This application claims priority from Japanese Patent Application No. 2011-144586, filed on Jun. 29, 2011, the entire subject matter of which is incorporated herein by reference.
The disclosure relates to an image forming apparatus configured such that an expansion member is provided in a lower part of a main body of the image forming apparatus to attach a large-capacity sheet feed tray to the main body.
A known image forming apparatus includes a main body having a space for a standard-capacity sheet feed tray. In the known image forming apparatus, one or more expansion members are attachable to a lower part of the main body. When the space is expanded by the one or more expansion members, a larger-capacity sheet feed tray can be attached to the main body.
However, in the known image forming apparatus, a body frame constituting the main body is placed on the expansion members without being fixed. Therefore, when any force is applied to the body frame, the body frame may sway with respect to the expansion members. This may result in deterioration of quality of an image to be formed on a sheet.
An embodiment of the disclosure provides for an image forming apparatus in which swaying of a body frame with respect to an expansion member may be reduced.
According to aspects of the disclosure, an image forming apparatus may include a first tray, a pair of body frames, a pair of expansion members, a plurality of first connectors, an under bar, and a second connector. The first tray may be configured to accommodate one or more recording sheets to be supplied to an image forming unit. The pair of body frames may be disposed to sandwich therebetween an upper part of the first tray. The pair of expansion members may be disposed under the pair of body frames to sandwich therebetween a lower part of the first tray. The plurality of first connectors may be configured to connect the pair of body frames and the pair of expansion members with each other. The under bar may be bridged between the pair of expansion members. The second connector may be configured to connect one of the expansion members and the under bar with each other. Each of the expansion members have a longitudinal axis which extends in an attaching-detaching direction of the first tray. Further, the expansion member connected with the second connector may be configured such that a phantom line, which extends through the expansion member in a direction parallel to the attaching-detaching direction of the first tray, is in line with the second connector. Further, the phantom line may divides the expansion member connected with the second connector into a first side and a second side, such that the first side is a side that is closer to the image forming unit than the second side, and the second side is the opposite side that is farther from the image forming unit than the first side. At least one of the two or more of the plurality of first connectors which are disposed in the expansion member connected with the second connector, may be disposed on the first side, and at least one of the two or more of the plurality of first connectors which are disposed in the expansion member connected with the second connector, may be disposed on the second side.
According to one embodiment of the disclosure, the pair of body frames and the pair of expansion members may be connected with each other by the plurality of first connectors. Therefore, swaying of the pair of body frames with respect to the pair of expansion members may be reduced. The first connectors arranged on the first and second sides with respect the phantom line may surely reduce swaying of the one of the pair of expansion members against the under bar with respect to the phantom line.
According to aspects of the disclosure, the swaying of the pair of body frames with respect to the pair of expansion members may be reduced.
Illustrative aspects will be described in detail with reference to the following figures in which like elements are labeled with like numbers and in which:
An embodiment of the disclosure will be described in detail with reference to the accompanying drawings. First, an overall configuration of a common laser printer 1 will be described. Then, a laser printer 100, e.g., an image forming apparatus, according to aspects of the disclosure will be described in detail.
In the description below, orientations of the laser printers 1, 100 are defined when each of the laser printers 1, 100 is disposed in an orientation in which it is intended to be used by a user. That is, the right in
As shown in
The main body 2 comprises a pair of right and left body frames 21, a top panel 22, and a front cover 23. The top panel 22 is disposed between the body frames 21 to connect upper portions of the body frames 21 with each other. The front cover 23 is configured to be pivotable with respect to the body frames 21. The top panel 22 comprises a sheet discharge tray 22A which is configured to hold one or more sheets P to be discharged to the outside of the main body 2.
The feeder unit 3 is disposed in a lower part of the main body 2 and comprises a sheet feed tray 31 and a pressing plate 32. The sheet feed tray 31 is configured to be attachable to and detachable from the main body 2 from the front of the laser printer 1. The pressing plate 32 is disposed in the sheet feed tray 31. The feeder unit 3 further comprises a feed roller 33, a separation roller 34, and a separation pad 35. The feed roller 33 is disposed above leading edges of sheets P stacked in the sheet feed tray 31. The separation roller 34 and the separation pad 35 are disposed downstream of the feed roller 33 in a conveying direction of the sheet P. The feed roller 33 and the separation roller 34 are supported by a single support member (to which a reference numeral is not assigned) and configured to be rotatable independently.
