BACKGROUND

[0001 ] An electrophotographic image forming apparatus supplies a toner to an electrostatic latent image formed on a photoconductor to form a visible toner image on the photoconductor, transfers the visible toner image to a recording medium, and then fixes the transferred visible toner image on the recording medium to print an image on the recording medium.

[0002] A development cartridge is an assembly of parts for forming a visible toner image, and is detachable from a main body of an image forming apparatus. The development cartridge is a consumable that is replaced at the end of its service life. If the toner contained in the development cartridge is consumed, the development cartridge is replaced with a new development cartridge. The development cartridge includes a driven coupler. When the development cartridge is mounted on the main body, the driving coupler provided in the main body is engaged with the driven coupler. The driving force of a motor provided in the main body is transmitted to the development cartridge through the driving coupler and the driven coupler.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. 1 is a schematic diagram of an example of an electrophotographic image forming apparatus.

[0004] FIG. 2 is a schematic cross-sectional view of an example of a driving coupler.

[0005] FIG. 3 is a partial perspective view showing an example of a driven coupler.

[0006] FIG. 4 is a diagram showing operations of the driven coupler and the driving coupler shown in FIGS. 2 and 3, respectively.

[0007] FIG. 5 is a partial side view of an example of a development cartridge.

[0008] FIG. 6 is a partially exploded perspective view of an example of the development cartridge shown in FIG. 5.

[0009] FIG. 7 is a perspective view of an example of a coupling structure between a driving coupler and a driven coupler.

[0010] FIG. 8 shows an operation of an example of the coupling structure shown in FIG. 7.

[0011 ] FIG. 9 is a perspective view of an example of a coupling structure between a driving coupler and a driven coupler.

[0012] FIG. 10 shows an operation of an example of the coupling structure shown in FIG. 9.

DETAILED DESCRIPTION OF EXAMPLES

[0013] An image forming apparatus includes a development cartridge. The development cartridge is attached to and detached from a main body of the image forming apparatus. The development cartridge includes a driven coupler. The main body of the image forming apparatus includes a driving coupler. When the development cartridge is mounted on the main body, the driven coupler and the driving coupler are engaged with each other. The main body includes an opening and a door that can open and close the opening. The development cartridge is attached and detached to the main body through the opening. In order to prevent the driving coupler from interfering with the development cartridge to be mounted on the main body, the driving coupler may move to a standby position where the driving coupler does not interact with the development cartridge in conjunction with an operation of opening the door. The development cartridge may be mounted on the main body, and the driving coupler may move to a driving position where the driving coupler is engaged with the driven coupler in conjunction with an operation of closing the door. An example structure in which the driving coupler can move to the standby position and the driving position in connection with opening and closing the door includes a plurality of links for connecting the door and the driving coupler, which makes the structure of the image forming apparatus more complicated and increases the cost. [0014] According to present examples, a driving coupler is mounted on the main body such that the driving coupler may pivot between the standby position and the driving position. The driven coupler of the development cartridge has a position fixed to the development cartridge. The driven coupler does not pivot or move. When the development cartridge is mounted on the main body, the driving coupler interacts with the driven coupler and pivots from the standby position to the driving position. When the development cartridge is removed from the main body, the driving coupler interacts with the driven coupler and pivots from the driving position to the standby position. According to this configuration, because a link or the like connecting the door and the driving coupler does not have to be provided, the structure of the image forming apparatus may be simplified and cost may be reduced. In addition, because a development cartridge is a consumable that is replaced if a developer contained therein, such as a toner, is consumed, according to an example arrangement in which the driven coupler pivots, a plurality of parts are used to mount the driven coupler in the development cartridge so as to be pivotable, which may increase the cost of the development cartridge.

[0015] According to present examples, because the driven coupler is fixed to the development cartridge, the cost of the development cartridge that is consumable may be reduced. In some examples, the driven coupler is partially exposed to the outside of the development cartridge. The development cartridge includes a protective rib surrounding an exposed part of the driven coupler, e.g., a driven coupling portion, and a shutter exposing the driven coupling portion in conjunction with an operation of mounting the development cartridge on the main body. With such a configuration, damage to the driven coupling portion may be prevented. The following describes examples of the image forming apparatus and the development cartridge.

