JPH11133719A - Developer amount detecting device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer amount detecting device capable of always accurately detecting the residual amount of developer. SOLUTION: In this developer amount detecting device detecting the residual amount of toner by making a float (developer amount and position detection member) 11 follow up the movement of the level position of toner (developer) in a toner container (developer storing part) 3 and detecting the position of the float 11; a stirring member 4 is rotated in contact with the float 11 so as to press back the float 11 when the residual amount of the toner in the container 3 is decreased to be equal to or under a specified value. Even when there is possibility that the float 11 is embedded in the toner, the member 4 is rotated in contact with the float 11 so as to press back the float 11, so that the float 11 is not embedded in the toner. when the contact of the float 11 with the member 4 is released thereafter, the float 11 falls on the upper level of the toner and grasps the level of the toner, whereby the residual amount of the toner is accurately detected even when the residual amount of the toner is small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer amount detecting device for detecting a remaining amount of a developer in a developer accommodating portion of a developing device used for an image forming apparatus such as a copying machine or a laser beam printer using an electrophotographic system. The present invention relates to an apparatus and a process cartridge using the same.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, if the image forming apparatus is used for a long time, a photosensitive drum or a developing device as an image carrier is replaced, toner as a developer is supplied, and a charging device is discharged. Cleaning of the wires, replacement of the cleaning container in which the waste toner is stored, adjustment and replacement of devices around the photosensitive drum, and the like were required.

[0003] However, maintenance such as that described above requires specialized skills and knowledge, and maintenance is not easy for ordinary users.

Therefore, the photosensitive drum and the process equipment such as a developing device, a charger, and a cleaning device are integrally assembled in a cartridge container, and are removably mounted as a process cartridge in the main body of the image forming apparatus. When it becomes necessary, it has been proposed to replace the entire process cartridge to facilitate maintenance, and it has already been put to practical use.

[0005] Incidentally, the process cartridge needs to be replaced with a new one when the toner previously stored in the process cartridge is used up, and it is possible to cope with sudden running out of toner by making the user always grasp the remaining toner amount.

Therefore, a toner remaining amount detecting device for detecting the remaining amount of toner in the toner container is provided inside the toner container. Here, an example of a conventional toner sequential remaining amount detecting device is shown in FIGS.

FIG. 5 is a cross-sectional view of a process cartridge provided with a conventional successive toner remaining amount detecting device, FIG. 6 is a diagram showing a main portion of the conventional successive toner remaining amount detecting device, and FIG. FIG. 3 is a cross-sectional view taken along line A. The toner sequential remaining amount detection device is configured to cause a float 11 as a developer amount position detection member supported by a float arm 12 as a rotation member to follow the movement of the upper surface position of the toner. A method of sequentially detecting the remaining amount is adopted.

As a method of causing the float 11 to catch the toner surface, in this embodiment, a float arm 12 is attached to a float shaft 13 which is a rotation shaft inside the toner container 3 and the float arm 13 is attached to the outside of the toner container 3. A recovery lever 100 is attached to the extending end so that the rotational positions (rotation angles) of both do not change.

Before the process cartridge is mounted on the main body of the image forming apparatus, the user is required to set the recovery lever 1
By raising 00, float 11 before use
Can be captured again by the float 11 even if the toner surface is buried in the toner. During use, the float 11 is lowered as shown in FIG. 5 from (A) to (B).
Rotates following the toner surface in the direction of arrow Ya.

[0010]

However, the above-described conventional toner sequential remaining amount detecting device has the following problems.

That is, as the toner surface captured by the float 11 approaches the agitating member 4, the toner surface starts to be affected by the agitation, and the surface of the toner 11 becomes undulated and becomes soft. Therefore, the remaining amount of toner in the toner container 3 cannot be accurately detected.

In order to enable detection even when the remaining amount of toner becomes smaller, as shown in FIG. 8, the position of the float shaft 13 is lowered so that the orbit of the float 11 and the stirring member 4 When the stirring member 4 contacts the float 11 when the rotation direction of the stirring member 4 is in the direction of the arrow Yb, the float 11
In this case, the remaining amount of toner in the toner container 3 cannot be accurately detected.

