JPH0415950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device, and particularly to a developing device provided with a detection means for detecting when the amount of developer in the developing chamber is running low.

Conventionally, there has been known a developing device in which a detection means is provided in a developing chamber or a developer storage chamber in order to detect the amount of developer remaining in these chambers, and in response to a detection signal, the developer is displayed or toner is replenished. There is. However, when the developer is agglomerated, the developer stagnates in the vicinity of the detection means, and the detection means tends to malfunction.

The present invention has been made in view of the above drawbacks.
A member for stirring the developer or wiping the surface of the detecting means is provided near the developer detecting means in the developing chamber, and a detection signal is not generated even after the detecting means performs at least one cycle of operation. It is an object of the present invention to provide a developing device that replenishes developer to a developing chamber when the developer does not change.

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

The embodiment shown in the drawings is a developing device using a one-component magnetic developer. As shown in FIG. 1, this developing device consists of a replenishment toner storage chamber 1 and a developing chamber 2.
A shutter 5 is provided in a communication path 3 between the two chambers 1 and 2 to cause an appropriate amount of toner 4 to be dropped and supplied to the developing chamber 2. Further, a stirring member 6 is provided in the storage chamber 1 near the communication path 3.

In the developing chamber 2, there is a gap between a toner supply sleeve 8 containing a fixed magnet roller 7 and a developing sleeve 10 containing a fixed magnet roller 9.
They are arranged side by side so that they can rotate freely in the same direction at the same speed with d ₂ in between. A blade 11 is arranged with a gap d ₁ of, for example, 1 mm to the upwardly raised sleeve 8 . This blade 11 is made of a non-magnetic material such as aluminum, and is attached to the partition plate 12 of the two chambers 1 and 2 with a set screw 13. sleeve 10
is opposed to the image forming member (photosensitive drum) 15 at the opening 14 of the developing chamber 2 with a gap _d3 of, for example, 300μ.

The sleeves 8 and 10 are made of a non-magnetic material such as stainless steel, and as shown in FIG. In this configuration, a gear 19 integrated with the shaft 8a of the sleeve 8 is interlocked via a shaft 8a. As the gear 16 rotates in the direction of the arrow, the sleeves 8 and 10 rotate in the direction of the arrow.

The toner adhering to the surface of the rotating sleeve 8 due to the magnetic force (N ₂ ') of the magnet roller 7 is regulated by the blade 11 to a uniform thickness of about 1.2 m/m. At a position facing the sleeve 10, the adhered toner on the sleeve 8 is affected by the repulsive magnetic force (S ₁ ') of the magnet roller 7, the attractive magnetic force (N ₁ ) of the magnet roller 9, and the DC power supply DC connected in series. Under the action of the electrostatic attraction force of the bias voltage applied to the sleeve 10 by the alternating current power supply AC, it is transferred onto the sleeve 10 to form a thin layer of about 50 μm.
At a position facing the photosensitive drum 15, the toner on the sleeve 10 is transferred onto the photosensitive drum by the electrostatic attraction force of the latent image formed on the photosensitive drum 15, and the latent image is transferred onto the photosensitive drum in accordance with Japanese Patent Laid-Open No. 55-18656. Developing is carried out by the jumping development method described in Publications Nos. 9 to 9.

The toner remaining on the sleeve 10 is separated from the sleeve by the repulsive magnetic force (S ₂ ) of the magnet roller 9, and moves on the inclined bottom surface of the developing chamber 2 in the direction indicated by the dotted line arrow.

When the sensor S-1 as a toner remaining amount detection means provided at the bottom of the developing chamber detects a lack of toner in the developing chamber, in response to the detection signal, the solenoid SL-2 shown in FIG. 2 is turned on, and the lever 20 axis 2
Rotate counterclockwise using 1 as the rotation center axis.
As a result, the arm 22 is rotated counterclockwise (in FIG. 1) around the rotating shaft 23 by pulling the dowel 22a engaged with the U groove 20a of the lever 20, and is attached to the rotating shaft 23. The shutter 5 is opened to supply and drop the toner 4 from the replenishment toner storage chamber 1 into the developing chamber 2. On the other hand, when the solenoid SL-2 is turned on, the bent portion 20b of the lever 20 rotates the arm 24 counterclockwise to release the arm 24 from the controller 25.

