JPH05268442A - Image forming device - Google Patents

Abstract

PURPOSE:To attain long service life and to prevent scattered toner by releasing drive of the image forming section with a drive release means when picture information is read by a read sensor so as to reduce wear of a drive part. CONSTITUTION:When picture information of an original is read, an original contained in a cassette paper feeder is read by a read sensor while the original is carried from a feeding roller 25 through a carrier path. Then, the original is discharged to a paper discharge section 21 by a branch guide 20. In this case, a changeover lever 41 of a gear 38 is switched, meshing between a rocking gear 40 and a gear 42 is released and the drive of the image forming section including a photosensitive body 6 is released and the drive is stopped. Then, only the carrier roller including the feeding roller 25 and a resist roller 5 is driven. Thus, the drive of the image forming section and the drive member of a fixing part not required for reading the original is stopped, wear of the driven part is reduced to attain long service life and scattering of toner is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a reading sensor such as a printer, a copying machine and a facsimile.

[0002]

2. Description of the Related Art A conventional image forming apparatus is disclosed in, for example, Japanese Patent Laid-Open No.
No. 166962, a facsimile machine (see FIG. 6) or a copying machine (see FIG. 7) known from Japanese Examined Patent Publication No. 2-17466 (see FIG. 7) is used to feed paper into the conveyance path 101 and the image forming unit 102. The transport path 103 for transporting and forming an image is configured independently. Since such a conventional apparatus requires two transport paths, there is a problem in that the apparatus becomes large and the price becomes high accordingly.

Although not yet known, the applicant of the present invention configures a small apparatus, and therefore, a sheet is used to form an image on a sheet in a conveyance path for reading image information of a document by a reading sensor and an image forming unit. An image forming apparatus has been proposed in which the conveying path for conveying is formed as one conveying path in common.

When an electrophotographic system is used in the image forming section,
When a document is passed through the conveying path for image reading, the image forming unit is also driven. When many images are read from the original, image formation is not performed, so the image forming unit, which is not actually needed, is also driven, and the photoconductor, cleaning blade, developer, bearing, gear However, there is a problem in that the wear of the above components becomes so severe that the life is shortened, and further, the developing roller rotates and the toner is scattered even when not developing.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide an image forming apparatus having a long-life, small-sized and low-priced reading sensor.

[0006]

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems by a reading sensor, an image forming section for forming an image based on an image information signal from the reading sensor, and a sheet feeding section to an image forming section. And a conveyance path for conveying to the conveyance path, the reading sensor is arranged between the sheet feeding unit and the image forming section of the conveyance path, and the conveyance branch to the conveyance path between the reading sensor and the image forming section. The image forming apparatus provided with a path is provided with a drive canceling unit that arbitrarily cancels the driving of the rotating member of the image forming unit during the reading operation of the reading sensor.

[0007]

According to the present invention, when the reading operation of the image information is performed by the reading sensor, the driving of the image forming section is canceled and stopped by the driving canceling means. A small device that has been stopped and that has reduced wear of the driving part and has a long life is obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described based on the embodiments shown in the drawings.

In an electrophotographic printer as an example of an image forming apparatus, as shown in FIG. 1, a recording sheet 2 is fed from a cassette sheet feeding apparatus 1 to a registration roller pair 6 through a feeding path 3 and a conveying path 4. Sent. The recording paper 2 is sent to a latent image carrier composed of a drum-shaped photoconductor 6 at a timed timing by a pair of registration rollers 5.

The photosensitive member 6 is rotationally driven counterclockwise in the figure, the surface of the photosensitive member 6 is charged by the charging charger 7, and a laser beam from the laser optical system 8 is irradiated to form an electrostatic latent image on the surface. ..

When the electrostatic latent image passes through the developing device 9, it is developed with toner by the developing roller 10 to be visualized,
The visible image is transferred to the recording paper 2 by the transfer charger 11, and the transferred visible image of the recording paper is fixed by the fixing device 12. The fixed recording paper is discharged and stored in the first paper discharge unit 13.

On the other hand, the residual toner on the photoconductor 6 after the transfer is removed by the cleaning device 14, and the removed toner is collected in the toner collecting tank 15.

A reading sensor 16 is arranged along the conveying path 4, a timing roller pair 17 is provided in front of the reading sensor 16 in the conveying path 4, and a feed roller pair 18 is provided after the reading sensor 16 if necessary. Be done.

A conveyance branch path 19 is provided in the conveyance path 4, for example, after the registration roller pair 5 (may be before), and a branch guide 20 allows a sheet passing through the conveyance path 4 to face the photoconductor 10. , Direction switching to the direction toward the transport branch path 19. The paper sheet passing through the conveyance branch path 19 can be discharged and stored in the second paper discharge unit 21.

