JP2008080579A - Image forming apparatus and image fixation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image fixation method whereby an image of a good quality can be recorded and saving of energy can be attained. <P>SOLUTION: The inkjet recorder which can selectively carry out single-sided recording and double-sided recording is constituted to be able to separately control temperatures of fixing rollers which carry out fixation processing of the image. Fixation processing is carried out by controlling the temperatures of the fixing rollers to a temperature set for single-sided recording when single-sided recording is carried out, and to a temperature set for double-sided recording when double-sided recording is carried out. Fixation processing can be carried out while the temperatures of the fixing rollers are set to optimum temperatures according to a single-sided/double-sided recording method. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image fixing method, and more particularly to an image forming apparatus and an image fixing method capable of selectively performing single-sided recording and double-sided recording.

  In general, in an image forming apparatus such as an ink jet recording apparatus, as a drawing ink, a dye-based ink in which a dye is dissolved in an aqueous or non-aqueous solvent, or a pigment-based ink in which a pigment is dispersed in an aqueous or non-aqueous solvent, An ink or the like in which colored particles in which a coloring material such as a pigment or a dye and a resin are combined is dispersed in a solvent is used.

  The fixing of the image after drawing in the dye-based ink and the pigment-based ink is performed by evaporation of the ink solvent or penetration into the recording medium.

  However, when coated paper or film is used as the recording medium, since the penetration effect cannot be expected, a heat fixing method is used in which evaporation of the solvent is accelerated by applying heat after drawing to fix the image. .

  Also, in fixing an image after drawing with ink in which colored particles are dispersed in a solvent, by applying heat after drawing, the resin combined with the coloring material is fused on the recording medium, and the image is printed. A heat fixing method for fixing is used.

  In such a heat fixing system, a configuration in which heat and pressure are applied by a roller pair or a belt pair having an internal heat source is adopted from the viewpoint of good thermal efficiency, ease of handling, and ease of device configuration. (See Patent Documents 1 to 5).

  By the way, in an inkjet recording apparatus capable of selectively performing single-sided recording and double-sided recording, when fixing processing is performed using such a roller pair or belt pair, conventionally, fixing is performed under the same conditions during both-side recording and one-side recording. We were processing. That is, the fixing process is performed by setting the roller pair or the belt pair to the same temperature during both-side recording and one-side recording.

Conventionally, when performing double-sided recording, fixing processing is performed after completion of single-sided recording and after completion of double-sided recording. That is, after recording the front side, the fixing process is once performed in the fixing unit, and then the recording process on the back side is performed. After the recording on the back side is completed, the fixing process is performed again in the fixing unit.
JP-A-2005-67170 JP 2002-229276 A JP 2002-149004 A JP 2002-307759 A JP-A-8-248808

  However, the total amount of heat required and the required degree of heating of the back surface are different between the double-sided recording and the single-sided recording, and there is a disadvantage that energy is wasted if the fixing process is performed under the same conditions. .

  In addition, when performing double-sided recording, if the fixing process is performed after completion of single-sided recording and after completion of double-sided recording, there is a problem in that front and back recording deviation occurs and quality deteriorates. That is, when the fixing process is performed, the recording medium may be deformed, and when an image is recorded on the deformed recording medium, there is a problem that recording deviation occurs on the front and back of the recording medium.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus and an image fixing method capable of recording an image of good quality and saving energy.

  The invention according to claim 1 is an image forming apparatus capable of selectively performing single-sided recording and double-sided recording in order to achieve the object, and a pair of recording media on which images are recorded by a recording unit. In an image forming apparatus having a fixing unit that fixes a recorded image by heating and pressurizing between rollers or between belts, a heating unit that individually heats the pair of rollers or belts, and one-side recording The heating means is controlled so that the temperature of the pair of rollers or belts is set in advance for single-sided recording, and the temperature of the pair of rollers or belts for double-sided recording in advance during double-sided recording. There is provided an image forming apparatus comprising: a control unit that controls the heating unit so as to have a set temperature.

  According to the first aspect of the invention, the temperature for double-sided recording and the temperature for single-sided recording are set in advance. At the time of double-sided recording, the temperature for double-sided recording is used. At the time of single-sided recording, the temperature for single-sided recording is used. The roller or belt is heated to perform a fixing process. As a result, the temperature of the roller or belt is set to an optimum temperature, for example, a temperature necessary and sufficient for fixing an image recorded by the single-sided / double-sided method in each of double-sided recording and single-sided recording. Processing can be performed.

  In order to achieve the above object, according to a second aspect of the present invention, during single-sided recording, the temperature of the roller or belt that contacts the image is higher than the temperature of the roller or belt that does not contact the image. The temperature for single-sided recording is set, and the temperature for double-sided recording is set so that the temperature of both rollers or belts is substantially the same during double-sided recording. An image forming apparatus according to 1 is provided.

  According to the invention of claim 2, during single-sided recording, the temperature for single-sided recording is such that the temperature of the roller or belt that contacts the image is higher than the temperature of the roller or belt that does not contact the image. Is set, and during double-sided recording, the temperature for double-sided recording is set so that the temperatures of both rollers or belts are substantially the same. Thereby, energy saving can be aimed at. That is, at the time of single-sided recording, it is not necessary to make the temperature of both rollers or belts the same, so only the roller or belt that contacts the image is heated to the required temperature. As a result, energy can be actively saved.

  According to a third aspect of the present invention, in order to achieve the above object, after recording an image on both sides of the recording medium during double-sided recording, the recording medium is passed between the pair of rollers or a belt. An image forming apparatus according to claim 1 or 2 is provided.

  According to the invention of claim 3, in the case of duplex recording, the image fixing process is performed after the images are recorded on both surfaces of the recording medium. That is, even if the recording on one side is completed, the fixing process is not performed at this stage, and the fixing process is performed when recording on both sides is completed. Thereby, it is possible to prevent the recording deviation from occurring on the front and back sides of the recording medium, and it is possible to record an image of good quality. In other words, when the fixing process is performed, the recording medium may be deformed. When the fixing process is performed after the single-sided recording is completed, the recording medium may be deformed, and an image recorded on the back surface may be misaligned. However, this can be prevented by performing a fixing process after completion of double-sided recording.

  According to a fourth aspect of the present invention, in order to achieve the above object, a detecting means for detecting a type of the recording medium, and a temperature for the single-sided recording according to the type of the recording medium detected by the detecting means, The image forming apparatus according to claim 1, further comprising a setting unit configured to set the temperature for the duplex recording.

  According to the invention of claim 4, the type of the recording medium is detected by the detecting means, and the temperature for single-sided recording and the temperature for double-sided recording are set by the setting means according to the type of recording medium detected by the detecting means. Set automatically. Thereby, the temperature of a roller or a belt can be set to a more optimal temperature. That is, the temperature for single-sided recording and the temperature for double-sided recording differ depending on the recording medium, and can be set to an optimum temperature according to each recording medium. Thereby, further energy saving can be aimed at.

  In order to achieve the above object, the recording unit includes an intermediate transfer member and an ink discharge unit that discharges ink to form an image on the intermediate transfer member. The image forming apparatus according to claim 1, wherein the image formed on the intermediate transfer member is transferred to the recording medium to form an image on the recording medium.

  According to the fifth aspect of the invention, a so-called intermediate transfer method is employed as a recording method in the recording unit. That is, ink is ejected from the ink ejection means to form an image on the intermediate transfer member, and the image formed on the intermediate transfer member is transferred to the recording medium to form an image on the recording medium. As described above, in an image forming apparatus that employs an intermediate transfer method as a recording method in a recording unit, by providing a fixing process downstream of the transfer process, the abrasion resistance of an image (transfer image) transferred onto a recording medium is improved. It becomes possible to secure.

