JP3950635B2 - Static eliminator, image forming apparatus, and original reading apparatus in sheet conveying apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a paper transport device that transports recording paper, originals, and the like to a predetermined position in a facsimile machine, a copier, a printer, and the like, and eliminates static electricity generated in the paper transport unit as the paper is transported. The present invention relates to an apparatus, an image forming apparatus on which the charge eliminating apparatus is mounted, and a document reading apparatus.
[0002]
[Prior art]
2. Description of the Related Art In a paper conveyance device mounted on a copying machine or a facsimile machine, paper conveyance is performed by applying a rotational force of a conveyance roller installed in a paper conveyance path to the paper. At that time, frictional charging occurs due to friction between the sheet and the conveyance guide or between the sheet and the roller, and static electricity is generated. This static electricity has an adverse effect on each part such as a cause of deterioration of a formed image in an apparatus main body on which the paper transport device is mounted, for example, an electrophotographic image forming apparatus, or a cause of radio wave interference.
[0003]
Therefore, normally, all the metals in the vicinity of the conveying surface in the sheet passing path of the sheet conveying apparatus are grounded. For example, the roller holding shaft that is formed of a metal such as stainless steel and holds the conveying rollers is also grounded. Has been taken.
[0004]
[Problems to be solved by the invention]
However, in the paper transport device, since the transport roller is always rotated during transport, conventionally, the rotation is stabilized by using oil-impregnated metal for the bearing that receives the roller holding shaft, but depending on the device, the cost may be reduced. Some have a plastic housing as a bearing. Usually, since a plastic casing having no electrical conductivity is used, if the plastic casing itself is configured as a bearing, it cannot be grounded. Therefore, in this configuration, the grounding is reliably performed by, for example, bringing the grounding metal member into direct contact with the roller holding shaft. Since the metal member for earthing and the roller holding shaft are in contact with each other, the contact resistance value is as low as 1Ω or less, and the charge eliminating effect is great.
[0005]
However, since the metal member for grounding and the roller holding shaft are in contact with each other, when the roller holding shaft rotates, there is a problem that an abnormal noise such as a key is easily generated between the two. For this reason, this is dealt with by applying a conductive lubricant such as conductive grease to the contact portion between the earth metal and the roller holding shaft.
[0006]
As the conductive lubricant, conductive grease is usually used. However, since this conductive grease generally contains carbon powder in grease, the resistance value of the conductive grease itself is large. If the contact is made through the conductive grease, the resistance value becomes unstable compared to the metal contact state. In addition, the performance of the conductive grease cannot be demonstrated over a long period due to variations in the application state of the conductive grease, or functional deterioration due to environmental changes. For example, the conductive grease is removed at the metal contact portion and substantially The ground metal and the roller holding shaft may be in contact with each other to generate noise. In other words, there is no guarantee that a stable static elimination effect can be obtained or abnormal noise is generated just by applying conductive grease, and there is a problem in reliability.
[0007]
As another grounding means, there is a method using a conductive plastic member instead of the metal contact as described above, but a stable grounding effect cannot be obtained because the conductive plastic member itself has a high resistance value, and the conductive plastic member is cost-effective. There is a difficulty that it is expensive.
