Developing device

Abstract

To open, with a simple configuration, a seal member provided in a toner supply port of a developing device.SOLUTION: A developing device has a developer storage unit, a developing unit that has a rotatable developer carrier, and a stirring member that stirs developer in the developer storage unit. The developer storage unit and the developing unit are connected through an opening. Before the developing device is mounted in an image forming apparatus, a sealing sheet connected with the stirring member is fastened to a fastening part around the opening and the opening is sealed. After the developing device is mounted in the image forming apparatus, the stirring member operates and the sealing sheet is removed from the fastening part, and thereby the developer storage unit and the developing unit communicate with each other. A protrusion is provided on the downstream side of the fastening part and the upstream side of the opening in a second direction intersecting a first direction in which a rotation shaft of the stirring member extends. The height of the protrusion is higher than the height of at least part of a fastening position protrusion formed at a fastening position.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a developing device. [Background technology]

[0002] In electrophotographic image forming apparatuses such as printers, copiers, and multifunction machines, a developing device is provided that supplies toner to an electrostatic latent image formed on a photosensitive drum to develop it. The developing device has a toner chamber for storing toner, and a supply roller supplies toner from the toner chamber to a developing roller, which then supplies toner to the surface of the photosensitive drum.

[0003] The developing device described in Patent Document 1 (JP Patent Publication 8-292634) includes a toner chamber that contains toner, an agitating member for agitating the toner provided inside the toner chamber, and a supply port that supplies toner from the toner chamber to a developing chamber provided with a supply roller and a developing roller. In Patent Document 1, the supply port between the developing chamber and the toner chamber is initially sealed by a seal member connected to the agitating member, and when the developing device is mounted on the image forming apparatus main body, the seal member is automatically unsealed by the rotational movement of the agitating member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-292634 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in such a developing device, the torque required to unseal the seal member may increase. For example, in an in-line type color laser printer in which multiple process cartridges are operated simultaneously, when at least two or more developing devices are operated by a common drive source, the required input torque becomes large. As a result, the drive may become unstable or a larger motor may be required.

[0006] The present invention has been made in consideration of the above problems, and has an object to unseal a seal member provided at a toner supply port of a developing device with a simple structure. [Means for solving the problem]

[0007] The present invention employs the following configuration. A developing device that can be attached to an image forming apparatus, a developer storage section for storing a developer; a developing section having a rotatable developer carrier that carries a developer; a stirring member disposed in the developer container and configured to stir the developer contained therein; having the developer container and the developing unit are connected via an opening, before the developing device is mounted on the image forming apparatus, a sealing sheet connected to the stirring member is fixed to a fixing portion around the opening, thereby sealing the opening, After the developing device is mounted on the image forming apparatus, the stirring member operates to separate the sealing sheet from the fixed portion, thereby connecting the developer accommodating portion and the developing portion. 1. A developing device comprising: a convex portion is provided downstream of the fixing portion and upstream of the opening in a second direction intersecting with a first direction in which a rotation shaft of the stirring member extends, The height of the protrusion is higher than the height of at least a part of the fixing position protrusions formed at the fixing position. The developing device is characterized in that Effect of the Invention

[0008] According to the present invention, the seal member provided at the toner supply port of the developing device can be unsealed with a simple structure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of an image forming apparatus according to a first embodiment of the present invention; [Diagram 2] FIG. 1 is a schematic diagram illustrating an example of a process cartridge according to a first embodiment of the present invention; [Diagram 3] FIG. 1 is a schematic diagram illustrating a configuration of a developing unit according to a first embodiment of the present invention; [Figure 4] Schematic diagram for explaining a method for welding an encapsulating sheet [Diagram 5] Schematic diagram for explaining opening of the sealing sheet [Figure 6] FIG. 11 is a schematic diagram illustrating a configuration of a developing unit according to a second embodiment of the present invention; [Figure 7] FIG. 11 is a schematic diagram illustrating a configuration of a developing unit according to a third embodiment of the present invention; [Figure 8] FIG. 13 is a schematic diagram illustrating an agitation member rotating shaft and a rotating bearing according to the third embodiment. [Figure 9] FIG. 13 is a schematic diagram illustrating a stirring member according to a fourth embodiment of the present invention. [Figure 10] FIG. 1 is a schematic diagram for explaining a configuration of a developing unit according to a comparative example; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described in the embodiment are not intended to limit the scope of the present invention to those alone. Furthermore, the materials, shapes, etc. of the members once described in the following description are the same as those described initially, unless otherwise specified. Well-known or publicly known technologies in the relevant technical field can be applied to configurations and processes not particularly shown or described. Furthermore, duplicated descriptions may be omitted.