  According to a sixth aspect of the present invention, in order to achieve the above object, the recording unit applies the processing liquid having an action of insolubilizing or aggregating the color material in the ink before the ink is ejected by the ink ejection unit. A treatment liquid applying means for applying to the transfer body; and a solvent absorbing means for absorbing and removing excess solvent of the ink ejected by the ink discharge means from the intermediate transfer body before transferring the image onto the recording medium. An image forming apparatus according to claim 5 is provided.

  According to the invention of claim 6, in the image forming apparatus according to claim 5, which employs an intermediate transfer system as a recording system, the recording unit is further provided with a treatment liquid applying unit and a solvent absorbing unit. The treatment liquid application unit applies a treatment liquid having an action of insolubilizing or aggregating the color material in the ink onto the intermediate transfer body before the ink is ejected by the ink discharge unit. By applying this treatment liquid, the ink deposited on the intermediate transfer member is insolubilized or aggregated after the droplets are deposited. Then, the excess solvent of the ink in which the coloring material is insolubilized or aggregated is absorbed and removed from the intermediate transfer member by the solvent absorbing unit before the image is transferred to the recording medium. In this way, the colorant in the ink deposited on the intermediate transfer member is insolubilized or aggregated, and after removing the excess solvent, it is transferred onto the recording medium, so that moisture absorbed by the recording medium at the time of transfer can be reduced. This can limit the deformation of the recording medium. Thereby, an image of good quality can be recorded.

  According to a seventh aspect of the invention, in order to achieve the object, the ink or the treatment liquid contains polymer fine particles having a glass transition temperature Tg of 30 ° C. or higher, while the roller or belt has a temperature of 30 ° C. The image forming apparatus according to claim 1, wherein the image forming apparatus is set as described above.

  According to the seventh aspect of the present invention, polymer fine particles having a glass transition temperature Tg of 30 ° C. or higher are contained in the ink or processing liquid, and the temperature of the roller or belt is set to 30 ° C. or higher. By containing polymer fine particles having a glass transition temperature Tg of 30 ° C. or higher in the ink or the treatment liquid, the abrasion resistance is ensured by heating and pressurizing in the fixing unit. Further, by defining the temperature of the roller or belt at 30 ° C. or higher, it is possible to ensure the ejection reliability during ejection.

  According to an eighth aspect of the present invention, in order to achieve the above object, the recorded image is recorded by heating and pressurizing the recording medium on which the image is recorded between a pair of rollers or belts that are pressed against each other. In the image fixing method for fixing, the temperature of the pair of rollers or belt when processing a recording medium having an image recorded on one side, and the pair of rollers or processing when processing a recording medium having an image recorded on both sides Provided is an image fixing method characterized by individually setting a belt temperature.

  According to the invention of claim 8, when processing a recording medium having an image recorded on one side, the pair of rollers or the belt is heated at a temperature set for single-sided recording, and the image is recorded on both sides. When processing a recording medium, a pair of rollers or belts is heated at a temperature set for double-sided recording. As a result, the temperature of the roller or belt is set to an optimum temperature, for example, a temperature necessary and sufficient for fixing an image recorded by the single-sided / double-sided method in each of double-sided recording and single-sided recording. Processing can be performed.

  According to the image forming apparatus and the image fixing method of the present invention, it is possible to record a good quality image and save energy.

  The best mode for carrying out the image forming apparatus and the image fixing method according to the present invention will be described below.

  FIG. 1 is a schematic diagram showing a schematic configuration of an ink jet recording apparatus to which the present invention is applied.

  The ink jet recording apparatus 10 is an ink jet recording apparatus capable of selectively performing single-sided recording and double-sided recording on a recording sheet 12 as a recording medium, and mainly includes a paper feeding unit 14, a recording unit 16, a reversing unit 18, and fixing. Part 20.

  During single-sided recording, the recording paper 12 fed from the paper feed unit 14 is conveyed to the recording unit 16 to form an image on the surface, and then conveyed to the fixing unit 20 for fixing processing.

  At the time of double-sided recording, the recording paper 12 fed from the paper feeding unit 14 is conveyed to the recording unit 16 to form an image on the surface, and then conveyed to the reversing unit 18 to reverse the front and back. Then, the recording paper 12 whose front and back sides are reversed is conveyed again to the recording unit 16 to form an image on the back surface, and then conveyed to the fixing unit 20 for fixing processing.

  The paper feed unit 14 has a tray (not shown) for storing the recording paper 12, and feeds the recording paper 12 stored in the tray one by one to the paper feed conveyance path 22 by a paper feed mechanism (not shown). To do. Alternatively, the roll paper is cut into a predetermined length and fed one by one to the paper feeding conveyance path 22.

  The paper feed conveyance path 22 includes an inclined first paper feed conveyance path 22A and a horizontal second paper feed conveyance path B, and is formed by, for example, a roller or a belt. The recording paper 12 fed from the paper feed unit 14 is transported from the first paper feed transport path 22A to the second paper feed transport path B, and is transported horizontally to the recording unit 16.

  The recording unit 16 forms an image on the recording paper 12 by a so-called intermediate transfer method. That is, an image is once formed on the intermediate transfer member, and the image formed on the intermediate transfer member is transferred to the recording paper 12 to form a predetermined image on the recording paper 12.

  The recording unit 16 forms an image on the intermediate transfer member by a so-called two-component reaction method. That is, on the intermediate transfer member, an ink containing a solvent-insoluble material such as a coloring material in the ink, such as a pigment ink, and a treatment liquid that has a function of aggregating the solvent-insoluble material in the ink. An image is formed on. By forming an image on the intermediate transfer member using such ink and processing liquid, it is possible to prevent landing interference between ink droplets ejected on the intermediate transfer member, and to produce a high-quality image on the intermediate transfer member. Can be formed.

  The recording unit 16 includes an intermediate transfer member 24, a treatment liquid supply unit 26 that applies the treatment liquid (P) to the surface (recording surface) of the intermediate transfer member 24, and an intermediate transfer that is provided with the treatment liquid (P). An image forming unit 28 for forming an image by ejecting cyan (C), magenta (M), yellow (Y), and black (K) inks onto the recording surface of the body 24, and recording on the intermediate transfer body 24 A solvent removing unit 30 that removes excess solvent of the ink ejected on the surface, and a transfer unit 32 that transfers an image formed on the recording surface of the intermediate transfer body 24 to the recording surface of the recording paper 12. Yes.

  The intermediate transfer member 24 is composed of an endless belt having a predetermined width (at least equal to or greater than the width of the recording paper 12). The intermediate transfer member 24 is wound around three rollers 34A to 34C arranged at predetermined positions, and is guided by the three rollers 34A to 34C to travel on a predetermined traveling path.

  The three rollers 34A to 34C are respectively arranged at predetermined positions so as to form an inverted triangular traveling path, and an intermediate transfer member drive motor (not shown) is connected to one of them. The intermediate transfer member 24 is driven at a predetermined speed in an arrow direction (counterclockwise direction) in the figure by driving this intermediate transfer member drive motor.

