Image forming apparatus

Abstract

To provide an image forming apparatus that can reduce cost for the apparatus and reduce the size of the apparatus.SOLUTION: An image forming apparatus 1 comprises a writing device 4 as a detachable component detachably attached from a side face of the body of the image forming apparatus. The writing device 4 is guided, during the attachment to and detachment from the body of the image forming apparatus, by a second manual relay conveyance roller 23b and a third manual relay conveyance roller 23c as sheet conveyance rollers of a manual relay conveyance path 23 as a sheet conveyance path arranged immediately below the writing device 4.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] 2. Description of the Related Art Image forming apparatuses that include detachable parts that can be attached to and detached from the side of the apparatus are known.

[0003] Patent Document 1 describes an image forming apparatus in which a writing device is detachably attached to the side of the apparatus as a detachable part. Summary of the Invention [Problem to be solved by the invention]

[0004] In order to stably attach and detach removable parts such as the writing device, it is common practice to provide a guide member in the image forming apparatus body to guide the attachment and detachment of the removable parts. However, this has the risk of leading to increased costs and larger size of the apparatus due to the increased number of parts. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention is characterized in that, in an image forming apparatus having detachable parts that can be attached and detached from the side of the apparatus, the attachment and detachment of the detachable parts is guided by a sheet conveying roller. Effect of the Invention

[0006] According to the present invention, it is possible to reduce the cost and size of the device. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to the present invention; [Diagram 2] FIG. 2 is a schematic diagram of an image forming apparatus having an image reading device provided on the upper portion. [Diagram 3]FIG. 4 is a schematic configuration diagram of a drive device that rotates and drives three manual-feed relay transport rollers in the manual-feed relay transport path. [Figure 4] 4A and 4B are diagrams illustrating a direction in which a writing device is attached to a main body of an image forming apparatus. [Diagram 5] FIG. 4 is a perspective view showing an upper sheet guide member of the manual-feed relay transport path. [Figure 6] 3A and 3B are diagrams illustrating how a writing device is attached to a main body of an image forming apparatus. [Figure 7] FIG. 7 is a schematic diagram showing a state in which a writing device is further inserted into the main body of the image forming apparatus from the state shown in FIG. 6(b). [Figure 8] FIG. 2 is a schematic diagram showing a state in which the writing device is attached to the main body of the image forming apparatus. [Figure 9] FIG. 2 is a schematic perspective view showing a state in which the writing device is attached to the main body of the image forming apparatus. [Figure 10] FIG. 13 is a perspective view showing an upper sheet guide member of a manual-feed relay transport path in a modified example. [Figure 11] FIG. 13 is a perspective view of a writing device according to the modified example. [Figure 12] FIG. 4A is a diagram showing an example of mounting the writing device when there is no guide protrusion, and FIG. 4B is a diagram showing an example of mounting the writing device when there is a guide protrusion. [Figure 13] FIG. 13 is a schematic perspective view showing a state in which the writing device in the modified example is attached to the main body of the image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The best mode for carrying out the present invention will be described below with reference to the drawings. Note that a person skilled in the art can easily modify and alter the present invention within the scope of the claims to create other embodiments, and these modifications and alterations are included in the scope of the claims. The following description is an example of the best mode for carrying out the present invention, and does not limit the scope of the claims.

[0009] An example of a color image forming apparatus to which the present invention is applied will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of an image forming apparatus according to the present invention, as viewed from the front side. As shown in Fig. 1, the image forming apparatus 1 of this embodiment is a full-color image forming apparatus in which four drum-shaped photoconductors 10Y, 10C, 10M, and 10K are arranged in tandem as latent image carriers. These photoconductors are configured as parts of the imaging units 7Y, 7C, 7M, and 7K that are image forming means. These imaging units 7Y, 7C, 7M, and 7K correspond to the colors yellow, cyan, magenta, and black, respectively, and create images of these colors.

[0010] 1 has an intermediate transfer belt 14 as a surface moving member that is supported and rotated by five support rollers 15a, 15b, 15c, 15d, and 15e. Along a tension line on the lower side of this intermediate transfer belt 14, the image forming units 7Y, 7C, 7M, and 7K are arranged at intervals from the upstream side in the order of the movement direction of the intermediate transfer belt 14 as indicated by the arrow.

[0011] When forming a full-color image, toner images of each color are formed on the photoconductors 10Y, 10C, 10M, and 10K provided in these image forming units 7Y, 7C, 7M, and 7K, as described below. Next, these toner images of different colors are transferred and superimposed one after another onto the intermediate transfer belt 14 as the intermediate transfer belt 14 moves, by the function of primary transfer rollers 16 as transfer means disposed opposite each photoconductor with the intermediate transfer belt 14 in between. More specifically, the location on the intermediate transfer belt 14 where the primary transfer roller 16 is in contact is called the transfer position, and transfer is performed at this transfer position.

