Image forming apparatus

Abstract

To facilitate operations to remove a medium at the occurrence of paper jam, thereby stabilizing conveyance of the medium.SOLUTION: An image forming apparatus 1 has: an apparatus main body 1A that includes an image forming unit 6; a cover 11 that is attached to the apparatus main body 1A and openable and closable between an open position and a closed position; and a removable medium guide 20 that is mounted at a mounting position inside the apparatus main body 1A and guides a medium M. The medium guide 20 has a first post 21 and a second post 22. The cover 11 has a pressing surface 15 that presses the medium guide 20 toward the mounting position when the cover 11 moves from the open position to the closed position. The apparatus main body 1A has leading parts (U-shaped groove 31 and rail part 32) that leads the first post 21 of the medium guide 20 so that the medium guide 20 moves toward the mounting position, and a position regulation part 33 that is in contact with the second post 22 of the medium guide 20 to regulate the position of the medium guide 20.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present disclosure relates to an image forming apparatus that forms an image on a medium.

Background Art

[0002] An image forming apparatus has an openable guide member and is configured to open the guide member to remove a medium when a jam of the medium occurs (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional image forming apparatus, even when the guide member is opened, there is a problem that the space for the user to remove the medium is small and the work is difficult. Further, when the guide member is pushed up by the conveyed medium, there is a possibility of causing poor conveyance of the medium.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to improve workability for removing a medium when a jam occurs and to stabilize conveyance of the medium.

Means for Solving the Problems

[0006] The image forming apparatus disclosed herein includes an apparatus body including an image forming unit, a cover attached to the apparatus body that can be opened and closed between an open position and a closed position, and a removable media guide mounted at a mounting position inside the apparatus body for guiding a medium. The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The media guide has a protruding shaped portion that protrudes toward the side where the cover is positioned and is pressed by the pressing portion of the cover, a first contact portion, and a second contact portion. The apparatus body has a guiding portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, and a position regulating portion that contacts the second contact portion of the media guide to restrict the position of the media guide. The protruding shaped portion contacts the pressing portion of the cover in the open position when the media guide is pulled out from the apparatus body. retention It has a surface. When the holding surface contacts the pressing portion of the cover in the open position, and the first contact portion contacts the guide portion, the cover moves from the open position to the closed position, causing the contact position between the first contact portion and the guide portion to move, and the media guide moves to the mounting position. The image forming apparatus disclosed herein also includes an apparatus body including an image forming unit, a cover attached to the apparatus body that can be opened and closed between an open position and a closed position, and a removable media guide mounted at a mounting position inside the apparatus body for guiding a medium. The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The media guide has a first contact portion, a second contact portion, and a first roller that contacts the medium. The apparatus body includes a guiding portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, a position regulating portion that contacts the second contact portion of the media guide to restrict the position of the media guide, and a second roller that contacts the first roller. The image forming apparatus disclosed herein also includes an apparatus body including an image forming unit, a cover attached to the apparatus body that can be opened and closed between an open position and a closed position, and a removable media guide mounted at a mounting position inside the apparatus body for guiding a medium. The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The media guide has a first contact portion and a second contact portion. The apparatus body has a guiding portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, and a position regulating portion that contacts the second contact portion of the media guide to regulate the position of the media guide. The media guide is arranged in a transport path from a media storage portion containing a medium toward the image forming unit. The image forming apparatus disclosed herein also includes an apparatus body including an image forming unit, a cover attached to the apparatus body that can be opened and closed between an open position and a closed position, and a removable media guide mounted in a mounting position inside the apparatus body for guiding a medium. The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The media guide has a first contact portion, a second contact portion, and a portion that contacts the cover in the open position when the media guide is pulled out from the apparatus body. retention The device body has a surface. The device body has a guide part that guides the first contact part of the media guide so that the media guide moves toward the mounting position, and a position regulating part that contacts the second contact part of the media guide to regulate the position of the media guide. As the cover moves from the open position to the closed position, the second contact portion comes into contact with the position regulating portion, and then the media guide rotates around the second contact portion. [Effects of the Invention]

[0007] According to this disclosure, since the media guide is detachable, a large space can be secured when removing jammed media, improving work efficiency. Furthermore, when the media guide is installed in the mounting position, the media guide is pressed against the cover, the first contact portion is guided to the guide portion, and the second contact portion contacts the position regulating portion, thereby improving the mounting accuracy of the media guide and enabling stable media transport. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing an image forming apparatus according to the first embodiment. [Figure 2] This is a perspective view showing the image forming apparatus of the first embodiment with the cover open. [Figure 3] This is a perspective view showing the image forming apparatus of the first embodiment with the media guide removed. [Figure 4] This is a cross-sectional view showing a portion of the image forming apparatus of the first embodiment, including the cover and media guide. [Figure 5] This is a cross-sectional view showing the image forming apparatus of the first embodiment with the media guide removed. [Figure 6] This is a front view of the media guide according to the first embodiment. [Figure 7] This is a rearward perspective view of the media guide according to the first embodiment. [Figure 8] These are cross-sectional views (A) and (B) showing the medium guide and its surroundings in an image forming apparatus according to the first embodiment. [Figure 9] This is a cross-sectional view showing the medium guide and its surroundings in an image forming apparatus according to the first embodiment. [Figure 10] These are perspective views (A) and (B) showing the medium guide and its surroundings in an image forming apparatus according to the first embodiment. [Figure 11] These are cross-sectional views (A) and (B) showing the state in which the media guide of the image forming apparatus of the first embodiment is being attached. [Figure 12] Figures (A) and (B) show the image forming apparatus of the first embodiment before the media guide is attached and the first stage of the attachment operation. [Figure 13] Figures (A) and (B) show the second and third stages of the mounting operation of the media guide in the image forming apparatus of the first embodiment. [Figure 14] This figure shows the state after the media guide of the image forming apparatus according to the first embodiment has been installed. [Modes for carrying out the invention]

