JPH0766226B2 - Toner collection device for image forming apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a toner collecting device of a copying machine as an image forming apparatus, and more specifically, a collecting container for collecting and accumulating untransferred developer collected from a photosensitive drum. The present invention relates to a toner collecting device of an image forming apparatus equipped with.

2. Description of the Related Art Generally, a copying machine as an image forming apparatus is equipped with a cleaning device that removes untransferred developer remaining on a photoconductor drum after transferring it onto a copy sheet. A toner collecting device for collecting the developer removed by the device is attached. This toner collecting device is formed so as to collect the developer removed from the photosensitive drum using a discharging mechanism or the like and accumulate the developer in a collecting container.

By the way, if the copying machine continues to operate even after the collection container is full, the developer removed by the cleaning device overflows from the toner collecting device and scatters into the copying machine, polluting each part of the device and hindering the copying operation. Or, it may result in smearing the copied image. Therefore, when the collecting container provided in the toner collecting device is filled with the developer accumulated therein, the developer is detected to warn the operator and the developer in the collecting container is discarded,
Alternatively, the collection container must be replaced.

Therefore, conventionally, as shown in FIG. 1, for example, as shown in FIG.
An expandable rubber cap (see the alternate long and short dash line A) 12 having a bellows shape is attached to the upper part of 10 and a piezoelectric vibrator is provided above the recovery container 10 facing the rubber cap 12 in close proximity.
A pressure sensor 16 having 14 is provided, and a rubber cap (see the solid line B) 12 is deformed so as to project upward as the developer 18 accumulates.
The fullness of the recovery container 10 is detected from the change in the pressing force of the piezoelectric vibrator 14 that occurs when the contact with the pressure detector 16.

However, in the detection of the toner recovery amount by this pressure detection method, the filling rate of the developer 18 which is powder is apt to change, so once it is detected, if a shock is applied to the copying machine or the recovery container for some reason, the second As shown in the figure, the filling rate of the developer 18 increases and the volume decreases, so that a void 20 is formed above the rubber cap 12 by its own weight. As a result, the pressure applied to the compression oscillator 14 by the tip of the rubber cap 12 decreases or separates, and the detection state is released. Therefore, the prior art is a detection method that is sensitive to shock and lacks reliability,
As a result of the full detection being canceled, the pressure inside the recovery container becomes high, which may cause damage to the container and scattering of the developer from the minute gap. Further, in the above method, since the pressure generated in the developer in the recovery container is directly detected through the rubber cap, it is not detected only when the rubber cap is in contact with the piezoelectric vibrator, and the piezoelectric In order to obtain the detection output from the oscillator, a considerable pressure must be applied to the oscillator. However, as described above, the filling rate of the powder easily changes, and the pressure greatly changes depending on the degree of the filling rate.
This is because the pressure is small even though the recovery container is full, so that detection is not performed, and the developer overflows from the container, which is a factor that further reduces reliability.

The present invention eliminates the above-mentioned drawbacks of the prior art, improves the reliability of the fullness detection of the collection container, and reliably prevents the damage of the container and the scattering of the developer. It is an object of the present invention to provide a toner recovery device for an apparatus.

Configuration The configuration of the present invention will be described below based on an embodiment.

FIG. 3 is a schematic sectional view showing the overall construction of a copying machine as an image forming apparatus equipped with the toner collecting device according to the present invention. In the figure, a photosensitive drum 30 serving as an image bearing member formed in a cylindrical shape is provided rotatably in a clockwise direction 200. A charger 32, a developing device 34, and a transfer charger 3 are provided at positions close to the outer periphery of the photoconductor drum 30 along the rotation direction.
6. A blade cleaner 38 as a cleaning device is provided. Here is a brief description of the copy operation:
First, the surface of the photosensitive drum 30 is uniformly charged by the charger 32. Then, when the charged surface is exposed by an optical system (not shown), an electrostatic latent image corresponding to the written image of the original is formed (see R in FIG. 3). This electrostatic latent image is visualized by the supply of the developer (toner) from the developing device 34.