[0012] The four superimposed transferred toner images are transferred collectively onto the sheet P at the secondary transfer nip between the support roller 15a and the secondary transfer roller 9, and the sheet passes between the pair of fixing rollers 6a and 6b of the fixing device 6, and is then discharged onto the discharge tray 19 by the discharge rollers 26. In this way, a full-color image is obtained on the sheet.

[0013] In order to accommodate the black image single-color formation mode, the intermediate transfer belt 14 is configured to be in constant contact with the photosensitive element 10K via the primary transfer roller 16, while the intermediate transfer belt 14 is configured to contact and separate from the other photosensitive elements by the function of a movable tension roller.

[0014] At the bottom of the image forming apparatus main body, there are provided a paper feed cassette 5 that stores a plurality of stacked sheets P on which an output image is to be recorded, and a paper feed section 40 that feeds the sheets P from the paper feed cassette 5. The paper feed section 40 includes a pickup roller 41 supported so as to be capable of contacting and releasably contacting the sheets stacked in the paper feed cassette 5, and a separation roller pair 42 that separates the plurality of sheets fed by the pickup roller 41 and feeds only the uppermost sheet. The separation roller pair 42 is composed of a feed roller 42a and a reverse roller 42b. The feed roller 42a is rotated by the driving force of a drive motor to move the sheet in the sheet feeding direction at the separation nip of the separation roller pair 42. On the other hand, the reverse roller 42b is rotated by the driving force of the drive motor transmitted via a torque limiter to move the sheet in the separation nip in the direction returning the sheet to the paper feed cassette (the direction opposite to the sheet feeding direction).

[0015] When one sheet is sandwiched in the separation nip or when no sheet is sandwiched, the rotation load on the reverse roller 42b is relatively large. Therefore, at this time, the torque related to the reverse roller 42b exceeds a specified value, and the torque limiter cuts off the driving force from the motor. Therefore, the reverse roller 42b rotates idly relative to the torque limiter and rotates together with the feed roller 42a.

[0016] On the other hand, when multiple sheets of paper are sandwiched in the separation nip, the rotational load on the reverse roller 42b due to slippage between the sheets is relatively small. Therefore, at this time, the torque on the reverse roller 42b becomes less than a specified value, and the torque limiter transmits the driving force from the motor to the reverse roller 42b. As a result, the reverse roller 42b moves in a direction to return the sheets to the paper feed cassette in the separation nip by the driving force from the motor, and returns the lower sheets, excluding the top sheet, of the multiple sheets sandwiched in the separation nip to the paper feed cassette 5.

[0017] The sheet that has passed through the separation nip is conveyed toward the registration rollers 25 by the relay conveying rollers 24 disposed in the paper feed path 43 .

[0018] A manual feed tray 21 for manual paper feed is provided on the left side of the image forming main body in the figure. A manual feed relay transport path 23 is provided between the writing device 4, which is a removable component and latent image writing means, and the paper feed cassette 5, as a manual feed transport path that transports the sheet P fed from the manual feed tray 21 by the manual feed roller 22 to a junction with the paper feed path 43. Three manual feed relay transport rollers 23a, 23b, and 23c are disposed on the manual feed relay transport path 23. The manual feed relay transport path 23 merges with the paper feed path 43 just before the relay transport roller 24.

[0019] Further, a reversing conveying path 30 for conveying the sheet P again to the secondary transfer nip portion during double-sided printing is provided on the right side of the fixing device 6 of the image forming apparatus main body in the figure. A reversing conveying roller 31 is arranged on the reversing conveying path 30.

[0020] 1, the imaging units 7Y, 7C, 7M, and 7K only differ in the color of toner they handle, and have the same mechanical configuration and imaging process. Therefore, the same reference numerals are used for the components other than the photoconductor, and the configuration and imaging process of any one imaging unit, for example, imaging unit 7Y, will be described.

[0021] Around the photoconductor 10Y of the image-forming unit 7Y, there are arranged, in the clockwise rotational direction in the figure, a charging roller 11 as a charging means for charging the photoconductor 10Y, a position where the light beam L is irradiated, a developing device 12 as a developing means, a primary transfer roller 16, a cleaning device 13, etc.

[0022] The light beam L is emitted from the writing device 4, which is equipped internally with a semiconductor laser as a light source, a coupling lens, an fθ lens, a toroidal lens, a mirror, a rotating polygon mirror, etc. The writing device 4 emits the light beam L for each color toward each photoconductor, and irradiates the light beam L onto a writing position on the photoconductor 10Y to form an electrostatic latent image.

