JP5024281B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a belt unit facing a plurality of photosensitive drums.

  2. Description of the Related Art Conventionally, a plurality of process cartridges having photosensitive drums, a belt unit having a belt for conveying paper between the photosensitive drums, a paper feeding unit (supply unit) for supplying paper to the belt units, and a process cartridge are provided. An image forming apparatus including a front cover that opens and closes an opening for attaching to and detaching from a main body is known (see Patent Document 1). In this technology, the paper feed unit is arranged between the front cover and the belt unit. However, since the paper feed unit is fixed to the front cover, the paper feed unit is separated from the belt unit when the front cover is opened. The belt unit is exposed to the outside. Thereby, in order to perform maintenance (replacement, cleaning, etc.) of the belt unit, an operator can grasp the belt unit and take it out from the apparatus main body.

JP 2007-57953 A

  However, the conventional technique has a problem in that the paper feed unit is fixed to the front cover, which makes the front cover heavy and difficult to operate. Further, in order to solve this problem, when the paper feeding unit is fixed to the main body, there is a problem that it becomes difficult to take out the belt unit because the paper feeding unit located in front becomes an obstacle.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of improving the operability of a front cover (cover) and easily taking out a belt unit.

The present invention that solves the above-described problems includes a plurality of photosensitive drums on which an electrostatic latent image is formed, a belt unit having a belt facing each of the photosensitive drums, and the belt unit as viewed from the arrangement direction of the plurality of photosensitive drums. And a supply unit for supplying a recording sheet to the belt unit, and an opening for attaching / detaching the plurality of photosensitive drums and the belt unit to the photosensitive drum and the supply unit in the arrangement direction. An image forming apparatus comprising: an apparatus main body formed at an opposed position; and a cover provided on the opposite side of the belt unit across the supply unit and opening and closing the opening , wherein the supply unit includes: Separately from the cover, an approach position for supplying the recording sheet to the belt unit, and attaching / detaching the belt unit Configured to be movable to the separated position to form a space for, in the approach position, that the supply unit is disposed at a position off the detachable path of the photosensitive drum, the photosensitive drum is detachably mountable, The photosensitive drum and the belt unit are detachable by disposing the supply unit at a position away from the attachment / detachment path of the photosensitive drum and the belt unit at the separation position .

  According to the present invention, since the supply unit is provided separately from the cover, the cover can be lightened and the operability of the cover can be improved. Further, since the supply unit is configured to be movable between an approach position for supplying the recording sheet to the belt unit and a separation position for forming a space for attaching and detaching the belt unit, the supply unit is moved to the separation position. The belt unit can be gripped by using the space formed by this, and the belt unit can be easily taken out.

  According to the present invention, since the supply unit can be moved to the approach position and the separation position with respect to the belt unit separately from the cover, the operability of the cover can be improved, and the supply unit is appropriately separated from the belt unit. Can be easily taken out.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is an explanatory diagram showing the overall configuration of a color printer as an example of an image forming apparatus.

  In the following description, the direction will be described with reference to the user when using the color printer. That is, in FIG. 1, the right side toward the paper surface is “front side (front side)”, the left side toward the paper surface is “rear side (back side)”, and the back side in the direction orthogonal to the paper surface is “right side”. The front side in the direction perpendicular to the direction is the “left side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

  As shown in FIG. 1, a color printer 1 includes a paper feed tray 2, a paper feed unit 3 as an example of a supply unit, a scanner unit 4, a plurality of process cartridges 5, a belt unit 6, and a fixing device 7. And is mainly configured.

  The scanner unit 4, the plurality of process cartridges 5, the belt unit 6, and the paper feed tray 2 are sequentially arranged from the top to the bottom, and the paper feed unit 3 is disposed in front of the belt unit 6 and above the front end portion of the paper feed tray 2. A fixing device 7 is disposed behind the belt unit 6. An opening 12C for attaching / detaching the process cartridge 5 corresponding to the front of the process cartridge 5 and a sheet corresponding to the front of the paper feed tray 2 are provided on the front surface of the box-shaped apparatus main body 10 that accommodates them. An outlet 12B for attaching and detaching the tray 2 is formed, and a front cover 12 is provided in the opening 12C so as to be openable and closable.

