JP2005227710A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which the high productivity of image formation and the extension of the life of the apparatus are achieved by omitting a developer supply operation when unnecessary. <P>SOLUTION: The image forming apparatus includes: a developing device which develops an electrostatic latent image on an image carrier with developer; a developer storage container storing the developer; a developer supply device which supplies developer from the developer storage container to the developing device; and a control means for controlling the operation of the image forming apparatus. The control means controls the operation of the image forming apparatus based upon the state of the developing device and the state of the developer storage container. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus using an electrophotographic system or an electrostatic transfer system, such as a copying machine, a printer, a facsimile machine, or a multifunction machine of these, and more particularly to an improvement in operation.

JP 2001-305845 A JP-A-62-105173

  Conventionally, image forming apparatuses such as copying machines and printers using an electrophotographic system and an electrostatic transfer system are widely known. Some image forming apparatuses include a developing device, a developer container, and a developer replenishing device that replenishes the developer from the developer container to the developing device. Here, the developer container is filled with the developer in a new state, but the amount of the developer inside gradually decreases with the aging of the image forming apparatus, and eventually becomes empty. (Usually) replaced with a new developer container.

  At this time, in order to detect that the developer container is empty, the developer is indirectly detected by the developer concentration detecting means provided in the developing device (without providing a special sensor in the developer container). The present applicant has already proposed Patent Document 1 as a technique for detecting the amount of developer in the container. On the other hand, Patent Document 2 discloses a technique for interrupting printing and supplying developer from a developer container to a developing device when the developer concentration is reduced.

  However, the technique disclosed in Patent Document 1 erroneously detects that the developer container is “empty” when the developer concentration temporarily decreases due to continuous printing with high image density. There is a risk of it. On the other hand, in the technique disclosed in Patent Document 2, a developer is present in the developer container in the first place because printing is interrupted and the developer is replenished regardless of the presence or absence of the developer in the developer container. If not, the productivity of image formation may be impaired, and the life of the developing device and the image forming apparatus (photoconductor, etc.) may be adversely affected.

  The present invention has been made in view of such technical problems, and an object of the present invention is to improve the productivity of image formation and extend the life of the image forming apparatus by omitting useless developer replenishment operations. An object of the present invention is to provide an image forming apparatus capable of performing the above.

  That is, the present invention provides a developing device that develops an electrostatic latent image on an image bearing member with a developer, a developer containing device that contains the developer, and replenishing the developer from the developer containing device to the developing device. A developer replenishing device and a control unit that controls the operation of the image forming apparatus are provided. The control unit controls the operation of the image forming apparatus based on the status of the developing device and the status of the developer container. It is something to control. The developing device includes first detecting means for detecting the concentration of the developer in the developing device, and the control means is configured to detect the developer concentration based on the developer concentration detected by the first detecting means. The situation can be judged. On the other hand, the developer container includes second detection means for detecting the amount of developer in the developer container, and the control means is based on the developer amount detected by the second detection means. Thus, the status of the developer supply device can be determined. The second detection unit may include a storage unit that stores a usage history of the developer container, and may detect the amount of developer in the developer container based on the usage history.

  Further, when the concentration of the developer in the developing device becomes lower than a predetermined concentration, the control unit controls the developer replenishing device so as to replenish the developer from the developer container to the developing device. Can do. Further, even when the developer concentration in the developing device is lower than a predetermined concentration, when the amount of the developer in the developer supply device is less than the predetermined amount, the control means The developer replenishing device can be controlled so as not to replenish the developer from the container to the developing device, the image formation can be stopped, and it is determined that the inside of the developer supplying device is empty. The interface means can also notify the user that the amount of the developer in the developer supply device is less than a predetermined amount (provided with an interface means for notifying the user of the status of the image forming apparatus). Can also be controlled. In other words, when the concentration of the developer in the developing device is lower than a predetermined concentration and the amount of the developer in the developer feeder is larger than the predetermined amount, the control means The developer supply device can be controlled so as to supply the developer to the developing device.

  Further, when the concentration of the developer in the developing device is lower than a predetermined concentration and the amount of the developer in the developer supply device is larger than a predetermined amount, the control means is connected to the developer container. The developer replenishing device is controlled so that the developer is replenished to the developing device, and if the developer concentration in the developing device is low even when the developer is replenished, the developer is supplied from the developer container. The developer replenishing device can be controlled so that the developer is not replenished to the device, it can be determined that the image forming device is out of order, or an interface for notifying the user of the status of the image forming device It is also possible to control the interface means so as to notify the user that the image forming apparatus is out of order.

  The developer can be a two-component developer containing toner and carrier. In this case, the developer container is filled with toner and carrier, and the developer concentration detecting means is a two-component developer. The toner density can be detected.

  As described above, according to the present invention, it is possible to provide an image forming apparatus capable of improving the productivity of image formation and extending the life of the image forming apparatus by omitting useless developer replenishing operation. .

  FIG. 1 shows a color printer 1 as an image forming apparatus according to an embodiment of the present invention.

  The color printer 1 includes yellow (Y) and magenta (M) individually formed by four image forming units 10Y, 10M, 10C, and 10K based on image information input from an external connection device (such as a personal computer) (not shown). ), Cyan (C), and black (K) toner images are primarily transferred so as to be superimposed on the surface of the intermediate transfer belt 21 of the intermediate transfer mechanism 20, and then the intermediate transfer belt 21 is used as a recording medium. By performing secondary transfer to the recording paper P side, a so-called full-color image can be formed.

  Each of the image forming units 10 forms the above-described four color toner images by an electrophotographic process, and is arranged in a horizontal state at a substantially central portion of the image forming apparatus main body 1. Has been. Each image forming unit 10 basically has a photosensitive drum 11 as an image carrier that is rotationally driven at a predetermined speed in the direction of arrow A, and a roll that uniformly charges the surface of the photosensitive drum 11. Type charging device 12, ROS 13 as a latent image forming device that forms an electrostatic latent image by exposing a light image corresponding to image information to the surface of photosensitive drum 11 after charging, and two electrostatic latent images. The developing device 14 for developing with toner of a predetermined color in the component developer G, the roll type transfer device 15 for transferring the toner image formed by the development to the intermediate transfer belt 21, and the surface of the photosensitive drum 11 are cleaned. A drum cleaner 16 is similarly provided. Each image forming unit 10 is configured to be detachable from the color printer 1 as a process cartridge PC.

