JP2013015661A - Fixing device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device and an image forming apparatus capable of reducing energy consumption.SOLUTION: A fixing device 100 comprises: a heating roll 104 which releases radiation heat H; a pressure belt 106; and an enclosure 102 which rotatably houses the heating roll 104 and the pressure belt 106. It is provided with, inside the enclosure 102, a sheet member 144 which has a higher reflectance ratio than the enclosure 102 and reflects the radiation heat H towards the heating roll 104. The radiation heat H released from the heating roll 104 is reflected by the sheet member 144 inside a housing 102A and is transferred to the heating roll 104. This improves the energy utilization efficiency by the heating roll 104 and reduces the energy consumption by the fixing device 100.

Description

  The present invention relates to a fixing device and an image forming apparatus.

  The image forming apparatus disclosed in Patent Document 1 is provided with an air exhaust device including a duct, a fan, and a guide cover below a portion adjacent to an upper cover attached to the upper side of the fixing device, and an upper portion of radiant heat from the fixing device. Reduces conduction to the cover.

  In the image forming apparatus disclosed in Patent Document 2, a fixing device and a cleaning device are arranged to face each other, and a reflective film is provided on a partition wall surface outside the fixing device.

JP 2000-221867 A JP-A-2005-195907

  An object of the present invention is to obtain a fixing device and an image forming apparatus capable of reducing energy consumption.

  A fixing device according to a first aspect of the present invention includes a heating rotator that emits radiant heat, a pressure rotator that pressurizes a recording medium with the heating rotator, the heating rotator, and the pressure rotator. And a reflective surface that has a higher reflectance than the housing and reflects radiant heat toward the heating rotator, and is provided inside the housing.

  In the fixing device according to a second aspect of the present invention, the reflection surface is disposed at a portion facing the outer peripheral surface of the heating rotator.

  In the fixing device according to a third aspect of the present invention, a heat source for heating the heating rotator is provided inside the heating rotator, an axial end of the heating rotator is opened, and the reflection surface is The heating rotary member is disposed at a portion facing the axial end portion.

  In the fixing device according to a fourth aspect of the present invention, the casing is made of resin.

  An image forming apparatus according to a fifth aspect of the present invention includes a latent image holding member that holds a latent image, a developing unit that develops the latent image with a developer to form a developer image, and the developer image as a recording medium. And transferring the developer image on the recording medium that has been transferred and transported into the housing between the heating rotator and the pressurizing rotator to fix the image on the recording medium. And a fixing device according to any one of claims 1 to 4.

  According to the first aspect of the present invention, energy consumption can be reduced as compared with a configuration in which a reflecting surface for reflecting radiant heat is not provided inside the housing.

  According to the second aspect of the present invention, the radiant heat from the heating rotator can be effectively used as compared with the configuration in which the reflecting surface is not disposed at the portion facing the outer peripheral surface of the heating rotator.

  The invention according to claim 3 can effectively use the radiant heat from the heating rotator as compared with the configuration in which the reflecting surface is not disposed at the portion facing the axial end of the heating rotator.

  According to the invention of claim 4, the amount of radiant heat absorbed by the housing can be suppressed as compared with the case where the housing is made of metal.

  According to the fifth aspect of the present invention, energy consumption can be reduced as compared with a configuration having a fixing device in which a reflecting surface for reflecting radiant heat is not provided inside the housing.

1 is a configuration diagram illustrating an internal structure of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a configuration diagram of a main part of a photoreceptor unit according to an embodiment of the present invention. 1A is a longitudinal sectional view of a fixing device according to an embodiment of the present invention. (B) It is sectional drawing which shows the structure of the housing | casing of the fixing device which concerns on embodiment of this invention. FIG. 3 is an explanatory view of the fixing device according to the embodiment of the present invention as viewed from the heating roll side. FIG. 4A is a schematic diagram illustrating a state in which radiant heat is reflected by a reflection surface inside the casing of the fixing device according to the embodiment of the present disclosure. (B) It is a schematic diagram which shows the state which reflects a radiant heat with the reflective surface arrange | positioned in the site | part facing the axial direction edge part of the heating rotary body which concerns on embodiment of this invention. FIG. 4A is a longitudinal sectional view of a fixing device according to another embodiment of the present invention. (B) It is sectional drawing which shows the structure of the housing | casing of the fixing device which concerns on the other Example of this invention.

