Image forming apparatus

Abstract

To provide an image forming apparatus comprising a cartridge tray that is small-sized and can be reliably electrically connected with process cartridges.SOLUTION: An image forming apparatus comprises a cartridge tray that holds process cartridges and is movable between an inside and outside of the image forming apparatus. The cartridge tray includes tray side plates formed of a metal material. The tray side plates each include a support part on the inside, an outside part on the outside and in an upper part, an inclined plane connecting the support part and the outside part, and a projection part bent to the outside and to a lower part of the support part, and include contacts of the cartridge tray and the process cartridges in an area surrounded by the support part, the inclined plane, and the projection part.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus for forming an image on a recording material. [Background technology]

[0002] Some image forming devices such as printers, copiers, and multifunction devices have a cartridge removably attached to a moving member that moves between the inside and outside of the device body. Patent Document 1 discloses an image forming device in which a cartridge is removably attached to a moving member that moves between the inside and outside of the device body. The moving member in Patent Document 1 is provided with a metallic reinforcing member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-114620 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention is a further development of conventional technology. The present invention relates to an image forming apparatus having a device main body and a tray unit to which a cartridge is removably attached and which has side plates made of metal, and the tray unit is configured to be movable relative to the device main body. An object of the present invention is to arrange, in a space-saving manner, tray contacts of the tray unit that are electrically connected to cartridge contacts of the cartridge. [Means for solving the problem]

[0005] In order to solve the above problems, an image forming apparatus according to the present invention comprises: An image forming apparatus configured to perform an image forming operation using a cartridge, A device body, a tray unit to which the cartridge is removably attached and which is configured to be movable relative to the device body between an internal position located inside the device body and an external position located outside the device body, a first side plate supporting the cartridge, the first side plate being made of metal and including a first support portion and a first outer portion, the first support portion including a first positioning portion configured to abut against the cartridge so that the cartridge is positioned at an image forming position where the image forming operation is performed; a second side plate for supporting the cartridge, the second side plate being formed of metal and including a second support portion and a second outer portion, the second support portion including a second positioning portion configured to abut against the cartridge so that the cartridge is positioned at the image forming position; a tray unit in which a mounting portion into which the cartridge is mounted along a mounting direction is formed between the first side plate and the second side plate, and when viewed in the mounting direction, the first support portion and the second support portion are located between the first outer portion and the second outer portion in a longitudinal direction of the cartridge mounted in the mounting portion; having the tray unit has a tray contact electrically connected to a cartridge contact of the cartridge, the tray contact having an abutment portion that abuts against the cartridge contact, The abutment portion is located between the second support portion and the second outer portion in the longitudinal direction. Effect of the Invention

[0006] According to the present invention, the tray contacts of the tray unit, which are electrically connected to the cartridge contacts of the cartridge, can be arranged in a space-saving manner. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an overall perspective view showing a printer according to a first embodiment of the present disclosure; [Diagram 2] Overall schematic diagram showing the internal structure of the printer [Diagram 3] 1A and 1B are front and rear perspective views of a process cartridge; [Figure 4] FIG. 2 is a front perspective view and a rear perspective view showing a cartridge tray; [Diagram 5] 1A and 1B are front and rear perspective views showing a cartridge tray in a state in which a process cartridge is mounted; [Figure 6] FIG. 1 is a side view showing the drive side of the cartridge tray. [Figure 7] A side view showing the non-drive side of the cartridge tray. [Figure 8] Cartridge Tray Top View [Figure 9] FIG. 1 is a perspective view showing a frame structure of a printer body. [Figure 10] FIG. 2 is a bottom perspective view showing the positioning shaft of the cartridge tray [Figure 11] (a) is a cross-sectional view showing a state in which the positioning shaft on the apparatus main body side is engaged with the positioning groove, (b) is a cross-sectional view showing the positioning shaft and the positioning groove when the cartridge tray is slightly pulled out from the mounted state, (c) is a cross-sectional view showing the positioning shaft and the positioning groove when the cartridge tray is further pulled out from (b), (d) is a cross-sectional view showing a state in which the positioning shaft on the cartridge tray side is engaged with the positioning groove, (e) is a cross-sectional view showing the positioning shaft and the positioning groove when the cartridge tray is slightly pulled out from the mounted state, and (f) is a cross-sectional view showing the positioning shaft and the positioning groove when the cartridge tray is further pulled out from (e). [Figure 12] FIG. 13 is a front view showing ribs provided on the cartridge tray. [Figure 13] AA arrow view of Figure 9 [Figure 14] 4A is a front perspective view showing the process cartridge and the cartridge tray with the front door closed, and FIG. 4B is a front perspective view showing the process cartridge and the cartridge tray with the front door open. [Figure 15]1A is a rear perspective view showing the process cartridge and the cartridge tray with the front door closed, and FIG. 1B is a rear perspective view showing the process cartridge and the cartridge tray with the front door open. [Figure 16] FIG. 2A is a side view showing a process cartridge and a cartridge tray with a front door closed; FIG. 2B is a side view showing a process cartridge and a cartridge tray with a front door open; and FIG. 2C is a side view showing a process cartridge and a cartridge tray with a front door open. [Figure 17] Cartridge tray pulled out [Figure 18] FIG. 13 illustrates the left side of the process cartridge in a pressed state and the contact state of the contacts. [Figure 19] FIG. 13 illustrates the right side of the process cartridge in a pressed state. [Figure 20] FIG. 1 is a diagram showing the positional relationship between a power supply contact portion for a charging roller and a photosensitive drum, etc. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiment may be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, the scope of the present invention is not limited to the following embodiment.

[0009] <<First embodiment>> [Overall configuration] First, a printer 100 as an image forming apparatus according to the first embodiment is an electrophotographic printer. The printer 100 is a full-color laser beam printer. As shown in Fig. 1, the printer 100 has a device main body 100A and a front door 31 that is supported on the device main body 100A so as to be openable and closable. In the description of the printer 100, directions are defined as follows. That is, the side on which the front door 31 of the printer 100 is provided is defined as the front side (or front side), and the opposite side is defined as the rear side (or back side), and the directions from the rear side to the front side and from the front side to the rear side are defined as the front-rear direction.

[0010] In addition, the left side (or non-drive side), right side (or drive side), upper side, and lower side are defined based on the state of the printer 100 as viewed from the front side. The directions from right side to left side and from left side to right side are defined as the left-right direction, and the directions from lower side to upper side and from upper side to lower side are defined as the up-down direction.

[0011] 2, the printer 100 has an image forming unit 10 that forms an image on a sheet S, a sheet feeding section 18, a fixing device 23, a pair of discharge rollers 24, and a control section 200. The printer 100 can form a full-color image or a monochrome image on a sheet-like recording medium (hereinafter referred to as a sheet S) based on an electrical image signal that is output from an external host device 400 and input to the control section 200 via an interface section 300. The external host device 400 is, for example, a personal computer, an image reader, a facsimile machine, etc.

[0012] The control unit 200 is a control means for controlling the electrophotographic image forming process of the printer 100, and transmits and receives various electrical information to and from an external host device 400. It also processes electrical information input from various process devices and sensors, processes command signals to various process devices, controls a predetermined initial sequence, controls a predetermined sequence of the image forming process, and the like.

[0013] The sheet feeding section 18 is provided at the bottom of the printer 100 and includes a cassette 19 that stores sheets S, a middle plate 21 that supports the sheets S so that they can be raised and lowered, a pickup roller 20a, and a separation roller pair 20b. The cassette 19 is configured so that it can be pulled out and attached to the device main body 100A from the front side. The sheets S stacked on the middle plate 21 are fed by the pickup roller 20a and separated one by one by the separation roller pair 20b. The separation roller pair 20b can be of a torque limiter type or a retard roller type, and a separation pad may be used instead of one of the separation roller pair 20b.

[0014] The fixing device 23 has a fixing film 23a heated by a heater and a pressure roller 23b in pressure contact with the fixing film 23a, and the fixing film 23a and the pressure roller 23b form a fixing nip Q. The discharge roller pair 24 has a discharge drive roller 24a and a discharge driven roller 24b which rotates following the discharge drive roller 24a.