[0016] FIG. 1 is a schematic diagram of an example of an electrophotographic image forming apparatus. FIG. 2 is a schematic cross-sectional view of an example of a driving coupler 400. FIG. 3 is a partial perspective view showing an example of a driven coupler 300. Referring to FIGS. 1 to 3, an example of the image forming apparatus includes a main body 100 having an opening 101 and a driving member 102, and a cartridge attachable to or detachable from the main body 100 through the opening 101 . The cartridge includes a rotating member and a driven coupler 300 that includes a driven coupling portion 310 and is connected to the rotating member.

[0017] A driving coupler 400 is connected to the driving member 102, and the driving coupler 400 can rotate. The driving coupler 400 includes a driving coupling portion 410 engaged with the driven coupling portion 310. The driving coupler 400 is connected to the driving member 102 to pivot to a standby position inclined toward the opening 101 and a driving position. In the driving position, the driving coupling portion 410 interacts with the driven coupling portion 310, is aligned with the driven coupling portion 310, and is engaged with the driven coupling portion 310 when the cartridge is mounted on the main body 100.

[0018] The main body 100 may include an exposure device 110, a transfer roller 120, and a fuser 130. The main body 100 may include a print medium transport structure that loads and transports a print medium P on which an image is to be formed. The cartridge may include a development cartridge 200. The development cartridge 200 contains a developer, for example, a toner. The development cartridge 200 may include a photosensitive drum 1 and a developing roller 4. If a charging bias voltage is applied to a charging roller 2, the surface of the photosensitive drum 1 is charged with a uniform surface electric potential.

[0019] The exposure device 110 irradiates the photosensitive drum 1 with light modulated according to image information to form an electrostatic latent image on the photosensitive drum 1 . The toner is supplied to the surface of the developing roller 4 by an agitator 7 and a supply roller 6. As the developing roller 4 rotates, the toner adhered to the surface of the developing roller 4 is regulated by a regulating member 5 to form a toner layer having a uniform thickness. When the toner layer reaches a developing region where the photosensitive drum 1 and the developing roller 4 face each other, the toner is adhered to the electrostatic latent image on the photosensitive drum 1 by a developing bias voltage applied to the developing roller 4. Thus, a visible toner image is formed on the photosensitive drum 1 .

[0020] Printing media P are picked up by a pickup roller 142 one by one from a loading table 141 , and a print medium P is transported by transport rollers 143, 144, and 145 to a transfer region where the photosensitive drum 1 and the transfer roller 120 face each other. The toner image is transferred to the print medium P by a transfer bias voltage applied to the transfer roller 120. The fuser 130 applies heat and pressure to the toner image transferred to the print medium P to fuse the toner image on the print medium P. The print medium P that has passed through the fuser 130 is discharged by a discharge roller 146 to the outside of the main body 100.

[0021 ] A waste toner remaining on the surface of the photosensitive drum 1 after transfer of the toner image to the print medium P is removed by a cleaning blade 8, and the removed waste toner may be contained in a waste toner container 9.

[0022] The development cartridge 200 is a consumable that is replaced when its service life has expired. The service life of the development cartridge 200 having expired refers to when the service life of parts (for example, the photosensitive drum 1 , the developing roller 4, etc.) included in the development cartridge 200 have expired, or when the toner contained in the development cartridge 200 is wholly consumed. The main body 100 includes an opening 101 that provides a passage through which the cartridge is mounted or removed. A door 103 opens and closes the opening 101.

[0023] The main body 100 includes the driving coupler 400 and the driving member 102. Referring to FIG. 2, the driving member 102 may be, for example, a gear. The driving member 102 rotates by the driving motor 104 provided in the main body 100. The driving coupler 400 is connected to the driving member 102 and is rotatable. The driving coupler 400 is pivotably connected to the driving member 102.

[0024] As an example, the driving coupler 400 may be connected to the driving member 102 by a universal joint structure. The driving coupler 400 may include a driving shaft 401 and a pivot pin 403 provided at one end of the driving shaft 401 . For example, a spherical portion 402 is provided at one end of the driving shaft 401 , and the pivot pin 403 may penetrate the spherical portion 402 and protrude to the outside of the spherical portion 402. The pivot pin 403 may penetrate the center of the spherical portion 402.

