JPH1115249A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely replenish a developing device with toner according to the shortage of the toner by storing the driving time of a toner replenishing device in a storage means according to consumed toner quantity and driving the toner replenishing device for a time equivalent to the stored replenishing time. SOLUTION: A non-volatile memory ME is incorporated in a controller C. A toner concentration value detected by a toner concentration detection member S is inputted to the controller C through an input-output part C3. By the controller C, the shortage of the toner in the developing device 17 is judged and the actuating time of the toner replenishing device 176 is decided. Besides, the driving time is inputted to the memory ME and stored in it. Then, the developing device 17 is replenished with the toner by driving the rotation of the toner replenishing member 176 for a time equivalent to the actuating time inputted and stored to/in the memory ME by a driving source M1. The driving time that the replenishing member 176 is rotated is subtracted from the driving time stored in the memory ME.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner supply device for replenishing toner in a developing device provided in an image forming apparatus in accordance with the amount of toner consumed by a toner replenishing device when the toner is consumed by image formation. The present invention relates to a toner replenishment control unit described above.

[0002]

2. Description of the Related Art Hitherto, as an image forming apparatus, a copying apparatus, a printer and the like (hereinafter referred to as a copying apparatus) have been provided. As an image forming method, a toner image is formed on an image carrier by forming an electrostatic latent image on an image carrier and developing the electrostatic latent image with a developer containing a toner and a carrier of a developing device.

Next, sheets of various sizes are selected, the selected sheets (hereinafter referred to as recording paper) are fed, and the toner image on the image carrier is transferred using a transfer device. The sheet is conveyed to a heat fixing device, and the toner image is fixed on the recording paper.

In recent years, recording paper for forming images has been stored in cassettes of different sizes according to the size of the original document, and the image is formed on the recording paper. Image formation is also performed by a doubling mechanism.

In a copying apparatus, a start button for image formation is pressed, and at the same time as the start of image formation, an image carrier, a developing device, a paper feeding device, and a transport device (including a heat fixing device) are operated. The toner image formed on the image carrier is transferred to recording paper fed from a paper feeding device, and the developing device, the image carrier, and the transport device are driven by a driving unit until the recording paper is discharged from the transport device. Running continuously.

As described above, if the image carrier and the developing device are also operated continuously during the operation of the copying machine, the deterioration of the photosensitive member is accelerated by cleaning or the like abutting on the image carrier, and the photoconductor is further housed in the developing device. Since the stirring action is performed even when the developer (toner and carrier) does not form an image on the image carrier, the deterioration of the developer (especially the carrier) is accelerated. It must be made.

Therefore, in order to improve the above-mentioned drawback, a period during which an electrostatic latent image is formed on an image carrier to form a toner image,
The image carrier and the developing device (especially the carrier) are configured to be deactivated by stopping the image carrier and the developing device during a period other than the period in which the toner image is transferred to the recording paper. Since the body and the developing device are driven only during image formation and transfer, the driving time of the developing device is also reduced.

Further, a driving means for driving only the developing device is separately provided, and the driving time of the developing device can be shortened by driving the driving means of the developing device only when developing the image carrier.

[0009]

By the way, in the copying apparatus, the toner in the developing device is consumed every time an image is formed on the image carrier by the toner. However, the toner density is detected by the toner density detecting member. Thus, a shortage of consumed toner is replenished to the developer.

In general, a device for replenishing toner to a developing device is a mechanism in which a toner replenishing member is rotated from a toner supply device containing toner and toner is replenished in accordance with the rotation. When a large amount of toner is consumed and the amount of toner shortage increases, it is necessary to extend the toner supply time by the toner supply member. In such a case, since the driving time of the developing device is shortened as described above, the developing device may be stopped during toner supply.

If toner is supplied while the developing device is stopped,
Toner accumulates near the toner supply port of the toner supply device,
There is a case where the toner is clogged in the toner supply member of the toner supply device.

Further, the accumulated toner is difficult to mix with the developer when the next developing device is driven, so that normal stirring is not performed, the charge amount of the toner is reduced, and image fogging and toner scattering occur. Is easy to occur. Further, if only the toner replenishing device is operated while the copying machine is stopped, the toner replenishment sound may be illusioned as a failure.

Therefore, if toner is supplied only during the operation of the developing device, the developing device may stop during the replenishment, and it becomes necessary to perform the toner supplying operation during the next copy sequence. .

In a copying apparatus which is not frequently used, the main switch may be turned on only at the time of copying, and may be turned off when the copying is completed. In this case, the toner supply information that has not been reached in the previous copy is erased in the next copy because the main switch is turned off.

In this case, the toner replenishing device does not operate even though the toner is insufficient in the developer, and the toner replenishment is started by the toner density detecting member until the toner density is detected in the next copying operation. In other words, the toner may run short in the developing device.

Next, various types of recording paper sizes are used.
By detecting the document size at the exposure position of the document and providing multiple cassettes with various types of recording paper sizes corresponding to the detected size information, the recording paper of each size is fed according to the document size and recorded. 2. Description of the Related Art A copying apparatus that forms an image on paper or forms an enlarged or reduced image on a recording paper with respect to a document size by a scaling mechanism is often used.

When recording papers having such various sizes are used, for example, when a large number of large A3 size recording papers are used and when a large number of small B5 size recording papers are used, The amount of toner used is significantly different.
For example, a large amount of toner is used in large A3 size,
When the toner becomes insufficient and the image becomes unclear, or when a small B5 size recording paper is used, if the same amount of toner is replenished as the A3 size, the toner becomes excessive and a good image is obtained. Not only cannot be performed, but also causes toner scattering.

FIGS. 4A and 4B are explanatory diagrams showing image size information.

As shown in FIG. 4A, a case where a reduced image (reduction magnification: 71%) is formed on an A4R size recording paper of a longitudinal feed for an A3 size original by the magnification changing mechanism, As shown in FIG. 4B, in the case where a reduced image (reduction magnification 50%) is formed on a horizontally fed A4 size recording sheet, the former is the case where the image size is formed in A4 full size, In the latter case, the image size is half that of A4 size recording paper, and the amount of toner used is different.

