WO2022025962A1

WO2022025962A1 - Structure to lock toner refill cartridge

Info

Publication number: WO2022025962A1
Application number: PCT/US2020/065083
Authority: WO
Inventors: Yongkwan Cho; Shinhyup Kang; Youngjo KWON; Seongho Jeong
Original assignee: Hewlett-Packard Development Company, L.P.
Priority date: 2020-07-27
Filing date: 2020-12-15
Publication date: 2022-02-03
Also published as: KR20220013674A

Abstract

An image forming apparatus includes a main body, a developing cartridge, and a locking member. The developing cartridge includes a toner container to contain a toner, a mounting portion to/from which a toner refill cartridge is attachable/detachable, a toner inlet portion to connect the mounting portion to the toner container, and an inlet shutter switchable between a blocking position to block the toner inlet portion and an inlet position to open the toner inlet portion, the inlet shutter to supply the toner contained in the toner container to an electrostatic latent image formed on a photosensitive drum. The locking member is installed on the mounting portion and is switchable between a locking position to lock the toner refill cartridge to the mounting portion and an unlocking position to allow attachment and detachment of the toner refill cartridge in conjunction with the inlet shutter.

Description

STRUCTURE TO LOCK TONER REFILL CARTRIDGE

BACKGROUND

[0001] Image forming apparatuses using an electrophotographic method supply toner to an electrostatic latent image formed on a photoreceptor to form a visible toner image on the photoreceptor, transfer the visible toner image to a print medium directly or via an intermediate transfer medium, and then fix the transferred visible toner image on the print medium.

[0002] A developing cartridge contains toner, and supplies the toner to an electrostatic latent image formed on a photoreceptor to form a visible toner image. When the toner contained in the developing cartridge is entirely consumed, the developing cartridge may be removed from the main body of an image forming apparatus, and a new developing cartridge may be mounted in the main body. The developing cartridge may be refilled with new toner by mounting a toner refill kit (a toner refill cartridge) in a toner refilling portion.

BRIEF DESCRIPTION OF THE DRAWINGS

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

[0004] FIG. 2 is a schematic view of the configuration of an example of the electrophotographic image forming apparatus shown in FIG. 1;

[0005] FIG. 3 is a perspective view of an example of a toner refilling portion and a toner refill cartridge;

[0008] FIG. 4 is an exploded perspective view of an example of the toner refilling portion;

[0007] FIG. 5 is a plan view showing an example of an inlet shutter located in an inlet position;

[0008] FIG. 6 is a plan view showing an example of an inlet shutter located in a blocking position;

[0009] FIG. 7 is a plan view of an example of an inlet shutter;

[0010] FIG. 8 is a perspective view showing an example of a locking member located in an unlocking position; and

[0011] FIG. 9 is a perspective view showing an example of a locking member located in a locking position.

DETAILED DESCRIPTION

[0012] An electrophotographic image forming apparatus includes a developing cartridge in which toner is contained. The developing cartridge supplies the toner to an electrostatic latent image formed on a photoreceptor to form a visible toner image. When the toner contained in the developing cartridge is consumed, a toner refill cartridge may be mounted in the developing cartridge and new toner may be refilled in the developing cartridge. If the toner refill cartridge is removed from the developing cartridge or the toner refill cartridge is not held in a mounting position after mounting the toner refill cartridge in the developing cartridge and before completing the toner refilling, the toner may leak.