  An example of a fixing device and an image forming apparatus according to an embodiment of the present invention will be described.

  FIG. 1 shows an image forming apparatus 10 as an example of the embodiment. The image forming apparatus 10 includes a casing 12 as an apparatus main body. The casing 12 forms a front cover 14 that forms the front surface of the image forming apparatus 10, a side cover 16 that forms a side surface, and an upper surface. And a top cover 18 to be configured. In the following description, the front cover 14 is viewed from the front, the direction from the rear surface to the front surface of the image forming apparatus 10 is the arrow X direction, the direction from the bottom surface to the upper surface (vertical direction) is the arrow Y direction, and from the left side surface. A direction toward the right side surface is described as an arrow Z direction.

  The front cover 14 is formed in an L shape across the front surface and the upper surface of the image forming apparatus 10 when viewed in the arrow Z direction. The front cover 14 is provided with a manual paper feed unit 22 that can be opened in the direction of arrow X. An operation panel (not shown) is provided above the manual paper feed unit 22 in the front cover 14. . This operation panel is connected to a control unit 20 that controls the operation of each unit of the image forming apparatus 10. On the other hand, the top cover 18 is provided with a paper discharge unit 26 for discharging the recording paper P after image formation.

  Inside the housing 12, photosensitive units 30Y, 30M, 30C, and 30K corresponding to yellow (Y), magenta (M), cyan (C), and black (K) toner colors are provided ( Hereinafter, the photoconductor units 30 are collectively referred to without distinction for each color).

  The photoconductor unit 30 has a box-shaped unit main body 34. A cylindrical image is formed in the unit main body 34, and a latent image formed as a developer image with toner (developer) is held on the outer peripheral surface. A photosensitive member 32 is provided as an example of the latent image holding member. The photoreceptor 32 includes a rotation shaft 32A (see FIG. 2) whose axial direction is the arrow Z direction, and the rotation shaft 32A is rotatably supported by a side plate (not shown) constituting a part of the unit main body 34. Has been.

  On the other hand, inside the case 12, developing units 36Y, 36M, 36C, and 36K as examples of developing units are provided adjacent to the respective photoreceptor units 30Y, 30M, 30C, and 30K (hereinafter referred to as color). When the generic name is used without distinction, it is referred to as a developing device 36).

  As shown in FIG. 2, each developer 36 is filled with toner and a carrier (developer) by being supplied with toner from a toner cartridge (not shown) loaded in the housing 12. The developer is circulated and conveyed by the rotation of the spiral conveying member 42 provided inside the developing device 36. Further, each developing device 36K is rotatably provided with a developing sleeve 38 provided therein with a magnetic member (not shown) composed of a plurality of magnetic poles. The developing sleeve 38 conveys the developer layer formed on the outer peripheral surface to a position facing the photoconductor 32 by rotation, and a toner corresponding to a latent image (electrostatic latent image) formed on the outer peripheral surface of the photoconductor 32. The toner image (developer image) is formed by developing the toner image.

  Further, the outer peripheral surface (surface) of the photoconductor 32 is charged at a position that is upstream of the developing sleeve 38 in the rotation direction (arrow R direction) of the photoconductor 32 and is in contact with the outer peripheral surface of the photoconductor 32. A charging roll 44 is rotatably provided. The charging roll 44 is energized from a power source (not shown), and charges the outer peripheral surface of the photoconductor 32 with the same polarity as the toner by a potential difference with the photoconductor 32 grounded on the inside. A cleaning roll 46 for cleaning the outer peripheral surface of the charging roll 44 is rotatably provided on the outer peripheral surface of the charging roll 44 opposite to the photoconductor 32.

  Further, a cleaning unit 47 for cleaning the outer peripheral surface of the photoconductor 32 after the toner image transfer is provided on the downstream side of a primary transfer roll 64 described later in the rotation direction of the photoconductor 32. The cleaning unit 47 includes a cleaning blade 49 whose tip is in contact with the outer peripheral surface of the photoconductor 32, and stores the toner scraped off by the cleaning blade 49. In addition, at the position downstream of the primary transfer roll 64 and upstream of the cleaning blade 49 in the rotation direction of the photoconductor 32, the charge is removed to such an extent that the outer peripheral surface of the photoconductor 32 after the primary transfer can be cleaned. A neutralizing lamp 59 is provided.