The present invention has been specifically conceived to remedy the above disadvantages. That is, the most appropriate amount of toner for image formation is supplied to the developing device provided in the image forming apparatus,
The purpose is to obtain a good image.

[0021]

According to the present invention, there is provided a developing method for developing an electrostatic latent image formed on an image carrier with a developer comprising a mixture of a toner and a carrier. An image forming cartridge having at least the image carrier and the developing device; a driving unit provided at least separately from the image forming device for driving the developing device; and supplying toner to the developing device. An image forming apparatus having a toner replenishing device for detecting the toner density of the developer and a toner density detecting unit for detecting the toner density of the developer. Storage means for storing the driving time of the replenishing device; and the toner replenishing device according to the driving time stored in the storing means only when the developing device is being driven by the driving means. It is controlled by the control means so as to drive the.

In a preferred embodiment, the storage means is a nonvolatile memory.

According to a third aspect of the present invention, the non-volatile memory accumulates and stores the toner supply time every time the toner concentration is detected by the toner concentration detecting means, and stores the driving time during which the toner supply device is driven. The control means controls the toner replenishing device to stop when the subtracted and stored driving time becomes zero.

According to a fourth aspect of the present invention, there is provided a developing device for developing an electrostatic latent image formed on an image carrier with a developer composed of a mixture of a toner and a carrier, and at least driving the developing device to form an image. A driving unit provided separately from the apparatus, a toner replenishing device for replenishing toner to the developing device, a toner density detecting unit for detecting a toner density value of the developer, and an image formed on the image carrier. Select the sheet to be fed from multiple size sheets to transfer,
In an image forming apparatus having a sheet feeding device for feeding a selected sheet, a toner density value detected by the toner density detecting means, selected sheet size information,
This is achieved by providing a control unit that controls a replenishment time for replenishing toner from the toner replenishing device to the developing device in accordance with image size information formed on the sheet.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 An example of a specific example of the present invention will be described below as an embodiment, but the present invention is not limited to these.

As an example of the present embodiment, the image forming apparatus 2
The configuration of the drum cartridge 100 which is an image forming cartridge having the photosensitive drum 10 and the developing device 17 provided in the image forming apparatus 00 and the operation of the image forming apparatus 200 will be described.

In FIG. 1, reference numeral 11 denotes a corona charging device.
A plurality of scorotron electrodes 13 are provided to perform a charging operation for applying a charge to the surface of the photosensitive drum 10 from the electrode 12 and to perform discharge control in a discharge direction. Prior to the charging operation by the corona charging device 11, a PCL (pre-charging static eliminator) 15 for eliminating charges using a light emitting diode or the like to eliminate the history of the photosensitive drum 10 up to the previous print, and CEL
(Unnecessary charge elimination) 151, a developing device 17, and a cleaning device 27 are sequentially arranged according to the rotation direction of the photosensitive drum 10, and are provided in the drum cartridge 100.

The drum cartridge 100 is provided separately and independently of a main body driving source (not shown) for driving a driven member such as a recording paper conveying member, a fixing device, and a paper feeding device in the image forming apparatus 200. Photoreceptor drums 1 provided inside
0 and a driving source M for driving the developing device 17 are provided. The drive source M is connected to the control device C via the input / output unit C1, and the photosensitive drum 10 in the drum cartridge 100 is
Are connected to the developing device 17 so as to be driven and rotated.

Next, in order to form an image on the photosensitive drum 10, the original 1 provided on a part of the image forming apparatus 200 and placed on an original table formed of a glass plate (not shown) or the like.
6, a reflecting mirror 163 arranged in a V-shape that moves in parallel with the document surface together with a reflecting mirror 162 that receives the exposure light, and moves by half the moving distance of the reflecting mirror 162; The image of the document 16 is exposed on the photosensitive drum 10 charged by the corona charging device 11 by a lens 164 and a reflection mirror 165 that projects an image on the photosensitive drum 10.

The magnification changing means 400 for operating the reflection mirror 162, the lens 164, and the reflection mirror 165 is connected to the control device C via the input / output unit C4.
By inputting a variable power to 0, the reflection mirror 16
2. The lens 164 and the reflection mirror 165 are driven according to the magnification.

A reflection mirror 162 is provided below the original 16.
The document size detection member S4 is provided at a position where the movement of the reflection mirror 163 arranged in the V shape is not hindered. The document size detecting member S4 is connected to the control device C via the input / output unit C4.

As an exposure method, an electrostatic latent image may be formed by image exposure means based on an image signal.

The non-image area after charging, for example, unnecessary charges when the image is reduced is removed from the surface of the photosensitive drum 10 by using the CEL 151.

Next, the electrostatic latent image formed on the surface of the photosensitive drum 10 is developed by a developing roller 171 in a developing device 17 in which a two-component developer composed of toner and carrier is incorporated. Thus, a visible image is formed on the photosensitive drum 10 by the toner.

The developing device 17 is provided with a toner replenishing device 175 for replenishing the toner T.
Replenishing member 1 for sequentially supplying toner to the developing device 17
Reference numeral 76 is provided in the toner supply device 175.

Further, a drive source M1 connected to the control device C via the input / output unit C2 is provided, and the drive source M1 is connected to the toner supply member 176. At the lower position of the toner replenishing member 176, developer conveying screw members 173 and 174 that rotate to both sides via a partition portion 177 are provided in the developing device 17, and the developer conveying screw members 173 are provided.
A toner density detecting member S connected to the control device C via the input / output unit C3 is provided to face the printer.

The developer main stirring member 172 is provided in the developing device 17 and is connected to the drive source M to stir the developer and supply the developer to the developing roller 171. During the development, the developer is supplied to the developing roller 171 while stirring.

On the other hand, in the image forming apparatus 200, a plurality of paper feed cassettes 30 and 301 are arranged.
Recording papers P and P1 of different sizes are stored in 0 and 301, respectively, and the recording paper P or P1 is fed by the paper feed roller 29 or 291 according to a size designation signal from the control device C. It is provided so that paper can be fed.

