JP2002169368A - Toner replenishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate adhesion of toner or soiling due to the toner by controlling the toner residual in a toner tank from the outside of the toner tank. SOLUTION: The rotary shaft 26 of a stirring body 25 for stirring the toner in the toner tank 20 is extended to the outside of the toner tank 20, and a flywheel 28 is attached to one end of the shaft 26. A driving body 31 is driven and rotated facing to the flywheel 28 in such way that it is engaged with a pin 29 projectingly provided on the flywheel 28 so as to rotate the stirring body 25. When the stirring member 27 of the stirring body 25 passes through an upper dead point, the pin 29 is separated from the driving body 31 and the stirring body 25 is rotated toward a lower dead point by gravity. When the stirring member 27 comes into contact with the toner remaining in the toner tank 20, its rotation is stopped. Since the flywheel 28 is rotated and stopped interlocking with the movement of the stirring body 25, the toner amount in the toner tank 20 is discriminated by the movement of the flywheel 28 detected by a photosensor 42.

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 used in an electrophotographic image forming apparatus, and more particularly, to a toner replenishing device having a function of detecting a remaining amount of toner.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic process, such as a copying machine, a printer, and a facsimile machine, an electrostatic latent image is formed by performing image exposure on a photoreceptor uniformly charged in advance. The electrostatic latent image is developed with toner supplied from a developing device to form a visible image (toner image), and the toner image is transferred and fixed on transfer paper. Along with placing the developing roller, agitator, etc. in the developing tank of the developing device,
A toner replenishing device is arranged adjacent to the developing tank. The toner replenishing device is controlled to replenish the toner from the toner tank to the developing tank when the toner concentration of the developer contained in the developing tank decreases.

Here, generally, optical means are often used to detect the remaining amount of toner in the toner tank or the presence or absence of toner. For example, in Japanese Patent Application Laid-Open No. Hei 5-27593, as shown in FIG. 25, transparent windows are provided on opposite side walls of a toner tank 1 containing toner, and a light emitting diode (LED) 2 is provided outside one of the transparent windows. And place
The photodiode 3 is arranged outside the other transparent window,
A configuration is disclosed in which whether or not the toner amount is a predetermined amount is determined based on whether or not the toner amount in the toner tank 1 is at a level that exceeds the optical path from the LED 2 to the photodiode 3.

Japanese Patent Application Laid-Open No. 9-80892 discloses that
As shown in FIG. 26, a transparent window 5 is formed at the bottom of the toner container 4, while a reflection plate is provided on a stirring member 6 rotating in the toner container 4, and a reflection plate is provided outside the transparent window 5 through the transparent window 5. There is disclosed a configuration in which a reflection-type photosensor 7 that irradiates light and receives reflected light from a reflection plate to detect whether or not toner remains in the toner container 4 based on the presence or absence of reflected light. I have.

However, in the former configuration, it is necessary to provide two transparent windows in the toner tank, and if the transparent windows are contaminated with toner and an optical path failure occurs, erroneous detection may occur. Also, in the latter configuration, the number of transparent windows to be installed can be reduced, but also when the reflection plate is contaminated with toner,
The toner detection accuracy decreases.

A configuration disclosed in Japanese Patent Application Laid-Open No. Hei 5-11610 is known as one which avoids malfunctions caused by toner contamination. As shown in FIG. 27, a portal stirrer 9 made of a magnetic material that receives the resistance of toner during rotation is rotatably supported by a stirring shaft 10 inside the toner container 8, and outside the toner container 8, A sensor lever 12 having a permanent magnet 11 on which a magnetic attraction force acts between the stirrer 9 and the sensor lever 12 is provided rotatably.
Is provided with a transmission type optical sensor 14 for detecting passage of the light shielding piece 13 formed in the light emitting element.

In this configuration, when the stirrer 9 reaches the top dead center when the stirrer 9 rotates with the rotation of the stirring shaft 10, the stirrer 9 descends by its own weight. At this time, the stop position changes depending on the amount of toner in the toner container 8. The on / off time of the optical sensor 14 varies depending on the displacement of the sensor lever 12 that responds to the stirrer 9 via the permanent magnet 11. By comparing this time,
The toner amount is detected.

