JP2010217749A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent toner from flowing into a developing unit even when toner supply is stopped in continuous high-quality image forming (high-image printing). <P>SOLUTION: CPU 141 of an ID-R/W board 150 accumulates and stores the time of continuous supply of toner in an ID chip 149. At the timing when a normal toner supply operation starts, an image forming device determines whether or not the continuous supply time accumulated and stored in the ID chip 149 reaches preset continuous supply permission time, and determines whether or not the required toner supply time corresponding to the required amount of toner supply reaches preset minimum supply time. If the continuous supply time has not reached the continuous supply permission time and the required toner supply time has reached the minimum supply time, toner supply is performed. If the continuous supply time has reached the continuous supply permission time or if the required toner supply time has not reached the minimum supply time, toner supply is paused. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a printer, a copier, a facsimile machine, or at least one of these having a toner container such as a toner bottle for containing toner and a developing unit, and having no intermediate supply tank between the toner container and the developing unit. The present invention relates to an image forming apparatus such as a digital multi-function peripheral having a combination of two functions, and more particularly to a technique related to control of toner supply from a toner container to a developing unit.

In an electrophotographic image forming apparatus such as a printer, toner is consumed as printing (image formation) is repeated, so that the consumed amount is sequentially supplied to the developing unit.
In general, many toners are replenished to a developing unit with toner contained in a toner container such as a toner bottle or a toner cartridge having the toner bottle.
By the way, as an image forming apparatus using such a toner container, there is a configuration in which there is no intermediate supply tank (intermediate container) in the path between the toner container and the developing unit.
However, in the image forming apparatus having such a configuration, when high image printing (high quality image formation) continues, even if the driving of toner replenishment is stopped, a phenomenon that the toner flows into the developing unit occurs. There was a problem that led to a decline.

Therefore, it is conceivable to use the technique disclosed in Patent Document 1.
In Patent Document 1, a toner replenishment amount is acquired based on a toner consumption amount consumed by forming a toner image, and it is determined whether the toner replenishment amount exceeds or falls below a predetermined replenishment lower limit value. When the amount exceeds the lower limit of replenishment, it is determined whether the amount of toner replenishment exceeds or falls below the upper limit of replenishment that is the upper limit of the amount of toner to be replenished in one replenishment operation. A configuration is disclosed in which the toner replenishment amount is controlled to be replenished when the toner replenishment amount exceeds the upper limit value, and the toner replenishment amount is replenished when the toner replenishment amount falls below the replenishment upper limit value. ing.

However, even the one described in Patent Document 1 solves the problem that if high-image printing continues, even if driving of toner replenishment is stopped, the phenomenon of toner flowing into the developing unit occurs, leading to deterioration in the density quality of the image. Can not.
The present invention has been made in view of the above points, and an object thereof is to prevent toner from flowing into a developing unit even when toner supply is stopped when high-quality image formation (high image printing) is continued. And

  The present invention is an image forming apparatus having a configuration in which there is no intermediate supply tank in the path between the toner container and the developing unit, and having a toner supplying means for supplying toner in the toner container to the developing unit. In order to achieve this, the continuous replenishment time accumulating storage means for accumulating and storing the continuous toner replenishment time by the toner replenishing means, and the continuous replenishment time in the continuous replenishment time accumulating storage means at the timing of starting the normal toner replenishment operation. First time determination means for determining whether or not the predetermined continuous replenishment time has been reached, and the result of determination by the first time determination means, the continuous replenishment time has reached the continuous replenishment possible time In this case, a toner replenishment suspension unit that halts toner replenishment by the toner replenishing unit is provided.

A toner replenishment feedback unit that feeds back the amount of toner replenished by the toner replenishment suspension unit to the next toner replenishment by the toner replenishment unit may be provided.
Also, pixel information acquisition means for acquiring pixel information of image data for forming a toner image by the developing unit, and toner supply suspension by the toner supply suspension means based on the pixel information acquired by the pixel information acquisition means You may provide the rest time correction | amendment means which correct | amends time.