  On the other hand, as shown in FIG. 1, an exposure unit 48 is provided inside the housing 12 and below the photoconductor unit 30 and the developing unit 36. As an example, the exposure unit 48 includes optical components (all of which are not shown) such as a light source, a polygon mirror, and a reflection mirror formed of a semiconductor laser. In the exposure unit 48, each photoconductor charged with laser light LB (laser light LB-Y, LB-M, LB-C, LB-K) emitted from the light source by the charging roll 44 (see FIG. 2). By irradiating while scanning the surface of 32, an electrostatic latent image corresponding to image information is formed on the surface of the photoreceptor 32. The light source for forming the electrostatic latent image on the photosensitive member 32 is not limited to a semiconductor laser, and light emitting elements such as LEDs may be arranged to emit light based on image information.

  An intermediate transfer unit 50 is provided above the four photosensitive members 32 corresponding to the respective toner colors. The intermediate transfer unit 50 includes a driving roll 54, a driven roll 56, a tension applying roll 58, and a conveying roll 62, which will be described later, a housing (not shown) that rotatably supports these rolls, and an arrow A direction using these rolls. And an intermediate transfer belt 52 as an example of transfer means supported so as to be able to move around.

  The intermediate transfer belt 52 is endless, and is driven by a drive roll 54 driven by the control unit 20, a driven roll 56 driven to rotate, a tension applying roll 58 for applying tension to the intermediate transfer belt 52, It is wound around a plurality of conveyance rolls 62 that are in contact with the back surface of the transfer belt 52 and are driven to rotate. The intermediate transfer belt 52 rotates in the direction of arrow A (counterclockwise direction in the figure) as the drive roll 54 rotates. Further, the intermediate transfer belt 52 is disposed on the downstream side of each developing device 36 in the rotation direction of each photoconductor 32 and above each photoconductor 32, and is formed on the outer peripheral surface of each photoconductor 32. The toner images are transferred in a superimposed manner.

  A primary transfer roll 64 as an example of a transfer unit that primarily transfers the toner image formed on the outer peripheral surface of each photoconductor 32 to the intermediate transfer belt 52 on the opposite side of each photoconductor 32 across the intermediate transfer belt 52. Is provided. The primary transfer roll 64 is in contact with the back surface of the intermediate transfer belt 52, and is energized from a power source (not shown), whereby a toner image on the outer peripheral surface of the photoconductor 32 is caused by a potential difference from the grounded photoconductor 32. Is primarily transferred to the intermediate transfer belt 52. The intermediate transfer belt 52 contacts the outer peripheral surface of each photoconductor 32 in the order of the photoconductor units 30Y, 30M, 30C, and 30K, thereby transferring the toner images of Y, M, C, and K colors. Are superimposed.

  Further, on the opposite side of the drive roll 54 with the intermediate transfer belt 52 interposed therebetween, as an example of a transfer unit that secondarily transfers the toner image superimposed on the outer peripheral surface of the intermediate transfer belt 52 onto the conveyed recording paper P. The secondary transfer roll 66 is provided. The secondary transfer roll 66 is energized from a power source (not shown) so that the toner image on the outer peripheral surface of the intermediate transfer belt 52 is secondarily transferred to the recording paper P by a potential difference from the grounded drive roll 54. It has become.

  In addition, a cleaning unit 65 is provided to face one of the conveyance rolls 62 around which the intermediate transfer belt 52 is wound. The cleaning unit 65 includes a cleaning blade 67 that comes into contact with the outer peripheral surface of the intermediate transfer belt 52, and the intermediate transfer belt 52 passes between the cleaning blade 67 and the transport roll 62 while being in contact with the cleaning blade 67. As a result, the toner adhering to the surface is removed and collected.

  On the other hand, a paper feed unit 68 in which the recording paper P is accommodated is provided at the bottom of the housing 12. In the housing 12, a conveyance path 70 for conveying the recording paper P is provided from the paper feeding unit 68 to the paper discharge unit 26. Above the end of the paper feed unit 68 in the arrow X direction, a feed roll 72 that feeds the stored recording paper P to the transport path 70 is provided, and downstream of the feed roll 72 in the transport path 70. Are provided with a pair of transport rolls 74 for transporting the recording paper P one by one.