[0015] The image forming unit 10 has a cartridge tray 40, four process cartridges (cartridges) PPY, PPM, PPC, and PPK, a scanner unit 11, a transfer unit 12, and a cleaning unit 26. The transfer unit 12 has a drive roller 14, an auxiliary roller 15, a tension roller 16, and an intermediate transfer belt 13. The intermediate transfer belt 13 is stretched across the drive roller 14, the auxiliary roller 15, and the tension roller 16, is made of a dielectric material, and is flexible. The printer 100 is configured to perform an image forming operation using process cartridges PPY, PPM, PPC, and PPK that are detachable from the device main body 100A.

[0016] Primary transfer rollers 17Y, 17M, 17C, and 17K are provided on the inner side of the intermediate transfer belt 13, facing the photosensitive drums of the process cartridges PPY, PPM, PPC, and PPK. The intermediate transfer belt 13 and the secondary transfer roller 27 form a secondary transfer nip T2.

[0017] The four process cartridges PPY, PPM, PPC, and PPK form toner images of four colors, yellow (Y), magenta (M), cyan (C), and black (K), respectively. The four process cartridges PPY, PPM, PPC, and PPK have the same configuration except for the color of the image they form (the color of the toner they contain). Therefore, the configuration and image forming process of one of the four process cartridges PPY, PPM, PPC, and PPK will be described, and the other cartridges will not be described. In addition, when there is no need to distinguish between the process cartridges PPY, PPM, PPC, and PPK, the process cartridges PPY, PPM, PPC, and PPK may be simply called the process cartridge PP.

[0018] As shown in Figs. 2 and 3, the process cartridge PPY is a unit formed by integrating a drum unit OP and a developing unit DP. The drum unit OP has a photosensitive drum 1 as an image carrier, and the developing unit DP has a developing roller 3 that develops a latent image formed on the photosensitive drum 1 into a toner image, and a storage section 3b that stores a developer. A drum coupling (drive transmission member, first drive transmission member) 1c and a developing coupling (drive transmission member, second drive transmission member) 3c are provided on the driving side (right side) in the longitudinal direction of the photosensitive drum 1 and the developing roller 3, respectively. A drive is transmitted from a drive source (not shown) of the apparatus main body 100A to the drum coupling 1c and the developing coupling 3c, and the photosensitive drum 1 and the developing roller 3 rotate.

[0019] Further, a cartridge development contact 2 is provided on the non-driven side (left side) in the longitudinal direction of the developing roller 3. A development bias is applied to the cartridge development contact 2 in a state of contact with a main body development contact 38 (see FIG. 20(b)) described below that is provided in the apparatus main body 100A. An earth member (cartridge contact, cartridge electrode) 1b for connecting the photosensitive drum 1 to a ground potential is provided on the non-driven side in the longitudinal direction of the photosensitive drum 1.

[0020] 3, a drum bearing (driving side support member, first end support member) 1aR is provided at the driving side end (first end) of the process cartridge PPY in the longitudinal direction of the process cartridge PPY. A drum bearing (non-driving side support member, second end support member) 1aL is provided at the non-driving side end (second end) of the process cartridge PPY opposite to the driving side end. The drum bearings 1aR and 1aL support the photosensitive drum 1.

[0021] The longitudinal direction of the process cartridge PPY is the same as the rotational axis direction (longitudinal direction) of the photosensitive drum 1 and the rotational axis direction (longitudinal direction) of the developing roller 3. In the following description of the apparatus main body 100A and the cartridge tray 40, the longitudinal direction of the process cartridge PPY means the longitudinal direction of the process cartridge PPY in a state where it is mounted in a mounting portion 40a described below. In this embodiment, in this case, the longitudinal direction of the process cartridge PPY is a direction perpendicular to the movement direction of the cartridge tray 40 and the mounting direction of the process cartridge PP.

[0022] The process cartridges PPY, PPM, PPC, and PPK as a plurality of cartridges are removably mounted on a cartridge tray (tray unit, moving member, moving unit) 40. As described above, the cartridge tray 40 is configured to be movable relative to the apparatus main body 100A between an internal position located inside the apparatus main body 100A and an external position located outside the apparatus main body 100A while supporting the process cartridges PPY, PPM, PPC, and PPK. In this embodiment, when the cartridge tray 40 is located at the internal position, the process cartridges PPY, PPM, PPC, and PPK are positioned at the image forming position. When the cartridge tray 40 is located at the external position, the process cartridges PPY, PPM, PPC, and PPK are located at the mounting and dismounting positions and can be mounted on and dismounted from the cartridge tray 40.

[0023] The printer 100 includes a front door (opening / closing member) 31 attached to the apparatus main body 100A. The front door 31 is movable between a closed position that covers the cartridge tray 40 located in the internal position and an open position that exposes the cartridge tray 40 located in the internal position. When the user opens the front door 31, the cartridge tray 40 is exposed and the user can access the cartridge tray 40. Then, the user can pull out the cartridge tray 40 to the front side to position each of the process cartridges PPY, PPM, PPC, and PPK in the installation / removal position and replace each of the process cartridges PPY, PPM, PPC, and PPK.

[0024] [Image formation operation] Next, an image forming operation of the printer 100 configured as above will be described. When the control unit 200 of the printer 100 receives a job signal from the interface unit 300, a developing separation mechanism (not shown) provided in the apparatus main body 100A moves in the front-rear direction. The developing roller 3 is brought into contact with the photosensitive drum 1 by the developing separation mechanism.

[0025] In a job for forming a monochrome image, only the photosensitive drum of the process cartridge PPK comes into contact with the developing roller, whereas in a job for forming a full-color image, the photosensitive drums of the process cartridges PPY, PPM, PPC, and PPK come into contact with the respective developing rollers. Each photosensitive drum, each developing roller, and the intermediate transfer belt 13 are driven by a driving source (not shown).

[0026] The scanner unit 11 irradiates the photosensitive drum 1 of the process cartridge PPY with a laser beam corresponding to an image signal. At this time, the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity and potential in advance by a charging member (charging roller) 5, and an electrostatic latent image is formed on the surface by irradiating the laser beam from the scanner unit 11. The electrostatic latent image formed on the photosensitive drum 1 is developed by the developing roller 3, and a yellow (Y) toner image is formed on the photosensitive drum 1.

[0027] The cartridge tray 40 is provided with a light guide 57 (see FIG. 5(b)) as a pre-exposure means. The light guide 57 is made of, for example, transparent acrylic. Before the surface of the photosensitive drum 1 is charged by the charging roller 5, light is emitted from a light source (not shown), and this light is irradiated onto the surface of the photosensitive drum 1 in a state where it is uniformly dispersed in the longitudinal direction by the light guide 57. This stabilizes the potential on the surface of the photosensitive drum 1, making it possible to form a good toner image.

[0028] Similarly, the laser light is irradiated from the scanner unit 11 to the photosensitive drums of the process cartridges PPM, PPC, and PPK, and magenta (M), cyan (C), and black (K) toner images are formed on the photosensitive drums. The toner images of each color formed on the photosensitive drums are transferred to the intermediate transfer belt 13 by a primary transfer bias applied to the primary transfer rollers 17Y, 17M, 17C, and 17K. The full-color toner image transferred to the intermediate transfer belt 13 is transported to the secondary transfer nip T2 by the intermediate transfer belt 13 rotated by the drive roller 14. The image formation process for each color is performed at a timing to overlap the upstream toner image that has been primarily transferred onto the intermediate transfer belt 13.

[0029] In parallel with this image forming process, the sheet S sent out by the sheet feeding section 18 is corrected for skew by a pair of registration rollers 22. The roller pair 22 transports the sheet S toward the secondary transfer roller 27 in accordance with the toner image transported by the intermediate transfer belt 13. The full-color toner image on the intermediate transfer belt 13 is transferred onto the sheet S at the secondary transfer nip T2 by a secondary transfer bias applied to the secondary transfer roller 27. After the toner image is transferred, the toner remaining on the surface of the intermediate transfer belt 13 is removed by a cleaning unit 26 and collected in a waste toner collection container (not shown).

[0030] A predetermined amount of heat and pressure is applied to the sheet S onto which the toner image has been transferred in a fixing nip Q of the fixing device 23, causing the toner to melt and then adhere to the sheet S, thereby fixing the image to the sheet S. The sheet S that has passed through the fixing device 23 is discharged onto a discharge tray 25 by a pair of discharge rollers 24.

