Image forming apparatus

Abstract

The present invention provides an image forming apparatus. The image forming apparatus includes: a photoreceptor unit having a photoreceptor; a developing apparatus having a developing roller; a spacing holding unit disposed on the photoreceptor unit or the developing apparatus, the spacing holding unit abutting a portion against a portion of the developing apparatus or the photoreceptor unit to maintain a spacing between the developing roller and the photoreceptor; a pressing unit pressing the developing apparatus toward the photoreceptor unit; and a connecting unit fixing and connecting the photoreceptor unit and the developing apparatus with a detachable fixing unit.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an image forming apparatus. BACKGROUND

[0002] Conventionally, as an image forming apparatus, for example, an image forming apparatus described in Japanese Patent Application Publication No. 2016-206607 (paragraphs 0072-0073, Figures 1 to 6 and the like) is known.

[0003] In Japanese Patent Application Publication No. 2016-206607 (paragraphs 0072-0073, Figures 1 to 6 and the like), an image forming apparatus is described in which a convex portion of a developing device is pressed by a load of a spring member, and the developing device is pressed by an image holder (a photosensitive body) by being rotated in a direction of the image holder with a positioning shaft as a center. SUMMARY

[0004] The present disclosure provides an image forming apparatus that is capable of suppressing variation in a gap between a developing roller and a photosensitive body due to vibration, as compared to a case in which a developing device and a photosensitive body unit are not linked by a link member that is detachably fixed.

[0005] According to a first aspect of the present disclosure, there is provided an image forming apparatus including: a photosensitive body unit having a photosensitive body; a developing device having a developing roller; a gap maintaining unit provided to the photosensitive body unit or the developing device, the gap maintaining unit maintaining a gap between the developing roller and the photosensitive body by abutting a portion thereof against a portion of the developing device or the photosensitive body unit; a pressing unit that presses the developing device toward the photosensitive body unit; and a linking unit that links the photosensitive body unit and the developing device with a fixing unit that is detachable.

[0006] According to a second aspect of the present disclosure, a direction in which the fixing unit fixes the linking unit and a pressing direction of the pressing unit cross each other.

[0007] According to a third aspect of the present disclosure, a direction in which the fixing unit fixes the linking unit and an axial direction of the photosensitive body cross each other.

[0008] According to a fourth aspect of the present disclosure, one end portion of the linking unit is rotatably attached to the developing device, and the other end portion is fixed to a fixed portion of the photosensitive body unit by the fixing unit.

[0009] According to a fifth aspect of the present disclosure, the link unit is configured in a manner that a mounting hole provided at one end portion thereof is rotatably mounted on a mounting shaft provided to the developing device, the mounting hole being configured by a long hole that is displaceable in a direction in which an inclined state when the link unit is fixed is released.

[0010] According to a sixth aspect of the present disclosure, a length direction of the long hole of the link unit is parallel to a direction in which the fixing unit is fixed.

[0011] According to a seventh aspect of the present disclosure, the fixed portion is a support unit that supports a shaft portion of the photosensitive body.

[0012] According to an eighth aspect of the present disclosure, the fixing unit is a fitting unit that fits a protrusion and a fitting hole, the fitting hole or the protrusion being present at a position that is capable of being fitted with the protrusion or the fitting hole when the developing device is pressed toward the photosensitive body unit by the pressing unit.

[0013] According to a ninth aspect of the present disclosure, the interval maintaining unit has an adjustment unit that adjusts an interval.

[0014] According to a tenth aspect of the present disclosure, there is provided an image forming apparatus having a moving support unit that supports the developing device to be movable in a direction away from the photosensitive body unit, the link unit being in a state in which a line that links a center of a portion mounted to the developing device and a center of a portion fixed to the fixed portion is parallel to a direction in which the developing device is moved by the moving support unit.

[0015] According to an eleventh aspect of the present disclosure, the link unit links between left and right end portions in a length direction of the photosensitive body unit and left and right end portions in a length direction of the developing device, respectively.

[0016] According to a twelfth aspect of the present disclosure, there is provided an image forming apparatus including a photosensitive body unit having a photosensitive body, a frame that holds the photosensitive body unit, a developing device having a developing roller, an interval maintaining unit provided to the photosensitive body unit or the developing device, the interval maintaining unit maintaining an interval between the developing roller and the photosensitive body with a portion in contact with a portion of the photosensitive body unit or the developing device, a pressing unit that presses the developing device toward the photosensitive body unit, and a link unit that fixes and links the frame and the developing device with a detachable fixing unit.

[0017] Effects of Invention

[0018] According to the first or twelfth aspect, compared with a case where the developing device and the photoreceptor unit or the developing device and the frame are not linked by the link member which is detachably fixed, it is possible to suppress variation in the interval between the developing roller and the photoreceptor due to vibration.

[0019] According to the second aspect, compared with a case where the fixing unit is adopted which is not crossed with the pressing direction of the pressing unit in the direction in which the fixing link unit is fixed, it is possible to keep the interval between the developing roller and the photoreceptor which is kept by the interval keeping unit from varying due to the fixing of the fixing unit.

[0020] According to the third aspect, compared with a case where the fixing unit is adopted which is parallel with the axial direction of the photoreceptor unit in the direction in which the fixing link unit is fixed, it is possible to suppress vibration in the direction perpendicular to the axial direction of the photoreceptor when the photoreceptor rotates or vibration in the direction perpendicular to the axial direction of the developing roller when the developing roller rotates.

[0021] According to the fourth aspect, compared with a case where the link unit is not adopted which has one end portion rotatably mounted to the developing device and the other end portion fixed to the fixed portion of the photoreceptor unit by the fixing unit, it is possible to fix the other end portion of the link unit to the fixed portion of the photoreceptor unit while adjusting by rotation.

[0022] According to the fifth aspect, compared with a case where the mounting hole provided to the one end portion of the link unit is not constituted by a long hole which can be displaced in the direction in which the link unit is released from the fixed state, it is possible to suppress the state of being inclined to the fixed portion of the photoreceptor unit or the state of being deformed when the link unit is fixed.

[0023] According to the sixth aspect, compared with a case where the length direction of the long hole of the link unit is not parallel with the direction in which the fixing unit is fixed, it is possible to fix the link unit between the long hole and the portion fixed by the fixing unit in such a manner that the link unit does not become in a twisted state.

[0024] According to the seventh aspect, compared with a case where the fixed portion is not a support unit which supports the shaft portion of the photoreceptor, it is easy to perform the forming of the fixed portion or the fixing work of the link unit.

[0025] According to the eighth aspect, compared with a case where the protrusion and the fitting hole are not opposed when the developing device is pressed to the photoreceptor unit, it is possible to easily fix the link unit.

