JP2007047404A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that positioning is insufficient when an openable/closable guide plate is closed. <P>SOLUTION: Pins 84a, 84b, 84c and 84d sliding in a thrust direction relative to a lower guide 81 are released from the fitting members 87a and 87b of upper guides 86a and 86b by a releasing member 85, whereby the lower guide 81 is opened downward. By positioning the upper guides 86a and 86b independently by the pin 84 of the lower guide 81, one-side closed state is prevented and the alignment of a gap between the guides and mutual rollers is secured. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image on a sheet material.

  In an image forming apparatus, sheet materials of various sizes and materials are generally fed by a sheet feeding device, sent to an image forming unit, and after an image is formed, an unfixed image is fixed and discharged.

  In recent years, in an image forming apparatus, in order to reduce the installation space, it is desired to reduce the space of the apparatus. On the other hand, the type of sheet material to be conveyed is increasing year by year and requires a large number of paper feed stages, and a feeding device capable of feeding a large amount of paper is provided to eliminate the troublesomeness of sheet replenishment. Is also desired.

  In response to these demands, a paper deck that can accommodate and feed a large capacity sheet is disposed on the side of the apparatus body, and the sheet is supplied from the paper deck. However, in this configuration, a space of the apparatus main body is taken up by a paper deck or the like, and this wrinkle eats up a sheet conveyance space, that is, a sheet conveyance guide space. In addition, the space for jamming is reduced by reducing the space for the guide.

In order to solve this problem, as shown in FIG. 9, there is one in which the sheet conveying guide 96 on the lower side of the image forming unit can be pulled out (see, for example, Patent Document 1).
JP 05-097262 A

  As described above, the sheet conveyance guide is pulled out. In the jam processing, after the jam processing, one-side tightening of the hook portion that determines the positions of the sheet conveyance upper guide and the sheet conveyance lower guide becomes a problem. When the hook was tightened, the pressure balance of the transport roller was lost, causing skewing and jamming, which decreased transportability.

  In addition, if the size of the device is increased in order to increase the productivity of the device, the conveyance guide also becomes larger, and the guide plate opened by the jam processing is distorted due to its weak rigidity, making it difficult to close the hook, or between the hook back and the guide. The gap became smaller, resulting in poor conveyance.

  In order to smoothly introduce the hook into the hooked part, it was necessary to take a long end of the hook, which was an obstacle during the jam processing and required a space for the guide unit. Further, as shown in FIG. 8, once the hook does not overstroke than the positioning pin, or the two hooks do not get over the positioning pin, it will cause a single closing.

  In the present invention, the sheet conveyance guide that can be pulled out inside the image forming apparatus has a lower guide that opens downward with the hinge on the back side as a rotation center, and is movable in a thrust direction that connects the upper guide and the lower guide. The upper guide and the lower guide can be positioned by fitting a pin and the other guide side.

  By using the present invention, the space of the transport guide unit is reduced, the transport guide is prevented from being closed, and the position of the driven roller and the guide plate can be determined with respect to the transport roller, thereby ensuring transportability. An image forming apparatus can be supplied.

  Hereinafter, the present invention will be described more specifically with reference to examples. Although these examples are examples of the best mode of the present invention, the present invention is not limited to these examples.

  An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic cross-sectional view of an image forming apparatus to which the present invention is applied. Reference numeral 1 denotes a printer main body, and engine parts Y, M, C, and BK for forming primary images of a total of four colors of yellow, magenta, cyan, and black are disposed on the upper portion of the printer main body 1. Print data transmitted from an external device such as a personal computer is received by a controller that controls the printer body 1 and is output as write image data to the laser scanners 93, 96, 97, and 98 for each color.

  The laser scanner emits a laser beam onto the photosensitive drum 91 and draws an optical image according to the written image data. Reference numeral 94 denotes a folding mirror that folds the laser beam toward the photosensitive drum 91. The images on the transfer belt are matched by adjusting the writing timing of each color laser scanner.

