Image forming apparatus

Abstract

To provide an image forming apparatus that comprises a photoreceptor unit as a reference of positioning of a developing unit, and ensures the posture of the developing unit when the developing unit is mounted on an apparatus body but the photoreceptor unit is not mounted on the apparatus body.SOLUTION: An image forming apparatus comprises a photoreceptor unit positioned relative to an apparatus body and a developing unit positioned relative to the photoreceptor unit. When the photoreceptor unit is mounted on the apparatus body and the developing unit is mounted on the apparatus body, a regulation unit is urged so that the position of the regulation unit is moved to a retreat position. When the photoreceptor unit is mounted on the apparatus body and the developing unit is not mounted on the apparatus body, the regulation unit is urged so that the position of the regulation unit is moved to the retreat position. When the photoreceptor unit is not mounted on the apparatus body and the developing unit is mounted on the apparatus body, the regulation unit is urged so that the position of the regulation unit is moved to a regulation position.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus, such as a copying machine, a printer, or a facsimile machine, which is provided with a developing unit that is detachable from the image forming apparatus and is independent of a photosensitive unit. [Background technology]

[0002] An image forming apparatus is described that includes a photosensitive unit having a photosensitive member and a developing unit having a developer carrier that carries and transports developer to develop an electrostatic latent image formed on the photosensitive member, and the developing unit is detachable from the main body of the apparatus independently of the photosensitive unit. This image forming apparatus is provided with a door for accessing the photosensitive unit and the developing unit, and when a user or a service person opens the door, the pressure on the developing unit is released, allowing the photosensitive unit and the developing unit to be detached or replaced (see Patent Document 1).

[0003] Furthermore, Patent Document 2 describes an image forming apparatus in which, with the photosensitive unit and the developing unit both attached to the apparatus body, the photosensitive unit is positioned relative to the apparatus body, and the developing unit is positioned relative to the photosensitive unit. Specifically, with the photosensitive unit and the developing unit both attached to the apparatus body, the developing unit is positioned relative to the photosensitive unit by the bearings at both ends of the developer carrier in the longitudinal direction abutting against the bearings at both ends of the photosensitive member in the longitudinal direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-187738 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-133739 Summary of the Invention [Problem to be solved by the invention]

[0005] In a configuration in which the photosensitive unit is the reference for positioning the developing unit as in Patent Document 2, let us consider a case in which the developing unit is attached to the device body but the door can be closed even when the photosensitive unit is not attached to the device body. In this case, if the door is closed when the photosensitive unit is not attached to the device body, the developing unit will be pressurized, causing the unpositioned developing unit to assume an unexpected position, which could cause it to collide with other units inside the device body due to vibrations during transportation of the image forming apparatus, etc.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus in which the photosensitive unit is a reference for positioning the developing unit, and in which the developing unit is mounted in the apparatus main body but the photosensitive unit is not mounted in the apparatus main body, and the posture of the developing unit can be guaranteed. [Means for solving the problem]

[0007] In order to achieve the above object, an image forming apparatus according to one aspect of the present invention has the following configuration: That is, an apparatus main body, a photosensitive unit having a photosensitive member on which an electrostatic latent image is formed and detachable from the apparatus main body, the photosensitive member being positioned relative to the apparatus main body, a developing unit having a developer carrier that carries and transports developer to develop the electrostatic latent image formed on the photosensitive member and detachable from the apparatus main body, the developing unit being positioned relative to the photosensitive member unit attached to the apparatus main body, a pressure unit that is movable between a first position that presses the developing unit toward the photosensitive member unit and a second position that releases the pressure of the developing unit, a restricting position that restricts movement of the pressure unit from the second position to the first position, and a restricting position that does not restrict movement of the pressure unit from the second position to the first position. a regulating portion that is movable between a retracted position where the regulating portion is retracted from the device and a retracted position where the regulating portion is retracted from the device; and a biasing portion that biases the regulating portion so that the regulating portion is positioned at the retracted position when the photosensitive unit is attached to the device body and the developing unit is attached to the device body, and biases the regulating portion so that the regulating portion is positioned at the retracted position when the photosensitive unit is attached to the device body and the developing unit is not attached to the device body, and biases the regulating portion so that the regulating portion is positioned at the regulating position when the photosensitive unit is not attached to the device body and the developing unit is attached to the device body. [Effects of the Invention]

