JP2004181816A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus having a function for removing a deformation, e.g. creases, of a recording medium being produced when it is heated by means of a thermal fixing unit even in the case of a recording medium employing a heat-sensitive basic material, e.g. resin. <P>SOLUTION: The image forming apparatus comprises a press roller mechanism 58 for pressing the surface of a recording medium, under hot carrying state, against the outlet region of a thermal fixing unit HU. At least one roller 58c constituting the press roller mechanism is arranged to approach the surface of the recording medium or recede therefrom. The roller 58c presses the surface of the recording medium gravitationally. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus in which a sheet-shaped recording medium on which an image is formed by a printing unit is heated by a heating and fixing unit to fix the image on the recording medium.
[0002]
[Prior art]
As one of the conventional techniques in this field, a transparent base made of an acrylic resin, a polyester resin, or a urethane resin is used as a light-transmitting resin layer on a colored base layer also serving as a rust prevention layer formed on a metal substrate. After forming a resin layer and further applying a sublimation type coloring material by inkjet printing to an inkjet receiving layer using porous alumina or the like formed thereon, the sublimation type coloring material is heated in a heating furnace or hot press. By heating, the sublimation-type coloring material of the ink-jet receiving layer is sublimated into the transparent resin layer, and then the ink-jet receiving layer is removed to create a metal decorative body having a colored pattern formed on the transparent receiving layer. (For example, see Patent Document 1). Such an image forming technique can be applied to a recording medium having a metal having relatively low thermal deformation as a base material, but is applicable to a recording medium having a resin or the like having a large thermal deformation as a base material. Cannot avoid deformation of the substrate during heating, particularly generation of wrinkles.
[0003]
Further, as another conventional technique, a thermal transfer sheet on which a primary image is formed by an ink-jet printer or the like is superimposed on a recording sheet, and is heated at a temperature as uniform as possible by a temperature-controlled heat-pressing roller to perform thermal transfer. There is a type in which an image (ink) formed on a sheet is thermally sublimated and transferred to an ink fixing layer of a recording sheet (for example, see Patent Document 2). In this image forming technique, the surface temperature of the heat-pressing roller is strictly controlled, but the contact between the heat-pressing roller and the recording sheet is substantially linear contact, and the recording is performed at room temperature (room temperature). The surface of the sheet is pressed and heated in a moment and left at room temperature again.If a heat-sensitive material such as resin is used as the base material of the recording sheet, the wrinkles generated during heating will be cooled as it is. And it remains.
[0004]
Further, in order to heat and fix the recording sheet on which the sublimable ink has been transferred from the ink ribbon to the surface thereof, the recording sheet enters the heating box, and the recording sheet is opposed to the recording medium in the heating box by forming a slight gap. Heating the recording sheet by passing it between a pair of heating rollers or between a heating roller and a conveyance belt arranged along the partial peripheral surface thereof, immediately exits the heating box, and feeds the recording sheet. (See, for example, Patent Document 3). Also in this image forming technique, the recording sheet heated by the heating roller is immediately taken out of the heating box in a high temperature state at normal temperature, so that a heat-sensitive material such as resin is used as a base material of the recording sheet. The wrinkles generated at the time of heating are cooled and left as they are.
[0005]
Furthermore, in the field of textile printing technology, after applying a dye to the cloth whose wrinkles have been stretched by a wrinkle spreading roller by an ink jet method, the cloth is used to strengthen the dyeing and improve the color development. Some fabrics are sent to a heating device and passed through the heating device and immediately discharged to the outside (for example, see Patent Document 4). Even in this technology, there is no idea that wrinkles are removed by a wrinkle-stretching roller or the like at the end stage of the heating process. Wrinkles will remain.
