JPH1184837A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the aggregation of toner and to prevent the deterioration of image quality by stirring the toner in a toner container when an image forming device is left standing. SOLUTION: The power source of the device main body is turned off, simultaneously, a toner stirring mode of stirring the toner in accordance with a signal from an inputting means to which a user and a service man input a signal of instructing the execution of a toner stirring operation is executed by a control part. As for the toner stirring mode, it is judged by the control part whether or not the signal of instructing the execution of the toner stirring operation is inputted to the inputting means (step S2), and in the case the signal of instructing the execution of the toner stirring operation is inputted, the toner stirring operation is executed by the control part (step S3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art Conventionally, there is known an image forming apparatus which has a toner container for storing toner and forms an image using the toner.

[0003]

However, in the above-described image forming apparatus, if the power supply is turned off, that is, the state in which the image forming apparatus is not used continues for a long time, the toner in the toner container hardly aggregates. As a result, the aggregate of the toner in the toner container is mixed into the developer in the developing device and stirred, and the aggregate of the toner is directly developed on the image formed at the time of image formation. Occurs.

[0004] In order to solve this problem, there is known a configuration in which a stirring device for stirring the toner in the toner container is provided. However, if the image forming apparatus has been left for a long time in the power-off state, even when the toner in the container is agitated by the agitating device at the time when the power of the image forming apparatus is turned on, the toner which has been hardly aggregated may be removed. I can't loosen it enough. FIG. 12 and FIG. 13 are explanatory diagrams for explaining the reason. FIG. 12 is a diagram illustrating the relationship between the device standing time and the toner aggregation degree, and FIG. 13 is a diagram illustrating the relationship between the stirring time by the stirring device and the toner aggregation degree. As shown in FIG. 12, as a general characteristic of the toner, the longer the standing time, the higher the cohesion of the toner. Further, as shown in FIG. 13, the toner once having a high degree of agglomeration also has a property that the degree of agglomeration does not easily fall to a certain level or less even with stirring. Therefore, even if the toner is left for a long time in the power-off state and has a high degree of aggregation, the degree of aggregation is unlikely to be reduced to a certain level or less even if the toner is agitated, and the toner cannot be sufficiently loosened. Therefore, in an image formed using such a toner, an aggregate of the toner appears as a large lump as it is, and a desired image quality cannot be obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of preventing the deterioration of image quality by preventing aggregation of toner when the apparatus is left unattended. It is to provide a device.

[0006]

According to a first aspect of the present invention, there is provided a toner container including a toner container for storing toner and a stirring device for stirring the toner in the toner container. An image forming apparatus for forming an image by using a stirring control means for controlling the stirring device to stir the toner in the toner container at a predetermined timing when the apparatus main body is in a power-off state. It is characterized by the following.

In this image forming apparatus, the stirring control means controls the stirring device so as to stir the toner in the toner container at a predetermined timing when the apparatus main body is off. For example, when there is an instruction from a user or a serviceman, the agitating device is controlled so as to agitate the toner in the toner container at the timing when the instruction is received, or an automatic operation is performed at a preset timing. For example, the stirring device is controlled so as to perform the stirring.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, an input means for inputting a signal for instructing execution of a toner stirring operation by a user or a serviceman when the power of the apparatus main body is turned off. And the stirring control means is configured to perform toner stirring based on a signal from the input means.

In this image forming apparatus, when the power of the apparatus main body is turned off, a user or a service person inputs a signal for instructing execution of the toner stirring operation by the input means, and the signal from the input means is used as a signal. The stirring device is controlled by the stirring control means so as to perform toner stirring based on the toner stirring. More specifically, the agitation control unit controls the toner to be agitated by the agitation device when a signal instructing execution of the toner agitation operation is input to the input unit.

According to a third aspect of the present invention, in the image forming apparatus of the first aspect, the stirring control means is configured to automatically stir the toner by the stirring device. .

In this image forming apparatus, the toner is automatically stirred by the stirring device when the power supply for the apparatus body is turned off by the stirring control means.

