Processing box

Abstract

The utility model discloses a processing box, which is detachably arranged on an image forming device and comprises a drum unit, a driving unit and a driving unit, a developing unit rotatably supporting a developing roller, the developing unit being movable between a contact position and a separation position with respect to the drum unit; the developing coupler is used for receiving the driving force of the image forming device to rotate and driving the developing unit to move from the separation position to the contact position under the action of torque; and the time delay mechanism is used for prolonging the time required by the developing unit to move from the separation position to the contact position. According to the processing box disclosed by the utility model, the developing unit can move from the separation position to the contact position only after the developing coupler receives driving force and the time delay mechanism is driven to operate, so that the time of the developing unit moving from the separation position to the developing position is prolonged, and the contact time point of the developing roller and the photosensitive drum is delayed; and the developing roller and the photosensitive drum can be contacted after completely rotating, so that the developing quality is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of image forming devices, in particular to a processing box. Background Art

[0002] The image forming device forms an image on a recording material using an electrophotographic imaging process, and the image forming device includes an electrophotographic copier, an electrophotographic printer (e.g., a laser beam printer, an LED printer), a fax machine, a word processor, etc. The image forming device includes an image forming device that forms an image by a contact development method, wherein the contact development method forms an image by performing a development process in a state where a developing component (developing roller) is in contact with a photosensitive drum, and in such an image forming device, the developing roller is pushed toward the photosensitive drum at a predetermined pressure during the development process, and contacts the surface of the photosensitive drum at a predetermined pressure. The processing box includes at least one of an electrophotographic photosensitive drum as an image bearing member and a processing device (developer bearing member (developing roller)) that can act on the drum, the electrophotographic photosensitive drum is arranged on a photosensitive frame, the processing device is arranged on the developing frame, and the electrophotographic photosensitive drum and the processing device are integrally constructed as a box that can be detachably mounted in the image forming device.

[0003] During the operation of the image forming device, the developing roller contacts and squeezes the photosensitive drum, so that the developer on the developing roller is transferred to the surface of the photosensitive drum where a specific electrostatic latent image is formed, thereby completing the developing process. When the image forming device stops working, the photosensitive drum and the developing roller need to be separated from each other to extend the service life of both.

[0004] An existing method for making the developing roller and the photosensitive drum go from separation to contact is to drive the developing roller to approach and contact the photosensitive drum through the torque generated by the rotation of the developing coupling. However, since the torque of the rotational force is large, the developing coupling will instantly drive the developing roller to contact the photosensitive drum upon receiving the driving force, but the photosensitive drum may not have fully rotated at this time. When the developing roller contacts the photosensitive drum and starts developing work without fully rotating, developing defects will occur, affecting the quality of development. Utility Model Content

[0005] According to one aspect of the utility model, there is provided a process cartridge which is detachably mounted on an image forming device, comprising:

[0006] A drum unit rotatably supports a photosensitive drum;

[0007] a developing unit rotatably supporting a developing roller, the developing unit being movable relative to the drum unit between a contact position at which the developing roller contacts the photosensitive drum and a separation position at which the developing roller separates from the photosensitive drum;

[0008] A developing coupling, provided at the developing unit, for receiving a driving force of the image forming device to rotate, and driving the developing unit to move from a separation position to a contact position under the action of a torque;

[0009] It also includes a delay mechanism for extending the time required for the developing unit to move from the separation position to the contact position.

[0010] In some embodiments, the delay mechanism includes a rotating member disposed on the developing unit and directly or indirectly receiving the driving force of the developing coupling to rotate, and a supporting portion and a matching portion disposed on the drum unit and matching with the rotating member.

[0011] In some embodiments, the rotating member includes a gear portion and a toothless portion connected and arranged along its circumference;

[0012] When the gear portion is directly or indirectly engaged with the developing coupling, the rotating member is driven to rotate;

[0013] When the rotating member rotates until the tooth-missing portion faces the developing coupling, the rotating member stops receiving the driving force.

[0014] In some embodiments, the rotating member includes a first column portion arranged along its axial direction, and an inwardly recessed avoidance portion is provided on the surface of the first column portion.