On the other hand, a paper feed cassette (not shown) is installed below the right side of the photoconductor drum 30, and the copier is fed out in the direction of the photoconductor drum by the rotation of the paper feed roller.
The copy paper is sent to the photoconductor drum 30 while being aligned with the visible image produced by the developing device 34 by the timing roller 40. Then, the toner image is transferred onto the copy paper by being brought into close contact with the photosensitive drum and by the function of the transfer belt telephone 36. The copied copy paper is thermally fixed by the fixing roller 42 on the left side, and finally discharged by the discharge roller 44 to an external stacker (not shown).

The untransferred developer remaining on the surface of the photosensitive drum 30 after the transfer is scraped off by the blade cleaner 38 and the toner collecting device.
It will be collected at 50. Copier parts are control parts
The copying operation is repeated under the control of 98 (see FIG. 5), and the operation unit such as a power switch for performing the operation, the paper end, the toner shortage, the number of copies, etc. are displayed. The display unit is installed on the upper surface of the machine frame (not shown).

Each time one copy operation is completed, the developer in the developing device 34 is consumed, and the untransferred developer removed from the surface of the photosensitive drum 30 after transfer is used as waste toner in the recovery container 52 of the toner recovery device 50. Accumulated in. When the collection container 52 is full, the waste toner may be scattered in the machine, which may cause an error such as a miscopy. In order to prevent this, the toner collecting device 50 is configured to be able to detect the amount of collected toner. That is, when the full amount of waste toner is detected, the copying operation is stopped and the operator is alerted.

The toner recovery device 50 will be described in detail. First, the blade cleaner.
The untransferred developer scraped off at 38 drops into the opening 54 for the entrance provided in the lower part of the collection container 52 so as to project laterally. The lower end of the opening 54 is bent obliquely upward, and the edge of the seal member 58 adhered to the bent portion 56 is brought into sliding contact with the photosensitive drum 30 to prevent the developer from leaking. The blade cleaner 38 has an opening 54
Is provided on the upper side of the horizontal upper surface portion 60 that forms the above, and is arranged in contact with the photosensitive drum 30 at a predetermined angle in a pressurized state. A transport roller 62 having a rectangular cross section is provided at a substantially central portion of the opening 54. The transport roller 62 rotates in the clockwise direction 202, and the waste toner 64 dropped to the opening 54 by the scraping action of the blade cleaner 38 is collected to the left in the collection container 52.
It is designed to be transferred inside. The transport roller 62 includes
One end of a blade 66 adhered to the upper side wall of the collection container 52 so as to partition the upper half between the inside of the collection container 52 and the opening 54 is in contact with the waste toner adhered to the conveyance roller 62.
It is designed to scrape 64 into the container. Therefore, when the transport roller 62 continues to rotate in the clockwise direction, the waste toner 64 accumulates in the collection container 52 and gradually moves upward.

A hole 68 is formed in the upper end surface of the recovery container 52, and the hole 68 is equipped with a rubber cap 70 as an actuator. The rubber cap 70 is in the form of a thin film and has a bellows portion 72 which is expandable and contractable in the peripheral portion. On the upper surface of the rubber cap 70, a plate magnet 74 formed of, for example, a sheet rubber magnet or the like is attached. The rubber cap 70 is a collection container 52.
When not much waste toner 64 is accumulated inside, it is shrinking due to its own weight including the plate magnet 74, and when the amount of accumulation increases and the collection container 52 is close to full, it overflows upward from the hole 68. Since the waste toner 64 presses the rubber cap 70, the rubber cap 70 extends and projects upward. Note that a structure in which magnet powder is dispersed in the material of the upper portion 73 of the cap 102 may be used.

A pressure detector 76 is provided above the rubber cap 70 at a position facing the rubber cap 70. Pressure detector 76
Is screwed to a support member 78 provided in the copying machine, and its relative position to the collection container 52 is fixed. As shown in the external view of FIG. 4, the pressure detector 76 has a box-shaped case 82 in which a cylindrical protrusion 80 is formed in the center, and a disc-shaped case having a detection surface at the tip of the cylindrical protrusion 80. The piezoelectric vibrator 84 is mounted, and the case 82 is equipped with a detection circuit (see FIG. 5) 86.

