JP6018979B2 - Fixing device and image forming apparatus having the same - Google Patents

Description

  The present invention relates to a fixing device preferably used for a copying machine, a printer, and the like, and an image forming apparatus including the same.

  Conventionally, a fixing device for fixing a toner image onto a sheet in an electrophotographic image forming apparatus is known. In such an image forming apparatus, printing (image formation) is started when the heating roller of the fixing device reaches a predetermined temperature (warming up is completed).

  By the way, with the recent increase in printing speed, it is desired to further shorten the time required for warm-up. For example, Patent Document 1 discloses a fixing device including a heating roller, a pressure roller that presses against the heating roller to form a fixing nip, and a halogen heater that heats the heating roller from the inside. In this fixing device, the heat capacity is reduced by reducing the thickness of the heating roller, and the temperature reaches a predetermined temperature in a short time.

  Further, for example, Patent Document 2 discloses a heat shield in a state where there is a gap between a heater fixedly disposed inside a rotatable heating roller, a heat shielding member that shields heat from the heater, and the heater. A fixing device including a supporting member that supports the member is disclosed. In this fixing device, the temperature of the heating roller is efficiently raised by reflecting the heat from the heater with a heat shielding member.

JP 2003-177624 A JP 2011-047995 A

  However, the technique described in Patent Document 1 has a problem that heat from the halogen heater is easily radiated from both ends in the axial direction of the heating roller, and the heating roller cannot be efficiently heated.

  In the technique described in Patent Document 2, although heat radiation from the axial end portions of the heating roller is somewhat suppressed by the heat shielding member, heat radiation from the gap formed between the support member and the heater is effectively blocked. I couldn't.

  In addition, there is a possibility that other parts (for example, a housing that accommodates the heating roller, etc.) located near the outer end of the heating roller are excessively heated due to heat radiation from both axial ends of the heating roller. In this case, there is a possibility that deterioration of excessively heated components may be promoted.

  By the way, generally, an inner surface coating material for efficiently absorbing heat from the heater is applied to the inner peripheral surface of the heating roller. When the heating time of the heating roller is increased, volatile organic compounds (VOC, SVOC) may be released from the inner surface coating material. In recent years, it has been desired to further reduce the amount of VOC emission.

  SUMMARY An advantage of some aspects of the invention is to provide a fixing device that suppresses heat diffusion and warms up in a short time, and an image forming apparatus including the fixing device. And

  In order to achieve the above-described object, a fixing device of the present invention rotates around a rotation shaft and has a heating member having an opening at an end portion in the rotation shaft direction, and is provided inside the heating member. A heating element having a heating element that heats the heating element, and a heating element support member that supports the heating element and extends to the outside of the heating member through the opening, and is provided inside the heating member. A reflection member that reflects heat from the heating element toward the opening toward the inside; and a mounting member that is provided so as to cover the opening and into which the heating element support member is loosely inserted. Features.

  According to this configuration, the heat radiated from the heat generating member is reflected by the reflecting member and shielded by the mounting member. Thereby, since the heat radiation from between the mounting member and the heating element support member loosely inserted into the mounting member is suppressed, the heating member can be efficiently heated. That is, the time required for warm-up can be shortened. Further, since diffusion of heat from between the mounting member and the heating element support member is suppressed, for example, excessive heating of other components disposed near the outside of the opening of the heating member is suppressed. be able to. Thereby, deterioration of other components by excessive heating can be suppressed.

  In this case, it is preferable that a reflection portion for reflecting heat from the heat generating member toward the inside is formed on the inner surface of the mounting member.

  According to this configuration, the radiant heat from the heat generating member is reflected by the reflecting portion of the mounting member in addition to the reflecting member. Thereby, heat dissipation from between the mounting member and the heating element support member is suppressed, and the temperature of the heating member can be raised more efficiently.

  In this case, the heating member includes a cylindrical roller, the heating member is provided on the rotating shaft of the heating member, and the mounting member is inserted through the heating element support member. The reflective member is fixed to the heat generating member between the heat generating element and the mounting member, and has a size capable of covering the insertion hole as viewed in the direction of the rotation axis. It is preferable.

