JP2009031401A - Image forming apparatus, control method of image forming apparatus, control program, and its record medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the heat absorption section of a heat pump from being excessively cooled, in an image forming apparatus with the heat pump which moves heat absorbed by the heat absorption section to a heat radiation section whose temperature is higher than that of the heat absorption section, to radiate the heat and a fixing device which heats an unfixed toner image by using the heat radiated by the heat radiation section. <P>SOLUTION: The image forming apparatus includes a heat storage member 73 provided so that it can come into contact with a heat absorption member 72 and a heat storage member moving device 67 for changing the relative position between the heat absorption member 72 and the heat storage member 73 or the contact position of the heat storage member 73 with the heat absorption member 72. When the heating of the fixing device 40 is started, the operation of the heat storage member moving device 67 is controlled so that the heat storage member 73 and the heat absorption member 72 may be in a contact state with each other by a heat storage member movement control section 95. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a laser printer, or a multifunction printer. More specifically, the present invention relates to a technique for reducing power consumption of a fixing device in an image forming apparatus including a fixing device that heats and fixes an unfixed toner image formed on a recording material to the recording material. It is.

  An electrophotographic recording system is widely used in image forming apparatuses such as copying machines and facsimile machines. An electrophotographic image forming apparatus develops a latent image formed on an image carrier to form a toner image, electrostatically transfers the toner image onto a recording material, and converts the toner image onto a toner image transferred onto the recording material. The toner image is fixed on the recording material by applying heat and pressure at the heat fixing portion.

  By the way, in the electrophotographic image forming apparatus, the heat given to the recording material in the heat fixing unit becomes unnecessary after the fixing and is radiated to the air. For this reason, there is a problem that the temperature inside the image forming apparatus increases. Further, since the heat of the recording material after fixing is dissipated unnecessarily, there is a problem that energy use efficiency is low and power consumption is large.

Therefore, in Patent Document 1, the heat of the recording material after fixing is absorbed by the heat absorption part (cooling part) of the heat pump, and the absorbed heat is supplied from the heat dissipation part of the heat pump to the fixing part and used for heating the toner image. In this way, energy consumption efficiency is increased to reduce power consumption.
JP 2005-258003 A (published September 22, 2005)

  However, the technique of Patent Document 1 has a problem that the heat absorption part of the heat pump is supercooled immediately after the power is turned on (immediately after startup) or immediately after the start of the image forming operation, and condensation or freezing occurs in the heat absorption part.

  That is, immediately after the power is turned on or immediately after the start of the image forming operation, the amount of heat absorbed by the heat absorbing unit is less than the amount of heat supplied from the heat radiating unit to the fixing unit. And if the temperature of the heat absorption part falls too much, the water | moisture content in air will dew or freeze on the surface of a heat absorption part.

  If dew condensation occurs in the image forming apparatus, the recording material may be wrinkled due to moisture adhering to the recording material, or an adverse effect on electrical equipment such as current leakage may occur. In addition, when freezing occurs in the heat absorption part, the heat exchange efficiency of the heat absorption part decreases, and heat absorption cannot be performed stably.

  For this reason, in the technique of the above-mentioned Patent Document 1, the heat transfer action by the heat pump cannot be properly functioned immediately after the start of the image forming apparatus or immediately after the start of the image forming operation, and the power consumption can be sufficiently reduced. It was difficult.

  The present invention has been made in view of the above problems, and its purpose is to use a heat pump that dissipates heat by moving the heat absorbed by the heat absorption part to a heat radiation part having a temperature higher than that of the heat absorption part, and a heat radiation part. In an image forming apparatus including a fixing device that heats an unfixed toner image using heat radiated, it is to prevent a heat absorption portion of a heat pump from being overcooled.

  In order to solve the above-described problems, the image forming apparatus of the present invention heats an unfixed toner image formed on a recording material to fix the toner image on the recording material, and heat absorbed by the heat absorption unit. An image forming apparatus that heats an unfixed toner image using heat that is radiated from the heat radiating unit, and a heat pump that dissipates heat by moving to a heat radiating unit having a temperature higher than that of the heat absorbing unit, An endothermic member provided in the endothermic part to absorb external heat, a heat storage member provided in contact with the endothermic member, a relative position between the endothermic member and the heat storage member, or the endothermic heat in the heat storage member A driving means for changing a contact position with the member; and an operation of the driving means to control a relative position between the heat absorption member and the heat storage member or a contact position between the heat storage member and the heat absorption member. And control means for said control means, at start of heating the fixing device is characterized in that the said heat storage member and the heat absorbing member to control the operation of the drive means so that the contact state.

  According to said structure, in the thermal absorption member with which a thermal absorption part is equipped in order to absorb external heat, the thermal storage member provided so that a thermal absorption member can be contacted, and the relative position of thermal absorption member and thermal storage member, or thermal storage member Drive means for changing the contact position with the heat absorption member, and control means for controlling the relative position between the heat absorption member and the heat storage member or the contact position of the heat storage member with the heat absorption member by controlling the operation of the drive means. ing. Then, the control means controls the operation of the drive means so that the heat storage member and the heat absorption member are in contact with each other when heating of the fixing device is started. As described above, when the heat storage member is brought into contact with the heat absorption member at the start of heating of the fixing device, heat exchange is performed between the working fluid of the heat pump, the heat absorption member, and the heat storage member. Thereby, the heat capacity of the target cooled by the working fluid of the heat pump at the start of heating of the fixing device can be made larger than the conventional configuration in which heat exchange is performed between the working fluid of the heat pump and the heat absorbing member without the heat storage member. Therefore, it is possible to prevent the heat absorbing member from being overcooled and to prevent condensation and freezing.

  In addition, a temperature sensor that detects a temperature of a position of the heat storage member that contacts the heat absorbing member is provided, and the control unit is configured such that the temperature detected by the temperature sensor is lower than a first preset temperature that is set in advance. In addition, the relative position between the heat storage member and the heat absorption member is a position where the heat storage member and the heat absorption member are separated from each other or the contact area between the heat storage member and the heat absorption member is smaller than the contact area at the start of heating. It is good also as a structure which controls the operation | movement of the said drive means so that it may become the 2nd position which is a position.

  According to said structure, when the temperature of the position which contacts with respect to the thermal absorption member in a thermal storage member falls below 1st setting temperature, a thermal storage member is separated from a thermal absorption member, or the said thermal storage member and the said thermal absorption member The contact area can be reduced. Thereby, when the temperature of the heat storage member decreases, the amount of heat exchange from the heat absorption member to the heat storage member can be reduced, so that the heat absorbed by the heat absorption member can be efficiently supplied to the working fluid of the heat pump. , Heat utilization efficiency can be increased.

  In the state where the relative position between the heat storage member and the heat absorption member is the second position, the control means is configured such that the temperature detected by the temperature sensor is higher than a preset second set temperature. The relative position between the heat storage member and the heat absorption member is such that the contact area between the heat storage seat and the heat absorption member is larger than the contact area between the heat storage seat and the heat absorption member at the second position. It is good also as a structure which controls operation | movement of the said drive means so that it may be set to 1 position.

  According to said structure, when the temperature of a thermal storage member becomes higher than 2nd setting temperature, the contact area of a thermal storage member and a thermal absorption member can be enlarged. Thereby, heat can be supplied from the heat storage member to the heat absorption member, the amount of heat supplied to the working fluid of the heat pump via the heat absorption member can be increased, and heat utilization efficiency can be improved.

  In addition, a temperature sensor that detects a temperature of a position of the heat storage member that contacts the heat absorbing member is provided, and the control unit is configured such that the temperature detected by the temperature sensor is lower than a first preset temperature that is set in advance. In addition, the operation of the driving unit may be controlled so that a position of the heat storage member that is not in contact with the heat absorption member is brought into contact with the heat absorption member.

  According to said structure, when the temperature of the contact position with the heat absorption member in a heat storage member falls below 1st setting temperature as a result of the heat supply from a heat storage member to a heat absorption member, it contacts with the heat absorption member in a heat storage member. The position that has not been brought into contact with the heat absorbing member. Thereby, since the position before temperature fall by the heat supply to the heat absorption member in a heat storage member can be made to contact a heat absorption member, the heat supply amount from a heat storage member to a heat absorption member is increased, and heat utilization efficiency is improved. be able to.

  The first preset temperature is preferably higher than 0 ° C. and lower than room temperature. The room temperature may be a temperature outside the image forming apparatus or a temperature at a position not affected by the heat treatment in the fixing device inside the image forming apparatus.

  According to said structure, dew condensation and freezing in a heat absorption part can be prevented appropriately by making 1st preset temperature higher than 0 degreeC. Moreover, heat can be absorbed from ambient air in the part which is not contacting the heat absorption member in a thermal storage member by making 1st preset temperature below room temperature. Thereby, heat utilization efficiency can be made high by supplying the heat absorbed by the heat storage member to the heat absorption member.

  Further, the control means determines a relative position between the heat storage member and the heat absorption member when a predetermined time has elapsed after starting heating in the fixing device, and a position where the heat storage member and the heat absorption member are separated from each other. Or it is good also as a structure which controls the operation | movement of the said drive means so that the contact area of the said thermal storage member and the said heat absorption member may be set to the 2nd position which is a position smaller than the contact area at the time of the said heating start.

  When a predetermined time elapses after the heating in the fixing device is started, the temperature of the heat storage member in contact with the heat absorbing member decreases. Therefore, by predicting in advance the time until the temperature of the heat storage member falls below the predetermined temperature and setting the predetermined time, when the temperature of the heat storage member falls below the predetermined temperature, the heat storage member changes to the heat storage member. The amount of heat exchange with can be reduced. Thereby, the heat absorbed by the heat absorbing member can be efficiently supplied to the working fluid of the heat pump, and the heat utilization efficiency can be increased. Moreover, since it is not necessary to provide a temperature sensor for measuring the temperature of the heat storage member, the configuration of the image forming apparatus can be simplified and the manufacturing cost can be reduced.

  Further, the control means sets the endothermic position of the heat storage member that is not in contact with the endothermic member before the predetermined time elapses after the predetermined time has elapsed after starting the heating in the fixing device. It is good also as a structure which controls operation | movement of the said drive means so that it may contact a member.

  When a predetermined time elapses after the heating in the fixing device is started, the temperature of the heat storage member in contact with the heat absorbing member decreases. Therefore, by predicting in advance the time until the temperature of the heat storage member falls below the predetermined temperature and setting the predetermined time, the temperature at the contact position of the heat storage member with the heat absorbing member falls below the predetermined temperature. Sometimes, the position of the heat storage member that is not in contact with the heat absorption member can be brought into contact with the heat absorption member. Thereby, since the position before temperature fall by the heat supply to the heat absorption member in a heat storage member can be made to contact a heat absorption member, the heat supply amount from a heat storage member to a heat absorption member is increased, and heat utilization efficiency is improved. be able to. Moreover, since it is not necessary to provide a temperature sensor for measuring the temperature of the heat storage member, the configuration of the image forming apparatus can be simplified and the manufacturing cost can be reduced.

  In addition, a second temperature sensor that detects the temperature around the heat absorbing member is provided, and the control means is configured to perform the above operation when the temperature detected by the second temperature sensor is equal to or higher than a preset third set temperature. The relative position of the heat storage member to the heat absorption member is a position where the heat storage member and the heat absorption member are separated from each other, or a position where the contact area between the heat storage member and the heat absorption member is smaller than the contact area at the start of heating. It is good also as a structure which controls operation | movement of the said drive means so that it may be set to a 2nd position.

  When the temperature of the air around the heat absorbing member is high, the amount of heat that the heat absorbing member absorbs from the surrounding air increases. For this reason, even if the contact area of the heat storage member with respect to the heat absorption member is reduced or the heat storage member is separated from the heat absorption member, the heat radiation amount from the heat radiation portion can be maintained at the heat amount necessary for heating in the fixing device. . Moreover, since the heat supply amount from the heat storage member to the heat absorption member can be reduced, the heat storage amount in the heat storage member can be increased. Therefore, since the temperature of the heat storage member can be maintained in a high state, by increasing the contact area between the heat storage member and the heat absorption member as necessary, or by bringing the heat storage member and the heat absorption member into contact with each other, The amount of heat stored can be used effectively.

  Further, the recording apparatus may further include a conveying unit that conveys the recording material, and the heat absorbing member may be disposed to face the recording material conveyance path on the downstream side of the recording material in the conveyance direction of the recording material. Good.

