Patent Grant
9132976
This application is based upon, and claims the benefit of priority from, corresponding Japanese Patent Application No. 2013-189760 filed in the Japan Patent Office on Sep. 12, 2013, the entire contents of which are incorporated herein by reference.
Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
A known electrophotographic system image forming apparatus with a photoreceptor drum includes a separating device for separating a paper sheet from a drum circumferential surface. The separating device includes a plurality of separation claws having distal end portions in contact with the circumference surface of the photoreceptor drum. Each separation claw is held by a holder together with a guiding roller for guiding the paper sheet as an assembly. The respective assemblies are arranged at a distance from each other in the axial direction of the photoreceptor drum. In a drum frame that supports the photoreceptor drum, a securing portion for securing each assembly is formed. This securing portion is constituted of a plurality of projecting portions and engaging hole portions formed in the projecting portions. Each assembly is secured to the drum frame such that an engaging claw formed in the holder is engaged with the engaging hole portion formed in the above-described projecting portion.
A paper separating device for separating a paper sheet according to the disclosure include a frame member, an image carrier, a securing plate, and two types of assemblies. The image carrier is rotatably supported by the frame member and rotatable in abutting contact with a paper sheet. The securing plate is to be removably mounted on the frame member. The two types of assemblies include a first assembly and a second assembly. The first assembly includes: a separation claw configured to separate the paper sheet from the image carrier; a guiding member configured to guide the paper sheet; and a holder with an engaging portion. The holder holds the separation claw and the guiding member. The second assembly that engages the guiding member alone to the holder with the engaging portion without holding the separation claw. The frame member and the securing plate each include an assembly securing portion with an engaged portion to be engaged with the engaging portion of the holder. One of the two types of assemblies is secured to a second assembly securing portion disposed at the securing plate while another is secured to a first assembly securing portion disposed at the frame member.
These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description with reference where appropriate to the accompanying drawings. Further, it should be understood that the description provided in this summary section and elsewhere in this document is intended to illustrate the claimed subject matter by way of example and not by way of limitation.
Example apparatuses are described herein. Other example embodiments or features may further be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. In the following detailed description, reference is made to the accompanying drawings, which form a part thereof.
The example embodiments described herein are not meant to be limiting. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the drawings, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.
Hereafter, a detailed description will be given of embodiments of the disclosure with reference to the drawings. The disclosure will not be limited to the embodiments described below.
As illustrated in
The above-described paper sheet feeder 10 is arranged in the lower portion within the main-body housing portion 60. The paper sheet feeder 10 includes a sheet feed cassette 10a and a pickup roller 10b. The sheet feed cassette 10a houses the sheet-shaped paper sheet P. The pickup roller 10b takes out the paper sheet P within the sheet feed cassette 10a and sends the paper sheet P to the outside of the cassette. The paper sheet P sent to the outside of cassette from the sheet feed cassette 10a is supplied to the image forming unit 20 via the conveyance roller pair 11. In the image forming unit 20, a toner image based on predetermined image data is transferred to the paper sheet P supplied by the paper sheet feeder 10. The paper sheet P is supplied to the fixing unit 40. In the fixing unit 40, the paper sheet P supplied by the image forming unit 20 is pressed between a fixing roller 40a and a pressure roller 40b to fix the toner image to the paper sheet P. Then, the paper sheet P to which the toner image is fixed by the fixing unit 40 is sent out to the downstream side by both rollers 40a and 40b. The paper sheet P sent out by the fixing unit 40 is discharged to the above-described discharging unit 50 via the plurality of conveyance roller pairs 12 and 13.
The above-described image forming unit 20 includes a photoreceptor drum 21. In the peripheral area of the photoreceptor drum 21, with reference to the ten o'clock direction, a charger 23, an exposure apparatus 25, a developing unit 27, a transfer unit 29, the paper separating device 31, a cleaning apparatus 33, and a static eliminator 35 are arranged anticlockwise in the drawing in this order.
The above-described charger 23 uniformly charges the circumference surface of the photoreceptor drum 21 via a charging roller 23a. The above-described exposure apparatus 25 irradiates a laser beam to the circumference surface of the photoreceptor drum 21 to form an electrostatic latent image corresponding to the predetermined image data.
