JPH06161247A - Electrophotographic recorder - Google Patents

Abstract

PURPOSE:To accurately detect the depletion of toner in a developing device in an electrophotographic recorder. CONSTITUTION:An exclusive driving motor 41 driving only the agitator 39 of the developing device 14 is provided in addition to a main driving motor 40, and the respective driving motors 40 and 41 are respectively controlled and driven by a control means 42. The driving force of the motor 40 is transmitted to gears 44 and 45 on the developing device 14 side through a transmission gear 43, and transmitted to a developing roller 35 from the gear 44 through a 1st clutch 46, then transmitted to a toner replenishing member 38 from the gear 45 through a 2nd clutch 47 so as to drive the respective parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, a copying machine, a facsimile, etc. using a laser, charging, optical writing,
The present invention relates to an electrophotographic recording device that records on a sheet by an electrophotographic process such as development and transfer.

[0002]

2. Description of the Related Art Conventionally, for example, in a laser printer, a developing roller is provided with a developing roller, a toner replenishing member for replenishing toner to the developing roller, and an agitator for feeding toner from a toner chamber toward the developing roller. There is one that develops a latent image on a photoconductor by adhering toner with the developing roller.

In this type of laser printer, for example, as shown in FIG. 6, the driving force of the main drive motor 1 of the main body of the apparatus is transmitted to the developing device side via the transmission gear 2 and the gears 3, 4 and 5 are respectively transmitted. It is driven by being transmitted to the developing roller 6, the toner replenishing member 7, and the agitator 8 via the.

In some of such laser printers, the load torque of the main drive motor 1 is measured and the toner end of the toner chamber is detected based on the torque fluctuation.

[0005]

However, in such a conventional laser printer, not only the gears 2 to 5 but
Since the load torques of a large number of members such as the developing roller 6, the toner replenishing member 7, and the agitator 8 are applied to the main drive motor 1, the load torque of the main drive motor 1 is also changed by the load torque fluctuations of the members other than the agitator 8. fluctuate. Therefore, there is a problem that the toner end cannot be accurately detected by measuring the load torque of the main drive motor 1.

Therefore, an object of the present invention is to enable accurate toner end detection in an electrophotographic recording apparatus.

[0007]

Therefore, the present invention provides
For example, as shown in the illustrated embodiment below, the developing roller 3
5, a toner replenishing member 38 for replenishing toner thereto, and an agitator 39 for feeding toner toward the developing device 1.
4, an electrophotographic recording apparatus in which toner is attached by the developing roller 35 of the developing device 14 to develop a latent image on the photoconductor 12 is provided with a dedicated drive motor 41 for driving the agitator 39. It is characterized by

According to a second aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the first aspect, the toner replenishing member 38 is provided at the start of driving.
And a control unit 42 for rotating the developing roller 35 after driving the agitator 39.

According to a third aspect of the present invention, for example, as shown in the following illustrated embodiment, in the electrophotographic recording apparatus according to the first aspect, the toner replenishing member 38 is provided at the end of driving.
And a control means 42 for stopping the rotation of the developing roller 35 after the driving of the agitator 39 is stopped.

[0010]

In the present invention, during development, the agitator 39 of the developing device 14 is driven by the dedicated drive motor 42.

According to the second aspect of the present invention, when the drive is started, the toner replenishing member 38 and the agitator 39 are driven by the control means 42, and then the developing roller 35 is rotated.

According to the third aspect of the invention, at the end of the driving, the driving of the toner replenishing member 38 and the agitator 39 is stopped, and then the rotation of the developing roller 35 is stopped.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is a schematic diagram of the overall configuration of a laser printer which is an embodiment of the present invention.

Reference numeral 10 in the figure denotes the apparatus main body. A belt-shaped photoreceptor 12 is provided in the main body 10 of the apparatus at substantially the center thereof. Around the photoconductor 12, a charging device 13, a developing device 14, and a transfer device 1 are arranged in this order in the driving direction indicated by the arrow.
5. A cleaning device 16 is arranged. And the charger 1
3 and the optical writing device 18 is arranged below the cleaning device 16, and the paper feeding cassette 19 is attached diagonally above the developing device 14.

Then, the sheet is fed from the sheet feeding cassette 19 by the sheet feeding roller 20, and the registration roller pair 21
Then, it is conveyed to the upper side of the photoconductor 12 at a proper timing. The photoconductor 12 is driven in the counterclockwise direction indicated by the arrow, and at that time, the surface of the photoconductor 12 is uniformly charged by the charger 13, and the photowriter 18
To form an electrostatic latent image on the photoconductor 12. When the latent image passes through the position of the developing device 14, toner is attached thereto to form a visible image. Then, this visible image is transferred onto the lower surface of the sheet conveyed to the upper side of the photoconductor 12 by the transfer unit 1.
Transfer at 5. The post-transfer sheet is guided by the conveyance guide 23 and conveyed to the fixing device 17, where the visible image is fixed. Then, the sheet coming out of the fixing device 17 is further discharged by the paper discharge roller 24.
The sheet is conveyed to the sheet discharge section 25, guided by the sheet discharge guide 26, and stacked on the sheet discharge tray 27.