According to a fourth aspect of the present invention, there are provided a plurality of toner containers accommodating different toners, and a plurality of agitating devices provided in each of the toner containers and agitating the toner in the toner containers. 3 in the image forming apparatus,
The timing at which the toner is stirred is set for each of the plurality of stirring devices.

In this image forming apparatus, the stirring control means controls the stirring device so as to stir the toner at a timing set for each of the plurality of stirring devices. Thus, the stirring can be performed at a timing suitable for each type of toner.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] An embodiment in which the present invention is applied to an electrophotographic image forming apparatus will be described below. FIG. 1 is a front view illustrating a schematic configuration of the image forming apparatus according to the present embodiment. First, an outline of the entire image forming apparatus will be described. A charging charger 2 as a charging unit is provided around a photoreceptor 1 as a latent image carrier rotating in the direction of an arrow in the drawing.
An exposure device 3, a potential sensor 4, a developing device 5, a reflection density sensor 6, a transfer device 7 for transferring a toner image on the photoconductor 1 onto transfer paper, and the like are provided.

In this image forming apparatus, the surface of the photoreceptor 1 which is driven to rotate in the direction of the arrow in the figure is uniformly charged by the charger 2. A latent image corresponding to the image of the document is formed on the surface of the photoconductor 1 by the exposure device 3 based on an image signal from an image processing unit (not shown).
The latent image on the photoconductor 1 is developed by a developer supplied from a developing roller 51 as a developer carrier of the developing device 5 at a portion facing the developing device 5 to become a visible image. The developing device 5 will be described later in detail. Then, the visible image is fed from a paper feeding device (not shown) at a predetermined timing, and is transferred onto, for example, a transfer paper 8 as a recording member conveyed to a portion facing the photosensitive drum 1 by a transfer roller 71 of a transfer device 7. Is transferred. The transfer paper on which the developed image is transferred is conveyed to a fixing device (not shown), where the developed image is fixed and discharged. Also,
The untransferred toner remaining on the photoconductor 1 after the transfer of the visible image is cleaned from the photoconductor 1 by photoconductor cleaning (not shown). Then, the photoconductor 1 after cleaning
The surface is neutralized by a static elimination lamp (not shown).

FIG. 2 is an explanatory view of a developing device used in the image forming apparatus having the above-described configuration and a toner supply device 9 for supplying the toner T to the developing device. The developing device 5 of the image forming apparatus includes a two-component developer 1 including a toner and a carrier.
0 is used for development. The developing device 5 includes a casing 51 having an opening facing the photoconductor 1, a developing sleeve 52 as a developer carrier for supplying a developer from the opening to the photoconductor 1, It is composed of a stirring roller 53 as a developer stirring means for stirring the developer.

The toner supply device 9 shown in FIG. 2 includes a toner hopper 91 serving as a toner container for accommodating the toner T to be supplied to the developing device, a stirring device for stirring the toner in the toner hopper 91, and the toner in the developing device. It has a toner replenishing screw 93 as a supply means for supplying. The stirring device includes a toner stirring plate 92 as a stirring member for stirring the toner in the toner hopper 91, a drive motor 94 for driving the toner stirring plate 92, and the like.

The toner T in the toner hopper 91 of the toner supply device is supplied into the developing device by a toner supply screw 93. In the developing device, the stirring roller 53 replenishes the developing sleeve 52 with mixing and stirring the developer including the toner and the carrier in the casing 51. The developer supplied on the developing sleeve 52 is regulated to a predetermined thickness, and then is conveyed to a developing area opposite to the photoconductor 1 to develop the electrostatic latent image on the photoconductor 1.

The image forming apparatus further includes a control unit (not shown) having a microcomputer configuration for controlling each unit, which will be described later. The control unit has, as main components, a CPU that executes various arithmetic processes to centrally control each unit, a ROM that stores fixed data, and a RAM that is used as a work area that stores variable data. doing. Further, this image forming apparatus is equipped with a battery dedicated to the control unit so that the control unit functions even when the power of the apparatus main body is turned off, as described later.