  The processing liquid supply unit 26 includes a recording head (hereinafter referred to as “processing liquid head”) 36P that discharges the processing liquid (P), and the processing liquid head 36P is directed toward the recording surface of the intermediate transfer member 24. By discharging the processing liquid (P), the processing liquid (P) is applied onto the recording surface of the intermediate transfer member 24. The processing liquid head 36P is a so-called full-line head, and has a large number of nozzles across the width of the intermediate transfer member 24 on the surface (ejection surface) facing the recording surface of the intermediate transfer member 24 ( Details will be described later). The intermediate transfer member 24 discharges the processing liquid (P) from each nozzle of the processing liquid head 36P in the process of passing under the processing liquid head 36P, and the processing liquid (P) having a predetermined thickness is formed on the recording surface. P).

  As the treatment liquid discharged from the treatment liquid head 36P, a treatment liquid having a function of reacting with the ink and aggregating the solvent-insoluble material in the ink is used.

  The image forming unit 28 is a recording head (hereinafter referred to as “ink head”) 36C, 36M, 36Y, 36K that ejects ink of each color of cyan (C), magenta (M), yellow (Y), and black (K). A predetermined image is formed on the recording surface of the intermediate transfer member 24 by ejecting ink of each color from the ink heads 36C, 36M, 36Y, and 36K toward the intermediate transfer member 24. The ink heads 36C, 36M, 36Y, and 36K are also composed of full-line heads similarly to the processing liquid head 36P, and each intermediate transfer member has a surface (discharge surface) that faces the recording surface of the intermediate transfer member 24. A number of nozzles are provided across 24 width directions. The intermediate transfer member 24 ejects ink of the corresponding color from each of the ink heads 36C, 36M, 36Y, 36K in the process of passing under the ink heads 36C, 36M, 36Y, 36K of the image forming unit 28. Thus, a predetermined image is formed on the recording surface.

  The ink ejected from the ink heads 36C, 36M, 36Y, and 36K is an ink containing a solvent-insoluble material such as a color material in an ink such as a pigment ink. When this ink lands on the recording surface of the intermediate transfer member 24, it reacts with the treatment liquid previously applied to the recording surface, and solvent-insoluble materials such as coloring materials are aggregated. Thereby, landing interference between ink droplets can be prevented, and a high-quality image can be formed on the recording surface of the intermediate transfer member 24.

  Here, the ink heads 36C, 36M, 36Y, and 36K that eject inks of cyan (C), magenta (M), yellow (Y), and black (K), and the processing liquid that ejects the processing liquid. The configuration of the head 36P will be described.

  Since the ink heads 36C, 36M, 36Y, and 36K and the treatment liquid head 36P have the same configuration, the configuration of the recording head 36 will be described here.

  FIG. 2 is a plan view showing the ejection surface of the recording head 36. 3 is a cross-sectional view of the recording head 36 shown in FIG. 2 taken along line 3-3. Note that the longitudinal direction of the head 36 in FIG. 2 (head longitudinal direction) corresponds to the front and back direction in FIG.

  As described above, the recording head 36 of the present embodiment is a full line head, and the ejection surface thereof has a length corresponding to the maximum recording width of an image formed on the recording surface of the intermediate transfer member 24. A number of discharge ports (nozzles) 1 are formed.

  As shown in FIG. 2, the nozzles 1 are arranged in a two-dimensional shape (matrix shape) along the head longitudinal direction and an oblique direction not orthogonal to the head longitudinal direction. A high resolution image can be formed on the recording surface of the intermediate transfer member 24.

  As shown in FIG. 3, the recording head 36 is provided with a pressure chamber 2 communicating with the nozzle 1 for each nozzle 1. A supply port 4 is formed at one end of the pressure chamber 2, and the pressure chamber 2 communicates with the common flow path 5 through the supply port 4. A predetermined liquid (treatment liquid or each color ink) is stored in the common flow path 5, and the liquid is supplied from the common flow path 5 to the pressure chamber 2.

  One wall surface (upper surface in FIG. 3) of the pressure chamber 2 is constituted by a diaphragm 6, and a piezoelectric element 8 is provided at a position corresponding to the pressure chamber 2 on the diaphragm 6. An individual electrode 7 is provided on the upper surface of the piezoelectric element 8. In this embodiment, the diaphragm 6 is made of a conductive material and also serves as a common electrode for the piezoelectric element 8.

  With the above configuration, when a driving voltage is applied to the piezoelectric element 8, the liquid in the pressure chamber 2 is pressurized according to the displacement of the piezoelectric element 8, and a droplet is ejected from the nozzle 1. After discharge, the liquid is supplied from the common flow path 5 to the pressure chamber 2.

  In the above example, the piezoelectric recording head that discharges using the piezoelectric element 8 is illustrated. However, the present invention is not limited to this, for example, electrothermal conversion represented by a heater. You may use the thermal recording head which discharges using an element, and various other recording heads.

  The solvent removing unit 30 brings a solvent absorbing roller 38 made of a porous material into contact with the recording surface of the intermediate transfer member 24 from which the ink has been ejected by the image forming unit 28, and removes excess solvent of the ink ejected on the recording surface. Absorb and remove.

  The solvent absorbing roller 38 is provided so as to be movable back and forth with respect to the roller 34A, and is driven by a solvent absorbing roller driving means (not shown) to move forward and backward between a pressure position and a release position. Then, the intermediate transfer member 24 is pressed against the intermediate transfer member 24 wound around the roller 34A by moving to the pressurizing position, and is separated from the intermediate transfer member 24 by moving to the release position.

  In addition, a solvent absorption pump 42 is connected to the solvent absorption roller 38 via a drain tube 40. By driving the solvent absorption pump 42, excess solvent is absorbed from the surface. Excess solvent absorbed from the surface of the solvent absorbing roller 38 is guided to the drainage tube 40 through the inside of the solvent absorbing roller 38 and stored in the drainage tank 44 via the drainage tube 40.

  In the course of passing through the solvent removing unit 30, the intermediate transfer member 24 is pressed against the recording surface by the solvent absorbing roller 38, and excess solvent is removed by suction.

  The transfer unit 32 conveys the recording sheet 12 while pressing the recording sheet 12 against the intermediate transfer member 24 from which the excess solvent has been removed by the solvent removing unit 30, and transfers the image recorded on the intermediate transfer member 24 to the recording sheet 12.

  The transfer unit 32 conveys the recording paper 12 along the recording conveyance path 50 formed by the conveyance belt 46, and presses the recording paper 12 against the intermediate transfer body 24 in the conveyance process to transfer the image. .

  The conveyor belt 46 is an endless belt having a predetermined width (at least equal to or greater than the width of the intermediate transfer member 24), and is wound around three rollers 48A to 48C arranged at predetermined positions.

  The three rollers 48 </ b> A to 48 </ b> C are disposed so as to form an inverted triangular traveling path, and the roller 48 </ b> A located at the left end of the three rollers 48 </ b> A to 48 </ b> C is disposed below the roller 34 </ b> B that guides the intermediate transfer member 24. ing. A conveyance belt drive motor (not shown) is connected to one of the three rollers 48A to 48C, and the conveyance belt 46 wound by driving this conveyance belt drive motor is shown in the figure. Drive at a predetermined speed in the direction of the arrow (clockwise direction).

  The conveying belt 46 is wound around the three rollers 48A to 48C to form a horizontal recording conveying path 50 at the upper portion thereof, and is sandwiched between the roller 48A and the roller 34B at the installation position of the roller 48A. Then, it is pressed against the intermediate transfer member 24.

