JP2007101990A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which is capable of quick processing without pollution in an apparatus main body by preventing the occurrence of a pressure difference between the inside and the outside of a cleaner housing to avoid blowout of floating toner of large quantities of toner clouds from the cleaner housing when separating a cleaner blade or a seal from an image carrier surface. <P>SOLUTION: In the image forming apparatus wherein a toner image formed on a surface of a photoreceptor drum is transferred to a recording paper through an intermediate transfer belt 16 and the cleaner blade 22 and a seal member 23 are separated from and brought into contact with a surface of the intermediate transfer belt to scrape off/recover toner remaining on the surface so as to prevent leakage of the toner to the outside, air holes 65 and 67 are opened in a seal support member 62 defining a cleaner housing 63 and a blade support member 61 and are closed with air-permeable film materials 66 and 68, and the seal member 23 is made of an air-permeable film material. <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. As shown in FIG. 7, the cleaner blade is disposed on the surface of the second carrier so that, for example, when forming a color image, the toner image is superimposed and transferred to a recording medium. After the 22 and the seal member 23 are separated from the surface of the second carrier 16, the surface of the second carrier 16 is rotated by sliding in the direction of the arrow in FIG. The toner remaining in the toner is scraped off in the cleaner housing 63 (scraped in the direction indicated by the broken arrow in FIG. 7) and removed and collected (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. In addition, when a so-called patch sensor detection unit that is disposed to maintain the image with high quality and detects the density of the toner image is contaminated, the image quality deteriorates.

  Therefore, the present invention prevents a large amount of toner cloud floating toner from being ejected from the cleaner housing when the cleaner blade and the seal are separated from the surface of the carrier by preventing the pressure difference between the inside and outside of the cleaner housing from occurring. An object of the present invention is to provide an image forming apparatus that can avoid the contamination and can perform high-speed processing without contamination in the apparatus main body.

  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 in a manner to form a desired toner image on the surface of the second carrier, wherein a housing defining member that defines a cleaner housing is separated from and abutted against a counterpart member so that the cleaner housing can be opened and closed. It is provided with a member, and is designed to be able to always ventilate between the inside and outside communication / blocking regions of the cleaner housing by opening and closing the separation contact member.

  In this invention, the area where the inside and outside of the cleaner housing are communicated and cut off due to separation and contact between the housing defining members is always in a vented state, and a pressure difference between the inside of the cleaner housing and the adjacent external area is prevented. Is done. As a result, even if the separation contact member communicates with the outside, the air in the cleaner housing can be prevented from being blown out, and the floating toner in the toner cloud generated when the cleaner blade is in sliding contact with the surface of the second carrier is prevented. It is possible to prevent leakage to the outside along with the jetted air. Accordingly, it is possible to prevent a large amount of floating toner from leaking out of the cleaner housing and contaminating surrounding members. Here, in the above-mentioned document 1, as shown in FIG. 7, the vent hole H is opened on the back side of the cleaner housing 63 (opposite side opposite to the cleaner blade 22). Since it does not correspond to the area where the inside and outside communicate / block (cleaner blade 22 or seal member 23), it is impossible to eliminate the pressure difference between inside and outside. I couldn't prevent it.

  According to a second aspect of the image forming apparatus for solving the above problem, in addition to the specific matters of the first aspect, air is passed through a support member that rotatably supports a seal or a cleaner blade while forming the housing defining member. A hole is opened.

  In the present invention, a ventilation hole is opened in a support member that rotates while supporting a seal or cleaner blade that comes into contact with and separates from the surface of the second carrier, thereby providing air permeability. Thereby, it is avoided that a pressure difference arises inside and outside a seal support member or a blade support member. In addition, when the support member of the seal or the cleaner blade is rotated, the capacity of the cleaner housing has been instantaneously changed in the past, but the air in the cleaner housing is effectively released from the vent hole of the support member. And the occurrence of instantaneous pressure fluctuations in the cleaner housing can be avoided. Therefore, when the seal or the cleaner blade is separated from the surface of the second carrier, the air in the cleaner housing or the floating toner in the toner cloud is prevented from being ejected to the outside, and a large amount of floating toner leaks from the cleaner housing. It is possible to prevent the surrounding members from being contaminated.

