JP3657112B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a toner recycling mechanism used in an electrophotographic image forming apparatus such as a printer, a facsimile machine, or a copying machine, and more particularly to a cleaning device in an image forming apparatus using a two-component developer or a one-component developer. The present invention relates to a toner recycling mechanism that collects, transports, and reuses toner removed by the above.
[0002]
[Prior art]
In image forming apparatuses such as electrophotographic printers, facsimiles, and copiers using two-component developers or one-component developers, the toner removed by the cleaning device from the object to which the toner adheres is collected / removed. In many cases, a toner recycling mechanism that is transported and reused or discarded is employed.
As a technique related to a collected toner transfer device for transferring toner from a cleaning device to a collected toner storage unit or a developing device provided separately from the cleaning device, there are the following techniques.
(1) The recovered toner discharge portion of the cleaning device and the recovered toner storage means provided separately from the cleaning device are connected by a pipe, and the recovered toner is recovered by a coil screw provided inside the pipe. Technology to transfer to.
(2) A technique in which a collected toner storage means is provided in the vicinity of the collected toner discharge portion of the cleaning device, and the toner is transferred to the collected toner storage means mainly by gravity.
Furthermore, there are the following techniques related to powder transfer of developer, toner, and the like.
(1) Using a screw, paddle (various shapes), a bucket, etc. as a toner transfer technique in the developing unit and toner supply unit of the developing device.
(2) A screw pump (commonly known as a MONO pump) is used as a pump capable of transferring powder without using a coil screw.
[0003]
[Problems to be solved by the invention]
As described above, in a conventional recovery toner transfer device that recovers and transports foreign matter such as toner and paper dust removed by a cleaning device from an object on which toner such as a photosensitive member and an intermediate transfer member is likely to adhere and remain, As the transfer means, the recovered toner is collected by a pipe connecting the recovered toner discharge portion of the cleaning device and the recovered toner storage means or developing device provided separately from the cleaning device, and a coil screw provided inside the pipe. Or a method of carrying out the transfer by natural fall using the gravity of the collected toner.
Of these recovery and transfer means, the former one needs to extend the coil screw to the vicinity of the recovered toner storage means or the developing device. However, in the transfer means using a coil screw, it is necessary to secure a transfer path which is preferably a linear transfer or a large curve transfer in order to ensure reliable rotation of the coil screw. Setting was impossible. In other words, there is a limit to the degree of freedom of layout, which has become a factor that makes device design difficult. In addition, there is a layout restriction that the installation position of the collected toner storage means is desirably lower than the horizontal direction with respect to the collected toner discharge portion. Furthermore, since the friction load between the coil screw and the pipe is very large and the load of the rotational drive torque is large, there is a problem that long distance transfer becomes difficult, the configuration becomes large, and the device configuration becomes complicated. It was difficult to ensure durability and had various problems that operability during device maintenance was difficult. In addition, due to the restriction of the mounting position of the collected toner transfer device, there are problems that the main body of the image forming apparatus is enlarged, complicated, and the cost of the main body increases. Furthermore, since it is necessary to arrange the toner storage means or the developing device almost integrally with the cleaning device, the models that can be installed are low speed machines or use copy / print due to restrictions on the installation of the device and restrictions on the toner storage amount. Limited to copiers / printers for low-volume users. The above problem has been a problem to be solved for many years, but has not been solved until recently.
On the other hand, a toner collection / transfer device using a powder transfer screw pump (commonly known as a MONO pump) eliminates the disadvantages of the conventional device using the coil screw, and optimizes the size of the developing device and the device main body. In addition, it has attracted attention as a recovered toner transfer device that has solved the conventional problems in recovered toner transfer while satisfying quality, performance, and function as a cleaning device.
However, since the stator of the screw pump is made of rubber, the sliding surface where the stator comes into contact with the rotor is likely to wear or creep when used over time. As a result, the amount of biting and adhesion between the rotor and the stator are likely to occur. There is a problem that the transfer force (discharge pressure) of the pump is reduced and the stator is handled as a replacement part, and the service cost is high.
