JPH09166903A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a developing unit from being continuously rotated in a state where a toner container is not loaded on a developing device, by controlling so that the rotation of the developing unit may be stopped at a point of time when it is judged by a discriminating means that a detachable container does not exist. SOLUTION: The developing unit 40 is rotated by 90 deg. up to every developing position of each developing unit, and it is detected whether or not the toner container is loaded on a toner container unit 45 which is rotated with the developing unit 40. Then, light emitted from each light emitting part is reflected by a filler 302, and whether or not the light is received by the light receiving part is detected by a detecting sensor 303. Based on the detection results, it is discriminated by the discriminating means which color toner container exists, or whether or not the toner container is loaded, and in the case of discriminating that the toner container is not loaded, the rotation of the developing unit 40 is stopped by a control means.

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.
A developing device unit having a plurality of developing devices arranged around the rotation center line is rotated about the rotation center line, and an arbitrary developing device is set at a developing position facing the latent image carrier and the latent image carrier is set. An image having a rotary developing device for developing a latent image on an image carrier and a detachable toner container detachably attached to each developing device and rotatable together with the developing device unit. The present invention relates to a forming device.

[0002]

2. Description of the Related Art Conventionally, as a developing device used in an image forming apparatus, a developing device unit having a plurality of developing devices arranged around a rotation center line is rotated around the rotation center line to obtain an arbitrary device. There is known a rotary developing device in which a developing device is set at a developing position facing a latent image carrier to develop a latent image on the latent image carrier. The developing device unit of such a rotary developing device is provided with a toner container that contains toner for replenishing toner to the developing device of the developing device unit. As the toner container, a fixing method is proposed in which the toner container is provided separately from the developing device unit, only the developing device unit rotates, and the toner container is fixed to the developing device. There is. In this fixing method, toner is replenished from the fixed toner container to each developing device through a supplementary auxiliary means such as a pipe at a replenishing position where toner is replenished from a toner container corresponding to each developing device. Even if the toner capacity that can be accommodated in the toner container is increased, there is an advantage that it is not necessary to change the size of the replenishment assisting device itself. However, since the replenishment assisting means side is fixed, while the developing device side is movable, it is possible to prevent toner spillage from portions where the toner replenishment openings formed in the toner container and the developing device come into contact with each other. However, there is a problem that the developing devices cannot be shared if the replenishing ports of the developing devices are provided at different positions in order to surely replenish the toner of each color to each developing device. It was In addition, there is a problem that special means must be provided in order to prevent toner aggregation inside the toner container with time. Also,
In terms of downsizing of the device, the toner container requires a dedicated installation location in the device, and thus it becomes difficult to allocate the installation space when increasing the toner capacity that can be stored in the toner container. There was also a problem. Therefore, as a means for solving the above-mentioned problems, there has been proposed a rotation system in which a toner container is provided integrally with a developing device unit and rotates integrally with the developing device unit. In this rotation type toner container, unlike the above-mentioned fixed type toner container, the replenishment port of each developing device and the replenishment port of the toner container are always opposed to each other in a one-to-one manner. The toner is not spilled from the replenishing port when it is mounted in the developing device, and the replenishing port can be provided at the same position in each developing device, which can be shared. Further, since the toner container rotates together with the developing device unit, it is possible to prevent toner aggregation inside the toner container without providing a special stirring means. When the toner container is integrated with the developing device unit, the amount of toner that can be stored in the toner container is limited as compared with the fixed toner container. By configuring the toner container into a cartridge type that can be attached to and detached from each of the developing devices of the developing device unit, and by making the size of the toner container small enough to accommodate it, the remaining amount of toner in the toner container is reduced. When there is a shortage, the operator can easily replace the toner container to solve the problem.

[0003]

However, according to the developing device unit adopting the above-mentioned rotary type toner container,
When the toner container is removable with respect to each developing device of the developing device unit, if the developing device unit is continuously rotated while the toner container is not attached to the developing device,
There is a problem in that toner may spill from the toner supply opening of the developing device to which the toner container is not attached. When such a toner spill occurs, not only the inside of the apparatus is contaminated with the toner, but also when the toner spills on the conveyance path of the transfer material, the image quality is deteriorated. Further, if the toner spills in the vicinity of the fixing portion, the toner is melted by the heat in the vicinity of the fixing portion, and the melted toner increases the friction with the transfer material conveyed to the fixing portion, causing the transfer material to be clogged. There was a problem that it would end up.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the developing device unit from being continuously rotated in a state where the toner container is not attached to the developing device, To provide an image forming apparatus equipped with a rotary developing device capable of preventing toner from accidentally spilling from the inside of a developing device to which a toner container is not attached when the developing device unit is continuously rotated. That is.

[0005]

In order to achieve the above object, the invention of claim 1 provides a developing device unit having a plurality of developing devices arranged around the rotation center line, around the rotation center line. Rotation type developing device that rotates and sets an arbitrary developing device at the developing position facing the latent image carrier to develop the latent image on the latent image carrier, and is attachable to and detachable from each of the developing devices. In the image forming apparatus having the detachable toner container configured to be rotatable together with the developing device unit, the presence / absence of the detachable toner container is detected at a predetermined position which is sequentially reached as the developing device unit rotates. A toner container detecting means that is arranged as much as possible, a first controlling means that rotates the developing device unit before the developing operation, and a first controlling means that rotates the developing device unit once,
Based on the detection result detected by the toner container detecting unit, a determining unit that determines the presence or absence of the removable toner container, and a time point when the determining unit determines that there is no removable toner container, A second control means for controlling the rotation of the developing device unit to stop is provided.

