Image forming apparatus

Abstract

To improve the exchangeability of an exposure unit by simplifying attachment and detachment of a door.SOLUTION: An image forming apparatus comprises an exposure unit, and a door rotatably held relative to an apparatus body. The door is provided with two rotation shafts, a holding part having flexibility and holding one rotation shaft, and a pull-out prevention member preventing bending of the holding part. The image forming apparatus further comprises: a slide mechanism that is engaged with an engaging shaft near the other rotation shaft of the door and slides back and forth relative to an apparatus body in conjunction with opening and closing of the door; and a pressure mechanism that is held rotatably relative to the apparatus body in parallel with the direction of movement of the slide mechanism and rotates in conjunction with the slide mechanism. The pressure mechanism moves between a first position where it applies pressure to the exposure unit and a second position where it is separated from the exposure unit. Removing the pull-out prevention member allows bending of the holding part and removal of the door from the apparatus body.SELECTED DRAWING: Figure 7(b)

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus using electrophotographic technology, such as a printer, a copying machine, a facsimile machine, or a multifunction machine. [Background technology]

[0002] Conventionally, some image forming apparatuses have a front panel with an opening that allows the drum, developing, and exposure units to be inserted into and removed from the main body along the rotational axis of the photosensitive drum from the front side, and a cover that covers the front side of the opening. One end of the cover is fixed to the main body by a hinge, and the cover is rotatable relative to the main body by the hinge. The replacement work is completed by an operator opening the cover, removing the unit from the main body, inserting a new unit through the opening, installing it in the designated position in the main body, and closing the cover. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-8820 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the configuration as disclosed in Patent Document 1, when the exposure unit is replaced for maintenance, the exposure unit is pulled out toward the front side through an opening formed in the front side plate.

[0005] An operator performs maintenance on an exposure unit by disconnecting a cable attached to the exposure unit, then removing the exposure unit, and then replacing it by reconnecting the cable to a new exposure unit.

[0006] During such maintenance, users and service personnel must be careful of open covers and openings. This can lead to the exposure unit hitting the opening and causing damage to the exposure unit, or the cable getting caught and bending or breaking. Forcibly reinserting the unit into the device in this state could result in damage to the cable or exposure unit, potentially causing image defects.

[0007] The present invention has been made in consideration of the above problems, and aims to provide an image forming apparatus that can improve the replaceability of exposure units by simplifying the attachment and detachment of doors, thereby preventing image defects. [Means for solving the problem]

[0008] In order to achieve the above object, the image forming apparatus of the present invention comprises an exposure unit and a door that is rotatably held relative to the apparatus body, the door having two rotation axes, a flexible holding portion that holds one of the rotation axes, and a stop member that prevents the holding portion from bending, and further comprising a sliding mechanism that engages with the holding portion that holds the other door rotation axis and slides back and forth relative to the mounting body in conjunction with the opening and closing of the door, and a pressure mechanism that is rotatably held relative to the mounting body parallel to the movement direction of the sliding mechanism and rotates in conjunction with the sliding mechanism, the pressure mechanism moving between a first position where it presses the exposure unit and a second position where it is separated, and the holding portion can be bent by removing the stop member, and the door can be removed from the mounting body. [Effects of the Invention]

[0009] According to the present invention, by providing a locking member that prevents the flexible rotation support portion from bending and coming off, it is possible to attach and detach the door in conjunction with the application and separation of pressure of the exposure unit. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 2(a)]FIG. 2 is a schematic perspective view of an optical print head according to the present embodiment. [Figure 2(b)] FIG. 1 is a schematic perspective view of an FFC according to an embodiment of the present invention. [Figure 3(a)] FIG. 2 is a perspective view of the image forming apparatus when the cartridge cover is open. [Figure 3(b)] FIG. 2 is a perspective view of the image forming apparatus with the drum and the developing unit removed. [Figure 4] FIG. 2 is a schematic diagram of a pressure applying configuration of a developing unit and an exposure unit in the present embodiment. [Figure 5(a)] FIG. 10 is a schematic diagram of a pressure applying configuration showing a cartridge cover in a closed state in the present embodiment. [Figure 5(b)] FIG. 10 is a schematic diagram of a pressure applying configuration showing a cartridge cover open state in the present embodiment. [Figure 6(a)] FIG. 4 is a cross-sectional view of the developing unit and the exposure unit in a pressurized state in this embodiment. [Figure 6(b)] FIG. 2 is a cross-sectional view of the developing unit and the exposure unit in a separated state in this embodiment. [Figure 7(a)] FIG. 2 is a schematic diagram illustrating the configuration of a cartridge cover. [Figure 7(b)] 3A and 3B are schematic diagrams illustrating the configuration of a cartridge cover and a retaining member. [Figure 7(c)] FIG. 10 is a schematic diagram of the cartridge cover with the retaining member removed. [Figure 8] FIG. 2 is a perspective view showing the optical print head being removed from the image forming apparatus main body. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the components described in this description are merely examples, and the present invention is not limited to the embodiments described in this description.

