JP2008107813A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress load fluctuation of a drive motor in an apparatus so as to enable sharing of the motor for carrying out an agitating action and a supply action of toner as a developer without increasing the cost of the drive motor, and to provide an image forming apparatus in which the number of drive motors and associated drive mechanisms is reduced, cost reduction for the entire apparatus is achieved and loss of synchronization of the motor and damage to components are prevented. <P>SOLUTION: The image forming apparatus having a plurality of image forming parts, comprises: a plurality of cartridges adapted to supply developer; a plurality of supply members adapted to supply developer to the image forming parts from a plurality of the cartridges; and one drive means adapted to drive a plurality of the supply members. The developer is supplied from a plurality of the cartridges by selectively operating a plurality of the supply members based on the amount of developer accommodated in the cartridges. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus using an electrophotographic system. Here, the image forming apparatus forms an image on a recording medium using an electrophotographic image forming system. For example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile machine, a word processor, and the like are included.

  2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic image process, for example, a configuration as shown in FIG. 2 is known for forming a full color image composed of a plurality of color toner images. The developing means 8 (8Y, 8M, 8C, 8K) for each color, the photoconductor 5 (5Y, 5M, 5C, 5K) as the first image carrier, and the process means acting on the photoconductor, A forming unit (hereinafter referred to as an image forming station) is used. They are arranged in a row so as to face the second image carrier (also referred to as an intermediate transfer member) 12, and toner images of respective colors are laminated and transferred onto the second image carrier 12 and recorded by the secondary transfer means 18. There is an image forming apparatus configured to perform batch transfer onto the material 2. This method is widely used at present because the number of images formed per unit time can be increased when forming a color image.

  The image forming station has at least the process cartridge 22 (22Y, 22M, 22C, 22K). Further, a toner cartridge 11 (11Y, 11M, 11C, 11K) and a toner replenishing means 23 (Y, M, C, K) are provided for supplying toner to the image forming station. The motor is used as a replenishing means driving source (driving unit) for rotating the stirring member for stirring the toner in the process cartridge and for supplying toner from the toner cartridge to the process cartridge. Here, the process cartridge 22 (22Y, 22M, 22C, 22K) has a first image carrier 5 (5Y, 5M, 5C, 5K). Further, it has charging means 7 (7Y, 7M, 7C, 7K) for charging the image carrier. Further, it has developing means 8 (8Y, 8M, 8C, 8K) for supplying toner as a developer to the image carrier. The toner as the developer stored in the toner cartridge 11 (11Y, 11M, 11C, 11K) is supplied to the process cartridge by the toner supply means 23 (23Y, 23M, 23C, 23K).

  The cartridge used in the image forming apparatus is often printed out in large quantities as the speed of the image forming apparatus increases, so that the toner capacity stored in the cartridge tends to increase. In a cartridge with a large toner capacity, a phenomenon that the toner aggregates and the density of the accommodated toner increases by about 30 to 40% (hereinafter referred to as a packing phenomenon) is likely to occur. This packing phenomenon occurs when the cartridge is not used for a long period of time or when it receives vibration in the same posture when the cartridge is transported. When such a packing phenomenon occurs, the rotation load of the agitating member for agitating the toner and the toner replenishing means 23 increases, and depending on the packing state, it becomes difficult to rotate the agitating member, for example, the agitating member itself may be damaged. . In addition, there is a possibility that the motor that is the drive system will step out. Here, the density means the amount of toner per unit volume.

As a solution to this problem, there has been proposed a device that slowly rotates the agitating member at a lower rotational speed than the normal rotational speed at the time of initial rotation of the motor that rotationally drives the agitator that agitates the toner (Patent Document 1). ). Even when the packing phenomenon occurs, a sudden load is not applied by slowly rotating the stirring member. Therefore, the packing can be slowly eliminated without damaging the stirring member or causing the motor to step out.
However, when the speed is lower than usual during the initial rotation as described above, there are the following problems. That is, it is necessary to provide another control circuit for performing a special operation for rotating the motor at different speeds at the time of initial rotation, or to include a speed change mechanism in the drive transmission mechanism between the motor and the stirring member. Adding such a configuration causes an increase in the cost of the entire apparatus.

  On the other hand, as the speed of the image forming apparatus increases, the driving sound when driving the apparatus and the vibration sound generated by the charging member vibrating due to the voltage (AC voltage component) applied to the conductive roller as the charging member. Etc. increase. That is, when the speed of the image forming apparatus is increased, there is a problem that noise that is annoying for the user increases. In particular, when the power of the image forming apparatus is turned on or the cartridge is mounted, there is a possibility that the user may feel uncomfortable about the noise generated at that time because the user is in the vicinity of the printer.

  As described above, as the speed of the image forming apparatus increases, that is, as the process speed increases, the torque of the motor that drives the image forming station in the image forming apparatus increases, and the noise generated during operation increases as the torque increases. It is a trend.