  The temperature of the recording material after the fixing process is increased by heating in the fixing device. Therefore, according to the above configuration, the heat absorbing member is disposed so as to face the recording material conveyance path on the downstream side of the fixing device in the conveyance direction of the recording material. The heat utilization efficiency can be improved by absorbing the heat or the heat dissipated from the recording material after the fixing process by the heat absorbing member and reusing it for the heating process in the fixing device via the heat pump. Further, it is possible to prevent the temperature inside the image forming apparatus from rising due to heat dissipated from the recording paper.

  Further, it may be configured to include a first blower that generates an air flow in a direction from the conveyance path side where the recording material after the fixing process is conveyed toward the heat absorbing member side.

  According to the above configuration, by blowing air that has become high temperature due to heat dissipated from the recording paper to the heat absorbing member, heat dissipated from the recording paper can be absorbed more efficiently in the heat absorbing member, Heat utilization efficiency can be increased.

  The heat storage member may be arranged so as to face the recording material conveyance path on the downstream side of the heat absorption member in the recording material conveyance direction.

  The temperature of the recording material after the fixing process is increased by heating in the fixing device. Therefore, according to the above configuration, the heat of the recording material after the fixing process or the heat dissipated from the recording material after the fixing process is absorbed by the heat storage member, and the heat treatment is performed in the fixing device via the heat absorbing member and the heat pump. It can be reused and heat utilization efficiency can be increased. Further, it is possible to prevent the temperature inside the image forming apparatus from rising due to heat dissipated from the recording paper. In addition, since the heat absorbing member is disposed upstream of the heat storage member in the recording paper conveyance direction, the heat dissipated from the recording paper can be more effectively absorbed by the heat absorbing member. Therefore, the heat utilization efficiency can be further increased.

  Further, it may be configured to include a second blower that generates an air flow in a direction from the conveyance path side where the recording material after the fixing process is conveyed toward the heat storage member side.

  According to the above configuration, the air that has been heated by the heat dissipated from the recording paper is blown to the heat storage member, so that the heat dissipated from the recording paper can be absorbed more efficiently in the heat storage member, Heat utilization efficiency can be increased.

  The fixing device includes a heating member that heats the unfixed toner image, and the heating member is supplied from heat radiated from the heat radiating unit and electric heating means that converts electricity into heat. It is good also as a structure heated with heat.

  The temperature of the heat radiating portion of the heat pump is lowered when the heat absorption amount of the heat absorbing portion is small. According to the above configuration, even if the heat absorption amount of the heat absorption part is small and the temperature of the heat radiation part is lower than the temperature for heating the temperature of the fixing device to the temperature at the time of the fixing operation, it is insufficient by the electric heating means. The amount of heat generated can be compensated, and the fixing operation can be performed appropriately.

  Further, the heating member is a hollow roller member, the heat radiating portion is disposed in a hollow portion of the roller member, and the electric heating means is provided so as to contact an outer peripheral surface of the roller member. It is good also as composition which has.

  In general, the electric heating means can perform temperature control with higher accuracy than the heat radiating part of the heat pump, and the response speed for temperature control is faster. Therefore, according to said structure, the surface temperature of a roller member can be controlled rapidly and accurately by providing an electric heating means so that it may contact | abut on the outer peripheral surface of a roller member. Further, by providing the heat radiating portion in the hollow portion of the roller member, the apparatus size can be reduced as compared with the case where it is provided outside the roller member.

  Further, the heating member is a belt member stretched around a plurality of support rollers including a first support roller and a second support roller, and the first support roller and the second support roller have a hollow shape, The heat dissipating part may be provided in the hollow part of the first support roller, and the electric heating means may be provided in the hollow part of the second support roller.

  In general, since the belt member can have a thin wall structure, the temperature response speed is fast. Therefore, according to said structure, the surface temperature of a roller member can be controlled rapidly and accurately.

  In addition, the belt member is configured to rotate along the stretching direction, and the first support roller is downstream of the contact portion of the belt member with the pressure roller in the rotation direction, and It is good also as a structure arrange | positioned so that it may contact | abut to the said belt member in the upstream of a rotation direction rather than the contact part with a said 2nd support roller.

  In general, the electric heating means can perform temperature control with higher accuracy than the heat radiating part of the heat pump, and the response speed for temperature control is faster. Therefore, according to said structure, the 2nd instruction | indication roller heated by the electrical heating means is a downstream of the rotation direction of a belt member rather than the 1st support roller heated by a thermal radiation part, and a belt member and a pressure roller The temperature of the belt member at the contact portion with the pressure roller can be controlled quickly and accurately.

  In order to solve the above problems, the image forming apparatus control method of the present invention heats an unfixed toner image formed on a recording material and fixes the toner image on the recording material, and the heat absorbing portion absorbs the fixing device. A heat pump that dissipates heat by moving heat to a heat dissipating part having a temperature higher than that of the heat absorbing part, and an image forming apparatus that heats an unfixed toner image using heat that the fixing device dissipates from the heat dissipating part. In the control method, the image forming apparatus includes: a heat absorbing member provided in the heat absorbing unit to absorb external heat; a heat storage member provided in contact with the heat absorbing member; the heat absorbing member; A driving means for changing a position relative to the heat storage member or a contact position of the heat storage member with the heat absorption member, and at the start of heating of the fixing device, the heat storage member and the heat absorption unit Contact Is characterized by controlling the operation of said driving means so as to.

  According to the above configuration, the image forming apparatus includes a heat absorption member provided in the heat absorption unit to absorb external heat, a heat storage member provided to be in contact with the heat absorption member, and a relative relationship between the heat absorption member and the heat storage member. Driving means for changing the position or the contact position of the heat storage member with the heat absorbing member. Then, when the heating of the fixing device is started, the operation of the driving unit is controlled so that the heat storage member and the heat absorption member are in contact with each other. As described above, when the heat storage member is brought into contact with the heat absorption member at the start of heating of the fixing device, heat exchange is performed between the working fluid of the heat pump, the heat absorption member, and the heat storage member. Thereby, the heat capacity of the target cooled by the working fluid of the heat pump at the start of heating of the fixing device can be made larger than the conventional configuration in which heat exchange is performed between the working fluid of the heat pump and the heat absorbing member without the heat storage member. Therefore, it is possible to prevent the heat absorbing member from being overcooled and to prevent condensation and freezing.

  The image forming apparatus may be realized by a computer. In this case, a control program for causing the image forming apparatus to be realized by the computer by causing the computer to operate as the control unit, and the program are recorded. Computer-readable recording media are also included in the scope of the present invention.

  As described above, the image forming apparatus according to the present invention includes a heat absorption member provided in the heat absorption unit to absorb external heat, a heat storage member provided in contact with the heat absorption member, the heat absorption member, and the above. A drive means for changing a relative position with the heat storage member or a contact position of the heat storage member with the heat absorption member, and a relative position between the heat absorption member and the heat storage member or the heat storage by controlling the operation of the drive means. Control means for controlling a contact position of the member with the heat absorbing member, and the control means is configured to control the driving means so that the heat storage member and the heat absorbing member are in contact with each other when heating of the fixing device is started. Control the behavior.

  Further, according to the control method of the image forming apparatus of the present invention, the image forming apparatus includes: a heat absorbing member provided in the heat absorbing unit for absorbing external heat; and a heat storage member provided in contact with the heat absorbing member. And a driving means for changing a relative position between the heat absorption member and the heat storage member or a contact position of the heat storage member with the heat absorption member, and when the heating of the fixing device is started, The operation of the drive means is controlled so that the heat storage member and the heat absorption part are in contact with each other.

  Therefore, according to the image forming apparatus and the control method of the image forming apparatus of the present invention, it is possible to prevent the heat absorbing member from being overcooled and to prevent dew condensation and freezing.

Embodiment 1
An embodiment of the present invention will be described.

(1-1. Overall Configuration of Image Forming Apparatus 100)
FIG. 2 is a cross-sectional view showing a schematic configuration of an image forming apparatus (color image forming apparatus) 100 according to an embodiment of the present invention.

  As shown in this figure, the image forming apparatus 100 is a so-called tandem type printer in which four color visible image forming units 10 are arranged along a conveyance path of recording paper (recording material) P. Specifically, four sets of visible image forming units 10Y, 10M, 10C, and 10B are disposed along the conveyance path of the recording paper P that connects the supply tray 20 of the recording paper P and the fixing device 40, and conveying means. After the toner of each color is multiplex-transferred onto the recording paper P conveyed by 30, the toner is fixed by the fixing device 40 to form a full color image.

  The conveying means 30 has an endless conveying belt 33 that is stretched by a pair of driving rollers 31 and an idling roller 32 and that is rotated at a predetermined peripheral speed (355 mm / s in this embodiment). The recording paper P is electrostatically adsorbed on the belt and conveyed.

  Each of the visible image forming units 10 (10Y, 10M, 10C, and 10B) has a charging roller 12, a laser beam irradiation unit 13, a developing device 14, a transfer roller 15, and a cleaner 16 around the photosensitive drum 11. The developing unit 14 of each unit contains yellow (Y), magenta (M), cyan (C), and black (B) toners, respectively. Each visible image forming unit forms a toner image on the recording paper P through the following steps. That is, after the surface of the photosensitive drum 11 is uniformly charged by the charging roller 12, the surface of the photosensitive drum 11 is laser-exposed according to image information by the laser light irradiation unit 13 to form an electrostatic latent image. Thereafter, the electrostatic latent image on the photosensitive drum 11 is developed with toner by the developing device 14 to form a toner image, and the visualized toner image is transferred to which a bias voltage having a polarity opposite to that of the toner is applied. The image is sequentially transferred onto the recording paper P conveyed by the conveying means 30 by the roller 15. The developing device 14 is a developer such as a non-magnetic one-component developer (non-magnetic toner), a non-magnetic two-component developer (non-magnetic toner and carrier), and a magnetic developer (magnetic toner) (hereinafter also referred to as toner). ) To develop the electrostatic latent image to generate a toner image. The recording paper P to which the toner image has been transferred is peeled off from the transport belt 33 by the curvature of the drive roller 31 and then transported to the fixing device 40.

  The fixing device 40 applies heat and pressure to the recording paper P and the unfixed toner image on the recording paper, thereby fixing the unfixed toner image on the recording paper P and forming a robust image on the recording paper. Specifically, the fixing device 40 includes a fixing roller 41 and a pressure roller 42. The recording paper P conveyed from the visible image forming unit 10 is sent to a fixing nip N formed between the fixing roller 41 and the pressure roller 42. Further, the fixing roller 41 and the pressure roller 42 convey the recording paper P while sandwiching it. At this time, the toner image (unfixed image) on the recording paper P is melted by the heat of the peripheral surface of the fixing roller 41, and is pressed by the fixing roller 41 and the pressure roller 42 to be fixed to the recording paper P. Fix as a robust image.

  Then, the recording paper P after the fixing process of the toner image by the fixing device 40 is conveyed to a paper discharge tray (not shown) outside the image forming apparatus 100 and discharged. Thereby, the image forming process ends. A specific configuration of the fixing device 40 will be described later in detail.

  In addition, the image forming apparatus 100 includes a main control unit (control integrated circuit board or computer, not shown) that controls the operation of each unit included in the image forming apparatus 100. This main control unit is a user. The operation of each part of the image forming apparatus 100 is controlled in accordance with an instruction input from the computer, detection results of various sensors, and the like. In the present embodiment, the control unit controls the sheet conveying unit 30, the fixing roller 41, and the pressure roller 42 of the image forming apparatus 100 so that the recording sheet P is conveyed at a conveying speed (process speed, fixing speed) of 355 mm / S. Control etc. Thus, in the image forming apparatus 100, the copying speed (number of copies per minute) is 70 sheets / minute in A4 horizontal feed.

(1-2. Configuration of Fixing Device 40)
Next, the configuration of the fixing device 40 will be specifically described. FIG. 1 is a schematic diagram illustrating the configuration of the fixing device 40. As shown in this figure, the fixing device 40 includes, in addition to the fixing roller 41 and the pressure roller 42 described above, a heat pump 60, an external heating device 80, a control device 90, a belt moving device 101, a heating power supply unit 102, a rotational drive. The apparatus 103, the heat storage member moving apparatus 67, etc. are provided. If necessary, a web cleaning device for cleaning the surface of the fixing roller 41 may be further provided.

