JPH05188781A - Image forming device - Google Patents

Abstract

PURPOSE:To confirm quantity of two component developer inside a developing device of the image forming device. CONSTITUTION:In the image forming device provided with latent image forming parts 11 and 12 forming latent images to a latent image forming body 10, a feeding port 37 and an ejection port 38 of the developer, a developing device 3 to develope the latent image on the latent image forming body 10 with the two component developer and a transfer part 13 to transfer a toner image of the latent image forming body 10 to a sheet PP and carrying out feeding and ejecting of the developer to the developing device 3, a measuring means 39 measuring the quantity of the developer inside the developing device 3 is provided.

Description

Detailed Description of the Invention

(Table of Contents) Industrial Application Field of the Invention Prior Art Problems to be Solved by the Invention Means for Solving the Problems (FIG. 1) Action Example (a) Description of the First Example (FIGS. 2 to 4) 6) (b) Description of the second embodiment (FIG. 7) (c) Description of the third embodiment (FIGS. 8 to 11) (d) Description of the fourth embodiment (FIG. 12) (e) Description of other embodiments

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for confirming the amount of developer in a developing device for developing a latent image on a latent image forming body with a two-component developer.

An image forming apparatus for forming a latent image in an electrophotographic apparatus, an electrostatic recording apparatus or the like and developing it with a developer to obtain a visible image is widely used in output devices such as computers, copying machines and facsimiles. Has been done.

In such an image forming apparatus, a developing method using a two-component developer composed of a carrier and a toner is widely used because the toner can be stably charged and can be developed in a non-contact manner with a photosensitive drum.

When this two-component developer is used for a long time, the carrier deteriorates and stable development cannot be maintained. Therefore, the two-component developer in the developing device should be replaced every predetermined number of prints or every operating time. It is necessary to do so, and it is desirable to appropriately replace the developer.

[0006]

2. Description of the Related Art A developer is generally put in a developing device by the manufacturer at the time of shipment of the apparatus, but thereafter, an operator is notified every predetermined number of sheets or every operating time, and service personnel such as the manufacturer replace the developer. However, in recent years, the operator discharges the developer from the developing device and inputs a new developer.

[0007] Such a replacement of the developer has been increased in the amount of input due to the recent high-speed printing, and the replacement cycle has been shortened. For the developer in this developing device, it is necessary to completely discharge the developer at the time of discharge, and to charge a prescribed amount of developer at the time of charging, and the amount charged is the developer bottle containing the new developer. The number of bottles for 2 to 4 bottles was controlled, and the discharge was performed by visually confirming that the developer was exhausted.

[0008]

However, the prior art has the following problems. When the developer is discharged, the developer in the developing device may not be completely discharged, and when a new developer is added, the developer in the developing device becomes excessive and the developer in the developing device becomes too large. Since there is no means to confirm the amount, if it is operated as it is, the driving load of the developing device will be large and it will not be possible to drive it.If the toner concentration is controlled using the magnetic permeability sensor, the toner concentration will deviate from the specified value and become dark , The developer overflows from the developing unit.

Similarly, when the developer is put in the developing device in an amount larger than the specified amount, the same problem as in the above occurs. On the contrary, if the amount of the developer is less than the specified amount in the developing device, the toner density is controlled to be thin and the print quality is deteriorated.

Therefore, an object of the present invention is to provide an image forming apparatus capable of confirming the amount of two-component developer in a developing device.

[0011]

FIG. 1 shows the principle of the present invention. According to claim 1 of the present invention, the latent image forming portions 11 and 12 for forming a latent image on the latent image forming body 10, the developer inlet 37 and the outlet 38 are provided, and the latent image of the latent image forming body 10 is provided. An image that has a developing device 3 for developing the toner with a two-component developer and a transfer portion 13 for transferring the toner image of the latent image forming body 10 onto a sheet PP, and in which the developing device 3 is charged and discharged. The forming apparatus is characterized in that a measuring unit 39 for measuring the amount of the developer in the developing device 3 is provided.

According to claim 2 of the present invention, in claim 1,
It is characterized in that the amount of the developer in the developing device 3 is measured by the measuring means 39 when the developer is put into or discharged from the developing device 3.

