JPH11231634A - Toner detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always accurately, easily and stably detect the existence of toner in a toner carrying path by means of an emptiness detecting sensor by providing the emptiness detecting sensor in a state where its detecting surface is exposed to the internal base of the toner carrying path. SOLUTION: The toner T fed from a toner cartridge 10 is temporarily stored in a reserve tank 2 and fed to a developing device by a required amount when it is required. The tank 2 is provided with the emptiness detecting sensor 5 at a bottom part corresponding to a position near to a center part from the toner introducing port of a toner storing and carrying path. The sensor 5 is a piezoelectric sensor which detects the existence of the toner T according to whether or not the toner T being carried comes in contact with the detecting surface 50 at a specified rate, and is attached in a state where the surface 50 is horizontally exposed to the internal base 20a of the carrying path. A spiral agitator 26 is set to rotate in a state where it approaches to the surface 50 to such an extent that it nearly comes in contact therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the presence or absence of toner in a conveying path when toner used for developing a latent image is conveyed through a toner conveying path by a rotating toner conveying member. More particularly, the present invention relates to a toner detecting device applied to a toner supply device for supplying toner to a developing unit in an image forming apparatus such as a copying machine or a printer using an electrophotographic method. .

[0002]

2. Description of the Related Art A toner detecting device of this type is used, for example, in a toner supply device in an image forming apparatus utilizing an electrophotographic system. FIGS. 6 and 7 show a toner supply device that supplies the toner T from the toner container 100 to the developing device 102 through the toner conveyance path 101 in the image forming apparatus.

That is, in the illustrated toner supply device, the toner T contained in a toner container 100 is moved by a toner conveying member 103 formed of a spirally wound linear member rotating in the container 100. After the toner is conveyed in the direction a and sent out from the toner discharge port 100a to the toner conveying path 101, the toner conveying member 104 is formed of a spirally wound linear member or the like that rotates in the direction of arrow c in the toner conveying path 101. To transport in the direction of arrow b,
The toner is sent from the toner outlet 101a to the side of the second toner conveyance path 105 connected to the developing device 102, so that the toner is sent to the developing device 102 as a supply destination. In FIG. 6, reference numeral 106 denotes the toner conveying members 103 and 104.
2 shows a gear mechanism for transmitting rotational power to the motor.

[0004] In such a toner supply device,
Normally, as a toner detecting device for detecting the presence or absence of toner in the toner conveying path 101, a detection surface 10 capable of detecting the presence or absence of toner by detecting whether or not a predetermined amount of toner is touched.
An empty detection sensor 107 having 7a is provided. In fact, the empty detection sensor 107 is provided on a side wall portion having a predetermined height from the inner bottom surface of the toner conveying path 101 and has a detection surface 107
a is exposed so as to be exposed to the inside of the transport path in a state vertical or slightly inclined with respect to the horizontal plane (Japanese Utility Model Laid-Open No. 4-88862, Japanese Patent Laid-Open No. 8-106210, etc.).

When the toner T in the toner conveying path 101 is sufficient, the empty detection sensor 107 detects that toner T
Is fully and sufficiently touching the detection surface 107a, so that “toner is present” is detected. Conversely, when the toner T in the toner conveyance path 101 decreases, the toner T that touches the detection surface 107a is detected. Since the amount of toner is small, "no toner (empty)" is detected. The image forming apparatus is provided with a function of displaying a warning to prompt the user to replenish the toner in the toner container 100 or to replace the toner when the absence of toner is detected.

[0006]

By the way, in a toner conveying apparatus provided with such a toner detecting device (empty detecting sensor 107), generally, the conveying state of the toner T, the shape of the toner conveying path 101, the empty detecting state, and the like. The contact state (pressing state) of the toner T on the detection surface 107a of the empty detection sensor 107 may greatly fluctuate due to a difference in the mounting position of the sensor 107 and the like.
Even though there is a sufficient amount of toner T inside, the contact state of the toner is temporarily weakened and
There is a problem that erroneous detection that is detected is generated.

Such an erroneous detection is caused by, for example, the toner T being temporarily biased to one side of the toner conveying path 101 due to the rotation of the toner conveying member 104 as shown in FIG. 7 (shown by a dotted line in the figure). State), the detection surface 107
This is often caused by a state in which it hardly exists near a.