[0025] The driving member 102 includes a supporting portion 102-1 pivotally supporting the pivot pin 403. Both ends of the pivot pin 403 protruding from the spherical portion 402 are inserted into the supporting portion 102-1. With this configuration, the driving coupler 400 may pivot by using the pivot pin 403 as an axis. The driving coupling portion 410 is provided at the other end of the driving shaft 401 .

[0026] The driven coupler 300 is provided in the development cartridge 200. The development cartridge 200 includes one or more rotating members. The rotating members may include, for example, the photosensitive drum 1 , the developing roller 4, and the supply roller 6. The driven coupler 300 may be coupled to one end of a rotating member. As an example, referring to FIG. 3, the driven coupler 300 may be coupled to one end of the photosensitive drum 1 .

[0027] The driven coupler 300 may include a body portion 301 coupled to one end of the photosensitive drum 1 , and the driven coupling portion 310 can engage with the driving coupling portion 410. The driven coupling portion 310 may include a driven shaft 311 extending from the body portion 301 , a hemispherical convex portion 312 provided at an end of the driven shaft 311 , and a driven pin 313 provided in the hemispherical convex portion 312. The driven pin 313 may penetrate the center of the hemispherical convex portion 312 and protrude to the outside of the hemispherical convex portion 312.

[0028] The driven pin 313 can receive a rotational force from the driving coupling portion 410. Referring to FIG. 2, the driving coupling portion 410 includes a concave receiving portion 411 provided at the other end of the driving shaft 401 . The concave receiving portion 411 can receive the hemispherical convex portion 312 of the driven coupling portion 310.

[0029] A pair of driving protrusions 412 protrudes from the outer circumference of the receiving portion 411 in the axial direction, and the protrusions 412 can engage with the driven pin 313 of the driven coupling portion 310. The concave receiving portion 411 may have, for example, a concave hemispherical shape or a concave conical shape. When the development cartridge 200 is located at a mounting position, both ends of the driven pin 313 protruding from the outside of the hemispherical convex portion 312 are attached to the pair of driving protrusions 412.

[0030] FIG. 4 is a diagram showing operations of the driven coupler 300 and the driving coupler 400 shown in FIGS. 2 and 3, respectively. In FIG. 4, reference numeral 501 denotes the driving coupler 400 being located at a standby position and inclined toward the opening 101. In this state, the development cartridge 200 is inserted into the main body 100 through the opening 101.

[0031 ] As the development cartridge 200 moves in a mounting direction A1 , the hemispherical convex portion 312 comes into contact with the receiving portion 411 , as denoted by reference numeral 502. In this state, if the development cartridge 200 further moves in the mounting direction A1 , the driving coupler 400 starts to pivot in a rotational direction B1 with respect to the pivot pin 403.

[0032] When the development cartridge 200 reaches the mounting position as denoted by reference numeral 503, the driving coupler 400 reaches the driving position. The hemispherical convex portion 312 is received in the receiving portion 411. Accordingly, the driving coupling portion 410 and the driven coupling portion 310 are aligned. Both ends of the driven pin 313 are attached to the pair of driving protrusions 412. When the driving member 102 rotates in this state, the driving coupler 400 rotates. The driving protrusions 412 push the driven pin 313, and the driven coupler 300 rotates in the same direction as the driving coupler 400.

[0033] Because the driving member 102 and the driving coupler 400 are connected to each other by the universal joint structure, even though the driving shaft 401 and the driven shaft 311 are not completely aligned in a straight line, the rotation of the driving member 102 may be delivered to the driven coupler 300 through the driving coupler 400.

[0034] Accordingly, rotation of the driving member 102 may be delivered to the photosensitive drum 1 such that the photosensitive drum 1 may rotate. The photosensitive drum 1 may be connected to another rotating member, such as the charging roller 2, the developing roller 4, the supply roller 6, the agitator 7, etc. by power transmission members, for example, gears. Accordingly, the rotating members of the development cartridge 200 may rotate.