When the controller 25 becomes free in FIG. 2, a clutch (not shown) is engaged and the rotation of the gear 26 is transmitted to the shaft 6a of the stirring member 6, and the rotation of the stirring member 6 scrapes the toner into the communication path 3.

The above gear 26 is connected to the arm 2 by the controller 25.
4, it is idly rotating on the shaft 6a. As mentioned above, solenoid SL-2 is connected to shaft 6a.
It can be used for timing both the rotation of the shutter 5 and the opening/closing operation of the shutter 5.

In the above configuration, when the sensor S-1 in the developing chamber 2 detects that the toner is running low, the solenoid SL-2 turns ON in response to the detection signal from the sensor S-1, and the toner is supplied from the replenishing toner storage chamber 1. As described above, toner is replenished by dropping. Sensor S-
When it is replenished to level 1, the signal from sensor S-1 disappears and solenoid S-2 turns OFF.
Toner supply stops. At that time, if the copy button 105 is pressed and the copying machine is in copy mode, copying is started.

The reason why the developing device is divided into the replenishment toner storage chamber 1 and the developing chamber 2 as described above is that when the developing device is operated with a large amount of toner replenished in the developing chamber 2, the toner in the lower part of the developing chamber is drained from above. This is because it is easily blocked by the weight of the toner. In particular, magnetic toner has a heavy weight per unit volume and is susceptible to blocking. In addition, frictional heat is generated due to the rotation of the sleeve 8, and the gap d ₁ between the blade 11 and the sleeve 8
When the toner passes through the toner, deterioration of the toner and changes in the triboelectric characteristics are likely to occur.

Therefore, it is better to store the minimum necessary amount of toner in the developing chamber 2 and replenish the developing chamber with toner each time it is consumed to a certain extent, so that fresh toner can always be used for development, and the toner in the developing chamber may deteriorate. Or,
Even if foreign matter is mixed in, the amount of toner to be discarded is small, making it economical.

The amount of toner remaining in the replenishment toner storage chamber is determined by sensor S.
-2 detected. When the sensor S-2 detects that the toner is running low, a lamp 27 lights up on the operation panel of the copying machine shown in FIG. 3 to indicate that the toner storage chamber 1 is running out of toner. As a method for detecting the presence or absence of toner, this sensor uses, for example, a vibrator, and detects whether or not toner is on the vibrator based on a change in the vibration mode of the vibrator. Further, the presence or absence of toner in the storage chamber 1 is detected by a sensor S-2 comprising a lamp 28 and a light receiving element 29 arranged as shown in FIG.

However, toner detection is prone to malfunction, and the sensor itself is also prone to failures, disconnections, and other accidents. For example, when sensor S-1 detects that the amount of toner in developing chamber 2 is low and replenishes toner from storage chamber 1, the detection signal of sensor S-1 disappears even after a certain period of time has passed. If not, and the sensor S-2 indicates that there is toner in the storage chamber 1, the following accident may occur.

1...Failure of sensor S-1, 2...Failure of sensor S-2, 3...Toner blocks in the storage chamber and is not replenished.In particular, in the case of accident 1, a large amount of toner is sent into the developing chamber, causing solidified toner. Otherwise, toner may enter the bearing and damage the equipment, resulting in a fatal accident.

Therefore, in the present invention, the remaining amount detection sensors S-2 and S-1 in the storage chamber 1 and the developing chamber 2 and a timer circuit are used. ) does not disappear,
When the sensor S-2 indicates that there is toner, the copying operation is stopped and an abnormality is displayed.