The support member is configured to pivotable about the separation roller 34 such that the feed roller 33 is movable with respect to the separating roller 34. The pressing plate 32 is supported by the sheet feed tray 31 such that the pressing plate 32 is pivotable about a rear end 32A of the pressing plate 32 and a front end 32B of the pressing plate 32 moves toward and away from the feed roller 33. The feeder unit 3 further comprises a paper dust removing roller 36A, a conveyor roller 36B, and a pair of registration rollers 37. The paper dust removing roller 36A is disposed downstream of the separation roller 34 in the conveying direction. The conveyor roller 36B is disposed facing the paper dust removing roller 36A. The pair of registration rollers 37 is disposed downstream of the paper dust removing roller 36A in the conveying direction.
The sheet feed tray 31 is configured to be attachable to and detachable from the pair of the body frames 21 in a front-rear direction. The feed roller 33, the separation roller 34, and the conveyor roller 36B are held by the main body 2. The separation pad 35 and the paper dust removing roller 36A are held by the sheet feed tray 31. Therefore, when the sheet feed tray 31 is drawn toward the front, the separation roller 34 and the paper dust removing roller 36A are disengaged from the separation pad 35 and the conveyor roller 36B, respectively.
In the feeder unit 3 configured as described above, one or more sheet P are pressed against the feed roller 33 by the pivoting of the pressing plate 32 and are fed by the feed roller 33. The fed one or more sheets P are then separated one by one by the separation roller 33 and the separation pad 35 and are conveyed to the image forming unit 4 successively through the conveyor roller 36B and the pair of registration rollers 37.
The image forming unit 4 comprises a scanner unit 5 and a process cartridge 6, and a fixing unit 7.
The scanner unit 5 is disposed in an upper part of the main body 2 and comprises a laser-emitting portion (not shown), a polygon mirror, lens and reflectors (to which reference numerals are not assigned). The scanner unit 5 is configured to irradiate a surface of a photosensitive drum 61 with a laser beam by high-speed scanning
The process cartridge 6 is configured to be attachable to and detachable from the main body 2 through an opening that appears by the opening of the front cover 23. The process cartridge 6 comprises a photosensitive drum 61, a transfer roller 62, a charger, a developing roller, a layer-thickness regulating blade, and a toner chamber (to which reference numerals are not assigned).
In the process cartridge 6, the charger uniformly charges the surface of the rotating photosensitive drum 61. Then, the scanner unit 5 exposes the surface of the photosensitive drum 61 with a laser beam by the high-speed scanning Thus, a potential of the exposed portion to which the laser beam is irradiated becomes lowered and an electrostatic latent image is formed on the surface of the photosensitive drum 61 based on image data.
Then, the developing roller supplies the electrostatic latent image formed on the photosensitive drum 61 with toner from the toner chamber to form a toner image on the surface of the photosensitive drum 61. After that, while the sheet P passes between the photosensitive drum 61 and the transfer roller 62, the toner image formed on the photosensitive drum 61 is transferred onto the sheet P.
The fixing unit 7 comprises a heating unit 71 and a pressing roller 72. The heating unit 71 comprises, for example, a halogen heater, a fixing film, and a nip plate (to which reference numerals are not assigned). The pressing roller 72 is configured to nip the fixing film between the heating unit 71 and the nip plate. In the fixing unit 7 configured as described above, the toner transferred onto the sheet P is fixed on the sheet P by heat while the sheet P passes between the heating unit 71 and the pressing roller 72.
Then, the sheet P, on which the toner has been thermally fixed by the fixing unit 7, is conveyed to a sheet discharge roller R. The sheet discharge roller R is disposed downstream of the fixing unit 7 in the conveying direction. The sheet P is further conveyed by the sheet discharge roller R and is discharged onto the sheet discharge tray 22A.