According to a second aspect of the present invention, a developing device unit having a plurality of developing devices arranged around a rotation center line is rotated about the rotation center line, and an arbitrary developing device is used as a latent image carrier. A rotary developing device which is set at a developing position facing each other and develops the latent image on the latent image carrier, and is attachable to and detachable from each of the developing devices and rotatable with the developing device unit. In the image forming apparatus having the detachable toner container, the first toner container detecting means is arranged so as to be able to detect the presence or absence of the detachable toner container at a predetermined position which is sequentially reached as the developing device unit rotates. When,
A second toner container detecting means provided at a predetermined position other than the position where the first toner container detecting means is provided; and a second toner container rotating means for rotating the developing device unit in a predetermined rotation direction by a predetermined angle before the developing operation. One control unit and the removable toner accommodating unit based on the detection results detected by the first toner container detecting unit and the second toner container detecting unit while the control unit rotates the developing unit. And a second control unit for controlling the rotation of the developing device unit when the determination unit determines that there is no removable toner container. It is a feature.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, after the detection by the toner container detecting means is completed, all the toner containers are set in the respective developing devices by the determining means. If it is determined that the developing device is rotating, the control means for controlling the rotation of the developing device is provided so as to rotate the specific developing device to the developing position.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first or second aspect, at least one of the toner accommodating containers is provided with a discriminating section capable of discriminating that it is a predetermined toner accommodating container. In addition to the above, the determination means for identifying the developing device corresponding to the toner container having the determination portion is provided.

According to a fifth aspect of the present invention, in the image forming apparatus according to the first or second aspect, when the determination means determines that the toner container is not present, a display means for displaying that is provided. It is a feature.

If a plurality of toner containers are removed from the developing unit of the developing unit unit at the time of replacing the toner container, different toner containers may be mounted at the time of mounting.

Therefore, according to the invention of claim 6, in the image forming apparatus according to claim 1 or 2, the toner accommodating device which covers the detachable toner accommodating container so as to have an opening to which only one accommodating container is detachable. A vessel cover member is provided, and
The toner container detecting means of the above or the position of the first toner container detecting means of claim 2 is set in the vicinity of the opening of the toner container cover member.

According to the first aspect of the invention, the toner container detecting means detects the presence or absence of the detachable toner container while the developing device unit is rotated once by the control signal of the first control means. And, based on this detection result,
The determining means determines whether or not the removable toner container is present.
Then, when the determining unit determines that the removable toner container is not present, the second control unit stops the rotation of the developing device unit. This prevents toner spillage that occurs when the removable toner container is kept rotating without being attached to a predetermined developing device. Further, the number of the detecting means can be reduced as compared with the case where a plurality of detecting means are arranged on the outer circumference of the rotation of the toner containing means and the presence or absence of the toner containing means is detected.

Further, in the invention of claim 2, the developing device unit is rotated to a predetermined position by the control signal of the first control means, and the first toner container detecting means and the second toner container provided at the predetermined position are provided. The presence or absence of the removable toner container is detected by the toner container detection means. Then, based on these detection results, the determination unit determines the presence / absence of the removable toner container. Then, when the determining unit determines that the removable toner container is not present, the second control unit stops the rotation of the developing device unit. This makes it difficult to cause toner spillage that occurs when the removable toner container is continuously rotated without being attached to a predetermined developing device. Further, since the presence / absence of two developing devices can be simultaneously detected by the first toner container detecting means and the first toner container detecting means, as compared with the case of detecting the presence / absence by one detecting means. Therefore, the presence or absence of all removable toner containers can be detected with a small rotation of the developing unit.

According to the third aspect of the present invention, when it is determined by the determination means that all the toner containers are set in the respective developing devices, the control device always moves the specific developing device to the developing position. Rotate the developer unit so that As a result, the time required to form the first image can be shortened as compared with the case where a predetermined developing device is moved to the developing position at the start of development. Further, the image forming condition is always constant as compared with the case where the development is performed from the color of the developing device at the developing position after the detection.

According to another aspect of the present invention, the discriminating means capable of specifying the developing device corresponding to the toner container is a predetermined toner container in at least one of the toner containers. The determination unit that enables determination is determined.
This makes it possible to easily set the specific developing device at the specific position based on the positional relationship with the developing device to which the toner container having the determination unit is attached.

In the invention of claim 5, when the display means determines that the toner container is not present, the display means displays that effect. This makes it possible for the operator to know that the toner container is not attached to the developing device of the predetermined color.

According to the sixth aspect of the invention, the toner accommodating cover member that covers the detachable toner accommodating container so as to have an opening to which only one toner accommodating container can be attached and detached is rotated by detecting the toner accommodating container. Thus, even if toner spills from the developing device to which the detachable toner container is not attached, the toner is prevented from scattering to the outside of the cover member. (Hereinafter, margin)

[0018]

DETAILED DESCRIPTION OF THE INVENTION An embodiment in which the present invention is applied to a color electrophotographic printer (hereinafter referred to as a printer) which is an image forming apparatus will be described below. FIG. 1 is a schematic configuration diagram of a printer according to the present embodiment. The printer unit shown in FIG. 1 is roughly composed of a photosensitive drum 1 as a latent image carrier, a rotary developing device 4, a developing device unit 40, an intermediate transfer belt 5, and a writing system unit 3 as a laser optical device. Has been done.

FIG. 2 is a schematic configuration diagram showing a main part of the printer section shown in FIG. Around the photosensitive drum 1, a charge eliminating lamp (hereinafter, QL) 18 for erasing the residual charge on the photosensitive drum 1, a charger (hereinafter, charging CH) 2 as a charging unit, and a photosensitive drum 1 on the photosensitive drum 1. Sensor 14 for reading the image density of the intermediate transfer belt 5
A belt transfer charger 6 for giving a predetermined charge to the
A drum cleaning device 13 for removing the toner remaining on the photosensitive drum 1 is provided. Both the photosensitive drum 1 and the intermediate transfer belt 5 are rotationally driven by a drum motor (not shown).

The inside of the developing device unit 40 which is in contact with the photosensitive drum 1 is divided into four parts, and the developing devices of four colors of yellow (Y), magenta (M), cyan (C) and black (K) are provided. 21K, C, M and Y are arranged.
Further, cylindrical developing sleeves 22K, C, M and Y as a developer carrying member are rotatably supported on the developing devices 21K, C, M and Y, respectively. The developing sleeve 22 is driven to rotate by a developing motor (not shown). The developing position of the developing unit 40 is the charging C on the photosensitive drum 1.
It is located between the H2 and the P sensor 14, and in FIG.
The state where the developing device 21K is in the developing position is shown. The developing device unit 40 is rotationally driven in the direction of arrow C by a developing device unit motor (not shown). Further, the developing device unit motor is rotationally controlled by a control unit (not shown) to stop the development color of the designated color at the development position.