  Further, an alignment roll 76 that temporarily stops the recording paper P and sends it to the secondary transfer position at a predetermined timing is provided downstream of the transport roll 74 in the transport direction of the recording paper P in the transport path 70. Yes. The secondary transfer position is a position where the intermediate transfer belt 52 and the secondary transfer roll 66 are in contact with each other on the conveyance path 70. Further, on the downstream side of the secondary transfer roll 66 in the conveyance path 70, a fixing device 100 that fixes the toner image onto the recording paper P on which the toner image has been transferred by the secondary transfer roll 66 is provided. Details of the fixing device 100 will be described later.

  A pair of paper discharge rolls 88 that discharge the recording paper P to the paper discharge unit 26 are rotatably provided downstream of the fixing device 100 in the conveyance direction of the recording paper P in the conveyance path 70. In addition, a double-sided conveyance path 71 through which the recording paper P is conveyed and reversed in order to form an image on both sides of the recording paper P is connected to the conveyance path 70.

  The double-sided conveyance path 71 is provided with a plurality of conveyance rolls 92, with the upper end connected to the paper discharge roll 88 side and the lower end connected to the upstream side (front side) of the alignment roll 76. Further, a manual conveyance path 73 for conveying the recording paper P is provided from the manual sheet feeding unit 22 to the upstream side of the alignment roll 76. A pair of paper feed rolls 94 is provided in the manual feed path 73.

  Here, when images are formed on both sides of the recording paper P, the leading end of the recording paper P that has been transported through the transport path 70 and has an image formed on the surface is moved outward from the housing 12 by the paper discharge roll 88. Make it protrude. Subsequently, in a state where the rear end portion of the recording paper P is sandwiched between the paper discharging rolls 88, the paper discharging roll 88 is rotated in the reverse direction and the switching guide (not shown) is operated, whereby the recording paper P is conveyed on the double-sided conveying path. It is conveyed by 71 and returned to the alignment roll 76. Then, after the back side image is formed, the recording paper P is discharged to the paper discharge unit 26.

  On the other hand, in the image forming apparatus 10, a shaft 95 is provided at the lower end portion of the front cover 14. In the image forming apparatus 10, the front cover 14 is opened in the direction of the arrow X by rotating the front cover 14 around the shaft 95. Further, a hinge portion 96 is provided at an end portion (left end portion in the drawing) opposite to the paper discharge portion 26 in the top cover 18, and the top cover 18 is rotated and moved by the hinge portion 96, whereby the top cover is covered. 18 is opened in the arrow Y direction.

  In the image forming apparatus 10, when the front cover 14 is opened, the conveyance path 70 for the recording paper P is opened, and it becomes possible to take out the recording paper P in which the conveyance failure has occurred. In the image forming apparatus 10, the fixing device 100 is opened by opening the front cover 14, and maintenance of the fixing device 100 is possible.

  Further, in the image forming apparatus 10, by rotating the top cover 18 in the arrow Y direction by the hinge portion 96, the intermediate transfer unit 50 moves together with the top cover 18 and the top cover 18 is opened. . When the top cover 18 is opened, each photosensitive unit 30 and each developing unit 36 are exposed so that maintenance such as member replacement can be performed.

  Next, an image forming process in the image forming apparatus 10 will be described.

  As shown in FIG. 1, when the image forming apparatus 10 operates, image data of each color of yellow (Y), magenta (M), cyan (C), and black (K) is supplied from an image processing apparatus (not shown) or from the outside. Are sequentially output to the exposure unit 48.

  Subsequently, as shown in FIG. 2, in each photoconductor unit 30, the photoconductor 32 rotates and the outer peripheral surface of the photoconductor 32 is charged by the charging roll 44. Then, the laser beam LB emitted according to the image data from the exposure unit 48 (see FIG. 1) exposes the outer peripheral surface (front surface) of the photoreceptor 32 charged by the charging roll 44. Thereby, an electrostatic latent image corresponding to the image data of each color is formed on the outer peripheral surface of the photoconductor 32. Further, the electrostatic latent image formed on the outer peripheral surface of the photoreceptor 32 is developed as a toner image corresponding to each color by the developing device 36. Then, the toner images on the outer peripheral surface of each photoconductor 32 are sequentially transferred to the intermediate transfer belt 52 by each primary transfer roll 64 (in the order of Y, M, C, K) and are superimposed.

