JP4519000B2 - Sheet feeding device - Google Patents

Description

  The present invention relates to a sheet feeding device such as a feeding cassette for feeding a stored sheet.

  In general, a sheet feeding device of an image forming apparatus such as a printer is provided with a bottom plate, and on the other hand, a feeding device side is equipped with a motor-driven bottom plate push-up mechanism. Automatically pushes up the bottom plate and the sheets stacked on it. Even when the number of sheets is small, the uppermost sheet stacked on the feeding cassette is always pressed against the pick roller of the feeding device so as to be fed.

As an example of such a sheet feeding apparatus, Patent Document 1 discloses that a sector gear and an idler gear (drive receiving means) for rotating a bottom plate are arranged on the outer surface side of one side wall of a feeding cassette, and the feeding cassette is a printer. By attaching to the main body, the idler gear (drive receiving means) meshes with the drive transmission gear (drive transmission means) of the motor (drive means) provided in the printer main body. Proposed.
JP 2003-246468 A (see FIG. 1)

  In the feeding cassette of Patent Document 1, the drive receiving means arranged on the outer surface side of one side wall protrudes outside the side wall. For this reason, for example, if an attempt is made to form protrusions for guiding insertion of the feeding cassette into the printer main body on both side walls of the feeding cassette, the protrusions are shortened by the amount of the protrusion of the drive receiving means. There is a problem that it is necessary (see FIG. 2) and design restrictions increase. In particular, in a model in which the drive receiving means is arranged on the front side of the feeding cassette, the protrusion on one side wall is interrupted at the front part, so that the left and right weight balance is lost when the feeding cassette is mounted, causing rattling. There was a problem.

  Further, since the user frequently touches the sheet feeding cassette for sheet replenishment, it is dangerous if gears or the like are exposed.

  In addition, some image forming apparatuses such as printers have a structure in which only a specified specific feeding cassette can be properly mounted according to the destination of the apparatus. In other words, when an undesignated feeding cassette is to be mounted on the apparatus, the feeding cassette or the apparatus body has a feeding cassette incompatibility that prevents the feeding cassette from being mounted. It has become.

  Various means have been proposed as means for realizing such incompatibility. For example, a chip on which data relating to incompatibility such as destination information is recorded is mounted on a feeding cassette, When it is installed in the main body of the machine, the data on the incompatibility is accessed from the main body side so that only the feeding cassette that matches the main body is recognized, or in a simpler case, between the feeding cassette and the main body of the equipment. An engagement (fitting) mechanism is provided for each, and the engagement state is changed according to the design for each destination, and the incompatibility of the feeding cassette is determined by whether or not the appropriate engagement state is maintained when the feeding cassette is mounted. Some will be realized.

  However, embedding chips in the feed cassette as in the former may increase the part cost and increase the product price. Even in the latter method, it is necessary to change the specifications of the feed cassette itself. Production cost will be high.

  The present invention has been made in view of the above-described problems, and prevents rattling at the time of mounting the feed cassette without increasing design constraints, and realizes incompatibilities of the feed cassette at low cost. It is an object of the present invention to provide a sheet feeding apparatus that can perform the above operation.

  In order to achieve the above object, the present invention provides a pair of opposing side walls, a bottom plate that is rotatably disposed between both side walls, and a sheet on which sheets are stacked, and is disposed on the outer surface side of one side wall so A drive receiving means to be moved, a cover which is detachably attached to one side wall and covers the drive receiving means, and is arranged on the outer surface of each side wall so as to extend in the mounting direction of the sheet feeding apparatus to the image forming apparatus main body. When the sheet feeding apparatus is mounted on the image forming apparatus main body, the image forming apparatus main body is guided in contact with the guide rail provided on the image forming apparatus main body. In the sheet feeding device in which the drive receiving means is connected to the drive transmission means provided in the cover, the outer surface of the cover is connected to the protrusions provided on the one side wall to thereby connect the cover and the one side wall. Overall Characterized in that a ridge that constitutes a One ridges.

  Further, the present invention is characterized in that a shape for imparting incompatibility of the sheet feeding device is provided to the protrusion of the cover.

  According to the present invention, the drive receiving means is covered with the cover, so that the gears are not exposed and the safety to the user can be maintained. In addition, the drive receiving means is provided by providing the protrusion on the cover. It is possible to make up for the shortage of the length of the protrusion on one side wall that has been lost by providing the protrusion, and to extend the protrusion to the front side of the sheet feeding apparatus. As a result, it is possible to prevent rattling caused by uneven lengths of the ridges when the sheet feeding apparatus is mounted while reducing the design constraints for forming the protrusions on the sheet feeding apparatus.