FIG. 3 is a block diagram of an electrical unit of the image forming apparatus according to the present embodiment. In this image forming apparatus, when the main switch 501 is turned on, a DC power supply (PSU) that receives an AC power supply from a commercial power supply supplies a DC power supply.
The power supply voltage is supplied to each unit in the apparatus such as the control unit 503 and the drive circuit 504 for driving the drive motor 94. The image forming apparatus employs a configuration in which the stirrer can be driven even when the power for the apparatus main body is turned off, that is, when the main switch 501 is turned off. I have. Specifically, when the main switch 501 is off, a stirring-only battery 505 dedicated to a stirring device serving as a stirring power source for supplying power to a drive motor 94 that rotates the toner stirring plate 92, A stirring power switch 506 is provided as switching means for switching on / off of power supply from the battery 505. Further, a configuration is employed in which the control unit 503 functions even when the main switch 501 is turned off. Specifically, the main switch 501
The control unit dedicated battery 507 as a control power supply for supplying power to the control unit 503 when the power supply is off.
And a control power switch 508 as second switching means for switching on / off of power supply from the control unit dedicated battery 507. The control unit 503 of the image forming apparatus includes a main switch 501
Is turned off, power is supplied to the control unit 503 from the control unit dedicated battery 507, and power supply to the drive motor 94 is supplied to the stirring dedicated battery 50.
5, the control power switch 508 and the stirring power switch 506 are both turned on. Thus, even when the main switch 501 is off, the control by the control unit 503 and the execution of toner stirring by the stirring device can be performed.

In the image forming apparatus according to this embodiment, when the power supply for the apparatus main body is turned off, that is, when the main switch 501 is turned off, there is an instruction from a user or a service person. In some cases, a configuration is employed in which the toner in the toner hopper 91 can be stirred by the toner stirring plate 92. Hereinafter, this configuration and operation will be described in detail. The image forming apparatus has an input unit (not shown) for a user or a serviceman to input a signal for instructing execution of the toner stirring operation when the power of the apparatus main body is turned off. For example, the signal may be configured to be input from the operation panel. Then, the control unit 503 of the image forming apparatus executes the toner stirring mode in which the toner is stirred according to the signal from the input unit at the same time when the power of the apparatus main body is turned off. Hereinafter, the toner stirring mode will be described.

FIG. 4 is a flowchart showing an example of control in the toner stirring mode. In this image forming apparatus, first, when the power of the image forming apparatus main body is turned off, the apparatus enters the toner stirring mode. Next, it is determined whether or not the power of the image forming apparatus main body is currently in an off state (step S1). If it is in the ON state (N in step S1), the toner stirring mode is ended. On the other hand, if it is in the off state (Y in step S1), the control unit 50
3 judges whether or not a signal instructing execution of the toner stirring operation has been input to the input means (step S2). If a signal instructing execution of the toner stirring operation has been input (Y in step S2), control unit 503 executes the toner stirring operation (step S3). In particular,
The toner in the toner hopper is agitated by the toner agitating plate 92 by rotating the drive motor 94 for a certain period of time using the agitating battery as a power source. After the toner stirring operation is performed, the process returns to step S1. If the signal is not input in step S2 (N in step S2), the process returns to step S1.

As described above, when the power of the apparatus main body is off, power is supplied to the stirring apparatus by the dedicated stirring battery, so that the toner in the toner hopper is supplied when the main body of the apparatus is off. Can be stirred. When the power of the image forming apparatus is turned off and the apparatus is left alone, the toner hopper 91 is controlled by executing a toner stirring operation at a timing when an instruction from a user or a serviceman is received at an appropriate time. The toner that has been left to aggregate and starts to aggregate is stirred to prevent aggregation of the toner. As a result, the aggregated toner is prevented from being mixed into the developer and developed on the photoconductor 1, and
High quality images can be obtained by image formation.

As described above, according to the first embodiment, the control unit 50 stirs the toner in the toner hopper at the timing of receiving an instruction from a user or a service person.
Since the control of the stirring device is performed by the step 3, the aggregation of the toner when the device is left can be prevented by a user or a serviceman appropriately giving an instruction to execute the toner stirring. Therefore, it is possible to prevent the deterioration of the image quality.

