JP2015031853A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to allow a fixing unit to be safely removed from a mounting section, while preventing damage or injury.SOLUTION: While a sheet is conveyed from a paper-feed section 5 to a paper-discharge tray 37, an unfixed toner image carried on a transfer belt 8 is transferred to the sheet by a secondary transfer roller 24, and thermally fixed through a belt-type fixing unit 6. A guide support rail 51 is arranged with an installation port set higher at an inclination angle of 10-30° with respect to a horizontal plane of a printer 1 so that the belt-type fixing unit 6 can be drawn out during maintenance. The guide support rail 51 is inclined. In drawing out the belt-type fixing unit 6 obliquely upward, an operator feels weight of the belt-type fixing unit 6 and supports the belt-type fixing unit 6 with both hands, accordingly. Damage to a device or injury of the operator can be prevented, while preventing the belt-type fixing unit 6 from falling outside the device.

Description

  The present invention relates to an image forming apparatus in which a fixing unit can be safely removed from a mounting portion, and more particularly, to an image forming apparatus in which a fixing unit is inserted and removed along a recording surface of a conveyed recording medium.

  A wide variety of image forming apparatuses that form toner images on an image carrier by using an electrophotographic method using toner, transfer the toner images onto paper, and fix the transferred toner images on paper with a fixing device. Are known.

  Such an image forming apparatus includes a plurality of internal devices such as a belt unit, an image forming unit, and a fixing unit in a detachable manner. At the time of maintenance work of these internal devices, the internal device is removed from the mounting portion of the device main body and removed, and repaired or replaced with a new one and remounted on the mounting portion.

  At that time, since many internal devices are heavy, when the internal device is removed from the mounting portion and taken out, the internal device may be removed from the hand when it is taken out and the internal device may be damaged. In order to prevent such a problem, for example, a configuration has been proposed in which when the fixing unit is taken out of the apparatus main body, the cradle on which the fixing unit is placed and pulled out is inclined so that it can be easily taken out (for example, Patent Document 1).

JP 2005-266157 A

  However, the prior art of Patent Document 1 has a problem that the structure of the cradle rail and the cradle itself is complicated when pulled out to the outside, and the load on the assembly process in the factory is large.

  By the way, when the fixing unit is removed from the apparatus main body, the direction when removing the fixing unit is either the short side or the long side of the fixing unit. It is designed accordingly.

  The prior art disclosed in Patent Document 1 is premised on an apparatus in which the direction in which the fixing unit is removed is perpendicular to the paper surface of the sheet to be conveyed, that is, in the short direction of the fixing unit.

  Here, when the fixing unit is removed in the short direction as in Patent Document 1, it is generally easy to adopt a structure in which both ends of the fixing unit are supported and removed with both hands, and there is an opportunity to remove from the hand. Relatively few.

  Therefore, in the above-mentioned patent document 1, there is no description regarding removal in the longitudinal direction of the fixing unit, that is, insertion / removal of the fixing unit along the paper surface of the sheet to be conveyed, and a technical idea applied in such a case. There are no issues.

  On the other hand, when the fixing unit is removed in the longitudinal direction, the handle formed on the front side is often grasped and pulled out with one hand, so that the fixing can be done soon without being supported by the other hand even if the other hand has a momentum during the pulling out operation. There is a specific problem that the unit is separated from the apparatus main body at once and dropped by its weight.

  In order to solve the above-described problems, the present invention provides an image forming apparatus in which the fixing unit can be removed from the mounting portion without error, and damage to the apparatus and injury to the operator can be prevented.

An image forming apparatus according to the present invention includes a fixing unit that fixes an unfixed toner image on a recording medium on which an unfixed toner image is transferred and conveyed in an image transfer unit, and a recording surface of the conveyed recording medium. A fixing unit mounting portion for detachably mounting the fixing unit, and the fixing unit mounting portion engages with the fixing unit and is positioned at a lower position in a direction perpendicular to the mounting port from the mounting port of the fixing unit. It has an insertion / removal guide part that is inclined to reach the mounting completion position of
It is configured as follows.

  The fixing unit includes, for example, a unit main body, a plurality of fixing rollers including a heat roller, a fixing belt stretched between the plurality of fixing rollers, and one of the fixing rollers via the fixing belt. And a pressing roller that is in pressure contact.

  In this case, the plurality of fixing rollers and the pressing roller are arranged on the recording surface of the recording medium in which the axial direction of each of the rollers is conveyed when the fixing unit is mounted on the fixing unit mounting portion. The unit main body is arranged along the direction perpendicular to the transport direction.