[0013] In the developing cartridge and image forming apparatus of the present example, the toner refill cartridge is locked/unlocked to a mounting portion of the developing cartridge in conjunction with an opening and closing operation of an inlet shutter provided in the developing cartridge. The inlet shutter may be switched between an inlet position to allow toner filling and a blocking position to block toner inflow. A locking member is located in an unlocking position that allows the toner refill cartridge to be mounted/removed to/from the mounting portion when the inlet shutter is located in the blocking position. The locking member is switched to a locking position to lock the toner refill cartridge to the mounting portion if the inlet shutter is out of the blocking position. Accordingly, it is possible to prevent toner leakage due to the arbitrary removal of the toner refill cartridge and the sway, or unstable posture of the toner refill cartridge during a toner refilling process. A conjunction structure between the locking member and the inlet shutter may allow a user to recognize whether the inlet shutter has reached the inlet position. For example, a structure in which a weak interference impact is applied to the locking member by the inlet shutter when the inlet shutter reaches the inlet position may be employed. When the user holds the toner refill cartridge, the user may feel the weak interference impact such that the user may recognize that the inlet shutter has reached the inlet position. Hereinafter, examples of a developing cartridge and an image forming apparatus will be described with reference to the drawings.

[0014] FIG. 1 is a schematic perspective view of an example of an electrophotographic image forming apparatus. FIG. 2 is a schematic view of the configuration of an example of the electrophotographic image forming apparatus shown in FIG. 1. FIG. 3 is a perspective view of an example of a toner refilling portion 10 and a toner refill cartridge 9. FIG. 4 is an exploded perspective view of an example of the toner refilling portion 10.

[0015] Referring to FIGS. 1 to 4, the image forming apparatus includes a main body 1 and a developing cartridge 2 that is detachably attached to the main body 1. For example, after opening a door (not shown) and partially opening the main body 1, the developing cartridge 2 may be mounted/removed in/from the main body 1.

[0018] The developing cartridge 2 supplies toner contained in a toner container 230 to an electrostatic latent image formed on a photosensitive drum 21 (a photoreceptor) to develop a visible toner image. The developing cartridge 2 includes the toner container 230 in which the toner is contained, a mounting portion 11 to/from which the toner refill cartridge 9 is attachable/detachable, a toner inlet portion 12 that connects the mounting portion 11 to the toner container 230, an inlet shutter 13 that is switchabie between a blocking position to block the toner inlet portion 12 and an inlet position to open the toner inlet portion 12, and a locking member 14 installed on the mounting portion 11 such that the locking member 14 may be switched between a locking position to lock the toner refill cartridge 9 and an unlocking position to allow attachment and detachment of the toner refill cartridge 9 in conjunction with the inlet shutter 13.

[0017] Referring again to FIGS. 1 to 4, a charging bias is applied to a charging roller 23, and the photosensitive drum 21 is charged with a uniform potential. An optical scanner 4 scans light modulated in correspondence with image information to the photosensitive drum 21 to form an electrostatic latent image on the surface of the photosensitive drum 21. A supply roller 24 adheres the toner to the surface of a developing roller 22. A regulating member 25 forms a toner layer having a uniform thickness on the surface of the developing roller 22. A developing bias voltage is applied to the developing roller 22. As the developing roller 22 rotates, the toner conveyed to a developing nip is moved and adhered to the electrostatic latent image formed on the surface of the photosensitive drum 21 by the developing bias voltage, and the visible toner image is formed on the surface of the photosensitive drum 21 . A print medium P withdrawn from a medium supplier 7 by the pickup roller 71 is fed by the feed roller 72 to the transfer nip where a transfer roller 5 and the photosensitive drum 21 face each other. When a transfer bias voltage is applied to the transfer roller 5, the toner image is transferred to the print medium P by an electrostatic attraction. Printing is completed as the toner image transferred to the print medium P is fixed to the print medium P by receiving heat and pressure from a fuser 6. The print medium P is discharged by a discharge roller 73. The toner remaining on the surface of the photosensitive drum 21 without being transferred to the print medium P is removed by a cleaning member 28.

[0018] The developing cartridge 2 may include a developing portion 210 in which the photosensitive drum 21 and the developing roller 22 are installed, a waste toner container 220 in which a waste toner removed from the photosensitive drum 21 is contained, and a toner container 230 connected to the developing portion 210 and in which the toner is contained. In order to refill the toner in the toner container 230, the developing cartridge 2 may include the toner refilling portion 10 connected to the toner container 230. The toner refilling portion 10 provides an interface between the toner refill cartridge 9 and the developing cartridge 2. The developing cartridge 2 is an integrated developing cartridge including the developing portion 210, the waste toner container 220, the toner container 230, and the toner refilling portion 10.