[0015] In some embodiments, when the support portion abuts against the surface of the first column portion, the developing roller is separated from the photosensitive drum;

[0016] When the rotating member rotates until the supporting portion faces the escape portion, the developing roller contacts the photosensitive drum.

[0017] In some embodiments, the supporting portion is disposed on an end cover of the drum unit, and the supporting portion is a convex column extending along a width direction of the process cartridge.

[0018] In some embodiments, the rotating member includes a second column portion arranged along its axial direction, and a notch portion is provided on the second column portion.

[0019] In some embodiments, the rotating member is disposed outside a driving-side bearing of the developing unit, and along the axial direction of the rotating member, the second column portion is farther from the driving-side bearing than the first column portion.

[0020] In some embodiments, at least a portion of the second column portion is embedded in the matching portion, and a protrusion matching with the notch portion is provided in the matching portion.

[0021] In some embodiments, the protrusion separates the mating portion into a first half and a second half that are connected;

[0022] When the second column portion moves between the first half portion and the second half portion, the notch portion rotates around the protrusion portion.

[0023] In some embodiments, when the developing unit is in the separated position, the second column portion is located in the second half;

[0024] When the developing unit moves from the separated position to the contact position, the second column portion moves from the second half to the first half.

[0025] In some embodiments, the mating portion is a strip hole or a strip groove provided on the end cover of the drum unit, the mating portion extends along the width direction of the processing box, and the protrusion is provided on an inner wall in the extension direction of the mating portion.

[0026] In some embodiments, the diameter of the first column portion is greater than the diameter of the second column portion.

[0027] In some embodiments, a first elastic member is further included, wherein the first elastic member is respectively connected to the developing unit and the drum unit, and applies a force to the developing unit to move from the contact position to the separation position.

[0028] The beneficial effects of the utility model are as follows: after the developing coupling of the utility model receives the driving force, the processing box needs to drive the delay mechanism to operate before the developing unit can move from the separation position to the contact position, which prolongs the time for the developing unit to move from the separation position to the developing position, and delays the time point when the developing roller contacts the photosensitive drum, which can ensure that the developing roller and the photosensitive drum are in contact only after they are fully rotated, thereby ensuring the quality of the development. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a processing box at an angle in some embodiments of the utility model;

[0030] Figure 2 It is a schematic structural diagram of a processing box from another angle in some embodiments of the utility model;

[0031] Figure 3 (a) and (b) are schematic structural diagrams of the drive side end cover of the process cartridge according to some embodiments of the present invention;

[0032] Figure 4 (a) and (b) are schematic structural diagrams of a rotating member of a process cartridge according to some embodiments of the present invention;

[0033] Figure 5 A side view of a developing unit in some embodiments of the present invention when the developing unit is in a separated position;

[0034] Figure 6It is a schematic diagram of the cooperation between the driving side end cover and the rotating member when the developing unit of some embodiments of the utility model is in the separated position;

[0035] Figure 7 A bottom view of the process cartridge of some embodiments of the utility model when the developing unit is in a separated position;

[0036] Figure 8 It is a partial structural schematic diagram of the process cartridge of some embodiments of the utility model when the developing unit is in the contact position;

[0037] Fig. 9 It is a schematic diagram of the cooperation between the driving side end cover and the rotating member when the developing unit of some embodiments of the utility model is in the contact position;

[0038] Fig.10 A bottom view of the process cartridge of some embodiments of the present invention when the developing unit is in a contact position. DETAILED DESCRIPTION

[0039] The utility model is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0040] It should be noted that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] In the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "fixation" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0043] In the above description, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0044] The following descriptions of directions are as follows:

[0045] The directions A1 and A2 are the first directions, the direction indicated by A1 is the positive direction of the first direction, and the direction indicated by A2 is the negative direction of the first direction;

[0046] The directions B1 and B2 are the second direction, the direction indicated by B1 is the positive direction of the second direction, and the direction indicated by B2 is the negative direction of the second direction;

[0047] The directions of C1 and C2 are the third direction, the direction pointed by C1 is the positive direction of the third direction, and the direction pointed by C2 is the negative direction of the third direction.

