JP2007101778A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of fast processing without contamination in a primary apparatus body by preventing toner from leaking from a cleaner housing by forcibly moving toner cloud in timing where a cleaner blade and a seal slide in contact with a carrier surface. <P>SOLUTION: The image forming apparatus which transfers a toner image formed on a photoreceptor drum surface with toner having a minus potential to a recording paper through an intermediate transfer belt 16 supplying a plus voltage and scrapes off remaining toner by making the cleaner blade 21a and a seal member 82 contact and leave the intermediate transfer belt surface is characterized in that when the belt surface is slid in contact, a bent part 82a of a film member receives the plus voltage to produces an electric field E attracting the suspended toner into the cleaner housing 63 before a bent part 81a of a ground-connected film member 81 on the side of the cleaner blade 21a and the suspended toner is attracted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, is designed to have a structure in which a cleaner blade and a seal installed to scrape away and remove / recover toner remaining on the surface of the carrier are separated from the surface of the carrier. About.

  2. Description of the Related Art Conventionally, an electrophotographic recording type image forming apparatus that exposes and forms an electrostatic latent image based on image data on the surface of a carrier made of a photosensitive member has been known. The toner image on the carrier carried by developing the toner with a developing device is transferred to a recording medium such as recording paper to form an image.

  This type of image forming apparatus includes a first carrier that can form an electrostatic latent image and can carry a toner image obtained by developing the electrostatic latent image, and a transfer position that transfers the toner image to a recording medium. In some cases, a second carrier for receiving the toner image on the surface of the first carrier (primarily transferred) and carrying the toner image on the recording medium is secondarily transferred to a recording medium. In this case, for example, a desired toner image such as a color image can be formed by superimposing the toner images of the respective color toners formed on the surface of the first carrier on the surface of the second carrier. The image can be formed by transferring the image from the surface of the second carrier to a recording medium such as recording paper.

  As described above, in the image forming apparatus including the second carrier, the toner remaining on the surface of the carrier is removed and collected every time the toner images on the surfaces of the first and second carriers are transferred. The quality of the image is guaranteed.

For this reason, the cleaner blade and the seal for removing and collecting the residual toner are always slid on the surface of the first carrier because the toner image obtained by developing the electrostatic latent image is transferred for each development. For example, when forming a color image, the toner image is superimposed on the surface of the second carrier, and then transferred to a recording medium. It is designed to be in sliding contact (see, for example, Patent Documents 1 and 2).
JP 2004-157285 A JP 7-121037 A

  In such a conventional image forming apparatus, when the cleaner blade slidably contacts the surface of the carrier and scrapes the residual toner, the toner to be removed and collected temporarily rises in the cleaner housing. Toner cloud occurs. Since this toner cloud is a floating toner and descends and settles after a certain period of time, when performing image forming processing at a conventional speed, the cleaner blade and the seal are separated from the surface of the second carrier. Even so, the floating toner hardly leaked out of the cleaner housing in the closed space by the timing of the separation.

  However, with the recent high-speed processing of image formation, it is difficult to secure a sufficient time necessary for the toner cloud to settle as a period until the cleaner blade and the seal are separated from the second carrier surface. That is, the cleaner blade or the seal may be separated from the second carrier surface before the toner cloud settles to open the closed space, and the floating toner may leak out of the cleaner housing and contaminate the surroundings. is there. For example, when the cleaner blade or the seal is rotated so as to be separated from the surface of the second carrier, an instantaneous air pressure rises in the cleaner housing to generate an air flow that is ejected to the outside. The floating toner may leak out of the cleaner housing. If floating toner leaks from the cleaner housing in this way, the toner quality formed on the surfaces of the first and second carriers is mixed and mixed with toner that does not originally exist, and the image quality deteriorates. As a result, the floating toner that has leaked out accumulates on the surrounding members and is contaminated, making maintenance work difficult.

  Therefore, the present invention restricts the toner from leaking from the cleaner housing by forcibly moving the toner cloud at the timing when the cleaner blade and the seal are in sliding contact with the surface of the carrier, so that there is no contamination in the apparatus main body. An object is to provide an image forming apparatus capable of high-speed processing.

  According to a first aspect of the present invention, there is provided an image forming apparatus for solving the above-described problems. A first carrier that carries a toner image obtained by developing an electrostatic latent image based on image data, and a primary transfer received from the surface of the first carrier. A second carrier for secondary transfer of the toner image to the recording medium; and a cleaner unit disposed on each of the carriers to collect residual toner on the surface of the carrier. In an image forming apparatus that forms an image by transferring and fixing a toner image onto a recording medium via a second carrier, a cleaner unit for the second carrier is a cleaner that collects residual toner on the surface of the second carrier. A housing, a cleaner blade that slides on the surface of the second carrier and scrapes and removes toner remaining after the transfer of the toner image, and a cleaner housing that slides on the surface of the second carrier and closes together with the cleaner blade. A seal that defines a space, and the cleaner blade and the seal are separated from and abutted on the surface of the second carrier at a preset timing so as to pass or collect the toner on the surface of the second carrier. An image forming apparatus that operates to form a desired toner image on the surface of the second carrier, and is electrically connected to the conductive layer formed so as to spread over the entire surface of the second carrier. An electrode portion formed so as to extend in the circumferential direction at a lateral end with respect to the rotation direction of the second carrier surface so that power can be supplied from the power source of the apparatus main body, and a cleaner blade with respect to the rotation direction of the second carrier surface An electric field generating means for generating an electric field for moving the toner removed from the surface of the second carrier near the surface of the second carrier on the upstream side of the second carrier. Pair with rotation direction One or two or more sets of opposing members that generate an electric field by applying a potential difference are provided upstream of the cleaner blade, and one of the opposing members is slidably contacted with the electrode portion and is connected to the power source of the apparatus main body. (2) By receiving a voltage supplied to the carrier, an electric field is generated between the opposite member and the other of the opposing members to generate an electric field that attracts toner into the cleaner housing.

