Developing unit

Abstract

The present invention discloses a developing unit, comprising: a developing roller; a frame for supporting the developing roller; a movable part; the movable part includes a first force-bearing part and a second force-bearing part, an installation post is arranged on the frame, the movable part is installed on the installation post, and further includes a tension spring located between the movable part and the frame, one end of the tension spring is connected to the frame and the other end is connected to the movable part.

Description

Technical Field

[0001] The present invention relates to a developing cartridge having a pushing structure and a processing cartridge including the developing cartridge, and the developing cartridge or the processing cartridge is detachably mounted in an electrophotographic imaging apparatus.

[0002] Herein, an electrophotographic imaging apparatus is an apparatus that forms an image on a recording material using an electrophotographic imaging method. For example, it includes an electrophotographic copying machine, an electrophotographic printer (LED printer, laser printer, etc.), an electrophotographic facsimile machine, an electrophotographic word processor, and the like.

[0003] A developing cartridge is a unit including a developer carrier member for developing an electrostatic latent image formed on an image carrier member (such as an electrophotographic photosensitive member), and the above-mentioned members are integrally combined into a cartridge that is detachably mounted on the main assembly of an electrophotographic imaging apparatus.

[0004] A processing cartridge is a unit including an image carrier member (such as an electrophotographic photosensitive member), a developer carrier member for developing an electrostatic latent image formed on the image carrier member, and a developer accommodating portion for accommodating a developer, and the above-mentioned members are integrally combined into a cartridge that is detachably mounted on the main assembly of an electrophotographic imaging apparatus. Background Art

[0005] In a conventional imaging apparatus, a processing device that can act on an electrophotographic photosensitive drum and the electrophotographic photosensitive drum are integrated into a cartridge. The following type of processing cartridge is applied, that is, the cartridge is detachably mounted on the main assembly of an electrophotographic imaging apparatus. According to this type of processing cartridge, maintenance operations of the device are performed by the user without relying on service personnel, thereby significantly improving the operability. Then, this type of processing cartridge is widely used in electrophotographic imaging apparatuses.

[0006] Light corresponding to image information of a laser, an LED, or a lamp is projected onto an electrophotographic photosensitive drum in an electrophotographic imaging apparatus. Thereby, an electrostatic latent image is formed on the photosensitive drum. The electrostatic latent image is developed by a developing device. The developed image formed on the photosensitive drum is transferred onto a recording material. Thereby, an image is formed on the recording material.

[0007] During the imaging process of a traditional processing cartridge, the developing roller in the developing device cannot be separated from the photosensitive drum after printing is completed. This reduces the service lives of the developing roller and the photosensitive drum. Therefore, in order to increase the service lives of the developing roller and the photosensitive drum, Taiwan Patent Publication No. TW201621483A discloses a developing cartridge. The developing roller in the developing cartridge can be separated from the photosensitive drum after printing is completed. At the same time, the developing cartridge has a pushing structure. The pushing structure includes a movable part that can receive an external force and an elastic member disposed between the developing cartridge frame and the movable part. The elastic force after the elastic member is compressed and deformed causes the developing roller to contact the photosensitive drum with a certain pressure to complete the imaging operation. Summary of the Invention

[0008] The present invention further develops the structure of the above-mentioned prior art.

[0009] Therefore, the main object of the present invention is to provide a developing cartridge and a processing cartridge that can increase the service lives of the developing roller, the photosensitive drum, and the developer.

[0010] To achieve the above technical object, the present invention is realized through the following technical solutions:

[0011] A developing unit, comprising:

[0012] A developing roller;

[0013] A frame for supporting the developing roller;

[0014] A movable part;

[0015] The movable part includes a first force-bearing part and a second force-bearing part. An installation post is provided on the frame. The movable part is installed on the installation post. A tension spring is further included between the movable part and the frame. One end of the tension spring is connected to the frame and the other end is connected to the movable part.

[0016] Preferably, the first force-bearing part and the second force-bearing part are provided on the same movable part.

[0017] Preferably, the movable part is movably installed on the installation post and can rotate around the installation post.

[0018] Preferably, the developing unit can be installed in an imaging device having a photosensitive drum. When the developing unit is in the pushing position, the elastic force of the tension spring causes the developing roller to contact the photosensitive drum with a certain pressure.