[0026] According to the ninth aspect, compared with a case where the interval keeping unit does not have the adjustment unit, it is possible to keep the interval between the developing roller and the photoreceptor with high precision.

[0027] According to the tenth aspect, even when the developing device is supported so as to be movable in a direction away from the photosensitive body unit, the variation in the interval between the developing roller of the developing device and the photosensitive body due to vibration can be suppressed.

[0028] According to the eleventh aspect, compared with a case where only the left and right end portions in the longitudinal direction of the developing device are connected to either one of the left and right end portions in the longitudinal direction of the photosensitive body unit via the connecting member, the variation in the interval between the developing roller and the photosensitive body due to vibration in the axial direction can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic diagram illustrating an image forming apparatus according to Embodiment 1.

[0030] Figure 2 is a schematic perspective view illustrating Figure 1 a photosensitive body unit, a developing device, and the like in the image forming apparatus of

[0031] Figure 3 is a schematic plan view illustrating Figure 2 a state when the photosensitive body unit and the developing device of

[0032] Figure 4 is a schematic side view illustrating Figure 3 a part of the connected state of

[0033] Figure 5 is a schematic sectional view along the line Q-Q of Figure 2 the developing device.

[0034] Figure 6 is a schematic plan view illustrating Figure 2 a state when the connection of the photosensitive body unit and the developing device of

[0035] Figure 7 is a schematic side view illustrating Figure 6 a part of the connection release state of

[0036] Figure 8 (A) of Figure 8 is a schematic perspective view of a connecting unit,

[0037] Figure 9 (A) of Figure 9 is a schematic diagram illustrating the structure of a connecting unit and a fixing unit,

[0038] Figure 10 is a schematic perspective view illustrating a state where the connecting unit is attached to the developing device.

[0039] Figure 11 is a schematic perspective view showing a part of a state in which the photoreceptor unit and the developing device are connected. DETAILED DESCRIPTION

[0040] Hereinafter, an embodiment for carrying out the present disclosure will be described with reference to the drawings.

[0041] Embodiment 1

[0042] Figures 1 to 4 is a view showing Embodiment 1 of the present disclosure. InEmbodiment 1 is shown in Figure 1 , and a photoreceptor unit and a developing device in the image forming apparatus 1 are shown in Figures 2 to 4

[0043] As shown in Figure 1 , the image forming apparatus 1 has, inside a housing 10, an image forming apparatus 2 that forms a toner image composed of toner as a developer by an electrophotographic method or the like, and transfers it onto recording paper 9 as an example of a recording material; a paper feeding device 3 that feeds a desired recording paper 9 accommodated to a transfer position of the image forming apparatus 2; and a fixing device 4 that fixes the toner image transferred onto the recording paper 9.

[0044] As shown in Figure 1 , the image forming apparatus 2 is configured to have, around a photoreceptor drum 21 as an example of a photoreceptor that rotates in a direction indicated by an arrow A, a charging device 22, an exposure device 23, a developing device 24, a transfer device 25, a cleaning device 26, and a discharge device 27, and the like, disposed in this order.

[0045] The photoreceptor drum 21 is a drum-shaped photoreceptor having a photosensitive layer on a peripheral surface, is supported by a support frame or the like so as to be rotatable, receives power from a drive device not shown, and is rotationally driven in the direction indicated by the arrow A. The charging device 22 causes the peripheral surface (image forming area) of the photoreceptor drum 21 to have a desired polarity and potential by using a charging member supplied with a charging bias.

[0046] The exposure device 23 exposes the charged peripheral surface of the photoreceptor drum 21 to light corresponding to image information (signal) input to the image forming apparatus 1 in various ways, thereby forming an electrostatic latent image. The developing device 24 supplies toner as a developer from a developing roller 57, thereby developing the electrostatic latent image on the photoreceptor drum 21 to form a toner image. Details of the developing device 24 will be described later.

[0047] The transfer device 25 electrostatically transfers the toner image on the photosensitive drum 21 to the recording sheet 9 by a transfer member supplied with a transfer bias. The cleaning device 26 removes and cleans the toner and the like adhering to the peripheral surface of the photosensitive drum 21. The discharge device 27 discharges the peripheral surface of the photosensitive drum 21 after cleaning.

[0048] The paper feeding device 3 is configured from a paper housing body 31 that houses a plurality of recording sheets 9 of sizes, types, and the like required for image formation in a stacked state, and a feeding device 33 that feeds the recording sheets 9 housed in the paper housing body 31 one by one.

[0049] The paper housing body 31 is installed so as to be able to be pulled out with respect to the housing 10, and is provided in a plurality according to the manner of use thereof. As the recording sheets 9, for example, recording media such as ordinary paper, coated paper, thick paper, and thin paper, and the like that are cut to a prescribed size are used.

[0050] The fixing device 4 is configured so as to have a fixing member such as a heating rotary body 41 and a pressurizing rotary body 42 of a form having a roller, a conveyance belt, and the like disposed in the inside of a housing 40 provided with an inlet and an outlet for the recording sheets 9.

[0051] The heating rotary body 41 and the pressurizing rotary body 42 are supported so as to rotate in contact with each other, to serve as a fixing processing portion that performs a required fixing process (heating, pressurization, and the like) while sandwiching and passing the recording sheet 9 on which an unfixed toner image is transferred with the portion in contact with each other.

[0052] Further, image formation by the image forming apparatus 1 is performed as follows. Here, the basic image formation operation when forming an image on one side of the recording sheet 9 is explained as an example.

[0053] In the image forming apparatus 1, if a request command (signal) of an image formation operation is received from an external connection device by an unillustrated control portion, in the image forming apparatus 2, the photosensitive drum 21 is rotated to start in the direction indicated by an arrow A, the charging device 22 charges the peripheral surface of the photosensitive drum 21 to a prescribed polarity and potential (in this example, a negative polarity), and thereafter, the exposure device 23 exposes the charged peripheral surface of the photosensitive drum 21 based on input image information, to form an electrostatic latent image composed of a required pattern.

[0054] Next, in the image forming apparatus 2, the developing device 24 supplies toner having a required polarity (in this example, a negative polarity) from a developing roller 57 to the electrostatic latent image formed on the peripheral surface of the photosensitive drum 21 and develops it, to visualize the electrostatic latent image. Thereby, a toner image is formed on the photosensitive drum 21.

[0055] Subsequently, in the image forming apparatus 2, the rotating photosensitive drum 21 transports the toner image to the transfer position opposite to the transfer apparatus 25.

[0056] On the other hand, in the paper feeding device 3, the recording paper 9 is fed out by the feeding device 33 to the supply conveying path composed of the conveying rollers 35 and 36, paper guiding components, etc., in order to catch up with the moment when the toner image formed by the image forming device 2 arrives at the transfer position. Finally, the recording paper 9 is fed into and supplied to the transfer position of the image forming device 2 by the conveying roller 36.

