JP2000250298A - Toner replenishing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner replenishing device by which toner is replenished with great certainty when a stirring means is redriven and which is made small- sized and is inexpensive and to obtain an image forming device provided with the toner replenishing device. SOLUTION: The stop position of an agitator 18 is controlled by a control circuit so as to satisfy the relation of 0 deg.<=θc<=135 deg.. when an angle measured from right under the center of rotation of an agitator 18 to the position of a cleaning member 32 in a rotating direction is defined as θc. The toner flocculated around the cleaning member 32 is scraped up to the upper part of a main body 16 in a state that the flocculation of the toner is comparatively loose by the cleaning member 32 when the agitator 18 is redriven, and the toner scraped up is moved to the space S of the upper part at the inside of the main body 16 so that the agitator 18 is easily redriven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner replenishing device and an image forming apparatus, and more particularly, to a toner replenishing device for replenishing toner to a developing device used in an image forming device such as a copying machine, a facsimile, a printer, and the like. The present invention relates to an image forming apparatus provided with the toner supply device.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine or a laser printer for forming a toner image on a photosensitive drum by an electrophotographic method, a developing device is provided in a developing area of the photosensitive drum. The toner is attached to the electrostatic latent image formed on the photosensitive drum to obtain a toner image. This toner image is transferred to a sheet and further fixed to obtain a desired image on the sheet.

Further, since toner is gradually consumed by the formation of an image, the image forming apparatus is provided with a toner replenishing device for replenishing the developing device with toner. In particular, since a relatively medium to high speed image forming apparatus consumes a large amount of toner per unit time, a large-capacity toner container is provided separately from the developing device, and a toner transport device is used from this toner container. The toner is supplied to the developing device as needed.

FIG. 9 shows an example of such a toner replenishing device (see Japanese Patent Application Laid-Open No. 1-199379).

In the toner supply device 110, a spiral auger 114 is provided at the bottom of the toner container main body 112, and the toner is conveyed to the main developing device by the rotation of the auger 114. Further, a coil-shaped agitator 116 is rotatably provided in the storage section of the toner storage container main body 112, and the rotation of the agitator 116 does not cause the toner to become partially dense or sparse. Thus, the toner is uniformly stirred, and the aggregation of the toner is prevented.

In the toner supply device 110, a toner sensor 120 is provided on a side wall 118 of the main body of the toner supply device 110. Since the remaining amount of toner is detected by the toner sensor 120, it is possible to supply a sufficient amount of toner to the developing device to perform efficient image formation, and to always obtain a good image having an appropriate density. ing. Further, in the toner supply device 110, a cleaning member 122 for removing toner attached to the toner sensor 120 is attached to the agitator 116. The rotation of the agitator 116 causes the cleaning member 122 to remove the toner attached to the toner sensor 120, thereby preventing erroneous detection.

By the way, if the image forming apparatus provided with the toner supply device 110 as described above is not used for a long time or left in an environment of high temperature and high humidity, for example, May harden. Further, the toner may be hardened by the minute vibration during the operation of the image forming apparatus.
However, in such a toner supply device 110, when the rotation of the agitator 116 is stopped, the rotation position of the agitator 116 is not particularly set and is set to an arbitrary position. May stop relatively high. Toner container main body 1
When the remaining amount of toner in the toner container 12 is large,
Since the upper part of the toner 12 is relatively sparse in toner, the cleaning member 122 has to move from the area where the toner is sparse to the area where the toner is gradually sparse. A large driving force is required to drive the agitator 116, which may lead to an increase in size and cost of the toner supply device 110. Further, it is necessary to improve the strength of the cleaning member 122 and the agitator 116 so that the rotation of the agitator 116 does not damage the cleaning member 122 and the agitator 116, which may also increase the weight and cost.

In order to solve such a problem caused by the aggregation of toner, a toner supply device 130 shown in FIG. 10 has been proposed (see Japanese Patent Application Laid-Open No. 7-306595). In the toner supply device 130, a plurality of agitating members 132 are provided radially around the rotation shaft 134, and the agitator 136 is controlled so that the agitator 136 stops in a state where at least one agitating member enters the toner retaining portion. At the time of re-drive of 136, the agitating member 132 in the toner retaining portion is made to scrape up the toner, so that the agitating operation can be reliably performed.