[0019] One or more conveying members 211 that convey the toner toward the developing roller 22 may be installed in the developing portion 210. The conveying member 211 may also stir and charge the toner to a predetermined potential. The waste toner container 220 may be spaced upward from the developing portion 210 to form a passage 250 of exposure light L that is irradiated from the optical scanner 4 to the photosensitive drum 21 therebetween. The waste toner removed from the photosensitive drum 21 by the cleaning member 26 is contained in the waste toner container 220. The waste toner is transferred to the inside of the waste toner container 220 by one or more waste toner transfer members 221 , 222, and 223. The toner container 230 contains the toner and is connected to the developing portion 210 by a toner supply portion 234 as shown by a dashed line in FIG. 2. The toner supply portion 234 is located outside the effective width of the exposure light L so as not to interfere with the exposure light L scanned in the main scanning direction by the optical scanner 4. One or more toner supply members 231 , 232, and 233 for supplying the toner to the developing portion 210 through the toner supply portion 234 may be installed in the toner container 230. The toner supply member 233 may convey the toner in the main scanning direction to transfer the toner to the toner supply portion 234.

[0020] When the toner contained in the toner container 230 is consumed, new toner may be refilled in the toner container 230 by using the toner refill cartridge 9. The image forming apparatus of the present example has a structure in which the toner refill cartridge 9 is inserted from the outside of the main body 1 to the inside and mounted on the toner refilling portion 10 and the toner refill cartridge 9 is removed after the toner is refilled in the toner container 230. Referring to FIG. 1, the toner refill cartridge 9 may be a syringe type toner refill cartridge including a body 91 in which toner is contained and a plunger 92 that is movably coupled to the body 91 in a longitudinal direction B to push the toner to the outside of the body 91. A communicating portion 8 that allows the toner refill cartridge 9 to access the toner refilling portion 10 from the outside of the main body 1 is provided in the main body 1. The toner refill cartridge 9 is removed from the communicating portion 8 after toner refilling. According to the above configuration, because the toner may be refilled in the toner container 230 through the toner refilling portion 10, the replacement period of the developing cartridge 2 may extend until the service life of the photosensitive drum 21 expires, and thus, the printing cost per sheet may be reduced. The toner may be refilled while the developing cartridge 2 is mounted on the main body 1 , and thus, user convenience may be improved.

[0021] Referring to FIGS. 3 and 4, the toner refilling portion 10 may include a mounting portion 11 in which the toner refill cartridge 9 is mounted, the toner inlet portion 12 that connects the mounting portion 11 to the toner container 230, and the inlet shutter 13 that is switchable between a blocking position to block the toner inlet portion 12 and an inlet position to open the toner inlet portion 12. The locking member 14 that selectively locks the toner refill cartridge 9 in conjunction with the inlet shutter 13 is installed in the mounting portion 11.

[0022] The toner refill cartridge 9 is mounted on the mounting portion 11. The toner inlet portion 12 connects the mounting portion 11 to the toner container 230 to receive the toner from the toner refill cartridge 9 mounted on the mounting portion 11 and to transfer the toner to the toner container 230. For example, the mounting portion 11 may include an outer body 111 and an inner body 112 which is located inside the outer body 111 and receives a front end 911 of the toner refill cartridge 9. The outer body 111 is supported by the toner inlet portion 12, and the inner body 112 is supported by the outer body 111. The inner body 112 may have a cylindrical shape in which the front end 911 of the toner refill cartridge 9 is received. An insertion hole 111a is formed in the outer body 111 such that the toner refill cartridge 9 may be inserted into the inner body 112. [0023] The inlet shutter 13 may be installed in the toner inlet portion 12 such that the inlet shutter 13 may be switched to the blocking position to block the toner inlet portion 12 and the inlet position to open the toner inlet portion 12. For example, the inlet shutter 13 may be installed in the toner inlet portion 12 so as to rotate to the blocking position and the inlet position. A first support portion 121 that supports the inlet shutter 13 to rotate is provided in the toner inlet portion 12. The first support portion 121 may be implemented, for example, by a cylindrical rib protruding from the toner inlet portion 12 toward the mounting portion 11. Although not shown in the drawings, a second support portion having a shape complementary to the first support portion 121 may be provided in the inlet shutter 13. For example, the second support portion may be implemented by a circular groove into which the cylindrical rib forming the first support portion 121 is inserted. The inlet shutter 13 may include an opening 131. A toner inlet port 122 communicating with the toner container 230 may be provided in the toner inlet portion 12.