[0008]
In view of the above-described conventional problems, an object of the present invention is to provide a static eliminator in a paper conveyance device in which static electricity is grounded in a paper conveyance unit without generating abnormal noise with a simple configuration, and an image equipped with the static eliminator. An object of the present invention is to provide a forming apparatus and a document reading apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the end of the rotary shaft holding the paper transport roller is rotatably supported by a support member, and is generated by frictional charging between the roller and the paper. in the static eliminator of a sheet conveying device for grounding the static electricity, the rotating shaft is formed of a conductive metal, is contacted with ground conductive member through the dividing conductive fabric on a part of circumferential surface of the metallic rotary shaft Then, a conductive lubricant is applied to the surface of the metal rotating shaft of the static elimination cloth, and the ground conductive member is made of the metal on the surface of the ground conductive member on the surface where the static elimination cloth is attached. In this structure, there is provided an exposed facing surface that does not contact the peripheral surface of the rotating shaft . With this configuration, the grounding conductive member is not in direct contact with the metal rotating shaft that holds the paper transport roller. Through the cloth To touch, it is possible to suppress the generation of abnormal noise due to friction during rotation of the rotating shaft can take a reliable ground to stabilize by the contact also interposed neutralizing cloth. In addition, even if a static eliminating cloth is installed, the lubricant can be smoothly rotated by the lubricating action of the lubricant without hindering the operation of the rotating shaft. In addition, a discharge gap corresponding to the thickness of the neutralizing cloth is formed between the rotating shaft and the grounding conductive member, and static electricity can be discharged to the exposed opposing surface of the grounding conductive member. Is called.
[0010]
According to a second aspect of the present invention, in the static eliminator of the paper conveying device according to the first aspect, the neutralizing cloth is brought into contact with each of the rotating shafts holding a plurality of paper conveying rollers, and each of the neutralizing cloths is connected to a common grounding conductor. It is characterized in that it is pressed against a metal rotating shaft by a member, and by this configuration, a neutralizing cloth that contacts a plurality of rotating shafts is brought into contact with a single grounding conductive member and pressed against each rotating shaft, The grounding for the plurality of rotating shafts is performed by a simplified configuration.
[0011]
According to a third aspect of the present invention, in the static eliminator of the paper conveying device according to the first aspect, a common static eliminating cloth is brought into contact with each of the rotating shafts holding a plurality of paper conveying rollers, and the static eliminating cloth is connected to a common ground. This structure is characterized in that the metal rotating shaft is pressed by a conductive member for earthing. With this configuration, the neutralizing cloth is grounded for each of a plurality of rotating shafts by a single neutralizing cloth and a single grounding conductive member. Since it is pressed by the conductive member, the grounding for the plurality of rotating shafts is performed with a more simplified configuration.
[0016]
According to a fourth aspect of the present invention, there is provided a sheet conveying apparatus for grounding static electricity generated by frictional charging between the roller and the sheet, wherein an end of a rotating shaft holding a sheet conveying roller is rotatably supported by a support member. in the static eliminator, contacting the ground conductive member through the dividing conductive fabric on a part of the sheet conveyance surface outside of the circumferential surface of the roller, the surface of the attachment surface side of the neutralizing cloth in the ground conductive member in, The grounding conductive member is provided with an exposed facing surface that does not contact the peripheral surface on the roller side . With this configuration, the grounding conductive member can be used as a paper transporting roller without contacting the rotating shaft. On the other hand, it can be reliably grounded to remove static electricity from the roller by touching it through the antistatic cloth, and it is possible to suppress the generation of abnormal noise due to friction during rotation of the rotating shaft as in the past, Duck, dirt of paper by neutralizing fabric can be cleaned easily roller attachment. Further, a discharge gap corresponding to the thickness of the static eliminating cloth is formed between the roller and the grounding conductive member, and static electricity can be discharged to the exposed opposing surface of the grounding conductive member, so that static electricity is effectively removed. .
[0017]
According to a fifth aspect of the present invention, in the static eliminator in the paper conveying device according to the fourth aspect , the neutralizing cloth is brought into contact with a plurality of paper conveying rollers, and each neutralizing cloth is brought to the roller side by a common grounding conductive member. With this configuration, the grounding for the plurality of rollers is achieved by bringing the static-removing cloth that contacts the plurality of paper transport rollers into contact with a single grounding conductive member and pressing each roller. This is done with a simplified configuration.
[0018]
According to a sixth aspect of the present invention, in the static eliminator in the paper conveying device according to the fourth aspect , a common static eliminating cloth is brought into contact with each of a plurality of paper conveying rollers, and the static eliminating cloth is rolled by a common grounding conductive member. With this configuration, the neutralizing cloth and the single grounding conductive member respectively press the grounding cloth against the plurality of paper transport rollers by the grounding conductive member. For this reason, the grounding for the plurality of rollers is performed with a more simplified configuration.