[0006]
[Patent Document 1]
JP-A-10-297197 (paragraph number 0010-0013, FIG. 4)
[0007]
[Patent Document 2]
JP-A-10-16188 (paragraph number 0008-0012, FIG. 1)
[0008]
[Patent Document 3]
JP 2001-105638 A (Paragraph Nos. 0039-0058, FIG. 1)
[0009]
[Patent Document 4]
JP-A-08-317882 (Paragraph Nos. 0041-0043, 0061-0070, FIG. 2)
[0010]
[Problems to be solved by the invention]
In view of the above circumstances, the problem of the present invention is that even when a recording medium using a heat-sensitive material such as a resin as a base material is used, wrinkles or the like generated on the recording medium during heating by the heat fixing unit are used. An object of the present invention is to provide an image forming apparatus having a function of removing deformation before a recording medium is cooled.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the image forming apparatus according to the present invention, the image is fixed on the recording medium by heating a sheet-shaped recording medium on which an image is formed by a print unit by a heating and fixing unit. A pressure roller mechanism for pressing the surface of the recording medium in a heated and conveyed state to an exit area of the fixing unit is provided, and at least one roller constituting the pressure roller mechanism is movable in a distance direction with respect to the surface of the recording medium. It is configured.
[0012]
With this configuration, the deformation such as wrinkles generated on the surface of the recording medium in the heating process by the heating and fixing unit is extended by the pressing effect by the pressure roller mechanism against the recording medium in the heating temperature state at the final stage of the heating process, and is extended by the ironing effect. Will be. At this time, since at least one roller of the pressure roller mechanism is configured to be movable toward and away from the surface of the recording medium, it is possible to positively press the surface of the recording medium. As a result, the deformation such as wrinkles generated on the recording medium during the heating by the heating and fixing unit is extended before the recording medium is cooled. Will not be carried over to
[0013]
As a preferred embodiment of the present invention, if the roller that constitutes the pressure roller mechanism is configured to press the surface of the recording medium by its own weight by its own weight, it is related to the difference in the thickness of the recording medium. Thus, the pressing pressure can be reliably applied to the recording medium, and the pressing pressure can be adjusted by attaching a weight or the like to the corresponding roller. Of course, it is possible to apply a predetermined urging force by a spring or the like, but a configuration using only its own weight is the simplest and the lowest cost.
[0014]
As one of preferred embodiments according to the present invention, a curved conveyance section in which the surface on which the image of the recording medium is formed faces outward on the downstream side of the pressure roller mechanism with respect to the conveyance direction of the recording medium. Some are located. When the recording medium passes through such a curved transport section, a tensile force is generated on the decorative surface side on which an image is formed, and this force plays a role in extending fine surface wrinkles. Since a compressive force is generated on the back side of the decorative surface, it is not preferable as a measure against wrinkles. However, since the back side is usually not noticeable, the fine wrinkles hardly lower the commercial value.
[0015]
As described above, the deformation such as wrinkles generated on the surface of the recording medium during the heating process by the heating and fixing unit can be eliminated by the ironing effect by the pressure roller mechanism, but the recording medium suddenly starts from the heating and fixing unit. When the recording medium is discharged out of the apparatus, the recording medium may be rapidly cooled from the temperature in the heating and fixing unit to room temperature, which may generate new deformation such as wrinkles. In order to suppress the occurrence of new wrinkles or the like in the process of cooling the recording medium, in one of the preferred embodiments of the present invention, the recording medium is disposed downstream of the heating and fixing unit with respect to the transport direction of the recording medium. An annealing device is provided for gradually cooling the recording medium heated and fixed by the heating and fixing unit to a normal temperature level. As a result, the recording medium heated by the heating and fixing unit for heating and fixing the print image is gradually returned from the ink fixing temperature (generally 150 ° C. or higher) to normal temperature (room temperature) by the slow cooling device. Deformation such as wrinkles due to rapid cooling from the temperature inside the fixing unit (ink fixing temperature) to room temperature can be suppressed. Therefore, an optimum image forming apparatus is realized in which both the removal of wrinkles generated during heating and the prevention of new wrinkles that may occur during cooling are considered.