However, in this toner supply device 130,
For example, when the amount of toner in the toner box 138 is large, the plurality of agitating members 132 (or all the agitating members 132) may be located in the toner. If the toner aggregates in such a state, the resistance of the agitator 136 at the time of re-driving increases.

[0010]

SUMMARY OF THE INVENTION In consideration of the above fact, the present invention provides a small and low-cost toner replenishing apparatus capable of reliably replenishing toner when the stirring means is re-driven. It is an object to obtain an image forming apparatus provided with a toner supply device.

[0011]

According to the first aspect of the present invention, a toner accommodating member for accommodating toner, a stirring means for agitating the toner accommodated in the toner accommodating member, and a toner accommodating member accommodated in the toner accommodating member are provided. Remaining amount detecting means for detecting the remaining amount of toner, a removing member provided in the stirring means, and removing the toner attached to the detection surface of the remaining amount detecting means by driving the stirring means; and driving the stirring means. And control means for stopping the stirring means so that the removing member is located at the bottom of the toner accommodating member when stopped.

Therefore, by driving the stirring means,
The toner accommodated in the toner accommodating member is uniformly stirred so as not to become partially dense or sparse, and aggregation of the toner is prevented.

Further, since the removing member removes the toner adhered to the detection surface of the remaining amount detecting means by driving the stirring means, the remaining amount detecting means can always detect the remaining amount accurately.

The stirring means is controlled by the control means, and stops when the drive is stopped so that the removing member is located at the bottom of the toner accommodating member. For this reason, when the stirring means is driven again, the removing member moves while scraping up the toner to a region in the toner containing member where the toner is relatively sparse. Since a predetermined space is generally formed in the upper part of the toner containing member, the scraped-up toner retreats to this space. For this reason, the stirring means can be reliably driven with a small driving force.

[0015] Further, the toner is scraped up near the bottom in the toner accommodating member, so that the density of the toner becomes relatively low. Therefore, when the cleaning member moves toward the vicinity of the bottom of the toner containing member, the resistance of the movement is reduced, so that the stirring means can be driven with a small driving force.

As described above, since the driving resistance at the time of re-driving the stirring means is reduced, the toner can be reliably supplied at low cost, and the toner replenishing device can be downsized.

The term "bottom" in the present invention is used to reduce the driving force when the stirring means is re-driven.
A portion where the removing member moves to a region where the density of the toner gradually decreases. Accordingly, it includes the vicinity of the lowermost portion in the toner containing member and the region at least from the vicinity thereof in the moving direction of the stirring means.

According to a second aspect of the present invention, in the first aspect of the present invention, the toner attached to the removing member moves in the toner accommodated in the toner accommodating member by the driving of the stirring means. It has a moving member that forms an area with low density.

When this moving member is driven again by the stirring means,
Since the toner moves in the toner contained in the toner containing member to form a region where the toner density is low, the toner pressed by the stirring means moves to the low density region. Thereby, the driving force required for driving the stirring means can be further reduced.

According to a third aspect of the present invention, in the first or second aspect of the invention, the agitator is disposed in the toner accommodating member and agitates the toner by rotation. A rotation drive unit for rotating the agitator, wherein the control unit detects the rotation position of the agitator and the rotation drive based on the rotation position of the agitator detected by the rotation position detection unit. And a control circuit for controlling the means.

Therefore, the control circuit controls the rotation driving means to rotate the agitator until the rotation position of the agitator detected by the rotation position detection means reaches a desired position.

As described above, the stirring means can be constituted by the agitator and the rotation driving means, and the control means can be constituted by the rotation position detecting means and the control circuit, so that the structure of the toner replenishing device can be simplified. Become.

According to a fourth aspect of the present invention, a photosensitive member on which an electrostatic latent image corresponding to image information is formed, and a developing device for forming a toner image by attaching toner to the electrostatic latent image on the photosensitive member The toner supply according to any one of claims 1 to 3, wherein an apparatus, a transfer device that transfers a toner image formed on the photosensitive member by the developing device to an image forming medium, and toner is supplied to the developing device. And a device.