  The paper feed tray 2 is a tray that stores paper P as an example of a recording sheet, and is detachable from the front side of the apparatus main body 10 in the front-rear direction with respect to the apparatus main body 10.

  The paper feed unit 3 is a device that supplies the paper P in the paper feed tray 2 to the belt unit 6, a known paper feed roller 31 that contacts the paper P in the paper feed tray 2, and a belt described later of the belt unit 6. 6 is provided with a conveyance roller 32 positioned substantially on the same plane as the upper surface of 6, a guide path 3 </ b> A for guiding the paper from the paper supply roller 31 to the conveyance roller 32, and the like. The sheet feeding unit 3 is arranged at a position overlapping the belt unit 6 when viewed from the front-rear direction (arrangement direction of the plurality of photosensitive drums 51), specifically, at a position before the belt unit 6. The transport roller 32 preferably has a function of a registration roller as an example of a front end aligning member for aligning the front end position of the paper P.

  The sheet feeding unit 3 is rotatably provided by a rotation shaft 33 having a rotation center extending horizontally in the left-right direction between a pair of side frames 11 (main body frames) constituting the left and right walls of the apparatus main body 10. It has been. In other words, the paper feeding unit 3 is located at the approach position where the paper P is supplied to the belt unit 6 and in front of the belt unit 6, separately from the front cover 12 (cover) that is rotatably provided on the front side of the apparatus body 10. It is configured to be movable to a separation position that forms a space A (see FIG. 3) for attachment / detachment.

  When the sheet feeding unit 3 provided to be rotatable with respect to the side frame 11 is moved to the approach position, the sheet feeding unit 3 comes into contact with a part of each side frame 11 and is positioned with respect to the side frame 11. Then, the sheet feeding unit 3 bridges between the side frames 11 and is attached to each side frame by a known fastening means, whereby the pair of side frames 11 are reinforced by the sheet feeding unit 3.

  Further, the rotation shaft 33 (rotation center) of the sheet feeding unit 3 is disposed below the lower surface of the belt unit 6. As a result, when the paper feeding unit 3 is rotated to the lower side of the lower surface of the belt unit 6, the entire paper feeding unit 3 including the rotation shaft 33 is positioned below the lower surface of the belt unit 6. 6 can be pulled out in the horizontal direction (see FIG. 3).

  The scanner unit 4 has a known structure mainly including a laser light emitting unit, a polygon mirror, a lens, and a reflecting mirror (not shown). The scanner unit 4 irradiates the surface of a photosensitive drum 51 of each process cartridge 5 to be described later with high-speed scanning.

  Each process cartridge 5 includes a photosensitive drum 51 on which an electrostatic latent image is formed, and a known charger, a toner storage chamber, a supply roller, a developing roller, and the like (not shown). The process cartridges 5 are integrally supported by a drawer 8 as an example of a photosensitive drum holding member in a state where the process cartridges 5 are arranged in the front and rear direction. The drawer 8 is supported on a pair of side frames 11 by a known guide rail (not shown) so as to be movable back and forth, and can be pulled out from an opening 12C (see FIG. 2) formed by opening the front cover 12. ing.

  In the process cartridge 5, first, the photosensitive drum 51 charged by the charger is exposed to the laser light emitted from the scanner unit 4, thereby forming an electrostatic latent image on the surface of the photosensitive drum 51. . Thereafter, the toner (developer) in the toner storage chamber is supplied to the electrostatic latent image on the photosensitive drum 51 via a supply roller or the like, and the toner image (developer image) is carried on the photosensitive drum 51.