[0008] According to the present invention, in a configuration in which the photosensitive unit is the reference for positioning the developing unit, the attitude of the developing unit can be guaranteed when the developing unit is mounted on the device body but the photosensitive unit is not mounted on the device body. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram illustrating a configuration of an image forming apparatus according to a first embodiment. [Figure 2] FIG. 2 is a schematic view showing the configuration of a development unit according to the first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing the configuration of a developing unit according to the first embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating a configuration of a photosensitive unit according to the first embodiment. [Figure 5] FIG. 2 is a schematic diagram illustrating a configuration of a photosensitive unit according to the first embodiment. [Figure 6] FIG. 2 is a cross-sectional view showing the configuration of a photosensitive unit according to the first embodiment. [Figure 7] 2 is a schematic diagram showing the configuration of a pressure mechanism and a stopper mechanism according to the first embodiment. FIG. [Figure 8] 2 is a schematic diagram showing the configuration of a pressure mechanism and a stopper mechanism according to the first embodiment. FIG. [Figure 9] 2 is a schematic diagram showing the configuration of a pressure mechanism and a stopper mechanism according to the first embodiment. FIG. [Figure 10] FIG. 10 is an external view showing the configuration of a pressure mechanism and a door according to a second embodiment. [Figure 11] FIG. 10 is a schematic view showing the configuration of a stopper mechanism according to a second embodiment. [Figure 12] FIG. 10 is a schematic diagram showing the configuration of a pressure mechanism and a door according to a second embodiment. [Figure 13] FIG. 10 is a schematic view showing the configuration of a stopper mechanism according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the present invention, and not all of the combinations of features described in the first embodiment are necessarily essential to the solution of the present invention. The present invention can be implemented in a variety of applications, such as printers, various printing machines, copiers, fax machines, and multifunction machines.

[0011] [First embodiment] (Configuration of image forming device) First, the configuration of the image forming apparatus according to the first embodiment will be described with reference to the schematic diagram of FIG.

[0012] 1, image forming apparatus 1 is a so-called intermediate transfer tandem type apparatus in which four color image forming units UY, UM, UC, and UK are arranged inside apparatus main body 100 facing an intermediate transfer belt 30. That is, four sets of image forming units UY, UM, UC, and UK for yellow (Y), magenta (M), cyan (C), and black (K) are arranged. However, the number of colors is not limited to four, and the order of the colors is not limited to this.

[0013] Each of these image forming units UY, UM, UC, and UK includes a developing unit 10 and a photosensitive unit 20. The image forming unit UY (UM to UK) is configured by combining the developing unit 10 and the photosensitive unit 20, which are each formed independently.

[0014] Next, we will explain the recording material conveyance process of the image forming apparatus 1. Recording material S is stored in a stacked form in a recording material storage case (cassette) 70, and is fed to the conveyance path 40 in accordance with the image formation timing. The recording material S fed from the recording material storage case (cassette) 70 is subjected to skew correction and timing correction before being sent to the secondary transfer section T2. ​​The secondary transfer section T2 is a transfer nip section formed by the opposing secondary transfer outer roller 31 and secondary transfer inner roller 32, and a toner image is attracted onto the recording material S by applying a predetermined pressure force and an electrostatic load bias.

[0015] The process of forming an image sent to the secondary transfer unit T2 at the same timing as the process of conveying the recording material S to the secondary transfer unit T2 described above will now be described. First, the image forming units UY to UK will be described. However, since the configurations of the image forming units UY to UK for each color are basically the same except for the color of the toner, the yellow image forming unit UY will be described below as a representative.

[0016] The image forming section UY is mainly composed of a developing unit 10 having a developing sleeve 11 as a developer carrier that carries and transports developer to develop an electrostatic latent image formed on a photosensitive drum 21, and a photosensitive unit 20 having the photosensitive drum 21 and a charging roller 22. The developing unit 10 and the photosensitive unit 20 will be described later.

[0017] The surface of the rotationally driven photosensitive drum 21 is uniformly charged in advance by the charging roller 22, and then an electrostatic latent image is formed on it by the exposure unit 60, which is driven based on image information signals. Next, the electrostatic latent image formed on the photosensitive drum 21 is developed with toner by the developing sleeve 11, and then made into a visible image.

[0018] Thereafter, a predetermined pressure and electrostatic load bias are applied by primary transfer device 33, which is disposed opposite image forming unit UY with intermediate transfer belt 30 sandwiched therebetween, and the toner image formed on photosensitive drum 21 is primarily transferred onto intermediate transfer belt 30. A two-component developer, which is a mixture of toner and magnetic carrier, is used as the developer, and the developer is supplied to development unit 10 from toner bottle 50 set in image forming unit UY via supply path 51 by a toner supply unit (not shown).

[0019] The intermediate transfer belt 30 is an endless belt that is stretched by various rollers, such as an inner secondary transfer roller 32, a driven roller 34, and a tension roller 35, and is driven to rotate in the direction of arrow R1 in the figure. The inner secondary transfer roller 32 also serves as a drive roller that drives the intermediate transfer belt 30. The image formation processes for each color, which are performed in parallel by the image forming units UY to UK described above, are performed in a timed manner to sequentially overlay the toner images of the upstream colors that have been primarily transferred onto the intermediate transfer belt 30. As a result, a full-color toner image is finally formed on the intermediate transfer belt 30 and is transported to the secondary transfer unit T2.

[0020] Through the conveying process and image forming process described above, the timing of the recording material S and the full-color toner image is synchronized at the secondary transfer portion T2, and secondary transfer is performed. The recording material S is then conveyed to the fixing device 80, where the toner image is melted and fixed onto the recording material S by a predetermined pressure and heat. The recording material S with the image fixed in this manner is discharged onto the discharge tray 90 by the discharge rollers 41.

