JP2010156859A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform an automatic seal pull while preventing turning-up of a cleaning blade by efficiently carrying powder applied on a developer supply member to the cleaning blade, in an image forming device to which a process cartridge detachably installed and which forms an image in a recording medium. <P>SOLUTION: At the time of an operation start of this image forming device wherein an image carrier 1, a developer carrier 44, the developer supply member 45, and a seal member unsealing means 55 are driven by the same drive source M1 and wherein the cartridge 50 in a seal member unsealing state is installed to an image forming device body 100B, the drive source M1 is driven at a first drive speed at which a prescribed amount of the powder is carried to the image carrier 1, and is driven at a second drive speed faster than the first drive speed after a prescribed time. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus in which a process cartridge is detachable and forms an image on a recording medium.

  Here, the image forming apparatus includes, for example, a copying machine / printer (for example, an LED printer, a laser beam printer, etc.), a facsimile apparatus, and the like, such as an electrophotographic system, an electrostatic recording system, and a magnetic recording system.

  The image carrier is a member on which a latent image (an electrostatic latent image, a potential latent image, a resistance latent image, a magnetic latent image, etc.) to be developed with a developer is formed. Examples thereof include an electrophotographic photosensitive member (photoconductor) in an electrophotographic process, an electrostatic recording dielectric in an electrostatic recording process, and a magnetic recording magnetic body in a magnetic recording process.

  Conventionally, for example, a process cartridge system is known in an electrophotographic image forming apparatus. This is a process cartridge in which an electrophotographic photosensitive drum (hereinafter referred to as a drum) as an image carrier and at least a developing device (developing unit) of process means acting on the drum are integrated. Then, it is used by being detachably mounted on the image forming apparatus main body.

  According to the cartridge system, the maintenance of the apparatus can be performed by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. For this reason, the cartridge system is widely used in electrophotographic image forming apparatuses.

  The developing device in the cartridge includes a developing frame (developing device) that holds a developing roller or the like as a rotatable developer carrying member that develops the latent image formed on the drum with the developer, and a developer that contains the developer. A frame (hopper) is coupled. In the developing unit in a new cartridge before use, which is shipped from the factory, an opening provided at a coupling portion between the developing frame and the developer frame is sealed with a seal member. As a result, the developer contained in the developer frame is prevented from moving toward the development frame, and the developer leakage during the cartridge distribution process is prevented.

Patent Document 1 proposes a so-called automatic seal pulling configuration. In this case, the unopened cartridge of the seal member is attached to the main body of the image forming apparatus. Then, the seal member is wound on the seal take-up member with the driving force transmitted from the main body of the image forming apparatus to the developing device in the developer container, the process cartridge, or the developing cartridge. Thus, the seal member is wound inside and opened without taking it out.
JP 2000-235301 A

  In recent years, in order to cope with downsizing and cost reduction of image forming apparatuses, driving sources for the drum and the developing apparatus are unified. Further, in order to reduce the unnecessary rotation of the developing roller in order to cope with the long life of the developing device, the drive transmission to the developing device is performed only during the development to the drum.

  Therefore, if the automatic seal pulling is performed under the configuration in which the drum, the developing roller, and the seal pulling are driven at the same time and the driving to the developing device is performed only during development, the following situation may occur. That is, when the cartridge is inserted into the main body of the image forming apparatus and the seal pulling operation is performed, the drum rotates without the toner acting as a lubricant until the seal is opened. As a result, it is conceivable that the cleaning blade is turned over during the pulling of the seal.

  In general, the cleaning blade is prevented from being turned over by applying a coating agent to the cleaning blade. However, applying such a coating agent causes a decrease in productivity. Further, if the amount of the coating agent is small, turning-up during automatic sealing may occur, and if the amount of the coating agent is too large, charging failure may occur due to peeling of the coating agent, and it is not preferable to apply the coating agent.

  Therefore, in order to prevent the cleaning blade from being turned over during automatic sealing, the following measures are effective. That is, the powder initially applied to reduce the initial torque of the toner supply roller as a developer supply member with respect to the development roller as the developer carrying member is sent to the cleaning as a lubricant immediately after the start of the automatic seal pulling operation. It is effective.

  In order to sufficiently convey the powder to the cleaning blade, there is a means for increasing the initial application amount to the toner supply roller and increasing the amount of powder sent to the cleaning blade. However, increasing the initial coating amount on the toner supply roller is not preferable because it reduces productivity.

  The present invention is a further development of the prior art. An object of the present invention is to prevent the cleaning blade from being turned over by efficiently conveying the powder applied to the developer supply member to the cleaning blade, and to perform automatic sealing.

