JP2016224178A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that can more efficiently reduce a chemical emission to be discharged to the outside.SOLUTION: A compound machine 11 comprises: a paper setting part 19; an image forming unit 33; a fixing part 41a; a paper ejection tray 30; and a paper conveyance part 20. The paper conveyance part 20 includes paper conveyance paths 39a to 39d that are paths of a sheet P extending from the paper setting part 19 to the paper ejection tray 30. A toner contains titanium oxide. Fixing downstream-side paper conveyance paths 39c and 39d extending from the fixing part 41a to the paper ejection tray 30, of the paper conveyance paths 39a to 39d, are configured to irradiate the sheet P to be conveyed with at least any one of light and ultraviolet light.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus.

  In an image forming apparatus typified by a multifunction peripheral or the like, after an image of a document is read by an image reading unit, light is irradiated on the photoconductor provided in the image forming unit based on the read image, An electrostatic latent image is formed on the surface. Thereafter, a developer such as charged toner is supplied onto the formed electrostatic latent image to form a visible image, which is then transferred to paper, fixed by a fixing unit provided in the image forming apparatus, and discharged outside the apparatus. .

  Here, techniques relating to an image forming apparatus including a fixing unit are disclosed in Japanese Patent Application Laid-Open No. 2005-70264 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2005-55515 (Patent Document 2).

JP-A-2005-70264 JP-A-2005-55515

  Reduction in emissions of odors emitted from electronic devices such as image forming apparatuses and chemical emissions such as VOC (Volatile Organic Compounds) and UFP (Ultra Fine Particles) in recent years Is strongly demanded.

  In the image forming apparatus disclosed in Patent Document 1, an exhaust mechanism is provided so that air around the fixing portion where chemical emission is likely to occur is removed from the apparatus after removing chemical emission through an installed filter. . However, in such a configuration, the heat around the fixing unit is also discharged, and the thermal efficiency of the fixing unit is reduced. Furthermore, it is not preferable to employ such a mechanism due to noise problems in the exhaust mechanism.

  In addition, according to the image forming apparatus disclosed in Patent Document 2, a negative ion generator is installed in the vicinity of the paper discharge port to decompose or detoxify the generated chemical emission. However, the provision of such a negative ion generator becomes a large-scale apparatus configuration, which is to be avoided from the viewpoint of space saving and cost.

  An object of the present invention is to provide an image forming apparatus capable of reducing chemical emission released to the outside more efficiently.

  In one aspect of the present invention, the image forming apparatus forms an image on a sheet. The image forming apparatus includes a paper setting unit, an image creator, a fixing unit, a discharge tray, and a paper transport unit. The paper setting unit sets paper for forming an image. The image creator forms a visible image with toner and transfers it to paper. The fixing unit fixes the visible image transferred by the image creator to the sheet. The discharge tray discharges the paper fixed by the fixing unit to the outside of the image forming apparatus. The paper transport unit includes a paper transport path serving as a paper path from the paper set unit to the discharge tray. The paper transport unit transports the paper from the paper set unit to the discharge tray. The toner contains titanium oxide. Of the paper transport paths, the paper transported through the fixing downstream paper transport path from the fixing unit to the discharge tray is configured to be exposed to at least one of light and ultraviolet light.

  According to such an image forming apparatus, the toner contains titanium oxide, and among the paper conveyance paths, the paper conveyed on the fixing downstream paper conveyance path from the fixing unit to the discharge tray has light and ultraviolet rays. It is comprised so that at least any one may hit. Then, light or the like is applied to titanium oxide contained in the toner to generate negative ions, and chemical emissions generated in the image forming apparatus by the generated negative ions can be decomposed and removed. In this case, there is no need to adopt another new device mechanism. Therefore, such an image forming apparatus can reduce the chemical emission released to the outside more efficiently.