[0057] At this time, the image forming apparatus 2 causes the transfer member of the transfer device 25 to form a transfer electric field between itself and the photosensitive drum 21 at the transfer position, causing the toner image on the photosensitive drum 21 to be electrostatically transferred to one side of the recording paper 9. Furthermore, in the image forming apparatus 2, during the image forming operation, including the period after this transfer, the cleaning device 26 continuously cleans the peripheral surface of the photosensitive drum 21, and the static removal device 27 removes static electricity from the cleaned peripheral surface of the photosensitive drum 21. Thus, the photosensitive drum 21 is maintained in a state ready for the next image forming operation.

[0058] Next, the recording paper 9, with the toner image transferred onto it, is fed from the transfer position and transported to the fixing device 4. In the fixing device 4, the recording paper 9 is guided through a fixing processing section between a heating rotating body 41 and a pressure rotating body 42 driven by rotation. As it passes through this fixing processing section, the toner image on one side of the recording paper 9 is fixed onto the recording paper 9 by the melting of its toner under pressure.

[0059] Furthermore, in the fixing device 4, the recording paper 9 after fixing is sent from the fixing processing unit to the discharge conveying path composed of the discharge roller 37, paper guide members, etc. Finally, the fixed recording paper 9 is discharged from the discharge port 12 of the housing 10 through the discharge roller 37 in the discharge conveying path and is accommodated in the discharge receiving section (not shown).

[0060] Through the above steps, a monochrome image composed of a single color toner is formed on one side of a recording paper 9, thus completing the image formation operation on one side of the recording paper 9. Furthermore, when an instruction is issued to perform image formation operations on multiple sheets, the above series of operations is repeated in the same manner as the number of sheets.

[0061] Next, the photosensitive drum 21 and the developing device 24 in the image forming apparatus 1 will be further described.

[0062] like Figures 2 to 4 As shown, the photosensitive drum 21 has left and right shaft portions 21c protruding from both ends of its axial direction J.

[0063] The photosensitive drum 21 becomes a part of a photosensitive body unit 20 which is combined with the photosensitive drum 21 and other constituent members such as left and right shaft support portions 211A, 211B which are examples of support units that support the left and right shaft portions 21c of the photosensitive drum 21 so as to be rotatable, and becomes a unit.

[0064] The left and right shaft support portions 211A, 211B are provided with a recessed-shaped support groove 213 that supports the left and right shaft portions 21c of the photosensitive drum 21 in an embedded state, a positioning portion, a contact surface 214 and a fixed surface 215 described later, and the like.

[0065] Also, as shown in Figure 2 , the photosensitive body unit 20 is installed in a state where its position is fixed by the left and right shaft support portions 211A, 211B to pull-out frames 15A, 15B which are arranged to be able to be pulled out to the outside in the housing 10. The pull-out frames 15A, 15B are, for example, a pull-out moving body that is made three-dimensional by being linked by a plurality of link members 151 to 155 and the like, and is supported by a moving unit such as a moving guide rail not shown, and is arranged to be able to move with respect to the housing 10.

[0066] Incidentally, the photosensitive body unit 20 is held and installed in a state where the photosensitive drum 21 is positioned at a reference position E1 to the above-described pull-out moving body constituted by the pull-out frames 15A, 15B and the like. Also, a positioning pin 16 (refer to Figure 11 ) and the like is provided on the pull-out frames 15A, 15B and the like, and is used to be positioned by being embedded in a positioning hole provided on the side of the installation portion thereof when stored in the installation portion of the housing 10.

[0067] On the other hand, as shown in Figures 1 to 5 , the developing device 24 has a casing 50 that accommodates the developer 18, and is provided with a developing roller 57 and the like. As the developer 18, for example, a two-component developer that contains a non-magnetic toner and a magnetic carrier is used.

[0068] As shown in Figure 5 , the casing 50 is provided with two groove-shaped passages 53A, 53B as the accommodation portion 51, the two passages 53A, 53B extend in parallel along the length direction D Figure 3 and the like) thereof, and are connected to each other at both end portions in the length direction D.

[0069] The housing 50 has conveying components 54A and 54B, such as a spiral drill, arranged in the receiving part 51. The conveying components 54A and 54B rotate within their respective passages 53A and 53B, and convey the developer 18 while stirring along the length direction D. The passages 53A and 53B, except for the two ends along the length direction D, are divided by partition walls 55 extending along the length direction D.

[0070] In the passages 53A and 53B, when the conveying components 54A and 54B are rotated, the developer 18 is conveyed in opposite conveying directions in each passage 53A and 53B, and then its downstream end in each conveying direction is fed into the upstream end in the conveying direction of each passage 53A and 53B, thereby conveying the developer 18 in a cyclical manner as a whole.

[0071] And, as Figure 5 As shown, the housing 50 is aligned with the axial direction J( along the photosensitive drum 21) Figure 3 The developing opening 56 is provided on the part opposite to the developing object (etc.).

[0072] A developing roller 57 is disposed on the inner side of the housing 50, including the developing opening 56, and the developing roller 57 rotates while being exposed to the outside through its developing opening 56.

[0073] Inside the housing 50, near the developing opening 56, there is a supply component 58 and a plate-shaped layer thickness adjustment component 59. The supply component 58 is composed of blades, rollers, etc., and rotates to supply a portion of the developer 18 that is conveyed in the passage 53B by the conveying component 54B to the developing roller 57. The layer thickness adjustment component 59 adjusts the layer thickness of the developer held in the developing roller 57.

[0074] Moreover, such as Figure 3 As shown, the two ends of the aforementioned receiving portion 51 in the longitudinal direction D of the housing 50 are configured as left and right support portions 52A and 52B.

[0075] The left and right support portions 52A and 52B serve as two parts: portions supporting the two ends (including bearings, etc.) along the length direction D of the conveying components 54A and 54B, the developing roller 57, the supply component 58, and the layer thickness adjustment component 59; and portions for arranging and storing drive transmission mechanisms, etc. (not shown). Furthermore, a replenishment path is provided protruding from the left support portion 52A, the replenishment path having a receiving port 521 for introducing the replenished developer (toner, etc.).

[0076] And, as Figures 2 to 4As shown, in the left and right support portions 52A and 52B, for the purpose of accommodating the movable support unit 63 described later, left and right support plates 60A and 60B are installed on each of their outer surfaces, protruding upwards toward the housing 50. On the other hand, left and right lower protrusions 522 are provided at each of their lower ends, which are shaped to protrude downwards toward the housing 50. Regarding the lower protrusions 522, instead of being provided in the support portions 52A and 52B, they may also be composed of support plates installed on each of the outer surfaces of the support portions 52A and 52B.

