Image forming device

Abstract

To provide an image forming device that can improve heating stability of a recording material in a heating part.SOLUTION: The image forming device is configured to comprise a recording material heating part arranged at an upstream side of an image forming part, an enclosure covering the recording material heating part, a pressurizing part, provided in the enclosure, which enhances air pressure in the enclosure, and a gas inflow port, formed in the enclosure, through which air is supplied from the outside of the enclosure to pressurizing part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] There are image forming apparatuses that eject ink onto a recording material to form an image on the recording material. Many of the inks used in image forming apparatuses have final states, such as color and gloss, that differ depending on the temperature state after landing on the recording material. In such cases, temperature control for heating the recording material to an appropriate temperature is important. As a method for heating a recording material to an appropriate temperature before ink lands on it, a configuration in which a contact-type heating section using a heating roller or the like is provided upstream of an image forming section is widely used (see, for example, Patent Document 1). In this heating section, the recording material to which ink is to be ejected is brought into contact with the heating roller, and the recording material is heated to an appropriate temperature in advance before ink lands on it.

[0003] On the other hand, contact-type heating units using a heating roller or the like have problems such as fine scratches on the surface of the recording material, and the effect of surface modification such as corona treatment is reduced due to heat and pressure. For this reason, a configuration of an image forming apparatus equipped with a non-contact type heating unit using a sheath heater or the like has been proposed. However, in the non-contact heating method, air caught in the recording material being conveyed enters the heating section, which causes problems such as a decrease in the efficiency of heating the recording material and a decrease in the uniformity of the in-plane temperature of the recording material, resulting in a decrease in heating stability. As a countermeasure to this, an image forming apparatus has been proposed in which a temperature sensor is provided between two heating sections, and the temperature from the first heating section is fed back to the control of the second heating section (see, for example, Patent Document 2). Also, an image forming apparatus has been proposed in which air is blown alternately from the conveyance width direction in order to improve the uniformity of the in-plane temperature (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-104198 A [Patent Document 2] JP 2010-162701 A [Patent Document 3] JP 2011-056900 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned configuration cannot sufficiently suppress the deterioration of the heating stability of the recording material caused by the inflow of air into the heating section. In particular, in recent years, there has been a demand for faster conveying speeds of recording materials, and therefore further improvement of the heating stability is required.

[0006] In order to solve the above-mentioned problems, the present invention provides an image forming apparatus capable of improving the heating stability of a recording material in a heating section. [Means for solving the problem]

[0007] The image forming apparatus of the present invention has a conveying section that conveys a recording material, an image forming section that ejects ink onto the conveyed recording material, and a recording material heating section that heats the recording material, which is arranged upstream of the image forming section in the conveying direction of the recording material by the conveying section.The image forming apparatus also has a housing that covers the recording material heating section and has a recording material inlet provided upstream in the recording material conveying direction and a recording material outlet provided downstream, a pressure section provided within the housing that increases the air pressure within the housing, and an air inlet provided in the housing that supplies air to the pressure section from outside the housing.

[0008] In addition, the image forming apparatus of the present invention includes a transport section that transports the recording material, an image forming section that ejects ink onto the transported recording material, a recording material heating section that heats the recording material and is arranged upstream of the image forming section in the recording material transport direction, and a housing that covers the recording material heating section and has a recording material inlet provided upstream in the recording material transport direction, and a recording material outlet having an opening area smaller than that of the recording material inlet provided downstream. Effect of the Invention

[0009] According to the present invention, it is possible to provide an image forming apparatus capable of improving the heating stability of the recording material in the heating section. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of an image forming apparatus according to a first embodiment. [Diagram 2] 13 is a diagram showing the configuration of a heating unit in which a pressure unit is not provided inside a housing. FIG. [Diagram 3] 1 is a block diagram showing a main configuration of an image forming apparatus; [Figure 4] FIG. 11 is a diagram showing a heating unit and a part of an image forming unit of an image forming apparatus according to a second embodiment. [Diagram 5] FIG. 13 is a diagram showing a heating unit and a part of an image forming unit of an image forming apparatus according to a third embodiment. [Figure 6] FIG. 13 is a diagram showing a heating unit and a part of an image forming unit of an image forming apparatus according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, examples of embodiments of the present invention will be described, but the present invention is not limited to the following examples. The explanation will be given in the following order. 1. First embodiment of image forming apparatus 2. Second embodiment of image forming apparatus 3. Third embodiment of image forming apparatus 4. Fourth embodiment of image forming apparatus

[0012] 1. First embodiment of image forming apparatus Hereinafter, a specific embodiment of the image forming apparatus of the present invention will be described. A schematic configuration diagram of an image forming apparatus according to the present embodiment is shown in Fig. 1. The image forming apparatus 1 shown in Fig. 1 includes a recording material supplying section 10, a heating section 20, an image forming section 30, a recording material discharging section 40, and a control section 50 (not shown) (see Fig. 3).

[0013] [Recording material supply section] The recording material supplying section 10 includes a loading tray 11 and a delivery roller 12. The recording material supplying section 10 stores the recording material S on the loading tray 11, and drives the delivery roller 12 at an appropriate timing when performing image formation to supply the recording material S to the heating section 20 in order.

