Patent Application
20200231394
The present invention relates to a sheet feeding apparatus suitable for an image forming apparatus such as an electro-photographic copying machine or an electro-photographic printer (for example, a laser beam printer, an LED printer and the like).
In the electro-photographic image forming apparatus, a toner image formed on a photosensitive body in an image forming portion is transferred to a sheet, and the toner image is heated and melted by a fixing device so that the toner image is fixed on the sheet. Japanese Patent Application Laid-Open No. 2017-45007 discloses the configuration that can be attached to and detached from a lower part of the main body of the image forming apparatus as a sheet feeding apparatus that feeds a sheet toward the image forming portion.
In addition, when the sheet on which the image is formed contains a lot of moisture, a toner image transfer failure may occur, or the sheet may curl so that the leading end of the sheet may be folded during sheet conveyance. To deal with this problem, Japanese Patent Application Laid-Open No. 2009-298523 discloses the configuration of a sheet feeding apparatus in which a heating unit that dehumidifies the sheet by heating can be attached above the sheet cassette in which sheets are stacked and stored.
When a heating unit is attached to and detached from the sheet feeding apparatus like the configuration of Japanese Patent Application Laid-Open No. 2009-298523 in the configuration in which the sheet feeding apparatus is attached to and detached from the lower portion of the main body of the image forming apparatus like the configuration of Japanese Patent Application Laid-Open No. 2009-298523, the following problem may occur.
Namely, when the heating unit is attached and detached in the state where the sheet feeding device is not fixed to the main body of the image forming apparatus, the relative position between the main body of the image forming apparatus and the sheet feeding apparatus may be displaced. In this case, a sheet feeding failure or the like may occur.
An object of the present invention is to provide a sheet feeding apparatus capable of suppressing the displacement of the relative position between the sheet feeding apparatus and the main body of the image forming apparatus when a heating unit is attached to or detached from the sheet feeding apparatus.
A representative configuration of the present invention is a sheet feeding apparatus configured to be attached to a lower part of an image forming apparatus with respect to a vertical direction and to feed a sheet to the image forming apparatus, the sheet feeding apparatus including a frame body; and a sheet cassette in which a sheet is stacked, the sheet cassette being accommodated in the frame body, wherein a heating unit configured to heat the sheet stacked in the sheet cassette is attachable to the frame body at a position above the sheet cassette with respect to the vertical direction, the sheet feeding apparatus comprising:
a locking member provided on an upper part of the frame body, the locking member being configured to be movable between a locking position where the frame body is locked to the image forming apparatus and a releasing position where locking of the frame body is released,
wherein in attaching the heating unit to an attaching position of the frame body, the locking member is configured to restrict a movement of the heating unit to the attaching position by interfering with the heating unit when the locking member is located at the releasing position and to allow a movement of the heating unit to the attaching position when the locking member is located at the locking position.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
<Image Forming Apparatus>
Hereinafter, the overall configuration of an image forming apparatus including a sheet feeding apparatus according to the present invention will be described with reference to the drawings together with operations during image formation. The size, material, shape, and relative arrangement of the components described below are not intended to limit the scope of the invention unless otherwise specifically noted.
The sheet feeding unit 61 includes the sheet cassette 17 in which the sheets S are stacked and stored and the feeding roller 14 that feeds the sheets S stacked and stored in the sheet cassette 17. The sheet cassette 17 is configured to be able to be inserted into and removed from the frame body 80 of the main body 1 of the image forming apparatus A. When a user stores the sheets in the sheet cassette 17, the sheet cassette 17 is pulled out by the user.
The image forming portion 62 includes the processes cartridges P (PY, PM, PC, and PK) in each of which the photosensitive drums 2 (2Y, 2M, 2C, and 2K), a charging roller (not shown), a developing device (not shown) are integrated. The image forming portion 62 further includes the primary transfer rollers 5 (5Y, 5M, 5C, and 5K), the laser scanner unit 7, the intermediate transfer belt 8, the secondary transfer roller 12, the secondary transfer counter roller 10, and the tension roller 11.
