KR20170110028A - Developing device and image forming apparatus - Google Patents

Abstract

The developing apparatus includes a developing unit including a developer carrying member and a developing frame member configured to support the developer carrying member. The developing unit is pivotably supported about the first shaft and the second shaft. A biasing member configured to bias the first shaft is provided.

Description

[0001] DEVELOPING DEVICE AND IMAGE FORMING APPARATUS [0002]

The present invention relates to an image forming apparatus using an electrophotographic image forming system (electrophotographic process) and a developing apparatus used in an image forming apparatus.

The image forming apparatus forms an image on a recording material (recording medium) using an electrophotographic process. Examples of the image forming apparatus include a printer (a laser beam printer or a light emitting diode (LED) printer), a copying machine, a facsimile apparatus, a word processor, and a multifunction printer (multifunction printer) including these devices.

Further, the developing apparatus is an apparatus for developing an electrostatic latent image formed on an electrophotographic photosensitive drum (hereinafter referred to as " photoconductor ") as an image bearing member by using a developer. The developing apparatus includes a developing unit, a developing frame member for supporting the developing unit, and a component associated with the developing unit. An example of the developing unit includes a developing roller as a developer carrying member and a developing blade as a developer regulating member.

An image forming apparatus such as a printer using an electrophotographic process charges the photoconductor uniformly. Thereafter, the image forming apparatus selectively exposes the charged photoreceptor to form an electrostatic latent image on the photoreceptor. Thereafter, using the toner as the developer, the image forming apparatus visualizes the electrostatic latent image formed on the photoconductor as a toner image. The image forming apparatus transfers the toner image formed on the photosensitive member onto a recording material such as a recording sheet and a plastic sheet, fixes the toner image on the recording material by applying heat and pressure to the transferred toner image on the recording material, Is recorded.

Generally, such an image forming apparatus requires maintenance of various process units used in an electrophotographic process. An example of the process unit includes a charging unit, a developing unit and a cleaning unit that act on the photoreceptor. In order to facilitate the maintenance of these various process units, a method of integrating the photosensitive member, the charging unit, the developing unit and the cleaning unit into the cartridge and detachably attaching the same to the main body of the image forming apparatus has been put to practical use. According to such a cartridge method, it is possible to provide an image forming apparatus excellent in usability.

A cartridge, a drum cartridge including a photosensitive drum, a developing cartridge as a developing apparatus including the developing unit, and a toner cartridge for supplying the developer are known.

There is a developing cartridge including a developing unit for pivotably supporting the developing roller and a frame for pivotally supporting both ends of the developing unit, as described in Japanese Patent Application Laid-Open No. 2013-182036 . In this configuration, the frame is positioned with respect to the body of the image forming apparatus so that the developing unit can pivot and the developing roller can be contacted with and spaced from the photosensitive drum.

The shift of the pivot center position of the developing unit in the configuration in which the developing unit is pivoted and the developing roller as the developer carrying member is in contact with the photosensitive drum as the image carrier affects the stability of the contact of the developing roller to the photosensitive drum .

According to the present invention, there is provided a developing apparatus comprising: a developing unit including a developer carrying member and a development frame member configured to support the developer carrying member; a developing unit, at one end side in the axial direction of the developer carrying member, An end supporting member configured to pivotably support the developing unit, a second end supporting member configured to pivotally support the developing unit at the other end side in the axial direction, a first shaft provided in the developing unit, And a second shaft provided on either one of the other end support member and the other end support member so as to support the first shaft so that the development unit pivots about the first shaft and the second shaft A first hole configured to allow said first shaft to move in a direction intersecting said axial direction, Wherein the developing unit is provided on the other of the developing unit and the other end supporting member and the developing unit is configured to support the second shaft so as to pivot about the first shaft and the second shaft, A second hole configured to restrict movement in a direction intersecting the axial direction; And a biasing member configured to biasing the first shaft in a direction intersecting with the axial direction.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

FIG. 1A is a view showing a developing apparatus when a shift in alignment occurs in the developing unit according to the first embodiment, and FIG. 1B is a view showing the developing apparatus when the developing unit is located at the normal position. FIG.
2 is a schematic view of an electrophotographic image forming apparatus according to Embodiment 1. Fig.
3 is a view showing a drum cartridge according to Embodiment 1. Fig.
4 is a sectional view showing a drum cartridge according to Embodiment 1. Fig.
5 is a sectional view showing the developing apparatus according to the first embodiment;
6 is a view showing the mounting of the drum cartridge and the developing apparatus according to the first embodiment;
7 is a view showing a developing apparatus according to Embodiment 1. Fig.
8A and 8B are views showing a support hole according to Embodiment 1. Fig.
9 is a view showing a state in which the developing device according to the first embodiment is positioned with respect to the main body of the image forming apparatus.
10 is a view showing a configuration in which the other-end support member is omitted from the developing apparatus according to the first embodiment;
Fig. 11A is a view showing a developing device when an alignment shift occurs in the developing unit according to the second embodiment, and Fig. 11B is a view showing the developing device when the developing unit is in the normal position.
12 is a view showing the developing apparatus according to the second embodiment;
13 is a view showing a state in which the developing apparatus according to the second embodiment is positioned with respect to the main body of the image forming apparatus.
14A and 14B are views showing an assembly of the developing apparatus according to the second embodiment;
15A and 15B show a first hole and a second hole;
16A and 16B are views showing the configuration of the first hole.
17 shows a unit biasing member;
18A and 18B are schematic diagrams showing an alignment shift.
19 is a view showing the arrangement of a biasing member;
20 is a cross-sectional view showing a developing apparatus according to a third embodiment;
FIG. 21A is a view showing a developing apparatus when an alignment shift occurs in the developing unit according to the third embodiment, and FIG. 21B is a view showing the developing apparatus when the developing unit is in the normal position.
22A and 22B are schematic diagrams showing an alignment shift according to Embodiment 3. Fig.
23A and 23B are schematic views showing a biasing member according to the third embodiment;

(Overall Configuration of Image Forming Apparatus)

First, the entire configuration of the apparatus main assembly 100 of an electrophotographic image forming apparatus (hereinafter referred to as "image forming apparatus") will be described with reference to FIG. As shown in Fig. 2, four photosensitive drum cartridges (hereinafter referred to as " drum cartridges ") 9 and 9Y (hereinafter, referred to as " drum cartridges ") having photosensitive drums as image bearing bodies and detachable from the apparatus main body 100 are provided in the apparatus main body 100 , 9M, 9C, 9K) are mounted. Four developing apparatuses (hereinafter referred to as " developing cartridges ") 4 (4Y, 4M, 4C, and 4K) are mounted on the apparatus main assembly 100. [ The drum cartridge 9 and the developing cartridge 4 are detachably mounted to the apparatus main assembly 100 by a mounting member (not shown). Further, the drum cartridge 9 and the development cartridge 4 are installed side by side in the apparatus main assembly 100 so as to be inclined with respect to the horizontal direction.

Each drum cartridge 9 has photosensitive drums 1 (1a, 1b, 1c and 1d). Process units such as charging rollers 2 (2a, 2b, 2c and 2d) as charging members and cleaning members 6 (6a, 6b, 6c and 6d) as cleaning members are integrally formed around the photosensitive drum 1 .

Each of the developing cartridges 4 (4Y, 4M, 4C, 4K) has developing rollers 25 (25a, 25b, 25c, 25d) as developer carrying members. Process units such as the developing blades 35 (35a, 35b, 35c, and 35d) as the developer regulating members are integrally disposed.

The charging roller 2 charges the surface of the photosensitive drum 1 equally. The developing roller 25 comes into contact with the photosensitive drum 1 and develops the electrostatic latent image formed on the photosensitive drum 1 by using a developer (hereinafter referred to as " toner ") to visualize the electrostatic latent image as a toner image . The cleaning member 6 removes the toner remaining on the photosensitive drum 1 after the toner image formed on the photosensitive drum 1 is transferred to the recording medium S.