A typical configuration of the image forming apparatus according to the present invention for achieving the above object is as follows:
An image forming apparatus for forming an image on a recording medium,
At least a rotatable image carrier on which a latent image is formed, a rotatable developer carrier for developing the latent image by transporting the developer to the image carrier, and a lubricant in advance A developer supply member that can be rotated to supply the developer to the developer carrying member, a developer storage container that stores the developer, and a developer in the developer storage container. An opening for feeding to the developer supply member; a seal member for sealing the opening; a seal member opening means for receiving the drive to open the seal member; and a tip portion with respect to the image carrier A cartridge having a cleaning blade that is in contact with the counter with respect to the rotation direction of the image carrier, and is detachably attached to the main body of the image forming apparatus.
The image carrier, the developer carrier, the developer supply member, and the seal member opening means have the same drive source,
When the cartridge in an unopened seal member is mounted on the main body of the image forming apparatus, when the operation of the image forming apparatus is started, the drive source supplies the powder to the image carrier by a predetermined amount. And a second driving speed higher than the first driving speed after a predetermined time.

  According to the present invention, even when a new process cartridge with an unopened seal member is inserted into the apparatus main body and automatic sealing is performed, powder serving as a lubricant can be conveyed to the cleaning blade. Turn over can be prevented.

  In addition, by switching to the second driving speed, it is possible to shorten the sticking time.

"Example"
(1) Image Forming Unit FIG. 1 is a schematic configuration diagram of an image forming apparatus 100 according to the present embodiment. The image forming apparatus 100 according to the present exemplary embodiment applies a series of electrophotographic image forming processes of charging, exposure, development, transfer, and cleaning to a rotatable electrophotographic photosensitive member as an image carrier. This is an electrophotographic laser beam printer that forms an image. Further, a cartridge system in which a process cartridge 50 having an automatic seal pulling mechanism (automatic opening mechanism) is detachably mounted on a cartridge mounting portion 100B in an image forming apparatus main body (hereinafter referred to as an apparatus main body) 100A. Printer.

  That is, an image corresponding to an electrical image signal input to a control circuit unit (control means: engine controller) 101 of the image forming apparatus 100 from an external host device 200 such as a personal computer is formed on a recording medium. The control circuit unit 101 exchanges various types of information with the external host device 200, and comprehensively controls all operation sequences of the image forming apparatus according to a predetermined control program and a reference table. The recording medium is capable of forming an image such as a recording paper, an OHP sheet, or a cloth. The recording medium may be an intermediate transfer member such as an intermediate transfer drum or an intermediate transfer belt.

  In the following description, with respect to the image forming apparatus 100, the front side or the front side is the side on which the front door 102 that is an opening / closing member for opening and closing the apparatus is disposed. The rear side is the opposite side. The front-rear direction is a direction from the rear side to the front side of the image forming apparatus (front direction) and the opposite direction (rear direction). Left and right are left or right when the image forming apparatus is viewed from the front side. The left-right direction is a direction from left to right (left direction) and the opposite direction (right direction). The apparatus main body 100A is an image forming apparatus portion excluding a process cartridge (hereinafter referred to as a cartridge) 50.

  In this embodiment, the process means for executing the series of electrophotographic image forming processes includes a drum-type electrophotographic photosensitive member (hereinafter referred to as a drum) 1 and contact charging which is a charging means for charging the drum 1. The member 2 is included. The image exposure apparatus 3 is an image exposure unit that forms an electrostatic latent image by exposing the surface of the charged drum 1 to an image. Further, the electrostatic latent image is developed with a developer (hereinafter referred to as “toner”), and a developing device (developing unit) 4 that is a developing unit that visualizes the toner image as a toner image, and the toner image is transferred to the recording medium P. A transfer roller 5 which is a transfer unit is included. Further, it includes a cleaning device 6 which is a cleaning means for cleaning the surface of the drum 1 after transfer.

  In this embodiment, the cartridge 50 unitizes the drum 1, the contact charging member 2, the developing device 4, and the cleaning device 6 out of the above process means. These components are assembled in a predetermined mutual relationship within the cartridge. Details of the cartridge 50 will be described later.

  In the image forming apparatus of this embodiment, the attachment / detachment operation of the cartridge 50 with respect to the apparatus main body 100A is performed by front access. That is, the front door 102 is opened almost horizontally to the front side of the apparatus main body 100A as indicated by a two-dot chain line with the hinge 103 on the lower side as the center. As a result, the front opening of the apparatus main body 100A is opened. Therefore, the cartridge 50 is inserted rearward into the apparatus main body from the front opening and is attached to the attachment portion 100B. The cartridge 50 is mounted on the mounting portion 100B with the drum 1 side facing forward. Conversely, the cartridge 50 attached to the attachment portion 100B is pulled forward and taken out of the apparatus body from the front opening. The cartridge 50 is guided by engagement between a guide member (not shown) on the apparatus main body side and a guided portion (not shown) on the cartridge side, and is inserted into and removed from the mounting portion 100B. The image forming apparatus 100 is in a state in which an image forming operation is possible when the cartridge 50 is inserted into the mounting portion 100B in a predetermined manner and the front door 102 is closed.

  The drum 1 is rotationally driven at a predetermined peripheral speed (process speed) in the clockwise direction of an arrow at a predetermined control timing of the operation sequence control of the image forming apparatus.