  In the present invention, one of the opposing members can receive (apply) the voltage supplied from the device body to the conductive layer from the electrode portion on the surface of the second carrier by sliding contact with the electrode portion and conducting contact. And a potential difference can be generated between the other of the opposing members. As a result, the floating toner in the toner cloud generated when the cleaner blade slides on the surface of the second carrier and scrapes the residual toner is moved and adsorbed (attached) into the cleaner housing by the electric field between the opposing members. be able to. Therefore, without adding a circuit for applying a voltage to the opposing member, an electric field can be generated by applying a potential difference between the opposing members, and even if the seal is separated from the surface of the second carrier, It is possible to prevent the floating toner from leaking out of the cleaner housing and contaminating surrounding members.

  In addition to the specific matters of the first invention, the second invention of the image forming apparatus that solves the above problem is configured by a seal in which one of the opposed members is in contact with the surface of the second carrier and is in sliding contact with the electrode portion. It is characterized by being.

  In the present invention, the seal that comes into contact with the surface of the second carrier is also slidably contacted with the electrode portion. Therefore, in particular, a potential difference is given to the other of the opposing members without adding a separate opposing member. An electric field that attracts toner into the housing can be generated. Therefore, it is possible to prevent the floating toner from leaking out of the cleaner housing at a low cost.

  According to a third aspect of the image forming apparatus for solving the above problem, in addition to the specific matter of the second aspect, the seal constituting one of the opposing members is bent inward of the cleaner housing. The other of the opposing members extends inward of the cleaner housing and is opposed to the seal while being supported by a cleaner blade that comes into contact with and separates from the surface of the second carrier.

  In this invention, the seal to which the voltage is applied by separating and contacting the surface of the second carrier is bent and formed into a shape extending in the housing, and the member facing the seal is supported by the cleaner blade and sealed. By applying a potential difference with respect to, an electric field for attracting toner can be generated in the housing without adding an independent separate member in the housing. Therefore, it is possible to prevent the floating toner from leaking out of the cleaner housing at a lower cost.

  As described above, according to the present invention, the toner cloud in the cleaner housing generated when the cleaner blade is brought into sliding contact with the surface of the second carrier causes a potential difference between the electrode portion on the surface of the second carrier and the opposing member. The voltage can be received and sucked and moved into the cleaner housing, and the toner cloud leaks out of the cleaner housing, and the surrounding members, for example, the image forming area on the surface of the second carrier to which the toner is transferred, etc. It is possible to prevent contamination. Therefore, it is possible to avoid at low cost that the quality of the toner image is deteriorated or that the inside of the apparatus main body is contaminated to make the maintenance work difficult.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described based on the drawings. 1 to 7 are views showing a first embodiment of an image forming apparatus according to the present invention.

  1 and 2, the image forming apparatus is a printer that is used by connecting to an external device such as a personal computer PC for creating and outputting an image such as a character. An image recording apparatus 10 that receives image data and records and forms it on one side or both sides of a recording sheet (recording medium) by an electrophotographic method, and transports a plurality of stacked recording sheets to the image recording apparatus 10 and images. An image is recorded on the recording sheet by including a sheet conveying device 30 that unloads the recording sheet that has been recorded and stacked, and a control unit 40 that performs overall control of the image recording device 10 and the sheet conveying device 30. Form and print out.

  In brief, the image recording apparatus 10 is based on a laser beam scanning device 11 that scans the laser beam L based on image data, and the laser beam L emitted from the laser beam scanning device 11 and scanned, based on the image data. A photosensitive drum (first carrier) 12 on which an electrostatic latent image is exposed and formed on the surface, and a charger for charging the outer peripheral surface of the photosensitive drum 12 so that an electrostatic latent image can be formed by irradiation with laser light L 13 and the photosensitive drum 12 by storing yellow (Y), cyan (C), magenta (M), and black (K) toners, and selectively adhering (carrying) the toners by friction charging. A developing cartridge 14 for each color (only one portion is shown) for developing the electrostatic latent image on the surface with toner, and the developing cartridge 14 is housed in an installation space 15a for each color, and the rotation shaft 15b is set in the middle. And a developing rotary unit 15 that rotates on the photosensitive drum 12, and a toner image (monochrome image or color image) that can be transferred and recorded on a recording sheet by receiving the toner image developed on the photosensitive drum 12 by primary transfer. The toner image carried on the intermediate transfer belt 16 is transferred by press-contacting (niping) the intermediate transfer belt (second carrier) 16 and the conveyed recording paper so as to be sandwiched between the intermediate transfer belt 16. In addition, the toner image is fixed by heating and pressing the transfer roller 17 that conveys the recording paper to the downstream while sandwiching the recording paper, and the recording paper that has been transferred with the toner image transferred thereto, and the recording paper is further downstream. The fixing roller pair 18 that is nipped and conveyed to the side and the toner remaining on the surface of the photosensitive drum 12 are removed from the cleaner blade 1. a developing-side cleaner unit 19 that is collected and stored by a, a transfer-side cleaner unit 21 that collects and stores toner remaining on the surface of the intermediate transfer belt 16 by a cleaner blade 21a, and an outer peripheral surface side of the developing rotary unit 15 The toner that scatters to the periphery when the suction fan 24 sucks the downstream side in the rotation direction of the photosensitive drum 12 (developing roller 14a) in particular through the exhaust ducts 22 and 23 disposed so as to cover the exhaust duct 22, And an exhaust unit 26 that collects with a filter 25 interposed between them.