Further, when the position of the float shaft 13 is lowered to cross the trajectory of the float 11 and the trajectory of the stirring member 4 as described above, the float 11 hits the toner container 3 and stops as shown in FIG. When the stirring member 4 is in the direction of the arrow Y
When the stirring member 4 continues to rotate in the direction c and hits the float 11, the stirring member 4 tries to push the float 11 in the direction of the arrow Ya (the point of action of the force exerted on the float 11 by the stirring member 4 is the center of the float 11 in FIG. 9). More to the right). However, since the escape path of the float 11 is blocked by the toner container 3, the stirring member 4 is eventually
It will not work properly after hitting.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a developer amount detecting device capable of always accurately detecting the remaining amount of developer and a process cartridge provided with the same. It is in.

[0015]

According to the first aspect of the present invention, a developer amount position detecting member is provided near an upper surface of a developer contained in a developer containing portion of a developing means. The developer amount position detecting member is made to follow the movement of the upper surface position of the developer in the developer accommodating portion due to the consumption of the developer, and the position of the developer amount position detecting member is detected, whereby the remaining amount of the developer is detected. When the remaining amount of the developer in the developer accommodating portion of the developing unit decreases to a predetermined value or less, the agitating member contacts the developer position detecting member and rotates to cause the development. It is characterized in that the agent position detecting member is configured to be pushed back.

According to a second aspect of the present invention, in the first aspect of the present invention, the developer position detecting member is moved so as to avoid the movement of the stirring member.

According to a third aspect of the present invention, in the second aspect of the invention, the developer position detecting member receives the power from the agitating member and performs an avoiding movement.

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, when the detecting operation of the developer position detecting member is completed, the developing device is stopped by a part of the developer accommodating portion or a stop member. The developer position detecting member is prevented from moving, and the developer position detecting member is stopped at a position that does not hinder the operation of the stirring member.

According to a fifth aspect of the present invention, there is provided an image forming apparatus, comprising: an image carrier; and at least a developing device as a process device acting on the image carrier. A developer amount position detecting member and a stirring member are provided in the developer accommodating portion, and the developer amount position detecting member follows the movement of the upper surface position of the developer in the developer accommodating portion as the developer is consumed. In a process cartridge provided with a developer amount detecting device that detects a remaining amount of developer by detecting a position of an amount position detecting member, when the remaining amount of developer in a developer accommodating portion of the developing unit decreases to a predetermined value or less, The developer position detecting member is pushed back by rotating the stirring member in contact with the developer position detecting member.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the developer position detecting member is caused to move so as not to hinder the movement of the stirring member.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the developer position detecting member receives the power from the agitating member and performs an avoiding movement.

According to an eighth aspect of the present invention, in the fifth, sixth or seventh aspect of the invention, when the detecting operation of the developer position detecting member is completed, the developing operation is performed by a part of the developer accommodating portion or a stop member. The developer position detecting member is prevented from moving, and the developer position detecting member is stopped at a position that does not hinder the operation of the stirring member.

Therefore, according to the present invention, the remaining amount of the developer in the developer accommodating portion of the developing means is reduced to a predetermined value or less, and the upper surface of the developer in the developer accommodating portion is affected by the stirring effect of the stirring member. Even when the developer position detecting member may be buried in the developer due to being softened by receiving the toner, the developer position is detected by rotating the stirring member in contact with the developer position detecting member. Since the detection member is pushed back, the developer position detection member does not become buried in the developer, and then, when the contact between the stirring member and the developer position detection member is released, the developer position detection member is located above the developer. Since the developer descends to the surface to catch the developer surface, the remaining amount of the developer can be accurately detected even when the remaining amount of the developer is small.

According to the present invention, the operation of the developer position detecting member is terminated at a position where the stirring operation of the stirring member is not hindered. Therefore, even after the detection of the remaining amount of the developer is completed, the stirring member is normally operated. The stirring operation can be continued.

[0025]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1> FIG. 1 is a view showing a cross section of a process cartridge according to the present invention and a state of movement of a float due to toner consumption.