[0011] [Example 1] <Overall configuration of image forming apparatus> 1 is a schematic diagram showing the configuration of an image forming apparatus 100 according to the present invention. The image forming apparatus 100 is provided with process cartridges Cy, Cm, Cc, and Ck that store toner of yellow y, magenta m, cyan c, and black k, which are detachably mountable to the apparatus main body. A part of the image forming operation is performed with the process cartridges Cy, Cm, Cc, and Ck mounted in the apparatus main body. Hereinafter, when it is not necessary to distinguish between colors, the subscripts y, m, c, and k will be omitted.

[0012] The image forming apparatus 100 includes an intermediate transfer belt unit 6. The intermediate transfer belt unit 6 includes a flexible transfer belt 61 stretched around a turn roller 64, a drive roller 65, and a tension roller 66. The intermediate transfer belt 61 moves in a circular motion in the direction of the arrow R1 as the turn roller 64, the drive roller 65, and the tension roller 66 rotate by receiving a driving force from a drive unit 90. The intermediate transfer belt unit 6 also includes primary transfer rollers 62y, 62m, 62c, and 62k that face the process cartridges Cy, Cm, Cc, and Ck, respectively, via the intermediate transfer belt 61. This position is called a primary transfer position, and at the primary transfer position, the toner images of the colors y, m, and ck are transferred from the photosensitive drum 1 to the intermediate transfer belt 61 in a superimposed manner. A secondary transfer roller 63 is also provided at a position that faces the turn roller 64 via the intermediate transfer belt 61. This position is called the secondary transfer position, and a full-color image is transferred from the intermediate transfer belt 61 to the recording material P at the secondary transfer position.

[0013] The recording material P stored in the cassette 69 is picked up by a pickup roller 68 and conveyed to a secondary transfer position by a pair of conveying rollers 71. The recording material P that has passed the secondary transfer position is heated and pressed in a fixing device 7, so that the full-color image is fixed onto the recording material. Thereafter, the recording material P is discharged to a discharge tray 73 by a pair of discharge rollers 72.

[0014] Of the four process cartridges, process cartridge Cy is disposed on the most upstream side in the circulating movement direction R1 of the transfer belt 61. Process cartridge Cm is disposed downstream of process cartridge Cy, followed by process cartridge Cc, and of the four, process cartridge Ck is disposed on the most downstream side. The secondary transfer positions are located further downstream than each of the primary transfer positions. However, the number and arrangement of process cartridges mounted in the image forming apparatus are not limited to this and may be appropriately set as necessary.

[0015] The control unit 200 controls the image forming operation based on image information. The control unit 200 can utilize an information processing device and a control circuit equipped with computing resources such as a CPU, memory, ROM, and RAM. The power supply 80 is a high-voltage power supply device, and supplies a charging voltage, a transfer voltage, and the like during the image forming operation. The drive unit 90 is a motor or the like, and controls the rotation and drive of various members by transmitting a driving force using a transmission means such as a gear or a belt.

[0016] <Process cartridge configuration> The configuration of the process cartridge according to the present invention will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view showing the configuration of the process cartridge Cy according to the present invention. Note that the process cartridges Cm, Cc, and Ck have the same configuration as the process cartridge Cy except for the color of toner stored therein.

[0017] The process cartridge Cy includes a photosensitive drum 1 as an image carrier, a charging roller 2 as a charging means, a developing device 4, and a photosensitive drum cleaner 5. The developing device 4 stores a negatively charged non-magnetic one-component toner (developer, hereinafter simply referred to as toner) having an external additive attached to its surface, and includes a developing roller 41 as a rotatable developer carrier and a supply roller 42 as a supply means. The supply roller 42 is a roller made of a foam material capable of containing toner therein, and supplies toner to the surface of the developing roller 41 by rotating while in contact with the developing roller 41. Thereafter, the amount of toner on the developing roller is adjusted by a regulating blade 43 for regulating the amount of toner on the developing roller. The photosensitive drum 1 rotates in the direction of an arrow W1, and receives toner supply from the developing roller 41 rotating in the direction of an arrow W2. Here, the supply roller 42 supplies toner to the developing roller 41 while rotating in the same direction as the developing roller 41 (arrow W3), but may rotate in the opposite direction to the developing roller 41.