  As a result, the image recording apparatus 10 develops the electrostatic latent image based on the image data formed on the surface of the photosensitive drum 12 by the laser beam scanning device 11 in the development rotary unit 15 switched according to the image data. The cartridge 14 develops toner, and thereafter, the toner image on the photosensitive drum 12 is primarily transferred to the intermediate transfer belt 16 and secondarily transferred onto the recording paper conveyed by the paper conveying device 30. After recording, the fixing roller pair 18 is heated and pressed to fix the image to form an image. At this time, for example, when the developing rotary unit 15 contains a developing cartridge 14 containing toner of each color of yellow (Y), cyan (C), magenta (M), and black (K), the photosensitive drum By switching the color of the toner that develops the electrostatic latent image on the image 12, the toner of each color is overlaid or selected based on the received image data, and a color image to a single color image is printed on a recording sheet. be able to. Further, when the developing rotary unit 15 contains the developing cartridge 14 containing toner of the same color, for example, black (K), in all the developing cartridges 14, the electrostatic latent image on the photosensitive drum 12. Can be used as a dedicated machine that sequentially switches the developing cartridge 14 that develops the image and continuously prints and forms monochrome images on recording paper.

  Briefly described, the paper transport device 30 is detachably set on the lower part of the main body of the device, a paper cassette 31 on which a plurality of recording papers are stacked, and a recording paper raised by a lifting plate 31a on the bottom surface of the paper cassette 31. A pickup roller 32 that pulls out the uppermost recording sheet by rotating in contact with the bundle and sends it to the conveyance path f, and receives the recording sheet sent out by the pickup roller 32 and holds it in the downstream conveyance path f. The intermediate transfer belt 16 and the transfer roller 17 of the image recording apparatus 10 receive the recording paper in the transport path f transported by the relay transport roller pair 33a, 33b transported and the relay transport roller pair 33a, 33b, and form an image by the intermediate transfer belt 16 and the transfer roller 17. A pair of registration rollers 34 that are nipped and conveyed at a position, and an intermediate transfer belt from the pair of registration rollers 34 6 and the transfer roller 17 and the fixing roller pair 18 are conveyed to receive a recording sheet having a fixed image formed on one side thereof, and the recording sheet is unloaded onto the discharge table 39 on the upper part of the apparatus main body. A pair of paper discharge rollers 35a and 35b for discharging and stacking are provided. Note that the intermediate transfer belt 16 and the transfer roller 17 and the fixing roller pair 18 of the image recording apparatus also have a function of conveying a recording sheet, and thus constitute a part of the sheet conveying apparatus 30.

  As a result, the sheet conveying device 30 transfers the recording sheet pulled out from the sheet cassette 31 by the pickup roller 32 to the registration roller pair 34 via the relay conveying roller pair 33a, 33b, and then the registration roller pair 34 In synchronization with the operation of the image recording apparatus 10, the intermediate transfer belt 16 and the transfer roller 17 are fed to an image recording position where the image is pressed, and the toner image on the intermediate transfer belt 16 is transferred and recorded. Then, the recording paper fixed by the fixing roller pair 18 is received by the paper discharge roller pairs 35a and 35b, and is carried out and discharged onto the paper discharge table 39 to be stacked.

  Here, the sheet conveying device 30 is disposed in the re-conveying path r for reversing the recording sheet on which the image is formed on one side and sending it to the conveying path f on the upstream side of the registration roller pair 34 and the path r. The intermediate conveyance roller pair 37 is provided, and the intermediate conveyance roller pair 37 receives the recording sheet sent into the reconveyance path r when the paper discharge roller pair 35a, 35b is reversed and is received by the registration roller pair 34. By passing, it is possible to form an image on both sides of the recording paper. The sheet conveying device 30 also includes a manual feed path m for sending a manually fed recording sheet to a conveyance path f on the upstream side of the registration roller pair 34, and a manual feed roller pair 38 disposed in the path m. The recording paper inserted into the manual feed path m is received by the pair of manual feed rollers 38 and transferred to the registration roller pair 34, whereby an image can be formed on one side or both sides of the recording paper.

  In brief, the control unit 40 executes various processing procedures in accordance with a processing program stored in a memory by a CPU (not shown), and thereby outputs various information such as a print command to and from the printer driver of the personal computer PC. A controller unit 41 that exchanges and receives image data such as text to form an image on recording paper and temporarily stores it in a memory (not shown), and a controller unit according to a control program stored in the ROM 43 by the CPU 42 41, for example, exchanges various information between the image recording apparatus 10 and the sheet conveying apparatus 30 while using the RAM 45 as a work area in parallel with receiving image data in page units and temporarily storing it in the main body memory 44. The image based on the image data An engine control unit 46 to be formed on recording paper, is built on a circuit board mounted in the apparatus main body.

  As a result, the control unit 40 receives the image data (image information signal) received from the personal computer PC from the so-called RGB data of red (R), green (G), and blue (B). Is converted into image data of so-called YMCK data of yellow (Y), magenta (M), cyan (C), and black (K) that can be printed, and is read from the memory, for example, in units of pages, and the engine control unit 46 The engine control unit 46 controls the image recording apparatus 10 and the sheet conveying apparatus 30 based on the image data to form an image on a recording sheet.

  The control unit 40 uses the timer function 42a built in the CPU 42 to measure various processing times, etc., so that each part of the apparatus operates optimally and executes this image formation control. The recording apparatus 10 and the sheet conveying apparatus 30 are connected to each other via the I / O interface 47 so that various information can be exchanged between the controller section 41 and the engine control section 46, and the engine control section 46 is connected to the image recording apparatus. 10, the digital signal (D) is converted into an analog signal (A), or the analog signal is converted into a digital signal so that various information exchanged between the paper transport device 30 and the controller unit 41 can be processed respectively. A D / A converter 48 and an A / D converter 49 for conversion are provided.

