Image forming apparatus

Abstract

The present invention provides an image forming apparatus equipped with a highly functional and easy-to-operate restricting mechanism that prevents the opening of the outer cover during image forming operations. [Solution] The image forming apparatus comprises a cover supported on the apparatus body so as to be openable and closable, a drive source provided on the apparatus body that generates a driving force to perform an image forming operation, a transmission gear provided on the apparatus body that rotates by the driving force generated by the drive source, and a restricting mechanism 65 that restricts the opening of the cover while the image forming operation is being performed. The restricting mechanism 65 comprises a drive gear 71 that meshes with the transmission gear when the cover is closed, a locking member 73 that rotates around the drive gear 71 between a locked position in which it engages with the apparatus body and a released position in which it is released from engagement with the apparatus body, a torque limiter disposed between the locking member 73 and the drive gear 71, and a biasing member 77 that biases the locking member 73 to the released position.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus including an outer cover that opens and closes a conveyance path.

Background Art

[0002] An image forming apparatus such as a copying machine or a printer may include a device main body and an outer cover that is provided to be openable and closable with respect to the device main body, and may be configured to form a paper conveyance path between the device main body and the outer cover. In this configuration, by opening the outer cover, the conveyance path is opened, and paper jams occurring in the conveyance path can be processed. If the outer cover is accidentally opened during the image forming operation, the image forming operation is stopped. Then, the conveyance of paper stops, and paper jams may occur in the conveyance path.

[0003] Therefore, an image forming apparatus may be provided with means for preventing the outer cover from being opened during the image forming operation. The blocking means described in Patent Document 1 includes a torque limiter connected to the paper feed shaft of a paper feed roller that feeds paper during the image forming operation. The torque limiter is provided with a lever that can engage with a reverse guide (corresponding to the outer cover). During the image forming operation, the lever engages with the reverse guide, preventing the reverse guide from being opened. During this time, the paper feed shaft idles with respect to the torque limiter. On the other hand, when the image forming operation stops, the torque limiter is urged so that the lever separates from the reverse guide.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, by utilizing the operation of a torque limiter connected to a drive member (e.g., a paper feed shaft) that is driven during the image forming operation, opening and closing members such as reversing guides and outer covers can be engaged with or disengaged from the main body of the device in conjunction with the image forming operation. On the other hand, it is necessary to select the arrangement and configuration of drive members and torque limiters considering the functionality, operability, and maintainability of the image forming device. For example, in the blocking means described in Patent Document 1 above, a lever is directly provided on the torque limiter. Therefore, in order to engage the lever with the reversing guide, the torque limiter must be placed as close to the reversing guide as possible. In this way, the arrangement of torque limiters and drive members may be limited.

[0006] Therefore, the present invention aims to provide an image forming apparatus equipped with a regulating mechanism that is highly functional and easy to operate, which restricts the opening of the outer cover during image forming operation, taking the above circumstances into consideration. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides an image forming apparatus comprising: a cover supported on the apparatus body so as to be openable and closable; a drive source provided on the apparatus body for generating a driving force to perform an image forming operation; a transmission gear provided on the apparatus body for rotating in one direction by the driving force generated by the drive source; and a restricting mechanism for restricting the opening of the cover while an image forming operation is being performed, wherein the restricting mechanism comprises: a drive gear rotatably supported on the cover and meshing with the transmission gear when the cover is closed; a locking member that rotates around the drive gear between a locked position in which it engages with the apparatus body to restrict the opening of the cover and a released position in which it is released from engagement with the apparatus body; a torque limiter disposed between the locking member and the drive gear, which transmits the rotation of the drive gear to the locking member until a predetermined torque is applied, and causes the drive gear to rotate freely relative to the locking member when a torque exceeding the predetermined amount is applied; and a biasing member that biases the locking member to rotate to the released position.