[0008]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 5-116 is disclosed.
According to the technology described in Japanese Patent Application Publication No. 10-210, erroneous detection due to the influence of toner contamination can be avoided, but the number of components such as a permanent magnet on which a magnetic attraction force from a stirrer acts and a sensor lever that blocks an optical path of an optical sensor increases. I do. In addition, since a relatively large sensor lever or the like is provided outside the toner container, the size of the entire apparatus is increased. In particular, since the displacement of the stirrer is transmitted to the sensor lever via the permanent magnet, the displacement of the sensor lever tends to be slightly delayed with respect to the displacement of the stirrer. It is difficult to clearly determine the time to perform, and the detection accuracy of the toner amount is inferior.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a toner replenishing apparatus which has a simple structure, is compact, and has a detection function capable of accurately detecting the amount of toner.

[0010]

Means for Solving the Problems According to the present invention, one end of a rotating shaft of a stirring member provided in a toner tank is extended to the outside of the toner tank, and a driven member is integrally formed with one end of the rotating shaft. A driving body is provided, which is detachable from the driven body. When both are engaged with each other, a rotational driving force is transmitted to a rotating shaft, and when the driven body is separated from the driving body, the inside of the toner tank is removed. Is to detect the amount of toner by detecting the movement of the stirring member in accordance with the amount of toner. That is, when the agitating body rotates toward the bottom dead center by its own weight beyond the top dead center and stops at a position corresponding to the toner amount, a means for detecting the movement of the driven body linked to this movement is utilized. Is provided.

The stirrer has a frame-shaped stirrer protruding radially from the rotation axis, and the center of gravity of the stirrer is eccentric from the rotation axis. Accordingly, when the stirring member passes through the top dead center, the stirring member rotates toward the bottom dead center by its own weight. Also, if the stirring member is formed in a frame shape,
The weight can be reduced, and the load on the drive mechanism can be reduced. Furthermore, when the stirring member descends by its own weight and comes into contact with the toner, if it is heavy, it will settle without stopping on the toner,
Although an accurate toner amount cannot be detected, such a case cannot occur by reducing the weight, and the reliability of the detection can be improved.

The driven body is a disk having a pin protruding therefrom, and the driving body is a cam abutting on the pin. The cam is
The shape of the stirring member is not limited as long as the stirring member of the stirring member can be engaged with the pin until the stirring member reaches the top dead center to transmit the rotational driving force. If the pins of the disk are arranged on the axial extension of the center of gravity of the stirrer, the positioning of the driving body and the driven body during mounting can be easily performed.

The other driven member is a driven gear, and a driving member is a driving gear that meshes with the driven gear. By forming a toothless part in a part of the driving gear, the driven body separates from the driving body when the toothless part faces the driven gear, so that a mechanism for freely lowering the stirring member can be simplified. No complicated drive control is required. Here, the number of teeth of the driving gear is set to the number of teeth for rotating the driven gear more than half a turn. In this case, the direction in which the stirring member descends is always one direction, and there is no need to use a complicated component such as a one-way clutch.

[0014] The toner detecting means is provided with a detected part on a driven member for transmitting the movement of the stirring member in the toner tank to the outside of the toner tank.
A detection sensor for detecting the movement or the position of the detected portion; and a discriminating means for discriminating a toner amount based on a detection result of the detection sensor, wherein the discriminating means detects the rotation of the driven body detected by the detection sensor. Based on the speed change, it is determined that the toner amount is smaller as the rotation speed is larger, or it is determined that the toner amount is smaller as the stop time is longer based on the stop time of the driven body detected by the detection sensor. Further, a detected portion stopped at a position corresponding to the stop position of the stirring member is detected, and the amount of toner is determined.

As the detection sensor, either a non-contact type sensor or a contact type sensor may be used, but a non-contact type sensor such as an optical sensor, a magnetic sensor or the like is suitable. Detection can be performed. In the case where an optical sensor is used, the detected portion is a through-hole or a reflection member provided near the outer periphery of the disk. When a magnetic sensor is used, it is a magnetic member provided near the outer periphery of the disk. One or a plurality of these may be provided. When a plurality of these are provided, they are arranged at regular intervals along the outer circumference.