  In addition to the specific matters of the second invention, the third invention of the image forming apparatus that solves the above problem captures the toner floating in the cleaner housing in the vent hole or in the middle of the flow path communicating with the vent hole. It is characterized in that a possible filter is installed.

  In the present invention, the floating toner discharged from the vent hole is captured by the filter. Therefore, it is possible to prevent floating toner from leaking out of the cleaner housing and contaminating surrounding members.

  According to a fourth aspect of the image forming apparatus for solving the above-mentioned problems, in addition to the specific matters of the first aspect, the housing defining member allows the air to pass while restricting the passage of the toner floating in the cleaner housing. It is made of a material.

  In the present invention, the passage of the toner is restricted while the passage of the toner is restricted by the housing defining member in the region where the inside and outside of the cleaner housing are communicated and blocked. Thereby, it is possible to avoid the occurrence of a pressure difference between the inside and outside of the housing defining member that comes in contact with and separates. Therefore, the air in the cleaner housing can be prevented from being blown out even when communicating with the outside by the operation of the separation contact member, and the floating toner in the toner cloud generated when the cleaner blade is in sliding contact with the surface of the second carrier. Can be prevented from leaking to the outside together with the air that is ejected.

  In a fifth invention of an image forming apparatus that solves the above problem, in addition to the specific matters of the fourth invention, the seal constituting the housing defining member restricts the passage of the toner floating in the cleaner housing. It is made of a material that allows ventilation.

  In the present invention, the seal that comes into contact with and separates from the surface of the second carrier secures ventilation between the inside and outside of the cleaner housing and restricts the passage of toner. This avoids a pressure difference between the inside and outside in the vicinity of the seal. Therefore, even if the seal is separated from the surface of the second carrier and communicates with the outside, it is possible to avoid the air in the cleaner housing from being blown out, and the toner generated when the cleaner blade comes into sliding contact with the surface of the second carrier. It is possible to prevent the floating toner in the cloud from leaking out together with the air that is ejected.

  As described above, according to the present invention, it is possible to prevent a pressure difference from being generated in the area where the inside and the outside of the cleaner housing are communicated / blocked. For example, even if the seal or the cleaner blade is separated from the surface of the second carrier, the second It is possible to prevent the toner cloud (floating toner) in the cleaner housing that is generated when the cleaner blade is in sliding contact with the surface of the carrier from being ejected together with the air in the cleaner housing. It is possible to prevent leakage and contamination of surrounding members such as an image forming area on the surface of the second carrier to which toner is transferred. Therefore, it can be avoided that the quality of the toner image is deteriorated or 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 5 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 22, and an outer peripheral surface side of the developing rotary unit 15. In particular, the exhaust fan 24a, 24b disposed so as to cover the exhaust fan 24a, 24b, the toner that scatters to the surroundings when the suction fan F sucks the downstream side in the rotation direction of the photosensitive drum 12 (developing roller 14a) in particular. And an exhaust unit 26 that collects with a filter 25 interposed between 24b.

  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 for sequentially forming and forming monochrome images on recording paper by switching the developing cartridge 14 for developing the image.