[0014] The loading tray 11 is a plate-like member on which recording materials S can be stacked and sends the uppermost recording material S to the heating section 20. The recording material S loaded on the loading tray 11 is not particularly limited, but examples thereof include films, acrylic plates, resin plates such as PET, sheets of paper, thick paper, and corrugated cardboard. The loading tray 11 is movable in the vertical direction, and here, the position is maintained such that the uppermost recording material S is held at a sending position to the heating section 20 according to the total weight of the loaded recording materials S, etc.

[0015] The delivery rollers 12 sandwich the recording material S from above and below and deliver it to the heating unit 20. The recording material supply unit 10 has a guide member (not shown) that limits the recording material S to a predetermined range in a direction (width direction) perpendicular to the delivery direction (conveyance direction) within the conveyance surface of the recording material S. The delivery rollers 12 deliver the recording material S at an appropriate position and orientation.

[0016] [Heating section] The heating section 20 has a first recording material heating section 22 that heats the image forming surface side of the recording material S being conveyed, and a second recording material heating section 23 that heats the back side of the recording material S. The heating section 20 also has a housing 21 that covers the first recording material heating section 22 and the second recording material heating section 23. The housing 21 has a recording material entrance 24 provided on the upstream side in the conveying direction of the recording material S, and a recording material exit 25 provided on the downstream side. The heating section 20 also has a pressurizing section 26 that increases the air pressure inside the housing 21, and an air inlet 27 provided in the housing 21 to supply air 70 from outside the housing 21 to the pressurizing section 26. The flow of air in the heating section 20 is illustrated by arrows.

[0017] Furthermore, the heating unit 20 includes a temperature sensor 226 (FIG. 3), not shown. The temperature sensor 226 measures the temperature of the air inside the housing 21 and outputs the measured temperature to the control unit 50 (FIG. 3). As the temperature sensor 226, a conventionally known semiconductor temperature sensor or the like can be used.

[0018] (First recording material heating section, second recording material heating section) The first recording material heating section 22 and the second recording material heating section 23 are not particularly limited as long as they are configured to heat the recording material S in a non-contact manner, and for example, non-contact heating devices such as a sheath heater, a carbon heater, or a cartridge heater can be used.

[0019] The heating of the recording material S in the heating section 20 is for the purpose of controlling the state of the ink after it lands on the recording material S, and is aimed at controlling the temperature of the image forming surface of the recording material S. For this reason, the heating section 20 heats the recording material S so that the temperature becomes appropriate when the ink lands. The output of the heating section 20 is controlled by the control section 50 (FIG. 3) based on the temperature of the air inside the housing 21 measured by a temperature sensor 226 (FIG. 3).

[0020] The first recording material heating section 22 and the second recording material heating section 23 are each independently controlled by a control section 50 (FIG. 3). By independently controlling the first recording material heating section 22 and the second recording material heating section 23, it is possible to heat the image forming surface and the back surface of the recording material S to different temperatures. In particular, the temperature of the back surface side of the recording material S may be set to a different temperature from that of the image forming surface, taking into account the heat transfer of the recording material S for temperature control of the image forming surface. In this way, by having the control unit 50 independently control the output of the first recording material heating section and the output of the second recording material heating section, it is possible to control the temperature of the image forming surface of the recording material S with greater precision.

[0021] (Housing) The housing 21 is a member that covers the first recording material heating section 22 and the second recording material heating section 23 and retains air inside. The housing 21 is provided with a recording material entrance 24, which is a slit-shaped opening that allows the recording material S to pass, at an upstream end (receiving end) in the conveying direction of the recording material S. The housing 21 is also provided with a recording material discharge port 25, which is a slit-shaped opening that allows the recording material S to pass, at a downstream end (sending end) in the conveying direction of the recording material S.

[0022] Furthermore, the housing 21 is provided with a gas inlet 27 for supplying air 70 to the pressurizing unit 26. The gas inlet 27 is provided at a position separate from the recording material inlet 24 and the recording material outlet 25, and is provided at a position where the air 70 can be sent to the pressurizing unit 26. Preferably, the gas inlet 27 is provided at a position facing the recording material inlet 24 across the pressurizing unit 26. That is, the gas inlet 27 is provided at a position where the air 70 flowing in from the gas inlet 27 passes through the pressurizing unit 26 and then reaches the recording material inlet 24. For this reason, the gas inlet 27 is formed in the housing 21 based on the relative positional relationship between the arrangement of the pressurizing unit 26 and the recording material inlet 24.

[0023] It is preferable that the housing 21 is sealed except for the recording material inlet 24, the recording material outlet 25, and the gas inlet 27. This prevents air from flowing into the housing 21. In addition, the housing 21 can be configured to further prevent heat from entering or leaving by using a well-known material with high thermal insulation properties. The inside of the housing 21 may or may not be visible.

[0024] (Pressure section) Pressurizing unit 26 is provided in housing 21 in order to keep the air pressure inside housing 21 higher than the air pressure outside housing 21. For example, a blower or an air compressor can be used as pressurizing unit 26. The drive and output of pressurizing unit 26 are controlled by control unit 50 (FIG. 3). Control unit 50 controls the drive and output of pressurizing unit 26, thereby enabling the air pressure inside housing 21 to be controlled.