[0035] A process of removing the development cartridge 200 from the main body 100 is in the reverse order of the process of mounting the development cartridge 200 on the main body 100. In a state denoted by reference numeral 503 in FIG. 4, the development cartridge 200 moves in a removal direction A2. As the driven coupler 300 moves in the removal direction A2, the hemispherical convex portion 312 pushes the receiving portion 411 in the rotational direction B2. The driving coupler 400 starts to rotate in the direction B2 from the driving position with respect to the pivot pin 403.

[0036] If the development cartridge 200 further moves in the removal direction A2, the driving coupler 400 reaches a standby position as denoted by reference numeral 502. When the development cartridge 200 further moves in the removal direction A2, the hemispherical convex portion 312 is detached from the receiving portion 411 , and the driving coupler 400 remains in the standby position. Both ends of the driven pin 313 are detached from the pair of driving protrusions 412. The development cartridge 200 is removed from the main body 100 through the opening 101.

[0037] As described above, because the driven coupler 300 is mounted at a fixed position of the development cartridge 200, the cost of the development cartridge 200 may be reduced, and printing cost per sheet may be reduced. In addition, because the driving coupler 400 pivots between the standby position and the driving position due to interaction with the driven coupler 300, the cost of the main body 100 may be reduced as compared to the cost of an example structure in which the driving coupler 400 pivots in conjunction with opening and closing operations of the door 103.

[0038] FIG. 5 is a partial side view of an example of the development cartridge 200. FIG. 6 is a partially exploded perspective view of an example of the development cartridge shown in FIG. 5. Referring to FIGS. 5 and 6, the development cartridge 200 may include a housing 201 in which toner is contained, one or more rotating members, and the driven coupler 300 that can be rotated by receiving a rotational force from outside the development cartridge 200, The housing 201 may include a side wall 202. The rotation of the driven coupler 300 rotates the rotating members of the development cartridge.

[0039] The driven coupler 300 includes the driven coupling portion 310 that protrudes outwardly from the side wall 202 of the housing 201 and that receives the rotational force. A protective rib 210 protrudes from the side wall 202 of the housing 201 to surround the driven coupling portion 310. The protective rib 210 includes an opening 211 exposing the driven coupling portion 310. A shutter 220 is mounted on the side wall 202 and is switchable to an open position and a blocking position for opening and closing the opening 211 , respectively.

[0040] The main body 100 may include an interaction member 106 that interacts with a shutter 220 when the development cartridge 200 is mounted, where the interaction member 106 can switch the shutter 220 to the open position to open the opening 211 .

[0041 ] As an example, the housing 201 of the development cartridge 200 supports the rotation members. In the present example, the side wall 202 is coupled to the side of the housing 201 as a separate member. The driven coupling portion 310 protrudes from the side wall 202 through a through hole 203 provided in the side wall 202. The protective rib 210 protrudes from the side wall 202 and partially surrounds the driven coupling portion 310. The protective rib 210 is opened when the development cartridge 200 moves in the mounting direction A1 to form the opening 211 . The shutter 220 may rotate, for example, to the blocking position to close the opening 211 , and to the open position to open the opening 211 .

[0042] The housing 201 includes a rotation shaft 205. The rotation shaft 205 protrudes through a through hole 204 of the side wall 202. The shutter 220 is supported on the rotation shaft 205 to be rotatable. The shutter 220 may include a blocking portion 221 that blocks the opening 211 , and an interaction portion 222 that interacts with the interaction member 106 provided in the main body 100.

[0043] The shutter 220 may be biased to the blocking position. For example, the shutter 220 may be elastically biased to the blocking position by an elastic member, for example, a torsion coil spring 206. In the blocking position, the shutter 220 closes the opening 211 .

[0044] With this configuration, while the development cartridge 200 is separated from the main body 100, the shutter 220 is biased to the blocking position as shown by a solid profile of the shutter in FIG. 5. The driven coupling portion 310 is surrounded by the protective rib 210 and the blocking portion 221 of the shutter 220. Accordingly, the driven coupling portion 310 may be protected from being damaged by an external impact during a process of handling of the development cartridge 200. When the development cartridge 200 is being mounted on the main body 100, before the driven coupling portion 310 is engaged with the driving coupling portion 410 that is at the standby position, the interaction member 106 provided in the main body 100 engages with the interaction portion 222 of the shutter 220. As the development cartridge 200 moves in the mounting direction A1 , the shutter 220 is pushed by the interaction member 106, and the shutter rotates to the open position as shown by the dotted profile of the shutter 220 in FIG. 5. The length of the interaction member 106 along the mounting direction A1 may be selected such that the interaction member 106 engages with the interaction portion 222 to locate and maintain the shutter 220 at the open position until the development cartridge 200 reaches the mounting position. If the development cartridge 200 is removed from the main body 100, the interaction member 106 and the interaction portion 222 are disengaged after the driving coupler 400 reaches the standby position as shown in FIG. 4. Then, the shutter 220 returns to the blocking position by the elastic restoring force of the torsion coil spring 206, and in the blocking position the shutter 220 closes the opening 211 .

