JPH04336567A - Toner replenishment device - Google Patents

Abstract

PURPOSE:To enable a troublesome work such as shifting a large amount of toner to be eliminated, the quantity of parts to be reduced, the constitution of a device to be simplified, the device to be made free from non-operation state due to toner depletion, and finally stable toner replenishment to be ensured. CONSTITUTION:A toner replenishment device is provided with the first toner hopper to replenish a developing machine with toner, the second toner hopper to replenish the first toner hopper with toner and a toner detection sensor 1 to detect toner depletion state in the first toner hopper. The device is further provided with a toner detection sensor 2 to detect toner depletion state in the second toner hopper, a display means 3 and a control means 4 to cause the display means 3 to indicate for toner feed to the second toner hopper, when the sensors 1 and 2 concurrently detect toner depletion state.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner replenishing device for image forming apparatuses such as copying machines, printers, and facsimile machines.

0002

2. Description of the Related Art In image forming apparatuses such as copying machines, printers, and facsimile machines, a latent image is generally formed on an image carrier, and this latent image is developed with a two-component developer using a developing device to form a visible image. This developed image is transferred to a transfer material. Then, the toner concentration of the two-component developer in the developing device is detected by a toner concentration sensor, and based on the detection signal of this toner concentration sensor, toner is replenished from the toner replenishing device to the two-component developer in the developing device to perform development. The toner concentration of the agent is controlled to be constant.

The above toner replenishing device has a toner hopper which has a relatively small capacity and stores toner, and the toner is supplied from the toner hopper to the two-component developer in the developing device by rotation of a toner replenishing roller. There is. moreover,
The out-of-toner sensor detects that the toner in the toner hopper is out of toner (or there is no toner at all, or a state close to it), and the display section displays the out-of-toner condition, and the toner hopper is filled with toner. The operator is encouraged to replenish toner in the toner hopper by replacing it with a new one.

[0004] Furthermore, when a toner hopper with a large capacity is used, and the toner in the toner hopper becomes empty and the display indicates that the toner is out, another large container containing toner is used. There is a toner replenishing device ■ that transfers a large amount of toner from a large container to a toner hopper with a large capacity.

Japanese Patent Laid-Open No. 2-234177 discloses a plurality of toner hoppers attached to a developing device, a conveying means for conveying the toner contained in each toner hopper to the developing device, and a plurality of toner hoppers attached to the toner hopper. a toner detection means for detecting stored toner, a door for opening and closing an opening of the toner hopper, an opening/closing detection means for detecting opening and closing of the door, and using the toner hopper in a predetermined order, A toner supply device (2) is described which is characterized in that it includes a control means that executes a toner supply operation after confirming that each toner hopper is empty when the door is opened.

Furthermore, a first toner hopper with a relatively small capacity and a second toner hopper with a relatively large capacity are provided, and the toner is transferred from these toner hoppers to the developer in the developing device via a conveyance path. A toner replenishing device (2) has been proposed which supplies toner so that the toner concentration is constant.

[0007]

[Problem to be solved by the invention] The above toner supply device■
Now, when the toner in the large-capacity toner hopper becomes out of toner and the display shows the toner out state, a large amount of toner is transferred from the large container to the large-capacity toner hopper, so this large amount of toner is transferred. The troublesome work of moving is required.

Furthermore, in the toner supply device (2), a large amount of toner is divided and stored in a plurality of toner hoppers, and each toner hopper is provided with a toner detection means, a door, and an opening/closing detection means, so the number of parts increases. This will increase costs. Moreover, as the number of toner detection means increases, the control means becomes complicated and reliability decreases.

Furthermore, in the toner replenishing device (2), the user is not notified when both of the toner hoppers are out of toner, so the stopped state continues for a long time until the image forming operation becomes possible. I often end up. Moreover, when both toners in the two toner hoppers become empty, the toner from the second toner hopper is removed because the conveyance path from the second toner hopper, which has a relatively large capacity, to the developing device is long. It takes a long time for the toner to reach the developing device, making it difficult to replenish the toner stably.