  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. . Since the intermediate transfer belt 16 is pressed from the back side to the primary transfer roller 52 and presses against the photosensitive drum 12, the photosensitive drum 12 has an electrode portion 16d exposed on the side of the intermediate transfer belt 16. If the photosensitive layer 12b is in contact with the photosensitive layer 12b on the surface of the conductive portion 12a and a pinhole or the like exists in the photosensitive layer 12b, current leakage may occur between the originally insulated intermediate transfer belt 16. Therefore, the 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 reflective photosensor is arranged so that the detection portion faces the intermediate transfer belt 16 at a portion wound around the backup roller (pulley) 53 on the side separated from the transfer roller 17. The CPU 42 of the engine control unit 46 emits light toward the transfer surface (toner image) on the surface of the intermediate transfer belt 16 and is connected to the engine control unit 46 of the control unit 40. The density of the toner image (toner image on the intermediate transfer belt 16) formed on the photosensitive drum 12 by the developing cartridge 14 based on the detection signal from the patch sensor 27 obtained by photoelectrically converting the reflected light from the toner image of the toner image (covering with toner) Rate) 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 the density detection has been completed is scraped and collected by the cleaner blade 22 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). The CPU 42 of the engine control unit 46 is driven and controlled to operate so as to allow patrol without scraping until transfer. That is, in the transfer side cleaner unit 21, the cleaner blade 22 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 23 also comes into contact with (slidably contacts with) the surface of the intermediate transfer belt 16 upstream of the cleaner blade 22 to close the recovery space of the cleaner housing 63. Even when the monochrome image is continuously formed, the cleaner blade 22 and the seal member 23 are separated from the surface of the intermediate transfer belt 16 and come into contact with the surface of the intermediate transfer belt 16 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 22 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 22 and the seal member 23 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 the time when the cleaner blade 22 and the seal member 23 come into contact with the surface of the intermediate transfer belt 16 to scrape the residual toner and the time when the residual toner is settled. As a result, if there is no time for switching between the various operations and sufficient time cannot be secured, the toner blade of the floating toner that has been sprinkled by the sliding contact of the cleaner blade 22 is settled before the cleaner blade 22 or the seal is settled. As the member 23 moves away from the surface of the intermediate transfer belt 16, an instantaneous pressure increase due to rotation of the cleaner blade 22 and the seal member 23 toward the cleaner housing 63 occurs, and the air flow is ejected to the outside. As a result, floating toner leaks out of the cleaner housing 63. There is a Les. 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.

  Therefore, the transfer side cleaner unit 21 includes an inner and outer portion of the cleaner housing 63 in which toner cloud (floating toner) generated by the residual toner on the surface scooping up when the cleaner blade 22 is brought into sliding contact with the surface of the intermediate transfer belt 16. Therefore, even if the cleaner blade 22 and the seal member 23 are separated from the surface of the intermediate transfer belt 16, the residual toner on the surface of the intermediate transfer belt 16 is surely removed and collected. A function for preventing a large amount of cloud floating toner from leaking out of the cleaner housing 63 is added.

  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 22, and a seal member 23. 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 22 so that the tip end portion can freely swing, and the tip end corner portion 22 a of the cleaner blade 22 is attached to the surface of the intermediate transfer belt 16. It is pivotally supported by a rotation shaft (not shown) so as to be rotated in the direction of contact or separation. The cleaner blade 22 is slid in such a posture that the front end corner portion 22a abuts against the rotation of the intermediate transfer belt 16 wound around the backup roller 53 with respect to the surface below the leftmost end surface in FIG. By touching, when the residual toner on the surface of the intermediate transfer belt 16 is scraped off, it is lifted to generate a toner cloud.

  Similarly, the seal support member 62 is attached and supported on the proximal end side of the seal member 23 so that the distal end side can freely swing. Similarly to the blade support member 61, the distal end side of the seal member 23 is supported. The intermediate transfer belt 16 that is wound around the backup roller 53 is rotated from the vicinity of the leftmost end surface in FIG. It is pivotally supported by a rotating shaft.

  The cleaner housing 63 is arranged on the side where the residual toner scraped off by the cleaner blade 22 from the surface of the intermediate transfer belt 16 spills down and defines a recovery space for the residual toner. For example, an elastically deformable sponge material or the like is interposed between the blade support member 61 that supports the seal member 22 and the seal support member 62 that supports the seal member 23, so that regardless of these rotational operations. The gap where the collected toner leaks is filled. That is, the blade support member 61 and the seal support member 62 constitute a part of a housing defining member 63 a that defines the cleaner housing 63. 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. The conveyance screw which conveys to etc. is arrange | positioned.

  Here, near the surface of the intermediate transfer belt 16, a rotating airflow is generated due to the rotation of the surface, and most of the airflow flows on the upper surface of the seal support member 62. The part tends to pressurize the internal pressure to make the internal pressure positive by entering the cleaner housing 63 so as to push up the seal member 23 together with the residual toner on the surface of the intermediate transfer belt 16.