Other features and advantages according to the present invention will become apparent from the following description of embodiments with reference to the drawings.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
First, an example of a recording medium 1 handled by the image forming apparatus according to the present invention will be described with reference to FIG. The recording medium 1 is formed by forming a fixing layer 11 for ink, that is, an ink dye, with a urethane resin or the like on a surface of a base material 10 made of a film sheet such as PET (polyethylene terephthalate), and further penetrating the ink thereover. The surface layer 12 as a permeation layer is formed. When the surface of the substrate 10 has a property capable of fixing the ink dye, the fixing layer 11 can be omitted. An ink droplet is applied to the surface layer 12 of the recording medium 1 by an ink-jet printer or the like to form a print image by the print dots before sublimation, and then the surface layer 12 is applied to the surface layer 12 when heated to an appropriate temperature. The ink droplets (print dots before sublimation) start sublimation, and the ink droplets penetrate through the surface layer 12 so that the ink dye is sublimated and fixed on the fixing layer 11 as print dots after sublimation. Therefore, by peeling off the surface layer 12, a vivid image-recorded sheet having a very glossy feeling and having a printed image formed by print dots after sublimation on the fixing layer 11 is obtained as the final printed matter 100. That is, in this heating sublimation process, the ink dye applied to the surface layer 12 as the print dot before sublimation penetrates the surface layer 12 and reaches the fixing layer 11, where a print image is formed as the print dot after sublimation. In the recording medium 1, it is necessary to finally peel off the surface layer 12 from the fixing layer 11 or the base material 10. Therefore, it is convenient to provide an easy-release agent between them.
[0017]
An example of an image forming system for producing a final printed material 100 using such a recording medium 1 will be described with reference to FIGS. This image forming system includes a print station PS and an operating station OS as shown in FIG.
[0018]
The print station PS includes an ink jet type print unit PU, a loop forming unit RU for temporarily storing the recording medium 1 on which a print image is formed by the print dots before sublimation by the print unit PU, and is sent from the loop forming unit RU. A heat fixing unit HU for applying thermal energy to the recording medium 1 to create a print image formed by print dots after sublimation, and gradually cooling the recording medium 1 coming out of the heat fixing unit to a normal temperature (room temperature) level. Of the cooling unit CU. At this time, the loop forming unit RU disposed between the print unit PU and the heat fixing unit HU is configured such that the transport speed of the recording medium 1 in the heat fixing unit HU is lower than the average transport speed of the recording medium 1 in the print unit PU. Therefore, it serves the purpose of absorbing this speed difference. Note that the print unit PU, the loop forming unit RU, and the heat fixing unit HU are configured as units that can be separated from each other. The slow cooling unit CU is attached to the heat fixing unit HU.
[0019]
As is apparent from FIG. 4, in the print unit PU, the surface layer 12 which is a print surface is printed while rewinding the recording medium 1 wound in a roll shape stored in a roll sheet cartridge (not shown). The recording medium 1 is transported by the sheet transport mechanism 6 so as to come to the ink ejection port side of the ink jet print head 2 as a head. The print head 2 is supported by the head feed mechanism 3 so as to be able to reciprocate in a direction transverse to the transport direction of the recording medium 1, that is, in the main scanning direction. A print image is sequentially formed by transporting the recording medium 1 in the sub-scanning direction each time the print head 2 moves in the main scanning direction while discharging. A plurality of ejection port modules capable of ejecting different main colors to form a color print image are prepared in the print head 2. For example, when a photographic-quality color print image is required, normally, dark and light inks of the same color are used in addition to inks of cyan, magenta, yellow, and black. Since the print head 2 mounted on a general-purpose inkjet printer is used as the print head 2, further description is omitted here. The recording medium 1 having the print image formed on the surface layer 12 by the ink droplets 2a ejected from the print head 2 exits the print unit PU and enters the loop forming unit RU.
[0020]
The recording medium 1, which is originally a long sheet, needs to be cut in accordance with the size of a print image formed on the recording medium 1. In this embodiment, the sheet cutter means 5 is provided with a blade switchably provided between a position protruding toward the recording medium 1 with respect to the print head 2 and a position retracting in a direction away from the recording medium 1. A body 51 and a switching motor 52 for switching the position of the blade body 51 via a cam feed or a screw feed mechanism (not shown).
[0021]
Although only schematically shown in FIG. 3, the loop forming unit RU includes a turn roller 32 having three driven rollers 31 at a central position, and the loop forming unit RU is capable of performing a transport operation based on the turn roller 32. A first loop forming mechanism 30A, a second loop forming mechanism 30B on the lower side of the conveyance with reference to the turn roller 32, and a case 33 for receiving the recording medium 1 at a position below these.