  In order to solve this problem, the following techniques are known. In Patent Document 2, in an initial operation such as when a process cartridge is mounted, the operation is performed at a second process speed that is slower than a process speed in an image forming mode in which an image is formed on commonly used paper such as plain paper. That is, a signal indicating that the power source of the image forming apparatus is turned on, a signal indicating that the process cartridge is mounted, or a signal corresponding to the degree of aggregation of the developer filled in the process cartridge is detected. Then, when any of the signals is detected, the process cartridge is selected so that the initial operation of the process cartridge is performed at the second process speed. That is, the load applied to the drive motor is reduced at the timing when the power is turned on or when the process cartridge is mounted, which is likely to be near the apparatus. As a result, it is possible to reduce noise such as motor drive noise and vibration noise.

According to Patent Document 3, a configuration is adopted in which the motor step-out is prevented by switching the driving current of the stepping motor in accordance with load fluctuations. That is, the image forming apparatus includes a stepping motor that drives some mechanical elements of the image forming apparatus, and a switching unit that switches a driving current of the stepping motor according to a load when driving some mechanical elements.
Japanese Patent Laid-Open No. 1-297677 JP 2004-118028 A JP 2002-369588 A

  By the way, in the color image forming apparatus, for the purpose of downsizing and cost reduction of the apparatus, a configuration in which a toner agitating member for agitating the toner and a motor as a drive source for the toner replenishing means are shared by a plurality of image forming stations. Sometimes taken. In such a case, by using a configuration in which whether or not drive transmission can be selected between the motor that is the drive source and each mechanism, a single motor is used, and a plurality of toner agitating members from the single motor. The toner replenishing means is selectively operated.

  However, in the configuration in which the motor is shared in this manner, the variation factor and variation range of the load on the motor tend to further increase depending on the number of toner stirring members and toner replenishing units that operate simultaneously and the state of the cartridge. That is, since the number of driving objects driven by one motor is increased, the load fluctuation factor is increased and the load fluctuation width is further increased. Accordingly, there is a demand for a motor that can withstand a high load and a motor that can tolerate fluctuations in rotational speed and fluctuations in drive current. However, since such a motor is expensive, there is a problem that it hinders cost reduction of the apparatus.

  Therefore, an object of the present invention is to share a motor that performs a toner agitation operation and a replenishment operation without increasing the cost of the drive motor by suppressing load fluctuations of the drive motor of the apparatus. It is another object of the present invention to provide an image forming apparatus that reduces the number of drive motors and the drive mechanisms associated therewith, reduces the cost of the entire apparatus, and prevents motor step-out and member damage.

  In order to achieve the above object, an image forming apparatus according to the present invention is an image forming apparatus having a plurality of image forming units, a plurality of cartridges for supplying a developer, and the image forming from a plurality of the cartridges. A plurality of replenishing members for replenishing the developer, one driving means for driving the plurality of replenishing members, and a plurality of the replenishing members according to the amount of developer contained in the cartridge. And control means for replenishing developer from the plurality of cartridges.

  Here, when the replenishing members of the plurality of cartridges are driven at the same timing, the control unit selectively operates the plurality of replenishing members according to the amount of developer accommodated in the cartridge. In addition, when the remaining amount of the developer in any one of the plurality of cartridges is a predetermined amount or more, the control unit is configured to determine whether the remaining amount of the developer is a predetermined amount or more. Control is performed so that the supply members of the above cartridges are driven and the supply members of other cartridges are not driven. The control means controls to drive the supply members of all the cartridges when the remaining amount of developer in all the cartridges is less than the predetermined amount. Further, the control means selects to drive the replenishment member in the order in which the remaining amount of developer in the plurality of cartridges is large. The control unit calculates a load generated when the supply member is driven, and selects the supply member so that the calculated load is smaller than an allowable load of a driving unit that drives the supply member. The cartridge is detachable from the image forming apparatus.

  The image forming apparatus of the present invention is an image forming apparatus having a plurality of image forming units each having a developing unit for containing a developer, and includes a plurality of cartridges for replenishing the developer and a plurality of the cartridges. A plurality of replenishing members for replenishing developer to the developing unit, a driving means for driving the plurality of replenishing members, and a plurality of the replenishing members selected according to the amount of developer in the developing unit And control means for replenishing the developer from the plurality of cartridges.

  Here, when the replenishing members of the plurality of cartridges are driven at the same timing, the control unit selectively operates the plurality of replenishing members according to the amount of developer accommodated in the developing unit. . Further, the control unit selects to preferentially drive the replenishing member corresponding to the image forming unit having a small amount of developer remaining in the plurality of developing units. The image forming unit is detachable from the image forming apparatus.

  According to another aspect of the present invention, there is provided an image forming apparatus having a plurality of image forming portions for containing a developer, a plurality of cartridges for replenishing the developer, and a plurality of the cartridges to the image forming portion. A plurality of replenishing members for replenishing the developer, one driving means for driving the plurality of replenishing members, the amount of developer in the image forming unit, and the remaining amount of developer in the cartridge And a control means for selectively operating the plurality of supply members to supply the developer from the plurality of cartridges.

  Here, the control unit sets the priority of the replenishment operation of the plurality of replenishment members based on the amount of developer in the image forming unit, and the plurality of replenishers based on the remaining amount of developer in the cartridge. Which replenishment member is to be operated is set.