[0048] The first direction, the second direction and the third direction intersect each other.

[0049] like Figure 1 and Figure 2As shown, this embodiment provides a processing box 100, including a developing unit 10, a drum unit 20 and a driving assembly. The developing unit 10 includes a developing frame 11, a developing roller 16, a powder feeding roller, a stirring frame and a powder discharge knife. The drum unit 20 includes an end cover, a photosensitive frame 21, a photosensitive drum 22 and a charging roller. The processing box is roughly in the shape of a rectangular box, and the first direction (A1 and A2 directions) is the length direction of the processing box 100, the second direction (B1 and B2 directions) is the width direction of the processing box 100, and the third direction (C1 and C2 directions) is the height direction of the processing box 100; one end of the processing box in the A1 direction is a driving end, and one end in the A2 direction is a conductive end, the developing unit 10 and the drum unit 20 are arranged opposite to each other in the second direction (width direction), the direction from the developing unit 10 toward the drum unit 20 is the B1 direction, one end of the processing box along the B1 direction is the front end, the direction from the drum unit 20 toward the developing unit 10 is the B2 direction, one end along the B2 direction is the rear end, one end of the processing box along the C1 direction is the upper end, and one end along the C2 direction is the lower end.

[0050] like Figure 1 and Figure 2 As shown, the developing frame 11 forms a powder bin for storing toner, and the developing frame 11 is roughly in the shape of a long box. The developing frame 11 is provided with a driving side bearing 12 and a conductive side bearing at both ends of the length direction (along the first direction), respectively. The stirring frame, the powder feeding roller, and the developing roller 16 are rotatably supported on the driving side bearing 12 and the conductive side bearing at both ends of the length direction of the developing frame 11. The stirring frame, the powder feeding roller, and the developing roller 16 can rotate under the action of the driving unit, and the axial directions (along the first direction) of the stirring frame, the powder feeding roller, and the developing roller 16 are all arranged along the length direction of the developing frame 11. The toner in the powder bin is stirred by the stirring frame to prevent the toner in the powder bin from agglomerating, and the toner can also be transported to the direction of the powder feeding roller. The powder feeding roller transports the toner to the developing roller 16 and is adsorbed by the charged developing roller 16.

[0051] like Figure 1 and Figure 2 As shown, the photosensitive frame 21 also has a length direction, which is consistent with the length direction of the developing frame 11 (along the first direction), and the photosensitive drum 22 is rotatably supported at both ends of the photosensitive frame 21 in the length direction. Specifically, the photosensitive drum 22 is arranged on the lower end side (one end in the C2 direction) in the height direction (third direction) of the photosensitive frame 21. The toner adsorbed by the developing roller 16 is transferred to the photosensitive drum 22 through the potential difference between the developing roller 16 and the photosensitive drum 22. The toner on the photosensitive drum 22 is then transferred through the transfer belt of the image forming device to form an image on the recording material (such as paper). The charging roller is used to charge the surface of the photosensitive drum 22 with a uniform charge, so that the photosensitive drum 22 can adsorb the toner.

[0052] like Figure 1 and Figure 2As shown, the driving assembly includes a photosensitive coupling 31, a developing coupling 32, a developing roller gear 33, a powder feeding roller gear, and a stirring frame gear. The driving assembly can be arranged at one or both ends of the processing box 100 in the length direction. In this embodiment, the driving assembly is arranged at the driving end (the end in the A1 direction) of the processing box 100 in the length direction. The photosensitive coupling 31 is fixedly arranged at the driving end of the photosensitive drum 22 in the length direction. The photosensitive coupling 31 and the photosensitive drum 22 can be integrally formed or split structures. The photosensitive coupling 31 is used to engage with the driving head of the image forming device, thereby receiving the rotational driving force of the image forming device and driving the photosensitive drum 22 to rotate. The end of the photosensitive coupling 31 away from the end face of the photosensitive frame is provided with an engaging head. The engaging head can be a regular or irregular protrusion, as long as it can engage with the photosensitive driving head and stably receive the driving force.