As a countermeasure against the occurrence of such erroneous detection, a warning display such as toner replenishment or the like as described above is not immediately performed even when the detection signal of "no toner" is issued from the empty detection sensor 107. for example, as shown in FIG. 8a, the or perform first warning display when the number of occurrences of the detection signal of "toner Mu" satisfies a preset reference number N _X, or, as shown in FIG b , there is a method to perform the first warning at that time the generation duration detection signal of "toner Mu 'satisfies a predetermined reference time T _X.

However, in this case, as shown in FIG. 9, a driver (driving unit) 11 for driving an empty detection sensor 107 and a display device 110 for displaying a warning such as toner supply.
Counting whether or not the number of occurrences of the “toner absence” detection signal from the empty detection sensor 107 exceeds the reference number N _X , or the occurrence time exceeds the reference elapsed time T _X. It is necessary to provide the control unit 112 that performs control processing for counting whether or not the signal is transmitted to the driver 111 and transmitting a drive signal to the driver 111 (that is, processing for confirming the authenticity of the detection signal before performing display). , Resulting in increased costs. In addition, when the state of the erroneous detection described above is prolonged, the erroneous detection state may remain unchanged even after the control processing by the control unit 112,
Therefore, there is a problem in terms of detection accuracy.

Further, in the toner conveying device provided with the above-mentioned empty detection sensor 107, the toner T may adhere or stay on the detection surface 107a of the toner conveyance device. Therefore, it is necessary to provide a cleaning member 108 for always cleaning the detection surface 107a. The cleaning member 108 is attached in a state in which a wire such as a wire is upright on the rotating shaft 104a of the toner conveying member 104, and is attached such that the tip of the wire comes into contact with the detection surface 107a when rotating. What is rotated with the conveyance member 104 is often used. However, such a cleaning member 108 is unexpectedly cumbersome to install,
There was a problem that it was difficult to stabilize the cleaning performance.

The present invention has been made in view of the above-mentioned problems of the prior art, and its main objects are as follows.
An object of the present invention is to provide a toner detecting device capable of always and accurately detecting the presence / absence of toner in a toner conveying path provided with a rotating toner conveying member by an empty detection sensor stably. Another object is to eliminate the need for a cleaning member for cleaning the detection surface of the sky detection sensor.

[0012]

According to a first aspect of the present invention, there is provided a toner detecting device which is capable of achieving the above object. A device that detects the presence or absence of toner in the above based on the amount of toner that comes into contact with the detection surface of the empty detection sensor, wherein the empty detection sensor is provided with the detection surface exposed on the inner bottom surface of the toner conveyance path. It is what is being done.

According to such an apparatus, since the detection surface of the empty detection sensor is exposed at the inner bottom surface of the toner conveyance path provided with the rotating toner conveyance member, the toner is likely to be present at a lower position due to its own weight. Is accurately detected with a very high probability. Further, in the toner conveying path having the rotating toner conveying member, the toner is loosened by the rotating toner conveying member, and the toner is unevenly distributed so as not to exist only on the inner bottom surface of the conveying path. Since it cannot occur, the toner is reliably detected while the toner is present in the transport path to some extent.

According to a second aspect of the present invention, in the toner detecting device, the toner conveying member is provided so as to rotate while approaching the detection surface of the empty detection sensor.

In the case where the toner conveying member is provided in this manner, the detection surface of the empty detection sensor and the vicinity thereof do not always cause toner adhesion, stagnation, and lump due to rotation of the toner conveying member. As a result, the detection surface is maintained in a state in which good detection performance is obtained, so that there is no need to provide a cleaning member for cleaning the detection surface.

[0016]

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

FIGS. 1 to 3 show an example of a toner supply device to which the toner detection device of the present invention is applied. FIG. 1 is a schematic sectional view thereof, and FIG. 2 is a view taken along line AA of FIG. FIG. 3 is a cross-sectional view of a main part along a line BB in FIG. 1.

This toner supply device supplies new toner contained in a toner cartridge to a developing device in an image forming apparatus such as an electrophotographic copying machine or a printer. Basically, a cartridge mounting portion 1 for detachably mounting a toner cartridge 10 containing a toner T, and a toner cartridge 1
Reserve tank 2 for temporarily storing the toner T sent out from the developing unit 90 and sending out the necessary amount to the developing device 90 when necessary.
And a driving device 4 serving as a driving source of a rotating member in the toner cartridge 10 and the reserve tank 2.