  According to the present invention, it is possible to share a motor that performs a stirring operation and a replenishing operation of toner as a developer without increasing the cost of the driving motor by suppressing load fluctuations of the driving motor of the apparatus. Further, the number of drive motors and the drive mechanisms associated therewith can be reduced, the cost of the entire apparatus can be reduced, and motor step-out and member damage can be prevented.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. . Further, the material, shape, etc. of the members once described in the following description are the same as those in the first description unless otherwise described.

<Example of Configuration of Image Forming Apparatus of Present Embodiment>
FIG. 2 is a cross-sectional view illustrating a schematic configuration of the image forming apparatus according to the embodiment. The image forming apparatus of this embodiment is a color laser printer.

  The color laser printer according to the embodiment forms an electrostatic latent image based on an image signal at an image forming station, and develops the electrostatic latent image to form a visible image. This visible image is superimposed and transferred onto an intermediate transfer member to form a color image, and this color image is secondarily transferred to a recording material as a recording medium, and then the color visible image is fixed.

  The image forming apparatus includes an image forming station as an image forming unit, scanners 10Y, 10M, 10C, and 10K as exposure units, primary transfer units 6Y, 6M, 6C, and 6K, an intermediate transfer body 12, a sheet feeding unit, and a secondary transfer unit. The unit 18 and the fixing unit 13 are configured. The image forming station includes process cartridges 22Y, 22M, 22C, and 22K. Process cartridges 22Y, 22M, 22C, and 22K are photosensitive drums 5Y, 5M, 5C, and 5K as image carriers for image stations arranged in parallel for development colors, and charging units (also referred to as chargers) 7Y and 7M as charging means. , 7C, 7K. The process cartridges 22Y, 22M, 22C, and 22K include developing units (also referred to as developing units) 8Y, 8M, 8C, and 8K as developing means, and scanners 10Y, 10M, 10C, and 10K as exposure means. Each process cartridge is deteriorated with use of the photosensitive drum, the charger, and the developing device, and is thus configured to be replaceable (detachable) with respect to the image forming apparatus. In addition, toner replenishing means 23Y, 23M, 23C, and 23K for supplying toner as a developer to the process cartridge and toner cartridges 11Y, 11M, 11C, and 11K including a toner container for storing the toner are exchanged for the image forming apparatus. It is possible (detachable). Each toner cartridge is replaced when the toner runs out.

  Here, there is one motor for driving the toner replenishing means 23Y, 23M, 23C, and 23K. That is, all cartridges are driven by a common motor. The motor is connected to each toner replenishing means via a drive transmission mechanism (not shown). The toner supply means 23Y, 23M, 23C, and 23K can be selectively driven individually by the drive transmission mechanism.

(Configuration example of toner replenishing means)
FIG. 3 is a cross-sectional view showing a schematic configuration of the toner replenishing means.

  The toner cartridge 11 and the process cartridge 22 have a toner agitation / replenishment screw 24 as a replenishing member for replenishing the toner while stirring, and a toner replenishment shutter 25 between the toner cartridge and the process cartridge. Then, these are driven by a motor to execute a toner supply operation.

<Example of block configuration of toner replenishment control>
FIG. 1A shows a block diagram of control related to toner supply used in the present embodiment.

  The toner supply control block includes a toner supply control unit 401, a toner remaining amount detection unit 404, a load torque calculation unit 405, and a toner supply unit driving unit 406. The toner supply control unit 401 includes a toner supply request determination unit 402 and a toner supply operation station selection unit 403. The toner replenishment request determination unit 402 determines whether toner replenishment is necessary in each image forming station, and the toner replenishment operation station selection unit 403 determines whether or not the toner replenishment request station actually permits toner replenishment. select. The toner remaining amount detection unit 404 includes a detection unit 404 a that detects the remaining amount of toner in the toner cartridge 11 and a detection unit 404 b that detects the remaining amount of toner in the process cartridge 22.

  The detection units 404a and 404b are configured to calculate the remaining toner amount of each image forming station, and the load torque calculation unit 405 is also configured to calculate the load torque amount of each image forming station. . Further, the toner replenishing means driving unit 406 is configured to receive a replenishment permission for the toner replenishing means 23 of each image forming station and independently generate a driving signal for each image forming station.

  The toner replenishment control unit 401 determines whether each image forming station needs toner replenishment. If toner replenishment is required, the remaining amount of toner in each cartridge is referred to by the detection units 404a and 404b. Subsequently, a toner replenishment request is sent to the toner replenishment operation station selection unit 403, and it is selected whether or not replenishment is actually permitted to the requested image forming station. At that time, the information on the remaining amount of toner in the cartridge and the amount of torque generated at the time of toner replenishment are referred to by the detection units 404a and 404b and the load torque calculation unit 405 as necessary. From the toner replenishment operation station selection unit 403, information on a station that permits toner replenishment is given to the toner replenishing means driving unit 406. In the toner replenishing means driving unit 406, a drive signal is generated for a station where toner replenishment is permitted, and the toner replenishing operation by the actual toner replenishing means 23 is performed.