Under the main body 1 in the vertical direction of the image forming apparatus A, the sheet feeding apparatus 50 which is detachably attachable to the main body 1 is optionally provided. The sheet feeding apparatus 50 for feeding the sheets S toward the image forming apparatus 62 includes the sheet cassette 51 in which the sheets S are stacked and stored, and the sheet feeding roller 52 for feeding the sheets S stacked and stored in the sheet cassette 51. The sheet cassette 51 and the sheet feeding roller 52 are different from the ones provided in the sheet feeding portion 61. The sheet cassette 51 is configured to be able to be inserted into and removed from the frame body 300 (refer to
In the present embodiment, the image forming apparatus A refers to the entire apparatus including the main body 1 and the sheet feeding apparatus 50. Namely, the main body 1 refers to a portion other than the sheet feeding apparatus 50 in the image forming apparatus A.
As shown in
As described above, the heating unit 100 dehumidifies the sheets S by heating the sheets S stacked and stored in the image forming apparatus A. Accordingly, even when the image forming apparatus A is placed in a hot and humid environment so that the sheets S accommodated in the device contain a lot of moisture, it is possible to suppress both the degradation of the quality of an image to be formed on the sheet S, and the abnormality of the conveyance due to curling.
Next, the operation of image forming will be described. First, when a control portion (not shown) receives an image forming job signal, the sheet S stacked on the sheet cassette 17 or the sheet cassette 51 is sent to the registration roller 16 by the feeding roller 14 or the feeding roller 52. The registration roller 16 conveys the sheet S at a predetermined timing to the secondary transfer portion configured by the secondary transfer roller 12 and the secondary transfer counter roller 10.
On the other hand, in the image forming portion, the surfaces of the photosensitive drums 2 are uniformly charged by charging rollers (not shown). Thereafter, the laser scanner unit 7 irradiates the surfaces of the photosensitive drums 2 of respective colors with laser light in accordance with image data transmitted from an external device (not shown) or the like, thereby forming electrostatic latent images on the surfaces of the photosensitive drums 2.
Thereafter, the toners of respective colors are attached to the electrostatic latent images formed on the surfaces of the photosensitive drums 2 by developing devices (not shown) to form toner images on the surfaces of the photosensitive drums 2. The toner images formed on the surfaces of the photosensitive drums are primarily transferred to the intermediate transfer belt 8, respectively, by applying bias to the primary transfer rollers 5. As a result, a full-color toner image is formed on the surface of the intermediate transfer belt 8.
Thereafter, the intermediate transfer belt 8 moves in a circular manner, so that the toner image is sent to the secondary transfer portion. By applying bias to the secondary transfer roller 12 at the secondary transfer portion, the toner image on the intermediate transfer belt 8 is transferred onto the sheet S.
Next, the sheet S to which the toner image has been transferred is heated and pressurized at the fixing device 20, whereby the toner image on the sheet S is fixed to the sheet S. Thereafter, the sheet S on which the toner image has been fixed is discharged to the discharge portion 90 by the discharge roller 22.
<Sheet Feeding Apparatus>
Next, the configuration of the sheet feeding apparatus 50 will be described.
The opening portion 301 formed in the frame body 300 is located below the locking mechanism 310 in the direction of the arrow Z. The sheet cassette 51 is inserted into and removed from the opening portion 301 in the directions of the arrow Y.
As shown in
The locking mechanism 310 includes the operation portion 313, rack portions 314 and 316, the pinion gears 315 and 317 that respectively mesh with the rack portions 314 and 316, and the shaft portion 312. The shaft portion 312 (rotating shaft) pivotally supports the pinion gear 315 at one end, and pivotally supports the rear hook 311 at the other end.
When the operation portion 313 is held and moved in the direction of the arrow X (in a translational movement), the rack portion 314 moves in the direction of the arrow X. As a result, the pinion gear 315 that meshes with the rack portion 314 and the pinion gear 317 that meshes with the rack portion 316 rotate respectively.
As a result, the shaft portion 312 that pivotally supports the pinion gear 315 rotates, and the rear hook 311 that is pivotally supported by the shaft portion 312 rotates in the directions of the arrow R1. Further, the gear 318 which meshes with the pinion gear 315 rotates, and the front hook 319 which is coaxial with the gear 318 rotates in the directions of the arrow R2.