Below the drum cartridge 9 and the development cartridge 4 in the apparatus main assembly 100 are arranged a photosensitive drum 1 for selectively exposing the photosensitive drum 1 based on image information to form an electrostatic latent image on the photosensitive drum 1 A scanner unit 3 as an exposure apparatus is provided.

In the lower portion of the apparatus main body 100, a cassette 17 containing the recording medium S is mounted. A recording medium conveying unit is provided to convey the recording medium S to the upper portion of the apparatus main body 100 through the secondary transfer roller 69 and the fixing unit 74. [ That is, a feeding roller 54, a pair of conveying rollers 76, and a pair of registration rollers 55 are provided. The feeding roller 54 separates the recording mediums S in the cassette 17 one by one and feeds the recording medium S. The conveying roller pair 76 conveys the fed recording medium S. The pair of registration rollers 55 synchronize the recording medium S with the electrostatic latent image formed on the photosensitive drum 1.

Above the drum cartridge 9 and the development cartridge 4 are provided intermediate transfer units 5 as intermediary transfer means for transferring the toner images formed on the respective photosensitive drums 1, 1a, 1b, 1c and 1d Is provided. The intermediate transfer unit 5 includes a drive roller 56, a follower roller 57, primary transfer rollers 58 (58a, 58b, 58c) located at positions opposite to the photosensitive drums 1 of respective colors And 58d, and a counter roller 59 at a position opposite to the secondary transfer roller 69. [ A transfer belt 14 as an intermediate transfer member extends around such a roller. The transfer belt 14 is circulatively moved in the direction of the arrow E so as to abut against all the photosensitive drums 1. [ A voltage is applied to the primary transfer rollers 58 (58a, 58b, 58c, and 58d) and is primarily transferred from the photosensitive drum 1 onto the transfer belt 14. [ A voltage is applied to the opposing roller 59 and the secondary transfer roller 69 disposed in the transfer belt 14 so that the toner on the transfer belt 14 is transferred to the recording medium S.

In forming an image, the photosensitive drum 1 is rotated so that the scanner unit 3 selectively exposes the photosensitive drum 1, which is uniformly charged by the charging roller 2. Accordingly, an electrostatic latent image is formed on the photosensitive drum 1 and is developed by the developing roller 25. [ As a result, a toner image of each color is formed on the photosensitive drum 1. [ In synchronization with this image formation, the registration roller pair 55 transfers the recording medium S to the secondary transfer position where the opposing roller 59 and the secondary transfer roller 69 are in contact with each other via the transfer belt 14 do. Then, a transfer bias voltage is applied to the secondary transfer roller 69, so that the toner images of the respective colors on the transfer belt 14 are secondarily transferred to the recording medium S. [ Thereby, a color image is formed on the recording medium S. The recording medium S on which the color image is formed is heated and pressed by the fixing unit 74, and the toner image is fixed. Thereafter, the recording medium S is discharged to the discharge portion 75 by the discharge roller 72. [ The fixing unit 74 is provided on the upper portion of the apparatus main body 100.

A unit biasing member 80 is attached to the apparatus main assembly 100 in order to bring the developing roller 25 held in the development cartridge 4 into contact with the photosensitive drum 1, (80a, 80b, 80c, 80d) are provided.

(Drum cartridge)

Next, the drum cartridge 9 according to the first embodiment will be described with reference to Figs. 3 and 4. Fig. Fig. 3 is a view showing the configuration of the drum cartridge 9 (9Y, 9M, 9C, 9K). In the present embodiment, the drum cartridges 9Y, 9M, 9C, and 9K have the same configuration. The upstream side in the insertion direction of the drum cartridge 9 and the developing cartridge 4 is defined as the near side and the downstream side in the insertion direction of the drum cartridge 9 and the developing cartridge 4 is defined as the far side .

The photosensitive drum 1 is provided with a drum front bearing 10 and a drum rear bearing 10 on the cleaning frame member 27 of the drum cartridges 9 (9Y, 9M, 9C, 9K) (11). On one end side in the axial direction of the photosensitive drum 1, a drum coupling 16 and a flange are provided.

4 is a sectional view of the drum cartridge 9. Fig. Around the photosensitive drum 1 rotating in the direction of arrow D in Fig. 4, the charging roller 2 and the cleaning member 6 are provided as described above. The cleaning member 6 includes a rubber blade 7 and a cleaning supporting member 8. The extremity portion 7a of the rubber blade 7 is disposed in contact with the photosensitive drum 1 in the direction opposite to the rotating direction of the photosensitive drum 1. [ The residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls into the removed toner chamber 27a. In addition, a sealing sheet 21 for preventing the removed toner in the removed toner chamber 27a from leaking is brought into contact with the photosensitive drum 1. The driving force of the main body driving motor (not shown) for driving is transmitted to the drum coupling 16 of the drum cartridge 9, and the photosensitive drum 1 is driven to rotate in accordance with the image forming operation. The charging roller 2 is rotatably mounted on the drum cartridge 9 via a charging roller bearing 28. [ The charging roller 2 is pressed toward the photosensitive drum 1 by the charging roller pressing member 33 and driven to rotate on the photosensitive drum 1. [

(Developing cartridge)

Next, the developing cartridge 4 will be described with reference to Fig. Fig. 5 is a sectional view of the development cartridges 4 (4Y, 4M, 4C, and 4K) for storing toners. In this embodiment, the developing cartridge 4Y containing yellow toner, the developing cartridge 4M containing magenta toner, the developing cartridge 4C containing cyan toner, and the developing cartridge 4K containing black toner are the same . The configuration of a part of each developing cartridge 4 may be different.

The developing cartridge 4 includes a developing unit 39 including a developing roller 25 and a developing frame member 31. [ The developing frame member 31 rotatably supports the developing roller 25 which is in contact with the photosensitive drum 1 and rotates in the direction of arrow B. The developing frame member 31 also includes a toner supply roller 34 rotating in contact with the developing roller 25 and a developing blade 35 regulating the toner layer on the developing roller 25. [ The developing frame member 31 includes a developing chamber 31c in which a developing roller 25 is disposed and a toner accommodating chamber 31a provided in a lower portion of the developing chamber 31c. The development chamber 31c and the toner storage chamber 31a are divided by the partition 31d. The partition 31d is provided with an opening 31b through which the toner passes when the toner is conveyed from the toner accommodating chamber 31a to the developing chamber 31c. The developing frame member 31 is provided with a biased portion biased by unit biasing members 80 (80a, 80b, 80c, 80d) (see Fig. 2) 31e are provided.

The developing roller 25 and the toner supplying roller 34 are rotatably supported by the developing frame member 31 (See Fig. 7).

The toner stored in the toner storage chamber 31a is stirred in the toner storage chamber 31a of the developing frame member 31 in the direction of the arrow N in Fig. 5 and the toner is supplied to the developing chamber 31c through the opening 31b A toner conveying member 36 is provided for conveying the toner.

The developing cartridge 4 according to the present embodiment is provided with the toner conveying member 36 having the rotation center of the toner conveying member 36 lower in the gravity direction than the opening lower portion 31b1 on the lower side in the gravity direction of the opening 31b And the center of the developing roller 25 is positioned higher than the opening lower side portion 31b1 in the gravity direction. The toner conveying member 36 scoop up the toner from the toner accommodating chamber 31a provided below the developing chamber 31c. The toner conveying member 36 supplies the toner to the developing chamber 31c.