  On the other hand, as shown in FIG. 1, the recording paper P sent out from the paper supply unit 68 and conveyed through the conveyance path 70 is subjected to multiple transfer and timing of each toner image onto the intermediate transfer belt 52 by the alignment roll 76. Are conveyed to a secondary transfer position (secondary transfer roll 66). The toner image that has been multiplex-transferred onto the intermediate transfer belt 52 is secondarily transferred by the secondary transfer roll 66 onto the recording paper P that has been conveyed to the secondary transfer position.

  Subsequently, the recording paper P onto which the toner image has been transferred is conveyed toward the fixing device 100. In the fixing device 100, the toner image on the recording paper P is fixed on the recording paper P by being heated and pressed by the heating roll 104 and the pressure belt 106. Further, the recording paper P on which the toner image is fixed is discharged to the paper discharge unit 26 as an example.

  When images are formed on both sides of the recording paper P, the image is fixed on the front surface by the fixing device 100, and then the paper discharge roll 88 is rotated in the reverse direction so that the leading edge and the trailing edge of the recording paper P are exchanged. The sheet P is fed into the duplex conveyance path 71. Then, the sheet is fed again from the upstream side of the alignment roll 76 to the conveyance path 70 to perform image formation and fixing on the back surface of the recording paper P.

  Next, the fixing device 100 will be described.

  As shown in FIG. 3A, the fixing device 100 has a housing 102. The housing 102 rotatably supports and covers a heating roll 104 as an example of a heating rotator, and a cover member 102B that rotatably supports and covers a pressure belt 106 as an example of a pressure rotator. It is comprised including. The housing 102 </ b> A and the cover member 102 </ b> B are arranged with an interval in the direction of the arrow X, and this interval is a conveyance path 70 for the recording paper P.

  As an example, the heating roll 104 is a cylindrical member having an arrow Z direction as an axial direction and open at both ends in the arrow Z direction, and is formed on the outer peripheral surface of a thin cylindrical substrate made of iron. It has a multilayer structure in which an elastic layer made of rubber and a release layer containing a fluororesin are stacked. Also, halogen lamps 108 and 109 as examples of heat sources are provided inside the heating roll 104 with an interval from the inner peripheral surface of the heating roll 104 with the arrow Z direction as an axial direction.

  For example, the halogen lamp 108 has a length in the arrow Z direction that is longer than the maximum width of A4 of the recording paper P, and both ends are supported by support members 122 and 123 described later. Further, the halogen lamp 108 generates heat by being supplied with power according to an instruction from the control unit 20 (see FIG. 1), and heats the heating roll 104.

  As an example, the halogen lamp 109 has a length in the arrow Z direction longer than the maximum width of A3 of the recording paper P. That is, the width of the heating area of the heating roll 104 in the arrow Z direction of the halogen lamp 109 is wider than the width of the heating area of the heating roll 104 in the arrow Z direction of the halogen lamp 108. The halogen lamp 109 is supported at both ends by support members 122 and 123 described later. Further, the halogen lamp 109 generates heat by being supplied with power according to an instruction from the control unit 20 (see FIG. 1), and heats the heating roll 104.

  As described above, the halogen lamps 108 and 109 differ in the width of the heating region of the heating roll 104 in the arrow Z direction, but in FIG. 4, their total length in the arrow Z direction (different from the width of the heating region). Are shown as being equal. Further, a temperature sensor (not shown) is provided at the end of the heating roll 104 in the arrow Z direction, and the halogen lamps 108 and 109 are turned on or off based on temperature information detected by the temperature sensor. To be done.

  Here, in the image forming apparatus 10 (see FIG. 1), as an example, regardless of the size of the recording paper P, the heating roll 104 is heated using a halogen lamp 109 having a wide heating area in normal times. When the temperature detected by the temperature sensor (not shown) at the end increases above the set temperature, the control unit 20 (see FIG. 1) turns off the halogen lamp 109 and turns off the halogen lamp 108. Light up. Subsequently, after the temperature at the end of the heating roll 104 is lowered, the halogen lamp 108 is turned off and the halogen lamp 109 is turned on.