[0023]
The invention according to claim 7 is the static eliminator in the paper conveying apparatus according to any one of claims 1 to 6, wherein a cloth-like material in which polyethylene terephthalate fiber, nickel, and copper are woven is used as the static eliminator. With this configuration, it is possible to provide a static eliminator having excellent wear resistance and durability and reliability.
[0024]
The invention according to claim 8 is a paper feed roller for feeding paper from a paper feed cassette loaded with paper, a transport roller for carrying paper fed from the paper feed roller, and paper for the image forming unit. In the image forming apparatus in which a registration roller that feeds the paper at a timing and a paper discharge roller that discharges the paper to the outside of the apparatus are installed in the paper transport path, the paper feed roller, the transport roller, the registration roller, and the paper discharge roller characterized in that set up a static elimination device in the sheet conveying apparatus according to claim 1-7, wherein at least one of installation location with, this configuration roller of the various paper transporting for conveying the recording sheet recording sheet It is possible to prevent adverse effects of static electricity generated by frictional charging on the apparatus constituent members.
[0025]
According to the ninth aspect of the present invention, a feed roller that separates and feeds documents one by one from the document setting table and a document transport roller that transports the document fed from the feed roller to the reading sensor are installed in the document transport path. in the document reading apparatus, the features that it has established a neutralization apparatus in the sheet conveying apparatus according to claim 1-7, wherein at least one of the installation location of the feed roller and the document conveying roller, this configuration the original It is possible to prevent adverse effects of static electricity generated by frictional charging between the various paper transport rollers and the original to be conveyed on the apparatus constituent members.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the drawings.
[0027]
FIG. 1 is an overall configuration diagram of a facsimile machine for explaining an embodiment of the present invention. Reference numeral 1 denotes an original reading unit installed on the upper part of the apparatus main body 2, and reference numeral 3 denotes a central part of the apparatus main body 2. Electrophotographic image forming apparatus units 4 and 5 are paper feed cassettes on which sheets P are stacked and stored.
[0028]
In the document reading unit 1, reference numeral 6 denotes a document setting unit, 7 includes a feed roller 7a and a friction pad 7b, and a document separation / feed unit that separates and feeds documents one by one, and 8 optically reads document information. A reading sensor 9 is a white roller for pressing the document against the reading sensor 8, and 10 and 11 are installed on the upstream side and the downstream side of the reading sensor 8 in the document conveying direction, respectively. A document transport roller 12 for transporting the document at a predetermined speed and a document discharge tray 12 for receiving a document discharged to the outside by the downstream document transport roller 11. The document discharge tray from the document set unit 6 through the reading sensor 8. A paper transport roller for transporting a document is installed in a document transport path including 12 guide plates 13 and the like. Note that the paper transport roller means a roller having a function of transporting paper, and in this case, includes the feed roller 7a and the document transport rollers 10 and 11.
[0029]
In the image forming apparatus unit 3, reference numeral 15 denotes a photosensitive unit including a photosensitive member 16 as a main constituent member including a toner cartridge, 17 denotes a transfer charger disposed opposite to the photosensitive member 16, and 18 denotes a photosensitive member 16 and a transfer charger 17. A registration roller that feeds the paper P in a timely manner at the nip portion of the paper, 19 is a fixing portion that performs a fixing process of the toner image on the paper P after the transfer, and 20 is a paper discharge of the paper P that has been subjected to the fixing processing. A paper discharge roller 21 is a paper discharge tray that receives the paper P discharged to the outside by the paper discharge roller 20. Reference numeral 22 denotes an optical system that emits a laser beam L that exposes the surface of the photoconductor 16 to form a latent image on the surface of the photoconductor 16 based on image data.