  Furthermore, a necessary replenishment time calculating means for calculating a necessary toner replenishment time corresponding to the amount of toner replenished by the toner replenishing means, and the necessary toner replenishment time calculated by the necessary replenishment time calculating means are preset. A second time determination unit for determining whether or not the minimum supply time has been reached, and the continuous supply time is determined as a result of the determination by the first time determination unit. Means for performing toner replenishment by the toner replenishment means when the possible time has not been reached and, as a result of the determination by the second time determination means, the required toner replenishment time has reached the minimum replenishment time. And the toner replenishment suspension means is determined when the required toner replenishment time has not reached the minimum replenishment time as a result of the determination by the second time determination means. It may be a means for resting the toner supply by the toner supply means.

In this case, toner density detecting means for detecting the toner density in the developing unit is provided, and the necessary replenishment time calculating means performs necessary toner replenishment by the toner replenishing means according to the detection result by the toner density detecting means. The amount may be calculated, and the toner replenishment time may be calculated based on the calculation result.
Further, there may be provided an abnormality detection means for detecting an abnormality, and a continuous replenishment time deletion means for deleting the continuous replenishment time in the continuous replenishment time accumulation storage means when an abnormality is detected by the abnormality detection means. .
Further, a continuous replenishment possible time setting means for setting the continuous replenishment possible time by an external operation signal, and a pause time setting means for setting a toner replenishment pause time by the toner replenishment suspension means by an external operation signal. It may be provided.

  According to the present invention, the continuous replenishment time of toner by the toner replenishing means is accumulated and stored, and the accumulated replenishment time reaches the preset continuous replenishable time at the timing of starting the normal toner replenishment operation. If the continuous replenishment time reaches the continuous replenishable time, the toner replenishment is suspended to stop toner replenishment when high-quality image formation continues. The toner can be prevented from flowing into the developing unit. Therefore, the density quality of the image can be maintained.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a toner supply device that supplies toner from a toner cartridge 30 to the developing device 11 in FIG. 1. FIG. 3 is a layout diagram showing a positional relationship among the toner cartridge 30, the developing device 11, and the toner transport path in FIG. 1 when the toner supply device shown in FIG. FIG. 2 is a block diagram illustrating a configuration example of a control system of the image forming apparatus illustrated in FIG. 1.

It is a block diagram which shows the structural example of the ID-R / W board 150 provided in the setting part 9 of FIG. FIG. 6 is a flowchart showing an example of processing related to toner replenishment by a CPU 141 of the ID-R / W board 150 shown in FIG. 5. FIG. 7 is a flowchart showing an example of a subroutine for toner replenishment processing in step S <b> 2 of FIG. 6. FIG. 5 is a layout diagram illustrating only a portion for performing settings relating to toner supply in the operation unit 110 of FIG. 4.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.
This image forming apparatus is an indirect transfer tandem image forming apparatus, and is an example configured as a printer. The mechanical configuration of the image forming apparatus is a known one.

  In the apparatus main body 1 of the image forming apparatus shown here, four image forming units 2 (2K) that respectively perform image formation for each color of K (black), M (magenta), C (cyan), and Y (yellow). , 2M, 2C, 2Y). An intermediate transfer member 3 made of an endless belt is disposed facing each of the image forming units 2, and the intermediate transfer member 3 is wound around a plurality of support rollers and travels in the direction of arrow A. Each image forming unit 2 applies a K toner image, an M toner image, a C toner image, and a C toner image to the photoreceptor 10 (10K, 10M, 10C, 10Y), which is an image carrier, based on an electrophotographic method known per se. And Y toner images are respectively formed, and these toner images are electrostatically transferred by being sequentially superimposed on the intermediate transfer body 3.

  A sheet feeding device 4 is arranged at the lower part in the image forming apparatus main body 1, and a sheet (or other print medium) sent out from the sheet feeding device 4 is conveyed along a conveying path and is passed through a registration roller 5. Then, it is fed between the intermediate transfer body 3 and the transfer device 6. When the sheet passes between the intermediate transfer member 3 and the transfer device 6, the toner images superimposed on the intermediate transfer member 3 are transferred onto the sheet. Next, the sheet passes through the fixing device 7, and at this time, the image on the sheet is fixed to the sheet by the action of heat and pressure. The sheet that has passed through the fixing device 7 is discharged to the discharge unit 8.

Between the discharge unit 8 of the image forming apparatus main body 1 and the intermediate transfer member 3, a set unit 9 to which four toner cartridges 30 (30K, 30M, 30C, 30Y) are mounted is provided.
Each of the toner cartridges 30 includes a toner bottle (toner container) containing toner to be supplied to the developing device (developing unit) 11 (11K, 11M, 11C, 11Y) of each image forming unit 2. It is detachably mounted.