[0025] Further, a gas inlet 27 for supplying air 70 from the outside to the pressurizing unit 26 is provided in the housing 21, and the air 70 is supplied to the pressurizing unit 26 from the gas inlet 27. Therefore, the air 70 is sent into the housing 21 by the pressurizing unit 26, and the overall air pressure inside the housing 21 becomes higher than the air pressure outside the housing 21. In this way, by increasing the air pressure inside the housing 21 by the pressurizing section 26, it is possible to suppress the inflow of air into the housing 21 when the recording material S is transported to the housing 21.

[0026] For example, the configuration of the heating section 20 in which the pressure section 26 is not provided inside the housing 21 is shown in Fig. 2. Fig. 2 is a diagram showing the heating section 20 and a part of the image forming section 30 in the image forming apparatus 1 shown in Fig. 1. Fig. 2 shows a state in which the recording material S is being conveyed inside the housing 21. Fig. 2 also shows only the image forming operation section 33 and the support section 321 as the image forming section 30.

[0027] 2, the recording material S is transported into the housing 21 from the recording material inlet 24. At this time, external air 71 flows into the housing 21 from the recording material inlet 24 so as to be caught in the transport of the recording material S. Then, air 72 that has flowed into the housing 21 enters between the first recording material heating section 22 and the second recording material heating section 23 and the recording material S.

[0028] When the image forming apparatus 1 is in operation, the temperature inside the housing 21 is usually higher than the outside due to the first recording material heating section 22 and the second recording material heating section 23. For this reason, the temperature inside the housing 21 drops due to the inflow of air 71 from the outside. Also, the first recording material heating section 22 and the second recording material heating section 23 are cooled on the upstream side in the transport direction of the recording material S inside the housing 21 by the air 72 that has entered the housing 21. For this reason, in the heating section 20, the temperature on the upstream side is lower than the temperature on the downstream side, and the uniformity of the in-plane temperature inside the heating section 20 decreases. Thus, in the heating unit 20, the inflow of the air 71 into the housing 21 reduces the heating stability of the recording material S. In particular, the higher the conveying speed of the recording material S, the more the air 71 that is caught in the conveyance of the recording material S and flows into the housing 21, and the more likely the heating stability is to decrease.

[0029] 1, a pressure applying section 26 is provided in the housing 21, and the air pressure inside the housing 21 is made higher than that outside the housing 21. This makes it possible to prevent air 71, which is caught in the conveyance of the recording material S, from flowing into the housing 21. As a result, it is possible to prevent a decrease in the uniformity of the in-plane temperature caused by the flow of air 72 into the heating section, and to sufficiently prevent a decrease in the heating stability of the recording material S in the heating section 20.

[0030] [Image forming section] The image forming section 30 is provided downstream of the heating section 20 in the conveying direction of the recording material S. The image forming section 30 ejects and fixes ink onto the surface of the recording material S conveyed from the heating section 20 to form an image, and sends the recording material S with the fixed ink to a recording material discharge section 40. The image forming section 30 includes a conveying section 31, support sections 321, 322, and 323, an image forming operation section 33, a fixing section 34, a reading section 35, and the like.

[0031] The conveying section 31 includes a conveying belt 311, a driving roller 312, and a driven roller 313. The conveying belt 311 is an endless belt-like member that is longer than the recording material S and is stretched between the driving roller 312 and the driven roller 313. Although there is no particular limitation, a resin or steel belt is used as the conveying belt 311. The conveying belt 311 moves in a circular motion when the driving roller 312 is rotated and driven by a conveying motor 315 (see FIG. 3). As a result, the recording material S placed on the outer circumferential surface (conveying surface) of the conveying belt 311 is conveyed at the circular movement speed of the conveying belt 311. Note that, in this example, a single conveying belt 311 conveys the recording material S from the heating section 20 to the recording material discharge section 40, but the recording material S may be conveyed by being handed over by a plurality of conveying belts.

[0032] The support parts 321, 322, and 323 are provided along the conveyor belt 311 on the inner circumferential surface side of the conveyor belt 311. The support part 321 is provided in a range including a range corresponding to the ink ejection range of the image forming operation part 33. The support part 322 is provided in a range including a range corresponding to the ink fixing range of the fixing part 34. The support part 323 is provided in a range including a range corresponding to the reading range by the reading part 35. The support parts 321, 322, and 323 support the conveyor belt 311 moving in a circumferential direction, thereby supporting the recording material S placed on the conveyor belt 311 and keeping the recording material S at an appropriate position in the ink ejection range, the ink fixing range, and the reading range, respectively. Preferably, the support parts 321, 322, and 323 have fine holes, and can be configured to more stably adsorb the recording material S to the conveyor belt 311 by sucking from the opposite side of the contact surface with the conveyor belt 311.

