JP2008233698A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: if a developer carrier is rotated with no developer or little developer between the developer carrier surface and developing blade of a developing device when a developer supply container is not attached to the developing device, the developer carrier surface or developing blade is damaged resulting in image failure. <P>SOLUTION: The developer supply container is freely attached to and detached from the developing device. When this supply container is attached to the developing device, the driving part of the main body and a coupling gear located at the end of the developer supply container are coupled. A gear train is rotated by the rotation of the coupling gear, and the developer carrier is consequently rotated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is used in the field of image forming technology such as an electrophotographic copying apparatus and an information recording apparatus. In particular, a latent image formed on an electrostatic latent image carrier is visualized with a developer, and this image is transferred to a transfer material. The present invention relates to an image forming apparatus that obtains an image by applying a transfer electric field thereon, and in particular, replenishes the developer by attaching and detaching a developer supply container containing the developer to the image forming apparatus. It is related with the apparatus to do.

  In an image forming apparatus such as a copying machine or a printer, a developer is consumed every time an image is formed. Therefore, the user needs to replenish the developer into the developer container.

  Since the developer is usually a particle of several microns, there is a problem that the developer scatters during the operation of transferring the developer in the developer supply container to the developer container and stains the surroundings.

  In view of this, there has conventionally been provided a developing device in which the developer supply container for containing the developer is attached to the developing device and replaced with the developer supply container.

  In recent years, for the purpose of improving maintainability, a process cartridge system in which image processing components such as a developing device and a photosensitive drum as an image carrier are integrated is often used.

  The cartridge includes a photosensitive drum as an image carrier, a charging device for equalizing the potential on the photosensitive drum, and a cleaning blade made of an elastic body for cleaning the remaining developer on the photosensitive drum. A developing blade made of an elastic body for pressing the cleaner device, the developer carrying member, and the developer carrying member in the rotating direction to uniformize the developer thickness on the developer carrying member, and developing in the vicinity of the developing blade A developing device having a remaining amount detecting means for detecting the remaining amount of the agent is provided.

  Now, due to the recent demands for downsizing and cost reduction of image forming apparatuses, only one main body drive motor is usually provided, and one motor drives all of the main body system.

  At that time, the developer sealed in the developer supply container is supplied to the developer container from an opening provided in the developer supply container by rotating a stirring member disposed in the developer supply container.

  The rotational driving force of the stirring member is obtained by obtaining the rotational driving of the photosensitive drum of the process cartridge from the driving unit of the image forming apparatus main body, and transmitting the driving to the developer carrying member in the developing device by the rotational force of the photosensitive drum. Then, it is transmitted to the stirring member through the drive train.

  Usually, the stirring member is also rotated by the pre-rotation at the start-up of the image forming apparatus and the developer is replenished from the developer replenishing container to the developer container.

  When there is very little residual developer in the developer container, for example, when the developer supply container is installed for the first time, it is necessary to supply a sufficient amount of developer into the developer container. It is necessary to increase the rotation of the stirring member.

  As a method for determining whether or not the supply of the developer into the developer container is sufficient, a method of detecting from the signal of the developer detection means has been proposed.

JP-A-5-46027

  The developer replenishment container is detachable from the developing device, and the developer replenishment container is not attached to the developing device by the user at the initial stage of installing the image forming apparatus or when the developer container has a small amount of developer. In order to transport the developer from the developer supply container to the developer container when the power is turned on, the stirring member in the developer supply container is rotationally driven for a longer time than usual.

  When there is little developer in the developer container or in the developer container, the developer detection means is always in a state where there is little or no developer as a lubricant between the surface of the developer carrying member and the developing blade. It is detected that the developer is insufficient, and the idling is continued for a long time.

  As a result, the developing blade and the surface of the developer carrying member are damaged. After the above-described state, even if the developer bottle is normally attached and filled with toner, the surface of the developing blade and the developer carrying member is damaged, so that the image has a problem such as vertical white stripes and uneven density. Cause it to occur.

  Also, because the developer supply container of the developing device with the largest load and load fluctuation in the process cartridge is in the same drive train as the photosensitive drum, rotation irregularity of the photosensitive drum occurs, and a lot of fine stripes are generated laterally. It will also cause.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of obtaining a good image with a simple configuration and eliminating an image defect due to an erroneous operation.