Further, a conveying member 2 provided on a recording paper conveying path
One sheet of recording paper P conveyed in 1 is temporarily stopped by the stop member 19, and when the transfer timing is adjusted, the stop member 19 is operated to release the recording paper P and fed to the transfer area. .

Next, the peripheral surface of the photosensitive drum 10 on which the toner image is formed and the transfer pole 2 are synchronized with the transfer timing.
The toner image formed on the surface of the photosensitive drum 10 is transferred to the recording paper P fed between the two by the transfer pole 22, and the recording paper P is removed from the peripheral surface of the photoconductor 101 by the charge eliminating action of the separation pole 23. After the separation, the sheet is conveyed to a heat fixing device (not shown), and the recording paper after fixing is discharged from the image forming apparatus 200.

Further, the photosensitive member 101 from which the recording paper P has been separated
Removes and cleans the residual toner by pressing the blade 28 of the cleaning device 27, removes the charge by the PCL (pre-charger) 15 again, and receives the charge by the corona charger 11 to perform the next image forming process. enter.

The paper feed cassettes 30 and 301 have detected portions 302 and 303 corresponding to the sizes of the recording papers P and P1.
Are formed. In order to detect the detected portions 302 and 303, detecting members S2 and S3 connected to the control device C via input / output portions C4 and C5 are provided. By arranging them at the positions of the detecting members S2 and S3, the sizes of the recording sheets P and P1 are automatically
It is input to the control device C via C5.

The recording paper P, P1 is passed by the recording paper detecting member S1 provided in the recording paper transport path, and further, the recording paper P, P
The conveyance passage detection and the size detection of P1 may be performed.

The control device C includes a nonvolatile memory ME.
Is built in, and the toner density value detected by the toner density detection member S is input to the control device C via the input / output unit C3,
The controller C determines the amount of toner shortage in the developing device 17, determines the operation time of the toner replenishing device 176, and inputs and stores the driving time in the nonvolatile memory ME.

The toner replenishing member 176 is driven by the drive source M1 for the operation time inputted and stored in the nonvolatile memory ME.
And the toner supply to the developing device 17 is performed, and the drive time during which the toner supply member 176 rotates is subtracted from the drive time stored in the nonvolatile memory ME.

FIG. 2 is a plan view showing the internal structure of the developing device 17.

The developing roller 171 and the developer main stirring member 17
2, and the developer conveying screw members 173 and 174 are rotatably supported by the developing device 17, and are provided with a developing roller by a gear G 1 which meshes with a source driving gear G 0 provided in the image forming apparatus 200 and rotates. A gear G3 for driving the gear 171 meshes with the gear G1 and is rotated in conjunction therewith. Further, the gear G2 provided integrally with the gear G1 drives and rotates the developer main stirring member 172, and the gear G2 and the developer conveying screw member 173 are rotated. A gear G4 that meshes with and drives and rotates is provided, and a gear G5 provided integrally with the gear G4 and a gear G6 provided on the developer conveying screw member 174 are provided so as to be rotated in conjunction with each other.

As shown in the figure, the toner supply opening 176A provided for toner supply from the toner supply device 175 is
174, the toner density detecting member S
Is disposed at a position upstream of the toner supply opening 176A so as to face the developer conveying screw member 173.

The developing device 1 is partitioned by the partitioning portions 177, respectively.
7, a developer conveying screw member 173, 1
Reference numeral 74 is provided so as to rotate in opposite directions by the interlocking gears G5 and G6.

When the toner T is replenished from the toner replenishing device 175 through the toner replenishing opening 176A, the toner T is transported together with the carrier in the Y direction while being agitated by the developer transport screw member 174. Notch 187
Are transported to the developer transport screw member 173 side via the developer transport screw member 173, and transported while being stirred by the developer transport screw member 173 in the X direction opposite to the Y direction. The toner and the carrier are agitated, the developer is sent to the main developer agitating member 172, and the developer having a predetermined toner charge amount is supplied to the developing roller 171 while being further agitated.
In step 1, the electrostatic latent image formed on the photosensitive drum 10 is developed.

The developer main stirring member 172 is provided for the developing roller 1.
In addition to supplying the developer to the developing roller 71, the developing roller 171 performs the development, and then returns the developer in which the toner T <b> 1 has been consumed to the position of the developer conveying screw member 173.

Here, the developing is performed by the developing roller 171, and the developer having consumed the toner T 1 is returned to the position of the toner concentration detecting member S by the developer conveying screw member 173. The toner density of the returned developer is detected by the toner density detecting member S, and the toner T1 consumed by the developer is detected.
Is detected, toner T corresponding to the consumed toner T1 is supplied from the toner supply device 175 to the developing device 17, and
The developer is mixed with the developer conveyed by the developer conveying screw member 173, and is again mixed with the developer conveying screw member 174.
173 supplies the developer to the developer main stirring member 172.

As a result of detecting the toner concentration of the developer in the developing device 17 by the toner concentration detecting member S, the toner in the developer is lower than a predetermined toner concentration. The driving time for driving the toner supply member 176 of the toner supply device 175 according to the amount is input to the nonvolatile memory ME.
Only when is driven, the toner replenishing member 176 is driven in accordance with the driving time to replenish toner to the developing device 17, and when the driving time stored in the nonvolatile memory ME becomes zero, the toner replenishment is performed. The member 176 is stopped.

This embodiment will be described in detail with reference to timing charts shown in FIGS. 3 (a) and 3 (b).

First, in FIG. 3A, a copy start button (not shown) of the image forming apparatus 200 is pressed, and the main body driving is started by the first copy operation. At this time, the recording paper P or the recording paper P1 having different sizes stored in the paper cassettes 30 and 301 is selected, and when the recording paper P is selected, the paper is fed from the paper cassette 30 by the paper feeding roller 29. However, in order to extend the deterioration of the photosensitive drum 10 and the developer as much as possible, the photosensitive drum 10 in the drum cartridge 100 and the developing device 1
7 is driven by the drive source M.