[0018] <Image formation process> When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, based on the output calculated by the control unit 200 from image information input from the host device, the charged surface of the photosensitive drum 1 is irradiated with laser light L emitted from a scanner unit (exposure device 3) serving as an exposure means. As a result, an electrostatic latent image is formed on the photosensitive drum 1 in accordance with the image information.

[0019] Next, the electrostatic latent image formed on the photosensitive drum 1 is developed into a toner image by the developing device 4. At this time, the supply roller 42 rotates in the direction of the arrow W3 to supply the toner contained in the developing device 4 to the developing roller 41, and the developing roller 41 rotates in the direction of the arrow W2 to supply the toner to the surface of the photosensitive drum 1. As a result, the electrostatic latent image on the photosensitive drum is visualized. Then, a voltage of the opposite polarity to the normal charging polarity of the toner is applied to the primary transfer roller 14 from a power source 80 (primary transfer voltage power source) serving as a primary transfer voltage application means. As a result, Thus, the toner image on the photosensitive drum 1 is primarily transferred onto the intermediate transfer belt 61. When a full-color image is formed, the above-mentioned process is performed in sequence in the process cartridges Cy, Cm, Cc, and Ck, and the toner images of each color are then primarily transferred onto the intermediate transfer belt 61 in a superimposed state.

[0020] Thereafter, the recording material P is conveyed to the secondary transfer portion in synchronization with the movement of the intermediate transfer belt 61. Then, a voltage of a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 63 from a power source 80 (secondary transfer voltage power source) serving as a secondary transfer voltage application means. As a result, the four-color toner image on the intermediate transfer belt 61 is secondarily transferred collectively onto the recording material P.

[0021] The recording material P onto which the toner image has been transferred is conveyed to a fixing device 7 as a fixing means. In the fixing device 7, the recording material P is subjected to heat and pressure to fix the transferred toner image, and is then discharged onto a discharge tray 73.

[0022] In order to control the amount of toner developed as a developer, the developing device 4 performs reversal development by bringing a developing roller 41 as a developer carrier into contact with the photosensitive drum 1 while maintaining a speed difference. That is, the developing device 4 develops an electrostatic image by attaching toner charged with the same polarity as the charging polarity of the photosensitive drum 1 (negative polarity in the present invention) to a portion (image portion, exposed portion) on the photosensitive drum 1 where the charge has decayed due to exposure. In this embodiment, the developing roller 41 moves at a speed ratio of 1.4 times that of the photosensitive drum 1.

[0023] Next, the control of the image forming process will be described in more detail. The values ​​of the bias and the like described here are merely examples, and are not limited to these values, and are appropriately set as necessary. The bias (voltage) applied to each member is supplied from a power source 80 as a bias supply means based on the value controlled by the control unit 200.

[0024] When the control unit 200 receives the image information, it first drives the main motor included in the drive unit 90. This main motor starts the rotation of the photosensitive drum 1 of each of the process cartridges Cy, Cm, Cc, and Ck, and the circular movement of the intermediate transfer belt 61. In addition, in conjunction with the rotation of the photosensitive drum 1, the development roller 41 and the supply roller 42 also start to rotate.

[0025] In parallel with the driving of the main motor, the power source 80 applies a charging bias of -1000 V to the charging roller 2. As a result, the photosensitive drum 1 is approximately uniformly charged by the charging roller 2 while rotating in the direction of the arrow W1. At this time, a dark potential Vd of -500 V is formed on the surface of the photosensitive drum 1.

[0026] An image forming process is started, and when the surface of the photosensitive drum 1 that has been appropriately charged by the charging roller 2 has passed the position closest to the developing device 4, the developing roller 41 is brought into contact with the photosensitive drum 1.

[0027] Next, the control unit 200 causes the exposure device 3 to irradiate a laser beam based on the image information. As a result, an electrostatic latent image (light area potential Vl) of −100 V is formed on the surface of the photosensitive drum 1.

[0028] As the photosensitive drum 1 rotates, this electrostatic latent image moves to the development nip N1, which is the contact position between the photosensitive drum 1 and the development roller 41. At this time, the power source 80 applies a bias (development bias Vdc) of -300V to the development roller 41. This potential difference causes the development roller 41 to supply toner to the electrostatic latent image, thereby visualizing the electrostatic latent image and forming a toner image (developer image). The power source 80 also applies a supply bias of -400V to the supply roller 42. This potential difference promotes the supply of toner from the supply roller 42 to the development roller 41. do.