FIG. 5 shows a sequence diagram of the developing device of the present invention. In the sequence diagram shown in the figure, when the power is turned on, sensors S-1 and S-2 detect the presence or absence of toner, and when S-2 detects that there is toner and S-1 detects that there is no toner, Solenoid SL-2 operates and starts toner replenishment. When toner replenishment begins, a 4-second timer circuit checks the presence or absence of toner every 4 seconds. In this developing device according to an embodiment of the present invention, it is set so that an appropriate amount can be replenished in about 4 seconds, but it may be shortened, long, or continuously. After 4 seconds have elapsed, if the sensor S-1 remains out of toner and the sensor S-2 is also out of toner, it is necessary to replenish toner, and the toner replenishment lamp 27 is turned on. When sensor S-2 detects that there is toner, it is strange that sensor S-1 remains out of toner even after 4 seconds have elapsed, so in this case, the copying operation is stopped and the error lamp 44 Turn on the light and turn off the power. Note that abnormal locations may be displayed on the display 41 that normally indicates the number of copies. Sensor S after 4 seconds
-1 detects that there is toner, solenoid SL
-2 is turned off and the copy operation begins. (Step) When both the sensors S-2 and S-1 detect the presence of toner, it is checked whether the copy button is pressed or not, and then the copy operation is started. After a predetermined number of copies have been made, the copying operation is stopped. (Step) When both S-2 and S-1 detect that there is no toner, the toner replenishment lamp 27 is turned on. Also S-2
When there is no toner in S-1 and there is toner in S-1, the toner replenishment lamp 27 is blinked (step).
Even if 2 detects that there is no toner, 99 is displayed in the developing chamber 2.
It is configured to contain enough developer to make more than one copy, and does not check the presence or absence of toner during the copying operation. This is because the sensor may malfunction due to vibration or the amount of toner hitting the sensor may change, and if the machine stops due to an out-of-toner signal during copying, the sequence after recovery becomes complicated, so the specified copy After counting the number of sheets, I check whether or not there is toner. In other words, in such a copying machine, even if the toner runs out during the copying operation, if the number of copies is set to 99, the presence or absence of toner in the developing chamber is detected after copying 99 copies, and if there is no toner, the solenoid SL is activated. -2 is turned ON to replenish toner, and when toner replenishment is completed after 4 seconds, copy operation is enabled, and if toner replenishment is not completed, the toner replenishment lamp or error lamp is turned on.

In the developing device according to the present invention, as shown in the sequence diagram of FIG. 5, the sensor S-1 checks the presence or absence of toner every 99 sheets at maximum, that is, after the copying operation is completed, but when there is almost no replenishment toner in the storage chamber 1. However, there is enough toner in the developing chamber 2 to make more than 99 copies, so there is no problem. If you turn on the out-of-toner lamp when 99 copies or more can be copied, if you replenish toner in the cartridge when the lamp turns on, there is no need to worry about the copier running out of toner and stopping during copying. This has the advantage of being freed from the hassle of having to remember the copy machine sequence and how many copies the operator has made.

Further, in the developing device according to the present invention, even if the sensor S-2 is out of toner, if the toner sensor S-1 in the developing chamber 2 is in the presence of toner, a copying operation is possible. At this time, if the toner replenishment lamp blinks, and when both are out of toner, the toner replenishment lamp will be on and off, etc. If the display method is completely differentiated, the operator will know that the toner is running low, and the toner supply lamp will be turned on and off as soon as possible. It is convenient for the operator because it allows replenishment. That is, in this example, due to the size and cost of the display panel, the display is shared, and the display blinks when there is toner only at sensor S-1, which is closer to the developing area, and lights up when there is no toner in both. However, for example, an additional display may be provided to indicate that the toner is low, or it may be displayed in a different color.

As mentioned above, the toner-free sensors S-1 and S-2
If a sensor is installed, toner may adhere to the sensor surface and cause blocking, or a mountain of toner may form only in front of the sensor and the sensor may report that there is no toner in other areas (see Figure 6). ), in such cases, the sensor detects that there is toner even though there is almost no toner in the container. In order to prevent this, as shown in Figure 1, the sensor S-2 is
The above malfunction can be prevented by scraping off the toner near the top surface of the sensor S-1 or wiping the surface of the sensor S-1 with a film 46 attached to an agitation shaft 45 as shown in FIG.

