JP2006072205A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the miniaturization of an image forming apparatus and to provide the higher-quality image forming apparatus which realizes a good-quality image and whose working sound is low. <P>SOLUTION: The image forming apparatus for forming the image on a sheet has a drive unit 1 driving a plurality of load parts. The drive unit 1 is divided to a resister driving part 24 driving a sheet conveying part (1st load part) and an image formation driving part 25 driving an image forming part (2nd load part), and the resister driving part 24 is housed in the image formation driving part 25 so that driving can be transmitted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile machine having a function of forming an image on a sheet.

  2. Description of the Related Art Conventionally, as a driving device for an image forming apparatus such as a copying machine, there is known a configuration in which a gear is provided on a rotor shaft of an electric motor that is a driving source and connected to the gear. In some of these drive devices, a gear train is integrally assembled with an electric motor to form a unit, and the whole is covered with a sheet metal cover.

  By the way, a metal shaft is often used as a rotor shaft of an electric motor. In some cases, a pinion gear is attached to the rotor shaft, or a helical gear is directly cut on the rotor shaft. In this case, the gear train connected to the gear provided on the rotor shaft (hereinafter referred to as the rotor shaft gear) has a higher rotational speed especially near the rotor shaft gear. Are connected and connected to a driven part in the image forming apparatus as an output of a constant rotation number required in the image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus includes an optical reading system that is an image reading unit, an image forming process unit disposed around a photosensitive drum, a sheet conveying unit, and a fixing unit that fixes an unfixed image to a sheet by pressing and heating. Has been. Each unit (driven part) constituting these image forming apparatuses is configured to operate by a driving device including an electric motor as a driving source and a gear train.

JP 2002-258563 A

  However, in the drive device of the conventional image forming apparatus, vibration may occur due to variations in gear accuracy or backlash of the gear train. If this vibration is remarkably large, the image forming process means including the photosensitive drum and the optical reading system as the image reading means, which are the driven parts, are affected by the vibration, and the image is blurred, and the image quality is low. May decrease. Moreover, there is a possibility that the operating noise of the apparatus becomes high due to the vibration.

  Timing is provided as drive transmission means for transmitting drive from the driving device to each unit (driven portion) in the image forming apparatus in order to improve the image quality and reduce the operating noise to provide a better quality image forming apparatus. There is an image forming apparatus that uses a belt to reduce the vibration. However, in order to transmit the drive from the drive unit to each unit by the timing belt, the ease of assembly of the timing belt is important. In this case, in order to make it easy to assemble the timing belt, a configuration in which a pulley to which the timing belt is attached protrudes from the drive device to facilitate connection to each unit is common. However, with this configuration, it is necessary to secure a large space for the timing belt inside the image forming apparatus, which hinders downsizing of the image forming apparatus.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to enable downsizing of an image forming apparatus, to realize a high quality image, and to achieve a better quality image forming apparatus with low operating sound. Is to provide.

  In order to achieve the above object, a typical configuration of the present invention includes a drive device that drives a plurality of load units in an image forming apparatus that forms an image on a sheet, and the drive device includes the first load unit. The first load driving unit that drives the second load unit and the second load driving unit that drives the second load unit, and the first load driving unit is accommodated in the second load driving unit so as to be able to transmit the drive. It is characterized by comprising.

  According to the present invention, the drive device that drives the plurality of load units in the image forming apparatus includes the first load drive unit that drives the first load unit and the second load drive unit that drives the second load unit. Since the first load drive unit is configured to be housed in the second load drive unit so as to be able to transmit drive, the assembly is easy as described above. The apparatus can be miniaturized.

  Further, in the above drive device, since any one of the plurality of load drive units is a belt drive, vibration can be reduced, and deterioration in image quality due to the vibration can be prevented. Operation noise due to vibration can also be reduced.

  Furthermore, even if any one of the load driving units is driven by a belt, the driving device is divided into a plurality of load driving units, so that the belt can be easily incorporated into the load driving unit. Therefore, it is not necessary to secure a wide space for making the belt easy to assemble as in the prior art, and the image forming apparatus can be downsized.

  Further, an input joint for inputting drive to the first load drive unit is provided, and an output joint for outputting drive to the second load drive unit and an output joint for coupling coupling with the input joint is provided. Although the drive transmission of the load drive unit can be reliably performed, the divided load drive unit can be easily mounted and divided, and the assemblability is further improved.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed according to the configuration of the apparatus to which the present invention is applied and various conditions. As long as there is no specific description, it is not the meaning which limits the scope of the present invention only to them.