[0004]
  The present invention has been made in order to solve the above-described problems, and is a recovery toner transfer that solves the conventional problems while optimizing the size of the apparatus main body and satisfying the quality, performance, and function as a cleaning apparatus. An object is to provide an apparatus. In detail, the time-dependent wear of the stator, which is a problem when the toner mixed with the screw pump and the air pump is used to transfer the mixed gas to the inside of the elastic tube, and the discharge pressure of the pump due to this is reduced. To prevent.
  That is, the invention of claim 1When transfer paper is jammed, the drive timing of the screw pump and the air supply means is corrected, and the interval of toner transfer operations by the screw pump and the air supply means is shortened. It is possible to improve the accuracy of the amount determination, simplify the configuration of the toner recovery device, reduce the cost, and prevent the toner in the screw pump unit from overflowing or crosslinking due to a temporary increase in the toner recovery amount.
[0005]
[Means for Solving the Problems]
  In order to achieve the above object, the invention of claim 1 is directed to a toner recovered by an image carrier cleaning device or a transfer paper transport member cleaning device.TimesToner collecting means or means for transferring to developing device, female screw type stator having spiral groove inside,as well asAn externally threaded row that is rotatably inserted into the stator.TA screw pump, an air supply means for fluidizing the collected toner that is transferred by the screw pump and moving in the collected toner transfer pipe in a diffused state, and the screw pump is independent of the image carrier. Drive means or drive transmission means that can be driven and stopped, and a control device that outputs a drive signal to the drive means.In the image forming apparatus, the control device corrects the drive timing of the screw pump and the air supply unit when a paper jam occurs in the transfer paper conveyed through the image forming apparatus, and the screw pump And the interval of the toner transfer operation by the air supply means is shortened.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
FIG. 1 is an overall configuration diagram of a copying machine as an example of an image forming apparatus to which the present invention is applied. A copying machine 100 performs predetermined image formation by a conventionally known electrophotographic method. And an automatic document feeder 102. In the copying machine main body 101, a reading optical system 103, an image forming unit 104, a paper feeding unit 105, a toner recycling mechanism, and the like are arranged.
The image forming unit 104 includes a photosensitive drum (image carrier) 120, a charging unit 121, an exposure unit 122, a developing device 300, a transfer device 700, a fixing device 124, a cleaning device 200, and the like.
As the cleaning device 200, an example using a blade cleaning method is shown.
Further, the recovered toner transfer pipe 400 constituting the toner recycling mechanism includes a cleaning device 200, a transfer device 700, a developing device 300 (or recovered toner storage unit 600), and a recovered toner transfer device (powder pump unit) 500. The residual toner (collected toner) collected from the photoconductor 120 by the cleaning device 200 is transferred toward the developing device 300 or the collected toner storage unit 600.
Here, the collected toner storage means 600 is configured as an independent unit that can be attached to and detached from the copying machine main body 101.
The toner recycling mechanism of the present embodiment includes a collected toner transfer pipe 400, a collected toner transfer device 500, a collected toner storage means 600, and the like.
[0007]
2 is an enlarged view of the periphery of the photoconductor 120 of FIG. 1, and FIG. 3 is a rear view of FIG. The photosensitive member (image bearing member) 120 is cleaned by scraping off residual toner by a cleaning blade 240 and a brush 241.
The residual toner scraped off from the surface of the photoconductor 120 is collected as a collected toner in a housing 242 that serves as a structure of the cleaning device 200 and a toner guide member, and is disposed at the bottom of the housing 242. The recovered toner discharge member 220 transfers the toner to a hopper 510 that is a part of the recovered toner transfer device 500.
The transfer device 700 uses the transfer belt 710 to transport and transfer the transfer paper, and is in contact with the photoconductor via the transfer paper at least during the passage of the transfer paper. For this reason, toner on the photosensitive member may adhere to the transfer belt 710, and the cleaning blade 711 for cleaning the toner and the collected toner scraped off by the cleaning blade 711 are discharged to the outside of the transfer device. A collected toner discharge member 720 is provided.