[0019] After adopting the above solution, the developing unit provided by the present invention can separate the developing roller disposed in the developing unit and the photosensitive drum disposed in the imaging device from each other after printing, and uses a tension spring to provide an elastic force to force the developing roller and the photosensitive drum to be in pressure contact, greatly increasing the service life of the developing roller and the photosensitive drum while ensuring the stable contact between the developing roller and the photosensitive drum. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of a photosensitive unit matching the developing unit of the present invention;

[0022] Figure 2 It is an exploded structural diagram of the developing unit in the first embodiment of the present invention;

[0023] Figure 3 It is a schematic structural diagram of the developing unit in the first embodiment of the present invention;

[0024] Figure 4 It is a partial structural diagram of the pushing part of the developing unit in the first embodiment of the present invention;

[0025] Figure 5 It is a schematic structural diagram of a control guide rail in an imaging device applicable to the developing unit provided by the present invention;

[0026] Figure 6 It is a schematic structural diagram of a variant embodiment of the first embodiment of the present invention;

[0027] Figure 7 It is a partial structural diagram of the pushing part of the developing unit in the second embodiment of the present invention;

[0028] Figure 8 It is an exploded structural diagram of the pushing part of the developing unit in the third embodiment of the present invention;

[0029] Figure 9 It is an exploded structural diagram of the pushing part of the developing unit in the third embodiment of the present invention;

[0030] Figure 10 It is a partial structural diagram of the pushing part of the developing unit in the fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present invention will be described in detail below with reference to the accompanying drawings. When describing the embodiments of the present invention in detail, for the convenience of explanation, the drawings showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. It should be noted that the drawings all adopt very simplified forms and use non-precise proportions, only for the purpose of conveniently and clearly assisting in explaining the embodiments of the present invention.

[0032] Embodiment 1

[0033] As Figure 1 shown, the photosensitive unit 50 has a photosensitive drum 51, a charging roller 52 for charging the photosensitive drum 51, a frame 53 for supporting the photosensitive drum 51, and a handle 54 is provided on the frame 53.

[0034] As Figure 2 and Figure 3 shown, the developing unit 1 includes a frame 2 having a developer accommodating portion, a developing roller 3 supported on the frame 2, a power receiving portion 4 that receives the driving force of a driving head (not shown in the figure) in the imaging device and drives the developing roller 3 to rotate. An elastic member mounting portion 2a is provided on the frame 2, an elastic member 6 is mounted on the elastic member mounting portion 2a, and a cover 5 is used to protect the power receiving portion 4 and the elastic member 6. When both the developing unit 1 and the photosensitive unit 50 are mounted in the imaging device, the developing unit 1 can cooperate with a force applying unit in the imaging device and can move inside the imaging device.

[0035] For the convenience of description, the state position where the developing roller 3 in the developing unit 1 just contacts the photosensitive drum 51 in the photosensitive unit 50 but no pressure is generated between the two is called the contact position; the state position where the developing roller 3 is separated from the photosensitive drum 51 is called the separated position; the state position where the developing roller 3 is in pressure contact with the photosensitive drum 51 is called the pushing position. When the developing unit 1 is in the pushing position, the power receiving portion 4 meshes with the driving head in the imaging device and can receive the driving force from the imaging device. The developing unit 1 can move between the contact position, the separated position, and the pushing position. When viewed from the side of the power receiving portion 4 along the rotation axis direction of the developing roller 3, the direction in which the developing roller 3 in the developing unit 1 rotates toward the photosensitive drum 51 of the photosensitive unit 50 is called the forward direction M, and the direction in which the developing roller 3 rotates away from the photosensitive drum 51 is called the backward direction N. The moving direction of the main body track in the force applying unit in the Figure 5 imaging device in

[0036] As Figure 4As shown, the mounting portion 2a on the frame 2 includes a first elastic member limiting portion 2a1 and a second elastic member limiting portion 2a2. The elastic member 6 is specifically configured as an elastic metal sheet in this embodiment. The mounted portion 6e of the elastic member 6 is snapped into the gap formed between the above-mentioned first elastic member limiting portion 2a1 and the second elastic member limiting portion 2a2. The elastic member 6 includes a deformed portion 6a, a first force-bearing portion 6b, and a second force-bearing portion 6d. The first force-bearing portion 6b and the second force-bearing portion 6d are connected by a transition portion 6c.