  The image forming apparatus employs a configuration in which the toner image on the surface of the photosensitive drum 12 is transferred to a recording sheet via the intermediate transfer belt 16, and therefore, the intermediate transfer belt 16 is also the same as the photosensitive drum 12. In addition, it is necessary to transfer a toner image formed with high accuracy onto a recording sheet with high quality. Therefore, as shown in FIG. 3A, the intermediate transfer belt 16 has a conductive layer 16c formed on the entire surface between the belt main body 16a and the resistor layer 16b, and resistance on the side thereof. Instead of the body layer 16b, an electrode portion 16d that is electrically connected to the conductive layer 16c is formed and exposed over the entire circumference, and the toner charged to a negative potential by frictional charging in the developing cartridge 14 is positively applied. The electrode roller 51 is brought into pressure contact with the electrode portion 16d so as to be attracted (attached) to the surface, and a positive voltage is applied, so that the toner can be held evenly over the entire surface. . The intermediate transfer belt 16 is pressed against the photosensitive drum 12 by being pressed against the primary transfer roller 52 from the back side, so that the photosensitive drum 12 is connected to the intermediate transfer belt 16 as shown in FIG. The electrode portion 16d exposed on the side is in contact with the photosensitive layer 12b on the surface of the conductive portion 12a. When there is a pinhole or the like in the photosensitive layer 12b, the electrode portion 16d is originally insulated from the intermediate transfer belt 16. Therefore, there is a possibility that current leakage may occur. Therefore, an insulating portion 12c that can be interposed in a sufficient area between the electrode portion 16d is formed over the entire circumference.

  In this image forming apparatus, since the quality of the toner image carried by the intermediate transfer belt 16 affects the image quality formed on the recording paper, the development quality and the transfer quality are confirmed from the toner image before being transferred to the recording paper. Therefore, it is designed to check the density of the toner image at an arbitrary timing. For example, a so-called patch sensor 27 composed of a reflection type photosensor is disposed and controlled at a position facing the intermediate transfer belt 16 at a position where the backup roller (pulley) 53 is separated from the transfer roller 17. The CPU 42 of the engine control unit 46 is connected to the engine control unit 46 of the unit 40 and emits light toward the transfer surface (toner image) on the surface of the intermediate transfer belt 16, and the toner image on the transfer surface. Based on the detection signal from the patch sensor 27 that photoelectrically converts the reflected light from the toner, the density (the toner coverage) of the toner image (toner image on the intermediate transfer belt 16) formed on the photosensitive drum 12 by the developing cartridge 14 is calculated. Evaluate and adjust various conditions.

  That is, the CPU 42 of the engine control unit 46 determines the density of the toner image on the surface of the intermediate transfer belt 16 formed and transferred based on the patch image data prepared in advance when the power is turned on or when the developing cartridge 14 is replaced. After detection by the patch sensor 27, the bias voltage supplied from the power supply unit 28 between the photosensitive drums 12 and between the intermediate transfer belts 16 is changed based on the detection information of the density of the toner image, and the photosensitive drum 12 is changed. The image quality is maintained above a certain level by adjusting the development density and transfer quality of the electrostatic latent image on the surface. The toner image of the patch image for which density detection has been completed is scraped and collected by the cleaner blade 21a of the transfer side cleaner unit 21 before being transferred and recorded on the recording paper. Here, the arrangement position of the power supply unit 28 is not limited to the position shown in the figure, and it goes without saying that it may be arranged at other positions or distributed.

  By the way, this image forming apparatus employs a configuration in which the toner image on the surface of the photosensitive drum 12 is transferred to a recording sheet via the intermediate transfer belt 16, and therefore, as shown in FIG. A projecting piece (a so-called shim) 16e that protrudes outward in the plane direction is disposed on one side of the engine, and the proximity sensor 29 detects the projecting piece 16e every rotation, whereby the engine control unit 46 The CPU 42 controls the respective units 10 and 30 so as to synchronize the rotation operation of the photosensitive drum 12 and the conveyance operation of the recording paper and the rotation operation of the intermediate transfer belt 16. The intermediate transfer belt 16 circulates and rotates, whereas the developing rotary unit 15 needs to sequentially switch the developing cartridge 14 that develops the toner image, particularly when forming a color image. For this reason, the intermediate transfer belt 16 is larger than the length of the long side of a recording paper size, for example, an A4 size single-sheet pick-up device (of course, it may be a device that picks up two or more sheets). The developing rotary unit 15 is set to a large length and carries a toner image to be transferred onto the recording paper, whereas the developing rotary unit 15 is configured to have a rear end and a front end of an A4 size toner image on the intermediate transfer belt 16. The switching operation of the developing cartridge 14 is completed during the rotational movement (between the rear end and the front end of the image forming area of the recording paper, during the so-called paper interval t).

  Here, in the developing-side cleaner unit 19, the toner image obtained by developing the electrostatic latent image on the surface of the photosensitive drum 12 is continuously transferred (primarily transferred) to the intermediate transfer belt 16. The toner remaining on the surface of the photosensitive drum 12 after being transferred to the surface of the photosensitive drum 12 is always scraped and cleaned by the cleaner blade 19a in order to form the electrostatic latent image with high accuracy and form a high-quality toner image. is important. That is, in the developing side cleaner unit 19, the cleaner blade 19a is always in sliding contact with the surface of the photosensitive drum 12, so that residual toner is scraped off and collected in a cleaner housing (not shown). A flexible seal member 19b is slidably contacted with the surface of the photosensitive drum 12 upstream of the cleaner blade 19a so that the collected residual toner does not float and leak outside, thereby closing the recovery space of the cleaner housing. Has been.