[Schematic configuration of image forming apparatus]
First, the overall configuration of an image forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus according to the present embodiment forms an image on a sheet. As illustrated in FIG. 1, the image forming apparatus main body 100 includes an image forming unit 50 that forms an image as a second load unit, , And a registration roller pair 81 as a sheet conveyance unit that conveys a sheet as a first load unit. Further, the image forming apparatus main body 100 includes a document placing table 71 for placing a document, a light source 72 for irradiating light on the document placed on the document placing table 71, and a reading element (for reading reflected light from the document as image information). CIS: contact image sensor) 73, a feeding unit 60 that feeds the sheet toward the image forming unit 50, and the like.

  The feeding unit 60 includes cassettes (storage containers) 61 and 62 that store a recording target sheet S such as recording paper and are detachable from the apparatus main body 100, and each cassette 61 and 62 includes a sheet S. Feeding means 63 and 64 for feeding the sheets one by one are provided.

  The image forming unit 50 is provided with a cylindrical photosensitive drum 51 as an image carrier. Around the photosensitive drum 51, as a process means acting on the photosensitive drum 51, a primary charger 52 as a charging means for uniformly charging the drum surface, and a laser scanner device as an exposure means for forming a latent image on the drum surface. 53, a developing unit 54 as a developing unit that develops a latent image using toner, a transfer charger 56 as a transfer unit that transfers the toner image on the drum surface to the sheet S, and a deposit on the drum surface after transfer. A cleaner 55 is disposed as a cleaning means.

  On the upstream side of the image forming unit 50, a pair of registration rollers as a sheet conveying unit that corrects the skew of the sheet S fed from the feeding unit 60 and conveys the sheet S to the image forming unit 50. 81 is disposed. Further, on the downstream side of the image forming unit 50, a conveyance guide 82 for guiding the sheet S, a fixing device 83 for fixing the toner image to the sheet S, a discharge roller 84 for discharging the sheet S to the outside of the apparatus, and the like are disposed. Yes.

[Operation of Image Forming Apparatus]
Next, the operation of the image forming apparatus will be described. When a feeding signal is output from a control device (not shown) provided on the apparatus main body 100 side, the light reflected from the light source 72 and applied to the document placed on the document placement table 71 is read by a reading element (CIS). : Contact image sensor) 73 and replaced with an electrical image signal. This image signal is transmitted to the laser scanner device 53 and irradiated to the photosensitive drum 51 from a laser light emitting element (not shown) through the polygon mirror 53a and the lenses 53b and 53c. The photosensitive drum 51 is charged in advance by a primary charger 52, and an electrostatic latent image is formed by irradiation with light. The electrostatic latent image is visualized as a toner image by the toner in the developing device 54 being sent to the developing sleeve 54a and developed on the photosensitive drum 51 by the developing sleeve 54a.

  On the other hand, the sheet S fed from the feeding unit 60 is corrected in skew by the registration roller pair 81, and further sent to the image forming unit 50 at a proper timing. In the image forming unit 50, the toner image on the photosensitive drum 51 is transferred to the sheet S by the transfer charger 56. The sheet S that has received the transfer of the toner image is guided to the fixing device 83 by the conveyance guide 82, and the unfixed transfer image is permanently fixed to the sheet S by pressure and heating in the fixing device 83. Then, the sheet S on which the image is fixed is discharged from the apparatus main body 100 by a discharge roller 84.

  An image is formed on the sheet S fed from the feeding unit 60 through the above process, and the sheet S on which the image is formed is discharged out of the apparatus main body 100.

[Driver]
On the rear side of the image forming apparatus main body 100, a driving device 1 for driving a plurality of load portions in the image forming apparatus is disposed. In the present embodiment, as described above, as the plurality of load units in the image forming apparatus, the sheet conveying unit 81 is illustrated as the first load unit, and the image forming unit 50 is illustrated as the second load unit. That is, the driving device 1 according to the present embodiment includes a registration roller pair 81 as the sheet conveyance unit (first load unit), the photosensitive drum 51 that constitutes the image forming unit (second load unit) 50, and the like. A plurality of load portions in the image forming apparatus such as a developing sleeve 54 a included in the developing device 54 are driven.

  Next, the driving device 1 provided in the image forming apparatus main body 100 according to the embodiment of the present invention will be described with reference to FIGS. 2 is a perspective view of a state in which the driving device 1 (the cover is not shown) is attached to the rear plate (not shown) of the image forming apparatus main body 100, and FIG. 3 is the driving device 1 (the cover is not shown). 1) It is a perspective view of a single body. FIG. 4 is a perspective view in which the driving device 1 is divided.