FIG. 2 is a diagram illustrating a configuration of a toner supply device that supplies toner from the toner cartridge 30 to the developing device 11 in FIG. 1.
In FIG. 2, a toner image is formed on the photosensitive member 10 shown in FIG. 1 by a developing device 11 of an image forming apparatus using a conventionally known electrophotographic method. The developing device 11 includes a powder pump 20, and the toner of the toner cartridge 30 is supplied into the developing container 11 a through a tube 25 that is a toner transfer member by the operation of the powder pump 20. The tube 25 communicates with the inside of the toner cartridge 30 through the nozzle 31.

  As the powder pump 20, a suction type uniaxial eccentric powder pump (commonly called “Mono pump”) or the like is used. The structure is composed of a rotor 21 formed in a screw shape eccentric with a material having rigidity such as metal, a stator 22 in which two screw-shaped holes are formed by rubber material and fixedly installed, and these are wrapped and powdered. The housing 23 is formed of a resin material or the like that forms a body transfer path. Due to the rotation of the rotor 21, a strong self-priming force (suction pressure) is generated in the pump, and the toner can be sucked from the toner cartridge 30.

  The tube 25 is a tube having an inner diameter of 4 to 10 mm, and is made of a flexible and excellent toner resistance rubber material (ex polyurethane, nitrile, EPDM, silicon, etc.) or plastic material (polyethylene, nylon, etc.). It is valid. The sucked toner falls into the developing container 11a from the toner introduction hole 12 provided in a part of the developing device 11, and is further transferred to the developing unit by a stirring screw (not shown). When the two-component development method is used, the toner (sucked toner) replenished during this transfer process is agitated and mixed with the developer in the developing container 11a, so that a uniform agent concentration and an appropriate charge amount are obtained.

  The toner cartridge 30 requires that the toner is always present in the vicinity of the toner suction portion 29 indicated by hatching in order to suck and convey the toner by the powder pump 20. Some containers have a spiral projection on the inner wall of the container and convey toner to the tip of the container by rotation of the cartridge body. The configuration for replenishing toner by rotating the cartridge body will be described later with reference to FIG.

  In such a toner supply device, conventionally, a change in the mixing ratio between the toner and the carrier in the developing container 11a is detected based on a magnetic permeability detector (not shown) provided in a part of the developing device 11, and the amount of toner is small. Is detected, the drive shaft 24 of the powder pump 20 is rotationally driven to operate the powder pump 20, and when the toner transferred into the developing container 11a by the powder pump 20 exceeds a certain amount, A method can be used in which the drive is shut off by the output signal of the magnetic permeability detector and the operation of the powder pump 20 is stopped.

FIG. 3 is a layout diagram showing a positional relationship among the toner cartridge 30, the developing device 11, and the toner transport path of FIG. 1 when the toner supply device shown in FIG. 2 is not used.
In the example of FIG. 3, each toner cartridge 30 and each developing device 11 are connected by a toner transport path 15 (15K, 15M, 15C, 15Y), and the main body (toner bottle) of each toner cartridge 30 is illustrated. The toner is transported to each developing device 11 and replenished by being rotated by a toner replenishing motor, which is a power source that does not.

FIG. 4 is a block diagram illustrating a configuration example of a control system of the image forming apparatus illustrated in FIG.
The image forming apparatus includes an operation unit 110, an image processing unit 132, a hard disk device (HDD) 134, a network control unit (NCU) 139, and a facsimile control unit (FCU) 140 centering on an engine control board (engine control unit) 120. , Various sensors 137 and a load 138 are connected.

The engine control board 120 includes a CPU 121, a ROM 122, a RAM 123, a nonvolatile RAM 124, and an I / O control unit 125 connected to the CPU 121 via a data bus and an address bus.
The ROM 122 is a read-only memory (storage means) that stores a program code of a program executed by the CPU 121.

The CPU 121 is a central processing unit that executes a program in the ROM 122 (or a program in the HDD 134) while using the RAM 123 as a work area, and comprehensively controls the entire image forming apparatus including the operation unit 110. Therefore, the CPU 121 can function as a continuous replenishable time setting unit and a pause time setting unit according to the present invention.
The nonvolatile RAM 124 is a memory that stores and saves data and various setting values necessary when the CPU 121 executes a program.