(Toner remaining amount detection example)
As a method for detecting the remaining amount of toner, an optical detection method is known in which the amount of toner remaining is detected by detecting the time during which light passes through the cartridge. This method allows light to pass through the cartridge while stirring the toner, reads the light transmitted at a fixed period, and determines the remaining amount in the cartridge based on the time when the transmitted light is read or the ratio of the time of transmitted light and non-transmitted light. This is a detection method.

  In the toner cartridge, the number of operations (number of rotations and rotation time) of the toner replenishing means is calculated. In the process cartridge, the amount of toner replenished from the toner cartridge and the amount of toner consumed during image formation are calculated. There is also a method for estimating the amount of toner in the cartridge based on these. There is also a method of detecting the remaining amount of toner by attaching a sheet metal inside the toner cartridge or process cartridge and measuring the electrostatic capacity. In addition, in order to detect the remaining amount of toner with high accuracy, the above methods may be combined or selected for use.

<Hardware replenishment control hardware configuration example>
FIG. 1B shows a hardware configuration example for performing toner replenishment control of this embodiment. In FIG. 1B, only components deeply related to the present embodiment are shown, and general-purpose or thinly related components are not shown.

  In FIG. 1B, reference numeral 100 denotes an arithmetic control CPU that controls toner supply control (corresponding to 401 in FIG. 1A). Reference numeral 200 denotes a ROM that stores a program for operating procedures of the CPU 100 and fixed parameters used for toner supply control. Reference numeral 300 denotes a RAM used as a temporary storage when the CPU 100 performs toner replenishment control using the program of the ROM 200 using its parameters.

  The ROM 200 stores a toner replenishment control program 210 corresponding to the flowchart shown below. The toner supply control program 210 includes a toner remaining amount detection module 211, a load torque calculation module 212, a supply station selection module 213, a supply means driving module 214, and the like. The ROM 200 stores parameters 220 used for station selection. The station selection parameter 220 includes, for example, an upper limit number 221 of driving stations (used in the first embodiment) and a remaining toner threshold value 222 (used in the second embodiment). Further, a toner remaining amount / load torque table 223 (used in the third embodiment), a load torque upper limit value (used in the third and fourth embodiments), and a station priority 225 (used in the fourth embodiment) are included.

The RAM 300 stores a toner replenishment request station 301, a toner replenishment execution station 302, a drive station number 303 (used in the first embodiment), and a load torque integrated value 304 (used in the third and fourth embodiments) as control parameters. . Further, as the cartridge data 310 for each color unit, for example, a replenishment request flag / execution flag 321 of the Y cartridge 320, a toner cartridge remaining amount 322, a process cartridge remaining amount 323, and a calculated load torque 324 are held. The description of the M cartridge data 330 and the following is omitted.
Reference numeral 400 denotes an input interface for inputting information used for toner supply control. Via the input interface 400, a toner remaining amount value from the toner cartridge detection unit 404a, a toner remaining amount value from the process cartridge detection unit 404b, and a signal for controlling the timing of toner replenishment are input. As the toner replenishment timing signal, for example, a signal indicating the end of the image forming process is used as shown in FIG.

  An output interface 500 outputs a control signal for toner replenishment control. Via the output interface 500, a motor drive signal for controlling the drive motor shared by the toner replenishing means for all colors and a permission signal for permitting the replenishing operation of the toner replenishing means 23Y, 23M, 23C, and 23K are output.

  Based on the remaining toner data obtained via the input interface 400, the CPU 100 uses the RAM 300 as a work area according to the program and parameters stored in the ROM 200, and selects the toner replenishing means to be driven. The selected toner supply means is driven via the output interface 500.

[Toner Supply Control of First Embodiment]
The image forming apparatus according to the present exemplary embodiment determines whether to replenish toner at each image forming station every time image formation is performed.

  When it is determined that toner replenishment is necessary for a plurality of image forming stations, the following determination is further made. (1) If the number of image forming stations that require toner replenishment is equal to or less than the number that can be driven simultaneously, a selection signal for permitting toner replenishment is issued in all image forming stations to execute toner replenishment operation. On the other hand, if (2) the number of stations requiring toner replenishment is greater than the number that can be driven simultaneously, the number of stations that require toner replenishment is selected. Then, a toner replenishing operation is executed by issuing a selection signal for permitting toner replenishment at the selected image forming station. A station that determines that toner replenishment is necessary but cannot perform toner replenishment requests the toner replenishment again at the next image formation.

  In the present embodiment, toner supply to all stations is driven by a common motor. In this embodiment, it is assumed that toner can be replenished at two image forming stations simultaneously. The number of image forming stations that can be replenished with toner at the same time can be changed depending on conditions such as motor capability. After completion of the toner image formation at the image forming station, whether or not toner supply to the process cartridge is necessary is determined based on the remaining amount of toner or the amount of toner consumed at the time of image formation.

  For example, when the toner supply operation is required only for the process cartridge 7K, the toner supply operation is performed in the process cartridge 7K because the toner supply operation is performed by one station.

