JP2011215184A - Fixing device and image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make maintenance easy by easily performing cleaning, even when unfixed toner adheres to the entrance guide part of a unit case, in such a state that the unfixed toner is accumulated and grows like an icicle, in a fixing device.SOLUTION: The fixing device, including a fixing roller and the unit case 120 storing and supporting the fixing roller, includes an entrance guide 122 which guides the entrance of a recording medium into the fixing roller and is attachable to and detachable from the unit case 120. The entrance guide is projected to the side of the unit case 120 and includes locking parts 130a, 130b and 130c whose leading-end parts are bent and extended in a direction orthogonal to the entering direction of the recording medium. The unit case 120 includes locking holes to which the locking parts 130a, 130b and 130c can be locked.

Description

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

  Conventionally, in an image forming apparatus such as a copying machine, a printer, a facsimile, or a multi-function machine having a plurality of these functions, when the image forming apparatus is a full color type, yellow (Y), magenta (M) , Cyan (C), and black (BK), a plurality of photoconductors each having a drum corresponding to each color are prepared. A predetermined electrostatic latent image is formed on the peripheral surface of each photoconductor using a laser scanning unit, and a toner image of each color is formed on the peripheral surface of each photoconductor by the supplied toner of each color. Each is generated. The toner images of the respective colors generated on the peripheral surfaces of the respective photoconductors are sequentially superimposed and transferred onto a transfer belt composed of an endless belt that is driven to rotate, whereby a color image is synthesized on the transfer belt. Next, the color image synthesized on the transfer belt is transferred to a recording medium such as recording paper, and then subjected to a fixing process by being pressurized and heated by a fixing device (see Patent Document 1).

The fixing device fixes a toner image formed on a recording paper, and includes a fixing roller for applying heat to the recording paper and a pressure roller for pressing the recording paper against the fixing roller. . These fixing roller and pressure roller are provided in a unit case forming a unit of the fixing device. The unit case is detachably attached to the image forming apparatus main body, and is pulled out from the image forming apparatus main body for each unit case during maintenance inspection.
In the fixing device having the above-described configuration, when the recording paper on which the toner image is transferred is positioned between the fixing roller and the pressure roller, the recording paper is conveyed by rotation by the rollers, and is heated and pressurized. As a result, the toner is fixed.

JP 2006-201816 A

Incidentally, scattered toner adheres to the fixing device without being fixed on the recording paper. Therefore, it is necessary to periodically remove the fixing device from the main body of the image forming apparatus and perform maintenance on the fixing device.
However, since the fixing device has a complicated shape, there is a problem in that it is difficult to perform cleaning and lacks maintainability.
In particular, the entrance guide portion that hits the recording paper insertion port of the unit case adheres so that unfixed toner is stacked and grows in a wiggle shape, but because the entrance guide portion has a complicated shape, There was a drawback that it was very difficult to clean.

  The present invention has been made in view of the above-described problems. In the fixing device, even if unfixed toner adheres to the entry guide portion of the unit case so as to accumulate and grows in a wiggle shape, it can be easily cleaned. The purpose is to enable easy maintenance.

  The present invention adopts the following configuration as means for solving the above-described problems.

  According to a first aspect of the present invention, there is provided a fixing device including a fixing roller and a unit case that accommodates and supports the fixing roller, and guides entry of a recording medium into the fixing roller and is attached to and detached from the unit case. An entry guide that is enabled, and the entry guide includes a locking portion that protrudes toward the unit case side and has a locking portion that extends in a direction perpendicular to the entry direction of the recording medium while the tip portion is bent. The case employs a configuration in which the locking portion includes a locking hole that can be locked.

  According to a second aspect, in the first aspect, the entry guide includes a positioning member that has flexibility and includes a protruding portion that protrudes toward the unit case. In this position, a configuration is adopted in which a positioning hole is provided in which the protruding portion is locked.

  A third invention is an image forming apparatus comprising a developing device that develops a toner image on a recording medium and a fixing device that fixes the toner image onto the recording medium. A configuration in which the fixing device described in the first or second aspect is provided is adopted.