As shown in FIG. 7, the piezoelectric vibrator 84 is adhered to the cylindrical protrusion 80 at the peripheral edge on the back side so that it can vibrate mechanically in the thickness direction. The piezoelectric vibrator 84 is formed of a magnetic material, and an attractive force due to a magnetic force acts between the piezoelectric vibrator 84 and the plate magnet 74 mounted on the rubber cap 70.
The plate-shaped magnet 74 and the piezoelectric vibrator 84 made of a magnetic material are
It constitutes a suction biasing means, and the collection container 52 is almost full,
When the internal pressure of the waste toner 64 overflowing from the hole 68 causes the rubber cap 70 at the position of point O in FIG. 7 to extend and reach the position of point P, the rubber cap 70 is critically moved to the point Q. The piezoelectric vibrator 84 in FIG. As a result, after the rubber cap 70 is once adsorbed by the piezoelectric vibrator 84, impact is applied to the recovery container 52 to increase the powder filling rate, and even if the waste toner 64 in the rubber cap 70 is lowered, the rubber cap 70 is lowered. 70 does not separate from the piezoelectric vibrator 84 (see FIG. 8). The plate magnet 74 preferably has good adhesion to the piezoelectric vibrator 84.

The pressing force of the piezoelectric vibrator 84 changes rapidly before and after the rubber cap 70 is attracted. The pressure detector 76 is intended to detect the fullness of the toner recovery amount by detecting the change in the pressure applied to the pressure oscillator 84. A schematic structure of the detection circuit 86 incorporated in the pressure detector 76 is shown in FIG. An AC oscillator 90, a resistor 92, and a piezoelectric vibrator 84 are connected in series, and the piezoelectric vibrator 84 is driven by a voltage having a frequency close to the free resonance frequency when no pressure is applied, causing mechanical vibration. When the rubber cap 70 is attracted to the piezoelectric vibrator 84 and a pressing force is applied, the electrical properties of the pressure vibrator 84 change and the resonance frequency shifts, so that the voltage level across the piezoelectric vibrator 84 decreases.
Therefore, it becomes possible to detect the fullness of the recovery container 52 from the change in the level of the output voltage e by setting the voltage across the piezoelectric vibrator 84 as the output voltage e. For example, the magnitude P of pressure applied to the piezoelectric vibrator 84 and the relative output voltage level e'change as shown in FIG. 6, and the level at point D when there is no pressure drops to point F when the rubber cap 70 is adsorbed. At this time, the output voltage level e _ref at the intermediate point G may be used as the threshold for detection.

The voltage e at both ends of the piezoelectric vibrator 84 is the DC voltage E in the rectifier circuit 94.
After being converted to, the signal is output as a comparison signal to one input terminal of the comparator 96. The voltage E _ref corresponding to point G in FIG. 6 is input to the other input terminal of the comparator 96 as a reference signal. The comparator 96 outputs a low level signal when the amount of accumulated waste toner 64 in the collection container 52 is still small and the rubber cap 70 is not adsorbed to the piezoelectric vibrator 84 and E> E _ref , but the collection container 52 52 is almost full, rubber cap 70 is piezoelectric vibrator 84
When E <E _ref is satisfied, the high-level detection signal indicating the full amount of collected toner is output to the outside.

The detection signal output by the pressure detector 76 configured as described above is sent to the control unit 98. When this control unit 98 receives the detection signal and identifies that the collection container 52 is almost full,
Immediately, the lamp 100 for displaying the full amount of waste toner provided on the display section on the upper surface of the machine frame is turned on to display an alarm to the operator. Along with this, the copy operation may be prohibited. However, when the control unit 98 receives a detection signal indicating that the waste toner is full during the copy operation, it prohibits the copy operation after the copy of the copy paper is completed. When the toner full lamp 100 lights up, the operator
From the copier, discard the full waste toner 64, or replace it with a new collection container 52 to empty the collection container.
When 52 is installed, the detection signal output of the pressure detector 72 is stopped, and the control unit 98 is urged by this to release the prohibition of the copy operation.

In the above embodiment, while the magnet is attached to the rubber cap, the piezoelectric vibrator itself is made to be a magnetic body so that the rubber cap is critically biased toward the pressure detector to be attracted to the piezoelectric vibrator. However, the piezoelectric vibrator is made of a non-magnetic material, and a magnetic force is exerted between a fixed magnetic member provided for measuring the back surface of the piezoelectric vibrator and the magnet of the rubber cap so that the rubber cap presses the piezoelectric vibrator. Alternatively, as shown in FIG. 9, a magnetic plate 104 that is magnetized or not magnetized is fixed to the tip of the rubber cap 102, and on the back side of the piezoelectric vibrator 108 made of a non-magnetic material of the pressure detector 106. When the rubber cap 102 is equipped with the magnet 110 and reaches the point P when the rubber cap 102 is extended, the rubber cap 102 collides with the piezoelectric vibrator 108 by magnetic force due to the powder pressure that acts between the magnetic plate 104 and the magnet 110 critically. Alternatively, it may be in a pressed state. As shown in FIG. 9, pressure detector
When a fixed magnet is provided on the 106 side, the magnetic plate 104 may not be provided when using the magnetic powder developer.