[0009] First embodiment. <Image forming apparatus> First, the image forming apparatus 1 of the first embodiment will be described. FIG. 1 is a diagram showing the image forming apparatus 1. The image forming apparatus 1 is a printer that forms an image using an electrophotographic process.

[0010] The image forming apparatus 1 includes a medium supply unit 5 that supplies a medium M such as printing paper, an image forming unit 6 that forms an image on the medium M, a fixing device 7 that fixes the image on the medium M, and a medium discharge unit 8 that discharges the medium M. These components are housed in a housing 10. The upper part of the housing 10 is covered with a top cover 12.

[0011] The medium supply unit 5 includes a medium cassette 50 as a medium storage unit, a pickup roller 51, a feed roller 52, a retard roller 53, a first conveyance roller 54, a second conveyance roller 56, and a registration roller 58. Pinch rollers 55, 57, and 59, which are driven rollers, are arranged so as to face the first conveyance roller 54, the second conveyance roller 56, and the registration roller 58, respectively.

[0012] The medium cassette 50 houses a medium M such as printing paper. The pickup roller 51 pulls out the medium M from the medium cassette 50 one by one. The feed roller 52 and the retard roller 53 separate the pulled-out medium M one by one and send it out to the conveyance path P1.

[0013] A roller pair consisting of the first conveyance roller 54 (second roller) and the pinch roller 55 (first roller), and a roller pair consisting of the second conveyance roller 56 and the pinch roller 57 convey the medium M along the conveyance path P1. A medium guide 20 for guiding the medium M is provided on the conveyance path P1. Details of the medium guide 20 will be described later.

[0014] A roller pair consisting of the registration roller 58 and the pinch roller 59 corrects the skew (obliquity) of the medium M conveyed along the conveyance path P1 and conveys it to the image forming unit 6 along the conveyance path P2.

[0015] The image forming unit 6 includes a photoreceptor drum 61 as an image carrier, a charging roller 62 as a charging member, a developing roller 65 as a developer carrier, a supply roller 66 as a supply member, and a toner cartridge 67 as a developer container.

[0016] The photoreceptor drum 61 is a cylindrical component in which a photosensitive layer is formed on the surface of a conductive support. The photosensitive layer is a laminate of a charge generation layer and a charge transport layer. The photoreceptor drum 61 rotates counterclockwise in the figure.

[0017] An exposure head 63, which serves as an exposure device, is positioned opposite the photoreceptor drum 61. The exposure head 63 has an LED array, which is an array of LEDs (light-emitting diodes) as light-emitting elements, and a lens array, and irradiates light onto the surface of the photoreceptor drum 61 to form an electrostatic latent image. The exposure head 63 is suspended and supported by the top cover 12.

[0018] The charging roller 62 is positioned to contact the surface of the photoreceptor drum 61 and rotates in accordance with the movement of the photoreceptor drum 61. A charging voltage is applied to the charging roller 62, uniformly charging the surface of the photoreceptor drum 61.

[0019] The developing roller 65 is positioned to contact the surface of the photoreceptor drum 61 and rotates in the opposite direction to the photoreceptor drum 61 (in the direction in which the surface moves at the contact point is forward). The developing roller 65 is subjected to a developing voltage and develops the electrostatic latent image on the surface of the photoreceptor drum 61 with toner.

[0020] The supply roller 66 is positioned to contact the surface of the developing roller 65 and rotates in the same direction as the developing roller 65 (in a direction opposite to the direction of surface movement at the contact point). The supply roller 66 is subjected to a supply voltage and supplies toner to the developing roller 65. The developing roller 65 and the supply roller 66 constitute the developing unit 64.

[0021] The toner cartridge 67 is a removable container that holds toner as a developer. The toner cartridge 67 supplies toner to the developer unit 64. The toner is, for example, black toner, but is not limited to this.

[0022] A transfer roller 68 is positioned as a transfer member so as to contact the surface of the photoreceptor drum 61. A transfer voltage is applied to the transfer roller 68, and it transfers the toner image on the surface of the photoreceptor drum 61 to the medium M that passes between the photoreceptor drum 61 and the transfer roller 68. The medium M that has passed between the photoreceptor drum 61 and the transfer roller 68 is transported to the fuser unit 7 along the transport path P3 by the rotation of the photoreceptor drum 61.