According to the present invention, since the entry guide of the unit case is detachably provided in the fixing device, unfixed toner adheres to the entry guide portion of the unit case so as to be stacked and grows in a wiggle shape. The entry guide can be removed for easy cleaning, and maintenance can be performed easily.
Further, since the locking guide and the protrusion are provided on the entry guide, the entry guide can be accurately attached to the unit case while positioning the entry guide.
Further, in the present invention, since the engaging portion extends in a direction orthogonal to the recording medium entering direction, the entry guide is inserted into the unit case from a direction orthogonal to the recording medium entering direction. Therefore, when the recording medium enters the entry guide, it is possible to prevent the entry guide from rattling due to the movement of the recording medium.

1 is a cross-sectional view illustrating a schematic configuration of a copying machine to which a fixing device according to an embodiment of the present invention is applied. FIG. 3 is a perspective view of a unit case of the fixing device according to the embodiment of the present invention. FIG. 2 is an exploded perspective view of a unit case of a fixing device according to an embodiment of the present invention. FIG. 3 is a perspective view of an entry guide incorporated in a unit case of the fixing device according to the embodiment of the present invention. FIG. 6 is a perspective view of an approach guide incorporated in a unit case of the fixing device according to the embodiment of the present invention when viewed from the back side.

  Hereinafter, an embodiment of an image forming apparatus including a fixing device according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size. In the following description, a copying machine will be described as an example of the image forming apparatus of the present invention.

  FIG. 1 is a cross-sectional view of a full-color copying machine P according to this embodiment. The copying machine P is based on an image reading unit 1 that reads an image of a document and read image data, as in a known copying machine. And a printing unit 2 that performs printing on recording paper (recording medium).

  The image reading unit 1 irradiates an image of a document with light and receives reflected light to read the image of the document as image data. The image reading unit 1 receives light returned from the light source device or the document that irradiates the document with light. It includes a light receiving sensor that receives light and converts it into image data.

  The printing unit 2 includes a belt unit 6, an image forming unit 7, a paper feed cassette 8, a paper feed tray 9, a secondary transfer unit 10, a fixing device 11, a paper discharge tray 12, and a conveyance path 13. And a waste toner collecting unit 14.

  The belt unit 6 transfers the toner image formed in the image forming unit 7 and conveys the transferred toner image. The belt unit 6 includes an intermediate transfer belt 61 to which the toner image is transferred from the image forming unit 7, and an intermediate transfer belt 61. The transfer belt 61 is provided with a driving roller 62 for ending and feeding endlessly, a driven roller 63, a tension roller 64, and a cleaning unit (not shown).

The intermediate transfer belt 61 is stretched around a driving roller 62, a driven roller 63, and a tension roller 64.
The drive roller 62 is connected to a drive unit having a drive source such as a motor, and rotates while applying a grip force to the intermediate transfer belt 61.
The driven roller 63 is driven to rotate following the rotational drive of the drive roller 62.
The tension roller 64 is a kind of driven roller that is driven to rotate by the rotational driving of the driving roller 62, and has a spring mechanism to apply tension to the intermediate transfer belt 61.

  A cleaning unit (not shown) is provided downstream of the drive roller 62 with respect to the intermediate transfer belt 61 and upstream of the first image forming unit 7 (yellow (Y)).

  The image forming unit 7 is provided corresponding to each color of yellow (Y), magenta (M), cyan (C), and black (BK), and forms a toner image of each color. These image forming units 7 are arranged in order from the upstream side to the downstream direction along the rotational driving direction of the intermediate transfer belt 61.

  Each image forming unit 7 includes a photoreceptor 71, a charger 72, a laser scanning unit 73, a developing device 74, a primary transfer roller 75, a cleaning device 76, a static elimination device (not shown), and the like.

  The photosensitive member 71 is formed in a cylindrical shape, and an electrostatic latent image and a toner image based on the electrostatic latent image are formed on the peripheral surface thereof. The charger 72 is disposed to face the photoconductor 71 and charges the peripheral surface of the photoconductor 71. The laser scanning unit 73 scans the circumferential surface of the charged photoreceptor 71 with laser light emitted based on the image data in the print format.

The developing device 74 develops a toner image based on the electrostatic latent image on the circumferential surface of the photoreceptor 71 by supplying toner to the circumferential surface of the photoreceptor 71.
The primary transfer roller 75 is disposed opposite to the photoreceptor 71 with the intermediate transfer belt 61 interposed therebetween, and primarily transfers the toner image developed on the photoreceptor 71 to the intermediate transfer belt 61. The cleaning device 76 removes toner remaining on the photoreceptor 71 after the primary transfer.

