Patent Application
20080187380
This application is based on and claims priority under 35 U.S.C. 119 from Japanese Patent Application No. 2006-323460 filed Nov. 30, 2006.
1. Technical Field
The present invention relates to an image forming apparatus such as a printer, a copying machine, a facsimile, etc.
2. Related Art
In the image forming apparatus of this kind, the following structure is known. In this structure, an inversion conveyance assembly body in which a recording medium once discharged by normal rotation of a discharging member until an intermediate portion is again taken-in and conveyed by reverse rotation of the discharging member, is freely mounted. In a first driving path for normally rotating the discharging member, transmission of driving force of the above driving source to the above discharging member is interrupted by mounting the inversion conveyance assembly body. The above inversion conveyance assembly body has a second driving path for transmitting the driving force of the driving source to the discharging member so as to be freely rotated normally and reversely.
According to an aspect of the present invention, an image forming apparatus including: an image forming apparatus main body; an image forming section that is arranged within the image forming apparatus main body, and that forms an image in a recording medium; a discharging member that discharges the recording medium on which the image is formed by the image forming section; a driving source that normally and reversely rotates the discharging member; and a both-face printing assembly body that returns the recording medium pulled-back by reversely rotating the discharging member to the image forming section, the driving source and the both-face printing assembly body being separately freely attached and detached with respect to the image forming apparatus main body.
Exemplary embodiment of the present invention will be described in detail based on the following figures, wherein:
An embodiment mode of the present invention will next be explained. The following explanation is merely one example in executing the present invention, and the present invention is not limited to matters explained below, but can be suitably changed in accordance with necessity.
In
The paper feed assembly body 18 has a paper feed cassette 20 for storing a recording medium and arranged in the image forming apparatus main body 12 so as to be freely pulled out. Further, this paper feed assembly body 18 has paper feed members 22a, 22b and a handling member 24. The recording medium stacked on the paper feed cassette 20 is separated and fed to a resist member 26 by cooperation of these paper feed members 22a, 22b and the handling member 24.
For example, the image forming section 14 is of an electrophotographic type, and is constructed by an image holding body 28 formed by a photosensitive body, a charging device 30, an optical writing device 32, a developing device 34, a transfer device 36, a cleaning device 38 and a fixing device 40. For example, the charging device 30 is constructed by a charging roll for uniformly charging this image holding body 28. The optical writing device 32 writes a latent image to the image holding body 28 charged by this charging device 30 by light. The developing device 34 visualizes the latent image of the image holding body 28 formed by this optical writing device 32. The transfer device 36 transfers a developing agent image using the developing device 34 to the recording medium. The cleaning device 38 cleans the developing agent left in the image holding body 28. The fixing device 40 fixes the developing agent image on the recording medium transferred by the transfer device 36 to the recording medium, and is constructed by e.g., a pressurizing roll and a heating roll. For example, the optical writing device 32 is constructed by a laser exposing device of a scanning type, and crosses the interior of a process cartridge 46 and forms the latent image in the image holding body 28. The cleaning device 38 has a cleaning blade 42 coming in contact with the image holding body 28 and also has a developing agent collecting portion 44 for storing the developing agent scraped off by this cleaning blade 42. The optical writing device 32 can use a LED, a face light emitting laser, etc. as another embodiment mode.
In the process cartridge 46, the image holding body 28, the charging device 30, the developing device 34 and the cleaning device 38 are integrated, and these members can be integrally exchanged.
A main conveying path 50 reaching the discharging portion 16 through a portion between the image holding body 28 and the transfer device 36, the fixing device 40 and a discharging member 48 is formed on a rear flow side of the resist member 26. When one face printing is designated in the image forming apparatus 10, the recording medium sent out of the paper feed cassette 20 of the paper feed assembly body 18 by the paper feed members 22a, 22b is temporarily stopped by a resist member 24 and is conveyed to the main conveying path 50 by taking timing. A developing agent image is formed on one face by passing a portion between the image holding body 28 and the transfer device 36. The developing agent image is then fixed by the fixing device 40, and is discharged to the discharging portion 16 by normal rotation of the discharging member 48.