[0053] like Figure 1 and Figure 2 As shown, the developing coupling 32, the developing roller gear 33, the powder feeding roller gear, and the stirring frame gear are arranged on the outer side of the driving side bearing 12. Specifically, the driving side bearing 12 is provided with a supporting hole for supporting the developing coupling 32, and the developing coupling 32 is used to mesh with the driving head of the image forming device and receive the driving force; the developing roller gear 33 is sleeved on the end of the shaft of the developing roller 16 extending from the driving side bearing 12, the powder feeding roller gear is sleeved on the end of the shaft of the powder feeding roller extending from the driving side bearing 12, and the stirring frame gear is sleeved on the end of the stirring frame extending from the driving side bearing 12. The developing roller gear 33, the powder feeding roller gear and the stirring frame gear are directly or indirectly meshed with the developing coupling 32 to transmit the driving force received by the developing coupling 32, thereby driving the developing roller 16, the powder feeding roller and the stirring frame to rotate.

[0054] like Figure 1 As shown, a developer cover 15 is also provided on the outside of the driving side bearing 12, and the developer cover 15 covers the developer roller gear 33, the powder feeding roller gear, the stirring rack gear and a part of the developer coupling 32, and can protect the driving components. Specifically, a cylindrical portion is provided on the developer cover 15, and the cylindrical portion protrudes along the side away from the developer frame 11, and the inside of the cylindrical portion is hollow, and its axial direction extends along the length direction of the developer frame. When the meshing portion of the developer coupling 32 protrudes outward along the axial direction, a part of it passes through the inside of the cylindrical portion and protrudes out of the developer cover 15.

[0055] like Figure 1 and Figure 2As shown, the end covers are arranged at both ends of the process box 100 in the length direction, and the developing unit 10 and the drum unit 20 are movably connected through the end covers. The end covers include a driving side end cover 41 and a conductive side end cover 42. The conductive side end cover 42 is arranged outside the conductive side bearing, and the driving side end cover 41 is arranged outside the developing protective cover 15. When observed along the length direction (first direction) of the process box 100, the driving side end cover 41 and the developing protective cover 15 at least partially overlap. The driving side end cover 41 and the conductive side end cover 42 cover at least a part of the end of the photosensitive frame 21 and the developing frame 11 respectively. The driving side end cover 41 is fixedly connected to the end of the photosensitive frame 21, and the driving side end cover 41 and the photosensitive frame 21 can be arranged as one piece.

[0056] like Figure 1 and Figure 3 As shown, in this embodiment, the driving side end cover 41 is provided with a first through hole 414 and a second through hole 415. When the driving side end cover 41 is mounted on the end of the developing frame 11 and the photosensitive frame 21, the photosensitive coupling 31 is exposed through the first through hole 414, and the developing coupling 32 is exposed through the second through hole 415, so that the coupling engages with the driving head of the image forming device to receive the driving force. On one side of the developing frame 11, the developing coupling 32, the cylindrical portion, and the second through hole 415 are coaxially arranged, and at least a portion of the cylindrical portion is inserted into the second through hole 415.

[0057] During the operation of the image forming device, the developing roller 16 and the photosensitive drum 22 need to be in close contact. When the image forming device is not working, the developing roller 16 and the photosensitive drum 22 need to be separated by a certain distance to avoid long-term contact between the developing roller 16 and the photosensitive drum 22, which may cause the photosensitive drum 22 to be contaminated by excess developer attached to the developing roller 16, the developing roller 16 to be deformed, and the photosensitive drum 22 to be worn.

[0058] Therefore, the developing unit 10 in this embodiment is configured to be movable relative to the drum unit 20, so that the developing roller 16 and the photosensitive drum 22 can be in contact when the image forming apparatus is in operation and separated when not in operation. When the process cartridge 100 is installed in the image forming apparatus, the drum unit 20 abuts against components in the image forming apparatus, thereby fixing the drum unit 20, and the developing unit 10 is configured to be movable relative to the drum unit 20 between a contact position and a separation position. When the developing unit 10 is in the contact position, the developing roller 16 is in contact with the photosensitive drum 22; when the developing unit 10 is in the separation position, the developing roller 16 is separated from the photosensitive drum 22.