  The contact charging member 2 is a member that contacts the surface of the drum 1 and charges the drum surface. In this embodiment, the contact charging member 2 is a conductive roller (hereinafter referred to as a charging roller) disposed in contact with the drum 1, and rotates in the counterclockwise direction of the arrow following the rotation of the drum 1. A predetermined charging bias is applied to the charging roller 2 from the power supply unit on the apparatus main body side. As a result, the surface of the rotating drum 1 is uniformly charged to a predetermined polarity / potential (dark portion potential Vd). In this embodiment, a negatively charged charging bias having a predetermined potential is applied to the charging roller 2, and the drum surface is uniformly charged to a predetermined negative potential Vd. In this embodiment, Vd is −400V.

  In this embodiment, the image exposure apparatus 3 is a laser beam scanner unit including a laser / polygon mirror / lens system. The image exposure device 3 scans and outputs a laser beam L modulated in accordance with an image signal, and the surface of the drum uniformly charged by the charging roller 2 is subjected to laser beam scanning exposure. By this exposure, the surface potential of the exposed portion of the drum surface is attenuated to the bright portion potential Vl: −100V in this embodiment, and corresponds to the image exposure pattern on the drum surface with the electrostatic contrast with the dark portion potential Vd: −400V. An electrostatic latent image is formed.

  The electrostatic latent image is developed as a toner image by the developing device 4. In this embodiment, the developing device 4 is a non-magnetic one-component contact developing system. This is a reversal developing device using toner having a negative polarity as a developer. That is, the toner adheres to the exposed portion of the drum surface and the electrostatic latent image is developed. Details of the developing device 4 will be described later.

  On the other hand, a sheet-like recording material P as a recording medium loaded and stored in the cassette 7 is separated and fed by a sheet feeding roller 8 driven at a predetermined control timing, and the belt 9a of the belt unit 9 is separated. Is electrostatically held by the substrate and conveyed upward. The belt 9a is a dielectric endless belt made of a dielectric material, and is suspended and stretched between a driving roller 9b and a driven roller 9c arranged in parallel in the vertical direction. The belt 9a is circulated and moved in the counterclockwise direction indicated by the arrow in the forward direction with respect to the rotation of the drum 1 and at a speed corresponding to the rotation speed of the drum 1 by the rotation of the driving roller 9b. The recording material P separated and fed from the cassette 7 is electrostatically attracted to the outer surface of the upper belt portion of the belt 9a at the portion of the lower driven roller 9c by the electrode roller 9d to which a voltage is applied. Along with the movement of 9a, it is conveyed upward. The transfer roller 5 is disposed inside the belt 9a, and is in pressure contact with the drum 1 with the ascending belt portion of the belt 9a interposed therebetween. A pressure contact portion between the belt 9 a and the drum 1 is a transfer nip portion T. The recording material P is held by the belt 9a and passes through the transfer nip T. While the recording material P passes through the transfer nip T, the transfer roller 5 has a predetermined transfer bias (a polarity opposite to the toner charging polarity (positive polarity in this embodiment)) from the power supply unit and a voltage having a predetermined potential. ) Is applied. As a result, the toner image formed on the drum surface is sequentially electrostatically transferred onto the surface of the recording material P.

  The recording material P exiting the transfer nip T is continuously held by the belt 9a and conveyed upward, separated from the surface of the belt 9a at the portion of the driving roller 9b, and introduced into the fixing device 10. The fixing device 10 is, for example, a heat roller type fixing device, and the recording material P is nipped and conveyed by a fixing nip portion formed by the fixing roller 10a and the pressure roller 10b, whereby unfixed toner by heat and pressure. The image is fixed as a fixed image on the recording material. Then, the recording material P on which the image is fixed is discharged to the discharge unit 12 outside the apparatus by the discharge roller pair 11a and 11b.

  Further, the transfer residual toner remaining on the drum 1 after separation of the recording material is removed by the cleaning device 6. The drum 1 whose surface is cleaned by the cleaning device 6 is repeatedly used for image formation.

  The cassette 7 is a front loading system, and is inserted / removed (inserted / removed) from the front side of the apparatus main body 100A. The belt unit 9 is disposed integrally with the front door inside the front door 102 and moves together with the front door 102 relative to the apparatus main body 100A.

(2) Cartridge 50
As the cartridge 50 is used for image formation, the toner contained in the developing device 4 is consumed. When the toner is consumed to such an extent that an image with satisfactory quality cannot be formed for the user who purchased the cartridge, the commercial value of the cartridge is lost. Therefore, for example, a means for detecting the remaining amount of toner in the cartridge is provided. Then, in the control circuit unit 101, the detected remaining amount value is compared with a preset threshold value for warning or warning of the life of the cartridge. When the detected remaining amount value is smaller than the threshold value, the life warning or life warning of the cartridge 50 is displayed on the display unit 104a of the image forming apparatus or the display unit of the host device 200. Thus, the user is prompted to prepare a replacement cartridge or the cartridge is exchanged to maintain the quality of the output image.

  FIG. 2 is a schematic cross-sectional view of the seal member-new cartridge 50 before opening. In the cartridge 50 of this embodiment, the drum 1, the charging roller 2, the developing device 4, and the cleaning device 6 are unitized. These components are assembled in a predetermined mutual relationship within the cartridge. More specifically, in the cartridge 50, the drum unit 51 in which the drum 1, the charging roller 2, and the cleaning device 6 are assembled, and the developing device 4 are slidably coupled. 3A is a perspective view of the cartridge 50, and FIG. 3B is an exploded perspective view of the drum unit 51 and the developing device 4 of the cartridge 50.