[0021] Generally, the developing unit 10 and the photosensitive unit 20 have a shorter lifespan than the other image forming process means (such as the fixing device 80) that make up the image forming apparatus 1, and therefore may need to be replaced. For this reason, an insertion port (not shown) that allows the developing unit 10 and the photosensitive unit 20 to be inserted and removed is provided for each image forming section UY to UK on the front side of the apparatus main body 100 (the front side in the insertion direction, the front side in FIG. 1). Doors (not shown) that can be opened and closed are provided to cover the insertion ports for each color individually or to cover the entire apparatus.

[0022] The developing unit 10 and the photosensitive unit 20 are mounted independently in the apparatus main body 100 in consideration of the case where the set durability life is different or the ease of replacement in the event of a malfunction.

[0023] The insertion direction (longitudinal direction) of the developing unit 10 and the photosensitive unit 20 is the same as the direction of the rotation axis of the developing sleeve 11, and also the same as the direction of the rotation axis of the photosensitive drum 21. The developing unit 10 and the photosensitive unit 20 operate by receiving a driving force and a supply of electric power from the device main body 100 in which they are mounted. In order to transmit a driving force and a supply of electric power between the device main body 100 and the developing unit 10 and the photosensitive unit 20, the developing unit 10 and the photosensitive unit 20 are mounted to the device main body 100 via a coupling portion (not shown).

[0024] (Configuration of the development unit) Next, the configuration of the developing unit 10 according to the first embodiment will be described with reference to the schematic diagram of FIG. 2 and the cross-sectional view of FIG.

[0025] As shown in FIG. 2, the developing unit 10 includes a developing container 110 and a developing sleeve 11. The developing sleeve 11 is rotatably supported within the developing container 110 by bearings 13a and 13b disposed at both ends, front and rear, in the insertion direction (the direction of the arrow X in the figure). As will be described later, the bearings 13a and 13b also function as gap forming members between the developing sleeve 11 and the photosensitive drum 21. Furthermore, the developing unit 10 is swingably supported relative to the apparatus main body 100 via fitting holes 115a and 115b.

[0026] The developing container 110 contains a two-component developer (hereinafter simply referred to as developer) consisting of non-magnetic toner and magnetic carrier. As shown in Fig. 3, the interior of the developing container 110 is partitioned into two chambers (developing chamber 16a and stirring chamber 16b) by a partition wall 15, and these developing chamber 16a and stirring chamber 16b are connected at both ends of the developing container 110 in the longitudinal direction.

[0027] A transport screw 12a is rotatably supported in the developing chamber 16a, and an agitating screw 12b is rotatably supported in the agitating chamber 16b. The transport screw 12a and the agitating screw 12b are arranged adjacent to each other and in parallel so that their rotation axes are aligned with the rotation axis of the developing sleeve 11. The developer is circulated and transported between the developing chamber 16a and the agitating chamber 16b as the transport screw 12a and the agitating screw 12b are driven. The developing sleeve 11 carries and transports the developer supplied from the developing chamber 16a.

[0028] The regulating blade 14 is provided at a position close to the surface of the developing sleeve 11, and forms a thin layer of developer on the surface of the developing sleeve 11. The developing sleeve 11 then supplies the developer to the photosensitive drum 21 at a development position facing the photosensitive drum 21. As a result, the electrostatic latent image formed on the photosensitive drum 21 is developed.

[0029] (Photosensitive unit configuration) Next, the configuration of the photosensitive unit 20 according to the first embodiment will be described with reference to the schematic diagram of FIG. 4, the schematic diagram of FIG. 5, and the cross-sectional view of FIG.

[0030] 4 and 5, the photosensitive unit 20 has a photosensitive drum 21 rotatably supported in a housing 24, and a charging roller 22. Bearings 25a and 25b, which are located at both ends on the front and rear sides in the insertion direction (the direction of the arrow X in the drawings), are provided coaxially with the rotation axis of the photosensitive drum 21.

[0031] The housing 24 is opened at a location facing the developing sleeve 11 of the developing unit 10 when the photosensitive unit 20 is attached to the device main body 100, and is arranged so that a part of the photosensitive drum 21 is exposed from the opened location.

[0032] 6, charging roller 22 uniformly charges the surface of photosensitive drum 21, which is driven to rotate. Photosensitive drum 21 is connected to a drive source (not shown) of apparatus main body 100, and is rotated by a driving force transmitted from the drive source. On the other hand, charging roller 22 is pressed against photosensitive drum 21, and rotates in accordance with the rotation of photosensitive drum 21.

[0033] After the photosensitive drum 21 is charged by the charging roller 22, an electrostatic latent image is formed on it by an exposure unit 60 provided in the apparatus main body 100. The electrostatic latent image formed on the photosensitive drum 21 is then visualized through toner development by the developing sleeve 11, and the toner image formed on the photosensitive drum 21 is transferred to a recording material S or the like. Thereafter, a drum cleaning blade 23, which is in contact with the photosensitive drum 21 with a predetermined pressure, removes any untransferred toner remaining on the photosensitive drum 21.

[0034] Furthermore, the bearings 25a and 25b that support the photosensitive drum 21 are abutted against the bearings 13a and 13b that support the developing sleeve 11 when the photosensitive unit 20 is attached to the apparatus main body 100. Therefore, the bearings 25a and 25b also function as gap forming members that ensure a gap between the photosensitive drum 21 and the developing sleeve 11 (hereinafter referred to as an SD gap).