  Further, when it is necessary to replenish toner for the three process cartridges 7Y, 7M, and 7C, the replenishment operation can be performed simultaneously at two image forming stations. Operation is performed. For the process cartridge 7C, it is determined that toner replenishment is required in the next image formation, and if there is another process cartridge that needs toner replenishment, toner replenishment is executed together with that cartridge.

(Example of operation procedure of Embodiment 1)
FIG. 4 shows a flowchart of an example of a toner replenishment operation procedure in the present embodiment.

  At the start of toner replenishment (S101), image forming stations that need toner replenishment are determined (S102), and it is determined whether the number of image forming stations that require toner replenishment is equal to or less than the number that can be executed simultaneously (S103). . If the number of image forming stations that require toner replenishment is less than the number that can be simultaneously executed, the toner replenishment operation is permitted in all of them (S105). On the other hand, if the number of stations that require toner replenishment is greater than the number that can be executed simultaneously, the station that performs toner replenishment operation for the number that can be executed simultaneously is selected from the process cartridges that require toner replenishment. Is permitted (S104).

  After the determination of permission for toner replenishment is completed, toner replenishment is executed for the station to which toner replenishment permission is given (S106).

  The station that has not been replenished with toner is determined to be replenished with toner at the next image formation, and replenishes toner.

(Example of operation timing of Embodiment 1)
FIG. 5 shows a timing chart of the toner supply operation in the present embodiment.
After completion of image formation, it is determined whether toner replenishment is required for each image forming station, and a toner replenishment request is issued (S501 to S503). Next, in response to the toner replenishment request, the number of stations that permit toner replenishment is selected as many as the number that can be driven simultaneously, and toner replenishment permission is issued to the Magenta and Yellow stations (S504, S505). In response to the issued toner supply permission, a toner supply operation is executed (S506, S507).

  For Cyan stations that are not permitted to supply toner, a toner supply request is issued again after the completion of the next image formation (S508). Along with the newly issued replenishment request (S509), the number of stations that are allowed to replenish toner is selected again so that it can be driven simultaneously, and toner replenishment permission is issued to Cyan and Black stations (S510, S511). Then, toner replenishment is executed (S512, S513).

(Effect of Embodiment 1)
By performing the above control, it is possible to suppress an increase in load torque by suppressing the number of stations where toner is replenished simultaneously to a certain number or less.

[Toner Supply Control of Second Embodiment]
In the first embodiment, the increase in load torque is suppressed by limiting the number of toner replenishment drives simultaneously to a fixed value regardless of the state of each cartridge. However, the load torque generated by the toner replenishing operation varies depending on the state of the cartridge to be replenished.

  In the present embodiment, the toner replenishment operation is performed with respect to the load torque generated during the toner replenishment operation for a certain period after the installation of a new cartridge, which may generate a large load torque, or when the remaining amount of toner in the toner cartridge is greater than a certain amount. Put a limit. By such processing, an increase in load torque is suppressed.

  As an example, it is considered that a load torque higher than usual is applied until the remaining amount of toner becomes 90% or less. Under these conditions, it is assumed that the remaining amount of the toner cartridges 11Y, 11M, and 11C is 70%, and the remaining amount of the toner cartridge 11K is 100% immediately after mounting. In this case, when the toner supply operation from the toner cartridge 11K is performed, control is performed so that the toner supply operation by another station is not permitted.

(Example of operation procedure of Embodiment 2)
FIG. 6 shows a flowchart of a processing procedure example of the present embodiment.

  At the start of the replenishment operation (S601), it is checked whether a replenishment operation with a toner cartridge having a remaining amount of 90% or more is performed (S602). If toner is supplied from a toner cartridge having a remaining amount of 90% or more, one station is selected from the toner cartridge, and the toner supply operation is permitted, and toner supply from other stations is not permitted (S603). On the other hand, if the toner cartridge that performs toner replenishment does not contain 90% or more remaining toner, all toner replenishment operations are permitted (S604).

  When the selection of the station for which toner replenishment is permitted is completed, toner replenishment is performed only for the stations for which toner replenishment is permitted (S605).

  Selection of a station that permits toner replenishment is rotated for each replenishment operation, so that each station can equally give an opportunity for toner replenishment. That is, for example, when the cartridges 11K, 11Y, and 11M have a remaining amount of 90% or more, the order is rotated as 11K → 11Y → 11M → 11K.

(Another operation procedure example of the second embodiment)
In the present embodiment, the control for selecting a station that permits toner replenishment is executed only when there is a toner replenishment request for an image forming station that includes a toner cartridge having a remaining amount of 90% or more. However, when there is a toner cartridge with a remaining amount exceeding a certain level, an image forming station that permits toner replenishment may be set every time toner replenishment is performed, regardless of the presence or absence of toner replenishment operation of the station. In this case, it is possible to obtain the same effect with a simpler control with respect to an increase in the load torque by controlling the number of stations where toner replenishment is always performed to be constant or less.

  FIG. 7 shows a flowchart relating to the toner replenishing operation in the present embodiment. Note that the difference from FIG. 6 is only the criterion in step S702. That is, whether or not a replenishment operation with a toner cartridge having a remaining amount of 90% or more in FIG. 6 is performed is checked (S602), and whether or not there is a toner cartridge with a remaining amount exceeding a certain level is checked (S702). Since other steps are common, description thereof is omitted.