  In the drum unit 51, the drum 1 and the charging roller 2 are rotatably installed on the frame of the drum unit 51. The charging roller 2 is arranged in parallel with the drum 1 with a predetermined pressing force. In this embodiment, the cleaning device 6 is a blade type device using an elastic cleaning blade 6a as a cleaning member. The blade 6a is disposed in contact with the drum 1 with its tip end facing the counter with respect to the rotation direction of the drum 1 (image carrier rotation direction). The transfer residual toner on the drum surface is scraped off by the blade 6a and stored in a waste toner chamber (waste toner container) 6b. More specifically, the cleaning blade 6a is composed of a urethane rubber tip blade and a sheet metal, and is set so as to be in a counter direction with respect to the rotation direction of the drum 1 and to have a contact angle of 23 °. Yes.

  The entire developing device 4 has a suspended structure that is swingably supported with respect to the drum unit 51. That is, bearing holes 51a and 51a are provided on the left and right sides (driving side and non-driving side) of the drum unit 51 so as to face each other. Further, bearing holes 52a and 52a are provided to face bearing members 52 and 52 disposed on the left and right sides (driving side and non-driving side) of the developing device 4. A shaft 53 is inserted through the left bearing hole 51a of the drum unit 51 and the left bearing hole 52a of the developing device 4 in correspondence with each other. Further, the shaft 53 is inserted through the bearing hole 51a on the right side of the drum unit 51 and the bearing hole 52a on the right side of the developing device 4 in correspondence with each other. Thus, the developing device 4 is coupled to the drum unit 51 so as to be rotatable about the left and right shafts 53 as the swing center. In the single cartridge state (free state), the developing device 4 is urged to rotate about the shaft 53 by pressure springs 54 and 54 that are elastic members on the left and right with respect to the drum unit 51. The pressure springs 54 and 54 are stretched between the drum unit 51 and the developing device 4 on the left and right sides of the cartridge 50 and on the drum 1 and the developing roller 44 side with respect to the position of the shaft 53. That is, the developing roller 44 is brought into contact with the drum 1 with a predetermined pressing force by the rotational moment of the developing device 4 by the pressure springs 54 and 54.

  The developing device 4 is configured as a developing device in which a developing container (developing frame body, developing device) 41 and a developer storage container (developing frame body, hopper) 42 are welded or bonded together to be integrally joined. The developing container 41 has a developing chamber 43. In the developing chamber 43, a developing roller 44 as a rotatable developer carrying member that develops the latent image formed on the drum 1 with toner is installed at a position facing the drum 1. In the developing chamber 43, a supply roller 45 as a developer supply member that supplies toner to the developing roller 44 on the side opposite to the drum 1 side of the developing roller 44 is rotatably installed. The developing chamber 43 is provided with a developing blade 46 as a developer layer thickness regulating member that regulates the amount of toner held on the developing roller 44 in contact with the developing roller 44. The base of the developing blade 46 is fixed to the developing container 41. The front end side is downstream of the developing roller 44 and the supply roller 45 in contact with the developing roller in the rotating direction of the developing roller, and the upstream side of the developing roller rotating position of the drum 1 and the developing roller 44 is opposed to the developing roller. It is elastically abutting against 44 by belly contact. The developing rollers 44 are arranged in parallel with the drum 1. The supply roller 45 is arranged in parallel with the developing roller 44 with a predetermined pressing force. The developing blade 46 is disposed along the length of the developing roller 44.

  The developer storage container 42 is a container that stores toner, has a toner chamber 47, and stores a predetermined initial amount of toner t. Further, a rotatable toner stirring / conveying member 62 for stirring and transporting the toner is disposed in the developer container 42.

  The developing chamber 43 and the toner chamber 47 are partitioned by a partition wall 49 having an opening 48 communicating with both chambers. The opening 48 is a horizontally long slit opening that extends in the axial direction of the developing roller 44. The opening 48 of a new cartridge 50 shipped from the factory is sealed (sealed) by a seal member (toner seal) 52. As a result, the toner t accommodated in the toner chamber 47 is kept sealed in the toner chamber 47, and the toner t is not present in the developing chamber 43. Toner leakage is prevented.

  The cartridge 50 of this embodiment includes an automatic seal pulling mechanism 55 as a seal member opening means for automatically opening the seal member 52. 4A and 4B are explanatory views of the automatic seal pulling mechanism 55. FIG. 4A is a view showing a state before the seal member-automatic opening, and FIG. 4B is a view showing a state after the seal member-automatic opening. . Referring to (a), the seal member 52 is thermally welded or bonded to the opening 48 of the partition wall 49 by hot melt or the like. In the sealing member 52, a sealing portion 52 a extending from the left end side to the right end side of the opening portion 48 is attached to the periphery of the opening portion 48, thereby sealing the opening portion 48. The right end side of the sealing part 52a is extended as an extension part 52c, and the extension part 52c is folded back toward the left end side with the right end part of the sealing part 52a being the folded part 52b. The tip 52d of the folded extension 52c is fixed to a take-up shaft 56 constituting an automatic seal pulling mechanism 55 disposed on the left side of the developer container 42. The take-up shaft 56 is a vertical axis member rotatably disposed on the left side of the developer storage container 42 via a bearing member (not shown). A drive input gear (bevel gear) 57 is fixed to the upper end portion of the winding shaft 56.

