JPH063945A - Developer discharging mechanism for developing device - Google Patents

Abstract

PURPOSE:To reduce the starting torque of the whole and to decrease the capacity of a motor by making the driving start time of a discharging roller earlier than that of a developing roller, etc., at the time of discharging developer. CONSTITUTION:A discharging roller driving part 71 driving the discharging roller 14 is constituted of a main motor 43, gears 63 and 64, and an electromagnetic clutch 65, etc. A developer discharging control means 72 is provided with a discharging roller control means 73 for instantenously driving the roller 14 at the time of discharging the developer, and a developing roller control means 74 for delaying the start of driving a developing roller 4 by specified time at the time of discharging the developer. Then, the means 72 controls a developing roller driving part 70 and the discharging roller driving part 71 so that the roller 14 may be driven earlier than the start of driving the roller 4 at the time of discharging the developer. Thus, the starting torque at the time of starting the discharge is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer discharging mechanism for discharging a developer in a developing device in an electrophotographic image forming mechanism.

[0002]

2. Description of the Related Art A conventional developing device is provided with a developing device main body, a developing roller, a stirring roller, and an agitator, and these rollers are simultaneously driven by a developing roller driving section. A discharge roller for discharging the developer is provided, and a discharge roller drive unit for driving the discharge roller and a drive motor used by both drive units are provided.

When the developer is discharged, the developing roller,
The stirring roller, agitator, and discharge roller were simultaneously activated.

[0004]

However, since the discharge roller is not driven during copying, the torque for driving the discharge roller is increased only when the developer is discharged, and thus the drive motor is driven. It was necessary to increase the capacity.

In view of the above, an object of the present invention is to provide a developer discharging mechanism capable of reducing the starting torque at the time of discharging the developer and reducing the capacity of the drive motor.

[0006]

As shown in FIGS. 1 and 2, a means for solving the problems according to the present invention is a discharging roller 1 when discharging a developer.
There is provided a developer discharge control means 72 for controlling the developing roller drive unit and the discharge roller drive unit so that the start-up of the developing roller 4 is started earlier than the start-up of the developing roller 4.

This developing device can be applied not only to the developing device having the drive motor 43 for driving only the developing roller, but also to the developing device for driving the agitating roller 5 and the agitator 8a by the developing roller driving section.

[0008]

In the above means for solving the problems, when the developer is discharged,
Since the discharge roller 14 is started earlier than the start of the developing roller 4, the start torque at the start of discharge can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a timing chart of the developer discharging mechanism of a developing device according to an embodiment of the present invention at the time of starting discharge of developer from a discharging roller and a developing roller, and FIG. 3 is a plan view, FIG. 3 is a side view showing a drive gear transmission mechanism such as a developing roller, FIG. 4 is a side view showing a drive transmission mechanism such as a developing roller, and FIG. 5 is a drive unit for a toner replenishing roller and a toner conveying screw. FIG. 6 is a front view, FIG. 6 is a cross-sectional view showing the configuration of the developing device, and FIG. 7 is a configuration diagram showing the arrangement of discharge rollers and the like of the developing device.

First, the schematic structure of the developing device shown in FIGS. 6 and 7 will be described. In this developing device, a developing tank 2 is arranged so as to face the photoconductor 1, and a toner replenishing tank 3 is provided above the developing tank 2. It is installed. In the developing tank 2, a developing roller 4 and a stirring roller 5 are rotatably incorporated. Toner supply tank 3
A toner replenishing roller 6 and a pair of toner conveying screws 7 are rotatably mounted inside.

The developing tank 2 and the toner replenishing tank 3 are communicated with each other via a toner replenishing opening 2a.
The conveying screw 8 is rotatably arranged below a.

One side of the conveying screw 8 is installed in a carrying-in cylinder 9 projecting from the developing tank 2, a developer supply port 10 is formed in the carrying cylinder 9, and a pipe 11 is connected to the developer supply port 10. A developer supply tank 12 is connected.