[0016]

(First Embodiment) FIG. 1 shows a schematic configuration of a toner supply device according to a first embodiment. The drawings are
Since the internal configuration of the toner replenishing device is shown, the upper and side walls of the outer wall of the device are omitted. The toner replenishing device is disposed in an image forming apparatus such as a copying machine or a printer of an electrophotographic process in a state where the toner replenishing device is connected to a developing device (not shown), and is provided with a one-component developer or a two-component developer. When the toner in the device is low,
It operates in response to a toner replenishment signal based on a toner concentration detection signal of a toner sensor to supply the toner in the toner tank 20 to the developing device.

The toner tank 20 has a shape in which a toner storage chamber 21 and a toner supply chamber 22 are connected. The toner supply chamber 22 has a slit-shaped toner drop port 23 formed therein, and communicates with the inside of the developing device. A supply roller 24 composed of a sponge roller or the like is provided inside, and is rotatably supported on the side wall. When supplying toner to the developing device, the supply roller 24 is driven to rotate by a motor, adsorbs the toner on the surface of the supply roller 24, and supplies the toner from the toner dropping port 23 to the developing device.

The toner storage chamber 21 stores the toner before being supplied to the developing device, and is provided with an agitator 25. The stirrer 25 mixes the collected reusable toner (untransferred toner) and new toner in a device that prevents aggregation of toner in a room or enables reuse of toner. In addition, on the upper wall of the toner storage chamber 21,
An openable and closable lid for supplying toner is provided.

The stirrer 25 includes a rotating shaft 26 rotatably supported on the side wall and a stirring member 27 provided integrally with the rotating shaft 26.
The toner in the room is stirred and the stirred toner is sent to the toner supply chamber 22 side. The stirring member 27 is
The U-shaped frame is attached to the rotating shaft 26 in the radial direction. By forming the stirring member 27 in a frame shape, the weight can be reduced, the rotation load of the rotating shaft 26 does not greatly increase at the time of stirring the toner, and the stirring performance can be exhibited well.

One end of the rotating shaft 26 extends through the side wall to the outside of the toner tank 20, and a disc-shaped flywheel 28 is integrally attached to one end of the rotating shaft 26. One pin 29 protrudes from the outer surface of the flywheel 28, and the pin 29 and the stirring member 27 have the same angular position with respect to the rotating shaft 26, that is, the pin 29 is located on the axial extension of the stirring member 27. positioned. Accordingly, the position of the center of gravity of the stirring body 25 is a position eccentric from the rotation shaft 26 on this extension line.

In order to transmit a rotational driving force to a driven body 30 comprising a flywheel 28 having a pin 29, a driving body 31 is arranged opposite to the flywheel 28. The driving body 31 and the driven body 30 constitute a driving mechanism for rotationally driving the stirring body 25. The driving body 31 is a half-moon-shaped cam attached to the tip of a driving shaft 32 of a driving source such as a motor or a gear (not shown), and is adapted to be disengaged from the pin 29. That is,
When the driving body 31 is in the engaged state in contact with the pin 29, the rotational driving force is transmitted from the driving body 31 to the stirring body 25, and
At the time of the detached state away from 9, the rotational driving force is not transmitted.

Here, the relationship between the rotation of the driving body 31 and the rotation of the stirring body 25 will be described. First, as shown in FIG. 2, a state in which the stirring member 27 is at the position of the bottom dead center and the driving body 31 is in contact with the pin 29 is set as a start state. When the driving body 31 rotates clockwise, the flywheel 28 rotates via the pin 29, and accordingly, the stirring member 27 rotates while stirring the toner. As shown in FIG. 3, when the driving body 31 rotates 1/4 and further rotates, the stirring member 27 lifts the toner and sends it to the toner supply chamber 22.

When the driving body 31 makes a half turn,
As shown in FIG. 4, the stirring member 27 reaches the top dead center. Since the center of gravity of the stirrer 25 is above the rotation shaft 26, when the stirrer 27 slightly exceeds the top dead center, the stirrer 25 rotates toward the bottom dead center by its own weight. At this time, since the rotation speed of the driving body 31 is set to be lower than the rotation speed of the agitating body 25 descending by its own weight, the rotation of the driving body 31 cannot catch up with the movement of the pin 29, and Leaves. When the stirring member 27 rides on the toner, the rotation of the stirring member 25 stops. Thereafter, when the driving body 31 rotates and comes into contact with the pin 29 as shown in FIG. 5, the stirring body 25 starts to rotate again.