1 is a schematic diagram illustrating an appearance of a multifunction peripheral when an image forming apparatus according to an embodiment of the present invention is applied to the multifunction peripheral. FIG. 2 is a block diagram illustrating a configuration of the multifunction machine illustrated in FIG. 1. FIG. 2 is a schematic diagram illustrating a configuration of an image forming unit included in the multifunction peripheral illustrated in FIG. 1. FIG. 2 is a diagram illustrating a configuration of a fixing unit included in the multifunction peripheral illustrated in FIG. 1. It is the schematic which shows the structure of the heat roller and pressure roller which are contained in a fixing part. It is a figure which shows the structure of the fixing | fixed part contained in the multifunctional device which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below. FIG. 1 is a schematic diagram showing an external appearance of a multifunction peripheral when an image forming apparatus according to an embodiment of the present invention is applied to the multifunction peripheral. FIG. 2 is a block diagram showing the configuration of the multifunction machine when the image forming apparatus according to the embodiment of the present invention is applied to the multifunction machine.

  Referring to FIGS. 1 and 2, the multifunction machine 11 includes a control unit 12, an operation unit 13, an image reading unit 14, an image forming unit 15, a paper setting unit 19, a paper transport unit 20, and a discharge. A tray 30, a hard disk 16 as a storage unit, a facsimile communication unit 17, and a network interface unit 18 for connecting to a network 25 are provided.

  The control unit 12 controls the entire multifunction machine 11. The operation unit 13 includes a display screen 21 that displays information transmitted from the multifunction peripheral 11 side and user input contents. The operation unit 13 inputs image forming conditions such as the number of copies to be printed and gradation, and power on / off. The image reading unit 14 includes an ADF (Auto Document Feeder) 22 as a document transport device that transports a document set at the set position to the read position. The image reading unit 14 reads an image of a document set on the ADF 22 or a mounting table (not shown). The paper setting unit 19 includes a manual feed tray 28 for manually setting paper P as a recording medium and a paper feed cassette group 29 that can store a plurality of paper P having different sizes. The paper setting unit 19 sets the paper P to be supplied to the image forming unit 15. The paper transport unit 20 transports the paper P set in the paper setting unit 19 from the paper setting unit 19 to the discharge tray 30. The image forming unit 15 includes an image forming unit 33 that forms a visible image with toner and transfers the image onto the paper P, and a fixing unit 41 a that fixes the visible image with toner on the paper P. The image forming unit 15 forms an image on the conveyed paper P based on the image read by the image reading unit 14 and the image data transmitted via the network 25. The paper P on which an image is formed by the image forming unit 15 is discharged to the discharge tray 30. The hard disk 16 stores transmitted image data, input image forming conditions, and the like. The facsimile communication unit 17 is connected to the public line 24 and performs facsimile transmission and facsimile reception.

  The multi-function device 11 includes a DRAM (Dynamic Random Access Memory) for writing and reading image data, and the illustration and description thereof are omitted. In addition, arrows in FIG. 2 indicate the flow of data regarding control signals, control, and images. As shown in FIG. 1, in this embodiment, the sheet cassette group 29 includes three sheet cassettes 23a, 23b, and 23c.

  The multifunction device 11 operates as a copying machine by forming an image in the image forming unit 15 using the image data of the document read by the image reading unit 14. Further, the multifunction machine 11 forms an image in the image forming unit 15 and prints it on a sheet using the image data transmitted from the computers 26a, 26b, and 26c connected to the network 25 through the network interface unit 18. It operates as a printer. That is, the image forming unit 15 operates as a printing unit that prints the requested image. The MFP 11 uses the image data transmitted from the public line 24 through the facsimile communication unit 17 to form an image in the image forming unit 15 via the DRAM and is read by the image reading unit 14. The image data of the original is transmitted to the public line 24 through the facsimile communication unit 17, thereby operating as a facsimile apparatus. The multifunction machine 11 has a plurality of functions such as a copying function, a printer function, and a facsimile function regarding image processing. Further, each function has functions that can be set in detail.

