JP4363109B2 - Image forming apparatus - Google Patents

Description

  The present invention forms an electrostatic latent image, develops it with toner, forms a toner image, and finally transfers and fixes the toner image on the recording medium, thereby forming an image composed of the fixed toner image on the recording medium. The present invention relates to an image forming apparatus.

  In image forming apparatuses used for electrophotographic copying machines, printers, facsimiles, and the like, a photosensitive member is charged, an electrostatic latent image is formed on the surface of the photosensitive member by image exposure, and a toner image is formed by developing with toner. Then, the formed toner image is transferred directly onto the recording medium or fixed by, for example, an intermediate transfer member interposed therebetween, thereby forming an image on the recording medium.

  In such an image forming apparatus, a fixing unit and a static eliminator mounted in an openable / closable manner are provided above the photosensitive unit in which the photosensitive unit is disposed in the main unit casing. A technique has been proposed in which a portion of the housing where the transfer unit and the static eliminator are attached is opened, and the photosensitive unit is attached and detached from above the main body housing (see Patent Document 1).

Also, a photoconductor unit provided with a photoconductor, an intermediate transfer body unit provided with an intermediate transfer member, and a fixing unit mounted on the main body housing so as to be openable and closable above the photoconductor unit and the intermediate transfer member unit. When replacing the photoconductor unit and the intermediate transfer body unit, open the portion of the main body housing where the fixing unit is mounted, and open the photoconductor unit and the intermediate transfer body unit from above the main body housing. A technique for attaching and detaching is proposed (see Patent Document 2).
Japanese Patent Laid-Open No. 2-157858 JP 2000-105493 A

  However, the technique proposed in Patent Document 1 is a technique for attaching and detaching the photosensitive unit from the main body casing, and does not disclose a technique for attaching and detaching the intermediate transfer body unit from the main body casing.

  Further, since the technique proposed in Patent Document 2 is to pull up the photosensitive unit and the intermediate transfer unit from above the main body casing along the vertical straight line direction, the replacement of the photosensitive unit and the intermediate transfer unit There is a problem that the operability is poor when exchanging.

  In view of the above circumstances, an object of the present invention is to provide an image forming apparatus that can easily replace a photoreceptor unit and an intermediate transfer body unit.

The image forming apparatus of the present invention that achieves the above object forms an electrostatic latent image, develops it with toner, forms a toner image, and finally transfers and fixes the toner image on a recording medium. In an image forming apparatus for forming an image composed of a fixed toner image on a medium,
A photoconductor unit provided with a photoconductor on which an electrostatic latent image is formed while rotating and a toner image is formed by development, and an intermediate transfer material provided with an intermediate transfer member that receives the transfer of the toner image from the photoconductor while rotating A first unit that is one of the photosensitive unit and the intermediate transfer unit, and can be separated and combined with the second unit, and the first unit is a first unit. The process cartridge is mounted in a state where it is united with the second unit, and the process cartridge is slid in the direction of the rotation axis so that it can be pulled out, and the process cartridge is supported by the slide operation of the process cartridge in the intended operation position. It has a main unit housing,
When the process cartridge is pulled out from the main body casing, the process cartridge engages with the main body casing at a predetermined pulling position to prevent further pulling out, and allows further pulling freely by operation. In the operation of housing in the main body housing from the state of being further pulled out, it is provided with a pulling prevention mechanism that returns to a position that engages with the main body housing at the pulling position when it is pulled out again.
The process cartridge is characterized in that the second unit can be separated from and merged with the first unit when the process cartridge is pulled out to the pull-out position.

  In the image forming apparatus of the present invention, when a process cartridge having a photoconductor unit and an intermediate transfer body unit is pulled out from the main body casing, the process cartridge is engaged with the main body casing at a predetermined pulling position to be in a so-called locked state. Since further drawing is prevented, it is possible to prevent the user from pulling out the process cartridge too much and dropping the process cartridge due to an erroneous operation or the like. Further, the process cartridge can be easily removed by releasing the locked state by operation and performing further drawing. Further, in the operation of accommodating the main body housing from the further pulled out state, when it is pulled out again, it returns to the position where it engages with the main body housing at the above-mentioned drawing position. It can be locked by simply plugging it into the unit housing, and it is easy to operate. Accordingly, it is possible to easily replace the photosensitive unit included in the process cartridge and the intermediate transfer unit.