[0022]
The turn roller 32 is driven by a motor (not shown), and presses the three driven rollers 31 against the outer periphery of the turn roller 32 so that the recording medium 1 is brought into contact with the turn roller 32 at a relatively large angle. It also functions so that the curl of the recording medium 1 can be removed by winding. The first loop forming mechanism 30A includes an introduction guide 34 for guiding the recording medium 1 discharged from the discharge port of the print unit PU downward, and the recording medium 1 guided downward by the introduction guide 34 further downward. It comprises a first fixed guide 35 for guiding, and a first movable guide 36 arranged opposite to the first fixed guide 35. The first movable guide 36 is swingable around a swing axis provided at an upper end thereof, and the first movable guide 36 is moved by a motor (not shown) in a closed posture shown by a solid line and by a virtual line. The swing is switched to the indicated open position.
[0023]
The second loop forming mechanism 30B includes a second fixed guide 37 for guiding the recording medium 1 sent from the first loop forming mechanism 30A via the turn roller 32 to the heating and fixing unit HU, and a second fixed guide. It comprises a second movable guide 38 arranged opposite to 37 and a pressure-supply type supply roller 39 for feeding the recording medium 1 to the heating and fixing unit HU. The second movable guide 38 is swingable around a swing axis provided at an upper end thereof, and the second movable guide 38 is moved by a motor (not shown) in a closed posture shown by a solid line and by a virtual line. The swing is switched to the indicated open position.
[0024]
In the loop forming unit RU, sensors (not shown) for determining the presence or absence of the recording medium 1 are arranged at various points on the transport path of the recording medium 1, and based on detection signals from these sensors. The control described below is executed. That is, when the recording medium 1 is ejected from the print unit PU, the first movable guide 36 is set to the closed posture and the turn roller 32 is rotated at a low speed to introduce the leading end of the recording medium 1. The guide is guided from the guide 34 to the turn roller 32. When it is confirmed that the leading end of the recording medium 1 is pressed and held by the turn roller 32 and the driven roller 31, the turn roller 32 is stopped, and then the first movable guide 36 is switched to the open position, and the recording medium 1 is stored in the space of the first loop forming mechanism 30A in a hanging manner. Next, when the rear end of the recording medium 1 sent from the print unit PU is detected, the drive of the turn roller 32 and the supply roller 39 is started in a state where the second movable guide 38 is set in the closed posture, and The leading end of the recording medium 1 is fed to the supply roller 39 of the second loop forming mechanism 30B, and the leading end of the recording medium 1 is pressed by the supply roller 39 at a speed equal to the transport speed of the recording medium 1 in the heating and fixing unit HU. After switching the second movable guide 38 to the open position while performing the operation of feeding the recording medium 1 into the heat fixing unit HU, the turn roller 32 is rotated at a high speed to remove the recording medium 1 stored in the first loop forming mechanism 30A into the second. Control for storing the recording medium 1 in a hanging manner in the space of the loop forming mechanism 30B is performed. As described above, when the recording medium 1 of the first loop forming mechanism 30A is sent out to the second loop forming mechanism 30B, the control for introducing the recording medium 1 from the print unit PU to the first loop forming mechanism 30A as described above. Is started.
[0025]
The heating and fixing unit HU schematically shown in FIG. 3 and shown in detail in FIG. 5 includes a heating case 51 made of a heat insulating material for heating the recording medium 1 inside a main body case 50. A heating case 51 is provided at a position above the heating case 51 so as to supply heated air to the heating case 51, and a supporting leg 53 for supporting the main body case 50. Inside the heating case 51, a preheating space PR is formed at the entrance side, and a heating space R is formed following the preheating space PR. In the preheating space PR and the heating space R, a heating and conveying mechanism 54 for conveying the recording medium 1 is arranged as a part of the sheet conveying mechanism 6. The heating / transporting mechanism 54 includes a pair of press-fit type introduction rollers 54a provided on the entrance side of the heating / fixing unit HU, and a rear surface of the recording medium 1 by two rollers in the heating space R. And a transport roller mechanism 54b for transporting the recording medium 1 while contacting the recording medium 1 with one roller, and disposed in the preheating space PR for contacting the lower surface of the recording medium 1 and transmitting heat to the recording medium 1. One guide member 54c and two guide members 54c arranged in the heating space R, and a plurality of upper surface contacts arranged at positions above the guide members 54c and in contact with the upper surface of the recording medium 1 to exert a conveying force. A roller 54d, a pressure roller mechanism 58 provided on the exit side of the heat fixing unit HU, and a curved transport section 59 provided immediately below the pressure roller mechanism 58 on the downstream side of the transport.