The writing system unit 3 includes a polygon mirror 3c and an fθ lens 3 which are rotated by a polygon motor.
It is composed of optical components such as a, 3b and a mirror 3d. Then, a laser beam generated by an LD (laser diode) (not shown) is rotationally scanned by the polygon mirror 3c, passes through the fθ lenses 3a and 3b, and then the mirror 3d.
Thus, the optical path is bent by the exposure, and exposure is performed between the charging position CH2 on the photosensitive drum 1 uniformly charged by the charging CH2 and the developing position.

On the other hand, around the intermediate transfer belt 5, a belt mark sensor 15 provided inside the belt for reading a reference mark 16 which serves as a reference for alignment during color superposition, and a lubricant is applied to the intermediate transfer belt 5. A lubricant application unit 32, a paper transfer charger 33 for transferring an image transferred on the intermediate transfer belt 5 to a transfer paper (not shown), and a belt for cleaning untransferred toner and residual toner on the intermediate transfer belt 5. A cleaning unit 34 is provided. The circumference of the intermediate transfer belt 5 is set to be longer than the sum of the maximum image size and the pattern area of the P sensor 17 (including the distance from the rear end of the image and the pattern margin length). Further, the belt cleaning unit 34 is configured to be able to come into contact with and separate from the intermediate transfer belt 5 by an intermediate transfer belt cleaning solenoid (not shown). Further, the application of the lubricant is configured such that it can be brought into and out of contact with the intermediate transfer belt 5 by a lubricant application solenoid (not shown), and it is possible to apply or not apply the application.

Further, upstream of the paper transfer charger 33,
A registration roller 9 is provided, and a transfer paper transport belt 11 and a fixing device 12 are provided on the downstream side. Of these, the registration roller 9, the conveyor belt 11, and the fixing roller of the fixing device 12 are rotationally driven by the above-mentioned main motor. Further, the registration roller 9 is turned on / off by a registration clutch (not shown).

In the structure of FIG. 2 described above, the photosensitive drum 1 is uniformly charged by the charging CH2 while being rotationally driven in the direction of the arrow A, and then scanned and exposed by the writing system unit 3 based on the image information. An electrostatic latent image is formed on the surface. Here, the image information to be exposed is black image information for a single color, and monochromatic image information obtained by decomposing a desired full-color image into yellow, magenta, cyan, and black color information for a full color. is there. Further, the electrostatic latent image formed on the photosensitive drum 1 is developed by the developing device unit 40 with yellow, magenta, cyan, and black toners as predetermined developers, respectively. An image of each color is formed.

On the other hand, each color image formed on the photoconductor drum 1 is formed of yellow, magenta, cyan, and black on the intermediate transfer belt 5 which rotates in the direction of arrow B in the figure in synchronization with the photoconductor drum 1. Belt transfer charger 6 for each single color
Are sequentially overlaid and transferred. The yellow, magenta, cyan, and black images superimposed on the intermediate transfer belt 5 are transfer paper (not shown) conveyed from the paper feed tray 7 through the paper feed roller 8 and the registration roller 9, or a manual paper feed tray. A sheet transfer charger 33 collectively transfers the sheet 7a onto a sheet of transfer paper (not shown) that has been conveyed through a sheet feeding roller 8a and a registration roller 9. After the transfer is completed, the transfer paper is transferred to the fixing device 1 shown in FIG.
Then, the toner image is fixed and discharged to the outside of the apparatus as a full-color print.

The toner on the photosensitive drum 1 that has not been transferred onto the intermediate transfer belt 5 is removed from the photosensitive drum 1 by the drum cleaning device 13 and is not transferred onto the transfer paper (not shown). Belt 5
The upper toner is removed from the intermediate transfer belt 5 by the belt cleaning unit 34.

Next, the rotary developing device according to the embodiment of the present invention will be described. 3 is an exploded perspective view of the developing device, FIG. 4 is a cross-sectional view showing the internal structure of the developing device unit 40 of the developing device, and FIG. 5 includes the central shaft 52 of the upper and lower conveying screws 86, 91 of the black developing device. 6 is a vertical cross-sectional view taken along a plane, FIG. 6 is a cross-sectional view showing the internal structure of the toner container unit 45, and FIG. 7A is a front view of the black toner container.
8B is a plan view of the same container, and FIG. 8 is a perspective view of the color toner container and the container mounting portion.

In FIG. 3, the rotary developing device has a developing device for each of four colors of black, cyan, yellow, and magenta formed therein, and is attached to the outer periphery of the printer body so as to be rotatable about a central axis. Holds a substantially cylindrical developing device unit 40, and four toner containers 41, 42, 43, 44 which respectively correspond to the developing devices in a one-to-one relationship and which respectively store black, yellow, magenta, and cyan toners, and A toner container unit 45 that is mounted so as to be substantially coaxial with the front side of the developing unit unit 40 in the central axis direction and that rotates integrally with the developing unit 40 about the central axis, and these developing unit units 40. And a toner container unit 45 (hereinafter referred to as a revolver developing unit) carried on the printer main body substantially parallel to the central axis. A ride can accommodate base 46 and a cover 47 provided non-rotatably covering the rotary supply unit.

The revolver developing unit is provided with a receiving table 46.
Rotatably attached to the front support plate 48 of, for example, 2
One support roller 49 supports the disk-shaped front end wall 50 of the developing device unit 40, and the central axis 5 of the tip taper projectingly provided at the center of the disk-shaped rear end wall 51 of the developing device unit 40.
2 is rotatably supported by the central shaft insertion hole 54 formed in the rear plate 53 of the main body, so that the rotation axis of the printer 2 becomes the rotation axis of the photosensitive drum 1 in the printer main body as shown in FIG. They are positioned so as to be parallel to each other in substantially the same horizontal plane and are rotatable.

The housing base 46 has a front support plate 48, a rear support plate 55, and a side cover 59 having front and rear end portions fixed to both support plates and reinforced by connecting rods 56, 57 and 58.
And An insertion hole 60 into which the revolver developing unit can be inserted is formed in the front support plate 48, and in addition to the support roller 49, a motor 61 for driving a toner replenishing roller provided in the toner container unit 45 and the motor 61. A gear train 62 driven by a motor 61 is attached.
An intermediate plate 63 is attached to the connecting rods 56 and 57 in the vicinity of the rear support plate 55, and a positioning pin 63b that fits into a positioning hole 63a formed in the rear plate of the main body is protruded from the intermediate plate 63. Has been done. A base end portion of a bracket 64 holding a rotary positioning roller 66 is swingably attached to a positioning pin portion between the middle plate 63 and the rear support plate 55. The bracket 64 is formed on the peripheral surface portion of the rear end wall 51 of the developing device unit at a predetermined position of the roller 66 to form a total of four members for positioning each developing device at the developing position.
It is biased by a spring 67 in such a direction that it is fitted into one recess 65.