Toner is adhered to the electrostatic latent image on the photosensitive member by a developing device to form a toner image. And
The transfer device transfers the toner image to the image forming medium, and a desired image is obtained on the image forming medium.

The replenishment of the toner to the developing device is described in claim 1
The toner supply is performed by the toner supply device according to claim 3. Accordingly, even when the toner is aggregated, such as when the image forming apparatus has been stopped for a long time, or when the image forming apparatus has been left in a high-temperature, high-humidity environment, the aggregated state is released, and the toner is released to the developing device. The toner can be reliably supplied.
Further, since the toner supply device can be driven at low cost, the image forming apparatus can also be operated at low cost. Further, by reducing the size of the toner supply device, the size of the image forming apparatus can be reduced.

[0026]

FIG. 1 shows a toner supply device 10 according to an embodiment of the present invention, a developing device 12 to which toner is supplied by the toner supply device 10, and a developing device 1.
2 shows a photosensitive drum 14 on which a toner image is formed by supplying toner. FIG. 8 shows a schematic configuration of an image forming apparatus 46 further including an optical scanning device 50, a transfer device 44, and a fixing device 60 in addition to the above components.

As shown in FIG. 1, the toner supply device 10
Has a main body 16 in which the toner is stored. Body 1
As shown in FIG. 2, reference numeral 6 denotes a box shape having an upper portion formed in a square cylindrical shape and a lower portion formed in an arc-shaped cross section. Functioning as

The main body 16 is provided with an agitator 18 as a stirring means for stirring the contained toner at a predetermined timing to prevent the toner from blocking (a phenomenon in which the toner hardens). The both ends of the agitator 18 are formed as mounting portions 18A rotatably mounted on the side walls 20 and 22 of the main body 16. A linear portion 18B extends radially outward from the attachment portion 18A, and further includes a spiral portion 18 between the linear portions 18B.
C is provided along the width direction of the main body 16 (the left-right direction in FIG. 1). One of the mounting portions 18A extends outside through the side wall 20, and a gear 24 is fixed to the extending portion. When the gear 24 is rotated by the motor 42, the agitator 18 is rotationally driven.

As shown in FIG. 2, a guide 16A having a substantially U-shaped cross section is provided at the bottom of the main body 16. An auger 26 for conveying the toner is rotatably provided inside the guide 16A. This auger 26 is also a motor 4
2 is transmitted via the gear 43 to rotate. The toner conveyed by the auger 26 is supplied into the developing device 12 through a supply port 28 formed on the bottom surface of the guide 16A.

At a position below the side wall 20 of the main body 16 as shown in FIG. Is provided. The toner sensor 30 is formed in a flat and substantially columnar shape, and has one bottom surface serving as a detection surface 30A.
A is flush with the inner surface of the side wall 20 of the main body 16,
It is attached to the side wall 20. And the detection surface 30A
Utilizing the fact that the vibration state of the voltage element differs depending on whether or not the toner is in contact with the main body 16, it is detected whether or not the toner in the main body 16 is equal to or more than a certain amount.

As shown in detail in FIGS. 3 and 4, a comb-shaped cleaning member 32 is attached to the linear portion 18B of the agitator 18. The cleaning member 32 includes a film 34 made of polyethylene terephthalate or the like, and a base end 34A of the film 34 is attached to a linear portion 18B of the agitator 18 via a reinforcing plate 36 having a substantially L-shaped cross section. ing. A support portion 36A having a predetermined length is formed on the reinforcing plate 36 along a flexible side 34B of the film 34, and the film 34 is lined with the support portion 36A. And this cleaning member 32
When the film 34 passes through the detection surface 30A of the toner sensor 30, the leading end side of the film 34 is in sliding contact with the detection surface 30A while being deformed, and removes the toner attached to the detection surface 30A and cleans it.