[0023] Although the image forming apparatus 1 is configured to form a monochrome image using the image forming unit 6, it is not limited to this configuration. For example, multiple image forming units for yellow, magenta, cyan, black, etc., may be arranged in the transport direction of the medium M to form a color image.

[0024] The fixing device 7 is located downstream of the image forming unit 6 in the transport direction of the medium M. The fixing device 7 has a fixing roller 71 and a pressure roller 72. The fixing roller 71 has a built-in heater 73 such as a halogen lamp, and the pressure roller 72 is pressed against the fixing roller 71. The fixing roller 71 and the pressure roller 72 heat and pressurize the medium M, fixing the toner image to the medium M.

[0025] The media discharge section 8 has a pair of discharge rollers 81 and a pair of discharge rollers 82 that transport the media M that has passed through the fixing device 7 along the transport path P4 and discharge it from the discharge port 83. The top cover 12 has a stacker section 84 for placing the discharged media M.

[0026] Medium sensors S1, S2, and S3, which detect the passage of medium M, are arranged along the above transport paths P1 to P4. Medium sensors S1 and S2 are located upstream and downstream of the register roller 58, respectively. Medium sensor S3 is located downstream of the fixing device 7.

[0027] The detection signal from the medium sensor S1 is used to determine the rotation start timing of the register roller 58. The detection signal from the medium sensor S2 is used to determine the exposure start timing of the exposure head 63. The detection signal from the medium sensor S3 is used to detect jams in the medium M.

[0028] In Figure 1, the axial direction of the photoreceptor drum 61 is defined as the X direction. The X direction is the axial direction of each roller in the image forming apparatus 1, and is also the width direction of the conveyed medium M. The direction of movement of the medium M as it passes through the image forming section 6 is defined as the Y direction. The direction perpendicular to the X and Y directions is defined as the Z direction. Here, the Z direction is the vertical direction.

[0029] Regarding the Y direction, the transport direction when the medium M passes through the image forming unit 6 is defined as the -Y direction (rearward), and the opposite direction is defined as the +Y direction (forward). Regarding the X direction, when facing the +Y direction, the rightward direction is defined as the +X direction, and the leftward direction is defined as the -X direction. Regarding the Z direction, the upward direction in Figure 1 is defined as the +Z direction, and the downward direction is defined as the -Z direction. Note that these directions do not limit the orientation of the image forming apparatus 1.

[0030] Figures 2 and 3 are perspective views showing the image forming apparatus 1. The housing 10 of the image forming apparatus 1 has a rear frame 10a in the -Y direction (rearward) and side frames 10b on both sides in the X direction. The +Y direction (front) of the housing 10 is covered by a front cover 11, which is an openable and closable cover. In Figures 2 and 3, the front cover 11 is in the open position.

[0031] The front cover 11 is supported by a pivot shaft provided on the side frame 10b, allowing it to rotate between a closed position and an open position around a rotation axis Ax in the X direction. The front cover 11 is closed by rotating in the direction indicated by arrow R1 in Figure 2, and opened by rotating in the direction indicated by arrow R2.

[0032] A locking member 11a is provided near the X-direction end of the front cover 11 for locking the front cover 11 in the closed position. The locking member 11a locks the front cover 11 in the closed position by engaging with an engaging portion 13 provided on the side frame 10b of the housing 10. A release button 11b is provided on the side of the front cover 11, which is operated to release the lock by the locking member 11a.

[0033] When the front cover 11 is opened, the media guide 20 provided in the transport path P1 of the media M is exposed. With the front cover 11 open, the media guide 20 can be removed from the housing 10 as shown in Figure 3. The front cover 11 is held in the open position by contacting a contact portion (not shown) provided on the side frame 10b. The front cover 11 also has a pressing surface 15 (Figure 9) which acts as a pressing portion for pressing the media guide 20, as will be described later.

[0034] In the following description, the housing 10 and its internal components (including the media supply unit 5, the image forming unit 6, and the fixing device 7) of the image forming apparatus 1 will be collectively referred to as the apparatus body 1A. That is, the front cover 11 and the media guide 20 will be described separately from the apparatus body 1A.

[0035] <Media Guide> Figure 4 is an enlarged view of the image forming apparatus 1, including the front cover 11 and the media guide 20, with the front cover 11 in the open position. The shaft 54a of the first conveyor roller 54 (Figure 1) is supported by a bearing 101 provided on the apparatus body 1A. Similarly, the shafts 56a and 57a of the second conveyor roller 56 and pinch roller 57 (Figure 1) are supported by bearings 102 and 103 (Figure 8(A)) provided on the apparatus body 1A.