A first driving source 52 constructed by e.g., a motor is arranged within the image forming apparatus main body 12 and is connected to the conveying members 22a, 22b, the image holding body 28, the charging device 30, the developing device 34, the transfer device 36 and the fixing device 40 through e.g., a gear series, and operates these members. Further, at a basic construction time shown in
A driving source assembly body 54 and a both-face printing assembly body 56 are separately attached and detached with respect to the image forming apparatus main body 12, and are mounted to the image forming apparatus main body 12 in a state adding a both-face printing function shown in
The driving source assembly body 54 has a second driving source 58 constructed by e.g., a motor, and this second driving source 58 can be rotated normally and reversely, and normally and reversely operates the discharging member 48.
In the both-face printing assembly body 56, one portion of an inversion path 60 is formed and conveying members 62a, 62b for both-face printing are arranged. The inversion path 60 is formed so as to be branched from the main conveying path 50 before the discharging member 48 and be returned until the resist member 24. Further, the both-face printing assembly body 56 has a third driving source 64 constructed by e.g., a motor. This third driving source 64 is connected to the conveying members 62a, 62b for both faces and operates these conveying members 62a, 62b for both faces in an inverting direction.
Further, a hand assembly 66 is arranged on a front face (a left-hand side face of
When both-face printing is performed, the discharging member 48 is reversely rotated (rotation of a direction for pulling-in the recording medium) at a time point at which this side of a rear end of the recording medium reaches the discharging member 48. The recording medium is then pulled back and is guided to the inversion path 60. The recording medium is conveyed along the inversion path 60 by the conveying members 62a, 62b for both faces and the conveying member 72 for both faces and a hand until the recording medium hits against the resist member 24. The recording medium is temporarily stopped by the resist member 24, and is conveyed to the main conveying path 50 by taking timing. A developing agent image is then formed on the remaining one face by passing a portion between the image holding body 28 and the transfer device 36. The developing agent image is fixed by the fixing device 40, and is discharged to the discharging portion 16 by normal rotation of the discharging member 48.
Here, a circumferential speed of a reverse rotation direction of the discharging member 48 using the second driving source 58 is set to be faster than the circumferential speed of a normal rotation direction of the discharging member using the first driving source 52 or the second driving source 58 at an absolute value. A conveying speed V1 of the recording medium in a pulling-back case of the recording medium is faster than a conveying speed V2 of the recording medium in a discharging case of the recording medium. Therefore, the recording medium can be rapidly pulled-in.
Further, the conveying speed V1 of the reverse rotating direction of the recording medium conveyed by operating the second driving source 58 through the discharging member 48 is set to be faster than a conveying speed V3 of the recording medium conveyed by operating the above third driving source 64 through the conveying members 62a, 62b for both faces. When the recording medium is delivered to the conveying members 62a, 62b for both faces from the discharging member 48, tensile force is set not to be applied to the recording medium.
A recording medium conveying path 74 is arranged in the above paper feed cassette 20. When plural paper feed cassettes are overlapped and arranged at many stages, the recording medium supplied by another paper feed cassette arranged on the lower side is conveyed by this recording medium conveying path 74. Further, a driving control section 76 for controlling operations of the first driving source 52, the second driving source 58, the third driving source 64, etc. is arranged within the image forming apparatus main body 12.
A driving mechanism of the discharging member 48 will next be explained.
In
The above first driving source 52 is arranged on e.g., the first side face 82 side, and the driving source assembly body 54 is arranged on the second side face 84 side. The “side face side” shows a state shifted on one side from the center between the first side face 82 and the second side face 84.
As shown in
The second driven gear 88 is fixed to the discharging member 48 and is engaged with a second driving gear 92 arranged in the driving source assembly body 54. The driving source assembly body 54 is constructed by engaging the second driving gear 92 with an output gear 94 of the second driving source 58.
In the case of the basic construction shown in
A third embodiment mode in the present invention is shown in
A fourth embodiment mode in the present invention is shown in
The second driven gear 88 is fixed to one end of the discharging member 48 in parallel with the first driven gear 86. At a basic constructing time of the image forming apparatus, the first driven gear 86 is engaged with the first driving gear 90 connected to the first driving source 52. When the driving source assembly body 54 is mounted to the image forming apparatus main body 12 from this state, as shown in
In this fifth embodiment mode, as shown in
The foregoing description of the embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-323460 | Nov 2006 | JP | national |