The configuration of the developing device 300 used in the copying machine main body 101 shown in FIG. 1 is shown in FIG. A developing device 300 shown in FIG. 2 uses a two-component developer in which a toner and a carrier are mixed, and includes a developing unit 301 and a toner replenishing unit 302. The developing unit 301 includes a stirring member including a stirring roller 303 and a paddle wheel 304 and a developer carrying member including a plurality of developing rollers 305 and 306. The stirring roller 303 and the paddle wheel 304 are rotationally driven by a driving unit (not shown). Then, the two-component developer in the developing unit 301 is stirred and conveyed. In the two-component developer composed of the toner and the carrier, the toner and the carrier are charged with opposite polarities due to stirring by the stirring roller 303 and the paddle wheel 304.
[0008]
The developing rollers 305 and 306 are mainly composed of a fixed magnet roller and a sleeve that is provided in the periphery thereof and is driven to rotate by a driving unit (not shown). Along the upstream side and the downstream side.
In the developing unit 301, the developing roller 306 holds the developer conveyed by the paddle wheel 304 by magnetically attracting it with a magnet, and conveys the developer to the developing roller 305 by rotation of the sleeve. The developing roller 305 holds the developer from the developing roller 306 and the paddle wheel 304 by magnetically attracting them with a magnet, and conveys the developer as the sleeve of the developing roller 306 rotates.
The developer on the developing roller 306 further develops the electrostatic latent image on the photosensitive drum 120 developed by the developing roller 305 when passing through the developing region D2 between the developing roller 306 and the photosensitive drum 120. Then, it falls into the developing unit 301 and is stirred by the paddle wheel 304. The developer scraped off from the developing roller 305 by the doctor blade 307 is guided by the separator 308 and dropped onto the stirring roller 303 by the conveying screw 309.
[0009]
In the vicinity of the stirring roller 303 in the developing unit 301, a toner concentration sensor 310 is disposed as a means for detecting the mixing ratio of the developer toner and the carrier, that is, the toner concentration. The toner concentration sensor 310 detects the toner concentration of the developer in the developing unit 301. The developer in the developing unit 301 is supplied with toner from the toner supply unit 302. The toner replenishing unit 302 includes an agitator 312 as an agitating agent that stirs the toner inside, and a toner replenishing roller 311 that is rotationally driven to replenish toner to the developing unit 301 based on the detection result of the toner density sensor 310. A recovered toner supply opening 314 is formed at the upper part of the toner supply part 302, and a recovered toner supply connection part 315 is formed at the upper part. The recovered toner transferred by the recovered toner transfer device 500 described later passes through the recovered toner transfer pipe 400 and passes through the recovered toner transfer pipe 400, and is connected to the end of the recovered toner transfer pipe 400. 302 is replenished. Reference numeral 316 denotes an air vent hole, and 317 denotes an air filter. Since the collected toner is transferred together with the air, the air is vented here to prevent the pressure in the toner replenishing portion 302 and the developing portion 301 from rising.
A toner end sensor 313 serving as a means for detecting the toner end or toner near end of the toner replenishing unit 302 by detecting the remaining amount of toner in the toner replenishing unit 302 acts from the toner replenished from the toner replenishing unit 302 to the developing unit 301. By detecting the pressure to be detected, it comprises a piezoelectric element that detects the remaining amount of toner in the toner replenishing section, and outputs a detection signal when the pressure from the toner stops working. With this toner end detection signal or toner near end detection signal, new toner is supplied to the toner supply unit 302 by a toner supply unit that is separate from the developing device (not shown).
When the toner supply roller 311 is driven, the agitator 312 rotates through a gear (not shown), and the toner is conveyed from the front side to the back side and is sent onto the toner supply roller. The toner replenishing roller has a groove, and toner enters the groove and is replenished.