  The present invention is advantageous in that the fixing unit can be removed from the mounting portion without error, and damage to the apparatus and injury to the operator can be prevented.

1 is a cross-sectional view illustrating an internal configuration of a full-color printer (image forming apparatus) including a fixing unit mounting portion (an inclined insertion / removal guide portion) according to Embodiment 1 of the present invention. 1 is an external perspective view of a full color printer including a fixing unit mounting portion according to Embodiment 1. (A) And (b) is a perspective view of the vicinity of the fixing unit mounting portion shown by opening the front door of the full-color printer according to the first embodiment and a diagram for explaining the insertion / removal direction of the fixing unit. (A) thru | or (c) is a figure explaining the procedure which takes out and operates the full color printer provided with the fixing unit mounting part which concerns on Example 1, and this fixing unit from the apparatus main body (printer 1) of a full color printer. (A) thru | or (c) is a figure explaining the procedure which takes out and operates the full-color printer and fixing unit which concern on a prior art example from the printer P. FIG.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a cross-sectional view illustrating an internal configuration of a full-color printer (image forming apparatus) including a fixing unit mounting portion including an inclined insertion / removal guide portion according to the first embodiment.

  A printer 1 shown in FIG. 1 is an electrophotographic secondary transfer type tandem color image forming apparatus, and includes an image forming unit 2, a transfer belt unit 3, a toner supply unit 4, a paper feeding unit 5, a belt type thermal image forming apparatus. The fixing unit 6 and the duplex printing transport unit 7 are configured.

  The image forming unit 2 is in contact with the lower running surface 8a of the transfer belt 8 of the transfer belt unit 3 and has four developing devices 9 (9k, 9c, 9m, 9y) arranged in a multistage manner from right to left in FIG. Configured. The image forming unit 2 is held on the frame of the printer 1 so as to be movable up and down from a printing execution position shown in FIG. 1 to a maintenance position below it.

  Of the four developing devices 9, three developing devices 9c, 9m, and 9y on the upstream side (the left side in the figure) are cyan (C), magenta (M), and yellow (Y), which are subtractive three primary colors, respectively. A mono-color image is formed with the color toner, and the developing device 9k forms a monochrome image mainly with black (K) toner used for characters and dark portions of the image.

  Each of the developing devices 9 has the same configuration except for the color of the toner that develops the image. Therefore, the configuration of the developing device 9y for yellow (Y) toner will be described below as an example.

  The developing device 9 includes a photosensitive drum 10 at the top. The photosensitive drum 10 has a peripheral surface made of, for example, an organic photoconductive material. A cleaner 11, a charging roller 12, an optical writing head 13, and a developing roller 15 of the developing device 14 are disposed in contact with or around the periphery of the photosensitive drum 10.

  The developing device 14 includes a housing 16 that covers the outside, a partition wall 17 provided inside, a developing roller 15, a first stirring and conveying screw 18, and a second stirring and conveying screw 19. Although not specifically shown, the first and second agitating and conveying screws 18 and 19 include a screw shaft and a fin that is integrally formed with the screw shaft and rotates.

  The developing unit 14 includes a toner cartridge 21 of the toner supply unit 4 disposed above the transfer belt unit 3, and black (K), cyan (C), K, C, M, and Y shown in FIG. Either magenta (M) or yellow (Y) toner is supplied.

  The transfer belt unit 3 has an endless transfer belt 8 that extends in the shape of a flat loop in the left-right direction in the figure at approximately the center of the main unit, and the transfer belt 8 is stretched over the transfer belt 8. A driving roller 22 and a driven roller 23 are provided to circulate and move counterclockwise as indicated by an arrow a in the figure.

  A secondary transfer roller 24 is brought into pressure contact with the driving roller 22 via the transfer belt 8, and a secondary transfer toner image on the transfer belt 8 is secondarily transferred to a sheet as a transfer medium conveyed here. The next transfer portion is formed.

  The transfer belt 8 includes a primary transfer roller 25 integrated with the unit. The primary transfer roller 25 is disposed so as to sandwich the transfer belt 8 with respect to the photosensitive drum 10.

  The primary transfer roller 25 directly transfers (primary transfer) the toner image to the lower running surface 8a of the transfer belt 8 that circulates downward. The transfer belt 8 conveys the toner image to the secondary transfer unit in order to further transfer (secondary transfer) the toner image to a sheet.