[0024] FIG. 5 is a plan view showing an example of the inlet shutter 13 located in an inlet position. FIG. 8 is a plan view showing an example of the inlet shutter 13 located in a blocking position. The inlet shutter 13 may rotate to an inlet position at which the opening 131 is aligned with the toner inlet 122 such that the toner inlet 122 is opened as shown in FIG. 5, and to a blocking position at which the opening 131 is misaligned with the toner inlet 122 such that the toner inlet 122 is blocked as shown in FIG. 6. For example, the rotational phase difference between the inlet position and the blocking position may be 180 degrees.

[0025] The inlet shutter 13 may be rotated by a driving motor 101. The driving motor 101 may be provided in the main body 1. A gear portion 132 connected to the driving motor 101 is provided in the inlet shutter 13. For example, a gear 123 may be provided in the toner inlet portion 12, and the gear portion 132 may be engaged with the gear 123. When the developing cartridge 2 is mounted on the main body 1, the driving motor 101 may be connected to the gear 123. A dutch (not shown) that selectively transfers power may be between the driving motor 101 and the gear 123.

[0028] A toner outlet 913 through which toner is discharged from the body 91 is provided in the front end 911 of the toner refill cartridge 9. When the plunger 92 is pressed in the longitudinal direction B while the toner refill cartridge 9 is mounted in the toner refilling portion 10, the toner contained in the body 91 may be discharged to the toner refilling portion 10 through the toner outlet 913 and supplied to the toner container 230 of the developing cartridge 2. The toner refill cartridge 9 may include a discharge shutter 93 that is switchabie to a discharge position to open the toner outlet 913 and a closing position to close the toner outlet 913. The discharge shutter 93 is installed in the front end 911 of the body 91. For example, the discharge shutter 93 may be installed in the front end 911 of the body 91 such that the discharge shutter 93 may rotate to the discharge position and the dosing position. An opening 931 is provided in the discharge shutter 93. The toner outlet 913 and the opening 931 are aligned with each other in the discharge position, and the toner outlet 913 and the opening 931 are misaligned from each other in the closing position.

[0027] The discharge shutter 93 may be connected to the inlet shutter 13. The discharge shutter 93 may be switched to the closing position and the discharge position as the inlet shutter 13 is switched to the blocking position and the inlet position. For example, a first connecting portion 133 and a second connecting portion 932 are provided in the inlet shutter 13 and the discharge shutter 93, respectively. When the toner refill cartridge 9 is mounted on the toner refilling portion 10, the first connecting portion 133 and the second connecting portion 932 are connected to each other. The first connecting portion 133 and the second connecting portion 932 are connected to each other such that the discharge shutter 93 may rotate together with the inlet shutter 13. For example, the first connecting portion 133 may include a pair of protrusions, and the second connecting portion 932 may include a pair of grooves into which the pair of protrusions are inserted. According to the above configuration, when the toner refill cartridge 9 is mounted on the mounting portion 11 through the communicating portion 8 of the main body 1 , the discharge shutter 93 may be connected to the inlet shutter 13. The opening 931 of the discharge shutter 93 located in the closing position and the opening 131 of the inlet shutter 13 located in the blocking position are aligned with each other. When the inlet shutter 13 rotates to reach the inlet position, the discharge shutter 93 reaches the opening position. The toner outlet 913, the opening 931 of the discharge shutter 93, the opening 131 of the inlet shutter 13, and the toner inlet 122 are aligned with each other such that the toner contained in the toner refill cartridge 9 may be refilled into the toner container 230 through the toner inlet portion 12.

