JP4835671B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus that forms an image on a recording medium. More specifically, the present invention relates to a process for forming an image corresponding to an electrostatic latent image on each recording medium. The present invention relates to an image forming apparatus including a plurality of cartridges.

  Conventionally, a plurality of recording media arranged along a conveyance path of a recording medium, each having a photoconductor, and an image corresponding to an electrostatic latent image carried on the photoconductor is conveyed on the conveyance path There is considered an image forming apparatus including a process cartridge to be formed on the substrate and an exposure unit that individually exposes the photosensitive member of each of the process cartridges to form the electrostatic latent image. In the image forming apparatus configured as described above, when an electrostatic latent image is formed on the photosensitive member provided in each of the plurality of process cartridges by the exposure unit, an image corresponding to each electrostatic latent image is displayed on the transport path. It can be formed over the recording medium to be conveyed.

In this type of image forming apparatus, the process cartridge may be replaced or the developer may be replenished with a developer as necessary. In view of this, it has also been proposed that a plurality of the process cartridges can be pulled out from the housing of the apparatus while being arranged. However, if the process cartridge is to be pulled out in this way, supply means such as various rollers for supplying the recording medium may be disposed in the drawing direction toward the position facing the process cartridge. . Accordingly, it has been proposed that when the front cover provided on the front surface of the image forming apparatus is opened, the supply means is moved integrally with the front cover and retracted from the front surface (drawing direction) of the process cartridge ( For example, see Patent Document 1).
JP 2007-169024 A

  However, if the entire supply means overlapping the drawing direction of the process cartridge can be opened and closed integrally with the front cover, the front cover becomes heavy and the operability when replacing the process cartridge is lowered. Further, the structure is complicated in order to open and close the entire supply means integrally with the front cover, and the structure is further complicated if a mechanism for assisting the operation of the front cover is provided. SUMMARY OF THE INVENTION The present invention has been made with the object of providing an image forming apparatus having a simple configuration and capable of exchanging a process cartridge with a small force.

  The image forming apparatus of the present invention, which has been made to achieve the above object, is arranged in a plurality along the conveyance path of the recording medium, and each has a photoconductor and corresponds to an electrostatic latent image carried on the photoconductor. A process cartridge that forms an image to be recorded on a recording medium that is conveyed along the conveyance path, an exposure unit that individually exposes the photosensitive member of each process cartridge to form the electrostatic latent image, and the process cartridge. A supply means for supplying the recording medium toward the opposite position, a housing for housing the process cartridges, the exposure means, and the supply means, and a plurality of the process cartridges arranged in an array. A process supporting means that is detachably supported, and supports the exposure means and the process supporting means, and the supply means is arranged in the arrangement direction of the process cartridges. It can be swung from a position where the image can be formed on the recording medium to an angle at which it is not folded, and at the time of swinging, the process support means can be pulled out of the housing along the process cartridge arrangement direction. And an image forming unit supporting unit.

  In the present invention configured as described above, the plurality of process cartridges that form images on the recording medium supplied by the supplying unit via the photosensitive member are arranged along the conveyance path of the recording medium. Each process support means is detachably supported. The process support means is supported by the image forming portion support means together with the exposure means for individually exposing each of the photosensitive members. The image forming unit support means can be swung to an angle at which the supply means does not overlap in the arrangement direction of the process cartridges. At the time of the swing, the process support means is placed in a housing that houses the exposure means and the supply means. It is configured to be able to be pulled out of the body along the arrangement direction of the process cartridges.

  In the image forming apparatus of the present invention, the process support means can be pulled out by swinging the image forming unit support means for supporting the process support means in this way. It becomes exchangeable. In addition, since the image forming unit support unit supports the exposure unit as well as the process support unit, the positional relationship between the exposure unit and the process cartridge can be accurately maintained even if the image forming unit support unit is swung. It can also be suppressed that the accuracy of formation decreases.

  Although the present invention is not limited to the following configuration, after the process support means is pulled out of the housing, the process support means is arranged so that the process cartridges are arranged in the horizontal direction. You may further provide the guide means to guide. In this case, when the process support means is pulled out of the housing, the process support means is guided by the guide means so that the process cartridges are arranged horizontally. This makes it easier to replace the process cartridge.