The process cartridge shown in FIG. 1 includes a photosensitive drum 2 serving as an image carrier and a charging roller 1, a developing unit 5, a toner container 3, and a cleaning container 1 disposed around the photosensitive drum 2.
0 and the like are integrated, and are removably mounted on an image forming apparatus main body (not shown) to be used for image formation. The developing device 5 contains the stirring members 6 and 7 and the developing sleeve 8, and the toner container 3 contains the toner and the stirring member 4. The cleaning container 10 is provided with a cleaning blade 9.

The photosensitive drum 2 is driven to rotate at a predetermined speed, the surface thereof is uniformly charged by the charging roller 1, and an image signal generated by an image forming apparatus main body (not shown) is converted into a laser beam. When converted and irradiated on the surface of the photosensitive drum 2, an electrostatic latent image is formed on the surface of the photosensitive drum 2, and the electrostatic latent image is developed by a developing device 5 using toner to form a toner image. It is visualized.

That is, the toner stirred by the stirring member 4 in the toner container 3 of the developing device 5 is transferred to the developing device 5 and further sufficiently stirred by the stirring members 6 and 7, and then transferred from the developing sleeve 8 to the photosensitive drum 2. The supplied electrostatic latent image formed on the photosensitive drum 2 is developed. The toner image formed on the photosensitive drum 2 is transferred to a transfer material (not shown) sent by a paper supply mechanism (not shown) of the image forming apparatus main body, and the toner remaining on the photosensitive drum 2 without being transferred is transferred. Is scraped off by the cleaning blade 9 and collected in the waste toner container 10.

In the toner container 3, there is provided a toner remaining amount detecting device (developer amount detecting device) according to the present invention. One end of the float arm 13 is fixed to one end of the float shaft 13 facing the inside of the toner container 3 (the float shaft 13 and the float arm 12 are integrally formed. The float 11 is fixed to the other end (free end) of the float arm 12.

An angle sensor 15 such as a potentiometer for detecting the amount of rotation of the float 11 is connected to the other end of the float shaft 12 extending outside the toner container 3. Note that the angle sensor 15 is provided on the image forming apparatus main body side, and the angle sensor 15 is connected to the float shaft 13 when the process cartridge is mounted, or the angle sensor 15 is provided on the cartridge side, and an electrical contact (not shown) is provided. A configuration may be employed in which a signal is sent to the image forming apparatus main body via the main unit.

Next, a description will be given of the movement of the toner surface and the float 11 with the decrease of the remaining amount of toner in the toner container 3.

When the toner in the toner container 3 decreases due to the development, the toner surface changes from (A) to (A) as shown in FIG.
It descends in the order of (B) → (C). The float 11 that has initially caught the toner surface (A) also rotates about the float shaft 13 in the direction of the arrow Y1 following the lowering of the toner surface due to toner consumption.

FIG. 2 is a view for explaining the operation when the float 11 is positioned on the track of the stirring member 4.

As shown in FIG. 2A, in a state where the float 11 is on the path of passage of the stirring member 4 and captures the toner surface, the stirring member 4 is moved in the same direction as the arrow Y2 in the rotation direction of the float 11. When the rotation is continued in the direction (the rotation direction is adjusted by a drive gear train (not shown) of the process cartridge), the stirring member 4 comes into contact with the float 11 or the float arm 12 as shown in FIG. When the stirring member 4 continues to rotate as it is in this state, FIG.
As shown in (1), the float 11 is pushed back in the opposite direction along its trajectory and separates from the toner surface. After that, when the contact between the stirring member 4 and the float 11 is released, the float 11 falls again on the toner surface as shown in FIG. In this case, if the float 11 is made of a light material such as a resin, the float 11 can catch the toner surface without sinking into the toner.

When the rotation of the stirring member 4 is continued, the float 11 swings by repeating the above operation. At this time, the angle sensor 15 captures a change in the movement of the float 11 as a periodic change in the angle as shown in FIG. 2D, but holds only the minimum value (when the angle decreases) in the arithmetic processing. By performing the processing as described above, the position of the toner surface, that is, the accurate remaining amount of the toner can be grasped.