As shown in FIGS. 3 and 5, the agitator 1
A pin 38 is provided on the outer end surface of the gear 24 fixed to the mounting portion 8 in the same direction as the axial direction of the gear 24. Corresponding to this pin 38, the main body 16 has a pin 3
The switch member 40, which is turned on and off, is mounted via a mounting member (not shown). Since the phase relationship (rotational position) between the pin 38 and the cleaning member 32 is fixed, when the switch member 40 is turned on and off by the pin 38, the position of the cleaning member 32 can be detected as a result. . Although the specific configuration of the switch member 40 is not particularly limited, for example, by using a microswitch or a photosensor, both miniaturization and high reliability can be achieved.

The toner replenishing device 1 having such a configuration
0 supplies toner to the developing device 12 as shown in FIG. The developing device 12 forms a toner image on the photosensitive drum 14 by attaching toner to the photosensitive drum 14 on which an electrostatic latent image corresponding to image information is formed. Further, the paper 54 is brought into contact with the photosensitive drum 14 by the transfer device 44 to transfer the toner image onto the paper 54, and is fixed by the fixing device 60.

As shown in FIG. 7, the toner sensor 30, the switch member 40, the motor 42, and the developing device 12 are connected to a control circuit 48, respectively. The control circuit 48 includes the toner sensor 30 and the switch member 40
The motor 42 and the developing device 12 are controlled on the basis of the signal from.

Next, the toner replenishing device 10 of the present embodiment
The operation of the image forming apparatus 46 will be described.

As shown in FIG. 8, in the image forming apparatus 46, light is scanned by an optical scanning device 50, and this light is incident on the photosensitive drum 14, and an electrostatic latent image is formed on the surface of the photosensitive drum 14. It is formed. Next, the developing device 12 causes toner to adhere to the electrostatic latent image formed on the photosensitive drum 14, and a toner image is formed on the photosensitive drum 14. Accordingly, the toner in the developing device 12 is sequentially consumed. The toner image is transferred to the sheet 5 conveyed from the sheet tray 56.
4 is fixed by the transfer device 54. Further, the image on the paper 54 is fixed by the fixing device 60 and is discharged to the discharge tray 58.

A predetermined amount of toner is stored in the main body 16 of the toner supply device 10 in advance. Since the amount of toner consumed by the developing device 12 is predicted depending on various conditions such as the amount of the image and the density of the image,
Based on the predicted amount, the control circuit 48 drives the motor 42 for a predetermined time, rotates the auger 26, and replenishes the developing device 12 with an amount of toner corresponding to the reduced amount. As a result, a necessary and sufficient amount of toner is always secured in the developing device 12. Further, since the agitator 18 also rotates with the driving of the motor 42, the toner in the main body 16 is agitated, and the so-called blocking phenomenon is prevented.

The control circuit 48 detects whether or not the switch member 40 has been turned on by the pin 38 when the motor 42 has been driven for a predetermined time, that is, when the rotation of the agitator 18 is stopped. When the switch member 40 is in the off state, the motor 42 is driven to rotate the agitator 18 until the switch member 40 is turned on. Thus, the agitator 18 is controlled such that the cleaning member 32 is always at a predetermined rotational position in the main body 16 when the rotation is stopped. This predetermined rotational position is defined as the agitator 1
At the time of re-driving, the position is set such that the driving resistance is minimized.

FIG. 6 shows the relationship between the position (stop position) of the cleaning member 32 and the driving torque when the agitator 18 is driven again for each degree of toner aggregation. As shown in FIG. 2, the “position of the cleaning member” on the horizontal axis of the graph indicates the position of the cleaning member 3 just below the rotation center of the agitator 18.
It means the angle θ _C measured in the direction of rotation up to the position 2. Further, “light aggregation” refers to a state in which the toner filled in the toner containing member (main body 16) is left for about one month, and the air between the toner particles is reduced and the gap between the toner particles is clogged. "Medium aggregation" means that the toner filled in the toner storage member (main body 16) is left for about three months, and the toner particles are slightly fused with each other. And the state in which the toner filled in the toner accommodating member (main body 16) is left for 6 months or more, the fusion of toner particles is strengthened, and the weight is increased by further containing water. As can be seen from this graph, when the agitator 18 is driven again, the stop range of the cleaning member 32 at which the driving resistance is minimized is set to a range satisfying 0 ° ≦ θ _C ≦ 135 °. Is preferred. That is, if the angle is larger than 135 °, as the agitator 18 moves, the agitator 18 proceeds to a region where the starting torque is further increased. As a result, a large starting torque is required.