[0036] A media guide 20, including a pinch roller 55 (Figure 1), is positioned in the +Y direction relative to the bearing section 101. Note that the pinch roller 55 is hidden in Figure 4. The media guide 20 is detachable from the device body 1A, as indicated by the arrow in Figure 4. A guide holder 30, which holds the media guide 20, is positioned adjacent to the bearing section 101. The configuration of the guide holder 30 will be described later.

[0037] Figure 5 shows the state after removing the media guide 20 from Figure 4. By removing the media guide 20, a wider space (indicated by arrow F in Figure 5) is secured in the +Y direction of the first conveyor roller 54 to remove the media M that has jammed in the conveyor path P1.

[0038] Figure 6 is a perspective view of the media guide 20 from the +Y direction (front). Figure 7 is a perspective view of the media guide 20 from the -Y direction (rear). The media guide 20 is a member that is long in the X direction.

[0039] The media guide 20 has a guide surface 25 (Figure 7) that guides the media M along the transport path P1. The guide surface 25 is elongated in the X direction and is a plane parallel to the XZ plane. The media guide 20 has a top plate portion 20a on the +Z side (upper side) of the guide surface 25 and side plate portions 20b on both sides of the guide surface 25 in the X direction.

[0040] Each side plate portion 20b of the media guide 20 is formed with a first post 21 as a first contact portion and a second post 22 as a second contact portion. The second post 22 is located in the -Z direction (downward) and the +Y direction (forward) compared to the first post 21.

[0041] The first post 21 is a cylindrical projection that protrudes in the X direction from the side plate portion 20b. Multiple reinforcing plates 21a are formed at the base of the first post 21. Note that the first post 21 is not limited to a cylindrical shape, and the reinforcing plates 21a may be omitted.

[0042] The second post 22 is a cylindrical projection that protrudes in the X direction from the side plate portion 20b. Furthermore, multiple reinforcing plates 22a are formed at the base of the second post 22. Note that the second post 22 is not limited to a cylindrical shape, and there are cases where the reinforcing plates 22a are not provided.

[0043] On the media guide 20 opposite the guide surface 25, a protruding portion 24 (Figure 6) is formed that protrudes in the +Y direction (forward). The protruding portion 24 is the part that the user grasps when removing the media guide 20 from the device body 1A. The +Y end (front end) of the protruding portion 24 abuts against and is pressed against the pressing surface 15 (Figure 8(B)) of the front cover 11.

[0044] The -Z-direction surface (bottom surface) of the protruding portion 24 is the holding surface 23. The holding surface 23 is the surface that contacts the pressing surface 15 (Figure 11(B)) of the front cover 11 when the media guide 20 is pulled out from the guide holding portion 30.

[0045] The protruding portion 24 is formed in this case at the center of the medium guide 20 in the X direction. Multiple reinforcing ribs 201, which are long in the X direction, are formed on both sides of the protruding portion 24 in the X direction.

[0046] A roller housing section 26 (Figure 7) for housing the pinch roller 55 is formed in the center of the medium guide 20 in the X direction. The roller housing section 26 is open to the guide surface 25. Therefore, the pinch roller 55 can come into contact with the medium M being transported along the transport path P1. The support structure for the pinch roller 55 in the roller housing section 26 will be described later with reference to Figure 9.

[0047] The roller housing section 26 is formed in this case at the center of the media guide 20 in the X direction, but it is not limited to this position. For example, if multiple pinch rollers 55 are arranged in the X direction, multiple roller housing sections 26 may be provided on the media guide 20.

[0048] On the guide surface 25, multiple ribs 202 extending in the Z direction are formed on both sides of the roller housing portion 26 in the X direction. These ribs 202 are arranged in the X direction. The ribs 202 guide the medium M being transported along the transport path P1.

[0049] Figures 8(A) and 8(B) are cross-sectional views of the media guide 20 and its surroundings in the image forming apparatus 1. Figure 8(A) is a cross-sectional view of the media guide 20 at its X-direction end, at the position indicated by arrow 8A in Figure 6. Figure 8(B) is a cross-sectional view of the media guide 20 at its X-direction center, at the position indicated by arrow 8B in Figure 6.

[0050] As shown in Figure 8(A), the first post 21 of the media guide 20 engages with the U-shaped groove 31 of the guide holding part 30 provided on the main body 1A (described later), and the second post 22 abuts against the position regulating part 33 of the guide holding part 30.

[0051] As shown in Figure 8(B), when the media guide 20 is installed inside the main body 1A of the device, the pinch roller 55 included in the media guide 20 is pressed against the first conveyor roller 54, and a nip portion is formed between them.

[0052] The medium M, which is fed out from the medium cassette 50 (Figure 1) by the pickup roller 51 etc. (Figure 1), passes through the nip section between the first transport roller 54 and the pinch roller 55 and is transported along the transport path P1. Above the first transport roller 54 and the pinch roller 55, the second transport roller 56 and the pinch roller 57 are positioned.