[0012] (Image forming device) First, a schematic configuration of the image forming apparatus 1 will be described. FIG. 1 is a schematic cross-sectional view of the image forming apparatus 1. The image forming apparatus 1 shown in FIG. 1 is a color printer (MFP: Multi Function Printer) equipped with a reading device, but the embodiment may also be a copier that does not have a reading device. Furthermore, the embodiment is not limited to a so-called tandem color image forming apparatus equipped with multiple photosensitive drums 103 as shown in FIG. 1, but may also be a color image forming apparatus equipped with a single photosensitive drum 103 or an image forming apparatus that forms monochrome images.

[0013] The image forming apparatus 1 shown in FIG. 1 includes four image forming units 102Y, 102M, 102C, and 102K (hereinafter collectively referred to as "image forming unit 102") that form toner images of yellow, magenta, cyan, and black, respectively. The image forming units 102Y, 102M, 102C, and 102K also include photosensitive drums 103Y, 103M, 103C, and 103K (hereinafter collectively referred to as "photosensitive drum 103"). These photosensitive drums are spaced apart from one another. The image forming units 102Y, 102M, 102C, and 102K also include chargers 104Y, 104M, 104C, and 104K (hereinafter collectively referred to as "charger 104") that charge the photosensitive drums 103Y, 103M, 103C, and 103K, respectively. Furthermore, the image forming units 102Y, 102M, 102C, and 102K are equipped with LED (Light Emitting Diode, hereinafter referred to as LED) exposure units 500Y, 500M, 500C, and 500K (hereinafter collectively referred to as "exposure units 500") as exposure light sources that emit light to expose the photosensitive drums 103Y, 103M, 103C, and 103K. The image forming apparatus 1 shown in FIG. 2 is a so-called "bottom exposure type" image forming apparatus that exposes the photosensitive drum 103 from below. Furthermore, the image forming units 102Y, 102M, 102C, and 102K are equipped with developing units 106Y, 106M, 106C, and 106K (hereinafter collectively referred to as "developing units 106") that develop the electrostatic latent image on the photosensitive drum 103 with toner and develop a toner image of each color on the photosensitive drum 103. The letters Y, M, C, and K attached to the symbols indicate the colors of the toner.

[0014] The image forming apparatus 1 includes an intermediate transfer belt 107 onto which a toner image formed on a photosensitive drum 103 is transferred, and primary transfer rollers 108 (Y, M, C, K) that sequentially transfer the toner images formed on the photosensitive drum 103 onto the intermediate transfer belt. The image forming apparatus 1 also includes a secondary transfer roller 109 that transfers the toner image on the intermediate transfer belt 107 onto a recording material S conveyed from a paper feed unit 101, and a fixing device 100 that fixes the secondarily transferred image onto the recording material S.

[0015] After the primary transfer, toner remains on the surfaces of the photosensitive drums 103Y, 103M, 103C, and 103K. This residual toner is removed by drum cleaning devices (first cleaning devices) 8Y, 8M, 8C, and 8K (hereinafter, also collectively referred to as "drum cleaning devices 8") and collected in the collected toner container 5.

[0016] After the secondary transfer, toner remains on the surface of the intermediate transfer belt 107. This remaining toner is removed by a belt cleaning device (second cleaning device) 7 and collected in a collected toner container 5.

[0017] (Image formation process) The exposure unit 500Y exposes the surface of the photosensitive drum 103Y, which has been charged by the charger 104Y. As a result, an electrostatic latent image is formed on the photosensitive drum 103Y. Next, the developing unit 106Y develops the electrostatic latent image formed on the photosensitive drum 103Y with yellow toner. The yellow toner image developed on the surface of the photosensitive drum 103Y is transferred onto the intermediate transfer belt 107 by the primary transfer roller 108Y. Magenta, cyan, and black toner images are also transferred to the intermediate transfer belt 107 in a similar image formation process.

[0018] The toner images of each color transferred onto the intermediate transfer belt 107 are transported to a secondary transfer section T2 by the intermediate transfer belt 107. A transfer bias is applied to a secondary transfer roller 109 disposed at the secondary transfer section T2 to transfer the toner images onto the recording material S. The toner images transported to the secondary transfer section T2 are transferred onto the recording material S transported from a paper feed section (paper feed cassette) 101 by the transfer bias of the secondary transfer roller 109.