  The image forming system 27 including the multifunction peripheral 11 according to an embodiment of the present invention includes the multifunction peripheral 11 having the above-described configuration and a plurality of computers 26a, 26b, and 26c connected to the multifunction peripheral 11 via the network 25. Prepare. In this embodiment, three computers 26a to 26c are shown. Each of the computers 26 a to 26 c can make a print request to the multi-function peripheral 11 via the network 25 to perform printing. The multi-function device 11 and the computers 26a to 26c may be connected by wire using a LAN (Local Area Network) cable or the like, or may be connected wirelessly. A configuration in which a machine or a server is connected may be used.

  Next, the configuration of the image forming unit 15 provided in the multifunction machine 11 will be described. FIG. 3 is a diagram showing a configuration of the image forming unit 15 included in the multifunction machine 11 according to the embodiment of the present invention. FIG. 4 is a diagram illustrating a configuration of the fixing unit 41 a included in the image forming unit 15. FIG. 5 is a schematic diagram illustrating the configuration of the heat roller 42 and the pressure roller 43 included in the fixing unit 41a. From the viewpoint of easy understanding, in FIG. 5, the shape of the heat roller 42 is exaggerated and the paper P is also shown. Further, from the viewpoint of easy understanding, the heat roller 42 and the pressure roller 43 are illustrated separately in FIG. In FIG. 3, the fixing unit 41a is indicated by a two-dot chain line.

  1 to 5, the image forming unit 15 includes photoreceptors 31a, 31b, 31c, and 31d, and includes four image forming units 32a corresponding to four colors of yellow, magenta, cyan, and black. An image forming unit 33 including 32b, 32c, and 32d; an LSU (Laser Scanner Unit) 34 as an exposure unit that exposes the four image forming units 32a to 32d based on the image read by the image reading unit 14; The transfer belt 35 serving as an intermediate transfer member that is temporarily transferred before transferring the visible image formed by the image forming units 32a to 32d onto the paper, and the toner remaining on the transfer belt 35 are removed by a blade or the like. A transfer belt cleaning unit 37. About LSU34, it has shown roughly with the dashed-dotted line. The transfer belt cleaning unit 37 is also schematically shown. The image forming unit 15 is a so-called four-tandem development method.

  The multifunction machine 11 can perform monochrome printing using only the black image forming unit 32d. The multifunction machine 11 can perform color printing using at least one of a yellow image forming unit 32a, a magenta image forming unit 32b, and a cyan image forming unit 32c.

The transfer belt 35 is endless, and is a visible image formed by image forming units 32a to 32d of four colors of yellow, magenta, cyan, and black while being rotated in one direction by a driving roller 36a and a driven roller 36b. Is transcribed. Rotational direction of the transfer belt 35 is indicated by an arrow D ₁ of the in Figure 3. Of the image forming units 32a to 32d, the yellow image forming unit 32a is disposed on the most upstream side, and the black image forming unit 32d is disposed on the most downstream side in the rotation direction of the transfer belt 35. . The transfer belt cleaning unit 37 is disposed upstream of the yellow image forming unit 32a.

The toner composed of a binder resin, a colorant and the like contains titanium oxide as an external additive for performing a surface treatment or the like. The content of titanium oxide is, for example, 0.5% by mass to 5.0% by mass of the whole toner. Further, the average particle diameter of titanium oxide contained in the toner is in the range of 20 nm (nanometer) to 500 nm, for example. As a specific embodiment, the average particle diameter of titanium oxide contained in the toner is 20 nm, and the content of titanium oxide contained in the toner is 0.5% by mass to 1.0% by mass. . As the titanium oxide used, for example, TiO ₂ and the like.