Here, the main body casing protrudes into a slide operation area of the process cartridge that slides with respect to the main body casing at two positions separated from each other in the sliding direction of the process cartridge. A first convex portion and a second convex portion, respectively, on the back side and the near side in the drawing direction from the main body housing,
The process cartridge has an engagement position that engages with the first protrusion when the process cartridge is pulled out to a predetermined pulling position and prevents further pulling of the process cartridge from the pulling position. A stopper member movable between the retracted position retracted from the engagement with the first convex portion, and a spring member for biasing the stopper member so that the stopper member is held at the engaged position; When the stopper member is in the engagement position, the stopper member is in a predetermined pre-operation state, and when the stopper member is in the retracted position, the stopper member is in a predetermined post-operation state. The operating member to be moved to the retracted position and the operating member in the post-operation state to overcome the urging force of the spring member to bring the operating member into the post-operation state And an operation member holding member for holding,
The operation member is further pulled out from the pull-out position in a state where the operation member is held in the post-operation state by the operation member holding member and the stopper member is held in the retracted position. When the process cartridge is slidably accommodated in the main body housing, the operation member is released from the engagement by the operation member holding member by contacting the second convex portion, and the operation is performed by the biasing force of the spring member. It is preferable that the member is provided with a contact portion that returns the member to the pre-operation state and returns the stopper member to the engagement position on the rear side in the slide housing direction from the first convex portion.

  In this way, when the process cartridge is pulled out to a predetermined pulling position, it engages with the first convex portion on the back side of the main body housing in the pulling direction, so that it becomes a so-called locked state from the pulling position of the process cartridge. Further withdrawal of the process cartridge is prevented, so that the process cartridge is prevented from falling. Further, the process cartridge can be easily removed by releasing the locked state by operating the operation member and performing further drawing. Further, when the process cartridge in the further drawn state is slid and accommodated in the main body housing, the contact portion of the operation member contacts the second convex portion. As a result, the unlocked state shifts to the locked state, and the engagement position returns to the back side in the slide accommodation direction from the first convex portion. For this reason, in the unlocked state, the process cartridge can be brought into the locked state simply by being inserted into the main body housing, and the process cartridge can be easily accommodated in the main body housing. Therefore, the operability is excellent and the configuration is simplified to reduce the cost.

  The photoconductor unit may be the first unit, and the intermediate transfer unit may be the second unit.

  In the image forming apparatus of the present invention, when the process cartridge having the photosensitive unit and the intermediate transfer body unit is pulled out from the main body casing, the process cartridge is engaged with the main body casing at a predetermined pulling position to prevent further drawing. Therefore, the process cartridge is prevented from dropping. In addition, the process cartridge can be easily removed by releasing the locked state by operation, and the process cartridge is accommodated in the main body casing from the further pulled out state. In order to return to the above-described drawing position, the process cartridge can be easily locked in the main body housing by simply inserting the process cartridge into the main body housing in the unlocked state, and the operability is good. Accordingly, it is possible to easily replace the photosensitive unit included in the process cartridge and the intermediate transfer unit.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention as viewed from the front side, and FIG. 2 is a configuration diagram of a main part of the image forming apparatus shown in FIG.

  An image forming apparatus 100 shown in FIG. 1 forms an electrostatic latent image, develops it with toner, forms a toner image, and finally transfers and fixes the toner image on the recording medium. An image forming apparatus that forms an image including a fixed toner image. Specifically, the image forming apparatus 100 is a so-called tandem type in which image forming engines for each color of yellow (Y), magenta (M), black (K), and cyan (C) are arranged in parallel. The printer can print a single-color image and can print a full-color image including the four-color toner images.

  An image forming apparatus 100 illustrated in FIG. 1 includes a process cartridge 101 and a main body housing 102.