[0035] When the developing unit 10 and the photosensitive unit 20 are mounted in the apparatus main body 100, the developing unit 10 is urged against the photosensitive unit 20, and the bearings 13a, 13b and the bearings 25a, 25b are butted against each other, thereby ensuring the positions of the developing sleeve 11 and the photosensitive drum 21.

[0036] In this configuration, if the bearings 13a, 13b and the bearings 25a, 25b remain in abutted state, there is a risk of scratches being caused on the bearings 13a, 13b and the bearings 25a, 25b when the photosensitive unit 20 is inserted into or removed from the apparatus main body 100, such as when replacing the photosensitive unit 20. Therefore, it is necessary to separate the developing unit 10 and the photosensitive unit 20 and release the abutment between the bearings 13a, 13b and the bearings 25a, 25b before the photosensitive unit 20 can be attached to or removed from the apparatus main body 100. After the abutment between the bearings 13a, 13b and the bearings 25a, 25b is released, a sufficient gap can be secured between the bearings 13a, 13b and the bearings 25a, 25b so that they do not come into contact with each other, and therefore there is no risk of scratches being caused when the photosensitive unit 20 is inserted or removed.

[0037] (Configuration of pressure mechanism and stopper mechanism) Next, the configurations of the pressure mechanism and stopper mechanism according to the first embodiment will be described with reference to the schematic diagrams of FIGS. 7, 8, and 9. FIG.

[0038] 7(a) and (b) show a state in which the developing unit 10 is attached to the apparatus main body 100 and the photosensitive unit 20 is not attached to the apparatus main body 100. As shown in FIGS. 7(a) and (b), the handle 150 is in a position where the pressure on the developing unit 10 is released (hereinafter referred to as the second position), and the developing unit 10 is separated from the developing position.

[0039] 8(a) and (b) show a state in which the developing unit 10 is attached to the apparatus main body 100 and the photosensitive unit 20 is attached to the apparatus main body 100. As shown in FIGS. 8(a) and (b), the handle 150 is in the second position, and the developing unit 10 is spaced from the developing position.

[0040] 9(a) and (b) show a state in which the photosensitive unit 20 is attached to the apparatus main body 100 and the photosensitive unit 20 is attached to the apparatus main body 100. As shown in FIGS. 9(a) and (b), the handle 150 is in a position where it presses the developing unit 10 (hereinafter referred to as the first position), and the developing unit 10 is pressed toward the photosensitive unit 20.

[0041] 7(a), the handle 150 is provided to be rotatable about an axis 150a that is parallel to the axis of the developing unit 10 relative to the apparatus main body 100. At the tip of the handle 150, a pressure applying portion 150c that is biased by a pressure applying spring 150b as a biasing portion is provided, and a restricting portion 150d that restricts the rotational movement of the handle 150 is provided.

[0042] The developing unit 10 is provided in the device main body 100, and the fitting hole 115a and the swing shaft 170a on the front side in the insertion direction (the direction of the arrow X in the figure) are supported so as to be swingable around a swing shaft (not shown) that fits into the fitting hole 115b on the back side in the insertion direction (the direction of the arrow X in the figure).

[0043] Furthermore, a drum rail 106 is provided inside the device body 100 to allow the photosensitive unit 20 to be easily mounted at a predetermined position inside the device body 100. The drum rail 106 has a positioning portion 106a that protrudes from the guide surface of the drum rail 106 and is provided on the front side in the insertion direction (the direction of the arrow X in the figure).

[0044] 7(a) and 7(b), the drum rail 106 is provided with a stopper mechanism 160 that restricts the rotation of the handle 150. The stopper mechanism 160 includes a stopper member 160a and a spring 160b that serves as a biasing portion that biases the stopper member 160a.

[0045] In the state shown in FIG. 7(a), the handle 150 is in the second position, and the developing unit 10 is waiting at a position separated from the photosensitive unit 20 by its own weight.

[0046] That is, when the developing unit 10 and the photosensitive unit 20 are both attached to the apparatus main body 100, the developing unit 10 is not positioned relative to the photosensitive unit 20. If the developing unit 10 is not positioned in this way and vibrations are applied from outside the apparatus main body 100 during transportation of the image forming apparatus 1, there is a risk that the vibrations will be transmitted to the developing unit 10.

[0047] For example, consider a case where a user or a service person closes a door (not shown) for accessing the photosensitive unit 20 or the developing unit 10 while the handle 150 is in the second position.

[0048] In this case, the developing unit 10 attached to the apparatus main body 100 is not pressurized by the handle 150, and is in an unstable state separated from the photosensitive unit 20 by its own weight. If a user or service person unknowingly attempts to move the image forming apparatus 1 in this state where the developing unit 10 is not positioned relative to the photosensitive unit 20, the developing unit 10 may vibrate and collide with an adjacent unit inside the apparatus main body 100.

[0049] For this reason, the door is often provided with a foolproof shape that will interfere with part of the handle 150 when a user or service person tries to close the door while the handle 150 is in the second position. This makes it possible to prevent the image forming apparatus 1 from being moved as much as possible while the developing unit 10 is not positioned relative to the photosensitive unit 20 and the developing unit 10 is in an unstable position.