The above-described developing unit 27 supplies toner to the electrostatic latent image on the circumference surface of the photoreceptor drum 21 for visualization as a toner image. The transfer unit 29 applies a transfer bias to a transfer roller 29a to transfer the toner image formed on the circumference surface of the photoreceptor drum 21 to the paper sheet P.
As illustrated in
The above-described drum frame 71 includes a pair of sidewall portions 71a and a cleaning case portion 71b. The pair of sidewall portions 71a rotatably supports both the end portions of the photoreceptor drum 21 in the axial direction. The cleaning case portion 71b is disposed across both the sidewall portions 71a. The cleaning case portion 71b constitutes the outer wall portion of the cleaning apparatus 33.
As illustrated in
In the cleaning case portion 71b, the end surface on the upstream side in the drum rotation direction is designed to be a vertical surface in a rectangular shape extending in the axial direction of the photoreceptor drum 21. This end surface on the upstream side constitutes a securing-plate mounting surface 71f for mounting a securing plate 72 on the cleaning case portion 71b (the drum frame 71). The lower end portion of the securing plate 72 is folded in an L shape toward the inner side of the cleaning case portion 71b so as to form a seal mounting portion 72t. On the seal mounting portion 72t, a film-shaped sealing member 73 is mounted. The sealing member 73 is constituted by, for example, a polyethylene terephthalate (PET) film. The sealing member 73 is formed in a rectangular shape extending in the axial direction of the photoreceptor drum 21. One long-side portion of the sealing member 73 is secured to the seal mounting portion 72t while the other long-side portion is in abutting contact with the circumference surface of the photoreceptor drum 21. Thus, the sealing member 73 prevents leakage of the toner within the cleaning case portion 71b from the gap between the cleaning case portion 71b and the photoreceptor drum 21 to the upstream side of the drum rotation direction.
The above-described paper separating device 31 has a function that separates the paper sheet P from the circumference surface of the photoreceptor drum 21 and guides the paper sheet P to the downstream side in the paper sheet conveyance direction such that the paper sheet P does not flow into the cleaning case portion 71b. Specifically, the paper separating device 31 includes a first assembly 81 and a second assembly 82. The first assembly 81 has both a paper separating function and a paper guiding function. The second assembly 82 has the paper guiding function only. Both the assemblies 81 and 82 include common (same) holders 100. In the following description, unless it is explicitly stated otherwise, both the assemblies 81 and 82 are described to be in a state (a state in
As illustrated in
The above-described pair of vertical plate portions 105 is secured to one side in the thickness direction of the holder main body 101. Both the vertical plate portions 105 are arranged at a distance from each other in the drum axial direction. In the upper end portion of each vertical plate portion 105, a first bearing hole portion 105f passing through in the drum axial direction is formed. This first bearing hole portion 105f is rotatably fitted with a support shaft 91a of the guiding roller 91. In the intermediate portion in the up-down direction of each of the vertical plate portions 105, a second bearing hole portion 105g is formed. This second bearing hole portion 105g is rotatably fitted with a support shaft 92a of the separation claw 92.
The circumference surface of the guiding roller 91 has a saw-teeth shape where depressed portions and protruding portions are alternately arranged in the circumferential direction. This reduces the contacted area between the guiding roller 91 and the paper sheet P as much as possible, thus reducing attachment of toner to the guiding roller 91 before the toner is thermally fixed to the paper sheet P.
The separation claw 92 is biased around the support shaft 92a by a biasing member (not illustrated) such that the distal end portion of the separation claw 92 is brought into pressure contact with the circumference surface of the photoreceptor drum 21.
As illustrated in
As illustrated in
As illustrated in
The above-described frame-side second projecting portion 71h is arranged at a distance from the frame-side first projecting portions 71g at the upper side. The frame-side second projecting portion 71h is arranged across both the frame-side first projecting portions 71g viewed from the upper side. The frame-side second projecting portion 71h is formed in a rectangular block shape extending in the drum axial direction. In the frame-side second projecting portion 71h, a frame-side second engaging hole 71k passing through in the thickness direction (the up-down direction) is formed. To the first-assembly securing portion 71c constituted as described above, the above-described first assembly 81 is assembled and secured as described later.