[0033] The image forming operation unit 33 has an inkjet head 331 provided with nozzles, etc. The image forming operation unit 33 forms a two-dimensional image on the recording material S by sequentially ejecting ink from the inkjet head 331 onto the recording material S placed on the conveyor belt 311 and conveyed in the conveying direction. The image forming operation unit 33 is capable of ejecting ink at once across a predetermined image formation width onto the conveyed recording material S. The image forming operation unit 33 also ejects ink from the nozzles of the inkjet head 331 within an ink ejection range at appropriate timing.

[0034] The image forming operation unit 33 shown in FIG. 1 shows an example having four inkjet heads 331 that respectively eject four colors of ink: yellow (Y), magenta (M), cyan (C), and black (K). The order of arrangement of the inkjet heads 331 is appropriately changed in an order that is preferable for image formation. The image forming operation unit 33 may also have inkjet heads that eject ink of other colors (including transparent ink) in addition to these four colors of ink. The image forming operation unit 33 uses, for example, ultraviolet-curable ink that changes phase between a sol state and a gel state due to a change in temperature and is fixed and cured by irradiation with ultraviolet rays. The inkjet head 331 has an ink heating unit 332 (FIG. 3) that keeps the ink in a sol state with an appropriate viscosity, an ejection drive unit 333 (FIG. 3) that applies a pressure change to eject the ink, and the like.

[0035] The fixing unit 34 fixes the ink that has landed on the recording material S by irradiating a fixing area with ultraviolet light. The fixing unit 34 includes an ultraviolet light irradiation unit 341 (FIG. 3). The light source of the ultraviolet light in the fixing unit 34 is not particularly limited, but may be, for example, an LED (light emitting diode) lamp that emits ultraviolet light.

[0036] The reading unit 35 captures and reads the image on the recording material S on which the ink has been fixed, and outputs a reading signal to the control unit 50 (FIG. 3). As the reading unit 35, for example, an imaging unit 351 (FIG. 3) having a line sensor is used. The line sensor is capable of capturing images across the width of the recording material S, and obtains a two-dimensional image by sequentially performing imaging operations as the recording material S is transported. A CCD sensor, a CMOS sensor, or the like can be used as each imaging element of the line sensor.

[0037] [Recording material ejection section] The recording material discharge section 40 places and holds the recording material S delivered from the transport section 31 until the user removes it. The recording material discharge section 40 includes a discharge tray 41 and guide rollers 42. The guide rollers 42 sandwich the recording material S delivered from the transport section 31 from above and below, transport it, and place it on the discharge tray 41. As with the loading tray 11, the discharge tray 41 may move up and down according to the total weight of the loaded recording material S, thereby reducing the amount of descent in the vertical direction of the recording material S sent by the guide rollers 42.

[0038] [Image forming device configuration] FIG. 3 is a block diagram showing the main configuration of the image forming apparatus 1. As shown in FIG. As shown in FIG. 3, the image forming apparatus 1 includes a control unit 50, a memory unit 61, an input / output interface 62, a display operation reception unit 63, a bus 69, a conveying motor 315, a first recording material heating unit 22, a second recording material heating unit 23, a temperature sensor 226 (temperature measurement unit), an ink heating unit 332, an ejection driving unit 333, an ultraviolet irradiation unit 341, an imaging unit 351, a pressure unit 26, and an air heating unit 80. The control unit 50 includes a main control unit 51, a transport control unit 52, a recording material heating control unit 53, a head control unit 54, a fixing control unit 55, a reading control unit 56, an air heating control unit 57, and a pressure control unit 58.

[0039] The main control unit 51 centrally controls the overall operation of the image forming apparatus 1. The main control unit 51 includes a CPU (Central Processing Unit) 511, a RAM (Random Access Memory) 512, and a ROM (Read Only Memory) 513. The CPU 511 performs various calculation processes and performs various control operations based on a control program or the like. The RAM 512 provides a working memory space for the CPU 511 and stores temporary data. The operation of the main control unit 51 (CPU 511) includes a process of appropriately processing image data acquired as a target for image formation and converting the image data into final data for driving the discharge driving unit 333.

[0040] The ROM 513 stores various control programs executed by the CPU 511, initial settings, etc. The ROM 513 may have a rewritable and updatable flash memory or the like. In this case, the ROM 513 can store not only the initial settings, but also updated or added control programs and setting data, etc. The setting data includes settings of the heating temperature by the first recording material heating unit 22 and the second recording material heating unit 23 according to the type (material) and thickness of the recording material, the air pressure by the pressure unit 26, and, if necessary, the conveying speed by the conveying unit 31. These setting data may be stored in a non-volatile memory of the storage unit 61, etc.

[0041] The transport control unit 52 controls the rotational operation of the transport motor 315, and performs control related to the transport state of the recording material S. The recording material heating control section 53 controls the outputs of the first recording material heating section 22 and the second recording material heating section 23 based on the measured temperature data (measurement results) input from the temperature sensor 226 and the like. The head control unit 54 controls the operation of the ink heating unit 332 and the ejection driving unit 333, and causes the ink to land at an appropriate position on the recording material S based on the image data. The fixing control unit 55 controls the operation of the ultraviolet ray irradiation unit 341 regarding the ultraviolet ray irradiation. The reading control unit 56 controls the operation of the imaging unit 351 . The air heating control section 57 controls the output of the air heating section 80, which will be described later. The pressurization control unit 58 controls the operation of the pressurization unit 26, thereby controlling the output of the pressurization unit 26, such as the air volume and air pressure.

