BACKGROUND

[0001] An image forming apparatus may include a printing portion, a paper cassette in which print media may be loaded, and a paper feeding portion to withdraw a print medium from the paper cassette and supply the print medium to the printing portion. The paper feeding portion may include a plurality of rollers to transport the print medium. The paper feeding portion may also include a multifeeding preventing portion to separate the print media picked up from the paper cassette one by one and transfer the print media to the printing portion, in order to prevent multi-feeding of the print media. In a paper feeding process, a paper feeding error, for example, a jam of the print medium may occur. In that case, a structure to remove the jam of the print medium may be provided. Some components forming the multi-feeding preventing portion may be consumable components and may be replaced at the end of their life.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Various examples will be described below by referring to the following figures.

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

[0004] FIG. 2 is an exploded perspective view of a structure to move a separation roller in conjunction with an attachment/detachment operation of a paper cassette according to an example.

[0005] FIG. 3 is a perspective view showing a state in which a roller holder is positioned in a release position according to an example.

[0006] FIG. 4 is a cross-sectional view showing a state in which the roller holder is positioned in the release position according to an example.

[0007] FIG. 5 is a perspective view showing a state in which the roller holder is positioned in a pressurization position according to an example.

[0008] FIG. 6 is a cross-sectional view showing a state in which the roller holder is positioned in the pressurization position according to an example.

[0009] FIGS. 7 and 8 are perspective views showing a process of separating a roller holder from a frame according to an example.

DETAILED DESCRIPTION

[0010] An image forming apparatus may include a paper feeding portion to withdraw a print medium from a paper cassette on which print media are loaded and supply the print medium to a printing portion. The paper feeding portion may include a pickup roller to pick up the print medium from the paper cassette, and a forward roller and a separation roller that engage with each other to form a separation nip to prevent multi-feeding. The forward roller and the separation roller are to separate the print media picked up one by one and supply the print media to the printing portion. A jam of the print medium may occur during a paper feeding process. In that case, the separation roller may be spaced from the forward roller to facilitate removal of the jam of the print medium. The separation roller may be a consumable component that may be replaced at the end of its life. In that case, a structure in which the separation roller may be replaced may be provided.

[0011] An example image forming apparatus includes a paper cassette that is attachable/detachable to/from a main body of the image forming apparatus, a forward roller, and a separation roller that is movable (e.g., rotatable) between a position at which the separation roller is to engage with the forward roller and a position at which the separation roller is spaced from the forward roller, in conjunction with attachment/detachment operations of the paper cassette. The separation roller is to engage with the forward roller to form the separation nip for preventing multi-feeding of the print media picked up from the paper cassette. Based on the paper cassette being removed, the separation roller may be spaced apart from the forward roller, thereby allowing for removal of the jam of the print medium caused during the paper feeding process. Based on the paper cassette being mounted in the main body, the separation roller is to engage with the forward roller to enable paper feeding. Since the separation roller is moved with respect to the forward roller by the attachment/detachment operations of the paper cassette, there is no need for an actuator or a user operable lever for moving the separation roller with respect to the forward roller.

[0012] As an example, the separation roller may be supported on a roller holder. The roller holder may be rotated between a pressurization position in which the separation roller engages with the forward roller and a release position in which the separation roller is spaced apart from the forward roller. A spring holder may be connected to the roller holder. A first elastic member may apply an elastic force to the spring holder so that the roller holder is rotated to the pressurization position. A moving member may be movable between a first position and a second position. The first position is a position that allows the roller holder to be rotated to the pressurization position by the elastic force of the first elastic member, and the second position is a position to rotate the roller holder to the release position. For example, a first interfering portion may be provided in the spring holder, and a second interfering portion may be provided in the moving member. Based on the moving member being moved between the first position and the second position, the second interfering portion may interfere with the first interfering portion to pull the spring holder in a direction opposite to the elastic force of the first elastic member so that the roller holder may be rotated between the pressurization position and the release position. Based on the moving member being moved between the second position and the first position, the second interfering portion may be spaced apart from the first interfering portion so that the spring holder may be moved in the direction of the elastic force of the first elastic member and the roller holder may be rotated between the release position and the pressurization position. The moving member may be pushed against the paper cassette based on the paper cassette being mounted in the main body and moved between the second position and the first position. The second elastic member may apply the elastic force to the moving member in a direction in which the moving member is to move to the second position. Based on the paper cassette being detached from the main body, the moving member may be moved between the first position and the second position by the elastic force of the second elastic member.