  As shown in FIG. 2, the process cartridge 101 is provided with a photosensitive unit 1 provided with photosensitive members 11Y, 11M, 11K, and 11C on which electrostatic latent images are formed while rotating and toner images are formed by development (in the present invention). The intermediate transfer members 21 and 22 that receive the transfer of the toner image from the photoconductors 11Y, 11M, 11K, and 11C while rotating, and the transfer of the toner image from these intermediate transfer members 21 and 22). And an intermediate transfer body unit 2 (corresponding to a second unit referred to in the present invention) provided with another intermediate transfer body 23 for receiving. The photoconductor unit 1 can be separated and combined with the intermediate transfer body unit 2, and the process cartridge 101 can be mounted and pulled out in a state where the photoconductor unit 1 is combined with the intermediate transfer body unit 2. Slide in the direction. The main body housing 102 receives the slide mounting of the process cartridge 101 and supports the process cartridge 101 at an intended operation position.

  In the image forming apparatus 100, an exposure unit 3, a developing unit 4, a paper feeding unit 5, and a fixing unit 6 are arranged in a positional relationship as shown in FIG.

  The exposure unit 3 is for writing an electrostatic latent image on the photoconductors 11Y, 11M, 11K, and 11C constituting the photoconductor unit 1, and includes a light source such as a semiconductor laser (not shown) and an image from the light source. Optical system parts such as polygon mirrors, reflecting mirrors, various lenses, and the like are appropriately arranged to guide the beam light Bm emitted based on the information onto the corresponding photoreceptors 11Y, 11M, 11K, and 11C for scanning exposure. Yes. The exposure unit 3 scans and exposes the light beam Bm onto the photoreceptors 11Y, 11M, 11K, and 11C through the gap between the developing units 4. Thereby, an electrostatic latent image having a predetermined surface potential is formed on the photoreceptors 11Y, 11M, 11K, and 11C.

  As shown in FIG. 2, the developing unit 4 includes developing devices 41Y, 41M, 41K, and 41C that are arranged so as to face the photoconductors 11Y, 11M, 11K, and 11C. Each of the developing devices 41Y, 41M, 41K, and 41C employs a so-called magnetic brush developing method, and a two-component developer containing toner and a carrier is accommodated in the device. Further, the developing devices 41Y, 41M, 41K, and 41C include developing rolls 42Y, 42M, 42K, and 42C that rotate in close proximity to and in opposition to the photoconductors 11Y, 11M, 11K, and 11C at a predetermined minute interval. The developer forms a magnetic brush on the developing rolls 42Y, 42M, 42K, and 42C, and rubs the photoreceptors 11Y, 11M, 11K, and 11C as the developing rolls 42Y, 42M, 42K, and 42C rotate. A developing bias voltage in which a DC component is superimposed on an AC component is applied to the developing rolls 42Y, 42M, 42K, and 42C, thereby electrostatic latent images formed on the photoreceptors 11Y, 11M, 11K, and 11C. Toner is electrostatically attached only to the image to form a toner image.

  The paper feed unit 5 shown in FIG. 1 is provided with a paper feed tray 51 that stacks and stores a plurality of recording papers P and a feeding mechanism 52 that feeds the recording papers P one by one from the paper feed tray 51. .

  The fixing unit 6 includes a heating roll 61, a pressure roll 62, and a paper discharge roll 63.

  Further, the image forming apparatus 100 includes a sheet conveying roll 71 that conveys the recording sheet P fed from the sheet feeding unit 56, a registration roll 72 that adjusts the conveyance timing of the recording sheet P, and toner on the intermediate transfer member 23. A transfer roll 73 for transferring the image onto the recording paper P, a paper discharge roll 74 for discharging the recording paper P to the outside of the apparatus, and a paper discharge unit 75 for storing the discharged paper are provided.

  Further, the image forming apparatus 100 includes toner cartridges 81Y, 81M, 81K, and 81C that store toners of the respective colors.