[0031] [Cartridge tray] Next, the configuration of the cartridge tray 40 will be described. As shown in Figures 4(a) and (b), the cartridge tray 40 has tray side plates 41L, 41R arranged with a gap therebetween in the left-right direction, connecting members 42, 43, 44, 45, and 46 that connect the tray side plates 41L, 41R, and guide members 47L, 47R. In the following description, the left and right pairs of members are distinguished by adding "L" or "R" to the end of the reference numerals.

[0032] The process cartridges PPY, PPM, PPC, and PPK are supported by tray side plates 41L and 41R. Between the tray side plate (driving side plate, first side plate) 41R and the tray side plate (non-driving side plate, second side plate) 41L, a mounting portion 40a in which the process cartridges PPY, PPM, PPC, and PPK are mounted is formed. The process cartridge PPY is mounted in the mounting portion 40aY, the process cartridge PPM is mounted in the mounting portion 40aM, the process cartridge PPC is mounted in the mounting portion 40aC, and the process cartridge PPK is mounted in the mounting portion 40aK. The process cartridges PPY, PPM, PPC, and PPK are mounted in the mounting portions 40aY, 40aM, 40aC, and 40aK along the mounting direction (the direction of the arrow In).

[0033] The connecting members 42, 43, 44, 45, 46 are made of a resin material and are arranged in order from the front side to the rear side. The connecting members 42, 43, 44, 45 are each provided with the light guide 57 described above. The tray side plates 41L, 41R are made of a metal material. The guide member (driving side cover member, first cover member) 47R is supported by the tray side plate 41R, and the guide member (non-driving side cover member, second cover member) 47L is supported by the tray side plate 41L. The guide member 47R has a guide groove (first guided groove) 47aR, and the guide member 47L has a guide groove (second guided groove) 47aL. The guide grooves 47aL, 47aR extend along the direction in which the multiple cartridges are arranged, and guide the cartridge tray 40 in the pull-out direction and the insert direction relative to the apparatus main body 100A. Moreover, the guide grooves 47aL and 47aR engage with a stopper (not shown) provided on the apparatus main body 100A, thereby restricting the cartridge tray 40 from being pulled out beyond a predetermined position.

[0034] The connecting member 42 has receiving portions 42b, 42b and a gripping portion 42d, and the user can pull out the cartridge tray 40 from the apparatus main body 100A by gripping the gripping portion 42d. When the printer 100 receives a forward impact with the front door 31 closed, the receiving portions 42b, 42b come into contact with the front door 31 to prevent damage to the internal components of the printer 100. Similarly, the connecting member 46 has receiving portions 46a, 46a, and when the printer 100 receives a rearward impact, the receiving portions 46a, 46a come into contact with the fixing stay 35 (see FIG. 6) to prevent damage to the internal components of the printer 100.

[0035] The tray side plates 41L, 41R have a shape in which the upper part is tapered outward compared to the lower part, and the distance in the left-right direction between the tray side plates 41L, 41R is wider at the top and narrower at the bottom. This makes it possible to reduce the left-right width of the cartridge tray 40 without impairing the ease of inserting and removing the process cartridges PPY, PPM, PPC, and PPK, contributing to the miniaturization of the printer 100.

[0036] Furthermore, the tray side plates 41L, 41R are bent at the bottom in an L-shape to ensure strength. Although the tray side plates 41L, 41R and the connecting members 42, 43, 44, 45, 46 are fastened with screws, respectively, this is not limiting and thermal caulking or the like may also be used. Also, it is not necessary to fasten only the connecting members 42, 46 to the tray side plates 41L, 41R, and fasten the connecting members 43, 44, 45 to the tray side plates 41L, 41R.

[0037] 4(a) to 5(b), the tray side plate 41R is provided with cartridge engaging portions (first positioning portions) 41gR, 41hR, 41iR, and 41jR, and each of the cartridge engaging portions 41gR, 41hR, 41iR, and 41jR is formed in a substantially V-shape. Specifically, the cartridge engaging portions 41gR, 41hR, 41iR, and 41jR are formed so that the front side slopes at 65° and the rear side slopes at 45° with respect to the pull-out direction.

[0038] 4(a), the tray side plate 41L is provided with cartridge engaging portions (second positioning portions) 41gL, 41hL, 41iL, and 41jL, and each of the cartridge engaging portions 41gL, 41hL, 41iL, and 41jL is formed in a substantially V-shape. Specifically, the cartridge engaging portions 41gL, 41hL, 41iL, and 41jL are formed so that the front side slopes at 65° and the rear side slopes at 45° with respect to the pull-out direction.

[0039] The process cartridges PPY, PPM, PPC, and PPK are positioned by the cartridge tray 40 at the image forming position where the image forming operation is performed. During the image forming operation, the drum bearing 1aR (see FIG. 3(a)) of the process cartridge PPY abuts against the cartridge engaging portion 41gR, and the drum bearing 1aL (see FIG. 3(b)) of the process cartridge PPY abuts against the cartridge engaging portion 41gL. Similarly, the drum bearing 1aR of the process cartridges PPM, PPC, and PPK abuts against the cartridge engaging portions 41hR, 41iR, and 41jR. Also, the drum bearing 1aL of the process cartridges PPM, PPC, and PPK abuts against the cartridge engaging portions 41hL, 41iL, and 41jL. That is, the cartridge engaging portion 41gR and the cartridge engaging portion 41gL abut against and support the drum bearing 1aR and the drum bearing 1aL of the process cartridge PPY so that the process cartridge PPY is positioned at the image forming position. Similarly, the cartridge engaging portions 41hR, 41iR, 41jR and the cartridge engaging portions 41hL, 41iL, 41jL abut against and support the drum bearings 1aR and 1aL of the process cartridges PPM, PPC, PPK.

[0040] The process cartridges PPY, PPM, PPC, and PPK are positioned relative to the cartridge tray 40 by being pressed downward by their own weight or by pressing units 33, 34 (first pressing member 34, second pressing member 33) (FIGS. 14 to 20). The pressing units 33, 34 press each process cartridge downward during image formation, thereby positioning each process cartridge and the cartridge tray 40 integrated with each process cartridge in the apparatus main body 100A. Although described in detail later, the pressing units 33, 34 are assembled to the apparatus main body 100A so as to be movable between a pressing position where they press each process cartridge and a separating position where they separate in conjunction with the opening and closing operation of the front door 31 of the printer 100.

[0041] In addition, the connecting members 42, 43, 44, 45 are formed with bosses 42aL, 43aL, 44aL, 45aL at the left end, and bosses 42aR, 43aR, 44aR, 45aR at the right end. In addition, the process cartridges of each color are formed with grooves 1dR, 1dL at the left and right ends, as shown in Figs. 3(a) and 3(b). The grooves 1dR, 1dL of the process cartridges PPY, PPM, PPC, PPK engage with the bosses 42aL, 43aL, 44aL, 45aL at the left end, and engage with the bosses 42aR, 43aR, 44aR, 45aR at the right end. This prevents the process cartridges PPY, PPM, PPC, PPK from rotating relative to the cartridge tray 40.

[0042] In this manner, the process cartridges PPY, PPM, PPC, and PPK are mounted on the cartridge tray 40, and each process cartridge is grounded via a wire (drum earth) 48 provided on the guide member 47L.

[0043] [Cartridge Tray Details] The cartridge tray 40 will be described in detail with reference to FIGS. 6(a), 6(b), 7(a), 7(b) and 8. FIG. 6(a) and 6(b) are side views showing the drive side of the cartridge tray 40. 6(a) and 6(b) are views of the cartridge tray 40 seen along the longitudinal direction of the process cartridge PPY, and the guide member 47R is not shown in FIG. 6(b). 7(a) and 7(b) are side views showing the non-drive side of the cartridge tray 40. 7(a) and 7(b) are views of the cartridge tray 40 seen along the longitudinal direction of the process cartridge PPY, and the guide member 47L is not shown in FIG. 7(b). FIG. 8 is a top view of the cartridge tray 40. FIG. 8 is a view of the cartridge tray 40 seen along the mounting direction In of the process cartridges PPY, PPM, PPC, and PPK.

[0044] As shown in FIG. 6(b), the tray side plate 41R includes a first support portion 41R1 having cartridge engaging portions 41gR, 41hR, 41iR, and 41jR, a first outer portion 41R2, and a first connecting portion 41R3 connecting the first support portion 41R1 and the first outer portion 41R2. The tray side plate 41R is made of metal. In this embodiment, the tray side plate 41R is a single metal plate, and includes the first support portion 41R1, the first outer portion 41R2, and the first connecting portion 41R3 integrally. The first support portion 41R1 and the first outer portion 41R2 extend along the moving direction in which the cartridge tray 40 moves relative to the apparatus main body 100A.