  The fixing roller 41 and the pressure roller 42 are pressed against each other with a predetermined load (here, 560 N), and a fixing nip N (a portion where the fixing roller 41 and the pressure roller 42 are in contact with each other between them, a width of 8 mm here) ) Is formed. Then, the recording paper P is conveyed while being sandwiched between these rollers by the fixing nip N, whereby the toner on the recording paper P is heated and melted, and pressure is applied to the melted toner and the recording paper P to add toner. The image is fixed on the recording paper P. When the recording paper P passes through the fixing nip N, the fixing roller 41 contacts the toner image forming surface of the recording paper P, while the pressure roller 42 is on the surface opposite to the toner image forming surface of the recording paper P. It comes to contact.

  The fixing roller 41 is a roller that rotates in the X direction shown in FIG. 1, and is a metal hollow cylindrical cored bar 41a, an elastic layer 41b that covers the outer peripheral surface of the cored bar 41a, and a mold release that covers the elastic layer 41b. It is composed of the layer 41c. Moreover, the heat radiating part 66 of the heat pump 60 described later is disposed inside the cored bar 41a. The heat radiating portion 66 is composed of a pipe (heat medium pipe) passing through the inside (hollow portion) of the cored bar 41a, and a fluid as a heat medium passes through the inside. As a result, in the condenser 62 of the heat pump 60, high temperature heat is supplied to the heat medium flowing in the pipe of the heat radiating section 66, the temperature of the heat medium rises, and the heat medium is conveyed into the fixing roller 41 and fixed. The inner peripheral surface (core metal 41) of the roller 41 is heated, and the surface of the fixing roller 41 is further heated by heat conduction.

  In addition, as the core metal 41a and the heat radiating part 66, it is preferable to use a material having high thermal conductivity. For example, a metal such as iron, stainless steel, aluminum, copper, or an alloy thereof can be used. In addition, you may make the pipe which comprises the thermal radiation part 66 function as the metal core 41a. However, in this case, it is necessary to appropriately seal both ends of the pipe so that the heat medium flowing inside the heat radiating portion 66 does not leak to the outside due to the rotation of the fixing roller 41.

  The elastic layer 41b is made of silicon rubber or fluoro rubber, the release layer 41c is made of fluorine resin such as PFA (a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether) or PTFE (polytetrafluoroethylene), and the like. Hybrid materials are suitable.

  Further, the external heating belt 83 of the external heating device 80 and the thermistor 43 are in contact with the outer peripheral surface of the fixing roller 41. As will be described in detail later, the control device 90 controls the operation of the heat pump (first heat source) 60 and the external heating device (second heat source) 80 based on the temperature detection result of the thermistor 43 and the like. The temperature of the surface is heated to a predetermined temperature (here, 190 ° C.).

  The pressure roller 42 includes a metal hollow cylindrical cored bar 42a, an elastic layer 42b that covers the outer peripheral surface of the cored bar 42a, and a release layer 42c that covers the elastic layer 42b. The metal core 42a is made of a metal such as aluminum, iron, stainless steel, or aluminum, or an alloy thereof. The elastic layer 42b is made of heat-resistant silicon rubber. The release layer 42c is made of a PFA tube. The material of the release layer 42c may be any material as long as it is excellent in heat resistance and durability and has excellent release properties with respect to the toner. In addition to PFA, a fluorine-based material such as PTFE may be used.

  The pressure roller 42 is pressed against the fixing roller 41 with a predetermined load (here, 560 N) by an elastic member (spring) (not shown). As a result, a fixing nip N is formed between the peripheral surface of the fixing roller 41 and the peripheral surface of the pressure roller 42. Further, the pressure roller 42 is driven by the rotation of the fixing roller 41 due to the frictional force with the fixing roller 41 and rotates in the opposite direction to the fixing roller 41 (the movement direction of both roller surfaces in the fixing nip portion is the same). In the present embodiment, the pressure roller 42 is configured to rotate following the fixing roller 41, but is not limited thereto, and may be configured to be rotationally driven by a rotational driving unit different from the fixing roller 41.

  A heater lamp 45 for heating the pressure roller 42 from the inside is provided inside the pressure roller 42. The heater lamp 45 has a heat generation width over the entire width of the pressure roller 42, and the rated heating power is 450W.

  The thermistor 44 is in contact with the outer peripheral surface of the pressure roller 42, and the temperature detection result of the thermistor 44 is transmitted to the control device 90. The control device 90 controls the power supplied from the heating power supply unit 102 to the heater lamp 45 based on the temperature detection result of the thermistor 44, etc., thereby controlling the temperature of the peripheral surface of the pressure roller 42 to a predetermined temperature. It is supposed to be.

  The external heating device 80 includes a first support roller 81, a second support roller 82, an external heating belt 83, and a belt moving device 101.

  The external heating belt 83 is stretched around the support rollers 81 and 82 so that the back surface (inner peripheral surface) side is in contact with the peripheral surfaces of the support rollers 81 and 82. Further, heater lamps 84 and 85 are provided inside the support rollers 81 and 82, and thermistors 86 and 87 are provided at positions where they contact the outer peripheral surface of the contact area of the external heating belt 83 with the support rollers 81 and 82. Is provided. The heater lamps 84 and 85 have a rated power of 475 W and are connected to the heating power supply unit 102 in parallel. Further, the temperature control unit 92 of the control device 90 controls the power supplied from the heating power supply unit 102 to the heater lamps 84 and 85 in accordance with the temperature detection result of the thermistors 86 and 87. Accordingly, the heater lamps 84 and 85 emit light according to the supplied electric power to heat the inner peripheral surfaces of the support rollers 81 and 82, and the external heating belt 83 is indirectly heated via the support rollers 81 and 82. It has come to be. In the present embodiment, the temperature of the outer peripheral surface of the external heating belt 83 during the printing operation is heated to a predetermined temperature (220 ° C. here).

  The external heating belt 83 is pressed against the fixing roller 41 with a predetermined pressing force (here, 40 N) by the belt moving device 101 described later, and is heated between the fixing roller 41 and a heating nip (here, circumferential). Direction width 18 mm) is formed. The external heating belt 83 is rotated by the fixing roller 41 when the fixing roller 41 is rotated, and the support rollers 81 and 82 are also rotated by the rotation of the external heating belt 83. It is configured as follows.

  The external heating belt 83 is a belt member in which a fluororesin in which PTFE and PFA are blended as a release layer is coated with a thickness of 20 μm on the surface of a base material of polyimide (product name: Upilex S) having a thickness of 90 μm. It is. The inner diameter of the external heating belt 83 is 30 mm at room temperature. The external heating belt 83 has a width (length in the axial direction) of 320 mm, which is substantially the same as the width of the fixing surface of the fixing roller 41.

  The support rollers 81 and 82 are formed by coating a surface of an aluminum cored bar having a thickness of 2 mm with a fluororesin blended with PTFE and PFA to a thickness of 20 μm. The outer diameter of both support rollers 81 and 82 is 15 mm. The distance between the shafts of the support roller 81 and the support roller 82 is fixed at 23.0 mm. The configuration of the support rollers 81 and 82 is not limited to this. For example, a heat-resistant resin such as polyimide or a surface of a hollow cylindrical substrate made of a metal material such as stainless steel or nickel is used as a release layer. Alternatively, a two-layer roller formed with a synthetic resin material (for example, a fluororesin such as PFA or PTFE, which is used alone or in combination) having excellent properties and releasability may be used. In order to reduce the shifting force (force acting in the main scanning direction) generated in the external heating belt 83, the surface of the support rollers 81 and 82 and / or the inner peripheral surface of the external heating belt 83 is coated with a fluorine resin or the like. May be applied.

  The belt moving device 101 moves the relative positions of the support rollers 81 and 82 and the external heating belt 83 with respect to the fixing roller 41 in accordance with instructions from a belt movement control unit 91 provided in the control device 90.

  FIG. 3A is a cross-sectional view showing a state in which the external heating belt 83 is arranged at the first position where the belt moving device 101 contacts the fixing roller 41 with a predetermined load determined as a load at the time of image formation. 3B is a cross-sectional view illustrating a state in which the external heating belt 83 is disposed at the second position where the pressing force against the fixing roller 41 is smaller than that at the first position. 4A is a top view illustrating the configuration of the belt moving device 101, and FIG. 4B is a side view illustrating the configuration of the support roller 82, the external heating belt 83, and the belt regulating member 122.

  When the fixing roller 41 is rotationally driven with the external heating belt 83 in the first position (the external heating belt 83 is in pressure contact with the fixing roller 41), the external heating belt 83 is driven and rotated by the fixing roller 41. As a result, a portion of the external heating belt 83 heated by the support roller 81.82 moves to a contact portion with the fixing roller 41 so that the surface of the fixing roller 41 can be heated. On the other hand, in the state where the external heating belt 83 is in the second position, the external heating belt 83 and the fixing roller 41 are in contact with each other. However, the contact pressure is small and the frictional force is small. The belt 83 does not rotate. Therefore, in this state, the heat of the support rollers 81 and 82 is not supplied to the fixing roller 41.

  3A and 3B, the belt moving device 101 includes a side frame 111, an arm 112, an eccentric cam 113, a fulcrum (fulcrum member) 114, a fulcrum (fulcrum member) 115, and a coil spring 116. I have.

  The side frames 111 are provided at both ends of the support rollers 81 and 82, respectively, and rotatably support the support rollers 81 and 82 via bearings 117 and 118 as shown in FIG. is there. The bearings 117 and 118 are fixed to the side frame 111 at a predetermined inter-axis distance, so that the parallelism between the support roller 81 and the support roller 82 is ensured. In the present embodiment, the parallelism tolerance between the support roller 81 and the support roller 82 is 100 μm or less. The side frame 111 is pivotally supported by the arm 112 at a fulcrum 114 so as to be rotatable in a direction substantially perpendicular to the axial direction of the support rollers 81 and 82.

  The arm 112 is rotatably supported by a fulcrum 115 fixed to the frame of the fixing device 40 (not shown), and is urged in a direction in contact with the fixing roller 41 by a coil spring 116 with the fulcrum 115 as an axis. As a result, in FIG. 3A, the support rollers 81 and 82 pivotally supported on the side frame 111 are brought into pressure contact with the fixing roller 41 with equal loads.

  The eccentric cam 113 is provided in contact with the vicinity of the end of the arm 112. The eccentric cam 113 is rotationally driven by the control device 90 controlling driving means such as a motor (not shown).

  As a result, the control device 90 (movement control unit 90c) controls the drive means to rotate the eccentric cam 113 and move the support rollers 81 and 82 to the first position as shown in FIG. The eccentric cam 113 is rotated 180 degrees therefrom, and the support rollers 81 and 82 can be moved to the second position as shown in FIG. 3B.

  As shown in FIGS. 4A and 4B, belt regulating members (shift regulating members) 121 and 122 are provided between the support rollers 81 and 82 and the bearings 117 and 118, respectively. . When the external heating belt 83 meanders, the belt regulating members 121 and 122 abut against the belt end portion and rotate to regulate the axial deviation of the support rollers 81 and 82 of the external heating belt 83. At the same time, the end of the external heating belt 83 is prevented from being worn or cracked by sliding with the bearings 117 and 118.

  The belt regulating members 121 and 122 are installed so as to be rotatable with respect to the support rollers 81 and 82 and to be movable independently of the support rollers 81 and 82 in the axial direction of the support rollers 81 and 82. ing.

  By the way, the amount of change in the heat supply amount to the fixing roller 41 due to the difference in the positions of the support rollers 81 and 82 and whether or not the external heating belt 83 is driven to rotate by the fixing roller 41 are determined by the relationship between the external heating belt 83 and the fixing roller 41. The contact width and the pressure contact force, the ease of rotation of the external heating belt 83 (rotational resistance), and the like vary. Since these depend on the surface material of the contact part, temperature, peripheral speed, belt peripheral length and inter-axis distance, fulcrum position, and belt curl, adjust the separation length appropriately in the assembled state. It is desirable to decide. According to the belt moving device 101 configured as described above, since the side frame 111 with the positions of the support rollers 81 and 82 fixed is moved, the support rollers 81 and 82 and the external heating belt 83 are integrated with each other. In this state, it can be quickly separated from the fixing roller 41.

  The heating power supply unit 102 is connected to the heater lamps 45, 84, and 85, and supplies power for heating to these heater lamps. Then, the temperature control unit 92 provided in the control device 90 determines the power supply amount from the heating power supply unit 102 to each heater lamp based on the temperature detection results of the thermistors 43, 44, 86, and 87, the image forming mode, and the like. By switching, the heat generation amount of each heater lamp is controlled, and the temperature of the external heating belt 83 and the pressure roller 42 is controlled to be a predetermined temperature.