[0023] For example, the developing device 12 of the imaging unit 7Y contains a yellow developer and visualizes the latent image in yellow. The other imaging units contain developers of the respective colors and visualize the latent images in the colors of the developers contained therein.

[0024] During image formation, the photoconductor 10Y rotates and is uniformly charged by the charging roller 11, and is irradiated with a light beam L containing yellow image information at the writing position to form an electrostatic latent image. This latent image is then visualized by yellow toner as it passes through the developing device. The yellow toner image on the photoconductor 10Y is transferred to the intermediate transfer belt 14 by the primary transfer roller 16. This yellow toner image on the intermediate transfer belt 14 is sequentially superimposed and transferred with a cyan toner image by the image creating unit 7C, a magenta toner image by the image creating unit 7M, and a black toner image by the image creating unit 7K, thereby forming a full-color toner image. After the transfer, residual toner is removed from the photoconductor by a cleaning device 13, and then the photoconductor is discharged by a discharge lamp in preparation for the next image formation.

[0025] The sheet P is conveyed from either the paper feed cassette 5 or the manual feed tray 21, and is stopped once it reaches the registration rollers 25. Then, the registration rollers 25 rotate in accordance with a predetermined timing, and send the sheet P toward the nip portion between the support roller 15a and the secondary transfer roller 9.

[0026] The full-color toner image superimposed on the intermediate transfer belt 14 is secondarily transferred to the sheet P at the secondary transfer nip between the support roller 15a and the secondary transfer roller 9. The sheet P to which the full-color toner image has been secondarily transferred is conveyed toward the fixing device 6 and sandwiched in the fixing nip. The toner image on the sheet P is heated and fixed by heat from the fixing roller 6a in the fixing nip. In the case of single-sided printing, the sheet P to which the toner image has been fixed is discharged to the outside of the machine by the paper discharge roller 26. On the other hand, in the case of double-sided printing, after an image is formed on the sheet P as described above, the sheet P is switched back by the paper discharge roller 26 and conveyed to the reversing conveying path 30, and conveyed to the paper feed path 43 in a reversed state, and an image is formed on the back side opposite to the front side on which the image was previously formed as described above, and then discharged to the outside of the machine.

[0027] Furthermore, the image forming apparatus 1 may be provided with an image reading device 2 equipped with a scanner unit 2b and an automatic document feeder (ADF) 2a on the upper portion thereof, as shown in FIG.

[0028] FIG. 3 is a schematic diagram of a drive device 100 that drives and rotates the three manual-feed relay transport rollers 23a, 23b, and 23c of the manual-feed relay transport path 23. As shown in FIG. The driving device 100 includes a motor 101 as a driving source, a plurality of gears 102-104, an electromagnetic clutch 105, and a plurality of timing belts 114-116. The first timing belt 114 is stretched around a pulley 114a fixed to a shaft on which the electromagnetic clutch 105 is attached, and a pulley 114b fixed to a shaft of the third manual-feed relay transport roller 23c.

[0029] The second timing belt 115 is stretched around a pulley 115a fixed to the shaft of the third manual-insertion relay conveyor roller 23c and a pulley 115b fixed to the shaft of the second manual-insertion relay conveyor roller 23b. The third timing belt 116 is stretched around a pulley 116a fixed to the shaft of the second manual-insertion relay conveyor roller 23b and a pulley 116b fixed to the shaft of the first manual-insertion relay conveyor roller 23a.

[0030] The electromagnetic clutch 105 is turned on when feeding a sheet set on the manual feed tray 21, thereby connecting the driving force of the motor 101 to each of the relay conveying rollers 23a to 23c. After the feeding is completed, the electromagnetic clutch 105 is turned off, thereby releasing the driving force connection, so that the driving force of the motor 101 is not transmitted to each of the relay conveying rollers 23a to 23c.

[0031] As shown in Fig. 4, the writing device 4 as a removable part is configured to be removable from an opening on the side that is opened by removing a side cover 1a (see Fig. 1) on the side where the manual feed tray 21 is provided of the image forming apparatus 1. As shown in Fig. 4, the writing device 4 is reciprocated directly above the manual feed relay transport path 23 in approximately the same direction as the sheet transport direction of the manual feed relay transport path 23, thereby being attached to and detached from the main body of the image forming apparatus.

[0032] In this embodiment, the writing device 4 is guided when it is attached to or detached from the main body of the image forming apparatus by the second manual-feed relay conveying roller 23b and the third manual-feed relay conveying roller 23c, which are sheet conveying rollers. The features of this embodiment are described below.