  Among these, the charging device 12 is applied with a charging voltage for charging the surface of the photosensitive layer of the photosensitive drum 11 from a power supply device (not shown). The ROS 13 emits laser beams LB-Y, LB-M, LB-C, and LB-K emitted from four semiconductor lasers (not shown) according to image signals separated for each color through a predetermined optical system. After the rotary polygon mirror 17 is irradiated and deflected and scanned, scanning exposure is performed obliquely from below on each of the opposing photosensitive drums 11 via a plurality of reflection mirrors (not shown).

  Reference numeral 18 in the drawing is a transparent window for transmitting and emitting each laser beam LB from the housing sealed box 13a. Each developing device 14 is a two-component developing type developing device that performs development using a two-component developer G composed of a non-magnetic toner of each color component and a magnetic carrier, and has a configuration as described later. is there. In addition, each of the developing devices 14 includes a developer replenishing device (70), which will be described later, from a detachable and replaceable toner cartridge 19Y, 19M, 19C, 19K as a developer container that contains replenishing toner and carrier. The toner and carrier are replenished in appropriate amounts. Further, a primary transfer bias having a polarity opposite to the charging polarity of the toner image on the photosensitive drum 11 is applied to the transfer device 15 (transfer bias roll) from a bias power source (not shown).

In each of the image forming units 10, the surface of the rotating photosensitive drum 11 is charged to a predetermined charging potential by the charging device 12, and then the charging surface corresponds to an image signal color-separated from the ROS 13. When the laser beam LB is scanned and exposed, an electrostatic latent image having a predetermined latent image potential is written, and then the latent image is supplied from the developing device 14 under a state where a developing bias is applied. The two-component developer G is developed with toner of each color to form a toner image. Finally, the toner image is electrostatically sequentially primary on the surface of the intermediate transfer belt 21 passing between the photosensitive drum 11 and the transfer device 15. It is designed to be transcribed. Further, the surface of the photosensitive drum 11 after the transfer is cleaned by a blade of a drum cleaner 16 or the like.

Further, as shown in FIG. 1, the intermediate transfer mechanism 20 stretches an endless intermediate transfer belt 21 on a plurality of rolls including a secondary transfer backup roll 22 and a drive roll 23, and drives the intermediate transfer belt 21. The roll 23 is rotated in the direction of arrow B by the rotational power of the roll 23. In addition, the transfer device 15 is disposed at a position on the inner peripheral surface of the intermediate transfer belt 21 opposite to the position where the photosensitive drum 11 comes into contact with the photosensitive drum 11 so that the belt 21 is pressed against the photosensitive drum 11. Each primary transfer portion is configured. Reference numeral 24 in FIG. 1 denotes a belt cleaner that cleans the surface of the intermediate transfer belt 21. In addition, around the intermediate transfer belt 21, a belt home position detection device for detecting a belt home mark formed at the belt side end, and a direction orthogonal to the belt rotation direction B at the belt one side end position. A belt walk detection device for detecting a deviation (a deviation or meandering) is provided.

  Further, a secondary transfer roll 30 that presses the intermediate transfer belt 21 against the roll 22 is disposed at a position facing the backup roll 22, and the backup roll 22 has a bias power source (not shown) on the belt 21. A secondary transfer bias having the same polarity as the charging polarity of the toner image is supplied, thereby constituting a secondary transfer portion. Reference numeral 32 in the drawing is a roll cleaner that cleans the surface of the secondary transfer roll 30.

  The toner image transferred (multiple) to the intermediate transfer belt 21 of the intermediate transfer mechanism 20 is opposed to the secondary transfer roll 30 that is arranged to face the backup roll 22 as the belt 21 rotates. It is conveyed to the secondary transfer section. Then, the toner image on the intermediate transfer belt 21 is sent out from the paper storage tray 40 in accordance with the image formation and secondary transfer timing of the toner image, and is fed through a paper feed path in which a roll 41, a resist roll 42, and the like are arranged. The recording sheet P having a predetermined size conveyed to the next transfer portion (between the intermediate transfer belt 21 and the secondary transfer roll 30) is electrostatically subjected to secondary transfer. The residual toner remaining without being transferred to the intermediate transfer belt 21 after the secondary transfer is cleaned and removed by the belt cleaner 24. 1 indicates the conveyance path of the recording paper P.

  Subsequently, the recording paper P onto which the toner image has been transferred from the intermediate transfer belt 21 is naturally peeled off from the intermediate transfer belt 21 portion in the secondary transfer portion, and then sent to the roll nip type fixing device 45, and the fixing device. The toner image is heat-fixed by passing through a fixing nip formed by a heating roll 46 and a pressure roll 47 at 45. Then, the recording paper P after the fixing process is completed is discharged out of the apparatus main body 1 (paper discharge portion) through a paper discharge path in which a discharge roll 48 and the like are provided.

  Through this process, a color image is formed on the recording paper P by this color printer. Incidentally, in this printer, for example, it is possible to form a black and white image on the recording paper P by operating only the black image forming unit 10K among the four image forming units.

  Further, the developing device 14 and the developer replenishing device 70 used in each image forming unit 10 in this color printer are configured as follows.

2 to 4, the developing device 14 includes a developing device housing 50, a developing roll 51 disposed on the photosensitive drum 11 side of the housing 50, and a rear lower side of the developing roll 51. Augers 52 and 53 as developer agitating and conveying means, a paddle 54 as a developer supplying means for supplying the two-component developer G agitated and conveyed by the augers 52 and 53 to the developing roll 51 side, and The main part is composed of a trimmer 55 that regulates the layer thickness of the two-component developer G that is supplied and conveyed in a state where a magnetic brush is formed from the paddle 54 to the developing roll 51. The paddle 54 is not particularly required when the developer G can be supplied from the auger 52 to the developing roll 51.

  Among these, the developing roll 51 includes a cylindrical sleep made of a nonmagnetic conductive material and a magnet roll disposed in the hollow of the sleeve. A predetermined developing bias (for example, a voltage in which alternating current is superimposed on direct current) is applied to the sleeve from a developing bias power source (not shown). Further, a partition plate 56 is provided at a portion between the augers 52 and 53 of the housing 50 in a state where passages 57a and 57b are formed at both ends thereof. 3 and 4, reference numeral 50 a denotes a developer receiving portion that receives the developer replenished from the developer replenishing device 70, and 50 b denotes so-called trickle development in which the deteriorated developer is discharged and collected so as to overflow little by little. The developer discharge part of a system is shown.