According to a third aspect of the present invention, in the first or second aspect, the control unit for notifying the operator when the amount of the developer in the developing device 3 does not satisfy the prescribed amount measured by the measuring means 39. 20 is provided.

According to a fourth aspect of the present invention, in the second or third aspect, the measuring means 39 is a flow rate detecting section for detecting the flow rate of the introduced developer or the flow rate of the discharged developer at the inlet 37 or the outlet 38. It is characterized by having done.

According to a fifth aspect of the present invention, in the fourth aspect,
The flow rate detection unit has a rotating member 39a that rotates by the developer flow, and measures the amount of the developer by the amount of rotation of the rotating member 39a.

According to claim 6 of the present invention, in claim 4
The flow rate detection unit includes a magnetic permeability sensor 39c that detects the magnetic permeability of the developer flow. A seventh aspect of the present invention is characterized in that, in the first, second or third aspect, the measuring unit 39 is configured by a weight measuring unit 39d for measuring the weight of the developing device 3.

According to claim 8 of the present invention, in claim 7,
The weight measuring unit 39d is provided below the developing device 3. A ninth aspect of the present invention is characterized in that, in the eighth aspect, a movable mechanism 26 that allows the developing device 3 to ride on the weight measuring section 39d at the time of measuring the weight is provided.

According to a tenth aspect of the present invention, in the seventh aspect, the weight measuring unit 39d is provided on an upper portion of the apparatus, the developing device 3 is removed, and the weight measuring unit 39d is mounted to measure the weight. It is characterized by

The eleventh aspect of the present invention is the control section for executing the measurement by the measuring means 39 according to the instruction of the operator according to the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, or tenth aspect. 20 is provided.

[0020]

According to the first aspect of the present invention, since the image forming apparatus is provided with the measuring means 39 for measuring the amount of the developer in the developing device 3, the amount of the developer in the developing device 3 can be confirmed. It is possible to eliminate the harmful effects caused by excess and deficiency.

According to the second aspect of the present invention, since the amount of the developer in the developing device 3 is measured by the measuring means 39 when the developer is charged into or discharged from the developing device 3, the developer is not discharged. It is possible to completely eliminate the adverse effects caused by the excessive or excessive developer amount due to the addition of a specified amount or more and the unexpected developer amount due to the addition of the specified amount or less.

According to the third aspect of the present invention, the controller 20 is provided to notify the operator when the amount of the developer in the developing device 3 does not satisfy the specified amount by the measurement of the measuring means 39. It is possible to notify the operator of the excess or deficiency of the amount and take necessary measures in advance.

In the fourth aspect of the present invention, the measuring means 39 is
Since the flow rate detecting unit for detecting the flow rate of the supplied developer or the flow rate of the discharged developer at the charging port 37 or the discharging port 38 is used, the amount of the developer can be automatically measured by the charging operation or the discharging operation of the developer.

According to a fifth aspect of the present invention, the flow rate detecting section has a rotating member 39a which is rotated by the developer flow, and the developer amount is measured by the rotation amount of the rotating member 39a. The amount of developer can be automatically measured with a simple configuration by the charging operation or the discharging operation of.

In the sixth aspect of the present invention, since the flow rate detecting portion has the magnetic permeability sensor 39c for detecting the magnetic permeability of the developer flow, the developer charging operation or the discharging operation can be performed automatically and easily. The amount of developer can be measured with the configuration.

In claim 7 of the present invention, the measuring means 39 is
Since the weight measuring unit 39d for measuring the weight of the developing device 3 is used, the amount of the developer can be measured easily and accurately. According to the eighth aspect of the present invention, since the weight measuring unit 39d is provided below the developing unit 3, the developer amount can be measured by simply removing the developing unit 3, and a general-purpose scale can be used.

According to a ninth aspect of the present invention, the movable mechanism 2 for placing the developing device 3 on the weight measuring section 39d when measuring the weight.
Since 6 is provided, the amount of developer can be measured automatically and with a simple structure without manual labor.

In the tenth aspect of the present invention, the weight measuring unit 39
d is provided on the upper part of the apparatus, the developing device 3 is removed,
Since the weight is measured by riding on the weight measuring unit 39d, it suffices to provide the apparatus with the weight measuring unit 39d, and a general-purpose scale can be used.