[0053] Figure 9 is a cross-sectional view of the media guide 20 and its surroundings in the image forming apparatus 1, at a different location than in Figures 8(A) and (B). The roller housing portion 26 of the media guide 20 has a roller holding portion 27 that holds the shaft portion 55a of the pinch roller 55 so as to be movable in the Y direction. A coil spring 28 is arranged in the roller holding portion 27 as a biasing member that biases the pinch roller 55 toward the first conveying roller 54.

[0054] Furthermore, the roller holding portion 27 is provided with a restricting portion (not shown) that prevents the shaft portion 55a of the pinch roller 55 from falling off.

[0055] Figure 10(A) is a perspective view showing the media guide 20 of the image forming apparatus 1 and its surroundings. Figure 10(B) is a magnified perspective view showing the portion of the media guide 20 including its X-direction end and its surroundings.

[0056] As shown in Figure 10(B), the guide holder 30 has a U-shaped groove 31 which serves as a groove for housing the first post 21. The U-shaped groove 31 is a groove that opens in the +Y direction (i.e., the side on which the front cover 11 is located). The U-shaped groove 31 has an upper edge and a lower edge that both extend in the Y direction, and a curved bottom formed behind them (in the -Y direction).

[0057] The guide holding portion 30 also has a rail portion 32 formed continuously with the U-shaped groove 31. The rail portion 32 extends in the +Y direction (forward) from the lower edge of the U-shaped groove 31. The U-shaped groove 31 and the rail portion 32 constitute a guide portion that guides the first post 21, as will be described later.

[0058] The guide holding portion 30 also has a position regulating portion 33 that abuts against the second post 22 in the -Z direction (downward) relative to the U-shaped groove 31 and the rail portion 32. The position regulating portion 33 is, in this case, a contact surface that extends in the Z direction.

[0059] Figures 11(A) and (B) are cross-sectional views showing the process of attaching the media guide 20 to the main body 1A of the image forming apparatus 1. Figure 11(A) is a cross-sectional view of the media guide 20 at its X-direction end, and Figure 11(B) is a cross-sectional view of the media guide 20 at its X-direction center.

[0060] As shown in Figure 11(A), when the media guide 20 is attached to the main body 1A of the device, first the first post 21 is placed on the rail portion 32. In this state, as shown in Figure 11(B), the holding surface 23 of the media guide 20 comes into contact with the pressing surface 15 of the front cover 11. This ensures that the media guide 20 is held in a stable position and prevents the first post 21 from coming off the rail portion 32.

[0061] When the front cover 11 is rotated from this state toward the closed position, the media guide 20, which is pressed against the pressing surface 15 of the front cover 11, moves in the -Y direction (rearward), and the first post 21 of the media guide 20 moves along the rail portion 32 in the -Y direction and enters the U-shaped groove 31.

[0062] As the first post 21 moves in the -Y direction, the second post 22 also moves in the -Y direction and comes into contact with the position regulating section 33 (Figure 13(A) described later). Subsequently, the media guide 20 rotates around the second post 22, and the first post 21 is completely housed in the U-shaped channel 31.

[0063] As a result, the media guide 20 is mounted in its mounting position within the device body 1A. In this state, as shown in Figure 9, the pressing surface 15 of the front cover 11 presses against the protruding portion 24 of the media guide 20, and the media guide 20 is positioned in the Y direction.

[0064] <Printing operation of image forming apparatus> Next, the printing operation of the image forming apparatus 1 will be explained with reference to Figure 1. When the control unit of the image forming apparatus 1 receives a print command and print data from the host device, it starts the printing operation (image forming operation).

[0065] When the printing operation starts, the pickup roller 51 and feed roller 52 of the media supply unit 5 rotate, feeding the media M on the media cassette 50 one by one to the transport path P1. The first transport roller 54 and the second transport roller 56 also rotate, transporting the media M along the transport path P1. Furthermore, the registration roller 58 starts rotating at a predetermined timing to correct the skew of the media M and transport it along the transport path P2 to the image forming unit 6.

[0066] In the image forming unit 6, the charging voltage, developing voltage, and supply voltage are applied to the charging roller 62, developing roller 65, and supply roller 66, respectively. The photoreceptor drum 61 rotates, and the charging roller 62, developing roller 65, and supply roller 66 rotate in conjunction with it. The charging roller 62 uniformly charges the surface of the photoreceptor drum 61. The exposure head 63 exposes the uniformly charged surface of the photoreceptor drum 61 to form an electrostatic latent image.

[0067] The electrostatic latent image formed on the surface of the photoreceptor drum 61 is developed by the toner adhering to the developing roller 65, and a toner image is formed on the surface of the photoreceptor drum 61. As the rotation of the photoreceptor drum 61 brings the toner image closer to the surface of the transfer roller 68, a transfer voltage is applied to the transfer roller 68.

[0068] As a result, the toner image formed on the photoreceptor drum 61 is transferred to the medium M that passes between the photoreceptor drum 61 and the transfer roller 68. The medium M on which the toner image has been transferred is transported along the transport path P3 to the fuser unit 7 by the rotation of the photoreceptor drum 61.