[0045] The tray side plate 41R is formed by drawing a metal plate. As a result, the first connection portion 41R3 has a portion located between the first support portion 41R1 and the first outer portion 41R2 in the horizontal direction, and a portion located between the first support portion 41R1 and the first outer portion 41R2 in the vertical direction, as viewed in the longitudinal direction of the process cartridge PPY. Furthermore, the tray side plate 41R is provided with a first opening 41R5. The cartridge engagement portions 41gR, 41hR, 41iR, and 41jR are formed in the first opening 41R5. In the vertical direction, the upper end of the first opening 41R5 is located above the lower end of the first outer portion 41R2, and the lower end of the first opening 41R5 is located below the upper end of the first support portion 41R1 and the first connection portion 41R3. The process cartridges PPY, PPM, PPC, and PPK are exposed to the outside of the mounting portion 40a through the first opening 41R5. More specifically, the drum couplings 1c of the process cartridges PPY, PPM, PPC, and PPK are exposed to the outside of the cartridge tray 40 through the first opening 41R5.

[0046] As shown in FIG. 6(a), the cartridge tray 40 has a guide member (first cover member) 47R attached to the tray side plate 41R outside the mounting portion 40a. The guide member 47R covers the first support portion 41R1. More specifically, the guide member 47R is When viewed in the longitudinal direction of the process cartridge PPY, it covers the first support portion 41R1 so that the cartridge engaging portions 41gR, 41hR, 41iR, and 41jR are exposed.

[0047] As described above, the guide member 47R includes a guide groove (first guided groove) 47aR. With respect to the mounting direction In of the process cartridges PPY, PPM, PPC, and PPK, the guide groove 47aR is located downstream of the cartridge engaging portions 41gR, 41hR, 41iR, and 41jR. The guide groove 47aR extends along the direction in which the process cartridges PPY, PPM, PPC, and PPK are arranged. This allows the cartridge tray 40 to move relative to the apparatus main body 100A along the direction in which the process cartridges PPY, PPM, PPC, and PPK are arranged.

[0048] As shown in FIG. 7(b), the tray side plate 41L includes a second support portion 41L1 having cartridge engaging portions 41gL, 41hL, 41iL, and 41jL, a second outer portion 41L2, and a second connecting portion 41L3 connecting the second support portion 41L1 and the second outer portion 41L2. The tray side plate 41L is made of metal. In this embodiment, the tray side plate 41L is a single metal plate, and integrally includes the second support portion 41L1, the second outer portion 41L2, and the second connecting portion 41L3. The second support portion 41L1 and the second outer portion 41L2 extend along the moving direction in which the cartridge tray 40 moves relative to the apparatus main body 100A.

[0049] The tray side plate 41L is formed by drawing a metal plate. As a result, the second connection portion 41L3 has a portion located between the second support portion 41L1 and the second outer portion 41L2 in the horizontal direction and a portion located between the second support portion 41L1 and the second outer portion 41L2 in the vertical direction when viewed in the longitudinal direction of the process cartridge PPY. Furthermore, the tray side plate 41L is provided with a second opening (contact opening) 41L5. The cartridge engagement portions 41gL, 41hL, 41iL, and 41jL are formed in the second opening 41L5. In the vertical direction, the upper end of the second opening 41L5 is located above the lower end of the second outer portion 41L2, and the lower end of the second opening 41L5 is located below the upper end of the second support portion 41L1 and the second connection portion 41L3. The process cartridges PPY, PPM, PPC, and PPK are exposed to the outside of the mounting portion 40a through the second opening 41L5. More specifically, the ground members 1b of the process cartridges PPY, PPM, PPC, and PPK are exposed to the outside of the mounting portion 40a through the second opening 41L5.

[0050] As shown in FIG. 7(a), the cartridge tray 40 has a guide member (second cover member) 47L attached to the tray side plate 41L outside the mounting portion 40a. The guide member 47L covers the second support portion 41L1. More specifically, the guide member 47L covers the second support portion 41L1 so that at least a part of the second opening 41L5 is covered when viewed in the longitudinal direction of the process cartridge PPY. The guide member 47L is also provided with a wire 48. When viewed in the longitudinal direction of the process cartridge PPY, the wire 48 is disposed at a position overlapping the second opening 41L5.

[0051] As described above, the guide member 47L includes a guide groove (second guided groove) 47aL. With respect to the mounting direction In of the process cartridges PPY, PPM, PPC, and PPK, the guide groove 47aL is located downstream of the cartridge engagement portions 41gL, 41hL, 41iL, and 41jL. The guide groove 47aL extends along the direction in which the process cartridges PPY, PPM, PPC, and PPK are arranged. This allows the cartridge tray 40 to move relative to the apparatus main body 100A along the direction in which the process cartridges PPY, PPM, PPC, and PPK are arranged.

[0052] As shown in FIG. 8, when viewed in the mounting direction In, the process card mounted in the mounting portion 40a In the longitudinal direction (arrow LD) of the cartridge PP, the first support portion 41R1 and the second support portion 41L1 are located between the first outer portion 41R2 and the second outer portion 41L2. When viewed in the mounting direction In, the cartridge engaging portions 41gR, 41hR, 41iR, and 41jR are exposed to the upstream side of the mounting direction In (the front side of the paper) through the first opening 41R5. Similarly, the cartridge engaging portions 41gL, 41hL, 41iL, and 41jL are exposed to the upstream side of the mounting direction In (the front side of the paper) through the second opening 41L5.

[0053] [Cartridge tray positioning configuration] Next, the positioning configuration of the cartridge tray 40 will be described. The apparatus main body 100A (see FIG. 1) has a main body frame 30 having a pair of left and right main body side plates 36L, 36R, and a fixing stay 35 that connects the main body side plates 36L, 36R and divides a process area from a fixing area, as shown in FIG. 9. The process area is an area in which the process cartridges PPY, PPM, PPC, and PPK are accommodated, and the fixing area is an area in which the fixing device 23 is accommodated. The main body side plates 36L, 36R and the fixing stay 35 are made of metal material.

[0054] The main body side plates 36L, 36R have pivotal supports 50aL, 50aR, respectively, at the rear side of the device, and these pivotal supports 50aL, 50aR support the positioning shaft 50. Note that the positioning shaft 50 is fixed immovably to the pivotal supports 50aL, 50aR, but may be supported rotatably so long as it is immovable in the front-rear and up-down directions.

[0055] The main body side plates 36L and 36R have positioning grooves 36aL and 36aR on the front side of the device. As shown in FIG. 10, the front sides of the tray side plates 41L and 41R of the cartridge tray 40 have pivotal support portions 41dL and 41dR, respectively. A positioning shaft 49 is supported by the pivotal support portions 41dL and 41dR. The positioning shaft 49 penetrates the tray side plates 41L and 41R, and a left end portion 49a and a right end portion (not shown) of the positioning shaft 49 protrude to the outside of the tray side plates 41L and 41R. The positioning shaft 49 is fixed to the pivotal support portions 41dL and 41dR so as not to move, but may be supported rotatably as long as it is immovable in the front-rear and up-down directions. The positioning shafts 49 and 50 are formed of round bar-shaped shafts extending in the left-right direction and having a circular cross section, but the shape of the positioning shafts is not limited.

[0056] The connecting member 42 is formed with a shaft contact portion 42c that supports approximately the center portion of the positioning shaft 49 in the axial direction, and the shaft contact portion 42c regulates the downward bending of the positioning shaft 49. Note that the shaft contact portion 42c is not limited to supporting approximately the center portion of the positioning shaft 49 in the axial direction, and may support another position of the positioning shaft 49, but it is preferable to regulate the downward bending of the positioning shaft 49 at the center portion of the positioning shaft 49. Also, the shaft contact portion 42c may be formed to be long in the axial direction.

[0057] As shown in FIG. 11(d), the positioning groove 36aR of the main body side plate 36R is formed along the insertion direction Y1 of the cartridge tray 40, and has an engagement groove 37aR formed on the rear side and a guide groove 37bR formed on the front side.