  The paper transport unit 20 is disposed on the upstream side of the paper transport path 9a, 39b, 39c, 39d and the fixing unit 41a in the transport direction of the paper P as the paper P path from the paper set unit 19 to the discharge tray 30. A fixing upstream transport roller pair 40a and a fixing downstream transport roller pair 40b disposed downstream of the fixing unit 41a in the transport direction of the paper P are included. The fixing upstream transport roller pair 40a includes a transport roller pair 38a disposed from the upstream side. The fixing downstream conveyance roller pair 40b includes a fixing discharge roller pair 38b that discharges from the fixing unit 41a, and a main body discharge roller pair 38c that discharges from the main body side, that is, the multifunction machine 11 side. The fixing discharge roller pair 38b includes a first fixing discharge roller 45a positioned on the side of the sheet P on which the image is formed and a second fixing discharge positioned on the side of the sheet P where the image is not formed. It is comprised from the roller 45b. The pair of main body discharge rollers 38c is a first main body discharge roller 46a located on the surface side of the paper P on which the image is formed and a second main body discharge roller located on the side of the paper P where the image is not formed. And a roller 46b. Among the sheet conveyance paths 39a to 39d, the sheet conveyance paths 39a and 39b positioned on the upstream side of the fixing unit 41a become the fixing upstream sheet conveyance path and the sheet conveyance path positioned on the downstream side of the fixing unit 41a of the fixing unit 41b. Reference numerals 39c and 39d are fixing downstream paper transport paths. Although not shown, the paper transport unit 20 includes a paper transport path and a pair of transport rollers provided at other locations.

The paper P is transported through the paper transport paths 39a to 39d by the transport roller pair 38a, the fixing discharge roller pair 38b, and the main body discharge roller pair 38c, and is discharged onto the discharge tray 30. During conveyance, the visible image primarily fired onto the transfer belt 35 is secondarily transferred by the imager 33 during conveyance. Conveying direction of the sheet P from the fixing portion 41a down to the discharge tray 30 is shown in the direction of arrow D ₂ in FIG.

  The multifunction machine 11 includes a fixing unit 41 a that fixes the visible image transferred by the image creator 33 to the paper P. The fixing unit 41 a includes a hollow rotatable heat roller 42, a solid rotatable pressure roller 43, a first heater 44 a that mainly heats a central region of the heat roller 42, and both ends of the heat roller 42. And a second heater 44b that mainly heats the region. The first and second heaters 44 a and 44 b are respectively arranged in parallel to the inner side of the heat roller 42.

The heat roller 42 has a substantially cylindrical shape and is composed of a metal base tube. The diameter of the central area of the heat roller 42 is configured to be slightly smaller than the diameter of the both end areas of the heat roller 42 (see FIG. 5). That is, the heat roller 42 has a drum shape. The diameter of both end portions of the heat roller 42 and the length _{L 1,} when the diameter of the central portion of the heat roller 42 and the length _{L 2,} and is configured L ₁ -L 2 = 0.1mm and so as. By configuring in this way, heat can be uniformly applied to the paper P conveyed over the rotation axis direction which is the longitudinal direction of the heat roller 42 by the thermal expansion of the heat roller 42.

  The pressure roller 43 is composed of a rubber-like columnar member having elasticity. The pressure roller 43 is configured such that the diameters of both end regions and the central region are the same. The heat roller 42 and the pressure roller 43 are in contact with each other. Specifically, the heat roller 42 and the pressure roller 43 are provided so that the surface of the heat roller 42 and the surface of the pressure roller 43 are in contact with each other with a certain nip amount. Since the heat roller 42 and the pressure roller 43 are in contact, the heat of the heat roller 52 is transmitted to the pressure roller 43 to some extent. That is, the heat roller 42 and the pressure roller 43 have almost the same temperature distribution.

  The pressure roller 43 rotates in one direction. The heat roller 42 rotates in the opposite direction to the pressure roller 43. The paper P is conveyed from the upstream side to the downstream side by the rotation of the heat roller 42 and the pressure roller 53. That is, the heat roller 42 and the pressure roller 43 also have a paper transport function for transporting the paper P. The fixing unit 41 a fixes the visible image with the toner formed on the paper P by heating and pressing with the heat roller 42 and the pressure roller 43 during the conveyance.