As illustrated in
As illustrated in
As illustrated in
The above-described securing-plate-side second projecting portion 72h is arranged at a distance from the above-described securing-plate-side first projecting portions 72g at the upper side. The securing-plate-side second projecting portion 72h is arranged across both the securing-plate-side first projecting portions 72g viewed from the upper side. The securing-plate-side second projecting portion 72h has a rectangular plate shape extending in the drum axial direction. The securing-plate-side second projecting portion 72h is formed by folding the upper end portion of the securing plate 72. In the securing-plate-side second projecting portion 72h, a securing-plate-side second engaging hole 72k passing through in the thickness direction (the up-down direction) is formed. To the second-assembly securing portion 72a constituted as described above, the above-described second assembly 82 is assembled and secured as described later.
The following describes an assembly procedure of the paper separating device 31 to the drum frame 71 with reference to
In the first step, two of the second assemblies 82 are prepared to be assembled to the second-assembly securing portions 72a of the securing plate 72 (in the step on the upmost side of
In the next step, the securing plate 72 to which the second assemblies 82 are assembled is mounted on the securing-plate mounting surface 71f of the drum frame 71 (in the step in the middle of
In the last step, the first assembly 81 is assembled to the above-described exposed first-assembly securing portion 71c (in step on the downmost side of
As described above, in the above-described embodiment, the paper separating device 31 includes the first assembly 81 that has both the paper separating function and the paper guiding function, and additionally includes the second assembly 82 that has the paper guiding function only. This can improve the conveyability (guiding performance) of the paper sheet P after being separated from the circumference surface of the photoreceptor drum 21 by the separation claw 92. Moreover, the above-described first and second assemblies 81 and 82 employ the same holders 100. This can commonalize components, thus reducing the product cost.
In the above-described embodiment, the second-assembly securing portion 72a for securing the second assembly 82 is formed not in the drum frame 71 but in the securing plate 72. This can separate the assembly step (in the step on the upmost side of
In the above-described embodiment, the second-assembly securing portion 72a is formed in the securing plate 72 for securing the sealing member 73. This can suppress the increase in the number of components using the existing securing plate 72. This can reduce the product cost.
That is, in this embodiment, on the securing-plate mounting surface 71f of the drum frame 71, a pair of regulating portions 71p is formed. The pair of regulating portions 71p regulates the displacement of the first engaging claws 103, which is formed in the holder 100 of the second assembly 82, toward the engagement releasing side. The respective regulating portions 71p are formed to project to the inside of the pair of through-holes 72m formed in the securing plate 72. The regulating portions 71p are each arranged adjacent to the arm portion 102 of the holder 100 at the upper side within the through-hole 72m. Accordingly, this regulating portion 71p regulates the upward displacement of the arm portion 102. Thus, the regulating portion 71p regulates the displacement of the engaging claw 103 to the upper side (that is, the engagement releasing side). This can prevent the second assembly 82 once assembled to the second-assembly securing portion 72a from being carelessly removed. Thus, this can reliably prevent the first assembly 81 from being erroneously assembled to the second-assembly securing portion 72a.
In the above-described embodiments, the examples where the paper separating device 31 is applied to the photoreceptor drum 21 have been described. This, however, should not be construed in a limiting sense. For example, the paper separating device 31 may be applied to the fixing roller (fixing drum) 40a for heat fixing of toner to a paper sheet. In the above-described embodiments, the second assembly 82 is secured to the securing plate 72 and the first assembly 81 is secured to the drum frame 71. This, however, should not be construed in a limiting sense. The first assembly 81 may be secured to the securing plate 72 and the second assembly 82 may be secured to the drum frame 71.
While in the above-described embodiments the copier 1 has been described as one example of the image forming apparatus, the image forming apparatus according to the disclosure is not limited to this. For example, another image forming apparatus such as a printer, a scanner device, or a multi-functional peripheral is possible.
As described above, the disclosure is effective for an electrophotographic system image forming apparatus with a photoreceptor drum, in particular, effective for an image forming apparatus with separating unit for separating a paper sheet from a photoreceptor drum.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
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|---|---|---|---|
| 2013-189760 | Sep 2013 | JP | national |
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| Number | Date | Country | |
|---|---|---|---|
| 20150108708 A1 | Apr 2015 | US |