The present invention improves the above drawbacks, eliminates the need for the troublesome work of transferring a large amount of toner, reduces the number of parts, and
Simplified configuration, prevention of stoppage due to no toner,
An object of the present invention is to provide a toner replenishing device capable of stably replenishing toner.

[0011]

[Means for Solving the Problems] In order to achieve the above object, the invention of claim 1 forms a latent image on an image bearing member, develops this latent image with a two-component developer using a developing device, and develops the latent image with a two-component developer. A toner replenishing device of an image forming apparatus that replenishes toner to a two-component developer in the developing device includes a first toner hopper that replenishes toner to the two-component developer in the developing device; a second toner hopper that replenishes toner to the first toner hopper and has a larger capacity than the first toner hopper; a first toner detection sensor 1 that detects an empty state of toner in the first toner hopper; a second toner detection sensor 2 that detects a toner-free state in a second toner hopper; a display unit 3 that displays a message for replenishing toner to the second toner hopper;
The display is performed when the first toner detection sensor 1 and the second toner detection sensor 2 simultaneously detect the toner out state based on the detection signals from the first toner detection sensor 1 and the second toner detection sensor 2. A control means 4 for displaying a display for causing the means 3 to replenish toner to the second toner hopper. As shown in FIG. When the toner out state is detected, the display means 3 displays a message for replenishing toner to the second toner hopper, and when the second toner detection sensor 2 detects the toner presence state, the display means 3 displays a message for replenishing the toner toner hopper. According to a third aspect of the present invention, in the toner replenishing device according to claim 2, the toner replenishing device comprises a control means 5 for increasing the amount of toner supplied from the second toner hopper to the first toner hopper. The control means simultaneously causes the first toner detection sensor 1 and the second toner detection sensor 2 to be in a toner-free state based on the detection signals from the first toner detection sensor 1 and the second toner detection sensor 2. When the toner presence state is detected, the display means 3 displays a message for replenishing toner to the second toner hopper, and after that, when the second toner detection sensor 1 detects that there is toner, the first control means 6 for increasing the amount of toner supplied from the second toner hopper to the first toner hopper until the toner detection sensor 1 detects the toner presence state;
It consists of

0012

According to the first aspect of the invention, toner is replenished from the first toner hopper to the two-component developer in the developing device, and toner is replenished from the second toner hopper to the first toner hopper. A toner-free state in the first toner hopper is detected by a first toner detection sensor 1, and a toner-free state in the second toner hopper is detected by a second toner detection sensor 2. Then, the control means 4 controls the first toner detection sensor 1 and the second toner detection sensor 2 based on the detection signals from the first toner detection sensor 1 and the second toner detection sensor 2.
When the toner detection sensor 2 simultaneously detects the out-of-toner state, the display means 3 displays a message for replenishing toner to the second toner hopper.

According to the second aspect of the invention, in the toner replenishing device according to the first aspect, the control means 6 controls the first toner detection sensor according to the detection signals from the first toner detection sensor 1 and the second toner detection sensor 2. When the first toner detection sensor 2 and the second toner detection sensor 2 simultaneously detect the toner out state, the display means 3 displays a message for replenishing toner to the second toner hopper, and then the second toner detection sensor 2 detects the toner state. When the presence state is detected, the amount of toner supplied from the second toner hopper to the first toner hopper is increased.

According to the third aspect of the invention, in the toner replenishing device according to the second aspect, the control means 6 controls the first toner detection sensor according to the detection signals from the first toner detection sensor 1 and the second toner detection sensor 2. When the first and second toner detection sensors 2 simultaneously detect the out-of-toner state, the display means 3 displays a message for replenishing toner to the second toner hopper, and then the second toner detection sensor 1 detects the toner state. The amount of toner supplied from the second toner hopper to the first toner hopper is increased from the time when the toner presence state is detected until the time when the first toner detection sensor 1 detects the toner presence state.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 4 schematically shows an example of an electronic copying machine to which the present invention is applied. In this electronic copying machine, an automatic document feeder 12 is mounted on the top of a main body 11 of the copying machine. The automatic document feeder 12 transports documents such as sheet documents and computer printouts to the document table 1 on the copying machine main body 11.
3, and after copying (after exposure), the paper is ejected to its own paper ejection tray or other paper ejection trays 14 and 15.

