 and the transport surface 54 as the paper P is transported. . Thus, an image is formed at a desired position on the paper P.

  The paper P on which the image is formed is peeled off from the transport belt 53 by the peeling member 9 and then discharged to the paper discharge unit 40. Thereafter, the control of the control unit 60 stops the driving of the paper feed motor 13, the transport motor 59, and the solenoid 77, and the switch 74 is turned off. At this time, when the determination unit 66 determines that the temperature measured by the temperature sensor 73 b is lower than the lower limit temperature stored in the thickening temperature storage unit 65, the fan control unit 67 stops driving the fan 57. On the other hand, when the determination unit 66 determines that the measured temperature is equal to or higher than the stored lower limit temperature, the fan control unit 67 drives the fan 57 as it is for a predetermined time. By performing such control, air is sucked through the holes 56 even after printing, so that the roller 73 heated by the air flow by this suction is rapidly cooled, and the ink near the nozzle is heated by the heat of the roller 73. It becomes difficult to thicken.

  Next, the case where the type of the paper P on which printing is performed is determined as the inkjet dedicated paper that does not need to be heated and the paper having quick drying properties by the determination unit 66 will be described below.

  In this case, the transport control unit 62 and the fan control unit 67 drive the transport motor 59 and the fan 57 as in the previous operation, but the heating control unit 68 does not heat any roller 73, and the switch 74 is used. Control to turn off the. Accordingly, it is possible to prevent a conveyance failure due to the coating formed on the printing surface of the inkjet dedicated paper being in close contact with the heated roller 73, and to heat the paper by heating when the paper has quick drying properties. Can prevent wrinkles from occurring. At this time, the roller movement control unit 69 performs control to stop driving the solenoid 77. In other words, the roller 73 is disposed at the separation position and does not contact the paper P conveyed by the belt conveyance device 50. As a result, the ink ejected on the paper P does not adhere to the roller 73, and the image formed on the paper P does not become distorted.

  Next, when the paper P passes between the light emitting unit 81 and the light receiving unit 82 of the optical sensor 80 and is not detected by the optical sensor 80, the paper P is conveyed by the belt conveying device 50 as it is. When detected by the optical sensor 80 and the detection signal is transmitted to the control unit 60, the conveyance control unit 62 stops driving the paper feed motor 13 and the conveyance motor 59 so as to stop the conveyance of the paper P. Thereby, it is possible to prevent the paper P from being jammed between the transport surface 54 and the discharge surface 2a. Therefore, it is possible to prevent the discharge surface 2a from being damaged when the paper P is jammed. At this time, the fan control unit 67 stops driving the fan 57.

  Next, when the paper P is not detected by the optical sensor 80 and the paper P is transported to an area facing the inkjet head 2 in close contact with the transport surface 54, the print control unit 61 moves the paper from the paper storage unit 11 to the paper. Each ink-jet head 2 is controlled such that ink is ejected from the ink-jet head 2 after a predetermined time elapses after the sheet P passes through the region facing the ink-jet head 2. Thus, an image is formed at a desired position on the paper P. The paper P on which the image is formed is peeled off from the transport belt 53 by the peeling member 9 and then discharged to the paper discharge unit 40. Thereafter, the drive of the paper feed motor 13 and the transport motor 59 is stopped under the control of the control unit 60.

  As described above, according to the ink jet printer 1 of the present embodiment, the roller 73 disposed between the heads presses the paper P against the transport surface 54 and heats the paper P on which the ink has been ejected. Can be dried. Therefore, it is not necessary to separately provide both a heating means for heating the paper P and a pressing member for pressing the paper P, and the apparatus can be downsized in the transport direction A. Further, since the control unit 60 is provided, the switch 74 can be controlled to dry the ink ejected onto the paper P.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the above-described embodiment, four rollers 73 corresponding to each inkjet head 2 are provided, but one roller may be provided between the heads. Further, the heating temperature of the roller 73 may not be adjusted according to the paper type. In this case, the storage unit 63 and the heating temperature storage unit 64 may not be provided, and the determination unit 66 may not detect the paper type. Therefore, the control configuration is simplified. Further, the temperature sensor 73b and the thickening temperature storage unit 65 may not be provided. In this case, the determination unit 66 does not need to determine whether or not the temperature measured by the temperature sensor 73b is equal to or higher than the lower limit temperature stored in the thickening temperature storage unit 65, and the control configuration is simplified. In addition, when printing is performed only on paper that needs to be heated, the roller 73 may be always heated when printing on the paper. In addition, the roller 73 may always be in a state of pressing the sheet against the conveyance surface 54. In this case, an urging means for urging the roller 73 toward the conveying surface 54 may be provided instead of the roller moving mechanism 75. In addition, when the transport surface is sticky or when the paper P can be brought into close contact with the transport surface by electrostatic adsorption, the fan 57 and the transport belt 53 are provided with a plurality of holes 56. It does not have to be. In the above-described embodiment, the conveyance of the paper P is performed by the belt conveyance device 50. However, the conveyance device that conveys the paper is not limited to the belt conveyance device 50, and the paper is formed by a rotatable drum. It may be a drum transport device that transports P.