  As shown in FIG. 4, the driving apparatus 1 according to the present embodiment forms an image as a second load driving unit that drives the image forming unit 50 (the photosensitive drum 51 and the developing sleeve 54a) as the second load unit. It is divided into a drive unit 25 and a registration drive unit 24 as a sheet conveyance drive unit that drives a sheet conveyance unit (registration roller pair 81) as the first load unit. Furthermore, the driving apparatus 1 according to the present embodiment is configured to accommodate the registration driving unit 24 in the image forming driving unit 25 so as to be able to transmit driving. In the present embodiment, as illustrated in FIG. 4, the image forming drive unit 25 includes a storage unit 25 a for storing the registration drive unit 24. The registration driving unit 24 is accommodated in the accommodating unit 25a of the image forming driving unit 25 so as to be able to transmit driving, and becomes an integrated driving device 1 as shown in FIGS. This will be described in detail below.

<Image drive unit>
First, the image forming drive unit 25 constituting the drive device 1 will be described. 2 and 3, the image forming drive unit 25 of the drive device 1 includes a DC motor 2 as a drive source, and a pulley 3 is processed in two stages on the rotor shaft of the DC motor 2. Drive is transmitted to the large-diameter pulley 4 and the registration pulley 9 via the timing belts 5 and 6.

  A drum shaft 7 is directly connected to one large-diameter pulley 4, and a drum coupling 8 is provided at the tip of the drum shaft 7. The drum shaft 7 and the drum coupling 8 are engaged with the flange portion 26 of the photosensitive drum 51, and a rotational force is applied to the photosensitive drum 51 by rotating the DC motor 2.

  A coupling gear 10 is directly connected to the other registration pulley 9, and a plurality of idler gears 11 are sequentially engaged with the coupling gear 10. Of the plurality of idler gears 11, the sleeve clutch gear 12 a of the sleeve clutch 12 is engaged with the most downstream idler gear, and the sleeve gear 13 is directly connected to the sleeve clutch 12. The sleeve gear 13 meshes with the sleeve gear 14 of the developing device 54, and a rotational force is applied to the sleeve gear 14 of the developing device 54 by rotating the DC motor 2. The sleeve gear 14 is directly connected to a developing sleeve 54 a included in the developing device 54, and the developing sleeve 54 a is rotated by rotating the sleeve gear 14.

<Registration drive unit>
Next, the registration driving unit 24 constituting the driving device 1 will be described. 2 and 3, the coupling gear 10 included in the image forming drive unit 25 and the coupling pulley 15 included in the registration drive unit 24 are directly connected by coupling coupling described later. Further, the coupling pulley 15 and the registration clutch pulley 19 of the registration driving unit 24 are directly connected by a timing belt 18.

  A registration roller shaft 81 a is connected to the registration clutch pulley 19. A registration gear 22a is connected to the end side of the registration roller shaft 81a, and a registration gear 22b is similarly connected to the end side of the other registration roller shaft 81b so that the gears 22a and 22b are engaged with each other. Then, by rotating the DC motor 2, a rotational force is applied to the registration roller shafts 81 a and 81 b via the registration pulley 9, the coupling pulley 15, and the timing belt 18. When a rotational force is applied to the registration roller shafts 81a and 81b, the registration rollers (registration roller pair 81) provided on the registration roller shafts 81a and 81b rotate.

  Further, among the divided load driving units constituting the driving device 1, one registration driving unit 24 is connected to the rear plate (not shown) of the image forming apparatus main body 100, as shown in FIG. It is incorporated at an earlier stage than the part 25. In the registration driving unit 24, a positioning pin 16 is provided on a registration plate 17 serving as a base of the registration driving unit 24, and the coupling pulley 15 is inserted into the positioning pin 16. Further, a belt tensioner 23 and a registration clutch pulley 19 are arranged on the registration plate 17, and the coupling pulley 15 and the registration clutch pulley 19 are connected by a timing belt 18. That is, the registration driving unit 24 is belt driven.

  An engageable D-cut (not shown) portion is formed on the outer diameter of the registration roller shaft 81a and the inner diameter of the registration clutch pulley 19, respectively. Accordingly, when the coupling pulley 15 is rotated, the registration clutch pulley 19 is rotated via the timing belt 18, and the rotation of the registration clutch pulley 19 is transmitted to the registration roller shaft 81a through the D-cut portion. 81 rotates.

<Coupling coupling>
Next, coupling coupling between the output joint of the image forming drive unit 25 and the input joint of the registration drive unit 24 constituting the drive device 1 will be described. FIG. 5 is a perspective view showing the positioning relationship between the registration driving unit 24 and the coupling gear 10 of the image forming driving unit.