[Second Embodiment] Next, another embodiment will be described. The basic configuration and operation of the image forming apparatus according to the present embodiment are the same as those of the apparatus according to the first embodiment, and a description thereof will not be repeated. Further, the configuration of the electrical unit of the image forming apparatus according to the present embodiment is the same as that of the apparatus of the first embodiment shown in FIG. Also in this image forming apparatus,
The toner stirring plate 92 is rotated so that the toner in the toner hopper 91 can be stirred by the toner stirring plate 92 even when the power supply for the apparatus main body is turned off, that is, when the main switch 501 is turned off. A dedicated stirring battery 505 is provided as a stirring power supply for supplying power to the drive motor 94. Also in this apparatus, a control unit dedicated battery 507 as a control power supply is mounted so that the control unit 503 functions even when the power supply of the apparatus main body is off. With such a configuration, similarly to the case of the apparatus of the first embodiment, even when the power of the image forming apparatus is turned off and left, the toner agitation operation is performed to prevent toner aggregation and obtain a high-quality image. It has become possible.

In the image forming apparatus according to the present embodiment, when the power for the apparatus main body is turned off, that is, when the main switch 501 is turned off,
A configuration is provided in which a stirring control means for controlling the toner stirring plate 92 so as to automatically stir the toner in the toner hopper 91 is provided. Specifically, the control unit 503
In addition, a function as the stirring control device is provided, and the toner is periodically stirred at a preset timing. And for this, the control unit 503
Has a built-in timer. FIG. 5 is a flowchart illustrating an example of control in the toner stirring mode according to the present embodiment. First, the toner agitation mode is entered when the power of the image forming apparatus is turned off, and the time is set to t = 0, and the timer starts counting (step S1).
1). Next, it is determined whether or not the power supply of the image forming apparatus main body is currently off (step S12). If it is in the ON state (N in step S12), the toner stirring mode is ended. On the other hand, if it is off (Y in step S12), the count of the timer is increased (step S13). Next, whether or not the count t has reached a preset stirring time t1, that is, t ≧ t1
Is determined (step s14). Note that the stirring time t1 is a time interval at which the toner stirring operation is performed. Even if the time t1 is further reduced, no further effect is obtained in preventing toner aggregation. This value is set based on the relationship between the stirring time and the toner aggregation degree shown in FIG. 13, and is stored in the ROM in advance as fixed data. If the count t has not reached the stirring time t1, that is, if t <t1 (step S1
4 and N), and returns to step S12. On the other hand, if the count t has reached the stirring time t1, that is, t ≧ t1
If it is (Y at step S14), the toner stirring operation is executed (step S15). Specifically, as in the first embodiment, the toner in the toner hopper is agitated by the toner agitating plate 92 by rotating the drive motor 94 for a certain period of time using the battery dedicated to agitation as a power source. After the toner stirring operation, the timer is reset, that is, t = 0 (step S16). Thereafter, the process returns to step S1.

As described above, according to the image forming apparatus of this embodiment, when the power is turned off, the toner stirring operation is automatically performed at every predetermined stirring time t1.
This makes it possible to perform the above-described stirring operation more reliably than a user or a service person appropriately instructs execution of the toner stirring operation, to prevent toner aggregation, and to prevent deterioration in image quality. Also, since there is no need to issue an execution instruction from a user or a service person, operability is good.

When the toner stirring operation is performed based on an execution instruction from a user or a service person, the user or service person does not always give the execution instruction at an appropriate timing. On the other hand, in the image forming apparatus according to the present embodiment, the toner agitating operation is automatically performed periodically at a timing previously obtained by an experiment or the like so that the agitating operation can be performed efficiently, so that the toner is reliably and moreover. Thus, the stirring operation can be performed efficiently. As a result, it is possible to prevent a decrease in image quality while suppressing battery consumption. (Hereinafter, margin)