Effect According to the present invention, as described above, the deformable member formed by receiving the powder pressure of the waste toner is provided in the recovery container, and the toner recovery amount detector for detecting the deformation of the variable member is provided outside the recovery container. When the deformable member is deformed by a predetermined amount, the deformable member is equipped with a pressing urging means for urging the deformable member toward the detector so as to detect the fullness of the waste toner. As a result, the deformable member is deformed according to the amount of waste toner accumulated in the collection container,
When it is full or close to it, it is urged toward the detector by an external force to operate the detector. Therefore,
Even if the pressing force received from the waste toner in the collection container is small, the detector will operate if it becomes almost full and a predetermined amount of deformation occurs.Therefore, as with a non-contact type toner collection amount detection device such as an optical sensor type, low powder pressure is applied. Therefore, the detection operation can be reliably performed, and the waste toner does not overflow from the collection container. In addition, even if full pressure is detected while the pressure inside the recovery container is relatively low, and once detected, even if the position of the waste toner in the container is lowered due to impact or the like, the detection state continues and the filling rate increases. An abnormal pressure is not generated in the recovery container, and therefore the container is not damaged and the waste toner does not leak from the minute gap, so that a highly reliable toner recovery device can be obtained.

[Brief description of drawings]

1 and 2 are sectional views with a part omitted for explaining the operation of a conventional toner collecting device, and FIG. 3 is an overall view of an embodiment of a copying machine equipped with the toner collecting device according to the present invention. FIG. 4 is a schematic sectional view showing the structure, FIG. 4 is an external perspective view showing the pressure detector in FIG. 3, FIG. 5 is a block diagram showing an example of the electrical structure of the pressure detector shown in FIG. 4, and FIG. 5 is a diagram showing the relationship between the external pressure applied to the piezoelectric vibrator and the relative output level in FIG. 5, and FIGS. 7 and 8 are cross-sectional views with a part omitted for explaining the toner recovery amount detection operation. FIG. 9 is a partially omitted sectional view showing another embodiment of the toner collecting device. Explanation of symbols for main parts 10,52… Recovery container 12,70,102… Rubber cap 14,84,108… Piezoelectric vibrator 16,76,106… Pressure detector 18,64… Waste toner 74… Plate magnet 104… Magnetic plate 110… Magnet

Claims (2)

[Claims] 1. A toner collecting device for an image forming apparatus, wherein the untransferred developer collected from an image carrier is stored in a collecting container, wherein the collecting container holds a pressing force by the untransferred developer stored therein. The toner recovery device includes a deformable member that receives and deforms outward of the recovery container, the toner recovery device is disposed outside the recovery container, and a detector that responds to the deformation of the deformable member; A magnet provided on one of the member and the detector, and a magnetic member provided on the other of the deformable member and the detector and facing the magnet, wherein the deformable member is provided. A suction biasing unit that biases the deformable member toward the detector when it is deformed by a certain amount, and a predetermined amount of the developer accumulated in the recovery container in response to the output signal of the detector. Outputs the indicated display signal And a circuit for holding the detection state of the deformable member by the suction urging means. 2. A toner recovery device for an image forming apparatus, wherein the untransferred developer of magnetic powder recovered from an image carrier is stored in a recovery container, wherein the recovery container has the untransferred developer stored therein. A deformable member that is deformed toward the outside of the recovery container when the deformable member is deformed toward the outside of the recovery container. A suction urging means that is provided in the detector and that is formed of a magnet that faces the deformable member, and that urges the deformable member toward the detector when the deformable member is deformed by a predetermined amount, A circuit that responds to the output signal of the detector and outputs a display signal indicating that a predetermined amount of developer has accumulated in the recovery container, and detects the detection state of the deformable member by the suction urging means. Characterized by holding Toner collection device for image forming apparatus.