[0010]
FIG. 3 is a view of FIG. 2 viewed from the back side. In this case, the cleaning device 200, the photosensitive member 120, the developing device 300, the collected toner transfer device 500, and other image forming members are attached to the side plate beyond the side plate on the main body driving side of the copying machine main body 101. .
3 and 4 uses a powder pump 520 called a conventionally known commonly known Mono pump. As shown in FIG. 4, the powder pump 520 includes a male screw rotor 521 that is driven to rotate, and a female screw stator 522 that is made of an elastic body such as a rubber material fixed so as to surround the rotor 521. It is the screw pump comprised by this. The holder 523 holds the stator 522. For example, a single pitch or double pitch spiral groove is formed in the internally threaded stator.
The rotor 521 is engaged with one end of the lateral conveying screw 524 by a pin 525, and the other end of the lateral conveying screw 524 is connected to a seal member 526, a bearing 527, a main body drive system or a dedicated motor (independent of the main motor). The driven gear 528 is engaged with the driven gear 528 for driving.
The hopper 510 receives the recovered toner discharged from the recovered toner discharge member 220 of the cleaning device 200 through the cleaning recovery toner passage 511 and transfers the toner discharged from the recovered toner discharge member 720 of the transfer device 700. The collected toner passage 512 is engaged with the cleaning device 200 and the transfer device 700, and the collected toner discharged from the devices 200 and 700 is collectively guided to the bottom of the hopper and temporarily stored in a fixed amount. To do.
[0011]
Further, a gap of about 1 mm is provided between the outer side surface of the stator 522 and the inner side surface of the holder 523, and this gap communicates with the collected toner passage 530.
In addition, the holder 523 is provided with an air supply port 531 for blowing air into the collected toner passage 530 from the gap.
Further, an air pump (air supply means) 540 is disposed outside the holder 523, and an air discharge port 541 of the air pump 540 has a collected toner passage 530 via an air detector 550 and a pipe 542. The air supply port 531 communicates with the air supply port 531.
The air pump (air supply means) 540, by its operation, blows air into the collected toner through the air supply port 541 at a blowing rate of about 0.5 to 1 liter / minute. Accordingly, fluidization of the collected toner discharged from the powder pump 520 is promoted, and the collected toner is more reliably transferred by the powder pump 520.
The collected toner that has passed through the powder pump (screw pump) 520 is sent to the developing unit 300 or the collected toner storage unit 600 via the collected toner transfer pipe 400.
The collected toner transfer pipe 400 is, for example, a hollow tube having an inner diameter of about 4 to 6 mm and a thickness of about 1 to 2 mm. Since nothing needs to be provided in the pipe, a flexible material can be used. For example, it is very effective to use a flexible and excellent toner resistance material such as soft vinyl chloride, nylon, and Teflon.
[0012]
As described above, since the connecting portion 400 between the machine main body and the toner supply device is flexible, there are less restrictions when installing each device, the installation location can be effectively used, and the workability of machine maintenance is greatly improved. To do.
In this embodiment, the recovered toner transfer pipe 400 can be divided into a plurality of connections, and similarly, the pipe 542 of the air pump 540 can be divided into a plurality of connections. As a result, the apparatus can be easily unitized, and it is advantageous in terms of the productivity and maintainability of the apparatus.
Here, the transfer distance of the collected toner can be arbitrarily set by selecting the size of the rotor 521 and the stator 522 of the powder pump 520 to be used and the number of rotations of the rotor 521.
In addition, the transfer direction of the collected toner can be freely selected in any direction of up, down, left, and right. Therefore, the present invention has a markedly superior effect as compared with the conveying means that can be conveyed only by dropping it downward in the vertical direction as in the prior art.
[0013]
Next, FIG. 4 shows the configuration of the air detector 550 in this embodiment.
As described above, in collecting toner transfer using a powder pump, it is very important to transfer the collected toner together with air in order to ensure the reliability of the apparatus. The air detector 550 detects whether or not air is supplied from the air pump 540 to the powder pump, and has a role of a safety device for minimizing the system recovery of the toner recovery device.