  According to this configuration, the reflecting member is fixed to the heat generating member so as to cover the insertion hole from the inside. For this reason, the radiant heat which goes to the edge part of a heating member from a heat generating member can be interrupted | blocked by a reflection member. Thereby, the time required for warm-up can be further shortened. Further, since the heating member can be efficiently heated, the operation time of the heat generating member can be shortened, and the power consumption can be reduced. At the same time, release of VOC and the like from the inner surface coating material of the heating member can be suppressed. Furthermore, since the mounting member and the reflecting member are disposed so as to cover the opening double, diffusion of heat toward the outside of the heating member is effectively suppressed.

  Further, in this case, a driving gear connected to a driving source that rotationally drives the heating member is provided, and the mounting member has a driven gear that meshes with the driving gear, and can rotate integrally with the heating member. preferable.

  According to this configuration, the number of components can be reduced as compared with the case where the member that transmits the driving force from the drive source to the heating member is configured as a separate component. Thereby, simplification and cost reduction of an apparatus can be achieved.

  In this case, it is preferable that a housing for housing the heating member is provided, and the mounting member is fixed to the housing and rotatably supports the heating member.

  According to this configuration, the number of components can be reduced as compared with the case where the member that rotatably supports the heating member is configured as a separate component. Thereby, simplification and cost reduction of an apparatus can be achieved.

  In this case, it is preferable that a housing for housing the heating member is provided, and the mounting member is rotatably supported by the housing and rotates integrally with the heating member.

  According to this configuration, wear of the end portion of the heating member and the mounting member can be suppressed.

  In order to achieve the above object, an image forming apparatus of the present invention includes any one of the fixing devices described above.

  According to this configuration, since heat radiation from the end of the heating member is blocked, the time required for warm-up can be shortened. That is, it is possible to shorten the time from the printing instruction from the user to the completion of printing (image formation). Thereby, usability can be improved.

  According to the present invention, heat diffusion is suppressed and warm-up can be performed in a short time.

FIG. 2 is a cross-sectional view schematically showing the internal structure of the printer according to the first embodiment of the present invention. 1 is a cross-sectional view illustrating a fixing device of a printer according to a first embodiment of the present invention. In the fixing device of the printer according to the first embodiment of the present invention, it is a side sectional view showing a heat roller and its peripheral part. In the fixing device of the printer concerning a 2nd embodiment of the present invention, it is a sectional side view showing a heat roller and its peripheral part.

  Hereinafter, an image forming apparatus including a fixing device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

<First Embodiment>
First, a printer 1 as an image forming apparatus according to the first embodiment will be described with reference to FIG. Here, FIG. 1 is a cross-sectional view schematically showing the internal structure of the printer 1.

  The printer 1 is disposed at a lower portion of a substantially box-shaped apparatus main body 2, and is disposed at the upper end of the apparatus main body 2 for storing paper (not shown) and printed (image formation). And a paper discharge tray 4 for receiving paper.

  An exposure unit 5 composed of a laser scanning unit (LSU) is disposed on the upper right portion of the apparatus main body 2, and an image forming unit 6 is disposed on the left portion of the apparatus main body 2. The image forming unit 6 performs a monochrome image forming process based on, for example, image data transmitted from a personal computer (not shown), and includes a toner container 9 that stores supply toner (black). Yes. The image forming unit 6 includes a charger 8 disposed in the order of a transfer process (see an arrow X in FIG. 1) around a photosensitive drum 7 as an image carrier that is rotatably provided, a developing unit 10, A transfer roller 11 and a cleaning device 12 are included.

  A sheet conveyance path 13 extending in the vertical direction is provided on the left side of the apparatus main body 2 so as to connect the sheet feeding cassette 3 and the sheet discharge tray 4. At the upstream end of the transport path 13, a paper feed unit 14 for taking out paper from the paper feed cassette 3 is provided, and at the downstream part of the transport path 13, a fixing device 16 is provided. On the left side of the transport path 13, a reverse path 17 for duplex printing is provided.