[0013] As an example, the roller holder may be installed in a frame including an opening portion opened in the opposite direction of the paper cassette so as to be rotatable between the pressurization position and the release position. The roller holder may be separably installed in the frame through the opening portion. The spring holder may be separably connected to the roller holder. For example, a first catching portion opened in the opposite direction of the paper cassette may be provided in the spring holder, and a second catching portion having a shape complementary to that of the first catching portion and to be caught in the first catching portion separably in the opposite direction of the paper cassette may be provided in the roller holder. The first elastic member and the spring holder may remain in the main body and the roller holder and the separation roller may be separated and replaced, and thus the cost of consumables may be reduced. The separation roller and roller holder may be replaced in the opposite direction of the paper cassette, and thus a replacement job of the separation roller is easy. As an example, a pair of pivot pins may protrude from an inner wall of the opening portion of the frame. The roller holder may include a pair of resilience arms that are shrinkable and a pair of pivot holes provided in the pair of resilience arms into which the pair of pivot pins may be inserted. The pair of pivot pins may be released from the pair of pivot holes by accessing the pair of resilience arms through the opening portion provided in the frame and shrinking the pair of resilience arms, and thus the roller holder may be separated from the frame. The pair of resilience arms may protrude from the opening portion in the opposite direction of the paper cassette. Hereinafter, examples of the image forming apparatus will be described with reference to the accompanying drawings. In addition, in the present specification and drawings, elements having substantially the same function are denoted by the same reference numerals, and thus redundant descriptions thereof are omitted.

[0014] FIG. 1 is a schematic diagram of an image forming apparatus according to an example.

[0015] Referring to FIG. 1 , an image forming apparatus includes a paper cassette 4 attachable/detachable to/from a main body 1 of the image forming apparatus, a forward roller 101 , and a separation roller 102 movable between a position (a position shown by a solid line) at which the separation roller 102 engages with the forward roller 101 and a position (a position shown by a dotted line) at which the separation roller 102 is spaced from the forward roller 101 , in conjunction with attachment/detachment operations of the paper cassette 4. A pickup roller 103 is to pick up print media P loaded on the paper cassette 4. The print media P that are picked up are supplied to a printing portion 3 along a path 291 by the forward roller 101 and the separation roller 102.