The paper feed cassette 8 can be pulled out with respect to the apparatus main body and accommodates recording paper (recording medium). The paper feed tray 9 is openable and closable with respect to the apparatus main body, and accommodates recording paper.
The secondary transfer unit 10 performs secondary transfer of the image formed on the intermediate transfer belt 61 to a storage medium. The secondary transfer unit 10 sandwiches the drive roller 62 that drives the intermediate transfer belt 61 and the intermediate transfer belt 61 therebetween. The drive roller 62 and the secondary transfer roller 10a are arranged to face each other.

The fixing device 11 fixes a toner image secondarily transferred onto a storage medium onto a recording paper, and is configured by arranging a fixing roller (heating roller) 100 and a pressure roller 110 in a unit case 120. ing. The fixing device 11 will be described in detail later with reference to the drawings.
The transport path 13 includes a pickup roller 13 a that transports the recording paper from the paper feed cassette 8, a paper feed roller 13 b that transports the storage medium, and a paper discharge roller 13 c that discharges the storage medium to the paper discharge tray 12.

  In the copying machine P having such a configuration, as described above, image data is acquired by the image reading unit 1, and color printing is performed on recording paper based on the image data by the printing unit 2.

  Hereinafter, the fixing device 11 will be described with reference to FIGS. As shown in FIG. 1, the fixing device 11 includes a fixing roller 100, a pressure roller 110, and a unit case 120.

The fixing roller (heating roller) 100 has a roller surface formed of an elastic material having heat resistance and a heat source disposed therein, and the length in the axial direction of the fixing roller (recording paper, recording paper) It is formed slightly larger than the width in the direction orthogonal to the conveyance direction of the medium. The fixing roller 100 is provided such that its axial direction is orthogonal to the recording paper conveyance direction.
The pressure roller 110 is configured to have the same axial length as the fixing roller 100, and the roller surface is formed of a heat-resistant elastic material, like the fixing roller 100.

The unit case 120 includes a housing 121 and an entry guide 122. Of these, the unit case 120 is made of a synthetic resin, and a space is provided in the interior thereof to sufficiently accommodate the fixing roller 100 and the pressure roller 110. It has been. That is, in the casing 121, both the axes of the fixing roller 100 and the pressure roller 110 are arranged in parallel, and the surfaces of both the rollers 100 and 110 are kept in contact with each other (see FIG. 1). .
This unit case 120 is detachably provided in the main body of the copying machine P. Therefore, the unit case 120 can be extracted from the main body during maintenance inspection.

  The approach guide 122 is formed of a long body, and the length thereof is determined to be slightly shorter than the length of the recording paper insertion port 123 having a rectangular shape provided in the unit case 120. And the cross-sectional shape of the transversal direction of the approach guide 122 is substantially L-shaped. One side of the L-shape is configured as a mounting piece 124, and the other side is configured as a guide piece 125.

  The attachment piece 124 is attached to an attachment portion 126 formed at an edge on the side where the fixing roller 100 is provided in the longitudinal direction of the insertion port 123 of the rectangular recording paper. This attachment method will be described in detail later.

  The guide piece 125 is provided so that the distal end side enters the housing 121 from the insertion port 123, and the distal end direction of the guide piece 125 is directed to a position where the surfaces of the fixing roller 100 and the pressure roller 110 are in contact with each other. Therefore, the guide piece 125 is attached to the insertion port 123 so as to form an inclined surface, and can guide the recording paper taken into the housing 121 through the insertion port 123.

Next, attachment of the attachment piece 124 to the attachment portion 126 will be described. First, in the longitudinal direction of the surface of the attachment portion 126, a plurality of (three in the illustrated example) locking holes 127a, 127b, and 127c are provided at predetermined intervals. And these latching holes 127a, 127b, and 127c are opened in the longitudinal direction side of the attaching part 126 among the side wall surfaces, and the claw parts 130a, 130b, and 130c can be latched.
In addition, a positioning hole 128 is provided in a part of the surface of the attachment portion 126 in the longitudinal direction (between the locking holes 127a and 127b), and another portion of the longitudinal surface (the locking hole). A screw hole 129 is provided between 127b and 127c.