  Here, an image forming operation by the printer 1 will be described. When the printer 1 is turned on, initial settings such as various parameters are executed. When image data is input (print start instruction) from a computer or the like connected to the printer 1, the image data is converted into image data by the exposure device 5 on the surface of the photosensitive drum 7 charged to a predetermined potential by the charger 8. Corresponding exposure (see arrow P in FIG. 1) is performed. As a result, the electrostatic latent image formed on the photosensitive drum 7 is developed into a toner image by the developing device 10. This toner image is transferred onto the paper that has been transported through the transport path 13 in synchronization with the transfer bias applied to the transfer roller 11, and is fixed on the paper by the fixing device 16. The paper on which the toner image is fixed is discharged to the paper discharge tray 4. The toner remaining on the surface of the photosensitive drum 7 after the transfer is removed by the cleaning device 12.

  Next, the fixing device 16 will be described with reference to FIGS. 2 and 3. The fixing device 16 melts and presses the toner constituting the toner image transferred onto the paper and fixes it on the paper. 2 is a sectional view showing the fixing device 16, and FIG. 3 is a side sectional view showing the heat roller 21 and its peripheral portion. In the following description, for the sake of convenience, the front side of the sheet of FIG. 2 and the arrow Fr shown in FIG. 3 (the same applies to FIG. 4) are the front side (front side) of the fixing device 16.

  As shown in FIG. 2, the fixing device 16 includes a substantially box-shaped housing 20, a heat roller 21 as a heating member housed in the lower right portion of the housing 20, and a housing facing the upper left side of the heat roller 21. 20, a press roller 22 accommodated in the housing 20, a discharge roller pair 23 provided in the upper right part of the housing 20, a heater 24 as a heat generating member provided in the heat roller 21, and the axial direction (front-back direction) of the heat roller 21 And a heat shielding structure 25 (see FIG. 3) provided at both ends.

  The housing 20 includes a heat roller housing portion 26 formed on the right side, a press roller housing portion 27 formed on the left side, and a cover member 28 formed so as to cover the top. On the upper right side of the press roller accommodating portion 27, a discharge switch 29 for detecting that the sheet has passed through the transport path 13 or the reverse path 17 is provided.

  The heat roller 21 is accommodated in the heat roller accommodating portion 26. The heat roller 21 has a hollow cylindrical shape that is long in the front-rear direction. Specifically, the heat roller 21 is made of, for example, a metal cylindrical core material such as aluminum or iron, an elastic layer made of silicon rubber or the like and laminated on the outer peripheral surface of the cylindrical core material, and a fluororesin such as PFA. And a release layer formed to cover the elastic layer. An inner surface coating material (black) for efficiently absorbing the heat from the heater 24 is applied to the inner peripheral surface of the heat roller 21 (cylindrical core material). A separation claw 21 a that is urged by urging means (not shown) is disposed on the upper side of the heat roller 21 so as to be in sliding contact with the outer peripheral surface of the heat roller 21. The paper is separated from the outer peripheral surface of the heat roller 21 by the separation claw 21a.

  As shown in FIG. 3, openings 30 a and 30 b are formed at both front and rear ends of the heat roller 21. The heat roller 21 is provided to be rotatable about a rotation axis A extending in the front-rear direction by driving and controlling a drive motor 68 (described later). That is, in this embodiment, the front-rear direction is the rotation axis direction.

  As shown in FIG. 2, the press roller 22 is disposed so as to be parallel to the heat roller 21 and is accommodated in the press roller accommodating portion 27. The press roller 22 includes a cylindrical core material made of the same material as the heat roller 21 described above, an elastic layer, and a release layer. The press roller 22 is urged by an urging means (not shown), and is arranged so as to be in pressure contact with the outer peripheral surface of the heat roller 21. Thereby, a fixing nip N is formed between the heat roller 21 and the press roller 22.

  The upper roller of the discharge roller pair 23 is supported by a roller shaft 23a. The roller shaft 23a supports the cover member 28 so as to be rotatable. The lower roller of the discharge roller pair 23 is pressed against the upper roller.

  The heater 24 is a so-called halogen heater that heats the heat roller 21 from the inside. As shown in FIG. 3, the heater 24 is formed in a substantially cylindrical shape having a smaller diameter than the heat roller 21 and longer in the front-rear direction. The heater 24 is provided on the rotation axis A of the heat roller 21. That is, the heater 24 is provided so as to penetrate the heat roller 21 in the rotation axis direction.

  The heater 24 includes a filament 31 as a heating element and a glass tube 32 as a heating element support member that supports the filament 31.