[0026]
As shown in FIGS. 6 and 7, the pressure roller mechanism 58 includes a first roller 58 a that contacts the back surface of the recording medium 1, and is disposed at a position on the upstream side of the first roller 58 a while conveying the recording medium 1. A second roller 58b that comes into contact with the surface, a third roller 58c that is located at a position lower than the first roller 58a in the conveyance direction and that comes into contact with the surface of the recording medium 1, and a roller shaft 58d of these rollers can be rotated. It is composed of a supporting bracket 58e. The roller shaft 58d of the third roller 58c is inserted into a vertical guide hole 58f provided in the bracket 58e, whereby the third roller 58c presses the recording medium 1 against the first roller 58a by its own weight. Will be. Each roller of the pressure roller mechanism 58 has a dimension longer than the maximum width of the recording medium 1 and employs a form in which a foamed resin is layered on the surface of a metal drum. The setting is such that pressing the recording medium 1 with the one roller 58a produces an ironing effect for extending wrinkles and the like generated on the recording medium 1 during heat fixing. The weight is determined experimentally and empirically according to the roller length, but the weight adjustment is performed by an additional weight. Of course, a configuration may be adopted in which a biasing force toward the recording medium 1 is forcibly applied to the third roller 58c by a spring or the like. As is apparent from FIG. 7, since the axis of the third roller 58c is shifted downward with respect to the axis of the first roller 58a in the transport direction, the recording medium 1 is slightly curved in this pressure-bonded area. Its ironing effect is further enhanced.
[0027]
Note that all the rollers constituting the heating and conveying mechanism 54 are driven directly or indirectly via a transmission belt (not shown). At this time, the third roller 58c is configured so that its roller shaft 58d moves toward and away from the recording medium 1, but can itself be driven by a well-known transmission mechanism having a tension adjusting pulley or the like. It is.
[0028]
The curved transport section 59 is formed of a guide body having a guide surface such that the surface of the recording medium 1 on which an image is formed faces outward. When the recording medium 1 moves while contacting such a surface of the guide body 59, a tensile force is generated on the surface side, and this force plays a role of extending fine surface wrinkles.
[0029]
A sheet heater 55 for heating the guide body 54c is provided on the lower surface side of the guide body 54c disposed below the upper contact roller 54d, and a fixing for measuring the temperature of the guide body 54c with respect to the center position of the sheet heater 55. A temperature sensor 41 is provided. If necessary, a sheet heater and a temperature sensor may be provided on the guide body constituting the curved conveyance section 59 to perform feedback temperature control.
[0030]
Inside the blower case 52, a plurality of rod-shaped electric heaters 56 and a cross flow fan for driving the fans around an axis parallel to the width direction of the recording medium 1 so as to send heated air. 57 are provided. On the lower surface side of the blower case 52, a discharge port E for heated air is formed at a position directly below the cross flow fan 57, and a suction port F is formed at a position on the conveyance path of the recording medium 1 in the heating conveyance mechanism 54 which is well conveyed. ing. An air temperature sensor 42 is arranged at the opening of the discharge port E so as to correspond to the cross flow fan 57.
[0031]
When the recording medium 1 is heated, by driving the electric heater 56 and the cross flow fan 57, the heating air heated inside the blower case 52 is discharged from the discharge port E to the recording medium 1 in the internal space of the heating case 51. The heated air is sent to the lower side position in the transport direction with a width exceeding the entire width of the recording medium 1 in the width direction, and the heated air flows in the heating space R toward the upper side of the transport along the transport path of the recording medium 1. Then, the heated air is circulated by sucking the air from the suction port F into the blower case 52 from the upper position in the transport direction of the recording medium 1, heating the electric heater 56, and supplying the heated air to the cross flow fan 57.
[0032]
At the time of the heating and fixing control, the electric power supplied to the corresponding electric heater 56 is controlled so that the temperature of about 180 ° C. is measured by the air temperature sensor 42, and the temperature of about 100 ° C. is measured by the fixing temperature sensor 41 in the preheating space PR. Then, the power supplied to the respective sheet heaters 55 is set such that the temperature of about 130 ° C. is measured by the upper conveyance temperature fixing sensor 41 in the heating space R, and the temperature of 180 ° C. is measured by the lower conveyance temperature sensor 41 in the heating space R. Controlled.