  And since the shape that gives incompatibility of the sheet feeding device is given to the protrusion of the cover, it is possible to change the sheet feeding device by simply replacing the cover while keeping the specifications other than the cover of the sheet feeding device in common. Incompatibility can be provided at low cost.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an image forming apparatus including a feeding cassette (sheet feeding apparatus) according to the present embodiment. FIG. 2 is a schematic perspective view of the feeding cassette of FIG. In this embodiment, a laser beam printer (hereinafter simply referred to as “printer”) 1 is illustrated as an example of an image forming apparatus. Needless to say, the image forming apparatus can be applied to apparatuses other than a printer, such as a copying machine or a facsimile apparatus.

  First, an outline of the printer 1 will be described. Rollers 4a, 4b, and 4c that convey a sheet S fed from a feeding cassette 2 that can be attached to and detached from the printer 1, and information light D that is based on image information is a photosensitive member that is an electrophotographic photosensitive member of the image forming means 6. The scanner unit 5 for irradiating the drum 6a, the image forming means 6 for forming an image on the photosensitive drum 6a, the transferring means 7 for transferring the image formed on the photosensitive drum 6a to the sheet S, and the transferred image on the sheet S A fixing unit 8 for fixing and a control unit (not shown) are provided.

  The image forming unit 6 includes the above-described photosensitive drum 6 a and at least one process unit, and is unitized as a process cartridge that can be attached to and detached from the printer 1. Examples of the process means include a charging means for charging the photosensitive drum 6a, a developing means for developing a latent image formed on the photosensitive drum 6a, and a cleaning means for cleaning toner remaining on the surface of the photosensitive drum 6a. is there.

  In the printer 1 having such a configuration, the information light D based on the image information is irradiated from the scanner unit 5 to the photosensitive drum 6a, a latent image is formed on the photosensitive drum 6a, and the latent image is developed to develop the photosensitive image. A toner image is formed on the body drum 6a. The printer 1 feeds the sheets S one by one from the feeding cassette 2 by the pick roller 1a in synchronization with the formation of the toner image, and separates and feeds the sheets S one by one by the feed roller 1b and the retard roller 1c. Then, the toner image formed on the photosensitive drum 6 a constituting the image forming unit 6 is transferred onto the sheet S by the transfer unit 7. The transferred sheet S is conveyed to the fixing unit 8 where the transferred toner image is fixed by the fixing unit 8, and is further discharged outside the apparatus by the discharge roller 4c.

  Here, the configuration of the sheet feeding apparatus according to the present embodiment will be specifically described with reference to FIGS. 2 and 3.

  As shown in FIG. 2, the feeding cassette 2 is rotatably supported between the bottom wall 20, a pair of opposing side walls 21 and 22 that define the width of the cassette, and both side walls 21 and 22. And a bottom plate 2g on which sheets S (not shown) are stacked.

  An idler gear 2d is rotatably supported on the front outer surface of one side wall 21. The sector gear 2e meshes with the idler gear 2d and is installed at one end of a bottom plate push-up arm 2f that is rotatably supported by the feeding cassette 2. The sector gear 2e and the bottom plate push-up arm 2f Are the same. The idler gear 2d and the sector gear 2e constitute drive receiving means for moving the bottom plate 2g up and down. A cover 25 that covers the drive receiving means is detachably attached to one side wall 21 with screws 26.

  On the other hand, in the printer 1 main body, a stepping motor (not shown) and a transmission gear (not shown) rotatably supported so as to rotate by this drive are arranged, and the above-mentioned feeding cassette When 2 is attached to the printer 1, the idler gear 2d (drive receiving means) and the transmission gear (drive transmission means) are engaged with each other.

  Further, on the outer surfaces of the side walls 21 and 22, ridges 23 and 24 are integrally formed so as to extend in the mounting direction of the feeding cassette 2 to the printer. On the other hand, guide rails 9 and 10 attached to the main body of the printer 1 are arranged on both sides of the feeding cassette mounting space opened on the front surface of the main body of the printer 1.

  The printer 1 stops driving the stepping motor (not shown) when the uppermost surface of the sheet S (not shown) is pressed against the pick roller 1a.