  On the other hand, since the transfer-side cleaner unit 21 carries the toner image on the surface of the intermediate transfer belt 16 that has been primarily transferred from the surface of the photosensitive drum 12 until it is secondarily transferred to the recording paper, in particular, a color image is formed. In this case, the toner image on the surface of the intermediate transfer belt 16 is secondarily applied to the recording sheet in order to superimpose the color toners of yellow (Y), cyan (C), magenta (M), and black (K). Operates to allow patrol without scraping until transfer. That is, in the transfer side cleaner unit 21, the cleaner blade 21 a is separated from the surface of the intermediate transfer belt 16 so as not to scrape off the toner image during the preset timing period, or the surface of the intermediate transfer belt 16. The residual toner is scraped and brought into contact with the toner and scraped off and collected in the cleaner housing 63 (see FIG. 5). Similarly, the scraped residual toner floats to the outside. In order to prevent leakage, the flexible seal member 82 also comes into contact with (slidably contacts with) the surface of the intermediate transfer belt 16 on the upstream side of the cleaner blade 21 a to close the recovery space of the cleaner housing 63. Even when the monochrome image is continuously formed, the cleaner blade 21a and the seal member 82 are separated from the surface of the intermediate transfer belt 16 and contact the surface of the intermediate transfer belt 16 at the timing when the processing for the set number of sheets is completed. In some cases, it is designed to scrape and collect residual toner.

  In such a transfer-side cleaner unit 21, when the cleaner blade 21 a scrapes residual toner from the surface of the intermediate transfer belt 16, a so-called toner cloud is temporarily generated in which the toner scoops up in the cleaner housing 63. As the floating toner in the toner cloud descends and settles down after a certain period of time, even if the cleaner blade 21a and the seal member 82 are separated from the surface of the intermediate transfer belt 16, they float from the cleaner housing 63. The toner does not leak out. However, the image processing speed is increased as the period from when the cleaner blade 21a and the seal member 82 come into contact with the surface of the intermediate transfer belt 16 until the residual toner is scraped and separated until the toner clad of the residual toner settles. As a result, when there is no time for switching between the various operations and a sufficient time cannot be secured, the cleaner blade 21a and the seal are sealed before the toner cloud of the floating toner that has been sprinkled by the sliding contact of the cleaner blade 21a settles. As the member 82 moves away from the surface of the intermediate transfer belt 16, an instantaneous pressure increase occurs due to the cleaner blade 21 a and the seal member 82 rotating toward the inside of the toner housing 63, and the air flow that is ejected to the outside. As a result, floating toner leaks from the cleaner housing 63. Mau there is a risk. In particular, the toner image of the patch image and the toner image when a jam error that causes the recording paper to be jammed are removed and collected from the surface of the intermediate transfer belt 16 by the transfer-side cleaner unit 21 without being transferred to the recording paper. Therefore, at this time, a large amount of toner cloud may be generated, and a large amount of floating toner may leak.

  In view of this, the transfer-side cleaner unit 21 forcibly settles the toner cloud that rises when the cleaner blade 21a is in sliding contact with the surface of the intermediate transfer belt 16, and reliably removes residual toner on the surface of the intermediate transfer belt 16. A function (electric field generating means) is added that prevents toner floating in the toner cloud from leaking out of the cleaner housing 63 even when the cleaner blade 21a and the seal member 82 are separated from the surface of the intermediate transfer belt 16 while being collected. Has been.

  Specifically, as shown in FIG. 5, the transfer-side cleaner unit 21 supports a blade support member 61 that operates to contact and separate from the surface of the intermediate transfer belt 16 while supporting the cleaner blade 21 a, and a seal member 82. However, a seal support member 62 that operates so as to contact with and separate from the surface of the intermediate transfer belt 16 and a cleaner housing 63 that defines a recovery space for residual toner removed from the surface of the intermediate transfer belt 16 are provided. These various members 61 to 63 are more intermediate than the patch sensor 27 installed so as to face the intermediate transfer belt 16 wound around the backup roller 53 on the side separated from the transfer roller 17. It is arrange | positioned downstream with respect to 16 rotation directions.

  The blade support member 61 supports the base end side of the cleaner blade 21a so that the tip end portion can freely swing. The tip end corner portion of the cleaner blade 21a abuts against the surface of the intermediate transfer belt 16. It is pivotally supported by the rotation shaft 61a so as to rotate in the direction of contact or separation. The cleaner blade 21a is in sliding contact with the surface of the intermediate transfer belt 16 wound around the backup roller 53 below the leftmost end surface in FIG. As a result, when the residual toner on the surface of the intermediate transfer belt 16 is scraped off, it is sprinkled to generate a toner cloud.

  Similarly, the seal support member 62 is attached and supported on the proximal end side of the seal member 82 so that the distal end side can freely swing. Similarly to the blade support member 61, the distal end side of the seal member 82 is supported. Rotation shaft for rotating the intermediate transfer belt 16 wound around the backup roller 53 from the vicinity of the leftmost end surface in FIG. 62a is pivotally supported. Here, since the seal member 82 has a structure in which the residual toner is slidably pressed against the surface of the intermediate transfer belt 16 as described above, the residual toner is removed from the surface of the intermediate transfer belt 16 by the slidable contact as in the developing cartridge 14. It is made of a charge train material that is charged again to a negative potential opposite to the positive potential, for example, a urethane-based material.

  The cleaner housing 63 is disposed on the side where the residual toner scraped off from the surface of the intermediate transfer belt 16 by the cleaner blade 21a falls, and is formed so as to define a recovery space for the residual toner. A sponge material 63a that elastically deforms is interposed between the blade support member 61 that supports 21a and a sponge material 63b that elastically deforms between the seal support member 62 that supports the seal member 82. In other words, a gap through which the collected toner leaks regardless of these rotating operations is filled. In the lower part of the cleaner housing 63, the collected toner is collected in a tank (not shown) by rotating the screw at a preset timing so that the collected space is not filled with the collected toner. A conveying screw 63c that conveys the toner to the surface is disposed.

  In the transfer-side cleaner unit 21, a seal member 82 produced by forming a conductive polyethylene material into a film shape is attached to and supported by a seal support member 62 so as to be slidable on the surface of the intermediate transfer belt 16. On the other hand, the blade support member 61 is similarly supported by a film member 81 produced by forming a conductive polyethylene material into a film shape, stuck to the cleaner blade 21a and sandwiched therebetween. A potential difference is applied between the seal member 82 and the film member 81 to generate an electric field E (see FIG. 8), and the toner floating in the cleaner housing 63 is attracted (sucked) to either one. A function to prevent leakage of adhering and retaining floating toner is added.