[0042] The main control unit 51, the transport control unit 52, the recording material heating control unit 53, the head control unit 54, the fixing control unit 55, the reading control unit 56, the air heating control unit 57, and the pressure control unit 58 are connected to one another via a bus 69. The control operations of the control units constituting the control unit 50 may be centrally performed by each component of the main control unit 51. Furthermore, each component of the control unit 50 may have its own CPU or dedicated hardware circuit.

[0043] The storage unit 61 temporarily stores image data to be used for image formation and processed data thereof. The storage unit 61 is configured, for example, with a non-volatile memory. The input / output interface 62 controls communication between the image forming apparatus 1 and the outside in accordance with a communication standard. The input / output interface 62 includes, for example, a network card, and is capable of transmitting and receiving data to and from an external computer terminal, print server, etc. via a LAN (Local Area Network; which may include not only wired connection but also wireless LAN). Received data includes print jobs, that is, commands and settings related to image recording operations, and image data for image formation. Transmitted data includes status information of the image recording operations, etc.

[0044] The display operation reception unit 63 performs display operations on the display unit based on the control of the main control unit 51, and also receives input operations from the outside, converts them into signals, and outputs them to the main control unit 51. As the display unit, for example, a display device such as a liquid crystal display or an organic EL (Electro-Luminescence) display is used. To receive the input operations, a touch panel (touch sensor) or the like provided over the display unit is used. Furthermore, the display-related configuration may include an LED lamp or the like in addition to the display unit. Furthermore, the operation reception configuration may include a numeric keypad, push button switches, or the like in addition to the touch panel.

[0045] [Effects] According to the image forming apparatus 1 having the above-mentioned configuration, the heating section 20 has non-contact heating sections (the first recording material heating section 22 and the second recording material heating section 23). Therefore, the recording material S can be heated without being damaged by contact with the heating sections. Furthermore, the heating section 20 is provided with a pressure applying section 26 so that the air pressure inside the housing 21 can be increased. This makes it possible to prevent unheated air from entering the space between the non-contact first recording material heating section 22 and second recording material heating section 23 and the recording material S from outside the heating section 20. This makes it possible to prevent uneven heating of the recording material S caused by the inflow of air from the outside in the heating section 20, and improves the heating stability of the recording material S. Furthermore, since the outputs of the first recording material heating section 22 and the second recording material heating section 23 are controlled individually, the temperature of the image forming surface of the recording material S can be controlled more accurately.

[0046] 2. Second embodiment of image forming apparatus Next, a second embodiment of the image forming apparatus will be described. In the above-mentioned first embodiment, a configuration in which the entire air pressure inside the housing 21 is increased has been described, but the heating section of the image forming apparatus may be configured to increase the air pressure inside the housing 21 partially. Specifically, if the air pressure at the recording material inlet 24 inside the housing 21 is sufficiently high, it is possible to suppress air flowing into the housing 21 due to the conveyance of the recording material S. For this reason, as a second embodiment of the image forming apparatus, a configuration in which the air pressure at the recording material inlet 24 of the housing 21 is increased partially will be described. Note that in the second embodiment, a configuration similar to that of the above-mentioned first embodiment can be applied, except for the configuration related to the housing 21 and the pressure section 26. For this reason, detailed description of the configuration similar to that of the above-mentioned first embodiment will be omitted.

[0047] [Recording material heating section] Fig. 4 shows the heating unit 20 and a part of the image forming unit 30 corresponding to the image forming apparatus 1 shown in Fig. 1. In Fig. 4, only the image forming operation unit 33 and the support unit 321 are shown as the image forming unit 30. In the image forming apparatus 1, the configuration other than the heating unit 20 can be the same as that of the image forming apparatus 1 shown in Fig. 1.

[0048] 4 includes a housing 21, a first recording material heating section 22, a second recording material heating section 23, and a pressure section 26. The first recording material heating section 22 and the second recording material heating section 23 have the same configuration as in the first embodiment described above.

[0049] The housing 21 has a recording material feed-in port 24, a recording material discharge port 25, and a gas inlet 27 for supplying air 73 from the outside to the pressurizing unit 26. The gas inlet 27 has an opening at a position downstream in the conveying direction of the recording material S of the housing 21, farther away from the conveying path of the recording material S than the first recording material heating unit 22 and the second recording material heating unit 23. The gas inlet 27 is provided in two places inside the housing 21, on the image forming surface side and the back side of the recording material S.

[0050] The pressure applying section 26 is disposed within the housing 21 on the upstream side in the conveying direction of the recording material S relative to the first recording material heating section 22 and the second recording material heating section 23. Within the housing 21, the pressure applying section 26 is provided in two locations: a pressure applying section 26 (first pressure applying section) on the image forming surface side of the recording material S, and a pressure applying section 26 (second pressure applying section) on the back surface side. The pressurizing section 26 is disposed in a direction such that the air 72 introduced from the air inlet 27 is discharged toward the recording material carry-in opening 24 of the housing 21. This makes it possible to increase the air pressure inside the recording material carry-in opening 24 in the housing 21. Alternatively, the pressurizing section 26 sends air 75 from the inside of the recording material carry-in opening 24, the air 75 being equal to or greater than the air 71 that is caught in the transport of the recording material S and attempts to flow into the housing 21.