  In such a developing device 14, the two-component developer G accommodated in the housing 50 is circulated and conveyed while passing through the passages 72 a and 72 b while being agitated by the rotational drive of the augers 52 and 53. At this time, the toner of the developer G is frictionally charged to a predetermined polarity by being mixed and stirred with the carrier. Subsequently, in the developing device 14, the developer G is supplied to the side of the developing roll 51 via the paddle 54 and is carried in a state where a magnetic brush is formed, and the layer thickness passes through a position immediately below the trimmer 55 to be predetermined. The thickness is regulated. Then, when the developer G after the regulation of the layer thickness is conveyed to the developing area facing the photosensitive drum 11 by the rotation of the developing roll 51, the developing electric field formed by the developing bias applied to the developing roll 14 is applied. Only the toner adheres electrostatically to the latent image portion of the photosensitive drum 11 so that development is performed.

  Further, the developing device 14 is provided with a magnetic sensor 60 as a toner concentration detecting means (first detecting means) for detecting the toner concentration (TC) of the two-component developer G accommodated in the housing 50. ing.

  The magnetic sensor 60 is of a type that detects a toner concentration by detecting a change in magnetic permeability due to the developer G in the housing 50, and has a main body portion 61 and a sensor portion 62 that protrudes from the main body portion 61. The developing device housing 50 is attached to the outer wall portion on the side where the auger 53 is located. Specifically, the sensor portion 62 (detection surface 62a) is attached so as to be exposed on the same surface as the inner surface 50c of the housing. According to the magnetic sensor 60, an analog output voltage corresponding to a change in magnetic permeability due to the two-component developer and a change in toner density can be obtained as a sensor output value. That is, when the toner is sufficient and the toner concentration TC is high, a small output voltage can be obtained. Conversely, when the toner is low and the toner concentration TC is low, a large output voltage can be obtained. The sensor output value of the magnetic sensor 60 is input to a control device (80) to be described later and used for required control processing.

  On the other hand, the developer replenishing device 70 is of a type that replenishes the developing device 14 with toner and carrier (hereinafter referred to as “toner etc.”) because the trickle developing method is employed. The replenishing device 70 includes a holder 71 that detachably holds the toner cartridge 19, a developer transport pipe 72 that transports toner discharged from the toner cartridge 19 to the developer receiving portion 50 a of the developing device 14, and the like. And an agitator as a developer agitating and conveying member (not shown) that rotates in the toner cartridge 19 and an auger or agitator as a developer conveying member (not shown) that rotates in the developer conveying pipe 72. The main part is comprised with the drive device 73 by which the motor, the drive transmission gear mechanism, etc. were arrange | positioned.

  Among these, for the developer transport pipe 72, the first transport pipe 72 a disposed on the end side where the toner discharge port of the toner cartridge 19 is located, the one end of the first transport pipe 72 a, and the developer of the developing device 14. The second transport pipe 72b disposed between the receiving portion 50a (receiving port) and the receiving portion 50a is combined. Reference numeral 75 in the figure denotes a drive transmission shaft that transmits the rotational power of the driving device 73 to the auger of the first transport pipe 72a, and 76 denotes a drive transmission that transmits the rotational power between the drive transmission shaft 75 and the auger of the first transport pipe 72a. A gear mechanism 77 is a drive transmission gear mechanism that transmits the rotational power of the auger of the first transport pipe 72a to the agitator of the second transport pipe 72b.

  In the developer replenishing device 70, when the developer replenishment timing based on the detection information of the magnetic sensor 60 comes as will be described later, the driving device 73 is started and an agitator, developer transport pipe 72a, The auger and agitator in 72b are rotated, whereby the toner in the toner cartridge 19 is sent to the developer receiving portion 50a of the developing device 14 through the developer transport pipes 72a and 72b.

  In this printer, necessary control based on detection information from the magnetic sensor 60 and the like is performed. By this control, the toner replenishing operation is performed only when toner is present in the toner cartridge 19, so that unnecessary toner replenishment can be omitted, the productivity of image formation can be improved, and the life of the image forming apparatus can be extended. Further, since the toner replenishing operation is performed only when toner is present in the toner cartridge 19, if the toner concentration in the developing device 14 does not increase even if the toner replenishing operation is performed, the developer replenishing device 70 is faulty. It can be judged. Hereinafter, the configuration and operation of the control system will be described in detail.

  FIG. 5 is a block diagram showing the main configuration of the control system. Reference numeral 80 in FIG. 6 denotes a control device (control means) that includes an arithmetic processing unit, a memory that stores a control program and detection data, and the like. The control device 80 includes an EEPROM 10m attached to each process cartridge PC, an EEPROM 19m (second detection means: storage unit) attached to each toner cartridge 19, and a magnetic sensor attached to each developing device 14. 60, a main power switch (SW) 65 (not shown) for switching the power ON / OFF operation of the printer main body 1, and a main body front door (not shown) that is opened and closed when the process cartridge PC and the toner cartridge 19 are replaced. An interlock switch (door switch) 66 that is turned on during the opening operation is connected, and necessary detection information used for control processing is input from these connected components.

  The control device 80 comprehensively controls the operation of each component of the driver 81 that controls the drive system (drive device 73) of the developer supply device 70 and the image forming unit 10 and the intermediate transfer mechanism 20. The image forming process controller 82 and the like are connected to each other, and a required control signal or the like from the control device 80 is output to each of these connection destinations. Furthermore, the control device 80 is connected to a controller 83 of a user interface (UI) that collects instruction signals such as a print start instruction and print condition setting by the user. The UI controller 83 is connected to a display unit (interface means) 84 including a liquid crystal panel, a display lamp and the like for performing a required display, and controls the display operation.

  FIG. 6 illustrates threshold values preset in the control device 80. In this graph, the vertical axis represents the toner density TC, and the horizontal axis represents the image formation number PV. As the toner density TC, the normal threshold value (target toner density), the threshold value (EmpStratATC: a threshold value for executing the toner empty detection of the toner cartridge 19), and the threshold value (Empty: toner cartridge) in descending order. 19 is a threshold value for determining that it is empty: a first threshold value, and a threshold value (lower limit: a threshold value for a level at which the toner density TC decreases and the print density also decreases: a second threshold value). The number of sheets before the predetermined number of sheets (for example, 5000 sheets) from the number of image formations at which the toner density TC becomes the threshold (Empty) is set as the near-life threshold (PreNear), and the predetermined number of sheets (for example, 2000) from the near-life threshold (PreNear). The number of sheets after formation is used as a toner cartridge life threshold.