(Configuration in which the drum cartridge and developing cartridge are inserted into the electrophotographic image forming apparatus)

Next, a configuration for inserting the drum cartridge 9 and the developing cartridge 4 into the apparatus main assembly 100 will be described with reference to Fig. The apparatus main assembly 100 is provided with mounting openings 101 (101a, 101b, 101c, 101d) in which the respective drum cartridges 9 and the respective developing cartridges 4 are mounted. The drum cartridge 9 is attached and detached with respect to the mounting opening 101 such that the loading / ejecting direction of the drum cartridge 9 is the axial direction of the photosensitive drum 1. [ The developing cartridge 4 is detachably attached to the mounting opening 101 so that the loading / unloading direction of the developing cartridge 4 is the axial direction of the developing roller 25. [ That is, the drum cartridge 9 and the developing cartridge 4 are configured to be inserted farther from the near side. In the following description, this direction will be referred to as " insertion direction F ". 6, the drum cartridge 9 and the developing cartridge 4 are detachable from the apparatus main assembly 100 independently of each other. That is, the developing cartridge 4 is detachable from the apparatus main body 100 including the photosensitive drum 1, in which the latent image is developed by the developing roller 25. [ The developing cartridge 4 is mounted on the apparatus main assembly 100 in a state in which the drum cartridge 9 including the photosensitive drum 1 on which the latent image is developed by the developing roller 25 is mounted on the apparatus main assembly 100 It is removable.

Upper guide portions 103 (103a, 103b, 103c, 103d) of a drum cartridge, which is a third body guide portion, are provided on the upper side of the apparatus main body 100. [ On the lower side of the apparatus main body 100, a drum cartridge lower guide portion 102 (102a, 102b, 102c, 102d) as a fourth main body guide portion is provided. The drum cartridge upper guide portion 103 and the drum cartridge lower guide portion 102 extend along the insertion direction F of the drum cartridge 9, respectively.

On the upper side of the apparatus main body 100, development cartridge upper guide portions 105 (105a, 105b, 105c, 105d) which are first main body guide portions are provided. On the lower side of the apparatus main body 100, there are provided developing cartridge lower guide portions 104 (104a, 104b, 104c, 104d) which are second main body guide portions. The development cartridge upper guide portion 103 and the development cartridge lower guide portion 104 extend along the insertion direction F of the development cartridge 4, respectively.

When the drum cartridge 9 is inserted, the drum cartridge 9 is disposed on the side closer to the mounting direction of the drum cartridge lower guide portion 102 and the upper drum cartridge guide portion 103. The drum cartridge 9 is moved in the insertion direction F along the drum cartridge upper guide portion 103 and the drum cartridge lower guide portion 102 and is inserted into the apparatus main body 100. [

The developing cartridge 4 is similarly inserted into the drum cartridge 9. The development cartridge 4 is disposed on the side close to the mounting direction of the development cartridge upper guide portion 105 and the development cartridge lower guide portion 104. [ The development cartridge 4 is moved in the insertion direction F along the development cartridge upper guide portion 105 and the development cartridge lower guide portion 104 and is inserted into the apparatus main assembly 100. [

(Details of the development cartridge configuration)

Next, details of the construction of the developing cartridge 4 according to the first embodiment of the present invention will be described with reference to Figs. 1A, 1B, 7, 8A, 8B and 9.

7, an end supporting member (first end supporting member) 38 for pivotally supporting an end of the developing unit 39 on the one end side in the axial direction of the developing roller 25, Is provided. On the other hand, the other end supporting member pivotally supporting the other end side end of the developing unit 39 (the end opposite to the end portion provided with the end supporting member 38) in the axial direction of the developing roller 25 Two end support members) 37 are provided. The end support member 38 and the other end support member 37 are engaged with each other through the developing unit 39 disposed between the end supporting member 38 and the other end supporting member 37, Respectively.

The other end support member 37 is provided with a developing unit 39 in such a manner that the developing unit 39 is supported in a pivotable manner so that the developing unit 39 is positioned in the second position as a positioning hole for regulating the position of the developing unit 39 in a direction crossing the axis of the developing roller 25. [ A hole 37a is provided. The developing unit 39 is pivotably supported on the end support member 38 so that the developing unit 39 can be moved in a direction (preferably orthogonal to) the axis of the developing roller 25 A first hole 38a as a support hole for supporting the developing unit 39 is provided.

Further, the developing unit 39 is provided with a boss 13a (corresponding to the first shaft) as a support shaft which is pivotably supported by the first hole 38a. On the other end side of the developing roller 25 in the axial direction, as opposed to the boss 13a of the developing unit 39, a boss 12a (a second shaft) is provided as a positioning shaft pivotably supported by the second hole 37a. Is provided. The bosses 12a and 13a have a cylindrical shape. In this embodiment, the bosses 12a and 13a are concentric with each other and provided parallel to the axis of the developing roller 25. [

The first hole 38a and the boss 13a are engaged with each other and the second hole 37a and the boss 12a are engaged with each other as shown in Fig. The end support member 38 and the other end support member 37 are fixed to the developing unit (not shown) around the bosses 13a and 12a, which are pivotally supported by the first hole 38a and the second hole 37a, 39). The end support member 38 and the other end support member 37 are independently movable (pivotable) with respect to the developing unit 39. That is, the end support member 38 is configured to support the end portion of the developing unit 39 on one end side in the axial direction of the developing roller 25, and the developing unit 39 on the other end side in the axial direction of the developing roller 25 In the present embodiment. Conversely, the other end support member 37 is configured to support the end of the developing unit 39 on the other end side in the axial direction of the developing roller 25, and the developing unit 25 on the other end side in the axial direction of the developing roller 25 39 are not supported. In other words, the other end support member 37 is pivotable with respect to the developing unit 39 and the end support member 38. [ The end support member 38 is pivotable with respect to the developing unit 39 and the other end support member 37. In other words, when the other end support member 37 pivots with respect to the developing unit 39, the end supporting member 38 can stop its movement with respect to the developing unit 39 and the other end supporting member 37 have. The other end support member 37 can stop its movement with respect to the developing unit 39 and the end support member 38 when the end support member 38 pivots with respect to the developing unit 39. [

The second hole 37a has a circular hole shape. That is, the boss 12a is a positioning portion which is pivotally supported by the second hole 37a and whose movement in the direction intersecting the axial line of the developing roller 25 is regulated.

8A and 8B, the first hole 38a supports the boss 13a in a pivotable manner, and the boss 13a is long enough to move in the direction crossing the axis of the developing roller 25 Hole. That is, the first hole 38a has a first regulating portion 38a1 that regulates the radial direction of the boss 13a, and a second regulating portion 38b that intersects the first regulating portion 38a1 and is larger than the second regulating portion 38a1, Is an elongated hole having a portion 38a2. As described above, since the first hole 38a is an elongated hole, it is possible to absorb the influence that the axis of the development roller 25 and the center of the bosses 13a and 12a are shifted due to dimensional tolerance or the like. In the present embodiment, the first hole 38a has a long circular hole shape. However, the shape of the hole of the first hole 38a is not limited to the long circular hole. Alternatively, the hole shape of the first hole 38a may be an angular hole.

The first hole 38a and the second hole 37a will be further described with reference to Figs. 15A and 15B. Fig. 15A is a view showing a state in which the first hole 38a and the boss 13a are coupled to each other, Fig. 15B is a view showing a state in which the second hole 37a and the boss 12a are coupled to each other, Each drawing is a view seen from the axial direction of the developing roller 25. Fig. The direction in which the boss 13a is restricted from moving by the first restricting portion 38a1 of the first hole 38a in the direction intersecting (preferably orthogonal to) the axis of the developing roller 25 is the first direction V1 . (In a direction orthogonal to the axis of the developing roller 25) and orthogonal to the first direction V1 (direction toward the second restriction portion 38a2) is defined as the second direction V2. The first hole 38a, which is an elongated hole, allows the boss 13a to move in the second direction V2. On the other hand, the second hole 37a, which is a circular hole, restricts the movement of the boss 12a in the first direction V1 and the second direction V2. At least in the second direction V2, the distance D2 at which the boss 13a can move in the first hole 38a is longer than the distance the boss 12a can move in the second hole 37a. 16A and 16B, the first hole 38a will be further described. 16A and 16B are views showing the configuration of the first hole 38a according to the present embodiment. 16A and 16B show the developing cartridge 4 when viewed from the axial direction of the developing roller 25 in a state where the developing cartridge 4 is mounted on the image forming apparatus.