  Specifically, the seal member 82 includes a sliding contact portion 82b attached to the seal support member 62 so as to be in sliding contact with the surface of the intermediate transfer belt 16 by bending and bending one film. A bent portion 82a that is connected to the slidable contact portion 82b and is bent so as to extend in the vertical direction of the surface of the intermediate transfer belt 16 (normal direction inside the cleaner housing 63). It is equipped with. As will be described later, the seal support member 62 is made of, for example, a conductive material such as a sheet metal so that the potential applied to the seal member 82 is uniform in the length direction (width direction of the intermediate transfer belt 16). It is produced by.

  Further, the film member 81 includes a bent portion 81a that is bent so as to extend inward of the cleaner housing 63 from the back side of the tip corner portion that is in sliding contact with the surface of the intermediate transfer belt 16 of the cleaner blade 82. When the blade 21a and the seal member 82 are brought into sliding contact with the surface of the intermediate transfer belt 16, the bent portion 81a is formed so as to face in a posture parallel to the bent portion 82a of the seal member 82. The blade support member 61 is made of, for example, a conductive material such as a sheet metal, and is grounded so that it is grounded and has a zero potential.

  Specifically, when the CPU 42 of the engine control unit 46 receives, for example, color image data, yellow (Y), cyan (C) so as to be synchronized with the detection signal Vsync of the protruding piece 16e on the side of the intermediate transfer belt 16. ), Each color toner image of the electrostatic latent image formed on the surface of the photosensitive drum 12 based on the image data for each color of magenta (M) and black (K) is primarily transferred and superimposed on the surface of the intermediate transfer belt 16. Thus, after a color toner image is formed and subjected to secondary transfer (secondary transfer after the primary transfer of the fourth color toner image) onto the conveyed recording paper, the transfer side cleaner unit 21 in FIG. As shown, the blade support member 61 and the seal support member 62 are rotated so that the seal member 82 is brought into contact with the surface of the intermediate transfer belt 16 together with the cleaner blade 21a. The toner cloud floating up by scraping the cleaner blade 21a by the contact is blocked by the sealing member 82 so that the floating toner in the toner cloud does not leak out of the cleaner housing 63, and the residual toner on the surface is scraped off and removed. And collect.

  As described above, when the cleaner blade 21a and the seal member 82 are in sliding contact with the surface of the intermediate transfer belt 16, the bent portion 82a of the seal member 82 and the bent portion 81a of the film member 81 face each other. The seal member 82 is slidably contacted with the slidable contact portion 82b over the entire circumference of the electrode portion 16d of the intermediate transfer belt 16, so that a positive voltage similar to that of the intermediate transfer belt 16 is applied and substantially the same potential is applied. In addition, since the film member 81 is grounded through the blade support member 61 connected to the ground, the film member 81 is at zero potential, so that an electric field E having a large electric field strength is effective between the bent portions 82a and 81a. Can be generated automatically. Here, as shown in FIG. 3C, the seal member 82 is brought into conductive contact with the electrode portion 16d of the intermediate transfer belt 16 by slidingly contacting the surface of the intermediate transfer belt 16 in a posture that the sliding contact portion 82b follows. However, the portion of the sliding contact portion 82b corresponding to the electrode portion 16d can be brought into conductive contact with high reliability, for example, by thickening only a part of the film or by stacking two films. Also good.

  As a result, the cleaner blade 21a is brought into sliding contact with the surface of the intermediate transfer belt 16 without causing the CPU 42 of the engine control unit 46 to execute control to apply a voltage to the seal member 82 (without requiring a voltage application circuit). An electric field E generated between the sealing member 82 and the bent portions 82a and 81a of the film member 81 is generated by the floating toner (toner that is frictionally charged to a negative potential by the developing cartridge 14 and the sealing member 82). It can be sucked inward of the cleaner housing 63 and adsorbed to one of the bent portions 82a to forcibly settle down.

  Next, after the downstream side of the image forming area of the intermediate transfer belt 16 has passed the facing position (sliding contact position) of the seal member 82, the CPU 42 of the engine control unit 46 performs the next image forming process on the surface of the intermediate transfer belt 16. As shown in FIG. 7, the seal support member 62 is rotated so that only the seal member 82 is separated from the surface thereof with a margin so as not to affect the toner image carried on the image forming area.

  As described above, when the seal support member 62 is rotated and the seal member 82 is separated from the surface of the intermediate transfer belt 16, the sliding contact portion 82b of the seal member 82 is interlocked with the separation operation, and the electrode portion 16d on the surface thereof. The application of the positive voltage is also cut off from the distance, so that the potential difference between the bent portions 82a and 81a of the seal member 82 and the film member 81 can be eliminated and the electric field E between them can be extinguished. The floating toner adsorbed by the potential of the member 82 floating is peeled off into the cleaner housing 63 and collected. As a result, the toner cloud in the cleaner housing 63 can be collected, and even if the cleaner blade 21a and the seal member 82 are separated from the surface of the intermediate transfer belt 16, the floating toner in the toner cloud leaks out of the cleaner housing 63. It can be restricted from going out.

  After this, the CPU 42 of the engine control unit 46 determines that at least the facing position is the sliding contact position of the cleaner blade 21a from the timing when the downstream side of the image forming area on the surface of the intermediate transfer belt 16 passes the facing position of the seal member 82. (Maximum before the inter-paper area between the image forming areas passes) and the non-image forming area of the intermediate transfer belt 16 (the gap between the trailing edge and the leading edge of the image forming area of the recording paper) After the toner adhering to the surface of the intermediate transfer belt 16 up to the upstream side of the region corresponding to the period t is removed and collected by the cleaner blade 21a, the blade support member 61 is rotated to move the cleaner blade 21a to the intermediate transfer belt 16. Separate from the surface.