[0016] The printing portion 3 is provided in the main body 1. The printing portion 3 is to print an image on the print medium P using any of various printing methods such as an electrophotographic method, an inkjet method, and the like. In the described example, the printing portion 3 is to print a color image on the print medium P using the electrophotographic method. Referring to FIG. 1 , a plurality of developing devices 210, an exposure device 250, an intermediate transfer belt 260, a transfer roller 270, and a fuser 280 are illustrated. The plurality of developing devices 210 may include four developing devices 210 for forming toner images of yellow (Y), magenta (M), cyan (C), and black (K) colors. Developers of cyan (C), magenta (M), yellow (Y), and black (K) colors may be contained in the four developing devices 210, respectively. The developers of yellow (Y), magenta (M), cyan (C), and black (K) colors may be supplied to the four developing devices 210, respectively, from four developer cartridges 220 in which the developers of yellow (Y), magenta (M), cyan (C), and black (K) colors are contained. The developer may include, for example, a toner, or a toner and a carrier. The developing device 210 may include a photosensitive drum 212 and a developing roller 211. A charging roller 215 is to charge a photosensitive drum 212 to have a uniform electric surface potential. The exposure device 250 is to irradiate the photosensitive drum 212 with light modulated in correspondence to image information to form an electrostatic latent image on the photosensitive drum 212. The developing roller 211 is to supply the toner contained in the developing device 210 to a developing area opposed to the photosensitive drum 212. The toner is supplied to the electrostatic latent image across the developing area by a developing bias voltage applied to the developing roller 211 , and the electrostatic latent image is developed into a visible toner image. The intermediate transfer belt 260 is supported by a plurality of support rollers 262, 263, 264, and 265 and circulated. Four intermediate transfer rollers 261 are respectively arranged at positions facing the photosensitive drums 212 of the four developing devices 210 with the intermediate transfer belt 260 therebetween. The toner image developed on the photosensitive drum 212 is intermediately transferred to the intermediate transfer belt 260 by an intermediate transfer bias voltage applied to the intermediate transfer roller 261. A cleaning member 217 removes the developer remaining on the surface of the photosensitive drum 212 after an intermediate transfer process. The transfer roller 270 is positioned to face the intermediate transfer belt 260 to form a transfer nip. The print medium P is picked up from the paper cassette 4 by the pickup roller 103 and supplied between the forward roller 101 and the separation roller 102. The forward roller 101 and the separation roller 102 are to separate the print media P that are picked up one by one and are supplied to the transfer nip along the path 291 . The toner image on the intermediate transfer belt 260 is transferred to the print medium P by a transfer bias voltage applied to the transfer roller 270. The fuser 280 is to apply heat and pressure to the toner image transferred to the print medium P to fix the toner image on the print medium P. The print medium P on which printing is completed is discharged by a discharge roller 292.

[0017] A jam may occur in a process of withdrawing the print medium P from the paper cassette 4 and supplying the print medium P to the printing portion 3. The separation roller 102 is to engage with the forward roller 101 to form a separation nip 104 to prevent multi-feeding of the print medium P picked up from the paper cassette 4. Based on two or more sheets of print media P entering the separation nip 104, one of the two or more sheets of print media P is separated and supplied to the printing portion 3. The separation nip 104 may be released based on the separation roller 102 being spaced apart from the forward roller 101 . In an example, the separation roller 102 may be moved, for example, rotated, between a position at which the separation roller 102 is to engage with the forward roller 101 and a position at which the separation roller 102 is spaced apart from the forward roller 101 .

[0018] In an example, the movement of the separation roller 102 may be linked to the attachment/detachment operations of the paper cassette 4 to/from the main body 1 . Based on the paper cassette 4 being moved in a mounting direction A1 and mounted in the main body 1 , the separation roller 102 is to engage the forward roller 101 to form the separation nip 104. Based on the paper cassette 4 being pulled in a removal direction A2 and removed from the main body 1 , the separation roller 102 may be spaced apart from the forward roller 101 and the separation nip 104 may be released. Based on a jam of the print medium P occurring during a paper feeding process, the paper cassette 4 may be removed from the main body 1 so as to remove the jam. The separation roller 102 may be moved to a position at which the separation nip 104 is released by a removal operation of the paper cassette 4. The separation nip 104 may be released so that the print medium P between the forward roller 101 and the separation roller 102 may be removed. After the jam is removed, the separation roller 102 may be moved to a position at which the separation nip 104 is formed by an operation of mounting the paper cassette 4 to the main body 1 . Accordingly, an operation of the user for removing the jam and thereafter performing a printing operation is simplified, and thus user convenience may be improved. In an example, an actuator to move the separation roller 102, a control component to control the actuator, or a lever provided to be operated by the user to move the separation roller 102 are not provided. Thus, the material cost of the image forming apparatus may be reduced.

[0019] An example structure for moving the separation roller 102 in conjunction with the attachment/detachment operations of the paper cassette 4 may be implemented by various mechanisms.