  As shown in FIG. 5, the cartridge 50 is mounted on the mounting portion 100B of the apparatus main body 100A with the seal member unopened. In this case, the drum unit 51 of the cartridge 50 is positioned and fixed to a positioning portion (not shown) of the mounting portion 100B and is attached to the mounting portion 100B. A memory tag (rewritable storage unit) 59 is provided at the front end side of the drum unit 51 in the cartridge insertion direction. A communication member 107 for reading / writing information from / to the memory tag 59 is disposed on the apparatus main body side. In a state where the cartridge 50 is mounted on the mounting portion 100B, the memory tag 59 is positioned to face the communication member 107. As a result, the control circuit unit 101 can read / write information from / to the memory tag 59 via the communication member 107.

  Further, the developing device 4 can swing around the shaft 53 with respect to the drum unit 51 positioned and fixed to the mounting portion 100B. In a state where the cartridge 50 is mounted on the mounting portion 100B in a predetermined manner, the drum gear 58 (FIG. 3) disposed on the left side of the drum 1 is engaged with the drum drive gear 106 on the apparatus main body side. In FIG. 3A, the arrow S indicates the direction in which the cartridge 50 is inserted into the apparatus main body 100A. In a state in which the cartridge 50 is sufficiently inserted into the apparatus main body 100A and is mounted in the mounting portion 100B, the drum gear 58 comes into contact with and engages with the drum drive gear 106 on the apparatus main body side. The drum driving gear 106 receives the driving force via a gear train (not shown) when the motor M1 (drive source) on the apparatus main body side is driven. The driving force is transmitted to the drum gear 58, so that the drum 1 rotates at a predetermined speed.

  A separation plate 105 as a force applying member (separation means) for the developing device 4 of the cartridge 50 installed in the mounting portion 100B is disposed on the back side in the apparatus main body 100A. The separation plate 105 is controlled to move up and down by a motor M2 (FIG. 1: stepping motor) driven and controlled by the control circuit unit 101. In the state of FIG. 5 in which the cartridge 50 is mounted on the mounting portion 100B of the apparatus main body 100A, the separation plate 105 in which the force receiving member 42a disposed at the lower portion on the distal end side in the insertion direction of the developing device 4 is located at the lowered position. It is located above. In this state, the developing device 4 is in a free state with respect to the drum unit 51. Therefore, the developing device 4 swings in the direction in which the developing roller 44 contacts the drum 1 on the drum unit 51 side with respect to the drum unit 51 around the shaft 53 due to the rotational moment by the pressure springs 54 and 54, and the developing roller 44. Is in contact with the drum 1 with a predetermined pressing force. The swing position of the developing device 4 is defined as a developing position.

  Further, when the separation plate 105 is moved to the raised position, the force receiving member 42a of the developing device 4 is pushed up. As a result, the developing device 4 is swung in the direction away from the drum 1 on the drum unit 51 side against the pulling force of the pressure springs 54 and 54 around the shaft 53 with respect to the drum unit 51. As shown in FIG. 6, the rocking position is maintained. The swing position of the developing device 4 is set as a separated position.

  In the state where the separation plate 105 is controlled to move downward and the developing device 4 is moved to the developing position, the developing gear 60 (FIG. 4) disposed on the right side of the developer container 42 of the developing device 4 is provided. The state is brought into contact with the developing drive gear 108 on the apparatus main body side. In the state where the separation plate 105 is controlled to move upward and the developing device 4 is moved to the separation position, the development gear 60 is separated from the development drive gear 108 and is disengaged.

  The development driving gear 108 receives the driving force of the motor M1 on the apparatus main body side via a gear train (not shown). The driving force is transmitted to the gear train 62 of the developing device 4 moved to the developing position. As a result, the developing roller 44 and the supply roller 45 in the developing container 41, the toner stirring and conveying member 62 in the developer container 42, and the winding shaft 56 of the automatic seal pulling mechanism 55 are driven to rotate at a predetermined speed. It has become.

  When the winding shaft 56 of the automatic seal pulling mechanism 55 is driven to rotate, the extension portion 50 c of the seal member 52 is wound around the winding shaft 56. Along with this winding, the sealing portion 52a sealing the opening 48 is sequentially peeled off from the opening 48 from the right end portion side toward the left end portion side. That is, the opening 48 is sequentially opened from the right end side toward the left end side. Finally, the sealing portion 50a of the seal member 50 is also wound around the take-up shaft 53, and the opening 48 is opened as a whole as shown in FIG. 4B. That is, the seal member 52 of the cartridge 50 is automatically opened.