  As described above, in the present embodiment, the seal member 82 and the film member 81 that also configure the opposing members in the seal support member 62 and the blade support member 61 using existing members without providing a special voltage application circuit. The seal member 82 can receive the voltage supplied by the electrode portion 16d of the intermediate transfer belt 16 simply by supporting the film member 81. When the film member 81 is grounded, the seal member 82 is connected to the inside of the cleaner housing 63. The electric field E can be efficiently generated between the bent portions 82a and 81a. Thus, even when the seal member 82 of the transfer side cleaner unit 21 is separated from the surface of the intermediate transfer belt 16 at an early stage as the image forming process is accelerated, the cleaner blade 21a scrapes the residual toner on the surface of the intermediate transfer belt 16. The toner cloud floating toner generated at the time of removal can be effectively sucked and adsorbed to the bent portion 82a before the seal member 82 is separated. Accordingly, the floating toner does not adhere to and contaminate each part of the surrounding apparatus. For example, the adhering / remaining in the image forming area of the intermediate transfer belt 16 causes color mixture to deteriorate the image quality. It is possible to prevent the maintenance work from becoming difficult due to the floating toner adhering around the transfer-side cleaner unit 21.

  As another aspect of this embodiment, in this embodiment, the blade support member 61 is grounded and the film member 81 is set to zero potential to generate the electric field E. It goes without saying that the electric field E having a larger electric field strength can be generated by applying a negative voltage during a preset timing period. In this case, the floating toner in the toner cloud can be sucked and adsorbed with a larger force.

  Further, here, an example will be described in which the image forming area is set at a fixed position in synchronization with the detection signal Vsync of the protruding piece 16e disposed on the side of the intermediate transfer belt 16 that rotates endlessly. For example, when a seamless intermediate transfer belt without a joint is installed and the image forming process is repeated by repeating the image forming area and the inter-paper position (non-image forming area) regardless of the rotation position. May be processed similarly.

  Next, FIGS. 8 to 10 are views showing a second embodiment of the image forming apparatus according to the present invention. Here, in this embodiment, since it is comprised substantially the same as the said 1st Embodiment, the same code | symbol is attached | subjected to the same structure and a characteristic part is demonstrated (other embodiment demonstrated below). The same applies to the above).

  In FIG. 8, the transfer-side cleaner unit 21 of this image forming apparatus includes a flat plate member 83 made of a conductive material such as a sheet metal, for example, fixed in the cleaner housing 63. It is grounded so that it becomes zero potential by being connected. Further, the flat plate member 83 is designed so that both ends in the width direction of the intermediate transfer belt 16 are fixed to the wall surface of the cleaner housing 63 and one end side is close to the surface of the intermediate transfer belt 16. The flat plate member 83 is provided with the bent portion 81a of the film member 81 and the seal member 82 when the seal member 82 of the seal support member 62 and the cleaner blade 21a of the blade support member 61 are brought into sliding contact with the surface of the intermediate transfer belt 16. The cleaner housing 63 is mounted so as to face each other in a posture parallel to each other and located between the portions 82a.

  Further, unlike the above-described embodiment, the blade support member 61 is, for example, on the surface of the intermediate transfer belt 16 during a preset timing period so as to generate an electric field E between the flat plate member 83 facing the blade support member 61. It is designed to apply a positive voltage during the period in which the cleaner blade 21a is in sliding contact.

  As a result, in the transfer side cleaner unit 21, as shown in FIG. 9, the blade support member 61 and the seal support member 62 rotate to bring the cleaner blade 21a and the seal member 82 into sliding contact with the surface of the intermediate transfer belt 16. The sliding contact portion 82b of the seal member 82 is in sliding contact (conduction contact) over the entire circumference of the electrode portion 16d of the intermediate transfer belt 16, so that a positive voltage similar to that of the intermediate transfer belt 16 is applied. When the bent portion 82a of the seal member 82 is grounded and faces the flat plate member 83 having a zero potential in close proximity to each other, an electric field E having a larger electric field strength than the above-described embodiment is generated between them. It can be generated effectively. At the same time, the bent portion 81a of the film member 81, which is applied with a positive voltage similar to that of the seal member 82 and is at substantially the same potential, similarly faces the flat plate member 83 in the same manner, so that the electric field strength is high. The electric field E can be effectively generated between these.

  Therefore, the toner cloud that is rolled up when the cleaner blade 21 a comes into sliding contact with the surface of the intermediate transfer belt 16 is formed between the bent portion 81 a of the inner film member 81 of the cleaner housing 63 or the bent portion 82 a of the seal member 82 and the flat plate member 83. While being sucked in between and divided, it can be forcedly settled by being attracted to the respective bent portions 81a and 82a. Thereafter, as shown in FIG. 10, the seal support member 62 is rotated to move the sliding contact portion 82b of the seal member 82 away from the surface of the intermediate transfer belt 16, and thereafter, the cleaner blade 21a. In conjunction with the movement away from the surface of the intermediate transfer belt 16, the potential difference between the bent portions 82a, 81a of the seal member 82 and the film member 81 and the flat plate member 83 is eliminated, and the electric field E between them is sequentially extinguished. The floating toner adsorbed by the potential of the seal member 82 and the film member 81 floating is peeled off into the cleaner housing 63 and collected. As a result, the toner cloud in the cleaner housing 63 can be collected, and even if the cleaner blade 21a and the seal member 82 are separated from the surface of the intermediate transfer belt 16, the floating toner in the toner cloud leaks out of the cleaner housing 63. It can be restricted from going out.

  As described above, in the present embodiment, in addition to the effects of the above-described embodiments, the flat plate member 83 to be grounded is interposed between the film member 81 and the bent portions 81a and 82a of the seal member 82, whereby the seal member The electric field E is generated on each of the 82 side and the film member 81 side, and the toner cloud can be divided and sucked, and the floating toner can be collected by being attracted to the bent portions 81a and 82a. Therefore, it is possible to more effectively avoid the deterioration of image quality and the maintenance workability caused by the leakage of floating toner to the outside.