  According to a first aspect of the present invention, there is provided a developer container for containing a developer, a developer supply container for supplying developer to the developer container, and an image forming apparatus main body at an end position in a longitudinal direction of the developer supply container. A coupling gear that receives rotational driving from the driving unit, a rotatable developer carrier having a magnetic body for adhering the developer to the surface, and a developer carrying rotational driving of the coupling gear In a developing device used in an image forming apparatus having a gear train that is transmitted to a body, the developer supply container is detachable from the developing device, and when the developing device is mounted, the main body is driven. A developing device for use in an image forming apparatus, wherein the gear train is rotated by rotation of the coupling gear, and the developer carrier is rotated.

  According to a second aspect of the present invention, in the developing device used in the image forming apparatus according to the first aspect, the coupling gear is connected to the drive unit of the main body, and is configured by a coupling unit and a gear unit that receive rotational driving. It is characterized by.

  According to a third aspect of the present invention, in the developing device used in the image forming apparatus according to the first or second aspect, the rotatable stirring member for stirring the developer and transporting the developer to the developer container is the gear portion. It is connected, It rotates by the rotational drive, It is characterized by the above-mentioned.

  According to a fourth aspect of the present invention, there is provided an image forming apparatus comprising the developing device used in the image forming apparatus according to any one of the first, second and third aspects, and forming a desired image.

  When the developer supply container is not attached to the developing device, the developer carrier is turned off, so that even if the user turns on the power without attaching the developer supply container, the developer carrier or developer It is possible to provide a good image without damaging the blade surface.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic diagram showing an internal structure of a printer 10 as an example of an image forming apparatus including a process cartridge in which a developing device of the present invention is incorporated.

  The printer 10 is provided with a universal cassette 16 in which a plurality of cut sheets are accommodated so as to be freely inserted into and removed from the main body of the printer 10.

  The right side wall of the printer 10 is provided with a rectangular manual feed tray 18 capable of feeding small-size recording paper such as postcards.

  The manual feed tray 18 rotates in the direction of arrow A about the lower side 18a and opens to a position where the recording medium can be placed (position indicated by a two-dot chain line). Further, on the upper surface of the printer 10, there is provided a paper discharge tray 20 on which recording materials on which images are formed are stacked.

A procedure for forming an image with the printer 10 will be described.
Image information is transmitted to the printer 10 from an image information output device (not shown), and is sent as an electrical signal to a well-known laser irradiation device 29 by an electronic signal converter (not shown), at the corresponding laser irradiation timing. Laser light (one-dotted oblique line) 29a is applied to the photosensitive drum 32, which is an image carrier uniformly charged by the charging roller 30, so that an electrostatic latent image is formed on the photosensitive drum 32.

  The electrostatic latent image is developed with toner supplied from the developing device 50 to form a toner image.

On the other hand, the recording material is fed from the universal cassette 16 in the direction of arrow B, conveyed by the transfer roller 36, and the toner image is transferred to the recording medium.
The recording material onto which the toner image has been transferred is conveyed to the fixing device 40. The fixing device 40 is provided with a heat roller 42 and a press roller 44. The recording medium is conveyed while being sandwiched between the two rollers 42 and 44, and the toner image is fixed on the recording medium.

  The recording material on which the toner image is fixed in this manner is discharged and stacked on the discharge tray 20.

  The toner image remaining on the photosensitive drum 32 after the transfer is scraped off by the cleaning device 46.

  Further, the recording material can be fed from the manual feed tray 18, and the procedure for forming an image on the recording material fed from the manual feed tray 18 is the same as described above.

As described above, various components and members are incorporated in the printer 10, and among these components, the charging roller 30, the photosensitive drum 32, the cleaning device 46, and the developing device 50 are integrally formed and processed. The cartridge 100 is configured.
The process cartridge 100 can be detachably mounted inside the printer 10.

  Further, a toner bottle 200 that is a developer supply container in which toner is sealed is detachable from the developing device 50.

FIG. 2 is a schematic diagram showing the process cartridge 100.
The toner bottle 200 is provided with an opening 201 for supplying the toner T to the developing device, and the toner T is sent out by rotating a stirring member 202 that is rotatable in the direction C in the drawing.