[0020] FIG. 2 is an exploded perspective view of a structure to move the separation roller in conjunction with attachment/detachment operations of the paper cassette according to an example. FIGS. 3 and 4 are respectively a perspective view and a cross-sectional view showing a state in which the roller holder is positioned in a release position according to an example. FIGS. 5 and 6 are respectively a perspective view and a cross-sectional view showing a state in which the roller holder is positioned at a pressurization position according to an example. In FIGS. 4 and 6, a frame 190 is omitted for clarity.

[0021] Referring to FIGS. 2 to 6, the separation roller 102 may be rotatably supported by a roller holder 120. For example, a rotation shaft (not shown) may be provided on the roller holder 120. The separation roller 102 may be installed on the rotation shaft with a torque limiter 105 interposed therebetween. The separation roller 102 may be driven by the forward roller 101. Based on a torque applied to the separation roller 102 by the rotation of the forward roller 101 being greater than a threshold torque of the torque limiter 105, the separation roller 102 may be rotated with respect to the rotation shaft. Based on the torque applied to the separation roller 102 by the rotation of the forward roller 101 being smaller than the threshold torque of the torque limiter 105, the separation roller 102 is not rotated.

[0022] The roller holder 120 is rotatable between the pressurization position (FIGS. 5 and 6) at which the separation roller 102 is to engage with the forward roller 101 and the release position (FIGS. 3 and 4) at which the separation roller 102 is spaced apart from the forward roller 101. The roller holder 120 may be installed on the frame 190 to be rotatable between the pressurization position and the release position. For example, a pair of pivot pins 193 may be provided on the frame 190. A pair of pivot holes 122 into which the pair of pivot pins 193 may be inserted may be provided in the roller holder 120. The roller holder 120 may be rotated between the pressurization position and the release position by using the pair of pivot pins 193 as a shaft. Although not shown in the drawings, the pair of pivot holes 122 may be provided in the frame 190 and the pair of pivot pins 193 may be provided in the roller holder 120 in an example.

[0023] A first elastic member 140 is to apply an elastic force to the roller holder 120 so as to be rotated in a direction toward the pressurization position. For example, the first elastic member 140 may apply the elastic force to the roller holder 120 with a spring holder 130 interposed therebetween. The spring holder 130 may be connected to the roller holder 120. The spring holder 130 may be located in a lower portion of the roller holder 120. The spring holder 130 may be installed on the frame 190 to be lifted up and down in a vertical direction. A stopper 133 of the spring holder 130 may be caught on a catching protrusion 196 of the frame 190 so that the spring holder 130 does not break away from the frame 190. The first elastic member 140 is to apply an upward elastic force to the spring holder 130. For example, the first elastic member 140 may be implemented by a compression coil spring having one end and the other end respectively supported by the spring holder 130 and the frame 190.

[0024] The roller holder 120 may be rotated between the pressurization position and the release position in conjunction with attachment/detachment operations of the paper cassette 4. The roller holder 120 may be rotated between the pressurization position by the elastic force of the first elastic member 140 based on the paper cassette 4 being mounted in the main body 1 , and the release position based on the paper cassette 4 being removed from the main body 1 . The roller holder 120 may be rotated between the pressurization position and the release position by allowing the spring holder 130 to be moved in a direction of the elastic force of the first elastic member 140 or pulling the spring holder 130 in the opposite direction to the elastic force of the first elastic member 140.

[0025] As an example, a first interfering portion 131 may be provided in the spring holder 130. An image forming apparatus may include a moving member 150. The moving member 150 may include a second interfering portion 151. The moving member 150 may be moved between a first position (FIGS. 5 and 6) at which the roller holder 120 is rotated to the pressurization position and a second position (FIGS. 3 and 4) at which the roller holder 120 is rotated to the release position in conjunction with the attachment/detachment operations of the paper cassette 4. A moving direction of the moving member 150 may be the same as a detachment direction of the paper cassette 4. At the first position, the second interfering portion 151 may be spaced apart from the first interfering portion 131 so that the roller holder 120 is positioned at the pressurization position by the elastic force of the first elastic member 140. At the second position, the second interfering portion 151 may interfere with the first interfering portion 131 so that the roller holder 120 is rotated to the release position.