Third Embodiment FIG. 6 is a schematic configuration diagram of an image forming apparatus according to a third embodiment. In the image forming apparatus shown in FIG. 6, a charger (hereinafter referred to as a charging CH) 120 as a charging unit, an exposing device 130, and a Sensor 140 for measuring the surface potential of a black (hereinafter, referred to as Bk) developing device 150Bk, a cyan (Cyan, hereinafter referred to as C) developing device 150C, a magenta (Magenta, hereinafter referred to as M) developing device 150M, and a yellow (Yellow, A developing device 150Y, a reflection density sensor 160 for detecting a development density pattern, an intermediate transfer belt 190, a photoconductor cleaning device 200 for removing toner remaining on the photoconductor 110, and the like are arranged.

Each developing device has a casing (151Bk, 151C, 151C) having an opening facing the photosensitive member 110.
M, 151Y), and a developing sleeve (1) as a developer carrier for supplying a developer (154Bk, 154C, 154M, 154Y) to the photoconductor 110 from the opening.
52Bk, 152C, 152M, 152Y) and a stirring paddle (15) that rotates to pump and stir the developer.
3Bk, 153C, 153M, 153Y).

Hereinafter, the outline of the copy operation will be described with an example in which the order of the development operation (color image formation order) is Bk, C, M, and Y (however, the image formation order is not limited to this). . When the copy operation is started, reading of Bk image data starts at a predetermined timing by a color scanner (not shown), and based on this image data, light writing by a laser beam and formation of a latent image are started (hereinafter, Bk image forming).
An electrostatic latent image based on image data is called a Bk latent image. C, M,
Y is referred to as C latent image, M latent image, and Y latent image, respectively). In order to enable development from the front end of this Bk latent image, Bk
Before the leading end of the latent image reaches the developing position of the developing device 150Bk, the rotation of the developing sleeve 152Bk is started to develop the Bk latent image with Bk toner. Thereafter, the developing operation of the Bk latent image area is continued, and when the rear end of the latent image has passed the Bk developing position, the developing operation is disabled. This is at least
It is completed before the leading end of the C latent image based on the next C image data arrives.

The Bk toner image formed on the photosensitive member 110 is
Intermediate transfer belt 19 driven at the same speed as photoconductor 110
0 (hereinafter, transfer of the toner image from the photoconductor to the intermediate transfer belt is referred to as belt transfer). The belt transfer is performed by applying a predetermined bias voltage to the transfer bias rollers 191 and 192 while the photoconductor 110 and the intermediate transfer belt 190 are in contact with each other. The intermediate transfer belt 190 includes Bk, C,
The M and Y toner images are sequentially aligned on the same surface to form a four-color superimposed belt transfer image, and then collectively transferred to transfer paper.

On the photoconductor 110 side, the process proceeds to the C process after the Bk process. At a predetermined timing, reading of C image data by the color scanner 1 starts, and a C latent image is formed by writing a laser beam based on the image data. The C developing device 150C starts rotating the developing sleeve with respect to the developing position after the trailing end of the previous Bk latent image has passed and before the leading end of the C latent image has arrived. Develop with toner. Thereafter, the development of the C latent image area is continued, and when the rear end portion of the latent image has passed, the development is disabled as in the case of the Bk developing device. This is also completed before the leading end of the next M latent image arrives. In each of the steps M and Y, the operations of reading image data, forming a latent image, and developing are performed in the same manner as the steps Bk and C described above.

The transfer paper 180 onto which the four-color superimposed toner image has been transferred from the intermediate transfer belt surface is conveyed to a fixing device (not shown), where the toner image is melted and fixed and discharged.

The surface of the photoconductor 110 after the belt transfer is cleaned by the photoconductor cleaning device 200. Then, the surface of the photoreceptor 1 after cleaning is subjected to residual charge removal by a charge removal lamp (not shown). Further, the surface of the intermediate transfer belt 190 after the transfer of the toner image onto the transfer paper 180 is cleaned by a belt cleaning device (not shown).