[0029] The toner image formed on the photosensitive drum 1 moves to the primary transfer position, that is, the contact position between the photosensitive drum 1 and the transfer belt 61. At that time, the power source 80 applies a primary transfer bias of +500V to the primary transfer roller 62y. Due to this potential difference, the toner image is primarily transferred to the surface of the intermediate transfer belt 61. The toner image primarily transferred onto the intermediate transfer belt 61 is conveyed to the secondary transfer position, which is the nip between the secondary transfer roller 63 and the turn roller 64, by the circular movement of the intermediate transfer belt 61. The primary transfer onto the intermediate transfer belt 61 is performed for each color in a superimposed manner, thereby forming a four-color image. Then, the toner image is secondarily transferred to the recording material P at the secondary transfer position. The toner image secondarily transferred onto the recording material P is fixed to the recording material P by pressure and heat applied by the fixing device 7, becoming the final image.

[0030] On the other hand, of the toner images formed on the photosensitive drums 1, toner that remains without being transferred to the intermediate transfer belt 61 is scraped off by a cleaning blade 51 that comes into contact with the photosensitive drums 1, and is collected in a photosensitive drum cleaner 5. Also, of the toner images formed on the transfer belt 61, toner that remains without being transferred to the recording material P is conveyed to a cleaning device 8. The cleaning device 8 includes a cleaning blade 81 that comes into elastic contact with the transfer belt 61, and scrapes off the toner from the surface of the transfer belt 61.

[0031] When the process of forming a toner image on the photosensitive drum 1 is completed, the developing roller 41 is separated from the photosensitive drum 1, and the bias applied to the charging roller 2, the developing roller 41, and the supply roller 42 is cut off. Then, after all the processes such as secondary transfer and fixing are completed, the drive of the main motor is stopped.

[0032] <Configuration of the developing device> The developing device 4 in this embodiment will be described with reference to FIG. 3. As shown in FIG. 3(a), the developing device 4 has a developing section 4a having a developing roller 41 and a supply roller 42, and a developer storage section 4b that stores toner as a developer, which are separated from each other by a partition plate 55. The developing section 4a and the developer storage section 4b are connected to each other through an opening 44 provided in the partition plate 55. When the developing device 4 is in an unused state after being shipped from the factory, a sealing sheet 46 that prevents the toner from moving from the inside of the developer storage section 4b to the developing section 4a is disposed in the opening 44. As shown in FIG. 3(b), the sealing sheet 46 is fixed at a fixing section 47. In this embodiment, the other end 46a of the sealing sheet 46, which is opposite to the one end 46b fixed to the fixing section 47, is fixed and supported by an agitating member 45 that can rotate around an agitating shaft 45a for agitating the toner in the developer storage section 4b. However, the agitating member 45 may extend further beyond the fixed position. The agitating member 45 further supports an agitating sheet 54 that rotates with the rotation of the agitating member 45 to agitate and transport the toner. The sealing sheet 46 after being released from its fixing can also be used as the agitating sheet.

[0033] Polyethylene terephthalate was used as the material for the sealing sheet 46. The sealing sheet 46 was fixed by thermal welding. Alternatively, ultrasonic welding, for example, may be used. When the process cartridge including the developing device 4 is used for the first time, the process cartridge is mounted on the image forming apparatus main body, and then the stirring member 45, to which a driving force is transmitted from the main body, rotates in the R3 direction, causing the sealing sheet 46 to come off the opening 44. Thereafter, the stirring member 45 rotates, causing the stirring sheet 54 and the sealing sheet 46 to stir the toner inside the developer accommodating portion 4b, thereby supplying the toner from the developer accommodating portion 4b to the developing portion 4a.

[0034] 3(b) is an enlarged view of the periphery of the opening in a state where the sealing sheet 46 is fixed. As the stirring member 45 rotates in the R3 direction, a convex portion 48 is formed downstream of the fixed portion 47 in the R4 direction (second direction) in which the sealing sheet 46 is detached from the fixed portion 47. 3(b) is a view showing a plane including the opening 44 as viewed from the R5 direction in a state where the sealing sheet 46 has been removed. As shown in FIG. 3(c), the protrusions 48 are formed in a continuous state in the direction in which the rotation shaft of the agitating member 45 extends (the direction in which the shaft of the developing roller 41 extends). The direction in which the sealing sheet 46 comes off the fixed portion is a direction intersecting (typically perpendicular to) the direction in which the rotation shaft of the agitating member 45 extends. The direction in which the rotation shaft of the agitating member 45 extends is called the first direction, and the direction in which the protrusions 48 are formed, which intersects with the first direction, is called the second direction.