  Then, as the toner stirring and conveying member 62 rotates, the toner t in the toner chamber 47 is supplied to the developing chamber 43 from the opened opening 48 as shown in FIG. Then, the toner in the developing chamber 43 is pressed against the surface of the developing roller 44 by the supply roller 45 and supplied. When the supplied toner enters and passes through the contact nip portion between the developing roller 44 and the developing blade 46, the layer thickness is regulated, and the toner is layered into a thin toner layer having a uniform thickness. Further, the toner is frictionally charged to a predetermined charging polarity. Then, the toner layer formed on the developing roller 44 by the subsequent rotation of the developing roller 44 is conveyed to a portion (developing portion) opposite to the drum 1 and the developing roller 44.

  At the time of image formation, predetermined biases are respectively applied to the charging roller 2, the developing roller 44, the supply roller 45, and the developing blade 46 from the power supply unit on the apparatus main body side. Then, the electrostatic latent image formed on the drum 1 is developed.

  In this embodiment, a photosensitive drum having a diameter of 30 mm is adopted as the drum 1. The drum 1 is rotated at a surface speed of 200 mm / sec in the clockwise direction indicated by an arrow A in FIG.

  The developing roller 44 is an elastic roller and is rotated in the counterclockwise direction indicated by an arrow B at a surface speed of 240 mm / sec, which is 120% of the rotational speed of the drum 1. In order to carry the toner (toner) satisfactorily, the surface has moderate irregularities. In the present embodiment, the developing roller 44 is made of an NBR rubber having a thickness of 5 mm and a surface roughness Rz of about 8 μm on a SUS core metal having a diameter of 6 mm. In this embodiment, Vdc: −300 V is applied to the developing roller 44 from a bias power source (not shown) during image formation.

  The supply roller 45 rotates at 192 mm / sec, which is 80% of the surface speed of the developing roller 44 in the counterclockwise direction of the arrow C (the direction in which the contact portion with the developing roller 44 moves in the opposite direction to the developing roller 44). Is done. The supply roller 45 of this embodiment uses a sponge roller having a diameter of 14 mm in which urethane foam is provided around a cylindrical body made of a metal such as aluminum, aluminum alloy, or stainless steel.

  The supply roller 45 is preliminarily coated with about 300 mg of powder as a lubricant, in this embodiment, the toner ta, in order to reduce torque during initial driving. In this embodiment, Vrs: −300 V is applied to the supply roller 45 from a bias power source (not shown) during image formation.

  The developing blade 46 as a developer layer thickness regulating member in this embodiment is composed of an elastic blade and a support sheet metal. The elastic blade uses a 100 μm thick SUS plate having a straight spring elasticity. In this embodiment, Vb: −400 V is applied to the developing blade 46 from a bias power source (not shown) during image formation.

(3) Initial Application Toner Transport Amount and Process Speed FIG. 8 shows the relationship between the process speed and the toner amount transported per drum rotation in this embodiment.

  As a measuring method, a bias was applied to the drum 1, the developing roller 44, the supply roller 45, and the developing blade 46 in the same manner as in the image formation, and the cartridge 50 was rotated idle for 30 seconds. Then, the toner conveyance amount per rotation of the drum was calculated from the toner amount collected to the cleaning blade 6a.

  As apparent from FIG. 8, there is a correlation between the process speed and the toner conveyance amount, and the toner conveyance amount per one rotation of the drum increases as the process speed decreases. This is because, when the process speed is high, toner is ejected into the developing container due to intense contraction of the supply roller 45 at the nip formed by the supply roller 45 and the development roller 44. is there. That is, in order to efficiently convey the toner to the cleaning blade 6a, it is necessary to suppress the rotation speed of the toner supply roller to some extent.

  FIG. 9 shows the relationship between the process speed and the cleaning blade turning when the drum 1 is rotated 10 times in the configuration of this embodiment. In this embodiment, five cartridges 50 were prepared for each process speed, and the cleaning blade turning rate was confirmed.

  Incidentally, the travel distance for 10 rotations of the drum 1 corresponds to the distance until a part of the opening 48 of the developer container 42 is opened by the automatic seal pulling mechanism 55 in this embodiment.

  Thus, in this example, no turning occurred when the process speed was 50 mm / sec or less. That is, the rotation of the cleaning blade can be suppressed by rotating the toner conveyance amount per rotation of the developing roller under the condition of 0.1 mmg or more.

  Incidentally, when the process speed is 200 mm / sec, the initial application amount of the toner to the supply roller 45 necessary for the toner conveyance amount per rotation of the developing roller to be 0.1 mmg or more is required to be four times or more. It is clear that this leads to a decrease in

  Based on the above results, in this embodiment, the first process speed (first driving speed) is performed at 50 mm / sec, and after the drum 1 has rotated 10 times, the second process speed (second driving speed) is reached. The seal was pulled by driving at 200 mm / sec.

(4) Automatic seal drawing sequence FIGS. 9 and 10 show a flowchart and timing chart of an automatic seal drawing sequence in this embodiment.