At the time of repeat copying, the operation of the color scanner and the formation of an image on the photosensitive member 110 are performed on the first sheet Y.
(Fourth color) After the image process, 2
The process proceeds to the Bk (first color) image process for the sheet. In the case of the intermediate transfer belt 190, the second Bk toner image is transferred to the area whose surface has been cleaned by the belt cleaning device, following the batch transfer process of the first four-color superimposed image onto transfer paper. Be transferred. After that, the operation is the same as that of the first sheet.

The above is a description of the copy mode for obtaining four full colors. However, in the case of the three-color copy mode and the two-color copy mode, the designated colors and the number of times are the same as described above. Will be performed.

Next, a description will be given of the toner hopper unit 300 as toner supply means for supplying toner to each of the developing devices. FIG. 7 is a schematic configuration diagram of the toner hopper unit 300. This toner hopper unit 300
Are the toner hopper unit 300Bk for the Bk developing device 150Bk, the toner hopper unit 300C for the C developing device 150C, the toner hopper unit 300M for the M developing device 150M, and the toner hopper unit 300Y for the Bk developing device 150Bk. Have.

Since the construction of each toner hopper unit (300Bk, 300C, 300M, 300Y) is substantially the same, a Bk developing device 150B will be described below.
The description will be made by taking the toner hopper unit 300Bk for k as an example.

The toner hopper unit 300Bk has a toner replenishing port 301a for replenishing the replenishing toner TBk formed at an upper portion thereof, a toner hopper 301Bk as a toner container for storing the replenishing toner TBk, and a toner hopper 301Bk stored inside the toner hopper. And a stirring device for loosening and stirring the toner TBk. The stirring device rotates the toner hopper 301Bk while stirring the toner in the toner hopper 301Bk.
2 is constituted by a drive motor 94Bk (not shown) for driving the rotation of the motor 2. The toner stirring plate 302 has a plurality of stirring blades 302a as shown in FIG. Further, a toner supply screw 303B is provided below the toner stirring plate 302Bk of the toner hopper unit 300Bk.
k is provided.

In this image forming apparatus, the toner TBk in the toner hopper 301Bk is supplied into the developing device by a toner supply screw 303Bk. In the developing device, the stirring roller 153Bk mixes and stirs the developer 154Bk including the toner and the carrier in the casing 151Bk while stirring.
Supply on Bk. After the developer 154Bk supplied on the developing sleeve 152Bk is regulated to a predetermined thickness,
The sheet is conveyed to a developing area opposite to the photoconductor 110 and develops the electrostatic latent image on the photoconductor 110 as described above.

The image forming apparatus also has a control unit (not shown) having a microcomputer configuration for controlling each unit, which will be described later, as in the case of the image forming apparatuses of the first and second embodiments. The control unit has, as main components, a CPU that executes various arithmetic processes to centrally control each unit, a ROM that stores fixed data, and a RAM that is used as a work area that stores variable data. doing.

FIG. 9 is a block diagram of the electrical unit of the image forming apparatus according to this embodiment. In this image forming apparatus, when the main switch 501 is turned on, a DC power supply (PSU) that receives an AC power supply from a commercial power supply supplies a DC power supply.
The power supply voltage is set to the control unit 503 and the four toner hoppers 3
01Bk, 301C, 301M, and 301Y, the toner stirring plates 302Bk, 302C, and 3 provided respectively.
Drive motor 94 for rotating 02M and 302Y respectively
Bk, 94C, 94M, and 94Y are configured to be supplied to each unit in the apparatus such as a drive circuit 504 for driving. In this image forming apparatus, the four toner hopper units 300Bk, 300C, 300M, and 300M are also in a state where the power supply for the apparatus main body is turned off, that is, when the main switch 501 is turned off.
A configuration capable of driving a 300Y stirring device is employed. Specifically, the main switch 501
Is off, the toner stirring plates 302Bk and 302Bk
C, a dedicated stirring battery 505 serving as a stirring power source for supplying power to the drive motors 94Bk, 94C, 94M, and 94Y for rotating the 302M, 302Y, respectively, and a power supply from the dedicated stirring battery 505. A stirring power switch 506 as switching means for switching on and off. Further, a configuration is employed in which the control unit 503 functions even when the main switch 501 is turned off. Specifically, when the main switch 501 is off, the control unit dedicated battery 507 as a control power supply for supplying power to the control unit 503 and the power supply from the control unit dedicated battery 507 are turned on. Control power switch 508 as second switching means for switching off
And Then, the control unit 5 of the image forming apparatus
03 is when the main switch 501 is turned off,
The control power switch 508 and the stirring power switch 506 are configured to supply power to the control unit 503 from the control unit dedicated battery 507 and to supply power to the driving motor 94 from the stirring dedicated battery 505.
Are turned on. Thus, even when the main switch 501 is off, the control by the control unit 503 and the execution of toner stirring by the stirring device can be performed. With such a configuration, when the image forming apparatus is turned off and left as it is, the toner agitation operation is performed to prevent toner aggregation, and a high-quality image can be obtained.