In the eleventh aspect of the present invention, the control unit 2 for executing the measurement by the measuring means 39 according to the instruction of the operator.
Since 0 is provided, measurement can be performed only when the operator needs it, and malfunctions when it is unnecessary can be prevented.

[0030]

【Example】

(a) Description of First Embodiment FIG. 2 is an overall configuration diagram of a first embodiment of the present invention, FIG. 3 is an external view of the first embodiment of the present invention, and FIG. 4 is a first embodiment of the present invention. It is a block diagram and shows the example of the electrophotographic printing apparatus.

In FIG. 5, the printing mechanism is composed of an electrophotographic printing mechanism, and a charging device 11, an optical image writing section 12, a developing device 3 and a transfer device 13 are provided around the rotating photosensitive drum 10. It is provided.

The optical image writing section 12 includes a light emitting source (semiconductor laser), a polygon mirror (optical scanner) for optically scanning the light of the light emitting source, and a laser scanning writing including a mirror for guiding the scanning light to the photosensitive drum 10. It is composed of a mechanism.

As shown in FIGS. 2 and 3, the developing unit 3 applies a two-component developer composed of toner and carrier to the photosensitive drum 10.
To the magnetic rollers 35, 36, a supply roller 34 for supplying a two-component developer to the magnetic roller 35, an agitating roller 33 for agitating the carrier and the toner, and a developer inlet 37 for injecting the developer. , And a developer discharge port (screw) 38 for discharging the developer.

Further, the developing device 3 is provided with a toner replenishing part, and a toner containing part (toner cartridge) 31 containing the toner and toner from the toner containing part 31 are developed.
And a replenishment roller 32 for supplying

As is well known, the operation of the electrophotographic printing mechanism is such that the photosensitive drum 10 is uniformly charged by the charger 11, and the light of the light emitting source driven by the video signal is optically scanned by the polygon mirror to cause the optical unit 12 to operate. Line exposure of the photosensitive drum 10 to form an electrostatic latent image, toner development by the developing device 3,
Transfer the paper 1 to the paper PP that is fed leftward in the figure by the transport roller.
At 3, the toner image on the photosensitive drum 10 is transferred, the paper is separated from the photosensitive drum 10, and the separated paper PP is sent to the fixing device and the toner image is fixed.

As shown in FIG. 4A, the developer input port (pipe) 37 and the developer discharge port (pipe) 38 are
A flow sensor 39 is provided on a stainless steel pipe,
The flow rate sensor 39 has an impeller 39a that is rotated by the input / output developer flow, and a guide 39b that guides the developer flow to the impeller 39a.

The characteristic of the flow sensor 39 is shown in FIG.
Shows the relationship between the developer flow rate and the impeller rotation speed as shown in
With one rotation of the impeller 39a, 5 grams of the developer has flowed, and by detecting the rotation speed of the impeller 39a, it is possible to detect the amount of supplied and discharged developer.

FIG. 5 is a block diagram of the first embodiment of the present invention. In the figure, 20 is a main control unit (processor) that controls the entire apparatus, 21 is a ROM that stores operating programs of the processor 20, 22 is an operation panel, and a developer injection instruction , A developer discharge instruction and the like.

Reference numeral 23 is a developing device motor, which gives a driving force to each part of the developing device 3, and 24 is a developing device motor driver, and the developing device motor 23 is instructed by the processor 20.
And a discharging clutch 25 for transmitting / disconnecting the driving force of the developing device motor 23 to the discharging screw 38.

Reference numeral 39 is the above-mentioned flow rate sensor provided at the developer inlet 37 and the developer outlet 38, respectively. This operation will be described. When a developer input instruction is given from the operation panel 22, the processor 20 drives the developing device motor 23 via the driver 24 to operate the developing device 3.

When the operator begins to inject the developer from the developer input port 37, the flow sensor 39 provided in the developer input port 37 detects the rotation of the impeller 39a due to the input of the developer, and the detection signal ( One pulse for one rotation) is sent to the processor 20, and the processor 20 counts the input rotation speed detection signal.