[0077] like Figure 5 As shown, the developing roller 57 is, for example, a roller consisting of a cylindrical (non-magnetic) sleeve 57a that rotates in the direction indicated by arrow B and a magnetic roller 57b disposed within the hollow of the sleeve 57a. The shaft portion 57c of the developing roller 57 is supported by bearings.

[0078] And, as Figure 3 , Figure 4 As shown, by configuring the developing roller 57 such that the contact portion 62 contacts the shaft support portions 211A and 211B of the shaft portion 21c supporting the photosensitive drum 21 at each contact surface 214 (see reference). Figure 3 , Figure 4 In a state of contact (e.g.), the distance S between the developing roller 57 and the photosensitive drum 21 remains fixed, and the contact portion 62 becomes part of the spacing holding member 61, which is an example of the spacing holding unit mounted on the shaft portion 57c of the developing roller 57. Furthermore, as... Figure 4 or Figure 7 As shown, the interval holding member 61 has an adjustment unit 612 for adjusting the interval S. The adjustment unit 612 is adapted to be a sheet-like interval member of a predetermined thickness, and the protruding position of the contact portion 62 (the distance between it and the shaft portion 57c) can be slightly changed by installing the interval member on its mounting portion or removing it from its mounting portion.

[0079] Furthermore, when the designated period for image formation operations is reached, a developing bias voltage is supplied to the shaft portion 57c of the developing roller 57 by a power supply unit not shown in the figure, thereby forming a developing electric field between the developing roller 57 and the photosensitive drum 21.

[0080] And, as Figures 2 to 4 , Figure 6 , Figure 7 As shown, the developing apparatus 24 is supported by the movable support unit 63 so that it can move in the direction C that separates from the photosensitive drum 21 of the photosensitive unit 20.

[0081] like Figure 4As shown, the movable support unit 63 is composed of the following components: rotatable upper and lower rollers 631 and 632, which are provided on the left and right end sides in the length direction D of the housing 50; and upper and lower guide rails 635 and 636, which are provided on the pull-out frames 15A and 15B, to guide the upper and lower rollers 631 and 632 in the separation direction indicated by arrow C and make them move (roll).

[0082] For example, such as Figure 4 As shown, the upper roller 631 is mounted rotatably at both ends of the upper support shaft 633, which is fixed to the left and right support plates 60A and 60B in the housing 50 in a manner that extends through the shaft along the length direction D and protrudes a predetermined amount to each of its outer sides. Furthermore, for example, as... Figure 4 As shown, the lower roller 632 is mounted on the lower support shaft 634 so as to be rotatable, and the lower support shaft 634 is fixed to the aforementioned left and right lower protrusions 522 in the housing 50 in a manner that passes through and protrudes outward by a predetermined amount.

[0083] On the other hand, the upper and lower guide rails 635 and 636 are composed of a track section that guides the upper and lower rollers 631 and 632 to roll in the separation direction C. This separation direction C is, for example, set to a horizontal direction (a direction that is approximately parallel to the ground on which the image forming apparatus 1 is installed).

[0084] like Figure 2 As shown, the developing apparatus 24 is supported by the movable support unit 63 and is mounted on the aforementioned pull-out movable body composed of pull-out frames 15A, 15B, etc. by means of the movable support unit 63.

[0085] Thus, when the pull-out movable body is pulled out from the housing 10, the developing device 24 can be pulled out to the outside of the housing 10 together with the pull-out movable body.

[0086] And, as Figure 6 , Figure 7 As shown, the developing apparatus 24 can also be in the following state: as the upper and lower rollers 631 and 632 in the movable support unit 63 roll and move on the upper and lower guide rails 635 and 636 respectively, it moves in the direction of arrow C in the pull-out movable body and separates from the photosensitive drum 21 of the photosensitive unit 20.

[0087] Moreover, such as Figures 2 to 4 As shown, the developing device 24 is pressed onto the photosensitive unit 20 (photosensitive drum 21) by the pressing unit 65.

[0088] In Embodiment 1, the pressing unit 65 is pressurized with a required pressure F by a pressing member and the pressure-bearing plates 64 of the left and right support plates 60A and 60B provided in the housing 50. The pressing member is pushed out by a pressure spring of the connecting member 151 provided in the pull-out frames 15A and 15B. Furthermore, the pressing unit 65 is mounted on a mounting plate 66 that hangs down from both ends of the connecting member 151 in such a manner that the pressing member can contact the pressure-bearing plate 64. Figure 11 As shown, the mounting plate 66 is fixed to both ends of the connecting member 151 by means of screws 68 and other fixing methods, and the mounting plate 66 is set at a predetermined distance in the pressure bearing plate 64 on the side opposite to the photosensitive drum 21.

[0089] And, as Figure 4 As shown, the pressing direction P of the pressing unit 65 is, for example, set to the opposite direction parallel to the direction C in which the developing device 24 is separated by the moving support unit 63.

[0090] like Figure 3 or Figure 4 As shown, the developing device 24 is held in the following state by the pressing unit 65: its pressure bearing plate 64 receives pressure F along the pressing direction P from the pressing unit 65, thereby being pressed against the photosensitive unit 20.

[0091] As a result, the contact portion 62 of the spacer holding member 61 in the developing roller 57 of the developing apparatus 24 is pressed against the contact surfaces 214 in the shaft support portions 211A and 211B by a force based on pressure F. Consequently, as... Figure 3 or Figure 5 As shown, the gap S between the developing roller 57 and the photosensitive drum 21 of the developing apparatus 24 is maintained at the desired distance set by the gap holding member 61.

[0092] Moreover, such as Figures 2 to 4 As shown, in this image forming apparatus 1, the photoreceptor unit 20 and the developing apparatus 24 are connected by a connecting unit 7 that is detachably fixed.

[0093] In implementation method 1, such as Figure 3 As shown, the left and right ends of the photosensitive unit 20 along the length direction D (in the direction along the axial direction J of the photosensitive drum 21) are connected to the left and right ends of the developing device 24 along the length direction D by two connecting units 7A and 7B, respectively.

[0094] like Figures 2 to 4 , Figure 8As shown, the two connecting units 7A and 7B are both constructed as follows: they are composed of a plate-shaped component 70 that is longer in one direction. One end 70a in the length direction is mounted on the developing apparatus 24 so that it can rotate, and the other end 70b is fixed to the fixed part 20h of the photoreceptor unit 20 by a detachable fixing unit 8.

[0095] The component 70 constituting the connecting units 7A and 7B is made of a material with strength capable of maintaining the connection between the photoreceptor unit 20 and the developing apparatus 24.