[0035] The method for manufacturing the protrusions 48 is not particularly limited, and for example, the protrusions 48 may be molded integrally with the partition plate 55, or a separate member may be attached after the partition plate 55 is manufactured. The method for attaching the separate member may also be any method, such as by adhesive or thermal bonding. The protrusions 48 may also be formed on the partition plate 55 using a resin or the like. The material of the protrusions 48 is also not particularly limited, but it is preferable that the protrusions 48 are made of the same material as the developing device 4, and for example, polystyrene or polyacetal can be used.

[0036] [Comparative Example] 10 shows a configuration of a developing device 4 according to a conventional technique as a comparative example. As shown in Fig. 10(b) and Fig. 10(c), the comparative example is different from Example 1 in that a partition plate 55 is not provided with a protrusion 48.

[0037] <Comparison between Example 1 and Comparative Example> As a result of intensive research, the inventors have confirmed that the torque required to open the sealing sheet 46 in Example 1 is lower than that in the comparative example. The reason for this is believed to be as follows, which will be described with reference to Figs. 4 and 5.

[0038] 4 shows a schematic cross-sectional view when the sealing sheet 46 is welded to the welding seat surface. In order to weld the sealing sheet, the welding horn heated to a predetermined temperature operates in the order of FIG. 4(a) → FIG. 4(b) → FIG. 4(c). At this time, the welding seat surface is welded, and is deformed as shown in FIG. 4(b), forming unevenness, and the sealing sheet 46 is fixed to the fixing portion 47. Then, the welding horn is separated from the sealing sheet 46, and the fixing portion 47 is fixed to the sealing sheet 46 as a recess recessed from the partition plate 55, and fixing position protrusions 47a protruding from the partition plate 55 on both sides of the fixing portion 47 are formed.

[0039] Fig. 5 shows how the sealing sheet 46, which has been fixed to the fixing portion 47 with the unevenness formed thereon, is removed from the fixing portion 47 and opened. Fig. 5 is an enlarged cross-sectional view of the sealing sheet 46, the fixing portion 47, the protrusion 48, and the vicinity thereof. Figs. 5(a) and 5(b) show Example 1, and Figs. 5(c) and 5(d) show a comparative example. Figs. 5(a) and 5(c) show how the sealing sheet 46 is fixed to the fixing portion 47, and Figs. 5(b) and 5(d) show how force is applied when opening the sealing sheet 46 (shown by a dotted line).

[0040] When the sealing sheet 46 of Example 1 is opened, as shown in Fig. 5(a), first, a force F1 is transmitted to the sealing sheet 46 by the rotation of the stirring member 45. Then, as shown in Fig. 5(b), since the sealing sheet is supported by the convex portion 48, a force F2 is transmitted to a position P2 via a position P1. Then, at the position P2, a component force F3 of the force F2 acts as a force to peel the sealing sheet 46 from the welding seat surface.

[0041] On the other hand, in the configuration of the comparative example, the force transmitted is smaller than in the case of Example 1. The reason for this will be described with reference to Figures 5(c) and (d). As shown in Figure 5(c), a force f1 is first transmitted to the sealing sheet 46 due to the rotation of the stirring member 45. Here, unlike the case of Example 1, as shown in Figure 5(d), the force f1 is divided into a force f2 and a component force f2' at position p1, and the component force f2' acts as a force to peel the sealing sheet 46 from the welding seating surface. The force f2 is divided into a force f3 and a component force f3' at position p2, and the component force f3' acts as a force to peel the sealing sheet 46 from the welding seating surface. In other words, in the comparative example, a component force f2' acts at position p1 in a direction different from the direction connecting positions p1 and p2, resulting in a loss of force compared to that in the case of Example 1. As a result, it is considered that the torque required for opening is smaller in Example 1 than in the comparative example. In particular, as a result of intensive research by the inventors, it was found that the difference in torque becomes more pronounced as the amount of toner in the toner storage section increases. It is believed that the reason for this is that the sealing sheet 46 is deformed into a shape similar to that shown in FIG. 5(c) due to the weight of the toner.