The front plate 68 of the main body is formed with an insertion hole 69 or the like into which the receiving base 46 carrying the revolver developing unit can be inserted, and between the front side plate 68 of the main body and the rear plate 53 of the main body. Upper and lower guides 70, 71 for slidably supporting the storage base 46 are hung. Guided portions 72 and 73 are provided at the upper end and side portions of the storage table side cover 59 as the receiving table portion guided by these guides 70 and 71, and the lower surface portion of the guided portion 73 on the side of these is provided. A guide pin groove 75 into which the guide pin 74 that is planted upward in the guide 71 is inserted is formed in the.

A revolver output gear 78, which is driven by a revolver rotation motor (not shown) such as a stepping motor, is mounted on the rear plate 53 of the main body. The revolver output gear 78 is mounted on the rear plate 53.
0 is meshed with a revolver input gear 79 having a diameter substantially the same as that of the rear end wall 51 fixed to the rear surface of the rear end plate by screwing or the like,
The revolver developing unit is driven to rotate. The rear plate 53 of the main body has a developing unit 4 which will be described later.
A developing output gear 81 driven by a developing drive motor (not shown) for driving the developing roller in 0 is also attached.

In FIG. 4, the developing device unit 40 includes the above-mentioned substantially disc-shaped front and rear end walls and a partition wall provided between the front and rear end walls. The partition wall includes a hollow cylindrical portion 82 into which a cylindrical black toner bottle containing black toner can be inserted, and a space around the hollow cylindrical portion 82 extending radially from the hollow cylindrical portion 82 so as to be substantially circumferential to each other. Developing device casings 83, 8 partitioned into four developing chambers of the same type
3C, 83M, and 83Y. Each of these developing chambers contains a carrier as a developer and a two-component developer including toner of each color. In the example shown in the drawing, the developing chamber of the black developing device containing the black toner and the carrier is located at the developing position opposed to the photosensitive drum, and the developing device of the yellow developing device containing the yellow toner and the carrier is arranged in the counterclockwise direction in the figure. A developing chamber is a developing chamber of a magenta developing device containing magenta toner and a carrier, and a developing chamber of a cyan developing device containing cyan toner and a carrier.

Since the internal structures of the four developing chambers are exactly the same, the internal structure will be described below by taking the black developing chamber in the developing position in FIG. 4 as an example, and the internal structures of the other developing chambers. Are the same reference numerals as the corresponding reference numerals in the black developing chambers, but with the suffixes Y, M, and C added to distinguish the yellow, magenta, and cyan developing chambers from each other. To do.

In the black developing device at the developing position in the figure, an opening portion facing the photosensitive drum 1 is formed in the developing device casing portion 83, and a part is exposed through the opening portion in the developing chamber. A developing roller 84 is provided. In the developing chamber, a doctor blade 85 that regulates the amount of developer carried by the developing roller 84 and conveyed to the portion facing the photosensitive drum 1, and the developing blade regulated by the doctor blade 85 and pressed into the developing chamber. An upper transport screw 86 for transporting a part of the developer along the central axis direction from the rear to the front, a guide 87 thereof, and a stirring paddle 88 for stirring the developer in the developing chamber are provided. The stirring paddle 88 has a plurality of developer discharge holes 89a over the width direction of the developing roller 84.
Are formed, and a plurality of agitating plate portions 90 radially extending from the peripheral surface of the hollow cylindrical portion 89, and the upper conveying portion is provided in the hollow cylindrical portion 89 along the center axis direction. A lower transport screw 91 that transports the developer in a direction opposite to that of the screw 86 is accommodated. The developer casing below the lower transport screw 91 is provided with a developer discharge port used as a discharge port for a deteriorated developer or an input port for unused developer (toner mixed) when a developer is replaced due to deterioration of development in the developing chamber. An outlet 92 is formed. The discharge port 92 is covered from the outside by a cap 93 attached with a screw 94.

In FIG. 5, the vertical transport screws 86,
The front end of 91 is outside the effective width region of the developing roller 84 (in the example shown, outside the front end wall 50 of the developing unit).
A drop portion 96 for extending the developer conveyed by the upper conveying screw 86 to the lower conveying screw 91 by its own weight is provided at this extending portion. The front end of the lower transport screw 91 extends further to the front side than the drop portion 96, and toner replenishment as a developer supply member provided corresponding to each developing chamber of the toner container unit 45 described later in detail. It extends into the communication chamber below the roller 97. As a result, of the developer drawn up by the developing roller 84, the developer regulated by the doctor blade 85 and conveyed to the front side by the guide 87 and the upper conveying screw 86 is moved to the lower side by the dropping portion 96.
Then, the developing roller 84 is dropped by the lower conveying screw 91.
Of the agitating paddle hollow cylindrical portion 89 within the effective width, is discharged into the developing chamber from the developer discharge port of the stirring paddle hollow cylindrical portion 89, and can be carried by the developing roller 84 again. That is, so-called horizontal stirring of the developer in the developing chamber is performed. Then, the developer discharged from the developer discharge port of the hollow cylindrical portion 89 of the stirring paddle 88 to the developer pool below the developing chamber is stirred paddle 88.
The so-called vertical stirring is performed by the rotation of the stirring plate. Further, the toner dropped on the lower conveying screw 91 in the communication chamber by the rotation of the replenishing roller 97 is conveyed by the lower conveying screw 91 to the dropping portion 96, where it is taken into the developer dropped from the upper conveying screw 86. Are mixed with each other, and the mixed developer enters the developing chamber through the developer discharge port, thereby increasing the toner concentration of the developer in the developing chamber.

Incidentally, the rear end wall 51 of the developing device unit 40.
Part, specifically, the development output gear 8 on the main body side, behind the revolver input gear 79 fixedly mounted on the rear end wall 51.
A developing input gear on the revolver developing unit side (not shown) that meshes with 1 is rotatably provided, and the developing roller 84 and the shafts of the upper and lower conveying screws 86 and 91 protruding through the rear end wall 51 and the like. Gears are fixed at the ends. With these, each rotating body (developing roller, etc.) is driven via the developing input gear and the like.