  As shown in FIG. 5, the coupling pulley 15 serving as an input joint for inputting driving to the registration driving unit 24 is provided with a claw 15a. Further, in the coupling gear 10 as an output joint that outputs drive to the image forming drive unit 25, a positioning hole 10a for inserting the positioning pin 16 of the registration drive unit 24, and a coupling pulley of the registration drive unit 24 are provided. A groove 10b that engages with 15 (claw 15a) is provided. By engaging the coupling pulley 15 of the registration driving unit 24 and the coupling gear 10 of the image forming driving unit 25, the load driving units 24 and 25 are coupled and the position is determined.

  As described above, the driving device 1 that drives a plurality of load units (in this embodiment, a sheet conveying unit and an image forming unit) in the image forming apparatus main body 100 is driven, and the sheet conveying unit (registration roller pair 81) is driven. Since the registration driving unit 24 and the image forming driving unit 25 that drives the image forming unit 50 are divided, the assembly is easy, and the driving of the registration driving unit 24 into the image forming driving unit 25 can be transmitted. Since it is configured to be accommodated, the apparatus can be miniaturized while being easily assembled as described above.

  Further, a coupling pulley 15 that inputs driving to the registration driving unit 24 is provided, and a coupling gear 10 that outputs driving to the image forming driving unit 25 and is coupled to the coupling pulley 15 is provided. As a result, while the drive transmission of the divided load drive units 24 and 25 can be reliably performed, the load drive units 24 and 25 can be easily mounted and divided, and the assemblability is further improved.

  Moreover, since the registration drive unit 24 of the drive device 1 is a belt drive among the plurality of divided load drive units 24 and 25, it is possible to reduce vibrations due to gear variations and the like. It is possible to prevent the quality from being lowered and to reduce the operation sound due to vibration.

  Further, even if the registration driving unit 24 is belt driven as described above, the driving apparatus 1 according to the present embodiment is divided into the plurality of load driving units 24 and 25, so that the belt is incorporated into the registration driving unit 24. Easy. Therefore, in order to make it easy to assemble the timing belt as in the prior art, it is not necessary to secure a wide space for the timing belt, such as a pulley for attaching the timing belt to protrude from the driving device, and the size of the image forming apparatus can be reduced. Is possible.

  In the above-described embodiment, the configuration in which the registration driving unit 24 that drives the sheet conveying unit is divided from the driving device 1 is illustrated, but conversely, the image forming driving unit 25 that drives the image forming unit 50 is connected to the driving device 1. The same effect can be obtained by dividing and coupling with coupling bonds.

  Further, in the above-described embodiment, the coupling pulley 15 of the registration driving unit 24 is provided with the claw 15a, and the coupling gear 10 of the image forming driving unit 25 is provided with the groove 10b that engages with the claw 15a to couple the coupling. However, the present invention is not limited to this, and other configurations such as coupling coupling between claws or gears may be used.

Sectional drawing which shows the whole structure of the image forming apparatus which concerns on embodiment of this invention Schematic perspective view showing the periphery of the driving device of the image forming apparatus Schematic perspective view showing a driving device of the image forming apparatus The schematic perspective view which shows the state which divided | segmented the drive device of the said image forming apparatus Schematic perspective view showing a coupling coupling portion of a driving device of the image forming apparatus

Explanation of symbols

1 ... Drive device 2 ... DC motor (drive source)
3 ... pulley 4 ... large diameter pulleys 5 and 6 ... timing belt 7 ... drum shaft 8 ... drum coupling 9 ... registration pulley 10 ... coupling gear (output joint)
10a ... Positioning hole 10b ... Groove 15 ... Coupling pulley (input joint)
15a ... claw 16 ... positioning pin 18 ... timing belt 24 ... registration drive part (first load drive part)
25 ... Image forming drive unit (second load drive unit)
25a ... accommodating part 50 ... image forming part (second load part)
51 ... Photosensitive drum 54 ... Developer 54a ... Developing sleeve 81 ... Registration roller pair (first load portion)
81a, 81b ... registration roller shaft 100 ... image forming apparatus main body

Claims (4)

In an image forming apparatus for forming an image on a sheet,
A drive unit that drives the plurality of load units, and the drive unit is divided into a first load drive unit that drives the first load unit and a second load drive unit that drives the second load unit; In addition, the image forming apparatus is configured to accommodate the first load driving unit in the second load driving unit so as to be able to transmit the drive.   The first load drive unit is a sheet conveyance drive unit that drives a sheet conveyance unit that conveys a sheet as a first load unit, and the second load drive unit forms an image as a second load unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming drive unit that drives the image forming unit to be operated.   The image forming apparatus according to claim 1, wherein one of the plurality of divided load driving units is a belt drive.   An input joint that inputs drive to the first load drive unit is provided, and an output joint that outputs drive to the second load drive unit and that is coupled to the input joint is provided. The image forming apparatus according to claim 1.

Images