In the copying machine main body 11, an image carrier 16 made of a photoreceptor belt is rotated by a drive source during a copying operation and is uniformly charged by a charger 17, after which an original image is exposed by a full-surface exposure device 18. An electrostatic latent image is formed. The full-surface exposure device 18 instantly illuminates the document on the document table 13 with a light source 19 via a mirror 20 and forms a reflected light image on the photoreceptor belt 16 via a mirror 21, a lens 22, and a mirror 23. As a result, an electrostatic latent image is formed on the photoreceptor belt 16.

The electrostatic latent image on the photoreceptor belt 16 is developed into a developed image by a developing device 24, and a transfer material made of transfer paper is fed from a selected one of paper feed devices 25 to 27 to a registration roller. The sheet is fed to the recording roller 28, and sent out by the registration roller 28 with its leading edge aligned with the developed image on the photoreceptor belt 16. This transfer paper is subjected to corona discharge by the transfer charger 29 so that the developed image on the photoreceptor belt 16 is transferred onto the surface thereof, and is conveyed by the conveyor belt 30 to the fixing device 31.
By fixing the visible image, it becomes a one-sided copy. This single-sided copy is discharged onto a tray 32 when a single-sided copy is made, and onto an intermediate tray 33 when a double-sided copy is made. The document discharged to the intermediate tray 33 is fed to the registration rollers 28 with the front and back sides reversed by the paper feed section 34, and the document image is copied on the back side in the same way as in the case of front side copying described above, resulting in a double-sided copy. It is discharged onto the tray 32.

Further, residual toner is removed from the photoreceptor belt 16 by a cleaning device 35 after the image transfer, making the next copy possible. The above-mentioned copying operation is started by turning on the print switch on the operation display section and inputting a copy operation start signal, and is continuously performed for each document by the number of copies set by the ten keys on the operation display section.

FIG. 5 shows the structure of the developing device 24. The developing device 24 includes a developing device 24a that develops the electrostatic latent image on the photoreceptor belt 16 using a two-component developer;
and a toner replenishing device 24b for replenishing toner. In the developing device 24a, a plurality of developing rollers 36 to 3 are arranged facing the photoreceptor belt 16.
8, magnets 39 to 41 are arranged inside each of the developing rollers 36 to 38, and these magnets 39 to 41 are connected to the holder 4.
2 to 44 are fixedly held. A powdered two-component developer consisting of toner and carrier is stored in the developer container 45, and the carrier is made of a magnetic material. The toner is composed of toner particles alone or with adjuvants added thereto. Developing roller 36-3
Reference numeral 8 is made of a non-magnetic material and is driven to rotate clockwise by a driving source.

The paddle wheels 46 and 47 are rotationally driven by a driving source, and the developer in the developer container 45 is agitated by the paddle wheels 46 and 47 and supplied to the developing roller 38 located at the most downstream side. This developer is drawn up by the cooperation between the rotation of the developing roller 38 and the magnetic force of the magnet 41 inside the developing roller 38, and is regulated to a constant amount by the doctor blade 48.
After the liquid is pumped up by the cooperation with the magnetic force of the magnet 40 inside, the rotation of the developing roller 36 at the most upstream side and the developing roller 3
In cooperation with the magnetic force of the magnet 39 in the developer roller 6 , the developer is drawn up and scraped by the separator 49 from the developing roller 36 into the developer container 45 . In this way, the developer is circulated, and when the developer is conveyed by the developing rollers 36 to 38, it is supplied to the photoreceptor belt 16 and develops the electrostatic latent image on the photoreceptor belt 16. Developing roller 36 in the developer circulation path
A toner concentration sensor 50 is installed at a position after the developer passes, and this toner concentration sensor 50 detects the toner concentration of the developer.