First, as shown in FIGS. 1 and 2, the toner cartridge 10 has a cartridge main body 11 formed in a cylindrical shape, and a lid attached to both ends of the cartridge main body 11 to seal the inside of the main body 11. Body 12,13
A spiral agitator 14 as a toner conveying member formed by spirally winding a metal wire having elasticity at least close to the inner peripheral surface of the cartridge body 11, and rotating around the center of one lid 12. The coupling 15 is freely mounted, and comprises a coupling 15 which rotatably supports the spiral agitator 14 in the cartridge body 11 and is coupled to a connection portion of the drive transmission shaft of the drive device 4. Also, on one end side of the cartridge body 11,
A toner discharge port 17 for discharging toner to the reserve tank 2 and opening a shutter (not shown) when the shutter is mounted is opened.

As shown in FIG. 2, the cartridge mounting portion 1 has a cylindrical main body 11 of the toner cartridge 10.
And a support frame having a shape capable of supporting and fixing when mounted. The cartridge 1 in the mounting section 1
At a position corresponding to the toner discharge port 17 of 0, a toner passage port 1a is opened.

As shown in FIG. 2 and FIG. 3, the reserve tank 2 contains toner T supplied from the toner cartridge 10.
Are temporarily stored and transported so as to circulate, and are disposed between the toner storage transport paths 20 and 21, and the toner T is connected to the developing device 90. And a toner supply unit 31 that supplies the toner to the second toner transport path 30. A partition wall 22 is formed between the toner containing transport paths 20 and 21 and the toner supply unit 31. On the other hand, communication paths 23 and 24 are formed in areas not partitioned by the partition wall 22 so that the toner storage transport paths 20 and 21 and the toner supply unit 31 communicate with each other. Further, a toner introduction port 25 (see FIG. 3) through which the toner T sent out of the toner cartridge 10 is introduced opposite to the toner discharge port 17 of the toner cartridge 10 is provided above the toner storage conveyance path 20 facing the communication path 24. Is indicated by a two-dot chain line).

Spiral agitators 26 and 27 serving as a toner conveying member in which a metal wire having elasticity is spirally wound are arranged in the toner accommodating conveying paths 20 and 21 in parallel with each other. One end of each of the agitators 26 and 27 is attached to couplings 28 and 29 connected to a connection portion of the drive transmission shaft of the driving device 4, and the other end is rotatably supported. The spiral agitators 26 and 27 rotate in the same direction d, but their winding directions and the like are set such that the toner conveyance directions are opposite to the directions of arrows e and f in the figure.

A toner supply port 32 for supplying toner from the reserve tank 2 to the toner relay conveyance path 30 is opened at a predetermined position on the bottom of the toner supply section 31. A dispense auger 3 for feeding toner to the toner supply port 32 is provided between the toner supply section 31 and the communication path 23.
3 is arranged in parallel with the two spiral agitators 26 and 27 described above. The rotating shaft 33a of the dispense auger 33 is supported so as to protrude outside the tank so as to be connected to the driving shaft (40) of the driving device 4. A paddle 34 having two blades radially protruding from the rotation shaft is attached to a portion of the rotation shaft 33a corresponding to the communication passage 24. Further, an auger 39 that is rotationally driven so as to convey the toner is provided inside the second toner conveying path 30.

The drive unit 4 has a drive shaft 40 for rotating the dispense auger 33 of the reserve tank 2, and the drive shaft 40 is driven to rotate by an electric motor (not shown). And the drive shaft 40
The rotational power of the spiral agitators 26, 2 of the toner storage transport paths 20, 21 is transmitted by a predetermined gear transmission mechanism 41.
7 (couplings 28 and 29) and the spiral agitator 14 of the toner cartridge 10 (coupling 1)
5) are transmitted through the respective couplings.

As shown in FIG. 1 to FIG. 3, the reserve tank 2 in the toner supply device has a toner detecting portion at a bottom portion which is closer to the center than the toner introduction port 25 of the toner accommodating and conveying path 20. An empty detection sensor 5, which forms part of the device, is provided.

That is, the empty detection sensor 5 is a piezoelectric sensor for detecting the presence or absence of toner by detecting whether or not the toner being conveyed contacts the detection surface 50 at a predetermined ratio. 50 is the inner bottom surface 20a of the transport path 20
It is mounted horizontally exposed. The spiral agitator 26 is set so as to rotate in a state in which the spiral agitator 26 is close to the detection surface 50 just before the contact.