When the amount of toner in the toner tank 20 is small, the same movement as described above is performed until the stirring member 27 reaches the top dead center, as shown in FIGS. Stirring member 27
Exceeds the top dead center, the stirring member 27 rotates by its own weight. However, since the toner amount is small, the stirring member 27 does not receive the resistance of the toner and immediately reaches the bottom dead center. for that reason,
As shown in FIG. 9, even if the driving body 31 rotates 3/4, it does not come into contact with the pin 29, and no rotational driving force is transmitted. When the driving body 31 reaches the position shown in FIG. 6 again, it comes into contact with the pin 29 and the rotation of the stirring body 25 is restarted.

If the mass of the stirring member 27 is large, the force acting in the direction of falling by its own weight exceeds the resistance force of the toner, and accurate detection of the remaining amount cannot be performed when the amount of toner is small. For this reason, it is necessary to make the stirring member 27 as lightweight as possible. In the case of metal, it is preferable to form the stirring member 27 with a thin metal wire having a thickness of about 0.5 to 1 mm.

As described above, the maximum descending speed until the stirring member 27 descends beyond the top dead center and stops, that is, the maximum rotational speed of the flywheel 28, increases as the descending distance increases, and the toner amount decreases. Large when small. Also,
After the agitating member 27 descends beyond the top dead center and stops, the stop period until the rotation is restarted becomes longer as the toner amount is smaller. Therefore, the rotation state of the flywheel 28 interlocked with the stirring member 27 varies depending on the remaining amount of toner in the toner tank 20.
Can be detected.

In order to detect the amount of toner in the toner tank 20, there is provided a toner detecting means for detecting the movement of the flywheel 28 which changes according to the amount of toner. The toner detecting means includes a detecting sensor provided on the flywheel 28 for detecting the movement of the flywheel 28 for detecting a detected portion, and a determining means for determining a toner amount based on a detection result of the detecting sensor. . As shown in FIGS. 1 and 10, the detection sensor is a transmission type optical sensor 42 in which a light emitting element 40 and a light receiving element 41 are arranged opposite to each other with the flywheel 28 interposed therebetween, that is, a so-called photo interrupter. Output to the control device of the device. The determination means 43 of the control device determines the amount of toner, and when detecting the absence of toner, displays a message prompting toner supply on a display unit or the like of the image forming apparatus.

The detected portions are through holes 44 formed near the outer periphery of the flywheel 28, and a plurality of detected portions are arranged at a predetermined pitch. The optical sensor 42 is arranged such that the optical path is on the pitch circle of the through hole 44 and is not in contact with the pin 29. When the through hole 44 exists on the optical path of the optical sensor 42, the optical sensor 42 is turned on,
It is turned off when the through hole 44 does not exist. Thus, by monitoring the on / off timing of the optical sensor 42, the rotation speed, the stop time, and the like of the flywheel 28 can be detected.

FIG. 11 shows the configuration of another detection sensor. A reflection type optical sensor 45 is used as a detection sensor, and the detected portion is a reflection member 46 such as a metal plate arranged near the outer periphery of the flywheel 28. As shown in FIG. 11A, when a plurality of reflection members 36 are attached to the outer surface of the flywheel 28 at a predetermined pitch, the optical sensor 45
Is disposed so as to face the outer surface of the flywheel 28. Further, as shown in FIG. 3B, when a plurality of reflection members 46 are attached to the outer peripheral surface of the flywheel 28 at a predetermined pitch, the optical sensor 45
8 are arranged so as to face the outer peripheral surface. Optical sensor 45
When the reflection member 46 is opposed to the optical sensor 45, the optical sensor 45 is turned on, and when not, the optical sensor 45 is turned off. In this way, the rotation speed and the stop time of the flywheel 28 can be detected from the ON / OFF timing of the optical sensor 45.

As for the relationship between the output of each optical sensor and the amount of toner in the toner tank 20, the ON / OFF of the optical sensor is constant until the stirring member 27 reaches the top dead center.
After the stirring member 27 exceeds the top dead center, the ON / OFF interval of the optical sensor increases as the stirring member 27 descends. When the stirring member 27 comes into contact with the toner and stops, the optical sensor remains on or off. This state continues until the driver 31 contacts the pin 29 again.