The air detector 550 in the present embodiment is configured by enclosing a float 552 in a vertically movable manner in a transparent cylindrical container 553 having pipes 542 connected to both ends. When the air pump 540 described above is activated and air is sent into the container 553 in the direction of the arrow in FIG. 4, the air lifts the float 552 from the position (A) to the position (B). As a result, a sensor 551 (for example, a reflection type photosensor or a transmission type photosensor) for detecting the presence or absence of the float 552 arranged in advance so as to correspond to the position (B) described above The presence is detected, and it can be seen that air is normally supplied from the air pump 540 to the powder pump 520.
When the sensor 551 detects that the float 552 is not in the raised position in FIG. 4B even though the air pump 540 is operating, the air pump 540 to the powder pump 520 Since it is determined that some abnormality has occurred in the air supply, the operation of the copying machine main body 101 is stopped by a control device (not shown) and the occurrence of a failure is displayed on the display unit of the copying machine main body 101.
As the float 552 of this embodiment, a ball made of a resin or a metal such as stainless steel is used, but it goes without saying that other materials and shapes may be used.
Further, as the sensor 551 in this embodiment, a sensor based on reflected light detection is used, but a sensor such as transmitted light detection or magnetic detection can also be used.
[0014]
In the conventional apparatus, when it is desired to increase the transfer amount of the collected toner, the coil screw and the pipe are made large and rotate at a high speed, and when it is desired to increase the transfer distance or to change the transfer direction, a plurality of coil screws and pipes are connected. It was necessary to carry out multi-stage transfer to be connected by using them. However, this increases the number of parts, increases costs, decreases reliability, decreases apparatus maintenance and productivity, increases the apparatus body by increasing the installation volume of the collected toner transfer apparatus, and increases the apparatus installation area. Had brought.
On the other hand, the collected toner transfer device of this embodiment only needs to connect only the flexible collected toner transfer pipe to the developing device 300 or the collected toner storage means 600, and is an independent small separate unit. Therefore, it is possible to reduce the installation restrictions when installing the toner recovery device on the image forming apparatus main body, and to effectively use the installation location, and to perform productivity and maintenance work of the main body and the toner recovery device. The characteristics are greatly improved.
Further, in this recovered toner transfer device, the recovered toner is transferred in a state of mixture with the air in the recovered toner transfer pipe 400, so that there is almost no mechanical stress on the recovered toner, and the transfer pipe portion There is also no driving load. Therefore, according to this toner recovery device, the toner recovery and transfer can be ensured, and the transfer distance and transfer direction of the recovered toner are not restricted. In addition, according to the present embodiment, the reliability and durability of the toner recovery device can be sufficiently ensured, and further, the configuration of the toner recovery device can be simplified, and the power consumption can be reduced by reducing the driving load. Cost can be reduced.
[0015]
  Next, embodiments of the present inventionWill be described. In this embodiment, the screw pump is driven independently of the photosensitive member in the image forming apparatus using the screw pump means and the air supply means for fluidizing the collected toner moving by the screw pump means in a diffused state. , A stopable drive means or drive transmission means, a control unit for outputting a drive signal to the drive means, and a means for detecting the operation time of the photoconductor, according to the detection result of the photoconductor operation time detection means The feature is that the screw pump is driven, and the pump pump is driven for the minimum necessary time according to the image forming operation time, so that the efficiency of the pump drive is improved. .
  That is, as a method for driving the toner collecting apparatus of this embodiment, the toner is driven from a main drive source (a main motor, not shown) of the image forming apparatus main body 101 that drives the photosensitive drum and the like through a drive transmission mechanism such as a clutch. Alternatively, a method of driving by a dedicated motor (not shown) different from the main drive source is adopted. When the operation time of the photoconductor (image carrier) 120 reaches a certain amount, the main control plate of the copier body 101 sends a control signal to the drive clutch (or dedicated motor) of the toner recovery device and the air pump 540. In the control of the drive clutch (or dedicated motor) as the drive transmission means and the air pump 540, only the air pump 540 is turned on when the drive clutch (or dedicated motor) is turned on, and several seconds have passed. The drive clutch (or dedicated motor) is turned on later, and after the drive clutch (or dedicated motor) serving as drive transmission means is turned off, only the air pump 540 is operated for several seconds.