The I / O control unit 125 outputs output signals of various sensors 137 used for control of operations related to image formation and paper conveyance described with reference to FIG. 1 (excluding processing related to toner supply described with reference to FIG. 2 or FIG. 3). It controls the output of signals to the load 138 such as an input or a motor.
The HDD 134 is a large-capacity storage unit that is connected to the CPU 121 via the HDD controller 131 and controlled by the CPU 121.

The image processing unit 132 is a circuit using an ASIC (Application Specific Integrated Circuit) that performs image processing on image data. From this image processing unit 132, it is possible to acquire pixel information of image data that is information of pixels constituting the image data.
The image processing unit 132 includes a reading unit 135 such as a scanner for reading an image of a document, and a laser diode or LED or the like based on the image data to be charged in advance by a surface of a photosensitive member (not shown). ) Is connected to a writing unit 136 that writes an electrostatic image (electrostatic latent image), and an image RAM 133 that temporarily stores image data. Note that the above-described toner image is obtained by developing the electrostatic image by the adhesion of the toner.

Image data read by the reading unit 135 is input to the image processing unit 132, and image data for writing is input from the image processing unit 132 to the writing unit 136. The image data temporarily stored in the image RAM 133 is also read by the image processing unit 132, or the image data read by the reading unit 135 is temporarily stored in the image RAM 133.
The image processing unit 132 is also connected to the HDD controller 131, and image data stored in the HDD 134 is read out or image data subjected to image processing is stored in the HDD 134.

The operation unit 110 has various operation keys (also referred to as operation switches or operation buttons) for performing various settings and requests to the image forming apparatus by a user operation, and an operation unit having a display such as an LCD or a CRT. It is.
The toner bottle used in this embodiment is equipped with an ID chip (nonvolatile memory-RFID chip) 149 shown in FIG. 5 for each color, and the continuous replenishment time and toner replenishment time described later from the CPU 121 of the engine control board 120 are mounted. Data can be read and written including downtime. The toner bottle is usually a toner cartridge 30 filled with toner in combination with a cap. When the set unit 9 is provided with a control board (hereinafter referred to as “ID-R / W board”) 150 for reading and writing with the ID chip 149, the toner cartridge 30 (toner bottle) is set in the set unit 9. The ID chip 149 is communicable.

FIG. 5 is a block diagram illustrating a configuration example of the ID-R / W board 150.
The ID-R / W board 150 includes a CPU 141, a ROM 142, a RAM 143, a nonvolatile RAM 144, and an I / O control unit 145 connected to the CPU 141 via a data bus and an address bus.
The ROM 142 is a read-only memory (storage means) that stores a program code of a program executed by the CPU 141.

  The CPU 141 is a central processing unit that performs processing related to reading and writing of data to the ID chip 149 and toner supply by executing a program in the ROM 142 while using the RAM 143 as a work area. Therefore, the CPU 141 includes toner replenishing means, continuous replenishment time accumulation storage means, first time determination means, toner replenishment suspension means, toner replenishment feedback means, pixel information acquisition means, rest time correction means, and necessary replenishment means. Functions as a time calculation means, a second time determination means, a toner concentration detection means, an abnormality detection means, and a continuous replenishment time deletion means can be achieved.

The nonvolatile RAM 144 is a memory that stores and saves data necessary when the CPU 141 executes a program.
The I / O control unit 145 controls input of an output signal of a toner concentration detection sensor 147 related to toner replenishment provided in the developing device 11 and output of a signal to a load 148 such as a motor or a pump.
The toner concentration detection sensor 147 detects the toner concentration in the developing device 11 (actually in the developing container 11a). Note that the magnetic permeability detector described above may be used instead of the toner concentration detection sensor 147.

  The ID chip 149 is connected so as to be able to communicate with each other wirelessly, and transmits and receives information via a data bus and an address bus. Therefore, an I / O control unit (not shown) for performing wireless communication is provided. The configuration related to wireless communication between the ID chip 149 and the ID-R / W board 150 is well-known (for example, Japanese Patent Application Laid-Open No. 2007-148006). Further, in this embodiment, the communication between the ID chip 149 and the set unit 9 is performed using radio, but it is also possible to configure to connect directly to the data bus and the address bus using a connector. .