[0050] However, as shown in Figures 7(a) and 7(b), it is necessary to consider the possibility that the handle 150 may be allowed to be rotated from the second position to the first position when the photosensitive unit 20 is not attached to the device main body 100, and a user or service person may close the door.

[0051] This is because although the developing unit 10 is pressed by the handle 150, the developing unit 10 is not positioned relative to the photosensitive unit 20 because the photosensitive unit 20 is not attached to the device main body 100. Therefore, when the photosensitive unit 20 is not attached to the device main body 100, the unpositioned developing unit 10 will assume an unexpected posture, and there is a risk that it will collide with other units inside the device main body 100 due to vibrations during transportation of the image forming apparatus 1.

[0052] 7(b), when the handle 150 is attempted to be rotated without the photosensitive unit 20 being attached to the apparatus main body 100, the restricting portion 150d abuts against the stopper member 160a. This makes it possible to restrict the rotation of the handle 150.

[0053] In this way, it is possible to prevent the door from being closed when the photosensitive unit 20 is not attached to the apparatus main body 100 and the developing unit 10 is pressed by the handle 150. Therefore, it is possible to prevent the developing unit 10 that is not positioned from colliding with other units in the apparatus main body 100 due to vibrations during transportation of the image forming apparatus 1, etc.

[0054] 8(a), the photosensitive unit 20 is attached by being pushed into the device main body 100 from the insertion opening in the insertion direction (the direction of the arrow X in the figure) toward the back. The drum rail 106 as a guide has a guide surface that extends in the insertion / removal direction (longitudinal direction) of the photosensitive unit 20, and the photosensitive unit 20 can be slidably mounted thereon.

[0055] The positioning portion 106a as an engaging portion is pressed against the photosensitive unit 20 when the photosensitive unit 20 is inserted, and is elastically deformed to retreat into the drum rail 106. In contrast, the photosensitive unit 20 is provided with a communication hole 20b having an opening on its lower surface.

[0056] When the photosensitive unit 20 is inserted to a predetermined position in the device main body 100, the positioning portion 106a, which has been retracted in the drum rail 106, engages with the communication hole 20b, which serves as the engaged portion, and the photosensitive unit 20 is attached to the device main body 100.

[0057] The engagement of the positioning portion 106a with the communication hole 20b prevents the photosensitive unit 20 from moving forward in the insertion direction, and fixes the photosensitive unit 20 so that it does not jump out of the apparatus main body 100.

[0058] In the state shown in FIGS. 8(a) and 8(b), the bearings 13a and 13b of the developing sleeve 11 and the bearings 25a and 25b of the photosensitive drum 21 are not in contact with each other.

[0059] On the other hand, the communication hole 20b having an opening on the lower surface of the photosensitive unit 20 penetrates the inside of the photosensitive unit 20 and has the other opening on the front surface on the near side in the insertion direction. A release member 26 is provided inside this communication hole 20b.

[0060] When the photosensitive unit 20 is attached to the apparatus main body 100, one end of the release member 26 protrudes from the front surface of the photosensitive unit 20, and the other end contacts the positioning portion 106a engaged with the communication hole 20b. When the front surface end of the release member 26 is pressed downward (in the direction of arrow E in the figure), the other end presses down the positioning portion 106a.

[0061] This allows the engagement between the positioning portion 106a and the communication hole 20b to be released, i.e., the state in which the photosensitive unit 20 is attached to the apparatus main body 100 is released, and the photosensitive unit 20 can be removed from the apparatus main body 100.

[0062] 8(b), when the photosensitive unit 20 is attached to the apparatus main body 100, the stopper member 160a is pressed against the spring 160b. Therefore, the stopper member 160a is biased toward the front in the insertion direction by the spring 160b in addition to the coupling spring of the coupling portion (not shown). In other words, when the photosensitive unit 20 is attached to the apparatus main body 100, the stopper member 160a is pressed in, and the handle 150 can be rotated.

[0063] 9(a) and 9(b), a user or service technician rotates the handle 150. By rotating the handle 150, the pressure applying portion 150c, which is biased by the pressure applying spring 150b, presses the developing unit 10 around the swing shaft 170a, thereby biasing it to position relative to the photosensitive unit 20. In this case, the bearings 13a and 13b of the developing sleeve 11 abut against the bearings 25a and 25b of the photosensitive drum 21, and the developing unit 10 is positioned with the SD gap ensured. As a result, the door is closed with the developing unit 10 properly positioned.

[0064] As described above, in the image forming apparatus 1 according to the first embodiment, the developing unit 10 is positioned and biased relative to the photosensitive unit 20 which is positioned in the apparatus main body 100. In such an image forming apparatus 1, when the photosensitive unit 20 is not attached to the apparatus main body 100, the handle 150 which applies pressure to the developing unit 10 abuts against the stopper member 160a, thereby restricting the rotational movement of the handle 150.

[0065] This prevents the door from being closed when the photosensitive unit 20 is not attached to the apparatus main body 100 and the developing unit 10 is pressed by the handle 150. Therefore, it is possible to prevent the developing unit 10, which is not positioned, from colliding with other units inside the apparatus main body 100 due to vibrations during transportation of the image forming apparatus 1.