(Effect of Embodiment 2)
The above control suppresses the increase in load torque by restricting the simultaneous driving of toner replenishment immediately after the toner cartridge, which may increase the load torque, or when the toner remaining in the toner cartridge exceeds a certain level. It becomes possible to do.

[Toner Supply Control of Embodiment 3]
In the second embodiment, it is determined whether or not to limit toner supply according to the remaining amount of the toner cartridge. In the present embodiment, the load torque generated at the time of toner replenishment depending on the remaining amount of toner in the toner cartridge is quantified as a ratio to the maximum load torque that can be allowed by the motor. Thereby, control corresponding to the change of load torque is performed more flexibly.

  The image forming apparatus according to the present embodiment associates the remaining amount of toner with the allowable load torque as follows. When the remaining amount of toner in the toner cartridge is 90% or more, the load torque generated during the toner supply operation at the station is set to 70% with respect to the allowable load torque of the motor. The load torque generated when the remaining amount of toner is less than 90% and 70% or more is 50% of the allowable load torque of the motor. The load torque generated when the remaining amount of toner is less than 70% and 50% or more is 30% of the allowable load torque of the motor. The load torque generated when the remaining amount of toner is less than 50% is 20% of the allowable load torque of the motor. The enumeration is as follows.

Toner remaining 90% or more: Motor allowable load torque 70%
Less than 90% to 70% or more of toner remaining: Motor allowable load torque 50%
Less than 70% toner remaining amount to 50% or more: Motor allowable load torque 30%
Less than 50% toner remaining: Motor allowable load torque 20%
For example, in the image forming apparatus in which the remaining amount of the toner cartridge 11Y is 40%, the remaining amount of the toner cartridge 11M is 45%, the remaining amount of the toner cartridge 11C is 40%, and the remaining amount of the toner cartridge 11K is 75%. Control as follows.

  In this case, the load torque applied by toner supply in 11Y is 20% of the allowable value, 20% in 11M, 20% in 11C, and 50% in 11K. When it is determined that toner replenishment is necessary at the same timing in all the stations, the station that performs toner replenishment is determined as follows.

  First, toner supply with the toner cartridge 11K is permitted. Subsequently, toner supply is permitted in the order of the toner cartridges 11C and 11M. At this time, the ratio of the generated load torque to the allowable load torque is 90%. Subsequently, when the toner supply by the toner cartridge 11Y is permitted, the generated load torque is 110%, which exceeds the allowable load torque amount. For this reason, toner supply by 11Y is not permitted, and toner supply in toner cartridges 11K, 11C, and 11M is permitted and executed.

(Example of operation procedure of Embodiment 3)
FIG. 8 shows a flowchart of the toner supply operation in the present embodiment.

  At the start of toner replenishment (S801), first, toner replenishment of all image forming stations is set to be not permitted (S802). Then, one is selected from the image forming stations for which toner supply is requested (S804). The selection is performed in the order of the toner cartridges 11K, 11C, 11M, and 11Y corresponding to the image forming station. A load torque amount generated from the remaining amount of the toner cartridge in the image forming station is obtained. The calculated load torque amount is added to the total load torque amount generated at the image forming station that is currently permitted to supply toner (S805), and is compared with the allowable load torque amount (S806).

  If the amount is less than the allowable load torque amount, the toner supply operation of the image forming station is permitted (S807). If it is larger than the allowable load torque amount, the toner supply operation of the image forming station is not permitted. The above is sequentially performed for all the image forming stations having a toner replenishment request (S808), and after it is determined whether or not toner replenishment is possible for all the image forming stations, toner replenishment is executed in the permitted image forming stations ( S809).

  In this embodiment, the determination is made in the order of K, C, M, and Y, but the selection method is not limited to this order. For example, it is possible to use a method of dynamically changing the priority order such as selecting an image forming station so that the number of image forming stations that can be simultaneously executed is maximized.

(Effect of Embodiment 3)
The feature of this embodiment is that the toner supply operation is selected so that the load torque generated at the selected image forming station is always smaller than the maximum allowable load torque of the motor when the toner supply operation is executed simultaneously. It can be done.

[Toner Supply Control of Embodiment 4]
In the first, second, and third embodiments, the increase in load torque is suppressed by selectively allowing toner replenishment without considering the remaining amount of toner in the process cartridge. However, in this embodiment, even when the remaining amount of the toner cartridge is large and there is a possibility that the load torque may be increased, there is a case where the toner in the process cartridge is extremely small. If toner replenishment is delayed at this time, there is a possibility that the density of the toner image formed at the station will become thinner or the like. For this reason, it is necessary to preferentially replenish the toner to the process cartridge with a small amount of toner remaining.

  Therefore, in the present embodiment, when toner replenishment operations are required at a plurality of stations at the same time, control for permitting toner replenishment is performed in the order of the stations with the smallest remaining amount of toner in the process cartridge. Note that the image forming apparatus of the present embodiment is configured to detect the remaining amount of toner in the process cartridge.