  The filament 31 is made of, for example, tungsten formed in a coil shape. The length of the filament 31 in the rotation axis direction is formed to be shorter than that of the heat roller 21. That is, the filament 31 is provided inside the heat roller 21. The filament 31 emits light when energized, and heats the heat roller 21 from the inside by radiant heat generated by this light.

  The glass tube 32 is formed so as to cover the filament 31 with, for example, quartz glass. The glass tube 32 is formed to extend to the outside of the heat roller 21 through the openings 30 a and 30 b of the heat roller 21. Specifically, the glass tube 32 includes a cylindrical housing portion 33 that is long in the front-rear direction, sealing portions 34a and 34b that seal both front and rear ends of the housing portion 33, and front and rear portions of the sealing portions 34a and 34b. And mounting portions 35a and 35b extending outward from both ends.

  The length of the housing portion 33 in the direction of the rotation axis is formed to be substantially the same as the heat roller 21 (exactly slightly longer). The accommodating portion 33 accommodates the filament 31 in parallel and encloses a halogen gas. Screw holes 36 are formed in the mounting portions 35a and 35b. The heater 24 is fixed to the housing 20 by screws (not shown) that pass through the screw holes 36.

  As shown in FIG. 3, the heat shielding structure 25 is provided so as to cover the openings 30 a and 30 b of the heat roller 21, and a pair of front and rear mounting members 40 into which the glass tube 32 is loosely inserted, and the heat roller 21. And a pair of front and rear reflection members 41 that reflect heat from the filament 31 toward the openings 30a and 30b toward the inside.

  The pair of front and rear mounting members 40 shield the heat radiated from the heater 24 from leaking from the openings 30a and 30b of the heat roller 21. In the following description, for convenience, the front mounting member 40 is referred to as a “first mounting member 42”, and the rear mounting member 40 is referred to as a “second mounting member 43”.

  The first mounting member 42 is formed of a synthetic resin material having heat insulation properties, and is mounted so as to close the opening 30 a that opens at the front end of the heat roller 21. The first mounting member 42 is disposed on the rear side (inward in the rotation axis direction) of the front sealing portion 34a of the glass tube 32.

  The first mounting member 42 is formed in a substantially bottomed cylindrical shape (cap shape). Specifically, the first mounting member 42 includes a lid portion 50 formed so as to cover the opening 30 a from the front side, a holding portion 51 extending rearward from the outer edge portion of the lid portion 50, and a diameter from the holding portion 51. And a fixing portion 52 protruding outward in the direction.

  The lid part 50 is formed in a substantially disc shape. A circular insertion hole 53 is formed through the center (axial center) of the lid 50. That is, the lid 50 is formed in an annular shape when viewed from the front. The insertion hole 53 is formed such that the front end portion of the glass tube 32 of the heater 24 penetrates freely on the rotation axis A of the heat roller 21. That is, the insertion hole 53 is formed to have a slightly larger diameter than the outer diameter of the glass tube 32 of the heater 24. Therefore, the first mounting member 42 is disposed so as to cover the opening 30 a with the gap G <b> 1 between the glass tube 32 and the lid 50. The (circular) gap G1 between the insertion hole 53 and the glass tube 32 is preferably 2 mm or less.

  The lid 50 is formed with a cylindrical protrusion 54 that slightly protrudes rearward (inward in the rotation axis direction) from the periphery of the insertion hole 53. On the rear surface (inner surface in the rotation axis direction) of the lid portion 50, a reflection portion 55 that reflects light from the heater 24 (filament 31) toward the inside is formed. The reflecting portion 55 is formed in an annular region between the protruding portion 54 and the holding portion 51. The reflection part 55 is curved and formed so as to protrude forward. The reflection portion 55 is formed by coating a heat reflection film (for example, a gold film).

  The holding part 51 is formed in a cylindrical shape, and its inner peripheral surface is in contact with the outer peripheral surface of the heat roller 21. The holding | maintenance part 51 is supporting the front-end part of the heat roller 21 rotatably. That is, the first mounting member 42 is configured as a slide bearing.

  The fixed portion 52 is formed in a flat plate shape extending in a direction orthogonal to the rotation axis direction. The first mounting member 42 is fixed to the housing 20 via a fixing portion 52.