  Hereinafter, the control operation by the control device 80 will be described with reference to the flowcharts shown in FIGS.

  The control device 80 determines whether or not the toner density TC detected by the magnetic sensor 60 is normal (state 0 in FIG. 6) (S101 in FIG. 7). If the toner density TC is an abnormal value, the process proceeds to (* 2) processing step described later. On the other hand, when the toner density TC is a normal value, the control device 80 confirms the use history of the process cartridge PC stored in the EEPROM 10m of the process cartridge PC (abbreviated as “PC” in the flowchart), and performs the process. It is determined whether or not the cartridge PC has a product life (S102 in FIG. 7). Here, if the process cartridge PC has not reached the end of its life, the process proceeds to the processing step (* 3) described later.

  On the other hand, when the process cartridge PC has reached the end of its life, the control device 80 checks the interlock switch (door switch) 66 and the main power switch 65 to check whether the front cover of the main body is opened and closed and whether the main power is on or off. Judgment is made (S103 in FIG. 7). Here, if the cover is not opened and closed and the main power supply is not turned on or off, the process proceeds to the processing step (* 4) described later. On the other hand, when the cover is opened and closed and the main power supply is turned on / off, the control device 80 checks the information in the EEPROM 10m of the process cartridge PC and the EEPROM 19m of the toner cut ridge 19 and reads the information (S104 in FIG. 7). ).

  Then, the control device 80 determines whether or not the process cartridge PC has been replaced from the serial number stored in the EEPROM 10m. If it is determined that the process cartridge PC has not been replaced, the process proceeds to the processing step (* 5) described later. On the other hand, if the process cartridge PC has been replaced, the control device 80 determines whether or not the process cartridge PC is a regular process cartridge PC (S106 in FIG. 7). Here, if it is determined that the process cartridge PC is not a regular process cartridge PC, the control device 80 causes the display unit 84 to display that “the process cartridge PC is not appropriate” and prohibits image formation.

  On the other hand, when it is determined that the process cartridge PC is a regular process cartridge PC, the control device 80 determines whether or not the newly mounted process cartridge PC has already reached its end of life (S108 in FIG. 7). If it is determined that the process cartridge PC has reached the end of its life, the control device 80 prohibits image formation and displays a process cartridge PC replacement request display on the display unit 84 (S109 in FIG. 7). ). On the other hand, when it is determined that the process cartridge PC has not reached the end of its life, the control device 80 determines whether or not the toner cut ridge 19 has been replaced (S110 in FIG. 7). Here, when it is determined that the toner cartridge 19 has been replaced, the process proceeds to a processing step (* 7) described later. On the other hand, if it is determined that the toner cartridge 19 has not been replaced, the process proceeds to the processing step (* 8) described later.

  (* 8) As a processing step, first, the control device 80 determines whether or not the process cartridge PC is new from the use history stored in the EEPROM 10m (S201 in FIG. 8). If it is determined that the process cartridge PC is new, the process cartridge PC recovery operation (1) described later is performed (S202 in FIG. 8). On the other hand, when it is determined that the process cartridge PC is not new, a recovery operation (2) of the process cartridge PC described later is performed (S208 in FIG. 8). Note that image formation is prohibited during the recovery operations (1) and (2).

When the recovery operation (1) is completed, the control device 80 confirms the output from the magnetic sensor 60 (S204 in FIG. 8), and determines whether the toner concentration TC in the developing device 14 is within the normal range (FIG. 8). S205). Here, when the toner density TC is within the normal range, the control device 80 issues a control command to the process controller 82 to enable image formation, and the usage history of the EEPROM 10m is changed from “new” to “non-new”. “New” is written and the fact that the process cartridge PC has been replaced is written in the EEPROM 10m (S207 in FIG. 8). On the other hand, if the toner density TC is not within the normal range, the control device 80 determines that the magnetic sensor 60 is out of order (S206 in FIG. 8).

  When the recovery operation (2) is completed, the control device 80 confirms the usage history of the EEPROM 10m and determines whether or not the process cartridge PC is near the end of its life (S209 in FIG. 8). Here, if it is determined that the lifetime is approaching, the control device 80 issues a control command to the process controller 82 to enable image formation, and “display the process cartridge” on the display unit 84 via the UI controller 83. The message “PC life is nearing” is displayed (S211 in FIG. 8). On the other hand, if it is determined that the lifetime is not approaching, the control device 80 issues a control command to the process controller 82 to enable image formation (S210 in FIG. 8).

  (* 7) As a processing step, first, the control device 80 determines whether or not the toner cartridge 19 is a genuine product by confirming the serial number of the EEPROM 19m (S301 in FIG. 9). Here, when it is determined that the product is not a genuine product, the control device 80 causes the display unit 84 to display “not correct toner cartridge” via the UI controller 83, and issues a control command to the process controller 82. The image formation is prohibited by firing (S302 in FIG. 9). On the other hand, if it is determined that the product is a genuine product, the control device 80 determines whether or not the process cartridge PC is a new product from the use history stored in the EEPROM 10m (S303 in FIG. 9). When it is determined that the process cartridge PC is new, a process cartridge recovery operation (1) described later is performed (S304 in FIG. 9). Note that image formation is prohibited during the recovery operation (1).

  When the recovery operation (1) is completed, the control device 80 confirms the output from the magnetic sensor 60 (S305 in FIG. 9), and determines whether the toner concentration TC in the developing device 14 is within the normal range (FIG. 9). S306). Here, when the toner density TC is within the normal range, the control device 80 issues a control command to the process controller 82 to enable image formation, and the usage history of the EEPROM 10m is changed from “new” to “non-new”. “New” is written and the fact that the process cartridge PC has been replaced is written in the EEPROM 10m (S308 in FIG. 9). On the other hand, when the toner density TC is not within the normal range, the control device 80 determines that the magnetic sensor 60 is out of order (S307 in FIG. 9).

  On the other hand, if it is determined in S303 in FIG. 9 that the process cartridge PC is not new, the control device 80 confirms the output from the magnetic sensor 60 and determines whether the toner concentration TC is within the normal range. Is determined (S309 in FIG. 9). If it is determined that the toner density TC is within the normal range, a process cartridge PC recovery operation (2) described later is performed (S312 in FIG. 9). On the other hand, when it is determined that the toner density TC is not within the normal range, the usage history of the EEPROM 19m is confirmed, and it is determined whether or not the cumulative drive time of the toner dispense motor is before the near-life threshold (FIG. 9). S310). Here, when it is determined that the toner cartridge 19 is at the end of its life, the control device 80 issues a control command to the image forming process controller 82 to prohibit image formation and display the display unit via the UI controller 83. “Toner cut ridge replacement request” is displayed in 84 (S311 in FIG. 9). On the other hand, if the cumulative driving time of the toner dispense motor has not reached the straight threshold during the lifetime, a recovery operation (2) described later is performed (S312 in FIG. 9). Note that image formation is prohibited during the recovery operation (2).