  The primary image forming unit of each color includes a photosensitive drum 91, a charger (not shown) for uniformly charging the surface of the photosensitive drum 91, and the laser scanner 93 on the surface of the photosensitive drum 91 charged by the charger. A developing device 92 for developing an electrostatic latent image created by drawing an optical image into a toner image to be transferred to the intermediate transfer belt 40, and a toner image developed on the surface of the photosensitive drum 91 as an intermediate. A primary transfer roller 45 for transferring to the transfer belt 91 and a cleaner 95 for removing the toner remaining on the photosensitive drum 91 after transferring the toner image.

  The toner image primarily transferred to the intermediate transfer belt 40 is retransferred onto the sheet by the secondary transfer roller 44. The toner remaining without being transferred by the secondary transfer roller 44 is collected by the cleaner 46. Reference numeral 41 denotes a transfer belt driving roller, 42 denotes a transfer belt tension roller, which applies tension to the transfer belt 40 and keeps the belt tensioned, and 43 is a primary transfer counter roller.

  The sheet feeding unit is positioned at the uppermost stream of sheet conveyance, and in the printer of this embodiment, two stages are arranged in the lower part of the apparatus (10, 13). The sheet lifter plate 11 pushes the stacked sheets S up to the rollers of the sheet feeding units 12 and 14. The sheet feeding units 12 and 14 employ a configuration in which the uppermost sheet is picked up by a roller and sent downstream, but this can also employ air feeding in which the sheet is sucked and sent by air. The sheet S fed from the sheet feeding units 12 and 14 is conveyed downstream through the vertical conveyance path 20. At the most downstream position of the vertical conveyance path 20, there is a registration roller device 30, where final skew correction of the sheet and timing adjustment of image writing and sheet conveyance in the image forming unit are performed.

  A fixing device 50 for fixing the toner image on the sheet S as a permanent image is provided on the downstream side of the image forming unit.

  A flapper (not shown) capable of switching the conveyance path after passing through the fixing device 50 is provided, and a double-sided conveyance path can be selected in accordance with a request signal from the controller. A sheet reversing unit 70 that also serves as an entrance to a duplex conveyance path 80 for duplex printing, and a discharge roller 60 for discharging the sheet S on which an image has been fixed from the printer main body 1 are provided. A paper discharge tray 61 for receiving the sheet S discharged by the discharge roller is configured.

  An embodiment of the present invention will be described with reference to FIG.

The sheet feeders 10 and 13 are placed side by side below the image forming means. A duplex unit frame 32 that can be pulled out from the apparatus main body is provided on the sheet feeding apparatuses 10 and 13. The double-sided unit frame 32 can be pulled out to the front side of the apparatus main body by a slide rail 33,
The double-sided conveyance path 81, the registration apparatus 30, and the transfer unit 44 upstream from the merging unit path 21 of the sheet feeding device 13 are held and pulled out. The double-sided conveyance path 82 downstream from the merge path 21 remains in the apparatus main body.

  A support member 22 that receives a double-sided unit frame 32 (dashed line) is placed between the sheet feeding devices 10 and 13 that are arranged side by side, and beams 23 and 24 that hold the sheet feeding units 12 and 14 are provided on the support member 22. As a result, the left paper feeding unit 15 can be held stably, and the rigidity of the image forming apparatus main body can be maintained by being connected without breaking the beam.

  In addition, since the double-sided unit frame 32 on which the conveying unit 51, the registration apparatus 30, and the transfer unit 44 for transferring an image to a sheet are mounted can be received by the support member 22 at a substantially central portion of the frame, Deformation and distortion of the frame can be reduced. A roller 33 for receiving the support member 22 is provided at the center of the double-sided unit frame, which allows the roller unit to be pulled out smoothly. The double-sided conveyance path 82 is capable of jamming a sheet by raising the upper guide of the double-sided conveyance path 82 upward.

  The drawer of the duplex unit frame 32 will be described with reference to FIGS.

  The duplex unit frame 32 can be pulled out by releasing the lock of the secondary transfer roller 44 by rotating the handle 34 in the direction of the arrow. The secondary transfer roller 44 is moved / pressed / released by moving the secondary transfer roller holder 47 by a cam 35 provided on a shaft extending from the handle 34. The two-roller holder is provided with a spring for pressing the two-roller roller.