[0042] As described above, in this embodiment, the developing device 4 has the developing unit 4a and the developer container 4b, and when the developing device 4 is mounted on the image forming apparatus 100, the developer container 4b is located above the developing unit 4a in the direction of gravity. When the opening 44 is provided in the partition member that divides the developer storage section 4b, a convex portion 48 is provided downstream of the fixing portion 47 and upstream of the opening 44 in the direction in which the sealing sheet 46 is removed by the rotation of the stirring member 45. Furthermore, the convex portion 48 is preferably configured to extend in a direction along the rotation axis of the stirring member 45. This makes it possible to reduce the torque required to peel off the sealing sheet 46 in this embodiment. In particular, when the developer storage section 4b is filled with toner and weight is applied to the sealing sheet 46, the effect of reducing the required torque is enhanced.

[0043] It is more preferable that the top of the convex portion 48 is pointed rather than flat. Since the presence of the convex portion 48 itself has the effect of reducing torque, the height of the convex portion 48 is not necessarily limited to a certain range. However, it is preferable that the height of the convex portion 48 is higher than the height of at least a part of the fixing position convex portion 47a. Also, as shown in FIG. 5, if the height of the convex portion 48 from the partition plate 55 is approximately the same as the height of the fixing position convex portion 47a of the fixing portion 47 from the partition plate 55, the effect is easily obtained, and for example, the height of the convex portion 48 may be set within a predetermined range from the height of the fixing position convex portion 47a. As an example of the predetermined range, the upper limit of the height of the convex portion 48 is +20% or less from the height of the fixing position convex portion 47a. If the height of the convex portion 48 exceeds +20% of the height of the fixing position convex portion 47a, the sealing property may be reduced. As for the lower limit of the height of the convex portion 48, even if a convex portion is provided, an effect corresponding to the height of the convex portion 48 can be obtained.

[0044] [Example 2] Next, a second embodiment of the present invention will be described with reference to the drawings. Explanations of the same parts as in the first embodiment will be omitted. In the second embodiment, as shown in FIG. 6(c), the protrusions 48 provided on the partition plate 55 are discontinuous and partially absent.

[0045] In the present embodiment, compared to Example 1, the torque reduction amount is small due to the presence of discontinuous portions in the protruding portion 48. However, compared to the comparative example, the torque at the time of opening can be reduced by providing the protruding portion 48 downstream of the fixing portion 47 in the direction of peeling off the sealing sheet 46. That is, it is not necessary to provide the protruding portion 48 connected in series at all positions downstream of the fixing portion 47 and upstream of the opening 44 in the direction of peeling off the sealing sheet 46. In other words, the shape of the protruding portion 48 does not have to be continuous, and may be intermittent. Typically, a plurality of protruding portions 48 are provided with gaps between them. By providing the protruding portion 48 at least at some position downstream of the fixing portion 47, the effect of reducing the torque at the time of opening can be obtained, although to a greater or lesser extent.

[0046] [Example 3] Next, a third embodiment of the present invention will be described with reference to the drawings. Explanations of the same parts as in the first and second embodiments will be omitted. The third embodiment shows an example that is particularly suitable for use with a recycled developing device 4. The third embodiment differs from the first embodiment in that the protrusions 48 are connected in a continuous manner so as to surround the outer periphery of the opening 44, as shown in Figs. 7(b) and (c).

[0047] In the third embodiment, as shown in Fig. 7(a), the developer storage chamber 4b is manufactured by assembling and fixing a first storage chamber member 4b1 and a second storage chamber member 4b2, which are separate parts. Fig. 8(a) shows the agitation member 45 and the agitation shaft 45a used in the developing device 4. Figs. 8(b) and 8(c) show a state in which a first agitation shaft holder 49a is attached to the first storage chamber member 4b1 and a second agitation shaft holder 49b is attached to the second storage chamber member 4b2 in order to hold the agitation shaft 45a.

[0048] In Example 3, a used developing device 4 is reused. Specifically, the protrusion 48 was the adhesion portion of the sealing sheet 46 in the (non-recycled) developing device 4 at the time of the first use. Then, when reused, the protrusion 48 functions as the protrusion 48 for reducing the torque.

[0049] Here, since it may be difficult to increase the torque of the main body when reused, it is preferable that the required torque for opening the developing device 4 when reused is equal to or less than the torque when opening the device for the first time. In addition, in conventional recycled products, in order to stabilize the sealing performance, the welding surface is formed so as to cover the fixed portion of the first welding seat surface once. Therefore, the area of ​​the welding surface when reused is large. As a result, there is a concern that the opening torque of the sealing sheet may increase.