[0030]
In the paper feed cassettes 4 and 5, 25 and 26 are paper feed rollers for feeding paper P from the paper feed cassettes 4 and 5, and 27 and 28 are paper rollers for feeding paper P fed by the paper feed rollers 25 and 26. A transport roller 29 for transporting in 18 directions is a guide plate that is installed in the transport path of the paper P and guides the paper P. A paper transporting roller for transporting the recording paper is installed in a paper transporting path from the paper feed cassettes 4 and 5 to the paper discharge tray 21 through the image forming apparatus unit 3. The paper transport roller means a roller having a function of transporting paper. Here, the paper feed rollers 25 and 26, the transport rollers 27 and 28, the registration roller 18 and the paper discharge roller 20 are used. It is.
[0031]
FIG. 2 is a perspective view showing a main part of a conveying roller 28 portion which is one of the paper conveying rollers, and 31 shows only one side in the figure, but a pair of plastic made opposed to each other. Both end portions of a rotating shaft 33 made of metal such as stainless steel are rotatably supported by bearings 32 provided on both support frames 31. A plurality of paper transport rollers made of rubber, plastic, or the like, for example, a transport roller 28 are fixed in a paper passing area of the rotary shaft 33, and the transport roller together with the rotary shaft 33 that rotates by receiving the rotational driving force of a drive source (not shown). As the paper 28 rotates, the paper P is conveyed in a predetermined direction.
[0032]
As shown also in FIG. 3, one end of a metal grounding conductive plate 34 made of a stainless steel plate having elasticity and the like is elastically contacted with the peripheral surface of the rotating shaft 33 via a static eliminating cloth 35. . The other end of the grounding conductive plate 34 is held and grounded by a suitable fixing method such as screwing to a member in the conductive device.
[0033]
As described above, in the present embodiment, since the neutralizing cloth 35 is interposed in a portion where the rotating shaft 33 and the grounding conductive plate 34 are in contact with each other in the related art, abnormal noise as in the conventional case is present in the contact portion. Will not occur. Further, the contact portion between the rotating shaft 33 and the grounding conductive plate 34 is stabilized by the interposition of the neutralizing cloth 35, and the ground circuit is reliably formed from the rotating shaft 33. Static electricity generated by frictional charging with the roller 28 can be effectively grounded via the rotary shaft 33 and the grounding conductive plate 34.
[0034]
Examples of the material of the neutralizing cloth 35 include a fabric woven with chemical fiber (PET: polyethylene terephthalate) and Ni, Cu. The neutralizing cloth made of this PET fiber has a resistance value one digit higher than that of the conventional metal-metal contact. Although it is about 10Ω, the static elimination effect is stable and sufficient as a function, and is extremely excellent in wear resistance, so there is no problem in durability even if it makes contact with the rotating part. In addition, it has strong characteristics against changes in environmental conditions. Moreover, since the neutralizing cloth including the neutralizing cloth made of PET fiber is generally low in price and very simple in configuration, it replaces the conductive lubricant applied to the conventional intermetallic contact portion. As a matter of fact, the practical effect is great.
[0035]
As shown in FIG. 4, if it is structurally possible and there is an installation space, it is possible to install the grounding conductive plate 34 so that the neutralizing cloth 35 is in elastic contact with the end surface of the rotating shaft 33. It is done.
[0036]
Further, as shown in FIG. 5, the grounding conductive plate 34 is elastically exposed to a part of the paper transporting roller such as the transporting roller 28 (on the side opposite to the transporting surface of the paper P). It is also possible to install it so that it touches. In this case, the neutralizing cloth 35 has a cleaning function of removing dust and the like attached to the roller in addition to a function of reliably grounding static electricity charged to the roller and a function of preventing the generation of abnormal noise. If structurally possible and there is an installation space, it is also possible to install the grounding conductive plate 34 at a position where the neutralizing cloth 35 is elastically contacted with the end surface of the roller, as in the configuration shown in FIG. It is done.