  Further, as shown in FIG. 2, on the peripheral surfaces of the photoreceptors 11Y, 11M, 11K, and 11C, charging rolls 12Y that charge the surfaces of the photoreceptors 11Y, 11M, 11K, and 11C to a predetermined background portion potential. 12M, 12K, and 12C, the developing devices 41Y, 41M, 41K, and 41C described above, and the toner temporary holding brushes that temporarily hold the toner and the like remaining on the peripheral surfaces of the photoreceptors 11Y, 11M, 11K, and 11C All the rolls 13Y, 13M, 13K, and 13C are rotatably attached. The temporary toner holding brush rolls 13Y, 13M, 13K, and 13C discharge the temporarily held toner onto the photoreceptors 11Y, 11M, 11K, and 11C at a predetermined timing. The toner discharged onto the photoreceptors 11Y, 11M, 11K, and 11C is collected by the developing devices 41Y, 41M, 41K, and 41C.

  Each of the photoconductors 11Y, 11M, 11K, and 11C is formed of a cylindrical drum having the same outer diameter on which a photosensitive layer made of an organic photosensitive material or the like is formed.

  Each of the charging rolls 12Y, 12M, 12K, and 12C is formed by coating a conductive elastic foam with a certain thickness around a metal roll body. The layer is rotatably attached to a support frame (not shown) so that the layer contacts the surface of the photoreceptors 11Y, 11M, 11K, and 11C. The charging rolls 12Y, 12M, 12K, and 12C are applied with a DC voltage as a charging voltage to the roll body, and between the elastic foam layer and the peripheral surfaces of the photoreceptors 11Y, 11M, 11K, and 11C. The peripheral surfaces of the photoconductors 11Y, 11M, 11K, and 11C are charged by generating a discharge at a minute gap in FIG.

  Further, in the temporary toner holding brush rolls 13Y, 13M, 13K, and 13C, a plurality of brush bristles are implanted around the metal roll body so as to have a predetermined distribution density. These toner holding brush rolls 13Y, 13M, 13K, 13C are rotatably attached to a support frame (not shown).

  Further, a temporary toner holding brush roll that temporarily holds toner or the like remaining on the peripheral surfaces of the intermediate transfer members 21, 22, 23 on the peripheral surfaces of the intermediate transfer members 21, 22, 23 shown in FIG. 24a, 24b, and 24c are rotatably attached. The temporarily held toner is returned to the peripheral surfaces of the intermediate transfer members 21, 22, and 23 at a predetermined timing. Collecting rolls 25a, 25b, and 25c for collecting toner remaining on the peripheral surfaces of the intermediate transfer members 21, 22, and 23 are rotatably attached to the peripheral surfaces of the intermediate transfer members 21, 22, and 23. In the collecting rolls 25a, 25b, and 25c, not only the toner remaining and adhered to the peripheral surfaces of the intermediate transfer members 21, 22, and 23 is collected, but also temporarily held by the temporary toner holding brush rolls 24a, 24b, and 24c. The toner returned onto the rear intermediate transfer members 21, 22, 23 is also collected.

The intermediate transfer members 21, 22, and 23 each have a low resistance elastic layer (resistance value: about 0.1 mm to 10 mm) made of conductive silicone rubber or the like on a metal pipe of the same outer diameter made of iron, aluminum, or the like. 10 ² to 10 ³ Ω), and a high release layer (resistance value: about 10 ⁵ to 10 ¹³ Ω) having a thickness of 3 μm to 100 μm made of fluorine rubber or the like on the surface of the low resistance elastic layer. The drum body formed is supported by a rotating spindle. These intermediate transfer members 21, 22, and 23 are rotatably attached via bearings in a state in which each rotation support shaft is parallel to a support frame (not shown) with a predetermined interval in the vertical direction.

  Further, the intermediate transfer members 21 and 22 electrostatically primarily transfer the toner images on the photosensitive members 11Y and 11M and the photosensitive members 11K and 11C to the intermediate transfer members 21 and 22, respectively. , 22 is applied with a first transfer bias from a bias power source (not shown) via a rotating shaft for maintaining the surface potential of the main body at a predetermined potential (for example, about +250 V to +500 V). In addition, the surface potential of the intermediate transfer body 23 is set to a predetermined value on the intermediate transfer body 23 in order to electrostatically secondary transfer the toner images on the intermediate transfer bodies 21 and 22 to the intermediate transfer body 23. The second transfer bias for holding at a potential (for example, about +600 V to +1200 V) is applied from a bias power source (not shown) via a rotating shaft.