[0033]
As shown in FIGS. 5 and 6, the slow cooling unit 90 includes a slow cooling guide body 92 as a transport guide body for the recording medium 1, a slow cooling intermediate transport roller pair 94, a direction change guide 95, and a discharge roller pair 96. In addition to these, a slow cooling transport line for the recording medium 1 inclined downward is created. The slow cooling transfer line is disposed in a slow cooling space substantially closed by a slow cooling case 91. The slow cooling guide body 92 extends with a width exceeding the maximum width of the recording medium 1 in order to form an inclined guide surface which makes surface contact with the recording medium 1, and its inclination angle is 20 ° to 60 ° with respect to the vertical axis. ° to be determined. A heating wire 93 as a heater capable of transmitting heat to the slow cooling guide body 92 is provided on the back side of the slow cooling guide body 92.
[0034]
Further, the recording medium entrance area of the slow cooling guide body 92 is substantially equal to the exit temperature of the heating and fixing unit HU, and the recording medium discharge area of the slow cooling guide body 92 is substantially equal to room temperature. The heat transmitted from the heating wire 93 to the slow cooling guide member 92 is adjusted so that the temperature gradient in the meantime draws a curve as smoothly as possible, thereby suppressing deformation such as wrinkles generated in the recording medium 1 in the cooling process. be able to. For this reason, as shown in FIG. 8, the heating wire 93 is provided in the slow cooling guide body 92 such that the arrangement density is higher on the upper side of the conveyance and lower on the lower side of the conveyance. . In order to make the temperature gradient as smooth as possible, a meandering layout in which the arrangement pitch is continuously changed as shown in FIG. 9 may be adopted. In the embodiments of FIGS. 8 and 9, the heating wire 93 is constituted by a single wire, and by changing the amount of power supplied to the heating wire 93, the temperature generated in the slow cooling guide body 92 also rises and falls.
[0035]
By passing a predetermined current through the heating wire 93, a cooling temperature gradient that suppresses the generation of wrinkles as described above, for example, a temperature gradient from about 180 ° C. to 20 ° C. is created in the slow cooling guide body 92. The power supply control to the heating wire 93 is accurately performed by the controller 7 using the detection signal from the slow cooling temperature sensor 43 provided directly in the middle area of the slow cooling guide body 92 or above the guide surface as feedback.
[0036]
As an embodiment in which the temperature gradient in the transport direction in the slow cooling guide body 92 can be arbitrarily adjusted, for example, as shown in FIG. 10, the heating wire 93 is moved from the recording medium entrance area to the recording medium discharge area. .., The first heating wire 93a, the second heating wire 93b, the third heating wire 93c, the fourth heating wire 93d,..., And the power supply amount to each heating wire can be controlled independently. It is also possible to employ. In this case, a plurality of slow cooling temperature sensors 43a, 43b, 43c, 43d,... Are arranged at positions corresponding to the heating wires 93a, 93b, 93c, 93d,. Thereby, an arbitrary temperature gradient is created in the slow cooling guide body 92 as a whole. This configuration is particularly advantageous in the case where the fixing temperature greatly changes depending on the type of the recording medium 1 or the room temperature greatly changes depending on the season.
[0037]
A stocker ST is provided as shown in FIGS. 2 and 3 to receive the recording medium 1 discharged from the slow cooling unit CU. The stocker ST is formed in a box shape having a width wider than the maximum width of the recordable recording medium 1, and the inside thereof is lined with a sheet woven with conductive carbon fiber to remove static electricity. I have. Since the recording medium 1 discharged from the slow cooling unit TU has a certain degree of curl, the medium is wound up and stored in the stocker ST using the curl. Since the recording medium 1 wound up and stored has the ink (dye) forming the print image fixed on the fixing layer 11, the surface layer 12 is peeled off so that a final image having a beautifully colored image is obtained. The printed matter 100 is obtained.
[0038]
The controller 7 functioning as a control unit of the image forming system configured as described above includes a first controller 7A on the operating station OS side and a second controller 7B on the printing station PS side. They are interchangeably connected and can function as one controller.