[0016]
The effect by performing the above control is shown below.
That is, the recovered toner mixed substantially uniformly with the air while the powder pump 520 is operating fills almost the entire area of the recovered toner transfer pipe 400. In this state, the entire apparatus is stopped at once. That is, when the powder pump 520 and the air pump 540 are stopped at the same time, only the air escapes from the collected toner mixed in the collected toner transfer pipe 400, and the collected toner sinks downward due to its own weight. The density of the collected toner in 400 increases.
For this reason, in this case, if the collected toner is sent by restarting the powder pump 520, the newly-collected collected toner is caused by the high-density collected toner remaining in the collected toner transfer pipe 400. In some cases, the collected toner is clogged inside the pipe 400 for transferring the collected toner due to the weir. As a result, the powder pump may be locked or burnt. This baking is a problem that the recovered toner adheres to the rotor 521 due to an excessive temperature rise, and the adhered toner scrapes the stator 522 to cause damage to the pump.
On the other hand, the high density collected toner remaining in the collected toner transfer pipe 400 is obtained by operating only the air pump 540 at the start of the operation of the powder pump 520 as in this embodiment. It can be discharged only by air. Alternatively, by operating only the air pump 540 after the operation of the powder pump 520 is stopped, the inside of the collected toner transfer pipe can be made almost empty. Therefore, according to the present embodiment, the clogging of the collected toner in the collected toner transfer pipe 400 as described above can be eliminated, and the collected toner can be transferred more reliably.
[0017]
Next, FIG. 5 shows a control system block diagram of the toner recovery apparatus of the present invention, and FIG. 6 shows a control flowchart of the toner recovery apparatus.
The toner recovery device is controlled by a control device having an MPU (micro processing unit). Here, the powder pump of the toner recovery device is driven from the main motor of the main body drive system via a clutch. The MPU has a timer function, and can control on / off of a clutch (drive transmission means), driving of an air pump, and the like at an arbitrary timing.
In the MPU of the control device, the cumulative driving time of the photoconductor, that is, the cumulative driving time of the main motor is measured by a timer and stored (S1 to S3). When the measured value reaches a preset value N (cumulative driving time), the timer is cleared, the clutch (M in FIG. 5) of the toner recovery device is turned on, and the air pump (P in FIG. 5) is driven. It is configured. In step 4, the toner transfer operation means from the start to the stop of the air pump and from the on to the off of the clutch of the powder pump.
Note that it is preferable to operate using a nonvolatile RAM so that the timer value is not cleared when the power is turned off.
[0018]
FIG. 7 shows detailed control timings of the powder pump and the air pump by the control device. First, when the main motor accumulated drive time reaches the set value N, the air pump is started to be driven. Further, control is performed so that the toner recovery device driving clutch is turned on with a delay of a predetermined time t1 from the start of driving of the air pump (for example, with a delay of 0.5 sec). The clutch is turned off after a predetermined time t2 (for example, after 2 seconds) elapses, and the toner recovery air pump is further delayed by a predetermined time t3 (for example, after 4 seconds) after the clutch is turned off. Is controlled to stop. By controlling in this way, as described above, the residual toner in the collection tube 400 can be discharged only by air, so that the collected toner clogging in the collection toner transfer pipe can be eliminated.
Further, an appropriate value can be obtained by calculation for the value of the cumulative driving time N as the set value. That is, the amount of toner collected on the photoconductor (main motor) is obtained from the toner adhesion amount per unit time during normal image formation, the transfer rate, and the like, and when the screw pump is driven once (see FIG. The ratio of the toner transfer amount (capacity) of the driving time per time (which varies depending on the set value of the driving time per time) is N to be obtained.