  Further, a belt cleaner 26 is disposed on the transfer belt 8 so as to abut on the surface of the driven roller 23. Below the belt cleaner 26, a waste toner collecting container 27 for storing waste toner removed from the transfer belt 8 by the belt cleaner 26 is detachably disposed.

  The toner supply unit 4 includes the above-described four toner cartridges 21 disposed above the upper running surface of the transfer belt 8. Although not particularly shown, the toner supply unit 4 is held on the frame of the printer 1 so as to be able to move up and down from the printing execution position shown in FIG. 1 to a maintenance position above it.

  The four toner cartridges 21 of the toner supply unit 4 contain black (K), cyan (C), magenta (M), and yellow (Y) toner, respectively.

  These toner cartridges 21 are detachably attached to and removed from the printer 1 in the front direction, that is, the front side in the depth direction of the drawing. The toner cartridge 21 has a toner discharge port for supplying toner to the developing unit 9 although it is not visible in FIG.

  When the toner cartridge 21 is mounted on the printer 1, the toner discharge port communicates with a toner supply path extending upward from the rear of the developing device 9, and supplies toner to the developing device 9 through the toner supply path. To do. Although not visible in FIG. 1 because of a cross-sectional view, the toner supply path is arranged around the rear of the transfer belt unit 3.

  On the left side of the toner supply unit 4, an electrical unit 29 is disposed from the left side to the upper side of the belt cleaner 26. A circuit board on which a control device composed of a plurality of electronic components is mounted is mounted on the electrical component 29.

  The paper feed unit 5 includes one paper feed cassette 31. A paper take-out roller 32, a feed roller 33, a separating roller 34, and a standby conveyance roller pair 35 are disposed in the vicinity of the paper feed opening (right side of the drawing) of the paper feed cassette 31.

  The secondary transfer portion described above is formed in the paper conveyance direction (vertical upward direction in the drawing) of the standby conveyance roller pair 35. A belt-type heat fixing unit 6 is disposed downstream (upward in the drawing) of the secondary transfer portion.

  The belt-type heat fixing unit 6 includes a fixing roller 6a and a heat roller 6b in a fixing frame 6e, and a fixing belt 6c is stretched over the fixing roller 6a and the heat roller 6b. A pressing roller 6d is pressed against the fixing roller 6a via a fixing belt 6c to form a fixing nip portion.

  On the further downstream side of the belt-type heat fixing unit 6, a pair of carry-out rollers 36 for carrying out the fixed paper from the belt-type heat fixing unit 6, and a paper discharge tray 37 formed on the upper surface of the apparatus. A paper discharge roller pair 38 for paper discharge is provided.

  The conveyance unit 7 for double-sided printing also serves as an opening / closing member whose outer surface (right outer surface in the drawing) opens or shields the inside of the printer 1 from the side surface to the outside.

  This double-sided printing transport unit 7 has a return start path 39a that branches rightward in the figure from just before the discharge roller pair 38, a return intermediate path 39b that bends downward, and further bends leftward in the end to finally return. A return path 39 having a return terminal path 39c for inverting the paper is provided.

  In the middle of the return path 39, five pairs of return rollers 41 (41a, 41b, 41c, 41d, 41e) are arranged. The exit of the return end path 39c joins the conveyance path to the standby conveyance roller pair 35 corresponding to the paper feed cassette 31 of the paper feed section 5.

  FIG. 2 is an external perspective view of the printer 1 described above. In FIG. 2, the same components as in FIG. 1 are given the same reference numerals as in FIG. As shown in FIG. 2, the printer 1 includes a front door 42 at the front, and the front surface of the paper cassette 31 is exposed to the outside below the front door 42, that is, at the bottom of the front surface of the printer 1.

  A grip handle 43 is provided on the front surface of the paper cassette 31. The front door 42 can be opened by inserting a finger into the back of the upper space 44 of the space formed above and below the grip of the handle 43 and pulling the front door 42 toward the front.

  The right side surface of the printer 1 is provided with an outer surface portion of the duplex printing conveyance unit 7 shown in FIG. A handle 45 is provided above the outer surface portion. The above-described paper discharge tray 37 is formed at the center of the upper surface of the printer 1, and the operation panel unit 46 is formed at the front.

  FIGS. 3A and 3B are a perspective view of the vicinity of the fixing unit mounting portion shown by opening the front door 42 of the printer 1 and a view for explaining the insertion / removal direction of the belt-type thermal fixing unit 6. In FIGS. 3A and 3B, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals as those shown in FIGS.