[0028] The locking member 14 may be switched between a locking position to lock the toner refill cartridge 9 to the mounting portion 11 and an unlocking position that allows the toner refill cartridge 9 to be mounted/removed on/from the mounting portion 11 in conjunction with the inlet shutter 13, When the inlet shutter 13 is located in the blocking position, the locking member 14 may be located in the unlocking position. When the inlet shutter 13 is out of the blocking position, the locking member 14 may be switched to the locking position. The inlet shutter 13 may rotate to the blocking position and the inlet position, and the locking member 14 may interfere with the inlet shutter 13 and pivot to the locking position and the unlocking position.

[0029] When the toner refill cartridge 9 is separated from the mounting portion 11 while the inlet shutter 13 and the discharge shutter 93 rotate by the driving motor 101 , toner may leak, and the inlet shutter 13 and the discharge shutter 93 may be damaged. According to the present example, when the toner refill cartridge 9 is mounted on the mounting portion 11 and the inlet shutter 13 starts to rotate from the blocking position to the inlet position, the toner refill cartridge 9 is immediately locked by the locking member 14. Accordingly, leakage of toner and damage to the inlet shutter 13 and the discharge shutter 93 due to arbitrary removal of the toner refill cartridge 9 may be prevented.

[0030] Referring to FIGS. 3 and 4, the locking member 14 may be supported by the mounting portion 11 , for example, the inner body 112, so as to be pivotable to the locking position and the unlocking position. As an example, the locking member 14 may include a pivot shaft 141 , a locking portion 142 extending from the pivot shaft 141 and is caught by a locking hook 912 of the toner refill cartridge 9 to lock the toner refill cartridge 9 to the mounting portion 11 , and an interfering portion 143 extending from the pivot shaft 141 in a direction opposite to the locking portion 142. The pivot shaft 141 is supported by a shaft support portion 112a provided on the inner body 112. The pivot shaft 141 may be orthogonal to the rotation axis of the inlet shutter 13, An opened groove 112b is provided in the inner body 112 such that the locking portion 142 may access the locking hook 912 of the toner refill cartridge 9.

[0031] FIG. 7 is a plan view of an example of the inlet shutter 13. FIG. 8 is a perspective view showing the locking member 14 located in an unlocking position. FIG. 9 is a perspective view showing the locking member 14 located In a locking position.

[0032] Referring to FIGS. 7 to 9, a switching cam that switches the locking member 14 between the locking position and the unlocking position is provided in the inlet shutter 13. The switching cam interferes with the interfering portion 143 of the locking member 14. The switching cam may include a first cam 134-1 that interferes with the interfering portion 143 such that the locking member 14 is located in the unlocking position when the inlet shutter 13 is located in the blocking position and a second cam 134-2 that interferes with the interfering portion 143 to pivot the locking member 14 to the locking position when the inlet shutter 13 is out of the blocking position. The second cam 134-2 may be implemented by a cylindrical rib. The first cam 134-1 may be located outside the second cam 134-2 and implemented by a protrusion rib protruding inward toward the second cam 134-2. A part of the second cam 134-2 facing the first cam 134-1 may be immersed inward such that the interfering portion 143 may be received therein when the locking member 14 pivots to the unlocking position.

[0033] When the inlet shutter 13 is located in the blocking position, the first cam 134-1 faces the interfering portion 143 of the locking member 14. The first cam 134-1 pushes the interfering portion 143 to pivot the locking member 14 to the unlocking position as shown in FIG. 8. In the unlocking position, the locking portion 142 is spaced apart from the inner body 112. In this state, the toner refill cartridge 9 may be mounted on the mounting portion 11.