  FIG. 6 is a flowchart illustrating an example of processing related to toner replenishment by the CPU 141 of the ID-R / W board 150 illustrated in FIG. For convenience of explanation, processing related to toner replenishment from the toner cartridge 30K to the developing device 11K during monochrome image formation (printing) will be described. For example, when full-color image formation is performed, the other toner cartridges 30M, 30M, Processing related to toner replenishment from 30C, 30Y to the developing devices 11M, 11C, 11Y is similarly performed.

  The CPU 141 of the ID-R / W board 150 is triggered by the output of image data (image output signal) from the image processing unit 132 to the writing unit 136 in FIG. 6 starts processing related to toner replenishment from the toner cartridge 30K to the developing device 11K. First, the process proceeds to step S1, and the toner concentration detection sensor 147 is used to detect (detect) the toner concentration in the developing device 11K. A necessary toner replenishment amount is calculated (calculated) according to the detection result. At this time, if the carry-over replenishment amount described later in the ID chip 149 is not “0”, the carry-over replenishment amount is added.

Next, the process proceeds to step S2 to perform toner replenishment processing.
That is, the calculated necessary toner replenishment amount is converted into time (calculated necessary toner replenishment time based on the calculation result of necessary toner replenishment amount), and the K toner replenishment motor in the load 138 is driven. Thus, toner is supplied from the toner cartridge 30K to the developing device 11K. Here, the toner replenishment motor includes the powder pump 20 of FIG.

FIG. 7 is a flowchart showing an example of a subroutine for toner supply processing in step S2 of FIG.
First, the CPU 141 of the ID-R / W board 150 proceeds to step S11 and determines whether or not the continuous replenishment time in the ID chip 149 is less than the preset continuous replenishment possible time (whether the continuous replenishment possible time has been reached). Determine. At this time, it is also determined whether or not the necessary toner replenishment time previously converted (calculated) has reached a preset minimum replenishment time. At the start of printing, the continuous supply time in the ID chip 149 is “0”. The minimum supply time is set in advance according to the characteristics of the toner supply motor.

  As a result of each determination, when the continuous replenishment time in the ID chip 149 is less than the continuous replenishment possible time (not reaching the continuous replenishment possible time), the necessary toner replenishment time calculated earlier is the minimum replenishment time. In step S12, the necessary toner replenishment time is added (accumulated) to the continuous replenishment time in the ID chip 149. Then, the process proceeds to step S13. By starting driving of the replenishing motor, toner replenishment from the toner cartridge 30K to the developing device 11K is started. The continuous replenishment time in the ID chip 149 is reset (deleted) to “0” when toner replenishment by driving of the K toner replenishment motor is not continuously performed, that is, when the toner replenishment is stopped.

Thereafter, the process proceeds to step S14, where it is determined whether or not the necessary toner replenishment time calculated earlier is less than the continuous replenishment possible time.
If it is less than the continuous replenishment time, the process proceeds to step S18, where the presence or absence of the next page of image data from the image processing unit 132 to the writing unit 136 is checked. If the image data is present, the process returns to step S1 in FIG. 6 to detect the toner density in the developing device 11K using the toner density detection sensor 147, and calculates (calculates) a necessary toner supply amount according to the detection result. . At this time, if the carry-over supply amount in the ID chip 149 is not “0”, the carry-over supply amount is added.

Next, the process proceeds to step S2. And it progresses to step S11 of FIG. 7 again, and it is determined whether the continuous supply time in ID chip 149 is less than the continuous supply possible time. At this time, it is also determined whether or not the necessary toner replenishment time calculated previously has reached the minimum replenishment time.
As a result of each determination, if the continuous replenishment time in the ID chip 149 is less than the continuous replenishment possible time, and if the necessary toner replenishment time has reached the minimum replenishment time, the process proceeds to step S12 and necessary. After the toner replenishment time is added to the continuous replenishment time in the ID chip 149, the process proceeds to step S13, and the driving of the toner supply motor for K for the added toner replenishment time is started, so that the toner cartridge 30K to the developing device 11K. Toner replenishment is started. If the K toner supply motor has already been driven, the drive continues.