  As shown in FIG. 3A, when the front door 42 is opened from the front of the printer 1, the front door 42 is opened almost horizontally and is fixed in position. Above the transfer belt unit 3, four toner cartridges 221k, 21c, 21m, and 21y are replaceably disposed, and a belt-type heat fixing unit 6 is disposed on the right side thereof.

  Below the transfer belt unit 3, the four developing devices 9k, 9c, 9m, and 9y are arranged so that they can be removed during maintenance. A handle 46 is formed at the front of the frame of the transfer belt unit 3. Further, the belt-type heat fixing unit 6 is also provided with a handle 50 (see also FIG. 3B and FIG. 4 to be described later) although it cannot be clearly seen in FIG.

  In FIG. 3B, the user opens the front door 42 in front of the printer 1 as indicated by an arrow b, and puts the hand on the handle 50 of the belt-type heat fixing unit 6 inside, so that the belt-type heat fixing unit 6 In detail, the both side end portions of the lower surface are pulled out toward the front as indicated by an arrow c while being in sliding contact with a guide / support rail 51 (not shown) as an insertion / removal guide portion described later (see FIG. 4 described later). See also b)).

  By the way, when an operation to take out the belt-type heat fixing unit 6 from the printer 1 after a paper jam has occurred or for parts replacement maintenance or the like, conventionally, the belt-type heat fixing unit 6 is suddenly removed from the printer 1 during the pulling-out operation. It was mentioned above that there was a unique problem of separating and dropping by its weight.

Hereinafter, a supplementary explanation thereof will be given.
FIGS. 5A to 5C are diagrams illustrating a procedure for taking out the fixing unit FU of the printer P according to the conventional example from the printer P.

  FIG. 5A shows a state in which the fixing unit FU is set on a guide base 63 provided horizontally with respect to the installation surface 52 of the printer P.

  Next, when it becomes necessary to remove the fixing unit FU from the mounting portion for maintenance work or the like, as shown in FIG. 5B, the handle 64 of the fixing unit FU is used by the operator 53 from the printer P. And pull out the fixing unit FU in the arrow X direction.

  Here, since the guide stand 63 is horizontal to the installation surface 52, the operator does not feel the weight of the fixing unit FU when pulling out the fixing unit FU, and therefore does not hold the central portion in the longitudinal direction of the fixing unit FU. Sometimes.

  As a result, the fixing unit FU is dropped in the direction of the arrow Y because the fixing unit FU is not supported at the central portion in the longitudinal direction of the fixing unit FU at the moment when the fixing unit FU is completely detached from the printer P.

  Therefore, in this example, a special device is provided as an image forming apparatus that can remove the fixing unit from the mounting portion without error. This will be described below.

  FIGS. 4A to 4C are diagrams illustrating a procedure for taking out the fixing unit of the printer 1 according to the first embodiment of the present invention from the main body apparatus. In FIGS. 4A to 4C, the same components as those shown in FIGS. 1 to 4 are given the same reference numerals as those shown in FIGS.

  In the printer 1 of the present invention, the guide and support rail 51 serving as a guide for supporting the belt-type fixing unit 6 is mounted at a lower position in the vertical direction than the mounting port (not shown) of the belt-type fixing unit 6 (see FIG. 4 (a)) and is provided inclined. That is, the mounting opening is arranged so as to have an inclination of 10 ° to 30 ° with respect to the horizontal plane of the printer 1.

  On the other hand, the belt type fixing unit 6 of the present invention has a cross section along the longitudinal direction of the fixing frame 6e similar to a parallelogram as shown in FIG. 4 (a). On the other hand, the fixing frame 6e. The fixing roller 6a, the heat roller 6b, the fixing belt 6c, and the pressing roller 6d disposed inside are respectively disposed with respect to the fixing frame 6e along the horizontal plane that is the installation surface 52 on which the printer 1 is installed. Has been.

  In order to take out the belt-type fixing unit 6 from the mounting portion of the printer 1, first, as shown in FIG. 4B, the handle 50 is grasped by one hand 53, and the belt-type fixing unit 6 is indicated by an arrow c. Pull out like so.

  Here, since the guide / support rail 51 for pulling out the belt-type fixing unit 6 is disposed with an inclination of 10 ° to 30 ° with respect to the printer 1, the belt-type fixing unit 6 is shown in FIG. As shown in FIG. 4, the operator feels the weight of the belt-type fixing unit 6 along with the pulling-out operation as shown in FIG. 53, the belt-type fixing unit 6 is supported. Unlike the prior art shown in FIG. 5B, the belt-type fixing unit 6 is not pulled out excessively. Falling can be prevented, and damage to the device and injury to the operator can be prevented.