[0033] FIG. 5 is a perspective view showing the upper sheet guide member 123 of the manual-feed relay transport path 23. As shown in FIG. 5, the manual-feed relay conveying rollers 23a to 23c are rotatably supported by the upper sheet guide member 123. Specifically, the shafts of the manual-feed relay conveying rollers 23a to 23c are rotatably supported by the upper sheet guide member 123 on the side opposite to the sheet guiding side of the upper sheet guide member 123. A part of the roller portion of each of the manual-feed relay conveying rollers 23a, 23b, and 23c protrudes from an opening provided in the upper sheet guide member 123 and abuts against a driven roller that rotates along with each of the manual-feed relay conveying rollers 23a, 23b, and 23c.

[0034] Further, a stay member 53 is provided at an upstream end in the sheet conveying direction of the surface opposite to the surface of the upper sheet guide member 123 that guides the sheet, for positioning and supporting the upstream side in the mounting direction of the writing device 4 mounted on the image forming apparatus. The stay member 53 is disposed between the first manual feed relay conveying roller 23a and the second manual feed relay conveying roller 23b. Female screw portions 53a are provided on both sides of the stay member 53 in the sheet width direction (front-rear direction of the image forming apparatus) into which screws 53b (see FIGS. 8 and 9) for fixing the second fixing portion 4b (see FIG. 7) of the writing device 4 are screwed.

[0035] Further, the upper sheet guide member 123 has a unit fixing portion 152 at its downstream end in the sheet conveying direction for fixing the downstream side in the mounting direction of the writing device 4. Fixed springs 52 in the form of leaf springs are provided at both ends in the sheet width direction (front-rear direction of the image forming apparatus) of the unit fixing portion 152 for fixing a first fixed portion 4a (see FIG. 7) provided at the downstream end in the mounting direction of the writing device 4. The fixed springs 52 face a mounting base 152a on which the first fixed portion 4a (see FIG. 7) is placed, with a predetermined gap therebetween.

[0036] The upper sheet guide member 123 also has a fixed guide portion 51 that guides the first fixed portion 4a (see FIG. 7) of the writing device 4 to the unit fixing portion 152. The mounting table 152a is located at a higher position than the manual-feed relay transport rollers 23a, 23b, and 23c. The fixed guide portion 51 has an inclined surface that is positioned upward toward the unit fixing portion 152 (as it moves downstream in the mounting direction of the writing device), and is connected to the mounting table 152a. The inclined surface of the fixed guide portion 51 is formed so as to be connected to the mounting surface of the mounting table 152a.

[0037] FIG. 6 is a diagram illustrating how the writing device 4 is attached to the main body of the image forming apparatus. 6, when mounting the writing device 4 to the main body of the image forming apparatus 1, the writing device 4 is inserted between the upper sheet guide member 123 and the imaging unit 7 while holding the upstream side of the mounting direction of the writing device 4 so that the writing device 4 does not hit the stay member 53. Then, the downstream side of the mounting direction of the lower surface of the writing device 4 abuts against the second manual-feed relay transport roller 23b.

[0038] In this embodiment, as described above, except when a sheet is being fed from the manual feed tray 21, the electromagnetic clutch 105 is in the OFF state, the drive connection with the motor 101 is cut off, and the manual feed relay transport rollers 23a, 23b, and 23c can freely rotate as one group by the second timing belt 115 and the third timing belt. Therefore, when the writing device 4 is further inserted from a state in which the downstream side in the mounting direction of the writing device 4 abuts against the second manual feed relay transport roller 23b, the second manual feed relay transport roller 23b rotates together with the writing device 4, and the writing device 4 can be moved smoothly in the mounting direction while being guided.

[0039] 6(b), when the writing device 4 is being attached, the downstream side of the bottom surface of the writing device 4 in the attachment direction comes into contact with the third manual insertion relay conveyance rollers 23c, which then rotate, and the writing device 4 is attached while being guided by the third manual insertion relay conveyance rollers 23c. Therefore, the writing device 4 can be moved further in the attachment direction smoothly.

[0040] FIG. 7 is a schematic diagram showing a state in which the writing device 4 is further inserted into the main body of the image forming apparatus 1 (downstream side in the mounting direction) from the state shown in FIG. 6(b). 7, a first fixing portion 4a protruding in the mounting direction is provided at the downstream end of the writing device 4 in the mounting direction, and a second fixing portion 4b extending vertically downward is provided at the upstream end of the writing device 4 in the mounting direction. The first fixing portion 4a and the second fixing portion 4b are provided on both sides of the writing device 4 in the sheet width direction (front-rear direction of the image forming device). A through hole is formed in the second fixing portion 4b, through which a screw 53b (see FIGS. 8 and 9) passes.