[0069] In the fixing device 7, the fixing roller 71 and the pressure roller 72 rotate while forming a fixing nip, and the heater 73 is heated to a predetermined fixing temperature. As the medium M passes through the fixing nip between the fixing roller 71 and the pressure roller 72, heat and pressure are applied to the unfixed toner on the medium M, and the toner image is fixed to the medium M.

[0070] The medium M, on which the toner image has been fixed, is transported to the medium discharge unit 8. In the medium discharge unit 8, the medium M is transported along the transport path P4 by discharge roller pairs 81 and 82 and discharged from the discharge port 83. The discharged medium M is stacked on the stacker unit 84. This completes the printing operation.

[0071] <Attaching the media guide> Next, the installation of the media guide 20 onto the main body 1A of the image forming apparatus 1 will be described. Figures 12(A) and (B) show the image forming apparatus 1 before the installation of the media guide 20 and the first stage of the installation operation. In the state shown in Figure 12(A), the front cover 11 is in the open position, and the media guide 20 is not installed on the main body 1A of the apparatus.

[0072] As shown in Figure 12(B), when a user attaches the media guide 20 to the device body 1A, the first post 21 first rests on the rail portion 32 of the guide holding portion 30. In this state, the holding surface 23 of the media guide 20 contacts the pressing surface 15 of the front cover 11, so the media guide 20 is held in a stable state and the first post 21 is prevented from coming off the rail portion 32.

[0073] Figures 13(A) and (B) show the second and third stages of the mounting operation of the media guide 20 in the image forming apparatus 1. The user rotates the front cover 11 towards the closed position from the state shown in Figure 12(B) above.

[0074] Figure 13(A) shows the state where the rotation angle of the front cover 11 has reached 30 degrees, and Figure 13(B) shows the state where the rotation angle of the front cover 11 has reached 60 degrees. Note that the rotation angle of the front cover 11 is the angle from the horizontal plane (i.e., the XY plane).

[0075] As shown in Figure 13(A), when the front cover 11 rotates toward the closed position, the pressing surface 15 of the front cover 11 comes into contact with the protruding portion 24 of the media guide 20, pressing the media guide 20 in the -Y direction as indicated by arrow h. As a result, the first post 21 of the media guide 20 moves along the rail portion 32 in the -Y direction, and the second post 22 of the media guide 20 also moves in the -Y direction.

[0076] As shown in Figure 13(B), when the front cover 11 is rotated 60 degrees from the open position, the second post 22 of the media guide 20 comes into contact with the position restricting section 33. This restricts the movement of the second post 22 in the -Y direction, and subsequent movement of the media guide 20 becomes rotational movement around the second post 22.

[0077] Figure 14 shows the final stage of the mounting operation of the media guide 20 in the image forming apparatus 1. When the user rotates the front cover 11 further toward the closed position from the state shown in Figure 13(B) above, the media guide 20 rotates around the second post 22 as indicated by the arrow r, and as a result the first post 21 enters the U-shaped groove 31 from the rail section 32.

[0078] As shown in Figure 14, when the front cover 11 reaches the closed position (i.e., when the rotation angle of the front cover 11 reaches 90 degrees), the first post 21 is completely housed within the U-shaped groove 31.

[0079] The front cover 11 is locked to the device body 1A by the engagement of the locking member 11a and the engaging portion 13 shown in Figure 2, with its pressing surface 15 pressing against the protruding portion 24 of the media guide 20 in the -Y direction. The pinch roller 55 (Figure 9), held by the media guide 20, is pressed against the first conveyor roller 54 by the biasing force of the coil spring 28 (Figure 9). The pressing surface 15 of the front cover 11 receives the biasing force (reaction force) of the coil spring 28.

[0080] Because the media guide 20 is positioned without any play within the main body 1A of the device, good transport of the media M becomes possible. As a result, the image forming apparatus 1 becomes ready for printing.

[0081] In the above installation procedure, the user only needs to place the first post 21 of the media guide 20 onto the rail section 32 (Figure 12(B)) and rotate the front cover 11 toward the closed position. Therefore, the media guide 20 can be easily installed.

[0082] <Jam release> In the printing operation described above, if a jam occurs in the media M within the image forming apparatus 1, the control unit of the image forming apparatus 1 detects this based on the detection signals from the media sensors S1 to S3 and stops the printing operation. The user then opens the front cover 11 of the image forming apparatus 1 and removes the media M. This operation is called jam removal.

[0083] The user rotates the front cover 11 from the closed position shown in Figure 14 to the open position shown in Figure 12(B), and then pulls the media guide 20 out of the guide holding section 30 in the +Y direction. As a result, the first post 21 of the media guide 20 is pulled out of the U-shaped groove 31 in the +Y direction and held on the rail section 32. The second post 22 is also moved away from the position regulating section 33 in the +Y direction.

[0084] Since the holding surface 23 of the media guide 20 is in contact with the pressing surface 15 of the front cover 11, the media guide 20 is held stably by the front cover 11. The user can remove the media guide 20 from the device body 1A by pulling it up in the +Z direction, as shown in Figure 12(A).