[0050] On the other hand, in this example, in the recycled product, the fixing portion 47 is formed on the outside of the convex portion formed by the first fixing portion, and the first fixing portion functions as the convex portion 48, so that the opening torque can be equal to or less than that of the first time even when reused. In other words, even when reused, high toner sealing performance can be obtained while suppressing an increase in the opening torque.

[0051] Furthermore, the developer storage section 4b is configured to be easily separated into the first storage chamber member 4b1 and the second storage chamber member 4b2, and the first storage chamber member 4b1 and the second storage chamber member 4b2 hold the stirring member. Therefore, when recycling, it is easy to clean the developer storage section and remove the stirring member. In particular, if there is toner residue on the welding seat surface, the sealing performance at the time of welding of the sealing sheet is reduced, but in this example, it is easy to clean and high toner sealing performance can be obtained.

[0052] In this embodiment, on the premise that the developing device 4 is reused, a configuration is adopted in which the protrusion 48 (the fixed part at the time of first use, i.e., when the developing device is not recycled) around the opening 44 in the partition plate 55 is provided with the fixed part 47 around it. However, a configuration may be adopted in which the protrusion 48 is provided around the opening 44 and the fixed part 47 is provided around it even when the developing device is not recycled. In this embodiment, the developer storage part 4b is easily disassembled and assembled by using the first storage chamber member 4b1 and the second storage chamber member 4b2. Such an assembly configuration may be used in combination with the configuration of the protrusion 48 and the fixed part 47 of this embodiment, or may be used alone.

[0053] [Example 4] Next, in Example 4, an example in which the stirring member 45 is different from that in Example 3 will be described with reference to FIG. 9. The stirring member 45 of this example shown in FIG. 9 includes a central fixing portion 56a located in the central portion in the first direction and an end fixing portion 56b located at an end in the first direction for fixing the sealing sheet 46. Here, the length of the end fixing portion 56b in the second direction is shorter than the length of the central fixing portion 56a in the second direction. As a result, the free length of the sealing sheet 46 is shorter for the end fixing portion 56b than for the central fixing portion 56a, so that the torque for opening the end of the sealing sheet 46 can be reduced.

[0054] In addition, in this embodiment, in the center of the stirring member 45, a surface formed by the center fixing portion 56a (the upper surface in the figure) and a surface on the upstream side of the surface formed by the center fixing portion 56a in the rotation direction R3 (the upper surface in the figure) are In the present embodiment, a corner surface 56c is formed between the right side surface 56d) of the stirring member 45 and the end fixing portion 56b. The corner surface 56c is a chamfered portion of the stirring member 45, and is indicated by hatching. In this embodiment, by providing such a corner surface 56c, the phase when the stirring shaft 45a rotates can be dispersed by the end fixing portion 56b, the center fixing portion 56a, and the corner surface 56c, and the maximum torque can be reduced. That is, compared with the conventional configuration shown in the cross-sectional view of FIG. 9(b), according to the configuration of this embodiment as shown in FIG. 9(c), during stirring, a force is applied at the end portion with the right end of the end fixing portion 56b in the X direction as a fulcrum, and at the center portion, a force is applied with the lower end 56e of the corner surface 56c as a fulcrum rather than the end of the center fixing portion 56a, so that the timing of the force application can be shifted and the total required torque can be reduced.