16A, the first hole 38a according to the present embodiment is arranged in a direction allowing the boss 13a to move (a direction in which the boss 13a can move in the first hole 38a) L1. Further, a circle having the same center as the center of the photosensitive drum 1 and passing through the center of the first hole 38a is defined as L2. A line connecting the center of the photosensitive drum 1 and the center of the first hole 38a is defined as L3. In this state, L1 crosses L2. Also, L1 is inclined with respect to L3. The direction of L1 is not limited to the direction shown in Fig. 16A. For example, as shown in Fig. 16B, L1 may be configured to be horizontal in a state where the developing cartridge 4 is mounted on the image forming apparatus.

As described above, the first hole 38a and the boss 13a are engaged with each other, and the second hole 37a and the boss 12a are engaged with each other. The first hole 38a allows the boss 13a to move in a direction intersecting the axial direction of the developing roller 25. [ The developing unit 39 is pivotably supported by the end support member 38 and is allowed to move in the direction intersecting the axial direction of the developing roller 25. [ The second hole 37a restricts the boss 12a from moving in the direction intersecting the axial direction of the developing roller 25. [ Therefore, the developing unit 39 is pivotally supported by the other end supporting member 37, and is restricted from moving in the direction intersecting the axial direction of the developing roller 25. [ The developing unit 39 pivots about the end support member 38 and the other end support member 37 about the boss 12a and the boss 13a, respectively.

9, the other end supporting member 37 is provided with the third to-be-engaged portion 37b and the fourth to-be-engaged portion 37c. The third to-be-engaged portion 37b and the fourth to-be-engaged portion 37c are engaged with the third main body engaging portion 98a provided in the apparatus main assembly 100 after the completion of the insertion of the developing cartridge 4 into the apparatus main assembly 100, And the fourth body coupling portion 98b, respectively. Thus, the other end support member 37 is positioned with respect to the apparatus main assembly 100. The other end support member 37 is provided with a third guided portion 37d which is guided by the development cartridge upper guide portion 105 and the development cartridge lower guide portion 104 when the development cartridge 4 is mounted, And a fourth guided portion 37e are provided (see Fig. 7).

The end supporting member 38 is provided with a first engaged portion 38b and a second engaged portion 38c. The first to-be-engaged portion 38b and the second to-be-engaged portion 38c are engaged with the first main body engaging portion 99a provided in the apparatus main assembly 100 after the completion of the insertion of the developing cartridge 4 into the apparatus main assembly 100, And the second body coupling portion 104e, respectively. Accordingly, the end support member 38 is positioned relative to the apparatus main assembly 100. [

In this embodiment, the second main assembly engaging portion 104e and the developing cartridge lower guide portion 104 are the same parts. The first to-be-engaged portion 38b and the second to-be-engaged portion 38c are engaged with the first guided portion guided by the development cartridge upper guide portion 105 and the development cartridge lower guiding portion 104, And functions also as a guided portion.

The second hole 37a and the first hole 38a are moved in the direction intersecting the axis of the developing roller 25 in a state in which the end supporting member 38 and the other end supporting member 37 are positioned with respect to the image forming apparatus And are overlapped with each other. That is, when viewed from the axial direction of the developing roller 25, the first hole 38a and the second hole 37a are arranged so as to overlap with each other. In this embodiment, the center of the first hole 38a coincides with the center of the second hole 37a (see Fig. 8). On the other hand, as described above, in this embodiment, the bosses 12a and 13a are concentric with each other and provided parallel to the axis of the development roller 25. [ That is, when the boss 13a is positioned at the center of the first hole 38a in the state where the end support member 38 and the other end support member 37 are positioned relative to the image forming apparatus, Is parallel to the axis of the photosensitive drum 1.

As shown in Figs. 1A and 1B, in a state in which the other end support member 37 and the end support member 38 are positioned relative to the apparatus main assembly 100, the bosses 12a, As shown in FIG. The developing unit 39 pivots about the bosses 12a and 13a and the developing roller 25 contacts the photosensitive drum 1. [ The boss 12a, the boss 13a, the second hole 37a and the first hole 38a are provided on the photosensitive drum 1 by the weight of the developing unit 39 itself, In a direction in which a moment is generated.

As described above, when the image is formed, the developing roller 25 of the development cartridge 4 contacts the photosensitive drum 1 to visualize the image. In this embodiment, a biased portion 31e (corresponding to the force receiving portion) of the developing frame member 31 is provided to the unit biasing member 80 (corresponding to the force applying portion) of the apparatus main assembly 100, (See Fig. 2), so that the developing roller 25 comes into contact with the photosensitive drum 1, as shown in Fig. That is, when the to-be-biased portion 31e is biased to the unit biasing member 80, the to-be-biased portion 31e is moved in the direction in which the developing roller 25 contacts the photosensitive drum 1, Are provided for movement.

17 shows the structure of the unit biasing member 80. Fig. 17 is a view showing the development cartridge 4 when viewed from the axial direction of the developing roller 25. Fig. On the far side of the paper, a developing unit 39 is located. On the side near the ground, the end support member 38 is located. The to-be-biased portion 31e of the developing frame member 31 is biased by the unit biasing member 80 in the developing unit biasing direction A1 (the same as the direction A). As a result, the developing unit 39 is pivoted in the direction R1, and the developing roller 25 contacts the photosensitive drum 1. When the to-be-biased portion 31e of the developing frame member 31 is biased by the unit biasing member 80 in the direction A2 opposite to the developing unit biasing direction A1, the developing unit pivots in the direction R2 , The developing roller 25 is spaced from the photosensitive drum 1.

The distance from the center of the developing roller 25 to the to-be-biased portion 31e is longer than the distance from the center of the developing roller 25 to the center of the boss 13a Respectively. In this embodiment, when the straight line Q1 connecting the center of the developing roller 25 and the center of the boss 13a and the straight line Q2 perpendicular to the straight line Q1 are drawn so as to pass through the center of the boss 13a, Is positioned in the region opposite to the developing roller 25 with respect to the straight line Q2.

When the to-be-biased portion 31e is biased in the developing unit biasing direction A, the developing roller 25 tries to contact the photosensitive drum 1. In this process, in the first hole 38a which is a long hole, the boss 13a moves in the direction away from the photosensitive drum 1 toward the second restricting portion 38a2. On the other hand, the boss 12a on the opposite side is restricted from moving in the direction intersecting the axis of the developing roller 25 by the second hole 37a, which is a circular hole. Therefore, the boss 12a can not move beyond a small gap between the boss 12a and the second hole 37a. As a result, the developing cartridge 4 is in a state in which the axis of the developing roller 25 is shifted from the axis of the photosensitive drum 1, that is, in the state in which the alignment shift occurs in the developing unit 39. [ Further, when the center of gravity position of the developing unit 39 moves from G1 to G2 as a result of consumption of the toner in the developing unit 39, the developing cartridge 4 may be in a similar state. 18A and 18B are schematic diagrams showing the above-described alignment shift. 18A shows a state in which the axis of the developing roller 25 is substantially parallel to the axis of the photosensitive drum 1. Fig. 18B shows a state in which the axis of the developing roller 25 is not parallel to the axis of the photosensitive drum 1, i.e., a state in which an alignment shift occurs. As shown in Figs. 18A and 18B, the boss 13a is allowed to move in the direction away from the photosensitive drum 1 by the first hole 38a which is an elongated hole. On the other hand, the boss 12a is restricted from moving in the direction intersecting the axis of the developing roller 25 by the second hole 37a which is a circular hole. Therefore, the developing cartridge 4 can be in a state in which the axis of the developing roller 25 is not parallel to the axis of the photosensitive drum 1 (a state in which an alignment shift has occurred). In such a state that the alignment shift has occurred, the developing roller 25 may not be able to contact the photosensitive drum 1.