When the developer input instruction is released from the operation panel 22, the processor 20 causes the impeller 49a to rotate at a prescribed developer amount (eg, 7 kg) stored in the ROM 21 (eg, 1400 revolutions). When,
Compare with the counted number of rotations.

Based on this comparison, the processor 20 determines that the amount of developer in the developing device is within an allowable range (for example, 7 kg ± 200).
g), that is, if the counting rotation speed is 1400 ± 40 rotations,
If no problem is displayed on the operation panel 22, and the upper limit of the range (1440 rotations) is exceeded, the amount of developer is large. If the lower limit of the range (1360 rotations) is insufficient,
When the amount of developer is small, it is displayed on the operation panel 22 and an alarm is raised.

On the other hand, in the case of discharging, when the developer discharging instruction is given from the operation panel 22, the processor 20
Connects the discharge clutch 25, drives the developing device motor 23 via the driver 24, operates the developing device 3, and operates the discharging screw 38 to discharge the developer from the inside of the developing device 3.

When the developer starts to be discharged, the developer discharge port 3
The rotation of the impeller 39a due to developer discharge is detected by the flow rate sensor 39 provided in FIG. 8, a detection signal (1 pulse for 1 rotation) is sent to the processor 20, and the processor 20 detects the discharge rotation speed detection signal. Is counted.

When the developer discharge instruction is released from the operation panel 22, the processor 20 causes the processor 20 to rotate the impeller 49a at a prescribed amount of developer stored in the ROM 21 (for example, 6.8 kg) (for example, 1360). rotation)
And the counted number of rotations are compared.

Based on this comparison, the processor 20 determines that the amount of developer in the developing device is within an allowable range (for example, 6.8 kg ± 200).
g), that is, if the counting rotation speed is 1360 ± 40 rotations,
If no problem is displayed on the operation panel 22 and the upper limit of the above range (1400 revolutions) is exceeded, the amount of discharge is large. If the lower limit of the above range (1320 rotations) is insufficient, it is displayed on the operation panel 22 that there is a developer remaining amount,
If an alarm is raised and there is a developer remaining amount, a re-discharge operation is instructed.

Incidentally, the reason why the nominal value of the allowable range is smaller than the value at the time of introducing the developer is that it is considered that the developer has decreased due to carrier rising.
FIG. 6 is an explanatory diagram of the first embodiment of the present invention.

Amorphous silicon is used for the photosensitive drum 10, a magnetite type carrier is used for the carrier, and a polyester type toner is used for the toner.
69 mm / sec, the diameters of the magnetic rollers 35 and 36 were 60 mm, the rotation speed was 200 rpm, the developing gap was 2.2 mm, the potential of the photosensitive drum 10 was 420 V, and the bias voltage was 200 V.

When the amount of developer supplied / discharged was changed and 10,000 sheets were printed and the developer was discharged, the results shown in FIG. 6 were obtained. FIG. 6 shows the presence / absence of an alarm at the time of developer injection, developer discharge for each developer input / discharge amount (o is normal, x is alarm), the driving state of the developing device motor, and the toner concentration.

However, when the alarm was raised when the developer was charged, the evaluation was carried out by resetting as it was, and the toner concentration was controlled by using the magnetic permeability sensor. As a result, when the amount of developer input is 7.2 to 6.8 kg, the above-mentioned allowable range of developer input indicates normal when the developer is input, the driving of the developing device motor is normal, and the toner concentration is also The developer discharge amount is proper from 6.1 to 5.9, and the developer discharge amount is 7.0 to 6.6 kg. In the above-mentioned developer discharge allowable range, the developer discharge is normal, and The drive of the motor was also normal, and the toner density was in the proper range of 6.0 to 5.8.

This means that the alarm is raised before the developing device motor cannot be driven due to the excessive amount of the developer in the developing device 3, and the change in the toner concentration due to the amount of the developer also becomes large. Indicates that the alarm is raised.

That is, the alarm is raised before the amount of the developer which causes trouble in printing is reached. Since the amount of the developer in the developing device 3 is measured in this manner, the adverse effect of the change in the amount of the developer can be prevented.

Further, since the measurement is performed at the time of charging the developer and at the time of discharging the developer, it can be confirmed before the operation. Furthermore, since the measurement result is notified to the operator, it is possible to always print with a stable amount of developer,
Early action on alarms can be taken.