[0008] In the present invention, while the image forming operation is being performed, the transmission gear rotates in one direction, causing the drive gear to rotate, the rotation of the drive gear is transmitted to the locking member by the torque limiter, causing the locking member to rotate to the locked position, after which the drive gear spins freely relative to the locking member, the image forming operation is completed and the rotation of the transmission gear in one direction stops, after which the transmission gear rotates in the opposite direction, the torque limiter rotates together with the drive gear and moves away from the locking member, causing the locking member to be biased by the biasing member and rotate to the released position.

[0009] The present invention may further include a transport unit disposed inside the cover and provided on the main body of the device in an openable and closable manner, wherein a paper transport path is formed between the transport unit and the cover.

[0010] The present invention further comprises a pair of conveying rollers that convey a sheet along the conveying path, including a drive roller supported by the cover and a driven roller supported by the conveying unit, and an input gear that is rotatably supported by the outer cover and engages with the transmission gear when the outer cover is closed to provide driving force to the drive roller, wherein the drive gear engages with the transmission gear via the input gear when the cover is closed. [Effects of the Invention]

[0011] According to the present invention, a regulating mechanism can be provided that includes a locking member that can be reliably rotated between an unlocked position and a locked position, and that can be installed in a limited space. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic front view showing the internal configuration of an image forming apparatus according to one embodiment of the present invention. [Figure 2] This is a side view showing the outer cover of an image forming apparatus according to one embodiment of the present invention. [Figure 3]This is a perspective view showing the regulatory mechanism of an image forming apparatus according to one embodiment of the present invention. [Figure 4] This is an exploded perspective view showing the regulatory mechanism of an image forming apparatus according to one embodiment of the present invention. [Figure 5] This is a cross-sectional view showing the regulating mechanism of an image forming apparatus according to one embodiment of the present invention (in a state where the locking member has been rotated to the released position). [Figure 6] This is a perspective view showing the regulating mechanism of an image forming apparatus according to one embodiment of the present invention (with the locking member rotated to the released position). [Figure 7] This is a cross-sectional view showing the regulating mechanism (torque limiter in a rotated state) of an image forming apparatus according to one embodiment of the present invention. [Figure 8] This is a cross-sectional view showing the regulating mechanism of an image forming apparatus according to one embodiment of the present invention (the state in which the locking member is rotated to the locked position). [Figure 9] This is a perspective view showing the regulating mechanism of an image forming apparatus according to one embodiment of the present invention (with the locking member rotated to the locked position). [Figure 10] This is a cross-sectional view showing the regulating mechanism (in the state where the drive gear is stopped) of an image forming apparatus according to one embodiment of the present invention. [Figure 11] This is a cross-sectional view showing the regulating mechanism (torque limiter in a rotated state) of an image forming apparatus according to one embodiment of the present invention. [Figure 12] This is a cross-sectional view showing the regulating mechanism of an image forming apparatus according to one embodiment of the present invention (in a state where the locking member has been rotated to the released position). [Modes for carrying out the invention]

[0013] The following describes an image forming apparatus according to one embodiment of the present invention, with reference to the drawings.

[0014] First, the overall configuration of the image forming apparatus 1 according to this embodiment will be described with reference to Figure 1. Figure 1 is a schematic cross-sectional view showing the internal structure of the image forming apparatus 1. Fr, Rr, L, and R shown in each figure indicate the front, rear, left, and right sides of the image forming apparatus 1, respectively.

[0015] The image forming apparatus 1 includes an apparatus main body 3, a conveyance unit 5, and an outer cover 7. The lower end portion of the conveyance unit 5 is rotatably supported by a rotation shaft 3a provided on the right side surface of the apparatus main body 3. The outer cover 7 is disposed outside the conveyance unit 5, and the lower end portion is rotatably supported by a rotation shaft 3b provided on the right side surface of the apparatus main body 3.

[0016] The apparatus main body 3 includes a paper feed cassette 11 for accommodating paper, a paper feed device 13 for feeding out the paper from the paper feed cassette 11, an image forming unit 15 for forming a toner image on the fed-out paper, a fixing device 17 for fixing the toner image formed on the paper to the paper, a discharging device 19 for discharging the paper on which the toner image is fixed, and a discharge tray 21 on which the discharged paper is stacked.