  As shown in FIG. 4, side plates 112 and 113 are provided upright in the arrow Y direction at intervals in the arrow Z direction in the casing 102 of the fixing device 100. Bearings 114 and 115 that rotatably support both ends of the heating roll 104 in the arrow Z direction are provided. And both ends of the heating roll 104 are inserted into the bearings 114 and 115. A driving gear 116 is provided at one end (the left end in the figure) of the heating roll 104 in the arrow Z direction.

  In the drive gear 116, the heating roll 104 is inserted into a through-hole 116A (see FIG. 5B) penetrating in the arrow Z direction, and a hole (not shown) formed on the outer peripheral surface of the heating roll 104 is provided. By attaching a protrusion (not shown) protruding inward from the inside of the through hole 116A, it is attached to the heating roll 104. Further, the tooth portion of the drive gear 116 meshes with the tooth portion of the transmission gear 117 that transmits a driving force from a motor (not shown).

  Furthermore, resin support members 122 and 123 fixed by brackets (not shown) are provided in the housing 102 at portions facing both ends of the heating roll 104 in the axial direction (arrow Z direction). . The support members 122 and 123 are formed with two through holes 124A and 124B penetrating in the arrow Z direction at intervals in the arrow Y direction, respectively, and the end of the halogen lamp 108 is inserted into the through hole 124A. By inserting the end of the halogen lamp 109 into the hole 124B, both ends of the halogen lamps 108 and 109 are supported.

  As an example, the pressure belt 106 is an endless belt member having an arrow Z direction as an axial direction and both ends in the arrow Z direction being open, and an outer peripheral surface of a thin cylindrical base material made of polyimide. It has a multilayer structure in which an elastic layer made of silicon rubber and a release layer containing a fluororesin are stacked. Further, both ends of the pressure belt 106 are closed with a conductive resin and are rotatably supported by bearings (not shown) provided on the side plates 112 and 113.

  As shown in FIG. 3A, a holder 126 is provided on the inner side of the pressure belt 106. The holder 126 supports both ends in the arrow Z direction. A felt member 128 impregnated with oil is attached to one end surface in the arrow X direction of the holder 126 (the end surface opposite to the heating roll 104). A part of the felt member 128 is part of the pressure belt 106. Oil as a lubricant is supplied in contact with the inner peripheral surface of the oil. Also, a resin tension applying member 132 for holding the pressure belt 106 in a circular cross section is provided on one end surface of the holder 126 in the arrow Y direction.

  Further, the pressure on the outlet side (downstream side) of the contact area (nip portion N) between the heating roll 104 and the pressure belt 106 is applied to the other end face (end face on the heating roll 104 side) in the arrow X direction of the holder 126. A holding member 134 made of a liquid crystal polymer for raising is attached, and a pressure pad 136 attached to the holding member 134 is provided between the holding member 134 and the pressure belt 106. The pressure belt 106 is brought into contact with the outer peripheral surface of the heating roll 104 by an urging force of a spring or the like (not shown) and is pressed by the pressure pad 136 to form a contact area (nip portion N) with the heating roll 104. Forming.

  Next, the housing 102A will be described.

  As shown in FIG. 3A, the housing 102 </ b> A is made of resin, and is provided with a facing member 142 that has an X-Y cross section of “U” shape and is disposed to face the outer peripheral surface of the heating roll 104. The opposing member 142 is made of resin and is partially reinforced with sheet metal (not shown). The reinforcing sheet metal is included in the housing 102A and the opposing member 142.

  As shown in FIGS. 3A and 3B, an aluminum sheet member 144 as an example of a reflecting surface is attached to a portion facing the outer peripheral surface of the heating roll 104 inside the facing member 142. It has been. As shown in FIG. 4, an aluminum sheet member 146 as an example of a reflecting surface is attached to the side surfaces of the support members 122 and 123 that face the heating roll 104. In the present embodiment, the sheet members 144 and 146 are set to have a higher reflectance of the radiant heat H than the housing 102 and the facing member 142.

  Next, the operation of this embodiment will be described.