[0096] like Figure 8 As shown, a mounting hole 72 is provided at one end 70a of the component 70 connecting units 7A and 7B, the mounting hole 72 being used for rotatably mounting to the mounting shaft 67 provided in the developing apparatus 24.

[0097] The mounting shaft 67 is provided in the left and right support plates 60A and 60B of the developing apparatus 24 as a shaft protruding outward in a generally horizontal direction along a predetermined length. Furthermore, the mounting shaft 67 can be a cylindrical component, for example, a bolt, as long as at least the part into which the mounting hole 72 is inserted is cylindrical.

[0098] like Figure 8 As shown in (A), the mounting hole 72 is configured as a through hole extending in a direction substantially perpendicular to the length direction of the plate-shaped component 70 and substantially parallel to the plate surface. The mounting hole 72 becomes a through hole extending in a substantially horizontal direction when mounted on the mounting shaft 67.

[0099] And, as Figure 8 As shown in (B), the mounting hole 72 is configured as an elongated hole. The length direction M of this elongated hole 72 only needs to be in the direction that allows for displacement when fixing the connecting units 7A and 7B, preventing unnecessary tilting between them and the fixed portion 20h of the photosensitive unit 20 (see reference). Figure 9 (B)

[0100] In Embodiment 1, the length direction M of the elongated hole 72 is set to be approximately perpendicular to the length direction of the component 70 connecting units 7A and 7B. Therefore, the mounting hole 72 in Embodiment 1 is generally formed as an elongated hole that is relatively long in the longitudinal direction.

[0101] Specifically, the mounting hole 72 is configured as an elongated hole with the following dimensions: the transverse diameter La along the length direction of the component 70 is set to be approximately the same as the diameter d of the circular cross-section of the mounting portion in the mounting shaft 67; on the other hand, the longitudinal diameter Lb along the direction approximately perpendicular to the length direction of the component 70 is set to be a length that is longer than the aforementioned diameter d of the mounting shaft 67 by a required amount.

[0102] Since the longitudinal diameter Lb of the elongated hole, which is the longer diameter, may cause instability in the mounting state due to unnecessarily allowing displacement of the mounting hole 72 relative to the mounting shaft 67, it must be a minimum necessary length compared to the diameter d of the mounting shaft 67. In this case, the longer diameter Lb is, for example, a length of approximately 0.5 mm to 5 mm compared to the diameter d of the mounting shaft 67.

[0103] The fixing unit 8 is a unit that makes the disassembly operation after fixing easier. For example, a fitting unit is used to allow the protrusion 81 to be detachably fitted into the fitting hole 82.

[0104] In Embodiment 1, the fixing unit 8, which is composed of a fitting unit, utilizes a combination of a screw as a protrusion 81 and a threaded hole of the screw as a fastening protrusion 81, which serves as a fitting hole 82. The fixing unit 8 can be a fitting unit consisting of a single set of protrusions 81 and fitting holes 82, but from the viewpoint of stable fixing, it is preferable to use a fitting unit consisting of multiple sets of protrusions 81 and fitting holes 82. In Embodiment 1, for example, a fitting unit consisting of two sets of protrusions 81 (screws) and fitting holes 82 (threaded holes) is used.

[0105] like Figure 8 , Figure 10 As shown, since the fixing unit 8 is a fixing unit consisting of two sets of screws and threaded holes, two through holes 73 are provided at the other end 70b of the component 70 connecting the units 7A and 7B, so that the two screws of the protrusion 81 can pass through.

[0106] The two through holes 73 are spaced apart in a direction perpendicular to the length direction of the component 70, but this configuration is not limited to this method. The other end 70b becomes the end of a plate used in a generally horizontal state, but because the two through holes 73 are spaced apart in the aforementioned direction, it adopts a shape in which its width is larger than the width of the main body (see reference). Figure 10 ).

[0107] like Figures 2 to 4 As shown, the fixed portion 20h of the photoreceptor unit 20, to which the connecting units 7A and 7B are detachably fixed, adopts left and right shaft support portions 211A and 211B, which are composed of a fixed surface 215 formed on a part of the shaft support portions 211A and 211B.

[0108] like Figure 2 , Figure 4As shown, the fixed surface 215 is formed on the upper surface of a portion located at approximately the same height as the center position of the mounting shaft 67 provided on the developing apparatus 24 side. Furthermore, from the viewpoint that the fixed surface 215 and the planar lower surface of the other end 70b of the connecting units 7A and 7B are well joined, the fixed surface 215 is configured as a smooth planar surface.

[0109] Furthermore, two threaded holes serving as fitting holes 82 for fixing unit 8 are provided on the fixed surface 215 of the fixed part 20h. The two threaded holes are formed in a position that matches the two through holes 73 provided at the other end 70b of the connecting units 7A and 7B.

[0110] like Figure 9 As shown, the fixing unit 8 is set in such a way that the direction K of the fixing connecting units 7A and 7B intersects with the pressing direction P of the pressing unit 65.

[0111] The crossing angle is preferably a right angle or as close to a right angle as possible. Furthermore, this perpendicularity indicates that the crossing angle is, for example, within the range of 90° ± 5°.

[0112] In embodiment 1, the orientation of the threaded hole is set such that the direction of travel of the screw, which forms the protrusion 81, when it is fastened in the threaded hole of the fitting hole 82 intersects (preferably perpendicularly) the pressing direction P. For example... Figure 9 As shown in (A), the threaded hole of the fitting hole 82 is actually set as a hole extending in a direction that is substantially perpendicular to the fixed surface 215 of the fixed part 20h.

[0113] And, as Figure 9 As shown in (B), the direction K in which the fixing unit 8 is fixed in Embodiment 1 intersects (preferably perpendicularly) with the length direction of the component 70 when the connecting units 7A and 7B are fixed.

[0114] Moreover, such as Figure 9 As shown in (B), in embodiment 1, the length direction M of the elongated hole configured as mounting hole 72 in the connecting units 7A and 7B is parallel to the direction K of the fixing connecting units 7A and 7B of the fixing unit 8.

[0115] And, as Figure 9 As shown in (B), the connecting units 7A and 7B in Embodiment 1 are configured such that the imaginary line VL is parallel to the direction C that moves away through the movable support unit 63. The imaginary line VL connects the center Oa of the part (mounting shaft 67) installed on the developing apparatus 24 with the center Ob of the part (other end 70b) fixed to the fixed part 20h.

[0116] like Figure 10As shown, the connecting units 7A and 7B described above, for example, after inserting the mounting hole 72 of one end 70a into and mounting it onto the mounting shaft 67 located at both ends of the developing apparatus 24 in the longitudinal direction D, leave the other end 70b in a free state and pre-install it on the developing apparatus 24 so that it can be easily used when connection is required.