[0019] The recording material S is stored in a stack in the paper feed unit 101 and is fed to the conveying path 20 in accordance with the image formation timing. The paper feeding method involves first flipping up the leading edge of the recording material S due to friction of the paper feed roller 80, and then conveying only one sheet of recording material S to the conveying path 20 by a pair of paper separating conveying rollers 9a and 9b to prevent double feeding of the recording material S. The recording material S is then pulled out by a pair of conveying rollers 10a and 10b, passes through the conveying path 20, and is conveyed to a pair of registration rollers 11a and 11b, where it is stopped temporarily. Note that the pair of registration rollers 11a and 11b perform skew correction and timing correction before conveying to the secondary transfer unit T2.

[0020] The recording material S onto which the toner image has been transferred at the secondary transfer unit T2 is conveyed to the fixing unit 100. The fixing unit 100 fixes the toner image onto the recording material S by heat and pressure. The recording material S that has been subjected to the fixing process by the fixing unit 100 is discharged to the paper discharge unit 111.

[0021] As shown in FIG. 2, the image forming apparatus 1 is also provided with toner containers 4Y, 4M, 4C, and 4K (hereinafter, also collectively referred to as "toner container 4"). As image formation is performed, the amount of toner in a developing unit 641 (described later) decreases. When this occurs, toner is supplied to the developing unit 641 (described later) from toner containers 4Y, 4M, 4C, and 4K provided corresponding to the image forming sections 102Y, 102M, 102C, and 102K via pipes (not shown). That is, the developing unit 641 (described later) provided in the image forming apparatus 1 described in this embodiment replenishes new toner from the toner container 4 while transporting a portion of the excess toner to the collected toner container 5 as residual toner.

[0022] (Drum unit and developing unit) A drum unit 518, which is an example of a replaceable replacement unit, is attached to the image forming apparatus 1 of this embodiment. The drum unit 518 is a cartridge that is replaced by an operator such as a user or a maintenance technician.

[0023] Drum unit 518 (Y, M, C, K) of this embodiment includes photosensitive drums 103 (Y, M, C, K) rotatably supported on a frame of drum unit 518. When these photosensitive drums 103 (Y, M, C, K) need to be replaced due to wear or deterioration over time, an operator removes drum unit 518 (Y, M, C, K) from the main body of image forming apparatus 1 and replaces it.

[0024] Furthermore, the image forming apparatus 1 of this embodiment is equipped with a developing unit 641 that is separate from the drum unit 518. The developing device 106 is equipped with a developing sleeve, which is a developer carrier that carries the developer. The developing unit 641 is provided with multiple gears for rotating a screw that mixes the toner and carrier. When these gears and screws deteriorate over time, an operator removes the developing unit 641 from the main body of the image forming apparatus 1 and replaces it. Furthermore, a certain amount of toner is removed from the developing unit 641 as residual toner and transported to the recovered toner container 5.

[0025] (Basic optical print head configuration) Next, the optical print head 105 provided in the exposure unit 500 will be described with reference to Figures 2(a) and 2(b). The optical print head 105 described in this embodiment is of a type that exposes the photosensitive drum 103 using light-emitting elements such as LEDs arranged along the rotation axis direction of the photosensitive drum 103. In this embodiment, the optical print head 105 is provided vertically below the rotation axis of the photosensitive drum 103, and the LEDs included in the optical print head 105 expose the photosensitive drum 103 from below.

[0026] 2(a) is a schematic perspective view of the optical print head 105 in this embodiment, which includes a lens array 506, a holder 505 that holds a substrate (not shown), and pins 507 and 508 that are positioned in a drum unit 518. As shown in FIG. 2(b), the optical print head 105 includes a flexible flat cable that electrically connects an FFC connector 504 and a control board 162 via an FFC 160.

[0027] (Pressure and separation configuration) The configuration in this embodiment in which the developing unit 641 and the exposure unit 500 are pressed against or separated from the drum unit 518 will be described with reference to the drawings.

[0028] 3(a) and 3(b) are perspective views of the image forming apparatus 1 when the cartridge cover 558 is open. Also, Fig. 4 is a schematic diagram of the pressure configuration of the developing unit 641 and the exposure unit 500 against the drum unit 518 in this embodiment.

[0029] 5(a) and 5(b) are schematic diagrams of the pressurizing configuration showing the state linked to the opening and closing of the cartridge cover 558 in this embodiment.