  When the recovery operation (2) is completed, the control device 80 checks the usage history of the EEPROM 10m and determines whether or not the process cartridge PC is nearing the end of its life (S313 in FIG. 9). Here, if it is determined that the lifetime is approaching, the control device 80 issues a control command to the process controller 82 to enable image formation, and “display the process cartridge” on the display unit 84 via the UI controller 83. The message “PC life is nearing” is displayed (S315 in FIG. 9). On the other hand, if it is determined that the lifetime is not approaching, the control device 80 enables image formation by issuing a control command to the process controller 82 (S314 in FIG. 9).

  (* 5) As a processing step, first, the control device 80 determines whether or not the toner cut ridge 19 has been replaced from the serial number stored in the EEPROM 19m (S401 in FIG. 10). If the toner cartridge 19 has not been replaced, the control device 80 issues a control command to the image forming process controller 82 to prohibit image formation (S402 in FIG. 10). This prohibition of image formation (S402) is also a (* 4) processing step.

  On the other hand, if the toner cartridge 19 has been replaced, the control device 80 determines whether or not the toner cut ridge 19 is a regular product (S403 in FIG. 10). Here, if the toner cartridge 19 is not a regular product, the control device 80 issues a control command to the image forming process controller 82 to prohibit image formation, and the “toner cartridge is not appropriate” via the UI controller 83. Is displayed on the display unit 84 (S404 in FIG. 10). On the other hand, if the toner cartridge 19 is a genuine product, the control device 80 stands by (S405 in FIG. 10).

  (* 3) As a processing step, first, the control device 80 determines whether or not the front cover is opened and closed and whether or not the main power source is turned on or off (S501 in FIG. 11). If the cover is not opened and closed and the main power source is not turned on or off, the control device 80 performs the control operation again from step S100 in the state as it is (S510 in FIG. 10). On the other hand, when the cover is opened and closed and the main power supply is turned on / off, the control device 80 checks the information in the EEPROM 10m of the process cartridge PC and the EEPROM 19m of the toner cut ridge 19 and reads the information (FIG. 11). S502).

  Then, the control device 80 determines whether or not the process cartridge PC has been replaced from the serial number stored in the EEPROM 10m. If it is determined that the process cartridge PC has not been replaced, the process proceeds to step S504 described later. On the other hand, when it is determined that the process cartridge PC has been replaced, the control device 80 determines whether or not the process cartridge PC is a regular process cartridge PC (S508 in FIG. 11). Here, if it is determined that the process cartridge PC is not a regular process cartridge PC, the control device 80 causes the display unit 84 to display “invalid process cartridge PC” and prohibits image formation (S509 in FIG. 11). On the other hand, if it is determined that the process cartridge PC is a regular process cartridge PC, the control device 80 determines whether the process cartridge PC has reached the end of its life through (* 6) processing step (S108 in FIG. 7). .

If it is determined that the process cartridge PC has not been replaced (S503 in FIG. 11), the control device 80 determines whether the toner cut ridge 19 has been replaced from the serial number stored in the EEPROM 19m. Judgment is made (S504 in FIG. 11). If the toner cartridge 19 has not been replaced, the control device 80 performs the control operation again from step S100 in the state as it is (S510 in FIG. 10). On the other hand, if the toner cartridge 19 has been replaced, the control device 80 determines whether or not the toner cut ridge 19 is a regular product (S505 in FIG. 11). Here, the toner cartridge 19
Is not a regular product, the control device 80 issues a control command to the image forming process controller 82 to prohibit image formation, and displays a message that the “toner cartridge is not appropriate” via the UI controller 83. (S506 in FIG. 11). On the other hand, when the toner cartridge 19 is a genuine product, the control device 80 stands by in a state where an image can be formed as it is (S507 in FIG. 11).

  (* 2) As a processing step, first, the control device 80 determines whether or not the output of the magnetic sensor 60 is at an empty level (S601 in FIG. 12). Here, when it is not at the empty level, the control device 80 passes through the (* 9) processing step, S510 in FIG. 11, and the (* 1) processing step as it is (S510 in FIG. 10), step S100. Control operation is performed again. On the other hand, if it is at the empty level, the usage history of the EEPROM 19m is confirmed, and it is determined whether or not the cumulative drive time of the toner dispense motor is before the near-life threshold (S602 in FIG. 12). If it is not before the threshold value, the process proceeds to a process step (* 11) described later. On the other hand, if it is before the threshold value, a toner increase operation (1) described later is performed (S603 in FIG. 12). As described above, the toner increasing operation is performed in a state where there is sufficient toner in the toner cartridge 19. Thereafter, the control device 80 confirms the output from the magnetic sensor 60 (S604 in FIG. 12), and determines whether or not the toner concentration TC in the developing device 14 is within the normal range (S605 in FIG. 12). If the toner density TC is within the normal range, the control device 80 stops the image formation skip and restarts the image formation (S607 in FIG. 12). On the other hand, if the toner density TC is not within the normal range, the control device 80 prohibits image formation as a malfunction of the dispense motor (S606 in FIG. 12). As described above, since the toner increasing operation is performed in a state where there is sufficient toner in the toner cartridge 19, if the toner concentration TC does not increase even if the toner increasing operation is performed, the dispense motor is faulty. It can be judged.

  (* 11) As a processing step, the control device 80 performs an empty process for the toner cartridge (S701 in FIG. 13). Next, the control device 80 checks the use history of the process cartridge PC stored in the EEPROM 10m of the process cartridge PC, and determines whether or not the process cartridge PC has a product life (S702 in FIG. 13). Here, if the process cartridge PC has not reached the end of its life, the process proceeds to the processing step (* 12) described later. On the other hand, when the process cartridge PC has reached the end of its life, the control device 80 checks the interlock switch (door switch) 66 and the main power switch 65 to check whether the front cover of the main body is opened and closed and whether the main power is on or off. Judgment is made (S703 in FIG. 13). Here, when the cover is not opened and closed and the main power supply is not turned on / off, the process proceeds to the processing step (* 13) described later. On the other hand, when the cover is opened / closed and the main power supply is turned on / off, the control device 80 checks the information in the EEPROM 10m of the process cartridge PC and the EEPROM 19m of the toner cut ridge 19 and reads the information (S704 in FIG. 13). ).