In the embodiment of the present invention, the inclination angle of the guide / support rail 51 of 10 ° to 30 ° (inclination angle with respect to the horizontal plane of the printer 1) is set in consideration of a practical device space or the like, but is not limited thereto. It can be set to a steeper slope.
Although the belt-type fixing unit 6 has been described as the fixing unit according to the present invention, it goes without saying that the fixing unit can be applied to a fixing method without a fixing belt or an oven fixing method other than the roll-type fixing.

As mentioned above, although several embodiment of this invention was described, this invention is contained in the invention described in the claim, and its equality range. Hereinafter, the invention described in the scope of claims of the present application will be appended.
[Appendix 1]

A fixing unit that fixes the unfixed toner image on a recording medium to which an unfixed toner image is transferred and conveyed in an image transfer unit, and the fixing unit is detachable along the recording surface of the conveyed recording medium. A fixing unit mounting portion to be mounted,
The fixing unit mounting portion has an inclined insertion / removal guide portion that is provided from the mounting port of the fixing unit to a mounting completion position that is lower in the vertical direction than the mounting port and engages with the fixing unit. ,
An image forming apparatus.
[Appendix 2]

The fixing unit includes a unit main body, a plurality of fixing rollers including a heat roller, a fixing belt stretched between the plurality of fixing rollers, and a pressure contacting the one of the fixing rollers through the fixing belt. With rollers,
The image forming apparatus as set forth in appendix 1, wherein:
[Appendix 3]

The plurality of fixing rollers and the pressing roller are arranged along the recording surface of the recording medium on which the axial direction of each of the rollers is conveyed when the fixing unit is mounted on the fixing unit mounting portion, and Disposed in the unit body in a direction perpendicular to the transport direction,
The image forming apparatus according to appendix 2, wherein

  The present invention can be used in an image forming apparatus in which a fixing unit is attached to and detached from a mounting unit along the surface of a sheet to be conveyed.

1 Printer (device main unit)
DESCRIPTION OF SYMBOLS 2 Image formation part 3 Transfer belt unit 4 Toner supply part 5 Paper feed part 6 Belt type fixing unit 6a Fixing roller 6b Heat roller 6c Fixing belt 6d Pressing roller 6e Fixing frame 7 Conveying unit for double-sided printing 8 Transfer belt 8a Lower running surface 8b Back surface 9 (9y, 9m, 9c, 9k) Developing device 10 Photosensitive drum 11 Cleaner 12 Charging roller 13 Optical writing head 14 Developer 15 Developing roller 16 Housing 17 Bulkhead 15 Developing roller 18 First stirring and conveying screw 19 First 2 agitating and conveying screw 21 (221k, 21c, 21m, 21y) toner cartridge 22 driving roller 23 driven roller 24 secondary transfer roller 25 primary transfer roller 26 belt cleaner 27 waste toner collecting container 29 electrical component 31 (31a, 31b) For paper cassette 32 Take-out roller 33 Feed roller 34 Rolling roller 35 Standby transport roller pair 36 Unload roller pair 37 Discharge tray 37 Paper discharge roller pair 39 Return path 39a Return start path 39b Return intermediate path 39c Return end path 41 (41a, 41b, 41c, 41d, 41e) Return roller pair 42 Front door 43 Handle 44 Upper space 45 Handle 46 Operation panel 47 Handle 50 Handle 51 Guide and support rail 52 Installation surface 53 Worker's hand 63 Guide stand 64 Handle P Printer FU Fixing unit

Claims (3)

A fixing unit that fixes the unfixed toner image on a recording medium to which an unfixed toner image is transferred and conveyed in an image transfer unit, and the fixing unit is detachable along the recording surface of the conveyed recording medium. A fixing unit mounting portion to be mounted,
The fixing unit mounting portion includes an inclined insertion / removal guide portion that is provided from the mounting port of the fixing unit to a mounting completion position lower than the mounting port by engaging with the fixing unit.
An image forming apparatus. The fixing unit includes a unit main body, a plurality of fixing rollers including a heat roller, a fixing belt stretched between the plurality of fixing rollers, and a pressure contacting the one of the fixing rollers through the fixing belt. With rollers,
The image forming apparatus according to claim 1. The plurality of fixing rollers and the pressing roller are arranged along the recording surface of the recording medium on which the axial direction of each of the rollers is conveyed when the fixing unit is mounted on the fixing unit mounting portion, and Disposed in the unit body in a direction perpendicular to the transport direction,
The image forming apparatus according to claim 2.