[0017] A main conveyance path 23 is formed between the apparatus main body 3 and the conveyance unit 5 along the conveyance direction in which the paper is conveyed from the paper feed device 13 through the image forming unit 15 and the fixing device 17 to the discharging device 19. A registration roller pair 25 is provided between the paper feed device 13 and the image forming unit 15 in the main conveyance path 23. The registration roller pair 25 includes a driving roller 25A supported by the apparatus main body 3 and a driven roller 25B supported by the conveyance unit 5.

[0018] An inversion conveyance path 27 is formed between the conveyance unit 5 and the outer cover 7, branching from the main conveyance path 23 upstream of the discharging device 19 and merging into the main conveyance path 23 downstream of the paper feed device 13. A plurality of conveyance roller pairs 29 are provided in the inversion conveyance path 27. The conveyance roller pair 29 includes a driving roller 29A supported by the outer cover 7 and a driven roller 29B supported by the conveyance unit 5.

[0019] The image forming operation is briefly explained below. The paper feeder 13 feeds paper from the paper feed cassette 11 to the main transport path 23. After the paper fed to the main transport path 23 is skew corrected by the registration roller pair 25, it is transported to the image forming unit 15. The image forming unit 15 forms a toner image on one side of the paper. The paper with the toner image formed is transported along the main transport path 23 from the image forming unit 15 to the fuser unit 17. The fuser unit 17 fixes the toner image to the paper. The paper with the fixed toner image is transported along the main transport path 23 from the fuser unit 17 to the discharge unit 19. The discharge unit 19 discharges the paper into the discharge tray 21. In the case of double-sided printing, the paper is switched back at the discharge unit 19 and sent to the reversal transport path 27. The paper is transported to the main transport path 23 via the inversion transport path 27, where a toner image is formed on the other side in the image forming unit 15 as described above, the toner image is fixed in the fuser unit 17, and then the paper is discharged into the discharge tray 21 by the discharge unit 19.

[0020] The image forming operation described above is performed using the driving force generated by a motor 31 located on the main body of the device 3. Thus, the motor 31 is an example of a drive source that generates the driving force to perform the image forming operation. The drive roller 25A of the registration roller pair 25 located on the main transport path 23 rotates due to the driving force generated by the motor 31. As a result, the paper skew is adjusted by the registration roller pair 25 and the paper is transported. In addition, a transmission gear 33 is rotatably supported on the main body of the device 3. The transmission gear 33 meshes directly or indirectly with the motor gear of the motor 31 and rotates in one direction and other directions due to the driving force generated by the motor 31.

[0021] The outer cover 7 will be described again with reference to Figures 1, 2, and 3. Figure 2 is a side view showing the outer cover 7, and Figure 3 is a perspective view showing the regulating mechanism 65 supported by the outer cover 7. The outer cover 7 has a main body portion 41 facing the reversing transport path 27, and front and rear side wall portions 43 provided at the front and rear of the main body portion 41. The side wall portion 43 has an L-shaped bottom plate 47 that is upside down when viewed from the front, and a side plate 49 erected along the periphery of the bottom plate 47, forming a horizontally elongated rectangular upper space 51 and a vertically elongated lower space 53 enclosed by the bottom plate 47 and the side plate 49.

[0022] A pin 55 is erected on the bottom plate 47 near the intersection of the upper space 51 and the lower space 53, oriented perpendicular to the paper transport direction. Furthermore, a rotating shaft 57 is erected below the pin 55, parallel to the pin 55. As shown in Figure 3, an input gear 59 is rotatably supported on the rotating shaft 57. The input gear 59 meshes with the transmission gear 33 (see Figure 1) of the device body 3 when the outer cover 7 is closed. The lower space 53 houses a drive gear, etc. (not shown) fixed to the end of the rotating shaft of the drive roller 29A of the transport roller pair 29. The drive gear meshes with the input gear 59 via a timing belt 61. As the input gear 59 rotates, the drive roller 29A rotates in a predetermined direction via the drive gear. As a result, the paper is transported along the reverse transport path 27 by the transport roller pair 29.