[0066] That is, in the first embodiment, the photosensitive unit is positioned relative to the apparatus main body, and the developing unit is positioned relative to the photosensitive unit. In this configuration, when the photosensitive unit is attached to the apparatus main body and the developing unit is attached to the apparatus main body, the regulating portion is urged so that the regulating portion is positioned at the retracted position. Also, in this configuration, when the photosensitive unit is attached to the apparatus main body and the developing unit is not attached to the apparatus main body, the regulating portion is urged so that the regulating portion is positioned at the retracted position. Also, in this configuration, when the photosensitive unit is not attached to the apparatus main body and the developing unit is attached to the apparatus main body, the regulating portion is urged so that the regulating portion is positioned at the regulating position.

[0067] According to this first embodiment, the photosensitive unit is the reference for positioning the developing unit, and the posture of the developing unit can be guaranteed even when the developing unit is attached to the device main body but the photosensitive unit is not attached to the device main body.

[0068] [Second embodiment] In the second embodiment, a door is provided for each of the image forming units UY to UK, covering the insertion openings of the respective colors, and when the door is opened, the developing unit 10 is separated from the photosensitive unit 20. Meanwhile, a configuration will be described in which the developing unit 10 is pressed against the photosensitive unit 20 when the door is closed.

[0069] Furthermore, the developing unit 10 in the second embodiment is described as being detachable from the apparatus main body 100. Furthermore, the attachment and detachment of the photosensitive unit 20 to the apparatus main body 100 in the second embodiment is the same as in the first embodiment, so detailed description thereof will be omitted.

[0070] FIG. 10 is an external view showing the configuration of the pressure mechanism and the door according to the second embodiment.

[0071] Fig. 11 is a schematic diagram showing the configuration of a stopper mechanism according to the second embodiment. Specifically, Fig. 11 shows the configuration of a connection portion between the door and the pressure mechanism, and the stopper mechanism that restricts the opening and closing operation of the door.

[0072] 12(a) and 12(b) are schematic diagrams showing the configuration of the pressure mechanism and door according to the second embodiment. Specifically, Fig. 12 shows the opening and closing operations of the door and the state of the pressure mechanism.

[0073] Fig. 13 is a schematic diagram showing the configuration of the stopper mechanism according to the second embodiment. Specifically, Fig. 13 shows the state of the stopper mechanism depending on the combination of the state in which the developing unit 10 and the photosensitive unit 20 are attached to the apparatus main body 100 and the state in which they are not attached.

[0074] 10, the pressure mechanism 200 has a spacing link 102 and a developing rail 103. The developing rail 103 has a guide surface extending in the insertion direction (longitudinal direction), and the developing unit 10 can be slidably mounted thereon. The developing unit 10 is guided into the apparatus main body 100 by sliding on the developing rail 103.

[0075] A spacing link 102 is disposed below the developing rail 103, extending in the insertion direction (longitudinal direction) along the developing rail 103. Pressure levers 104 and 105 are provided on both ends of the spacing link 102, on the rear side in the insertion direction (downstream side in the insertion direction) and on the front side in the insertion direction (upstream side in the insertion direction), respectively.

[0076] As shown in FIG. 11, the pressure levers 104 and 105 have fitting portions 104a and 105a that are formed so that the amount of vertical upward projection increases from the back side of the device body 100 toward the door 101 side.

[0077] 10, the developing rail 103 has mating portions 103a and 103b that can be engaged with mating portions 104a and 105a of the pressure levers 104 and 105, respectively. The door 101 is fastened to the separation link 102 via a link portion 101b.

[0078] Furthermore, in the second embodiment, a stopper mechanism 160' is provided, which includes a stopper member 160'a that restricts the closing operation of the door 101, and a first biasing spring 160'b that serves as a biasing portion that biases the stopper member 160'a. Also, in the second embodiment, the stopper mechanism 160 includes a rotation shaft 160'c that supports the stopper mechanism 160 rotatably with respect to the apparatus body 100, and a second biasing spring 160'd that serves as a biasing member that biases the stopper mechanism 160' around the rotation shaft.

[0079] The operation of the pressure mechanism of the developing unit 10 linked to the opening and closing operation of the door 101 will be described below with reference to FIGS.

[0080] The door 101 is provided at the insertion port (not shown) of the device main body 100 so as to be rotatable around a rotation axis 101a as the rotation center, and can rotate between a closed position that covers the upstream end of the development unit 10 in the insertion direction and an open position that exposes the upstream end of the development unit 10 in the insertion direction.

[0081] The separating link 102 moves to the front side in the insertion direction (second position) as the door 101 is opened, and moves to the rear side in the insertion direction (first position) as the door 101 is closed.

[0082] First, in the open state of the door 101 shown in FIG. 12(a), the fitting portions 104a and 105a and the fitted portions 103a and 103b are fitted to each other.

[0083] When the engaging portions 104a, 105a and the mating portions 103a, 103b are engaged with each other, the developing rail 103 is lowered vertically downward in the figure (toward the installation surface of the image forming device 1) so as to be closer to the separation link 102 than when the developing rail 103 is not engaged.