As shown in FIG. 4, a detection signal obtained from the detection surface 50 of the empty detection sensor 5 is a driver for driving a display device 6 for displaying a warning such as toner supply. (Drive unit) 60 so as to be directly input. Then, the driver 60 is set so as to immediately display a warning necessary for toner supply on the display device 6 when “empty toner (empty)” is detected by the empty detection sensor 5 (FIG. 5).

In this toner supply device,
The driving device 4 is driven according to a predetermined control signal transmitted from a control unit of the image forming apparatus main body, and the toner T in the toner cartridge 10 is developed via the reserve tank 2 and the second toner conveying unit 30 by the developing device. 90 is set to be executed. Also,

Next, the operation of the toner supply device equipped with such a toner detection device will be described.

First, the driving device 4 is driven by input of a control signal, and the spiral agitator 14 of the toner cartridge 10 and the spiral agitator 2 of the reserve tank 2 are driven.
When the toner cartridges 6 and 27 rotate, the toner cartridge 1
The toner T in the cartridge main body 11 is rotated by a spiral agitator 14 rotating in the cartridge main body 11 so that the toner T is discharged from the toner outlet 17.
And is sent out toward the reserve tank 2 through the outlet 17 (FIGS. 1 and 2). Next, the toner T sent out from the toner cartridge 10 is
After being accommodated in the toner accommodating conveyance path 20 through the toner introduction port 25 of the reserve tank 2, the toner is conveyed in the arrow e direction by a spiral agitator 26 rotating in the d direction in the conveyance path 20 (FIGS. 2 and 3).

The toner T transported to the end of the toner storage transport path 20 in the transport direction e is sent to the communication path 23, and a part of the toner T is transferred to the toner storage transport path 21 by the dispense auger 33. And the remaining part is sent to the toner container 31 side.

The toner T sent to the toner accommodating / conveying path 21 is conveyed in a direction indicated by an arrow f by a spiral agitator 27 rotating in a direction d in the accommodating section 21 and continuously connected at the end of the conveying direction f. After being sent to the passage 24 side, the dispense auger 3
The paddle 34 is rotated by the pad 3 and is again fed into the toner containing conveyance path 20 and returned. Therefore, a part of the toner T sent to the reserve tank 2 is circulated in a circulation path including the toner storage transport path 20, the communication path 23, the toner storage transport path 21, and the communication path 24.

On the other hand, the toner T sent to the toner supply unit 31 is sent to the toner supply port 32 by the dispense auger 33 which rotates for a predetermined time when toner supply to the developing unit 90 is required. Is supplied to the second toner transport unit 30 from the supply port 32. Then, the toner T sent from the reserve tank 2 to the toner transport unit 30
Is sent to the developing device 90 as a supply destination by the auger 39 rotating in the transport path 30.

In this toner supply device,
While a sufficient amount of toner T is present in the toner storing and conveying path 20, the toner T is conveyed by the rotating agitator 26 while the toner T is exposed on the detection surface 50 of the empty detection sensor 5 exposed on the bottom surface of the conveying path 20. Because of the touch, the toner detecting device detects “toner present”.

At this time, even if the toner T is unevenly distributed in the transport path 20 as described in the prior art (see FIG. 7), the toner
Since it is present on the a side, erroneous detection of the empty detection sensor 5 does not occur due to the contact (pressing) state of the toner T on the detection surface 50 temporarily fluctuating in a weaker direction.

Since the rotating spiral agitator 26 always passes above the detection surface 50, the toner T on the detection surface 50 is loosened by the agitator 26 so as to be agitated and moved in the transport direction e. It is being sent. Thereby, the toner T
Is always in a flowing state, so that it does not adhere to the detection surface 50 and stick. Therefore, the detection surface 50 of the sensor 5 is in a state where it is being cleaned by the agitator 26 which rotates so as to pass in the vicinity thereof, and is always kept in a state where good detection can be performed. Therefore, there is no need to provide a cleaning member (reference numeral 108 in FIGS. 7 and 8) such as a conventional device for cleaning the detection surface 50 of the sensor 5.

When the toner supply operation as described above is repeated and the toner T in the toner cartridge 10 is no longer consumed, the toner T sent from the cartridge 10 to the toner accommodating conveyance path 20 of the reserve tank 2 is also eliminated.