By the way, the above-mentioned developing device 14 is provided so as to be replaceable with respect to the apparatus main body 10. As shown in FIG. 4, each part is provided in a developing device case 30, a toner container 31, and a waste toner collecting container 32. Be prepared for. Developer case 30
As shown in FIG. 5, a developing chamber 33 is formed therein, and a toner chamber 34 for accommodating toner is formed in the toner container 31. Then, in the developing chamber 33, the photoconductor 1
The roller window 30a is opened on the second side, and the developing roller 35 is rotatably provided in contact with the photoconductor 12 through the roller window 30a. Then, on the surface of the developing roller 35,
The tip of the static elimination brush 36 is pressed from the upper right side in the figure, and the tip of the thin layer blade 37 is pressed from the lower left side. A toner supply member 38 for supplying toner to the developing roller 35 is rotatably provided near the toner chamber 34.

In the toner chamber 34, an agitator 39 is rotatably supported around a support shaft 39a.

At the time of development, the developing roller 35, toner replenishing member 38, and agitator 39 are rotated as indicated by arrows in FIG. Then, the agitator 39
Is stirred and sent out from the toner chamber 34 into the developing chamber 33. The toner fed into the developing chamber 33 is replenished to the surface of the developing roller 35 by the toner replenishing member 38. The replenished toner is blocked by the tip of the thin layer blade 37 to form a thin layer and is rubbed to be charged. Then, a part of the toner is electrostatically attached to the surface of the photoconductor 12 by the developing roller 35, and the electrostatic latent image on the surface of the photoconductor 12 is visualized. On the other hand, the toner remaining on the developing roller 35 is discharged by the discharging brush 36.

As shown in FIG. 1, the laser printer of the present invention is provided with a main drive motor 40 inside the apparatus main body 10 and a dedicated drive motor 41 for driving the agitator 39. The drive control of 41 is performed by the control means 42. The main drive motor 40 on one side
It is transmitted to the developing device 14 side via the transmission gear 43, and further, via the gear 44 and the gear 45, the developing roller 35 is transmitted.
And to the toner supply member 38. A first clutch 46 is provided between the gear 44 and the developing roller 35, and a second clutch 47 is provided between the gear 45 and the toner replenishing member 38. Then, the clutches 46 and 47 are controlled by the control means 42 to be connected and disconnected.

In the laser printer of the present invention,
At the start of driving, as shown in FIG. 2, for example, by turning on the power of the apparatus main body 10, the control means 42 turns on the main drive motor 40 and the dedicated drive motor 41 and operates the second clutch 47. Then, the toner replenishing member 38 and the agitator 39 are driven to adhere the toner to the surface of the developing roller 35. Then, after a lapse of a predetermined time, the first clutch 46 is operated to rotate the developing roller 35 to which the toner is attached.

On the other hand, at the end of driving, as shown in FIG. 3, for example, by turning on the power source of the apparatus main body 10, the control means 42 turns off the dedicated drive motor 41 and turns off the second clutch 47. Then, the driving of the toner replenishing member 38 and the agitator 39 is stopped to stop the sending of the toner and the replenishment thereof. Then, after a predetermined time has passed, the main drive motor 40 is turned off to stop the rotation of the developing roller 35. As a result, the toner replenishment is stopped, the developing roller 35 is rotated, and the toner adhering to the toner is removed by the charge removal brush 36.

[0022]

Therefore, according to the present invention, in the electrophotographic recording apparatus in which the developing roller, the toner replenishing member and the agitator are provided in the developing device, the dedicated drive motor for driving the agitator is provided. By detecting the toner end based on the torque fluctuation,
The toner end can be detected more accurately without being affected by the load torque other than that of the agitator. Further, according to the present invention, the load torque of the drive motor that drives something other than the agitator can be reduced, and thereby the drive motor can be downsized and the cost can be reduced.

According to the second aspect of the invention, when the driving is started, the toner replenishing member and the agitator are driven to adhere the toner to the developing roller, and then the developing roller is rotated. It is possible to prevent the toner from already adhering to the surface and the generation of abnormal noise between the thin layer blade and the like pressed against the surface.

According to the third aspect of the present invention, at the end of driving, the driving of the toner replenishing member and the agitator is stopped to stop the feeding and replenishment of the toner, while the developing roller is rotated after a lapse of a predetermined time. From stopping
After that, for example, when the developing device is replaced, it is possible to prevent the toner from adhering to the developing roller from falling or the developing roller from being touched and soiled.

[Brief description of drawings]

FIG. 1 is a block diagram showing a drive system of a developing device in a laser printer which is an embodiment of the present invention.

FIG. 2 is a flowchart at the start of driving the laser printer.

FIG. 3 is a flowchart at the end of driving.

FIG. 4 is an external perspective view of a developing device included in the laser printer.

FIG. 5 is an overall schematic configuration diagram showing an internal mechanism of the laser printer.

FIG. 6 is a block diagram showing a drive system of a developing device in a conventional laser printer.

[Explanation of symbols]

 12 Photoreceptor 14 Developing Device 35 Developing Roller 38 Toner-Replenishing Member 39 Agitator 41 Dedicated Drive Motor 42 Control Unit

Claims (3)

[Claims] 1. A latent image on a photoconductor, comprising a developing roller, a toner replenishing member for replenishing the toner to the developing roller, and an agitator for feeding the toner toward the developing roller. An electrophotographic recording apparatus for developing a toner, comprising an exclusive drive motor for driving the agitator. 2. The electrophotographic recording apparatus according to claim 1, further comprising control means for rotating the developing roller after driving the toner supply member and the agitator at the start of driving. 3. The electrophotographic recording apparatus according to claim 1, further comprising control means for stopping the rotation of the developing roller after stopping the driving of the toner supply member and the agitator at the end of the driving.