The delivered toner T is supplied to a developing sleeve 203 which is a developer carrying member provided with a magnetic material therein, and a developing blade 204 made of an elastic body pressed from the counter direction is brought into contact with the developing sleeve 203. Thus, the coating is performed to a uniform thickness.
In the vicinity of the contact portion of the developing blade 204, a known wire-like remaining amount detecting member 205 is arranged in the entire longitudinal direction of the developing device, and the image forming device receives the signal from the remaining amount detecting member 205 into the CPU 47 and develops it. The toner remaining amount in the developing chamber of the apparatus 50 can be detected.

FIG. 3 is a schematic perspective view showing a method of attaching the toner bottle 200. As shown in FIG.
An opening 10a for attaching and detaching the toner bottle 200 is provided on the front surface of the printer 10, and a coupling gear 206 connected to the stirring member 202 of the toner bottle 200 and connectable to a main body drive (not shown) It is inserted toward the developing device 50 (in the direction of arrow C in the figure).
FIG. 4 is a schematic cross-sectional view of a toner bottle.
As described above, the agitating member 202 is provided in the toner bottle 200. The agitating member 202 is coupled with a coupling gear 206 and a sealing material 207 that are rotatably mounted outside the toner bottle 200. ing.

  The coupling gear 206 includes a coupling portion 206b having a slit that receives the drive of the main body by fitting with the gear portion 206a and the main body of the image forming apparatus (not shown). The stirring member 202 attached to the main body and receiving the rotational drive by the coupling part 206b is simultaneously rotated with the gear part 206a.

Next, the drive transmission of the process cartridge 100 when the toner bottle 200 is attached will be described with reference to FIG.
FIG. 5 is a drive system diagram showing the drive train 300 in the process cartridge 100.
The process cartridge 100 is provided with two systems of drive trains. One of the process cartridges 100 rotationally drives the photosensitive drum 32 that is driven via the coupling 301 from the main body.
The other is input to the toner bottle 200 from the main body drive via the coupling unit 206b, and the input drive rotates the stirring member 202 in the toner bottle 200.
Further, a gear portion 206a connected to the thrust direction end of the agitating member 202 is connected to a gear train 303 for decelerating the developing device, and rotational driving is transmitted to the developing sleeve 203.
Next, FIG. 6 shows the state of the drive train when the toner bottle 200 is not attached.
When the toner bottle 200 is not attached, the rotational drive to the developing sleeve 203 is cut off, and the developing sleeve 203 does not rotate even when the main body is driven, and the surface of the developing sleeve 203 and the developing blade 204 is not damaged. Can be prevented.

  Further, since the toner bottle 200 having a large load is not provided in the same series of driving as the photosensitive drum 32, it is possible to suppress the rotation unevenness of the photosensitive drum 32.

Schematic diagram showing the internal structure of a printer which is an example of an image forming apparatus provided with a process cartridge incorporating a developing device Schematic diagram showing process cartridge Schematic perspective view showing how to install a toner bottle Cross section of toner bottle Drive system diagram showing drive train in process cartridge State of drive train when toner bottle is not installed

Explanation of symbols

10 Printer
100 process cartridge
200 toner bottle (developer supply container)
202 Stirring member
203 Development sleeve (developer carrier)
204 Developing blade
206 Coupling gear
206a Coupling part
206b Gear section
300 drive train
301 coupling

Claims (4)

  A developer container for containing the developer, a developer supply container for supplying the developer to the developer container, and a rotational drive from the drive unit of the main body of the image forming apparatus at the end position in the longitudinal direction of the developer supply container. A coupling gear for receiving, a rotatable developer carrier having a magnetic body for adhering the developer to the surface, and a gear train for transmitting rotational driving of the coupling gear to the developer carrier; In the developing device used in the image forming apparatus, the developer supply container is detachable from the developing device, and when mounted on the developing device, the driving unit of the main body, the coupling gear, Are connected to each other, and the gear train is rotated by the rotational drive of the coupling gear to rotate the developer carrier, and the developing device used in the image forming apparatus.   The developing device for use in an image forming apparatus according to claim 1, wherein the coupling gear is configured by a coupling portion and a gear portion which are coupled to a driving portion of the main body and receive rotational driving.   The image according to claim 1, wherein a rotatable stirring member for stirring the developer and transporting the developer to the developer container is connected to the gear portion and is rotated by its rotation drive. Development device used for forming device.   An image forming apparatus comprising the developing device used in the image forming apparatus according to claim 1, and forming a desired image.

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