JP2006163379A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that interference with a fixation and discharge section in opening and closing operation of an opening and closing unit which opens and closes upward becomes large as an image forming apparatus is reduced in width. <P>SOLUTION: The image forming apparatus has: a first opening and closing unit that is opened to thereby expose a convey path for conveying a recording material; and a second opening and closing unit that has a stacking section for a recording material after fixation, supports an intermediate transfer body and open an image forming unit. The second opening and closing unit are operated to open or close when the first opening and closing unit is opened. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a full-color copying machine or printer that employs an electrophotographic system.

  In recent years, as a multi-color or full-color image forming apparatus using an electrophotographic system, a plurality of photosensitive drums 100 are arranged in a line for each color and formed on each photosensitive drum 100, as shown in FIG. The toner images of the respective colors are sequentially superimposed on the intermediate transfer belt 101 to form a color image, which is secondarily transferred to the conveyed sheet, and then heated and fixed by the fixing unit 102 and discharged to the discharge tray 103. A so-called inline type image forming apparatus is described in JP-A-2001-242680, JP-A-2003-202728, and JP-A-2004-85899. These arrangements in which the exposure device is arranged on the lower surface side shorten the moving distance from the transfer of the toner image from the image forming unit to the intermediate transfer member to the transfer of the toner image to the recording material. This configuration is effective for shortening the first copy time.

  In such an image forming apparatus, the image forming unit 100 and the intermediate transfer belt 101 have a shorter life than that of the main body of the image forming apparatus due to their properties. Therefore, replacement is necessary to achieve the main body life. . Therefore, as disclosed in Japanese Patent Application Laid-Open No. 2004-85899, as shown in FIG. 5B, the image forming unit 100 and the intermediate transfer belt 101 can be easily replaced. An upper door unit 103 having 101 is configured to be rotatable with respect to the image forming apparatus main body. As a result, both the image forming unit 100 and the intermediate transfer belt 101 can be freely accessed by rotating the upper door unit 104 upward (in the direction of arrow C in FIG. 5B). Therefore, maintainability is improved.

  On the other hand, in the image forming apparatus having the above configuration, in order to remove a jammed sheet in the sheet conveyance path, the unit having the sheet conveyance path is configured to be rotatable as the front door unit 104, and the sheet conveyance It is conceivable that the road can be opened.

JP 2001-242680 A JP 2003-202728 A JP 2004-85899 A

  However, in such a configuration, since the upper door unit supports the intermediate transfer belt, it is necessary to increase the open space by the upper door unit. In the configuration in which the recording material after fixing is stacked on the upper door unit, the distance between the upper door unit and the fixing discharge unit is shortened. Becomes larger.

  Further, if the distance between the upper door unit and the fixing discharge unit is made long so that only the upper door unit can be opened, the width of the image forming apparatus is increased.

  Therefore, it is necessary to reduce the interference with the fixing discharge unit when the upper door unit is opened without increasing the width of the image forming apparatus.

  SUMMARY OF THE INVENTION An object of the present invention is to reduce interference with a fixing discharge unit during an opening / closing operation of an opening / closing means that opens and closes without increasing the width of an image forming apparatus.

  An image forming unit having an image carrier, an intermediate transfer member disposed above the image forming unit, onto which a toner image formed by the image forming unit is transferred, and a toner image transferred from the intermediate transfer member to a recording material A fixing unit that fixes by heat, a recording material conveyance path that conveys the recording material toward the fixing unit via a transfer unit that transfers the toner image of the intermediate transfer member to the recording material, and the recording material conveyance path are opened. A first opening / closing means; a second opening / closing means that moves integrally with the intermediate transfer body to expose the intermediate transfer body; and at least a fixing unit, a first opening / closing means, and an image forming apparatus main body that supports the second opening / closing means. In the image forming apparatus, the fixing unit is supported by the image forming apparatus main body when the first opening / closing means and the second opening / closing means are opened.