[0117] In this case, a fixing component, such as an E-ring (not shown), is installed on one or both sides of the mounting portion of the mounting shaft 67, in which the mounting holes 72 of the connecting units 7A and 7B are embedded. This maintains the mounting positions of the connecting units 7A and 7B relative to the mounting shaft 67 and prevents them from falling off.

[0118] Furthermore, since the connecting units 7A and 7B can rotate relative to the mounting shaft 67 at this time, therefore... Figure 9 As shown, the connecting units 7A and 7B can be swung up and down in the directions indicated by arrow N, with the mounting shaft 67 as the fulcrum. Therefore, the connecting units 7A and 7B actually vary depending on the ease of rotation, but when not in use, their other end 70b is sometimes positioned slightly downwards. On the other hand, the connecting units 7A and 7B can be swung arbitrarily in the up and down directions with the mounting shaft 67 as the fulcrum to adjust their posture.

[0119] Furthermore, since the mounting hole 72 is an elongated hole, the connecting units 7A and 7B can be slightly shifted in both directions along the length M of the elongated hole. Thus, the position can be adjusted by shifting the connecting units 7A and 7B along the length M of the elongated hole.

[0120] Furthermore, the photosensitive unit 20 and the developing apparatus 24 are connected using the connecting units 7A and 7B as follows.

[0121] First, after setting the developing apparatus 24, supported by the aforementioned movable support unit 63, close to the photoreceptor unit 20, the other ends 70b of the connecting units 7A and 7B of the mounting shafts 67 installed at both ends in the longitudinal direction D of the developing apparatus 24 are placed on the fixing surface 215 of the fixing portion 20h of the photoreceptor unit 20 (see reference). Figure 9 (A)).

[0122] Here, regardless of whether the photosensitive unit 20 is connected to the developing apparatus 24, it is mounted on the aforementioned pull-out movable body (see above) consisting of pull-out frames 15A, 15B, etc., with the photosensitive drum 21 positioned at the reference position E1. Figure 4 or Figure 7 ).

[0123] And, as Figure 11As shown, when the developing device 24 is positioned close to the photosensitive unit 20, it is pressed in the pressing direction P by the pressing unit 65 with a predetermined pressure F.

[0124] Furthermore, the connection operation is performed while the aforementioned pull-out movable body, which is equipped with the photosensitive unit 20, the developing device 24, etc., is pulled out of the housing 10 to the outside.

[0125] As mentioned above, since the fixed surface 215 is located at approximately the same height as the center of the mounting shaft 67, as long as the fixed surface 215 is a horizontal plane, the longer plate-shaped component 70 of the connecting units 7A and 7B in one direction will also be approximately horizontal. In the event that the connecting units 7A and 7B are tilted due to a height difference between the fixed surface 215 and the center of the mounting shaft 67 caused by tolerances or individual differences, the tilting of the connecting units 7A and 7B can be relieved by shifting one end of the connecting units 7A and 7B relative to the mounting shaft 67 along the length M of the elongated hole of the mounting hole 72.

[0126] Furthermore, at this time, the connecting units 7A and B are in a state where the through holes 73 of the two screws located at their other ends 70b are approximately opposite to the two threaded holes of the fixing surface 215 of the fixing part 20h, which serve as the fitting holes 82 of the fixing unit 8 (see reference). Figure 9 (A)) thus becomes a state in which a threaded fixation can be achieved, which is equivalent to the screw of the protrusion 81 of the fixing unit 8 being inserted into the threaded hole of the fitting hole 82. At this time, the developing device 24 is in a state where it is pressed against the photosensitive unit 20 by the pressing unit 65 as described above.

[0127] Therefore, the screw of the protrusion 81 of the fixing unit 8 can be easily tightened into the threaded hole of the fitting hole 82. As a result, when the developing device 24 is pressed against the photosensitive unit 20, the connecting units 7A and 7B are easily fixed to the fixed part 20h by the fixing unit 8.

[0128] Next, after the two screws of the protrusion 81, which serve as the fixing unit 8, pass through the two through holes 73 in the connecting units 7A and 7B, they are respectively inserted into and fastened into the two threaded holes 82, which serve as fitting holes, located on the fixing surface 215.

[0129] Therefore, as Figure 9 As shown in (B), the other end 70b of the connecting units 7A and 7B is fixed to the fixed surface 215 of the photosensitive unit 20 by the fixing unit 8.

[0130] By performing the above tasks, such as Figures 2 to 4As shown, the developing apparatus 2 and the photosensitive unit 20 are connected via connecting units 7A and 7B. This connection is easily achieved by tightening screws into the connecting units 7A and 7B using the protrusions 81 that serve as fixing units 8.

[0131] The connected developing apparatus 24 is in a state where it is pressed against the photosensitive unit 20 by the pressing unit 65 with the required pressure F, and in the state where it is subjected to the pressure F, the contact portion 62 of the spacer holding member 61 is pressed against the contact surfaces 214 on the shaft support portions 211A and 211B. As a result, in the developing apparatus 24, during the stage of completing the connection via the connecting units 7A and 7B, the gap S between the developing roller 57 and the photosensitive drum 21 is maintained at the desired distance set by the spacer holding member 61.

[0132] Furthermore, since the developing apparatus 24 is connected to the photoreceptor unit 20 via connecting units 7A and 7B, the positional relationship between the two is essentially fixed. Therefore, even if the developing apparatus 24 vibrates during image formation, the positional relationship between the developing apparatus 24 and the photoreceptor unit 20 will hardly change due to the vibration.

[0133] Furthermore, in this image forming apparatus 1, when performing maintenance or replacement work such as the photosensitive drum 21 or the developing apparatus 24, it is necessary to disconnect the connection between the photosensitive unit 20 and the developing apparatus 24.

[0134] In this case, such as Figure 6 or Figure 7 As shown, the screws that serve as the fixing unit 8 are removed to release the fixation between the connecting units 7A and 7B and the fixed surface 215 of the photoreceptor unit 20, thereby releasing the connection. The release of this connection is performed in the same manner as the connection operation, while the aforementioned pull-out movable body, which houses the photoreceptor unit 20, the developing device 24, etc., is being pulled out of the housing 10 to the outside.

[0135] By removing the link, such as Figure 6 or Figure 7 As shown, the developing apparatus 24 can be moved in the direction C, separated from the photoreceptor unit 20, while supported by the aforementioned movable support unit 63, thereby enabling it to be configured to separate the developing apparatus 24 from the photoreceptor unit 20. Furthermore, once it is configured to be separated, operations such as disassembling the photoreceptor unit 20 or the developing apparatus 24 can be performed for replacement.