On the other hand, the developing cartridge 4 according to the present embodiment includes a tension spring 40 which is an elastic member as a biasing portion or a biasing member in the end support member 38. [ In addition, the end support member 38 includes a spring fixing boss 38d, which is an elastic member supporting portion for supporting the tension spring 40. [ One end of the tension spring 40 is supported by a spring fixing boss 38d, which is an elastic member supporting portion of the end support member 38, and the other end is supported by a boss 13a.

The tension spring (biasing member) 40 biases the boss 13a in a direction (preferably orthogonal to the direction) intersecting the axis of the developing roller 25. [ In this manner, as shown in Fig. 1B, the boss 13a is biased in the opposite direction to the developing unit biasing direction A. That is, the boss 13A is moved in the direction in which the center of the boss 13a approaches the center of the photosensitive drum 1 (the direction in which the distance between the center of the boss 13a and the center of the photosensitive drum 1 is shortened) It is. In this embodiment, this direction is the direction in which the center of the boss 13a coincides with the center of the second hole 37a. As a result, the center of the boss 13a is positioned at the center of the photosensitive drum 1 so that the distance from the center of the boss 13a to the center of the photosensitive drum 1 is equal to the distance from the center of the boss 12a to the center of the photosensitive drum 1. [ (1). That is, the distance from the center of the boss 13a to the center of the photosensitive drum 1 and the distance from the center of the boss 12a to the center of the photosensitive drum 1 are smaller than the distance from the center of the boss 13a to the center of the photosensitive drum 1, Lt; / RTI > is smaller. Therefore, the axis of the developing roller 25 becomes closer to the axis parallel to the axis of the photosensitive drum 1. [ That is, the angle between the axis of the developing roller 25 and the axis of the photosensitive drum 1 is smaller than in the case where the tension spring 40, which is a biasing part, is not used. Therefore, the developing roller 25 can be brought into contact with the photosensitive drum 1 in a stable manner.

It is preferable that the distance from the center of the boss 13a to the center of the photosensitive drum 1 is equal to the distance from the center of the boss 12a to the center of the photosensitive drum 1, but this distance need not be completely the same. Further, although it is preferable that the axis of the developing roller 25 is parallel to the axis of the photosensitive drum 1, these axes need not be perfectly parallel.

19 is a view showing the arrangement of a tension spring 40 as a biasing member. 19 is a view showing the developing cartridge 4 viewed from the axial direction of the developing roller 25. As shown in Fig. On the far side of the paper, a developing unit 39 is located. And the end support member 38 is located on the near side of the paper. For example, as shown in Fig. 19, a projection 13c1 or 13c2 as a part of the developing unit 39 may be provided. A tension spring 40 may be disposed between the spring fixing boss 38d and the projection 13c1. Further, a tension spring 40 may be disposed between the spring fixing boss 38d and the projection 13c2. Also in this configuration, the boss 13a can be biased in a direction (preferably orthogonal direction) crossing the axis of the developing roller 25. [ The boss 13a can approach the center of the photosensitive drum 1 in a direction (preferably an orthogonal direction) crossing the axis of the developing roller 25. [ Therefore, the developing roller 25 can be brought into contact with the photosensitive drum 1 in a stable manner.

On the other hand, in the configuration in which the tension spring 40 directly biases the boss 13a, the tension spring 40 hardly generates a force (moment) for rotating the developing unit 39. [ Therefore, when the developing roller 25 contacts the photosensitive drum 1, it is difficult for the large load to be applied to the unit biasing member 80. [ For example, when the tension spring 40 is hooked on the projection 13c2, a force is applied in the opposite direction to the movement of the developing roller 25 in contact with the photosensitive drum 1. [ When the tension spring is engaged with the projecting portion 13c1, a force is applied in the opposite direction to the movement of separating the developing roller 25 from the photosensitive drum 1. [ Therefore, the boss 13a is directly biased, and a large load is hardly applied to the unit biasing member 80. [

It is also assumed that the developing unit 39 is pivoted in the direction R1 in Fig. 19 so that the tension spring 40 is caught on the projection 13c1 to bring the developing roller 25 into contact with the photosensitive drum 1. [ As a result, the projecting portion 13c1 also pivots in the direction R1 in Fig. On the other hand, the spring fixing boss 38d is provided on the end support member 38. [ As described above, the end support member 38 is fixed to the image forming apparatus. Therefore, when the developing unit 39 pivots in the direction R1 in Fig. 19, the distance between the projecting portion 13c1 and the spring fixing boss 38d is shortened. As a result, the force by which the tension spring 40 pulls the projection 13c1 decreases. Therefore, the force of the tension spring 40 needs to be strengthened.

On the other hand, in the configuration in which the boss 13a is directly biased, the distance between the boss 13a and the spring fixing boss 38d does not change even when the developing unit 39 pivots. Therefore, the force by which the tension spring 40 pulls the boss 13a is hardly reduced.

That is, although the tension spring 40 can bias the developing unit 39, it is preferable that the tension spring 40 biases the boss 13a.

In summary, in this embodiment, in the developing unit 39 and the end supporting member 38, the tension spring 40 is provided in the end supporting member 38. [ The tension spring 40 is a biasing member for biasing the developing unit 39 in the developing unit 39 and the end supporting member 38 in the direction intersecting the axial direction of the developing roller 25. [

In the present embodiment, the end support members 38 and the other end support members 37 are provided at the ends of the developing unit 39. [ However, the present invention is not limited to this configuration. For example, as shown in Fig. 10, the other end support member 37 may be omitted. That is to say, with respect to the end of the developing unit 39 at the other end side in the axial direction of the developing roller 25 (the end opposite to the end where the end supporting member 38 is provided), the developing unit 39 is pivotable Side support portion 137 is provided. The apparatus-side supporting portion 137 is provided fixedly on the far side of the apparatus main body 100. [ A hole 137a (positioning hole) corresponding to the second hole 37a according to the present embodiment can be provided on the apparatus-side support portion 137 so that the boss 12a becomes the supported portion (positioning shaft) have. In this case, the boss 12a is a positioning portion that is pivotably supported by the hole 137a and the movement in the direction intersecting the axial line of the developing roller 25 is restricted by the hole 137a.

In this case, the boss 12a is detachable to the hole 137a, and the development cartridge 4 is pivotally supported by the hole 137a through the boss 12a. Since the end support member 38 is independent of the apparatus side support portion 137, the end support member 38 is pivotable with respect to the development cartridge 4 independently of the apparatus side support portion 137. The function of the apparatus-side supporting portion 137 is similar to that of the other-end supporting member 37 in a state in which the developing cartridge 4 is mounted on the apparatus main body 100, and therefore is not described here.

The apparatus-side supporting portion 137 can be configured to be fixedly provided on a part of the portion obtained by extending the wall surface on the far side of the drum cartridge 9.

In the present embodiment, the second hole 37a is provided as the positioning portion of the developing unit 39 to the other end supporting member 37, and the boss 12a is provided to the developing unit 39. [ However, the present invention is not limited to this configuration. That is, a hole corresponding to the second hole 37a (positioning hole) according to the present embodiment can be provided to either the developing unit 39 or the other end supporting member 37. [ In this case, the positioning shaft corresponding to the boss 12a according to the present embodiment can be disposed on the other side of the developing unit 39 and the other end supporting member 37. [ In the configuration in which the other end supporting member 37 is omitted, a positioning shaft corresponding to the boss 12a can be provided to either the developing unit 39 or the apparatus-side supporting portion 137, A hole corresponding to the projection 37a may be provided on the other side of the developing unit 39 and the apparatus-side supporting portion 137. [

Next, the construction of the developing cartridge 4 according to the second embodiment of the present invention will be described with reference to Figs. 11A, 11B, 12 and 13. Fig. In this embodiment, components different from those of the first embodiment are specifically described, and components similar to those of the first embodiment are not specifically described here.