[0034] Whether the toner refill cartridge 9 is mounted on the mounting portion 11 may be determined in various ways. As an example, the toner refill cartridge 9 and the mounting portion 11 may have an electrical connection structure. Referring to FIG. 3, a first electrical contact portion 94 may be provided on the front end 911 of the toner refill cartridge 9, and a second electrical contact portion 15 may be provided on the mounting portion 11, for example, the inner body 112. When the toner refill cartridge 9 is mounted on the mounting portion 11, the first electrical contact portion 94 and the second electrical contact portion 15 may be electrically connected to each other. A control portion that is not shown may determine whether the toner refill cartridge 9 is mounted on the mounting portion 11 from an electrical connection signal input through the first electrical contact portion 94 and the second electrical contact portion 15. When the toner refill cartridge 9 is mounted on the mounting portion 11, the first connecting portion 133 provided on the inlet shutter 13 and the second connecting portion 932 provided on the discharge shutter 93 of the toner refill cartridge 9 are connected to each other. The control portion drives the driving motor 101 to rotate the inlet shutter 13. The discharge shutter 93 rotates together with the inlet shutter 13. When the inlet shutter 13 is out of the blocking position, the second cam 134-2 interferes with the interfering portion 143. The second cam 134-2 pivots the locking member 14 to the locking position as shown in FIG. 9. The locking portion 142 is inserted into the inner body 112 through a groove 112b provided in the inner body 112, and is caught by the locking hook 912 provided on the front end 911 of the toner refill cartridge 9. Thus, the toner refill cartridge 9 is locked to the mounting portion 11.

[0035] The second cam 134-2 interferes with the interfering portion 143 until the inlet shutter 13 reaches the inlet position, and the locking member 14 is held in the locking position. Accordingly, leakage of toner and damage to the inlet shutter 13 and the discharge shutter 93 due to arbitrary removal of the toner refill cartridge 9 may be prevented. When the inlet shutter 13 rotates 180 degrees, for example, the inlet shutter 13 reaches the inlet position. The discharge shutter 93 reaches the discharge position. The control portion (not shown) may determine whether the inlet shutter 13 has reached the inlet position from control information such as the driving time of the driving motor 101 and the number of pulses of the driving signal applied to the driving motor 101 and stop the driving motor 101. Although not shown in the drawings, the control portion may determine whether the inlet shutter 13 has reached the inlet position from a signal from a sensor that detects the position of the inlet shutter 13 and stop the driving motor 101.

[0038] When the inlet shutter 13 reaches the inlet position, the discharge shutter 93 reaches the discharge position. The toner outlet 913 of the toner refill cartridge 9, the opening 931 of the discharge shutter 93, the opening 131 of the inlet shutter 13, and the toner inlet 122 of the toner inlet portion 12 are aligned. When the plunger 92 is pressed in the longitudinal direction B, the toner inside the body 91 may be supplied to the toner container 230 of the developing cartridge 2 through the toner inlet portion 12. Because the locking member 14 is held in the locking position, the toner refill cartridge 9 remains locked to the mounting portion 11. Accordingly, the toner outlet 913 of the toner refill cartridge 9, the opening 931 of the discharge shutter 93, the opening 131 of the inlet shutter 13, and the toner inlet 122 of the toner inlet portion 12 remain aligned such that toner leakage may be prevented during a toner injection process. In addition, arbitrary removal of the toner refill cartridge 9 may be prevented.

[0037] When the plunger 92 reaches the lower dead position, toner refill is completed. A toner refill completion signal may be input to the control portion by an electrical connection structure between the toner refill cartridge 9 and the mounting portion 11. The control portion drives the driving motor 101 to rotate the inlet shutter 13 from the inlet position to the blocking position. The discharge shutter 93 rotates together with the inlet shutter 13 to the closing position. Until the inlet shutter 13 reaches the blocking position, the second cam 134-2 remains interfered with the interfering portion 143 of the locking member 14, and the locking member 14 is maintained in the locking position. Accordingly, arbitrary removal of the toner refill cartridge 9, and toner leakage and damage to the inlet shutter 13 or the discharge shutter 93 due to the arbitrary removal may be prevented.