In addition, since the flow rate sensor 39 is used, the measurement can be performed easily and simply, and since a rotating member such as an impeller is used, it can be realized at low cost. (b) Description of Second Embodiment FIG. 7 is an explanatory view of a second embodiment of the present invention.

In this embodiment, in the construction of FIGS. 2, 3 and 5, as shown in FIG.
A magnetic permeability sensor 39c is provided on each of Nos. 7 and 38 to measure the developer flow rate.

That is, the permeability sensor 39c (TS0512LB-X manufactured by TDK) is attached to the stainless steel pipes 37 and 38.
And a two-component developer (magnetite-based carrier, polyester-based toner, toner concentration 5 wt%) was flown, and the result of FIG. 7B was obtained.

From FIG. 7B, the stainless steel pipe 37,
Since the output voltage of the magnetic permeability sensor 39c changes according to the amount of developer flowing through the sensor 38, the amount of developer flowing in the pipe can be accurately grasped by the output voltage of the magnetic permeability sensor 39c and time.

That is, the processor 20 of FIG. 5 takes in the output voltage of the magnetic permeability sensor 39c and can measure the amount of developer input and the amount of developer discharged from the duration, and the same operation as described above can be performed. (c) Description of Third Embodiment FIG. 8 is an overall configuration diagram of the third embodiment of the present invention, and FIG. 9 is a configuration diagram of the third embodiment of the present invention, showing an electrophotographic printing apparatus.

In the figure, the same components as those shown in FIGS. 1 to 7 are designated by the same symbols. In FIG. 8, a pre-charger 11 for pre-charging the photosensitive drum 10 and LE
An image writing unit 12 composed of a D array and a developing device 3 are arranged, and a transfer device 13 for transferring a toner image onto the sheet PP and an optical static eliminator for optically neutralizing the photosensitive drum 10 are provided above the photosensitive drum 10. 14 and a cleaner 15 that removes the residual toner on the photosensitive drum 10.

On the other hand, the developing device 3 includes the toner cartridge 3
1, a replenishing roller 32 for replenishing the toner of the toner cartridge 31, and a stirring roller 33 for stirring the two-component developer.
A supply roller 34 for supplying the two-component developer, a developing roller 35 for supplying the two-component developer to the photosensitive drum 10,
A toner concentration sensor (permeability sensor) TS for detecting the toner concentration of the two-component developer is provided, and the developer input port 3 is provided on the upper portion.
7 and a developer discharge port 38 on the lower surface. The developer inlet 37 is provided at the same position as in the first embodiment shown in FIG.

In FIG. 9, below the developing unit 3, a weight detecting section 39d composed of an electronic scale is provided.
Blocks 30 having holes 30a are provided on both sides of the block 30, and a support shaft 26a is provided to oppose the block 30.

Therefore, at the time of printing, as shown in FIG. 9 (A), the support shaft 26a enters the hole 30a of the block 30 to hold the developing device 3 at the developing position, and at the time of weight detection, FIG. 9 (B). As shown in, the support shaft 26a is disengaged from the hole 30a of the block 30, and the developing device 3 rides on the weight detecting portion 39d, whereby the weight of the developing device 3 is detected.

FIGS. 10 and 11 are explanatory views (No. 1) and (No. 2) of the third embodiment of the present invention, and control is performed by the configuration of FIG. At the time of printing, as shown in FIG. 10A, the rack 2 is inserted into the hole 30 a of the block 30 of the developing device 3.
The support shaft 26a driven by 6b enters, is held at the developing position, and is separated from the weight detection unit 39d.

When the developer is charged, the operator opens the developer charging port 37 to charge the developer, and when the developer is discharged, the operator opens the developer discharging port 38 and discharges the developer by its own weight. It shall be.

When the operator completes the loading / unloading of the developer, the operator instructs the completion of the loading / unloading of the developer from the operation panel 22, and the processor 20 drives the motor of the movable mechanism 26 to drive the rack 26b.
When 6c is rotated as shown in FIG. 10B, the pointed support shaft 26a causes the hole 30 of the block 30 of the developing device 3 to move.
The developing device 3 descends from a, and rides on the weight detecting portion 39d as shown in FIG. 10 (C).