When the image information of the original is read, the original stored in the cassette sheet feeding device 1 passes through the feeding path 3 and is read while being conveyed by the timing roller pair 17 in the conveying path 4 at a timing. It is read by the sensor 16. The document that has passed through the reading sensor 16 and has been read is guided to the conveyance branch path 19 by the branch guide 20 and discharged to the second paper discharge unit 21. Therefore, the document is discharged without coming into contact with the photoconductor 6.

When an image is formed by the image information read by the reading sensor 16 or by the image information sent from another host device, the paper accommodated in the cassette paper feeder 1 is switched from the original to the recording paper.

The recording paper fed from the cassette paper feeding device 1 is fed by the registration roller pair 5 (however, the reading sensor 16 does not operate) in the same manner as in the case of the above-mentioned original, and the branch guide 20 is switched at that time. Then, the image is formed on the photoconductor 6 by transfer from the photoconductor 6, is fixed by the fixing device 12, and is discharged to the first discharge unit 13.

The passages up to the front of the branch guide 20 of the feeding path 3 and the conveying path 4 are shared both when reading a document and when forming an image on a recording sheet.

A manual paper feeding device 22 is provided in the conveying path 4 so that a small amount of recording paper or manuscript can be manually fed to the front of the timing roller pair 17 addressed to one sheet.

The image forming unit includes a photosensitive member 6, a developing roller 10 of the developing device 9, a toner stirring member 23 of the developing device 9, a stirring member 24 and the like, which are driven to rotate.

At the time of reading the original, the original is not sent to the image forming section, but is discharged to the second discharge section 21 by the transport branch path 19. Generally, in a printer, each rotary member is configured to be driven by one drive motor through a gear train or the like. Therefore, when a sheet is fed from the cassette sheet feeding unit 1, the image forming unit is included. All the members are driven, and even when the document is read, the rotating members of the image forming unit are driven even though they are not necessary, and the wear and toner scattering of each member is unnecessary. Will occur.

Therefore, as shown in FIG. 2, the drive motor 31
Various rotating members such as the registration roller 5, the photoconductor 6, the developing sleeve 10, and the fixing roller 12 of the fixing device 12.
A gear train is formed to drive a, the timing roller 17, the feed roller 18, the toner stirring member 23, the stirring member 24, the feeding roller 25 provided in the feeding path 3, and the like.

The tamming roller 17 and the feeding path roller 25 are driven by the first gear train 34 composed of a plurality of gears sequentially meshing with the first gear 33 that meshes with the drive gear 32 provided in the drive motor 31 to drive the drive gear 32. Second bite
The gear 35 has a second gear train 36 that drives the feed roller 18.
, The gear of the third gear train 37 that drives the toner stirring member 23 and the registration roller 5, and the gear of the switching gear device 38 are in mesh with each other.

Switching gear device 38 constituting drive release means
2 and 3, a stationary gear 39 that meshes with the second gear 35 and an oscillating gear 40 that meshes with the stationary gear 39.
And one end of which is rotatable around the axis of the fixing gear 39, and the other end of which is a lever 4 which rotatably supports the swing gear 40.
1 and. The switching lever 41 is held in the first position by the spring 47, and when the solenoid 48 connected to the switching lever 41 is energized, it moves to the second position against the force of the spring 47, and the solenoid 48 is deenergized. Then, the spring 47 swings to the first position. Other actuators may be used instead of the solenoid. First of the switching lever 41
At the position, the third gear 42 meshing with the oscillating gear 40 is fixed, and at the second position of the switching lever 41, the oscillating gear 40 is disengaged from the third gear 42 and is in a free state.

A fourth gear train 43 for driving the stirring member 24 and the developing sleeve 10 and a fourth gear 44 mesh with the third gear 42.

A fifth gear for driving the photoconductor 6 is provided on the fourth gear 44.
The gear train 45 and the sixth gear train 46 that drives the fixing roller 12a are in mesh with each other.

When the recording paper is fed from the cassette paper feeding device and the image is formed by the image forming portion, the switching gear device 3 is used.
8 of the switching gear 41 to the first position,
Is engaged with the third gear 42 so that all the rotating members can be driven.

When the original is fed and read, the switching lever 41 of the switching gear device 38 is switched to the second position, and the oscillating gear 40 is disengaged from the third gear. The developing sleeve 10, the agitating member 24, and the fixing roller 12a are released from driving, and only the rollers such as the feeding roller 25, the timing roller 17, the feeding roller 18, and the registration roller 5 necessary for conveying the original document to the second discharging portion 21. Switch to driving.