Further, the driving of the photosensitive drum 10 and the developing device 17 is continued until the toner image is transferred onto the recording paper P, and the driving is stopped immediately after the transfer is completed. Is done.

Therefore, the photosensitive drum 10 and the developing device 1
The drive of 7 stops before the drive of the main body stops. Here, the total drive time of the photosensitive drum 10 and the developing device 17 is, for example, 1.8 seconds.

Next, the toner density detecting member S does not detect the density until the toner density detecting performance sufficiently rises and reaches a predetermined measurable state. I do.

That is, the timer CT is activated at the same time as the driving of the driving source M is started, and after the timer CT set at the time T1 (for example, 1.4 seconds) measures 1.4 seconds, the toner concentration detecting member S causes the developer to be discharged. A read command signal A for measuring the toner density is transmitted from the control device C via the input / output unit C3.

The read command signal A is transmitted, and the toner density in the developer is measured by the toner density detecting member S. The measured toner concentration in the developer is input to the control device C via the input / output unit C3, and the input causes the toner replenishing member 176 to be driven by the drive source M1 in accordance with the measured toner concentration in the developer. The driving time to be driven is determined by the control device C.

As described above, by measuring the toner concentration in the developer, the amount of toner shortage is determined.
For example, if the toner supply member 176 is operated for 3.2 seconds,
When it is determined by the control device C that the toner concentration in the consumed developer has recovered, 3.2 seconds, which is the driving time of the toner supply member 176, is input and stored in the nonvolatile memory ME.

Next, after the toner concentration in the developer is measured, the driving time of the toner replenishing member 176 is input to the non-volatile memory ME, and the amount of toner in the developer in the developing device 17 is immediately regulated. Toner supply is started in order to restore the toner concentration to the above. First, a drive start signal for driving the drive source M1 is transmitted from the control device C via the input / output unit C3, and the toner supply member 176 starts to be driven by the drive source M1 to supply toner into the developing device 17. .

As described above, when 1.8 seconds, which is the total drive time of the photosensitive drum 10 and the developing device 17, has elapsed by the control device C, the image formation and the image transfer of the recording paper are completed.
The photosensitive drum 10 stops together with the developing device 17.

As described above, the reading command signal A is transmitted 1.4 seconds after the driving of the driving source M is started, and after the toner concentration is detected, the total driving time of the developing device 17 is 1.8. The driving source M1 is driven for 0.4 seconds indicated by the remaining driving time B from the second until the developing device 17 stops, and toner is supplied by the toner replenishing member 176. At the same time, the driving time B of the driving source M1 decreases. It is subtracted from the nonvolatile memory ME.

When the drive source M is stopped, the photosensitive drum 10 and the developing device 17 are stopped. At the same time, the drive source M1 is immediately stopped from the control device C via the input / output unit C2, and the toner supply by the toner supply member 176 is also stopped. Is done.

Toner replenishing member 1 by first copying operation
By the driving of 76, the driving time of 0.4 second is subtracted from the nonvolatile memory ME, and the remaining driving time is 2.8.
Seconds are recorded in the non-volatile memory ME.

By the first copy operation, the sheet cassette 3
The recording paper P fed from 0 is conveyed to the transfer area, the image on the photosensitive drum 10 developed by the developing device 17 is transferred to the recording paper P by the transfer pole 22, and is separated from the photosensitive drum 10 by the separation pole 23. After separating the recording paper P, an image is fixed on the recording paper P by a heat fixing device (not shown), and the recording paper P is discharged from the image forming apparatus 200.

Next, the second copy operation is started, and the second drive of the photosensitive drum 10 and the developing device 17 by the drive source M is started slightly after the start of the copy operation as described above.

At the time of the second copy operation, since the driving time of the toner supply member 176 is stored in the non-volatile memory ME, the photosensitive drum 10 and the developing device 17 are driven by the driving source M during the driving time B1. At the same time, the drive source M1 is immediately driven by the control device C via the input / output portion C2, and the toner supply member 176 starts to supply the developing device 17 with the toner T.

In this case, the driving time stored in the nonvolatile memory ME is subtracted by the driving time during which the toner supply member 176 is driven.

As in the case of the first copy operation, the timer CT in the control device C starts to operate at the same time as the drive of the drive source M is started, and the timer CT operates for 1.4 seconds (indicated by T1).
The toner replenishing member 176 is operated until the time elapses, and toner replenishment is performed. However, after the elapse of the 1.4 seconds, the toner in the developer is detected by the controller C via the input / output unit C3. A read instruction signal A is transmitted to detect the density.

When the read instruction signal A is transmitted, the toner density of the developer is detected by the toner density detecting member S, and the result of the detection is input to the control device C via the input / output unit C3.

A toner image is formed on the photosensitive drum 10 by the developing device 17. For example, as a result of the development by the developing device 17, the consumption of the toner T is extremely small, and the developer returned by the main stirring member 172 of the developing device 17 is removed. As a result of detecting the toner density by the toner density detecting member S, the controller C determines that the toner density is a predetermined density value, that is, the drive time is 0 (zero).
Therefore, the integration of the drive time for the nonvolatile memory ME is not performed.

Next, after the toner concentration is detected, the remaining driving time B2 from the total driving time of the developing device 17 of 1.8 seconds to the stop of the developing device 17 is 0.4 seconds indicated by B2.
When the drive source M1 is driven, toner is supplied by the toner supply member 176, and at the same time, the time
2 is subtracted from the nonvolatile memory ME.

Next, the third copy operation is started, and the toner supply component 176 is driven to the developing device 17 by the first and second copy operations, and the drive time stored in the nonvolatile memory ME is reduced. As a result of the subtraction, the one-second driving time remains in the non-volatile memory ME. When the driving of the photosensitive drum 10 and the developing device 17 is started by the driving source M, the driving of the developing device 17 and the control device are started. Input / output section C2 from C
, The drive source M1 is immediately driven, toner supply to the developing device 17 is started by the toner supply member 176, and toner is supplied to the development device 17 by the drive time B2 of the toner supply member 176.