[0023] Furthermore, the outer cover 7 is rotatable between a closed position that forms the inversion transport path 27 and an open position that opens the inversion transport path 27. When the outer cover 7 is rotated to the closed position, it is housed inside the front and rear side plates of the main body 3 of the device. The outer cover 7 is equipped with a locking mechanism 63 that engages with the main body 3 when rotated to the closed position, and a restricting mechanism 65 that restricts the rotation of the outer cover 7 from the closed position to the open position while the image forming operation is being performed. The locking mechanism 63 maintains the outer cover 7 in the closed position, and when the outer cover 7 is rotated, the engagement between the main body 3 and the outer cover 7 is released. Therefore, it is possible that the outer cover 7 may be accidentally rotated during the image forming operation. If the outer cover 7 is rotated to the open position during the image forming operation, the image forming operation will stop. This may cause the paper transport to stop and a paper jam to occur. On the other hand, the restricting mechanism 65 restricts the rotation of the outer cover 7 from the closed position to the open position while the image forming operation is being performed. By providing such a restricting mechanism 65, it is possible to prevent the outer cover 7 from being accidentally rotated during the image forming operation. The locking mechanism 63 will not be explained.

[0024] The regulating mechanism 65 will be described with reference to Figures 2, 3, and 4. Figure 4 is an exploded perspective view showing the regulating mechanism 65. The regulating mechanism 65 comprises a drive gear 71 supported by the outer cover 7, a locking member 73 that rotates about the drive gear 71, a torque limiter 75 positioned between the locking member 73 and the drive gear 71, and a biasing member 77 (not shown in Figures 3 and 4, see Figure 5) positioned between the locking member 73 and the outer cover 7. The drive gear 71, locking member 73, torque limiter 75, and biasing member 77 are positioned in the upper space 51 of the front side wall portion 43 of the outer cover 7.

[0025] First, let's describe the drive gear 71. As shown in Figure 4, the drive gear 71 has a shaft hole portion 81, a small-diameter portion 83 arranged axially with respect to the shaft hole portion 81, a gear portion 85, and a large-diameter portion 87 that is smaller in diameter than the gear portion 85 and larger in diameter than the small-diameter portion 83. The drive gear 71 is housed in the gear housing portion 93 of the locking member 73, which will be described later, and is rotatably supported by a pin 55 erected on the bottom plate 47 of the upper space 51 of the outer cover 7. In detail, the pin 55 is inserted into the shaft hole portion 81, the small-diameter portion 83 is housed in the gear housing portion 93, and the gear portion 85 and the large-diameter portion 87 protrude from the gear housing portion 93. The gear portion 85 meshes with the input gear 59.

[0026] Next, the locking member 73 will be described. As shown in Figure 4, the locking member 73 has a rectangular base plate 91, a gear housing portion 93 formed on the right half of one side of the base plate 91, and a locking portion 95 formed on the left half. An opening 97 (see Figures 5 and 6) is located approximately in the center of the right half of the base plate 91. The gear housing portion 93 is cylindrical with the opening 97 at its center, and along the circumference centered on the opening 97, it has a small diameter cylindrical portion 99, a notch 101, and a large diameter cylindrical portion 103. In detail, along the clockwise direction centered on the opening 97, the small diameter cylindrical portion 99, the notch 101, and the large diameter cylindrical portion 103 are arranged in that order. The large diameter cylindrical portion 103 is positioned so that its downstream end face in the clockwise direction faces downward. The height of the notch 101 (height from one side of the base plate 91) is lower than that of the small diameter cylindrical portion 99 and the large diameter cylindrical portion 103.

[0027] The locking portion 95 is cube-shaped, and a locking pin 105 is erected in the center of its front end surface (front surface), parallel to the axial direction of the gear housing portion 93. The locking pin 105 is reinforced with a cross-shaped rib. A projection 107 is formed on the upper surface of the locking portion 95.