Therefore, since the number of times the optical sensor is turned on and off is proportional to the descending speed of the stirring member 27, the number of times the optical sensor is turned on and off until the stirring member 27 stops is counted, and the counted number is set as a set value. Compare. If the count number is large, it is determined that the toner amount is small, and the notification of the absence of toner is performed. If the count is small, it is determined that the toner amount is sufficient. Alternatively, a table in which the number of ON / OFF of the optical sensor is measured by changing the amount of toner in advance is created, and the remaining amount of toner can be known by comparing the actual count number with the value in the table. . Thus, if it is detected that the amount of toner is small, it is preferable to prepare for toner supply.

The amount of toner can also be determined based on the stop time of the stirring member 27. That is, when the stirring member 27 stops, the output of the optical sensor remains on or off and does not change. If the stop time at this time is measured and compared with a set value, it is possible to determine the presence or absence of toner or to detect the amount of toner.

The specification of the number of rotations of the stirring body 25 differs depending on the size of the toner storage chamber 21 and the image forming apparatus used. The number of revolutions of this type of stirring body 25 is set to 10 revolutions per minute or less if it is small, and is set to about 10 several revolutions per minute at most. That is, since the movement of the flywheel 28 is performed at a relatively low speed, the change in the movement of the flywheel 28 can be accurately detected, and the detection of the change in the rotation speed and the stay time (stop time) of the flywheel 28 due to the contact of the stirring member 27 with the toner. Easy to do. For example, assuming that the rotation speed of the stirring body 25 is set to 10 rotations per minute, when the staying time of the stirring member 27 at the bottom dead center becomes the shortest (when the toner is full),
Once every six seconds, the stirring member 27 passes through the bottom dead center. In the case where the staying time of the stirring member 27 at the bottom dead center is the longest (toner empty state), the stirring member 27 remains stopped for about 3 seconds until the driving body 31 rotates by 回 転. Become.

Next, as another detection sensor, FIG.
As shown in (a) and (b), a magnetic sensor 47 is used instead of the optical sensor, and the detected part is a magnetic member 48 such as an iron plate or a magnet instead of the reflection member. These arrangements are the same as those in the case of the reflection type optical sensor 45 described above. When the magnetic member 48 is opposed to the magnetic sensor 47, the magnetic sensor 47 is turned on. When the magnetic member 48 is not opposed to the magnetic sensor 47, the magnetic sensor 47 is turned off. Therefore, the rotational speed and the stop time of the flywheel 28 are detected from the on / off timing of the magnetic sensor 47. it can.

Output characteristics (operating characteristics) of the magnetic sensor 47
As shown in FIG. 13, when the magnetic member 48 is present in close proximity, the detected magnetic permeability is high, indicating a high output, and when the magnetic member 48 is separated, the output is low. Therefore, by monitoring a change state such as an on / off state based on the level (large or small) of the output value of the magnetic sensor 47 and a length of the continuous time, it is possible to detect the approach or separation of the magnetic member 48 as shown in FIG. . Here, it is sufficient that the on / off of the sensor output is detected as the frequency of occurrence of a magnetic field change (the rotation speed of the flywheel 28).

Assuming that the time required for the flywheel 28 to rotate by one pitch of the magnetic member 48 is T, when the rotation speed of the flywheel 28 is low, FIG.
As shown in the figure, since the period in which the magnetic sensor 47 and the magnetic member 48 face each other is long, that is, the change is slow,
The output change of the magnetic sensor 47 has a long on / off switching interval and a long duration of sensor output on. Conversely, when the rotation speed of the flywheel 28 is high, as shown in FIG.
8 is short, that is, changes are frequent, so that the output change of the magnetic sensor 47 has a short on-off switching interval and a short period of sensor output on.

As described above, even if the magnetic sensor 47 is used, it is possible to determine the presence or absence of toner or the amount of toner by measuring the number of on / off times and the time during which the output does not change, as in the case of the optical sensor described above. it can.

(Second Embodiment) In the toner supply device of the present embodiment, as shown in FIG.
5, and the driving mechanism is different from that of the first embodiment. Other configurations are the same as those of the first embodiment. The driving body 31 of the toner replenishing device is a driving gear 50 attached to the tip of a driving shaft 32 of a driving source, and the driven body 30 is a driven gear 51 that meshes with the driving gear 50. Rotating shaft 26 protruding outside
Attached to one end. In addition, the driven gear 51
A disc 52 having a larger diameter than this is integrally attached.