The other side of the conveying screw 8 is an agitator 8a, and a U-shaped conveying path 13 is arranged around the conveying screw 8. The conveyance path 13 has an opening 13a directed upward, and the opening 13a is enlarged from one side to the other side.

A screw-shaped developer discharging roller 14 is rotatably arranged in the recess of the bottom of the developing tank 2, and the discharging roller 14 has a discharge tube 15 whose one side projects from the developing tank 2.
It is decorated in. The carry-out cylinder 15 has a developer discharge port 16
Is formed, and the discharge port 16 is connected to a recovery container 18 via a pipe 17.

An opening / closing shutter 19 is provided at the discharge port 16 and is controlled so that the discharge port 16 is closed at the time of development and opened when the developer is discharged.

In FIG. 6, 20 is a doctor, 21 is a sink plate, and 22 is a toner density sensor.

In such a developing device, during development,
The stirring roller 5 and the agitator 8a are rotated to stir the developer in the entire developing tank, and the developer is supplied to the developing roller 4.

Since the developer deteriorates and reaches the end of its life with the use of the developer, the developer must be replaced. Therefore, by opening the shutter 19 and rotating the discharge roller 14, the developer in the developing tank 2 drops from the discharge port 16 and is stored in the recovery container 18. Then, the new developer D is supplied to the developing tank 2 by using the carrying screw 8.

Next, the drive units such as the rollers will be described with reference to FIGS. FIG. 3 is a view taken in the direction of the arrow Q in FIG. 7, showing the arrangement of the drive gears of the rollers. 21 is a drive gear for the developing roller 4, 22 and 23 are two-stage idle gears,
Reference numeral 24 is a drive gear of the stirring roller 5, and 25 is a drive gear of the agitator. The connection of these gears is 21 → 22,23
→ 24 → 25. When the gear 21 for the developing roller is driven, the rollers 5 and 8a are also driven at the same time. However, only the discharge roller 14 is separately driven, and the spring pin 27 press-fitted into the shaft 26 described later is driven by the coupling 28.

2 and 4 are a plan view and a layout view of the developing drive system of the machine body. Reference numeral 31 is a drive coupling for driving the drive gear 21 attached to the tip of the developing roller 4. The coupling 31 is fixed to a shaft 32, and the shaft 32 is the drive frame 3
It is rotatably supported between bearings 3 and 34 via a bearing 36. The frame 34 is fixed to the drive frame 37. Reference numeral 38 is a shaft through hole formed in the frame 37. In addition to the pulley 4
1 and gear 42 are attached.

On the other hand, the drive frames 34 and 37 have a shaft 43 for the toner replenishing roller 6, a shaft 49 for the toner conveying screw 7, and these shafts 43, 4.
Transmission shafts 45 and 46 for transmitting power to the motor 9 are rotatably supported.

A coupling 47 for connecting with the roller 6 is attached to the tip of the shaft 43 for the toner replenishing roller 6, and a pulley 48 is fixed to the center.

Similarly, a coupling 50 for connecting with the screw 7 is attached to the tip of the shaft 49 for the toner carrying screw 7, and a pulley 51 is fixed in the center.

Further, the power from the developing roller shaft 32 is transmitted to the shaft 45 arranged between the developing roller shaft 32 and the toner carrying screw shaft 49 via the belt 52. A pulley 53 for transmitting the power of the shaft 45 to the shaft 49 for the toner carrying screw, and a spring clutch 56 interposed between the pulleys 53, 54 are provided.

Further, on the shaft 46 arranged between the shaft 49 for the toner conveying screw and the shaft 43 for the toner replenishing roller, a pulley 58 for transmitting the power from the developing roller side via the belt 57, A pulley 59 for transmitting power via a belt 60 and a spring clutch 61 interposed therebetween are provided on the toner supply roller shaft 43.