  The rotation driving device 103 rotates the fixing roller 41, and includes, for example, a motor. The operation of the rotation drive device 103 is controlled by a rotation control unit 93 provided in the control device 90.

(1-3. Configuration of Heat Pump 60)
Next, the heat pump 60 will be described. FIG. 5 is a block diagram showing a schematic configuration of the heat pump 60. FIG. 6 is a TS diagram (a graph showing the relationship between temperature change and entropy change) showing the operation of the heat pump 60.

  As shown in FIG. 5, the heat pump 60 is a heat pump of a vapor compression refrigeration cycle including a compressor 61, a condenser 62, an expansion valve 63, and an evaporator 64. The heat pump 60 includes a heat absorption unit 65 and a heat radiation unit 66.

  The heat absorption unit 65 absorbs heat released from the recording paper P after being subjected to fixing processing by the fixing device 40, and supplies the absorbed heat to the evaporator 64. It is provided on the downstream side in the transport direction of P and on the upper side in the vertical direction with respect to the transport path of the recording paper P. The details of the heat absorption part 65 will be described later.

  The evaporator 64 supplies the amount of heat Q2 absorbed by the heat absorption unit 65 to the working fluid, and evaporates the working fluid to dry saturated steam A. The compressor 61 compresses the working fluid (dry saturated steam A) evaporated by the evaporator 64 to a pressure equal to or higher than the saturated steam pressure with respect to a desired temperature in the heat radiating unit 66 to send the superheated saturated steam B to the condenser 62. . The superheated saturated steam B sent to the condenser 62 supplies (releases) the heat quantity Q1 to the fixing roller 41 via the heat radiating section 66. As a result, the working fluid is cooled and liquefied to become the saturated liquid C. This saturated liquid C is sent to the expansion valve 63, isenthalpy-expanded by the expansion valve 63, becomes wet steam D, is sent to the evaporator 64, and the above heat cycle is repeated.

  The heat radiating unit 66 includes a pipe (heat medium pipe) passing through the inside of the fixing roller 41 as described above. Then, heat is exchanged between the working fluid of the heat pump 60 and the heat medium in the pipe to heat the heat medium, and the heat medium is supplied to the inside of the fixing roller 41, whereby the heat of the working fluid of the heat pump 60 is supplied to the fixing roller. 41 is supplied. Note that the working fluid of the heat pump 60 may pass through a pipe passing through the inside of the fixing roller 41, and heat exchange may be performed between the working fluid of the heat pump 60 and the fixing roller 41.

  By using this heat pump 60, the heat released from the recording paper P is absorbed by the heat absorbing unit 65, and heat is supplied to the heat radiating unit 66 having a temperature higher than that of the heat absorbing unit 65, and used for heating the fixing roller 41. Can do. Thereby, compared with the case where the fixing roller 41 is heated only by heating means (halogen heater or the like) that is heated by electric power, the heating electric power can be reduced.

(1-4. Configuration of endothermic portion 65)
Next, the structure of the heat absorption part 65 with which the heat pump 60 is provided is demonstrated. 7A and 7C are plan views of the heat absorbing unit 65, and FIGS. 7B and 7D are side views of the heat absorbing unit 65. FIG. 7A and 7B show a case where the heat storage member 73 is moved to a position (first position) where the contact area between the heat storage member 73 and the heat absorption member 72 provided in the heat absorption unit 65 is increased. 7C and 7D show the case where the heat storage member 73 is moved to a position (second position) where the contact area between the heat storage member 73 and the heat absorption member 72 is smaller than the first position. Is shown.

  As shown in these drawings, the heat absorption unit 65 includes a heat medium pipe 71, a heat absorption member 72, a heat storage member 73, a temperature sensor 74, a heat absorption member fan (first blower) 75, and a heat storage member fan (second blower). Instrument) 76 and a temperature sensor 77. 7B and 7D, the heat absorbing member 72 and the heat storage member 73 are disposed at positions facing the conveyance path of the recording paper P. Further, the heat absorbing member 72 is disposed upstream of the heat storage member 73 in the recording paper conveyance direction. A heat absorbing member fan 75 is disposed between the heat absorbing member 72 and the recording paper transport path, and a heat storage member fan 76 is disposed between the heat storage member 73 and the recording paper transport path.

  The heat absorbing member fan 75 generates an air flow from the recording paper conveyance path side to the heat absorption member 72 side, and the heat storage member fan 76 generates an air flow from the recording paper conveyance path side to the heat storage member 73 side. is there. The air heated by the heat radiation from the recording paper P after the fixing process is sent to the heat absorption member 72 and the heat storage member 73 by these fans.

  A fluid serving as a heat medium flows inside the heat medium pipe 71. Then, the heat absorbed in the heat absorbing section 65 is conveyed to the evaporator 64 by this heat medium and used for heating the working fluid in the evaporator 64. The material of the heat medium pipe 71 is not particularly limited, but a material having high thermal conductivity is preferably used, and for example, a metal such as copper or aluminum can be used.

  The heat absorbing member 72 is composed of a large number of disk-shaped fins attached around the heat medium pipe 71, absorbs heat radiated from the recording paper P, and transmits the heat to the heat medium pipe 71. Heat the heating medium. The material of the heat absorbing member 72 is preferably a material having high thermal conductivity, and for example, a metal such as copper or aluminum can be used.

  The heat storage member 73 has a small amount of heat input from the outside to the heat absorbing member 72 immediately after the image forming apparatus is turned on (immediately after startup), immediately after the start of the image forming operation, or when the image forming operation has not been performed for a predetermined time or more. Sometimes, the heat absorbing member 72 is disposed at the first position to prevent the heat absorbing member 72 from being overcooled by a low-temperature heat medium and freezing or condensing. The heat storage member 73 also has a function of transmitting heat absorbed from the surrounding air to the heat absorption member 72 and heating the heat absorption member 72 efficiently.

  As shown in FIGS. 7A and 7C, the heat storage member 73 includes a shaft portion 73a and a large number of fin portions 73b attached around the shaft portion 73a. The fin section 73b has a substantially U-shaped cross section perpendicular to the extending direction of the heat medium pipe 71 so that the fin section 73b and the heat medium pipe 71 do not interfere when moved to the first position. . Further, the fins constituting the fin portion 73b are inserted between the fins constituting the heat absorbing member 72, and the fins constituting the fin portion 73b and the fins constituting the heat absorbing member 72 are in contact with each other. It is like that.

  The material of the heat storage member 73 is not particularly limited. For example, stainless steel, copper, iron, tin, nickel, or an alloy containing one or more of these materials can be used. In order to appropriately prevent overcooling of the heat absorbing member 72, the heat capacity of the heat storage member 73 is preferably sufficiently larger than the heat capacity of the heat absorbing member 72. The heat storage member 73 is preferably made of a material having a larger specific heat than the heat absorption member 72 in order to increase the heat capacity and suppress an increase in the apparatus size.

  The temperature sensor 74 measures the temperature at the position where the heat storage member 73 contacts the heat absorbing member 72 at the first position described above, and transmits the measurement result to the control device 90. In the present embodiment, the temperature sensor 74 is attached to the back surface of the fin of the heat storage member 73 in contact with the fin of the heat absorbing member 72. The configuration of the temperature sensor 74 is not particularly limited as long as the temperature of the heat storage member 73 can be appropriately measured. For example, a thermistor, a thermocouple, or the like can be used.

  The temperature sensor (second temperature sensor) 77 measures the air temperature in the vicinity of the heat absorbing member 72 and transmits the measurement result to the control device 90. In the present embodiment, the temperature of the air between the fins constituting the heat absorbing member 72 is measured by the temperature sensor 77.

  The heat storage member moving device 67 moves the relative position of the heat storage member 73 with respect to the heat absorption member 72 in accordance with an instruction from the heat storage member movement control unit 95 provided in the control device 90. The configuration of the heat storage member moving device 67 is not particularly limited as long as the position of the heat storage member 73 can be moved. For example, a conventionally known moving mechanism such as a crank mechanism or a solenoid can be used. it can.

(1-5. Configuration of Control Device 90)
As shown in FIG. 1, the control device 90 is a control integrated circuit board including a belt movement control unit 91, a temperature control unit 92, a rotation control unit 93, a heat pump drive control unit 94, and a heat storage member movement control unit 95. is there. The control device 90 may be provided in the main control unit of the image forming apparatus 100 described above, provided separately from the main control unit, and connected to the main control unit so that signals can be transmitted. Also good.

  The belt movement control unit 91 is connected to the belt moving device 101, and controls the operation of the eccentric cam 113 provided in the belt moving device 101, thereby fixing the support rollers 81 and 82 provided in the external heating device 80 and fixing. The amount of heat supplied from the external heating device 80 to the fixing roller 41 is controlled by controlling the relative position to the roller 41 and changing the contact width (heating nip width) between the external heating belt 83 and the fixing roller 41.

  Specifically, the belt movement control unit 91 moves the support rollers 81 and 82 to the second position immediately after the start of the image forming operation, thereby reducing the contact area between the external heating belt 83 and the fixing roller 41. As a result, it is possible to prevent the heat supply from the external heating belt 83 from becoming excessive and the temperature of the fixing roller 41 from becoming higher than the set temperature. That is, immediately after the start of the image forming operation, the fixing roller 41 rotates to make the circumferential temperature distribution uniform, but the recording paper P does not pass through the fixing nip N, so the fixing roller 41 takes heat to the recording paper P. It will never be. If the support rollers 81 and 82 are in the first position in this state, the heat supply from the external heating belt 83 becomes excessive, and the temperature of the fixing roller 41 becomes higher than the set temperature. Therefore, by moving the support rollers 81 and 82 to the second position, the amount of heat supplied from the external heating device 80 to the fixing roller 41 can be quickly changed, and an excessive temperature rise of the fixing roller 41 can be prevented.

  Further, the belt movement control unit 91 moves the support rollers 81 and 82 to the first position according to the timing when the recording paper P reaches the fixing nip after starting the image forming operation, and the external heating belt 83 and the fixing roller. The contact area with 41 is increased. As a result, the heat supplied from the external heating belt 83 to the fixing roller 41 can be quickly replenished by the fixing roller 41 by the recording paper P. Therefore, for example, even when continuous paper is passed, The surface temperature can be accurately controlled and kept within a predetermined temperature range.

  The position control method of the support rollers 81 and 82 is not limited to this. For example, the temperature of the fixing roller 41 does not reach the predetermined temperature or reaches the predetermined temperature only by the heat supplied from the heat pump 60. If it takes time to do so, the support rollers 81 and 82 are moved to the first position, the contact area between the external heating belt 83 and the fixing roller 41 is increased, and the fixing roller 41 is quickly heated. You may do it.

  The temperature control unit 92 is connected to the thermistors 43, 44, 86, and 87 and the heating power supply unit 102. The heating power supply unit 102 is connected to the heater lamps 45, 84, and 85, and supplies power for heating to these heater lamps. Then, the temperature control unit 92 switches the supply power from the heating power supply unit 102 to each heater lamp based on the temperature detection results of the thermistors 43, 44, 86, and 87, the image forming mode, etc. Is controlled so that the temperature of the external heating belt 83, the fixing roller 41, and the pressure roller 42 is set to a predetermined temperature.

  The rotation control unit 93 is connected to a rotation driving device 103 for driving the fixing roller 41 to rotate. The rotation control unit 93 controls the rotation speed of the fixing roller 41 by controlling the operation of the rotation driving device 103.

  The heat pump drive control unit 94 controls operations of the compressor 61, the condenser 62, the expansion valve 63, and the evaporator 64 provided in the heat pump 60.

  The heat storage member movement control unit 95 controls the operation of the heat storage member moving device 67 and changes the relative position of the heat storage member 73 with respect to the heat absorption member 72. In addition, in this embodiment, although the relative position of the heat storage member 73 and the heat absorption member 72 is changed by changing the position of the heat storage member 73 by the heat storage member moving apparatus 67, it is not restricted to this, The heat storage member Any configuration may be used as long as the relative position of the heat absorbing member 72 is changed by changing the position of at least one of the heat absorbing member 73 and the heat absorbing member 72.

(1-6. Operation of Fixing Device 40)
Next, the operation at the time of image formation in the fixing device 40 will be described. FIG. 8 is a flowchart showing an operation flow of the fixing device 40.