  The belt unit 6 supports an endless belt 61 facing each photosensitive drum 51, a driving roller 62 and a driven roller 63 for rotating the belt 61 while stretching the belt 61, and rotatably supporting these rollers 62 and 63. And a frame (not shown). The belt unit 6 is disposed between each photosensitive drum 51 and the paper feed tray 2 and is supported by a pair of side frames 11 so as to be movable back and forth by a known support member (not shown). The drawer 8 and the belt unit 6 can be moved back and forth, but are held stationary at the image forming operation position in the apparatus main body 10.

  In the belt unit 6, the paper P can be conveyed between the belt 61 and each photosensitive drum 51. During the conveyance, the toner images on the respective photosensitive drums 51 are attracted by a plurality of transfer rollers (not shown) arranged inside the belt 61, so that the toner images are transferred onto the paper P. ing.

  The fixing device 7 is a device that heat-fixes the toner image transferred onto the paper P, and includes a known heating roller 71, pressure roller 72, and the like. Then, the paper P thermally fixed by the fixing device 7 is discharged to the outside of the apparatus main body 10 by a conveyance roller (not shown).

<Removal method of belt unit>
Next, a method for attaching and detaching the belt unit 6 will be described. In the drawings to be referred to, FIG. 2 is an explanatory view showing an operation of removing the drawer from the apparatus main body, FIG. 3 is an explanatory view showing an operation of separating the paper feeding unit from the belt unit, and FIG. 4 is an explanatory view of the belt unit. It is explanatory drawing which shows the operation | movement removed from.

  As shown in FIG. 2, when removing the belt unit 6 from the apparatus main body 10, an operator (user, repairman, etc.) first opens the front cover 12, and the drawer 8 is opened to the opening 12 </ b> C of the apparatus main body 10. Remove through. At this time, as shown by an arrow in FIG. 2, the drawer 8 is pulled upward and pulled forward along the guide rail so that the photosensitive drum 51 is separated from the belt 61 upward. Since the operator only has to open the light front cover 12 on which the paper feeding unit 3 is not fixed integrally, the worker can easily perform the work without feeling a burden. Thereafter, as shown in FIG. 3, the worker tilts the paper feed unit 3 toward the front and exposes the front portion of the belt unit 6 to the worker side.

  Then, as shown in FIG. 4, the operator removes the belt unit 6 through the space in which the paper feeding unit 3 has disappeared by holding the exposed front portion (for example, a handle) of the belt unit 6 and pulling it forward. When the belt unit 6 is attached to the apparatus main body 10, the above-described operation may be performed in reverse.

According to the above, the following effects can be obtained in the present embodiment.
Since the paper feed unit 3 can be moved to the approach position and the separation position with respect to the belt unit 6 separately from the front cover 12, the operability of the front cover 12 can be improved, and the paper feed unit 3 is appropriately separated. Thus, the belt unit 6 can be easily taken out.

  Since the paper feed unit 3 is positioned with respect to the side frame 11, positioning of the conventional front cover with respect to the side frame also positions the paper feed unit that is indirectly fixed integrally to the front cover. Compared to the structure, the paper feeding unit 3 can be accurately positioned with respect to the side frame 11 and the belt unit 6.

  By providing the sheet feeding unit 3 positioned in the apparatus main body 10 with the conveyance roller 32 having the function of a registration roller, the leading edge of the sheet P can be effectively aligned with the photosensitive drum 51.

  Since the paper feed unit 3 is provided so as to be rotatable with respect to the side frame 11, for example, the loss of the paper feed unit 3 can be prevented as compared with an embodiment in which the paper feed unit can be separated from the side frame. it can.

  Since the rotation shaft 33 of the paper supply unit 3 is disposed below the lower surface of the belt unit 6, the rotation shaft 33 is moved when the paper supply unit 3 is rotated below the lower surface of the belt unit 6. The entire sheet feeding unit 3 including the belt unit 6 is positioned below the lower surface of the belt unit 6 so that the belt unit 6 can be pulled out in the horizontal direction.