[0026] The moving member 150 may be supported by the frame 190 so as to be movable between the first position and the second position. For example, a guide rail 194 may be provided in the frame 190, and a guide groove 153 into which the guide rail 194 may be inserted may be provided in the moving member 150. In order to prevent the moving member 150 from breaking away from the frame 190 beyond the second position, a stopper 195 and a catching groove 152 may be respectively provided in the frame 190 and the moving member 150. Based on the moving member 150 reaching the second position, the stopper 195 may be caught on an end of the catching groove 152 so that the moving member 150 is maintained at the second position. The moving member 150 may be pushed by the paper cassette 4 mounted in the main body 1 and moved between the second position and the first position. A second elastic member 160 is to apply an elastic force to the moving member 150 in a direction toward the second position. Based on the paper cassette 4 being removed from the main body 1 , the moving member 150 may be moved between the first position and the second position by the elastic force of the second elastic member 160. For example, the second elastic member 160 may be implemented by a compression coil spring having one end and the other end supported by the moving member 150 and the frame 190, respectively. The first interfering portion 131 may have, for example, a projection shape protruding from the spring holder 130. The second interfering portion 151 may include a first part 151 -1 to interfere with the first interfering portion 131 and pull the spring holder 130 in the opposite direction of the elastic force of the first elastic member 140 based on the moving member 150 being positioned at the second position, and a second part 152-2 to interfere with the first interfering portion 131 and guide the first interfering portion 131 to the first part 151 -1 based on the moving member 150 being moved between the first position and the second position. The second part 151 -2 may extend inclinedly upward from the first part 151 -1 in the removal direction A2.

[0027] An example moving process of the separation roller 102 is described with reference to FIGS. 2 to 6. Referring to FIGS. 3 and 4, the paper cassette 4 has been removed from the main body 1 . The moving member 150 is positioned at the second position by the elastic force of the second elastic member 160. The stopper 195 is caught on the end of the catching groove 152 so that the moving member 150 is maintained at the second position. The first interfering portion 131 is caught on the first part 151 -1 of the second interfering portion 151 . The first elastic member 140 is compressed so that the spring holder 130 pulls the roller holder 120 so that the roller holder 120 is positioned at the release position. The separation roller 102 is spaced apart from forward roller 101 and the separation nip 104 is released.

[0028] In this state, the paper cassette 4 may be pushed in the mounting direction A1 and mounted in the main body 1 . A leading end 41 of the paper cassette 4 may be in contact with the moving member 150. As the paper cassette 4 is moved in the mounting direction A1 , the moving member 150 may be moved between the second position and the first position. The first interfering portion 131 may be guided to the second part 151 -2 of the second interfering portion 151 , and the spring holder 130 may be lifted by the elastic force of the first elastic member 140. The spring holder 130 may push and rotate the roller holder 120 from the release position to the pressurization position. Based on the paper cassette 4 reaching a mounting position, the moving member 150 may reach the first position as shown in FIGS. 5 and 6. The interference of the first interfering portion 131 and the second interfering portion 151 end, and the roller holder 120 may reach the pressurization position. The separation roller 102 may be in contact with the forward roller 101 , and the separation roller 102 may be pressed against the forward roller 101 by the elastic force of the first elastic member 140 to form the separation nip 104.

[0029] In this state, a print job may be performed. For example, the pickup roller 103 may pick up the print media P loaded on the paper cassette 4 and supply the print media P to the separation nip 104. Based on one sheet of print medium P entering the separation nip 104, a forward torque applied to the separation roller 102 may be greater than a threshold torque of the torque limiter 105 by the print medium P transported in a forward direction by the forward roller 101. The separation roller 102 may be rotated with respect to a rotation shaft together with the forward roller 101 . One sheet of print medium P may be supplied to the printing portion 3 along the path 291 . Based on a plurality of sheets of print media P, for example, two sheets of print media P, entering the separation nip 104, the forward torque applied to the separation roller 102 may be smaller than the threshold torque of the torque limiter 105 by a friction force between the two sheets of print media P. In that case, the separation roller 102 may not be rotated. In the two sheets of print media P, the print medium P in contact with the separation roller 102 may not be transported, whereas the print medium P in contact with the forward roller 101 may be supplied to the printing portion 3 along the path 291 . The printing portion 3 may print an image on the print medium P. The print medium P on which printing is completed may be discharged to the outside of the main body 1 .