  The temporary toner holding brush rolls 24a, 24b, and 24c have the same configuration as the temporary toner holding brush rolls 13Y, 13M, 13K, and 13C used in the photoreceptor unit 2, and the intermediate transfer members 21, 22, It is attached to rotate in contact with 23.

  The collection rolls 25a, 25b, and 25c are metal rolls that rotate in contact with the intermediate transfer members 21, 22, and 23, and can electrostatically attract unnecessary toner on the intermediate transfer members 21, 22, and 23. A bias roll to which a bias voltage is applied. The waste toner adsorbed and collected by the collection rolls 25a, 25b, and 25c is scraped and conveyed by a cleaning blade in contact with the collection rolls 25a, 25b, and 25c, and collected in a waste toner collection container (not shown). .

  The color image formation in the image forming apparatus 100 configured as described above is generally performed as follows.

  First, after the four photosensitive members 11Y, 11M, 11K, and 11C are uniformly charged by the charging rolls 12Y, 12M, 12K, and 12C in the photosensitive unit 1, the charged photosensitive members 11Y, 11M, 11K, and 11C are charged. The surface of 11C is irradiated with each laser beam light BmY, BmM, BmK, BmC corresponding to each color from the exposure unit 3, and an electrostatic latent image of each color is formed. Next, the electrostatic latent images on the photoconductors 11Y, 11M, 11K, and 11C are developed by the developing devices 41Y, 41M, 41K, and 41C constituting the developing unit 4 and visualized as toner images of the respective colors.

  Subsequently, the toner images of the respective colors formed on the photoconductors 11Y, 11M, 11K, and 11C are electrostatically primary-transferred onto the intermediate transfer bodies 21 and 22, respectively. That is, yellow and magenta toner images formed on the photoconductors 11Y and 11M are magenta and yellow in this order on the intermediate transfer member 21, and black and cyan toner images formed on the photoconductors 11K and 11C are cyan and black. Are sequentially transferred so as to be superimposed on the intermediate transfer drum 22 in this order. As a result, a multiple toner image composed of a magenta toner image and a yellow toner image is formed on the intermediate transfer member 21, while a multiple toner image composed of a cyan toner image and a black toner image is formed on the intermediate transfer member 22. A toner image is formed.

  Subsequently, each of the multiple toner images formed on the intermediate transfer members 21 and 22 is electrostatically secondary-transferred onto the intermediate transfer member 23. As a result, the toner image on the intermediate transfer member 21 (M, Y from the lower layer side) and the toner image on the intermediate transfer drum 22 (C, K from the lower layer side) are transferred onto the intermediate transfer member 23 in this order. As a result, a multiple toner image is formed by superimposing Y, M, K, and C in this order from the lower layer side. Next, the four color multiplex toner images are conveyed toward the final transfer portion that is in pressure contact with the transfer roll 73 as the intermediate transfer drum 23 rotates.

  In accordance with the formation of such a toner image, the recording paper P is supplied from the paper supply unit 5 to the final transfer portion at a predetermined timing. That is, only one sheet of recording paper P stored in the storage tray 51 is sent to the final transfer section via the feeding mechanism 52, the paper transporting roll 71, and the registration roll 72 at a predetermined timing. As a result, the four color (Y, M, K, C) toner images on the intermediate transfer member 23 are electrostatically transferred onto the recording paper P in a pressurized state at the final transfer portion. .

  Next, the recording paper P onto which the four color toner images have been transferred is sent to the fixing unit 6 and passes through a fixing nib portion between a heating roll 61 and a pressure roll 62 constituting the fixing unit 6. The fixing process is performed by heating and pressurization, and the paper is finally discharged to the paper discharge unit 75. By executing a series of image forming processes as described above, a full color image is formed on one recording sheet P.

  FIG. 3 is a schematic perspective view of the image forming apparatus shown in FIGS. 1 and 2 as viewed from the front side.