[0045] FIG. 7 is a perspective view of an example of a coupling structure between a driving coupler 400a and a driven coupler 300a. Referring to FIG. 7, the driven coupler 300a is coupled to one end of a rotating member of the development cartridge 200, for example, the photosensitive drum 1 . The driven coupler 300a may include a body portion 301 coupled to one end of the photosensitive drum 1 , and a driven coupling portion 310a engaged with a driving coupling portion 410a of the driving coupler 400a. The driven coupling portion 310a may include a plurality of driven protrusions 313a arranged in a rotational direction on the body portion 301 , and a hemispherical convex portion 312a protruding from the central portion of the body portion 301 .

[0046] The driven protrusions 313a receive a rotational force from the driving coupling portion 410a. The driving coupler 400a is different from the driving coupler 400 described above in that the driving coupler 400a includes a wheel-type driving coupling portion 410a. The driving coupling portion 410a may include a plurality of spokes 412a provided at an end of the driving shaft 401 opposite the end of the driving shaft 401 at which the spherical portion 402 is provided. The plurality of spokes 412a are arranged to engage with the plurality of driven protrusions 313a. The driving coupling portion 410a may include a receiving portion 411 a to receive, at the center portion of the plurality of spokes 412a, the hemispherical convex portion 312a. The receiving portion 411 a may have a shape such as a concave hemispherical shape or a concave conical shape.

[0047] According to the configuration of FIG. 7, because spaces between the plurality of driven protrusions 313a are small, the delay between a rotation start time of the driving coupler 400a and a rotation start time of the driven coupler 300a is small. In addition, because the plurality of driven protrusions 313a and the plurality of spokes 412a are engaged, a stable rotational force transmission can be achieved. Although not shown in the drawing, the development cartridge 200 may include the protective rib (210 in FIG. 5) surrounding the plurality of driven protrusions 313a and including the opening 211 , and the shutter (220 in FIG. 5) opening and closing the opening 211 .

[0048] FIG. 8 shows an operation of an example of the coupling structure shown in FIG. 7. In FIG. 8, reference numeral 511 denotes a state in which the driving coupler 400a is at a standby position inclined toward the opening 101. In this state, the development cartridge 200 can be inserted into the main body 100 through the opening 101. As the development cartridge 200 moves in the mounting direction A1 , as denoted by reference numeral 512, the plurality of driven protrusions 313a come into contact with the plurality of spokes 412a. In this state (512), if the development cartridge 200 further moves in the mounting direction A1 , the driving coupler 400a starts to pivot in the rotational direction B1 with respect to the pivot pin 403. As denoted by reference numeral 513, in a case where the development cartridge 200 reaches a mounting position, the driving coupler 400a reaches a driving position where the driving coupling portion 410a is aligned with the driven coupling portion 310a. The hemispherical convex portion 312a is received in the receiving portion 411 a. The plurality of driven protrusions 313a are engaged with the plurality of spokes 412a. When the driving member 102 rotates in this state (513), the rotational force is delivered to the photosensitive drum 1 through the driving coupler 400a and the driven coupler 300a.

[0049] A process of removing the development cartridge 200 from the main body 100 is in the reverse order of the process of mounting the development cartridge 200 on the main body 100. In the state denoted by reference numeral 513 in FIG. 8, the development cartridge 200 moves in the removal direction A2. As the driven coupler 300a moves in the removal direction A2, the hemispherical convex portion 312a and the plurality of driven protrusions 313a push the receiving portion 411 a and the spokes 412a in the rotational direction B2. The driving coupler 400a rotates in the rotational direction B2 from the driving position with respect to the pivot pin 403, and reaches the standby position as denoted by reference numeral 512. With further movement of the development cartridge 200 in the removal direction A2, the hemispherical convex portion 312a and the plurality of driven protrusions 313a are detached from the receiving portion 411a and the plurality of spokes 412a, respectively, and the driving coupler 400a remains at the standby position. The development cartridge 200 is then removed from the main body 100 through the opening 101.