  Therefore, in this transfer side cleaner unit 21, the cleaner blade 22, the seal member 23, the blade support member 61, and the seal support member 62 constitute a part of the housing defining member 63 a that defines the outer surface of the cleaner housing 63. However, the seal member 23 restricts the passage of the toner floating in the cleaner housing 63 and allows the air inside and outside the cleaner housing 63 to pass (vent). It is manufactured by Nitto Denko Co., Ltd. Microtex (registered trademark).

  As a result, the airflow that has been dragged to the surface of the intermediate transfer belt 16 and has entered the cleaner housing 63 beyond the sliding contact position with the seal member 23 has conventionally acted to increase the internal pressure in the cleaner housing 63. However, here, the floating toner of the toner cloud generated in the cleaner housing 63 can flow out from the seal member 23 without passing through, and a pressure difference is not generated between the inside and the outside of the cleaner housing 63. The internal pressure will not increase.

  Accordingly, since the cleaner blade 22 and the seal member 23 are separated from the surface of the intermediate transfer belt 16 and the inside of the cleaner housing 63 communicates with the outside, the clearance between the surface of the intermediate transfer belt 16 and the seal member 23 and the like can be increased. It can be avoided that a large amount of toner cloud (floating toner) is ejected together with the air to contaminate the outside of the apparatus. Even if the seal support member 62 and the blade support member 61 are rotated to reduce the volume in the cleaner housing 63 in order to separate the seal member 23 and the cleaner blade 22 from the surface of the intermediate transfer belt 16, the cleaner Since the inside of the housing 63 is not in a pressurized state, it is possible to avoid an extreme pressure fluctuation from occurring instantaneously, and the pressure rise due to the pressure fluctuation causes the seal member 23 and the cleaner from the surface of the intermediate transfer belt 16. It is possible to reduce the occurrence of air and toner cloud (floating toner) in the cleaner housing 63 being ejected from the gap where the blades 22 are separated.

  As described above, in this embodiment, the floating toner in the toner cloud in the cleaner housing 63 generated when the cleaner blade 22 is brought into sliding contact with the surface of the intermediate transfer belt 16 causes the cleaner blade 22 and the seal member 23 to be on the surface of the intermediate transfer belt 16. It is possible to prevent a large amount from being ejected when being separated from the container. Accordingly, the floating toner does not adhere to and contaminate each part of the surrounding apparatus. For example, the toner density becomes undetectable by adhering to the detection part of the patch sensor 27, and the intermediate transfer By causing color mixture by adhering and remaining in the image forming area of the belt 16, image quality is deteriorated, and floating toner adheres around the transfer side cleaner unit 21, which makes maintenance work difficult. You can avoid that.

Next, FIG. 6 is a diagram showing a second embodiment of the image forming apparatus according to the present invention.
6, in the transfer side cleaner unit 21 of this image forming apparatus, a vent hole 65 extending in the width direction of the intermediate transfer belt 16 is opened in a seal support member (housing defining member) 62 that supports the seal member 23. Similarly to the seal member 23, the air holes 65 restrict the passage of toner floating in the cleaner housing 63 and allow air inside and outside the cleaner housing 63 to pass (vent). An acceptable breathable film material 66 is affixed.

  Similarly, a blade support member (housing defining member) 61 that supports the cleaner blade 22 has a vent hole 67 that extends in the width direction of the intermediate transfer belt 16. A ventilation film material 68 that restricts the passage of the floating toner in the cleaner housing 63 and allows the air inside and outside the cleaner housing 63 to pass (vent) is attached.

  Here, on the installation location side (region 2) of the blade support member 61, the exhaust duct 24a serving as the suction port of the exhaust unit 26 opens in the vicinity, so that the pressure difference with respect to the cleaner housing 63 (region 1) is different. The region 2 outside the region 1 in the cleaner housing 63 tends to be depressurized and is in a negative pressure state. Similarly, on the installation location side (region 3) of the seal support member 62, the suction by the exhaust duct 24a of the exhaust unit 26 is affected and a pressure difference is easily generated in the cleaner housing 63 (region 1). The region 3 outside the region 1 in the cleaner housing 63 tends to be decompressed and may be in a negative pressure state.