[0037] As Figure 5 shown, the force application unit 60 in the imaging device includes a cam 61, a main body track 62, and a force application member 63. The imaging device drives the cam 61 to rotate in the R direction, and the cam 61 drives the main body track 62 to reciprocate in the left-right direction. The force application member 63 provided on the main body track 62 has a first force application portion 63a and a second force application portion 63b.

[0038] When the developing unit 1 is initially installed in the imaging device, it is in the separated position. When the main body track 62 moves in the L direction from left to right driven by the cam 61, the first force application portion 63a contacts the first force-bearing portion 6b on the elastic member 6 and further compresses the elastic member 6, causing the deformed portion 6a to deform. At the same time, the developing unit 1 is driven by the force application unit 60 to rotate in the forward direction M, move from the separated position to the contact position, and further move to the pressing position. Specifically, the first elastic member limiting portion 2a1 and the second elastic member limiting portion 2a2 on the frame 2 limit the mounted portion 6e of the elastic member 6, and the deformed portion 6a located between the mounted portion 6e and the first force-bearing portion 6b deforms. The elastic force generated by the deformation of the deformed portion 6a causes the developing roller 3 to contact the photosensitive drum 51 with a certain pressure. When printing is completed, the main body track 62 moves in the H direction from right to left driven by the cam 61, and the second force application portion 63b cooperates with the second force-bearing portion 6d to drive the developing unit 1 to rotate in the reverse direction N and move from the pressing position to the separated position. The elastic member 6 can be made of metal or resin materials such as silicone rubber, etc., as long as the provided elastic force can make the developing roller contact the photosensitive drum with a certain pressure.

[0039] As Figure 6As shown, in this embodiment, in order to further increase the strength at the elastic member 6, a reinforcing block 7 is disposed close to the elastic member 6. The reinforcing block 7 is movably mounted on the frame 2. Specifically, the reinforcing block 7 is rotatably mounted on the frame 2. Such an arrangement can not only increase the strength at the elastic member 6, but also simplify the structure of the elastic member 6. For example, the second force receiving portion 6d can be disposed in the reinforcing block 7. When the elastic member 6 is pressed by the first force applying portion 63a and elastically deformed, the reinforcing block 7 moves due to the deformation of the elastic member 6, and the elastic force of the elastic member 6 can still keep the developing unit 1 in the pushing position. To prevent excessive rotation of the reinforcing block 7, a blocking portion 2a3 is provided on the frame 2 to limit the rotation range of the reinforcing block 7. When the main body rail 62 moves the developing unit 1 from the pushing position to the separating position, the second force applying portion 63b cooperates with the reinforcing block 7 to move the developing unit 1 from the pushing position to the separating position. The arrangement of the reinforcing block 7 can effectively prevent the problem that the elastic member 6 fails due to excessive deformation.

[0040] In this embodiment, the elastic member 6 can also adopt the structure of a torsion spring. The torsion spring is mounted on the frame 2. One free end thereof is fixed to the frame 2, and a first force receiving portion capable of receiving the force of the first force applying portion 63 is provided on the other free end. The technical effect of this embodiment can also be achieved by using the elastic deformation of the torsion spring.

[0041] Embodiment Two

[0042] In this embodiment, for the components having the same functions and effects as those in the above embodiment, the same names as those in the above embodiment are used and the description is omitted.

[0043] The structure of this embodiment will be described in detail with reference to the drawings below.

[0044] As Figure 7As shown, in this embodiment, a magnetic body mounting portion 2b2 is provided on the frame 2, the first magnetic body 8 is mounted on the magnetic body mounting portion 2b2, the movable portion 601 is movably mounted on the frame 2. Specifically, a force bearing member mounting portion 2b1 is provided on the frame 2, and the movable portion 601 rotates around the force bearing member mounting portion 2b1. The second magnetic member 9 is mounted on the movable portion 601, and a first force bearing portion 601a and a second force bearing portion 601b are provided on the movable portion 601. The first force applying portion 63a and the second force applying portion 63b cooperate with the first force bearing portion 601a and the second force bearing portion 601b respectively to drive the movable portion 601 to rotate. The movable portion 601 can rotate between a first position and a second position. When the movable portion 601 rotates from the first position to the second position, the second magnetic body 9 moves closer to the first magnetic body 8. When the movable portion 601 rotates from the second position to the first position, the second magnetic body 9 moves away from the first magnetic body 8. The first magnetic body 8 and the second magnetic body 9 are arranged in such a way that when the developing unit is in the pushing position, that is, when the movable portion 601 is in the second position, the repulsive force between the first magnetic body 8 and the second magnetic body 9 is greater than the repulsive force between the first magnetic body 8 and the second magnetic body 9 when the movable portion 601 is in the first position. The same-polarity ends of the first magnetic body 8 and the second magnetic body 9 face each other, and the magnetic repulsive force between the same polarities of the first magnetic body 8 and the second magnetic body 9 enables the developing roller to contact the photosensitive drum with a certain pressure. When viewed from the axial direction of the developing roller, the distance between the second magnetic body 9 and the axis of the developing roller is longer than the distance between the first magnetic body 8 and the axis of the developing roller. In this way, when the second magnetic body 9 approaches the first magnetic body 8, it also approaches the developing roller, enabling the developing roller to contact the photosensitive drum with a certain pressure. In order to reduce the force applied by the first force applying portion 63a to the first force bearing portion 601a, a supported portion that can be rotated by the frame 2 is provided on the movable portion 601. When viewed from the axial direction of the developing roller, the distance between the force bearing portion and the supported portion is set to be longer than the distance between the second magnetic body and the supported portion. In this way, the torque of the first force applying portion 63a on the movable portion 601 can be reduced.