[0051] In this way, by discharging air 75 toward the recording material inlet 24 of the housing 21 by the pressure applying section 26, it is possible to prevent the air 71, which is caught in the conveyance of the recording material S, from flowing into the housing 21. As a result, it is possible to prevent a decrease in the uniformity of the in-plane temperature caused by the flow of air 71 into the heating section, and to sufficiently prevent a decrease in the heating stability of the recording material S in the heating section 20.

[0052] When the recording material S is conveyed into the housing 21, the air 75 discharged from the pressurizing section 26 (first pressurizing section) on the image forming surface side is blocked by the recording material S, making it difficult to send the air 75 from the installation side of the pressurizing section 26 (first pressurizing section) on the image forming surface side to the opposite side of the recording material S. For this reason, the pressurizing section 26 needs to be disposed on both the pressurizing section 26 (first pressurizing section) on the image forming surface side and the pressurizing section 26 (second pressurizing section) on the back surface side. The number of gas inlets 27 provided in the housing 21 is not particularly limited, and may be provided according to the number of pressurizing sections 26 installed, or may be provided in one location or in a number equal to or greater than the number of pressurizing sections 26 installed.

[0053] In addition, when the gas inlet 27 is located downstream of the first recording material heating section 22 and the second recording material heating section 23 in the conveying direction of the recording material S, the air 73 flowing from the gas inlet 27 flows as air 74 toward the pressurizing section 26 inside the housing 21. At this time, the air 74 flowing inside the housing 21 may come into contact with the first recording material heating section 22 and the second recording material heating section 23. In this case, the temperature of the first recording material heating section 22 and the second recording material heating section 23 is likely to be lowered by the air 74, and the stability of the heating temperature is likely to be reduced. For this reason, a shielding member 28 is provided between the air 74 flowing into the housing 21 from the gas inlet 27 and the first recording material heating section 22 and the second recording material heating section 23 to block the movement of the air 74. The shielding member 28 provides a flow path 29 through which the air 74 passes between the outer periphery of the housing 21 and the shielding member 28.

[0054] By providing the shielding member 28, it is possible to suppress contact between the air 74 flowing in from the gas inlet 27 and the first recording material heating section 22 and the second recording material heating section 23. As a result, it is possible to stabilize the temperatures of the first recording material heating section 22 and the second recording material heating section 23, and the heating stability of the recording material S is improved.

[0055] 3. Third embodiment of image forming apparatus Next, a third embodiment of the image forming apparatus will be described. The image forming apparatus of the third embodiment is configured to partially increase the air pressure inside the housing 21, similarly to the image forming apparatus of the second embodiment described above. Therefore, also in the image forming apparatus of the third embodiment, a configuration in which the air pressure at the recording material inlet 24 of the housing 21 is partially increased will be described. Note that, in the third embodiment, except for the configuration relating to the housing 21 and the pressure section 26, configurations similar to those of the first and second embodiments described above can be applied. Therefore, detailed description of configurations similar to those of the first and second embodiments described above will be omitted.

[0056] [Recording material heating section] Fig. 5 shows the heating unit 20 and a part of the image forming unit 30 corresponding to the image forming apparatus 1 shown in Fig. 1. Fig. 5 shows only the image forming operation unit 33 and the support unit 321 as the image forming unit 30. In the image forming apparatus 1, the configuration other than the heating unit 20 can be the same as that of the image forming apparatus 1 shown in Figs. 1 and 4.

[0057] 5 includes a housing 21, a first recording material heating section 22, a second recording material heating section 23, and a pressure section 26. The first recording material heating section 22 and the second recording material heating section 23 have the same configuration as in the first embodiment described above.

[0058] The pressure applying section 26 has the same configuration as that of the second embodiment described above. Therefore, the pressure applying section 26 is disposed in the housing 21 on the upstream side in the conveying direction of the recording material S than the first recording material heating section 22 and the second recording material heating section 23. The pressure applying section 26 is provided in two places, a pressure applying section 26 (first pressure applying section) on the image forming surface side of the recording material S and a pressure applying section 26 (second pressure applying section) on the back surface side. By discharging air 75 from the pressure applying section 26 toward the recording material inlet 24 of the housing 21, it is possible to suppress the inflow of air 71 caught in the conveyance of the recording material S into the housing 21. As a result, it is possible to suppress the decrease in the uniformity of the in-plane temperature due to the inflow of air 71 into the heating section, and to sufficiently suppress the decrease in the heating stability of the recording material S in the heating section 20.

[0059] The housing 21 has a recording material entrance 24, a recording material exit 25, and an air inlet 27 for supplying air 73 from the outside to the pressure unit 26. The air inlet 27 is provided at two locations, one on the top side and one on the bottom side of the housing 21. The air inlet 27 is provided upstream of the first recording material heating unit 22 and the second recording material heating unit 23 in the conveying direction of the recording material S, and downstream of the pressure unit 26. The top and bottom surfaces of the housing 21 are such that, in the heating unit 20, the image forming surface side of the recording material S is the top side of the housing 21, and the back side of the recording material S is the bottom side of the housing 21.