  The recording paper 12 is transported along the recording transport path 50 by the transport belt 46, and is pressed against the intermediate transfer member 24 by a roller 48A during the transport process, so that an image formed on the recording surface of the intermediate transfer member 24 is transferred. And transferred onto the recording surface.

  In the recording unit 16 configured as described above, first, the processing liquid is discharged from the processing liquid head 36P to the traveling intermediate transfer member 24, and the processing liquid is applied onto the recording surface. Next, ink of each color is ejected from the ink heads 36C, 36M, 36Y, and 36K onto the recording surface of the intermediate transfer member 24 to which the processing liquid has been applied, and an image is formed on the recording surface. Thereafter, the solvent absorbing roller 38 is brought into contact with the recording surface of the intermediate transfer member 24 running in the solvent removing unit 30 to absorb and remove excess solvent. Then, in synchronization with the intermediate transfer member 24 from which the excess solvent has been absorbed and removed, the recording paper 12 is conveyed through the recording conveyance path 50, and the recording surface (upper surface) of the recording paper 12 is transferred to the intermediate transfer member during the conveyance process. The image recorded on the intermediate transfer member 24 is pressed onto the recording surface 24 and transferred onto the recording surface of the recording paper 12.

  The recording unit 16 may be provided with a cleaning unit that cleans the recording surface of the intermediate transfer member 24 after transfer, if necessary. As the configuration of the cleaning unit, for example, the cleaning is performed by bringing the porous body soaked with the cleaning liquid into contact with the recording surface of the intermediate transfer body 24 after the transfer, while supplying the cleaning liquid to the recording surface of the intermediate transfer body 24. A configuration in which the brush is brought into contact for cleaning can be employed.

  The reversing unit 18 reverses the front and back of the recording paper 12 by conveying the recording paper 12 on which single-sided recording has been completed during double-sided recording along a predetermined reversing conveyance path 52.

  The inversion conveyance path 52 includes an inclined first inversion conveyance path 52A, a horizontal second inversion conveyance path 52B, an inclined third inversion conveyance path 52C, and a horizontal fourth inversion conveyance path 52D. , A vertical fifth reversing conveyance path 52E, which is formed by, for example, a roller or a belt.

  Here, with respect to the first reversing conveyance path 52A, the fourth reversing conveyance path 52D, and the fifth reversing conveyance path 52E, the recording paper 12 can be conveyed only in one direction (the direction indicated by the arrow in the figure). The second reversing conveyance path 52B and the third reversing conveyance path 52C are configured to be capable of conveying the recording paper 12 in both directions.

  The recording paper 12 on which single-sided recording has been completed by the recording unit 16 is guided to the first reversing conveyance path 52A by a conveyance path switching unit (not shown) during double-sided recording. The recording paper 12 guided to the first reversing transport path 52A is transported sequentially from the first reversing transport path 52A to the second reversing transport path 52B and the third reversing transport path 52C. When the trailing edge of the recording paper 12 reaches the second reversing conveyance path 52B, the conveying directions of the second reversing conveying path 52B and the third reversing conveying path 52C are reversed, and the conveying direction is reversed. The As a result, the recording paper 12 is guided from the second reversing transport path 52B to the fourth reversing transport path 52D, and is sequentially transported to the fourth reversing transport path 52D and the fifth reversing transport path 52E. The paper is transferred to the second paper feed conveyance path 22 </ b> B of the paper feed conveyance path 22. Then, the front and back are reversed at the stage of delivery to the second paper feed conveyance path 22B.

  Thereafter, the recording paper 12 is transferred from the second paper feed conveyance path 22B to the recording conveyance path 50 of the recording unit 16, and an image is formed on the back surface that is on the upper side in the course of being conveyed through the recording conveyance path 50. Is recorded.

  At the time of single-sided recording, the recording paper 12 is guided to a fixing conveyance path 54 by a conveyance path switching unit (not shown) after completion of single-sided recording, and is conveyed through the fixing conveyance path 54 to the fixing unit 20. Led.

  The same applies after completion of double-sided recording during double-sided recording. That is, after the double-sided recording is completed, it is guided to the fixing transport path 54 by a transport path switching unit (not shown), transported through the fixing transport path 54, and guided to the fixing unit 20.

  The fixing conveyance path 54 is formed by, for example, a roller or a belt.

  The fixing unit 20 is provided at a terminal position of the fixing conveyance path 54 and includes a pair of fixing rollers 56A and 56B. The fixing unit 20 heats and presses the recording paper 12 by passing the recording paper 12 between the pair of fixing rollers 56A and 56B, thereby fixing the image formed on the recording surface.

  In the following description, the upper fixing roller 56A is referred to as an upper fixing roller 56A and the lower fixing roller 56B is referred to as a lower fixing roller 56B as necessary. During single-sided recording, the upper fixing roller 56A is a roller in contact with the image, and the lower fixing roller 56B is a roller not in contact with the image.

  FIG. 4 is a schematic diagram showing a schematic configuration of the fixing unit 20. As shown in the figure, the pair of fixing rollers 56A and 56B are provided in pressure contact with each other. A fixing roller driving motor (not shown) is connected to one of the fixing rollers. By driving the fixing roller driving motor, the pair of fixing rollers 56A and 56B are pressed against each other.

  As shown in the figure, the fixing rollers 56A and 56B have heaters 58A and 58B, respectively, and are heated to the heaters 58A and 58B to be adjusted to a predetermined temperature.

  The temperatures of the fixing rollers 56A and 56B are individually detected by temperature sensors 62A and 62B installed close to the surfaces of the fixing rollers 56A and 56B, and the detected temperatures are respectively detected by the fixing controllers 60A and 60B. Is output.

  The fixing controllers 60A and 60B control the driving of the heaters 58A and 58B according to a command from a system controller, which will be described later, and control the temperatures of the fixing rollers 56A and 56B. That is, the driving of the heaters 58A and 58B is controlled based on the outputs of the temperature sensors 62A and 62B so that the temperatures of the fixing rollers 56A and 56B become the temperatures instructed by the system controller, and the temperatures of the fixing rollers 56A and 56B are controlled. To control.

  As will be described later, in the ink jet recording apparatus 10 of the present embodiment, temperature control of the fixing rollers 56A and 56B is performed according to the state of the apparatus. Specifically, the state of the apparatus is divided into three states, a standby state, a single-sided recording state, and a double-sided recording state, and the set temperatures of the fixing rollers 56A and 56B are defined for each state, and the state of the apparatus at that time is determined. Accordingly, temperature control of the fixing rollers 56A and 56B is performed so that the set temperature is reached. Therefore, it is set to the temperature set for standby in the standby state, to the temperature set for single-sided recording in the single-sided recording state, and to the temperature set for double-sided recording in the double-sided recording state. The temperatures of the fixing rollers 56A and 56B are controlled.

  FIG. 5 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10 of the present embodiment.

  The inkjet recording apparatus 10 includes a communication interface 70, a system controller 72, an image memory 74, a ROM 75, a motor control unit 76, a solvent removal control unit 78, a fixing control unit 60A and 60B, a recording medium type detection unit 79, a print control unit 80, An image processing unit 81, an image buffer memory 82, a head driver 84, and the like are provided.

  The communication interface 70 is an interface unit that receives image data sent from the host computer 86. A serial interface or a parallel interface can be applied to the communication interface 70. In this part, a buffer memory (not shown) for speeding up communication may be mounted.

  Image data sent from the host computer 86 is taken into the inkjet recording apparatus 10 via the communication interface 70 and temporarily stored in the image memory 74.