  When an image formation instruction is input from the user via an operation panel (not shown) or the like, the rotation control unit 93 drives the rotation driving device 103 to start rotation of the fixing roller 41 (S1). Further, the temperature control unit 92 controls the heating power supply unit 102 to supply power to the heater lamp 45 of the pressure roller 42 to start heating the pressure roller 42 (S2). Further, the heat pump drive control unit 94 controls each part of the heat pump 60 to drive the heat pump 60 (S3). Thereby, heating of the fixing roller 41 is started.

  At this time, the position of the external heating belt 83 is set to the second position. The position of the heat storage member 73 is set to the first position. That is, when the image forming apparatus 100 is activated and when the image forming operation is started, the heat storage member 73 is disposed at the first position where the contact area with the heat absorbing member 72 is larger than the second position. Further, the temperature controller 92 maintains the surface temperature of the pressure roller 42 at a predetermined temperature based on the temperature detection result of the thermistor 44 until the image forming operation is finished after the heating of the pressure roller 42 is started. In addition, the power supplied to the heater lamp 45 is controlled.

  Thereafter, the heat storage member movement control unit 95 is set to a first set temperature T1 (here, T1 = 4 ° C.) in which the temperature of the heat storage member 73 is preset based on the temperature detection result of the temperature sensor 74 provided in the heat absorption unit 65. It is judged whether it is less than () (S4). If the position of the heat storage member 73 is the second position at this time, the process may proceed to S7 without performing the processes of S4 and S5.

  When it is determined in S4 that the temperature of the heat storage member 73 is not lower than the first set temperature T1, the heat storage member movement control unit 95 performs heat absorption based on the temperature detection result of the temperature sensor 77 provided in the vicinity of the heat absorption member 72. It is determined whether the temperature around the member 72 is equal to or higher than a preset third set temperature T3 (S5).

  When it is determined in S4 that the temperature of the heat storage member 73 is lower than the first set temperature T1, and in S5, a third set temperature T3 (here, T3 = 40 ° C.) in which the temperature around the heat absorbing member 72 is set in advance. ) When it is determined that the above is true, the heat storage member movement control unit 95 controls the heat storage member moving device 67 to move the heat storage member 73 to the second position (S6).

  In the present embodiment, as shown in FIGS. 7C and 7D, the heat storage member 73 and the heat absorption member 72 are not completely separated from each other in the second position, but the heat storage is performed in the second position. A part of the fins of the member 73 and a part of the fins of the heat absorbing member 72 are in contact with each other. Thus, when the heat storage member 73 is moved again to the first position, it is possible to prevent the tip of the fin of the heat storage member 73 and the tip of the fin of the heat absorption member 72 from interfering with each other to be deformed or damaged. It has become. However, not limited to the above configuration, for example, when interference between the fin tips of the heat storage member 73 and the fin tips of the heat absorption member 72 is not a problem, the heat storage member 73 and the heat absorption member 72 at the second position. You may make it completely separate.

  On the other hand, when it is determined in S5 that the temperature around the heat absorbing member 72 is not equal to or higher than the preset third set temperature T3, the heat storage member movement control unit 95 detects the temperature of the temperature sensor 74 provided in the heat absorbing unit 65. Based on the result, it is determined whether or not the temperature of the heat storage member 73 is lower than a preset second set temperature T2 (here, T2 = T1 + 10 = 14 ° C.) (S7). In addition, when the position of the heat storage member 73 is the first position at this time, the process of S9 may be performed without performing the processes of S7 and S8.

  When it is determined in S7 that the temperature of the heat storage member 73 is equal to or higher than the second set temperature T2, the heat storage member movement control unit 95 controls the heat storage member moving device 67 to move the heat storage member 73 to the first position (S8). ).

  Thereafter, the temperature control unit 92 determines whether or not the temperature of the surface of the fixing roller 41 has reached a predetermined temperature range set as a temperature at the time of image formation based on the temperature detection result of the thermistor 43 (S9). ).

  When it is determined that the temperature of the fixing roller 41 has not reached the predetermined temperature range, the belt movement control unit 91 controls the belt moving device 101 to move the external heating belt 83 to the first position (S10). The control unit 92 controls the heating power supply unit 102 to supply power for heating the fixing roller 41 to a predetermined temperature range to the heater lamps 84 and 85 (S11). As a result, the surface of the fixing roller 41 is heated via the external heating belt 83. Thereafter, the processing after S4 is continued while the heating of the fixing roller 41 is continued. Note that the external heating belt 83 is moved to the first position and heated in a period after the image forming apparatus 100 is turned on or after the image forming operation is started and before the recording paper P is conveyed to the fixing nip N. Instead, the fixing roller 41 may be heated by the heat pump 60.

  On the other hand, if it is determined in S9 that the temperature of the fixing roller 41 has reached the predetermined temperature range, the temperature control unit 92 informs the main control unit of the image forming apparatus 100 that the temperature of the fixing roller 41 is within the predetermined temperature range. To be notified. Accordingly, the main control unit of the image forming apparatus 100 controls the operation of each unit, and the image forming operation on the recording paper P is executed (S12). As a result, the recording paper P to which the unfixed toner has been transferred is conveyed to the fixing nip N.

  Thereafter, the main control unit or the control device 90 determines whether or not to continue the image forming operation, that is, whether or not to perform the image forming operation on another recording sheet (S13). This determination may be made, for example, by determining whether image formation has been performed on the number of recording sheets instructed by the user. When the image forming operation is continued, the processes of S10 and S11 are performed, and the processes after S4 are performed again.

  On the other hand, when it is determined in S12 that the image forming operation is finished, the heat storage member movement control unit 95 controls the heat storage member moving device 67 to move the heat storage member 73 to the first position (S14). Moreover, the heat pump drive control part 94 stops the drive of the heat pump 60 (S15). Further, the temperature control unit 92 controls the heating power supply unit 102 to stop energization of the heater lamps 45, 84, and 85 (S16). As a result, the operation of the fixing device 40 ends.

  As described above, in the image forming apparatus 100 according to the present embodiment, the heat released from the recording paper P after the fixing process is absorbed by the heat absorbing unit 65 and is heated to the high temperature by the heat pump 60 and used to heat the fixing roller 41. Thereby, the energy for heating the fixing roller 41 can be reduced as compared with the case where the fixing roller 41 is heated only by the heating unit that is heated by being supplied with electric power. Further, exhaust heat from the image forming apparatus 100 can be reduced. Further, it is possible to prevent the temperature of each member (each unit, electrical component, etc.) in the image forming apparatus 100 from being raised, and it is possible to prevent the operation of each member from becoming unstable due to the temperature rise. An image can be formed stably.

  In the present embodiment, immediately after the image forming apparatus is activated or immediately after the start of the image forming operation, the heat storage member 73 provided in the heat absorbing unit 65 is moved to the first position where the contact area with the heat absorbing member 72 is larger than the second position. Deploy.

  As a result, the heat quantity of the heat storage member 73 and the heat quantity of the heat absorption member 72 are supplied to the evaporator 64 of the heat pump 60 (the heat absorption member 72 by the low-temperature heat medium passing through the heat medium pipe 71 of the heat absorption part 65). For example, even when the amount of heat input from the outside to the heat absorbing member 72 before the image forming operation is small, the heat absorbing member 72 is cooled by the evaporator 64 of the heat pump 60. Can be prevented from being overcooled and causing freezing and condensation.

  Moreover, in this embodiment, when the temperature of the heat storage member 73 falls below 1st setting temperature T1, the heat storage member 73 is moved to the 2nd position where the contact area with respect to the heat absorption member 72 is smaller than a 1st position. As a result, the contact area between the heat absorbing member 72 and the surrounding air and the contact area between the heat storage member 73 and the surrounding air can be increased, and the amount of heat absorbed from the surroundings of these two members can be increased.

  When the temperature of the heat storage member 73 becomes lower than the first set temperature T1, the operation of the heat pump 60 may be stopped in order to prevent the heat storage member 73 and the heat absorption member 72 from freezing and dew condensation. . In this case, the temperature control unit 92 controls the heating power supply unit 102 to supply power to the heater lamps 84 and 85 to heat the support rollers 81 and 82 and the external heating belt 83, and the belt movement control unit 91 moves the belt. The fixing roller 41 may be heated by the external heating device 80 by controlling the operation of the apparatus 101 and moving the support rollers 81 and 82 to the first position.

  In the present embodiment, the first set temperature T1 is set to 4 ° C., but the present invention is not limited to this. However, the first set temperature T1 is higher than 0 ° C. in order to appropriately prevent the heat absorption member 72 from freezing and dew condensation, and is higher than the in-machine temperature of the image forming apparatus 100 or the temperature around the image forming apparatus 100 (room temperature). Preferably it is low. By making 1st preset temperature T1 higher than 0 degreeC, it can prevent that the water | moisture content in air freezes on the surface of the thermal storage member 73. FIG. Thereby, it can prevent that ice adheres to the surface of the heat absorption member 72 and the heat storage member 73, and inhibits heat exchange with air. Moreover, it can prevent that the heat storage member 73 and the heat absorption member 72 adhere | attach with ice, and the movement of the heat storage member 73 is inhibited. Further, by making the first set temperature T1 lower than the in-machine temperature, heat can be absorbed from the air in the machine by the heat storage member 73 in a portion separated from the heat absorbing member 72. Thereby, when the said part is made to contact the heat absorbing member 72 after that, the amount of heat supplied to the heat absorbing member 72 can be increased. The in-machine temperature of the image forming apparatus 100 may be detected by a temperature sensor 134 provided at a position distant from the fixing device 40 as shown in FIG.

  Moreover, in this embodiment, when the temperature of the heat storage member 73 becomes 2nd preset temperature T2 or more, the heat storage member 73 is moved to the 1st position where the contact area with respect to the heat absorption member 72 is larger than a 2nd position. Alternatively, the heat storage member 73 may be moved to the first position when the temperature of the heat storage member 73 is equal to or higher than the second set temperature T2 and higher than the temperature of the heat absorption member 72. Thereby, the heat quantity which the heat storage member 73 has can be supplied to the heat absorption member 72, and the heat input amount to the heat pump 60 can be increased.

  In the present embodiment, when the temperature around the heat absorbing member 72 becomes equal to or higher than the third set temperature T3, the heat storage member 73 is moved to the second position.

  When the temperature of the air in the vicinity of the heat absorbing member 72 is high, the amount of heat absorbed from the air to the heat absorbing member 72 increases. For this reason, even if the heat storage member 73 is moved to the second position to reduce the contact area (heat transfer area) to the heat absorption member 72 (or even if the heat storage member 73 is separated from the heat absorption member 72), the fixing roller 41 is moved. The amount of heat required for appropriate heating can be absorbed by the heat absorbing member 72. Moreover, since the amount of heat transfer from the heat storage member 73 to the heat absorption member 72 can be reduced, the heat storage amount of the heat storage member 73 can be increased and the heat storage member 73 can be held in a high temperature state. Therefore, even if the temperature of the air in the vicinity of the heat absorbing member 72 decreases after the image forming operation ends, the heat storage member 73 can be kept in a high temperature state for a long time. As a result, the amount of heat stored in the heat storage member 73 at the start of the next image forming operation can be used for heating the fixing roller 41, and the power required for heating the fixing roller 41 can be further reduced. Further, the temperature of the fixing roller 41 can be raised to a predetermined temperature in a short time.

  The third set temperature T3 is preferably 30 ° C. (room temperature) or higher. The third set temperature T3 is preferably lower than the temperature of the recording paper (usually about 100 ° C.) immediately after passing through the fixing nip.

  Further, in the present embodiment, the heat absorbing member 72 and the heat storage member 73 are opposed to the conveyance path of the recording paper P, and the heat absorption member 72 is disposed upstream of the heat storage member 73 in the recording paper conveyance direction.

  As described above, the heat absorbing member 72 is arranged on the upstream side of the heat storage member 73 in the conveyance direction of the recording paper P, so that the heat absorption member 72 is arranged on the downstream side of the recording paper P in the conveyance direction. The amount of heat absorbed by the heat absorbing member 72 can be increased. Thereby, since the amount of heat input to the heat pump 60 can be increased, the heat utilization efficiency can be further increased.

  Further, the moving direction of the heat storage member 73 from the first position to the second position is substantially parallel to the recording paper conveyance direction. Therefore, even when the heat storage member 73 is in the first position or the second position, the heat radiated from the recording paper P is efficiently absorbed by the heat absorption member 72 and the heat storage member 73. Can do.