[0041] As shown in FIG. 7, when the writing device 4 is inserted while being guided by the third manual-insertion relay conveying roller 23c, the first fixed portion 4a abuts against the fixed guide portion 51. As described above, the fixed guide portion 51 has an inclined surface that is positioned upward as it goes downstream in the mounting direction of the writing device 4. Therefore, when the writing device 4 is further mounted in a state in which the first fixed portion 4a abuts against the fixed guide portion 51, the first fixed portion 4a moves upward along the inclined surface by the fixed guide portion 51 and is guided toward the mounting base 152a of the unit fixing portion. As a result, the downstream side of the mounting direction of the writing device 4 is lifted, and the lower surface of the writing device 4 is separated from the third manual-insertion relay conveying roller 23c. Then, as shown in FIG. 8 and FIG. 9, the first fixed portion 4a enters between the mounting base 152a of the unit fixing portion 152 and the fixed spring 52, and the first fixed portion 4a is clamped and fixed between the mounting base 152a and the fixed spring 52.

[0042] When the first fixing portion 4a is clamped between the mounting base 152a and the fixing spring 52 and the writing device cannot be inserted any further, the upstream side of the writing device 4 in the mounting direction is lowered and placed on the stay member 53. Then, as shown in Figures 8 and 9, the second fixing portion 4b is fixed to the stay member 53 with the screw 53b. This positions and fixes the writing device 4 to the main body of the image forming apparatus.

[0043] 8, when the writing device 4 is positioned and fixed to the main body of the image forming apparatus 1, the writing device 4 is separated from the second manual-feed relay conveying roller 23b and the third manual-feed relay conveying roller 23c used as guides. This allows the second manual-feed relay conveying roller 23b and the third manual-feed relay conveying roller 23c to be rotated and driven satisfactorily. As a result, it is possible to suppress the generation of abnormal noise when feeding a sheet from the manual feed tray 21 and the wear of the second manual-feed relay conveying roller 23b and the third manual-feed relay conveying roller 23c.

[0044] In this manner, in this embodiment, the second manual-feed relay transport roller 23b and the third manual-feed relay transport roller 23c, which are functional parts of the image forming apparatus 1, are used as guides. This allows a reduction in the number of parts compared to a case where a separate guide member is provided to guide the writing device 4, and allows for a reduction in the cost and size of the apparatus.

[0045] When removing the writing device 4 from the main body of the image forming apparatus 1, the screw 53b is removed, and the writing device 4 is held on the upstream side in the mounting direction and the side cover 1a (see FIG. 1) on the side where the manual feed tray 21 of the image forming apparatus 1 is provided is removed, and the writing device 4 is pulled out from the opening on the side that has been opened. Then, the first fixed part 4a comes out from between the mounting base 152a and the fixed spring 52, and the first fixed part 4a moves down along the inclined surface while being guided by the fixed guide part 51. Then, the downstream side of the writing device 4 in the mounting direction comes into contact with the third manual feed relay transport roller 23c, which rotates together with the writing device 4 to guide the writing device 4 in the removal direction. Furthermore, as the writing device 4 is pulled out, the downstream side of the writing device 4 in the mounting direction comes into contact with the second manual insertion relay transport rollers 23b, and the writing device 4 is handed over from the third manual insertion relay transport rollers 23c to the second manual insertion relay transport rollers 23b, and is pulled out while being guided by the second manual insertion relay transport rollers 23b. Thereafter, the writing device 4 is pulled out while being lifted up so as not to collide with the stay member 53, and is removed from the main body of the image forming apparatus. In this way, even when removing the writing device 4, the writing device 4 can be easily pulled out from the main body of the image forming apparatus by being guided by the manual insertion relay transport rollers 23b, 23c.

[0046] Next, a modification of this embodiment will be described. FIG. 10 is a perspective view showing an upper sheet guide member 123 of the manual-feed relay transport path 23 in the modified example. In this modification, a guide protrusion 123a serving as a protruding portion is provided between the second manual-feed relay conveying roller 23b and the third manual-feed relay conveying roller 23c on the surface opposite to the sheet guiding surface of the upper sheet guide member 123. The guide protrusion 123a is disposed near the center in the sheet width direction (the front-rear direction of the device) in the vicinity of the third manual-feed relay conveying roller 23c.