[0030] Based on a jam of the print medium P occurring during a paper feeding process, a control portion (not shown) may stop the print job and output a notification indicating that the jam has occurred through a user interface (not shown). To remove the jammed print medium P, the paper cassette 4 may be pulled in the removal direction A2 and removed from the main body 1 . As the paper cassette 4 is moved away from the mounting position in the removal direction A2, the moving member 150 may be moved between the first position and the second position by the elastic force of the second elastic member 160. As the second part 151 -2 of the second interfering portion 151 interferes with the first interfering portion 131 , the spring holder 130 may be pulled in a direction opposite to the elastic force of the first elastic member 140. The roller holder 120 connected to the spring holder 130 may be rotated between the pressurization position and the release position. As shown in FIGS. 3 and 4, based on the moving member 150 reaching the second position, the first interfering portion 131 may be caught on the first part 151-1 of the second interfering portion 151. The roller holder 120 may reach the release position, and the separation nip 104 may be released. The forward roller 101 and the separation roller 102 may be spaced apart from each other, and thus the jammed print medium P may be easily removed. Based on the paper cassette 4 being mounted in the main body 1 after the jammed print medium P is removed, the moving member 150 may be moved to the first position and the roller holder 120 may be moved to the pressurization position so that the separation nip 104 is formed as described above.

[0031] As described above, the separation roller 102 may be a consumable that is replaced at the end of its life. In an example, the image forming apparatus may have a structure in which the separation roller 102 may be replaceable. For example, the roller holder 120 on which the separation roller 102 is supported may be separated from the main body 1 , and a new roller holder 120 and the separation roller 102 may be mounted in the main body 1. After removing the roller holder 120 from the main body 1 , the separation roller 102 may be removed from the roller holder 120, and after assembling the new separation roller 102 to the roller holder 120, the roller holder 120 may be mounted in the main body 1. In an example, the image forming apparatus has a structure in which the separation roller 102 is replaceable in the opposite direction of the paper cassette 4. An example of a structure in which the separation roller 102 is replaceable is described with reference to FIGS. 1 to 6.

[0032] Referring to FIGS. 1 and 2, an opening portion 191 to be opened in the opposite direction of the paper cassette 4 may be provided in the frame 190. The roller holder 120 may be separably installed in the frame 190 through the opening portion 191. For example, the pair of pivot pins 193 protruding inwardly may be provided on an inner wall 192 of the opening portion 191. A pair of resilience arms 121 shrinkable inwardly, that is, in a direction closer to each other, may be provided in the roller holder 120. A pair of pivot holes 122 into which a pair of pivot pins 193 may be inserted may be provided in the pair of resilience arms 121. After aligning the pair of pivot holes 122 and the pair of pivot pins 193 by shrinking the pair of resilience arms 121 , based on a force shrinking the pair of resilience arms 121 being removed, the pair of pivot pins 193 may be inserted into the pair of pivot holes 122. The roller holder 120 may be supported by the frame 190 so as to be rotatable between the pressurization position and the release position by using the pair of pivot pins 193 as a shaft. Based on the roller holder 120 being separated from the frame 190, the pair of pivot holes 122 may be separated from the pair of pivot pins 193 by shrinking the pair of resilience arms 121.