  Since the drawer 8 and the belt unit 6 can be taken out from the opening 12C formed by opening the front cover 12, both the drawer 8 and the belt unit 6 can be taken out from the front side. Can be easily.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above embodiment, the belt unit 6 cannot be detached from the apparatus main body 10 unless the drawer 8 is detached from the apparatus main body 10. However, the present invention is not limited to this, and the belt is left in the apparatus main body while remaining in the apparatus main body. The unit may be detachable from the apparatus main body. Specifically, for example, a structure as shown in FIG. 5 may be adopted.

  In the form shown in FIG. 5, a rotation shaft 81 is provided at the lower rear portion of the drawer 8, and the drawer 8 can rotate with respect to the side frame 11 around the rotation shaft 81. Further, a protrusion 82 protruding outward in the left-right direction is formed at the front lower portion of the drawer 8, and the protrusion 82 is pushed up by a pressing mechanism 9 provided on the side frame 11.

  The pressing mechanism 9 includes a contact member 91 that contacts the protrusion 82 from below, and a coil spring 92 that biases the contact member 91 upward. Instead of the coil spring 92, another biasing member such as a plate spring or a torsion spring may be employed.

  The abutting member 91 is a bottomed cylindrical member disposed with the opening facing downward, and an upper surface 91A thereof faces the protrusion 82 in the vertical direction. Further, a part of the front upper portion of the abutting member 91 is notched, whereby the engaging surface 91B pressed by the engaging claw 34 of the paper feeding unit 3 is located at a position lower than the upper surface 91A. Is formed. Here, the engaging claw 34 is formed so as to protrude rearward from the rear surface of the paper feeding unit 3.

  The coil spring 92 is disposed inside the abutting member 91 and is held in a contracted state by a predetermined amount when the engagement surface 91B is pressed by the engagement claw 34. Therefore, as shown in FIG. 6, when the sheet feeding unit 3 is tilted toward the front side, the engaging claw 34 is detached from the engaging surface 91 </ b> B, and the contact member 91 is raised by the restoring force of the coil spring 92. Accordingly, the protrusion 82 is pushed upward by the contact member 91, the drawer 8 is tilted upward, and each photosensitive drum 51 is separated from the belt unit 6. That is, each photosensitive drum 51 is separated from the belt unit 6 in conjunction with the operation of separating the sheet feeding unit 3 from the belt unit 6.

  Thereafter, as shown in FIG. 7, if the belt unit 6 is pulled out horizontally, the belt unit 6 can be taken out without sliding contact with the respective photosensitive drums 51. Further, when the belt unit 6 is attached to the apparatus main body 10, the belt unit 6 can be attached to the attachment position (position of FIG. 5) without being in sliding contact with each photosensitive drum 51. After that, the engaging surface 91B and the engaging claw 34 may be engaged again by returning the sheet feeding unit 3 to the original position while pushing down the front portion of the drawer 8 tilted upward.

  As described above, according to the embodiment shown in FIG. 5, the belt unit 6 can be taken out without removing the drawer 8, so that the maintenance work of the belt unit 6 can be facilitated. In addition to the configuration shown in FIG. 5, the belt unit may be configured to move away from each photosensitive drum in conjunction with the operation of separating the paper feeding unit from the belt unit.

  In the above embodiment, the paper feed unit 3 is provided so as to be rotatable with respect to the side frame 11. However, the present invention is not limited to this, and it is sufficient that the paper feed unit is movable with respect to the side frame. The paper feeding unit may be detachably attached to the side frame. In this case, the feeding unit and the belt unit may be taken out integrally.

  In the above-described embodiment, the sheet feeding unit 3 is positioned by contacting the side frame 11, but the present invention is not limited to this, and the sheet feeding unit 3 may be positioned by contacting a part other than the side frame, for example, a belt unit. Good.

  In the above-described embodiment, the entire paper feeding unit 3 is configured to be rotatable to a position below the lower surface of the belt unit 6. However, the present invention is not limited to this, and at least between the belt unit and the paper feeding unit. The amount of rotation may be small as long as a space for inserting a finger or jig can be secured. In this case, the belt unit 6 is pulled up obliquely upward by lifting the front end.