  Further, the image forming unit 15 includes a cover 47a that covers the fixing downstream side conveyance roller pair 40b. The cover 47a is made of a resin member, for example, and constitutes a part of the housing of the multifunction machine 11. The cover 47a is provided so as to expose the top from the position where the fixing unit 41a is provided in the vertical direction. In this case, the main body discharge roller pair 38c is configured to be exposed to the outside.

  Here, among the paper transport paths 39a to 39d, the paper P transporting the paper transport path 39d on the downstream side of the fixing from the fixing unit 41a to the discharge tray 30 is exposed to at least one of light and ultraviolet light. It is configured. Specifically, the guide member 48a that constitutes the sheet conveyance path 39d and is located on the surface side on which the image of the sheet P is formed is formed of a transparent member that transmits at least one of light and ultraviolet rays. ing. Specifically, the guide member 48a is made of a resin or glass member.

In this case, the cover 47a is provided such that the top is exposed from the position where the fixing portion 41a is provided. Thus, for example, light coming through a direction indicated by an arrow D ₃ in FIG. Then, light strikes the surface on which the image is formed in the paper P transported through the paper transport path 39d.

  According to such a multi-function device 11, the toner contains titanium oxide, and among the paper transport paths 39 a to 39 d, the paper transported through the fixing downstream paper transport path 39 d from the fixing unit 41 a to the discharge tray 30. Is configured to be exposed to at least one of light and ultraviolet rays. Then, light or the like is applied to titanium oxide contained in the toner to generate negative ions, and chemical emissions generated in the multifunction machine 11 by the generated negative ions can be decomposed and removed. In this case, there is no need to adopt another new device mechanism. Therefore, such a multi-function machine 11 can reduce the chemical emission released to the outside more efficiently.

  In this case, since the content of titanium oxide is within the above-described range, it is possible to more efficiently reduce the chemical emission released to the outside. Further, since the average particle diameter of titanium oxide contained in the toner is also within the above-described range, it is possible to reduce the chemical emission released to the outside more efficiently.

  In this case, since the sheet P has a configuration in which at least one of light and ultraviolet rays hits the side on which an image is formed, the chemical emission generated in the multifunction machine 11 can be more efficiently decomposed and removed. Can be achieved.

  In the above embodiment, the guide member 48a is made of a transparent member. However, the present invention is not limited to this, and a part of the guide member 48a is opened, for example, a notch is provided, The light or the like may strike the paper P that is transported through the paper transport path 39d.

  In the above-described embodiment, a light source that irradiates at least one of light and ultraviolet rays on the paper P transported through the paper transport path 39d may be provided inside the multifunction peripheral 11. FIG. 6 is a view showing the vicinity of the fixing unit 41b in this case. In FIG. 6, the same members as those in the embodiment shown in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted.

Referring to FIG. 6, the sheet transport unit 20 provided in the multifunction machine 11 according to another embodiment of the present invention includes a fixing discharge roller pair 38b and a main body discharge roller pair 38c. Further, a light source 49 for irradiating the sheet P transported through the sheet transport path 39d with ultraviolet rays is provided on the inner side of the cover 47a. Irradiation direction of the ultraviolet rays is indicated by arrow D ₄ in FIG.

  With this configuration, it is possible to efficiently decompose and remove chemical emission by irradiating ultraviolet rays from the light source 49.

  In this case, with respect to the timing of irradiating the ultraviolet rays from the light source 49, the ultraviolet rays may be constantly applied, or the light source 49 may be turned on and irradiated with the ultraviolet rays during image formation.

  In the above embodiment, the sheet P is configured such that at least one of light and ultraviolet rays hits the surface of the sheet P on which an image is formed. Among these, it may be configured such that at least one of light and ultraviolet rays hits a surface side on which an image is not formed. By doing so, chemical emission can be decomposed and removed by ultraviolet rays or the like transmitted through the paper P.