  By the way, since the drive receiving means protrudes on the front outer surface side of the one side wall 21, the front portion of the ridge 23 is interrupted by the amount of this bulge, and compared with the ridge 24 extending almost the entire length of the other side wall 22. And it will be shorter.

  Therefore, when the cover 25 is mounted by providing a protrusion 27 extending in the mounting direction of the feeding cassette 2 as shown in FIG. 2 on the outer surface of the cover 25, the lower surfaces of the protrusion 27 and the protrusion 23 face each other. By connecting so that it may become one, the cover 25 and the one side wall 21 whole comprise one protrusion (refer FIG. 3). By doing so, the shortage of the length of the ridge 23 of one side wall 21 is compensated by the ridge 27 of the cover 25 and extended to almost the entire length of the side wall 21, and the ridges of the one and other side walls 21 and 22 are extended. The length will be aligned.

  At this time, as shown in FIG. 2, if a recess 28 reflecting the cross-sectional shape of the ridge 23 is provided in the side surface portion of the cover 25 to form a fitting structure, the ridge 23 and the ridge 27 are more appropriately communicated. You may be able to do it reliably.

  Further, a trapezoidal convex portion 27 a is integrally formed at a predetermined position on the lower surface of the protrusion 27 of the cover 25. On the other hand, a concave portion 9a having the same shape as the convex portion 27a is formed on the upper surface of the guide rail 9 at a position corresponding to the convex portion 27a.

  When the feeding cassette 2 is attached to the printer 1, as shown in FIGS. 4 and 5A, the projections 23 and 24 are brought into contact with the guide rails 9 and 10 provided in the printer 1, respectively. Then, the feeding cassette 2 is inserted in the direction of the arrow. After the insertion, as shown in FIG. 5 (b), the protrusions 23 and 24 are placed on the guide rails 9 and 10, respectively, and the convex portions 27a and the concave portions 9a are fitted to each other. Is appropriately attached to the printer 1. Accordingly, it is possible to prevent the problem that the weight balance between the left and right is broken and the rattling occurs when the feeding cassette 2 is mounted.

  When the feeding cassette 2 is attached to the printer 1 in this way, a sensor (not shown) detects that the feeding cassette 2 is attached to the printer 1 and drives a stepping motor (not shown). The drive rotates a transmission gear (not shown), the idler gear 2d meshing with the transmission gear rotates in the arrow direction (clockwise direction) in FIG. 2, and the bottom plate push-up arm 2f is rotated via the sector gear 2e. As a result, the bottom plate 2g is rotated.

  Further, according to this configuration, the incompatibility of the feeding cassette 2 according to the destination of the printer 1 can be easily realized. An example of this will be described below with reference to FIGS.

  For example, when there are two destinations of the same type of printer, the cover 25 corresponds to one destination and the other destination as shown in FIGS. 6 (a) and 6 (b). Two types of covers 25 are prepared in which the positions of the protrusions in the length direction of the ridges 27 are shifted by a distance d1 (see reference numeral 27a in FIG. 6A and reference numeral 27a ′ in FIG. 6B). . Making the covers 25 having different specifications can be easily realized by using the same mold having a plurality of convex portions and filling the unnecessary convex portions with pins or the like to perform resin molding. And about the feeding cassette 2, the specifications of the feeding cassette 2 itself other than the cover 25 are left unchanged.

  Then, only by attaching each of such covers 25, as shown in FIGS. 7A and 7B, the lengths of the ridges 23 and 27 correspond to one destination and the other destination. Two types of feeding cassettes 2 having different convex portions can be easily produced.

  On the other hand, as shown in FIGS. 8 (a) and 8 (b), the guide rail 9 is shifted in position corresponding to the two types of feeding cassettes 2 as shown in FIGS. It is provided (see reference numeral 9a in FIG. 8A and reference numeral 9a ′ in FIG. 8B). Such separate manufacture of the guide rails 9 having different specifications can be easily realized by using the same mold having a plurality of recesses, filling unnecessary recesses with pins or the like, and molding with resin.

  Then, as shown in FIGS. 9 (a) and 9 (b), by simply attaching each guide rail 9 as described above, a recess in the entire length of the guide rail 9 corresponds to one destination and the other destination. Two types of printers 1 having different positions can be easily manufactured.