[0037]
Further, as shown in FIG. 6, by providing an exposed facing surface 34a in which the grounding conductive plate 34 does not contact the peripheral surface on the rotating shaft 33 side on the surface of the grounding conductive plate 34 on which the neutralizing cloth 35 is provided, A discharge gap h having a thickness of the neutralizing cloth 35 (usually about 50 to 100 mμ) is formed between the rotating shaft 33 and the grounding conductive plate 34 on the exposed opposing surface 34a, and the static electricity charged on the rotating shaft 33 is electrically connected to the grounding conductor. Since it becomes possible to discharge with respect to the exposed opposing surface 34a of the board 34, removal of static electricity comes to be performed more effectively. This configuration can also be similarly adopted in a configuration in which the neutralizing cloth 35 is brought into contact with the peripheral surface of the paper transport roller.
[0038]
In addition, as a structure of the static elimination member which consists of the electrically conductive board 34 for earth | ground and the static elimination cloth 35, as shown in FIG. 7, in the state which made the static elimination cloth 35 each contact independently with respect to the some rotating shaft 33, Each of the antistatic cloths 35 is pressed in the direction of the rotary shaft 33 by the grounding conductive plate 34 formed of a single leaf spring, or, as shown in FIG. It is conceivable that the cloths 35 are brought into contact with each other, and the static eliminating cloth 35 is pressed in the direction of the rotary shaft 33 at each contact portion by the grounding conductive plate 34 formed of a single leaf spring. These configurations can be similarly employed in a configuration in which the neutralizing cloth 35 is elastically contacted with the end surface of the rotating shaft 33 or a configuration in which the neutralizing cloth 35 is brought into contact with the peripheral surface of the sheet conveying roller. Also in the configuration, the configuration can be simplified and the number of parts can be reduced.
[0039]
Further, by attaching and fixing the neutralizing cloth 35 to the grounding conductive plate 34, positioning, storage management and the like of the neutralizing cloth 35 and the grounding conductive plate 34 are facilitated.
[0040]
Each configuration of the above embodiment can also be applied to the feed roller 7a of the image separating and feeding unit 7 or the installation unit of the document conveying rollers 10 and 11 in the image reading apparatus unit 1 shown in FIG. Therefore, it is possible to prevent a decrease in transportability and a reading failure due to.
[0041]
【The invention's effect】
As described above, according to the present invention, the metal rotating shaft or roller that holds the paper transport roller and the grounding conductive member do not come into direct contact but come in contact through the static eliminating cloth. because, it is possible to suppress the generation of abnormal noise due to friction during rotation of the rotating shaft or roller, the contact also reliably can take ground to stabilize by intervening neutralizing cloth, also a neutralizing cloth Even if it is installed, the lubricating action of the lubricant allows it to rotate smoothly without hindering the operation of the rotating shaft. gap is formed, it becomes possible to discharge the static electricity for the exposed opposing surface of the ground conductive member, removal of static electricity is effectively performed, versus the device body equipped with the sheet conveying apparatus having the static eliminator Static electricity of the adverse effects it is possible to prevent that.