Then, the control device 80 determines from the serial number stored in the EEPROM 10m whether or not the process cartridge PC has been replaced (S705 in FIG. 13). If it is determined that the process cartridge PC has not been replaced, the process proceeds to a process step (* 14) described later. On the other hand, if the process cartridge PC has been replaced, the control device 80 determines whether or not the process cartridge PC is a regular process cartridge PC (S706 in FIG. 13). Here, if it is determined that the process cartridge PC is not a regular process cartridge PC, the control device 80 causes the display unit 84 to display “invalid process cartridge PC” and prohibits image formation (S707 in FIG. 13). On the other hand, if it is determined that the process cartridge PC is a regular process cartridge PC, the control device 80 determines whether or not the drum cycle of the photosensitive drum 11 has reached the end of life (S708 in FIG. 13). If it is determined that the process cartridge PC has reached the end of its life, the control device 80 prohibits image formation and causes the display unit 84 to display a replacement request display for the process cartridge PC (S709 in FIG. 13). ). On the other hand, when it is determined that the process cartridge PC has not reached the end of its life, the control device 80 determines whether or not the toner cut ridge 19 has been replaced (S710 in FIG. 13). If it is determined that the toner cartridge 19 has been replaced, the process proceeds to the processing step (* 16) described later. On the other hand, if it is determined that the toner cartridge 19 has not been replaced, the process proceeds to the processing step (* 17) described later.

  (* 17) As a processing step, first, the control device 80 determines whether or not the process cartridge PC is a new product from the use history stored in the EEPROM 10m (S801 in FIG. 14). When it is determined that the process cartridge PC is new, a process cartridge recovery operation (1) described later is performed (S802 in FIG. 14). On the other hand, when it is determined that the process cartridge PC is not new, the control device 80 determines whether the toner concentration TC is within the normal range based on information from the magnetic sensor 60 (S808 in FIG. 14). . If the toner concentration TC is not within the normal range, the control device 80 prohibits image formation and displays a request for replacement of the toner cartridge 19 on the display unit 84 (S809 in FIG. 14). On the other hand, when the toner density TC is within the normal range, a recovery operation (2) of the process cartridge PC described later is performed (S810 in FIG. 14). Note that image formation is prohibited during the recovery operations (1) and (2).

  When the recovery operation (1) is completed, the control device 80 confirms the output from the magnetic sensor 60 (S804 in FIG. 14), and determines whether or not the toner concentration TC in the developing device 14 is within the normal range (FIG. 14). S805). Here, when the toner density TC is within the normal range, the control device 80 issues a control command to the process controller 82 to enable image formation, and the usage history of the EEPROM 10m is changed from “new” to “non-new”. “New” is written, and the fact that the process cartridge PC has been replaced is written in the EEPROM 10m (S807 in FIG. 14). On the other hand, when the toner concentration TC is not within the normal range, it is determined that the magnetic sensor 60 is in failure.

  When the recovery operation (2) is completed, the control device 80 confirms the usage history of the EEPROM 10m and determines whether or not the process cartridge PC is near the end of its life (S811 in FIG. 14). Here, if it is determined that the lifetime is approaching, the control device 80 issues a control command to the process controller 82 to enable image formation, and “display the process cartridge” on the display unit 84 via the UI controller 83. The message “PC life is approaching” is displayed (S813 in FIG. 14). On the other hand, if it is determined that the lifetime is not approaching, the controller 80 issues a control command to the process controller 82 to enable image formation (S812 in FIG. 14).

  (* 16) As a processing step, first, the control device 80 determines whether or not the toner cartridge 19 is a genuine product by confirming the serial number of the EEPROM 19m (S901 in FIG. 15). Here, when it is determined that the product is not a genuine product, the control device 80 causes the display unit 84 to display “not suitable toner cartridge” via the UI controller 83, and issues a control command to the process controller 82. The image formation is prohibited by firing (S902 in FIG. 15). On the other hand, if it is determined that the product is a genuine product, the control device 80 determines whether or not the process cartridge PC is a new product from the use history stored in the EEPROM 10m (S903 in FIG. 15). When it is determined that the process cartridge PC is new, a process cartridge recovery operation (3) described later is performed (S304 in FIG. 9). Note that image formation is prohibited during the recovery operation (3).

When the recovery operation (3) is completed, the control device 80 confirms the output from the magnetic sensor 60 (S905 in FIG. 15) and determines whether the toner concentration TC in the developing device 14 is within the normal range (FIG. 15). S906). Here, when the toner density TC is within the normal range, the control device 80 issues a control command to the process controller 82 to enable image formation, and the usage history of the EEPROM 10m is changed from “new” to “non-new”. “New” is written, and the fact that the process cartridge PC has been replaced is written in the EEPROM 10m (S908 in FIG. 15). On the other hand, if the toner concentration TC is not within the normal range, the control device 80 causes the magnetic sensor 60 to
(S907 in FIG. 15).

  On the other hand, if it is determined in S903 in FIG. 15 that the process cartridge PC is not new, the control device 80 determines that the accumulated time of the dispense motor of the toner cartridge 19 exceeds the toner cartridge life threshold from the usage history of the EEPROM 19m. Is determined (S909 in FIG. 15). If the accumulated time exceeds the toner cartridge threshold, the control device 80 prohibits image formation and displays a request for replacement of the toner cartridge 19 on the display unit 84 (S910 in FIG. 15). On the other hand, if the accumulated time does not exceed the toner cartridge threshold, the process proceeds to (* 18) processing step described later.

  (* 14) As a processing step, first, the control device 80 determines from the serial number stored in the EEPROM 19m whether the toner cut ridge 19 has been replaced (S1001 in FIG. 16). If the toner cartridge 19 has not been replaced, the control device 80 issues a control command to the image forming process controller 82 to inhibit image formation (S1002 in FIG. 16). This prohibition of image formation (S1002) is also a (* 13) processing step. On the other hand, when the toner cartridge 19 has been replaced, the control device 80 determines whether or not the toner cut ridge 19 is a regular product (S1003 in FIG. 16). Here, if the toner cartridge 19 is not a regular product, the control device 80 issues a control command to the image forming process controller 82 to prohibit image formation, and the “toner cartridge is not appropriate” via the UI controller 83. Is displayed on the display unit 84 (S1004 in FIG. 16). On the other hand, if the toner cartridge 19 is a genuine product, the control device 80 stands by (S1005 in FIG. 16).