  A lock lever member 36a is provided on the shaft of the handle 34, and the double-sided unit frame 32 cannot be pulled out from the apparatus main body by engaging with the lock member 36b in the apparatus. The lock is released by turning the handle 34 in the direction of the arrow.

  At this time, the guide 21 that joins both sides from the left sheet feeding unit 15 rotates the handle 34 in the direction of the arrow so that the guide 21 is lowered and opened to enable the jam processing. It is prevented that it stops across. By rotating the guide release lever 37a provided on the shaft extending from the handle 34, the guide release gear 37b provided on the apparatus main body is rotated, and the gear portion 21c provided on the lower junction path guide 21b is moved. The merge path 21 can be opened.

  FIG. 5 is a view showing a state in which the duplex unit frame 32 is pulled out.

  Jam processing is performed by hearing the double-sided unit frame 32 and opening the double-sided conveyance path 81 of the double-sided unit frame 32 downward as indicated by an arrow. The configuration of the duplex conveyance path 81 will be described with reference to FIG. By pushing down the handle 83, the push member 88 interlocked with the handle 83 pushes the release member 85 biased by the spring. By the release member 85, the pins 84a, 84b, 84c, 84d sliding in the thrust direction with respect to the lower guide 81 are released from the fitting members 87a, 87b of the upper guides 86a, 86b, and the lower guide 81 is opened downward. The pin 84 is also biased by a spring. The fitting member 87a is a fitting hole that determines the vertical and horizontal positions of the pin 84, and the fitting member 87b is an oblong fitting hole that determines the vertical direction of the pin 84. The upper guide 86a and the upper guide 86b are the same unit and are connected to the lower guide 81 by a hinge on the same axis so as to be rotatable on the back side of the apparatus. The upper guide 86 includes two driven rollers, a paper path sensor, and fitting members 86a and 86b attached to the guide.

  Since the upper guide 86a and the upper guide 86b are independently positioned at the pin 84 of the lower guide 81, a one-closed state can be prevented, and the gap between the guides and the alignment between the rollers can be secured.

1 is a cross-sectional view of an image forming apparatus illustrating an embodiment of the present invention. 1 is a cross-sectional view of an image forming apparatus illustrating an embodiment of the present invention. 1 is a cross-sectional view of an image forming apparatus illustrating an embodiment of the present invention. The perspective view for demonstrating the drawer of the double-sided unit frame of this invention. 1 is a cross-sectional view of an image forming apparatus illustrating an embodiment of the present invention. The perspective view which shows the state which opened the duplex unit of this invention. Sectional drawing which shows the characteristic of this invention. The figure explaining an example of the past. The figure explaining the conventional drawer structure.

Explanation of symbols

1 Image forming apparatus 81 Lower guide 84 Pin 86 Upper guide 87 Fitting member

Claims (6)

The sheet conveyance guide is positioned in the horizontal direction inside the image forming apparatus, has a lower guide that can be opened downward with the hinge on the back side as the center of rotation, and is positioned horizontally on the image forming apparatus main body facing this. Has an upper guide.
Provide at least two or more pins that can move in the thrust direction on the side that is horizontally opposed to the hinge connecting the upper guide and the lower guide, and a fitting hole that can be fitted at least in the vertical direction with the pin on the other guide side, An image forming apparatus, wherein the upper guide and the lower guide can be positioned.   2. The lower guide which can be opened has pull-out means which can be pulled out integrally with the upper guide from the apparatus main body, and the lower guide can be released at a position pulled out from the main body. The image forming apparatus described.   The image forming apparatus according to claim 1, further comprising a release unit that releases the pin to be fitted.   3. The image forming apparatus according to claim 1, further comprising: a release unit that includes a plurality of conveyance guide units arranged in parallel and simultaneously releases the fitting pins that determine the position of the lower guide. 4.   The image forming apparatus according to claim 4, wherein at least two of the plurality of parallel conveyance guide units are the same.   The upper guide is divided, and at least one pin movable in the thrust direction with respect to each upper guide can be positioned by positioning means that can be fitted in at least the vertical direction of the upper guide. The image forming apparatus according to 1 or 2.

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