As a result, the weight detector 39d measures the weight of the developing device 3 and notifies the processor 20 of the weight. The processor 20 stores the prescribed weight (for example, the developing device) stored in the ROM 21 when the developer is charged. If the unit weight is 6.3 kg and the developer amount is 2.7 kg, then 9.0 kg) is compared with the measured weight.

According to this comparison, the processor 20 displays on the operation panel 22 that there is no problem if the measured weight of the developing device is within the allowable range (for example, 9 kg ± 200 g), and sets the upper limit of the range (9.2 kg). If it exceeds, the amount of developer is large, and if the lower limit of the above range (8.8 kg) is not enough, if the amount of developer is small, it is displayed on the operation panel 22 and an alarm is raised.

When such weight measurement is completed, the processor 20 reversely drives the motor of the movable mechanism 26 and sets the pinion gear 26c for driving the rack 26b to the position shown in FIG.
As shown in FIG. 11, when it rotates, the pointed support shaft 26a enters the hole 30a of the block 30 of the developing device 3, the developing device 3 moves up, and as shown in FIG.
It leaves 9d and returns to the developing position.

Similarly, at the time of discharging, the specified weight may be set to 6.3 kg and the allowable range may be set to (6.3 kg ± 200 g). In this way, the amount of the developer in the developing device 3 can be measured by measuring the weight of the developing device 3, and accurate measurement can be performed, and a general-purpose scale can be used.

Further, since the movable mechanism 26 automatically moves to the developing position and the measuring position to measure and restore the weight, the weight can be automatically measured. (d) Description of Fourth Embodiment FIG. 12 is an explanatory view of the fourth embodiment of the present invention.

In the figure, reference numeral 1 is a printer engine section, which has the configuration shown in FIG. 2, and 2 is a hopper section which accommodates sheets to be printed and which is fed to the printer engine section 1.
Reference numeral 4 denotes a stacker unit for storing sheets printed by the printer engine unit 1, 39 denotes an electronic balance,
It is provided above the hopper unit 2.

In this embodiment, the developing unit 3 of the printer engine unit 1 shown in FIG. 2 is constructed so that it can be taken out.
The electronic balance 39 that is installed in the hopper unit 2 after being detached from the
Measure the weight with.

After the developer is charged, the weight of the developing device 3 is
If it is 9 ± 0.2 kg (developing unit weight is 6.3 kg, developer amount is 2.7 kg), if the developer is discharged, the developing unit 3
If the weight is 2.9 ± 0.2 kg, there is no problem.

In the range other than this, the amount of the developer is not appropriate, and for example, after discharging, it is found that a predetermined amount or more of the developer remains in the developing device 3, and the trouble is prevented beforehand. it can.

The toner hopper having the toner cartridge 31 and the replenishing roller 32 is detachable from the developing device 3 and is detached when the weight of the developing device 3 is measured.

As described above, the amount of the developer in the developing device 3 can be measured by measuring the weight of the developing device 3, and accurate measurement can be performed. Also, a general-purpose scale can be used and only the hopper portion 2 can be used. Can be achieved with.

Further, the measured weight may be notified to the processor 20 of FIG. 5 and the determination result may be displayed on the operation panel 22. (e) Description of Other Embodiments In addition to the above embodiments, the present invention can be modified as follows.

Although the image forming apparatus has been described as an electrophotographic printing apparatus, it can be applied to an apparatus such as an electrostatic recording apparatus that forms and develops an electrostatic latent image. Although the printer has been described, it can be applied to an image forming apparatus such as a copying machine or a facsimile.

In the first, second and third embodiments, the measurement results may be displayed on the operation panel 22. Although the flow rate sensor and the weight sensor have been described as the measuring means,
This can be applied as long as the amount of developer in another developing device can be measured.

Although the measurement is performed both at the time of charging the developer and at the time of discharging the developer, it may be measured at either the charging time or the discharging time, if necessary. Although the present invention has been described with reference to the embodiments, various modifications are possible within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

[0082]

As described above, according to the present invention,
It has the following effects. Since the image forming apparatus is provided with the measuring means for measuring the amount of the developer in the developing device, due to insufficient discharge of the developer, an excessive amount of developer occurs at the time of introducing the next developer, driving failure of the developing device, toner concentration fluctuation, It is possible to prevent the developer from overflowing.