  In addition, that the temperature of the heat absorption member 72 and the heat storage member 73 falls below 1st preset temperature T1 means that the temperature of the thermal radiation part 66 of the heat pump 60 is high temperature. Therefore, in this state, the temperature of the fixing roller 41 is sufficiently raised, and the image forming operation can be executed. Accordingly, since the amount of heat released from the recording paper P after the fixing process is increased, the amount of heat supplied to the heat absorbing member 72 and the heat storage member 73 is also increased. Therefore, by moving the heat storage member 73 to the second position, the heat transfer area between the heat absorption member 72 and the air around the heat storage member 73 is increased, and the heat radiated from the recording paper P is efficiently absorbed. Can do.

  In the present embodiment, a heat absorbing member fan 75 that generates an air flow from the recording paper transport path side to the heat absorbing member 72 side is provided between the recording paper transport path and the heat absorbing member 72. Thereby, the heat released from the recording paper P can be efficiently absorbed by the heat absorbing member 72. Therefore, the energy use efficiency can be increased and the power required for heating the fixing roller 41 can be more effectively reduced.

  Similarly, a heat storage member fan 76 that generates an airflow from the recording paper transport path side to the heat storage member 73 side is provided between the recording paper transport path and the heat storage member 73. As a result, the heat released from the recording paper P can be efficiently absorbed by the heat storage member 73. Therefore, the energy use efficiency can be increased and the power required for heating the fixing roller 41 can be more effectively reduced.

  In the present embodiment, as a heating unit for heating the fixing roller 41, a heat radiating portion (first heat source) 66 of the heat pump 60 and an external heating device (second heat source) 80 including heater lamps 84 and 85 are provided. It has. Thereby, the fixing roller 41 can be efficiently heated by these two heat sources. For example, when the room temperature is low or when the temperature of the fixing roller 41 has not risen to a predetermined temperature immediately after startup, the temperature around the heat absorbing member 72 is low, and the amount of heat that can be absorbed from the heat absorbing member 72 is reduced. Therefore, in such a case, it takes a long time to raise the temperature of the fixing roller 41 to the temperature during the fixing operation by the heat pump 60. In contrast, in the present embodiment, in addition to the heat pump 60, an external heating device 80 that heats the fixing roller 41 by being supplied with electricity is provided. Therefore, the fixing is performed when the room temperature is low or immediately after startup. Even when the temperature of the apparatus 40 is not sufficiently increased, the temperature of the fixing roller 41 can be raised to the temperature during the fixing operation in a short time. Further, after the temperature of the fixing roller 41 is sufficiently increased and the image forming operation is started, the amount of heat absorbed from the surroundings by the heat absorbing member 72 becomes large, and the fixing roller 41 is sufficiently absorbed by the heat radiation from the heat radiating unit 66 of the heat pump 60. Since it can heat, the electric power supplied to the heater lamps 84 and 85 of the external heating apparatus 80 can be reduced and power consumption can be suppressed.

  In the present embodiment, the position of the heat storage member 73 is switched to either the first position or the second position. However, the present invention is not limited to this, and is continuously or stepwise between the first position and the second position. It is good also as a structure which can be moved automatically. In this case, the heat storage member movement control unit 95 may set the position of the heat storage member 73 according to the temperature of the heat storage member 73 and the ambient temperature around the heat absorption member 72.

  In the present embodiment, the heat storage member movement control unit 95 controls the position of the heat storage member 73 based on the temperature detection results of the temperature sensors 74 and 77, but is not limited to this, for example, the operation of the heat pump 60. The heat storage member 73 may be moved when a predetermined time has elapsed since the start of the operation. In this case, since the temperature detection of the heat storage member 73 becomes unnecessary, the apparatus configuration can be simplified and the manufacturing cost of the image forming apparatus 100 can be reduced.

  In the present embodiment, the support rollers 81 and 82 and the external heating belt 83 in the external heating device 80 are configured to be movable between the first position and the second position. However, the present invention is not limited to this, and the support roller 81 is not limited thereto. -It is good also as a structure which 82 and the external heating belt 83 are always in a 1st position. In this case, the belt movement control unit 91 and the belt moving device 101 may be omitted.

[Embodiment 2]
Another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In Embodiment 1, the relative position of the heat storage member 73 and the heat absorption member 72 was changed by moving the heat storage member 73 in parallel. On the other hand, in this embodiment, the relative position with respect to the heat absorption member 72 of each part in the heat storage member 73 is changed by rotating the heat storage member 73. In other words, in this embodiment, by rotating the heat storage member 73, the contact area between the heat storage member 73 and the heat absorption member 72 does not change, but the contact position of the heat storage member 73 with respect to the heat absorption member 72 changes. ing.

  FIG. 9A is a plan view of the heat absorbing portion 65. FIG. 9B and FIG. 9C are cross-sectional views of the heat absorbing portion 65 in a cross section perpendicular to the extending direction of the heat medium pipe 71, and show states before and after the heat storage member 73 is rotated.

  As shown in FIG. 9A, the heat storage member 73 includes a shaft portion 73a and a number of disk-shaped fin portions 73b attached around the shaft portion 73a. Further, the fins constituting the fin portion 73b are inserted between the fins constituting the heat absorbing member 72, and the fins constituting the fin portion 73b and the fins constituting the heat absorbing member 72 are in contact with each other. It is like that.

  The shaft portion 73a is connected to a heat storage member moving device 67 serving as a rotation driving unit including a motor, a gear, and the like (not shown). And the thermal storage member movement control part 95 controls the operation | movement of the thermal storage member moving apparatus 67, The thermal storage member 73 is rotated centering | focusing on the axial part 73a. Thereby, the position which contacts with respect to the heat absorption member 72 in each fin of the thermal storage member 73 changes.

  The material of the heat storage member 73 is not particularly limited, and the same material as in the first embodiment can be used.

  The temperature sensor 78 is disposed in a contact region between the heat storage member 73 and the heat absorption member 72, measures the temperature of the heat storage member 73 in contact with the heat absorption member 72, and transmits the measurement result to the control device 90. . In the present embodiment, the temperature sensor 78 is provided so as to come into contact with the back surface of the fin of the heat storage member 73 that contacts the fin of the heat absorbing member 72. The configuration of the temperature sensor 78 is not particularly limited as long as the temperature of the heat storage member 73 can be appropriately measured. For example, a thermistor, a thermocouple, or the like can be used.

  Next, the operation at the time of image formation in the fixing device 40 according to the present embodiment will be described. FIG. 10 is a flowchart showing an operation flow of the fixing device 40.

  When an image formation instruction is input from a user via an operation panel (not shown) or the like, the rotation control unit 93 drives the rotation driving device 103 to start the rotation of the fixing roller 41 (S21). Further, the temperature control unit 92 controls the heating power supply unit 102 to supply power to the heater lamp 45 of the pressure roller 42 to start heating the pressure roller 42 (S22). Further, the heat pump drive control unit 94 controls each part of the heat pump 60 to drive the heat pump 60 (S23). Thereby, heating of the fixing roller 41 is started. At this time, the position of the external heating belt 83 is set to the second position. Further, the temperature controller 92 maintains the surface temperature of the pressure roller 42 at a predetermined temperature based on the temperature detection result of the thermistor 44 until the image forming operation is finished after the heating of the pressure roller 42 is started. In addition, the power supplied to the heater lamp 45 is controlled.

  Thereafter, the heat storage member movement control unit 95 is set to a first set temperature T1 (here, T1 = 4 ° C.) in which the temperature of the heat storage member 73 is preset based on the temperature detection result of the temperature sensor 78 provided in the heat absorption unit 65. It is determined whether it is less than () (S24).

  And when it judges that the temperature of the heat storage member 73 is less than 1st preset temperature T1 in S24, the heat storage member movement control part 95 controls the heat storage member moving apparatus 67, and before rotation in the heat storage member 73, it is for heat storage members. The heat storage member 73 is rotated so that the region C facing the fan 76 contacts the heat absorbing member 72 after the rotation (S25). In the present embodiment, since the heat medium pipe 71 and the shaft portion 73a of the heat storage member 73 are arranged in parallel to each other and have the same distance from the conveyance path of the recording paper P, the shaft portion 73a is replaced in S25. It is designed to rotate 1/4.

  When it is determined in S24 that the temperature of the heat storage member 73 is not lower than the first set temperature T1, and after the heat storage member 73 is rotated in S25, the temperature controller 92 determines the fixing roller based on the temperature detection result of the thermistor 43. It is determined whether or not the surface temperature of 41 has reached a predetermined temperature range set as a temperature at the time of image formation (S26).

  If it is determined that the temperature of the fixing roller 41 has not reached the predetermined temperature range, the belt movement control unit 91 controls the belt moving device 101 to move the external heating belt 83 to the first position (S27). The control unit 92 controls the heating power supply unit 102 to supply power for heating the fixing roller 41 to a predetermined temperature range to the heater lamps 84 and 85 (S28). As a result, the surface of the fixing roller 41 is heated via the external heating belt 83. Thereafter, the processing after S24 is continued while the heating of the fixing roller 41 is continued.

  On the other hand, if it is determined in S26 that the temperature of the fixing roller 41 has reached the predetermined temperature range, the temperature control unit 92 informs the main control unit of the image forming apparatus 100 that the temperature of the fixing roller 41 is within the predetermined temperature range. To be notified. Accordingly, the main control unit of the image forming apparatus 100 controls the operation of each unit, and the image forming operation on the recording paper P is executed (S29). As a result, the recording paper P to which the unfixed toner has been transferred is conveyed to the fixing nip N.

  Thereafter, the main control unit or the control device 90 determines whether or not to continue the image forming operation, that is, whether or not to perform the image forming operation on another recording sheet (S30). This determination may be made, for example, by determining whether image formation has been performed on the number of recording sheets instructed by the user. When the image forming operation is continued, the processes of S27 and S28 are performed, and the processes after S24 are performed again.

  On the other hand, when it is determined in S30 that the image forming operation is finished, the heat pump drive control unit 94 stops driving the heat pump 60 (S31). Further, the temperature control unit 92 controls the heating power supply unit 102 to stop energization of the heater lamps 45, 84, and 85 (S32). As a result, the operation of the fixing device 40 ends.

  As described above, in the image forming apparatus 100 according to the present embodiment, the heat released from the recording paper P after the fixing process is absorbed by the heat absorbing unit 65 and is heated to the high temperature by the heat pump 60 and used to heat the fixing roller 41. Accordingly, as in the first embodiment, the energy for heating the fixing roller 41 can be reduced as compared with the case where the fixing roller 41 is heated only by the heating unit that is heated by being supplied with electric power. Further, exhaust heat from the image forming apparatus 100 can be reduced. Further, it is possible to prevent the temperature of each member (each unit, electrical component, etc.) in the image forming apparatus 100 from being raised, and it is possible to prevent the operation of each member from becoming unstable due to the temperature rise. An image can be formed stably.

  Further, since the heat storage member 73 is in contact with the heat absorption member 72, the heat amount of the heat storage member 73 and the heat amount of the heat absorption member 72 are supplied to the evaporator 64 of the heat pump 60 (the heat of the heat absorption portion 65). The heat absorption member 72 and the heat storage member 73 are cooled by the low-temperature heat medium passing through the medium pipe 71). For example, when the amount of heat input from the outside to the heat absorption member 72 before the image forming operation is small. However, it is possible to prevent the heat absorption member 72 from being overcooled by the evaporator 64 of the heat pump 60 and causing freezing or condensation.

  Moreover, in this embodiment, when the temperature of the heat storage member 73 falls below the first set temperature T1, the heat storage member movement control unit 95 controls the heat storage member moving device 67, and the heat storage member 73 is rotated before the heat storage member 73 is rotated. The heat storage member 73 is rotated such that the region C facing the fan 76 contacts the heat absorbing member 72 after the rotation.

  The portion of the heat storage member 73 that is in contact with the heat absorbing member 72 is cooled together with the heat absorbing member 72 by the low-temperature heat medium flowing through the heat medium pipe 71, and the temperature decreases. On the other hand, the portion of the heat storage member 73 that faces the heat storage member fan 76 is supplied with air heated to high temperature by heat dissipation from the recording paper P by the heat storage member fan 76, and the temperature rises due to heat exchange with this air. To do. For this reason, when the temperature of the heat storage member 73 falls below the first set temperature T <b> 1, the heat storage member movement control unit 95 controls the heat storage member moving device 67, and before the heat storage member 73 rotates, By rotating the heat storage member 73 so that the region C that has been opposed contacts the heat absorption member 72 after rotation, the high temperature portion of the heat storage member 73 can be brought into contact with the heat absorption member 72, and the heat absorption amount of the heat absorption member 72 can be reduced. Can be increased.