  (* 12) As a processing step, first, the control device 80 determines whether or not the front cover is opened and closed and the main power supply is turned on or off (S1101 in FIG. 17). If the cover is not opened and closed and the main power supply is not turned on or off, the control device 80 prohibits image formation as it is (S1110 in FIG. 17). On the other hand, when the cover is opened / closed and the main power is turned on / off, the control device 80 checks information in the EEPROM 10m of the process cartridge PC and the EEPROM 19m of the toner cut ridge 19 and reads the information (FIG. 17). S1102).

  Then, the control device 80 determines from the serial number stored in the EEPROM 19m whether or not the process cartridge PC has been replaced (S1103 in FIG. 17). If it is determined that the process cartridge PC has not been replaced, the process proceeds to step S1106 described later. On the other hand, when it is determined that the process cartridge PC has been replaced, the control device 80 determines whether or not the process cartridge PC is a regular process cartridge PC (S1104 in FIG. 17). Here, if it is determined that the process cartridge PC is not a regular process cartridge PC, the control device 80 displays on the display section 84 that “the process cartridge PC is not appropriate” and prohibits image formation (S1105 in FIG. 17). On the other hand, if it is determined that the process cartridge PC is a regular process cartridge PC, the control device 80 determines whether or not the process cartridge PC has reached the end of its life through (* 15) processing step (S708).

If it is determined that the process cartridge PC has not been replaced (S1103 in FIG. 17), the control device 80 determines whether the toner cut ridge 19 has been replaced from the serial number stored in the EEPROM 19m. Judgment is made (S1106 in FIG. 17). Here, when the toner cartridge 19 has not been replaced, the control device 80 determines whether or not the cumulative time of the dispense motor of the toner cartridge 19 exceeds the toner cutoff life threshold from the usage history of the EEPROM 19m ( S1109 in FIG. If the accumulated time exceeds the toner cartridge life threshold value, the control device 80 prohibits image formation and displays a request to replace the toner cartridge 19 on the display unit 84 (S1110 in FIG. 17). On the other hand, if the accumulated time does not exceed the toner cut ridge life threshold value, the process proceeds to (* 20) processing step described later.

  On the other hand, when the toner cartridge 19 is replaced, the control device 80 determines whether the toner cartridge 19 is a genuine product by checking the serial number of the EEPROM 19m (S1107 in FIG. 17). If it is determined that the product is not a genuine product, the control device 80 displays a “toner cartridge error” on the display unit 84 via the UI controller 83 and issues a control command to the process controller 82. Image formation is prohibited (S1108 in FIG. 17). On the other hand, if it is determined that the product is genuine, the process proceeds to the processing step (* 19) described later.

  (* 18) (* 19) As a processing step, first, the control device 80 determines from the usage history of the EEPROM 19m whether or not the accumulated time of the dispense motor of the toner cartridge 19 is 0 (S1201 in FIG. 18). If it is determined that the accumulated time is not 0, the control device 80 determines whether or not the accumulated time of the dispense motor of the toner cartridge 19 exceeds the toner cutoff life threshold (S1202 in FIG. 18). ). If the cumulative time exceeds the toner cut ridge life threshold value, the control device 80 prohibits image formation and displays a request to replace the toner cartridge 19 on the display unit 84 (S1203 in FIG. 18). On the other hand, if the accumulated time does not exceed the toner cut ridge life threshold, the process proceeds to step S1204 described later.

  On the other hand, when the accumulated time of the dispense motor of the toner cartridge 19 is 0, in the case of (* 20) processing step, the control device 80 cancels the warning and enables image formation, and displays the toner on the display unit 84. And the toner increase mode (2) described later (see FIG. 21) is started (S1204 in FIG. 18). Then, after performing the toner increase mode (2) until the drive time of the dispense motor elapses for a predetermined time, the control device 80 ends the toner increase mode (2).

FIG. 19 illustrates the recovery operation of the process cartridge PC. FIG. 19A illustrates the recovery operation (1). This recovery operation (1) is for uniformizing the developer stored in the new developing device 14 in the developing device (developing roll). From EEPROM 10m, charging potential, conditions, ATC (auto toner
control: automatic toner control) correction information is read and these setting values are updated. Then, as in normal image formation, the photosensitive drum 10 and the developing roll are rotated while applying each bias voltage, and a developer layer formed on the developing roll is formed and stabilized. Further, the augers 52 and 53 in the developing device 14 are rotationally driven and agitated to eliminate the developer bias. As described above, after the operation of stabilizing the developer layer for a certain time (t1) is performed, the toner concentration from the magnetic sensor 60 is measured, and it is confirmed that the toner concentration is within the normal range, and the process is ended.

  FIG. 19B illustrates the recovery operation (2). This recovery operation (2) is for eliminating the bias of the developer in the developing device 14 that is not new. First, the charging potential, conditions, ATC (auto toner control) correction information, and the like are read from the EEPROM 10m, and these setting values are updated. Then, as in normal image formation, the photosensitive drum 10 and the developing roll are rotated while applying each bias voltage, and a developer layer formed on the developing roll is formed and stabilized. Further, the augers 52 and 53 in the developing device 14 are rotationally driven and agitated to eliminate the developer bias. As described above, after the operation of stabilizing the developer layer for a certain time (t2) is performed, the toner concentration from the magnetic sensor 60 is measured, and it is confirmed that the toner concentration is within the normal range, and the process ends.

  Here, in the recovery operation (1), the developer separately packed in the new developing device 14 is layered on the developing roll, and thus it continues for a relatively long time. On the other hand, the recovery operation (2) is a recovery operation when the process cartridge PC is replaced with a process cartridge PC in which “new” information is written in the EEPROM 10m. In this recovery operation (2), since the layer has already been formed on the developing roll, the deviation of the developer in the developing device 14 is only corrected, and the duration is relatively short (t2 <t1).

  FIG. 19C illustrates the recovery operation (3). This recovery operation (3) is a recovery operation when the process cartridge PC and the toner cartridge 19 are simultaneously replaced while the toner cartridge 19 is empty or nearly empty. In this recovery operation (3), the charging potential, conditions, and ATC (auto toner control) correction information are read from the EEPROM 10m, and these setting values are updated. Then, as in normal image formation, the photosensitive drum 10 and the developing roll are rotated while applying each bias voltage, and a developer layer formed on the developing roll is formed and stabilized. As described above, after performing the operation of stabilizing the developer layer for a certain time (t3≈t1), the toner density from the magnetic sensor 60 is measured, and it is confirmed that the toner density is in the normal range, and the process is ended.