[0047] The shape of the guide protrusion 123a is not limited to the shape shown in FIG. 10, and may be a rectangular parallelepiped shape extending in the attachment / detachment direction of the writing device 4 (left-right direction of the image forming device). A plurality of guide protrusions 123a may be provided in the sheet width direction (front-rear direction of the image forming device). By providing a plurality of guide protrusions 123a in the sheet width direction, the writing device 4 can be prevented from tilting in the sheet width direction (front-rear direction of the image forming device), and the posture of the writing device 4 when attached can be stabilized. On the other hand, by providing one guide protrusion 123a, costs can be reduced. When one guide protrusion 123a is provided, it is preferable to provide it near the center in the sheet width direction. Compared to the case where one guide protrusion 123a is provided on the end side in the sheet width direction, when the writing device 4 is guided by the guide protrusion 123a, tilting in the sheet width direction (front-rear direction of the image forming device) can be prevented.

[0048] In this modification, a positioning groove 53c for positioning the writing device 4 in the sheet width direction is provided in the center of the stay member 53 in the sheet width direction (front-rear direction of the image forming apparatus).

[0049] FIG. 11 is a perspective view of the writing device 4 in this modified example, and a positioning protrusion 4c that protrudes vertically downward is provided in the widthwise center of the upstream end of the writing device 4 in the mounting direction.

[0050] As shown in FIG. 12(a), if the guide protrusion 123a is not present, depending on the posture of the writing device 4 when it is inserted into the main body of the image forming apparatus 1, the downstream end portion X1 of the corner portion in the mounting direction of the writing device 4 may abut against the third manual-feed relay conveying roller 23c and damage the surface of the third manual-feed relay conveying roller 23c.

[0051] On the other hand, as shown in FIG. 12(b), by providing the guide protrusion 123a, the downstream side in the mounting direction of the writing device 4 is guided vertically upward by the guide protrusion 123a. As a result, the downstream end X1 in the mounting direction of the corner of the writing device 4 is positioned above the apex of the third manual insertion relay conveyance roller 23c, and the downstream end X1 in the mounting direction of the writing device 4 can be prevented from hitting the third manual insertion relay conveyance roller 23c. Therefore, damage to the surface of the third manual insertion relay conveyance roller 23c can be prevented. In addition, the downstream side in the mounting direction of the writing device 4 can be smoothly caused to ride up onto the third manual insertion relay conveyance roller 23c, and the mounting ease of the writing device 4 to the main body of the image forming apparatus 1 can be improved.

[0052] After the first fixing portion 4a is clamped between the mounting base 152a and the fixing spring 52, the upstream side of the writing device 4 in the mounting direction is lowered and placed on the stay member 53, and as shown in FIG. 13, the positioning protrusion 4c of the writing device 4 fits into the positioning groove 53c of the stay member 53. As a result, the writing device 4 is positioned in the sheet width direction (front-rear direction of the image forming device). By positioning the writing device 4 in the sheet width direction (front-rear direction of the image forming device) in this way, the groove through which the screw 53b at the lower end of the second fixing portion 4b of the writing device 4 penetrates and the female screw portion 53a of the stay member 53 are aligned. This makes it easy to fix the second fixing portion 4b to the stay member 53 with the screw 53b. Then, as in the embodiment, the second fixing portions 4b provided on both sides of the writing device in the width direction are fixed to the stay member 53 with the screw 53b, so that the writing device 4 is positioned and fixed in the left-right direction of the image forming device (mounting and removing direction of the writing device 4). Furthermore, similarly to the embodiment, the second fixing portion 4b is fixed to the stay member 53 by a screw 53b, and the first fixing portion 4a is clamped and fixed between the mounting base 152a and the fixed spring 52, thereby positioning and fixing the writing device 4 in the vertical direction.

[0053] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the spirit of the present invention described in the claims, unless otherwise specifically limited in the above description.

[0054] For example, in the case where the image forming apparatus has a configuration in which the writing device 4, the imaging unit 7, and the intermediate transfer belt are arranged in this order from the top, the intermediate transfer unit including the intermediate transfer belt and the primary transfer roller may be used as the removable part of the present invention. Also, a board such as a control board may be arranged between the writing device 4 and the manual-feed relay transport path 23, and this board may be used as the removable part guided by the second manual-feed relay transport rollers 23b and the third manual-feed relay transport rollers 23c. Furthermore, depending on the layout and configuration of the image forming apparatus, a waste toner bottle, an imaging unit, etc. may be used as a removable part guided by the second manual-feed relay transport rollers 23b and the third manual-feed relay transport rollers 23c.

[0055] In addition, the conveying rollers of the sheet conveying path located directly below the removable part for conveying the sheet in the direction of attaching and detaching the removable part can be used as guides, and are not limited to the second manual feed relay conveying rollers 23b and the third manual feed relay conveying rollers 23c.