  The image memory 74 is a storage unit that temporarily stores an image input via the communication interface 70, and data is read and written through the system controller 72. The image memory 74 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The ROM 75 stores system parameters and various control programs. A rewritable storage medium such as an EEPROM may be applied to the ROM 75.

  The system controller 72 is composed of a central processing unit (CPU) and its peripheral circuits and the like, and in accordance with a predetermined control program, the communication interface 70, the image memory 74, the motor control unit 76, the fixing control units 60A and 60B, and the solvent removal control unit. Control each part such as 78.

  The motor control unit 76 controls the driving of each motor (for example, a motor that drives each conveyance path of the recording paper 12 or a motor that drives the intermediate transfer member 24) installed in the apparatus according to an instruction from the system controller 72. To do.

  The fixing controllers 60A and 60B control the driving of the heaters 58A and 58B of the fixing unit 20 according to instructions from the system controller 72, and control the temperatures of the fixing rollers 56A and 56B. That is, the driving of the heaters 58A and 58B is controlled based on the outputs of the temperature sensors 62A and 62B so that the temperatures of the fixing rollers 56A and 56B become the temperatures instructed by the system controller.

  The solvent removal control unit 78 controls driving of the solvent absorption roller driving unit 88 and the solvent absorption pump 42 in accordance with an instruction from the system controller 72. That is, the solvent absorbing roller driving means 88 is driven at a predetermined timing to press the solvent absorbing roller 38 against the intermediate transfer body 24 and the solvent absorption pump 42 is driven at a predetermined timing to remove excess solvent from the intermediate transfer body 24. Remove by suction.

  The recording medium type detection unit 79 detects the type of recording medium to be recorded and outputs the detection result to the system controller 72. As a recording medium type detection method, for example, an identifier (a visible or invisible mark corresponding to the recording medium type) is added to the recording medium to be recorded, and this is detected by a sensor to determine the type. Method, a method in which the surface of a recording medium is imaged by an imaging means, and the type is discriminated by image recognition, and when a recording medium contained in a container such as a cartridge is set in a paper feed unit and used, A method of discriminating the type by detecting an attached identifier (including a barcode or an IC tag in addition to a visible or invisible mark, etc.) with a sensor can be employed. Of course, other known detection methods can also be employed.

  The print control unit 80 outputs the image data in the image memory 74 to the image processing unit 81 under the control of the system controller 72.

  The image processing unit 81 performs necessary signal processing on the input image data to generate a signal for print control. The print control signal (dot data) generated by the image processing unit 81 is supplied to the head driver 84 via the print control unit 80.

  The image buffer memory 82 temporarily stores data such as image data and parameters when the image processing unit 81 processes image data.

  In FIG. 5, the image buffer memory 82 is configured to accompany the print control unit 80, but it can also be used as the image memory 74.

  In addition, the print controller 80 and the system controller 72 can be integrated to form a single processor.

  The head driver 84 generates signals for driving the recording heads 36P, 36C, 36M, 36Y, and 36K based on the dot data (printing data) given from the print control unit 80, and the generated driving signals are recorded for each recording. Supply to heads 36P, 36C, 36M, 36Y, 36K. As a result, the ejection amount and ejection timing of the ink droplets ejected from the recording heads 36P, 36C, 36M, 36Y, and 36K are controlled, and a desired dot size and dot arrangement are realized.

  The operation of the inkjet recording apparatus 10 of the present embodiment configured as described above is as follows.

  First, the flow of the process of recording an image on the recording paper 12 in the inkjet recording apparatus 10 of the present embodiment will be outlined.

  As described above, the inkjet recording apparatus 10 of the present embodiment can selectively perform single-sided recording and double-sided recording on the recording paper 12.

  First, the flow of image recording processing during single-sided recording will be described.

  First, the recording paper 12 is fed from the paper feeding unit 14 toward the paper feeding conveyance path 22.

  The recording paper 12 fed to the paper feed transport path 22 is transported through the first paper feed transport path 22A and the second paper feed transport path B of the paper feed transport path 22, and It is sent out to the recording conveyance path 50.

  On the other hand, in the recording unit 16, an intermediate transfer member drive motor (not shown) is driven, and the intermediate transfer member 24 starts to travel. Then, the processing liquid is discharged from the processing liquid head 36 </ b> P to the traveling intermediate transfer member 24, and the processing liquid is applied onto the recording surface.

  The intermediate transfer member 24 to which the treatment liquid is applied then ejects ink of each color from the ink heads 36C, 36M, 36Y, and 36K, thereby forming an image on the recording surface.

  Next, the intermediate transfer member 24 on which the image is formed is brought into contact with the recording surface on which the image is formed, and the solvent absorption roller 38 is brought into contact with the intermediate transfer member 24 to absorb and remove the excess solvent.

  Then, in synchronization with the intermediate transfer member 24 from which the excess solvent has been absorbed and removed, the recording paper 12 conveyed from the paper supply unit 14 is conveyed through the recording conveyance path 50, and recording of the recording paper 12 is performed in the conveyance process. The image is transferred to the surface (upper surface). That is, in the process in which the recording paper 12 passes between the roller 34B and the roller 48A, the upper surface of the recording paper 12 is pressed against the recording surface of the intermediate transfer member 24, and the image recorded on the intermediate transfer member 24 becomes the recording paper. 12 is transferred to the upper surface.

  The recording paper 12 onto which the image has been transferred by the recording unit 16 is conveyed through the recording conveyance path 50 as it is, and is guided to the fixing conveyance path 54 by a conveyance path switching unit (not shown). Then, it is conveyed through the fixing conveyance path 54 and guided to the fixing unit 20.

  The recording paper 12 conveyed to the fixing unit 20 is passed between a pair of fixing rollers 56A and 56B, and heated and pressed by the pair of fixing rollers 56A and 56B, whereby an image formed on the upper surface thereof. Is established.

  At this time, the pair of fixing rollers 56 </ b> A and 56 </ b> B is adjusted to a single-side recording temperature to heat and press the recording paper 12. This point will be described in detail later.

  After that, the recording paper 12 fixed by the fixing unit 20 is transported through a paper delivery path (not shown) and is ejected from the paper delivery unit.

  The above is the flow of image recording processing during single-sided recording.

  Next, the flow of image recording processing during double-sided recording will be described.

  First, the recording paper 12 is fed from the paper feeding unit 14 toward the paper feeding conveyance path 22.

  The recording paper 12 fed to the paper feed transport path 22 is transported through the first paper feed transport path 22A and the second paper feed transport path B of the paper feed transport path 22, and It is sent out to the recording conveyance path 50.

  On the other hand, in the recording unit 16, an intermediate transfer member drive motor (not shown) is driven, and the intermediate transfer member 24 starts to travel. Then, the processing liquid is discharged from the processing liquid head 36 </ b> P to the traveling intermediate transfer member 24, and the processing liquid is applied onto the recording surface.

  The intermediate transfer member 24 to which the treatment liquid has been applied is then ejected with ink of each color from the ink heads 36C, 36M, 36Y, 36K, and a surface image is formed on the recording surface.

  Next, the intermediate transfer member 24 on which the image is formed is brought into contact with the recording surface on which the image is formed, and the solvent absorption roller 38 is brought into contact with the intermediate transfer member 24 to absorb and remove the excess solvent.