A toothless portion 53 is formed in a part of the driving gear 50. When the toothless portion 53 faces the driven gear 51, the driven gear 51 is separated from the driving gear 50, and the rotational driving force is generated. Is not transmitted. This tooth missing part 53
Is formed at a position facing the stirring member 27, so that when the stirring member 27 reaches the top dead center, the start end of the toothless portion 53 is engaged with the driven gear 51.

As shown in FIGS.
When the drive gear 50 rotates clockwise while the drive gear 51 is at the position of the bottom dead center, the driven gear 51 rotates, and accordingly, the stirring member 27 rotates while stirring the toner. Stirring member 2
When the motor 7 reaches the top dead center, the driving gear 50 meshes with the driven gear 51 as shown in FIG. 19, but when the driving gear 7 exceeds the top dead center, as shown in FIG. The start end is applied to the driven gear 51, and the driven gear 51 is separated from the driving gear 50. Then, since the center of gravity of the stirrer 25 is above the rotation shaft 26, the stirrer 25 rotates toward the bottom dead center by its own weight. When the stirring member 27 rides on the toner, the rotation of the stirring member 25 stops, and then, when the driving gear 50 rotates and the end of the toothless portion 53 passes,
The driving gear 50 meshes with the driven gear 51, and the stirring body 25 starts rotating again.

Further, a toner detecting means including a detecting sensor and a discriminating means is provided. The detection sensor is shown in FIG.
23, a reflection type optical sensor 45 shown in FIG. 22, and a magnetic sensor 47 shown in FIG. When the transmission type optical sensor 42 is used, the detected portion is a through hole 44 formed in the disk 52. When the reflection type optical sensor 45 is used, the detection target is the reflection member 46 attached to the disk 52. When the magnetic sensor 47 is used, the detected part is a magnetic member 48 attached to the disk 52. These configurations and operations are the same as those of the first embodiment.

FIG. 24 shows a speed change when the stirring member 27 rotates. (A) shows a normal case in which toner is present in the toner storage chamber 21, and (b) shows a state in which the amount of toner is small, and it is necessary to newly supply toner.

The stirring member 27 rotates at a constant speed until the top dead center is reached. When you start to descend after passing through the top dead center,
The speed gradually increases, and immediately after contact with the toner or when the bottom dead center is reached, the speed sharply decreases, and then the stirring member 27 stops. Triggered by the arrival timing of the stirring member 27 to the stop position, the time until the stirring body 25 is driven again by the driving gear 50 is detected as to whether or not the time is near the time threshold, so that the inside of the toner tank 20 is detected. Can be determined.

As shown in FIG. 24A, the toner tank 2
When the amount of toner within 0 is relatively large, the time during which the stirring member 25 is driven via the driving gear 50 becomes longer, so that the sensor output is output only for a short period in which the stirring member 27 passes the position corresponding to the detection sensor. Is turned on or has high output. FIG.
When the amount of toner in the toner tank 20 is relatively small, as in the case of (b), the stirring member 27 stays at the position corresponding to the detection sensor after reaching the bottom dead center for a certain period of time. Longer duration of on or high power. If the duration is longer than the threshold, it is determined that there is no toner.

Further, in a state where the toner is not in the toner tank 20, the frequency of occurrence, such as the number of times of shading, the number of times of reflection, or the number of changes in the magnetic field, when the agitating member 27 descends due to its own weight is measured in advance. The threshold is set in advance. When the descending speed of the stirring member 27 is high, the number and frequency of light blocking of the optical path per unit time, the number and frequency of receiving reflected light or the number and frequency of occurrence of a magnetic field change are large, and when the descending speed is low, , The frequency and number of occurrences thereof are reduced. Thus, the amount of toner in the toner tank 20 can be determined by comparing the number of changes in the output of the detection sensor with a threshold. Alternatively, the maximum rotation speed obtained when the stirring member 27 descends in the absence of toner is set as the speed threshold, and the maximum rotation speed is calculated from the output change of the detection sensor, and it is determined whether or not this speed exceeds the speed threshold. Thus, the toner amount may be detected.

It should be noted that the present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention. For example, the driven body may be provided with one detected portion at a position corresponding to the stirring member, and the position of the detected portion when the stirring member descends and stops due to its own weight may be detected. In this case, a detection result proportional to the amount of toner in the toner tank can be obtained, so that the amount of remaining toner can be accurately recognized.