[0038] For example, when the inlet shutter 13 is rotated 180 degrees, the inlet shutter 13 is returned to the blocking position. The discharge shutter 93 returns to the closing position. The toner outlet 913 of the toner refill cartridge 9 and the opening 931 of the discharge shutter 93 are misaligned with each other, and the opening 131 of the inlet shutter 13 and the toner inlet 122 of the toner inlet portion 12 are misaligned with each other. The control portion may determine whether the inlet shutter 13 has reached the blocking position from control information such as the driving time of the driving motor 101 and the number of pulses of the driving signal applied to the driving motor 101 or the signal from the sensor, and stop the driving motor 101.

[0039] When the inlet shutter 13 is located in the blocking position, the first cam 134-1 faces the interfering portion 143 of the locking member 14. The first cam 134-1 pushes the interfering portion 143 to pivot the locking member 14 to the unlocking position as shown in FIG. 8. The locking portion 142 is spaced apart from the locking hook 912 of the toner refill cartridge 9. Thus, the toner refill cartridge 9 may be removed from the mounting portion 11.

[0040] Referring back to FIG. 7, a third cam 134-3 may be provided on the inlet shutter 13. The third cam 134-3 interferes with the interfering portion 143 of the locking member 14 when the inlet shutter 13 reaches the inlet position to generate an impact sound. The third cam 134-3 protrudes outward from the second cam 134-2. When the third cam 134-3 interferes with the interfering portion 143, a force is applied to the interfering portion 143 to pivot the locking member 14 to a position beyond the locking position. Because the locking portion 142 is caught by the locking hook 912 of the toner refill cartridge 9, the locking member 14 may not pivot beyond the locking position. Instead, the locking member 14 is bent elastically. When the interference between the interfering portion 143 and the third cam 134-3 ends, the inlet shutter 13 reaches the inlet position and the locking member 14 is elastically restored to its original state, resulting in impact sound and/or vibration. The third cam 134-3 may have a shape in which an amount of protrusion from the second cam 134-2 gradually increases from a front end 134~3a to a rear end 134~3b with respect to the rotation direction of the inlet shutter 13. According to this configuration, while the interfering portion 143 gently interferes with the front end 134-3a of the third cam 134-3, the locking member 14 may be elastically bent, and the locking member 14 is elastically restored to its original state as soon as the interfering portion 143 leaves the rear end 134-3b of the third cam 134-3, resulting in the impact sound and/or vibration.

[0041] In a structure in which the discharge shutter 93 is connected to the iniet shutter 13 and rotates by the driving motor 101, it is difficult for a user to know whether the iniet shutter 13 has reached the iniet position. According to the present example, the user may recognize that the iniet shutter 13 has reached the iniet position from the impact sound and/or vibration, and press the plunger 92 to supply the toner to the toner container 230. [0042] In addition, the control portion may determine whether the inlet shutter 13 has reached the inlet position from control information such as the driving time of the driving motor 101 and the number of pulses of the driving signal applied to the driving motor 101, and after stopping the driving motor 101, generate a visual and/or audible signal to the user through an output device to inform the user that the inlet shutter 13 is located in the inlet position. For example, the control portion may output toner injection information through a display of an operation panel. The control portion may output the toner injection information by turning on a flashing light. The control portion may output the toner injection information by generating a beep sound through a beeper.

[0043] 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.

Claims

WHAT IS CLAIMED IS:

1. An image forming apparatus comprising: a main body; a developing cartridge comprising: a toner container to contain a toner, a mounting portion to/from which a toner refill cartridge is attachable/detachable, a toner inlet portion to connect the mounting portion to the toner container, and an inlet shutter switchable between a blocking position to block the toner inlet portion and an inlet position to open the toner inlet portion, the inlet shutter to supply the toner contained in the toner container to an electrostatic latent image formed on a photosensitive drum; and a locking member installed on the mounting portion and switchable between a locking position to lock the toner refill cartridge to the mounting portion and an unlocking position to allow attachment and detachment of the toner refill cartridge in conjunction with the inlet shutter.