[0084] That is, when the door 101 is opened from a closed state (closed state), the link portion 101b moves forward in the insertion direction (see arrow F in the figure), and accordingly the separating link 102 also moves to the second position, which is forward in the insertion direction. When the separating link 102 moves to the second position, the mated portions 103a and 103b slide down along the mating portions 104a and 105a, and the mating portions 104a and 105a and the mated portions 103a and 103b fit together.

[0085] In this way, the developing rail 103 moves downward in the vertical direction in the figure (in the direction of arrow D in the figure), thereby separating the developing unit 10 from the photosensitive unit 20. In this case, the bearings 13a and 13b of the developing sleeve 11 and the bearings 25a and 25b of the photosensitive drum 21 are not in contact with each other.

[0086] 12(b), the engaging portion 104a (engaging portion 105a, not shown) and the engaged portion 103a (engaging portion 103b, not shown) are in a disengaged state. When the engaging portions 104a, 105a and the engaged portions 103a, 103b are in a disengaged state, the developing rail 103 is pushed up vertically upward in the drawing (toward the opposite side from the installation surface of the image forming apparatus 1) so as to move away from the separating link 102.

[0087] That is, when the door 101 is opened, the link portion 101b moves to the rear in the insertion direction, and the separating link 102 similarly moves to the first position, which is the rear in the insertion direction. Then, with the developing unit 10 and the photosensitive unit 20 attached to the apparatus main body 100, the developing unit 10 is pressed against the photosensitive unit 20. In this case, the bearings 13a and 13b of the developing sleeve 11 abut against the bearings 25a and 25b of the photosensitive drum 21, and the developing unit 10 is positioned with the SD gap ensured.

[0088] In this way, as the developing rail 103 moves up and down in the vertical direction in conjunction with the opening and closing of the door 101 , the developing unit 10 presses against and separates from the photosensitive unit 20 .

[0089] Now, consider a case where the developing unit 10 is attached to the apparatus main body 100 and the photosensitive unit 20 is not attached to the apparatus main body 100. In this case, it becomes necessary to consider the possibility that a user or a service person may close the door 101.

[0090] This is because, although the developing unit 10 is pressed by the separation link 102 moving to the first position in conjunction with the closing operation of the door 101, the photosensitive unit 20 is not yet attached to the apparatus main body 100. As a result, the developing unit 10 is not positioned properly, which may result in an unstable state.

[0091] If a user or service person unknowingly attempts to move the image forming device 1 while the developing unit 10 is not positioned relative to the photosensitive unit 20 in this manner, there is a risk that the developing unit 10 will vibrate and collide with a nearby unit within the device main body 100.

[0092] Therefore, in the second embodiment, as shown in Figure 11, when the photosensitive unit 20, which positions and urges the development unit 10, is not attached to the device main body 100, the regulating portion 101d of the door 101 abuts against the stopper member 160'a, thereby regulating the closing operation of the door 101.

[0093] This makes it possible to prevent the door from being closed in a state where the photosensitive unit 20, to which the developing unit 10 is to be positioned, is not attached to the apparatus main body 100 and the developing unit 10 is being pressed. Also, it is possible to prevent the image forming apparatus 1 from being moved as much as possible with the developing unit 10 not being positioned relative to the photosensitive unit 20 and with the developing unit 10 in an unstable position.

[0094] Furthermore, when the photosensitive unit 20 is attached to the apparatus main body 100, the stopper member 160'a is pressed against the spring 160'b, as in the first embodiment. That is, when the photosensitive unit 20 is attached to the apparatus main body 100, the stopper member 160'a is pressed by the photosensitive unit 20, and the door 101 can be closed.

[0095] That is, when the developing unit 10 and the photosensitive unit 20 are both attached to the apparatus main body 100, a user or a service person closes the door 101. As a result, the separating link 102 moves to the first position, and the developing unit 10 is pressed against the photosensitive unit 20, as shown in FIG.

[0096] In this case, the bearings 13a and 13b of the developing sleeve 11 abut against the bearings 25a and 25b of the photosensitive drum 21, and the developing unit 10 is positioned with the SD gap guaranteed. As a result, the door 101 is closed with the developing unit 10 properly positioned, preventing the developing unit 10 from colliding with adjacent units.

[0097] Here, a case where the developing unit 10 is detachable from the apparatus main body 100 and neither the developing unit 10 nor the photosensitive unit 20 is attached to the apparatus main body 100 will be described.

[0098] The stopper mechanism 160' in the second embodiment is rotatable around a rotation axis 160'c. Therefore, when the developing unit 10 is not attached to the apparatus main body 100, the stopper mechanism 160' is rotated by the second biasing spring 160'd as shown in Figure 13. As a result, the restricting portion 101d of the door 101 does not come into contact with the stopper member 160'a, and therefore the operation of closing the door 101 is not restricted.

[0099] In the first embodiment described above, the stopper member 160a is biased so that the position of the stopper member 160a is the restricting position when the photosensitive unit 20 is not attached to the apparatus main body 100 and the developing unit 10 is not attached to the apparatus main body 100. The restricting position is a position where the pressure applying portion (the handle 150 in the first embodiment) that applies pressure to the developing unit 10 is restricted from moving from the second position where the pressure on the developing unit 10 is released to the first position where the developing unit 10 is pressed toward the photosensitive unit 20.