[0047]

As is apparent from the above description, according to the present invention, the movement of the stirrer, which varies according to the amount of toner in the toner tank, is transmitted directly to the outside of the toner tank via the drive mechanism of the stirrer. The mechanism for transmitting the movement of the agitator to the outside can be simplified, and there is no mechanical loss, so that the detection accuracy can be improved.

Further, since the detecting means for detecting the movement of the agitator can be disposed outside the toner tank, the detection means is not affected by toner adhesion or contamination, and erroneous detection can be eliminated. The toner amount can be accurately detected. In addition, since the stirrer not only stirs the toner but also serves as a detector for detecting the amount of toner, the number of parts can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a main part of a toner supply device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the movement of a stirring member when toner is present in a toner tank and the state of engagement and disengagement of a driven member and a driving member interlocked with the movement of the stirring member.

FIG. 3 is a diagram illustrating the movement of a stirring member when toner is present in a toner tank and the state of engagement and disengagement of a driven member and a driving member interlocked with the movement of the stirring member.

FIG. 4 is a diagram showing the movement of a stirring member when toner is present in a toner tank and the state of engagement and disengagement of a driven member and a driving member interlocked with the movement of the stirring member.

FIG. 5 is a diagram showing the movement of a stirring body when toner is present in a toner tank and the state of engagement and disengagement of a driven body and a driving body interlocked with the movement of the stirring body.

FIG. 6 is a diagram showing the movement of the stirring member when there is no toner in the toner tank and the disengagement state between the driven member and the driving member interlocked with the movement of the stirring member.

FIG. 7 is a diagram showing the movement of the stirring member when there is no toner in the toner tank and the disengagement state of the driven member and the driven member interlocked with the movement of the stirring member.

FIG. 8 is a diagram showing the movement of the stirring member when there is no toner in the toner tank and the disengagement state of the driven member and the driven member interlocked with the movement of the stirring member.

FIG. 9 is a diagram showing the movement of the stirring member when there is no toner in the toner tank and the disengagement state of the driven member and the driving member interlocked with the movement of the stirring member.

10A and 10B show an arrangement of a transmission type optical sensor, where FIG. 10A is a side view and FIG. 10B is a front view.

11A and 11B show an arrangement of a reflection type optical sensor, wherein FIG. 11A shows a case where a detected portion is attached to an outer surface of a disk, and FIG. 11B shows a case where the detected portion is attached to an outer peripheral surface of a disk.

12A and 12B show the arrangement of a magnetic sensor. FIG. 12A shows a case where a detected portion is attached to an outer surface of a disk, and FIG. 12B shows a case where the detected portion is attached to an outer peripheral surface of a disk.

FIG. 13 is a diagram showing output characteristics of a magnetic sensor.

FIG. 14 is a diagram illustrating an output of a magnetic sensor depending on the presence or absence of a detected part;

FIG. 15 is a diagram showing an output of a magnetic sensor depending on a difference in rotation speed of a stirring body.

FIG. 16 is a configuration diagram illustrating a main part of a toner supply device according to a second embodiment.

FIG. 17 is a diagram showing the movement of the stirring body and the disengagement state of the driven body and the driven body interlocked with the movement of the stirring body.

FIG. 18 is a diagram showing the movement of the stirring body and the disengagement state of the driven body and the driven body interlocked with the movement of the stirring body.

FIG. 19 is a diagram showing the movement of the stirring body and the disengagement state of the driven body and the driving body interlocked with the movement of the stirring body.

FIG. 20 is a diagram showing the movement of the stirring body and the disengagement state of the driven body and the driven body interlocked with the movement of the stirring body.

21A and 21B show an arrangement of a transmission type optical sensor, wherein FIG. 21A is a side view, and FIG.

22A and 22B show an arrangement of a reflection type optical sensor, wherein FIG. 22A shows a case where a detected portion is attached to an outer surface of a disk, and FIG.

23A and 23B show an arrangement of a magnetic sensor. FIG. 23A shows a case where a detected part is attached to an outer surface of a disk, and FIG. 23B shows a case where the detected part is attached to an outer peripheral surface of a disk.

FIG. 24 is a diagram showing a relationship between a change in the rotation speed of the stirring member and the output of the detection sensor, and FIG.
(B) when there is no toner

FIG. 25 is a diagram showing a conventional mechanism for detecting the amount of toner.

FIG. 26 is a diagram showing a conventional mechanism for detecting the amount of toner.