  In the above embodiment, of the first and second fixing discharge rollers 45a and 45b and the first and second main body discharge rollers 46a and 46b, which are transfer rollers constituting the fixing downstream-side transfer roller pair 40b. It is good also as a structure which at least any one of irradiates at least any one of light and an ultraviolet-ray. Specifically, for example, the first main body discharge roller 46a is made of a transparent member, and a light source is provided inside. The light source may emit light and the paper P may be irradiated with ultraviolet rays or the like.

  In the above-described embodiment, the four-tandem development method is employed. However, the present invention is not limited to this, and another method, for example, a monochrome development method may be employed.

  It should be understood that the embodiments and examples disclosed herein are illustrative in all respects and are not restrictive in any respect. The scope of the present invention is defined by the scope of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the scope of the claims.

  The image forming apparatus according to the present invention is particularly effectively used when more efficient reduction of chemical emission discharged to the outside is required.

  DESCRIPTION OF SYMBOLS 11 MFP, 12 Control part, 13 Operation part, 14 Image reading part, 15 Image formation part, 16 Hard disk, 17 Facsimile communication part, 18 Network interface part, 19 Paper setting part, 20 Paper conveyance part, 21 Display screen, 22 ADF, 23a, 23b, 23c Paper cassette, 24 Public line, 25 Network, 26a, 26b, 26c Computer, 27 Image forming system, 28 Manual feed tray, 29 Paper feed cassette group, 30 Discharge tray, 31a, 31b, 31c, 31d Photoconductor, 32a, 32b, 32c, 32d Image forming unit, 33 Imager, 34 LSU, 35 Transfer belt, 36a Drive roller, 36b Driven roller, 37 Transfer belt cleaning unit, 38a Transport roller pair, 38b Fixing discharge Roller pair, 38c main body discharge roller pair, 45a, 45b fixing discharge roller, 46a, 46b main body discharge roller, 39a, 39b, 39c, 39d paper transport path, 40a fixing upstream transport roller pair, 40b fixing downstream transport roller pair, 41a, 41b fixing unit, 42 heat roller, 43 pressure roller, 44a, 44b heater, 47a cover, 48a guide member, 49 light source.

Claims (8)

An image forming apparatus for forming an image on paper,
A paper setting unit for setting the paper on which an image is to be formed;
An imager that forms a visible image with toner and transfers it to the paper;
A fixing unit for fixing the visible image transferred by the image generator to the paper;
A discharge tray for discharging the paper fixed by the fixing unit to the outside of the image forming apparatus;
Including a paper transport path serving as a path of the paper from the paper set section to the discharge tray, and a paper transport section for transporting the paper from the paper set section to the discharge tray,
The toner contains titanium oxide,
An image forming apparatus configured so that at least one of light and ultraviolet rays hits a sheet conveyed on a fixing downstream sheet conveying path from the fixing unit to the discharge tray in the sheet conveying path. . The fixing downstream paper transport path is constituted by a guide member,
The image forming apparatus according to claim 1, wherein at least a part of the guide member includes a transmission portion that transmits at least one of light and ultraviolet light. The image forming apparatus according to claim 2, wherein the transmission portion is made of a resin or glass member. 4. The image forming apparatus according to claim 1, wherein a surface of the sheet on which an image is formed is a surface on which at least one of the light and the ultraviolet light strikes. 5. 4. The image forming apparatus according to claim 1, further comprising an irradiation unit configured to irradiate at least one of the light and the ultraviolet light on the paper transported on the fixing downstream paper transport path. 5. 6. The image forming apparatus according to claim 1, wherein a content of the titanium oxide contained in the toner is 0.5% by mass to 5.0% by mass of the whole of the toner. The image forming apparatus according to claim 1, wherein an average particle diameter of the titanium oxide contained in the toner is in a range of 20 nm (nanometer) to 500 nm. The average particle diameter of the titanium oxide contained in the toner is 20 nm, and the content of the titanium oxide contained in the toner is 0.5% by mass to 1.0% by mass. The image forming apparatus according to claim 1.

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