  The second mounting member 43 is formed of a synthetic resin material having heat insulation properties, and is mounted so as to close the opening 30b opened at the rear end of the heat roller 21. The second mounting member 43 is disposed on the front side (in the rotational axis direction) of the sealing portion 34b on the rear side of the glass tube 32.

  Similar to the first mounting member 42 described above, the second mounting member 43 has a lid portion 60 and a holding portion 61 and is formed in a substantially bottomed cylindrical shape (cap shape). Hereinafter, the detailed description of the same configuration as the first mounting member 42 described above will be omitted.

  The lid portion 60 is the same as the lid portion 50 of the first mounting member 42 described above, and an insertion hole 63 is formed through the center (axial center portion), and is formed in an annular shape when viewed from the front. The shape, diameter, and the like of the insertion hole 63 are the same as those of the insertion hole 53 described above. The size of the gap G2 formed between the insertion hole 63 and the glass tube 32 is also the same as that of the gap G1 described above. In addition, on the rear surface (inner side surface in the rotation axis direction) of the lid portion 60, a protruding portion 64 and a reflecting portion 65 are formed in the same manner as the lid portion 50 described above. The reflecting portion 65 is formed to be curved so as to protrude rearward.

  The holding portion 61 is formed in a cylindrical shape, and the inner peripheral surface thereof is fixed to the outer peripheral surface of the heat roller 21. A driven gear 66 is provided on the outer peripheral surface of the holding portion 61. The driven gear 66 meshes with a drive gear 67 fixed to the output shaft of a drive motor 68 as a drive source. Thereby, the heat roller 21 is connected to the drive motor 68 and is rotationally driven by the drive motor 68.

  A bearing member 69 formed in a cylindrical shape with a synthetic resin material having heat insulation is attached to the rear portion of the heat roller 21. The bearing member 69 is disposed adjacent to the front side of the second mounting member 43 and is fixed to the housing 20. The bearing member 69 rotatably supports the rear portion of the heat roller 21. That is, the bearing member 69 is configured as a sliding bearing.

  The pair of front and rear reflecting members 41 suppress the diffusion of heat (radiant heat) to the outside of the heat roller 21 by reflecting the heat radiated from the heater 24. In the following description, for convenience, the front reflecting member 41 is referred to as a “first reflecting member 44”, and the rear reflecting member 41 is referred to as a “second reflecting member 45”.

  The first reflecting member 44 is disposed in the vicinity of the rear (inward in the rotation axis direction) of the opening 30 a formed at the front end of the heat roller 21. Specifically, the first reflecting member 44 is fixed to the glass tube 32 between the filament 31 and the first mounting member 42.

  The first reflecting member 44 is made of a metal material such as aluminum and is formed in a dome shape having a parabolic curved surface that protrudes forward. The first reflecting member 44 extends in the radial direction from the outer peripheral surface of the glass tube 32 and is formed in an annular shape in front view. The first reflecting member 44 has a size capable of covering the insertion hole 53 when viewed in the direction of the rotation axis. That is, the first reflecting member 44 is formed to have a diameter larger than the diameter of the insertion hole 53 and smaller than the inner diameter of the heat roller 21. The first reflecting member 44 has a reflecting surface 44a that reflects light from the heater 24 (filament 31) on the inner side (rear side) in the rotation axis direction. In addition, the coating material which suppresses reflection of light is apply | coated to the surface on the opposite side to the reflective surface 44a.

  The second reflecting member 45 is disposed near the front (inward in the rotation axis direction) of the opening 30 b formed at the rear end of the heat roller 21. Specifically, the second reflecting member 45 is fixed to the glass tube 32 between the filament 31 and the second mounting member 43. That is, the first reflecting member 44 and the second reflecting member 45 are disposed so as to face each other.