  In such a configuration, as shown in FIGS. 10A and 10B, when the feeding cassette 2 and the main body of the printer 1 are matched, that is, the feeding cassette 2 in FIG. In the case of a combination with the printer 1 main body of FIG. 10A (FIG. 10A) and in the case of the combination of the feeding cassette 2 of FIG. 7B and the main body of the printer 1 of FIG. )), Each convex portion and concave portion are fitted, and the feeding cassette 2 is appropriately mounted to the printer 1.

  On the other hand, as shown in FIGS. 11A and 11B, when the feeding cassette 2 and the printer 1 main body are not compatible, that is, the feeding cassette 2 in FIG. 7A and FIG. ) In combination with the printer 1 main body (FIG. 11A), and in the case of combination with the feeding cassette 2 in FIG. 7B and the printer 1 main body in FIG. 9A (FIG. 11B). ), The convex portions and the concave portions are not fitted, and the side wall 21 side of the feeding cassette 2 is lifted forward, so that the feeding cassette 2 cannot be properly mounted on the printer 1.

  As described above, the incompatibility of the feeding cassette 2 according to the destination of the printer 1 can be easily realized by only slight changes in the specifications of the cover 25 and the printer 1 main body. In the above example, the case where there are two destinations of the printer 1 has been described. However, when there are three or more destinations, different combinations of the fitting positions of the convex portions and the concave portions are added accordingly. By doing so, complete incompatibility can be realized. In addition to shifting the fitting position between the convex part and the concave part as described above, incompatibility can also be achieved by changing the engagement depth of the convex part and the concave part or changing the number of convex parts and concave parts. realizable.

  The present invention can be used in image forming apparatuses such as printers, copiers, and facsimiles.

FIG. 1 is a schematic configuration diagram of a printer according to an embodiment of the present invention. These are the schematic perspective views which show the state which removed the cover which covers the drive reception means of the feeding cassette which concerns on embodiment of this invention. These are the schematic perspective views which show the state which removed the cover which covers the drive receiving means of the feeding cassette which concerns on the said embodiment. FIG. 5 is a schematic perspective view for explaining an operation of mounting the sheet feeding cassette according to the embodiment on a printer main body. These are the schematic sectional drawings of the principal part explaining the operation | movement which mounts the sheet | seat feeding cassette which concerns on the said embodiment to a printer main body. These are front views of two types of covers with different specifications covering the drive receiving means of the feeding cassette. These are the schematic side views of the feeding cassette which attached each of two types of covers from which the said specifications differ. These are schematic side views of two types of guide rails with different specifications provided in the printer body. These are schematic sectional views of the main part of the printer body to which two types of guide rails having different specifications are attached. These are the schematic sectional drawings of the principal part at the time of feeding cassette mounting in case a feeding cassette and a printer main body fit. These are the schematic sectional drawings of the principal part at the time of feeding cassette mounting in case a feeding cassette and a printer main body do not fit.

Explanation of symbols

1 Printer 1a Pick roller 1b Feed roller 1c Retard roller 2 Feed cassette (sheet feeding device)
2d idler gear (drive receiving means)
2e Sector gear 2g Bottom plate 2f Bottom plate push-up arm 5 Scanner unit 6 Image forming means 6a Photosensitive drum 7 Transfer means 8 Fixing means 9, 10 Guide rail 9a Recess 20 Bottom wall 21 One side wall 22 Other side wall 23 Projection on one side wall 24 Projection on the other side wall 25 Cover 27 Projection 27a Projection S Sheet

Claims (2)

A pair of side walls facing each other, a bottom plate rotatably disposed between both side walls, a drive receiving means disposed on an outer surface side of one side wall to move the bottom plate up and down, and one side wall A sheet feeding device comprising: a cover that is detachably attached to cover the drive receiving means; and a protrusion that is provided on an outer surface of each side wall so as to extend in a mounting direction of the sheet feeding device to the image forming apparatus main body. When the image forming apparatus main body is mounted, the protrusion is brought into contact with a guide rail provided in the image forming apparatus main body to guide, and the drive receiving means is provided to a drive transmission unit provided in the image forming apparatus main body in the mounted state. In the sheet feeding apparatus in which the means are connected,
A sheet feeding device, wherein a protrusion that forms one protrusion on the entire surface of the cover and one side wall is provided on the outer surface of the cover by communicating with the protrusion provided on the one side wall.   2. The sheet feeding apparatus according to claim 1, wherein a shape for imparting incompatibility of the sheet feeding apparatus is provided to the protrusion of the cover.

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