In the illustrated example, the developing roller 84Y is used as shown in FIG. 4 for the yellow developing device.
The front and rear end wall portions that support the doctor blade 85Y and the front and rear end wall portions are configured as small end wall portions 104 that can be separated from other front and rear end wall portions. Accordingly, when cleaning the inside of the developing chamber or replacing parts, the developing roller 84Y and the doctor blade 85Y together with the small end wall portion 104 can be removed to facilitate access to the developing chamber.

In FIG. 6, the toner container unit 45 has a disk-shaped unit face plate 108 (see also FIG. 3).
And a total of four toner receiving cases 109 mounted on the front surface of the face plate in a one-to-one correspondence with the developing devices.
Y, M, C, 110, and toner replenishing rollers 97Y, M, C, 97 as a developer supplying member provided in each toner receiving case are provided. This toner replenishing roller is provided with the lower carrying screw 9 into the case when the corresponding developing chamber is located at the developing position.
1 is pivotally supported by the front end wall portion of the case and the unit face plate 108 so as to be located almost directly above the extending portion.

The unit face plate 108 is shown in FIG.
A circular through hole 111 through which a cylindrical black toner container as shown in (b) can pass is formed in the central portion thereof,
The toner receiving cases 109Y, M, C, 110
Is mounted so as to escape the through hole 111. Further, the unit face plate 108 is also formed with a through hole for the lower carrying screw 91 extending from the developing chamber of each developing unit, and each lower carrying screw is provided with a through hole of each front carrying screw of the unit face plate 108. Case 10 for receiving each of the above toners
9Y, M, C, 110.

The unit face plate 108 bears the shafts of the toner replenishing rollers 97Y, M, C, and 97, and the end face of the shaft which penetrates the face plate 108 and projects toward the developing device unit 40 side. The gear 197 is fixed (FIG. 5).
reference). Then, as shown in FIG. 6, the unit face plate 1
A replenishment input gear 136 for driving input, which meshes with the gear 197, is rotatably provided on the surface of the developing unit 08 on the developing unit side. Of the replenishment input gears 136 provided for each of the toner replenishment rollers, the replenishment input gear 136 of the toner replenishment roller 97 corresponding to the developing device in the developing position, as shown in FIG. It is adapted to be meshed with a gear 62 driven by a replenishing motor 61 serving as a rotation driving means attached, and to be rotationally driven by the motor 61. The toner replenishment control is performed by the drive control of the replenishment motor 61.

The above four toner receiving cases 109
Of the Y, M, C, and 109, the three color toner receiving cases 109Y, M, and C corresponding to each color developing device are
All have the same shape. That is, when the case for receiving cyan toner is taken as an example, as shown in FIG. 8, a portion inside the case of the lower carrying screw 91 and the toner replenishing roller 97C are surrounded, and a corresponding developing chamber is located at the developing position. It sometimes has a peripheral wall portion having a toner receiving port formed at a position above the toner supply roller 97C. Around the toner receiving port, a color toner container 44 having the same shape for each color containing color toner is attached by sliding the revolver developing unit in the rotation axis direction with the toner discharge port facing downward. A mounting portion 113 is formed. As will be described later, the mounting portion 113 is configured so that the slide load does not become excessive and that sufficient toner scattering prevention performance can be exhibited when the slide is completed. A seal member 114C is provided on the inner wall surface of the case facing the toner replenishing roller 97C to seal the peripheral surface of the toner replenishing roller 97C.
Is attached. The seal and the toner supply roller 9
7C divides the inside of the toner container mounting portion 113 into the toner container side and the developing chamber side, and the seal and the case peripheral wall portion surrounding the toner replenishing roller 97C and the lower conveying screw 91C form a unit face plate. A communication chamber that communicates with the developing chamber of the corresponding developing device through the through hole, the dropping portion, or the like is defined. The toner replenishing roller 97Y,
As M, C, and 97, those having a roller portion in which a plurality of grooves extending in the axial direction are formed on the peripheral surface portion are used (see FIG. 8). (Hereinafter, margin)

Here, in the toner container unit 45 of this embodiment, as shown in FIG. 9, only one toner container (cyan toner container 44 at the position shown) is attached to and detached from the developing device 21. A toner container cover 301 having an opening portion 301a that enables the toner container cover 301 is attached and covered in the direction of arrow D in the drawing.

Further, in each toner container of this embodiment,
As shown in FIG. 10, the developing unit 40 in the rotation axis direction
On the toner container surface on the side, a filler 302 having a different radius r from the center of rotation is provided for each toner container. As a sensor capable of detecting the position of the filler 302 provided in each color toner container, for example, a reflection type detection sensor 3
03 is attached to a support member of the main body (not shown). Here, the detection sensor 303 used in the present embodiment is
A light emitting unit 303a and a light receiving unit 303 as shown in FIG. 11 so that the four fillers can be detected at one detection position.
In combination with b, four integrally formed sensors arranged in the radial direction of the rotating shaft are used.

In the above structure, the developing unit 40
The toner container unit 4 that rotates together with the developing device unit 40 by rotating the developing device unit by 90 ° to each developing device.
It is detected whether or not the toner container 5 is attached.
Here, as shown in FIG.
Means that the light emitted from each light emitting unit 303a is filled with the filler 30.
It is detected whether or not the light is reflected by 2 and received by the light receiving unit 303b. Based on this detection result, the determining means described later determines which color toner container is present at the detection position (removable position) and whether the toner container is not attached, and if it is not attached. If judged,
The rotation of the developing device unit is stopped by the control means described later. Further, since the order of the toner containers is predetermined, it is possible to specify the color that should be at the detection position from the color information detected immediately before, even if there is no toner container at the detection position, based on this determination result. It is possible to easily detect that there is no toner container of a specific color. However, if there is no toner container at the start of the first detection, "no cartridge of unknown color" is displayed.

FIG. 13 is a flow chart showing a detection processing procedure for detecting the presence / absence of a toner container in this embodiment. Here, a is a variable corresponding to the number of rotations in units of 90 °, b is a variable corresponding to the detection value obtained from the toner container detection sensor, c is a variable corresponding to the detection value stored in the buffer, and d is It is a variable corresponding to the color information determined to have no toner container.