  The second reflecting member 45 is made of a metal material such as aluminum and is formed in a dome shape having a parabolic curved surface that protrudes rearward. The second reflecting member 45 extends in the radial direction from the outer peripheral surface of the glass tube 32 and is formed in an annular shape in a rear view. The second reflecting member 45 has a size capable of covering the insertion hole 63 when viewed in the direction of the rotation axis. That is, the second reflecting member 45 is formed to have a diameter larger than the diameter of the insertion hole 63 and smaller than the inner diameter of the heat roller 21. The second reflecting member 45 has a reflecting surface 45a that reflects light from the heater 24 (filament 31) on the inner side (front side) in the rotation axis direction. In addition, the coating material which suppresses reflection of light is apply | coated to the surface on the opposite side to the reflective surface 45a.

  Here, a procedure for fixing a toner image onto a sheet using the fixing device 16 configured as described above will be described. First, a control device (not shown) of the printer 1 drives and controls the drive motor 68 to rotate the second mounting member 43 via the drive gear 67 and the driven gear 66. As a result, the heat roller 21 pivotally supported by the first mounting member 42 and the bearing member 69 rotates integrally with the second mounting member 43.

  Further, the control device energizes the heater 24 to cause the filament 31 to emit light (heat generation). Thereby, the heat roller 21 is heated from the inside by the heater 24. When it is detected that the heat roller 21 has reached a predetermined temperature by a temperature sensor (not shown) or the like, the above-described image forming operation is performed. That is, the sheet on which the toner image is transferred passes through the fixing nip N formed between the heat roller 21 and the press roller 22. Thereby, the toner constituting the toner image is melted and pressurized and fixed on the paper.

  According to the printer 1 including the fixing device 16 according to the first embodiment, the heat radiated from the heater 24 is reflected by the reflecting members 44 and 45 and shielded by the mounting members 42 and 43. . In particular, the reflecting members 44 and 45 are fixed to the heater 24 (glass tube 32) so as to cover the insertion holes 53 and 63 from the inside. For this reason, the radiant heat which goes to the both ends of the heat roller 21 from the heater 24 (filament 31) can be interrupted | blocked by each reflection member 44,45. Thereby, since the heat radiation from between each attachment member 42 and 43 and the glass tube 32 loosely inserted by this (gap G1, G2) is suppressed, the heat roller 21 can be heated efficiently. That is, the time required for warm-up can be shortened. Therefore, it is possible to shorten the time from the printing instruction from the user to the completion of printing (image formation). Thereby, usability can be improved.

  Further, according to the fixing device 16 according to the first embodiment, since the heat roller 21 can be efficiently heated, the operation time of the heater 24 can be shortened, and the power consumption can be reduced. At the same time, release of VOC and the like from the inner surface coating material of the heat roller 21 can be suppressed.

  Further, the first mounting member 42 and the first reflecting member 44 are disposed so as to cover the opening 30a double, and similarly, the second mounting member 43 and the second reflecting member are covered so as to cover the opening 30b double. 45 are arranged. For this reason, the spreading | diffusion of the radiant heat which goes outside the heat roller 21 (each opening part 30a, 30b side) is suppressed effectively. Therefore, for example, it is appropriate that radiant heat is transmitted to the housing 20 (heat roller accommodating portion 26) and the sealing portions 34a and 34b located in the vicinity of the openings 30a and 30b of the heat roller 21 and excessively heated. Can be suppressed. Thereby, deterioration of other components by excessive heating can be suppressed.

Here, a verification experiment performed in order to confirm the effect of suppressing the radiant heat by the fixing device 16 according to the first embodiment will be described. This verification experiment was performed using a printer (FS-1300D) manufactured by Kyocera Document Solutions. In this verification experiment, 20 character images with a printing rate of 5% are output, and the surface temperature (radiant heat temperature) of the housing 20 is measured by a temperature sensor disposed about 10 mm away from the opening 30b of the heat roller 21. did. In addition, this verification experiment was performed in the state which omitted the reflection parts 55 and 65 from each mounting member 42 and 43. FIG. Other conditions for this verification experiment are as follows.
(Experimental example)
Heat roller 21 provided with mounting members 42 and 43 and reflecting members 44 and 45
(Comparative Example 1)
Heat roller in which each mounting member 42, 43 is omitted and each reflecting member 44, 45 is provided (Comparative Example 2)
Heat roller provided with each mounting member 42, 43 and omitting each reflection member 44, 45 (Comparative Example 3)
Heat roller in which each mounting member 42, 43 and each reflecting member 44, 45 are omitted

  As shown in Table 1, according to the heat roller 21 provided with the mounting members 42 and 43 and the reflecting members 44 and 45 according to the experimental example, the surface temperature of the housing 20 (as compared with Comparative Examples 1 to 3) As a result, the radiant heat temperature was kept low. That is, it was confirmed that the diffusion of radiant heat can be effectively suppressed by providing each of the reflecting members 44 and 45.

