JP6247029B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a fixing device configured to heat a hollow roller from the inside, and an image forming apparatus including the same.

  The electrophotographic image forming apparatus includes a fixing device. In the fixing device, the paper on which the toner image is transferred is heated and pressurized, so that the toner melts and adheres to the paper (for example, see Patent Document 1). .) Some fixing devices include a cover member that suppresses heat from escaping from the frame in addition to a heating roller that heats the sheet and a frame that surrounds the heating roller. Since the fixing device includes the cover member, the heating roller is kept warm, and the time until the heating roller reaches a predetermined temperature at the time of activation can be shortened and energy saving can be achieved.

  In recent years, there has been a demand for miniaturization of image forming apparatuses, and it is conceivable to omit a cover member in order to meet the demand for miniaturization. In the conventional fixing device described in Patent Document 1, a guide portion that slides with respect to a guide rail of the main body when inserted into the main body of the image forming apparatus is provided on the cover member of the fixing device. In such a fixing device, since the cover member is omitted, the fixing device is further downsized.

JP 2009-42735 A

  However, in the conventional fixing device, when the cover member is omitted, the performance of retaining the heating roller is lowered, and the heat of the heating roller easily escapes to the outside of the fixing device. For this reason, the problem that the time until a heating roller reaches | attains predetermined temperature at the time of start-up and reduction in energy efficiency arises.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing device capable of suppressing a reduction in performance of keeping a roller heat while reducing the size, and an image forming apparatus including the same.

  The fixing device according to the present invention includes a roller, a heating member, and a holding member. The roller has a hollow shape having an opening surface at an end portion in the axial direction. The heating member is disposed inside the roller so as to extend in the axial direction, and heats the roller from the inside. The holding member has a holding portion that holds the end portion in the axial direction of the heating member at a fixed position with respect to the roller, and a covering portion that covers at least a part of the opening surface.

  In this configuration, the heat generated by the heating member in the roller is prevented from escaping from the opening surface by the holding member. For this reason, even when a cover member is not provided, the fall of the performance which heats a roller is suppressed. Further, since the cover member is not provided, it is possible to reduce the size of the fixing device.

  In the above configuration, the fixing device is inserted into the main body portion of the image forming apparatus by sliding in a predetermined direction, and the holding member further includes a guide portion that slides along a guide rail included in the main body portion. Can be configured.

  In this configuration, the holding member that holds the heating member also has a guide function for being inserted into the main body in addition to the function of holding the roller. Since one member has a plurality of functions, space saving and the number of parts can be reduced.

  Moreover, it is preferable that a holding member further has a wiring path part which comprises the laying path | route of the electrical wiring which supplies electric power to a heating member.

  In this configuration, the holding member that holds the heating member also has a wiring path configuration function in addition to the function of holding the roller. Since one member has a plurality of functions, space saving and the number of parts can be reduced.

  Furthermore, the guide portion has a plate shape extending in the sliding direction so as to slide on the guide rail, and the holding member further includes a wiring path portion that constitutes an electric wiring laying path for supplying electric power to the heating member, The wiring path portion can be configured to include the upper surface of the plate-like portion.

  In this configuration, the holding member that holds the heating member has not only a function of holding the roller, but also a guide function for insertion into the main body and a wiring path configuration function. Further, the plate-like portion is used for both the guide function and the wiring path configuration function. For this reason, further space saving and reduction of the number of parts can be achieved.

  Further, the wiring path portion can be configured to have one or more locking portions that lock the electric wiring. In this configuration, the electric wiring is more stably held by the holding member.

  Furthermore, it is preferable that the covering portion covers the entire opening surface. According to this configuration, the holding member prevents the heat generated by the heating member in the roller from escaping from the opening surface. For this reason, even when a cover member is not provided, the fall of the performance which heats a roller is suppressed more.

  The image forming apparatus of the present invention includes the fixing device having any one of the above-described configurations.