However, the moment the toner is scraped off, the toner disappears from the sensor surface, so the toner does not always fall from the top instantly, and the film 46 may stop while covering the surface of the sensor S-1. Conceivable. In particular, toner that has remained in the developing device for a long time has poor fluidity, so it may be detected that there is no toner when a cavity is formed. Therefore, in the present invention, the toner out display is displayed for the first time when the toner out condition continues even after the stirring rod has rotated once or more. FIG. 8 shows a sequence diagram of the out-of-toner display according to the present invention. Even if the sensor S-2 in the storage chamber detects the out-of-toner condition, the state remains in this state for a period of time To seconds for the stirring rod 6 (FIG. 1) to rotate once. If this continues, the out-of-toner display will be displayed for the first time. Naturally, if the state changes to toner present during that time, no toner is displayed. Regarding the toner out sensor S-1 in the developing chamber, as shown in FIG.
It is also possible to turn on the solenoid SL-2 and start toner replenishment after the toner remains empty even after the time period To in which the toner (in the figure) rotates more than once, and the toner is really depleted. Since the present invention is configured in this manner, malfunction of the sensor can be prevented.

In addition, in FIG. 1, the refill toner storage container 3
0 is a cylindrical inner tube 31 having an opening 31a and a cylindrical outer tube 32 having an opening 32a, which are rotatably fitted together. Since guide protrusions 33a and 33b are formed asymmetrically on the outer surface of the outer cylinder 32, when the replenishment toner storage container 30 is loaded into the replenishment toner storage chamber 1, the opening 32a always faces downward. Therefore, after loading, the replenishment toner in the middle cylinder 31 is dropped into the storage chamber 1 by rotating the middle cylinder 31 so that its opening 31a matches the opening 32a. 34 is a shaft rotatably provided at the center of the inner cylinder 31, and 35 is a toner scraping member such as a wire attached to the shaft 34.

In FIG. 2, 36 is a protruding shaft of the end face of the inner cylinder 31 passing through the end face of the outer cylinder 32, and 37 is a protruding shaft 3.
This is the engagement member provided in 6. When loading the replenishment toner storage container 30 into the storage chamber 1, insert the engaging member 37 in the direction of the U groove 38 on the side plate of the storage chamber, and after loading, open the opening 31a of the inner cylinder 31 as described above. 32a, the engaging member 37 engages with the storage chamber side plate in the direction shown by the chain line, thereby preventing the replenishment toner storage container 30 from being removed while the toner is being discharged.

In FIG. 3, 40 is a warning display section, 41 is a sheet number display section, 42 is a cassette display section, and 43 is a copy operation section.

As described above, in the present invention, when the toner detection means in the developing chamber detects that there is no developer,
Since developer replenishment is performed when there is no change in the detection signal even after the stirring or wiping member has operated for at least one cycle, malfunctions of the detection means are eliminated.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of the developing device of the present invention, FIG. 2 is a side view of the developing device showing the power transmission system, and FIG.
Figure 4 is a cross-sectional view of a part of the replenishment toner storage chamber showing means for detecting the presence or absence of toner, Figure 5 is a sequence diagram, and Figure 6 is a diagram of the detection means. Diagram 7 showing that toner has accumulated
The figure is a sectional view showing another embodiment of the present invention, and FIGS. 8 and 9 are sequence diagrams. 1 is a replenishment toner storage chamber, 2 is a developing chamber, 3 is a communication path, 4 is toner, 5 is a shutter, 6, 45 are stirring members, 7, 9 are magnet rollers, 8, 10 are sleeves, 11 are blades, 12 is a partition plate, 15 is a photosensitive drum, 46 is a film-like wiping member, S-
1.S-2 is a sensor that detects the presence or absence of toner;
represents.

Claims (1)

[Scope of Claims] 1. A developing chamber in which a developer conveying member that carries and conveys the developer and supplies it to the electrostatic latent image carrier is arranged, and the amount of developer remaining in the developing chamber is less than or greater than a specified amount. a stirring member that periodically moves to stir the developer near the sensor or wipe the developer on the sensor surface; a developer storage chamber that stores replenishing developer; and a developer storage chamber that stores replenishing developer; When the output state of the developer replenishing means for replenishing the developer and the sensor indicating that the remaining amount of developer in the developing chamber is less than the specified amount continues for a period longer than the movement cycle of the stirring member, A developing device comprising: a control means for operating a developer replenishing means to replenish developer from a developer storage chamber to a developing chamber.