  By the way, each sealing part 34a, 34b formed in the glass tube 32 of the heater 24 has a heat-resistant temperature (for example, 300 degrees or less). When the heat-resistant temperature is exceeded, the deterioration progresses and the life of the heater 24 is increased. Shorter. On the other hand, according to the fixing device 16 according to the first embodiment, since diffusion of radiant heat can be effectively suppressed, deterioration of the sealing portions 34a and 34b due to excessive temperature rise is suppressed, and the heater 24 is suppressed. It is possible to extend the service life.

  Further, according to the fixing device 16 according to the first embodiment, the radiant heat from the heater 24 is reflected not only by the reflecting members 44 and 45 but also by the reflecting portions 55 and 65 of the mounting members 42 and 43. . Thereby, the heat radiation from the gaps G1 and G2 formed between the mounting members 42 and 43 and the glass tube 32 is suppressed, and the temperature of the heat roller 21 can be raised more efficiently.

  Furthermore, according to the fixing device 16 according to the first embodiment, the reflecting surfaces 44a and 45a of the reflecting members 44 and 45 are formed only on the inner side in the rotation axis direction of the heat roller 21, respectively. It is possible to prevent infrared rays and the like that have passed over the members 44 and 45 from being reflected toward the openings 30a and 30b (outside), respectively. Thereby, it is possible to suppress heat from escaping from the inside of the heat roller 21 to the outside through the gaps G1 and G2 between the heater 24 and the mounting members 42 and 43.

  According to the fixing device 16 according to the first embodiment, the first mounting member 42 is fixed to the housing 20 and rotatably supports the heat roller 21. For this reason, compared with the case where the member which supports the heat roller 21 rotatably is comprised with another component, a number of parts can be reduced. The second mounting member 43 includes a driven gear 55 that meshes with the drive gear 57 and rotates integrally with the heat roller 21. For this reason, compared with the case where the member which transmits the drive force from the drive motor 58 to the heat roller 21 is comprised with another component, a number of parts can be reduced. As a result, the apparatus can be simplified and the cost can be reduced.

  In the fixing device 16 according to the first embodiment, the mounting members 42 and 43 are mounted on both front and rear ends of the heat roller 21. However, the present invention is not limited to this. You may comprise so that the mounting member 40 may be mounted | worn only in either one end.

  In the fixing device 16 according to the first embodiment, the holding portions 51 and 61 of the mounting members 42 and 43 are in contact with the outer peripheral surface of the heat roller 21, but the present invention is not limited to this. Alternatively, the heat roller 21 may be inserted inward from the openings 30 a and 30 b so as to contact the inner peripheral surface of the heat roller 21.

  In the fixing device 16 according to the first embodiment, the heat roller 21 is used as the heating member, but a fixing belt (endless belt) may be used as the heating member instead. In the fixing device 16 according to the first embodiment, the halogen heater is used as the heat generating member (heater 24). However, other heat sources such as a ceramic heater and an IH coil may be used instead.

Second Embodiment
Next, the fixing device 16 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a side sectional view showing the heat roller 21 and its peripheral portion of the fixing device 16 according to the second embodiment. In the following description, the same reference numerals are given to the same configurations as those in the first embodiment described above, and the description thereof is omitted.

  In the fixing device 16 according to the second embodiment, the first mounting member 70 and the bearing member 75 are different from those according to the first embodiment. The first mounting member 70 includes a lid portion 71, a holding portion 72, and a locking portion 73 that protrudes radially outward from the front end portion (the outer end portion in the rotation axis direction) of the holding portion 72, The front end of the heat roller 21 is attached. In addition, since the cover part 71 is the structure similar to the cover part 50 which concerns on 1st Embodiment, the description is abbreviate | omitted.