Hereinafter, the laser printer 100 according to aspects of the disclosure will be described. As shown in
That is, the laser printer 100 comprises the larger-capacity sheet feed tray 110, the pair of body frames 21, and the pair of expansion members 200. The body frames 21 are disposed on opposite sides of the larger-capacity sheet feed tray 110 and configured to sandwich an upper part of the larger-capacity sheet feed tray 110 therebetween. The body frames 21 are made of resin material. The expansion members 200 are disposed on opposite sides of the larger-capacity sheet feed tray 110 and configured to sandwich a lower part of the larger-capacity sheet feed tray 110 therebetween. The laser printer 100 comprises other units or portions, e.g., image forming unit 4 and top panel 22, of the laser printer 1, other than the sheet feed tray 31 for the laser printer 1. In the laser printer 100, as shown in
The larger-capacity sheet feed tray 110 is deeper than the sheet feed tray 31 (see
As shown in
With this configuration, the body frames 21 can be commonly used for the sheet feed tray 31 and for the larger-capacity sheet feed tray 110. That is, when the sheet feed tray 31 (e.g., maximum capacity: 250 sheets) is demanded to be used, only the pair of body frames 21 is used. When the larger-capacity sheet feed unit 110 (e.g., maximum capacity: 500 sheets) is demanded to be used, the pair of expansion members 200 and the pair of body frames 21 are used in combination.
As shown in
The body-side gear 21C is disposed slightly above the bottom surface of the body frame 21 (see the first boundary line LA). Therefore, when the laser printer 100 is placed on, for example, a floor, without the pair of expansion members 200 attached as shown in
As shown in
As shown in
As shown in
With this configuration, the first screws S1 arranged on the right and left of the phantom line L1 may surely reduce the swaying of the expansion members 200 if the expansion members 200 are shook against the under bars 201 with respect to the phantom line L1.
Each of the two second screws S2 are provided to each of the expansion members 200. The two second screws S2 are positioned on the phantom line L1 in each of the expansion members 200. More specifically, the front second screw S2 is located such that a part of the front second screw S2 overlaps the phantom line L1 in each of the expansion members 200. With this configuration, the two under bars 210 are used as common parts. The common use of the under bars 210 may facilitate manufacture of the under bars 210.
The two adjacent first screws S1 arranged in the front-rear direction, e.g., two adjacent first screws S1 (front and intermediate first screws S1) disposed at the forward part of the left expansion member 200, are disposed in front of and behind the second screw S2 (on one side and the other side of the second screw S2 in the attaching-detaching direction). With this arrangement, the second screw S2 is positioned between the first screws S1 disposed in the front-rear direction and this configuration may prevent the expansion member 200 from separating from the body frame 21.
All of the first screws S1 are arranged adjacent to the phantom line L1 in each of the expansion members 200. In particular, the two first screws S1, e.g., the intermediate and rear first screws S1 disposed on the left expansion member 200 overlap the phantom line L1 in the left expansion member 200, and the rear first screw S1 disposed on the right expansion member 200 overlaps the phantom line L1 in the right expansion member 200.
More first screws S1 are disposed on the second side than the first side with respect to the phantom line L1 in each of the expansion members 200. Therefore, when force is applied to the body frames 21 from the second side in the right-left direction with respect to the phantom line L1, this arrangement may reduce a tendency that the body frames 21 lean inward with respect to the expansion members 200 as compared with a configuration in which the same number of the first screws S1 are provided and more first screws S1 are disposed on the first side than the second side with respect to the phantom line L1 in each of the expansion members 200.
The front and intermediate first screws S1 are disposed in front of and behind a swing gear 222, e.g., joint gear, (see
As shown in
More specifically, the transmission mechanism 220 comprises a central gear 221, the swing gear 222, and a swing arm 223. The swing gear 222 is engaged with the central gear 221 and is configured to rotate while swinging about the central gear 221. The swing arm 223 connects a rotational shaft 221A of the central gear 221 and a rotational shaft 222A of the swing gear 222 with each other. The rotational shaft 222A extends through the rotational center of the swing gear 222. In this embodiment, the rotational shaft 222A passes through an opening formed in the center of the swing gear 222 and both ends of the rotational shaft 222A are fixed to the swing arm 223 by clamping.
The swing gear 222 (more specifically, the rotational shaft 222A of the swing gear 222) is urged by a coil spring 224 such that the swing gear 222 protrudes upward from the upper surface of the expansion member 200, when the expansion member 200 is separated from the body frame 21.
With this configuration, when the expansion member 200 is attached to the corresponding body frame 21, the swing gear 222 is swung by which the movement of the rotational shaft 222A is stopped by interference of the rotational shaft 222A of the swing gear 222, which is disposed higher than the upper surface of the expansion member 200, with the body frame 21. Therefore, a pitch between the swing gear 222 and the body-side gear 21C may be adjusted.