12, an end supporting member 48 (corresponding to the end supporting member 38 in the first embodiment) is provided at one end side of the developing unit 39 in the axial direction of the developing roller 25 . The end support member 48 is provided with a first hole 48a that engages with the boss 13a provided in the developing unit 39. [ The first hole 48a is similar to the first hole 38a in Embodiment 1, and supports the boss 13a in a pivotable manner. The end supporting member 48 is provided with a first engaged portion 48b and a second engaged portion 48c. The first to-be-engaged portion 48b and the second to-be-engaged portion 48c are formed in the same manner as in the first embodiment after the insertion of the developing cartridge 4 into the apparatus main assembly 100 is completed, 1 body coupling portion 99a and the second body coupling portion 104a (see Fig. 13).

In this embodiment, a pressing lever 41 as a pressing member is used as a biasing portion for biasing the boss 13a, and as a lever biasing member for biasing the pressing lever 41 toward the boss 13a, (140) is used.

As shown in Fig. 11A, the end support member 48 includes a pressure lever 41. Fig. A spring retaining portion 41a is formed as a biasing member locking portion at a position opposed to the lever supported portion 41b and the lever supported portion 41b as a pressure not supported portion in the pressure lever 41. [ In addition, the end support member 48 includes a lever support boss 48e as a pressing support portion and a spring fixing boss 48d as a biasing member engagement portion. The lever supporting boss 48e is provided such that the pressing lever 41 is located on the opposite side of the center of the first hole 48a with respect to the direction in which the boss 13a is moved. The lever-supported portion 41b is pivotally supported by the lever-supporting boss 48e. One end of the tension spring 140 is supported by the spring fixing portion 41a and the other end is supported by the spring fixing boss 48d. The pressing lever 41 is supported between the lever supporting portion 41b which is a position supported by the end support member 48 and the spring fixing portion 41a which is biased by the tension spring 140, 13a.

In order to reduce the influence of the alignment shift of the developing roller 25 as in the case of the tension spring 40 described in the first embodiment, the pressing lever 41 presses the boss 13a in the direction intersecting the axis of the developing roller 25 (Preferably in an orthogonal direction). The lever supported portion 41b of the pressing lever 41 is positioned at a distance from the lever supported portion 41b of the pressing lever 41 to the position where the press lever 41 biases the boss 13a, The distance from the spring fixing portion 41a is longer. Therefore, the spring pressure of the tension spring 140 for obtaining the force necessary for biasing the boss 13a can be reduced. Therefore, the developing roller 25 can be brought into contact with the photosensitive drum 1 in a stable manner.

That is, as shown in Fig. 11B, the boss 13a is biased in the direction opposite to the developing unit biasing direction A. That is, in the direction intersecting the axial direction of the developing roller 25, the center of the boss 13a approaches the center of the photosensitive drum 1 (the center of the boss 13a and the center of the photosensitive drum 1 In the direction in which the distance is shortened) in the first hole 48a. In this embodiment, this direction is the direction in which the center of the boss 13a coincides with the center of the second hole 37a. As a result, the distance from the center of the boss 13a to the center of the photosensitive drum 1 is equal to the distance from the center of the boss 12a to the center of the photosensitive drum 1, And is close to the center of the drum (1). The distance from the center of the boss 13a to the center of the photosensitive drum 1 and the distance from the center of the boss 12a to the center of the photosensitive drum 1 are smaller than the distance between the center of the boss 13a and the center of the photosensitive drum 1, Lt; / RTI > is smaller. The axis of the developing roller 25 becomes parallel to the axis of the photosensitive drum 1. That is, the angle between the axis of the developing roller 25 and the axis of the photosensitive drum 1 is smaller than in the case where the pressing lever 41 which is a biasing part is not used. Therefore, the developing roller 25 can be brought into contact with the photosensitive drum 1 in a stable manner.

It is preferable that the distance from the center of the boss 13a to the center of the photosensitive drum 1 is equal to the distance from the center of the boss 12a to the center of the photosensitive drum 1, but such distance need not be completely the same. It is also preferable that the axis of the developing roller 25 is parallel to the axis of the photosensitive drum 1, but such axis need not be perfectly parallel.

Similarly to Embodiment 1, although the pressure lever 41 can bias the developing unit 39, it is preferable that the pressure lever 41 biases the boss 13a.

In summary, in this embodiment, the pressing lever 41 and the tension spring 140 are provided in the end supporting member 48 in the developing unit 39 and the end supporting member 48. The pressing lever 41 and the tension spring 140 bias the developing unit 39 in the developing unit 39 and the end supporting member 48 in the direction crossing the axial direction of the developing roller 25 Biasing member.

14A and 14B, a method for assembling the developing cartridge 4 described in this embodiment will be described.

First, the developing frame member 31 is filled with toner, and the toner supplying roller 34 and the developing roller 25 are assembled. Therefore, the developing unit 39 is assembled (the first step).

Next, in a state in which the pressure lever 41 is previously mounted on the lever support boss 48e and the tension spring 140 is further mounted on the spring fixing portion 41a and the spring fixing boss 48d in advance, The member 48 is mounted on the developing unit 39 that has undergone the first process (second process).

In this manner, the developing cartridge 4 is assembled. When the other end supporting member 37 is used, the other end supporting member 37 can be mounted to the developing unit 39 in another process.

According to this assembling method, after the end support member 48 is assembled to the developing unit 39, there is no need to assemble the tension spring 140. [ Therefore, the ease of assembly of the developing cartridge 4 can be improved.

Next, the configuration of the developing cartridge 4 according to the third embodiment of the present invention will be described. In the present embodiment, components different from those of the first and second embodiments will be specifically described, and components similar to those of the first and second embodiments will not be described here.

In Embodiments 1 and 2, the developing unit 39 includes the boss 13a. The first holes 38a and 48a are included in the end support members 38 and 48, respectively. However, the first shaft (corresponding to the boss 13a) as the support shaft may be provided on either of the developing unit and the end supporting member. Further, the first hole, which is engaged with the first shaft as the support shaft, may be provided to the other of the developing unit and the end supporting member.

Further, as shown in another embodiment, the boss 12a may be provided on either the developing unit 39 or the other end supporting member 37. [ The second hole 37a to be engaged with the boss 12a may be provided on the other side of the developing unit 39 and the other end supporting member 37. [

The configuration of this embodiment will be described with reference to Fig. 20 is a schematic sectional view showing the configuration of the developing cartridge 4 according to the present embodiment. 20 is a sectional view of the developing cartridge 4 viewed from a direction orthogonal to the axis of the developing roller 25. As shown in Fig.

20, the boss 138a (corresponding to the boss 13a of the first and second embodiments) as the support shaft (first shaft) is supported by the end support member 138 And the end support members 38 and 48 of Fig. The developing unit 139 is also provided with a first hole 139a (corresponding to the first hole 38a in the first and second embodiments) as a supporting hole. Further, as shown in another embodiment, the boss 12a is provided on either of the developing unit 39 and the other end supporting member 37. [ The second hole 37a to be engaged with the boss 12a is provided on the other side of the developing unit 139 and the other end supporting member 37. [

Similar to other embodiments, the first hole 139a and the boss 138a are coupled to each other, and the second hole 37a and the boss 12a are coupled to each other. As will be described later, the first hole 139a is allowed to move in the direction intersecting the axial direction of the developing roller 25 with respect to the boss 138a. The developing unit 139 is pivotally supported by the end support member 138 and is allowed to move in the direction intersecting the axial direction of the developing roller 25. [ The second hole 37a restricts the boss 12a from moving in the direction intersecting the axial direction of the developing roller 25. [ Therefore, the developing unit 139 is pivotably supported by the other end supporting member 37 and is restricted from moving in the direction intersecting the axial direction of the developing roller 25. [ Thus, similar to Embodiment 1, the developing unit 139 pivots about the bosses 12a and 138a such that the line connecting the bosses 12a and 138a is the center of the pivot. Thus, the developing roller 25 can come into contact with the photosensitive drum 1 and can be separated from the photosensitive drum 1.