[0058] The fitting groove 37aR has a width equal to or slightly smaller than the outer diameter of the positioning shaft 49, and fits into the end 49a of the positioning shaft 49 when the cartridge tray 40 is located at the mounting position. The guide groove 37bR has a width greater than the outer diameter of the positioning shaft 49, and guides the end 49a of the positioning shaft 49 into the fitting groove 37aR when the cartridge tray 40 is mounted in the apparatus main body 100A. Note that a guide groove and a fitting groove are also similarly formed in the main body side plate 36L, and guide or engage with the left end of the positioning shaft 49.

[0059] As shown in FIG. 5B, the tray side plates 41L and 41R each have a positioning groove on the rear side. The positioning grooves 41bL and 41bR are formed in the cartridge tray 40, and the positioning grooves 41bL and 41bR engage with the positioning shaft 49 to position the cartridge tray 40. Figures 11(a) to 11(c) are enlarged views showing the positioning groove 41bL. Since the positioning grooves 41bL and 41bR have the same configuration, only the positioning groove 41bR will be described and a description of the positioning groove 41bL will be omitted.

[0060] As shown in Figures 11(a) to 11(c), the positioning groove 41bR has an inclined surface 41f and a positioning surface 41e formed continuously with the inclined surface 41f. The positioning surface 41e extends in a direction substantially perpendicular to the insertion direction Y1 of the cartridge tray 40, and positions the cartridge tray 40 in the insertion direction by abutting against the positioning shaft 50. The inclined surface 41f is inclined downward toward the insertion direction Y1. In addition, a sliding surface 46d (see Figure 5(b)) is formed on the connecting member 46 of the cartridge tray 40, and the sliding surface 46d is formed so as to continue from the inclined surface 41f to the front side.

[0061] As shown in FIG. 11(a), when the cartridge tray 40 is attached, a downward force is applied by the weight of the cartridge tray 40 and the pressing units 33, 34 (see FIG. 14(a)), and thus the inclined surface 41f receives a reaction force F1 from the positioning shaft 50. Because the reaction force F1 has a component force in the insertion direction Y1, the cartridge tray 40 is pulled in the insertion direction Y1 and moves in the direction F2. As a result, the positioning surface 41e is pressed against the positioning shaft 50, and the cartridge tray 40 can be accurately positioned with respect to the apparatus main body 100A. In this way, the inclined surface 41f is formed to generate a component force.

[0062] As shown in Fig. 12, the positioning shaft 50 is journaled by journal portions 50aL, 50aR of the main body side plates 36L, 36R. When the cartridge tray 40 is attached to the apparatus main body 100A, the positioning grooves 41bL, 41bR are located axially inward of the journal portions 50aL, 50aR. For this reason, a downward force is applied to the center portion of the positioning shaft 50 by the weight of the cartridge tray 40 and the pressing units 33, 34 (see Fig. 14(a)), and there is a risk that the positioning shaft 50 will bend downward (in the direction of the outline arrow in the figure).

[0063] Therefore, in this embodiment, the rib 46b is formed at the approximate center in the axial direction (left-right direction) of the connecting member 46. The rib 46b abuts against the approximate center in the axial direction of the positioning shaft 50 to support it, thereby restricting the downward bending of the positioning shaft 50. The rib 46b may support other positions of the positioning shaft 50, not limited to the approximate center in the axial direction of the positioning shaft 50, but it is preferable to restrict the downward bending of the positioning shaft 50 at the center of the positioning shaft 50. The rib 46b may be formed long in the axial direction, or a plurality of ribs 46b may be provided in the axial direction. In this embodiment, the positioning shaft 50 receives a force in the gravitational direction to restrict the downward bending of the positioning shaft 50, but it is not necessary to contact the lower part of the positioning shaft 50 if the bending of the positioning shaft 50 is restricted by receiving a force in the bending direction of the positioning shaft 50.

[0064] 12 and 13, the connecting member 46 is formed with locking portions 46c, 46c that can be locked to the fixing stay 35. The locking portions 46c, 46c can restrict downward bending of the cartridge tray 40 including the connecting member 46 by locking to the fixing stay 35. By suppressing downward bending of the cartridge tray 40, deformation of the positioning grooves 41bL, 41bR of the cartridge tray 40 is also suppressed, and the cartridge tray 40 can be accurately positioned with respect to the positioning shaft 50. Note that only one or three or more locking portions 46c, 46c may be provided as long as they do not interfere with the mounting operation of the cartridge tray 40. Also, one locking portion 46c may be formed long in the axial direction (left-right direction).

[0065] [Cartridge tray pull-out and installation operations] Next, a description will be given of the pulling out and mounting operations of the cartridge tray 40. When the developer in each of the process cartridges PPY, PPM, PPC, and PPK is consumed to such an extent that it is no longer possible to form images of a quality that satisfies the user who purchased the cartridge, the commercial value of the process cartridge is lost.

[0066] Therefore, for example, a means (not shown) for detecting the developer remaining amount in each process cartridge may be provided, and the control unit 200 may compare the detected remaining amount value with a preset threshold value for cartridge life notice or life warning. Then, for a process cartridge whose detected remaining amount value is less than the threshold value, a life notice or life warning for that process cartridge is displayed on a display unit (not shown), and the user is prompted to replace the process cartridge. The user then opens the front door 31 of the printer 100, pulls out the cartridge tray 40 to the outside of the device, and replaces each of the process cartridges PPY, PPM, PPC, and PPK. The operations of pulling out and mounting the cartridge tray 40 will be described in detail below.

[0067] As shown in Figures 14(a) to 15(b), the front door 31 is supported so as to be openable and closable relative to the device main body 100A, and can be held in the open state by door links 32L, 32R connected between the front door 31 and the device main body 100A.

[0068] When the front door 31 is opened by a user, a plurality of link members (not shown) are linked via the door links 32L and 32R, and the transfer unit 12 rotates about 1° around the drive roller 14. As a result, the photosensitive drum 1 of each process cartridge is separated from the intermediate transfer belt 13, as shown in FIG. 16(c).

[0069] Next, as shown in FIG. 20(b), the main body development contact 38 provided on the left side (non-drive side) of the main body 100A of the apparatus is retracted from the cartridge development contact 2 (see FIG. 3(b)) electrically connected to each developing roller 3, and the pressing of the pressing units 33, 34 is released. That is, the pressing unit 33 as the second pressing member moves from the second pressing position to the second separated position, and the pressing unit 34 as the first pressing member moves from the first pressing position to the first separated position. Next, the engagement of the drum coupling 1c and the developing coupling 3c (FIG. 3(a)) on the drive side of each process cartridge is released, and as shown in FIG. 14(b) and FIG. 16(b), the pressing of the cartridge tray 40 by the tray pressing unit 51 is released. As a result, the cartridge tray 40 is in a state where it can be taken out of the main body 100A of the apparatus.

[0070] Here, the tray pressing units 51 are provided on the holders 52L, 52R supported by the main body side plates 36L, 36R, respectively, and press the cartridge tray 40 from the rear side to the front side during image formation. As shown in Figures 16(a) and 16(b), the tray pressing unit 51 has a tray pressing lever 53, a tray pressing link 54, and a biasing spring (not shown).

[0071] 16(a), when the front door 31 is closed, the tray pressing lever 53 is pressed by a tray pressing link 54 that is biased by a biasing spring. As a result, the tray pressing lever 53 presses the pressed portion 41c formed on the tray side plate 41R of the cartridge tray 40 rearward.

[0072] When the front door 31 is opened, as shown in Fig. 16(b), the tray pressing lever 53 is retracted downward by the door links 32L, 32R and a link member (not shown). This releases the tray pressing lever 53 from pressing the cartridge tray 40 rearward, making it possible to remove the cartridge tray 40 from the apparatus main body 100A.

[0073] Next, the movement around the positioning shafts 49, 50 will be described with reference to Figures 11(a) to 11(f). However, since the positioning configuration of the cartridge tray 40 on the positioning shafts 49, 50 is the same on the left and right, only the right side of the device will be described and the description of the left side of the device will be omitted. As shown in Figures 11(a) to 11(f), when the cartridge tray 40 starts to be pulled out, the inclined surface 41f slides on the positioning shaft 50, so that the rear side of the cartridge tray 40 is slightly lifted. Then, the sliding surface 46d provided on the connecting member 46 of the cartridge tray 40 slides on the positioning shaft 50, and the cartridge tray 40 moves in the pulling direction Y2.