[0059] In this embodiment, the movement mode of the developing unit 10 is to swing with the axis of the developing coupling 32 as the rotation center, that is, when the developing unit 10 is located in the contact position, the lower end of the developing unit 10 is close to the lower end of the drum unit 20, so that the developing roller 16 can contact the photosensitive drum 22. At this time, the upper end of the developing unit 10 is located away from the drum unit 20; when the developing unit 10 moves from the contact position to the separation position, the lower end of the developing unit 10 swings in the direction away from the drum unit 20, driving the developing roller 16 to separate from the photosensitive drum 22. At this time, the upper end of the developing unit 10 swings in the direction close to the drum unit 20.

[0060] like Figure 1 As shown, during the transportation and storage stage before the use of the processing box, it is also necessary to avoid long-term contact between the developing roller 16 and the photosensitive drum 22. In this embodiment, the processing box also includes a first elastic member 61. The first elastic member 61 can be a torsion spring. The coil portion of the torsion spring is sleeved on the support 413 of the driving side end cover 41. One end of the torsion spring abuts against the driving side end cover 41, and the other end abuts against the developing cover 15. In the initial state, due to the torsion force of the torsion spring acting on the developing unit 10, the lower end of the developing unit 10 is away from the lower end of the drum unit 20, and the photosensitive drum 22 is not in contact with the developing roller 16. When the developing unit 10 moves from the separation position to the contact position, the first elastic member 61 is deformed by the force.

[0061] Further, such as Figure 2 As shown, the processing box also includes a second elastic member 62, which is arranged between the developing frame 11 and the photosensitive frame 21. The second elastic member 62 can be a compression spring. The force of the second elastic member 62 can make the lower end of the developing unit 10 move toward the direction close to the photosensitive drum 22, that is, the developing roller 16 has a tendency to contact the photosensitive drum 22, but because the force of the first elastic member 61 is greater than the force of the second elastic member 62, the photosensitive drum 22 and the developing roller 16 are in a separated state when the processing box is in the initial state. Optionally, the first elastic member and the second elastic member can also be other forms of elastic elements, and the elastic force generated can be tension, pressure, torsion, etc.

[0062] like Figure 3 As shown, in this embodiment, the processing box also includes a delay mechanism for extending the time required for the developing unit 10 to move from the separation position to the contact position. The delay mechanism includes a supporting portion 411, a matching portion 412 and a rotating member 5. The rotating member 5 can directly or indirectly receive the driving force of the developing coupling to rotate. The supporting portion 411 and the matching portion 412 are both used to cooperate with the rotating member 5 to achieve delay.

[0063] like Figure 3As shown, the support portion 411 is arranged on the driving side end cover 41, and the support portion 411 is a convex column, which extends along the width direction (B1 and B2 directions) of the processing box 100. Specifically, the connecting end of the convex column is arranged on the outer circumferential surface of the first through hole 414, and the free end of the convex column extends in the direction toward the developing unit 10 (extending along the B2 direction). The convex column can be in the shape of a cylinder, a prism, etc., and the free end of the convex column can be set to an arc surface, a spherical surface, etc.

[0064] Further, such as Figure 3 As shown, the matching portion 412 is arranged on the driving side end cover 41. In the third direction, the matching portion 412 is arranged close to the lower part of the driving side end cover 41, that is, it is located at the lower side of the second through hole 415. In the second direction, the matching portion 412 is located on the rear side of the first through hole 414 (the side of the B2 direction), and the matching portion is also located on the rear side of the support portion 411. The mating portion 412 is a through groove or a through hole, and the extension direction of the mating portion 412 is along the direction toward the developing unit 10 (extending along the B2 direction), that is, the mating portion 412 is a strip groove or a strip hole (the extension direction of the strip groove or the strip hole is its length direction), and a protrusion 4121 is provided on an inner wall of the mating portion 412 (specifically an inner wall in the extension direction). Preferably, the protrusion 4121 is arranged on the upper wall of the mating portion 412 and protrudes downward, but only protrudes to approximately half the height of the mating portion 412 in the third direction, and does not contact the lower wall of the mating portion 412, thereby dividing the mating portion 412 along its length direction (extension direction) into a connected first half 4122 and a second half 4123, wherein in the second direction, the first half 4122 is closer to the photosensitive drum 22 than the second half 4123, that is, the first half 4122 is located on the B1 direction side of the second half 4123.