  FIG. 3 shows a process cartridge 101 including a photoconductor unit 1 provided with photoconductors 11Y, 11M, 11K, and 11C and an intermediate transfer body unit 2 provided with intermediate transfer bodies 21, 22, and 23. Yes. As shown in FIG. 3, the photosensitive unit 1 can be separated and combined in the direction of arrow A with respect to the intermediate transfer unit 2, and the arrow B in a state where the photosensitive unit 1 is combined with the intermediate transfer unit 2. Mounted in the direction and slid freely.

  The process cartridge 101 will be described in detail later. When the process cartridge 101 is pulled out from the main body housing 102, the process cartridge 101 is engaged with the main body housing 102 at a predetermined pulling position to prevent further drawing, and further by operation. A drawer that can be pulled out freely and is returned to a position where it is engaged with the main body housing 102 at the pulled out position when it is pulled out again by the operation of being housed in the main body housing 102 from the state where it is pulled out from the pulled out position. A blocking mechanism 120 is provided.

  Further, the process cartridge 101 is provided with a handle member 110 which is an operation element for mounting and unmounting the main body housing 102.

  The main body housing 102 is provided with positioning pins 102_1 for positioning the process cartridge 101 and projecting in the drawing direction of the process cartridge 101 (front side in FIG. 3). Further, the main body housing 102 is provided with photoreceptor unit support portions 102_2Y, 102_2M, 102_2K, and 102_2C that receive and support the leading ends of the photoreceptors 11Y, 11M, 11K, and 11C in the accommodation direction. .

  The intermediate transfer body unit 2 includes a pair of support plates 2_1 and 2_2 that support the intermediate transfer bodies 21, 22, and 23 on both sides of the rotation shaft. A sliding member 2_3 is provided on the support plate 2_1.

  Further, the intermediate transfer unit 2 includes a positioning hole 2_1a through which the positioning pin 102_1 penetrates when the support plate 2_1 at the front of the process cartridge 101 in the drawing direction is slid into the main body housing 102, and the photosensitive unit 1. A photoreceptor unit receiving part 2_4 is provided.

  Here, the sliding member 2_3 moves the process cartridge 101 to the main body by an operation in the mounting direction (clockwise in FIG. 3) of the handle member 110 in a state where the process cartridge 101 is slid into the main body housing 102. The photosensitive unit 1 is positioned relative to the intermediate transfer unit 2 at the same time as positioning relative to the housing 102. Further, the operation of the handle member 110 in the mounting release direction (the state shown in FIG. 3) releases the positioning of the process cartridge 101 with respect to the main body housing 102 and allows the process cartridge 101 to be pulled out from the main body housing 102. At the same time, the positioning of the photoconductor unit 1 with respect to the intermediate transfer body unit 2 is canceled, and the photoconductor unit 1 is temporarily placed with respect to the intermediate transfer body unit 2. Specifically, the sliding member 2_3 slides on the support plate 2_1 in conjunction with the turning operation of the handle member 110, and slides in conjunction with the turning operation of the handle member 110 in the mounting direction. This is a member for positioning the process cartridge 101 to the main body housing 102 by fixing the positioning pin 102_1 penetrating into the positioning hole 2_1a to the support plate 2_1.

  4 is a perspective view showing the drawer blocking mechanism shown in FIG. 3, FIG. 5 is a top view showing the drawer blocking mechanism in the locked state, and FIG. 6 is a top view showing the inside of the drawer blocking mechanism in the unlocked state. It is.

  The drawer block mechanism 120 shown in FIG. 4 includes a process that slides with respect to the main body housing 102 at two locations that are part of the main body housing 102 and are separated from each other in the sliding direction indicated by the arrow B of the process cartridge 101. The first convex portion 102_11 and the second convex portion 102_12 projecting into the slide operation area of the cartridge 101, respectively, on the back side and the near side in the drawing direction indicated by the arrow C from the main body housing 102 of the process cartridge 101, respectively. Is provided.