Furthermore, the shaft 26 of the discharge roller 14 is rotatably supported by the drive frames 34 and 37, and the coupling 28 is provided at the tip of the shaft 26. A transmission gear 63 that is movable in the axial direction is provided on the shaft 26, and a drive gear 64 that transmits the power from the main motor 43 is engaged with the gear 63. The transmission gear 63 is the O clutch of the electromagnetic clutch 65.
The power from the drive gear 64 is transmitted to the shaft 26 by N / OFF.

The output shaft of the main motor 43 is 2
There is a system, one of which is connected to the developing drive gear 44 via a spring clutch 66. The other is connected to an electromagnetic clutch 65 via a gear 64.

A solenoid 67 has a claw 68 at its tip.
Is attached, and ON / OFF switching of the drive of the drive gear 44 is performed by ON / OFF of the solenoid 67. That is, the developing roller driving unit 70 that drives the developing roller 4 includes the main motor 43 and the spring clutch 6.
6, a solenoid 67, a claw 68, a gear 44 and the like.

The discharge roller driving section 71 for driving the discharge roller 14 includes a main motor 43 and gears 63 and 64.
And an electromagnetic clutch 65 and the like.

Then, at the time of discharging the developer, the discharging roller 14
A developer discharge control means 72 is provided for controlling the developing roller drive section 70 and the discharge roller drive section 71 so that the start of the developing roller is started earlier than the start of the start of the developing roller 4.

The developer discharge control means 72 is composed of a general microcomputer, and when the developer is discharged,
Ejection roller control means 73 that immediately activates the ejection roller 14 and development roller control means 74 that delays the activation start of the development roller 4 when the developer is ejected by the time t are provided.

Next, the drive units for the toner replenishing roller 6 and the toner conveying screw 7 shown in FIG. 5 will be described.
In FIG. 5, the spring clutch 5 for the conveying screw
Reference numeral 6 includes a sleeve 56a and a clutch spring 56b inside thereof. This sleeve 56a has claws 56c
Is provided, a movable plate 80 that can be engaged and disengaged with the claw 56c, a solenoid 81 that swings the movable plate 80 around a fulcrum P, and a spring 82 that urges the movable plate in the claw engaging direction.
It has and.

Similarly, the toner replenishing spring clutch 61 comprises a sleeve 61a and a clutch spring 61b inside thereof. The sleeve 61a has a claw 61
c is provided, and the movable plate 83 that can be engaged with and disengaged from the claw 61c,
A solenoid 84 for swinging the movable plate 83 around the fulcrum P and a spring 85 for biasing the movable plate 83 in the claw engaging direction are provided.

FIG. 1 shows the driving timings of the rollers 4, 5, 8 and 14 when the developer is discharged in the above structure. At the time of discharging the developer, the discharging roller 14 is started earlier than each roller for time t seconds, a certain amount of the developer is discharged, and then each roller is started. Then, the developer pressure F applied at startup can be reduced, and the total startup torque can be reduced.

That is, the solenoid 67 is turned on during copying.
Then, the pawl 68 is released from the spring clutch 66. Then, the power from the main motor 43 is transmitted to the gears 44,
42 is transmitted to the developing roller 4, the stirring roller 5 and the agitator 8a rotate, and development is performed. At this time,
The electromagnetic clutch 65 is turned off (stopped) in order to prevent the discharge roller 14 from being driven.

When the developer is discharged, the solenoid 67 is turned off (stopped) for t seconds from the start, and the claw 68 is locked. Then, the spring clutch 66 is stopped and the power is not transmitted to the developing roller 4. Simultaneously with this activation, the electromagnetic clutch 65 is turned on (driven). Then, the driving force from the main motor 43 is transmitted to the discharge roller 14 via the gears 64 and 63, and the discharge roller 14 is driven first. After t seconds, the solenoid 67 is also turned on,
The developing roller 4 is driven.