On the other hand, when the agitator 18 is set in the above-described range, the toner agglomerated around the cleaning member 32 when the agitator 18 is driven again causes the toner to be relatively agglomerated by the moving cleaning member 32. The sparse body is lifted up by the upper part of the main body 16. A fixed space S (see FIGS. 1 and 2) is usually secured in the upper part of the main body 16, and this space S acts as a so-called escape space for the toner scraped up by the cleaning member 32. For this reason, even if the cleaning member 32 is located at the lower part of the main body 16 where the aggregation of the toner is relatively dense, the agitator 18 can be easily driven again.

Further, the cleaning member 32, which continues the rotation of the re-driven agitator 18 and moves to the upper side of the main body 16 in which the aggregation of the toner is relatively sparse, is then moved to the lower side of the main body 16. Move toward the side. At the first rotation after the agitator 18 is re-driven, the lower portion of the main body 16 has a relatively dense state of toner aggregation, and the lower portion of the main body 16 is formed in an arc-shaped cross section. Cleaning member 32
As a result, there is no place for the pushed toner, and the rotation of the agitator 18 becomes difficult. That is, in order to continue the rotation of the re-driven agitator 18, the cleaning member 3 is required.
When the toner cartridge 2 moves toward the lower side of the main body 16, it is necessary to secure a destination of the toner to be pushed by the cleaning member 32. For this purpose, the range in which the cleaning member 32 is stopped is preferably in the vicinity of the lower side of the main body 16 (for example, 0 ° ≦ θ _C ≦ 45 °).

After the agitator 18 is driven again,
To further continue the rotation, a spacer 52 having a cross section substantially similar to that of the reinforcing plate 36 may be attached to the back surface of the reinforcing plate 36 as shown in FIGS. 2 and 4A.

That is, when the agitator 18 is driven again,
The toner agglomerated in the vicinity of the cleaning member 32 is swept up by the moving cleaning member 32 to the upper side of the main body 16 in which the aggregation of the toner is relatively sparse.
On the back side of the cleaning member 32, a cavity after the spacer 52 has passed or a region where toner aggregation is relatively low is formed. Therefore, when the cleaning member 32 moves toward the lower side of the main body 16 as the rotation of the agitator 18 continues, the toner pushed into the cleaning member 32 moves to the above-mentioned cavity or the region where the toner aggregation is relatively sparse. Moving. Therefore, the rotation of the agitator 18 can be easily continued.

Since the spacer 52 is attached to the back of the cleaning member 32, that is, on the side opposite to the rotation direction of the agitator 18, the spacer 52 does not hinder the agitator 18 from stirring. Further, since the cross-sectional shape of the spacer 52 is substantially the same as the cross-sectional shape of the reinforcing plate 36, there is no resistance to rotation of the agitator 18.

The shape of the spacer 52 is shown in FIG.
When the cleaning member 32 is stopped at a predetermined position as shown in FIG.
It is preferable that the shape does not overlap with A.

As described above, in the toner replenishing apparatus 10 of the present embodiment, the driving force required at the time of re-driving is reduced by setting the position of the cleaning member 32 when the agitator 18 stops at a predetermined position. be able to. Further, even in the first rotation of the agitator 18 after the re-drive, the rotation of the agitator 18 can be reliably continued with a small driving force, and the toner in the main body 16 can be stirred.
In particular, even when the toner in the main body 16 is agglomerated, such as when the toner has been left for a long time, the toner can be reliably stirred and supplied to the developing device 12. Further, the toner can be supplied at low cost, and the size of the toner supply device 10 can be reduced.