[0074] At the same time, the end 49a of the positioning shaft 49 of the cartridge tray 40 comes out of the fitting groove 37aR of the positioning groove 36aR and is handed over to the guide groove 37bR. The cartridge tray 40 is pulled out in the pulling direction Y2 while the end 49a of the positioning shaft 49 is guided by the guide groove 37bR. Figures 11(a) and (d) show a state in which the cartridge tray 40 is located at the mounting position. Figures 11(b) and (e) show a state in which the cartridge tray 40 is pulled out about 3 mm from the mounting position. Figures 11(c) and (f) show a state in which the cartridge tray 40 is pulled out about 10 mm from the mounting position.

[0075] When the cartridge tray 40 is pulled out to a certain extent, the cartridge tray 40 is guided by rollers 56L, 56R (first and second rotating bodies) as shown in Fig. 14(b) and Fig. 15(b). Then, the cartridge tray 40 is pulled out to the outside of the apparatus main body 100A. During image formation, the cartridge tray 40 and the rollers 56L, 56R are not in contact with each other, and a clearance of about 0.5 mm is maintained.

[0076] FIG. 17 is a diagram showing the process of the cartridge tray being pulled out. The guide groove 47aL of the cartridge tray 40 is guided by the guide portion 32aL provided on the door link 32L. The guide groove 47aL of the cartridge tray 40 is guided by the guide portion 32aL provided on the door link 32L. The configuration of the guide groove 47aR and the guide portion 32aR is the same as the configuration of the guide groove 47aL and the guide portion 32aL. Therefore, even when the cartridge tray 40 is pulled out by a large amount, the inclination of the cartridge tray 40 can be reduced and the cartridge tray 40 can be pulled out smoothly. In addition, since the posture of the cartridge tray 40 when pulled out can be stabilized, the replaceability of the process cartridge can be improved.

[0077] The guide grooves 47aL, 47aR are provided on the outside of the first support portion 41R1 and the second support portion 41L1 of the tray side plates 41L, 41R made of a metal material, and are formed in a U-shape with the outside open. Under the guide grooves 47aL, 47aR, protruding portions 41L4, 41R4 extending outward from the first support portion 41R1 and the second support portion 41L1 are arranged. The guide grooves 47aL, 47aR are arranged between the outer portions 41L2, 41R2 and the protruding portions 41L4, 41R4. In the mounting direction of the process cartridge to the cartridge tray 40, the guide groove 47aL is arranged downstream of the cartridge engaging portions 41gL, 41hL, 41iL, 41jL, and the guide groove 47aR is arranged downstream of the cartridge engaging portions 41gR, 41hR, 41iR, 41jR. This provides a strong guide. When the cartridge tray 40 is pulled out, the protrusions 41L4 and 41R4 are supported by the rollers 56L and 56R.

[0078] Also, the guide grooves 47aL, 47aR are provided inside the first outer portion 41R2 and the second outer portion 41L2 in the longitudinal direction of the photosensitive drum 1, and can be arranged without increasing the size of the cartridge tray 40 and the image forming apparatus. The process cartridge can be attached to the cartridge tray 40 by dropping it into the opening that widens upward. The tray side plates 41L, 41R are provided with first support portions 41R1, 41L1 connecting the first outer portion 41R2, the second outer portion 41L2, and the first outer portion 41R3. The cartridge mounting portion 40a includes a connecting portion 41R3 and a second connecting portion 41L3. The first connecting portion 41R3 and the second connecting portion 41L3 have a slope that slopes from the outside to the inside of the mounting portion 40a in the longitudinal direction LD. More specifically, the slopes of the first connecting portion 41R3 and the second connecting portion 41L3 slope from the outside to the inside of the mounting portion 40a from the upstream side to the downstream side in the mounting direction of the process cartridge PP. This slope allows the process cartridge PP to be mounted in the cartridge tray 40 smoothly.

[0079] The mounted process cartridge PP is positioned at the cartridge engaging portions 41gL, 41hL, 41iL, 41jL, 41gR, 41hR, 41iR, 41jR of the tray side plates 41L and 41R. At this time, the wire 48, which is a contact member provided on the cartridge tray 40 for each process cartridge PP, is connected to the ground member 1b, which is a cartridge contact provided at the end of the photosensitive drum 1. The wire 48, as a tray contact, plays the role of an intermediate contact that electrically connects the photosensitive drum 1 to the main body frame 30 of the apparatus main body 100A. Each wire 48 is connected to a conductive line 59 below the cartridge engaging portions 41gL, 41hL, 41iL, 41jL, and is connected to the main body side plate 36L of the main body frame 30 via the conductive line 59. That is, when the cartridge tray 40 is located at an internal position of the apparatus main body 100A, the ground member 1b is electrically connected to the apparatus main body 100A via the wire 48 and the side plate 41L.

[0080] The wire 48 has an arm 48b as a spring part having spring properties, and a wound part 48a wound around the contact part with the ground member 1b along the insertion direction In of the process cartridge PP. The spring properties of the arm 48b urge the wound part 48a toward the ground member 1b. The ground member 1b and the wound part 48a contact each other at a position upstream of the cartridge engagement parts 41gL, 41hL, 41iL, and 41jL and downstream of the second outer part 41L2 in the mounting direction of the process cartridge to the cartridge tray 40. On the other hand, the wound part 48a is roughly positioned by a contact regulating part 47eL provided on the guide member 47L being inserted into and passing through the wound part 48a. The contact regulating part 47eL regulates the contact position between the ground member 1b and the wound part 48a to a predetermined position even when the process cartridge is not mounted in the mounting part 40a. Furthermore, by arranging the wire 48 below the second connection portion 41L3, it is possible to prevent the wire 48 from being damaged when the process cartridge PP is inserted into the cartridge tray 40, and to smoothly insert the process cartridge PP. Also, by arranging the wire 48 inside the second outer portion 41L2 in the longitudinal direction of the photosensitive drum 1, it is possible to arrange the cartridge tray 40 and the image forming apparatus without increasing their sizes.

[0081] The wire 48 is disposed adjacent to the outer side of the second support portion 41L1 of the tray side plate 41L in the longitudinal direction of the photosensitive drum 1, and is held by a guide member 47L having a guide groove 47aL provided on the outer side. The wire 48 is also electrically connected to the tray side plate 41L made of a metal material, and as described later, the tray side plate 41L is connected to the positioning shafts 49 and 50, and the positioning shafts 49 and 50 are connected to the main body frame 30. In this manner, a stronger earth contact path is formed.

[0082] When the cartridge tray 40 is pulled out and the process cartridge is replaced, the cartridge tray 40 is attached to the apparatus main body 100A. The attachment operation when attaching the cartridge tray 40 to the apparatus main body 100A is the opposite of the pull-out operation. At this time, the sliding surface 46d first starts to slide on the positioning shaft 50, and after the positioning shaft 50 passes the sliding surface 46d, the end 49a of the positioning shaft 49 is transferred from the guide groove 37bR to the fitting groove 37aR as shown in Figures 11(b) and (e).

[0083] The boundary between the guide groove 37bR and the fitting groove 37aR is inclined upward, and the end 49a of the positioning shaft 49 is fitted into the fitting groove 37aR, so that the cartridge tray 40 is The user's operating force when mounting the cartridge tray 40 becomes large. However, since the positioning shaft 49 enters the fitting groove 37aR after the sliding surface 46d passes the positioning shaft 50, the timing when the user's operating force becomes large is not concentrated, and the operating force can be reduced. When the cartridge tray 40 is inserted a predetermined distance to the mounting position, the cartridge tray 40 is automatically retracted to the mounting position by a retracting device described later.

[0084] When the cartridge tray 40 is inserted to the mounting position and the front door 31 (opening / closing member) is closed, the tray pressing unit 51 presses the cartridge tray 40 toward the rear as shown in Figures 14(a), 15(a) and 16(a). Then, the drum coupling 1c and the developing coupling 3c (see Figure 3(a)) on the drive side of each process cartridge PP engage with each other, and the pressing units 33 and 34 press each process cartridge PP from above.