  Further, the image forming unit support means may swing integrally with the discharge tray on which the recording medium after the image formation is stacked, toward the stacking surface side of the discharge tray. It is necessary to secure a space for taking out the recording medium above the discharge tray on which the recording medium after image formation is stacked. Therefore, when such a configuration is employed, the space for installing the apparatus can be reduced by using the space to swing the image forming unit support means when replacing the process cartridge.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view showing a schematic configuration of a multifunction machine 1 to which the present invention is applied. In the following description, the right side in FIG. 1 is the front side, and the near side in FIG. 1 is the left side.

(Overall configuration of MFP)
As shown in FIG. 1, the multifunction machine 1 includes an image reading device 90 on the upper portion of the image forming apparatus 10. The image reading device 90 is a well-known device having a flat bed and a line scanner, and since it has little relation to the present invention, description thereof is omitted.

  The image forming apparatus 10 is a direct transfer tandem color printer, and includes a substantially box-shaped casing 11 as shown in FIG. On the upper surface of the housing 11, a paper discharge tray 12 is formed as an example of a paper discharge tray on which paper P as a recording medium after image formation is stacked. The above-described image reading device 90 is disposed further above the paper discharge tray 12. Between the paper discharge tray 12 and the image reading device 90, a sheet P after image formation is taken out. Space is secured. Furthermore, a front cover 11A that covers the front surface of the housing 11 is provided so as to be openable and closable around the lower front end of the multifunction machine 1. By opening the front cover 11A, a process cartridge 30 described later can be pulled forward from the inside of the housing 11.

  A paper feed tray 13 that accommodates paper P for forming an image is attached to the lower portion of the housing 11 so as to be able to be pulled forward. The paper P stored in the paper feed tray 13 is separated one by one by the pickup roller 14 and the separation pad 15 and then sent to the registration roller 17 by the paper feed roller 16. The registration roller 17 feeds the paper P onto the rear belt unit 20 through a paper entry guide 18 that is convexly curved upward at a predetermined timing. A series of components from the pickup roller 14 to the paper entry guide 18 corresponds to the supply unit.

  The belt unit 20 includes a conveyor belt 23 that is horizontally installed between a driving roller 21 and a tension roller 22 that are spaced apart from each other in the front-rear direction. The transport belt 23 is a semiconductive endless belt (transfer belt) made of a resin material such as polycarbonate, and the drive roller 21 on the rear side is driven to rotate by a main motor (not shown), and the reverse of FIG. The paper P, which is driven to rotate in the clockwise direction, is transported backward. The tension roller 22 is provided with the drive roller 21 and the rotation axis aligned in parallel, and applies an appropriate tension to the conveyor belt 23.

(Configuration of image forming unit)
Inside the conveyor belt 23, four transfer rollers 24 arranged to be opposed to respective photosensitive drums 31 included in a process cartridge 30 described later are provided side by side at regular intervals in the front-rear direction, and correspond to the respective photosensitive drums 31. The conveyance belt 23 is sandwiched between the transfer roller 24 and the transfer roller 24. At the time of transferring a toner image, which will be described later, a transfer bias is applied between the transfer roller 24 and the photosensitive drum 31, and a predetermined amount of transfer current is applied. A well-known belt cleaner 40 that removes toner, paper dust, and the like attached to the conveyance belt 23 via a cleaning roller 41 is provided below the belt unit 20.

  Four process cartridges 30 are provided corresponding to the respective colors in the order of black, yellow, magenta, and cyan in order from the upstream side in the paper conveyance direction. Also, above each process cartridge 30, a scanner unit 50 as an example of an exposure unit that incorporates a polygon mirror (not shown) or the like and performs scanning exposure of each photosensitive drum 31 with a laser beam is disposed.