[0056] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) In an image forming apparatus 1 having detachable parts such as a writing device 4 that can be attached and detached from the side of the apparatus, the detachable parts are configured so that the attachment and detachment of the detachable parts are guided by sheet conveying rollers (in this embodiment, second manual feed relay conveying roller 23b and third manual feed relay conveying roller 23c). According to this, as described in the embodiment, the removable parts can be stably attached and detached by guiding the removable parts with the sheet conveying rollers. Also, by using the sheet conveying rollers, which are functional parts originally equipped in the image forming apparatus, as a guide, the number of parts can be reduced, and the cost and size of the device can be reduced.

[0057] (Aspect 2) In the first embodiment, the removable part is a writing device 4 that writes a latent image onto a photoreceptor 10 . This allows stable attachment and detachment of attachment and detachment parts of the writing device 4, and also reduces the number of parts, leading to reduced costs and size of the device.

[0058] (Aspect 3) In aspects 1 or 2, a sheet transport path such as a manual feed relay transport path 23 that transports a sheet in the same direction as the attachment / detachment direction of the removable part is provided below a removable part such as the writing device 4, and the removable part is guided to the installation position by sheet transport rollers of the sheet transport path (in this embodiment, the second manual feed relay transport roller 23b and the third manual feed relay transport roller 23c). According to this, as described in the embodiment, the removable parts of the writing device 4 can be stably attached and detached, and the number of parts can be reduced, leading to reduced costs and a smaller device.

[0059] (Aspect 4) In the third aspect, the sheet transport path is a manual feed transport path such as the manual feed relay transport path 23 that transports a sheet fed from the manual feed tray 21. According to this, the sheet conveying rollers of the manual feed conveying path such as the manual feed relay conveying path 23 can be used as guides for the removable parts such as the writing device 4.

[0060] (Aspect 5) In any of the aspects 1 to 4, when a removable part such as the writing device 4 is attached or detached, the sheet conveying roller is allowed to rotate freely. According to this, as described in the embodiment, when the sheet conveying roller guides the removable part, the sheet conveying roller rotates together with the removable part, so that the removable part can be smoothly attached and detached. Also, by the sheet conveying roller rotating together with the removable part, it is possible to prevent the occurrence of scratches on the surface of the sheet conveying roller caused by the attachment and detachment of the removable part.

[0061] (Aspect 6) In any of the first to fourth aspects, when the sheet conveying roller comes into contact with a removable part such as the writing device 4 during installation or removal of the removable part, the sheet conveying roller rotates to convey the removable part in the installation / removal direction of the removable part. According to this, as described in the embodiment, the detachable part can be smoothly attached and detached. In addition, when the detachable part comes into contact with the sheet conveying roller during attachment or detachment, the sheet conveying roller rotates, thereby preventing the occurrence of scratches on the surface of the sheet conveying roller.

[0062] (Aspect 7) In the fifth or sixth embodiment, when a removable part such as the writing device 4 is attached or detached, the driving connection between the sheet conveying roller and a driving source such as the motor 101 that drives the sheet conveying roller is cut off. According to this, when a removable part such as the writing device 4 is attached or detached, the sheet conveying roller can be placed in a freely rotatable state.

[0063] (Aspect 8) In any of the aspects 1 to 7, when a detachable part such as the writing device 4 is attached to the device body, the detachable part is separated from the sheet conveying roller. According to this, when a removable part such as the writing device 4 is attached to the device body and the device is ready for image formation, the removable part is separated from the sheet conveying roller. Therefore, when the sheet conveying roller is rotated to convey a sheet, the sheet conveying roller does not slide against the removable part, suppressing the generation of abnormal noise and wear of the sheet conveying roller.

[0064] (Aspect 9) In aspect 8, there is a fixed guide portion 51 that guides the downstream end of a detachable part such as the writing device 4 in the mounting direction to the image forming device main body toward a fixed portion such as a unit fixing portion 152 that fixes the detachable part, and the fixed guide portion 51 guides the downstream end of the detachable part away from the sheet conveying roller. According to this, as described in the embodiment, the fixed guide portion 51 separates the detachable part from the sheet conveying roller, and the downstream end of the detachable part is fixed to a fixing portion such as the unit fixing portion 152. As a result, when the detachable part is attached to the apparatus main body, the detachable part can be separated from the sheet conveying roller.