When the presence / absence detection of the toner container is started, first, in step S101, the rotation speed of the developing device unit, that is, the variable a is reset to zero. Then, in step S102 and thereafter, the discriminating means discriminates the output from the detection sensor 303, and outputs the numerical value determined in advance for each color as the variable b based on the discrimination result. Then, when b = 0, the color of the toner container cannot be discriminated. Therefore, "there is no cartridge of unknown color" is displayed on the operation unit on the device panel of the display unit (not shown) (step S103), and the second The rotation of the developing device unit 40 is immediately stopped by the control signal of the control means.
If b ≠ 0, either toner container is present.
The processes of steps S104 to S107 are performed to determine the color of the toner container and hold it in the buffer (step S
108). Next, by the control signal of the first control means, the developing device unit 40 is rotated by 90 ° and the variable a is incremented by 1 (step S109), and it is determined whether or not b = 0 as in the above (step S110). ). Here, when b = 0, since there is no toner container, the rotation of the developing device unit 40 is immediately stopped by the control signal of the second control means as described above, and the previous color information, that is, the value of c. To identify the color that should be true (step S111). Then, in step S112, "there is no cartridge of color""(corresponding to d)" is displayed on the operation unit of the display unit (not shown). If b ≠ 0, it is determined in step S112 whether a = 3,
If a ≠ 3, the process returns to step S104, and detection is performed until the developing device unit 40 rotates 270 °.
Then, if a = 3, it means that all the toner containers are present, so that the series of detection processing ends.

According to the above embodiment, the rotation of the developing device unit 40 is stopped when the determination means determines that there is no toner container, so that the toner container rotates without being attached to the predetermined developing device 21. It is possible to prevent toner spilling that occurs when the toner is continuously kept. Further, with the rotation of the developing device unit 40, the toner spilled from the developing device 21 to which the toner container is not mounted can be prevented from scattering to the outside of the cover 301 by the toner container cover 301. Therefore, even if a small amount of toner spills from the developing device 21 due to rotation, deterioration of image quality caused when the spilled toner scatters on the transfer paper transported by the transfer paper transport belt 11, and the fixing device 12 When the toner is scattered in the vicinity, the toner is melted by heat, and it is possible to prevent the transfer paper from being clogged due to the increased friction between the melted toner and the transfer material conveyed to the fixing device 12. Further, unlike the case where a plurality of sensors are arranged on the outer circumference of the rotation of the toner container unit 45 to detect the presence or absence of the toner container, the number of sensors can be reduced, which leads to cost reduction and the sensor There is an advantage that the space for disposing is small. After the rotation of the developing device unit 40 is stopped, a predetermined amount of maintenance is performed by a service person or the like, and the toner container is attached.

FIG. 14 is a schematic explanatory view according to a modified example. In this example, the second detection sensor 30 as the second toner container detection means is located at a position where the detection sensor 303 of FIG. 10 and the rotation axis of the developing device unit 40 face each other.
4 are provided. The detection process will be described below.

FIG. 16 is a flowchart showing a detection processing procedure for detecting the presence / absence of a toner container according to the modification. Here, e is a variable corresponding to the output value of the detection sensor 303, g is a variable corresponding to the output value of the second detection sensor 304, f and h are variables corresponding to the sensor output value stored in each buffer, i and j are variables corresponding to the colors determined to have no toner container.

The presence / absence of the toner container is first judged based on the output result of the detection sensor 303. Step S
When the detection result of 201 is e = 0, the color of the toner container cannot be discriminated. Therefore, "there is no cartridge of unknown color" is displayed on the operation unit on the device panel of the display unit (not shown) (step S202). The rotation of the developing device unit 40 is immediately stopped by the control signal of the second control means. When e ≠ 0, step S
In steps S203 to S206, which toner container is at the detection position is determined based on the variable output from the detection sensor 303, and the numerical value corresponding to the color of the toner container at the detection position is determined. Is stored in the variable f of the buffer (step S207). If e ≠ 0, one of the toner containers is in the detection position, and therefore, in steps S208 to S213, the second detection sensor 304 is detected.
The presence / absence of the toner container and which toner container is at the detection position are determined based on the variable output from the determination unit that determines the output from the.

When the detection result is g = 0 in step S208, the color of the toner container cannot be discriminated, so that "there is no cartridge of unknown color" is displayed on the operation unit on the device panel of the display means (not shown). At the same time (step S209), the rotation of the developing device unit 40 is immediately stopped by the control signal of the second control means.
When g ≠ 0, steps S210 to S213
Then, it is determined which toner container is at the detection position based on the variable output from the determination unit that determines the output from the detection sensor 304, and the numerical value corresponding to the color of the toner container at the detection position is calculated. It is stored in the variable h of the buffer (step S214).

Next, by the control signal of the first control means,
Rotate the developing unit 40 by 90 ° (step S2
15). Then, it is again determined whether or not the output from the determination means for determining the output of the detection sensor 303 is e = 0 (step S216). Here, when e = 0, since there is no toner container, the rotation of the developing device unit 40 is immediately stopped by the control signal of the second control means as described above, and the previous color information, that is, the value of f To identify the color that should be present (step S217). Then, in step S218, "there is no cartridge of color" (corresponding to i) "is displayed on the operation unit of the display means (not shown). If e ≠ 0, then it is determined whether or not the output from the determination means for determining the output of the detection sensor 304 is g = 0 (step S219). Where g = 0
In this case, since there is no toner container, the rotation of the developing device unit 40 is immediately stopped by the control signal of the second control means as described above, and the original color information, that is, the value of f is referred to. Specify the color to be used (step S2)
20). Then, in step S218, "there is no cartridge of color""(corresponding to j)" is displayed on the operation unit of the display unit (not shown). If g ≠ 0, it means that all the toner containers are mounted, and the series of detection processes is completed.

According to the above modification, the detection sensor 303 and the second detection sensor 304 provided at a position where the sensor 303 and the rotation axis of the developing device unit 40 face each other.
Since it is checked whether or not the toner container is attached to the developing device 21 by using the two sensors of the above, it is possible to check whether or not the toner container is attached to each toner container by only one sensor. There is an advantage that it can be completed in a short time.