When the remaining amount of toner in the toner container 3 further decreases, the float 11 follows the rotation and rotates in the direction of arrow Y1 in FIG. 1, but the toner surface is shown in FIG. Since the float arm 12 has been lowered to the position C), the float arm 12 is provided with the stopper 1 provided inside the toner container 3.
4, the detection of the remaining amount of toner by the float 11 ends at that time. At the position where the detection of the remaining amount of toner is completed, if the point of action of the force exerted on the float 11 of the stirring member 4 is on the side of the float 11 in the direction in which the float 11 advances, the stirring member 4 contacts the float 11. However, since the float 11 can move freely in the returning direction, the float 11 can be pushed back without any problem.

As described above, in the present embodiment,
The float 11 is buried in the toner because the remaining amount of toner in the toner container 3 decreases to a predetermined value or less, and the upper surface of the toner in the toner container 3 becomes soft under the influence of the stirring action of the stirring member 4. Even in a case where there is a possibility that the float 11 is pushed back by the rotation of the stirring member 4 in contact with the float 11, the float 11
Is not buried in the toner. After that, when the contact between the stirring member 4 and the float 11 is released, the float 11 descends to the upper surface of the toner and re-captures the toner surface. Can be detected.

In this embodiment, the float 1
Since the operation 1 ends at a position where the stirring operation of the stirring member 4 is not hindered, the stirring member 4 can normally continue the stirring operation even after the detection of the remaining amount of toner is completed.

<Embodiment 2> Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a diagram showing a cross section of the toner container of the process cartridge according to the present invention and a moving state of the float due to toner consumption, and FIG. 4 is an operation of the toner remaining amount detecting device (developer amount detecting device) according to the present invention. It is an explanatory view, in these figures, the same elements as those shown in FIGS. 1 and 2 are denoted by the same reference numerals,
Hereinafter, the description thereof will be omitted.

In the present embodiment, a gear 22 meshes with an agitating gear 20 for transmitting a driving force to the agitating member 4 via an idler gear 21, and a contact member 23 is coaxial with the gear 22. Are bound.

A contact member 24 for selectively contacting the contact member 23 is provided at an end of the float shaft 13.
3 and coaxially.

The contact members 23 and 24, which are coaxially connected to the gear 22 and the float shaft 13, respectively, are mounted at positions such that the tips thereof abut when the gear 22 and the float shaft 13 rotate. Has been adjusted. 3 and 4, the gears 20, 21, 22 and the contact members 23, 2
4 and the inside of the toner container 3 are illustrated in an overlapping manner, but the gears 20, 21, 22 and the contact members 23, 24 are
Is provided outside.

In the above, when the float 11 is sufficiently separated from the trajectory of the stirring member 4 as shown in FIG.
The contact members 23 and 24 do not contact each other.

As the toner in the toner container 3 is consumed, the float 11 rotates around the float shaft 13 following the lowering of the toner surface, and as shown in FIG. Is positioned on the track of the stirring member 4, the contact members 23, 2 are placed before the stirring member 4 contacts the float 11.
4 come into contact with each other, and from the stirring gear 20 to the idler gear 21,
Float shaft 13 through gear 22 and contact members 23 and 24
Then, as shown in FIG. 4B, the float 11 can be returned to the direction in which the float 11 came so that the float 11 does not come into contact with the stirring member 4.

Then, the stirring member 4 passes and the float 1
The contact state of the contact members 23 and 24 is released at a point away from the first track, and the float 11 captures the upper surface of the toner, thereby enabling accurate detection of the remaining toner amount.

As another method for avoiding the float 11 from coming into contact with the stirring member 4 in synchronization with the movement of the stirring member 4 as described above, a cam, a toothless gear, or the like is used instead of the contact members 23 and 24. The configuration used may be adopted.

[0048]

As is apparent from the above description, according to the present invention, the remaining amount of the developer in the developer accommodating portion of the developing means is reduced to a predetermined value or less, and the upper surface of the developer in the developer accommodating portion is reduced. When the developer is softened by the stirring effect of the stirring member and the developer position detecting member may be buried in the developer, the stirring member contacts the developer position detecting member. The developer position detecting member is pushed back by rotating the developer position detecting member, so that the developer position detecting member does not become buried in the developer. Thereafter, when the contact between the stirring member and the developer position detecting member is released, the developing The developer position detecting member descends to the upper surface of the developer and captures the developer surface, so that even if the remaining amount of the developer is small, the effect that the remaining amount of the developer can be accurately detected can be obtained.