In the image forming apparatus according to the present embodiment, the power supply for the apparatus main body is turned off, that is, the main switch 501 is turned off for each of the stirring devices of the plurality of developing devices. sometimes,
A configuration is provided in which a stirring control unit that individually controls such that the toner in the toner hopper 91 is stirred is provided. Specifically, the control section 503 has a function as the stirring control means. More specifically, a predetermined timing for stirring the toner is set for each of the plurality of, that is, four toner types, specifically, for each of the stirring devices corresponding to the four types of Bk, C, M, and Y, The timer for each of the four toner types is built in the control unit 503. Hereinafter, the control by the control unit 503 will be described in detail. FIG.
0 is a flowchart illustrating an example of control in the toner stirring mode according to the present embodiment. First, the toner agitation mode is entered when the power of the image forming apparatus of the image forming apparatus is turned off.
0, C count value tc = 0, M count value tm =
Assuming that the count values ty of 0 and Y are ty = 0, the timers respectively corresponding to the above four types of toner start counting (step S101). Next, it is determined whether or not the power supply of the image forming apparatus main body is currently off (step S102). If it is in the ON state (step S
In N), the toner stirring mode is ended. On the other hand, if it is off (Y in step S102), the counts tk, tm, tc, and ty of the respective timers are increased (step S103). And first, the count t of Bk
It is determined whether or not k has reached the preset stirring time tk of Bk, that is, whether or not tk ≧ tk1 is satisfied (step S104). The stirring time tk will be described later. Count tk in step S104
Has reached the stirring time tk1, that is, tk
If ≧ tk1 (Y in step S104), the toner stirring operation in the Bk toner hopper 301Bk is executed (step S105). Specifically, the drive motor is rotated for a certain period of time using the dedicated stirring battery as a power source, so that the toner hopper 3 is driven by the toner stirring plate 302Bk.
Stir the toner in 00Bk. Then, after the toner stirring operation is performed, the timer of Bk is reset, that is, tk is set to 0 (step S106). Thereafter, the process proceeds to step S107. On the other hand, if the count tk has not reached the stirring time tk1 in step S104, that is, if tk <tk1 (N in step S104), the process directly proceeds to step S107.

Thereafter, for C, M, and Y, similarly to the case of Bk, whether the counts tc, tm, and ty of C, M, and Y have reached the stirring times (tc1, tm1, and ty1), respectively. Execute the toner stirring operation in the C, M, and Y toner hoppers, reset the respective counts,
Proceed to the next step. If the count ty has not reached the yellow stirring time ty1 in step S113, that is, if ty <ty1 (step S113)
N) or reset the yellow timer in step S115, and then return to step S102 again.

The stirring times tk1, tc1, t
m1 and ty1 are time intervals at which the toner stirring operation is performed for each of Bk, C, M, and Y toners. is there. These values are shown in FIG.
Is set based on the relationship between the agitation time and the toner aggregation degree obtained for each of the Bk, C, M, and Y toner types shown in FIG.
It is stored as fixed data in the OM.

As described above, according to the third embodiment, when the power of the apparatus is turned off, the toner is stirred at the timing set for each toner type. This makes it possible to economically prevent toner aggregation while minimizing battery consumption, thereby preventing deterioration in image quality.