[0136] Incidentally, when the connection via connecting units 7A and 7B is released, for example, the pressing unit 65 can release the pressure on the developing apparatus 24 by releasing the fixing state of the mounting plate 66 and the two ends of the connecting member 151. Thus, it is not necessary to overcome the pressing of the pressing unit 65 to move the developing apparatus 24 in the direction C separating it from the photosensitive unit 20.

[0137] Furthermore, when reconnecting the photoreceptor unit 20 and the developing apparatus 24, it can be easily performed by repeating the connection operation using the connection units 7A and 7B as described above.

[0138] As explained above, according to this image forming apparatus 1, compared to the case where the developing apparatus 24 and the photosensitive unit 20 are not connected by detachably fixed connecting units 7A and 7B, it is possible to suppress the change of the gap S between the developing roller 57 and the photosensitive drum 21 in the developing apparatus 24 due to the vibration generated by the developing apparatus 24 and the like during image forming operations.

[0139] Therefore, in the image forming apparatus 1, it is also possible to suppress image quality degradation caused by fluctuations in the gap S between the developing roller 57 and the photosensitive drum 21 due to vibration. Furthermore, in this image forming apparatus 1, the developing device 24 and the photosensitive unit 20 are connected by fixed connecting units 7A and 7B, making it easy to set the aforementioned gap S.

[0140] Furthermore, in this image forming apparatus 1, even when reconnection is required, the connection operation using the connection units 7A and 7B is completed while the developing unit 24 is pressed by the pressing unit 65. The gap S between the developing roller 57 and the photosensitive drum 21 is easily maintained at a fixed distance by the gap holding member 61, and there is no need to perform an operation to adjust the gap S.

[0141] Furthermore, in this image forming apparatus 1, the direction K of the fixing unit 8 fixing the connecting units 7A and 7B is set to intersect with the pressing direction P of the pressing unit 65 (see reference). Figure 9 Therefore, compared to the case where the fixing unit 8 is not configured in this way, the distance S between the developing roller 57 and the photosensitive drum 21 held by the spacing holding member 61 is well maintained, without any concern about changes due to slight misalignment of the fixing unit 8, such as in the tilting direction. The closer the fixing direction K of the fixing unit 8 is to being perpendicular to the pressing direction P, the more reliably such an action effect can be obtained.

[0142] Furthermore, in this image forming apparatus 1, even if the connecting units 7A and 7B are sometimes tilted due to tolerances or other factors when fixed by the fixing unit 8, the tilting state can be relieved by shifting one end of the connecting units 7A and 7B relative to the mounting shaft 67 in the length direction M of the elongated hole of the mounting hole 72. It can also avoid the state of deformation caused by forcibly fixing the connecting units 7A and 7B when they are tilted by the fixing unit 8.

[0143] Furthermore, in this image forming apparatus 1, since the length direction M of the elongated hole of the mounting hole 72 in the connecting units 7A and 7B is parallel to the direction K of fixing the connecting units 7A and 7B by the fixing unit 8, the gap S between the developing roller 57 and the photosensitive drum 21 is stably maintained, and there is no concern that fixing the connecting units 7A and 7B by the fixing unit 8 may cause the developing apparatus 24 to shift and change.

[0144] Furthermore, in this image forming apparatus 1, regarding the connecting units 7A and 7B, since the imaginary line VL connecting the center Oa of the part installed in the developing apparatus 24 and the center Ob of the part fixed to the fixed part 20h (the other end 70b) is configured to be parallel to the direction C that moves away by the moving support unit 63, although the developing apparatus 24 is supported so that it can move away from the photosensitive unit 20 in the direction C, the distance S between the developing roller 57 and the photosensitive drum 21 of the developing apparatus 24 can be easily set by the connection of the connecting units 7A and 7B, and the variation caused by the vibration of the distance S can be suppressed.

[0145] Furthermore, in this image forming apparatus 1, since the left and right ends of the photosensitive unit 20 and the left and right ends of the developing apparatus 24 in the length direction D are respectively connected by two connecting units 7A and 7B, the gap between the developing roller 57 and the photosensitive drum 21 in the axial direction J can be easily set compared to the case where only one side is connected by the connecting unit 7, and the variation caused by the vibration of the gap S is suppressed more reliably. Moreover, the gap S is maintained with higher precision by performing necessary adjustments related to the gap S through the adjustment unit 612 of the gap holding member 61.

[0146] Furthermore, in the image forming apparatus 1, even if the amount of developer 18 used may increase due to the overall enlargement of the developing apparatus 24 or the adoption of a structure that extends its length direction D, resulting in increased vibration of the conveying components, or if the image forming apparatus 2 vibrates during loading and unloading operations such as when the user pulls the image forming apparatus 2 out of the image forming apparatus 1, by connecting the photosensitive unit 20 and the developing apparatus 24 using the connecting units 7A and 7B, it is possible to suppress the change of the gap S between the developing roller 57 and the photosensitive drum 21 due to operational vibration.

[0147] Furthermore, in this case, there is no need to take countermeasures to increase the pressure of the pressing unit 65 when pressing in order to suppress the change of the interval S caused by the vibration of the operation, and there is no concern that the components in the developing device 24 and the like will be deformed or damaged due to the strong pressing of the pressing unit 65 after the pressure is increased.

[0148] Other implementation methods.

[0149] In the above embodiment 1, the connecting unit 7 was described as being fixed from top to bottom by the fixing unit 8 in a state where its other end 70b is in contact with the fixed surface 215 located at the upper part of the shaft support portion 211 in the photosensitive unit 20. However, the connecting unit 7 is not limited to this and may be composed of other structures as illustrated below.

[0150] For example, the connecting unit 7 can also be a structure in which its other end 70b is in contact with the fixed surface formed on the side surface of the shaft support portion 211 in the photosensitive unit 20 from the side, and is fixed from the side by the fixing unit 8 in a horizontal or other direction. However, in the case of the connecting unit 7 being a structure that is fixed from top to bottom by the fixing unit 8, it is possible to suppress vibrations in the direction perpendicular to the axial direction J of the photosensitive drum 21 (shaft portion 21c) caused by the rotation of the photosensitive drum 21, or vibrations in the direction perpendicular to the axial direction of the developing roller 57 (shaft portion 57c) caused by the rotation of the developing roller 57.

[0151] Furthermore, the connecting unit 7 can also be fixed in the inclined direction by the fixing unit 8 while its other end 70b is in contact with the fixed surface of the side surface portion formed by the inclined surface of the shaft support portion 211 in the photosensitive unit 20 in the inclined direction corresponding to the inclined surface.

[0152] Furthermore, the connecting unit 7 can also be a structure in which its two ends 70a and 70b are fixed by a detachable fixing unit 8.

[0153] Furthermore, the connecting unit 7 may be a structure in which one end 70a is fixedly mounted to a part of the housing 50 of the developing apparatus 24 or an integral structure made as part of the housing 50.