Here, when the toner containers for all the colors are mounted, if the development is started from the position of the developing device 21 after the detection is completed, the developing colors on the photosensitive drum 1 are developed. At the time of starting the agent, it will always start from a different developing device 21. Normally, even a printer for a full-color application often outputs only black as the actual frequency of use. Therefore, if there is a developing device other than the black developing device at the developing position, it is necessary to move the black developing device to the developing position, and it takes a long time to form an image on the first sheet, resulting in a time loss. Is big. Also,
If development is started from the position of the developing device after detection is completed, the order of overlapping colors will change each time, so the image forming conditions will not be constant, the hue will change, and the image quality will become unstable. There are cases.

Therefore, it is desirable to add a process for moving the black developing device 21K to the developing position after the process described with reference to FIG. 14 or FIG. FIG. 17 is a flowchart showing an example thereof. Here, k is a variable corresponding to the color detected by the sensor 303. In this example, the black toner container 41 is rotated 90 ° upstream from the developing position at k = 1, and at k = 2. Development position,
When k = 3, it is rotated 90 ° downstream of the developing position, and when k = 4, it is rotated 180 ° with respect to the developing position.

After the processing shown in FIG. 14 or 16 is completed, the value of k is determined in the processing of steps S301, S303 and S304. If k = 1 in step S301, in step S302 the developing unit 4
Rotate 0 by 90 °. In step S302, k =
If it is 2, the process is terminated. If k = 3 in step S304, in step S305 the developing unit 4
Rotate 0 to 270 °. K in step S304
If ≠ 3, the developing device unit 40 is rotated 180 ° in step S306.

In this way, the rotation angle of the developing device unit 40 is adjusted according to the value of k so that the developing device 21K of the same color, that is, the black developing device 21K in the present modification is always at the predetermined developing position.

According to the above modification, by moving the black developing device 21K to the developing position after the detection process is completed, the first image to be formed after the detection process is black only. In this case, the first image can be obtained without spending time, and the condition of the color fragrance can be made uniform, so that an image of stable quality can be obtained.

Here, in the example shown in FIGS. 10 and 12, the filler 302 is provided at a different position for each toner container, but this makes the toner container common.
It is not preferable in terms of cost reduction such as mold cost. Therefore, as shown in FIG. 15, the filler 302 is attached only to the black toner container 41. A toner container detection sensor 305 that detects only the presence or absence of the toner container, and a filler detection sensor 306 that detects the presence or absence of the filler 302 (black toner container in this example) provided in the specific toner container. The presence or absence of the toner container and the color of the toner container based on the position of the black toner container 41 can be determined based on the detection results. it can.

FIG. 18 is a flow chart showing an example thereof. Here, s is 90 for the toner container unit 45.
A variable corresponding to the number of rotations in degrees, t is a variable corresponding to the detection value of the toner container detection sensor 305, and u is a filler detection for detecting a specific developing device (black developing device in this embodiment). A variable corresponding to the detection value of the sensor 306, v is a variable corresponding to the output value of the determination unit when the determination unit determines that there is no toner container.

When the presence / absence detection of the toner container is started, first, in step S401, the rotation speed of the developing device unit, that is, the variable s is reset to zero. Then, in step S402, the determination means determines the presence or absence of the toner container based on the output from the toner container detection sensor 305, and based on the result of the determination, a numerical value previously determined for each color is set as a variable t. Output. Where t =
If 0, that is, if the toner container is not installed, the color of the toner container cannot be identified, so that "there is no cartridge of unknown color" is displayed on the operation unit on the device panel of the display unit (not shown) (step S103). At the same time, the rotation of the developing device unit 40 is immediately stopped by the control signal of the second control means. Then, a numerical value determined in advance for each color based on the discrimination result is output as a variable t. If t ≠ 0, there is any toner container, and it is determined based on the output from the filler detection sensor 306 whether or not there is a filler in the toner container at the detection position (step S404). ). If u = 1, proceed to the next step. If u ≠ 1, the developing unit 4 is operated based on the control signal of the first control means.
0 is rotated by 90 ° (step S405), and the developing device unit 40 is rotated by 90 ° until the filler is detected for detection. When the toner container with the filler, that is, the black toner container 41 is detected,
Next, in step S406, the developing device unit 40 is rotated by 90 ° by the control signal of the first control means, the variable s is incremented by one, and the detection sensor 305 refers to the position of the black toner container 41 to store the toner. The presence or absence of a container is detected. Then, in step S407, t =
0, that is, if there is no toner container, the color of the toner container that is not mounted is specified by referring to the position of the black toner container 41 (step S408), and "" (v (There is no color toner container) (step S409). Then, the rotation of the developing device unit 40 is immediately stopped by the second control means. When t ≠ 0, that is, when the toner container is attached, it is determined in step S410 whether s = 4, that is, whether the developing device unit 40 has rotated once. If s ≠ 4, the process returns to step S406, and if s = 4, it is determined that all the toner containers are mounted, and the series of processes is ended.

According to the above modification, the developing unit 40
The toner spill can be prevented to some extent by detecting the presence or absence of the toner container in the toner container detection sensor 305 before the rotation of the toner container and before the detection of the filler detection sensor 306. Therefore, the toner container can be shared. It is suitable for an apparatus that needs to reduce costs such as mold cost as much as possible.

[0064]

According to the first aspect of the present invention, the rotation of the developing device unit is stopped at the time when the determining means determines that the removable toner container is not present. There is an excellent effect that it is possible to prevent toner spillage that occurs when the toner is continuously rotated without being attached to the container. Further, as compared with a case where a plurality of detecting means are arranged on the outer circumference of rotation of the toner container and the presence or absence of the toner container is detected, the number of the detecting means can be reduced, which leads to cost reduction, There is an advantage that the space for disposing the detecting means can be small.

According to the second aspect of the invention, at the time when the determination means determines that the removable toner container is not present,
Since the rotation of the developing device unit is stopped, there is an excellent effect that it is possible to prevent toner spilling that occurs when the removable toner container is continuously rotated without being attached to a predetermined developing device. Further, since the detection is performed without rotating the developing device unit as much as possible, toner spillage is less likely to occur and the time required to detect the presence / absence of the removable toner container can be shortened.