[0065] like Figure 1 and Figure 4 As shown, in this embodiment, the rotating member 5 is arranged on the developing unit 10, and can receive the driving force of the driving assembly to rotate. Specifically, a pillar is provided on the driving side bearing 12, and the rotating member 5 is rotatably supported on the pillar. The rotating member 5 is arranged near the lower end of the developing unit 10 in the height direction (third direction). Observed along the length direction (first direction) of the process cartridge, the rotating member 5 has an overlapping portion with the matching portion 412 on the driving side end cover 41.

[0066] like Figure 4As shown, the rotating member 5 includes a mounting portion 51, a gear portion 52, a toothless portion 53, a first column portion 54, and a second column portion 55. The mounting portion 51, the gear portion 52, the first column portion 54, and the second column portion 55 are sequentially arranged along the axial direction (i.e., the first direction) of the rotating member 5, and the mounting portion 51 is closest to the driving side bearing 12, and the second column portion 55 is farthest from the driving side bearing 12. The mounting portion 51 is a hole or a groove, which cooperates with a pillar provided on the driving side bearing 12 to rotatably mount the rotating member 5 on the driving side bearing 12.

[0067] like Figure 4 As shown, the gear portion 52 and the toothless portion 53 are connected and arranged along the circumference of the rotating member 5, that is, the gear portion 52 and the toothless portion 53 are located in the same circumference, and the gear portion 52 is used to mesh with the developing roller gear 33 in the driving assembly to receive the driving force to rotate. Optionally, the gear portion 52 can also be configured to mesh with the powder feeding roller gear or the developing coupling, which can also achieve the effect of making the rotating member 5 receive the driving force to rotate. The gear portion 52 can be helical teeth or straight teeth. The toothless portion 53 is a portion without teeth, that is, the position corresponding to the toothless portion 53 is a smooth circumferential surface. When the rotating member 5 rotates to the point where the toothless portion 53 is opposite to the developing roller gear 33, that is, when the gear portion 52 is out of mesh with the developing roller gear 33, the rotating member 5 can no longer receive the driving force of the developing roller gear 33, and the rotating member 5 will stop rotating.

[0068] like Figures 4 to 10 As shown, the first column portion 54 is located on the side of the gear portion 52 away from the drive side bearing 12 in the axial direction of the rotating member 5, and the first column portion 54 is roughly cylindrical. An inwardly recessed escape portion 56 is provided on the circumferential surface of the first column portion 54, and the escape portion 56 is an arc groove recessed from the circumferential surface of the first column portion 54 toward its axial direction (i.e., recessed along the radial direction). In the initial state, when the developing unit 10 is in the separation position, the circumferential surface of the first column portion 54 does not contact the support portion 411 and there is a certain interval; in the process of the developing unit 10 moving from the separation position to the contact position, the circumferential surface of the first column portion 54 contacts the support portion 411 on the drive side end cover 41, and as the rotating member 5 rotates, the support portion 411 slides on the circumferential surface of the first column portion 54, and finally slides to the escape portion 56 to abut against the support portion 411, at which time the developing unit 10 reaches the contact position.