[0085] When the media guide 20 is removed from the main body 1A of the device, a large space is created on the +Y side of the first transport roller 54 (shown as the shaft portion 54a in the figure), allowing the user to reach into this space and remove the media M.

[0086] At positions close to the rotation axis Ax of the front cover 11, simply rotating the media guide 20 makes it difficult to secure enough space to remove the jammed media M. In this embodiment, since the media guide 20 is detachable from the main body 1A of the device, sufficient space can be secured to remove the jammed media M.

[0087] <Effects of the Embodiment> As described above, the image forming apparatus 1 of this embodiment includes an apparatus body 1A including an image forming unit 6, a front cover 11 (cover) attached to the apparatus body 1A and capable of opening and closing between an open position and a closed position, and a removable media guide 20 mounted at a mounting position inside the apparatus body 1A. The media guide 20 has a first post 21 (first contact portion) and a second post 22 (second contact portion). The front cover 11 has a pressing surface 15 (pressing portion) that presses the media guide 20 toward the mounting position when moving from the open position to the closed position. The apparatus body 1A has a guiding portion (U-shaped groove 31 and rail portion 32) that guides the first post 21 of the media guide 20 so that the media guide 20 moves toward the mounting position, and a position regulating portion 33 that contacts the second post 22 of the media guide 20 to position the media guide 20.

[0088] Because of this configuration, opening the front cover 11 allows the media guide 20 to be removed from the main unit 1A of the device. By removing the media guide 20, ample space is provided for the user to remove the media M, making it easier to perform the jam-clearing procedure.

[0089] Furthermore, when the front cover 11 is closed, the first post 21 of the media guide 20 is guided to the guide section (U-shaped groove 31 and rail section 32), and the second post 22 comes into contact with the position regulating section 33. As a result, the media guide 20 is positioned within the device body 1A, enabling stable media transport.

[0090] Furthermore, the guide section described above includes a U-shaped groove 31 having an opening on the side where the front cover 11 is located (+Y direction), and a rail section 32 extending from the opening of the U-shaped groove 31 towards the side where the front cover 11 is located. Therefore, when the media guide 20 is installed, the first post 21 is held on the rail section 32 and moves toward the U-shaped groove 31. This ensures that the media guide 20 is reliably guided to the installation position.

[0091] Furthermore, the second post 22 is positioned further towards the front cover 11 (i.e., in the +Y direction) than the first post 21 in the extending direction of the rail section 32 (i.e., the Y direction). Therefore, as the first post 21 is being housed in the U-shaped groove 31, the second post 22 comes into contact with the position regulating section 33, and thereafter the media guide 20 rotates around the second post 22. This ensures that the media guide 20 is reliably positioned.

[0092] Furthermore, since the first post 21 and the second post 22 are provided at both ends of the media guide 20 in the X direction (i.e., the width direction of the media M), the mounting position accuracy of the media guide 20 can be improved.

[0093] Furthermore, the media guide 20 has a pinch roller 55, and the device body 1A has a first conveyor roller 54. Therefore, when the media guide 20 is removed from the device body 1A, the space between the pinch roller 55 and the first conveyor roller 54 is opened, and the jammed media M can be easily removed.

[0094] Furthermore, since the media guide 20 has a coil spring 28 (biasing member) that biases the pinch roller 55 toward the first conveyor roller 54, the media M can be conveyed stably by the first conveyor roller 54 and the pinch roller 55 when the media guide 20 is mounted on the device body 1A.

[0095] Furthermore, since the front cover 11 has a pressing surface 15 that contacts the media guide 20 pulled out from the main body 1A of the device, the media guide 20 is held in place by the front cover 11 even during attachment and detachment, eliminating concerns about it falling or other damage.

[0096] Furthermore, since the media guide 20 has a protruding portion 24 that extends toward the side where the front cover 11 is located (+Y direction), it is easy to apply pressing force from the front cover 11 to the media guide 20. In addition, the user can grip the protruding portion 24 when attaching or detaching the media guide 20.

[0097] Furthermore, since the media guide 20 is positioned on the transport path P1 from the media cassette 50 containing the media M to the image forming unit 6, a large space can be secured in the image forming apparatus 1 for removing the media M at locations where jams are relatively likely to occur.

[0098] Although preferred embodiments have been described in detail above, this disclosure is not limited to the embodiments described above, and various improvements or modifications can be made. The above embodiments can be combined as appropriate.

[0099] For example, in this case the media guide 20 had a pinch roller 55, but it is not limited to a pinch roller 55; any guide member that guides the conveyed media M is acceptable.

[0100] Furthermore, although the media guide 20 is provided in the feed-side transport path P1 here, it may also be provided in any transport path within the image forming apparatus 1, for example, in the discharge-side transport path P4.