  As in the example of the third embodiment, the remaining amount of the toner cartridge 11Y is 40%, the remaining amount of 11M is 45%, the remaining amount of 11C is 40%, and the remaining amount of 11K is 75%. In this case, the load torque applied by toner replenishment at 11Y is 20% of the allowable value, 20% at 11M, 20% at 11C, and 50% at 11K.

  Here, in this embodiment, the remaining amount of toner in the process cartridge 22Y is 50%, the remaining amount of toner in 22M is 70%, the remaining amount of toner in 22C is 20%, and the remaining amount of toner in 22K is 80 in this embodiment. %.

  FIG. 10 shows the remaining amount of toner in the process cartridge and the priority of the replenishment operation of the image forming station in this embodiment. In FIG. 10, the priority of the process cartridge 22C having the smallest remaining amount of toner is set highest. After that, the order is 22Y, 22M, and 22K.

  When the replenishment operation is requested at all image forming stations at the same time, for example, it is determined whether or not the toner replenishment operation can be executed in the order shown in FIG. This priority is changed and updated according to the remaining amount of toner in the process cartridge, and is referred to by the CPU 100 when a toner supply request is made.

  When it is determined that all the stations need to be replenished with toner under these conditions, the station to be replenished with toner is determined as follows.

  First, the toner supply from the toner cartridge 11C is permitted to the process cartridge 22C having the smallest remaining amount of toner. Subsequently, toner supply is permitted in the order of the toner cartridges 11Y and 11M in ascending order of the remaining amount of toner in the process cartridge. At this time, the ratio of the generated load torque to the allowable load torque is 60%.

  Subsequently, when the toner supply by the toner cartridge 11K is permitted, the generated load torque is 110%, which exceeds the allowable load torque amount. Therefore, toner replenishment by 11K is not permitted, and toner replenishment in toner cartridges 11C, 11Y, and 11M is permitted and executed.

  That is, in this embodiment, the toner replenishing operation is performed in consideration of both the load torque based on the toner remaining amount in the toner cartridge and the replenishment priority based on the toner remaining amount in the process cartridge.

(Example of operation procedure of Embodiment 4)
FIG. 9 shows a flowchart of the toner supply operation in the present embodiment. The difference from the third embodiment is that the priority for permitting toner supply is determined by the remaining amount of toner in the process cartridge.

  At the start of toner replenishment (S901), first, toner replenishment of all image forming stations is set to be not permitted (S902). Then, the remaining amount of toner in the process cartridge of the image forming station that is requested to replenish toner is calculated (S904). Then, among the unselected stations, the image forming station with the smallest remaining amount of toner is selected (S905). In other words, this selection is performed one by one in the order of the remaining amount of toner in the process cartridge. A load torque amount generated from the remaining amount of toner cartridges in the image forming station is obtained, and the calculated load torque amount is added to the total load torque amount generated in the image forming station that is currently permitted to supply toner (S906). ).

  The allowable load torque amount is compared (S907). If the amount is less than the allowable load torque amount, the toner supply operation of the image forming station is permitted (S908). If the load torque amount is larger than the allowable load torque amount, the toner supply operation of the image forming station is not permitted. The above is performed for all image forming stations having a toner replenishment request (S909). After it is determined whether toner replenishment is possible for all image forming stations, toner replenishment is executed in the permitted image forming stations (S910). ).

(Effect of Embodiment 4)
With the above control, it is possible to limit the simultaneous execution of toner supply while preventing the toner in the process cartridge from running out. Accordingly, it is possible to suppress an increase in load torque even when toner replenishment is performed simultaneously while reducing the influence on the formed toner image.

  In this embodiment, the case where there is a toner replenishment request for all the image forming stations at the same time has been described. However, the present invention can be applied even when the toner replenishment request is not for all the image forming stations.

  In addition, although the said Embodiment 1 thru | or 4 demonstrated each independently, the example which combined these Embodiment 1 thru | or 4 and the example which added other conditions are also possible, and these are also contained in this invention.

  Further, the present invention can be applied to a system (copier, printer, facsimile machine, etc.) consisting of a single device even if it is applied to a system consisting of a plurality of devices (eg, computer, interface device, reader, printer, etc.). May be.

  The object of the present invention can also be achieved by using a recording medium (or storage medium) that records a program code of software that implements the functions of the above-described embodiments. In this case, the recording medium is supplied to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the recording medium. In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiment, and the recording medium on which the program code is recorded constitutes the present invention.

  Further, the functions of the above-described embodiment are realized by executing the program code read by the computer. Further, based on the instruction of the program code, an operating system (OS) running on the computer performs part or all of the actual processing. The case where the function of the above-described embodiment is realized by the processing is also included.

Further, the program code read from the recording medium is written in a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer. Thereafter, the CPU of the function expansion card or the function expansion unit performs part or all of the actual processing based on the instruction of the program code, and the function of the above-described embodiment is realized by the processing. .
Further, program data for realizing the functions of the above-described embodiments is downloaded from a CD-ROM set in the own device or an external supply source such as the Internet to the memory of the own device. Thus, a form in which the functions of the above-described embodiments are realized is also included in the present invention.