[0069] like Figures 4 to 10As shown, the second column 55 is located on the side of the first column 54 away from the driving side bearing 12 in the axial direction of the rotating member 5. The second column 55 is roughly cylindrical, and the diameter of the second column 55 is smaller than the diameter of the first column 54. A notch 57 that is recessed inward is provided on the circumferential surface of the second column 55. The notch 57 can be formed by cutting off a part of a fan-shaped cross section on the second column 55. The central angle of the notch 57 is preferably 90°, or other angles. During assembly, the second column 55 is inserted into the first half 4122 or the second half 4123 of the matching portion 412, and the position of the notch 57 corresponds to the position of the protrusion 4121. When the second column 55 moves between the first half 4122 and the second half 4123, the notch 57 rotates around the protrusion 4121. When the processing box is in the initial state, that is, when the developing unit 10 is in the separated position, the second column portion 55 is located in the second half portion 4123; when the developing unit 10 moves from the separated position to the contact position, the second column portion 55 moves from the second half portion 4123 to the first half portion 4122. During the movement of the second column portion 55, the cooperation between the notch portion 57 and the protrusion portion 4121 can play a limiting role.

[0070] like Figures 1 to 10 As shown, when developing work is required, the developing drive head of the image forming device is engaged with the developing coupling 32 of the developing unit 10, and the developing coupling 32 receives the driving force and starts to rotate, driving the developing roller gear 33 to rotate, and the developing roller gear 33 then drives the transmission member 51 to rotate. Due to the large torque and friction of the driving force (when the developing drive head is engaged with the developing coupling 32, a part of the developing drive head will contact the developing cover 15, and friction will be generated between the two when the developing drive head rotates), a force can be generated to move the developing unit 10 from the separation position to the contact position (this force can overcome the force of the first elastic member 61 and cause the first elastic member 61 to deform), that is, the lower end of the developing unit 10 moves in the direction close to the lower end of the drum unit 20 (direction B1), and the rotating member 5 receives the driving force of the developing roller gear 33 and rotates in the same direction. The developing unit 10 moves toward the drum unit 20 to a position where the circumferential surface of the first column portion 54 contacts the support portion 411. At this time, the developing roller 16 has not yet contacted the photosensitive drum 22. The rotating member 5 continues to rotate under the action of the driving force. When the rotating member 5 rotates to the point where the toothless portion 53 is opposite to the developing roller gear 33, the support portion 411 also slides along the circumferential surface of the first column portion 54 to a position opposite to the avoidance portion 56. At the same time, the notch portion 57 of the second column portion 55 rotates around the protrusion 4121 from the second half portion 4123 to the first half portion 4122. Since the avoidance portion 56 is recessed inwardly, the lower end of the developing unit 10 moves further toward the direction (B1 direction) close to the photosensitive drum 22 under the action of the torque of the driving force, the friction force, and the elastic force of the second elastic member 66, so that the developing roller 16 contacts the photosensitive drum 22.

[0071] In the above process, there is a certain delay time before the developing roller 16 contacts the photosensitive drum 22 due to the effect of the delay mechanism, namely, the time required for the rotating member 5 to rotate through the stroke of the gear portion 52, the time required for the support portion 411 to slide from the circumferential surface of the first column portion 54 to the position opposite to the avoidance portion 56, and the time required for the second column portion 55 to rotate from the second half 4123 of the matching portion 412 to the first half 4122. The time of these three is the same. After this delay time, the developing roller 16 further approaches the photosensitive drum 22 and contacts it, instead of the developing coupling 32 moving to the contact position under the action of torque when receiving the driving force. Through such an arrangement, the time required for the developing unit 10 to move from the separation position to the contact position is extended, so that when the developing roller 16 contacts the photosensitive drum 22, the photosensitive drum 22 has been fully rotated, thereby avoiding the developing roller 16 from contacting the photosensitive drum 22 too early. The photosensitive drum 22 contacts the developing roller 16 before it is fully rotated, which will cause printing defects during the developing operation. Delaying the time point of contact between the two can ensure the quality of the developing.