[0154] In addition, the number and shape of the connecting unit 7 can be changed. Furthermore, the mounting hole 72 in the connecting unit 7 can be a regular round hole instead of an elongated hole.

[0155] Furthermore, the structure of the mounting shaft 67 embedded in the mounting hole 72 can be changed according to the type of the connecting unit 7. For example, other structures can be adopted regarding its cross-sectional shape and protruding direction.

[0156] Regarding the fixing unit 8, it is not limited to a fitting unit in which the protrusion 81 is a screw and the fitting hole 82 is a threaded hole. For example, it could also be a fitting unit in which the protrusion 81 is a protrusion like a letter and the fitting hole 82 is a fitting hole that fits into the protrusion.

[0157] The protrusion 81, which is composed of protrusions, is provided on the fixed portion 20h of the photoreceptor unit 20, but it can also be provided on the other end 70b of the connecting unit 7. Regarding the mating hole 82, it is provided on the other end 70b of the connecting unit 7, but it can also be provided on the fixed portion 20h of the photoreceptor unit 20. Furthermore, in this case, it is preferable to use an anti-detachment unit with the protrusion 81 and the mating hole 82 (a shape countermeasure to prevent detachment, such as threaded fixing or pin connection).

[0158] Furthermore, the fixed unit 8 can also be a unit in a form other than a mating unit.

[0159] Furthermore, in Embodiment 1 described above, the interval holding member 61 is provided on the developing apparatus 24 as an example of an interval holding unit. However, the interval holding member can also be provided on the photoreceptor unit 20, with its free end (the other end) contacting the shaft support portion of the shaft portion 57c supporting the developing roller 57, and being fixed by the fixing unit 8. In this case, it is preferable that the interval holding member is rotatably provided on the photoreceptor unit 20.

[0160] Furthermore, in the above-described embodiment 1, the component 70 constituting the connecting units 7A and 7B has the following structure: one end 70a is rotatably mounted on the developing apparatus 24, and the other end 70b is fixed to the fixed portion 20h of the photoreceptor unit 20 via a detachable fixing unit 8. The photoreceptor unit 20 is held and mounted on the pull-out movable body composed of pull-out frames 15A, 15B, etc., with the photosensitive drum 21 positioned at the reference position E1.

[0161] Therefore, the connecting units 7A and 7B can also be configured such that one end 70a of the component 70 constituting itself is fixed by a detachable fixing unit 8 to a pull-out frame 15A or 15B configured in the housing 10 to be pulled out to the outside, or a connecting component (frame) connecting these.

[0162] Furthermore, in the above-described embodiment 1, an image forming apparatus for forming monochrome images was exemplified as the image forming apparatus 1. However, as long as the structure connecting the photoreceptor unit 20 and the developing apparatus 24 via the connecting unit 7 is applicable, an image forming apparatus composed of other forms (e.g., an image forming apparatus for forming multicolor images, an image forming apparatus using an intermediate transfer medium, etc.) can be used. In the case of an image forming apparatus for forming multicolor images, the photoreceptor unit 20 and the developing apparatus 24 have multiple photoreceptor units 20 and a developing apparatus 24 required to reproduce the colors of the multicolor image.

[0163] Furthermore, regarding the developing apparatus 24, it can be any other type of developing apparatus as long as it is effectively connected to the photosensitive unit 20 via the connecting unit 7.

Claims

1. An image forming apparatus, comprising: A photoreceptor unit, wherein the photoreceptor unit has a photoreceptor; A developing apparatus, wherein the developing apparatus has a developing roller; An interval holding unit is disposed on the photoreceptor unit or the developing apparatus, wherein a portion of the interval holding unit abuts against a portion of the developing apparatus or the photoreceptor unit to maintain the interval between the developing roller and the photoreceptor; The pressing unit presses the developing device toward the photoreceptor unit; as well as A connecting unit that secures and connects the photoreceptor unit and the developing apparatus using a detachable fixing unit. The connecting unit is configured to rotatably mount a mounting hole at one end onto a mounting shaft, wherein the mounting shaft is disposed in the developing apparatus, and the other end of the connecting unit is fixed to the fixed portion of the photoreceptor unit by the fixing unit. The mounting hole is formed by an elongated hole that can be displaced in the direction of the tilted state when the connecting unit is released from its fixed position.

2. The image forming apparatus according to claim 1, wherein, The direction in which the fixing unit fixes the connecting unit intersects with the pressing direction of the pressing unit.

3. The image forming apparatus according to claim 2, wherein, The direction in which the fixing unit fixes the connecting unit intersects the axis of the photoreceptor.

4. The image forming apparatus according to claim 1, wherein, The length direction of the elongated hole in the connecting unit is parallel to the direction in which the fixing unit is fixed.

5. The image forming apparatus according to claim 1, wherein, The fixed part is a support unit that supports the shaft portion of the photosensitive element.

6. The image forming apparatus according to claim 1, wherein, The fixing unit is a fitting unit that allows the protrusion and the fitting hole to be detachably fitted together. The fitting hole or protrusion exists in a position whereby, when the developing device is pressed toward the photosensitive unit by the pressing unit, the fitting hole or protrusion can be fitted with the protrusion or fitting hole.

7. The image forming apparatus according to claim 1, wherein, The interval holding unit has an adjustment unit for adjusting the interval.

8. The image forming apparatus according to claim 1, wherein, The image forming apparatus includes a movable support unit that supports the developing apparatus so that it can move away from the photoreceptor unit. The connecting unit is in such a state that the line connecting the center of the part installed in the developing apparatus and the center of the part fixed to the fixed part is parallel to the direction in which it moves away through the moving support unit.

9. The image forming apparatus according to claim 1, wherein, The connecting unit connects the left and right ends of the photoreceptor unit along its length to the left and right ends of the developing device along its length.

10. An image forming apparatus comprising: A photoreceptor unit, wherein the photoreceptor unit has a photoreceptor; A frame that holds the photoreceptor unit; A developing apparatus, wherein the developing apparatus has a developing roller; An interval holding unit is disposed on the photoreceptor unit or the developing apparatus, wherein a portion of the interval holding unit contacts a portion of the photoreceptor unit or the developing apparatus to maintain the interval between the developing roller and the photoreceptor; The pressing unit presses the developing device toward the photoreceptor unit; as well as A connecting unit that secures and connects the frame and the developing apparatus using a detachable fixing unit. The connecting unit is configured to rotatably mount a mounting hole at one end onto a mounting shaft, wherein the mounting shaft is disposed in the developing apparatus, and the other end of the connecting unit is fixed to the fixed portion of the photoreceptor unit by the fixing unit. The mounting hole is formed by an elongated hole that can be displaced in the direction of the tilted state when the connecting unit is released from its fixed position.

Images