[0039]
As shown in FIG. 2, the operating station OS includes a general-purpose computer 80, which also functions as the first controller 7A, a monitor 81, a keyboard 82, a mouse 83, and an image of the developed silver halide film F. A film scanner 85 that photoelectrically converts an image into color image data, and a data holding medium (CD, CD-R, or MO, and communication that includes not only a medium such as a compact flash and a smart media such as a semiconductor but also a data communication line). An image acquisition unit 84 (here, incorporated in the computer 80) for extracting color image data from media (including media) is provided. In this image forming system, the image data transferred to the first controller 7A through the film scanner 85 and the image acquisition unit 84 is subjected to various necessary image processings, and then sent to the second controller 7B as print data to be printed. At the station PS, a print image is formed on the recording medium 1 and is fixed by heating.
[0040]
The controller 7 includes a first controller 7A and a second controller 7B having a microcomputer system as a core member including a CPU, a ROM, a RAM, an I / O interface circuit, and the like. As shown in FIG. In one controller 7A, peripheral devices such as an image acquisition unit 84 and a film scanner 85 for sending image data are connected via an I / O interface circuit. In the second controller 7B, peripheral devices are connected via an I / O interface circuit. The peripheral devices incorporated in the print station PS, such as the inkjet print head 2, the head feed mechanism 3, the electric heater 56, the cross flow fan 57, and the recording medium transport mechanism, are connected. Further, a recording medium type detection sensor 44 for detecting an ID code given to a roll sheet cartridge or a shaft that winds and supports the recording medium 1 is also provided to send the detection signal to the controller 7. The controller 7 can recognize the type of the loaded recording medium 1 from the detection signal. The first controller 7A and the second controller 7B can transmit data via their respective communication modules. For example, image data subjected to image processing and correction processing in the first controller 7A is converted into final print data. After being transmitted to the second controller 7B via the communication modules 74a and 74b, it is used for applying sublimable ink to the recording medium 1 and the like.
[0041]
Each function by the controller 7 is created by hardware and / or software. However, if only functional elements related to the present invention are to be described, image data captured from the image acquisition unit 84 or the film scanner 85 will be described. An image data input unit 71 that performs pre-processing such as format conversion and resolution conversion on the image data, and an image processing unit 72 that performs image correction processing such as trimming and color correction on the image data transferred from the image data input unit 71 A print data generating unit 73 that generates print data for the print head 2 from the final image data that has been subjected to image processing by using a binarization method such as error diffusion, based on the transferred print data. A print control unit 7 for driving the print head 2 to discharge ink droplets from the ejection openings , Intermittent feeding of the recording medium 1 in synchronization with the movement of the print head 2 in the main scanning direction in the printing unit PU, loop conveyance of the recording medium 1 in the loop forming unit RU, and recording medium in the heat fixing unit HU. 1, a transport control section 76 for controlling the heating and transporting of the recording medium 1 from inside the slow cooling unit CU (by the slow cooling intermediate transport roller pair 94 and the discharge roller pair 96), the electric heater 56 of the heat fixing unit HU, The heating control unit 77 for controlling the drive of the cross flow fan 57 and the supply of power to the heating wire 93 (93a...) As a heater for the slow cooling guide body 92 are detected by the slow cooling temperature sensors 43 (43a...). The slow cooling control unit 78, which controls based on the temperature, obtains the type information of the loaded recording medium 1 from the ID code read by the recording medium type detection sensor 44. Such as the recording medium type determining unit 79 which are representative. The slow cooling control unit 78 controls the power supply to the heating wires 93 (93a...) By taking into account information such as the type of the recording medium to be used and the room temperature by the recording medium type determining unit 79 as necessary. be able to.
[0042]
A typical work flow for producing a final print using such an image forming system will be described below.
1. Print Image Forming Step First, JPEG format image data read from the MO disk using the image acquisition unit 84 is transferred to the image data input unit 71 as an image source of the image forming apparatus. The JPEG image data is expanded into 8-bit RGB color image data by the image data input unit 71 and sent to the image processing unit 72. Next, the image data is processed based on the print image size, the trimming setting command, and the color correction command input by the operator operating the keyboard 82 and the mouse 83. When the predetermined image processing is completed, the image data is sent to the print data generation unit 73. Since the RGB color image data is converted into CMYK color image data at an appropriate stage before and after other image processing in the image processing unit 72, the color image data sent to the print data generation unit 73 is CMYK color image data. It is. The print data generation unit 73 converts the CMYK color image data into binary CMYK print data, and transfers it to the print control unit 75. As described above, the print control unit 75 generates a drive pulse signal for the print head 2 from the transferred binary CMYK print data, thereby controlling the drive elements of the print head 2 to control the recording medium 1. To form an image with ink dots.