[0072] When the image forming device finishes the developing work, the developing drive head of the image forming device stops rotating, the developing driving force disappears, the first elastic member 61 deforms and recovers to exert force on the developing unit 10, driving the developing unit 10 to rotate in the direction away from the photosensitive drum 22 (along the B2 direction) to the separation position, the developing roller 16 separates from the photosensitive drum 22, and the rotating member 5 follows the developing unit 10 to move in the B2 direction. Since the movement of the rotating member 5 is limited by the matching portion 412, the rotating member 5 also has a rotational movement while moving in the B2 direction. The second column portion 55 rotates from the first half 4122 to the second half 4123 around the protrusion 4121 through the notch portion 57, the first column portion 54 of the rotating member 5 is separated from the support portion 411 and rotates to a position where the circumferential surface of the first column portion 54 is opposite to the support portion 411 and the avoidance portion 56 is staggered from the support portion 411, and the rotating member 5 returns to the initial position, waiting for the next developing work to start and receive the driving force again to run.

[0073] It should be noted that the delay mechanism of this embodiment is arranged at the driving end of the processing box, and can also be arranged at the conductive end opposite to the driving end, or can also be arranged at both the driving end and the conductive end of the processing box.

[0074] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A process cartridge, detachably mounted on an image forming device, comprising: A drum unit rotatably supports a photosensitive drum; a developing unit rotatably supporting a developing roller, the developing unit being movable relative to the drum unit between a contact position at which the developing roller contacts the photosensitive drum and a separation position at which the developing roller separates from the photosensitive drum; A developing coupling, provided at the developing unit, for receiving a driving force of the image forming device to rotate, and driving the developing unit to move from a separation position to a contact position under the action of a torque; The invention is characterized in that it also comprises a delay mechanism for extending the time required for the developing unit to move from the separation position to the contact position.

2. The process cartridge according to claim 1, wherein: The delay mechanism includes a rotating member disposed on the developing unit and directly or indirectly receiving the driving force of the developing coupling for rotation, and a supporting portion and a matching portion disposed on the drum unit and matching with the rotating member.

3. The process cartridge according to claim 2, wherein: The rotating member includes a gear portion and a toothless portion connected and arranged along its circumference; When the gear portion is directly or indirectly engaged with the developing coupling, the rotating member is driven to rotate; When the rotating member rotates until the tooth-missing portion faces the developing coupling, the rotating member stops receiving the driving force.

4. The process cartridge according to claim 2, wherein: The rotating member comprises a first column portion arranged along its axial direction, and a relief portion recessed inwardly is provided on the surface of the first column portion.

5. The process cartridge according to claim 4, wherein: When the support portion abuts against the surface of the first column portion, the developing roller is separated from the photosensitive drum; When the rotating member rotates until the supporting portion faces the escape portion, the developing roller contacts the photosensitive drum.

6. The process cartridge according to claim 5, wherein: The supporting portion is arranged on the end cover of the drum unit, and the supporting portion is a convex column, and the convex column extends along the width direction of the processing box.

7. The process cartridge according to claim 5, wherein: The rotating member comprises a second column portion arranged along its axial direction, and a notch portion is provided on the second column portion.

8. The process cartridge according to claim 7, wherein: The rotating member is disposed outside a driving side bearing of the developing unit, and along an axial direction of the rotating member, the second column portion is farther from the driving side bearing than the first column portion.

9. The process cartridge according to claim 7, wherein: At least a portion of the second column portion is embedded in the matching portion, and a protrusion portion matching with the notch portion is provided in the matching portion.

10. The process cartridge according to claim 9, wherein: The protrusion separates the matching portion into a first half and a second half that are connected; When the second column portion moves between the first half portion and the second half portion, the notch portion rotates around the protrusion portion.

11. The process cartridge according to claim 10, wherein: When the developing unit is in the separated position, the second column portion is located in the second half; When the developing unit moves from the separated position to the contact position, the second column portion moves from the second half to the first half.

12. The process cartridge according to claim 9, wherein: The matching portion is a strip-shaped hole or a strip-shaped groove arranged on the end cover of the drum unit, the matching portion extends along the width direction of the processing box, and the protrusion is arranged on an inner wall in the extending direction of the matching portion.

13. The process cartridge according to claim 8, wherein: The diameter of the first column portion is greater than the diameter of the second column portion.

14. The process cartridge according to any one of claims 1 to 13, characterized in that: The invention also includes a first elastic member, which is respectively connected to the developing unit and the drum unit and applies a force to the developing unit to move from a contact position to a separation position.

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