Since the old developer remains due to the introduction of the next developer due to insufficient discharge of the developer, it is possible to prevent the new developer from being adversely affected and the development failure. It is possible to prevent excess and deficiency of the developer amount when the developer is charged,
Drive failure of the developing device due to excessive developer, toner concentration fluctuation,
It is possible to prevent overflow of developer and fluctuation of toner concentration due to lack of developer, especially in high-speed machines,
The effect is great when applied to a developer with a large amount of developer and a short replacement period.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is an overall configuration diagram of a first embodiment of the present invention.

FIG. 3 is an external view of the first embodiment of the present invention.

FIG. 4 is a configuration diagram of a first embodiment of the present invention.

FIG. 5 is a block diagram of a first embodiment of the present invention.

FIG. 6 is an explanatory diagram of the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of a second embodiment of the present invention.

FIG. 8 is an overall configuration diagram of a third embodiment of the present invention.

FIG. 9 is a configuration diagram of a third embodiment of the present invention.

FIG. 10 is an explanatory view (No. 1) of the third embodiment of the present invention.

FIG. 11 is an explanatory view (No. 2) of the third embodiment of the present invention.

FIG. 12 is an explanatory diagram of the fourth embodiment of the present invention.

[Explanation of symbols]

 1 Printer Engine Section (Electrophotographic Printing Mechanism) 2 Hopper Section 3 Developing Device 4 Stacker Section 10 Latent Image Forming Body (Photosensitive Drum) 11 Pre-Charging Unit 12 Optical Image Writing Section 13 Transfer Unit 20 Control Section (Processor) 26 Moving Mechanism 30 Block 37 Developer inlet (developer pipe) 38 Developer outlet (developer pipe) 39 Measuring means 39a Impeller 39c Permeability sensor 39d Electronic scale

Front page continuation (72) Inventor Ryo Koshi 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (11)

[Claims] 1. A latent image forming section (11, 12) for forming a latent image on a latent image forming body (10), a developer inlet (37) and a developer outlet (38). It has a developing device (3) for developing the latent image of the body (10) with a two-component developer, and a transfer part (13) for transferring the toner image of the latent image forming body (10) onto a sheet (PP). In an image forming apparatus for feeding and discharging a developer in the developing device (3), a measuring means (3) for measuring the amount of the developer in the developing device (3).
9) is provided, an image forming apparatus. 2. The amount of developer in the developing device (3) is measured by the measuring means (39) when the developer is put into or discharged from the developing device (3). The image forming apparatus according to item 1. 3. A control unit (20) for notifying an operator when the amount of developer in the developing device (3) does not satisfy a prescribed amount by the measurement of the measuring means (39). The image forming apparatus according to claim 1 or 2. 4. A flow rate detecting unit for detecting the flow rate of the supplied developer or the flow rate of the discharged developer at the charging port (37) or the discharging port (38). The image forming apparatus according to item 2 or 3. 5. The flow rate detecting section includes a rotating member (39a) which is rotated by the developer flow, and the rotating member (39).
The image forming apparatus according to claim 4, wherein the developer amount is measured by the rotation amount of a). 6. The image forming apparatus according to claim 4, wherein the flow rate detecting unit includes a magnetic permeability sensor (39c) for detecting magnetic permeability of the developer flow. 7. The image forming apparatus according to claim 1, 2 or 3, wherein the measuring means (39) is composed of a weight measuring section (39d) for measuring the weight of the developing device (3). 8. The image forming apparatus according to claim 7, wherein the weight measuring unit (39d) is provided below the developing device (3). 9. The image forming apparatus according to claim 8, further comprising a movable mechanism (26) which allows the developing device (3) to ride on the weight measuring section (39d) when measuring the weight. 10. The weight measuring unit (39d) is provided on the upper part of the apparatus, the developing unit (3) is removed, and the weight measuring unit (39d) is mounted to measure the weight. The image forming apparatus according to claim 7. 11. The measurement by the measuring means (39)
A control unit (20) for executing the instruction according to an operator is provided.
Or 6 or 7 or 8 or 9 or 10.