  In this configuration, the heat generated by the heating member in the roller is prevented from escaping from the opening surface by the holding member. For this reason, even when the cover member is not provided, a decrease in the performance of keeping the heat of the roller of the fixing device is suppressed. Further, since the cover member is not provided, it is possible to reduce the size of the fixing device.

  According to the present invention, it is possible to suppress a decrease in the performance of heat retaining the roller while reducing the size.

1 is a diagram illustrating a schematic configuration of an image forming apparatus including a fixing device according to a first embodiment of the present invention. FIG. 6 is a perspective view showing an end portion of a heating roller provided in the fixing device. FIG. 4 is a perspective view showing an end portion of the fixing device in a state where a holding member is attached. FIG. 6 is a perspective view illustrating a state in which the holding member slides with respect to the main body of the image forming apparatus. FIG. 6 is a perspective view showing a state where electrical wiring of the fixing device is laid. It is a perspective view which shows the structure of the holding member with which the fixing device which concerns on 2nd Embodiment is equipped.

  As shown in FIG. 1, a fixing device 10 according to a first embodiment of the present invention is mounted on an electrophotographic image forming apparatus 100. The image forming apparatus 100 includes an image reading unit 110, an image forming unit 120, and a paper feeding unit 130.

  The image reading unit 110 reads an image of a document and generates image data.

  The image forming unit 120 includes four image forming stations 30A, 30B, 30C, and 30D, an optical scanning device 3, an intermediate transfer unit 40, a secondary transfer unit 50, a fixing device 10, and a paper discharge tray 62.

  The intermediate transfer unit 40 includes an intermediate transfer belt 41, a driving roller 42, and a driven roller 43. The intermediate transfer belt 41 is stretched between the driving roller 42 and the driven roller 43 and moves around the loop path.

  The image forming stations 30 </ b> A to 30 </ b> D are arranged in a line along the intermediate transfer belt 41. The image forming stations 30B to 30D are formed in substantially the same manner as the image forming station 30A.

  The image forming station 30A includes a photosensitive drum 1A, a charger 2A, a developing device 4A, a primary transfer roller 5A, and a cleaning unit 6A. The charger 2A charges the peripheral surface of the photosensitive drum 1A to a predetermined potential. The optical scanning device 3 forms an electrostatic latent image on the peripheral surface of the photosensitive drum 1A by irradiating a laser beam based on the image data. The developing device 4A supplies toner to the peripheral surface of the photosensitive drum 1A to visualize the electrostatic latent image and form a toner image.

  The primary transfer roller 5A is disposed so as to face the respective photosensitive drums 1A of the image forming stations 30A to 30D with the intermediate transfer belt 41 interposed therebetween. Each of the positions where the primary transfer roller 5A and the respective photosensitive drums 1A of the image forming stations 30A to 30D face each other is a primary transfer position. The primary transfer roller 5 </ b> A applies a primary transfer voltage to primarily transfer the toner image formed on the peripheral surface of the photosensitive drum 1 </ b> A to the outer peripheral surface of the intermediate transfer belt 41 at each primary transfer position.

  The black, cyan, magenta, and yellow toner images formed in each of the image forming stations 30 </ b> A to 30 </ b> D are primarily transferred so as to overlap each other on the outer peripheral surface of the intermediate transfer belt 41. An image is formed.

  The toner image formed on the outer peripheral surface of the intermediate transfer belt 41 is conveyed to a secondary transfer position where the intermediate transfer belt 41 and the secondary transfer unit 50 face each other as the intermediate transfer belt 41 rotates.

  The paper feed unit 130 includes a paper feed cassette 131 and a manual feed tray 132, and supplies paper one by one from the selected one of the paper feed cassette 131 and the manual feed tray 132 to the paper transport path 61. The paper transport path 61 extends from the paper feed cassette 131 and the manual feed tray 132 to the paper discharge tray 62 via the secondary transfer position and the fixing device 10.