As development is performed by the developing device 24a, the toner in the developer in the developer container 45 is gradually consumed, and the toner concentration of the developer gradually decreases. If this is left unaddressed, the density of the developed image developed by the developing device 24a will decrease and the image quality will deteriorate. To cope with this, toner is supplied to the developing device 24a from the toner hopper 51 in the toner supply device 24b by the rotation of the toner stirring member 53 and the toner supply roller 52. In this case, when the toner concentration of the developer is detected by the toner concentration sensor 50 and the control device detects from the detection signal that the toner concentration has decreased below the reference value, the first toner replenishment motor causes the toner replenishment roller 52 to The toner agitating member 53 is rotationally driven to supply toner from the toner hopper 51 to the developing device 24a, thereby controlling the toner concentration to a predetermined value.

Furthermore, in the toner replenishing device 24b,
The toner hopper 51 has a relatively small capacity,
The toner hopper 54 has a relatively large capacity. For example, the volume of the toner hopper 54 is about 6 to 7 times that of the toner hopper 51. The bottom of the toner hopper 54 and the top of the toner hopper 51 contain toner (for replenishment).
A conveyance pipe 55 is connected, and a coil (or auger) 56 for conveying toner is installed inside the toner conveyance pipe 55 . The toner hoppers 51 and 54 each have a toner-free state near the bottom (a state where there is no toner at all or a state close to it), for example, a state where a small amount of toner remains and the state is close to running out of toner (hereinafter referred to as toner near-end). Toner detection sensors 57 and 58 are attached for detection, and these toner detection sensors 57 and 58 detect each toner near end in the toner hoppers 51 and 54. Although piezoelectric sensors are used as the toner detection sensors 57 and 58, a light transmission type sensor or the like may also be used. Further, a toner stirring member 59 is installed inside the toner hopper 54, and a toner cartridge 60 is installed above the toner hopper 54. The toner cartridge 60 also serves as a lid for opening and closing the upper opening of the toner hopper 54, and supplies toner to the toner hopper 54. A sealing member for preventing toner scattering is provided around the toner cartridge 60, and these members prevent toner from scattering from the toner cartridge 60 to the outside.

The toner in the toner hopper 51 is transferred to the developing device 2.
By replenishing toner to 4a, the toner detection sensor 57 detects whether the remaining amount of toner in the toner hopper 51 has become below a certain value, thereby determining whether the toner hopper 51 has reached the toner near end. Detect. When the toner hopper 51 reaches the toner near end based on a detection signal from the toner detection sensor 57, the control device activates the toner stirring member 59 by the second toner replenishment motor.
Then, the toner conveying coil 56 is rotated, and the toner in the toner hopper 54 is agitated by the toner stirring member 59, and the toner conveying coil 56 passes through the toner conveying pipe 55 and is replenished into the toner hopper 51. The volume of the toner hopper 54 is about 6 to 7 times that of the toner hopper 51, so if the toner hopper 54 is sufficiently supplied with toner, the operator will be able to use it more easily than a normal copying machine that only has the toner hopper 51. The amount of copies that can be made without toner replenishment is about 6 to 7 times larger than usual.

FIG. 6 is an external view of this copying machine. This copying machine is provided with a copying machine main body 11 and a toner supply section 61, and the toner supply section 61 includes the above-mentioned toner hopper 54, toner cartridge 60, and the like. The toner hopper 54 is connected to the toner hopper 51 in the copying machine main body 11 via a toner transport pipe 55, and the cleaning device 35 in the copying machine main body 11 and the toner collection bottle (or toner cartridge 60) are connected to the toner collection transport pipe 55. 62. The toner removed from the photoreceptor belt 16 by the cleaning device 35 is transferred to a toner collection bottle (or toner cartridge 6) via a toner collection transport pipe 62.
0).

FIG. 7 shows the circuit configuration of this copying machine. A CPU 63 that controls each part of this copying machine, a ROM 64 that contains a control program, and an I/O 65 that is in charge of inputting and outputting signals to and from the CPU 63 constitute a control device.
is connected to the ROM 64 and I/O 65, and is also connected to the operation display section 67 via the serial communication port 66. Further, the I/O 65 is connected to each part including the toner concentration sensor 50, toner detection sensors 57 and 58, a motor drive circuit 68, and other sensors of this copying machine, and the motor drive circuit 68 is connected to the first toner replenishment motor. 69, connected to the second toner replenishment motor 70.