  In the present embodiment, the first set temperature T1 is set to 4 ° C., but is not limited to this. However, the first set temperature T1 is higher than 0 ° C. in order to appropriately prevent the heat absorption member 72 from freezing and dew condensation, and is higher than the in-machine temperature of the image forming apparatus 100 or the temperature around the image forming apparatus 100 (room temperature). Preferably it is low. By making 1st preset temperature T1 higher than 0 degreeC, it can prevent that the water | moisture content in air freezes on the surface of the thermal storage member 73. FIG. Thereby, it can prevent that ice adheres to the surface of the heat absorption member 72 and the heat storage member 73, and inhibits heat exchange with air. Moreover, it can prevent that the heat storage member 73 and the heat absorption member 72 adhere | attach with ice, and the movement of the heat storage member 73 is inhibited. Further, by making the first set temperature T1 lower than the in-machine temperature, heat can be absorbed from the air in the machine by the heat storage member 73 in a portion separated from the heat absorbing member 72. Thereby, when the said part is made to contact the heat absorbing member 72 after that, the amount of heat supplied to the heat absorbing member 72 can be increased. The in-machine temperature of the image forming apparatus 100 may be detected by a temperature sensor 134 provided at a position distant from the fixing device 40 as shown in FIG.

[Embodiment 3]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those of the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 11 is a schematic diagram illustrating a schematic configuration of the fixing device 40b according to the present embodiment. In the first and second embodiments, a roller pair type fixing device that fixes a toner image on the recording paper P by supplying the recording paper P to a fixing nip N formed between the fixing roller 41 and the pressure roller 42. 40 was used. In contrast, in the present embodiment, as shown in FIG. 11, a fixing belt device including an endless belt 143 stretched around support rollers 141 and 142 instead of the fixing roller 41 in the first and second embodiments. A fixing device 40b including 140 is used. The configuration of the fixing device 40b is substantially the same as that of the fixing device 40 in the first and second embodiments, except that the fixing roller 41 is changed to the fixing belt device 140 and the belt moving device 101 and the belt movement control unit 91 are omitted. is there.

  The fixing belt device 140 includes a first support roller 141, a second support roller 142, and an endless belt 143.

  The first support roller 141 and the second support roller 142 are made of a thin stainless steel pipe having a thickness of 0.3 mm. Further, the first support roller 141 is provided on the downstream side in the rotation direction of the endless belt 143 with respect to the fixing nip N formed by the endless belt 143 and the pressure roller 42, and the second support roller 142 is provided with respect to the fixing nip N. Is also provided upstream of the endless belt 143 in the rotational direction.

  In addition, a pipe (heat medium pipe) constituting the heat radiating unit 66 of the heat pump 60 is disposed inside the first support roller 141. A heater lamp (second heat source) 146 is arranged inside the second support roller 142. The heater lamp 146 generates heat when supplied with power from the heating power supply unit 102 and heats the second support roller 142. In this embodiment, a halogen lamp is used as the heater lamp 146. However, the present invention is not limited to this, and any heater that can heat the second support roller 142 by being supplied with electric power may be used.

  The endless belt 143 is obtained by laminating a polyimide base material having a thickness of 90 μm and a fluororesin layer made of PTFE or PFA in this order on a polyimide base material having a thickness of 90 μm, and is attached to the first support roller 141 and the second support roller 142. It is stretched. The configuration of the endless belt 143 is not limited to this. For example, a thin metal such as stainless steel or nickel may be used as a base material of the endless belt 143.

  The pressure roller 42 is urged toward the fixing belt device 140 by an elastic member (spring) (not shown). As a result, the endless belt 143 and the pressure roller 42 are in pressure contact with each other with a predetermined load to form the fixing nip N.

  Further, the first support roller 141 is connected to the rotation drive device 103, and is driven to rotate by the rotation control unit 93 controlling the operation of the rotation drive device 103. When the first support roller 141 rotates, the endless belt 143 is driven to rotate by the first support roller 141, and the second support roller 142 and the pressure roller 42 are driven to rotate by the endless belt 143. Note that the configuration of the rotary drive device 103 is not particularly limited, but is configured by, for example, a motor, a gear, or the like. In the present embodiment, the first support roller 141 is rotationally driven by the rotation driving device 103. However, the present invention is not limited to this, and the first support roller 141, the second support roller 142, and the pressure roller 42 are not limited thereto. Any configuration may be used as long as any one of these rollers is rotated to rotate each of these rollers.

  Further, a thermistor 144 is provided on the outer peripheral surface of the endless belt 143 in the contact region with the first support roller 141, and the thermistor 145 is provided on the outer peripheral surface of the contact region with the second support roller 142. The temperature detection result on the surface of the endless belt 143 by the thermistors 144 and 145 is transmitted to the temperature control unit 92.

  Based on the temperature detection result of the thermistor 145, the temperature controller 92 determines that the surface temperature (detected temperature of the thermistor 145) in the contact area of the endless belt 143 with the second support roller 142 during the image forming operation is a predetermined temperature (here, In this case, the power supplied from the heating power supply unit 102 to the heater lamp 146 is controlled to be 190 ° C.

  Further, when the image forming operation is stopped (waiting for the next image forming instruction; standby mode), the temperature control unit 92 performs the second support of the endless belt 143 based on the temperature detection result of the thermistor 145. The power supplied from the heating power supply unit 102 to the heater lamp 146 is controlled so that the surface temperature (detection temperature of the thermistor 145) in the contact area with the roller 142 becomes a predetermined temperature (here, 160 ° C.). As a result, the temperature of the second support roller 142 can be kept at a predetermined temperature, so that the temperature of the second support roller 142 is increased to a predetermined temperature (190 ° C. in this case) for image formation during the next image forming operation. Can be quickly heated.

  Further, the heat pump drive controller 94 determines the surface temperature (thermistor 144) in the contact area of the endless belt 143 with the first support roller 141 during the image forming operation based on the temperature detection result of the thermistors 144 and 145 during the image forming operation. Of the heat pump 60 is controlled so that the detected temperature becomes a predetermined temperature (here, 185 ° C.).

  Note that the configuration of the heat absorption unit 65 and the movement control method of the heat storage member 73 are the same as those in the first or second embodiment, and thus description thereof is omitted here.

  As described above, in this embodiment, the heat pump 60 having the same configuration as that of the first or second embodiment is provided, and the first support roller 141 and the endless belt 143 in the fixing belt device 140 are connected by the heat radiating unit 66 of the heat pump 60. Heat. Thereby, the substantially same effect as Embodiment 1, 2 can be acquired.

  Further, in the present embodiment, as a heating means for heating the endless belt 143, a heat radiating portion (first heat source) 66 of the heat pump 60 and a heater lamp (second heat source) 146 are provided. Thereby, the endless belt 143 can be efficiently heated by these two heat sources.

  In the present embodiment, the first support roller 141 heated by the heat radiating unit 66 is provided downstream of the fixing nip N in the rotation direction of the endless belt 143, and the second support roller heated by the heater lamp 146. 142 is provided upstream of the fixing nip N in the rotational direction of the endless belt 143. Further, the heat pump drive control unit 94 controls the operation of the heat pump 60 so that the temperature of the endless belt 143 in the contact area with the first support roller 141 becomes a predetermined temperature (here, 185 ° C.), and the temperature control unit 92 2 The power supplied from the heating power supply unit 102 to the heater lamp 146 is controlled so that the temperature of the endless belt 143 in the contact area with the support roller 142 becomes a predetermined temperature (190 ° C. in this case).

  As a result, the endless belt 143 deprived of heat by the recording paper P (the temperature of the endless belt 143 decreases to about 160 ° C. due to the deprivation of heat by the recording paper P) is fixed by the heat from the heat radiating unit 66. The endless belt 143 can be heated to a predetermined temperature for fixing operation (here, 190 ° C.) by heat from the heater lamp 146 by heating to a predetermined temperature (here, 185 ° C.) that is slightly lower than the temperature for the fixing. . Therefore, compared with the case where the heat pump 60 is not provided, the electric power for heating the endless belt 143 can be reduced.

  Moreover, although it is possible to control the temperature of the heat radiating part 66 by controlling the operation of each part of the heat pump 60, the control response speed for the temperature of the heat radiating part in the heat pump is a halogen lamp that converts electric power into heat, etc. Slow compared to the heating means. For this reason, the temperature of the endless belt 143 is quickly and accurately adjusted by heating the endless belt 143 by the heat radiating unit 66 of the heat pump 60 and then heating the endless belt 143 by the heat from the heater lamp 146. Can be controlled.

  In the present embodiment, the configuration in which the endless belt 143 is stretched between the first support roller 141 and the second support roller 142 has been described. However, the configuration is not limited to this, and tension is applied to the endless belt 143. A backup roller (not shown) may be further provided. Further, the backup roller may be a hard stainless steel pipe, like the first support roller 141 and the second support roller 142, or may be a sponge roller having an elastic layer such as a sponge formed on the surface. . The backup roller may be a sponge roller, and the backup roller and the pressure roller 42 may be in pressure contact with each other via the endless belt 143. In this case, the endless belt 143 contacts the pressure roller 42 only in the pressure contact region between the backup roller and the pressure roller 42, and the contact region between the endless belt 143 and the first support roller 141 and the endless belt 143 and the second support roller. The endless belt 143 may not be in contact with the pressure roller 42 in the contact area with the contact 142.

  Moreover, in each said embodiment, you may apply | coat heat conductive grease to the contact part of a thermal storage member and a thermal absorption member. The thermal conductive grease is not particularly limited as long as it has thermal conductivity and lubricity. For example, a high thermal conductive filler such as graphite or metal powder, silicon oil having lubricity, etc. Thermally conductive grease dispersed in a lubricant can be used. By applying thermally conductive grease to the contact portion between the heat storage member and the heat absorption member, heat transfer between the heat storage member and the heat absorption member is improved and the relative position or contact position between the heat storage member and the heat absorption member is changed. The frictional force generated between these two members can be reduced, and the occurrence of wear and noise can be prevented.

  In each of the above embodiments, the cross-sectional shape of the cross section perpendicular to the paper conveyance direction of the heat absorbing member is circular, but the present invention is not limited to this. For example, it may be a substantially square shape used in an air conditioner or the like, and may be an ellipse or a polygon.

  Further, in each of the above-described embodiments, the configuration in which the heat absorption unit 65 is provided on the downstream side in the recording paper conveyance direction with respect to the fixing device 40 has been described, but the installation position of the heat absorption unit 65 is not limited to this. For example, it may be provided above the fixing device 40 in the vertical direction. In this case, the heat dissipated from the fixing device 40 can be absorbed by the heat absorbing unit 65 by the convection of air heated by the heat from the fixing device 40.

  Moreover, in each said embodiment, although the surface area of the thermal storage member 73 and the surface area of the heat absorption member 72 are substantially equivalent, it does not restrict to this. For example, the surface area of the heat storage member 73 may be larger than the surface area of the heat absorption member 72. In this case, since the heat transfer area and heat capacity of the heat storage member 73 can be made larger than when the surface area of the heat storage member 73 is substantially equal to that of the heat absorption member 72, a larger amount of heat can be stored.

  In each of the above embodiments, the case where the single-stage compression type compressor 61 is used has been described. However, the present invention is not limited to this, and a multi-stage compression type compressor 61 may be used. For example, a two-stage compression method in which a low-pressure compressor, an intermediate cooler, and a high-pressure compressor are provided may be used. Instead of the intermediate cooler, a two-stage compression and two-stage expansion system having a cascade condenser that doubles as an evaporator of a low-pressure compressor and a condenser of a high-pressure compressor and an expansion valve may be used.

  In each of the above embodiments, a case where a vapor compression refrigeration cycle is used as the heat pump 60 has been described. However, the heat pump 60 is not limited thereto, and examples thereof include an absorption refrigeration cycle, an adsorption refrigeration cycle, an air expansion refrigeration cycle, and a thermoelectric refrigeration cycle. It may be used.