  In this embodiment, as described above, the cartridge 50 is provided with a rewritable memory tag 59. The control circuit unit 101 stores information indicating that the seal member has been opened in the memory tag 59 once the seal member is opened for the new cartridge 50. The control circuit unit 101 reads information from the memory tag 59 when the cartridge 50 is attached to the apparatus main body, and starts an automatic seal pulling sequence when it is determined that the attached cartridge is unopened. .

  As described above, the cartridge 50 is attached to and detached from the apparatus main body 100A by opening the front door 102 of the apparatus main body. When the front door 102 is opened, a kill switch (not shown) is turned off and a power supply circuit (not shown) of the image forming apparatus is turned off, thereby ensuring the safety of the user who operates the cartridge. When the front door 102 is closed, the kill switch is turned on and the power supply circuit of the image forming apparatus is turned on.

  When the power supply circuit is turned on from off, the control circuit 101 detects whether communication with the memory tag 59 is possible via the communication member 107 (step S1). If communication is impossible, a transfer bias is applied to the transfer roller 5 to detect the presence / absence of the cartridge, such as detecting a current flowing from the photosensitive drum 1 to the ground (step S2). As a result, if no cartridge is mounted, a warning is displayed on the display unit 104 to prompt the user to mount the cartridge (step S2-1). If a cartridge is mounted, an automatic seal drawing sequence is executed (step S8).

  If it is determined that a cartridge is installed, the control circuit 101 determines whether or not the cartridge is an unopened cartridge (step S3). In this embodiment, the determination is made by reading the information on the seal member not opened or the seal member opened stored in the memory tag 59 by the communication member 107.

  If the seal member has been opened, the control circuit 101 starts the motor M1 and drives the image forming apparatus at a second process speed of 200 mm / sec (step S4). Then, a predetermined startup operation (recovery operation, warming operation) at the time of power-on is executed (step S5). After executing a predetermined starting operation, the motor M1 is stopped (step S6), and the image forming apparatus is put on standby in a printable state (step S7).

  Here, the developing device 4 is moved to the developing position in the start-up operation in step S5, to the separated position in the standby state in step S7, and to the developing position in the subsequent image formation.

  If the seal member has not been opened, the control circuit 101 executes a predetermined starting operation including an automatic seal drawing sequence (step S8).

  At the start of the automatic seal drawing sequence, the developing device 4 has been moved to the separation position (step S9).

  The control circuit 101 activates the motor M1 to drive the image forming apparatus at a first process speed of 50 mm / sec (step S10).

  Thereby, the drum 1 is rotationally driven at a low speed corresponding to the first process speed. In this case, since the rotation of the drum 1 is at a low speed, the cleaning blade is not turned over. Simultaneously with the driving of the motor M1, the rotating drum is uniformly charged by applying a charging bias to the charging roller 2 in the same manner as in image formation.

  Thereafter, the control circuit 101 moves the developing device 4 from the separated position to the developing position (step S11).

  As a result, the driving force is transmitted from the developing drive gear 108 to the developing gear 60, and the developing roller 44, the supply roller 45, and the toner stirring and conveying member 62 are rotationally driven at a low speed corresponding to the first process speed. Further, the winding shaft 53 of the automatic seal pulling mechanism 55 is also rotated at a low speed corresponding to the first process speed, and the seal member 52 is opened at a low speed. Simultaneously with the movement of the developing device 4 from the separated position to the developing position, the same bias as that at the time of image formation is applied to the developing roller 44, the supply roller 45, and the developing blade 46, respectively. The drum 1 is exposed by the scanner unit 3.

  As described above, when driving is transmitted to the developing device 4, sealing is started, and at the same time, toner is conveyed from the supply roller 45 to the developing roller 44 to form an electrostatic latent image. The toner is transmitted to the cleaning blade 6a and supplied to the cleaning blade 6a.

  The control circuit unit 101 drives the image forming apparatus at a first process speed of 50 mm / sec, and the drum 1 rotates 10 times with the above-described sealing operation and toner supply operation to the cleaning blade 6a as a predetermined time. (Step S12).

  While the drum 1 rotates 10 times at the first process speed, the cleaning blade 6a has a toner ta as a lubricant (powder) applied in advance to the supply roller 45 in an amount sufficient to prevent the blade from turning up. Supplied. The seal member 52 is still in the middle of opening.

  After the drum 1 has made 10 revolutions (after a predetermined time), the control circuit unit 101 switches the drive of the motor M1, and drives the image forming apparatus at a second process speed of 200 mm / sec (step S13). .

  As a result, the drum 1, the developing roller 44, the supply roller 45, and the toner stirring and conveying member 62 are rotationally driven at a high speed corresponding to the second process speed. Even when the speed is switched to a high speed, the cleaning blade 6a is already supplied with an amount of toner that is sufficient to prevent the blade from being turned over, so that the cleaning blade does not turn up. The take-up shaft 53 of the automatic seal pulling mechanism 55 is also driven to rotate at a high speed corresponding to the second process speed. Thereby, the sealing member 52 in the middle of opening is opened at a high speed.

  While the drum 1 is rotated 10 times after the process speed is switched to the second process speed, the sealing member 52 is completely opened, and the automatic sealing is completed.