[0065] (Aspect 10) In any of aspects 1 to 9, a plurality of sheet conveying rollers are supported at a predetermined interval in the direction of attachment and detachment of a removable part such as the writing device 4, and a sheet guide member such as an upper sheet guide member 123 that guides a sheet is provided, and a protruding shape portion such as a guide protrusion portion 123a that protrudes toward the removable part is provided between the sheet conveying rollers of the sheet guide member. 12, when a removable part such as the writing device 4 is attached to the main body of the image forming apparatus, the downstream side in the attachment direction of the removable part is guided in a direction away from the sheet guide member by the protruding portion such as the guide protrusion 123a, and the downstream end of the corner of the removable part in the attachment direction can be positioned at a position farther away from the sheet guide member than the apex of the sheet conveying roller. This makes it possible to prevent the downstream end of the corner of the removable part in the attachment direction from hitting the sheet conveying roller when the removable part is attached, and to prevent damage to the sheet conveying roller.

[0066] (Aspect 11) In any of aspects 1 to 10, a positioning protrusion 4c is provided at the widthwise center of a detachable part such as the writing device 4 at the upstream end in the mounting direction of the detachable part to the image forming apparatus main body, and a positioning groove 53c with which the positioning protrusion 5c engages is provided at the widthwise center of a stay member 53 supporting the upstream end in the mounting direction of the detachable part. According to this, as explained in the modified example, when the upstream side in the mounting direction of the detachable part is supported by the stay member 53, the positioning protrusion 5c can be fitted into the positioning groove 53c for positioning. [Explanation of symbols]

[0067] 1: Image forming device 1a: Side cover 4: Writing device 4a: First fixed part 4b:Second fixed part 4c: Positioning protrusion 7: Imaging unit 10: Photoreceptor 14: Intermediate transfer belt 21: Manual feed tray 22: Manual feed roller 23: Manual feed relay transport path 23a: First manual feed relay transport roller 23b: Second manual feed relay transport roller 23c: Third manual feed relay transport roller 51: Fixed guide part 52: Fixed spring 53: Stay member 53a: Female thread 53b: Screw 53c: Positioning groove 100: Drive unit 101: Motor 105: Electromagnetic clutch 114: First timing belt 115: Second timing belt 116:Third timing belt 123: Upper sheet guide member 152: Unit fixing part 152a: Placement table L: Light beam P: Seat [Prior art documents] [Patent documents]

[0068] [Patent Document 1] Patent No. 6080625

Claims

1. In an image forming apparatus having a detachable part that is detachable from a side of the apparatus, 13. An image forming apparatus comprising: a sheet conveying roller for guiding the attachment and detachment of the detachable part.

2. 2. The image forming apparatus according to claim 1, 13. An image forming apparatus, wherein the detachable part is a writing device that writes a latent image on a photoconductor.

3. 2. The image forming apparatus according to claim 1, an image forming apparatus having a sheet transport path below the removable component for transporting a sheet in the same direction as the attachment and detachment direction of the removable component, and a sheet transport roller of the sheet transport path for guided the removable component to an installation position.

4. 4. The image forming apparatus according to claim 3, The image forming apparatus according to claim 1, wherein the sheet transport path is a manual feed transport path for transporting a sheet fed from a manual feed tray.

5. 2. The image forming apparatus according to claim 1, When the detachable part is attached or detached, the sheet conveying roller is freely rotatable.

6. 2. The image forming apparatus according to claim 1, an image forming apparatus comprising: a sheet conveying roller that conveys the removable part in a direction in which the removable part is attached or detached; a sheet conveying roller that conveys the removable part in a direction in which the removable part is attached or detached;

7. 7. The image forming apparatus according to claim 5, When the detachable part is attached or detached, the sheet transport roller is disconnected from a drive source that drives the sheet transport roller.

8. 2. The image forming apparatus according to claim 1, 2. An image forming apparatus according to claim 1, wherein the removable part is spaced apart from the sheet transport roller when the removable part is attached to the apparatus body.

9. 9. The image forming apparatus according to claim 8, a fixed guide portion for guiding a downstream end portion of the detachable part in a mounting direction to the image forming apparatus body toward a fixed portion for fixing the detachable part; The image forming apparatus, wherein the fixed guide portion guides the downstream end portion of the detachable part so as to be separated from the sheet conveying roller.

10. 2. The image forming apparatus according to claim 1, a sheet guide member that supports the plurality of sheet conveying rollers at predetermined intervals in the attachment / detachment direction of the detachable part and guides the sheet; The image forming apparatus further comprises a protruding portion protruding toward the detachable component between the sheet conveying rollers of the sheet guide member.

11. 2. The image forming apparatus according to claim 1, a positioning protrusion is provided at a center in a width direction of the detachable part at an upstream end of the detachable part in a mounting direction of the detachable part to the image forming apparatus body, a positioning groove portion with which the positioning protrusion is engaged is provided at a center in the width direction of a stay member that supports an upstream end portion in the mounting direction of the detachable part.

Images