[0055] [Configuration 1] A developing device that can be attached to an image forming apparatus, a developer storage section for storing a developer; a developing section having a rotatable developer carrier that carries a developer; a stirring member disposed in the developer container and configured to stir the developer contained therein; having the developer container and the developing unit are connected via an opening, before the developing device is mounted on the image forming apparatus, a sealing sheet connected to the stirring member is fixed to a fixing portion around the opening, thereby sealing the opening, After the developing device is mounted on the image forming apparatus, the stirring member operates to separate the sealing sheet from the fixed portion, thereby connecting the developer accommodating portion and the developing portion. 1. A developing device comprising: a convex portion is provided downstream of the fixing portion and upstream of the opening in a second direction intersecting with a first direction in which a rotation shaft of the stirring member extends, The height of the protrusion is higher than the height of at least a part of the fixing position protrusions formed at the fixing position. A developing device characterized by the above. [Configuration 2] The protrusions are provided in a continuous manner in the first direction. 2. The developing device according to claim 1, [Configuration 3] The protrusions are provided in a plurality of positions with gaps therebetween in the first direction. 2. The developing device according to claim 1, [Configuration 4] The protrusion is provided in a continuous manner so as to surround the opening, The fixing portion is provided around the protrusion. 4. The developing device according to any one of configurations 1 to 3. [Configuration 5] the developing device is a remanufactured product, The protruding portion is a fixing portion that was used to fix the sealing sheet when the developing device was a non-recycled product. 5. The developing device according to configuration 4. [Configuration 6] The fixing position protrusions are portions formed on both sides of the fixing portion in the second direction by protruding when the sealing sheet is fixed, The height of the protrusion is within a predetermined range from the height of the fixing position protrusion. 6. The developing device according to any one of configurations 1 to 5. [Configuration 7] The stirring member has a fixing portion that fixes the sealing sheet, The developing device described in any one of configurations 1 to 6, characterized in that an end fixing portion located at an end in the first direction among the fixing portions has a shorter length in the second direction than a central fixing portion located in the center in the first direction. [Configuration 8] 8. The developing device according to claim 7, wherein the central fixing portion of the agitating member has a rotation phase different from that of the end fixing portions. [Configuration 9] After the developing device is attached to the image forming apparatus and the sealing sheet is detached from the fixing portion, the sealing sheet rotates in association with the rotation of the stirring member, thereby functioning as a sheet for stirring the developer contained in the developer containing portion. 9. The developing device according to any one of configurations 1 to 8. [Configuration 10] The stirring member has a stirring sheet for stirring the developer contained in the developer container. 9. The developing device according to any one of configurations 1 to 8. [Explanation of symbols]

[0056] 4...developing device, 41...developing roller, 4a...developing portion, 4b...developer storage portion, 44...opening, 45...agitating member, 46...sealing sheet, 47...fixing portion, 48...projection portion, 100...image forming apparatus

Claims

1. A developing device that can be attached to an image forming apparatus, a developer storage section for storing a developer; a developing section having a rotatable developer carrier that carries a developer; a stirring member disposed in the developer container and configured to stir the developer contained therein; having the developer container and the developing unit are connected via an opening, before the developing device is mounted on the image forming apparatus, a sealing sheet connected to the stirring member is fixed to a fixing portion around the opening, thereby sealing the opening, After the developing device is mounted on the image forming apparatus, the stirring member operates to separate the sealing sheet from the fixed portion, thereby connecting the developer accommodating portion and the developing portion.

1. A developing device comprising: a protruding portion is provided downstream of the fixing portion and upstream of the opening in a second direction intersecting with a first direction in which a rotation shaft of the stirring member extends, The height of the protrusion is higher than the height of at least a part of the fixing position protrusions formed at the fixing position. A developing device characterized by the above.

2. The protrusions are provided in a continuous manner in the first direction.

2. The developing device according to claim 1,

3. The protrusions are provided in a plurality of positions with gaps therebetween in the first direction.

2. The developing device according to claim 1,

4. The protrusion is provided in a continuous manner so as to surround the opening, The fixing portion is provided around the protrusion.

4. The developing device according to claim 1, wherein the developing device is a developing unit.

5. the developing device is a remanufactured product, The protruding portion is a fixing portion that was used to fix the sealing sheet when the developing device was a non-recycled product.

5. The developing device according to claim 4.

6. The fixing position protrusions are portions formed on both sides of the fixing portion in the second direction by protruding when the sealing sheet is fixed, The height of the protrusion is within a predetermined range from the height of the fixing position protrusion.

4. The developing device according to claim 1, wherein the developing device is a developing unit.

7. The stirring member has a fixing portion that fixes the sealing sheet, A developing device according to any one of claims 1 to 3, characterized in that an end fixing portion located at an end in the first direction among the fixing portions has a shorter length in the second direction than a central fixing portion located in the center in the first direction.

8. 8. The developing device according to claim 7, wherein the central fixing portion of the agitating member has a rotation phase different from that of the end fixing portions.

9. When the developing device is mounted on the image forming apparatus and the sealing sheet is detached from the fixing portion, the sealing sheet rotates in accordance with the rotation of the stirring member, thereby The developer contained in the developer sheet is stirred by the developer conveying member.

4. The developing device according to claim 1, wherein the developing device is a developing unit.

10. The stirring member has a stirring sheet for stirring the developer contained in the developer container.

4. The developing device according to claim 1, wherein the developing device is a developing unit.

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