The CPU 63 operates according to the control program stored in the ROM 64, and operates via the serial communication port 6.
It communicates serially with the operation display section 67 via the operation display section 6 to input signals from operation keys and the like of the operation display section 67, and causes the display devices such as light emitting diodes and liquid crystals of the operation display section 67 to perform various displays. Further, the CPU 63 receives input signals from sensors and the like via the I/O 65, and controls each part of the copying machine via the I/O 65 to perform the above-described copying operation. Furthermore, the CPU 63 receives detection signals from the toner concentration sensor 50 and toner detection sensors 57 and 58 via the I/O 65, and controls the motor drive circuit 68 via the I/O 65 to operate the toner supply motors 69 and 70. Control.

FIG. 8 shows a part of the processing flow of the CPU 63, and FIGS. 9 and 10 show timing charts of this copying machine. When the CPU 63 receives a copying operation start signal from the operation display section 67 via the serial communication port 66, the CPU 63 starts the R
Control of toner replenishment is started according to the program contents in the OM 64, and first, the motor drive circuit 6 is controlled via the I/O 65.
8 to rotate the toner supply motor 70 at a duty ratio of 30%. As a result, toner is replenished from the toner hopper 54 to the toner hopper 51, and the amount of toner replenished is usually approximately equal to the amount of toner replenished from the toner hopper 51 to the developing device 24a.

Next, the CPU 63 detects the toner detection sensor 58.
It is checked whether the detection signal S2 from the toner detection sensor 57 and the detection signal S1 from the toner detection sensor 57 are at low level (L). Here, when the detection signals S1 and S2 are L, it means a toner near-end detection state. When the amount of toner consumed by the developing device 24a is larger than normal, the amount of toner supplied from the toner hopper 54 to the toner hopper 51 cannot keep up with the amount of toner consumed by the developing device 24a. When the detection signal S2 from the toner detection sensor 58 becomes L and the detection signal S1 from the toner detection sensor 57 becomes L, the CPU 63 displays the toner hopper on the display of the operation display section 67 via the serial communication port 66. A message for replenishing toner to 54 is displayed. Here, the user or the like cannot directly replenish the toner hopper 51 with toner.

Next, the CPU 63 detects the toner detection sensor 58.
If the user or the like replenishes toner into the toner hopper 54 by replacing the toner cartridge 60 or the like, and the detection signal S2 from the toner detection sensor 58 becomes not L, then The toner supply motor 7 is controlled by controlling the motor drive circuit 68 via the I/O 65.
0 is rotated with a duty ratio of 100%. Therefore, a large amount of toner is rapidly replenished from the toner hopper 54 to the toner hopper 51.

Next, the CPU 63 detects the toner detection sensor 57.
If the detection signal S1 from the toner detection sensor 57 is not L, the motor drive circuit 68 is controlled via the I/O 65 to start the toner replenishment motor 70. Rotate with a duty ratio of 30%. Therefore, the amount of toner supplied from the toner hopper 54 to the toner hopper 51 returns to the normal amount.

Further, when a stop signal is input from the operation display section 67 by a user's operation via the serial communication port 66, the CPU 63 ends the toner replenishment control.

Note that the present invention can be similarly applied to toner replenishing devices for image forming apparatuses other than copying machines, such as printers and facsimile machines.

[0033]

[Effect of the invention] As described above, according to the invention of claim 1,
a first toner hopper that replenishes toner to the two-component developer in the developing device; a second toner hopper that replenishes toner to the first toner hopper and has a larger capacity than the first toner hopper; A first toner detection sensor detects a toner out state in a toner hopper, a second toner detection sensor detects a toner out state in a second toner hopper, and replenishes toner to the second toner hopper. when the first toner detection sensor and the second toner detection sensor simultaneously detect the out-of-toner state based on the detection signals from the first toner detection sensor and the second toner detection sensor; Since the display means is equipped with a control means for displaying toner replenishment to the second toner hopper, the troublesome work of transferring a large amount of toner is no longer necessary, and there are fewer toner hoppers and toner detection sensors. It is possible to reduce the number of points and simplify the configuration. In addition, the two toner hoppers almost never run out of toner, making it possible to prevent a stoppage due to a toner out condition and to stably replenish toner.