  When the present invention is applied to the recording medium, it is preferable that program code corresponding to the flowchart described above is stored in the recording medium.

FIG. 6 is a block diagram relating to toner supply control according to the present embodiment. FIG. 3 is a diagram illustrating a hardware configuration example that realizes toner supply control according to the present embodiment. 1 is a diagram illustrating a configuration example of a laser beam printer which is an image forming apparatus according to an embodiment. FIG. 4 is a diagram illustrating a configuration example of a toner replenishment unit according to the present embodiment. 3 is a flowchart illustrating an example of an operation procedure in the first embodiment. 3 is a timing chart illustrating an operation example in the first embodiment. 10 is a flowchart illustrating an example of an operation procedure in the second embodiment. 10 is a flowchart illustrating an example of an operation procedure when toner supply is always restricted when a high-load cartridge according to the second exemplary embodiment exists. 10 is a flowchart illustrating an example of an operation procedure in the third embodiment. 10 is a flowchart illustrating an example of an operation procedure in the fourth embodiment. FIG. 10 is a diagram illustrating the priority of toner replenishment operation in the fourth embodiment. FIG. 6 is a block diagram related to toner supply control according to the present embodiment.

Explanation of symbols

5Y, 5M, 5C, 5K Photosensitive drum, photosensitive belt (image carrier)
6Y, 6M, 6C, 6K Primary transfer roller (primary transfer means)
7Y, 7M, 7C, 7K Primary charger (charging means)
8Y, 8M, 8C, 8K Developer (Developer)
10Y, 10M, 10C, 10K scanner (exposure means)
11Y, 11M, 11C, 11K Toner cartridge 12 Intermediate transfer belt (intermediate transfer member)
13 Fixing means 18 Secondary transfer means 22Y, 22M, 22C, 22K Process cartridge 23Y, 23M, 23C, 23K Toner replenishing means 24 Toner stirring / replenishing screw 25 Toner replenishing shutter

Claims (13)

An image forming apparatus having a plurality of image forming units,
A plurality of cartridges for replenishing developer;
A plurality of replenishing members that replenish the developer from the plurality of cartridges to the image forming unit;
One driving means for driving the plurality of supply members;
An image forming apparatus comprising: a control unit that selectively operates the plurality of supply members according to the amount of developer stored in the cartridge to supply the developer from the plurality of cartridges.   The control unit selectively operates the plurality of supply members according to the amount of developer accommodated in the cartridge when the supply members of the plurality of cartridges are driven at the same timing. The image forming apparatus according to claim 1.   When the remaining amount of the developer in any one of the plurality of cartridges is a predetermined amount or more, the control means is configured so that the remaining amount of the developer is a predetermined amount or more. 3. The image forming apparatus according to claim 2, wherein the supply member of the cartridge is driven and the supply member of the other cartridge is controlled not to be driven.   The control means controls to drive the supply members of all the cartridges when the remaining amount of developer in all the cartridges is less than the predetermined amount. The image forming apparatus according to 3.   The image forming apparatus according to claim 2, wherein the control unit selects the driving of the replenishing member in the order in which the remaining amount of developer in the plurality of cartridges is large.   The control unit calculates a load generated when the supply member is driven, and selects the supply member so that the calculated load is smaller than an allowable load of a drive unit that drives the supply member. The image forming apparatus according to claim 5.   The image forming apparatus according to claim 1, wherein the cartridge is detachable from the image forming apparatus. An image forming apparatus having a plurality of image forming units having a developing unit for containing a developer,
A plurality of cartridges for replenishing developer;
A plurality of replenishing members for replenishing the developer from the plurality of cartridges to the developing section;
One driving means for driving the plurality of supply members;
An image forming apparatus comprising: a control unit that selectively operates the plurality of supply members according to the amount of developer in the developing unit to supply the developer from the plurality of cartridges.   The control means selectively operates the plurality of supply members according to the amount of developer accommodated in the developing unit when the supply members of the plurality of cartridges are driven at the same timing. The image forming apparatus according to claim 8.   The image forming apparatus according to claim 9, wherein the control unit selects to preferentially drive the replenishment member corresponding to an image forming unit having a small amount of developer remaining in the plurality of developing units. .   The image forming apparatus according to claim 8, wherein the image forming unit is detachable from the image forming apparatus. An image forming apparatus having a plurality of image forming units containing a developer,
A plurality of cartridges for replenishing developer;
A plurality of replenishing members that replenish the developer from the plurality of cartridges to the image forming unit;
One driving means for driving the plurality of supply members;
Control means for replenishing the developer from the plurality of cartridges by selectively operating the plurality of the replenishing members according to the amount of developer in the image forming unit and the remaining amount of the developer in the cartridge. An image forming apparatus comprising:   The control means sets a priority of the replenishment operation of the plurality of replenishment members based on the amount of developer in the image forming unit, and the plurality of replenishment members based on the remaining amount of developer in the cartridge The image forming apparatus according to claim 12, wherein which of the two is to be operated is set.

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