[0085] 18 and 19 are diagrams showing a pressing state in which the pressing units 33 and 34 press the process cartridge. FIG. 18(a) is a schematic perspective view showing a contact between the main body development contact 38 and the cartridge development contact 2 connected to the development roller 3, and a contact between the pressing portion 33a and the memory member 7, partially cut in the longitudinal direction of the photosensitive drum 1 on the left side of the process cartridge PPK. FIG. 18(b) is a schematic view showing the cut surface of FIG. 18(a) seen in the moving direction of the cartridge tray 40. FIG. 18(c) is a schematic view showing the cut surfaces of the process cartridges and the cartridge tray 40 in the second imaginary plane IFL shown in FIG. 18(b) seen in the longitudinal direction of the photosensitive drum 1. FIG. 19(a) is a schematic perspective view showing the center of the drum coupling 1c partially cut in the longitudinal direction of the photosensitive drum 1 on the right side of the process cartridge PPK. FIG. 19(b) is a schematic view showing the cut surface of FIG. 19(a) seen in the moving direction of the cartridge tray 40. FIG. 19C is a schematic diagram of a cross section of the process cartridges and the cartridge tray 40 in the first imaginary plane IFR shown in FIG. 19B, viewed in the longitudinal direction of the photosensitive drum 1. FIG.

[0086] Here, the pressing units 33 and 34 press the drum bearings 1aL and 1aR toward the cartridge engaging portions 41gL, 41hL, 41iL, 41jL, 41gR, 41hR, 41iR, and 41jR. The pressing unit 34 (first pressing member) is disposed so as to intersect with a first imaginary plane IFR that intersects with the cartridge engaging portions 41gR, 41hR, 41iR, and 41jR (first positioning portion) perpendicular to the longitudinal direction of the photosensitive drum 1. The pressing unit 33 (second pressing member) is disposed so as to intersect with a second imaginary plane IFL that intersects with the cartridge engaging portions 41gL, 41hL, 41iL, and 41jL (second positioning portion) perpendicular to the longitudinal direction.

[0087] Further, when viewed from the longitudinal direction of the photosensitive drum 1, the cartridge engaging parts 41gL, 41hL, 41iL, 41jL, 41gR, 41hR, 41iR, 41jR are arranged so that a part of the contact part (pressing part) 39, which is a part of the pressing unit 33, 34 that contacts the cartridge, overlaps with the cartridge engaging parts 41gL, 41hL, 41iL, 41jL, 41gR, 41hR, 41iR, 41jR in the pressing direction of the pressing units 33, 34. That is, the force with which the pressing units 33, 34 press the process cartridge is received by the cartridge engaging parts 41gL, 41hL, 41iL, 41jL, 41gR, 41hR, 41iR, 41jR, which are on the straight line. Therefore, the process cartridge can be stably and firmly held and positioned.

[0088] Furthermore, the support portions 41dL, 41dR and the positioning grooves 41bL, 41bR of the tray side plates 41L, 41R are provided on the same plane as the cartridge engaging portions 41gL, 41hL, 41iL, 41jL, 41gR, 41hR, 41iR, 41jR, and are supported by the positioning shafts 49, 50 (FIGS. 6 and 7). The pressing portion 33a, which is a part of the contact portion 39 of the pressing unit 33, also has a contact point with the memory member 7 provided in the process cartridge PP for storing various information such as the operation history of the process cartridge and performance information specific to the process cartridge. As described above, the process cartridge is stably and firmly held. By being able to position it properly, stable power supply and communication can be maintained.

[0089] Further, as shown in FIG. 20, the pressing unit 33 is provided with a main body charging contact 37 for supplying power to the charging roller 5. The process cartridge PP is provided with a charging contact 6 electrically connected to the charging roller 5. The main body charging contact 37 is made of a wire having a configuration similar to that of the wire 48 described above, and is configured to be biased against the charging contact 6 by its spring property and to come into contact with the charging contact 6. FIG. 20 is a diagram showing the positional relationship between the power supply contact portion to the charging roller 5 and the photosensitive drum 1, the charging roller 5, etc. FIG. 20(a) is a schematic perspective view showing the contact between the main body charging contact 37 and the charging contact 6 on the left side of the process cartridge PPK, partially cut in the longitudinal direction of the photosensitive drum 1. FIG. 20(b) is a schematic view of the cut surface of FIG. 20(a) seen in the moving direction of the cartridge tray 40. The pressing unit 33 presses the process cartridge PP from above, even at the portion where the main body charging contact 37 is provided. The pressing unit 33 presses the process cartridge PP from above and positions the main body charging contact 37 relative to the charging contact 6 of the process cartridge, so that the main body charging contact 37 is connected to the charging contact 6. The main body charging contact 37 is disposed at a position overlapping the photosensitive drum 1 and the charging roller 5 in the longitudinal direction of the photosensitive drum 1. That is, the contact position between the main body charging contact 37 and the charging contact 6 is disposed at a position overlapping the photosensitive drum 1 and the charging roller 5 in the longitudinal direction of the photosensitive drum 1. Therefore, the pressing of the main body charging contact 37 and the charging contact 6 around the contact portion of the charging contact 6 by the pressing unit 33 can accurately position the contact portion, the photosensitive drum 1, and the charging roller 5 relative to each other. That is, the process cartridge can be stably and firmly held and positioned, so that stable current can be maintained. In addition, a strong and stable contact path can be formed near the ends of the photosensitive drum 1 and the charging roller 5, so that the contact path in the process cartridge can be shortened, and the process cartridge can be manufactured at low cost. In addition, in the longitudinal direction of the photosensitive drum 1, the main body charging contact 37 and the charging contact 6 are disposed between the first support portion 41R1 and the second support portion 41L1.

[0090] As described above, after the pressing units 33 and 34 are in a state of pressing the process cartridge from above, the main body developing contact 38 contacts the cartridge developing contact 2 (see FIG. 3(b)) connected to each developing roller 3, and the transfer unit 12 rotates upward around the drive roller 14. As a result, the photosensitive drum 1 of each process cartridge contacts the intermediate transfer belt 13.

[0091] As described above, when the front door 31 is closed and the printer 100 is ready to form images, the positioning shaft 50 engages with the positioning grooves 41bL, 41bR on the front side of the cartridge tray 40. At this time, since the positioning grooves 41bL, 41bR are provided with the inclined surfaces 41f, the cartridge tray 40 is pulled in the insertion direction Y1 based on the weight of the cartridge tray 40 and the downward force of the pressing units 33, 34. As a result, the positioning surface 41e is pressed against the positioning shaft 50, and the cartridge tray 40 can be accurately positioned in the insertion direction Y1.

[0092] Furthermore, the positioning shaft 49 engages with the positioning grooves 36aL, 36aR at the rear side of the cartridge tray 40. At this time, the end 49a of the positioning shaft 49 fits into the fitting grooves of the positioning grooves 36aL, 36aR, so that the cartridge tray 40 can be prevented from rotating in a direction perpendicular to the mounting direction Y1, i.e., around the positioning shaft 50.

[0093] The positioning shaft 50 and the positioning grooves 36aL, 36aR provided in the apparatus main body 100A, and the positioning grooves 41bL, 41bR provided in the cartridge tray 40 and the positioning shaft 50 constitute a positioning mechanism 60 (see FIGS. 11(a) and 11(d)). The positioning mechanism 60 positions the cartridge tray 40 in the apparatus main body 100A.

[0094] Furthermore, the positioning shaft 50 is supported from below by a rib 46b provided on the connecting member 46 of the cartridge tray 40, so that the downward bending of the positioning shaft 50 is restricted. Also, the locking portions 46c, 46c provided on the connecting member 46 suppress deformation of the cartridge tray 40 itself. Also, the positioning shaft 50 on the rear side of the cartridge tray 40 is supported from below by the shaft contact portion 42c, so that the downward bending of the positioning shaft 49 is restricted. With this configuration, the shaft diameter of the positioning shafts 49, 50 can be made small and they can be made of an inexpensive resin material, so that the cost and size can be reduced.

[0095] As a result, the cartridge tray 40 can be positioned in the apparatus main body 100A with high accuracy at the mounting position. In particular, during image formation, each process cartridge held in the cartridge tray 40 is pressed from above by the pressing units 33, 34, but this does not affect the positioning accuracy of the cartridge tray 40. Therefore, the positioning accuracy of each process cartridge held in the cartridge tray 40, specifically, the positioning accuracy of the photosensitive drum 1 and intermediate transfer belt 13, is improved, and high-quality images can be formed.

[0096] In addition, the cartridge tray 40 is biased forward at the mounting position by the action of the inclined surface 41f at the front side of the cartridge tray 40 and the pressure of the tray pressing unit 51 at the rear side. This makes it possible to reduce the positional deviation of the cartridge tray 40 due to vibrations during image formation, etc. In addition, by generating a pressing force at the front and rear of the cartridge tray 40, the pressing force can be dispersed and the biasing spring of the tray pressing unit 51 can be made to have a small elastic force. This makes it possible to reduce the size and cost of the tray pressing unit 51.