  Each process cartridge 30 includes a photoconductor drum 31 as an example of a photoconductor, a scorotron charger 32, a developing cartridge 34, and the like. The photoconductor drum 31 includes a grounded metal drum body, and the surface layer thereof is covered with a positively chargeable photoconductive layer made of polycarbonate or the like. The scorotron charger 32 is disposed opposite to the photosensitive drum 31 at a predetermined interval so as not to come into contact with the photosensitive drum 31 in the diagonally upper rear side of the photosensitive drum 31. The scorotron charger 32 uniformly charges the surface of the photosensitive drum 31 to positive polarity by generating corona discharge from a charging wire such as tungsten.

  The developing cartridge 34 has a substantially box shape, and a toner storage chamber 35 is provided in an upper portion thereof, and a supply roller 36, a developing roller 37, and a layer thickness regulating blade 38 are provided below the developing cartridge 34. . The toner storage chamber 35 of each developing cartridge 34 stores positively chargeable nonmagnetic one-component toner of each color of black, cyan, magenta, or yellow as a developer.

  The toner discharged from the toner storage chamber 35 is supplied to the developing roller 37 by the rotation of the supply roller 36, and is positively frictionally charged between the supply roller 36 and the developing roller 37. Further, the toner supplied onto the developing roller 37 enters between the layer thickness regulating blade 38 and the developing roller 37 with the rotation of the developing roller 37, and is further sufficiently frictionally charged here to have a constant thickness. It is carried on the developing roller 37 as a thin layer.

  The surface of the photosensitive drum 31 is first uniformly charged positively by the scorotron charger 32 when rotating. Thereafter, an electrostatic latent image corresponding to an image to be formed on the paper P is formed on the surface of each photosensitive drum 31 by scanning exposure with a laser beam from the scanner unit 50.

  Next, when the developing roller 37 rotates and the positively charged toner carried on the developing roller 37 comes into contact with and faces the photosensitive drum 31, a static image formed on the surface of the photosensitive drum 31 is formed. The electric latent image is supplied. As a result, the electrostatic latent image on the photosensitive drum 31 is visualized, and a toner image with toner attached only to the exposed portion is carried on the surface of the photosensitive drum 31.

  Thereafter, the toner image carried on the surface of each photosensitive drum 31 is transferred to the sheet P by the transfer current when the sheet P conveyed by the conveying belt 23 passes between the photosensitive drum 31 and the transfer roller 24. Are sequentially transferred. The paper P on which the toner images of the respective colors are sequentially transferred in this manner is then conveyed to a fixing device 60 as an example of fixing means.

  The fixing device 60 is disposed behind the conveyance belt 23 in the housing 11. The fixing device 60 includes a heating roller 61 that is rotationally driven with a heat source such as a halogen lamp, and a pressure roller 62 that is disposed below the heating roller 61 so as to face the heating roller 61 and is driven to rotate. It has. The fixing device 60 fixes the toner image on the paper P by heating the paper P on which the toner images of the respective colors are transferred while being nipped and conveyed by the heating roller 61 and the pressure roller 62. Then, the sheet P on which the toner image is fixed is further conveyed by a conveyance roller 63 disposed obliquely above and behind the fixing device 60, and is discharged by the paper discharge roller 64 provided at the upper part of the housing 11. The paper is discharged onto the paper tray 12.

(Structure of drawer unit support structure)
Further, as shown in FIG. 1, each process cartridge 30 is detachably supported in a drawer unit 70 (an example of process support means) that can be pulled out from the housing 11 in a state of being arranged as described above. Next, a drawer unit support structure that supports the drawer unit 70 so that it can be pulled out into the housing 11 will be described.

  As shown in FIG. 2, a pair of side plates 80 as an example of an image forming unit supporting unit arranged vertically are fixed to the left and right side surfaces of the scanner unit 50 and the left and right end edges of the paper discharge tray 12. The pair of side plates 80 are substantially symmetrical. Therefore, FIG. 2 schematically shows a configuration on the right side (the back side in FIG. 2) from the guides 81 and 82 provided on the side plate 80 on the left side (the near side in FIG. 2).