[0101] Although a printer was described here as an example of an image forming apparatus, the image forming apparatus of this embodiment can also be applied to photocopiers, facsimile machines, MFPs (Multifunction Peripherals), and the like. [Explanation of symbols]

[0102] 1 Image forming apparatus, 1A Apparatus body, 10 Housing, 11 Front cover (cover), 15 Pressing surface (pressing part), 20 Media guide, 21 First post (first contact part), 22 Second post (second contact part), 23 Contact surface, 24 Protruding shape part, 25 Guide surface, 28 Coil spring (biasing member), 30 Guide holding part, 31 U-shaped groove (guiding part), 32 Rail part (guiding part), 33 Position regulating part, 50 Media supply part, 51 Pickup roller, 52 Feed roller, 53 Retard roller, 54 First conveying roller (second roller), 55 Pinch roller (first roller), 56 Second conveying roller, 57 Pinch roller, 58 Resist roller, 59 Pinch roller, 60 Image forming unit, 61 Photoreceptor drum (image carrier), 62 Charging roller (charging member), 63 Exposure head (exposure device), 64 Developing unit, 65 Developing roller (developer carrier), 66 Supply roller (supply member), 67 Toner cartridge (developer storage unit), 68 Transfer roller (transfer member), 70 Fixing device, 80 Media discharge unit.

Claims

1. The apparatus includes an image forming unit and A cover attached to the main body of the device, which can be opened and closed between an open position and a closed position, A removable media guide is attached to a mounting position inside the main body of the device and guides the media. It has, The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The aforementioned media guide is A protruding portion that protrudes on the side where the cover is positioned and is pressed by the pressing portion of the cover, The first contact portion and The second contact part and It has, The main body of the aforementioned device is A guide portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, It has a position regulating part that contacts the second contact part of the media guide to regulate the position of the media guide, The protruding portion has a retaining surface that contacts the pressing portion of the cover in the open position when the media guide is pulled out from the main body of the device. When the retaining surface is in contact with the pressing portion of the cover in the open position, and the first contact portion is in contact with the guide portion, as the cover moves from the open position to the closed position, the contact position between the first contact portion and the guide portion moves, and the media guide moves to the mounting position. An image forming apparatus characterized by the following features.

2. The aforementioned induction unit is A groove having an opening on the side where the cover is placed, The groove has a rail portion that extends from the opening to the side where the cover is positioned. The image forming apparatus according to feature 1.

3. The second contact portion is positioned on the side where the cover is located, in the extending direction of the rail portion, compared to the first contact portion. The image forming apparatus according to feature 2.

4. As the first contact portion moves toward the groove, the second contact portion comes into contact with the position regulating portion, and thereafter the media guide rotates around the second contact portion. The image forming apparatus according to feature 2 or 3.

5. The first contact portion and the second contact portion are provided at the respective ends of the media guide in the width direction of the media. The image forming apparatus according to any one of claims 1 to 4.

6. The media guide has a first roller that contacts the media, The device body has a second roller that contacts the first roller. The image forming apparatus according to any one of claims 1 to 5.

7. The media guide has a biasing member that biases the first roller toward the second roller. The image forming apparatus according to feature 6.

8. The retaining surface contacts the pressing portion when the cover moves from the closed position to the open position. The image forming apparatus according to any one of claims 1 to 7.

9. The media guide is positioned in the transport path from the media storage unit containing the media to the image forming unit. The image forming apparatus according to any one of claims 1 to 8.

10. The apparatus includes an image forming unit and A cover attached to the main body of the device, which can be opened and closed between an open position and a closed position, A removable media guide is attached to a mounting position inside the main body of the device and guides the media. It has, The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The aforementioned media guide is The first contact portion and The second contact portion and It has a first roller that contacts the medium, The main body of the aforementioned device is A guide portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, A position regulating unit that contacts the second contact portion of the media guide to regulate the position of the media guide, It has a second roller that contacts the first roller. An image forming apparatus characterized by the following features.

11. The apparatus includes an image forming unit and A cover attached to the main body of the device, which can be opened and closed between an open position and a closed position, A removable media guide is attached to a mounting position inside the main body of the device and guides the media. It has, The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The media guide has a first contact portion and a second contact portion, The main body of the aforementioned device is A guide portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, It has a position regulating part that contacts the second contact part of the media guide to regulate the position of the media guide, The media guide is positioned in the transport path from the media storage unit containing the media to the image forming unit. An image forming apparatus characterized by the following features.

12. The apparatus includes an image forming unit and A cover attached to the main body of the device, which can be opened and closed between an open position and a closed position, A removable media guide is attached to a mounting position inside the main body of the device and guides the media. It has, The cover has a pressing portion that presses the media guide toward the mounting position when the cover moves from the open position to the closed position. The aforementioned media guide is The first contact portion and The second contact portion and With the media guide pulled out from the main body of the device, the retaining surface that contacts the cover in the open position and It has, The main body of the aforementioned device is A guide portion that guides the first contact portion of the media guide so that the media guide moves toward the mounting position, It has a position regulating part that contacts the second contact part of the media guide to regulate the position of the media guide, As the cover moves from the open position to the closed position, the second contact portion contacts the position regulating portion, and thereafter the media guide rotates around the second contact portion. An image forming apparatus characterized by the following features.

Images