Therefore, in the third time, the toner supply member 176 is driven by the drive time B3 of one second remaining in the nonvolatile memory ME, and toner is supplied to the developing device 17, and the remaining drive time B3
The toner supply member 176 is driven by the drive source M1 until the one-second drive time of 3, which is 3, and the one-second drive time B3 stored in the nonvolatile memory ME becomes zero. The driving source M1 stops via C2,
The toner supply member 176 is also stopped, and the total drive time of toner supply determined and stored in the first and second times is 3.
After the completion of 2 seconds, the developing device 17 is supplied with a toner amount capable of continuing development.

Similarly to the first and second copying operations, the timer CT in the control device C starts to operate at the same time as the driving of the driving source M is started, and the time of 1.4 seconds elapses by the timer CT ( T1), the control unit C sends the input / output unit C3
, The toner concentration in the developer is detected by the toner concentration detecting member S, but the toner consumption is extremely small and the developer returned by the developer main stirring member 172 of the developing device 17 is the same as in the second time. The controller C determines that the toner density is a predetermined density value, that is, the drive time is determined to be 0 (zero), and the integration of the drive time for the nonvolatile memory ME is not performed.

In the example described above, the toner T is consumed in the first copy operation, and the toner T is hardly consumed in the second and third copy operations. The toner supply is set to 0 (zero), but the following example is an example in which the toner T is consumed during the second copy operation and the toner T is hardly consumed in the third and fourth copy operations. .

FIG. 3 (b) shows another example in which the toner concentration in the developer is detected by the toner concentration detecting member S, and the driving time of the toner replenishing member is inputted and stored in the nonvolatile memory ME for replenishing the toner. 3 shows a timing chart.

In the description of the present embodiment, as shown in Table 1 together with the timing chart of FIG. 3B, the driving time inputted to the nonvolatile memory ME and the subtracted time are represented by specific times (seconds). ).

[0081]

[Table 1]

Also in the present embodiment, first, the copy start button (not shown) of the image forming apparatus 200 is pressed, and the main body driving is started by the first copy operation. For example, when the recording paper P is selected, the paper feed roller 2
9, the photosensitive drum 10 in the drum cartridge 100 is slightly delayed from the start time of the copying operation in order to extend the deterioration of the photosensitive drum 10 and the developer as much as possible.
Then, the driving of the developing device 17 by the driving source M is started.

Then, as in FIG. 3A, the drive is started by the drive source M with the total drive time for performing image formation and transfer by the photosensitive drum 10 and the developing device 17 being, for example, 1.8 seconds. Is done.

Next, when the driving of the driving source M is started, the photosensitive drum 10 and the developing device 17 are driven, but the toner density detecting member S has a sufficiently high toner density detecting performance and is in a predetermined measurable state. When the rise time T1 at which normal measurement is possible is not detected until the time when the density is detected, the density is detected.

That is, the timer CT is activated at the same time as the driving of the driving source M is started, and after the timer CT set at the time T1 (for example, 1.4 seconds) measures 1.4 seconds, the toner density detecting member S detects the developer in the developer. A read command signal A for measuring the toner density is transmitted from the control device C via the input / output unit C3.

The read command signal A is transmitted, and the toner density in the developer is measured by the toner density detecting member S. The measured toner concentration in the developer is input to the control device C via the input / output unit C3, and the input causes the toner replenishing member 176 to be driven by the drive source M1 in accordance with the measured toner concentration in the developer. The driving time to be driven is determined by the control device C.

In this way, the toner concentration in the developer is measured to determine the toner shortage. For example, if the toner replenishing member 176 is operated for 3.2 seconds, the toner concentration in the consumed developer is reduced. When it is determined by the control device C to recover, 3.2 seconds, which is the drive time of the toner supply member 176, is input and stored in the nonvolatile memory ME as shown in Table 1.

Next, after the toner concentration in the developer is measured, the driving time of the toner replenishing member 176 is inputted to the non-volatile memory ME, and the amount of toner in the developer in the developing device 17 is immediately regulated. The toner supply for recovering the toner concentration to the above is started.

First, a drive start signal for driving the drive source M1 is transmitted from the control device C via the input / output unit C3, and the toner supply member 176 starts driving by the drive source M1 to supply toner into the developing device 17. Is performed.

As described above, when 1.8 seconds, which is the total drive time of the photosensitive drum 10 and the developing device 17, has elapsed by the control device C, the image formation and the image transfer of the recording paper are completed.
The photosensitive drum 10 stops together with the developing device 17.

As described above, the read command signal A is transmitted 1.4 seconds after the start of driving of the drive source M, and after the toner density is detected, the total drive time of the developing device 17 is 1.8. The driving source M1 is driven for 0.4 seconds indicated by the remaining driving time B from the second until the developing device 17 stops, and toner is supplied by the toner replenishing member 176. At the same time, the driving time B of the driving source M1 decreases. It is subtracted from the nonvolatile memory ME.

When the drive source M is stopped, the photosensitive drum 10 and the developing device 17 are stopped. At the same time, the drive source M1 is immediately stopped from the control device C via the input / output unit C2, and the toner supply by the toner supply member 176 is also stopped. Is done.

Toner replenishing member 1 by first copy operation
By the driving of 76, the driving time of 0.4 seconds is subtracted from the nonvolatile memory ME as described in Table 1, and the remaining driving time of 2.8 seconds is 2.8 seconds at the end of the first copy. Recorded in the record.

3A, the recording paper P fed from the paper feed cassette 30 is transported to the transfer area by the first copy operation, and the photosensitive drum developed by the developing device 17 is used. 10 images are recorded on the recording paper P by the transfer pole 22
To the recording paper P from the photosensitive drum 10 at the separation pole 23.
Is separated from the recording paper P by a heat fixing device (not shown).
The recording paper P is discharged from the image forming apparatus 200 after the image is fixed on the recording paper P.