Also, in the image forming apparatus 46 having the toner replenishing device 10, the necessary and sufficient toner can be surely replenished, so that a high-quality image can always be formed. The overall size can be reduced. Although FIG. 8 shows the image forming apparatus 46 in which the toner supply device 10 is provided inside the housing of the image forming device 46, the toner supply device 10
May be provided outside the housing of the image forming apparatus 46. Particularly, for example, in a medium-speed image forming apparatus, the amount of toner consumption per unit time is large.
It is preferable from the viewpoint of stably replenishing toner that the size is increased by providing the outside of the housing of the image forming apparatus 46 and a large amount of toner is stored.

[0048]

According to the present invention, a toner accommodating member for accommodating toner, an agitating means for agitating the toner accommodated in the toner accommodating member, and a residual for detecting the remaining amount of toner accommodated in the toner accommodating member are provided. An amount detecting unit, a removing member provided in the stirring unit, and removing the toner attached to the detection surface of the remaining amount detecting unit by driving the stirring unit, and the removing member is configured to store the toner when the driving of the stirring unit is stopped. And control means for stopping the stirring means so as to be located at the bottom of the member, so that when the stirring means is re-driven, toner replenishment can be reliably performed at low cost, and the toner replenishing device is provided. Becomes smaller.

[Brief description of the drawings]

FIG. 1 illustrates a toner supply device according to an embodiment of the present invention;
FIG. 2 is a schematic configuration diagram illustrating a developing device and a photosensitive drum to which toner is supplied by the toner supply device.

FIG. 2 is a longitudinal sectional view showing the toner supply device according to the embodiment of the present invention.

FIG. 3 is a partially cutaway front view showing the vicinity of one end of an agitator and a gear portion used in the toner supply device according to the embodiment of the present invention;

FIGS. 4A and 4B are a side view and a front view, respectively, showing the vicinity of one end of an agitator and a gear used in the toner supply device according to the embodiment of the present invention.

5A and 5B show a gear used in the toner supply device according to the embodiment of the present invention, wherein FIG. 5A is a front view and FIG. 5B is a side view.

FIG. 6 is a graph showing a relationship between a position of a cleaning member and a starting torque of an agitator in the toner supply device according to the embodiment of the present invention.

FIG. 7 is a block diagram of a toner supply device according to the embodiment of the present invention.

FIG. 8 is a schematic configuration diagram illustrating an image forming apparatus using the toner supply device according to the embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a conventional toner supply device.

FIG. 10 is a perspective view showing a conventional toner supply device.

[Explanation of symbols]

 Reference Signs List 10 toner replenishing device 12 developing device 14 photoreceptor drum (photosensitive member) 16 main body (toner containing member) 18 agitator (stirring unit) 30 toner sensor (remaining amount detecting unit) 32 cleaning member (removal member) 40 switch member (rotational position) Detection means) 42 motor (rotation driving means) 44 transfer device 48 control circuit (control means) 52 spacer (moving member)

Claims (4)

[Claims] A toner accommodating member for accommodating the toner; an agitating unit for agitating the toner accommodated in the toner accommodating member; and a remaining amount detecting unit for detecting a remaining amount of the toner accommodated in the toner accommodating member. A removing member that is provided in the stirring means and removes toner adhered to the detection surface of the remaining amount detecting means by driving the stirring means; and when the driving of the stirring means is stopped, the removing member is located on the bottom of the toner storage member. And a control means for stopping the stirring means so as to be positioned. 2. A moving member which is attached to the removing member and moves within the toner contained in the toner containing member by driving the stirring means to form a region where the density of the toner is low. The toner supply device according to claim 1. 3. An agitator, wherein the stirring means is disposed in the toner storage member and stirs the toner by rotation.
Rotation driving means for rotating the agitator,
The control unit includes: a rotation position detection unit that detects a rotation position of the agitator; and a control circuit that controls the rotation driving unit based on the rotation position of the agitator detected by the rotation position detection unit. 3. The toner replenishing device according to claim 1, wherein: 4. A photosensitive member on which an electrostatic latent image corresponding to image information is formed; a developing device for forming a toner image by attaching toner to the electrostatic latent image on the photosensitive member; 4. A transfer device for transferring a toner image formed on the photosensitive member to an image forming medium, and a toner supply device according to claim 1, which supplies toner to the developing device. Characteristic image forming apparatus.