  According to the present invention, it is possible to reduce the interference with the fixing discharge unit during the opening / closing operation of the opening / closing means that opens and closes without increasing the width of the image forming apparatus.

  Hereinafter, the present invention will be described more specifically with reference to embodiments. In addition, although these embodiment is an example of the best embodiment in this invention, this invention is not limited by these embodiment.

  Next, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

{Overall configuration of image forming apparatus}
First, the overall configuration of the image forming apparatus will be described with reference to FIG. FIG. 1 is a schematic sectional view of an image forming apparatus.

  The image forming apparatus shown in FIG. 1 includes four photosensitive drums 1 (1Y, 1M, 1C, 1K) that are image carriers that form toner images of yellow, magenta, cyan, and black. Around each photosensitive drum 1, a charger for charging the photosensitive drum 1, a developing unit for developing an electrostatic latent image formed by exposure, and a cleaning for cleaning toner on the photosensitive drum 1 after transfer Members are arranged and unitized as a process cartridge 2 (2Y, 2M, 2C, 2K) which is an image forming unit. An intermediate transfer belt 3 as an example of a belt body which is an intermediate transfer body is disposed above the process cartridge 2 so as to be in contact with each photosensitive drum 1.

  Below the process cartridge 2, there is provided an exposure means 4 for performing selective exposure by irradiating the photosensitive drum 1 with a laser according to an image signal.

  Each photoconductor drum 1 is charged by a charger, and the color separated yellow, magenta, cyan, and black light images are exposed by the exposure unit 4, and the photoconductor drum 1 is exposed to yellow, magenta, cyan, and black static images. An electrostatic latent image is formed. Each electrostatic latent image is developed by a developing device to form yellow, magenta, cyan, and black toner images on the photosensitive drum 1.

  As the photosensitive drum 1 rotates, the toner image reaches a primary transfer portion where the photosensitive drum 1 and the intermediate transfer belt 3 come into contact with each other. The toner images are sequentially transferred to the intermediate transfer belt 3 by primary transfer rollers 5 (5Y, 5M, 5C, 5K) disposed to face the respective photosensitive drums 1. A primary transfer bias is applied to the primary transfer roller 5 from an electrical board described later.

  In synchronization with the image formation, the sheets (recording materials) stored in the feeding cassette 7 loaded in the lower part of the apparatus main body 6 are sent out one by one by the feeding roller 8, and the timing is adjusted by the registration roller 9. After that, the sheet is conveyed to the secondary transfer unit. In the secondary transfer portion, a secondary transfer roller 10 that constitutes a secondary transfer unit is in contact with the intermediate transfer belt 3 and is driven to rotate. When the sheet is conveyed to the secondary transfer portion, the toner image on the intermediate transfer belt 3 is collectively transferred onto the sheet by applying a bias to the secondary transfer roller 10.

  Thereafter, the sheet on which the toner image has been transferred is conveyed to a fixing means 11 comprising a heating roller 11a as an image heating member and a pressure roller 11b as a pressure member, where the toner image is received by receiving heat and pressure. It is fixed. As a result, the toner of each color is melted and mixed to form a full-color print image fixed on the sheet P, and then discharged to a discharge tray 13 which is a recording material stacking unit by a discharge roller pair 12 provided downstream of the fixing unit 11. Is done.

  In the image forming apparatus according to the present embodiment having the above-described configuration, the feeding cassette 7, the exposure unit 4, the process cartridge 2, the intermediate transfer belt 3, and the discharge tray 13 are arranged in this order from the lower side to the upper side of the apparatus body 6. . For this reason, a sheet conveyance path, which is a conveyance path, is formed so that the sheet is conveyed from below to above.

  In the apparatus main body 6, a fixed power source and a main electrical board that controls the entire image forming apparatus are arranged. This electrical board can be arranged in a space formed between the exposure means 4 and the feeding cassette 7.