In the above-described embodiment, the conveyance roller (registration roller) 32 is used as the leading edge aligning member. However, the present invention is not limited to this, for example, after contacting the plural positions of the leading edge of the recording sheet and aligning the leading edge position. A plurality of plate members that retreat from the recording sheet conveyance path may be employed.
In the above-described embodiment, the process unit 5 is raised with respect to the belt unit 6 and separated from the belt unit 6. However, the present invention is not limited to this, and the belt unit 6 may be lowered.
In the above-described embodiment, the plurality of process units 5 and the belt unit 6 are arranged horizontally. However, the present invention is not limited to this, and the process unit 5 and the belt unit 6 are arranged in the vertical direction. May be arranged.

In the above embodiment, the present invention is applied to the color printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.
In the above-described embodiment, paper P such as thick paper, postcard, and thin paper is used as an example of the recording sheet. However, the present invention is not limited to this, and may be, for example, an OHP sheet.

1 is an explanatory diagram illustrating an overall configuration of a color printer as an example of an image forming apparatus. FIG. It is explanatory drawing which shows the operation | movement which removes a drawer from an apparatus main body. FIG. 10 is an explanatory diagram illustrating an operation of separating the paper feeding unit from the belt unit. It is explanatory drawing which shows the operation | movement which removes a belt unit from an apparatus main body. It is explanatory drawing which shows the form provided with the press mechanism which pushes up a drawer upwards as other embodiment. FIG. 6 is an explanatory diagram illustrating a state where the sheet feeding unit is tilted forward in the form of FIG. 5. FIG. 6 is an explanatory view showing a state in which the belt unit is pulled out to the front in the embodiment of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color printer 3 Paper feeding unit 6 Belt unit 10 Apparatus main body 11 Side frame 12 Front cover 12C Opening part 32 Conveyance roller 33 Rotating shaft 51 Photosensitive drum 61 Belt P Paper

Claims (7)

A plurality of photosensitive drums on which electrostatic latent images are formed;
A belt unit having a belt facing each photosensitive drum;
A supply unit that is disposed so as to overlap the belt unit when viewed from the arrangement direction of the plurality of photosensitive drums, and that supplies a recording sheet to the belt unit;
An apparatus body in which openings for attaching and detaching the plurality of photosensitive drums and the belt unit are formed at positions facing the photosensitive drums and the supply unit in the arrangement direction;
An image forming apparatus provided with a cover that is provided on the opposite side of the belt unit across the supply unit and that opens and closes the opening ,
Separately from the cover, the supply unit is configured to be movable between an approach position for supplying the recording sheet to the belt unit and a separation position for forming a space for attaching and detaching the belt unit .
In the approach position, the photosensitive drum can be attached and detached by disposing the supply unit at a position away from the attachment and detachment path of the photosensitive drum.
The image is characterized in that the photosensitive drum and the belt unit are detachable by disposing the supply unit at a position away from the attachment / detachment path of the photosensitive drum and the belt unit at the separation position. Forming equipment.   The image forming apparatus according to claim 1, wherein the supply unit is positioned with respect to a main body frame that supports the belt unit when the supply unit moves to the approach position.   The image forming apparatus according to claim 2, wherein the supply unit includes a leading end aligning member for aligning a leading end position of the recording sheet.   The image forming apparatus according to claim 3, wherein the supply unit is configured to be rotatable with respect to the main body frame so as to be movable between the approach position and the separation position.   The image forming apparatus according to claim 4, wherein a rotation center of the supply unit is disposed below a lower surface of the belt unit. A photosensitive drum holding member that holds the plurality of photosensitive drums and can be pulled out from the apparatus main body;
The image forming apparatus according to claim 1, wherein the photosensitive drum holding member and the belt unit can be taken out from the opening .   7. The structure according to claim 1, wherein the photosensitive drum and the belt unit are separated in conjunction with an operation of separating the supply unit from the belt unit. The image forming apparatus described in 1.

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