[0060] Furthermore, the housing 21 is provided with a flow path 29 through which air passes, from the gas inlet 27 through which external air 76 flows in, to a position where air 77 flows into the inside of the housing 21. In this manner, the gas inlet 27 is provided in a position separate from the recording material inlet 24 and the recording material outlet 25, and is provided in a position where air 77 can be sent to the pressurizing unit 26 via the flow path 29.

[0061] Further, an air heating unit 80 for heating the air passing through the flow path 29 is disposed within the flow path 29. The air heating unit 80 is not particularly limited as long as it has a configuration capable of heating the air within the flow path 29, and for example, a heating device such as a sheath heater, a carbon heater, or a cartridge heater can be applied. Furthermore, the air heating unit 80 does not have to be provided inside the flow path as long as it can heat the air passing through the flow path 29. For example, it may be a heating device or the like installed on the outer wall of the flow path 29.

[0062] By providing the air heating section 80 in the flow path 29, the air 76 flowing in from the outside of the housing 21 through the gas inlet 27 can be heated. Then, the air 77 heated by the air heating section 80 can be introduced into the housing 21. Usually, the temperature of the air 76 outside the housing 21 is lower than that inside the housing 21 where the first recording material heating section 22 and the second recording material heating section 23 are arranged. That is, if the low-temperature air 76 is introduced directly into the housing 21, the temperature of the first recording material heating section 22 and the second recording material heating section 23 is likely to decrease due to the air 76, and the stability of the heating temperature is likely to decrease. For this reason, with the above-mentioned configuration, the air 77 heated by the air heating section 80 can be introduced into the housing 21, and the decrease in the temperature of the air inside the housing 21 can be suppressed. As a result, the temperature of the first recording material heating section 22 and the second recording material heating section 23 is stabilized, and the heating stability of the recording material S is improved.

[0063] 4. Fourth embodiment of image forming apparatus Next, a fourth embodiment of the image forming apparatus will be described. In the above-described first embodiment, a configuration has been described in which the pressurizing unit 26 is provided inside the housing 21 to increase the overall air pressure inside the housing 21, but a configuration in which the overall air pressure inside the housing 21 is increased without using the pressurizing unit 26 may also be used. Specifically, by adjusting the opening areas of the recording material inlet 24 and the recording material outlet 25, it is possible to make the overall air pressure inside the housing 21 higher than the air that flows into the housing 21 due to the transport of the recording material S.

[0064] [Recording material heating section] Fig. 6 shows the heating section 20 and a part of the image forming section 30 corresponding to the image forming apparatus 1 shown in Fig. 1. Fig. 5 shows only the image forming operation section 33 and the support section 321 as the image forming section 30. In the image forming apparatus 1, the configuration other than the heating section 20 can be the same as that of the image forming apparatus 1 shown in Fig. 1.

[0065] 6 includes a housing 21, a first recording material heating section 22, and a second recording material heating section 23. The first recording material heating section 22 and the second recording material heating section 23 have the same configuration as in the first embodiment described above.

[0066] The housing 21 has a recording material entrance 24A provided at the upstream end (receiving end) in the conveying direction of the recording material S, and a recording material exit 25 provided at the downstream end (sending end). The recording material exit 25 is a slit-shaped opening through which the recording material S can pass, and has the same configuration as in the first embodiment described above.

[0067] The recording material entrance 24A is a slit-shaped opening that allows the recording material S to pass through, and has a larger opening area than the recording material discharge opening 25. By making the opening area of ​​the recording material entrance 24A larger than that of the recording material discharge opening 25, it is possible to increase the air pressure inside the housing 21 when the recording material S is transported to the housing 21. The principle by which the air pressure inside the housing 21 increases due to this difference in the opening area is presumed to be as follows.

[0068] 6, when the recording material S is transported into the housing 21, external air 71 attempts to flow into the housing 21 from the recording material inlet 24 so as to be caught in the transport of the recording material S. At this time, when the leading end of the recording material S enters the housing 21, the air 71 flows into the housing 21, and the air pressure inside the housing 21 temporarily increases.

[0069] The air inside the housing 21, whose pressure has temporarily increased, tries to flow out of the housing 21 where the air pressure is low. At this time, because there is a difference in the opening area between the recording material entrance 24A and the recording material discharge outlet 25, the air inside the housing 21 tends to flow out from the opening with the larger opening area through which the air can easily pass. In the housing 21 shown in Figure 6, the recording material entrance 24A has a larger opening area than the recording material discharge outlet 25, so more air 79 flows out from inside the housing 21 from the recording material entrance 24A side than from the recording material discharge outlet 25 side.

[0070] As a result, air 71 attempting to flow into the housing 21 following the leading edge of the recording material S collides with air 79 attempting to flow out of the housing 21. Then, when the temporary increase in air pressure in the housing 21 becomes higher than the pressure of air 71 attempting to flow into the housing 21 by the recording material S, air 71 cannot flow into the housing 21 and flows outside the housing 21 like air 78.