Of the mounting piece 124, a surface in contact with the mounting portion 126 is provided with a plurality of L-shaped claw portions 130 a, 130 b, 130 c (locking) corresponding to the locking holes 127 a, 127 b, 127 c provided in the mounting portion 126. Part) is provided so as to protrude toward the attachment part 126, and the L-shaped tip direction is provided so as to face the opening provided in the side wall surface of the locking holes 127a, 127b, 127c.
In the present embodiment, the leading ends of the claw portions 130a, 130b, and 130c are bent and extend in a direction orthogonal to the recording paper entering direction. Therefore, the entry guide 120 can be easily attached and detached by sliding the entry guide 120 in a direction perpendicular to the recording sheet entry direction.

Further, the attachment piece 124 is provided with a positioning member 131 having a protruding portion that engages with a positioning hole 128 provided in the attachment portion 126. The positioning member 131 is flexible, and is configured such that the protrusion can be easily removed from the positioning hole 128 by bending when the entry guide 122 is attached or detached.
And the positioning hole 128 is provided in the position where the protrusion part of the positioning member 131 is latched in the normal position with respect to the unit case 120 with respect to the entry guide 122. For this reason, the approach guide 120 can be easily positioned by locking the protruding portion of the positioning member 131 in the positioning hole 128.

Further, the attachment piece 124 is provided with an opening 132 corresponding to the screw hole 129 provided in the attachment portion 126, and the screw 133 can be screwed into the screw hole 129 through the opening 132. It is configured as follows.
Here, the screw 133 fastens the entry guide 131 from the entry direction of the recording paper. For this reason, the entry guide 131 is firmly fixed with respect to the recording paper entry direction, and the entry guide 131 can be prevented from rattling due to the entry of the recording paper.

  In the copying machine P having the fixing device 11 having the above-described configuration, when the recording paper holding the toner image is positioned between the fixing roller 100 and the pressure roller 110, the recording paper is conveyed by the rotation of the rollers 100 and 110. In addition, the toner is fixed on the recording paper by applying heat and pressure.

  When the copier P is used for a long time, unfixed toner adheres to the entry guide 122 portion of the unit case 120 so as to accumulate and grows in a wiggle shape, so that cleaning is performed by maintenance personnel during periodic inspection. .

  At the time of cleaning by maintenance personnel, the unit case 120 is pulled out from the main body of the copying machine P. Next, the screw 133 of the extracted unit case 120 is removed, and the entry guide 122 is slid in the direction of arrow a in FIG. 1 and then pulled in the direction of arrow b to be removed from the unit case 120. After the removed entry guide 122 is cleaned, it is attached to the unit case 120 by operating in the reverse direction to the removal.

As described above, the entry guide 122 can be easily removed from the unit case 120 for cleaning, and the entry guide 122 after cleaning can be easily attached to the unit case 120, so that maintenance can be easily performed.
Further, the entry guide 122 extends in a direction perpendicular to the recording paper entering direction by bending the leading ends of the claw portions 130a, 130b, and 130c. It is inserted from the orthogonal direction. Therefore, when the recording paper enters the entry guide 122, it is possible to prevent the entry guide 122 from being shaken by the movement of the recording paper.

As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.
For example, in the above-described example, the case where the copying machine P is a full-color type has been described, but it may be a monochrome type.

  P: copier (image forming apparatus), 11: fixing device, 100: fixing roller, 110: pressure roller, 120: unit case, 121: housing, 122: entry guide, 123 ... ... Insertion slot 124 ... Mounting piece 125 ... Guide piece 126 ... Mounting portion 127a, 127b, 127c ... Locking hole 128 ... Positioning hole 129 ... Screw hole 130a, 130b, 130c ...... Claw part (locking part) 131 ... Positioning member 132 ... Opening hole 133 133 Screw

Claims (3)

A fixing device comprising a fixing roller and a unit case that accommodates and supports the fixing roller,
An entry guide that guides entry of the recording medium into the fixing roller and is detachable from the unit case;
The entry guide includes a locking portion that protrudes toward the unit case and has a leading end that is bent and extends in a direction perpendicular to the entry direction of the recording medium,
The fixing device according to claim 1, wherein the unit case includes a locking hole in which the locking portion can be locked. The entry guide includes a positioning member having a protrusion that protrudes toward the unit case while having flexibility.
2. The fixing device according to claim 1, wherein the unit case includes a positioning hole in which the protrusion is locked at a proper position of the entry guide. An image forming apparatus comprising: a developing device that develops a toner image on a recording medium; and a fixing device that fixes the toner image to the recording medium,
An image forming apparatus comprising the fixing device according to claim 1 or 2 as the fixing device.