FIG. 27 is a diagram showing a conventional mechanism for detecting the amount of toner.

[Explanation of symbols]

 Reference Signs List 20 toner tank 25 stirrer 26 rotating shaft 27 stirrer 28 flywheel 29 pin 30 follower 31 driver 42 transmissive optical sensor 43 discriminating means 44 through hole 45 reflective optical sensor 46 reflective member 47 magnetic sensor 48 magnetic member 50 Gear 51 Follower gear 53 Missing part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Kubota 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Atsushi Inoue 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka Incorporated (72) Inventor Toshihide Ogoshi 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Japan Sharp Inc. (72) Inventor Toshio Nishino 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Sharp Inc.F Terms (reference) 2H077 AA20 AA37 AB04 AB07 AB13 AC04 AC16 AD06 BA02 DA10 DA15 DA35 DA36 DA52 DA63 DA64 DA72 DB01 DB10 EA01 EA11 3J103 AA02 AA74 FA07 FA18 FA19 FA30 GA02 GA52

Claims (12)

[Claims] A stirrer for stirring toner is rotatably provided in the toner tank, and one end of a rotation shaft of the stirrer extends outside the toner tank, and a driven body is integrally formed with one end of the rotation shaft. A driving body is provided outside the toner tank, the driving body being engaged with the driven body and transmitting a rotational driving force to the rotating shaft, and the driving body is detachably movable with respect to the driven body. When the driven body separates from the driving body, the stirring body rotates in response to its own weight toward the bottom dead center and stops at a position corresponding to the amount of toner. A toner replenishing device comprising: a toner detecting unit that detects a toner amount in the toner tank from a movement of the driven body. 2. The driven body is a disk having a pin protruding therefrom, and the driving body is a cam mounted on a driving shaft, and when the cam comes into contact with the pin, a rotational driving force is transmitted. The toner replenishing device according to claim 1, wherein 3. The stirrer includes a frame-shaped stirrer protruding radially from a rotation axis, a center of gravity of the stirrer being eccentric from the rotation axis, and a pin of a disc being positioned at the position of the center of gravity. 3. An arrangement according to claim 2, wherein the extension is arranged on an axial extension line.
A toner replenishing device as described in the above. 4. The driven body is a driven gear, the driving body is a driving gear meshing with the driven gear, and a part of the driving gear is formed with a toothless portion, and the toothless part faces the driven gear. 2. The toner replenishing device according to claim 1, wherein the driven member is separated from the driving member when the driving is performed. 5. The driving gear according to claim 4, wherein the number of teeth of the driving gear is set to the number of teeth for rotating the driven gear by more than a half turn.
A toner replenishing device as described in the above. 6. The stirrer includes a frame-shaped stirrer protruding in a radial direction from a rotation axis, a center of gravity of the stirrer at an eccentric position from the rotation axis, and a toothless portion of a driving gear having a toothless portion. 6. The toner replenishing device according to claim 4, wherein the toner replenishing device is disposed on an axial extension of the position of the center of gravity. 7. The toner detecting means includes a detecting sensor provided on the driven body for detecting a detected part, and a determining means for determining a toner amount based on a detection result of the detecting sensor. The toner supply device according to claim 1, 2 or 4. 8. A detection part is a through hole formed in a circular follower, a plurality of through holes are arranged at regular intervals along an outer periphery of the follower, and a detection sensor is a transmission optical sensor. The toner replenishing device according to claim 7, wherein: 9. The magnetic head according to claim 7, wherein the detected portion is made of a magnetic piece, a plurality of magnetic pieces are attached at regular intervals along the outer periphery of the circular follower, and the detection sensor is a magnetic sensor. A toner replenishing device according to the above. 10. A detection unit comprising a reflection piece, a plurality of reflection pieces attached at regular intervals along an outer periphery of a circular follower, and the detection sensor is a reflection type optical sensor. Item 8. A toner supply device according to Item 7. 11. The toner according to claim 7, wherein the determination unit determines that the larger the change in the rotation speed is, the smaller the toner amount is based on the change in the rotation speed of the driven body detected by the detection sensor. Replenishment device. 12. The apparatus according to claim 7, wherein the determining means determines that the amount of toner is smaller as the stop time is longer based on the stop time of the driven body detected by the detection sensor.
A toner replenishing device as described in the above.