  Further, the pull-out preventing mechanism 120 includes a part of the process cartridge 101, and when the process cartridge 101 is pulled out to a predetermined pull-out position (the position shown in FIGS. 4 and 5), the pull-out preventing mechanism 120 has a first protrusion 102_11. An engagement position P (see FIG. 5) that engages and prevents further drawing from the pull-out position of the process cartridge 101, and a retreat position Q (see FIG. 6) retreated from engagement with the first convex portion 102_11. And a spring member 101_12 (see FIG. 6) that biases the stopper member 101_11 so that the stopper member 101_11 is held at the engagement position P.

  Further, the drawer preventing mechanism 120 is in a locked state (corresponding to a predetermined pre-operation state according to the present invention) when the stopper member 101_11, which is a part of the process cartridge 101, is in the engagement position P, and the stopper member. The operation member 101_13 that is in the unlocked state (corresponding to the predetermined post-operation state referred to in the present invention) when 101_11 is at the retracted position Q, and moves the stopper member 101_11 at the engagement position P to the retracted position Q by operation. Is provided.

  Further, the drawer preventing mechanism 120 is operated to engage the operation member 101_13 in the unlocked state, which is a part of the process cartridge 101, to overcome the urging force of the spring member 101_12 and hold the operation member 101_13 in the unlocked state. A member holding member 101_14 is provided. The operation member holding member 101_14 has an operation member holding hole 101_14a.

  Further, the operation member 101_13 includes a contact portion 101_13a and a ball member 101_13b.

  As shown in FIG. 5, when the pull-out prevention mechanism 120 is in the locked state, the ball member 13_13b and the operation member holding hole 101_14a are in a positional relationship shifted from each other, and therefore the ball member 13_13b and the operation member holding hole 101_14a are engaged. It has not been. Here, the operation member 101_13 is operated in the left direction of FIG. Then, the ball member 13_13b engages with the operation member holding hole 101_14a to be in the unlocked state shown in FIG. In this way, the operation member 101_13 is held in the unlocked state by the operation member holding member 101_14. The stopper member 101_11 is held at the retracted position Q.

  In such a state, the process cartridge 101 is further pulled out from the pulling-out position. Here, the process cartridge 101 pulled out in this way is slid into the main body housing 102. At this time, the contact portion 101_13a contacts the second convex portion 102_12. Then, the ball member 13_13b is detached from the operation member holding hole 101_14a, the operation member 101_13 is disengaged from the operation member holding member 101_14, and the operation member 101_13 returns to the locked state by the urging force of the spring member 101_12. In this way, the stopper member 101_11 is returned to the engagement position P on the rear side in the slide accommodation direction with respect to the first convex portion 102_11.

  In the image forming apparatus 100 of this embodiment, when the process cartridge 101 is pulled out to a predetermined pulling position, the stopper member 101_11 is engaged with the first convex portion 102_11 on the back side in the pulling direction of the main body housing 102. Since the process cartridge 101 is locked and further drawing from the drawing position is prevented, the process cartridge 101 is prevented from dropping. Further, the process cartridge 101 can be easily removed by releasing the locked state by operating the operation member 101_13 and performing further drawing. Further, when the process cartridge 101 in a further pulled-out state is slid and accommodated in the main body housing 102, the contact portion 101_13a of the operation member 101_13 contacts the second convex portion 102_12. Thereby, it shifts from the unlocked state to the locked state and returns to the back side in the slide accommodating direction from the first convex portion 102_12. For this reason, the process cartridge 101 can be brought into the locked state by simply inserting the process cartridge 101 into the main body housing 102 in the unlocked state, and the process cartridge 101 can be easily accommodated in the main body housing 102. Therefore, the operability is excellent and the configuration is simplified to reduce the cost.

1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention when viewed from the front side. FIG. 2 is a configuration diagram of a main part of the image forming apparatus illustrated in FIG. 1. FIG. 3 is a schematic perspective view of the image forming apparatus shown in FIGS. 1 and 2 as viewed from the front side. It is a perspective view which shows the drawer | drawing-out prevention mechanism shown in FIG. It is a top view which shows the drawer | drawing-out prevention mechanism in a locked state. It is a top view which shows the inside of the drawer | drawing-out prevention mechanism in a lock release state.