[0050] FIG. 9 is a perspective view of an example of a coupling structure between a driving coupler 400b and a driven coupler 300b. Referring to FIG. 9, the driven coupler 300b is coupled to one end of a rotating member of the development cartridge 200, for example, the photosensitive drum 1. A rotation shaft 1a is provided at one end of the photosensitive drum 1 .

[0051 ] The driven coupler 300b may include the body portion 301 coupled to an end of the rotation shaft 1 a, and a driven coupling portion 310b to be engaged with a driving coupling portion 410b. The driven coupling portion 310b may include a plurality of spokes 313b arranged in the body portion 301 in the rotational direction, and a hemispherical convex portion 312b protruding from the central portion of the body portion 301 .

[0052] The spokes 313b can receive a rotational force from the driving coupling portion 410b. The driving coupler 400b is different from the driving coupler 400 described above in that the driving coupler 400b includes the driving coupling portion 410b. The driving coupling portion 410b includes a plurality of driving protrusions 412b provided at an end of the driving shaft 401 opposite the end of the driving shaft 401 at which the spherical portion 402 is provided. The plurality of driving protrusions 412b are arranged to engage with the plurality of spokes 313b. The driving coupler portion 410b includes a receiving portion 411 b to receive, at the center portion of the plurality of driving protrusions 412b, the hemispherical convex portion 312b. The receiving portion 411 b may have a shape such as a concave hemispherical shape or a concave conical shape. [0053] Although not shown in the drawing, the development cartridge 200 may include the protective rib (210 in FIG. 5) surrounding the driven coupling portion 310b and including the opening 211 , and the shutter (220 in FIG. 5) opening and closing the opening 211 .

[0054] FIG. 10 shows an operation of an example of the coupling structure shown in FIG. 9. In FIG. 10, reference numeral 521 denotes a state in which the driving coupler 400b is located at a standby position inclined toward the opening 101. In this state, the development cartridge 200 is inserted into the main body 100 through the opening 101.

[0055] As the development cartridge 200 moves in the mounting direction A1 , as denoted by reference numeral 522, the hemispherical convex portion 312b come into contact with the plurality of driving protrusions 412b. In this state (522), if the development cartridge 200 further moves in the mounting direction A1 , the driving coupler 400b starts to pivot in the rotational direction B1 with respect to the pivot pin 403. As denoted by reference numeral 523, when the development cartridge 200 reaches a mounting position, the driving coupler 400b reaches a driving position where the driving coupling portion 410b is aligned with the driven coupling portion 310b. The hemispherical convex portion 312b is received in the receiving portion 411 b. The plurality of spokes 313b are engaged with the plurality of driving protrusions 412b. When the driving member 102 rotates in this state (523), the rotational force is delivered to the photosensitive drum 1 through the driving coupler 400b and the driven coupler 300b.

[0056] A process of removing the development cartridge 200 from the main body 100 is in the reverse order of the process of mounting the development cartridge 200 on the main body 100. In the state denoted by reference numeral 523 in FIG. 10, the development cartridge 200 moves in the removal direction A2. As the driven coupler 300b moves in the removal direction A2, the hemispherical convex portion 312b sequentially pushes the receiving portion 411 b and the plurality of driving protrusions 412b in the rotational direction B2. The driving coupler 400a rotates in the rotational direction B2 from the driving position with respect to the pivot pin 403, and reaches the standby position as denoted by reference numeral 522. With further movement of the development cartridge 200 in the removal direction A2, the hemispherical convex portion 312b and the plurality of spokes 313b are detached from the receiving portion 411 b and the plurality of driving protrusions 412b, respectively, and the driving coupler 400b remain at the standby position. The development cartridge 200 is removed from the main body 100 through the opening 101.

[0057] It should be understood that examples described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example should typically be considered as available for other similar features or aspects in other examples. While one or more examples have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.