Further, according to the present invention, since the operation of the developer position detecting member is terminated at a position where the stirring operation of the stirring member is not hindered, the stirring member is normally operated even after the detection of the remaining amount of the developer is completed. The effect that the stirring operation can be continued can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cross section of a process cartridge according to a first embodiment of the present invention and a movement state of a float due to toner consumption.

FIG. 2 is an explanatory diagram of an operation of a toner sequential remaining amount detecting device (a developer amount detecting device) according to the first embodiment of the present invention;

FIG. 3 is a diagram illustrating a cross section of a toner container of a process cartridge according to Embodiment 2 of the present invention and a movement state of a float due to toner consumption.

FIG. 4 is an operation explanatory diagram of a toner remaining amount sequential detecting device (developer amount detecting device) according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a process cartridge including a conventional sequential toner remaining amount detecting device (developing agent amount detecting device).

FIG. 6 is a diagram illustrating a main part of a conventional toner sequential remaining amount detection device (developer amount detection device).

FIG. 7 is a sectional view taken along line AA of FIG. 7;

FIG. 8 is a cross-sectional view of a process cartridge including a conventional toner sequential remaining amount detection device (developer amount detection device).

FIG. 9 is a cross-sectional view of a process cartridge including a conventional toner sequential remaining amount detecting device (developing agent amount detecting device).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charging roller (process means) 2 Photosensitive drum (image carrier) 3 Toner container (developer accommodating part) 4 Stirring member 5 Developing device (developing means: process means) 11 Float (developer position detecting member) 12 Float arm 13 Float shaft 14 Stopper (stop member) 15 Angle sensor 20 Stirring gear 21 Idler gear 22 Gear 23, 24 Contact member

Claims (8)

[Claims] 1. A developer amount position detecting member is disposed near an upper surface of a developer accommodated in a developer accommodating section of a developing means, and an upper surface of the developer in the developer accommodating section accompanying consumption of the developer. In the developer amount detecting device which causes the developer amount position detecting member to follow the movement of the position, and detects the remaining amount of the developer by detecting the position of the developer amount position detecting member, When the remaining amount of the developer in the unit decreases to a predetermined value or less, the stirring member contacts the developer position detecting member and rotates to push back the developer position detecting member, so that the developer amount Detection device. 2. The developer amount detecting device according to claim 1, wherein the developer position detecting member is caused to move so as not to hinder the movement of the stirring member. 3. The developer amount detecting device according to claim 2, wherein the developer position detecting member receives the power from the stirring member and performs an avoiding movement. 4. When the detection operation of the developer position detecting member is completed, the movement of the developer position detecting member is prevented by a part of the developer accommodating portion or a stop member, and the developer position detecting member is moved. The developer amount detecting device according to claim 1, wherein the developer amount is stopped at a position where the operation of the stirring member is not hindered. 5. A developing device which is detachably attached to an image forming apparatus main body, has an image carrier, and at least a developing device as a process device acting on the image carrier, and a developer is contained in a developer accommodating portion of the developing device. An amount position detecting member and a stirring member are provided, and the developer amount position detecting member is made to follow the movement of the upper surface position of the developer in the developer accommodating portion due to the consumption of the developer. In the process cartridge provided with a developer amount detecting device for detecting the remaining amount of the developer by detecting the developer amount, when the remaining amount of the developer in the developer accommodating portion of the developing unit decreases to a predetermined value or less, the agitating member causes the developer. A process cartridge configured to push back the developer position detecting member by rotating in contact with the position detecting member. 6. The process cartridge according to claim 5, wherein the developer position detecting member is caused to move so as not to hinder the movement of the stirring member. 7. The process cartridge according to claim 6, wherein the developer position detecting member receives the power from the stirring member and performs an avoiding movement. 8. When the detection operation of the developer position detecting member is completed, the movement of the developer position detecting member is prevented by a part of the developer accommodating portion or a stop member, and the developer position detecting member is moved. 8. The process cartridge according to claim 5, wherein the process cartridge is stopped at a position where the operation of the stirring member is not hindered.