Explanation of symbols

2 Intermediate transfer body unit 2_1, 2_2 Support plate 2_1a Positioning hole 2_3 Sliding member 2_4 Photosensitive unit receiving part 3 Exposure unit 4 Developing unit 5 Feeding unit 6 Fixing unit 1 Photosensitive unit 11Y, 11M, 11K, 11C Photosensitive body 12Y , 12M, 12K, 12C Charging roll 13Y, 13M, 13K, 13C, 24a, 24b, 24c Toner temporary holding brush roll 21, 22, 23 Intermediate transfer member 25a, 25b, 25c Recovery roll 41Y, 41M, 41K, 41C Development Apparatus 42Y, 42M, 42K, 42C Developing roll 51 Paper feed tray 52 Feeding mechanism 56 Paper feed unit 61 Heating roll 62 Pressure roll 63 Paper discharge roll 71 Paper transport roll 72 Registration roll 73 Transfer roll 74 Paper discharge roll 75 Paper discharge section 1Y, 81M, 81K, 81C Toner cartridge 100 Image forming apparatus 101 Process cartridge 101_11 Stopper member 101_12 Spring member 101_13 Operation member 101_13a Abutting portion 101_13b Ball member 101_14 Operation member holding member 101_14a Operation member holding hole 102 Main body housing 102_1 Positioning pin 102_2Y, 102_2M, 102_2K, 102_2C Photosensitive unit support part 102_11 First convex part 102_12 Second convex part 110 Handle member 120 Pull-out prevention mechanism

Claims (2)

An image in which an electrostatic latent image is formed and developed with toner to form a toner image, and the toner image is finally transferred and fixed on the recording medium to form an image composed of the fixed toner image on the recording medium. In the forming device,
A photoconductor unit provided with a photoconductor on which an electrostatic latent image is formed while rotating and a toner image is formed by development, and an intermediate transfer body provided with an intermediate transfer member that receives the transfer of the toner image from the photoconductor while rotating A first unit that is one of the photosensitive unit and the intermediate transfer unit and can be separated and combined with respect to the other second unit, and the first unit The process cartridge is mounted in a state where it is combined with the second unit, and the process cartridge is slid in the direction of the rotation axis so that it can be pulled out, and the process cartridge is supported by the slide mounting of the process cartridge at an intended operation position. It has a main unit housing,
When the process cartridge is pulled out from the main body housing, the process cartridge engages with the main body housing at a predetermined pulling position to prevent further pulling out, and allows further pulling freely by operation. An operation of accommodating in the main body housing from the state of being further pulled out, and a pull-out preventing mechanism that returns to a position that engages with the main body housing at the pull-out position when it is pulled out again.
The process cartridge in a state drawn to the take-out position, I separation and coalescence freely ones der from the first unit of the second unit,
The main body casing protrudes into a slide operation area of the process cartridge that slides relative to the main body casing at two positions separated from each other in the slide direction of the process cartridge. With convex parts
The process cartridge has an engagement position that engages with the first protrusion when the process cartridge is pulled out to a predetermined pulling position and prevents further pulling of the process cartridge from the pulling position. A stopper member movable between the retracted position retracted from the engagement with the first convex portion, and a spring member for biasing the stopper member so that the stopper member is held at the engaging position; When the stopper member is in the engagement position, the stopper member is in a predetermined pre-operation state, and when the stopper member is in the retracted position, the stopper member is in a predetermined post-operation state. An operation member that moves to the retracted position, and an operation member that engages with the operation member in the post-operation state and overcomes the urging force of the spring member to hold the operation member in the post-operation state And a support member,
The operation member is further pulled out from the pull-out position while the stopper member is held at the retracted position by the operation member being held in the post-operation state by the operation member holding member. When the process cartridge is slidably accommodated in the main body housing, the operation member is released from engagement with the operation member holding member by contacting the second convex portion, and the operation is performed by the biasing force of the spring member. An image forming apparatus comprising: an abutting portion for returning the member to the pre-operation state and returning the stopper member to the engagement position on the rear side in the slide accommodating direction from the first convex portion . The image forming apparatus according to claim 1, wherein the photosensitive unit is the first unit, and the intermediate transfer unit is the second unit .

Images