  The secondary transfer unit 50 includes a secondary transfer roller 51. The secondary transfer unit 50 applies a secondary transfer voltage to the secondary transfer roller 51 to secondarily transfer the toner image carried on the outer peripheral surface of the intermediate transfer belt 41 to a sheet.

  The fixing device 10 includes a heating roller 11 and a pressure roller 12. The heating roller 11 and the pressure roller 12 are in pressure contact with each other. The fixing device 10 firmly and firmly fixes the toner to the sheet by heating and pressing the sheet conveyed between the heating roller 11 and the pressure roller 12.

  The paper to which the toner image is fixed in the fixing device 10 is discharged to the paper discharge tray 62 with the image surface facing downward.

  As shown in FIG. 2, the fixing device 10 further includes a resin frame 13 that surrounds the peripheral surface of the heating roller 11. The frame 13 opens a region where the peripheral surface of the heating roller 11 faces the peripheral surface of the pressure roller 12.

  The heating roller 11 has a hollow shape having an opening surface 111 at an end in the axial direction 91. A heater lamp 14 is disposed inside the heating roller 11. The heater lamp 14 is disposed so as to extend in the axial direction 91 and heats the peripheral surface of the heating roller 11 from the inside. The heater lamp 14 is an example of a heating member that heats the heating roller 11 from the inside.

  As shown in FIG. 3, the fixing device 10 further includes a holding member 20. The holding members 20 are provided at both ends of the heating roller 11 in the axial direction 91, respectively. The holding member 20 includes a holding part 21, a covering part 22, a guide part 23, and a wiring path part 24. The holding member 20 is attached to the frame 13.

  The holding part 21 has a tubular shape. An end portion of the heater lamp 14 in the axial direction 91 is inserted into the holding portion 21 and held. As a result, the end of the heater lamp 14 in the axial direction 91 is held at a fixed position with respect to the heating roller 11.

  The covering portion 22 is formed so as to cover at least a part of the opening surface 111 of the heating roller 11. In the first embodiment, the covering portion 22 has a petri dish shape, that is, an extremely shallow cylindrical container shape having a disk portion and a peripheral surface portion rising from the outer edge of the disk portion, and is formed on a small diameter portion at the end of the heating roller 11. It is close to non-contact from the outside and covers the entire opening surface 111.

  Thus, the holding member 20 suppresses the heat generated by the heater lamp 14 in the heating roller 11 from escaping from the opening surface 111. For this reason, even when the fixing device 10 is not provided with a cover member that prevents heat from escaping from the frame 13 in addition to the frame 13, a decrease in the performance of retaining the heating roller 11 is suppressed. Further, since the cover member is not provided, the fixing device 10 can be reduced in size.

  As shown in FIG. 4, the fixing device 10 is configured to be detachable by sliding in the main body 101 of the image forming apparatus 100 in a predetermined direction. The fixing device 10 is slidably inserted into and removed from the main body 101 during maintenance such as repair or replacement of parts. The main body 101 includes a guide rail 102. The guide rail 102 extends in the sliding direction 92 of the fixing device 10 with respect to the main body 101. As an example, the guide rail 102 has a plate shape. The slide direction 92 is a direction orthogonal to the axial direction 91, and is a horizontal direction in the first embodiment. In FIG. 4, most of the members of the fixing device 10 other than the holding member 20 are not shown.

  The guide part 23 extends in the slide direction 92 so as to slide on the guide rail 102. In the first embodiment, the guide portion 23 has a plate shape extending in the sliding direction 92.

  As described above, the holding member 20 that holds the heater lamp 14 has a guide function for inserting and removing the main body 101 in addition to the function of holding the heating roller 11. Since one member has a plurality of functions, it is possible to save space and reduce the number of parts.