[0100] In contrast to this, in the second embodiment, the stopper member 160'a is biased so that the position of the stopper member 160'a is a retracted position retracted from the restricting position when neither the photosensitive unit 20 nor the developing unit 10 is attached to the apparatus main body 100. The retracted position is a position where the pressure applying portion (pressure applying lever 104 in the second embodiment) that applies pressure to the developing unit 10 does not restrict movement from the second position where the pressure on the developing unit 10 is released to the first position where the developing unit 10 is pressed toward the photosensitive unit 20.

[0101] Therefore, in the second embodiment, even when the photosensitive unit 20 is not attached to the apparatus main body 100 and the developing unit 10 is not attached to the apparatus main body 100, a user or a service person can close the door 101. If neither the developing unit 10 nor the photosensitive unit 20 is attached to the apparatus main body 100, there is no risk of the units colliding with each other even if the image forming apparatus 1 is moved with the door 101 closed.

[0102] On the other hand, as described above, when the developing unit 10 is attached to the apparatus main body 100, the stopper mechanism 160' is pressed by the developing unit 10 and rotates around the rotation axis 160'c to the position shown in Fig. 11. The subsequent action and effect of the stopper mechanism 160' is the same as that described in the first embodiment.

[0103] In the second embodiment, the configuration in which the separating link 102 moves in conjunction with the opening and closing operation of the door 101 has been described as an example, but the present invention is not limited to this. As in the first embodiment described above, the door 101 may be configured to rotate in response to the opening and closing operation of the door 101, and the pressing mechanism may move in conjunction with the rotation of the door 101.

[0104] (Other embodiments) The present invention is not limited to the above-described embodiments, and various modifications (including organic combinations of the respective embodiments) are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0105] In the above embodiment, the photosensitive unit 20 is insertable into and removable from the apparatus main body 100, and the developing unit 10 is moved toward and away from the photosensitive unit 20. However, the present invention is not limited to this. For example, the developing unit 10 may be insertable into and removable from the apparatus main body 100, and the photosensitive unit 20 may be moved toward and away from the developing unit 10.

[0106] 1, the image forming apparatus 1 performs primary transfer of the toner image carried on the photosensitive drum 21 onto the intermediate transfer belt 30. Thereafter, the image forming apparatus 1 brings the recording material S into contact with the intermediate transfer belt 30 and performs secondary transfer of the toner image carried on the intermediate transfer belt 30 onto the recording material S. In the above embodiment, the image forming apparatus 1 configured as described above has been described as an example, but the present invention is not limited to this. The present invention can also be applied to an image forming apparatus configured to bring the recording material S into direct contact with the photosensitive drum 21 and directly transfer the toner image carried on the photosensitive drum 21 onto the recording material S. [Explanation of symbols]

[0107] 1. Image forming device 10 Development unit 20 Photoconductor unit 100 Mounting body 150b pressure spring 150c pressure section 150d Regulation Department 160 Stopper mechanism 160a Stopper member 160b biasing spring

Claims

1. A device body, a photosensitive unit having a photosensitive member on which an electrostatic latent image is formed, the photosensitive unit being detachable from the device main body and positioned relative to the device main body; a developing unit detachable from the apparatus main body, the developing unit having a developer carrier that carries and transports developer to develop an electrostatic latent image formed on the photosensitive member, the developing unit being positioned relative to the photosensitive member unit attached to the apparatus main body; a pressure applying section movable between a first position where the developing unit is pressed against the photosensitive unit and a second position where the developing unit is released from the pressure; a restricting portion movable between a restricting position that restricts movement of the pressure applying portion from the second position to the first position and a retracted position that is retracted from the restricting position so as not to restrict movement of the pressure applying portion from the second position to the first position; a biasing portion that biases the regulating portion so that the regulating portion is positioned at the retracted position when the photosensitive unit is attached to the device main body and the developing unit is attached to the device main body, biases the regulating portion so that the regulating portion is positioned at the retracted position when the photosensitive unit is attached to the device main body and the developing unit is not attached to the device main body, and biases the regulating portion so that the regulating portion is positioned at the regulating position when the photosensitive unit is not attached to the device main body and the developing unit is attached to the device main body; An image forming apparatus comprising:

2. When the photosensitive unit is not attached to the apparatus main body and the developing unit is not attached to the apparatus main body, the urging portion urges the regulating portion so that the regulating portion is positioned at the regulating position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. When the photosensitive unit is not attached to the apparatus main body and the developing unit is not attached to the apparatus main body, the urging portion urges the regulating portion so that the regulating portion is positioned at the retracted position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. a door that is rotatably provided with respect to the device body and that is movable between a closed position that covers the developing unit attached to the device body and an open position that exposes the developing unit attached to the device body, As the door moves from the open position to the closed position due to the rotation of the door, the pressing unit moves from the second position to the first position, As the door moves from the closed position to the open position due to the rotation of the door, the pressure unit moves from the first position to the second position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images