  Then, in synchronization with the intermediate transfer member 24 from which the excess solvent has been absorbed and removed, the recording paper 12 conveyed from the paper supply unit 14 is conveyed through the recording conveyance path 50, and the front side of the recording paper 12 in the conveyance process. The image is transferred to the recording surface. That is, while the recording paper 12 passes between the roller 34B and the roller 48A, the recording surface on the front side of the recording paper 12 is pressed against the recording surface of the intermediate transfer body 24, and the image recorded on the intermediate transfer body 24 is changed. Then, the image is transferred to the recording surface on the front side of the recording paper 12.

  The recording paper 12 with the image transferred to the front recording surface is conveyed as it is in the recording conveyance path 50 and guided to the reversal conveyance path 52 by a conveyance path switching unit (not shown). Then, the sheet is conveyed through the reversing conveyance path 52 and sent out again to the recording conveyance path 50 of the recording unit 16.

  The recording sheet 12 is fed to the recording conveyance path 50 of the recording unit 16 with the recording surface on the reverse side turned up in the process of being conveyed through the reversing conveyance path 52. That is, the first reversing transport path 52A, the second reversing transport path 52B, the third reversing transport path 52C, the fourth reversing transport path 52D, and the fifth reversing transport path 52 of the reversing transport path 52 while reversing the transport direction. By sequentially transporting the transport path 52 </ b> E and sending it to the paper feed transport path 22, the front and back sides are reversed at the stage of sending to the paper feed transport path 22.

  On the other hand, in the recording unit 16, the processing liquid is discharged from the processing liquid head 36 </ b> P to the traveling intermediate transfer body 24, the processing liquid is applied onto the recording surface, and the intermediate transfer body 24 to which the processing liquid is applied. In contrast, each color ink is ejected from each of the ink heads 36C, 36M, 36Y, 36K, and an image for the back surface is formed on the recording surface. Then, the solvent absorbing roller 38 is brought into contact with the intermediate transfer member 24 on which the image is formed, and the excess solvent is absorbed and removed.

  In synchronization with the intermediate transfer member 24 from which the excess solvent has been absorbed and removed, the recording paper 12 whose front and back are reversed is transported through the recording transport path 50, and an image is formed on the recording surface on the back side of the recording paper 12 in the transport process. Transcribed. That is, in the process in which the recording paper 12 passes between the roller 34B and the roller 48A, the recording surface on the back side of the recording paper 12 is pressed against the recording surface of the intermediate transfer member 24, and the image recorded on the intermediate transfer member 24 is changed. Then, it is transferred to the recording surface on the back side of the recording paper 12.

  The recording sheet 12 on which the image is transferred to the recording surface on the back side by the recording unit 16 and the image recording on both sides is completed is conveyed as it is through the recording conveyance path 50, and the conveyance path switching means (not shown) fixes the conveyance path 54 for fixing. Led to. Then, it is conveyed through the fixing conveyance path 54 and guided to the fixing unit 20.

  The recording paper 12 conveyed to the fixing unit 20 is passed between a pair of fixing rollers 56A and 56B, and is heated and pressed by the pair of fixing rollers 56A and 56B. The image is fixed.

  At this time, the pair of fixing rollers 56 </ b> A and 56 </ b> B is adjusted to a temperature for double-sided recording, and heats and pressurizes the recording paper 12. This will be described in detail later.

  After that, the recording paper 12 fixed by the fixing unit 20 is transported through a paper delivery path (not shown) and is ejected from the paper delivery unit.

  The above is the flow of the image recording process at the time of duplex recording.

  As described above, the inkjet recording apparatus 10 of the present embodiment can selectively perform single-sided recording and double-sided recording on the recording paper 12.

  As described above, in the inkjet recording apparatus 10 of the present embodiment, when the fixing process is performed on the recording paper 12 after image recording, the temperatures of the fixing rollers 56A and 56B are set to different temperatures for single-sided recording and double-sided recording. The fixing process is performed after setting. That is, at the time of single-sided recording, the temperature of the fixing rollers 56A and 56B is set to the temperature set for single-sided recording and the fixing process is performed. At the time of double-sided recording, the temperature of the fixing rollers 56A and 56B is set to the temperature set for double-sided recording. The fixing process is performed by setting the temperature.

  The temperature control procedure for the fixing rollers 56A and 56B will be described below.

  FIG. 6 is a flowchart showing a procedure for controlling the temperature of the fixing rollers 56A and 56B.

  If there is no image data to be recorded on the recording paper 12, the inkjet recording apparatus 10 waits for reception of image data from the host computer 86 in a predetermined standby state (step S10).

  In this standby state 10, the fixing unit 20 is set to the A state (step S12). That is, the temperature of the fixing rollers 56A and 56B installed in the fixing unit 20 is set to a preset standby temperature, and the state is maintained.

  As the standby temperatures, for example, the upper fixing roller 56A is set to 50 ° C., and the lower fixing roller 56B is set to 30 ° C. This information is stored in the ROM 75.

  Based on the information stored in the ROM 75, the system controller 72 instructs the fixing controllers 60A and 60B so that the temperatures of the fixing rollers 56A and 56B become standby temperatures. In accordance with an instruction from the system controller 72, the fixing controllers 60A and 60B drive the heaters 58A and 58B so that the temperatures of the fixing rollers 56A and 56B become standby temperatures based on the outputs of the temperature sensors 62A and 62B. To control.

  As described above, the temperature of the fixing rollers 56A and 56B is maintained at the standby temperature during standby.

  On the other hand, during this standby, the system controller 72 determines whether or not image data is received from the host computer 86 (step S14). If it is determined that image data is received, the system controller 72 starts image recording control processing.

  First, it is determined whether the received image data is double-sided recording (step S16).

  In the case of single-sided recording, the fixing unit 20 is set to the B state (step S18). That is, the temperature of the fixing rollers 56A and 56B installed in the fixing unit 20 is set to a preset single-sided recording temperature.

  As the single-side recording temperature, for example, the upper fixing roller 56A is set to 80 to 150 ° C., and the lower fixing roller 56B is set to 40 to 80 ° C. In other words, during single-sided recording, what is important for image fixing is the temperature of the upper fixing roller 56A in contact with the image, and the temperature of the lower fixing roller 56B not in contact with the image can be maintained by control. The temperature can be lowered to a certain level. Accordingly, the upper fixing roller 56A in contact with the image is set to a high temperature (for example, 80 to 150 ° C.) necessary for fixing the image, and the lower fixing roller 56B not in contact with the image is set to that temperature. Compared to the medium temperature (for example, 40 to 80 ° C.).

  The temperature of the lower fixing roller 56B is preferably lowered as much as possible from the viewpoint of energy saving. However, if the temperature is lowered too much, it becomes difficult to maintain the temperature of the upper fixing roller 56A. .

  In the present embodiment, the temperature of the upper fixing roller 56A is set to 90 ° C., and the temperature of the lower fixing roller 56B is set to 50 ° C. as the single-side recording temperature. This information is stored in the ROM 75.

  Based on the information stored in the ROM 75, the system controller 72 instructs the fixing controllers 60A and 60B so that the temperatures of the fixing rollers 56A and 56B become the single-sided recording temperature. In accordance with an instruction from the system controller 72, the fixing controllers 60A and 60B set the heaters 58A and 58B based on the outputs of the temperature sensors 62A and 62B so that the temperatures of the fixing rollers 56A and 56B become the single-side recording temperature. Control the drive.