  As shown in FIG. 2 and FIG. 4 to be described later, the side plate 80 is configured to be swingable around a shaft 83 provided in the left and right direction at the lower rear end thereof. The prismatic guides 81 and 82 parallel to the direction are provided side by side. A first roller 71 that contacts the lower guide 81 from above and a second roller 72 that contacts the upper guide 82 from below are rotatably provided behind the upper left and right side surfaces of the drawer unit 70. ing. Further, a flange 75 projecting outward in the left-right direction is formed at the upper edge of the left and right side surfaces of the drawer unit 70, and this flange 75 contacts the stopper / roller 85 rotatably provided at the front end of the side plate 80 from above. It touches. The front end of the flange 75 has an outer edge 75A bent upward.

  Therefore, as shown in FIG. 3, when the side plate 80 is swung around the shaft 83, the drawer unit 70 swings integrally with the side plate 80. The side plate 80 is configured to swing in conjunction with the opening and closing of the front cover 11A. This configuration will be described later.

  When the front cover 11A is opened and the side plate 80 is swung to the position shown in FIG. 3, the paper entry guide 18 and the like do not overlap in the arrangement direction of the process cartridges 30. Therefore, from this state, the drawer unit 70 can be pulled out of the casing 11 along the guides 81 and 82 as shown in FIG. The drawing out of the drawer unit 70 is stopped when the first roller 71 comes into contact with the stopper / roller 85, and the user is prevented from pulling out the drawer unit 70 at once and dropping it onto the floor.

  In addition, an inclined surface 82A (an example of guide means) is formed at the front end of the guide 82. Therefore, when the second roller 72 is brought into contact with the inclined surface 82A after the first roller 71 is brought into contact with the stopper / roller 85, the drawer unit 70 is kept horizontal as shown in FIG. In this state, since the process cartridge 30 is exposed from the housing 11 and arranged horizontally, the process cartridge 30 can be easily replaced. Further, when the front end of the drawer unit 70 is pulled up from this state as shown by a two-dot chain line in FIG. 5, the engagement between the first roller 71 and the stopper / roller 85 is released, and the drawer unit 70 is removed from the multifunction device 1. Can be removed.

(Swing mechanism of side plate)
Next, a configuration for swinging the side plate 80 in conjunction with opening and closing of the front cover 11A will be described. As shown in FIG. 6, a side frame (not shown) that supports the side plate 80 from the left and right is formed with a slider guide groove 86 extending in the front-rear direction. The slider guide groove 86 has a slider 87 in the front-rear direction. It is slidably mounted. The slider 87 is connected to the front cover 11A via a link 88, and moves forward and backward in conjunction with opening and closing of the front cover 11A. Further, the slider 87 is provided with a cam 87A whose rear side is raised, and the side plate 80 is provided with a cam follower 89 that comes into contact with the cam 87A.

  As shown in FIG. 6, when the front cover 11 </ b> A is closed, the cam 87 </ b> A is disposed behind the cam follower 89, so that the side plate 80 is lowered and each photosensitive drum 31 contacts the transport belt 23. (Refer to FIG. 2). On the other hand, when the front cover 11A is opened, the slider 87 moves forward, and the cam follower 89 rides on the cam 87A as shown in FIG. Therefore, the front side of the side plate 80 swings upward about the shaft 83, and the drawer unit 70 can be pulled out as described above. At this time, the side plate 80 uses a space secured between the image forming apparatus 10 and the image reading apparatus 90 to take out the paper P after image formation, and the paper discharge tray 12 advances into the space. Oscillate to For this reason, it is not necessary to prepare a space for swinging the side plate 80, and the apparatus can be downsized.

(Effect of this embodiment and its modification)
As described above, in the multifunction device 1 according to the present embodiment, the drawer unit 70 can be pulled out by swinging the side plate 80, so that the process cartridge 30 can be replaced with a small force with a simple configuration. In addition, since the scanner unit 50 is supported together with the drawer unit 70 on the side plate 80, the positional relationship between the scanner unit 50 and the process cartridge 30 is accurately maintained even when the side plate 80 is swung, and the accuracy of image formation is maintained. Can also be suppressed. Further, the drawer unit 70 also swings integrally with the side plate 80, and the photosensitive drum 31 and the transport belt 23 are isolated, so that it may be possible to perform jam processing only by swinging the side plate 80.