[0033] In a structure in which the first elastic member 140 directly applies an elastic force to the roller holder 120, it may be difficult to remove the roller holder 120. In this case, the first elastic member 140 may also be removed and replaced, which leads to an increase in the cost of consumables. In an example, the first elastic member 140 may apply an elastic force to the roller holder 120 with the spring holder 130 interposed therebetween. The spring holder 130 may be separably connected to the roller holder 120. For example, referring to FIGS. 4 and 6, a first catching portion 132 opened in the opposite direction of the paper cassette 4, that is, in the mounting direction A1 may be provided in the spring holder 130. A second catching portion 123 may be provided in the roller holder 120. The second catching portion 123 may have a shape complementary to that of the first catching portion 132. That is, the second catching portion 123 may have a shape opened in the direction of the paper cassette 4. Accordingly, the second catching portion 123 may be moved in the opposite direction of the paper cassette 4 and separated from the first catching portion 132. In this example, the first elastic member 140 and the spring holder 130 may remain in the main body 1 , and the roller holder 120 on which the separation roller 102 is supported may be separated from the frame 190, and thus the cost of replacing consumables may be reduced.

[0034] FIGS. 7 and 8 are perspective views showing a process of separating the roller holder 120 from the frame 190 according to an example. An example of a method of replacing the separation roller 102 is described with reference to FIGS. 1 to 8. Referring to FIG. 1 , a door 2 is to open and close a part of the main body 1. For example, the door 2 may open or close the part of the main body 1 so that the opening portion 191 provided in the frame 190 is exposed. The roller holder 120 may be mounted/removed to/from the frame 190 through the opening portion 191 of the frame 190 by opening the door 2.

[0035] The door 2 may be opened as shown by a dotted line in FIG. 1 . As shown in FIG. 7, the opening portion 191 of the frame 190 may be exposed. The pair of resilience arms 121 of the roller holder 120 may be partially exposed to the rear of the frame 190 through the opening portion 191 . A user may shrink (e.g. , squeeze) the pair of resilience arms 121 inwardly, for example, in a direction closer to each other. The pair of pivot pins 193 may be released from the pair of pivot holes 122 provided in the pair of resilience arms 121. In this state, as shown in FIG. 8, the roller holder 120 may be pulled in the opposite direction of the paper cassette 4 and separated from the frame 190 through the opening portion 191. As shown in FIG. 3, the first catching portion 132 of the spring holder 130 has a shape opening in the opposite direction of the paper cassette 4, and thus the second catching portion 123 of the roller holder 120 may be naturally separated from the first catching portion 132.

[0036] In order to mount the roller holder 120 on which the new separation roller 102 is supported on the frame 190, the roller holder 120 may be inserted into the opening portion 191 . The pair of pivot holes 122 and the pair of pivot pins 193 are aligned by shrinking (e.g., squeezing) the pair of resilience arms 121. A force to shrink the pair of resilience arms 121 may be removed. The pair of pivot pins 193 may be inserted into the pair of pivot holes 122. As shown in FIG. 3, the first catching portion 132 of the spring holder 130 has a shape opening in the opposite direction to the paper cassette 4, and thus the second catching portion 123 of the roller holder 120 may be naturally connected to the first catching portion 132. The roller holder 120 may be supported by the frame 190 so as to be rotatable between the pressurization position and the release position by using the pair of pivot pins 193 as a shaft.

[0037] According an example, lifting or partially disassembling the main body 1 of an image forming apparatus may be avoided in order to replace the separation roller 102. For example, the door 2 may open and close a rear surface of the main body 1 , and access the separation roller 102 from the rear of the main body 1 to replace the separation roller 102. Replacement of the separation roller 102 may be performed with the roller holder 120 positioned at the release position. To this end, before replacing the separation roller 102, the paper cassette 4 may be moved away from the mounting position in the removal direction A2 so that the moving member 150 may be positioned at the second position. The first interfering portion 131 of the spring holder 130 may be caught on the first part 151-1 of the second interfering portion 151 provided in the moving member 150. The elastic force of the first elastic member 140 may be applied to the spring holder 130 and may not be applied to the roller holder 120 positioned at the release position. Also, the separation roller 102 may be spaced apart from the forward roller 101 . Therefore, a replacement job of the roller holder 120 may be easy. [0038] Examples described herein should be considered in a descriptive sense 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 examples have been described with reference to the figures, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.