[0028] As shown in Figure 3, the locking member 73 is housed in the upper space 51 of the outer cover 7 with the locking portion 95 on the left and the gear housing portion 93 on the right, and the pin 55 of the outer cover 7 is inserted into the opening 97 of the base plate 91. This allows the locking member 73 to rotate vertically around the pin 55. The vertical rotation of the locking member 73 is restricted by the upper and lower side plates 49 of the upper space 51. As shown in Figure 5, the upper side plate 49 is provided with a plate piece 49a extending downward, and the lower side plate 49 has an inclined surface 49b that is angled diagonally downward and to the left. The locking member 73 rotates between a substantially horizontal position (locked position) where the upper surface of the locking portion 95 abuts against the lower end surface of the plate piece 49a, and a downward-inclined position (released position) where the lower surface of the locking portion 95 abuts against the inclined surface 49b.

[0029] The locking pin 105, erected on the locking portion 95, protrudes forward from the upper space 51. Due to the aforementioned rotation of the locking member 73, the locking pin 105 moves circumferentially around the pin 55. When the locking member 73 rotates to the locked position with the outer cover 7 closed, the locking pin 105 moves upward and engages with the downward-facing engagement recess 3c provided on the front side plate of the device body 3 (see Figure 9). In this way, the locking member 73, supported by the outer cover 7, engages with the engagement recess 3c of the device body 3, fixing the outer cover 7 in a position where it cannot rotate from the closed position. On the other hand, when the locking member 73 rotates to the released position, the locking pin 105 moves downward away from the engagement recess 3c, releasing the engagement of the locking member 73 with the engagement recess 3c, and the outer cover 7 becomes rotatable (see Figure 6).

[0030] Next, the torque limiter 75 will be described. As shown in Figure 4, the torque limiter 75 is a torsion coil spring and has a helical coil portion 111 and first and second arm portions 113 and 115 extending radially from the coil portion 111. The winding direction of the coil portion 111 is clockwise, towards the rear when viewed from the front of the image forming apparatus 1. The first arm portion 113 extends radially from the end of the coil portion 111 on the winding start side, and the second arm portion 115 extends radially from the end of the coil portion 111 on the winding end side. When no load is applied to both arm portions 113 and 115, the inner diameter of the coil portion 111 is slightly smaller than the outer diameter of the small diameter portion 83 of the drive gear 71.

[0031] The coil section 111 is mounted on the small diameter section 83 of the drive gear 71. When a load is applied to both arm sections 113 and 115 so that the coil section 111 expands in diameter (see arrows F1 and F2 in Figure 4), and the load is released after the small diameter section 83 of the drive gear 71 is inserted through the expanded coil section 111, the coil section 111 shrinks in diameter and is mounted on the small diameter section 83. As a result, the torque limiter 75 rotates together with the drive gear 71. On the other hand, when a load is applied to both arm sections 113 and 115 in the opposite direction, the coil section 111 expands in diameter. In this case, even if the drive gear 71 rotates, the torque limiter 75 does not rotate, and the drive gear 71 spins freely relative to the torque limiter 75.

[0032] The drive gear 71, with the torque limiter 75 attached, is housed in the gear housing portion 93 of the locking member 73. The small diameter cylindrical portion 99 of the gear housing portion 93 houses the small diameter portion 83, to which the coil portion 111 of the torque limiter 75 is attached, and the pin 55 inserted into the opening 97 of the base plate 91 is inserted into the shaft hole portion 81. This allows the drive gear 71 to rotate around the pin 55. The large diameter cylindrical portion 103 of the gear housing portion 93 houses the second arm portion 115, and the notch portion 101 houses the first arm portion 113. The gear portion 85 and the large diameter portion 87 of the drive gear 71 protrude forward from the gear housing portion 93.