[0042]
Furthermore, by removing the static electricity from the roller by contacting the paper transport roller via the static eliminating cloth, in addition to the above effects, the static eliminating cloth has a cleaning function for the roller that is likely to be contaminated with paper. Can be made.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a facsimile machine for explaining an embodiment of the present invention. FIG. 2 is a perspective view showing a main part of a transport roller portion which is a paper transport roller in the embodiment of the present invention. FIG. 4 is a cross-sectional view of the contact portion between the neutralizing cloth and the rotating shaft of the grounding conductive plate shown in FIG. 2. FIG. 4 is another example of the contact configuration between the neutralizing cloth and the rotating shaft of the grounding conductive plate in the embodiment of the present invention. FIG. 5 is a cross-sectional view of a contact portion between a neutralizing cloth and a roller of a grounding conductive plate, which is a modification of the embodiment of the present invention. FIG. 6 is a cross-sectional view of the grounding conductive plate and static neutralizing in the embodiment of the present invention. Explanatory drawing which shows the contact part of cloth and a roller. [FIG. 7] The top view which shows the other example of the installation structure of the electrically conductive board for earth | ground with respect to the rotating shaft of the embodiment of this invention, and a static elimination cloth. Installation configuration of grounding conductive plate and neutralizing cloth for rotating shaft of embodiment Plan view illustrating another example EXPLANATION OF REFERENCE NUMERALS
DESCRIPTION OF SYMBOLS 1 Image reading part 3 Image forming part 4,5 Paper feed cassette 7 Original separation paper feed part 7a Feed roller 10,11 Document conveyance roller 18 Registration roller 20 Paper discharge roller 25,26 Paper feed roller 27,28 Transport roller 31 Support frame 33 Rotating shaft 34 Grounding conductive plate 34a Exposed facing surface 35 of grounding conductive plate Static elimination cloth h Discharge gap

Claims (9)

In the static eliminator in the paper transport device, wherein the rotary shaft holding the paper transport roller is rotatably supported by a support member and grounds static electricity generated by frictional charging between the roller and the paper. was formed of a conductive metal, this part of the peripheral surface of the metallic rotary shaft via a dividing conductive fabric contacting the ground conductive member, the conductive to the surface of the metallic rotary shaft in said neutralizing cloth An exposed facing surface is provided on the surface of the ground conductive member on the surface where the static elimination cloth is attached so that the ground conductive member does not contact the peripheral surface of the metal rotating shaft. A static eliminator in a paper conveying device, characterized in that Each contacting the neutralizing cloth to the rotating shaft for holding a plurality of said rollers for paper transport, characterized in that is pressed against the metal of the rotation axis of each neutralizing cloth by a common said ground conductive member The static eliminator in the paper conveying apparatus according to claim 1. Wherein said the rotary shaft is brought into contact common to the neutralizing cloth respectively, that is pressed against the neutralizing cloth to the metallic rotary shaft by a common said ground conductive member for holding a plurality of said rollers for paper conveyance The static eliminator in the paper conveying apparatus according to claim 1. In a static eliminator in a paper transport device, wherein an end portion of a rotating shaft that holds a paper transport roller is rotatably supported by a support member and grounds static electricity caused by frictional charging between the roller and the paper. A grounding conductive member is brought into contact with a part of the peripheral surface outside the sheet conveying surface via a neutralizing cloth, and the grounding conductive member is disposed on the roller side on the surface of the grounding conductive member on the surface where the neutralizing cloth is attached. discharging device in the not in contact with the peripheral surface exposed opposing surface for sheet conveying device you characterized by providing a. 5. The static eliminator in the paper conveying device according to claim 4, wherein the static eliminating cloth is brought into contact with a plurality of the paper conveying rollers, and the static eliminating cloth is pressed against the roller by the common conductive member for grounding. apparatus. 5. The sheet conveying apparatus according to claim 4 , wherein the common discharging cloth is brought into contact with a plurality of the sheet conveying rollers, and the discharging cloth is pressed against the rollers by the common conductive member for grounding. Static eliminator in Examples neutralizing cloth, polyethylene terephthalate fibers and nickel, neutralization apparatus in the sheet conveying device according to any one of claims 1 to 6, characterized in that using the cloth-like material woven copper. A paper feed roller that feeds paper from a paper feed cassette loaded with paper, a transport roller that transports paper fed from the paper feed roller, and a registration roller that feeds paper to the image forming unit in a timely manner And at least one of the paper feed roller, the transport roller, the registration roller, and the paper discharge roller in an image forming apparatus in which a paper discharge roller for discharging the paper to the outside of the apparatus is installed in the paper transport path An image forming apparatus, wherein a static eliminator in the paper conveying apparatus according to claim 1 is installed at a location . In the image reading apparatus in which a feed roller that separates and feeds documents one by one from a document setting table and a document transport roller that transports a document fed from the feed roller to a reading sensor is installed in the document transport path, the feed roller 8. A document reading apparatus, comprising: a neutralization device in the sheet conveying device according to claim 1 installed at at least one of the installation positions of the document conveying roller and the document conveying roller .

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