[0045] Embodiment Three

[0046] In this embodiment, components with the same functions and effects as those in the above embodiment are given the same names as in the above embodiment and are not described herein.

[0047] The structure of this embodiment will be described in detail below with reference to the drawings.

[0048] As Figure 8 and Figure 9As shown, in this embodiment, the first force-bearing portion 602a is provided on the movable portion 602, and the second force-bearing portion 603a is provided on the separating portion 603. The movable portion 602 and the separating portion 603 are separately provided. The frame 2 is provided with a mounting post 2c1, and the movable portion 602 and the separating portion 603 are coaxially mounted on the mounting post 2c1. The movable portion 602 and the separating portion 603 are configured to be rotatable freely with respect to each other. The frame 2 is further provided with a first elastic member connecting portion 2c2, and the movable portion 602 is provided with a second elastic member connecting portion 602b. One end of the elastic member 10 is connected to the first elastic member connecting portion 2c2 and the other end is connected to the second elastic member connecting portion 602b. The movable portion 602 can rotate under the elastic force of the elastic member 10 and is restricted by the limiting portion 2c3 provided on the frame 2 and stops at the limiting portion 2c3. Since the movable portion 602 and the separating portion 603 are coaxially mounted, the movable portion 602 is arranged closer to the inner side of the frame 2 than the separating portion 603, which can prevent the elastic member 10 connecting the movable portion 602 and the frame 2 from pressing on the separating portion 603 and causing excessive rotational resistance of the separating portion 603. On the side of the cover 501 facing the frame 2, a first clamping position 501a and a second clamping position 501b are provided. The first clamping position 501a and the second clamping position 501b are used to limit the rotation range of the separating portion 603. The first clamping position 501a is provided to prevent the separating portion 603 from rotating excessively towards the power receiving portion 4 and failing to engage with the second force applying portion 63b. The second clamping position 501b is provided such that when the second force applying portion 63b pulls the separating portion 603 to rotate, the separating portion 603 drives the developing unit to rotate by being blocked by the second clamping position 501b. When the developing unit is in the pushing position, the first force applying portion 63a pushes the movable portion 602 to rotate against the elastic force of the elastic member 10. The developing unit makes the developing roller contact the photosensitive drum with a certain pressure under the elastic force of the elastic member 10. When printing is completed, the second force applying portion 63b pulls the second force-bearing portion 603a and causes the separating portion 603 to rotate and finally drives the developing unit to be in the separating position where the developing roller is separated from the photosensitive drum. During the process of separating the developing roller from the photosensitive drum, the second force applying portion 63b never contacts the movable portion 60. Looking from the direction of the rotation axis of the developing roller 3, at least a part of the separating portion 603 and the movable portion 602 overlap to arrange the separating portion 603 and the movable portion 602 more compactly. To prevent the separating portion 603 and the movable portion 602 from detaching from the mounting post 2c1, looking from the direction of the rotation axis of the developing roller 3, the cover 501 covers at least a part of the movable portion 602 or the separating portion 603.