Figs. 21A and 21B are views showing the development cartridge 4 according to the present embodiment viewed from the axial direction of the developing roller 25. Fig.

Similarly to Embodiment 1, the end support member 138 and the other end support member 37 are pivotable independently of each other with respect to the developing unit 139. Further, in a state in which the development cartridge 4 is mounted to the image forming apparatus, the end support member 138 and the other end support member 37 are positioned relative to the image forming apparatus. Further, the photosensitive drum 1 is also positioned relative to the image forming apparatus via the drum cartridge 9. The biased portion 31e of the developing frame member 31 is biased in the developing unit biasing direction A1 by the unit biasing member 80 of the apparatus main assembly 100. [ Then, the developing unit 139 pivots in the direction of the arrow R1, and the developing roller 25 comes into contact with the photosensitive drum 1. [ Similarly to the other embodiments, when the to-be-biased portion 31e is biased in the developing unit biasing direction A2, the developing roller 25 is separated from the photosensitive drum 1.

When a straight line Q1 connecting the center of the developing roller 25 and the center of the boss 138a and a straight line Q2 perpendicular to the straight line Q1 are drawn through the center of the boss 138a similarly to Embodiment 1, The biasing portion 31e is arranged in the region opposite to the developing roller 25 with respect to the straight line Q2.

When the to-be-biased portion 31e is biased in the developing unit biasing direction A1, the developing unit 139 pivots and the developing roller 25 tries to contact the photosensitive drum 1. [ In this process, the first hole 139a, which is an elongated hole, moves in the direction away from the photosensitive drum 1, in the direction crossing the axis of the developing roller 25. [ On the other hand, since the boss 138a is provided on the end support member 138, the position of the boss 138a with respect to the photosensitive drum 1 does not change.

On the other hand, the boss 12a on the opposite side and the second hole 37a, which is a circular hole, are restricted from moving in a direction intersecting the axis of the developing roller 25. As a result, similarly to the first embodiment, the developing cartridge 4 is in a state in which the axis of the developing roller 25 is inclined with respect to the axis of the photosensitive drum 1, that is, a state in which an alignment shift occurs in the developing unit 39 . Figs. 22A and 22B are schematic views showing the above-described alignment shift, similarly to Figs. 18A and 18B in the first embodiment. 22A shows a state in which the axis of the developing roller 25 is substantially parallel to the axis of the photosensitive drum 1. Fig. 22B shows a state in which the axis of the developing roller 25 is not parallel to the axis of the photosensitive drum 1, i.e., a state in which an alignment shift occurs. As shown in Figs. 22A and 22B, the first hole 139a, which is an elongated hole, moves in a direction away from the photosensitive drum 1 while being coupled with the boss 138a. On the other hand, the movement of the boss 12a and the second hole 37a, which is a circular hole, in the direction intersecting the axis of the developing roller 25 is restricted. Therefore, the photosensitive cartridge 4 is in a state in which the axis of the developing roller 25 is not parallel to the axis of the photosensitive drum 1. The developing roller 25 may not contact the photosensitive drum 1 in the state in which the alignment shift has occurred.

Correspondingly, as shown in Fig. 23A, the developing cartridge 4 includes a tension spring 240, which is an elastic member as a biasing portion, in the developing unit 139. [ Further, the developing unit 139 includes a spring fixing boss 239d, which is an elastic member supporting portion for supporting the tension spring 240. [ One end of the tension spring 240 is supported by a spring fixing boss 239d which is an elastic member supporting portion of the developing unit 139 and the other end is supported by a boss 138a of the end supporting member 138. [

The tension spring 240 biases the boss 138a in a direction (preferably orthogonal to the direction) that intersects the axis of the developing roller 25. [ That is, as shown in Fig. 23A, the boss 138a is pressed by the tension spring 240 such that the first hole 139a moves in the direction opposite to the developing unit biasing direction A1.

In the direction intersecting the axial direction of the developing roller 25, the tension spring 240 biases the boss 138a such that the center of the first hole 139a moves in the opposite direction to the developing unit biasing direction A1 . The first hole 139a is formed in the first hole 139a in the direction in which the center of the first hole 139a approaches the center of the photosensitive drum 1 (the direction in which the distance between the center of the first hole 139a and the center of the photosensitive drum 1 is shortened) The center of the hole 139a moves. In this embodiment, this direction is the direction in which the center of the first hole 139a coincides with the center of the second hole 37a or the boss 12a. As a result, the distance from the center of the first hole 139a to the center of the photosensitive drum 1 is equal to the distance from the center of the second hole 37a or the boss 12a to the center of the photosensitive drum 1 The center of the first hole 139a comes close to the center of the photosensitive drum 1. That is, the distance from the center of the first hole 139a to the center of the photosensitive drum 1 and the distance from the center of the second hole 37a or the center of the boss 12a to the center of the photosensitive drum 1, The distance from the center of the photosensitive drum 1 to the center of the photosensitive drum 1 is smaller. Then, the axis of the developing roller 25 comes close to be parallel to the axis of the photosensitive drum 1. That is, the angle between the axis of the developing roller 25 and the axis of the photosensitive drum 1 is smaller than the case where the tension spring 240 which is the biasing part is not used. Therefore, the developing roller 25 can be brought into contact with the photosensitive drum 1 in a stable manner.

The distance from the center of the first hole 139a to the center of the photosensitive drum 1 is preferably equal to the distance from the center of the second hole 37a or the boss 12a to the center of the photosensitive drum 1, These distances do not have to be exactly the same. It is also preferable that the axis of the developing roller 25 is parallel to the axis of the photosensitive drum 1, but these axes need not be perfectly parallel.

Also, similar to embodiment 1, it is preferred that the tension spring 240 biases the end support member 138, but the tension spring 240 biases the boss 138a. In the above-described configuration, in the developing unit 139 and the end supporting member 138, the tension spring 240 is provided in the developing unit 139. [ The tension spring 240 is a biasing member for biasing the end supporting member 138 in the developing unit 39 and the end supporting member 138 in the direction intersecting the axial direction of the developing roller 25. [

23B, a pressing lever and a lever biasing member as the biasing member described in Embodiment 2 may be used instead of the tension spring 240. [

In this configuration, as the biasing part for biasing the boss 138a, a tension spring 340 for biasing the biasing lever 241 and the biasing lever 241 toward the boss 138a is used.

The developing unit 139 includes a pressing lever 241. The pressing lever 241 includes a lever-supported portion 241b as a pressed portion to be supported and a spring fixing portion 241a as a biasing member locking portion at a position facing the lever-supported portion 241b. The developing unit 139 also includes a lever support boss 139e as a pressing support portion and a spring fixing boss 139d as a biasing member portion. The lever supporting boss 139e is provided so that the pressing lever 241 is positioned opposite to the center of the boss 138a with respect to the direction in which the developing unit 139 moves by pressing the boss 138a. The lever-supported portion 241b is pivotally supported by the lever-supporting boss 139e. One end of the tension spring 340 is supported by the spring fixing portion 241a and the other end is supported by the spring fixing boss 139d. The pressing lever 241 is held between the lever supporting portion 241b at a position supported by the developing unit 139 and the spring fixing portion 241a at a position biased by the tension spring 340, And biasing the second end 138a.

The pressing lever 241 urges the boss 138a in the direction intersecting the axis of the developing roller 25 (preferably, in the direction perpendicular to the axis of the developing roller 25), in order to reduce the influence of the alignment shift of the developing roller 25, Direction).