  As another aspect of the present embodiment, in the present embodiment, the electric field E is generated by connecting the flat plate member 83 to the ground and making it zero potential. It goes without saying that the electric field E can be generated with a larger electric field intensity by applying a negative voltage during the period. In this case, the floating toner in the toner cloud can be sucked and adsorbed with a larger force.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea. For example, in the above-described embodiment, the case of an apparatus including an intermediate transfer belt for supplying voltage will be described as an example. However, the present invention is not limited to this. Needless to say, the apparatus includes a roller-shaped member as a member for carrying toner. The present invention can also be applied to an apparatus, and in the case of an intermediate transfer belt that cannot supply voltage, the same operation and effect can be obtained by adopting a structure in which a voltage can be applied to a back-up backup roller.

1 is a perspective front view illustrating a schematic overall configuration of a first embodiment of an image forming apparatus according to the present invention. It is a related block diagram explaining the control. 2A and 2B are diagrams illustrating the structure of the intermediate transfer belt, wherein FIG. 1A is a partial cross-sectional configuration diagram illustrating a structure for supplying voltage, and FIG. 2B is a cross-sectional configuration illustrating a structure of a photosensitive drum corresponding to the structure. FIG. 3C is a cross-sectional configuration diagram showing the structure of the seal member in the transfer side cleaner unit corresponding to the structure. FIG. 6 is a developed plan view of an intermediate transfer belt for explaining the synchronization of the image forming operation. It is a see-through | perspective front view which shows the structure of the transfer side cleaner unit. FIG. 6 is a transparent front view showing a state when the surface of the intermediate transfer belt is cleaned by the transfer side cleaner unit. FIG. 6 is a transparent front view showing a state at the end of cleaning of the surface of the intermediate transfer belt by the transfer side cleaner unit. It is a figure which shows 2nd Embodiment of the image forming apparatus which concerns on this invention, and is a see-through | perspective front view which shows the structure of the transfer side cleaner unit. FIG. 6 is a transparent front view showing a state when the surface of the intermediate transfer belt is cleaned by the transfer side cleaner unit. FIG. 6 is a transparent front view showing a state at the end of cleaning of the surface of the intermediate transfer belt by the transfer side cleaner unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image recording device 11 ... Laser beam scanning device 12 ... Photoconductor drum 12a ... Conductive part 12b ... Photoconductor layer 12c ... Insulating part 13 ... Charger 14 ... Developing cartridge 14a ... Developing roller 15... Developing rotary unit 16... Intermediate transfer belt 16 a... Belt body 16 b .. Resistor layer 16 c... Conductive layer 16 d .. Electrode portion 16 e. Development side cleaner unit 19a, 21a ... Cleaner blade 19b, 82 ... Seal member 21 ... Transfer side cleaner unit 27 ... Patch sensor 28 ... Power supply 29 ... Proximity sensor 30 ... Paper transport device 31 ... … Paper cassette 32 …… Pickup roller 34 …… Registration roller pair 37 …… Intermediate transport roller pair 38 …… Feeding roller La pair 39 …… Discharge table 40 …… Control unit 41 …… Controller unit 42 …… CPU 46 …… Engine control unit 51 …… Electrode roller 52 …… Primary transfer roller 53 …… Backup roller 61 …… Blade support member 61a, 62a ... rotating shaft 62 ... seal support member 63 ... cleaner housing 63a, 63b ... sponge material 63c ... conveying screw 81 ... film member 81a, 82a ... bent part 82b ... sliding contact part 83 ...... Slab members

Claims (3)

A first carrier for carrying a toner image obtained by developing an electrostatic latent image based on image data; and a second carrier for secondary transfer of a toner image received by primary transfer from the surface of the first carrier to a recording medium; A cleaner unit that is disposed for each of these carriers and collects residual toner on the surface of the carrier, and transfers the toner image on the surface of the first carrier to the recording medium via the second carrier. In an image forming apparatus that forms an image by fixing the
The cleaner unit of the second carrier comprises a cleaner housing that collects residual toner on the surface of the second carrier, a cleaner blade that slidably contacts the surface of the second carrier and scrapes and removes toner remaining after the transfer of the toner image, And a seal that slidably contacts the surface of the second carrier to define the cleaner housing as a closed space together with the cleaner blade, and the cleaner blade and the seal come into contact with and separate from the surface of the second carrier at a preset timing. An image forming apparatus that operates to pass or collect toner on the surface of the second carrier to thereby form a desired toner image on the surface of the second carrier,
A conductive layer formed so as to spread over the entire surface of the second carrier surface, and a peripheral end at a side of the second carrier surface with respect to the rotation direction so as to be able to supply power from the power source of the apparatus body through the conductive layer. The toner removed from the surface of the second carrier is moved to the vicinity of the surface of the second carrier on the upstream side of the cleaner blade with respect to the rotation direction of the surface of the second carrier. An electric field generating means for generating an electric field,
The electric field generating means has one set or two or more sets of opposing members that generate an electric field by applying a potential difference on the upstream side of the cleaner blade with respect to the rotation direction of the surface of the second carrier. Receives a voltage fed from the power supply of the apparatus main body to the second carrier, and generates an electric field that attracts toner into the cleaner housing by applying a potential difference to the other of the opposing members. An image forming apparatus.   The image forming apparatus according to claim 1, wherein one of the opposing members is configured by a seal that comes into contact with the surface of the second carrier and is in sliding contact with the electrode portion. The seal that constitutes one of the opposing members bends inward of the cleaner housing, whereas the other of the opposing members is supported by the cleaner blade that is separated from and abutted against the surface of the second carrier, while the inner side of the cleaner housing. The image forming apparatus according to claim 2, wherein the image forming apparatus extends to face the seal.

Images