Next, a second copy operation is started, and a second drive of the photosensitive drum 10 and the developing device 17 by the drive source M is started slightly after the start of the copy operation as described above.

At the time of the second copying operation, since the driving time of the toner supply member 176 is stored in the nonvolatile memory ME, the photosensitive drum 10 and the developing device 17 are driven by the driving source M at the same time. The drive source M1 is immediately driven by the control device C via the input / output unit C2, and the toner supply member 176 starts supplying toner T to the developing device 17.

In this case, the drive time stored in the non-volatile memory ME is subtracted by the drive time B1 during which the toner supply member 176 has been driven, ie, 1.4 seconds.

Then, similarly to the first copy operation, the timer CT in the control device C starts to operate at the same time as the driving of the driving source M is started, and the timer CT operates for 1.4 seconds (indicated by T1).
The toner replenishing member 176 is operated until the time elapses, and toner replenishment is performed. However, after the elapse of the 1.4 seconds, the toner in the developer is detected by the controller C via the input / output unit C3. A read instruction signal A is transmitted to detect the density.

The read instruction signal A is transmitted to detect the toner concentration of the developer by the toner concentration detecting member S, and the result of the detection is input to the control device C via the input / output unit C3.

A toner image is formed on the photosensitive drum 10 by the developing device 17. For example, as a result of development by the developing device 17, a large amount of toner T is consumed in the second copy operation, and is consumed by the developing device 17. The driving time of the toner replenishing member 176 is determined based on the consumption amount of the toner T by the nonvolatile memory ME.
And memorize it.

For example, when the toner density of the toner density detecting member S is detected for the second time, the toner supply member 176 for 1.2 seconds is detected.
When the control unit C determines that the predetermined toner concentration is reached by driving the non-volatile memory ME, a driving time of 1.2 seconds is newly stored in the non-volatile memory ME for the second time as described in Table 1. The integration is input from C and accumulated.

The drive time stored in the nonvolatile memory ME is obtained by subtracting the drive time of 1.4 seconds from the drive time of 2.8 seconds stored in the nonvolatile memory ME at the time of the second copy operation. However, since 1.2 seconds are added, the time is 2.6 seconds.

As described above, after the read command signal A for detecting the toner density, the photosensitive drum 10 and the developing device 1
The toner replenishing device 176 is driven for 0.4 seconds with a drive time B2 until the stop of the toner 7, and toner replenishment is performed, and a drive time of 2.2 seconds remains in the nonvolatile memory ME.

Next, the third copy operation is started, and the toner supply component 176 is driven to the developing device 17 by the first and second copy operations, and the drive time stored in the nonvolatile memory ME is reduced. As a result of the subtraction, a drive time of 2.2 seconds remains in the nonvolatile memory ME, and when the drive of the photosensitive drum 10 and the developing device 17 is started by the drive source M, the driving of the developing device 17 is started. The drive source M1 is immediately driven from the control device C via the input / output unit C2, and at the same time, the timer CT starts operating. The toner supply member 176 uses the toner supply member 176 until 1.4 seconds (indicated by T1) of the timer CT elapse. The toner is supplied to the developing device 17, and the toner is supplied to the developing device 17 for 1.4 seconds during the driving time B3 of the toner supply member 176.

Next, when 1.4 seconds (indicated by T1) elapses on the timer CT, the control device C transmits the read designation signal A, and the toner density of the developing device is detected by the toner density detecting member S, and the detection result is obtained. To the control device C via the input / output unit C3.
To enter.

As a result of detecting the toner density at the third time, the consumption of the toner T in the developing device 17 is extremely small, and the toner density of the developer returned by the main stirring member 172 of the developing device 17 is determined by the toner density detecting member S. As a result of the detection, the toner density is a predetermined density value.
It is determined as (zero), and the integration of the drive time for the nonvolatile memory ME is not performed.

Next, as described above, after the read command signal A for detecting the toner density is transmitted, the photosensitive drum 10
And the drive time B4 until the developing device 17 stops is 0.4
The toner replenishing member 176 is driven by the driving source M1 for the amount of seconds, and the driving time stored in the nonvolatile memory ME at the end of the third time is 0.4 seconds.

Next, the fourth copy operation is started, and
In the second, third, and third copying operations, the toner replenishing member 176 is driven to the developing device 17 and the driving time stored in the nonvolatile memory ME is subtracted. Remaining in the non-volatile memory ME, when the drive source M starts driving the photosensitive drum 10 and the developing device 17,
The driving source M1 is immediately driven by the control device C via the input / output portion C2, and the toner supply to the developing device 17 is started by the toner replenishing member 176. .4 seconds of toner replenishment, and as described in the fourth time in Table 1, the nonvolatile memory ME
The toner replenishing member 176 is driven until the driving time remaining in the developing unit becomes 0 (zero), and replenishes the developing device 17 with toner.

The driving time remaining in the non-volatile memory ME becomes 0 (zero), the toner supply by the toner supply member 176 is completed, and the developing device 17 is sufficiently supplied with toner.

In this state, the input / output unit C2 is
The drive source M1 is driven via the, and drives the photosensitive drum 10 and the developing device 17 to form an image.

Further, after the driving of the driving source M1 is started, the timer C
When 1.4 seconds (indicated by T1) elapse at T, the toner concentration detecting member S detects the toner density of the developing device by transmitting the read designation signal A from the control device C, and the result of the detection is transmitted via the input / output unit C3. After that, the photosensitive drum 10 and the developing device 17 are driven by the drive source M1 for 0.4 second, which is the remaining drive time of 1.8 seconds, to complete image formation.

In the above description, at least the photosensitive drum 1
Although the embodiment has been described in which the driving source M is provided in the drum cartridge 100 having the developing device 17 and the developing device 17, for example, a driving source that independently drives only the developing device 17 may be provided.

When a drive source is provided independently of the developing device 17, the developing device 17 may be operated only when the electrostatic latent image on the photosensitive drum 10 is being developed. The operation time can be shortened, and the deterioration of the developer can be delayed.