The one of the expansion members 200 comprises a current-carrying member 230 configured to transmit power from the body frame 21 to the add-on sheet feeder 300. More specifically, an upper end of the current-carrying member 230 is connected with a body-side current-carrying member 430, which is connected with a control unit 400 disposed in the body frame 21, and a lower end thereof is connected with a feeder-side current-carrying member 330, which is connected an electromagnetic clutch 325 (described later) disposed in the add-on sheet feeder 300. The control device 400 is connected with an external power source via a wiring (not shown).
With this configuration, the electromagnetic clutch 325 of the add-on sheet feeder 300 can be controlled by the control unit 400 disposed in the body frame 2. Therefore, the common use of the control unit 400 may reduce costs. Each of the current-carrying members 230, 330, 430 may comprise, for example, two terminal and a harness, or may be made by a printed wiring board.
As shown in
The expander-side protrusions 240 have a substantially cylindrical shape. One of the expander-side protrusions 240 is disposed at the forward part of the top of each of the expansion members 200 and the other is disposed at the rearward part of the top of each of the expansion members 200 such that the expander-side protrusions 240 are positioned coaxially with the corresponding body-side recesses 21D. As shown in
The body-side gear 21C and the transmission mechanism 220 are disposed between the expander-side protrusions 240 in the front-rear direction. With this arrangement, if the expansion member 200 is inclined in a direction that is separated from the one of the expander-side protrusions 240 with respect to the other of the expander-side protrusions 240 when the expansion member 200 is attached to the corresponding body frame 21, the transmission mechanism 220 does not contact the body frame 21. Therefore, damage to the transmission mechanism 220 may be reduced.
The body-side gear 21C and the transmission mechanism 220 are disposed near the front expander-side protrusion 240. Accordingly, the transmission mechanism 220 may be joined to the body-side gear 21C precisely.
As shown in
The feeder-side protrusions 340 have a substantially cylindrical shape and the same diameter as the expander-side protrusions 240. For example, four feeder-side protrusions 340 are positioned coaxially with the corresponding expander-side recesses 241. Two each of the feeder-side protrusions 342 are disposed at the forward part and rearward part of the add-on sheet feeder 300 (only one of the feeder-side protrusions 340 is shown in
The feeder-side protrusions 340 protrude further upward than the swing gear 322 of a feeder-side transmission mechanism 320 (described later). The transmission mechanism 220 and the swing gear 322 are disposed between two feeder-side protrusions 340, more specifically, near the forward feeder-side protrusion 340. Accordingly, damage to the swing gear 322 may be prevented or reduced and the swing gear 322 may be engaged with the transmission mechanism 220 and the body-side gear 21C precisely.
As shown in
More specifically, a projecting portion 251 projects upward from the upper portion of each of the hand wells 250. The projecting portion 251 has an appropriate size such that the projecting portion 251 enters the body-side hand well 21E and the top of the projecting portion 251 is positioned adjacent to an upper surface of the body-side hand well 21E.
With this configuration, the user may carry the laser printer 100 with having the same balance as when the user carries the laser printer 1 comprising the smaller-capacity sheet feed tray 31.
As shown in
The add-on sheet feeder 300 is configured to feed a sheet P to the image forming unit 4 from the second sheet feed tray 310 by conveying the sheet P upward using the rollers 33, 34, 36A, 36B of the add-on sheet feeder 300 via the paper dust removing roller 36A and the conveyor roller 36B of the larger-capacity sheet feed tray 110. More specifically, the larger-capacity sheet feed tray 110 comprises a conveyance guide 111, which is disposed near a front wall of the larger-capacity sheet feed tray 110 to guide the sheet P being conveyed. Sheets P stacked in the second sheet feed tray 310 of the add-on sheet feeder 300 are conveyed one by one to the paper dust removing roller 36A and the conveyor roller 36B of the larger-capacity sheet feed tray 110 through the conveyance guide 111.
As shown in
The feeder-side transmission mechanism 320 is connected with a drive mechanism 350, which is configured to move the pressing plate 32 up and down. Therefore, the pressing plate 32 of the add-on sheet feeder 300 may be driven by the motor 21A of the one of the body frames 21.
More specifically, the feeder-side transmission mechanism 320 comprises a central gear 321 and a swing gear 322, which have substantially the same structure as the central gear 221 and the swing gear 222 of the transmission mechanism 220. The feeder-side transmission mechanism 320 further comprises gears 323 (only one of which is shown in
The electromagnetic clutch 325 is controlled by the control unit 400 of the one of the body frame 21. By this control, the drive force of the motor 21A is supplied to the feed roller 33 or stopped supplying to the feed roller 33.