  As described above, when the image data for single-sided recording is received, the fixing unit 20 is set to the B state (step S18), and the temperatures of the upper fixing roller 56A and the lower fixing roller 56B are controlled to the temperatures for single-sided recording, respectively. The

  The system controller 72 determines whether or not the temperature of the fixing rollers 56A and 56B is set to the temperature for single-sided recording based on the information from the fixing control units 60A and 60B (step S20). If it is determined that it has been set, an image recording process is executed (step S22). That is, the recording paper 12 is fed from the paper feeding unit 14 to the recording unit 16, while an image is formed on the intermediate transfer body 24 by the recording unit 16, and the image is transferred to the recording surface (upper surface) of the recording paper 12. Then, the recording paper 12 on which the image is recorded is heated and pressed by the fixing rollers 56A and 56B of the fixing unit 20, thereby fixing the image and discharging the paper.

  The system controller 72 determines whether or not the image recording process has been completed (step S24). If the system controller 72 determines that the recording process has been completed, the system controller 72 returns to step S14 to determine the presence or absence of the next image data. If there is no next image data, the process returns to step S10 to return to the standby state.

  Thus, when the image data received from the host computer 86 is single-sided recording, the temperature of the fixing rollers 56A and 56B is set to the temperature for single-sided recording, and image recording and fixing processing are performed.

  On the other hand, when the image data received from the host computer 86 is double-sided recording, that is, when it is determined in step S16 that double-sided recording is performed, the fixing unit 20 is set to the C state (step S26). That is, the temperature of the fixing rollers 56A and 56B installed in the fixing unit 20 is set to a preset temperature for duplex recording.

  The temperature for double-sided recording is set to the same temperature by the upper and lower fixing rollers 56A and 56B, for example, 80 to 150 ° C. That is, in this case, since the image contacts both the upper and lower fixing rollers, the upper and lower fixing rollers 56A and 56B are both set to the same temperature, and both are at a high temperature (for example, 80 to 150 ° C.) necessary for fixing the image. ).

  In the present embodiment, the temperature of the upper fixing roller 56A is set to 90 ° C., and the temperature of the lower fixing roller 56B is also set to 90 ° C. as the temperatures for double-sided recording. This information is stored in the ROM 75.

  Based on the information stored in the ROM 75, the system controller 72 instructs the fixing controllers 60A and 60B so that the temperature of the fixing rollers 56A and 56B becomes the temperature for double-sided recording. In accordance with an instruction from the system controller 72, the fixing controllers 60A and 60B set the heaters 58A and 58B based on the outputs of the temperature sensors 62A and 62B so that the temperatures of the fixing rollers 56A and 56B become the single-side recording temperature. Control the drive.

  Thus, when image data for double-sided recording is received, the fixing unit 20 is set to the C state (step S26), and the temperatures of the upper fixing roller 56A and the lower fixing roller 56B are controlled to the temperatures for double-sided recording, respectively. The

  The system controller 72 determines whether or not the temperature of the fixing rollers 56A and 56B has been set to the temperature for double-sided recording based on the information from the fixing controllers 60A and 60B (step S28). If it is determined that it has been set, an image recording process is executed (step S30). That is, the recording paper 12 is fed from the paper feeding unit 14 to the recording unit 16, while an image is formed on the intermediate transfer member 24 by the recording unit 16 and the image is transferred to the surface of the recording paper 12. Thereafter, the recording paper 12 is reversed by the reversing unit 18 and the recording paper 12 is fed again to the recording unit 16, while an image is formed on the intermediate transfer member 24 by the recording unit 16, and the back surface of the recording paper 12 is formed. Transfer the image. Then, the recording paper 12 on which the images are recorded on both sides is heated and pressed by the fixing rollers 56A and 56B of the fixing unit 20, thereby fixing the image and discharging the paper.

  The system controller 72 determines whether or not the image recording process has been completed (step S32). If the system controller 72 determines that the recording process has been completed, the system controller 72 returns to step S14 to determine the presence or absence of the next image data. If there is no next image data, the process returns to step S10 to return to the standby state.

  Thus, when the image data received from the host computer 86 is double-sided recording, the temperature of the fixing rollers 56A and 56B is set to the temperature for double-sided recording, and image recording and fixing processing are performed.

  As described above, in the inkjet recording apparatus 10 of the present embodiment, the temperatures of the fixing rollers 56A and 56B are set to the standby temperature during standby, the single-side recording temperature during single-sided recording, and the double-sided recording temperature during double-sided recording. Since each process is performed after setting, energy saving can be achieved. That is, since the temperature of the fixing rollers 56A and 56B can be set to the minimum temperature necessary for each processing, it is possible to suppress wasteful power consumption and effectively save energy.

  Further, in the inkjet recording apparatus 10 of the present embodiment, the fixing process is performed after the completion of double-sided recording during double-sided recording, so that it is possible to effectively prevent image recording deviation from occurring on both the front and back sides. And an image of good quality can be recorded. That is, in the case of double-sided recording, once the front surface recording is completed, once the fixing process is performed, the recording paper may be deformed and recording misalignment may occur during backside recording. However, as in the ink jet recording apparatus 10 of the present embodiment. By performing the fixing process after completion of double-sided recording, it is possible to effectively prevent image recording deviation from occurring on both the front and back sides.

  In this embodiment, the temperature of the fixing rollers 56A and 56B is controlled to be a constant temperature during single-sided recording and double-sided recording. However, an allowable range is provided, and the temperature of the fixing rollers 56A and 56B is set. You may make it control so that it may be kept in a tolerance. That is, for example, during single-sided recording, an allowable range of ± 1 ° C. is provided with respect to the temperature set for single-sided recording, and control is performed so that the temperatures of the fixing rollers 56A and 56B are maintained within that range. May be. Similarly, during double-sided recording, an allowable range of ± 1 ° C. is provided for the temperature set for double-sided recording, and the temperature of the fixing rollers 56A and 56B is controlled within that range. Good.

  In the present embodiment, in the case of single-sided recording, both the fixing rollers 56A and 56B start image recording processing when the temperature for single-sided recording is reached. The image recording process may be started when the temperature of the fixing roller 56A reaches the one-side recording temperature.

  Further, in the present embodiment, the case where the present invention is applied to an intermediate transfer type inkjet recording apparatus has been described as an example. However, the application of the present invention is not limited to this, and ink is directly applied to a recording medium. The present invention can be similarly applied to an ink jet recording apparatus that forms an image by ejecting the ink.

  In the case where the present invention is applied to an intermediate transfer type ink jet recording apparatus, as in the ink jet recording apparatus 10 of the present embodiment, the fixing unit 20 is installed downstream of the transfer process, thereby rub-off the transferred image. It becomes possible to ensure the sex.

  In this embodiment, the intermediate transfer member is composed of an endless belt. However, the configuration of the intermediate transfer member is not limited to this, and for example, as shown in FIG. Alternatively, an intermediate transfer member 90 formed in a drum shape may be used. In this case, the ink heads 36C, 36M, 36Y, and 36K are arranged concentrically with the intermediate transfer member 102. Then, ink is ejected onto the outer peripheral surface (recording surface) of the intermediate transfer member 102 to form an image on the recording surface. The recording paper 12 is conveyed between the intermediate transfer member 102 and a pressure roller 104 that is pressed against and rotates on the intermediate transfer member 102, and an image is transferred onto the recording surface in the conveyance process.

  In the ink jet recording apparatus 100 shown in FIG. 7, an example in which an image is formed on the intermediate transfer member 102 without using a processing liquid is shown. In the figure, reference numeral 106 denotes a preliminary fixing means, which heats the recording surface of the intermediate transfer member 102 to prefix the image formed on the intermediate transfer member 102 on the recording surface.