[0033] Next, the biasing member 77 will be described. As shown in Figure 5, the biasing member 77 is a coil spring and is positioned between the projection 107 formed on the upper surface of the locking portion 95 of the locking member 73 and the side plate 49 above the upper space 51 of the outer cover 7. The biasing member 77 biases the locking portion 95 of the locking member 73 downward. As a result, the locking member 73 rotates to the release position where the locking portion 95 contacts the inclined surface 49b of the side plate 49.

[0034] The operation of the regulatory mechanism 65 having the above configuration will be explained with reference to Figures 5 to 11. Figures 5, 7, 8, 10, and 11 are cross-sectional views of the regulatory mechanism 65, and Figures 6 and 9 are perspective views of the regulatory mechanism 65.

[0035] When the outer cover 7 rotates to the closed position, as described above, the locking mechanism 63 engages the outer cover 7 with the device body 3. Also, the input gear 59 of the outer cover 7 meshes with the transmission gear 33 of the device body 3. As shown in Figures 5 and 6, the locking member 73 of the regulating mechanism 65 is biased by the biasing member 77 to rotate to the released position, and the locking pin 105 of the locking part 95 is separated downward from the engagement recess 3c of the device body 3. Also, as shown in Figure 5, the second arm portion 115 of the torque limiter 75 is located approximately in the center of the circumferential direction of the large diameter cylindrical portion 103, and the first arm portion 113 is housed in the notch portion 101.

[0036] Subsequently, when the image forming operation starts, the motor 31 is driven. The driving force of the motor 31 is transmitted to the input gear 59 via the transmission gear 33, and the drive roller 29A of the transport roller pair 29 rotates via the timing belt 61. This makes it possible to transport the paper along the reverse transport path 27. Furthermore, the driving force is transmitted from the input gear 59 to the drive gear 71. As shown in Figure 7, the drive gear 71 rotates in a clockwise direction. Then, the torque limiter 75 also rotates together with the drive gear 71 (see arrow R1), the second arm portion 115 comes into contact with the end face of the large diameter cylindrical portion 103, and the first arm portion 113 reaches near the end face of the notch portion 101.

[0037] Subsequently, as the drive gear 71 rotates further, as shown in Figure 8, the second arm 105 of the torque limiter 75 pushes up the end face of the large-diameter cylindrical portion 103 (see arrow R1), and the locking member 73 begins to rotate upward against the biasing force of the biasing member 77. When the locking member 73 rotates to a nearly horizontal engagement position, as shown in Figure 9, the locking pin 105 of the locking member 73 engages with the engagement recess 3c of the device body 3, and the outer cover 7 is fixed to the device body 3 in a way that prevents rotation.

[0038] Furthermore, even if the rotation of the locking member 73 is restricted, the drive gear 71 continues to rotate during the image forming operation, so the second arm portion 115 of the torque limiter 75 continues to press against the end face of the large-diameter cylindrical portion 103. As a result, a counterclockwise torque is generated from the second arm portion 115 to the coil portion 111, causing the coil portion 111 to expand in diameter. Consequently, the drive gear 71 rotates freely relative to the torque limiter 75. In this way, the drive gear 71 continues to rotate during the image forming operation, and the fixing between the outer cover 7 and the device body 3 is maintained.

[0039] When the image forming operation is stopped, the motor 31 stops driving and the drive gear 71 stops rotating. Then, as shown in Figure 10, the force applied to the second arm portion 115 of the torque limiter 75 disappears, the coil portion 111 shrinks in diameter and is attached to the small diameter portion 83 of the drive gear 71, and the torque limiter 75 becomes able to rotate together with the drive gear 71.

[0040] Subsequently, the motor 31 is driven to rotate the transmission gear 33 in the opposite direction. As a result, as shown in Figure 11, the drive gear 71 rotates counterclockwise via the input gear 59, and the torque limiter 75 rotates together with the drive gear 71 (see arrow R2). Consequently, the second arm portion 115 moves counterclockwise away from the end face of the large-diameter cylindrical portion 103.