  As shown in FIG. 5A, in the fixing device 100, the heating roll 104 is heated by turning on the halogen lamps 108 and 109, and radiant heat H is released from the outer peripheral surface of the heating roll 104. The emitted radiant heat H is reflected by the sheet member 144, is transmitted to the heating roll 104, and is used for heating the heating roll 104. As a result, the temperature holding time of the heating roll 104 becomes longer, the re-lighting of the halogen lamps 108 and 109 is suppressed, and the energy utilization efficiency in heating the heating roll 104 is increased, so that a reduction in energy consumption is suppressed.

  Further, as shown in FIG. 5B, in the fixing device 100, the heating roll 104 is heated by turning on the halogen lamps 108 and 109, and the radiant heat H is released from the axial end of the heating roll 104. The emitted radiant heat H is reflected by the sheet member 146 toward the inside of the heating roll 104, transmitted to the inside of the heating roll 104, and used for heating the heating roll 104. As a result, the temperature holding time of the heating roll 104 becomes longer, the re-lighting of the halogen lamps 108 and 109 is suppressed, and the energy utilization efficiency in heating the heating roll 104 is increased, so that a reduction in energy consumption is suppressed.

  Further, as shown in FIGS. 5A and 5B, in this embodiment, the sheet member 144 is provided on the opposing member 142 and the support member 122 that are made of resin and have a higher thermal resistance than that of the sheet metal (the heat capacity is larger than that of the sheet metal). Since 146 is pasted, the radiant heat H transmitted from the heating roll 104 to the sheet members 144 and 146 is less likely to be consumed by heating the opposing member 142 and the support member 122 itself. Thereby, the temperature rise of the housing 102A is suppressed, and the temperature rise of each part of the image forming apparatus 10 (see FIG. 1) outside the fixing device 100 is also suppressed.

  In addition, this invention is not limited to said embodiment.

  A sheet member 144 may be provided on the inner side of the cover member 102B to suppress a decrease in the temperature of the pressure belt 106. Further, instead of the halogen lamps 108 and 109, an external heating roll for heating the heating roll 104 from the outside may be used. Furthermore, an aluminum member may be polished and used as the reflecting surface. In addition, the sheet member 146 may be provided on only one of the support members 122 and 123. A reflective surface may be formed on the entire inside of the housing 102.

  FIGS. 6A and 6B show a configuration in which a sheet metal 152 is provided instead of the resin facing member 142 and the sheet member 144 of the fixing device 100 as another embodiment. And the electroless nickel plating is given to 152 A of opposing surfaces which oppose the heating roll 104 of the sheet metal 152. FIG. As described above, the sheet metal may be plated to form a reflecting surface, or may be vapor deposited instead of the plating process.

10 Image forming apparatus 32 Photosensitive member (an example of a latent image holding member)
36 Developer (example of development unit)
52 Intermediate transfer belt (an example of transfer means)
64 Primary transfer roll (an example of transfer means)
66 Secondary transfer roll (an example of transfer means)
100 Fixing Device 102 Case 104 Heating Roll (Example of Heating Rotator)
106 Pressure belt (an example of a pressure rotator)
108 Halogen lamp (an example of a heat source)
109 Halogen lamp (an example of a heat source)
144 Sheet member (an example of a reflective surface)

Claims (5)

A heating rotor that emits radiant heat;
A pressure rotator that pressurizes the recording medium with the heating rotator; and
A housing that rotatably accommodates the heating rotator and the pressure rotator;
Have
A fixing device in which a reflection surface that has a higher reflectance than the casing and reflects radiant heat toward the heating rotator is provided inside the casing.   The fixing device according to claim 1, wherein the reflection surface is disposed at a portion facing an outer peripheral surface of the heating rotator. A heat source for heating the heating rotator is provided inside the heating rotator,
The axial end of the heating rotator is opened,
The fixing device according to claim 1, wherein the reflection surface is disposed at a portion facing an axial end portion of the heating rotator.   The fixing device according to claim 1, wherein the housing is made of resin. A latent image holding body for holding the latent image;
A developing unit that develops the latent image with a developer to form a developer image;
Transfer means for transferring the developer image to a recording medium;
5. The developer image on the recording medium that has been transferred and conveyed into the casing is fixed to the recording medium by being sandwiched between the heating rotator and the pressure rotator in the casing. 6. Or a fixing device according to claim 1;
An image forming apparatus.

Images