The method of driving the toner conveying screw 7 and the toner replenishing roller 6 is as follows. The driving of the conveying screw 7 and the replenishing roller 6 is switched by the toner conveying control means 88 and the toner replenishment control means 89 by turning ON / OFF the solenoids 81 and 84.
The solenoids 81 and 84 are turned on and off when the movable plate 80,
83 is moved in the direction of arrow AA 'against the springs 82 and 85 to connect and disconnect the spring clutches 56 and 61.

When the toner is not replenished, as shown in FIG. 5, the solenoid 81 is in the OFF state, and only the pulley 53 is driven to idle.

When toner is supplied, the solenoid 81,
84 is in the ON state, and the movable plates 80 and 83 are claws 56c.
To move away from the pulley 53, the sleeves 56a and 61a rotate, the clutch springs 56 and 61 are connected, and the pulley 53
Is transmitted through the pulleys 54, 51, 58 and 48 to rotate the roller 6 and the screw 7.

The solenoids 81 and 84 have operation modes associated with each other and are as follows. That is, in the case of no toner replenishment and no conveyance, the toner conveyance solenoid 81 and the toner replenishment solenoid 84 are both OF
It is F.

When toner is supplied without toner supply, the toner transfer solenoid 81 is turned on and the toner supply solenoid 84 is turned off.

When toner is supplied and toner is conveyed,
The toner carrying solenoid 81 is turned on and the toner replenishing solenoid 84 is turned on.

Here, the toner feeding means the feeding screw 7
Is rotated to fill the replenishment tank 3 with an appropriate amount of toner. Toner replenishment is to rotate the replenishing roller 6 and the conveying screw 7 to drop the toner into the developing tank.

The present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention.

[0045]

As is apparent from the above description, according to the first and second aspects of the present invention, when the developer is discharged, the driving start timing of the discharging roller is set earlier than that of the developing roller and the like, so that the entire starting torque is increased. Therefore, the capacity of the motor can be reduced.

[Brief description of drawings]

FIG. 1 is a timing chart at the time of starting developer discharge of a discharge roller and a developing roller in a developer discharging mechanism of a developing device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a driving unit of the developing device.

FIG. 3 is a side view showing a transmission mechanism of a drive gear such as a developing roller.

FIG. 4 is a side view showing a drive transmission mechanism such as a developing roller.

FIG. 5 is a front view showing a driving unit of a toner replenishing roller and a toner conveying screw.

FIG. 6 is a cross-sectional view showing the configuration of the developing device.

FIG. 7 is a configuration diagram showing an arrangement of discharge rollers and the like of the developing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 photoconductor 2 developing tank 3 toner replenishing tank 4 developing roller 5 stirring roller 6 toner replenishing roller 7 toner conveying screw 8 conveying screw 8a agitator 14 developer discharging roller 21-25 gear 43 main motor 70 developing roller driving unit 71 discharging roller driving Part 72 Developer discharge control means 73 Discharge roller control means 74 Development roller control means

Claims (2)

[Claims] 1. A developing device in which a developing roller and a discharging roller are provided in a developing device main body, a developing roller driving unit driving the developing roller, a discharging roller driving unit driving the discharging roller, and both driving units. And a drive motor which is also used by the developer discharge control means for controlling the developing roller drive section and the discharge roller drive section so that the discharge roller is started earlier than the start of the developing roller when the developer is discharged. A developer discharging mechanism characterized by being provided. 2. A discharge device for discharging a developer in a developing device, wherein the developing device main body is provided with a developing roller, a stirring roller, and an agitator, and these rollers are simultaneously driven by a developing roller driving section. A developing roller drive unit that is provided with a roller and drives the developing roller, an ejection roller drive unit that drives the ejection roller, and a drive motor that both drive units share are used. A developer discharging mechanism, characterized in that a developer discharging control means for controlling the developing roller driving part and the discharging roller driving part is provided so as to be carried out earlier than the start of activation of the roller.