According to the invention of claim 2, claim 1
In the toner replenishing device described above, the control means detects that the first toner detection sensor and the second toner detection sensor simultaneously detect an out-of-toner state based on detection signals from the first toner detection sensor and the second toner detection sensor. At times, the display means displays a message for replenishing toner to the second toner hopper, and thereafter, when the second toner detection sensor detects that there is toner, the toner is transferred from the second toner hopper to the first toner hopper. Since the first toner hopper is comprised of a control means for increasing the amount of toner supplied, not only the same effect as the invention of claim 1 can be obtained, but also the toner can be quickly replenished to the first toner hopper. The remaining amount of toner in the second toner hopper can be quickly reduced, and the state of no toner in the second toner hopper can be reliably and quickly detected. The above display can prompt the user to quickly replenish toner to the second toner hopper.

Further, according to the third aspect of the present invention, in the toner replenishing device according to the second aspect, the control means controls the first toner by the detection signals from the first toner detection sensor and the second toner detection sensor. When the detection sensor and the second toner detection sensor simultaneously detect the toner out state, the display means displays a message for replenishing toner to the second toner hopper, and then the second toner detection sensor detects the toner presence state. The present invention comprises a control means for increasing the amount of toner supplied from the second toner hopper to the first toner hopper from the time when the first toner detection sensor detects the toner presence state to the time when the first toner detection sensor detects the toner presence state. Not only can the same effect as above be obtained, but also it is possible to avoid oversupplying toner from the second toner hopper to the first toner hopper.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the invention of claim 1.

FIG. 2 is a block diagram showing the invention according to claim 2.

FIG. 3 is a block diagram showing the invention according to claim 3.

FIG. 4 is a sectional view schematically showing an example of a copying machine to which the present invention is applied.

FIG. 5 is a sectional view showing the developing device of the copying machine.

FIG. 6 is a perspective view showing the entire copying machine.

FIG. 7 is a block diagram showing the circuit configuration of the copying machine.

FIG. 8 is a flowchart showing the processing flow of the CPU in the copying machine.

FIG. 9 is a timing chart of the copying machine.

FIG. 10 is a timing chart of the copying machine.

[Explanation of symbols]

1 First toner detection sensor 2
Second toner detection sensor 3 Display means 4, 5, 6 Control means

Claims (3)

[Claims] 1. Toner replenishment for an image forming apparatus that forms a latent image on an image carrier, develops this latent image with a two-component developer using a developing device, and replenishes toner to the two-component developer in the developing device. In the apparatus, a first toner hopper supplies toner to the two-component developer in the developing device, and a second toner hopper supplies toner to the first toner hopper and has a larger capacity than the first toner hopper. a first toner detection sensor that detects an out-of-toner state in the first toner hopper; a second toner detection sensor that detects an out-of-toner state in the second toner hopper; a display means for displaying toner replenishment to the toner hopper; and a display means for displaying a display for replenishing toner to the toner hopper; A toner replenishing device comprising: a control means for causing the display means to display a message for replenishing toner to the second toner hopper when a detection sensor simultaneously detects a toner out state. 2. The toner replenishing device according to claim 1,
When the first toner detection sensor and the second toner detection sensor simultaneously detect the out-of-toner state based on the detection signals from the first toner detection sensor and the second toner detection sensor, the control means The display means displays a message for replenishing toner to the second toner hopper, and after that, when the second toner detection sensor detects a toner presence state, the first toner is removed from the second toner hopper. A toner replenishing device comprising a control means for increasing the amount of toner supplied to a hopper. 3. The toner replenishing device according to claim 2, further comprising:
When the first toner detection sensor and the second toner detection sensor simultaneously detect the out-of-toner state based on the detection signals from the first toner detection sensor and the second toner detection sensor, the control means The display means displays a message for replenishing toner to the second toner hopper, and after that, when the second toner detection sensor detects the toner presence state, the first toner detection sensor detects the toner presence state. 1. A toner replenishing device comprising: a control means for increasing an amount of toner supplied from said second toner hopper to said first toner hopper until a time when said toner replenishment device detects said second toner hopper.