Particularly, according to the third aspect of the invention, since the developing device unit is rotated by the control means so that the specific developing device is always in the developing position, for example, the development of the frequently used color is performed. By setting the container at a predetermined position, the time required for forming the first image can be shortened. Also, compared to the case where development is performed from the color of the developing device at the developing position after detection, the image forming conditions are always constant, so there is no change in hue and stable quality images are obtained. You can

In particular, according to the invention of claim 4, since the specific toner container can be discriminated by the discriminating portion provided in the toner container, it is possible to distinguish the developing device from the developing device equipped with the toner container having the discriminating portion. It is possible to easily set a specific developing device at a specific position based on the positional relationship.

In particular, according to the invention of claim 5, since the display means displays that the determination means determines that the toner container is not present, the operator can easily recognize the fact. You can

In particular, according to the invention of claim 6, the toner, which may possibly be spilled from the developing device to which the removable toner container is not attached, by the toner container cover member due to the rotation, is covered by the cover member. Therefore, even if toner spills from the developing device due to rotation, if the spilled toner is scattered on the transfer material that is transported inside the image forming apparatus main body. When the image quality is deteriorated or the toner is scattered near the fixing portion, the toner is melted by heat, and the transfer material clogged due to the increased friction between the melted toner and the transfer material conveyed to the fixing portion. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view illustrating a schematic configuration of an electrophotographic printer according to an embodiment.

FIG. 2 is a schematic configuration diagram showing a main part of the printer.

FIG. 3 is an exploded perspective view of the developing device.

FIG. 4 is a sectional view showing an internal structure of a developing unit of the developing device.

FIG. 5 is a vertical cross-sectional view of a plane including the central axis of the upper and lower conveying screws of the black developing device.

FIG. 6 is a sectional view showing the internal structure of the toner container unit.

FIG. 7A is a front view of a black toner container. (B) is a top view of the container.

FIG. 8 is a perspective view of a color toner container and a container mounting portion.

FIG. 9 is an explanatory view showing a mounting direction of the toner container cover with respect to the toner container unit.

FIG. 10 is a front view of the toner container unit according to the present embodiment.

FIG. 11 is an explanatory diagram showing a position of a filler provided in the toner container unit.

FIG. 12 is a perspective view of a detection sensor used in this embodiment.

FIG. 13 is a flowchart showing a detection processing procedure for detecting the presence / absence of a toner container according to the present embodiment.

FIG. 14 is an explanatory diagram showing an arrangement of detection sensors according to a modification.

FIG. 15 is an explanatory diagram showing an arrangement of detection sensors according to another modification.

FIG. 16 is a flowchart showing a detection processing procedure for detecting the presence / absence of a toner container according to a modification.

FIG. 17 is a flowchart showing a processing procedure of rotating the developing device unit so that a specific toner container is located at a predetermined position after detecting the presence or absence of the toner container.

FIG. 18 is a flowchart showing a detection processing procedure for detecting the presence / absence of a toner container according to another modification.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 4 Rotational developing device 5 Intermediate transfer belt 21 Developing device 22 Developing sleeve 40 Developing device unit 41 Black toner container 42 Yellow toner container 43 Magenta toner container 44 Cyan toner container 45 Toner container unit 301 Toner Container cover 301a Opening 302 Filler 303 Detection sensor 303a Light emitting part 303b Light receiving part 304 Second detection sensor 305 Toner container detection sensor 306 Filler detection sensor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03G 21/00 386 G03G 21/00 386

Claims (6)

[Claims] 1. A developing device unit having a plurality of developing devices arranged around a rotation center line is rotated about the rotation center line to bring an arbitrary developing device to a development position facing a latent image carrier. A rotary developing device that sets and develops the latent image on the latent image carrier, and is attachable to and detachable from each of the developing devices.
Further, in an image forming apparatus having a detachable toner container configured to be rotatable together with the developing device unit, it is possible to detect the presence or absence of the detachable toner container at a predetermined position which is sequentially reached as the developing device unit rotates. Toner container detecting means provided, first control means for rotating the developing device unit before the developing operation, and detection of the toner container while the first controlling means makes one rotation of the developing device unit. Based on the detection result detected by the means, a determination unit that determines the presence or absence of the removable toner container, and a determination unit that determines that the removable toner container does not exist An image forming apparatus provided with a second control means for controlling to stop rotation. 2. A developing device unit having a plurality of developing devices arranged around a rotation center line is rotated about the rotation center line to bring an arbitrary developing device to a developing position facing a latent image carrier. A rotary developing device that sets and develops the latent image on the latent image carrier, and is attachable to and detachable from each of the developing devices.
Further, in an image forming apparatus having a detachable toner container configured to be rotatable together with the developing device unit, it is possible to detect the presence or absence of the detachable toner container at a predetermined position which is sequentially reached as the developing device unit rotates. First toner container detecting means provided, second toner container detecting means provided at a predetermined position other than the position where the first toner container detecting means is provided, and the developing device before the developing operation. Control means for rotating the container unit in a predetermined rotation direction by a predetermined angle, and detection by the first toner container detector and the second toner container detector while the controller rotates the developer unit. Based on the detected result, a determination unit that determines the presence or absence of the removable toner container, and the determination unit determines the current state when the determination unit determines that there is no removable toner container. An image forming apparatus characterized by providing a second control means for controlling to stop rotation of the vessel unit. 3. The image forming apparatus according to claim 1, wherein after the completion of detection by the toner container detecting means, the determining means determines that all the toner containers are set in their respective developing devices. In this case, the image forming apparatus is provided with control means for controlling the rotation of the developing device so as to rotate the specific developing device to the developing position. 4. The image forming apparatus according to claim 1, wherein at least one of the toner storage containers is provided with a determination unit for determining that the toner storage container is a predetermined toner storage container. An image forming apparatus, characterized in that a discriminating unit capable of specifying a developing device corresponding to a toner container having a section is provided. 5. The image forming apparatus according to claim 1 or 2, further comprising display means for displaying a message to the effect that the determination means determines that the toner container is not present. apparatus. 6. The image forming apparatus according to claim 1, further comprising a toner container cover member that covers the removable toner container so as to have an opening to which only one container can be attached and detached. An image forming apparatus, wherein the position of the toner container detecting means of claim 1 or the position of the first toner container detecting means of claim 2 is set in the vicinity of the opening of the toner container cover member.