  As a result, in the transfer side cleaner unit 21, the vent holes 65 and 67 are opened in the seal support member 62 and the blade support member 61 and closed by the vent film material 66 and 68. The air flow between the region 1 and the regions 2 and 3 is allowed without passing the floating toner of the toner cloud to be passed, and the pressure difference is prevented from being generated. Further, the vent holes 65 and 67 have the seal support member 62 and the blade support member 61 so as to reduce the volume in the cleaner housing 63 in order to separate the seal member 23 and the cleaner blade 22 from the surface of the intermediate transfer belt 16. Even if the rotation is caused, the air in the cleaner housing 63 can be effectively passed (released), so that a large pressure fluctuation can be avoided from occurring instantaneously. The air in the cleaner housing 63 and the toner cloud (floating toner) can be less likely to be ejected from the gap where the seal member 23 and the cleaner blade 22 are separated from the surface of the belt 16.

  As described above, in the present embodiment, in addition to the operational effects of the first embodiment, in the installation regions 1 and 3 of the seal member 23, the air permeability can be further improved, and the installation region 1 of the cleaner blade 22 can be improved. 2, air permeability can be ensured, so that the floating toner in the toner cloud generated by the sliding contact of the cleaner blade 22 with the surface of the intermediate transfer belt 16 is removed from the intermediate transfer belt 16 by the cleaner blade 22 and the seal member 23. It can prevent more reliably that it ejects when separating. Therefore, it is possible to more reliably avoid the deterioration of image quality and the maintenance workability caused by the floating toner in the cleaner housing 63 leaking to the outside.

  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 having an intermediate transfer belt will be described as an example. However, it is needless to say that the apparatus is not limited to this, and an apparatus having a roller-shaped member as a member for carrying toner is also used. It can be applied and the same effect can be obtained.

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. 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. 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. It is a figure which shows the prior art, and is a see-through | perspective front view which shows the structure of the transfer side cleaner unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image recording device 11 ... Laser beam scanning device 12 ... Photosensitive drum 13 ... Charger 14 ... Developing cartridge 14a ... Developing roller 15 ... Developing rotary unit 16 ... Intermediate transfer belt 16e ... Projection Piece 17: Transfer roller 18: Fixing roller pair 19: Development side cleaner unit 19a, 22 ... Cleaner blade 19b, 23 ... Seal member 21 ... Transfer side cleaner unit 22a ... Tip corner 24a, 24b ... ... Exhaust duct 25 ... Filter 26 ... Exhaust unit 27 ... Patch sensor 29 ... Proximity sensor 30 ... Paper transport device 31 ... Paper cassette 32 ... Pickup roller 34 ... Registration roller pair 37 ... Intermediate transport roller 38 ... Feeding roller pair 39 ... Discharge table 40 ... Control unit 41 ... Controller unit 42... CPU 46... Engine control unit 61... Blade support member 62... Seal support member 63... Cleaner housing 63a .. Housing defining member 65 and 67. material

Claims (5)

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 carrier and collects residual toner on the surface of the carrier, and transfers the toner image on the surface of the first carrier to a 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 housing defining member that defines the cleaner housing includes a member that contacts and separates from the counterpart member so that the cleaner housing can be freely opened and closed;
An image forming apparatus characterized by being designed so as to be able to always ventilate between the inside and outside communication / blocking regions of the cleaner housing by opening and closing of the separation contact member.   The image forming apparatus according to claim 1, wherein a ventilation hole is opened in a support member that rotatably supports a seal or a cleaner blade while forming the housing defining member.   The image forming apparatus according to claim 2, wherein a filter capable of trapping toner floating in the cleaner housing is installed in the vent hole or in the middle of the flow path communicating with the vent hole.   The image forming apparatus according to claim 1, wherein the housing defining member is made of a material that allows ventilation while restricting passage of toner floating in the cleaner housing. The image forming apparatus according to claim 4, wherein the seal constituting the housing defining member is made of a material that allows air to pass while restricting passage of toner floating in the cleaner housing.

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