  Therefore, after the process speed is switched to the second process speed, the control circuit unit 101 determines whether another operation to be performed in the start-up operation is completed after the drum 1 has further rotated 10 times (step S14). (Step S15). If completed, the developing device 4 is moved from the developing position to the separated position (step S16), the motor M1 is stopped (step S17), and the image forming apparatus is put on standby in a printable state (step S18).

  In step S15, if other operations to be performed in the start-up operation have not yet been completed, the image forming apparatus continues to be driven at the second process speed until the other operations are completed. Then, after the end, the process proceeds to step S16 and subsequent steps.

  The configuration of the image forming apparatus of the above embodiment is summarized as follows. The image forming apparatus 100 forms an image on a recording medium P, and a cartridge 50 is detachably mounted on the image forming apparatus main body 100B. The cartridge 50 includes at least a rotatable image carrier 1 on which a latent image is formed, and a rotatable developer carrier for developing the latent image by conveying the developer t to the image carrier. 44. The cartridge 50 is preliminarily coated with a powder ta as a lubricant, and a developer supply member 45 that can be rotated to supply the developer to the developer carrier, and a developer storage that stores the developer. It has a container 42. Further, the cartridge 50 operates by receiving an opening 48 for sending the developer in the developer container to the developer supply member, a seal member 52 for sealing the opening, and driving the seal member. A seal member opening means 55 for opening is provided. Further, the cartridge 50 has a cleaning blade 6a in which a tip portion of the image carrier is brought into contact with a counter with respect to the rotation direction of the image carrier. The image carrier 1, the developer carrier 44, the developer supply member 45, and the seal member opening means 55 have the same drive source M1. The cartridge 50 in an unopened state of the seal member is mounted on the image forming apparatus main body 100B. At the start of the operation of the mounted image forming apparatus, the driving source M1 is driven at a first driving speed for conveying the powder to the image carrier 1 by a predetermined amount, and after a predetermined time, the first Drive at a second drive speed that is faster than the drive speed.

  By adopting the configuration of the present embodiment, it is possible to reliably perform the seal pulling by preventing the cleaning blade from turning up without increasing the time for the automatic seal pulling.

(4) Others 1) The attachment detection means for the apparatus main body 100A of the cartridge 50 and the new article detection means for the cartridge 50 are not limited to the memory tag 59 and the communication member 107 of the embodiment, and an appropriate means configuration may be adopted.

  (2) The developing device 4 is not limited to a contact-type developing device in which the developing roller 44 is in contact with the drum 1 as in the embodiment. As in the jumping development method, the developing device may be configured such that the developing roller 44 is disposed in opposition to the drum 1 in a non-contact manner with a predetermined slight gap by a spacer member. A developing device using a two-component developer may be used.

  (3) The image carrier 1 is a member on which a latent image developed with a developer is formed. In addition to an electrophotographic photosensitive member in an electrophotographic process, an electrostatic recording dielectric in an electrostatic recording process, a magnetic recording magnetic material in a magnetic recording process, and the like can be given. The endless belt type that circulates and moves is not limited to the drum type.

Schematic configuration diagram of an image forming apparatus according to an embodiment Sealing member-schematic cross-sectional view of a new cartridge before opening Explanatory drawing of developing device Illustration of automatic sealing mechanism Diagram of the development device moving to the development position Diagram of the developing device moving to the separation position Explanatory drawing of operation of developing device Graph showing the relationship between process speed and the amount of toner transported per drum revolution Correlation diagram of process speed and cleaning blade turning in the embodiment Flow chart of automatic seal drawing sequence in the embodiment Timing chart of automatic seal drawing sequence in the embodiment

Explanation of symbols

  100..Image forming apparatus, 100A..Image forming apparatus main body, P..Recording medium, 1 .... Image carrier, 6a..Cleaning blade, 42..Developer storage container, 44..Developer carrier, 45..Developer supply member, 48..Opening part, 50..Process cartridge, 52..Seal member, 55..Sealing member opening means, t..Developer (toner), ta..powder (lubrication) Agent), M1 ... drive source

Claims (1)

An image forming apparatus for forming an image on a recording medium,
At least a rotatable image carrier on which a latent image is formed, a rotatable developer carrier for developing the latent image by transporting the developer to the image carrier, and a lubricant in advance A developer supply member that can be rotated to supply the developer to the developer carrying member, a developer storage container that stores the developer, and a developer in the developer storage container. An opening for feeding to the developer supply member; a seal member for sealing the opening; a seal member opening means for receiving the drive to open the seal member; and a tip portion with respect to the image carrier A cartridge having a cleaning blade that is in contact with the counter with respect to the rotation direction of the image carrier, and is detachably attached to the main body of the image forming apparatus.
The image carrier, the developer carrier, the developer supply member, and the seal member opening means have the same drive source,
When the cartridge in an unopened seal member is mounted on the main body of the image forming apparatus, when the operation of the image forming apparatus is started, the drive source supplies the powder to the image carrier by a predetermined amount. The image forming apparatus is driven at a second drive speed that is higher than the first drive speed after a predetermined time.