When the rear hook 311 rotates in the directions of the arrow R1 as described above, the rear hook 311 moves between the position where the rear hook 311 is engaged with the locking plate 99 provided on the frame body 80 of the main body 1 by being hooked on the locking plate 99 and the position where the engagement with the locking plate 99 is released as shown in
Similarly, when the front hook 319 rotates in the directions of the arrow R2, the front hook 319 moves between the position where the front hook 319 is engaged with the locking plate 95 provided on the frame body 80 by being hooked on the locking plate 95 as shown in
That is, when the front hook 319 and the rear hook 311 rotate, they move together between the locking position where they are engaged with the locking plates 95 and 99 to lock the frame body 300 of the sheet feeding apparatus 50 with respect to the frame body 80 of the main body 1 and the releasing position where the engagement (locking) is released and the frame body 300 is allowed to move relative to the frame body 80 of the main body 1. The lock position is a restricting position where the movement of the frame body 300 relative to the frame body 80 of the main body 1 is restricted, and the releasing position is a position where the locking of the frame body 300 of the sheet feeding apparatus 50 with respect to the frame body 80 of the main body 1 is released.
In the present embodiment, in consideration of the balance of the locking mechanism 310, the front hook 319 and the rear hook 311 are arranged diagonally. However, the present invention is not limited to this, and the number and the arrangement of hooks can be changed as appropriate.
In the present embodiment, the configuration in which the front hook 319 and the rear hook 311 are rotated by the rack and pinion mechanism has been described. However, the present invention is not limited to this. For example, the rear hook 311 may be rotated by directly rotating the shaft portion 312, or a rotational driving force may be transmitted by a gear or a timing belt to rotate a plurality of hooks.
<Heating Unit>
Next, the configuration of the heating unit 100 will be described in detail.
As shown in
The drawer connector 107 of the heater 120 is connected to a connector (not shown) of the main body 1, so that electric power is supplied to the heater 120 by the power supply on the main body 1 for generating heat. The heater 120 is held by the heater holding plate 101 and is covered with the heater cover 110 from above.
The heater holding plate 101 has the front engagement protruding portions 103a, the front engagement protruding portions 103b, the rear engagement protruding portion 102a, and the rear engagement protruding portion 102b. The front engagement protruding portions 103a, and the front engagement protruding portions 103b are fitted into the front engagement hole portions 321a, and the front engagement hole portions 321b of the frame body 300, respectively (see
By this fitting, the heating unit 100 is positioned at the attaching position with respect to the frame body 300, and the drawer connector 107 and the connector (not shown) of the main body 1 can be connected. The connection between the drawer connector 107 and the connector (not shown) of the main body 1 may be performed by manual plugging and unplugging or by the configuration in which the drawer connector 107 is connected to the connector of the main body 1 automatically in accordance with the positioning of the heating unit 100. Further, regarding this positioning configuration, hole portions may be provided on the heater holding plate 101 and protruding portions may be provided on the frame body 300. The connector (not shown) of the main body 1 is an example of a first connector, and the drawer connector 107 is an example of a second connector. Instead of supplying the heater 120 with power by means of the power source on the main body 1, the heater 120 may be supplied with power from a commercial power source via an outlet dedicated to the heating unit 100 separately from the main body 1. In this case, by connecting the drawer connector 107 with a connector (not shown) for commercial power, power may be supplied. In this case, the connector (not shown) for commercial power is an example of the first connector, and the drawer connector 107 is an example of the second connector.
On the upper surface of the heater cover 110, the groove formed member 111 having the engaging groove 111a (engaging portion) is provided. The shaft portion 312 of the locking mechanism 310 is fitted into the engaging groove 111a. The heater cover 110 is provided with a protruding member 109 that protrudes upward above the upper surface of the heater cover 110. The protruding member 109 is disposed at a position adjacent to the groove formed member 111 when viewed from the direction of attaching the heating unit 100.