[0030] 6(a) and 6(b) are cross-sectional views showing the state in which the developing unit 641 and the exposure unit 500 are pressed against and separated from the drum unit 518 in this embodiment.

[0031] 3(a) and 3(b), openings 642 are formed in the front side panel so that the drum unit 518, developing unit 641, and exposure unit 500 can be inserted and removed from the front side of the image forming apparatus 1. Cartridge covers 558 (Y, M, C, K) that can be opened and closed are provided so as to cover the openings 642 for each color (Y, M, C, K) separately. In this embodiment, a configuration will be described in which the drum unit 518 and developing unit 641 are provided in the image forming apparatus 1 main body so as to be separately replaceable.

[0032] A front cover 6 is provided on the front side of the image forming apparatus 1 main body, and when performing maintenance, a user, service technician, or other worker opens the front cover 6, opens the cartridge cover 558 of the station to be replaced (in this embodiment, K station), and begins work from the state shown in Figure 3(a).

[0033] 4(a) and 4(b), cartridge cover 558 is rotatably supported by two rotation shafts 58a and 58b on rails 400 held by the front and rear side plates. A maintenance worker opens cartridge cover 558 to open opening 642 as shown in FIG. 3(b). At that time, developing unit 641 and exposure unit 500 are separated from drum unit 518 positioned in the main body of image forming apparatus 1 as described below, and can be removed through opening 642.

[0034] As shown in Fig. 4(a), an engagement shaft 58c is provided near one of the rotation shafts 58a of the cartridge cover 558, and engages with an engagement portion 450a of a sliding mechanism 450 supported so as to be slidable in the front-rear direction relative to the rail 400. This allows the sliding mechanism 450 to move in the front-rear direction in conjunction with the opening and closing of the cartridge cover 558. Also, as shown in Fig. 4(b), a pressure mechanism 410 equipped with a rotation shaft is supported by the rail 400 so as to be rotatable about an axis in the front-rear direction.

[0035] As shown in FIGS. 5(a) and 5(b), the link portions 450b and 450c provided on the sliding mechanism 450 move in the front-rear direction together with the sliding mechanism 450 in conjunction with the opening and closing of the cartridge cover 558.

[0036] 5(a), when cartridge cover 558 is closed, pressure mechanism 410 engages with the grooves of link portions 450b and 450c, which slide forward, and is swung upward to reach a first position where exposure unit 500 is positioned relative to drum unit 518. Furthermore, pressing members 450d and 450e held by sliding mechanism 450 slide forward, so that developing unit 641 is pressurized upward and urged against drum unit 518, thereby positioning it.

[0037] 5(b), when cartridge cover 558 is open, pressure mechanism 410 engages with the grooves of link portions 450b and 450c, which slide rearward, and is swung downward to reach a second position where exposure unit 500 is separated from drum unit 518. Similarly, pressing members 450d and 450e slide rearward, thereby releasing pressure on development unit 641 and separating it from drum unit 518.

[0038] With the cartridge cover 558 closed, the developing unit 641 and the exposure unit 500 are close to the drum unit 518 as shown in Figure 6(a), and therefore there is a possibility that the photosensitive drum 103, the optical print head 105, and the developing sleeve may be scratched when the developing unit 641 and the drum unit 518 are inserted or removed from the main body of the image forming apparatus 1 for replacement or the like. Therefore, by separating the developing unit 641 and the exposure unit 500 from the drum unit 518 as shown in Figure 6(b) in conjunction with the operation of opening the cartridge cover 558, a sufficient distance can be secured to prevent contact, and the photosensitive drum 103, the optical print head 105, and the developing sleeve are less likely to be scratched when each unit is inserted or removed.

[0039] As described above, in conjunction with the opening and closing of cartridge cover 558, developing unit 641 and exposure unit 500 are pressed against or separated from drum unit 518 positioned in the image forming apparatus 1 main body.

[0040] By opening cartridge cover 558, a user or an operator such as a serviceman can insert or remove drum unit 518 and developing unit 641 into or from image forming apparatus 1.

[0041] Furthermore, the FFC 160 provided on the exposure unit 500, which presses and separates from the drum unit 518, is configured so that the FFC 160 bends while remaining connected to the optical print head 105, preventing unexpected loads from being applied to the FFC 160 or the optical print head 105.

[0042] (Optical print head 105 replacement flow) Next, we will explain the replacement flow of the optical print head 105 when maintenance is required due to a malfunction of the optical print head 105. Figure 7 is a schematic diagram of the cartridge cover 558, and Figure 8 is a perspective view of the optical print head 105 during removal.