In the first to third embodiments,
Although only an example in which the present invention is applied to an image forming apparatus provided with a developing device 5 that performs development using a two-component developer has been described, a developing device that performs development using a one-component developer containing toner is provided. The present invention is applicable to an image forming apparatus.

[0049]

According to the first to fourth aspects of the present invention, the image quality is prevented from deteriorating by performing toner stirring operation at a predetermined timing when the apparatus is left to prevent aggregation of the toner when the apparatus is left. There is an excellent effect that you can.

According to the second aspect of the present invention, the toner agitation is performed when the user or a serviceman instructs the toner agitation operation, so that the aggregation of the toner when the apparatus is left unattended can be prevented. Thereby, there is an excellent effect that deterioration of image quality can be prevented.

According to the third aspect of the present invention, the toner in the toner container is automatically stirred by the stirring control means. There is an excellent effect that aggregation can be prevented to prevent deterioration in image quality. Further, since the stirring is performed automatically, there is also an excellent effect that operability is good. Furthermore, if the toner is periodically stirred at a timing determined in advance by an experiment or the like so that the stirring operation can be performed efficiently, the toner can be efficiently and economically aggregated to prevent deterioration of image quality. There is an effect that can be.

In particular, according to the fourth aspect of the present invention, since the stirring can be performed at a timing suitable for each type of toner, the stirring operation can be performed more efficiently than when the stirring operation is simultaneously performed on each of the plurality of toners. There is an excellent effect that it is possible to economically prevent toner agglomeration and prevent deterioration of image quality.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a schematic configuration of an image forming apparatus according to an embodiment.

FIG. 2 is an explanatory diagram of a developing device and a toner supply device in FIG. 1;

FIG. 3 is a block diagram of an electrical unit of the image forming apparatus.

FIG. 4 is a flowchart illustrating an example of control in a toner stirring mode of the image forming apparatus.

FIG. 5 is a flowchart illustrating an example of control in a toner stirring mode of an image forming apparatus according to another embodiment.

FIG. 6 is a schematic configuration diagram of an image forming apparatus according to still another embodiment.

FIG. 7 is a schematic configuration diagram of a toner hopper unit of the image forming apparatus.

FIG. 8 is an explanatory diagram of a toner stirring plate of the toner hopper unit.

FIG. 9 is a block diagram of an electrical unit of the image forming apparatus.

FIG. 10 is a flowchart illustrating an example of control in a toner stirring mode of the image forming apparatus.

FIG. 11 is a diagram illustrating a relationship between a stirring time and a toner aggregation degree obtained for each of Bk, C, M, and Y toner types.

FIG. 12 is a diagram illustrating the relationship between the device standing time and the degree of toner aggregation.

FIG. 13 is a diagram illustrating a relationship between a stirring time by a stirring device and a degree of toner aggregation.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor 2 charging charger 3 exposure device 4 potential sensor 5 developing device 6 reflection density sensor 7 transfer device 8 transfer paper 9 toner supply device 91 toner hopper 92 toner stirring plate 93 toner supply screw 94 drive motor

Claims (4)

[Claims] 1. An image forming apparatus, comprising: a toner container for accommodating a toner; and a stirring device for stirring the toner in the toner container, wherein an image is formed using the toner. And an agitating control means for controlling the agitating device so as to agitate the toner in the toner container at a predetermined timing. 2. An image forming apparatus according to claim 1, further comprising: input means for inputting a signal for instructing execution of a toner stirring operation by a user or a serviceman when the apparatus main body is turned off. An image forming apparatus, wherein the stirring control unit is configured to stir the toner based on a signal from the unit. 3. The image forming apparatus according to claim 1, wherein said stirring control means is configured to automatically stir said toner by said stirring device. 4. The image forming apparatus according to claim 3, further comprising: a plurality of toner containers accommodating different toners; and a plurality of agitating devices provided in each of the toner containers and agitating the toner in the toner containers. 2. The image forming apparatus according to claim 1, wherein a timing for stirring the toner is set for each of the plurality of stirring devices.