  Further, the surface connecting the primary transfer portions, which are the opposed portions of the four photosensitive drums 1 and the intermediate transfer belt 3, is configured to be inclined with the secondary transfer portion side downward. In the present embodiment, the inclination angle is set to about 15 °, and accordingly, each process cartridge 2 and the exposure means 4 are also inclined at the same angle.

  In the image forming apparatus according to this embodiment, the right side in FIG. 1 is the front side of the apparatus, and the user performs various operations from the front side of the apparatus.

{Opening and closing part}
Next, an opening / closing part that can be opened and closed with respect to the apparatus main body 6 will be described.

  In the image forming apparatus according to the present embodiment, a front door unit 16 as a first opening / closing means is disposed on the front side of the apparatus body 6 as shown in FIG. The front door unit 16 can also be rotated around the support shaft 17 with respect to the apparatus main body, and the front side of the apparatus main body can be opened and closed by rotating.

  The front door unit 16 is provided with a secondary transfer roller 10 and a fixing unit 11. As shown in FIG. 2, when the front door unit 16 is opened, the sheet conveyance path is exposed, and a jammed sheet can be easily removed. It can be removed. Further, the support shaft 17 is disposed at the lower part of the apparatus main body 6, and when the upper part of the front door unit 16 is rotated and opened, the sheet conveying path is greatly opened.

  Further, an upper door unit 14 as a second opening / closing means is disposed on the upper part of the apparatus main body 6. The upper door unit 14 can be rotated about a support shaft 15 with respect to the apparatus main body 6, and the upper part of the apparatus main body can be opened and closed by rotating.

  An intermediate transfer unit in which the intermediate transfer belt 3 is unitized is attached to the upper door unit 14. For this reason, as shown in FIG. 2, when the upper door unit 14 is opened, the process cartridge 2 including the photosensitive drum 1 is exposed, and the process cartridge 2 can be replaced (removed). Further, since the intermediate transfer belt 3 disposed on the upper door unit 14 is also exposed, the replacement can be easily performed.

  Here, in the image forming apparatus of the present embodiment, the upper door unit 14 is configured to be opened only when the front door unit 16 is open.

  That is, as shown in FIG. 2, the upper door unit 14 is opened by rotating upwardly of the main body (in the direction of arrow A in the figure) around the support shaft 15. At this time, the upper portion of the front door unit 16 is configured to protrude to the upper door unit 14 side. In the present embodiment, the fixing unit 11 is disposed above the front door unit 16 and above the secondary transfer unit, and a portion of the fixing unit 11 protrudes toward the upper door unit 14 side. It is configured as follows.

  Accordingly, if the upper door unit 14 is opened with the front door unit 16 closed, the rotation trajectory of the upper door unit 14 interferes with the front door unit 16 in the range E indicated by the oblique lines in FIG. . On the other hand, when the front door unit 16 is opened in the direction of arrow B in FIG. 2, the interference is eliminated and the upper door unit 14 can be opened in the direction of arrow A.

  When closing the front door unit 16, the front door unit 16 is closed after the upper door unit 14 is closed, contrary to the case of opening.

  That is, in the image forming apparatus of the present embodiment, the upper door unit 14 can be opened and closed only when the front door unit 16 is in an open state.

  As described above, since the fixing unit 11 is disposed in the front door unit 16 different from the upper door unit 14, the upper door unit 14 can be easily opened and closed, and maintenance performance is not sacrificed.

  Further, as described above, the primary transfer surface can be inclined, and in the surplus space created below the exposure unit 4, which is the merit of the inclined arrangement, originally in the depth direction or the width direction of the image forming apparatus. By storing the various electrical boards that should be provided, the volume of the entire image forming apparatus can be reduced.

{Drive transmission configuration}
Next, the drive transmission configuration to the intermediate transfer belt 3 will be described.

  As shown in FIG. 1, the intermediate transfer belt 3 is supported by a driving roller 20, a driven roller 21, and a tension roller 22 disposed in the upper door unit 14, and a driving force is transmitted from the apparatus body 6 to the driving roller 20. It is possible to rotate.