Embodiment 2 In Embodiment 2, the toner density of the developer is detected by the toner density detecting member S, and recording paper size information and scaling information for recording an image by the image forming apparatus are input to the control device. Then, the toner density of the developing device is maintained at a predetermined density.

For example, in the image forming apparatus 200, the amount of toner used when an image is formed with the recording paper P having a small size of B5, A5, and B6, and the recording paper P1 is defined as A3, B4
The amount of toner used when an image is formed as a large plate size differs considerably. In particular, when a toner image such as a photograph or solid black is formed on a large-size recording paper P1, the amount of toner used is large, and the toner in the developer runs short due to the small amount of toner replenishment. When an image including only characters is partially formed on the plate-size recording paper P, the amount of toner used becomes extremely small, and the toner in the developer tends to be excessive when the amount of toner supplied for a large plate is large.

As described above, since the amount of toner used varies depending on the size of the recording paper, the fluctuation in the toner concentration of the developer in the developing device 17 becomes large when the toner is replenished for a fixed replenishing time, and problems such as image fog and toner scattering are caused. Or a problem such as image blurring due to a decrease in toner density is likely to occur. In addition, when the photosensitive drum 10 and the developing device 17 are provided as separate driving sources in order to extend the durability and the driving time of the developing device 17 is shortened, the above-described problem tends to occur remarkably.

As shown in FIG. 4A described above,
A4R A4 size document is placed vertically and fed vertically
When a 71% reduced image is recorded on a recording sheet P of a size, the image is directly reduced and recorded on the recording sheet P.

As described above, FIG. 4 (b)
When an A3-size original is placed in the vertical direction and a 50% reduced image is recorded on an A4-size recording paper P which is fed horizontally, an image is recorded on the A4-size recording paper P at half the image size.

As described above, depending on the feeding direction of the recording paper P and the reduction ratio, there is more blank space where no image is recorded on the recording paper P.

Accordingly, as described above, although the image size varies depending on the original placement position and the selected size of the recording paper P or the feed direction, the image size and the arrangement position, and the information of the selected recording paper P are not changed. The magnification information is input to the control device C via the input / output unit C4, and the control device C controls the reflection mirror 161 and the lens 16 by the scaling means 400 via the input / output unit C4.
4. By operating the reflection mirror 165 to the variable power position, the controller C can obtain image size information.

Therefore, the amount of toner consumption changes with a change in image size, and when toner is replenished for a fixed toner replenishment time, the fluctuation in the toner concentration of the developer in the developing device 17 becomes large, and image fog and toner Problems such as scattering,
Alternatively, a problem such as image blurring due to a decrease in toner density is likely to occur.

Further, in particular, the photosensitive drum 10 and the developing device 17
In order to extend the durability of the developer, the above-described problem is likely to occur remarkably even when the driving time is shortened by driving the developing device 17 by another driving source.

As described above, while detecting the toner density in the developing device, the recording paper size to be used and the scaling information are input to the control device of the image forming apparatus, and the toner is determined in accordance with the input information. The supply amount is controlled by the control device C, and the toner amount in the developer in the developing device 17 is adjusted to an appropriate amount by the control, thereby obtaining a good image.

The following is a description according to Table 2.

[0125]

[Table 2]

As shown in Table 2, the toner density detecting member S
, The output voltage value V when the concentration of the developer is detected
L (V) to the recording paper size (small size B5, A
5, a driving time (second) for driving the toner supply member 176 corresponding to the size (B6).

The output voltage value VL (V) shows the state where the toner density in the developer is the lowest in the upper row, and the state where the toner density is higher in the lower row.

First, when a voltage value whose output voltage value VL is 1.8 or more is input to the control device C by the detection of the toner density detecting member S, and the recording paper of the recording paper size B5, A5, B6 is selected. Indicates that the driving time of the toner supply member 176 is 1.9 seconds, and that the recording paper size A4 is selected.
If the recording paper sizes A3 and B4 are selected for one second,
The toner is temporarily stored in the memory so as to be driven for 3.5 seconds, and toner is supplied to the developing device 17 by the toner supply member 176 according to the driving time.

When the output voltage value VL (V) is input to the control device C from 1.70 V to 1.80 V by the detection of the toner density detection member S, the recording paper sizes B5, A5, B6
Is selected, the toner supply member 176
Is temporarily stored in the memory so as to be driven for 1.0 second, 1.1 seconds when the recording paper size A4 is selected, and 2.0 seconds when the recording paper sizes A3 and B4 are selected. Then, toner is supplied to the developing device 17 by the toner supply member 176 according to the driving time.

Hereinafter, similarly, as shown in Table 2, the output voltage value VL (V) is 1.6 by the detection of the toner density detecting member S.
The toner supply time at a voltage value VL of 5V to 1.70V, 1.65V to 1.70V, 1.60V to 1.65V, 1.55V to 1.60V, and 1.55V or less is shown. I have.

As described above, when recording paper of various sizes is fed, the amount of toner consumption differs depending on the size of the recording paper.
2, or the detected part 303 provided in the paper feed cassette 301
When the selected recording paper size information is input to the control device C, the toner density in the developer changes, and the output voltage value VL (V) changes due to the detection of the toner density detecting member S, the recording is performed. The toner supply member 176 is driven by the drive source M1 based on the paper size information and the output voltage value VL (V) information detected by the toner density detection member S, and an appropriate amount of toner is supplied into the developing device 17, thereby obtaining toner. This prevents the shortage from occurring.

In addition to the detection of the toner density by the toner density detecting member S, the selected recording paper size is input to the control device C. Further, when performing image recording, the recording paper corresponding to the original size is not used. For example, when a reduced copy is performed by a scaling operation, the toner is consumed according to the image size, so that the toner consumption is different. In this case, since the toner is not necessarily consumed according to the recording paper size, the recording paper size, the document size information, and the scaling information are input to the control device C as described above, and the image size determined by the control device C is reduced to the image size. On the other hand, if the toner supply amount is controlled, finer control of the toner density is possible.