Then, it progresses to step S14 and performs the same process as the above-mentioned.
On the other hand, if the result of determination in step S11 is that the continuous replenishment time in the ID chip 149 has reached the continuous replenishment possible time, or if the required toner replenishment time has not reached the minimum replenishment time, the process proceeds to step S15. The carry-over supply amount in the ID chip 149 is updated. That is, the necessary toner supply amount is added to the carry-over supply amount. As a result, the toner replenishment amount corresponding to the pause is fed back to the next toner replenishment. Note that the carry-over supply amount in the ID chip 149 may be added to the necessary toner supply time instead of the carry-over correction time. In this case, the carry-over replenishment amount is not added when calculating the necessary toner replenishment amount in step S1 of FIG. When calculating the necessary toner replenishment time in step S2, the carry-over replenishment time is added.

  In step S15, toner replenishment is carried over. In next step S16, the toner replenishment pause time is set in accordance with the average value of the pixel information (for example, the ratio of black pixels) of the image data of each page from the start of printing to the present. It can also be corrected. Note that the pixel information of the image data of each page is sequentially stored in the ID chip 149, whereby the average value (pixel average value) of the pixel information can be calculated.

Table 1 shows an example of the relationship between each pixel average value and the toner replenishment pause time corrected according to the pixel average value.
In this example, the preset toner replenishment pause time is 100 (ms), and when the pixel average value is 100%, the toner replenishment pause time remains 100 (ms). A value of 50% indicates that the toner supply pause time is corrected to 50 (ms). The toner replenishment pause time can be set by user operation, which will be described in detail later.

Returning to the processing of FIG. 7, in the next step S17, the toner supply from the toner cartridge 30K to the developing device 11K is stopped by stopping (stopping) the driving of the K toner supply motor.
Thereafter, the operations shown in FIGS. 6 and 7 are repeatedly performed between the respective print pages, so that continuous driving of toner replenishment is possible within a range not exceeding the threshold value.
If an abnormality such as a paper jam occurs in the image forming apparatus, the abnormality can be detected by a corresponding sensor or the like. In this case, the continuous replenishment time in the ID chip 149 is set to “0”. It may be reset.

FIG. 8 is a layout diagram showing only a portion for performing settings relating to toner supply in the operation unit 110 of FIG.
By operating an operation key (not shown) of the operation unit 110, the user displays a setting screen related to toner supply as shown in FIG. 8 on the display 110a, and then operates the numeric keypad 110b and other operation keys. Thus, the continuous replenishment possible time and the toner replenishment rest time can be respectively input and set. The set continuous replenishment time and toner replenishment pause time are stored and held in the ID chip 149 as described above.

  As described above, the cumulative toner replenishment time is cumulatively stored, and at the timing when the normal toner replenishment operation starts, it is determined whether or not the cumulatively stored continuous replenishment time has reached a preset continuous replenishable time. When the continuous replenishment time reaches the continuous replenishment possible time, the toner replenishment is suspended, so that when the high image printing (high-quality image formation) continues, the toner remains in the developing unit even if the toner replenishment is stopped. It can be prevented from flowing into (developing device). Therefore, the density quality of the image can be maintained.

Further, if the toner replenishment amount corresponding to the pause is fed back to the next toner replenishment, the image density quality can be reliably maintained.
Further, by acquiring from the image processing unit 132 pixel information of image data for forming a toner image, that is, image data input to the writing unit 136 in FIG. The density quality of the image can be more reliably maintained by correcting the rest time of the toner supply based on the information.

  Furthermore, since the toner replenishment amount varies when the toner replenishment amount is less than the minimum replenishment amount, it is determined whether the necessary toner replenishment time corresponding to the necessary toner replenishment amount has reached a preset minimum replenishment time. When the continuous replenishment time has not reached the continuous replenishment time and the required toner replenishment time has reached the minimum replenishment time, toner replenishment is executed, but the continuous replenishment time can be continuously replenished When the time has reached or the required toner replenishment time has not reached the minimum replenishment time, if the toner replenishment is stopped, the toner replenishment amount will not vary, and stable toner replenishment will be possible. Become. Therefore, the density quality of the image can be maintained more reliably.

In addition, the toner concentration in the developing unit is detected, the required amount of toner replenishment is calculated according to the detection result, and the toner replenishment time is calculated based on the calculation result, thereby ensuring the necessary toner replenishment time. Can be obtained.
Furthermore, when an abnormality occurs in the apparatus (image forming apparatus) and the abnormality is detected, the continuous replenishment time that has been accumulated and stored is reset to “0” to prevent toner oversupply and insufficient replenishment. You can also.
Furthermore, if the parameters such as the continuous replenishment time and the toner rest time can be set to be changeable, it is possible to cope with the machine body variation by changing the parameters.