1 is a schematic side view of an inkjet printer according to an embodiment of the present invention. It is a top view when the belt conveying apparatus shown in FIG. 1 is viewed from above. FIG. 3 is an explanatory diagram illustrating a detection operation state for detecting the floating of a sheet by the optical sensor illustrated in FIG. 1. It is a block diagram which shows schematic structure of the control part shown in FIG. In the ink jet printer of this embodiment, it is an operation | movement condition figure when printing on the paper which needs to be heated.

Explanation of symbols

1 Inkjet printer (inkjet recording device)
2 Inkjet head 2a Discharge surface 50 Belt conveying device (conveying device)
54 conveying surface 56 hole 57 fan 60 control unit (control means)
63 Recording unit (part of first detection means)
66 Determination unit (part of first detection means)
73 rollers (first and second rollers)
73a Halogen lamp (part of heating means)
73b Temperature sensor 74 switch (part of heating means)

Claims (9)

A plurality of inkjet heads having an ejection surface on which ejection ports for ejecting ink are formed;
A transport device that transports the recording medium in the transport direction by having a transport surface that transports the recording medium, and moving the transport surface in the transport direction while facing the discharge surface;
A first roller disposed between the inkjet heads in the transport direction and pressing a recording medium against the transport surface;
An ink jet recording apparatus comprising: a heating unit that heats an outer peripheral surface of the first roller.   The inkjet recording apparatus according to claim 1, further comprising a control unit that controls the heating unit so as to dry the ink discharged from the discharge port onto the recording medium. A second roller that is disposed on the downstream side of the inkjet head located on the most downstream side in the transport direction and presses the recording medium against the transport surface;
The heating means can also heat the outer peripheral surface of the second roller,
The control unit controls the heating unit so as to heat only the roller adjacent to the inkjet head that has ejected ink to the recording medium on the downstream side in the transport direction, among the first and second rollers. The inkjet recording apparatus according to claim 2, wherein: A first detecting means for detecting the type of the recording medium;
4. The control unit according to claim 2, wherein the control unit controls the heating unit to adjust a heating temperature of the first roller in accordance with a type of the recording medium detected by the first detection unit. 2. An ink jet recording apparatus according to 1.   The control means controls the heating means so as not to heat the first roller when the recording medium detected by the first detection means is a recording medium that does not require heating. Item 5. The ink jet recording apparatus according to Item 4. First detection means for detecting the type of the recording medium;
A moving mechanism for moving the first roller between a pressing position where the first roller presses the recording medium and a separation position separated from the recording medium;
The said moving mechanism moves the said 1st roller to the said separation position, when the recording medium detected by the said 1st detection means is a recording medium which does not require a heating. The inkjet recording apparatus according to any one of the above. A second detecting means for detecting whether or not the recording medium conveyed by the conveying device is separated from the conveying surface by a predetermined value or more;
The inkjet recording apparatus according to claim 6, wherein the conveyance device stops conveyance of the recording medium when the recording medium is separated from the predetermined value or more. The transport device has a plurality of holes formed in the transport surface, and a fan that attracts a recording medium to the transport surface by sucking air through the holes,
8. The fan according to claim 1, wherein when the printing is performed on the recording medium, the recording medium is attracted to the transport surface and air is sucked through the hole even after printing. The ink jet recording apparatus according to any one of the above. A measuring means for measuring the temperature of at least one of the discharge surface and the first roller;
9. The fan according to claim 8, wherein the fan sucks air through the hole when the temperature measured by the measuring unit is equal to or higher than a predetermined value for thickening ink in the vicinity of the ejection port. Inkjet recording device.

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