  In each of the above-described embodiments, the configuration in which heat is supplied to the fixing roller 41 by the heat pump 60 has been described. However, the configuration is not limited thereto, and for example, heat may be supplied to the pressure roller 42 by the heat pump 60. The heat pump 60 may supply heat to both the fixing roller 41 and the pressure roller 42. In the configuration in which heat is supplied from the heat pump 60 to both the fixing roller 41 and the pressure roller 42, the temperatures of the outer peripheral surfaces of both the fixing roller 41 and the pressure roller 42 are accurately maintained during continuous paper feeding and standby. In addition, the heating power can be reduced as compared with the case where both the rollers are heated only by the heater lamp. As a result, energy saving and high-quality images can be stably obtained, and at the same time, high throughput can be obtained continuously.

  In each of the above embodiments, the toner image is transferred from the image carrier to the recording paper conveyed by the conveyance belt. However, the present invention is not limited to this. For example, the recording paper is transferred from the image carrier via the intermediate transfer belt. Alternatively, the toner image may be transferred to the printer. Further, the present invention is not limited to a configuration in which a plurality of color toner images are transferred for recording, and a configuration in which a single color toner image is transferred to a recording sheet may be used.

  Further, in each of the above embodiments, the toner image is electrostatically transferred onto the recording paper, and then the toner image on the recording paper is pressed and heated by the fixing device to be fixed on the recording paper. A transfer fixing configuration in which the toner image is pressurized and heated and fixed onto the recording paper simultaneously with the transfer onto the paper may be employed.

  In each of the above-described embodiments, the case where the present invention is applied to a color image forming apparatus having the fixing roller 41 provided with the elastic layer 41b is described. However, the present invention is not limited to this, and a single-color image using only a single-color toner is used. You may apply to a formation apparatus. In this case, for example, a configuration may be used in which the fixing roller 41 is not provided with the elastic layer 41b but a hard roller in which the release layer 41c is formed on the cored bar 41a.

  In each of the above embodiments, the fixing device configured to fix the toner image on the recording paper to the recording paper by heat and pressure by the fixing roller or the fixing belt device and the pressure roller has been described. However, the present invention is not limited to this, and any apparatus may be used as long as the toner image is fixed on the recording paper using heat. The present invention may be applied to, for example, an oven fixing type fixing device.

  In each of the above-described embodiments, the configuration in which the heat from the heat radiating unit 66 is supplied to the member (the fixing roller or the fixing belt device) for heating the recording paper in the fixing nip N has been described. It is not limited to. For example, as shown in FIG. 12, the fixing device 40 is provided with a preheating member 26 that preheats recording paper (or recording paper and an unfixed toner image) upstream of the fixing nip portion in the recording paper conveyance direction. The preheating member 26 may be configured to preheat the recording paper (or the recording paper and the unfixed toner image) with heat radiated from the heat radiating unit 66. The preheating member 26 may perform preheating in a non-contact state with respect to the recording paper, and may be in contact with the recording paper (for example, the back surface of the recording paper (an unfixed toner image is formed). Preheating may be performed in a state in which the surface abuts on the surface opposite to the surface).

  By performing preheating of the recording paper, the temperature of the recording paper (or the recording paper and the unfixed toner image) before being conveyed to the fixing nip portion N can be raised, thereby improving the fixability, and The energy consumption of the fixing device 40 can be reduced. In a fixing device other than the heat roller pair method and the oven fixing method (for example, flash fixing method), the preheating member 26 preheats the recording paper (or the recording paper and the unfixed toner image) before the fixing process. You may make it do.

  In each of the above embodiments, the control device 90 is configured from the control integrated circuit board. However, the present invention is not limited to this, and the function of each control unit provided in the control device 90 using a processor such as a CPU. May be realized by software. In this case, for example, the control device 90 includes a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and a RAM (random access) that expands the program. memory), a storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is to provide a recording medium in which a program code (execution format program, intermediate code program, source program) of a control program of the control device 90, which is software that realizes the functions described above, is recorded in a computer-readable manner, The program is supplied to the control device 90, and the computer (or CPU or MPU) reads and executes the program code recorded on the recording medium.

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  The control device may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. This communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, A satellite communication network or the like can be used. Further, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE1394, USB, power line carrier, cable TV line, telephone line, ADSL line, infrared rays such as IrDA and remote control, It is also possible to use wireless such as Bluetooth (registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network. The present invention can also be realized in the form of a computer data signal (data signal sequence) embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be applied to an image forming apparatus including a heat-fixing type fixing device.

1 is a schematic diagram illustrating a schematic configuration of a fixing device provided in an image forming apparatus according to an embodiment of the present disclosure. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a configuration of a belt moving device provided in the fixing device illustrated in FIG. 1. (A) is a top view of the belt moving device shown in FIG. 3, and (b) is a side view thereof. FIG. 2 is a block diagram illustrating a configuration of a heat pump provided in the fixing device illustrated in FIG. 1. It is a TS diagram of the heat pump shown in FIG. (A) And (c) is a top view of the heat absorption part with which the heat pump shown in FIG. 1 is equipped, (b) And (d) is the side view. FIG. 2 is a flowchart showing a flow of an image forming operation in the fixing device shown in FIG. 1. FIG. 6 is a diagram illustrating a configuration of a heat absorption unit of a heat pump provided in a fixing device of an image forming apparatus according to another embodiment of the present invention, where (a) is a plan view of the heat absorption unit, and (b) and (c) are the above. It is sectional drawing of a heat absorption part. FIG. 6 is a flowchart showing a flow of an image forming operation in a fixing device of an image forming apparatus according to another embodiment of the present invention. FIG. 6 is a schematic diagram illustrating a schematic configuration of a fixing device provided in an image forming apparatus according to still another embodiment of the present invention. It is a schematic diagram which shows the modification of the image forming apparatus concerning one Embodiment of this invention.

Explanation of symbols

26 Preheating member 40, 40b Fixing device 41 Fixing roller (heating member)
42 Pressure roller 43, 44, 86, 87, 144, 145 Thermistor 45, 84, 85, 146 Heater lamp 60 Heat pump 65 Heat absorption part 66 Heat radiation part 67 Heat storage member moving device (drive means)
71 Heat medium pipe 72 Heat absorption member 73 Heat storage member 73a Shaft portion 73b Fin portions 74, 77, 78, 134 Temperature sensor 75 Fan for heat absorption member (first blower)
76 Heat storage member fan (second blower)
80 External heating device 81, 82 Support roller 83 External heating belt 90 Control device (control means)
91 belt movement control unit 92 temperature control unit 93 rotation control unit 94 heat pump drive control unit 95 heat storage member movement control unit (control means)
DESCRIPTION OF SYMBOLS 100 Image forming apparatus 102 Heating power supply part 140 Fixing belt apparatus 141,142 Support roller 143 Endless belt

Claims (19)

A fixing device that heats and fixes the unfixed toner image formed on the recording material to the recording material, and a heat pump that dissipates heat by moving the heat absorbed by the heat absorbing portion to a heat radiating portion having a higher temperature than the heat absorbing portion; An image forming apparatus that heats an unfixed toner image using heat that the fixing device dissipates from the heat radiating portion,
An endothermic member provided in the endothermic part to absorb external heat;
A heat storage member provided in contact with the heat absorbing member;
Drive means for changing a relative position between the heat absorbing member and the heat storage member or a contact position of the heat storage member with the heat absorption member;
Control means for controlling the operation of the drive means to control the relative position between the heat absorption member and the heat storage member or the contact position of the heat storage member with the heat absorption member;
The image forming apparatus, wherein the control unit controls the operation of the driving unit so that the heat storage member and the heat absorption member are in contact with each other when heating of the fixing device is started. A temperature sensor that detects the temperature of the heat storage member in contact with the heat absorbing member;
When the temperature detected by the temperature sensor is lower than a preset first set temperature, the control means sets the relative position between the heat storage member and the heat absorption member so that the heat storage member and the heat absorption member are separated from each other. The operation of the driving means is controlled so that the second position is a position where the contact area between the heat storage member and the heat absorption member is smaller than the contact area at the start of heating. Item 2. The image forming apparatus according to Item 1. The control means includes
In a state where the relative position between the heat storage member and the heat absorption member is the second position, when the temperature detected by the temperature sensor is higher than a preset second set temperature, the heat storage member and the above The relative position to the heat absorbing member is set to the first position where the contact area between the heat storage seat and the heat absorption member is larger than the contact area between the heat storage seat and the heat absorption member at the second position. The image forming apparatus according to claim 2, wherein the operation of the driving unit is controlled. A temperature sensor that detects the temperature of the heat storage member in contact with the heat absorbing member;
When the temperature detected by the temperature sensor is lower than a first preset temperature, the control means is configured to bring a position of the heat storage member that is not in contact with the heat absorption member into contact with the heat absorption member. The image forming apparatus according to claim 1, wherein the operation of the driving unit is controlled.   5. The image forming apparatus according to claim 2, wherein the first preset temperature is higher than 0 ° C. and lower than room temperature.   When the predetermined time has elapsed after starting the heating in the fixing device, the control means sets the relative position between the heat storage member and the heat absorption member as the position where the heat storage member and the heat absorption member are separated from each other, or 2. The operation of the driving means is controlled such that the contact area between the heat storage member and the heat absorption member is a second position which is a position smaller than the contact area at the start of heating. Image forming apparatus.   When the predetermined time has elapsed after starting the heating in the fixing device, the control means sets the position of the heat storage member that has not been in contact with the heat absorption member before the predetermined time has passed to the heat absorption member. The image forming apparatus according to claim 1, wherein the operation of the driving unit is controlled so as to make contact. A second temperature sensor for detecting the temperature around the heat absorbing member;
When the temperature detected by the second temperature sensor is equal to or higher than a preset third set temperature, the control means determines the relative position of the heat storage member to the heat absorption member, the heat storage member, the heat absorption member, The operation of the driving means is controlled such that the contact position between the heat storage member and the heat absorption member is a second position which is a position where the contact area between the heat storage member and the heat absorption member is smaller than the contact area at the start of heating. The image forming apparatus according to claim 1. A conveying means for conveying the recording material,
9. The heat absorption member according to claim 1, wherein the heat absorption member is disposed to face the recording material conveyance path on the downstream side of the fixing device in the conveyance direction of the recording material. The image forming apparatus described.   The image forming apparatus according to claim 9, further comprising a first blower that generates an airflow in a direction from a conveyance path side on which the recording material after the fixing process is conveyed toward the heat absorbing member side.   11. The image forming apparatus according to claim 9, wherein the heat storage member is disposed so as to oppose the recording material conveyance path on the downstream side of the heat absorption member in the recording material conveyance direction.   The image forming apparatus according to claim 11, further comprising a second blower that generates an air flow in a direction from a conveyance path side on which the recording material after the fixing process is conveyed toward the heat storage member side. The fixing device includes a heating member for heating the unfixed toner image,
The heating member is heated by heat radiated from the heat radiating portion and heat supplied from an electric heating means for converting electricity into heat. The image forming apparatus described. The heating member is a hollow roller member,
The heat dissipating part is disposed in a hollow portion of the roller member;
The image forming apparatus according to claim 13, wherein the electric heating unit is provided so as to contact an outer peripheral surface of the roller member. The heating member is a belt member stretched around a plurality of support rollers including a first support roller and a second support roller,
The first support roller and the second support roller have a hollow shape,
The heat dissipating part is provided in a hollow portion of the first support roller;
The image forming apparatus according to claim 13, wherein the electric heating means is provided in a hollow portion of the second support roller. The belt member is adapted to rotate along the stretching direction,
The first support roller is formed on the belt member on the downstream side in the rotation direction with respect to the contact portion with the pressure roller and on the upstream side in the rotation direction with respect to the contact portion with the second support roller. The image forming apparatus according to claim 15, wherein the image forming apparatus is disposed so as to abut against the image forming apparatus. A fixing device that heats and fixes the unfixed toner image formed on the recording material to the recording material, and a heat pump that dissipates heat by moving the heat absorbed by the heat absorbing portion to a heat radiating portion having a higher temperature than the heat absorbing portion; A method of controlling an image forming apparatus that heats an unfixed toner image using heat that the fixing device dissipates from the heat radiating portion,
The image forming apparatus includes: a heat absorption member provided in the heat absorption unit to absorb external heat; a heat storage member provided in contact with the heat absorption member; and a relative position between the heat absorption member and the heat storage member. Or a drive means for changing the contact position of the heat storage member with the heat absorbing member,
A method for controlling an image forming apparatus, comprising: controlling an operation of the driving unit so that the heat storage member and the heat absorbing portion are in contact with each other when heating of the fixing device is started.   A program for operating the image processing apparatus according to any one of claims 1 to 16, wherein the program causes a computer to function as the control means.   The computer-readable recording medium which recorded the program of Claim 18.

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