  Although the embodiments of the present invention have been specifically described above, the present invention is not limited to these embodiments, and these embodiments depart from the spirit and scope of the present invention. And can be changed or modified.

  As is apparent from the above description, according to the present invention, when high image printing continues, it is possible to prevent toner from flowing into the developing unit even if toner supply is stopped. Can be maintained. By utilizing this invention, an image forming apparatus capable of realizing high image quality can be provided.

1: Image forming apparatus main body 2 (2K, 2M, 2C, 2Y): Image forming unit 3: Intermediate transfer member 9: Set portion 10 (10K, 10M, 10C, 10Y): Photoconductor 11 (11K, 11M, 11C, 11Y): developing device 11a: developing container 20: powder pump 30 (30K, 30M, 30C, 30Y): toner cartridge 110: operation unit 110a: display 110b: numeric keypad 120: engine control board 121, 141: CPU 122, 142: ROM
123, 143: RAM 124, 144: Non-volatile RAM 149: ID chip 150: ID-R / W board

JP 2005-77622 A

Claims (7)

An image forming apparatus having a configuration in which an intermediate supply tank is not provided in a path between a toner container such as a toner bottle for storing toner and a development unit, and having a toner supply means for supplying toner in the toner container to the development unit,
Continuous replenishment time accumulating storage means for accumulating and storing the continuous replenishment time of toner by the toner replenishing means;
First time determining means for determining whether or not the continuous replenishment time in the continuous replenishment time accumulation storage means has reached a preset continuous replenishable time at a timing at which a normal toner replenishing operation is started;
And a toner replenishment suspension unit for halting toner replenishment by the toner replenishment unit when the continuous replenishment time reaches the continuous replenishment possible time as a result of the determination by the first time determination unit. Image forming apparatus. The image forming apparatus according to claim 1.
An image forming apparatus, comprising: a toner replenishment feedback unit that feeds back a toner replenishment amount that is suspended by the toner replenishment suspension unit to a next toner replenishment by the toner replenishment unit. The image forming apparatus according to claim 1, wherein
Pixel information acquisition means for acquiring pixel information of image data for forming a toner image by the developing unit;
An image forming apparatus comprising: a pause time correcting means for correcting a pause time of toner supply by the toner supply pause means based on pixel information acquired by the pixel information acquisition means. The image forming apparatus according to any one of claims 1 to 3,
A necessary replenishment time calculating means for calculating a necessary toner replenishment time corresponding to the amount of toner replenishment required by the toner replenishing means;
Second time determining means for determining whether or not the necessary toner supply time calculated by the required supply time calculating means has reached a preset minimum supply time;
The toner replenishing means is the case where the continuous replenishment time has not reached the continuous replenishment possible time as a result of the determination by the first time determination means, and the result of the determination by the second time determination means is the required Means for executing toner replenishment by the toner replenishing means when a short toner replenishment time reaches the minimum replenishment time;
The toner replenishment suspending means is a means for suspending toner replenishment by the toner replenishing means even when the necessary toner replenishment time has not reached the minimum replenishment time as a result of the determination by the second time determining means. An image forming apparatus, comprising: The image forming apparatus according to claim 4.
Providing a toner concentration detecting means for detecting a toner concentration in the developing unit;
The necessary replenishment time calculating means calculates a required amount of toner replenishment by the toner replenishing means in accordance with a detection result by the toner density detecting means, and calculates a toner replenishment time based on the calculation result. Image forming apparatus. The image forming apparatus according to any one of claims 1 to 5,
An anomaly detecting means for detecting an anomaly;
An image forming apparatus comprising: a continuous replenishment time deletion unit that deletes a continuous replenishment time in the continuous replenishment time accumulation storage unit when an abnormality is detected by the abnormality detection unit. The image forming apparatus according to any one of claims 1 to 5,
A continuous replenishable time setting means for setting the continuous replenishable time by an external operation signal;
An image forming apparatus comprising: a rest time setting means for setting a rest time for toner replenishment by the toner replenishment suspension means according to an operation signal from the outside.

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