<Way of Attaching Heating Unit>
Next, a way of attaching the heating unit 100 to the frame body 300 will be described.
As shown in
As shown in
On the other hand, as shown in
Further, as shown in
The front hook 319 is located outside the opening 301 of the frame body 300 in both the locking position and the releasing position. Therefore, when the heating unit 100 is attached or detached, the front hook 319 does not interfere with the heating unit 100.
As described above, when the heating unit 100 is attached and detached, the movement of the heating unit 100 is guided by the shaft portion 312 of the locking mechanism 310. Accordingly, the locking mechanism 310 performs both a function of fixing the frame body 300 of the sheet feeding apparatus 50 to the frame body 80 of the main body 1 of the image forming apparatus A and a function of guiding the movement of the heating unit 100. Therefore, the number of parts can be reduced and the heating unit 100 can be easily attached and detached as compared with the configuration in which a guide member is provided separately.
Further, when the rear hook 311 is located at the releasing position, the attaching of the heating unit 100 is restricted by the rear hook 311. Accordingly, it is possible to restrict the attaching of the heating unit 100 in the unstable state where the frame body 300 is not fixed to the frame body 80 of the main body 1 of the image forming apparatus A. Therefore, it is possible to suppress the relative position of the sheet feeding apparatus 50 to the main body 1 from being displaced as the heating unit 100 is attached.
Further, after the heating unit 100 is attached, the rear hook 311 can be rotated between the locking position and the releasing position. Accordingly, the sheet feeding apparatus 50 can be detached from the main body 1 of the image forming apparatus A by moving the rear hook 311 to the releasing position in the state where the heating unit 100 is attached to the frame body 300.
Although the locking position is obtained at the position shown in
Although the releasing position is obtained at the position shown in
As described above, as long as the configuration is adopted in which the heating unit 100 can be attached only in the state in which the relative position of the frame body 300 of the sheet feeding device 50 with respect to the frame 80 of the main body 1 is not displaced, the range of the locking positions and the releasing positions of the rear hook 311 may be changed as appropriate.
It is also possible to provide a plurality of sheet feeding apparatuses 50 and connect them using the locking mechanism 310.
As shown in
As a result, when the heating unit 100 is attached to the lower sheet feeding apparatus 50, it is possible to suppress the relative displacement between the upper feeding apparatus 50 and the lower feeding apparatus 50. In addition, by nipping the front hook 319 with the plate-like member 96 and the plate-like member 97, the front hook 319 can be prevented from being tilted in the front-rear direction.
In the present embodiment, the configuration has been described in which the attaching of the heating unit 100 is restricted by the rear hook 311 in the state where the locking of the frame body 300 to the frame body 80 of the main body 1 is released. However, the present invention is not limited to this. For example, the attaching of the heating unit 100 may be restricted by the front hook 319 with the front hook 319 rotating in a direction opposite to that of the present embodiment. With this configuration, similar effects can be obtained. Further, instead of restricting the attaching of the heating unit 100 directly by the front hook 319 or the rear hook 311, the movement of the heating unit 100 toward the attaching position may be restricted by another member that moves, interlocking with the rotation of the front hook 319 or the rear hook 311.
In the present embodiment, the configuration in which the frame body 300 of the sheet feeding apparatus 50 is locked to the frame body 80 of the main body 1 of the image forming apparatus A by the locking mechanism 310 has been described. However, the present invention is not limited to this. The frame body 300 of the sheet feeding device 50 may be locked to an attachment member or the like which is attached to the bottom surface of the image forming apparatus A.
In the present embodiment, the configuration of the locking mechanism 310 has been described in which the locking and the releasing of the locking mechanism 310 are performed by rotating the front hook 319 and the rear hook 311. However, the present invention is not limited to this. Namely, for example, by operating the operation unit 313, a member of the locking mechanism 310 may protrude toward the bottom surface of the image forming apparatus A to fit into a recessed portion provided on the bottom surface of the image forming apparatus A, thereby locking the sheet feeding apparatus 50 to the main body 1.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2019-006143, filed Jan. 17, 2019, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2019-006143 | Jan 2019 | JP | national |