  The holding portion 72 is formed in a cylindrical shape, and the inner peripheral surface thereof is fixed to the outer peripheral surface of the heat roller 21. A front bearing 74 is attached to the outer peripheral surface of the holding portion 72. The locking portion 73 is formed in, for example, an annular shape so as to contact the side surface of the front bearing 74 and lock the front bearing 74. Thus, the first mounting member 70 is rotatably supported by the housing 20 via the front bearing 74.

  A cylindrical bearing member 75 is attached to the rear portion of the heat roller 21. The bearing member 75 is disposed adjacent to the front side of the second mounting member 43 and is fixed to the outer peripheral surface of the heat roller 21. A rear bearing 76 is attached to the outer peripheral surface of the bearing member 75. Thus, the bearing member 75 is rotatably supported by the housing 20 via the rear bearing 76.

  In the fixing device 16 according to the second embodiment, the first mounting member 70 and the bearing member 75 fixed to the heat roller 21 rotate integrally with the heat roller 21. Thereby, wear of the heat roller 21, the first mounting member 70, and the bearing member 75 can be suppressed.

  In the above first and second embodiments, the case where the present invention is applied to the printer 1 has been described, but the present invention is not limited to this. For example, the configuration of the present invention may be applied to other image forming apparatuses such as a copying machine, a facsimile machine, and a multifunction machine.

  In the first and second embodiments, the driven gear 66 is provided in the second mounting member 43, but the present invention is not limited to this. For example, the second mounting member 43 may have the same configuration as the first mounting members 42 and 70. In this case, the driven gear 66 is fixed to the outer peripheral surface of the heat roller 21, for example.

  The description of each embodiment describes a preferred embodiment of the printer 1 provided with the fixing device 16 according to the present invention, and thus may have various technically preferable limitations. The technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. Furthermore, the constituent elements in the respective embodiments can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. The description does not limit the content of the invention described in the claims.

1 Printer (image forming device)
16 Fixing device 20 Housing 21 Heat roller (heating member)
24 Heater (heat generating member)
30a, 30b Opening 31 Filament (heating element)
32 Glass tube (heating element support member)
DESCRIPTION OF SYMBOLS 40 Mounting member 41 Reflecting member 42,70 1st mounting member 43 2nd mounting member 44 1st reflecting member 45 2nd reflecting member 53,63 Insertion hole 55,65 Reflecting part 66 Driven gear 67 Drive gear 68 Drive motor (drive source) )

Claims (6)

A heating member that rotates about a rotation axis and has an opening at an end in the rotation axis direction;
A heating element provided inside the heating member and having a heating element that heats the heating member, and a heating element support member that supports the heating element and extends to the outside of the heating member through the opening. Members,
A reflective member that is provided inside the heating member and reflects heat toward the opening from the heating element toward the inside;
A mounting member provided so as to cover the opening, and the heating element support member loosely inserted ,
The heating element emits light and heats the heating member from the inside by radiant heat,
On the inner surface of the mounting member, a reflection portion that reflects light from the heating element toward the inside is formed,
The reflecting member is fixed to the heating member between the heating element and the mounting member, and is formed in a dome shape having a parabolic curved surface that is convex toward the opening,
The reflective member has a reflective surface that reflects light from the heating element on a side opposite to the opening, and a coating material that suppresses reflection of light from the heating element on a surface opposite to the reflective surface Applied and
The fixing device is characterized in that the reflecting portion is curved so as to be convex toward the outside of the heating member . The heating member has a cylindrical roller,
The heating member is provided on the rotating shaft of the heating member,
The mounting member has an insertion hole through which the heating element support member passes,
The reflecting member fixing device according to the be in front Symbol rotation axis direction as viewed covering the through hole has a size capable to claim 1, wherein. A drive gear connected to a drive source for rotationally driving the heating member;
It said mounting member includes a driven gear which meshes with the drive gear, a fixing device according to claim 1 or 2, characterized in that rotating the heating member integrally. A housing for housing the heating member;
The mounting member is fixed to said housing, a fixing device according to claim 1 or 2, characterized in that rotatably supports the heating member. A housing for housing the heating member;
The mounting member, the rotatably supported on the housing, the fixing device according to claim 1 or 2, characterized in that rotating the heating member integrally. An image forming apparatus characterized in that it comprises a fixing device according to any one of claims 1 to 5.

Images