[0071] As described above, the housing 21 has a configuration in which the opening area of ​​the recording material entrance 24A is larger than the opening area of ​​the recording material exit 25, and this makes it possible to increase the air pressure inside the housing 21 when the recording material S is transported to the housing 21. This makes it possible to suppress the inflow of air 71, which is drawn in during the transport of the recording material S, into the housing 21. As a result, it is possible to suppress the decrease in the uniformity of the in-plane temperature caused by the inflow of air 72 into the heating section, and to sufficiently suppress the decrease in the heating stability of the recording material S in the heating section 20.

[0072] The present invention is not limited to the configurations described in the above-mentioned embodiments, and various modifications and variations are possible without departing from the scope of the present invention. [Explanation of symbols]

[0073] 1 image forming apparatus, 10 recording material supply section, 11 loading tray, 12 delivery roller, 20 heating section, 21 housing, 22 first recording material heating section, 23 second recording material heating section, 24, 24A recording material entrance, 25 recording material exit, 26 pressure section, 27 gas inlet, 28 shielding member, 29 flow path, 30 image forming section, 31 transport section, 33 image forming operation section, 34 fixing section, 35 reading section, 40 recording material exit section, 41 exit tray, 42 guide roller, 50 control section, 51 main control section, 52 transport control section, 53 recording material heating control section, 54 head control section, 55 fixing control section, 56 reading control section, 57 air heating control section, 58 pressure control section, 61 memory section, 62 input / output interface, 63 display operation reception section, 69 Bus, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 Air, 80 Air heating section, 226 Temperature sensor, 311 Conveyor belt, 312 Driving roller, 313 Driven roller, 315 Conveyor motor, 321 Support section, 322, 323 Support section, 331 Inkjet head, 332 Ink heating section, 333 Discharge driving section, 341 Ultraviolet irradiation section, 351 Imaging section, 511 CPU, 512 RAM, 513 ROM

Claims

1. a conveying section that conveys the recording material on a conveying path; an image forming unit that ejects ink onto the recording material being conveyed; a recording material heating section arranged upstream of the image forming section in a conveying direction of the recording material, the recording material heating section heating the recording material; a housing that covers the recording material heating unit and the transport path, and has a recording material inlet that is provided on the upstream side in the transport direction of the recording material and through which the recording material is transported, and a recording material outlet that is provided on the downstream side and through which the recording material is discharged; A pressurizing unit provided in the housing and configured to increase the air pressure in the housing; a gas inlet provided in the housing for supplying air to the pressurizing unit from outside the housing; Prepare Image forming device.

2. The recording material heating section has a non-contact heating device that heats the recording material without contacting the recording material. The image forming apparatus according to claim 1 .

3. A flow path for air to pass through is provided between the gas inlet and the pressurizing unit.

3. The image forming apparatus according to claim 1 or 2.

4. An air heating section for heating the air passing through the flow path is provided between the gas inlet and the pressurizing section. The image forming apparatus according to claim 3 .

5. a shielding member for shielding air flowing in from the gas inlet from contacting the recording material heating section between the flow path and the recording material heating section; 5. The image forming apparatus according to claim 3.

6. The pressure applying section blows air from inside the housing toward the recording material inlet.

6. The image forming apparatus according to claim 1.

7. The pressure applying section includes a first pressure applying section disposed on the image forming surface side of the recording material, and a second pressure applying section disposed on the opposite surface to the image forming surface.

7. The image forming apparatus according to claim 1.

8. A pressure control unit is provided for controlling the driving of the pressure unit, The pressure control unit controls an output of the pressure unit in accordance with a conveying speed of the recording material, and adjusts the air pressure inside the housing.

8. The image forming apparatus according to claim 1.

9. a conveying section that conveys a recording material; an image forming unit that ejects ink onto a conveyed recording material; a recording material heating section arranged upstream of the image forming section in a conveying direction of the recording material, the recording material heating section heating the recording material; a housing that covers the recording material heating unit and has a recording material inlet provided on the upstream side in the recording material conveying direction and a recording material outlet that is smaller in opening area than the recording material inlet provided on the downstream side Image forming device.

10. The recording material heating section includes a first recording material heating section disposed on an image forming surface of the recording material, and a second recording material heating section disposed on the opposite surface to the image forming surface.

10. The image forming apparatus according to claim 1.

11. a recording material heating control unit for controlling driving of the recording material heating unit, The recording material heating control section controls an output of the first recording material heating section and an output of the second recording material heating section independently of each other. The image forming apparatus according to claim 10.

12. A conveying section that conveys a recording material on a conveying path; an image forming unit that ejects ink onto the recording material being conveyed; a recording material heating section arranged upstream of the image forming section in a conveying direction of the recording material, the recording material heating section heating the recording material; a housing that covers the recording material heating unit and has a recording material inlet provided on the upstream side in a recording material conveying direction and a recording material outlet provided on the downstream side; A pressurizing unit provided in the housing and configured to increase the air pressure in the housing; The air conditioner includes a gas inlet provided in the housing for supplying air from outside the housing to the pressurizing unit, and an air heating unit provided between the gas inlet and the pressurizing unit for heating air passing through a flow path for air to pass through. Image forming device.

Images