  In addition, this invention is not limited to the said embodiment at all, It can implement with a various form in the range which does not deviate from the summary of this invention. For example, as in the multifunction machine 101 shown in FIG. 8, the side plate 180 may be swung around a shaft 183 provided at the upper rear end. In this case, the same operation and effect as in the above-described embodiment occur. . Since the multifunction machine 101 is configured in the same manner as the multifunction machine 1 except for the side plate 180, the corresponding members are denoted by the same reference numerals as those of the multifunction machine 1 and detailed description of the configuration is omitted.

  Further, the registration roller 17 may be positioned higher than the upper surface of the conveyor belt 23. In this case, the drawer unit 70 is pulled out by avoiding the registration roller 17 by swinging the side plate 80 or 180 as described above. be able to. Furthermore, the present invention can also be applied to an image forming apparatus using a so-called intermediate transfer belt, in which case the intermediate transfer belt corresponds to a recording medium.

  Furthermore, various configurations other than the above can be considered as the configuration for swinging the side plate 80 or 180 in conjunction with opening and closing of the front cover 11A. For example, a lever may be protruded from the front cover 11A toward the inside of the housing 11, and the tip of the lever and the slider 87 may be connected so as to be relatively displaceable in the vertical direction but not to be relatively displaceable in the front-rear direction.

1 is a side sectional view showing a schematic configuration of a multifunction machine to which the present invention is applied. It is a sectional side view showing typically the drawer unit support structure of the compound machine. It is a sectional side view showing operation of the drawer unit support structure. It is a sectional side view showing the further operation | movement of the drawer unit support structure. It is a sectional side view showing the further operation | movement of the drawer unit support structure. It is side sectional drawing showing the structure of the rocking | fluctuation mechanism of the support structure. It is a sectional side view showing operation of the rocking mechanism. FIG. 6 is a side sectional view showing a schematic configuration of another multifunction machine to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Multi-function device 10 ... Image forming apparatus 11 ... Housing 11A ... Front cover 12 ... Paper discharge tray 13 ... Paper feed tray 14 ... Pickup roller 15 ... Separation pad 16: paper feed roller 17 ... registration roller 18 ... paper entry guide 20 ... belt unit 23 ... conveying belt 24 ... transfer roller 30 ... process cartridge 31 ...・ Photosensitive drum 32... Scorotron charger 34... Development cartridge 37 .. development roller 50 .. scanner unit 70... Drawer unit 71. 75 ... Flange 80, 180 ... Side plate 81, 82 ... Guide 82A ... Slope 83, 183 ... Shaft 85 ... Stopper / roller 86 ... Sly Guide groove 87 ... Slider 87A ... Cam 88 ... Link 89 ... Cam follower P ... Paper

Claims (3)

A plurality of images are arranged along the transport path of the recording medium, each having a photoconductor, and an image corresponding to the electrostatic latent image carried on the photoconductor is formed on the recording medium transported through the transport path. A process cartridge;
Exposure means for individually exposing the photoreceptor of each of the process cartridges to form the electrostatic latent image;
Supply means for supplying the recording medium toward a position facing the process cartridge;
A housing that accommodates each of the process cartridges, the exposure unit, and the supply unit;
Process support means for detachably supporting each of the process cartridges in an arrayed state;
The exposure unit and the process support unit are supported, and can swing from a position where the image can be formed on the recording medium up to an angle at which the supply unit does not overlap with the process cartridge arrangement direction. An image forming unit supporting unit configured to be sometimes pulled out of the casing along the direction in which the process cartridges are arranged;
An image forming apparatus comprising: After the process support means is pulled out of the housing, guide means for guiding the process support means so that the process cartridges are arranged in a horizontal direction,
The image forming apparatus according to claim 1, further comprising:   3. The image according to claim 1, wherein the image forming unit support means swings toward a stacking surface side of the discharge tray integrally with a discharge tray on which the recording medium after the image formation is stacked. Forming equipment.

Images