[0097] The positioning shaft 50 and the positioning grooves 41bL, 41bR included in the positioning mechanism 60 may be configured to be interchangeable if they are arranged separately on either the apparatus main body 100A or the cartridge tray 40. Moreover, the positioning grooves 36aL, 36aR and the positioning shaft 50 included in the positioning mechanism 60 may be configured to be interchangeable if they are arranged separately on either the apparatus main body 100A or the cartridge tray 40.

[0098] Furthermore, the positioning shaft 49 does not have to be a through shaft that runs over the entire length of the cartridge tray 40 in the left-right direction, but may simply have two protruding portions formed to protrude on both sides of the cartridge tray 40.

[0099] In addition, although each process cartridge is formed with the drum unit OP and the developing unit DP integrally, they may be configured separately. For example, the cartridge tray 40 may hold only the drum unit OP or only the developing unit DP. [Explanation of symbols]

[0100] 100... printer, 100A... apparatus main body, PPY, PPM, PPC, PPK... process cartridge, 40... cartridge tray, 40a... mounting portion, 41R, 41L... tray side plate, 41R1... first support portion, 41R2... first outer portion, ... first connection portion, 41L1... second support portion, 41L2... second outer portion, 41L3... second connection portion, 41gR, 41hR, 41iR, 41jR, 41gL, 41hL, 41iL, 41jL... cartridge engagement portion, 1b... earth member, 48... wire

Claims

1. An image forming apparatus in which a plurality of cartridges are removably mounted, an apparatus main body having a main body side plate, a main body side positioning shaft supported by the main body side plate, and a main body side charging contact; a tray unit to which the plurality of cartridges are removably attached, the tray unit being configured to be movable in an insertion direction relative to the device body from an external position located outside the device body to an internal position located inside the device body, a first tray side plate formed of metal, the first tray side plate having a plurality of cartridge positioning portions, an inclined surface inclined downwardly toward the downstream side in the insertion direction, and a positioning surface; A tray unit having Equipped with each of the plurality of cartridges is a process cartridge having a photosensitive drum, a charging member configured to charge the photosensitive drum, and a cartridge-side charging contact capable of contacting the main body-side charging contact and electrically connected to the charging member; the tray unit is configured to position the process cartridge at an image forming position by contacting the process cartridge, when the tray unit is in the internal position, the weight of the tray unit acts on the body-side positioning shaft, causing the inclined surface to receive a reaction force from the body-side positioning shaft, the reaction force including a component force directed in the insertion direction such that the positioning surface is pressed against the body-side positioning shaft.

1. An image forming apparatus comprising:

2. The body side plate has a body side positioning groove, the tray unit has a tray side positioning shaft that engages with the main body side positioning groove when the tray unit is in the internal position; 2. The image forming apparatus according to claim 1,

3. An image forming apparatus as described in Claim 2, characterized in that the tray side positioning axis penetrates the first tray side plate.

4. The device body includes a pressing member, 4. The image forming apparatus according to claim 1, wherein the pressing member is configured to press the cartridge from above.

5. Further comprising a door attached to the device body, the door is movable between a closed position that covers the tray unit in the internal position and an open position that exposes the tray unit in the internal position; 5. The image forming apparatus according to claim 4, wherein the pressing member moves in conjunction with opening and closing of the door.

6. An image forming apparatus as described in claim 4 or 5, characterized in that the pressing member is provided with the main body side charging contact.

7. An image forming apparatus as described in any one of claims 1 to 6, characterized in that the tray unit further has a second tray side plate formed of metal and a connecting member connecting the first tray side plate and the second tray side plate, and a mounting portion into which the process cartridge is mounted is formed between the first tray side plate and the second tray side plate.

8. In the direction of the rotation axis of the photosensitive drum, the position where the main body side charging contact and the cartridge side charging contact contact are in contact is a position between the first tray side plate and the second tray side plate.

8. The image forming apparatus according to claim 7,

9. The first tray side plate has a plurality of cartridge positioning portions, each of the plurality of cartridge positioning portions is configured to position the process cartridge at the image forming position by abutting against the process cartridge; 9. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-layered image forming apparatus.

10. An image forming device as described in Claim 9, characterized in that the position at which the main body side charging contact and the cartridge side charging contact contact is higher than the position at which each of the multiple cartridge positioning portions abuts against the process cartridge.

11. The process cartridge includes a cartridge contact for connecting the photosensitive drum to a ground potential, the tray unit has a tray contact electrically connected to the cartridge contact, the tray contact having an abutment portion that abuts against the cartridge contact, the first tray side plate integrally includes a first support portion having the plurality of cartridge positioning portions, a first outer portion, and a first connection portion connecting the first support portion and the first outer portion, 11. The image forming apparatus according to claim 9, wherein the contact portion is located between the first support portion and the first outer portion in the direction of the rotation axis of the photosensitive drum.

12. An apparatus body having a body side plate, a body side positioning shaft supported by the body side plate, and a body side charging contact; A plurality of cartridges; a tray unit to which the plurality of cartridges are removably attached, the tray unit being configured to be movable in an insertion direction relative to the device body from an external position located outside the device body to an internal position located inside the device body, A first tray side plate made of metal, the first tray side plate having a plurality of cartridge positioning portions and a first tray side plate having an inclined surface that is inclined downward toward the downstream side in the insertion direction and a positioning surface; A tray unit having Equipped with each of the plurality of cartridges is a process cartridge having a photosensitive drum, a charging member configured to charge the photosensitive drum, and a cartridge-side charging contact capable of contacting the main body-side charging contact and electrically connected to the charging member; the tray unit is configured to position the process cartridge at an image forming position by contacting the process cartridge, when the tray unit is in the internal position, the weight of the tray unit acts on the body-side positioning shaft, causing the inclined surface to receive a reaction force from the body-side positioning shaft, the reaction force including a component force directed in the insertion direction such that the positioning surface is pressed against the body-side positioning shaft.

1. An image forming apparatus comprising:

13. The body side plate has a body side positioning groove, the tray unit has a tray side positioning shaft that engages with the main body side positioning groove when the tray unit is in the internal position; 13. The image forming apparatus according to claim 12.

14. An image forming apparatus as described in Claim 13, characterized in that the tray side positioning axis penetrates the first tray side plate.

15. The device body includes a pressing member, 15. The image forming apparatus according to claim 12, wherein the pressing member is configured to press the cartridge from above.

16. Further comprising a door attached to the device body, the door is movable between a closed position that covers the tray unit in the internal position and an open position that exposes the tray unit in the internal position; 16. The image forming apparatus according to claim 15, wherein the pressing member moves in conjunction with opening and closing of the door.

17. An image forming apparatus as described in claim 15 or 16, characterized in that the pressing member is provided with the main body side charging contact.

18. The tray unit further has a second tray side plate formed of metal, and a connecting member connecting the first tray side plate and the second tray side plate, and a mounting portion into which the process cartridge is mounted is formed between the first tray side plate and the second tray side plate.

18. The image forming apparatus according to claim 12,

19. In the direction of the rotation axis of the photosensitive drum, the position where the main body side charging contact and the cartridge side charging contact contact are in contact is a position between the first tray side plate and the second tray side plate.

20. The image forming apparatus according to claim 18,

20. The first tray side plate has a plurality of cartridge positioning portions, each of the plurality of cartridge positioning portions is configured to position the process cartridge at the image forming position by abutting against the process cartridge; 20. The image forming apparatus according to claim 12, wherein the image forming apparatus is a multi-layered image forming apparatus.

21. An image forming apparatus as described in Claim 20, characterized in that the position at which the main body side charging contact and the cartridge side charging contact contact is higher than the position at which each of the multiple cartridge positioning portions abuts against the process cartridge.

22. The process cartridge includes a cartridge contact for connecting the photosensitive drum to a ground potential, the tray unit has a tray contact electrically connected to the cartridge contact, the tray contact having an abutment portion that abuts against the cartridge contact, the first tray side plate integrally includes a first support portion having the plurality of cartridge positioning portions, a first outer portion, and a first connection portion connecting the first support portion and the first outer portion, 22. The image forming apparatus according to claim 20, wherein the contact portion is located between the first support portion and the first outer portion in the direction of the rotation axis of the photosensitive drum.

Images