JPH05916Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a developing device in which toner remaining on a photoreceptor of an electrophotographic copying machine is collected by a cleaning device and the collected toner is utilized.

(Prior art) Conventionally, in a developing device that uses the collected toner of an electrophotographic copying machine, the collected toner is directly returned to the developer in the tank of the developing device, stirred by a stirring roller, and supplied to the developing roller. Unlike replenishment toner, this is toner that has passed through various conditions, so toner with various charges is mixed, and it is supplied to the developing roller without being properly charged just by stirring in the tank. However, there were problems such as toner scattering and background smearing.

(Purpose) The purpose of the present invention is to properly charge the collected toner collected from the cleaning section using the existing mechanism without adding a new mechanism, thereby preventing toner scattering and scumming.

(Structure) In order to achieve the above object, the present invention includes a developing device equipped with a toner replenishing section and a conveyance screw section, a cleaning device for cleaning the toner remaining on the photoreceptor after transfer, and a cleaning device for cleaning the toner collected by the cleaning device. In an electrophotographic copying machine equipped with a recycling device that recycles the developer scraped off by a doctor to the development agitator, a plurality of fins are installed on the upper surface of the agitation separator that slopes from the downstream side to the upstream side. The collected toner from the cleaning device falls from the opening on the upstream side of the agitation separator to the upstream side of the conveyance screw, and the drop opening to the agitation screw is opened in front of the upper surface of the agitation separator on the upstream side, and the toner is dropped from the upstream side of the agitation separator to the back of the downstream side of the conveyance screw chamber. The feature is that a discharge port is formed toward the agitator.

Hereinafter, a detailed description will be given based on examples. 1
2 is a photosensitive drum, 2 is a developing roller, and 3 is a developing tank, inside of which a stirring roller 4, a conveying screw 5, and a developing agitator 6 are arranged. A doctor 7 scrapes off the developer sent to the developing roller 2 to a certain height. Reference numeral 8 denotes an agitation separator that allows the developer scraped off by the doctor 7 to flow down to the development agitator 6, on the top surface of which a plurality of fins 9 are arranged side by side at predetermined intervals with an inclination of 30 degrees from the downstream side to the upstream side. A drop port 8a for the conveyance screw 5 is opened at the back on the upstream side. At the back of the downstream side of the transport screw chamber 10, there is a discharge port 11 facing the developing agitator 6.
is formed. 12 is a toner replenishment section, and 13 is a toner replenishment roller. The collected toner collected in the cleaning unit is sent to the front side of the machine by a screw 20 and falls into a pipe 21, and is further sent to the front side of the conveying screw 5 of the developing device by a screw 22 inside the pipe 21. There is.

Next, the effect will be explained. The developer in the developing tank 3 and the toner from the toner supply section 12 are mixed by the stirring roller 4 and sent to the developing roller 2. The developer adhering to the developing roller 2 is scraped off to a certain height by the doctor 7. The scraped off remaining developer falls onto the stirring separator 8 and falls along the oblique fins 9 from the downstream side to the upstream side.

Therefore, the developer in the developing tank 3 is scraped up by the stirring roller 4 and falls along the fins 9, and is sequentially sent from the downstream side to the upstream side, where horizontal stirring is performed. The developer that has fallen to the back of the upstream side of the stirring separator 8 falls into the conveyance screw 5 from the drop port 8a, and is sent to the downstream side together with the collected toner that has fallen to the back of the upstream side of the conveyance screw 5, where lateral agitation is carried out. It is done. There is a discharge port 11 at the back of the downstream side of the conveying screw 5, and the developer drops into the developer agitator 6 and is further agitated by the developer agitator 6. At this time, since the developer falling from the stirring separator 8 is also stirred together, the uncontrolled recovered toner is charged normally so that it can be used again for development, and density unevenness is eliminated.

(Effects) According to the present invention, there is a developing device equipped with a toner replenishing section and a conveying screw section, a cleaning device for cleaning toner remaining on the photoreceptor after transfer, and recycling of recovered toner collected by the cleaning device to the developing device. In an electrophotographic copying machine equipped with a recycling device, a plurality of fins are arranged in parallel from the downstream side to the upstream side on the top surface of the stirring separator, which allows the developer scraped off by the doctor to flow down to the development agitator. The collected toner from the device falls from the opening on the upstream side of the agitation separator to the upstream side of the conveyance screw, and a drop opening to the agitation screw is opened in front of the upper surface of the agitation separator on the upstream side. Since the discharge port is formed by the toner, the collected toner collected from the cleaning section can be properly charged using the existing mechanism without adding a new mechanism, thereby preventing toner scattering and scumming.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view of a developing device according to an embodiment of the present invention, FIG. 2 is a perspective view of a mechanism for sending recovered toner collected from a cleaning section to a conveying screw of the developing device, and FIG. 3 is a view similar to that shown in FIG. A partially cut away perspective view of the developing device, FIG. 4 is a front sectional view of the back side of the conveyance screw in FIG. 3, FIG. It is a diagram. 1...Photosensitive drum, 2...Developing roller, 3
...Developing tank, 4... Stirring roller, 5... Conveying screw, 6... Development agitator, 7... Doctor, 8... Stirring separator, 8a... Dropping port, 9... Fin, 10... Conveying screw room,
11...Discharge port, 12...Toner supply section, 13...
...Toner supply roller, 20, 22... Screw, 21... Pipe.

Claims (1)

[Scope of utility model registration request] An electrophotographic copying device equipped with a developing device including a toner replenishing section and a conveyance screw section, a cleaning device for cleaning toner remaining on the photoreceptor after transfer, and a recycling device that recycles the collected toner collected by the cleaning device to the developing device. In the machine, a plurality of fins are arranged in parallel from the downstream side to the upstream side on the top surface of the agitation separator that allows the developer scraped off by the doctor to flow down to the development agitator, and the toner collected from the cleaning device is transferred to the agitation separator. An electronic photograph showing a drop down to the upstream side of the conveying screw from the opening on the upstream side, a drop opening to the stirring screw in front of the upper upstream side of the stirring separator, and a discharge port toward the agitator at the back of the downstream side of the conveying screw chamber. A developing device that uses toner collected from copying machines.