  In this embodiment, the case where the present invention is applied to a two-component reaction type ink jet recording apparatus that records an image by reacting a treatment liquid and ink has been described as an example. The present invention is not limited, and the present invention can be similarly applied to an ink jet recording apparatus that forms an image only with ink ejected from a recording head (see FIG. 7).

  In addition, by applying the present invention to a two-component reaction type ink jet recording apparatus, moisture absorbed by the recording medium can be limited, and image deterioration due to deformation of the recording medium can be effectively prevented. . In particular, when performing double-sided recording, it is possible to effectively prevent the recording medium from being deformed after recording on the front surface and causing positional deviation during back-side recording, and it is possible to record images of good quality.

  In this embodiment, the fixing unit is configured to heat and press the recording medium between a pair of rollers that rotate in pressure contact with each other. However, the configuration of the fixing unit is not limited to this. . In addition, as shown in FIG. 8, the recording paper 12 may be heated and pressurized between a pair of fixing belts 110A and 110B that are pressed against each other. In this case, the fixing belts 110A and 110B can be individually adjusted in temperature by a heat source such as the heaters 112A and 112B. In the example shown in FIG. 8, the endless fixing belts 110A and 110B are wound around three rollers 114A and 114B arranged at predetermined positions so as to be pressed against each other. The fixing belts 110A and 110B are heated by the heaters 112A and 112B arranged in the above.

  In this embodiment, a heater is installed inside the fixing roller, and the roller is heated by the heater to adjust the temperature of the fixing roller. However, the configuration for adjusting the temperature of the roller is limited to this. However, the temperature may be adjusted using another heat source.

  In this embodiment, the temperature control of the fixing rollers 56A and 56B is performed according to the state of the apparatus, but the temperature control of the fixing rollers 56A and 56B is further performed according to the type of recording medium to be recorded. You may do it. That is, the single-sided recording temperature and the double-sided recording temperature are individually set according to the type of recording medium to be recorded, and the fixing roller 56A, according to the recording medium type detected by the recording medium type detection unit 79, The temperature of 56B may be controlled. As a result, an optimal fixing state can be realized according to the type of the recording medium, and a higher quality image can be recorded. At the same time, energy can be saved.

  The type of the recording medium is not particularly limited, and various recording media other than paper can be recorded.

  In the ink jet recording apparatus of the present embodiment, the upper fixing roller 56A has a temperature of 50.degree. C., the lower fixing roller 56B has a temperature of 30.degree. The temperature is set to 90 ° C., the temperature of the lower fixing roller 56B is set to 50 ° C., and the temperature for duplex recording is set to 90 ° C., and the temperature of the lower fixing roller 56B is set to 90 ° C. The temperature setting for single-sided recording and double-sided recording is not limited to this. It is preferable to set the temperature appropriately as appropriate according to the ink and recording medium to be used.

  For example, when the ink containing the color material or the polymer liquid having a glass transition temperature Tg of 30 ° C. or higher is contained in the treatment liquid, the temperature of the fixing rollers 56A and 56A at the time of single-sided recording and double-sided recording is set. Set to 30 ° C or higher. By setting the Tg of the polymer fine particles to 30 ° C. or higher, the polymer fine particles do not cause a film forming phenomenon in the non-heated state. Therefore, when the ink or the treatment liquid containing the polymer fine particles is ejected from the recording head or the treatment liquid head. Discharge reliability can be ensured.

  Further, an image is formed on a recording medium using a liquid containing a polymer fine particle having a glass transition temperature Tg of 30 ° C. or higher in an ink containing a color material or in a processing liquid in this manner, and 30 in a fixing step. By applying a temperature equal to or higher than 0 ° C., the polymer component is melted in the fixing step and the adhesion to the recording medium is increased, so that the abrasion resistance can be ensured.

1 is a schematic diagram showing a schematic configuration of an embodiment of an ink jet recording apparatus according to the present invention. Plan view showing the ejection surface of the recording head FIG. 2 is a cross-sectional view taken along line 3-3 of the recording head shown in FIG. Schematic diagram showing the schematic configuration of the fixing unit Main block diagram showing the system configuration of the inkjet recording apparatus Flowchart showing the temperature control procedure of the fixing roller Schematic diagram showing the schematic configuration of another example of the recording unit Schematic diagram showing the schematic configuration of another example of the fixing unit

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 12 ... Recording paper, 14 ... Paper feed part, 16 ... Recording part, 18 ... Reversing part, 20 ... Fixing part, 22 ... Feed path, 24 ... Intermediate transfer body, 26 ... Processing liquid Supply unit 28 ... Image forming unit 30 ... Solvent removal unit 36P ... Processing liquid head 36C, 36M, 36Y, 36K ... Ink head 38 ... Solvent absorption roller 56A, 56B ... Fixing roller 56A ... Up Fixing roller, 56B ... lower fixing roller), 58A, 58B ... heater, 60A, 60B ... fixing control unit, 62A, 62B ... temperature sensor, 72 ... system controller, 79 ... recording medium type detection unit

Claims (8)

An image forming apparatus capable of selectively performing single-sided recording and double-sided recording, wherein a recording medium on which an image is recorded by a recording unit is heated and pressed between a pair of rollers or belts that are pressed against each other. In an image forming apparatus having a fixing unit for fixing a recorded image,
Heating means for individually heating the pair of rollers or belts;
The heating means is controlled so that the temperature of the pair of rollers or belts is set in advance for single-sided recording during single-sided recording, and the temperature of the pair of rollers or belts is preliminarily set to double-sided recording during double-sided recording. Control means for controlling the heating means so as to have a temperature set for recording;
An image forming apparatus comprising:   At the time of single-sided recording, the temperature for the single-sided recording is set so that the temperature of the roller or belt that contacts the image is higher than the temperature of the roller or belt that does not contact the image. 2. The image forming apparatus according to claim 1, wherein the temperature for the double-sided recording is set so that both rollers or belts have substantially the same temperature.   3. The image forming apparatus according to claim 1, wherein during recording on both sides, after the images are recorded on both sides of the recording medium, the recording medium is passed between the pair of rollers or between the belts. . Detecting means for detecting the type of the recording medium;
Setting means for setting the temperature for single-sided recording and the temperature for double-sided recording according to the type of the recording medium detected by the detecting means;
The image forming apparatus according to claim 1, further comprising: The recording unit is
An intermediate transfer member;
An ink ejection means for ejecting ink to form an image on the intermediate transfer member;
5. The image forming apparatus according to claim 1, wherein the image formed on the intermediate transfer member is transferred to the recording medium to form an image on the recording medium. . The recording unit is
A treatment liquid applying means for applying a treatment liquid having an action of insolubilizing or aggregating the coloring material in the ink before the ink is ejected by the ink discharging means;
A solvent absorbing unit that absorbs and removes excess solvent of ink ejected by the ink discharging unit from the intermediate transfer member before transferring an image to the recording medium;
The image forming apparatus according to claim 5, further comprising:   The ink or treatment liquid contains polymer fine particles having a glass transition temperature Tg of 30 ° C or higher, while the roller or belt is set to have a temperature of 30 ° C or higher. The image forming apparatus according to any one of the above. In an image fixing method for fixing a recorded image by heating and pressurizing a recording medium on which an image is recorded between a pair of rollers or belts that rotate in contact with each other.
The temperature of the pair of rollers or belt when processing a recording medium having an image recorded on one side and the temperature of the pair of rollers or belt when processing a recording medium having an image recorded on both sides are individually set An image fixing method comprising: setting.

Images