[0133]

As described above, according to the present invention, there is provided a developing device for developing an electrostatic latent image formed on an image carrier with a developer comprising a mixture of a toner and a carrier. An image forming cartridge having the image carrier and the developing device; a driving unit provided separately from the image forming device for driving at least the developing device; and a toner replenishing device for replenishing the developing device with toner. And a toner concentration detecting means for detecting the toner concentration of the developer, wherein the toner replenishing device is driven in accordance with the toner concentration value detected by the toner concentration detecting means of the developer. A storage unit for storing a time, and driving the toner supply device in accordance with the driving time stored in the storage unit only when the developing device is driven by the driving unit. By controlling the control means,
The toner concentration detecting means detects the amount of toner consumed in the developer, stores the driving time of the toner replenishing device in the storage means according to the consumed toner amount, and stores the toner for the replenishing time stored in the storing means. Since the replenishing device is driven, the toner is reliably replenished to the developing device according to the toner shortage.
In this way, the developer is reliably replenished with the toner corresponding to the consumption of the toner, so that there is no shortage of the toner, and the toner and the developer are surely agitated, so that good image formation is always achieved. Can be performed.

According to a second aspect of the present invention, since the storage means is a non-volatile memory, the driving time of the toner replenishing device is stored in the non-volatile memory. Even when the main switch is turned off, the driving time of the toner replenishing device is stored, and the toner is reliably replenished by the stored driving time until the inside of the developer reaches a predetermined toner density.

According to a third aspect of the present invention, the non-volatile memory accumulates and stores the toner supply time each time the toner concentration is detected by the toner concentration detection means, and stores the drive time during which the toner supply device is driven. When the stored driving time becomes zero, the control unit controls the toner replenishing device to stop when the stored driving time becomes zero, so that the toner in the developer in the developing device is consumed. When the consumed toner amount is detected by the toner concentration detecting means, the insufficient toner supply amount is detected each time the developing device is driven, and the toner supply time is integrated and stored in the non-volatile memory. It is possible to reliably detect the amount of toner consumed by the device and accurately input the drive time for driving the toner replenishing device to the nonvolatile memory according to the amount of toner shortage. Ri, since reliably toner replenishing device After supplying toner required amount in the developing device is stopped, thereby preventing the toner shortage in the developing device,
Excessive supply of toner can also be prevented.

A developing device for developing an electrostatic latent image formed on an image carrier with a developer comprising a mixture of a toner and a carrier, at least the image carrier, and the developing device An image forming cartridge having:
A driving unit provided separately from the image forming apparatus for driving at least the developing device, a toner replenishing device for replenishing toner to the developing device, a toner density detecting unit for detecting a toner density value of the developer, In order to transfer the image formed on the image carrier, to select a sheet to be fed from a plurality of sizes of sheets, in the image forming apparatus having a sheet feeding device to feed the selected sheet, In accordance with the toner density value detected by the toner density detecting means, the selected sheet size information, and the image size information formed on the sheet, the replenishment time for replenishing the toner from the toner replenishing device to the developing device is set. By having control means for controlling, the sheet size information and the image information formed on the sheet with the scaling information are accurately input to the control device, and corresponding to the image information Since the toner is replenished to the developing device by the toner replenishing device, the toner does not become insufficient or excessive due to a change in image size, and it is possible to always supply an appropriate amount of toner in the developer, Since more stable toner density control is performed, good image formation can always be performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an image forming apparatus that performs toner supply control according to the present invention.

FIG. 2 is a plan view showing an internal mechanism of the developing device of the present invention.

FIG. 3 shows a timing chart for performing toner supply control of the present invention.

FIG. 4 is an explanatory diagram showing image size information at the time of zooming according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 photoconductor drum 11 corona charging device 17 developing device 100 drum cartridge 171 developing roller 172 developer main stirring member 173, 174 developer conveying screw member S toner concentration detecting member T toner 175 toner replenishing device 176 toner replenishing member C control device C1 , C2, C3, C4, C5 Input / output section M, M1 Drive source ME Non-volatile memory 30, 301 Paper feed cassette 302, 303 Detected section S1 Recording paper detecting member S2, S3 Detection member P Recording paper

Claims (4)

[Claims] 1. A developing device for developing an electrostatic latent image formed on an image carrier with a developer comprising a mixture of a toner and a carrier, and an image forming apparatus comprising at least the image carrier and the developing device A cartridge, at least a driving unit provided separately from the image forming apparatus for driving the developing device, a toner replenishing device for replenishing toner to the developing device, and a toner concentration detecting unit for detecting a toner concentration of the developer A storage unit for storing a driving time of the toner replenishing device in accordance with a toner density value detected by a toner density detecting unit of the developer; Only when driven,
An image forming apparatus, wherein the control unit controls the toner replenishing device to be driven according to the driving time stored in the storage unit. 2. The image forming apparatus according to claim 1, wherein the storage unit is a nonvolatile memory. 3. The non-volatile memory accumulates and stores a toner replenishment time every time the toner density is detected by the toner density detection means, and subtracts a drive time during which the toner replenishment device is driven. 3. The image forming apparatus according to claim 2, wherein the control unit controls the toner supply device to stop when the drive time becomes zero. 4. A developing device for developing an electrostatic latent image formed on an image carrier with a developer comprising a mixture of a toner and a carrier, and an image forming apparatus comprising at least the image carrier and the developing device A cartridge, a driving source provided at least separately from the image forming apparatus for driving the developing device, a toner replenishing device for replenishing toner to the developing device, and a toner density detecting device for detecting a toner density value of the developer Means for selecting a sheet to be fed from a plurality of sizes of sheets for transferring an image formed on the image carrier, and a sheet feeding device for feeding the selected sheet to an image forming apparatus. The toner replenishment is performed according to the toner density value detected by the toner density detection unit, the selected sheet size information, and the image size information formed on the sheet. An image forming apparatus comprising: a control unit that controls a replenishing time for replenishing toner from the device to a developing device.