  As shown in FIG. 3, the rotation support shaft 15 of the upper door unit 14 is provided on the side plate 23 of the apparatus main body 6 made of sheet metal, and the rotation shaft portion 20 a of the drive roller 20 is fitted. A U-shaped groove 24 is provided. That is, when the upper door unit 14 is closed, the rotation shaft portion 20a of the driving roller 20 is guided and abutted against the U-shaped groove 24, so that the positioning is reliably and accurately performed with respect to the side plate 23. .

  FIG. 4 is an explanatory diagram of a drive transmission configuration from the apparatus main body 6 to the intermediate transfer belt 3. As shown in FIG. 4, a driven gear 25 serving as a driven transmission portion is provided at the shaft end portion of the driving roller 20 of the intermediate transfer belt 3.

  Further, the apparatus main body 6 is provided with a drive gear 26 as a drive transmission portion that rotates by driving force transmitted from a drive source such as a motor, and a first drive transmission portion is formed. Even when the drive is transmitted from the drive source to the drive gear 26, the drive is directly transmitted from the motor rotation shaft to the drive gear 26, another drive gear is provided between the motor rotation shaft and the drive gear 26. You may be the composition which is. The drive gear 26 is positioned in the apparatus main body 6 by positioning the drive shaft 26a with high precision on the side plate 23. The drive gear 26 is always urged toward the side plate 23 (upward in FIG. 4) by a compression spring (not shown).

  Here, the U-shaped groove 24 for positioning the drive roller 20 and the drive shaft 26a for positioning the drive gear 26 are guaranteed the inter-axis distance L (see FIG. 3) with high accuracy on the side plate 23 which is the same component. . In FIG. 4, the distance L is shown as a distance L ′ projected on the top view.

  Further, as shown in FIG. 4, a retraction lever 27 is provided so as to be rotatable about a rotation shaft 27a. The retraction lever 27 is connected to the front door unit 16 by a link (not shown). When the front door unit 16 is closed with respect to the apparatus body 6, the front door unit 16 is located at the position shown in FIG. When it is open with respect to the apparatus main body, it is configured to be in the position shown in FIG.

  When the front door unit 16 is opened, the retracting lever 27 is pulled in the direction of the arrow X in FIG. 4 by a link (not shown), and the tip of the retracting lever 27 on the symmetric side with respect to the rotating shaft 27a is the drive gear. A flange 26b provided at the end of 26 is pressed against a spring (not shown). As a result, the drive gear 26 is slid in the direction of the rotation axis to the position where the engagement between the drive gear 26 and the driven gear 25 is released. As a result, drive transmission to the intermediate transfer belt 3 is interrupted.

  Conversely, when closing the front door unit 16, the retracting lever 27 returns to the position shown in FIG. 4A, and the drive gear 26 is pressed to the side plate 23 side by a spring (not shown) and slides to the position where it engages with the driven gear 25. Moving. As a result, both the gears 25 and 26 do not come into contact with each other, and drive is transmitted to the intermediate transfer belt 3.

  That is, the drive gear 26 on the apparatus main body side and the driven gear 25 on the intermediate transfer unit side are engaged and disengaged by the opening / closing operation of the front door unit 16. Therefore, regardless of the opening / closing operation of the upper door unit 14, the distance between the shafts is reliably ensured without hitting the tooth tips, and the drive is transmitted with high accuracy.

  As described above, the image forming apparatus according to the present exemplary embodiment realizes high-precision drive transmission in the unit dividing portion without sacrificing maintenance performance and jam handling performance to the intermediate transfer belt 3 and the process cartridge 2 that are consumable parts. Is possible. With this configuration, it is possible to reduce the load on the drive transmission portion of the intermediate transfer member accompanying the opening and closing operation of the upper cover that opens and closes integrally with the intermediate transfer member, thereby preventing damage.

  In FIG. 1, the right direction in the drawing has been described as the front side (front side) of the apparatus main body, but the front side of the apparatus may be set to either.