[0043] 7(a), a retaining member 56 is provided near a holding portion 58d that holds the other rotation shaft 58b of the cartridge cover 558. Therefore, the holding portion 58d cannot be bent, and the cartridge cover 558 cannot be removed from the rail 400.

[0044] In this embodiment, the retaining member 56 employs a snap-fit ​​configuration with respect to the cartridge cover 558, as shown in Fig. 7(b). Specifically, an engaging portion 56e of the retaining member 56 engages with an engaged portion 58e of the cartridge cover 558, and a claw shape 56f of the retaining member 56 hooks onto a rib shape 58f of the cartridge cover 558 to prevent the retaining member 56 from coming off, allowing for easy attachment and detachment.

[0045] The replacement flow for the optical print head 105 is similar to that for replacing the drum unit 518 and the developing unit 641: open the front cover 6 and the cartridge cover 558, separate them as described above, and remove the drum unit 518 and the developing unit 641 from the main body of the image forming apparatus 1 through the opening 642.

[0046] 7(c), by removing the retaining member 56 from the cartridge cover 558, the holding portion 58d can be bent in the direction of the arrow. After the rotating shaft 58b is removed from the rail 400 while the holding portion 58d is kept bent, the other rotating shaft 58a and the engaging shaft 58c can be removed, and the cartridge cover 558 can be completely removed from the rail 400.

[0047] Furthermore, because cartridge cover 558 was removed in an open state, exposure unit 500 is in a separated state and stored within rail 400. Therefore, it is necessary to use a tool or the like to pull sliding mechanism 450 forward and lift exposure unit 500 to a position where it can be pulled out together with optical print head 105. Then, after FFC 160 is removed from optical print head 105, optical print head 105 is removed from the main body of image forming apparatus 1, a new optical print head 105 is inserted into the main body of image forming apparatus 1, FFC 160 is attached, and the new optical print head 105 is returned to the attached position.

[0048] When inserting the optical print head 105 through the opening in the front panel into the main body of the image forming apparatus 1, great care must be taken to avoid it getting caught on the opening in the front panel or on surrounding components. In particular, if the lens array 506 is hit and damaged, this could lead to poor image quality.

[0049] As in this embodiment, by removing the retaining member 56, the cartridge cover 558 can be removed from the rail 400, and the work space for the user or service person is secured, thereby improving the ease of replacement.

[0050] Thereafter, retaining member 56 is reattached to cartridge cover 558 to restrict bending of holding portion 58d, thereby preventing cartridge cover 558 from coming off. When drum unit 518 and developing unit 641 are returned to their attached positions and cartridge cover 558 and front cover 6 are closed to return them to their original states, image forming apparatus 1 returns to an operable state.

[0051] As described above, in a configuration that includes a door that covers the opening when the drum unit, development unit, and exposure unit are replaced, and that allows the development unit and exposure unit to be attached and detached to and from the drum unit in conjunction with opening and closing the door, the holding portion of one of the door's pivot shafts is flexible and is provided with an anti-slip member that prevents the holding portion from tipping over, the door can be removed from the image forming device main body by removing the anti-slip member during maintenance, and replaceability is improved by ensuring work space for users and service personnel.

[0052] Although the illustrations in this embodiment are for the K station, the optical print head can be replaced in the Y, M, and C stations using the same procedure. The drum unit and developing unit may also be implemented as a process cartridge in which the drum unit and developing unit are integrated. [Explanation of symbols]

[0053] 1. Image forming device 6 Front cover 56 Anti-slip member 58a, 58b Rotating shaft 58d Holding part 105 Optical print head 400 rail 410 Pressure Mechanism 450 Sliding mechanism 450b, 450c link members 450e, 450d Pressing member 518 drum unit 558 Cartridge Cover 641 Development unit 642 Aperture

Claims

1. In the image forming apparatus, an exposure unit; a door that is rotatably held by two rotation shafts relative to the image forming apparatus, the door including a flexible holding portion that holds one of the rotation shafts, and a retaining member that prevents the holding portion from bending; a sliding mechanism that engages with an engaging shaft near the other pivot shaft of the door and slides back and forth relative to the image forming apparatus in conjunction with opening and closing of the door; a pressure mechanism that is held rotatably in a moving direction of the sliding mechanism relative to the image forming apparatus and that swings between a first position where the exposure unit is pressed and a second position where the exposure unit is separated in conjunction with the sliding mechanism; Equipped with The image forming apparatus according to claim 1, wherein the retaining member is removed, thereby making it possible to bend the holding portion and remove the door from the image forming apparatus.

2. 2. The image forming apparatus according to claim 1, wherein the developing unit is attached and detached in conjunction with the opening and closing of the door.

Images