With this configuration, when the image of the original is read by the reading sensor 16, the image forming unit and the fixing device are stopped, the photosensitive member and other rotating members are prevented from being rotated unnecessarily, and abrasion is prevented. Is reduced, the life is improved, and toner scattering is prevented.

The above-mentioned gear train is an example, and can be appropriately recombined as long as the necessary members of the image forming unit can be stopped in driving when reading the original.

In the case of the electrophotographic system as shown in FIG. 1, it may be preferable to stop not all the constituent elements of the image forming section but only a part thereof when reading the original. For example, in the developing device 9, it may be preferable to replenish the toner or agitate the toner and the developer during the reading operation in order to improve workability in preparation for the next image formation. Particularly in the case of a developing system using a two-component developer, the toner and the developer are stirred after the toner is replenished. Therefore, for example, it is preferable that the toner agitating member 23 and the agitating member 24 are kept in the driving state even during the reading operation, and the driving can be independently released when necessary. Further, in the fixing device 12, it is preferable that the cleaning of the fixing roller 12a is performed during the reading operation and stopped immediately after the cleaning is completed.

In this case, a member which is desired to be rotationally driven even during the reading operation is constituted so that it can be always driven by the drive motor 31 through the gear train, and only the member which needs to be stopped appropriately as shown in FIG. An electromagnetic clutch 52 is attached to the shaft 51 as an independent drive release member, and a driven gear 54 that meshes with a gear 53 of an arbitrary gear train is rotatably attached to the shaft 51. When the electromagnetic clutch 52 is energized, the driven gear 5 is driven.
4 and the electromagnetic clutch 52 are connected, the shaft 51 rotates,
When the electromagnetic clutch 52 is deenergized, the connection of the electromagnetic clutch 52 is released, the shaft 51 is stopped, and the rotating member provided on the shaft 51, for example, the stirring member 24 or the like can be stopped.

As the independent drive releasing member, in addition to the above-mentioned row of electromagnetic clutches 52, for example, the switching gear device 3 shown in FIG.
It is also possible to utilize 8 to independently release the drive and arrange the oscillating gear 40 so as to engage with the gear fixed to the shaft of the rotating member.

As shown in FIG. 5, the switching gear 38 is replaced with a mere stationary gear train, and all rotating members can be constantly driven by a drive motor. The shafts of members such as the photoconductor 6 and the developing sleeve 10 which are desired to be stopped individually. 4 is provided with an electromagnetic clutch, or a device as shown in FIG. 3 or a device similar to this is arranged at a position related to the stopped rotating member, and a necessary member is provided when necessary. It is also possible to stop them individually.

[0035]

As described above, according to the present invention, the conveying path of the original document read by the reading sensor is also used as the conveying path for conveying the recording paper to the image forming section, and only one paper feeding device and one conveying device are required. It has become possible to reduce costs and reduce costs. Further, during the reading operation, the driving of a part or all of the members forming the image forming apparatus can be released and stopped, the life of the parts can be extended, and the toner scattering can be prevented.

By stopping the photoconductor of the image forming member at the time of reading, the life of the photoconductor and the cleaning blade can be extended.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of an image forming apparatus according to the present invention.

2 is a schematic diagram of a drive system of the apparatus of FIG.

FIG. 3 is a diagram showing an example of a structure of a switching gear device.

FIG. 4 is a schematic sectional view of an apparatus for independently stopping a rotating member.

5 is a schematic view of another example of the drive system of the apparatus of FIG.

FIG. 6 is a schematic diagram of a conventional image forming apparatus.

FIG. 7 is a schematic view of another conventional image forming apparatus.

[Explanation of symbols]

 1 Paper Feeding Section 4 Conveying Path 6 Photoreceptor (Image Forming Section) 10 Original Sleeve (Image Forming Section) 16 Reading Sensor 19 Conveying Branch Path

Claims (2)

[Claims] 1. A reading sensor comprising: a reading sensor; an image forming unit that forms an image based on an image information signal from the reading sensor; and a conveyance path that conveys a sheet from a paper feeding unit to the image forming unit. An image forming apparatus in which a conveyance branch path is provided on the conveyance path between the reading sensor and the image forming section, An image forming apparatus comprising drive release means for arbitrarily releasing the drive of the rotating member of the image forming unit during the reading operation of the sensor. 2. The image forming unit is formed as an electrophotographic image forming unit, and the drive canceling unit is formed as a unit that arbitrarily cancels driving of at least a part of the image forming unit. Item 1. The image forming apparatus according to Item 1.