  FIG. 20 illustrates the toner increasing operation (1). In the toner increase operation (1), an image can be formed immediately after replacement with a new toner cartridge 19, and the operation when the toner density TC is lowered to a threshold value (TC lower limit) will be described. FIG. 20A illustrates a case where the toner density TC has decreased after the dispense motor has been driven for a certain period of time. In this case, image formation is temporarily skipped until the toner density TC is recovered. While the image formation is skipped, the toner in the developing device 14 is replenished, the developer in the developing device 14 is stirred, and the toner density TC is repeatedly measured. On the other hand, FIG. 20B illustrates a case where image formation is performed while dispensing is performed for a certain period of time, and the toner density TC is lowered during the image formation. In this case, image formation is temporarily skipped until the toner density TC is recovered.

  FIG. 21 illustrates the toner increase operation (2). In the toner increase operation (2), the operation after replacement with a new toner cartridge 19 will be described. FIG. 21A shows a case where image formation is not performed immediately after the toner cartridge 19 is replaced. In such a case, image formation is accepted while increasing the amount of toner (first mode). FIG. 21B shows a case where image formation is performed immediately after the toner cartridge 19 is replaced. In such a case, if the dispense motor has not been driven for a predetermined drive time even after image formation, the dispense motor is continuously driven after printing is completed. FIG. 21C shows a case where the image formation is performed immediately after the replacement of the toner cartridge 19 and the image formation is restarted. In such a case, image formation is performed while increasing the amount of toner. Even when the toner increase is completed, the toner concentration TC in the developing device 14 is measured at a certain timing to perform normal dispensing operation in order to replenish the toner lost due to image formation.

FIG. 1 is a cross-sectional view showing a color printer as an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the developing device of the color printer of FIG. FIG. 3 is another cross-sectional view of the developing device of the color printer of FIG. FIG. 4 is a perspective view showing the developing device, developer supply device, and toner cartridge of the color printer of FIG. FIG. 5 is a block diagram illustrating a control system of the color printer of FIG. FIG. 6 illustrates the relationship between threshold values. FIG. 7 is a (first) flowchart for explaining the control operation. FIG. 8 is a (second) flowchart for explaining the control operation. FIG. 9 is a (third) flowchart for explaining the control operation. FIG. 10 is a (fourth) flowchart for explaining the control operation. FIG. 11 is a (fifth) flowchart for explaining the control operation. FIG. 12 is a (sixth) flowchart for explaining the control operation. FIG. 13 is a (seventh) flowchart for explaining the control operation. FIG. 14 is a (eighth) flowchart for explaining the control operation. FIG. 15 is a (ninth) flowchart for explaining the control operation. FIG. 16 is a (tenth) flowchart explaining the control operation. FIG. 17 is a (11th) flowchart explaining the control operation. FIG. 18 is a (twelfth) flowchart for explaining the control operation. FIG. 19 illustrates a process cartridge recovery operation. FIG. 20 illustrates the toner increasing operation (1). FIG. 21 illustrates the toner increase operation (2).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Color printer, 80 ... Control apparatus, 79 ... Developer supply apparatus, 10 ... Image forming unit, 84 ... Display part, 14 ... Developing device, 60 ... Magnetic sensor, 19 ... Toner cartridge, 19m ... EEPROM, 10m ... EEPROM

Claims (11)

A developing device that develops the electrostatic latent image on the image carrier with a developer, a developer container that contains the developer, and a developer supply device that replenishes the developer from the developer container to the developing device A control means for controlling the operation of the image forming apparatus,
The control means controls the operation of the image forming apparatus based on the status of the developing device and the status of the developer container. 2. The developer supply device controls the developer supply device so that the developer is supplied from the developer container to the developing device when the concentration of the developer in the developing device becomes lower than a predetermined concentration. The image forming apparatus described in 1. Even if the developer concentration in the developing device is lower than a predetermined concentration, if the amount of the developer in the developer supply device is less than the predetermined amount, the control means includes the developer container. The image forming apparatus according to claim 1, wherein the developer supply device is controlled so as not to supply the developer to the developing device. Even if the developer concentration in the developing device is lower than a predetermined concentration, if the amount of developer in the developer supply device is less than the predetermined amount, the control unit stops image formation. The image forming apparatus according to claim 1. Interface means for notifying the user of the status of the image forming apparatus,
Even if the developer concentration in the developing device is lower than a predetermined concentration, if the amount of developer in the developer supply device is less than the predetermined amount, the control means 5. The image forming apparatus according to claim 1, wherein the interface unit is controlled so as to notify a user that the amount of the developer is less than a predetermined amount. When the concentration of the developer in the developing device is lower than a predetermined concentration and the amount of the developer in the developer supply unit is larger than the predetermined amount, the control unit is configured to perform the development from the developer container. 6. The image forming apparatus according to claim 1, wherein the developer supply device is controlled so as to supply the developer to the device. When the concentration of the developer in the developing device is lower than a predetermined concentration and the amount of the developer in the developer supply unit is larger than the predetermined amount, the control unit is configured to perform the development from the developer container. Control the developer supply device to supply developer to the device,
The developer replenishing device is controlled so that the developer is not replenished from the developer container to the developing device when the developer concentration in the developing device is low even after replenishing the developer. The image forming apparatus according to claim 6. An interface means for notifying a user of the status of the image forming apparatus, and the developer concentration in the developing device is lower than a predetermined concentration and the developer amount in the developer supply device is larger than a predetermined amount In addition, the control unit controls the developer supply device so as to supply the developer from the developer container to the developing device,
8. The interface unit according to claim 1, wherein the interface unit is controlled to notify the user that the image forming apparatus is out of order if the developer concentration in the developing apparatus is low even after the developer is replenished. An image forming apparatus according to claim 1. The developing device includes first detection means for detecting the concentration of the developer in the developing device,
The image forming apparatus according to claim 1, wherein the control unit determines the status of the developing device based on the developer concentration detected by the first detection unit. The developer container includes a second detection means for detecting the amount of developer in the developer container,
The image forming apparatus according to claim 1, wherein the control unit determines a state of the developer supply device based on a developer amount detected by the second detection unit. The image according to claim 10, wherein the second detection unit includes a storage unit that stores a use history of the developer container, and detects the amount of developer in the developer container based on the use history. Forming equipment.

Images