The pressing lever 241 and the tension spring 340 are moved in the direction intersecting the axial direction of the developing roller 25 such that the center of the first hole 139a moves in the opposite direction to the developing unit biasing direction A1, Is biased. The center of the first hole 139a approaches the center of the photosensitive drum 1 (the center of the first hole 139a and the center of the photosensitive drum 1) in the direction intersecting the axial direction of the developing roller 25. [ The center of the first hole 139a is moved by the pressing lever 241 and the tension spring 340 in the direction in which the distance between the centers is shortened. In this embodiment, this direction is the direction in which the center of the first hole 139a coincides with the center of the second hole 37a or the boss 12a. As a result, the distance from the center of the first hole 139a to the center of the photosensitive drum 1 is equal to the distance from the center of the second hole 37a or the boss 12a to the center of the photosensitive drum 1 , The center of the first hole 139a comes close to the center of the photosensitive drum 1. The distance from the center of the first hole 139a to the center of the photosensitive drum 1 and the distance from the center of the second hole 37a or the boss 12a to the center of the photosensitive drum 1, The difference between the distances from the center to the center of the photosensitive drum 1 is smaller. Then, the axis of the developing roller 25 is brought close to parallel to the axis of the photosensitive drum 1. That is, the angle between the axis of the developing roller 25 and the axis of the photosensitive drum 1 is smaller than when the pressing lever 241 is not used. Therefore, the developing roller 25 can be brought into contact with the photosensitive drum 1 in a stable manner.

The distance from the center of the first hole 139a to the center of the photosensitive drum 1 is preferably equal to the distance from the center of the second hole 37a or the boss 12a to the center of the photosensitive drum 1, Distance does not have to be exactly the same. It is also preferable that the axis of the developing roller 25 is parallel to the axis of the photosensitive drum 1, but such axis need not be perfectly parallel.

Also, similarly to the second embodiment, it is preferable that the press lever 241 biases the end support member 138, but the press lever 241 biases the boss 138a. The pressing lever 241 and the tension spring 340 are provided to the developing unit 139 in the developing unit 139 and the end supporting member 138. [ The pressing lever 241 and the tension spring 340 are connected to the developing unit 39 and the end supporting member 138 in the direction crossing the axial direction of the developing roller 25, .

As described above, according to the present invention, it is possible to improve the stability of the contact of the developing roller as the developer carrying member to the photosensitive drum as the image bearing member.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (23)

As a developing apparatus,
A developing unit including a developer carrying member and a development frame member configured to support the developer carrying member;
An end supporting member configured to pivotably support the developing unit at one end side in the axial direction of the developer carrying member;
An other end supporting member configured to pivotally support the developing unit at the other end side in the axial direction;
A first shaft provided in the developing unit;
A second shaft provided on one of the developing unit and the other end supporting member;
Wherein the developing unit is configured to support the first shaft so as to pivot about the first shaft and the second shaft, and the first shaft is provided in the end supporting member in a direction crossing the axial direction A first hole configured to permit movement;
Wherein the developing unit is provided on the other of the developing unit and the other end supporting member and the developing unit is configured to support the second shaft so as to pivot about the first shaft and the second shaft, A second hole configured to restrict movement in a direction intersecting the axial direction; And
And a biasing member configured to biasing the first shaft in a direction intersecting with the axial direction. The method according to claim 1,
Wherein the biasing member biases the first shaft in a direction intersecting the axial direction so that the center of the first shaft is close to the center of the image bearing member. 3. The method according to claim 1 or 2,
Further comprising a force receiving portion provided in the developing unit, the force receiving portion being configured to bias the developer bearing member in contact with the image bearing member. The method of claim 3,
And when the force receiving portion is biased, the first shaft moves in a direction away from the center of the image bearing member. The method of claim 3,
Wherein the force receiving portion has a first straight line passing through the center of the first shaft and perpendicular to a second straight line connecting the center of the developer carrying member and the center of the first shaft, Is provided in the region of the developing device. 6. The method of claim 5,
Wherein the force receiving portion is biased by an urging force provided on the image forming apparatus. 3. The method according to claim 1 or 2,
Wherein the biasing member is an elastic member whose one end is supported by the end support member and the other end is supported by the first shaft. 3. The method according to claim 1 or 2,
The biasing member
A lever member rotatably supported by the end support member; And
And a lever biasing member configured to bias the lever member toward the first shaft. 9. The method of claim 8,
Wherein the lever member biases the first shaft between a position biased by the lever biasing member and a position supported by the end support member. 3. The method according to claim 1 or 2,
Wherein the first hole is configured to restrict a position of the first shaft in a radial direction of the first shaft, and a second restriction portion that restricts a position of the first shaft in the radial direction of the first shaft, And the second regulating portion is configured to regulate a position of the first shaft in a direction intersecting with a direction of regulating the position of the developing roller, wherein the second regulating portion is larger than the first regulating portion, . 3. The method according to claim 1 or 2,
Wherein the end support member and the other end support member are independently pivotable with respect to the developing unit. 3. The method according to claim 1 or 2,
Wherein the developing device is detachable from the apparatus main body in the axial direction. 3. The method according to claim 1 or 2,
Wherein the developing device is detachable from the image forming apparatus including the image bearing member to which the developer carrying member is in contact. As a developing apparatus,
A developing unit including a developer carrying member and a development frame member configured to support the developer carrying member;
An end supporting member configured to pivotally support the developing unit at one end side in the axial direction of the developer carrying member;
An other end supporting member configured to pivotally support the developing unit at the other end side in the axial direction;
A first shaft provided on the end support member;
A second shaft provided on one of the developing unit and the other end supporting member;
Wherein the developing unit is provided and the developing unit supports the first shaft so as to pivot about the first shaft and the second shaft and moves about the first shaft in a direction intersecting with the axial direction A first hole configured to be permitted;
Wherein the developing unit is provided on the other of the developing unit and the other end supporting member and the developing unit is configured to support the second shaft so as to pivot about the first shaft and the second shaft, A second hole configured to restrict movement in a direction intersecting the axial direction; And
And a biasing member configured to bias the first shaft in a direction intersecting with the axial direction. 15. The method of claim 14,
And the biasing member biases the first shaft in a direction crossing the axial direction so that the center of the first hole approaches the center of the image bearing member. 16. The method according to claim 14 or 15,
Further comprising a force receiving portion provided in the developing unit, the force receiving portion being configured to bias the developer bearing member in contact with the image bearing member. 17. The method of claim 16,
And when the force receiving portion is biased, the first hole moves in a direction away from the center of the image bearing member. 17. The method of claim 16,
Wherein the force receiving portion has a first straight line passing through the center of the first shaft and perpendicular to a second straight line connecting the center of the developer carrying member and the center of the first shaft, Is provided in the region of the developing device. A developing unit including a developer carrying member and a development frame member configured to support the developer carrying member;
An end supporting member configured to pivotally support the developing unit at one end side in the axial direction of the developer carrying member;
An other end supporting member configured to pivotally support the developing unit at the other end side in the axial direction;
A first shaft provided on either one of the developing unit and the end supporting member;
A second shaft provided on one of the developing unit and the other end supporting member;
Wherein the developing unit is provided on the other of the developing unit and the end supporting member and is coupled with the first shaft so that the developing unit pivots about the first shaft and the second shaft, A first hole configured to allow movement in an intersecting direction;
Wherein the developing unit is provided on the other of the developing unit and the other end supporting member and is coupled with the second shaft so that the developing unit pivots about the first shaft and the second shaft, A second hole configured to restrict movement in a direction intersecting the first hole; And
And a biasing member provided on either one of the developing unit and the end supporting member and configured to bias the other of the developing unit and the end supporting member in a direction crossing the axial direction,
Wherein the end support member and the other end support member are independently pivotable with respect to the developing unit. 20. The method of claim 19,
Wherein the biasing member biases the first shaft. 21. The method according to claim 19 or 20,
Further comprising a force receiving portion provided in the developing unit, the force receiving portion being biased such that the developer bearing member contacts the image bearing member. 22. The method of claim 21,
Wherein the force receiving portion has a first straight line passing through the center of the first shaft and perpendicular to a second straight line connecting the center of the developer carrying member and the center of the first shaft, Is provided in the region of the developing device. An image forming apparatus comprising:
A developing device according to claim 1; And
An image forming apparatus comprising an image bearing member.

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