Then, the toner T in the toner conveying path 20 is conveyed by the spiral agitator 26 to the downstream side in the conveying direction e.
It hardly exists even above. As a result, the contact state of the toner T touching the detection surface 50 of the empty detection sensor 5 is extremely weakened, so that the toner detection device detects “no toner”. When the empty detection sensor 5 detects "no toner", it is assumed that there is no toner T in the toner transport path 20 as well as in the toner cartridge 10, and FIG. As shown in (1), a warning display prompting toner supply or the like is displayed on the display device 6 immediately.

In this toner detecting device, the empty detecting sensor 5
When it is detected that "no toner", the display device 6 can be operated immediately to display a necessary warning (see FIG. 5). There is no need to provide a control unit (reference numeral 112 in FIG. 9) such as a conventional device for performing control processing for verifying authenticity (see FIG. 4). In addition, the sky detection sensor 5
Is detected as "no toner", it is certain that the toner T in the transport path 20 has run out unless there is a failure in the sensor. Therefore, there is no problem even if the display device 6 is operated immediately. Therefore, extremely accurate detection can be performed.

In the above-described embodiment, the empty detection sensor 5 is connected to the toner introduction port 25 of the toner containing conveyance path 20.
Although it is provided at the bottom closer to the center than at the center, it may be provided at the bottom just below the toner inlet 25 so that the detection surface 50 is exposed. In this case, since the state of the toner T sent from the toner cartridge 10 to the reserve tank 2 is directly detected, more accurate toner detection can be performed reliably and stably.

In the above-described embodiment, the toner detecting device (empty detection sensor 5, etc.)
Although the example in which the present invention is applied to the toner supply device that supplies the toner from 0 to the developing device 90 has been described, the present invention is also applied to a developing device main body or a toner container in which a rotating toner conveying member is disposed to determine whether toner is present. It may be used to detect.

Further, in the above-described embodiment, an example is shown in which the cleaning member for the empty detection sensor 5 is not provided. However, a known cleaning member may be provided if necessary. In the case where such a cleaning member is provided, although there are difficulties such as an increase in cost, the detection performance of the empty detection sensor 5 provided with the detection surface exposed on the inner bottom surface of the transport path is more stable and reliable. There are also advantages.

[0043]

As described above, according to the present invention,
Since the empty detection sensor is provided so that its detection surface is exposed at the inner bottom surface of the toner transport path, the presence / absence of toner in the toner transport path provided with the rotating toner transport member is determined by the toner transport. Irrespective of the state, the shape of the toner conveyance path, and the like, the detection can be always performed accurately, easily and stably. As a result, it is possible to reliably prevent the occurrence of an erroneous detection that detects the absence of toner despite the presence of toner, as in the related art. Also, the detection signal of no toner (sky) obtained by the sky detection sensor has high accuracy,
Therefore, there is no need to perform control processing for confirming the authenticity of the detection signal as in the related art.

In the case where the toner conveying member is provided so as to rotate while approaching the detection surface of the empty detection sensor,
There is no need to provide a cleaning member for cleaning the detection surface.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a toner supply device to which a toner detection device according to the present invention is applied.

FIG. 2 is a cross-sectional view of a main part along line AA in FIG.

FIG. 3 is a cross-sectional view of a main part along line BB in FIG. 1;

FIG. 4 is a block diagram illustrating a configuration example of a toner detection device when used in combination with a display device.

FIG. 5 is a timing chart showing a relationship between a toner detection signal and a display operation.

FIG. 6 is a conceptual diagram illustrating a toner supply device provided with a conventional toner detection device.

FIG. 7 is a cross-sectional view illustrating an attached state of the toner detection device of FIG. 6;

FIG. 8 is a timing chart showing a relationship between a conventional representative toner detection signal and a display operation.

FIG. 9 is a block diagram illustrating a configuration example of a toner detection device when used in combination with a conventional display device.

[Explanation of symbols]

5: Empty detection sensor, 20: Toner storage conveyance path (toner conveyance path), 20a: Internal bottom surface, 26: Spiral agitator (toner conveyance member), 50: Detection surface, T: Toner.

Claims (2)

[Claims] 1. An apparatus for detecting presence / absence of toner in a toner conveyance path provided with a toner conveyance member that rotates and conveys toner based on an amount of toner contacting a detection surface of an empty detection sensor, A toner detection device, wherein an empty detection sensor is provided with its detection surface exposed at the inner bottom surface of the toner transport path. 2. The toner detecting device according to claim 1, wherein the toner conveying member is provided so as to rotate while approaching a detection surface of an empty detection sensor.