While aspects of the disclosure have been described in detail with reference to the specific embodiment thereof, it would be apparent to those skilled in the art that various changes, arrangements and modifications may be applied therein without departing from the spirit and scope of the disclosure.
In the above-described embodiment, the image forming unit 4 comprising the scanner unit 5, the process cartridge 6, and the fixing unit 7 is adopted. However, aspects of the disclosure are not limited to the specific embodiment. For example, an image forming unit using an LED head, using a photosensitive belt, or using a heat roller, may be adopted.
In the above-described embodiment, sheets P, e.g., cardboards, postcards, thin paper, are adopted as an example of the recording sheet. However, aspects of the disclosure are not limited to the specific embodiment. For example, overhead transparency films may be adopted as the recording sheet.
In the above-described embodiment, the add-on sheet feeder 300 is adopted as the add-on mechanism. However, aspects of the disclosure are not limited to the specific embodiment. For example, the add-on mechanism may be another pair of expansion members. That is, one or more pairs of expansion members 200 may be disposed under the above-described pair of expansion members 200 and the add-on sheet feeder 300 may be disposed under the lowermost pair of expansion members 200.
In the above-described embodiment, the swing gear 222 is swung by the swing arm 223 that connects the rotational shaft 221A of the central gear 221 and the rotational shaft 222A of the swing gear 222 with each other. However, aspects of the disclosure are not limited to the specific embodiment. For example, the swing gear 222 may be swung along an arc-shaped groove.
In the above-described embodiment, the body-side recesses 21D and the expander-side protrusions 240 are adopted as a positioning portion. However, aspects of the disclosure are not limited to the specific embodiment. For example, recesses may be provided in the expansion member 200, and protrusions may be provided on the body frame 2.
In the above-described embodiment, the one of the two body-side recesses 21D is disposed at the forward part of each of the body frames 21 and the other is disposed at the rearward part of each of the body frames 21. The one of the two expander-side protrusions 240 is disposed at the forward part of each of the expansion members 200 and the other is disposed at the rearward part of each of the expansion members 200. However, aspects of the disclosure are not limited to the specific embodiment. For example, only one each of the body-side recess 21D and the expander-side protrusion 240 may be provided, or three or more of the body-side recesses 21D and three or more of the expander-side protrusions 240 may be provided.
In the above-described embodiment, the two under bars 210 are provided and disposed at the forward part and rearward part of the expansion members 200. However, aspects of the disclosure are not limited to the specific embodiment. For example, a single under bar 210 may be disposed at the forward part of each of the expansion members 200 or at the central part of each of the expansion members 200.
In the above-described embodiment, the two adjacent first screws S1 in the front-rear direction are disposed in front of and behind the one second screw S2. However, aspects of the disclosure are not limited to the specific embodiment. For example, the two adjacent first screws S1 may be disposed in front of the second screw S2 only or behind the second screw S2 only.
In the above-described embodiment, the three first screws S1 are arranged in each of the expansion members 200 such that more first screws S1 are disposed on the second side than the first side with respect to the phantom line L1. However, aspects of the disclosure are not limited to the specific embodiment. The three first screws S1 may be arranged in each of the expansion members 200 such that more first screws S1 are disposed on the first side than the second side with respect to the phantom line L1.
In the above-described embodiment, the swing gear 222 and the rotational shaft 222A are provided as separate parts. However, aspects of the disclosure are not limited to the specific embodiment. The rotational shaft 222A may be integral with the swing gear 222. In the above-described embodiment, the rotational shaft 222A is made in contact with the body frame 21. However, aspects of the disclosure are not limited to the specific embodiment. The configuration may be changed such that a body frame restricts the movement of a shaft portion that passes through the center of rotation a the swing gear. For example, the movement of the shaft portion may be restricted by contact between a bearing, which rotatably supports the shaft portion of the swing gear, and the body frame.
In the above-described embodiment, aspects of the disclosure are applied to the laser printer 100. However, aspects of the disclosure are not limited to the specific embodiment. Aspects of the disclosure may be applied to other image forming apparatus, e.g., copying machines or multifunction peripheral.
In the above-described embodiment, the screws are adopted as the first and second connectors. However, aspects of the disclosure are not limited to the specific embodiment. The first and second connectors may be, for example, bolts and nuts.
Number | Date | Country | Kind |
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2011-144586 | Jun 2011 | JP | national |