  As shown in FIG. 5, the electrical wiring 141 that supplies power to the heater lamp 14 is connected to the end portion of the heater lamp 14 in the axial direction 91. In FIG. 5, most of the members of the fixing device 10 other than the holding member 20 are not shown.

  The wiring path portion 24 constitutes a laying path for the electrical wiring 141. The wiring path portion 24 includes an upper surface 241 of the guide portion 23 and one or more locking portions 242. The locking part 242 locks the electric wiring 141 on the upper surface of the guide part 23. In the first embodiment, the locking portion 242 has a shape protruding upward from the upper surface 241 of the guide portion 23.

  As described above, the holding member 20 that holds the heater lamp 14 has a guide function for inserting and removing from the main body 101 and a wiring path configuration function in addition to the function of holding the heating roller 11. Further, the guide portion 23 is used for both a guide function and a wiring path configuration function. For this reason, it is possible to further reduce the space and reduce the number of parts. Further, since the wiring route portion 24 has the locking portion 242, the electric wiring is more stably held in the wiring route portion 24 and can be routed to a desired route.

  FIG. 6 shows a holding member 20A provided in the fixing device 10 according to the second embodiment. In the holding member 20 </ b> A, the covering portion 22 </ b> A has a disk shape and is close to the opening surface 111 in a non-contact manner. The holding portion 21A is a hole provided in the central portion of the covering portion 22A. The end portion in the axial direction 91 of the heater lamp 14 is held by the holding portion 21A by being inserted into the hole portion.

  According to the holding member 20A according to the second embodiment, the configuration of the holding member 20A can be simplified.

  In addition, the guide part 23 is provided in the structure which has the plate-shaped part extended in the slide direction 92, and the rib provided in the lower surface of the plate-shaped part, and extended in the slide direction 92, and the lower surface of the plate-shaped part and the plate-shaped part. A structure having a roller can also be used. When the guide part 23 includes a plate-like part, the wiring path part 24 is configured to include the upper surface of the plate-like part.

  The covering portions 22 and 22A of the holding member 20 preferably cover the entire opening surface 111. However, if the cover portions 22 and 22A are configured to cover at least a part of the opening surface 111, the fixing device 10 can be heated while being downsized. The effect that the fall of the performance which heat-retains the roller 11 can be suppressed can be show | played.

  When the pressure roller 12 includes a heating member such as a heat lamp 14 inside, the present invention can also be applied to the pressure roller 12 to keep the pressure roller 12 warm while reducing the size of the fixing device 10. The effect that the fall of performance can be suppressed can be show | played.

  It is conceivable to construct a new embodiment by combining the technical features of the above-described embodiments.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Fixing device 11 Heating roller 111 Opening surface 12 Pressure roller 13 Frame 14 Heater lamp 141 Electric wiring 20, 20A Holding member 21, 21A Holding part 22, 22A Covering part 23 Guide part 24 Wiring path part 241 Upper surface 242 Locking part 100 Image forming apparatus 101 Main unit 102 Guide rail 91 Axial direction 92 Slide direction

Claims (4)

In the fixing device inserted into the main body of the image forming apparatus,
A hollow roller having an opening at the end in the axial direction;
A heating member disposed inside the roller so as to extend in the axial direction, and heating the roller from the inside;
A holding member that holds the axial end of the heating member at a fixed location with respect to the roller, and a holding member that covers at least a part of the opening surface,
The holding member may have a guide portion for sliding along the body portion of the guide rail,
The guide portion presents a plate-like portion extending in the sliding direction so that the lower surface slides on the guide rail,
The holding member further includes a wiring path portion constituting a laying path of electric wiring for supplying electric power to the heating member,
The wiring path portion includes a fixing device including an upper surface of the plate-like portion . The fixing device according to claim 1, wherein the wiring path portion includes one or more locking portions that lock the electric wiring . The cover portion covers the entire surface of the opening surface, the fixing device according to claim 1 or 2. An image forming apparatus comprising the fixing device according to claim 1 .

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