[0043]
2. The recording medium 1 on which an image is formed on the surface layer 12 at the image fixing formation stage passes through a preheating space PR and a heating space R, which are appropriately temperature-controlled, after being subjected to necessary time adjustment in the loop forming unit RU. Thus, heat energy is received, and the image formed on the surface layer 12 by the heat sublimation generated at that time is transferred (fixed) to the fixing layer 11. The recording medium 1 that has undergone the heat-fixing process has its wrinkles generated in the heating process stretched by the pressing effect of a pressure applying roller mechanism 58 disposed at the outlet of the heat-fixing unit HU as a pressure applying means, and further has a curved conveying unit. While the surface is pulled and shaped by 59, it is sent into the slow cooling unit CU.
[0044]
3. The recording medium 1 sent to the recording medium slow cooling stage slow cooling unit CU descends obliquely downward along the surface of the slow cooling guide body 92, is sandwiched by the slow cooling intermediate conveyance roller pair 94, It is returned to a nearly horizontal position by the direction change guide 95 and the pair of discharge rollers 96 arranged below, and is discharged outside. The discharged recording medium 1 is stored in the stocker ST, and the surface layer 12 is peeled off in a timely manner to obtain a final printed matter 100 having a beautifully colored image.
[0045]
In the above-described embodiment, an image forming system including the print station PS and the operating station OS, in which the print station PS includes the print unit PU, the loop forming unit RU, the heat fixing unit HU, and the slow cooling unit CU, will be described. Although described, the minimum components of the image forming apparatus according to the present invention are the heat fixing unit HU and the slow cooling unit CU. Of course, a unit including all other units or a unit partially including other units can be handled as the image forming apparatus.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of a recording medium handled by the present invention. FIG. 2 is an external view illustrating an embodiment of an image forming apparatus according to the present invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration of a print station. FIG. 4 is a schematic cross-sectional view showing a configuration of a print unit. FIG. 5 is a schematic cross-sectional view showing a configuration of a heat fixing unit and a slow cooling unit. FIG. 6 is an enlarged schematic cross-sectional view showing a configuration of a pressure roller mechanism. FIG. 8 is a schematic view showing a layout of a heating wire provided on a cold guide body. FIG. 8 is a perspective view showing a configuration of a pressure roller mechanism and a slow cooling unit. FIG. 9 is another layout of a heating wire provided on a slow cooling guide body. FIG. 10 is a schematic diagram showing a layout of another embodiment of a heating wire provided in a slow cooling guide body. FIG. 11 is a functional block diagram illustrating functions of a controller.
Reference Signs List 1 recording medium 6 transport mechanism 7 controller 7A first controller 7B second controller 58 pressure roller mechanism 59 curved transport section 76 transport control section 77 heating control section 78 slow cooling control section 79 recording medium type determination section 91 slow cooling case 92 Slow cooling guide 93 Heating wire (heater)
94 Slowly cooled intermediate transport roller 95 Direction change guide 96 Discharge roller PU Print unit RU Loop forming unit HU Heat fixing unit CU Slowly cooled unit

Claims (4)

An image forming apparatus that fixes the image on the recording medium by heating the sheet-shaped recording medium on which an image is formed by a print unit by a heating and fixing unit,
A pressure roller mechanism for pressing a surface of the recording medium in a heated and conveyed state to an exit area of the heat fixing unit, wherein at least one roller included in the pressure roller mechanism moves far and near with respect to the surface of the recording medium; An image forming apparatus, which is configured to be capable of being used. 2. The image forming apparatus according to claim 1, wherein the movable roller is configured to press the surface of the recording medium by its own weight. 2. A curved conveying section having a surface on a side on which an image of the recording medium is formed facing outward is disposed downstream of the pressure roller mechanism with respect to a conveying direction of the recording medium. Or the image forming apparatus according to 2. A gradual cooling device that gradually cools the recording medium that has been heated and fixed by the heating and fixing unit to a normal temperature level is disposed downstream of the heating and fixing unit with respect to the transport direction of the recording medium. The image forming apparatus according to claim 1.

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