[0049] In this embodiment, the elastic member 10 is preferably a tension spring. Optionally, other structures such as a compression spring or a torsion spring can also be used. Through appropriate structural design, the elastic force of elastic members such as tension springs, compression springs, and torsion springs can be utilized to make the developing roller contact the photosensitive drum with a certain pressure to complete the imaging action well. As a preferred solution, the movable part 602 and the separating part 603 are coaxially mounted on the mounting post 2c1, which can make the structure more compact and reduce the volume of the developing unit. However, mounting the movable part 602 and the separating part 603 on different mounting posts of the frame 2 can also achieve the technical effects of this embodiment. The separating part 603 is arranged in a freely rotatable manner. As a preferred embodiment, the separating part 603 and the second force applying part 63b can cooperate more flexibly and are not easily disengaged. Since the separating part 603 does not need to provide the pressure for the developing roller to contact the photosensitive drum, the separating part 603 can also be set to be immovable. Specifically, the separating part 603 is restricted by the first clamping position 501a and the second clamping position 501b and cannot move, or the separating part 603 is integrally formed with the frame 2 to fix the separating part 603 on the frame, which can also achieve the technical effect of separating the developing roller from the photosensitive drum.

[0050] As Figure 10 As described above, as a variant embodiment of this embodiment, the first force bearing part 604a and the second force bearing part 604b are arranged on the same movable part 604. The movable part 604 is mounted on the mounting post 2d on the frame 2 and can rotate. One end of the tension spring 11 is connected to the frame 2 and the other end is connected to the movable part 604. When the developing unit is in the pushing position, the elastic force of the tension spring 11 is used to make the developing roller contact the photosensitive drum with a certain pressure. The volume of the developing unit can be further reduced.

[0051] In the above specific embodiments of the present invention, the movable parts preferably move in the rotational direction. However, those skilled in the art should understand that the movable part does not only rely on rotational movement to deform the elastic member to achieve the technical effect of pushing the developing roller to contact the photosensitive drum with a certain pressure. The movable part can also deform the elastic member by sliding to achieve the technical effect of pushing the developing roller to contact the photosensitive drum with a certain pressure. In the above embodiments, those of ordinary skill in the art should understand that the frame should include a cover, and components such as the movable part, the elastic member, and the separating part can be mounted on any part of the frame including the cover.

[0052] In this embodiment, the developing unit and the photosensitive unit are preferably separately arranged. Optionally, the developing unit and the photosensitive unit can also be made into an integrated processing cartridge form. Rotating the developing unit in the processing cartridge around the photosensitive unit can achieve the technical effects of the embodiments in the present invention.

[0053] Although the present invention has been described with reference to specific embodiments, various modifications can be made by those skilled in the art without departing from the scope of the present invention.

[0054] The developing unit provided by the present invention further develops the prior art, has a simple structure and low cost, enables the developing roller in the developing unit and the photosensitive drum of the photosensitive unit to be separated from each other after printing is completed, greatly increases the service life of the developing roller and the photosensitive drum, and immediately separating the developing roller and the photosensitive drum after printing can also prevent the developer from deteriorating due to being squeezed by the developing roller and the photosensitive drum for a long time, and further reduces the consumption of the developer.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A developing unit that can be installed in an imaging device having a photosensitive drum. The imaging device includes a first force application part and a second force application part. The developing unit has a pressing position in contact with the photosensitive drum and a separating position separated from the photosensitive drum. The developing unit comprises: a developing roller; a frame for supporting the developing roller; a movable part; characterized in that the movable part includes a first force receiving part, an installation post is provided on the frame, the movable part is installed on the installation post, the developing unit further includes a tension spring located between the movable part and the frame, one end of the tension spring is connected to the frame and the other end is connected to the movable part. In the front-rear direction intersecting with the axial direction of the developing roller, the tension spring, the movable part and the developing roller are arranged in sequence; the developing unit further includes a separating part, the separating part is coaxially installed on the installation post with the movable part, and the separating part includes a second force receiving part; the movable part and the separating part are separately provided, and the movable part is closer to the inner side of the frame than the separating part; the first force application part can push the movable part to rotate to the pressing position against the elastic force of the tension spring; the second force application part can pull the second force receiving part to drive the separating part to rotate and drive the developing unit to move to the separating position, and the second force application part does not contact the movable part.

2. The developing unit according to claim 1, characterized in that the movable part is movably installed on the installation post and can rotate around the installation post.

3. The developing unit according to claim 1, characterized in that the developing unit can be installed in an imaging device having a photosensitive drum. When the developing unit is in the pressing position, the elastic force of the tension spring causes the developing roller to contact the photosensitive drum with a certain pressure.

Images