  Furthermore, in this embodiment, the inclination angle of the intermediate transfer unit is set to 15 °. However, the inclination angle is not limited to this angle. Depending on the height of the fixing unit 11, the size of the exposure unit 4, and the like as necessary. An optimum inclination angle can be selected. Further, the intermediate transfer unit may be arranged substantially horizontally without being inclined.

  Further, in the opening / closing operation of the upper door unit 14 and the front door unit 16, the rotation is performed in the present embodiment. However, the upper door unit 14 and the front door unit 16 may be configured to be opened / closed by sliding with respect to the apparatus main body 6.

  In the present embodiment, the fixing unit as the fixing unit is attached to the front door unit 16. However, if the fixing unit is integrated with the front door unit 16, the total weight of the front door unit 16 becomes large, which causes a problem that it is difficult to open and close the front door unit 16. Therefore, even if the upper door unit 14 and the front door unit 16 are opened, the fixing unit may remain in the image forming apparatus main body.

  According to the present invention, it is possible to reduce the interference with the fixing discharge unit during the opening / closing operation of the opening / closing means that opens and closes without increasing the width of the image forming apparatus.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the technical idea of the present invention.

1 is a cross-sectional explanatory diagram of an image forming apparatus. FIG. 3 is an explanatory cross-sectional view of the image forming apparatus in a state where an upper door unit and a front door unit are opened. It is an enlarged detail view of a unit transfer section between the upper door unit and the apparatus main body. FIG. 6 is an explanatory diagram of a drive transmission configuration to an intermediate transfer belt. It is a sectional side view of the image forming apparatus in a conventional example.

Explanation of symbols

2 ... Process cartridge 3 ... Intermediate transfer belt
11… Fixing means
14… Upper door unit
16… Front door unit

Claims (10)

An image forming unit that forms a toner image, an intermediate transfer member that carries the toner image transferred from the image forming unit, a conveyance path that conveys a recording material on which an image is formed by the toner image of the intermediate transfer member, A first opening / closing means for opening the conveying path; a fixing means for fixing an image on the recording material; and a recording material stacking portion on which the recording material after fixing is stacked, supporting the intermediate transfer member. In an image forming apparatus having a second opening and closing means for opening the image forming unit,
An image forming apparatus, wherein the second opening / closing means is capable of opening / closing when the first opening / closing means is opened. A first drive transmission unit provided in the image forming apparatus main body, having a motor and transmitting drive, and a second opening / closing means provided for driving to rotate the intermediate transfer member by engaging with the first drive transmission unit. 2. The drive transmission unit according to claim 1, wherein the first drive transmission unit and the second drive transmission unit are separated from each other in conjunction with the opening operation of the first opening / closing means. Image forming apparatus. The image forming apparatus according to claim 2, wherein the first drive transmission unit and the second drive transmission unit that are separated from each other are engaged with each other in conjunction with the closing operation of the first opening / closing means. The gear engaged with the second drive transmission portion of the first drive transmission portion slides in the rotation axis direction of the first drive transmission portion in conjunction with the opening / closing operation of the first opening / closing means. The image forming apparatus described in 1. 5. The image forming apparatus according to claim 1, wherein the first opening / closing unit is provided on an upper surface of the image forming apparatus and can be opened upward from the image forming apparatus. 6. The image forming apparatus according to claim 1, wherein the second opening / closing means is provided on a side surface of the image forming apparatus and can be opened in a side surface direction. 7. The image forming apparatus according to claim 1, further comprising a fixing unit that fixes an image on the recording material, wherein the first opening / closing unit includes a fixing unit. 2. A fixing unit for fixing an image on a recording material, wherein the fixing unit is disposed in the main body of the image forming apparatus when the first opening / closing unit and the second opening / closing unit are open. The image forming apparatus according to claim 6. The image forming apparatus according to any one of claims 1 to 8, wherein the image forming unit is detachable from an opening formed when the second opening / closing means is opened. The image forming apparatus according to claim 1, comprising a plurality of image forming units.

Images