2. The image forming apparatus of claim 1, wherein when the inlet shutter is in the blocking position, the locking member is in the unlocking position, and when the inlet shutter is out of the blocking position, the locking member is in the locking position.

3. The image forming apparatus of claim 1, wherein the iniet shutter rotates to the blocking position and the inlet position, and wherein the locking member interferes with the inlet shutter and pivots between the locking position and the unlocking position.

4. The image forming apparatus of claim 3, wherein the locking member comprises: a pivot shaft, a locking portion extending from the pivot shaft and caught by a locking hook of the toner refill cartridge to lock the toner refill cartridge to the mounting portion, and an interfering portion extending from the pivot shaft in a direction opposite to the locking portion, and the inlet shutter comprises a first cam to interfere with the interfering portion such that the locking member is in the unlocking position when the inlet shutter is in the blocking position and a second cam to interfere with the interfering portion to pivot the locking member to the locking position when the inlet shutter is out of the blocking position.

5. The image forming apparatus of claim 4, wherein the inlet shutter comprises a third cam protruding from the second cam, to interfere with the interfering portion when the inlet shutter reaches the inlet position to generate an impact sound.

6. The image forming apparatus of claim 5, wherein an amount of protrusion of the third cam from the second cam gradually increases from a front end to a rear end of the third cam with respect to a rotation direction of the inlet shutter.

7. The image forming apparatus of claim 1 , further comprising a driving motor to drive the inlet shutter.

8. The image forming apparatus of claim 7, wherein the toner refill cartridge comprises a body to contain the toner, a toner outlet through which the toner is dischargeable from the body, and a discharge shutter coupled to the inlet shutter and switchable between a discharge position and a closing position to open and close the toner outlet.

9. The image forming apparatus of claim 8, wherein the discharge shutter is switched to the closing position and the discharge position as the inlet shutter is switched to the biocking position and the inlet position.

10. The image forming apparatus of claim 8, wherein the main body comprises a communicating portion to allow the toner refill cartridge to be mounted on the mounting portion from outside, and the toner refill cartridge comprises a syringe type toner refill cartridge comprising the body and a plunger movably coupled to the body in a longitudinal direction to push the toner through the toner outlet.

11. A developing cartridge comprising: a toner container to contain toner; a mounting portion to/from which a toner refill cartridge is attachable/detachable; a toner inlet portion to connect the mounting portion to the toner container; an inlet shutter switchable between a blocking position to block the toner inlet portion and an inlet position to open the toner inlet portion; and a locking member installed on the mounting portion and switchable between a locking position to lock the toner refill cartridge to the mounting portion and an unlocking position to allow attachment and detachment of the toner refill cartridge in conjunction with the inlet shutter

12. The developing cartridge of claim 11, wherein, when the inlet shutter is in the blocking position, the locking member is in the unlocking position, and when the inlet shutter is out of the blocking position, the locking member is in the locking position.

13. The developing cartridge of claim 12, wherein the locking member comprises: a pivot shaft, a locking portion extending from the pivot shaft and caught by a locking hook of the toner refill cartridge to lock the toner refill cartridge to the mounting portion, and an interfering portion extending from the pivot shaft in a direction opposite to the locking portion, and the inlet shutter comprises a first cam to interfere with the interfering portion such that the locking member is in the unlocking position when the inlet shutter is in the blocking position and a second cam to interfere with the interfering portion to pivot the locking member to the locking position when the inlet shutter is out of the blocking position.

14. The developing cartridge of claim 13, wherein the inlet shutter comprises a third cam to interfere with the interfering portion when the inlet shutter is in the inlet position to generate an impact sound.

15. The developing cartridge of claim 14, wherein an amount of protrusion of the third cam from the second cam gradually increases from a front end to a rear end of the third cam with respect to a rotation direction of the inlet shutter.