[0019]
  The following exampleAn exposure adjusting means (for example, included in the control device) that can adjust an applied voltage to be applied to an exposure lamp for forming an electrostatic latent image corresponding to an image on the photosensitive member, and adjusting the exposure adjusting means Since the screw pump drive start time is corrected according to the value, the accuracy of the toner recovery amount judgment is improved, the durability is improved by the high efficiency of the screw pump drive, and the toner recovery amount is temporarily It is possible to prevent the toner from overflowing in the screw pump unit due to the increase or to prevent crosslinking.
  In other words, the exposure adjustment means that can adjust the applied voltage to be applied to the exposure lamp is provided, and the interval of the toner transfer operation by the screw pump is adjusted according to the magnitude of the applied voltage. It is possible to improve the durability by improving the efficiency of the screw pump drive.
  Hereinafter, this embodiment will be described in detail with reference to FIG. In this embodiment, for example, an exposure adjusting means for adjusting the applied voltage to the exposure lamp is provided in the control device, and the applied voltage to the exposure lamp during driving of the main motor can be set in a plurality of stages by the exposure adjusting means. The applied voltage can be arbitrarily selected by the user. The control device performs a toner transfer operation (operations of the powder pump and the air pump) at preset intervals according to the applied voltage.
  For example, when the applied voltage is low, the toner adhesion amount on the photoconductor increases and the recovered toner amount also increases, so the interval between toner transfer operations is shortened, that is, the cumulative drive time N is a smaller value N1 (N1 <N1 < N) to increase the frequency of the toner transfer operation. Conversely, when the applied voltage is high, the amount of collected toner decreases, so the interval between toner transfer operations is lengthened.
  That is, the cumulative driving time N is set to a larger value N2 (N2> N) to reduce the frequency of the toner transfer operation. By the above operation, the driving efficiency of the powder pump can be further improved, and toner bridging or toner overflow in the hopper 510 due to an increase in collected toner can be prevented. Each of the values N1 and N2 can be obtained because the toner collection amount can be calculated from the image area and the transfer rate of the document if the toner adhesion amount corresponding to the exposure lamp applied voltage is known. Here, the image area of the document may be 6% to 30% of the image ratio of the transfer paper A4 that is generally used. The exposure adjusting means may be provided separately from the control device.
[0020]
[Claims1Example of form corresponding to
  Next, the claim1According to the present invention, when a paper jam occurs on the transfer paper in the conveyance path in the image forming apparatus, the drive timing of the screw pump and the air pump (air supply means) is corrected (that is, the drive of the screw pump and the air pump). When the transfer paper is jammed in the transport path, the screw pump and air pump areshort(It is driven at intervals) to improve the accuracy of toner recovery amount determination, simplify the configuration of the toner recovery device and reduce the cost, overflow the toner in the screw pump unit due to a temporary increase in the toner recovery amount, or Prevent cross-linkingRealizationit can.
  That is, in the conventional image forming apparatus, when a paper jam occurs on the transfer paper, it can be detected by a jam detection sensor. However, if a paper jam occurs before the transfer position, The developed toner may be cleaned and recovered without being placed on the transfer paper.
  In this case, since a large amount of collected toner is transported temporarily, there is a risk of toner overflow or cross-linking in the screw pump unit, so it is necessary to perform control to drive the screw pump and air pump. is there. At this time, for example, the amount of toner that can be conveyed can be increased by temporarily multiplying N, which is the value of the cumulative driving time, by a factor of 1/5 to shorten the screw pump driving cycle, for example. it can.
  Although FIG. 1 shows an example using a blade cleaning system as the cleaning apparatus 200, the toner recovery apparatus of the present invention is used even for a system using a magnetic brush cleaning system or a fur brush cleaning system. It goes without saying that it is possible.
  In addition to the toner collected from the photoreceptor, the toner recycling mechanism of the present invention transfers a toner image formed on the photoreceptor to an intermediate transfer body, and further retransfers it from this intermediate transfer body to transfer paper. The toner recovered from the intermediate transfer member (intermediate transfer belt or the like) on which image formation is performed can also be transported for recycling.