[0041] As shown in Figure 12, the locking portion 95 of the locking member 73 is then biased by the biasing member 77 and rotates to the released position. As a result, as shown in Figure 6, the locking pin 105 moves downward from the engagement recess 3c, the engagement between the outer cover 7 and the device body 3 is released, and the outer cover 7 becomes rotatable to the open position.

[0042] As described above, according to the image forming apparatus 1 of the present invention, the regulating mechanism 65 can restrict the rotation of the outer cover 7 from the closed position to the open position during the image forming operation. Therefore, it is possible to avoid situations in which the outer cover 7 is accidentally opened during the image forming operation, causing a paper jam.

[0043] Furthermore, the drive gear 71, locking member 73, torque limiter 75, and biasing member 77 of the regulating mechanism 65 are housed in the upper space 51 of the outer cover 7, allowing for efficient use of space. In addition, since the drive gear 71 is driven by the input gear 59 for driving the drive roller 29A of the transport roller pair 29, there is no need to provide a dedicated drive transmission mechanism.

[0044] Furthermore, since the locking member 73 is rotated via the second arm portion 115 of the torque limiter 75, the travel distance of the locking pin 105 can be increased. Therefore, the locking member 73 can be reliably rotated between the locked position and the unlocked position.

[0045] Furthermore, the regulating mechanism 65 can be applied to opening and closing members other than the outer cover 7. For example, the regulating mechanism 65 can also be applied to the front cover (not shown) that opens and closes the image forming unit 15.

[0046] Although the present invention has been described in terms of specific embodiments, the present invention is not limited to the above embodiments. Those skilled in the art can modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of Symbols]

[0047] 1. Image forming apparatus 3. Main unit of the device 5. Transport Unit 7. Outer cover (cover) 27 Conveyor path 29 Conveyor roller pair 29A Drive Roller 29B Driven roller 31. Motor (power source) 33 Transmission Gears 59 Input Gear 65 Regulatory bodies 71 Drive gear 73 Locking component 75 Torque Limiter 77 Biasing member

Claims

1. A cover is supported on the main body of the device so as to be openable and closable, A drive source provided in the main body of the apparatus, which generates driving force for performing an image forming operation, A transmission gear provided on the main body of the device, which rotates in one direction by the driving force generated by the drive source, The device includes a restricting mechanism that restricts the opening of the cover while the image forming operation is being performed, The aforementioned iPhone mechanism, A drive gear is rotatably supported by the cover and engages with the transmission gear when the cover is closed, A locking member rotates around the drive gear between a locked position in which it engages with the main body of the device to restrict the opening of the cover and a released position in which it is released from engagement with the main body of the device, A torque limiter is positioned between the locking member and the drive gear, which transmits the rotation of the drive gear to the locking member until a predetermined torque is applied, and causes the drive gear to rotate freely relative to the locking member when a torque exceeding the predetermined amount is applied. An image forming apparatus characterized by comprising a biasing member that biases the locking member to rotate to the released position.

2. While the image forming operation is being performed, the transmission gear rotates in one direction, causing the drive gear to rotate, and the rotation of the drive gear is transmitted to the locking member by the torque limiter, causing the locking member to rotate to the locked position, after which the drive gear spins freely relative to the locking member. The image forming apparatus according to claim 1, characterized in that, after the image forming operation is completed and the rotation of the transmission gear in the one direction stops, the transmission gear rotates in the opposite direction, the torque limiter rotates together with the drive gear and moves away from the locking member, and the locking member is biased by the biasing member and rotates to the release position.

3. The device further comprises a transport unit positioned inside the cover and provided on the main body of the device in a manner that allows it to be opened and closed, The image forming apparatus according to claim 1, characterized in that a paper transport path is formed between the transport unit and the cover.

4. A pair of conveying rollers that convey a sheet along the conveying path includes a drive roller supported by the cover and a driven roller supported by the conveying unit, The system further comprises an input gear rotatably supported by the outer cover, which meshes with the transmission gear when the outer cover is closed to provide driving force to the drive roller, The image forming apparatus according to claim 3, characterized in that the drive gear engages with the transmission gear via the input gear when the cover is closed.

Images