  That is, the toner transfer device of the present invention can be applied not only to the cleaning device for the photosensitive member but also to the cleaning device for the intermediate transfer member. Accordingly, in the claims, the image carrier is a concept including a photosensitive member and an intermediate transfer member. Furthermore, the present invention can also be applied to a cleaning device that removes toner adhering to a transfer paper transport body (transfer belt) that transports transfer paper. In these cases, it is effective to control the driving of the screw pump and the air pump using the accumulated driving time of the photosensitive member as a clue, but the cumulative driving time of the intermediate transfer member and the transfer paper transport member may be used as a clue.
[0021]
【The invention's effect】
  As described above, according to the present invention, there is provided a recovered toner transfer device that solves the conventional problems while satisfying the optimization of the size of the main body of the image forming apparatus and the quality, performance, and function as a cleaning device. Can do. That is, it prevents the wear of the stator over time and the decrease in pump discharge pressure due to the trouble when the toner mixed with the screw pump and the air pump is used to transfer the air-fuel mixture in the elastic tube. As a result, the durability of the toner transfer device can be ensured, the reliability can be improved, the configuration can be simplified, the toner can be reliably transferred, and the cost can be reduced.
  That is, the invention of claim 1When transfer paper is jammed, the drive timing of the screw pump and air pump is corrected, so the accuracy of toner recovery amount determination is improved, the configuration of the toner recovery device is simplified, and the cost is reduced. It is possible to prevent the toner in the screw pump unit from overflowing or cross-linking by temporarily increasing the amount of collected toner.
  Specifically, a toner transfer device in a case where a large amount of untransferred toner adheres to the photosensitive member due to paper jam in front of the transfer position, and this untransferred toner is removed and collected by a cleaning device. Therefore, toner clogging, toner overflow, cross-linking and the like can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic front cross-sectional view of an image forming apparatus using a first embodiment of the present invention.
FIG. 2 is a front sectional view of a peripheral portion of a photoconductor of an image forming apparatus using a first embodiment of the present invention.
FIG. 3 is a rear cross-sectional view of the periphery of a photoconductor of the image forming apparatus using the first embodiment of the present invention.
FIG. 4 is a configuration diagram of a collected toner transfer device using a first embodiment of the present invention.
FIG. 5 is a control system block diagram of a collected toner transfer device according to the present invention.
FIG. 6 is a control system flowchart of the collected toner transfer device according to the present invention.
7 is a timing chart showing operation timings of a drive motor and an air pump according to the present invention. FIG.
[Explanation of symbols]
100 copier, 101 copier body, 200 cleaning device, 220 recovered toner discharge member, 230 photosensitive member, 240 cleaning blade, 241 brush, 242 casing, 300 developing device, 400 recovered toner transfer pipe, 500 recovered toner transfer device , 510 hopper, 511 cleaning recovery toner path, 512 transfer recovery toner path, 520 powder pump, 521 rotor, 522 stator, 523 holder, 524 lateral conveying screw, 526 seal member, 527 bearing, 528 drive gear, 531 air supply port 540 air pump, 541 air outlet, 542 pipe, 550 air detector, 561 sensor, 552 float, 553 container, 600 recovered toner storage means.

Claims (1)

Image bearing member cleaning device, or a transfer sheet conveyance member of the cleaning device by the recovered toner recovered toner storage means or a means for transferring to the developing device, a female screw shaped stator provided with a helical groove therein, and a screw pump having a rotatably fitted interpolated male screw-shaped row data in said stator, to fluidize in a state of being diffused recovery toner to move is transferred collected toner-conveying pipe by the screw pump An image forming apparatus comprising: an air supply unit for driving; a driving unit or a driving transmission unit capable of driving and stopping the screw pump independently of an image carrier; and a control unit that outputs a driving signal to the driving unit. In
The control device corrects the drive timing of the screw pump and the air supply means when the paper jam of the transfer paper conveyed through the image forming apparatus occurs, and the screw pump and the air supply An image forming apparatus characterized in that the interval of the toner transfer operation by the means is shortened .

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